extent-tree.c 196.6 KB
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C
Chris Mason 已提交
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/*
 * Copyright (C) 2007 Oracle.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License v2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */
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#include <linux/sched.h>
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#include <linux/pagemap.h>
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#include <linux/writeback.h>
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#include <linux/blkdev.h>
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#include <linux/sort.h>
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#include <linux/rcupdate.h>
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#include <linux/kthread.h>
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#include <linux/slab.h>
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#include "compat.h"
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#include "hash.h"
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#include "ctree.h"
#include "disk-io.h"
#include "print-tree.h"
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#include "transaction.h"
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#include "volumes.h"
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#include "locking.h"
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#include "free-space-cache.h"
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/* control flags for do_chunk_alloc's force field
 * CHUNK_ALLOC_NO_FORCE means to only allocate a chunk
 * if we really need one.
 *
 * CHUNK_ALLOC_FORCE means it must try to allocate one
 *
 * CHUNK_ALLOC_LIMITED means to only try and allocate one
 * if we have very few chunks already allocated.  This is
 * used as part of the clustering code to help make sure
 * we have a good pool of storage to cluster in, without
 * filling the FS with empty chunks
 *
 */
enum {
	CHUNK_ALLOC_NO_FORCE = 0,
	CHUNK_ALLOC_FORCE = 1,
	CHUNK_ALLOC_LIMITED = 2,
};

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/*
 * Control how reservations are dealt with.
 *
 * RESERVE_FREE - freeing a reservation.
 * RESERVE_ALLOC - allocating space and we need to update bytes_may_use for
 *   ENOSPC accounting
 * RESERVE_ALLOC_NO_ACCOUNT - allocating space and we should not update
 *   bytes_may_use as the ENOSPC accounting is done elsewhere
 */
enum {
	RESERVE_FREE = 0,
	RESERVE_ALLOC = 1,
	RESERVE_ALLOC_NO_ACCOUNT = 2,
};

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static int update_block_group(struct btrfs_trans_handle *trans,
			      struct btrfs_root *root,
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			      u64 bytenr, u64 num_bytes, int alloc);
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static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
				struct btrfs_root *root,
				u64 bytenr, u64 num_bytes, u64 parent,
				u64 root_objectid, u64 owner_objectid,
				u64 owner_offset, int refs_to_drop,
				struct btrfs_delayed_extent_op *extra_op);
static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
				    struct extent_buffer *leaf,
				    struct btrfs_extent_item *ei);
static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
				      struct btrfs_root *root,
				      u64 parent, u64 root_objectid,
				      u64 flags, u64 owner, u64 offset,
				      struct btrfs_key *ins, int ref_mod);
static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
				     struct btrfs_root *root,
				     u64 parent, u64 root_objectid,
				     u64 flags, struct btrfs_disk_key *key,
				     int level, struct btrfs_key *ins);
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static int do_chunk_alloc(struct btrfs_trans_handle *trans,
			  struct btrfs_root *extent_root, u64 alloc_bytes,
			  u64 flags, int force);
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static int find_next_key(struct btrfs_path *path, int level,
			 struct btrfs_key *key);
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static void dump_space_info(struct btrfs_space_info *info, u64 bytes,
			    int dump_block_groups);
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static int btrfs_update_reserved_bytes(struct btrfs_block_group_cache *cache,
				       u64 num_bytes, int reserve);
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static noinline int
block_group_cache_done(struct btrfs_block_group_cache *cache)
{
	smp_mb();
	return cache->cached == BTRFS_CACHE_FINISHED;
}

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static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
{
	return (cache->flags & bits) == bits;
}

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static void btrfs_get_block_group(struct btrfs_block_group_cache *cache)
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{
	atomic_inc(&cache->count);
}

void btrfs_put_block_group(struct btrfs_block_group_cache *cache)
{
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	if (atomic_dec_and_test(&cache->count)) {
		WARN_ON(cache->pinned > 0);
		WARN_ON(cache->reserved > 0);
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		kfree(cache->free_space_ctl);
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		kfree(cache);
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	}
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}

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/*
 * this adds the block group to the fs_info rb tree for the block group
 * cache
 */
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static int btrfs_add_block_group_cache(struct btrfs_fs_info *info,
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				struct btrfs_block_group_cache *block_group)
{
	struct rb_node **p;
	struct rb_node *parent = NULL;
	struct btrfs_block_group_cache *cache;

	spin_lock(&info->block_group_cache_lock);
	p = &info->block_group_cache_tree.rb_node;

	while (*p) {
		parent = *p;
		cache = rb_entry(parent, struct btrfs_block_group_cache,
				 cache_node);
		if (block_group->key.objectid < cache->key.objectid) {
			p = &(*p)->rb_left;
		} else if (block_group->key.objectid > cache->key.objectid) {
			p = &(*p)->rb_right;
		} else {
			spin_unlock(&info->block_group_cache_lock);
			return -EEXIST;
		}
	}

	rb_link_node(&block_group->cache_node, parent, p);
	rb_insert_color(&block_group->cache_node,
			&info->block_group_cache_tree);
	spin_unlock(&info->block_group_cache_lock);

	return 0;
}

/*
 * This will return the block group at or after bytenr if contains is 0, else
 * it will return the block group that contains the bytenr
 */
static struct btrfs_block_group_cache *
block_group_cache_tree_search(struct btrfs_fs_info *info, u64 bytenr,
			      int contains)
{
	struct btrfs_block_group_cache *cache, *ret = NULL;
	struct rb_node *n;
	u64 end, start;

	spin_lock(&info->block_group_cache_lock);
	n = info->block_group_cache_tree.rb_node;

	while (n) {
		cache = rb_entry(n, struct btrfs_block_group_cache,
				 cache_node);
		end = cache->key.objectid + cache->key.offset - 1;
		start = cache->key.objectid;

		if (bytenr < start) {
			if (!contains && (!ret || start < ret->key.objectid))
				ret = cache;
			n = n->rb_left;
		} else if (bytenr > start) {
			if (contains && bytenr <= end) {
				ret = cache;
				break;
			}
			n = n->rb_right;
		} else {
			ret = cache;
			break;
		}
	}
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	if (ret)
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		btrfs_get_block_group(ret);
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	spin_unlock(&info->block_group_cache_lock);

	return ret;
}

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static int add_excluded_extent(struct btrfs_root *root,
			       u64 start, u64 num_bytes)
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{
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	u64 end = start + num_bytes - 1;
	set_extent_bits(&root->fs_info->freed_extents[0],
			start, end, EXTENT_UPTODATE, GFP_NOFS);
	set_extent_bits(&root->fs_info->freed_extents[1],
			start, end, EXTENT_UPTODATE, GFP_NOFS);
	return 0;
}
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static void free_excluded_extents(struct btrfs_root *root,
				  struct btrfs_block_group_cache *cache)
{
	u64 start, end;
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	start = cache->key.objectid;
	end = start + cache->key.offset - 1;

	clear_extent_bits(&root->fs_info->freed_extents[0],
			  start, end, EXTENT_UPTODATE, GFP_NOFS);
	clear_extent_bits(&root->fs_info->freed_extents[1],
			  start, end, EXTENT_UPTODATE, GFP_NOFS);
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}

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static int exclude_super_stripes(struct btrfs_root *root,
				 struct btrfs_block_group_cache *cache)
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{
	u64 bytenr;
	u64 *logical;
	int stripe_len;
	int i, nr, ret;

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	if (cache->key.objectid < BTRFS_SUPER_INFO_OFFSET) {
		stripe_len = BTRFS_SUPER_INFO_OFFSET - cache->key.objectid;
		cache->bytes_super += stripe_len;
		ret = add_excluded_extent(root, cache->key.objectid,
					  stripe_len);
		BUG_ON(ret);
	}

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	for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
		bytenr = btrfs_sb_offset(i);
		ret = btrfs_rmap_block(&root->fs_info->mapping_tree,
				       cache->key.objectid, bytenr,
				       0, &logical, &nr, &stripe_len);
		BUG_ON(ret);
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		while (nr--) {
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			cache->bytes_super += stripe_len;
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			ret = add_excluded_extent(root, logical[nr],
						  stripe_len);
			BUG_ON(ret);
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		}
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		kfree(logical);
	}
	return 0;
}

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static struct btrfs_caching_control *
get_caching_control(struct btrfs_block_group_cache *cache)
{
	struct btrfs_caching_control *ctl;

	spin_lock(&cache->lock);
	if (cache->cached != BTRFS_CACHE_STARTED) {
		spin_unlock(&cache->lock);
		return NULL;
	}

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	/* We're loading it the fast way, so we don't have a caching_ctl. */
	if (!cache->caching_ctl) {
		spin_unlock(&cache->lock);
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		return NULL;
	}

	ctl = cache->caching_ctl;
	atomic_inc(&ctl->count);
	spin_unlock(&cache->lock);
	return ctl;
}

static void put_caching_control(struct btrfs_caching_control *ctl)
{
	if (atomic_dec_and_test(&ctl->count))
		kfree(ctl);
}

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/*
 * this is only called by cache_block_group, since we could have freed extents
 * we need to check the pinned_extents for any extents that can't be used yet
 * since their free space will be released as soon as the transaction commits.
 */
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static u64 add_new_free_space(struct btrfs_block_group_cache *block_group,
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			      struct btrfs_fs_info *info, u64 start, u64 end)
{
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	u64 extent_start, extent_end, size, total_added = 0;
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	int ret;

	while (start < end) {
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		ret = find_first_extent_bit(info->pinned_extents, start,
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					    &extent_start, &extent_end,
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					    EXTENT_DIRTY | EXTENT_UPTODATE);
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		if (ret)
			break;

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		if (extent_start <= start) {
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			start = extent_end + 1;
		} else if (extent_start > start && extent_start < end) {
			size = extent_start - start;
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			total_added += size;
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			ret = btrfs_add_free_space(block_group, start,
						   size);
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			BUG_ON(ret);
			start = extent_end + 1;
		} else {
			break;
		}
	}

	if (start < end) {
		size = end - start;
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		total_added += size;
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		ret = btrfs_add_free_space(block_group, start, size);
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		BUG_ON(ret);
	}

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	return total_added;
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}

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static noinline void caching_thread(struct btrfs_work *work)
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{
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	struct btrfs_block_group_cache *block_group;
	struct btrfs_fs_info *fs_info;
	struct btrfs_caching_control *caching_ctl;
	struct btrfs_root *extent_root;
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	struct btrfs_path *path;
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	struct extent_buffer *leaf;
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	struct btrfs_key key;
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	u64 total_found = 0;
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	u64 last = 0;
	u32 nritems;
	int ret = 0;
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	caching_ctl = container_of(work, struct btrfs_caching_control, work);
	block_group = caching_ctl->block_group;
	fs_info = block_group->fs_info;
	extent_root = fs_info->extent_root;

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	path = btrfs_alloc_path();
	if (!path)
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		goto out;
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	last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET);
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	/*
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	 * We don't want to deadlock with somebody trying to allocate a new
	 * extent for the extent root while also trying to search the extent
	 * root to add free space.  So we skip locking and search the commit
	 * root, since its read-only
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	 */
	path->skip_locking = 1;
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	path->search_commit_root = 1;
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	path->reada = 1;
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	key.objectid = last;
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	key.offset = 0;
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	key.type = BTRFS_EXTENT_ITEM_KEY;
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again:
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	mutex_lock(&caching_ctl->mutex);
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	/* need to make sure the commit_root doesn't disappear */
	down_read(&fs_info->extent_commit_sem);

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	ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
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	if (ret < 0)
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		goto err;
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	leaf = path->nodes[0];
	nritems = btrfs_header_nritems(leaf);

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	while (1) {
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		if (btrfs_fs_closing(fs_info) > 1) {
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			last = (u64)-1;
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			break;
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		}
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		if (path->slots[0] < nritems) {
			btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
		} else {
			ret = find_next_key(path, 0, &key);
			if (ret)
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				break;
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			if (need_resched() ||
			    btrfs_next_leaf(extent_root, path)) {
				caching_ctl->progress = last;
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				btrfs_release_path(path);
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				up_read(&fs_info->extent_commit_sem);
				mutex_unlock(&caching_ctl->mutex);
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				cond_resched();
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				goto again;
			}
			leaf = path->nodes[0];
			nritems = btrfs_header_nritems(leaf);
			continue;
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		}
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		if (key.objectid < block_group->key.objectid) {
			path->slots[0]++;
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			continue;
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		}
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		if (key.objectid >= block_group->key.objectid +
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		    block_group->key.offset)
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			break;
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		if (key.type == BTRFS_EXTENT_ITEM_KEY) {
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			total_found += add_new_free_space(block_group,
							  fs_info, last,
							  key.objectid);
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			last = key.objectid + key.offset;
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			if (total_found > (1024 * 1024 * 2)) {
				total_found = 0;
				wake_up(&caching_ctl->wait);
			}
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		}
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		path->slots[0]++;
	}
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	ret = 0;
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	total_found += add_new_free_space(block_group, fs_info, last,
					  block_group->key.objectid +
					  block_group->key.offset);
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	caching_ctl->progress = (u64)-1;
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	spin_lock(&block_group->lock);
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	block_group->caching_ctl = NULL;
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	block_group->cached = BTRFS_CACHE_FINISHED;
	spin_unlock(&block_group->lock);
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err:
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	btrfs_free_path(path);
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	up_read(&fs_info->extent_commit_sem);
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	free_excluded_extents(extent_root, block_group);

	mutex_unlock(&caching_ctl->mutex);
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out:
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	wake_up(&caching_ctl->wait);

	put_caching_control(caching_ctl);
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	btrfs_put_block_group(block_group);
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}

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static int cache_block_group(struct btrfs_block_group_cache *cache,
			     struct btrfs_trans_handle *trans,
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			     struct btrfs_root *root,
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			     int load_cache_only)
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{
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	struct btrfs_fs_info *fs_info = cache->fs_info;
	struct btrfs_caching_control *caching_ctl;
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	int ret = 0;

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	smp_mb();
	if (cache->cached != BTRFS_CACHE_NO)
		return 0;

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	/*
	 * We can't do the read from on-disk cache during a commit since we need
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	 * to have the normal tree locking.  Also if we are currently trying to
	 * allocate blocks for the tree root we can't do the fast caching since
	 * we likely hold important locks.
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	 */
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	if (trans && (!trans->transaction->in_commit) &&
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	    (root && root != root->fs_info->tree_root) &&
	    btrfs_test_opt(root, SPACE_CACHE)) {
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		spin_lock(&cache->lock);
		if (cache->cached != BTRFS_CACHE_NO) {
			spin_unlock(&cache->lock);
			return 0;
		}
		cache->cached = BTRFS_CACHE_STARTED;
		spin_unlock(&cache->lock);

		ret = load_free_space_cache(fs_info, cache);

		spin_lock(&cache->lock);
		if (ret == 1) {
			cache->cached = BTRFS_CACHE_FINISHED;
			cache->last_byte_to_unpin = (u64)-1;
		} else {
			cache->cached = BTRFS_CACHE_NO;
		}
		spin_unlock(&cache->lock);
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		if (ret == 1) {
			free_excluded_extents(fs_info->extent_root, cache);
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			return 0;
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		}
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	}

	if (load_cache_only)
		return 0;

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	caching_ctl = kzalloc(sizeof(*caching_ctl), GFP_NOFS);
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	BUG_ON(!caching_ctl);

	INIT_LIST_HEAD(&caching_ctl->list);
	mutex_init(&caching_ctl->mutex);
	init_waitqueue_head(&caching_ctl->wait);
	caching_ctl->block_group = cache;
	caching_ctl->progress = cache->key.objectid;
	/* one for caching kthread, one for caching block group list */
	atomic_set(&caching_ctl->count, 2);
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	caching_ctl->work.func = caching_thread;
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	spin_lock(&cache->lock);
	if (cache->cached != BTRFS_CACHE_NO) {
		spin_unlock(&cache->lock);
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		kfree(caching_ctl);
		return 0;
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	}
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	cache->caching_ctl = caching_ctl;
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	cache->cached = BTRFS_CACHE_STARTED;
	spin_unlock(&cache->lock);

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	down_write(&fs_info->extent_commit_sem);
	list_add_tail(&caching_ctl->list, &fs_info->caching_block_groups);
	up_write(&fs_info->extent_commit_sem);

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	btrfs_get_block_group(cache);
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	btrfs_queue_worker(&fs_info->caching_workers, &caching_ctl->work);
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	return ret;
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}

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/*
 * return the block group that starts at or after bytenr
 */
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static struct btrfs_block_group_cache *
btrfs_lookup_first_block_group(struct btrfs_fs_info *info, u64 bytenr)
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{
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	struct btrfs_block_group_cache *cache;
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	cache = block_group_cache_tree_search(info, bytenr, 0);
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	return cache;
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}

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/*
560
 * return the block group that contains the given bytenr
J
Josef Bacik 已提交
561
 */
C
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562 563 564
struct btrfs_block_group_cache *btrfs_lookup_block_group(
						 struct btrfs_fs_info *info,
						 u64 bytenr)
C
Chris Mason 已提交
565
{
J
Josef Bacik 已提交
566
	struct btrfs_block_group_cache *cache;
C
Chris Mason 已提交
567

J
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568
	cache = block_group_cache_tree_search(info, bytenr, 1);
569

J
Josef Bacik 已提交
570
	return cache;
C
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571
}
572

J
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573 574
static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
						  u64 flags)
575
{
J
Josef Bacik 已提交
576 577
	struct list_head *head = &info->space_info;
	struct btrfs_space_info *found;
578

579 580 581
	flags &= BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_SYSTEM |
		 BTRFS_BLOCK_GROUP_METADATA;

582 583
	rcu_read_lock();
	list_for_each_entry_rcu(found, head, list) {
584
		if (found->flags & flags) {
585
			rcu_read_unlock();
J
Josef Bacik 已提交
586
			return found;
587
		}
J
Josef Bacik 已提交
588
	}
589
	rcu_read_unlock();
J
Josef Bacik 已提交
590
	return NULL;
591 592
}

593 594 595 596 597 598 599 600 601 602 603 604 605 606 607
/*
 * after adding space to the filesystem, we need to clear the full flags
 * on all the space infos.
 */
void btrfs_clear_space_info_full(struct btrfs_fs_info *info)
{
	struct list_head *head = &info->space_info;
	struct btrfs_space_info *found;

	rcu_read_lock();
	list_for_each_entry_rcu(found, head, list)
		found->full = 0;
	rcu_read_unlock();
}

608 609 610 611 612 613 614 615 616
static u64 div_factor(u64 num, int factor)
{
	if (factor == 10)
		return num;
	num *= factor;
	do_div(num, 10);
	return num;
}

617 618 619 620 621 622 623 624 625
static u64 div_factor_fine(u64 num, int factor)
{
	if (factor == 100)
		return num;
	num *= factor;
	do_div(num, 100);
	return num;
}

626 627
u64 btrfs_find_block_group(struct btrfs_root *root,
			   u64 search_start, u64 search_hint, int owner)
C
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628
{
629
	struct btrfs_block_group_cache *cache;
C
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630
	u64 used;
631 632
	u64 last = max(search_hint, search_start);
	u64 group_start = 0;
633
	int full_search = 0;
634
	int factor = 9;
C
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635
	int wrapped = 0;
636
again:
637 638
	while (1) {
		cache = btrfs_lookup_first_block_group(root->fs_info, last);
J
Josef Bacik 已提交
639 640
		if (!cache)
			break;
641

642
		spin_lock(&cache->lock);
643 644 645
		last = cache->key.objectid + cache->key.offset;
		used = btrfs_block_group_used(&cache->item);

646 647
		if ((full_search || !cache->ro) &&
		    block_group_bits(cache, BTRFS_BLOCK_GROUP_METADATA)) {
648
			if (used + cache->pinned + cache->reserved <
649 650
			    div_factor(cache->key.offset, factor)) {
				group_start = cache->key.objectid;
651
				spin_unlock(&cache->lock);
652
				btrfs_put_block_group(cache);
653 654
				goto found;
			}
655
		}
656
		spin_unlock(&cache->lock);
657
		btrfs_put_block_group(cache);
658
		cond_resched();
C
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659
	}
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660 661 662 663 664 665
	if (!wrapped) {
		last = search_start;
		wrapped = 1;
		goto again;
	}
	if (!full_search && factor < 10) {
C
Chris Mason 已提交
666
		last = search_start;
667
		full_search = 1;
C
Chris Mason 已提交
668
		factor = 10;
669 670
		goto again;
	}
C
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671
found:
672
	return group_start;
673
}
J
Josef Bacik 已提交
674

675
/* simple helper to search for an existing extent at a given offset */
Z
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676
int btrfs_lookup_extent(struct btrfs_root *root, u64 start, u64 len)
677 678 679
{
	int ret;
	struct btrfs_key key;
Z
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680
	struct btrfs_path *path;
681

Z
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682
	path = btrfs_alloc_path();
683 684 685
	if (!path)
		return -ENOMEM;

686 687 688 689 690
	key.objectid = start;
	key.offset = len;
	btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
	ret = btrfs_search_slot(NULL, root->fs_info->extent_root, &key, path,
				0, 0);
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691
	btrfs_free_path(path);
692 693 694
	return ret;
}

695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774
/*
 * helper function to lookup reference count and flags of extent.
 *
 * the head node for delayed ref is used to store the sum of all the
 * reference count modifications queued up in the rbtree. the head
 * node may also store the extent flags to set. This way you can check
 * to see what the reference count and extent flags would be if all of
 * the delayed refs are not processed.
 */
int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
			     struct btrfs_root *root, u64 bytenr,
			     u64 num_bytes, u64 *refs, u64 *flags)
{
	struct btrfs_delayed_ref_head *head;
	struct btrfs_delayed_ref_root *delayed_refs;
	struct btrfs_path *path;
	struct btrfs_extent_item *ei;
	struct extent_buffer *leaf;
	struct btrfs_key key;
	u32 item_size;
	u64 num_refs;
	u64 extent_flags;
	int ret;

	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;

	key.objectid = bytenr;
	key.type = BTRFS_EXTENT_ITEM_KEY;
	key.offset = num_bytes;
	if (!trans) {
		path->skip_locking = 1;
		path->search_commit_root = 1;
	}
again:
	ret = btrfs_search_slot(trans, root->fs_info->extent_root,
				&key, path, 0, 0);
	if (ret < 0)
		goto out_free;

	if (ret == 0) {
		leaf = path->nodes[0];
		item_size = btrfs_item_size_nr(leaf, path->slots[0]);
		if (item_size >= sizeof(*ei)) {
			ei = btrfs_item_ptr(leaf, path->slots[0],
					    struct btrfs_extent_item);
			num_refs = btrfs_extent_refs(leaf, ei);
			extent_flags = btrfs_extent_flags(leaf, ei);
		} else {
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
			struct btrfs_extent_item_v0 *ei0;
			BUG_ON(item_size != sizeof(*ei0));
			ei0 = btrfs_item_ptr(leaf, path->slots[0],
					     struct btrfs_extent_item_v0);
			num_refs = btrfs_extent_refs_v0(leaf, ei0);
			/* FIXME: this isn't correct for data */
			extent_flags = BTRFS_BLOCK_FLAG_FULL_BACKREF;
#else
			BUG();
#endif
		}
		BUG_ON(num_refs == 0);
	} else {
		num_refs = 0;
		extent_flags = 0;
		ret = 0;
	}

	if (!trans)
		goto out;

	delayed_refs = &trans->transaction->delayed_refs;
	spin_lock(&delayed_refs->lock);
	head = btrfs_find_delayed_ref_head(trans, bytenr);
	if (head) {
		if (!mutex_trylock(&head->mutex)) {
			atomic_inc(&head->node.refs);
			spin_unlock(&delayed_refs->lock);

775
			btrfs_release_path(path);
776

777 778 779 780
			/*
			 * Mutex was contended, block until it's released and try
			 * again
			 */
781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805
			mutex_lock(&head->mutex);
			mutex_unlock(&head->mutex);
			btrfs_put_delayed_ref(&head->node);
			goto again;
		}
		if (head->extent_op && head->extent_op->update_flags)
			extent_flags |= head->extent_op->flags_to_set;
		else
			BUG_ON(num_refs == 0);

		num_refs += head->node.ref_mod;
		mutex_unlock(&head->mutex);
	}
	spin_unlock(&delayed_refs->lock);
out:
	WARN_ON(num_refs == 0);
	if (refs)
		*refs = num_refs;
	if (flags)
		*flags = extent_flags;
out_free:
	btrfs_free_path(path);
	return ret;
}

806 807 808 809 810 811 812 813 814 815 816 817 818 819
/*
 * Back reference rules.  Back refs have three main goals:
 *
 * 1) differentiate between all holders of references to an extent so that
 *    when a reference is dropped we can make sure it was a valid reference
 *    before freeing the extent.
 *
 * 2) Provide enough information to quickly find the holders of an extent
 *    if we notice a given block is corrupted or bad.
 *
 * 3) Make it easy to migrate blocks for FS shrinking or storage pool
 *    maintenance.  This is actually the same as #2, but with a slightly
 *    different use case.
 *
820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864
 * There are two kinds of back refs. The implicit back refs is optimized
 * for pointers in non-shared tree blocks. For a given pointer in a block,
 * back refs of this kind provide information about the block's owner tree
 * and the pointer's key. These information allow us to find the block by
 * b-tree searching. The full back refs is for pointers in tree blocks not
 * referenced by their owner trees. The location of tree block is recorded
 * in the back refs. Actually the full back refs is generic, and can be
 * used in all cases the implicit back refs is used. The major shortcoming
 * of the full back refs is its overhead. Every time a tree block gets
 * COWed, we have to update back refs entry for all pointers in it.
 *
 * For a newly allocated tree block, we use implicit back refs for
 * pointers in it. This means most tree related operations only involve
 * implicit back refs. For a tree block created in old transaction, the
 * only way to drop a reference to it is COW it. So we can detect the
 * event that tree block loses its owner tree's reference and do the
 * back refs conversion.
 *
 * When a tree block is COW'd through a tree, there are four cases:
 *
 * The reference count of the block is one and the tree is the block's
 * owner tree. Nothing to do in this case.
 *
 * The reference count of the block is one and the tree is not the
 * block's owner tree. In this case, full back refs is used for pointers
 * in the block. Remove these full back refs, add implicit back refs for
 * every pointers in the new block.
 *
 * The reference count of the block is greater than one and the tree is
 * the block's owner tree. In this case, implicit back refs is used for
 * pointers in the block. Add full back refs for every pointers in the
 * block, increase lower level extents' reference counts. The original
 * implicit back refs are entailed to the new block.
 *
 * The reference count of the block is greater than one and the tree is
 * not the block's owner tree. Add implicit back refs for every pointer in
 * the new block, increase lower level extents' reference count.
 *
 * Back Reference Key composing:
 *
 * The key objectid corresponds to the first byte in the extent,
 * The key type is used to differentiate between types of back refs.
 * There are different meanings of the key offset for different types
 * of back refs.
 *
865 866 867
 * File extents can be referenced by:
 *
 * - multiple snapshots, subvolumes, or different generations in one subvol
Z
Zheng Yan 已提交
868
 * - different files inside a single subvolume
869 870
 * - different offsets inside a file (bookend extents in file.c)
 *
871
 * The extent ref structure for the implicit back refs has fields for:
872 873 874
 *
 * - Objectid of the subvolume root
 * - objectid of the file holding the reference
875 876
 * - original offset in the file
 * - how many bookend extents
877
 *
878 879
 * The key offset for the implicit back refs is hash of the first
 * three fields.
880
 *
881
 * The extent ref structure for the full back refs has field for:
882
 *
883
 * - number of pointers in the tree leaf
884
 *
885 886
 * The key offset for the implicit back refs is the first byte of
 * the tree leaf
887
 *
888 889
 * When a file extent is allocated, The implicit back refs is used.
 * the fields are filled in:
890
 *
891
 *     (root_key.objectid, inode objectid, offset in file, 1)
892
 *
893 894
 * When a file extent is removed file truncation, we find the
 * corresponding implicit back refs and check the following fields:
895
 *
896
 *     (btrfs_header_owner(leaf), inode objectid, offset in file)
897
 *
898
 * Btree extents can be referenced by:
899
 *
900
 * - Different subvolumes
901
 *
902 903 904 905
 * Both the implicit back refs and the full back refs for tree blocks
 * only consist of key. The key offset for the implicit back refs is
 * objectid of block's owner tree. The key offset for the full back refs
 * is the first byte of parent block.
906
 *
907 908 909
 * When implicit back refs is used, information about the lowest key and
 * level of the tree block are required. These information are stored in
 * tree block info structure.
910
 */
Z
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911

912 913 914 915 916
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
static int convert_extent_item_v0(struct btrfs_trans_handle *trans,
				  struct btrfs_root *root,
				  struct btrfs_path *path,
				  u64 owner, u32 extra_size)
917
{
918 919 920 921 922
	struct btrfs_extent_item *item;
	struct btrfs_extent_item_v0 *ei0;
	struct btrfs_extent_ref_v0 *ref0;
	struct btrfs_tree_block_info *bi;
	struct extent_buffer *leaf;
923
	struct btrfs_key key;
924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958
	struct btrfs_key found_key;
	u32 new_size = sizeof(*item);
	u64 refs;
	int ret;

	leaf = path->nodes[0];
	BUG_ON(btrfs_item_size_nr(leaf, path->slots[0]) != sizeof(*ei0));

	btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
	ei0 = btrfs_item_ptr(leaf, path->slots[0],
			     struct btrfs_extent_item_v0);
	refs = btrfs_extent_refs_v0(leaf, ei0);

	if (owner == (u64)-1) {
		while (1) {
			if (path->slots[0] >= btrfs_header_nritems(leaf)) {
				ret = btrfs_next_leaf(root, path);
				if (ret < 0)
					return ret;
				BUG_ON(ret > 0);
				leaf = path->nodes[0];
			}
			btrfs_item_key_to_cpu(leaf, &found_key,
					      path->slots[0]);
			BUG_ON(key.objectid != found_key.objectid);
			if (found_key.type != BTRFS_EXTENT_REF_V0_KEY) {
				path->slots[0]++;
				continue;
			}
			ref0 = btrfs_item_ptr(leaf, path->slots[0],
					      struct btrfs_extent_ref_v0);
			owner = btrfs_ref_objectid_v0(leaf, ref0);
			break;
		}
	}
959
	btrfs_release_path(path);
960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000

	if (owner < BTRFS_FIRST_FREE_OBJECTID)
		new_size += sizeof(*bi);

	new_size -= sizeof(*ei0);
	ret = btrfs_search_slot(trans, root, &key, path,
				new_size + extra_size, 1);
	if (ret < 0)
		return ret;
	BUG_ON(ret);

	ret = btrfs_extend_item(trans, root, path, new_size);

	leaf = path->nodes[0];
	item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
	btrfs_set_extent_refs(leaf, item, refs);
	/* FIXME: get real generation */
	btrfs_set_extent_generation(leaf, item, 0);
	if (owner < BTRFS_FIRST_FREE_OBJECTID) {
		btrfs_set_extent_flags(leaf, item,
				       BTRFS_EXTENT_FLAG_TREE_BLOCK |
				       BTRFS_BLOCK_FLAG_FULL_BACKREF);
		bi = (struct btrfs_tree_block_info *)(item + 1);
		/* FIXME: get first key of the block */
		memset_extent_buffer(leaf, 0, (unsigned long)bi, sizeof(*bi));
		btrfs_set_tree_block_level(leaf, bi, (int)owner);
	} else {
		btrfs_set_extent_flags(leaf, item, BTRFS_EXTENT_FLAG_DATA);
	}
	btrfs_mark_buffer_dirty(leaf);
	return 0;
}
#endif

static u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset)
{
	u32 high_crc = ~(u32)0;
	u32 low_crc = ~(u32)0;
	__le64 lenum;

	lenum = cpu_to_le64(root_objectid);
1001
	high_crc = crc32c(high_crc, &lenum, sizeof(lenum));
1002
	lenum = cpu_to_le64(owner);
1003
	low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
1004
	lenum = cpu_to_le64(offset);
1005
	low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037

	return ((u64)high_crc << 31) ^ (u64)low_crc;
}

static u64 hash_extent_data_ref_item(struct extent_buffer *leaf,
				     struct btrfs_extent_data_ref *ref)
{
	return hash_extent_data_ref(btrfs_extent_data_ref_root(leaf, ref),
				    btrfs_extent_data_ref_objectid(leaf, ref),
				    btrfs_extent_data_ref_offset(leaf, ref));
}

static int match_extent_data_ref(struct extent_buffer *leaf,
				 struct btrfs_extent_data_ref *ref,
				 u64 root_objectid, u64 owner, u64 offset)
{
	if (btrfs_extent_data_ref_root(leaf, ref) != root_objectid ||
	    btrfs_extent_data_ref_objectid(leaf, ref) != owner ||
	    btrfs_extent_data_ref_offset(leaf, ref) != offset)
		return 0;
	return 1;
}

static noinline int lookup_extent_data_ref(struct btrfs_trans_handle *trans,
					   struct btrfs_root *root,
					   struct btrfs_path *path,
					   u64 bytenr, u64 parent,
					   u64 root_objectid,
					   u64 owner, u64 offset)
{
	struct btrfs_key key;
	struct btrfs_extent_data_ref *ref;
Z
Zheng Yan 已提交
1038
	struct extent_buffer *leaf;
1039
	u32 nritems;
1040
	int ret;
1041 1042
	int recow;
	int err = -ENOENT;
1043

Z
Zheng Yan 已提交
1044
	key.objectid = bytenr;
1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059
	if (parent) {
		key.type = BTRFS_SHARED_DATA_REF_KEY;
		key.offset = parent;
	} else {
		key.type = BTRFS_EXTENT_DATA_REF_KEY;
		key.offset = hash_extent_data_ref(root_objectid,
						  owner, offset);
	}
again:
	recow = 0;
	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
	if (ret < 0) {
		err = ret;
		goto fail;
	}
Z
Zheng Yan 已提交
1060

1061 1062 1063 1064 1065
	if (parent) {
		if (!ret)
			return 0;
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
		key.type = BTRFS_EXTENT_REF_V0_KEY;
1066
		btrfs_release_path(path);
1067 1068 1069 1070 1071 1072 1073 1074 1075
		ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
		if (ret < 0) {
			err = ret;
			goto fail;
		}
		if (!ret)
			return 0;
#endif
		goto fail;
Z
Zheng Yan 已提交
1076 1077 1078
	}

	leaf = path->nodes[0];
1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103
	nritems = btrfs_header_nritems(leaf);
	while (1) {
		if (path->slots[0] >= nritems) {
			ret = btrfs_next_leaf(root, path);
			if (ret < 0)
				err = ret;
			if (ret)
				goto fail;

			leaf = path->nodes[0];
			nritems = btrfs_header_nritems(leaf);
			recow = 1;
		}

		btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
		if (key.objectid != bytenr ||
		    key.type != BTRFS_EXTENT_DATA_REF_KEY)
			goto fail;

		ref = btrfs_item_ptr(leaf, path->slots[0],
				     struct btrfs_extent_data_ref);

		if (match_extent_data_ref(leaf, ref, root_objectid,
					  owner, offset)) {
			if (recow) {
1104
				btrfs_release_path(path);
1105 1106 1107 1108 1109 1110
				goto again;
			}
			err = 0;
			break;
		}
		path->slots[0]++;
Z
Zheng Yan 已提交
1111
	}
1112 1113
fail:
	return err;
Z
Zheng Yan 已提交
1114 1115
}

1116 1117 1118 1119 1120 1121
static noinline int insert_extent_data_ref(struct btrfs_trans_handle *trans,
					   struct btrfs_root *root,
					   struct btrfs_path *path,
					   u64 bytenr, u64 parent,
					   u64 root_objectid, u64 owner,
					   u64 offset, int refs_to_add)
Z
Zheng Yan 已提交
1122 1123 1124
{
	struct btrfs_key key;
	struct extent_buffer *leaf;
1125
	u32 size;
Z
Zheng Yan 已提交
1126 1127
	u32 num_refs;
	int ret;
1128 1129

	key.objectid = bytenr;
1130 1131 1132 1133 1134 1135 1136 1137 1138 1139
	if (parent) {
		key.type = BTRFS_SHARED_DATA_REF_KEY;
		key.offset = parent;
		size = sizeof(struct btrfs_shared_data_ref);
	} else {
		key.type = BTRFS_EXTENT_DATA_REF_KEY;
		key.offset = hash_extent_data_ref(root_objectid,
						  owner, offset);
		size = sizeof(struct btrfs_extent_data_ref);
	}
1140

1141 1142 1143 1144 1145 1146 1147
	ret = btrfs_insert_empty_item(trans, root, path, &key, size);
	if (ret && ret != -EEXIST)
		goto fail;

	leaf = path->nodes[0];
	if (parent) {
		struct btrfs_shared_data_ref *ref;
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		ref = btrfs_item_ptr(leaf, path->slots[0],
1149 1150 1151 1152 1153 1154 1155
				     struct btrfs_shared_data_ref);
		if (ret == 0) {
			btrfs_set_shared_data_ref_count(leaf, ref, refs_to_add);
		} else {
			num_refs = btrfs_shared_data_ref_count(leaf, ref);
			num_refs += refs_to_add;
			btrfs_set_shared_data_ref_count(leaf, ref, num_refs);
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		}
1157 1158 1159 1160 1161 1162 1163 1164
	} else {
		struct btrfs_extent_data_ref *ref;
		while (ret == -EEXIST) {
			ref = btrfs_item_ptr(leaf, path->slots[0],
					     struct btrfs_extent_data_ref);
			if (match_extent_data_ref(leaf, ref, root_objectid,
						  owner, offset))
				break;
1165
			btrfs_release_path(path);
1166 1167 1168 1169 1170
			key.offset++;
			ret = btrfs_insert_empty_item(trans, root, path, &key,
						      size);
			if (ret && ret != -EEXIST)
				goto fail;
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1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185
			leaf = path->nodes[0];
		}
		ref = btrfs_item_ptr(leaf, path->slots[0],
				     struct btrfs_extent_data_ref);
		if (ret == 0) {
			btrfs_set_extent_data_ref_root(leaf, ref,
						       root_objectid);
			btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
			btrfs_set_extent_data_ref_offset(leaf, ref, offset);
			btrfs_set_extent_data_ref_count(leaf, ref, refs_to_add);
		} else {
			num_refs = btrfs_extent_data_ref_count(leaf, ref);
			num_refs += refs_to_add;
			btrfs_set_extent_data_ref_count(leaf, ref, num_refs);
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		}
	}
1188 1189 1190
	btrfs_mark_buffer_dirty(leaf);
	ret = 0;
fail:
1191
	btrfs_release_path(path);
1192
	return ret;
1193 1194
}

1195 1196 1197 1198
static noinline int remove_extent_data_ref(struct btrfs_trans_handle *trans,
					   struct btrfs_root *root,
					   struct btrfs_path *path,
					   int refs_to_drop)
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{
1200 1201 1202
	struct btrfs_key key;
	struct btrfs_extent_data_ref *ref1 = NULL;
	struct btrfs_shared_data_ref *ref2 = NULL;
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	struct extent_buffer *leaf;
1204
	u32 num_refs = 0;
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	int ret = 0;

	leaf = path->nodes[0];
1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228
	btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);

	if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
		ref1 = btrfs_item_ptr(leaf, path->slots[0],
				      struct btrfs_extent_data_ref);
		num_refs = btrfs_extent_data_ref_count(leaf, ref1);
	} else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
		ref2 = btrfs_item_ptr(leaf, path->slots[0],
				      struct btrfs_shared_data_ref);
		num_refs = btrfs_shared_data_ref_count(leaf, ref2);
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
	} else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
		struct btrfs_extent_ref_v0 *ref0;
		ref0 = btrfs_item_ptr(leaf, path->slots[0],
				      struct btrfs_extent_ref_v0);
		num_refs = btrfs_ref_count_v0(leaf, ref0);
#endif
	} else {
		BUG();
	}

1229 1230
	BUG_ON(num_refs < refs_to_drop);
	num_refs -= refs_to_drop;
1231

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	if (num_refs == 0) {
		ret = btrfs_del_item(trans, root, path);
	} else {
1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246
		if (key.type == BTRFS_EXTENT_DATA_REF_KEY)
			btrfs_set_extent_data_ref_count(leaf, ref1, num_refs);
		else if (key.type == BTRFS_SHARED_DATA_REF_KEY)
			btrfs_set_shared_data_ref_count(leaf, ref2, num_refs);
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
		else {
			struct btrfs_extent_ref_v0 *ref0;
			ref0 = btrfs_item_ptr(leaf, path->slots[0],
					struct btrfs_extent_ref_v0);
			btrfs_set_ref_count_v0(leaf, ref0, num_refs);
		}
#endif
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		btrfs_mark_buffer_dirty(leaf);
	}
	return ret;
}

1252 1253 1254
static noinline u32 extent_data_ref_count(struct btrfs_root *root,
					  struct btrfs_path *path,
					  struct btrfs_extent_inline_ref *iref)
1255
{
1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286
	struct btrfs_key key;
	struct extent_buffer *leaf;
	struct btrfs_extent_data_ref *ref1;
	struct btrfs_shared_data_ref *ref2;
	u32 num_refs = 0;

	leaf = path->nodes[0];
	btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
	if (iref) {
		if (btrfs_extent_inline_ref_type(leaf, iref) ==
		    BTRFS_EXTENT_DATA_REF_KEY) {
			ref1 = (struct btrfs_extent_data_ref *)(&iref->offset);
			num_refs = btrfs_extent_data_ref_count(leaf, ref1);
		} else {
			ref2 = (struct btrfs_shared_data_ref *)(iref + 1);
			num_refs = btrfs_shared_data_ref_count(leaf, ref2);
		}
	} else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
		ref1 = btrfs_item_ptr(leaf, path->slots[0],
				      struct btrfs_extent_data_ref);
		num_refs = btrfs_extent_data_ref_count(leaf, ref1);
	} else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
		ref2 = btrfs_item_ptr(leaf, path->slots[0],
				      struct btrfs_shared_data_ref);
		num_refs = btrfs_shared_data_ref_count(leaf, ref2);
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
	} else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
		struct btrfs_extent_ref_v0 *ref0;
		ref0 = btrfs_item_ptr(leaf, path->slots[0],
				      struct btrfs_extent_ref_v0);
		num_refs = btrfs_ref_count_v0(leaf, ref0);
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#endif
1288 1289 1290 1291 1292
	} else {
		WARN_ON(1);
	}
	return num_refs;
}
1293

1294 1295 1296 1297 1298
static noinline int lookup_tree_block_ref(struct btrfs_trans_handle *trans,
					  struct btrfs_root *root,
					  struct btrfs_path *path,
					  u64 bytenr, u64 parent,
					  u64 root_objectid)
1299
{
1300
	struct btrfs_key key;
1301 1302
	int ret;

1303 1304 1305 1306 1307 1308 1309
	key.objectid = bytenr;
	if (parent) {
		key.type = BTRFS_SHARED_BLOCK_REF_KEY;
		key.offset = parent;
	} else {
		key.type = BTRFS_TREE_BLOCK_REF_KEY;
		key.offset = root_objectid;
1310 1311
	}

1312 1313 1314 1315 1316
	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
	if (ret > 0)
		ret = -ENOENT;
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
	if (ret == -ENOENT && parent) {
1317
		btrfs_release_path(path);
1318 1319 1320 1321 1322
		key.type = BTRFS_EXTENT_REF_V0_KEY;
		ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
		if (ret > 0)
			ret = -ENOENT;
	}
1323
#endif
1324
	return ret;
1325 1326
}

1327 1328 1329 1330 1331
static noinline int insert_tree_block_ref(struct btrfs_trans_handle *trans,
					  struct btrfs_root *root,
					  struct btrfs_path *path,
					  u64 bytenr, u64 parent,
					  u64 root_objectid)
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1332
{
1333
	struct btrfs_key key;
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1334 1335
	int ret;

1336 1337 1338 1339 1340 1341 1342 1343 1344 1345
	key.objectid = bytenr;
	if (parent) {
		key.type = BTRFS_SHARED_BLOCK_REF_KEY;
		key.offset = parent;
	} else {
		key.type = BTRFS_TREE_BLOCK_REF_KEY;
		key.offset = root_objectid;
	}

	ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
1346
	btrfs_release_path(path);
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	return ret;
}

1350
static inline int extent_ref_type(u64 parent, u64 owner)
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1351
{
1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364
	int type;
	if (owner < BTRFS_FIRST_FREE_OBJECTID) {
		if (parent > 0)
			type = BTRFS_SHARED_BLOCK_REF_KEY;
		else
			type = BTRFS_TREE_BLOCK_REF_KEY;
	} else {
		if (parent > 0)
			type = BTRFS_SHARED_DATA_REF_KEY;
		else
			type = BTRFS_EXTENT_DATA_REF_KEY;
	}
	return type;
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1365
}
1366

1367 1368
static int find_next_key(struct btrfs_path *path, int level,
			 struct btrfs_key *key)
1369

C
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1370
{
1371
	for (; level < BTRFS_MAX_LEVEL; level++) {
1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386
		if (!path->nodes[level])
			break;
		if (path->slots[level] + 1 >=
		    btrfs_header_nritems(path->nodes[level]))
			continue;
		if (level == 0)
			btrfs_item_key_to_cpu(path->nodes[level], key,
					      path->slots[level] + 1);
		else
			btrfs_node_key_to_cpu(path->nodes[level], key,
					      path->slots[level] + 1);
		return 0;
	}
	return 1;
}
C
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1387

1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422
/*
 * look for inline back ref. if back ref is found, *ref_ret is set
 * to the address of inline back ref, and 0 is returned.
 *
 * if back ref isn't found, *ref_ret is set to the address where it
 * should be inserted, and -ENOENT is returned.
 *
 * if insert is true and there are too many inline back refs, the path
 * points to the extent item, and -EAGAIN is returned.
 *
 * NOTE: inline back refs are ordered in the same way that back ref
 *	 items in the tree are ordered.
 */
static noinline_for_stack
int lookup_inline_extent_backref(struct btrfs_trans_handle *trans,
				 struct btrfs_root *root,
				 struct btrfs_path *path,
				 struct btrfs_extent_inline_ref **ref_ret,
				 u64 bytenr, u64 num_bytes,
				 u64 parent, u64 root_objectid,
				 u64 owner, u64 offset, int insert)
{
	struct btrfs_key key;
	struct extent_buffer *leaf;
	struct btrfs_extent_item *ei;
	struct btrfs_extent_inline_ref *iref;
	u64 flags;
	u64 item_size;
	unsigned long ptr;
	unsigned long end;
	int extra_size;
	int type;
	int want;
	int ret;
	int err = 0;
1423

1424
	key.objectid = bytenr;
Z
Zheng Yan 已提交
1425
	key.type = BTRFS_EXTENT_ITEM_KEY;
1426
	key.offset = num_bytes;
Z
Zheng Yan 已提交
1427

1428 1429 1430
	want = extent_ref_type(parent, owner);
	if (insert) {
		extra_size = btrfs_extent_inline_ref_size(want);
1431
		path->keep_locks = 1;
1432 1433 1434
	} else
		extra_size = -1;
	ret = btrfs_search_slot(trans, root, &key, path, extra_size, 1);
1435
	if (ret < 0) {
1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532
		err = ret;
		goto out;
	}
	BUG_ON(ret);

	leaf = path->nodes[0];
	item_size = btrfs_item_size_nr(leaf, path->slots[0]);
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
	if (item_size < sizeof(*ei)) {
		if (!insert) {
			err = -ENOENT;
			goto out;
		}
		ret = convert_extent_item_v0(trans, root, path, owner,
					     extra_size);
		if (ret < 0) {
			err = ret;
			goto out;
		}
		leaf = path->nodes[0];
		item_size = btrfs_item_size_nr(leaf, path->slots[0]);
	}
#endif
	BUG_ON(item_size < sizeof(*ei));

	ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
	flags = btrfs_extent_flags(leaf, ei);

	ptr = (unsigned long)(ei + 1);
	end = (unsigned long)ei + item_size;

	if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
		ptr += sizeof(struct btrfs_tree_block_info);
		BUG_ON(ptr > end);
	} else {
		BUG_ON(!(flags & BTRFS_EXTENT_FLAG_DATA));
	}

	err = -ENOENT;
	while (1) {
		if (ptr >= end) {
			WARN_ON(ptr > end);
			break;
		}
		iref = (struct btrfs_extent_inline_ref *)ptr;
		type = btrfs_extent_inline_ref_type(leaf, iref);
		if (want < type)
			break;
		if (want > type) {
			ptr += btrfs_extent_inline_ref_size(type);
			continue;
		}

		if (type == BTRFS_EXTENT_DATA_REF_KEY) {
			struct btrfs_extent_data_ref *dref;
			dref = (struct btrfs_extent_data_ref *)(&iref->offset);
			if (match_extent_data_ref(leaf, dref, root_objectid,
						  owner, offset)) {
				err = 0;
				break;
			}
			if (hash_extent_data_ref_item(leaf, dref) <
			    hash_extent_data_ref(root_objectid, owner, offset))
				break;
		} else {
			u64 ref_offset;
			ref_offset = btrfs_extent_inline_ref_offset(leaf, iref);
			if (parent > 0) {
				if (parent == ref_offset) {
					err = 0;
					break;
				}
				if (ref_offset < parent)
					break;
			} else {
				if (root_objectid == ref_offset) {
					err = 0;
					break;
				}
				if (ref_offset < root_objectid)
					break;
			}
		}
		ptr += btrfs_extent_inline_ref_size(type);
	}
	if (err == -ENOENT && insert) {
		if (item_size + extra_size >=
		    BTRFS_MAX_EXTENT_ITEM_SIZE(root)) {
			err = -EAGAIN;
			goto out;
		}
		/*
		 * To add new inline back ref, we have to make sure
		 * there is no corresponding back ref item.
		 * For simplicity, we just do not add new inline back
		 * ref if there is any kind of item for this block
		 */
1533 1534
		if (find_next_key(path, 0, &key) == 0 &&
		    key.objectid == bytenr &&
1535
		    key.type < BTRFS_BLOCK_GROUP_ITEM_KEY) {
1536 1537 1538 1539 1540 1541
			err = -EAGAIN;
			goto out;
		}
	}
	*ref_ret = (struct btrfs_extent_inline_ref *)ptr;
out:
1542
	if (insert) {
1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628
		path->keep_locks = 0;
		btrfs_unlock_up_safe(path, 1);
	}
	return err;
}

/*
 * helper to add new inline back ref
 */
static noinline_for_stack
int setup_inline_extent_backref(struct btrfs_trans_handle *trans,
				struct btrfs_root *root,
				struct btrfs_path *path,
				struct btrfs_extent_inline_ref *iref,
				u64 parent, u64 root_objectid,
				u64 owner, u64 offset, int refs_to_add,
				struct btrfs_delayed_extent_op *extent_op)
{
	struct extent_buffer *leaf;
	struct btrfs_extent_item *ei;
	unsigned long ptr;
	unsigned long end;
	unsigned long item_offset;
	u64 refs;
	int size;
	int type;
	int ret;

	leaf = path->nodes[0];
	ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
	item_offset = (unsigned long)iref - (unsigned long)ei;

	type = extent_ref_type(parent, owner);
	size = btrfs_extent_inline_ref_size(type);

	ret = btrfs_extend_item(trans, root, path, size);

	ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
	refs = btrfs_extent_refs(leaf, ei);
	refs += refs_to_add;
	btrfs_set_extent_refs(leaf, ei, refs);
	if (extent_op)
		__run_delayed_extent_op(extent_op, leaf, ei);

	ptr = (unsigned long)ei + item_offset;
	end = (unsigned long)ei + btrfs_item_size_nr(leaf, path->slots[0]);
	if (ptr < end - size)
		memmove_extent_buffer(leaf, ptr + size, ptr,
				      end - size - ptr);

	iref = (struct btrfs_extent_inline_ref *)ptr;
	btrfs_set_extent_inline_ref_type(leaf, iref, type);
	if (type == BTRFS_EXTENT_DATA_REF_KEY) {
		struct btrfs_extent_data_ref *dref;
		dref = (struct btrfs_extent_data_ref *)(&iref->offset);
		btrfs_set_extent_data_ref_root(leaf, dref, root_objectid);
		btrfs_set_extent_data_ref_objectid(leaf, dref, owner);
		btrfs_set_extent_data_ref_offset(leaf, dref, offset);
		btrfs_set_extent_data_ref_count(leaf, dref, refs_to_add);
	} else if (type == BTRFS_SHARED_DATA_REF_KEY) {
		struct btrfs_shared_data_ref *sref;
		sref = (struct btrfs_shared_data_ref *)(iref + 1);
		btrfs_set_shared_data_ref_count(leaf, sref, refs_to_add);
		btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
	} else if (type == BTRFS_SHARED_BLOCK_REF_KEY) {
		btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
	} else {
		btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
	}
	btrfs_mark_buffer_dirty(leaf);
	return 0;
}

static int lookup_extent_backref(struct btrfs_trans_handle *trans,
				 struct btrfs_root *root,
				 struct btrfs_path *path,
				 struct btrfs_extent_inline_ref **ref_ret,
				 u64 bytenr, u64 num_bytes, u64 parent,
				 u64 root_objectid, u64 owner, u64 offset)
{
	int ret;

	ret = lookup_inline_extent_backref(trans, root, path, ref_ret,
					   bytenr, num_bytes, parent,
					   root_objectid, owner, offset, 0);
	if (ret != -ENOENT)
1629
		return ret;
1630

1631
	btrfs_release_path(path);
1632 1633 1634 1635 1636 1637 1638 1639
	*ref_ret = NULL;

	if (owner < BTRFS_FIRST_FREE_OBJECTID) {
		ret = lookup_tree_block_ref(trans, root, path, bytenr, parent,
					    root_objectid);
	} else {
		ret = lookup_extent_data_ref(trans, root, path, bytenr, parent,
					     root_objectid, owner, offset);
1640
	}
1641 1642
	return ret;
}
Z
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1643

1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686
/*
 * helper to update/remove inline back ref
 */
static noinline_for_stack
int update_inline_extent_backref(struct btrfs_trans_handle *trans,
				 struct btrfs_root *root,
				 struct btrfs_path *path,
				 struct btrfs_extent_inline_ref *iref,
				 int refs_to_mod,
				 struct btrfs_delayed_extent_op *extent_op)
{
	struct extent_buffer *leaf;
	struct btrfs_extent_item *ei;
	struct btrfs_extent_data_ref *dref = NULL;
	struct btrfs_shared_data_ref *sref = NULL;
	unsigned long ptr;
	unsigned long end;
	u32 item_size;
	int size;
	int type;
	int ret;
	u64 refs;

	leaf = path->nodes[0];
	ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
	refs = btrfs_extent_refs(leaf, ei);
	WARN_ON(refs_to_mod < 0 && refs + refs_to_mod <= 0);
	refs += refs_to_mod;
	btrfs_set_extent_refs(leaf, ei, refs);
	if (extent_op)
		__run_delayed_extent_op(extent_op, leaf, ei);

	type = btrfs_extent_inline_ref_type(leaf, iref);

	if (type == BTRFS_EXTENT_DATA_REF_KEY) {
		dref = (struct btrfs_extent_data_ref *)(&iref->offset);
		refs = btrfs_extent_data_ref_count(leaf, dref);
	} else if (type == BTRFS_SHARED_DATA_REF_KEY) {
		sref = (struct btrfs_shared_data_ref *)(iref + 1);
		refs = btrfs_shared_data_ref_count(leaf, sref);
	} else {
		refs = 1;
		BUG_ON(refs_to_mod != -1);
1687
	}
Z
Zheng Yan 已提交
1688

1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735
	BUG_ON(refs_to_mod < 0 && refs < -refs_to_mod);
	refs += refs_to_mod;

	if (refs > 0) {
		if (type == BTRFS_EXTENT_DATA_REF_KEY)
			btrfs_set_extent_data_ref_count(leaf, dref, refs);
		else
			btrfs_set_shared_data_ref_count(leaf, sref, refs);
	} else {
		size =  btrfs_extent_inline_ref_size(type);
		item_size = btrfs_item_size_nr(leaf, path->slots[0]);
		ptr = (unsigned long)iref;
		end = (unsigned long)ei + item_size;
		if (ptr + size < end)
			memmove_extent_buffer(leaf, ptr, ptr + size,
					      end - ptr - size);
		item_size -= size;
		ret = btrfs_truncate_item(trans, root, path, item_size, 1);
	}
	btrfs_mark_buffer_dirty(leaf);
	return 0;
}

static noinline_for_stack
int insert_inline_extent_backref(struct btrfs_trans_handle *trans,
				 struct btrfs_root *root,
				 struct btrfs_path *path,
				 u64 bytenr, u64 num_bytes, u64 parent,
				 u64 root_objectid, u64 owner,
				 u64 offset, int refs_to_add,
				 struct btrfs_delayed_extent_op *extent_op)
{
	struct btrfs_extent_inline_ref *iref;
	int ret;

	ret = lookup_inline_extent_backref(trans, root, path, &iref,
					   bytenr, num_bytes, parent,
					   root_objectid, owner, offset, 1);
	if (ret == 0) {
		BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID);
		ret = update_inline_extent_backref(trans, root, path, iref,
						   refs_to_add, extent_op);
	} else if (ret == -ENOENT) {
		ret = setup_inline_extent_backref(trans, root, path, iref,
						  parent, root_objectid,
						  owner, offset, refs_to_add,
						  extent_op);
1736
	}
1737 1738
	return ret;
}
Z
Zheng Yan 已提交
1739

1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757
static int insert_extent_backref(struct btrfs_trans_handle *trans,
				 struct btrfs_root *root,
				 struct btrfs_path *path,
				 u64 bytenr, u64 parent, u64 root_objectid,
				 u64 owner, u64 offset, int refs_to_add)
{
	int ret;
	if (owner < BTRFS_FIRST_FREE_OBJECTID) {
		BUG_ON(refs_to_add != 1);
		ret = insert_tree_block_ref(trans, root, path, bytenr,
					    parent, root_objectid);
	} else {
		ret = insert_extent_data_ref(trans, root, path, bytenr,
					     parent, root_objectid,
					     owner, offset, refs_to_add);
	}
	return ret;
}
1758

1759 1760 1761 1762 1763 1764 1765
static int remove_extent_backref(struct btrfs_trans_handle *trans,
				 struct btrfs_root *root,
				 struct btrfs_path *path,
				 struct btrfs_extent_inline_ref *iref,
				 int refs_to_drop, int is_data)
{
	int ret;
1766

1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778
	BUG_ON(!is_data && refs_to_drop != 1);
	if (iref) {
		ret = update_inline_extent_backref(trans, root, path, iref,
						   -refs_to_drop, NULL);
	} else if (is_data) {
		ret = remove_extent_data_ref(trans, root, path, refs_to_drop);
	} else {
		ret = btrfs_del_item(trans, root, path);
	}
	return ret;
}

1779
static int btrfs_issue_discard(struct block_device *bdev,
1780 1781
				u64 start, u64 len)
{
1782
	return blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_NOFS, 0);
1783 1784 1785
}

static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
1786
				u64 num_bytes, u64 *actual_bytes)
1787 1788
{
	int ret;
1789
	u64 discarded_bytes = 0;
1790 1791
	struct btrfs_multi_bio *multi = NULL;

C
Christoph Hellwig 已提交
1792

1793
	/* Tell the block device(s) that the sectors can be discarded */
1794 1795
	ret = btrfs_map_block(&root->fs_info->mapping_tree, REQ_DISCARD,
			      bytenr, &num_bytes, &multi, 0);
1796 1797 1798 1799 1800 1801
	if (!ret) {
		struct btrfs_bio_stripe *stripe = multi->stripes;
		int i;


		for (i = 0; i < multi->num_stripes; i++, stripe++) {
1802 1803 1804
			if (!stripe->dev->can_discard)
				continue;

1805 1806 1807 1808 1809 1810 1811
			ret = btrfs_issue_discard(stripe->dev->bdev,
						  stripe->physical,
						  stripe->length);
			if (!ret)
				discarded_bytes += stripe->length;
			else if (ret != -EOPNOTSUPP)
				break;
1812 1813 1814 1815 1816 1817 1818

			/*
			 * Just in case we get back EOPNOTSUPP for some reason,
			 * just ignore the return value so we don't screw up
			 * people calling discard_extent.
			 */
			ret = 0;
1819 1820 1821
		}
		kfree(multi);
	}
1822 1823 1824 1825

	if (actual_bytes)
		*actual_bytes = discarded_bytes;

1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889

	return ret;
}

int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
			 struct btrfs_root *root,
			 u64 bytenr, u64 num_bytes, u64 parent,
			 u64 root_objectid, u64 owner, u64 offset)
{
	int ret;
	BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID &&
	       root_objectid == BTRFS_TREE_LOG_OBJECTID);

	if (owner < BTRFS_FIRST_FREE_OBJECTID) {
		ret = btrfs_add_delayed_tree_ref(trans, bytenr, num_bytes,
					parent, root_objectid, (int)owner,
					BTRFS_ADD_DELAYED_REF, NULL);
	} else {
		ret = btrfs_add_delayed_data_ref(trans, bytenr, num_bytes,
					parent, root_objectid, owner, offset,
					BTRFS_ADD_DELAYED_REF, NULL);
	}
	return ret;
}

static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
				  struct btrfs_root *root,
				  u64 bytenr, u64 num_bytes,
				  u64 parent, u64 root_objectid,
				  u64 owner, u64 offset, int refs_to_add,
				  struct btrfs_delayed_extent_op *extent_op)
{
	struct btrfs_path *path;
	struct extent_buffer *leaf;
	struct btrfs_extent_item *item;
	u64 refs;
	int ret;
	int err = 0;

	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;

	path->reada = 1;
	path->leave_spinning = 1;
	/* this will setup the path even if it fails to insert the back ref */
	ret = insert_inline_extent_backref(trans, root->fs_info->extent_root,
					   path, bytenr, num_bytes, parent,
					   root_objectid, owner, offset,
					   refs_to_add, extent_op);
	if (ret == 0)
		goto out;

	if (ret != -EAGAIN) {
		err = ret;
		goto out;
	}

	leaf = path->nodes[0];
	item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
	refs = btrfs_extent_refs(leaf, item);
	btrfs_set_extent_refs(leaf, item, refs + refs_to_add);
	if (extent_op)
		__run_delayed_extent_op(extent_op, leaf, item);
1890

1891
	btrfs_mark_buffer_dirty(leaf);
1892
	btrfs_release_path(path);
1893 1894

	path->reada = 1;
1895 1896
	path->leave_spinning = 1;

1897 1898
	/* now insert the actual backref */
	ret = insert_extent_backref(trans, root->fs_info->extent_root,
1899 1900
				    path, bytenr, parent, root_objectid,
				    owner, offset, refs_to_add);
1901
	BUG_ON(ret);
1902
out:
1903
	btrfs_free_path(path);
1904
	return err;
1905 1906
}

1907 1908 1909 1910 1911
static int run_delayed_data_ref(struct btrfs_trans_handle *trans,
				struct btrfs_root *root,
				struct btrfs_delayed_ref_node *node,
				struct btrfs_delayed_extent_op *extent_op,
				int insert_reserved)
1912
{
1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984
	int ret = 0;
	struct btrfs_delayed_data_ref *ref;
	struct btrfs_key ins;
	u64 parent = 0;
	u64 ref_root = 0;
	u64 flags = 0;

	ins.objectid = node->bytenr;
	ins.offset = node->num_bytes;
	ins.type = BTRFS_EXTENT_ITEM_KEY;

	ref = btrfs_delayed_node_to_data_ref(node);
	if (node->type == BTRFS_SHARED_DATA_REF_KEY)
		parent = ref->parent;
	else
		ref_root = ref->root;

	if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
		if (extent_op) {
			BUG_ON(extent_op->update_key);
			flags |= extent_op->flags_to_set;
		}
		ret = alloc_reserved_file_extent(trans, root,
						 parent, ref_root, flags,
						 ref->objectid, ref->offset,
						 &ins, node->ref_mod);
	} else if (node->action == BTRFS_ADD_DELAYED_REF) {
		ret = __btrfs_inc_extent_ref(trans, root, node->bytenr,
					     node->num_bytes, parent,
					     ref_root, ref->objectid,
					     ref->offset, node->ref_mod,
					     extent_op);
	} else if (node->action == BTRFS_DROP_DELAYED_REF) {
		ret = __btrfs_free_extent(trans, root, node->bytenr,
					  node->num_bytes, parent,
					  ref_root, ref->objectid,
					  ref->offset, node->ref_mod,
					  extent_op);
	} else {
		BUG();
	}
	return ret;
}

static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
				    struct extent_buffer *leaf,
				    struct btrfs_extent_item *ei)
{
	u64 flags = btrfs_extent_flags(leaf, ei);
	if (extent_op->update_flags) {
		flags |= extent_op->flags_to_set;
		btrfs_set_extent_flags(leaf, ei, flags);
	}

	if (extent_op->update_key) {
		struct btrfs_tree_block_info *bi;
		BUG_ON(!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK));
		bi = (struct btrfs_tree_block_info *)(ei + 1);
		btrfs_set_tree_block_key(leaf, bi, &extent_op->key);
	}
}

static int run_delayed_extent_op(struct btrfs_trans_handle *trans,
				 struct btrfs_root *root,
				 struct btrfs_delayed_ref_node *node,
				 struct btrfs_delayed_extent_op *extent_op)
{
	struct btrfs_key key;
	struct btrfs_path *path;
	struct btrfs_extent_item *ei;
	struct extent_buffer *leaf;
	u32 item_size;
1985
	int ret;
1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025
	int err = 0;

	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;

	key.objectid = node->bytenr;
	key.type = BTRFS_EXTENT_ITEM_KEY;
	key.offset = node->num_bytes;

	path->reada = 1;
	path->leave_spinning = 1;
	ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key,
				path, 0, 1);
	if (ret < 0) {
		err = ret;
		goto out;
	}
	if (ret > 0) {
		err = -EIO;
		goto out;
	}

	leaf = path->nodes[0];
	item_size = btrfs_item_size_nr(leaf, path->slots[0]);
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
	if (item_size < sizeof(*ei)) {
		ret = convert_extent_item_v0(trans, root->fs_info->extent_root,
					     path, (u64)-1, 0);
		if (ret < 0) {
			err = ret;
			goto out;
		}
		leaf = path->nodes[0];
		item_size = btrfs_item_size_nr(leaf, path->slots[0]);
	}
#endif
	BUG_ON(item_size < sizeof(*ei));
	ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
	__run_delayed_extent_op(extent_op, leaf, ei);
2026

2027 2028 2029 2030
	btrfs_mark_buffer_dirty(leaf);
out:
	btrfs_free_path(path);
	return err;
2031 2032
}

2033 2034 2035 2036 2037
static int run_delayed_tree_ref(struct btrfs_trans_handle *trans,
				struct btrfs_root *root,
				struct btrfs_delayed_ref_node *node,
				struct btrfs_delayed_extent_op *extent_op,
				int insert_reserved)
2038 2039
{
	int ret = 0;
2040 2041 2042 2043
	struct btrfs_delayed_tree_ref *ref;
	struct btrfs_key ins;
	u64 parent = 0;
	u64 ref_root = 0;
2044

2045 2046 2047
	ins.objectid = node->bytenr;
	ins.offset = node->num_bytes;
	ins.type = BTRFS_EXTENT_ITEM_KEY;
2048

2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074
	ref = btrfs_delayed_node_to_tree_ref(node);
	if (node->type == BTRFS_SHARED_BLOCK_REF_KEY)
		parent = ref->parent;
	else
		ref_root = ref->root;

	BUG_ON(node->ref_mod != 1);
	if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
		BUG_ON(!extent_op || !extent_op->update_flags ||
		       !extent_op->update_key);
		ret = alloc_reserved_tree_block(trans, root,
						parent, ref_root,
						extent_op->flags_to_set,
						&extent_op->key,
						ref->level, &ins);
	} else if (node->action == BTRFS_ADD_DELAYED_REF) {
		ret = __btrfs_inc_extent_ref(trans, root, node->bytenr,
					     node->num_bytes, parent, ref_root,
					     ref->level, 0, 1, extent_op);
	} else if (node->action == BTRFS_DROP_DELAYED_REF) {
		ret = __btrfs_free_extent(trans, root, node->bytenr,
					  node->num_bytes, parent, ref_root,
					  ref->level, 0, 1, extent_op);
	} else {
		BUG();
	}
2075 2076 2077 2078
	return ret;
}

/* helper function to actually process a single delayed ref entry */
2079 2080 2081 2082 2083
static int run_one_delayed_ref(struct btrfs_trans_handle *trans,
			       struct btrfs_root *root,
			       struct btrfs_delayed_ref_node *node,
			       struct btrfs_delayed_extent_op *extent_op,
			       int insert_reserved)
2084 2085
{
	int ret;
2086
	if (btrfs_delayed_ref_is_head(node)) {
2087 2088 2089 2090 2091 2092 2093
		struct btrfs_delayed_ref_head *head;
		/*
		 * we've hit the end of the chain and we were supposed
		 * to insert this extent into the tree.  But, it got
		 * deleted before we ever needed to insert it, so all
		 * we have to do is clean up the accounting
		 */
2094 2095
		BUG_ON(extent_op);
		head = btrfs_delayed_node_to_head(node);
2096
		if (insert_reserved) {
2097 2098
			btrfs_pin_extent(root, node->bytenr,
					 node->num_bytes, 1);
2099 2100 2101 2102 2103 2104
			if (head->is_data) {
				ret = btrfs_del_csums(trans, root,
						      node->bytenr,
						      node->num_bytes);
				BUG_ON(ret);
			}
2105 2106 2107 2108 2109
		}
		mutex_unlock(&head->mutex);
		return 0;
	}

2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120
	if (node->type == BTRFS_TREE_BLOCK_REF_KEY ||
	    node->type == BTRFS_SHARED_BLOCK_REF_KEY)
		ret = run_delayed_tree_ref(trans, root, node, extent_op,
					   insert_reserved);
	else if (node->type == BTRFS_EXTENT_DATA_REF_KEY ||
		 node->type == BTRFS_SHARED_DATA_REF_KEY)
		ret = run_delayed_data_ref(trans, root, node, extent_op,
					   insert_reserved);
	else
		BUG();
	return ret;
2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142
}

static noinline struct btrfs_delayed_ref_node *
select_delayed_ref(struct btrfs_delayed_ref_head *head)
{
	struct rb_node *node;
	struct btrfs_delayed_ref_node *ref;
	int action = BTRFS_ADD_DELAYED_REF;
again:
	/*
	 * select delayed ref of type BTRFS_ADD_DELAYED_REF first.
	 * this prevents ref count from going down to zero when
	 * there still are pending delayed ref.
	 */
	node = rb_prev(&head->node.rb_node);
	while (1) {
		if (!node)
			break;
		ref = rb_entry(node, struct btrfs_delayed_ref_node,
				rb_node);
		if (ref->bytenr != head->node.bytenr)
			break;
2143
		if (ref->action == action)
2144 2145 2146 2147 2148 2149 2150 2151 2152 2153
			return ref;
		node = rb_prev(node);
	}
	if (action == BTRFS_ADD_DELAYED_REF) {
		action = BTRFS_DROP_DELAYED_REF;
		goto again;
	}
	return NULL;
}

2154 2155 2156
static noinline int run_clustered_refs(struct btrfs_trans_handle *trans,
				       struct btrfs_root *root,
				       struct list_head *cluster)
2157 2158 2159 2160
{
	struct btrfs_delayed_ref_root *delayed_refs;
	struct btrfs_delayed_ref_node *ref;
	struct btrfs_delayed_ref_head *locked_ref = NULL;
2161
	struct btrfs_delayed_extent_op *extent_op;
2162
	int ret;
2163
	int count = 0;
2164 2165 2166 2167 2168
	int must_insert_reserved = 0;

	delayed_refs = &trans->transaction->delayed_refs;
	while (1) {
		if (!locked_ref) {
2169 2170
			/* pick a new head ref from the cluster list */
			if (list_empty(cluster))
2171 2172
				break;

2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189
			locked_ref = list_entry(cluster->next,
				     struct btrfs_delayed_ref_head, cluster);

			/* grab the lock that says we are going to process
			 * all the refs for this head */
			ret = btrfs_delayed_ref_lock(trans, locked_ref);

			/*
			 * we may have dropped the spin lock to get the head
			 * mutex lock, and that might have given someone else
			 * time to free the head.  If that's true, it has been
			 * removed from our list and we can move on.
			 */
			if (ret == -EAGAIN) {
				locked_ref = NULL;
				count++;
				continue;
2190 2191
			}
		}
2192

2193 2194 2195 2196 2197 2198
		/*
		 * record the must insert reserved flag before we
		 * drop the spin lock.
		 */
		must_insert_reserved = locked_ref->must_insert_reserved;
		locked_ref->must_insert_reserved = 0;
2199

2200 2201 2202
		extent_op = locked_ref->extent_op;
		locked_ref->extent_op = NULL;

2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213
		/*
		 * locked_ref is the head node, so we have to go one
		 * node back for any delayed ref updates
		 */
		ref = select_delayed_ref(locked_ref);
		if (!ref) {
			/* All delayed refs have been processed, Go ahead
			 * and send the head node to run_one_delayed_ref,
			 * so that any accounting fixes can happen
			 */
			ref = &locked_ref->node;
2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232

			if (extent_op && must_insert_reserved) {
				kfree(extent_op);
				extent_op = NULL;
			}

			if (extent_op) {
				spin_unlock(&delayed_refs->lock);

				ret = run_delayed_extent_op(trans, root,
							    ref, extent_op);
				BUG_ON(ret);
				kfree(extent_op);

				cond_resched();
				spin_lock(&delayed_refs->lock);
				continue;
			}

2233
			list_del_init(&locked_ref->cluster);
2234 2235
			locked_ref = NULL;
		}
C
Chris Mason 已提交
2236

2237 2238 2239
		ref->in_tree = 0;
		rb_erase(&ref->rb_node, &delayed_refs->root);
		delayed_refs->num_entries--;
2240

2241
		spin_unlock(&delayed_refs->lock);
2242

2243
		ret = run_one_delayed_ref(trans, root, ref, extent_op,
2244 2245
					  must_insert_reserved);
		BUG_ON(ret);
2246

2247 2248
		btrfs_put_delayed_ref(ref);
		kfree(extent_op);
2249
		count++;
2250

2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289
		cond_resched();
		spin_lock(&delayed_refs->lock);
	}
	return count;
}

/*
 * this starts processing the delayed reference count updates and
 * extent insertions we have queued up so far.  count can be
 * 0, which means to process everything in the tree at the start
 * of the run (but not newly added entries), or it can be some target
 * number you'd like to process.
 */
int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
			   struct btrfs_root *root, unsigned long count)
{
	struct rb_node *node;
	struct btrfs_delayed_ref_root *delayed_refs;
	struct btrfs_delayed_ref_node *ref;
	struct list_head cluster;
	int ret;
	int run_all = count == (unsigned long)-1;
	int run_most = 0;

	if (root == root->fs_info->extent_root)
		root = root->fs_info->tree_root;

	delayed_refs = &trans->transaction->delayed_refs;
	INIT_LIST_HEAD(&cluster);
again:
	spin_lock(&delayed_refs->lock);
	if (count == 0) {
		count = delayed_refs->num_entries * 2;
		run_most = 1;
	}
	while (1) {
		if (!(run_all || run_most) &&
		    delayed_refs->num_heads_ready < 64)
			break;
2290

2291
		/*
2292 2293 2294 2295
		 * go find something we can process in the rbtree.  We start at
		 * the beginning of the tree, and then build a cluster
		 * of refs to process starting at the first one we are able to
		 * lock
2296
		 */
2297 2298 2299
		ret = btrfs_find_ref_cluster(trans, &cluster,
					     delayed_refs->run_delayed_start);
		if (ret)
2300 2301
			break;

2302 2303 2304 2305 2306 2307 2308
		ret = run_clustered_refs(trans, root, &cluster);
		BUG_ON(ret < 0);

		count -= min_t(unsigned long, ret, count);

		if (count == 0)
			break;
2309
	}
2310

2311 2312
	if (run_all) {
		node = rb_first(&delayed_refs->root);
2313
		if (!node)
2314
			goto out;
2315
		count = (unsigned long)-1;
2316

2317 2318 2319 2320 2321
		while (node) {
			ref = rb_entry(node, struct btrfs_delayed_ref_node,
				       rb_node);
			if (btrfs_delayed_ref_is_head(ref)) {
				struct btrfs_delayed_ref_head *head;
2322

2323 2324 2325 2326
				head = btrfs_delayed_node_to_head(ref);
				atomic_inc(&ref->refs);

				spin_unlock(&delayed_refs->lock);
2327 2328 2329 2330
				/*
				 * Mutex was contended, block until it's
				 * released and try again
				 */
2331 2332 2333 2334
				mutex_lock(&head->mutex);
				mutex_unlock(&head->mutex);

				btrfs_put_delayed_ref(ref);
2335
				cond_resched();
2336 2337 2338 2339 2340 2341 2342
				goto again;
			}
			node = rb_next(node);
		}
		spin_unlock(&delayed_refs->lock);
		schedule_timeout(1);
		goto again;
2343
	}
2344
out:
2345
	spin_unlock(&delayed_refs->lock);
2346 2347 2348
	return 0;
}

2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394
int btrfs_set_disk_extent_flags(struct btrfs_trans_handle *trans,
				struct btrfs_root *root,
				u64 bytenr, u64 num_bytes, u64 flags,
				int is_data)
{
	struct btrfs_delayed_extent_op *extent_op;
	int ret;

	extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
	if (!extent_op)
		return -ENOMEM;

	extent_op->flags_to_set = flags;
	extent_op->update_flags = 1;
	extent_op->update_key = 0;
	extent_op->is_data = is_data ? 1 : 0;

	ret = btrfs_add_delayed_extent_op(trans, bytenr, num_bytes, extent_op);
	if (ret)
		kfree(extent_op);
	return ret;
}

static noinline int check_delayed_ref(struct btrfs_trans_handle *trans,
				      struct btrfs_root *root,
				      struct btrfs_path *path,
				      u64 objectid, u64 offset, u64 bytenr)
{
	struct btrfs_delayed_ref_head *head;
	struct btrfs_delayed_ref_node *ref;
	struct btrfs_delayed_data_ref *data_ref;
	struct btrfs_delayed_ref_root *delayed_refs;
	struct rb_node *node;
	int ret = 0;

	ret = -ENOENT;
	delayed_refs = &trans->transaction->delayed_refs;
	spin_lock(&delayed_refs->lock);
	head = btrfs_find_delayed_ref_head(trans, bytenr);
	if (!head)
		goto out;

	if (!mutex_trylock(&head->mutex)) {
		atomic_inc(&head->node.refs);
		spin_unlock(&delayed_refs->lock);

2395
		btrfs_release_path(path);
2396

2397 2398 2399 2400
		/*
		 * Mutex was contended, block until it's released and let
		 * caller try again
		 */
2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444
		mutex_lock(&head->mutex);
		mutex_unlock(&head->mutex);
		btrfs_put_delayed_ref(&head->node);
		return -EAGAIN;
	}

	node = rb_prev(&head->node.rb_node);
	if (!node)
		goto out_unlock;

	ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);

	if (ref->bytenr != bytenr)
		goto out_unlock;

	ret = 1;
	if (ref->type != BTRFS_EXTENT_DATA_REF_KEY)
		goto out_unlock;

	data_ref = btrfs_delayed_node_to_data_ref(ref);

	node = rb_prev(node);
	if (node) {
		ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
		if (ref->bytenr == bytenr)
			goto out_unlock;
	}

	if (data_ref->root != root->root_key.objectid ||
	    data_ref->objectid != objectid || data_ref->offset != offset)
		goto out_unlock;

	ret = 0;
out_unlock:
	mutex_unlock(&head->mutex);
out:
	spin_unlock(&delayed_refs->lock);
	return ret;
}

static noinline int check_committed_ref(struct btrfs_trans_handle *trans,
					struct btrfs_root *root,
					struct btrfs_path *path,
					u64 objectid, u64 offset, u64 bytenr)
2445 2446
{
	struct btrfs_root *extent_root = root->fs_info->extent_root;
2447
	struct extent_buffer *leaf;
2448 2449 2450
	struct btrfs_extent_data_ref *ref;
	struct btrfs_extent_inline_ref *iref;
	struct btrfs_extent_item *ei;
2451
	struct btrfs_key key;
2452
	u32 item_size;
2453
	int ret;
2454

2455
	key.objectid = bytenr;
Z
Zheng Yan 已提交
2456
	key.offset = (u64)-1;
2457
	key.type = BTRFS_EXTENT_ITEM_KEY;
2458 2459 2460 2461 2462

	ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
	if (ret < 0)
		goto out;
	BUG_ON(ret == 0);
Y
Yan Zheng 已提交
2463 2464 2465

	ret = -ENOENT;
	if (path->slots[0] == 0)
Z
Zheng Yan 已提交
2466
		goto out;
2467

Z
Zheng Yan 已提交
2468
	path->slots[0]--;
2469
	leaf = path->nodes[0];
2470
	btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
2471

2472
	if (key.objectid != bytenr || key.type != BTRFS_EXTENT_ITEM_KEY)
2473
		goto out;
2474

2475 2476 2477 2478 2479 2480 2481 2482 2483
	ret = 1;
	item_size = btrfs_item_size_nr(leaf, path->slots[0]);
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
	if (item_size < sizeof(*ei)) {
		WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0));
		goto out;
	}
#endif
	ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
2484

2485 2486 2487
	if (item_size != sizeof(*ei) +
	    btrfs_extent_inline_ref_size(BTRFS_EXTENT_DATA_REF_KEY))
		goto out;
2488

2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 2527
	if (btrfs_extent_generation(leaf, ei) <=
	    btrfs_root_last_snapshot(&root->root_item))
		goto out;

	iref = (struct btrfs_extent_inline_ref *)(ei + 1);
	if (btrfs_extent_inline_ref_type(leaf, iref) !=
	    BTRFS_EXTENT_DATA_REF_KEY)
		goto out;

	ref = (struct btrfs_extent_data_ref *)(&iref->offset);
	if (btrfs_extent_refs(leaf, ei) !=
	    btrfs_extent_data_ref_count(leaf, ref) ||
	    btrfs_extent_data_ref_root(leaf, ref) !=
	    root->root_key.objectid ||
	    btrfs_extent_data_ref_objectid(leaf, ref) != objectid ||
	    btrfs_extent_data_ref_offset(leaf, ref) != offset)
		goto out;

	ret = 0;
out:
	return ret;
}

int btrfs_cross_ref_exist(struct btrfs_trans_handle *trans,
			  struct btrfs_root *root,
			  u64 objectid, u64 offset, u64 bytenr)
{
	struct btrfs_path *path;
	int ret;
	int ret2;

	path = btrfs_alloc_path();
	if (!path)
		return -ENOENT;

	do {
		ret = check_committed_ref(trans, root, path, objectid,
					  offset, bytenr);
		if (ret && ret != -ENOENT)
2528
			goto out;
Y
Yan Zheng 已提交
2529

2530 2531 2532 2533 2534 2535 2536
		ret2 = check_delayed_ref(trans, root, path, objectid,
					 offset, bytenr);
	} while (ret2 == -EAGAIN);

	if (ret2 && ret2 != -ENOENT) {
		ret = ret2;
		goto out;
2537
	}
2538 2539 2540

	if (ret != -ENOENT || ret2 != -ENOENT)
		ret = 0;
2541
out:
Y
Yan Zheng 已提交
2542
	btrfs_free_path(path);
2543 2544
	if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
		WARN_ON(ret > 0);
2545
	return ret;
2546
}
C
Chris Mason 已提交
2547

2548
static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
2549
			   struct btrfs_root *root,
2550 2551
			   struct extent_buffer *buf,
			   int full_backref, int inc)
Z
Zheng Yan 已提交
2552 2553
{
	u64 bytenr;
2554 2555
	u64 num_bytes;
	u64 parent;
Z
Zheng Yan 已提交
2556 2557 2558 2559 2560 2561 2562 2563
	u64 ref_root;
	u32 nritems;
	struct btrfs_key key;
	struct btrfs_file_extent_item *fi;
	int i;
	int level;
	int ret = 0;
	int (*process_func)(struct btrfs_trans_handle *, struct btrfs_root *,
2564
			    u64, u64, u64, u64, u64, u64);
Z
Zheng Yan 已提交
2565 2566 2567 2568 2569

	ref_root = btrfs_header_owner(buf);
	nritems = btrfs_header_nritems(buf);
	level = btrfs_header_level(buf);

2570 2571
	if (!root->ref_cows && level == 0)
		return 0;
Z
Zheng Yan 已提交
2572

2573 2574 2575 2576
	if (inc)
		process_func = btrfs_inc_extent_ref;
	else
		process_func = btrfs_free_extent;
Z
Zheng Yan 已提交
2577

2578 2579 2580 2581 2582 2583
	if (full_backref)
		parent = buf->start;
	else
		parent = 0;

	for (i = 0; i < nritems; i++) {
Z
Zheng Yan 已提交
2584
		if (level == 0) {
2585
			btrfs_item_key_to_cpu(buf, &key, i);
Z
Zheng Yan 已提交
2586 2587
			if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
				continue;
2588
			fi = btrfs_item_ptr(buf, i,
Z
Zheng Yan 已提交
2589 2590 2591 2592 2593 2594 2595
					    struct btrfs_file_extent_item);
			if (btrfs_file_extent_type(buf, fi) ==
			    BTRFS_FILE_EXTENT_INLINE)
				continue;
			bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
			if (bytenr == 0)
				continue;
2596 2597 2598 2599 2600 2601

			num_bytes = btrfs_file_extent_disk_num_bytes(buf, fi);
			key.offset -= btrfs_file_extent_offset(buf, fi);
			ret = process_func(trans, root, bytenr, num_bytes,
					   parent, ref_root, key.objectid,
					   key.offset);
Z
Zheng Yan 已提交
2602 2603 2604
			if (ret)
				goto fail;
		} else {
2605 2606 2607 2608
			bytenr = btrfs_node_blockptr(buf, i);
			num_bytes = btrfs_level_size(root, level - 1);
			ret = process_func(trans, root, bytenr, num_bytes,
					   parent, ref_root, level - 1, 0);
Z
Zheng Yan 已提交
2609 2610 2611 2612 2613 2614
			if (ret)
				goto fail;
		}
	}
	return 0;
fail:
2615 2616 2617 2618 2619 2620 2621 2622 2623 2624 2625 2626 2627 2628
	BUG();
	return ret;
}

int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
		  struct extent_buffer *buf, int full_backref)
{
	return __btrfs_mod_ref(trans, root, buf, full_backref, 1);
}

int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
		  struct extent_buffer *buf, int full_backref)
{
	return __btrfs_mod_ref(trans, root, buf, full_backref, 0);
Z
Zheng Yan 已提交
2629 2630
}

C
Chris Mason 已提交
2631 2632 2633 2634 2635 2636 2637
static int write_one_cache_group(struct btrfs_trans_handle *trans,
				 struct btrfs_root *root,
				 struct btrfs_path *path,
				 struct btrfs_block_group_cache *cache)
{
	int ret;
	struct btrfs_root *extent_root = root->fs_info->extent_root;
2638 2639
	unsigned long bi;
	struct extent_buffer *leaf;
C
Chris Mason 已提交
2640 2641

	ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
2642 2643
	if (ret < 0)
		goto fail;
C
Chris Mason 已提交
2644
	BUG_ON(ret);
2645 2646 2647 2648 2649

	leaf = path->nodes[0];
	bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
	write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
	btrfs_mark_buffer_dirty(leaf);
2650
	btrfs_release_path(path);
2651
fail:
C
Chris Mason 已提交
2652 2653 2654 2655 2656 2657
	if (ret)
		return ret;
	return 0;

}

2658 2659 2660 2661 2662 2663 2664 2665 2666 2667 2668
static struct btrfs_block_group_cache *
next_block_group(struct btrfs_root *root,
		 struct btrfs_block_group_cache *cache)
{
	struct rb_node *node;
	spin_lock(&root->fs_info->block_group_cache_lock);
	node = rb_next(&cache->cache_node);
	btrfs_put_block_group(cache);
	if (node) {
		cache = rb_entry(node, struct btrfs_block_group_cache,
				 cache_node);
2669
		btrfs_get_block_group(cache);
2670 2671 2672 2673 2674 2675
	} else
		cache = NULL;
	spin_unlock(&root->fs_info->block_group_cache_lock);
	return cache;
}

2676 2677 2678 2679 2680 2681 2682
static int cache_save_setup(struct btrfs_block_group_cache *block_group,
			    struct btrfs_trans_handle *trans,
			    struct btrfs_path *path)
{
	struct btrfs_root *root = block_group->fs_info->tree_root;
	struct inode *inode = NULL;
	u64 alloc_hint = 0;
2683
	int dcs = BTRFS_DC_ERROR;
2684 2685 2686 2687 2688 2689 2690 2691 2692 2693 2694 2695 2696 2697 2698 2699 2700 2701 2702
	int num_pages = 0;
	int retries = 0;
	int ret = 0;

	/*
	 * If this block group is smaller than 100 megs don't bother caching the
	 * block group.
	 */
	if (block_group->key.offset < (100 * 1024 * 1024)) {
		spin_lock(&block_group->lock);
		block_group->disk_cache_state = BTRFS_DC_WRITTEN;
		spin_unlock(&block_group->lock);
		return 0;
	}

again:
	inode = lookup_free_space_inode(root, block_group, path);
	if (IS_ERR(inode) && PTR_ERR(inode) != -ENOENT) {
		ret = PTR_ERR(inode);
2703
		btrfs_release_path(path);
2704 2705 2706 2707 2708 2709 2710 2711 2712 2713 2714 2715 2716 2717 2718 2719
		goto out;
	}

	if (IS_ERR(inode)) {
		BUG_ON(retries);
		retries++;

		if (block_group->ro)
			goto out_free;

		ret = create_free_space_inode(root, trans, block_group, path);
		if (ret)
			goto out_free;
		goto again;
	}

2720 2721 2722 2723 2724 2725 2726
	/* We've already setup this transaction, go ahead and exit */
	if (block_group->cache_generation == trans->transid &&
	    i_size_read(inode)) {
		dcs = BTRFS_DC_SETUP;
		goto out_put;
	}

2727 2728 2729 2730 2731 2732 2733 2734 2735 2736 2737 2738 2739 2740 2741 2742 2743 2744
	/*
	 * We want to set the generation to 0, that way if anything goes wrong
	 * from here on out we know not to trust this cache when we load up next
	 * time.
	 */
	BTRFS_I(inode)->generation = 0;
	ret = btrfs_update_inode(trans, root, inode);
	WARN_ON(ret);

	if (i_size_read(inode) > 0) {
		ret = btrfs_truncate_free_space_cache(root, trans, path,
						      inode);
		if (ret)
			goto out_put;
	}

	spin_lock(&block_group->lock);
	if (block_group->cached != BTRFS_CACHE_FINISHED) {
2745 2746
		/* We're not cached, don't bother trying to write stuff out */
		dcs = BTRFS_DC_WRITTEN;
2747 2748 2749 2750 2751 2752 2753 2754 2755 2756 2757 2758 2759 2760 2761 2762 2763 2764 2765
		spin_unlock(&block_group->lock);
		goto out_put;
	}
	spin_unlock(&block_group->lock);

	num_pages = (int)div64_u64(block_group->key.offset, 1024 * 1024 * 1024);
	if (!num_pages)
		num_pages = 1;

	/*
	 * Just to make absolutely sure we have enough space, we're going to
	 * preallocate 12 pages worth of space for each block group.  In
	 * practice we ought to use at most 8, but we need extra space so we can
	 * add our header and have a terminator between the extents and the
	 * bitmaps.
	 */
	num_pages *= 16;
	num_pages *= PAGE_CACHE_SIZE;

2766
	ret = btrfs_check_data_free_space(inode, num_pages);
2767 2768 2769 2770 2771 2772
	if (ret)
		goto out_put;

	ret = btrfs_prealloc_file_range_trans(inode, trans, 0, 0, num_pages,
					      num_pages, num_pages,
					      &alloc_hint);
2773
	if (!ret)
2774
		dcs = BTRFS_DC_SETUP;
2775
	btrfs_free_reserved_data_space(inode, num_pages);
2776

2777 2778 2779
out_put:
	iput(inode);
out_free:
2780
	btrfs_release_path(path);
2781 2782
out:
	spin_lock(&block_group->lock);
2783 2784
	if (!ret)
		block_group->cache_generation = trans->transid;
2785
	block_group->disk_cache_state = dcs;
2786 2787 2788 2789 2790
	spin_unlock(&block_group->lock);

	return ret;
}

2791 2792
int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
				   struct btrfs_root *root)
C
Chris Mason 已提交
2793
{
2794
	struct btrfs_block_group_cache *cache;
C
Chris Mason 已提交
2795 2796
	int err = 0;
	struct btrfs_path *path;
2797
	u64 last = 0;
C
Chris Mason 已提交
2798 2799 2800 2801 2802

	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;

2803 2804 2805 2806 2807 2808 2809 2810 2811 2812 2813 2814 2815 2816 2817 2818 2819 2820 2821
again:
	while (1) {
		cache = btrfs_lookup_first_block_group(root->fs_info, last);
		while (cache) {
			if (cache->disk_cache_state == BTRFS_DC_CLEAR)
				break;
			cache = next_block_group(root, cache);
		}
		if (!cache) {
			if (last == 0)
				break;
			last = 0;
			continue;
		}
		err = cache_save_setup(cache, trans, path);
		last = cache->key.objectid + cache->key.offset;
		btrfs_put_block_group(cache);
	}

C
Chris Mason 已提交
2822
	while (1) {
2823 2824 2825 2826
		if (last == 0) {
			err = btrfs_run_delayed_refs(trans, root,
						     (unsigned long)-1);
			BUG_ON(err);
J
Josef Bacik 已提交
2827
		}
2828

2829 2830
		cache = btrfs_lookup_first_block_group(root->fs_info, last);
		while (cache) {
2831 2832 2833 2834 2835
			if (cache->disk_cache_state == BTRFS_DC_CLEAR) {
				btrfs_put_block_group(cache);
				goto again;
			}

2836 2837 2838 2839 2840 2841 2842 2843 2844 2845
			if (cache->dirty)
				break;
			cache = next_block_group(root, cache);
		}
		if (!cache) {
			if (last == 0)
				break;
			last = 0;
			continue;
		}
J
Josef Bacik 已提交
2846

J
Josef Bacik 已提交
2847 2848
		if (cache->disk_cache_state == BTRFS_DC_SETUP)
			cache->disk_cache_state = BTRFS_DC_NEED_WRITE;
2849
		cache->dirty = 0;
2850
		last = cache->key.objectid + cache->key.offset;
J
Josef Bacik 已提交
2851

2852 2853 2854
		err = write_one_cache_group(trans, root, path, cache);
		BUG_ON(err);
		btrfs_put_block_group(cache);
C
Chris Mason 已提交
2855
	}
2856

J
Josef Bacik 已提交
2857 2858 2859 2860 2861 2862 2863 2864 2865 2866 2867 2868 2869 2870 2871 2872 2873 2874 2875 2876 2877 2878 2879 2880 2881 2882 2883 2884 2885 2886 2887 2888 2889 2890 2891 2892 2893 2894 2895 2896 2897 2898 2899 2900 2901 2902
	while (1) {
		/*
		 * I don't think this is needed since we're just marking our
		 * preallocated extent as written, but just in case it can't
		 * hurt.
		 */
		if (last == 0) {
			err = btrfs_run_delayed_refs(trans, root,
						     (unsigned long)-1);
			BUG_ON(err);
		}

		cache = btrfs_lookup_first_block_group(root->fs_info, last);
		while (cache) {
			/*
			 * Really this shouldn't happen, but it could if we
			 * couldn't write the entire preallocated extent and
			 * splitting the extent resulted in a new block.
			 */
			if (cache->dirty) {
				btrfs_put_block_group(cache);
				goto again;
			}
			if (cache->disk_cache_state == BTRFS_DC_NEED_WRITE)
				break;
			cache = next_block_group(root, cache);
		}
		if (!cache) {
			if (last == 0)
				break;
			last = 0;
			continue;
		}

		btrfs_write_out_cache(root, trans, cache, path);

		/*
		 * If we didn't have an error then the cache state is still
		 * NEED_WRITE, so we can set it to WRITTEN.
		 */
		if (cache->disk_cache_state == BTRFS_DC_NEED_WRITE)
			cache->disk_cache_state = BTRFS_DC_WRITTEN;
		last = cache->key.objectid + cache->key.offset;
		btrfs_put_block_group(cache);
	}

C
Chris Mason 已提交
2903
	btrfs_free_path(path);
2904
	return 0;
C
Chris Mason 已提交
2905 2906
}

2907 2908 2909 2910 2911 2912 2913 2914 2915
int btrfs_extent_readonly(struct btrfs_root *root, u64 bytenr)
{
	struct btrfs_block_group_cache *block_group;
	int readonly = 0;

	block_group = btrfs_lookup_block_group(root->fs_info, bytenr);
	if (!block_group || block_group->ro)
		readonly = 1;
	if (block_group)
2916
		btrfs_put_block_group(block_group);
2917 2918 2919
	return readonly;
}

2920 2921 2922 2923 2924
static int update_space_info(struct btrfs_fs_info *info, u64 flags,
			     u64 total_bytes, u64 bytes_used,
			     struct btrfs_space_info **space_info)
{
	struct btrfs_space_info *found;
2925 2926 2927 2928 2929 2930 2931 2932
	int i;
	int factor;

	if (flags & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
		     BTRFS_BLOCK_GROUP_RAID10))
		factor = 2;
	else
		factor = 1;
2933 2934 2935

	found = __find_space_info(info, flags);
	if (found) {
2936
		spin_lock(&found->lock);
2937
		found->total_bytes += total_bytes;
J
Josef Bacik 已提交
2938
		found->disk_total += total_bytes * factor;
2939
		found->bytes_used += bytes_used;
2940
		found->disk_used += bytes_used * factor;
2941
		found->full = 0;
2942
		spin_unlock(&found->lock);
2943 2944 2945
		*space_info = found;
		return 0;
	}
Y
Yan Zheng 已提交
2946
	found = kzalloc(sizeof(*found), GFP_NOFS);
2947 2948 2949
	if (!found)
		return -ENOMEM;

2950 2951
	for (i = 0; i < BTRFS_NR_RAID_TYPES; i++)
		INIT_LIST_HEAD(&found->block_groups[i]);
2952
	init_rwsem(&found->groups_sem);
J
Josef Bacik 已提交
2953
	spin_lock_init(&found->lock);
2954 2955 2956
	found->flags = flags & (BTRFS_BLOCK_GROUP_DATA |
				BTRFS_BLOCK_GROUP_SYSTEM |
				BTRFS_BLOCK_GROUP_METADATA);
2957
	found->total_bytes = total_bytes;
J
Josef Bacik 已提交
2958
	found->disk_total = total_bytes * factor;
2959
	found->bytes_used = bytes_used;
2960
	found->disk_used = bytes_used * factor;
2961
	found->bytes_pinned = 0;
2962
	found->bytes_reserved = 0;
Y
Yan Zheng 已提交
2963
	found->bytes_readonly = 0;
2964
	found->bytes_may_use = 0;
2965
	found->full = 0;
2966
	found->force_alloc = CHUNK_ALLOC_NO_FORCE;
2967
	found->chunk_alloc = 0;
2968 2969
	found->flush = 0;
	init_waitqueue_head(&found->wait);
2970
	*space_info = found;
2971
	list_add_rcu(&found->list, &info->space_info);
2972 2973 2974
	return 0;
}

2975 2976 2977
static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
{
	u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 |
2978
				   BTRFS_BLOCK_GROUP_RAID1 |
C
Chris Mason 已提交
2979
				   BTRFS_BLOCK_GROUP_RAID10 |
2980
				   BTRFS_BLOCK_GROUP_DUP);
2981 2982 2983 2984 2985 2986 2987 2988 2989
	if (extra_flags) {
		if (flags & BTRFS_BLOCK_GROUP_DATA)
			fs_info->avail_data_alloc_bits |= extra_flags;
		if (flags & BTRFS_BLOCK_GROUP_METADATA)
			fs_info->avail_metadata_alloc_bits |= extra_flags;
		if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
			fs_info->avail_system_alloc_bits |= extra_flags;
	}
}
2990

Y
Yan Zheng 已提交
2991
u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags)
2992
{
2993 2994 2995 2996 2997 2998 2999
	/*
	 * we add in the count of missing devices because we want
	 * to make sure that any RAID levels on a degraded FS
	 * continue to be honored.
	 */
	u64 num_devices = root->fs_info->fs_devices->rw_devices +
		root->fs_info->fs_devices->missing_devices;
3000 3001 3002 3003 3004 3005

	if (num_devices == 1)
		flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0);
	if (num_devices < 4)
		flags &= ~BTRFS_BLOCK_GROUP_RAID10;

3006 3007
	if ((flags & BTRFS_BLOCK_GROUP_DUP) &&
	    (flags & (BTRFS_BLOCK_GROUP_RAID1 |
3008
		      BTRFS_BLOCK_GROUP_RAID10))) {
3009
		flags &= ~BTRFS_BLOCK_GROUP_DUP;
3010
	}
3011 3012

	if ((flags & BTRFS_BLOCK_GROUP_RAID1) &&
3013
	    (flags & BTRFS_BLOCK_GROUP_RAID10)) {
3014
		flags &= ~BTRFS_BLOCK_GROUP_RAID1;
3015
	}
3016 3017 3018 3019 3020 3021 3022 3023 3024

	if ((flags & BTRFS_BLOCK_GROUP_RAID0) &&
	    ((flags & BTRFS_BLOCK_GROUP_RAID1) |
	     (flags & BTRFS_BLOCK_GROUP_RAID10) |
	     (flags & BTRFS_BLOCK_GROUP_DUP)))
		flags &= ~BTRFS_BLOCK_GROUP_RAID0;
	return flags;
}

3025
static u64 get_alloc_profile(struct btrfs_root *root, u64 flags)
J
Josef Bacik 已提交
3026
{
3027 3028 3029 3030 3031 3032 3033 3034 3035 3036
	if (flags & BTRFS_BLOCK_GROUP_DATA)
		flags |= root->fs_info->avail_data_alloc_bits &
			 root->fs_info->data_alloc_profile;
	else if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
		flags |= root->fs_info->avail_system_alloc_bits &
			 root->fs_info->system_alloc_profile;
	else if (flags & BTRFS_BLOCK_GROUP_METADATA)
		flags |= root->fs_info->avail_metadata_alloc_bits &
			 root->fs_info->metadata_alloc_profile;
	return btrfs_reduce_alloc_profile(root, flags);
J
Josef Bacik 已提交
3037 3038
}

3039
u64 btrfs_get_alloc_profile(struct btrfs_root *root, int data)
J
Josef Bacik 已提交
3040
{
3041
	u64 flags;
J
Josef Bacik 已提交
3042

3043 3044 3045 3046
	if (data)
		flags = BTRFS_BLOCK_GROUP_DATA;
	else if (root == root->fs_info->chunk_root)
		flags = BTRFS_BLOCK_GROUP_SYSTEM;
J
Josef Bacik 已提交
3047
	else
3048
		flags = BTRFS_BLOCK_GROUP_METADATA;
J
Josef Bacik 已提交
3049

3050
	return get_alloc_profile(root, flags);
J
Josef Bacik 已提交
3051
}
J
Josef Bacik 已提交
3052

J
Josef Bacik 已提交
3053 3054 3055
void btrfs_set_inode_space_info(struct btrfs_root *root, struct inode *inode)
{
	BTRFS_I(inode)->space_info = __find_space_info(root->fs_info,
3056
						       BTRFS_BLOCK_GROUP_DATA);
J
Josef Bacik 已提交
3057 3058
}

J
Josef Bacik 已提交
3059 3060 3061 3062
/*
 * This will check the space that the inode allocates from to make sure we have
 * enough space for bytes.
 */
3063
int btrfs_check_data_free_space(struct inode *inode, u64 bytes)
J
Josef Bacik 已提交
3064 3065
{
	struct btrfs_space_info *data_sinfo;
3066
	struct btrfs_root *root = BTRFS_I(inode)->root;
3067
	u64 used;
3068
	int ret = 0, committed = 0, alloc_chunk = 1;
J
Josef Bacik 已提交
3069 3070 3071 3072

	/* make sure bytes are sectorsize aligned */
	bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize - 1);

3073 3074
	if (root == root->fs_info->tree_root ||
	    BTRFS_I(inode)->location.objectid == BTRFS_FREE_INO_OBJECTID) {
3075 3076 3077 3078
		alloc_chunk = 0;
		committed = 1;
	}

J
Josef Bacik 已提交
3079
	data_sinfo = BTRFS_I(inode)->space_info;
C
Chris Mason 已提交
3080 3081
	if (!data_sinfo)
		goto alloc;
J
Josef Bacik 已提交
3082

J
Josef Bacik 已提交
3083 3084 3085
again:
	/* make sure we have enough space to handle the data first */
	spin_lock(&data_sinfo->lock);
3086 3087 3088
	used = data_sinfo->bytes_used + data_sinfo->bytes_reserved +
		data_sinfo->bytes_pinned + data_sinfo->bytes_readonly +
		data_sinfo->bytes_may_use;
3089 3090

	if (used + bytes > data_sinfo->total_bytes) {
3091
		struct btrfs_trans_handle *trans;
J
Josef Bacik 已提交
3092

J
Josef Bacik 已提交
3093 3094 3095 3096
		/*
		 * if we don't have enough free bytes in this space then we need
		 * to alloc a new chunk.
		 */
3097
		if (!data_sinfo->full && alloc_chunk) {
J
Josef Bacik 已提交
3098
			u64 alloc_target;
J
Josef Bacik 已提交
3099

3100
			data_sinfo->force_alloc = CHUNK_ALLOC_FORCE;
J
Josef Bacik 已提交
3101
			spin_unlock(&data_sinfo->lock);
C
Chris Mason 已提交
3102
alloc:
J
Josef Bacik 已提交
3103
			alloc_target = btrfs_get_alloc_profile(root, 1);
3104
			trans = btrfs_join_transaction(root);
3105 3106
			if (IS_ERR(trans))
				return PTR_ERR(trans);
J
Josef Bacik 已提交
3107

J
Josef Bacik 已提交
3108 3109
			ret = do_chunk_alloc(trans, root->fs_info->extent_root,
					     bytes + 2 * 1024 * 1024,
3110 3111
					     alloc_target,
					     CHUNK_ALLOC_NO_FORCE);
J
Josef Bacik 已提交
3112
			btrfs_end_transaction(trans, root);
3113 3114 3115 3116 3117 3118
			if (ret < 0) {
				if (ret != -ENOSPC)
					return ret;
				else
					goto commit_trans;
			}
J
Josef Bacik 已提交
3119

C
Chris Mason 已提交
3120 3121 3122 3123
			if (!data_sinfo) {
				btrfs_set_inode_space_info(root, inode);
				data_sinfo = BTRFS_I(inode)->space_info;
			}
J
Josef Bacik 已提交
3124 3125
			goto again;
		}
3126 3127 3128 3129 3130 3131 3132

		/*
		 * If we have less pinned bytes than we want to allocate then
		 * don't bother committing the transaction, it won't help us.
		 */
		if (data_sinfo->bytes_pinned < bytes)
			committed = 1;
J
Josef Bacik 已提交
3133 3134
		spin_unlock(&data_sinfo->lock);

3135
		/* commit the current transaction and try again */
3136
commit_trans:
J
Josef Bacik 已提交
3137 3138
		if (!committed &&
		    !atomic_read(&root->fs_info->open_ioctl_trans)) {
3139
			committed = 1;
3140
			trans = btrfs_join_transaction(root);
3141 3142
			if (IS_ERR(trans))
				return PTR_ERR(trans);
3143 3144 3145 3146 3147
			ret = btrfs_commit_transaction(trans, root);
			if (ret)
				return ret;
			goto again;
		}
J
Josef Bacik 已提交
3148

J
Josef Bacik 已提交
3149 3150 3151 3152 3153
		return -ENOSPC;
	}
	data_sinfo->bytes_may_use += bytes;
	spin_unlock(&data_sinfo->lock);

J
Josef Bacik 已提交
3154 3155
	return 0;
}
J
Josef Bacik 已提交
3156 3157

/*
3158
 * Called if we need to clear a data reservation for this inode.
J
Josef Bacik 已提交
3159
 */
3160
void btrfs_free_reserved_data_space(struct inode *inode, u64 bytes)
3161
{
3162
	struct btrfs_root *root = BTRFS_I(inode)->root;
J
Josef Bacik 已提交
3163
	struct btrfs_space_info *data_sinfo;
3164

J
Josef Bacik 已提交
3165 3166
	/* make sure bytes are sectorsize aligned */
	bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
3167

J
Josef Bacik 已提交
3168 3169 3170 3171
	data_sinfo = BTRFS_I(inode)->space_info;
	spin_lock(&data_sinfo->lock);
	data_sinfo->bytes_may_use -= bytes;
	spin_unlock(&data_sinfo->lock);
3172 3173
}

3174
static void force_metadata_allocation(struct btrfs_fs_info *info)
3175
{
3176 3177
	struct list_head *head = &info->space_info;
	struct btrfs_space_info *found;
3178

3179 3180 3181
	rcu_read_lock();
	list_for_each_entry_rcu(found, head, list) {
		if (found->flags & BTRFS_BLOCK_GROUP_METADATA)
3182
			found->force_alloc = CHUNK_ALLOC_FORCE;
3183
	}
3184
	rcu_read_unlock();
3185 3186
}

3187
static int should_alloc_chunk(struct btrfs_root *root,
3188 3189
			      struct btrfs_space_info *sinfo, u64 alloc_bytes,
			      int force)
3190
{
3191
	struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
3192
	u64 num_bytes = sinfo->total_bytes - sinfo->bytes_readonly;
3193
	u64 num_allocated = sinfo->bytes_used + sinfo->bytes_reserved;
3194
	u64 thresh;
3195

3196 3197 3198
	if (force == CHUNK_ALLOC_FORCE)
		return 1;

3199 3200 3201 3202 3203 3204 3205
	/*
	 * We need to take into account the global rsv because for all intents
	 * and purposes it's used space.  Don't worry about locking the
	 * global_rsv, it doesn't change except when the transaction commits.
	 */
	num_allocated += global_rsv->size;

3206 3207 3208 3209 3210 3211 3212 3213 3214 3215 3216 3217 3218 3219 3220 3221 3222 3223 3224 3225 3226 3227
	/*
	 * in limited mode, we want to have some free space up to
	 * about 1% of the FS size.
	 */
	if (force == CHUNK_ALLOC_LIMITED) {
		thresh = btrfs_super_total_bytes(&root->fs_info->super_copy);
		thresh = max_t(u64, 64 * 1024 * 1024,
			       div_factor_fine(thresh, 1));

		if (num_bytes - num_allocated < thresh)
			return 1;
	}

	/*
	 * we have two similar checks here, one based on percentage
	 * and once based on a hard number of 256MB.  The idea
	 * is that if we have a good amount of free
	 * room, don't allocate a chunk.  A good mount is
	 * less than 80% utilized of the chunks we have allocated,
	 * or more than 256MB free
	 */
	if (num_allocated + alloc_bytes + 256 * 1024 * 1024 < num_bytes)
3228
		return 0;
3229

3230
	if (num_allocated + alloc_bytes < div_factor(num_bytes, 8))
3231
		return 0;
3232

3233
	thresh = btrfs_super_total_bytes(&root->fs_info->super_copy);
3234 3235

	/* 256MB or 5% of the FS */
3236 3237 3238
	thresh = max_t(u64, 256 * 1024 * 1024, div_factor_fine(thresh, 5));

	if (num_bytes > thresh && sinfo->bytes_used < div_factor(num_bytes, 3))
3239
		return 0;
3240
	return 1;
3241 3242
}

3243 3244
static int do_chunk_alloc(struct btrfs_trans_handle *trans,
			  struct btrfs_root *extent_root, u64 alloc_bytes,
C
Chris Mason 已提交
3245
			  u64 flags, int force)
J
Josef Bacik 已提交
3246
{
3247
	struct btrfs_space_info *space_info;
3248
	struct btrfs_fs_info *fs_info = extent_root->fs_info;
3249
	int wait_for_alloc = 0;
J
Josef Bacik 已提交
3250 3251
	int ret = 0;

Y
Yan Zheng 已提交
3252
	flags = btrfs_reduce_alloc_profile(extent_root, flags);
3253

3254
	space_info = __find_space_info(extent_root->fs_info, flags);
3255 3256 3257 3258
	if (!space_info) {
		ret = update_space_info(extent_root->fs_info, flags,
					0, 0, &space_info);
		BUG_ON(ret);
J
Josef Bacik 已提交
3259
	}
3260
	BUG_ON(!space_info);
J
Josef Bacik 已提交
3261

3262
again:
3263
	spin_lock(&space_info->lock);
J
Josef Bacik 已提交
3264
	if (space_info->force_alloc)
3265
		force = space_info->force_alloc;
3266 3267
	if (space_info->full) {
		spin_unlock(&space_info->lock);
3268
		return 0;
J
Josef Bacik 已提交
3269 3270
	}

3271
	if (!should_alloc_chunk(extent_root, space_info, alloc_bytes, force)) {
3272
		spin_unlock(&space_info->lock);
3273 3274 3275 3276 3277
		return 0;
	} else if (space_info->chunk_alloc) {
		wait_for_alloc = 1;
	} else {
		space_info->chunk_alloc = 1;
J
Josef Bacik 已提交
3278
	}
3279

3280
	spin_unlock(&space_info->lock);
J
Josef Bacik 已提交
3281

3282 3283 3284 3285 3286 3287 3288 3289 3290 3291 3292 3293 3294 3295
	mutex_lock(&fs_info->chunk_mutex);

	/*
	 * The chunk_mutex is held throughout the entirety of a chunk
	 * allocation, so once we've acquired the chunk_mutex we know that the
	 * other guy is done and we need to recheck and see if we should
	 * allocate.
	 */
	if (wait_for_alloc) {
		mutex_unlock(&fs_info->chunk_mutex);
		wait_for_alloc = 0;
		goto again;
	}

3296 3297 3298 3299 3300 3301 3302
	/*
	 * If we have mixed data/metadata chunks we want to make sure we keep
	 * allocating mixed chunks instead of individual chunks.
	 */
	if (btrfs_mixed_space_info(space_info))
		flags |= (BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA);

3303 3304 3305 3306 3307
	/*
	 * if we're doing a data chunk, go ahead and make sure that
	 * we keep a reasonable number of metadata chunks allocated in the
	 * FS as well.
	 */
J
Josef Bacik 已提交
3308
	if (flags & BTRFS_BLOCK_GROUP_DATA && fs_info->metadata_ratio) {
3309 3310 3311 3312
		fs_info->data_chunk_allocations++;
		if (!(fs_info->data_chunk_allocations %
		      fs_info->metadata_ratio))
			force_metadata_allocation(fs_info);
J
Josef Bacik 已提交
3313 3314
	}

Y
Yan Zheng 已提交
3315
	ret = btrfs_alloc_chunk(trans, extent_root, flags);
3316 3317 3318
	if (ret < 0 && ret != -ENOSPC)
		goto out;

J
Josef Bacik 已提交
3319 3320
	spin_lock(&space_info->lock);
	if (ret)
3321
		space_info->full = 1;
3322 3323
	else
		ret = 1;
3324

3325
	space_info->force_alloc = CHUNK_ALLOC_NO_FORCE;
3326
	space_info->chunk_alloc = 0;
J
Josef Bacik 已提交
3327
	spin_unlock(&space_info->lock);
3328
out:
Y
Yan Zheng 已提交
3329
	mutex_unlock(&extent_root->fs_info->chunk_mutex);
J
Josef Bacik 已提交
3330
	return ret;
3331
}
J
Josef Bacik 已提交
3332 3333

/*
3334
 * shrink metadata reservation for delalloc
J
Josef Bacik 已提交
3335
 */
3336
static int shrink_delalloc(struct btrfs_trans_handle *trans,
3337 3338
			   struct btrfs_root *root, u64 to_reclaim,
			   bool wait_ordered)
3339
{
3340
	struct btrfs_block_rsv *block_rsv;
J
Josef Bacik 已提交
3341
	struct btrfs_space_info *space_info;
3342 3343 3344
	u64 reserved;
	u64 max_reclaim;
	u64 reclaimed = 0;
3345
	long time_left;
3346
	int nr_pages = (2 * 1024 * 1024) >> PAGE_CACHE_SHIFT;
3347
	int loops = 0;
3348
	unsigned long progress;
3349

3350
	block_rsv = &root->fs_info->delalloc_block_rsv;
J
Josef Bacik 已提交
3351
	space_info = block_rsv->space_info;
3352 3353

	smp_mb();
3354
	reserved = space_info->bytes_may_use;
3355
	progress = space_info->reservation_progress;
3356 3357 3358

	if (reserved == 0)
		return 0;
3359

3360 3361 3362 3363 3364 3365 3366 3367
	smp_mb();
	if (root->fs_info->delalloc_bytes == 0) {
		if (trans)
			return 0;
		btrfs_wait_ordered_extents(root, 0, 0);
		return 0;
	}

3368 3369
	max_reclaim = min(reserved, to_reclaim);

3370
	while (loops < 1024) {
3371 3372 3373 3374 3375
		/* have the flusher threads jump in and do some IO */
		smp_mb();
		nr_pages = min_t(unsigned long, nr_pages,
		       root->fs_info->delalloc_bytes >> PAGE_CACHE_SHIFT);
		writeback_inodes_sb_nr_if_idle(root->fs_info->sb, nr_pages);
3376

J
Josef Bacik 已提交
3377
		spin_lock(&space_info->lock);
3378 3379 3380
		if (reserved > space_info->bytes_may_use)
			reclaimed += reserved - space_info->bytes_may_use;
		reserved = space_info->bytes_may_use;
J
Josef Bacik 已提交
3381
		spin_unlock(&space_info->lock);
3382

3383 3384
		loops++;

3385 3386 3387 3388 3389
		if (reserved == 0 || reclaimed >= max_reclaim)
			break;

		if (trans && trans->transaction->blocked)
			return -EAGAIN;
3390

3391 3392 3393 3394
		if (wait_ordered && !trans) {
			btrfs_wait_ordered_extents(root, 0, 0);
		} else {
			time_left = schedule_timeout_interruptible(1);
3395

3396 3397 3398 3399
			/* We were interrupted, exit */
			if (time_left)
				break;
		}
3400

3401 3402 3403 3404 3405 3406 3407 3408 3409 3410 3411
		/* we've kicked the IO a few times, if anything has been freed,
		 * exit.  There is no sense in looping here for a long time
		 * when we really need to commit the transaction, or there are
		 * just too many writers without enough free space
		 */

		if (loops > 3) {
			smp_mb();
			if (progress != space_info->reservation_progress)
				break;
		}
3412

3413
	}
3414

3415 3416 3417
	return reclaimed >= to_reclaim;
}

3418 3419 3420 3421 3422 3423
/**
 * reserve_metadata_bytes - try to reserve bytes from the block_rsv's space
 * @root - the root we're allocating for
 * @block_rsv - the block_rsv we're allocating for
 * @orig_bytes - the number of bytes we want
 * @flush - wether or not we can flush to make our reservation
3424
 * @check - wether this is just to check if we have enough space or not
3425
 *
3426 3427 3428 3429 3430 3431
 * This will reserve orgi_bytes number of bytes from the space info associated
 * with the block_rsv.  If there is not enough space it will make an attempt to
 * flush out space to make room.  It will do this by flushing delalloc if
 * possible or committing the transaction.  If flush is 0 then no attempts to
 * regain reservations will be made and this will fail if there is not enough
 * space already.
3432
 */
3433
static int reserve_metadata_bytes(struct btrfs_root *root,
3434
				  struct btrfs_block_rsv *block_rsv,
3435
				  u64 orig_bytes, int flush, int check)
J
Josef Bacik 已提交
3436
{
3437
	struct btrfs_space_info *space_info = block_rsv->space_info;
3438
	struct btrfs_trans_handle *trans;
3439
	u64 used;
3440 3441 3442
	u64 num_bytes = orig_bytes;
	int retries = 0;
	int ret = 0;
3443
	bool committed = false;
3444
	bool flushing = false;
3445
	bool wait_ordered = false;
3446 3447

	trans = (struct btrfs_trans_handle *)current->journal_info;
3448
again:
3449
	ret = 0;
3450
	spin_lock(&space_info->lock);
3451 3452 3453 3454 3455 3456 3457 3458 3459 3460 3461 3462 3463 3464 3465 3466 3467 3468 3469 3470 3471 3472 3473 3474
	/*
	 * We only want to wait if somebody other than us is flushing and we are
	 * actually alloed to flush.
	 */
	while (flush && !flushing && space_info->flush) {
		spin_unlock(&space_info->lock);
		/*
		 * If we have a trans handle we can't wait because the flusher
		 * may have to commit the transaction, which would mean we would
		 * deadlock since we are waiting for the flusher to finish, but
		 * hold the current transaction open.
		 */
		if (trans)
			return -EAGAIN;
		ret = wait_event_interruptible(space_info->wait,
					       !space_info->flush);
		/* Must have been interrupted, return */
		if (ret)
			return -EINTR;

		spin_lock(&space_info->lock);
	}

	ret = -ENOSPC;
3475 3476 3477
	used = space_info->bytes_used + space_info->bytes_reserved +
		space_info->bytes_pinned + space_info->bytes_readonly +
		space_info->bytes_may_use;
J
Josef Bacik 已提交
3478

3479 3480 3481 3482 3483 3484 3485
	/*
	 * The idea here is that we've not already over-reserved the block group
	 * then we can go ahead and save our reservation first and then start
	 * flushing if we need to.  Otherwise if we've already overcommitted
	 * lets start flushing stuff first and then come back and try to make
	 * our reservation.
	 */
3486 3487
	if (used <= space_info->total_bytes) {
		if (used + orig_bytes <= space_info->total_bytes) {
3488
			space_info->bytes_may_use += orig_bytes;
3489 3490 3491 3492 3493 3494 3495 3496 3497 3498 3499 3500 3501 3502 3503
			ret = 0;
		} else {
			/*
			 * Ok set num_bytes to orig_bytes since we aren't
			 * overocmmitted, this way we only try and reclaim what
			 * we need.
			 */
			num_bytes = orig_bytes;
		}
	} else {
		/*
		 * Ok we're over committed, set num_bytes to the overcommitted
		 * amount plus the amount of bytes that we need for this
		 * reservation.
		 */
3504
		wait_ordered = true;
3505
		num_bytes = used - space_info->total_bytes +
3506 3507
			(orig_bytes * (retries + 1));
	}
J
Josef Bacik 已提交
3508

3509 3510 3511 3512 3513 3514 3515 3516 3517 3518 3519 3520 3521 3522 3523 3524 3525 3526 3527 3528 3529 3530 3531 3532 3533 3534 3535
	if (ret && !check) {
		u64 profile = btrfs_get_alloc_profile(root, 0);
		u64 avail;

		spin_lock(&root->fs_info->free_chunk_lock);
		avail = root->fs_info->free_chunk_space;

		/*
		 * If we have dup, raid1 or raid10 then only half of the free
		 * space is actually useable.
		 */
		if (profile & (BTRFS_BLOCK_GROUP_DUP |
			       BTRFS_BLOCK_GROUP_RAID1 |
			       BTRFS_BLOCK_GROUP_RAID10))
			avail >>= 1;

		/*
		 * If we aren't flushing don't let us overcommit too much, say
		 * 1/8th of the space.  If we can flush, let it overcommit up to
		 * 1/2 of the space.
		 */
		if (flush)
			avail >>= 3;
		else
			avail >>= 1;
		 spin_unlock(&root->fs_info->free_chunk_lock);

3536
		if (used + num_bytes < space_info->total_bytes + avail) {
3537 3538
			space_info->bytes_may_use += orig_bytes;
			ret = 0;
3539 3540
		} else {
			wait_ordered = true;
3541 3542 3543
		}
	}

3544 3545 3546 3547 3548
	/*
	 * Couldn't make our reservation, save our place so while we're trying
	 * to reclaim space we can actually use it instead of somebody else
	 * stealing it from us.
	 */
3549 3550 3551
	if (ret && flush) {
		flushing = true;
		space_info->flush = 1;
3552
	}
J
Josef Bacik 已提交
3553

3554
	spin_unlock(&space_info->lock);
J
Josef Bacik 已提交
3555

3556
	if (!ret || !flush)
3557
		goto out;
3558

3559 3560 3561 3562
	/*
	 * We do synchronous shrinking since we don't actually unreserve
	 * metadata until after the IO is completed.
	 */
3563
	ret = shrink_delalloc(trans, root, num_bytes, wait_ordered);
3564
	if (ret < 0)
3565
		goto out;
3566

3567 3568
	ret = 0;

3569 3570 3571 3572 3573 3574
	/*
	 * So if we were overcommitted it's possible that somebody else flushed
	 * out enough space and we simply didn't have enough space to reclaim,
	 * so go back around and try again.
	 */
	if (retries < 2) {
3575
		wait_ordered = true;
3576 3577 3578
		retries++;
		goto again;
	}
3579

3580
	ret = -EAGAIN;
3581
	if (trans)
3582
		goto out;
3583

3584
	ret = -ENOSPC;
3585 3586 3587
	if (committed)
		goto out;

3588
	trans = btrfs_join_transaction(root);
3589 3590 3591
	if (IS_ERR(trans))
		goto out;
	ret = btrfs_commit_transaction(trans, root);
3592 3593 3594
	if (!ret) {
		trans = NULL;
		committed = true;
3595
		goto again;
3596
	}
3597 3598

out:
3599
	if (flushing) {
3600
		spin_lock(&space_info->lock);
3601 3602
		space_info->flush = 0;
		wake_up_all(&space_info->wait);
3603
		spin_unlock(&space_info->lock);
3604 3605 3606 3607 3608 3609 3610
	}
	return ret;
}

static struct btrfs_block_rsv *get_block_rsv(struct btrfs_trans_handle *trans,
					     struct btrfs_root *root)
{
3611 3612 3613
	struct btrfs_block_rsv *block_rsv = NULL;

	if (root->ref_cows || root == root->fs_info->csum_root)
3614
		block_rsv = trans->block_rsv;
3615 3616

	if (!block_rsv)
3617 3618 3619 3620 3621 3622 3623 3624 3625 3626 3627 3628 3629 3630 3631 3632 3633 3634 3635 3636 3637 3638 3639 3640 3641 3642 3643 3644 3645 3646 3647 3648 3649 3650 3651
		block_rsv = root->block_rsv;

	if (!block_rsv)
		block_rsv = &root->fs_info->empty_block_rsv;

	return block_rsv;
}

static int block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv,
			       u64 num_bytes)
{
	int ret = -ENOSPC;
	spin_lock(&block_rsv->lock);
	if (block_rsv->reserved >= num_bytes) {
		block_rsv->reserved -= num_bytes;
		if (block_rsv->reserved < block_rsv->size)
			block_rsv->full = 0;
		ret = 0;
	}
	spin_unlock(&block_rsv->lock);
	return ret;
}

static void block_rsv_add_bytes(struct btrfs_block_rsv *block_rsv,
				u64 num_bytes, int update_size)
{
	spin_lock(&block_rsv->lock);
	block_rsv->reserved += num_bytes;
	if (update_size)
		block_rsv->size += num_bytes;
	else if (block_rsv->reserved >= block_rsv->size)
		block_rsv->full = 1;
	spin_unlock(&block_rsv->lock);
}

3652 3653
static void block_rsv_release_bytes(struct btrfs_block_rsv *block_rsv,
				    struct btrfs_block_rsv *dest, u64 num_bytes)
3654 3655 3656 3657 3658 3659 3660 3661 3662 3663 3664 3665 3666 3667 3668 3669 3670 3671
{
	struct btrfs_space_info *space_info = block_rsv->space_info;

	spin_lock(&block_rsv->lock);
	if (num_bytes == (u64)-1)
		num_bytes = block_rsv->size;
	block_rsv->size -= num_bytes;
	if (block_rsv->reserved >= block_rsv->size) {
		num_bytes = block_rsv->reserved - block_rsv->size;
		block_rsv->reserved = block_rsv->size;
		block_rsv->full = 1;
	} else {
		num_bytes = 0;
	}
	spin_unlock(&block_rsv->lock);

	if (num_bytes > 0) {
		if (dest) {
3672 3673 3674 3675 3676 3677 3678 3679 3680 3681 3682 3683 3684 3685
			spin_lock(&dest->lock);
			if (!dest->full) {
				u64 bytes_to_add;

				bytes_to_add = dest->size - dest->reserved;
				bytes_to_add = min(num_bytes, bytes_to_add);
				dest->reserved += bytes_to_add;
				if (dest->reserved >= dest->size)
					dest->full = 1;
				num_bytes -= bytes_to_add;
			}
			spin_unlock(&dest->lock);
		}
		if (num_bytes) {
3686
			spin_lock(&space_info->lock);
3687
			space_info->bytes_may_use -= num_bytes;
3688
			space_info->reservation_progress++;
3689
			spin_unlock(&space_info->lock);
3690
		}
J
Josef Bacik 已提交
3691
	}
3692
}
3693

3694 3695 3696 3697
static int block_rsv_migrate_bytes(struct btrfs_block_rsv *src,
				   struct btrfs_block_rsv *dst, u64 num_bytes)
{
	int ret;
J
Josef Bacik 已提交
3698

3699 3700 3701
	ret = block_rsv_use_bytes(src, num_bytes);
	if (ret)
		return ret;
J
Josef Bacik 已提交
3702

3703
	block_rsv_add_bytes(dst, num_bytes, 1);
J
Josef Bacik 已提交
3704 3705 3706
	return 0;
}

3707
void btrfs_init_block_rsv(struct btrfs_block_rsv *rsv)
J
Josef Bacik 已提交
3708
{
3709 3710 3711 3712 3713 3714 3715 3716
	memset(rsv, 0, sizeof(*rsv));
	spin_lock_init(&rsv->lock);
}

struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_root *root)
{
	struct btrfs_block_rsv *block_rsv;
	struct btrfs_fs_info *fs_info = root->fs_info;
J
Josef Bacik 已提交
3717

3718 3719 3720
	block_rsv = kmalloc(sizeof(*block_rsv), GFP_NOFS);
	if (!block_rsv)
		return NULL;
J
Josef Bacik 已提交
3721

3722 3723 3724 3725 3726
	btrfs_init_block_rsv(block_rsv);
	block_rsv->space_info = __find_space_info(fs_info,
						  BTRFS_BLOCK_GROUP_METADATA);
	return block_rsv;
}
J
Josef Bacik 已提交
3727

3728 3729 3730
void btrfs_free_block_rsv(struct btrfs_root *root,
			  struct btrfs_block_rsv *rsv)
{
3731 3732
	btrfs_block_rsv_release(root, rsv, (u64)-1);
	kfree(rsv);
J
Josef Bacik 已提交
3733 3734
}

3735
int btrfs_block_rsv_add(struct btrfs_root *root,
3736
			struct btrfs_block_rsv *block_rsv,
3737
			u64 num_bytes)
3738 3739
{
	int ret;
J
Josef Bacik 已提交
3740

3741 3742
	if (num_bytes == 0)
		return 0;
3743

3744
	ret = reserve_metadata_bytes(root, block_rsv, num_bytes, 1, 0);
3745 3746 3747 3748
	if (!ret) {
		block_rsv_add_bytes(block_rsv, num_bytes, 1);
		return 0;
	}
J
Josef Bacik 已提交
3749

3750 3751
	return ret;
}
J
Josef Bacik 已提交
3752

3753
int btrfs_block_rsv_check(struct btrfs_root *root,
3754
			  struct btrfs_block_rsv *block_rsv,
3755
			  u64 min_reserved, int min_factor, int flush)
3756 3757 3758
{
	u64 num_bytes = 0;
	int ret = -ENOSPC;
J
Josef Bacik 已提交
3759

3760 3761
	if (!block_rsv)
		return 0;
J
Josef Bacik 已提交
3762

3763 3764 3765 3766 3767
	spin_lock(&block_rsv->lock);
	if (min_factor > 0)
		num_bytes = div_factor(block_rsv->size, min_factor);
	if (min_reserved > num_bytes)
		num_bytes = min_reserved;
J
Josef Bacik 已提交
3768

3769
	if (block_rsv->reserved >= num_bytes)
3770
		ret = 0;
3771
	else
3772 3773
		num_bytes -= block_rsv->reserved;
	spin_unlock(&block_rsv->lock);
3774

3775 3776 3777
	if (!ret)
		return 0;

3778
	ret = reserve_metadata_bytes(root, block_rsv, num_bytes, flush, !flush);
3779 3780 3781
	if (!ret) {
		block_rsv_add_bytes(block_rsv, num_bytes, 0);
		return 0;
3782
	}
J
Josef Bacik 已提交
3783

3784
	return ret;
3785 3786 3787 3788 3789 3790 3791 3792 3793 3794 3795 3796 3797 3798 3799 3800 3801 3802
}

int btrfs_block_rsv_migrate(struct btrfs_block_rsv *src_rsv,
			    struct btrfs_block_rsv *dst_rsv,
			    u64 num_bytes)
{
	return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
}

void btrfs_block_rsv_release(struct btrfs_root *root,
			     struct btrfs_block_rsv *block_rsv,
			     u64 num_bytes)
{
	struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
	if (global_rsv->full || global_rsv == block_rsv ||
	    block_rsv->space_info != global_rsv->space_info)
		global_rsv = NULL;
	block_rsv_release_bytes(block_rsv, global_rsv, num_bytes);
J
Josef Bacik 已提交
3803 3804 3805
}

/*
3806 3807 3808
 * helper to calculate size of global block reservation.
 * the desired value is sum of space used by extent tree,
 * checksum tree and root tree
J
Josef Bacik 已提交
3809
 */
3810
static u64 calc_global_metadata_size(struct btrfs_fs_info *fs_info)
J
Josef Bacik 已提交
3811
{
3812 3813 3814 3815 3816
	struct btrfs_space_info *sinfo;
	u64 num_bytes;
	u64 meta_used;
	u64 data_used;
	int csum_size = btrfs_super_csum_size(&fs_info->super_copy);
J
Josef Bacik 已提交
3817

3818 3819 3820 3821
	sinfo = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_DATA);
	spin_lock(&sinfo->lock);
	data_used = sinfo->bytes_used;
	spin_unlock(&sinfo->lock);
C
Chris Mason 已提交
3822

3823 3824
	sinfo = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
	spin_lock(&sinfo->lock);
3825 3826
	if (sinfo->flags & BTRFS_BLOCK_GROUP_DATA)
		data_used = 0;
3827 3828
	meta_used = sinfo->bytes_used;
	spin_unlock(&sinfo->lock);
3829

3830 3831 3832
	num_bytes = (data_used >> fs_info->sb->s_blocksize_bits) *
		    csum_size * 2;
	num_bytes += div64_u64(data_used + meta_used, 50);
3833

3834 3835
	if (num_bytes * 3 > meta_used)
		num_bytes = div64_u64(meta_used, 3);
3836

3837 3838
	return ALIGN(num_bytes, fs_info->extent_root->leafsize << 10);
}
J
Josef Bacik 已提交
3839

3840 3841 3842 3843 3844
static void update_global_block_rsv(struct btrfs_fs_info *fs_info)
{
	struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
	struct btrfs_space_info *sinfo = block_rsv->space_info;
	u64 num_bytes;
J
Josef Bacik 已提交
3845

3846
	num_bytes = calc_global_metadata_size(fs_info);
C
Chris Mason 已提交
3847

3848 3849
	spin_lock(&block_rsv->lock);
	spin_lock(&sinfo->lock);
3850

3851
	block_rsv->size = num_bytes;
3852

3853
	num_bytes = sinfo->bytes_used + sinfo->bytes_pinned +
3854 3855
		    sinfo->bytes_reserved + sinfo->bytes_readonly +
		    sinfo->bytes_may_use;
3856 3857 3858 3859

	if (sinfo->total_bytes > num_bytes) {
		num_bytes = sinfo->total_bytes - num_bytes;
		block_rsv->reserved += num_bytes;
3860
		sinfo->bytes_may_use += num_bytes;
J
Josef Bacik 已提交
3861 3862
	}

3863 3864
	if (block_rsv->reserved >= block_rsv->size) {
		num_bytes = block_rsv->reserved - block_rsv->size;
3865
		sinfo->bytes_may_use -= num_bytes;
3866
		sinfo->reservation_progress++;
3867 3868 3869
		block_rsv->reserved = block_rsv->size;
		block_rsv->full = 1;
	}
3870

3871 3872
	spin_unlock(&sinfo->lock);
	spin_unlock(&block_rsv->lock);
J
Josef Bacik 已提交
3873 3874
}

3875
static void init_global_block_rsv(struct btrfs_fs_info *fs_info)
J
Josef Bacik 已提交
3876
{
3877
	struct btrfs_space_info *space_info;
J
Josef Bacik 已提交
3878

3879 3880
	space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
	fs_info->chunk_block_rsv.space_info = space_info;
J
Josef Bacik 已提交
3881

3882
	space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
3883 3884
	fs_info->global_block_rsv.space_info = space_info;
	fs_info->delalloc_block_rsv.space_info = space_info;
3885 3886 3887
	fs_info->trans_block_rsv.space_info = space_info;
	fs_info->empty_block_rsv.space_info = space_info;

3888 3889 3890 3891
	fs_info->extent_root->block_rsv = &fs_info->global_block_rsv;
	fs_info->csum_root->block_rsv = &fs_info->global_block_rsv;
	fs_info->dev_root->block_rsv = &fs_info->global_block_rsv;
	fs_info->tree_root->block_rsv = &fs_info->global_block_rsv;
3892
	fs_info->chunk_root->block_rsv = &fs_info->chunk_block_rsv;
3893 3894

	update_global_block_rsv(fs_info);
J
Josef Bacik 已提交
3895 3896
}

3897
static void release_global_block_rsv(struct btrfs_fs_info *fs_info)
J
Josef Bacik 已提交
3898
{
3899 3900 3901 3902 3903 3904 3905
	block_rsv_release_bytes(&fs_info->global_block_rsv, NULL, (u64)-1);
	WARN_ON(fs_info->delalloc_block_rsv.size > 0);
	WARN_ON(fs_info->delalloc_block_rsv.reserved > 0);
	WARN_ON(fs_info->trans_block_rsv.size > 0);
	WARN_ON(fs_info->trans_block_rsv.reserved > 0);
	WARN_ON(fs_info->chunk_block_rsv.size > 0);
	WARN_ON(fs_info->chunk_block_rsv.reserved > 0);
3906
}
J
Josef Bacik 已提交
3907

3908 3909
void btrfs_trans_release_metadata(struct btrfs_trans_handle *trans,
				  struct btrfs_root *root)
J
Josef Bacik 已提交
3910
{
3911 3912
	struct btrfs_block_rsv *block_rsv;

3913 3914
	if (!trans->bytes_reserved)
		return;
J
Josef Bacik 已提交
3915

3916 3917
	block_rsv = &root->fs_info->trans_block_rsv;
	btrfs_block_rsv_release(root, block_rsv, trans->bytes_reserved);
3918 3919
	trans->bytes_reserved = 0;
}
J
Josef Bacik 已提交
3920

3921 3922 3923 3924 3925 3926 3927 3928
int btrfs_orphan_reserve_metadata(struct btrfs_trans_handle *trans,
				  struct inode *inode)
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_block_rsv *src_rsv = get_block_rsv(trans, root);
	struct btrfs_block_rsv *dst_rsv = root->orphan_block_rsv;

	/*
3929 3930 3931
	 * We need to hold space in order to delete our orphan item once we've
	 * added it, so this takes the reservation so we can release it later
	 * when we are truly done with the orphan item.
3932
	 */
C
Chris Mason 已提交
3933
	u64 num_bytes = btrfs_calc_trans_metadata_size(root, 1);
3934
	return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
J
Josef Bacik 已提交
3935 3936
}

3937
void btrfs_orphan_release_metadata(struct inode *inode)
3938
{
3939
	struct btrfs_root *root = BTRFS_I(inode)->root;
C
Chris Mason 已提交
3940
	u64 num_bytes = btrfs_calc_trans_metadata_size(root, 1);
3941 3942
	btrfs_block_rsv_release(root, root->orphan_block_rsv, num_bytes);
}
3943

3944 3945 3946 3947 3948 3949 3950 3951 3952 3953
int btrfs_snap_reserve_metadata(struct btrfs_trans_handle *trans,
				struct btrfs_pending_snapshot *pending)
{
	struct btrfs_root *root = pending->root;
	struct btrfs_block_rsv *src_rsv = get_block_rsv(trans, root);
	struct btrfs_block_rsv *dst_rsv = &pending->block_rsv;
	/*
	 * two for root back/forward refs, two for directory entries
	 * and one for root of the snapshot.
	 */
3954
	u64 num_bytes = btrfs_calc_trans_metadata_size(root, 5);
3955 3956
	dst_rsv->space_info = src_rsv->space_info;
	return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
3957 3958
}

3959 3960 3961 3962 3963 3964 3965 3966 3967
/**
 * drop_outstanding_extent - drop an outstanding extent
 * @inode: the inode we're dropping the extent for
 *
 * This is called when we are freeing up an outstanding extent, either called
 * after an error or after an extent is written.  This will return the number of
 * reserved extents that need to be freed.  This must be called with
 * BTRFS_I(inode)->lock held.
 */
3968 3969 3970 3971 3972 3973 3974 3975 3976 3977 3978 3979 3980
static unsigned drop_outstanding_extent(struct inode *inode)
{
	unsigned dropped_extents = 0;

	BUG_ON(!BTRFS_I(inode)->outstanding_extents);
	BTRFS_I(inode)->outstanding_extents--;

	/*
	 * If we have more or the same amount of outsanding extents than we have
	 * reserved then we need to leave the reserved extents count alone.
	 */
	if (BTRFS_I(inode)->outstanding_extents >=
	    BTRFS_I(inode)->reserved_extents)
3981
		return 0;
3982 3983 3984 3985 3986 3987 3988

	dropped_extents = BTRFS_I(inode)->reserved_extents -
		BTRFS_I(inode)->outstanding_extents;
	BTRFS_I(inode)->reserved_extents -= dropped_extents;
	return dropped_extents;
}

3989 3990 3991 3992 3993 3994 3995 3996 3997 3998 3999 4000 4001 4002 4003 4004 4005 4006 4007 4008
/**
 * calc_csum_metadata_size - return the amount of metada space that must be
 *	reserved/free'd for the given bytes.
 * @inode: the inode we're manipulating
 * @num_bytes: the number of bytes in question
 * @reserve: 1 if we are reserving space, 0 if we are freeing space
 *
 * This adjusts the number of csum_bytes in the inode and then returns the
 * correct amount of metadata that must either be reserved or freed.  We
 * calculate how many checksums we can fit into one leaf and then divide the
 * number of bytes that will need to be checksumed by this value to figure out
 * how many checksums will be required.  If we are adding bytes then the number
 * may go up and we will return the number of additional bytes that must be
 * reserved.  If it is going down we will return the number of bytes that must
 * be freed.
 *
 * This must be called with BTRFS_I(inode)->lock held.
 */
static u64 calc_csum_metadata_size(struct inode *inode, u64 num_bytes,
				   int reserve)
4009
{
4010 4011 4012 4013 4014 4015 4016 4017 4018 4019 4020 4021 4022 4023 4024 4025 4026 4027 4028 4029 4030 4031 4032 4033 4034 4035 4036 4037 4038 4039 4040 4041 4042 4043 4044
	struct btrfs_root *root = BTRFS_I(inode)->root;
	u64 csum_size;
	int num_csums_per_leaf;
	int num_csums;
	int old_csums;

	if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM &&
	    BTRFS_I(inode)->csum_bytes == 0)
		return 0;

	old_csums = (int)div64_u64(BTRFS_I(inode)->csum_bytes, root->sectorsize);
	if (reserve)
		BTRFS_I(inode)->csum_bytes += num_bytes;
	else
		BTRFS_I(inode)->csum_bytes -= num_bytes;
	csum_size = BTRFS_LEAF_DATA_SIZE(root) - sizeof(struct btrfs_item);
	num_csums_per_leaf = (int)div64_u64(csum_size,
					    sizeof(struct btrfs_csum_item) +
					    sizeof(struct btrfs_disk_key));
	num_csums = (int)div64_u64(BTRFS_I(inode)->csum_bytes, root->sectorsize);
	num_csums = num_csums + num_csums_per_leaf - 1;
	num_csums = num_csums / num_csums_per_leaf;

	old_csums = old_csums + num_csums_per_leaf - 1;
	old_csums = old_csums / num_csums_per_leaf;

	/* No change, no need to reserve more */
	if (old_csums == num_csums)
		return 0;

	if (reserve)
		return btrfs_calc_trans_metadata_size(root,
						      num_csums - old_csums);

	return btrfs_calc_trans_metadata_size(root, old_csums - num_csums);
4045
}
Y
Yan Zheng 已提交
4046

4047 4048 4049 4050
int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes)
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_block_rsv *block_rsv = &root->fs_info->delalloc_block_rsv;
4051 4052
	u64 to_reserve = 0;
	unsigned nr_extents = 0;
4053
	int flush = 1;
4054
	int ret;
4055

4056 4057 4058 4059
	if (btrfs_is_free_space_inode(root, inode))
		flush = 0;

	if (flush && btrfs_transaction_in_commit(root->fs_info))
4060
		schedule_timeout(1);
4061

4062
	num_bytes = ALIGN(num_bytes, root->sectorsize);
4063

4064 4065 4066 4067 4068 4069 4070 4071
	spin_lock(&BTRFS_I(inode)->lock);
	BTRFS_I(inode)->outstanding_extents++;

	if (BTRFS_I(inode)->outstanding_extents >
	    BTRFS_I(inode)->reserved_extents) {
		nr_extents = BTRFS_I(inode)->outstanding_extents -
			BTRFS_I(inode)->reserved_extents;
		BTRFS_I(inode)->reserved_extents += nr_extents;
4072

4073
		to_reserve = btrfs_calc_trans_metadata_size(root, nr_extents);
4074
	}
4075
	to_reserve += calc_csum_metadata_size(inode, num_bytes, 1);
4076
	spin_unlock(&BTRFS_I(inode)->lock);
4077

4078
	ret = reserve_metadata_bytes(root, block_rsv, to_reserve, flush, 0);
4079
	if (ret) {
4080
		u64 to_free = 0;
4081
		unsigned dropped;
4082

4083
		spin_lock(&BTRFS_I(inode)->lock);
4084
		dropped = drop_outstanding_extent(inode);
4085
		to_free = calc_csum_metadata_size(inode, num_bytes, 0);
4086
		spin_unlock(&BTRFS_I(inode)->lock);
4087 4088 4089 4090 4091 4092 4093 4094 4095 4096 4097
		to_free += btrfs_calc_trans_metadata_size(root, dropped);

		/*
		 * Somebody could have come in and twiddled with the
		 * reservation, so if we have to free more than we would have
		 * reserved from this reservation go ahead and release those
		 * bytes.
		 */
		to_free -= to_reserve;
		if (to_free)
			btrfs_block_rsv_release(root, block_rsv, to_free);
4098
		return ret;
4099
	}
4100

4101 4102 4103 4104 4105
	block_rsv_add_bytes(block_rsv, to_reserve, 1);

	return 0;
}

4106 4107 4108 4109 4110 4111 4112 4113 4114
/**
 * btrfs_delalloc_release_metadata - release a metadata reservation for an inode
 * @inode: the inode to release the reservation for
 * @num_bytes: the number of bytes we're releasing
 *
 * This will release the metadata reservation for an inode.  This can be called
 * once we complete IO for a given set of bytes to release their metadata
 * reservations.
 */
4115 4116 4117
void btrfs_delalloc_release_metadata(struct inode *inode, u64 num_bytes)
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
4118 4119
	u64 to_free = 0;
	unsigned dropped;
4120 4121

	num_bytes = ALIGN(num_bytes, root->sectorsize);
4122
	spin_lock(&BTRFS_I(inode)->lock);
4123
	dropped = drop_outstanding_extent(inode);
4124

4125 4126
	to_free = calc_csum_metadata_size(inode, num_bytes, 0);
	spin_unlock(&BTRFS_I(inode)->lock);
4127 4128
	if (dropped > 0)
		to_free += btrfs_calc_trans_metadata_size(root, dropped);
4129 4130 4131 4132 4133

	btrfs_block_rsv_release(root, &root->fs_info->delalloc_block_rsv,
				to_free);
}

4134 4135 4136 4137 4138 4139 4140 4141 4142 4143 4144 4145 4146 4147 4148
/**
 * btrfs_delalloc_reserve_space - reserve data and metadata space for delalloc
 * @inode: inode we're writing to
 * @num_bytes: the number of bytes we want to allocate
 *
 * This will do the following things
 *
 * o reserve space in the data space info for num_bytes
 * o reserve space in the metadata space info based on number of outstanding
 *   extents and how much csums will be needed
 * o add to the inodes ->delalloc_bytes
 * o add it to the fs_info's delalloc inodes list.
 *
 * This will return 0 for success and -ENOSPC if there is no space left.
 */
4149 4150 4151 4152 4153
int btrfs_delalloc_reserve_space(struct inode *inode, u64 num_bytes)
{
	int ret;

	ret = btrfs_check_data_free_space(inode, num_bytes);
C
Chris Mason 已提交
4154
	if (ret)
4155 4156 4157 4158 4159 4160 4161 4162 4163 4164 4165
		return ret;

	ret = btrfs_delalloc_reserve_metadata(inode, num_bytes);
	if (ret) {
		btrfs_free_reserved_data_space(inode, num_bytes);
		return ret;
	}

	return 0;
}

4166 4167 4168 4169 4170 4171 4172 4173 4174 4175 4176 4177 4178
/**
 * btrfs_delalloc_release_space - release data and metadata space for delalloc
 * @inode: inode we're releasing space for
 * @num_bytes: the number of bytes we want to free up
 *
 * This must be matched with a call to btrfs_delalloc_reserve_space.  This is
 * called in the case that we don't need the metadata AND data reservations
 * anymore.  So if there is an error or we insert an inline extent.
 *
 * This function will release the metadata space that was not used and will
 * decrement ->delalloc_bytes and remove it from the fs_info delalloc_inodes
 * list if there are no delalloc bytes left.
 */
4179 4180 4181 4182
void btrfs_delalloc_release_space(struct inode *inode, u64 num_bytes)
{
	btrfs_delalloc_release_metadata(inode, num_bytes);
	btrfs_free_reserved_data_space(inode, num_bytes);
4183 4184
}

C
Chris Mason 已提交
4185 4186
static int update_block_group(struct btrfs_trans_handle *trans,
			      struct btrfs_root *root,
4187
			      u64 bytenr, u64 num_bytes, int alloc)
C
Chris Mason 已提交
4188
{
4189
	struct btrfs_block_group_cache *cache = NULL;
C
Chris Mason 已提交
4190
	struct btrfs_fs_info *info = root->fs_info;
4191
	u64 total = num_bytes;
C
Chris Mason 已提交
4192
	u64 old_val;
4193
	u64 byte_in_group;
4194
	int factor;
C
Chris Mason 已提交
4195

4196 4197 4198 4199 4200 4201 4202 4203 4204 4205
	/* block accounting for super block */
	spin_lock(&info->delalloc_lock);
	old_val = btrfs_super_bytes_used(&info->super_copy);
	if (alloc)
		old_val += num_bytes;
	else
		old_val -= num_bytes;
	btrfs_set_super_bytes_used(&info->super_copy, old_val);
	spin_unlock(&info->delalloc_lock);

C
Chris Mason 已提交
4206
	while (total) {
4207
		cache = btrfs_lookup_block_group(info, bytenr);
4208
		if (!cache)
C
Chris Mason 已提交
4209
			return -1;
4210 4211 4212 4213 4214 4215
		if (cache->flags & (BTRFS_BLOCK_GROUP_DUP |
				    BTRFS_BLOCK_GROUP_RAID1 |
				    BTRFS_BLOCK_GROUP_RAID10))
			factor = 2;
		else
			factor = 1;
4216 4217 4218 4219 4220 4221 4222
		/*
		 * If this block group has free space cache written out, we
		 * need to make sure to load it if we are removing space.  This
		 * is because we need the unpinning stage to actually add the
		 * space back to the block group, otherwise we will leak space.
		 */
		if (!alloc && cache->cached == BTRFS_CACHE_NO)
4223
			cache_block_group(cache, trans, NULL, 1);
4224

4225 4226
		byte_in_group = bytenr - cache->key.objectid;
		WARN_ON(byte_in_group > cache->key.offset);
C
Chris Mason 已提交
4227

4228
		spin_lock(&cache->space_info->lock);
4229
		spin_lock(&cache->lock);
4230

4231
		if (btrfs_test_opt(root, SPACE_CACHE) &&
4232 4233 4234
		    cache->disk_cache_state < BTRFS_DC_CLEAR)
			cache->disk_cache_state = BTRFS_DC_CLEAR;

J
Josef Bacik 已提交
4235
		cache->dirty = 1;
C
Chris Mason 已提交
4236
		old_val = btrfs_block_group_used(&cache->item);
4237
		num_bytes = min(total, cache->key.offset - byte_in_group);
C
Chris Mason 已提交
4238
		if (alloc) {
4239
			old_val += num_bytes;
4240 4241 4242
			btrfs_set_block_group_used(&cache->item, old_val);
			cache->reserved -= num_bytes;
			cache->space_info->bytes_reserved -= num_bytes;
4243 4244
			cache->space_info->bytes_used += num_bytes;
			cache->space_info->disk_used += num_bytes * factor;
4245
			spin_unlock(&cache->lock);
4246
			spin_unlock(&cache->space_info->lock);
C
Chris Mason 已提交
4247
		} else {
4248
			old_val -= num_bytes;
4249
			btrfs_set_block_group_used(&cache->item, old_val);
4250 4251
			cache->pinned += num_bytes;
			cache->space_info->bytes_pinned += num_bytes;
4252
			cache->space_info->bytes_used -= num_bytes;
4253
			cache->space_info->disk_used -= num_bytes * factor;
4254
			spin_unlock(&cache->lock);
4255
			spin_unlock(&cache->space_info->lock);
4256

4257 4258 4259
			set_extent_dirty(info->pinned_extents,
					 bytenr, bytenr + num_bytes - 1,
					 GFP_NOFS | __GFP_NOFAIL);
C
Chris Mason 已提交
4260
		}
4261
		btrfs_put_block_group(cache);
4262 4263
		total -= num_bytes;
		bytenr += num_bytes;
C
Chris Mason 已提交
4264 4265 4266
	}
	return 0;
}
4267

4268 4269
static u64 first_logical_byte(struct btrfs_root *root, u64 search_start)
{
J
Josef Bacik 已提交
4270
	struct btrfs_block_group_cache *cache;
4271
	u64 bytenr;
J
Josef Bacik 已提交
4272 4273 4274

	cache = btrfs_lookup_first_block_group(root->fs_info, search_start);
	if (!cache)
4275
		return 0;
J
Josef Bacik 已提交
4276

4277
	bytenr = cache->key.objectid;
4278
	btrfs_put_block_group(cache);
4279 4280

	return bytenr;
4281 4282
}

4283 4284 4285
static int pin_down_extent(struct btrfs_root *root,
			   struct btrfs_block_group_cache *cache,
			   u64 bytenr, u64 num_bytes, int reserved)
4286
{
4287 4288 4289 4290 4291 4292 4293 4294 4295 4296
	spin_lock(&cache->space_info->lock);
	spin_lock(&cache->lock);
	cache->pinned += num_bytes;
	cache->space_info->bytes_pinned += num_bytes;
	if (reserved) {
		cache->reserved -= num_bytes;
		cache->space_info->bytes_reserved -= num_bytes;
	}
	spin_unlock(&cache->lock);
	spin_unlock(&cache->space_info->lock);
J
Josef Bacik 已提交
4297

4298 4299 4300 4301
	set_extent_dirty(root->fs_info->pinned_extents, bytenr,
			 bytenr + num_bytes - 1, GFP_NOFS | __GFP_NOFAIL);
	return 0;
}
J
Josef Bacik 已提交
4302

4303 4304 4305 4306 4307 4308 4309
/*
 * this function must be called within transaction
 */
int btrfs_pin_extent(struct btrfs_root *root,
		     u64 bytenr, u64 num_bytes, int reserved)
{
	struct btrfs_block_group_cache *cache;
J
Josef Bacik 已提交
4310

4311 4312 4313 4314 4315 4316
	cache = btrfs_lookup_block_group(root->fs_info, bytenr);
	BUG_ON(!cache);

	pin_down_extent(root, cache, bytenr, num_bytes, reserved);

	btrfs_put_block_group(cache);
4317 4318 4319
	return 0;
}

4320 4321 4322 4323 4324 4325 4326 4327 4328 4329 4330 4331 4332 4333 4334 4335 4336 4337 4338 4339 4340
/**
 * btrfs_update_reserved_bytes - update the block_group and space info counters
 * @cache:	The cache we are manipulating
 * @num_bytes:	The number of bytes in question
 * @reserve:	One of the reservation enums
 *
 * This is called by the allocator when it reserves space, or by somebody who is
 * freeing space that was never actually used on disk.  For example if you
 * reserve some space for a new leaf in transaction A and before transaction A
 * commits you free that leaf, you call this with reserve set to 0 in order to
 * clear the reservation.
 *
 * Metadata reservations should be called with RESERVE_ALLOC so we do the proper
 * ENOSPC accounting.  For data we handle the reservation through clearing the
 * delalloc bits in the io_tree.  We have to do this since we could end up
 * allocating less disk space for the amount of data we have reserved in the
 * case of compression.
 *
 * If this is a reservation and the block group has become read only we cannot
 * make the reservation and return -EAGAIN, otherwise this function always
 * succeeds.
4341
 */
4342 4343
static int btrfs_update_reserved_bytes(struct btrfs_block_group_cache *cache,
				       u64 num_bytes, int reserve)
4344
{
4345
	struct btrfs_space_info *space_info = cache->space_info;
4346
	int ret = 0;
4347 4348 4349
	spin_lock(&space_info->lock);
	spin_lock(&cache->lock);
	if (reserve != RESERVE_FREE) {
4350 4351 4352
		if (cache->ro) {
			ret = -EAGAIN;
		} else {
4353 4354 4355 4356 4357 4358
			cache->reserved += num_bytes;
			space_info->bytes_reserved += num_bytes;
			if (reserve == RESERVE_ALLOC) {
				BUG_ON(space_info->bytes_may_use < num_bytes);
				space_info->bytes_may_use -= num_bytes;
			}
4359
		}
4360 4361 4362 4363 4364 4365
	} else {
		if (cache->ro)
			space_info->bytes_readonly += num_bytes;
		cache->reserved -= num_bytes;
		space_info->bytes_reserved -= num_bytes;
		space_info->reservation_progress++;
4366
	}
4367 4368
	spin_unlock(&cache->lock);
	spin_unlock(&space_info->lock);
4369
	return ret;
4370
}
C
Chris Mason 已提交
4371

4372 4373
int btrfs_prepare_extent_commit(struct btrfs_trans_handle *trans,
				struct btrfs_root *root)
4374 4375
{
	struct btrfs_fs_info *fs_info = root->fs_info;
4376 4377 4378
	struct btrfs_caching_control *next;
	struct btrfs_caching_control *caching_ctl;
	struct btrfs_block_group_cache *cache;
4379

4380
	down_write(&fs_info->extent_commit_sem);
4381

4382 4383 4384 4385 4386 4387 4388
	list_for_each_entry_safe(caching_ctl, next,
				 &fs_info->caching_block_groups, list) {
		cache = caching_ctl->block_group;
		if (block_group_cache_done(cache)) {
			cache->last_byte_to_unpin = (u64)-1;
			list_del_init(&caching_ctl->list);
			put_caching_control(caching_ctl);
4389
		} else {
4390
			cache->last_byte_to_unpin = caching_ctl->progress;
4391 4392
		}
	}
4393 4394 4395 4396 4397 4398 4399

	if (fs_info->pinned_extents == &fs_info->freed_extents[0])
		fs_info->pinned_extents = &fs_info->freed_extents[1];
	else
		fs_info->pinned_extents = &fs_info->freed_extents[0];

	up_write(&fs_info->extent_commit_sem);
4400 4401

	update_global_block_rsv(fs_info);
4402 4403 4404
	return 0;
}

4405
static int unpin_extent_range(struct btrfs_root *root, u64 start, u64 end)
C
Chris Mason 已提交
4406
{
4407 4408 4409
	struct btrfs_fs_info *fs_info = root->fs_info;
	struct btrfs_block_group_cache *cache = NULL;
	u64 len;
C
Chris Mason 已提交
4410

4411 4412 4413 4414 4415 4416 4417 4418 4419 4420 4421 4422 4423 4424 4425 4426 4427
	while (start <= end) {
		if (!cache ||
		    start >= cache->key.objectid + cache->key.offset) {
			if (cache)
				btrfs_put_block_group(cache);
			cache = btrfs_lookup_block_group(fs_info, start);
			BUG_ON(!cache);
		}

		len = cache->key.objectid + cache->key.offset - start;
		len = min(len, end + 1 - start);

		if (start < cache->last_byte_to_unpin) {
			len = min(len, cache->last_byte_to_unpin - start);
			btrfs_add_free_space(cache, start, len);
		}

4428 4429
		start += len;

4430 4431 4432 4433
		spin_lock(&cache->space_info->lock);
		spin_lock(&cache->lock);
		cache->pinned -= len;
		cache->space_info->bytes_pinned -= len;
4434
		if (cache->ro)
4435
			cache->space_info->bytes_readonly += len;
4436 4437
		spin_unlock(&cache->lock);
		spin_unlock(&cache->space_info->lock);
C
Chris Mason 已提交
4438
	}
4439 4440 4441

	if (cache)
		btrfs_put_block_group(cache);
C
Chris Mason 已提交
4442 4443 4444 4445
	return 0;
}

int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
4446
			       struct btrfs_root *root)
4447
{
4448 4449
	struct btrfs_fs_info *fs_info = root->fs_info;
	struct extent_io_tree *unpin;
4450 4451
	u64 start;
	u64 end;
4452 4453
	int ret;

4454 4455 4456 4457 4458
	if (fs_info->pinned_extents == &fs_info->freed_extents[0])
		unpin = &fs_info->freed_extents[1];
	else
		unpin = &fs_info->freed_extents[0];

C
Chris Mason 已提交
4459
	while (1) {
4460 4461 4462
		ret = find_first_extent_bit(unpin, 0, &start, &end,
					    EXTENT_DIRTY);
		if (ret)
4463
			break;
4464

4465 4466 4467
		if (btrfs_test_opt(root, DISCARD))
			ret = btrfs_discard_extent(root, start,
						   end + 1 - start, NULL);
4468

4469
		clear_extent_dirty(unpin, start, end, GFP_NOFS);
4470
		unpin_extent_range(root, start, end);
4471
		cond_resched();
4472
	}
J
Josef Bacik 已提交
4473

C
Chris Mason 已提交
4474 4475 4476
	return 0;
}

4477 4478 4479 4480 4481 4482
static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
				struct btrfs_root *root,
				u64 bytenr, u64 num_bytes, u64 parent,
				u64 root_objectid, u64 owner_objectid,
				u64 owner_offset, int refs_to_drop,
				struct btrfs_delayed_extent_op *extent_op)
4483
{
C
Chris Mason 已提交
4484
	struct btrfs_key key;
4485
	struct btrfs_path *path;
4486 4487
	struct btrfs_fs_info *info = root->fs_info;
	struct btrfs_root *extent_root = info->extent_root;
4488
	struct extent_buffer *leaf;
4489 4490
	struct btrfs_extent_item *ei;
	struct btrfs_extent_inline_ref *iref;
4491
	int ret;
4492
	int is_data;
4493 4494 4495
	int extent_slot = 0;
	int found_extent = 0;
	int num_to_del = 1;
4496 4497
	u32 item_size;
	u64 refs;
C
Chris Mason 已提交
4498

4499
	path = btrfs_alloc_path();
4500 4501
	if (!path)
		return -ENOMEM;
4502

4503
	path->reada = 1;
4504
	path->leave_spinning = 1;
4505 4506 4507 4508 4509 4510 4511 4512

	is_data = owner_objectid >= BTRFS_FIRST_FREE_OBJECTID;
	BUG_ON(!is_data && refs_to_drop != 1);

	ret = lookup_extent_backref(trans, extent_root, path, &iref,
				    bytenr, num_bytes, parent,
				    root_objectid, owner_objectid,
				    owner_offset);
4513
	if (ret == 0) {
4514
		extent_slot = path->slots[0];
4515 4516
		while (extent_slot >= 0) {
			btrfs_item_key_to_cpu(path->nodes[0], &key,
4517
					      extent_slot);
4518
			if (key.objectid != bytenr)
4519
				break;
4520 4521
			if (key.type == BTRFS_EXTENT_ITEM_KEY &&
			    key.offset == num_bytes) {
4522 4523 4524 4525 4526
				found_extent = 1;
				break;
			}
			if (path->slots[0] - extent_slot > 5)
				break;
4527
			extent_slot--;
4528
		}
4529 4530 4531 4532 4533
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
		item_size = btrfs_item_size_nr(path->nodes[0], extent_slot);
		if (found_extent && item_size < sizeof(*ei))
			found_extent = 0;
#endif
Z
Zheng Yan 已提交
4534
		if (!found_extent) {
4535
			BUG_ON(iref);
4536
			ret = remove_extent_backref(trans, extent_root, path,
4537 4538
						    NULL, refs_to_drop,
						    is_data);
Z
Zheng Yan 已提交
4539
			BUG_ON(ret);
4540
			btrfs_release_path(path);
4541
			path->leave_spinning = 1;
4542 4543 4544 4545 4546

			key.objectid = bytenr;
			key.type = BTRFS_EXTENT_ITEM_KEY;
			key.offset = num_bytes;

Z
Zheng Yan 已提交
4547 4548
			ret = btrfs_search_slot(trans, extent_root,
						&key, path, -1, 1);
4549 4550
			if (ret) {
				printk(KERN_ERR "umm, got %d back from search"
C
Chris Mason 已提交
4551 4552
				       ", was looking for %llu\n", ret,
				       (unsigned long long)bytenr);
4553 4554 4555
				if (ret > 0)
					btrfs_print_leaf(extent_root,
							 path->nodes[0]);
4556
			}
Z
Zheng Yan 已提交
4557 4558 4559
			BUG_ON(ret);
			extent_slot = path->slots[0];
		}
4560 4561 4562
	} else {
		btrfs_print_leaf(extent_root, path->nodes[0]);
		WARN_ON(1);
C
Chris Mason 已提交
4563
		printk(KERN_ERR "btrfs unable to find ref byte nr %llu "
4564
		       "parent %llu root %llu  owner %llu offset %llu\n",
C
Chris Mason 已提交
4565
		       (unsigned long long)bytenr,
4566
		       (unsigned long long)parent,
C
Chris Mason 已提交
4567
		       (unsigned long long)root_objectid,
4568 4569
		       (unsigned long long)owner_objectid,
		       (unsigned long long)owner_offset);
4570
	}
4571 4572

	leaf = path->nodes[0];
4573 4574 4575 4576 4577 4578 4579 4580
	item_size = btrfs_item_size_nr(leaf, extent_slot);
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
	if (item_size < sizeof(*ei)) {
		BUG_ON(found_extent || extent_slot != path->slots[0]);
		ret = convert_extent_item_v0(trans, extent_root, path,
					     owner_objectid, 0);
		BUG_ON(ret < 0);

4581
		btrfs_release_path(path);
4582 4583 4584 4585 4586 4587 4588 4589 4590 4591 4592 4593 4594 4595 4596 4597 4598 4599 4600 4601 4602
		path->leave_spinning = 1;

		key.objectid = bytenr;
		key.type = BTRFS_EXTENT_ITEM_KEY;
		key.offset = num_bytes;

		ret = btrfs_search_slot(trans, extent_root, &key, path,
					-1, 1);
		if (ret) {
			printk(KERN_ERR "umm, got %d back from search"
			       ", was looking for %llu\n", ret,
			       (unsigned long long)bytenr);
			btrfs_print_leaf(extent_root, path->nodes[0]);
		}
		BUG_ON(ret);
		extent_slot = path->slots[0];
		leaf = path->nodes[0];
		item_size = btrfs_item_size_nr(leaf, extent_slot);
	}
#endif
	BUG_ON(item_size < sizeof(*ei));
4603
	ei = btrfs_item_ptr(leaf, extent_slot,
C
Chris Mason 已提交
4604
			    struct btrfs_extent_item);
4605 4606 4607 4608 4609 4610
	if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID) {
		struct btrfs_tree_block_info *bi;
		BUG_ON(item_size < sizeof(*ei) + sizeof(*bi));
		bi = (struct btrfs_tree_block_info *)(ei + 1);
		WARN_ON(owner_objectid != btrfs_tree_block_level(leaf, bi));
	}
4611

4612
	refs = btrfs_extent_refs(leaf, ei);
4613 4614
	BUG_ON(refs < refs_to_drop);
	refs -= refs_to_drop;
4615

4616 4617 4618 4619 4620 4621
	if (refs > 0) {
		if (extent_op)
			__run_delayed_extent_op(extent_op, leaf, ei);
		/*
		 * In the case of inline back ref, reference count will
		 * be updated by remove_extent_backref
4622
		 */
4623 4624 4625 4626 4627 4628 4629 4630 4631 4632
		if (iref) {
			BUG_ON(!found_extent);
		} else {
			btrfs_set_extent_refs(leaf, ei, refs);
			btrfs_mark_buffer_dirty(leaf);
		}
		if (found_extent) {
			ret = remove_extent_backref(trans, extent_root, path,
						    iref, refs_to_drop,
						    is_data);
4633 4634
			BUG_ON(ret);
		}
4635 4636 4637 4638 4639 4640 4641 4642 4643 4644 4645
	} else {
		if (found_extent) {
			BUG_ON(is_data && refs_to_drop !=
			       extent_data_ref_count(root, path, iref));
			if (iref) {
				BUG_ON(path->slots[0] != extent_slot);
			} else {
				BUG_ON(path->slots[0] != extent_slot + 1);
				path->slots[0] = extent_slot;
				num_to_del = 2;
			}
C
Chris Mason 已提交
4646
		}
4647

4648 4649
		ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
				      num_to_del);
Z
Zheng Yan 已提交
4650
		BUG_ON(ret);
4651
		btrfs_release_path(path);
4652

4653
		if (is_data) {
4654 4655
			ret = btrfs_del_csums(trans, root, bytenr, num_bytes);
			BUG_ON(ret);
4656 4657 4658 4659
		} else {
			invalidate_mapping_pages(info->btree_inode->i_mapping,
			     bytenr >> PAGE_CACHE_SHIFT,
			     (bytenr + num_bytes - 1) >> PAGE_CACHE_SHIFT);
4660 4661
		}

4662
		ret = update_block_group(trans, root, bytenr, num_bytes, 0);
4663
		BUG_ON(ret);
4664
	}
4665
	btrfs_free_path(path);
4666 4667 4668
	return ret;
}

4669
/*
4670
 * when we free an block, it is possible (and likely) that we free the last
4671 4672 4673 4674 4675 4676 4677 4678 4679 4680 4681
 * delayed ref for that extent as well.  This searches the delayed ref tree for
 * a given extent, and if there are no other delayed refs to be processed, it
 * removes it from the tree.
 */
static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans,
				      struct btrfs_root *root, u64 bytenr)
{
	struct btrfs_delayed_ref_head *head;
	struct btrfs_delayed_ref_root *delayed_refs;
	struct btrfs_delayed_ref_node *ref;
	struct rb_node *node;
4682
	int ret = 0;
4683 4684 4685 4686 4687 4688 4689 4690 4691 4692 4693 4694 4695 4696 4697 4698 4699

	delayed_refs = &trans->transaction->delayed_refs;
	spin_lock(&delayed_refs->lock);
	head = btrfs_find_delayed_ref_head(trans, bytenr);
	if (!head)
		goto out;

	node = rb_prev(&head->node.rb_node);
	if (!node)
		goto out;

	ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);

	/* there are still entries for this ref, we can't drop it */
	if (ref->bytenr == bytenr)
		goto out;

4700 4701 4702 4703 4704 4705 4706
	if (head->extent_op) {
		if (!head->must_insert_reserved)
			goto out;
		kfree(head->extent_op);
		head->extent_op = NULL;
	}

4707 4708 4709 4710 4711 4712 4713 4714 4715 4716 4717 4718 4719
	/*
	 * waiting for the lock here would deadlock.  If someone else has it
	 * locked they are already in the process of dropping it anyway
	 */
	if (!mutex_trylock(&head->mutex))
		goto out;

	/*
	 * at this point we have a head with no other entries.  Go
	 * ahead and process it.
	 */
	head->node.in_tree = 0;
	rb_erase(&head->node.rb_node, &delayed_refs->root);
4720

4721 4722 4723 4724 4725 4726
	delayed_refs->num_entries--;

	/*
	 * we don't take a ref on the node because we're removing it from the
	 * tree, so we just steal the ref the tree was holding.
	 */
4727 4728 4729 4730 4731
	delayed_refs->num_heads--;
	if (list_empty(&head->cluster))
		delayed_refs->num_heads_ready--;

	list_del_init(&head->cluster);
4732 4733
	spin_unlock(&delayed_refs->lock);

4734 4735 4736 4737 4738
	BUG_ON(head->extent_op);
	if (head->must_insert_reserved)
		ret = 1;

	mutex_unlock(&head->mutex);
4739
	btrfs_put_delayed_ref(&head->node);
4740
	return ret;
4741 4742 4743 4744 4745
out:
	spin_unlock(&delayed_refs->lock);
	return 0;
}

4746 4747 4748 4749 4750 4751 4752 4753 4754 4755 4756 4757 4758 4759 4760 4761 4762 4763 4764 4765 4766 4767 4768 4769 4770
void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
			   struct btrfs_root *root,
			   struct extent_buffer *buf,
			   u64 parent, int last_ref)
{
	struct btrfs_block_group_cache *cache = NULL;
	int ret;

	if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
		ret = btrfs_add_delayed_tree_ref(trans, buf->start, buf->len,
						parent, root->root_key.objectid,
						btrfs_header_level(buf),
						BTRFS_DROP_DELAYED_REF, NULL);
		BUG_ON(ret);
	}

	if (!last_ref)
		return;

	cache = btrfs_lookup_block_group(root->fs_info, buf->start);

	if (btrfs_header_generation(buf) == trans->transid) {
		if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
			ret = check_ref_cleanup(trans, root, buf->start);
			if (!ret)
4771
				goto out;
4772 4773 4774 4775
		}

		if (btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
			pin_down_extent(root, cache, buf->start, buf->len, 1);
4776
			goto out;
4777 4778 4779 4780 4781
		}

		WARN_ON(test_bit(EXTENT_BUFFER_DIRTY, &buf->bflags));

		btrfs_add_free_space(cache, buf->start, buf->len);
4782
		btrfs_update_reserved_bytes(cache, buf->len, RESERVE_FREE);
4783 4784
	}
out:
4785 4786 4787 4788 4789
	/*
	 * Deleting the buffer, clear the corrupt flag since it doesn't matter
	 * anymore.
	 */
	clear_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags);
4790 4791 4792
	btrfs_put_block_group(cache);
}

4793
int btrfs_free_extent(struct btrfs_trans_handle *trans,
Z
Zheng Yan 已提交
4794 4795
		      struct btrfs_root *root,
		      u64 bytenr, u64 num_bytes, u64 parent,
4796
		      u64 root_objectid, u64 owner, u64 offset)
4797 4798 4799
{
	int ret;

4800 4801 4802 4803
	/*
	 * tree log blocks never actually go into the extent allocation
	 * tree, just update pinning info and exit early.
	 */
4804 4805
	if (root_objectid == BTRFS_TREE_LOG_OBJECTID) {
		WARN_ON(owner >= BTRFS_FIRST_FREE_OBJECTID);
4806
		/* unlocks the pinned mutex */
4807
		btrfs_pin_extent(root, bytenr, num_bytes, 1);
4808
		ret = 0;
4809 4810 4811 4812
	} else if (owner < BTRFS_FIRST_FREE_OBJECTID) {
		ret = btrfs_add_delayed_tree_ref(trans, bytenr, num_bytes,
					parent, root_objectid, (int)owner,
					BTRFS_DROP_DELAYED_REF, NULL);
4813
		BUG_ON(ret);
4814 4815 4816 4817 4818
	} else {
		ret = btrfs_add_delayed_data_ref(trans, bytenr, num_bytes,
					parent, root_objectid, owner,
					offset, BTRFS_DROP_DELAYED_REF, NULL);
		BUG_ON(ret);
4819
	}
4820 4821 4822
	return ret;
}

4823 4824 4825 4826 4827 4828 4829
static u64 stripe_align(struct btrfs_root *root, u64 val)
{
	u64 mask = ((u64)root->stripesize - 1);
	u64 ret = (val + mask) & ~mask;
	return ret;
}

J
Josef Bacik 已提交
4830 4831 4832 4833 4834 4835 4836 4837 4838 4839 4840 4841 4842 4843 4844
/*
 * when we wait for progress in the block group caching, its because
 * our allocation attempt failed at least once.  So, we must sleep
 * and let some progress happen before we try again.
 *
 * This function will sleep at least once waiting for new free space to
 * show up, and then it will check the block group free space numbers
 * for our min num_bytes.  Another option is to have it go ahead
 * and look in the rbtree for a free extent of a given size, but this
 * is a good start.
 */
static noinline int
wait_block_group_cache_progress(struct btrfs_block_group_cache *cache,
				u64 num_bytes)
{
4845
	struct btrfs_caching_control *caching_ctl;
J
Josef Bacik 已提交
4846 4847
	DEFINE_WAIT(wait);

4848 4849
	caching_ctl = get_caching_control(cache);
	if (!caching_ctl)
J
Josef Bacik 已提交
4850 4851
		return 0;

4852
	wait_event(caching_ctl->wait, block_group_cache_done(cache) ||
4853
		   (cache->free_space_ctl->free_space >= num_bytes));
4854 4855 4856 4857 4858 4859 4860 4861 4862 4863 4864 4865 4866 4867 4868 4869 4870 4871

	put_caching_control(caching_ctl);
	return 0;
}

static noinline int
wait_block_group_cache_done(struct btrfs_block_group_cache *cache)
{
	struct btrfs_caching_control *caching_ctl;
	DEFINE_WAIT(wait);

	caching_ctl = get_caching_control(cache);
	if (!caching_ctl)
		return 0;

	wait_event(caching_ctl->wait, block_group_cache_done(cache));

	put_caching_control(caching_ctl);
J
Josef Bacik 已提交
4872 4873 4874
	return 0;
}

4875 4876 4877 4878 4879 4880 4881 4882 4883 4884 4885 4886 4887 4888 4889 4890
static int get_block_group_index(struct btrfs_block_group_cache *cache)
{
	int index;
	if (cache->flags & BTRFS_BLOCK_GROUP_RAID10)
		index = 0;
	else if (cache->flags & BTRFS_BLOCK_GROUP_RAID1)
		index = 1;
	else if (cache->flags & BTRFS_BLOCK_GROUP_DUP)
		index = 2;
	else if (cache->flags & BTRFS_BLOCK_GROUP_RAID0)
		index = 3;
	else
		index = 4;
	return index;
}

J
Josef Bacik 已提交
4891
enum btrfs_loop_type {
4892
	LOOP_FIND_IDEAL = 0,
J
Josef Bacik 已提交
4893 4894 4895 4896 4897 4898
	LOOP_CACHING_NOWAIT = 1,
	LOOP_CACHING_WAIT = 2,
	LOOP_ALLOC_CHUNK = 3,
	LOOP_NO_EMPTY_SIZE = 4,
};

4899 4900 4901 4902
/*
 * walks the btree of allocated extents and find a hole of a given size.
 * The key ins is changed to record the hole:
 * ins->objectid == block start
4903
 * ins->flags = BTRFS_EXTENT_ITEM_KEY
4904 4905 4906
 * ins->offset == number of blocks
 * Any available blocks before search_start are skipped.
 */
C
Chris Mason 已提交
4907
static noinline int find_free_extent(struct btrfs_trans_handle *trans,
4908 4909 4910 4911
				     struct btrfs_root *orig_root,
				     u64 num_bytes, u64 empty_size,
				     u64 search_start, u64 search_end,
				     u64 hint_byte, struct btrfs_key *ins,
4912
				     u64 data)
4913
{
4914
	int ret = 0;
C
Chris Mason 已提交
4915
	struct btrfs_root *root = orig_root->fs_info->extent_root;
4916
	struct btrfs_free_cluster *last_ptr = NULL;
4917
	struct btrfs_block_group_cache *block_group = NULL;
4918
	int empty_cluster = 2 * 1024 * 1024;
C
Chris Mason 已提交
4919
	int allowed_chunk_alloc = 0;
4920
	int done_chunk_alloc = 0;
4921
	struct btrfs_space_info *space_info;
4922 4923
	int last_ptr_loop = 0;
	int loop = 0;
4924
	int index = 0;
4925 4926
	int alloc_type = (data & BTRFS_BLOCK_GROUP_DATA) ?
		RESERVE_ALLOC_NO_ACCOUNT : RESERVE_ALLOC;
J
Josef Bacik 已提交
4927
	bool found_uncached_bg = false;
4928
	bool failed_cluster_refill = false;
4929
	bool failed_alloc = false;
4930
	bool use_cluster = true;
4931 4932
	u64 ideal_cache_percent = 0;
	u64 ideal_cache_offset = 0;
4933

4934
	WARN_ON(num_bytes < root->sectorsize);
4935
	btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
4936 4937
	ins->objectid = 0;
	ins->offset = 0;
4938

J
Josef Bacik 已提交
4939
	space_info = __find_space_info(root->fs_info, data);
4940
	if (!space_info) {
4941
		printk(KERN_ERR "No space info for %llu\n", data);
4942 4943
		return -ENOSPC;
	}
J
Josef Bacik 已提交
4944

4945 4946 4947 4948 4949 4950 4951
	/*
	 * If the space info is for both data and metadata it means we have a
	 * small filesystem and we can't use the clustering stuff.
	 */
	if (btrfs_mixed_space_info(space_info))
		use_cluster = false;

C
Chris Mason 已提交
4952 4953 4954
	if (orig_root->ref_cows || empty_size)
		allowed_chunk_alloc = 1;

4955
	if (data & BTRFS_BLOCK_GROUP_METADATA && use_cluster) {
4956
		last_ptr = &root->fs_info->meta_alloc_cluster;
4957 4958
		if (!btrfs_test_opt(root, SSD))
			empty_cluster = 64 * 1024;
4959 4960
	}

4961 4962
	if ((data & BTRFS_BLOCK_GROUP_DATA) && use_cluster &&
	    btrfs_test_opt(root, SSD)) {
4963 4964
		last_ptr = &root->fs_info->data_alloc_cluster;
	}
J
Josef Bacik 已提交
4965

4966
	if (last_ptr) {
4967 4968 4969 4970
		spin_lock(&last_ptr->lock);
		if (last_ptr->block_group)
			hint_byte = last_ptr->window_start;
		spin_unlock(&last_ptr->lock);
4971
	}
4972

4973
	search_start = max(search_start, first_logical_byte(root, 0));
4974
	search_start = max(search_start, hint_byte);
4975

J
Josef Bacik 已提交
4976
	if (!last_ptr)
4977 4978
		empty_cluster = 0;

J
Josef Bacik 已提交
4979
	if (search_start == hint_byte) {
4980
ideal_cache:
J
Josef Bacik 已提交
4981 4982
		block_group = btrfs_lookup_block_group(root->fs_info,
						       search_start);
J
Josef Bacik 已提交
4983 4984 4985
		/*
		 * we don't want to use the block group if it doesn't match our
		 * allocation bits, or if its not cached.
4986 4987 4988
		 *
		 * However if we are re-searching with an ideal block group
		 * picked out then we don't care that the block group is cached.
J
Josef Bacik 已提交
4989 4990
		 */
		if (block_group && block_group_bits(block_group, data) &&
4991 4992
		    (block_group->cached != BTRFS_CACHE_NO ||
		     search_start == ideal_cache_offset)) {
J
Josef Bacik 已提交
4993
			down_read(&space_info->groups_sem);
4994 4995 4996 4997 4998 4999 5000 5001 5002 5003
			if (list_empty(&block_group->list) ||
			    block_group->ro) {
				/*
				 * someone is removing this block group,
				 * we can't jump into the have_block_group
				 * target because our list pointers are not
				 * valid
				 */
				btrfs_put_block_group(block_group);
				up_read(&space_info->groups_sem);
5004
			} else {
5005
				index = get_block_group_index(block_group);
5006
				goto have_block_group;
5007
			}
J
Josef Bacik 已提交
5008
		} else if (block_group) {
5009
			btrfs_put_block_group(block_group);
J
Josef Bacik 已提交
5010
		}
5011
	}
J
Josef Bacik 已提交
5012
search:
5013
	down_read(&space_info->groups_sem);
5014 5015
	list_for_each_entry(block_group, &space_info->block_groups[index],
			    list) {
5016
		u64 offset;
J
Josef Bacik 已提交
5017
		int cached;
5018

5019
		btrfs_get_block_group(block_group);
J
Josef Bacik 已提交
5020
		search_start = block_group->key.objectid;
5021

5022 5023 5024 5025 5026 5027 5028 5029 5030 5031 5032 5033 5034 5035 5036 5037 5038 5039 5040
		/*
		 * this can happen if we end up cycling through all the
		 * raid types, but we want to make sure we only allocate
		 * for the proper type.
		 */
		if (!block_group_bits(block_group, data)) {
		    u64 extra = BTRFS_BLOCK_GROUP_DUP |
				BTRFS_BLOCK_GROUP_RAID1 |
				BTRFS_BLOCK_GROUP_RAID10;

			/*
			 * if they asked for extra copies and this block group
			 * doesn't provide them, bail.  This does allow us to
			 * fill raid0 from raid1.
			 */
			if ((data & extra) && !(block_group->flags & extra))
				goto loop;
		}

J
Josef Bacik 已提交
5041
have_block_group:
J
Josef Bacik 已提交
5042
		if (unlikely(block_group->cached == BTRFS_CACHE_NO)) {
5043 5044
			u64 free_percent;

5045 5046
			ret = cache_block_group(block_group, trans,
						orig_root, 1);
5047 5048 5049
			if (block_group->cached == BTRFS_CACHE_FINISHED)
				goto have_block_group;

5050 5051 5052 5053 5054 5055 5056 5057 5058 5059 5060
			free_percent = btrfs_block_group_used(&block_group->item);
			free_percent *= 100;
			free_percent = div64_u64(free_percent,
						 block_group->key.offset);
			free_percent = 100 - free_percent;
			if (free_percent > ideal_cache_percent &&
			    likely(!block_group->ro)) {
				ideal_cache_offset = block_group->key.objectid;
				ideal_cache_percent = free_percent;
			}

J
Josef Bacik 已提交
5061
			/*
5062 5063
			 * The caching workers are limited to 2 threads, so we
			 * can queue as much work as we care to.
J
Josef Bacik 已提交
5064
			 */
5065
			if (loop > LOOP_FIND_IDEAL) {
5066 5067
				ret = cache_block_group(block_group, trans,
							orig_root, 0);
J
Josef Bacik 已提交
5068
				BUG_ON(ret);
J
Josef Bacik 已提交
5069
			}
J
Josef Bacik 已提交
5070 5071
			found_uncached_bg = true;

5072 5073 5074 5075 5076
			/*
			 * If loop is set for cached only, try the next block
			 * group.
			 */
			if (loop == LOOP_FIND_IDEAL)
J
Josef Bacik 已提交
5077 5078 5079
				goto loop;
		}

5080 5081 5082 5083
		cached = block_group_cache_done(block_group);
		if (unlikely(!cached))
			found_uncached_bg = true;

5084
		if (unlikely(block_group->ro))
J
Josef Bacik 已提交
5085
			goto loop;
J
Josef Bacik 已提交
5086

C
Chris Mason 已提交
5087
		spin_lock(&block_group->free_space_ctl->tree_lock);
5088
		if (cached &&
C
Chris Mason 已提交
5089 5090 5091
		    block_group->free_space_ctl->free_space <
		    num_bytes + empty_size) {
			spin_unlock(&block_group->free_space_ctl->tree_lock);
5092 5093
			goto loop;
		}
C
Chris Mason 已提交
5094
		spin_unlock(&block_group->free_space_ctl->tree_lock);
5095

5096 5097 5098 5099 5100 5101 5102 5103 5104 5105
		/*
		 * Ok we want to try and use the cluster allocator, so lets look
		 * there, unless we are on LOOP_NO_EMPTY_SIZE, since we will
		 * have tried the cluster allocator plenty of times at this
		 * point and not have found anything, so we are likely way too
		 * fragmented for the clustering stuff to find anything, so lets
		 * just skip it and let the allocator find whatever block it can
		 * find
		 */
		if (last_ptr && loop < LOOP_NO_EMPTY_SIZE) {
5106 5107 5108 5109 5110
			/*
			 * the refill lock keeps out other
			 * people trying to start a new cluster
			 */
			spin_lock(&last_ptr->refill_lock);
5111 5112 5113 5114 5115 5116 5117
			if (last_ptr->block_group &&
			    (last_ptr->block_group->ro ||
			    !block_group_bits(last_ptr->block_group, data))) {
				offset = 0;
				goto refill_cluster;
			}

5118 5119 5120 5121 5122 5123 5124 5125 5126 5127 5128 5129 5130 5131 5132
			offset = btrfs_alloc_from_cluster(block_group, last_ptr,
						 num_bytes, search_start);
			if (offset) {
				/* we have a block, we're done */
				spin_unlock(&last_ptr->refill_lock);
				goto checks;
			}

			spin_lock(&last_ptr->lock);
			/*
			 * whoops, this cluster doesn't actually point to
			 * this block group.  Get a ref on the block
			 * group is does point to and try again
			 */
			if (!last_ptr_loop && last_ptr->block_group &&
5133 5134 5135
			    last_ptr->block_group != block_group &&
			    index <=
				 get_block_group_index(last_ptr->block_group)) {
5136 5137 5138

				btrfs_put_block_group(block_group);
				block_group = last_ptr->block_group;
5139
				btrfs_get_block_group(block_group);
5140 5141 5142 5143 5144
				spin_unlock(&last_ptr->lock);
				spin_unlock(&last_ptr->refill_lock);

				last_ptr_loop = 1;
				search_start = block_group->key.objectid;
5145 5146 5147 5148 5149 5150 5151
				/*
				 * we know this block group is properly
				 * in the list because
				 * btrfs_remove_block_group, drops the
				 * cluster before it removes the block
				 * group from the list
				 */
5152 5153 5154
				goto have_block_group;
			}
			spin_unlock(&last_ptr->lock);
5155
refill_cluster:
5156 5157 5158 5159 5160 5161 5162 5163 5164
			/*
			 * this cluster didn't work out, free it and
			 * start over
			 */
			btrfs_return_cluster_to_free_space(NULL, last_ptr);

			last_ptr_loop = 0;

			/* allocate a cluster in this block group */
5165
			ret = btrfs_find_space_cluster(trans, root,
5166 5167 5168 5169 5170 5171 5172 5173 5174 5175 5176 5177 5178 5179 5180 5181
					       block_group, last_ptr,
					       offset, num_bytes,
					       empty_cluster + empty_size);
			if (ret == 0) {
				/*
				 * now pull our allocation out of this
				 * cluster
				 */
				offset = btrfs_alloc_from_cluster(block_group,
						  last_ptr, num_bytes,
						  search_start);
				if (offset) {
					/* we found one, proceed */
					spin_unlock(&last_ptr->refill_lock);
					goto checks;
				}
5182 5183
			} else if (!cached && loop > LOOP_CACHING_NOWAIT
				   && !failed_cluster_refill) {
J
Josef Bacik 已提交
5184 5185
				spin_unlock(&last_ptr->refill_lock);

5186
				failed_cluster_refill = true;
J
Josef Bacik 已提交
5187 5188 5189
				wait_block_group_cache_progress(block_group,
				       num_bytes + empty_cluster + empty_size);
				goto have_block_group;
5190
			}
J
Josef Bacik 已提交
5191

5192 5193 5194 5195 5196 5197
			/*
			 * at this point we either didn't find a cluster
			 * or we weren't able to allocate a block from our
			 * cluster.  Free the cluster we've been trying
			 * to use, and go to the next block group
			 */
5198
			btrfs_return_cluster_to_free_space(NULL, last_ptr);
5199
			spin_unlock(&last_ptr->refill_lock);
5200
			goto loop;
5201 5202
		}

5203 5204
		offset = btrfs_find_space_for_alloc(block_group, search_start,
						    num_bytes, empty_size);
5205 5206 5207 5208 5209 5210 5211 5212 5213 5214 5215
		/*
		 * If we didn't find a chunk, and we haven't failed on this
		 * block group before, and this block group is in the middle of
		 * caching and we are ok with waiting, then go ahead and wait
		 * for progress to be made, and set failed_alloc to true.
		 *
		 * If failed_alloc is true then we've already waited on this
		 * block group once and should move on to the next block group.
		 */
		if (!offset && !failed_alloc && !cached &&
		    loop > LOOP_CACHING_NOWAIT) {
J
Josef Bacik 已提交
5216
			wait_block_group_cache_progress(block_group,
5217 5218
						num_bytes + empty_size);
			failed_alloc = true;
J
Josef Bacik 已提交
5219
			goto have_block_group;
5220 5221
		} else if (!offset) {
			goto loop;
J
Josef Bacik 已提交
5222
		}
5223
checks:
5224
		search_start = stripe_align(root, offset);
J
Josef Bacik 已提交
5225
		/* move on to the next group */
5226 5227
		if (search_start + num_bytes >= search_end) {
			btrfs_add_free_space(block_group, offset, num_bytes);
J
Josef Bacik 已提交
5228
			goto loop;
5229
		}
5230

J
Josef Bacik 已提交
5231 5232
		/* move on to the next group */
		if (search_start + num_bytes >
5233 5234
		    block_group->key.objectid + block_group->key.offset) {
			btrfs_add_free_space(block_group, offset, num_bytes);
J
Josef Bacik 已提交
5235
			goto loop;
5236
		}
5237

5238 5239
		ins->objectid = search_start;
		ins->offset = num_bytes;
J
Josef Bacik 已提交
5240

5241 5242 5243 5244
		if (offset < search_start)
			btrfs_add_free_space(block_group, offset,
					     search_start - offset);
		BUG_ON(offset > search_start);
J
Josef Bacik 已提交
5245

5246 5247
		ret = btrfs_update_reserved_bytes(block_group, num_bytes,
						  alloc_type);
5248
		if (ret == -EAGAIN) {
5249
			btrfs_add_free_space(block_group, offset, num_bytes);
J
Josef Bacik 已提交
5250
			goto loop;
J
Josef Bacik 已提交
5251
		}
5252

5253
		/* we are all good, lets return */
J
Josef Bacik 已提交
5254 5255
		ins->objectid = search_start;
		ins->offset = num_bytes;
5256

5257 5258 5259 5260
		if (offset < search_start)
			btrfs_add_free_space(block_group, offset,
					     search_start - offset);
		BUG_ON(offset > search_start);
5261
		btrfs_put_block_group(block_group);
J
Josef Bacik 已提交
5262 5263
		break;
loop:
5264
		failed_cluster_refill = false;
5265
		failed_alloc = false;
5266
		BUG_ON(index != get_block_group_index(block_group));
5267
		btrfs_put_block_group(block_group);
J
Josef Bacik 已提交
5268 5269 5270
	}
	up_read(&space_info->groups_sem);

5271 5272 5273
	if (!ins->objectid && ++index < BTRFS_NR_RAID_TYPES)
		goto search;

5274 5275 5276 5277 5278
	/* LOOP_FIND_IDEAL, only search caching/cached bg's, and don't wait for
	 *			for them to make caching progress.  Also
	 *			determine the best possible bg to cache
	 * LOOP_CACHING_NOWAIT, search partially cached block groups, kicking
	 *			caching kthreads as we move along
J
Josef Bacik 已提交
5279 5280 5281 5282
	 * LOOP_CACHING_WAIT, search everything, and wait if our bg is caching
	 * LOOP_ALLOC_CHUNK, force a chunk allocation and try again
	 * LOOP_NO_EMPTY_SIZE, set empty_size and empty_cluster to 0 and try
	 *			again
5283
	 */
5284
	if (!ins->objectid && loop < LOOP_NO_EMPTY_SIZE) {
5285
		index = 0;
5286
		if (loop == LOOP_FIND_IDEAL && found_uncached_bg) {
J
Josef Bacik 已提交
5287
			found_uncached_bg = false;
5288
			loop++;
5289
			if (!ideal_cache_percent)
J
Josef Bacik 已提交
5290
				goto search;
5291 5292 5293 5294 5295 5296 5297 5298 5299 5300 5301 5302 5303 5304 5305 5306 5307 5308 5309 5310 5311 5312 5313 5314 5315 5316 5317 5318 5319 5320 5321 5322

			/*
			 * 1 of the following 2 things have happened so far
			 *
			 * 1) We found an ideal block group for caching that
			 * is mostly full and will cache quickly, so we might
			 * as well wait for it.
			 *
			 * 2) We searched for cached only and we didn't find
			 * anything, and we didn't start any caching kthreads
			 * either, so chances are we will loop through and
			 * start a couple caching kthreads, and then come back
			 * around and just wait for them.  This will be slower
			 * because we will have 2 caching kthreads reading at
			 * the same time when we could have just started one
			 * and waited for it to get far enough to give us an
			 * allocation, so go ahead and go to the wait caching
			 * loop.
			 */
			loop = LOOP_CACHING_WAIT;
			search_start = ideal_cache_offset;
			ideal_cache_percent = 0;
			goto ideal_cache;
		} else if (loop == LOOP_FIND_IDEAL) {
			/*
			 * Didn't find a uncached bg, wait on anything we find
			 * next.
			 */
			loop = LOOP_CACHING_WAIT;
			goto search;
		}

5323
		loop++;
J
Josef Bacik 已提交
5324 5325

		if (loop == LOOP_ALLOC_CHUNK) {
5326 5327 5328 5329 5330 5331 5332 5333 5334 5335 5336 5337
		       if (allowed_chunk_alloc) {
				ret = do_chunk_alloc(trans, root, num_bytes +
						     2 * 1024 * 1024, data,
						     CHUNK_ALLOC_LIMITED);
				allowed_chunk_alloc = 0;
				if (ret == 1)
					done_chunk_alloc = 1;
			} else if (!done_chunk_alloc &&
				   space_info->force_alloc ==
				   CHUNK_ALLOC_NO_FORCE) {
				space_info->force_alloc = CHUNK_ALLOC_LIMITED;
			}
J
Josef Bacik 已提交
5338

5339 5340 5341 5342 5343 5344
		       /*
			* We didn't allocate a chunk, go ahead and drop the
			* empty size and loop again.
			*/
		       if (!done_chunk_alloc)
			       loop = LOOP_NO_EMPTY_SIZE;
J
Josef Bacik 已提交
5345 5346
		}

5347 5348 5349
		if (loop == LOOP_NO_EMPTY_SIZE) {
			empty_size = 0;
			empty_cluster = 0;
5350
		}
5351 5352

		goto search;
J
Josef Bacik 已提交
5353 5354
	} else if (!ins->objectid) {
		ret = -ENOSPC;
5355
	} else if (ins->objectid) {
5356
		ret = 0;
C
Chris Mason 已提交
5357 5358
	}

C
Chris Mason 已提交
5359
	return ret;
5360
}
5361

J
Josef Bacik 已提交
5362 5363
static void dump_space_info(struct btrfs_space_info *info, u64 bytes,
			    int dump_block_groups)
J
Josef Bacik 已提交
5364 5365
{
	struct btrfs_block_group_cache *cache;
5366
	int index = 0;
J
Josef Bacik 已提交
5367

J
Josef Bacik 已提交
5368
	spin_lock(&info->lock);
5369 5370
	printk(KERN_INFO "space_info %llu has %llu free, is %sfull\n",
	       (unsigned long long)info->flags,
C
Chris Mason 已提交
5371
	       (unsigned long long)(info->total_bytes - info->bytes_used -
J
Josef Bacik 已提交
5372
				    info->bytes_pinned - info->bytes_reserved -
5373
				    info->bytes_readonly),
C
Chris Mason 已提交
5374
	       (info->full) ? "" : "not ");
5375 5376
	printk(KERN_INFO "space_info total=%llu, used=%llu, pinned=%llu, "
	       "reserved=%llu, may_use=%llu, readonly=%llu\n",
5377
	       (unsigned long long)info->total_bytes,
5378
	       (unsigned long long)info->bytes_used,
5379
	       (unsigned long long)info->bytes_pinned,
5380
	       (unsigned long long)info->bytes_reserved,
5381
	       (unsigned long long)info->bytes_may_use,
5382
	       (unsigned long long)info->bytes_readonly);
J
Josef Bacik 已提交
5383 5384 5385 5386
	spin_unlock(&info->lock);

	if (!dump_block_groups)
		return;
J
Josef Bacik 已提交
5387

5388
	down_read(&info->groups_sem);
5389 5390
again:
	list_for_each_entry(cache, &info->block_groups[index], list) {
J
Josef Bacik 已提交
5391
		spin_lock(&cache->lock);
C
Chris Mason 已提交
5392 5393 5394 5395 5396 5397 5398
		printk(KERN_INFO "block group %llu has %llu bytes, %llu used "
		       "%llu pinned %llu reserved\n",
		       (unsigned long long)cache->key.objectid,
		       (unsigned long long)cache->key.offset,
		       (unsigned long long)btrfs_block_group_used(&cache->item),
		       (unsigned long long)cache->pinned,
		       (unsigned long long)cache->reserved);
J
Josef Bacik 已提交
5399 5400 5401
		btrfs_dump_free_space(cache, bytes);
		spin_unlock(&cache->lock);
	}
5402 5403
	if (++index < BTRFS_NR_RAID_TYPES)
		goto again;
5404
	up_read(&info->groups_sem);
J
Josef Bacik 已提交
5405
}
5406

5407 5408 5409 5410 5411 5412
int btrfs_reserve_extent(struct btrfs_trans_handle *trans,
			 struct btrfs_root *root,
			 u64 num_bytes, u64 min_alloc_size,
			 u64 empty_size, u64 hint_byte,
			 u64 search_end, struct btrfs_key *ins,
			 u64 data)
5413 5414
{
	int ret;
5415
	u64 search_start = 0;
5416

J
Josef Bacik 已提交
5417
	data = btrfs_get_alloc_profile(root, data);
5418
again:
C
Chris Mason 已提交
5419 5420 5421 5422
	/*
	 * the only place that sets empty_size is btrfs_realloc_node, which
	 * is not called recursively on allocations
	 */
J
Josef Bacik 已提交
5423
	if (empty_size || root->ref_cows)
5424
		ret = do_chunk_alloc(trans, root->fs_info->extent_root,
5425 5426
				     num_bytes + 2 * 1024 * 1024, data,
				     CHUNK_ALLOC_NO_FORCE);
5427

5428 5429
	WARN_ON(num_bytes < root->sectorsize);
	ret = find_free_extent(trans, root, num_bytes, empty_size,
5430 5431
			       search_start, search_end, hint_byte,
			       ins, data);
5432

5433 5434
	if (ret == -ENOSPC && num_bytes > min_alloc_size) {
		num_bytes = num_bytes >> 1;
J
Josef Bacik 已提交
5435
		num_bytes = num_bytes & ~(root->sectorsize - 1);
5436
		num_bytes = max(num_bytes, min_alloc_size);
C
Chris Mason 已提交
5437
		do_chunk_alloc(trans, root->fs_info->extent_root,
5438
			       num_bytes, data, CHUNK_ALLOC_FORCE);
5439 5440
		goto again;
	}
5441
	if (ret == -ENOSPC && btrfs_test_opt(root, ENOSPC_DEBUG)) {
J
Josef Bacik 已提交
5442 5443 5444
		struct btrfs_space_info *sinfo;

		sinfo = __find_space_info(root->fs_info, data);
C
Chris Mason 已提交
5445 5446 5447
		printk(KERN_ERR "btrfs allocation failed flags %llu, "
		       "wanted %llu\n", (unsigned long long)data,
		       (unsigned long long)num_bytes);
J
Josef Bacik 已提交
5448
		dump_space_info(sinfo, num_bytes, 1);
5449
	}
J
Josef Bacik 已提交
5450

5451 5452
	trace_btrfs_reserved_extent_alloc(root, ins->objectid, ins->offset);

J
Josef Bacik 已提交
5453
	return ret;
5454 5455
}

5456 5457
int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len)
{
J
Josef Bacik 已提交
5458
	struct btrfs_block_group_cache *cache;
5459
	int ret = 0;
J
Josef Bacik 已提交
5460 5461 5462

	cache = btrfs_lookup_block_group(root->fs_info, start);
	if (!cache) {
C
Chris Mason 已提交
5463 5464
		printk(KERN_ERR "Unable to find block group for %llu\n",
		       (unsigned long long)start);
J
Josef Bacik 已提交
5465 5466
		return -ENOSPC;
	}
5467

5468 5469
	if (btrfs_test_opt(root, DISCARD))
		ret = btrfs_discard_extent(root, start, len, NULL);
5470

J
Josef Bacik 已提交
5471
	btrfs_add_free_space(cache, start, len);
5472
	btrfs_update_reserved_bytes(cache, len, RESERVE_FREE);
5473
	btrfs_put_block_group(cache);
J
Josef Bacik 已提交
5474

5475 5476
	trace_btrfs_reserved_extent_free(root, start, len);

5477 5478 5479
	return ret;
}

5480 5481 5482 5483 5484
static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
				      struct btrfs_root *root,
				      u64 parent, u64 root_objectid,
				      u64 flags, u64 owner, u64 offset,
				      struct btrfs_key *ins, int ref_mod)
5485 5486
{
	int ret;
5487
	struct btrfs_fs_info *fs_info = root->fs_info;
5488
	struct btrfs_extent_item *extent_item;
5489
	struct btrfs_extent_inline_ref *iref;
5490
	struct btrfs_path *path;
5491 5492 5493
	struct extent_buffer *leaf;
	int type;
	u32 size;
5494

5495 5496 5497 5498
	if (parent > 0)
		type = BTRFS_SHARED_DATA_REF_KEY;
	else
		type = BTRFS_EXTENT_DATA_REF_KEY;
5499

5500
	size = sizeof(*extent_item) + btrfs_extent_inline_ref_size(type);
5501 5502

	path = btrfs_alloc_path();
T
Tsutomu Itoh 已提交
5503 5504
	if (!path)
		return -ENOMEM;
5505

5506
	path->leave_spinning = 1;
5507 5508
	ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
				      ins, size);
C
Chris Mason 已提交
5509
	BUG_ON(ret);
J
Josef Bacik 已提交
5510

5511 5512
	leaf = path->nodes[0];
	extent_item = btrfs_item_ptr(leaf, path->slots[0],
5513
				     struct btrfs_extent_item);
5514 5515 5516 5517 5518 5519 5520 5521 5522 5523 5524 5525 5526 5527 5528 5529 5530 5531 5532 5533
	btrfs_set_extent_refs(leaf, extent_item, ref_mod);
	btrfs_set_extent_generation(leaf, extent_item, trans->transid);
	btrfs_set_extent_flags(leaf, extent_item,
			       flags | BTRFS_EXTENT_FLAG_DATA);

	iref = (struct btrfs_extent_inline_ref *)(extent_item + 1);
	btrfs_set_extent_inline_ref_type(leaf, iref, type);
	if (parent > 0) {
		struct btrfs_shared_data_ref *ref;
		ref = (struct btrfs_shared_data_ref *)(iref + 1);
		btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
		btrfs_set_shared_data_ref_count(leaf, ref, ref_mod);
	} else {
		struct btrfs_extent_data_ref *ref;
		ref = (struct btrfs_extent_data_ref *)(&iref->offset);
		btrfs_set_extent_data_ref_root(leaf, ref, root_objectid);
		btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
		btrfs_set_extent_data_ref_offset(leaf, ref, offset);
		btrfs_set_extent_data_ref_count(leaf, ref, ref_mod);
	}
5534 5535

	btrfs_mark_buffer_dirty(path->nodes[0]);
5536
	btrfs_free_path(path);
5537

5538
	ret = update_block_group(trans, root, ins->objectid, ins->offset, 1);
5539
	if (ret) {
C
Chris Mason 已提交
5540 5541 5542
		printk(KERN_ERR "btrfs update block group failed for %llu "
		       "%llu\n", (unsigned long long)ins->objectid,
		       (unsigned long long)ins->offset);
5543 5544
		BUG();
	}
5545 5546 5547
	return ret;
}

5548 5549 5550 5551 5552
static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
				     struct btrfs_root *root,
				     u64 parent, u64 root_objectid,
				     u64 flags, struct btrfs_disk_key *key,
				     int level, struct btrfs_key *ins)
5553 5554
{
	int ret;
5555 5556 5557 5558 5559 5560 5561
	struct btrfs_fs_info *fs_info = root->fs_info;
	struct btrfs_extent_item *extent_item;
	struct btrfs_tree_block_info *block_info;
	struct btrfs_extent_inline_ref *iref;
	struct btrfs_path *path;
	struct extent_buffer *leaf;
	u32 size = sizeof(*extent_item) + sizeof(*block_info) + sizeof(*iref);
5562

5563
	path = btrfs_alloc_path();
5564 5565
	if (!path)
		return -ENOMEM;
5566

5567 5568 5569
	path->leave_spinning = 1;
	ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
				      ins, size);
5570
	BUG_ON(ret);
5571 5572 5573 5574 5575 5576 5577 5578 5579 5580 5581 5582 5583 5584 5585 5586 5587 5588 5589 5590 5591 5592 5593 5594 5595 5596 5597 5598

	leaf = path->nodes[0];
	extent_item = btrfs_item_ptr(leaf, path->slots[0],
				     struct btrfs_extent_item);
	btrfs_set_extent_refs(leaf, extent_item, 1);
	btrfs_set_extent_generation(leaf, extent_item, trans->transid);
	btrfs_set_extent_flags(leaf, extent_item,
			       flags | BTRFS_EXTENT_FLAG_TREE_BLOCK);
	block_info = (struct btrfs_tree_block_info *)(extent_item + 1);

	btrfs_set_tree_block_key(leaf, block_info, key);
	btrfs_set_tree_block_level(leaf, block_info, level);

	iref = (struct btrfs_extent_inline_ref *)(block_info + 1);
	if (parent > 0) {
		BUG_ON(!(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF));
		btrfs_set_extent_inline_ref_type(leaf, iref,
						 BTRFS_SHARED_BLOCK_REF_KEY);
		btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
	} else {
		btrfs_set_extent_inline_ref_type(leaf, iref,
						 BTRFS_TREE_BLOCK_REF_KEY);
		btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
	}

	btrfs_mark_buffer_dirty(leaf);
	btrfs_free_path(path);

5599
	ret = update_block_group(trans, root, ins->objectid, ins->offset, 1);
5600 5601 5602 5603 5604 5605 5606 5607 5608 5609 5610 5611 5612 5613 5614 5615 5616 5617 5618 5619 5620
	if (ret) {
		printk(KERN_ERR "btrfs update block group failed for %llu "
		       "%llu\n", (unsigned long long)ins->objectid,
		       (unsigned long long)ins->offset);
		BUG();
	}
	return ret;
}

int btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
				     struct btrfs_root *root,
				     u64 root_objectid, u64 owner,
				     u64 offset, struct btrfs_key *ins)
{
	int ret;

	BUG_ON(root_objectid == BTRFS_TREE_LOG_OBJECTID);

	ret = btrfs_add_delayed_data_ref(trans, ins->objectid, ins->offset,
					 0, root_objectid, owner, offset,
					 BTRFS_ADD_DELAYED_EXTENT, NULL);
5621 5622
	return ret;
}
5623 5624 5625 5626 5627 5628

/*
 * this is used by the tree logging recovery code.  It records that
 * an extent has been allocated and makes sure to clear the free
 * space cache bits as well
 */
5629 5630 5631 5632
int btrfs_alloc_logged_file_extent(struct btrfs_trans_handle *trans,
				   struct btrfs_root *root,
				   u64 root_objectid, u64 owner, u64 offset,
				   struct btrfs_key *ins)
5633 5634 5635
{
	int ret;
	struct btrfs_block_group_cache *block_group;
5636 5637 5638
	struct btrfs_caching_control *caching_ctl;
	u64 start = ins->objectid;
	u64 num_bytes = ins->offset;
5639 5640

	block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid);
5641
	cache_block_group(block_group, trans, NULL, 0);
5642
	caching_ctl = get_caching_control(block_group);
5643

5644 5645 5646 5647 5648 5649 5650 5651 5652 5653 5654 5655 5656 5657 5658 5659 5660 5661 5662 5663 5664 5665 5666 5667 5668 5669 5670 5671 5672 5673 5674
	if (!caching_ctl) {
		BUG_ON(!block_group_cache_done(block_group));
		ret = btrfs_remove_free_space(block_group, start, num_bytes);
		BUG_ON(ret);
	} else {
		mutex_lock(&caching_ctl->mutex);

		if (start >= caching_ctl->progress) {
			ret = add_excluded_extent(root, start, num_bytes);
			BUG_ON(ret);
		} else if (start + num_bytes <= caching_ctl->progress) {
			ret = btrfs_remove_free_space(block_group,
						      start, num_bytes);
			BUG_ON(ret);
		} else {
			num_bytes = caching_ctl->progress - start;
			ret = btrfs_remove_free_space(block_group,
						      start, num_bytes);
			BUG_ON(ret);

			start = caching_ctl->progress;
			num_bytes = ins->objectid + ins->offset -
				    caching_ctl->progress;
			ret = add_excluded_extent(root, start, num_bytes);
			BUG_ON(ret);
		}

		mutex_unlock(&caching_ctl->mutex);
		put_caching_control(caching_ctl);
	}

5675 5676
	ret = btrfs_update_reserved_bytes(block_group, ins->offset,
					  RESERVE_ALLOC_NO_ACCOUNT);
5677
	BUG_ON(ret);
5678
	btrfs_put_block_group(block_group);
5679 5680
	ret = alloc_reserved_file_extent(trans, root, 0, root_objectid,
					 0, owner, offset, ins, 1);
5681 5682 5683
	return ret;
}

5684 5685
struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
					    struct btrfs_root *root,
5686 5687
					    u64 bytenr, u32 blocksize,
					    int level)
5688 5689 5690 5691 5692 5693 5694
{
	struct extent_buffer *buf;

	buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
	if (!buf)
		return ERR_PTR(-ENOMEM);
	btrfs_set_header_generation(buf, trans->transid);
5695
	btrfs_set_buffer_lockdep_class(root->root_key.objectid, buf, level);
5696 5697
	btrfs_tree_lock(buf);
	clean_tree_block(trans, root, buf);
5698 5699

	btrfs_set_lock_blocking(buf);
5700
	btrfs_set_buffer_uptodate(buf);
5701

5702
	if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
5703 5704 5705 5706 5707 5708 5709 5710 5711 5712
		/*
		 * we allow two log transactions at a time, use different
		 * EXENT bit to differentiate dirty pages.
		 */
		if (root->log_transid % 2 == 0)
			set_extent_dirty(&root->dirty_log_pages, buf->start,
					buf->start + buf->len - 1, GFP_NOFS);
		else
			set_extent_new(&root->dirty_log_pages, buf->start,
					buf->start + buf->len - 1, GFP_NOFS);
5713 5714
	} else {
		set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
5715
			 buf->start + buf->len - 1, GFP_NOFS);
5716
	}
5717
	trans->blocks_used++;
5718
	/* this returns a buffer locked for blocking */
5719 5720 5721
	return buf;
}

5722 5723 5724 5725 5726
static struct btrfs_block_rsv *
use_block_rsv(struct btrfs_trans_handle *trans,
	      struct btrfs_root *root, u32 blocksize)
{
	struct btrfs_block_rsv *block_rsv;
5727
	struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
5728 5729 5730 5731 5732
	int ret;

	block_rsv = get_block_rsv(trans, root);

	if (block_rsv->size == 0) {
5733
		ret = reserve_metadata_bytes(root, block_rsv, blocksize, 0, 0);
5734 5735 5736 5737 5738 5739 5740 5741
		/*
		 * If we couldn't reserve metadata bytes try and use some from
		 * the global reserve.
		 */
		if (ret && block_rsv != global_rsv) {
			ret = block_rsv_use_bytes(global_rsv, blocksize);
			if (!ret)
				return global_rsv;
5742
			return ERR_PTR(ret);
5743
		} else if (ret) {
5744
			return ERR_PTR(ret);
5745
		}
5746 5747 5748 5749 5750 5751
		return block_rsv;
	}

	ret = block_rsv_use_bytes(block_rsv, blocksize);
	if (!ret)
		return block_rsv;
5752 5753
	if (ret) {
		WARN_ON(1);
5754
		ret = reserve_metadata_bytes(root, block_rsv, blocksize, 0, 0);
5755 5756 5757 5758 5759 5760 5761 5762
		if (!ret) {
			return block_rsv;
		} else if (ret && block_rsv != global_rsv) {
			ret = block_rsv_use_bytes(global_rsv, blocksize);
			if (!ret)
				return global_rsv;
		}
	}
5763 5764 5765 5766 5767 5768 5769 5770 5771 5772

	return ERR_PTR(-ENOSPC);
}

static void unuse_block_rsv(struct btrfs_block_rsv *block_rsv, u32 blocksize)
{
	block_rsv_add_bytes(block_rsv, blocksize, 0);
	block_rsv_release_bytes(block_rsv, NULL, 0);
}

5773
/*
5774 5775 5776 5777
 * finds a free extent and does all the dirty work required for allocation
 * returns the key for the extent through ins, and a tree buffer for
 * the first block of the extent through buf.
 *
5778 5779
 * returns the tree buffer or NULL.
 */
5780
struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
5781 5782 5783 5784
					struct btrfs_root *root, u32 blocksize,
					u64 parent, u64 root_objectid,
					struct btrfs_disk_key *key, int level,
					u64 hint, u64 empty_size)
5785
{
C
Chris Mason 已提交
5786
	struct btrfs_key ins;
5787
	struct btrfs_block_rsv *block_rsv;
5788
	struct extent_buffer *buf;
5789 5790 5791
	u64 flags = 0;
	int ret;

5792

5793 5794 5795 5796 5797 5798
	block_rsv = use_block_rsv(trans, root, blocksize);
	if (IS_ERR(block_rsv))
		return ERR_CAST(block_rsv);

	ret = btrfs_reserve_extent(trans, root, blocksize, blocksize,
				   empty_size, hint, (u64)-1, &ins, 0);
5799
	if (ret) {
5800
		unuse_block_rsv(block_rsv, blocksize);
5801
		return ERR_PTR(ret);
5802
	}
5803

5804 5805
	buf = btrfs_init_new_buffer(trans, root, ins.objectid,
				    blocksize, level);
5806 5807 5808 5809 5810 5811 5812 5813 5814 5815 5816 5817 5818 5819 5820 5821 5822 5823 5824 5825 5826 5827 5828 5829 5830 5831 5832 5833
	BUG_ON(IS_ERR(buf));

	if (root_objectid == BTRFS_TREE_RELOC_OBJECTID) {
		if (parent == 0)
			parent = ins.objectid;
		flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF;
	} else
		BUG_ON(parent > 0);

	if (root_objectid != BTRFS_TREE_LOG_OBJECTID) {
		struct btrfs_delayed_extent_op *extent_op;
		extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
		BUG_ON(!extent_op);
		if (key)
			memcpy(&extent_op->key, key, sizeof(extent_op->key));
		else
			memset(&extent_op->key, 0, sizeof(extent_op->key));
		extent_op->flags_to_set = flags;
		extent_op->update_key = 1;
		extent_op->update_flags = 1;
		extent_op->is_data = 0;

		ret = btrfs_add_delayed_tree_ref(trans, ins.objectid,
					ins.offset, parent, root_objectid,
					level, BTRFS_ADD_DELAYED_EXTENT,
					extent_op);
		BUG_ON(ret);
	}
5834 5835
	return buf;
}
5836

5837 5838 5839 5840 5841 5842 5843 5844 5845
struct walk_control {
	u64 refs[BTRFS_MAX_LEVEL];
	u64 flags[BTRFS_MAX_LEVEL];
	struct btrfs_key update_progress;
	int stage;
	int level;
	int shared_level;
	int update_ref;
	int keep_locks;
Y
Yan, Zheng 已提交
5846 5847
	int reada_slot;
	int reada_count;
5848 5849 5850 5851 5852
};

#define DROP_REFERENCE	1
#define UPDATE_BACKREF	2

Y
Yan, Zheng 已提交
5853 5854 5855 5856
static noinline void reada_walk_down(struct btrfs_trans_handle *trans,
				     struct btrfs_root *root,
				     struct walk_control *wc,
				     struct btrfs_path *path)
5857
{
Y
Yan, Zheng 已提交
5858 5859 5860
	u64 bytenr;
	u64 generation;
	u64 refs;
5861
	u64 flags;
5862
	u32 nritems;
Y
Yan, Zheng 已提交
5863 5864 5865
	u32 blocksize;
	struct btrfs_key key;
	struct extent_buffer *eb;
5866
	int ret;
Y
Yan, Zheng 已提交
5867 5868
	int slot;
	int nread = 0;
5869

Y
Yan, Zheng 已提交
5870 5871 5872 5873 5874 5875 5876 5877
	if (path->slots[wc->level] < wc->reada_slot) {
		wc->reada_count = wc->reada_count * 2 / 3;
		wc->reada_count = max(wc->reada_count, 2);
	} else {
		wc->reada_count = wc->reada_count * 3 / 2;
		wc->reada_count = min_t(int, wc->reada_count,
					BTRFS_NODEPTRS_PER_BLOCK(root));
	}
5878

Y
Yan, Zheng 已提交
5879 5880 5881
	eb = path->nodes[wc->level];
	nritems = btrfs_header_nritems(eb);
	blocksize = btrfs_level_size(root, wc->level - 1);
5882

Y
Yan, Zheng 已提交
5883 5884 5885
	for (slot = path->slots[wc->level]; slot < nritems; slot++) {
		if (nread >= wc->reada_count)
			break;
5886

C
Chris Mason 已提交
5887
		cond_resched();
Y
Yan, Zheng 已提交
5888 5889
		bytenr = btrfs_node_blockptr(eb, slot);
		generation = btrfs_node_ptr_generation(eb, slot);
C
Chris Mason 已提交
5890

Y
Yan, Zheng 已提交
5891 5892
		if (slot == path->slots[wc->level])
			goto reada;
5893

Y
Yan, Zheng 已提交
5894 5895
		if (wc->stage == UPDATE_BACKREF &&
		    generation <= root->root_key.offset)
5896 5897
			continue;

5898 5899 5900 5901 5902 5903
		/* We don't lock the tree block, it's OK to be racy here */
		ret = btrfs_lookup_extent_info(trans, root, bytenr, blocksize,
					       &refs, &flags);
		BUG_ON(ret);
		BUG_ON(refs == 0);

Y
Yan, Zheng 已提交
5904 5905 5906
		if (wc->stage == DROP_REFERENCE) {
			if (refs == 1)
				goto reada;
5907

5908 5909 5910
			if (wc->level == 1 &&
			    (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
				continue;
Y
Yan, Zheng 已提交
5911 5912 5913 5914 5915 5916 5917 5918
			if (!wc->update_ref ||
			    generation <= root->root_key.offset)
				continue;
			btrfs_node_key_to_cpu(eb, &key, slot);
			ret = btrfs_comp_cpu_keys(&key,
						  &wc->update_progress);
			if (ret < 0)
				continue;
5919 5920 5921 5922
		} else {
			if (wc->level == 1 &&
			    (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
				continue;
5923
		}
Y
Yan, Zheng 已提交
5924 5925 5926 5927
reada:
		ret = readahead_tree_block(root, bytenr, blocksize,
					   generation);
		if (ret)
5928
			break;
Y
Yan, Zheng 已提交
5929
		nread++;
C
Chris Mason 已提交
5930
	}
Y
Yan, Zheng 已提交
5931
	wc->reada_slot = slot;
C
Chris Mason 已提交
5932
}
5933

Y
Yan Zheng 已提交
5934
/*
5935 5936 5937 5938 5939 5940
 * hepler to process tree block while walking down the tree.
 *
 * when wc->stage == UPDATE_BACKREF, this function updates
 * back refs for pointers in the block.
 *
 * NOTE: return value 1 means we should stop walking down.
Y
Yan Zheng 已提交
5941
 */
5942
static noinline int walk_down_proc(struct btrfs_trans_handle *trans,
5943
				   struct btrfs_root *root,
5944
				   struct btrfs_path *path,
5945
				   struct walk_control *wc, int lookup_info)
Y
Yan Zheng 已提交
5946
{
5947 5948 5949
	int level = wc->level;
	struct extent_buffer *eb = path->nodes[level];
	u64 flag = BTRFS_BLOCK_FLAG_FULL_BACKREF;
Y
Yan Zheng 已提交
5950 5951
	int ret;

5952 5953 5954
	if (wc->stage == UPDATE_BACKREF &&
	    btrfs_header_owner(eb) != root->root_key.objectid)
		return 1;
Y
Yan Zheng 已提交
5955

5956 5957 5958 5959
	/*
	 * when reference count of tree block is 1, it won't increase
	 * again. once full backref flag is set, we never clear it.
	 */
5960 5961 5962
	if (lookup_info &&
	    ((wc->stage == DROP_REFERENCE && wc->refs[level] != 1) ||
	     (wc->stage == UPDATE_BACKREF && !(wc->flags[level] & flag)))) {
5963 5964 5965 5966 5967 5968 5969 5970
		BUG_ON(!path->locks[level]);
		ret = btrfs_lookup_extent_info(trans, root,
					       eb->start, eb->len,
					       &wc->refs[level],
					       &wc->flags[level]);
		BUG_ON(ret);
		BUG_ON(wc->refs[level] == 0);
	}
5971

5972 5973 5974
	if (wc->stage == DROP_REFERENCE) {
		if (wc->refs[level] > 1)
			return 1;
Y
Yan Zheng 已提交
5975

5976
		if (path->locks[level] && !wc->keep_locks) {
5977
			btrfs_tree_unlock_rw(eb, path->locks[level]);
5978 5979 5980 5981
			path->locks[level] = 0;
		}
		return 0;
	}
Y
Yan Zheng 已提交
5982

5983 5984 5985 5986
	/* wc->stage == UPDATE_BACKREF */
	if (!(wc->flags[level] & flag)) {
		BUG_ON(!path->locks[level]);
		ret = btrfs_inc_ref(trans, root, eb, 1);
Y
Yan Zheng 已提交
5987
		BUG_ON(ret);
5988 5989 5990 5991 5992 5993 5994 5995 5996 5997 5998 5999 6000
		ret = btrfs_dec_ref(trans, root, eb, 0);
		BUG_ON(ret);
		ret = btrfs_set_disk_extent_flags(trans, root, eb->start,
						  eb->len, flag, 0);
		BUG_ON(ret);
		wc->flags[level] |= flag;
	}

	/*
	 * the block is shared by multiple trees, so it's not good to
	 * keep the tree lock
	 */
	if (path->locks[level] && level > 0) {
6001
		btrfs_tree_unlock_rw(eb, path->locks[level]);
6002 6003 6004 6005 6006
		path->locks[level] = 0;
	}
	return 0;
}

Y
Yan, Zheng 已提交
6007 6008 6009 6010 6011 6012 6013 6014 6015 6016 6017 6018 6019 6020 6021 6022
/*
 * hepler to process tree block pointer.
 *
 * when wc->stage == DROP_REFERENCE, this function checks
 * reference count of the block pointed to. if the block
 * is shared and we need update back refs for the subtree
 * rooted at the block, this function changes wc->stage to
 * UPDATE_BACKREF. if the block is shared and there is no
 * need to update back, this function drops the reference
 * to the block.
 *
 * NOTE: return value 1 means we should stop walking down.
 */
static noinline int do_walk_down(struct btrfs_trans_handle *trans,
				 struct btrfs_root *root,
				 struct btrfs_path *path,
6023
				 struct walk_control *wc, int *lookup_info)
Y
Yan, Zheng 已提交
6024 6025 6026 6027 6028 6029 6030 6031 6032 6033 6034 6035 6036 6037 6038 6039 6040 6041 6042
{
	u64 bytenr;
	u64 generation;
	u64 parent;
	u32 blocksize;
	struct btrfs_key key;
	struct extent_buffer *next;
	int level = wc->level;
	int reada = 0;
	int ret = 0;

	generation = btrfs_node_ptr_generation(path->nodes[level],
					       path->slots[level]);
	/*
	 * if the lower level block was created before the snapshot
	 * was created, we know there is no need to update back refs
	 * for the subtree
	 */
	if (wc->stage == UPDATE_BACKREF &&
6043 6044
	    generation <= root->root_key.offset) {
		*lookup_info = 1;
Y
Yan, Zheng 已提交
6045
		return 1;
6046
	}
Y
Yan, Zheng 已提交
6047 6048 6049 6050 6051 6052 6053

	bytenr = btrfs_node_blockptr(path->nodes[level], path->slots[level]);
	blocksize = btrfs_level_size(root, level - 1);

	next = btrfs_find_tree_block(root, bytenr, blocksize);
	if (!next) {
		next = btrfs_find_create_tree_block(root, bytenr, blocksize);
6054 6055
		if (!next)
			return -ENOMEM;
Y
Yan, Zheng 已提交
6056 6057 6058 6059 6060
		reada = 1;
	}
	btrfs_tree_lock(next);
	btrfs_set_lock_blocking(next);

6061 6062 6063 6064 6065 6066
	ret = btrfs_lookup_extent_info(trans, root, bytenr, blocksize,
				       &wc->refs[level - 1],
				       &wc->flags[level - 1]);
	BUG_ON(ret);
	BUG_ON(wc->refs[level - 1] == 0);
	*lookup_info = 0;
Y
Yan, Zheng 已提交
6067

6068
	if (wc->stage == DROP_REFERENCE) {
Y
Yan, Zheng 已提交
6069
		if (wc->refs[level - 1] > 1) {
6070 6071 6072 6073
			if (level == 1 &&
			    (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
				goto skip;

Y
Yan, Zheng 已提交
6074 6075 6076 6077 6078 6079 6080 6081 6082 6083 6084 6085 6086
			if (!wc->update_ref ||
			    generation <= root->root_key.offset)
				goto skip;

			btrfs_node_key_to_cpu(path->nodes[level], &key,
					      path->slots[level]);
			ret = btrfs_comp_cpu_keys(&key, &wc->update_progress);
			if (ret < 0)
				goto skip;

			wc->stage = UPDATE_BACKREF;
			wc->shared_level = level - 1;
		}
6087 6088 6089 6090
	} else {
		if (level == 1 &&
		    (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
			goto skip;
Y
Yan, Zheng 已提交
6091 6092 6093 6094 6095 6096
	}

	if (!btrfs_buffer_uptodate(next, generation)) {
		btrfs_tree_unlock(next);
		free_extent_buffer(next);
		next = NULL;
6097
		*lookup_info = 1;
Y
Yan, Zheng 已提交
6098 6099 6100 6101 6102 6103
	}

	if (!next) {
		if (reada && level == 1)
			reada_walk_down(trans, root, wc, path);
		next = read_tree_block(root, bytenr, blocksize, generation);
6104 6105
		if (!next)
			return -EIO;
Y
Yan, Zheng 已提交
6106 6107 6108 6109 6110 6111 6112 6113
		btrfs_tree_lock(next);
		btrfs_set_lock_blocking(next);
	}

	level--;
	BUG_ON(level != btrfs_header_level(next));
	path->nodes[level] = next;
	path->slots[level] = 0;
6114
	path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
Y
Yan, Zheng 已提交
6115 6116 6117 6118 6119 6120 6121
	wc->level = level;
	if (wc->level == 1)
		wc->reada_slot = 0;
	return 0;
skip:
	wc->refs[level - 1] = 0;
	wc->flags[level - 1] = 0;
6122 6123 6124 6125 6126 6127 6128 6129
	if (wc->stage == DROP_REFERENCE) {
		if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) {
			parent = path->nodes[level]->start;
		} else {
			BUG_ON(root->root_key.objectid !=
			       btrfs_header_owner(path->nodes[level]));
			parent = 0;
		}
Y
Yan, Zheng 已提交
6130

6131 6132 6133
		ret = btrfs_free_extent(trans, root, bytenr, blocksize, parent,
					root->root_key.objectid, level - 1, 0);
		BUG_ON(ret);
Y
Yan, Zheng 已提交
6134 6135 6136
	}
	btrfs_tree_unlock(next);
	free_extent_buffer(next);
6137
	*lookup_info = 1;
Y
Yan, Zheng 已提交
6138 6139 6140
	return 1;
}

6141 6142 6143 6144 6145 6146 6147 6148 6149 6150 6151 6152 6153 6154 6155 6156 6157
/*
 * hepler to process tree block while walking up the tree.
 *
 * when wc->stage == DROP_REFERENCE, this function drops
 * reference count on the block.
 *
 * when wc->stage == UPDATE_BACKREF, this function changes
 * wc->stage back to DROP_REFERENCE if we changed wc->stage
 * to UPDATE_BACKREF previously while processing the block.
 *
 * NOTE: return value 1 means we should stop walking up.
 */
static noinline int walk_up_proc(struct btrfs_trans_handle *trans,
				 struct btrfs_root *root,
				 struct btrfs_path *path,
				 struct walk_control *wc)
{
6158
	int ret;
6159 6160 6161 6162 6163 6164 6165 6166 6167 6168 6169 6170 6171 6172 6173 6174 6175 6176 6177 6178 6179 6180 6181 6182 6183 6184
	int level = wc->level;
	struct extent_buffer *eb = path->nodes[level];
	u64 parent = 0;

	if (wc->stage == UPDATE_BACKREF) {
		BUG_ON(wc->shared_level < level);
		if (level < wc->shared_level)
			goto out;

		ret = find_next_key(path, level + 1, &wc->update_progress);
		if (ret > 0)
			wc->update_ref = 0;

		wc->stage = DROP_REFERENCE;
		wc->shared_level = -1;
		path->slots[level] = 0;

		/*
		 * check reference count again if the block isn't locked.
		 * we should start walking down the tree again if reference
		 * count is one.
		 */
		if (!path->locks[level]) {
			BUG_ON(level == 0);
			btrfs_tree_lock(eb);
			btrfs_set_lock_blocking(eb);
6185
			path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
6186 6187 6188 6189 6190

			ret = btrfs_lookup_extent_info(trans, root,
						       eb->start, eb->len,
						       &wc->refs[level],
						       &wc->flags[level]);
Y
Yan Zheng 已提交
6191
			BUG_ON(ret);
6192 6193
			BUG_ON(wc->refs[level] == 0);
			if (wc->refs[level] == 1) {
6194
				btrfs_tree_unlock_rw(eb, path->locks[level]);
6195 6196
				return 1;
			}
Y
Yan Zheng 已提交
6197
		}
6198
	}
Y
Yan Zheng 已提交
6199

6200 6201
	/* wc->stage == DROP_REFERENCE */
	BUG_ON(wc->refs[level] > 1 && !path->locks[level]);
6202

6203 6204 6205 6206 6207 6208 6209 6210 6211 6212 6213 6214 6215
	if (wc->refs[level] == 1) {
		if (level == 0) {
			if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
				ret = btrfs_dec_ref(trans, root, eb, 1);
			else
				ret = btrfs_dec_ref(trans, root, eb, 0);
			BUG_ON(ret);
		}
		/* make block locked assertion in clean_tree_block happy */
		if (!path->locks[level] &&
		    btrfs_header_generation(eb) == trans->transid) {
			btrfs_tree_lock(eb);
			btrfs_set_lock_blocking(eb);
6216
			path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
6217 6218 6219 6220 6221 6222 6223 6224 6225 6226 6227 6228 6229 6230 6231 6232
		}
		clean_tree_block(trans, root, eb);
	}

	if (eb == root->node) {
		if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
			parent = eb->start;
		else
			BUG_ON(root->root_key.objectid !=
			       btrfs_header_owner(eb));
	} else {
		if (wc->flags[level + 1] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
			parent = path->nodes[level + 1]->start;
		else
			BUG_ON(root->root_key.objectid !=
			       btrfs_header_owner(path->nodes[level + 1]));
Y
Yan Zheng 已提交
6233 6234
	}

6235
	btrfs_free_tree_block(trans, root, eb, parent, wc->refs[level] == 1);
6236 6237 6238
out:
	wc->refs[level] = 0;
	wc->flags[level] = 0;
6239
	return 0;
6240 6241 6242 6243 6244 6245 6246 6247
}

static noinline int walk_down_tree(struct btrfs_trans_handle *trans,
				   struct btrfs_root *root,
				   struct btrfs_path *path,
				   struct walk_control *wc)
{
	int level = wc->level;
6248
	int lookup_info = 1;
6249 6250 6251
	int ret;

	while (level >= 0) {
6252
		ret = walk_down_proc(trans, root, path, wc, lookup_info);
6253 6254 6255 6256 6257 6258
		if (ret > 0)
			break;

		if (level == 0)
			break;

6259 6260 6261 6262
		if (path->slots[level] >=
		    btrfs_header_nritems(path->nodes[level]))
			break;

6263
		ret = do_walk_down(trans, root, path, wc, &lookup_info);
Y
Yan, Zheng 已提交
6264 6265 6266
		if (ret > 0) {
			path->slots[level]++;
			continue;
6267 6268
		} else if (ret < 0)
			return ret;
Y
Yan, Zheng 已提交
6269
		level = wc->level;
Y
Yan Zheng 已提交
6270 6271 6272 6273
	}
	return 0;
}

C
Chris Mason 已提交
6274
static noinline int walk_up_tree(struct btrfs_trans_handle *trans,
6275
				 struct btrfs_root *root,
Y
Yan Zheng 已提交
6276
				 struct btrfs_path *path,
6277
				 struct walk_control *wc, int max_level)
C
Chris Mason 已提交
6278
{
6279
	int level = wc->level;
C
Chris Mason 已提交
6280
	int ret;
6281

6282 6283 6284 6285 6286 6287
	path->slots[level] = btrfs_header_nritems(path->nodes[level]);
	while (level < max_level && path->nodes[level]) {
		wc->level = level;
		if (path->slots[level] + 1 <
		    btrfs_header_nritems(path->nodes[level])) {
			path->slots[level]++;
C
Chris Mason 已提交
6288 6289
			return 0;
		} else {
6290 6291 6292
			ret = walk_up_proc(trans, root, path, wc);
			if (ret > 0)
				return 0;
6293

6294
			if (path->locks[level]) {
6295 6296
				btrfs_tree_unlock_rw(path->nodes[level],
						     path->locks[level]);
6297
				path->locks[level] = 0;
Y
Yan Zheng 已提交
6298
			}
6299 6300 6301
			free_extent_buffer(path->nodes[level]);
			path->nodes[level] = NULL;
			level++;
C
Chris Mason 已提交
6302 6303 6304 6305 6306
		}
	}
	return 1;
}

C
Chris Mason 已提交
6307
/*
6308 6309 6310 6311 6312 6313 6314 6315 6316
 * drop a subvolume tree.
 *
 * this function traverses the tree freeing any blocks that only
 * referenced by the tree.
 *
 * when a shared tree block is found. this function decreases its
 * reference count by one. if update_ref is true, this function
 * also make sure backrefs for the shared block and all lower level
 * blocks are properly updated.
C
Chris Mason 已提交
6317
 */
6318 6319
void btrfs_drop_snapshot(struct btrfs_root *root,
			 struct btrfs_block_rsv *block_rsv, int update_ref)
C
Chris Mason 已提交
6320
{
6321
	struct btrfs_path *path;
6322 6323
	struct btrfs_trans_handle *trans;
	struct btrfs_root *tree_root = root->fs_info->tree_root;
6324
	struct btrfs_root_item *root_item = &root->root_item;
6325 6326 6327 6328 6329
	struct walk_control *wc;
	struct btrfs_key key;
	int err = 0;
	int ret;
	int level;
C
Chris Mason 已提交
6330

6331
	path = btrfs_alloc_path();
6332 6333 6334 6335
	if (!path) {
		err = -ENOMEM;
		goto out;
	}
C
Chris Mason 已提交
6336

6337
	wc = kzalloc(sizeof(*wc), GFP_NOFS);
6338 6339
	if (!wc) {
		btrfs_free_path(path);
6340 6341
		err = -ENOMEM;
		goto out;
6342
	}
6343

6344
	trans = btrfs_start_transaction(tree_root, 0);
6345 6346
	BUG_ON(IS_ERR(trans));

6347 6348
	if (block_rsv)
		trans->block_rsv = block_rsv;
6349

6350
	if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
6351
		level = btrfs_header_level(root->node);
6352 6353
		path->nodes[level] = btrfs_lock_root_node(root);
		btrfs_set_lock_blocking(path->nodes[level]);
6354
		path->slots[level] = 0;
6355
		path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
6356 6357
		memset(&wc->update_progress, 0,
		       sizeof(wc->update_progress));
6358 6359
	} else {
		btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
6360 6361 6362
		memcpy(&wc->update_progress, &key,
		       sizeof(wc->update_progress));

6363
		level = root_item->drop_level;
6364
		BUG_ON(level == 0);
6365
		path->lowest_level = level;
6366 6367 6368 6369
		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
		path->lowest_level = 0;
		if (ret < 0) {
			err = ret;
6370
			goto out_free;
6371
		}
Y
Yan, Zheng 已提交
6372
		WARN_ON(ret > 0);
6373

6374 6375 6376 6377
		/*
		 * unlock our path, this is safe because only this
		 * function is allowed to delete this snapshot
		 */
6378
		btrfs_unlock_up_safe(path, 0);
6379 6380 6381 6382 6383 6384 6385 6386 6387 6388 6389 6390 6391 6392 6393 6394 6395 6396 6397 6398 6399

		level = btrfs_header_level(root->node);
		while (1) {
			btrfs_tree_lock(path->nodes[level]);
			btrfs_set_lock_blocking(path->nodes[level]);

			ret = btrfs_lookup_extent_info(trans, root,
						path->nodes[level]->start,
						path->nodes[level]->len,
						&wc->refs[level],
						&wc->flags[level]);
			BUG_ON(ret);
			BUG_ON(wc->refs[level] == 0);

			if (level == root_item->drop_level)
				break;

			btrfs_tree_unlock(path->nodes[level]);
			WARN_ON(wc->refs[level] != 1);
			level--;
		}
6400
	}
6401 6402 6403 6404 6405 6406

	wc->level = level;
	wc->shared_level = -1;
	wc->stage = DROP_REFERENCE;
	wc->update_ref = update_ref;
	wc->keep_locks = 0;
Y
Yan, Zheng 已提交
6407
	wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root);
6408

C
Chris Mason 已提交
6409
	while (1) {
6410 6411 6412
		ret = walk_down_tree(trans, root, path, wc);
		if (ret < 0) {
			err = ret;
C
Chris Mason 已提交
6413
			break;
6414
		}
C
Chris Mason 已提交
6415

6416 6417 6418
		ret = walk_up_tree(trans, root, path, wc, BTRFS_MAX_LEVEL);
		if (ret < 0) {
			err = ret;
C
Chris Mason 已提交
6419
			break;
6420 6421 6422 6423
		}

		if (ret > 0) {
			BUG_ON(wc->stage != DROP_REFERENCE);
6424 6425
			break;
		}
6426 6427 6428 6429 6430 6431 6432 6433 6434 6435

		if (wc->stage == DROP_REFERENCE) {
			level = wc->level;
			btrfs_node_key(path->nodes[level],
				       &root_item->drop_progress,
				       path->slots[level]);
			root_item->drop_level = level;
		}

		BUG_ON(wc->level == 0);
6436
		if (btrfs_should_end_transaction(trans, tree_root)) {
6437 6438 6439 6440 6441
			ret = btrfs_update_root(trans, tree_root,
						&root->root_key,
						root_item);
			BUG_ON(ret);

6442
			btrfs_end_transaction_throttle(trans, tree_root);
6443
			trans = btrfs_start_transaction(tree_root, 0);
6444
			BUG_ON(IS_ERR(trans));
6445 6446
			if (block_rsv)
				trans->block_rsv = block_rsv;
6447
		}
C
Chris Mason 已提交
6448
	}
6449
	btrfs_release_path(path);
6450 6451 6452 6453 6454
	BUG_ON(err);

	ret = btrfs_del_root(trans, tree_root, &root->root_key);
	BUG_ON(ret);

6455 6456 6457 6458 6459
	if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
		ret = btrfs_find_last_root(tree_root, root->root_key.objectid,
					   NULL, NULL);
		BUG_ON(ret < 0);
		if (ret > 0) {
6460 6461 6462 6463 6464 6465 6466
			/* if we fail to delete the orphan item this time
			 * around, it'll get picked up the next time.
			 *
			 * The most common failure here is just -ENOENT.
			 */
			btrfs_del_orphan_item(trans, tree_root,
					      root->root_key.objectid);
6467 6468 6469 6470 6471 6472 6473 6474 6475 6476
		}
	}

	if (root->in_radix) {
		btrfs_free_fs_root(tree_root->fs_info, root);
	} else {
		free_extent_buffer(root->node);
		free_extent_buffer(root->commit_root);
		kfree(root);
	}
6477
out_free:
6478
	btrfs_end_transaction_throttle(trans, tree_root);
6479
	kfree(wc);
6480
	btrfs_free_path(path);
6481 6482 6483 6484
out:
	if (err)
		btrfs_std_error(root->fs_info, err);
	return;
C
Chris Mason 已提交
6485
}
C
Chris Mason 已提交
6486

6487 6488 6489 6490 6491
/*
 * drop subtree rooted at tree block 'node'.
 *
 * NOTE: this function will unlock and release tree block 'node'
 */
Y
Yan Zheng 已提交
6492 6493 6494 6495 6496 6497
int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
			struct btrfs_root *root,
			struct extent_buffer *node,
			struct extent_buffer *parent)
{
	struct btrfs_path *path;
6498
	struct walk_control *wc;
Y
Yan Zheng 已提交
6499 6500 6501 6502 6503
	int level;
	int parent_level;
	int ret = 0;
	int wret;

6504 6505
	BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);

Y
Yan Zheng 已提交
6506
	path = btrfs_alloc_path();
T
Tsutomu Itoh 已提交
6507 6508
	if (!path)
		return -ENOMEM;
Y
Yan Zheng 已提交
6509

6510
	wc = kzalloc(sizeof(*wc), GFP_NOFS);
T
Tsutomu Itoh 已提交
6511 6512 6513 6514
	if (!wc) {
		btrfs_free_path(path);
		return -ENOMEM;
	}
6515

6516
	btrfs_assert_tree_locked(parent);
Y
Yan Zheng 已提交
6517 6518 6519 6520 6521
	parent_level = btrfs_header_level(parent);
	extent_buffer_get(parent);
	path->nodes[parent_level] = parent;
	path->slots[parent_level] = btrfs_header_nritems(parent);

6522
	btrfs_assert_tree_locked(node);
Y
Yan Zheng 已提交
6523 6524 6525
	level = btrfs_header_level(node);
	path->nodes[level] = node;
	path->slots[level] = 0;
6526
	path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
6527 6528 6529 6530 6531 6532 6533 6534

	wc->refs[parent_level] = 1;
	wc->flags[parent_level] = BTRFS_BLOCK_FLAG_FULL_BACKREF;
	wc->level = level;
	wc->shared_level = -1;
	wc->stage = DROP_REFERENCE;
	wc->update_ref = 0;
	wc->keep_locks = 1;
Y
Yan, Zheng 已提交
6535
	wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root);
Y
Yan Zheng 已提交
6536 6537

	while (1) {
6538 6539
		wret = walk_down_tree(trans, root, path, wc);
		if (wret < 0) {
Y
Yan Zheng 已提交
6540 6541
			ret = wret;
			break;
6542
		}
Y
Yan Zheng 已提交
6543

6544
		wret = walk_up_tree(trans, root, path, wc, parent_level);
Y
Yan Zheng 已提交
6545 6546 6547 6548 6549 6550
		if (wret < 0)
			ret = wret;
		if (wret != 0)
			break;
	}

6551
	kfree(wc);
Y
Yan Zheng 已提交
6552 6553 6554 6555
	btrfs_free_path(path);
	return ret;
}

6556 6557 6558 6559 6560 6561
static u64 update_block_group_flags(struct btrfs_root *root, u64 flags)
{
	u64 num_devices;
	u64 stripped = BTRFS_BLOCK_GROUP_RAID0 |
		BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;

6562 6563 6564 6565 6566 6567 6568 6569
	/*
	 * we add in the count of missing devices because we want
	 * to make sure that any RAID levels on a degraded FS
	 * continue to be honored.
	 */
	num_devices = root->fs_info->fs_devices->rw_devices +
		root->fs_info->fs_devices->missing_devices;

6570 6571 6572 6573 6574 6575 6576 6577 6578 6579 6580 6581 6582 6583 6584 6585 6586 6587 6588 6589 6590 6591 6592 6593 6594 6595 6596 6597 6598 6599 6600
	if (num_devices == 1) {
		stripped |= BTRFS_BLOCK_GROUP_DUP;
		stripped = flags & ~stripped;

		/* turn raid0 into single device chunks */
		if (flags & BTRFS_BLOCK_GROUP_RAID0)
			return stripped;

		/* turn mirroring into duplication */
		if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
			     BTRFS_BLOCK_GROUP_RAID10))
			return stripped | BTRFS_BLOCK_GROUP_DUP;
		return flags;
	} else {
		/* they already had raid on here, just return */
		if (flags & stripped)
			return flags;

		stripped |= BTRFS_BLOCK_GROUP_DUP;
		stripped = flags & ~stripped;

		/* switch duplicated blocks with raid1 */
		if (flags & BTRFS_BLOCK_GROUP_DUP)
			return stripped | BTRFS_BLOCK_GROUP_RAID1;

		/* turn single device chunks into raid0 */
		return stripped | BTRFS_BLOCK_GROUP_RAID0;
	}
	return flags;
}

6601
static int set_block_group_ro(struct btrfs_block_group_cache *cache, int force)
C
Chris Mason 已提交
6602
{
6603 6604
	struct btrfs_space_info *sinfo = cache->space_info;
	u64 num_bytes;
6605
	u64 min_allocable_bytes;
6606
	int ret = -ENOSPC;
C
Chris Mason 已提交
6607

6608

6609 6610 6611 6612 6613 6614 6615 6616 6617 6618 6619 6620
	/*
	 * We need some metadata space and system metadata space for
	 * allocating chunks in some corner cases until we force to set
	 * it to be readonly.
	 */
	if ((sinfo->flags &
	     (BTRFS_BLOCK_GROUP_SYSTEM | BTRFS_BLOCK_GROUP_METADATA)) &&
	    !force)
		min_allocable_bytes = 1 * 1024 * 1024;
	else
		min_allocable_bytes = 0;

6621 6622
	spin_lock(&sinfo->lock);
	spin_lock(&cache->lock);
6623 6624 6625 6626 6627 6628

	if (cache->ro) {
		ret = 0;
		goto out;
	}

6629 6630 6631 6632
	num_bytes = cache->key.offset - cache->reserved - cache->pinned -
		    cache->bytes_super - btrfs_block_group_used(&cache->item);

	if (sinfo->bytes_used + sinfo->bytes_reserved + sinfo->bytes_pinned +
6633 6634
	    sinfo->bytes_may_use + sinfo->bytes_readonly + num_bytes +
	    min_allocable_bytes <= sinfo->total_bytes) {
6635 6636 6637 6638
		sinfo->bytes_readonly += num_bytes;
		cache->ro = 1;
		ret = 0;
	}
6639
out:
6640 6641 6642 6643
	spin_unlock(&cache->lock);
	spin_unlock(&sinfo->lock);
	return ret;
}
6644

6645 6646
int btrfs_set_block_group_ro(struct btrfs_root *root,
			     struct btrfs_block_group_cache *cache)
6647

6648 6649 6650 6651
{
	struct btrfs_trans_handle *trans;
	u64 alloc_flags;
	int ret;
6652

6653
	BUG_ON(cache->ro);
C
Chris Mason 已提交
6654

C
Chris Mason 已提交
6655
	trans = btrfs_join_transaction(root);
6656
	BUG_ON(IS_ERR(trans));
6657

6658 6659
	alloc_flags = update_block_group_flags(root, cache->flags);
	if (alloc_flags != cache->flags)
6660 6661
		do_chunk_alloc(trans, root, 2 * 1024 * 1024, alloc_flags,
			       CHUNK_ALLOC_FORCE);
6662

6663
	ret = set_block_group_ro(cache, 0);
6664 6665 6666
	if (!ret)
		goto out;
	alloc_flags = get_alloc_profile(root, cache->space_info->flags);
6667 6668
	ret = do_chunk_alloc(trans, root, 2 * 1024 * 1024, alloc_flags,
			     CHUNK_ALLOC_FORCE);
6669 6670
	if (ret < 0)
		goto out;
6671
	ret = set_block_group_ro(cache, 0);
6672 6673 6674 6675
out:
	btrfs_end_transaction(trans, root);
	return ret;
}
6676

6677 6678 6679 6680
int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans,
			    struct btrfs_root *root, u64 type)
{
	u64 alloc_flags = get_alloc_profile(root, type);
6681 6682
	return do_chunk_alloc(trans, root, 2 * 1024 * 1024, alloc_flags,
			      CHUNK_ALLOC_FORCE);
6683 6684
}

6685 6686 6687 6688 6689 6690 6691 6692 6693 6694 6695 6696 6697 6698 6699 6700 6701 6702 6703 6704 6705 6706 6707 6708 6709 6710 6711 6712 6713 6714 6715 6716 6717 6718 6719 6720 6721 6722 6723 6724 6725 6726 6727 6728 6729 6730 6731 6732 6733 6734 6735 6736 6737 6738 6739 6740
/*
 * helper to account the unused space of all the readonly block group in the
 * list. takes mirrors into account.
 */
static u64 __btrfs_get_ro_block_group_free_space(struct list_head *groups_list)
{
	struct btrfs_block_group_cache *block_group;
	u64 free_bytes = 0;
	int factor;

	list_for_each_entry(block_group, groups_list, list) {
		spin_lock(&block_group->lock);

		if (!block_group->ro) {
			spin_unlock(&block_group->lock);
			continue;
		}

		if (block_group->flags & (BTRFS_BLOCK_GROUP_RAID1 |
					  BTRFS_BLOCK_GROUP_RAID10 |
					  BTRFS_BLOCK_GROUP_DUP))
			factor = 2;
		else
			factor = 1;

		free_bytes += (block_group->key.offset -
			       btrfs_block_group_used(&block_group->item)) *
			       factor;

		spin_unlock(&block_group->lock);
	}

	return free_bytes;
}

/*
 * helper to account the unused space of all the readonly block group in the
 * space_info. takes mirrors into account.
 */
u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo)
{
	int i;
	u64 free_bytes = 0;

	spin_lock(&sinfo->lock);

	for(i = 0; i < BTRFS_NR_RAID_TYPES; i++)
		if (!list_empty(&sinfo->block_groups[i]))
			free_bytes += __btrfs_get_ro_block_group_free_space(
						&sinfo->block_groups[i]);

	spin_unlock(&sinfo->lock);

	return free_bytes;
}

6741 6742
int btrfs_set_block_group_rw(struct btrfs_root *root,
			      struct btrfs_block_group_cache *cache)
6743
{
6744 6745 6746 6747 6748 6749 6750 6751 6752 6753 6754 6755 6756
	struct btrfs_space_info *sinfo = cache->space_info;
	u64 num_bytes;

	BUG_ON(!cache->ro);

	spin_lock(&sinfo->lock);
	spin_lock(&cache->lock);
	num_bytes = cache->key.offset - cache->reserved - cache->pinned -
		    cache->bytes_super - btrfs_block_group_used(&cache->item);
	sinfo->bytes_readonly -= num_bytes;
	cache->ro = 0;
	spin_unlock(&cache->lock);
	spin_unlock(&sinfo->lock);
6757 6758 6759
	return 0;
}

6760 6761 6762 6763 6764 6765 6766
/*
 * checks to see if its even possible to relocate this block group.
 *
 * @return - -1 if it's not a good idea to relocate this block group, 0 if its
 * ok to go ahead and try.
 */
int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr)
Z
Zheng Yan 已提交
6767
{
6768 6769 6770 6771
	struct btrfs_block_group_cache *block_group;
	struct btrfs_space_info *space_info;
	struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
	struct btrfs_device *device;
6772
	u64 min_free;
J
Josef Bacik 已提交
6773 6774
	u64 dev_min = 1;
	u64 dev_nr = 0;
6775
	int index;
6776 6777
	int full = 0;
	int ret = 0;
Z
Zheng Yan 已提交
6778

6779
	block_group = btrfs_lookup_block_group(root->fs_info, bytenr);
Z
Zheng Yan 已提交
6780

6781 6782 6783
	/* odd, couldn't find the block group, leave it alone */
	if (!block_group)
		return -1;
Z
Zheng Yan 已提交
6784

6785 6786
	min_free = btrfs_block_group_used(&block_group->item);

6787
	/* no bytes used, we're good */
6788
	if (!min_free)
Z
Zheng Yan 已提交
6789 6790
		goto out;

6791 6792
	space_info = block_group->space_info;
	spin_lock(&space_info->lock);
6793

6794
	full = space_info->full;
6795

6796 6797
	/*
	 * if this is the last block group we have in this space, we can't
6798 6799 6800 6801
	 * relocate it unless we're able to allocate a new chunk below.
	 *
	 * Otherwise, we need to make sure we have room in the space to handle
	 * all of the extents from this block group.  If we can, we're good
6802
	 */
6803
	if ((space_info->total_bytes != block_group->key.offset) &&
6804 6805 6806
	    (space_info->bytes_used + space_info->bytes_reserved +
	     space_info->bytes_pinned + space_info->bytes_readonly +
	     min_free < space_info->total_bytes)) {
6807 6808
		spin_unlock(&space_info->lock);
		goto out;
6809
	}
6810
	spin_unlock(&space_info->lock);
6811

6812 6813 6814 6815 6816 6817 6818 6819 6820 6821
	/*
	 * ok we don't have enough space, but maybe we have free space on our
	 * devices to allocate new chunks for relocation, so loop through our
	 * alloc devices and guess if we have enough space.  However, if we
	 * were marked as full, then we know there aren't enough chunks, and we
	 * can just return.
	 */
	ret = -1;
	if (full)
		goto out;
6822

6823 6824 6825 6826 6827 6828 6829 6830 6831 6832 6833
	/*
	 * index:
	 *      0: raid10
	 *      1: raid1
	 *      2: dup
	 *      3: raid0
	 *      4: single
	 */
	index = get_block_group_index(block_group);
	if (index == 0) {
		dev_min = 4;
J
Josef Bacik 已提交
6834 6835
		/* Divide by 2 */
		min_free >>= 1;
6836 6837 6838
	} else if (index == 1) {
		dev_min = 2;
	} else if (index == 2) {
J
Josef Bacik 已提交
6839 6840
		/* Multiply by 2 */
		min_free <<= 1;
6841 6842
	} else if (index == 3) {
		dev_min = fs_devices->rw_devices;
J
Josef Bacik 已提交
6843
		do_div(min_free, dev_min);
6844 6845
	}

6846 6847
	mutex_lock(&root->fs_info->chunk_mutex);
	list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) {
6848
		u64 dev_offset;
6849

6850 6851 6852 6853 6854 6855
		/*
		 * check to make sure we can actually find a chunk with enough
		 * space to fit our block group in.
		 */
		if (device->total_bytes > device->bytes_used + min_free) {
			ret = find_free_dev_extent(NULL, device, min_free,
6856
						   &dev_offset, NULL);
6857
			if (!ret)
6858 6859 6860
				dev_nr++;

			if (dev_nr >= dev_min)
6861
				break;
6862

6863
			ret = -1;
6864
		}
6865
	}
6866
	mutex_unlock(&root->fs_info->chunk_mutex);
6867
out:
6868
	btrfs_put_block_group(block_group);
6869 6870 6871
	return ret;
}

6872 6873
static int find_first_block_group(struct btrfs_root *root,
		struct btrfs_path *path, struct btrfs_key *key)
6874
{
6875
	int ret = 0;
6876 6877 6878
	struct btrfs_key found_key;
	struct extent_buffer *leaf;
	int slot;
6879

6880 6881
	ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
	if (ret < 0)
6882 6883
		goto out;

C
Chris Mason 已提交
6884
	while (1) {
6885
		slot = path->slots[0];
6886
		leaf = path->nodes[0];
6887 6888 6889 6890 6891
		if (slot >= btrfs_header_nritems(leaf)) {
			ret = btrfs_next_leaf(root, path);
			if (ret == 0)
				continue;
			if (ret < 0)
6892
				goto out;
6893
			break;
6894
		}
6895
		btrfs_item_key_to_cpu(leaf, &found_key, slot);
6896

6897
		if (found_key.objectid >= key->objectid &&
6898 6899 6900 6901
		    found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
			ret = 0;
			goto out;
		}
6902
		path->slots[0]++;
6903
	}
6904
out:
6905
	return ret;
6906 6907
}

6908 6909 6910 6911 6912 6913 6914 6915 6916 6917 6918 6919 6920 6921 6922 6923 6924 6925 6926 6927 6928 6929 6930 6931 6932 6933 6934 6935 6936 6937 6938 6939 6940 6941
void btrfs_put_block_group_cache(struct btrfs_fs_info *info)
{
	struct btrfs_block_group_cache *block_group;
	u64 last = 0;

	while (1) {
		struct inode *inode;

		block_group = btrfs_lookup_first_block_group(info, last);
		while (block_group) {
			spin_lock(&block_group->lock);
			if (block_group->iref)
				break;
			spin_unlock(&block_group->lock);
			block_group = next_block_group(info->tree_root,
						       block_group);
		}
		if (!block_group) {
			if (last == 0)
				break;
			last = 0;
			continue;
		}

		inode = block_group->inode;
		block_group->iref = 0;
		block_group->inode = NULL;
		spin_unlock(&block_group->lock);
		iput(inode);
		last = block_group->key.objectid + block_group->key.offset;
		btrfs_put_block_group(block_group);
	}
}

Z
Zheng Yan 已提交
6942 6943 6944
int btrfs_free_block_groups(struct btrfs_fs_info *info)
{
	struct btrfs_block_group_cache *block_group;
6945
	struct btrfs_space_info *space_info;
6946
	struct btrfs_caching_control *caching_ctl;
Z
Zheng Yan 已提交
6947 6948
	struct rb_node *n;

6949 6950 6951 6952 6953 6954 6955 6956 6957
	down_write(&info->extent_commit_sem);
	while (!list_empty(&info->caching_block_groups)) {
		caching_ctl = list_entry(info->caching_block_groups.next,
					 struct btrfs_caching_control, list);
		list_del(&caching_ctl->list);
		put_caching_control(caching_ctl);
	}
	up_write(&info->extent_commit_sem);

Z
Zheng Yan 已提交
6958 6959 6960 6961 6962 6963
	spin_lock(&info->block_group_cache_lock);
	while ((n = rb_last(&info->block_group_cache_tree)) != NULL) {
		block_group = rb_entry(n, struct btrfs_block_group_cache,
				       cache_node);
		rb_erase(&block_group->cache_node,
			 &info->block_group_cache_tree);
Y
Yan Zheng 已提交
6964 6965
		spin_unlock(&info->block_group_cache_lock);

6966
		down_write(&block_group->space_info->groups_sem);
Z
Zheng Yan 已提交
6967
		list_del(&block_group->list);
6968
		up_write(&block_group->space_info->groups_sem);
6969

J
Josef Bacik 已提交
6970
		if (block_group->cached == BTRFS_CACHE_STARTED)
6971
			wait_block_group_cache_done(block_group);
J
Josef Bacik 已提交
6972

6973 6974 6975 6976 6977 6978 6979
		/*
		 * We haven't cached this block group, which means we could
		 * possibly have excluded extents on this block group.
		 */
		if (block_group->cached == BTRFS_CACHE_NO)
			free_excluded_extents(info->extent_root, block_group);

J
Josef Bacik 已提交
6980
		btrfs_remove_free_space_cache(block_group);
6981
		btrfs_put_block_group(block_group);
Y
Yan Zheng 已提交
6982 6983

		spin_lock(&info->block_group_cache_lock);
Z
Zheng Yan 已提交
6984 6985
	}
	spin_unlock(&info->block_group_cache_lock);
6986 6987 6988 6989 6990 6991 6992 6993 6994

	/* now that all the block groups are freed, go through and
	 * free all the space_info structs.  This is only called during
	 * the final stages of unmount, and so we know nobody is
	 * using them.  We call synchronize_rcu() once before we start,
	 * just to be on the safe side.
	 */
	synchronize_rcu();

6995 6996
	release_global_block_rsv(info);

6997 6998 6999 7000
	while(!list_empty(&info->space_info)) {
		space_info = list_entry(info->space_info.next,
					struct btrfs_space_info,
					list);
7001
		if (space_info->bytes_pinned > 0 ||
7002 7003
		    space_info->bytes_reserved > 0 ||
		    space_info->bytes_may_use > 0) {
7004 7005 7006
			WARN_ON(1);
			dump_space_info(space_info, 0, 0);
		}
7007 7008 7009
		list_del(&space_info->list);
		kfree(space_info);
	}
Z
Zheng Yan 已提交
7010 7011 7012
	return 0;
}

7013 7014 7015 7016 7017 7018 7019 7020 7021 7022
static void __link_block_group(struct btrfs_space_info *space_info,
			       struct btrfs_block_group_cache *cache)
{
	int index = get_block_group_index(cache);

	down_write(&space_info->groups_sem);
	list_add_tail(&cache->list, &space_info->block_groups[index]);
	up_write(&space_info->groups_sem);
}

C
Chris Mason 已提交
7023 7024 7025 7026 7027
int btrfs_read_block_groups(struct btrfs_root *root)
{
	struct btrfs_path *path;
	int ret;
	struct btrfs_block_group_cache *cache;
C
Chris Mason 已提交
7028
	struct btrfs_fs_info *info = root->fs_info;
7029
	struct btrfs_space_info *space_info;
C
Chris Mason 已提交
7030 7031
	struct btrfs_key key;
	struct btrfs_key found_key;
7032
	struct extent_buffer *leaf;
7033 7034
	int need_clear = 0;
	u64 cache_gen;
7035

C
Chris Mason 已提交
7036
	root = info->extent_root;
C
Chris Mason 已提交
7037
	key.objectid = 0;
7038
	key.offset = 0;
C
Chris Mason 已提交
7039 7040 7041 7042
	btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;
J
Josef Bacik 已提交
7043
	path->reada = 1;
C
Chris Mason 已提交
7044

7045
	cache_gen = btrfs_super_cache_generation(&root->fs_info->super_copy);
7046
	if (btrfs_test_opt(root, SPACE_CACHE) &&
7047 7048
	    btrfs_super_generation(&root->fs_info->super_copy) != cache_gen)
		need_clear = 1;
7049 7050
	if (btrfs_test_opt(root, CLEAR_CACHE))
		need_clear = 1;
7051

C
Chris Mason 已提交
7052
	while (1) {
7053
		ret = find_first_block_group(root, path, &key);
7054 7055
		if (ret > 0)
			break;
7056 7057
		if (ret != 0)
			goto error;
7058 7059
		leaf = path->nodes[0];
		btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
7060
		cache = kzalloc(sizeof(*cache), GFP_NOFS);
C
Chris Mason 已提交
7061
		if (!cache) {
7062
			ret = -ENOMEM;
7063
			goto error;
C
Chris Mason 已提交
7064
		}
7065 7066 7067 7068 7069 7070 7071
		cache->free_space_ctl = kzalloc(sizeof(*cache->free_space_ctl),
						GFP_NOFS);
		if (!cache->free_space_ctl) {
			kfree(cache);
			ret = -ENOMEM;
			goto error;
		}
C
Chris Mason 已提交
7072

7073
		atomic_set(&cache->count, 1);
7074
		spin_lock_init(&cache->lock);
J
Josef Bacik 已提交
7075
		cache->fs_info = info;
J
Josef Bacik 已提交
7076
		INIT_LIST_HEAD(&cache->list);
7077
		INIT_LIST_HEAD(&cache->cluster_list);
7078

7079 7080 7081
		if (need_clear)
			cache->disk_cache_state = BTRFS_DC_CLEAR;

7082 7083 7084
		read_extent_buffer(leaf, &cache->item,
				   btrfs_item_ptr_offset(leaf, path->slots[0]),
				   sizeof(cache->item));
C
Chris Mason 已提交
7085
		memcpy(&cache->key, &found_key, sizeof(found_key));
7086

C
Chris Mason 已提交
7087
		key.objectid = found_key.objectid + found_key.offset;
7088
		btrfs_release_path(path);
7089
		cache->flags = btrfs_block_group_flags(&cache->item);
J
Josef Bacik 已提交
7090 7091
		cache->sectorsize = root->sectorsize;

7092 7093
		btrfs_init_free_space_ctl(cache);

7094 7095 7096 7097 7098 7099 7100
		/*
		 * We need to exclude the super stripes now so that the space
		 * info has super bytes accounted for, otherwise we'll think
		 * we have more space than we actually do.
		 */
		exclude_super_stripes(root, cache);

J
Josef Bacik 已提交
7101 7102 7103 7104 7105 7106 7107 7108
		/*
		 * check for two cases, either we are full, and therefore
		 * don't need to bother with the caching work since we won't
		 * find any space, or we are empty, and we can just add all
		 * the space in and be done with it.  This saves us _alot_ of
		 * time, particularly in the full case.
		 */
		if (found_key.offset == btrfs_block_group_used(&cache->item)) {
7109
			cache->last_byte_to_unpin = (u64)-1;
J
Josef Bacik 已提交
7110
			cache->cached = BTRFS_CACHE_FINISHED;
7111
			free_excluded_extents(root, cache);
J
Josef Bacik 已提交
7112
		} else if (btrfs_block_group_used(&cache->item) == 0) {
7113
			cache->last_byte_to_unpin = (u64)-1;
J
Josef Bacik 已提交
7114 7115 7116 7117 7118
			cache->cached = BTRFS_CACHE_FINISHED;
			add_new_free_space(cache, root->fs_info,
					   found_key.objectid,
					   found_key.objectid +
					   found_key.offset);
7119
			free_excluded_extents(root, cache);
J
Josef Bacik 已提交
7120
		}
7121

7122 7123 7124 7125 7126
		ret = update_space_info(info, cache->flags, found_key.offset,
					btrfs_block_group_used(&cache->item),
					&space_info);
		BUG_ON(ret);
		cache->space_info = space_info;
7127
		spin_lock(&cache->space_info->lock);
7128
		cache->space_info->bytes_readonly += cache->bytes_super;
7129 7130
		spin_unlock(&cache->space_info->lock);

7131
		__link_block_group(space_info, cache);
J
Josef Bacik 已提交
7132 7133 7134

		ret = btrfs_add_block_group_cache(root->fs_info, cache);
		BUG_ON(ret);
7135 7136

		set_avail_alloc_bits(root->fs_info, cache->flags);
Y
Yan Zheng 已提交
7137
		if (btrfs_chunk_readonly(root, cache->key.objectid))
7138
			set_block_group_ro(cache, 1);
C
Chris Mason 已提交
7139
	}
7140 7141 7142 7143 7144 7145 7146 7147 7148 7149 7150 7151

	list_for_each_entry_rcu(space_info, &root->fs_info->space_info, list) {
		if (!(get_alloc_profile(root, space_info->flags) &
		      (BTRFS_BLOCK_GROUP_RAID10 |
		       BTRFS_BLOCK_GROUP_RAID1 |
		       BTRFS_BLOCK_GROUP_DUP)))
			continue;
		/*
		 * avoid allocating from un-mirrored block group if there are
		 * mirrored block groups.
		 */
		list_for_each_entry(cache, &space_info->block_groups[3], list)
7152
			set_block_group_ro(cache, 1);
7153
		list_for_each_entry(cache, &space_info->block_groups[4], list)
7154
			set_block_group_ro(cache, 1);
C
Chris Mason 已提交
7155
	}
7156 7157

	init_global_block_rsv(info);
7158 7159
	ret = 0;
error:
C
Chris Mason 已提交
7160
	btrfs_free_path(path);
7161
	return ret;
C
Chris Mason 已提交
7162
}
7163 7164 7165

int btrfs_make_block_group(struct btrfs_trans_handle *trans,
			   struct btrfs_root *root, u64 bytes_used,
7166
			   u64 type, u64 chunk_objectid, u64 chunk_offset,
7167 7168 7169 7170 7171 7172 7173 7174
			   u64 size)
{
	int ret;
	struct btrfs_root *extent_root;
	struct btrfs_block_group_cache *cache;

	extent_root = root->fs_info->extent_root;

7175
	root->fs_info->last_trans_log_full_commit = trans->transid;
7176

7177
	cache = kzalloc(sizeof(*cache), GFP_NOFS);
J
Josef Bacik 已提交
7178 7179
	if (!cache)
		return -ENOMEM;
7180 7181 7182 7183 7184 7185
	cache->free_space_ctl = kzalloc(sizeof(*cache->free_space_ctl),
					GFP_NOFS);
	if (!cache->free_space_ctl) {
		kfree(cache);
		return -ENOMEM;
	}
J
Josef Bacik 已提交
7186

7187
	cache->key.objectid = chunk_offset;
7188
	cache->key.offset = size;
7189
	cache->key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
7190
	cache->sectorsize = root->sectorsize;
7191
	cache->fs_info = root->fs_info;
7192

7193
	atomic_set(&cache->count, 1);
7194
	spin_lock_init(&cache->lock);
J
Josef Bacik 已提交
7195
	INIT_LIST_HEAD(&cache->list);
7196
	INIT_LIST_HEAD(&cache->cluster_list);
C
Chris Mason 已提交
7197

7198 7199
	btrfs_init_free_space_ctl(cache);

7200 7201 7202 7203 7204
	btrfs_set_block_group_used(&cache->item, bytes_used);
	btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
	cache->flags = type;
	btrfs_set_block_group_flags(&cache->item, type);

7205
	cache->last_byte_to_unpin = (u64)-1;
J
Josef Bacik 已提交
7206
	cache->cached = BTRFS_CACHE_FINISHED;
7207
	exclude_super_stripes(root, cache);
7208

J
Josef Bacik 已提交
7209 7210 7211
	add_new_free_space(cache, root->fs_info, chunk_offset,
			   chunk_offset + size);

7212 7213
	free_excluded_extents(root, cache);

7214 7215 7216
	ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
				&cache->space_info);
	BUG_ON(ret);
7217 7218

	spin_lock(&cache->space_info->lock);
7219
	cache->space_info->bytes_readonly += cache->bytes_super;
7220 7221
	spin_unlock(&cache->space_info->lock);

7222
	__link_block_group(cache->space_info, cache);
7223

J
Josef Bacik 已提交
7224 7225
	ret = btrfs_add_block_group_cache(root->fs_info, cache);
	BUG_ON(ret);
7226

7227 7228 7229 7230
	ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
				sizeof(cache->item));
	BUG_ON(ret);

C
Chris Mason 已提交
7231
	set_avail_alloc_bits(extent_root->fs_info, type);
7232

7233 7234
	return 0;
}
Z
Zheng Yan 已提交
7235 7236 7237 7238 7239 7240

int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
			     struct btrfs_root *root, u64 group_start)
{
	struct btrfs_path *path;
	struct btrfs_block_group_cache *block_group;
7241
	struct btrfs_free_cluster *cluster;
7242
	struct btrfs_root *tree_root = root->fs_info->tree_root;
Z
Zheng Yan 已提交
7243
	struct btrfs_key key;
7244
	struct inode *inode;
Z
Zheng Yan 已提交
7245
	int ret;
J
Josef Bacik 已提交
7246
	int factor;
Z
Zheng Yan 已提交
7247 7248 7249 7250 7251

	root = root->fs_info->extent_root;

	block_group = btrfs_lookup_block_group(root->fs_info, group_start);
	BUG_ON(!block_group);
Y
Yan Zheng 已提交
7252
	BUG_ON(!block_group->ro);
Z
Zheng Yan 已提交
7253

7254 7255 7256 7257 7258 7259
	/*
	 * Free the reserved super bytes from this block group before
	 * remove it.
	 */
	free_excluded_extents(root, block_group);

Z
Zheng Yan 已提交
7260
	memcpy(&key, &block_group->key, sizeof(key));
J
Josef Bacik 已提交
7261 7262 7263 7264 7265 7266
	if (block_group->flags & (BTRFS_BLOCK_GROUP_DUP |
				  BTRFS_BLOCK_GROUP_RAID1 |
				  BTRFS_BLOCK_GROUP_RAID10))
		factor = 2;
	else
		factor = 1;
Z
Zheng Yan 已提交
7267

7268 7269 7270 7271 7272 7273 7274 7275 7276 7277 7278 7279 7280 7281 7282
	/* make sure this block group isn't part of an allocation cluster */
	cluster = &root->fs_info->data_alloc_cluster;
	spin_lock(&cluster->refill_lock);
	btrfs_return_cluster_to_free_space(block_group, cluster);
	spin_unlock(&cluster->refill_lock);

	/*
	 * make sure this block group isn't part of a metadata
	 * allocation cluster
	 */
	cluster = &root->fs_info->meta_alloc_cluster;
	spin_lock(&cluster->refill_lock);
	btrfs_return_cluster_to_free_space(block_group, cluster);
	spin_unlock(&cluster->refill_lock);

Z
Zheng Yan 已提交
7283
	path = btrfs_alloc_path();
7284 7285 7286 7287
	if (!path) {
		ret = -ENOMEM;
		goto out;
	}
Z
Zheng Yan 已提交
7288

7289 7290
	inode = lookup_free_space_inode(root, block_group, path);
	if (!IS_ERR(inode)) {
7291 7292
		ret = btrfs_orphan_add(trans, inode);
		BUG_ON(ret);
7293 7294 7295 7296 7297 7298 7299 7300 7301 7302 7303 7304
		clear_nlink(inode);
		/* One for the block groups ref */
		spin_lock(&block_group->lock);
		if (block_group->iref) {
			block_group->iref = 0;
			block_group->inode = NULL;
			spin_unlock(&block_group->lock);
			iput(inode);
		} else {
			spin_unlock(&block_group->lock);
		}
		/* One for our lookup ref */
7305
		btrfs_add_delayed_iput(inode);
7306 7307 7308 7309 7310 7311 7312 7313 7314 7315
	}

	key.objectid = BTRFS_FREE_SPACE_OBJECTID;
	key.offset = block_group->key.objectid;
	key.type = 0;

	ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);
	if (ret < 0)
		goto out;
	if (ret > 0)
7316
		btrfs_release_path(path);
7317 7318 7319 7320
	if (ret == 0) {
		ret = btrfs_del_item(trans, tree_root, path);
		if (ret)
			goto out;
7321
		btrfs_release_path(path);
7322 7323
	}

7324
	spin_lock(&root->fs_info->block_group_cache_lock);
Z
Zheng Yan 已提交
7325 7326
	rb_erase(&block_group->cache_node,
		 &root->fs_info->block_group_cache_tree);
7327
	spin_unlock(&root->fs_info->block_group_cache_lock);
J
Josef Bacik 已提交
7328

7329
	down_write(&block_group->space_info->groups_sem);
7330 7331 7332 7333 7334
	/*
	 * we must use list_del_init so people can check to see if they
	 * are still on the list after taking the semaphore
	 */
	list_del_init(&block_group->list);
7335
	up_write(&block_group->space_info->groups_sem);
Z
Zheng Yan 已提交
7336

J
Josef Bacik 已提交
7337
	if (block_group->cached == BTRFS_CACHE_STARTED)
7338
		wait_block_group_cache_done(block_group);
J
Josef Bacik 已提交
7339 7340 7341

	btrfs_remove_free_space_cache(block_group);

Y
Yan Zheng 已提交
7342 7343 7344
	spin_lock(&block_group->space_info->lock);
	block_group->space_info->total_bytes -= block_group->key.offset;
	block_group->space_info->bytes_readonly -= block_group->key.offset;
J
Josef Bacik 已提交
7345
	block_group->space_info->disk_total -= block_group->key.offset * factor;
Y
Yan Zheng 已提交
7346
	spin_unlock(&block_group->space_info->lock);
7347

7348 7349
	memcpy(&key, &block_group->key, sizeof(key));

7350
	btrfs_clear_space_info_full(root->fs_info);
Y
Yan Zheng 已提交
7351

7352 7353
	btrfs_put_block_group(block_group);
	btrfs_put_block_group(block_group);
Z
Zheng Yan 已提交
7354 7355 7356 7357 7358 7359 7360 7361 7362 7363 7364 7365

	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
	if (ret > 0)
		ret = -EIO;
	if (ret < 0)
		goto out;

	ret = btrfs_del_item(trans, root, path);
out:
	btrfs_free_path(path);
	return ret;
}
L
liubo 已提交
7366

7367 7368 7369
int btrfs_init_space_info(struct btrfs_fs_info *fs_info)
{
	struct btrfs_space_info *space_info;
7370 7371 7372 7373
	struct btrfs_super_block *disk_super;
	u64 features;
	u64 flags;
	int mixed = 0;
7374 7375
	int ret;

7376 7377 7378
	disk_super = &fs_info->super_copy;
	if (!btrfs_super_root(disk_super))
		return 1;
7379

7380 7381 7382
	features = btrfs_super_incompat_flags(disk_super);
	if (features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
		mixed = 1;
7383

7384 7385
	flags = BTRFS_BLOCK_GROUP_SYSTEM;
	ret = update_space_info(fs_info, flags, 0, 0, &space_info);
7386
	if (ret)
7387
		goto out;
7388

7389 7390 7391 7392 7393 7394 7395 7396 7397 7398 7399 7400 7401
	if (mixed) {
		flags = BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA;
		ret = update_space_info(fs_info, flags, 0, 0, &space_info);
	} else {
		flags = BTRFS_BLOCK_GROUP_METADATA;
		ret = update_space_info(fs_info, flags, 0, 0, &space_info);
		if (ret)
			goto out;

		flags = BTRFS_BLOCK_GROUP_DATA;
		ret = update_space_info(fs_info, flags, 0, 0, &space_info);
	}
out:
7402 7403 7404
	return ret;
}

L
liubo 已提交
7405 7406 7407 7408 7409 7410
int btrfs_error_unpin_extent_range(struct btrfs_root *root, u64 start, u64 end)
{
	return unpin_extent_range(root, start, end);
}

int btrfs_error_discard_extent(struct btrfs_root *root, u64 bytenr,
7411
			       u64 num_bytes, u64 *actual_bytes)
L
liubo 已提交
7412
{
7413
	return btrfs_discard_extent(root, bytenr, num_bytes, actual_bytes);
L
liubo 已提交
7414
}
7415 7416 7417 7418 7419 7420 7421 7422 7423 7424 7425 7426 7427 7428 7429 7430 7431 7432 7433 7434 7435 7436 7437 7438 7439 7440 7441 7442 7443 7444 7445 7446 7447 7448 7449 7450 7451 7452 7453 7454 7455 7456 7457 7458 7459 7460 7461 7462

int btrfs_trim_fs(struct btrfs_root *root, struct fstrim_range *range)
{
	struct btrfs_fs_info *fs_info = root->fs_info;
	struct btrfs_block_group_cache *cache = NULL;
	u64 group_trimmed;
	u64 start;
	u64 end;
	u64 trimmed = 0;
	int ret = 0;

	cache = btrfs_lookup_block_group(fs_info, range->start);

	while (cache) {
		if (cache->key.objectid >= (range->start + range->len)) {
			btrfs_put_block_group(cache);
			break;
		}

		start = max(range->start, cache->key.objectid);
		end = min(range->start + range->len,
				cache->key.objectid + cache->key.offset);

		if (end - start >= range->minlen) {
			if (!block_group_cache_done(cache)) {
				ret = cache_block_group(cache, NULL, root, 0);
				if (!ret)
					wait_block_group_cache_done(cache);
			}
			ret = btrfs_trim_block_group(cache,
						     &group_trimmed,
						     start,
						     end,
						     range->minlen);

			trimmed += group_trimmed;
			if (ret) {
				btrfs_put_block_group(cache);
				break;
			}
		}

		cache = next_block_group(fs_info->tree_root, cache);
	}

	range->len = trimmed;
	return ret;
}