file.c 63.3 KB
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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/fs.h>
#include <linux/pagemap.h>
#include <linux/highmem.h>
#include <linux/time.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/backing-dev.h>
#include <linux/mpage.h>
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#include <linux/falloc.h>
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#include <linux/swap.h>
#include <linux/writeback.h>
#include <linux/statfs.h>
#include <linux/compat.h>
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#include <linux/slab.h>
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#include <linux/btrfs.h>
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#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
#include "btrfs_inode.h"
#include "print-tree.h"
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#include "tree-log.h"
#include "locking.h"
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#include "compat.h"
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#include "volumes.h"
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static struct kmem_cache *btrfs_inode_defrag_cachep;
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/*
 * when auto defrag is enabled we
 * queue up these defrag structs to remember which
 * inodes need defragging passes
 */
struct inode_defrag {
	struct rb_node rb_node;
	/* objectid */
	u64 ino;
	/*
	 * transid where the defrag was added, we search for
	 * extents newer than this
	 */
	u64 transid;

	/* root objectid */
	u64 root;

	/* last offset we were able to defrag */
	u64 last_offset;

	/* if we've wrapped around back to zero once already */
	int cycled;
};

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static int __compare_inode_defrag(struct inode_defrag *defrag1,
				  struct inode_defrag *defrag2)
{
	if (defrag1->root > defrag2->root)
		return 1;
	else if (defrag1->root < defrag2->root)
		return -1;
	else if (defrag1->ino > defrag2->ino)
		return 1;
	else if (defrag1->ino < defrag2->ino)
		return -1;
	else
		return 0;
}

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/* pop a record for an inode into the defrag tree.  The lock
 * must be held already
 *
 * If you're inserting a record for an older transid than an
 * existing record, the transid already in the tree is lowered
 *
 * If an existing record is found the defrag item you
 * pass in is freed
 */
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static int __btrfs_add_inode_defrag(struct inode *inode,
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				    struct inode_defrag *defrag)
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct inode_defrag *entry;
	struct rb_node **p;
	struct rb_node *parent = NULL;
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	int ret;
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	p = &root->fs_info->defrag_inodes.rb_node;
	while (*p) {
		parent = *p;
		entry = rb_entry(parent, struct inode_defrag, rb_node);

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		ret = __compare_inode_defrag(defrag, entry);
		if (ret < 0)
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			p = &parent->rb_left;
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		else if (ret > 0)
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			p = &parent->rb_right;
		else {
			/* if we're reinserting an entry for
			 * an old defrag run, make sure to
			 * lower the transid of our existing record
			 */
			if (defrag->transid < entry->transid)
				entry->transid = defrag->transid;
			if (defrag->last_offset > entry->last_offset)
				entry->last_offset = defrag->last_offset;
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			return -EEXIST;
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		}
	}
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	set_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags);
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	rb_link_node(&defrag->rb_node, parent, p);
	rb_insert_color(&defrag->rb_node, &root->fs_info->defrag_inodes);
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	return 0;
}
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static inline int __need_auto_defrag(struct btrfs_root *root)
{
	if (!btrfs_test_opt(root, AUTO_DEFRAG))
		return 0;

	if (btrfs_fs_closing(root->fs_info))
		return 0;
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	return 1;
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}

/*
 * insert a defrag record for this inode if auto defrag is
 * enabled
 */
int btrfs_add_inode_defrag(struct btrfs_trans_handle *trans,
			   struct inode *inode)
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct inode_defrag *defrag;
	u64 transid;
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	int ret;
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	if (!__need_auto_defrag(root))
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		return 0;

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	if (test_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags))
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		return 0;

	if (trans)
		transid = trans->transid;
	else
		transid = BTRFS_I(inode)->root->last_trans;

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	defrag = kmem_cache_zalloc(btrfs_inode_defrag_cachep, GFP_NOFS);
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	if (!defrag)
		return -ENOMEM;

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	defrag->ino = btrfs_ino(inode);
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	defrag->transid = transid;
	defrag->root = root->root_key.objectid;

	spin_lock(&root->fs_info->defrag_inodes_lock);
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	if (!test_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags)) {
		/*
		 * If we set IN_DEFRAG flag and evict the inode from memory,
		 * and then re-read this inode, this new inode doesn't have
		 * IN_DEFRAG flag. At the case, we may find the existed defrag.
		 */
		ret = __btrfs_add_inode_defrag(inode, defrag);
		if (ret)
			kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
	} else {
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		kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
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	}
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	spin_unlock(&root->fs_info->defrag_inodes_lock);
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	return 0;
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}

/*
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 * Requeue the defrag object. If there is a defrag object that points to
 * the same inode in the tree, we will merge them together (by
 * __btrfs_add_inode_defrag()) and free the one that we want to requeue.
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 */
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void btrfs_requeue_inode_defrag(struct inode *inode,
				struct inode_defrag *defrag)
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
	int ret;

	if (!__need_auto_defrag(root))
		goto out;

	/*
	 * Here we don't check the IN_DEFRAG flag, because we need merge
	 * them together.
	 */
	spin_lock(&root->fs_info->defrag_inodes_lock);
	ret = __btrfs_add_inode_defrag(inode, defrag);
	spin_unlock(&root->fs_info->defrag_inodes_lock);
	if (ret)
		goto out;
	return;
out:
	kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
}

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/*
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 * pick the defragable inode that we want, if it doesn't exist, we will get
 * the next one.
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 */
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static struct inode_defrag *
btrfs_pick_defrag_inode(struct btrfs_fs_info *fs_info, u64 root, u64 ino)
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{
	struct inode_defrag *entry = NULL;
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	struct inode_defrag tmp;
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	struct rb_node *p;
	struct rb_node *parent = NULL;
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	int ret;

	tmp.ino = ino;
	tmp.root = root;
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	spin_lock(&fs_info->defrag_inodes_lock);
	p = fs_info->defrag_inodes.rb_node;
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	while (p) {
		parent = p;
		entry = rb_entry(parent, struct inode_defrag, rb_node);

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		ret = __compare_inode_defrag(&tmp, entry);
		if (ret < 0)
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			p = parent->rb_left;
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		else if (ret > 0)
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			p = parent->rb_right;
		else
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			goto out;
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	}

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	if (parent && __compare_inode_defrag(&tmp, entry) > 0) {
		parent = rb_next(parent);
		if (parent)
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			entry = rb_entry(parent, struct inode_defrag, rb_node);
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		else
			entry = NULL;
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	}
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out:
	if (entry)
		rb_erase(parent, &fs_info->defrag_inodes);
	spin_unlock(&fs_info->defrag_inodes_lock);
	return entry;
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}

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void btrfs_cleanup_defrag_inodes(struct btrfs_fs_info *fs_info)
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{
	struct inode_defrag *defrag;
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	struct rb_node *node;

	spin_lock(&fs_info->defrag_inodes_lock);
	node = rb_first(&fs_info->defrag_inodes);
	while (node) {
		rb_erase(node, &fs_info->defrag_inodes);
		defrag = rb_entry(node, struct inode_defrag, rb_node);
		kmem_cache_free(btrfs_inode_defrag_cachep, defrag);

		if (need_resched()) {
			spin_unlock(&fs_info->defrag_inodes_lock);
			cond_resched();
			spin_lock(&fs_info->defrag_inodes_lock);
		}

		node = rb_first(&fs_info->defrag_inodes);
	}
	spin_unlock(&fs_info->defrag_inodes_lock);
}

#define BTRFS_DEFRAG_BATCH	1024

static int __btrfs_run_defrag_inode(struct btrfs_fs_info *fs_info,
				    struct inode_defrag *defrag)
{
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	struct btrfs_root *inode_root;
	struct inode *inode;
	struct btrfs_key key;
	struct btrfs_ioctl_defrag_range_args range;
	int num_defrag;
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	int index;
	int ret;
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	/* get the inode */
	key.objectid = defrag->root;
	btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
	key.offset = (u64)-1;
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	index = srcu_read_lock(&fs_info->subvol_srcu);

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	inode_root = btrfs_read_fs_root_no_name(fs_info, &key);
	if (IS_ERR(inode_root)) {
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		ret = PTR_ERR(inode_root);
		goto cleanup;
	}
	if (btrfs_root_refs(&inode_root->root_item) == 0) {
		ret = -ENOENT;
		goto cleanup;
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	}

	key.objectid = defrag->ino;
	btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
	key.offset = 0;
	inode = btrfs_iget(fs_info->sb, &key, inode_root, NULL);
	if (IS_ERR(inode)) {
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		ret = PTR_ERR(inode);
		goto cleanup;
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	}
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	srcu_read_unlock(&fs_info->subvol_srcu, index);
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	/* do a chunk of defrag */
	clear_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags);
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	memset(&range, 0, sizeof(range));
	range.len = (u64)-1;
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	range.start = defrag->last_offset;
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	sb_start_write(fs_info->sb);
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	num_defrag = btrfs_defrag_file(inode, NULL, &range, defrag->transid,
				       BTRFS_DEFRAG_BATCH);
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	sb_end_write(fs_info->sb);
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	/*
	 * if we filled the whole defrag batch, there
	 * must be more work to do.  Queue this defrag
	 * again
	 */
	if (num_defrag == BTRFS_DEFRAG_BATCH) {
		defrag->last_offset = range.start;
		btrfs_requeue_inode_defrag(inode, defrag);
	} else if (defrag->last_offset && !defrag->cycled) {
		/*
		 * we didn't fill our defrag batch, but
		 * we didn't start at zero.  Make sure we loop
		 * around to the start of the file.
		 */
		defrag->last_offset = 0;
		defrag->cycled = 1;
		btrfs_requeue_inode_defrag(inode, defrag);
	} else {
		kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
	}

	iput(inode);
	return 0;
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cleanup:
	srcu_read_unlock(&fs_info->subvol_srcu, index);
	kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
	return ret;
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}

/*
 * run through the list of inodes in the FS that need
 * defragging
 */
int btrfs_run_defrag_inodes(struct btrfs_fs_info *fs_info)
{
	struct inode_defrag *defrag;
	u64 first_ino = 0;
	u64 root_objectid = 0;
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	atomic_inc(&fs_info->defrag_running);
	while(1) {
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		if (!__need_auto_defrag(fs_info->tree_root))
			break;
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		/* find an inode to defrag */
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		defrag = btrfs_pick_defrag_inode(fs_info, root_objectid,
						 first_ino);
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		if (!defrag) {
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			if (root_objectid || first_ino) {
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				root_objectid = 0;
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				first_ino = 0;
				continue;
			} else {
				break;
			}
		}

		first_ino = defrag->ino + 1;
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		root_objectid = defrag->root;
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		__btrfs_run_defrag_inode(fs_info, defrag);
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	}
	atomic_dec(&fs_info->defrag_running);

	/*
	 * during unmount, we use the transaction_wait queue to
	 * wait for the defragger to stop
	 */
	wake_up(&fs_info->transaction_wait);
	return 0;
}
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/* simple helper to fault in pages and copy.  This should go away
 * and be replaced with calls into generic code.
 */
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static noinline int btrfs_copy_from_user(loff_t pos, int num_pages,
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					 size_t write_bytes,
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					 struct page **prepared_pages,
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					 struct iov_iter *i)
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{
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	size_t copied = 0;
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	size_t total_copied = 0;
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	int pg = 0;
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	int offset = pos & (PAGE_CACHE_SIZE - 1);

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	while (write_bytes > 0) {
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		size_t count = min_t(size_t,
				     PAGE_CACHE_SIZE - offset, write_bytes);
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		struct page *page = prepared_pages[pg];
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		/*
		 * Copy data from userspace to the current page
		 *
		 * Disable pagefault to avoid recursive lock since
		 * the pages are already locked
		 */
		pagefault_disable();
		copied = iov_iter_copy_from_user_atomic(page, i, offset, count);
		pagefault_enable();
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		/* Flush processor's dcache for this page */
		flush_dcache_page(page);
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		/*
		 * if we get a partial write, we can end up with
		 * partially up to date pages.  These add
		 * a lot of complexity, so make sure they don't
		 * happen by forcing this copy to be retried.
		 *
		 * The rest of the btrfs_file_write code will fall
		 * back to page at a time copies after we return 0.
		 */
		if (!PageUptodate(page) && copied < count)
			copied = 0;

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		iov_iter_advance(i, copied);
		write_bytes -= copied;
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		total_copied += copied;
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		/* Return to btrfs_file_aio_write to fault page */
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		if (unlikely(copied == 0))
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			break;
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		if (unlikely(copied < PAGE_CACHE_SIZE - offset)) {
			offset += copied;
		} else {
			pg++;
			offset = 0;
		}
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	}
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	return total_copied;
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}

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/*
 * unlocks pages after btrfs_file_write is done with them
 */
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void btrfs_drop_pages(struct page **pages, size_t num_pages)
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{
	size_t i;
	for (i = 0; i < num_pages; i++) {
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		/* page checked is some magic around finding pages that
		 * have been modified without going through btrfs_set_page_dirty
		 * clear it here
		 */
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		ClearPageChecked(pages[i]);
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		unlock_page(pages[i]);
		mark_page_accessed(pages[i]);
		page_cache_release(pages[i]);
	}
}

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/*
 * after copy_from_user, pages need to be dirtied and we need to make
 * sure holes are created between the current EOF and the start of
 * any next extents (if required).
 *
 * this also makes the decision about creating an inline extent vs
 * doing real data extents, marking pages dirty and delalloc as required.
 */
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int btrfs_dirty_pages(struct btrfs_root *root, struct inode *inode,
		      struct page **pages, size_t num_pages,
		      loff_t pos, size_t write_bytes,
		      struct extent_state **cached)
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{
	int err = 0;
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	int i;
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	u64 num_bytes;
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	u64 start_pos;
	u64 end_of_last_block;
	u64 end_pos = pos + write_bytes;
	loff_t isize = i_size_read(inode);
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	start_pos = pos & ~((u64)root->sectorsize - 1);
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	num_bytes = (write_bytes + pos - start_pos +
		    root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
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	end_of_last_block = start_pos + num_bytes - 1;
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	err = btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block,
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					cached);
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	if (err)
		return err;
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	for (i = 0; i < num_pages; i++) {
		struct page *p = pages[i];
		SetPageUptodate(p);
		ClearPageChecked(p);
		set_page_dirty(p);
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	}
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	/*
	 * we've only changed i_size in ram, and we haven't updated
	 * the disk i_size.  There is no need to log the inode
	 * at this time.
	 */
	if (end_pos > isize)
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		i_size_write(inode, end_pos);
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	return 0;
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}

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/*
 * this drops all the extents in the cache that intersect the range
 * [start, end].  Existing extents are split as required.
 */
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void btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end,
			     int skip_pinned)
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{
	struct extent_map *em;
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	struct extent_map *split = NULL;
	struct extent_map *split2 = NULL;
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	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
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	u64 len = end - start + 1;
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	u64 gen;
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	int ret;
	int testend = 1;
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	unsigned long flags;
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	int compressed = 0;
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	WARN_ON(end < start);
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	if (end == (u64)-1) {
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		len = (u64)-1;
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		testend = 0;
	}
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	while (1) {
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		int no_splits = 0;

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		if (!split)
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			split = alloc_extent_map();
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		if (!split2)
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			split2 = alloc_extent_map();
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		if (!split || !split2)
			no_splits = 1;
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		write_lock(&em_tree->lock);
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		em = lookup_extent_mapping(em_tree, start, len);
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		if (!em) {
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			write_unlock(&em_tree->lock);
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			break;
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		}
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		flags = em->flags;
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		gen = em->generation;
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		if (skip_pinned && test_bit(EXTENT_FLAG_PINNED, &em->flags)) {
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			if (testend && em->start + em->len >= start + len) {
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				free_extent_map(em);
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				write_unlock(&em_tree->lock);
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				break;
			}
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			start = em->start + em->len;
			if (testend)
583 584
				len = start + len - (em->start + em->len);
			free_extent_map(em);
C
Chris Mason 已提交
585
			write_unlock(&em_tree->lock);
586 587
			continue;
		}
C
Chris Mason 已提交
588
		compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
589
		clear_bit(EXTENT_FLAG_PINNED, &em->flags);
590
		remove_extent_mapping(em_tree, em);
591 592
		if (no_splits)
			goto next;
593 594 595 596 597

		if (em->block_start < EXTENT_MAP_LAST_BYTE &&
		    em->start < start) {
			split->start = em->start;
			split->len = start - em->start;
598
			split->orig_start = em->orig_start;
599
			split->block_start = em->block_start;
C
Chris Mason 已提交
600 601 602 603 604

			if (compressed)
				split->block_len = em->block_len;
			else
				split->block_len = split->len;
605 606
			split->orig_block_len = max(split->block_len,
						    em->orig_block_len);
J
Josef Bacik 已提交
607
			split->generation = gen;
608
			split->bdev = em->bdev;
609
			split->flags = flags;
610
			split->compress_type = em->compress_type;
611
			ret = add_extent_mapping(em_tree, split);
612
			BUG_ON(ret); /* Logic error */
J
Josef Bacik 已提交
613
			list_move(&split->list, &em_tree->modified_extents);
614 615 616 617 618 619 620 621 622 623 624
			free_extent_map(split);
			split = split2;
			split2 = NULL;
		}
		if (em->block_start < EXTENT_MAP_LAST_BYTE &&
		    testend && em->start + em->len > start + len) {
			u64 diff = start + len - em->start;

			split->start = start + len;
			split->len = em->start + em->len - (start + len);
			split->bdev = em->bdev;
625
			split->flags = flags;
626
			split->compress_type = em->compress_type;
J
Josef Bacik 已提交
627
			split->generation = gen;
628 629
			split->orig_block_len = max(em->block_len,
						    em->orig_block_len);
630

C
Chris Mason 已提交
631 632 633
			if (compressed) {
				split->block_len = em->block_len;
				split->block_start = em->block_start;
634
				split->orig_start = em->orig_start;
C
Chris Mason 已提交
635 636 637
			} else {
				split->block_len = split->len;
				split->block_start = em->block_start + diff;
638
				split->orig_start = em->orig_start;
C
Chris Mason 已提交
639
			}
640 641

			ret = add_extent_mapping(em_tree, split);
642
			BUG_ON(ret); /* Logic error */
J
Josef Bacik 已提交
643
			list_move(&split->list, &em_tree->modified_extents);
644 645 646
			free_extent_map(split);
			split = NULL;
		}
647
next:
648
		write_unlock(&em_tree->lock);
649

650 651 652 653 654
		/* once for us */
		free_extent_map(em);
		/* once for the tree*/
		free_extent_map(em);
	}
655 656 657 658
	if (split)
		free_extent_map(split);
	if (split2)
		free_extent_map(split2);
659 660
}

C
Chris Mason 已提交
661 662 663 664 665 666 667 668 669
/*
 * this is very complex, but the basic idea is to drop all extents
 * in the range start - end.  hint_block is filled in with a block number
 * that would be a good hint to the block allocator for this file.
 *
 * If an extent intersects the range but is not entirely inside the range
 * it is either truncated or split.  Anything entirely inside the range
 * is deleted from the tree.
 */
J
Josef Bacik 已提交
670 671 672
int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
			 struct btrfs_root *root, struct inode *inode,
			 struct btrfs_path *path, u64 start, u64 end,
J
Josef Bacik 已提交
673
			 u64 *drop_end, int drop_cache)
C
Chris Mason 已提交
674
{
675
	struct extent_buffer *leaf;
Y
Yan, Zheng 已提交
676
	struct btrfs_file_extent_item *fi;
677
	struct btrfs_key key;
Y
Yan, Zheng 已提交
678
	struct btrfs_key new_key;
L
Li Zefan 已提交
679
	u64 ino = btrfs_ino(inode);
Y
Yan, Zheng 已提交
680 681 682 683 684 685 686 687
	u64 search_start = start;
	u64 disk_bytenr = 0;
	u64 num_bytes = 0;
	u64 extent_offset = 0;
	u64 extent_end = 0;
	int del_nr = 0;
	int del_slot = 0;
	int extent_type;
C
Chris Mason 已提交
688
	int recow;
689
	int ret;
690
	int modify_tree = -1;
J
Josef Bacik 已提交
691
	int update_refs = (root->ref_cows || root == root->fs_info->tree_root);
692
	int found = 0;
C
Chris Mason 已提交
693

C
Chris Mason 已提交
694 695
	if (drop_cache)
		btrfs_drop_extent_cache(inode, start, end - 1, 0);
696

697 698 699
	if (start >= BTRFS_I(inode)->disk_i_size)
		modify_tree = 0;

C
Chris Mason 已提交
700
	while (1) {
C
Chris Mason 已提交
701
		recow = 0;
L
Li Zefan 已提交
702
		ret = btrfs_lookup_file_extent(trans, root, path, ino,
703
					       search_start, modify_tree);
C
Chris Mason 已提交
704
		if (ret < 0)
Y
Yan, Zheng 已提交
705 706 707 708
			break;
		if (ret > 0 && path->slots[0] > 0 && search_start == start) {
			leaf = path->nodes[0];
			btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
L
Li Zefan 已提交
709
			if (key.objectid == ino &&
Y
Yan, Zheng 已提交
710 711
			    key.type == BTRFS_EXTENT_DATA_KEY)
				path->slots[0]--;
C
Chris Mason 已提交
712
		}
Y
Yan, Zheng 已提交
713
		ret = 0;
714
next_slot:
715
		leaf = path->nodes[0];
Y
Yan, Zheng 已提交
716 717 718 719 720 721 722 723
		if (path->slots[0] >= btrfs_header_nritems(leaf)) {
			BUG_ON(del_nr > 0);
			ret = btrfs_next_leaf(root, path);
			if (ret < 0)
				break;
			if (ret > 0) {
				ret = 0;
				break;
724
			}
Y
Yan, Zheng 已提交
725 726 727 728 729
			leaf = path->nodes[0];
			recow = 1;
		}

		btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
L
Li Zefan 已提交
730
		if (key.objectid > ino ||
Y
Yan, Zheng 已提交
731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747
		    key.type > BTRFS_EXTENT_DATA_KEY || key.offset >= end)
			break;

		fi = btrfs_item_ptr(leaf, path->slots[0],
				    struct btrfs_file_extent_item);
		extent_type = btrfs_file_extent_type(leaf, fi);

		if (extent_type == BTRFS_FILE_EXTENT_REG ||
		    extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
			disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
			num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
			extent_offset = btrfs_file_extent_offset(leaf, fi);
			extent_end = key.offset +
				btrfs_file_extent_num_bytes(leaf, fi);
		} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
			extent_end = key.offset +
				btrfs_file_extent_inline_len(leaf, fi);
748
		} else {
Y
Yan, Zheng 已提交
749
			WARN_ON(1);
750
			extent_end = search_start;
C
Chris Mason 已提交
751 752
		}

Y
Yan, Zheng 已提交
753 754
		if (extent_end <= search_start) {
			path->slots[0]++;
755
			goto next_slot;
C
Chris Mason 已提交
756 757
		}

758
		found = 1;
Y
Yan, Zheng 已提交
759
		search_start = max(key.offset, start);
760 761
		if (recow || !modify_tree) {
			modify_tree = -1;
762
			btrfs_release_path(path);
Y
Yan, Zheng 已提交
763
			continue;
C
Chris Mason 已提交
764
		}
Y
Yan Zheng 已提交
765

Y
Yan, Zheng 已提交
766 767 768 769 770 771 772 773 774 775 776 777 778
		/*
		 *     | - range to drop - |
		 *  | -------- extent -------- |
		 */
		if (start > key.offset && end < extent_end) {
			BUG_ON(del_nr > 0);
			BUG_ON(extent_type == BTRFS_FILE_EXTENT_INLINE);

			memcpy(&new_key, &key, sizeof(new_key));
			new_key.offset = start;
			ret = btrfs_duplicate_item(trans, root, path,
						   &new_key);
			if (ret == -EAGAIN) {
779
				btrfs_release_path(path);
Y
Yan, Zheng 已提交
780
				continue;
Y
Yan Zheng 已提交
781
			}
Y
Yan, Zheng 已提交
782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799
			if (ret < 0)
				break;

			leaf = path->nodes[0];
			fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
					    struct btrfs_file_extent_item);
			btrfs_set_file_extent_num_bytes(leaf, fi,
							start - key.offset);

			fi = btrfs_item_ptr(leaf, path->slots[0],
					    struct btrfs_file_extent_item);

			extent_offset += start - key.offset;
			btrfs_set_file_extent_offset(leaf, fi, extent_offset);
			btrfs_set_file_extent_num_bytes(leaf, fi,
							extent_end - start);
			btrfs_mark_buffer_dirty(leaf);

J
Josef Bacik 已提交
800
			if (update_refs && disk_bytenr > 0) {
801
				ret = btrfs_inc_extent_ref(trans, root,
Y
Yan, Zheng 已提交
802 803 804
						disk_bytenr, num_bytes, 0,
						root->root_key.objectid,
						new_key.objectid,
A
Arne Jansen 已提交
805
						start - extent_offset, 0);
806
				BUG_ON(ret); /* -ENOMEM */
807
			}
Y
Yan, Zheng 已提交
808
			key.offset = start;
Y
Yan Zheng 已提交
809
		}
Y
Yan, Zheng 已提交
810 811 812 813 814 815
		/*
		 *  | ---- range to drop ----- |
		 *      | -------- extent -------- |
		 */
		if (start <= key.offset && end < extent_end) {
			BUG_ON(extent_type == BTRFS_FILE_EXTENT_INLINE);
Y
Yan Zheng 已提交
816

Y
Yan, Zheng 已提交
817 818 819
			memcpy(&new_key, &key, sizeof(new_key));
			new_key.offset = end;
			btrfs_set_item_key_safe(trans, root, path, &new_key);
Y
Yan Zheng 已提交
820

Y
Yan, Zheng 已提交
821 822 823 824 825
			extent_offset += end - key.offset;
			btrfs_set_file_extent_offset(leaf, fi, extent_offset);
			btrfs_set_file_extent_num_bytes(leaf, fi,
							extent_end - end);
			btrfs_mark_buffer_dirty(leaf);
826
			if (update_refs && disk_bytenr > 0)
Y
Yan, Zheng 已提交
827 828
				inode_sub_bytes(inode, end - key.offset);
			break;
C
Chris Mason 已提交
829
		}
830

Y
Yan, Zheng 已提交
831 832 833 834 835 836 837 838
		search_start = extent_end;
		/*
		 *       | ---- range to drop ----- |
		 *  | -------- extent -------- |
		 */
		if (start > key.offset && end >= extent_end) {
			BUG_ON(del_nr > 0);
			BUG_ON(extent_type == BTRFS_FILE_EXTENT_INLINE);
839

Y
Yan, Zheng 已提交
840 841 842
			btrfs_set_file_extent_num_bytes(leaf, fi,
							start - key.offset);
			btrfs_mark_buffer_dirty(leaf);
843
			if (update_refs && disk_bytenr > 0)
Y
Yan, Zheng 已提交
844 845 846
				inode_sub_bytes(inode, extent_end - start);
			if (end == extent_end)
				break;
C
Chris Mason 已提交
847

Y
Yan, Zheng 已提交
848 849
			path->slots[0]++;
			goto next_slot;
Z
Zheng Yan 已提交
850 851
		}

Y
Yan, Zheng 已提交
852 853 854 855 856 857 858 859 860 861 862 863
		/*
		 *  | ---- range to drop ----- |
		 *    | ------ extent ------ |
		 */
		if (start <= key.offset && end >= extent_end) {
			if (del_nr == 0) {
				del_slot = path->slots[0];
				del_nr = 1;
			} else {
				BUG_ON(del_slot + del_nr != path->slots[0]);
				del_nr++;
			}
Z
Zheng Yan 已提交
864

J
Josef Bacik 已提交
865 866
			if (update_refs &&
			    extent_type == BTRFS_FILE_EXTENT_INLINE) {
867
				inode_sub_bytes(inode,
Y
Yan, Zheng 已提交
868 869 870
						extent_end - key.offset);
				extent_end = ALIGN(extent_end,
						   root->sectorsize);
J
Josef Bacik 已提交
871
			} else if (update_refs && disk_bytenr > 0) {
Z
Zheng Yan 已提交
872
				ret = btrfs_free_extent(trans, root,
Y
Yan, Zheng 已提交
873 874
						disk_bytenr, num_bytes, 0,
						root->root_key.objectid,
875
						key.objectid, key.offset -
A
Arne Jansen 已提交
876
						extent_offset, 0);
877
				BUG_ON(ret); /* -ENOMEM */
Y
Yan, Zheng 已提交
878 879
				inode_sub_bytes(inode,
						extent_end - key.offset);
Z
Zheng Yan 已提交
880 881
			}

Y
Yan, Zheng 已提交
882 883 884 885 886 887 888 889 890 891
			if (end == extent_end)
				break;

			if (path->slots[0] + 1 < btrfs_header_nritems(leaf)) {
				path->slots[0]++;
				goto next_slot;
			}

			ret = btrfs_del_items(trans, root, path, del_slot,
					      del_nr);
892 893
			if (ret) {
				btrfs_abort_transaction(trans, root, ret);
J
Josef Bacik 已提交
894
				break;
895
			}
Y
Yan, Zheng 已提交
896 897 898 899

			del_nr = 0;
			del_slot = 0;

900
			btrfs_release_path(path);
Y
Yan, Zheng 已提交
901
			continue;
C
Chris Mason 已提交
902
		}
Y
Yan, Zheng 已提交
903 904

		BUG_ON(1);
C
Chris Mason 已提交
905
	}
Y
Yan, Zheng 已提交
906

907
	if (!ret && del_nr > 0) {
Y
Yan, Zheng 已提交
908
		ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
909 910
		if (ret)
			btrfs_abort_transaction(trans, root, ret);
Y
Yan Zheng 已提交
911
	}
Y
Yan, Zheng 已提交
912

J
Josef Bacik 已提交
913
	if (drop_end)
914
		*drop_end = found ? min(end, extent_end) : end;
J
Josef Bacik 已提交
915 916 917 918 919 920
	btrfs_release_path(path);
	return ret;
}

int btrfs_drop_extents(struct btrfs_trans_handle *trans,
		       struct btrfs_root *root, struct inode *inode, u64 start,
921
		       u64 end, int drop_cache)
J
Josef Bacik 已提交
922 923 924 925 926 927 928
{
	struct btrfs_path *path;
	int ret;

	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;
J
Josef Bacik 已提交
929
	ret = __btrfs_drop_extents(trans, root, inode, path, start, end, NULL,
930
				   drop_cache);
Y
Yan, Zheng 已提交
931
	btrfs_free_path(path);
C
Chris Mason 已提交
932 933 934
	return ret;
}

Y
Yan Zheng 已提交
935
static int extent_mergeable(struct extent_buffer *leaf, int slot,
936 937
			    u64 objectid, u64 bytenr, u64 orig_offset,
			    u64 *start, u64 *end)
Y
Yan Zheng 已提交
938 939 940 941 942 943 944 945 946 947 948 949 950 951 952
{
	struct btrfs_file_extent_item *fi;
	struct btrfs_key key;
	u64 extent_end;

	if (slot < 0 || slot >= btrfs_header_nritems(leaf))
		return 0;

	btrfs_item_key_to_cpu(leaf, &key, slot);
	if (key.objectid != objectid || key.type != BTRFS_EXTENT_DATA_KEY)
		return 0;

	fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
	if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG ||
	    btrfs_file_extent_disk_bytenr(leaf, fi) != bytenr ||
953
	    btrfs_file_extent_offset(leaf, fi) != key.offset - orig_offset ||
Y
Yan Zheng 已提交
954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977
	    btrfs_file_extent_compression(leaf, fi) ||
	    btrfs_file_extent_encryption(leaf, fi) ||
	    btrfs_file_extent_other_encoding(leaf, fi))
		return 0;

	extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
	if ((*start && *start != key.offset) || (*end && *end != extent_end))
		return 0;

	*start = key.offset;
	*end = extent_end;
	return 1;
}

/*
 * Mark extent in the range start - end as written.
 *
 * This changes extent type from 'pre-allocated' to 'regular'. If only
 * part of extent is marked as written, the extent will be split into
 * two or three.
 */
int btrfs_mark_extent_written(struct btrfs_trans_handle *trans,
			      struct inode *inode, u64 start, u64 end)
{
Y
Yan, Zheng 已提交
978
	struct btrfs_root *root = BTRFS_I(inode)->root;
Y
Yan Zheng 已提交
979 980 981 982
	struct extent_buffer *leaf;
	struct btrfs_path *path;
	struct btrfs_file_extent_item *fi;
	struct btrfs_key key;
Y
Yan, Zheng 已提交
983
	struct btrfs_key new_key;
Y
Yan Zheng 已提交
984 985 986
	u64 bytenr;
	u64 num_bytes;
	u64 extent_end;
987
	u64 orig_offset;
Y
Yan Zheng 已提交
988 989
	u64 other_start;
	u64 other_end;
Y
Yan, Zheng 已提交
990 991 992
	u64 split;
	int del_nr = 0;
	int del_slot = 0;
993
	int recow;
Y
Yan Zheng 已提交
994
	int ret;
L
Li Zefan 已提交
995
	u64 ino = btrfs_ino(inode);
Y
Yan Zheng 已提交
996 997

	path = btrfs_alloc_path();
998 999
	if (!path)
		return -ENOMEM;
Y
Yan Zheng 已提交
1000
again:
1001
	recow = 0;
Y
Yan, Zheng 已提交
1002
	split = start;
L
Li Zefan 已提交
1003
	key.objectid = ino;
Y
Yan Zheng 已提交
1004
	key.type = BTRFS_EXTENT_DATA_KEY;
Y
Yan, Zheng 已提交
1005
	key.offset = split;
Y
Yan Zheng 已提交
1006 1007

	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1008 1009
	if (ret < 0)
		goto out;
Y
Yan Zheng 已提交
1010 1011 1012 1013 1014
	if (ret > 0 && path->slots[0] > 0)
		path->slots[0]--;

	leaf = path->nodes[0];
	btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
L
Li Zefan 已提交
1015
	BUG_ON(key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY);
Y
Yan Zheng 已提交
1016 1017
	fi = btrfs_item_ptr(leaf, path->slots[0],
			    struct btrfs_file_extent_item);
Y
Yan, Zheng 已提交
1018 1019
	BUG_ON(btrfs_file_extent_type(leaf, fi) !=
	       BTRFS_FILE_EXTENT_PREALLOC);
Y
Yan Zheng 已提交
1020 1021 1022 1023 1024
	extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
	BUG_ON(key.offset > start || extent_end < end);

	bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
	num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
1025
	orig_offset = key.offset - btrfs_file_extent_offset(leaf, fi);
1026 1027 1028 1029 1030 1031
	memcpy(&new_key, &key, sizeof(new_key));

	if (start == key.offset && end < extent_end) {
		other_start = 0;
		other_end = start;
		if (extent_mergeable(leaf, path->slots[0] - 1,
L
Li Zefan 已提交
1032
				     ino, bytenr, orig_offset,
1033 1034 1035 1036 1037
				     &other_start, &other_end)) {
			new_key.offset = end;
			btrfs_set_item_key_safe(trans, root, path, &new_key);
			fi = btrfs_item_ptr(leaf, path->slots[0],
					    struct btrfs_file_extent_item);
1038 1039
			btrfs_set_file_extent_generation(leaf, fi,
							 trans->transid);
1040 1041 1042 1043 1044 1045
			btrfs_set_file_extent_num_bytes(leaf, fi,
							extent_end - end);
			btrfs_set_file_extent_offset(leaf, fi,
						     end - orig_offset);
			fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
					    struct btrfs_file_extent_item);
1046 1047
			btrfs_set_file_extent_generation(leaf, fi,
							 trans->transid);
1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058
			btrfs_set_file_extent_num_bytes(leaf, fi,
							end - other_start);
			btrfs_mark_buffer_dirty(leaf);
			goto out;
		}
	}

	if (start > key.offset && end == extent_end) {
		other_start = end;
		other_end = 0;
		if (extent_mergeable(leaf, path->slots[0] + 1,
L
Li Zefan 已提交
1059
				     ino, bytenr, orig_offset,
1060 1061 1062 1063 1064
				     &other_start, &other_end)) {
			fi = btrfs_item_ptr(leaf, path->slots[0],
					    struct btrfs_file_extent_item);
			btrfs_set_file_extent_num_bytes(leaf, fi,
							start - key.offset);
1065 1066
			btrfs_set_file_extent_generation(leaf, fi,
							 trans->transid);
1067 1068 1069 1070 1071 1072
			path->slots[0]++;
			new_key.offset = start;
			btrfs_set_item_key_safe(trans, root, path, &new_key);

			fi = btrfs_item_ptr(leaf, path->slots[0],
					    struct btrfs_file_extent_item);
1073 1074
			btrfs_set_file_extent_generation(leaf, fi,
							 trans->transid);
1075 1076 1077 1078 1079 1080 1081 1082
			btrfs_set_file_extent_num_bytes(leaf, fi,
							other_end - start);
			btrfs_set_file_extent_offset(leaf, fi,
						     start - orig_offset);
			btrfs_mark_buffer_dirty(leaf);
			goto out;
		}
	}
Y
Yan Zheng 已提交
1083

Y
Yan, Zheng 已提交
1084 1085 1086 1087 1088 1089 1090
	while (start > key.offset || end < extent_end) {
		if (key.offset == start)
			split = end;

		new_key.offset = split;
		ret = btrfs_duplicate_item(trans, root, path, &new_key);
		if (ret == -EAGAIN) {
1091
			btrfs_release_path(path);
Y
Yan, Zheng 已提交
1092
			goto again;
Y
Yan Zheng 已提交
1093
		}
1094 1095 1096 1097
		if (ret < 0) {
			btrfs_abort_transaction(trans, root, ret);
			goto out;
		}
Y
Yan Zheng 已提交
1098

Y
Yan, Zheng 已提交
1099 1100
		leaf = path->nodes[0];
		fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
Y
Yan Zheng 已提交
1101
				    struct btrfs_file_extent_item);
1102
		btrfs_set_file_extent_generation(leaf, fi, trans->transid);
Y
Yan Zheng 已提交
1103
		btrfs_set_file_extent_num_bytes(leaf, fi,
Y
Yan, Zheng 已提交
1104 1105 1106 1107 1108
						split - key.offset);

		fi = btrfs_item_ptr(leaf, path->slots[0],
				    struct btrfs_file_extent_item);

1109
		btrfs_set_file_extent_generation(leaf, fi, trans->transid);
Y
Yan, Zheng 已提交
1110 1111 1112
		btrfs_set_file_extent_offset(leaf, fi, split - orig_offset);
		btrfs_set_file_extent_num_bytes(leaf, fi,
						extent_end - split);
Y
Yan Zheng 已提交
1113 1114
		btrfs_mark_buffer_dirty(leaf);

Y
Yan, Zheng 已提交
1115 1116
		ret = btrfs_inc_extent_ref(trans, root, bytenr, num_bytes, 0,
					   root->root_key.objectid,
A
Arne Jansen 已提交
1117
					   ino, orig_offset, 0);
1118
		BUG_ON(ret); /* -ENOMEM */
Y
Yan Zheng 已提交
1119

Y
Yan, Zheng 已提交
1120 1121 1122 1123
		if (split == start) {
			key.offset = start;
		} else {
			BUG_ON(start != key.offset);
Y
Yan Zheng 已提交
1124
			path->slots[0]--;
Y
Yan, Zheng 已提交
1125
			extent_end = end;
Y
Yan Zheng 已提交
1126
		}
1127
		recow = 1;
Y
Yan Zheng 已提交
1128 1129
	}

Y
Yan, Zheng 已提交
1130 1131
	other_start = end;
	other_end = 0;
1132
	if (extent_mergeable(leaf, path->slots[0] + 1,
L
Li Zefan 已提交
1133
			     ino, bytenr, orig_offset,
1134 1135
			     &other_start, &other_end)) {
		if (recow) {
1136
			btrfs_release_path(path);
1137 1138
			goto again;
		}
Y
Yan, Zheng 已提交
1139 1140 1141 1142 1143
		extent_end = other_end;
		del_slot = path->slots[0] + 1;
		del_nr++;
		ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
					0, root->root_key.objectid,
A
Arne Jansen 已提交
1144
					ino, orig_offset, 0);
1145
		BUG_ON(ret); /* -ENOMEM */
Y
Yan Zheng 已提交
1146
	}
Y
Yan, Zheng 已提交
1147 1148
	other_start = 0;
	other_end = start;
1149
	if (extent_mergeable(leaf, path->slots[0] - 1,
L
Li Zefan 已提交
1150
			     ino, bytenr, orig_offset,
1151 1152
			     &other_start, &other_end)) {
		if (recow) {
1153
			btrfs_release_path(path);
1154 1155
			goto again;
		}
Y
Yan, Zheng 已提交
1156 1157 1158 1159 1160
		key.offset = other_start;
		del_slot = path->slots[0];
		del_nr++;
		ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
					0, root->root_key.objectid,
A
Arne Jansen 已提交
1161
					ino, orig_offset, 0);
1162
		BUG_ON(ret); /* -ENOMEM */
Y
Yan, Zheng 已提交
1163 1164
	}
	if (del_nr == 0) {
1165 1166
		fi = btrfs_item_ptr(leaf, path->slots[0],
			   struct btrfs_file_extent_item);
Y
Yan, Zheng 已提交
1167 1168
		btrfs_set_file_extent_type(leaf, fi,
					   BTRFS_FILE_EXTENT_REG);
1169
		btrfs_set_file_extent_generation(leaf, fi, trans->transid);
Y
Yan, Zheng 已提交
1170
		btrfs_mark_buffer_dirty(leaf);
1171
	} else {
1172 1173
		fi = btrfs_item_ptr(leaf, del_slot - 1,
			   struct btrfs_file_extent_item);
1174 1175
		btrfs_set_file_extent_type(leaf, fi,
					   BTRFS_FILE_EXTENT_REG);
1176
		btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1177 1178 1179
		btrfs_set_file_extent_num_bytes(leaf, fi,
						extent_end - key.offset);
		btrfs_mark_buffer_dirty(leaf);
Y
Yan, Zheng 已提交
1180

1181
		ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
1182 1183 1184 1185
		if (ret < 0) {
			btrfs_abort_transaction(trans, root, ret);
			goto out;
		}
1186
	}
Y
Yan, Zheng 已提交
1187
out:
Y
Yan Zheng 已提交
1188 1189 1190 1191
	btrfs_free_path(path);
	return 0;
}

1192 1193 1194 1195
/*
 * on error we return an unlocked page and the error value
 * on success we return a locked page and 0
 */
1196 1197
static int prepare_uptodate_page(struct page *page, u64 pos,
				 bool force_uptodate)
1198 1199 1200
{
	int ret = 0;

1201 1202
	if (((pos & (PAGE_CACHE_SIZE - 1)) || force_uptodate) &&
	    !PageUptodate(page)) {
1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214
		ret = btrfs_readpage(NULL, page);
		if (ret)
			return ret;
		lock_page(page);
		if (!PageUptodate(page)) {
			unlock_page(page);
			return -EIO;
		}
	}
	return 0;
}

C
Chris Mason 已提交
1215
/*
C
Chris Mason 已提交
1216 1217 1218
 * this gets pages into the page cache and locks them down, it also properly
 * waits for data=ordered extents to finish before allowing the pages to be
 * modified.
C
Chris Mason 已提交
1219
 */
C
Chris Mason 已提交
1220
static noinline int prepare_pages(struct btrfs_root *root, struct file *file,
1221 1222
			 struct page **pages, size_t num_pages,
			 loff_t pos, unsigned long first_index,
1223
			 size_t write_bytes, bool force_uptodate)
C
Chris Mason 已提交
1224
{
1225
	struct extent_state *cached_state = NULL;
C
Chris Mason 已提交
1226 1227
	int i;
	unsigned long index = pos >> PAGE_CACHE_SHIFT;
1228
	struct inode *inode = fdentry(file)->d_inode;
1229
	gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
C
Chris Mason 已提交
1230
	int err = 0;
1231
	int faili = 0;
1232
	u64 start_pos;
1233
	u64 last_pos;
1234

1235
	start_pos = pos & ~((u64)root->sectorsize - 1);
1236
	last_pos = ((u64)index + num_pages) << PAGE_CACHE_SHIFT;
C
Chris Mason 已提交
1237

1238
again:
C
Chris Mason 已提交
1239
	for (i = 0; i < num_pages; i++) {
1240
		pages[i] = find_or_create_page(inode->i_mapping, index + i,
1241
					       mask | __GFP_WRITE);
C
Chris Mason 已提交
1242
		if (!pages[i]) {
1243 1244 1245 1246 1247 1248
			faili = i - 1;
			err = -ENOMEM;
			goto fail;
		}

		if (i == 0)
1249 1250
			err = prepare_uptodate_page(pages[i], pos,
						    force_uptodate);
1251 1252
		if (i == num_pages - 1)
			err = prepare_uptodate_page(pages[i],
1253
						    pos + write_bytes, false);
1254 1255 1256 1257
		if (err) {
			page_cache_release(pages[i]);
			faili = i - 1;
			goto fail;
C
Chris Mason 已提交
1258
		}
C
Chris Mason 已提交
1259
		wait_on_page_writeback(pages[i]);
C
Chris Mason 已提交
1260
	}
1261
	err = 0;
1262
	if (start_pos < inode->i_size) {
1263
		struct btrfs_ordered_extent *ordered;
1264
		lock_extent_bits(&BTRFS_I(inode)->io_tree,
1265
				 start_pos, last_pos - 1, 0, &cached_state);
C
Chris Mason 已提交
1266 1267
		ordered = btrfs_lookup_first_ordered_extent(inode,
							    last_pos - 1);
1268 1269 1270 1271
		if (ordered &&
		    ordered->file_offset + ordered->len > start_pos &&
		    ordered->file_offset < last_pos) {
			btrfs_put_ordered_extent(ordered);
1272 1273 1274
			unlock_extent_cached(&BTRFS_I(inode)->io_tree,
					     start_pos, last_pos - 1,
					     &cached_state, GFP_NOFS);
1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285
			for (i = 0; i < num_pages; i++) {
				unlock_page(pages[i]);
				page_cache_release(pages[i]);
			}
			btrfs_wait_ordered_range(inode, start_pos,
						 last_pos - start_pos);
			goto again;
		}
		if (ordered)
			btrfs_put_ordered_extent(ordered);

1286
		clear_extent_bit(&BTRFS_I(inode)->io_tree, start_pos,
1287
				  last_pos - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
1288 1289
				  EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
				  0, 0, &cached_state, GFP_NOFS);
1290 1291 1292
		unlock_extent_cached(&BTRFS_I(inode)->io_tree,
				     start_pos, last_pos - 1, &cached_state,
				     GFP_NOFS);
1293
	}
1294
	for (i = 0; i < num_pages; i++) {
1295 1296
		if (clear_page_dirty_for_io(pages[i]))
			account_page_redirty(pages[i]);
1297 1298 1299
		set_page_extent_mapped(pages[i]);
		WARN_ON(!PageLocked(pages[i]));
	}
C
Chris Mason 已提交
1300
	return 0;
1301 1302 1303 1304 1305 1306 1307 1308
fail:
	while (faili >= 0) {
		unlock_page(pages[faili]);
		page_cache_release(pages[faili]);
		faili--;
	}
	return err;

C
Chris Mason 已提交
1309 1310
}

J
Josef Bacik 已提交
1311 1312 1313
static noinline ssize_t __btrfs_buffered_write(struct file *file,
					       struct iov_iter *i,
					       loff_t pos)
1314
{
1315 1316 1317
	struct inode *inode = fdentry(file)->d_inode;
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct page **pages = NULL;
C
Chris Mason 已提交
1318
	unsigned long first_index;
J
Josef Bacik 已提交
1319 1320
	size_t num_written = 0;
	int nrptrs;
1321
	int ret = 0;
1322
	bool force_page_uptodate = false;
1323

J
Josef Bacik 已提交
1324
	nrptrs = min((iov_iter_count(i) + PAGE_CACHE_SIZE - 1) /
1325 1326
		     PAGE_CACHE_SIZE, PAGE_CACHE_SIZE /
		     (sizeof(struct page *)));
1327 1328
	nrptrs = min(nrptrs, current->nr_dirtied_pause - current->nr_dirtied);
	nrptrs = max(nrptrs, 8);
1329
	pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL);
J
Josef Bacik 已提交
1330 1331
	if (!pages)
		return -ENOMEM;
1332

C
Chris Mason 已提交
1333 1334
	first_index = pos >> PAGE_CACHE_SHIFT;

J
Josef Bacik 已提交
1335
	while (iov_iter_count(i) > 0) {
C
Chris Mason 已提交
1336
		size_t offset = pos & (PAGE_CACHE_SIZE - 1);
J
Josef Bacik 已提交
1337
		size_t write_bytes = min(iov_iter_count(i),
1338
					 nrptrs * (size_t)PAGE_CACHE_SIZE -
1339
					 offset);
Y
Yan, Zheng 已提交
1340 1341
		size_t num_pages = (write_bytes + offset +
				    PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
J
Josef Bacik 已提交
1342 1343
		size_t dirty_pages;
		size_t copied;
C
Chris Mason 已提交
1344

1345
		WARN_ON(num_pages > nrptrs);
1346

1347 1348 1349 1350
		/*
		 * Fault pages before locking them in prepare_pages
		 * to avoid recursive lock
		 */
J
Josef Bacik 已提交
1351
		if (unlikely(iov_iter_fault_in_readable(i, write_bytes))) {
1352
			ret = -EFAULT;
J
Josef Bacik 已提交
1353
			break;
1354 1355 1356 1357
		}

		ret = btrfs_delalloc_reserve_space(inode,
					num_pages << PAGE_CACHE_SHIFT);
1358
		if (ret)
J
Josef Bacik 已提交
1359
			break;
1360

1361 1362 1363 1364 1365
		/*
		 * This is going to setup the pages array with the number of
		 * pages we want, so we don't really need to worry about the
		 * contents of pages from loop to loop
		 */
C
Chris Mason 已提交
1366
		ret = prepare_pages(root, file, pages, num_pages,
1367 1368
				    pos, first_index, write_bytes,
				    force_page_uptodate);
J
Josef Bacik 已提交
1369
		if (ret) {
1370 1371
			btrfs_delalloc_release_space(inode,
					num_pages << PAGE_CACHE_SHIFT);
J
Josef Bacik 已提交
1372
			break;
J
Josef Bacik 已提交
1373
		}
C
Chris Mason 已提交
1374

1375
		copied = btrfs_copy_from_user(pos, num_pages,
J
Josef Bacik 已提交
1376
					   write_bytes, pages, i);
1377 1378 1379 1380 1381 1382 1383 1384

		/*
		 * if we have trouble faulting in the pages, fall
		 * back to one page at a time
		 */
		if (copied < write_bytes)
			nrptrs = 1;

1385 1386
		if (copied == 0) {
			force_page_uptodate = true;
1387
			dirty_pages = 0;
1388 1389
		} else {
			force_page_uptodate = false;
1390 1391 1392
			dirty_pages = (copied + offset +
				       PAGE_CACHE_SIZE - 1) >>
				       PAGE_CACHE_SHIFT;
1393
		}
1394

J
Josef Bacik 已提交
1395 1396 1397 1398 1399 1400 1401
		/*
		 * If we had a short copy we need to release the excess delaloc
		 * bytes we reserved.  We need to increment outstanding_extents
		 * because btrfs_delalloc_release_space will decrement it, but
		 * we still have an outstanding extent for the chunk we actually
		 * managed to copy.
		 */
1402
		if (num_pages > dirty_pages) {
1403 1404 1405 1406 1407
			if (copied > 0) {
				spin_lock(&BTRFS_I(inode)->lock);
				BTRFS_I(inode)->outstanding_extents++;
				spin_unlock(&BTRFS_I(inode)->lock);
			}
1408 1409 1410 1411 1412 1413
			btrfs_delalloc_release_space(inode,
					(num_pages - dirty_pages) <<
					PAGE_CACHE_SHIFT);
		}

		if (copied > 0) {
1414 1415 1416
			ret = btrfs_dirty_pages(root, inode, pages,
						dirty_pages, pos, copied,
						NULL);
J
Josef Bacik 已提交
1417 1418 1419 1420 1421 1422
			if (ret) {
				btrfs_delalloc_release_space(inode,
					dirty_pages << PAGE_CACHE_SHIFT);
				btrfs_drop_pages(pages, num_pages);
				break;
			}
1423
		}
C
Chris Mason 已提交
1424 1425 1426

		btrfs_drop_pages(pages, num_pages);

J
Josef Bacik 已提交
1427 1428
		cond_resched();

1429
		balance_dirty_pages_ratelimited(inode->i_mapping);
J
Josef Bacik 已提交
1430
		if (dirty_pages < (root->leafsize >> PAGE_CACHE_SHIFT) + 1)
1431
			btrfs_btree_balance_dirty(root);
1432

1433 1434
		pos += copied;
		num_written += copied;
J
Josef Bacik 已提交
1435
	}
C
Chris Mason 已提交
1436

J
Josef Bacik 已提交
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
	kfree(pages);

	return num_written ? num_written : ret;
}

static ssize_t __btrfs_direct_write(struct kiocb *iocb,
				    const struct iovec *iov,
				    unsigned long nr_segs, loff_t pos,
				    loff_t *ppos, size_t count, size_t ocount)
{
	struct file *file = iocb->ki_filp;
	struct iov_iter i;
	ssize_t written;
	ssize_t written_buffered;
	loff_t endbyte;
	int err;

	written = generic_file_direct_write(iocb, iov, &nr_segs, pos, ppos,
					    count, ocount);

	if (written < 0 || written == count)
		return written;

	pos += written;
	count -= written;
	iov_iter_init(&i, iov, nr_segs, count, written);
	written_buffered = __btrfs_buffered_write(file, &i, pos);
	if (written_buffered < 0) {
		err = written_buffered;
		goto out;
C
Chris Mason 已提交
1467
	}
J
Josef Bacik 已提交
1468 1469 1470 1471 1472 1473 1474 1475
	endbyte = pos + written_buffered - 1;
	err = filemap_write_and_wait_range(file->f_mapping, pos, endbyte);
	if (err)
		goto out;
	written += written_buffered;
	*ppos = pos + written_buffered;
	invalidate_mapping_pages(file->f_mapping, pos >> PAGE_CACHE_SHIFT,
				 endbyte >> PAGE_CACHE_SHIFT);
C
Chris Mason 已提交
1476
out:
J
Josef Bacik 已提交
1477 1478
	return written ? written : err;
}
1479

1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497
static void update_time_for_write(struct inode *inode)
{
	struct timespec now;

	if (IS_NOCMTIME(inode))
		return;

	now = current_fs_time(inode->i_sb);
	if (!timespec_equal(&inode->i_mtime, &now))
		inode->i_mtime = now;

	if (!timespec_equal(&inode->i_ctime, &now))
		inode->i_ctime = now;

	if (IS_I_VERSION(inode))
		inode_inc_iversion(inode);
}

J
Josef Bacik 已提交
1498 1499 1500 1501 1502 1503 1504 1505
static ssize_t btrfs_file_aio_write(struct kiocb *iocb,
				    const struct iovec *iov,
				    unsigned long nr_segs, loff_t pos)
{
	struct file *file = iocb->ki_filp;
	struct inode *inode = fdentry(file)->d_inode;
	struct btrfs_root *root = BTRFS_I(inode)->root;
	loff_t *ppos = &iocb->ki_pos;
1506
	u64 start_pos;
J
Josef Bacik 已提交
1507 1508 1509
	ssize_t num_written = 0;
	ssize_t err = 0;
	size_t count, ocount;
1510
	bool sync = (file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host);
J
Josef Bacik 已提交
1511

1512
	sb_start_write(inode->i_sb);
J
Josef Bacik 已提交
1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546

	mutex_lock(&inode->i_mutex);

	err = generic_segment_checks(iov, &nr_segs, &ocount, VERIFY_READ);
	if (err) {
		mutex_unlock(&inode->i_mutex);
		goto out;
	}
	count = ocount;

	current->backing_dev_info = inode->i_mapping->backing_dev_info;
	err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
	if (err) {
		mutex_unlock(&inode->i_mutex);
		goto out;
	}

	if (count == 0) {
		mutex_unlock(&inode->i_mutex);
		goto out;
	}

	err = file_remove_suid(file);
	if (err) {
		mutex_unlock(&inode->i_mutex);
		goto out;
	}

	/*
	 * If BTRFS flips readonly due to some impossible error
	 * (fs_info->fs_state now has BTRFS_SUPER_FLAG_ERROR),
	 * although we have opened a file as writable, we have
	 * to stop this write operation to ensure FS consistency.
	 */
1547
	if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) {
J
Josef Bacik 已提交
1548 1549 1550 1551 1552
		mutex_unlock(&inode->i_mutex);
		err = -EROFS;
		goto out;
	}

1553 1554 1555 1556 1557 1558 1559
	/*
	 * We reserve space for updating the inode when we reserve space for the
	 * extent we are going to write, so we will enospc out there.  We don't
	 * need to start yet another transaction to update the inode as we will
	 * update the inode when we finish writing whatever data we write.
	 */
	update_time_for_write(inode);
J
Josef Bacik 已提交
1560

1561 1562 1563 1564 1565 1566 1567 1568 1569
	start_pos = round_down(pos, root->sectorsize);
	if (start_pos > i_size_read(inode)) {
		err = btrfs_cont_expand(inode, i_size_read(inode), start_pos);
		if (err) {
			mutex_unlock(&inode->i_mutex);
			goto out;
		}
	}

1570 1571 1572
	if (sync)
		atomic_inc(&BTRFS_I(inode)->sync_writers);

J
Josef Bacik 已提交
1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586
	if (unlikely(file->f_flags & O_DIRECT)) {
		num_written = __btrfs_direct_write(iocb, iov, nr_segs,
						   pos, ppos, count, ocount);
	} else {
		struct iov_iter i;

		iov_iter_init(&i, iov, nr_segs, count, num_written);

		num_written = __btrfs_buffered_write(file, &i, pos);
		if (num_written > 0)
			*ppos = pos + num_written;
	}

	mutex_unlock(&inode->i_mutex);
1587

1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598
	/*
	 * we want to make sure fsync finds this change
	 * but we haven't joined a transaction running right now.
	 *
	 * Later on, someone is sure to update the inode and get the
	 * real transid recorded.
	 *
	 * We set last_trans now to the fs_info generation + 1,
	 * this will either be one more than the running transaction
	 * or the generation used for the next transaction if there isn't
	 * one running right now.
1599 1600 1601 1602
	 *
	 * We also have to set last_sub_trans to the current log transid,
	 * otherwise subsequent syncs to a file that's been synced in this
	 * transaction will appear to have already occured.
1603 1604
	 */
	BTRFS_I(inode)->last_trans = root->fs_info->generation + 1;
1605
	BTRFS_I(inode)->last_sub_trans = root->log_transid;
J
Josef Bacik 已提交
1606 1607 1608
	if (num_written > 0 || num_written == -EIOCBQUEUED) {
		err = generic_write_sync(file, pos, num_written);
		if (err < 0 && num_written > 0)
1609 1610
			num_written = err;
	}
1611

1612 1613
	if (sync)
		atomic_dec(&BTRFS_I(inode)->sync_writers);
1614
out:
1615
	sb_end_write(inode->i_sb);
C
Chris Mason 已提交
1616 1617 1618 1619
	current->backing_dev_info = NULL;
	return num_written ? num_written : err;
}

C
Chris Mason 已提交
1620
int btrfs_release_file(struct inode *inode, struct file *filp)
1621
{
1622 1623 1624 1625 1626 1627
	/*
	 * ordered_data_close is set by settattr when we are about to truncate
	 * a file from a non-zero size to a zero size.  This tries to
	 * flush down new bytes that may have been written if the
	 * application were using truncate to replace a file in place.
	 */
1628 1629
	if (test_and_clear_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
			       &BTRFS_I(inode)->runtime_flags)) {
1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643
		struct btrfs_trans_handle *trans;
		struct btrfs_root *root = BTRFS_I(inode)->root;

		/*
		 * We need to block on a committing transaction to keep us from
		 * throwing a ordered operation on to the list and causing
		 * something like sync to deadlock trying to flush out this
		 * inode.
		 */
		trans = btrfs_start_transaction(root, 0);
		if (IS_ERR(trans))
			return PTR_ERR(trans);
		btrfs_add_ordered_operation(trans, BTRFS_I(inode)->root, inode);
		btrfs_end_transaction(trans, root);
1644 1645 1646
		if (inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT)
			filemap_flush(inode->i_mapping);
	}
S
Sage Weil 已提交
1647 1648
	if (filp->private_data)
		btrfs_ioctl_trans_end(filp);
1649 1650 1651
	return 0;
}

C
Chris Mason 已提交
1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662
/*
 * fsync call for both files and directories.  This logs the inode into
 * the tree log instead of forcing full commits whenever possible.
 *
 * It needs to call filemap_fdatawait so that all ordered extent updates are
 * in the metadata btree are up to date for copying to the log.
 *
 * It drops the inode mutex before doing the tree log commit.  This is an
 * important optimization for directories because holding the mutex prevents
 * new operations on the dir while we write to disk.
 */
1663
int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
C
Chris Mason 已提交
1664
{
1665
	struct dentry *dentry = file->f_path.dentry;
C
Chris Mason 已提交
1666 1667
	struct inode *inode = dentry->d_inode;
	struct btrfs_root *root = BTRFS_I(inode)->root;
1668
	int ret = 0;
C
Chris Mason 已提交
1669
	struct btrfs_trans_handle *trans;
1670
	bool full_sync = 0;
C
Chris Mason 已提交
1671

1672
	trace_btrfs_sync_file(file, datasync);
1673

1674 1675 1676
	/*
	 * We write the dirty pages in the range and wait until they complete
	 * out of the ->i_mutex. If so, we can flush the dirty pages by
1677 1678
	 * multi-task, and make the performance up.  See
	 * btrfs_wait_ordered_range for an explanation of the ASYNC check.
1679
	 */
1680
	atomic_inc(&BTRFS_I(inode)->sync_writers);
1681 1682 1683 1684
	ret = filemap_fdatawrite_range(inode->i_mapping, start, end);
	if (!ret && test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
			     &BTRFS_I(inode)->runtime_flags))
		ret = filemap_fdatawrite_range(inode->i_mapping, start, end);
1685
	atomic_dec(&BTRFS_I(inode)->sync_writers);
1686 1687 1688
	if (ret)
		return ret;

1689 1690
	mutex_lock(&inode->i_mutex);

1691
	/*
1692 1693
	 * We flush the dirty pages again to avoid some dirty pages in the
	 * range being left.
1694
	 */
M
Miao Xie 已提交
1695
	atomic_inc(&root->log_batch);
1696 1697 1698 1699
	full_sync = test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
			     &BTRFS_I(inode)->runtime_flags);
	if (full_sync)
		btrfs_wait_ordered_range(inode, start, end - start + 1);
M
Miao Xie 已提交
1700
	atomic_inc(&root->log_batch);
1701

C
Chris Mason 已提交
1702
	/*
1703 1704
	 * check the transaction that last modified this inode
	 * and see if its already been committed
C
Chris Mason 已提交
1705
	 */
1706 1707
	if (!BTRFS_I(inode)->last_trans) {
		mutex_unlock(&inode->i_mutex);
1708
		goto out;
1709
	}
1710

1711 1712 1713 1714 1715
	/*
	 * if the last transaction that changed this file was before
	 * the current transaction, we can bail out now without any
	 * syncing
	 */
J
Josef Bacik 已提交
1716
	smp_mb();
1717 1718
	if (btrfs_inode_in_log(inode, root->fs_info->generation) ||
	    BTRFS_I(inode)->last_trans <=
1719 1720
	    root->fs_info->last_trans_committed) {
		BTRFS_I(inode)->last_trans = 0;
J
Josef Bacik 已提交
1721 1722 1723 1724 1725 1726 1727 1728

		/*
		 * We'v had everything committed since the last time we were
		 * modified so clear this flag in case it was set for whatever
		 * reason, it's no longer relevant.
		 */
		clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
			  &BTRFS_I(inode)->runtime_flags);
1729
		mutex_unlock(&inode->i_mutex);
1730 1731 1732 1733
		goto out;
	}

	/*
1734 1735
	 * ok we haven't committed the transaction yet, lets do a commit
	 */
1736
	if (file->private_data)
S
Sage Weil 已提交
1737 1738
		btrfs_ioctl_trans_end(file);

1739 1740 1741
	trans = btrfs_start_transaction(root, 0);
	if (IS_ERR(trans)) {
		ret = PTR_ERR(trans);
1742
		mutex_unlock(&inode->i_mutex);
C
Chris Mason 已提交
1743 1744
		goto out;
	}
1745

1746
	ret = btrfs_log_dentry_safe(trans, root, dentry);
1747 1748
	if (ret < 0) {
		mutex_unlock(&inode->i_mutex);
1749
		goto out;
1750
	}
C
Chris Mason 已提交
1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761

	/* we've logged all the items and now have a consistent
	 * version of the file in the log.  It is possible that
	 * someone will come in and modify the file, but that's
	 * fine because the log is consistent on disk, and we
	 * have references to all of the file's extents
	 *
	 * It is possible that someone will come in and log the
	 * file again, but that will end up using the synchronization
	 * inside btrfs_sync_log to keep things safe.
	 */
1762
	mutex_unlock(&inode->i_mutex);
C
Chris Mason 已提交
1763

1764 1765
	if (ret != BTRFS_NO_LOG_SYNC) {
		if (ret > 0) {
1766 1767 1768 1769 1770 1771 1772
			/*
			 * If we didn't already wait for ordered extents we need
			 * to do that now.
			 */
			if (!full_sync)
				btrfs_wait_ordered_range(inode, start,
							 end - start + 1);
1773
			ret = btrfs_commit_transaction(trans, root);
1774 1775
		} else {
			ret = btrfs_sync_log(trans, root);
1776
			if (ret == 0) {
1777
				ret = btrfs_end_transaction(trans, root);
1778 1779 1780 1781 1782
			} else {
				if (!full_sync)
					btrfs_wait_ordered_range(inode, start,
								 end -
								 start + 1);
1783
				ret = btrfs_commit_transaction(trans, root);
1784
			}
1785 1786 1787
		}
	} else {
		ret = btrfs_end_transaction(trans, root);
1788
	}
C
Chris Mason 已提交
1789
out:
1790
	return ret > 0 ? -EIO : ret;
C
Chris Mason 已提交
1791 1792
}

1793
static const struct vm_operations_struct btrfs_file_vm_ops = {
1794
	.fault		= filemap_fault,
C
Chris Mason 已提交
1795
	.page_mkwrite	= btrfs_page_mkwrite,
1796
	.remap_pages	= generic_file_remap_pages,
C
Chris Mason 已提交
1797 1798 1799 1800
};

static int btrfs_file_mmap(struct file	*filp, struct vm_area_struct *vma)
{
M
Miao Xie 已提交
1801 1802 1803 1804 1805
	struct address_space *mapping = filp->f_mapping;

	if (!mapping->a_ops->readpage)
		return -ENOEXEC;

C
Chris Mason 已提交
1806
	file_accessed(filp);
M
Miao Xie 已提交
1807 1808
	vma->vm_ops = &btrfs_file_vm_ops;

C
Chris Mason 已提交
1809 1810 1811
	return 0;
}

J
Josef Bacik 已提交
1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 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 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916
static int hole_mergeable(struct inode *inode, struct extent_buffer *leaf,
			  int slot, u64 start, u64 end)
{
	struct btrfs_file_extent_item *fi;
	struct btrfs_key key;

	if (slot < 0 || slot >= btrfs_header_nritems(leaf))
		return 0;

	btrfs_item_key_to_cpu(leaf, &key, slot);
	if (key.objectid != btrfs_ino(inode) ||
	    key.type != BTRFS_EXTENT_DATA_KEY)
		return 0;

	fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);

	if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
		return 0;

	if (btrfs_file_extent_disk_bytenr(leaf, fi))
		return 0;

	if (key.offset == end)
		return 1;
	if (key.offset + btrfs_file_extent_num_bytes(leaf, fi) == start)
		return 1;
	return 0;
}

static int fill_holes(struct btrfs_trans_handle *trans, struct inode *inode,
		      struct btrfs_path *path, u64 offset, u64 end)
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct extent_buffer *leaf;
	struct btrfs_file_extent_item *fi;
	struct extent_map *hole_em;
	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
	struct btrfs_key key;
	int ret;

	key.objectid = btrfs_ino(inode);
	key.type = BTRFS_EXTENT_DATA_KEY;
	key.offset = offset;


	ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
	if (ret < 0)
		return ret;
	BUG_ON(!ret);

	leaf = path->nodes[0];
	if (hole_mergeable(inode, leaf, path->slots[0]-1, offset, end)) {
		u64 num_bytes;

		path->slots[0]--;
		fi = btrfs_item_ptr(leaf, path->slots[0],
				    struct btrfs_file_extent_item);
		num_bytes = btrfs_file_extent_num_bytes(leaf, fi) +
			end - offset;
		btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
		btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
		btrfs_set_file_extent_offset(leaf, fi, 0);
		btrfs_mark_buffer_dirty(leaf);
		goto out;
	}

	if (hole_mergeable(inode, leaf, path->slots[0]+1, offset, end)) {
		u64 num_bytes;

		path->slots[0]++;
		key.offset = offset;
		btrfs_set_item_key_safe(trans, root, path, &key);
		fi = btrfs_item_ptr(leaf, path->slots[0],
				    struct btrfs_file_extent_item);
		num_bytes = btrfs_file_extent_num_bytes(leaf, fi) + end -
			offset;
		btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
		btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
		btrfs_set_file_extent_offset(leaf, fi, 0);
		btrfs_mark_buffer_dirty(leaf);
		goto out;
	}
	btrfs_release_path(path);

	ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode), offset,
				       0, 0, end - offset, 0, end - offset,
				       0, 0, 0);
	if (ret)
		return ret;

out:
	btrfs_release_path(path);

	hole_em = alloc_extent_map();
	if (!hole_em) {
		btrfs_drop_extent_cache(inode, offset, end - 1, 0);
		set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
			&BTRFS_I(inode)->runtime_flags);
	} else {
		hole_em->start = offset;
		hole_em->len = end - offset;
		hole_em->orig_start = offset;

		hole_em->block_start = EXTENT_MAP_HOLE;
		hole_em->block_len = 0;
1917
		hole_em->orig_block_len = 0;
J
Josef Bacik 已提交
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
		hole_em->bdev = root->fs_info->fs_devices->latest_bdev;
		hole_em->compress_type = BTRFS_COMPRESS_NONE;
		hole_em->generation = trans->transid;

		do {
			btrfs_drop_extent_cache(inode, offset, end - 1, 0);
			write_lock(&em_tree->lock);
			ret = add_extent_mapping(em_tree, hole_em);
			if (!ret)
				list_move(&hole_em->list,
					  &em_tree->modified_extents);
			write_unlock(&em_tree->lock);
		} while (ret == -EEXIST);
		free_extent_map(hole_em);
		if (ret)
			set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
				&BTRFS_I(inode)->runtime_flags);
	}

	return 0;
}

static int btrfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct extent_state *cached_state = NULL;
	struct btrfs_path *path;
	struct btrfs_block_rsv *rsv;
	struct btrfs_trans_handle *trans;
M
Miao Xie 已提交
1947 1948 1949
	u64 lockstart = round_up(offset, BTRFS_I(inode)->root->sectorsize);
	u64 lockend = round_down(offset + len,
				 BTRFS_I(inode)->root->sectorsize) - 1;
J
Josef Bacik 已提交
1950 1951 1952 1953 1954
	u64 cur_offset = lockstart;
	u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
	u64 drop_end;
	int ret = 0;
	int err = 0;
1955 1956
	bool same_page = ((offset >> PAGE_CACHE_SHIFT) ==
			  ((offset + len - 1) >> PAGE_CACHE_SHIFT));
J
Josef Bacik 已提交
1957 1958 1959 1960

	btrfs_wait_ordered_range(inode, offset, len);

	mutex_lock(&inode->i_mutex);
1961 1962 1963 1964
	/*
	 * We needn't truncate any page which is beyond the end of the file
	 * because we are sure there is no data there.
	 */
J
Josef Bacik 已提交
1965 1966 1967 1968 1969
	/*
	 * Only do this if we are in the same page and we aren't doing the
	 * entire page.
	 */
	if (same_page && len < PAGE_CACHE_SIZE) {
1970 1971
		if (offset < round_up(inode->i_size, PAGE_CACHE_SIZE))
			ret = btrfs_truncate_page(inode, offset, len, 0);
J
Josef Bacik 已提交
1972 1973 1974 1975 1976
		mutex_unlock(&inode->i_mutex);
		return ret;
	}

	/* zero back part of the first page */
1977 1978 1979 1980 1981 1982
	if (offset < round_up(inode->i_size, PAGE_CACHE_SIZE)) {
		ret = btrfs_truncate_page(inode, offset, 0, 0);
		if (ret) {
			mutex_unlock(&inode->i_mutex);
			return ret;
		}
J
Josef Bacik 已提交
1983 1984 1985
	}

	/* zero the front end of the last page */
M
Miao Xie 已提交
1986 1987 1988 1989 1990 1991
	if (offset + len < round_up(inode->i_size, PAGE_CACHE_SIZE)) {
		ret = btrfs_truncate_page(inode, offset + len, 0, 1);
		if (ret) {
			mutex_unlock(&inode->i_mutex);
			return ret;
		}
J
Josef Bacik 已提交
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 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036
	}

	if (lockend < lockstart) {
		mutex_unlock(&inode->i_mutex);
		return 0;
	}

	while (1) {
		struct btrfs_ordered_extent *ordered;

		truncate_pagecache_range(inode, lockstart, lockend);

		lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
				 0, &cached_state);
		ordered = btrfs_lookup_first_ordered_extent(inode, lockend);

		/*
		 * We need to make sure we have no ordered extents in this range
		 * and nobody raced in and read a page in this range, if we did
		 * we need to try again.
		 */
		if ((!ordered ||
		    (ordered->file_offset + ordered->len < lockstart ||
		     ordered->file_offset > lockend)) &&
		     !test_range_bit(&BTRFS_I(inode)->io_tree, lockstart,
				     lockend, EXTENT_UPTODATE, 0,
				     cached_state)) {
			if (ordered)
				btrfs_put_ordered_extent(ordered);
			break;
		}
		if (ordered)
			btrfs_put_ordered_extent(ordered);
		unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart,
				     lockend, &cached_state, GFP_NOFS);
		btrfs_wait_ordered_range(inode, lockstart,
					 lockend - lockstart + 1);
	}

	path = btrfs_alloc_path();
	if (!path) {
		ret = -ENOMEM;
		goto out;
	}

2037
	rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
J
Josef Bacik 已提交
2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 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 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084
	if (!rsv) {
		ret = -ENOMEM;
		goto out_free;
	}
	rsv->size = btrfs_calc_trunc_metadata_size(root, 1);
	rsv->failfast = 1;

	/*
	 * 1 - update the inode
	 * 1 - removing the extents in the range
	 * 1 - adding the hole extent
	 */
	trans = btrfs_start_transaction(root, 3);
	if (IS_ERR(trans)) {
		err = PTR_ERR(trans);
		goto out_free;
	}

	ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
				      min_size);
	BUG_ON(ret);
	trans->block_rsv = rsv;

	while (cur_offset < lockend) {
		ret = __btrfs_drop_extents(trans, root, inode, path,
					   cur_offset, lockend + 1,
					   &drop_end, 1);
		if (ret != -ENOSPC)
			break;

		trans->block_rsv = &root->fs_info->trans_block_rsv;

		ret = fill_holes(trans, inode, path, cur_offset, drop_end);
		if (ret) {
			err = ret;
			break;
		}

		cur_offset = drop_end;

		ret = btrfs_update_inode(trans, root, inode);
		if (ret) {
			err = ret;
			break;
		}

		btrfs_end_transaction(trans, root);
2085
		btrfs_btree_balance_dirty(root);
J
Josef Bacik 已提交
2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115

		trans = btrfs_start_transaction(root, 3);
		if (IS_ERR(trans)) {
			ret = PTR_ERR(trans);
			trans = NULL;
			break;
		}

		ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv,
					      rsv, min_size);
		BUG_ON(ret);	/* shouldn't happen */
		trans->block_rsv = rsv;
	}

	if (ret) {
		err = ret;
		goto out_trans;
	}

	trans->block_rsv = &root->fs_info->trans_block_rsv;
	ret = fill_holes(trans, inode, path, cur_offset, drop_end);
	if (ret) {
		err = ret;
		goto out_trans;
	}

out_trans:
	if (!trans)
		goto out_free;

2116 2117 2118
	inode_inc_iversion(inode);
	inode->i_mtime = inode->i_ctime = CURRENT_TIME;

J
Josef Bacik 已提交
2119 2120 2121
	trans->block_rsv = &root->fs_info->trans_block_rsv;
	ret = btrfs_update_inode(trans, root, inode);
	btrfs_end_transaction(trans, root);
2122
	btrfs_btree_balance_dirty(root);
J
Josef Bacik 已提交
2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134
out_free:
	btrfs_free_path(path);
	btrfs_free_block_rsv(root, rsv);
out:
	unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
			     &cached_state, GFP_NOFS);
	mutex_unlock(&inode->i_mutex);
	if (ret && !err)
		err = ret;
	return err;
}

2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146
static long btrfs_fallocate(struct file *file, int mode,
			    loff_t offset, loff_t len)
{
	struct inode *inode = file->f_path.dentry->d_inode;
	struct extent_state *cached_state = NULL;
	u64 cur_offset;
	u64 last_byte;
	u64 alloc_start;
	u64 alloc_end;
	u64 alloc_hint = 0;
	u64 locked_end;
	struct extent_map *em;
2147
	int blocksize = BTRFS_I(inode)->root->sectorsize;
2148 2149
	int ret;

2150 2151
	alloc_start = round_down(offset, blocksize);
	alloc_end = round_up(offset + len, blocksize);
2152

J
Josef Bacik 已提交
2153 2154
	/* Make sure we aren't being give some crap mode */
	if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
2155 2156
		return -EOPNOTSUPP;

J
Josef Bacik 已提交
2157 2158 2159
	if (mode & FALLOC_FL_PUNCH_HOLE)
		return btrfs_punch_hole(inode, offset, len);

2160 2161 2162 2163
	/*
	 * Make sure we have enough space before we do the
	 * allocation.
	 */
2164
	ret = btrfs_check_data_free_space(inode, alloc_end - alloc_start);
2165 2166 2167
	if (ret)
		return ret;

2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179
	/*
	 * wait for ordered IO before we have any locks.  We'll loop again
	 * below with the locks held.
	 */
	btrfs_wait_ordered_range(inode, alloc_start, alloc_end - alloc_start);

	mutex_lock(&inode->i_mutex);
	ret = inode_newsize_ok(inode, alloc_end);
	if (ret)
		goto out;

	if (alloc_start > inode->i_size) {
2180 2181
		ret = btrfs_cont_expand(inode, i_size_read(inode),
					alloc_start);
2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193
		if (ret)
			goto out;
	}

	locked_end = alloc_end - 1;
	while (1) {
		struct btrfs_ordered_extent *ordered;

		/* the extent lock is ordered inside the running
		 * transaction
		 */
		lock_extent_bits(&BTRFS_I(inode)->io_tree, alloc_start,
2194
				 locked_end, 0, &cached_state);
2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218
		ordered = btrfs_lookup_first_ordered_extent(inode,
							    alloc_end - 1);
		if (ordered &&
		    ordered->file_offset + ordered->len > alloc_start &&
		    ordered->file_offset < alloc_end) {
			btrfs_put_ordered_extent(ordered);
			unlock_extent_cached(&BTRFS_I(inode)->io_tree,
					     alloc_start, locked_end,
					     &cached_state, GFP_NOFS);
			/*
			 * we can't wait on the range with the transaction
			 * running or with the extent lock held
			 */
			btrfs_wait_ordered_range(inode, alloc_start,
						 alloc_end - alloc_start);
		} else {
			if (ordered)
				btrfs_put_ordered_extent(ordered);
			break;
		}
	}

	cur_offset = alloc_start;
	while (1) {
2219 2220
		u64 actual_end;

2221 2222
		em = btrfs_get_extent(inode, NULL, 0, cur_offset,
				      alloc_end - cur_offset, 0);
2223 2224 2225 2226 2227 2228 2229
		if (IS_ERR_OR_NULL(em)) {
			if (!em)
				ret = -ENOMEM;
			else
				ret = PTR_ERR(em);
			break;
		}
2230
		last_byte = min(extent_map_end(em), alloc_end);
2231
		actual_end = min_t(u64, extent_map_end(em), offset + len);
2232
		last_byte = ALIGN(last_byte, blocksize);
2233

2234 2235 2236 2237 2238 2239 2240 2241
		if (em->block_start == EXTENT_MAP_HOLE ||
		    (cur_offset >= inode->i_size &&
		     !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
			ret = btrfs_prealloc_file_range(inode, mode, cur_offset,
							last_byte - cur_offset,
							1 << inode->i_blkbits,
							offset + len,
							&alloc_hint);
2242

2243 2244 2245 2246
			if (ret < 0) {
				free_extent_map(em);
				break;
			}
2247 2248 2249 2250 2251 2252 2253 2254 2255 2256
		} else if (actual_end > inode->i_size &&
			   !(mode & FALLOC_FL_KEEP_SIZE)) {
			/*
			 * We didn't need to allocate any more space, but we
			 * still extended the size of the file so we need to
			 * update i_size.
			 */
			inode->i_ctime = CURRENT_TIME;
			i_size_write(inode, actual_end);
			btrfs_ordered_update_i_size(inode, actual_end, NULL);
2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269
		}
		free_extent_map(em);

		cur_offset = last_byte;
		if (cur_offset >= alloc_end) {
			ret = 0;
			break;
		}
	}
	unlock_extent_cached(&BTRFS_I(inode)->io_tree, alloc_start, locked_end,
			     &cached_state, GFP_NOFS);
out:
	mutex_unlock(&inode->i_mutex);
2270
	/* Let go of our reservation. */
2271
	btrfs_free_reserved_data_space(inode, alloc_end - alloc_start);
2272 2273 2274
	return ret;
}

2275
static int find_desired_extent(struct inode *inode, loff_t *offset, int whence)
J
Josef Bacik 已提交
2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct extent_map *em;
	struct extent_state *cached_state = NULL;
	u64 lockstart = *offset;
	u64 lockend = i_size_read(inode);
	u64 start = *offset;
	u64 orig_start = *offset;
	u64 len = i_size_read(inode);
	u64 last_end = 0;
	int ret = 0;

	lockend = max_t(u64, root->sectorsize, lockend);
	if (lockend <= lockstart)
		lockend = lockstart + root->sectorsize;

L
Liu Bo 已提交
2292
	lockend--;
J
Josef Bacik 已提交
2293 2294 2295 2296 2297 2298 2299
	len = lockend - lockstart + 1;

	len = max_t(u64, len, root->sectorsize);
	if (inode->i_size == 0)
		return -ENXIO;

	lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend, 0,
2300
			 &cached_state);
J
Josef Bacik 已提交
2301 2302 2303 2304 2305 2306 2307 2308 2309

	/*
	 * Delalloc is such a pain.  If we have a hole and we have pending
	 * delalloc for a portion of the hole we will get back a hole that
	 * exists for the entire range since it hasn't been actually written
	 * yet.  So to take care of this case we need to look for an extent just
	 * before the position we want in case there is outstanding delalloc
	 * going on here.
	 */
2310
	if (whence == SEEK_HOLE && start != 0) {
J
Josef Bacik 已提交
2311 2312 2313 2314 2315 2316 2317 2318
		if (start <= root->sectorsize)
			em = btrfs_get_extent_fiemap(inode, NULL, 0, 0,
						     root->sectorsize, 0);
		else
			em = btrfs_get_extent_fiemap(inode, NULL, 0,
						     start - root->sectorsize,
						     root->sectorsize, 0);
		if (IS_ERR(em)) {
2319
			ret = PTR_ERR(em);
J
Josef Bacik 已提交
2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330
			goto out;
		}
		last_end = em->start + em->len;
		if (em->block_start == EXTENT_MAP_DELALLOC)
			last_end = min_t(u64, last_end, inode->i_size);
		free_extent_map(em);
	}

	while (1) {
		em = btrfs_get_extent_fiemap(inode, NULL, 0, start, len, 0);
		if (IS_ERR(em)) {
2331
			ret = PTR_ERR(em);
J
Josef Bacik 已提交
2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343
			break;
		}

		if (em->block_start == EXTENT_MAP_HOLE) {
			if (test_bit(EXTENT_FLAG_VACANCY, &em->flags)) {
				if (last_end <= orig_start) {
					free_extent_map(em);
					ret = -ENXIO;
					break;
				}
			}

2344
			if (whence == SEEK_HOLE) {
J
Josef Bacik 已提交
2345 2346 2347 2348 2349
				*offset = start;
				free_extent_map(em);
				break;
			}
		} else {
2350
			if (whence == SEEK_DATA) {
J
Josef Bacik 已提交
2351 2352 2353 2354 2355 2356 2357 2358
				if (em->block_start == EXTENT_MAP_DELALLOC) {
					if (start >= inode->i_size) {
						free_extent_map(em);
						ret = -ENXIO;
						break;
					}
				}

2359 2360 2361 2362 2363 2364
				if (!test_bit(EXTENT_FLAG_PREALLOC,
					      &em->flags)) {
					*offset = start;
					free_extent_map(em);
					break;
				}
J
Josef Bacik 已提交
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
			}
		}

		start = em->start + em->len;
		last_end = em->start + em->len;

		if (em->block_start == EXTENT_MAP_DELALLOC)
			last_end = min_t(u64, last_end, inode->i_size);

		if (test_bit(EXTENT_FLAG_VACANCY, &em->flags)) {
			free_extent_map(em);
			ret = -ENXIO;
			break;
		}
		free_extent_map(em);
		cond_resched();
	}
	if (!ret)
		*offset = min(*offset, inode->i_size);
out:
	unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
			     &cached_state, GFP_NOFS);
	return ret;
}

2390
static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int whence)
J
Josef Bacik 已提交
2391 2392 2393 2394 2395
{
	struct inode *inode = file->f_mapping->host;
	int ret;

	mutex_lock(&inode->i_mutex);
2396
	switch (whence) {
J
Josef Bacik 已提交
2397 2398
	case SEEK_END:
	case SEEK_CUR:
2399
		offset = generic_file_llseek(file, offset, whence);
J
Josef Bacik 已提交
2400 2401 2402
		goto out;
	case SEEK_DATA:
	case SEEK_HOLE:
2403 2404 2405 2406 2407
		if (offset >= i_size_read(inode)) {
			mutex_unlock(&inode->i_mutex);
			return -ENXIO;
		}

2408
		ret = find_desired_extent(inode, &offset, whence);
J
Josef Bacik 已提交
2409 2410 2411 2412 2413 2414
		if (ret) {
			mutex_unlock(&inode->i_mutex);
			return ret;
		}
	}

2415
	if (offset < 0 && !(file->f_mode & FMODE_UNSIGNED_OFFSET)) {
2416
		offset = -EINVAL;
2417 2418 2419
		goto out;
	}
	if (offset > inode->i_sb->s_maxbytes) {
2420
		offset = -EINVAL;
2421 2422
		goto out;
	}
J
Josef Bacik 已提交
2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433

	/* Special lock needed here? */
	if (offset != file->f_pos) {
		file->f_pos = offset;
		file->f_version = 0;
	}
out:
	mutex_unlock(&inode->i_mutex);
	return offset;
}

2434
const struct file_operations btrfs_file_operations = {
J
Josef Bacik 已提交
2435
	.llseek		= btrfs_file_llseek,
C
Chris Mason 已提交
2436
	.read		= do_sync_read,
2437
	.write		= do_sync_write,
C
Chris Mason 已提交
2438
	.aio_read       = generic_file_aio_read,
C
Chris Mason 已提交
2439
	.splice_read	= generic_file_splice_read,
2440
	.aio_write	= btrfs_file_aio_write,
C
Chris Mason 已提交
2441
	.mmap		= btrfs_file_mmap,
C
Chris Mason 已提交
2442
	.open		= generic_file_open,
2443
	.release	= btrfs_release_file,
C
Chris Mason 已提交
2444
	.fsync		= btrfs_sync_file,
2445
	.fallocate	= btrfs_fallocate,
C
Christoph Hellwig 已提交
2446
	.unlocked_ioctl	= btrfs_ioctl,
C
Chris Mason 已提交
2447
#ifdef CONFIG_COMPAT
C
Christoph Hellwig 已提交
2448
	.compat_ioctl	= btrfs_ioctl,
C
Chris Mason 已提交
2449 2450
#endif
};
2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468

void btrfs_auto_defrag_exit(void)
{
	if (btrfs_inode_defrag_cachep)
		kmem_cache_destroy(btrfs_inode_defrag_cachep);
}

int btrfs_auto_defrag_init(void)
{
	btrfs_inode_defrag_cachep = kmem_cache_create("btrfs_inode_defrag",
					sizeof(struct inode_defrag), 0,
					SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
					NULL);
	if (!btrfs_inode_defrag_cachep)
		return -ENOMEM;

	return 0;
}