file.c 68.5 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/aio.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 "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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static void btrfs_requeue_inode_defrag(struct inode *inode,
				       struct inode_defrag *defrag)
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{
	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;
	}
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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);
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	while (1) {
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		/* Pause the auto defragger. */
		if (test_bit(BTRFS_FS_STATE_REMOUNTING,
			     &fs_info->fs_state))
			break;

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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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static 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,
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			     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 = ALIGN(write_bytes + pos - start_pos, root->sectorsize);
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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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	bool modified;
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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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		modified = false;
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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);
581 582
				break;
			}
583 584
			start = em->start + em->len;
			if (testend)
585 586
				len = start + len - (em->start + em->len);
			free_extent_map(em);
C
Chris Mason 已提交
587
			write_unlock(&em_tree->lock);
588 589
			continue;
		}
C
Chris Mason 已提交
590
		compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
591
		clear_bit(EXTENT_FLAG_PINNED, &em->flags);
L
Liu Bo 已提交
592
		clear_bit(EXTENT_FLAG_LOGGING, &flags);
J
Josef Bacik 已提交
593
		modified = !list_empty(&em->list);
594 595
		if (no_splits)
			goto next;
596

597
		if (em->start < start) {
598 599
			split->start = em->start;
			split->len = start - em->start;
600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619

			if (em->block_start < EXTENT_MAP_LAST_BYTE) {
				split->orig_start = em->orig_start;
				split->block_start = em->block_start;

				if (compressed)
					split->block_len = em->block_len;
				else
					split->block_len = split->len;
				split->orig_block_len = max(split->block_len,
						em->orig_block_len);
				split->ram_bytes = em->ram_bytes;
			} else {
				split->orig_start = split->start;
				split->block_len = 0;
				split->block_start = em->block_start;
				split->orig_block_len = 0;
				split->ram_bytes = split->len;
			}

J
Josef Bacik 已提交
620
			split->generation = gen;
621
			split->bdev = em->bdev;
622
			split->flags = flags;
623
			split->compress_type = em->compress_type;
624
			replace_extent_mapping(em_tree, em, split, modified);
625 626 627 628
			free_extent_map(split);
			split = split2;
			split2 = NULL;
		}
629
		if (testend && em->start + em->len > start + len) {
630 631 632 633 634
			u64 diff = start + len - em->start;

			split->start = start + len;
			split->len = em->start + em->len - (start + len);
			split->bdev = em->bdev;
635
			split->flags = flags;
636
			split->compress_type = em->compress_type;
J
Josef Bacik 已提交
637
			split->generation = gen;
638 639 640

			if (em->block_start < EXTENT_MAP_LAST_BYTE) {
				split->orig_block_len = max(em->block_len,
641
						    em->orig_block_len);
642

643 644 645 646 647 648 649 650 651 652 653
				split->ram_bytes = em->ram_bytes;
				if (compressed) {
					split->block_len = em->block_len;
					split->block_start = em->block_start;
					split->orig_start = em->orig_start;
				} else {
					split->block_len = split->len;
					split->block_start = em->block_start
						+ diff;
					split->orig_start = em->orig_start;
				}
C
Chris Mason 已提交
654
			} else {
655 656 657 658 659
				split->ram_bytes = split->len;
				split->orig_start = split->start;
				split->block_len = 0;
				split->block_start = em->block_start;
				split->orig_block_len = 0;
C
Chris Mason 已提交
660
			}
661

662 663 664 665 666 667 668 669
			if (extent_map_in_tree(em)) {
				replace_extent_mapping(em_tree, em, split,
						       modified);
			} else {
				ret = add_extent_mapping(em_tree, split,
							 modified);
				ASSERT(ret == 0); /* Logic error */
			}
670 671 672
			free_extent_map(split);
			split = NULL;
		}
673
next:
674 675
		if (extent_map_in_tree(em))
			remove_extent_mapping(em_tree, em);
676
		write_unlock(&em_tree->lock);
677

678 679 680 681 682
		/* once for us */
		free_extent_map(em);
		/* once for the tree*/
		free_extent_map(em);
	}
683 684 685 686
	if (split)
		free_extent_map(split);
	if (split2)
		free_extent_map(split2);
687 688
}

C
Chris Mason 已提交
689 690 691 692 693 694 695 696 697
/*
 * 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
698 699 700
int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
			 struct btrfs_root *root, struct inode *inode,
			 struct btrfs_path *path, u64 start, u64 end,
701 702 703 704
			 u64 *drop_end, int drop_cache,
			 int replace_extent,
			 u32 extent_item_size,
			 int *key_inserted)
C
Chris Mason 已提交
705
{
706
	struct extent_buffer *leaf;
Y
Yan, Zheng 已提交
707
	struct btrfs_file_extent_item *fi;
708
	struct btrfs_key key;
Y
Yan, Zheng 已提交
709
	struct btrfs_key new_key;
L
Li Zefan 已提交
710
	u64 ino = btrfs_ino(inode);
Y
Yan, Zheng 已提交
711 712 713 714 715 716 717 718
	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
719
	int recow;
720
	int ret;
721
	int modify_tree = -1;
J
Josef Bacik 已提交
722
	int update_refs = (root->ref_cows || root == root->fs_info->tree_root);
723
	int found = 0;
724
	int leafs_visited = 0;
C
Chris Mason 已提交
725

C
Chris Mason 已提交
726 727
	if (drop_cache)
		btrfs_drop_extent_cache(inode, start, end - 1, 0);
728

729
	if (start >= BTRFS_I(inode)->disk_i_size && !replace_extent)
730 731
		modify_tree = 0;

C
Chris Mason 已提交
732
	while (1) {
C
Chris Mason 已提交
733
		recow = 0;
L
Li Zefan 已提交
734
		ret = btrfs_lookup_file_extent(trans, root, path, ino,
735
					       search_start, modify_tree);
C
Chris Mason 已提交
736
		if (ret < 0)
Y
Yan, Zheng 已提交
737 738 739 740
			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
741
			if (key.objectid == ino &&
Y
Yan, Zheng 已提交
742 743
			    key.type == BTRFS_EXTENT_DATA_KEY)
				path->slots[0]--;
C
Chris Mason 已提交
744
		}
Y
Yan, Zheng 已提交
745
		ret = 0;
746
		leafs_visited++;
747
next_slot:
748
		leaf = path->nodes[0];
Y
Yan, Zheng 已提交
749 750 751 752 753 754 755 756
		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;
757
			}
758
			leafs_visited++;
Y
Yan, Zheng 已提交
759 760 761 762 763
			leaf = path->nodes[0];
			recow = 1;
		}

		btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
L
Li Zefan 已提交
764
		if (key.objectid > ino ||
Y
Yan, Zheng 已提交
765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780
		    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 +
781 782
				btrfs_file_extent_inline_len(leaf,
						     path->slots[0], fi);
783
		} else {
Y
Yan, Zheng 已提交
784
			WARN_ON(1);
785
			extent_end = search_start;
C
Chris Mason 已提交
786 787
		}

Y
Yan, Zheng 已提交
788 789
		if (extent_end <= search_start) {
			path->slots[0]++;
790
			goto next_slot;
C
Chris Mason 已提交
791 792
		}

793
		found = 1;
Y
Yan, Zheng 已提交
794
		search_start = max(key.offset, start);
795 796
		if (recow || !modify_tree) {
			modify_tree = -1;
797
			btrfs_release_path(path);
Y
Yan, Zheng 已提交
798
			continue;
C
Chris Mason 已提交
799
		}
Y
Yan Zheng 已提交
800

Y
Yan, Zheng 已提交
801 802 803 804 805 806 807 808 809 810 811 812 813
		/*
		 *     | - 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) {
814
				btrfs_release_path(path);
Y
Yan, Zheng 已提交
815
				continue;
Y
Yan Zheng 已提交
816
			}
Y
Yan, Zheng 已提交
817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834
			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
835
			if (update_refs && disk_bytenr > 0) {
836
				ret = btrfs_inc_extent_ref(trans, root,
Y
Yan, Zheng 已提交
837 838 839
						disk_bytenr, num_bytes, 0,
						root->root_key.objectid,
						new_key.objectid,
A
Arne Jansen 已提交
840
						start - extent_offset, 0);
841
				BUG_ON(ret); /* -ENOMEM */
842
			}
Y
Yan, Zheng 已提交
843
			key.offset = start;
Y
Yan Zheng 已提交
844
		}
Y
Yan, Zheng 已提交
845 846 847 848 849 850
		/*
		 *  | ---- 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
851

Y
Yan, Zheng 已提交
852 853
			memcpy(&new_key, &key, sizeof(new_key));
			new_key.offset = end;
854
			btrfs_set_item_key_safe(root, path, &new_key);
Y
Yan Zheng 已提交
855

Y
Yan, Zheng 已提交
856 857 858 859 860
			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);
861
			if (update_refs && disk_bytenr > 0)
Y
Yan, Zheng 已提交
862 863
				inode_sub_bytes(inode, end - key.offset);
			break;
C
Chris Mason 已提交
864
		}
865

Y
Yan, Zheng 已提交
866 867 868 869 870 871 872 873
		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);
874

Y
Yan, Zheng 已提交
875 876 877
			btrfs_set_file_extent_num_bytes(leaf, fi,
							start - key.offset);
			btrfs_mark_buffer_dirty(leaf);
878
			if (update_refs && disk_bytenr > 0)
Y
Yan, Zheng 已提交
879 880 881
				inode_sub_bytes(inode, extent_end - start);
			if (end == extent_end)
				break;
C
Chris Mason 已提交
882

Y
Yan, Zheng 已提交
883 884
			path->slots[0]++;
			goto next_slot;
Z
Zheng Yan 已提交
885 886
		}

Y
Yan, Zheng 已提交
887 888 889 890 891 892 893 894 895 896 897 898
		/*
		 *  | ---- 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
899

J
Josef Bacik 已提交
900 901
			if (update_refs &&
			    extent_type == BTRFS_FILE_EXTENT_INLINE) {
902
				inode_sub_bytes(inode,
Y
Yan, Zheng 已提交
903 904 905
						extent_end - key.offset);
				extent_end = ALIGN(extent_end,
						   root->sectorsize);
J
Josef Bacik 已提交
906
			} else if (update_refs && disk_bytenr > 0) {
Z
Zheng Yan 已提交
907
				ret = btrfs_free_extent(trans, root,
Y
Yan, Zheng 已提交
908 909
						disk_bytenr, num_bytes, 0,
						root->root_key.objectid,
910
						key.objectid, key.offset -
A
Arne Jansen 已提交
911
						extent_offset, 0);
912
				BUG_ON(ret); /* -ENOMEM */
Y
Yan, Zheng 已提交
913 914
				inode_sub_bytes(inode,
						extent_end - key.offset);
Z
Zheng Yan 已提交
915 916
			}

Y
Yan, Zheng 已提交
917 918 919 920 921 922 923 924 925 926
			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);
927 928
			if (ret) {
				btrfs_abort_transaction(trans, root, ret);
J
Josef Bacik 已提交
929
				break;
930
			}
Y
Yan, Zheng 已提交
931 932 933 934

			del_nr = 0;
			del_slot = 0;

935
			btrfs_release_path(path);
Y
Yan, Zheng 已提交
936
			continue;
C
Chris Mason 已提交
937
		}
Y
Yan, Zheng 已提交
938 939

		BUG_ON(1);
C
Chris Mason 已提交
940
	}
Y
Yan, Zheng 已提交
941

942
	if (!ret && del_nr > 0) {
943 944 945 946
		/*
		 * Set path->slots[0] to first slot, so that after the delete
		 * if items are move off from our leaf to its immediate left or
		 * right neighbor leafs, we end up with a correct and adjusted
947
		 * path->slots[0] for our insertion (if replace_extent != 0).
948 949
		 */
		path->slots[0] = del_slot;
Y
Yan, Zheng 已提交
950
		ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
951 952
		if (ret)
			btrfs_abort_transaction(trans, root, ret);
953
	}
954

955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975
	leaf = path->nodes[0];
	/*
	 * If btrfs_del_items() was called, it might have deleted a leaf, in
	 * which case it unlocked our path, so check path->locks[0] matches a
	 * write lock.
	 */
	if (!ret && replace_extent && leafs_visited == 1 &&
	    (path->locks[0] == BTRFS_WRITE_LOCK_BLOCKING ||
	     path->locks[0] == BTRFS_WRITE_LOCK) &&
	    btrfs_leaf_free_space(root, leaf) >=
	    sizeof(struct btrfs_item) + extent_item_size) {

		key.objectid = ino;
		key.type = BTRFS_EXTENT_DATA_KEY;
		key.offset = start;
		if (!del_nr && path->slots[0] < btrfs_header_nritems(leaf)) {
			struct btrfs_key slot_key;

			btrfs_item_key_to_cpu(leaf, &slot_key, path->slots[0]);
			if (btrfs_comp_cpu_keys(&key, &slot_key) > 0)
				path->slots[0]++;
976
		}
977 978 979 980 981 982
		setup_items_for_insert(root, path, &key,
				       &extent_item_size,
				       extent_item_size,
				       sizeof(struct btrfs_item) +
				       extent_item_size, 1);
		*key_inserted = 1;
Y
Yan Zheng 已提交
983
	}
Y
Yan, Zheng 已提交
984

985 986
	if (!replace_extent || !(*key_inserted))
		btrfs_release_path(path);
J
Josef Bacik 已提交
987
	if (drop_end)
988
		*drop_end = found ? min(end, extent_end) : end;
J
Josef Bacik 已提交
989 990 991 992 993
	return ret;
}

int btrfs_drop_extents(struct btrfs_trans_handle *trans,
		       struct btrfs_root *root, struct inode *inode, u64 start,
994
		       u64 end, int drop_cache)
J
Josef Bacik 已提交
995 996 997 998 999 1000 1001
{
	struct btrfs_path *path;
	int ret;

	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;
J
Josef Bacik 已提交
1002
	ret = __btrfs_drop_extents(trans, root, inode, path, start, end, NULL,
1003
				   drop_cache, 0, 0, NULL);
Y
Yan, Zheng 已提交
1004
	btrfs_free_path(path);
C
Chris Mason 已提交
1005 1006 1007
	return ret;
}

Y
Yan Zheng 已提交
1008
static int extent_mergeable(struct extent_buffer *leaf, int slot,
1009 1010
			    u64 objectid, u64 bytenr, u64 orig_offset,
			    u64 *start, u64 *end)
Y
Yan Zheng 已提交
1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025
{
	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 ||
1026
	    btrfs_file_extent_offset(leaf, fi) != key.offset - orig_offset ||
Y
Yan Zheng 已提交
1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050
	    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
1051
	struct btrfs_root *root = BTRFS_I(inode)->root;
Y
Yan Zheng 已提交
1052 1053 1054 1055
	struct extent_buffer *leaf;
	struct btrfs_path *path;
	struct btrfs_file_extent_item *fi;
	struct btrfs_key key;
Y
Yan, Zheng 已提交
1056
	struct btrfs_key new_key;
Y
Yan Zheng 已提交
1057 1058 1059
	u64 bytenr;
	u64 num_bytes;
	u64 extent_end;
1060
	u64 orig_offset;
Y
Yan Zheng 已提交
1061 1062
	u64 other_start;
	u64 other_end;
Y
Yan, Zheng 已提交
1063 1064 1065
	u64 split;
	int del_nr = 0;
	int del_slot = 0;
1066
	int recow;
Y
Yan Zheng 已提交
1067
	int ret;
L
Li Zefan 已提交
1068
	u64 ino = btrfs_ino(inode);
Y
Yan Zheng 已提交
1069 1070

	path = btrfs_alloc_path();
1071 1072
	if (!path)
		return -ENOMEM;
Y
Yan Zheng 已提交
1073
again:
1074
	recow = 0;
Y
Yan, Zheng 已提交
1075
	split = start;
L
Li Zefan 已提交
1076
	key.objectid = ino;
Y
Yan Zheng 已提交
1077
	key.type = BTRFS_EXTENT_DATA_KEY;
Y
Yan, Zheng 已提交
1078
	key.offset = split;
Y
Yan Zheng 已提交
1079 1080

	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1081 1082
	if (ret < 0)
		goto out;
Y
Yan Zheng 已提交
1083 1084 1085 1086 1087
	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
1088
	BUG_ON(key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY);
Y
Yan Zheng 已提交
1089 1090
	fi = btrfs_item_ptr(leaf, path->slots[0],
			    struct btrfs_file_extent_item);
Y
Yan, Zheng 已提交
1091 1092
	BUG_ON(btrfs_file_extent_type(leaf, fi) !=
	       BTRFS_FILE_EXTENT_PREALLOC);
Y
Yan Zheng 已提交
1093 1094 1095 1096 1097
	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);
1098
	orig_offset = key.offset - btrfs_file_extent_offset(leaf, fi);
1099 1100 1101 1102 1103 1104
	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
1105
				     ino, bytenr, orig_offset,
1106 1107
				     &other_start, &other_end)) {
			new_key.offset = end;
1108
			btrfs_set_item_key_safe(root, path, &new_key);
1109 1110
			fi = btrfs_item_ptr(leaf, path->slots[0],
					    struct btrfs_file_extent_item);
1111 1112
			btrfs_set_file_extent_generation(leaf, fi,
							 trans->transid);
1113 1114 1115 1116 1117 1118
			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);
1119 1120
			btrfs_set_file_extent_generation(leaf, fi,
							 trans->transid);
1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131
			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
1132
				     ino, bytenr, orig_offset,
1133 1134 1135 1136 1137
				     &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);
1138 1139
			btrfs_set_file_extent_generation(leaf, fi,
							 trans->transid);
1140 1141
			path->slots[0]++;
			new_key.offset = start;
1142
			btrfs_set_item_key_safe(root, path, &new_key);
1143 1144 1145

			fi = btrfs_item_ptr(leaf, path->slots[0],
					    struct btrfs_file_extent_item);
1146 1147
			btrfs_set_file_extent_generation(leaf, fi,
							 trans->transid);
1148 1149 1150 1151 1152 1153 1154 1155
			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
1156

Y
Yan, Zheng 已提交
1157 1158 1159 1160 1161 1162 1163
	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) {
1164
			btrfs_release_path(path);
Y
Yan, Zheng 已提交
1165
			goto again;
Y
Yan Zheng 已提交
1166
		}
1167 1168 1169 1170
		if (ret < 0) {
			btrfs_abort_transaction(trans, root, ret);
			goto out;
		}
Y
Yan Zheng 已提交
1171

Y
Yan, Zheng 已提交
1172 1173
		leaf = path->nodes[0];
		fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
Y
Yan Zheng 已提交
1174
				    struct btrfs_file_extent_item);
1175
		btrfs_set_file_extent_generation(leaf, fi, trans->transid);
Y
Yan Zheng 已提交
1176
		btrfs_set_file_extent_num_bytes(leaf, fi,
Y
Yan, Zheng 已提交
1177 1178 1179 1180 1181
						split - key.offset);

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

1182
		btrfs_set_file_extent_generation(leaf, fi, trans->transid);
Y
Yan, Zheng 已提交
1183 1184 1185
		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
1186 1187
		btrfs_mark_buffer_dirty(leaf);

Y
Yan, Zheng 已提交
1188 1189
		ret = btrfs_inc_extent_ref(trans, root, bytenr, num_bytes, 0,
					   root->root_key.objectid,
A
Arne Jansen 已提交
1190
					   ino, orig_offset, 0);
1191
		BUG_ON(ret); /* -ENOMEM */
Y
Yan Zheng 已提交
1192

Y
Yan, Zheng 已提交
1193 1194 1195 1196
		if (split == start) {
			key.offset = start;
		} else {
			BUG_ON(start != key.offset);
Y
Yan Zheng 已提交
1197
			path->slots[0]--;
Y
Yan, Zheng 已提交
1198
			extent_end = end;
Y
Yan Zheng 已提交
1199
		}
1200
		recow = 1;
Y
Yan Zheng 已提交
1201 1202
	}

Y
Yan, Zheng 已提交
1203 1204
	other_start = end;
	other_end = 0;
1205
	if (extent_mergeable(leaf, path->slots[0] + 1,
L
Li Zefan 已提交
1206
			     ino, bytenr, orig_offset,
1207 1208
			     &other_start, &other_end)) {
		if (recow) {
1209
			btrfs_release_path(path);
1210 1211
			goto again;
		}
Y
Yan, Zheng 已提交
1212 1213 1214 1215 1216
		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
1217
					ino, orig_offset, 0);
1218
		BUG_ON(ret); /* -ENOMEM */
Y
Yan Zheng 已提交
1219
	}
Y
Yan, Zheng 已提交
1220 1221
	other_start = 0;
	other_end = start;
1222
	if (extent_mergeable(leaf, path->slots[0] - 1,
L
Li Zefan 已提交
1223
			     ino, bytenr, orig_offset,
1224 1225
			     &other_start, &other_end)) {
		if (recow) {
1226
			btrfs_release_path(path);
1227 1228
			goto again;
		}
Y
Yan, Zheng 已提交
1229 1230 1231 1232 1233
		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
1234
					ino, orig_offset, 0);
1235
		BUG_ON(ret); /* -ENOMEM */
Y
Yan, Zheng 已提交
1236 1237
	}
	if (del_nr == 0) {
1238 1239
		fi = btrfs_item_ptr(leaf, path->slots[0],
			   struct btrfs_file_extent_item);
Y
Yan, Zheng 已提交
1240 1241
		btrfs_set_file_extent_type(leaf, fi,
					   BTRFS_FILE_EXTENT_REG);
1242
		btrfs_set_file_extent_generation(leaf, fi, trans->transid);
Y
Yan, Zheng 已提交
1243
		btrfs_mark_buffer_dirty(leaf);
1244
	} else {
1245 1246
		fi = btrfs_item_ptr(leaf, del_slot - 1,
			   struct btrfs_file_extent_item);
1247 1248
		btrfs_set_file_extent_type(leaf, fi,
					   BTRFS_FILE_EXTENT_REG);
1249
		btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1250 1251 1252
		btrfs_set_file_extent_num_bytes(leaf, fi,
						extent_end - key.offset);
		btrfs_mark_buffer_dirty(leaf);
Y
Yan, Zheng 已提交
1253

1254
		ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
1255 1256 1257 1258
		if (ret < 0) {
			btrfs_abort_transaction(trans, root, ret);
			goto out;
		}
1259
	}
Y
Yan, Zheng 已提交
1260
out:
Y
Yan Zheng 已提交
1261 1262 1263 1264
	btrfs_free_path(path);
	return 0;
}

1265 1266 1267 1268
/*
 * on error we return an unlocked page and the error value
 * on success we return a locked page and 0
 */
1269 1270
static int prepare_uptodate_page(struct page *page, u64 pos,
				 bool force_uptodate)
1271 1272 1273
{
	int ret = 0;

1274 1275
	if (((pos & (PAGE_CACHE_SIZE - 1)) || force_uptodate) &&
	    !PageUptodate(page)) {
1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287
		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
1288
/*
1289
 * this just gets pages into the page cache and locks them down.
C
Chris Mason 已提交
1290
 */
1291 1292 1293
static noinline int prepare_pages(struct inode *inode, struct page **pages,
				  size_t num_pages, loff_t pos,
				  size_t write_bytes, bool force_uptodate)
C
Chris Mason 已提交
1294 1295 1296
{
	int i;
	unsigned long index = pos >> PAGE_CACHE_SHIFT;
1297
	gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1298
	int err = 0;
1299
	int faili;
1300

C
Chris Mason 已提交
1301
	for (i = 0; i < num_pages; i++) {
1302
		pages[i] = find_or_create_page(inode->i_mapping, index + i,
1303
					       mask | __GFP_WRITE);
C
Chris Mason 已提交
1304
		if (!pages[i]) {
1305 1306 1307 1308 1309 1310
			faili = i - 1;
			err = -ENOMEM;
			goto fail;
		}

		if (i == 0)
1311 1312
			err = prepare_uptodate_page(pages[i], pos,
						    force_uptodate);
1313 1314
		if (i == num_pages - 1)
			err = prepare_uptodate_page(pages[i],
1315
						    pos + write_bytes, false);
1316 1317 1318 1319
		if (err) {
			page_cache_release(pages[i]);
			faili = i - 1;
			goto fail;
C
Chris Mason 已提交
1320
		}
C
Chris Mason 已提交
1321
		wait_on_page_writeback(pages[i]);
C
Chris Mason 已提交
1322
	}
1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358

	return 0;
fail:
	while (faili >= 0) {
		unlock_page(pages[faili]);
		page_cache_release(pages[faili]);
		faili--;
	}
	return err;

}

/*
 * This function locks the extent and properly waits for data=ordered extents
 * to finish before allowing the pages to be modified if need.
 *
 * The return value:
 * 1 - the extent is locked
 * 0 - the extent is not locked, and everything is OK
 * -EAGAIN - need re-prepare the pages
 * the other < 0 number - Something wrong happens
 */
static noinline int
lock_and_cleanup_extent_if_need(struct inode *inode, struct page **pages,
				size_t num_pages, loff_t pos,
				u64 *lockstart, u64 *lockend,
				struct extent_state **cached_state)
{
	u64 start_pos;
	u64 last_pos;
	int i;
	int ret = 0;

	start_pos = pos & ~((u64)PAGE_CACHE_SIZE - 1);
	last_pos = start_pos + ((u64)num_pages << PAGE_CACHE_SHIFT) - 1;

1359
	if (start_pos < inode->i_size) {
1360
		struct btrfs_ordered_extent *ordered;
1361
		lock_extent_bits(&BTRFS_I(inode)->io_tree,
1362 1363
				 start_pos, last_pos, 0, cached_state);
		ordered = btrfs_lookup_first_ordered_extent(inode, last_pos);
1364 1365
		if (ordered &&
		    ordered->file_offset + ordered->len > start_pos &&
1366
		    ordered->file_offset <= last_pos) {
1367
			btrfs_put_ordered_extent(ordered);
1368
			unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1369 1370
					     start_pos, last_pos,
					     cached_state, GFP_NOFS);
1371 1372 1373 1374
			for (i = 0; i < num_pages; i++) {
				unlock_page(pages[i]);
				page_cache_release(pages[i]);
			}
1375 1376 1377 1378 1379 1380
			ret = btrfs_wait_ordered_range(inode, start_pos,
						last_pos - start_pos + 1);
			if (ret)
				return ret;
			else
				return -EAGAIN;
1381 1382 1383 1384
		}
		if (ordered)
			btrfs_put_ordered_extent(ordered);

1385
		clear_extent_bit(&BTRFS_I(inode)->io_tree, start_pos,
1386
				  last_pos, EXTENT_DIRTY | EXTENT_DELALLOC |
1387
				  EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
1388 1389 1390 1391
				  0, 0, cached_state, GFP_NOFS);
		*lockstart = start_pos;
		*lockend = last_pos;
		ret = 1;
1392
	}
1393

1394
	for (i = 0; i < num_pages; i++) {
1395 1396
		if (clear_page_dirty_for_io(pages[i]))
			account_page_redirty(pages[i]);
1397 1398 1399
		set_page_extent_mapped(pages[i]);
		WARN_ON(!PageLocked(pages[i]));
	}
1400

1401
	return ret;
C
Chris Mason 已提交
1402 1403
}

1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428
static noinline int check_can_nocow(struct inode *inode, loff_t pos,
				    size_t *write_bytes)
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_ordered_extent *ordered;
	u64 lockstart, lockend;
	u64 num_bytes;
	int ret;

	lockstart = round_down(pos, root->sectorsize);
	lockend = lockstart + round_up(*write_bytes, root->sectorsize) - 1;

	while (1) {
		lock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend);
		ordered = btrfs_lookup_ordered_range(inode, lockstart,
						     lockend - lockstart + 1);
		if (!ordered) {
			break;
		}
		unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend);
		btrfs_start_ordered_extent(inode, ordered, 1);
		btrfs_put_ordered_extent(ordered);
	}

	num_bytes = lockend - lockstart + 1;
1429
	ret = can_nocow_extent(inode, lockstart, &num_bytes, NULL, NULL, NULL);
1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444
	if (ret <= 0) {
		ret = 0;
	} else {
		clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
				 EXTENT_DIRTY | EXTENT_DELALLOC |
				 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 0, 0,
				 NULL, GFP_NOFS);
		*write_bytes = min_t(size_t, *write_bytes, num_bytes);
	}

	unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend);

	return ret;
}

J
Josef Bacik 已提交
1445 1446 1447
static noinline ssize_t __btrfs_buffered_write(struct file *file,
					       struct iov_iter *i,
					       loff_t pos)
1448
{
A
Al Viro 已提交
1449
	struct inode *inode = file_inode(file);
1450 1451
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct page **pages = NULL;
1452
	struct extent_state *cached_state = NULL;
1453
	u64 release_bytes = 0;
1454 1455
	u64 lockstart;
	u64 lockend;
C
Chris Mason 已提交
1456
	unsigned long first_index;
J
Josef Bacik 已提交
1457 1458
	size_t num_written = 0;
	int nrptrs;
1459
	int ret = 0;
1460
	bool only_release_metadata = false;
1461
	bool force_page_uptodate = false;
1462
	bool need_unlock;
1463

J
Josef Bacik 已提交
1464
	nrptrs = min((iov_iter_count(i) + PAGE_CACHE_SIZE - 1) /
1465 1466
		     PAGE_CACHE_SIZE, PAGE_CACHE_SIZE /
		     (sizeof(struct page *)));
1467 1468
	nrptrs = min(nrptrs, current->nr_dirtied_pause - current->nr_dirtied);
	nrptrs = max(nrptrs, 8);
1469
	pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL);
J
Josef Bacik 已提交
1470 1471
	if (!pages)
		return -ENOMEM;
1472

C
Chris Mason 已提交
1473 1474
	first_index = pos >> PAGE_CACHE_SHIFT;

J
Josef Bacik 已提交
1475
	while (iov_iter_count(i) > 0) {
C
Chris Mason 已提交
1476
		size_t offset = pos & (PAGE_CACHE_SIZE - 1);
J
Josef Bacik 已提交
1477
		size_t write_bytes = min(iov_iter_count(i),
1478
					 nrptrs * (size_t)PAGE_CACHE_SIZE -
1479
					 offset);
Y
Yan, Zheng 已提交
1480 1481
		size_t num_pages = (write_bytes + offset +
				    PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
1482
		size_t reserve_bytes;
J
Josef Bacik 已提交
1483 1484
		size_t dirty_pages;
		size_t copied;
C
Chris Mason 已提交
1485

1486
		WARN_ON(num_pages > nrptrs);
1487

1488 1489 1490 1491
		/*
		 * Fault pages before locking them in prepare_pages
		 * to avoid recursive lock
		 */
J
Josef Bacik 已提交
1492
		if (unlikely(iov_iter_fault_in_readable(i, write_bytes))) {
1493
			ret = -EFAULT;
J
Josef Bacik 已提交
1494
			break;
1495 1496
		}

1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518
		reserve_bytes = num_pages << PAGE_CACHE_SHIFT;
		ret = btrfs_check_data_free_space(inode, reserve_bytes);
		if (ret == -ENOSPC &&
		    (BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW |
					      BTRFS_INODE_PREALLOC))) {
			ret = check_can_nocow(inode, pos, &write_bytes);
			if (ret > 0) {
				only_release_metadata = true;
				/*
				 * our prealloc extent may be smaller than
				 * write_bytes, so scale down.
				 */
				num_pages = (write_bytes + offset +
					     PAGE_CACHE_SIZE - 1) >>
					PAGE_CACHE_SHIFT;
				reserve_bytes = num_pages << PAGE_CACHE_SHIFT;
				ret = 0;
			} else {
				ret = -ENOSPC;
			}
		}

1519
		if (ret)
J
Josef Bacik 已提交
1520
			break;
1521

1522 1523 1524 1525 1526 1527 1528 1529 1530
		ret = btrfs_delalloc_reserve_metadata(inode, reserve_bytes);
		if (ret) {
			if (!only_release_metadata)
				btrfs_free_reserved_data_space(inode,
							       reserve_bytes);
			break;
		}

		release_bytes = reserve_bytes;
1531 1532
		need_unlock = false;
again:
1533 1534 1535 1536 1537
		/*
		 * 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
		 */
1538 1539
		ret = prepare_pages(inode, pages, num_pages,
				    pos, write_bytes,
1540
				    force_page_uptodate);
1541
		if (ret)
J
Josef Bacik 已提交
1542
			break;
C
Chris Mason 已提交
1543

1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555
		ret = lock_and_cleanup_extent_if_need(inode, pages, num_pages,
						      pos, &lockstart, &lockend,
						      &cached_state);
		if (ret < 0) {
			if (ret == -EAGAIN)
				goto again;
			break;
		} else if (ret > 0) {
			need_unlock = true;
			ret = 0;
		}

1556
		copied = btrfs_copy_from_user(pos, num_pages,
J
Josef Bacik 已提交
1557
					   write_bytes, pages, i);
1558 1559 1560 1561 1562 1563 1564 1565

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

1566 1567
		if (copied == 0) {
			force_page_uptodate = true;
1568
			dirty_pages = 0;
1569 1570
		} else {
			force_page_uptodate = false;
1571 1572 1573
			dirty_pages = (copied + offset +
				       PAGE_CACHE_SIZE - 1) >>
				       PAGE_CACHE_SHIFT;
1574
		}
1575

J
Josef Bacik 已提交
1576 1577 1578 1579 1580 1581 1582
		/*
		 * 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.
		 */
1583
		if (num_pages > dirty_pages) {
1584 1585
			release_bytes = (num_pages - dirty_pages) <<
				PAGE_CACHE_SHIFT;
1586 1587 1588 1589 1590
			if (copied > 0) {
				spin_lock(&BTRFS_I(inode)->lock);
				BTRFS_I(inode)->outstanding_extents++;
				spin_unlock(&BTRFS_I(inode)->lock);
			}
1591 1592 1593 1594 1595 1596
			if (only_release_metadata)
				btrfs_delalloc_release_metadata(inode,
								release_bytes);
			else
				btrfs_delalloc_release_space(inode,
							     release_bytes);
1597 1598
		}

1599
		release_bytes = dirty_pages << PAGE_CACHE_SHIFT;
1600 1601

		if (copied > 0)
1602 1603 1604
			ret = btrfs_dirty_pages(root, inode, pages,
						dirty_pages, pos, copied,
						NULL);
1605 1606 1607 1608
		if (need_unlock)
			unlock_extent_cached(&BTRFS_I(inode)->io_tree,
					     lockstart, lockend, &cached_state,
					     GFP_NOFS);
1609 1610
		if (ret) {
			btrfs_drop_pages(pages, num_pages);
1611
			break;
1612
		}
C
Chris Mason 已提交
1613

1614
		release_bytes = 0;
1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625
		if (only_release_metadata && copied > 0) {
			u64 lockstart = round_down(pos, root->sectorsize);
			u64 lockend = lockstart +
				(dirty_pages << PAGE_CACHE_SHIFT) - 1;

			set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
				       lockend, EXTENT_NORESERVE, NULL,
				       NULL, GFP_NOFS);
			only_release_metadata = false;
		}

1626 1627
		btrfs_drop_pages(pages, num_pages);

J
Josef Bacik 已提交
1628 1629
		cond_resched();

1630
		balance_dirty_pages_ratelimited(inode->i_mapping);
J
Josef Bacik 已提交
1631
		if (dirty_pages < (root->leafsize >> PAGE_CACHE_SHIFT) + 1)
1632
			btrfs_btree_balance_dirty(root);
1633

1634 1635
		pos += copied;
		num_written += copied;
J
Josef Bacik 已提交
1636
	}
C
Chris Mason 已提交
1637

J
Josef Bacik 已提交
1638 1639
	kfree(pages);

1640 1641 1642 1643 1644 1645 1646
	if (release_bytes) {
		if (only_release_metadata)
			btrfs_delalloc_release_metadata(inode, release_bytes);
		else
			btrfs_delalloc_release_space(inode, release_bytes);
	}

J
Josef Bacik 已提交
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
	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
1675
	}
J
Josef Bacik 已提交
1676 1677 1678 1679 1680 1681 1682 1683
	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
1684
out:
J
Josef Bacik 已提交
1685 1686
	return written ? written : err;
}
1687

1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705
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
1706 1707 1708 1709 1710
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;
A
Al Viro 已提交
1711
	struct inode *inode = file_inode(file);
J
Josef Bacik 已提交
1712 1713
	struct btrfs_root *root = BTRFS_I(inode)->root;
	loff_t *ppos = &iocb->ki_pos;
1714
	u64 start_pos;
J
Josef Bacik 已提交
1715 1716 1717
	ssize_t num_written = 0;
	ssize_t err = 0;
	size_t count, ocount;
1718
	bool sync = (file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host);
J
Josef Bacik 已提交
1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752

	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.
	 */
1753
	if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) {
J
Josef Bacik 已提交
1754 1755 1756 1757 1758
		mutex_unlock(&inode->i_mutex);
		err = -EROFS;
		goto out;
	}

1759 1760 1761 1762 1763 1764 1765
	/*
	 * 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
1766

1767 1768 1769 1770 1771 1772 1773 1774 1775
	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;
		}
	}

1776 1777 1778
	if (sync)
		atomic_inc(&BTRFS_I(inode)->sync_writers);

J
Josef Bacik 已提交
1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792
	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);
1793

1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804
	/*
	 * 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.
1805 1806 1807 1808
	 *
	 * 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.
1809 1810
	 */
	BTRFS_I(inode)->last_trans = root->fs_info->generation + 1;
1811
	BTRFS_I(inode)->last_sub_trans = root->log_transid;
1812
	if (num_written > 0) {
J
Josef Bacik 已提交
1813 1814
		err = generic_write_sync(file, pos, num_written);
		if (err < 0 && num_written > 0)
1815 1816
			num_written = err;
	}
1817

1818 1819
	if (sync)
		atomic_dec(&BTRFS_I(inode)->sync_writers);
1820
out:
C
Chris Mason 已提交
1821 1822 1823 1824
	current->backing_dev_info = NULL;
	return num_written ? num_written : err;
}

C
Chris Mason 已提交
1825
int btrfs_release_file(struct inode *inode, struct file *filp)
1826
{
1827 1828 1829 1830 1831 1832
	/*
	 * 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.
	 */
1833 1834
	if (test_and_clear_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
			       &BTRFS_I(inode)->runtime_flags)) {
1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848
		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);
1849 1850 1851
		if (inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT)
			filemap_flush(inode->i_mapping);
	}
S
Sage Weil 已提交
1852 1853
	if (filp->private_data)
		btrfs_ioctl_trans_end(filp);
1854 1855 1856
	return 0;
}

C
Chris Mason 已提交
1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867
/*
 * 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.
 */
1868
int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
C
Chris Mason 已提交
1869
{
1870
	struct dentry *dentry = file->f_path.dentry;
C
Chris Mason 已提交
1871 1872 1873
	struct inode *inode = dentry->d_inode;
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_trans_handle *trans;
1874 1875
	struct btrfs_log_ctx ctx;
	int ret = 0;
1876
	bool full_sync = 0;
C
Chris Mason 已提交
1877

1878
	trace_btrfs_sync_file(file, datasync);
1879

1880 1881 1882
	/*
	 * 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
1883 1884
	 * multi-task, and make the performance up.  See
	 * btrfs_wait_ordered_range for an explanation of the ASYNC check.
1885
	 */
1886
	atomic_inc(&BTRFS_I(inode)->sync_writers);
1887 1888 1889 1890
	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);
1891
	atomic_dec(&BTRFS_I(inode)->sync_writers);
1892 1893 1894
	if (ret)
		return ret;

1895 1896
	mutex_lock(&inode->i_mutex);

1897
	/*
1898 1899
	 * We flush the dirty pages again to avoid some dirty pages in the
	 * range being left.
1900
	 */
M
Miao Xie 已提交
1901
	atomic_inc(&root->log_batch);
1902 1903
	full_sync = test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
			     &BTRFS_I(inode)->runtime_flags);
1904 1905 1906 1907 1908 1909 1910
	if (full_sync) {
		ret = btrfs_wait_ordered_range(inode, start, end - start + 1);
		if (ret) {
			mutex_unlock(&inode->i_mutex);
			goto out;
		}
	}
M
Miao Xie 已提交
1911
	atomic_inc(&root->log_batch);
1912

C
Chris Mason 已提交
1913
	/*
1914 1915
	 * check the transaction that last modified this inode
	 * and see if its already been committed
C
Chris Mason 已提交
1916
	 */
1917 1918
	if (!BTRFS_I(inode)->last_trans) {
		mutex_unlock(&inode->i_mutex);
1919
		goto out;
1920
	}
1921

1922 1923 1924 1925 1926
	/*
	 * 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
1927
	smp_mb();
1928 1929
	if (btrfs_inode_in_log(inode, root->fs_info->generation) ||
	    BTRFS_I(inode)->last_trans <=
1930 1931
	    root->fs_info->last_trans_committed) {
		BTRFS_I(inode)->last_trans = 0;
J
Josef Bacik 已提交
1932 1933 1934 1935 1936 1937 1938 1939

		/*
		 * 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);
1940
		mutex_unlock(&inode->i_mutex);
1941 1942 1943 1944
		goto out;
	}

	/*
1945 1946
	 * ok we haven't committed the transaction yet, lets do a commit
	 */
1947
	if (file->private_data)
S
Sage Weil 已提交
1948 1949
		btrfs_ioctl_trans_end(file);

1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960
	/*
	 * We use start here because we will need to wait on the IO to complete
	 * in btrfs_sync_log, which could require joining a transaction (for
	 * example checking cross references in the nocow path).  If we use join
	 * here we could get into a situation where we're waiting on IO to
	 * happen that is blocked on a transaction trying to commit.  With start
	 * we inc the extwriter counter, so we wait for all extwriters to exit
	 * before we start blocking join'ers.  This comment is to keep somebody
	 * from thinking they are super smart and changing this to
	 * btrfs_join_transaction *cough*Josef*cough*.
	 */
1961 1962 1963
	trans = btrfs_start_transaction(root, 0);
	if (IS_ERR(trans)) {
		ret = PTR_ERR(trans);
1964
		mutex_unlock(&inode->i_mutex);
C
Chris Mason 已提交
1965 1966
		goto out;
	}
1967
	trans->sync = true;
1968

1969 1970 1971
	btrfs_init_log_ctx(&ctx);

	ret = btrfs_log_dentry_safe(trans, root, dentry, &ctx);
1972
	if (ret < 0) {
1973 1974
		/* Fallthrough and commit/free transaction. */
		ret = 1;
1975
	}
C
Chris Mason 已提交
1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986

	/* 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.
	 */
1987
	mutex_unlock(&inode->i_mutex);
C
Chris Mason 已提交
1988

1989
	if (ret != BTRFS_NO_LOG_SYNC) {
1990
		if (!ret) {
1991
			ret = btrfs_sync_log(trans, root, &ctx);
1992
			if (!ret) {
1993
				ret = btrfs_end_transaction(trans, root);
1994
				goto out;
1995
			}
1996
		}
1997 1998 1999 2000 2001 2002 2003
		if (!full_sync) {
			ret = btrfs_wait_ordered_range(inode, start,
						       end - start + 1);
			if (ret)
				goto out;
		}
		ret = btrfs_commit_transaction(trans, root);
2004 2005
	} else {
		ret = btrfs_end_transaction(trans, root);
2006
	}
C
Chris Mason 已提交
2007
out:
2008
	return ret > 0 ? -EIO : ret;
C
Chris Mason 已提交
2009 2010
}

2011
static const struct vm_operations_struct btrfs_file_vm_ops = {
2012
	.fault		= filemap_fault,
C
Chris Mason 已提交
2013
	.page_mkwrite	= btrfs_page_mkwrite,
2014
	.remap_pages	= generic_file_remap_pages,
C
Chris Mason 已提交
2015 2016 2017 2018
};

static int btrfs_file_mmap(struct file	*filp, struct vm_area_struct *vma)
{
M
Miao Xie 已提交
2019 2020 2021 2022 2023
	struct address_space *mapping = filp->f_mapping;

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

C
Chris Mason 已提交
2024
	file_accessed(filp);
M
Miao Xie 已提交
2025 2026
	vma->vm_ops = &btrfs_file_vm_ops;

C
Chris Mason 已提交
2027 2028 2029
	return 0;
}

J
Josef Bacik 已提交
2030 2031 2032 2033 2034 2035 2036 2037 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
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;

2070 2071 2072
	if (btrfs_fs_incompat(root->fs_info, NO_HOLES))
		goto out;

J
Josef Bacik 已提交
2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102
	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;
2103
		btrfs_set_item_key_safe(root, path, &key);
J
Josef Bacik 已提交
2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132
		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;
J
Josef Bacik 已提交
2133
		hole_em->ram_bytes = hole_em->len;
J
Josef Bacik 已提交
2134 2135 2136 2137
		hole_em->orig_start = offset;

		hole_em->block_start = EXTENT_MAP_HOLE;
		hole_em->block_len = 0;
2138
		hole_em->orig_block_len = 0;
J
Josef Bacik 已提交
2139 2140 2141 2142 2143 2144 2145
		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);
J
Josef Bacik 已提交
2146
			ret = add_extent_mapping(em_tree, hole_em, 1);
J
Josef Bacik 已提交
2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164
			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
2165 2166 2167
	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
2168 2169 2170 2171 2172
	u64 cur_offset = lockstart;
	u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
	u64 drop_end;
	int ret = 0;
	int err = 0;
2173
	int rsv_count;
2174 2175
	bool same_page = ((offset >> PAGE_CACHE_SHIFT) ==
			  ((offset + len - 1) >> PAGE_CACHE_SHIFT));
2176
	bool no_holes = btrfs_fs_incompat(root->fs_info, NO_HOLES);
2177
	u64 ino_size = round_up(inode->i_size, PAGE_CACHE_SIZE);
J
Josef Bacik 已提交
2178

2179 2180 2181
	ret = btrfs_wait_ordered_range(inode, offset, len);
	if (ret)
		return ret;
J
Josef Bacik 已提交
2182 2183

	mutex_lock(&inode->i_mutex);
2184 2185 2186 2187
	/*
	 * 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
2188 2189 2190 2191 2192
	/*
	 * 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) {
2193
		if (offset < ino_size)
2194
			ret = btrfs_truncate_page(inode, offset, len, 0);
J
Josef Bacik 已提交
2195 2196 2197 2198 2199
		mutex_unlock(&inode->i_mutex);
		return ret;
	}

	/* zero back part of the first page */
2200
	if (offset < ino_size) {
2201 2202 2203 2204 2205
		ret = btrfs_truncate_page(inode, offset, 0, 0);
		if (ret) {
			mutex_unlock(&inode->i_mutex);
			return ret;
		}
J
Josef Bacik 已提交
2206 2207 2208
	}

	/* zero the front end of the last page */
2209
	if (offset + len < ino_size) {
M
Miao Xie 已提交
2210 2211 2212 2213 2214
		ret = btrfs_truncate_page(inode, offset + len, 0, 1);
		if (ret) {
			mutex_unlock(&inode->i_mutex);
			return ret;
		}
J
Josef Bacik 已提交
2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236
	}

	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 ||
2237
		    (ordered->file_offset + ordered->len <= lockstart ||
J
Josef Bacik 已提交
2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249
		     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);
2250 2251 2252 2253 2254 2255
		ret = btrfs_wait_ordered_range(inode, lockstart,
					       lockend - lockstart + 1);
		if (ret) {
			mutex_unlock(&inode->i_mutex);
			return ret;
		}
J
Josef Bacik 已提交
2256 2257 2258 2259 2260 2261 2262 2263
	}

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

2264
	rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
J
Josef Bacik 已提交
2265 2266 2267 2268 2269 2270 2271 2272 2273 2274
	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
2275
	 * 1 - adding the hole extent if no_holes isn't set
J
Josef Bacik 已提交
2276
	 */
2277 2278
	rsv_count = no_holes ? 2 : 3;
	trans = btrfs_start_transaction(root, rsv_count);
J
Josef Bacik 已提交
2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291
	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,
2292
					   &drop_end, 1, 0, 0, NULL);
J
Josef Bacik 已提交
2293 2294 2295 2296 2297
		if (ret != -ENOSPC)
			break;

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

2298 2299 2300 2301 2302 2303 2304
		if (cur_offset < ino_size) {
			ret = fill_holes(trans, inode, path, cur_offset,
					 drop_end);
			if (ret) {
				err = ret;
				break;
			}
J
Josef Bacik 已提交
2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315
		}

		cur_offset = drop_end;

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

		btrfs_end_transaction(trans, root);
2316
		btrfs_btree_balance_dirty(root);
J
Josef Bacik 已提交
2317

2318
		trans = btrfs_start_transaction(root, rsv_count);
J
Josef Bacik 已提交
2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336
		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;
2337 2338 2339 2340 2341 2342
	if (cur_offset < ino_size) {
		ret = fill_holes(trans, inode, path, cur_offset, drop_end);
		if (ret) {
			err = ret;
			goto out_trans;
		}
J
Josef Bacik 已提交
2343 2344 2345 2346 2347 2348
	}

out_trans:
	if (!trans)
		goto out_free;

2349 2350 2351
	inode_inc_iversion(inode);
	inode->i_mtime = inode->i_ctime = CURRENT_TIME;

J
Josef Bacik 已提交
2352 2353 2354
	trans->block_rsv = &root->fs_info->trans_block_rsv;
	ret = btrfs_update_inode(trans, root, inode);
	btrfs_end_transaction(trans, root);
2355
	btrfs_btree_balance_dirty(root);
J
Josef Bacik 已提交
2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367
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;
}

2368 2369 2370
static long btrfs_fallocate(struct file *file, int mode,
			    loff_t offset, loff_t len)
{
A
Al Viro 已提交
2371
	struct inode *inode = file_inode(file);
2372
	struct extent_state *cached_state = NULL;
2373
	struct btrfs_root *root = BTRFS_I(inode)->root;
2374 2375 2376 2377 2378 2379 2380
	u64 cur_offset;
	u64 last_byte;
	u64 alloc_start;
	u64 alloc_end;
	u64 alloc_hint = 0;
	u64 locked_end;
	struct extent_map *em;
2381
	int blocksize = BTRFS_I(inode)->root->sectorsize;
2382 2383
	int ret;

2384 2385
	alloc_start = round_down(offset, blocksize);
	alloc_end = round_up(offset + len, blocksize);
2386

J
Josef Bacik 已提交
2387 2388
	/* Make sure we aren't being give some crap mode */
	if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
2389 2390
		return -EOPNOTSUPP;

J
Josef Bacik 已提交
2391 2392 2393
	if (mode & FALLOC_FL_PUNCH_HOLE)
		return btrfs_punch_hole(inode, offset, len);

2394 2395 2396 2397
	/*
	 * Make sure we have enough space before we do the
	 * allocation.
	 */
2398
	ret = btrfs_check_data_free_space(inode, alloc_end - alloc_start);
2399 2400
	if (ret)
		return ret;
2401 2402 2403 2404 2405
	if (root->fs_info->quota_enabled) {
		ret = btrfs_qgroup_reserve(root, alloc_end - alloc_start);
		if (ret)
			goto out_reserve_fail;
	}
2406

2407 2408 2409 2410 2411 2412
	mutex_lock(&inode->i_mutex);
	ret = inode_newsize_ok(inode, alloc_end);
	if (ret)
		goto out;

	if (alloc_start > inode->i_size) {
2413 2414
		ret = btrfs_cont_expand(inode, i_size_read(inode),
					alloc_start);
2415 2416
		if (ret)
			goto out;
2417 2418 2419 2420 2421 2422 2423 2424 2425
	} else {
		/*
		 * If we are fallocating from the end of the file onward we
		 * need to zero out the end of the page if i_size lands in the
		 * middle of a page.
		 */
		ret = btrfs_truncate_page(inode, inode->i_size, 0, 0);
		if (ret)
			goto out;
2426 2427
	}

2428 2429 2430 2431
	/*
	 * wait for ordered IO before we have any locks.  We'll loop again
	 * below with the locks held.
	 */
2432 2433 2434 2435
	ret = btrfs_wait_ordered_range(inode, alloc_start,
				       alloc_end - alloc_start);
	if (ret)
		goto out;
2436

2437 2438 2439 2440 2441 2442 2443 2444
	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,
2445
				 locked_end, 0, &cached_state);
2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458
		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
			 */
2459 2460 2461 2462
			ret = btrfs_wait_ordered_range(inode, alloc_start,
						       alloc_end - alloc_start);
			if (ret)
				goto out;
2463 2464 2465 2466 2467 2468 2469 2470 2471
		} else {
			if (ordered)
				btrfs_put_ordered_extent(ordered);
			break;
		}
	}

	cur_offset = alloc_start;
	while (1) {
2472 2473
		u64 actual_end;

2474 2475
		em = btrfs_get_extent(inode, NULL, 0, cur_offset,
				      alloc_end - cur_offset, 0);
2476 2477 2478 2479 2480 2481 2482
		if (IS_ERR_OR_NULL(em)) {
			if (!em)
				ret = -ENOMEM;
			else
				ret = PTR_ERR(em);
			break;
		}
2483
		last_byte = min(extent_map_end(em), alloc_end);
2484
		actual_end = min_t(u64, extent_map_end(em), offset + len);
2485
		last_byte = ALIGN(last_byte, blocksize);
2486

2487 2488 2489 2490 2491 2492 2493 2494
		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);
2495

2496 2497 2498 2499
			if (ret < 0) {
				free_extent_map(em);
				break;
			}
2500 2501 2502 2503 2504 2505 2506 2507 2508 2509
		} 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);
2510 2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522
		}
		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);
2523 2524 2525
	if (root->fs_info->quota_enabled)
		btrfs_qgroup_free(root, alloc_end - alloc_start);
out_reserve_fail:
2526
	/* Let go of our reservation. */
2527
	btrfs_free_reserved_data_space(inode, alloc_end - alloc_start);
2528 2529 2530
	return ret;
}

2531
static int find_desired_extent(struct inode *inode, loff_t *offset, int whence)
J
Josef Bacik 已提交
2532 2533
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
2534
	struct extent_map *em = NULL;
J
Josef Bacik 已提交
2535 2536 2537 2538 2539 2540 2541 2542 2543 2544 2545
	struct extent_state *cached_state = NULL;
	u64 lockstart = *offset;
	u64 lockend = i_size_read(inode);
	u64 start = *offset;
	u64 len = i_size_read(inode);
	int ret = 0;

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

L
Liu Bo 已提交
2546
	lockend--;
J
Josef Bacik 已提交
2547 2548 2549 2550 2551 2552 2553
	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,
2554
			 &cached_state);
J
Josef Bacik 已提交
2555

2556
	while (start < inode->i_size) {
J
Josef Bacik 已提交
2557 2558
		em = btrfs_get_extent_fiemap(inode, NULL, 0, start, len, 0);
		if (IS_ERR(em)) {
2559
			ret = PTR_ERR(em);
2560
			em = NULL;
J
Josef Bacik 已提交
2561 2562 2563
			break;
		}

2564 2565 2566 2567 2568 2569 2570 2571
		if (whence == SEEK_HOLE &&
		    (em->block_start == EXTENT_MAP_HOLE ||
		     test_bit(EXTENT_FLAG_PREALLOC, &em->flags)))
			break;
		else if (whence == SEEK_DATA &&
			   (em->block_start != EXTENT_MAP_HOLE &&
			    !test_bit(EXTENT_FLAG_PREALLOC, &em->flags)))
			break;
J
Josef Bacik 已提交
2572 2573 2574

		start = em->start + em->len;
		free_extent_map(em);
2575
		em = NULL;
J
Josef Bacik 已提交
2576 2577
		cond_resched();
	}
2578 2579 2580 2581 2582 2583 2584
	free_extent_map(em);
	if (!ret) {
		if (whence == SEEK_DATA && start >= inode->i_size)
			ret = -ENXIO;
		else
			*offset = min_t(loff_t, start, inode->i_size);
	}
J
Josef Bacik 已提交
2585 2586 2587 2588 2589
	unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
			     &cached_state, GFP_NOFS);
	return ret;
}

2590
static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int whence)
J
Josef Bacik 已提交
2591 2592 2593 2594 2595
{
	struct inode *inode = file->f_mapping->host;
	int ret;

	mutex_lock(&inode->i_mutex);
2596
	switch (whence) {
J
Josef Bacik 已提交
2597 2598
	case SEEK_END:
	case SEEK_CUR:
2599
		offset = generic_file_llseek(file, offset, whence);
J
Josef Bacik 已提交
2600 2601 2602
		goto out;
	case SEEK_DATA:
	case SEEK_HOLE:
2603 2604 2605 2606 2607
		if (offset >= i_size_read(inode)) {
			mutex_unlock(&inode->i_mutex);
			return -ENXIO;
		}

2608
		ret = find_desired_extent(inode, &offset, whence);
J
Josef Bacik 已提交
2609 2610 2611 2612 2613 2614
		if (ret) {
			mutex_unlock(&inode->i_mutex);
			return ret;
		}
	}

J
Jie Liu 已提交
2615
	offset = vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
J
Josef Bacik 已提交
2616 2617 2618 2619 2620
out:
	mutex_unlock(&inode->i_mutex);
	return offset;
}

2621
const struct file_operations btrfs_file_operations = {
J
Josef Bacik 已提交
2622
	.llseek		= btrfs_file_llseek,
C
Chris Mason 已提交
2623
	.read		= do_sync_read,
2624
	.write		= do_sync_write,
C
Chris Mason 已提交
2625
	.aio_read       = generic_file_aio_read,
C
Chris Mason 已提交
2626
	.splice_read	= generic_file_splice_read,
2627
	.aio_write	= btrfs_file_aio_write,
C
Chris Mason 已提交
2628
	.mmap		= btrfs_file_mmap,
C
Chris Mason 已提交
2629
	.open		= generic_file_open,
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	.release	= btrfs_release_file,
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	.fsync		= btrfs_sync_file,
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	.fallocate	= btrfs_fallocate,
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	.unlocked_ioctl	= btrfs_ioctl,
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#ifdef CONFIG_COMPAT
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	.compat_ioctl	= btrfs_ioctl,
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#endif
};
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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;
}