Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit db804f23 authored by Li Zefan's avatar Li Zefan
Browse files

Btrfs: add pinned extents to on-disk free space cache correctly 



I got this while running xfstests:

[24256.836098] block group 317849600 has an wrong amount of free space
[24256.836100] btrfs: failed to load free space cache for block group 317849600

We should clamp the extent returned by find_first_extent_bit(),
so the start of the extent won't smaller than the start of the
block group.

Signed-off-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
parent d25223a0

fs/btrfs/free-space-cache.c

+20 −21
Original line number Diff line number Diff line
@@ -838,7 +838,7 @@ int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode, 
	struct io_ctl io_ctl;

	struct list_head bitmap_list;

	struct btrfs_key key;

	u64 start, end, len;

	u64 start, extent_start, extent_end, len;

	int entries = 0;

	int bitmaps = 0;

	int ret;
@@ -857,25 +857,12 @@ int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode, 
				     struct btrfs_free_cluster,

				     block_group_list);



	/*

	 * We shouldn't have switched the pinned extents yet so this is the

	 * right one

	 */

	unpin = root->fs_info->pinned_extents;



	/* Lock all pages first so we can lock the extent safely. */

	io_ctl_prepare_pages(&io_ctl, inode, 0);



	lock_extent_bits(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1,

			 0, &cached_state, GFP_NOFS);



	/*

	 * When searching for pinned extents, we need to start at our start

	 * offset.

	 */

	if (block_group)

		start = block_group->key.objectid;



	node = rb_first(&ctl->free_space_offset);

	if (!node && cluster) {

		node = rb_first(&cluster->root);
@@ -918,9 +905,20 @@ int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode, 
	 * We want to add any pinned extents to our free space cache

	 * so we don't leak the space

	 */



	/*

	 * We shouldn't have switched the pinned extents yet so this is the

	 * right one

	 */

	unpin = root->fs_info->pinned_extents;



	if (block_group)

		start = block_group->key.objectid;



	while (block_group && (start < block_group->key.objectid +

			       block_group->key.offset)) {

		ret = find_first_extent_bit(unpin, start, &start, &end,

		ret = find_first_extent_bit(unpin, start,

					    &extent_start, &extent_end,

					    EXTENT_DIRTY);

		if (ret) {

			ret = 0;
@@ -928,20 +926,21 @@ int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode, 
		}



		/* This pinned extent is out of our range */

		if (start >= block_group->key.objectid +

		if (extent_start >= block_group->key.objectid +

		    block_group->key.offset)

			break;



		len = block_group->key.objectid +

			block_group->key.offset - start;

		len = min(len, end + 1 - start);

		extent_start = max(extent_start, start);

		extent_end = min(block_group->key.objectid +

				 block_group->key.offset, extent_end + 1);

		len = extent_end - extent_start;



		entries++;

		ret = io_ctl_add_entry(&io_ctl, start, len, NULL);

		ret = io_ctl_add_entry(&io_ctl, extent_start, len, NULL);

		if (ret)

			goto out_nospc;



		start = end + 1;

		start = extent_end;

	}



	/* Write out the bitmaps */