btrfs: Fix a data space underflow warning
Even with quota disabled, generic/127 will trigger a kernel warning by
underflow data space info.
The bug is caused by buffered write, which in case of short copy, the
start parameter for btrfs_delalloc_release_space() is wrong, and
round_up/down() in btrfs_delalloc_release() extents the range to page
aligned, decreasing one more page than expected.
This patch will fix it by passing correct start.
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 381be79..e6df6f1 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1604,12 +1604,17 @@
BTRFS_I(inode)->outstanding_extents++;
spin_unlock(&BTRFS_I(inode)->lock);
}
- if (only_release_metadata)
+ if (only_release_metadata) {
btrfs_delalloc_release_metadata(inode,
release_bytes);
- else
- btrfs_delalloc_release_space(inode, pos,
+ } else {
+ u64 __pos;
+
+ __pos = round_down(pos, root->sectorsize) +
+ (dirty_pages << PAGE_CACHE_SHIFT);
+ btrfs_delalloc_release_space(inode, __pos,
release_bytes);
+ }
}
release_bytes = dirty_pages << PAGE_CACHE_SHIFT;
