Btrfs: fix autodefrag with compression
The autodefrag code skips defrag when two extents are adjacent. But one
big advantage for autodefrag is cutting down on the number of small
extents, even when they are adjacent. This commit changes it to defrag
all small extents.
Signed-off-by: Chris Mason <clm@fb.com>
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index fce6fd0e..a018ea4 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1019,8 +1019,10 @@
return false;
next = defrag_lookup_extent(inode, em->start + em->len);
- if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE ||
- (em->block_start + em->block_len == next->block_start))
+ if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)
+ ret = false;
+ else if ((em->block_start + em->block_len == next->block_start) &&
+ (em->block_len > 128 * 1024 && next->block_len > 128 * 1024))
ret = false;
free_extent_map(next);
@@ -1055,7 +1057,6 @@
}
next_mergeable = defrag_check_next_extent(inode, em);
-
/*
* we hit a real extent, if it is big or the next extent is not a
* real extent, don't bother defragging it