Btrfs: fix merge delalloc logic

My patch to properly count outstanding extents wrt MAX_EXTENT_SIZE introduced a
regression when re-dirtying already dirty areas.  We have logic in split to make
sure we are taking the largest space into account but didn't have it for merge,
so it was sometimes making us think we were turning a tiny extent into a huge
extent, when in reality we already had a huge extent and needed to use the other
side in our logic.  This fixes the regression that was reported by a user on
list.  Thanks,

Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
This commit is contained in:
Josef Bacik 2015-03-13 15:12:08 -04:00 committed by Chris Mason
parent 48da5f0a4c
commit 8461a3de77

View file

@ -1592,7 +1592,12 @@ static void btrfs_merge_extent_hook(struct inode *inode,
return;
old_size = other->end - other->start + 1;
new_size = old_size + (new->end - new->start + 1);
if (old_size < (new->end - new->start + 1))
old_size = (new->end - new->start + 1);
if (new->start > other->start)
new_size = new->end - other->start + 1;
else
new_size = other->end - new->start + 1;
/* we're not bigger than the max, unreserve the space and go */
if (new_size <= BTRFS_MAX_EXTENT_SIZE) {