From: Josef Bacik Date: Fri, 13 Mar 2015 19:12:08 +0000 (-0400) Subject: Btrfs: fix merge delalloc logic X-Git-Tag: v4.0-rc5~13^2~7 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=8461a3de770477a9a7b8eeaebcc4804dbc26ca38;p=linux.git 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 Signed-off-by: Josef Bacik Signed-off-by: Chris Mason --- diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 91a87f53be3c..97b601bec326 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -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) {