[PATCH 4.18 339/350] btrfs: reset max_extent_size properly

Greg Kroah-Hartman
2018-11-11T23:13:13Z

From: Josef Bacik <josef@toxicpanda.com>

commit 21a94f7acf0f748599ea552af5d9ee7d7e41c72f upstream.

If we use up our block group before allocating a new one we'll easily
get a max_extent_size that's set really really low, which will result in
a lot of fragmentation. We need to make sure we're resetting the
max_extent_size when we add a new chunk or add new space.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/btrfs/extent-tree.c | 2 ++
1 file changed, 2 insertions(+)

--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -4661,6 +4661,7 @@ again:
goto out;
} else {
ret = 1;
+ space_info->max_extent_size = 0;
}

space_info->force_alloc = CHUNK_ALLOC_NO_FORCE;
@@ -6576,6 +6577,7 @@ static int btrfs_free_reserved_bytes(str
space_info->bytes_readonly += num_bytes;
cache->reserved -= num_bytes;
space_info->bytes_reserved -= num_bytes;
+ space_info->max_extent_size = 0;

if (delalloc)
cache->delalloc_bytes -= num_bytes;