From: Josef Bacik <josef@toxicpanda.com>
Date: Fri, 17 Jan 2020 09:07:38 -0500
Subject: btrfs: fix force usage in inc_block_group_ro
Git-commit: a7a63acc6575ded6f48ab293e275e8b903325e54
Patch-mainline: v5.6-rc1
References: bsc#1178897

For some reason we've translated the do_chunk_alloc that goes into
btrfs_inc_block_group_ro to force in inc_block_group_ro, but these are
two different things.

force for inc_block_group_ro is used when we are forcing the block group
read only no matter what, for example when the underlying chunk is
marked read only.  We need to not do the space check here as this block
group needs to be read only.

btrfs_inc_block_group_ro() has a do_chunk_alloc flag that indicates that
we need to pre-allocate a chunk before marking the block group read
only.  This has nothing to do with forcing, and in fact we _always_ want
to do the space check in this case, so unconditionally pass false for
force in this case.

Then fixup inc_block_group_ro to honor force as it's expected and
documented to do.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Acked-by: Nikolay Borisov <nborisov@suse.com>
---
 fs/btrfs/block-group.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -1194,7 +1194,7 @@ static int inc_block_group_ro(struct btr
 	 * Here we make sure if we mark this bg RO, we still have enough
 	 * free space as buffer.
 	 */
-	if (sinfo_used + num_bytes <= sinfo->total_bytes) {
+	if (force || (sinfo_used + num_bytes <= sinfo->total_bytes)) {
 		sinfo->bytes_readonly += num_bytes;
 		cache->ro++;
 		list_add_tail(&cache->ro_list, &sinfo->ro_bgs);