From: Christoph Hellwig <hch@xxxxxx>
[ Upstream commit 4e7de35eb7d1a1d4f2dda15f39fbedd4798a0b8d ]
The mirror_num_ret is allowed to be NULL, although it has to be set when
smap is set. Unfortunately that is not a well enough specifiable
invariant for static type checkers, so add a NULL check to make sure they
are fine.
Fixes: 03793cbbc80f ("btrfs: add fast path for single device io in __btrfs_map_block")
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Reviewed-by: Qu Wenruo <wqu@xxxxxxxx>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@xxxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/btrfs/volumes.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 7433ae929fdcb..2e0832d70406c 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -6595,11 +6595,13 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info,
if (patch_the_first_stripe_for_dev_replace) {
smap->dev = dev_replace->tgtdev;
smap->physical = physical_to_patch_in_first_stripe;
- *mirror_num_ret = map->num_stripes + 1;
+ if (mirror_num_ret)
+ *mirror_num_ret = map->num_stripes + 1;
} else {
set_io_stripe(smap, map, stripe_index, stripe_offset,
stripe_nr);
- *mirror_num_ret = mirror_num;
+ if (mirror_num_ret)
+ *mirror_num_ret = mirror_num;
}
*bioc_ret = NULL;
ret = 0;
--
2.39.2
