From: Christoph Hellwig <hch@lst.de>
Date: Tue, 27 Jun 2023 08:13:23 +0200
Subject: [PATCH] btrfs: be a bit more careful when setting mirror_num_ret in
btrfs_map_block
References: bsc#1012628
Patch-mainline: 6.4.7
Git-commit: 4e7de35eb7d1a1d4f2dda15f39fbedd4798a0b8d
[ 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@linaro.org>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
fs/btrfs/volumes.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 5ec00081..436e15e3 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -6399,7 +6399,8 @@ int __btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
(!need_full_stripe(op) || !dev_replace_is_ongoing ||
!dev_replace->tgtdev)) {
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;
goto out;
--
2.35.3