2022-01-22 00:53:27

by Jiapeng Chong

Subject: [PATCH] btrfs: scrub: Remove redundant initialization of increment

increment is being initialized to map->stripe_len but this is never
read as increment is overwritten later on. Remove the redundant
initialization.

Cleans up the following clang-analyzer warning:

fs/btrfs/scrub.c:3193:6: warning: Value stored to 'increment' during its
initialization is never read [clang-analyzer-deadcode.DeadStores].

Reported-by: Abaci Robot <[email protected]>
Signed-off-by: Jiapeng Chong <[email protected]>
---
fs/btrfs/scrub.c | 1 -
1 file changed, 1 deletion(-)

diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index 2e9a322773f2..38f5666eff14 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -3209,7 +3209,6 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
offset = 0;
nstripes = div64_u64(dev_extent_len, map->stripe_len);
mirror_num = 1;
- increment = map->stripe_len;
if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
offset = map->stripe_len * stripe_index;
increment = map->stripe_len * map->num_stripes;
--
2.20.1.7.g153144c

2022-01-24 20:42:06

by David Sterba

Subject: Re: [PATCH] btrfs: scrub: Remove redundant initialization of increment

On Fri, Jan 21, 2022 at 07:42:24PM +0800, Jiapeng Chong wrote:
> increment is being initialized to map->stripe_len but this is never
> read as increment is overwritten later on. Remove the redundant
> initialization.

>
> Cleans up the following clang-analyzer warning:
>
> fs/btrfs/scrub.c:3193:6: warning: Value stored to 'increment' during its
> initialization is never read [clang-analyzer-deadcode.DeadStores].
>
> Reported-by: Abaci Robot <[email protected]>
> Signed-off-by: Jiapeng Chong <[email protected]>
> ---
> fs/btrfs/scrub.c | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
> index 2e9a322773f2..38f5666eff14 100644
> --- a/fs/btrfs/scrub.c
> +++ b/fs/btrfs/scrub.c
> @@ -3209,7 +3209,6 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
> offset = 0;
> nstripes = div64_u64(dev_extent_len, map->stripe_len);
> mirror_num = 1;
> - increment = map->stripe_len;

I'd rather remove the initialization at the declarataion, the other
values are initialized here so it's all in one place. As is's a minor
change I'll do that at commit time, no need to resend. Thanks.