2022-01-14 10:42:00

by Jiapeng Chong

Subject: [PATCH] btrfs: zoned: Remove redundant initialization of to_add

to_add is being initialized to len but this is never read as
to_add is overwritten later on. Remove the redundant
initialization.

Cleans up the following clang-analyzer warning:

fs/btrfs/extent-tree.c:2769:8: warning: Value stored to 'to_add' 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/extent-tree.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index d89273c4b6b8..37117b62d005 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -2766,7 +2766,7 @@ static int unpin_extent_range(struct btrfs_fs_info *fs_info,
spin_unlock(&cache->lock);
if (!readonly && return_free_space &&
global_rsv->space_info == space_info) {
- u64 to_add = len;
+ u64 to_add;

spin_lock(&global_rsv->lock);
if (!global_rsv->full) {
--
2.20.1.7.g153144c

2022-01-14 11:06:09

by Nikolay Borisov

Subject: Re: [PATCH] btrfs: zoned: Remove redundant initialization of to_add

On 14.01.22 г. 12:41, Jiapeng Chong wrote:
> to_add is being initialized to len but this is never read as
> to_add is overwritten later on. Remove the redundant
> initialization.
>
> Cleans up the following clang-analyzer warning:
>
> fs/btrfs/extent-tree.c:2769:8: warning: Value stored to 'to_add' during
> its initialization is never read [clang-analyzer-deadcode.DeadStores].

To make it even better it would be good if to_add is define within the
if (!global_rsv->full) branch.

>
> Reported-by: Abaci Robot <[email protected]>
> Signed-off-by: Jiapeng Chong <[email protected]>
> ---
> fs/btrfs/extent-tree.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
> index d89273c4b6b8..37117b62d005 100644
> --- a/fs/btrfs/extent-tree.c
> +++ b/fs/btrfs/extent-tree.c
> @@ -2766,7 +2766,7 @@ static int unpin_extent_range(struct btrfs_fs_info *fs_info,
> spin_unlock(&cache->lock);
> if (!readonly && return_free_space &&
> global_rsv->space_info == space_info) {
> - u64 to_add = len;
> + u64 to_add;
>
> spin_lock(&global_rsv->lock);
> if (!global_rsv->full) {
>