[PATCH] btrfs: Remove redundant initialization of slot

[PATCH] btrfs: Remove redundant initialization of slot

[Jiapeng Chong]

slot is being initialized to path->slots[0] but this is never
read as slot is overwritten later on. Remove the redundant
initialization.

Cleans up the following clang-analyzer warning:

fs/btrfs/tree-log.c:6125:7: warning: Value stored to 'slot' during its
initialization is never read [clang-analyzer-deadcode.DeadStores].

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
---
 fs/btrfs/tree-log.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 9165486b554e..c083562a3334 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -6122,7 +6122,7 @@ static int log_new_ancestors(struct btrfs_trans_handle *trans,
 	while (true) {
 		struct btrfs_fs_info *fs_info = root->fs_info;
 		struct extent_buffer *leaf = path->nodes[0];
-		int slot = path->slots[0];
+		int slot;
 		struct btrfs_key search_key;
 		struct inode *inode;
 		u64 ino;
-- 
2.20.1.7.g153144c

Re: [PATCH] btrfs: Remove redundant initialization of slot

[Qu Wenruo]

On 2021/12/31 20:23, Jiapeng Chong wrote:
> slot is being initialized to path->slots[0] but this is never
> read as slot is overwritten later on. Remove the redundant
> initialization.
>
> Cleans up the following clang-analyzer warning:
>
> fs/btrfs/tree-log.c:6125:7: warning: Value stored to 'slot' during its
> initialization is never read [clang-analyzer-deadcode.DeadStores].
>
> Reported-by: Abaci Robot <abaci@linux.alibaba.com>
> Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
> ---
>   fs/btrfs/tree-log.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
> index 9165486b554e..c083562a3334 100644
> --- a/fs/btrfs/tree-log.c
> +++ b/fs/btrfs/tree-log.c
> @@ -6122,7 +6122,7 @@ static int log_new_ancestors(struct btrfs_trans_handle *trans,
>   	while (true) {
>   		struct btrfs_fs_info *fs_info = root->fs_info;
>   		struct extent_buffer *leaf = path->nodes[0];
> -		int slot = path->slots[0];
> +		int slot;

If you're cleaning up slot, then why not also cleaning up leaf?

And again, no feedback no matter what on other patches from you, and
still CC to maintainers.


>   		struct btrfs_key search_key;
>   		struct inode *inode;
>   		u64 ino;

Re: [PATCH] btrfs: Remove redundant initialization of slot

[David Sterba]

On Fri, Dec 31, 2021 at 09:07:45PM +0800, Qu Wenruo wrote:
> 
> 
> On 2021/12/31 20:23, Jiapeng Chong wrote:
> > slot is being initialized to path->slots[0] but this is never
> > read as slot is overwritten later on. Remove the redundant
> > initialization.
> >
> > Cleans up the following clang-analyzer warning:
> >
> > fs/btrfs/tree-log.c:6125:7: warning: Value stored to 'slot' during its
> > initialization is never read [clang-analyzer-deadcode.DeadStores].
> >
> > Reported-by: Abaci Robot <abaci@linux.alibaba.com>
> > Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
> > ---
> >   fs/btrfs/tree-log.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
> > index 9165486b554e..c083562a3334 100644
> > --- a/fs/btrfs/tree-log.c
> > +++ b/fs/btrfs/tree-log.c
> > @@ -6122,7 +6122,7 @@ static int log_new_ancestors(struct btrfs_trans_handle *trans,
> >   	while (true) {
> >   		struct btrfs_fs_info *fs_info = root->fs_info;
> >   		struct extent_buffer *leaf = path->nodes[0];
> > -		int slot = path->slots[0];
> > +		int slot;
> 
> If you're cleaning up slot, then why not also cleaning up leaf?

Yes, the variable leaf does not need to be initialized as well, both
should be cleaned up in the same patch.

> And again, no feedback no matter what on other patches from you, and
> still CC to maintainers.

It's better to add the CCs than not, don't worry about that.