2021-04-25 10:25:54

by Yang Li

Subject: [PATCH] fs/ntfs: drop unneeded assignment in ntfs_perform_write()

It is not required to initialize the local variable idx in
ntfs_perform_write(), the value is never actually read from
it.

make clang-analyzer on x86_64 allyesconfig reports:

fs/ntfs/file.c:1781:15: warning: Although the value stored to 'idx' is
used in the enclosing expression, the value is never actually read from
'idx'

Simplify the code and remove unneeded assignment to make clang-analyzer
happy.

Reported-by: Abaci Robot <[email protected]>
Signed-off-by: Yang Li <[email protected]>
---
fs/ntfs/file.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/ntfs/file.c b/fs/ntfs/file.c
index e5aab26..e39a26f 100644
--- a/fs/ntfs/file.c
+++ b/fs/ntfs/file.c
@@ -1774,11 +1774,11 @@ static ssize_t ntfs_perform_write(struct file *file, struct iov_iter *i,
last_vcn = -1;
do {
VCN vcn;
- pgoff_t idx, start_idx;
+ pgoff_t start_idx;
unsigned ofs, do_pages, u;
size_t copied;

- start_idx = idx = pos >> PAGE_SHIFT;
+ start_idx = pos >> PAGE_SHIFT;
ofs = pos & ~PAGE_MASK;
bytes = PAGE_SIZE - ofs;
do_pages = 1;
--
1.8.3.1

2021-04-27 18:56:05

by Nick Desaulniers

Subject: Re: [PATCH] fs/ntfs: drop unneeded assignment in ntfs_perform_write()

On Sun, Apr 25, 2021 at 3:16 AM Yang Li <[email protected]> wrote:
>
> It is not required to initialize the local variable idx in
> ntfs_perform_write(), the value is never actually read from
> it.
>
> make clang-analyzer on x86_64 allyesconfig reports:
>
> fs/ntfs/file.c:1781:15: warning: Although the value stored to 'idx' is
> used in the enclosing expression, the value is never actually read from
> 'idx'
>
> Simplify the code and remove unneeded assignment to make clang-analyzer
> happy.

Thank you for the patch.
Reviewed-by: Nick Desaulniers <[email protected]>
Is there someplace where I can learn more about "Abaci Robot?" I'm
happy to see it running clang-analyzer. :)

>
> Reported-by: Abaci Robot <[email protected]>
> Signed-off-by: Yang Li <[email protected]>
> ---
> fs/ntfs/file.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/fs/ntfs/file.c b/fs/ntfs/file.c
> index e5aab26..e39a26f 100644
> --- a/fs/ntfs/file.c
> +++ b/fs/ntfs/file.c
> @@ -1774,11 +1774,11 @@ static ssize_t ntfs_perform_write(struct file *file, struct iov_iter *i,
> last_vcn = -1;
> do {
> VCN vcn;
> - pgoff_t idx, start_idx;
> + pgoff_t start_idx;
> unsigned ofs, do_pages, u;
> size_t copied;
>
> - start_idx = idx = pos >> PAGE_SHIFT;
> + start_idx = pos >> PAGE_SHIFT;
> ofs = pos & ~PAGE_MASK;
> bytes = PAGE_SIZE - ofs;
> do_pages = 1;
> --
> 1.8.3.1
>
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--
Thanks,
~Nick Desaulniers