[PATCH] null_blk: Use strscpy() instead of strscpy_pad() in null_add_dev()

Thorsten Blum posted 1 patch 10 months ago
drivers/block/null_blk/main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
[PATCH] null_blk: Use strscpy() instead of strscpy_pad() in null_add_dev()
Posted by Thorsten Blum 10 months ago
blk_mq_alloc_disk() already zero-initializes the destination buffer,
making strscpy() sufficient for safely copying the disk's name. The
additional NUL-padding performed by strscpy_pad() is unnecessary.

If the destination buffer has a fixed length, strscpy() automatically
determines its size using sizeof() when the argument is omitted. This
makes the explicit size argument unnecessary.

The source string is also NUL-terminated and meets the __must_be_cstr()
requirement of strscpy().

No functional changes intended.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
---
 drivers/block/null_blk/main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c
index 3bb9cee0a9b5..aa163ae9b2aa 100644
--- a/drivers/block/null_blk/main.c
+++ b/drivers/block/null_blk/main.c
@@ -2031,7 +2031,7 @@ static int null_add_dev(struct nullb_device *dev)
 	nullb->disk->minors = 1;
 	nullb->disk->fops = &null_ops;
 	nullb->disk->private_data = nullb;
-	strscpy_pad(nullb->disk->disk_name, nullb->disk_name, DISK_NAME_LEN);
+	strscpy(nullb->disk->disk_name, nullb->disk_name);
 
 	if (nullb->dev->zoned) {
 		rv = null_register_zoned_dev(nullb);
-- 
2.49.0
Re: [PATCH] null_blk: Use strscpy() instead of strscpy_pad() in null_add_dev()
Posted by Jens Axboe 10 months ago
On Thu, 10 Apr 2025 17:47:23 +0200, Thorsten Blum wrote:
> blk_mq_alloc_disk() already zero-initializes the destination buffer,
> making strscpy() sufficient for safely copying the disk's name. The
> additional NUL-padding performed by strscpy_pad() is unnecessary.
> 
> If the destination buffer has a fixed length, strscpy() automatically
> determines its size using sizeof() when the argument is omitted. This
> makes the explicit size argument unnecessary.
> 
> [...]

Applied, thanks!

[1/1] null_blk: Use strscpy() instead of strscpy_pad() in null_add_dev()
      commit: 3b607b75a345b1d808031bf1bb1038e4dac8d521

Best regards,
-- 
Jens Axboe
Re: [PATCH] null_blk: Use strscpy() instead of strscpy_pad() in null_add_dev()
Posted by Damien Le Moal 10 months ago
On 4/11/25 00:47, Thorsten Blum wrote:
> blk_mq_alloc_disk() already zero-initializes the destination buffer,
> making strscpy() sufficient for safely copying the disk's name. The
> additional NUL-padding performed by strscpy_pad() is unnecessary.
> 
> If the destination buffer has a fixed length, strscpy() automatically
> determines its size using sizeof() when the argument is omitted. This
> makes the explicit size argument unnecessary.
> 
> The source string is also NUL-terminated and meets the __must_be_cstr()
> requirement of strscpy().
> 
> No functional changes intended.
> 
> Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>

Reviewed-by: Damien Le Moal <dlemoal@kernel.org>

-- 
Damien Le Moal
Western Digital Research
Re: [PATCH] null_blk: Use strscpy() instead of strscpy_pad() in null_add_dev()
Posted by Zhu Yanjun 10 months ago
On 10.04.25 17:47, Thorsten Blum wrote:
> blk_mq_alloc_disk() already zero-initializes the destination buffer,
> making strscpy() sufficient for safely copying the disk's name. The
> additional NUL-padding performed by strscpy_pad() is unnecessary.
>
> If the destination buffer has a fixed length, strscpy() automatically

Looks good to me. The destination buffer is indeed has a fixed length, 
it is DISK_NAME_LEN.

Reviewed-by: Zhu Yanjun <yanjun.zhu@linux.dev>

Zhu Yanjun

> determines its size using sizeof() when the argument is omitted. This
> makes the explicit size argument unnecessary.
>
> The source string is also NUL-terminated and meets the __must_be_cstr()
> requirement of strscpy().
>
> No functional changes intended.
>
> Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
> ---
>   drivers/block/null_blk/main.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c
> index 3bb9cee0a9b5..aa163ae9b2aa 100644
> --- a/drivers/block/null_blk/main.c
> +++ b/drivers/block/null_blk/main.c
> @@ -2031,7 +2031,7 @@ static int null_add_dev(struct nullb_device *dev)
>   	nullb->disk->minors = 1;
>   	nullb->disk->fops = &null_ops;
>   	nullb->disk->private_data = nullb;
> -	strscpy_pad(nullb->disk->disk_name, nullb->disk_name, DISK_NAME_LEN);
> +	strscpy(nullb->disk->disk_name, nullb->disk_name);
>   
>   	if (nullb->dev->zoned) {
>   		rv = null_register_zoned_dev(nullb);

-- 
Best Regards,
Yanjun.Zhu