2019-06-16 07:04:16

by Christophe JAILLET

Subject: [PATCH] scsi: tcmu: Simplify 'tcmu_update_uio_info()'

Use 'kasprintf()' instead of:
- snprintf(NULL, 0...
- kmalloc(...
- snprintf(...

This is less verbose and saves 7 bytes (i.e. the space for '/(null)') if
'udev->dev_config' is NULL.

Signed-off-by: Christophe JAILLET <[email protected]>
---
drivers/target/target_core_user.c | 16 +++++++---------
1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
index b43d6385a1a0..04eda111920e 100644
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -1824,20 +1824,18 @@ static int tcmu_update_uio_info(struct tcmu_dev *udev)
{
struct tcmu_hba *hba = udev->hba->hba_ptr;
struct uio_info *info;
- size_t size, used;
char *str;

info = &udev->uio_info;
- size = snprintf(NULL, 0, "tcm-user/%u/%s/%s", hba->host_id, udev->name,
- udev->dev_config);
- size += 1; /* for \0 */
- str = kmalloc(size, GFP_KERNEL);
- if (!str)
- return -ENOMEM;

- used = snprintf(str, size, "tcm-user/%u/%s", hba->host_id, udev->name);
if (udev->dev_config[0])
- snprintf(str + used, size - used, "/%s", udev->dev_config);
+ str = kasprintf(GFP_KERNEL, "tcm-user/%u/%s/%s", hba->host_id,
+ udev->name, udev->dev_config);
+ else
+ str = kasprintf(GFP_KERNEL, "tcm-user/%u/%s", hba->host_id,
+ udev->name);
+ if (!str)
+ return -ENOMEM;

/* If the old string exists, free it */
kfree(info->name);
--
2.20.1

2019-06-18 22:44:39

by Mike Christie

Subject: Re: [PATCH] scsi: tcmu: Simplify 'tcmu_update_uio_info()'

On 06/16/2019 02:02 AM, Christophe JAILLET wrote:
> Use 'kasprintf()' instead of:
> - snprintf(NULL, 0...
> - kmalloc(...
> - snprintf(...
>
> This is less verbose and saves 7 bytes (i.e. the space for '/(null)') if
> 'udev->dev_config' is NULL.
>
> Signed-off-by: Christophe JAILLET <[email protected]>
> ---
> drivers/target/target_core_user.c | 16 +++++++---------
> 1 file changed, 7 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
> index b43d6385a1a0..04eda111920e 100644
> --- a/drivers/target/target_core_user.c
> +++ b/drivers/target/target_core_user.c
> @@ -1824,20 +1824,18 @@ static int tcmu_update_uio_info(struct tcmu_dev *udev)
> {
> struct tcmu_hba *hba = udev->hba->hba_ptr;
> struct uio_info *info;
> - size_t size, used;
> char *str;
>
> info = &udev->uio_info;
> - size = snprintf(NULL, 0, "tcm-user/%u/%s/%s", hba->host_id, udev->name,
> - udev->dev_config);
> - size += 1; /* for \0 */
> - str = kmalloc(size, GFP_KERNEL);
> - if (!str)
> - return -ENOMEM;
>
> - used = snprintf(str, size, "tcm-user/%u/%s", hba->host_id, udev->name);
> if (udev->dev_config[0])
> - snprintf(str + used, size - used, "/%s", udev->dev_config);
> + str = kasprintf(GFP_KERNEL, "tcm-user/%u/%s/%s", hba->host_id,
> + udev->name, udev->dev_config);
> + else
> + str = kasprintf(GFP_KERNEL, "tcm-user/%u/%s", hba->host_id,
> + udev->name);
> + if (!str)
> + return -ENOMEM;
>
> /* If the old string exists, free it */
> kfree(info->name);
>

Thanks.

Acked-by: Mike Christie <[email protected]>

2019-06-19 01:11:07

by Martin K. Petersen

Subject: Re: [PATCH] scsi: tcmu: Simplify 'tcmu_update_uio_info()'

Christophe,

> Use 'kasprintf()' instead of:
> - snprintf(NULL, 0...
> - kmalloc(...
> - snprintf(...
>
> This is less verbose and saves 7 bytes (i.e. the space for '/(null)') if
> 'udev->dev_config' is NULL.

Applied to 5.3/scsi-queue. Thanks!

--
Martin K. Petersen Oracle Linux Engineering