Re: [PATCH 1/4] scsi: target: file: use kmalloc() to allocate temporary protection buffer

[Hannes Reinecke]

On 6/30/26 12:54 PM, Mike Rapoport (Microsoft) wrote:
> fd_do_prot_unmap() uses __get_free_page() to allocate a temporary buffer
> that is used to invalidate protection info for the unmapped region by
> filling with 0xff pattern.
>
> This buffer can be allocated with kmalloc() as there's nothing special
> about it to go directly to the page allocator.
>
> kmalloc() provides a better API that does not require ugly casts and
> kfree() does not need to know the size of the freed object.
>
> Replace use of __get_free_page() with kmalloc().
>
> Link: https://lore.kernel.org/all/635405e4-9423-4a25-a6e7-e03c8ea0bcbe@xxxxxxxxxx
> Signed-off-by: Mike Rapoport (Microsoft) <rppt@xxxxxxxxxx>
> ---
>   drivers/target/target_core_file.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/target/target_core_file.c b/drivers/target/target_core_file.c
> index 62ced9f5102f..ab9824a4852f 100644
> --- a/drivers/target/target_core_file.c
> +++ b/drivers/target/target_core_file.c
> @@ -516,7 +516,7 @@ fd_do_prot_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
>   	void *buf;
>   	int rc;
>   
> -	buf = (void *)__get_free_page(GFP_KERNEL);
> +	buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
>   	if (!buf) {
>   		pr_err("Unable to allocate FILEIO prot buf\n");
>   		return -ENOMEM;
> @@ -524,7 +524,7 @@ fd_do_prot_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
>   
>   	rc = fd_do_prot_fill(cmd->se_dev, lba, nolb, buf, PAGE_SIZE);
>   
> -	free_page((unsigned long)buf);
> +	kfree(buf);
>   
>   	return rc;
>   }
Reviewed-by: Hannes Reinecke <hare@xxxxxxxxxx>

Cheers,

Hannes
--
Dr. Hannes Reinecke                  Kernel Storage Architect
hare@xxxxxxxx                               +49 911 74053 688
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