On 10/17/2017 12:49 AM, Bart Van Assche wrote:
> Use the sgl_alloc_order() and sgl_free() functions instead of open
> coding these functions.
>
> Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxx>
> Cc: Nicholas A. Bellinger <nab@xxxxxxxxxxxxxxx>
> Cc: Christoph Hellwig <hch@xxxxxx>
> Cc: Hannes Reinecke <hare@xxxxxxxx>
> Cc: Sagi Grimberg <sagi@xxxxxxxxxxx>
> ---
> drivers/target/Kconfig | 1 +
> drivers/target/target_core_transport.c | 46 +++-------------------------------
> 2 files changed, 5 insertions(+), 42 deletions(-)
>
> diff --git a/drivers/target/Kconfig b/drivers/target/Kconfig
> index e2bc99980f75..4c44d7bed01a 100644
> --- a/drivers/target/Kconfig
> +++ b/drivers/target/Kconfig
> @@ -5,6 +5,7 @@ menuconfig TARGET_CORE
> select CONFIGFS_FS
> select CRC_T10DIF
> select BLK_SCSI_REQUEST # only for scsi_command_size_tbl..
> + select SGL_ALLOC
> default n
> help
> Say Y or M here to enable the TCM Storage Engine and ConfigFS enabled
> diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
> index 836d552b0385..9bbd08be9d60 100644
> --- a/drivers/target/target_core_transport.c
> +++ b/drivers/target/target_core_transport.c
> @@ -2293,13 +2293,7 @@ static void target_complete_ok_work(struct work_struct *work)
>
> void target_free_sgl(struct scatterlist *sgl, int nents)
> {
> - struct scatterlist *sg;
> - int count;
> -
> - for_each_sg(sgl, sg, nents, count)
> - __free_page(sg_page(sg));
> -
> - kfree(sgl);
> + sgl_free(sgl);
> }
> EXPORT_SYMBOL(target_free_sgl);
>
> @@ -2423,42 +2417,10 @@ int
> target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
> bool zero_page, bool chainable)
> {
> - struct scatterlist *sg;
> - struct page *page;
> - gfp_t zero_flag = (zero_page) ? __GFP_ZERO : 0;
> - unsigned int nalloc, nent;
> - int i = 0;
> -
> - nalloc = nent = DIV_ROUND_UP(length, PAGE_SIZE);
> - if (chainable)
> - nalloc++;
> - sg = kmalloc_array(nalloc, sizeof(struct scatterlist), GFP_KERNEL);
> - if (!sg)
> - return -ENOMEM;
> + gfp_t gfp = GFP_KERNEL | (zero_page ? __GFP_ZERO : 0);
>
> - sg_init_table(sg, nalloc);
> -
> - while (length) {
> - u32 page_len = min_t(u32, length, PAGE_SIZE);
> - page = alloc_page(GFP_KERNEL | zero_flag);
> - if (!page)
> - goto out;
> -
> - sg_set_page(&sg[i], page, page_len, 0);
> - length -= page_len;
> - i++;
> - }
> - *sgl = sg;
> - *nents = nent;
> - return 0;
> -
> -out:
> - while (i > 0) {
> - i--;
> - __free_page(sg_page(&sg[i]));
> - }
> - kfree(sg);
> - return -ENOMEM;
> + *sgl = sgl_alloc_order(length, 0, chainable, gfp, nents);
> + return *sgl ? 0 : -ENOMEM;
> }
> EXPORT_SYMBOL(target_alloc_sgl);
>
> The calling convention from target_alloc_sgl() is decidedly dodgy.
Can't we convert it into returning the sgl, and remove the first parameter?
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
hare@xxxxxxx +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton
HRB 21284 (AG Nürnberg)
