[PATCH v2 3/8] nvmet/fc: Use sgl_alloc() and sgl_free()

[Bart Van Assche]

Use the sgl_alloc() and sgl_free() functions instead of open coding
these functions.

Signed-off-by: Bart Van Assche <bart.vanass...@wdc.com>
Reviewed-by: Johannes Thumshirn <jthumsh...@suse.de>
Cc: Keith Busch <keith.bu...@intel.com>
Cc: Christoph Hellwig <h...@lst.de>
Cc: James Smart <james.sm...@broadcom.com>
Cc: Sagi Grimberg <s...@grimberg.me>
---
 drivers/nvme/target/Kconfig |  1 +
 drivers/nvme/target/fc.c    | 36 ++----------------------------------
 2 files changed, 3 insertions(+), 34 deletions(-)

diff --git a/drivers/nvme/target/Kconfig b/drivers/nvme/target/Kconfig
index 03e4ab65fe77..4d9715630e21 100644
--- a/drivers/nvme/target/Kconfig
+++ b/drivers/nvme/target/Kconfig
@@ -39,6 +39,7 @@ config NVME_TARGET_FC
        tristate "NVMe over Fabrics FC target driver"
        depends on NVME_TARGET
        depends on HAS_DMA
+       select SGL_ALLOC
        help
          This enables the NVMe FC target support, which allows exporting NVMe
          devices over FC.
diff --git a/drivers/nvme/target/fc.c b/drivers/nvme/target/fc.c
index 58e010bdda3e..20f96038c272 100644
--- a/drivers/nvme/target/fc.c
+++ b/drivers/nvme/target/fc.c
@@ -1683,31 +1683,12 @@ static int
 nvmet_fc_alloc_tgt_pgs(struct nvmet_fc_fcp_iod *fod)
 {
        struct scatterlist *sg;
-       struct page *page;
        unsigned int nent;
-       u32 page_len, length;
-       int i = 0;
 
-       length = fod->total_length;
-       nent = DIV_ROUND_UP(length, PAGE_SIZE);
-       sg = kmalloc_array(nent, sizeof(struct scatterlist), GFP_KERNEL);
+       sg = sgl_alloc(fod->total_length, GFP_KERNEL, &nent);
        if (!sg)
                goto out;
 
-       sg_init_table(sg, nent);
-
-       while (length) {
-               page_len = min_t(u32, length, PAGE_SIZE);
-
-               page = alloc_page(GFP_KERNEL);
-               if (!page)
-                       goto out_free_pages;
-
-               sg_set_page(&sg[i], page, page_len, 0);
-               length -= page_len;
-               i++;
-       }
-
        fod->data_sg = sg;
        fod->data_sg_cnt = nent;
        fod->data_sg_cnt = fc_dma_map_sg(fod->tgtport->dev, sg, nent,
@@ -1717,14 +1698,6 @@ nvmet_fc_alloc_tgt_pgs(struct nvmet_fc_fcp_iod *fod)
 
        return 0;
 
-out_free_pages:
-       while (i > 0) {
-               i--;
-               __free_page(sg_page(&sg[i]));
-       }
-       kfree(sg);
-       fod->data_sg = NULL;
-       fod->data_sg_cnt = 0;
 out:
        return NVME_SC_INTERNAL;
 }
@@ -1732,18 +1705,13 @@ nvmet_fc_alloc_tgt_pgs(struct nvmet_fc_fcp_iod *fod)
 static void
 nvmet_fc_free_tgt_pgs(struct nvmet_fc_fcp_iod *fod)
 {
-       struct scatterlist *sg;
-       int count;
-
        if (!fod->data_sg || !fod->data_sg_cnt)
                return;
 
        fc_dma_unmap_sg(fod->tgtport->dev, fod->data_sg, fod->data_sg_cnt,
                                ((fod->io_dir == NVMET_FCP_WRITE) ?
                                        DMA_FROM_DEVICE : DMA_TO_DEVICE));
-       for_each_sg(fod->data_sg, sg, fod->data_sg_cnt, count)
-               __free_page(sg_page(sg));
-       kfree(fod->data_sg);
+       sgl_free(fod->data_sg);
        fod->data_sg = NULL;
        fod->data_sg_cnt = 0;
 }
-- 
2.14.2