scsi: target/core: Use sg_alloc_table() instead of open-coding it

The purpose of sg_alloc_table() is to allocate and initialize an
sg-list. Use that function instead of open-coding it. This patch will
make it easier to share code for caching sg-list allocations between the
SCSI and NVMe target cores.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c
index f2c3b67..3d3568a 100644 (file)
--- a/drivers/target/target_core_sbc.c
+++ b/drivers/target/target_core_sbc.c
@@ -447,7 +447,8 @@ static sense_reason_t compare_and_write_callback(struct se_cmd *cmd, bool succes
                                                 int *post_ret)
 {
        struct se_device *dev = cmd->se_dev;
-       struct scatterlist *write_sg = NULL, *sg;
+       struct sg_table write_tbl = { };
+       struct scatterlist *write_sg, *sg;
        unsigned char *buf = NULL, *addr;
        struct sg_mapping_iter m;
        unsigned int offset = 0, len;
@@ -488,14 +489,12 @@ static sense_reason_t compare_and_write_callback(struct se_cmd *cmd, bool succes
                goto out;
        }
 
-       write_sg = kmalloc_array(cmd->t_data_nents, sizeof(*write_sg),
-                                GFP_KERNEL);
-       if (!write_sg) {
+       if (sg_alloc_table(&write_tbl, cmd->t_data_nents, GFP_KERNEL) < 0) {
                pr_err("Unable to allocate compare_and_write sg\n");
                ret = TCM_OUT_OF_RESOURCES;
                goto out;
        }
-       sg_init_table(write_sg, cmd->t_data_nents);
+       write_sg = write_tbl.sgl;
        /*
         * Setup verify and write data payloads from total NumberLBAs.
         */
@@ -591,7 +590,7 @@ out:
         * sbc_compare_and_write() before the original READ I/O submission.
         */
        up(&dev->caw_sem);
-       kfree(write_sg);
+       sg_free_table(&write_tbl);
        kfree(buf);
        return ret;
 }