target: stop using blk_make_request

Using blk_rq_append_bio allows to append the bios to the request
directly instead of having to build up a list first, and also
allows to have a single code path for requests with or without
data attached to them.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

diff --git a/drivers/target/target_core_pscsi.c b/drivers/target/target_core_pscsi.c
index 81564c8..9125d93 100644 (file)
--- a/drivers/target/target_core_pscsi.c
+++ b/drivers/target/target_core_pscsi.c
@@ -876,19 +876,19 @@ static inline struct bio *pscsi_get_bio(int nr_vecs)
 
 static sense_reason_t
 pscsi_map_sg(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
-               enum dma_data_direction data_direction, struct bio **hbio)
+               struct request *req)
 {
        struct pscsi_dev_virt *pdv = PSCSI_DEV(cmd->se_dev);
-       struct bio *bio = NULL, *tbio = NULL;
+       struct bio *bio = NULL;
        struct page *page;
        struct scatterlist *sg;
        u32 data_len = cmd->data_length, i, len, bytes, off;
        int nr_pages = (cmd->data_length + sgl[0].offset +
                        PAGE_SIZE - 1) >> PAGE_SHIFT;
        int nr_vecs = 0, rc;
-       int rw = (data_direction == DMA_TO_DEVICE);
+       int rw = (cmd->data_direction == DMA_TO_DEVICE);
 
-       *hbio = NULL;
+       BUG_ON(!cmd->data_length);
 
        pr_debug("PSCSI: nr_pages: %d\n", nr_pages);
 
@@ -927,16 +927,6 @@ pscsi_map_sg(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
                                pr_debug("PSCSI: Allocated bio: %p,"
                                        " dir: %s nr_vecs: %d\n", bio,
                                        (rw) ? "rw" : "r", nr_vecs);
-                               /*
-                                * Set *hbio pointer to handle the case:
-                                * nr_pages > BIO_MAX_PAGES, where additional
-                                * bios need to be added to complete a given
-                                * command.
-                                */
-                               if (!*hbio)
-                                       *hbio = tbio = bio;
-                               else
-                                       tbio = tbio->bi_next = bio;
                        }
 
                        pr_debug("PSCSI: Calling bio_add_pc_page() i: %d"
@@ -955,11 +945,16 @@ pscsi_map_sg(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
                                pr_debug("PSCSI: Reached bio->bi_vcnt max:"
                                        " %d i: %d bio: %p, allocating another"
                                        " bio\n", bio->bi_vcnt, i, bio);
+
+                               rc = blk_rq_append_bio(req, bio);
+                               if (rc) {
+                                       pr_err("pSCSI: failed to append bio\n");
+                                       goto fail;
+                               }
+
                                /*
                                 * Clear the pointer so that another bio will
-                                * be allocated with pscsi_get_bio() above, the
-                                * current bio has already been set *tbio and
-                                * bio->bi_next.
+                                * be allocated with pscsi_get_bio() above.
                                 */
                                bio = NULL;
                        }
@@ -968,13 +963,16 @@ pscsi_map_sg(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
                }
        }
 
+       if (bio) {
+               rc = blk_rq_append_bio(req, bio);
+               if (rc) {
+                       pr_err("pSCSI: failed to append bio\n");
+                       goto fail;
+               }
+       }
+
        return 0;
 fail:
-       while (*hbio) {
-               bio = *hbio;
-               *hbio = (*hbio)->bi_next;
-               bio_endio(bio);
-       }
        return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 }
 
@@ -992,11 +990,9 @@ pscsi_execute_cmd(struct se_cmd *cmd)
 {
        struct scatterlist *sgl = cmd->t_data_sg;
        u32 sgl_nents = cmd->t_data_nents;
-       enum dma_data_direction data_direction = cmd->data_direction;
        struct pscsi_dev_virt *pdv = PSCSI_DEV(cmd->se_dev);
        struct pscsi_plugin_task *pt;
        struct request *req;
-       struct bio *hbio;
        sense_reason_t ret;
 
        /*
@@ -1012,31 +1008,21 @@ pscsi_execute_cmd(struct se_cmd *cmd)
        memcpy(pt->pscsi_cdb, cmd->t_task_cdb,
                scsi_command_size(cmd->t_task_cdb));
 
-       if (!sgl) {
-               req = blk_get_request(pdv->pdv_sd->request_queue,
-                               (data_direction == DMA_TO_DEVICE),
-                               GFP_KERNEL);
-               if (IS_ERR(req)) {
-                       pr_err("PSCSI: blk_get_request() failed\n");
-                       ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
-                       goto fail;
-               }
+       req = blk_get_request(pdv->pdv_sd->request_queue,
+                       (cmd->data_direction == DMA_TO_DEVICE),
+                       GFP_KERNEL);
+       if (IS_ERR(req)) {
+               pr_err("PSCSI: blk_get_request() failed\n");
+               ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+               goto fail;
+       }
 
-               blk_rq_set_block_pc(req);
-       } else {
-               BUG_ON(!cmd->data_length);
+       blk_rq_set_block_pc(req);
 
-               ret = pscsi_map_sg(cmd, sgl, sgl_nents, data_direction, &hbio);
+       if (sgl) {
+               ret = pscsi_map_sg(cmd, sgl, sgl_nents, req);
                if (ret)
-                       goto fail;
-
-               req = blk_make_request(pdv->pdv_sd->request_queue, hbio,
-                                      GFP_KERNEL);
-               if (IS_ERR(req)) {
-                       pr_err("pSCSI: blk_make_request() failed\n");
-                       ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
-                       goto fail_free_bio;
-               }
+                       goto fail_put_request;
        }
 
        req->end_io = pscsi_req_done;
@@ -1057,13 +1043,8 @@ pscsi_execute_cmd(struct se_cmd *cmd)
 
        return 0;
 
-fail_free_bio:
-       while (hbio) {
-               struct bio *bio = hbio;
-               hbio = hbio->bi_next;
-               bio_endio(bio);
-       }
-       ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+fail_put_request:
+       blk_put_request(req);
 fail:
        kfree(pt);
        return ret;