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@xxxxxx>
---
drivers/target/target_core_pscsi.c | 87 +++++++++++++++-----------------------
1 file changed, 34 insertions(+), 53 deletions(-)
diff --git a/drivers/target/target_core_pscsi.c b/drivers/target/target_core_pscsi.c
index 81564c8..9125d93 100644
--- 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;
--
2.1.4
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