From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
This patch updates the TCM/pSCSI plugin to support BIDI-COMMAND passthrough to the
Linux/SCSI MidLayer using struct se_task->task_sg_bidi[] from commit 2f2e67d85860,
and the setup of the extra struct request for the BIDI SCSI READ payload.
This patchturns the original pscsi_map_task_SG() into a wrapper call for the
new __pscsi_map_task_SG() which now accepts struct scatterlist *task_sg and u32 task_sg_num
for struct se_task -> struct bio allocation, map and blk_make_request() calls.
It also updates pscsi_blk_init_request() which now gets called twice for BIDI-COMMAND
case. This includes the pscsi_blk_init_request() change to perform the assignment of
'req->cmd = &pt->pscsi_cdb[0]' and drop the original CDB memcpy() of pt->pscsi_cdb[]
into struct request->cmd[] -> struct request->__cmd[MAX_BLK_CDB].
Tested with scsi_debug w/ XDWRITE_READ32 and TCM_Loop w/ TCM/pSCSI backstores
using 'sgv4_xdwriteread -e'.
Signed-off-by: Nicholas A. Bellinger <nab@xxxxxxxxxxxxxxx>
---
drivers/target/target_core_pscsi.c | 111 +++++++++++++++++++++++++++--------
drivers/target/target_core_pscsi.h | 1 +
2 files changed, 86 insertions(+), 26 deletions(-)
diff --git a/drivers/target/target_core_pscsi.c b/drivers/target/target_core_pscsi.c
index beca807..60f825d 100644
--- a/drivers/target/target_core_pscsi.c
+++ b/drivers/target/target_core_pscsi.c
@@ -727,29 +727,37 @@ static void *pscsi_allocate_request(
static inline void pscsi_blk_init_request(
struct se_task *task,
- struct pscsi_plugin_task *pt)
+ struct pscsi_plugin_task *pt,
+ struct request *req,
+ int bidi_read)
{
/*
* Defined as "scsi command" in include/linux/blkdev.h.
*/
- pt->pscsi_req->cmd_type = REQ_TYPE_BLOCK_PC;
+ req->cmd_type = REQ_TYPE_BLOCK_PC;
+ /*
+ * For the extra BIDI-COMMAND READ struct request we do not
+ * need to setup the remaining structure members
+ */
+ if (bidi_read)
+ return;
/*
* Setup the done function pointer for struct request,
* also set the end_io_data pointer.to struct se_task.
*/
- pt->pscsi_req->end_io = pscsi_req_done;
- pt->pscsi_req->end_io_data = (void *)task;
+ req->end_io = pscsi_req_done;
+ req->end_io_data = (void *)task;
/*
* Load the referenced struct se_task's SCSI CDB into
* include/linux/blkdev.h:struct request->cmd
*/
- pt->pscsi_req->cmd_len = scsi_command_size(pt->pscsi_cdb);
- memcpy(pt->pscsi_req->cmd, pt->pscsi_cdb, pt->pscsi_req->cmd_len);
+ req->cmd_len = scsi_command_size(pt->pscsi_cdb);
+ req->cmd = &pt->pscsi_cdb[0];
/*
* Setup pointer for outgoing sense data.
*/
- pt->pscsi_req->sense = (void *)&pt->pscsi_sense[0];
- pt->pscsi_req->sense_len = 0;
+ req->sense = (void *)&pt->pscsi_sense[0];
+ req->sense_len = 0;
}
/*
@@ -771,7 +779,7 @@ static int pscsi_blk_get_request(struct se_task *task)
* Setup the newly allocated struct request for REQ_TYPE_BLOCK_PC,
* and setup rq callback, CDB and sense.
*/
- pscsi_blk_init_request(task, pt);
+ pscsi_blk_init_request(task, pt, pt->pscsi_req, 0);
return 0;
}
@@ -1051,11 +1059,11 @@ static inline struct bio *pscsi_get_bio(struct pscsi_dev_virt *pdv, int sg_num)
#define DEBUG_PSCSI(x...)
#endif
-/* pscsi_map_task_SG():
- *
- *
- */
-static int pscsi_map_task_SG(struct se_task *task)
+static int __pscsi_map_task_SG(
+ struct se_task *task,
+ struct scatterlist *task_sg,
+ u32 task_sg_num,
+ int bidi_read)
{
struct pscsi_plugin_task *pt = (struct pscsi_plugin_task *) task->transport_req;
struct pscsi_dev_virt *pdv = (struct pscsi_dev_virt *) task->se_dev->dev_ptr;
@@ -1063,7 +1071,7 @@ static int pscsi_map_task_SG(struct se_task *task)
struct page *page;
struct scatterlist *sg;
u32 data_len = task->task_size, i, len, bytes, off;
- int nr_pages = (task->task_size + task->task_sg[0].offset +
+ int nr_pages = (task->task_size + task_sg[0].offset +
PAGE_SIZE - 1) >> PAGE_SHIFT;
int nr_vecs = 0, ret = 0;
int rw = (TASK_CMD(task)->data_direction == DMA_TO_DEVICE);
@@ -1083,7 +1091,7 @@ static int pscsi_map_task_SG(struct se_task *task)
*/
DEBUG_PSCSI("PSCSI: nr_pages: %d\n", nr_pages);
- for_each_sg(task->task_sg, sg, task->task_sg_num, i) {
+ for_each_sg(task_sg, sg, task_sg_num, i) {
page = sg_page(sg);
off = sg->offset;
len = sg->length;
@@ -1155,20 +1163,44 @@ static int pscsi_map_task_SG(struct se_task *task)
}
}
/*
- * Starting with v2.6.31, call blk_make_request() passing in *hbio to
- * allocate the pSCSI task a struct request.
+ * Setup the primary pt->pscsi_req used for non BIDI and BIDI-COMMAND
+ * primary SCSI WRITE poayload mapped for struct se_task->task_sg[]
*/
- pt->pscsi_req = blk_make_request(pdv->pdv_sd->request_queue,
- hbio, GFP_KERNEL);
- if (!(pt->pscsi_req)) {
- printk(KERN_ERR "pSCSI: blk_make_request() failed\n");
- goto fail;
+ if (!(bidi_read)) {
+ /*
+ * Starting with v2.6.31, call blk_make_request() passing in *hbio to
+ * allocate the pSCSI task a struct request.
+ */
+ pt->pscsi_req = blk_make_request(pdv->pdv_sd->request_queue,
+ hbio, GFP_KERNEL);
+ if (!(pt->pscsi_req)) {
+ printk(KERN_ERR "pSCSI: blk_make_request() failed\n");
+ goto fail;
+ }
+ /*
+ * Setup the newly allocated struct request for REQ_TYPE_BLOCK_PC,
+ * and setup rq callback, CDB and sense.
+ */
+ pscsi_blk_init_request(task, pt, pt->pscsi_req, 0);
+
+ return task->task_sg_num;
}
/*
- * Setup the newly allocated struct request for REQ_TYPE_BLOCK_PC,
- * and setup rq callback, CDB and sense.
+ * Setup the secondary pt->pscsi_req_bidi used for the extra BIDI-COMMAND
+ * SCSI READ paylaod mapped for struct se_task->task_sg_bidi[]
*/
- pscsi_blk_init_request(task, pt);
+ pt->pscsi_req_bidi = blk_make_request(pdv->pdv_sd->request_queue,
+ hbio, GFP_KERNEL);
+ if (!(pt->pscsi_req_bidi)) {
+ printk(KERN_ERR "pSCSI: blk_make_request() failed for BIDI\n");
+ goto fail;
+ }
+ pscsi_blk_init_request(task, pt, pt->pscsi_req_bidi, 1);
+ /*
+ * Setup the magic BIDI-COMMAND ->next_req pointer to the original
+ * pt->pscsi_req.
+ */
+ pt->pscsi_req->next_rq = pt->pscsi_req_bidi;
return task->task_sg_num;
fail:
@@ -1181,6 +1213,27 @@ fail:
return ret;
}
+static int pscsi_map_task_SG(struct se_task *task)
+{
+ int ret;
+ /*
+ * Setup the main struct request for the task->task_sg[] payload
+ */
+
+ ret = __pscsi_map_task_SG(task, task->task_sg, task->task_sg_num, 0);
+ if (ret < 0)
+ return ret;
+
+ if (!(task->task_sg_bidi))
+ return ret;
+ /*
+ * If present, set up the extra BIDI-COMMAND SCSI READ
+ * struct request and payload.
+ */
+ return __pscsi_map_task_SG(task, task->task_sg_bidi,
+ task->task_sg_num, 1);
+}
+
/* pscsi_map_task_non_SG():
*
*
@@ -1438,6 +1491,12 @@ static void pscsi_req_done(struct request *req, int uptodate)
pt->pscsi_resid = req->resid_len;
pscsi_process_SAM_status(task, pt);
+
+ if (req->next_rq != NULL) {
+ __blk_put_request(req->q, req->next_rq);
+ pt->pscsi_req_bidi = NULL;
+ }
+
__blk_put_request(req->q, req);
pt->pscsi_req = NULL;
}
diff --git a/drivers/target/target_core_pscsi.h b/drivers/target/target_core_pscsi.h
index 086e6f1..d3c8972 100644
--- a/drivers/target/target_core_pscsi.h
+++ b/drivers/target/target_core_pscsi.h
@@ -34,6 +34,7 @@ struct pscsi_plugin_task {
int pscsi_result;
u32 pscsi_resid;
struct request *pscsi_req;
+ struct request *pscsi_req_bidi;
} ____cacheline_aligned;
#define PDF_HAS_CHANNEL_ID 0x01
--
1.5.6.5
--
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