Hello,
This patch updates the TCM/pSCSI subsystem plugin for v2.6.31-rc to use the new helper function
block/blk-core.c:blk_make_request() for doing struct page -> struct bio -> struct request
mapped I/O to an underlying struct scsi_device.
This patch updates pscsi_map_task_SG() to directly call blk_make_request() for a
bio_kmalloc() allocated chain of struct bios that have had bio_add_pc_page() called on
them from the generic target engine physical (page) memory. This patch also updates
pscsi_CDB_read_SG() and pscsi_CDB_write_SG() (which both call pscsi_map_task_SG()) and
removes the now un-necessary calls to pscsi_blk_get_request().
This patch also adds a function named pscsi_blk_init_request() that is used by both
pscsi_map_task_SG() that uses blk_make_request() for SCF_SCSI_DATA_SG_IO_CDB type IO,
and by pscsi_blk_get_request() which uses blk_get_request() for all *NON* SCF_SCSI_DATA_SG_IO_CDB type IO.
pscsi_blk_init_request() will set the newly allocated struct request for REQ_TYPE_BLOCK_PC,
and setup the rq callback, CDB copy and sense data pointer between pscsi_plugin_task_t and
struct request.
Also, pscsi_get_max_sectors() was updated to use struct request_queue->limits.max_sectors,
and pscsi_req_done() was also updated to use the new struct request->resid_len.
So far, this patch is passing initial tests with badblocks with LIO-Target on v2.6.31-rc5
x86 KVM with virtual mptfusion SCSI of TYPE_DISK, and with v2.6.31-rc6 on ppc64 using
physical TYPE_ROM export.
Signed-off-by: Nicholas A. Bellinger <nab@xxxxxxxxxxxxxxx>
---
drivers/target/target_core_pscsi.c | 129 +++++++++++++++++++++++-------------
1 files changed, 84 insertions(+), 45 deletions(-)
diff --git a/drivers/target/target_core_pscsi.c b/drivers/target/target_core_pscsi.c
index e81c9fa..f261926 100644
--- a/drivers/target/target_core_pscsi.c
+++ b/drivers/target/target_core_pscsi.c
@@ -815,18 +815,8 @@ void *pscsi_allocate_request(
return pt;
}
-static int pscsi_blk_get_request(se_task_t *task)
+static inline void pscsi_blk_init_request(se_task_t *task, pscsi_plugin_task_t *pt)
{
- pscsi_plugin_task_t *pt = (pscsi_plugin_task_t *) task->transport_req;
- pscsi_dev_virt_t *pdv = (pscsi_dev_virt_t *) task->se_dev->dev_ptr;
-
- pt->pscsi_req = blk_get_request(pdv->pdv_sd->request_queue,
- (pt->pscsi_direction == DMA_TO_DEVICE), GFP_KERNEL);
- if (!(pt->pscsi_req) || IS_ERR(pt->pscsi_req)) {
- printk(KERN_ERR "PSCSI: blk_get_request() failed: %ld\n",
- IS_ERR(pt->pscsi_req));
- return PYX_TRANSPORT_LOGICAL_UNIT_COMMUNICATION_FAILURE;
- }
/*
* Defined as "scsi command" in include/linux/blkdev.h.
*/
@@ -848,7 +838,28 @@ static int pscsi_blk_get_request(se_task_t *task)
*/
pt->pscsi_req->sense = (void *)&pt->pscsi_sense[0];
pt->pscsi_req->sense_len = 0;
+}
+
+/*
+ * Used for pSCSI data payloads for all *NON* SCF_SCSI_DATA_SG_IO_CDB
+*/
+static int pscsi_blk_get_request(se_task_t *task)
+{
+ pscsi_plugin_task_t *pt = (pscsi_plugin_task_t *) task->transport_req;
+ pscsi_dev_virt_t *pdv = (pscsi_dev_virt_t *) task->se_dev->dev_ptr;
+ pt->pscsi_req = blk_get_request(pdv->pdv_sd->request_queue,
+ (pt->pscsi_direction == DMA_TO_DEVICE), GFP_KERNEL);
+ if (!(pt->pscsi_req) || IS_ERR(pt->pscsi_req)) {
+ printk(KERN_ERR "PSCSI: blk_get_request() failed: %ld\n",
+ IS_ERR(pt->pscsi_req));
+ return PYX_TRANSPORT_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+ }
+ /*
+ * Setup the newly allocated struct request for REQ_TYPE_BLOCK_PC,
+ * and setup rq callback, CDB and sense.
+ */
+ pscsi_blk_init_request(task, pt);
return 0;
}
@@ -1240,10 +1251,13 @@ static void pscsi_bi_endio(struct bio *bio, int error)
static inline struct bio *pscsi_get_bio(pscsi_dev_virt_t *pdv, int sg_num)
{
struct bio *bio;
-
- bio = bio_alloc(GFP_KERNEL, sg_num);
+ /*
+ * Use bio_malloc() following the comment in for bio -> struct request
+ * in block/blk-core.c:blk_make_request()
+ */
+ bio = bio_kmalloc(GFP_KERNEL, sg_num);
if (!(bio)) {
- printk(KERN_ERR "PSCSI: bio_alloc() failed\n");
+ printk(KERN_ERR "PSCSI: bio_kmalloc() failed\n");
return NULL;
}
bio->bi_end_io = pscsi_bi_endio;
@@ -1267,12 +1281,12 @@ int pscsi_map_task_SG(se_task_t *task)
pscsi_dev_virt_t *pdv = (pscsi_dev_virt_t *) task->se_dev->dev_ptr;
struct bio *bio = NULL, *hbio = NULL, *tbio = NULL;
struct page *page;
- struct request *rq = pt->pscsi_req;
struct scatterlist *sg;
u32 data_len = task->task_size, i, len, bytes, off;
int nr_pages = (task->task_size + task->task_sg[0].offset +
PAGE_SIZE - 1) >> PAGE_SHIFT;
int nr_vecs = 0, ret = 0;
+ int rw = (TASK_CMD(task)->data_direction == SE_DIRECTION_WRITE);
if (!task->task_size)
return 0;
@@ -1304,15 +1318,29 @@ int pscsi_map_task_SG(se_task_t *task)
if (!(bio)) {
nr_vecs = min_t(int, BIO_MAX_PAGES, nr_pages);
nr_pages -= nr_vecs;
-
+ /*
+ * Calls bio_kmalloc() and sets bio->bi_end_io()
+ */
bio = pscsi_get_bio(pdv, nr_vecs);
if (!(bio))
goto fail;
+ /*
+ * FIXME: Use bio_set_dir() when avaliable
+ */
+ if (rw)
+ bio->bi_rw |= (1 << BIO_RW);
DEBUG_PSCSI("PSCSI: Allocated bio: %p,"
- " nr_vecs: %d\n", bio, nr_vecs);
- if (!tbio)
- tbio = bio;
+ " 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
+ * se_task_t
+ */
+ if (!hbio)
+ hbio = tbio = bio;
else
tbio = tbio->bi_next = bio;
}
@@ -1329,18 +1357,16 @@ int pscsi_map_task_SG(se_task_t *task)
DEBUG_PSCSI("PSCSI: bio->bi_vcnt: %d nr_vecs: %d\n",
bio->bi_vcnt, nr_vecs);
- if (bio->bi_vcnt >= nr_vecs) {
- bio->bi_flags &= ~(1 << BIO_SEG_VALID);
- if (rq_data_dir(rq) == WRITE)
- bio->bi_rw |= (1 << BIO_RW);
- blk_queue_bounce(rq->q, &bio);
-
- DEBUG_PSCSI("PSCSI: Calling blk_rq_append_bio()"
- ": i: %d bio: %p\n", i, bio);
- ret = blk_rq_append_bio(rq->q, rq, bio);
- if (ret < 0)
- goto fail;
-
+ if (bio->bi_vcnt > nr_vecs) {
+ DEBUG_PSCSI("PSCSI: Reached bio->bi_vcnt max:"
+ " %d i: %d bio: %p, allocating another"
+ " bio\n", bio->bi_vcnt, i, bio);
+ /*
+ * 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.
+ */
bio = NULL;
}
@@ -1350,9 +1376,21 @@ int pscsi_map_task_SG(se_task_t *task)
off = 0;
}
}
-
- rq->buffer = rq->data = NULL;
- rq->data_len = task->task_size;
+ /*
+ * 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);
return task->task_sg_num;
fail:
@@ -1438,10 +1476,10 @@ int pscsi_CDB_read_SG(se_task_t *task, u32 size)
pscsi_plugin_task_t *pt = (pscsi_plugin_task_t *) task->transport_req;
pt->pscsi_direction = DMA_FROM_DEVICE;
-
- if (pscsi_blk_get_request(task) < 0)
- return PYX_TRANSPORT_LOGICAL_UNIT_COMMUNICATION_FAILURE;
-
+ /*
+ * pscsi_map_task_SG() calls block/blk-core.c:blk_make_request()
+ * for >= v2.6.31 pSCSI
+ */
if (pscsi_map_task_SG(task) < 0)
return PYX_TRANSPORT_LOGICAL_UNIT_COMMUNICATION_FAILURE;
@@ -1473,10 +1511,10 @@ int pscsi_CDB_write_SG(se_task_t *task, u32 size)
pscsi_plugin_task_t *pt = (pscsi_plugin_task_t *) task->transport_req;
pt->pscsi_direction = DMA_TO_DEVICE;
-
- if (pscsi_blk_get_request(task) < 0)
- return PYX_TRANSPORT_LOGICAL_UNIT_COMMUNICATION_FAILURE;
-
+ /*
+ * pscsi_map_task_SG() calls block/blk-core.c:blk_make_request()
+ * for >= v2.6.31 pSCSI
+ */
if (pscsi_map_task_SG(task) < 0)
return PYX_TRANSPORT_LOGICAL_UNIT_COMMUNICATION_FAILURE;
@@ -1576,8 +1614,9 @@ u32 pscsi_get_max_sectors(se_device_t *dev)
{
pscsi_dev_virt_t *pdv = (pscsi_dev_virt_t *) dev->dev_ptr;
struct scsi_device *sd = (struct scsi_device *) pdv->pdv_sd;
- return (sd->host->max_sectors > sd->request_queue->max_sectors) ?
- sd->request_queue->max_sectors : sd->host->max_sectors;
+
+ return (sd->host->max_sectors > sd->request_queue->limits.max_sectors) ?
+ sd->request_queue->limits.max_sectors : sd->host->max_sectors;
}
/* pscsi_get_queue_depth():
@@ -1638,7 +1677,7 @@ void pscsi_req_done(struct request *req, int uptodate)
pscsi_plugin_task_t *pt = (pscsi_plugin_task_t *)task->transport_req;
pt->pscsi_result = req->errors;
- pt->pscsi_resid = req->data_len;
+ pt->pscsi_resid = req->resid_len;
pscsi_process_SAM_status(task, pt);
__blk_put_request(req->q, req);
--
1.5.4.1
--
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
