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bsg bidirectional and variable length commands

PATCH New Pete Wyckoff 1 participant 4 messages Aug 15, 2007

Subsystems (4)
SCSI Block layer iSCSI BSG (block layer generic sg v4 driver)
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Pete Wyckoff

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#0 lore raw

cover bsg bidirectional and variable length commands

There are three patches here to enable using BSG to send SCSI commands across iscsi TCP that are bidirectional and/or use variable length CDBs. They sit on top of 2.6.23-rc2 plus Mike's iscsi git plus the 12 core patches that Boaz has for bidirectional support.

They apply to stock 2.6.23-rc2 but I don't think it is worth anybody's time to take them yet. Instead, I think it makes sense for Boaz to hang onto these and submit them along as part of the bigger bidirectional support picture.

		-- Pete
author
#1 lore raw

PATCH 1/3 bsg bidi block pc

Set cmd_type on rq->next_rq to BLOCK_PC so that scsi_init_sgtable knows to look at req->data_len rather than nr_sectors.

Signed-off-by Pete Wyckoff <[email protected]>
---
 block/bsg.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
block/bsg.c +1 -0
index ba4353a..eb0aaf4 100644
@@ -278,6 +278,7 @@ bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr)
 			ret = -ENOMEM;
 			goto out;
 		}
+		next_rq->cmd_type = REQ_TYPE_BLOCK_PC;
 		rq->next_rq = next_rq;
 
 		dxferp = (void*)(unsigned long)hdr->din_xferp;
Signature · 1 line
1.5.2.4
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#2 lore raw

PATCH 2/3 iscsi tcp queue bidi

In reply to Pete Wyckoff

Mark queue_flags that bidirectional is acceptable for iscsi_tcp, as BSG will check to make sure this bit is set.

Signed-off-by Pete Wyckoff <[email protected]>
---
 drivers/scsi/iscsi_tcp.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)
drivers/scsi/iscsi_tcp.c +7 -0
index 35dd19f..8622930 100644
@@ -2205,6 +2205,12 @@ static void iscsi_tcp_session_destroy(struct iscsi_cls_session *cls_session)
 	iscsi_session_teardown(cls_session);
 }
 
+static int iscsi_tcp_slave_alloc(struct scsi_device *sdev)
+{
+	set_bit(QUEUE_FLAG_BIDI, &sdev->request_queue->queue_flags);
+	return 0;
+}
+
 static int iscsi_tcp_slave_configure(struct scsi_device *sdev)
 {
 	blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_ANY);

@@ -2224,6 +2230,7 @@ static struct scsi_host_template iscsi_sht = {
 	.eh_abort_handler       = iscsi_eh_abort,
 	.eh_host_reset_handler	= iscsi_eh_host_reset,
 	.use_clustering         = DISABLE_CLUSTERING,
+	.slave_alloc		= iscsi_tcp_slave_alloc,
 	.slave_configure        = iscsi_tcp_slave_configure,
 	.proc_name		= "iscsi_tcp",
 	.this_id		= -1,
Signature · 1 line
1.5.2.4
author
#3 lore raw

PATCH 3/3 varlen bsg submit

In reply to Pete Wyckoff

Accept variable length SCSI commands through BSG.

Signed-off-by Pete Wyckoff <[email protected]>
---
 block/bsg.c |   19 +++++++++++++++----
 1 files changed, 15 insertions(+), 4 deletions(-)
block/bsg.c +15 -4
index eb0aaf4..c72b4f9 100644
@@ -175,11 +175,22 @@ unlock:
 static int blk_fill_sgv4_hdr_rq(struct request_queue *q, struct request *rq,
 				struct sg_io_v4 *hdr, int has_write_perm)
 {
+	int len = hdr->request_len;
+
 	memset(rq->cmd, 0, BLK_MAX_CDB); /* ATAPI hates garbage after CDB */
 
 	if (copy_from_user(rq->cmd, (void *)(unsigned long)hdr->request,
-			   hdr->request_len))
+			   min(len, BLK_MAX_CDB)))
 		return -EFAULT;
+	if (len > BLK_MAX_CDB) {
+		rq->varlen_cdb_len = len;
+		rq->varlen_cdb = kmalloc(len, GFP_KERNEL);
+		if (rq->varlen_cdb == NULL)
+			return -ENOMEM;
+		if (copy_from_user(rq->varlen_cdb,
+		                   (void *)(unsigned long)hdr->request, len))
+			return -EFAULT;
+	}
 
 	if (hdr->subprotocol == BSG_SUB_PROTOCOL_SCSI_CMD) {
 		if (blk_verify_command(rq->cmd, has_write_perm))

@@ -190,7 +201,7 @@ static int blk_fill_sgv4_hdr_rq(struct request_queue *q, struct request *rq,
 	/*
 	 * fill in request structure
 	 */
-	rq->cmd_len = hdr->request_len;
+	rq->cmd_len = min(len, BLK_MAX_CDB);
 	rq->cmd_type = REQ_TYPE_BLOCK_PC;
 
 	rq->timeout = (hdr->timeout * HZ) / 1000;

@@ -212,8 +223,6 @@ bsg_validate_sgv4_hdr(struct request_queue *q, struct sg_io_v4 *hdr, int *rw)
 
 	if (hdr->guard != 'Q')
 		return -EINVAL;
-	if (hdr->request_len > BLK_MAX_CDB)
-		return -EINVAL;
 	if (hdr->dout_xfer_len > (q->max_sectors << 9) ||
 	    hdr->din_xfer_len > (q->max_sectors << 9))
 		return -EIO;

@@ -303,6 +312,7 @@ bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr)
 	}
 	return rq;
 out:
+	kfree(rq->varlen_cdb);
 	blk_put_request(rq);
 	if (next_rq) {
 		blk_rq_unmap_user(next_rq->bio);

@@ -443,6 +453,7 @@ static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr,
 	}
 
 	blk_rq_unmap_user(bio);
+	kfree(rq->varlen_cdb);
 	blk_put_request(rq);
 
 	return ret;
Signature · 1 line
1.5.2.4