[SCSI] qla2xxx: Ensure there's enough request-queue space for passthru IOCBs.

The driver should ensure there's a sufficient number of IOCBs
to satisfy the number of scatter-gather entries specified in the
command.  Add a 'count' to the control structure, srb_ctx, to use
in qla2x00_alloc_iocbs().

Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: Chad Dupuis <chad.dupuis@qlogic.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

drivers/scsi/qla2xxx/qla_bsg.c

@@ -31,6 +31,7 @@ qla2x00_get_ctx_bsg_sp(scsi_qla_host_t *vha, fc_port_t *fcport, size_t size)
 	memset(sp, 0, sizeof(*sp));
 	sp->fcport = fcport;
 	sp->ctx = ctx;
+	ctx->iocbs = 1;
 done:
 	return sp;
 }
@@ -389,6 +390,20 @@ done:
 	return rval;
 }
 
+inline uint16_t
+qla24xx_calc_ct_iocbs(uint16_t dsds)
+{
+	uint16_t iocbs;
+
+	iocbs = 1;
+	if (dsds > 2) {
+		iocbs += (dsds - 2) / 5;
+		if ((dsds - 2) % 5)
+			iocbs++;
+	}
+	return iocbs;
+}
+
 static int
 qla2x00_process_ct(struct fc_bsg_job *bsg_job)
 {
@@ -489,6 +504,7 @@ qla2x00_process_ct(struct fc_bsg_job *bsg_job)
 	ct = sp->ctx;
 	ct->type = SRB_CT_CMD;
 	ct->name = "bsg_ct";
+	ct->iocbs = qla24xx_calc_ct_iocbs(req_sg_cnt + rsp_sg_cnt);
 	ct->u.bsg_job = bsg_job;
 
 	ql_dbg(ql_dbg_user, vha, 0x7016,

drivers/scsi/qla2xxx/qla_def.h

@@ -271,6 +271,7 @@ struct srb_iocb {
 struct srb_ctx {
 	uint16_t type;
 	char *name;
+	int iocbs;
 	union {
 		struct srb_iocb *iocb_cmd;
 		struct fc_bsg_job *bsg_job;

drivers/scsi/qla2xxx/qla_init.c

@@ -111,6 +111,7 @@ qla2x00_get_ctx_sp(scsi_qla_host_t *vha, fc_port_t *fcport, size_t size,
 	memset(sp, 0, sizeof(*sp));
 	sp->fcport = fcport;
 	sp->ctx = ctx;
+	ctx->iocbs = 1;
 	ctx->u.iocb_cmd = iocb;
 	iocb->free = qla2x00_ctx_sp_free;
 

drivers/scsi/qla2xxx/qla_iocb.c

@@ -1818,6 +1818,7 @@ qla2x00_alloc_iocbs(scsi_qla_host_t *vha, srb_t *sp)
 	uint32_t index, handle;
 	request_t *pkt;
 	uint16_t cnt, req_cnt;
+	struct srb_ctx *ctx;
 
 	pkt = NULL;
 	req_cnt = 1;
@@ -1846,6 +1847,12 @@ qla2x00_alloc_iocbs(scsi_qla_host_t *vha, srb_t *sp)
 	req->outstanding_cmds[handle] = sp;
 	sp->handle = handle;
 
+	/* Adjust entry-counts as needed. */
+	if (sp->ctx) {
+		ctx = sp->ctx;
+		req_cnt = ctx->iocbs;
+	}
+
 skip_cmd_array:
 	/* Check for room on request queue. */
 	if (req->cnt < req_cnt) {
@@ -2622,8 +2629,8 @@ qla2x00_start_sp(srb_t *sp)
 		break;
 	case SRB_CT_CMD:
 		IS_FWI2_CAPABLE(ha) ?
-		qla24xx_ct_iocb(sp, pkt) :
-		qla2x00_ct_iocb(sp, pkt);
+		    qla24xx_ct_iocb(sp, pkt) :
+		    qla2x00_ct_iocb(sp, pkt);
 		break;
 	case SRB_ADISC_CMD:
 		IS_FWI2_CAPABLE(ha) ?