[SCSI] qla2xxx: Check for empty slot in request queue before posting Command type 6 request.

For ISP82xx, the check for empty slot in request queue before posting command type 6
request was missing. This could lead to request queue entry corruptions causing
IO timeouts.

Signed-off-by: Giridhar Malavali <giridhar.malavali@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

1 files changed, 13 insertions, 0 deletions

diff --git a/drivers/scsi/qla2xxx/qla_nx.c b/drivers/scsi/qla2xxx/qla_nx.c
index ad290dc9ba35..0a71cc71eab2 100644
--- a/drivers/scsi/qla2xxx/qla_nx.c
+++ b/drivers/scsi/qla2xxx/qla_nx.c
@@ -2672,6 +2672,19 @@ qla82xx_start_scsi(srb_t *sp)
 sufficient_dsds:
                 req_cnt = 1;
 
+                if (req->cnt < (req_cnt + 2)) {
+                        cnt = (uint16_t)RD_REG_DWORD_RELAXED(
+                                &reg->req_q_out[0]);
+                        if (req->ring_index < cnt)
+                                req->cnt = cnt - req->ring_index;
+                        else
+                                req->cnt = req->length -
+                                        (req->ring_index - cnt);
+                }
+
+                if (req->cnt < (req_cnt + 2))
+                        goto queuing_error;
+
                 ctx = sp->ctx = mempool_alloc(ha->ctx_mempool, GFP_ATOMIC);
                 if (!sp->ctx) {
                         DEBUG(printk(KERN_INFO