[SCSI] lpfc 8.3.0 : Fix system crash due to uninitialized node access

In the IOCB completion handler, always check if the node is valid
before accessing the node object.  Added lpfc_initialize_node() to
initialize nodes.

Signed-off-by: James Smart <James.Smart@emulex.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

2 files changed, 56 insertions, 40 deletions

diff --git a/drivers/scsi/lpfc/lpfc_hbadisc.c b/drivers/scsi/lpfc/lpfc_hbadisc.c
index 58ed6859c92..ba120530cf8 100644
--- a/drivers/scsi/lpfc/lpfc_hbadisc.c
+++ b/drivers/scsi/lpfc/lpfc_hbadisc.c
@@ -1857,6 +1857,32 @@ lpfc_disable_node(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp)
         lpfc_nlp_state_cleanup(vport, ndlp, ndlp->nlp_state,
                                 NLP_STE_UNUSED_NODE);
 }
+/**
+ * lpfc_initialize_node: Initialize all fields of node object.
+ * @vport: Pointer to Virtual Port object.
+ * @ndlp: Pointer to FC node object.
+ * @did: FC_ID of the node.
+ *      This function is always called when node object need to
+ * be initialized. It initializes all the fields of the node
+ * object.
+ **/
+static inline void
+lpfc_initialize_node(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp,
+        uint32_t did)
+{
+        INIT_LIST_HEAD(&ndlp->els_retry_evt.evt_listp);
+        INIT_LIST_HEAD(&ndlp->dev_loss_evt.evt_listp);
+        init_timer(&ndlp->nlp_delayfunc);
+        ndlp->nlp_delayfunc.function = lpfc_els_retry_delay;
+        ndlp->nlp_delayfunc.data = (unsigned long)ndlp;
+        ndlp->nlp_DID = did;
+        ndlp->vport = vport;
+        ndlp->nlp_sid = NLP_NO_SID;
+        kref_init(&ndlp->kref);
+        NLP_INT_NODE_ACT(ndlp);
+        atomic_set(&ndlp->cmd_pending, 0);
+        ndlp->cmd_qdepth = LPFC_MAX_TGT_QDEPTH;
+}
 
 struct lpfc_nodelist *
 lpfc_enable_node(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp,
@@ -1897,17 +1923,7 @@ lpfc_enable_node(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp,
         /* re-initialize ndlp except of ndlp linked list pointer */
         memset((((char *)ndlp) + sizeof (struct list_head)), 0,
                 sizeof (struct lpfc_nodelist) - sizeof (struct list_head));
-        INIT_LIST_HEAD(&ndlp->els_retry_evt.evt_listp);
-        INIT_LIST_HEAD(&ndlp->dev_loss_evt.evt_listp);
-        init_timer(&ndlp->nlp_delayfunc);
-        ndlp->nlp_delayfunc.function = lpfc_els_retry_delay;
-        ndlp->nlp_delayfunc.data = (unsigned long)ndlp;
-        ndlp->nlp_DID = did;
-        ndlp->vport = vport;
-        ndlp->nlp_sid = NLP_NO_SID;
-        /* ndlp management re-initialize */
-        kref_init(&ndlp->kref);
-        NLP_INT_NODE_ACT(ndlp);
+        lpfc_initialize_node(vport, ndlp, did);
 
         spin_unlock_irqrestore(&phba->ndlp_lock, flags);
 
@@ -3121,19 +3137,9 @@ lpfc_nlp_init(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp,
               uint32_t did)
 {
         memset(ndlp, 0, sizeof (struct lpfc_nodelist));
-        INIT_LIST_HEAD(&ndlp->els_retry_evt.evt_listp);
-        INIT_LIST_HEAD(&ndlp->dev_loss_evt.evt_listp);
-        init_timer(&ndlp->nlp_delayfunc);
-        ndlp->nlp_delayfunc.function = lpfc_els_retry_delay;
-        ndlp->nlp_delayfunc.data = (unsigned long)ndlp;
-        ndlp->nlp_DID = did;
-        ndlp->vport = vport;
-        ndlp->nlp_sid = NLP_NO_SID;
+
+        lpfc_initialize_node(vport, ndlp, did);
         INIT_LIST_HEAD(&ndlp->nlp_listp);
-        kref_init(&ndlp->kref);
-        NLP_INT_NODE_ACT(ndlp);
-        atomic_set(&ndlp->cmd_pending, 0);
-        ndlp->cmd_qdepth = LPFC_MAX_TGT_QDEPTH;
 
         lpfc_debugfs_disc_trc(vport, LPFC_DISC_TRC_NODE,
                 "node init:       did:x%x",
diff --git a/drivers/scsi/lpfc/lpfc_scsi.c b/drivers/scsi/lpfc/lpfc_scsi.c
index 6293b6fc65a..cf6b2d40a92 100644
--- a/drivers/scsi/lpfc/lpfc_scsi.c
+++ b/drivers/scsi/lpfc/lpfc_scsi.c
@@ -945,7 +945,8 @@ lpfc_scsi_cmd_iocb_cmpl(struct lpfc_hba *phba, struct lpfc_iocbq *pIocbIn,
 
         lpfc_cmd->result = pIocbOut->iocb.un.ulpWord[4];
         lpfc_cmd->status = pIocbOut->iocb.ulpStatus;
-        atomic_dec(&pnode->cmd_pending);
+        if (pnode && NLP_CHK_NODE_ACT(pnode))
+                atomic_dec(&pnode->cmd_pending);
 
         if (lpfc_cmd->status) {
                 if (lpfc_cmd->status == IOSTAT_LOCAL_REJECT &&
@@ -1035,23 +1036,31 @@ lpfc_scsi_cmd_iocb_cmpl(struct lpfc_hba *phba, struct lpfc_iocbq *pIocbIn,
            time_after(jiffies, lpfc_cmd->start_time +
                 msecs_to_jiffies(vport->cfg_max_scsicmpl_time))) {
                 spin_lock_irqsave(sdev->host->host_lock, flags);
-                if ((pnode->cmd_qdepth > atomic_read(&pnode->cmd_pending) &&
-                    (atomic_read(&pnode->cmd_pending) > LPFC_MIN_TGT_QDEPTH) &&
-                    ((cmd->cmnd[0] == READ_10) || (cmd->cmnd[0] == WRITE_10))))
-                        pnode->cmd_qdepth = atomic_read(&pnode->cmd_pending);
-
-                pnode->last_change_time = jiffies;
+                if (pnode && NLP_CHK_NODE_ACT(pnode)) {
+                        if (pnode->cmd_qdepth >
+                                atomic_read(&pnode->cmd_pending) &&
+                                (atomic_read(&pnode->cmd_pending) >
+                                LPFC_MIN_TGT_QDEPTH) &&
+                                ((cmd->cmnd[0] == READ_10) ||
+                                (cmd->cmnd[0] == WRITE_10)))
+                                pnode->cmd_qdepth =
+                                        atomic_read(&pnode->cmd_pending);
+
+                        pnode->last_change_time = jiffies;
+                }
                 spin_unlock_irqrestore(sdev->host->host_lock, flags);
-        } else if ((pnode->cmd_qdepth < LPFC_MAX_TGT_QDEPTH) &&
+        } else if (pnode && NLP_CHK_NODE_ACT(pnode)) {
+                if ((pnode->cmd_qdepth < LPFC_MAX_TGT_QDEPTH) &&
                    time_after(jiffies, pnode->last_change_time +
-                        msecs_to_jiffies(LPFC_TGTQ_INTERVAL))) {
-                spin_lock_irqsave(sdev->host->host_lock, flags);
-                pnode->cmd_qdepth += pnode->cmd_qdepth *
-                        LPFC_TGTQ_RAMPUP_PCENT / 100;
-                if (pnode->cmd_qdepth > LPFC_MAX_TGT_QDEPTH)
-                        pnode->cmd_qdepth = LPFC_MAX_TGT_QDEPTH;
-                pnode->last_change_time = jiffies;
-                spin_unlock_irqrestore(sdev->host->host_lock, flags);
+                              msecs_to_jiffies(LPFC_TGTQ_INTERVAL))) {
+                        spin_lock_irqsave(sdev->host->host_lock, flags);
+                        pnode->cmd_qdepth += pnode->cmd_qdepth *
+                                LPFC_TGTQ_RAMPUP_PCENT / 100;
+                        if (pnode->cmd_qdepth > LPFC_MAX_TGT_QDEPTH)
+                                pnode->cmd_qdepth = LPFC_MAX_TGT_QDEPTH;
+                        pnode->last_change_time = jiffies;
+                        spin_unlock_irqrestore(sdev->host->host_lock, flags);
+                }
         }
 
         lpfc_scsi_unprep_dma_buf(phba, lpfc_cmd);
@@ -1536,7 +1545,8 @@ lpfc_queuecommand(struct scsi_cmnd *cmnd, void (*done) (struct scsi_cmnd *))
                 cmnd->result = ScsiResult(DID_TRANSPORT_DISRUPTED, 0);
                 goto out_fail_command;
         }
-        if (atomic_read(&ndlp->cmd_pending) >= ndlp->cmd_qdepth)
+        if (vport->cfg_max_scsicmpl_time &&
+                (atomic_read(&ndlp->cmd_pending) >= ndlp->cmd_qdepth))
                 goto out_host_busy;
 
         lpfc_cmd = lpfc_get_scsi_buf(phba);