[SCSI] mptfc: correct out of order event processing

This patch corrects a problem in mptfc which can result in targets
being removed after executing an "lsiutil 99" reset of the fibre
channel ports.

The last rescan event was being processed before the setup reset work
due to an inappropriate optimization in the event processing logic.
Every rescan event is now queued for execution and the setup reset
work now executes in the proper sequence.

Signed-off-by: Michael Reed <mdr@sgi.com>
Acked-by: Moore, Eric <Eric.Moore@lsil.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

2 files changed, 34 insertions, 54 deletions

diff --git a/drivers/message/fusion/mptbase.h b/drivers/message/fusion/mptbase.h
index d4cb144ab402..c537d71c18e4 100644
--- a/drivers/message/fusion/mptbase.h
+++ b/drivers/message/fusion/mptbase.h
@@ -640,7 +640,6 @@ typedef struct _MPT_ADAPTER
         struct work_struct       fc_setup_reset_work;
         struct list_head         fc_rports;
         spinlock_t               fc_rescan_work_lock;
-        int                      fc_rescan_work_count;
         struct work_struct       fc_rescan_work;
         char                     fc_rescan_work_q_name[KOBJ_NAME_LEN];
         struct workqueue_struct *fc_rescan_work_q;
diff --git a/drivers/message/fusion/mptfc.c b/drivers/message/fusion/mptfc.c
index 2144554a640d..85696f34c310 100644
--- a/drivers/message/fusion/mptfc.c
+++ b/drivers/message/fusion/mptfc.c
@@ -898,59 +898,45 @@ mptfc_rescan_devices(void *arg)
 {
         MPT_ADAPTER             *ioc = (MPT_ADAPTER *)arg;
         int                     ii;
-        int                     work_to_do;
         u64                     pn;
-        unsigned long           flags;
         struct mptfc_rport_info *ri;
 
-        do {
-                /* start by tagging all ports as missing */
-                list_for_each_entry(ri, &ioc->fc_rports, list) {
-                        if (ri->flags & MPT_RPORT_INFO_FLAGS_REGISTERED) {
-                                ri->flags |= MPT_RPORT_INFO_FLAGS_MISSING;
-                        }
+        /* start by tagging all ports as missing */
+        list_for_each_entry(ri, &ioc->fc_rports, list) {
+                if (ri->flags & MPT_RPORT_INFO_FLAGS_REGISTERED) {
+                        ri->flags |= MPT_RPORT_INFO_FLAGS_MISSING;
                 }
+        }
 
-                /*
-                 * now rescan devices known to adapter,
-                 * will reregister existing rports
-                 */
-                for (ii=0; ii < ioc->facts.NumberOfPorts; ii++) {
-                        (void) mptfc_GetFcPortPage0(ioc, ii);
-                        mptfc_init_host_attr(ioc,ii);   /* refresh */
-                        mptfc_GetFcDevPage0(ioc,ii,mptfc_register_dev);
-                }
+        /*
+         * now rescan devices known to adapter,
+         * will reregister existing rports
+         */
+        for (ii=0; ii < ioc->facts.NumberOfPorts; ii++) {
+                (void) mptfc_GetFcPortPage0(ioc, ii);
+                mptfc_init_host_attr(ioc, ii);  /* refresh */
+                mptfc_GetFcDevPage0(ioc, ii, mptfc_register_dev);
+        }
 
-                /* delete devices still missing */
-                list_for_each_entry(ri, &ioc->fc_rports, list) {
-                        /* if newly missing, delete it */
-                        if (ri->flags & MPT_RPORT_INFO_FLAGS_MISSING) {
+        /* delete devices still missing */
+        list_for_each_entry(ri, &ioc->fc_rports, list) {
+                /* if newly missing, delete it */
+                if (ri->flags & MPT_RPORT_INFO_FLAGS_MISSING) {
 
-                                ri->flags &= ~(MPT_RPORT_INFO_FLAGS_REGISTERED|
-                                               MPT_RPORT_INFO_FLAGS_MISSING);
-                                fc_remote_port_delete(ri->rport);       /* won't sleep */
-                                ri->rport = NULL;
+                        ri->flags &= ~(MPT_RPORT_INFO_FLAGS_REGISTERED|
+                                       MPT_RPORT_INFO_FLAGS_MISSING);
+                        fc_remote_port_delete(ri->rport);       /* won't sleep */
+                        ri->rport = NULL;
 
-                                pn = (u64)ri->pg0.WWPN.High << 32 |
-                                     (u64)ri->pg0.WWPN.Low;
-                                dfcprintk ((MYIOC_s_INFO_FMT
-                                        "mptfc_rescan.%d: %llx deleted\n",
-                                        ioc->name,
-                                        ioc->sh->host_no,
-                                        (unsigned long long)pn));
-                        }
+                        pn = (u64)ri->pg0.WWPN.High << 32 |
+                             (u64)ri->pg0.WWPN.Low;
+                        dfcprintk ((MYIOC_s_INFO_FMT
+                                "mptfc_rescan.%d: %llx deleted\n",
+                                ioc->name,
+                                ioc->sh->host_no,
+                                (unsigned long long)pn));
                 }
-
-                /*
-                 * allow multiple passes as target state
-                 * might have changed during scan
-                 */
-                spin_lock_irqsave(&ioc->fc_rescan_work_lock, flags);
-                if (ioc->fc_rescan_work_count > 2)      /* only need one more */
-                        ioc->fc_rescan_work_count = 2;
-                work_to_do = --ioc->fc_rescan_work_count;
-                spin_unlock_irqrestore(&ioc->fc_rescan_work_lock, flags);
-        } while (work_to_do);
+        }
 }
 
 static int
@@ -1162,7 +1148,6 @@ mptfc_probe(struct pci_dev *pdev, const struct pci_device_id *id)
          *      by doing it via the workqueue, some locking is eliminated
          */
 
-        ioc->fc_rescan_work_count = 1;
         queue_work(ioc->fc_rescan_work_q, &ioc->fc_rescan_work);
         flush_workqueue(ioc->fc_rescan_work_q);
 
@@ -1205,10 +1190,8 @@ mptfc_event_process(MPT_ADAPTER *ioc, EventNotificationReply_t *pEvReply)
         case MPI_EVENT_RESCAN:
                 spin_lock_irqsave(&ioc->fc_rescan_work_lock, flags);
                 if (ioc->fc_rescan_work_q) {
-                        if (ioc->fc_rescan_work_count++ == 0) {
-                                queue_work(ioc->fc_rescan_work_q,
-                                           &ioc->fc_rescan_work);
-                        }
+                        queue_work(ioc->fc_rescan_work_q,
+                                   &ioc->fc_rescan_work);
                 }
                 spin_unlock_irqrestore(&ioc->fc_rescan_work_lock, flags);
                 break;
@@ -1251,10 +1234,8 @@ mptfc_ioc_reset(MPT_ADAPTER *ioc, int reset_phase)
                 mptfc_SetFcPortPage1_defaults(ioc);
                 spin_lock_irqsave(&ioc->fc_rescan_work_lock, flags);
                 if (ioc->fc_rescan_work_q) {
-                        if (ioc->fc_rescan_work_count++ == 0) {
-                                queue_work(ioc->fc_rescan_work_q,
-                                           &ioc->fc_rescan_work);
-                        }
+                        queue_work(ioc->fc_rescan_work_q,
+                                   &ioc->fc_rescan_work);
                 }
                 spin_unlock_irqrestore(&ioc->fc_rescan_work_lock, flags);
         }