[SCSI] libfcoe: convert FIP to lock with mutex instead of spin lock

It turns out most of the FIP work is now done from worker threads
or process context now, so there's no need to use a spin lock.

Change to use mutex instead of spin lock and delayed_work instead
of a timer.

This will make it nicer for the VN_port to VN_port feature that
will interact more with the libfc layers requiring that
spinlocks not be held.

Signed-off-by: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

1 files changed, 55 insertions, 61 deletions

diff --git a/drivers/scsi/fcoe/libfcoe.c b/drivers/scsi/fcoe/libfcoe.c
index f009191063f1..e510888e78ca 100644
--- a/drivers/scsi/fcoe/libfcoe.c
+++ b/drivers/scsi/fcoe/libfcoe.c
@@ -113,7 +113,7 @@ void fcoe_ctlr_init(struct fcoe_ctlr *fip)
 	fip->state = FIP_ST_LINK_WAIT;
 	fip->mode = FIP_ST_AUTO;
 	INIT_LIST_HEAD(&fip->fcfs);
-	spin_lock_init(&fip->lock);
+	mutex_init(&fip->ctlr_mutex);
 	fip->flogi_oxid = FC_XID_UNKNOWN;
 	setup_timer(&fip->timer, fcoe_ctlr_timeout, (unsigned long)fip);
 	INIT_WORK(&fip->timer_work, fcoe_ctlr_timer_work);
@@ -159,10 +159,10 @@ void fcoe_ctlr_destroy(struct fcoe_ctlr *fip)
 	cancel_work_sync(&fip->recv_work);
 	skb_queue_purge(&fip->fip_recv_list);
 
-	spin_lock_bh(&fip->lock);
+	mutex_lock(&fip->ctlr_mutex);
 	fip->state = FIP_ST_DISABLED;
 	fcoe_ctlr_reset_fcfs(fip);
-	spin_unlock_bh(&fip->lock);
+	mutex_unlock(&fip->ctlr_mutex);
 	del_timer_sync(&fip->timer);
 	cancel_work_sync(&fip->timer_work);
 }
@@ -255,19 +255,19 @@ static void fcoe_ctlr_solicit(struct fcoe_ctlr *fip, struct fcoe_fcf *fcf)
  */
 void fcoe_ctlr_link_up(struct fcoe_ctlr *fip)
 {
-	spin_lock_bh(&fip->lock);
+	mutex_lock(&fip->ctlr_mutex);
 	if (fip->state == FIP_ST_NON_FIP || fip->state == FIP_ST_AUTO) {
-		spin_unlock_bh(&fip->lock);
+		mutex_unlock(&fip->ctlr_mutex);
 		fc_linkup(fip->lp);
 	} else if (fip->state == FIP_ST_LINK_WAIT) {
 		fip->state = fip->mode;
-		spin_unlock_bh(&fip->lock);
+		mutex_unlock(&fip->ctlr_mutex);
 		if (fip->state == FIP_ST_AUTO)
 			LIBFCOE_FIP_DBG(fip, "%s", "setting AUTO mode.\n");
 		fc_linkup(fip->lp);
 		fcoe_ctlr_solicit(fip, NULL);
 	} else
-		spin_unlock_bh(&fip->lock);
+		mutex_unlock(&fip->ctlr_mutex);
 }
 EXPORT_SYMBOL(fcoe_ctlr_link_up);
 
@@ -300,11 +300,11 @@ int fcoe_ctlr_link_down(struct fcoe_ctlr *fip)
 	int link_dropped;
 
 	LIBFCOE_FIP_DBG(fip, "link down.\n");
-	spin_lock_bh(&fip->lock);
+	mutex_lock(&fip->ctlr_mutex);
 	fcoe_ctlr_reset(fip);
 	link_dropped = fip->state != FIP_ST_LINK_WAIT;
 	fip->state = FIP_ST_LINK_WAIT;
-	spin_unlock_bh(&fip->lock);
+	mutex_unlock(&fip->ctlr_mutex);
 
 	if (link_dropped)
 		fc_linkdown(fip->lp);
@@ -577,12 +577,12 @@ static unsigned long fcoe_ctlr_age_fcfs(struct fcoe_ctlr *fip)
 	unsigned long sel_time = 0;
 	struct fcoe_dev_stats *stats;
 
+	stats = per_cpu_ptr(fip->lp->dev_stats, get_cpu());
+
 	list_for_each_entry_safe(fcf, next, &fip->fcfs, list) {
 		deadline = fcf->time + fcf->fka_period + fcf->fka_period / 2;
 		if (fip->sel_fcf == fcf) {
 			if (time_after(jiffies, deadline)) {
-				stats = per_cpu_ptr(fip->lp->dev_stats,
-						    smp_processor_id());
 				stats->MissDiscAdvCount++;
 				printk(KERN_INFO "libfcoe: host%d: "
 				       "Missing Discovery Advertisement "
@@ -601,8 +601,6 @@ static unsigned long fcoe_ctlr_age_fcfs(struct fcoe_ctlr *fip)
 			WARN_ON(!fip->fcf_count);
 			fip->fcf_count--;
 			kfree(fcf);
-			stats = per_cpu_ptr(fip->lp->dev_stats,
-					    smp_processor_id());
 			stats->VLinkFailureCount++;
 		} else {
 			if (time_after(next_timer, deadline))
@@ -612,6 +610,7 @@ static unsigned long fcoe_ctlr_age_fcfs(struct fcoe_ctlr *fip)
 				sel_time = fcf->time;
 		}
 	}
+	put_cpu();
 	if (sel_time && !fip->sel_fcf && !fip->sel_time) {
 		sel_time += msecs_to_jiffies(FCOE_CTLR_START_DELAY);
 		fip->sel_time = sel_time;
@@ -768,7 +767,7 @@ static void fcoe_ctlr_recv_adv(struct fcoe_ctlr *fip, struct sk_buff *skb)
 	if (fcoe_ctlr_parse_adv(fip, skb, &new))
 		return;
 
-	spin_lock_bh(&fip->lock);
+	mutex_lock(&fip->ctlr_mutex);
 	first = list_empty(&fip->fcfs);
 	found = NULL;
 	list_for_each_entry(fcf, &fip->fcfs, list) {
@@ -847,7 +846,7 @@ static void fcoe_ctlr_recv_adv(struct fcoe_ctlr *fip, struct sk_buff *skb)
 			mod_timer(&fip->timer, fip->sel_time);
 	}
 out:
-	spin_unlock_bh(&fip->lock);
+	mutex_unlock(&fip->ctlr_mutex);
 }
 
 /**
@@ -1108,11 +1107,12 @@ static void fcoe_ctlr_recv_clr_vlink(struct fcoe_ctlr *fip,
 		if (is_vn_port)
 			fc_lport_reset(vn_port);
 		else {
-			spin_lock_bh(&fip->lock);
+			mutex_lock(&fip->ctlr_mutex);
 			per_cpu_ptr(lport->dev_stats,
-				    smp_processor_id())->VLinkFailureCount++;
+				    get_cpu())->VLinkFailureCount++;
+			put_cpu();
 			fcoe_ctlr_reset(fip);
-			spin_unlock_bh(&fip->lock);
+			mutex_unlock(&fip->ctlr_mutex);
 
 			fc_lport_reset(fip->lp);
 			fcoe_ctlr_solicit(fip, NULL);
@@ -1166,7 +1166,7 @@ static int fcoe_ctlr_recv_handler(struct fcoe_ctlr *fip, struct sk_buff *skb)
 	if (ntohs(fiph->fip_dl_len) * FIP_BPW + sizeof(*fiph) > skb->len)
 		goto drop;
 
-	spin_lock_bh(&fip->lock);
+	mutex_lock(&fip->ctlr_mutex);
 	state = fip->state;
 	if (state == FIP_ST_AUTO) {
 		fip->map_dest = 0;
@@ -1174,7 +1174,7 @@ static int fcoe_ctlr_recv_handler(struct fcoe_ctlr *fip, struct sk_buff *skb)
 		state = FIP_ST_ENABLED;
 		LIBFCOE_FIP_DBG(fip, "Using FIP mode\n");
 	}
-	spin_unlock_bh(&fip->lock);
+	mutex_unlock(&fip->ctlr_mutex);
 	if (state != FIP_ST_ENABLED)
 		goto drop;
 
@@ -1240,19 +1240,38 @@ static void fcoe_ctlr_select(struct fcoe_ctlr *fip)
 /**
  * fcoe_ctlr_timeout() - FIP timeout handler
  * @arg: The FCoE controller that timed out
- *
- * Ages FCFs.  Triggers FCF selection if possible.  Sends keep-alives.
  */
 static void fcoe_ctlr_timeout(unsigned long arg)
 {
 	struct fcoe_ctlr *fip = (struct fcoe_ctlr *)arg;
+
+	schedule_work(&fip->timer_work);
+}
+
+/**
+ * fcoe_ctlr_timer_work() - Worker thread function for timer work
+ * @work: Handle to a FCoE controller
+ *
+ * Ages FCFs.  Triggers FCF selection if possible.
+ * Sends keep-alives and resets.
+ */
+static void fcoe_ctlr_timer_work(struct work_struct *work)
+{
+	struct fcoe_ctlr *fip;
+	struct fc_lport *vport;
+	u8 *mac;
+	u8 reset = 0;
+	u8 send_ctlr_ka = 0;
+	u8 send_port_ka = 0;
 	struct fcoe_fcf *sel;
 	struct fcoe_fcf *fcf;
 	unsigned long next_timer;
 
-	spin_lock_bh(&fip->lock);
+	fip = container_of(work, struct fcoe_ctlr, timer_work);
+
+	mutex_lock(&fip->ctlr_mutex);
 	if (fip->state == FIP_ST_DISABLED) {
-		spin_unlock_bh(&fip->lock);
+		mutex_unlock(&fip->ctlr_mutex);
 		return;
 	}
 
@@ -1286,7 +1305,7 @@ static void fcoe_ctlr_timeout(unsigned long arg)
 			       "FIP Fibre-Channel Forwarder timed out.	"
 			       "Starting FCF discovery.\n",
 			       fip->lp->host->host_no);
-			fip->reset_req = 1;
+			reset = 1;
 			schedule_work(&fip->timer_work);
 		}
 	}
@@ -1294,7 +1313,7 @@ static void fcoe_ctlr_timeout(unsigned long arg)
 	if (sel && !sel->fd_flags) {
 		if (time_after_eq(jiffies, fip->ctlr_ka_time)) {
 			fip->ctlr_ka_time = jiffies + sel->fka_period;
-			fip->send_ctlr_ka = 1;
+			send_ctlr_ka = 1;
 		}
 		if (time_after(next_timer, fip->ctlr_ka_time))
 			next_timer = fip->ctlr_ka_time;
@@ -1302,37 +1321,14 @@ static void fcoe_ctlr_timeout(unsigned long arg)
 		if (time_after_eq(jiffies, fip->port_ka_time)) {
 			fip->port_ka_time = jiffies +
 				msecs_to_jiffies(FIP_VN_KA_PERIOD);
-			fip->send_port_ka = 1;
+			send_port_ka = 1;
 		}
 		if (time_after(next_timer, fip->port_ka_time))
 			next_timer = fip->port_ka_time;
 	}
 	if (!list_empty(&fip->fcfs))
 		mod_timer(&fip->timer, next_timer);
-	if (fip->send_ctlr_ka || fip->send_port_ka)
-		schedule_work(&fip->timer_work);
-	spin_unlock_bh(&fip->lock);
-}
-
-/**
- * fcoe_ctlr_timer_work() - Worker thread function for timer work
- * @work: Handle to a FCoE controller
- *
- * Sends keep-alives and resets which must not
- * be called from the timer directly, since they use a mutex.
- */
-static void fcoe_ctlr_timer_work(struct work_struct *work)
-{
-	struct fcoe_ctlr *fip;
-	struct fc_lport *vport;
-	u8 *mac;
-	int reset;
-
-	fip = container_of(work, struct fcoe_ctlr, timer_work);
-	spin_lock_bh(&fip->lock);
-	reset = fip->reset_req;
-	fip->reset_req = 0;
-	spin_unlock_bh(&fip->lock);
+	mutex_unlock(&fip->ctlr_mutex);
 
 	if (reset) {
 		fc_lport_reset(fip->lp);
@@ -1340,12 +1336,10 @@ static void fcoe_ctlr_timer_work(struct work_struct *work)
 		fcoe_ctlr_solicit(fip, NULL);
 	}
 
-	if (fip->send_ctlr_ka) {
-		fip->send_ctlr_ka = 0;
+	if (send_ctlr_ka)
 		fcoe_ctlr_send_keep_alive(fip, NULL, 0, fip->ctl_src_addr);
-	}
-	if (fip->send_port_ka) {
-		fip->send_port_ka = 0;
+
+	if (send_port_ka) {
 		mutex_lock(&fip->lp->lp_mutex);
 		mac = fip->get_src_addr(fip->lp);
 		fcoe_ctlr_send_keep_alive(fip, fip->lp, 1, mac);
@@ -1402,9 +1396,9 @@ int fcoe_ctlr_recv_flogi(struct fcoe_ctlr *fip, struct fc_lport *lport,
 	if (op == ELS_LS_ACC && fh->fh_r_ctl == FC_RCTL_ELS_REP &&
 	    fip->flogi_oxid == ntohs(fh->fh_ox_id)) {
 
-		spin_lock_bh(&fip->lock);
+		mutex_lock(&fip->ctlr_mutex);
 		if (fip->state != FIP_ST_AUTO && fip->state != FIP_ST_NON_FIP) {
-			spin_unlock_bh(&fip->lock);
+			mutex_unlock(&fip->ctlr_mutex);
 			return -EINVAL;
 		}
 		fip->state = FIP_ST_NON_FIP;
@@ -1424,13 +1418,13 @@ int fcoe_ctlr_recv_flogi(struct fcoe_ctlr *fip, struct fc_lport *lport,
 			fip->map_dest = 0;
 		}
 		fip->flogi_oxid = FC_XID_UNKNOWN;
-		spin_unlock_bh(&fip->lock);
+		mutex_unlock(&fip->ctlr_mutex);
 		fc_fcoe_set_mac(fr_cb(fp)->granted_mac, fh->fh_d_id);
 	} else if (op == ELS_FLOGI && fh->fh_r_ctl == FC_RCTL_ELS_REQ && sa) {
 		/*
 		 * Save source MAC for point-to-point responses.
 		 */
-		spin_lock_bh(&fip->lock);
+		mutex_lock(&fip->ctlr_mutex);
 		if (fip->state == FIP_ST_AUTO || fip->state == FIP_ST_NON_FIP) {
 			memcpy(fip->dest_addr, sa, ETH_ALEN);
 			fip->map_dest = 0;
@@ -1439,7 +1433,7 @@ int fcoe_ctlr_recv_flogi(struct fcoe_ctlr *fip, struct fc_lport *lport,
 						"Setting non-FIP mode\n");
 			fip->state = FIP_ST_NON_FIP;
 		}
-		spin_unlock_bh(&fip->lock);
+		mutex_unlock(&fip->ctlr_mutex);
 	}
 	return 0;
 }