ide: locking improvements

Index: b/drivers/ide/ide-io.c
===================================================================
@@ -1363,14 +1363,13 @@ irqreturn_t ide_intr (int irq, void *dev
 	ide_drive_t *drive;
 	ide_handler_t *handler;
 	ide_startstop_t startstop;
+	irqreturn_t irq_ret = IRQ_NONE;
 
 	spin_lock_irqsave(&ide_lock, flags);
 	hwif = hwgroup->hwif;
 
-	if (!ide_ack_intr(hwif)) {
-		spin_unlock_irqrestore(&ide_lock, flags);
-		return IRQ_NONE;
-	}
+	if (!ide_ack_intr(hwif))
+		goto out;
 
 	if ((handler = hwgroup->handler) == NULL || hwgroup->polling) {
 		/*

@@ -1406,9 +1405,9 @@ irqreturn_t ide_intr (int irq, void *dev
 			(void)hwif->tp_ops->read_status(hwif);
 #endif /* CONFIG_BLK_DEV_IDEPCI */
 		}
-		spin_unlock_irqrestore(&ide_lock, flags);
-		return IRQ_NONE;
+		goto out;
 	}
+
 	drive = hwgroup->drive;
 	if (!drive) {
 		/*

@@ -1417,10 +1416,10 @@ irqreturn_t ide_intr (int irq, void *dev
 		 *
 		 * [Note - this can occur if the drive is hot unplugged]
 		 */
-		spin_unlock_irqrestore(&ide_lock, flags);
-		return IRQ_HANDLED;
+		goto out_handled;
 	}
-	if (!drive_is_ready(drive)) {
+
+	if (!drive_is_ready(drive))
 		/*
 		 * This happens regularly when we share a PCI IRQ with
 		 * another device.  Unfortunately, it can also happen

@@ -1428,9 +1427,8 @@ irqreturn_t ide_intr (int irq, void *dev
 		 * their status register is up to date.  Hopefully we have
 		 * enough advance overhead that the latter isn't a problem.
 		 */
-		spin_unlock_irqrestore(&ide_lock, flags);
-		return IRQ_NONE;
-	}
+		goto out;
+
 	if (!hwgroup->busy) {
 		hwgroup->busy = 1;	/* paranoia */
 		printk(KERN_ERR "%s: ide_intr: hwgroup->busy was 0 ??\n", drive->name);

@@ -1467,8 +1465,11 @@ irqreturn_t ide_intr (int irq, void *dev
 				"on exit\n", drive->name);
 		}
 	}
+out_handled:
+	irq_ret = IRQ_HANDLED;
+out:
 	spin_unlock_irqrestore(&ide_lock, flags);
-	return IRQ_HANDLED;
+	return irq_ret;
 }
 
 /**

Index: b/drivers/ide/ide-ioctls.c
===================================================================
@@ -19,7 +19,6 @@ int ide_setting_ioctl(ide_drive_t *drive
 		      const struct ide_ioctl_devset *s)
 {
 	const struct ide_devset *ds;
-	unsigned long flags;
 	int err = -EOPNOTSUPP;
 
 	for (; (ds = s->setting); s++) {

@@ -33,9 +32,7 @@ int ide_setting_ioctl(ide_drive_t *drive
 
 read_val:
 	mutex_lock(&ide_setting_mtx);
-	spin_lock_irqsave(&ide_lock, flags);
 	err = ds->get(drive);
-	spin_unlock_irqrestore(&ide_lock, flags);
 	mutex_unlock(&ide_setting_mtx);
 	return err >= 0 ? put_user(err, (long __user *)arg) : err;
 

Index: b/drivers/ide/ide-proc.c
===================================================================
@@ -155,13 +155,8 @@ static int ide_read_setting(ide_drive_t 
 	const struct ide_devset *ds = setting->setting;
 	int val = -EINVAL;
 
-	if (ds->get) {
-		unsigned long flags;
-
-		spin_lock_irqsave(&ide_lock, flags);
+	if (ds->get)
 		val = ds->get(drive);
-		spin_unlock_irqrestore(&ide_lock, flags);
-	}
 
 	return val;
 }

@@ -583,31 +578,19 @@ EXPORT_SYMBOL(ide_proc_register_driver);
  *	Clean up the driver specific /proc files and IDE settings
  *	for a given drive.
  *
- *	Takes ide_setting_mtx and ide_lock.
- *	Caller must hold none of the locks.
+ *	Takes ide_setting_mtx.
  */
 
 void ide_proc_unregister_driver(ide_drive_t *drive, ide_driver_t *driver)
 {
-	unsigned long flags;
-
 	ide_remove_proc_entries(drive->proc, driver->proc_entries(drive));
 
 	mutex_lock(&ide_setting_mtx);
-	spin_lock_irqsave(&ide_lock, flags);
 	/*
-	 * ide_setting_mtx protects the settings list
-	 * ide_lock protects the use of settings
-	 *
-	 * so we need to hold both, ide_settings_sem because we want to
-	 * modify the settings list, and ide_lock because we cannot take
-	 * a setting out that is being used.
-	 *
-	 * OTOH both ide_{read,write}_setting are only ever used under
-	 * ide_setting_mtx.
+	 * ide_setting_mtx protects both the settings list and the use
+	 * of settings (we cannot take a setting out that is being used).
 	 */
 	drive->settings = NULL;
-	spin_unlock_irqrestore(&ide_lock, flags);
 	mutex_unlock(&ide_setting_mtx);
 }
 EXPORT_SYMBOL(ide_proc_unregister_driver);

Index: b/drivers/ide/ide.c
===================================================================
@@ -130,7 +130,6 @@
 	}
 }
 
-/* Called with ide_lock held. */
 static void __ide_port_unregister_devices(ide_hwif_t *hwif)
 {
 	int i;

@@ -139,10 +138,8 @@
 		ide_drive_t *drive = &hwif->drives[i];
 
 		if (drive->dev_flags & IDE_DFLAG_PRESENT) {
-			spin_unlock_irq(&ide_lock);
 			device_unregister(&drive->gendev);
 			wait_for_completion(&drive->gendev_rel_comp);
-			spin_lock_irq(&ide_lock);
 		}
 	}
 }

@@ -150,11 +147,9 @@
 void ide_port_unregister_devices(ide_hwif_t *hwif)
 {
 	mutex_lock(&ide_cfg_mtx);
-	spin_lock_irq(&ide_lock);
 	__ide_port_unregister_devices(hwif);
 	hwif->present = 0;
 	ide_port_init_devices_data(hwif);
-	spin_unlock_irq(&ide_lock);
 	mutex_unlock(&ide_cfg_mtx);
 }
 EXPORT_SYMBOL_GPL(ide_port_unregister_devices);

@@ -192,12 +187,10 @@
 
 	mutex_lock(&ide_cfg_mtx);
 
-	spin_lock_irq(&ide_lock);
 	if (hwif->present) {
 		__ide_port_unregister_devices(hwif);
 		hwif->present = 0;
 	}
-	spin_unlock_irq(&ide_lock);
 
 	ide_proc_unregister_port(hwif);
 

Index: b/drivers/ide/ide-cd.c
===================================================================
@@ -317,7 +317,8 @@ static void ide_dump_status_no_sense(ide
 static int cdrom_decode_status(ide_drive_t *drive, int good_stat, int *stat_ret)
 {
 	ide_hwif_t *hwif = drive->hwif;
-	struct request *rq = hwif->hwgroup->rq;
+	ide_hwgroup_t *hwgroup = hwif->hwgroup;
+	struct request *rq = hwgroup->rq;
 	int stat, err, sense_key;
 
 	/* check for errors */

@@ -508,9 +509,10 @@ end_request:
 
 		spin_lock_irqsave(&ide_lock, flags);
 		blkdev_dequeue_request(rq);
-		HWGROUP(drive)->rq = NULL;
 		spin_unlock_irqrestore(&ide_lock, flags);
 
+		hwgroup->rq = NULL;
+
 		cdrom_queue_request_sense(drive, rq->sense, rq);
 	} else
 		cdrom_end_request(drive, 0);

@@ -950,7 +952,8 @@ static int cdrom_newpc_intr_dummy_cb(str
 static ide_startstop_t cdrom_newpc_intr(ide_drive_t *drive)
 {
 	ide_hwif_t *hwif = drive->hwif;
-	struct request *rq = HWGROUP(drive)->rq;
+	ide_hwgroup_t *hwgroup = hwif->hwgroup;
+	struct request *rq = hwgroup->rq;
 	xfer_func_t *xferfunc;
 	ide_expiry_t *expiry = NULL;
 	int dma_error = 0, dma, stat, thislen, uptodate = 0;

@@ -1157,8 +1160,9 @@ end_request:
 		spin_lock_irqsave(&ide_lock, flags);
 		if (__blk_end_request(rq, 0, dlen))
 			BUG();
-		HWGROUP(drive)->rq = NULL;
 		spin_unlock_irqrestore(&ide_lock, flags);
+
+		hwgroup->rq = NULL;
 	} else {
 		if (!uptodate)
 			rq->cmd_flags |= REQ_FAILED;

Index: b/drivers/ide/ide-io.c
===================================================================
@@ -107,17 +107,10 @@ static int __ide_end_request(ide_drive_t
 int ide_end_request (ide_drive_t *drive, int uptodate, int nr_sectors)
 {
 	unsigned int nr_bytes = nr_sectors << 9;
-	struct request *rq;
+	struct request *rq = drive->hwif->hwgroup->rq;
 	unsigned long flags;
 	int ret = 1;
 
-	/*
-	 * room for locking improvements here, the calls below don't
-	 * need the queue lock held at all
-	 */
-	spin_lock_irqsave(&ide_lock, flags);
-	rq = HWGROUP(drive)->rq;
-
 	if (!nr_bytes) {
 		if (blk_pc_request(rq))
 			nr_bytes = rq->data_len;

@@ -125,9 +118,10 @@ int ide_end_request (ide_drive_t *drive,
 			nr_bytes = rq->hard_cur_sectors << 9;
 	}
 
+	spin_lock_irqsave(&ide_lock, flags);
 	ret = __ide_end_request(drive, rq, uptodate, nr_bytes, 1);
-
 	spin_unlock_irqrestore(&ide_lock, flags);
+
 	return ret;
 }
 EXPORT_SYMBOL(ide_end_request);

@@ -241,8 +235,9 @@ int ide_end_dequeued_request(ide_drive_t
 	unsigned long flags;
 	int ret;
 
-	spin_lock_irqsave(&ide_lock, flags);
 	BUG_ON(!blk_rq_started(rq));
+
+	spin_lock_irqsave(&ide_lock, flags);
 	ret = __ide_end_request(drive, rq, uptodate, nr_sectors << 9, 0);
 	spin_unlock_irqrestore(&ide_lock, flags);
 

@@ -274,7 +269,11 @@ static void ide_complete_pm_request (ide
 		drive->dev_flags &= ~IDE_DFLAG_BLOCKED;
 		blk_start_queue(drive->queue);
 	}
-	HWGROUP(drive)->rq = NULL;
+	spin_unlock_irqrestore(&ide_lock, flags);
+
+	drive->hwif->hwgroup->rq = NULL;
+
+	spin_lock_irqsave(&ide_lock, flags);
 	if (__blk_end_request(rq, 0, 0))
 		BUG();
 	spin_unlock_irqrestore(&ide_lock, flags);

@@ -296,12 +295,9 @@ static void ide_complete_pm_request (ide
  
 void ide_end_drive_cmd (ide_drive_t *drive, u8 stat, u8 err)
 {
+	ide_hwgroup_t *hwgroup = drive->hwif->hwgroup;
+	struct request *rq = hwgroup->rq;
 	unsigned long flags;
-	struct request *rq;
-
-	spin_lock_irqsave(&ide_lock, flags);
-	rq = HWGROUP(drive)->rq;
-	spin_unlock_irqrestore(&ide_lock, flags);
 
 	if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE) {
 		ide_task_t *task = (ide_task_t *)rq->special;

@@ -332,15 +328,16 @@ void ide_end_drive_cmd (ide_drive_t *dri
 		return;
 	}
 
-	spin_lock_irqsave(&ide_lock, flags);
-	HWGROUP(drive)->rq = NULL;
+	hwgroup->rq = NULL;
+
 	rq->errors = err;
+
+	spin_lock_irqsave(&ide_lock, flags);
 	if (unlikely(__blk_end_request(rq, (rq->errors ? -EIO : 0),
 				       blk_rq_bytes(rq))))
 		BUG();
 	spin_unlock_irqrestore(&ide_lock, flags);
 }
-
 EXPORT_SYMBOL(ide_end_drive_cmd);
 
 static void ide_kill_rq(ide_drive_t *drive, struct request *rq)

@@ -1489,11 +1486,12 @@ out:
 
 void ide_do_drive_cmd(ide_drive_t *drive, struct request *rq)
 {
+	ide_hwgroup_t *hwgroup = drive->hwif->hwgroup;
 	unsigned long flags;
-	ide_hwgroup_t *hwgroup = HWGROUP(drive);
 
-	spin_lock_irqsave(&ide_lock, flags);
 	hwgroup->rq = NULL;
+
+	spin_lock_irqsave(&ide_lock, flags);
 	__elv_add_request(drive->queue, rq, ELEVATOR_INSERT_FRONT, 1);
 	__generic_unplug_device(drive->queue);
 	spin_unlock_irqrestore(&ide_lock, flags);

Index: b/drivers/ide/ide-lib.c
===================================================================
@@ -277,14 +277,9 @@ int ide_set_xfer_rate(ide_drive_t *drive
 
 static void ide_dump_opcode(ide_drive_t *drive)
 {
-	struct request *rq;
+	struct request *rq = drive->hwif->hwgroup->rq;
 	ide_task_t *task = NULL;
 
-	spin_lock(&ide_lock);
-	rq = NULL;
-	if (HWGROUP(drive))
-		rq = HWGROUP(drive)->rq;
-	spin_unlock(&ide_lock);
 	if (!rq)
 		return;
 

Index: b/drivers/ide/ide-io.c
===================================================================
@@ -58,6 +58,7 @@
 static int __ide_end_request(ide_drive_t *drive, struct request *rq,
 			     int uptodate, unsigned int nr_bytes, int dequeue)
 {
+	unsigned long flags;
 	int ret = 1;
 	int error = 0;
 

@@ -84,11 +85,13 @@ static int __ide_end_request(ide_drive_t
 		ide_dma_on(drive);
 	}
 
-	if (!__blk_end_request(rq, error, nr_bytes)) {
-		if (dequeue)
-			HWGROUP(drive)->rq = NULL;
+	spin_lock_irqsave(&ide_lock, flags);
+	if (!__blk_end_request(rq, error, nr_bytes))
 		ret = 0;
-	}
+	spin_unlock_irqrestore(&ide_lock, flags);
+
+	if (ret == 0 && dequeue)
+		drive->hwif->hwgroup->rq = NULL;
 
 	return ret;
 }

@@ -108,8 +111,6 @@ int ide_end_request (ide_drive_t *drive,
 {
 	unsigned int nr_bytes = nr_sectors << 9;
 	struct request *rq = drive->hwif->hwgroup->rq;
-	unsigned long flags;
-	int ret = 1;
 
 	if (!nr_bytes) {
 		if (blk_pc_request(rq))

@@ -118,11 +119,7 @@ int ide_end_request (ide_drive_t *drive,
 			nr_bytes = rq->hard_cur_sectors << 9;
 	}
 
-	spin_lock_irqsave(&ide_lock, flags);
-	ret = __ide_end_request(drive, rq, uptodate, nr_bytes, 1);
-	spin_unlock_irqrestore(&ide_lock, flags);
-
-	return ret;
+	return __ide_end_request(drive, rq, uptodate, nr_bytes, 1);
 }
 EXPORT_SYMBOL(ide_end_request);
 

@@ -232,16 +229,9 @@ out_do_tf:
 int ide_end_dequeued_request(ide_drive_t *drive, struct request *rq,
 			     int uptodate, int nr_sectors)
 {
-	unsigned long flags;
-	int ret;
-
 	BUG_ON(!blk_rq_started(rq));
 
-	spin_lock_irqsave(&ide_lock, flags);
-	ret = __ide_end_request(drive, rq, uptodate, nr_sectors << 9, 0);
-	spin_unlock_irqrestore(&ide_lock, flags);
-
-	return ret;
+	return __ide_end_request(drive, rq, uptodate, nr_sectors << 9, 0);
 }
 EXPORT_SYMBOL_GPL(ide_end_dequeued_request);
 

Index: b/drivers/ide/ide-cd.c
===================================================================
@@ -262,7 +262,6 @@ static void cdrom_end_request(ide_drive_
 		struct request *failed = (struct request *) rq->buffer;
 		struct cdrom_info *info = drive->driver_data;
 		void *sense = &info->sense_data;
-		unsigned long flags;
 
 		if (failed) {
 			if (failed->sense) {

@@ -278,11 +277,9 @@ static void cdrom_end_request(ide_drive_
 						failed->hard_nr_sectors))
 					BUG();
 			} else {
-				spin_lock_irqsave(&ide_lock, flags);
-				if (__blk_end_request(failed, -EIO,
-						      failed->data_len))
+				if (blk_end_request(failed, -EIO,
+						    failed->data_len))
 					BUG();
-				spin_unlock_irqrestore(&ide_lock, flags);
 			}
 		} else
 			cdrom_analyze_sense_data(drive, NULL, sense);

@@ -1151,16 +1148,13 @@ static ide_startstop_t cdrom_newpc_intr(
 
 end_request:
 	if (blk_pc_request(rq)) {
-		unsigned long flags;
 		unsigned int dlen = rq->data_len;
 
 		if (dma)
 			rq->data_len = 0;
 
-		spin_lock_irqsave(&ide_lock, flags);
-		if (__blk_end_request(rq, 0, dlen))
+		if (blk_end_request(rq, 0, dlen))
 			BUG();
-		spin_unlock_irqrestore(&ide_lock, flags);
 
 		hwgroup->rq = NULL;
 	} else {

Index: b/drivers/ide/ide-io.c
===================================================================
@@ -58,7 +58,6 @@
 static int __ide_end_request(ide_drive_t *drive, struct request *rq,
 			     int uptodate, unsigned int nr_bytes, int dequeue)
 {
-	unsigned long flags;
 	int ret = 1;
 	int error = 0;
 

@@ -85,10 +84,8 @@ static int __ide_end_request(ide_drive_t
 		ide_dma_on(drive);
 	}
 
-	spin_lock_irqsave(&ide_lock, flags);
-	if (!__blk_end_request(rq, error, nr_bytes))
+	if (!blk_end_request(rq, error, nr_bytes))
 		ret = 0;
-	spin_unlock_irqrestore(&ide_lock, flags);
 
 	if (ret == 0 && dequeue)
 		drive->hwif->hwgroup->rq = NULL;

@@ -263,10 +260,8 @@ static void ide_complete_pm_request (ide
 
 	drive->hwif->hwgroup->rq = NULL;
 
-	spin_lock_irqsave(&ide_lock, flags);
-	if (__blk_end_request(rq, 0, 0))
+	if (blk_end_request(rq, 0, 0))
 		BUG();
-	spin_unlock_irqrestore(&ide_lock, flags);
 }
 
 /**

@@ -287,7 +282,6 @@ void ide_end_drive_cmd (ide_drive_t *dri
 {
 	ide_hwgroup_t *hwgroup = drive->hwif->hwgroup;
 	struct request *rq = hwgroup->rq;
-	unsigned long flags;
 
 	if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE) {
 		ide_task_t *task = (ide_task_t *)rq->special;

@@ -322,11 +316,9 @@ void ide_end_drive_cmd (ide_drive_t *dri
 
 	rq->errors = err;
 
-	spin_lock_irqsave(&ide_lock, flags);
-	if (unlikely(__blk_end_request(rq, (rq->errors ? -EIO : 0),
-				       blk_rq_bytes(rq))))
+	if (unlikely(blk_end_request(rq, (rq->errors ? -EIO : 0),
+				     blk_rq_bytes(rq))))
 		BUG();
-	spin_unlock_irqrestore(&ide_lock, flags);
 }
 EXPORT_SYMBOL(ide_end_drive_cmd);
 

Index: b/drivers/ide/ide-cd.c
===================================================================
@@ -424,16 +424,17 @@ static int cdrom_decode_status(ide_drive
 				if (time_after(jiffies, info->write_timeout))
 					do_end_request = 1;
 				else {
+					struct request_queue *q = drive->queue;
 					unsigned long flags;
 
 					/*
 					 * take a breather relying on the unplug
 					 * timer to kick us again
 					 */
-					spin_lock_irqsave(&ide_lock, flags);
-					blk_plug_device(drive->queue);
-					spin_unlock_irqrestore(&ide_lock,
-								flags);
+					spin_lock_irqsave(q->queue_lock, flags);
+					blk_plug_device(q);
+					spin_unlock_irqrestore(q->queue_lock, flags);
+
 					return 1;
 				}
 			}

@@ -502,11 +503,12 @@ static int cdrom_decode_status(ide_drive
 
 end_request:
 	if (stat & ATA_ERR) {
+		struct request_queue *q = drive->queue;
 		unsigned long flags;
 
-		spin_lock_irqsave(&ide_lock, flags);
+		spin_lock_irqsave(q->queue_lock, flags);
 		blkdev_dequeue_request(rq);
-		spin_unlock_irqrestore(&ide_lock, flags);
+		spin_unlock_irqrestore(q->queue_lock, flags);
 
 		hwgroup->rq = NULL;
 

Index: b/drivers/ide/ide-io.c
===================================================================
@@ -243,20 +243,21 @@ EXPORT_SYMBOL_GPL(ide_end_dequeued_reque
  */
 static void ide_complete_pm_request (ide_drive_t *drive, struct request *rq)
 {
+	struct request_queue *q = drive->queue;
 	unsigned long flags;
 
 #ifdef DEBUG_PM
 	printk("%s: completing PM request, %s\n", drive->name,
 	       blk_pm_suspend_request(rq) ? "suspend" : "resume");
 #endif
-	spin_lock_irqsave(&ide_lock, flags);
+	spin_lock_irqsave(q->queue_lock, flags);
 	if (blk_pm_suspend_request(rq)) {
-		blk_stop_queue(drive->queue);
+		blk_stop_queue(q);
 	} else {
 		drive->dev_flags &= ~IDE_DFLAG_BLOCKED;
-		blk_start_queue(drive->queue);
+		blk_start_queue(q);
 	}
-	spin_unlock_irqrestore(&ide_lock, flags);
+	spin_unlock_irqrestore(q->queue_lock, flags);
 
 	drive->hwif->hwgroup->rq = NULL;
 

@@ -1469,16 +1470,16 @@ out:
 void ide_do_drive_cmd(ide_drive_t *drive, struct request *rq)
 {
 	ide_hwgroup_t *hwgroup = drive->hwif->hwgroup;
+	struct request_queue *q = drive->queue;
 	unsigned long flags;
 
 	hwgroup->rq = NULL;
 
-	spin_lock_irqsave(&ide_lock, flags);
-	__elv_add_request(drive->queue, rq, ELEVATOR_INSERT_FRONT, 1);
-	__generic_unplug_device(drive->queue);
-	spin_unlock_irqrestore(&ide_lock, flags);
+	spin_lock_irqsave(q->queue_lock, flags);
+	__elv_add_request(q, rq, ELEVATOR_INSERT_FRONT, 1);
+	__generic_unplug_device(q);
+	spin_unlock_irqrestore(q->queue_lock, flags);
 }
-
 EXPORT_SYMBOL(ide_do_drive_cmd);
 
 void ide_pktcmd_tf_load(ide_drive_t *drive, u32 tf_flags, u16 bcount, u8 dma)