Re: [ck] 2.6.11-ck6

[Con Kolivas]

On Sun, 1 May 2005 10:14, Con Kolivas wrote:
> On Sun, 1 May 2005 06:13, Jens Axboe wrote:
> > On Sun, May 01 2005, Con Kolivas wrote:
> > > +scsi-dead-device.diff
> > > A fix for a scsi related hang that seems to hit many -ck users
> >
> > This looks strange, like a fix and a half. You should just apply the
> > patch I sent you originally, weeks ago, changing sdev->sdev_lock to
> > &q->__queue_lock.
>
> rarrgh
>
> Thanks for keeping an eye out on for this. Unfortunately you sent more than
> one patch at different times and it looks like I included the wrong one
> then? This is the patch I (tried to) include.

I guess from your description this was the one I should have included... Looks 
like a ck7 should come out instead since that other patch was more likely 
harmful than not :\

Con
===== drivers/block/ll_rw_blk.c 1.288 vs edited =====
--- 1.288/drivers/block/ll_rw_blk.c	2005-03-31 12:47:54 +02:00
+++ edited/drivers/block/ll_rw_blk.c	2005-04-07 08:38:01 +02:00
@@ -1714,6 +1711,15 @@ request_queue_t *blk_init_queue(request_
 	if (blk_init_free_list(q))
 		goto out_init;
 
+	/*
+	 * if caller didn't supply a lock, they get per-queue locking with
+	 * our embedded lock
+	 */
+	if (!lock) {
+		spin_lock_init(&q->__queue_lock);
+		lock = &q->__queue_lock;
+	}
+
 	q->request_fn		= rfn;
 	q->back_merge_fn       	= ll_back_merge_fn;
 	q->front_merge_fn      	= ll_front_merge_fn;
===== drivers/scsi/scsi_lib.c 1.153 vs edited =====
--- 1.153/drivers/scsi/scsi_lib.c	2005-03-30 21:49:45 +02:00
+++ edited/drivers/scsi/scsi_lib.c	2005-04-07 08:42:30 +02:00
@@ -360,9 +360,9 @@ void scsi_device_unbusy(struct scsi_devi
 		     shost->host_failed))
 		scsi_eh_wakeup(shost);
 	spin_unlock(shost->host_lock);
-	spin_lock(&sdev->sdev_lock);
+	spin_lock(sdev->request_queue->queue_lock);
 	sdev->device_busy--;
-	spin_unlock_irqrestore(&sdev->sdev_lock, flags);
+	spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
 }
 
 /*
@@ -1425,7 +1425,7 @@ struct request_queue *scsi_alloc_queue(s
 	struct Scsi_Host *shost = sdev->host;
 	struct request_queue *q;
 
-	q = blk_init_queue(scsi_request_fn, &sdev->sdev_lock);
+	q = blk_init_queue(scsi_request_fn, NULL);
 	if (!q)
 		return NULL;
 
===== drivers/scsi/scsi_scan.c 1.143 vs edited =====
--- 1.143/drivers/scsi/scsi_scan.c	2005-03-23 22:58:13 +01:00
+++ edited/drivers/scsi/scsi_scan.c	2005-04-07 08:40:53 +02:00
@@ -249,7 +249,6 @@ static struct scsi_device *scsi_alloc_sd
 	 */
 	sdev->borken = 1;
 
-	spin_lock_init(&sdev->sdev_lock);
 	sdev->request_queue = scsi_alloc_queue(sdev);
 	if (!sdev->request_queue) {
 		/* release fn is set up in scsi_sysfs_device_initialise, so
===== include/linux/blkdev.h 1.162 vs edited =====
--- 1.162/include/linux/blkdev.h	2005-03-29 03:42:37 +02:00
+++ edited/include/linux/blkdev.h	2005-04-07 08:36:06 +02:00
@@ -355,8 +364,11 @@ struct request_queue
 	unsigned long		queue_flags;
 
 	/*
-	 * protects queue structures from reentrancy
+	 * protects queue structures from reentrancy. ->__queue_lock should
+	 * _never_ be used directly, it is queue private. always use
+	 * ->queue_lock.
 	 */
+	spinlock_t		__queue_lock;
 	spinlock_t		*queue_lock;
 
 	/*
===== include/scsi/scsi_device.h 1.33 vs edited =====
--- 1.33/include/scsi/scsi_device.h	2005-03-23 22:58:05 +01:00
+++ edited/include/scsi/scsi_device.h	2005-04-07 08:41:09 +02:00
@@ -44,7 +44,6 @@ struct scsi_device {
 	struct list_head    same_target_siblings; /* just the devices sharing same target id */
 
 	volatile unsigned short device_busy;	/* commands actually active on low-level */
-	spinlock_t sdev_lock;           /* also the request queue_lock */
 	spinlock_t list_lock;
 	struct list_head cmd_list;	/* queue of in use SCSI Command structures */
 	struct list_head starved_entry;

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