Commit 7135a71b authored Sep 09, 2009 by Ed Cashin Committed by Jens Axboe Sep 09, 2009

aoe: allocate unused request_queue for sysfs

Andy Whitcroft reported an oops in aoe triggered by use of an
incorrectly initialised request_queue object:

  [ 2645.959090] kobject '<NULL>' (ffff880059ca22c0): tried to add
		an uninitialized object, something is seriously wrong.
  [ 2645.959104] Pid: 6, comm: events/0 Not tainted 2.6.31-5-generic #24-Ubuntu
  [ 2645.959107] Call Trace:
  [ 2645.959139] [<ffffffff8126ca2f>] kobject_add+0x5f/0x70
  [ 2645.959151] [<ffffffff8125b4ab>] blk_register_queue+0x8b/0xf0
  [ 2645.959155] [<ffffffff8126043f>] add_disk+0x8f/0x160
  [ 2645.959161] [<ffffffffa01673c4>] aoeblk_gdalloc+0x164/0x1c0 [aoe]

The request queue of an aoe device is not used but can be allocated in
code that does not sleep.

Bruno bisected this regression down to

  cd43e26f

  block: Expose stacked device queues in sysfs

"This seems to generate /sys/block/$device/queue and its contents for
 everyone who is using queues, not just for those queues that have a
 non-NULL queue->request_fn."

Addresses http://bugs.launchpad.net/bugs/410198
Addresses http://bugzilla.kernel.org/show_bug.cgi?id=13942



Note that embedding a queue inside another object has always been
an illegal construct, since the queues are reference counted and
must persist until the last reference is dropped. So aoe was
always buggy in this respect (Jens).

Signed-off-by: Ed Cashin <ecashin@coraid.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Bruno Premont <bonbons@linux-vserver.org>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

parent e6890f6f

drivers/block/aoe/aoe.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -155,7 +155,7 @@ struct aoedev {
		u16 fw_ver; /* version of blade's firmware */
		struct work_struct work;/* disk create work struct */
		struct gendisk *gd;
		struct request_queue blkq;
		struct request_queue *blkq;
		struct hd_geometry geo;
		sector_t ssize;
		struct timer_list timer;

drivers/block/aoe/aoeblk.c

+9 −3

Original line number	Diff line number	Diff line
		@@ -264,9 +264,12 @@ aoeblk_gdalloc(void *vp)
		goto err_disk;
		}

		blk_queue_make_request(&d->blkq, aoeblk_make_request);
		if (bdi_init(&d->blkq.backing_dev_info))
		d->blkq = blk_alloc_queue(GFP_KERNEL);
		if (!d->blkq)
		goto err_mempool;
		blk_queue_make_request(d->blkq, aoeblk_make_request);
		if (bdi_init(&d->blkq->backing_dev_info))
		goto err_blkq;
		spin_lock_irqsave(&d->lock, flags);
		gd->major = AOE_MAJOR;
		gd->first_minor = d->sysminor * AOE_PARTITIONS;
		@@ -276,7 +279,7 @@ aoeblk_gdalloc(void *vp)
		snprintf(gd->disk_name, sizeof gd->disk_name, "etherd/e%ld.%d",
		d->aoemajor, d->aoeminor);

		gd->queue = &d->blkq;
		gd->queue = d->blkq;
		d->gd = gd;
		d->flags &= ~DEVFL_GDALLOC;
		d->flags \|= DEVFL_UP;
		@@ -287,6 +290,9 @@ aoeblk_gdalloc(void *vp)
		aoedisk_add_sysfs(d);
		return;

		err_blkq:
		blk_cleanup_queue(d->blkq);
		d->blkq = NULL;
		err_mempool:
		mempool_destroy(d->bufpool);
		err_disk:

drivers/block/aoe/aoedev.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -113,6 +113,7 @@ aoedev_freedev(struct aoedev *d)
		if (d->bufpool)
		mempool_destroy(d->bufpool);
		skbpoolfree(d);
		blk_cleanup_queue(d->blkq);
		kfree(d);
		}

Admin message