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

  cd43e26f07

  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>
This commit is contained in:
Ed Cashin 2009-09-09 14:10:18 +02:00 committed by Jens Axboe
parent e6890f6f3d
commit 7135a71b19
3 changed files with 11 additions and 4 deletions

View file

@ -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;

View file

@ -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:

View file

@ -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);
}