From: James Bottomley Date: Wed, 25 May 2011 20:52:14 +0000 (-0500) Subject: Fix oops caused by queue refcounting failure X-Git-Tag: v2.6.35.14~111 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d4df7c4751eefc0130f4f8bdf396a4ea16876dd4;p=thirdparty%2Fkernel%2Fstable.git Fix oops caused by queue refcounting failure commit e73e079bf128d68284efedeba1fbbc18d78610f9 upstream. In certain circumstances, we can get an oops from a torn down device. Most notably this is from CD roms trying to call scsi_ioctl. The root cause of the problem is the fact that after scsi_remove_device() has been called, the queue is fully torn down. This is actually wrong since the queue can be used until the sdev release function is called. Therefore, we add an extra reference to the queue which is released in sdev->release, so the queue always exists. Reported-by: Parag Warudkar Signed-off-by: James Bottomley Signed-off-by: Greg Kroah-Hartman Signed-off-by: Andi Kleen --- diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c index 1c027a97d8b9e..6765188ca8160 100644 --- a/drivers/scsi/scsi_scan.c +++ b/drivers/scsi/scsi_scan.c @@ -295,7 +295,7 @@ static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget, kfree(sdev); goto out; } - + blk_get_queue(sdev->request_queue); sdev->request_queue->queuedata = sdev; scsi_adjust_queue_depth(sdev, 0, sdev->host->cmd_per_lun); diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c index 2b265a16e92fc..0ed2365d04f11 100644 --- a/drivers/scsi/scsi_sysfs.c +++ b/drivers/scsi/scsi_sysfs.c @@ -319,6 +319,7 @@ static void scsi_device_dev_release_usercontext(struct work_struct *work) kfree(evt); } + blk_put_queue(sdev->request_queue); /* NULL queue means the device can't be used */ sdev->request_queue = NULL;