Commit 3308511c authored by Bart Van Assche's avatar Bart Van Assche Committed by James Bottomley
Browse files

[SCSI] Make scsi_free_queue() kill pending SCSI commands 

Make sure that SCSI device removal via scsi_remove_host() does finish
all pending SCSI commands. Currently that's not the case and hence
removal of a SCSI host during I/O can cause a deadlock. See also
"blkdev_issue_discard() hangs forever if underlying storage device is
removed" (http://bugzilla.kernel.org/show_bug.cgi?id=40472). See also
http://lkml.org/lkml/2011/8/27/6

.

Signed-off-by: default avatarBart Van Assche <bvanassche@acm.org>
Cc: <stable@kernel.org>
Signed-off-by: default avatarJames Bottomley <JBottomley@Parallels.com>
parent 21208ae5

drivers/scsi/hosts.c

+6 −3
Original line number Diff line number Diff line
@@ -286,6 +286,7 @@ static void scsi_host_dev_release(struct device *dev) 
{

	struct Scsi_Host *shost = dev_to_shost(dev);

	struct device *parent = dev->parent;

	struct request_queue *q;



	scsi_proc_hostdir_rm(shost->hostt);
@@ -293,9 +294,11 @@ static void scsi_host_dev_release(struct device *dev) 
		kthread_stop(shost->ehandler);

	if (shost->work_q)

		destroy_workqueue(shost->work_q);

	if (shost->uspace_req_q) {

		kfree(shost->uspace_req_q->queuedata);

		scsi_free_queue(shost->uspace_req_q);

	q = shost->uspace_req_q;

	if (q) {

		kfree(q->queuedata);

		q->queuedata = NULL;

		scsi_free_queue(q);

	}



	scsi_destroy_command_freelist(shost);

drivers/scsi/scsi_lib.c

+9 −0
Original line number Diff line number Diff line
@@ -1698,6 +1698,15 @@ struct request_queue *scsi_alloc_queue(struct scsi_device *sdev) 


void scsi_free_queue(struct request_queue *q)

{

	unsigned long flags;



	WARN_ON(q->queuedata);



	/* cause scsi_request_fn() to kill all non-finished requests */

	spin_lock_irqsave(q->queue_lock, flags);

	q->request_fn(q);

	spin_unlock_irqrestore(q->queue_lock, flags);



	blk_cleanup_queue(q);

}

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