Make scsi_free_queue() kill pending SCSI commands
commit 3308511c93e6ad0d3c58984ecd6e5e57f96b12c8 upstream.
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: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 28d9c9d..f97acff 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1697,6 +1697,15 @@
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);
}