From: Bart Van Assche Date: Fri, 23 Sep 2011 17:48:18 +0000 (+0200) Subject: Make scsi_free_queue() kill pending SCSI commands X-Git-Tag: v2.6.27.60~39 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=41503f12fe5f9ec58ae15845b30c1f3a3a4d68e2;p=thirdparty%2Fkernel%2Fstable.git 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 Signed-off-by: James Bottomley Signed-off-by: Greg Kroah-Hartman Signed-off-by: Willy Tarreau --- diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c index fed0b02ebc1d3..35953bfac2c34 100644 --- a/drivers/scsi/hosts.c +++ b/drivers/scsi/hosts.c @@ -269,14 +269,17 @@ 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; if (shost->ehandler) 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); diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 62307bd794a92..e34afc5a87790 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1680,6 +1680,15 @@ 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); }