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authorBart Van Assche <bvanassche@acm.org>2011-09-23 19:48:18 +0200
committerJames Bottomley <JBottomley@Parallels.com>2011-10-30 13:20:28 +0400
commit3308511c93e6ad0d3c58984ecd6e5e57f96b12c8 (patch)
treef141323e13347655a21bcd6cecbba6499d44ce05
parent21208ae5a21fd5f337e987cde11374eaf2fe70b4 (diff)
[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: Bart Van Assche <bvanassche@acm.org> Cc: <stable@kernel.org> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
-rw-r--r--drivers/scsi/hosts.c9
-rw-r--r--drivers/scsi/scsi_lib.c9
2 files changed, 15 insertions, 3 deletions
diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
index 4f7a5829ea4c..351dc0b86fab 100644
--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -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);
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index fc3f168decb4..b4d43ae76132 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -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);
}