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@xxxxxxx> Cc: James Bottomley <jbottomley@xxxxxxxxxxxxx> Cc: <stable@xxxxxxxxxx> --- drivers/scsi/hosts.c | 9 ++++++--- drivers/scsi/scsi_lib.c | 9 +++++++++ 2 files changed, 15 insertions(+), 3 deletions(-) diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c index 4f7a582..351dc0b 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 fc3f168..b4d43ae 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); } -- 1.7.3.4 -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
