From a492f075450f3ba87de36e5ffe92a9d0c7af9723 Mon Sep 17 00:00:00 2001 From: Joe Lawrence <joe.lawrence@stratus.com> Date: Thu, 28 Aug 2014 08:15:21 -0600 Subject: block,scsi: fixup blk_get_request dead queue scenarios The blk_get_request function may fail in low-memory conditions or during device removal (even if __GFP_WAIT is set). To distinguish between these errors, modify the blk_get_request call stack to return the appropriate ERR_PTR. Verify that all callers check the return status and consider IS_ERR instead of a simple NULL pointer check. For consistency, make a similar change to the blk_mq_alloc_request leg of blk_get_request. It may fail if the queue is dead, or the caller was unwilling to wait. Signed-off-by: Joe Lawrence <joe.lawrence@stratus.com> Acked-by: Jiri Kosina <jkosina@suse.cz> [for pktdvd] Acked-by: Boaz Harrosh <bharrosh@panasas.com> [for osd] Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com> --- drivers/scsi/scsi_error.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/scsi/scsi_error.c') diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c index 4c433bf47a06..a2c3d3d255a1 100644 --- a/drivers/scsi/scsi_error.c +++ b/drivers/scsi/scsi_error.c @@ -1960,7 +1960,7 @@ static void scsi_eh_lock_door(struct scsi_device *sdev) * request becomes available */ req = blk_get_request(sdev->request_queue, READ, GFP_KERNEL); - if (!req) + if (IS_ERR(req)) return; blk_rq_set_block_pc(req); -- cgit v1.2.3