From a492f075450f3ba87de36e5ffe92a9d0c7af9723 Mon Sep 17 00:00:00 2001 From: Joe Lawrence 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 Acked-by: Jiri Kosina [for pktdvd] Acked-by: Boaz Harrosh [for osd] Reviewed-by: Jeff Moyer Signed-off-by: Jens Axboe --- drivers/scsi/st.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/scsi/st.c') diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c index aff9689de0f7..59db5bfc11db 100644 --- a/drivers/scsi/st.c +++ b/drivers/scsi/st.c @@ -490,7 +490,7 @@ static int st_scsi_execute(struct st_request *SRpnt, const unsigned char *cmd, req = blk_get_request(SRpnt->stp->device->request_queue, write, GFP_KERNEL); - if (!req) + if (IS_ERR(req)) return DRIVER_ERROR << 24; blk_rq_set_block_pc(req); -- cgit