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/cdrom/cdrom.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/cdrom') diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c index 898b84bba28a..5d28a45d2960 100644 --- a/drivers/cdrom/cdrom.c +++ b/drivers/cdrom/cdrom.c @@ -2180,8 +2180,8 @@ static int cdrom_read_cdda_bpc(struct cdrom_device_info *cdi, __u8 __user *ubuf, len = nr * CD_FRAMESIZE_RAW; rq = blk_get_request(q, READ, GFP_KERNEL); - if (!rq) { - ret = -ENOMEM; + if (IS_ERR(rq)) { + ret = PTR_ERR(rq); break; } blk_rq_set_block_pc(rq); -- cgit v1.2.3-59-g8ed1b