block: document BLK_STS_AGAIN usage

BLK_STS_AGAIN should only be used if RQF_NOWAIT is set and the bio
would block. So we'd better document that to avoid accidental misuse.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220524055631.85480-2-hare@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Hannes Reinecke 2022-05-24 07:56:30 +02:00 committed by Jens Axboe
parent 403d50341c
commit 98d40e7665

View File

@ -105,6 +105,10 @@ typedef u16 blk_short_t;
/* hack for device mapper, don't use elsewhere: */
#define BLK_STS_DM_REQUEUE ((__force blk_status_t)11)
/*
* BLK_STS_AGAIN should only be returned if RQF_NOWAIT is set
* and the bio would block (cf bio_wouldblock_error())
*/
#define BLK_STS_AGAIN ((__force blk_status_t)12)
/*