From: Hannes Reinecke <hare@suse.de>
Date: Tue, 24 May 2022 05:56:30 +0000 (+0200)
Subject: block: document BLK_STS_AGAIN usage
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=98d40e76652e9aeb3aec4065f600d633ed335e94;p=people%2Fms%2Flinux.git

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>
---

diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 40e815400611..8b38367d1bc7 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -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)
 
 /*