[PATCH RFC v2 7/8] dm-io: Warn on creating multiple atomic write bios for a region

From: John Garry
Date: Thu Jan 16 2025 - 12:08:15 EST


A region should just be for a single atomic write, so warn when we are
creating many. This should not occur if request queue limits are properly
configured.

Signed-off-by: John Garry <john.g.garry@xxxxxxxxxx>
---
drivers/md/dm-io.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c
index d7a8e2f40db3..c37668790577 100644
--- a/drivers/md/dm-io.c
+++ b/drivers/md/dm-io.c
@@ -379,6 +379,7 @@ static void do_region(const blk_opf_t opf, unsigned int region,

atomic_inc(&io->count);
submit_bio(bio);
+ WARN_ON_ONCE(opf & REQ_ATOMIC && remaining);
} while (remaining);
}

--
2.31.1