[dm-devel] [PATCH v2] dm io: Drop the obsolete and incorrect doc for dm_io()

[Barry Song]

Commit 7eaceaccab5f ("block: remove per-queue plugging") dropped
unplug_delay and blk_unplug(). Plus, the current kernel has no
fundamental difference between sync_io() and async_io() except
sync_io() uses sync_io_complete() as the notify.fn and explicitly
calls wait_for_completion_io() to sync. The comment isn't valid
any more.

Cc: Jens Axboe <axboe at kernel.dk>
Reviewed-by: Christoph Hellwig <hch at lst.de>
Signed-off-by: Barry Song <song.bao.hua at hisilicon.com>
---
 -v2: refine commit log;
      add revewed-by of Christoph, thanks!

 drivers/md/dm-io.c | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c
index 2d3cda0acacb..7dba193de28b 100644
--- a/drivers/md/dm-io.c
+++ b/drivers/md/dm-io.c
@@ -528,11 +528,6 @@ static int dp_init(struct dm_io_request *io_req, struct dpages *dp,
 
 /*
  * New collapsed (a)synchronous interface.
- *
- * If the IO is asynchronous (i.e. it has notify.fn), you must either unplug
- * the queue with blk_unplug() some time later or set REQ_SYNC in
- * io_req->bi_opf. If you fail to do one of these, the IO will be submitted to
- * the disk after q->unplug_delay, which defaults to 3ms in blk-settings.c.
  */
 int dm_io(struct dm_io_request *io_req, unsigned num_regions,
 	  struct dm_io_region *where, unsigned long *sync_error_bits)
-- 
2.25.1