dm: fix comment in dm_process_bio()

Refer to the correct function (->submit_bio instead of ->queue_bio).
Also, add details about why using blk_queue_split() isn't needed for
dm_wq_work()'s call to dm_process_bio().

Fixes: c62b37d96b6eb ("block: move ->make_request_fn to struct block_device_operations")
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index d948cd5..6ed05ca 100644 (file)
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1744,9 +1744,11 @@ static blk_qc_t dm_process_bio(struct mapped_device *md,
        }
 
        /*
-        * If in ->queue_bio we need to use blk_queue_split(), otherwise
+        * If in ->submit_bio we need to use blk_queue_split(), otherwise
         * queue_limits for abnormal requests (e.g. discard, writesame, etc)
         * won't be imposed.
+        * If called from dm_wq_work() for deferred bio processing, bio
+        * was already handled by following code with previous ->submit_bio.
         */
        if (current->bio_list) {
                if (is_abnormal_io(bio))