[PATCH v1 02/54] block: loop: comment on direct access to bvec table

From	Ming Lei <tom.leiming@gmail.com>
Newsgroups	linux.kernel
Subject	[PATCH v1 02/54] block: loop: comment on direct access to bvec table
Date	2016-12-27 17:10 +0100
Message-ID	<sT2u6-4eA-31@gated-at.bofh.it> (permalink)
References	<sT2u5-4eA-3@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
---
 drivers/block/loop.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index f347285c67ec..be1cc51815ac 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -485,6 +485,11 @@ static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd,
 	/* nomerge for loop request queue */
 	WARN_ON(cmd->rq->bio != cmd->rq->biotail);
 
+	/*
+	 * For multipage bvec support, it is safe to pass the bvec
+	 * table to iov iterator, because iov iter still uses bvec
+	 * iter helpers to travese bvec.
+	 */
 	bvec = __bvec_iter_bvec(bio->bi_io_vec, bio->bi_iter);
 	iov_iter_bvec(&iter, ITER_BVEC | rw, bvec,
 		      bio_segments(bio), blk_rq_bytes(cmd->rq));
-- 
2.7.4

Back to linux.kernel | Previous | Next | Find similar | Unroll thread

Thread

[PATCH v1 02/54] block: loop: comment on direct access to bvec table Ming Lei <tom.leiming@gmail.com> - 2016-12-27 17:10 +0100

csiph-web