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From: Geliang Tang <geliangtang@163.com>
To: Jens Axboe <axboe@kernel.dk>
Cc: Geliang Tang <geliangtang@163.com>,
	linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] blk-throttle: use list_first_entry_or_null()
Date: Wed, 18 Nov 2015 21:07:31 +0800	[thread overview]
Message-ID: <8e96d9ad3e820a9ac346c0d2924507e9d34465b1.1447851969.git.geliangtang@163.com> (raw)

Simplify the code with list_first_entry_or_null().

Signed-off-by: Geliang Tang <geliangtang@163.com>
---
 block/blk-throttle.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 2149a1d..db2dbf1 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -263,10 +263,11 @@ static void throtl_qnode_add_bio(struct bio *bio, struct throtl_qnode *qn,
  */
 static struct bio *throtl_peek_queued(struct list_head *queued)
 {
-	struct throtl_qnode *qn = list_first_entry(queued, struct throtl_qnode, node);
+	struct throtl_qnode *qn;
 	struct bio *bio;
 
-	if (list_empty(queued))
+	qn = list_first_entry_or_null(queued, struct throtl_qnode, node);
+	if (!qn)
 		return NULL;
 
 	bio = bio_list_peek(&qn->bios);
@@ -291,10 +292,11 @@ static struct bio *throtl_peek_queued(struct list_head *queued)
 static struct bio *throtl_pop_queued(struct list_head *queued,
 				     struct throtl_grp **tg_to_put)
 {
-	struct throtl_qnode *qn = list_first_entry(queued, struct throtl_qnode, node);
+	struct throtl_qnode *qn;
 	struct bio *bio;
 
-	if (list_empty(queued))
+	qn = list_first_entry_or_null(queued, struct throtl_qnode, node);
+	if (!qn)
 		return NULL;
 
 	bio = bio_list_pop(&qn->bios);
-- 
2.5.0



                 reply	other threads:[~2015-11-18 13:08 UTC|newest]

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