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authorTejun Heo <tj@kernel.org>2010-09-03 11:56:16 +0200
committerJens Axboe <jaxboe@fusionio.com>2010-09-10 12:35:36 +0200
commitdd831006d5be7f74c3fe7aef82380c51c3637960 (patch)
tree30a86749f0c4f7980b2982dbde8bbcfff37b08f9 /block/blk-barrier.c
parent9cbbdca44ae1a6f512ea1e2be11ced8bbb9d430a (diff)
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block: misc cleanups in barrier code
Make the following cleanups in preparation of barrier/flush update. * blk_do_ordered() declaration is moved from include/linux/blkdev.h to block/blk.h. * blk_do_ordered() now returns pointer to struct request, with %NULL meaning "try the next request" and ERR_PTR(-EAGAIN) "try again later". The third case will be dropped with further changes. * In the initialization of proxy barrier request, data direction is already set by init_request_from_bio(). Drop unnecessary explicit REQ_WRITE setting and move init_request_from_bio() above REQ_FUA flag setting. * add_request() is collapsed into __make_request(). These changes don't make any functional difference. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Diffstat (limited to 'block/blk-barrier.c')
-rw-r--r--block/blk-barrier.c32
1 files changed, 14 insertions, 18 deletions
diff --git a/block/blk-barrier.c b/block/blk-barrier.c
index ed0aba5..f1be85b 100644
--- a/block/blk-barrier.c
+++ b/block/blk-barrier.c
@@ -110,9 +110,9 @@ static void queue_flush(struct request_queue *q, unsigned which)
elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
}
-static inline bool start_ordered(struct request_queue *q, struct request **rqp)
+static inline struct request *start_ordered(struct request_queue *q,
+ struct request *rq)
{
- struct request *rq = *rqp;
unsigned skip = 0;
q->orderr = 0;
@@ -149,11 +149,9 @@ static inline bool start_ordered(struct request_queue *q, struct request **rqp)
/* initialize proxy request and queue it */
blk_rq_init(q, rq);
- if (bio_data_dir(q->orig_bar_rq->bio) == WRITE)
- rq->cmd_flags |= REQ_WRITE;
+ init_request_from_bio(rq, q->orig_bar_rq->bio);
if (q->ordered & QUEUE_ORDERED_DO_FUA)
rq->cmd_flags |= REQ_FUA;
- init_request_from_bio(rq, q->orig_bar_rq->bio);
rq->end_io = bar_end_io;
elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
@@ -171,27 +169,26 @@ static inline bool start_ordered(struct request_queue *q, struct request **rqp)
else
skip |= QUEUE_ORDSEQ_DRAIN;
- *rqp = rq;
-
/*
* Complete skipped sequences. If whole sequence is complete,
- * return false to tell elevator that this request is gone.
+ * return %NULL to tell elevator that this request is gone.
*/
- return !blk_ordered_complete_seq(q, skip, 0);
+ if (blk_ordered_complete_seq(q, skip, 0))
+ rq = NULL;
+ return rq;
}
-bool blk_do_ordered(struct request_queue *q, struct request **rqp)
+struct request *blk_do_ordered(struct request_queue *q, struct request *rq)
{
- struct request *rq = *rqp;
const int is_barrier = rq->cmd_type == REQ_TYPE_FS &&
(rq->cmd_flags & REQ_HARDBARRIER);
if (!q->ordseq) {
if (!is_barrier)
- return true;
+ return rq;
if (q->next_ordered != QUEUE_ORDERED_NONE)
- return start_ordered(q, rqp);
+ return start_ordered(q, rq);
else {
/*
* Queue ordering not supported. Terminate
@@ -199,8 +196,7 @@ bool blk_do_ordered(struct request_queue *q, struct request **rqp)
*/
blk_dequeue_request(rq);
__blk_end_request_all(rq, -EOPNOTSUPP);
- *rqp = NULL;
- return false;
+ return NULL;
}
}
@@ -211,14 +207,14 @@ bool blk_do_ordered(struct request_queue *q, struct request **rqp)
/* Special requests are not subject to ordering rules. */
if (rq->cmd_type != REQ_TYPE_FS &&
rq != &q->pre_flush_rq && rq != &q->post_flush_rq)
- return true;
+ return rq;
/* Ordered by draining. Wait for turn. */
WARN_ON(blk_ordered_req_seq(rq) < blk_ordered_cur_seq(q));
if (blk_ordered_req_seq(rq) > blk_ordered_cur_seq(q))
- *rqp = NULL;
+ rq = ERR_PTR(-EAGAIN);
- return true;
+ return rq;
}
static void bio_end_empty_barrier(struct bio *bio, int err)