diff options
| -rw-r--r-- | block/blk-barrier.c | 45 | ||||
| -rw-r--r-- | block/elevator.c | 10 | ||||
| -rw-r--r-- | include/linux/blkdev.h | 4 |
3 files changed, 36 insertions, 23 deletions
diff --git a/block/blk-barrier.c b/block/blk-barrier.c index 1efabf829c5..b03d88013e1 100644 --- a/block/blk-barrier.c +++ b/block/blk-barrier.c @@ -88,7 +88,7 @@ unsigned blk_ordered_req_seq(struct request *rq) return QUEUE_ORDSEQ_DONE; } -void blk_ordered_complete_seq(struct request_queue *q, unsigned seq, int error) +bool blk_ordered_complete_seq(struct request_queue *q, unsigned seq, int error) { struct request *rq; @@ -99,7 +99,7 @@ void blk_ordered_complete_seq(struct request_queue *q, unsigned seq, int error) q->ordseq |= seq; if (blk_ordered_cur_seq(q) != QUEUE_ORDSEQ_DONE) - return; + return false; /* * Okay, sequence complete. @@ -109,6 +109,8 @@ void blk_ordered_complete_seq(struct request_queue *q, unsigned seq, int error) if (__blk_end_request(rq, q->orderr, blk_rq_bytes(rq))) BUG(); + + return true; } static void pre_flush_end_io(struct request *rq, int error) @@ -151,9 +153,11 @@ static void queue_flush(struct request_queue *q, unsigned which) elv_insert(q, rq, ELEVATOR_INSERT_FRONT); } -static inline struct request *start_ordered(struct request_queue *q, - struct request *rq) +static inline bool start_ordered(struct request_queue *q, struct request **rqp) { + struct request *rq = *rqp; + unsigned skip = 0; + q->orderr = 0; q->ordered = q->next_ordered; q->ordseq |= QUEUE_ORDSEQ_STARTED; @@ -177,7 +181,7 @@ static inline struct request *start_ordered(struct request_queue *q, queue_flush(q, QUEUE_ORDERED_DO_POSTFLUSH); rq = &q->post_flush_rq; } else - q->ordseq |= QUEUE_ORDSEQ_POSTFLUSH; + skip |= QUEUE_ORDSEQ_POSTFLUSH; if (q->ordered & QUEUE_ORDERED_DO_BAR) { rq = &q->bar_rq; @@ -193,35 +197,40 @@ static inline struct request *start_ordered(struct request_queue *q, elv_insert(q, rq, ELEVATOR_INSERT_FRONT); } else - q->ordseq |= QUEUE_ORDSEQ_BAR; + skip |= QUEUE_ORDSEQ_BAR; if (q->ordered & QUEUE_ORDERED_DO_PREFLUSH) { queue_flush(q, QUEUE_ORDERED_DO_PREFLUSH); rq = &q->pre_flush_rq; } else - q->ordseq |= QUEUE_ORDSEQ_PREFLUSH; + skip |= QUEUE_ORDSEQ_PREFLUSH; if ((q->ordered & QUEUE_ORDERED_BY_DRAIN) && q->in_flight) rq = NULL; else - q->ordseq |= QUEUE_ORDSEQ_DRAIN; + skip |= QUEUE_ORDSEQ_DRAIN; + + *rqp = rq; - return rq; + /* + * Complete skipped sequences. If whole sequence is complete, + * return false to tell elevator that this request is gone. + */ + return !blk_ordered_complete_seq(q, skip, 0); } -int blk_do_ordered(struct request_queue *q, struct request **rqp) +bool blk_do_ordered(struct request_queue *q, struct request **rqp) { struct request *rq = *rqp; const int is_barrier = blk_fs_request(rq) && blk_barrier_rq(rq); if (!q->ordseq) { if (!is_barrier) - return 1; + return true; - if (q->next_ordered != QUEUE_ORDERED_NONE) { - *rqp = start_ordered(q, rq); - return 1; - } else { + if (q->next_ordered != QUEUE_ORDERED_NONE) + return start_ordered(q, rqp); + else { /* * Queue ordering not supported. Terminate * with prejudice. @@ -231,7 +240,7 @@ int blk_do_ordered(struct request_queue *q, struct request **rqp) blk_rq_bytes(rq))) BUG(); *rqp = NULL; - return 0; + return false; } } @@ -242,7 +251,7 @@ int blk_do_ordered(struct request_queue *q, struct request **rqp) /* Special requests are not subject to ordering rules. */ if (!blk_fs_request(rq) && rq != &q->pre_flush_rq && rq != &q->post_flush_rq) - return 1; + return true; if (q->ordered & QUEUE_ORDERED_BY_TAG) { /* Ordered by tag. Blocking the next barrier is enough. */ @@ -255,7 +264,7 @@ int blk_do_ordered(struct request_queue *q, struct request **rqp) *rqp = NULL; } - return 1; + return true; } static void bio_end_empty_barrier(struct bio *bio, int err) diff --git a/block/elevator.c b/block/elevator.c index 86836dd179c..261ffaaf47b 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -944,10 +944,14 @@ void elv_completed_request(struct request_queue *q, struct request *rq) * drained for flush sequence. */ if (unlikely(q->ordseq)) { - struct request *first_rq = list_entry_rq(q->queue_head.next); - if (q->in_flight == 0 && + struct request *next = NULL; + + if (!list_empty(&q->queue_head)) + next = list_entry_rq(q->queue_head.next); + + if (!q->in_flight && blk_ordered_cur_seq(q) == QUEUE_ORDSEQ_DRAIN && - blk_ordered_req_seq(first_rq) > QUEUE_ORDSEQ_DRAIN) { + (!next || blk_ordered_req_seq(next) > QUEUE_ORDSEQ_DRAIN)) { blk_ordered_complete_seq(q, QUEUE_ORDSEQ_DRAIN, 0); blk_start_queueing(q); } diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index b044267009e..3c7078e0129 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -866,10 +866,10 @@ extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *); extern void blk_queue_rq_timeout(struct request_queue *, unsigned int); extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); extern int blk_queue_ordered(struct request_queue *, unsigned, prepare_flush_fn *); -extern int blk_do_ordered(struct request_queue *, struct request **); +extern bool blk_do_ordered(struct request_queue *, struct request **); extern unsigned blk_ordered_cur_seq(struct request_queue *); extern unsigned blk_ordered_req_seq(struct request *); -extern void blk_ordered_complete_seq(struct request_queue *, unsigned, int); +extern bool blk_ordered_complete_seq(struct request_queue *, unsigned, int); extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *); extern void blk_dump_rq_flags(struct request *, char *); |