From 797e7dbbee0a91fa1349192f18ad5c454997d876 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 6 Jan 2006 09:51:03 +0100 Subject: [PATCH] [BLOCK] reimplement handling of barrier request Reimplement handling of barrier requests. * Flexible handling to deal with various capabilities of target devices. * Retry support for falling back. * Tagged queues which don't support ordered tag can do ordered. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- block/elevator.c | 84 +++++--- block/ll_rw_blk.c | 408 ++++++++++++++++++++++++--------------- include/linux/blkdev.h | 82 +++++--- include/linux/elevator.h | 1 + 4 files changed, 371 insertions(+), 204 deletions(-) diff --git a/block/elevator.c b/block/elevator.c index 85a11cee7d1c..39dcccc82ada 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -304,15 +304,7 @@ void elv_requeue_request(request_queue_t *q, struct request *rq) rq->flags &= ~REQ_STARTED; - /* - * if this is the flush, requeue the original instead and drop the flush - */ - if (rq->flags & REQ_BAR_FLUSH) { - clear_bit(QUEUE_FLAG_FLUSH, &q->queue_flags); - rq = rq->end_io_data; - } - - __elv_add_request(q, rq, ELEVATOR_INSERT_FRONT, 0); + __elv_add_request(q, rq, ELEVATOR_INSERT_REQUEUE, 0); } static void elv_drain_elevator(request_queue_t *q) @@ -332,7 +324,18 @@ static void elv_drain_elevator(request_queue_t *q) void __elv_add_request(request_queue_t *q, struct request *rq, int where, int plug) { + struct list_head *pos; + unsigned ordseq; + + if (q->ordcolor) + rq->flags |= REQ_ORDERED_COLOR; + if (rq->flags & (REQ_SOFTBARRIER | REQ_HARDBARRIER)) { + /* + * toggle ordered color + */ + q->ordcolor ^= 1; + /* * barriers implicitly indicate back insertion */ @@ -393,6 +396,30 @@ void __elv_add_request(request_queue_t *q, struct request *rq, int where, q->elevator->ops->elevator_add_req_fn(q, rq); break; + case ELEVATOR_INSERT_REQUEUE: + /* + * If ordered flush isn't in progress, we do front + * insertion; otherwise, requests should be requeued + * in ordseq order. + */ + rq->flags |= REQ_SOFTBARRIER; + + if (q->ordseq == 0) { + list_add(&rq->queuelist, &q->queue_head); + break; + } + + ordseq = blk_ordered_req_seq(rq); + + list_for_each(pos, &q->queue_head) { + struct request *pos_rq = list_entry_rq(pos); + if (ordseq <= blk_ordered_req_seq(pos_rq)) + break; + } + + list_add_tail(&rq->queuelist, pos); + break; + default: printk(KERN_ERR "%s: bad insertion point %d\n", __FUNCTION__, where); @@ -422,25 +449,16 @@ static inline struct request *__elv_next_request(request_queue_t *q) { struct request *rq; - if (unlikely(list_empty(&q->queue_head) && - !q->elevator->ops->elevator_dispatch_fn(q, 0))) - return NULL; + while (1) { + while (!list_empty(&q->queue_head)) { + rq = list_entry_rq(q->queue_head.next); + if (blk_do_ordered(q, &rq)) + return rq; + } - rq = list_entry_rq(q->queue_head.next); - - /* - * if this is a barrier write and the device has to issue a - * flush sequence to support it, check how far we are - */ - if (blk_fs_request(rq) && blk_barrier_rq(rq)) { - BUG_ON(q->ordered == QUEUE_ORDERED_NONE); - - if (q->ordered == QUEUE_ORDERED_FLUSH && - !blk_barrier_preflush(rq)) - rq = blk_start_pre_flush(q, rq); + if (!q->elevator->ops->elevator_dispatch_fn(q, 0)) + return NULL; } - - return rq; } struct request *elv_next_request(request_queue_t *q) @@ -593,7 +611,21 @@ void elv_completed_request(request_queue_t *q, struct request *rq) * request is released from the driver, io must be done */ if (blk_account_rq(rq)) { + struct request *first_rq = list_entry_rq(q->queue_head.next); + q->in_flight--; + + /* + * Check if the queue is waiting for fs requests to be + * drained for flush sequence. + */ + if (q->ordseq && q->in_flight == 0 && + blk_ordered_cur_seq(q) == QUEUE_ORDSEQ_DRAIN && + blk_ordered_req_seq(first_rq) > QUEUE_ORDSEQ_DRAIN) { + blk_ordered_complete_seq(q, QUEUE_ORDSEQ_DRAIN, 0); + q->request_fn(q); + } + if (blk_sorted_rq(rq) && e->ops->elevator_completed_req_fn) e->ops->elevator_completed_req_fn(q, rq); } diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c index 65c4efc02adf..91d3b4828c49 100644 --- a/block/ll_rw_blk.c +++ b/block/ll_rw_blk.c @@ -290,8 +290,8 @@ static inline void rq_init(request_queue_t *q, struct request *rq) /** * blk_queue_ordered - does this queue support ordered writes - * @q: the request queue - * @flag: see below + * @q: the request queue + * @ordered: one of QUEUE_ORDERED_* * * Description: * For journalled file systems, doing ordered writes on a commit @@ -300,28 +300,30 @@ static inline void rq_init(request_queue_t *q, struct request *rq) * feature should call this function and indicate so. * **/ -void blk_queue_ordered(request_queue_t *q, int flag) +int blk_queue_ordered(request_queue_t *q, unsigned ordered, + prepare_flush_fn *prepare_flush_fn) { - switch (flag) { - case QUEUE_ORDERED_NONE: - if (q->flush_rq) - kmem_cache_free(request_cachep, q->flush_rq); - q->flush_rq = NULL; - q->ordered = flag; - break; - case QUEUE_ORDERED_TAG: - q->ordered = flag; - break; - case QUEUE_ORDERED_FLUSH: - q->ordered = flag; - if (!q->flush_rq) - q->flush_rq = kmem_cache_alloc(request_cachep, - GFP_KERNEL); - break; - default: - printk("blk_queue_ordered: bad value %d\n", flag); - break; + if (ordered & (QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH) && + prepare_flush_fn == NULL) { + printk(KERN_ERR "blk_queue_ordered: prepare_flush_fn required\n"); + return -EINVAL; } + + if (ordered != QUEUE_ORDERED_NONE && + ordered != QUEUE_ORDERED_DRAIN && + ordered != QUEUE_ORDERED_DRAIN_FLUSH && + ordered != QUEUE_ORDERED_DRAIN_FUA && + ordered != QUEUE_ORDERED_TAG && + ordered != QUEUE_ORDERED_TAG_FLUSH && + ordered != QUEUE_ORDERED_TAG_FUA) { + printk(KERN_ERR "blk_queue_ordered: bad value %d\n", ordered); + return -EINVAL; + } + + q->next_ordered = ordered; + q->prepare_flush_fn = prepare_flush_fn; + + return 0; } EXPORT_SYMBOL(blk_queue_ordered); @@ -346,167 +348,265 @@ EXPORT_SYMBOL(blk_queue_issue_flush_fn); /* * Cache flushing for ordered writes handling */ -static void blk_pre_flush_end_io(struct request *flush_rq, int error) +inline unsigned blk_ordered_cur_seq(request_queue_t *q) +{ + if (!q->ordseq) + return 0; + return 1 << ffz(q->ordseq); +} + +unsigned blk_ordered_req_seq(struct request *rq) { - struct request *rq = flush_rq->end_io_data; request_queue_t *q = rq->q; - elv_completed_request(q, flush_rq); + BUG_ON(q->ordseq == 0); - rq->flags |= REQ_BAR_PREFLUSH; + if (rq == &q->pre_flush_rq) + return QUEUE_ORDSEQ_PREFLUSH; + if (rq == &q->bar_rq) + return QUEUE_ORDSEQ_BAR; + if (rq == &q->post_flush_rq) + return QUEUE_ORDSEQ_POSTFLUSH; - if (!flush_rq->errors) - elv_requeue_request(q, rq); - else { - q->end_flush_fn(q, flush_rq); - clear_bit(QUEUE_FLAG_FLUSH, &q->queue_flags); - q->request_fn(q); - } + if ((rq->flags & REQ_ORDERED_COLOR) == + (q->orig_bar_rq->flags & REQ_ORDERED_COLOR)) + return QUEUE_ORDSEQ_DRAIN; + else + return QUEUE_ORDSEQ_DONE; } -static void blk_post_flush_end_io(struct request *flush_rq, int error) +void blk_ordered_complete_seq(request_queue_t *q, unsigned seq, int error) { - struct request *rq = flush_rq->end_io_data; - request_queue_t *q = rq->q; + struct request *rq; + int uptodate; - elv_completed_request(q, flush_rq); + if (error && !q->orderr) + q->orderr = error; - rq->flags |= REQ_BAR_POSTFLUSH; + BUG_ON(q->ordseq & seq); + q->ordseq |= seq; - q->end_flush_fn(q, flush_rq); - clear_bit(QUEUE_FLAG_FLUSH, &q->queue_flags); - q->request_fn(q); -} - -struct request *blk_start_pre_flush(request_queue_t *q, struct request *rq) -{ - struct request *flush_rq = q->flush_rq; - - BUG_ON(!blk_barrier_rq(rq)); - - if (test_and_set_bit(QUEUE_FLAG_FLUSH, &q->queue_flags)) - return NULL; - - rq_init(q, flush_rq); - flush_rq->elevator_private = NULL; - flush_rq->flags = REQ_BAR_FLUSH; - flush_rq->rq_disk = rq->rq_disk; - flush_rq->rl = NULL; + if (blk_ordered_cur_seq(q) != QUEUE_ORDSEQ_DONE) + return; /* - * prepare_flush returns 0 if no flush is needed, just mark both - * pre and post flush as done in that case + * Okay, sequence complete. */ - if (!q->prepare_flush_fn(q, flush_rq)) { - rq->flags |= REQ_BAR_PREFLUSH | REQ_BAR_POSTFLUSH; - clear_bit(QUEUE_FLAG_FLUSH, &q->queue_flags); - return rq; + rq = q->orig_bar_rq; + uptodate = q->orderr ? q->orderr : 1; + + q->ordseq = 0; + + end_that_request_first(rq, uptodate, rq->hard_nr_sectors); + end_that_request_last(rq, uptodate); +} + +static void pre_flush_end_io(struct request *rq, int error) +{ + elv_completed_request(rq->q, rq); + blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_PREFLUSH, error); +} + +static void bar_end_io(struct request *rq, int error) +{ + elv_completed_request(rq->q, rq); + blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_BAR, error); +} + +static void post_flush_end_io(struct request *rq, int error) +{ + elv_completed_request(rq->q, rq); + blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_POSTFLUSH, error); +} + +static void queue_flush(request_queue_t *q, unsigned which) +{ + struct request *rq; + rq_end_io_fn *end_io; + + if (which == QUEUE_ORDERED_PREFLUSH) { + rq = &q->pre_flush_rq; + end_io = pre_flush_end_io; + } else { + rq = &q->post_flush_rq; + end_io = post_flush_end_io; } + rq_init(q, rq); + rq->flags = REQ_HARDBARRIER; + rq->elevator_private = NULL; + rq->rq_disk = q->bar_rq.rq_disk; + rq->rl = NULL; + rq->end_io = end_io; + q->prepare_flush_fn(q, rq); + + __elv_add_request(q, rq, ELEVATOR_INSERT_FRONT, 0); +} + +static inline struct request *start_ordered(request_queue_t *q, + struct request *rq) +{ + q->bi_size = 0; + q->orderr = 0; + q->ordered = q->next_ordered; + q->ordseq |= QUEUE_ORDSEQ_STARTED; + /* - * some drivers dequeue requests right away, some only after io - * completion. make sure the request is dequeued. + * Prep proxy barrier request. */ - if (!list_empty(&rq->queuelist)) - blkdev_dequeue_request(rq); + blkdev_dequeue_request(rq); + q->orig_bar_rq = rq; + rq = &q->bar_rq; + rq_init(q, rq); + rq->flags = bio_data_dir(q->orig_bar_rq->bio); + rq->flags |= q->ordered & QUEUE_ORDERED_FUA ? REQ_FUA : 0; + rq->elevator_private = NULL; + rq->rl = NULL; + init_request_from_bio(rq, q->orig_bar_rq->bio); + rq->end_io = bar_end_io; - flush_rq->end_io_data = rq; - flush_rq->end_io = blk_pre_flush_end_io; + /* + * Queue ordered sequence. As we stack them at the head, we + * need to queue in reverse order. Note that we rely on that + * no fs request uses ELEVATOR_INSERT_FRONT and thus no fs + * request gets inbetween ordered sequence. + */ + if (q->ordered & QUEUE_ORDERED_POSTFLUSH) + queue_flush(q, QUEUE_ORDERED_POSTFLUSH); + else + q->ordseq |= QUEUE_ORDSEQ_POSTFLUSH; - __elv_add_request(q, flush_rq, ELEVATOR_INSERT_FRONT, 0); - return flush_rq; + __elv_add_request(q, rq, ELEVATOR_INSERT_FRONT, 0); + + if (q->ordered & QUEUE_ORDERED_PREFLUSH) { + queue_flush(q, QUEUE_ORDERED_PREFLUSH); + rq = &q->pre_flush_rq; + } else + q->ordseq |= QUEUE_ORDSEQ_PREFLUSH; + + if ((q->ordered & QUEUE_ORDERED_TAG) || q->in_flight == 0) + q->ordseq |= QUEUE_ORDSEQ_DRAIN; + else + rq = NULL; + + return rq; } -static void blk_start_post_flush(request_queue_t *q, struct request *rq) +int blk_do_ordered(request_queue_t *q, struct request **rqp) { - struct request *flush_rq = q->flush_rq; + struct request *rq = *rqp, *allowed_rq; + int is_barrier = blk_fs_request(rq) && blk_barrier_rq(rq); - BUG_ON(!blk_barrier_rq(rq)); + if (!q->ordseq) { + if (!is_barrier) + return 1; - rq_init(q, flush_rq); - flush_rq->elevator_private = NULL; - flush_rq->flags = REQ_BAR_FLUSH; - flush_rq->rq_disk = rq->rq_disk; - flush_rq->rl = NULL; - - if (q->prepare_flush_fn(q, flush_rq)) { - flush_rq->end_io_data = rq; - flush_rq->end_io = blk_post_flush_end_io; - - __elv_add_request(q, flush_rq, ELEVATOR_INSERT_FRONT, 0); - q->request_fn(q); + if (q->next_ordered != QUEUE_ORDERED_NONE) { + *rqp = start_ordered(q, rq); + return 1; + } else { + /* + * This can happen when the queue switches to + * ORDERED_NONE while this request is on it. + */ + blkdev_dequeue_request(rq); + end_that_request_first(rq, -EOPNOTSUPP, + rq->hard_nr_sectors); + end_that_request_last(rq, -EOPNOTSUPP); + *rqp = NULL; + return 0; + } } -} -static inline int blk_check_end_barrier(request_queue_t *q, struct request *rq, - int sectors) -{ - if (sectors > rq->nr_sectors) - sectors = rq->nr_sectors; - - rq->nr_sectors -= sectors; - return rq->nr_sectors; -} - -static int __blk_complete_barrier_rq(request_queue_t *q, struct request *rq, - int sectors, int queue_locked) -{ - if (q->ordered != QUEUE_ORDERED_FLUSH) - return 0; - if (!blk_fs_request(rq) || !blk_barrier_rq(rq)) - return 0; - if (blk_barrier_postflush(rq)) - return 0; - - if (!blk_check_end_barrier(q, rq, sectors)) { - unsigned long flags = 0; - - if (!queue_locked) - spin_lock_irqsave(q->queue_lock, flags); - - blk_start_post_flush(q, rq); - - if (!queue_locked) - spin_unlock_irqrestore(q->queue_lock, flags); + if (q->ordered & QUEUE_ORDERED_TAG) { + if (is_barrier && rq != &q->bar_rq) + *rqp = NULL; + return 1; } + switch (blk_ordered_cur_seq(q)) { + case QUEUE_ORDSEQ_PREFLUSH: + allowed_rq = &q->pre_flush_rq; + break; + case QUEUE_ORDSEQ_BAR: + allowed_rq = &q->bar_rq; + break; + case QUEUE_ORDSEQ_POSTFLUSH: + allowed_rq = &q->post_flush_rq; + break; + default: + allowed_rq = NULL; + break; + } + + if (rq != allowed_rq && + (blk_fs_request(rq) || rq == &q->pre_flush_rq || + rq == &q->post_flush_rq)) + *rqp = NULL; + return 1; } -/** - * blk_complete_barrier_rq - complete possible barrier request - * @q: the request queue for the device - * @rq: the request - * @sectors: number of sectors to complete - * - * Description: - * Used in driver end_io handling to determine whether to postpone - * completion of a barrier request until a post flush has been done. This - * is the unlocked variant, used if the caller doesn't already hold the - * queue lock. - **/ -int blk_complete_barrier_rq(request_queue_t *q, struct request *rq, int sectors) +static int flush_dry_bio_endio(struct bio *bio, unsigned int bytes, int error) { - return __blk_complete_barrier_rq(q, rq, sectors, 0); -} -EXPORT_SYMBOL(blk_complete_barrier_rq); + request_queue_t *q = bio->bi_private; + struct bio_vec *bvec; + int i; -/** - * blk_complete_barrier_rq_locked - complete possible barrier request - * @q: the request queue for the device - * @rq: the request - * @sectors: number of sectors to complete - * - * Description: - * See blk_complete_barrier_rq(). This variant must be used if the caller - * holds the queue lock. - **/ -int blk_complete_barrier_rq_locked(request_queue_t *q, struct request *rq, - int sectors) -{ - return __blk_complete_barrier_rq(q, rq, sectors, 1); + /* + * This is dry run, restore bio_sector and size. We'll finish + * this request again with the original bi_end_io after an + * error occurs or post flush is complete. + */ + q->bi_size += bytes; + + if (bio->bi_size) + return 1; + + /* Rewind bvec's */ + bio->bi_idx = 0; + bio_for_each_segment(bvec, bio, i) { + bvec->bv_len += bvec->bv_offset; + bvec->bv_offset = 0; + } + + /* Reset bio */ + set_bit(BIO_UPTODATE, &bio->bi_flags); + bio->bi_size = q->bi_size; + bio->bi_sector -= (q->bi_size >> 9); + q->bi_size = 0; + + return 0; +} + +static inline int ordered_bio_endio(struct request *rq, struct bio *bio, + unsigned int nbytes, int error) +{ + request_queue_t *q = rq->q; + bio_end_io_t *endio; + void *private; + + if (&q->bar_rq != rq) + return 0; + + /* + * Okay, this is the barrier request in progress, dry finish it. + */ + if (error && !q->orderr) + q->orderr = error; + + endio = bio->bi_end_io; + private = bio->bi_private; + bio->bi_end_io = flush_dry_bio_endio; + bio->bi_private = q; + + bio_endio(bio, nbytes, error); + + bio->bi_end_io = endio; + bio->bi_private = private; + + return 1; } -EXPORT_SYMBOL(blk_complete_barrier_rq_locked); /** * blk_queue_bounce_limit - set bounce buffer limit for queue @@ -1047,6 +1147,7 @@ static const char * const rq_flags[] = { "REQ_SORTED", "REQ_SOFTBARRIER", "REQ_HARDBARRIER", + "REQ_FUA", "REQ_CMD", "REQ_NOMERGE", "REQ_STARTED", @@ -1066,6 +1167,7 @@ static const char * const rq_flags[] = { "REQ_PM_SUSPEND", "REQ_PM_RESUME", "REQ_PM_SHUTDOWN", + "REQ_ORDERED_COLOR", }; void blk_dump_rq_flags(struct request *rq, char *msg) @@ -1643,8 +1745,6 @@ void blk_cleanup_queue(request_queue_t * q) if (q->queue_tags) __blk_queue_free_tags(q); - blk_queue_ordered(q, QUEUE_ORDERED_NONE); - kmem_cache_free(requestq_cachep, q); } @@ -2714,7 +2814,7 @@ static int __make_request(request_queue_t *q, struct bio *bio) spin_lock_prefetch(q->queue_lock); barrier = bio_barrier(bio); - if (unlikely(barrier) && (q->ordered == QUEUE_ORDERED_NONE)) { + if (unlikely(barrier) && (q->next_ordered == QUEUE_ORDERED_NONE)) { err = -EOPNOTSUPP; goto end_io; } @@ -3075,7 +3175,8 @@ static int __end_that_request_first(struct request *req, int uptodate, if (nr_bytes >= bio->bi_size) { req->bio = bio->bi_next; nbytes = bio->bi_size; - bio_endio(bio, nbytes, error); + if (!ordered_bio_endio(req, bio, nbytes, error)) + bio_endio(bio, nbytes, error); next_idx = 0; bio_nbytes = 0; } else { @@ -3130,7 +3231,8 @@ static int __end_that_request_first(struct request *req, int uptodate, * if the request wasn't completed, update state */ if (bio_nbytes) { - bio_endio(bio, bio_nbytes, error); + if (!ordered_bio_endio(req, bio, bio_nbytes, error)) + bio_endio(bio, bio_nbytes, error); bio->bi_idx += next_idx; bio_iovec(bio)->bv_offset += nr_bytes; bio_iovec(bio)->bv_len -= nr_bytes; diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index a0ce8c585165..15db0f112d0a 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -207,6 +207,7 @@ enum rq_flag_bits { __REQ_SORTED, /* elevator knows about this request */ __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */ __REQ_HARDBARRIER, /* may not be passed by drive either */ + __REQ_FUA, /* forced unit access */ __REQ_CMD, /* is a regular fs rw request */ __REQ_NOMERGE, /* don't touch this for merging */ __REQ_STARTED, /* drive already may have started this one */ @@ -230,9 +231,7 @@ enum rq_flag_bits { __REQ_PM_SUSPEND, /* suspend request */ __REQ_PM_RESUME, /* resume request */ __REQ_PM_SHUTDOWN, /* shutdown request */ - __REQ_BAR_PREFLUSH, /* barrier pre-flush done */ - __REQ_BAR_POSTFLUSH, /* barrier post-flush */ - __REQ_BAR_FLUSH, /* rq is the flush request */ + __REQ_ORDERED_COLOR, /* is before or after barrier */ __REQ_NR_BITS, /* stops here */ }; @@ -241,6 +240,7 @@ enum rq_flag_bits { #define REQ_SORTED (1 << __REQ_SORTED) #define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER) #define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER) +#define REQ_FUA (1 << __REQ_FUA) #define REQ_CMD (1 << __REQ_CMD) #define REQ_NOMERGE (1 << __REQ_NOMERGE) #define REQ_STARTED (1 << __REQ_STARTED) @@ -260,9 +260,7 @@ enum rq_flag_bits { #define REQ_PM_SUSPEND (1 << __REQ_PM_SUSPEND) #define REQ_PM_RESUME (1 << __REQ_PM_RESUME) #define REQ_PM_SHUTDOWN (1 << __REQ_PM_SHUTDOWN) -#define REQ_BAR_PREFLUSH (1 << __REQ_BAR_PREFLUSH) -#define REQ_BAR_POSTFLUSH (1 << __REQ_BAR_POSTFLUSH) -#define REQ_BAR_FLUSH (1 << __REQ_BAR_FLUSH) +#define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR) /* * State information carried for REQ_PM_SUSPEND and REQ_PM_RESUME @@ -292,8 +290,7 @@ struct bio_vec; typedef int (merge_bvec_fn) (request_queue_t *, struct bio *, struct bio_vec *); typedef void (activity_fn) (void *data, int rw); typedef int (issue_flush_fn) (request_queue_t *, struct gendisk *, sector_t *); -typedef int (prepare_flush_fn) (request_queue_t *, struct request *); -typedef void (end_flush_fn) (request_queue_t *, struct request *); +typedef void (prepare_flush_fn) (request_queue_t *, struct request *); enum blk_queue_state { Queue_down, @@ -335,7 +332,6 @@ struct request_queue activity_fn *activity_fn; issue_flush_fn *issue_flush_fn; prepare_flush_fn *prepare_flush_fn; - end_flush_fn *end_flush_fn; /* * Dispatch queue sorting @@ -420,14 +416,11 @@ struct request_queue /* * reserved for flush operations */ - struct request *flush_rq; - unsigned char ordered; -}; - -enum { - QUEUE_ORDERED_NONE, - QUEUE_ORDERED_TAG, - QUEUE_ORDERED_FLUSH, + unsigned int ordered, next_ordered, ordseq; + int orderr, ordcolor; + struct request pre_flush_rq, bar_rq, post_flush_rq; + struct request *orig_bar_rq; + unsigned int bi_size; }; #define RQ_INACTIVE (-1) @@ -445,12 +438,51 @@ enum { #define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */ #define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */ #define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */ -#define QUEUE_FLAG_FLUSH 9 /* doing barrier flush sequence */ + +enum { + /* + * Hardbarrier is supported with one of the following methods. + * + * NONE : hardbarrier unsupported + * DRAIN : ordering by draining is enough + * DRAIN_FLUSH : ordering by draining w/ pre and post flushes + * DRAIN_FUA : ordering by draining w/ pre flush and FUA write + * TAG : ordering by tag is enough + * TAG_FLUSH : ordering by tag w/ pre and post flushes + * TAG_FUA : ordering by tag w/ pre flush and FUA write + */ + QUEUE_ORDERED_NONE = 0x00, + QUEUE_ORDERED_DRAIN = 0x01, + QUEUE_ORDERED_TAG = 0x02, + + QUEUE_ORDERED_PREFLUSH = 0x10, + QUEUE_ORDERED_POSTFLUSH = 0x20, + QUEUE_ORDERED_FUA = 0x40, + + QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN | + QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH, + QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN | + QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA, + QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG | + QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH, + QUEUE_ORDERED_TAG_FUA = QUEUE_ORDERED_TAG | + QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA, + + /* + * Ordered operation sequence + */ + QUEUE_ORDSEQ_STARTED = 0x01, /* flushing in progress */ + QUEUE_ORDSEQ_DRAIN = 0x02, /* waiting for the queue to be drained */ + QUEUE_ORDSEQ_PREFLUSH = 0x04, /* pre-flushing in progress */ + QUEUE_ORDSEQ_BAR = 0x08, /* original barrier req in progress */ + QUEUE_ORDSEQ_POSTFLUSH = 0x10, /* post-flushing in progress */ + QUEUE_ORDSEQ_DONE = 0x20, +}; #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags) #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags) #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags) -#define blk_queue_flushing(q) test_bit(QUEUE_FLAG_FLUSH, &(q)->queue_flags) +#define blk_queue_flushing(q) ((q)->ordseq) #define blk_fs_request(rq) ((rq)->flags & REQ_CMD) #define blk_pc_request(rq) ((rq)->flags & REQ_BLOCK_PC) @@ -466,8 +498,7 @@ enum { #define blk_sorted_rq(rq) ((rq)->flags & REQ_SORTED) #define blk_barrier_rq(rq) ((rq)->flags & REQ_HARDBARRIER) -#define blk_barrier_preflush(rq) ((rq)->flags & REQ_BAR_PREFLUSH) -#define blk_barrier_postflush(rq) ((rq)->flags & REQ_BAR_POSTFLUSH) +#define blk_fua_rq(rq) ((rq)->flags & REQ_FUA) #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist) @@ -665,11 +696,12 @@ extern void blk_queue_prep_rq(request_queue_t *, prep_rq_fn *pfn); extern void blk_queue_merge_bvec(request_queue_t *, merge_bvec_fn *); extern void blk_queue_dma_alignment(request_queue_t *, int); extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); -extern void blk_queue_ordered(request_queue_t *, int); +extern int blk_queue_ordered(request_queue_t *, unsigned, prepare_flush_fn *); extern void blk_queue_issue_flush_fn(request_queue_t *, issue_flush_fn *); -extern struct request *blk_start_pre_flush(request_queue_t *,struct request *); -extern int blk_complete_barrier_rq(request_queue_t *, struct request *, int); -extern int blk_complete_barrier_rq_locked(request_queue_t *, struct request *, int); +extern int blk_do_ordered(request_queue_t *, struct request **); +extern unsigned blk_ordered_cur_seq(request_queue_t *); +extern unsigned blk_ordered_req_seq(struct request *); +extern void blk_ordered_complete_seq(request_queue_t *, unsigned, int); extern int blk_rq_map_sg(request_queue_t *, struct request *, struct scatterlist *); extern void blk_dump_rq_flags(struct request *, char *); diff --git a/include/linux/elevator.h b/include/linux/elevator.h index a74c27e460ba..fb80fa44c4dd 100644 --- a/include/linux/elevator.h +++ b/include/linux/elevator.h @@ -130,6 +130,7 @@ extern int elv_try_last_merge(request_queue_t *, struct bio *); #define ELEVATOR_INSERT_FRONT 1 #define ELEVATOR_INSERT_BACK 2 #define ELEVATOR_INSERT_SORT 3 +#define ELEVATOR_INSERT_REQUEUE 4 /* * return values from elevator_may_queue_fn