From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261466AbVFEGHW (ORCPT ); Sun, 5 Jun 2005 02:07:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261481AbVFEGHP (ORCPT ); Sun, 5 Jun 2005 02:07:15 -0400 Received: from wproxy.gmail.com ([64.233.184.199]:32244 "EHLO wproxy.gmail.com") by vger.kernel.org with ESMTP id S261466AbVFEF5f (ORCPT ); Sun, 5 Jun 2005 01:57:35 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:from:to:cc:user-agent:content-type:references:in-reply-to:subject:message-id:date; b=fnbc3gOzNfftFzAMN54JBpBuW9CpqTX/nV80peBkNcLlGB9YaEDHWq71iO2noIEj1ca6vQq9H0iU+3aKsjdjdhkiHksLNZ4jcQ2XVHOYYeuG6po4mgFtnRbKYHJcjgvQ7T8icJU76ljX4KgKbBhUoCJPKRZuCD3vOHXHaPsMocg= From: Tejun Heo To: axboe@suse.de, James.Bottomley@steeleye.com, bzolnier@gmail.com, jgarzik@pobox.com Cc: linux-kernel@vger.kernel.org User-Agent: lksp 0.3 Content-Type: text/plain; charset=US-ASCII References: <20050605055337.6301E65A@htj.dyndns.org> In-Reply-To: <20050605055337.6301E65A@htj.dyndns.org> Subject: Re: [PATCH Linux 2.6.12-rc5-mm2 05/09] blk: reimplement handling of barrier request Message-ID: <20050605055337.C21DB928@htj.dyndns.org> Date: Sun, 5 Jun 2005 14:57:29 +0900 (KST) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org 05_blk_ordered_reimpl.patch 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 drivers/block/elevator.c | 79 ++++--- drivers/block/ll_rw_blk.c | 491 ++++++++++++++++++++++++++++++++-------------- include/linux/blkdev.h | 93 ++++++-- 3 files changed, 469 insertions(+), 194 deletions(-) Index: blk-fixes/drivers/block/elevator.c =================================================================== --- blk-fixes.orig/drivers/block/elevator.c 2005-06-05 14:53:32.000000000 +0900 +++ blk-fixes/drivers/block/elevator.c 2005-06-05 14:53:34.000000000 +0900 @@ -37,9 +37,38 @@ #include +/* + * XXX HACK XXX Before entering elevator callbacks, we temporailiy + * turn off REQ_CMD of proxy barrier request so that elevators don't + * try to account it as a normal one. This ugliness can go away once + * generic dispatch queue is implemented. - tj + */ +#define bar_rq_hack_start(q) ((q)->bar_rq && ((q)->bar_rq->flags &= ~REQ_CMD)) +#define bar_rq_hack_end(q) ((q)->bar_rq && ((q)->bar_rq->flags |= REQ_CMD)) + static DEFINE_SPINLOCK(elv_list_lock); static LIST_HEAD(elv_list); +static inline void elv_inc_inflight(request_queue_t *q) +{ + q->in_flight++; +} + +static inline void elv_dec_inflight(request_queue_t *q) +{ + q->in_flight--; + + /* + * If the queue is waiting for all accounted requests to be + * drained to start flush sequence and we're the last one, + * kick the queue in the ass to start the flush sequence. + */ + if (q->in_flight == 0 && blk_ordered_cur_seq(q) == QUEUE_ORDSEQ_DRAIN) { + blk_ordered_complete_seq(q, QUEUE_ORDSEQ_DRAIN, 0); + q->request_fn(q); + } +} + /* * can we safely merge with this request? */ @@ -270,12 +299,15 @@ void elv_deactivate_request(request_queu * in_flight count again */ if (blk_account_rq(rq)) - q->in_flight--; + elv_dec_inflight(q); rq->flags &= ~REQ_STARTED; - if (e->ops->elevator_deactivate_req_fn) + if (e->ops->elevator_deactivate_req_fn) { + bar_rq_hack_start(q); e->ops->elevator_deactivate_req_fn(q, rq); + bar_rq_hack_end(q); + } } void elv_requeue_request(request_queue_t *q, struct request *rq) @@ -283,14 +315,6 @@ void elv_requeue_request(request_queue_t elv_deactivate_request(q, rq); /* - * 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; - } - - /* * the request is prepped and may have some resources allocated. * allowing unprepped requests to pass this one may cause resource * deadlock. turn on softbarrier. @@ -301,9 +325,11 @@ void elv_requeue_request(request_queue_t * if iosched has an explicit requeue hook, then use that. otherwise * just put the request at the front of the queue */ - if (q->elevator->ops->elevator_requeue_req_fn) + if (q->elevator->ops->elevator_requeue_req_fn) { + bar_rq_hack_start(q); q->elevator->ops->elevator_requeue_req_fn(q, rq); - else + bar_rq_hack_end(q); + } else __elv_add_request(q, rq, ELEVATOR_INSERT_FRONT, 0); } @@ -323,7 +349,9 @@ void __elv_add_request(request_queue_t * rq->q = q; if (!test_bit(QUEUE_FLAG_DRAIN, &q->queue_flags)) { + bar_rq_hack_start(q); q->elevator->ops->elevator_add_req_fn(q, rq, where); + bar_rq_hack_end(q); if (blk_queue_plugged(q)) { int nrq = q->rq.count[READ] + q->rq.count[WRITE] @@ -353,20 +381,10 @@ void elv_add_request(request_queue_t *q, static inline struct request *__elv_next_request(request_queue_t *q) { - struct request *rq = q->elevator->ops->elevator_next_req_fn(q); - - /* - * if this is a barrier write and the device has to issue a - * flush sequence to support it, check how far we are - */ - if (rq && 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); - } - + struct request *rq; + while ((rq = q->elevator->ops->elevator_next_req_fn(q))) + if (blk_do_ordered(q, &rq)) + break; return rq; } @@ -433,7 +451,7 @@ void elv_remove_request(request_queue_t * for request-request merges */ if (blk_account_rq(rq)) - q->in_flight++; + elv_inc_inflight(q); /* * the main clearing point for q->last_merge is on retrieval of @@ -445,8 +463,11 @@ void elv_remove_request(request_queue_t if (rq == q->last_merge) q->last_merge = NULL; - if (e->ops->elevator_remove_req_fn) + if (e->ops->elevator_remove_req_fn) { + bar_rq_hack_start(q); e->ops->elevator_remove_req_fn(q, rq); + bar_rq_hack_end(q); + } } int elv_queue_empty(request_queue_t *q) @@ -529,7 +550,7 @@ void elv_completed_request(request_queue * request is released from the driver, io must be done */ if (blk_account_rq(rq)) - q->in_flight--; + elv_dec_inflight(q); if (e->ops->elevator_completed_req_fn) e->ops->elevator_completed_req_fn(q, rq); Index: blk-fixes/drivers/block/ll_rw_blk.c =================================================================== --- blk-fixes.orig/drivers/block/ll_rw_blk.c 2005-06-05 14:53:34.000000000 +0900 +++ blk-fixes/drivers/block/ll_rw_blk.c 2005-06-05 14:53:34.000000000 +0900 @@ -291,10 +291,112 @@ static inline void rq_init(request_queue rq->end_io_data = NULL; } +static int __blk_queue_ordered(request_queue_t *q, int ordered, + prepare_flush_fn *prepare_flush_fn, + unsigned gfp_mask, int locked) +{ + void *rq0 = NULL, *rq1 = NULL, *rq2 = NULL; + unsigned long flags = 0; /* shut up, gcc */ + unsigned ordered_flags; + int ret = 0; + + might_sleep_if(gfp_mask & __GFP_WAIT); + + ordered_flags = ordered & QUEUE_ORDERED_FLAGS; + ordered &= ~QUEUE_ORDERED_FLAGS; + + if (ordered & (QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH) && + prepare_flush_fn == NULL) { + printk(KERN_ERR "blk_queue_ordered: prepare_flush_fn required\n"); + ret = -EINVAL; + goto out_unlocked; + } + + if (!locked) + spin_lock_irqsave(q->queue_lock, flags); + + if (q->ordseq) { + /* Queue flushing in progress, defer changing q->ordered. */ + q->next_ordered = ordered; + q->next_prepare_flush_fn = prepare_flush_fn; + ret = -EINPROGRESS; + goto out; + } + + switch (ordered) { + case QUEUE_ORDERED_NONE: + ordered_flags = 0; /* for '== QUEUE_ORDERED_NONE' tests */ + if (!q->pre_flush_rq) { + rq0 = q->pre_flush_rq; + rq1 = q->bar_rq; + rq2 = q->post_flush_rq; + q->pre_flush_rq = NULL; + q->bar_rq = NULL; + q->post_flush_rq = NULL; + } + break; + + case QUEUE_ORDERED_DRAIN: + case QUEUE_ORDERED_DRAIN_FLUSH: + case QUEUE_ORDERED_DRAIN_FUA: + case QUEUE_ORDERED_TAG: + case QUEUE_ORDERED_TAG_FLUSH: + case QUEUE_ORDERED_TAG_FUA: + if (q->pre_flush_rq) + break; + + if (!locked) + spin_unlock_irqrestore(q->queue_lock, flags); + if (!(rq0 = kmem_cache_alloc(request_cachep, gfp_mask)) || + !(rq1 = kmem_cache_alloc(request_cachep, gfp_mask)) || + !(rq2 = kmem_cache_alloc(request_cachep, gfp_mask))) { + printk(KERN_ERR "blk_queue_ordered: failed to " + "switch to 0x%x (out of memory)\n", ordered); + ret = -ENOMEM; + goto out_unlocked; + } + if (!locked) + spin_lock_irqsave(q->queue_lock, flags); + + if (!q->pre_flush_rq) { + q->pre_flush_rq = rq0; + q->bar_rq = rq1; + q->post_flush_rq = rq2; + rq0 = NULL; + rq1 = NULL; + rq2 = NULL; + } + break; + + default: + printk(KERN_ERR "blk_queue_ordered: bad value %d\n", ordered); + ret = -EINVAL; + goto out; + } + + q->ordered = ordered | ordered_flags; + q->next_ordered = q->ordered; + q->prepare_flush_fn = prepare_flush_fn; + + out: + if (!locked) + spin_unlock_irqrestore(q->queue_lock, flags); + out_unlocked: + if (rq0) + kmem_cache_free(request_cachep, rq0); + if (rq1) + kmem_cache_free(request_cachep, rq1); + if (rq2) + kmem_cache_free(request_cachep, rq2); + + return ret; +} + /** * 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_* + * @gfp_mask: allocation mask * * Description: * For journalled file systems, doing ordered writes on a commit @@ -303,32 +405,24 @@ static inline void rq_init(request_queue * feature should call this function and indicate so. * **/ -void blk_queue_ordered(request_queue_t *q, int flag) +extern int blk_queue_ordered(request_queue_t *q, unsigned ordered, + prepare_flush_fn *prepare_flush_fn, + unsigned gfp_mask) { - 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; - } + return __blk_queue_ordered(q, ordered, prepare_flush_fn, gfp_mask, 0); } EXPORT_SYMBOL(blk_queue_ordered); +extern int blk_queue_ordered_locked(request_queue_t *q, unsigned ordered, + prepare_flush_fn *prepare_flush_fn, + unsigned gfp_mask) +{ + return __blk_queue_ordered(q, ordered, prepare_flush_fn, gfp_mask, 1); +} + +EXPORT_SYMBOL(blk_queue_ordered_locked); + /** * blk_queue_issue_flush_fn - set function for issuing a flush * @q: the request queue @@ -349,165 +443,281 @@ 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) { - struct request *rq = flush_rq->end_io_data; - request_queue_t *q = rq->q; - - rq->flags |= REQ_BAR_PREFLUSH; - - 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 (!q->ordseq) + return 0; + return 1 << ffz(q->ordseq); } -static void blk_post_flush_end_io(struct request *flush_rq, int error) +static void ordered_set_error(request_queue_t *q, unsigned seq, int error) { - struct request *rq = flush_rq->end_io_data; - request_queue_t *q = rq->q; + unsigned ordered; - rq->flags |= REQ_BAR_POSTFLUSH; + q->orderr = error; - q->end_flush_fn(q, flush_rq); - clear_bit(QUEUE_FLAG_FLUSH, &q->queue_flags); - q->request_fn(q); + if (q->ordered & QUEUE_ORDERED_NOFALLBACK || + q->ordered != q->next_ordered) + return; + + switch (seq) { + case QUEUE_ORDSEQ_PREFLUSH: + if (q->ordered & QUEUE_ORDERED_TAG) + ordered = (q->ordered & ~QUEUE_ORDERED_TAG) | + QUEUE_ORDERED_DRAIN; + else + ordered = QUEUE_ORDERED_NONE; + break; + case QUEUE_ORDSEQ_BAR: + ordered = (q->ordered & ~QUEUE_ORDERED_FUA) | + QUEUE_ORDERED_POSTFLUSH; + break; + default: + return; + } + + blk_queue_ordered_locked(q, ordered, q->prepare_flush_fn, GFP_ATOMIC); } -struct request *blk_start_pre_flush(request_queue_t *q, struct request *rq) +void blk_ordered_complete_seq(request_queue_t *q, unsigned seq, int error) { - struct request *flush_rq = q->flush_rq; + struct request *rq; + int uptodate, changed = 0; - BUG_ON(!blk_barrier_rq(rq)); + if (error && !q->orderr) + ordered_set_error(q, seq, error); - if (test_and_set_bit(QUEUE_FLAG_FLUSH, &q->queue_flags)) - return NULL; + BUG_ON(q->ordseq & seq); + q->ordseq |= seq; - 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 - */ - 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; - } + * Okay, sequence complete. + */ + rq = q->orig_bar_rq; + uptodate = q->orderr ? q->orderr : 1; + + q->ordseq = 0; /* - * some drivers dequeue requests right away, some only after io - * completion. make sure the request is dequeued. + * We give a failed barrier request second chance if ordered + * has changed since it has started. */ - if (!list_empty(&rq->queuelist)) - blkdev_dequeue_request(rq); + if (q->next_ordered != q->ordered) + changed = !blk_queue_ordered_locked(q, q->next_ordered, + q->next_prepare_flush_fn, + GFP_ATOMIC); - elv_deactivate_request(q, rq); + if (!q->orderr || !changed || q->ordered == QUEUE_ORDERED_NONE) { + end_that_request_first(rq, uptodate, rq->hard_nr_sectors); + end_that_request_last(rq, uptodate); + } else + blk_requeue_request(q, rq); +} - flush_rq->end_io_data = rq; - flush_rq->end_io = blk_pre_flush_end_io; +static void pre_flush_end_io(struct request *rq, int error) +{ + blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_PREFLUSH, error); +} - __elv_add_request(q, flush_rq, ELEVATOR_INSERT_FRONT, 0); - return flush_rq; +static void bar_end_io(struct request *rq, int error) +{ + blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_BAR, error); } -static void blk_start_post_flush(request_queue_t *q, struct request *rq) +static void post_flush_end_io(struct request *rq, int error) { - struct request *flush_rq = q->flush_rq; + blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_POSTFLUSH, error); +} - BUG_ON(!blk_barrier_rq(rq)); +static void queue_flush(request_queue_t *q, unsigned which) +{ + struct request *rq; + rq_end_io_fn *end_io; - 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 (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; + } - if (q->prepare_flush_fn(q, flush_rq)) { - flush_rq->end_io_data = rq; - flush_rq->end_io = blk_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, flush_rq, ELEVATOR_INSERT_FRONT, 0); - q->request_fn(q); - } + __elv_add_request(q, rq, ELEVATOR_INSERT_FRONT, 0); } -static inline int blk_check_end_barrier(request_queue_t *q, struct request *rq, - int sectors) +static inline struct request *start_ordered(request_queue_t *q, + struct request *rq) { - if (sectors > rq->nr_sectors) - sectors = rq->nr_sectors; + q->bi_size = 0; + q->orderr = 0; + q->ordseq |= QUEUE_ORDSEQ_STARTED; - rq->nr_sectors -= sectors; - return rq->nr_sectors; -} + /* + * Prep proxy barrier request. + */ + 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; -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; + /* + * 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; - if (!blk_check_end_barrier(q, rq, sectors)) { - unsigned long flags = 0; + __elv_add_request(q, rq, ELEVATOR_INSERT_FRONT, 0); - if (!queue_locked) - spin_lock_irqsave(q->queue_lock, flags); + if (q->ordered & QUEUE_ORDERED_PREFLUSH) { + queue_flush(q, QUEUE_ORDERED_PREFLUSH); + rq = q->pre_flush_rq; + } else + q->ordseq |= QUEUE_ORDSEQ_PREFLUSH; - blk_start_post_flush(q, rq); + if ((q->ordered & QUEUE_ORDERED_TAG) || q->in_flight == 0) + q->ordseq |= QUEUE_ORDSEQ_DRAIN; + else + rq = NULL; - if (!queue_locked) - spin_unlock_irqrestore(q->queue_lock, flags); + return rq; +} + +int blk_do_ordered(request_queue_t *q, struct request **rqp) +{ + struct request *rq = *rqp, *allowed_rq; + int is_barrier = blk_fs_request(rq) && blk_barrier_rq(rq); + + if (!q->ordseq) { + if (!is_barrier) + return 1; + + if (q->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; + } + } + + if (q->ordered & QUEUE_ORDERED_TAG) { + if (blk_fs_request(rq) && 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); + request_queue_t *q = bio->bi_private; + struct bio_vec *bvec; + int i; + + /* + * 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; } -EXPORT_SYMBOL(blk_complete_barrier_rq); -/** - * 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) +static inline int ordered_bio_endio(struct request *rq, struct bio *bio, + unsigned int nbytes, int error) { - return __blk_complete_barrier_rq(q, rq, sectors, 1); + 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) + ordered_set_error(q, QUEUE_ORDSEQ_BAR, 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 @@ -1031,6 +1241,7 @@ static char *rq_flags[] = { "REQ_FAILFAST", "REQ_SOFTBARRIER", "REQ_HARDBARRIER", + "REQ_FUA", "REQ_CMD", "REQ_NOMERGE", "REQ_STARTED", @@ -1614,7 +1825,7 @@ void blk_cleanup_queue(request_queue_t * if (q->queue_tags) __blk_queue_free_tags(q); - blk_queue_ordered(q, QUEUE_ORDERED_NONE); + blk_queue_ordered(q, QUEUE_ORDERED_NONE, NULL, 0); kmem_cache_free(requestq_cachep, q); } @@ -3034,7 +3245,8 @@ static int __end_that_request_first(stru 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 { @@ -3089,7 +3301,8 @@ static int __end_that_request_first(stru * 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; Index: blk-fixes/include/linux/blkdev.h =================================================================== --- blk-fixes.orig/include/linux/blkdev.h 2005-06-05 14:53:32.000000000 +0900 +++ blk-fixes/include/linux/blkdev.h 2005-06-05 14:53:34.000000000 +0900 @@ -205,6 +205,7 @@ enum rq_flag_bits { __REQ_FAILFAST, /* no low level driver retries */ __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 */ @@ -227,9 +228,6 @@ 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_NR_BITS, /* stops here */ }; @@ -237,6 +235,7 @@ enum rq_flag_bits { #define REQ_FAILFAST (1 << __REQ_FAILFAST) #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) @@ -255,9 +254,6 @@ 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) /* * State information carried for REQ_PM_SUSPEND and REQ_PM_RESUME @@ -287,8 +283,7 @@ 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, @@ -329,7 +324,6 @@ 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; /* * Auto-unplugging state @@ -409,14 +403,13 @@ 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 ordseq; + int orderr; + struct request *pre_flush_rq, *bar_rq, *post_flush_rq; + struct request *orig_bar_rq; + unsigned int bi_size; + unsigned int ordered, next_ordered; + prepare_flush_fn *next_prepare_flush_fn; }; #define RQ_INACTIVE (-1) @@ -434,19 +427,67 @@ enum { #define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */ #define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */ #define QUEUE_FLAG_DRAIN 8 /* draining queue for sched switch */ -#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 + * + * The following flags can be or'd. + * + * NOFALLBACK : disable auto-fallback + */ + 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_NOFALLBACK = 0x80, + + QUEUE_ORDERED_FLAGS = QUEUE_ORDERED_NOFALLBACK, + + 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) #define blk_noretry_request(rq) ((rq)->flags & REQ_FAILFAST) #define blk_rq_started(rq) ((rq)->flags & REQ_STARTED) -#define blk_account_rq(rq) (blk_rq_started(rq) && blk_fs_request(rq)) +#define blk_account_rq(rq) \ + (blk_rq_started(rq) && blk_fs_request(rq) && rq != rq->q->bar_rq) #define blk_pm_suspend_request(rq) ((rq)->flags & REQ_PM_SUSPEND) #define blk_pm_resume_request(rq) ((rq)->flags & REQ_PM_RESUME) @@ -454,8 +495,7 @@ enum { ((rq)->flags & (REQ_PM_SUSPEND | REQ_PM_RESUME)) #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) @@ -636,11 +676,12 @@ extern void blk_queue_prep_rq(request_qu 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 *, unsigned); +extern int blk_queue_ordered_locked(request_queue_t *, unsigned, prepare_flush_fn *, unsigned); 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 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 *);