From 7c94e1c157a227837b04f02f5edeff8301410ba2 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Thu, 25 Sep 2014 23:23:43 +0800 Subject: block: introduce blk_flush_queue to drive flush machinery This patch introduces 'struct blk_flush_queue' and puts all flush machinery related fields into this structure, so that - flush implementation details aren't exposed to driver - it is easy to convert to per dispatch-queue flush machinery This patch is basically a mechanical replacement. Reviewed-by: Christoph Hellwig Signed-off-by: Ming Lei Signed-off-by: Jens Axboe --- block/blk-flush.c | 109 ++++++++++++++++++++++++++++++++++-------------------- 1 file changed, 68 insertions(+), 41 deletions(-) (limited to 'block/blk-flush.c') diff --git a/block/blk-flush.c b/block/blk-flush.c index caf44756d3293..b01a86d6bf867 100644 --- a/block/blk-flush.c +++ b/block/blk-flush.c @@ -28,7 +28,7 @@ * * The actual execution of flush is double buffered. Whenever a request * needs to execute PRE or POSTFLUSH, it queues at - * q->flush_queue[q->flush_pending_idx]. Once certain criteria are met, a + * fq->flush_queue[fq->flush_pending_idx]. Once certain criteria are met, a * flush is issued and the pending_idx is toggled. When the flush * completes, all the requests which were pending are proceeded to the next * step. This allows arbitrary merging of different types of FLUSH/FUA @@ -155,7 +155,7 @@ static bool blk_flush_queue_rq(struct request *rq, bool add_front) * completion and trigger the next step. * * CONTEXT: - * spin_lock_irq(q->queue_lock or q->mq_flush_lock) + * spin_lock_irq(q->queue_lock or fq->mq_flush_lock) * * RETURNS: * %true if requests were added to the dispatch queue, %false otherwise. @@ -164,7 +164,8 @@ static bool blk_flush_complete_seq(struct request *rq, unsigned int seq, int error) { struct request_queue *q = rq->q; - struct list_head *pending = &q->flush_queue[q->flush_pending_idx]; + struct blk_flush_queue *fq = blk_get_flush_queue(q); + struct list_head *pending = &fq->flush_queue[fq->flush_pending_idx]; bool queued = false, kicked; BUG_ON(rq->flush.seq & seq); @@ -180,12 +181,12 @@ static bool blk_flush_complete_seq(struct request *rq, unsigned int seq, case REQ_FSEQ_POSTFLUSH: /* queue for flush */ if (list_empty(pending)) - q->flush_pending_since = jiffies; + fq->flush_pending_since = jiffies; list_move_tail(&rq->flush.list, pending); break; case REQ_FSEQ_DATA: - list_move_tail(&rq->flush.list, &q->flush_data_in_flight); + list_move_tail(&rq->flush.list, &fq->flush_data_in_flight); queued = blk_flush_queue_rq(rq, true); break; @@ -220,17 +221,18 @@ static void flush_end_io(struct request *flush_rq, int error) bool queued = false; struct request *rq, *n; unsigned long flags = 0; + struct blk_flush_queue *fq = blk_get_flush_queue(q); if (q->mq_ops) { - spin_lock_irqsave(&q->mq_flush_lock, flags); + spin_lock_irqsave(&fq->mq_flush_lock, flags); flush_rq->tag = -1; } - running = &q->flush_queue[q->flush_running_idx]; - BUG_ON(q->flush_pending_idx == q->flush_running_idx); + running = &fq->flush_queue[fq->flush_running_idx]; + BUG_ON(fq->flush_pending_idx == fq->flush_running_idx); /* account completion of the flush request */ - q->flush_running_idx ^= 1; + fq->flush_running_idx ^= 1; if (!q->mq_ops) elv_completed_request(q, flush_rq); @@ -254,13 +256,13 @@ static void flush_end_io(struct request *flush_rq, int error) * directly into request_fn may confuse the driver. Always use * kblockd. */ - if (queued || q->flush_queue_delayed) { + if (queued || fq->flush_queue_delayed) { WARN_ON(q->mq_ops); blk_run_queue_async(q); } - q->flush_queue_delayed = 0; + fq->flush_queue_delayed = 0; if (q->mq_ops) - spin_unlock_irqrestore(&q->mq_flush_lock, flags); + spin_unlock_irqrestore(&fq->mq_flush_lock, flags); } /** @@ -271,33 +273,34 @@ static void flush_end_io(struct request *flush_rq, int error) * Please read the comment at the top of this file for more info. * * CONTEXT: - * spin_lock_irq(q->queue_lock or q->mq_flush_lock) + * spin_lock_irq(q->queue_lock or fq->mq_flush_lock) * * RETURNS: * %true if flush was issued, %false otherwise. */ static bool blk_kick_flush(struct request_queue *q) { - struct list_head *pending = &q->flush_queue[q->flush_pending_idx]; + struct blk_flush_queue *fq = blk_get_flush_queue(q); + struct list_head *pending = &fq->flush_queue[fq->flush_pending_idx]; struct request *first_rq = list_first_entry(pending, struct request, flush.list); - struct request *flush_rq = q->flush_rq; + struct request *flush_rq = fq->flush_rq; /* C1 described at the top of this file */ - if (q->flush_pending_idx != q->flush_running_idx || list_empty(pending)) + if (fq->flush_pending_idx != fq->flush_running_idx || list_empty(pending)) return false; /* C2 and C3 */ - if (!list_empty(&q->flush_data_in_flight) && + if (!list_empty(&fq->flush_data_in_flight) && time_before(jiffies, - q->flush_pending_since + FLUSH_PENDING_TIMEOUT)) + fq->flush_pending_since + FLUSH_PENDING_TIMEOUT)) return false; /* * Issue flush and toggle pending_idx. This makes pending_idx * different from running_idx, which means flush is in flight. */ - q->flush_pending_idx ^= 1; + fq->flush_pending_idx ^= 1; blk_rq_init(q, flush_rq); if (q->mq_ops) @@ -329,6 +332,7 @@ static void mq_flush_data_end_io(struct request *rq, int error) struct blk_mq_hw_ctx *hctx; struct blk_mq_ctx *ctx; unsigned long flags; + struct blk_flush_queue *fq = blk_get_flush_queue(q); ctx = rq->mq_ctx; hctx = q->mq_ops->map_queue(q, ctx->cpu); @@ -337,10 +341,10 @@ static void mq_flush_data_end_io(struct request *rq, int error) * After populating an empty queue, kick it to avoid stall. Read * the comment in flush_end_io(). */ - spin_lock_irqsave(&q->mq_flush_lock, flags); + spin_lock_irqsave(&fq->mq_flush_lock, flags); if (blk_flush_complete_seq(rq, REQ_FSEQ_DATA, error)) blk_mq_run_hw_queue(hctx, true); - spin_unlock_irqrestore(&q->mq_flush_lock, flags); + spin_unlock_irqrestore(&fq->mq_flush_lock, flags); } /** @@ -408,11 +412,13 @@ void blk_insert_flush(struct request *rq) rq->cmd_flags |= REQ_FLUSH_SEQ; rq->flush.saved_end_io = rq->end_io; /* Usually NULL */ if (q->mq_ops) { + struct blk_flush_queue *fq = blk_get_flush_queue(q); + rq->end_io = mq_flush_data_end_io; - spin_lock_irq(&q->mq_flush_lock); + spin_lock_irq(&fq->mq_flush_lock); blk_flush_complete_seq(rq, REQ_FSEQ_ACTIONS & ~policy, 0); - spin_unlock_irq(&q->mq_flush_lock); + spin_unlock_irq(&fq->mq_flush_lock); return; } rq->end_io = flush_data_end_io; @@ -473,31 +479,52 @@ int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask, } EXPORT_SYMBOL(blkdev_issue_flush); -static int blk_mq_init_flush(struct request_queue *q) +static struct blk_flush_queue *blk_alloc_flush_queue( + struct request_queue *q) { - struct blk_mq_tag_set *set = q->tag_set; + struct blk_flush_queue *fq; + int rq_sz = sizeof(struct request); - spin_lock_init(&q->mq_flush_lock); + fq = kzalloc(sizeof(*fq), GFP_KERNEL); + if (!fq) + goto fail; - q->flush_rq = kzalloc(round_up(sizeof(struct request) + - set->cmd_size, cache_line_size()), - GFP_KERNEL); - if (!q->flush_rq) - return -ENOMEM; - return 0; + if (q->mq_ops) { + spin_lock_init(&fq->mq_flush_lock); + rq_sz = round_up(rq_sz + q->tag_set->cmd_size, + cache_line_size()); + } + + fq->flush_rq = kzalloc(rq_sz, GFP_KERNEL); + if (!fq->flush_rq) + goto fail_rq; + + INIT_LIST_HEAD(&fq->flush_queue[0]); + INIT_LIST_HEAD(&fq->flush_queue[1]); + INIT_LIST_HEAD(&fq->flush_data_in_flight); + + return fq; + + fail_rq: + kfree(fq); + fail: + return NULL; } -int blk_init_flush(struct request_queue *q) +static void blk_free_flush_queue(struct blk_flush_queue *fq) { - INIT_LIST_HEAD(&q->flush_queue[0]); - INIT_LIST_HEAD(&q->flush_queue[1]); - INIT_LIST_HEAD(&q->flush_data_in_flight); + /* bio based request queue hasn't flush queue */ + if (!fq) + return; - if (q->mq_ops) - return blk_mq_init_flush(q); + kfree(fq->flush_rq); + kfree(fq); +} - q->flush_rq = kzalloc(sizeof(struct request), GFP_KERNEL); - if (!q->flush_rq) +int blk_init_flush(struct request_queue *q) +{ + q->fq = blk_alloc_flush_queue(q); + if (!q->fq) return -ENOMEM; return 0; @@ -505,5 +532,5 @@ int blk_init_flush(struct request_queue *q) void blk_exit_flush(struct request_queue *q) { - kfree(q->flush_rq); + blk_free_flush_queue(q->fq); } -- cgit v1.2.3