From e443343e509aac82e7281020f25bf8fa0dd46ab7 Mon Sep 17 00:00:00 2001 From: Stefan Haberland Date: Mon, 22 May 2017 10:59:11 +0200 Subject: [PATCH] s390/dasd: blk-mq conversion Use new blk-mq interfaces. Use multiple queues and also use the block layer complete helper that finish the IO on the CPU that initiated it. Reviewed-by: Jan Hoeppner Signed-off-by: Stefan Haberland Signed-off-by: Martin Schwidefsky --- drivers/s390/block/dasd.c | 331 ++++++++++++++++--------------- drivers/s390/block/dasd_devmap.c | 8 +- drivers/s390/block/dasd_int.h | 19 +- 3 files changed, 193 insertions(+), 165 deletions(-) diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c index 9c97ad1ee121..ea19b4ff87a2 100644 --- a/drivers/s390/block/dasd.c +++ b/drivers/s390/block/dasd.c @@ -62,7 +62,6 @@ MODULE_LICENSE("GPL"); static int dasd_alloc_queue(struct dasd_block *); static void dasd_setup_queue(struct dasd_block *); static void dasd_free_queue(struct dasd_block *); -static void dasd_flush_request_queue(struct dasd_block *); static int dasd_flush_block_queue(struct dasd_block *); static void dasd_device_tasklet(struct dasd_device *); static void dasd_block_tasklet(struct dasd_block *); @@ -158,7 +157,6 @@ struct dasd_block *dasd_alloc_block(void) /* open_count = 0 means device online but not in use */ atomic_set(&block->open_count, -1); - spin_lock_init(&block->request_queue_lock); atomic_set(&block->tasklet_scheduled, 0); tasklet_init(&block->tasklet, (void (*)(unsigned long)) dasd_block_tasklet, @@ -391,7 +389,6 @@ static int dasd_state_ready_to_basic(struct dasd_device *device) device->state = DASD_STATE_READY; return rc; } - dasd_flush_request_queue(block); dasd_destroy_partitions(block); block->blocks = 0; block->bp_block = 0; @@ -1645,8 +1642,10 @@ void dasd_generic_handle_state_change(struct dasd_device *device) dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING); dasd_schedule_device_bh(device); - if (device->block) + if (device->block) { dasd_schedule_block_bh(device->block); + blk_mq_run_hw_queues(device->block->request_queue, true); + } } EXPORT_SYMBOL_GPL(dasd_generic_handle_state_change); @@ -2638,6 +2637,7 @@ static void dasd_block_timeout(unsigned long ptr) dasd_device_remove_stop_bits(block->base, DASD_STOPPED_PENDING); spin_unlock_irqrestore(get_ccwdev_lock(block->base->cdev), flags); dasd_schedule_block_bh(block); + blk_mq_run_hw_queues(block->request_queue, true); } /* @@ -2677,115 +2677,11 @@ static void __dasd_process_erp(struct dasd_device *device, erp_fn(cqr); } -/* - * Fetch requests from the block device queue. - */ -static void __dasd_process_request_queue(struct dasd_block *block) -{ - struct request_queue *queue; - struct request *req; - struct dasd_ccw_req *cqr; - struct dasd_device *basedev; - unsigned long flags; - queue = block->request_queue; - basedev = block->base; - /* No queue ? Then there is nothing to do. */ - if (queue == NULL) - return; - - /* - * We requeue request from the block device queue to the ccw - * queue only in two states. In state DASD_STATE_READY the - * partition detection is done and we need to requeue requests - * for that. State DASD_STATE_ONLINE is normal block device - * operation. - */ - if (basedev->state < DASD_STATE_READY) { - while ((req = blk_fetch_request(block->request_queue))) - __blk_end_request_all(req, BLK_STS_IOERR); - return; - } - - /* - * if device is stopped do not fetch new requests - * except failfast is active which will let requests fail - * immediately in __dasd_block_start_head() - */ - if (basedev->stopped && !(basedev->features & DASD_FEATURE_FAILFAST)) - return; - - /* Now we try to fetch requests from the request queue */ - while ((req = blk_peek_request(queue))) { - if (basedev->features & DASD_FEATURE_READONLY && - rq_data_dir(req) == WRITE) { - DBF_DEV_EVENT(DBF_ERR, basedev, - "Rejecting write request %p", - req); - blk_start_request(req); - __blk_end_request_all(req, BLK_STS_IOERR); - continue; - } - if (test_bit(DASD_FLAG_ABORTALL, &basedev->flags) && - (basedev->features & DASD_FEATURE_FAILFAST || - blk_noretry_request(req))) { - DBF_DEV_EVENT(DBF_ERR, basedev, - "Rejecting failfast request %p", - req); - blk_start_request(req); - __blk_end_request_all(req, BLK_STS_TIMEOUT); - continue; - } - cqr = basedev->discipline->build_cp(basedev, block, req); - if (IS_ERR(cqr)) { - if (PTR_ERR(cqr) == -EBUSY) - break; /* normal end condition */ - if (PTR_ERR(cqr) == -ENOMEM) - break; /* terminate request queue loop */ - if (PTR_ERR(cqr) == -EAGAIN) { - /* - * The current request cannot be build right - * now, we have to try later. If this request - * is the head-of-queue we stop the device - * for 1/2 second. - */ - if (!list_empty(&block->ccw_queue)) - break; - spin_lock_irqsave( - get_ccwdev_lock(basedev->cdev), flags); - dasd_device_set_stop_bits(basedev, - DASD_STOPPED_PENDING); - spin_unlock_irqrestore( - get_ccwdev_lock(basedev->cdev), flags); - dasd_block_set_timer(block, HZ/2); - break; - } - DBF_DEV_EVENT(DBF_ERR, basedev, - "CCW creation failed (rc=%ld) " - "on request %p", - PTR_ERR(cqr), req); - blk_start_request(req); - __blk_end_request_all(req, BLK_STS_IOERR); - continue; - } - /* - * Note: callback is set to dasd_return_cqr_cb in - * __dasd_block_start_head to cover erp requests as well - */ - cqr->callback_data = (void *) req; - cqr->status = DASD_CQR_FILLED; - req->completion_data = cqr; - blk_start_request(req); - list_add_tail(&cqr->blocklist, &block->ccw_queue); - INIT_LIST_HEAD(&cqr->devlist); - dasd_profile_start(block, cqr, req); - } -} - static void __dasd_cleanup_cqr(struct dasd_ccw_req *cqr) { struct request *req; - int status; blk_status_t error = BLK_STS_OK; + int status; req = (struct request *) cqr->callback_data; dasd_profile_end(cqr->block, cqr, req); @@ -2809,7 +2705,19 @@ static void __dasd_cleanup_cqr(struct dasd_ccw_req *cqr) break; } } - __blk_end_request_all(req, error); + + /* + * We need to take care for ETIMEDOUT errors here since the + * complete callback does not get called in this case. + * Take care of all errors here and avoid additional code to + * transfer the error value to the complete callback. + */ + if (error) { + blk_mq_end_request(req, error); + blk_mq_run_hw_queues(req->q, true); + } else { + blk_mq_complete_request(req); + } } /* @@ -2938,27 +2846,30 @@ static void dasd_block_tasklet(struct dasd_block *block) struct list_head final_queue; struct list_head *l, *n; struct dasd_ccw_req *cqr; + struct dasd_queue *dq; atomic_set(&block->tasklet_scheduled, 0); INIT_LIST_HEAD(&final_queue); - spin_lock(&block->queue_lock); + spin_lock_irq(&block->queue_lock); /* Finish off requests on ccw queue */ __dasd_process_block_ccw_queue(block, &final_queue); - spin_unlock(&block->queue_lock); + spin_unlock_irq(&block->queue_lock); + /* Now call the callback function of requests with final status */ - spin_lock_irq(&block->request_queue_lock); list_for_each_safe(l, n, &final_queue) { cqr = list_entry(l, struct dasd_ccw_req, blocklist); + dq = cqr->dq; + spin_lock_irq(&dq->lock); list_del_init(&cqr->blocklist); __dasd_cleanup_cqr(cqr); + spin_unlock_irq(&dq->lock); } - spin_lock(&block->queue_lock); - /* Get new request from the block device request queue */ - __dasd_process_request_queue(block); + + spin_lock_irq(&block->queue_lock); /* Now check if the head of the ccw queue needs to be started. */ __dasd_block_start_head(block); - spin_unlock(&block->queue_lock); - spin_unlock_irq(&block->request_queue_lock); + spin_unlock_irq(&block->queue_lock); + if (waitqueue_active(&shutdown_waitq)) wake_up(&shutdown_waitq); dasd_put_device(block->base); @@ -2977,14 +2888,13 @@ static int _dasd_requeue_request(struct dasd_ccw_req *cqr) { struct dasd_block *block = cqr->block; struct request *req; - unsigned long flags; if (!block) return -EINVAL; - spin_lock_irqsave(&block->request_queue_lock, flags); + spin_lock_irq(&cqr->dq->lock); req = (struct request *) cqr->callback_data; - blk_requeue_request(block->request_queue, req); - spin_unlock_irqrestore(&block->request_queue_lock, flags); + blk_mq_requeue_request(req, false); + spin_unlock_irq(&cqr->dq->lock); return 0; } @@ -2999,6 +2909,7 @@ static int dasd_flush_block_queue(struct dasd_block *block) struct dasd_ccw_req *cqr, *n; int rc, i; struct list_head flush_queue; + unsigned long flags; INIT_LIST_HEAD(&flush_queue); spin_lock_bh(&block->queue_lock); @@ -3037,11 +2948,11 @@ static int dasd_flush_block_queue(struct dasd_block *block) goto restart_cb; } /* call the callback function */ - spin_lock_irq(&block->request_queue_lock); + spin_lock_irqsave(&cqr->dq->lock, flags); cqr->endclk = get_tod_clock(); list_del_init(&cqr->blocklist); __dasd_cleanup_cqr(cqr); - spin_unlock_irq(&block->request_queue_lock); + spin_unlock_irqrestore(&cqr->dq->lock, flags); } return rc; } @@ -3069,42 +2980,114 @@ EXPORT_SYMBOL(dasd_schedule_block_bh); /* * Dasd request queue function. Called from ll_rw_blk.c */ -static void do_dasd_request(struct request_queue *queue) +static blk_status_t do_dasd_request(struct blk_mq_hw_ctx *hctx, + const struct blk_mq_queue_data *qd) { - struct dasd_block *block; + struct dasd_block *block = hctx->queue->queuedata; + struct dasd_queue *dq = hctx->driver_data; + struct request *req = qd->rq; + struct dasd_device *basedev; + struct dasd_ccw_req *cqr; + blk_status_t rc = BLK_STS_OK; - block = queue->queuedata; + basedev = block->base; + spin_lock_irq(&dq->lock); + if (basedev->state < DASD_STATE_READY) { + DBF_DEV_EVENT(DBF_ERR, basedev, + "device not ready for request %p", req); + rc = BLK_STS_IOERR; + goto out; + } + + /* + * if device is stopped do not fetch new requests + * except failfast is active which will let requests fail + * immediately in __dasd_block_start_head() + */ + if (basedev->stopped && !(basedev->features & DASD_FEATURE_FAILFAST)) { + DBF_DEV_EVENT(DBF_ERR, basedev, + "device stopped request %p", req); + rc = BLK_STS_RESOURCE; + goto out; + } + + if (basedev->features & DASD_FEATURE_READONLY && + rq_data_dir(req) == WRITE) { + DBF_DEV_EVENT(DBF_ERR, basedev, + "Rejecting write request %p", req); + rc = BLK_STS_IOERR; + goto out; + } + + if (test_bit(DASD_FLAG_ABORTALL, &basedev->flags) && + (basedev->features & DASD_FEATURE_FAILFAST || + blk_noretry_request(req))) { + DBF_DEV_EVENT(DBF_ERR, basedev, + "Rejecting failfast request %p", req); + rc = BLK_STS_IOERR; + goto out; + } + + cqr = basedev->discipline->build_cp(basedev, block, req); + if (IS_ERR(cqr)) { + if (PTR_ERR(cqr) == -EBUSY || + PTR_ERR(cqr) == -ENOMEM || + PTR_ERR(cqr) == -EAGAIN) { + rc = BLK_STS_RESOURCE; + goto out; + } + DBF_DEV_EVENT(DBF_ERR, basedev, + "CCW creation failed (rc=%ld) on request %p", + PTR_ERR(cqr), req); + rc = BLK_STS_IOERR; + goto out; + } + /* + * Note: callback is set to dasd_return_cqr_cb in + * __dasd_block_start_head to cover erp requests as well + */ + cqr->callback_data = req; + cqr->status = DASD_CQR_FILLED; + cqr->dq = dq; + req->completion_data = cqr; + blk_mq_start_request(req); spin_lock(&block->queue_lock); - /* Get new request from the block device request queue */ - __dasd_process_request_queue(block); - /* Now check if the head of the ccw queue needs to be started. */ - __dasd_block_start_head(block); + list_add_tail(&cqr->blocklist, &block->ccw_queue); + INIT_LIST_HEAD(&cqr->devlist); + dasd_profile_start(block, cqr, req); + dasd_schedule_block_bh(block); spin_unlock(&block->queue_lock); + +out: + spin_unlock_irq(&dq->lock); + return rc; } /* * Block timeout callback, called from the block layer * - * request_queue lock is held on entry. - * * Return values: * BLK_EH_RESET_TIMER if the request should be left running * BLK_EH_NOT_HANDLED if the request is handled or terminated * by the driver. */ -enum blk_eh_timer_return dasd_times_out(struct request *req) +enum blk_eh_timer_return dasd_times_out(struct request *req, bool reserved) { struct dasd_ccw_req *cqr = req->completion_data; struct dasd_block *block = req->q->queuedata; struct dasd_device *device; + unsigned long flags; int rc = 0; if (!cqr) return BLK_EH_NOT_HANDLED; + spin_lock_irqsave(&cqr->dq->lock, flags); device = cqr->startdev ? cqr->startdev : block->base; - if (!device->blk_timeout) + if (!device->blk_timeout) { + spin_unlock_irqrestore(&cqr->dq->lock, flags); return BLK_EH_RESET_TIMER; + } DBF_DEV_EVENT(DBF_WARNING, device, " dasd_times_out cqr %p status %x", cqr, cqr->status); @@ -3154,19 +3137,64 @@ enum blk_eh_timer_return dasd_times_out(struct request *req) } dasd_schedule_block_bh(block); spin_unlock(&block->queue_lock); + spin_unlock_irqrestore(&cqr->dq->lock, flags); return rc ? BLK_EH_RESET_TIMER : BLK_EH_NOT_HANDLED; } +static int dasd_init_hctx(struct blk_mq_hw_ctx *hctx, void *data, + unsigned int idx) +{ + struct dasd_queue *dq = kzalloc(sizeof(*dq), GFP_KERNEL); + + if (!dq) + return -ENOMEM; + + spin_lock_init(&dq->lock); + hctx->driver_data = dq; + + return 0; +} + +static void dasd_exit_hctx(struct blk_mq_hw_ctx *hctx, unsigned int idx) +{ + kfree(hctx->driver_data); + hctx->driver_data = NULL; +} + +static void dasd_request_done(struct request *req) +{ + blk_mq_end_request(req, 0); + blk_mq_run_hw_queues(req->q, true); +} + +static struct blk_mq_ops dasd_mq_ops = { + .queue_rq = do_dasd_request, + .complete = dasd_request_done, + .timeout = dasd_times_out, + .init_hctx = dasd_init_hctx, + .exit_hctx = dasd_exit_hctx, +}; + /* * Allocate and initialize request queue and default I/O scheduler. */ static int dasd_alloc_queue(struct dasd_block *block) { - block->request_queue = blk_init_queue(do_dasd_request, - &block->request_queue_lock); - if (block->request_queue == NULL) - return -ENOMEM; + int rc; + + block->tag_set.ops = &dasd_mq_ops; + block->tag_set.nr_hw_queues = DASD_NR_HW_QUEUES; + block->tag_set.queue_depth = DASD_MAX_LCU_DEV * DASD_REQ_PER_DEV; + block->tag_set.flags = BLK_MQ_F_SHOULD_MERGE; + + rc = blk_mq_alloc_tag_set(&block->tag_set); + if (rc) + return rc; + + block->request_queue = blk_mq_init_queue(&block->tag_set); + if (IS_ERR(block->request_queue)) + return PTR_ERR(block->request_queue); block->request_queue->queuedata = block; @@ -3229,26 +3257,11 @@ static void dasd_free_queue(struct dasd_block *block) { if (block->request_queue) { blk_cleanup_queue(block->request_queue); + blk_mq_free_tag_set(&block->tag_set); block->request_queue = NULL; } } -/* - * Flush request on the request queue. - */ -static void dasd_flush_request_queue(struct dasd_block *block) -{ - struct request *req; - - if (!block->request_queue) - return; - - spin_lock_irq(&block->request_queue_lock); - while ((req = blk_fetch_request(block->request_queue))) - __blk_end_request_all(req, BLK_STS_IOERR); - spin_unlock_irq(&block->request_queue_lock); -} - static int dasd_open(struct block_device *bdev, fmode_t mode) { struct dasd_device *base; @@ -3744,8 +3757,10 @@ int dasd_generic_path_operational(struct dasd_device *device) return 1; } dasd_schedule_device_bh(device); - if (device->block) + if (device->block) { dasd_schedule_block_bh(device->block); + blk_mq_run_hw_queues(device->block->request_queue, true); + } if (!device->stopped) wake_up(&generic_waitq); @@ -4008,8 +4023,10 @@ int dasd_generic_restore_device(struct ccw_device *cdev) */ device->stopped |= DASD_UNRESUMED_PM; - if (device->block) + if (device->block) { dasd_schedule_block_bh(device->block); + blk_mq_run_hw_queues(device->block->request_queue, true); + } clear_bit(DASD_FLAG_SUSPENDED, &device->flags); dasd_put_device(device); diff --git a/drivers/s390/block/dasd_devmap.c b/drivers/s390/block/dasd_devmap.c index e38042ce94e6..c95a4784c191 100644 --- a/drivers/s390/block/dasd_devmap.c +++ b/drivers/s390/block/dasd_devmap.c @@ -1326,7 +1326,7 @@ dasd_timeout_store(struct device *dev, struct device_attribute *attr, { struct dasd_device *device; struct request_queue *q; - unsigned long val, flags; + unsigned long val; device = dasd_device_from_cdev(to_ccwdev(dev)); if (IS_ERR(device) || !device->block) @@ -1342,16 +1342,10 @@ dasd_timeout_store(struct device *dev, struct device_attribute *attr, dasd_put_device(device); return -ENODEV; } - spin_lock_irqsave(&device->block->request_queue_lock, flags); - if (!val) - blk_queue_rq_timed_out(q, NULL); - else - blk_queue_rq_timed_out(q, dasd_times_out); device->blk_timeout = val; blk_queue_rq_timeout(q, device->blk_timeout * HZ); - spin_unlock_irqrestore(&device->block->request_queue_lock, flags); dasd_put_device(device); return count; diff --git a/drivers/s390/block/dasd_int.h b/drivers/s390/block/dasd_int.h index f9e25fc03d6b..db470bd10175 100644 --- a/drivers/s390/block/dasd_int.h +++ b/drivers/s390/block/dasd_int.h @@ -56,6 +56,7 @@ #include #include #include +#include /* DASD discipline magic */ #define DASD_ECKD_MAGIC 0xC5C3D2C4 @@ -185,6 +186,7 @@ struct dasd_ccw_req { char status; /* status of this request */ short retries; /* A retry counter */ unsigned long flags; /* flags of this request */ + struct dasd_queue *dq; /* ... and how */ unsigned long starttime; /* jiffies time of request start */ @@ -248,6 +250,16 @@ struct dasd_ccw_req { #define DASD_CQR_SUPPRESS_IL 6 /* Suppress 'Incorrect Length' error */ #define DASD_CQR_SUPPRESS_CR 7 /* Suppress 'Command Reject' error */ +/* + * There is no reliable way to determine the number of available CPUs on + * LPAR but there is no big performance difference between 1 and the + * maximum CPU number. + * 64 is a good trade off performance wise. + */ +#define DASD_NR_HW_QUEUES 64 +#define DASD_MAX_LCU_DEV 256 +#define DASD_REQ_PER_DEV 4 + /* Signature for error recovery functions. */ typedef struct dasd_ccw_req *(*dasd_erp_fn_t) (struct dasd_ccw_req *); @@ -539,6 +551,7 @@ struct dasd_block { struct gendisk *gdp; struct request_queue *request_queue; spinlock_t request_queue_lock; + struct blk_mq_tag_set tag_set; struct block_device *bdev; atomic_t open_count; @@ -563,6 +576,10 @@ struct dasd_attention_data { __u8 lpum; }; +struct dasd_queue { + spinlock_t lock; +}; + /* reasons why device (ccw_device_start) was stopped */ #define DASD_STOPPED_NOT_ACC 1 /* not accessible */ #define DASD_STOPPED_QUIESCE 2 /* Quiesced */ @@ -731,7 +748,7 @@ void dasd_free_device(struct dasd_device *); struct dasd_block *dasd_alloc_block(void); void dasd_free_block(struct dasd_block *); -enum blk_eh_timer_return dasd_times_out(struct request *req); +enum blk_eh_timer_return dasd_times_out(struct request *req, bool reserved); void dasd_enable_device(struct dasd_device *); void dasd_set_target_state(struct dasd_device *, int);