#include <linux/module.h> #include <linux/moduleparam.h>#include <linux/sched.h>#include <linux/fs.h>#include <linux/blkdev.h>#include <linux/init.h>#include <linux/slab.h>#include <linux/blk-mq.h>#include <linux/hrtimer.h> struct nullb_cmd { struct list_head list; struct llist_node ll_list; struct call_single_data csd; struct request *rq; struct bio *bio; unsigned int tag; struct nullb_queue *nq;}; struct nullb_queue { unsigned long *tag_map; wait_queue_head_t wait; unsigned int queue_depth; struct nullb_cmd *cmds;}; struct nullb { struct list_head list; unsigned int index; struct request_queue *q; struct gendisk *disk; struct hrtimer timer; unsigned int queue_depth; spinlock_t lock; struct nullb_queue *queues; unsigned int nr_queues;}; static LIST_HEAD(nullb_list);static struct mutex lock;static int null_major;static int nullb_indexes; struct completion_queue { struct llist_head list; struct hrtimer timer;}; /* * These are per-cpu for now, they will need to be configured by the * complete_queues parameter and appropriately mapped. */static DEFINE_PER_CPU(struct completion_queue, completion_queues); enum { NULL_IRQ_NONE = 0, NULL_IRQ_SOFTIRQ = 1, NULL_IRQ_TIMER = 2, NULL_Q_BIO = 0, NULL_Q_RQ = 1, NULL_Q_MQ = 2,}; static int submit_queues;module_param(submit_queues, int, S_IRUGO);MODULE_PARM_DESC(submit_queues, "Number of submission queues"); static int home_node = NUMA_NO_NODE;module_param(home_node, int, S_IRUGO);MODULE_PARM_DESC(home_node, "Home node for the device"); static int queue_mode = NULL_Q_MQ;module_param(queue_mode, int, S_IRUGO);MODULE_PARM_DESC(use_mq, "Use blk-mq interface (0=bio,1=rq,2=multiqueue)"); static int gb = 250;module_param(gb, int, S_IRUGO);MODULE_PARM_DESC(gb, "Size in GB"); static int bs = 512;module_param(bs, int, S_IRUGO);MODULE_PARM_DESC(bs, "Block size (in bytes)"); static int nr_devices = 2;module_param(nr_devices, int, S_IRUGO);MODULE_PARM_DESC(nr_devices, "Number of devices to register"); static int irqmode = NULL_IRQ_SOFTIRQ;module_param(irqmode, int, S_IRUGO);MODULE_PARM_DESC(irqmode, "IRQ completion handler. 0-none, 1-softirq, 2-timer"); static int completion_nsec = 10000;module_param(completion_nsec, int, S_IRUGO);MODULE_PARM_DESC(completion_nsec, "Time in ns to complete a request in hardware. Default: 10,000ns"); static int hw_queue_depth = 64;module_param(hw_queue_depth, int, S_IRUGO);MODULE_PARM_DESC(hw_queue_depth, "Queue depth for each hardware queue. Default: 64"); static bool use_per_node_hctx = false;module_param(use_per_node_hctx, bool, S_IRUGO);MODULE_PARM_DESC(use_per_node_hctx, "Use per-node allocation for hardware context queues. Default: false"); static void put_tag(struct nullb_queue *nq, unsigned int tag){ clear_bit_unlock(tag, nq->tag_map); if (waitqueue_active(&nq->wait)) wake_up(&nq->wait);} static unsigned int get_tag(struct nullb_queue *nq){ unsigned int tag; do { tag = find_first_zero_bit(nq->tag_map, nq->queue_depth); if (tag >= nq->queue_depth) return -1U; } while (test_and_set_bit_lock(tag, nq->tag_map)); return tag;} static void free_cmd(struct nullb_cmd *cmd){ put_tag(cmd->nq, cmd->tag);} static struct nullb_cmd *__alloc_cmd(struct nullb_queue *nq){ struct nullb_cmd *cmd; unsigned int tag; tag = get_tag(nq); if (tag != -1U) { cmd = &nq->cmds[tag]; cmd->tag = tag; cmd->nq = nq; return cmd; } return NULL;} static struct nullb_cmd *alloc_cmd(struct nullb_queue *nq, int can_wait){ struct nullb_cmd *cmd; DEFINE_WAIT(wait); cmd = __alloc_cmd(nq); if (cmd || !can_wait) return cmd; do { prepare_to_wait(&nq->wait, &wait, TASK_UNINTERRUPTIBLE); cmd = __alloc_cmd(nq); if (cmd) break; io_schedule(); } while (1); finish_wait(&nq->wait, &wait); return cmd;} static void end_cmd(struct nullb_cmd *cmd){ if (cmd->rq) { if (queue_mode == NULL_Q_MQ) blk_mq_end_io(cmd->rq, 0); else { INIT_LIST_HEAD(&cmd->rq->queuelist); blk_end_request_all(cmd->rq, 0); } } else if (cmd->bio) bio_endio(cmd->bio, 0); if (queue_mode != NULL_Q_MQ) free_cmd(cmd);} static enum hrtimer_restart null_cmd_timer_expired(struct hrtimer *timer){ struct completion_queue *cq; struct llist_node *entry; struct nullb_cmd *cmd; cq = &per_cpu(completion_queues, smp_processor_id()); while ((entry = llist_del_all(&cq->list)) != NULL) { do { cmd = container_of(entry, struct nullb_cmd, ll_list); end_cmd(cmd); entry = entry->next; } while (entry); } return HRTIMER_NORESTART;} static void null_cmd_end_timer(struct nullb_cmd *cmd){ struct completion_queue *cq = &per_cpu(completion_queues, get_cpu()); cmd->ll_list.next = NULL; if (llist_add(&cmd->ll_list, &cq->list)) { ktime_t kt = ktime_set(0, completion_nsec); hrtimer_start(&cq->timer, kt, HRTIMER_MODE_REL); } put_cpu();} static void null_softirq_done_fn(struct request *rq){ blk_end_request_all(rq, 0);} #ifdef CONFIG_SMP static void null_ipi_cmd_end_io(void *data){ struct completion_queue *cq; struct llist_node *entry, *next; struct nullb_cmd *cmd; cq = &per_cpu(completion_queues, smp_processor_id()); entry = llist_del_all(&cq->list); while (entry) { next = entry->next; cmd = llist_entry(entry, struct nullb_cmd, ll_list); end_cmd(cmd); entry = next; }} static void null_cmd_end_ipi(struct nullb_cmd *cmd){ struct call_single_data *data = &cmd->csd; int cpu = get_cpu(); struct completion_queue *cq = &per_cpu(completion_queues, cpu); cmd->ll_list.next = NULL; if (llist_add(&cmd->ll_list, &cq->list)) { data->func = null_ipi_cmd_end_io; data->flags = 0; __smp_call_function_single(cpu, data, 0); } put_cpu();} #endif /* CONFIG_SMP */ static inline void null_handle_cmd(struct nullb_cmd *cmd){ /* Complete IO by inline, softirq or timer */ switch (irqmode) { case NULL_IRQ_NONE: end_cmd(cmd); break; case NULL_IRQ_SOFTIRQ:#ifdef CONFIG_SMP null_cmd_end_ipi(cmd);#else end_cmd(cmd);#endif break; case NULL_IRQ_TIMER: null_cmd_end_timer(cmd); break; }} static struct nullb_queue *nullb_to_queue(struct nullb *nullb){ int index = 0; if (nullb->nr_queues != 1) index = raw_smp_processor_id() / ((nr_cpu_ids + nullb->nr_queues - 1) / nullb->nr_queues); return &nullb->queues[index];} static void null_queue_bio(struct request_queue *q, struct bio *bio){ struct nullb *nullb = q->queuedata; struct nullb_queue *nq = nullb_to_queue(nullb); struct nullb_cmd *cmd; cmd = alloc_cmd(nq, 1); cmd->bio = bio; null_handle_cmd(cmd);} static int null_rq_prep_fn(struct request_queue *q, struct request *req){ struct nullb *nullb = q->queuedata; struct nullb_queue *nq = nullb_to_queue(nullb); struct nullb_cmd *cmd; cmd = alloc_cmd(nq, 0); if (cmd) { cmd->rq = req; req->special = cmd; return BLKPREP_OK; } return BLKPREP_DEFER;} static void null_request_fn(struct request_queue *q){ struct request *rq; while ((rq = blk_fetch_request(q)) != NULL) { struct nullb_cmd *cmd = rq->special; spin_unlock_irq(q->queue_lock); null_handle_cmd(cmd); spin_lock_irq(q->queue_lock); }} static int null_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *rq){ struct nullb_cmd *cmd = rq->special; cmd->rq = rq; cmd->nq = hctx->driver_data; null_handle_cmd(cmd); return BLK_MQ_RQ_QUEUE_OK;} static struct blk_mq_hw_ctx *null_alloc_hctx(struct blk_mq_reg *reg, unsigned int hctx_index){ int b_size = DIV_ROUND_UP(reg->nr_hw_queues, nr_online_nodes); int tip = (reg->nr_hw_queues % nr_online_nodes); int node = 0, i, n; /* * Split submit queues evenly wrt to the number of nodes. If uneven, * fill the first buckets with one extra, until the rest is filled with * no extra. */ for (i = 0, n = 1; i < hctx_index; i++, n++) { if (n % b_size == 0) { n = 0; node++; tip--; if (!tip) b_size = reg->nr_hw_queues / nr_online_nodes; } } /* * A node might not be online, therefore map the relative node id to the * real node id. */ for_each_online_node(n) { if (!node) break; node--; } return kzalloc_node(sizeof(struct blk_mq_hw_ctx), GFP_KERNEL, n);} static void null_free_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_index){ kfree(hctx);} static void null_init_queue(struct nullb *nullb, struct nullb_queue *nq){ BUG_ON(!nullb); BUG_ON(!nq); init_waitqueue_head(&nq->wait); nq->queue_depth = nullb->queue_depth;} static int null_init_hctx(struct blk_mq_hw_ctx *hctx, void *data, unsigned int index){ struct nullb *nullb = data; struct nullb_queue *nq = &nullb->queues[index]; hctx->driver_data = nq; null_init_queue(nullb, nq); nullb->nr_queues++; return 0;} static struct blk_mq_ops null_mq_ops = { .queue_rq = null_queue_rq, .map_queue = blk_mq_map_queue, .init_hctx = null_init_hctx,}; static struct blk_mq_reg null_mq_reg = { .ops = &null_mq_ops, .queue_depth = 64, .cmd_size = sizeof(struct nullb_cmd), .flags = BLK_MQ_F_SHOULD_MERGE,}; static void null_del_dev(struct nullb *nullb){ list_del_init(&nullb->list); del_gendisk(nullb->disk); blk_cleanup_queue(nullb->q); put_disk(nullb->disk); kfree(nullb);} static int null_open(struct block_device *bdev, fmode_t mode){ return 0;} static void null_release(struct gendisk *disk, fmode_t mode){} static const struct block_device_operations null_fops = { .owner = THIS_MODULE, .open = null_open, .release = null_release,}; static int setup_commands(struct nullb_queue *nq){ struct nullb_cmd *cmd; int i, tag_size; nq->cmds = kzalloc(nq->queue_depth * sizeof(*cmd), GFP_KERNEL); if (!nq->cmds) return -ENOMEM; tag_size = ALIGN(nq->queue_depth, BITS_PER_LONG) / BITS_PER_LONG; nq->tag_map = kzalloc(tag_size * sizeof(unsigned long), GFP_KERNEL); if (!nq->tag_map) { kfree(nq->cmds); return -ENOMEM; } for (i = 0; i < nq->queue_depth; i++) { cmd = &nq->cmds[i]; INIT_LIST_HEAD(&cmd->list); cmd->ll_list.next = NULL; cmd->tag = -1U; } return 0;} static void cleanup_queue(struct nullb_queue *nq){ kfree(nq->tag_map); kfree(nq->cmds);} static void cleanup_queues(struct nullb *nullb){ int i; for (i = 0; i < nullb->nr_queues; i++) cleanup_queue(&nullb->queues[i]); kfree(nullb->queues);} static int setup_queues(struct nullb *nullb){ nullb->queues = kzalloc(submit_queues * sizeof(struct nullb_queue), GFP_KERNEL); if (!nullb->queues) return -ENOMEM; nullb->nr_queues = 0; nullb->queue_depth = hw_queue_depth; return 0;Lines 1–500 of 679. 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#include <linux/module.h> #include <linux/moduleparam.h> #include <linux/sched.h> #include <linux/fs.h> #include <linux/blkdev.h> #include <linux/init.h> #include <linux/slab.h> #include <linux/blk-mq.h> #include <linux/hrtimer.h> struct nullb_cmd { struct list_head list; struct llist_node ll_list; struct call_single_data csd; struct request *rq; struct bio *bio; unsigned int tag; struct nullb_queue *nq; }; struct nullb_queue { unsigned long *tag_map; wait_queue_head_t wait; unsigned int queue_depth; struct nullb_cmd *cmds; }; struct nullb { struct list_head list; unsigned int index; struct request_queue *q; struct gendisk *disk; struct hrtimer timer; unsigned int queue_depth; spinlock_t lock; struct nullb_queue *queues; unsigned int nr_queues; }; static LIST_HEAD(nullb_list); static struct mutex lock; static int null_major; static int nullb_indexes; struct completion_queue { struct llist_head list; struct hrtimer timer; }; /* * These are per-cpu for now, they will need to be configured by the * complete_queues parameter and appropriately mapped. */ static DEFINE_PER_CPU(struct completion_queue, completion_queues); enum { NULL_IRQ_NONE = 0, NULL_IRQ_SOFTIRQ = 1, NULL_IRQ_TIMER = 2, NULL_Q_BIO = 0, NULL_Q_RQ = 1, NULL_Q_MQ = 2, }; static int submit_queues; module_param(submit_queues, int, S_IRUGO); MODULE_PARM_DESC(submit_queues, "Number of submission queues"); static int home_node = NUMA_NO_NODE; module_param(home_node, int, S_IRUGO); MODULE_PARM_DESC(home_node, "Home node for the device"); static int queue_mode = NULL_Q_MQ; module_param(queue_mode, int, S_IRUGO); MODULE_PARM_DESC(use_mq, "Use blk-mq interface (0=bio,1=rq,2=multiqueue)"); static int gb = 250; module_param(gb, int, S_IRUGO); MODULE_PARM_DESC(gb, "Size in GB"); static int bs = 512; module_param(bs, int, S_IRUGO); MODULE_PARM_DESC(bs, "Block size (in bytes)"); static int nr_devices = 2; module_param(nr_devices, int, S_IRUGO); MODULE_PARM_DESC(nr_devices, "Number of devices to register"); static int irqmode = NULL_IRQ_SOFTIRQ; module_param(irqmode, int, S_IRUGO); MODULE_PARM_DESC(irqmode, "IRQ completion handler. 0-none, 1-softirq, 2-timer"); static int completion_nsec = 10000; module_param(completion_nsec, int, S_IRUGO); MODULE_PARM_DESC(completion_nsec, "Time in ns to complete a request in hardware. Default: 10,000ns"); static int hw_queue_depth = 64; module_param(hw_queue_depth, int, S_IRUGO); MODULE_PARM_DESC(hw_queue_depth, "Queue depth for each hardware queue. Default: 64"); static bool use_per_node_hctx = false; module_param(use_per_node_hctx, bool, S_IRUGO); MODULE_PARM_DESC(use_per_node_hctx, "Use per-node allocation for hardware context queues. Default: false"); static void put_tag(struct nullb_queue *nq, unsigned int tag) { clear_bit_unlock(tag, nq->tag_map); if (waitqueue_active(&nq->wait)) wake_up(&nq->wait); } static unsigned int get_tag(struct nullb_queue *nq) { unsigned int tag; do { tag = find_first_zero_bit(nq->tag_map, nq->queue_depth); if (tag >= nq->queue_depth) return -1U; } while (test_and_set_bit_lock(tag, nq->tag_map)); return tag; } static void free_cmd(struct nullb_cmd *cmd) { put_tag(cmd->nq, cmd->tag); } static struct nullb_cmd *__alloc_cmd(struct nullb_queue *nq) { struct nullb_cmd *cmd; unsigned int tag; tag = get_tag(nq); if (tag != -1U) { cmd = &nq->cmds[tag]; cmd->tag = tag; cmd->nq = nq; return cmd; } return NULL; } static struct nullb_cmd *alloc_cmd(struct nullb_queue *nq, int can_wait) { struct nullb_cmd *cmd; DEFINE_WAIT(wait); cmd = __alloc_cmd(nq); if (cmd || !can_wait) return cmd; do { prepare_to_wait(&nq->wait, &wait, TASK_UNINTERRUPTIBLE); cmd = __alloc_cmd(nq); if (cmd) break; io_schedule(); } while (1); finish_wait(&nq->wait, &wait); return cmd; } static void end_cmd(struct nullb_cmd *cmd) { if (cmd->rq) { if (queue_mode == NULL_Q_MQ) blk_mq_end_io(cmd->rq, 0); else { INIT_LIST_HEAD(&cmd->rq->queuelist); blk_end_request_all(cmd->rq, 0); } } else if (cmd->bio) bio_endio(cmd->bio, 0); if (queue_mode != NULL_Q_MQ) free_cmd(cmd); } static enum hrtimer_restart null_cmd_timer_expired(struct hrtimer *timer) { struct completion_queue *cq; struct llist_node *entry; struct nullb_cmd *cmd; cq = &per_cpu(completion_queues, smp_processor_id()); while ((entry = llist_del_all(&cq->list)) != NULL) { do { cmd = container_of(entry, struct nullb_cmd, ll_list); end_cmd(cmd); entry = entry->next; } while (entry); } return HRTIMER_NORESTART; } static void null_cmd_end_timer(struct nullb_cmd *cmd) { struct completion_queue *cq = &per_cpu(completion_queues, get_cpu()); cmd->ll_list.next = NULL; if (llist_add(&cmd->ll_list, &cq->list)) { ktime_t kt = ktime_set(0, completion_nsec); hrtimer_start(&cq->timer, kt, HRTIMER_MODE_REL); } put_cpu(); } static void null_softirq_done_fn(struct request *rq) { blk_end_request_all(rq, 0); } #ifdef CONFIG_SMP static void null_ipi_cmd_end_io(void *data) { struct completion_queue *cq; struct llist_node *entry, *next; struct nullb_cmd *cmd; cq = &per_cpu(completion_queues, smp_processor_id()); entry = llist_del_all(&cq->list); while (entry) { next = entry->next; cmd = llist_entry(entry, struct nullb_cmd, ll_list); end_cmd(cmd); entry = next; } } static void null_cmd_end_ipi(struct nullb_cmd *cmd) { struct call_single_data *data = &cmd->csd; int cpu = get_cpu(); struct completion_queue *cq = &per_cpu(completion_queues, cpu); cmd->ll_list.next = NULL; if (llist_add(&cmd->ll_list, &cq->list)) { data->func = null_ipi_cmd_end_io; data->flags = 0; __smp_call_function_single(cpu, data, 0); } put_cpu(); } #endif /* CONFIG_SMP */ static inline void null_handle_cmd(struct nullb_cmd *cmd) { /* Complete IO by inline, softirq or timer */ switch (irqmode) { case NULL_IRQ_NONE: end_cmd(cmd); break; case NULL_IRQ_SOFTIRQ: #ifdef CONFIG_SMP null_cmd_end_ipi(cmd); #else end_cmd(cmd); #endif break; case NULL_IRQ_TIMER: null_cmd_end_timer(cmd); break; } } static struct nullb_queue *nullb_to_queue(struct nullb *nullb) { int index = 0; if (nullb->nr_queues != 1) index = raw_smp_processor_id() / ((nr_cpu_ids + nullb->nr_queues - 1) / nullb->nr_queues); return &nullb->queues[index]; } static void null_queue_bio(struct request_queue *q, struct bio *bio) { struct nullb *nullb = q->queuedata; struct nullb_queue *nq = nullb_to_queue(nullb); struct nullb_cmd *cmd; cmd = alloc_cmd(nq, 1); cmd->bio = bio; null_handle_cmd(cmd); } static int null_rq_prep_fn(struct request_queue *q, struct request *req) { struct nullb *nullb = q->queuedata; struct nullb_queue *nq = nullb_to_queue(nullb); struct nullb_cmd *cmd; cmd = alloc_cmd(nq, 0); if (cmd) { cmd->rq = req; req->special = cmd; return BLKPREP_OK; } return BLKPREP_DEFER; } static void null_request_fn(struct request_queue *q) { struct request *rq; while ((rq = blk_fetch_request(q)) != NULL) { struct nullb_cmd *cmd = rq->special; spin_unlock_irq(q->queue_lock); null_handle_cmd(cmd); spin_lock_irq(q->queue_lock); } } static int null_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *rq) { struct nullb_cmd *cmd = rq->special; cmd->rq = rq; cmd->nq = hctx->driver_data; null_handle_cmd(cmd); return BLK_MQ_RQ_QUEUE_OK; } static struct blk_mq_hw_ctx *null_alloc_hctx(struct blk_mq_reg *reg, unsigned int hctx_index) { int b_size = DIV_ROUND_UP(reg->nr_hw_queues, nr_online_nodes); int tip = (reg->nr_hw_queues % nr_online_nodes); int node = 0, i, n; /* * Split submit queues evenly wrt to the number of nodes. If uneven, * fill the first buckets with one extra, until the rest is filled with * no extra. */ for (i = 0, n = 1; i < hctx_index; i++, n++) { if (n % b_size == 0) { n = 0; node++; tip--; if (!tip) b_size = reg->nr_hw_queues / nr_online_nodes; } } /* * A node might not be online, therefore map the relative node id to the * real node id. */ for_each_online_node(n) { if (!node) break; node--; } return kzalloc_node(sizeof(struct blk_mq_hw_ctx), GFP_KERNEL, n); } static void null_free_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_index) { kfree(hctx); } static void null_init_queue(struct nullb *nullb, struct nullb_queue *nq) { BUG_ON(!nullb); BUG_ON(!nq); init_waitqueue_head(&nq->wait); nq->queue_depth = nullb->queue_depth; } static int null_init_hctx(struct blk_mq_hw_ctx *hctx, void *data, unsigned int index) { struct nullb *nullb = data; struct nullb_queue *nq = &nullb->queues[index]; hctx->driver_data = nq; null_init_queue(nullb, nq); nullb->nr_queues++; return 0; } static struct blk_mq_ops null_mq_ops = { .queue_rq = null_queue_rq, .map_queue = blk_mq_map_queue, .init_hctx = null_init_hctx, }; static struct blk_mq_reg null_mq_reg = { .ops = &null_mq_ops, .queue_depth = 64, .cmd_size = sizeof(struct nullb_cmd), .flags = BLK_MQ_F_SHOULD_MERGE, }; static void null_del_dev(struct nullb *nullb) { list_del_init(&nullb->list); del_gendisk(nullb->disk); blk_cleanup_queue(nullb->q); put_disk(nullb->disk); kfree(nullb); } static int null_open(struct block_device *bdev, fmode_t mode) { return 0; } static void null_release(struct gendisk *disk, fmode_t mode) { } static const struct block_device_operations null_fops = { .owner = THIS_MODULE, .open = null_open, .release = null_release, }; static int setup_commands(struct nullb_queue *nq) { struct nullb_cmd *cmd; int i, tag_size; nq->cmds = kzalloc(nq->queue_depth * sizeof(*cmd), GFP_KERNEL); if (!nq->cmds) return -ENOMEM; tag_size = ALIGN(nq->queue_depth, BITS_PER_LONG) / BITS_PER_LONG; nq->tag_map = kzalloc(tag_size * sizeof(unsigned long), GFP_KERNEL); if (!nq->tag_map) { kfree(nq->cmds); return -ENOMEM; } for (i = 0; i < nq->queue_depth; i++) { cmd = &nq->cmds[i]; INIT_LIST_HEAD(&cmd->list); cmd->ll_list.next = NULL; cmd->tag = -1U; } return 0; } static void cleanup_queue(struct nullb_queue *nq) { kfree(nq->tag_map); kfree(nq->cmds); } static void cleanup_queues(struct nullb *nullb) { int i; for (i = 0; i < nullb->nr_queues; i++) cleanup_queue(&nullb->queues[i]); kfree(nullb->queues); } static int setup_queues(struct nullb *nullb) { nullb->queues = kzalloc(submit_queues * sizeof(struct nullb_queue), GFP_KERNEL); if (!nullb->queues) return -ENOMEM; nullb->nr_queues = 0; nullb->queue_depth = hw_queue_depth; return 0;