blk-mq: split out tag initialization, support shared tags
authorChristoph Hellwig <hch@lst.de>
Tue, 15 Apr 2014 20:14:00 +0000 (14:14 -0600)
committerJens Axboe <axboe@fb.com>
Tue, 15 Apr 2014 20:18:02 +0000 (14:18 -0600)
Add a new blk_mq_tag_set structure that gets set up before we initialize
the queue.  A single blk_mq_tag_set structure can be shared by multiple
queues.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Modular export of blk_mq_{alloc,free}_tagset added by me.

Signed-off-by: Jens Axboe <axboe@fb.com>
block/blk-mq-cpumap.c
block/blk-mq-tag.c
block/blk-mq-tag.h
block/blk-mq.c
block/blk-mq.h
drivers/block/null_blk.c
drivers/block/virtio_blk.c
include/linux/blk-mq.h

index 09792132961991e8168c2dee283a7b0cb0b967d0..5d0f93cf358cdef9b782fdc4dbf442daf11781bf 100644 (file)
@@ -80,17 +80,17 @@ int blk_mq_update_queue_map(unsigned int *map, unsigned int nr_queues)
        return 0;
 }
 
-unsigned int *blk_mq_make_queue_map(struct blk_mq_reg *reg)
+unsigned int *blk_mq_make_queue_map(struct blk_mq_tag_set *set)
 {
        unsigned int *map;
 
        /* If cpus are offline, map them to first hctx */
        map = kzalloc_node(sizeof(*map) * num_possible_cpus(), GFP_KERNEL,
-                               reg->numa_node);
+                               set->numa_node);
        if (!map)
                return NULL;
 
-       if (!blk_mq_update_queue_map(map, reg->nr_hw_queues))
+       if (!blk_mq_update_queue_map(map, set->nr_hw_queues))
                return map;
 
        kfree(map);
index 83ae96c51a2762cf7386f096e348eace58525e37..7a799c46c32d0c358fc9f912b9e0b2f0ab0fb3ee 100644 (file)
@@ -1,25 +1,11 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
-#include <linux/percpu_ida.h>
 
 #include <linux/blk-mq.h>
 #include "blk.h"
 #include "blk-mq.h"
 #include "blk-mq-tag.h"
 
-/*
- * Per tagged queue (tag address space) map
- */
-struct blk_mq_tags {
-       unsigned int nr_tags;
-       unsigned int nr_reserved_tags;
-       unsigned int nr_batch_move;
-       unsigned int nr_max_cache;
-
-       struct percpu_ida free_tags;
-       struct percpu_ida reserved_tags;
-};
-
 void blk_mq_wait_for_tags(struct blk_mq_tags *tags)
 {
        int tag = blk_mq_get_tag(tags, __GFP_WAIT, false);
index 947ba2c6148e0b24e53ecaf9eceb7efff15472d0..b602e3fa66ea0ad5aad11dd99dbb53bb681ec223 100644 (file)
@@ -1,7 +1,24 @@
 #ifndef INT_BLK_MQ_TAG_H
 #define INT_BLK_MQ_TAG_H
 
-struct blk_mq_tags;
+#include <linux/percpu_ida.h>
+
+/*
+ * Tag address space map.
+ */
+struct blk_mq_tags {
+       unsigned int nr_tags;
+       unsigned int nr_reserved_tags;
+       unsigned int nr_batch_move;
+       unsigned int nr_max_cache;
+
+       struct percpu_ida free_tags;
+       struct percpu_ida reserved_tags;
+
+       struct request **rqs;
+       struct list_head page_list;
+};
+
 
 extern struct blk_mq_tags *blk_mq_init_tags(unsigned int nr_tags, unsigned int reserved_tags, int node);
 extern void blk_mq_free_tags(struct blk_mq_tags *tags);
index 2a5a0fed10a33dcaf8095ee668ac69a58d5e21dc..9180052d42cc13ed476471350e2f7934b8b2f006 100644 (file)
@@ -81,7 +81,7 @@ static struct request *__blk_mq_alloc_request(struct blk_mq_hw_ctx *hctx,
 
        tag = blk_mq_get_tag(hctx->tags, gfp, reserved);
        if (tag != BLK_MQ_TAG_FAIL) {
-               rq = hctx->rqs[tag];
+               rq = hctx->tags->rqs[tag];
                blk_rq_init(hctx->queue, rq);
                rq->tag = tag;
 
@@ -404,6 +404,12 @@ static void blk_mq_requeue_request(struct request *rq)
                rq->nr_phys_segments--;
 }
 
+struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag)
+{
+       return tags->rqs[tag];
+}
+EXPORT_SYMBOL(blk_mq_tag_to_rq);
+
 struct blk_mq_timeout_data {
        struct blk_mq_hw_ctx *hctx;
        unsigned long *next;
@@ -425,12 +431,13 @@ static void blk_mq_timeout_check(void *__data, unsigned long *free_tags)
        do {
                struct request *rq;
 
-               tag = find_next_zero_bit(free_tags, hctx->queue_depth, tag);
-               if (tag >= hctx->queue_depth)
+               tag = find_next_zero_bit(free_tags, hctx->tags->nr_tags, tag);
+               if (tag >= hctx->tags->nr_tags)
                        break;
 
-               rq = hctx->rqs[tag++];
-
+               rq = blk_mq_tag_to_rq(hctx->tags, tag++);
+               if (rq->q != hctx->queue)
+                       continue;
                if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags))
                        continue;
 
@@ -969,11 +976,11 @@ struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q, const int cpu)
 }
 EXPORT_SYMBOL(blk_mq_map_queue);
 
-struct blk_mq_hw_ctx *blk_mq_alloc_single_hw_queue(struct blk_mq_reg *reg,
+struct blk_mq_hw_ctx *blk_mq_alloc_single_hw_queue(struct blk_mq_tag_set *set,
                                                   unsigned int hctx_index)
 {
        return kmalloc_node(sizeof(struct blk_mq_hw_ctx),
-                               GFP_KERNEL | __GFP_ZERO, reg->numa_node);
+                               GFP_KERNEL | __GFP_ZERO, set->numa_node);
 }
 EXPORT_SYMBOL(blk_mq_alloc_single_hw_queue);
 
@@ -1030,31 +1037,31 @@ static void blk_mq_hctx_notify(void *data, unsigned long action,
        blk_mq_put_ctx(ctx);
 }
 
-static void blk_mq_free_rq_map(struct blk_mq_hw_ctx *hctx, void *driver_data)
+static void blk_mq_free_rq_map(struct blk_mq_tag_set *set,
+               struct blk_mq_tags *tags, unsigned int hctx_idx)
 {
        struct page *page;
 
-       if (hctx->rqs && hctx->queue->mq_ops->exit_request) {
+       if (tags->rqs && set->ops->exit_request) {
                int i;
 
-               for (i = 0; i < hctx->queue_depth; i++) {
-                       if (!hctx->rqs[i])
+               for (i = 0; i < tags->nr_tags; i++) {
+                       if (!tags->rqs[i])
                                continue;
-                       hctx->queue->mq_ops->exit_request(driver_data, hctx,
-                                                         hctx->rqs[i], i);
+                       set->ops->exit_request(set->driver_data, tags->rqs[i],
+                                               hctx_idx, i);
                }
        }
 
-       while (!list_empty(&hctx->page_list)) {
-               page = list_first_entry(&hctx->page_list, struct page, lru);
+       while (!list_empty(&tags->page_list)) {
+               page = list_first_entry(&tags->page_list, struct page, lru);
                list_del_init(&page->lru);
                __free_pages(page, page->private);
        }
 
-       kfree(hctx->rqs);
+       kfree(tags->rqs);
 
-       if (hctx->tags)
-               blk_mq_free_tags(hctx->tags);
+       blk_mq_free_tags(tags);
 }
 
 static size_t order_to_size(unsigned int order)
@@ -1067,30 +1074,36 @@ static size_t order_to_size(unsigned int order)
        return ret;
 }
 
-static int blk_mq_init_rq_map(struct blk_mq_hw_ctx *hctx,
-               struct blk_mq_reg *reg, void *driver_data, int node)
+static struct blk_mq_tags *blk_mq_init_rq_map(struct blk_mq_tag_set *set,
+               unsigned int hctx_idx)
 {
-       unsigned int reserved_tags = reg->reserved_tags;
+       struct blk_mq_tags *tags;
        unsigned int i, j, entries_per_page, max_order = 4;
        size_t rq_size, left;
-       int error;
 
-       INIT_LIST_HEAD(&hctx->page_list);
+       tags = blk_mq_init_tags(set->queue_depth, set->reserved_tags,
+                               set->numa_node);
+       if (!tags)
+               return NULL;
 
-       hctx->rqs = kmalloc_node(hctx->queue_depth * sizeof(struct request *),
-                                       GFP_KERNEL, node);
-       if (!hctx->rqs)
-               return -ENOMEM;
+       INIT_LIST_HEAD(&tags->page_list);
+
+       tags->rqs = kmalloc_node(set->queue_depth * sizeof(struct request *),
+                                       GFP_KERNEL, set->numa_node);
+       if (!tags->rqs) {
+               blk_mq_free_tags(tags);
+               return NULL;
+       }
 
        /*
         * rq_size is the size of the request plus driver payload, rounded
         * to the cacheline size
         */
-       rq_size = round_up(sizeof(struct request) + hctx->cmd_size,
+       rq_size = round_up(sizeof(struct request) + set->cmd_size,
                                cache_line_size());
-       left = rq_size * hctx->queue_depth;
+       left = rq_size * set->queue_depth;
 
-       for (i = 0; i < hctx->queue_depth;) {
+       for (i = 0; i < set->queue_depth; ) {
                int this_order = max_order;
                struct page *page;
                int to_do;
@@ -1100,7 +1113,8 @@ static int blk_mq_init_rq_map(struct blk_mq_hw_ctx *hctx,
                        this_order--;
 
                do {
-                       page = alloc_pages_node(node, GFP_KERNEL, this_order);
+                       page = alloc_pages_node(set->numa_node, GFP_KERNEL,
+                                               this_order);
                        if (page)
                                break;
                        if (!this_order--)
@@ -1110,22 +1124,22 @@ static int blk_mq_init_rq_map(struct blk_mq_hw_ctx *hctx,
                } while (1);
 
                if (!page)
-                       break;
+                       goto fail;
 
                page->private = this_order;
-               list_add_tail(&page->lru, &hctx->page_list);
+               list_add_tail(&page->lru, &tags->page_list);
 
                p = page_address(page);
                entries_per_page = order_to_size(this_order) / rq_size;
-               to_do = min(entries_per_page, hctx->queue_depth - i);
+               to_do = min(entries_per_page, set->queue_depth - i);
                left -= to_do * rq_size;
                for (j = 0; j < to_do; j++) {
-                       hctx->rqs[i] = p;
-                       if (reg->ops->init_request) {
-                               error = reg->ops->init_request(driver_data,
-                                               hctx, hctx->rqs[i], i);
-                               if (error)
-                                       goto err_rq_map;
+                       tags->rqs[i] = p;
+                       if (set->ops->init_request) {
+                               if (set->ops->init_request(set->driver_data,
+                                               tags->rqs[i], hctx_idx, i,
+                                               set->numa_node))
+                                       goto fail;
                        }
 
                        p += rq_size;
@@ -1133,30 +1147,16 @@ static int blk_mq_init_rq_map(struct blk_mq_hw_ctx *hctx,
                }
        }
 
-       if (i < (reserved_tags + BLK_MQ_TAG_MIN)) {
-               error = -ENOMEM;
-               goto err_rq_map;
-       }
-       if (i != hctx->queue_depth) {
-               hctx->queue_depth = i;
-               pr_warn("%s: queue depth set to %u because of low memory\n",
-                                       __func__, i);
-       }
+       return tags;
 
-       hctx->tags = blk_mq_init_tags(hctx->queue_depth, reserved_tags, node);
-       if (!hctx->tags) {
-               error = -ENOMEM;
-               goto err_rq_map;
-       }
-
-       return 0;
-err_rq_map:
-       blk_mq_free_rq_map(hctx, driver_data);
-       return error;
+fail:
+       pr_warn("%s: failed to allocate requests\n", __func__);
+       blk_mq_free_rq_map(set, tags, hctx_idx);
+       return NULL;
 }
 
 static int blk_mq_init_hw_queues(struct request_queue *q,
-                                struct blk_mq_reg *reg, void *driver_data)
+               struct blk_mq_tag_set *set)
 {
        struct blk_mq_hw_ctx *hctx;
        unsigned int i, j;
@@ -1170,23 +1170,21 @@ static int blk_mq_init_hw_queues(struct request_queue *q,
 
                node = hctx->numa_node;
                if (node == NUMA_NO_NODE)
-                       node = hctx->numa_node = reg->numa_node;
+                       node = hctx->numa_node = set->numa_node;
 
                INIT_DELAYED_WORK(&hctx->delayed_work, blk_mq_work_fn);
                spin_lock_init(&hctx->lock);
                INIT_LIST_HEAD(&hctx->dispatch);
                hctx->queue = q;
                hctx->queue_num = i;
-               hctx->flags = reg->flags;
-               hctx->queue_depth = reg->queue_depth;
-               hctx->cmd_size = reg->cmd_size;
+               hctx->flags = set->flags;
+               hctx->cmd_size = set->cmd_size;
 
                blk_mq_init_cpu_notifier(&hctx->cpu_notifier,
                                                blk_mq_hctx_notify, hctx);
                blk_mq_register_cpu_notifier(&hctx->cpu_notifier);
 
-               if (blk_mq_init_rq_map(hctx, reg, driver_data, node))
-                       break;
+               hctx->tags = set->tags[i];
 
                /*
                 * Allocate space for all possible cpus to avoid allocation in
@@ -1206,8 +1204,8 @@ static int blk_mq_init_hw_queues(struct request_queue *q,
                hctx->nr_ctx_map = num_maps;
                hctx->nr_ctx = 0;
 
-               if (reg->ops->init_hctx &&
-                   reg->ops->init_hctx(hctx, driver_data, i))
+               if (set->ops->init_hctx &&
+                   set->ops->init_hctx(hctx, set->driver_data, i))
                        break;
        }
 
@@ -1221,11 +1219,10 @@ static int blk_mq_init_hw_queues(struct request_queue *q,
                if (i == j)
                        break;
 
-               if (reg->ops->exit_hctx)
-                       reg->ops->exit_hctx(hctx, j);
+               if (set->ops->exit_hctx)
+                       set->ops->exit_hctx(hctx, j);
 
                blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier);
-               blk_mq_free_rq_map(hctx, driver_data);
                kfree(hctx->ctxs);
        }
 
@@ -1290,41 +1287,25 @@ static void blk_mq_map_swqueue(struct request_queue *q)
        }
 }
 
-struct request_queue *blk_mq_init_queue(struct blk_mq_reg *reg,
-                                       void *driver_data)
+struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
 {
        struct blk_mq_hw_ctx **hctxs;
        struct blk_mq_ctx *ctx;
        struct request_queue *q;
        int i;
 
-       if (!reg->nr_hw_queues ||
-           !reg->ops->queue_rq || !reg->ops->map_queue ||
-           !reg->ops->alloc_hctx || !reg->ops->free_hctx)
-               return ERR_PTR(-EINVAL);
-
-       if (!reg->queue_depth)
-               reg->queue_depth = BLK_MQ_MAX_DEPTH;
-       else if (reg->queue_depth > BLK_MQ_MAX_DEPTH) {
-               pr_err("blk-mq: queuedepth too large (%u)\n", reg->queue_depth);
-               reg->queue_depth = BLK_MQ_MAX_DEPTH;
-       }
-
-       if (reg->queue_depth < (reg->reserved_tags + BLK_MQ_TAG_MIN))
-               return ERR_PTR(-EINVAL);
-
        ctx = alloc_percpu(struct blk_mq_ctx);
        if (!ctx)
                return ERR_PTR(-ENOMEM);
 
-       hctxs = kmalloc_node(reg->nr_hw_queues * sizeof(*hctxs), GFP_KERNEL,
-                       reg->numa_node);
+       hctxs = kmalloc_node(set->nr_hw_queues * sizeof(*hctxs), GFP_KERNEL,
+                       set->numa_node);
 
        if (!hctxs)
                goto err_percpu;
 
-       for (i = 0; i < reg->nr_hw_queues; i++) {
-               hctxs[i] = reg->ops->alloc_hctx(reg, i);
+       for (i = 0; i < set->nr_hw_queues; i++) {
+               hctxs[i] = set->ops->alloc_hctx(set, i);
                if (!hctxs[i])
                        goto err_hctxs;
 
@@ -1335,11 +1316,11 @@ struct request_queue *blk_mq_init_queue(struct blk_mq_reg *reg,
                hctxs[i]->queue_num = i;
        }
 
-       q = blk_alloc_queue_node(GFP_KERNEL, reg->numa_node);
+       q = blk_alloc_queue_node(GFP_KERNEL, set->numa_node);
        if (!q)
                goto err_hctxs;
 
-       q->mq_map = blk_mq_make_queue_map(reg);
+       q->mq_map = blk_mq_make_queue_map(set);
        if (!q->mq_map)
                goto err_map;
 
@@ -1347,33 +1328,34 @@ struct request_queue *blk_mq_init_queue(struct blk_mq_reg *reg,
        blk_queue_rq_timeout(q, 30000);
 
        q->nr_queues = nr_cpu_ids;
-       q->nr_hw_queues = reg->nr_hw_queues;
+       q->nr_hw_queues = set->nr_hw_queues;
 
        q->queue_ctx = ctx;
        q->queue_hw_ctx = hctxs;
 
-       q->mq_ops = reg->ops;
+       q->mq_ops = set->ops;
        q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT;
 
        q->sg_reserved_size = INT_MAX;
 
        blk_queue_make_request(q, blk_mq_make_request);
-       blk_queue_rq_timed_out(q, reg->ops->timeout);
-       if (reg->timeout)
-               blk_queue_rq_timeout(q, reg->timeout);
+       blk_queue_rq_timed_out(q, set->ops->timeout);
+       if (set->timeout)
+               blk_queue_rq_timeout(q, set->timeout);
 
-       if (reg->ops->complete)
-               blk_queue_softirq_done(q, reg->ops->complete);
+       if (set->ops->complete)
+               blk_queue_softirq_done(q, set->ops->complete);
 
        blk_mq_init_flush(q);
-       blk_mq_init_cpu_queues(q, reg->nr_hw_queues);
+       blk_mq_init_cpu_queues(q, set->nr_hw_queues);
 
-       q->flush_rq = kzalloc(round_up(sizeof(struct request) + reg->cmd_size,
-                               cache_line_size()), GFP_KERNEL);
+       q->flush_rq = kzalloc(round_up(sizeof(struct request) +
+                               set->cmd_size, cache_line_size()),
+                               GFP_KERNEL);
        if (!q->flush_rq)
                goto err_hw;
 
-       if (blk_mq_init_hw_queues(q, reg, driver_data))
+       if (blk_mq_init_hw_queues(q, set))
                goto err_flush_rq;
 
        blk_mq_map_swqueue(q);
@@ -1391,11 +1373,11 @@ err_hw:
 err_map:
        blk_cleanup_queue(q);
 err_hctxs:
-       for (i = 0; i < reg->nr_hw_queues; i++) {
+       for (i = 0; i < set->nr_hw_queues; i++) {
                if (!hctxs[i])
                        break;
                free_cpumask_var(hctxs[i]->cpumask);
-               reg->ops->free_hctx(hctxs[i], i);
+               set->ops->free_hctx(hctxs[i], i);
        }
        kfree(hctxs);
 err_percpu:
@@ -1412,7 +1394,6 @@ void blk_mq_free_queue(struct request_queue *q)
        queue_for_each_hw_ctx(q, hctx, i) {
                kfree(hctx->ctx_map);
                kfree(hctx->ctxs);
-               blk_mq_free_rq_map(hctx, q->queuedata);
                blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier);
                if (q->mq_ops->exit_hctx)
                        q->mq_ops->exit_hctx(hctx, i);
@@ -1473,6 +1454,53 @@ static int blk_mq_queue_reinit_notify(struct notifier_block *nb,
        return NOTIFY_OK;
 }
 
+int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set)
+{
+       int i;
+
+       if (!set->nr_hw_queues)
+               return -EINVAL;
+       if (!set->queue_depth || set->queue_depth > BLK_MQ_MAX_DEPTH)
+               return -EINVAL;
+       if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN)
+               return -EINVAL;
+
+       if (!set->nr_hw_queues ||
+           !set->ops->queue_rq || !set->ops->map_queue ||
+           !set->ops->alloc_hctx || !set->ops->free_hctx)
+               return -EINVAL;
+
+
+       set->tags = kmalloc_node(set->nr_hw_queues * sizeof(struct blk_mq_tags),
+                                GFP_KERNEL, set->numa_node);
+       if (!set->tags)
+               goto out;
+
+       for (i = 0; i < set->nr_hw_queues; i++) {
+               set->tags[i] = blk_mq_init_rq_map(set, i);
+               if (!set->tags[i])
+                       goto out_unwind;
+       }
+
+       return 0;
+
+out_unwind:
+       while (--i >= 0)
+               blk_mq_free_rq_map(set, set->tags[i], i);
+out:
+       return -ENOMEM;
+}
+EXPORT_SYMBOL(blk_mq_alloc_tag_set);
+
+void blk_mq_free_tag_set(struct blk_mq_tag_set *set)
+{
+       int i;
+
+       for (i = 0; i < set->nr_hw_queues; i++)
+               blk_mq_free_rq_map(set, set->tags[i], i);
+}
+EXPORT_SYMBOL(blk_mq_free_tag_set);
+
 void blk_mq_disable_hotplug(void)
 {
        mutex_lock(&all_q_mutex);
index 7964dadb7d64b1b2ae4e308eedf36479fce7fbe1..5fa14f19f7524edc585e35965675b97375c10d76 100644 (file)
@@ -1,6 +1,8 @@
 #ifndef INT_BLK_MQ_H
 #define INT_BLK_MQ_H
 
+struct blk_mq_tag_set;
+
 struct blk_mq_ctx {
        struct {
                spinlock_t              lock;
@@ -46,8 +48,7 @@ void blk_mq_disable_hotplug(void);
 /*
  * CPU -> queue mappings
  */
-struct blk_mq_reg;
-extern unsigned int *blk_mq_make_queue_map(struct blk_mq_reg *reg);
+extern unsigned int *blk_mq_make_queue_map(struct blk_mq_tag_set *set);
 extern int blk_mq_update_queue_map(unsigned int *map, unsigned int nr_queues);
 
 void blk_mq_add_timer(struct request *rq);
index 71df69d90900623586bd0962e5ad5df3a7ccd310..8e7e3a0b0d24834ed46e6cd5c3f47c444b016733 100644 (file)
@@ -32,6 +32,7 @@ struct nullb {
        unsigned int index;
        struct request_queue *q;
        struct gendisk *disk;
+       struct blk_mq_tag_set tag_set;
        struct hrtimer timer;
        unsigned int queue_depth;
        spinlock_t lock;
@@ -320,10 +321,11 @@ static int null_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *rq)
        return BLK_MQ_RQ_QUEUE_OK;
 }
 
-static struct blk_mq_hw_ctx *null_alloc_hctx(struct blk_mq_reg *reg, unsigned int hctx_index)
+static struct blk_mq_hw_ctx *null_alloc_hctx(struct blk_mq_tag_set *set,
+               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 b_size = DIV_ROUND_UP(set->nr_hw_queues, nr_online_nodes);
+       int tip = (set->nr_hw_queues % nr_online_nodes);
        int node = 0, i, n;
 
        /*
@@ -338,7 +340,7 @@ static struct blk_mq_hw_ctx *null_alloc_hctx(struct blk_mq_reg *reg, unsigned in
 
                        tip--;
                        if (!tip)
-                               b_size = reg->nr_hw_queues / nr_online_nodes;
+                               b_size = set->nr_hw_queues / nr_online_nodes;
                }
        }
 
@@ -387,13 +389,17 @@ static struct blk_mq_ops null_mq_ops = {
        .map_queue      = blk_mq_map_queue,
        .init_hctx      = null_init_hctx,
        .complete       = null_softirq_done_fn,
+       .alloc_hctx     = blk_mq_alloc_single_hw_queue,
+       .free_hctx      = blk_mq_free_single_hw_queue,
 };
 
-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 struct blk_mq_ops null_mq_ops_pernode = {
+       .queue_rq       = null_queue_rq,
+       .map_queue      = blk_mq_map_queue,
+       .init_hctx      = null_init_hctx,
+       .complete       = null_softirq_done_fn,
+       .alloc_hctx     = null_alloc_hctx,
+       .free_hctx      = null_free_hctx,
 };
 
 static void null_del_dev(struct nullb *nullb)
@@ -402,6 +408,8 @@ static void null_del_dev(struct nullb *nullb)
 
        del_gendisk(nullb->disk);
        blk_cleanup_queue(nullb->q);
+       if (queue_mode == NULL_Q_MQ)
+               blk_mq_free_tag_set(&nullb->tag_set);
        put_disk(nullb->disk);
        kfree(nullb);
 }
@@ -506,7 +514,7 @@ static int null_add_dev(void)
 
        nullb = kzalloc_node(sizeof(*nullb), GFP_KERNEL, home_node);
        if (!nullb)
-               return -ENOMEM;
+               goto out;
 
        spin_lock_init(&nullb->lock);
 
@@ -514,49 +522,47 @@ static int null_add_dev(void)
                submit_queues = nr_online_nodes;
 
        if (setup_queues(nullb))
-               goto err;
+               goto out_free_nullb;
 
        if (queue_mode == NULL_Q_MQ) {
-               null_mq_reg.numa_node = home_node;
-               null_mq_reg.queue_depth = hw_queue_depth;
-               null_mq_reg.nr_hw_queues = submit_queues;
-
-               if (use_per_node_hctx) {
-                       null_mq_reg.ops->alloc_hctx = null_alloc_hctx;
-                       null_mq_reg.ops->free_hctx = null_free_hctx;
-               } else {
-                       null_mq_reg.ops->alloc_hctx = blk_mq_alloc_single_hw_queue;
-                       null_mq_reg.ops->free_hctx = blk_mq_free_single_hw_queue;
-               }
-
-               nullb->q = blk_mq_init_queue(&null_mq_reg, nullb);
+               if (use_per_node_hctx)
+                       nullb->tag_set.ops = &null_mq_ops_pernode;
+               else
+                       nullb->tag_set.ops = &null_mq_ops;
+               nullb->tag_set.nr_hw_queues = submit_queues;
+               nullb->tag_set.queue_depth = hw_queue_depth;
+               nullb->tag_set.numa_node = home_node;
+               nullb->tag_set.cmd_size = sizeof(struct nullb_cmd);
+               nullb->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
+               nullb->tag_set.driver_data = nullb;
+
+               if (blk_mq_alloc_tag_set(&nullb->tag_set))
+                       goto out_cleanup_queues;
+
+               nullb->q = blk_mq_init_queue(&nullb->tag_set);
+               if (!nullb->q)
+                       goto out_cleanup_tags;
        } else if (queue_mode == NULL_Q_BIO) {
                nullb->q = blk_alloc_queue_node(GFP_KERNEL, home_node);
+               if (!nullb->q)
+                       goto out_cleanup_queues;
                blk_queue_make_request(nullb->q, null_queue_bio);
                init_driver_queues(nullb);
        } else {
                nullb->q = blk_init_queue_node(null_request_fn, &nullb->lock, home_node);
+               if (!nullb->q)
+                       goto out_cleanup_queues;
                blk_queue_prep_rq(nullb->q, null_rq_prep_fn);
-               if (nullb->q)
-                       blk_queue_softirq_done(nullb->q, null_softirq_done_fn);
+               blk_queue_softirq_done(nullb->q, null_softirq_done_fn);
                init_driver_queues(nullb);
        }
 
-       if (!nullb->q)
-               goto queue_fail;
-
        nullb->q->queuedata = nullb;
        queue_flag_set_unlocked(QUEUE_FLAG_NONROT, nullb->q);
 
        disk = nullb->disk = alloc_disk_node(1, home_node);
-       if (!disk) {
-queue_fail:
-               blk_cleanup_queue(nullb->q);
-               cleanup_queues(nullb);
-err:
-               kfree(nullb);
-               return -ENOMEM;
-       }
+       if (!disk)
+               goto out_cleanup_blk_queue;
 
        mutex_lock(&lock);
        list_add_tail(&nullb->list, &nullb_list);
@@ -579,6 +585,18 @@ err:
        sprintf(disk->disk_name, "nullb%d", nullb->index);
        add_disk(disk);
        return 0;
+
+out_cleanup_blk_queue:
+       blk_cleanup_queue(nullb->q);
+out_cleanup_tags:
+       if (queue_mode == NULL_Q_MQ)
+               blk_mq_free_tag_set(&nullb->tag_set);
+out_cleanup_queues:
+       cleanup_queues(nullb);
+out_free_nullb:
+       kfree(nullb);
+out:
+       return -ENOMEM;
 }
 
 static int __init null_init(void)
index d06206abd340e27f302b423a9c788f322d078def..f909a8821e65786eb8148629fa33eb299bd28bf6 100644 (file)
@@ -30,6 +30,9 @@ struct virtio_blk
        /* The disk structure for the kernel. */
        struct gendisk *disk;
 
+       /* Block layer tags. */
+       struct blk_mq_tag_set tag_set;
+
        /* Process context for config space updates */
        struct work_struct config_work;
 
@@ -480,8 +483,9 @@ static const struct device_attribute dev_attr_cache_type_rw =
        __ATTR(cache_type, S_IRUGO|S_IWUSR,
               virtblk_cache_type_show, virtblk_cache_type_store);
 
-static int virtblk_init_request(void *data, struct blk_mq_hw_ctx *hctx,
-               struct request *rq, unsigned int nr)
+static int virtblk_init_request(void *data, struct request *rq,
+               unsigned int hctx_idx, unsigned int request_idx,
+               unsigned int numa_node)
 {
        struct virtio_blk *vblk = data;
        struct virtblk_req *vbr = blk_mq_rq_to_pdu(rq);
@@ -495,18 +499,12 @@ static struct blk_mq_ops virtio_mq_ops = {
        .map_queue      = blk_mq_map_queue,
        .alloc_hctx     = blk_mq_alloc_single_hw_queue,
        .free_hctx      = blk_mq_free_single_hw_queue,
-       .init_request   = virtblk_init_request,
        .complete       = virtblk_request_done,
+       .init_request   = virtblk_init_request,
 };
 
-static struct blk_mq_reg virtio_mq_reg = {
-       .ops            = &virtio_mq_ops,
-       .nr_hw_queues   = 1,
-       .queue_depth    = 0, /* Set in virtblk_probe */
-       .numa_node      = NUMA_NO_NODE,
-       .flags          = BLK_MQ_F_SHOULD_MERGE,
-};
-module_param_named(queue_depth, virtio_mq_reg.queue_depth, uint, 0444);
+static unsigned int virtblk_queue_depth;
+module_param_named(queue_depth, virtblk_queue_depth, uint, 0444);
 
 static int virtblk_probe(struct virtio_device *vdev)
 {
@@ -562,20 +560,32 @@ static int virtblk_probe(struct virtio_device *vdev)
        }
 
        /* Default queue sizing is to fill the ring. */
-       if (!virtio_mq_reg.queue_depth) {
-               virtio_mq_reg.queue_depth = vblk->vq->num_free;
+       if (!virtblk_queue_depth) {
+               virtblk_queue_depth = vblk->vq->num_free;
                /* ... but without indirect descs, we use 2 descs per req */
                if (!virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC))
-                       virtio_mq_reg.queue_depth /= 2;
+                       virtblk_queue_depth /= 2;
        }
-       virtio_mq_reg.cmd_size =
+
+       memset(&vblk->tag_set, 0, sizeof(vblk->tag_set));
+       vblk->tag_set.ops = &virtio_mq_ops;
+       vblk->tag_set.nr_hw_queues = 1;
+       vblk->tag_set.queue_depth = virtblk_queue_depth;
+       vblk->tag_set.numa_node = NUMA_NO_NODE;
+       vblk->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
+       vblk->tag_set.cmd_size =
                sizeof(struct virtblk_req) +
                sizeof(struct scatterlist) * sg_elems;
+       vblk->tag_set.driver_data = vblk;
 
-       q = vblk->disk->queue = blk_mq_init_queue(&virtio_mq_reg, vblk);
+       err = blk_mq_alloc_tag_set(&vblk->tag_set);
+       if (err)
+               goto out_put_disk;
+
+       q = vblk->disk->queue = blk_mq_init_queue(&vblk->tag_set);
        if (!q) {
                err = -ENOMEM;
-               goto out_put_disk;
+               goto out_free_tags;
        }
 
        q->queuedata = vblk;
@@ -678,6 +688,8 @@ static int virtblk_probe(struct virtio_device *vdev)
 out_del_disk:
        del_gendisk(vblk->disk);
        blk_cleanup_queue(vblk->disk->queue);
+out_free_tags:
+       blk_mq_free_tag_set(&vblk->tag_set);
 out_put_disk:
        put_disk(vblk->disk);
 out_free_vq:
@@ -704,6 +716,8 @@ static void virtblk_remove(struct virtio_device *vdev)
        del_gendisk(vblk->disk);
        blk_cleanup_queue(vblk->disk->queue);
 
+       blk_mq_free_tag_set(&vblk->tag_set);
+
        /* Stop all the virtqueues. */
        vdev->config->reset(vdev);
 
index 29c1a6e83814b319d9a241cc0965c507c054756c..a4ea0ce83b07b140ddb200763aff016354a5528a 100644 (file)
@@ -33,8 +33,6 @@ struct blk_mq_hw_ctx {
        unsigned int            nr_ctx_map;
        unsigned long           *ctx_map;
 
-       struct request          **rqs;
-       struct list_head        page_list;
        struct blk_mq_tags      *tags;
 
        unsigned long           queued;
@@ -42,7 +40,6 @@ struct blk_mq_hw_ctx {
 #define BLK_MQ_MAX_DISPATCH_ORDER      10
        unsigned long           dispatched[BLK_MQ_MAX_DISPATCH_ORDER];
 
-       unsigned int            queue_depth;
        unsigned int            numa_node;
        unsigned int            cmd_size;       /* per-request extra data */
 
@@ -50,7 +47,7 @@ struct blk_mq_hw_ctx {
        struct kobject          kobj;
 };
 
-struct blk_mq_reg {
+struct blk_mq_tag_set {
        struct blk_mq_ops       *ops;
        unsigned int            nr_hw_queues;
        unsigned int            queue_depth;
@@ -59,18 +56,22 @@ struct blk_mq_reg {
        int                     numa_node;
        unsigned int            timeout;
        unsigned int            flags;          /* BLK_MQ_F_* */
+       void                    *driver_data;
+
+       struct blk_mq_tags      **tags;
 };
 
 typedef int (queue_rq_fn)(struct blk_mq_hw_ctx *, struct request *);
 typedef struct blk_mq_hw_ctx *(map_queue_fn)(struct request_queue *, const int);
-typedef struct blk_mq_hw_ctx *(alloc_hctx_fn)(struct blk_mq_reg *,unsigned int);
+typedef struct blk_mq_hw_ctx *(alloc_hctx_fn)(struct blk_mq_tag_set *,
+               unsigned int);
 typedef void (free_hctx_fn)(struct blk_mq_hw_ctx *, unsigned int);
 typedef int (init_hctx_fn)(struct blk_mq_hw_ctx *, void *, unsigned int);
 typedef void (exit_hctx_fn)(struct blk_mq_hw_ctx *, unsigned int);
-typedef int (init_request_fn)(void *, struct blk_mq_hw_ctx *,
-               struct request *, unsigned int);
-typedef void (exit_request_fn)(void *, struct blk_mq_hw_ctx *,
-               struct request *, unsigned int);
+typedef int (init_request_fn)(void *, struct request *, unsigned int,
+               unsigned int, unsigned int);
+typedef void (exit_request_fn)(void *, struct request *, unsigned int,
+               unsigned int);
 
 struct blk_mq_ops {
        /*
@@ -127,10 +128,13 @@ enum {
        BLK_MQ_MAX_DEPTH        = 2048,
 };
 
-struct request_queue *blk_mq_init_queue(struct blk_mq_reg *, void *);
+struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *);
 int blk_mq_register_disk(struct gendisk *);
 void blk_mq_unregister_disk(struct gendisk *);
 
+int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set);
+void blk_mq_free_tag_set(struct blk_mq_tag_set *set);
+
 void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule);
 
 void blk_mq_insert_request(struct request *, bool, bool, bool);
@@ -139,10 +143,10 @@ void blk_mq_free_request(struct request *rq);
 bool blk_mq_can_queue(struct blk_mq_hw_ctx *);
 struct request *blk_mq_alloc_request(struct request_queue *q, int rw, gfp_t gfp);
 struct request *blk_mq_alloc_reserved_request(struct request_queue *q, int rw, gfp_t gfp);
-struct request *blk_mq_rq_from_tag(struct request_queue *q, unsigned int tag);
+struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag);
 
 struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *, const int ctx_index);
-struct blk_mq_hw_ctx *blk_mq_alloc_single_hw_queue(struct blk_mq_reg *, unsigned int);
+struct blk_mq_hw_ctx *blk_mq_alloc_single_hw_queue(struct blk_mq_tag_set *, unsigned int);
 void blk_mq_free_single_hw_queue(struct blk_mq_hw_ctx *, unsigned int);
 
 bool blk_mq_end_io_partial(struct request *rq, int error,
@@ -173,12 +177,6 @@ static inline void *blk_mq_rq_to_pdu(struct request *rq)
        return (void *) rq + sizeof(*rq);
 }
 
-static inline struct request *blk_mq_tag_to_rq(struct blk_mq_hw_ctx *hctx,
-                                              unsigned int tag)
-{
-       return hctx->rqs[tag];
-}
-
 #define queue_for_each_hw_ctx(q, hctx, i)                              \
        for ((i) = 0; (i) < (q)->nr_hw_queues &&                        \
             ({ hctx = (q)->queue_hw_ctx[i]; 1; }); (i)++)