Signed-off-by: Jens Axboe <axboe@xxxxxx>
---
block/blk-mq-sched.c | 243 +++++++++++++++++++++++++++++++++++++++++++++++++++
block/blk-mq-sched.h | 168 +++++++++++++++++++++++++++++++++++
2 files changed, 411 insertions(+)
create mode 100644 block/blk-mq-sched.c
create mode 100644 block/blk-mq-sched.h
diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c
new file mode 100644
index 000000000000..8317b26990f8
--- /dev/null
+++ b/block/blk-mq-sched.c
@@ -0,0 +1,243 @@
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#include <linux/blk-mq.h>
+#include "blk.h"
+#include "blk-mq.h"
+#include "blk-mq-sched.h"
+#include "blk-mq-tag.h"
+#include "blk-wbt.h"
+
+/*
+ * Empty set
+ */
+static struct blk_mq_ops mq_sched_tag_ops = {
+ .queue_rq = NULL,
+};
+
+void blk_mq_sched_free_requests(struct blk_mq_tags *tags)
+{
+ blk_mq_free_rq_map(NULL, tags, 0);
+}
+EXPORT_SYMBOL_GPL(blk_mq_sched_free_requests);
+
+struct blk_mq_tags *blk_mq_sched_alloc_requests(unsigned int depth,
+ unsigned int numa_node)
+{
+ struct blk_mq_tag_set set = {
+ .ops = &mq_sched_tag_ops,
+ .nr_hw_queues = 1,
+ .queue_depth = depth,
+ .numa_node = numa_node,
+ };
+
+ return blk_mq_init_rq_map(&set, 0);
+}
+EXPORT_SYMBOL_GPL(blk_mq_sched_alloc_requests);
+
+void blk_mq_sched_free_hctx_data(struct request_queue *q,
+ void (*exit)(struct blk_mq_hw_ctx *))
+{
+ struct blk_mq_hw_ctx *hctx;
+ int i;
+
+ queue_for_each_hw_ctx(q, hctx, i) {
+ if (exit)
+ exit(hctx);
+ kfree(hctx->sched_data);
+ hctx->sched_data = NULL;
+ }
+}
+EXPORT_SYMBOL_GPL(blk_mq_sched_free_hctx_data);
+
+int blk_mq_sched_init_hctx_data(struct request_queue *q, size_t size,
+ void (*init)(struct blk_mq_hw_ctx *))
+{
+ struct blk_mq_hw_ctx *hctx;
+ int i;
+
+ queue_for_each_hw_ctx(q, hctx, i) {
+ hctx->sched_data = kmalloc_node(size, GFP_KERNEL, hctx->numa_node);
+ if (!hctx->sched_data)
+ goto error;
+
+ if (init)
+ init(hctx);
+ }
+
+ return 0;
+error:
+ blk_mq_sched_free_hctx_data(q, NULL);
+ return -ENOMEM;
+}
+EXPORT_SYMBOL_GPL(blk_mq_sched_init_hctx_data);
+
+struct request *blk_mq_sched_alloc_shadow_request(struct request_queue *q,
+ struct blk_mq_alloc_data *data,
+ struct blk_mq_tags *tags,
+ atomic_t *wait_index)
+{
+ struct sbq_wait_state *ws;
+ DEFINE_WAIT(wait);
+ struct request *rq;
+ int tag;
+
+ tag = __sbitmap_queue_get(&tags->bitmap_tags);
+ if (tag != -1)
+ goto done;
+
+ if (data->flags & BLK_MQ_REQ_NOWAIT)
+ return NULL;
+
+ ws = sbq_wait_ptr(&tags->bitmap_tags, wait_index);
+ do {
+ prepare_to_wait(&ws->wait, &wait, TASK_UNINTERRUPTIBLE);
+
+ tag = __sbitmap_queue_get(&tags->bitmap_tags);
+ if (tag != -1)
+ break;
+
+ blk_mq_run_hw_queue(data->hctx, false);
+
+ tag = __sbitmap_queue_get(&tags->bitmap_tags);
+ if (tag != -1)
+ break;
+
+ blk_mq_put_ctx(data->ctx);
+ io_schedule();
+
+ data->ctx = blk_mq_get_ctx(data->q);
+ data->hctx = blk_mq_map_queue(data->q, data->ctx->cpu);
+ finish_wait(&ws->wait, &wait);
+ ws = sbq_wait_ptr(&tags->bitmap_tags, wait_index);
+ } while (1);
+
+ finish_wait(&ws->wait, &wait);
+done:
+ rq = tags->rqs[tag];
+ rq->tag = tag;
+ return rq;
+}
+EXPORT_SYMBOL_GPL(blk_mq_sched_alloc_shadow_request);
+
+void blk_mq_sched_free_shadow_request(struct blk_mq_tags *tags,
+ struct request *rq)
+{
+ sbitmap_queue_clear(&tags->bitmap_tags, rq->tag, rq->mq_ctx->cpu);
+}
+EXPORT_SYMBOL_GPL(blk_mq_sched_free_shadow_request);
+
+static void rq_copy(struct request *rq, struct request *src)
+{
+#define FIELD_COPY(dst, src, name) ((dst)->name = (src)->name)
+ FIELD_COPY(rq, src, cpu);
+ FIELD_COPY(rq, src, cmd_type);
+ FIELD_COPY(rq, src, cmd_flags);
+ rq->rq_flags |= (src->rq_flags & (RQF_PREEMPT | RQF_QUIET | RQF_PM | RQF_DONTPREP));
+ rq->rq_flags &= ~RQF_IO_STAT;
+ FIELD_COPY(rq, src, __data_len);
+ FIELD_COPY(rq, src, __sector);
+ FIELD_COPY(rq, src, bio);
+ FIELD_COPY(rq, src, biotail);
+ FIELD_COPY(rq, src, rq_disk);
+ FIELD_COPY(rq, src, part);
+ FIELD_COPY(rq, src, nr_phys_segments);
+#if defined(CONFIG_BLK_DEV_INTEGRITY)
+ FIELD_COPY(rq, src, nr_integrity_segments);
+#endif
+ FIELD_COPY(rq, src, ioprio);
+ FIELD_COPY(rq, src, timeout);
+
+ if (src->cmd_type == REQ_TYPE_BLOCK_PC) {
+ FIELD_COPY(rq, src, cmd);
+ FIELD_COPY(rq, src, cmd_len);
+ FIELD_COPY(rq, src, extra_len);
+ FIELD_COPY(rq, src, sense_len);
+ FIELD_COPY(rq, src, resid_len);
+ FIELD_COPY(rq, src, sense);
+ FIELD_COPY(rq, src, retries);
+ }
+
+ src->bio = src->biotail = NULL;
+}
+
+static void sched_rq_end_io(struct request *rq, int error)
+{
+ struct request *sched_rq = rq->end_io_data;
+
+ FIELD_COPY(sched_rq, rq, resid_len);
+ FIELD_COPY(sched_rq, rq, extra_len);
+ FIELD_COPY(sched_rq, rq, sense_len);
+ FIELD_COPY(sched_rq, rq, errors);
+ FIELD_COPY(sched_rq, rq, retries);
+
+ blk_account_io_completion(sched_rq, blk_rq_bytes(sched_rq));
+ blk_account_io_done(sched_rq);
+
+ wbt_done(sched_rq->q->rq_wb, &sched_rq->issue_stat);
+
+ if (sched_rq->end_io)
+ sched_rq->end_io(sched_rq, error);
+
+ blk_mq_free_request(rq);
+}
+
+struct request *
+blk_mq_sched_request_from_shadow(struct blk_mq_hw_ctx *hctx,
+ struct request *(*get_sched_rq)(struct blk_mq_hw_ctx *))
+{
+ struct blk_mq_alloc_data data;
+ struct request *sched_rq, *rq;
+
+ data.q = hctx->queue;
+ data.flags = BLK_MQ_REQ_NOWAIT;
+ data.ctx = blk_mq_get_ctx(hctx->queue);
+ data.hctx = hctx;
+
+ rq = __blk_mq_alloc_request(&data, 0);
+ blk_mq_put_ctx(data.ctx);
+
+ if (!rq) {
+ blk_mq_stop_hw_queue(hctx);
+ return NULL;
+ }
+
+ sched_rq = get_sched_rq(hctx);
+
+ if (!sched_rq) {
+ blk_queue_enter_live(hctx->queue);
+ __blk_mq_free_request(hctx, data.ctx, rq);
+ return NULL;
+ }
+
+ rq_copy(rq, sched_rq);
+ rq->end_io = sched_rq_end_io;
+ rq->end_io_data = sched_rq;
+
+ return rq;
+}
+EXPORT_SYMBOL_GPL(blk_mq_sched_request_from_shadow);
+
+void blk_mq_sched_dispatch_requests(struct blk_mq_hw_ctx *hctx)
+{
+ struct elevator_queue *e = hctx->queue->elevator;
+ struct request *rq;
+ LIST_HEAD(rq_list);
+
+ if (unlikely(blk_mq_hctx_stopped(hctx)))
+ return;
+
+ hctx->run++;
+
+ if (!list_empty(&hctx->dispatch)) {
+ spin_lock(&hctx->lock);
+ if (!list_empty(&hctx->dispatch))
+ list_splice_init(&hctx->dispatch, &rq_list);
+ spin_unlock(&hctx->lock);
+ }
+
+ while ((rq = e->type->mq_ops.dispatch_request(hctx)) != NULL)
+ list_add_tail(&rq->queuelist, &rq_list);
+
+ blk_mq_dispatch_rq_list(hctx, &rq_list);
+}
diff --git a/block/blk-mq-sched.h b/block/blk-mq-sched.h
new file mode 100644
index 000000000000..125e14e5274a
--- /dev/null
+++ b/block/blk-mq-sched.h
@@ -0,0 +1,168 @@
+#ifndef BLK_MQ_SCHED_H
+#define BLK_MQ_SCHED_H
+
+#include "blk-mq.h"
+
+struct blk_mq_hw_ctx;
+struct blk_mq_ctx;
+struct request_queue;
+
+struct blk_mq_tags *blk_mq_sched_alloc_requests(unsigned int depth, unsigned int numa_node);
+void blk_mq_sched_free_requests(struct blk_mq_tags *tags);
+
+int blk_mq_sched_init_hctx_data(struct request_queue *q, size_t size,
+ void (*init)(struct blk_mq_hw_ctx *));
+void blk_mq_sched_free_hctx_data(struct request_queue *q,
+ void (*exit)(struct blk_mq_hw_ctx *));
+
+void blk_mq_sched_free_shadow_request(struct blk_mq_tags *tags,
+ struct request *rq);
+struct request *blk_mq_sched_alloc_shadow_request(struct request_queue *q,
+ struct blk_mq_alloc_data *data,
+ struct blk_mq_tags *tags,
+ atomic_t *wait_index);
+struct request *
+blk_mq_sched_request_from_shadow(struct blk_mq_hw_ctx *hctx,
+ struct request *(*get_sched_rq)(struct blk_mq_hw_ctx *));
+
+
+struct blk_mq_alloc_data {
+ /* input parameter */
+ struct request_queue *q;
+ unsigned int flags;
+
+ /* input & output parameter */
+ struct blk_mq_ctx *ctx;
+ struct blk_mq_hw_ctx *hctx;
+};
+
+static inline void blk_mq_set_alloc_data(struct blk_mq_alloc_data *data,
+ struct request_queue *q, unsigned int flags,
+ struct blk_mq_ctx *ctx, struct blk_mq_hw_ctx *hctx)
+{
+ data->q = q;
+ data->flags = flags;
+ data->ctx = ctx;
+ data->hctx = hctx;
+}
+
+void blk_mq_sched_dispatch_requests(struct blk_mq_hw_ctx *hctx);
+
+static inline bool
+blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio)
+{
+ struct elevator_queue *e = q->elevator;
+
+ if (blk_queue_nomerges(q) || !bio_mergeable(bio))
+ return false;
+
+ if (e) {
+ struct blk_mq_ctx *ctx = blk_mq_get_ctx(q);
+ struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu);
+
+ blk_mq_put_ctx(ctx);
+ return e->type->mq_ops.bio_merge(hctx, bio);
+ }
+
+ return false;
+}
+
+static inline struct request *
+blk_mq_sched_get_request(struct request_queue *q, struct bio *bio,
+ struct blk_mq_alloc_data *data)
+{
+ struct elevator_queue *e = q->elevator;
+ struct blk_mq_hw_ctx *hctx;
+ struct blk_mq_ctx *ctx;
+ struct request *rq;
+
+ blk_queue_enter_live(q);
+ ctx = blk_mq_get_ctx(q);
+ hctx = blk_mq_map_queue(q, ctx->cpu);
+
+ blk_mq_set_alloc_data(data, q, 0, ctx, hctx);
+
+ if (e)
+ rq = e->type->mq_ops.get_request(q, bio, data);
+ else
+ rq = __blk_mq_alloc_request(data, bio->bi_opf);
+
+ if (rq)
+ data->hctx->queued++;
+
+ return rq;
+
+}
+
+static inline void
+blk_mq_sched_insert_request(struct request *rq, bool at_head, bool run_queue,
+ bool async)
+{
+ struct request_queue *q = rq->q;
+ struct elevator_queue *e = q->elevator;
+ struct blk_mq_ctx *ctx = rq->mq_ctx;
+ struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu);
+
+ if (e)
+ e->type->mq_ops.insert_request(hctx, rq, at_head);
+ else {
+ spin_lock(&ctx->lock);
+ __blk_mq_insert_request(hctx, rq, at_head);
+ spin_unlock(&ctx->lock);
+ }
+
+ if (run_queue)
+ blk_mq_run_hw_queue(hctx, async);
+}
+
+static inline bool
+blk_mq_sched_allow_merge(struct request_queue *q, struct request *rq,
+ struct bio *bio)
+{
+ struct elevator_queue *e = q->elevator;
+
+ if (e && e->type->mq_ops.allow_merge)
+ return e->type->mq_ops.allow_merge(q, rq, bio);
+
+ return true;
+}
+
+static inline void
+blk_mq_sched_completed_request(struct blk_mq_hw_ctx *hctx, struct request *rq)
+{
+ struct elevator_queue *e = hctx->queue->elevator;
+
+ if (e && e->type->mq_ops.completed_request)
+ e->type->mq_ops.completed_request(hctx, rq);
+}
+
+static inline void blk_mq_sched_started_request(struct request *rq)
+{
+ struct request_queue *q = rq->q;
+ struct elevator_queue *e = q->elevator;
+
+ if (e && e->type->mq_ops.started_request)
+ e->type->mq_ops.started_request(rq);
+}
+
+static inline void blk_mq_sched_requeue_request(struct request *rq)
+{
+ struct request_queue *q = rq->q;
+ struct elevator_queue *e = q->elevator;
+
+ if (e && e->type->mq_ops.requeue_request)
+ e->type->mq_ops.requeue_request(rq);
+}
+
+static inline bool blk_mq_sched_has_work(struct blk_mq_hw_ctx *hctx)
+{
+ struct elevator_queue *e = hctx->queue->elevator;
+
+ if (e && e->type->mq_ops.has_work)
+ return e->type->mq_ops.has_work(hctx);
+
+ return false;
+}
+
+
+#endif
--
2.7.4
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