EXPORT_SYMBOL(blk_mq_can_queue);
static void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx,
- struct request *rq, unsigned int rw_flags)
+ struct request *rq, int op,
+ unsigned int op_flags)
{
if (blk_queue_io_stat(q))
- rw_flags |= REQ_IO_STAT;
+ op_flags |= REQ_IO_STAT;
INIT_LIST_HEAD(&rq->queuelist);
/* csd/requeue_work/fifo_time is initialized before use */
rq->q = q;
rq->mq_ctx = ctx;
- rq->cmd_flags |= rw_flags;
+ req_set_op_attrs(rq, op, op_flags);
/* do not touch atomic flags, it needs atomic ops against the timer */
rq->cpu = -1;
INIT_HLIST_NODE(&rq->hash);
rq->end_io_data = NULL;
rq->next_rq = NULL;
- ctx->rq_dispatched[rw_is_sync(rw_flags)]++;
+ ctx->rq_dispatched[rw_is_sync(op, op_flags)]++;
}
static struct request *
-__blk_mq_alloc_request(struct blk_mq_alloc_data *data, int rw)
+__blk_mq_alloc_request(struct blk_mq_alloc_data *data, int op, int op_flags)
{
struct request *rq;
unsigned int tag;
}
rq->tag = tag;
- blk_mq_rq_ctx_init(data->q, data->ctx, rq, rw);
+ blk_mq_rq_ctx_init(data->q, data->ctx, rq, op, op_flags);
return rq;
}
hctx = q->mq_ops->map_queue(q, ctx->cpu);
blk_mq_set_alloc_data(&alloc_data, q, flags, ctx, hctx);
- rq = __blk_mq_alloc_request(&alloc_data, rw);
+ rq = __blk_mq_alloc_request(&alloc_data, rw, 0);
if (!rq && !(flags & BLK_MQ_REQ_NOWAIT)) {
__blk_mq_run_hw_queue(hctx);
blk_mq_put_ctx(ctx);
ctx = blk_mq_get_ctx(q);
hctx = q->mq_ops->map_queue(q, ctx->cpu);
blk_mq_set_alloc_data(&alloc_data, q, flags, ctx, hctx);
- rq = __blk_mq_alloc_request(&alloc_data, rw);
+ rq = __blk_mq_alloc_request(&alloc_data, rw, 0);
ctx = alloc_data.ctx;
}
blk_mq_put_ctx(ctx);
blk_queue_exit(q);
return ERR_PTR(-EWOULDBLOCK);
}
+
+ rq->__data_len = 0;
+ rq->__sector = (sector_t) -1;
+ rq->bio = rq->biotail = NULL;
return rq;
}
EXPORT_SYMBOL(blk_mq_alloc_request);
+struct request *blk_mq_alloc_request_hctx(struct request_queue *q, int rw,
+ unsigned int flags, unsigned int hctx_idx)
+{
+ struct blk_mq_hw_ctx *hctx;
+ struct blk_mq_ctx *ctx;
+ struct request *rq;
+ struct blk_mq_alloc_data alloc_data;
+ int ret;
+
+ /*
+ * If the tag allocator sleeps we could get an allocation for a
+ * different hardware context. No need to complicate the low level
+ * allocator for this for the rare use case of a command tied to
+ * a specific queue.
+ */
+ if (WARN_ON_ONCE(!(flags & BLK_MQ_REQ_NOWAIT)))
+ return ERR_PTR(-EINVAL);
+
+ if (hctx_idx >= q->nr_hw_queues)
+ return ERR_PTR(-EIO);
+
+ ret = blk_queue_enter(q, true);
+ if (ret)
+ return ERR_PTR(ret);
+
+ hctx = q->queue_hw_ctx[hctx_idx];
+ ctx = __blk_mq_get_ctx(q, cpumask_first(hctx->cpumask));
+
+ blk_mq_set_alloc_data(&alloc_data, q, flags, ctx, hctx);
+ rq = __blk_mq_alloc_request(&alloc_data, rw, 0);
+ if (!rq) {
+ blk_queue_exit(q);
+ return ERR_PTR(-EWOULDBLOCK);
+ }
+
+ return rq;
+}
+EXPORT_SYMBOL_GPL(blk_mq_alloc_request_hctx);
+
static void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx,
struct blk_mq_ctx *ctx, struct request *rq)
{
};
int i;
- if (blk_queue_enter(q, true))
+ /* A deadlock might occur if a request is stuck requiring a
+ * timeout at the same time a queue freeze is waiting
+ * completion, since the timeout code would not be able to
+ * acquire the queue reference here.
+ *
+ * That's why we don't use blk_queue_enter here; instead, we use
+ * percpu_ref_tryget directly, because we need to be able to
+ * obtain a reference even in the short window between the queue
+ * starting to freeze, by dropping the first reference in
+ * blk_mq_freeze_queue_start, and the moment the last request is
+ * consumed, marked by the instant q_usage_counter reaches
+ * zero.
+ */
+ if (!percpu_ref_tryget(&q->q_usage_counter))
return;
blk_mq_queue_tag_busy_iter(q, blk_mq_check_expired, &data);
struct list_head *dptr;
int queued;
- WARN_ON(!cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask));
-
if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->state)))
return;
+ WARN_ON(!cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask) &&
+ cpu_online(hctx->next_cpu));
+
hctx->run++;
/*
switch (ret) {
case BLK_MQ_RQ_QUEUE_OK:
queued++;
- continue;
+ break;
case BLK_MQ_RQ_QUEUE_BUSY:
list_add(&rq->queuelist, &rq_list);
__blk_mq_requeue_request(rq);
EXPORT_SYMBOL(blk_mq_delay_queue);
static inline void __blk_mq_insert_req_list(struct blk_mq_hw_ctx *hctx,
- struct blk_mq_ctx *ctx,
struct request *rq,
bool at_head)
{
+ struct blk_mq_ctx *ctx = rq->mq_ctx;
+
trace_block_rq_insert(hctx->queue, rq);
if (at_head)
{
struct blk_mq_ctx *ctx = rq->mq_ctx;
- __blk_mq_insert_req_list(hctx, ctx, rq, at_head);
+ __blk_mq_insert_req_list(hctx, rq, at_head);
blk_mq_hctx_mark_pending(hctx, ctx);
}
void blk_mq_insert_request(struct request *rq, bool at_head, bool run_queue,
- bool async)
+ bool async)
{
+ struct blk_mq_ctx *ctx = rq->mq_ctx;
struct request_queue *q = rq->q;
struct blk_mq_hw_ctx *hctx;
- struct blk_mq_ctx *ctx = rq->mq_ctx, *current_ctx;
-
- current_ctx = blk_mq_get_ctx(q);
- if (!cpu_online(ctx->cpu))
- rq->mq_ctx = ctx = current_ctx;
hctx = q->mq_ops->map_queue(q, ctx->cpu);
if (run_queue)
blk_mq_run_hw_queue(hctx, async);
-
- blk_mq_put_ctx(current_ctx);
}
static void blk_mq_insert_requests(struct request_queue *q,
{
struct blk_mq_hw_ctx *hctx;
- struct blk_mq_ctx *current_ctx;
trace_block_unplug(q, depth, !from_schedule);
- current_ctx = blk_mq_get_ctx(q);
-
- if (!cpu_online(ctx->cpu))
- ctx = current_ctx;
hctx = q->mq_ops->map_queue(q, ctx->cpu);
/*
struct request *rq;
rq = list_first_entry(list, struct request, queuelist);
+ BUG_ON(rq->mq_ctx != ctx);
list_del_init(&rq->queuelist);
- rq->mq_ctx = ctx;
- __blk_mq_insert_req_list(hctx, ctx, rq, false);
+ __blk_mq_insert_req_list(hctx, rq, false);
}
blk_mq_hctx_mark_pending(hctx, ctx);
spin_unlock(&ctx->lock);
blk_mq_run_hw_queue(hctx, from_schedule);
- blk_mq_put_ctx(current_ctx);
}
static int plug_ctx_cmp(void *priv, struct list_head *a, struct list_head *b)
struct blk_mq_hw_ctx *hctx;
struct blk_mq_ctx *ctx;
struct request *rq;
- int rw = bio_data_dir(bio);
+ int op = bio_data_dir(bio);
+ int op_flags = 0;
struct blk_mq_alloc_data alloc_data;
blk_queue_enter_live(q);
ctx = blk_mq_get_ctx(q);
hctx = q->mq_ops->map_queue(q, ctx->cpu);
- if (rw_is_sync(bio->bi_rw))
- rw |= REQ_SYNC;
+ if (rw_is_sync(bio_op(bio), bio->bi_opf))
+ op_flags |= REQ_SYNC;
- trace_block_getrq(q, bio, rw);
+ trace_block_getrq(q, bio, op);
blk_mq_set_alloc_data(&alloc_data, q, BLK_MQ_REQ_NOWAIT, ctx, hctx);
- rq = __blk_mq_alloc_request(&alloc_data, rw);
+ rq = __blk_mq_alloc_request(&alloc_data, op, op_flags);
if (unlikely(!rq)) {
__blk_mq_run_hw_queue(hctx);
blk_mq_put_ctx(ctx);
- trace_block_sleeprq(q, bio, rw);
+ trace_block_sleeprq(q, bio, op);
ctx = blk_mq_get_ctx(q);
hctx = q->mq_ops->map_queue(q, ctx->cpu);
blk_mq_set_alloc_data(&alloc_data, q, 0, ctx, hctx);
- rq = __blk_mq_alloc_request(&alloc_data, rw);
+ rq = __blk_mq_alloc_request(&alloc_data, op, op_flags);
ctx = alloc_data.ctx;
hctx = alloc_data.hctx;
}
*/
static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
{
- const int is_sync = rw_is_sync(bio->bi_rw);
- const int is_flush_fua = bio->bi_rw & (REQ_FLUSH | REQ_FUA);
+ const int is_sync = rw_is_sync(bio_op(bio), bio->bi_opf);
+ const int is_flush_fua = bio->bi_opf & (REQ_PREFLUSH | REQ_FUA);
struct blk_map_ctx data;
struct request *rq;
unsigned int request_count = 0;
*/
static blk_qc_t blk_sq_make_request(struct request_queue *q, struct bio *bio)
{
- const int is_sync = rw_is_sync(bio->bi_rw);
- const int is_flush_fua = bio->bi_rw & (REQ_FLUSH | REQ_FUA);
+ const int is_sync = rw_is_sync(bio_op(bio), bio->bi_opf);
+ const int is_flush_fua = bio->bi_opf & (REQ_PREFLUSH | REQ_FUA);
struct blk_plug *plug;
unsigned int request_count = 0;
struct blk_map_ctx data;
return 0;
}
+/*
+ * 'cpu' is going away. splice any existing rq_list entries from this
+ * software queue to the hw queue dispatch list, and ensure that it
+ * gets run.
+ */
static int blk_mq_hctx_cpu_offline(struct blk_mq_hw_ctx *hctx, int cpu)
{
- struct request_queue *q = hctx->queue;
struct blk_mq_ctx *ctx;
LIST_HEAD(tmp);
- /*
- * Move ctx entries to new CPU, if this one is going away.
- */
- ctx = __blk_mq_get_ctx(q, cpu);
+ ctx = __blk_mq_get_ctx(hctx->queue, cpu);
spin_lock(&ctx->lock);
if (!list_empty(&ctx->rq_list)) {
if (list_empty(&tmp))
return NOTIFY_OK;
- ctx = blk_mq_get_ctx(q);
- spin_lock(&ctx->lock);
-
- while (!list_empty(&tmp)) {
- struct request *rq;
-
- rq = list_first_entry(&tmp, struct request, queuelist);
- rq->mq_ctx = ctx;
- list_move_tail(&rq->queuelist, &ctx->rq_list);
- }
-
- hctx = q->mq_ops->map_queue(q, ctx->cpu);
- blk_mq_hctx_mark_pending(hctx, ctx);
-
- spin_unlock(&ctx->lock);
+ spin_lock(&hctx->lock);
+ list_splice_tail_init(&tmp, &hctx->dispatch);
+ spin_unlock(&hctx->lock);
blk_mq_run_hw_queue(hctx, true);
- blk_mq_put_ctx(ctx);
return NOTIFY_OK;
}
projects / linux-2.6-block.git / blobdiff