Initial import

1 files changed, 284 insertions, 0 deletions

diff --git a/block/blk.h b/block/blk.h
new file mode 100644
index 000000000..43b036185
--- /dev/null
+++ b/block/blk.h
@@ -0,0 +1,284 @@
+#ifndef BLK_INTERNAL_H
+#define BLK_INTERNAL_H
+
+#include <linux/idr.h>
+#include <linux/blk-mq.h>
+#include "blk-mq.h"
+
+/* Amount of time in which a process may batch requests */
+#define BLK_BATCH_TIME	(HZ/50UL)
+
+/* Number of requests a "batching" process may submit */
+#define BLK_BATCH_REQ	32
+
+/* Max future timer expiry for timeouts */
+#define BLK_MAX_TIMEOUT		(5 * HZ)
+
+struct blk_flush_queue {
+	unsigned int		flush_queue_delayed:1;
+	unsigned int		flush_pending_idx:1;
+	unsigned int		flush_running_idx:1;
+	unsigned long		flush_pending_since;
+	struct list_head	flush_queue[2];
+	struct list_head	flush_data_in_flight;
+	struct request		*flush_rq;
+	spinlock_t		mq_flush_lock;
+};
+
+extern struct kmem_cache *blk_requestq_cachep;
+extern struct kmem_cache *request_cachep;
+extern struct kobj_type blk_queue_ktype;
+extern struct ida blk_queue_ida;
+
+static inline struct blk_flush_queue *blk_get_flush_queue(
+		struct request_queue *q, struct blk_mq_ctx *ctx)
+{
+	struct blk_mq_hw_ctx *hctx;
+
+	if (!q->mq_ops)
+		return q->fq;
+
+	hctx = q->mq_ops->map_queue(q, ctx->cpu);
+
+	return hctx->fq;
+}
+
+static inline void __blk_get_queue(struct request_queue *q)
+{
+	kobject_get(&q->kobj);
+}
+
+struct blk_flush_queue *blk_alloc_flush_queue(struct request_queue *q,
+		int node, int cmd_size);
+void blk_free_flush_queue(struct blk_flush_queue *q);
+
+int blk_init_rl(struct request_list *rl, struct request_queue *q,
+		gfp_t gfp_mask);
+void blk_exit_rl(struct request_list *rl);
+void init_request_from_bio(struct request *req, struct bio *bio);
+void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
+			struct bio *bio);
+int blk_rq_append_bio(struct request_queue *q, struct request *rq,
+		      struct bio *bio);
+void blk_queue_bypass_start(struct request_queue *q);
+void blk_queue_bypass_end(struct request_queue *q);
+void blk_dequeue_request(struct request *rq);
+void __blk_queue_free_tags(struct request_queue *q);
+bool __blk_end_bidi_request(struct request *rq, int error,
+			    unsigned int nr_bytes, unsigned int bidi_bytes);
+
+void blk_rq_timed_out_timer(unsigned long data);
+unsigned long blk_rq_timeout(unsigned long timeout);
+void blk_add_timer(struct request *req);
+void blk_delete_timer(struct request *);
+
+
+bool bio_attempt_front_merge(struct request_queue *q, struct request *req,
+			     struct bio *bio);
+bool bio_attempt_back_merge(struct request_queue *q, struct request *req,
+			    struct bio *bio);
+bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
+			    unsigned int *request_count);
+
+void blk_account_io_start(struct request *req, bool new_io);
+void blk_account_io_completion(struct request *req, unsigned int bytes);
+void blk_account_io_done(struct request *req);
+
+/*
+ * Internal atomic flags for request handling
+ */
+enum rq_atomic_flags {
+	REQ_ATOM_COMPLETE = 0,
+	REQ_ATOM_STARTED,
+};
+
+/*
+ * EH timer and IO completion will both attempt to 'grab' the request, make
+ * sure that only one of them succeeds
+ */
+static inline int blk_mark_rq_complete(struct request *rq)
+{
+	return test_and_set_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
+}
+
+static inline void blk_clear_rq_complete(struct request *rq)
+{
+	clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
+}
+
+/*
+ * Internal elevator interface
+ */
+#define ELV_ON_HASH(rq) ((rq)->cmd_flags & REQ_HASHED)
+
+void blk_insert_flush(struct request *rq);
+
+static inline struct request *__elv_next_request(struct request_queue *q)
+{
+	struct request *rq;
+	struct blk_flush_queue *fq = blk_get_flush_queue(q, NULL);
+
+	while (1) {
+		if (!list_empty(&q->queue_head)) {
+			rq = list_entry_rq(q->queue_head.next);
+			return rq;
+		}
+
+		/*
+		 * Flush request is running and flush request isn't queueable
+		 * in the drive, we can hold the queue till flush request is
+		 * finished. Even we don't do this, driver can't dispatch next
+		 * requests and will requeue them. And this can improve
+		 * throughput too. For example, we have request flush1, write1,
+		 * flush 2. flush1 is dispatched, then queue is hold, write1
+		 * isn't inserted to queue. After flush1 is finished, flush2
+		 * will be dispatched. Since disk cache is already clean,
+		 * flush2 will be finished very soon, so looks like flush2 is
+		 * folded to flush1.
+		 * Since the queue is hold, a flag is set to indicate the queue
+		 * should be restarted later. Please see flush_end_io() for
+		 * details.
+		 */
+		if (fq->flush_pending_idx != fq->flush_running_idx &&
+				!queue_flush_queueable(q)) {
+			fq->flush_queue_delayed = 1;
+			return NULL;
+		}
+		if (unlikely(blk_queue_bypass(q)) ||
+		    !q->elevator->type->ops.elevator_dispatch_fn(q, 0))
+			return NULL;
+	}
+}
+
+static inline void elv_activate_rq(struct request_queue *q, struct request *rq)
+{
+	struct elevator_queue *e = q->elevator;
+
+	if (e->type->ops.elevator_activate_req_fn)
+		e->type->ops.elevator_activate_req_fn(q, rq);
+}
+
+static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq)
+{
+	struct elevator_queue *e = q->elevator;
+
+	if (e->type->ops.elevator_deactivate_req_fn)
+		e->type->ops.elevator_deactivate_req_fn(q, rq);
+}
+
+#ifdef CONFIG_FAIL_IO_TIMEOUT
+int blk_should_fake_timeout(struct request_queue *);
+ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
+ssize_t part_timeout_store(struct device *, struct device_attribute *,
+				const char *, size_t);
+#else
+static inline int blk_should_fake_timeout(struct request_queue *q)
+{
+	return 0;
+}
+#endif
+
+int ll_back_merge_fn(struct request_queue *q, struct request *req,
+		     struct bio *bio);
+int ll_front_merge_fn(struct request_queue *q, struct request *req, 
+		      struct bio *bio);
+int attempt_back_merge(struct request_queue *q, struct request *rq);
+int attempt_front_merge(struct request_queue *q, struct request *rq);
+int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
+				struct request *next);
+void blk_recalc_rq_segments(struct request *rq);
+void blk_rq_set_mixed_merge(struct request *rq);
+bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
+int blk_try_merge(struct request *rq, struct bio *bio);
+
+void blk_queue_congestion_threshold(struct request_queue *q);
+
+void __blk_run_queue_uncond(struct request_queue *q);
+
+int blk_dev_init(void);
+
+
+/*
+ * Return the threshold (number of used requests) at which the queue is
+ * considered to be congested.  It include a little hysteresis to keep the
+ * context switch rate down.
+ */
+static inline int queue_congestion_on_threshold(struct request_queue *q)
+{
+	return q->nr_congestion_on;
+}
+
+/*
+ * The threshold at which a queue is considered to be uncongested
+ */
+static inline int queue_congestion_off_threshold(struct request_queue *q)
+{
+	return q->nr_congestion_off;
+}
+
+extern int blk_update_nr_requests(struct request_queue *, unsigned int);
+
+/*
+ * Contribute to IO statistics IFF:
+ *
+ *	a) it's attached to a gendisk, and
+ *	b) the queue had IO stats enabled when this request was started, and
+ *	c) it's a file system request
+ */
+static inline int blk_do_io_stat(struct request *rq)
+{
+	return rq->rq_disk &&
+	       (rq->cmd_flags & REQ_IO_STAT) &&
+		(rq->cmd_type == REQ_TYPE_FS);
+}
+
+/*
+ * Internal io_context interface
+ */
+void get_io_context(struct io_context *ioc);
+struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q);
+struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q,
+			     gfp_t gfp_mask);
+void ioc_clear_queue(struct request_queue *q);
+
+int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node);
+
+/**
+ * create_io_context - try to create task->io_context
+ * @gfp_mask: allocation mask
+ * @node: allocation node
+ *
+ * If %current->io_context is %NULL, allocate a new io_context and install
+ * it.  Returns the current %current->io_context which may be %NULL if
+ * allocation failed.
+ *
+ * Note that this function can't be called with IRQ disabled because
+ * task_lock which protects %current->io_context is IRQ-unsafe.
+ */
+static inline struct io_context *create_io_context(gfp_t gfp_mask, int node)
+{
+	WARN_ON_ONCE(irqs_disabled());
+	if (unlikely(!current->io_context))
+		create_task_io_context(current, gfp_mask, node);
+	return current->io_context;
+}
+
+/*
+ * Internal throttling interface
+ */
+#ifdef CONFIG_BLK_DEV_THROTTLING
+extern bool blk_throtl_bio(struct request_queue *q, struct bio *bio);
+extern void blk_throtl_drain(struct request_queue *q);
+extern int blk_throtl_init(struct request_queue *q);
+extern void blk_throtl_exit(struct request_queue *q);
+#else /* CONFIG_BLK_DEV_THROTTLING */
+static inline bool blk_throtl_bio(struct request_queue *q, struct bio *bio)
+{
+	return false;
+}
+static inline void blk_throtl_drain(struct request_queue *q) { }
+static inline int blk_throtl_init(struct request_queue *q) { return 0; }
+static inline void blk_throtl_exit(struct request_queue *q) { }
+#endif /* CONFIG_BLK_DEV_THROTTLING */
+
+#endif /* BLK_INTERNAL_H */