UBUNTU: Ubuntu-2.6.38-12.51

[linux-flexiantxendom0-natty.git] / block / blk.h

diff --git a/block/blk.h b/block/blk.h
index d88549d..e03adf8 100644 (file)
--- a/block/blk.h
+++ b/block/blk.h
@@ -1,13 +1,126 @@
 #ifndef BLK_INTERNAL_H
 #define BLK_INTERNAL_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
+
 extern struct kmem_cache *blk_requestq_cachep;
 extern struct kobj_type blk_queue_ktype;
 
+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_dequeue_request(struct request *rq);
 void __blk_queue_free_tags(struct request_queue *q);
 
+void blk_unplug_work(struct work_struct *work);
+void blk_unplug_timeout(unsigned long data);
+void blk_rq_timed_out_timer(unsigned long data);
+void blk_delete_timer(struct request *);
+void blk_add_timer(struct request *);
+void __generic_unplug_device(struct request_queue *);
+
+/*
+ * Internal atomic flags for request handling
+ */
+enum rq_atomic_flags {
+       REQ_ATOM_COMPLETE = 0,
+};
+
+/*
+ * EH timer and IO completion will both attempt to 'grab' the request, make
+ * sure that only one of them suceeds
+ */
+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)                (!hlist_unhashed(&(rq)->hash))
+
+struct request *blk_do_flush(struct request_queue *q, struct request *rq);
+
+static inline struct request *__elv_next_request(struct request_queue *q)
+{
+       struct request *rq;
+
+       while (1) {
+               while (!list_empty(&q->queue_head)) {
+                       rq = list_entry_rq(q->queue_head.next);
+                       if (!(rq->cmd_flags & (REQ_FLUSH | REQ_FUA)) ||
+                           rq == &q->flush_rq)
+                               return rq;
+                       rq = blk_do_flush(q, rq);
+                       if (rq)
+                               return rq;
+               }
+
+               if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags) ||
+                   !q->elevator->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->ops->elevator_activate_req_fn)
+               e->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->ops->elevator_deactivate_req_fn)
+               e->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
+
+struct io_context *current_io_context(gfp_t gfp_flags, int node);
+
+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);
+void blk_recalc_rq_segments(struct request *rq);
+void blk_rq_set_mixed_merge(struct request *rq);
+
 void blk_queue_congestion_threshold(struct request_queue *q);
 
+int blk_dev_init(void);
+
+void elv_quiesce_start(struct request_queue *q);
+void elv_quiesce_end(struct request_queue *q);
+
+
 /*
  * Return the threshold (number of used requests) at which the queue is
  * considered to be congested.  It include a little hysteresis to keep the
@@ -26,4 +139,35 @@ static inline int queue_congestion_off_threshold(struct request_queue *q)
        return q->nr_congestion_off;
 }
 
+static inline int blk_cpu_to_group(int cpu)
+{
+       int group = NR_CPUS;
+#ifdef CONFIG_SCHED_MC
+       const struct cpumask *mask = cpu_coregroup_mask(cpu);
+       group = cpumask_first(mask);
+#elif defined(CONFIG_SCHED_SMT)
+       group = cpumask_first(topology_thread_cpumask(cpu));
+#else
+       return cpu;
+#endif
+       if (likely(group < NR_CPUS))
+               return group;
+       return cpu;
+}
+
+/*
+ * 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 or a discard 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 ||
+               (rq->cmd_flags & REQ_DISCARD));
+}
+
 #endif