X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=block%2Felevator.c;h=ac5310ef8270984e32799e0524917abf4246853a;hb=a1c1f281b84a751fdb5ff919da3b09df7297619f;hp=f9736fbdab0308f7121694df2faa3ffa68258994;hpb=b47711bfbcd4eb77ca61ef0162487b20e023ae55;p=linux-2.6-omap-h63xx.git

diff --git a/block/elevator.c b/block/elevator.c
index f9736fbdab0..ac5310ef827 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -45,7 +45,8 @@ static LIST_HEAD(elv_list);
  */
 static const int elv_hash_shift = 6;
 #define ELV_HASH_BLOCK(sec)	((sec) >> 3)
-#define ELV_HASH_FN(sec)	(hash_long(ELV_HASH_BLOCK((sec)), elv_hash_shift))
+#define ELV_HASH_FN(sec)	\
+		(hash_long(ELV_HASH_BLOCK((sec)), elv_hash_shift))
 #define ELV_HASH_ENTRIES	(1 << elv_hash_shift)
 #define rq_hash_key(rq)		((rq)->sector + (rq)->nr_sectors)
 #define ELV_ON_HASH(rq)		(!hlist_unhashed(&(rq)->hash))
@@ -68,7 +69,7 @@ static int elv_iosched_allow_merge(struct request *rq, struct bio *bio)
 /*
  * can we safely merge with this request?
  */
-inline int elv_rq_merge_ok(struct request *rq, struct bio *bio)
+int elv_rq_merge_ok(struct request *rq, struct bio *bio)
 {
 	if (!rq_mergeable(rq))
 		return 0;
@@ -133,6 +134,21 @@ static struct elevator_type *elevator_get(const char *name)
 	spin_lock(&elv_list_lock);
 
 	e = elevator_find(name);
+	if (!e) {
+		char elv[ELV_NAME_MAX + strlen("-iosched")];
+
+		spin_unlock(&elv_list_lock);
+
+		if (!strcmp(name, "anticipatory"))
+			sprintf(elv, "as-iosched");
+		else
+			sprintf(elv, "%s-iosched", name);
+
+		request_module(elv);
+		spin_lock(&elv_list_lock);
+		e = elevator_find(name);
+	}
+
 	if (e && !try_module_get(e->elevator_owner))
 		e = NULL;
 
@@ -224,15 +240,27 @@ int elevator_init(struct request_queue *q, char *name)
 	q->end_sector = 0;
 	q->boundary_rq = NULL;
 
-	if (name && !(e = elevator_get(name)))
-		return -EINVAL;
+	if (name) {
+		e = elevator_get(name);
+		if (!e)
+			return -EINVAL;
+	}
 
-	if (!e && *chosen_elevator && !(e = elevator_get(chosen_elevator)))
-		printk("I/O scheduler %s not found\n", chosen_elevator);
+	if (!e && *chosen_elevator) {
+		e = elevator_get(chosen_elevator);
+		if (!e)
+			printk(KERN_ERR "I/O scheduler %s not found\n",
+							chosen_elevator);
+	}
 
-	if (!e && !(e = elevator_get(CONFIG_DEFAULT_IOSCHED))) {
-		printk("Default I/O scheduler not found, using no-op\n");
-		e = elevator_get("noop");
+	if (!e) {
+		e = elevator_get(CONFIG_DEFAULT_IOSCHED);
+		if (!e) {
+			printk(KERN_ERR
+				"Default I/O scheduler not found. " \
+				"Using noop.\n");
+			e = elevator_get("noop");
+		}
 	}
 
 	eq = elevator_alloc(q, e);
@@ -248,7 +276,6 @@ int elevator_init(struct request_queue *q, char *name)
 	elevator_attach(q, eq, data);
 	return ret;
 }
-
 EXPORT_SYMBOL(elevator_init);
 
 void elevator_exit(elevator_t *e)
@@ -261,7 +288,6 @@ void elevator_exit(elevator_t *e)
 
 	kobject_put(&e->kobj);
 }
-
 EXPORT_SYMBOL(elevator_exit);
 
 static void elv_activate_rq(struct request_queue *q, struct request *rq)
@@ -353,7 +379,6 @@ struct request *elv_rb_add(struct rb_root *root, struct request *rq)
 	rb_insert_color(&rq->rb_node, root);
 	return NULL;
 }
-
 EXPORT_SYMBOL(elv_rb_add);
 
 void elv_rb_del(struct rb_root *root, struct request *rq)
@@ -362,7 +387,6 @@ void elv_rb_del(struct rb_root *root, struct request *rq)
 	rb_erase(&rq->rb_node, root);
 	RB_CLEAR_NODE(&rq->rb_node);
 }
-
 EXPORT_SYMBOL(elv_rb_del);
 
 struct request *elv_rb_find(struct rb_root *root, sector_t sector)
@@ -383,7 +407,6 @@ struct request *elv_rb_find(struct rb_root *root, sector_t sector)
 
 	return NULL;
 }
-
 EXPORT_SYMBOL(elv_rb_find);
 
 /*
@@ -395,6 +418,7 @@ void elv_dispatch_sort(struct request_queue *q, struct request *rq)
 {
 	sector_t boundary;
 	struct list_head *entry;
+	int stop_flags;
 
 	if (q->last_merge == rq)
 		q->last_merge = NULL;
@@ -404,13 +428,13 @@ void elv_dispatch_sort(struct request_queue *q, struct request *rq)
 	q->nr_sorted--;
 
 	boundary = q->end_sector;
-
+	stop_flags = REQ_SOFTBARRIER | REQ_HARDBARRIER | REQ_STARTED;
 	list_for_each_prev(entry, &q->queue_head) {
 		struct request *pos = list_entry_rq(entry);
 
 		if (rq_data_dir(rq) != rq_data_dir(pos))
 			break;
-		if (pos->cmd_flags & (REQ_SOFTBARRIER|REQ_HARDBARRIER|REQ_STARTED))
+		if (pos->cmd_flags & stop_flags)
 			break;
 		if (rq->sector >= boundary) {
 			if (pos->sector < boundary)
@@ -425,7 +449,6 @@ void elv_dispatch_sort(struct request_queue *q, struct request *rq)
 
 	list_add(&rq->queuelist, entry);
 }
-
 EXPORT_SYMBOL(elv_dispatch_sort);
 
 /*
@@ -446,7 +469,6 @@ void elv_dispatch_add_tail(struct request_queue *q, struct request *rq)
 	q->boundary_rq = rq;
 	list_add_tail(&rq->queuelist, &q->queue_head);
 }
-
 EXPORT_SYMBOL(elv_dispatch_add_tail);
 
 int elv_merge(struct request_queue *q, struct request **req, struct bio *bio)
@@ -466,6 +488,9 @@ int elv_merge(struct request_queue *q, struct request **req, struct bio *bio)
 		}
 	}
 
+	if (blk_queue_nomerges(q))
+		return ELEVATOR_NO_MERGE;
+
 	/*
 	 * See if our hash lookup can find a potential backmerge.
 	 */
@@ -665,7 +690,8 @@ void __elv_add_request(struct request_queue *q, struct request *rq, int where,
 			q->end_sector = rq_end_sector(rq);
 			q->boundary_rq = rq;
 		}
-	} else if (!(rq->cmd_flags & REQ_ELVPRIV) && where == ELEVATOR_INSERT_SORT)
+	} else if (!(rq->cmd_flags & REQ_ELVPRIV) &&
+		    where == ELEVATOR_INSERT_SORT)
 		where = ELEVATOR_INSERT_BACK;
 
 	if (plug)
@@ -673,7 +699,6 @@ void __elv_add_request(struct request_queue *q, struct request *rq, int where,
 
 	elv_insert(q, rq, where);
 }
-
 EXPORT_SYMBOL(__elv_add_request);
 
 void elv_add_request(struct request_queue *q, struct request *rq, int where,
@@ -685,7 +710,6 @@ void elv_add_request(struct request_queue *q, struct request *rq, int where,
 	__elv_add_request(q, rq, where, plug);
 	spin_unlock_irqrestore(q->queue_lock, flags);
 }
-
 EXPORT_SYMBOL(elv_add_request);
 
 static inline struct request *__elv_next_request(struct request_queue *q)
@@ -741,7 +765,21 @@ struct request *elv_next_request(struct request_queue *q)
 			q->boundary_rq = NULL;
 		}
 
-		if ((rq->cmd_flags & REQ_DONTPREP) || !q->prep_rq_fn)
+		if (rq->cmd_flags & REQ_DONTPREP)
+			break;
+
+		if (q->dma_drain_size && rq->data_len) {
+			/*
+			 * make sure space for the drain appears we
+			 * know we can do this because max_hw_segments
+			 * has been adjusted to be one fewer than the
+			 * device can handle
+			 */
+			rq->nr_phys_segments++;
+			rq->nr_hw_segments++;
+		}
+
+		if (!q->prep_rq_fn)
 			break;
 
 		ret = q->prep_rq_fn(q, rq);
@@ -754,6 +792,16 @@ struct request *elv_next_request(struct request_queue *q)
 			 * avoid resource deadlock.  REQ_STARTED will
 			 * prevent other fs requests from passing this one.
 			 */
+			if (q->dma_drain_size && rq->data_len &&
+			    !(rq->cmd_flags & REQ_DONTPREP)) {
+				/*
+				 * remove the space for the drain we added
+				 * so that we don't add it again
+				 */
+				--rq->nr_phys_segments;
+				--rq->nr_hw_segments;
+			}
+
 			rq = NULL;
 			break;
 		} else if (ret == BLKPREP_KILL) {
@@ -768,7 +816,6 @@ struct request *elv_next_request(struct request_queue *q)
 
 	return rq;
 }
-
 EXPORT_SYMBOL(elv_next_request);
 
 void elv_dequeue_request(struct request_queue *q, struct request *rq)
@@ -786,7 +833,6 @@ void elv_dequeue_request(struct request_queue *q, struct request *rq)
 	if (blk_account_rq(rq))
 		q->in_flight++;
 }
-
 EXPORT_SYMBOL(elv_dequeue_request);
 
 int elv_queue_empty(struct request_queue *q)
@@ -801,7 +847,6 @@ int elv_queue_empty(struct request_queue *q)
 
 	return 1;
 }
-
 EXPORT_SYMBOL(elv_queue_empty);
 
 struct request *elv_latter_request(struct request_queue *q, struct request *rq)
@@ -970,7 +1015,8 @@ void elv_register(struct elevator_type *e)
 			 !strcmp(e->elevator_name, CONFIG_DEFAULT_IOSCHED)))
 				def = " (default)";
 
-	printk(KERN_INFO "io scheduler %s registered%s\n", e->elevator_name, def);
+	printk(KERN_INFO "io scheduler %s registered%s\n", e->elevator_name,
+								def);
 }
 EXPORT_SYMBOL_GPL(elv_register);
 
@@ -1027,7 +1073,7 @@ static int elevator_switch(struct request_queue *q, struct elevator_type *new_e)
 	 */
 	spin_lock_irq(q->queue_lock);
 
-	set_bit(QUEUE_FLAG_ELVSWITCH, &q->queue_flags);
+	queue_flag_set(QUEUE_FLAG_ELVSWITCH, q);
 
 	elv_drain_elevator(q);
 
@@ -1061,7 +1107,10 @@ static int elevator_switch(struct request_queue *q, struct elevator_type *new_e)
 	 * finally exit old elevator and turn off BYPASS.
 	 */
 	elevator_exit(old_elevator);
-	clear_bit(QUEUE_FLAG_ELVSWITCH, &q->queue_flags);
+	spin_lock_irq(q->queue_lock);
+	queue_flag_clear(QUEUE_FLAG_ELVSWITCH, q);
+	spin_unlock_irq(q->queue_lock);
+
 	return 1;
 
 fail_register:
@@ -1072,7 +1121,11 @@ fail_register:
 	elevator_exit(e);
 	q->elevator = old_elevator;
 	elv_register_queue(q);
-	clear_bit(QUEUE_FLAG_ELVSWITCH, &q->queue_flags);
+
+	spin_lock_irq(q->queue_lock);
+	queue_flag_clear(QUEUE_FLAG_ELVSWITCH, q);
+	spin_unlock_irq(q->queue_lock);
+
 	return 0;
 }
 
@@ -1102,7 +1155,8 @@ ssize_t elv_iosched_store(struct request_queue *q, const char *name,
 	}
 
 	if (!elevator_switch(q, e))
-		printk(KERN_ERR "elevator: switch to %s failed\n",elevator_name);
+		printk(KERN_ERR "elevator: switch to %s failed\n",
+							elevator_name);
 	return count;
 }
 
@@ -1136,7 +1190,6 @@ struct request *elv_rb_former_request(struct request_queue *q,
 
 	return NULL;
 }
-
 EXPORT_SYMBOL(elv_rb_former_request);
 
 struct request *elv_rb_latter_request(struct request_queue *q,
@@ -1149,5 +1202,4 @@ struct request *elv_rb_latter_request(struct request_queue *q,
 
 	return NULL;
 }
-
 EXPORT_SYMBOL(elv_rb_latter_request);