X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=block%2Felevator.c;h=bafbae0344d319e909e3e7add07467b1c0463a73;hb=4eb166d9874b4917d79ccd14577a60d795a0cb4a;hp=952aee04a68ad7cc240b8ecb7a8a0e1590b9a33f;hpb=fe2520094d88018423dfc42b3cd0015f74e8adea;p=linux-2.6-omap-h63xx.git

diff --git a/block/elevator.c b/block/elevator.c
index 952aee04a68..bafbae0344d 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))
@@ -185,9 +186,7 @@ static elevator_t *elevator_alloc(struct request_queue *q,
 
 	eq->ops = &e->ops;
 	eq->elevator_type = e;
-	kobject_init(&eq->kobj);
-	kobject_set_name(&eq->kobj, "%s", "iosched");
-	eq->kobj.ktype = &elv_ktype;
+	kobject_init(&eq->kobj, &elv_ktype);
 	mutex_init(&eq->sysfs_lock);
 
 	eq->hash = kmalloc_node(sizeof(struct hlist_head) * ELV_HASH_ENTRIES,
@@ -226,15 +225,27 @@ 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);
@@ -250,7 +261,6 @@ 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)
@@ -263,7 +273,6 @@ 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)
@@ -355,7 +364,6 @@ 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)
@@ -364,7 +372,6 @@ 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)
@@ -385,18 +392,18 @@ struct request *elv_rb_find(struct rb_root *root, sector_t sector)
 
 	return NULL;
 }
-
 EXPORT_SYMBOL(elv_rb_find);
 
 /*
  * Insert rq into dispatch queue of q.  Queue lock must be held on
- * entry.  rq is sort insted into the dispatch queue. To be used by
+ * entry.  rq is sort instead into the dispatch queue. To be used by
  * specific elevators.
  */
 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;
@@ -406,13 +413,13 @@ 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)
@@ -427,7 +434,6 @@ void elv_dispatch_sort(struct request_queue *q, struct request *rq)
 
 	list_add(&rq->queuelist, entry);
 }
-
 EXPORT_SYMBOL(elv_dispatch_sort);
 
 /*
@@ -448,7 +454,6 @@ 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)
@@ -667,7 +672,8 @@ 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)
@@ -675,7 +681,6 @@ 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,
@@ -687,7 +692,6 @@ 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)
@@ -743,7 +747,21 @@ 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);
@@ -756,6 +774,16 @@ 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) {
@@ -770,7 +798,6 @@ 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)
@@ -788,7 +815,6 @@ 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)
@@ -803,7 +829,6 @@ 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)
@@ -931,9 +956,7 @@ int elv_register_queue(struct request_queue *q)
 	elevator_t *e = q->elevator;
 	int error;
 
-	e->kobj.parent = &q->kobj;
-
-	error = kobject_add(&e->kobj);
+	error = kobject_add(&e->kobj, &q->kobj, "%s", "iosched");
 	if (!error) {
 		struct elv_fs_entry *attr = e->elevator_type->elevator_attrs;
 		if (attr) {
@@ -960,7 +983,7 @@ void elv_unregister_queue(struct request_queue *q)
 		__elv_unregister_queue(q->elevator);
 }
 
-int elv_register(struct elevator_type *e)
+void elv_register(struct elevator_type *e)
 {
 	char *def = "";
 
@@ -974,8 +997,8 @@ int 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);
-	return 0;
+	printk(KERN_INFO "io scheduler %s registered%s\n", e->elevator_name,
+								def);
 }
 EXPORT_SYMBOL_GPL(elv_register);
 
@@ -1107,7 +1130,8 @@ 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;
 }
 
@@ -1141,7 +1165,6 @@ 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,
@@ -1154,5 +1177,4 @@ struct request *elv_rb_latter_request(struct request_queue *q,
 
 	return NULL;
 }
-
 EXPORT_SYMBOL(elv_rb_latter_request);