*
* Copyright (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE
*
- * 30042000 Jens Axboe <axboe@suse.de> :
+ * 30042000 Jens Axboe <axboe@kernel.dk> :
*
* Split the elevator a bit so that it is possible to choose a different
* one or even write a new "plug in". There are three pieces:
#define rq_hash_key(rq) ((rq)->sector + (rq)->nr_sectors)
#define ELV_ON_HASH(rq) (!hlist_unhashed(&(rq)->hash))
+/*
+ * Query io scheduler to see if the current process issuing bio may be
+ * merged with rq.
+ */
+static int elv_iosched_allow_merge(struct request *rq, struct bio *bio)
+{
+ request_queue_t *q = rq->q;
+ elevator_t *e = q->elevator;
+
+ if (e->ops->elevator_allow_merge_fn)
+ return e->ops->elevator_allow_merge_fn(q, rq, bio);
+
+ return 1;
+}
+
/*
* can we safely merge with this request?
*/
return 0;
/*
- * same device and no special stuff set, merge is ok
+ * must be same device and not a special request
*/
- if (rq->rq_disk == bio->bi_bdev->bd_disk &&
- !rq->waiting && !rq->special)
- return 1;
+ if (rq->rq_disk != bio->bi_bdev->bd_disk || rq->special)
+ return 0;
- return 0;
+ if (!elv_iosched_allow_merge(rq, bio))
+ return 0;
+
+ return 1;
}
EXPORT_SYMBOL(elv_rq_merge_ok);
static struct elevator_type *elevator_find(const char *name)
{
- struct elevator_type *e = NULL;
+ struct elevator_type *e;
struct list_head *entry;
list_for_each(entry, &elv_list) {
- struct elevator_type *__e;
- __e = list_entry(entry, struct elevator_type, list);
+ e = list_entry(entry, struct elevator_type, list);
- if (!strcmp(__e->elevator_name, name)) {
- e = __e;
- break;
- }
+ if (!strcmp(e->elevator_name, name))
+ return e;
}
- return e;
+ return NULL;
}
static void elevator_put(struct elevator_type *e)
static void *elevator_init_queue(request_queue_t *q, struct elevator_queue *eq)
{
- return eq->ops->elevator_init_fn(q, eq);
+ return eq->ops->elevator_init_fn(q);
}
static void elevator_attach(request_queue_t *q, struct elevator_queue *eq,
static struct kobj_type elv_ktype;
-static elevator_t *elevator_alloc(struct elevator_type *e)
+static elevator_t *elevator_alloc(request_queue_t *q, struct elevator_type *e)
{
elevator_t *eq;
int i;
- eq = kmalloc(sizeof(elevator_t), GFP_KERNEL);
+ eq = kmalloc_node(sizeof(elevator_t), GFP_KERNEL, q->node);
if (unlikely(!eq))
goto err;
eq->kobj.ktype = &elv_ktype;
mutex_init(&eq->sysfs_lock);
- eq->hash = kmalloc(sizeof(struct hlist_head) * ELV_HASH_ENTRIES, GFP_KERNEL);
+ eq->hash = kmalloc_node(sizeof(struct hlist_head) * ELV_HASH_ENTRIES,
+ GFP_KERNEL, q->node);
if (!eq->hash)
goto err;
e = elevator_get("noop");
}
- eq = elevator_alloc(e);
+ eq = elevator_alloc(q, e);
if (!eq)
return -ENOMEM;
return ret;
}
+EXPORT_SYMBOL(elevator_init);
+
void elevator_exit(elevator_t *e)
{
mutex_lock(&e->sysfs_lock);
kobject_put(&e->kobj);
}
+EXPORT_SYMBOL(elevator_exit);
+
static inline void __elv_rqhash_del(struct request *rq)
{
hlist_del_init(&rq->hash);
return NULL;
}
+/*
+ * RB-tree support functions for inserting/lookup/removal of requests
+ * in a sorted RB tree.
+ */
+struct request *elv_rb_add(struct rb_root *root, struct request *rq)
+{
+ struct rb_node **p = &root->rb_node;
+ struct rb_node *parent = NULL;
+ struct request *__rq;
+
+ while (*p) {
+ parent = *p;
+ __rq = rb_entry(parent, struct request, rb_node);
+
+ if (rq->sector < __rq->sector)
+ p = &(*p)->rb_left;
+ else if (rq->sector > __rq->sector)
+ p = &(*p)->rb_right;
+ else
+ return __rq;
+ }
+
+ rb_link_node(&rq->rb_node, parent, p);
+ 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)
+{
+ BUG_ON(RB_EMPTY_NODE(&rq->rb_node));
+ 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)
+{
+ struct rb_node *n = root->rb_node;
+ struct request *rq;
+
+ while (n) {
+ rq = rb_entry(n, struct request, rb_node);
+
+ if (sector < rq->sector)
+ n = n->rb_left;
+ else if (sector > rq->sector)
+ n = n->rb_right;
+ else
+ return rq;
+ }
+
+ return NULL;
+}
+
+EXPORT_SYMBOL(elv_rb_find);
+
/*
* Insert rq into dispatch queue of q. Queue lock must be held on
- * entry. If sort != 0, rq is sort-inserted; otherwise, rq will be
- * appended to the dispatch queue. To be used by specific elevators.
+ * entry. rq is sort insted into the dispatch queue. To be used by
+ * specific elevators.
*/
void elv_dispatch_sort(request_queue_t *q, struct request *rq)
{
list_add(&rq->queuelist, entry);
}
+EXPORT_SYMBOL(elv_dispatch_sort);
+
/*
- * This should be in elevator.h, but that requires pulling in rq and q
+ * Insert rq into dispatch queue of q. Queue lock must be held on
+ * entry. rq is added to the back of the dispatch queue. To be used by
+ * specific elevators.
*/
void elv_dispatch_add_tail(struct request_queue *q, struct request *rq)
{
list_add_tail(&rq->queuelist, &q->queue_head);
}
+EXPORT_SYMBOL(elv_dispatch_add_tail);
+
int elv_merge(request_queue_t *q, struct request **req, struct bio *bio)
{
elevator_t *e = q->elevator;
return ELEVATOR_NO_MERGE;
}
-void elv_merged_request(request_queue_t *q, struct request *rq)
+void elv_merged_request(request_queue_t *q, struct request *rq, int type)
{
elevator_t *e = q->elevator;
if (e->ops->elevator_merged_fn)
- e->ops->elevator_merged_fn(q, rq);
+ e->ops->elevator_merged_fn(q, rq, type);
- elv_rqhash_reposition(q, rq);
+ if (type == ELEVATOR_BACK_MERGE)
+ elv_rqhash_reposition(q, rq);
q->last_merge = rq;
}
elv_insert(q, rq, where);
}
+EXPORT_SYMBOL(__elv_add_request);
+
void elv_add_request(request_queue_t *q, struct request *rq, int where,
int plug)
{
spin_unlock_irqrestore(q->queue_lock, flags);
}
+EXPORT_SYMBOL(elv_add_request);
+
static inline struct request *__elv_next_request(request_queue_t *q)
{
struct request *rq;
return rq;
}
+EXPORT_SYMBOL(elv_next_request);
+
void elv_dequeue_request(request_queue_t *q, struct request *rq)
{
BUG_ON(list_empty(&rq->queuelist));
q->in_flight++;
}
+EXPORT_SYMBOL(elv_dequeue_request);
+
int elv_queue_empty(request_queue_t *q)
{
elevator_t *e = q->elevator;
return 1;
}
+EXPORT_SYMBOL(elv_queue_empty);
+
struct request *elv_latter_request(request_queue_t *q, struct request *rq)
{
elevator_t *e = q->elevator;
return NULL;
}
-int elv_set_request(request_queue_t *q, struct request *rq, struct bio *bio,
- gfp_t gfp_mask)
+int elv_set_request(request_queue_t *q, struct request *rq, gfp_t gfp_mask)
{
elevator_t *e = q->elevator;
if (e->ops->elevator_set_req_fn)
- return e->ops->elevator_set_req_fn(q, rq, bio, gfp_mask);
+ return e->ops->elevator_set_req_fn(q, rq, gfp_mask);
rq->elevator_private = NULL;
return 0;
elevator_t *e = q->elevator;
if (e->ops->elevator_put_req_fn)
- e->ops->elevator_put_req_fn(q, rq);
+ e->ops->elevator_put_req_fn(rq);
}
-int elv_may_queue(request_queue_t *q, int rw, struct bio *bio)
+int elv_may_queue(request_queue_t *q, int rw)
{
elevator_t *e = q->elevator;
if (e->ops->elevator_may_queue_fn)
- return e->ops->elevator_may_queue_fn(q, rw, bio);
+ return e->ops->elevator_may_queue_fn(q, rw);
return ELV_MQUEUE_MAY;
}
/*
* Allocate new elevator
*/
- e = elevator_alloc(new_e);
+ e = elevator_alloc(q, new_e);
if (!e)
return 0;
struct list_head *entry;
int len = 0;
- spin_lock_irq(q->queue_lock);
+ spin_lock_irq(&elv_list_lock);
list_for_each(entry, &elv_list) {
struct elevator_type *__e;
else
len += sprintf(name+len, "%s ", __e->elevator_name);
}
- spin_unlock_irq(q->queue_lock);
+ spin_unlock_irq(&elv_list_lock);
len += sprintf(len+name, "\n");
return len;
}
-EXPORT_SYMBOL(elv_dispatch_sort);
-EXPORT_SYMBOL(elv_add_request);
-EXPORT_SYMBOL(__elv_add_request);
-EXPORT_SYMBOL(elv_next_request);
-EXPORT_SYMBOL(elv_dequeue_request);
-EXPORT_SYMBOL(elv_queue_empty);
-EXPORT_SYMBOL(elevator_exit);
-EXPORT_SYMBOL(elevator_init);
+struct request *elv_rb_former_request(request_queue_t *q, struct request *rq)
+{
+ struct rb_node *rbprev = rb_prev(&rq->rb_node);
+
+ if (rbprev)
+ return rb_entry_rq(rbprev);
+
+ return NULL;
+}
+
+EXPORT_SYMBOL(elv_rb_former_request);
+
+struct request *elv_rb_latter_request(request_queue_t *q, struct request *rq)
+{
+ struct rb_node *rbnext = rb_next(&rq->rb_node);
+
+ if (rbnext)
+ return rb_entry_rq(rbnext);
+
+ return NULL;
+}
+
+EXPORT_SYMBOL(elv_rb_latter_request);
git.openpandora.org / pandora-kernel.git / blobdiff