#include <linux/blktrace_api.h>
#include <linux/hash.h>
#include <linux/uaccess.h>
+#include <linux/pm_runtime.h>
#include <trace/events/block.h>
/*
* Merge hash stuff.
*/
-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_ENTRIES (1 << elv_hash_shift)
#define rq_hash_key(rq) (blk_rq_pos(rq) + blk_rq_sectors(rq))
/*
module_put(e->elevator_owner);
}
-static struct elevator_type *elevator_get(const char *name)
+static struct elevator_type *elevator_get(const char *name, bool try_loading)
{
struct elevator_type *e;
spin_lock(&elv_list_lock);
e = elevator_find(name);
- if (!e) {
+ if (!e && try_loading) {
spin_unlock(&elv_list_lock);
request_module("%s-iosched", name);
spin_lock(&elv_list_lock);
__setup("elevator=", elevator_setup);
+/* called during boot to load the elevator chosen by the elevator param */
+void __init load_default_elevator_module(void)
+{
+ struct elevator_type *e;
+
+ if (!chosen_elevator[0])
+ return;
+
+ spin_lock(&elv_list_lock);
+ e = elevator_find(chosen_elevator);
+ spin_unlock(&elv_list_lock);
+
+ if (!e)
+ request_module("%s-iosched", chosen_elevator);
+}
+
static struct kobj_type elv_ktype;
-static struct elevator_queue *elevator_alloc(struct request_queue *q,
+struct elevator_queue *elevator_alloc(struct request_queue *q,
struct elevator_type *e)
{
struct elevator_queue *eq;
- int i;
eq = kmalloc_node(sizeof(*eq), GFP_KERNEL | __GFP_ZERO, q->node);
if (unlikely(!eq))
eq->type = e;
kobject_init(&eq->kobj, &elv_ktype);
mutex_init(&eq->sysfs_lock);
-
- eq->hash = kmalloc_node(sizeof(struct hlist_head) * ELV_HASH_ENTRIES,
- GFP_KERNEL, q->node);
- if (!eq->hash)
- goto err;
-
- for (i = 0; i < ELV_HASH_ENTRIES; i++)
- INIT_HLIST_HEAD(&eq->hash[i]);
+ hash_init(eq->hash);
return eq;
err:
elevator_put(e);
return NULL;
}
+EXPORT_SYMBOL(elevator_alloc);
static void elevator_release(struct kobject *kobj)
{
e = container_of(kobj, struct elevator_queue, kobj);
elevator_put(e->type);
- kfree(e->hash);
kfree(e);
}
struct elevator_type *e = NULL;
int err;
+ /*
+ * q->sysfs_lock must be held to provide mutual exclusion between
+ * elevator_switch() and here.
+ */
+ lockdep_assert_held(&q->sysfs_lock);
+
if (unlikely(q->elevator))
return 0;
q->boundary_rq = NULL;
if (name) {
- e = elevator_get(name);
+ e = elevator_get(name, true);
if (!e)
return -EINVAL;
}
+ /*
+ * Use the default elevator specified by config boot param or
+ * config option. Don't try to load modules as we could be running
+ * off async and request_module() isn't allowed from async.
+ */
if (!e && *chosen_elevator) {
- e = elevator_get(chosen_elevator);
+ e = elevator_get(chosen_elevator, false);
if (!e)
printk(KERN_ERR "I/O scheduler %s not found\n",
chosen_elevator);
}
if (!e) {
- e = elevator_get(CONFIG_DEFAULT_IOSCHED);
+ e = elevator_get(CONFIG_DEFAULT_IOSCHED, false);
if (!e) {
printk(KERN_ERR
"Default I/O scheduler not found. " \
"Using noop.\n");
- e = elevator_get("noop");
+ e = elevator_get("noop", false);
}
}
- q->elevator = elevator_alloc(q, e);
- if (!q->elevator)
- return -ENOMEM;
-
- err = e->ops.elevator_init_fn(q);
- if (err) {
- kobject_put(&q->elevator->kobj);
- return err;
- }
-
+ err = e->ops.elevator_init_fn(q, e);
return 0;
}
EXPORT_SYMBOL(elevator_init);
static inline void __elv_rqhash_del(struct request *rq)
{
- hlist_del_init(&rq->hash);
+ hash_del(&rq->hash);
}
static void elv_rqhash_del(struct request_queue *q, struct request *rq)
struct elevator_queue *e = q->elevator;
BUG_ON(ELV_ON_HASH(rq));
- hlist_add_head(&rq->hash, &e->hash[ELV_HASH_FN(rq_hash_key(rq))]);
+ hash_add(e->hash, &rq->hash, rq_hash_key(rq));
}
static void elv_rqhash_reposition(struct request_queue *q, struct request *rq)
static struct request *elv_rqhash_find(struct request_queue *q, sector_t offset)
{
struct elevator_queue *e = q->elevator;
- struct hlist_head *hash_list = &e->hash[ELV_HASH_FN(offset)];
- struct hlist_node *entry, *next;
+ struct hlist_node *next;
struct request *rq;
- hlist_for_each_entry_safe(rq, entry, next, hash_list, hash) {
+ hash_for_each_possible_safe(e->hash, rq, next, hash, offset) {
BUG_ON(!ELV_ON_HASH(rq));
if (unlikely(!rq_mergeable(rq))) {
struct request *rq)
{
struct request *__rq;
+ bool ret;
if (blk_queue_nomerges(q))
return false;
if (blk_queue_noxmerges(q))
return false;
+ ret = false;
/*
* See if our hash lookup can find a potential backmerge.
*/
- __rq = elv_rqhash_find(q, blk_rq_pos(rq));
- if (__rq && blk_attempt_req_merge(q, __rq, rq))
- return true;
+ while (1) {
+ __rq = elv_rqhash_find(q, blk_rq_pos(rq));
+ if (!__rq || !blk_attempt_req_merge(q, __rq, rq))
+ break;
+
+ /* The merged request could be merged with others, try again */
+ ret = true;
+ rq = __rq;
+ }
- return false;
+ return ret;
}
void elv_merged_request(struct request_queue *q, struct request *rq, int type)
e->type->ops.elevator_bio_merged_fn(q, rq, bio);
}
+#ifdef CONFIG_PM_RUNTIME
+static void blk_pm_requeue_request(struct request *rq)
+{
+ if (rq->q->dev && !(rq->cmd_flags & REQ_PM))
+ rq->q->nr_pending--;
+}
+
+static void blk_pm_add_request(struct request_queue *q, struct request *rq)
+{
+ if (q->dev && !(rq->cmd_flags & REQ_PM) && q->nr_pending++ == 0 &&
+ (q->rpm_status == RPM_SUSPENDED || q->rpm_status == RPM_SUSPENDING))
+ pm_request_resume(q->dev);
+}
+#else
+static inline void blk_pm_requeue_request(struct request *rq) {}
+static inline void blk_pm_add_request(struct request_queue *q,
+ struct request *rq)
+{
+}
+#endif
+
void elv_requeue_request(struct request_queue *q, struct request *rq)
{
/*
rq->cmd_flags &= ~REQ_STARTED;
+ blk_pm_requeue_request(rq);
+
__elv_add_request(q, rq, ELEVATOR_INSERT_REQUEUE);
}
{
trace_block_rq_insert(q, rq);
+ blk_pm_add_request(q, rq);
+
rq->q = q;
if (rq->cmd_flags & REQ_SOFTBARRIER) {
/* barriers are scheduling boundary, update end_sector */
- if (rq->cmd_type == REQ_TYPE_FS ||
- (rq->cmd_flags & REQ_DISCARD)) {
+ if (rq->cmd_type == REQ_TYPE_FS) {
q->end_sector = rq_end_sector(rq);
q->boundary_rq = rq;
}
if (elv_attempt_insert_merge(q, rq))
break;
case ELEVATOR_INSERT_SORT:
- BUG_ON(rq->cmd_type != REQ_TYPE_FS &&
- !(rq->cmd_flags & REQ_DISCARD));
+ BUG_ON(rq->cmd_type != REQ_TYPE_FS);
rq->cmd_flags |= REQ_SORTED;
q->nr_sorted++;
if (rq_mergeable(rq)) {
return NULL;
}
-int elv_set_request(struct request_queue *q, struct request *rq, gfp_t gfp_mask)
+int elv_set_request(struct request_queue *q, struct request *rq,
+ struct bio *bio, gfp_t gfp_mask)
{
struct elevator_queue *e = q->elevator;
if (e->type->ops.elevator_set_req_fn)
- return e->type->ops.elevator_set_req_fn(q, rq, gfp_mask);
+ return e->type->ops.elevator_set_req_fn(q, rq, bio, gfp_mask);
return 0;
}
{
struct elevator_queue *old = q->elevator;
bool registered = old->registered;
- int i, err;
+ int err;
/*
* Turn on BYPASS and drain all requests w/ elevator private data.
ioc_clear_queue(q);
spin_unlock_irq(q->queue_lock);
- for (i = 0; i < BLKIO_NR_POLICIES; i++)
- blkg_destroy_all(q, i, false);
-
/* allocate, init and register new elevator */
- err = -ENOMEM;
- q->elevator = elevator_alloc(q, new_e);
- if (!q->elevator)
+ err = new_e->ops.elevator_init_fn(q, new_e);
+ if (err)
goto fail_init;
- err = new_e->ops.elevator_init_fn(q);
- if (err) {
- kobject_put(&q->elevator->kobj);
- goto fail_init;
- }
-
if (registered) {
err = elv_register_queue(q);
if (err)
return -ENXIO;
strlcpy(elevator_name, name, sizeof(elevator_name));
- e = elevator_get(strstrip(elevator_name));
+ e = elevator_get(strstrip(elevator_name), true);
if (!e) {
printk(KERN_ERR "elevator: type %s not found\n", elevator_name);
return -EINVAL;
Code Review / linux-3.10.git / blobdiff