block: Fix double put in blk_integrity_unregister
[safe/jmp/linux-2.6] / block / elevator.c
index e452deb..0451892 100644 (file)
@@ -34,8 +34,9 @@
 #include <linux/delay.h>
 #include <linux/blktrace_api.h>
 #include <linux/hash.h>
+#include <linux/uaccess.h>
 
-#include <asm/uaccess.h>
+#include "blk.h"
 
 static DEFINE_SPINLOCK(elv_list_lock);
 static LIST_HEAD(elv_list);
@@ -45,7 +46,8 @@ 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))
@@ -68,12 +70,18 @@ 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;
 
        /*
+        * Don't merge file system requests and discard requests
+        */
+       if (bio_discard(bio) != bio_discard(rq->bio))
+               return 0;
+
+       /*
         * different data direction or already started, don't merge
         */
        if (bio_data_dir(bio) != rq_data_dir(rq))
@@ -85,6 +93,12 @@ inline int elv_rq_merge_ok(struct request *rq, struct bio *bio)
        if (rq->rq_disk != bio->bi_bdev->bd_disk || rq->special)
                return 0;
 
+       /*
+        * only merge integrity protected bio into ditto rq
+        */
+       if (bio_integrity(bio) != blk_integrity_rq(rq))
+               return 0;
+
        if (!elv_iosched_allow_merge(rq, bio))
                return 0;
 
@@ -133,6 +147,21 @@ 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("%s", elv);
+               spin_lock(&elv_list_lock);
+               e = elevator_find(name);
+       }
+
        if (e && !try_module_get(e->elevator_owner))
                e = NULL;
 
@@ -185,9 +214,7 @@ 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 +253,27 @@ 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 +289,6 @@ 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 +301,6 @@ 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 +392,6 @@ 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 +400,6 @@ 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)
@@ -385,7 +420,6 @@ struct request *elv_rb_find(struct rb_root *root, sector_t sector)
 
        return NULL;
 }
-
 EXPORT_SYMBOL(elv_rb_find);
 
 /*
@@ -397,6 +431,7 @@ 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;
@@ -406,13 +441,15 @@ 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 (blk_discard_rq(rq) != blk_discard_rq(pos))
+                       break;
                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 +464,6 @@ void elv_dispatch_sort(struct request_queue *q, struct request *rq)
 
        list_add(&rq->queuelist, entry);
 }
-
 EXPORT_SYMBOL(elv_dispatch_sort);
 
 /*
@@ -448,7 +484,6 @@ 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)
@@ -468,6 +503,9 @@ 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.
         */
@@ -578,7 +616,7 @@ void elv_insert(struct request_queue *q, struct request *rq, int where)
                break;
 
        case ELEVATOR_INSERT_SORT:
-               BUG_ON(!blk_fs_request(rq));
+               BUG_ON(!blk_fs_request(rq) && !blk_discard_rq(rq));
                rq->cmd_flags |= REQ_SORTED;
                q->nr_sorted++;
                if (rq_mergeable(rq)) {
@@ -627,7 +665,7 @@ void elv_insert(struct request_queue *q, struct request *rq, int where)
 
        default:
                printk(KERN_ERR "%s: bad insertion point %d\n",
-                      __FUNCTION__, where);
+                      __func__, where);
                BUG();
        }
 
@@ -663,11 +701,12 @@ void __elv_add_request(struct request_queue *q, struct request *rq, int where,
                 * this request is scheduling boundary, update
                 * end_sector
                 */
-               if (blk_fs_request(rq)) {
+               if (blk_fs_request(rq) || blk_discard_rq(rq)) {
                        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 +714,6 @@ 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 +725,6 @@ 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)
@@ -717,7 +754,7 @@ struct request *elv_next_request(struct request_queue *q)
                 * not ever see it.
                 */
                if (blk_empty_barrier(rq)) {
-                       end_queued_request(rq, 1);
+                       __blk_end_request(rq, 0, blk_rq_bytes(rq));
                        continue;
                }
                if (!(rq->cmd_flags & REQ_STARTED)) {
@@ -736,6 +773,12 @@ struct request *elv_next_request(struct request_queue *q)
                         */
                        rq->cmd_flags |= REQ_STARTED;
                        blk_add_trace_rq(q, rq, BLK_TA_ISSUE);
+
+                       /*
+                        * We are now handing the request to the hardware,
+                        * add the timeout handler
+                        */
+                       blk_add_timer(rq);
                }
 
                if (!q->boundary_rq || q->boundary_rq == rq) {
@@ -743,7 +786,20 @@ 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++;
+               }
+
+               if (!q->prep_rq_fn)
                        break;
 
                ret = q->prep_rq_fn(q, rq);
@@ -756,21 +812,28 @@ 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 = NULL;
                        break;
                } else if (ret == BLKPREP_KILL) {
                        rq->cmd_flags |= REQ_QUIET;
-                       end_queued_request(rq, 0);
+                       __blk_end_request(rq, -EIO, blk_rq_bytes(rq));
                } else {
-                       printk(KERN_ERR "%s: bad return=%d\n", __FUNCTION__,
-                                                               ret);
+                       printk(KERN_ERR "%s: bad return=%d\n", __func__, ret);
                        break;
                }
        }
 
        return rq;
 }
-
 EXPORT_SYMBOL(elv_next_request);
 
 void elv_dequeue_request(struct request_queue *q, struct request *rq)
@@ -788,7 +851,6 @@ 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 +865,6 @@ 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)
@@ -853,6 +914,19 @@ int elv_may_queue(struct request_queue *q, int rw)
        return ELV_MQUEUE_MAY;
 }
 
+void elv_abort_queue(struct request_queue *q)
+{
+       struct request *rq;
+
+       while (!list_empty(&q->queue_head)) {
+               rq = list_entry_rq(q->queue_head.next);
+               rq->cmd_flags |= REQ_QUIET;
+               blk_add_trace_rq(q, rq, BLK_TA_ABORT);
+               __blk_end_request(rq, -EIO, blk_rq_bytes(rq));
+       }
+}
+EXPORT_SYMBOL(elv_abort_queue);
+
 void elv_completed_request(struct request_queue *q, struct request *rq)
 {
        elevator_t *e = q->elevator;
@@ -931,9 +1005,7 @@ 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) {
@@ -974,7 +1046,8 @@ 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);
 
@@ -1031,7 +1104,7 @@ 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);
 
@@ -1065,7 +1138,12 @@ 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);
+
+       blk_add_trace_msg(q, "elv switch: %s", e->elevator_type->elevator_name);
+
        return 1;
 
 fail_register:
@@ -1076,7 +1154,11 @@ 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;
 }
 
@@ -1106,7 +1188,8 @@ 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;
 }
 
@@ -1140,7 +1223,6 @@ 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,
@@ -1153,5 +1235,4 @@ struct request *elv_rb_latter_request(struct request_queue *q,
 
        return NULL;
 }
-
 EXPORT_SYMBOL(elv_rb_latter_request);