Merge branch 'for-3.9/core' of git://git.kernel.dk/linux-block

Pull block IO core bits from Jens Axboe:
 "Below are the core block IO bits for 3.9.  It was delayed a few days
  since my workstation kept crashing every 2-8h after pulling it into
  current -git, but turns out it is a bug in the new pstate code (divide
  by zero, will report separately).  In any case, it contains:

   - The big cfq/blkcg update from Tejun and and Vivek.

   - Additional block and writeback tracepoints from Tejun.

   - Improvement of the should sort (based on queues) logic in the plug
     flushing.

   - _io() variants of the wait_for_completion() interface, using
     io_schedule() instead of schedule() to contribute to io wait
     properly.

   - Various little fixes.

  You'll get two trivial merge conflicts, which should be easy enough to
  fix up"

Fix up the trivial conflicts due to hlist traversal cleanups (commit
b67bfe0d42ca: "hlist: drop the node parameter from iterators").

* 'for-3.9/core' of git://git.kernel.dk/linux-block: (39 commits)
  block: remove redundant check to bd_openers()
  block: use i_size_write() in bd_set_size()
  cfq: fix lock imbalance with failed allocations
  drivers/block/swim3.c: fix null pointer dereference
  block: don't select PERCPU_RWSEM
  block: account iowait time when waiting for completion of IO request
  sched: add wait_for_completion_io[_timeout]
  writeback: add more tracepoints
  block: add block_{touch|dirty}_buffer tracepoint
  buffer: make touch_buffer() an exported function
  block: add @req to bio_{front|back}_merge tracepoints
  block: add missing block_bio_complete() tracepoint
  block: Remove should_sort judgement when flush blk_plug
  block,elevator: use new hashtable implementation
  cfq-iosched: add hierarchical cfq_group statistics
  cfq-iosched: collect stats from dead cfqgs
  cfq-iosched: separate out cfqg_stats_reset() from cfq_pd_reset_stats()
  blkcg: make blkcg_print_blkgs() grab q locks instead of blkcg lock
  block: RCU free request_queue
  blkcg: implement blkg_[rw]stat_recursive_sum() and blkg_[rw]stat_merge()
  ...

1 files changed, 4 insertions, 19 deletions

diff --git a/block/elevator.c b/block/elevator.c
index d0acb31cc083..a0ffdd943c98 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -46,11 +46,6 @@ static LIST_HEAD(elv_list);
 /*
  * 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))
 
 /*
@@ -158,7 +153,6 @@ static 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))
@@ -167,14 +161,7 @@ static struct elevator_queue *elevator_alloc(struct request_queue *q,
         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:
@@ -189,7 +176,6 @@ static void elevator_release(struct kobject *kobj)
 
         e = container_of(kobj, struct elevator_queue, kobj);
         elevator_put(e->type);
-        kfree(e->hash);
         kfree(e);
 }
 
@@ -261,7 +247,7 @@ EXPORT_SYMBOL(elevator_exit);
 
 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)
@@ -275,7 +261,7 @@ static void elv_rqhash_add(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)
@@ -287,11 +273,10 @@ 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 *next;
         struct request *rq;
 
-        hlist_for_each_entry_safe(rq, 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))) {