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, 3 insertions, 15 deletions

diff --git a/block/blk-core.c b/block/blk-core.c
index 277134cb5d32..074b758efc42 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -39,7 +39,6 @@
 
 EXPORT_TRACEPOINT_SYMBOL_GPL(block_bio_remap);
 EXPORT_TRACEPOINT_SYMBOL_GPL(block_rq_remap);
-EXPORT_TRACEPOINT_SYMBOL_GPL(block_bio_complete);
 EXPORT_TRACEPOINT_SYMBOL_GPL(block_unplug);
 
 DEFINE_IDA(blk_queue_ida);
@@ -1348,7 +1347,7 @@ static bool bio_attempt_back_merge(struct request_queue *q, struct request *req,
         if (!ll_back_merge_fn(q, req, bio))
                 return false;
 
-        trace_block_bio_backmerge(q, bio);
+        trace_block_bio_backmerge(q, req, bio);
 
         if ((req->cmd_flags & REQ_FAILFAST_MASK) != ff)
                 blk_rq_set_mixed_merge(req);
@@ -1370,7 +1369,7 @@ static bool bio_attempt_front_merge(struct request_queue *q,
         if (!ll_front_merge_fn(q, req, bio))
                 return false;
 
-        trace_block_bio_frontmerge(q, bio);
+        trace_block_bio_frontmerge(q, req, bio);
 
         if ((req->cmd_flags & REQ_FAILFAST_MASK) != ff)
                 blk_rq_set_mixed_merge(req);
@@ -1553,13 +1552,6 @@ get_rq:
                 if (list_empty(&plug->list))
                         trace_block_plug(q);
                 else {
-                        if (!plug->should_sort) {
-                                struct request *__rq;
-
-                                __rq = list_entry_rq(plug->list.prev);
-                                if (__rq->q != q)
-                                        plug->should_sort = 1;
-                        }
                         if (request_count >= BLK_MAX_REQUEST_COUNT) {
                                 blk_flush_plug_list(plug, false);
                                 trace_block_plug(q);
@@ -2890,7 +2882,6 @@ void blk_start_plug(struct blk_plug *plug)
         plug->magic = PLUG_MAGIC;
         INIT_LIST_HEAD(&plug->list);
         INIT_LIST_HEAD(&plug->cb_list);
-        plug->should_sort = 0;
 
         /*
          * If this is a nested plug, don't actually assign it. It will be
@@ -2992,10 +2983,7 @@ void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule)
 
         list_splice_init(&plug->list, &list);
 
-        if (plug->should_sort) {
-                list_sort(NULL, &list, plug_rq_cmp);
-                plug->should_sort = 0;
-        }
+        list_sort(NULL, &list, plug_rq_cmp);
 
         q = NULL;
         depth = 0;