Merge commit 'v2.6.39' into for-2.6.40/core

Since for-2.6.40/core was forked off the 2.6.39 devel tree, we've
had churn in the core area that makes it difficult to handle
patches for eg cfq or blk-throttle. Instead of requiring that they
be based in older versions with bugs that have been fixed later
in the rc cycle, merge in 2.6.39 final.

Also fixes up conflicts in the below files.

Conflicts:
	drivers/block/paride/pcd.c
	drivers/cdrom/viocd.c
	drivers/ide/ide-cd.c

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

9 files changed, 43 insertions, 44 deletions

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index f0605ab2a76..471fdcc5df8 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -114,6 +114,13 @@ struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup)
 }
 EXPORT_SYMBOL_GPL(cgroup_to_blkio_cgroup);
 
+struct blkio_cgroup *task_blkio_cgroup(struct task_struct *tsk)
+{
+	return container_of(task_subsys_state(tsk, blkio_subsys_id),
+			    struct blkio_cgroup, css);
+}
+EXPORT_SYMBOL_GPL(task_blkio_cgroup);
+
 static inline void
 blkio_update_group_weight(struct blkio_group *blkg, unsigned int weight)
 {
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index 10919fae2d3..c774930cc20 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -291,6 +291,7 @@ static inline void blkiocg_set_start_empty_time(struct blkio_group *blkg) {}
 #if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE)
 extern struct blkio_cgroup blkio_root_cgroup;
 extern struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup);
+extern struct blkio_cgroup *task_blkio_cgroup(struct task_struct *tsk);
 extern void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
 	struct blkio_group *blkg, void *key, dev_t dev,
 	enum blkio_policy_id plid);
@@ -314,6 +315,8 @@ void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
 struct cgroup;
 static inline struct blkio_cgroup *
 cgroup_to_blkio_cgroup(struct cgroup *cgroup) { return NULL; }
+static inline struct blkio_cgroup *
+task_blkio_cgroup(struct task_struct *tsk) { return NULL; }
 
 static inline void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
 		struct blkio_group *blkg, void *key, dev_t dev,
diff --git a/block/blk-core.c b/block/blk-core.c
index 5fa3dd2705c..3fe00a14822 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -292,7 +292,6 @@ EXPORT_SYMBOL(blk_sync_queue);
 /**
  * __blk_run_queue - run a single device queue
  * @q:	The queue to run
- * @force_kblockd: Don't run @q->request_fn directly.  Use kblockd.
  *
  * Description:
  *    See @blk_run_queue. This variant must be called with the queue lock
@@ -303,15 +302,7 @@ void __blk_run_queue(struct request_queue *q)
 	if (unlikely(blk_queue_stopped(q)))
 		return;
 
-	/*
-	 * Only recurse once to avoid overrunning the stack, let the unplug
-	 * handling reinvoke the handler shortly if we already got there.
-	 */
-	if (!queue_flag_test_and_set(QUEUE_FLAG_REENTER, q)) {
-		q->request_fn(q);
-		queue_flag_clear(QUEUE_FLAG_REENTER, q);
-	} else
-		queue_delayed_work(kblockd_workqueue, &q->delay_work, 0);
+	q->request_fn(q);
 }
 EXPORT_SYMBOL(__blk_run_queue);
 
@@ -325,9 +316,12 @@ EXPORT_SYMBOL(__blk_run_queue);
  */
 void blk_run_queue_async(struct request_queue *q)
 {
-	if (likely(!blk_queue_stopped(q)))
+	if (likely(!blk_queue_stopped(q))) {
+		__cancel_delayed_work(&q->delay_work);
 		queue_delayed_work(kblockd_workqueue, &q->delay_work, 0);
+	}
 }
+EXPORT_SYMBOL(blk_run_queue_async);
 
 /**
  * blk_run_queue - run a single device queue
@@ -2787,7 +2781,6 @@ void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule)
 
 	local_irq_restore(flags);
 }
-EXPORT_SYMBOL(blk_flush_plug_list);
 
 void blk_finish_plug(struct blk_plug *plug)
 {
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 53bd0c77bfd..d935bd859c8 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -66,14 +66,14 @@ queue_requests_store(struct request_queue *q, const char *page, size_t count)
 
 	if (rl->count[BLK_RW_SYNC] >= q->nr_requests) {
 		blk_set_queue_full(q, BLK_RW_SYNC);
-	} else if (rl->count[BLK_RW_SYNC]+1 <= q->nr_requests) {
+	} else {
 		blk_clear_queue_full(q, BLK_RW_SYNC);
 		wake_up(&rl->wait[BLK_RW_SYNC]);
 	}
 
 	if (rl->count[BLK_RW_ASYNC] >= q->nr_requests) {
 		blk_set_queue_full(q, BLK_RW_ASYNC);
-	} else if (rl->count[BLK_RW_ASYNC]+1 <= q->nr_requests) {
+	} else {
 		blk_clear_queue_full(q, BLK_RW_ASYNC);
 		wake_up(&rl->wait[BLK_RW_ASYNC]);
 	}
@@ -509,8 +509,10 @@ int blk_register_queue(struct gendisk *disk)
 		return ret;
 
 	ret = kobject_add(&q->kobj, kobject_get(&dev->kobj), "%s", "queue");
-	if (ret < 0)
+	if (ret < 0) {
+		blk_trace_remove_sysfs(dev);
 		return ret;
+	}
 
 	kobject_uevent(&q->kobj, KOBJ_ADD);
 
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 0475a22a420..252a81a306f 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -160,9 +160,8 @@ static void throtl_put_tg(struct throtl_grp *tg)
 }
 
 static struct throtl_grp * throtl_find_alloc_tg(struct throtl_data *td,
-			struct cgroup *cgroup)
+			struct blkio_cgroup *blkcg)
 {
-	struct blkio_cgroup *blkcg = cgroup_to_blkio_cgroup(cgroup);
 	struct throtl_grp *tg = NULL;
 	void *key = td;
 	struct backing_dev_info *bdi = &td->queue->backing_dev_info;
@@ -229,12 +228,12 @@ done:
 
 static struct throtl_grp * throtl_get_tg(struct throtl_data *td)
 {
-	struct cgroup *cgroup;
 	struct throtl_grp *tg = NULL;
+	struct blkio_cgroup *blkcg;
 
 	rcu_read_lock();
-	cgroup = task_cgroup(current, blkio_subsys_id);
-	tg = throtl_find_alloc_tg(td, cgroup);
+	blkcg = task_blkio_cgroup(current);
+	tg = throtl_find_alloc_tg(td, blkcg);
 	if (!tg)
 		tg = &td->root_tg;
 	rcu_read_unlock();
diff --git a/block/blk.h b/block/blk.h
index 83e4bff3620..1f798b5a6f1 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -22,7 +22,6 @@ void blk_rq_timed_out_timer(unsigned long data);
 void blk_delete_timer(struct request *);
 void blk_add_timer(struct request *);
 void __generic_unplug_device(struct request_queue *);
-void blk_run_queue_async(struct request_queue *q);
 
 /*
  * Internal atomic flags for request handling
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 46b0a1d1d92..ab7a9e6a9b1 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -1014,10 +1014,9 @@ void cfq_update_blkio_group_weight(void *key, struct blkio_group *blkg,
 	cfqg->needs_update = true;
 }
 
-static struct cfq_group *
-cfq_find_alloc_cfqg(struct cfq_data *cfqd, struct cgroup *cgroup, int create)
+static struct cfq_group * cfq_find_alloc_cfqg(struct cfq_data *cfqd,
+		struct blkio_cgroup *blkcg, int create)
 {
-	struct blkio_cgroup *blkcg = cgroup_to_blkio_cgroup(cgroup);
 	struct cfq_group *cfqg = NULL;
 	void *key = cfqd;
 	int i, j;
@@ -1079,12 +1078,12 @@ done:
  */
 static struct cfq_group *cfq_get_cfqg(struct cfq_data *cfqd, int create)
 {
-	struct cgroup *cgroup;
+	struct blkio_cgroup *blkcg;
 	struct cfq_group *cfqg = NULL;
 
 	rcu_read_lock();
-	cgroup = task_cgroup(current, blkio_subsys_id);
-	cfqg = cfq_find_alloc_cfqg(cfqd, cgroup, create);
+	blkcg = task_blkio_cgroup(current);
+	cfqg = cfq_find_alloc_cfqg(cfqd, blkcg, create);
 	if (!cfqg && create)
 		cfqg = &cfqd->root_group;
 	rcu_read_unlock();
@@ -2582,28 +2581,20 @@ static void cfq_put_queue(struct cfq_queue *cfqq)
 }
 
 /*
- * Must always be called with the rcu_read_lock() held
+ * Call func for each cic attached to this ioc.
  */
 static void
-__call_for_each_cic(struct io_context *ioc,
-		    void (*func)(struct io_context *, struct cfq_io_context *))
+call_for_each_cic(struct io_context *ioc,
+		  void (*func)(struct io_context *, struct cfq_io_context *))
 {
 	struct cfq_io_context *cic;
 	struct hlist_node *n;
 
+	rcu_read_lock();
+
 	hlist_for_each_entry_rcu(cic, n, &ioc->cic_list, cic_list)
 		func(ioc, cic);
-}
 
-/*
- * Call func for each cic attached to this ioc.
- */
-static void
-call_for_each_cic(struct io_context *ioc,
-		  void (*func)(struct io_context *, struct cfq_io_context *))
-{
-	rcu_read_lock();
-	__call_for_each_cic(ioc, func);
 	rcu_read_unlock();
 }
 
@@ -2664,7 +2655,7 @@ static void cfq_free_io_context(struct io_context *ioc)
 	 * should be ok to iterate over the known list, we will see all cic's
 	 * since no new ones are added.
 	 */
-	__call_for_each_cic(ioc, cic_free_func);
+	call_for_each_cic(ioc, cic_free_func);
 }
 
 static void cfq_put_cooperator(struct cfq_queue *cfqq)
diff --git a/block/elevator.c b/block/elevator.c
index 3cd0d8c8490..2a0b653c90f 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -666,7 +666,8 @@ void __elv_add_request(struct request_queue *q, struct request *rq, int where)
 			q->boundary_rq = rq;
 		}
 	} else if (!(rq->cmd_flags & REQ_ELVPRIV) &&
-		    where == ELEVATOR_INSERT_SORT)
+		    (where == ELEVATOR_INSERT_SORT ||
+		     where == ELEVATOR_INSERT_SORT_MERGE))
 		where = ELEVATOR_INSERT_BACK;
 
 	switch (where) {
diff --git a/block/genhd.c b/block/genhd.c
index b364bd038a1..2dd988723d7 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -1588,9 +1588,13 @@ static void disk_events_workfn(struct work_struct *work)
 
 	spin_unlock_irq(&ev->lock);
 
-	/* tell userland about new events */
+	/*
+	 * Tell userland about new events.  Only the events listed in
+	 * @disk->events are reported.  Unlisted events are processed the
+	 * same internally but never get reported to userland.
+	 */
 	for (i = 0; i < ARRAY_SIZE(disk_uevents); i++)
-		if (events & (1 << i))
+		if (events & disk->events & (1 << i))
 			envp[nr_events++] = disk_uevents[i];
 
 	if (nr_events)