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-rw-r--r--block/blk-ioc.c4
-rw-r--r--block/cfq-iosched.c19
-rw-r--r--block/genhd.c79
3 files changed, 57 insertions, 45 deletions
diff --git a/block/blk-ioc.c b/block/blk-ioc.c
index bfb0493d12af..6f9bbd978653 100644
--- a/block/blk-ioc.c
+++ b/block/blk-ioc.c
@@ -21,7 +21,7 @@ static void cfq_dtor(struct io_context *ioc)
if (!hlist_empty(&ioc->cic_list)) {
struct cfq_io_context *cic;
- cic = list_entry(ioc->cic_list.first, struct cfq_io_context,
+ cic = hlist_entry(ioc->cic_list.first, struct cfq_io_context,
cic_list);
cic->dtor(ioc);
}
@@ -57,7 +57,7 @@ static void cfq_exit(struct io_context *ioc)
if (!hlist_empty(&ioc->cic_list)) {
struct cfq_io_context *cic;
- cic = list_entry(ioc->cic_list.first, struct cfq_io_context,
+ cic = hlist_entry(ioc->cic_list.first, struct cfq_io_context,
cic_list);
cic->exit(ioc);
}
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 3d403a128971..b2e1c75e4fbe 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -185,7 +185,7 @@ struct cfq_group {
int nr_cfqq;
/*
- * Per group busy queus average. Useful for workload slice calc. We
+ * Per group busy queues average. Useful for workload slice calc. We
* create the array for each prio class but at run time it is used
* only for RT and BE class and slot for IDLE class remains unused.
* This is primarily done to avoid confusion and a gcc warning.
@@ -369,16 +369,16 @@ CFQ_CFQQ_FNS(wait_busy);
#define cfq_log_cfqq(cfqd, cfqq, fmt, args...) \
blk_add_trace_msg((cfqd)->queue, "cfq%d%c %s " fmt, (cfqq)->pid, \
cfq_cfqq_sync((cfqq)) ? 'S' : 'A', \
- blkg_path(&(cfqq)->cfqg->blkg), ##args);
+ blkg_path(&(cfqq)->cfqg->blkg), ##args)
#define cfq_log_cfqg(cfqd, cfqg, fmt, args...) \
blk_add_trace_msg((cfqd)->queue, "%s " fmt, \
- blkg_path(&(cfqg)->blkg), ##args); \
+ blkg_path(&(cfqg)->blkg), ##args) \
#else
#define cfq_log_cfqq(cfqd, cfqq, fmt, args...) \
blk_add_trace_msg((cfqd)->queue, "cfq%d " fmt, (cfqq)->pid, ##args)
-#define cfq_log_cfqg(cfqd, cfqg, fmt, args...) do {} while (0);
+#define cfq_log_cfqg(cfqd, cfqg, fmt, args...) do {} while (0)
#endif
#define cfq_log(cfqd, fmt, args...) \
blk_add_trace_msg((cfqd)->queue, "cfq " fmt, ##args)
@@ -2768,11 +2768,14 @@ static void __cfq_exit_single_io_context(struct cfq_data *cfqd,
smp_wmb();
cic->key = cfqd_dead_key(cfqd);
+ rcu_read_lock();
if (rcu_dereference(ioc->ioc_data) == cic) {
+ rcu_read_unlock();
spin_lock(&ioc->lock);
rcu_assign_pointer(ioc->ioc_data, NULL);
spin_unlock(&ioc->lock);
- }
+ } else
+ rcu_read_unlock();
if (cic->cfqq[BLK_RW_ASYNC]) {
cfq_exit_cfqq(cfqd, cic->cfqq[BLK_RW_ASYNC]);
@@ -3079,7 +3082,8 @@ cfq_drop_dead_cic(struct cfq_data *cfqd, struct io_context *ioc,
spin_lock_irqsave(&ioc->lock, flags);
- BUG_ON(ioc->ioc_data == cic);
+ BUG_ON(rcu_dereference_check(ioc->ioc_data,
+ lockdep_is_held(&ioc->lock)) == cic);
radix_tree_delete(&ioc->radix_root, cfqd->cic_index);
hlist_del_rcu(&cic->cic_list);
@@ -3785,9 +3789,6 @@ new_queue:
return 0;
queue_fail:
- if (cic)
- put_io_context(cic->ioc);
-
cfq_schedule_dispatch(cfqd);
spin_unlock_irqrestore(q->queue_lock, flags);
cfq_log(cfqd, "set_request fail");
diff --git a/block/genhd.c b/block/genhd.c
index ed3fe8224f9f..82d97c3594a8 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -1371,6 +1371,7 @@ struct disk_events {
struct gendisk *disk; /* the associated disk */
spinlock_t lock;
+ struct mutex block_mutex; /* protects blocking */
int block; /* event blocking depth */
unsigned int pending; /* events already sent out */
unsigned int clearing; /* events being cleared */
@@ -1414,22 +1415,44 @@ static unsigned long disk_events_poll_jiffies(struct gendisk *disk)
return msecs_to_jiffies(intv_msecs);
}
-static void __disk_block_events(struct gendisk *disk, bool sync)
+/**
+ * disk_block_events - block and flush disk event checking
+ * @disk: disk to block events for
+ *
+ * On return from this function, it is guaranteed that event checking
+ * isn't in progress and won't happen until unblocked by
+ * disk_unblock_events(). Events blocking is counted and the actual
+ * unblocking happens after the matching number of unblocks are done.
+ *
+ * Note that this intentionally does not block event checking from
+ * disk_clear_events().
+ *
+ * CONTEXT:
+ * Might sleep.
+ */
+void disk_block_events(struct gendisk *disk)
{
struct disk_events *ev = disk->ev;
unsigned long flags;
bool cancel;
+ if (!ev)
+ return;
+
+ /*
+ * Outer mutex ensures that the first blocker completes canceling
+ * the event work before further blockers are allowed to finish.
+ */
+ mutex_lock(&ev->block_mutex);
+
spin_lock_irqsave(&ev->lock, flags);
cancel = !ev->block++;
spin_unlock_irqrestore(&ev->lock, flags);
- if (cancel) {
- if (sync)
- cancel_delayed_work_sync(&disk->ev->dwork);
- else
- cancel_delayed_work(&disk->ev->dwork);
- }
+ if (cancel)
+ cancel_delayed_work_sync(&disk->ev->dwork);
+
+ mutex_unlock(&ev->block_mutex);
}
static void __disk_unblock_events(struct gendisk *disk, bool check_now)
@@ -1461,27 +1484,6 @@ out_unlock:
}
/**
- * disk_block_events - block and flush disk event checking
- * @disk: disk to block events for
- *
- * On return from this function, it is guaranteed that event checking
- * isn't in progress and won't happen until unblocked by
- * disk_unblock_events(). Events blocking is counted and the actual
- * unblocking happens after the matching number of unblocks are done.
- *
- * Note that this intentionally does not block event checking from
- * disk_clear_events().
- *
- * CONTEXT:
- * Might sleep.
- */
-void disk_block_events(struct gendisk *disk)
-{
- if (disk->ev)
- __disk_block_events(disk, true);
-}
-
-/**
* disk_unblock_events - unblock disk event checking
* @disk: disk to unblock events for
*
@@ -1508,10 +1510,18 @@ void disk_unblock_events(struct gendisk *disk)
*/
void disk_check_events(struct gendisk *disk)
{
- if (disk->ev) {
- __disk_block_events(disk, false);
- __disk_unblock_events(disk, true);
+ struct disk_events *ev = disk->ev;
+ unsigned long flags;
+
+ if (!ev)
+ return;
+
+ spin_lock_irqsave(&ev->lock, flags);
+ if (!ev->block) {
+ cancel_delayed_work(&ev->dwork);
+ queue_delayed_work(system_nrt_wq, &ev->dwork, 0);
}
+ spin_unlock_irqrestore(&ev->lock, flags);
}
EXPORT_SYMBOL_GPL(disk_check_events);
@@ -1546,7 +1556,7 @@ unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask)
spin_unlock_irq(&ev->lock);
/* uncondtionally schedule event check and wait for it to finish */
- __disk_block_events(disk, true);
+ disk_block_events(disk);
queue_delayed_work(system_nrt_wq, &ev->dwork, 0);
flush_delayed_work(&ev->dwork);
__disk_unblock_events(disk, false);
@@ -1664,7 +1674,7 @@ static ssize_t disk_events_poll_msecs_store(struct device *dev,
if (intv < 0 && intv != -1)
return -EINVAL;
- __disk_block_events(disk, true);
+ disk_block_events(disk);
disk->ev->poll_msecs = intv;
__disk_unblock_events(disk, true);
@@ -1750,6 +1760,7 @@ static void disk_add_events(struct gendisk *disk)
INIT_LIST_HEAD(&ev->node);
ev->disk = disk;
spin_lock_init(&ev->lock);
+ mutex_init(&ev->block_mutex);
ev->block = 1;
ev->poll_msecs = -1;
INIT_DELAYED_WORK(&ev->dwork, disk_events_workfn);
@@ -1770,7 +1781,7 @@ static void disk_del_events(struct gendisk *disk)
if (!disk->ev)
return;
- __disk_block_events(disk, true);
+ disk_block_events(disk);
mutex_lock(&disk_events_mutex);
list_del_init(&disk->ev->node);