diff options
| -rw-r--r-- | block/blk-ioc.c | 38 |
1 files changed, 19 insertions, 19 deletions
diff --git a/block/blk-ioc.c b/block/blk-ioc.c index 04f3d2b0ca7d..ca996214c10a 100644 --- a/block/blk-ioc.c +++ b/block/blk-ioc.c @@ -143,6 +143,24 @@ static void ioc_release_fn(struct work_struct *work) kmem_cache_free(iocontext_cachep, ioc); } +/* + * Releasing icqs requires reverse order double locking and we may already be + * holding a queue_lock. Do it asynchronously from a workqueue. + */ +static bool ioc_delay_free(struct io_context *ioc) +{ + unsigned long flags; + + spin_lock_irqsave(&ioc->lock, flags); + if (!hlist_empty(&ioc->icq_list)) { + queue_work(system_power_efficient_wq, &ioc->release_work); + spin_unlock_irqrestore(&ioc->lock, flags); + return true; + } + spin_unlock_irqrestore(&ioc->lock, flags); + return false; +} + /** * put_io_context - put a reference of io_context * @ioc: io_context to put @@ -152,26 +170,8 @@ static void ioc_release_fn(struct work_struct *work) */ void put_io_context(struct io_context *ioc) { - unsigned long flags; - bool free_ioc = false; - BUG_ON(atomic_long_read(&ioc->refcount) <= 0); - - /* - * Releasing ioc requires reverse order double locking and we may - * already be holding a queue_lock. Do it asynchronously from wq. - */ - if (atomic_long_dec_and_test(&ioc->refcount)) { - spin_lock_irqsave(&ioc->lock, flags); - if (!hlist_empty(&ioc->icq_list)) - queue_work(system_power_efficient_wq, - &ioc->release_work); - else - free_ioc = true; - spin_unlock_irqrestore(&ioc->lock, flags); - } - - if (free_ioc) + if (atomic_long_dec_and_test(&ioc->refcount) && !ioc_delay_free(ioc)) kmem_cache_free(iocontext_cachep, ioc); } EXPORT_SYMBOL_GPL(put_io_context); |