block: refactor put_io_context

Move the code to delay freeing the icqs into a separate helper.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20211209063131.18537-6-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/blk-ioc.c b/block/blk-ioc.c
index 04f3d2b0ca7db4636b42b58163de7f16e15b4129..ca996214c10a6db4cbe1c74f11a3421a6a6db65b 100644 (file)
--- 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);