block: factor out a bd_end_claim helper from blkdev_put

Move all the logic to release an exclusive claim into a helper.

Signed-off-by: Christoph Hellwig <hch@lst.de>

diff --git a/block/bdev.c b/block/bdev.c
index 850852fe4b78e15b2bb603c7f7c447fc6ab57941..f2c7181b0bba7d056c89ddbe184973ed74aa9590 100644 (file)
--- a/block/bdev.c
+++ b/block/bdev.c
@@ -578,6 +578,37 @@ void bd_abort_claiming(struct block_device *bdev, void *holder)
 }
 EXPORT_SYMBOL(bd_abort_claiming);
 
+static void bd_end_claim(struct block_device *bdev)
+{
+       struct block_device *whole = bdev_whole(bdev);
+       bool unblock = false;
+
+       /*
+        * Release a claim on the device.  The holder fields are protected with
+        * bdev_lock.  open_mutex is used to synchronize disk_holder unlinking.
+        */
+       spin_lock(&bdev_lock);
+       WARN_ON_ONCE(--bdev->bd_holders < 0);
+       WARN_ON_ONCE(--whole->bd_holders < 0);
+       if (!bdev->bd_holders) {
+               bdev->bd_holder = NULL;
+               if (bdev->bd_write_holder)
+                       unblock = true;
+       }
+       if (!whole->bd_holders)
+               whole->bd_holder = NULL;
+       spin_unlock(&bdev_lock);
+
+       /*
+        * If this was the last claim, remove holder link and unblock evpoll if
+        * it was a write holder.
+        */
+       if (unblock) {
+               disk_unblock_events(bdev->bd_disk);
+               bdev->bd_write_holder = false;
+       }
+}
+
 static void blkdev_flush_mapping(struct block_device *bdev)
 {
        WARN_ON_ONCE(bdev->bd_holders);
@@ -832,36 +863,8 @@ void blkdev_put(struct block_device *bdev, fmode_t mode)
                sync_blockdev(bdev);
 
        mutex_lock(&disk->open_mutex);
-       if (mode & FMODE_EXCL) {
-               struct block_device *whole = bdev_whole(bdev);
-               bool bdev_free;
-
-               /*
-                * Release a claim on the device.  The holder fields
-                * are protected with bdev_lock.  open_mutex is to
-                * synchronize disk_holder unlinking.
-                */
-               spin_lock(&bdev_lock);
-
-               WARN_ON_ONCE(--bdev->bd_holders < 0);
-               WARN_ON_ONCE(--whole->bd_holders < 0);
-
-               if ((bdev_free = !bdev->bd_holders))
-                       bdev->bd_holder = NULL;
-               if (!whole->bd_holders)
-                       whole->bd_holder = NULL;
-
-               spin_unlock(&bdev_lock);
-
-               /*
-                * If this was the last claim, remove holder link and
-                * unblock evpoll if it was a write holder.
-                */
-               if (bdev_free && bdev->bd_write_holder) {
-                       disk_unblock_events(disk);
-                       bdev->bd_write_holder = false;
-               }
-       }
+       if (mode & FMODE_EXCL)
+               bd_end_claim(bdev);
 
        /*
         * Trigger event checking and tell drivers to flush MEDIA_CHANGE