[PATCH 3/9] block: factor out a bd_end_claim helper from blkdev_put

Christoph Hellwig
2023-05-05T17:53:06Z

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

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
block/bdev.c | 63 +++++++++++++++++++++++++++-------------------------
1 file changed, 33 insertions(+), 30 deletions(-)

diff --git a/block/bdev.c b/block/bdev.c
index 850852fe4b78e1..f2c7181b0bba7d 100644
--- 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
--
2.39.2