On 7/18/22 08:34, Christoph Hellwig wrote:
Now that devices are on the all_mddevs list until the gendisk is freed,
there can't be any duplicates. Remove the global list lookup and just
grab a reference.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
drivers/md/md.c | 42 +++++++++++++++---------------------------
1 file changed, 15 insertions(+), 27 deletions(-)
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 08cf21ad4c2d7..9b1e61b4bac8b 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -7785,45 +7785,33 @@ static int md_set_read_only(struct block_device *bdev, bool ro)
static int md_open(struct block_device *bdev, fmode_t mode)
{
- /*
- * Succeed if we can lock the mddev, which confirms that
- * it isn't being stopped right now.
- */
- struct mddev *mddev = mddev_find(bdev->bd_dev);
+ struct mddev *mddev;
int err;
+ spin_lock(&all_mddevs_lock);
+ mddev = mddev_get(bdev->bd_disk->private_data);
+ spin_unlock(&all_mddevs_lock);
if (!mddev)
return -ENODEV;
- if (mddev->gendisk != bdev->bd_disk) {
- /* we are racing with mddev_put which is discarding this
- * bd_disk.
- */
- mddev_put(mddev);
- /* Wait until bdev->bd_disk is definitely gone */
- if (work_pending(&mddev->del_work))
- flush_workqueue(md_misc_wq);
- return -EBUSY;
- }
- BUG_ON(mddev != bdev->bd_disk->private_data);
-
- if ((err = mutex_lock_interruptible(&mddev->open_mutex)))
+ err = mutex_lock_interruptible(&mddev->open_mutex);
+ if (err)
goto out;
- if (test_bit(MD_CLOSING, &mddev->flags)) {
- mutex_unlock(&mddev->open_mutex);
- err = -ENODEV;
- goto out;
- }
+ err = -ENODEV;
+ if (test_bit(MD_CLOSING, &mddev->flags))
+ goto out_unlock;
- err = 0;
atomic_inc(&mddev->openers);
mutex_unlock(&mddev->open_mutex);
bdev_check_media_change(bdev);
- out:
- if (err)
- mddev_put(mddev);
+ return 0;
+
+out_unlock:
+ mutex_unlock(&mddev->open_mutex);
+out:
+ mddev_put(mddev);
return err;
}
Reviewed-by: Hannes Reinecke <hare@xxxxxxx>
Cheers,
Hannes
