On Fri, Mar 08, 2024 at 09:34:03PM +0530, Anand Jain wrote: > > bdev_open_by_path. bdev_open_by_path bdev_open_by_path calls > > lookup_bdev to translate the path to a dev_t and then calls > > bdev_open_by_dev on the dev_t, which stored the passes in dev_t in > > bdev->bd_dev. I see absolutely no way how this check could ever > > trigger. > > > > Prior to this patch, the device->devt value of the device could become > stale, as it might not have been updated since the last scan of the > device. During this interval, the device could have undergone changes > to its devt. How can it become stale here? btrfs_open_one_device exits early if device->bdev is set, so you set up a new device->bdev and stash the just opened bdev there. The dev_t of an existing struct block_device never changes, so it must match the one in the btrfs_device that was just initialized from it.
