On Fri, Mar 12, 2021 at 06:44:55PM +0300, Sergei Shtepa wrote: > DM_INTERPOSED_FLAG allow to create DM targets on "the fly". > Underlying block device opens without a flag FMODE_EXCL. > DM target receives bio from the original device via > bdev_interposer. This is more of a philopical comment, but the idea of just letting the interposed reopen the device by itself seems like a bad idea. I think that is probably better hidden in the block layer interposer attachment function, which could do the extra blkdev_get_by_dev for the caller.