How do I get bcache to completely give up access to a backing device so I can mount it using losetup? My backing device is an lvm logical volume which I expanded in size. I want to mount it using losetup to use xfs_growfs however I can't access the backing device: root@timber4:/var/log# umount /mnt/archives/ ; echo 1 > /sys/block/bcache1/bcache/stop ; echo 1 > /sys/block/dm-1/bcache/stop ; losetup -o 8192 /dev/loop0 /dev/vg-bfd02/archives_bc -bash: /sys/block/dm-1/bcache/stop: No such file or directory losetup: /dev/vg-bfd02/archives_bc: failed to set up loop device: Device or resource busy I know in some cases udev is scurrying in and causing the cache to be recreated but even immediately after the stop and before udev can get in the backing device is still locked: Jan 22 11:48:33 timber4 kernel: [370093.820204] XFS (bcache1): Unmounting Filesystem Jan 22 11:48:33 timber4 kernel: [370093.830609] bcache: bcache_device_free() bcache1 stopped Jan 22 11:48:33 timber4 systemd[1]: Stopped File System Check on /dev/disk/by-uuid/cb9c1149-73b8-4929-bcc6-d1599d41da73. Jan 22 11:48:33 timber4 kernel: [370093.904348] bcache: register_bcache() error /dev/dm-1: device busy I was able to do this in the past when I first started learning to use bcache which is why this is especially perplexing. Suggestions? Thanks, Brendan
