Status from old attempts to solve same nature issues: ----
Older (2018) merge request from @raharper: https://github.com/koverstreet/bcache-tools/pull/1 addressing the fact that kernel uevents would not always emit CACHED_UUID parameters, making udev to delete (whenever that happens) /dev/bcache/{by-uuid,by-label} symlinks. This last MR pointed to previous related bugs: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=890446 https://bugs.launchpad.net/curtin/+bug/1728742 And to an upstream kernel patch: https://lore.kernel.org/patchwork/patch/921298/ to https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1729145 that wasn't accepted upstream. Even not being accepted upstream, the SRU was attempted: LP: #1729145 https://lists.ubuntu.com/archives/kernel-team/2017-December/088680.html https://lists.ubuntu.com/archives/kernel-team/2017-December/088679.html Both were NACKED. Attempted again: https://lists.ubuntu.com/archives/kernel-team/2017-December/088682.html https://lists.ubuntu.com/archives/kernel-team/2017-December/088683.html NACKED again. And a v2 was sent: https://lists.ubuntu.com/archives/kernel-team/2017-December/088751.html https://lists.ubuntu.com/archives/kernel-team/2017-December/088750.html https://lists.ubuntu.com/archives/kernel-team/2017-December/088749.html and acked in January 2018 by Coling: https://lists.ubuntu.com/archives/kernel-team/2018-January/089492.html but not upstreamed. BIONIC contains the fix: commit ed9333e1b583 Author: Ryan Harper <ryan.har...@canonical.com> Date: Mon Dec 11 12:12:01 2017 UBUNTU: SAUCE: (no-up) bcache: decouple emitting a cached_dev CHANGE uevent BugLink: http://bugs.launchpad.net/bugs/1729145 - decouple emitting a cached_dev CHANGE uevent which includes dev.uuid and dev.label from bch_cached_dev_run() which only happens when a bcacheX device is bound to the actual backing block device (bcache0 -> vdb) - update bch_cached_dev_run() to invoke bch_cached_dev_emit_change() as needed; no functional code path changes here - Modify register_bcache to detect a re-registering of a bcache cached_dev, and in that case call bcache_cached_dev_emit_change() to Signed-off-by: Ryan Harper <ryan.har...@canonical.com> Signed-off-by: Joseph Salisbury <joseph.salisb...@canonical.com> Acked-by: Colin Ian King <colin.k...@canonical.com> Acked-by: Stefan Bader <stefan.ba...@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmou...@canonical.com> [ saf: fix incorrect indentation ] Signed-off-by: Seth Forshee <seth.fors...@canonical.com> FOCAL contains the fix: commit 67553dcd7905 Author: Ryan Harper <ryan.har...@canonical.com> Date: Mon Dec 11 12:12:01 2017 UBUNTU: SAUCE: (no-up) bcache: decouple emitting a cached_dev CHANGE uevent GROOVY contains the fix: commit 67553dcd7905 Author: Ryan Harper <ryan.har...@canonical.com> Date: Mon Dec 11 12:12:01 2017 UBUNTU: SAUCE: (no-up) bcache: decouple emitting a cached_dev CHANGE uevent ---- So, the kernel patch wasn't accepted, nor bcache-tools patch by @raharper, the bcache-export-cached. ---- New Upstream summary from @raharper: https://github.com/systemd/systemd/pull/16317#issuecomment-655647313 in the upstream merge request made by @rbalint. ** Bug watch added: Debian Bug tracker #890446 https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=890446 -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to systemd in Ubuntu. https://bugs.launchpad.net/bugs/1861941 Title: bcache by-uuid links disappear after mounting bcache0 Status in bcache-tools package in Ubuntu: Fix Released Status in systemd package in Ubuntu: Fix Released Status in bcache-tools source package in Bionic: Triaged Status in systemd source package in Bionic: Triaged Status in bcache-tools source package in Focal: Confirmed Status in systemd source package in Focal: Triaged Bug description: 1. root@ubuntu:~# lsb_release -rd Description: Ubuntu Focal Fossa (development branch) Release: 20.04 2. root@ubuntu:~# lsb_release -rd Description: Ubuntu Focal Fossa (development branch) Release: 20.04 root@ubuntu:~# apt-cache policy linux-image-virtual linux-image-virtual: Installed: 5.4.0.12.15 Candidate: 5.4.0.12.15 Version table: *** 5.4.0.12.15 500 500 http://archive.ubuntu.com/ubuntu focal/main amd64 Packages 100 /var/lib/dpkg/status root@ubuntu:~# apt-cache policy linux-image-5.4.0-12-generic linux-image-5.4.0-12-generic: Installed: 5.4.0-12.15 Candidate: 5.4.0-12.15 Version table: *** 5.4.0-12.15 500 500 http://archive.ubuntu.com/ubuntu focal/main amd64 Packages 100 /var/lib/dpkg/status 3. mount /dev/bcache0 && ls -al /dev/bcache/by-uuid/ + ls -al /dev/bcache/by-uuid/ total 0 drwxr-xr-x 2 root root 60 Feb 4 23:31 . drwxr-xr-x 3 root root 60 Feb 4 23:31 .. lrwxrwxrwx 1 root root 13 Feb 4 23:31 abdfd1f6-44ce-4266-91db-24667b9ae51a -> ../../bcache0 4. root@ubuntu:~# ls -al /dev/bcache/by-uuid ls: cannot access '/dev/bcache/by-uuid': No such file or directory ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: linux-image-5.4.0-12-generic 5.4.0-12.15 ProcVersionSignature: Ubuntu 5.4.0-12.15-generic 5.4.8 Uname: Linux 5.4.0-12-generic x86_64 ApportVersion: 2.20.11-0ubuntu16 Architecture: amd64 Date: Tue Feb 4 23:31:52 2020 ProcEnviron: TERM=xterm-256color PATH=(custom, no user) LANG=C.UTF-8 SHELL=/bin/bash SourcePackage: linux-signed-5.4 UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/bcache-tools/+bug/1861941/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp