From 567818d8db287208522b8ac935d2dadc73d6d3da Mon Sep 17 00:00:00 2001 From: Richard Ipsum Date: Sat, 31 Oct 2015 16:56:59 +0000 Subject: Fix bug in fstab layout generation This fixes a bug in our fstab layout generation, currently we fail to generate the complete fstab layout, so /etc/fstab in any newly deployed or upgraded baserocks contains just: # Morph default system layout UUID= / btrfs defaults,rw,noatime 0 1 This is actually a pretty bad problem because it breaks system-version-manager, since systemd creates a btrfs subvolume and mounts it to /var/lib/machines if /var/lib/machines doesn't already exist[1]. As a result system-version-manager when asked to remove an image will fail to do so, since it will fail to remove the /run subvolume because of the subvolume created at /run/var/lib/machines. The result is a partially removed image that cannot be removed with system-version-manager. The fstab layout we use currently: UUID= / btrfs defaults,rw,noatime 0 1 UUID= /var btrfs subvol=/state/var,defaults,rw,noatime 0 2 UUID= /opt btrfs subvol=/state/opt,defaults,rw,noatime 0 2 UUID= /srv btrfs subvol=/state/srv,defaults,rw,noatime 0 2 UUID= /root btrfs subvol=/state/root,defaults,rw,noatime 0 2 UUID= /home btrfs subvol=/state/home,defaults,rw,noatime 0 2 ensures that anything created under /var goes into a shared /state/var subvolume, so when systemd creates its 'machines' subvolume it will be under state/ which doesn't cause any problems when we try to remove a system. To reproduce, deploy an upgrade to your machine, reboot into the upgraded system, when you cat /etc/fstab you should see only one entry, mounting /. Now switch back to the previous image with, system-version-manager set-default reboot remove the newly deployed image with, system-version-manager remove after some time this will fail with an error message similar to this: Removing system: faultylayout Delete subvolume (no-commit): '/tmp/tmp1gdIL2/systems/faultylayout/run' ERROR: cannot delete '/tmp/tmp1gdIL2/systems/faultylayout/run' - Directory not empty Delete subvolume (no-commit): '/tmp/tmp1gdIL2/systems/faultylayout/orig' Traceback (most recent call last): File "/usr/bin/system-version-manager", line 421, in SystemVersionManager(sys.argv, mount_dir).run() File "/usr/bin/system-version-manager", line 401, in run self.cmd_remove(args.system_name) File "/usr/bin/system-version-manager", line 363, in cmd_remove shutil.rmtree(system_root) File "/usr/lib/python2.7/shutil.py", line 247, in rmtree rmtree(fullname, ignore_errors, onerror) File "/usr/lib/python2.7/shutil.py", line 247, in rmtree rmtree(fullname, ignore_errors, onerror) File "/usr/lib/python2.7/shutil.py", line 247, in rmtree rmtree(fullname, ignore_errors, onerror) File "/usr/lib/python2.7/shutil.py", line 247, in rmtree rmtree(fullname, ignore_errors, onerror) File "/usr/lib/python2.7/shutil.py", line 256, in rmtree onerror(os.rmdir, path, sys.exc_info()) File "/usr/lib/python2.7/shutil.py", line 254, in rmtree os.rmdir(path) OSError: [Errno 1] Operation not permitted: '/tmp/tmp1gdIL2/systems/faultylayout/run/var/lib/machines [1]: http://cgit.freedesktop.org/systemd/systemd/commit/?id=113b3fc1a8061f4a24dd0db74e9a3cd0083b2251 Change-Id: I9c160d1fdd75fbbf9a3336d1ce35e4ce8ed7787d --- extensions/writeexts.py | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/extensions/writeexts.py b/extensions/writeexts.py index de7c0f2e..f356a34a 100644 --- a/extensions/writeexts.py +++ b/extensions/writeexts.py @@ -606,10 +606,10 @@ class WriteExtension(Extension): fstab.add_line('%s / btrfs defaults,rw,noatime 0 1' % root_device) # Add fstab entries for partitions + part_mountpoints = set() if device: mount_parts = set(p for p in device.partitionlist if hasattr(p, 'mountpoint') and p.mountpoint != '/') - part_mountpoints = set(p.mountpoint for p in mount_parts) for part in mount_parts: if part.mountpoint not in existing_mounts: # Get filesystem UUID @@ -621,17 +621,18 @@ class WriteExtension(Extension): fstab.add_line('UUID=%s %s %s defaults,rw,noatime ' '0 2' % (part_uuid, part.mountpoint, part.filesystem)) + part_mountpoints.add(part.mountpoint) else: self.status(msg='WARNING: an entry already exists in ' 'fstab for %s partition, skipping' % part.mountpoint) # Add entries for state dirs + all_mountpoints = set(existing_mounts.keys()) | part_mountpoints state_dirs_to_create = set() for state_dir in shared_state_dirs: mp = '/' + state_dir - if (mp not in existing_mounts and - (device and mp not in part_mountpoints)): + if mp not in all_mountpoints: state_dirs_to_create.add(state_dir) state_subvol = os.path.join('/state', state_dir) fstab.add_line( -- cgit v1.2.1