Tested with 1.1ubuntu1.18.04.6:
root@uu-frontend-lock:~# strace unattended-upgrade --verbose --dry-run 2>&1 |
grep lock
openat(AT_FDCWD, "/var/run/unattended-upgrades.lock",
O_RDWR|O_CREAT|O_NOFOLLOW, 0640) = 4
openat(AT_FDCWD, "/var/lib/dpkg/lock-frontend", O_RDWR|O_CREAT|O_NOFOLLOW,
0640) = 5
openat(AT_FDCWD, "/var/lib/dpkg/lock", O_RDWR|O_CREAT|O_NOFOLLOW, 0640) = 6
openat(AT_FDCWD, "/var/lib/dpkg/lock-frontend", O_RDWR|O_CREAT|O_NOFOLLOW,
0640) = 5
openat(AT_FDCWD, "/var/lib/dpkg/lock", O_RDWR|O_CREAT|O_NOFOLLOW, 0640) = 6
openat(AT_FDCWD, "/var/cache/apt/archives/lock", O_RDWR|O_CREAT|O_NOFOLLOW,
0640) = 37
openat(AT_FDCWD, "/var/lib/dpkg/lock", O_RDWR|O_CREAT|O_NOFOLLOW, 0640) = 6
openat(AT_FDCWD, "/var/lib/dpkg/lock-frontend", O_RDWR|O_CREAT|O_NOFOLLOW,
0640) = 5
openat(AT_FDCWD, "/var/lib/dpkg/lock", O_RDWR|O_CREAT|O_NOFOLLOW, 0640) = 6
root@uu-frontend-lock:~# apt-get install una
unaccent unace-nonfree unagi unagi-dev
unar
unace unadf unagi-dbg unalz
unattended-upgrades
root@uu-frontend-lock:~# apt-get install unattended-upgrades
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following package was automatically installed and is no longer required:
libfreetype6
Use 'apt autoremove' to remove it.
Suggested packages:
bsd-mailx default-mta | mail-transport-agent needrestart
The following packages will be upgraded:
unattended-upgrades
1 upgraded, 0 newly installed, 0 to remove and 23 not upgraded.
Need to get 37.7 kB of archives.
After this operation, 0 B of additional disk space will be used.
Get:1 http://archive.ubuntu.com/ubuntu bionic-proposed/main amd64
unattended-upgrades all 1.1ubuntu1.18.04.6 [37.7 kB]
Fetched 37.7 kB in 0s (186 kB/s)
Preconfiguring packages ...
(Reading database ... 28996 files and directories currently installed.)
Preparing to unpack .../unattended-upgrades_1.1ubuntu1.18.04.6_all.deb ...
Unpacking unattended-upgrades (1.1ubuntu1.18.04.6) over (1.1ubuntu1.18.04.5) ...
Processing triggers for ureadahead (0.100.0-20) ...
Processing triggers for systemd (237-3ubuntu10.3) ...
Setting up unattended-upgrades (1.1ubuntu1.18.04.6) ...
Processing triggers for man-db (2.8.3-2) ...
root@uu-frontend-lock:~# strace unattended-upgrade --verbose --dry-run 2>&1 |
grep lock
openat(AT_FDCWD, "/var/run/unattended-upgrades.lock",
O_RDWR|O_CREAT|O_NOFOLLOW, 0640) = 4
openat(AT_FDCWD, "/var/lib/dpkg/lock-frontend", O_RDWR|O_CREAT|O_NOFOLLOW,
0640) = 5
openat(AT_FDCWD, "/var/lib/dpkg/lock", O_RDWR|O_CREAT|O_NOFOLLOW, 0640) = 6
openat(AT_FDCWD, "/var/cache/apt/archives/lock", O_RDWR|O_CREAT|O_NOFOLLOW,
0640) = 37
openat(AT_FDCWD, "/var/lib/dpkg/lock", O_RDWR|O_CREAT|O_NOFOLLOW, 0640) = 6
root@uu-frontend-lock:~#
** Tags removed: verification-needed verification-needed-bionic
** Tags added: verification-done verification-done-bionic
--
You received this bug notification because you are a member of Ubuntu
Touch seeded packages, which is subscribed to unattended-upgrades in
Ubuntu.
https://bugs.launchpad.net/bugs/1789637
Title:
Proper support for frontend lock
Status in unattended-upgrades package in Ubuntu:
Fix Released
Status in unattended-upgrades source package in Xenial:
Confirmed
Status in unattended-upgrades source package in Bionic:
Fix Committed
Bug description:
[Impact]
Apt and dpkg implemented the Frontend Locking API and unattended-
upgrades needs to adopt it to not leave the packaging system unlocked
while passing control to python-apt and dpkg to perform package
installations and removals. Leaving the packaging system unlocked
caused many crashes of u-u when other tools took the lock and in the
worse case let other package management tools operate on dpkg's
database breaking systems.
The change takes advantage of python-apt's new API and keeps the
frontend lock during the run of u-u and unlocks only the inner locks
for committing changes.
[Test case]
Run strace unattended-upgrades to upgrade several packages and check
that lock-frontend is acquired at the beginning and not released until
the end (not reacquired repeatedly).
Unfixed u-u's output is like this:
# strace unattended-upgrade --verbose --dry-run 2>&1 | grep lock
openat(AT_FDCWD, "/var/run/unattended-upgrades.lock",
O_RDWR|O_CREAT|O_NOFOLLOW, 0640) = 4
openat(AT_FDCWD, "/var/lib/dpkg/lock-frontend", O_RDWR|O_CREAT|O_NOFOLLOW,
0640) = 5
openat(AT_FDCWD, "/var/lib/dpkg/lock", O_RDWR|O_CREAT|O_NOFOLLOW, 0640) = 6
openat(AT_FDCWD, "/var/lib/dpkg/lock-frontend", O_RDWR|O_CREAT|O_NOFOLLOW,
0640) = 5
openat(AT_FDCWD, "/var/lib/dpkg/lock", O_RDWR|O_CREAT|O_NOFOLLOW, 0640) = 6
openat(AT_FDCWD, "/var/cache/apt/archives/lock", O_RDWR|O_CREAT|O_NOFOLLOW,
0640) = 93
openat(AT_FDCWD, "/var/lib/dpkg/lock", O_RDWR|O_CREAT|O_NOFOLLOW, 0640) = 6
openat(AT_FDCWD, "/var/lib/dpkg/lock-frontend", O_RDWR|O_CREAT|O_NOFOLLOW,
0640) = 5
openat(AT_FDCWD, "/var/lib/dpkg/lock", O_RDWR|O_CREAT|O_NOFOLLOW, 0640) = 6
openat(AT_FDCWD, "/var/lib/dpkg/lock-frontend", O_RDWR|O_CREAT|O_NOFOLLOW,
0640) = 5
openat(AT_FDCWD, "/var/lib/dpkg/lock", O_RDWR|O_CREAT|O_NOFOLLOW, 0640) = 6
...
Fixed u-u's output is like that:
# strace unattended-upgrade --dry-run --verbose 2>&1 | grep lock
openat(AT_FDCWD, "/var/run/unattended-upgrades.lock",
O_RDWR|O_CREAT|O_NOFOLLOW, 0640) = 4
openat(AT_FDCWD, "/var/lib/dpkg/lock-frontend", O_RDWR|O_CREAT|O_NOFOLLOW,
0640) = 8
openat(AT_FDCWD, "/var/lib/dpkg/lock", O_RDWR|O_CREAT|O_NOFOLLOW, 0640) = 10
openat(AT_FDCWD, "/var/cache/apt/archives/lock", O_RDWR|O_CREAT|O_NOFOLLOW,
0640) = 57
openat(AT_FDCWD, "/var/lib/dpkg/lock", O_RDWR|O_CREAT|O_NOFOLLOW, 0640) = 10
openat(AT_FDCWD, "/var/cache/apt/archives/lock", O_RDWR|O_CREAT|O_NOFOLLOW,
0640) = 69
openat(AT_FDCWD, "/var/lib/dpkg/lock", O_RDWR|O_CREAT|O_NOFOLLOW, 0640) = 10
openat(AT_FDCWD, "/var/cache/apt/archives/lock", O_RDWR|O_CREAT|O_NOFOLLOW,
0640) = 70
openat(AT_FDCWD, "/var/lib/dpkg/lock", O_RDWR|O_CREAT|O_NOFOLLOW, 0640) = 10
...
[Regression potential]
Incorrect lock API usage can make unattended-upgrades to crash, but it
is unlikely to hang since the lock handling operations are non-
blocking. Failing to reserve the locks can also cause problems by
allowing other package management tools to install packages in
parallel, but this problem existed in the past, too.
[Additional Info]
This is part of a wider series of changes for frontend locking
- dpkg (bug 1796081)
- apt (bug 1781169)
- python-apt (bug 1795407)
- packagekit (bug 1795614)
- unattended-upgrades (bug 1789637)
- aptdaemon (no bug filed yet)
Further details about frontend locking can be found in
https://lists.debian.org/debian-dpkg/2017/01/msg00044.html
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/unattended-upgrades/+bug/1789637/+subscriptions
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