[systemd-devel] Unable to override systemd-udevd.service

[Andrey Borzenkov]

В Wed, 23 Apr 2014 06:43:04 +0200
Lennart Poettering <lennart at poettering.net> пишет:

> On Sun, 30.03.14 19:23, Andrey Borzenkov (arvidjaar at gmail.com) wrote:
> 
> > linux-qbc6:~ # systemctl show systemd-udevd.service -p FragmentPath
> > FragmentPath=/usr/lib/systemd/system/systemd-udevd.service
> > linux-qbc6:~ # cp /usr/lib/systemd/system/systemd-udevd.service /etc/systemd/system
> > linux-qbc6:~ # systemctl daemon-reload 
> > linux-qbc6:~ # cp /usr/lib/systemd/system/systemd-udevd.service /etc/systemd/system
> > linux-qbc6:~ # systemctl show systemd-udevd.service -p FragmentPath
> > FragmentPath=/usr/lib/systemd/system/systemd-udevd.service
> > linux-qbc6:~ # exit
> > 
> > >From non-exhaustive testing it appears to be the only unit showing this
> > property. Enabling systemd debug does not add any useful information
> > (no output about unit discovery). Any way to debug it?
> > 
> > The version is systemd-208-19.1.x86_64 from openSUSE.
> 
> Hmm, that's weird. Is /etc on some weird mount point or so?
> 

Not really. Just plain disk in QEMU VM.

17 21 0:5 / /dev rw,relatime shared:2 - devtmpfs devtmpfs rw,size=380164k,nr_inodes=95041,mode=755
18 17 0:15 / /dev/shm rw,relatime shared:3 - tmpfs tmpfs rw
19 21 0:16 / /run rw,nosuid,nodev,relatime shared:6 - tmpfs tmpfs rw,mode=755
20 17 0:11 / /dev/pts rw,relatime shared:4 - devpts devpts rw,gid=5,mode=620,ptmxmode=000
21 1 8:2 / / rw,relatime shared:1 - ext4 /dev/sda2 rw,data=ordered
... etc

> It might be interesting to run "strace -o log -e open -p 1" and then trigger a
> reload, and then look at the generate log file "log". It should show you
> where systemd is looking for the udev service file, and might contain a
> hint, why it skips the file in /etc?
> 

Actually, it does not :)

1     open("/usr/lib/systemd/system/systemd-udevd.service", O_RDONLY|O_NOCTTY|O_LARGEFILE|O_NOFOLLOW|O_CLOEXEC) = 17
1     open("/usr/lib/systemd/system/systemd-udevd-kernel.socket", O_RDONLY|O_NOCTTY|O_LARGEFILE|O_NOFOLLOW|O_CLOEXEC) = 17
1     open("/usr/lib/systemd/system/systemd-udevd-control.socket", O_RDONLY|O_NOCTTY|O_LARGEFILE|O_NOFOLLOW|O_CLOEXEC) = 17
1     open("/etc/systemd/system/systemd-udevd.service", O_RDONLY|O_NOCTTY|O_LARGEFILE|O_CLOEXEC) = 18
1     openat(AT_FDCWD, "/etc/systemd/system/systemd-udevd.service.d", O_RDONLY|O_NONBLOCK|O_LARGEFILE|O_DIRECTORY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
1     openat(AT_FDCWD, "/run/systemd/system/systemd-udevd.service.d", O_RDONLY|O_NONBLOCK|O_LARGEFILE|O_DIRECTORY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
1     openat(AT_FDCWD, "/run/systemd/generator/systemd-udevd.service.d", O_RDONLY|O_NONBLOCK|O_LARGEFILE|O_DIRECTORY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
1     openat(AT_FDCWD, "/usr/local/lib/systemd/system/systemd-udevd.service.d", O_RDONLY|O_NONBLOCK|O_LARGEFILE|O_DIRECTORY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
1     openat(AT_FDCWD, "/usr/lib/systemd/system/systemd-udevd.service.d", O_RDONLY|O_NONBLOCK|O_LARGEFILE|O_DIRECTORY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
1     openat(AT_FDCWD, "/lib/systemd/system/systemd-udevd.service.d", O_RDONLY|O_NONBLOCK|O_LARGEFILE|O_DIRECTORY|O_CLOEXEC) = -1 ENOENT (No such file or directory)

But this is really the only system exhibiting this behavior ... another
VM with the same openSUSE version does not. This particular system
ignores /etc/systemd/system/systemd-udev.service even after reboot.