[systemd-devel] Fwd: Handling ExecStop failure

[Lennart Poettering]

On Mon, 23.05.16 18:16, Ashish Sangwan (ashishsangwan2 at gmail.com) wrote:

> On Mon, May 23, 2016 at 2:13 PM, Lennart Poettering
> <lennart at poettering.net> wrote:
> > On Mon, 23.05.16 13:30, Ashish Sangwan (ashishsangwan2 at gmail.com) wrote:
> >
> >> The first issue is, once the command mentioned in ExecStop failed due
> >> to mountpoint busy, the user comes out of the mountpoint, making it
> >> un-busy and again fires the systemctl stop command, however the status
> >> of the service is not changed, it remained in failed state and the
> >> mountpoint remains mounted.
> >
> > Service stop executables failing just indicate to systemd that the
> > service failed. If this happens, systemd will kill all remaining
> > processes of the service and then put the service in "failed" state.
> >
> > I think the source of the confusion here is really that you are using
> > a .service unit to model a mount point, where you really should be
> > using a .mount unit. For regular mounts systemd will actually notice
> > that the mount point continues to exist according to
> > /proc/self/mountinfo after the stop command failed, and thus not
> > actually consider the unit down if the ExecStop= command failed.
> 
> I am not sure but if I use .mount unit than I won't get to execute the file
> system binary because ExecStart/Stop is not available in .mount?

Yeah, the assumption is that for fuse-based file systems the
mount.<fs> logic implemented in the /usr/bin/mount utility is used:
i.e. it already supports invoking external helpers for specific file
systems anyway.

> > Maybe your program code detects whether it is connected to a TTY or
> > not, and behaves differently, for example logs directly via syslog()
> > when it is not connected to a tty? (note that if you use
> > StandardOutput=console+journal you are only indirectly connected to
> > the console, through a socket to journald). Do you see the logs it
> > generates in the journal at least?
> 
> Yes, it generates the log in journal. To make sure it is not my program which
> is the culprit I made a really *simple* script which just echo a
> single line and invoke it
> using systemctl start/stop. Still the output is not getting printed on
> the console.
> Could you suggest some debugging steps which I can try to root cause the issue?

As discussed in the other mails in this thread: maybe this is simply
confusion about what "console" in StandardOutput=console+journal
actually means. It does not mean the tty that you invoked "systemctl"
from. Instead, it literally means /dev/console, i.e. the kernel's
console device, wherever that may point to. if you are running a
graphical UI of some kinda, /dev/console is usually not seen.

Lennart

-- 
Lennart Poettering, Red Hat