Re: [Qemu-trivial] [Qemu-devel] [PATCH] vl.c: move pidfile creation up

[Markus Armbruster]

Michael Tokarev <address@hidden> writes:

> With current code, pid file is open after various
> sockets, chardevs, fsdevs and the like.  This causes
> interesting effects, for example when monitor is a
> unix-socket, and another qemu instance is already
> running, new qemu first "damages" the socket and
> next complain that it can't acquire the pid file and
> exits, making running qemu unreachable.
>
> Move pid file creation a bit earlier.

Makes sense, but ...

> Signed-off-by: Michael Tokarev <address@hidden>
> ---
>  vl.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/vl.c b/vl.c
> index 55763f7..7989f75 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -4305,6 +4305,11 @@ int main(int argc, char **argv, char **envp)
>          exit(1);
>      }
>  
> +    if (pid_file && qemu_create_pidfile(pid_file) != 0) {
> +        error_report("could not acquire pid file: %s", strerror(errno));
> +        exit(1);
> +    }
> +
>      page_size_init();
>      socket_init();
>  

... is this early enough?  For instance, we clobber the log file another
200 lines further up.

A "don't clobber anything externally visible before this spot" comment
could be useful.

> @@ -4326,11 +4331,6 @@ int main(int argc, char **argv, char **envp)
>      }
>  #endif
>  
> -    if (pid_file && qemu_create_pidfile(pid_file) != 0) {
> -        error_report("could not acquire pid file: %s", strerror(errno));
> -        exit(1);
> -    }
> -
>      if (qemu_opts_foreach(qemu_find_opts("device"),
>                            device_help_func, NULL, NULL)) {
>          exit(0);