On 2/2/22 17:28, Vasiliy Ulyanov wrote: > The function will attempt to read a pid from @path, and store it in > @pid. The @pid will only be set, however, if @path is locked by > virFileLock() at byte 0 and the pid in @path is running. > > Signed-off-by: Vasiliy Ulyanov <vulyanov@xxxxxxx> > --- > src/libvirt_private.syms | 1 + > src/util/virpidfile.c | 34 ++++++++++++++++++++++++++++++++++ > src/util/virpidfile.h | 2 ++ > 3 files changed, 37 insertions(+) > > diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms > index 9bc3d9530b..447ba9d82b 100644 > --- a/src/libvirt_private.syms > +++ b/src/libvirt_private.syms > @@ -3070,6 +3070,7 @@ virPidFileRead; > virPidFileReadIfAlive; > virPidFileReadPath; > virPidFileReadPathIfAlive; > +virPidFileReadPathIfLocked; > virPidFileRelease; > virPidFileReleasePath; > virPidFileWrite; > diff --git a/src/util/virpidfile.c b/src/util/virpidfile.c > index 7069f8343d..b8bb455e5e 100644 > --- a/src/util/virpidfile.c > +++ b/src/util/virpidfile.c > @@ -302,6 +302,40 @@ int virPidFileReadIfAlive(const char *dir, > return 0; > } > > +/** > + * virPidFileReadPathIfLocked: > + * @path: path to pidfile > + * @pid: variable to return pid in > + * > + * This will attempt to read a pid from @path, and store it > + * in @pid. The @pid will only be set, however, if the > + * pid in @path is running, and @path is locked by virFileLock() > + * at byte 0. This adds protection against returning a stale pid. I'd mention here virCommandSetPidFile(), but otherwise looking good. Michal
