On Tue, 7 Dec 2010 06:44:21 +0000 "Hawrylewicz Czarnowski, Przemyslaw" <przemyslaw.hawrylewicz.czarnowski@xxxxxxxxx> wrote: > Neil, > > The one below is a fix for the problem we encounter quite often when we try to stop all arrays with mdadm -Ss. The main problem is that mdmon holds open container device and then exits. The time that system make clean up is quite long and mdadm invokes ARRAY_STOP ioctl when device is still opened. > Second resolution is to retry ioctl in mdadm after mdmon exits, but closing handle is I what should be done before process exist. > Take a look at the patch below: > > -- > Sometimes (~50%) mdadm -Ss cannot stop container as mdmon opens its device > and do not close it before exit(). The period between open and release of > handle is too long and md is not able stop device. Releasing handle before > exit does not block md. > > Signed-off-by: Przemyslaw Czarnowski <przemyslaw.hawrylewicz.czarnowski@xxxxxxxxx> I've applied this, but I'm not 100% sure it is completely safe. mdmon holds the O_EXCL open to be sure that mdadm isn't creating or assembling another array in the container. mdadm will get an O_EXCL and then try sending a signal to mdmon. If it succeeds, it knows mdmon is still running. But this patch might open a window where mdadm can get O_EXCL, and a signal still works. However I'm not certain that window wasn't already there, and this might just make it a bit bigger. I've put a note in my to-do list to look into this more closely and figure out if there is a problem, and if so, how to fix it. Thanks, NeilBrown > --- > monitor.c | 1 + > 1 files changed, 1 insertions(+), 0 deletions(-) > > diff --git a/monitor.c b/monitor.c > index 59b4181..f166bc8 100644 > --- a/monitor.c > +++ b/monitor.c > @@ -525,6 +525,7 @@ static int wait_and_act(struct supertype *container, int nowait) > remove_pidfile(container->devname); > exit_now = 1; > signal_manager(); > + close(fd); > exit(0); > } > } -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
