[CRIU] [PATCH 1/1] do_new_mount() should clear all do_change_type() bits

[Tycho Andersen]

On Tue, Apr 14, 2015 at 08:24:48PM +0300, Pavel Emelyanov wrote:
> On 04/14/2015 08:15 PM, Oleg Nesterov wrote:
> > Pavel, did you miss this patch?
> 
> No, I didn't :)
> 
> > I agree with Tycho, we need to do something with restore_shared_options()
> > too. But afaics this needs another patch. In particular, It _seems__ to
> > me we should move these restore_shared_options() callsites into a single
> > callsite in do_mount_one().
> 
> Yes, but as Tycho is actively involved in the mount.c development, I
> was waiting for his explicit ACK or NACK. So far this thread to me
> looks as being under discussion. Is it?

Sorry, I was hoping we could resolve restore_shared_options() in this
patch, but we can apply it now and I can send something that fixes
that later:

Acked-by: Tycho Andersen <tycho.andersen at canonical.com>

> -- Pavel
> 
> > On 04/13, Oleg Nesterov wrote:
> >>
> >> do_new_mount() clears MS_SHARED but this is not enough. It should clear
> >> all bits processed in restore_shared_options().
> >>
> >> The patch also adds MS_UNBINDABLE to MS_CHANGE_TYPE_MASK even if it is
> >> not currently used. Just to match the kernel's do_change_type() check.
> >>
> >> Signed-off-by: Oleg Nesterov <oleg at redhat.com>
> >> ---
> >>  mount.c |    5 ++++-
> >>  1 files changed, 4 insertions(+), 1 deletions(-)
> >>
> >> diff --git a/mount.c b/mount.c
> >> index 8b57729..55d5f8b 100644
> >> --- a/mount.c
> >> +++ b/mount.c
> >> @@ -1750,6 +1750,9 @@ skip_parent:
> >>  	return 0;
> >>  }
> >>  
> >> +#define MS_CHANGE_TYPE_MASK	\
> >> +	(MS_SHARED | MS_PRIVATE | MS_SLAVE | MS_UNBINDABLE)
> >> +
> >>  static int do_new_mount(struct mount_info *mi)
> >>  {
> >>  	char *src;
> >> @@ -1760,7 +1763,7 @@ static int do_new_mount(struct mount_info *mi)
> >>  		return -1;
> >>  
> >>  	if (mount(src, mi->mountpoint, tp->name,
> >> -			mi->flags & (~MS_SHARED), mi->options) < 0) {
> >> +			mi->flags & ~MS_CHANGE_TYPE_MASK, mi->options) < 0) {
> >>  		pr_perror("Can't mount at %s", mi->mountpoint);
> >>  		return -1;
> >>  	}
> >> -- 
> >> 1.5.5.1
> >>
> > 
> > .
> > 
>