Re: [PATCH v2] mount: dont execute propagate_umount() many times for same mounts

2016-10-10 Thread Andrei Vagin
On Thu, Oct 06, 2016 at 11:45:48PM -0500, Eric W. Biederman wrote: > Andrei Vagin writes: > > > On Thu, Oct 06, 2016 at 02:46:30PM -0500, Eric W. Biederman wrote: > >> Andrei Vagin writes: > >> > >> > The reason of this optimization is that umount() can hold namespace_sem > >> > for a long time

Re: [PATCH v2] mount: dont execute propagate_umount() many times for same mounts

2016-10-07 Thread Andrei Vagin
On Thu, Oct 06, 2016 at 02:46:30PM -0500, Eric W. Biederman wrote: > Andrei Vagin writes: > > > The reason of this optimization is that umount() can hold namespace_sem > > for a long time, this semaphore is global, so it affects all users. > > Recently Eric W. Biederman added a per mount namespac

Re: [PATCH v2] mount: dont execute propagate_umount() many times for same mounts

2016-10-06 Thread Eric W. Biederman
Andrei Vagin writes: > On Thu, Oct 06, 2016 at 02:46:30PM -0500, Eric W. Biederman wrote: >> Andrei Vagin writes: >> >> > The reason of this optimization is that umount() can hold namespace_sem >> > for a long time, this semaphore is global, so it affects all users. >> > Recently Eric W. Bieder

Re: [PATCH v2] mount: dont execute propagate_umount() many times for same mounts

2016-10-06 Thread Eric W. Biederman
Andrei Vagin writes: > The reason of this optimization is that umount() can hold namespace_sem > for a long time, this semaphore is global, so it affects all users. > Recently Eric W. Biederman added a per mount namespace limit on the > number of mounts. The default number of mounts allowed per m

[PATCH v2] mount: dont execute propagate_umount() many times for same mounts

2016-10-06 Thread Andrei Vagin
The reason of this optimization is that umount() can hold namespace_sem for a long time, this semaphore is global, so it affects all users. Recently Eric W. Biederman added a per mount namespace limit on the number of mounts. The default number of mounts allowed per mount namespace at 100,000. Curr