Messages in this thread | | | Date | Mon, 19 Nov 2012 19:02:23 +0800 | From | Gao feng <> | Subject | Re: [PATCH 05/11] pidns: Make the pidns proc mount/umount logic obvious. |
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于 2012年11月17日 00:35, Eric W. Biederman 写道: > From: "Eric W. Biederman" <ebiederm@xmission.com> > > Track the number of pids in the proc hash table. When the number of > pids goes to 0 schedule work to unmount the kernel mount of proc. > > Move the mount of proc into alloc_pid when we allocate the pid for > init. > > Remove the surprising calls of pid_ns_release proc in fork and > proc_flush_task. Those code paths really shouldn't know about proc > namespace implementation details and people have demonstrated several > times that finding and understanding those code paths is difficult and > non-obvious. > > Because of the call path detach pid is alwasy called with the > rtnl_lock held free_pid is not allowed to sleep, so the work to > unmounting proc is moved to a work queue. This has the side benefit > of not blocking the entire world waiting for the unnecessary > rcu_barrier in deactivate_locked_super. > > In the process of making the code clear and obvious this fixes a bug > reported by Gao feng <gaofeng@cn.fujitsu.com> where we would leak a > mount of proc during clone(CLONE_NEWPID|CLONE_NEWNET) if copy_pid_ns > succeeded and copy_net_ns failed. > > Acked-by: "Serge E. Hallyn" <serge@hallyn.com> > Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> > ---
Acked-by: Gao feng <gaofeng@cn.fujitsu.com> -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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