Re: [PATCH V2 1/6] namespaces: assign each namespace instance a serial number

On Tue, 2014-05-13 at 11:13 -0400, Richard Guy Briggs wrote: > On 14/05/13, Richard Guy Briggs wrote: > > On 14/05/10, Eric Paris wrote: > > > On Fri, 2014-05-09 at 20:27 -0400, Richard Guy Briggs wrote: > > > > Generate and assign a serial number per namespace instance since boot. > > > > > > > > Use a serial number per namespace (unique across one boot of one kernel) > > > > instead of the inode number (which is claimed to have had the right to change > > > > reserved and is not necessarily unique if there is more than one proc fs) to > > > > uniquely identify it per kernel boot. > > > > > > > > Signed-off-by: Richard Guy Briggs <rgb(a)redhat.com&gt; > > > > --- > > > > > > > +/** > > > > + * ns_serial - compute a serial number for the namespace > > > > + * > > > > + * Compute a serial number for the namespace to uniquely identify it in > > > > + * audit records. > > > > + */ > > > > +unsigned long long ns_serial(void) > > > > +{ > > > > + static DEFINE_SPINLOCK(serial_lock); > > > > + static unsigned long long serial = 4; /* reserved for IPC, UTS, user, PID */ > > > > + unsigned long flags; > > > > + > > > > + spin_lock_irqsave(&serial_lock, flags); > > > > + ++serial; > > > > + spin_unlock_irqrestore(&serial_lock, flags); > > > > + BUG_ON(!serial); > > > > + > > > > + return serial; > > > > +} > > > > + > > > > static inline struct nsproxy *create_nsproxy(void) > > > > { > > > > struct nsproxy *nsproxy; > > > > > > atomic64_t instead of doing it yourself? > > > > I'm willing to switch to atomic64_*. Thanks for pointing out its > > existence. > > Same would then go for using atomic_t in audit_serial(). Yup, moving to an atomic in audit_serial() looks like a good idea to me.