On Thu, Jun 14, 2012 at 03:31:09PM -0700, Salman Qazi wrote: > An rmdir pushes css's ref count to zero. However, if the associated > directory is open at the time, the dentry ref count is non-zero. If > the fd for this directory is then passed into perf_event_open, it > does a css_get(). This bounces the ref count back up from zero. This > is a problem by itself. But what makes it turn into a crash is the > fact that we end up doing an extra dput, since we perform a dput > when css_put sees the ref count go down to zero. > > css_tryget does not fall into that trap. So, we use that instead. > ... > Signed-off-by: Salman Qazi <sqazi@xxxxxxxxxx> Acked-by: Tejun Heo <tj@xxxxxxxxxx> Peter, can you please pick up this one? Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
