On Sun, Jun 7, 2015 at 3:02 AM, Eric W. Biederman <ebiederm@xxxxxxxxxxxx> wrote: > A nasty corner case to be aware of (and I think this is part of what Al > was warning about). /proc/sys/net is different depending upon which > current->nsproxy->net_ns. Ah, I'm beginning to grasp what's going on there: mulitple dentries with the same name but belonging to different namespaces, ->d_compare() being used to select the right one. Is that it? Overlayfs checks for d_compare() on the root of the lower and upper trees, but here it only set on a subdirectory of proc, not on every dentry. So overlayfs should be careful and check for DCACHE_OP_COMPARE | DCACHE_OP_HASH and reject going down such a dentry. Thanks, Miklos -- To unsubscribe from this list: send the line "unsubscribe linux-unionfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html