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See http://www.infradead.org/rpr.html Cc: Lennart Poettering , Mimi Zohar , David Howells , Andreas Dilger , containers@lists.linux-foundation.org, Tycho Andersen , Miklos Szeredi , smbarber@chromium.org, Christoph Hellwig , linux-ext4@vger.kernel.org, Mrunal Patel , Kees Cook , Arnd Bergmann , Jann Horn , selinux@vger.kernel.org, Josh Triplett , linux-fsdevel@vger.kernel.org, Alexander Viro , Andy Lutomirski , OGAWA Hirofumi , Geoffrey Thomas , James Bottomley , John Johansen , Theodore Tso , Seth Forshee , Dmitry Kasatkin , Stephen Smalley , Jonathan Corbet , linux-unionfs@vger.kernel.org, linux-security-module@vger.kernel.org, linux-audit@redhat.com, "Eric W. Biederman" , linux-api@vger.kernel.org, Casey Schaufler , Alban Crequy , linux-integrity@vger.kernel.org, Todd Kjos X-BeenThere: containers@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Linux Containers List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: containers-bounces@lists.linux-foundation.org Sender: "Containers" On Thu, Oct 29, 2020 at 01:32:23AM +0100, Christian Brauner wrote: > Introduce a new mount bind mount property to allow idmapping mounts. The > MOUNT_ATTR_IDMAP flag can be set via the new mount_setattr() syscall > together with a file descriptor referring to a user namespace. Shouldn't this go to the end of the series once all the infrastructure is in place? > +config IDMAP_MOUNTS > + bool "Support id mappings per mount" > + default n n is the default default. But why do we need a config option here anyway? > +#ifdef CONFIG_IDMAP_MOUNTS > + if (kattr->attr_set & MNT_IDMAPPED) { > + struct user_namespace *user_ns; > + struct vfsmount *vmnt; All the code here looks like it should go into a helper. > + struct user_namespace *user_ns = READ_ONCE(m->mnt.mnt_user_ns); > + WRITE_ONCE(m->mnt.mnt_user_ns, get_user_ns(kattr->userns)); More unreadable long lines. > + if (attr->attr_set & MOUNT_ATTR_IDMAP) { > + struct ns_common *ns; > + struct user_namespace *user_ns; > + struct file *file; > + > + file = fget(attr->userns); The code here looks like another candidate for a self contained helper. > + > +static inline struct user_namespace *mnt_user_ns(const struct vfsmount *mnt) > +{ > +#ifdef CONFIG_IDMAP_MOUNTS > + return READ_ONCE(mnt->mnt_user_ns); > +#else > + return &init_user_ns; > +#endif How is the READ_ONCE on a pointer going to work? _______________________________________________ Containers mailing list Containers@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/containers