On Fri, Oct 1, 2010 at 3:58 AM, Ram Pai <linuxram@xxxxxxxxxx> wrote: > > > > > @@ -1212,11 +1216,12 @@ struct vfsmount *copy_tree(struct vfsmount *mnt, struct dentry *dentry, > > > > > struct path path; > > > > > > > > > > if (!(flag & CL_COPY_ALL) && IS_MNT_UNBINDABLE(mnt)) > > > > > - return NULL; > > > > > + return ERR_PTR(-EINVAL); > > > > > > Ram, do you remember how this worked? > > > > Oops. That should be a OR condition. there is one other check in that > > function that should also be a OR condition. > > I may be wrong here. Can't exactly recollect what CL_COPY_ALL flag means. Al Viro > might remember? If CL_COPY_ALL means, to clone everything irrespective of any other > flags, then the above code seems right. CL_COPY_ALL means clone the mount despite MNT_UNBINDABLE. It is used for cloning the whole namespace and for collect_mounts(), both of which ignore MNT_UNBINDABLE. Of the two remaining callers of copy_tree() do_loopback already checks MNT_UNBINDABLE on the root of the tree to be copied. So that leaves the one in pnode.c. That one will be called when attaching a new mount or mount tree. If the root of that tree is unbindable then the propagation will fail with -ENOMEM which is wrong, it should simply skip the whole tree and not try to propagate. Calls which result in propagation are do_loopback, do_move_mount and do_add_mount. Of this do_loopback and do_move_mount already check for MNT_UNBINDABLE, do_add_mount doesn't check, but should probably just mask out MNT_UNBINDABLE. So in the end that check in copy_tree() should never actually trigger and can be turned into a WARN_ON Additionally the propagation code should perhaps be more defensive and skip MNT_UNBINDABLE source mounts. Thanks, Miklos -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
