lkml.org 
[lkml]   [2010]   [Feb]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 01/12] Miscellaneous functions and defines needed by AppArmor, including the base path resolution routines.
On Fri, Feb 19, 2010 at 01:36:17AM -0800, john.johansen@canonical.com wrote:

> +static int d_namespace_path(struct path *path, char *buf, int buflen,
> + char **name, int flags)
> +{
> + struct path root, tmp, ns_root = { };
> + char *res;
> + int deleted, connected;
> + int error = 0;
> +
> + read_lock(&current->fs->lock);
> + root = current->fs->root;
> + /* released below */
> + path_get(&root);
> + read_unlock(&current->fs->lock);
> +
> + spin_lock(&vfsmount_lock);
> + if (root.mnt && root.mnt->mnt_ns)
> + /* released below */
> + ns_root.mnt = mntget(root.mnt->mnt_ns->root);
> + if (ns_root.mnt)
> + /* released below */
> + ns_root.dentry = dget(ns_root.mnt->mnt_root);
> + spin_unlock(&vfsmount_lock);

Junk. You might as well leave ns_root {NULL, NULL} instead of that crap.

> + spin_lock(&dcache_lock);
> + /* There is a race window between path lookup here and the
> + * need to strip the " (deleted) string that __d_path applies
> + * Detect the race and relookup the path
> + *
> + * The stripping of (deleted) is a hack that could be removed
> + * with an updated __d_path

Yes, it could. Where's the patch doing just that? Or discussion of
desired interface, at lease...

> + if (flags & PATH_CHROOT_REL)
> + connected = tmp.dentry == root.dentry && tmp.mnt == root.mnt;
> + else
> + connected = tmp.dentry == ns_root.dentry &&
> + tmp.mnt == ns_root.mnt;
> +
> + if (!connected &&
> + !(flags & PATH_CONNECT_PATH) &&
> + !((flags & PATH_CHROOT_REL) && (flags & PATH_CHROOT_NSCONNECT) &&
> + (tmp.dentry == ns_root.dentry && tmp.mnt == ns_root.mnt))) {
> + /* disconnected path, don't return pathname starting with '/' */
> + error = -ESTALE;
> + if (*res == '/')
> + *name = res + 1;

Explanations, please.


\
 
 \ /
  Last update: 2010-02-19 12:05    [W:0.201 / U:0.012 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site