Revert "Move xen patchset to new version's subdir."

[people/pmueller/ipfire-2.x.git] / src / patches / suse-2.6.27.25 / patches.apparmor / d_namespace_path.diff

From: Andreas Gruenbacher <agruen@suse.de>
Subject: Add d_namespace_path() to compute namespace relative pathnames

In AppArmor, we are interested in pathnames relative to the namespace root.
This is the same as d_path() except for the root where the search ends. Add
a function for computing the namespace-relative path.

Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Signed-off-by: John Johansen <jjohansen@suse.de>

---
 fs/namespace.c        |   30 ++++++++++++++++++++++++++++++
 include/linux/mount.h |    2 ++
 2 files changed, 32 insertions(+)

--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -2299,3 +2299,33 @@ void __put_mnt_ns(struct mnt_namespace *
 	release_mounts(&umount_list);
 	kfree(ns);
 }
+
+char *d_namespace_path(struct dentry *dentry, struct vfsmount *vfsmnt,
+		       char *buf, int buflen)
+{
+	struct path root, tmp, ns_root = { };
+	struct path path = { .mnt = vfsmnt, .dentry = dentry };
+	char *res;
+
+	read_lock(&current->fs->lock);
+	root = current->fs->root;
+	path_get(&current->fs->root);
+	read_unlock(&current->fs->lock);
+	spin_lock(&vfsmount_lock);
+	if (root.mnt)
+		ns_root.mnt = mntget(root.mnt->mnt_ns->root);
+	if (ns_root.mnt)
+		ns_root.dentry = dget(ns_root.mnt->mnt_root);
+	spin_unlock(&vfsmount_lock);
+	tmp = ns_root;
+	res = __d_path(&path, &tmp, buf, buflen,
+		       D_PATH_FAIL_DELETED | D_PATH_DISCONNECT);
+	path_put(&root);
+	path_put(&ns_root);
+
+	/* Prevent empty path for lazily unmounted filesystems. */
+	if (!IS_ERR(res) && *res == '\0')
+		*--res = '.';
+	return res;
+}
+EXPORT_SYMBOL(d_namespace_path);
--- a/include/linux/mount.h
+++ b/include/linux/mount.h
@@ -134,4 +134,6 @@ extern void mark_mounts_for_expiry(struc
 extern spinlock_t vfsmount_lock;
 extern dev_t name_to_dev_t(char *name);
 
+extern char *d_namespace_path(struct dentry *, struct vfsmount *, char *, int);
+
 #endif /* _LINUX_MOUNT_H */