VFS: introduce vfs_path_lookup() from newer kernels

Signed-off-by: Erez Zadok <ezk@cs.sunysb.edu>

diff --git a/fs/namei.c b/fs/namei.c
index 14aebc8fba6a6002d745ffb06ffe45556c10c766..d9cabaac5f1d0a06c8be969dca4ef39fc3a355e2 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1179,6 +1179,37 @@ int fastcall path_lookup(const char *name, unsigned int flags,
        return do_path_lookup(AT_FDCWD, name, flags, nd);
 }
 
+/**
+ * vfs_path_lookup - lookup a file path relative to a dentry-vfsmount pair
+ * @dentry:  pointer to dentry of the base directory
+ * @mnt: pointer to vfs mount of the base directory
+ * @name: pointer to file name
+ * @flags: lookup flags
+ * @nd: pointer to nameidata
+ */
+int vfs_path_lookup(struct dentry *dentry, struct vfsmount *mnt,
+                   const char *name, unsigned int flags,
+                   struct nameidata *nd)
+{
+       int retval;
+
+       /* same as do_path_lookup */
+       nd->last_type = LAST_ROOT;
+       nd->flags = flags;
+       nd->depth = 0;
+
+       nd->mnt = mntget(mnt);
+       nd->dentry = dget(dentry);
+
+       retval = path_walk(name, nd);
+       if (unlikely(!retval && !audit_dummy_context() && nd->dentry &&
+                               nd->dentry->d_inode))
+               audit_inode(name, nd->dentry->d_inode);
+
+       return retval;
+
+}
+
 static int __path_lookup_intent_open(int dfd, const char *name,
                unsigned int lookup_flags, struct nameidata *nd,
                int open_flags, int create_mode)
@@ -2777,6 +2808,7 @@ EXPORT_SYMBOL(__page_symlink);
 EXPORT_SYMBOL(page_symlink);
 EXPORT_SYMBOL(page_symlink_inode_operations);
 EXPORT_SYMBOL(path_lookup);
+EXPORT_SYMBOL(vfs_path_lookup);
 EXPORT_SYMBOL(path_release);
 EXPORT_SYMBOL(path_walk);
 EXPORT_SYMBOL(permission);

diff --git a/include/linux/namei.h b/include/linux/namei.h
index 5e4a22d4adc08b78dcdaf3851ef78e25c10f3deb..fd0b2b0918068ffd28129bf0dc4fffb7f7333b43 100644 (file)
--- a/include/linux/namei.h
+++ b/include/linux/namei.h
@@ -74,6 +74,8 @@ extern int FASTCALL(__user_walk_fd(int dfd, const char __user *, unsigned, struc
 extern int FASTCALL(path_lookup(const char *, unsigned, struct nameidata *));
 extern int FASTCALL(path_walk(const char *, struct nameidata *));
 extern int FASTCALL(link_path_walk(const char *, struct nameidata *));
+extern int vfs_path_lookup(struct dentry *, struct vfsmount *,
+                          const char *, unsigned int, struct nameidata *);
 extern void path_release(struct nameidata *);
 extern void path_release_on_umount(struct nameidata *);