1 files changed, 32 insertions, 0 deletions

diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index d3671f2acb29..8719bbe0dcc3 100644
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -44,6 +44,38 @@ renew_parental_timestamps(struct dentry *direntry)
         } while (!IS_ROOT(direntry));
 }
 
+char *
+cifs_build_path_to_root(struct smb_vol *vol, struct cifs_sb_info *cifs_sb,
+                        struct cifs_tcon *tcon)
+{
+        int pplen = vol->prepath ? strlen(vol->prepath) + 1 : 0;
+        int dfsplen;
+        char *full_path = NULL;
+
+        /* if no prefix path, simply set path to the root of share to "" */
+        if (pplen == 0) {
+                full_path = kzalloc(1, GFP_KERNEL);
+                return full_path;
+        }
+
+        if (tcon->Flags & SMB_SHARE_IS_IN_DFS)
+                dfsplen = strnlen(tcon->treeName, MAX_TREE_SIZE + 1);
+        else
+                dfsplen = 0;
+
+        full_path = kmalloc(dfsplen + pplen + 1, GFP_KERNEL);
+        if (full_path == NULL)
+                return full_path;
+
+        if (dfsplen)
+                strncpy(full_path, tcon->treeName, dfsplen);
+        full_path[dfsplen] = CIFS_DIR_SEP(cifs_sb);
+        strncpy(full_path + dfsplen + 1, vol->prepath, pplen);
+        convert_delimiter(full_path, CIFS_DIR_SEP(cifs_sb));
+        full_path[dfsplen + pplen] = 0; /* add trailing null */
+        return full_path;
+}
+
 /* Note: caller must free return buffer */
 char *
 build_path_from_dentry(struct dentry *direntry)