[CIFS] Can not mount with prefixpath if root directory of share is inaccessible
Windows allows you to deny access to the top of a share, but permit access to
a directory lower in the path. With the prefixpath feature of cifs
(ie mounting \\server\share\directory\subdirectory\etc.) this should have
worked if the user specified a prefixpath which put the root of the mount
at a directory to which he had access, but we still were doing a lookup
on the root of the share (null path) when we should have been doing it on
the prefixpath subdirectory.
This fixes Samba bug # 5925
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index ff8c68d..b8821b0 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -1,7 +1,7 @@
/*
* fs/cifs/inode.c
*
- * Copyright (C) International Business Machines Corp., 2002,2007
+ * Copyright (C) International Business Machines Corp., 2002,2008
* Author(s): Steve French (sfrench@us.ibm.com)
*
* This library is free software; you can redistribute it and/or modify
@@ -621,6 +621,47 @@
.lookup = cifs_lookup,
};
+static char *build_path_to_root(struct cifs_sb_info *cifs_sb)
+{
+ int pplen = cifs_sb->prepathlen;
+ int dfsplen;
+ char *full_path = NULL;
+
+ /* if no prefix path, simply set path to the root of share to "" */
+ if (pplen == 0) {
+ full_path = kmalloc(1, GFP_KERNEL);
+ if (full_path)
+ full_path[0] = 0;
+ return full_path;
+ }
+
+ if (cifs_sb->tcon && (cifs_sb->tcon->Flags & SMB_SHARE_IS_IN_DFS))
+ dfsplen = strnlen(cifs_sb->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, cifs_sb->tcon->treeName, dfsplen);
+ /* switch slash direction in prepath depending on whether
+ * windows or posix style path names
+ */
+ if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS) {
+ int i;
+ for (i = 0; i < dfsplen; i++) {
+ if (full_path[i] == '\\')
+ full_path[i] = '/';
+ }
+ }
+ }
+ strncpy(full_path + dfsplen, cifs_sb->prepath, pplen);
+ full_path[dfsplen + pplen] = 0; /* add trailing null */
+ return full_path;
+}
+
/* gets root inode */
struct inode *cifs_iget(struct super_block *sb, unsigned long ino)
{
@@ -628,6 +669,7 @@
struct cifs_sb_info *cifs_sb;
struct inode *inode;
long rc;
+ char *full_path;
inode = iget_locked(sb, ino);
if (!inode)
@@ -636,13 +678,17 @@
return inode;
cifs_sb = CIFS_SB(inode->i_sb);
- xid = GetXid();
+ full_path = build_path_to_root(cifs_sb);
+ if (full_path == NULL)
+ return ERR_PTR(-ENOMEM);
+ xid = GetXid();
if (cifs_sb->tcon->unix_ext)
- rc = cifs_get_inode_info_unix(&inode, "", inode->i_sb, xid);
+ rc = cifs_get_inode_info_unix(&inode, full_path, inode->i_sb,
+ xid);
else
- rc = cifs_get_inode_info(&inode, "", NULL, inode->i_sb, xid,
- NULL);
+ rc = cifs_get_inode_info(&inode, full_path, NULL, inode->i_sb,
+ xid, NULL);
if (rc && cifs_sb->tcon->ipc) {
cFYI(1, ("ipc connection - fake read inode"));
inode->i_mode |= S_IFDIR;
@@ -652,6 +698,7 @@
inode->i_uid = cifs_sb->mnt_uid;
inode->i_gid = cifs_sb->mnt_gid;
} else if (rc) {
+ kfree(full_path);
_FreeXid(xid);
iget_failed(inode);
return ERR_PTR(rc);
@@ -659,6 +706,7 @@
unlock_new_inode(inode);
+ kfree(full_path);
/* can not call macro FreeXid here since in a void func
* TODO: This is no longer true
*/