[Patch 3/6] Bind Mount Extensions 0.06

[Herbert Poetzl <herbert@13thfloor.at>]

;
; Bind Mount Extensions
;
; This part propagates the vfsmount into chown_common() to allow
; vfsmount based checks there, and verifies that the vfsmount
; isn't RDONLY (in chown_common)
;
; Copyright (C) 2003-2005 Herbert Pötzl <herbert@13thfloor.at>
;
; Changelog:
;
;   0.01  - broken out part from bme0.05
;
; this patch is free software; you can redistribute it and/or
; modify it under the terms of the GNU General Public License
; as published by the Free Software Foundation; either version 2
; of the License, or (at your option) any later version.
;
; this patch is distributed in the hope that it will be useful,
; but WITHOUT ANY WARRANTY; without even the implied warranty of
; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
; GNU General Public License for more details.
;

diff -NurpP --minimal linux-2.6.11-rc4-bme0.06-bm0.01-at0.01/fs/open.c linux-2.6.11-rc4-bme0.06-bm0.01-at0.01-cc0.01/fs/open.c
--- linux-2.6.11-rc4-bme0.06-bm0.01-at0.01/fs/open.c	2005-02-13 17:16:58 +0100
+++ linux-2.6.11-rc4-bme0.06-bm0.01-at0.01-cc0.01/fs/open.c	2005-02-19 06:31:43 +0100
@@ -661,7 +661,8 @@ out:
 	return error;
 }
 
-static int chown_common(struct dentry * dentry, uid_t user, gid_t group)
+static int chown_common(struct dentry *dentry, struct vfsmount *mnt,
+	uid_t user, gid_t group)
 {
 	struct inode * inode;
 	int error;
@@ -673,7 +674,7 @@ static int chown_common(struct dentry * 
 		goto out;
 	}
 	error = -EROFS;
-	if (IS_RDONLY(inode))
+	if (IS_RDONLY(inode) || MNT_IS_RDONLY(mnt))
 		goto out;
 	error = -EPERM;
 	if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
@@ -703,7 +704,7 @@ asmlinkage long sys_chown(const char __u
 
 	error = user_path_walk(filename, &nd);
 	if (!error) {
-		error = chown_common(nd.dentry, user, group);
+		error = chown_common(nd.dentry, nd.mnt, user, group);
 		path_release(&nd);
 	}
 	return error;
@@ -716,7 +717,7 @@ asmlinkage long sys_lchown(const char __
 
 	error = user_path_walk_link(filename, &nd);
 	if (!error) {
-		error = chown_common(nd.dentry, user, group);
+		error = chown_common(nd.dentry, nd.mnt, user, group);
 		path_release(&nd);
 	}
 	return error;
@@ -730,7 +731,7 @@ asmlinkage long sys_fchown(unsigned int 
 
 	file = fget(fd);
 	if (file) {
-		error = chown_common(file->f_dentry, user, group);
+		error = chown_common(file->f_dentry, file->f_vfsmnt, user, group);
 		fput(file);
 	}
 	return error;