2007-01-31 14:53:18

by Harry Papaxenopoulos

[permalink] [raw]
Subject: [Resubmit][PATCH 2/5] Secure Deletion and Trash-Bin Support for Ext4

Trash-Bin Functionality for the ext2 filesystem:

Signed-off-by: Harry Papaxenopoulos <[email protected]>
Signed-off-by: Nikolai Joukov <[email protected]>
Signed-off-by: Erez Zadok <[email protected]>

Index: sdfs/src/linux-2.6.20-rc6-trashbin/fs/ext2/super.c
===================================================================
--- sdfs.orig/src/linux-2.6.20-rc6-trashbin/fs/ext2/super.c
+++ sdfs/src/linux-2.6.20-rc6-trashbin/fs/ext2/super.c
@@ -29,6 +29,7 @@
#include <linux/vfs.h>
#include <linux/seq_file.h>
#include <linux/mount.h>
+#include <linux/trashbin.h>
#include <asm/uaccess.h>
#include "ext2.h"
#include "xattr.h"
@@ -934,6 +935,10 @@ static int ext2_fill_super(struct super_
if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
ext2_warning(sb, __FUNCTION__,
"mounting ext3 filesystem as ext2");
+#ifdef CONFIG_EXT2_FS_TRASHBIN
+ if ((sb->s_flags & MNT_TRASHBIN) && vfs_create_trash_bin(sb))
+ goto failed_mount3;
+#endif
ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY);
return 0;

Index: sdfs/src/linux-2.6.20-rc6-trashbin/fs/ext2/namei.c
===================================================================
--- sdfs.orig/src/linux-2.6.20-rc6-trashbin/fs/ext2/namei.c
+++ sdfs/src/linux-2.6.20-rc6-trashbin/fs/ext2/namei.c
@@ -31,6 +31,8 @@
*/

#include <linux/pagemap.h>
+#include <linux/mount.h>
+#include <linux/trashbin.h>
#include "ext2.h"
#include "xattr.h"
#include "acl.h"
@@ -256,19 +258,54 @@ static int ext2_unlink(struct inode * di
struct ext2_dir_entry_2 * de;
struct page * page;
int err = -ENOENT;
+ int trashed = 0;
+#ifdef CONFIG_EXT2_FS_TRASHBIN
+ struct dentry *user_dentry = NULL;
+#endif

de = ext2_find_entry (dir, dentry, &page);
if (!de)
goto out;
+#ifdef CONFIG_EXT2_FS_TRASHBIN
+ if ((dentry->d_inode->i_sb->s_flags & MNT_TRASHBIN) &&
+ (EXT2_I(dentry->d_inode)->i_flags &
+ (EXT2_UNRM_FL | EXT2_SECRM_FL))) {
+
+ /*
+ * We put this code here to optimize the common case. Since
+ * lookups are expensive, we try to reserve from making any,
+ * unless one of the trash-bin flags are set. The cleanest
+ * way though is to probably move this code outside the
+ * above if statement.
+ */
+ user_dentry = vfs_get_user_dentry(dir, 1);
+ if (IS_ERR(user_dentry)) {
+ err = PTR_ERR(user_dentry);
+ user_dentry = NULL;
+ goto out;
+ }

- err = ext2_delete_entry (de, page);
+ if (inode->i_nlink == 1 && user_dentry->d_inode &&
+ user_dentry->d_inode->i_ino != dir->i_ino) {
+ err = vfs_trash_entry(dir, dentry);
+ trashed = 1;
+ }
+ }
+#endif
+ if (!trashed)
+ err = ext2_delete_entry (de, page);
if (err)
goto out;

inode->i_ctime = dir->i_ctime;
- inode_dec_link_count(inode);
+ if (!trashed)
+ inode_dec_link_count(inode);
err = 0;
out:
+#ifdef CONFIG_EXT2_FS_TRASHBIN
+ if (user_dentry)
+ dput(user_dentry);
+#endif
return err;
}

Index: sdfs/src/linux-2.6.20-rc6-trashbin/fs/Kconfig
===================================================================
--- sdfs.orig/src/linux-2.6.20-rc6-trashbin/fs/Kconfig
+++ sdfs/src/linux-2.6.20-rc6-trashbin/fs/Kconfig
@@ -76,6 +76,15 @@ config FS_XIP
depends on EXT2_FS_XIP
default y

+config EXT2_FS_TRASHBIN
+ bool "Ext2 trashbin functionality"
+ depends on TRASHBIN
+ depends on EXT2_FS
+ help
+ Trashbin functionality for the ext2 filesystem
+
+ If unsure, say N.
+
config EXT3_FS
tristate "Ext3 journalling file system support"
select JBD