2007-01-31 14:54:15

by Harry Papaxenopoulos

[permalink] [raw]
Subject: [Resubmit][PATCH 3/5] Secure Deletion and Trash-Bin Support for Ext4

Trash-Bin Functionality for the ext3 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/ext3/super.c
===================================================================
--- sdfs.orig/src/linux-2.6.20-rc6-trashbin/fs/ext3/super.c
+++ sdfs/src/linux-2.6.20-rc6-trashbin/fs/ext3/super.c
@@ -35,6 +35,7 @@
#include <linux/namei.h>
#include <linux/quotaops.h>
#include <linux/seq_file.h>
+#include <linux/trashbin.h>

#include <asm/uaccess.h>

@@ -1773,6 +1774,11 @@ static int ext3_fill_super (struct super
goto failed_mount4;
}

+#ifdef CONFIG_EXT3_FS_TRASHBIN
+ if ((sb->s_flags & MNT_TRASHBIN) && vfs_create_trash_bin(sb))
+ goto failed_mount4;
+#endif
+
ext3_setup_super (sb, es, sb->s_flags & MS_RDONLY);
/*
* akpm: core read_super() calls in here with the superblock locked.
Index: sdfs/src/linux-2.6.20-rc6-trashbin/fs/ext3/namei.c
===================================================================
--- sdfs.orig/src/linux-2.6.20-rc6-trashbin/fs/ext3/namei.c
+++ sdfs/src/linux-2.6.20-rc6-trashbin/fs/ext3/namei.c
@@ -37,6 +37,8 @@
#include <linux/buffer_head.h>
#include <linux/bio.h>
#include <linux/smp_lock.h>
+#include <linux/mount.h>
+#include <linux/trashbin.h>

#include "namei.h"
#include "xattr.h"
@@ -2079,6 +2081,10 @@ static int ext3_unlink(struct inode * di
struct buffer_head * bh;
struct ext3_dir_entry_2 * de;
handle_t *handle;
+ int trashed = 0;
+#ifdef CONFIG_EXT3_FS_TRASHBIN
+ struct dentry *user_dentry = NULL;
+#endif

/* Initialize quotas before so that eventual writes go
* in separate transaction */
@@ -2107,13 +2113,41 @@ static int ext3_unlink(struct inode * di
inode->i_ino, inode->i_nlink);
inode->i_nlink = 1;
}
- retval = ext3_delete_entry(handle, dir, de, bh);
+#ifdef CONFIG_EXT3_FS_TRASHBIN
+ if ((dentry->d_inode->i_sb->s_flags & MNT_TRASHBIN) &&
+ (EXT3_I(dentry->d_inode)->i_flags &
+ (EXT3_UNRM_FL | EXT3_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)) {
+ retval = PTR_ERR(user_dentry);
+ user_dentry = NULL;
+ goto end_unlink;
+ }
+
+ if (inode->i_nlink == 1 && user_dentry->d_inode &&
+ user_dentry->d_inode->i_ino != dir->i_ino) {
+ retval = vfs_trash_entry(dir, dentry);
+ trashed = 1;
+ }
+ }
+#endif
+ if (!trashed)
+ retval = ext3_delete_entry(handle, dir, de, bh);
if (retval)
goto end_unlink;
dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC;
ext3_update_dx_flag(dir);
ext3_mark_inode_dirty(handle, dir);
- drop_nlink(inode);
+ if (!trashed)
+ drop_nlink(inode);
if (!inode->i_nlink)
ext3_orphan_add(handle, inode);
inode->i_ctime = dir->i_ctime;
@@ -2122,6 +2156,10 @@ static int ext3_unlink(struct inode * di

end_unlink:
ext3_journal_stop(handle);
+#ifdef CONFIG_EXT4DEV_FS_TRASHBIN
+ if (user_dentry)
+ dput(user_dentry);
+#endif
brelse (bh);
return retval;
}
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
@@ -153,6 +153,15 @@ config EXT3_FS_SECURITY
If you are not using a security module that requires using
extended attributes for file security labels, say N.

+config EXT3_FS_TRASHBIN
+ bool "Ext3 trashbin functionality"
+ depends on TRASHBIN
+ depends on EXT3_FS
+ help
+ Trashbin functionality for the ext3 filesystem
+
+ If unsure, say N.
+
config EXT4DEV_FS
tristate "Ext4dev/ext4 extended fs support development (EXPERIMENTAL)"
depends on EXPERIMENTAL