From: "Darrick J. Wong" <djwong@us.ibm.com>
To: Allison Henderson <achender@linux.vnet.ibm.com>
Cc: linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: [Ext4 Secure Delete 5/7v4] ext4: Secure Delete: Secure delete directory entry
Date: Fri, 7 Oct 2011 10:22:26 -0700 [thread overview]
Message-ID: <20111007172226.GF12447@tux1.beaverton.ibm.com> (raw)
In-Reply-To: <1317971465-8517-6-git-send-email-achender@linux.vnet.ibm.com>
On Fri, Oct 07, 2011 at 12:11:03AM -0700, Allison Henderson wrote:
> This patch zeros or randomizes a files directory entry when a file
<snip>
> @@ -1669,7 +1672,38 @@ static int ext4_delete_entry(handle_t *handle,
> de->inode = 0;
> dir->i_version++;
> BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
> - err = ext4_handle_dirty_metadata(handle, dir, bh);
> +
> + /*
> + * If the secure remove flag is on, zero
> + * or randomize the entry and write it out
> + * to the disk
> + */
> + if (flags & EXT4_DEL_ENTRY_ZERO) {
> + memset(de->name, 0x00, de->name_len);
> + de->file_type = 0;
> + } else if (flags & EXT4_DEL_ENTRY_RAND) {
> + get_random_bytes(de->name, de->name_len);
> + get_random_bytes(&(de->file_type),
> + sizeof(de->file_type));
Seeing as name_len and file_type precede name, you could probably reduce this
to one call that zaps all three. Same for the zero-out case.
Also you might want to make both of these name-erasing calls zap the space
between the end of the name and the end of the record, just in case there's old
filename component still lurking in that space. (Yes, paranoia...)
> + }
> +
> + if (flags & EXT4_DEL_ENTRY_ZERO ||
> + flags & EXT4_DEL_ENTRY_RAND) {
> +
> + set_buffer_dirty(bh);
> + sync_dirty_buffer(bh);
> + if (buffer_req(bh) && !buffer_uptodate(bh)) {
> + es->s_last_error_block =
> + cpu_to_le64(bh->b_blocknr);
> + ext4_error_inode(dir, __func__,
> + __LINE__, bh->b_blocknr,
> + "IO error syncing itable block");
itable?
--D
next prev parent reply other threads:[~2011-10-07 17:22 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-10-07 7:10 [Ext4 Secure Delete 0/7 v4] Ext4 secure delete Allison Henderson
2011-10-07 7:10 ` [Ext4 Secure Delete 1/7v4] ext4: Secure Delete: Add new EXT4_SECRM_RANDOM_FL flag Allison Henderson
2011-10-07 17:02 ` Darrick J. Wong
2011-10-07 17:14 ` Allison Henderson
2011-10-07 7:11 ` [Ext4 Secure Delete 2/7v4] ext4: Secure Delete: Add ext4_ind_hole_lookup function Allison Henderson
2011-10-07 17:47 ` Darrick J. Wong
2011-10-07 23:10 ` Allison Henderson
2011-10-07 7:11 ` [Ext4 Secure Delete 3/7v4] ext4: Secure Delete: Add secure delete functions Allison Henderson
2011-10-07 17:19 ` Allison Henderson
2011-10-07 18:07 ` Darrick J. Wong
2011-10-07 23:08 ` Allison Henderson
2011-10-07 7:11 ` [Ext4 Secure Delete 4/7v4] ext4: Secure Delete: Secure delete file data Allison Henderson
2011-10-07 7:11 ` [Ext4 Secure Delete 5/7v4] ext4: Secure Delete: Secure delete directory entry Allison Henderson
2011-10-07 17:22 ` Darrick J. Wong [this message]
2011-10-07 17:59 ` Allison Henderson
2011-10-07 7:11 ` [Ext4 Secure Delete 6/7v4] ext4: Secure Delete: Secure delete meta data blocks Allison Henderson
2011-10-07 7:11 ` [Ext4 Secure Delete 7/7v4] ext4/jbd2: Secure Delete: Secure delete journal blocks Allison Henderson
2011-10-07 18:35 ` Darrick J. Wong
2011-10-07 19:31 ` Sunil Mushran
2011-10-07 19:54 ` Eric Sandeen
2011-10-07 20:14 ` Allison Henderson
2011-10-07 19:55 ` Allison Henderson
2011-10-07 20:58 ` Darrick J. Wong
2011-10-08 0:06 ` Allison Henderson
2011-10-10 19:47 ` Jonathan Corbet
2011-10-10 23:35 ` Allison Henderson
2011-10-10 23:41 ` Jonathan Corbet
2011-10-11 0:54 ` Allison Henderson
2011-10-10 20:00 ` Jonathan Corbet
2011-10-10 23:36 ` Allison Henderson
2011-10-07 15:21 ` [Ext4 Secure Delete 0/7 v4] Ext4 secure delete Andreas Dilger
2011-10-07 17:07 ` Allison Henderson
2011-10-10 17:20 ` Allison Henderson
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