From: Allison Henderson <achender@linux.vnet.ibm.com>
To: djwong@us.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, 07 Oct 2011 10:59:30 -0700 [thread overview]
Message-ID: <4E8F3E02.7090203@linux.vnet.ibm.com> (raw)
In-Reply-To: <20111007172226.GF12447@tux1.beaverton.ibm.com>
On 10/07/2011 10:22 AM, Darrick J. Wong wrote:
> 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...)
Alrighty, sounds good to me.
>
>> + }
>> +
>> + 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?
Sorry, I borrowed this snippet from another area of code and forgot to update the error message. Will fix :)
>
> --D
> --
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next prev parent reply other threads:[~2011-10-07 17:59 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
2011-10-07 17:59 ` Allison Henderson [this message]
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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