linux-ext4 - Re: [PATCH] ext4: Do not zeroout uninitialized extents beyond i

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <87d3whuus0.fsf@linux.vnet.ibm.com>
Date:	Thu, 27 May 2010 22:49:43 +0530
From:	"Aneesh Kumar K. V" <aneesh.kumar@...ux.vnet.ibm.com>
To:	Dmitry Monakhov <dmonakhov@...nvz.org>
Cc:	linux-ext4@...r.kernel.org, tytso@....edu
Subject: Re: [PATCH] ext4: Do not zeroout uninitialized extents beyond i_size

On Wed, 28 Apr 2010 11:38:58 +0400, Dmitry Monakhov <dmonakhov@...nvz.org> wrote:
> "Aneesh Kumar K. V" <aneesh.kumar@...ux.vnet.ibm.com> writes:
> 
> > On Fri,  9 Apr 2010 21:22:28 +0400, Dmitry Monakhov <dmonakhov@...nvz.org> wrote:
> >> Zerrout trick allow us to optimize cases where it is more reasonable
> >> to explicitly zeroout extent and mark it as initialized instead of
> >> splitting to several small ones.
> >> But this optimization is not acceptable is extent is beyond i_size
> >> Because it is not possible to have initialized blocks after i_size.
> >> Fsck treat this as incorrect inode size.
> >> 
> >
> > With commit c8d46e41bc744c8fa0092112af3942fcd46c8b18 if we set
> > EXT4_EOFBLOCKS_FL we should be able to have blocks beyond i_size.
> > May be the zero out path should set the flag instead of doing all these
> > changes. Zero-out is already complex with all the ENOSPC related
> > consideration. I guess we should try to keep it simple.
> For initialized extent beyond i_size? I've check fsck and seems that
> is truly possible. So this optimization allow us to avoid some 
> bad EIO situations. But we have to rework ext_get_blocks( ,create == 1)
> to clear EXT4_EOFBLOCKS_FL if last block of latest_extent is requested.
> I'll handle this.
> >


I thought this patch is going to reworked to use EOFBLOCKS_FL. But i see
Ted sent a pull request with the this patch. Did I miss something ?

-aneesh
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html