linux-ext4 - Re: [PATCH] ext4: block direct I/O writes during ext4

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]

Date:	Wed, 17 Jul 2013 14:27:10 -0400
From:	Theodore Ts'o <tytso@....edu>
To:	Jan Kara <jack@...e.cz>
Cc:	Ext4 Developers List <linux-ext4@...r.kernel.org>,
	stable@...r.kernel.org
Subject: Re: [PATCH] ext4: block direct I/O writes during ext4_truncate

On Tue, Jul 16, 2013 at 12:49:42PM -0400, Theodore Ts'o wrote:
> On Tue, Jul 16, 2013 at 05:46:58PM +0200, Jan Kara wrote:
> > and ext4_setattr() does (again under i_mutex):
> >                                         ext4_inode_block_unlocked_dio(inode);
> >                                         inode_dio_wait(inode);
> >                                         ext4_inode_resume_unlocked_dio(inode);
> 
> Ah, I missed this; thanks for pointing this out.

I took a closer look, and there are other code paths which call
ext4_truncate() which don't call ext4_inode_block_unlocked_dio() and
inode_dio_wait().  In particular, the orphan cleanup code and the
SETFLAGS ioctl.

I suspect the right answer is to move these these calls, and possibly
also the truncate_pagecache() call.

The other thing that we probably will want to do as a cleanup for the
next merge window is to look at merging more of the code paths for
ext4_punch_hole() and ext4_truncate().

Cheeers,

						- Ted
--
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