linux-ext4 - Re: [Cluster-devel] fallocate vs O

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, 16 Nov 2011 11:18:06 -0500
From:	Chris Mason <chris.mason@...cle.com>
To:	Jan Kara <jack@...e.cz>
Cc:	Christoph Hellwig <hch@...radead.org>,
	Steven Whitehouse <swhiteho@...hat.com>,
	linux-btrfs@...r.kernel.org, linux-ext4@...r.kernel.org,
	mfasheh@...e.com, jlbec@...lplan.org, cluster-devel@...hat.com
Subject: Re: [Cluster-devel] fallocate vs O_(D)SYNC

On Wed, Nov 16, 2011 at 04:57:55PM +0100, Jan Kara wrote:
> On Wed 16-11-11 08:42:34, Christoph Hellwig wrote:
> > On Wed, Nov 16, 2011 at 02:39:15PM +0100, Jan Kara wrote:
> > > > This would work fine with XFS and be equivalent to what it does for
> > > > O_DSYNC now.  But I'd rather see every filesystem do the right thing
> > > > and make sure the update actually is on disk when doing O_(D)SYNC
> > > > operations.
> > >   OK, I don't really have a strong opinion here. Are you afraid that just
> > > calling fsync() need not be enough to push all updates fallocate did to
> > > disk?
> > 
> > No, the point is that you should not have to call fsync when doing
> > O_SYNC I/O.  That's the whole point of it.
>   I agree with you that userspace shouldn't have to call fsync. What I
> meant is that sys_fallocate() or do_fallocate() can call
> generic_write_sync(file, pos, len), and that would be completely
> transparent to userspace.

We should do it per FS though, I'll patch up btrfs.

-chris
--
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