linux-kernel - Re: btrfs: compression breaks cp and cross-FS mv, FS_IOC

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:	Mon, 14 Feb 2011 10:01:47 -0500
From:	Chris Mason <chris.mason@...cle.com>
To:	Josef Bacik <josef@...hat.com>
Cc:	Marti Raudsepp <marti@...fo.org>,
	btrfs hackers <linux-btrfs@...r.kernel.org>,
	Kernel hackers <linux-kernel@...r.kernel.org>
Subject: Re: btrfs: compression breaks cp and cross-FS mv, FS_IOC_FIEMAP bug?

Excerpts from Josef Bacik's message of 2011-02-13 11:13:30 -0500:
> On Sun, Feb 13, 2011 at 06:07:36PM +0200, Marti Raudsepp wrote:
> > On Sun, Feb 13, 2011 at 17:57, Josef Bacik <josef@...hat.com> wrote:
> > > Does the same problem happen when you use cp --sparse=never?
> > 
> > You are right. cp --sparse=never does not cause data loss.
> >
> 
> So fiemap probably isn't doing the right thing when compression is enabled,
> which doesn't suprise me since we don't do the right thing with delalloc either.
> I will try and get to this soon.  Thanks,

This might be a bug in the cp code.  We're setting the disk extent to
zero but setting different flags to say we're inline and compressed.
The cp fiemap code might be ignoring the flags?

Or, it could just be delalloc ;)

-chris
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/