From: Pavel Machek <pavel@ucw.cz>
To: Erik Paulson <epaulson@cs.wisc.edu>
Cc: linux-kernel@vger.kernel.org
Subject: Re: file changes without updating mtime
Date: Thu, 29 Jun 2006 13:11:01 +0200 [thread overview]
Message-ID: <20060629111037.GA1710@elf.ucw.cz> (raw)
In-Reply-To: <20060627181010.GE25040@cobalt.cs.wisc.edu>
On Tue 2006-06-27 13:10:10, Erik Paulson wrote:
>
> Hello -
>
> I'm seeing file content change without a change to the mtime for that
> file, and I'm trying to understand why.
>
> The filesystem is ext3, on a local IDE drive. It's a Centos 4.3 machine,
> with kernel version: 2.6.9-34.0.1.ELsmp
>
> A shell script that in a loop prints the date, stats the file, and then runs
> 'md5sum' gave me this output:
>
> Fri Jun 23 04:03:24 CDT 2006
> File: `/var/lib/rpm/__db.001'
> Size: 16384 Blocks: 32 IO Block: 4096 regular file
> Device: 303h/771d Inode: 6291609 Links: 1
> Access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root)
> Access: 2006-06-23 04:00:24.669054993 -0500
> Modify: 2006-06-18 21:42:43.685708137 -0500
> Change: 2006-06-18 21:42:43.685708137 -0500
> 37327d016d9741b0d74e4c9bd14d2956 /var/lib/rpm/__db.001
>
>
> Fri Jun 23 04:06:24 CDT 2006
> File: `/var/lib/rpm/__db.001'
> Size: 16384 Blocks: 32 IO Block: 4096 regular file
> Device: 303h/771d Inode: 6291609 Links: 1
> Access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root)
> Access: 2006-06-23 04:04:51.898420485 -0500
> Modify: 2006-06-18 21:42:43.685708137 -0500
> Change: 2006-06-18 21:42:43.685708137 -0500
> b2b25d452c94bb376f172e1789e8ab6e /var/lib/rpm/__db.001
>
>
> So something else read the file at 4:04:51, and apparently changed
> it.
I believe it is / was possible to change file using mmap without
affecting mtime. It might have been fixed in the meantime.
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
prev parent reply other threads:[~2006-06-29 11:36 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-06-27 18:10 file changes without updating mtime Erik Paulson
2006-06-28 13:38 ` Pádraig Brady
2006-06-29 11:11 ` Pavel Machek [this message]
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