Received: (at 15347) by debbugs.gnu.org; 29 Oct 2013 15:05:21 +0000 From debbugs-submit-bounces <at> debbugs.gnu.org Tue Oct 29 11:05:21 2013 Received: from localhost ([127.0.0.1]:51275 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from <debbugs-submit-bounces <at> debbugs.gnu.org>) id 1VbArA-0002TE-It for submit <at> debbugs.gnu.org; Tue, 29 Oct 2013 11:05:20 -0400 Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.120]:55357) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from <psusi@HIDDEN>) id 1VbAr7-0002Sl-6F for 15347 <at> debbugs.gnu.org; Tue, 29 Oct 2013 11:05:17 -0400 X-Authority-Analysis: v=2.0 cv=dZcCLAre c=1 sm=0 a=/DbS/tiKggfTkRRHPZEB4g==:17 a=Qsx_du5GiBkA:10 a=sCfsyOEanakA:10 a=kehnMYD-ef0A:10 a=S1A5HrydsesA:10 a=8nJEP1OIZ-IA:10 a=fxJcL_dCAAAA:8 a=KGjhK52YXX0A:10 a=_hPDvjQ2ZHgA:10 a=20KFwNOVAAAA:8 a=QfKxxUxMAAAA:8 a=dsuz2wcTK2QiKA7Ud5UA:9 a=wPNLvfGTeEIA:10 a=jEp0ucaQiEUA:10 a=/DbS/tiKggfTkRRHPZEB4g==:117 X-Cloudmark-Score: 0 X-Authenticated-User: X-Originating-IP: 67.78.168.186 Received: from [67.78.168.186] ([67.78.168.186:54465] helo=[10.1.1.236]) by cdptpa-oedge01.mail.rr.com (envelope-from <psusi@HIDDEN>) (ecelerity 2.2.3.46 r()) with ESMTP id 20/6D-00725-7AECF625; Tue, 29 Oct 2013 15:05:11 +0000 Message-ID: <526FCEA7.9000902@HIDDEN> Date: Tue, 29 Oct 2013 11:05:11 -0400 From: Phillip Susi <psusi@HIDDEN> User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:17.0) Gecko/20130801 Thunderbird/17.0.8 MIME-Version: 1.0 To: "Brian C. Lane" <bcl@HIDDEN> Subject: Re: bug#15347: [PATCH 18/19] libparted: Flush parent device on open (#962611) References: <1378927509-15215-1-git-send-email-bcl@HIDDEN> <1378927509-15215-19-git-send-email-bcl@HIDDEN> In-Reply-To: <1378927509-15215-19-git-send-email-bcl@HIDDEN> X-Enigmail-Version: 1.5.2 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Spam-Score: 0.0 (/) X-Debbugs-Envelope-To: 15347 Cc: 15347 <at> debbugs.gnu.org X-BeenThere: debbugs-submit <at> debbugs.gnu.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: <debbugs-submit.debbugs.gnu.org> List-Unsubscribe: <http://debbugs.gnu.org/cgi-bin/mailman/options/debbugs-submit>, <mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=unsubscribe> List-Archive: <http://debbugs.gnu.org/cgi-bin/mailman/private/debbugs-submit/> List-Post: <mailto:debbugs-submit <at> debbugs.gnu.org> List-Help: <mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=help> List-Subscribe: <http://debbugs.gnu.org/cgi-bin/mailman/listinfo/debbugs-submit>, <mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=subscribe> Errors-To: debbugs-submit-bounces <at> debbugs.gnu.org Sender: "Debbugs-submit" <debbugs-submit-bounces <at> debbugs.gnu.org> X-Spam-Score: 0.0 (/) -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 I believe I know why this seems to work for you, and how to show that it doesn't: If you run mkfs on the partition and it is the only thing that has an open handle to it, when it exits, the kernel automatically flushes the partition. If you have another process with an open fd to the partition ( sleep 300 < /dev/sda1 & ) then you can run mkfs immediately followed by parted print, and it should read the stale data, since the partition is not flushed when mkfs exits, due to the other open handle. On 9/11/2013 3:25 PM, Brian C. Lane wrote: > From: "Brian C. Lane" <bcl@HIDDEN> > > Parted probes for filesystems using geometry offsets into the > parent device, not the partition device itself. This means it may > get stale information if a partition has just been formatted. > > On kernels before 2.6 this will also flush all partition devices. > On 2.6 and newer kernels it will only flush the parent device. > > * libparted/arch/linux.c (linux_open): Always call _flush_cache > --- libparted/arch/linux.c | 4 +--- 1 file changed, 1 insertion(+), > 3 deletions(-) > > diff --git a/libparted/arch/linux.c b/libparted/arch/linux.c index > 375be83..492f828 100644 --- a/libparted/arch/linux.c +++ > b/libparted/arch/linux.c @@ -1669,9 +1669,7 @@ retry: > dev->read_only = 0; } > > - /* With kernels < 2.6 flush cache for cache coherence > issues */ - if (!_have_kern26()) - > _flush_cache (dev); + _flush_cache (dev); > > return 1; } > -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.17 (MingW32) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBAgAGBQJSb86mAAoJEJrBOlT6nu75XagIAMD1i+OXsK3QvE82DpLOby+7 UaB0SFXkr2Er0Mcwx1oSA4hctMOLfz0BaMPWDiy28LLafyvmY56uwP0K8i7d4jjo PSN1RqpJUfkUhk6JYj1EalqHBv0/YT4ZjPLSKrVfJEziQPq0/wlQMSrNH3GJ4vc6 LZzTctS4v4LLXb1p0KHFq09RwD16c8xJW/5vzZy60nNnn+4SoIRjF8EU2MSi8nQ9 EJpf3F9JzIJX+x+6LLvyOtG+rgqQoyYS0BFHf5B3AYYwLAnEHDvKhC35uq53JtmX wPfv374jGH8PSuusNxdC/PiueqUNqaL30yAmyCcg6iwsHhk74DDICk2hgZpCxAY= =87SO -----END PGP SIGNATURE-----
bug-parted@HIDDEN:bug#15347; Package parted.
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From: "Brian C. Lane" <bcl@HIDDEN>
To: bug-parted@HIDDEN
Subject: [PATCH 18/19] libparted: Flush parent device on open (#962611)
Date: Wed, 11 Sep 2013 12:25:08 -0700
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From: "Brian C. Lane" <bcl@HIDDEN>
Parted probes for filesystems using geometry offsets into the parent
device, not the partition device itself. This means it may get stale
information if a partition has just been formatted.
On kernels before 2.6 this will also flush all partition devices. On 2.6
and newer kernels it will only flush the parent device.
* libparted/arch/linux.c (linux_open): Always call _flush_cache
---
libparted/arch/linux.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/libparted/arch/linux.c b/libparted/arch/linux.c
index 375be83..492f828 100644
--- a/libparted/arch/linux.c
+++ b/libparted/arch/linux.c
@@ -1669,9 +1669,7 @@ retry:
dev->read_only = 0;
}
- /* With kernels < 2.6 flush cache for cache coherence issues */
- if (!_have_kern26())
- _flush_cache (dev);
+ _flush_cache (dev);
return 1;
}
--
1.8.3.1
"Brian C. Lane" <bcl@HIDDEN>:bug-parted@HIDDEN.
Full text available.bug-parted@HIDDEN:bug#15347; Package parted.
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