linux-ext4 - RE: libext2fs: don't flush to device opened in read-only mode

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Message-ID: <118AAB5F26BFB34DB5CDA7DA33334DB9B6065F@vmsk-exch-01.paragon-software.com>
Date:   Thu, 25 May 2017 05:50:18 +0000
From:   Konstantin Chistyakov <Konstantin.Chistyakov@...agon-software.com>
To:     Theodore Ts'o <tytso@....edu>
CC:     "linux-ext4@...r.kernel.org" <linux-ext4@...r.kernel.org>
Subject: RE: libext2fs: don't flush to device opened in read-only mode

Thanks for suggestion how to fix the bug correctly. Platform for reproducing: CYGWin build (x86, x64, cygwin1.dll v.2.8.0), Windows 8.1 x64 and Windows  10 x64 (x86 not tested).

-----Original Message-----
From: Theodore Ts'o [mailto:tytso@....edu] 
Sent: Thursday, May 25, 2017 12:56 AM
To: Konstantin Chistyakov <Konstantin.Chistyakov@...agon-software.com>
Cc: linux-ext4@...r.kernel.org
Subject: Re: libext2fs: don't flush to device opened in read-only mode

On Mon, May 22, 2017 at 09:48:00AM +0000, Konstantin Chistyakov wrote:
> From: Konstantin Chistyakov 
> <Konstantin.Chistyakov@...agon-software.com>
> Date: Tue, 19 May 2017 09:23:29 -0600
> Subject: [PATCH] libext2fs: don't flush to device opened in read-only 
> mode
> 
> From: Konstantin Chistyakov 
> <Konstantin.Chistyakov@...agon-software.com>
> 
> If the e2fsck is called with both -f -n options, the checking completing with a flushing error (retcode 8).
> 
> Catch error from the unix_flush() fsync(data->dev) when data->dev is opened in read-only mode:

I can't reproduce this problem.  What storage device or operating system are you using?

That being said, this is probably the wrong place to fix it.  The better fix is in e2fsck/unix.c, by adding a read-only test.

       	      	 		   	  - Ted