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Date: Wed, 9 Nov 2005 23:22:57 +0000 (GMT)
From: Anton Altaparmakov <aia21@cam.ac.uk>
To: Dave Kleikamp <shaggy@austin.ibm.com>
cc: Andrew Morton <akpm@osdl.org>, linux-kernel@vger.kernel.org,
       linux-fsdevel@vger.kernel.org, hch@lst.de
Subject: Re: [PATCH] Remove read-only check from inode_update_time().
In-Reply-To: <1131577451.21652.10.camel@kleikamp.austin.ibm.com>
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 <1131577451.21652.10.camel@kleikamp.austin.ibm.com>
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On Wed, 9 Nov 2005, Dave Kleikamp wrote:
> On Wed, 2005-11-09 at 22:48 +0000, Anton Altaparmakov wrote:
> > Hi Andrew,
> > 
> > The read-only check in inode_update_time() (or file_update_time() as it is 
> > now in -mm) is unnecessary as the VFS better have done all the read-only 
> > checks and aborted much earlier in the file write code paths where 
> > inode/file_update_time() is only called from.
> 
> I notice inode_update_time is called from pipe_writev.  I don't know how
> likely it would be in practice, but wouldn't it be possible to write to
> a pipe on a read-only partition?  In that case the read-only check still
> makes sense.

It would still make sense but only if you can write to a pipe on a 
read-only partition which I have always assumed is not possible.

However, now that you queried this, I went and tried it and yes, you can 
write to a named pipe after remounting read-only, so you are right, the 
check does make sense in this case.  One learns something new every day.  
(-:

Andrew, please do not apply my patch...

Best regards,

	Anton
-- 
Anton Altaparmakov <aia21 at cam.ac.uk> (replace at with @)
Unix Support, Computing Service, University of Cambridge, CB2 3QH, UK
Linux NTFS maintainer / IRC: #ntfs on irc.freenode.net
WWW: http://linux-ntfs.sf.net/ & http://www-stu.christs.cam.ac.uk/~aia21/
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