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Date: Thu, 21 Jan 2010 15:19:28 +0200
From: Naphtali Sprei <nsprei@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH v2 0/4] Modifications to the drives' readonly
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To: Christoph Hellwig <hch@lst.de>
Cc: qemu-devel@nongnu.org

Christoph Hellwig wrote:
> Looking at the version of this that landed in git I don't think the
> read-only handling is entirely clean after this.

I fixed what I could, still I got some questions below.

> 
>  - we now normally set the read_only flag from bdrv_open2 when we do
>    not have the O_RDWR flag set
>  - but the block drivers also mess with it:
>    	o raw-posix superflously sets it when BDRV_O_RDWR is not in the
> 	  open flags

Not sure where exactly is the issue. Can you please point the line ?

> 	o bochs, cloop, dmg and parallels set it unconditionally given
> 	  that they do not support writing at all.  But they do not
> 	  bother to reject opens without BDRV_O_RDWR

I just changed bochs and parallels not to ask for read-write.
Should all of them test the flags for RDWR and returns failure ?

> 	o vvfat as usual is a complete mess setting and clearing it in
> 	  various places

Fixed one occurance. More places ?

>  - in addition to that bdrv_open2 also sets it after calling itself for
>    the backing hd which seems superflous

Is this a problem ? I thought it's safer to mark it read-only, in case a write operation requested somehow.

>  - there also is a now unused bdrv_set_read_only helper to set it from
>    outside block.c

Done. Removed.

> 
> 

Thanks,

  Naphtali