Re: [Qemu-devel] [PATCH v4 00/27] block: Lock images when opening

[Richard W.M. Jones]

On Tue, May 10, 2016 at 10:50:32AM +0800, Fam Zheng wrote:
> v4: Don't lock RO image. [Rich]

I applied this on top of HEAD and added some debugging messages to
block/raw-posix.c so I can see when files are being opened and locked,
and it does appear to do the right thing for read-only and
write-exclusive files, ie. it applies an exclusive lock when opening a
file for write-exclusive, and no lock when opening a file for read.

However I didn't test the write-shareable case (the libvirt
<shareable/> flag which should map to a shared lock -- is that right Dan?).

Rich.

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