Re: [Qemu-devel] [PATCH RFC 0/5] generic image locking and crash recovery

[Denis V. Lunev]

On 12/23/2015 11:09 AM, Fam Zheng wrote:
> On Wed, 12/23 10:46, Denis V. Lunev wrote:
> > This series of patches is aimed to prevent usage of image
> > file by different qemu instances. In case we are the first
> > instance, and option lock is lockfile, - we lock the image file,
> > and if check option is on, we check the file and fix it if
> > nessecary. If one of this two ops fails - the image is closed
> > with the error.
> >
> > Patchset is not polished at all! Sent for a discussion as an alternative
> > approach.
> I like this approach. The first two patches match what I was thinking of.
>
> Patch 5 is okay, the unclean flag reflects HEADER_INUSE_MAGIC in parallels
> header; unfortunately patch 4 is wrong because qcow2 lacks a counterpart flag
> in the format, and the patch only modified an in memory variable.  we have to
> add this as a compatible_features bit in order to support this operation.
yep :) this could be done, no problem.

> Didn't review very closely because at least one patch doesn't seem to compile.
> :)
>
> Fam
which compile error do you have?

I have double checked that it is compiled OK on

commit 5dc42c186d63b7b338594fc071cf290805dcc5a5
Merge: c595b21 7236975
Author: Peter Maydell <address@hidden>
Date:   Tue Dec 22 14:21:42 2015 +0000

    Merge remote-tracking branch 
'remotes/stefanha/tags/block-pull-request' into staging

    # gpg: Signature made Tue 22 Dec 2015 08:52:55 GMT using RSA key ID 
81AB73C8
    # gpg: Good signature from "Stefan Hajnoczi <address@hidden>"
    # gpg:                 aka "Stefan Hajnoczi <address@hidden>"

    * remotes/stefanha/tags/block-pull-request:
      sdhci: add optional quirk property to disable card 
insertion/removal interrupts
      sdhci: don't raise a command index error for an unexpected response
      sd: sdhci: Delete over-zealous power check
      scripts/gdb: Fix a python exception in mtree.py
      parallels: add format spec
      block/mirror: replace IOV_MAX with blk_get_max_iov()
      block: replace IOV_MAX with BlockLimits.max_iov
      block-backend: add blk_get_max_iov()
      block: add BlockLimits.max_iov field
      virtio-blk: trivial code optimization

    Signed-off-by: Peter Maydell <address@hidden>

Den