[Libguestfs] libguestfs 1.18.4 & 1.16.27 released (was: NOTICE: Data corruption bug)

[Richard W.M. Jones]

On Wed, Jul 04, 2012 at 05:28:05PM +0100, Richard W.M. Jones wrote:
> Versions of libguestfs which contain fixes will be announced
> separately.  It is likely that these versions will *require* qemu >= 1.1.0,
> so effectively our baseline version of qemu has just increased from
> 1.0 to 1.1.0, and this change is noted in the README file.

I've just pushed libguestfs stable releases 1.18.4 and 1.16.27 to the
website:

  http://libguestfs.org/download/1.16-stable/
  http://libguestfs.org/download/1.18-stable/

Upgrading is recommended, but read the rest of this email first.

Usually a stable point-release is supposed to be a simple, safe update
that will only fix bugs, because of our policy[1] of only cherry-
picking simple bug fixes.

  [1] http://libguestfs.org/guestfs.3.html#libguestfs_version_numbers

However in this case I have to urge some caution.  These releases
contain a fix for the qemu data corruption bug[2], but if your qemu
still has this bug then the new libguestfs will loudly report when
qemu crashes (instead of ignoring it).  This means that virt programs
that worked before, and the test suite, may fail where before they ran
successfully.

  [2] https://bugzilla.redhat.com/show_bug.cgi?id=836710

I thought this was better than ignoring potential data corruption.
The solution to this is to use qemu >= 1.1.0.

Furthermore, and again highly unusual for a point release, these
versions contain backports of three new APIs:

The first is guestfs_shutdown[3] which can be used from your program
to detect write/finalization failures linked to the qemu bug.  It is
not necessary, but it's recommended, to use this API from your
programs, as described here[4] and in the updated examples.

  [3] http://libguestfs.org/guestfs.3.html#guestfs_shutdown
  [4] http://libguestfs.org/guestfs.3.html#guestfs_close

The other two[5][6] are there because of a bugfix[7] to the inspection
code which I felt was important to include in the stable branches.

  [5] http://libguestfs.org/guestfs.3.html#guestfs_device_index
  [6] http://libguestfs.org/guestfs.3.html#guestfs_nr_devices
  [7] https://bugzilla.redhat.com/show_bug.cgi?id=627675

If there are any problems, please file bugs in the usual place.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
libguestfs lets you edit virtual machines.  Supports shell scripting,
bindings from many languages.  http://libguestfs.org