tree 259442e7fe16dcc53e51d0481074d92b4d845020
parent 770e0e0e808c6cd361c718ca1a936ed18864c69e
author Eric Blake <eblake@redhat.com> 1462677405 -0600
committer Max Reitz <mreitz@redhat.com> 1463060004 +0200

qemu-io: Add 'write -z -u' to test MAY_UNMAP flag

Make it easier to control whether the BDRV_REQ_MAY_UNMAP flag
can be passed through a write_zeroes command, by adding the '-u'
flag to qemu-io 'write -z' and 'aio_write -z'.  To be useful,
the device has to be opened with BDRV_O_UNMAP (done by default
in qemu-io, but can be made explicit with '-d unmap').

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 1462677405-4752-7-git-send-email-eblake@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>