Re: [Qemu-devel] [PATCH 09/10] block/qcow2: implement blockdev-amend

[Maxim Levitsky]

On Fri, 2019-09-06 at 15:12 +0100, Daniel P. Berrangé wrote:
> On Fri, Aug 30, 2019 at 11:56:07PM +0300, Maxim Levitsky wrote:
> > Currently only for changing crypto parameters
> > 
> > Signed-off-by: Maxim Levitsky <address@hidden>
> > ---
> >  block/qcow2.c        | 71 ++++++++++++++++++++++++++++++++++++++++++++
> >  qapi/block-core.json |  4 +--
> >  2 files changed, 73 insertions(+), 2 deletions(-)
> > 
> > diff --git a/block/qcow2.c b/block/qcow2.c
> > index 8dff4c6b5f..327d2afd9f 100644
> > --- a/block/qcow2.c
> > +++ b/block/qcow2.c
> > @@ -3082,6 +3082,18 @@ qcow2_co_create(BlockdevCreateOptions 
> > *create_options, Error **errp)
> >      assert(create_options->driver == BLOCKDEV_DRIVER_QCOW2);
> >      qcow2_opts = &create_options->u.qcow2;
> >  
> > +    if (!qcow2_opts->has_size) {
> > +        error_setg(errp, "Size is manadatory for image creation");
> > +        return -EINVAL;
> > +
> > +    }
> > +
> > +    if (!qcow2_opts->has_file) {
> > +        error_setg(errp, "'file' is manadatory for image creation");
> > +        return -EINVAL;
> > +
> > +    }
> > +
> >      bs = bdrv_open_blockdev_ref(qcow2_opts->file, errp);
> >      if (bs == NULL) {
> >          return -EIO;
> > @@ -5112,6 +5124,64 @@ static int qcow2_amend_options(BlockDriverState *bs, 
> > QemuOpts *opts,
> >      return 0;
> >  }
> >  
> > +
> > +static int coroutine_fn qcow2_co_amend(BlockDriverState *bs,
> > +                                       BlockdevCreateOptions *opts,
> > +                                       bool force,
> > +                                       Error **errp)
> > +{
> > +    BlockdevCreateOptionsQcow2 *qopts = &opts->u.qcow2;
> > +    BDRVQcow2State *s = bs->opaque;
> > +    int ret;
> > +
> > +    /*
> > +     * This is ugly as hell, in later versions of this patch
> > +     * something has to be done about this
> > +     */
> > +    if (qopts->has_file || qopts->has_size || qopts->has_data_file ||
> > +        qopts->has_data_file_raw || qopts->has_version ||
> > +        qopts->has_backing_file || qopts->has_backing_fmt ||
> > +        qopts->has_cluster_size || qopts->has_preallocation ||
> > +        qopts->has_lazy_refcounts || qopts->has_refcount_bits) {
> > +
> > +        error_setg(errp,
> > +                "Only LUKS encryption options can be amended for qcow2 
> > with blockdev-amend");
> > +        return -EOPNOTSUPP;
> > +
> > +    }
> > +
> > +    if (qopts->has_encrypt) {
> > +        if (!s->crypto) {
> > +            error_setg(errp, "QCOW2 image is not encrypted, can't amend");
> > +            return -EOPNOTSUPP;
> > +        }
> > +
> > +        if (qopts->encrypt->format != Q_CRYPTO_BLOCK_FORMAT_LUKS) {
> > +            error_setg(errp,
> > +                       "Amend can't be used to change the qcow2 encryption 
> > format");
> > +            return -EOPNOTSUPP;
> > +        }
> > +
> > +        if (s->crypt_method_header != QCOW_CRYPT_LUKS) {
> > +            error_setg(errp,
> > +                       "Only LUKS encryption options can be amended for 
> > qcow2 with blockdev-amend");
> > +            return -EOPNOTSUPP;
> > +        }
> > +
> > +        ret = qcrypto_block_amend_options(s->crypto,
> > +                                          qcow2_crypto_hdr_read_func,
> > +                                          qcow2_crypto_hdr_write_func,
> > +                                          bs,
> > +                                          qopts->encrypt,
> > +                                          force,
> > +                                          errp);
> > +        if (ret) {
> > +            return ret;
> > +        }
> > +    }
> > +    return 0;
> > +}
> > +
> >  /*
> >   * If offset or size are negative, respectively, they will not be included 
> > in
> >   * the BLOCK_IMAGE_CORRUPTED event emitted.
> > @@ -5304,6 +5374,7 @@ BlockDriver bdrv_qcow2 = {
> >      .mutable_opts        = mutable_opts,
> >      .bdrv_co_check       = qcow2_co_check,
> >      .bdrv_amend_options  = qcow2_amend_options,
> > +    .bdrv_co_amend       = qcow2_co_amend,
> >  
> >      .bdrv_detach_aio_context  = qcow2_detach_aio_context,
> >      .bdrv_attach_aio_context  = qcow2_attach_aio_context,
> > diff --git a/qapi/block-core.json b/qapi/block-core.json
> > index 02375fb59a..ba41744427 100644
> > --- a/qapi/block-core.json
> > +++ b/qapi/block-core.json
> > @@ -4312,10 +4312,10 @@
> >  # Since: 2.12
> >  ##
> >  { 'struct': 'BlockdevCreateOptionsQcow2',
> > -  'data': { 'file':             'BlockdevRef',
> > +  'data': { '*file':            'BlockdevRef',
> >              '*data-file':       'BlockdevRef',
> >              '*data-file-raw':   'bool',
> > -            'size':             'size',
> > +            '*size':            'size',
> >              '*version':         'BlockdevQcow2Version',
> >              '*backing-file':    'str',
> >              '*backing-fmt':     'BlockdevDriver',
> 
> Docs comment to say they  are mandatory for creation.
Done
> 
> 
> Regards,
> Daniel

Best regards,
        Maxim Levitsky