On Thu, Jan 18, 2018 at 01:51:36PM -0600, Eric Blake wrote: > On 01/18/2018 04:31 AM, Daniel P. Berrange wrote: > > If the bdrv_reopen_prepare helper isn't provided, the qemu-img commit > > command fails to re-open the base layer after committing changes into > > it. Provide a no-op implementation for the LUKS driver, since there > > is not any custom work that needs doing to re-open it. > > > > Signed-off-by: Daniel P. Berrange <berra...@redhat.com> > > --- > > block/crypto.c | 7 +++++++ > > 1 file changed, 7 insertions(+) > > I'm hoping another block-layer expert chimes in, as I'm not quite sure > what the full reopen rules are; but the idea makes sense to me.
Yeah, likewise - it is hard to understand what is required, but I see lots of other block drivers just put a no-op impl here. I'm relying on Kevin/Max to tell me if i'm wrong here > > diff --git a/block/crypto.c b/block/crypto.c > > index 60ddf8623e..bb9a8f5376 100644 > > --- a/block/crypto.c > > +++ b/block/crypto.c > > @@ -382,6 +382,12 @@ static void block_crypto_close(BlockDriverState *bs) > > qcrypto_block_free(crypto->block); > > } > > > > +static int block_crypto_reopen_prepare(BDRVReopenState *state, > > + BlockReopenQueue *queue, Error > > **errp) > > +{ > > + /* nothing needs checking */ > > Are we sure that even changes such as moving from read-only to > read-write need no checking? LUKS doesn't do anything differently with ro vs rw images, so I'm assuming any such checks are handled by the layer below. > > > + return 0; > > +} > > > > /* > > * 1 MB bounce buffer gives good performance / memory tradeoff > > @@ -620,6 +626,7 @@ BlockDriver bdrv_crypto_luks = { > > .bdrv_truncate = block_crypto_truncate, > > .create_opts = &block_crypto_create_opts_luks, > > > > + .bdrv_reopen_prepare = block_crypto_reopen_prepare, > > .bdrv_refresh_limits = block_crypto_refresh_limits, > > .bdrv_co_preadv = block_crypto_co_preadv, > > .bdrv_co_pwritev = block_crypto_co_pwritev, Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|