On Tue, Aug 14, 2018 at 03:25:51PM +0800, Fam Zheng wrote: > Format drivers such as qcow2 don't allow sharing the same image between > two QEMU instances in order to prevent image corruptions, because of > metadata cache. LUKS driver don't modify metadata except for when > creating image, so it is safe to relax the permission. This makes > share-rw=on property work on virtual devices. > > Suggested-by: Daniel P. Berrangé <[email protected]> > Signed-off-by: Fam Zheng <[email protected]> > --- > block/crypto.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/block/crypto.c b/block/crypto.c > index 146d81c90a..33ee01bebd 100644 > --- a/block/crypto.c > +++ b/block/crypto.c > @@ -627,7 +627,9 @@ BlockDriver bdrv_crypto_luks = { > .bdrv_probe = block_crypto_probe_luks, > .bdrv_open = block_crypto_open_luks, > .bdrv_close = block_crypto_close, > - .bdrv_child_perm = bdrv_format_default_perms, > + /* This driver doesn't modify LUKS metadata except when creating image. > + * Allow share-rw=on as a special case. */ > + .bdrv_child_perm = bdrv_filter_default_perms, > .bdrv_co_create = block_crypto_co_create_luks, > .bdrv_co_create_opts = block_crypto_co_create_opts_luks, > .bdrv_co_truncate = block_crypto_co_truncate,
Reviewed-by: Daniel P. Berrangé <[email protected]> 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 :|
