On Thu, Feb 02, 2017 at 12:47:30PM +0000, Richard W.M. Jones wrote: > On Wed, Feb 01, 2017 at 04:54:01PM +0000, Daniel P. Berrange wrote: > > The virtlockd daemon has existed for years now, but we have never > > turned it on by default, requiring explicit user opt-in. This leaves > > users unprotected against accidents out of the box. > > > > By turning it on by default, users will at least be protected for > > mistakes involving local files, and files on shared filesystems > > that support fcntl() (eg NFS). > > What are the implications of this for passively reading > live disks? (a la tools such as virt-df) None - at this time, a disk marked <readonly/> won't acquire any locks. We map <readonly/> -> no lock <shareable/> -> fnctl read lock default -> fcntl write lock In future we'll likely copy the trick qemu has done to use a pair of fcntl locks on separate bytes, in order to map all combinations to locks. As long as you always mark disks <readonly/> though you should be fine no matter what we do. Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://entangle-photo.org -o- http://search.cpan.org/~danberr/ :| -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list
