On Tue, Oct 04, 2016 at 10:57:49AM +0200, Kevin Wolf wrote: > Am 03.10.2016 um 13:07 hat Tomáš Golembiovský geschrieben: > > > > > > + if (((bs->drv != &bdrv_file) || !bs->read_only) && > > > > > > > > > > Why the check against bdrv_file ? > > > > > > > > To limit it only to files. Maybe there is better way to do that? The > > > > devices have a nasty habit to change the size. Sure, this can happen to > > > > file too, e.g. if somebody truncates the file outside QEMU. But that's > > > > rather a bad behaviour. For devices changing the size may be perfectly > > > > valid operation, e.g. replacing CD in drive or card in a card reader. > > > > > > The raw driver is usable over any storage backend (file, rbd, iscsi, > > > etc, etc) and it is valid to want to use a offset/size parameter in > > > combination with any of them. So we should not restrict it to just > > > files. > > Just to clear up some confusion here: There are the file/host_device/... > protocol drivers, which only access local files. These are implemented > in raw-posix.c, i.e. the file that this patch is touching. raw-win32.c > implements the same kind of file access for Windows.
This naming is constantly confusing - is there any appetite for renaming those to 'file-posix.c' and 'file-win32.c', and raw_bsd.c to raw.c ? 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/ :|