On Tuesday 15 January 2019 09:41:19 Jan Kara wrote: > On Tue 15-01-19 09:31:11, Pali Rohár wrote: > > On Monday 14 January 2019 19:07:35 Michael Sabolish wrote: > > > I can try and make a pull-request for udftune, and I can just copy the API for tune2fs. It would work something like: > > > > > > udftune -O read-only device (to set read-only access type) > > > > > > or: > > > > > > udftune -O ^read-only device (to clear read-only access type (aka set rw)) > > > > This API is ambiguous. What does it mean for ^read-only? In UDF you have > > following access types: overwritable, rewritable, writeonce, readonly, > > pseudo-overwritable, unknown. > > > > So you would need to know to which R/W access type to switch > > (overwritable, rewritable, writeonce or pseudo-overwritable). > > > > With information of media type, you could be able to guess correct > > access type. But for UDF images stored in VFS there is no media > > information. Also you can have uncommon setup, e.g. usage of CD-R > > writeonce setup on CD-R/W disc. So "autodetection" of media type would > > not work always correctly. > > > > So I think that it would be better to have following API: > > > > udftune --access-type=<new_access_type> > > > > or > > > > udftune --change-access-type=<new_access_type> > > > > I understand that you would like to have similar API as tune2fs, but UDF > > settings are too different from ext*. > > If you wanted to follow tune2fs interface, you can have e.g.: Question is if it is a good idea to follow this interface. > udftune -E access-type=<foo> > > Another question about the feature is - the access type is actually per > partition and there can be multiple partitions on UDF media. So I think we > need to specify the partition number in the command and <foo> has to > actually be something like <partition number>,<access_type>. Access type is stored in partition descriptor and in UDF (as opposite of ECMA-167) you can have only one partition descriptor. IIRC there is some exception when you have two partition descriptors, but then one have to be readonly and second virtual. -- Pali Rohár pali.rohar@xxxxxxxxx
