On Fri 26-07-19 12:44:34, Steve Magnani wrote: > Hi, > > On 7/12/19 5:02 AM, Pali Rohár wrote: > > In my opinion without support for additional layer, kernel should treat > > UDF Write-Once Access Type as read-only mount for userspace. And not > > classic read/write mount. > > > > ... > > > > It seems that udf.ko does not support updating VAT table, so probably it > > should treat also filesystem with VAT as read-only too. > > > > I thinkb085fbe2ef7fa7489903c45271ae7b7a52b0f9ab <https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/fs/udf?h=v5.1&id=b085fbe2ef7fa7489903c45271ae7b7a52b0f9ab>, deployed in 4.20, > does both of the things you want. > > One case I ran across today that Windows handles, but Linux doesn't, > is write-protection via flags in the DomainIdentifier fields of the > Logical Volume Descriptor and File Set Descriptor. Linux allows > RW mount when those are marked protected, but Windows forces RO mount. Yeah, you're right. We are currently completely ignoring the DomainIdentifier field and at least for read-write mounts we should make sure it is valid. So that's something that needs fixing. Honza -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR
