On Wed, May 27, 2020 at 10:08:06AM +0800, Qu Wenruo wrote: > > Changes since v2: > > - Select CONFIG_CRYPTO_HMAC and CONFIG_KEYS (kbuild robot) > > - Fix double free in error path > > - Fix memory leak in error path > > - Disallow nodatasum and nodatacow when authetication is use (Eric) > > Since we're disabling NODATACOW usages, can we also disable the > following features? > - v1 space cache > V1 space cache uses NODATACOW file to store space cache, althouhg it > has inline csum, but it's fixed to crc32c. So attacker can easily > utilize this hole to mess space cache, and do some DoS attack. That's a good point. The v1 space cache will be phased out but it won't be in a timeframe we'll get in the authentication. At this point we don't even have a way to select v2 at mkfs time (it's work in progress though), so it would be required to switch to v2 on the first mount. > - fallocate > I'm not 100% sure about this, but since nodatacow is already a second > class citizen in btrfs, maybe not supporting fallocate is not a > strange move. Fallocate is a standard file operation, not supporting would be quite strange. What's the problem with fallocate and authentication?
