On Mon, May 15, 2017 at 03:41:45PM -0400, Shawn Webb wrote: > On Thu, Apr 20, 2017 at 10:43:14PM +0300, Konstantin Belousov wrote: > > Inodes are data structures corresponding to objects in a file system, > > such as files and directories. FreeBSD has historically used 32-bit > > values to identify inodes, which limits file systems to somewhat under > > 2^32 objects. Many modern file systems internally use 64-bit identifiers > > and FreeBSD needs to follow suit to properly and fully support these > > file systems. > > > > The 64-bit inode project, also known as ino64, started life many years > > ago as a project by Gleb Kurtsou (gleb_at_). After that time several > > people have had a hand in updating it and addressing regressions, after > > mckusick_at_ picked up and updated the patch, and acted as a flag-waver. > > > > Sponsored by the FreeBSD Foundation I have spent a significant effort > > on outstanding issues and integration -- fixing compat32 ABI, NFS and > > ZFS, addressing ABI compat issues and investigating and fixing ports > > failures. rmacklem_at_ provided feedback on NFS changes, emaste_at_ and > > jhb_at_ provided feedback and review on the ABI transition support. pho_at_ > > performed extensive testing and identified a number of issues that > > have now been fixed. kris_at_ performed an initial ports investigation > > followed by an exp-run by antoine_at_. emaste_at_ helped with organization > > of the process. > > > > This note explains how to perform useful testing of the ino64 branch, > > beyond typical smoke tests. > > > > 1. Overview. > > > > The ino64 branch extends the basic system types ino_t and dev_t from > > 32-bit to 64-bit, and nlink_t from 16-bit to 64-bit. The struct dirent > > layout is modified due to the larger size of ino_t, and also gains a > > d_off (directory offset) member. As ino64 implies an ABI change anyway > > the struct statfs f_mntfromname[] and f_mntonname[] array length > > MNAMELEN is increased from 88 to 1024, to allow for longer mount path > > names. > > > > ABI breakage is mitigated by providing compatibility using versioned > > symbols, ingenious use of the existing padding in structures, and by > > employing other tricks. Unfortunately, not everything can be fixed, > > especially outside the base system. For instance, third-party APIs > > which pass struct stat around are broken in backward and forward- > > incompatible way. > > > > 2. Motivation. > > > > The main risk of the ino64 change is the uncontrolled ABI breakage. > > Due to expansion of the basic types dev_t, ino_t and struct dirent, > > the impact is not limited to one part of the system, but affects: > > - kernel/userspace interface (syscalls ABI, mostly stat(2), kinfo > > and more) > > - libc interface (mostly related to the readdir(3), FTS(3)) > > - collateral damage in other libraries that happens to use changed types > > in the interfaces. See, for instance, libprocstat, for which compat > > was provided using symbol versioning, and libutil, which shlib version > > was bumped. > > > > 3. Quirks. > > > > We handled kinfo sysctl MIBs, but other MIBs which report structures > > depended on the changed type, are not handled in general. It was > > considered that the breakage is either in the management interfaces, > > where we usually allow ABI slip, or is not important. > > > > Struct xvnode changed layout, no compat shims are provided. > > > > For struct xtty, dev_t tty device member was reduced to uint32_t. It > > was decided that keeping ABI compat in this case is more useful than > > reporting 64bit dev_t, for the sake of pstat. > > > > 4. Testing procedure. > > > > The ino64 project can be tested by cloning the project branch from > > GitHub or by applying the patch <from the Phabricator review | located > > at URL | attached> to a working tree. The authorative source is the > > GitHub, I do not promise to update the review for each update. > > > > To clone from GitHub: > > % git clone -b ino64 https://github.com/FreeBSDFoundation/freebsd.git ino64 > > > > To fetch the patch from Phabricator: > > - Visit https://reviews.freebsd.org/D10439 > > - Click "Download Raw Diff" at the upper right of the page > > > > Or > > % arc patch D10439 > > > > After that, in the checkout directory do > > % (cd sys/kern && touch syscalls.master && make sysent) > > % (cd sys/compat/freebsd32 && touch syscalls.master && make sysent) > > If you use custom kernel configuration, ensure that > > options COMPAT_FREEBSD11 > > is included into the config. Then build world and kernel in the > > usual way, install kernel, reboot, install new world. Do not make > > shortcuts in the update procedure. > > Hey Kostik, > > On my HardenedBSD system, world compiled fine with the patch, but the > kernel didn't compile. I've uploaded the log to: > > https://hardenedbsd.org/~shawn/2017-05-15_ino64-r01.log > > This was from importing the patch from Phabricator into > hardened/current/master in HardenedBSD. Update: I missed a step. Kernel and world built fine. It seems the patch is working fine for me in a limited test. I'll do a more involved test tomorrow. Thanks, -- Shawn Webb Cofounder and Security Engineer HardenedBSD GPG Key ID: 0x6A84658F52456EEE GPG Key Fingerprint: 2ABA B6BD EF6A F486 BE89 3D9E 6A84 658F 5245 6EEE
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