On Wed, 2020-01-08 at 03:24 -0800, Hugh Dickins wrote: > On Tue, 7 Jan 2020, Chris Mason wrote: > > On 7 Jan 2020, at 16:07, Dave Chinner wrote: > > > > > IOWs, there are *lots* of 64bit inode numbers out there on XFS > > > filesystems.... > > > > It's less likely in btrfs but +1 to all of Dave's comments. I'm happy > > to run a scan on machines in the fleet and see how many have 64 bit > > inodes (either buttery or x-y), but it's going to be a lot. > > Dave, Amir, Chris, many thanks for the info you've filled in - > and absolutely no need to run any scan on your fleet for this, > I think we can be confident that even if fb had some 15-year-old tool > in use on its fleet of 2GB-file filesystems, it would not be the one > to insist on a kernel revert of 64-bit tmpfs inos. > > The picture looks clear now: while ChrisD does need to hold on to his > config option and inode32/inode64 mount option patch, it is much better > left out of the kernel until (very unlikely) proved necessary. This approach seems like the best course to me. FWIW, at the time we capped this at 32-bits (2007), 64-bit machines were really just becoming widely available, and it was quite common to run 32-bit, non-LFS apps on a 64-bit kernel. Users were hitting spurious EOVERFLOW errors all over the place so this seemed like the best way to address it. The world has changed a lot since then though, and one would hope that almost everything these days is compiled with FILE_OFFSET_BITS=64. Fingers crossed! -- Jeff Layton <jlayton@xxxxxxxxxx>
