On Fri, 2026-02-27 at 10:30 +0100, Christian König wrote: > On 2/26/26 16:55, Jeff Layton wrote: > > Christian said [1] to "just do it" when I proposed this, so here we are! > > > > For historical reasons, the inode->i_ino field is an unsigned long, > > which means that it's 32 bits on 32 bit architectures. This has caused a > > number of filesystems to implement hacks to hash a 64-bit identifier > > into a 32-bit field, and deprives us of a universal identifier field for > > an inode. > > > > This patchset changes the inode->i_ino field from an unsigned long to a > > u64. This shouldn't make any material difference on 64-bit hosts, but > > 32-bit hosts will see struct inode grow by at least 4 bytes. This could > > have effects on slabcache sizes and field alignment. > > > > The bulk of the changes are to format strings and tracepoints, since the > > kernel itself doesn't care that much about the i_ino field. The first > > patch changes some vfs function arguments, so check that one out > > carefully. > > > > With this change, we may be able to shrink some inode structures. For > > instance, struct nfs_inode has a fileid field that holds the 64-bit > > inode number. With this set of changes, that field could be eliminated. > > I'd rather leave that sort of cleanups for later just to keep this > > simple. > > > > Much of this set was generated by LLM, but I attributed it to myself > > since I consider this to be in the "menial tasks" category of LLM usage. > > Sounds reasonable to me, should get_next_ino() also be changed to return an > 64bit ino? >
I'm not opposed to doing that, but I'd probably leave that for a follow-on cleanup. Just doing the i_ino conversion is already making for a huge patchset. -- Jeff Layton <[email protected]>
