[PATCH 0/2] Use 64-bit inode numbers internally in the kernel [try #2]

[David Howells <dhowells@redhat.com>]

These patches make the kernel pass 64-bit inode numbers internally when
communicating to userspace, even on a 32-bit system.  They are required
because some filesystems have intrinsic 64-bit inode numbers: NFS3+ and XFS
for example.  The 64-bit inode numbers are then propagated to userspace
automatically where the arch supports it.

Problems have been seen with userspace (eg: ld.so) using the 64-bit inode
number returned by stat64() or getdents64() to differentiate files, and failing
because the 64-bit inode number space was compressed to 32-bits, and so
overlaps occur.


There are two patches:

 (1) Make struct kstat::ino and filldir_t's inode number argument u64 rather
     than ino_t and give an EOVERFLOW if an inode number can't be represented
     to userspace without shedding the top bits of the number.

 (2) Make NFS represent 64-bit fileids as 64-bit inode numbers to the VFS
     rather than compressing them to 32-bits on 32-bit systems.

David