1
linux/arch/x86_64
David Howells afefdbb28a [PATCH] VFS: Make filldir_t and struct kstat deal in 64-bit inode numbers
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.

This patch:

Make filldir_t take a 64-bit inode number and struct kstat carry a 64-bit
inode number so that 64-bit inode numbers can be passed back to userspace.

The stat functions then returns the full 64-bit inode number where
available and where possible.  If it is not possible to represent the inode
number supplied by the filesystem in the field provided by userspace, then
error EOVERFLOW will be issued.

Similarly, the getdents/readdir functions now pass the full 64-bit inode
number to userspace where possible, returning EOVERFLOW instead when a
directory entry is encountered that can't be properly represented.

Note that this means that some inodes will not be stat'able on a 32-bit
system with old libraries where they were before - but it does mean that
there will be no ambiguity over what a 32-bit inode number refers to.

Note similarly that directory scans may be cut short with an error on a
32-bit system with old libraries where the scan would work before for the
same reasons.

It is judged unlikely that this situation will occur because modern glibc
uses 64-bit capable versions of stat and getdents class functions
exclusively, and that older systems are unlikely to encounter
unrepresentable inode numbers anyway.

[akpm: alpha build fix]
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-03 08:03:40 -07:00
..
boot [PATCH] Fix boot code head.S warning 2006-09-26 10:52:37 +02:00
crypto [CRYPTO] api: Get rid of flags argument to setkey 2006-09-21 11:41:02 +10:00
ia32 [PATCH] VFS: Make filldir_t and struct kstat deal in 64-bit inode numbers 2006-10-03 08:03:40 -07:00
kernel [PATCH] revert "insert IOAPIC(s) and Local APIC into resource map" 2006-10-02 19:46:18 -07:00
lib [PATCH] Fix zeroing on exception in copy_*_user 2006-09-26 10:52:39 +02:00
mm [PATCH] Generic ioremap_page_range: x86_64 conversion 2006-10-01 00:39:32 -07:00
oprofile [PATCH] Move Kprobes and Oprofile to "Instrumentation Support" menu 2005-11-07 07:53:35 -08:00
pci [PATCH] x86: Move direct PCI scanning functions out of line 2006-09-26 10:52:41 +02:00
defconfig [PATCH] Update defconfig 2006-09-30 01:47:54 +02:00
Kconfig [PATCH] Kprobes: Make kprobe modules more portable 2006-10-02 07:57:16 -07:00
Kconfig.debug [PATCH] lockdep: irqtrace subsystem, x86_64 support 2006-07-03 15:27:03 -07:00
Makefile [PATCH] i386/x86-64: Work around gcc bug with noreturn functions in unwinder 2006-09-26 10:52:41 +02:00