This also fixes the bug with MAP_SEM being potentially
interpreted as VM_SHARED.

This moves the mapping of PROT_* bits to VM_* bits from mmap.c to the
common header file <linux/mman.h>.  The mapping is needed for mprotect
too.

	old_decode_dev()/old_encode_dev() added where needed in other
filesystems.  Parts in different filesystems are independent, but IMO
it's not worse splitting into a dozen of half-kilobyte patches.

	nfs_fattr->rdev switched to dev_t; code that unpacks on-the-wire
attributes does explicit conversion now.

	HPFS code that uses EAs for storing i_rdev/i_mode/i_uid/i_gid
sanitized.

	Similar fix for UFS; touching device node (and they have 32bit
dev_t) ends up killing upper 16 bits, which makes for very unhappy
*BSD, since that turns /dev/ad0s1 into alias of /dev/ad0.  Again, for
now we store on-disk value in private part of inode and use it instead
of ->i_rdev in ->write_inode().

	Fix for JFS handling of device nodes; it has 32bit on-disk device
numbers, shoves them into 16bit (->i_rdev) when inode is read and writes
them back truncated when inode is written to disk.  For now (and 2.4 will
have to do the same permanently) we store the original value in private
part of inode and use it instead of ->i_rdev in ->write_inode(); mknod()
sets it at the same time as ->i_rdev.  It will become unnecessary when
dev_t becomes wider than 16 bits, but for now we need it.

	Fix for endianness bug in UDF: it writes major and minor as 32bit
host-endian and reads them as 32bit little-endian; obviously a bad idea
on big-endian boxen ;-)  Needed both for 2.4 and 2.6.

beginning of fs side work:
	* new helpers - old_valid_dev(), old_encode_dev() and old_decode_dev()
	* old_valid_dev() checks if dev_t value is OK for old filesystems
(i.e. both major and minor are below 256).
	* old_valid_dev() calls are added in ->mknod() instances that care
about dev_t values (disk-backed and network ones).
	* old_encode_dev() and old_decode_dev() convert dev_t -> u16
and u16 -> dev_t resp; currently these are no-ops, places that use current
formar (minor in bits 0--7, major in bits 8--15) will switch to these before
we widen dev_t.

	kdev_t, to_kdev_t(), etc. are gone - there is no more objects
of that type and no remaining callers of these functions.

	the last kdev_t object is gone; ->i_rdev switched to dev_t.

	tty redirect handling sanitized.  Such ttys (/dev/tty and
/dev/console) get a different file_operations; its ->write() handles
redirects; checks for file->f_op == &tty_fops updated, checks for
major:minor being that of a redirector replaced with check for
->f_op->write value.  Piece of code in tty_io.c that had been #if 0
since 0.99<something> had been finally put out of its misery. kdev_val()
is gone.

	cdevname() killed, there was only one remaining user
(tty_paranoia_check()) and in that case cdevname() was worse
than plain major:minor (basically, it's "you've got corrupted
inode that was supposed to belong to tty device; here's what
I'd found in ->i_rdev")

	cciss cleanup - instead of playing with device numbers, we add
helper functions that get host and drive structures by gendisk and use
them in open/ioctl/release, same as had been done for cpqarray.

	paride/pt.c cleanups - passing pointer to pt_unit instead of index
in array; same as had been done for pd/pcd/pf.

	floppy98 ->probe() forgot to set *part to 0; fixed.

	misc trivial cleanups

into home.osdl.org:/home/torvalds/v2.5/linux

- Don't write the current time back to the RTC on suspend - we may
  jump over a programmed wakeup alarm.
- Restore SA1100 GPIO output state

- Suspend and resume system devices.
- If device suspend fails, don't suspend.

Some ARM CPUs don't allow CP15 CR1 control register to be read.
Therefore, to ensure that the value hits the control register on
Xscale, read back the CP15 CR0 ID register instead.

On ARM, we oops when we detect that an interrupt handler has unbalanced
the preempt count.  We should restore the preempt count when we started
to handle the interrupt and then cause the oops.

* replace previously removed NULL context check
  (causes oops when opening non existent device)

* replace previously removed NULL context check
  (causes oops when opening non existent device)

* add RCC underrun handling
* fix stats output typo
* replace previously removed NULL context check
  (causes oops when opening non existent device)

This fixes a "miscompile" HP reported against gcc 3.3 with
-march-pentium4.  It turned out to be a non-complete asm contraint.  the
existing constraint on "opt" was on the address of "opt", which allowed
gcc to reorder the setting of the fields inside opt to beyond the asm
that uses it, which is less than useful at best.

This changes the way futexes are indexed, so that they don't pin pages. 
It also fixes some bugs with private mappings and COW pages.

Currently, all futexes look up the page at the userspace address and pin
it, using the pair (page,offset) as an index into a table of waiting
futexes.  Any page with a futex waiting on it remains pinned in RAM,
which is a problem when many futexes are used, especially with FUTEX_FD.

Another problem is that the page is not always the correct one, if it
can be changed later by a COW (copy on write) operation.  This can
happen when waiting on a futex without writing to it after fork(),
exec() or mmap(), if the page is then written to before attempting to
wake a futex at the same adress. 

There are two symptoms of the COW problem:
 - The wrong process can receive wakeups
 - A process can fail to receive required wakeups. 

This patch fixes both by changing the indexing so that VM_SHARED
mappings use the triple (inode,offset,index), and private mappings use
the pair (mm,virtual_address).

The former correctly handles all shared mappings, including tmpfs and
therefore all kinds of shared memory (IPC shm, /dev/shm and
MAP_ANON|MAP_SHARED).  This works because every mapping which is
VM_SHARED has an associated non-zero vma->vm_file, and hence inode.
(This is ensured in do_mmap_pgoff, where it calls shmem_zero_setup). 

The latter handles all private mappings, both files and anonymous.  It
isn't affected by COW, because it doesn't care about the actual pages,
just the virtual address.

The patch has a few bonuses:

        1. It removes the vcache implementation, as only futexes were
           using it, and they don't any more.

        2. Removing the vcache should make COW page faults a bit faster.

        3. Futex operations no longer take the page table lock, walk
           the page table, fault in pages that aren't mapped in the
           page table, or do a vcache hash lookup - they are mostly a
           simple offset calculation with one hash for the futex
           table.  So they should be noticably faster.

Special thanks to Hugh Dickins, Andrew Morton and Rusty Russell for
insightful feedback.  All suggestions are included.

into home.osdl.org:/home/torvalds/v2.5/linux

From Matias Alejo Garcia <kernel@matiu.com.ar>.

MODULE_ALIAS_LDISC() is not in any way architecture-specific, so don't
put it in architecture header files.

Here's a patch which moves it to a more sensible location.

The "insert_here" list pointer logic was broken, and unnecessary. 

Kill it and its associated logic off completely - just tell the IO
scheduler what kind of insert it is.

This also makes the *_insert_request strategies much easier to follow,
imo.