Add sys_wait4 to the list of exported functions.

Warning fixes: remove an unused variable and make bitops complain if the
pointer isn't of type long. Make 31 bit BUG() emit 4 0-bytes instead of 2.
This improves the readability of the listing.

Make some functions and variables static.

Remove last remaining file of the old tape driver.

Fix return value of __put_user_asm_8.

Start of chsc interface cleanup. Fix for a race condition in do_IRQ.
Fix device reference counting.

sys_restart_syscall for nanosleep restarting.

Makefile changes by Sam Ravnborg. Summary of changes:
o Added FORCE prerequisite in boot/Makefile
o Do not use shorthand targets when calling the boot/Makefile
o No longer use BOOT_IMAGE, not needed now
o Use kbuild clean infrastructure when cleaning up in boot
o Offset generation shrinked with one rule
o removed inclusion of Rules.make in all Makefiles
o no longer use the descend macro, use $(Q)$(MAKE) as replacement

hch moved around to work for SGI..

This patch moves the Kconfig entries for CPUfreq from "Processor type and
features" to "Power management options".

This patch moves some basic per-CPU static information (minimum frequency,
maximum frequency and maximum transition latency) into a struct
cpufreq_cpuinfo. This offers a much cleaner struct cpufreq_driver and
struct cpufreq_policy.

Kill unused variable and simplify assembly portion a bit...

gcc3.2 is a bit more pedantic...

sr_ioctl.c uses virt_to_phys, which is defined in asm/io.h.
On x86, this accidentally works, due to other indirect includes,
but on Alpha results in a link error.

This fixes one more threaded-coredumps detail reported by the glibc
people: all threads taken down by the coredump code should report the
proper exit code.  We can do this rather easily via the group_exit
mechanism.  'Other' threads used to report SIGKILL, which was highly
confusing as the shell often displayed the 'Killed' message instead of a
'Segmentation fault' message.

Another missing bit was the 0x80 bit set in the exit status for all
threads, if the coredump was successful.  (it's safe to set this bit in
->sig->group_exit_code in an unlocked way because all threads are
artificially descheduled by the coredump code.)

Moves console_loglevel & friends to an array, as sysctl expects.

Makefiles no longer need to include Rules.make, which is currently an
empty file.  This patch removes it from the remaining Makefiles, and
removes the empty Rules.make file.

Makefiles no longer need to include Rules.make, which is currently an
empty file.  This patch removes it from the drivers tree Makefiles.

Makefiles no longer need to include Rules.make, which is currently an
empty file.  This patch removes it from the arch tree Makefiles.

This contains the following changes for the SCSI tape driver in 2.5.51:
- fix module bugs that prevent finding any devices
- allow opening a device with O_NONBLOCK | O_RDWR even if the tape in drive
  is write protected

Remove the unused vm_area_struct.vm_raend.

If someone wants to tune per-VMA readaround then they can alter
vma->vm_file->f_ra.ra_pages.

It is missing a brelse() on an error path.

Fetch the next cacheline as we're counting up the fields in this one.

The optimisation for synchronous mounts was only correct for S_ISREG
files.  Directories do not pass through generic_osync_inode() and we
still need to synchronously write out their indirect blocks.

In PAE mode there is a 4-byte gap and they're not aligning correctly.

From Hugh.

Be consistent in deciding when we are below the zone allocation
thresholds.

From Hugh.

Be more explicit in the "can we sleep" test.  It doesn't change
anything unless someone is performing __GFP_IO && !__GFP_WAIT
allocations, which is nonsensical.

A little cleanup suggested by Chris Mason or Al Viro.

Quite a number of codepaths are testing whether a superblock has a
non-null ->s_op pointer.  We can remove all those by making sure that
all superblocks have a valid ->s_op.

madvise_willneed() currently has a very strange check on how much readahead
it is prepared to do.

  It is based on the user's rss limit.  But this is usually enormous, and
  the user isn't necessarily going to map all that memory at the same time
  anyway.

  And the logic is wrong - it is comparing rss (which is in bytes) with
  `end - start', which is in pages.

  And it returns -EIO on error, which is not mentioned in the Open Group
  spec and doesn't make sense.


This patch takes it all out and applies the same upper limit as is used in
sys_readahead() - half the inactive list.

This ad-hoc assertion is no longer true.  If all zones are in the `all
unreclaimable' state it can trigger.  When testing with a tiny amount
of physical memory.

readahead allocates all the pages before starting I/O.  Potentially bad
if someone is performing huge reads with madvise or sys_readahead().

So the patch just busts that up into two-megabyte units.

generic_file_write()'s rlimit checks are preventing writes to large
offsets into blockdevs:

# ulimit -f 10000
# dd if=/dev/zero of=/dev/sde5 bs=1k count=1 seek=1000000
zsh: file size limit exceeded

So don't apply that check if it's a blockdev.

The patch also caches the S_ISBLK result in a local.

From Andreas Dilger.

Additional sanity checks in the ext2 and ext3 block allocators: if
someone tries to free a negative number of blocks, detect and handle
that rather than wrecking the fs.

Patch from "Juan M. de la Torre" <jmtorre@gmx.net>

If the requested align is PAGE_SIZE, it is impossible to merge with the
previous allocation request, because the allocated area must begin in a
page boundary.

Prevents children from inheriting mlockall(MCL_FUTURE).
Standards-friendly, and 2.4 has it.

current->flags:PF_SYNC was a hack I added because I didn't want to
change all ->writepage implementations.

It's foul.  And it means that if someone happens to run direct page
reclaim within the context of (say) sys_sync, the writepage invokations
from the VM will be treated as "data integrity" operations, not "memory
cleansing" operations, which would cause latency.

So the patch removes PF_SYNC and adds an extra arg to a_ops->writepage.
 It is the `writeback_control' structure which contains the full context
information about why writepage was called.

The initial version of this patch just passed in a bare `int sync', but
the XFS team need more info so they can perform writearound from within
page reclaim.

The patch also adds writeback_control.for_reclaim, so writepage
implementations can inspect that to work out the call context rather
than peeking at current->flags:PF_MEMALLOC.

Under rare conditions (filesystem corruption, really) it is possible
for ext3_dirty_inode() to require _two_ blocks for the transaction: one
for the inode and one to update the superblock - to set
EXT3_FEATURE_RO_COMPAT_LARGE_FILE.  This causes the filesystem to go
BUG.

So reserve an additional block for that eventuality.

Fixes the problem identified by Miles Bader on extremely small zones:
calling hash_long with `bits = 0' is treated as `bits = 32'.

So don't permit the zone to have a one-slot waitqueue hashtable.

This allows us to control the aggressiveness of the lower-zone defense
algorithm.  The `incremental min'.  For workloads which are using a
serious amount of mlocked memory, a few megabytes is not enough.

So the `lower_zone_protection' tunable allows the administrator to
increase the amount of protection which lower zones receive against
allocations which _could_ use higher zones.

The default value of lower_zone_protection is zero, giving unchanged
behaviour.  We should not normally make large amounts of memory
unavailable for pagecache just in case someone mlocks many hundreds of
megabytes.