More timer micropatches.

into redhat.com:/home/jgarzik/repo/net-drivers-2.5

Other locks already cover the areas in question, and additionally
this lock was held in areas where it should not have been, triggering
error messages in 2.5.x.

into redhat.com:/home/jgarzik/repo/net-drivers-2.5

Results of a quick pass through everything under drivers/.  We're
mostly OK in there.  I will have missed some.

The patches which I needed to avoid the warnings with my build.

Add some infrastructure for statically initialising timers,
use that in workqueues.

If two CPUs run mod_timer against the same not-pending timer then they
have no locking relationship.  They can both see the timer as
not-pending and they both add the timer to their cpu-local list.  The
CPU which gets there second corrupts the first CPU's lists.

This was causing Dave Hansen's 8-way to oops after a couple of minutes
of specweb testing.

I believe that to fix this we need locking which is associated with the
timer itself.  The easy fix is hashed spinlocking based on the timer's
address.  The hard fix is a lock inside the timer itself.

It is hard because init_timer() becomes compulsory, to initialise that
spinlock.  An unknown number of code paths in the kernel just wipe the
timer to all-zeroes and start using it.

I chose the hard way - it is cleaner and more idiomatic.  The patch
also adds a "magic number" to the timer so we can detect when a timer
was not correctly initialised.  A warning and stack backtrace is
generated and the timer is fixed up.  After 16 such warnings the
warning mechanism shuts itself up until a reboot.

It took six patches to my kernel to stop the warnings from coming out.
The uninitialised timers are extremely easy to find and fix.  But it
will take some time to weed them all out.  Maybe we should go for
the hashed locking...

Note that the new timer->lock means that we can clean up some awkward
"oh we raced, let's try again" code in timer.c.  But to do that we'd
also need to take timer->lock in the commonly-called del_timer(), so I
left it as-is.

The lock is not needed in add_timer() because concurrent
add_timer()/add_timer() and concurrent add_timer()/mod_timer() are
illegal.

Final act, from Manfred:

The attached patch removes 'event' entirely from the kernel: it's not
used anymore.

All event users [vfat dentry revalidation; ext2/3 inode generation;
readdir() file position revalidation in several filesystems] were
converted to local counters.

Patch from Manfred Spraul

Several filesystems compare f_version and i_version to validate
directory positions in readdir(): The directory position is revalidated
if i_version is not equal f_version.  Operations that could invalidate
the cached position set i_version or f_version to '++event', event is a
global variable.  Global uniqueness is not needed, 'i_version++' and
'f_version=0' is sufficient to guarantee that the next readdir() will
revalidate the directory position, and that avoids the need for an ugly
global variable.

The attached patch converts all filesystems except ext2, which was
converted with a seperate patch.

Patch from Manfred Spraul

Use a local counter instead of the global 'event' variable for the
readdir() optimization.

Depends on patch-event-II

Background:
  The only user of i_version and f_version in ext2 is
  ext2_readdir(). As an optimization, ext2 performs the
  validation of the start position for readdir() only if
        flip->f_version != inode->i_version.
  If there was no llseek and no directory change since the
  last readdir() call, then f_pos can be trusted.
  f_version is set to 0 in get_empty_flip and during llseek.
  Right now, i_version set to ++event during ext2_read_inode
  and commit_chunk, i.e. at inode creation and if a directory
  is changed.
  Initializing i_version to 1, and updating with i_version++
  achieves the same effect, without the need of a global variable.
  Global uniqueness is not required, there are no other uses
  of [if]_version in ext2.

Change relative to the patch you have right now:
i_version is initialized to 1 instead of 0. For ext2 it's doesn't
matter [there is always a valid 'len' value at the beginning of a
directory data block], but it's cleaner.

Patch from Manfred Spraul

f_version and i_version are used by filesystems to check if it can
reuse the f_pos position across readdir calls without validation.

Right now f_version and i_version are modified by
    f_version = ++event;
    i_version = ++event;
    if (f_version != i_version) goto revalidate
and event is a global, exported variable.

But that's not needed,
    f_version  = 0;
    i_version++;
    if (f_version != i_version) goto revalidate
works too, without the ugly 'event' variable.

I got an ok from viro, and I had notified the fs maintainers, no
complaints either

- block_dev.c, block_llseek updates f_version to '++event'.
   grep showed that no device driver uses f_version, this is dead
   code copied from the default llseek implementation.

- the llseek implementations and get_empty_flip set f_version
   to '++event'
   This is not dead code, but
            filp->f_version = 0
   achieves the same effect:
   f_version is used by the readdir() implementation of several
   filesystems to skip the revalidation of f_pos at the beginning
   of a readdir call: If llseek was not called and the filesystem
   did not change since the last readdir call, then the value in
   f_pos can be trusted.
   The implementation (for example in ext2) is
     inode->i_version = ++event;
   in all operations that change a directory
   At the beginning of file_operation->readdir():
     if(inode->i_version != flip->f_version)
                revalidate();
     filp->f_version = inode->i_version;
   There are other users of f_version, but none of them use the
   default llseek implementation (e.g. fs/pipe.c)

 NinjaSCSI-3R PCMCIA SCSI host adapter driver updated for the latest
kernel tree.

Intermezzo has some strange, broken code trying to deal with extended
attributes and and ACLs.  Fortunately the xattr code is hidden under
a config option that's never set, but the ACL code is enabled by
CONFIG_POSIX_ACL that's se by ext2/ext3 and jfs now.  Change it to
#if 0 to get intermezzo compiling again.

into home.transmeta.com:/home/torvalds/v2.5/linux

  Update sbp2scsi_biosparam() declaration to match sbp2.c
sbp2.c:
  C s/capacy/capacity/

into home.transmeta.com:/home/torvalds/v2.5/linux

Grrh, don't do last minute changes without retesting.

Adapt arch/alpha as well, other archs need to
o add LDFLAGS_BLOB to arch/$(ARCH)/Makefile
o add .init.ramfs to arch/$(ARCH)/vmlinux.lds.S

See arch/i386/{Makefile,vmlinux.lds.S} for guidance ;)

- Split out from bluesmoke.c into per-vendor files (Me)
  (If we were that way inclined, we could even make the
   per-vendor bits CONFIG_ options, but thats probably overkill)
- Fixes Kconfig markup. (Roman Zippel)
- P4 can use non-fatal background checker too. (Venkatesh Pallipadi)
- Don't clear MCA status info in case of non-recoverable if
  OS has failed in logging those, BIOS can still ahve a look at
  that info. (Venkatesh)
- We can init bank 0 on P4 (Zwane Mwaikambo)
- Compile away to nothing if CONFIG_X86_MCE=n
- Various other cleaning (Me)

From 2.4

This is used by the following Cyrix patch to handle buggy or spec tight
PIT stuff

Since we don't have mandatory mmap lock files we can lose this chunk