Reduce the locking coverage of the oft-used j_list_lock: the per-bh
jbd_lock_bh_state() gives us sufficient locking of buffer_head and
journal_head internals.

From: Hugh Dickins <hugh@veritas.com>

The earlier changes introducing PageAnon left truncated pages mapped into
nonlinear vmas unswappable.  Once we go to object-based rmap, it's
impossible to find where file page is mapped once page->mapping cleared:
switching them to anonymous is odd, and breaks strict commit accounting.

So now handle truncation of nonlinear vmas correctly.  And factor in
Daniel's cluster filesystem needs while we're there: when invalidating
local cache, we do want to unmap shared pages from all mms, but we do not
want to discard private COWed modifications of those pages (which
truncation discards to satisfy the SIGBUS semantics demanded by specs).

Drew from Daniel's patch (LKML 2 Mar 04), but didn't always follow it;
fewer name changes, but still some - "unmap" rather than "invalidate".
zap_page_range is not exported, safe to give it and all the too-many layers
an extra zap_details arg, in normal cases just NULL.

Given details, zap_pte_range checks page mapping or index to skip anon or
untruncated pages.  I didn't realize before implementing, that in nonlinear
case, it should set a file pte when truncating - otherwise linear pages
might appear in place of SIGBUS.  I suspect this implies that ->populate
functions ought to set file ptes beyond EOF instead of failing, but haven't
changed them as yet.

To avoid making yet another copy of that ugly linear pgidx test, added
inline function linear_page_index (to pagemap.h to get PAGE_CACHE_SIZE,
though as usual things don't really work if it differs from PAGE_SIZE). 
Ooh, I thought I'd removed ___add_to_page_cache last time, do so now.

unmap_page_range static, shift its hugepage check up into sole caller
unmap_vmas.  Killed "killme" debug from unmap_vmas, not seen it trigger.
unmap_mapping_range is exported without restriction: I'm one of those who
believe it should be generally available.  But I'm wrongly placed to decide
that, probably just sob quietly to myself if _GPL added later.

From: Hugh Dickins <hugh@veritas.com>

Good example of "swapper_space considered harmful": swap_unplug_io_fn was
originally designed for calling via swapper_space.backing_dev_info; but
that way it loses track of which device is to be unplugged, so had to
unplug all swap devices.  But now sync_page tests SwapCache anyway, can
call swap_unplug_io_fn with page, which leads direct to the device.

Reverted -mc4's CONFIG_SWAP=n fix, just add another NOTHING for it.
Reverted -mc3's editorial adjustments to swap_backing_dev_info and
swapper_space initializations: they document the few fields which are
actually used now, as comment above them says (sound of slapped wrist).

From: Hugh Dickins <hugh@veritas.com>

One of the callers of flush_dcache_page is do_generic_mapping_read, where
file is read without i_sem and without page lock: concurrent truncation may
at any moment remove page from cache, NULLing ->mapping, making
flush_dcache_page liable to oops.  Put result of page_mapping in a local
variable and apply mapping_mapped to that (if we were to check for NULL
within mapping_mapped, it's unclear whether to say yes or no).

parisc and arm do have other locking unsafety in their i_mmap(_shared)
searching, but that's a larger issue to be dealt with down the line.

From: Anton Blanchard <anton@samba.org>

Oprofilefs cant handle > 99 cpus. This should fix it.

From: Rusty Russell <rusty@rustcorp.com.au>

# lsmod
Module                  Size  Used by
1                      26060  6
#

The compiler #define's unix to 1: we use -DKBUILD_MODNAME=unix.  We used to
#undef unix at the top of af_unix.c, but now the name is inserted by
modpost, that doesn't help.

#undef unix in modpost.c's generated C file.

From: Benjamin Herrenschmidt <benh@kernel.crashing.org>

My RTAS locking fixes incorrectly added a spinlock around the function used
to stop a CPU, that function never returns, thus the lock becomes stale.
The correct fix is to disable interrupts instead (the RTAS params beeing
per-CPU, this should be safe enough)

But obviously only if we're not passing in any offset pointer.

This is how 2.4.x worked, and vsftpd relies on it.

Bug reported by Chris < chris@scary.beasts.org>

into ppc970.osdl.org:/home/torvalds/v2.6/linux

It occurred to me that if vma and new_vma are one and the same, then
vma_relink_file will not do a good job of linking it after itself - in
that pretty unlikely case when move_page_tables fails.

And more generally, whenever copy_vma's vma_merge succeeds, we have no
guarantee that old vma comes before new_vma in the i_mmap lists, as we
need to satisfy Rajesh's point: that ordering is only guaranteed in the
newly allocated case.

We have to abandon the ordering method when/if we move from lists to
prio_trees, so this patch switches to the less glamorous use of
i_shared_sem exclusion, as in my prio_tree mremap.

The field in question is
  a) unused
  b) damn next to impossible to use correctly, due to struct super_block
     lifetime and locking rules.

into ppc970.osdl.org:/home/torvalds/v2.6/linux

into ppc970.osdl.org:/home/torvalds/v2.6/linux

Update serial to use new module parameters rather than
MODULE_PARM.

into ppc970.osdl.org:/home/torvalds/v2.6/linux

This adds detailed documentation concerning how we map the Linux
page table structure onto the hardware tables on ARM.  In addition,
it also adds documentation describing how we emulate the "dirty"
and "young" or "accessed" page table bits.

This should be of interest to Linux MM developers.

Patch from: Pavel Roskin

As it turns out, mixing MODULE_PARM and module_param in one module is
wrong.  The parameters specified in module_param are ignored.  I've just
posted a patch to LKML that will detect this condition and warn about it.

The new debugging code used the new-style module_param, which means that
all instances of MODULE_PARM should be converted.  The attached patch does
that.

An additional bonus is that module_param_array provides the number of
array elements.  This allowed me to change tcic.c and i82365.c to use
this number for IRQ list.  This change was tested with i82365.  If
"irq_list" is not specified, irq_list_count is 0.

I set all permissions to 0444 to be safe.  I think we have no secrets
from the users regarding those parameters.  If some parameters can be
changed safely at the runtime, the permissions could be changed to 0644.
I didn't examine how safe (and how useful) it would be, so it's 0444 for
now.

From: William Lee Irwin III <wli@holomorphy.com>

rmk mentioned that ARM was borked as the relation, assumed by generic rmap,
PTRS_PER_PTE*sizeof(pte_t) == PAGE_SIZE, fails to hold.  The following
patch, developed jointly with him (or depending on POV, by him with me
acting as codemonkey), is reported to resolve the issue.

Specifically, while ARM dedicates an entire PAGE_SIZE -sized block of
memory to each PTE table, the PTE table itself only spans half that, the
remainder being dedicated to hardware-interpreted structures.  As the
hardware structure must be contiguous, wider ptes can't be used.  So the
core-visible PTE table only spans PAGE_SIZE/2 bytes, violating the
assumption.  This corrects masking and scaling done in ptep_to_address().

From: Dave Jones <davej@redhat.com>

From: Manfred Spraul <manfred@colorfullife.com>

Any user can delete any entries in a mqueue mounted filesystem.  The attached
patch prevents that.

- remove the writable test from mq_unlink.

- set the sticky bit in the root inode.  This affects both mq_unlink and
  sys_unlink: only the owner (and root) should be allowed to remove queues.

From: David Gibson <david@gibson.dropbear.id.au>

Some versions of follow_huge_addr() and follow_huge_pmd() are doing a
get_page() on the target page.  They shouldn't: follow_page() returns an
unpinned page and it is the caller's responsibility to pin the page (if
desired) before dropping page_table_lock.

From: David Gibson <david@gibson.dropbear.id.au>

Trivial cleanup to flush_hash_hugepage() in the ppc64 hugepage code.

From: Geert Uytterhoeven <geert@linux-m68k.org>

While compiling drivers/char/ipmi/ipmi_si_intf.c in 2.6.6-rc1 on m68k, I
noticed a missing include (needed for disable_irq_nosync() and enable_irq())

From: "Randy.Dunlap" <rddunlap@osdl.org>

floppy98.c (along with other PC-9800 files) has not been updated lately.  It
won't build currently (2.6.5).

This patch makes floppy98 build cleanly.

From: Chris Mason <mason@suse.com>

Get rid of the last sleep_on in the reiserfs code

From: Chris Mason <mason@suse.com>

Updates the reiserfs-logging improvements to use schedule_timeout instead of
yield when letting the transaction grow a little before forcing a commit for
fsync/O_SYNC/O_DIRECT.

Also, when one process forces a transaction to end and plans on doing the
commit (like fsync), it sets a flag on the transaction so the journal code
knows not to bother kicking the journal work queue.

queue_delayed_work is used so that if we get a bunch of tiny transactions
ended quickly, we aren't constantly kicking the work queue.

These significantly improve reiserfs performance during fsync heavy
workloads.

From: Bart Samwel <bart@samwel.tk>

Add support for value 0 to the commit option of reiserfs.  Means "restore
to the default value".  For the maximum commit age, this default value is
normally read from the journal; this patch adds an extra variable to cache
the default value for the maximum commit age.

From: David Gibson <david@gibson.dropbear.id.au>

This is a small cleanup to the PPC64 hugepage code.  It removes an
unhelpful function, removing some studlyCaps in the process.  It was
originally this way to match the normal page path, but that has all been
rewritten since.

From: Jakub Jelinek <jakub@redhat.com>

The first change removes just a useless put_user (si_int and si_ptr are
part of the same union, si_ptr is on all arches covering whole union), the
rest is fixes for signal handling of SI_MESGQ.

From: Jeff Garzik <jgarzik@pobox.com>

It was debug code, no longer required.

From: Bjorn Helgaas <bjorn.helgaas@hp.com>

This consolidates the PCI MSI configuration into drivers/pci/Kconfig,
removing it from the i386, x86_64, and ia64 Kconfig.

It also changes the default for ia64 from "y" to "n".  The default on i386
is "n" already, and I'm not sure why ia64 should be different.

From: Jeff Garzik <jgarzik@pobox.com>

Nobody ever checks the return value of submit_bh(), and submit_bh() is the
only caller that checks the submit_bio() return value.

This changes the kernel I/O submission path -- a fast path -- so this
cleanup is also a microoptimization.

From: NeilBrown <neilb@cse.unsw.edu.au>

From: "J. Bruce Fields" <bfields@fieldses.org>

From: Andros: Implement server-side reboot recovery (server now handles
open and lock reclaims).  Not completely to spec: we don't yet store the
state in stable storage that would be required to recover correctly in
certain situations.

From: NeilBrown <neilb@cse.unsw.edu.au>

The credentials (uid/gid) of a process are set when a filehandle is
verified.  Nfsv4 allows requests without an explicit filehandle (instead,
an implicit 'root' filehandle) so we much make sure the credentials are set
for these requests too.

From: "J. Bruce Fields" <bfields@fieldses.org>

From: Andros: added a call to nfsd_setuser in nfsd4_putrootfh so that nfsd
runs as the rpc->cred user.

From: NeilBrown <neilb@cse.unsw.edu.au>

From: "J. Bruce Fields" <bfields@fieldses.org>

From: Andros: Hold state_lock longer so the stateowner doesn't diseappear
out from under us before we get the chance to encode the replay.  Don't
attempt to save replay if we failed to find a stateowner.

From: NeilBrown <neilb@cse.unsw.edu.au>

From: "J. Bruce Fields" <bfields@fieldses.org>

From: Andros: locku replies should be saved for possible replay as well.

From: NeilBrown <neilb@cse.unsw.edu.au>

From: "J. Bruce Fields" <bfields@fieldses.org>

From: Andros: Idea is to keep around a list of openowners recently released
by closes, and make sure they stay around long enough so that replays still
work.

From: NeilBrown <neilb@cse.unsw.edu.au>

From: "J. Bruce Fields" <bfields@fieldses.org>

Error return when the client supplies a bad service should be badcred.

From: NeilBrown <neilb@cse.unsw.edu.au>

From: "J. Bruce Fields" <bfields@fieldses.org>

Fix out-of-spec errors in nfs4 readdir.  Add checks for bad cookie values.

(plus compile fix from akpm)