Change the code ordering so that hibernation_ops->prepare() is called after
device_suspend().  This is needed so that we don't violate the ACPI
specification, which states that the _PTS and _GTS system-control methods,
executed from acpi_sleep_prepare(), ought to be called after devices have been
put in low power states.

The "Finish" label in hibernation_restore() is moved, because device_suspend()
resumes devices if the suspending of them fails and the restore code ordering
should reflect the hibernation code ordering.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NPavel Machek <pavel@ucw.cz>
Cc: Nigel Cunningham <nigel@nigel.suspend2.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

At least on some machines it is necessary to prepare the ACPI firmware for the
restoration of the system memory state from the hibernation image if the
"platform" mode of hibernation has been used.  Namely, in that cases we need
to disable the GPEs before replacing the "boot" kernel with the "frozen"
kernel (cf.  http://bugzilla.kernel.org/show_bug.cgi?id=7887).  After the
restore they will be re-enabled by hibernation_ops->finish(), but if the
restore fails, they have to be re-enabled by the restore code explicitly.

For this purpose we can introduce two additional hibernation operations,
called pre_restore() and restore_cleanup() and call them from the restore code
path.  Still, they should be called if the "platform" mode of hibernation has
been used, so we need to pass the information about the hibernation mode from
the "frozen" kernel to the "boot" kernel in the image header.

Apparently, we can't drop the disabling of GPEs before the restore because of
Bug #7887 .   We also can't do it unconditionally, because the GPEs wouldn't
have been enabled after a successful restore if the suspend had been done in
the 'shutdown' or 'reboot' mode.

In principle we could (and probably should) unconditionally disable the GPEs
before each snapshot creation *and* before the restore, but then we'd have to
unconditionally enable them after the snapshot creation as well as after the
restore (or restore failure)   Still, for this purpose we'd need to modify
acpi_enter_sleep_state_prep() and acpi_leave_sleep_state() and we'd have to
introduce some mechanism synchronizing the disablind/enabling of the GPEs with
the device drivers' .suspend()/.resume() routines and with
disable_/enable_nonboot_cpus().   However, this would have affected the
suspend (ie.  s2ram) code as well as the hibernation, which I'd like to avoid
in this patch series.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Cc: Nigel Cunningham <nigel@nigel.suspend2.net>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently, much of the code in kernel/power/disk.c is duplicated in
kernel/power/user.c , mainly for historical reasons.  By eliminating this code
duplication we can reduce the size of user.c quite substantially and remove
the maintenance difficulty resulting from it.

[bunk@stusta.de: kernel/power/disk.c: make code static]
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NPavel Machek <pavel@ucw.cz>
Cc: Nigel Cunningham <nigel@nigel.suspend2.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In the face of the recent change of suspend code ordering (cf.
http://marc.info/?l=linux-acpi&m=117938245931603&w=2) we should also modify
the code ordering in swsusp so that hibernation_ops->prepare() is executed
after device_suspend().

However, for this purpose it seems reasonable to eliminate the code
duplication between kernel/power/disk.c and kernel/power/user.c first.  By
eliminating it we can reduce the size of user.c quite substantially and remove
the maintenance difficulty with making essentially the same changes in two
different places.

Moreover, we should also remove the calls to "platform" functions from the
restore code path, since it doesn't carry out any power transition of the
system, but we generally need to disable the GPEs before the restore if the
'platform' hibernation mode has been used.  To do this, we can introduce two
new hibernation_ops to be used in the restore code.

This patch:

Make the code hibernation code in kernel/power/user.c be functionally
equivalent to the corresponding code in kernel/power/disk.c , as it should be.

The calls to the platform functions removed by this patch are incorrect.  They
should be replaced with some other "platform" invocations that will be
introduced in one of the subsequent patches.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NPavel Machek <pavel@ucw.cz>
Cc: Nigel Cunningham <nigel@nigel.suspend2.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In order to enable things like PM_TRACE, you're required to enable
PM_DEBUG, which sends a large spew of messages on boot, and often times can
overflow dmesg buffer.

Create new PM_VERBOSE and shift that to be the option that enables
drivers/base/power's messages.
Signed-off-by: NBen Collins <bcollins@ubuntu.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

To see which tasks are stuck where.

Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

page_mkclean() doesn't re-protect ptes for non-linear mappings, so a later
re-dirty through such a mapping will not generate a fault, PG_dirty will
not reflect the dirty state and the dirty count will be skewed.  This
implies that msync() is also currently broken for nonlinear mappings.

The easiest solution is to emulate remap_file_pages on non-linear mappings
with simple mmap() for non ram-backed filesystems.  Applications continue
to work (albeit slower), as long as the number of remappings remain below
the maximum vma count.

However all currently known real uses of non-linear mappings are for ram
backed filesystems, which this patch doesn't affect.
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

alloc_zeroed_user_highpage() has no in-tree users and it is not exported.
As it is not exported, it can simply be removed.
Signed-off-by: NMel Gorman <mel@csn.ul.ie>
Acked-by: NAndy Whitcroft <apw@shadowen.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix msync data loss and (less importantly) dirty page accounting
inaccuracies due to the race remaining in clear_page_dirty_for_io().

The deleted comment explains what the race was, and the added comments
explain how it is fixed.
Signed-off-by: NNick Piggin <npiggin@suse.de>
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch completes Linus's wish that the fault return codes be made into
bit flags, which I agree makes everything nicer.  This requires requires
all handle_mm_fault callers to be modified (possibly the modifications
should go further and do things like fault accounting in handle_mm_fault --
however that would be for another patch).

[akpm@linux-foundation.org: fix alpha build]
[akpm@linux-foundation.org: fix s390 build]
[akpm@linux-foundation.org: fix sparc build]
[akpm@linux-foundation.org: fix sparc64 build]
[akpm@linux-foundation.org: fix ia64 build]
Signed-off-by: NNick Piggin <npiggin@suse.de>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ian Molton <spyro@f2s.com>
Cc: Bryan Wu <bryan.wu@analog.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Greg Ungerer <gerg@uclinux.org>
Cc: Matthew Wilcox <willy@debian.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Kazumoto Kojima <kkojima@rr.iij4u.or.jp>
Cc: Richard Curnow <rc@rc0.org.uk>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Miles Bader <uclinux-v850@lsi.nec.co.jp>
Cc: Chris Zankel <chris@zankel.net>
Acked-by: NKyle McMartin <kyle@mcmartin.ca>
Acked-by: NHaavard Skinnemoen <hskinnemoen@atmel.com>
Acked-by: NRalf Baechle <ralf@linux-mips.org>
Acked-by: NAndi Kleen <ak@muc.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
[ Still apparently needs some ARM and PPC loving - Linus ]
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Change ->fault prototype.  We now return an int, which contains
VM_FAULT_xxx code in the low byte, and FAULT_RET_xxx code in the next byte.
 FAULT_RET_ code tells the VM whether a page was found, whether it has been
locked, and potentially other things.  This is not quite the way he wanted
it yet, but that's changed in the next patch (which requires changes to
arch code).

This means we no longer set VM_CAN_INVALIDATE in the vma in order to say
that a page is locked which requires filemap_nopage to go away (because we
can no longer remain backward compatible without that flag), but we were
going to do that anyway.

struct fault_data is renamed to struct vm_fault as Linus asked. address
is now a void __user * that we should firmly encourage drivers not to use
without really good reason.

The page is now returned via a page pointer in the vm_fault struct.
Signed-off-by: NNick Piggin <npiggin@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There seems to be very little documentation about this callback in general.
The locking in particular is a bit tricky, so it's worth having this in
writing.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

__do_fault() was calling ->page_mkwrite() with the page lock held, which
violates the locking rules for that callback.  Release and retake the page
lock around the callback to avoid deadlocking file systems which manually
take it.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Nonlinear mappings are (AFAIKS) simply a virtual memory concept that encodes
the virtual address -> file offset differently from linear mappings.

->populate is a layering violation because the filesystem/pagecache code
should need to know anything about the virtual memory mapping.  The hitch here
is that the ->nopage handler didn't pass down enough information (ie.  pgoff).
 But it is more logical to pass pgoff rather than have the ->nopage function
calculate it itself anyway (because that's a similar layering violation).

Having the populate handler install the pte itself is likewise a nasty thing
to be doing.

This patch introduces a new fault handler that replaces ->nopage and
->populate and (later) ->nopfn.  Most of the old mechanism is still in place
so there is a lot of duplication and nice cleanups that can be removed if
everyone switches over.

The rationale for doing this in the first place is that nonlinear mappings are
subject to the pagefault vs invalidate/truncate race too, and it seemed stupid
to duplicate the synchronisation logic rather than just consolidate the two.

After this patch, MAP_NONBLOCK no longer sets up ptes for pages present in
pagecache.  Seems like a fringe functionality anyway.

NOPAGE_REFAULT is removed.  This should be implemented with ->fault, and no
users have hit mainline yet.

[akpm@linux-foundation.org: cleanup]
[randy.dunlap@oracle.com: doc. fixes for readahead]
[akpm@linux-foundation.org: build fix]
Signed-off-by: NNick Piggin <npiggin@suse.de>
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix the race between invalidate_inode_pages and do_no_page.

Andrea Arcangeli identified a subtle race between invalidation of pages from
pagecache with userspace mappings, and do_no_page.

The issue is that invalidation has to shoot down all mappings to the page,
before it can be discarded from the pagecache.  Between shooting down ptes to
a particular page, and actually dropping the struct page from the pagecache,
do_no_page from any process might fault on that page and establish a new
mapping to the page just before it gets discarded from the pagecache.

The most common case where such invalidation is used is in file truncation.
This case was catered for by doing a sort of open-coded seqlock between the
file's i_size, and its truncate_count.

Truncation will decrease i_size, then increment truncate_count before
unmapping userspace pages; do_no_page will read truncate_count, then find the
page if it is within i_size, and then check truncate_count under the page
table lock and back out and retry if it had subsequently been changed (ptl
will serialise against unmapping, and ensure a potentially updated
truncate_count is actually visible).

Complexity and documentation issues aside, the locking protocol fails in the
case where we would like to invalidate pagecache inside i_size.  do_no_page
can come in anytime and filemap_nopage is not aware of the invalidation in
progress (as it is when it is outside i_size).  The end result is that
dangling (->mapping == NULL) pages that appear to be from a particular file
may be mapped into userspace with nonsense data.  Valid mappings to the same
place will see a different page.

Andrea implemented two working fixes, one using a real seqlock, another using
a page->flags bit.  He also proposed using the page lock in do_no_page, but
that was initially considered too heavyweight.  However, it is not a global or
per-file lock, and the page cacheline is modified in do_no_page to increment
_count and _mapcount anyway, so a further modification should not be a large
performance hit.  Scalability is not an issue.

This patch implements this latter approach.  ->nopage implementations return
with the page locked if it is possible for their underlying file to be
invalidated (in that case, they must set a special vm_flags bit to indicate
so).  do_no_page only unlocks the page after setting up the mapping
completely.  invalidation is excluded because it holds the page lock during
invalidation of each page (and ensures that the page is not mapped while
holding the lock).

This also allows significant simplifications in do_no_page, because we have
the page locked in the right place in the pagecache from the start.
Signed-off-by: NNick Piggin <npiggin@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* 'isdn-fix' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/misc-2.6:
  ISDN HiSax: uninitialized return in hisax_cs_setup

* 'upstream-linus' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/netdev-2.6:
  eHEA: Fix bonding support
  Blackfin ethernet driver: on chip ethernet MAC controller driver
  fix wrong argument of tc35815_read_plat_dev_addr()
  ARM/ETHER3: Handle multicast frames.
  SAA9730: Handle multicast frames.
  NI5010: Handle multicast frames.
  NS83820: Handle multicast frames.
  Fix RGMII-ID handling in gianfar
  Fix Vitesse RGMII-ID support
  Add phy-connection-type to gianfar nodes
  Fix Vitesse 824x PHY interrupt acking
  [PATCH] zd1211rw: Add ID for Siemens Gigaset USB Stick 54
  [PATCH] zd1211rw: Add ID for Planex GW-US54GXS
  [PATCH] Update version ipw2200 stamp to 1.2.2
  [PATCH] ipw2200: Fix ipw_isr() comments error on shared IRQ
  [PATCH] Fix ipw2200 set wrong power parameter causing firmware error
  [PATCH] ipw2100: Fix `iwpriv set_power` error
  [PATCH] softmac: Channel is listed twice in scan output

* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6: (24 commits)
  [CIFS] merge conflict in fs/cifs/export.c
  [CIFS] Allow disabling CIFS Unix Extensions as mount option
  [CIFS] More whitespace/formatting fixes (noticed by checkpatch)
  [CIFS] Typo in previous patch
  [CIFS] zero_user_page() conversions
  [CIFS] use simple_prepare_write to zero page data
  [CIFS] Fix build break - inet.h not included when experimental ifdef off
  [CIFS] Add support for new POSIX unlink
  [CIFS] whitespace/formatting fixes
  [CIFS] Fix oops in cifs_create when nfsd server exports cifs mount
  [CIFS] whitespace cleanup
  [CIFS] Fix packet signatures for NTLMv2 case
  [CIFS] more whitespace fixes
  [CIFS] more whitespace cleanup
  [CIFS] whitespace cleanup
  [CIFS] whitespace cleanup
  [CIFS] ipv6 support no longer experimental
  [CIFS] Mount should fail if server signing off but client mount option requires it
  [CIFS] whitespace fixes
  [CIFS] Fix sign mount option and sign proc config setting
  ...

* master.kernel.org:/pub/scm/linux/kernel/git/gregkh/docs-2.6:
  zh_CN/HOWTO: update URLs of git trees
  Chinese translation of Documentation/stable_api_nonsense.txt
  HOWTO: add Chinese translation of Documentation/HOWTO
  Documentation: add Japanese translated stable_api_nonsense.txt
  HOWTO: add Japanese translation of Documentation/HOWTO

* master.kernel.org:/pub/scm/linux/kernel/git/gregkh/driver-2.6:
  sysfs: cosmetic clean up on node creation failure paths
  sysfs: kill an extra put in sysfs_create_link() failure path
  Driver core: check return code of sysfs_create_link()
  HOWTO: Add the knwon_regression URI to the documentation
  dev_vdbg() documentation
  dev_vdbg(), available with -DVERBOSE_DEBUG
  sysfs: make sysfs_init_inode() static
  sysfs: fix sysfs root inode nlink accounting
  Documentation fix devres.txt: lib/iomap.c -> lib/devres.c
  sysfs: avoid kmem_cache_free(NULL)
  PM: remove deprecated dpm_runtime_* routines
  PM: Remove deprecated sysfs files
  Driver core: accept all valid action-strings in uevent-trigger
  debugfs: remove rmdir() non-empty complaint

* master.kernel.org:/pub/scm/linux/kernel/git/gregkh/uio-2.6:
  UIO: Hilscher CIF card driver
  UIO: Documentation
  UIO: Add the User IO core code

* 'for-linus' of git://linux-nfs.org/~bfields/linux:
  locks: fix vfs_test_lock() comment
  locks: make posix_test_lock() interface more consistent
  nfs: disable leases over NFS
  gfs2: stop giving out non-cluster-coherent leases
  locks: export setlease to filesystems
  locks: provide a file lease method enabling cluster-coherent leases
  locks: rename lease functions to reflect locks.c conventions
  locks: share more common lease code
  locks: clean up lease_alloc()
  locks: convert an -EINVAL return to a BUG
  leases: minor break_lease() comment clarification

* 'for-linus' of master.kernel.org:/pub/scm/linux/kernel/git/roland/infiniband: (29 commits)
  IB/mthca: Simplify use of size0 in work request posting
  IB/mthca: Factor out setting WQE UD segment entries
  IB/mthca: Factor out setting WQE remote address and atomic segment entries
  IB/mlx4: Factor out setting other WQE segments
  IB/mlx4: Factor out setting WQE data segment entries
  IB/mthca: Factor out setting WQE data segment entries
  IB/mlx4: Return receive queue sizes for userspace QPs from query QP
  IB/mlx4: Increase max outstanding RDMA reads as target
  RDMA/cma: Remove local write permission from QP access flags
  IB/mthca: Use uninitialized_var() for f0
  IB/cm: Make internal function cm_get_ack_delay() static
  IB/ipath: Remove ipath_get_user_pages_nocopy()
  IB/ipath: Make a few functions static
  mlx4_core: Reset device when internal error is detected
  IB/iser: Make a couple of functions static
  IB/mthca: Fix printk format used for firmware version in warning
  IB/mthca: Schedule MSI support for removal
  IB/ehca: Fix warnings issued by checkpatch.pl
  IB/ehca: Restructure ehca_set_pagebuf()
  IB/ehca: MR/MW structure refactoring
  ...

Conflicts:

	fs/cifs/export.c

Signed-off-by: NSteve French <sfrench@us.ibm.com>

Previously the only way to do this was to umount all mounts to that server,
turn off a proc setting (/proc/fs/cifs/LinuxExtensionsEnabled).

Fixes Samba bugzilla bug number: 4582 (and also 2008)
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Thanks to Doug Chapman for pointing out that the comment here is
inconsistent with the function prototype.
Signed-off-by: N"J. Bruce Fields" <bfields@citi.umich.edu>

Since posix_test_lock(), like fcntl() and ->lock(), indicates absence or
presence of a conflict lock by setting fl_type to, respectively, F_UNLCK
or something other than F_UNLCK, the return value is no longer needed.
Signed-off-by: N"J. Bruce Fields" <bfields@citi.umich.edu>

As Peter Staubach says elsewhere
(http://marc.info/?l=linux-kernel&m=118113649526444&w=2):

> The problem is that some file system such as NFSv2 and NFSv3 do
> not have sufficient support to be able to support leases correctly.
> In particular for these two file systems, there is no over the wire
> protocol support.
>
> Currently, these two file systems fail the fcntl(F_SETLEASE) call
> accidentally, due to a reference counting difference.  These file
> systems should fail more consciously, with a proper error to
> indicate that the call is invalid for them.

Define an nfs setlease method that just returns -EINVAL.

If someone can demonstrate a real need, perhaps we could reenable
them in the presence of the "nolock" mount option.
Signed-off-by: N"J. Bruce Fields" <bfields@citi.umich.edu>
Cc: Peter Staubach <staubach@redhat.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>

Since gfs2 can't prevent conflicting opens or leases on other nodes, we
probably shouldn't allow it to give out leases at all.

Put the newly defined lease operation into use in gfs2 by turning off
lease, unless we're using the "nolock' locking module (in which case all
locking is local anyway).
Signed-off-by: NMarc Eshel <eshel@almaden.ibm.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Cc: Steven Whitehouse <swhiteho@redhat.com>

Export setlease so it can used by filesystems to implement their lease
methods.
Signed-off-by: N"J. Bruce Fields" <bfields@citi.umich.edu>

Currently leases are only kept locally, so there's no way for a distributed
filesystem to enforce them against multiple clients.  We're particularly
interested in the case of nfsd exporting a cluster filesystem, in which
case nfsd needs cluster-coherent leases in order to implement delegations
correctly.

Also add some documentation.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

We've been using the convention that vfs_foo is the function that calls
a filesystem-specific foo method if it exists, or falls back on a
generic method if it doesn't; thus vfs_foo is what is called when some
other part of the kernel (normally lockd or nfsd) wants to get a lock,
whereas foo is what filesystems call to use the underlying local
functionality as part of their lock implementation.

So rename setlease to vfs_setlease (which will call a
filesystem-specific setlease after a later patch) and __setlease to
setlease.

Also, vfs_setlease need only be GPL-exported as long as it's only needed
by lockd and nfsd.
Signed-off-by: N"J. Bruce Fields" <bfields@citi.umich.edu>

Share more code between setlease (used by nfsd) and fcntl.

Also some minor cleanup.
Signed-off-by: N"J. Bruce Fields" <bfields@citi.umich.edu>
Acked-by: NChristoph Hellwig <hch@infradead.org>

Return the newly allocated structure as the return value instead of
using a struct ** parameter.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

There's no point trying to return an error in these cases, which all represent
bugs in the callers.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

clarify that break_lease() checks for presence of any lock, not just leases.
Signed-off-by: NDavid M. Richter <richterd@citi.umich.edu>
Signed-off-by: N"J. Bruce Fields" <bfields@citi.umich.edu>

Addressing patch from Stefan Richter:
HOWTO: update URLs of git trees
(It will be better if we update this to commit-id later)
Signed-off-by: NLi Yang <leoli@freescale.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This is a Chinese translated version of
Documentation/stable_api_nonsense.txt.

From: TripleX <zhongyu@18mail.cn>
Signed-off-by: NWANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: NLi Yang <leoli@freescale.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This is a Chinese translated version of Documentation/HOWTO.  Currently
Chinese involvement in Linux kernel is very low, especially comparing to
its largest population base.  Language could be the main obstacle.  Hope
this document will help more Chinese to contribute to Linux kernel.
Signed-off-by: NLi Yang <leoli@freescale.com>
Signed-off-by: NTripleX Chung <xxx.phy@gmail.com>
Signed-off-by: NMaggie Chen <chenqi@beyondsoft.com>
Signed-off-by: NWANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>