It's unsafe to change the configurations of an activated ITS directly
since this will lead to unpredictable results. This patch guarantees
the ITSes being initialized are quiescent.
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NYun Wu <wuyun.wu@huawei.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1425659870-11832-12-git-send-email-marc.zyngier@arm.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

Define macros for GITS_CTLR fields to avoid using magic numbers.
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NYun Wu <wuyun.wu@huawei.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1425659870-11832-11-git-send-email-marc.zyngier@arm.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

When required size of Device Table is out of the page allocator's
capability, the whole ITS will fail in probing. This actually is
not the hardware's problem and is mainly a limitation of the kernel
page allocator. This patch will keep ITS going on to the next
initializaion stage with an explicit warning.
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NYun Wu <wuyun.wu@huawei.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1425659870-11832-10-git-send-email-marc.zyngier@arm.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

The field of page size in register GITS_BASERn might be read-only
if an implementation only supports a single, fixed page size. But
currently the ITS driver will throw out an error when PAGE_SIZE
is less than the minimum size supported by an ITS. So addressing
this problem by using 64KB pages as default granule for all the
ITS base tables.
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
[maz: fixed bug breaking non Device Table allocations]
Signed-off-by: NYun Wu <wuyun.wu@huawei.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1425659870-11832-9-git-send-email-marc.zyngier@arm.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

Some kind of brain-dead implementations chooses to insert ITEes in
rapid sequence of disabled ITEes, and an un-zeroed ITT will confuse
ITS on judging whether an ITE is really enabled or not. Considering
the implementations are still supported by the GICv3 architecture,
in which ITT is not required to be zeroed before being handled to
hardware, we do the favor in ITS driver.
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NYun Wu <wuyun.wu@huawei.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1425659870-11832-8-git-send-email-marc.zyngier@arm.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

While playing with KASan support for arm64/arm the following appeared on boot:

==================================================================
BUG: AddressSanitizer: out of bounds access in __asan_load8+0x14/0x1c at addr ffffffc000ad0dc0
Read of size 8 by task swapper/0/1
page:ffffffbdc202b400 count:1 mapcount:0 mapping:          (null) index:0x0
flags: 0x400(reserved)
page dumped because: kasan: bad access detected
Address belongs to variable __cpu_logical_map+0x200/0x220
CPU: 2 PID: 1 Comm: swapper/0 Not tainted 3.19.0-rc6-next-20150129+ #481
Hardware name: FVP Base (DT)
Call trace:
[<ffffffc00008a794>] dump_backtrace+0x0/0x184
[<ffffffc00008a928>] show_stack+0x10/0x1c
[<ffffffc00075e46c>] dump_stack+0xa0/0xf8
[<ffffffc0001df490>] kasan_report_error+0x23c/0x264
[<ffffffc0001e0188>] check_memory_region+0xc0/0xe4
[<ffffffc0001dedf0>] __asan_load8+0x10/0x1c
[<ffffffc000431294>] gic_raise_softirq+0xc4/0x1b4
[<ffffffc000091fc0>] smp_send_reschedule+0x30/0x3c
[<ffffffc0000f0d1c>] try_to_wake_up+0x394/0x434
[<ffffffc0000f0de8>] wake_up_process+0x2c/0x6c
[<ffffffc0000d9570>] wake_up_worker+0x38/0x48
[<ffffffc0000dbb50>] insert_work+0xac/0xec
[<ffffffc0000dbd38>] __queue_work+0x1a8/0x374
[<ffffffc0000dbf60>] queue_work_on+0x5c/0x7c
[<ffffffc0000d8a78>] call_usermodehelper_exec+0x170/0x188
[<ffffffc0004037b8>] kobject_uevent_env+0x650/0x6bc
[<ffffffc000403830>] kobject_uevent+0xc/0x18
[<ffffffc00040292c>] kset_register+0xa8/0xc8
[<ffffffc0004d6c88>] bus_register+0x134/0x2e8
[<ffffffc0004d73b4>] subsys_virtual_register+0x2c/0x5c
[<ffffffc000a76a4c>] wq_sysfs_init+0x14/0x20
[<ffffffc000082a28>] do_one_initcall+0xa8/0x1fc
[<ffffffc000a70db4>] kernel_init_freeable+0x1ec/0x294
[<ffffffc00075aa5c>] kernel_init+0xc/0xec
Memory state around the buggy address:
 ffffff80003e0820: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffff80003e0830: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffff80003e0840: fa fa fa fa 00 00 00 00 00 00 00 00 00 00 00 00
                   ^
 ffffff80003e0850: 00 00 fa fa fa fa fa fa 00 00 00 00 00 00 00 00
==================================================================

The reason for that cpumask_next() returns >= nr_cpu_ids if no further cpus
set, but "==" condition is checked only, so we end up with out-of-bounds
access to cpu_logical_map.

Fix is by using the condition check for cpumask_next.
Signed-off-by: NVladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1425659870-11832-7-git-send-email-marc.zyngier@arm.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

When compiled with CONFIG_LOCKDEP, the kernel shouts badly, saying
that the locking in the GIC code is unsafe. I'm afraid the kernel
is right:

       CPU0
       ----
  lock(irq_controller_lock);
  <Interrupt>
    lock(irq_controller_lock);

 *** DEADLOCK ***

This can happen while enabling, disabling, setting the type
or the affinity of an interrupt.

The fix is to take the interrupt_controller_lock with interrupts
disabled in these cases.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1425659870-11832-6-git-send-email-marc.zyngier@arm.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

When compiled with CONFIG_LOCKDEP, the kernel shouts badly, saying
that my locking is unsafe. I'm afraid the kernel is right:

       CPU0                    CPU1
       ----                    ----
  lock(&its->lock);
                               local_irq_disable();
                               lock(&irq_desc_lock_class);
                               lock(&its->lock);
  <Interrupt>
    lock(&irq_desc_lock_class);

 *** DEADLOCK ***

The fix is to always take its->lock with interrupts disabled.
Reported-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1425659870-11832-5-git-send-email-marc.zyngier@arm.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

The current PCI/MSI support in the GICv3 ITS doesn't really deal
with systems where different PCI devices end-up using the same
RequesterID (as it would be the case with non-transparent bridges,
for example). It is likely that none of these devices would
actually generate any interrupt, as the ITS is programmed with
the device's own ID, and not that of the bridge.

A solution to this is to iterate over the PCI hierarchy to
discover what the device aliases too. We also use this
to discover the upper bound of the number of MSIs that this
sub-hierarchy can generate.

With this in place, PCI aliases can be supported.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1425659870-11832-4-git-send-email-marc.zyngier@arm.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

The ITS table allocator is only allocating a single page per table.
This works fine for most things, but leads to silent lack of
interrupt delivery if we end-up with a device that has an ID that is
out of the range defined by a single page of memory. Even worse, depending
on the page size, behaviour changes, which is not a very good experience.

A solution is actually to allocate memory for the full range of ID that
the ITS supports. A massive waste memory wise, but at least a safe bet.

Tested on a Phytium SoC.
Tested-by: NChen Baozi <chenbaozi@kylinos.com.cn>
Acked-by: NChen Baozi <chenbaozi@kylinos.com.cn>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1425659870-11832-3-git-send-email-marc.zyngier@arm.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

We skip initialisation of ITS in case the device-tree has no
corresponding description, but we are still accessing to ITS bits while
setting CPU interface what leads to the kernel panic:

ITS: No ITS available, not enabling LPIs
CPU0: found redistributor 0 region 0:0x000000002f100000
Unable to handle kernel NULL pointer dereference at virtual address 00000000
pgd = ffffffc0007fb000
[00000000] *pgd=00000000fc407003, *pud=00000000fc407003, *pmd=00000000fc408003, *pte=006000002f000707
Internal error: Oops: 96000005 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.19.0-rc2+ #318
Hardware name: FVP Base (DT)
task: ffffffc00077edb0 ti: ffffffc00076c000 task.ti: ffffffc00076c000
PC is at its_cpu_init+0x2c/0x320
LR is at gic_cpu_init+0x168/0x1bc

It happens in gic_rdists_supports_plpis() because gic_rdists is NULL.
The gic_rdists is set to non-NULL only when ITS node is presented in
the device-tree.

Fix this by moving the call to gic_rdists_supports_plpis() inside the
!list_empty(&its_nodes) block, because it is that list that guards the
validity of the rest of the information in this driver.
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NVladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1425659870-11832-2-git-send-email-marc.zyngier@arm.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

On the Cortex-A9-based Armada SoCs, the MPIC is not the primary interrupt
controller. Yet, it still has to handle some per-cpu interrupt.

To do so, it is chained with the GIC using a per-cpu interrupt. However, the
current code only call irq_set_chained_handler, which is called and enable that
interrupt only on the boot CPU, which means that the parent per-CPU interrupt
is never unmasked on the secondary CPUs, preventing the per-CPU interrupt to
actually work as expected.

This was not seen until now since the only MPIC PPI users were the Marvell
timers that were not working, but not used either since the system use the ARM
TWD by default, and the ethernet controllers, that are faking there interrupts
as SPI, and don't really expect to have interrupts on the secondary cores
anyway.

Add a CPU notifier that will enable the PPI on the secondary cores when they
are brought up.

Cc: <stable@vger.kernel.org> # 3.15+
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: NGregory CLEMENT <gregory.clement@free-electrons.com>
Link: https://lkml.kernel.org/r/1425378443-28822-1-git-send-email-maxime.ripard@free-electrons.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

.. after extensive statistical analysis of my G+ polling, I've come to
the inescapable conclusion that internet polls are bad.

Big surprise.

But "Hurr durr I'ma sheep" trounced "I like online polls" by a 62-to-38%
margin, in a poll that people weren't even supposed to participate in.
Who can argue with solid numbers like that? 5,796 votes from people who
can't even follow the most basic directions?

In contrast, "v4.0" beat out "v3.20" by a slimmer margin of 56-to-44%,
but with a total of 29,110 votes right now.

Now, arguably, that vote spread is only about 3,200 votes, which is less
than the almost six thousand votes that the "please ignore" poll got, so
it could be considered noise.

But hey, I asked, so I'll honor the votes.

Pull ext4 fixes from Ted Ts'o:
 "Ext4 bug fixes.

  We also reserved code points for encryption and read-only images (for
  which the implementation is mostly just the reserved code point for a
  read-only feature :-)"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: fix indirect punch hole corruption
  ext4: ignore journal checksum on remount; don't fail
  ext4: remove duplicate remount check for JOURNAL_CHECKSUM change
  ext4: fix mmap data corruption in nodelalloc mode when blocksize < pagesize
  ext4: support read-only images
  ext4: change to use setup_timer() instead of init_timer()
  ext4: reserve codepoints used by the ext4 encryption feature
  jbd2: complain about descriptor block checksum errors

Pull more vfs updates from Al Viro:
 "Assorted stuff from this cycle.  The big ones here are multilayer
  overlayfs from Miklos and beginning of sorting ->d_inode accesses out
  from David"

* 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (51 commits)
  autofs4 copy_dev_ioctl(): keep the value of ->size we'd used for allocation
  procfs: fix race between symlink removals and traversals
  debugfs: leave freeing a symlink body until inode eviction
  Documentation/filesystems/Locking: ->get_sb() is long gone
  trylock_super(): replacement for grab_super_passive()
  fanotify: Fix up scripted S_ISDIR/S_ISREG/S_ISLNK conversions
  Cachefiles: Fix up scripted S_ISDIR/S_ISREG/S_ISLNK conversions
  VFS: (Scripted) Convert S_ISLNK/DIR/REG(dentry->d_inode) to d_is_*(dentry)
  SELinux: Use d_is_positive() rather than testing dentry->d_inode
  Smack: Use d_is_positive() rather than testing dentry->d_inode
  TOMOYO: Use d_is_dir() rather than d_inode and S_ISDIR()
  Apparmor: Use d_is_positive/negative() rather than testing dentry->d_inode
  Apparmor: mediated_filesystem() should use dentry->d_sb not inode->i_sb
  VFS: Split DCACHE_FILE_TYPE into regular and special types
  VFS: Add a fallthrough flag for marking virtual dentries
  VFS: Add a whiteout dentry type
  VFS: Introduce inode-getting helpers for layered/unioned fs environments
  Infiniband: Fix potential NULL d_inode dereference
  posix_acl: fix reference leaks in posix_acl_create
  autofs4: Wrong format for printing dentry
  ...

Pull ARM fix from Russell King:
 "Just one fix this time around.  __iommu_alloc_buffer() can cause a
  BUG() if dma_alloc_coherent() is called with either __GFP_DMA32 or
  __GFP_HIGHMEM set.  The patch from Alexandre addresses this"

* 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
  ARM: 8305/1: DMA: Fix kzalloc flags in __iommu_alloc_buffer()

X-Coverup: just ask spender
Cc: stable@vger.kernel.org
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

use_pde()/unuse_pde() in ->follow_link()/->put_link() resp.

Cc: stable@vger.kernel.org
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

As it is, we have debugfs_remove() racing with symlink traversals.
Supply ->evict_inode() and do freeing there - inode will remain
pinned until we are done with the symlink body.

And rip the idiocy with checking if dentry is positive right after
we'd verified debugfs_positive(), which is a stronger check...

Cc: stable@vger.kernel.org
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

I've noticed significant locking contention in memory reclaimer around
sb_lock inside grab_super_passive(). Grab_super_passive() is called from
two places: in icache/dcache shrinkers (function super_cache_scan) and
from writeback (function __writeback_inodes_wb). Both are required for
progress in memory allocator.

Grab_super_passive() acquires sb_lock to increment sb->s_count and check
sb->s_instances. It seems sb->s_umount locked for read is enough here:
super-block deactivation always runs under sb->s_umount locked for write.
Protecting super-block itself isn't a problem: in super_cache_scan() sb
is protected by shrinker_rwsem: it cannot be freed if its slab shrinkers
are still active. Inside writeback super-block comes from inode from bdi
writeback list under wb->list_lock.

This patch removes locking sb_lock and checks s_instances under s_umount:
generic_shutdown_super() unlinks it under sb->s_umount locked for write.
New variant is called trylock_super() and since it only locks semaphore,
callers must call up_read(&sb->s_umount) instead of drop_super(sb) when
they're done.
Signed-off-by: NKonstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Fanotify probably doesn't want to watch autodirs so make it use d_can_lookup()
rather than d_is_dir() when checking a dir watch and give an error on fake
directories.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Fix up the following scripted S_ISDIR/S_ISREG/S_ISLNK conversions (or lack
thereof) in cachefiles:

 (1) Cachefiles mostly wants to use d_can_lookup() rather than d_is_dir() as
     it doesn't want to deal with automounts in its cache.

 (2) Coccinelle didn't find S_IS* expressions in ASSERT() statements in
     cachefiles.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Convert the following where appropriate:

 (1) S_ISLNK(dentry->d_inode) to d_is_symlink(dentry).

 (2) S_ISREG(dentry->d_inode) to d_is_reg(dentry).

 (3) S_ISDIR(dentry->d_inode) to d_is_dir(dentry).  This is actually more
     complicated than it appears as some calls should be converted to
     d_can_lookup() instead.  The difference is whether the directory in
     question is a real dir with a ->lookup op or whether it's a fake dir with
     a ->d_automount op.

In some circumstances, we can subsume checks for dentry->d_inode not being
NULL into this, provided we the code isn't in a filesystem that expects
d_inode to be NULL if the dirent really *is* negative (ie. if we're going to
use d_inode() rather than d_backing_inode() to get the inode pointer).

Note that the dentry type field may be set to something other than
DCACHE_MISS_TYPE when d_inode is NULL in the case of unionmount, where the VFS
manages the fall-through from a negative dentry to a lower layer.  In such a
case, the dentry type of the negative union dentry is set to the same as the
type of the lower dentry.

However, if you know d_inode is not NULL at the call site, then you can use
the d_is_xxx() functions even in a filesystem.

There is one further complication: a 0,0 chardev dentry may be labelled
DCACHE_WHITEOUT_TYPE rather than DCACHE_SPECIAL_TYPE.  Strictly, this was
intended for special directory entry types that don't have attached inodes.

The following perl+coccinelle script was used:

use strict;

my @callers;
open($fd, 'git grep -l \'S_IS[A-Z].*->d_inode\' |') ||
    die "Can't grep for S_ISDIR and co. callers";
@callers = <$fd>;
close($fd);
unless (@callers) {
    print "No matches\n";
    exit(0);
}

my @cocci = (
    '@@',
    'expression E;',
    '@@',
    '',
    '- S_ISLNK(E->d_inode->i_mode)',
    '+ d_is_symlink(E)',
    '',
    '@@',
    'expression E;',
    '@@',
    '',
    '- S_ISDIR(E->d_inode->i_mode)',
    '+ d_is_dir(E)',
    '',
    '@@',
    'expression E;',
    '@@',
    '',
    '- S_ISREG(E->d_inode->i_mode)',
    '+ d_is_reg(E)' );

my $coccifile = "tmp.sp.cocci";
open($fd, ">$coccifile") || die $coccifile;
print($fd "$_\n") || die $coccifile foreach (@cocci);
close($fd);

foreach my $file (@callers) {
    chomp $file;
    print "Processing ", $file, "\n";
    system("spatch", "--sp-file", $coccifile, $file, "--in-place", "--no-show-diff") == 0 ||
	die "spatch failed";
}

[AV: overlayfs parts skipped]
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Use d_is_positive() rather than testing dentry->d_inode in SELinux to get rid
of direct references to d_inode outside of the VFS.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Use d_is_positive() rather than testing dentry->d_inode in Smack to get rid of
direct references to d_inode outside of the VFS.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Use d_is_dir() rather than d_inode and S_ISDIR().  Note that this will include
fake directories such as automount triggers.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Use d_is_positive(dentry) or d_is_negative(dentry) rather than testing
dentry->d_inode as the dentry may cover another layer that has an inode when
the top layer doesn't or may hold a 0,0 chardev that's actually a whiteout.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

mediated_filesystem() should use dentry->d_sb not dentry->d_inode->i_sb and
should avoid file_inode() also since it is really dealing with the path.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Split DCACHE_FILE_TYPE into DCACHE_REGULAR_TYPE (dentries representing regular
files) and DCACHE_SPECIAL_TYPE (representing blockdev, chardev, FIFO and
socket files).

d_is_reg() and d_is_special() are added to detect these subtypes and
d_is_file() is left as the union of the two.

This allows a number of places that use S_ISREG(dentry->d_inode->i_mode) to
use d_is_reg(dentry) instead.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Add a DCACHE_FALLTHRU flag to indicate that, in a layered filesystem, this is
a virtual dentry that covers another one in a lower layer that should be used
instead.  This may be recorded on medium if directory integration is stored
there.

The flag can be set with d_set_fallthru() and tested with d_is_fallthru().

Original-author: Valerie Aurora <vaurora@redhat.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Add DCACHE_WHITEOUT_TYPE and provide a d_is_whiteout() accessor function.  A
d_is_miss() accessor is also added for ordinary cache misses and
d_is_negative() is modified to indicate either an ordinary miss or an enforced
miss (whiteout).
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Introduce some function for getting the inode (and also the dentry) in an
environment where layered/unioned filesystems are in operation.

The problem is that we have places where we need *both* the union dentry and
the lower source or workspace inode or dentry available, but we can only have
a handle on one of them.  Therefore we need to derive the handle to the other
from that.

The idea is to introduce an extra field in struct dentry that allows the union
dentry to refer to and pin the lower dentry.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Pull MIPS updates from Ralf Baechle:
 "This is the main pull request for MIPS:

   - a number of fixes that didn't make the 3.19 release.

   - a number of cleanups.

   - preliminary support for Cavium's Octeon 3 SOCs which feature up to
     48 MIPS64 R3 cores with FPU and hardware virtualization.

   - support for MIPS R6 processors.

     Revision 6 of the MIPS architecture is a major revision of the MIPS
     architecture which does away with many of original sins of the
     architecture such as branch delay slots.  This and other changes in
     R6 require major changes throughout the entire MIPS core
     architecture code and make up for the lion share of this pull
     request.

   - finally some preparatory work for eXtendend Physical Address
     support, which allows support of up to 40 bit of physical address
     space on 32 bit processors"

     [ Ahh, MIPS can't leave the PAE brain damage alone.  It's like
       every CPU architect has to make that mistake, but pee in the snow
       by changing the TLA.  But whether it's called PAE, LPAE or XPA,
       it's horrid crud   - Linus ]

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (114 commits)
  MIPS: sead3: Corrected get_c0_perfcount_int
  MIPS: mm: Remove dead macro definitions
  MIPS: OCTEON: irq: add CIB and other fixes
  MIPS: OCTEON: Don't do acknowledge operations for level triggered irqs.
  MIPS: OCTEON: More OCTEONIII support
  MIPS: OCTEON: Remove setting of processor specific CVMCTL icache bits.
  MIPS: OCTEON: Core-15169 Workaround and general CVMSEG cleanup.
  MIPS: OCTEON: Update octeon-model.h code for new SoCs.
  MIPS: OCTEON: Implement DCache errata workaround for all CN6XXX
  MIPS: OCTEON: Add little-endian support to asm/octeon/octeon.h
  MIPS: OCTEON: Implement the core-16057 workaround
  MIPS: OCTEON: Delete unused COP2 saving code
  MIPS: OCTEON: Use correct instruction to read 64-bit COP0 register
  MIPS: OCTEON: Save and restore CP2 SHA3 state
  MIPS: OCTEON: Fix FP context save.
  MIPS: OCTEON: Save/Restore wider multiply registers in OCTEON III CPUs
  MIPS: boot: Provide more uImage options
  MIPS: Remove unneeded #ifdef __KERNEL__ from asm/processor.h
  MIPS: ip22-gio: Remove legacy suspend/resume support
  mips: pci: Add ifdef around pci_proc_domain
  ...

Pull ARM SoC fixes from Arnd Bergmann:
 "A few fixes that came in too late to make it into the first set of
  pull requests but would still be nice to have in -rc1.

  The majority of these are trivial build fixes for bugs that I found
  myself using randconfig testing, and a set of two patches from Uwe to
  mark DT strings as 'const' where appropriate, to resolve inconsistent
  section attributes"

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  ARM: make of_device_ids const
  ARM: make arrays containing machine compatible strings const
  ARM: mm: Remove Kconfig symbol CACHE_PL310
  ARM: rockchip: force built-in regulator support for PM
  ARM: mvebu: build armada375-smp code conditionally
  ARM: sti: always enable RESET_CONTROLLER
  ARM: rockchip: make rockchip_suspend_init conditional
  ARM: ixp4xx: fix {in,out}s{bwl} data types
  ARM: prima2: do not select SMP_ON_UP
  ARM: at91: fix pm declarations
  ARM: davinci: multi-soc kernels require AUTO_ZRELADDR
  ARM: davinci: davinci_cfg_reg cannot be init
  ARM: BCM: put back ARCH_MULTI_V7 dependency for mobile
  ARM: vexpress: use ARM_CPU_SUSPEND if needed
  ARM: dts: add I2C device nodes for Broadcom Cygnus
  ARM: dts: BCM63xx: fix L2 cache properties

Pull misc SCSI patches from James Bottomley:
 "This is a short patch set representing a couple of left overs from the
  merge window (debug removal and MAINTAINER changes).

  Plus one merge window regression (the local workqueue for hpsa) and a
  set of bug fixes for several issues (two for scsi-mq and the rest an
  assortment of long standing stuff, all cc'd to stable)"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  sg: fix EWOULDBLOCK errors with scsi-mq
  sg: fix unkillable I/O wait deadlock with scsi-mq
  sg: fix read() error reporting
  wd719x: add missing .module to wd719x_template
  hpsa: correct compiler warnings introduced by hpsa-add-local-workqueue patch
  fixed invalid assignment of 64bit mask to host dma_boundary for scatter gather segment boundary limit.
  fcoe: Transition maintainership to Vasu
  am53c974: remove left-over debugging code

Merge tag 'xfs-pnfs-for-linus-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs

Pull xfs pnfs block layout support from Dave Chinner:
 "This contains the changes to XFS needed to support the PNFS block
  layout server that you pulled in through Bruce's NFS server tree
  merge.

  I originally thought that I'd need to merge changes into the NFS
  server side, but Bruce had already picked them up and so this is
  purely changes to the fs/xfs/ codebase.

  Summary:

  This update contains the implementation of the PNFS server export
  methods that enable use of XFS filesystems as a block layout target"

* tag 'xfs-pnfs-for-linus-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs:
  xfs: recall pNFS layouts on conflicting access
  xfs: implement pNFS export operations

Pull more NFS client updates from Trond Myklebust:
 "Highlights include:

   - Fix a use-after-free in decode_cb_sequence_args()
   - Fix a compile error when #undef CONFIG_PROC_FS
   - NFSv4.1 backchannel spinlocking issue
   - Cleanups in the NFS unstable write code requested by Linus
   - NFSv4.1 fix issues when the server denies our backchannel request
   - Cleanups in create_session and bind_conn_to_session"

* tag 'nfs-for-3.20-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  NFSv4.1: Clean up bind_conn_to_session
  NFSv4.1: Always set up a forward channel when binding the session
  NFSv4.1: Don't set up a backchannel if the server didn't agree to do so
  NFSv4.1: Clean up create_session
  pnfs: Refactor the *_layout_mark_request_commit to use pnfs_layout_mark_request_commit
  NFSv4: Kill unused nfs_inode->delegation_state field
  NFS: struct nfs_commit_info.lock must always point to inode->i_lock
  nfs: Can call nfs_clear_page_commit() instead
  nfs: Provide and use helper functions for marking a page as unstable
  SUNRPC: Always manipulate rpc_rqst::rq_bc_pa_list under xprt->bc_pa_lock
  SUNRPC: Fix a compile error when #undef CONFIG_PROC_FS
  NFSv4.1: Convert open-coded array allocation calls to kmalloc_array()
  NFSv4.1: Fix a kfree() of uninitialised pointers in decode_cb_sequence_args

Pull one more batch of power management and ACPI updates from Rafael Wysocki:
 "These are mostly fixes on top of the previously merged recent PM and
  ACPI material.

  First, one commit that broke the ACPI LPSS (Low-Power Subsystem)
  driver on a Dell box is reverted and there are two stable-candidate
  fixes for that driver.  Another fix cleans up two recently added ACPI
  EC messages that look odd and the printk level of a noisy debug
  message in the core ACPI resources handling code is reduced.

  In addition to that we have two stable-candidate fixes for the s3c
  cpufreq driver, two cpuidle powernv driver updates related to Device
  Trees and a PNP subsystem cleanup that will allow us to get rid of
  some old ugliness going forward.  Also there is a new blacklist entry
  for the ACPI backlight code.

  Specifics:

   - Revert a recent ACPI LPSS driver commit that prevented the touchpad
     driver from loading on Dell XPS13 (Jarkko Nikula).

   - Make the ACPI LPSS driver disable the I2C controllers and deassert
     SPI host controllers resets at startup on Intel BayTrail and
     Braswell SoCs in case they have been left in wrong states by the
     platform firmware which then may casuse fatal controller driver
     failures during resume from hibernation (Mika Westerberg).

   - Make two recently added ACPI EC messages look better (Scot Doyle).

   - Reduce the printk level of a recently added debug message related
     to ACPI resources that may become noisy in some cases (Rafael J
     Wysocki).

   - Add a new ACPI backlight blacklist entry for Samsung Series 9
     (900X3C/900X3D/900X3E/900X4C/900X4D) laptops where the native
     backlight interface doesn't work while the ACPI based one does
     (Jens Reyer).

   - Make the PNP sybsystem's core code use __request_region() followed
     by __release_region() instead of __check_region() which then will
     allow us to get rid of the latter as it has no more users (Jakub
     Sitnicki).

   - Fix a build breakage and an issue with two __init functions that
     may be called after initialization in the s3c cpufreq driver (Arnd
     Bergmann).

   - Make the powernv cpuidle driver read target_residency values for
     idle states from a Device Tree (as we have the suitable DT bindings
     for that now) and improve the parsing of the powermgmt DT node in
     that driver (Preeti U Murthy)"

* tag 'pm+acpi-3.20-rc1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpuidle: powernv: Avoid endianness conversions while parsing DT
  cpufreq: s3c: remove last use of resume_clocks callback
  cpufreq: s3c: remove incorrect __init annotations
  ACPI / LPSS: Deassert resets for SPI host controllers on Braswell
  ACPI / LPSS: Always disable I2C host controllers
  ACPI / resources: Change pr_info() to pr_debug() for debug information
  ACPI / video: Disable native backlight on Samsung Series 9 laptops
  cpuidle: powernv: Read target_residency value of idle states from DT if available
  Revert "ACPI / LPSS: Remove non-existing clock control from Intel Lynxpoint I2C"
  ACPI / EC: Remove non-standard log emphasis
  PNP: Switch from __check_region() to __request_region()