Our gluster boxes get several thousand statfs() calls per second, which begins
to suck hardcore with all of the lock contention on the chunk mutex and dev list
mutex.  We don't really need to hold these things, if we have transient
weirdness with statfs() because of the chunk allocator we don't care, so remove
this locking.

We still need the dev_list lock if you mount with -o alloc_start however, which
is a good argument for nuking that thing from orbit, but that's a patch for
another day.  Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>

Our gluster boxes were spending lots of time in statfs because our fs'es are
huge.  The problem is statfs loops through all of the block groups looking for
read only block groups, and when you have several terabytes worth of data that
ends up being a lot of block groups.  Move the read only block groups onto a
read only list and only proces that list in
btrfs_account_ro_block_groups_free_space to reduce the amount of churn.  Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>

Copy&paste errors in some messages and add few more missing macro
accessors.
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>

The xfstest btrfs/014 which tests the balance operation caused that the
check_int module complained that known blocks changed their physical
location. Since this is not an error in this case, only print such
message if the verbose mode was enabled.
Reported-by: Wang Shilong <wangshilong1991@gmail.com>
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Tested-by: Wang Shilong <wangshilong1991@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>

The xfstest btrfs/014 which tests the balance operation caused issues with
the check_int module. The attempt was made to use btrfs_map_block() to
find the physical location for a written block. However, this was not
at all needed since the location of the written block was known since
a hook to submit_bio() was the reason for entering the check_int module.
Additionally, after a block relocation it happened that btrfs_map_block()
failed causing misleading error messages afterwards.

This patch changes the check_int module to use the known information of
the physical location from the bio.
Reported-by: Wang Shilong <wangshilong1991@gmail.com>
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Tested-by: Wang Shilong <wangshilong1991@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>

We try to allocate an extent state before acquiring the tree's spinlock
just in case we end up needing to split an existing extent state into two.
If that allocation failed, we would return -ENOMEM.
However, our only single caller (transaction/log commit code), passes in
an extent state that was cached from a call to find_first_extent_bit() and
that has a very high chance to match exactly the input range (always true
for a transaction commit and very often, but not always, true for a log
commit) - in this case we end up not needing at all that initial extent
state used for an eventual split. Therefore just don't return -ENOMEM if
we can't allocate the temporary extent state, since we might not need it
at all, and if we end up needing one, we'll do it later anyway.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>

Right now the only caller of find_first_extent_bit() that is interested
in caching extent states (transaction or log commit), never gets an extent
state cached. This is because find_first_extent_bit() only caches states
that have at least one of the flags EXTENT_IOBITS or EXTENT_BOUNDARY, and
the transaction/log commit caller always passes a tree that doesn't have
ever extent states with any of those flags (they can only have one of the
following flags: EXTENT_DIRTY, EXTENT_NEW or EXTENT_NEED_WAIT).

This change together with the following one in the patch series (titled
"Btrfs: avoid returning -ENOMEM in convert_extent_bit() too early") will
help reduce significantly the chances of calls to convert_extent_bit()
fail with -ENOMEM when called from the transaction/log commit code.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>

When committing a transaction or a log, we look for btree extents that
need to be durably persisted by searching for ranges in a io tree that
have some bits set (EXTENT_DIRTY or EXTENT_NEW). We then attempt to clear
those bits and set the EXTENT_NEED_WAIT bit, with calls to the function
convert_extent_bit, and then start writeback for the extents.

That function however can return an error (at the moment only -ENOMEM
is possible, specially when it does GFP_ATOMIC allocation requests
through alloc_extent_state_atomic) - that means the ranges didn't got
the EXTENT_NEED_WAIT bit set (or at least not for the whole range),
which in turn means a call to btrfs_wait_marked_extents() won't find
those ranges for which we started writeback, causing a transaction
commit or a log commit to persist a new superblock without waiting
for the writeback of extents in that range to finish first.

Therefore if a crash happens after persisting the new superblock and
before writeback finishes, we have a superblock pointing to roots that
weren't fully persisted or roots that point to nodes or leafs that weren't
fully persisted, causing all sorts of unexpected/bad behaviour as we endup
reading garbage from disk or the content of some node/leaf from a past
generation that got cowed or deleted and is no longer valid (for this later
case we end up getting error messages like "parent transid verify failed on
X wanted Y found Z" when reading btree nodes/leafs from disk).
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>

device replace could fail due to another running scrub process or any
other errors btrfs_scrub_dev() may hit, but this failure doesn't get
returned to userspace.

The following steps could reproduce this issue

	mkfs -t btrfs -f /dev/sdb1 /dev/sdb2
	mount /dev/sdb1 /mnt/btrfs
	while true; do btrfs scrub start -B /mnt/btrfs >/dev/null 2>&1; done &
	btrfs replace start -Bf /dev/sdb2 /dev/sdb3 /mnt/btrfs
	# if this replace succeeded, do the following and repeat until
	# you see this log in dmesg
	# BTRFS: btrfs_scrub_dev(/dev/sdb2, 2, /dev/sdb3) failed -115
	#btrfs replace start -Bf /dev/sdb3 /dev/sdb2 /mnt/btrfs

	# once you see the error log in dmesg, check return value of
	# replace
	echo $?

Introduce a new dev replace result

BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS

to catch -EINPROGRESS explicitly and return other errors directly to
userspace.
Signed-off-by: Eryu Guan <guaneryu@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>

size of @btrfsic_state needs more than 2M, it is very likely to
fail allocating memory using kzalloc(). see following mesage:

[91428.902148] Call Trace:
[<ffffffff816f6e0f>] dump_stack+0x4d/0x66
[<ffffffff811b1c7f>] warn_alloc_failed+0xff/0x170
[<ffffffff811b66e1>] __alloc_pages_nodemask+0x951/0xc30
[<ffffffff811fd9da>] alloc_pages_current+0x11a/0x1f0
[<ffffffff811b1e0b>] ? alloc_kmem_pages+0x3b/0xf0
[<ffffffff811b1e0b>] alloc_kmem_pages+0x3b/0xf0
[<ffffffff811d1018>] kmalloc_order+0x18/0x50
[<ffffffff811d1074>] kmalloc_order_trace+0x24/0x140
[<ffffffffa06c097b>] btrfsic_mount+0x8b/0xae0 [btrfs]
[<ffffffff810af555>] ? check_preempt_curr+0x85/0xa0
[<ffffffff810b2de3>] ? try_to_wake_up+0x103/0x430
[<ffffffffa063d200>] open_ctree+0x1bd0/0x2130 [btrfs]
[<ffffffffa060fdde>] btrfs_mount+0x62e/0x8b0 [btrfs]
[<ffffffff811fd9da>] ? alloc_pages_current+0x11a/0x1f0
[<ffffffff811b0a5e>] ? __get_free_pages+0xe/0x50
[<ffffffff81230429>] mount_fs+0x39/0x1b0
[<ffffffff812509fb>] vfs_kern_mount+0x6b/0x150
[<ffffffff812537fb>] do_mount+0x27b/0xc30
[<ffffffff811b0a5e>] ? __get_free_pages+0xe/0x50
[<ffffffff812544f6>] SyS_mount+0x96/0xf0
[<ffffffff81701970>] system_call_fastpath+0x16/0x1b

Since we are allocating memory for hash table array, so
it will be good if we could allocate continuous pages here.

Fix this problem by firstly trying kzalloc(), if we fail,
use vzalloc() instead.
Signed-off-by: Wang Shilong <wangshilong1991@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>

If cow_file_range_inline() failed, when called from compress_file_range(),
we were tagging the locked page for writeback, end its writeback and unlock it,
but not marking it with an error nor setting AS_EIO in inode's mapping flags.

This made it impossible for a caller of filemap_fdatawrite_range (writepages)
or filemap_fdatawait_range() to know that an error happened. And the return
value of compress_file_range() is useless because it's returned to a workqueue
task and not to the task calling filemap_fdatawrite_range (writepages).

This change applies on top of the previous patchset starting at the patch
titled:

    "[1/5] Btrfs: set page and mapping error on compressed write failure"

Which changed extent_clear_unlock_delalloc() to use SetPageError and
mapping_set_error().
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>

To avoid duplicating this double filemap_fdatawrite_range() call for
inodes with async extents (compressed writes) so often.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>

For compressed writes, after doing the first filemap_fdatawrite_range() we
don't get the pages tagged for writeback immediately. Instead we create
a workqueue task, which is run by other kthread, and keep the pages locked.
That other kthread compresses data, creates the respective ordered extent/s,
tags the pages for writeback and unlocks them. Therefore we need a second
call to filemap_fdatawrite_range() if we have compressed writes, as this
second call will wait for the pages to become unlocked, then see they became
tagged for writeback and finally wait for the writeback to finish.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>

Its return value is useless, its single caller ignores it and can't do
anything with it anyway, since it's a workqueue task and not the task
calling filemap_fdatawrite_range (writepages) nor filemap_fdatawait_range().
Failure is communicated to such functions via start and end of writeback
with the respective pages tagged with an error and AS_EIO flag set in the
inode's imapping.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>

Steps to reproduce:
 # mkfs.btrfs -f /dev/sdb
 # mount -t btrfs /dev/sdb /mnt -o compress=lzo
 # dd if=/dev/zero of=/mnt/data bs=$((33*4096)) count=1

after previous steps, inode will be detected as bad compression ratio,
and NOCOMPRESS flag will be set for that inode.

Reason is that compress have a max limit pages every time(128K), if a
132k write in, it will be splitted into two write(128k+4k), this bug
is a leftover for commit 68bb462d(Btrfs: don't compress for a small write)

Fix this problem by checking every time before compression, if it is a
small write(<=blocksize), we bail out and fall into nocompression directly.
Signed-off-by: Wang Shilong <wangshilong1991@gmail.com>
Reviewed-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

Our compressed bio write end callback was essentially ignoring the error
parameter. When a write error happens, it must pass a value of 0 to the
inode's write_page_end_io_hook callback, SetPageError on the respective
pages and set AS_EIO in the inode's mapping flags, so that a call to
filemap_fdatawait_range() / filemap_fdatawait() can find out that errors
happened (we surely don't want silent failures on fsync for example).
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>

Its return value is completely ignored by its single caller and it's
useless anyway, since errors are indicated through SetPageError and
the bit AS_EIO set in the flags of the inode's mapping. The caller
can't do anything with the value, as it's invoked from a workqueue
task and not by the task calling filemap_fdatawrite_range (which calls
the writepages address space callback, which in turn calls the inode's
fill_delalloc callback).
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>

If we had an error when processing one of the async extents from our list,
we were not processing the remaining async extents, meaning we would leak
those async_extent structs, never release the pages with the compressed
data and never unlock and clear the dirty flag from the inode's pages (those
that correspond to the uncompressed content).
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>

In inode.c:submit_compressed_extents(), if we fail before calling
btrfs_submit_compressed_write(), or when that function fails, we
were freeing the async_extent structure without releasing its pages
and freeing the pages array.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>

In inode.c:submit_compressed_extents(), before calling btrfs_submit_compressed_write()
we start writeback for all pages, clear their dirty flag, unlock them, etc, but if
btrfs_submit_compressed_write() fails (at the moment it can only fail with -ENOMEM),
we never end the writeback on the pages, so any filemap_fdatawait_range() call will
hang forever. We were also not calling the writepage end io hook, which means the
corresponding ordered extent will never complete and all its waiters will block
forever, such as a full fsync (via btrfs_wait_ordered_range()).
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>

If we fail in submit_compressed_extents() before calling btrfs_submit_compressed_write(),
we start and end the writeback for the pages (clear their dirty flag, unlock them, etc)
but we don't tag the pages, nor the inode's mapping, with an error. This makes it
impossible for a caller of filemap_fdatawait_range() (fsync, or transaction commit
for e.g.) know that there was an error.

Note that the return value of submit_compressed_extents() is useless, as that function
is executed by a workqueue task and not directly by the fill_delalloc callback. This
means the writepage/s callbacks of the inode's address space operations don't get that
return value.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>

Pull ARM SoC fixes from Olof Johansson:
 "Another small set of fixes:

   - some DT compatible typo fixes
   - irq setup fix dealing with irq storms on orion
   - i2c quirk generalization for mvebu
   - a handful of smaller fixes for OMAP
   - a couple of added file patterns for OMAP entries in MAINTAINERS"

* tag 'armsoc-for-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  ARM: at91/dt: Fix sama5d3x typos
  pinctrl: dra: dt-bindings: Fix output pull up/down
  MAINTAINERS: Update entry for omap related .dts files to cover new SoCs
  MAINTAINERS: add more files under OMAP SUPPORT
  ARM: dts: AM437x-SK-EVM: Fix DCDC3 voltage
  ARM: dts: AM437x-GP-EVM: Fix DCDC3 voltage
  ARM: dts: AM43x-EPOS-EVM: Fix DCDC3 voltage
  ARM: dts: am335x-evm: Fix 5th NAND partition's name
  ARM: orion: Fix for certain sequence of request_irq can cause irq storm
  ARM: mvebu: armada xp: Generalize use of i2c quirk

Pull sparc fixes from David Miller:

 1) Fix NULL oops in Schizo PCI controller error handler.

 2) Fix race between xchg and other operations on 32-bit sparc, from
    Andreas Larsson.

 3) swab*() helpers need a dummy memory input operand to show data flow
    on 64-bit sparc.

 4) Fix RCU warnings due to missing irq_{enter,exit}() around
    generic_smp_call_function*() calls.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  sparc64: Fix constraints on swab helpers.
  sparc32: Implement xchg and atomic_xchg using ATOMIC_HASH locks
  sparc64: Do irq_{enter,exit}() around generic_smp_call_function*().
  sparc64: Fix crashes in schizo_pcierr_intr_other().

Pull md bugfix from Neil Brown:
 "One fix for md for 3.18.

  This fixes a regression introduced in 3.13"

* tag 'md/3.18-fix' of git://neil.brown.name/md:
  md: Always set RECOVERY_NEEDED when clearing RECOVERY_FROZEN

Some DT files had a typo with a missing "5" in sama5d3x first compatible string.
Signed-off-by: Peter Rosin <peda@axentia.se>
[nicolas.ferre@atmel.com: modify commit log]
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Olof Johansson <olof@lixom.net>

Merge tag 'omap-fixes-against-v3.18-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap into fixes

Merge "omap fixes against v3.18-rc4" from Tony Lindgren:

Few omap fixes for hangs and wrong pinctrl defines, and update
MAINTAINERS file to avoid missing PMIC and SoC related patches:

- Fix random hangs on am437x because of incorrect default
  value for the DDR regulator

- Fix wrong partition name for NAND on am335x-evm

- Fix wrong pinctrl defines for dra7xx

- Update maintainers entries for PMICs and SoCs

* tag 'omap-fixes-against-v3.18-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap:
  pinctrl: dra: dt-bindings: Fix output pull up/down
  MAINTAINERS: Update entry for omap related .dts files to cover new SoCs
  MAINTAINERS: add more files under OMAP SUPPORT
  ARM: dts: AM437x-SK-EVM: Fix DCDC3 voltage
  ARM: dts: AM437x-GP-EVM: Fix DCDC3 voltage
  ARM: dts: AM43x-EPOS-EVM: Fix DCDC3 voltage
  ARM: dts: am335x-evm: Fix 5th NAND partition's name
Signed-off-by: Olof Johansson <olof@lixom.net>

Merge "mvebu fixes for v3.18" from Jason Cooper:

 - Armada XP
    - Generalize i2c quirk

 - orion
    - Fix irq storm caused by specific sequence of request_irq

* tag 'mvebu-fixes-3.18' of git://git.infradead.org/linux-mvebu:
  ARM: orion: Fix for certain sequence of request_irq can cause irq storm
  ARM: mvebu: armada xp: Generalize use of i2c quirk

md_check_recovery will skip any recovery and also clear
MD_RECOVERY_NEEDED if MD_RECOVERY_FROZEN is set.
So when we clear _FROZEN, we must set _NEEDED and ensure that
md_check_recovery gets run.
Otherwise we could miss out on something that is needed.

In particular, this can make it impossible to remove a
failed device from an array is the  'recovery-needed' processing
didn't happen.
Suitable for stable kernels since 3.13.

Cc: stable@vger.kernel.org (3.13+)
Reported-and-tested-by: Joe Lawrence <joe.lawrence@stratus.com>
Fixes: 30b8feb7Signed-off-by: NeilBrown <neilb@suse.de>

We are reading the memory location, so we have to have a memory
constraint in there purely for the sake of showing the data flow
to the compiler.
Reported-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull SCSI fixes from James Bottomley:
 "This is a set of six fixes and a MAINTAINER update.

  The fixes are two multipath (one in Test Unit Ready handling for the
  path checkers and one in the section of code that sends a start unit
  after failover; both of these were perturbed by the scsi-mq update), a
  CD-ROM door locking fix that was likewise introduced by scsi-mq and
  three driver fixes for a previous code update in cxgb4i, megaraid_sas
  and bnx2fc"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  bnx2fc: fix tgt spinlock locking
  megaraid_sas: fix bug in handling return value of pci_enable_msix_range()
  cxgb4i: send abort_rpl correctly
  cxgbi: add maintainer for cxgb3i/cxgb4i
  scsi: TUR path is down after adapter gets reset with multipath
  scsi: call device handler for failed TUR command
  scsi: only re-lock door after EH on devices that were reset

Pull x86 fixes from Ingo Molnar:
 "Microcode fixes, a Xen fix and a KASLR boot loading fix with certain
  memory layouts"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, microcode, AMD: Fix ucode patch stashing on 32-bit
  x86/core, x86/xen/smp: Use 'die_complete' completion when taking CPU down
  x86, microcode: Fix accessing dis_ucode_ldr on 32-bit
  x86, kaslr: Prevent .bss from overlaping initrd
  x86, microcode, AMD: Fix early ucode loading on 32-bit

Al Viro pointed out that the x86-64 csum_partial_copy_from_user() is
somewhat confused about what it should do on errors, notably it mostly
clears the uncopied end result buffer, but misses that for the initial
alignment case.

All users should check for errors, so it's dubious whether the clearing
is even necessary, and Al also points out that we should probably clean
up the calling conventions, but regardless of any future changes to this
function, the fact that it is inconsistent is just annoying.

So make the __get_user() failure path use the same error exit as all the
other errors do.
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: David Miller <davem@davemloft.net>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull ARM fixes from Russell King:
 "Two fixes this time, one to ensure that the kuser helper option
  depends on MMU as they aren't available for noMMU targets (and if the
  option is selected, we end up oopsing.)

  The second fix plugs a corner case with the decompressor, ensuring
  that the instruction stream can see the relocated code in every case
  on ARMv7 CPUs"

* 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
  ARM: 8198/1: make kuser helpers depend on MMU
  ARM: 8191/1: decompressor: ensure I-side picks up relocated code

Pull parisc updates from Helge Deller:
 "Changes include:
   - wire up the bpf syscall
   - remove CONFIG_64BIT usage from some userspace-exported header files
   - use compat functions for msgctl, shmat, shmctl and semtimedop
     syscalls"

* 'parisc-3.18-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Avoid using CONFIG_64BIT in userspace exported headers
  parisc: Use compat layer for msgctl, shmat, shmctl and semtimedop syscalls
  parisc: Use BUILD_BUG() instead of undefined functions
  parisc: Wire up bpf syscall

Pull power supply updates from Sebastian Reichel:
 "Power supply and reset changes for the v3.18-rc:

   - misc. charger-manager fixes
   - year 2038 fix in ab8500_fg
   - fix error handling of bq2415x_charger"

* tag 'for-v3.18-rc' of git://git.infradead.org/battery-2.6:
  power: charger-manager: Fix accessing invalidated power supply after charger unbind
  power: charger-manager: Fix accessing invalidated power supply after fuel gauge unbind
  power: charger-manager: Avoid recursive thermal get_temp call
  power_supply: Add no_thermal property to prevent recursive get_temp calls
  power: bq2415x_charger: Fix memory leak on DTS parsing error
  power: bq2415x_charger: Properly handle ENODEV from power_supply_get_by_phandle
  power: ab8500_fg.c: use 64-bit time types

Pull drm gixes from Dave Airlie:
 - exynos: infinite loop regressions fixed
 - i915: one regression
 - radeon: one race condition on monitor probing
 - noveau: two regressions
 - tegra: one vblank regression fix

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  drm/tegra: dc: Add missing call to drm_vblank_on()
  drm/nouveau/nv50/disp: Fix modeset on G94
  drm/gk20a/fb: fix setting of large page size bit
  drm/radeon: add locking around atombios scratch space usage
  drm/i915: Fix obj->map_and_fenceable across tiling changes
  drm/exynos: fix possible infinite loop issue
  drm/exynos: g2d: fix null pointer dereference
  drm/exynos: resolve infinite loop issue on non multi-platform
  drm/exynos: resolve infinite loop issue on multi-platform

Sasha Levin reports:
 "gcc5 changes the default standard to c11, which makes kernel build
  unhappy

  Explicitly define the kernel standard to be gnu89 which should keep
  everything working exactly like it was before gcc5"

There are multiple small issues with the new default, but the biggest
issue seems to be that the old - and very useful - GNU extension to
allow a cast in front of an initializer has gone away.

Patch updated by Kirill:
 "I'm pretty sure all gcc versions you can build kernel with supports
  -std=gnu89.  cc-option is redunrant.

  We also need to adjust HOSTCFLAGS otherwise allmodconfig fails for me"

Note by Andrew Pinski:
 "Yes it was reported and both problems relating to this extension has
  been added to gnu99 and gnu11.  Though there are other issues with the
  kernel dealing with extern inline have different semantics between
  gnu89 and gnu99/11"

End result: we may be able to move up to a newer stdc model eventually,
but right now the newer models have some annoying deficiencies, so the
traditional "gnu89" model ends up being the preferred one.
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Singed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull NFS client bugfixes from Trond Myklebust:
 "Highlights include:

   - stable patches to fix NFSv4.x delegation reclaim error paths
   - fix a bug whereby we were advertising NFSv4.1 but using NFSv4.2
     features
   - fix a use-after-free problem with pNFS block layouts
   - fix a memory leak in the pNFS files O_DIRECT code
   - replace an intrusive and Oops-prone performance fix in the NFSv4
     atomic open code with a safer one-line version and revert the two
     original patches"

* tag 'nfs-for-3.18-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  sunrpc: fix sleeping under rcu_read_lock in gss_stringify_acceptor
  NFS: Don't try to reclaim delegation open state if recovery failed
  NFSv4: Ensure that we call FREE_STATEID when NFSv4.x stateids are revoked
  NFSv4: Fix races between nfs_remove_bad_delegation() and delegation return
  NFSv4.1: nfs41_clear_delegation_stateid shouldn't trust NFS_DELEGATED_STATE
  NFSv4: Ensure that we remove NFSv4.0 delegations when state has expired
  NFS: SEEK is an NFS v4.2 feature
  nfs: Fix use of uninitialized variable in nfs_getattr()
  nfs: Remove bogus assignment
  nfs: remove spurious WARN_ON_ONCE in write path
  pnfs/blocklayout: serialize GETDEVICEINFO calls
  nfs: fix pnfs direct write memory leak
  Revert "NFS: nfs4_do_open should add negative results to the dcache."
  Revert "NFS: remove BUG possibility in nfs4_open_and_get_state"
  NFSv4: Ensure nfs_atomic_open set the dentry verifier on ENOENT

Pull input subsystem updates from Dmitry Torokhov:
 "Mostly small fixups to PS/2 tochpad drivers (ALPS, Elantech,
  Synaptics) to better deal with specific hardware"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: elantech - update the documentation
  Input: elantech - provide a sysfs knob for crc_enabled
  Input: elantech - report the middle button of the touchpad
  Input: alps - ignore bad data on Dell Latitudes E6440 and E7440
  Input: alps - allow up to 2 invalid packets without resetting device
  Input: alps - ignore potential bare packets when device is out of sync
  Input: elantech - fix crc_enabled for Fujitsu H730
  Input: elantech - use elantech_report_trackpoint for hardware v4 too
  Input: twl4030-pwrbutton - ensure a wakeup event is recorded.
  Input: synaptics - add min/max quirk for Lenovo T440s