There is a potential deadlock if mount/umount happens when
raid5_finish_reshape() tries to grow the size of emulated disk.

How the deadlock happens?
1) The raid5 resync thread finished reshape (expanding array).
2) The mount or umount thread holds VFS sb->s_umount lock and tries to
   write through critical data into raid5 emulated block device. So it
   waits for raid5 kernel thread handling stripes in order to finish it
   I/Os.
3) In the routine of raid5 kernel thread, md_check_recovery() will be
   called first in order to reap the raid5 resync thread. That is,
   raid5_finish_reshape() will be called. In this function, it will try
   to update conf and call VFS revalidate_disk() to grow the raid5
   emulated block device. It will try to acquire VFS sb->s_umount lock.
The raid5 kernel thread cannot continue, so no one can handle mount/
umount I/Os (stripes). Once the write-through I/Os cannot be finished,
mount/umount will not release sb->s_umount lock. The deadlock happens.

The raid5 kernel thread is an emulated block device. It is responible to
handle I/Os (stripes) from upper layers. The emulated block device
should not request any I/Os on itself. That is, it should not call VFS
layer functions. (If it did, it will try to acquire VFS locks to
guarantee the I/Os sequence.) So we have the resync thread to send
resync I/O requests and to wait for the results.

For solving this potential deadlock, we can put the size growth of the
emulated block device as the final step of reshape thread.

2017/12/29:
Thanks to Guoqing Jiang <gqjiang@suse.com>,
we confirmed that there is the same deadlock issue in raid10. It's
reproducible and can be fixed by this patch. For raid10.c, we can remove
the similar code to prevent deadlock as well since they has been called
before.
Reported-by: NAlex Wu <alexwu@synology.com>
Reviewed-by: NAlex Wu <alexwu@synology.com>
Reviewed-by: NChung-Chiang Cheng <cccheng@synology.com>
Signed-off-by: NBingJing Chang <bingjingc@synology.com>
Signed-off-by: NShaohua Li <sh.li@alibaba-inc.com>

r10conf is already successfully allocated before checking the layout
Signed-off-by: NLidong Zhong <lzhong@suse.com>
Reviewed-by: NGuoqing Jiang <gqjiang@suse.com>
Signed-off-by: NShaohua Li <sh.li@alibaba-inc.com>

gcc warns about a possible overflow of the kmem_cache string, when adding
four characters to a string of the same length:

drivers/md/raid5.c: In function 'setup_conf':
drivers/md/raid5.c:2207:34: error: '-alt' directive writing 4 bytes into a region of size between 1 and 32 [-Werror=format-overflow=]
  sprintf(conf->cache_name[1], "%s-alt", conf->cache_name[0]);
                                  ^~~~
drivers/md/raid5.c:2207:2: note: 'sprintf' output between 5 and 36 bytes into a destination of size 32
  sprintf(conf->cache_name[1], "%s-alt", conf->cache_name[0]);
  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

If I'm counting correctly, we need 11 characters for the fixed part
of the string and 18 characters for a 64-bit pointer (when no gendisk
is used), so that leaves three characters for conf->level, which should
always be sufficient.

This makes the code use snprintf() with the correct length, to
make the code more robust against changes, and to get the compiler
to shut up.

In commit f4be6b43 ("md/raid5: ensure we create a unique name for
kmem_cache when mddev has no gendisk") from 2010, Neil said that
the pointer could be removed "shortly" once devices without gendisk
are disallowed. I have no idea if that happened, but if it did, that
should probably be changed as well.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NShaohua Li <sh.li@alibaba-inc.com>

Add missing bio completion. Without this any flush request would hang.

Fixes: 1532d9e8 ("raid5-ppl: PPL support for disks with write-back cache enabled")
Signed-off-by: NArtur Paszkiewicz <artur.paszkiewicz@intel.com>
Signed-off-by: NShaohua Li <sh.li@alibaba-inc.com>

In the case of 'recover', an r10bio with R10BIO_WriteError &
R10BIO_IsRecover will be progressed by handle_write_completed().
This function traverses all r10bio->devs[copies].
If devs[m].repl_bio != NULL, it thinks conf->mirrors[dev].replacement
is also not NULL. However, this is not always true.

When there is an rdev of raid10 has replacement, then each r10bio
->devs[m].repl_bio != NULL in conf->r10buf_pool. However, in 'recover',
even if corresponded replacement is NULL, it doesn't clear r10bio
->devs[m].repl_bio, resulting in replacement NULL deference.

This bug was introduced when replacement support for raid10 was
added in Linux 3.3.

As NeilBrown suggested:
	Elsewhere the determination of "is this device part of the
	resync/recovery" is made by resting bio->bi_end_io.
	If this is end_sync_write, then we tried to write here.
	If it is NULL, then we didn't try to write.

Fixes: 9ad1aefc ("md/raid10:  Handle replacement devices during resync.")
Cc: stable (V3.3+)
Suggested-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NYufen Yu <yuyufen@huawei.com>
Signed-off-by: NShaohua Li <sh.li@alibaba-inc.com>

The locking protocols in md assume that a device will
never be removed from an array during resync/recovery/reshape.
When that isn't happening, rcu or reconfig_mutex is needed
to protect an rdev pointer while taking a refcount.  When
it is happening, that protection isn't needed.

Unfortunately there are cases were remove_and_add_spares() is
called when recovery might be happening: is state_store(),
slot_store() and hot_remove_disk().
In each case, this is just an optimization, to try to expedite
removal from the personality so the device can be removed from
the array.  If resync etc is happening, we just have to wait
for md_check_recover to find a suitable time to call
remove_and_add_spares().

This optimization and not essential so it doesn't
matter if it fails.
So change remove_and_add_spares() to abort early if
resync/recovery/reshape is happening, unless it is called
from md_check_recovery() as part of a newly started recovery.
The parameter "this" is only NULL when called from
md_check_recovery() so when it is NULL, there is no need to abort.

As this can result in a NULL dereference, the fix is suitable
for -stable.

cc: yuyufen <yuyufen@huawei.com>
Cc: Tomasz Majchrzak <tomasz.majchrzak@intel.com>
Fixes: 8430e7e0 ("md: disconnect device from personality before trying to remove it.")
Cc: stable@ver.kernel.org (v4.8+)
Signed-off-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NShaohua Li <sh.li@alibaba-inc.com>

The rdev pointer kept in the local 'config' for each for
raid1, raid10, raid4/5/6 has non-obvious lifetime rules.
Sometimes RCU is needed, sometimes a lock, something nothing.

Add documentation to explain this.
Signed-off-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NShaohua Li <sh.li@alibaba-inc.com>

If no metadata devices are configured on raid1/4/5/6/10
(e.g. via dm-raid), md_write_start() unconditionally waits
for superblocks to be written thus deadlocking.

Fix introduces mddev->has_superblocks bool, defines it in md_run()
and checks for it in md_write_start() to conditionally avoid waiting.

Once on it, check for non-existing superblocks in md_super_write().

Link: https://bugzilla.kernel.org/show_bug.cgi?id=198647
Fixes: cc27b0c7 ("md: fix deadlock between mddev_suspend() and md_write_start()")
Signed-off-by: NHeinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: NShaohua Li <sh.li@alibaba-inc.com>

Signed-off-by: NXiao Ni <xni@redhat.com>
Acked-by: NGuoqing Jiang <gqjiang@suse.com>
Signed-off-by: NShaohua Li <sh.li@alibaba-inc.com>

To align with raid1's resync window, we need to
set the resync window of raid10 to 32M as well.

Fixes: 8db87912 ("md-cluster: Use a small window for raid10 resync")
Reported-by: NZhilong Liu <zlliu@suse.com>
Signed-off-by: NGuoqing Jiang <gqjiang@suse.com>
Signed-off-by: NShaohua Li <sh.li@alibaba-inc.com>

A single character (closing square bracket) should be put into a sequence.
Thus use the corresponding function "seq_putc".

This issue was detected by using the Coccinelle software.
Signed-off-by: NMarkus Elfring <elfring@users.sourceforge.net>
Signed-off-by: NShaohua Li <sh.li@alibaba-inc.com>

The trailing semicolon is an empty statement that does no operation.
Removing it since it doesn't do anything.
Signed-off-by: NLuis de Bethencourt <luisbg@kernel.org>
Signed-off-by: NShaohua Li <sh.li@alibaba-inc.com>

Don't use shrinker.nr_deferred to check whether shrinker was
initialized or not. Now this check was integrated into
unregister_shrinker(), so it is safe to call it against
unregistered shrinker.
Signed-off-by: NAliaksei Karaliou <akaraliou.dev@gmail.com>
Signed-off-by: NShaohua Li <sh.li@alibaba-inc.com>

Pull block fixes from Jens Axboe:

 - NVMe pull request from Keith, with fixes all over the map for nvme.
   From various folks.

 - Classic polling fix, that avoids a latency issue where we still end
   up waiting for an interrupt in some cases. From Nitesh Shetty.

 - Comment typo fix from Minwoo Im.

* tag 'for-linus-20180217' of git://git.kernel.dk/linux-block:
  block: fix a typo in comment of BLK_MQ_POLL_STATS_BKTS
  nvme-rdma: fix sysfs invoked reset_ctrl error flow
  nvmet: Change return code of discard command if not supported
  nvme-pci: Fix timeouts in connecting state
  nvme-pci: Remap CMB SQ entries on every controller reset
  nvme: fix the deadlock in nvme_update_formats
  blk: optimization for classic polling
  nvme: Don't use a stack buffer for keep-alive command
  nvme_fc: cleanup io completion
  nvme_fc: correct abort race condition on resets
  nvme: Fix discard buffer overrun
  nvme: delete NVME_CTRL_LIVE --> NVME_CTRL_CONNECTING transition
  nvme-rdma: use NVME_CTRL_CONNECTING state to mark init process
  nvme: rename NVME_CTRL_RECONNECTING state to NVME_CTRL_CONNECTING

Pull MMC fixes from Ulf Hansson:

 - meson-gx: Revert to earlier tuning process

 - bcm2835: Don't overwrite max frequency unconditionally

* tag 'mmc-v4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc:
  mmc: bcm2835: Don't overwrite max frequency unconditionally
  Revert "mmc: meson-gx: include tx phase in the tuning process"

Pull mtd fixes from Boris Brezillon:

 - add missing dependency to NAND_MARVELL Kconfig entry

 - use the appropriate OOB layout in the VF610 driver

* tag 'mtd/fixes-for-4.16-rc2' of git://git.infradead.org/linux-mtd:
  mtd: nand: MTD_NAND_MARVELL should depend on HAS_DMA
  mtd: nand: vf610: set correct ooblayout

Pull powerpc fixes from Michael Ellerman:
 "The main attraction is a fix for a bug in the new drmem code, which
  was causing an oops on boot on some versions of Qemu.

  There's also a fix for XIVE (Power9 interrupt controller) on KVM, as
  well as a few other minor fixes.

  Thanks to: Corentin Labbe, Cyril Bur, Cédric Le Goater, Daniel Black,
  Nathan Fontenot, Nicholas Piggin"

* tag 'powerpc-4.16-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/pseries: Check for zero filled ibm,dynamic-memory property
  powerpc/pseries: Add empty update_numa_cpu_lookup_table() for NUMA=n
  powerpc/powernv: IMC fix out of bounds memory access at shutdown
  powerpc/xive: Use hw CPU ids when configuring the CPU queues
  powerpc: Expose TSCR via sysfs only on powernv

Pull arm64 fixes from Catalin Marinas:
 "The bulk of this is the pte accessors annotation to READ/WRITE_ONCE
  (we tried to avoid pushing this during the merge window to avoid
  conflicts)

   - Updated the page table accessors to use READ/WRITE_ONCE and prevent
     compiler transformation that could lead to an apparent loss of
     coherency

   - Enabled branch predictor hardening for the Falkor CPU

   - Fix interaction between kpti enabling and KASan causing the
     recursive page table walking to take a significant time

   - Fix some sparse warnings"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: cputype: Silence Sparse warnings
  arm64: mm: Use READ_ONCE/WRITE_ONCE when accessing page tables
  arm64: proc: Set PTE_NG for table entries to avoid traversing them twice
  arm64: Add missing Falkor part number for branch predictor hardening

Pull xen fixes from Juergen Gross:

 - fixes for the Xen pvcalls frontend driver

 - fix for booting Xen pv domains

 - fix for the xenbus driver user interface

* tag 'for-linus-4.16a-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  pvcalls-front: wait for other operations to return when release passive sockets
  pvcalls-front: introduce a per sock_mapping refcount
  x86/xen: Calculate __max_logical_packages on PV domains
  xenbus: track caller request id

Passive sockets can have ongoing operations on them, specifically, we
have two wait_event_interruptable calls in pvcalls_front_accept.

Add two wake_up calls in pvcalls_front_release, then wait for the
potential waiters to return and release the sock_mapping refcount.
Signed-off-by: NStefano Stabellini <stefano@aporeto.com>
Acked-by: NJuergen Gross <jgross@suse.com>
Signed-off-by: NJuergen Gross <jgross@suse.com>

Introduce a per sock_mapping refcount, in addition to the existing
global refcount. Thanks to the sock_mapping refcount, we can safely wait
for it to be 1 in pvcalls_front_release before freeing an active socket,
instead of waiting for the global refcount to be 1.
Signed-off-by: NStefano Stabellini <stefano@aporeto.com>
Acked-by: NJuergen Gross <jgross@suse.com>
Signed-off-by: NJuergen Gross <jgross@suse.com>

The kernel panics on PV domains because native_smp_cpus_done() is
only called for HVM domains.

Calculate __max_logical_packages for PV domains.

Fixes: b4c0a732 ("x86/smpboot: Fix __max_logical_packages estimate")
Signed-off-by: NPrarit Bhargava <prarit@redhat.com>
Tested-and-reported-by: NSimon Gaiser <simon@invisiblethingslab.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Dou Liyang <douly.fnst@cn.fujitsu.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: xen-devel@lists.xenproject.org
Reviewed-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: NJuergen Gross <jgross@suse.com>

Commit fd8aa909 ("xen: optimize xenbus driver for multiple concurrent
xenstore accesses") optimized xenbus concurrent accesses but in doing so
broke UABI of /dev/xen/xenbus. Through /dev/xen/xenbus applications are in
charge of xenbus message exchange with the correct header and body. Now,
after the mentioned commit the replies received by application will no
longer have the header req_id echoed back as it was on request (see
specification below for reference), because that particular field is being
overwritten by kernel.

struct xsd_sockmsg
{
  uint32_t type;  /* XS_??? */
  uint32_t req_id;/* Request identifier, echoed in daemon's response.  */
  uint32_t tx_id; /* Transaction id (0 if not related to a transaction). */
  uint32_t len;   /* Length of data following this. */

  /* Generally followed by nul-terminated string(s). */
};

Before there was only one request at a time so req_id could simply be
forwarded back and forth. To allow simultaneous requests we need a
different req_id for each message thus kernel keeps a monotonic increasing
counter for this field and is written on every request irrespective of
userspace value.

Forwarding again the req_id on userspace requests is not a solution because
we would open the possibility of userspace-generated req_id colliding with
kernel ones. So this patch instead takes another route which is to
artificially keep user req_id while keeping the xenbus logic as is. We do
that by saving the original req_id before xs_send(), use the private kernel
counter as req_id and then once reply comes and was validated, we restore
back the original req_id.

Cc: <stable@vger.kernel.org> # 4.11
Fixes: fd8aa909 ("xen: optimize xenbus driver for multiple concurrent xenstore accesses")
Reported-by: NBhavesh Davda <bhavesh.davda@oracle.com>
Signed-off-by: NJoao Martins <joao.m.martins@oracle.com>
Reviewed-by: NJuergen Gross <jgross@suse.com>
Signed-off-by: NJuergen Gross <jgross@suse.com>

Sparse makes a fair bit of noise about our MPIDR mask being implicitly
long - let's explicitly describe it as such rather than just relying on
the value forcing automatic promotion.
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

Pull dma-mapping fixes from Christoph Hellwig:
 "A few dma-mapping fixes for the fallout from the changes in rc1"

* tag 'dma-mapping-4.16-2' of git://git.infradead.org/users/hch/dma-mapping:
  powerpc/macio: set a proper dma_coherent_mask
  dma-mapping: fix a comment typo
  dma-direct: comment the dma_direct_free calling convention
  dma-direct: mark as is_phys
  ia64: fix build failure with CONFIG_SWIOTLB

In many cases, page tables can be accessed concurrently by either another
CPU (due to things like fast gup) or by the hardware page table walker
itself, which may set access/dirty bits. In such cases, it is important
to use READ_ONCE/WRITE_ONCE when accessing page table entries so that
entries cannot be torn, merged or subject to apparent loss of coherence
due to compiler transformations.

Whilst there are some scenarios where this cannot happen (e.g. pinned
kernel mappings for the linear region), the overhead of using READ_ONCE
/WRITE_ONCE everywhere is minimal and makes the code an awful lot easier
to reason about. This patch consistently uses these macros in the arch
code, as well as explicitly namespacing pointers to page table entries
from the entries themselves by using adopting a 'p' suffix for the former
(as is sometimes used elsewhere in the kernel source).
Tested-by: NYury Norov <ynorov@caviumnetworks.com>
Tested-by: NRichard Ruigrok <rruigrok@codeaurora.org>
Reviewed-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

We get a warning about some slow configurations in randconfig kernels:

  mm/memory.c:83:2: error: #warning Unfortunate NUMA and NUMA Balancing config, growing page-frame for last_cpupid. [-Werror=cpp]

The warning is reasonable by itself, but gets in the way of randconfig
build testing, so I'm hiding it whenever CONFIG_COMPILE_TEST is set.

The warning was added in 2013 in commit 75980e97 ("mm: fold
page->_last_nid into page->flags where possible").

Cc: stable@vger.kernel.org
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull MIPS fixes from James Hogan:
 "A few fixes for outstanding MIPS issues:

   - an __init section mismatch warning when brcmstb_pm is enabled

   - a regression handling multiple mem=X@Y arguments (4.11)

   - a USB Kconfig select warning, and related sparc cleanup (4.16)"

* tag 'mips_fixes_4.16_2' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/mips:
  sparc,leon: Select USB_UHCI_BIG_ENDIAN_{MMIO,DESC}
  usb: Move USB_UHCI_BIG_ENDIAN_* out of USB_SUPPORT
  MIPS: Fix incorrect mem=X@Y handling
  MIPS: BMIPS: Fix section mismatch warning

Pull btrfs fixes from David Sterba:
 "We have a few assorted fixes, some of them show up during fstests so I
  gave them more testing"

* tag 'for-4.16-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: Fix use-after-free when cleaning up fs_devs with a single stale device
  Btrfs: fix null pointer dereference when replacing missing device
  btrfs: remove spurious WARN_ON(ref->count < 0) in find_parent_nodes
  btrfs: Ignore errors from btrfs_qgroup_trace_extent_post
  Btrfs: fix unexpected -EEXIST when creating new inode
  Btrfs: fix use-after-free on root->orphan_block_rsv
  Btrfs: fix btrfs_evict_inode to handle abnormal inodes correctly
  Btrfs: fix extent state leak from tree log
  Btrfs: fix crash due to not cleaning up tree log block's dirty bits
  Btrfs: fix deadlock in run_delalloc_nocow

Merge tag 'for-4.16/dm-chained-bios-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fix from Mike Snitzer:
 "Fix for DM core to properly propagate errors (avoids overriding
  non-zero error with 0). This is particularly important given DM core's
  increased use of chained bios"

* tag 'for-4.16/dm-chained-bios-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm: correctly handle chained bios in dec_pending()

Pull x86 platform driver fixes from Andy Shevchenko:

 - regression fix in keyboard support for Dell laptops

 - prevent out-of-boundary write in WMI bus driver

 - increase timeout to read functional key status on Lenovo laptops

* tag 'platform-drivers-x86-v4.16-4' of git://git.infradead.org/linux-platform-drivers-x86:
  platform/x86: dell-laptop: Removed duplicates in DMI whitelist
  platform/x86: dell-laptop: fix kbd_get_state's request value
  platform/x86: ideapad-laptop: Increase timeout to wait for EC answer
  platform/x86: wmi: fix off-by-one write in wmi_dev_probe()

Pull sound fixes from Takashi Iwai:
 "A collection of usual suspects:

   - a handful USB-audio and HD-audio device-specific quirks

   - some trivial fixes for the new AC97 bus stuff

   - another race fix in ALSA sequencer core"

* tag 'sound-4.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hda/realtek: PCI quirk for Fujitsu U7x7
  ALSA: seq: Fix racy pool initializations
  ALSA: usb: add more device quirks for USB DSD devices
  ALSA: usb-audio: Fix UAC2 get_ctl request with a RANGE attribute
  ALSA: ac97: Fix copy and paste typo in documentation
  ALSA: usb-audio: add implicit fb quirk for Behringer UFX1204
  ALSA: ac97: kconfig: Remove select of undefined symbol AC97
  ALSA: hda/realtek - Enable Thinkpad Dock device for ALC298 platform
  ALSA: hda/realtek - Add headset mode support for Dell laptop
  ALSA: hda - Fix headset mic detection problem for two Dell machines

Pull drm fixes from Dave Airlie:
 "One nouveau regression fix, one AMD quirk and a full set of i915
  fixes.

  The i915 fixes are mostly for things caught by their CI system, main
  ones being DSI panel fixes and GEM fixes"

* tag 'drm-fixes-for-v4.16-rc2' of git://people.freedesktop.org/~airlied/linux:
  drm/nouveau: Make clock gate support conditional
  drm/i915: Fix DSI panels with v1 MIPI sequences without a DEASSERT sequence v3
  drm/i915: Free memdup-ed DSI VBT data structures on driver_unload
  drm/i915: Add intel_bios_cleanup() function
  drm/i915/vlv: Add cdclk workaround for DSI
  drm/i915/gvt: fix one typo of render_mmio trace
  drm/i915/gvt: Support BAR0 8-byte reads/writes
  drm/i915/gvt: add 0xe4f0 into gen9 render list
  drm/i915/pmu: Fix building without CONFIG_PM
  drm/i915/pmu: Fix sleep under atomic in RC6 readout
  drm/i915/pmu: Fix PMU enable vs execlists tasklet race
  drm/i915: Lock out execlist tasklet while peeking inside for busy-stats
  drm/i915/breadcrumbs: Ignore unsubmitted signalers
  drm/i915: Don't wake the device up to check if the engine is asleep
  drm/i915: Avoid truncation before clamping userspace's priority value
  drm/i915/perf: Fix compiler warning for string truncation
  drm/i915/perf: Fix compiler warning for string truncation
  drm/amdgpu: add new device to use atpx quirk

dec_pending() is given an error status (possibly 0) to be recorded
against a bio.  It can be called several times on the one 'struct
dm_io', and it is careful to only assign a non-zero error to
io->status.  However when it then assigned io->status to bio->bi_status,
it is not careful and could overwrite a genuine error status with 0.

This can happen when chained bios are in use.  If a bio is chained
beneath the bio that this dm_io is handling, the child bio might
complete and set bio->bi_status before the dm_io completes.

This has been possible since chained bios were introduced in 3.14, and
has become a lot easier to trigger with commit 18a25da8 ("dm: ensure
bio submission follows a depth-first tree walk") as that commit caused
dm to start using chained bios itself.

A particular failure mode is that if a bio spans an 'error' target and a
working target, the 'error' fragment will complete instantly and set the
->bi_status, and the other fragment will normally complete a little
later, and will clear ->bi_status.

The fix is simply to only assign io_error to bio->bi_status when
io_error is not zero.
Reported-and-tested-by: NMilan Broz <gmazyland@gmail.com>
Cc: stable@vger.kernel.org (v3.14+)
Signed-off-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NMike Snitzer <snitzer@redhat.com>

Some versions of QEMU will produce an ibm,dynamic-reconfiguration-memory
node with a ibm,dynamic-memory property that is zero-filled. This
causes the drmem code to oops trying to parse this property.

The fix for this is to validate that the property does contain LMB
entries before trying to parse it and bail if the count is zero.

  Oops: Kernel access of bad area, sig: 11 [#1]
  DAR: 0000000000000010
  NIP read_drconf_v1_cell+0x54/0x9c
  LR  read_drconf_v1_cell+0x48/0x9c
  Call Trace:
    __param_initcall_debug+0x0/0x28 (unreliable)
    drmem_init+0x144/0x2f8
    do_one_initcall+0x64/0x1d0
    kernel_init_freeable+0x298/0x38c
    kernel_init+0x24/0x160
    ret_from_kernel_thread+0x5c/0xb4

The ibm,dynamic-reconfiguration-memory device tree property generated
that causes this:

  ibm,dynamic-reconfiguration-memory {
          ibm,lmb-size = <0x0 0x10000000>;
          ibm,memory-flags-mask = <0xff>;
          ibm,dynamic-memory = <0x0 0x0 0x0 0x0 0x0 0x0>;
          linux,phandle = <0x7e57eed8>;
          ibm,associativity-lookup-arrays = <0x1 0x4 0x0 0x0 0x0 0x0>;
          ibm,memory-preservation-time = <0x0>;
  };
Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Reviewed-by: NCyril Bur <cyrilbur@gmail.com>
Tested-by: NDaniel Black <daniel@linux.vnet.ibm.com>
[mpe: Trim oops report]
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

single fix for older gpus.

* 'linux-4.16' of git://github.com/skeggsb/linux:
  drm/nouveau: Make clock gate support conditional

The recently introduced clock gate support breaks on Tegra chips because
no thermal support is enabled for those devices. Conditionalize the code
on the existence of thermal support to fix this.

Fixes: b138eca6 ("drm/nouveau: Add support for basic clockgating on Kepler1")
Cc: Martin Peres <martin.peres@free.fr>
Cc: Lyude Paul <lyude@redhat.com>
Signed-off-by: NThierry Reding <treding@nvidia.com>
Reviewed-by: NLyude Paul <lyude@redhat.com>
Signed-off-by: NBen Skeggs <bskeggs@redhat.com>

Merge tag 'drm-intel-fixes-2018-02-14-1' of git://anongit.freedesktop.org/drm/drm-intel into drm-fixes

There are important fixes for VLV with MIPI/DSI panels,
2 clean-up patches needed for this MIPI/DSI fix,
and many fixes for GEM including fixes for Perf OA and PMU,
and fixes on scheduler and preemption.

This also includes GVT fixes: "This has one to fix GTT mmio 8b
access from guest and two simple ones for mmio switch and typo fix"

* tag 'drm-intel-fixes-2018-02-14-1' of git://anongit.freedesktop.org/drm/drm-intel:
  drm/i915: Fix DSI panels with v1 MIPI sequences without a DEASSERT sequence v3
  drm/i915: Free memdup-ed DSI VBT data structures on driver_unload
  drm/i915: Add intel_bios_cleanup() function
  drm/i915/vlv: Add cdclk workaround for DSI
  drm/i915/gvt: fix one typo of render_mmio trace
  drm/i915/gvt: Support BAR0 8-byte reads/writes
  drm/i915/gvt: add 0xe4f0 into gen9 render list
  drm/i915/pmu: Fix building without CONFIG_PM
  drm/i915/pmu: Fix sleep under atomic in RC6 readout
  drm/i915/pmu: Fix PMU enable vs execlists tasklet race
  drm/i915: Lock out execlist tasklet while peeking inside for busy-stats
  drm/i915/breadcrumbs: Ignore unsubmitted signalers
  drm/i915: Don't wake the device up to check if the engine is asleep
  drm/i915: Avoid truncation before clamping userspace's priority value
  drm/i915/perf: Fix compiler warning for string truncation
  drm/i915/perf: Fix compiler warning for string truncation

single atpx fix

* 'drm-next-4.16' of git://people.freedesktop.org/~agd5f/linux:
  drm/amdgpu: add new device to use atpx quirk

Pull ACPI fixes from Rafael Wysocki:
 "These fix a system resume regression from the 4.13 cycle, clean up
  device table handling in the ACPI core, update sysfs ABI documentation
  of a couple of drivers and add an expected switch fall-through marker
  to the SPCR table parsing code.

  Specifics:

   - Revert a problematic EC driver change from the 4.13 cycle that
     introduced a system resume regression on Thinkpad X240 (Rafael
     Wysocki).

   - Clean up device tables handling in the ACPI core and the related
     part of the device properties framework (Andy Shevchenko).

   - Update the sysfs ABI documentatio of the dock and the INT3407
     special device drivers (Aishwarya Pant).

   - Add an expected switch fall-through marker to the SPCR table
     parsing code (Gustavo Silva)"

* tag 'acpi-4.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI: dock: document sysfs interface
  ACPI / DPTF: Document dptf_power sysfs atttributes
  device property: Constify device_get_match_data()
  ACPI / bus: Rename acpi_get_match_data() to acpi_device_get_match_data()
  ACPI / bus: Remove checks in acpi_get_match_data()
  ACPI / bus: Do not traverse through non-existed device table
  ACPI: SPCR: Mark expected switch fall-through in acpi_parse_spcr
  ACPI / EC: Restore polling during noirq suspend/resume phases