If cgroup writeback is in use, inodes can be scheduled for
asynchronous wb switching.  Before 5ff8eaac ("writeback: keep
superblock pinned during cgroup writeback association switches"), this
could race with umount leading to super_block being destroyed while
inodes are pinned for wb switching.  5ff8eaac fixed it by bumping
s_active while wb switches are in flight; however, this allowed
in-flight wb switches to make umounts asynchronous when the userland
expected synchronosity - e.g. fsck immediately following umount may
fail because the device is still busy.

This patch removes the problematic super_block pinning and instead
makes generic_shutdown_super() flush in-flight wb switches.  wb
switches are now executed on a dedicated isw_wq so that they can be
flushed and isw_nr_in_flight keeps track of the number of in-flight wb
switches so that flushing can be avoided in most cases.

v2: Move cgroup_writeback_umount() further below and add MS_ACTIVE
    check in inode_switch_wbs() as Jan an Al suggested.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Tahsin Erdogan <tahsin@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Link: http://lkml.kernel.org/g/CAAeU0aNCq7LGODvVGRU-oU_o-6enii5ey0p1c26D1ZzYwkDc5A@mail.gmail.com
Fixes: 5ff8eaac ("writeback: keep superblock pinned during cgroup writeback association switches")
Cc: stable@vger.kernel.org #v4.5
Reviewed-by: Jan Kara <jack@suse.cz>
Tested-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

A user could send a passthrough IO command with a metadata pointer to a
namespace without metadata. With metadata length of 0, kmalloc returns
ZERO_SIZE_PTR. Since that is not NULL, the driver would have set this as
the bio's integrity payload, which causes an access fault on completion.

This patch ignores the users metadata buffer if the namespace format
does not support separate metadata.
Reported-by: Stephen Bates <stephen.bates@microsemi.com>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

The command flags can change the meaning of other fields in the command
that the driver is not prepared to handle. Specifically, the user could
passthrough an SGL flag, causing the controller to misinterpret the PRP
list the driver created, potentially corrupting memory or data.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Jon Derrick <jonathan.derrick@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

This moves failed queue handling out of the namespace removal path and
into the reset failure path, fixing a hanging condition if the controller
fails or link down during del_gendisk. Previously the driver had to see
the controller as degraded prior to calling del_gendisk to setup the
queues to fail. But, if the controller happened to fail after this,
there was no task to end outstanding requests.

On failure, all namespace states are set to dead. This has capacity
revalidate to 0, and ends all new requests with error status.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

A reset failure schedules the device to unbind from the driver through
the pci driver's remove. This cleans up all intialization, so there is
no need to duplicate the potentially racy cleanup.

To help understand why a reset failed, the status is logged with the
existing warning message.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

This patch makes nvme namespace removal lockless. It is up to the caller
to ensure no active namespace scanning is occuring. To ensure no scan
work occurs, the nvme pci driver adds a removing state to the controller
device to avoid queueing scan work during removal. The work is flushed
after setting the state, so no new scan work can be queued.

The lockless removal allows the driver to cleanup a namespace
request_queue if the controller fails during removal. Previously this
could deadlock trying to acquire the namespace mutex in order to handle
such events.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

A namespace may be detached from a controller, but a user may be holding
a reference to it. Attaching a new namespace with the same NSID will create
duplicate names when using the NSID to name the disk.

This patch uses an IDA that is released only when the last reference is
released instead of using the namespace ID.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

Unmapping the registers on reset or shutdown is not necessary. Keeping
the mapping simplifies reset handling.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

This patch applies the two introduced helpers to
figure out the 1st and last bvec.
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

This patch applies the two introduced helpers to
figure out the 1st and last bvec, and fixes the
original way after bio splitting.

Cc: stable@vger.kernel.org
Reported-by: Sagi Grimberg <sagig@dev.mellanox.co.il>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

In the following patch, the way for figuring out
the last bvec will be changed with a bit cost introduced,
so return immediately if the queue doesn't have virt
boundary limit. Actually most of devices have not
this limit.
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

The bio passed to bio_will_gap() may be fast cloned from upper
layer(dm, md, bcache, fs, ...), or from bio splitting in block
core.

Unfortunately bio_will_gap() just figures out the last bvec via
'bi_io_vec[prev->bi_vcnt - 1]' directly, and this way is obviously
wrong.

This patch introduces two helpers for getting the first and last
bvec of one bio for fixing the issue.

Cc: stable@vger.kernel.org
Reported-by: Sagi Grimberg <sagig@dev.mellanox.co.il>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

Pull PCI fixes from Bjorn Helgaas:
 "Freescale Layerscape host bridge driver:
    Fix MSG TLP drop setting (Minghuan Lian)

  TI Keystone host bridge driver:
    Fix MSI code that retrieves struct pcie_port pointer (Murali Karicheri)"

* tag 'pci-v4.5-fixes-4' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  PCI: layerscape: Fix MSG TLP drop setting
  PCI: keystone: Fix MSI code that retrieves struct pcie_port pointer

Pull KVM fixes from Paolo Bonzini:
 - ARM/MIPS: Fixes for ioctls when copy_from_user returns nonzero
 - x86: Small fix for Skylake TSC scaling
 - x86: Improved fix for last week's missed hardware breakpoint bug

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  kvm: x86: Update tsc multiplier on change.
  mips/kvm: fix ioctl error handling
  arm/arm64: KVM: Fix ioctl error handling
  KVM: x86: fix root cause for missed hardware breakpoints

Pull late GPIO fix from Linus Walleij:
 "Regressions never arrive when you want them to, so here is a late fix
  for the Renesas RCAR GPIO driver.  It only affects that driver on the
  very specific Renesas platforms:

   - Fix a runtime PM suspend/resume bug in the RCAR driver"

* tag 'gpio-v4.5-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
  gpio: rcar: Add Runtime PM handling for interrupts

Pull IOMMU fixes from Joerg Roedel:
 "One fix for Intel VT-d:

   - Use BUS_NOTIFY_REMOVED_DEVICE notifier to unbind a device from its
     domain _after_ it has been unbound from its driver.  This fixes a
     BUG_ON being triggered in the PCI hotplug path.

  And three for AMD IOMMU:

   - Add a workaround for a hardware issue with ATS in use

   - Fix ATS enable/disable balance when a device is removed

   - Fix a boot warning being triggered when the system has IOMMU
     performance counters and PCI device 00:00.0 is not covered by the
     IOMMU"

* tag 'iommu-fixes-v4.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu/vt-d: Use BUS_NOTIFY_REMOVED_DEVICE in hotplug path
  iommu/amd: Detach device from domain before removal
  iommu/amd: Apply workaround for ATS write permission check
  iommu/amd: Fix boot warning when device 00:00.0 is not iommu covered

Pull minor virtio/vhost fixes from Michael Tsirkin:
 "This fixes two minor bugs: error handling in vhost, and capability
  processing in virtio"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  vhost: fix error path in vhost_init_used()
  virtio-pci: read the right virtio_pci_notify_cap field

Pull VFIO fix from Alex Williamson:
 "Use -EFAULT for copy_to_user error in ioctl (Michael Tsirkin)"

* tag 'vfio-v4.5-rc7' of git://github.com/awilliam/linux-vfio:
  vfio: fix ioctl error handling

Pull fbdev fix from Tomi Valkeinen:
 "Fix hang caused by fbconsole blink timer"

* tag 'fbdev-fixes-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tomba/linux:
  fbcon: set a default value to blink interval

Pull parisc fixes from Helge Deller:
 "We wire up the copy_file_range syscall, fix two bugs in the parisc
  ptrace code and have a trivial fix for floppy.h to clarify an
  expression with parentheses"

* 'parisc-4.5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Wire up copy_file_range syscall
  parisc: Fix ptrace syscall number and return value modification
  parisc: Use parentheses around expression in floppy.h

Pull cifs fixes from Steve French:
 "Various small CIFS/SMB3 fixes for stable:

  Fixes address oops that can occur when accessing Macs with SMB3, and
  another problem found to Samba when read responses queued (e.g. with
  gluster under Samba)"

* 'for-next' of git://git.samba.org/sfrench/cifs-2.6:
  CIFS: Fix duplicate line introduced by clone_file_range patch
  Fix cifs_uniqueid_to_ino_t() function for s390x
  CIFS: Fix SMB2+ interim response processing for read requests
  cifs: fix out-of-bounds access in lease parsing

The exit path will do some final updates to the VM of an exiting process
to inform others of the fact that the process is going away.

That happens, for example, for robust futex state cleanup, but also if
the parent has asked for a TID update when the process exits (we clear
the child tid field in user space).

However, at the time we do those final VM accesses, we've already
stopped accepting signals, so the usual "stop waiting for userfaults on
signal" code in fs/userfaultfd.c no longer works, and the process can
become an unkillable zombie waiting for something that will never
happen.

To solve this, just make handle_userfault() abort any user fault
handling if we're already in the exit path past the signal handling
state being dead (marked by PF_EXITING).

This VM special case is pretty ugly, and it is possible that we should
look at finalizing signals later (or move the VM final accesses
earlier).  But in the meantime this is a fairly minimally intrusive fix.
Reported-and-tested-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

We don't want side effects. If something fails, we rollback vq->is_le to
its previous value.
Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

Looks like a copy-paste bug. The value is used as an optimization and a
wrong value probably isn't causing any serious damage. Found when
porting this code to Windows.
Signed-off-by: Ladi Prosek <lprosek@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

vmx.c writes the TSC_MULTIPLIER field in vmx_vcpu_load, but only when a
vcpu has migrated physical cpus. Record the last value written and
update in vmx_vcpu_load on any change, otherwise a cpu migration must
occur for TSC frequency scaling to take effect.

Cc: stable@vger.kernel.org
Fixes: ff2c3a18Signed-off-by: Owen Hofmann <osh@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Returning directly whatever copy_to_user(...) or copy_from_user(...)
returns may not do the right thing if there's a pagefault:
copy_to_user/copy_from_user return the number of bytes not copied in
this case, but ioctls need to return -EFAULT instead.

Fix up kvm on mips to do
	return copy_to_user(...)) ?  -EFAULT : 0;
and
	return copy_from_user(...)) ?  -EFAULT : 0;

everywhere.

Cc: stable@vger.kernel.org
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Merge tag 'kvm-arm-for-4.5-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-master

KVM/ARM fixes for 4.5-rc7

- Fix ioctl error handling on the timer path

Pull d_inode/d_flags race fix from Al Viro.

I love this fix.  Not only does it fix the race in the dentry type
handling, it entirely gets rid of the nasty and subtle memory ordering
rules for d_type and d_inode, and replaces them with the basic dentry
locking rules (sequence numbers under RCU, d_lock elsewhere).

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  use ->d_seq to get coherency between ->d_inode and ->d_flags

Signed-off-by: Helge Deller <deller@gmx.de>

Mike Frysinger reported that his ptrace testcase showed strange
behaviour on parisc: It was not possible to avoid a syscall and the
return value of a syscall couldn't be changed.

To modify a syscall number, we were missing to save the new syscall
number to gr20 which is then picked up later in assembly again.

The effect that the return value couldn't be changed is a side-effect of
another bug in the assembly code. When a process is ptraced, userspace
expects each syscall to report entrance and exit of a syscall.  If a
syscall number was given which doesn't exist, we jumped to the normal
syscall exit code instead of informing userspace that the (non-existant)
syscall exits. This unexpected behaviour confuses userspace and thus the
bug was misinterpreted as if we can't change the return value.

This patch fixes both problems and was tested on 64bit kernel with
32bit userspace.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: stable@vger.kernel.org  # v4.0+
Tested-by: Mike Frysinger <vapier@gentoo.org>

David Binderman reported a style issue in the floppy.h header file:
arch/parisc/include/asm/floppy.h:221: (style) Boolean result is used in bitwise
  operation. Clarify expression with parentheses.
Reported-by: David Binderman <dcb314@hotmail.com>
Cc: David Binderman <dcb314@hotmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>

Pull sparc fixes from David Miller:

 1) System call tracing doesn't handle register contents properly across
    the trace.  From Mike Frysinger.

 2) Hook up copy_file_range

 3) Build fix for 32-bit with newer tools.

 4) New sun4v watchdog driver, from Wim Coekaerts.

 5) Set context system call has to allow for servicable faults when we
    flush the register windows to memory

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  sparc64: Fix sparc64_set_context stack handling.
  sparc32: Add -Wa,-Av8 to KBUILD_CFLAGS.
  Add sun4v_wdt watchdog driver
  sparc: Fix system call tracing register handling.
  sparc: Hook up copy_file_range syscall.

Commit 04b38d60 ("vfs: pull btrfs clone API to vfs layer")
added a duplicated line (in cifsfs.c) which causes a sparse compile
warning.
Signed-off-by: Steve French <steve.french@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

Like a signal return, we should use synchronize_user_stack() rather
than flush_user_windows().
Reported-by: Ilya Malakhov <ilmalakhovthefirst@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Binutils used to be (erroneously) extremely permissive about
instruction usage.  But that got fixed and if you don't properly tell
it to accept classes of instructions it will fail.

This uncovered a specs bug on sparc in gcc where it wouldn't pass the
proper options to binutils options.

Deal with this in the kernel build by adding -Wa,-Av8 to KBUILD_CFLAGS.
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

Some kinds of Layerscape PCIe controllers will forward the received message
TLPs to system application address space, which could corrupt system memory
or lead to a system hang.  Enable MSG_DROP to fix this issue.
Signed-off-by: Minghuan Lian <Minghuan.Lian@nxp.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Commit cbce7900 ("PCI: designware: Make driver arch-agnostic") changed
the host bridge sysdata pointer from the ARM pci_sys_data to the DesignWare
pcie_port structure, and changed pcie-designware.c to reflect that.  But it
did not change the corresponding code in pci-keystone-dw.c, so it caused
crashes on Keystone:

  Unable to handle kernel NULL pointer dereference at virtual address 00000030
  pgd = c0003000
  [00000030] *pgd=80000800004003, *pmd=00000000
  Internal error: Oops: 206 [#1] PREEMPT SMP ARM
  CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.4.2-00139-gb74f926 #2
  Hardware name: Keystone
  PC is at ks_dw_pcie_msi_irq_unmask+0x24/0x58

Change pci-keystone-dw.c to expect sysdata to be the struct pcie_port
pointer.

[bhelgaas: changelog]
Fixes: cbce7900 ("PCI: designware: Make driver arch-agnostic")
Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: stable@vger.kernel.org	# v4.4+
CC: Zhou Wang <wangzhou1@hisilicon.com>

In the PCI hotplug path of the Intel IOMMU driver, replace
the usage of the BUS_NOTIFY_DEL_DEVICE notifier, which is
executed before the driver is unbound from the device, with
BUS_NOTIFY_REMOVED_DEVICE, which runs after that.

This fixes a kernel BUG being triggered in the VT-d code
when the device driver tries to unmap DMA buffers and the
VT-d driver already destroyed all mappings.
Reported-by: Stefani Seibold <stefani@seibold.net>
Cc: stable@vger.kernel.org # v4.3+
Signed-off-by: Joerg Roedel <jroedel@suse.de>

Games with ordering and barriers are way too brittle.  Just
bump ->d_seq before and after updating ->d_inode and ->d_flags
type bits, so that verifying ->d_seq would guarantee they are
coherent.

Cc: stable@vger.kernel.org # v3.13+
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Detach the device that is about to be removed from its
domain (if it has one) to clear any related state like DTE
entry and device's ATS state.
Reported-by: Kelly Zytaruk <Kelly.Zytaruk@amd.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>