checkpatch: Function's opening brace has to be at the
beginning of the next line.
Signed-off-by: Roman Kiryanov <rkir@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

goldfish_pipe is distributed under GPL v2.
Signed-off-by: Roman Kiryanov <rkir@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Some comment lines are longer than 80 symbols.
Signed-off-by: Roman Kiryanov <rkir@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

In preparation to remove the node name pointer from struct device_node,
convert printf users to use the %pOFn format specifier.

Cc: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The structure gsmi_dev is local to the source and does not need to be
in global scope, so make it static.

Cleans up sparse warning:
symbol 'gsmi_dev' was not declared. Should it be static?
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

put_device will call vme_dev_release to free vdev, kfree is
unnecessary here.
Signed-off-by: Ding Xiang <dingxiang@cmss.chinamobile.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This allows the context manager to retrieve information about nodes
that it holds a reference to, such as the current number of
references to those nodes.

Such information can for example be used to determine whether the
servicemanager is the only process holding a reference to a node.
This information can then be passed on to the process holding the
node, which can in turn decide whether it wants to shut down to
reduce resource usage.
Signed-off-by: Martijn Coenen <maco@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Binder uses internal fs interfaces to allocate and install fds:

__alloc_fd
__fd_install
__close_fd
get_files_struct
put_files_struct

These were used to support the passing of fds between processes
as part of a transaction. The actual allocation and installation
of the fds in the target process was handled by the sending
process so the standard functions, alloc_fd() and fd_install()
which assume task==current couldn't be used.

This patch refactors this mechanism so that the fds are
allocated and installed by the target process allowing the
standard functions to be used.

The sender now creates a list of fd fixups that contains the
struct *file and the address to fixup with the new fd once
it is allocated. This list is processed by the target process
when the transaction is dequeued.

A new error case is introduced by this change. If an async
transaction with file descriptors cannot allocate new
fds in the target (probably due to out of file descriptors),
the transaction is discarded with a log message. In the old
implementation this would have been detected in the sender
context and failed prior to sending.
Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

When a process dies, failed reply is sent to the sender of any transaction
queued on a dead thread's todo list. The sender asserts that the
received failed reply corresponds to the head of the transaction stack.
This assert can fail if the dead thread is allowed to send outgoing
transactions when there is already a transaction on its todo list,
because this new transaction can end up on the transaction stack of the
original sender. The following steps illustrate how this assertion can
fail.

1. Thread1 sends txn19 to Thread2
   (T1->transaction_stack=txn19, T2->todo+=txn19)
2. Without processing todo list, Thread2 sends txn20 to Thread1
   (T1->todo+=txn20, T2->transaction_stack=txn20)
3. T1 processes txn20 on its todo list
   (T1->transaction_stack=txn20->txn19, T1->todo=<empty>)
4. T2 dies, T2->todo cleanup attempts to send failed reply for txn19, but
   T1->transaction_stack points to txn20 -- assertion failes

Step 2. is the incorrect behavior. When there is a transaction on a
thread's todo list, this thread should not be able to send any outgoing
synchronous transactions. Only the head of the todo list needs to be
checked because only threads that are waiting for proc work can directly
receive work from another thread, and no work is allowed to be queued
on such a thread without waking up the thread. This patch also enforces
that a thread is not waiting for proc work when a work is directly
enqueued to its todo list.
Acked-by: Arve Hjønnevåg <arve@android.com>
Signed-off-by: Sherry Yang <sherryy@android.com>
Reviewed-by: Martijn Coenen <maco@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

As part of commit 9b85e95a ("uio: Change return
type to vm_fault_t") in 4.19-rc1, this conversion
was missed. Now converted 'ret' to vm_fault_t type.
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

In preparation to remove the node name pointer from struct device_node,
convert printf users to use the %pOFn format specifier.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

nvmem_device_get() should return ERR_PTR() on error or valid pointer
on success, but one of the code path seems to return NULL, so fix it.
Reported-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Resolved "ERROR: do not initialise statics to 0"
Signed-off-by: Parth Y Shah <sparth1292@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Array prox_curr_ma is declared but never used, hence it is redundant
and can be removed.

Cleans up clang warning:
warning: 'prox_curr_ma' defined but not used [-Wunused-const-variable=]
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Array ir_currents is declared but never used, hence it is redundant
and can be removed.

Cleans up clang warning:
warning: 'ir_currents' defined but not used [-Wunused-const-variable=]
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

When both uio and the uio drivers are built in the kernel, it is possible
for a driver to register devices before the uio class is registered.

This may result in a NULL pointer dereference later on in
get_device_parent() when accessing the class glue_dirs spinlock.

The trace looks like that:

Unable to handle kernel NULL pointer dereference at virtual address 00000140
[...]
[<ffff0000089cc234>] _raw_spin_lock+0x14/0x48
[<ffff0000084f56bc>] device_add+0x154/0x6a0
[<ffff0000084f5e48>] device_create_groups_vargs+0x120/0x128
[<ffff0000084f5edc>] device_create+0x54/0x60
[<ffff0000086e72c0>] __uio_register_device+0x120/0x4a8
[<ffff000008528b7c>] jaguar2_pci_probe+0x2d4/0x558
[<ffff0000083fc18c>] local_pci_probe+0x3c/0xb8
[<ffff0000083fd81c>] pci_device_probe+0x11c/0x180
[<ffff0000084f88bc>] driver_probe_device+0x22c/0x2d8
[<ffff0000084f8a24>] __driver_attach+0xbc/0xc0
[<ffff0000084f69fc>] bus_for_each_dev+0x4c/0x98
[<ffff0000084f81b8>] driver_attach+0x20/0x28
[<ffff0000084f7d08>] bus_add_driver+0x1b8/0x228
[<ffff0000084f93c0>] driver_register+0x60/0xf8
[<ffff0000083fb918>] __pci_register_driver+0x40/0x48

Return EPROBE_DEFER in that case so the driver can register the device
later.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

If hv_synic_alloc() errors out, the state of the per-cpu context
for some CPUs is unknown since the zero'ing is done as each
CPU is iterated over.  In such case, hv_synic_cleanup() may try to
free memory based on uninitialized values.  Fix this by zero'ing
the per-cpu context for all CPUs before doing any memory
allocations that might fail.
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

DEBUG is leftover from the development phase, remove it.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

When using DPDK there is significant performance boost by using
the largest possible send and receive buffer area.

Unfortunately, with UIO model there is not a good way to configure
this at run time. But it is okay to have a bigger buffer available
even if application only decides to use a smaller piece of it.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Add support for overriding the default driver for a VMBus device
in the same way that it can be done for PCI devices. This patch
adds the /sys/bus/vmbus/devices/.../driver_override file
and the logic for matching.

This is used by driverctl tool to do driver override.
https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgitlab.com%2Fdriverctl%2Fdriverctl&amp;data=02%7C01%7Ckys%40microsoft.com%7C42e803feb2c544ef6ea908d5fd538878%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636693457619960040&amp;sdata=kEyYHRIjNZCk%2B37moCSqbrZL426YccNQrsWpENcrZdw%3D&amp;reserved=0Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Trivial fix to two spelling mistakes
"execeeded" -> "exceeded"
"Invaild" -> "Invalid"
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Alan Tull <atull@kernel.org>
Acked-by: Moritz Fischer <mdf@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Pull x86 fixes from Thomas Gleixner:
 "A set of fixes for x86:

   - Prevent multiplication result truncation on 32bit. Introduced with
     the early timestamp reworrk.

   - Ensure microcode revision storage to be consistent under all
     circumstances

   - Prevent write tearing of PTEs

   - Prevent confusion of user and kernel reegisters when dumping fatal
     signals verbosely

   - Make an error return value in a failure path of the vector
     allocation negative. Returning EINVAL might the caller assume
     success and causes further wreckage.

   - A trivial kernel doc warning fix"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm: Use WRITE_ONCE() when setting PTEs
  x86/apic/vector: Make error return value negative
  x86/process: Don't mix user/kernel regs in 64bit __show_regs()
  x86/tsc: Prevent result truncation on 32bit
  x86: Fix kernel-doc atomic.h warnings
  x86/microcode: Update the new microcode revision unconditionally
  x86/microcode: Make sure boot_cpu_data.microcode is up-to-date

Pull timekeeping fixes from Thomas Gleixner:
 "Two fixes for timekeeping:

   - Revert to the previous kthread based update, which is unfortunately
     required due to lock ordering issues. The removal caused boot
     failures on old Core2 machines. Add a proper comment why the thread
     needs to stay to prevent accidental removal in the future.

   - Fix a silly typo in a function declaration"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clocksource: Revert "Remove kthread"
  timekeeping: Fix declaration of read_persistent_wall_and_boot_offset()

Pull irqchip fix from Thomas Gleixner:
 "A single fix to prevent allocating excessive memory in the GIC/ITS
  driver.

  While the subject of the patch might suggest otherwise this is a real
  fix as some SoCs exceed the memory allocation limits and fail to boot"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/gic-v3-its: Cap lpi_id_bits to reduce memory footprint

Pull cpu hotplug fixes from Thomas Gleixner:
 "Two fixes for the hotplug state machine code:

   - Move the misplaces smb() in the hotplug thread function to the
     proper place, otherwise a half update control struct could be
     observed

   - Prevent state corruption on error rollback, which causes the state
     to advance by one and as a consequence skip it in the bringup
     sequence"

* 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  cpu/hotplug: Prevent state corruption on error rollback
  cpu/hotplug: Adjust misplaced smb() in cpuhp_thread_fun()

Pull random driver fix from Ted Ts'o:
 "Fix things so the choice of whether or not to trust RDRAND to
  initialize the CRNG is configurable via the boot option
  random.trust_cpu={on,off}"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random:
  random: make CPU trust a boot parameter

Merge tag 'kbuild-fixes-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild fixes from Masahiro Yamada:

 - make setlocalversion more robust about -dirty check

 - loosen the pkg-config requirement for Kconfig

 - change missing depmod to a warning from an error

 - warn modules_install when System.map is missing

* tag 'kbuild-fixes-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kbuild: modules_install: warn when missing System.map file
  kbuild: make missing $DEPMOD a Warning instead of an Error
  kconfig: do not require pkg-config on make {menu,n}config
  kconfig: remove a spurious self-assignment
  scripts/setlocalversion: git: Make -dirty check more robust

If there is no System.map file for "make modules_install",
scripts/depmod.sh will silently exit with success, having done
nothing.  Since this is an unexpected situation, change it to
report a Warning for the missing file.  The behavior is not
changed except for the Warning message.

The (previous) silent success and new Warning can be reproduced
by:
$ make mrproper; make defconfig
$ make modules; make modules_install

and since System.map is produced by "make vmlinux", the steps
above omit producing the System.map file.
Reported-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

Pull KVM fixes from Radim Krčmář:
 "ARM:
   - Fix a VFP corruption in 32-bit guest
   - Add missing cache invalidation for CoW pages
   - Two small cleanups

  s390:
   - Fallout from the hugetlbfs support: pfmf interpretion and locking
   - VSIE: fix keywrapping for nested guests

  PPC:
   - Fix a bug where pages might not get marked dirty, causing guest
     memory corruption on migration
   - Fix a bug causing reads from guest memory to use the wrong guest
     real address for very large HPT guests (>256G of memory), leading
     to failures in instruction emulation.

  x86:
   - Fix out of bound access from malicious pv ipi hypercalls
     (introduced in rc1)
   - Fix delivery of pending interrupts when entering a nested guest,
     preventing arbitrarily late injection
   - Sanitize kvm_stat output after destroying a guest
   - Fix infinite loop when emulating a nested guest page fault and
     improve the surrounding emulation code
   - Two minor cleanups"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (28 commits)
  KVM: LAPIC: Fix pv ipis out-of-bounds access
  KVM: nVMX: Fix loss of pending IRQ/NMI before entering L2
  arm64: KVM: Remove pgd_lock
  KVM: Remove obsolete kvm_unmap_hva notifier backend
  arm64: KVM: Only force FPEXC32_EL2.EN if trapping FPSIMD
  KVM: arm/arm64: Clean dcache to PoC when changing PTE due to CoW
  KVM: s390: Properly lock mm context allow_gmap_hpage_1m setting
  KVM: s390: vsie: copy wrapping keys to right place
  KVM: s390: Fix pfmf and conditional skey emulation
  tools/kvm_stat: re-animate display of dead guests
  tools/kvm_stat: indicate dead guests as such
  tools/kvm_stat: handle guest removals more gracefully
  tools/kvm_stat: don't reset stats when setting PID filter for debugfs
  tools/kvm_stat: fix updates for dead guests
  tools/kvm_stat: fix handling of invalid paths in debugfs provider
  tools/kvm_stat: fix python3 issues
  KVM: x86: Unexport x86_emulate_instruction()
  KVM: x86: Rename emulate_instruction() to kvm_emulate_instruction()
  KVM: x86: Do not re-{try,execute} after failed emulation in L2
  KVM: x86: Default to not allowing emulation retry in kvm_mmu_page_fault
  ...

Pull ARM SoC fixes from Olof Johansson:
 "A few more fixes who have trickled in:

   - MMC bus width fixup for some Allwinner platforms

   - Fix for NULL deref in ti-aemif when no platform data is passed in

   - Fix div by 0 in SCMI code

   - Add a missing module alias in a new RPi driver"

* tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  memory: ti-aemif: fix a potential NULL-pointer dereference
  firmware: arm_scmi: fix divide by zero when sustained_perf_level is zero
  hwmon: rpi: add module alias to raspberrypi-hwmon
  arm64: allwinner: dts: h6: fix Pine H64 MMC bus width

Merge tag 'sunxi-fixes-for-4.19' of https://git.kernel.org/pub/scm/linux/kernel/git/sunxi/linux into fixes

Allwinner fixes for 4.19

Just one fix for H6 mmc on the Pine H64: the mmc bus width was missing
from the device tree. This was added in 4.19-rc1.

* tag 'sunxi-fixes-for-4.19' of https://git.kernel.org/pub/scm/linux/kernel/git/sunxi/linux:
  arm64: allwinner: dts: h6: fix Pine H64 MMC bus width
Signed-off-by: Olof Johansson <olof@lixom.net>

When page-table entries are set, the compiler might optimize their
assignment by using multiple instructions to set the PTE. This might
turn into a security hazard if the user somehow manages to use the
interim PTE. L1TF does not make our lives easier, making even an interim
non-present PTE a security hazard.

Using WRITE_ONCE() to set PTEs and friends should prevent this potential
security hazard.

I skimmed the differences in the binary with and without this patch. The
differences are (obviously) greater when CONFIG_PARAVIRT=n as more
code optimizations are possible. For better and worse, the impact on the
binary with this patch is pretty small. Skimming the code did not cause
anything to jump out as a security hazard, but it seems that at least
move_soft_dirty_pte() caused set_pte_at() to use multiple writes.
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180902181451.80520-1-namit@vmware.com

activate_managed() returns EINVAL instead of -EINVAL in case of
error. While this is unlikely to happen, the positive return value would
cause further malfunction at the call site.

Fixes: 2db1f959 ("x86/vector: Handle managed interrupts proper")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org

Pull i2c fixes from Wolfram Sang:

 - bugfixes for uniphier, i801, and xiic drivers

 - ID removal (never produced) for imx

 - one MAINTAINER addition

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: xiic: Record xilinx i2c with Zynq fragment
  i2c: xiic: Make the start and the byte count write atomic
  i2c: i801: fix DNV's SMBCTRL register offset
  i2c: imx-lpi2c: Remove mx8dv compatible entry
  dt-bindings: imx-lpi2c: Remove mx8dv compatible entry
  i2c: uniphier-f: issue STOP only for last message or I2C_M_STOP
  i2c: uniphier: issue STOP only for last message or I2C_M_STOP

Pull ARC updates from Vineet Gupta:

 - Fix for atomic_fetch_#op  [Will Deacon]

 - Enable per device IOC [Eugeniy Paltsev]

 - Remove redundant gcc version checks [Masahiro Yamada]

 - Miscll platform config/DT updates [Alexey Brodkin]

* tag 'arc-4.19-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARC: don't check for HIGHMEM pages in arch_dma_alloc
  ARC: IOC: panic if both IOC and ZONE_HIGHMEM enabled
  ARC: dma [IOC] Enable per device io coherency
  ARC: dma [IOC]: mark DMA devices connected as dma-coherent
  ARC: atomics: unbork atomic_fetch_##op()
  arc: remove redundant GCC version checks
  ARC: sort Kconfig
  ARC: cleanup show_faulting_vma()
  ARC: [plat-axs*]: Enable SWAP
  ARC: [plat-axs*/plat-hsdk]: Allow U-Boot to pass MAC-address to the kernel
  ARC: configs: cleanup

Fix the cell specification mechanism to allow cells to be pre-created
without having to specify at least one address (the addresses will be
upcalled for).

This allows the cell information preload service to avoid the need to issue
loads of DNS lookups during boot to get the addresses for each cell (500+
lookups for the 'standard' cell list[*]).  The lookups can be done later as
each cell is accessed through the filesystem.

Also remove the print statement that prints a line every time a new cell is
added.

[*] There are 144 cells in the list.  Each cell is first looked up for an
    SRV record, and if that fails, for an AFSDB record.  These get a list
    of server names, each of which then has to be looked up to get the
    addresses for that server.  E.g.:

	dig srv _afs3-vlserver._udp.grand.central.org
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull MD fixes from Shaohua Li:

 - Fix a locking issue for md-cluster (Guoqing)

 - Fix a sync crash for raid10 (Ni)

 - Fix a reshape bug with raid5 cache enabled (me)

* tag 'md/4.19-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md:
  md-cluster: release RESYNC lock after the last resync message
  RAID10 BUG_ON in raise_barrier when force is true and conf->barrier is 0
  md/raid5-cache: disable reshape completely

Pull ceph fixes from Ilya Dryomov:
 "Two rbd patches to complete support for images within namespaces that
  went into -rc1 and a use-after-free fix.

  The rbd changes have been sitting in a branch for quite a while but
  couldn't be included into the -rc1 pull request because of a pending
  wire protocol backwards compatibility fixup that only got committed
  early this week"

* tag 'ceph-for-4.19-rc3' of https://github.com/ceph/ceph-client:
  rbd: support cloning across namespaces
  rbd: factor out get_parent_info()
  ceph: avoid a use-after-free in ceph_destroy_options()