Btrfs: unset DCACHE_DISCONNECTED when mounting default subvol

A user was running into errors from an NFS export of a subvolume that had a
default subvol set.  When we mount a default subvol we will use d_obtain_alias()
to find an existing dentry for the subvolume in the case that the root subvol
has already been mounted, or a dummy one is allocated in the case that the root
subvol has not already been mounted.  This allows us to connect the dentry later
on if we wander into the path.  However if we don't ever wander into the path we
will keep DCACHE_DISCONNECTED set for a long time, which angers NFS.  It doesn't
appear to cause any problems but it is annoying nonetheless, so simply unset
DCACHE_DISCONNECTED in the get_default_root case and switch btrfs_lookup() to
use d_materialise_unique() instead which will make everything play nicely
together and reconnect stuff if we wander into the defaul subvol path from a
different way.  With this patch I'm no longer getting the NFS errors when
exporting a volume that has been mounted with a default subvol set.  Thanks,

cc: bfields@fieldses.org
cc: ebiederm@xmission.com
Signed-off-by: Josef Bacik <jbacik@fb.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Chris Mason <clm@fb.com>
cifs: ensure that uncached writes handle unmapped areas correctly

It's possible for userland to pass down an iovec via writev() that has a
bogus user pointer in it. If that happens and we're doing an uncached
write, then we can end up getting less bytes than we expect from the
call to iov_iter_copy_from_user. This is CVE-2014-0069

cifs_iovec_write isn't set up to handle that situation however. It'll
blindly keep chugging through the page array and not filling those pages
with anything useful. Worse yet, we'll later end up with a negative
number in wdata->tailsz, which will confuse the sending routines and
cause an oops at the very least.

Fix this by having the copy phase of cifs_iovec_write stop copying data
in this situation and send the last write as a short one. At the same
time, we want to avoid sending a zero-length write to the server, so
break out of the loop and set rc to -EFAULT if that happens. This also
allows us to handle the case where no address in the iovec is valid.

[Note: Marking this for stable on v3.4+ kernels, but kernels as old as
       v2.6.38 may have a similar problem and may need similar fix]

Cc: <stable@vger.kernel.org> # v3.4+
Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru>
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
CIFS: Fix too big maxBuf size for SMB3 mounts

SMB3 servers can respond with MaxTransactSize of more than 4M
that can cause a memory allocation error returned from kmalloc
in a lock codepath. Also the client doesn't support multicredit
requests now and allows buffer sizes of 65536 bytes only. Set
MaxTransactSize to this maximum supported value.

Cc: stable@vger.kernel.org # 3.7+
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Merge tag 'char-misc-3.14-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc fixes from Greg KH:
 "Here are some small char/misc driver fixes, along with some
  documentation updates, for 3.14-rc3.  Nothing major, just a number of
  fixes for reported issues"

* tag 'char-misc-3.14-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  Revert "misc: eeprom: sunxi: Add new compatibles"
  Revert "ARM: sunxi: dt: Convert to the new SID compatibles"
  misc: mic: fix possible signed underflow (undefined behavior) in userspace API
  ARM: sunxi: dt: Convert to the new SID compatibles
  misc: eeprom: sunxi: Add new compatibles
  misc: genwqe: Fix potential memory leak when pinning memory
  Documentation:Update Documentation/zh_CN/arm64/memory.txt
  Documentation:Update Documentation/zh_CN/arm64/booting.txt
  Documentation:Chinese translation of Documentation/arm64/tagged-pointers.txt
  raw: set range for MAX_RAW_DEVS
  raw: test against runtime value of max_raw_minors
  Drivers: hv: vmbus: Don't timeout during the initial connection with host
  Drivers: hv: vmbus: Specify the target CPU that should receive notification
  VME: Correct read/write alignment algorithm
  mei: don't unset read cb ptr on reset
  mei: clear write cb from waiting list on reset
Merge tag 'driver-core-3.14-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core fix from Greg KH:
 "Here is a single driver core patch for 3.14-rc3 for the component code
  that Russell has found and fixed"

* tag 'driver-core-3.14-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  drivers/base: fix devres handling for master device
Merge tag 'staging-3.14-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging

Pull staging driver fixes from Greg KH:
 "Here are a number (lots, I know) of fixes for staging drivers to
  resolve a bunch of reported issues.

  The largest patches here is one revert of a patch that is in 3.14-rc1
  to fix reported problems, and a sync of a usb host driver that
  required some ARM patches to go in before it could be accepted (which
  is why it missed -rc1)

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'staging-3.14-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (56 commits)
  staging/rtl8821ae: fix build, depends on MAC80211
  iio: max1363: Use devm_regulator_get_optional for optional regulator
  iio:accel:bma180: Use modifier instead of index in channel specification
  iio: adis16400: Set timestamp as the last element in chan_spec
  iio: ak8975: Fix calculation formula for convert micro tesla to gauss unit
  staging:iio:ad799x fix typo in ad799x_events[]
  iio: mxs-lradc: remove useless scale_available files
  iio: mxs-lradc: fix buffer overflow
  iio:magnetometer:mag3110: Fix output of decimal digits in show_int_plus_micros()
  iio:magnetometer:mag3110: Report busy in _read_raw() / write_raw() when buffer is enabled
  wlags49_h2: Fix overflow in wireless_set_essid()
  xlr_net: Fix missing trivial allocation check
  staging: r8188eu: overflow in rtw_p2p_get_go_device_address()
  staging: r8188eu: array overflow in rtw_mp_ioctl_hdl()
  staging: r8188eu: Fix typo in USB_DEVICE list
  usbip/userspace/libsrc/names.c: memory leak
  gpu: ion: dereferencing an ERR_PTR
  staging: comedi: usbduxsigma: fix unaligned dereferences
  staging: comedi: fix too early cleanup in comedi_auto_config()
  staging: android: ion: dummy: fix an error code
  ...
Merge tag 'tty-3.14-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver fixes from Greg KH:
 "Here are a small number of tty/serial driver fixes to resolve reported
  issues with 3.14-rc and earlier (in the case of the vt bugfix).  Some
  of these have been tested and reported by a number of people as the
  tty bugfix was pretty commonly hit on some platforms.

  All have been in linux-next for a while"

* tag 'tty-3.14-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  vt: Fix secure clear screen
  serial: 8250: Support XR17V35x fraction divisor
  n_tty: Fix stale echo output
  serial: sirf: fix kernel panic caused by unpaired spinlock
  serial: 8250_pci: unbreak last serial ports on NetMos 9865 cards
  n_tty: Fix poll() when TIME_CHAR and MIN_CHAR == 0
  serial: omap: fix rs485 probe on defered pinctrl
  serial: 8250_dw: fix compilation warning when !CONFIG_PM_SLEEP
  serial: omap-serial: Move info message to probe function
  tty: Set correct tty name in 'active' sysfs attribute
  tty: n_gsm: Fix for modems with brk in modem status control
  drivers/tty/hvc: don't use module_init in non-modular hyp. console code
Merge tag 'usb-3.14-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb

Pull USB fixes from Greg KH:
 "Here is a bunch of USB fixes for 3.14-rc3.  Most of these are xhci
  reverts, fixing a bunch of reported issues with USB 3 host controller
  issues that loads of people have been hitting (with the exception of
  kernel developers, all of our machines seem to be working fine, which
  is why these took so long to get resolved...)

  There are some other minor fixes and new device ids, as ususal.  All
  have been in linux-next successfully"

* tag 'usb-3.14-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (22 commits)
  usb: option: blacklist ZTE MF667 net interface
  Revert "usb: xhci: Link TRB must not occur within a USB payload burst"
  Revert "xhci: Avoid infinite loop when sg urb requires too many trbs"
  Revert "xhci: Set scatter-gather limit to avoid failed block writes."
  xhci 1.0: Limit arbitrarily-aligned scatter gather.
  Modpost: fixed USB alias generation for ranges including 0x9 and 0xA
  usb: core: Fix potential memory leak adding dyn USBdevice IDs
  USB: ftdi_sio: add Tagsys RFID Reader IDs
  usb: qcserial: add Netgear Aircard 340U
  usb-storage: enable multi-LUN scanning when needed
  USB: simple: add Dynastream ANT USB-m Stick device support
  usb-storage: add unusual-devs entry for BlackBerry 9000
  usb-storage: restrict bcdDevice range for Super Top in Cypress ATACB
  usb: phy: move some error messages to debug
  usb: ftdi_sio: add Mindstorms EV3 console adapter
  usb: dwc2: fix memory corruption in dwc2 driver
  usb: dwc2: fix role switch breakage
  usb: dwc2: bail out early when booting with "nousb"
  Revert "xhci: replace xhci_read_64() with readq()"
  Revert "xhci: replace xhci_write_64() with writeq()"
  ...
ACPI / dock: Make 'docked' sysfs attribute work as documented

After recent ACPI core changes acpi_bus_get_device() will always
succeed for dock station ACPI device objects, so show_docked()
should not use that function's return value as an indicator of
whether or not the dock device is present.

Make it use acpi_device_enumerated() for this purpose.

Fixes: 202317a573b2 (ACPI / scan: Add acpi_device objects for all device nodes in the namespace)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
i2c: mv64xxx: refactor message start to ensure proper initialization

Because the offload mechanism can fall back to a standard transfer,
having two seperate initialization states is unfortunate. Let's just
have one state which does things consistently. This fixes a bug where
some preparation was missing when the fallback happened. And it makes
the code much easier to follow. To implement this, we put the check
if offload is possible at the top of the offload setup function.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Cc: stable@vger.kernel.org # v3.12+
Fixes: 930ab3d403ae (i2c: mv64xxx: Add I2C Transaction Generator support)
btrfs: fix null pointer deference at btrfs_sysfs_add_one+0x105

bdev is null when disk has disappeared and mounted with
the degrade option

stack trace
---------
btrfs_sysfs_add_one+0x105/0x1c0 [btrfs]
open_ctree+0x15f3/0x1fe0 [btrfs]
btrfs_mount+0x5db/0x790 [btrfs]
? alloc_pages_current+0xa4/0x160
mount_fs+0x34/0x1b0
vfs_kern_mount+0x62/0xf0
do_mount+0x22e/0xa80
? __get_free_pages+0x9/0x40
? copy_mount_options+0x31/0x170
SyS_mount+0x7e/0xc0
system_call_fastpath+0x16/0x1b
---------

reproducer:
-------
mkfs.btrfs -draid1 -mraid1 /dev/sdc /dev/sdd
(detach a disk)
devmgt detach /dev/sdc [1]
mount -o degrade /dev/sdd /btrfs
-------

[1] github.com/anajain/devmgt.git

Signed-off-by: Anand Jain <Anand.Jain@oracle.com>
Tested-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
Btrfs: use right clone root offset for compressed extents

For non compressed extents, iterate_extent_inodes() gives us offsets
that take into account the data offset from the file extent items, while
for compressed extents it doesn't. Therefore we have to adjust them before
placing them in a send clone instruction. Not doing this adjustment leads to
the receiving end requesting for a wrong a file range to the clone ioctl,
which results in different file content from the one in the original send
root.

Issue reproducible with the following excerpt from the test I made for
xfstests:

  _scratch_mkfs
  _scratch_mount "-o compress-force=lzo"

  $XFS_IO_PROG -f -c "truncate 118811" $SCRATCH_MNT/foo
  $XFS_IO_PROG -c "pwrite -S 0x0d -b 39987 92267 39987" $SCRATCH_MNT/foo

  $BTRFS_UTIL_PROG subvolume snapshot -r $SCRATCH_MNT $SCRATCH_MNT/mysnap1

  $XFS_IO_PROG -c "pwrite -S 0x3e -b 80000 200000 80000" $SCRATCH_MNT/foo
  $BTRFS_UTIL_PROG filesystem sync $SCRATCH_MNT
  $XFS_IO_PROG -c "pwrite -S 0xdc -b 10000 250000 10000" $SCRATCH_MNT/foo
  $XFS_IO_PROG -c "pwrite -S 0xff -b 10000 300000 10000" $SCRATCH_MNT/foo

  # will be used for incremental send to be able to issue clone operations
  $BTRFS_UTIL_PROG subvolume snapshot -r $SCRATCH_MNT $SCRATCH_MNT/clones_snap

  $BTRFS_UTIL_PROG subvolume snapshot -r $SCRATCH_MNT $SCRATCH_MNT/mysnap2

  $FSSUM_PROG -A -f -w $tmp/1.fssum $SCRATCH_MNT/mysnap1
  $FSSUM_PROG -A -f -w $tmp/2.fssum -x $SCRATCH_MNT/mysnap2/mysnap1 \
      -x $SCRATCH_MNT/mysnap2/clones_snap $SCRATCH_MNT/mysnap2
  $FSSUM_PROG -A -f -w $tmp/clones.fssum $SCRATCH_MNT/clones_snap \
      -x $SCRATCH_MNT/clones_snap/mysnap1 -x $SCRATCH_MNT/clones_snap/mysnap2

  $BTRFS_UTIL_PROG send $SCRATCH_MNT/mysnap1 -f $tmp/1.snap
  $BTRFS_UTIL_PROG send $SCRATCH_MNT/clones_snap -f $tmp/clones.snap
  $BTRFS_UTIL_PROG send -p $SCRATCH_MNT/mysnap1 \
      -c $SCRATCH_MNT/clones_snap $SCRATCH_MNT/mysnap2 -f $tmp/2.snap

  _scratch_unmount
  _scratch_mkfs
  _scratch_mount

  $BTRFS_UTIL_PROG receive $SCRATCH_MNT -f $tmp/1.snap
  $FSSUM_PROG -r $tmp/1.fssum $SCRATCH_MNT/mysnap1 2>> $seqres.full

  $BTRFS_UTIL_PROG receive $SCRATCH_MNT -f $tmp/clones.snap
  $FSSUM_PROG -r $tmp/clones.fssum $SCRATCH_MNT/clones_snap 2>> $seqres.full

  $BTRFS_UTIL_PROG receive $SCRATCH_MNT -f $tmp/2.snap
  $FSSUM_PROG -r $tmp/2.fssum $SCRATCH_MNT/mysnap2 2>> $seqres.full

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
Documentation: i2c: describe devicetree method for instantiating devices

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Documentation: i2c: mention ACPI method for instantiating devices

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc

Pull ARM SoC fixes from Kevin Hilman:
 "A collection of ARM SoC fixes for v3.14-rc1.

  Mostly a collection of Kconfig, device tree data and compilation fixes
  along with fix to drivers/phy that fixes a boot regression on some
  Marvell mvebu platforms"

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  dma: mv_xor: Silence a bunch of LPAE-related warnings
  ARM: ux500: disable msp2 device tree node
  ARM: zynq: Reserve not DMAable space in front of the kernel
  ARM: multi_v7_defconfig: Select CONFIG_SOC_DRA7XX
  ARM: imx6: Initialize low-power mode early again
  ARM: pxa: fix various compilation problems
  ARM: pxa: fix compilation problem on AM300EPD board
  ARM: at91: add Atmel's SAMA5D3 Xplained board
  spi/atmel: document clock properties
  mmc: atmel-mci: document clock properties
  ARM: at91: enable USB host on at91sam9n12ek board
  ARM: at91/dt: fix sama5d3 ohci hclk clock reference
  ARM: at91/dt: sam9263: fix compatibility string for the I2C
  ata: sata_mv: Fix probe failures with optional phys
  drivers: phy: Add support for optional phys
  drivers: phy: Make NULL a valid phy reference
  ARM: fix HAVE_ARM_TWD selection for OMAP and shmobile
  ARM: moxart: move DMA_OF selection to driver
  ARM: hisi: fix kconfig warning on HAVE_ARM_TWD
Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 EFI fixes from Peter Anvin:
 "A few more EFI-related fixes"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/efi: Check status field to validate BGRT header
  x86/efi: Fix 32-bit fallout
Merge tag 'trace-fixes-v3.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull twi tracing fixes from Steven Rostedt:
 "Two urgent fixes in the tracing utility.

  The first is a fix for the way the ring buffer stores timestamps.
  After a restructure of the code was done, the ring buffer timestamp
  logic missed the fact that the first event on a sub buffer is to have
  a zero delta, as the full timestamp is stored on the sub buffer
  itself.  But because the delta was not cleared to zero, the timestamp
  for that event will be calculated as the real timestamp + the delta
  from the last timestamp.  This can skew the timestamps of the events
  and have them say they happened when they didn't really happen.
  That's bad.

  The second fix is for modifying the function graph caller site.  When
  the stop machine was removed from updating the function tracing code,
  it missed updating the function graph call site location.  It is still
  modified as if it is being done via stop machine.  But it's not.  This
  can lead to a GPF and kernel crash if the function graph call site
  happens to lie between cache lines and one CPU is executing it while
  another CPU is doing the update.  It would be a very hard condition to
  hit, but the result is severe enough to have it fixed ASAP"

* tag 'trace-fixes-v3.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace/x86: Use breakpoints for converting function graph caller
  ring-buffer: Fix first commit on sub-buffer having non-zero delta
Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer fixes from Thomas Gleixner:
 "The following trilogy of patches brings you:

   - fix for a long standing math overflow issue with HZ < 60

   - an onliner fix for a corner case in the dreaded tick broadcast
     mechanism affecting a certain range of AMD machines which are
     infested with the infamous automagic C1E power control misfeature

   - a fix for one of the ARM platforms which allows the kernel to
     proceed and boot instead of stupidly panicing for no good reason.
     The patch is slightly larger than necessary, but it's less ugly
     than the alternative 5 liner"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tick: Clear broadcast pending bit when switching to oneshot
  clocksource: Kona: Print warning rather than panic
  time: Fix overflow when HZ is smaller than 60
Merge branches 'irq-urgent-for-linus' and 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull irq update from Thomas Gleixner:
 "Fix from the urgent branch: a trivial oneliner adding the missing
  Kconfig dependency curing build failures which have been discovered by
  several build robots.

  The update in the irq-core branch provides a new function in the
  irq/devres code, which is a prerequisite for driver developers to get
  rid of boilerplate code all over the place.

  Not a bugfix, but it has zero impact on the current kernel due to the
  lack of users.  It's simpler to provide the infrastructure to
  interested parties via your tree than fulfilling the wishlist of
  driver maintainers on which particular commit or tag this should be
  based on"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq: Add missing irq_to_desc export for CONFIG_SPARSE_IRQ=n

* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq: Add devm_request_any_context_irq()
Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux

Pull i2c fixes from Wolfram Sang:
 "i2c has a bugfix and documentation improvements for you"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  Documentation: i2c: mention ACPI method for instantiating devices
  Documentation: i2c: describe devicetree method for instantiating devices
  i2c: mv64xxx: refactor message start to ensure proper initialization