We have observed a BUG() crash in fs/attr.c:notify_change(). The crash
occurs during an rsync into a filesystem that is exported via NFS.

1.) fs/attr.c:notify_change() modifies the caller's version of attr.
2.) 6de0ec00 ("VFS: make notify_change pass ATTR_KILL_S*ID to
    setattr operations") introduced a BUG() restriction such that "no
    function will ever call notify_change() with both ATTR_MODE and
    ATTR_KILL_S*ID set". Under some circumstances though, it will have
    assisted in setting the caller's version of attr to this very
    combination.
3.) 27ac0ffe ("locks: break delegations on any attribute
    modification") introduced code to handle breaking
    delegations. This can result in notify_change() being re-called. attr
    _must_ be explicitly reset to avoid triggering the BUG() established
    in #2.
4.) The path that that triggers this is via fs/open.c:chmod_common().
    The combination of attr flags set here and in the first call to
    notify_change() along with a later failed break_deleg_wait()
    results in notify_change() being called again via retry_deleg
    without resetting attr.

Solution is to move retry_deleg in chmod_common() a bit further up to
ensure attr is completely reset.

There are other places where this seemingly could occur, such as
fs/utimes.c:utimes_common(), but the attr flags are not initially
set in such a way to trigger this.

Fixes: 27ac0ffe ("locks: break delegations on any attribute modification")
Reported-by: NEric Meddaugh <etmsys@rit.edu>
Tested-by: NEric Meddaugh <etmsys@rit.edu>
Signed-off-by: NAndrew Elble <aweits@rit.edu>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

On a distributed filesystem it's possible for lookup to discover that a
directory it just found is already cached elsewhere in the directory
heirarchy.  The dcache won't let us keep the directory in both places,
so we have to move the dentry to the new location from the place we
previously had it cached.

If the parent has changed, then this requires all the same locks as we'd
need to do a cross-directory rename.  But we're already in lookup
holding one parent's i_mutex, so it's too late to acquire those locks in
the right order.

The (unreliable) solution in __d_unalias is to trylock() the required
locks and return -EBUSY if it fails.

I see no particular reason for returning -EBUSY, and -ESTALE is already
the result of some other lookup races on NFS.  I think -ESTALE is the
more helpful error return.  It also allows us to take advantage of the
logic Jeff Layton added in c6a94284 "vfs: fix renameat to retry on
ESTALE errors" and ancestors, which hopefully resolves some of these
errors before they're returned to userspace.

I can reproduce these cases using NFS with:

	ssh root@$client '
		mount -olookupcache=pos '$server':'$export' /mnt/
		mkdir /mnt/TO
		mkdir /mnt/DIR
		touch /mnt/DIR/test.txt
		while true; do
			strace -e open cat /mnt/DIR/test.txt 2>&1 | grep EBUSY
		done
	'
	ssh root@$server '
		while true; do
			mv $export/DIR $export/TO/DIR
			mv $export/TO/DIR $export/DIR
		done
	'

It also helps to add some other concurrent use of the directory on the
client (e.g., "ls /mnt/TO").  And you can replace the server-side mv's
by client-side mv's that are repeatedly killed.  (If the client is
interrupted while waiting for the RENAME response then it's left with a
dentry that has to go under one parent or the other, but it doesn't yet
know which.)
Acked-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAnton Altaparmakov <anton@tuxera.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

simillar to iov_iter_fault_in_readable() but differs in that it is
not limited to faulting in the first iovec and instead faults in
"bytes" bytes iterating over the iovecs as necessary.

Also, instead of only faulting in the first and last page of the
range, all pages are faulted in.

This function is needed by NTFS when it does multi page file
writes.
Signed-off-by: NAnton Altaparmakov <anton@tuxera.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

For one thing, LOOKUP_DIRECTORY will be dealt with in do_last().
For another, name can be an empty string, but not NULL - no callers
pass that and it would oops immediately if they would.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

flush_old_exec() has already done that.  Back on 2011 a bunch of
instances like that had been kicked out, but that hadn't taken
care of then-out-of-tree architectures, obviously, and they served
as reinfection vector...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

just make const char iname[] the last member and compare name->name with
name->iname instead of checking name->separate

We need to make sure that out-of-line name doesn't end up allocated adjacent
to struct filename refering to it; fortunately, it's easy to achieve - just
allocate that struct filename with one byte in ->iname[], so that ->iname[0]
will be inside the same object and thus have an address different from that
of out-of-line name [spotted by Boqun Feng <boqun.feng@gmail.com>]
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

struct kiocb now is a generic I/O container, so move it to fs.h.
Also do a #include diet for aio.h while we're at it.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

all callers were passing it ->name of some struct filename
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Pull networking fixes from David Miller:

 1) Validate iov ranges before feeding them into iov_iter_init(), from
    Al Viro.

 2) We changed copy_from_msghdr_from_user() to zero out the msg_namelen
    is a NULL pointer is given for the msg_name.  Do the same in the
    compat code too.  From Catalin Marinas.

 3) Fix partially initialized tuples in netfilter conntrack helper, from
    Ian Wilson.

 4) Missing continue; statement in nft_hash walker can lead to crashes,
    from Herbert Xu.

 5) tproxy_tg6_check looks for IP6T_INV_PROTO in ->flags instead of
    ->invflags, fix from Pablo Neira Ayuso.

 6) Incorrect memory account of TCP FINs can result in negative socket
    memory accounting values.  Fix from Josh Hunt.

 7) Don't allow virtual functions to enable VLAN promiscuous mode in
    be2net driver, from Vasundhara Volam.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  netfilter: nft_compat: set IP6T_F_PROTO flag if protocol is set
  cx82310_eth: wait for firmware to become ready
  net: validate the range we feed to iov_iter_init() in sys_sendto/sys_recvfrom
  net: compat: Update get_compat_msghdr() to match copy_msghdr_from_user() behaviour
  be2net: use PCI MMIO read instead of config read for errors
  be2net: restrict MODIFY_EQ_DELAY cmd to a max of 8 EQs
  be2net: Prevent VFs from enabling VLAN promiscuous mode
  tcp: fix tcp fin memory accounting
  ipv6: fix backtracking for throw routes
  net: ethernet: pcnet32: Setup the SRAM and NOUFLO on Am79C97{3, 5}
  ipv6: call ipv6_proxy_select_ident instead of ipv6_select_ident in udp6_ufo_fragment
  netfilter: xt_TPROXY: fix invflags check in tproxy_tg6_check()
  netfilter: restore rule tracing via nfnetlink_log
  netfilter: nf_tables: allow to change chain policy without hook if it exists
  netfilter: Fix potential crash in nft_hash walker
  netfilter: Zero the tuple in nfnl_cthelper_parse_tuple()

Pull sparc fixes from David Miller:
 "Some perf bug fixes from David Ahern, and the fix for that nasty
  memmove() bug"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  sparc64: Fix several bugs in memmove().
  sparc: Touch NMI watchdog when walking cpus and calling printk
  sparc: perf: Add support M7 processor
  sparc: perf: Make counting mode actually work
  sparc: perf: Remove redundant perf_pmu_{en|dis}able calls

Firstly, handle zero length calls properly.  Believe it or not there
are a few of these happening during early boot.

Next, we can't just drop to a memcpy() call in the forward copy case
where dst <= src.  The reason is that the cache initializing stores
used in the Niagara memcpy() implementations can end up clearing out
cache lines before we've sourced their original contents completely.

For example, considering NG4memcpy, the main unrolled loop begins like
this:

     load   src + 0x00
     load   src + 0x08
     load   src + 0x10
     load   src + 0x18
     load   src + 0x20
     store  dst + 0x00

Assume dst is 64 byte aligned and let's say that dst is src - 8 for
this memcpy() call.  That store at the end there is the one to the
first line in the cache line, thus clearing the whole line, which thus
clobbers "src + 0x28" before it even gets loaded.

To avoid this, just fall through to a simple copy only mildly
optimized for the case where src and dst are 8 byte aligned and the
length is a multiple of 8 as well.  We could get fancy and call
GENmemcpy() but this is good enough for how this thing is actually
used.
Reported-by: NDavid Ahern <david.ahern@oracle.com>
Reported-by: NBob Picco <bpicco@meloft.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pull bugfix for md from Neil Brown:
 "One fix for md in 4.0-rc4

  Regression in recent patch causes crash on error path"

* tag 'md/4.0-rc4-fix' of git://neil.brown.name/md:
  md: fix problems with freeing private data after ->run failure.

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for your net tree,
they are:

1) Fix missing initialization of tuple structure in nfnetlink_cthelper
   to avoid mismatches when looking up to attach userspace helpers to
   flows, from Ian Wilson.

2) Fix potential crash in nft_hash when we hit -EAGAIN in
   nft_hash_walk(), from Herbert Xu.

3) We don't need to indicate the hook information to update the
   basechain default policy in nf_tables.

4) Restore tracing over nfnetlink_log due to recent rework to
   accomodate logging infrastructure into nf_tables.

5) Fix wrong IP6T_INV_PROTO check in xt_TPROXY.

6) Set IP6T_F_PROTO flag in nft_compat so we can use SYNPROXY6 and
   REJECT6 from xt over nftables.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pull driver core fixes from Greg KH:
 "Here are two bugfixes for things reported.  One regression in kernfs,
  and another issue fixed in the LZ4 code that was fixed in the
  "upstream" codebase that solves a reported kernel crash

  Both have been in linux-next for a while"

* tag 'driver-core-4.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  LZ4 : fix the data abort issue
  kernfs: handle poll correctly on 'direct_read' files.

Pull char/misc fixes from Greg KH:
 "Here are three fixes for 4.0-rc5 that revert 3 PCMCIA patches that
  were merged in 4.0-rc1 that cause regressions.  So let's revert them
  for now and they will be reworked and resent sometime in the future.

  All have been tested in linux-next for a while"

* tag 'char-misc-4.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  Revert "pcmcia: add a new resource manager for non ISA systems"
  Revert "pcmcia: fix incorrect bracketing on a test"
  Revert "pcmcia: add missing include for new pci resource handler"

Pull staging driver fixes from Greg KH:
 "Here are four small staging driver fixes, all for the vt6656 and
  vt6655 drivers, that resolve some reported issues with them.

  All of these patches have been in linux next for a while"

* tag 'staging-4.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  vt6655: Fix late setting of byRFType.
  vt6655: RFbSetPower fix missing rate RATE_12M
  staging: vt6656: vnt_rf_setpower: fix missing rate RATE_12M
  staging: vt6655: vnt_tx_packet fix dma_idx selection.

Pull tty/serial driver fix from Greg KH:
 "Here's a single 8250 serial driver that fixes a reported deadlock with
  the serial console and the tty driver.

  It's been in linux-next for a while now"

* tag 'tty-4.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  serial: 8250_dw: Fix deadlock in LCR workaround

Pull USB / PHY driver fixes from Greg KH:
 "Here's a number of USB and PHY driver fixes for 4.0-rc5.

  The largest thing here is a revert of a gadget function driver patch
  that removes 500 lines of code.  Other than that, it's a number of
  reported bugs fixes and new quirk/id entries.

  All have been in linux-next for a while"

* tag 'usb-4.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (33 commits)
  usb: common: otg-fsm: only signal connect after switching to peripheral
  uas: Add US_FL_NO_ATA_1X for Initio Corporation controllers / devices
  USB: ehci-atmel: rework clk handling
  MAINTAINERS: add entry for USB OTG FSM
  usb: chipidea: otg: add a_alt_hnp_support response for B device
  phy: omap-usb2: Fix missing clk_prepare call when using old dt name
  phy: ti/omap: Fix modalias
  phy: core: Fixup return value of phy_exit when !pm_runtime_enabled
  phy: miphy28lp: Convert to devm_kcalloc and fix wrong sizof
  phy: miphy365x: Convert to devm_kcalloc and fix wrong sizeof
  phy: twl4030-usb: Remove redundant assignment for twl->linkstat
  phy: exynos5-usbdrd: Fix off-by-one valid value checking for args->args[0]
  phy: Find the right match in devm_phy_destroy()
  phy: rockchip-usb: Fixup rockchip_usb_phy_power_on failure path
  phy: ti-pipe3: Simplify ti_pipe3_dpll_wait_lock implementation
  phy: samsung-usb2: Remove NULL terminating entry from phys array
  phy: hix5hd2-sata: Check return value of platform_get_resource
  phy: exynos-dp-video: Kill exynos_dp_video_phy_pwr_isol function
  Revert "usb: gadget: zero: Add support for interrupt EP"
  Revert "xhci: Clear the host side toggle manually when endpoint is 'soft reset'"
  ...

ip6tables extensions check for this flag to restrict match/target to a
given protocol. Without this flag set, SYNPROXY6 returns an error.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Acked-by: NPatrick McHardy <kaber@trash.net>

When the device is powered up, some (older) firmware versions fail to work
properly if we send commands before the boot is complete (everything is OK
when the device is hot-plugged). The firmware indicates its ready status by
putting the link up.
Newer firmwares delay the first command so they don't suffer from this problem.
They also report the link being always up.

Wait for firmware to become ready (link up) before sending any commands and/or
data.

This also allows lowering CMD_TIMEOUT value to a reasonable time.

Tested with 4.1.0.9 (old) and 4.1.0.30 (new) firmware versions.
Signed-off-by: NOndrej Zary <linux@rainbow-software.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pull slave dmaengine fixes from Vinod Koul:
 "Four fixes for dw, pl08x, imx-sdma and at_hdmac driver.  Nothing
  unusual here, simple fixes to these drivers"

* 'fixes' of git://git.infradead.org/users/vkoul/slave-dma:
  dmaengine: pl08x: Define capabilities for generic capabilities reporting
  dmaengine: dw: append MODULE_ALIAS for platform driver
  dmaengine: imx-sdma: switch to dynamic context mode after script loaded
  dmaengine: at_hdmac: Fix calculation of the residual bytes

Pull power management and ACPI fixes from Rafael Wysocki:
 "These are fixes for recent regressions (PCI/ACPI resources and at91
  RTC locking), a stable-candidate powercap RAPL driver fix and two ARM
  cpuidle fixes (one stable-candidate too).

  Specifics:

   - Revert a recent PCI commit related to IRQ resources management that
     introduced a regression for drivers attempting to bind to devices
     whose previous drivers did not balance pci_enable_device() and
     pci_disable_device() as expected (Rafael J Wysocki).

   - Fix a deadlock in at91_rtc_interrupt() introduced by a typo in a
     recent commit related to wakeup interrupt handling (Dan Carpenter).

   - Allow the power capping RAPL (Running-Average Power Limit) driver
     to use different energy units for domains within one CPU package
     which is necessary to handle Intel Haswell EP processors correctly
     (Jacob Pan).

   - Improve the cpuidle mvebu driver's handling of Armada XP SoCs by
     updating the target residency and exit latency numbers for those
     chips (Sebastien Rannou).

   - Prevent the cpuidle mvebu driver from calling cpu_pm_enter() twice
     in a row before cpu_pm_exit() is called on the same CPU which
     breaks the core's assumptions regarding the usage of those
     functions (Gregory Clement)"

* tag 'pm+acpi-4.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  Revert "x86/PCI: Refine the way to release PCI IRQ resources"
  rtc: at91rm9200: double locking bug in at91_rtc_interrupt()
  powercap / RAPL: handle domains with different energy units
  cpuidle: mvebu: Update cpuidle thresholds for Armada XP SOCs
  cpuidle: mvebu: Fix the CPU PM notifier usage

Pull drm updates from Dave Airlie:
 "A bunch of fixes across drivers:

  radeon:
     disable two ended allocation for now, it breaks some stuff

  amdkfd:
     misc fixes

  nouveau:
     fix irq loop problem, add basic support for GM206 (new hw)

  i915:
     fix some WARNs people were seeing

  exynos:
     fix some iommu interactions causing boot failures"

* git://people.freedesktop.org/~airlied/linux:
  drm/radeon: drop ttm two ended allocation
  drm/exynos: fix the initialization order in FIMD
  drm/exynos: fix typo config name correctly.
  drm/exynos: Check for NULL dereference of crtc
  drm/exynos: IS_ERR() vs NULL bug
  drm/exynos: remove unused files
  drm/i915: Make sure the primary plane is enabled before reading out the fb state
  drm/nouveau/bios: fix i2c table parsing for dcb 4.1
  drm/nouveau/device/gm100: Basic GM206 bring up (as copy of GM204)
  drm/nouveau/device: post write to NV_PMC_BOOT_1 when flipping endian switch
  drm/nouveau/gr/gf100: fix some accidental or'ing of buffer addresses
  drm/nouveau/fifo/nv04: remove the loop from the interrupt handler
  drm/radeon: Changing number of compute pipe lines
  drm/amdkfd: Fix SDMA queue init. in non-HWS mode
  drm/amdkfd: destroy mqd when destroying kernel queue
  drm/i915: Ensure plane->state->fb stays in sync with plane->fb

Merge tag 'devicetree-fixes-for-4.0-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux

Pull more DeviceTree fixes vfom Rob Herring:

 - revert setting stdout-path as preferred console.  This caused
   regressions in PowerMACs and other systems.

 - yet another fix for stdout-path option parsing.

 - fix error path handling in of_irq_parse_one

* tag 'devicetree-fixes-for-4.0-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
  Revert "of: Fix premature bootconsole disable with 'stdout-path'"
  of: handle both '/' and ':' in path strings
  of: unittest: Add option string test case with longer path
  of/irq: Fix of_irq_parse_one() returned error codes

Pull SCSI target fixes from Nicholas Bellinger:
 "Here are current target-pending fixes for v4.0-rc5 code that have made
  their way into the queue over the last weeks.

  The fixes this round include:

   - Fix long-standing iser-target logout bug related to early
     conn_logout_comp completion, resulting in iscsi_conn use-after-tree
     OOpsen.  (Sagi + nab)

   - Fix long-standing tcm_fc bug in ft_invl_hw_context() failure
     handing for DDP hw offload.  (DanC)

   - Fix incorrect use of unprotected __transport_register_session() in
     tcm_qla2xxx + other single local se_node_acl fabrics.  (Bart)

   - Fix reference leak in target_submit_cmd() -> target_get_sess_cmd()
     for ack_kref=1 failure path.  (Bart)

   - Fix pSCSI backend ->get_device_type() statistics OOPs with
     un-configured device.  (Olaf + nab)

   - Fix virtual LUN=0 target_configure_device failure OOPs at modprobe
     time.  (Claudio + nab)

   - Fix FUA write false positive failure regression in v4.0-rc1 code.
     (Christophe Vu-Brugier + HCH)"

* git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending:
  target: do not reject FUA CDBs when write cache is enabled but emulate_write_cache is 0
  target: Fix virtual LUN=0 target_configure_device failure OOPs
  target/pscsi: Fix NULL pointer dereference in get_device_type
  tcm_fc: missing curly braces in ft_invl_hw_context()
  target: Fix reference leak in target_get_sess_cmd() error path
  loop/usb/vhost-scsi/xen-scsiback: Fix use of __transport_register_session
  tcm_qla2xxx: Fix incorrect use of __transport_register_session
  iscsi-target: Avoid early conn_logout_comp for iser connections
  Revert "iscsi-target: Avoid IN_LOGOUT failure case for iser-target"
  target: Disallow changing of WRITE cache/FUA attrs after export

Pull devicemapper fixes from Mike Snitzer:
 "A handful of stable fixes for DM:
   - fix thin target to always zero-fill reads to unprovisioned blocks
   - fix to interlock device destruction's suspend from internal
     suspends
   - fix 2 snapshot exception store handover bugs
   - fix dm-io to cope with DISCARD and WRITE_SAME capabilities changing"

* tag 'dm-4.0-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm io: deal with wandering queue limits when handling REQ_DISCARD and REQ_WRITE_SAME
  dm snapshot: suspend merging snapshot when doing exception handover
  dm snapshot: suspend origin when doing exception handover
  dm: hold suspend_lock while suspending device during device deletion
  dm thin: fix to consistently zero-fill reads to unprovisioned blocks

Pull btrfs fixes from Chris Mason:
 "Most of these are fixing extent reservation accounting, or corners
  with tree writeback during commit.

  Josef's set does add a test, which isn't strictly a fix, but it'll
  keep us from making this same mistake again"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix outstanding_extents accounting in DIO
  Btrfs: add sanity test for outstanding_extents accounting
  Btrfs: just free dummy extent buffers
  Btrfs: account merges/splits properly
  Btrfs: prepare block group cache before writing
  Btrfs: fix ASSERT(list_empty(&cur_trans->dirty_bgs_list)
  Btrfs: account for the correct number of extents for delalloc reservations
  Btrfs: fix merge delalloc logic
  Btrfs: fix comp_oper to get right order
  Btrfs: catch transaction abortion after waiting for it
  btrfs: fix sizeof format specifier in btrfs_check_super_valid()

Pull nfsd bufix from Bruce Fields:
 "This is a fix for a crash easily triggered by 4.1 activity to a server
  built with CONFIG_NFSD_PNFS.

  There are some more bugfixes queued up that I intend to pass along
  next week, but this is the most critical"

* 'for-4.0' of git://linux-nfs.org/~bfields/linux:
  Subject: nfsd: don't recursively call nfsd4_cb_layout_fail

Pull UBI fix from Artem Bityutskiy:
 "This fixes a bug introduced during the v4.0 merge window where we
  forgot to put braces where they should be"

* tag 'upstream-4.0-rc5' of git://git.infradead.org/linux-ubifs:
  UBI: fix missing brace control flow