blk-mq uses percpu_ref for its usage counter which tracks the number
of in-flight commands and used to synchronously drain the queue on
freeze.  percpu_ref shutdown takes measureable wallclock time as it
involves a sched RCU grace period.  This means that draining a blk-mq
takes measureable wallclock time.  One would think that this shouldn't
matter as queue shutdown should be a rare event which takes place
asynchronously w.r.t. userland.

Unfortunately, SCSI probing involves synchronously setting up and then
tearing down a lot of request_queues back-to-back for non-existent
LUNs.  This means that SCSI probing may take more than ten seconds
when scsi-mq is used.

This will be properly fixed by implementing a mechanism to keep
q->mq_usage_counter in atomic mode till genhd registration; however,
that involves rather big updates to percpu_ref which is difficult to
apply late in the devel cycle (v3.17-rc6 at the moment).  As a
stop-gap measure till the proper fix can be implemented in the next
cycle, this patch introduces __percpu_ref_kill_expedited() and makes
blk_mq_freeze_queue() use it.  This is heavy-handed but should work
for testing the experimental SCSI blk-mq implementation.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Christoph Hellwig <hch@infradead.org>
Link: http://lkml.kernel.org/g/20140919113815.GA10791@lst.de
Fixes: add703fd ("blk-mq: use percpu_ref for mq usage count")
Cc: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Tested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

Pull infiniband/rdma fixes from Roland Dreier:
 "Last late set of InfiniBand/RDMA fixes for 3.17:

   - fixes for the new memory region re-registration support
   - iSER initiator error path fixes
   - grab bag of small fixes for the qib and ocrdma hardware drivers
   - larger set of fixes for mlx4, especially in RoCE mode"

* tag 'rdma-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband: (26 commits)
  IB/mlx4: Fix VF mac handling in RoCE
  IB/mlx4: Do not allow APM under RoCE
  IB/mlx4: Don't update QP1 in native mode
  IB/mlx4: Avoid accessing netdevice when building RoCE qp1 header
  mlx4: Fix mlx4 reg/unreg mac to work properly with 0-mac addresses
  IB/core: When marshaling uverbs path, clear unused fields
  IB/mlx4: Avoid executing gid task when device is being removed
  IB/mlx4: Fix lockdep splat for the iboe lock
  IB/mlx4: Get upper dev addresses as RoCE GIDs when port comes up
  IB/mlx4: Reorder steps in RoCE GID table initialization
  IB/mlx4: Don't duplicate the default RoCE GID
  IB/mlx4: Avoid null pointer dereference in mlx4_ib_scan_netdevs()
  IB/iser: Bump version to 1.4.1
  IB/iser: Allow bind only when connection state is UP
  IB/iser: Fix RX/TX CQ resource leak on error flow
  RDMA/ocrdma: Use right macro in query AH
  RDMA/ocrdma: Resolve L2 address when creating user AH
  mlx4: Correct error flows in rereg_mr
  IB/qib: Correct reference counting in debugfs qp_stats
  IPoIB: Remove unnecessary port query
  ...

Pull sound fixes from Takashi Iwai:
 "One fix is about a buggy computation in PCM API function Clemens
  spotted out, but the impact must be really small as no one really uses
  it in user-space side.

  The rest are a trivial fix for a HD-audio model and a USB-audio
  device-specific regression fix, so all look fairly safe to apply"

* tag 'sound-3.17-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: snd-usb-caiaq: Fix LED commands for Kore controller
  ALSA: pcm: fix fifo_size frame calculation
  ALSA: hda - Add fixup model name lookup for Lemote A1205

Pull final block fixes from Jens Axboe:
 "This week and last we've been fixing some corner cases related to
  blk-mq, mostly.  I ended up pulling most of that out of for-linus
  yesterday, which is why the branch looks fresh.  The rest were
  postponed for 3.18.

  This pull request contains:

   - Fix from Christoph, avoiding a stack overflow when FUA insertion
     would recursive infinitely.

   - Fix from David Hildenbrand on races between the timeout handler and
     uninitialized requests.  Fixes a real issue that virtio_blk has run
     into.

   - A few fixes from me:

        - Ensure that request deadline/timeout is ordered before the
          request is marked as started.

        - A potential oops on out-of-memory, when we scale the queue
          depth of the device and retry.

        - A hang fix on requeue from SCSI, where the hardware queue
          would be stopped when we attempt to re-run it (and hence
          nothing would happen, stalling progress).

        - A fix for commit 2da78092, where the cleanup path was moved
          to RCU, but a debug might_sleep() was inadvertently left in
          the code.  This causes warnings for people"

* 'for-linus' of git://git.kernel.dk/linux-block:
  genhd: fix leftover might_sleep() in blk_free_devt()
  blk-mq: use blk_mq_start_hw_queues() when running requeue work
  blk-mq: fix potential oops on out-of-memory in __blk_mq_alloc_rq_maps()
  blk-mq: avoid infinite recursion with the FUA flag
  blk-mq: Avoid race condition with uninitialized requests
  blk-mq: request deadline must be visible before marking rq as started

Pull parisc fixes from Helge Deller:
 "We avoid using -mfast-indirect-calls for 64bit kernel builds to
  prevent building an unbootable kernel due to latest gcc changes.

  In the pdc_stable/firmware-access driver we fix a few possible stack
  overflows and we now call secure_computing_strict() instead of
  secure_computing() which fixes upcoming SECCOMP patches in the
  for-next trees"

* 'parisc-3.17-7' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Only use -mfast-indirect-calls option for 32-bit kernel builds
  parisc: pdc_stable.c: Avoid potential stack overflows
  parisc: pdc_stable.c: Cleaning up unnecessary use of memset in conjunction with strncpy
  parisc: ptrace: use secure_computing_strict()

In spite of what the GCC manual says, the -mfast-indirect-calls has
never been supported in the 64-bit parisc compiler. Indirect calls have
always been done using function descriptors irrespective of the
-mfast-indirect-calls option.

Recently, it was noticed that a function descriptor was always requested
when the -mfast-indirect-calls option was specified. This caused
problems when the option was used in  application code and doesn't make
any sense because the whole point of the option is to avoid using a
function descriptor for indirect calls.

Fixing this broke 64-bit kernel builds.

I will fix GCC but for now we need the attached change. This results in
the same kernel code as before.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org  # v3.0+
Signed-off-by: Helge Deller <deller@gmx.de>

Pull ia64 defconfig update from Tony Luck:
 "Need to rebuild defconfig files to cope with removal of "select NET"
  in drivers/scsi/Kconfig"

* tag 'please-pull-defconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux:
  [IA64] refresh arch/ia64/configs/* using "make savedefconfig"

Pull hwmon fixes from Guenter Roeck:
 - Fix a resource leak in tmp103 driver
 - Add support for two more processors to fam15h_power driver
 - Also fix a bug in the same driver to only report the power level on
   chips which actually support reporting it

* tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: (tmp103) Fix resource leak bug in tmp103 temperature sensor driver
  hwmon: (fam15h_power) Add support for two more processors
  hwmon: (fam15h_power) Make actual power reporting conditional

Prompted by a change to drivers/scsi/Kconfig which used to do a
"select NET" but now does a "depends on NET". This meant that some
configurations ended up without CONFIG_NET=y

Signed-off-by Tony Luck <tony.luck@intel.com>

Pull another kvm fix from Paolo Bonzini:
 "Another fix for 3.17 arrived at just the wrong time, after I had sent
  yesterday's pull request.  Normally I would have waited for some other
  patches to pile up, but since 3.17 might be short here it is"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  arm/arm64: KVM: Fix unaligned access bug on gicv2 access

Pull cgroup fix from Tejun Heo:
 "One late fix for cgroup.

  I was waiting for another set of fixes for a long-standing obscure
   cpuset bug but am not sure whether they'll be ready before v3.17
  release.  This one is a simple fix for a mutex unlock balance bug in
  an allocation failure path in pidlist_array_load().

  The bug was introduced in v3.14 and the fix is tagged for -stable"

* 'for-3.17-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: fix unbalanced locking

Merge tag 'kvm-arm-for-v3.17-rc7-or-final' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-master

Fixes unaligned access to the gicv2 virtual cpu status.

This reverts commit 9cb0e394.

It causes my Sony Vaio Pro 11 to immediately reboot at startup.
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Anvin <hpa@zytor.com>
Cc: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull networking fixes from David Miller:

 1) If the user gives us a msg_namelen of 0, don't try to interpret
    anything pointed to by msg_name.  From Ani Sinha.

 2) Fix some bnx2i/bnx2fc randconfig compilation errors.

    The gist of the issue is that we firstly have drivers that span both
    SCSI and networking.  And at the top of that chain of dependencies
    we have things like SCSI_FC_ATTRS and SCSI_NETLINK which are
    selected.

    But since select is a sledgehammer and ignores dependencies,
    everything to select's SCSI_FC_ATTRS and/or SCSI_NETLINK has to also
    explicitly select their dependencies and so on and so forth.

    Generally speaking 'select' is supposed to only be used for child
    nodes, those which have no dependencies of their own.  And this
    whole chain of dependencies in the scsi layer violates that rather
    strongly.

    So just make SCSI_NETLINK depend upon it's dependencies, and so on
    and so forth for the things selecting it (either directly or
    indirectly).

    From Anish Bhatt and Randy Dunlap.

 3) Fix generation of blackhole routes in IPSEC, from Steffen Klassert.

 4) Actually notice netdev feature changes in rtl_open() code, from
    Hayes Wang.

 5) Fix divide by zero in bond enslaving, from Nikolay Aleksandrov.

 6) Missing memory barrier in sunvnet driver, from David Stevens.

 7) Don't leave anycast addresses around when ipv6 interface is
    destroyed, from Sabrina Dubroca.

 8) Don't call efx_{arch}_filter_sync_rx_mode before addr_list_lock is
    initialized in SFC driver, from Edward Cree.

 9) Fix missing DMA error checking in 3c59x, from Neal Horman.

10) Openvswitch doesn't emit OVS_FLOW_CMD_NEW notifications accidently,
    fix from Samuel Gauthier.

11) pch_gbe needs to select NET_PTP_CLASSIFY otherwise we can get a
    build error.

12) Fix macvlan regression wherein we stopped emitting
    broadcast/multicast frames over software devices.  From Nicolas
    Dichtel.

13) Fix infiniband bug due to unintended overflow of skb->cb[], from
    Eric Dumazet.  And add an assertion so this doesn't happen again.

14) dm9000_parse_dt() should return error pointers, not NULL.  From
    Tobias Klauser.

15) IP tunneling code uses this_cpu_ptr() in preemptible contexts, fix
    from Eric Dumazet.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (87 commits)
  net: bcmgenet: call bcmgenet_dma_teardown in bcmgenet_fini_dma
  net: bcmgenet: fix TX reclaim accounting for fragments
  ipv4: do not use this_cpu_ptr() in preemptible context
  dm9000: Return an ERR_PTR() in all error conditions of dm9000_parse_dt()
  r8169: fix an if condition
  r8152: disable ALDPS
  ipoib: validate struct ipoib_cb size
  net: sched: shrink struct qdisc_skb_cb to 28 bytes
  tg3: Work around HW/FW limitations with vlan encapsulated frames
  macvlan: allow to enqueue broadcast pkt on virtual device
  pch_gbe: 'select' NET_PTP_CLASSIFY.
  scsi: Use 'depends' with LIBFC instead of 'select'.
  openvswitch: restore OVS_FLOW_CMD_NEW notifications
  genetlink: add function genl_has_listeners()
  lib: rhashtable: remove second linux/log2.h inclusion
  net: allow macvlans to move to net namespace
  3c59x: Fix bad offset spec in skb_frag_dma_map
  3c59x: Add dma error checking and recovery
  sparc: bpf_jit: fix support for ldx/stx mem and SKF_AD_VLAN_TAG
  can: at91_can: add missing prepare and unprepare of the clock
  ...

Pull clock layer fixes from Mike Turquette:
 "The fixes for the clock tree are mostly run-time bugs in clock
  drivers.

  The fixes for TI DRA7 remove divide-by-zero errors.  The recently
  merged AT91 clock driver fixes some bad error checking and the QCOM
  driver fix restores audio for that platform, a clear regression.  A
  list iteration bug in the framework core was hit recently and is fixed
  up here.  Finally a compilation warning is fixed for efm32gg, which is
  also a regression fix"

* tag 'clk-fixes-for-linus' of git://git.linaro.org/people/mike.turquette/linux:
  clk/efm32gg: fix dt init prototype
  clk: prevent erronous parsing of children during rate change
  clk: rockchip: Fix the clocks for i2c1 and i2c2
  clk: qcom: Fix sdc 144kHz frequency entry
  clk: at91: fix num_parents test in at91sam9260 slow clk implementation
  clk: ti: dra7-atl: Provide error check for incoming parameters in set_rate
  clk: ti: divider: Provide error check for incoming parameters in set_rate

Merge tag 'fscache-fixes-20140917' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

Pull fs-cache fixes from David Howells:

 - Put a timeout in releasepage() to deal with a recursive hang between
   the memory allocator, writeback, ext4 and fscache under memory
   pressure.

 - Fix a pair of refcount bugs in the fscache error handling.

 - Remove a couple of unused pagevecs.

 - The cachefiles requirement that the base directory support rename
   should permit rename2 as an alternative - otherwise certain
   filesystems cannot now be used as backing stores (such as ext4).

* tag 'fscache-fixes-20140917' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  CacheFiles: Handle rename2
  cachefiles: remove two unused pagevecs.
  FS-Cache: refcount becomes corrupt under vma pressure.
  FS-Cache: Reduce cookie ref count if submit fails.
  FS-Cache: Timeout for releasepage()

Florian Fainelli says:

====================
net: bcmgenet: TX reclaim and DMA fixes

This patch set contains one fix for an accounting problem while reclaiming
transmitted buffers having fragments, and the second fix is to make sure
that the DMA shutdown is properly controlled.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

We should not be manipulaging the DMA_CTRL registers directly by writing
0 to them to disable DMA. This is an operation that needs to be timed to
make sure the DMA engines have been properly stopped since their state
machine stops on a packet boundary, not immediately.

Make sure that tha bcmgenet_fini_dma() calls bcmgenet_dma_teardown() to
ensure a proper DMA engine state. As a result, we need to reorder the
function bodies to resolve the use dependency.

Fixes: 1c1008c7 ("net: bcmgenet: add main driver file")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The GENET driver supports SKB fragments, and succeeds in transmitting
them properly, but when reclaiming these transmitted fragments, we will
only update the count of free buffer descriptors by 1, even for SKBs
with fragments. This leads to the networking stack thinking it has more
room than the hardware has when pushing new SKBs, and backing off
consequently because we return NETDEV_TX_BUSY.

Fix this by accounting for the SKB nr_frags plus one (itself) and update
ring->free_bds accordingly with that value for each iteration loop in
__bcmgenet_tx_reclaim().

Fixes: 1c1008c7 ("net: bcmgenet: add main driver file")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

this_cpu_ptr() in preemptible context is generally bad

Sep 22 05:05:55 br kernel: [   94.608310] BUG: using smp_processor_id()
in
preemptible [00000000] code: ip/2261
Sep 22 05:05:55 br kernel: [   94.608316] caller is
tunnel_dst_set.isra.28+0x20/0x60 [ip_tunnel]
Sep 22 05:05:55 br kernel: [   94.608319] CPU: 3 PID: 2261 Comm: ip Not
tainted
3.17.0-rc5 #82

We can simply use raw_cpu_ptr(), as preemption is safe in these
contexts.

Should fix https://bugzilla.kernel.org/show_bug.cgi?id=84991Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Joe <joe9mail@gmail.com>
Fixes: 9a4aa9af ("ipv4: Use percpu Cache route in IP tunnels")
Acked-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We were using an atomic bitop on the vgic_v2.vgic_elrsr field which was
not aligned to the natural size on 64-bit platforms.  This bug showed up
after QEMU correctly identifies the pl011 line as being level-triggered,
and not edge-triggered.

These data structures are protected by a spinlock so simply use a
non-atomic version of the accessor instead.
Tested-by: Joel Schopp <joel.schopp@amd.com>
Reported-by: Riku Voipio <riku.voipio@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

Commit 2da78092 changed the locking from a mutex to a spinlock,
so we now longer sleep in this context. But there was a leftover
might_sleep() in there, which now triggers since we do the final
free from an RCU callback. Get rid of it.
Reported-by: Pontus Fuchs <pontus.fuchs@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

Steffen Klassert says:

====================
pull request (net): ipsec 2014-09-22

We generate a blackhole or queueing route if a packet
matches an IPsec policy but a state can't be resolved.
Here we assume that dst_output() is called to kill
these packets. Unfortunately this assumption is not
true in all cases, so it is possible that these packets
leave the system without the necessary transformations.

This pull request contains two patches to fix this issue:

1) Fix for blackhole routed packets.

2) Fix for queue routed packets.

Both patches are serious stable candidates.

Please pull or let me know if there are problems.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

In one error condition dm9000_parse_dt() returns NULL, however the
return value is checked using IS_ERR() in dm9000_probe(), leading to the
error not being properly propagated if CONFIG_OF is not enabled or the
device tree data is not available. Fix this by also returning an
ERR_PTR() in this case.

Fixes: 0b8bf1ba (net: dm9000: Allow instantiation using device tree)
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

There is an extra semi-colon so __rtl8169_set_features() is called every
time.

Fixes: 929a031d ('r8169: adjust __rtl8169_set_features')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Hayes Wang <hayeswang@realtek.com>--
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull KVM fixes from Paolo Bonzini:
 "Two very simple bugfixes, affecting all supported architectures"

[ Two? There's three commits in here.  Oh well, I guess Paolo didn't
  count the preparatory symbol export ]

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: correct null pid check in kvm_vcpu_yield_to()
  KVM: check for !is_zero_pfn() in kvm_is_mmio_pfn()
  mm: export symbol dependencies of is_zero_pfn()

If the hw is in ALDPS mode, the hw may have no response for accessing
the most registers. Therefore, the ALDPS should be disabled before
accessing the hw in rtl_ops.init(), rtl_ops.disable(), rtl_ops.up(),
and rtl_ops.down(). Regardless of rtl_ops.enable(), because the hw
wouldn't enter ALDPS mode when linking on. The hw would enter the
ALDPS mode after several seconds when link down occurs and the ALDPS
is enabled.
Signed-off-by: Hayes Wang <hayeswang@realtek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

To catch future errors sooner.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We cannot make struct qdisc_skb_cb bigger without impacting IPoIB,
or increasing skb->cb[] size.

Commit e0f31d84 ("flow_keys: Record IP layer protocol in
skb_flow_dissect()") broke IPoIB.

Only current offender is sch_choke, and this one do not need an
absolutely precise flow key.

If we store 17 bytes of flow key, its more than enough. (Its the actual
size of flow_keys if it was a packed structure, but we might add new
fields at the end of it later)
Signed-off-by: Eric Dumazet <edumazet@google.com>
Fixes: e0f31d84 ("flow_keys: Record IP layer protocol in skb_flow_dissect()")
Signed-off-by: David S. Miller <davem@davemloft.net>

TG3 appears to have an issue performing TSO and checksum offloading
correclty when the frame has been vlan encapsulated (non-accelrated).
In these cases, tcp checksum is not correctly updated.

This patch attempts to work around this issue.  After the patch,
802.1ad vlans start working correctly over tg3 devices.

CC: Prashant Sreedharan <prashant@broadcom.com>
CC: Michael Chan <mchan@broadcom.com>
Signed-off-by: Vladislav Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

tmp103 temperature sensor driver registers with the hwmon framework by calling
hwmon_device_register_with_groups but does not have a .remove method to call
hwmon_device_unregister to unregister from the framework when the device is no
longer needed. Fix this by calling devm_hwmon_device_register_with_groups.
Signed-off-by: Sundar J Dev <sundarjayakumardev@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Since commit 412ca155 ("macvlan: Move broadcasts into a work queue"), the
driver uses tx_queue_len of the master device as the limit of packets enqueuing.
Problem is that virtual drivers have this value set to 0, thus all broadcast
packets were rejected.
Because tx_queue_len was arbitrarily chosen, I replace it with a static limit
of 1000 (also arbitrarily chosen).

CC: Herbert Xu <herbert@gondor.apana.org.au>
Reported-by: Thibaut Collet <thibaut.collet@6wind.com>
Suggested-by: Thibaut Collet <thibaut.collet@6wind.com>
Tested-by: Thibaut Collet <thibaut.collet@6wind.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

When requests are retried due to hw or sw resource shortages,
we often stop the associated hardware queue. So ensure that we
restart the queues when running the requeue work, otherwise the
queue run will be a no-op.
Signed-off-by: Jens Axboe <axboe@fb.com>

__blk_mq_alloc_rq_maps() can be invoked multiple times, if we scale
back the queue depth if we are low on memory. So don't clear
set->tags when we fail, this is handled directly in
the parent function, blk_mq_alloc_tag_set().
Reported-by: Robert Elliott  <Elliott@hp.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

We should not insert requests into the flush state machine from
blk_mq_insert_request.  All incoming flush requests come through
blk_{m,s}q_make_request and are handled there, while blk_execute_rq_nowait
should only be called for BLOCK_PC requests.  All other callers
deal with requests that already went through the flush statemchine
and shouldn't be reinserted into it.
Reported-by: Robert Elliott  <Elliott@hp.com>
Debugged-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

This patch should fix the bug reported in
https://lkml.org/lkml/2014/9/11/249.

We have to initialize at least the atomic_flags and the cmd_flags when
allocating storage for the requests.

Otherwise blk_mq_timeout_check() might dereference uninitialized
pointers when racing with the creation of a request.

Also move the reset of cmd_flags for the initializing code to the point
where a request is freed. So we will never end up with pending flush
request indicators that might trigger dereferences of invalid pointers
in blk_mq_timeout_check().

Cc: stable@vger.kernel.org
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Reported-by: Paulo De Rezende Pinatti <ppinatti@linux.vnet.ibm.com>
Tested-by: Paulo De Rezende Pinatti <ppinatti@linux.vnet.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

When we start the request, we set the deadline and flip the bits
marking the request as started and non-complete. However, it's
important that the deadline store is ordered before flipping the
bits, otherwise we could have a small window where the request is
marked started but with an invalid deadline. This can confuse the
timeout handling.
Suggested-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

Fixes the following randconfig build failure:

> drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c: In function
> ‘pch_ptp_match’:
> drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c:130:2: error:
> implicit declaration of function ‘ptp_classify_raw’
> [-Werror=implicit-function-declaration]
>   if (ptp_classify_raw(skb) == PTP_CLASS_NONE)
>   ^
> cc1: some warnings being treated as errors
> make[5]: *** [drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.o] Error 1
Reported-by: Jim Davis <jim.epost@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

LIBFC depends upon SCSI_FC_ATTRS and select's CRC32C.

The only alternative would be to 'select' CRC32C and all of
SCSI_FC_ATTRS direct and indirect dependencies in the Kconfig section
for every LIBFCOE user which makes little sense.

Subsequently, use 'depends' instead of 'select' for LIBFCOE too.
Signed-off-by: David S. Miller <davem@davemloft.net>