btrfs_kobj_add_device() does not need fs_info any more.
Signed-off-by: NAnand Jain <anand.jain@oracle.com>
Signed-off-by: NDavid Sterba <dsterba@suse.cz>

Just a helper function to clean up the sysfs fsid kobjects.
Signed-off-by: NAnand Jain <anand.jain@oracle.com>
Signed-off-by: NDavid Sterba <dsterba@suse.cz>

adds fs_info pointer with struct btrfs_fs_devices.
Signed-off-by: NAnand Jain <anand.jain@oracle.com>
Signed-off-by: NDavid Sterba <dsterba@suse.cz>

Signed-off-by: NAnand Jain <anand.jain@oracle.com>
Signed-off-by: NDavid Sterba <dsterba@suse.cz>

This patch will provide a framework and help to create attributes
from the structure btrfs_fs_devices which are available even before
fs_info is created. So by moving the parent kobject super_kobj from
fs_info to btrfs_fs_devices, it will help to create attributes
from the btrfs_fs_devices as well.

Patches on top of this patch now will be able to create the
sys/fs/btrfs/fsid kobject and attributes from btrfs_fs_devices
when devices are scanned and registered to the kernel.

Just to note, this does not change any of the existing btrfs sysfs
external kobject names and its attributes and not even the life
cycle of them. Changes are internal only. And to ensure the same,
this path has been tested with various device operations and,
checking and comparing the sysfs kobjects and attributes with
sysfs kobject and attributes with out this patch, and they remain
same.
Signed-off-by: NAnand Jain <anand.jain@oracle.com>
Signed-off-by: NDavid Sterba <dsterba@suse.cz>

Separate device kobject and its attribute creation so that device
kobject can be created from the device discovery thread.
Signed-off-by: NAnand Jain <anand.jain@oracle.com>
Signed-off-by: NDavid Sterba <dsterba@suse.cz>

As of now btrfs_attrs are provided using the default_attrs through
the kset. Separate them and create the default_attrs using the
sysfs_create_files instead. By doing this we will have the
flexibility that device discovery thread could create fsid
kobject.
Signed-off-by: NAnand Jain <anand.jain@oracle.com>
Signed-off-by: NDavid Sterba <dsterba@suse.cz>

We need it in a seperate function so that it can be called from the
device discovery thread as well.
Signed-off-by: NAnand Jain <anand.jain@oracle.com>
Signed-off-by: NDavid Sterba <dsterba@suse.cz>

Signed-off-by: NAnand Jain <anand.jain@oracle.com>
Signed-off-by: NDavid Sterba <dsterba@suse.cz>

As of now the order in which the kobjects are created
at btrfs_sysfs_add_one() is..
 fsid
 features
 unknown features (dynamic features)
 devices.

Since we would move fsid and device kobject to fs_devices
from fs_info structure, this patch will reorder in which
the kobjects are created as below.
 fsid
 devices
 features
 unknown features (dynamic features)

And hence the btrfs_sysfs_remove_one() will follow the same
in reverse order. and the device kobject destroy now can
be moved into the function __btrfs_sysfs_remove_one()
Signed-off-by: NAnand Jain <anand.jain@oracle.com>
Signed-off-by: NDavid Sterba <dsterba@suse.cz>

Since the failure code in the btrfs_sysfs_add_one() can
call btrfs_sysfs_remove_one() even before device_dir_kobj
has been created we need to check if its null.
Signed-off-by: NAnand Jain <anand.jain@oracle.com>
Signed-off-by: NDavid Sterba <dsterba@suse.cz>

The sysfs clean up self test like in the below code fails, since
fs_info->device_dir_kobject still points to its stale kobject.
Reseting this pointer will help to fix this.

open_ctree()
{

ret = btrfs_sysfs_add_one(fs_info);
::
+       btrfs_sysfs_remove_one(fs_info);
+       ret = btrfs_sysfs_add_one(fs_info);
+       if (ret) {
+               pr_err("BTRFS: failed to init sysfs interface: %d\n", ret);
+               goto fail_block_groups;
+       }
Signed-off-by: NAnand Jain <anand.jain@oracle.com>
Signed-off-by: NDavid Sterba <dsterba@suse.cz>

Theoritically need to remove the device links attributes, but since its entire device
kobject was removed, so there wasn't any issue of about it. Just do it nicely.
Signed-off-by: NAnand Jain <anand.jain@oracle.com>
Signed-off-by: NDavid Sterba <dsterba@suse.cz>

kobject_unregister is to handle the release of the kobject,
its completion init is being called in btrfs_sysfs_add_one(),
so we don't have to do the same in the open_ctree() again.
Signed-off-by: NAnand Jain <anand.jain@oracle.com>
Signed-off-by: NDavid Sterba <dsterba@suse.cz>

The following test case fails indicating that, thread tried to init an initialized object.

kernel: [232104.016513] kobject (ffff880006c1c980): tried to init an initialized object, something is seriously wrong.

btrfs_sysfs_remove_one() self test code:

open_tree()
{
 ::
        ret = btrfs_sysfs_add_one(fs_info);
	if (ret) {
              pr_err("BTRFS: failed to init sysfs interface: %d\n", ret);
                goto fail_block_groups;
        }
+       btrfs_sysfs_remove_one(fs_info);
+       ret = btrfs_sysfs_add_one(fs_info);
+       if (ret) {
+               pr_err("BTRFS: failed to init sysfs interface: %d\n", ret);
+               goto fail_block_groups;
+       }

cleaning up the unregistered kobject fixes this.
Signed-off-by: NAnand Jain <anand.jain@oracle.com>
Signed-off-by: NDavid Sterba <dsterba@suse.cz>

Pull SCSI fixes from James Bottomley:
 "This is a set of five fixes: Two MAINTAINER email updates (urgent
  because the non-avagotech emails will start bouncing) an lpfc big
  endian oops fix, a 256 byte sector hang fix (to eliminate 256 byte
  sectors) and a storvsc fix which could cause test unit ready failures
  on bringup"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  MAINTAINERS: Revise lpfc maintainers for Avago Technologies ownership of Emulex
  MAINTAINERS, be2iscsi: change email domain
  sd: Disable support for 256 byte/sector disks
  lpfc: Fix breakage on big endian kernels
  storvsc: Set the SRB flags correctly when no data transfer is needed

Pull timer fix from Thomas Gleixner:
 "One more fix from the timer departement:

    - Handle division of negative nanosecond values proper on 32bit.

      A recent cleanup wrecked the sign handling of the dividend and
      dropped the check for negative divisors"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  ktime: Fix ktime_divns to do signed division

Pull irqchip fix from Thomas Gleixner:
 "A fix for a GIC-V3 irqchip regression which prevents some systems from
  booting"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/gicv3-its: ITS table size should not be smaller than PSZ

Pull two Ceph fixes from Sage Weil:
 "These fix an issue with the RBD notifications when there are topology
  changes in the cluster"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  Revert "libceph: clear r_req_lru_item in __unregister_linger_request()"
  libceph: request a new osdmap if lingering request maps to no osd

Pull btrfs fixes from Chris Mason:
 "I fixed up a regression from 4.0 where conversion between different
  raid levels would sometimes bail out without converting.

  Filipe tracked down a race where it was possible to double allocate
  chunks on the drive.

  Mark has a fix for fiemap.  All three will get bundled off for stable
  as well"

* 'for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix regression in raid level conversion
  Btrfs: fix racy system chunk allocation when setting block group ro
  btrfs: clear 'ret' in btrfs_check_shared() loop

Pull drm fixes from Dave Airlie:
 "Radeon has two displayport fixes, one for a regression.

  i915 regression flicker fix needed so 4.0 can get fixed.

  A bunch of msm fixes and a bunch of exynos fixes, these two are
  probably a bit larger than I'd like, but most of them seems pretty
  good"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux: (29 commits)
  drm/radeon: fix error flag checking in native aux path
  drm/radeon: retry dcpd fetch
  drm/msm/mdp5: fix incorrect parameter for msm_framebuffer_iova()
  drm/exynos: dp: Lower level of EDID read success message
  drm/exynos: cleanup exynos_drm_plane
  drm/exynos: 'win' is always unsigned
  drm/exynos: mixer: don't dump registers under spinlock
  drm/exynos: Consolidate return statements in fimd_bind()
  drm/exynos: Constify exynos_drm_crtc_ops
  drm/exynos: Fix build breakage on !DRM_EXYNOS_FIMD
  drm/exynos: mixer: Constify platform_device_id
  drm/exynos: mixer: cleanup pixelformat handling
  drm/exynos: mixer: also allow NV21 for the video processor
  drm/exynos: mixer: remove buffer count handling in vp_video_buffer()
  drm/exynos: plane: honor buffer offset for dma_addr
  drm/exynos: fb: use drm_format_num_planes to get buffer count
  drm/i915: fix screen flickering
  drm/msm: fix locking inconsistencies in gpu->destroy()
  drm/msm/dsi: Simplify the code to get the number of read byte
  drm/msm: Attach assigned encoder to eDP and DSI connectors
  ...

Pull networking fixes from David Miller:

 1) Don't leak ipvs->sysctl_tbl, from Tommi Rentala.

 2) Fix neighbour table entry leak in rocker driver, from Ying Xue.

 3) Do not emit bonding notifications for unregistered interfaces, from
    Nicolas Dichtel.

 4) Set ipv6 flow label properly when in TIME_WAIT state, from Florent
    Fourcot.

 5) Fix regression in ipv6 multicast filter test, from Henning Rogge.

 6) do_replace() in various footables netfilter modules is missing a
    check for 0 counters in the datastructure provided by the user.  Fix
    from Dave Jones, and found with trinity.

 7) Fix RCU bug in packet scheduler classifier module unloads, from
    Daniel Borkmann.

 8) Avoid deadlock in tcp_get_info() by using u64_sync.  From Eric
    Dumzaet.

 9) Input packet processing can race with inetdev_destroy() teardown,
    fix potential OOPS in ip_error() by explicitly testing whether the
    inetdev is still attached.  From Eric W Biederman.

10) MLDv2 parser in bridge multicast code breaks too early while
    parsing.  Fix from Thadeu Lima de Souza Cascardo.

11) Asking for settings on non-zero PHYID doesn't work because we do not
    import the command structure from the user and use the PHYID
    provided there.  Fix from Arun Parameswaran.

12) Fix UDP checksums with IPV6 RAW sockets, from Vlad Yasevich.

13) Missing NF_TABLES depends for TPROXY etc can cause build failures,
    fix from Florian Westphal.

14) Fix netfilter conntrack to handle RFC5961 challenge ACKs properly,
    from Jesper Dangaard Brouer.

15) If netlink autobind retry fails, we have to reset the sockets portid
    back to zero.  From Herbert Xu.

16) VXLAN netns exit code unregisters using wrong device, from John W
    Linville.

17) Add some USB device IDs to ath3k and btusb bluetooth drivers, from
    Dmitry Tunin and Wen-chien Jesse Sung.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (44 commits)
  bridge: fix lockdep splat
  net: core: 'ethtool' issue with querying phy settings
  bridge: fix parsing of MLDv2 reports
  ARM: zynq: DT: Use the zynq binding with macb
  net: macb: Disable half duplex gigabit on Zynq
  net: macb: Document zynq gem dt binding
  ipv4: fill in table id when replacing a route
  cdc_ncm: Fix tx_bytes statistics
  ipv4: Avoid crashing in ip_error
  tcp: fix a potential deadlock in tcp_get_info()
  net: sched: fix call_rcu() race on classifier module unloads
  net: phy: Make sure phy_start() always re-enables the phy interrupts
  ipv6: fix ECMP route replacement
  ipv6: do not delete previously existing ECMP routes if add fails
  Revert "netfilter: bridge: query conntrack about skb dnat"
  netfilter: ensure number of counters is >0 in do_replace()
  netfilter: nfnetlink_{log,queue}: Register pernet in first place
  tcp: don't over-send F-RTO probes
  tcp: only undo on partial ACKs in CA_Loss
  net/ipv6/udp: Fix ipv6 multicast socket filter regression
  ...

Pull block fixes from Jens Axboe:
 "Three small fixes that have been picked up the last few weeks.
  Specifically:

   - Fix a memory corruption issue in NVMe with malignant user
     constructed request.  From Christoph.

   - Kill (now) unused blk_queue_bio(), dm was changed to not need this
     anymore.  From Mike Snitzer.

   - Always use blk_schedule_flush_plug() from the io_schedule() path
     when flushing a plug, fixing a !TASK_RUNNING warning with md.  From
     Shaohua"

* 'for-linus' of git://git.kernel.dk/linux-block:
  sched: always use blk_schedule_flush_plug in io_schedule_out
  nvme: fix kernel memory corruption with short INQUIRY buffers
  block: remove export for blk_queue_bio

Pull md bugfixes from Neil Brown:
 "I have a few more raid5 bugfixes pending, but I want them to get a bit
  more review first.  In the meantime:

   - one serious RAID0 data corruption - caused by recent bugfix that
     wasn't reviewed properly.

   - one raid5 fix in new code (a couple more of those to come).

   - one little fix to stop static analysis complaining about silly rcu
     annotation"

* tag 'md/4.1-rc4-fixes' of git://neil.brown.name/md:
  md/bitmap: remove rcu annotation from pointer arithmetic.
  md/raid0: fix restore to sector variable in raid0_make_request
  raid5: fix broken async operation chain

Pull input fixes from Dmitry Torokhov:
 "Updates for the input subsystem.

  The main change is that we tell joydev not to touch "absolute mice",
  such as VMware virtual mouse, as that produced bad result (cursor
  stuck in upper right corner) with games"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: smtpe-ts - wait 50mS until polling for pen-up
  Input: smtpe-ts - use msecs_to_jiffies() instead of HZ
  Input: joydev - don't classify the vmmouse as a joystick
  Input: vmmouse - do not reference non-existing version of X driver
  Input: alps - fix finger jumps on lifting 2 fingers on v7 touchpad
  Input: elantech - fix semi-mt protocol for v3 HW
  Input: sx8654 - fix memory allocation check

Pull another crypto fix from Herbert Xu:
 "Fix ICV corruption in s390/ghash when the same tfm is used by more
  than one thread"

* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: s390/ghash - Fix incorrect ghash icv buffer handling.

Following lockdep splat was reported :

[   29.382286] ===============================
[   29.382315] [ INFO: suspicious RCU usage. ]
[   29.382344] 4.1.0-0.rc0.git11.1.fc23.x86_64 #1 Not tainted
[   29.382380] -------------------------------
[   29.382409] net/bridge/br_private.h:626 suspicious
rcu_dereference_check() usage!
[   29.382455]
               other info that might help us debug this:

[   29.382507]
               rcu_scheduler_active = 1, debug_locks = 0
[   29.382549] 2 locks held by swapper/0/0:
[   29.382576]  #0:  (((&p->forward_delay_timer))){+.-...}, at:
[<ffffffff81139f75>] call_timer_fn+0x5/0x4f0
[   29.382660]  #1:  (&(&br->lock)->rlock){+.-...}, at:
[<ffffffffa0450dc1>] br_forward_delay_timer_expired+0x31/0x140
[bridge]
[   29.382754]
               stack backtrace:
[   29.382787] CPU: 0 PID: 0 Comm: swapper/0 Not tainted
4.1.0-0.rc0.git11.1.fc23.x86_64 #1
[   29.382838] Hardware name: LENOVO 422916G/LENOVO, BIOS A1KT53AUS 04/07/2015
[   29.382882]  0000000000000000 3ebfc20364115825 ffff880666603c48
ffffffff81892d4b
[   29.382943]  0000000000000000 ffffffff81e124e0 ffff880666603c78
ffffffff8110bcd7
[   29.383004]  ffff8800785c9d00 ffff88065485ac58 ffff880c62002800
ffff880c5fc88ac0
[   29.383065] Call Trace:
[   29.383084]  <IRQ>  [<ffffffff81892d4b>] dump_stack+0x4c/0x65
[   29.383130]  [<ffffffff8110bcd7>] lockdep_rcu_suspicious+0xe7/0x120
[   29.383178]  [<ffffffffa04520f9>] br_fill_ifinfo+0x4a9/0x6a0 [bridge]
[   29.383225]  [<ffffffffa045266b>] br_ifinfo_notify+0x11b/0x4b0 [bridge]
[   29.383271]  [<ffffffffa0450d90>] ? br_hold_timer_expired+0x70/0x70 [bridge]
[   29.383320]  [<ffffffffa0450de8>]
br_forward_delay_timer_expired+0x58/0x140 [bridge]
[   29.383371]  [<ffffffffa0450d90>] ? br_hold_timer_expired+0x70/0x70 [bridge]
[   29.383416]  [<ffffffff8113a033>] call_timer_fn+0xc3/0x4f0
[   29.383454]  [<ffffffff81139f75>] ? call_timer_fn+0x5/0x4f0
[   29.383493]  [<ffffffff8110a90f>] ? lock_release_holdtime.part.29+0xf/0x200
[   29.383541]  [<ffffffffa0450d90>] ? br_hold_timer_expired+0x70/0x70 [bridge]
[   29.383587]  [<ffffffff8113a6a4>] run_timer_softirq+0x244/0x490
[   29.383629]  [<ffffffff810b68cc>] __do_softirq+0xec/0x670
[   29.383666]  [<ffffffff810b70d5>] irq_exit+0x145/0x150
[   29.383703]  [<ffffffff8189f506>] smp_apic_timer_interrupt+0x46/0x60
[   29.383744]  [<ffffffff8189d523>] apic_timer_interrupt+0x73/0x80
[   29.383782]  <EOI>  [<ffffffff816f131f>] ? cpuidle_enter_state+0x5f/0x2f0
[   29.383832]  [<ffffffff816f131b>] ? cpuidle_enter_state+0x5b/0x2f0

Problem here is that br_forward_delay_timer_expired() is a timer
handler, calling br_ifinfo_notify() which assumes either rcu_read_lock()
or RTNL are held.

Simplest fix seems to add rcu read lock section.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: NJosh Boyer <jwboyer@fedoraproject.org>
Reported-by: NDominick Grift <dac.override@gmail.com>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When trying to configure the settings for PHY1, using commands
like 'ethtool -s eth0 phyad 1 speed 100', the 'ethtool' seems to
modify other settings apart from the speed of the PHY1, in the
above case.

The ethtool seems to query the settings for PHY0, and use this
as the base to apply the new settings to the PHY1. This is
causing the other settings of the PHY 1 to be wrongly
configured.

The issue is caused by the '_ethtool_get_settings()' API, which
gets called because of the 'ETHTOOL_GSET' command, is clearing
the 'cmd' pointer (of type 'struct ethtool_cmd') by calling
memset. This clears all the parameters (if any) passed for the
'ETHTOOL_GSET' cmd. So the driver's callback is always invoked
with 'cmd->phy_address' as '0'.

The '_ethtool_get_settings()' is called from other files in the
'net/core'. So the fix is applied to the 'ethtool_get_settings()'
which is only called in the context of the 'ethtool'.
Signed-off-by: NArun Parameswaran <aparames@broadcom.com>
Reviewed-by: NRay Jui <rjui@broadcom.com>
Reviewed-by: NScott Branden <sbranden@broadcom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When more than a multicast address is present in a MLDv2 report, all but
the first address is ignored, because the code breaks out of the loop if
there has not been an error adding that address.

This has caused failures when two guests connected through the bridge
tried to communicate using IPv6. Neighbor discoveries would not be
transmitted to the other guest when both used a link-local address and a
static address.

This only happens when there is a MLDv2 querier in the network.

The fix will only break out of the loop when there is a failure adding a
multicast address.

The mdb before the patch:

dev ovirtmgmt port vnet0 grp ff02::1:ff7d:6603 temp
dev ovirtmgmt port vnet1 grp ff02::1:ff7d:6604 temp
dev ovirtmgmt port bond0.86 grp ff02::2 temp

After the patch:

dev ovirtmgmt port vnet0 grp ff02::1:ff7d:6603 temp
dev ovirtmgmt port vnet1 grp ff02::1:ff7d:6604 temp
dev ovirtmgmt port bond0.86 grp ff02::fb temp
dev ovirtmgmt port bond0.86 grp ff02::2 temp
dev ovirtmgmt port bond0.86 grp ff02::d temp
dev ovirtmgmt port vnet0 grp ff02::1:ff00:76 temp
dev ovirtmgmt port bond0.86 grp ff02::16 temp
dev ovirtmgmt port vnet1 grp ff02::1:ff00:77 temp
dev ovirtmgmt port bond0.86 grp ff02::1:ff00:def temp
dev ovirtmgmt port bond0.86 grp ff02::1:ffa1:40bf temp

Fixes: 08b202b6 ("bridge br_multicast: IPv6 MLD support.")
Reported-by: NRik Theys <Rik.Theys@esat.kuleuven.be>
Signed-off-by: NThadeu Lima de Souza Cascardo <cascardo@redhat.com>
Tested-by: NRik Theys <Rik.Theys@esat.kuleuven.be>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use the new zynq binding for macb ethernet, since it will disable half
duplex gigabit like the Zynq TRM says to do.
Signed-off-by: NNathan Sullivan <nathan.sullivan@ni.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

According to the Zynq TRM, gigabit half duplex is not supported.  Add a
new cap and compatible string so Zynq can avoid advertising that mode.
Signed-off-by: NNathan Sullivan <nathan.sullivan@ni.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NNathan Sullivan <nathan.sullivan@ni.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When replacing an IPv4 route, tb_id member of the new fib_alias
structure is not set in the replace code path so that the new route is
ignored.

Fixes: 0ddcf43d ("ipv4: FIB Local/MAIN table collapse")
Signed-off-by: NMichal Kubecek <mkubecek@suse.cz>
Acked-by: NAlexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The tx_curr_frame_payload field is u32. When we try to calculate a
small negative delta based on it, we end up with a positive integer
close to 2^32 instead.  So the tx_bytes pointer increases by about
2^32 for every transmitted frame.

Fix by calculating the delta as a signed long.

Cc: Ben Hutchings <ben.hutchings@codethink.co.uk>
Reported-by: NFlorian Bruhin <me@the-compiler.org>
Fixes: 7a1e890e ("usbnet: Fix tx_bytes statistic running backward in cdc_ncm")
Signed-off-by: NBjørn Mork <bjorn@mork.no>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pablo Neira Ayuso says:

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

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

1) Fix a race in nfnetlink_log and nfnetlink_queue that can lead to a crash.
   This problem is due to wrong order in the per-net registration and netlink
   socket events. Patch from Francesco Ruggeri.

2) Make sure that counters that userspace pass us are higher than 0 in all the
   x_tables frontends. Discovered via Trinity, patch from Dave Jones.

3) Revert a patch for br_netfilter to rely on the conntrack status bits. This
   breaks stateless IPv6 NAT transformations. Patch from Florian Westphal.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ip_error does not check if in_dev is NULL before dereferencing it.

IThe following sequence of calls is possible:
CPU A                          CPU B
ip_rcv_finish
    ip_route_input_noref()
        ip_route_input_slow()
                               inetdev_destroy()
    dst_input()

With the result that a network device can be destroyed while processing
an input packet.

A crash was triggered with only unicast packets in flight, and
forwarding enabled on the only network device.   The error condition
was created by the removal of the network device.

As such it is likely the that error code was -EHOSTUNREACH, and the
action taken by ip_error (if in_dev had been accessible) would have
been to not increment any counters and to have tried and likely failed
to send an icmp error as the network device is going away.

Therefore handle this weird case by just dropping the packet if
!in_dev.  It will result in dropping the packet sooner, and will not
result in an actual change of behavior.

Fixes: 251da413 ("ipv4: Cache ip_error() routes even when not forwarding.")
Reported-by: NVittorio Gambaletta <linuxbugs@vittgam.net>
Tested-by: NVittorio Gambaletta <linuxbugs@vittgam.net>
Signed-off-by: NVittorio Gambaletta <linuxbugs@vittgam.net>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Taking socket spinlock in tcp_get_info() can deadlock, as
inet_diag_dump_icsk() holds the &hashinfo->ehash_locks[i],
while packet processing can use the reverse locking order.

We could avoid this locking for TCP_LISTEN states, but lockdep would
certainly get confused as all TCP sockets share same lockdep classes.

[  523.722504] ======================================================
[  523.728706] [ INFO: possible circular locking dependency detected ]
[  523.734990] 4.1.0-dbg-DEV #1676 Not tainted
[  523.739202] -------------------------------------------------------
[  523.745474] ss/18032 is trying to acquire lock:
[  523.750002]  (slock-AF_INET){+.-...}, at: [<ffffffff81669d44>] tcp_get_info+0x2c4/0x360
[  523.758129]
[  523.758129] but task is already holding lock:
[  523.763968]  (&(&hashinfo->ehash_locks[i])->rlock){+.-...}, at: [<ffffffff816bcb75>] inet_diag_dump_icsk+0x1d5/0x6c0
[  523.774661]
[  523.774661] which lock already depends on the new lock.
[  523.774661]
[  523.782850]
[  523.782850] the existing dependency chain (in reverse order) is:
[  523.790326]
-> #1 (&(&hashinfo->ehash_locks[i])->rlock){+.-...}:
[  523.796599]        [<ffffffff811126bb>] lock_acquire+0xbb/0x270
[  523.802565]        [<ffffffff816f5868>] _raw_spin_lock+0x38/0x50
[  523.808628]        [<ffffffff81665af8>] __inet_hash_nolisten+0x78/0x110
[  523.815273]        [<ffffffff816819db>] tcp_v4_syn_recv_sock+0x24b/0x350
[  523.822067]        [<ffffffff81684d41>] tcp_check_req+0x3c1/0x500
[  523.828199]        [<ffffffff81682d09>] tcp_v4_do_rcv+0x239/0x3d0
[  523.834331]        [<ffffffff816842fe>] tcp_v4_rcv+0xa8e/0xc10
[  523.840202]        [<ffffffff81658fa3>] ip_local_deliver_finish+0x133/0x3e0
[  523.847214]        [<ffffffff81659a9a>] ip_local_deliver+0xaa/0xc0
[  523.853440]        [<ffffffff816593b8>] ip_rcv_finish+0x168/0x5c0
[  523.859624]        [<ffffffff81659db7>] ip_rcv+0x307/0x420

Lets use u64_sync infrastructure instead. As a bonus, 64bit
arches get optimized, as these are nop for them.

Fixes: 0df48c26 ("tcp: add tcpi_bytes_acked to tcp_info")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Just two small DP fixes for 4.1

* 'drm-fixes-4.1' of git://people.freedesktop.org/~agd5f/linux:
  drm/radeon: fix error flag checking in native aux path
  drm/radeon: retry dcpd fetch

There's a stable backport from Ander [1] that combines this and a few
other commits to fix the flickering on v4.0, reported in [2] among
others. Having this upstream is obviously a requirement for stable.

* tag 'drm-intel-fixes-2015-05-21' of git://anongit.freedesktop.org/drm-intel:
  drm/i915: fix screen flickering