In 2009 Philip Reiser notied that a few users of netlink connector
interface needed a capability check and added the idiom
cap_raised(nsp->eff_cap, CAP_SYS_ADMIN) to a few of them, on the premise
that netlink was asynchronous.

In 2011 Patrick McHardy noticed we were being silly because netlink is
synchronous and removed eff_cap from the netlink_skb_params and changed
the idiom to cap_raised(current_cap(), CAP_SYS_ADMIN).

Looking at those spots with a fresh eye we should be calling
capable(CAP_SYS_ADMIN).  The only reason I can see for not calling capable
is that it once appeared we were not in the same task as the caller which
would have made calling capable() impossible.

In the initial user_namespace the only difference between between
cap_raised(current_cap(), CAP_SYS_ADMIN) and capable(CAP_SYS_ADMIN) are a
few sanity checks and the fact that capable(CAP_SYS_ADMIN) sets
PF_SUPERPRIV if we use the capability.

Since we are going to be using root privilege setting PF_SUPERPRIV seems
the right thing to do.

The motivation for this that patch is that in a child user namespace
cap_raised(current_cap(),...) tests your capabilities with respect to that
child user namespace not capabilities in the initial user namespace and
thus will allow processes that should be unprivielged to use the kernel
services that are only protected with cap_raised(current_cap(),..).

To fix possible user_namespace issues and to just clean up the code
replace cap_raised(current_cap(), CAP_SYS_ADMIN) with
capable(CAP_SYS_ADMIN).
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Philipp Reisner <philipp.reisner@linbit.com>
Acked-by: Serge E. Hallyn <serge.hallyn@canonical.com>
Acked-by: Andrew G. Morgan <morgan@kernel.org>
Cc: Vasiliy Kulikov <segoon@openwall.com>
Cc: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

dst_check() will take care of SA (and obsolete field), hence
IPsec rekeying scenario is taken into account.
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Vlad Yaseivch <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

commit 7d3d43da (net: In unregister_netdevice_notifier unregister
the netdevices.) makes pktgen crashing at module unload.

[  296.820578] BUG: spinlock bad magic on CPU#6, rmmod/3267
[  296.820719]  lock: ffff880310c38000, .magic: ffff8803, .owner: <none>/-1, .owner_cpu: -1
[  296.820943] Pid: 3267, comm: rmmod Not tainted 3.4.0-rc5+ #254
[  296.821079] Call Trace:
[  296.821211]  [<ffffffff8168a715>] spin_dump+0x8a/0x8f
[  296.821345]  [<ffffffff8168a73b>] spin_bug+0x21/0x26
[  296.821507]  [<ffffffff812b4741>] do_raw_spin_lock+0x131/0x140
[  296.821648]  [<ffffffff8169188e>] _raw_spin_lock+0x1e/0x20
[  296.821786]  [<ffffffffa00cc0fd>] __pktgen_NN_threads+0x4d/0x140 [pktgen]
[  296.821928]  [<ffffffffa00ccf8d>] pktgen_device_event+0x10d/0x1e0 [pktgen]
[  296.822073]  [<ffffffff8154ed4f>] unregister_netdevice_notifier+0x7f/0x100
[  296.822216]  [<ffffffffa00d2a0b>] pg_cleanup+0x48/0x73 [pktgen]
[  296.822357]  [<ffffffff8109528e>] sys_delete_module+0x17e/0x2a0
[  296.822502]  [<ffffffff81699652>] system_call_fastpath+0x16/0x1b

Hold the pktgen_thread_lock while splicing pktgen_threads, and test
pktgen_exiting in pktgen_device_event() to make unload faster.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This reverts commit 8a83a00b.

It causes regressions for S390 devices, because it does an
unconditional DST drop on SKBs for vlans and the QETH device
needs the neighbour entry hung off the DST for certain things
on transmit.

Arnd can't remember exactly why he even needed this change.

Conflicts:

	drivers/net/macvlan.c
	net/8021q/vlan_dev.c
	net/core/dev.c
Signed-off-by: David S. Miller <davem@davemloft.net>

The NEQ interrupt is only triggered when there was no previous pending
interrupt. If we request irq handling after an interrupt has occurred,
we will never get an interrupt until we call H_RESET_EVENTS.

Events seem to be cleared when we first register the NEQ. So, when we
requested irq handling right after registering it, a possible race with
an interrupt was much less likely. Now, there is a chance we may lose
this race and never get any events.

The fix here is to poll and acknowledge any events that might have
happened right after registering the irq handler.
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Since the caller (PM resume code) is not the one holding rtnl, when taking the
'else' branch rtnl may be released at any moment, thereby defeating the whole
purpose of this code block.
Signed-off-by: Benjamin Poirier <bpoirier@suse.de>
Tested-by: Jeff Pieper <jeffrey.e.pieper@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Due to RCU lookups and RCU based release, fib_info objects can
be found during lookup which have fi->fib_dead set.

We must ignore these entries, otherwise we risk dereferencing
the parts of the entry which are being torn down.
Reported-by: Yevgen Pronenko <yevgen.pronenko@sonymobile.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The r8169 may get stuck or show bad behaviour after activating TSO :
the net_device is not stopped when it has no more TX descriptors.
This problem comes from TX_BUFS_AVAIL which may reach -1 when all
transmit descriptors are in use. The patch simply tries to keep positive
values.

Tested with 8111d(onboard) on a D510MO, and with 8111e(onboard) on a
Zotac 890GXITX.
Signed-off-by: Julien Ducourthial <jducourt@free.fr>
Acked-by: Francois Romieu <romieu@fr.zoreil.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

If RSS is disabled on the PF (efx->n_rx_channels == 1) we try to set
up the indirection table so that VFs can use it, setting
efx->rss_spread = efx_vf_size(efx).  But if SR-IOV was disabled at
compile time, this evaluates to 0 and we end up dividing by zero when
initialising the table.

I considered changing the fallback definition of efx_vf_size() to
return 1, but its value is really meaningless if we are not going to
enable VFs.  Therefore add a condition of efx_sriov_wanted(efx) in
efx_probe_interrupts().
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

When the kernel validates set TCP/UDP port actions, it looks at
the ports in the existing flow to make sure that the L4 header exists.
However, these actions always use the IPv4 version of the struct.
Following patch fixes this by checking for flow ip protocol first.
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>

Neither compare_ether_addr() nor compare_ether_addr_64bits()
(as it can fall back to the former) have comparison semantics
like memcmp() where the sign of the return value indicates sort
order. We had a bug in the wireless code due to a blind memcmp
replacement because of this.

A cursory look suggests that the wireless bug was the only one
due to this semantic difference.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Some RNDIS devices include a bogus CDC Union descriptor pointing
to non-existing interfaces.  The RNDIS code is already prepared
to handle devices without a CDC Union descriptor by hardwiring
the driver to use interfaces 0 and 1, which is correct for the
devices with the bogus descriptor as well. So we can reuse the
existing workaround.

Cc: Markus Kolb <linux-201011@tower-net.de>
Cc: Iker Salmón San Millán <shaola@esdebian.org>
Cc: Jonathan Nieder <jrnieder@gmail.com>
Cc: Oliver Neukum <oliver@neukum.org>
Cc: 655387@bugs.debian.org
Cc: stable@vger.kernel.org
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>

This is a bug fix for an "interface fails to load" issue.
The issue occurs when bnx2x driver loads after UNDI driver was previously
loaded over the chip. In such a scenario the UNDI driver is loaded and operates
in the pre-boot kernel, within its own specific host memory address range.
When the pre-boot stage is complete, the real kernel is loaded, in a new and
distinct host memory address range. The transition from pre-boot stage to boot
is asynchronous from UNDI point of view.

A race condition occurs when UNDI driver triggers a DMAE transaction to valid
host addresses in the pre-boot stage, when control is diverted to the real
kernel. This results in access to illegal addresses by our HW as the addresses
which were valid in the preboot stage are no longer considered valid.
Specifically, the 'was_error' bit in the pci glue of our device is set. This
causes all following pci transactions from chip to host to timeout (in
accordance to the pci spec).
Signed-off-by: Ariel Elior <ariele@broadcom.com>
Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Silence sparse warnings shown below:
...
drivers/net/ethernet/intel/e1000/e1000_main.c:3435:17: warning:
	cast to restricted __le64
drivers/net/ethernet/intel/e1000/e1000_main.c:3435:17: warning:
	cast to restricted __le64
...
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

igb and ixgbe incorrectly call netdev_tx_reset_queue() from
i{gb|xgbe}_clean_tx_ring() this sort of works in most cases except
when the number of real tx queues changes. When the number of real
tx queues changes netdev_tx_reset_queue() only gets called on the
new number of queues so when we reduce the number of queues we risk
triggering the watchdog timer and repeated device resets.

So this is not only a cosmetic issue but causes real bugs. For
example enabling/disabling DCB or FCoE in ixgbe will trigger this.

CC: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Tested-by: John Bishop <johnx.bishop@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

This patch fixes a possible lock-up bug where rtnl_lock might not
get released.
Signed-off-by: Ansis Atteka <aatteka@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>

Pull second set of MFD fixes from Samuel Ortiz:
 "This time we only have a one liner fixing an omap-usb build error."

* tag 'mfd-for-linus-3.4-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/sameo/mfd-2.6:
  mfd: Fix build breakage in omap-usb-host.c

* efi-vars:
  efivars: Improve variable validation

Ben Hutchings pointed out that the validation in efivars was inadequate -
most obviously, an entry with size 0 would server as a DoS against the
kernel. Improve this based on his suggestions.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull libata fixes from Jeff Garzik:

1) Fix regression that could cause a misdiagnosis, which in turn could
   lead to an erroneous 3.0 Gbps -> 1.5 downshift, particularly when hotplug
   and suspend/resume is involved.

2) Fix a regression that led to ata%d controller ids being numbered one
   larger than in <= 3.4-rc3 (oh, the horror!).  Controller ids should now be
   as expected.

3) add some DT, PCI id's

4) ata/pata_arasan_cf: minor cpp fixing/cleaning

* tag 'tag/upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
  ata: ahci_platform: Add synopsys ahci controller in DT's compatible list
  ata/pata_arasan_cf: Move arasan_cf_pm_ops out of #ifdef, #endif macros
  libata: init ata_print_id to 0
  ahci: Detect Marvell 88SE9172 SATA controller
  libata: skip old error history when counting probe trials

Pull i2c embedded fixes from Wolfram Sang:
 "Here are some typical i2c driver bugfixes for 3.4.  Missed clock
  handling, improper timeout fixes, hardware wrokarounds...  All
  patches have been in linux-next for a few days, too."

* 'i2c-embedded/for-current' of git://git.pengutronix.de/git/wsa/linux:
  i2c: mxs: disable QUEUE when sending is done
  i2c: mxs: handle spurious interrupt
  i2c-eg20t: Modify MODULE_AUTHOR's email address
  i2c-eg20t: change timeout value 50msec to 1000msec
  i2c: tegra: Add delay before resetting the controller after NACK
  i2c: pnx: Disable clk in suspend

Pull drm fixes from Dave Airlie:
 "Just some regression fixes from Ben along with a variable that gcc
  failed to spot is uninitialised."

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  nouveau: initialise has_optimus variable.
  drm/nv10/gpio: fix thinko in mask for gpio lines 2-9
  nvc0/fb: shut up PMFB interrupt after the first occurrence
  drm/nouveau/hdmi: use correct hdmi regs for nvaa/nvac
  drm/nouveau/bios: fix regression on some nv4x board

Pull networking fixes from David Miller:

 1) Transfer padding was wrong for full-speed USB in ASIX driver, fix
    from Ingo van Lil.

 2) Propagate the negative packet offset fix into the PowerPC BPF JIT.
    From Jan Seiffert.

 3) dl2k driver's private ioctls were letting unprivileged tasks make
    MII writes and other ugly bits like that.  Fix from Jeff Mahoney.

 4) Fix TX VLAN and RX packet drops in ucc_geth, from Joakim Tjernlund.

 5) OOPS and network namespace fixes in IPVS from Hans Schillstrom and
    Julian Anastasov.

 6) Fix races and sleeping in locked context bugs in drop_monitor, from
    Neil Horman.

 7) Fix link status indication in smsc95xx driver, from Paolo Pisati.

 8) Fix bridge netfilter OOPS, from Peter Huang.

 9) L2TP sendmsg can return on error conditions with the socket lock
    held, oops.  Fix from Sasha Levin.

10) udp_diag should return meaningful values for socket memory usage,
    from Shan Wei.

11) Eric Dumazet is so awesome he gets his own section:

       Socket memory cgroup code (I never should have applied those
       patches, grumble...) made erroneous changes to
       sk_sockets_allocated_read_positive().  It was changed to
       use percpu_counter_sum_positive (which requires BH disabling)
       instead of percpu_counter_read_positive (which does not).
       Revert back to avoid crashes and lockdep warnings.

       Adjust the default tcp_adv_win_scale and tcp_rmem[2] values
       to fix throughput regressions.  This is necessary as a result
       of our more precise skb->truesize tracking.

       Fix SKB leak in netem packet scheduler.

12) New device IDs for various bluetooth devices, from Manoj Iyer,
    AceLan Kao, and Steven Harms.

13) Fix command completion race in ipw2200, from Stanislav Yakovlev.

14) Fix rtlwifi oops on unload, from Larry Finger.

15) Fix hard_mtu when adjusting hard_header_len in smsc95xx driver.
    From Stephane Fillod.

16) ehea driver registers it's IRQ before all the necessary state is
    setup, resulting in crashes.  Fix from Thadeu Lima de Souza
    Cascardo.

17) Fix PHY connection failures in davinci_emac driver, from Anatolij
    Gustschin.

18) Missing break; in switch statement in bluetooth's
    hci_cmd_complete_evt().  Fix from Szymon Janc.

19) Fix queue programming in iwlwifi, from Johannes Berg.

20) Interrupt throttling defaults not being actually programmed into the
    hardware, fix from Jeff Kirsher and Ying Cai.

21) TLAN driver SKB encoding in descriptor busted on 64-bit, fix from
    Benjamin Poirier.

22) Fix blind status block RX producer pointer deref in TG3 driver, from
    Matt Carlson.

23) Promisc and multicast are busted on ehea, fixes from Thadeu Lima de
    Souza Cascardo.

24) Fix crashes in 6lowpan, from Alexander Smirnov.

25) tcp_complete_cwr() needs to be careful to not rewind the CWND to
    ssthresh if ssthresh has the "infinite" value.  Fix from Yuchung
    Cheng.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (81 commits)
  sungem: Fix WakeOnLan
  tcp: change tcp_adv_win_scale and tcp_rmem[2]
  net: l2tp: unlock socket lock before returning from l2tp_ip_sendmsg
  drop_monitor: prevent init path from scheduling on the wrong cpu
  usbnet: fix failure handling in usbnet_probe
  usbnet: fix leak of transfer buffer of dev->interrupt
  ucc_geth: Add 16 bytes to max TX frame for VLANs
  net: ucc_geth, increase no. of HW RX descriptors
  netem: fix possible skb leak
  sky2: fix receive length error in mixed non-VLAN/VLAN traffic
  sky2: propogate rx hash when packet is copied
  net: fix two typos in skbuff.h
  cxgb3: Don't call cxgb_vlan_mode until q locks are initialized
  ixgbe: fix calling skb_put on nonlinear skb assertion bug
  ixgbe: Fix a memory leak in IEEE DCB
  igbvf: fix the bug when initializing the igbvf
  smsc75xx: enable mac to detect speed/duplex from phy
  smsc75xx: declare smsc75xx's MII as GMII capable
  smsc75xx: fix phy interrupt acknowledge
  smsc75xx: fix phy init reset loop
  ...

Pull hwmon fixes from Guenter Roeck:
 "Fix OOPS seen in coretemp driver if the CPU core ID is too large"

* tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: (coretemp) Increase CPU core limit
  hwmon: (coretemp) fix oops on cpu unplug

SPEAr13xx series of SoCs contain Synopsys AHCI SATA Controller which shares
ahci_platform driver with other controller versions.

This patch updates DT compatible list for ahci_platform. It also updates and
renames binding documentation to more generic name.
Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Cc: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

#ifdef, #endif is not required in definition/usage of arasan_cf_pm_ops. So, move
this definition and its usage outside of them.
Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

When comparing the dmesg between 3.4-rc3 and 3.4-rc4 I found the
following differences:

 -ata1: SATA max UDMA/133 abar m2048@0xf9fff000 port 0xf9fff100 irq 47
 -ata2: SATA max UDMA/133 abar m2048@0xf9fff000 port 0xf9fff180 irq 47
 -ata3: DUMMY
 +ata2: SATA max UDMA/133 abar m2048@0xf9fff000 port 0xf9fff100 irq 47
 +ata3: SATA max UDMA/133 abar m2048@0xf9fff000 port 0xf9fff180 irq 47
  ata4: DUMMY
  ata5: DUMMY
 -ata6: SATA max UDMA/133 abar m2048@0xf9fff000 port 0xf9fff380 irq 47
 +ata6: DUMMY
 +ata7: SATA max UDMA/133 abar m2048@0xf9fff000 port 0xf9fff380 irq 47

The change of numbering comes from commit 85d6725b ("libata:
make ata_print_id atomic") that changed lines like

	ap->print_id = ata_print_id++;
		to
	ap->print_id = atomic_inc_return(&ata_print_id);

As the latter behaves like ++ata_print_id, we must initialize
it to zero to start the numbering from one.
Signed-off-by: Tero Roponen <tero.roponen@gmail.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

The Marvell 88SE9172 SATA controller (PCI ID 1b4b 917a) already worked
once it was detected, but was missing an ahci_pci_tbl entry.

Boot tested on a Gigabyte Z68X-UD3H-B3 motherboard.
Signed-off-by: Matt Johnson <johnso87@illinois.edu>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

Commit d9027470("[libata] Add ATA transport class") introduced
ATA_EFLAG_OLD_ER to mark entries in the error ring as cleared.

But ata_count_probe_trials_cb() didn't check this flag and it still
counts the old error history. So wrong probe trials count is returned
and it causes problem, for example, SATA link speed is slowed down from
3.0Gbps to 1.5Gbps.

Fix it by checking ATA_EFLAG_OLD_ER in ata_count_probe_trials_cb().

Cc: stable <stable@vger.kernel.org> # 2.6.37+
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless into for-davem

By default, iwlwifi uses order-1 pages (8 KB) to store incoming frames,
but doesnt say so in skb->truesize.

This makes very possible to exhaust kernel memory since these skb evade
normal socket memory accounting.

As struct ieee80211_hdr is going to be pulled before calling IP stack,
there is no need to use dev_alloc_skb() to reserve NET_SKB_PAD bytes.
alloc_skb() is ok in this driver, allowing more tailroom.

Pull beginning of frame in skb header, in the hope we can reuse order-1
pages in the driver immediately for small frames and reduce their
truesize to the minimum (linear skbs)
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Cc: "John W. Linville" <linville@tuxdriver.com>
Cc: Neal Cardwell <ncardwell@google.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

After this commit:

commit aacc1bea
Author: Multanen, Eric W <eric.w.multanen@intel.com>
Date:   Wed Mar 28 07:49:09 2012 +0000

    ixgbe: driver fix for link flap

The BIT_APP_UPCHG bit is no longer set when ixgbe_dcbnl_set_all() is
called. This results in the FCoE app user priority never getting set
and the driver will not configure the tx_rings correctly for FCoE
packets which use the SAN MTU and FCoE offloads.

We resolve this regression by fixing ixgbe_copy_dcb_cfg() to also
check for FCoE application changes. Additionally, we can drop the
IEEE variants of get_dcb_app() because this path is never called
with the IEEE mode enabled.
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

It was possible for shutdown to pull the rug out from other driver entry
points.  Now we just grab the rtnl lock before taking everything apart.
Thanks to Hariharan for noticing this tight race condition.
Signed-off-by: Don Skidmore <donald.c.skidmore@intel.com>
Cc: Hariharan Nagarajan <hanagara@cisco.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

We should initialise this to 0 really to avoid getting false positives.

Cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

WakeOnLan was broken in this driver because gp->asleep_wol is a 1-bit
bitfield and it was being assigned WAKE_MAGIC, which is (1 << 5).
gp->asleep_wol remains 0 and the machine never wakes up.  Fixed by casting
gp->wake_on_lan to bool.  Tested on an iBook G4.
Signed-off-by: Gerard Lledo <gerard.lledo@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

tcp_adv_win_scale default value is 2, meaning we expect a good citizen
skb to have skb->len / skb->truesize ratio of 75% (3/4)

In 2.6 kernels we (mis)accounted for typical MSS=1460 frame :
1536 + 64 + 256 = 1856 'estimated truesize', and 1856 * 3/4 = 1392.
So these skbs were considered as not bloated.

With recent truesize fixes, a typical MSS=1460 frame truesize is now the
more precise :
2048 + 256 = 2304. But 2304 * 3/4 = 1728.
So these skb are not good citizen anymore, because 1460 < 1728

(GRO can escape this problem because it build skbs with a too low
truesize.)

This also means tcp advertises a too optimistic window for a given
allocated rcvspace : When receiving frames, sk_rmem_alloc can hit
sk_rcvbuf limit and we call tcp_prune_queue()/tcp_collapse() too often,
especially when application is slow to drain its receive queue or in
case of losses (netperf is fast, scp is slow). This is a major latency
source.

We should adjust the len/truesize ratio to 50% instead of 75%

This patch :

1) changes tcp_adv_win_scale default to 1 instead of 2

2) increase tcp_rmem[2] limit from 4MB to 6MB to take into account
better truesize tracking and to allow autotuning tcp receive window to
reach same value than before. Note that same amount of kernel memory is
consumed compared to 2.6 kernels.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Tom Herbert <therbert@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>