Commit Graph

426860 Commits

Author SHA1 Message Date
Moni Shoua
b4a26a2728 IB: Report using RoCE IP based gids in port caps
For userspace RoCE UD QPs we need to know the GID format that the
kernel uses, e.g when working over older kernels. For that end, add a
new port capability IB_PORT_IP_BASED_GIDS and report it when query
port is issued.

Signed-off-by: Moni Shoua <monis@mellanox.co.il>
Signed-off-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-02-13 14:46:03 -08:00
Moni Shoua
ad4885d279 IB/mlx4: Build the port IBoE GID table properly under bonding
When scanning netdevices we need to check a few more conditions and
cases to build the IBoE GID table properly.  For example, under
bonding we must make sure that when a port is down, the bond IP
address isn't programmed as a GID, since doing so will cause failure
with IB core flows that selects ports by GID.

Signed-off-by: Moni Shoua <monis@mellanox.co.il>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-02-13 14:31:09 -08:00
Moni Shoua
5071456fe2 IB/mlx4: Do IBoE GID table resets per-port
The IBoE code used to reset the GID table did it for all Ethernet
ports of the device.  Since the whole architecture of generating GIDs
and responding to events is port-based, this is inefficient and can
lead to wrong content in the GID table.  Change the reset flow to be
per-port.

Signed-off-by: Moni Shoua <monis@mellanox.co.il>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-02-13 14:31:08 -08:00
Moni Shoua
ddf8bd3491 IB/mlx4: Do IBoE locking earlier when initializing the GID table
Updating the GID table under IBoE requires read/write from/to shared
data structures.  These data structures are protected with the device
iboe lock.  The flows that modify the GID table start from

    1. Initializing the GID table
    2. NETDEV events
    3. INET or INET6 events

This patch makes sure that the flow of initializing the GID table is
consistent with the other two flows w.r.t on what step the lock is taken.

Signed-off-by: Moni Shoua <monis@mellanox.co.il>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-02-13 14:31:08 -08:00
Moni Shoua
4ce5a5744a IB/mlx4: Move rtnl locking to the right place
On the one hand, the invocation of netdev_master_upper_dev_get()
within mlx4_ib_scan_netdevs() must be done with rtnl lock held.  On
the other hand, it's wrong to call rtnl_lock() from within this
function since it's also called by our netdev notifier callback.
Therefore move the locking to mlx4_ib_add() so that both cases are
covered.

Signed-off-by: Moni Shoua <monis@mellanox.co.il>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-02-13 14:31:08 -08:00
Moni Shoua
acc4fccf4e IB/mlx4: Make sure GID index 0 is always occupied
Make sure that for Ethernet ports, the port GID table index 0 is always
occupied with a default GID of the relevant IPv6 link-local adderss.

This provides better user experience for legacy applications that don't use
the RDMA CM and were working on index 0 prior to the IP addressing change.

Also, as GIDs are generated from IP addresses of the network devices that
are associated with the port, it's basically possible that the GID table
will be empty if no IP address was assigned.  This doesn't comply with the
IB spec section 4.1.1 "GID usage and properties".

Signed-off-by: Moni Shoua <monis@mellanox.co.il>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-02-13 14:31:08 -08:00
Florian Westphal
fe6cc55f3a net: ip, ipv6: handle gso skbs in forwarding path
Marcelo Ricardo Leitner reported problems when the forwarding link path
has a lower mtu than the incoming one if the inbound interface supports GRO.

Given:
Host <mtu1500> R1 <mtu1200> R2

Host sends tcp stream which is routed via R1 and R2.  R1 performs GRO.

In this case, the kernel will fail to send ICMP fragmentation needed
messages (or pkt too big for ipv6), as GSO packets currently bypass dstmtu
checks in forward path. Instead, Linux tries to send out packets exceeding
the mtu.

When locking route MTU on Host (i.e., no ipv4 DF bit set), R1 does
not fragment the packets when forwarding, and again tries to send out
packets exceeding R1-R2 link mtu.

This alters the forwarding dstmtu checks to take the individual gso
segment lengths into account.

For ipv6, we send out pkt too big error for gso if the individual
segments are too big.

For ipv4, we either send icmp fragmentation needed, or, if the DF bit
is not set, perform software segmentation and let the output path
create fragments when the packet is leaving the machine.
It is not 100% correct as the error message will contain the headers of
the GRO skb instead of the original/segmented one, but it seems to
work fine in my (limited) tests.

Eric Dumazet suggested to simply shrink mss via ->gso_size to avoid
sofware segmentation.

However it turns out that skb_segment() assumes skb nr_frags is related
to mss size so we would BUG there.  I don't want to mess with it considering
Herbert and Eric disagree on what the correct behavior should be.

Hannes Frederic Sowa notes that when we would shrink gso_size
skb_segment would then also need to deal with the case where
SKB_MAX_FRAGS would be exceeded.

This uses sofware segmentation in the forward path when we hit ipv4
non-DF packets and the outgoing link mtu is too small.  Its not perfect,
but given the lack of bug reports wrt. GRO fwd being broken this is a
rare case anyway.  Also its not like this could not be improved later
once the dust settles.

Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Reported-by: Marcelo Ricardo Leitner <mleitner@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-13 17:17:02 -05:00
Florian Westphal
d206940319 net: core: introduce netif_skb_dev_features
Will be used by upcoming ipv4 forward path change that needs to
determine feature mask using skb->dst->dev instead of skb->dev.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-13 17:17:02 -05:00
dingtianhong
f80889a5b7 bonding: Fix deadlock in bonding driver when using netpoll
The bonding driver take write locks and spin locks that are shared
by the tx path in enslave processing and notification processing,
If the netconsole is in use, the bonding can call printk which puts
us in the netpoll tx path, if the netconsole is attached to the bonding
driver, result in deadlock.

So add protection for these place, by checking the netpoll_block_tx
state, we can defer the sending of the netconsole frames until a later
time using the retransmit feature of netpoll_send_skb that is triggered
on the return code NETDEV_TX_BUSY.

Cc: Jay Vosburgh <fubar@us.ibm.com>
Cc: Veaceslav Falico <vfalico@redhat.com>
Cc: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: Ding Tianhong <dingtianhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-13 17:08:29 -05:00
Paul Gortmaker
455016e5dc Documentation/networking: delete orphaned 3c505.txt file.
In the commit 0e245dbaac
("drivers/net: delete the 3Com 3c505/3c507 intel i825xx support")
we clobbered the 3c505 driver (over a year ago) along with other
abandoned ISA drivers.

However, this orphaned README file escaped detection at that
time, and has lived on until today. Get rid of it now.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-13 17:08:29 -05:00
wangweidong
efb842c45e sctp: optimize the sctp_sysctl_net_register
Here, when the net is init_net, we needn't to kmemdup the ctl_table
again. So add a check for net. Also we can save some memory.

Signed-off-by: Wang Weidong <wangweidong1@huawei.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-13 17:08:29 -05:00
wangweidong
22a1f5140e sctp: fix a missed .data initialization
As commit 3c68198e75111a90("sctp: Make hmac algorithm selection for
 cookie generation dynamic"), we miss the .data initialization.
If we don't use the net_namespace, the problem that parts of the
sysctl configuration won't be isolation and won't occur.

In sctp_sysctl_net_register(), we register the sysctl for each
net, in the for(), we use the 'table[i].data' as check condition, so
when the 'i' is the index of sctp_hmac_alg, the data is NULL, then
break. So add the .data initialization.

Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Wang Weidong <wangweidong1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-13 17:08:29 -05:00
Cong Wang
0e0eee2465 net: correct error path in rtnl_newlink()
I saw the following BUG when ->newlink() fails in rtnl_newlink():

[   40.240058] kernel BUG at net/core/dev.c:6438!

this is due to free_netdev() is not supposed to be called before
netdev is completely unregistered, therefore it is not correct
to call free_netdev() here, at least for ops->newlink!=NULL case,
many drivers call it in ->destructor so that rtnl_unlock() will
take care of it, we probably don't need to do anything here.

Cc: David S. Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-13 17:08:29 -05:00
Cong Wang
da37705cef macvlan: unregister net device when netdev_upper_dev_link() fails
rtnl_newlink() doesn't unregister it for us on failure.

Cc: Patrick McHardy <kaber@trash.net>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-13 17:08:28 -05:00
Dave Kleikamp
844fa1b5f8 jfs: set i_ctime when setting ACL
This fixes a regression in 3.14-rc1 where xfstests generic/307 fails.

jfs sets the ctime on the inode when writing an xattr. Previously,
jfs went ahead and stored an acl that can be completely represented
in the traditional permission bits, so the ctime was always set in
the xattr code. The new code doesn't bother storing the acl in that
case, thus the ctime isn't getting set.

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Reported-by: Michael L. Semon <mlsemon35@gmail.com>
2014-02-13 15:56:05 -06:00
Erik Hugne
64380a04de tipc: fix message corruption bug for deferred packets
If a packet received on a link is out-of-sequence, it will be
placed on a deferred queue and later reinserted in the receive
path once the preceding packets have been processed. The problem
with this is that it will be subject to the buffer adjustment from
link_recv_buf_validate twice. The second adjustment for 20 bytes
header space will corrupt the packet.

We solve this by tagging the deferred packets and bail out from
receive buffer validation for packets that have already been
subjected to this.

Signed-off-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-13 16:35:05 -05:00
Srinivas Kandagatla
d15891ca1f net: stmmac:sti: Add STi SOC glue driver.
STi series SOCs have a glue layer on top of the synopsis gmac IP, this
glue layer needs to be configured before the gmac driver starts using
the IP.

This patch adds a support to this glue layer which is configured via
stmmac setup, init, exit callbacks.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-13 16:25:13 -05:00
Thomas Gleixner
dd5fd9b91a tick: Clear broadcast pending bit when switching to oneshot
AMD systems which use the C1E workaround in the amd_e400_idle routine
trigger the WARN_ON_ONCE in the broadcast code when onlining a CPU.

The reason is that the idle routine of those AMD systems switches the
cpu into forced broadcast mode early on before the newly brought up
CPU can switch over to high resolution / NOHZ mode. The timer related
CPU1 bringup looks like this:

  clockevent_register_device(local_apic);
  tick_setup(local_apic);
  ...
  idle()
	tick_broadcast_on_off(FORCE);
	tick_broadcast_oneshot_control(ENTER)
	  cpumask_set(cpu, broadcast_oneshot_mask);
	halt();

Now the broadcast interrupt on CPU0 sets CPU1 in the
broadcast_pending_mask and wakes CPU1. So CPU1 continues:

	local_apic_timer_interrupt()
	   tick_handle_periodic();
	   softirq()
	     tick_init_highres();
	       cpumask_clr(cpu, broadcast_oneshot_mask);
	
	tick_broadcast_oneshot_control(ENTER)
	   WARN_ON(cpumask_test(cpu, broadcast_pending_mask);

So while we remove CPU1 from the broadcast_oneshot_mask when we switch
over to highres mode, we do not clear the pending bit, which then
triggers the warning when we go back to idle.

The reason why this is only visible on C1E affected AMD systems is
that the other machines enter the deep sleep states via
acpi_idle/intel_idle and exit the broadcast mode before executing the
remote triggered local_apic_timer_interrupt. So the pending bit is
already cleared when the switch over to highres mode is clearing the
oneshot mask.

The solution is simple: Clear the pending bit together with the mask
bit when we switch over to highres mode.

Stanislaw came up independently with the same patch by enforcing the
C1E workaround and debugging the fallout. I picked mine, because mine
has a changelog :)

Reported-by: poma <pomidorabelisima@gmail.com>
Debugged-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Olaf Hering <olaf@aepfle.de>
Cc: Dave Jones <davej@redhat.com>
Cc: Justin M. Forbes <jforbes@redhat.com>
Cc: Josh Boyer <jwboyer@redhat.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1402111434180.21991@ionos.tec.linutronix.de
Cc: stable@vger.kernel.org # 3.10+
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-02-13 21:55:54 +01:00
Jan Luebbe
c7966b525f net: fix macvtap type name in Kconfig
The netlink kind (and iproute2 type option) is actually called
'macvtap', not 'macvlan'.

Signed-off-by: Jan Luebbe <jlu@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-13 15:48:31 -05:00
Russell King - ARM Linux
4885c8731a hostap: fix "hostap: proc: Use remove_proc_subtree()"
remove_proc_subtree() doesn't work here as local->ddev has already
been removed, and NULLed out.  Use proc_remove() instead.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-02-13 14:58:12 -05:00
Stanislaw Gruszka
b6213e413a rtl8187: fix regression on MIPS without coherent DMA
This patch fixes regression caused by commit a16dad7763 "MIPS: Fix
potencial corruption". That commit fixes one corruption scenario in
cost of adding another one, which actually start to cause crashes
on Yeeloong laptop when rtl8187 driver is used.

For correct DMA read operation on machines without DMA coherence, kernel
have to invalidate cache, such it will refill later with new data that
device wrote to memory, when that data is needed to process. We can only
invalidate full cache line. Hence when cache line includes both dma
buffer and some other data (written in cache, but not yet in main
memory), the other data can not hit memory due to invalidation. That
happen on rtl8187 where struct rtl8187_priv fields are located just
before and after small buffers that are passed to USB layer and DMA
is performed on them.

To fix the problem we align buffers and reserve space after them to make
them match cache line.

This patch does not resolve all possible MIPS problems entirely, for
that we have to assure that we always map cache aligned buffers for DMA,
what can be complex or even not possible. But patch fixes visible and
reproducible regression and seems other possible corruptions do not
happen in practice, since Yeeloong laptop works stable without rtl8187
driver.

Bug report:
https://bugzilla.kernel.org/show_bug.cgi?id=54391

Reported-by: Petr Pisar <petr.pisar@atlas.cz>
Bisected-by: Tom Li <biergaizi2009@gmail.com>
Reported-and-tested-by: Tom Li <biergaizi2009@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Stanislaw Gruszka <stf_xl@wp.pl>
Acked-by: Larry Finger <Larry.Finger@lwfinger.next>
Acked-by: Hin-Tak Leung <htl10@users.sourceforge.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-02-13 14:58:12 -05:00
Dan Carpenter
4a0732d1f9 ath5k: shifting the wrong variable for AR5K_AR5210
In the original code we shift "AR5K_PHY(256) >> 28" which is zero but
the intent was to shift the return value of ath5k_hw_reg_read() like we
do a couple lines later.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-02-13 14:58:12 -05:00
Olivier Langlois
2e8c5e56b3 rtlwifi: Fix incorrect return from rtl_ps_enable_nic()
rtl_ps_enable_nic() is called from loops that will loop until this function returns true or a
maximum number of retries is performed.

hw_init() returns non-zero on error. In that situation return false to
restore the original design intent to retry hw init when it fails.

Signed-off-by: Olivier Langlois <olivier@trillion01.com>
Cc: Stable <stable@vger.kernel.org>
Acked-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-02-13 14:58:12 -05:00
Olivier Langlois
f78bccd79b rtlwifi: rtl8192ce: Fix too long disable of IRQs
rtl8192ce is disabling for too long the local interrupts during hw initiatialisation when performing scans

The observable symptoms in dmesg can be:

- underruns from ALSA playback
- clock freezes (tstamps do not change for several dmesg entries until irqs are finaly reenabled):

[  250.817669] rtlwifi:rtl_op_config():<0-0-0> 0x100
[  250.817685] rtl8192ce:_rtl92ce_phy_set_rf_power_state():<0-1-0> IPS Set eRf nic enable
[  250.817732] rtl8192ce:_rtl92ce_init_mac():<0-1-0> reg0xec:18051d59:11
[  250.817796] rtl8192ce:_rtl92ce_init_mac():<0-1-0> reg0xec:18051d59:11
[  250.817910] rtl8192ce:_rtl92ce_init_mac():<0-1-0> reg0xec:18051d59:11
[  250.818024] rtl8192ce:_rtl92ce_init_mac():<0-1-0> reg0xec:18051d59:11
[  250.818139] rtl8192ce:_rtl92ce_init_mac():<0-1-0> reg0xec:18051d59:11
[  250.818253] rtl8192ce:_rtl92ce_init_mac():<0-1-0> reg0xec:18051d59:11
[  250.818367] rtl8192ce:_rtl92ce_init_mac():<0-1-0> reg0xec:18051d59:11
[  250.818472] rtl8192ce:_rtl92ce_init_mac():<0-1-0> reg0xec:18051d59:11
[  250.818472] rtl8192ce:_rtl92ce_init_mac():<0-1-0> reg0xec:18051d59:11
[  250.818472] rtl8192ce:_rtl92ce_init_mac():<0-1-0> reg0xec:18051d59:11
[  250.818472] rtl8192ce:_rtl92ce_init_mac():<0-1-0> reg0xec:18051d59:11
[  250.818472] rtl8192ce:_rtl92ce_init_mac():<0-1-0> reg0xec:98053f15:10
[  250.818472] rtl8192ce:rtl92ce_sw_led_on():<0-1-0> LedAddr:4E ledpin=1
[  250.818472] rtl8192c_common:rtl92c_download_fw():<0-1-0> Firmware Version(49), Signature(0x88c1),Size(32)
[  250.818472] rtl8192ce:rtl92ce_enable_hw_security_config():<0-1-0> PairwiseEncAlgorithm = 0 GroupEncAlgorithm = 0
[  250.818472] rtl8192ce:rtl92ce_enable_hw_security_config():<0-1-0> The SECR-value cc
[  250.818472] rtl8192c_common:rtl92c_dm_check_txpower_tracking_thermal_meter():<0-1-0> Schedule TxPowerTracking direct call!!
[  250.818472] rtl8192c_common:rtl92c_dm_txpower_tracking_callback_thermalmeter():<0-1-0> rtl92c_dm_txpower_tracking_callback_thermalmeter
[  250.818472] rtl8192c_common:rtl92c_dm_txpower_tracking_callback_thermalmeter():<0-1-0> Readback Thermal Meter = 0xe pre thermal meter 0xf eeprom_thermalmeter 0xf
[  250.818472] rtl8192c_common:rtl92c_dm_txpower_tracking_callback_thermalmeter():<0-1-0> Initial pathA ele_d reg0xc80 = 0x40000000, ofdm_index=0xc
[  250.818472] rtl8192c_common:rtl92c_dm_txpower_tracking_callback_thermalmeter():<0-1-0> Initial reg0xa24 = 0x90e1317, cck_index=0xc, ch14 0
[  250.818472] rtl8192c_common:rtl92c_dm_txpower_tracking_callback_thermalmeter():<0-1-0> Readback Thermal Meter = 0xe pre thermal meter 0xf eeprom_thermalmeter 0xf delta 0x1 delta_lck 0x0 delta_iqk 0x0
[  250.818472] rtl8192c_common:rtl92c_dm_txpower_tracking_callback_thermalmeter():<0-1-0> <===
[  250.818472] rtl8192c_common:rtl92c_dm_initialize_txpower_tracking_thermalmeter():<0-1-0> pMgntInfo->txpower_tracking = 1
[  250.818472] rtl8192ce:rtl92ce_led_control():<0-1-0> ledaction 3
[  250.818472] rtl8192ce:rtl92ce_sw_led_on():<0-1-0> LedAddr:4E ledpin=1
[  250.818472] rtlwifi:rtl_ips_nic_on():<0-1-0> before spin_unlock_irqrestore
[  251.154656] PCM: Lost interrupts? [Q]-0 (stream=0, delta=15903, new_hw_ptr=293408, old_hw_ptr=277505)

The exact code flow that causes that is:

1. wpa_supplicant send a start_scan request to the nl80211 driver
2. mac80211 module call rtl_op_config with IEEE80211_CONF_CHANGE_IDLE
3.   rtl_ips_nic_on is called which disable local irqs
4.     rtl92c_phy_set_rf_power_state() is called
5.       rtl_ps_enable_nic() is called and hw_init()is executed and then the interrupts on the device are enabled

A good solution could be to refactor the code to avoid calling rtl92ce_hw_init() with the irqs disabled
but a quick and dirty solution that has proven to work is
to reenable the irqs during the function rtl92ce_hw_init().

I think that it is safe doing so since the device interrupt will only be enabled after the init function succeed.

Signed-off-by: Olivier Langlois <olivier@trillion01.com>
Cc: Stable <stable@vger.kernel.org>
Acked-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-02-13 14:58:12 -05:00
John W. Linville
6b8a3ecf30 Merge git://git.kernel.org/pub/scm/linux/kernel/git/iwlwifi/iwlwifi-fixes 2014-02-13 14:56:22 -05:00
NeilBrown
2ec197db1a lockd: send correct lock when granting a delayed lock.
If an NFS client attempts to get a lock (using NLM) and the lock is
not available, the server will remember the request and when the lock
becomes available it will send a GRANT request to the client to
provide the lock.

If the client already held an adjacent lock, the GRANT callback will
report the union of the existing and new locks, which can confuse the
client.

This happens because __posix_lock_file (called by vfs_lock_file)
updates the passed-in file_lock structure when adjacent or
over-lapping locks are found.

To avoid this problem we take a copy of the two fields that can
be changed (fl_start and fl_end) before the call and restore them
afterwards.
An alternate would be to allocate a 'struct file_lock', initialise it,
use locks_copy_lock() to take a copy, then locks_release_private()
after the vfs_lock_file() call.  But that is a lot more work.

Reported-by: Olaf Kirch <okir@suse.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

--
v1 had a couple of issues (large on-stack struct and didn't really work properly).
This version is much better tested.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-02-13 14:55:02 -05:00
Dave Jones
71c68c4fc9 drm/i2c: tda998x: Fix memory leak in tda998x_encoder_init error path.
Commit 6ae668cc19 (drm/i2c: tda998x: check the CEC device creation)
introduced a memory leak in the error path of tda998x_encoder_init

Picked up by the nightly Coverity scan. CID 1174076

Signed-off-by: Dave Jones <davej@fedoraproject.org>
Acked-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-02-13 19:40:24 +00:00
Petr Písař
0930b0950a vt: Fix secure clear screen
\E[3J console code (secure clear screen) needs to update_screen(vc)
in order to write-through blanks into off-screen video memory.

This has been removed accidentally in 3.6 by:

commit 81732c3b2f
Author: Jean-François Moine <moinejf@free.fr>
Date:   Thu Sep 6 19:24:13 2012 +0200

    tty vt: Fix line garbage in virtual console on command line edition

Signed-off-by: Petr Písař <petr.pisar@atlas.cz>
Cc: stable <stable@vger.kernel.org> # 3.6
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-13 11:12:00 -08:00
Joe Schultz
45a7bd6359 serial: 8250: Support XR17V35x fraction divisor
The Exar XR17V35x family of UARTs have an additional fractional divisor
register (DLD) which was not being used. Calculate and set this
register for these devices to reduce their baud rate error.

Signed-off-by: Joe Schultz <jschultz@xes-inc.com>
Signed-off-by: Aaron Sierra <asierra@xes-inc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-13 10:02:19 -08:00
Peter Hurley
e2613be509 n_tty: Fix stale echo output
When echoes cannot be flushed to output (usually because the tty
has no more write room) and L_ECHO is subsequently turned off, then
when L_ECHO is turned back on, stale echoes are output.

Output completed echoes regardless of the L_ECHO setting:
  1. before normal writes to that tty
  2. if the tty was stopped by soft flow control and is being
     restarted

Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: <stable@vger.kernel.org> # 3.13.x
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-13 10:02:19 -08:00
Qipan Li
fb78b81142 serial: sirf: fix kernel panic caused by unpaired spinlock
commit 8b9ade9f74 coming from Viresh Kumar "tty: serial: sirfsoc: drop
uart_port->lock before calling tty_flip_buffer_push()" broke sirfsoc uart
driver by knic:

	[    5.129122] BUG: spinlock already unlocked on CPU#0, ip6tables/1331
	[    5.132554]  lock: sirfsoc_uart_ports+0x4/0x8a0, .magic: dead4ead,
	.owner: <none>/-1, .owner_cpu: -1
	[    5.141651] CPU: 0 PID: 1331 Comm: ip6tables Tainted: G
	W  O 3.10.16 #3
	[    5.148866] [<c0013528>] (unwind_backtrace+0x0/0xe0) from
	[<c0010e70>] (show_stack+0x10/0x14)
	[    5.157362] [<c0010e70>] (show_stack+0x10/0x14) from
	[<c01a5e68>] (do_raw_spin_unlock+0x40/0xc8)
	[    5.166125] [<c01a5e68>] (do_raw_spin_unlock+0x40/0xc8) from
	[<c03ff8b4>] (_raw_spin_unlock+0x8/0x40)
	[    5.175322] [<c03ff8b4>] (_raw_spin_unlock+0x8/0x40) from
	[<c0203fcc>] (sirfsoc_uart_pio_rx_chars+0xa4/0xc0)
	[    5.185120] [<c0203fcc>]
	(sirfsoc_uart_pio_rx_chars+0xa4/0xc0) from [<c0204fb8>]
	(sirfsoc_rx_tmo_process_tl+0xdc/0x1e0)
	[    5.195875] [<c0204fb8>]
	(sirfsoc_rx_tmo_process_tl+0xdc/0x1e0) from [<c0024b50>]
	(tasklet_action+0x8c/0xec)
	[    5.205673] [<c0024b50>] (tasklet_action+0x8c/0xec) from
	[<c00242a8>] (__do_softirq+0xec/0x1d4)
	[    5.214347] [<c00242a8>] (__do_softirq+0xec/0x1d4) from
	[<c0024428>] (do_softirq+0x48/0x54)
	[    5.222674] [<c0024428>] (do_softirq+0x48/0x54) from
	[<c0024690>] (irq_exit+0x74/0xc0)
	[    5.230573] [<c0024690>] (irq_exit+0x74/0xc0) from
	[<c000e1e8>] (handle_IRQ+0x6c/0x90)
	[    5.238465] [<c000e1e8>] (handle_IRQ+0x6c/0x90) from
	[<c000d500>] (__irq_svc+0x40/0x70)
	[    5.246446] [<c000d500>] (__irq_svc+0x40/0x70) from
	[<c0092e7c>] (mark_page_accessed+0xc/0x68)
	[    5.255034] [<c0092e7c>] (mark_page_accessed+0xc/0x68) from
	[<c00a2a4c>] (unmap_single_vma+0x3bc/0x550)
	[    5.264402] [<c00a2a4c>] (unmap_single_vma+0x3bc/0x550) from
	[<c00a3b4c>] (unmap_vmas+0x44/0x54)
	[    5.273164] [<c00a3b4c>] (unmap_vmas+0x44/0x54) from
	[<c00a81a8>] (exit_mmap+0xc4/0x1e0)
	[    5.281233] [<c00a81a8>] (exit_mmap+0xc4/0x1e0) from
	[<c001bb78>] (mmput+0x3c/0xdc)
	[    5.288868] [<c001bb78>] (mmput+0x3c/0xdc) from [<c0021b0c>]
	(do_exit+0x30c/0x828)
	[    5.296413] [<c0021b0c>] (do_exit+0x30c/0x828) from
	[<c0022dac>] (do_group_exit+0x4c/0xb0)
	[    5.304653] [<c0022dac>] (do_group_exit+0x4c/0xb0) from
	[<c0022e20>] (__wake_up_parent+0x0/0x18)

Root cause:
the commit dropped uart_port->lock before calling tty_flip_buffer_push(), but in sirfsoc-uart,
sirfsoc_uart_pio_rx_chars() can be called by sirfsoc_rx_tmo_process_tl(). here uart_port->lock
has not been taken yet. so that caused unpaired lock/unlock.

Solution:
This patch is doing a quick fix for that, it adds spin_lock/unlock(&port->lock) protect to
sirfsoc_uart_pio_rx_chars() in sirfsoc_rx_tmo_process_tl() to keep spin_lock/unlock in pair.

Signed-off-by: Qipan Li <Qipan.Li@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Cc: stable <stable@vger.kernel.org> # 3.12
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-13 10:02:19 -08:00
Dmitry Eremin-Solenikov
333c085e4b serial: 8250_pci: unbreak last serial ports on NetMos 9865 cards
Aparently 9865 uses standard BAR encoding scheme (unlike 99xx cards).
Current pci_netmos_9900_setup() uses wrong BAR indices for the 9865 PCI
device, function 2. Using standard BAR indices makes all 6 ports work
for me. Thus disable the NetMos 9900 quirk for NetMos 9865 pci device.

For the reference, here is the relevant part of lspci for my device:

02:07.0 Serial controller: MosChip Semiconductor Technology Ltd. PCI
9865 Multi-I/O Controller (prog-if 02 [16550])
	Subsystem: Device a000:1000
	Flags: bus master, medium devsel, latency 32, IRQ 17
	I/O ports at ac00 [size=8]
	Memory at fcfff000 (32-bit, non-prefetchable) [size=4K]
	Memory at fcffe000 (32-bit, non-prefetchable) [size=4K]
	Capabilities: [48] Power Management version 2
	Kernel driver in use: serial

02:07.1 Serial controller: MosChip Semiconductor Technology Ltd. PCI
9865 Multi-I/O Controller (prog-if 02 [16550])
	Subsystem: Device a000:1000
	Flags: bus master, medium devsel, latency 32, IRQ 18
	I/O ports at a800 [size=8]
	Memory at fcffd000 (32-bit, non-prefetchable) [size=4K]
	Memory at fcffc000 (32-bit, non-prefetchable) [size=4K]
	Capabilities: [48] Power Management version 2
	Kernel driver in use: serial

02:07.2 Communication controller: MosChip Semiconductor Technology Ltd.
PCI 9865 Multi-I/O Controller
	Subsystem: Device a000:3004
	Flags: bus master, medium devsel, latency 32, IRQ 19
	I/O ports at a400 [size=8]
	I/O ports at a000 [size=8]
	I/O ports at 9c00 [size=8]
	I/O ports at 9800 [size=8]
	Memory at fcffb000 (32-bit, non-prefetchable) [size=4K]
	Capabilities: [48] Power Management version 2
	Kernel driver in use: serial

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-13 09:57:33 -08:00
Peter Hurley
a5934804a8 n_tty: Fix poll() when TIME_CHAR and MIN_CHAR == 0
Commit eafbe67f84,
  n_tty: Refactor input_available_p() by call site
broke poll() when TIME_CHAR(tty) and MIN_CHAR(tty) are both 0.

When TIME_CHAR and MIN_CHAR are both 0, input is available if the
read_cnt is 1 (not 0).

Reported-by: Eric Dumazet <edumazet@google.com>
Tested-by: Eric Dumazet <edumazet@google.com>
Reported-by: Stephane Eranian <eranian@google.com>
Tested-by: David Ahern <dsahern@gmail.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-13 09:57:33 -08:00
Michael Grzeschik
a64c1a1c75 serial: omap: fix rs485 probe on defered pinctrl
If the gpio is not yet available we better also
defer the probing in the rs485 case.

Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-13 09:57:33 -08:00
Mika Westerberg
13b949f03e serial: 8250_dw: fix compilation warning when !CONFIG_PM_SLEEP
CONFIG_PM will be set if either or both CONFIG_PM_SLEEP and
CONFIG_PM_RUNTIME is set. Compiling the driver with !CONFIG_PM_SLEEP causes
following compilation warnings:

drivers/tty/serial/8250/8250_dw.c:404:12: warning: ‘dw8250_suspend’ defined but not used [-Wunused-function]
drivers/tty/serial/8250/8250_dw.c:413:12: warning: ‘dw8250_resume’ defined but not used [-Wunused-function]

Fix this by using CONFIG_PM_SLEEP instead.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-13 09:57:33 -08:00
Markus Pargmann
ce6acca65e serial: omap-serial: Move info message to probe function
Currently the info message about a missing wakeirq for uart is printed
every time the serial driver's startup function is called. This happens
multiple times and not just once.

This can cause lots of extra messages at boot time, slowing things down.  It is
caused by commit 2a0b965cfb (serial: omap: Add support for optional wake-up)
which was applied for v3.13-rc1.

This patch moves the infomessage to the probe function to display it
only once.

Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: stable <stable@vger.kernel.org> # 3.13
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-13 09:56:08 -08:00
Matan Barak
4196670be7 IB/mlx4: Don't allocate range of steerable UD QPs for Ethernet-only device
When the device has only Ethernet ports, don't try to allocate range
of steerable UD QPs since they aren't needed.  This fixes an issue
where mlx4 VFs tried to allocate a range of UD steerable QPs, but
failed to do so.

Fixes: c1c9850112 ("IB/mlx4: Add support for steerable IB UD QPs")
Signed-off-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-02-13 09:00:18 -08:00
H. Peter Anvin
4640c7ee9b x86, smap: smap_violation() is bogus if CONFIG_X86_SMAP is off
If CONFIG_X86_SMAP is disabled, smap_violation() tests for conditions
which are incorrect (as the AC flag doesn't matter), causing spurious
faults.

The dynamic disabling of SMAP (nosmap on the command line) is fine
because it disables X86_FEATURE_SMAP, therefore causing the
static_cpu_has() to return false.

Found by Fengguang Wu's test system.

[ v3: move all predicates into smap_violation() ]
[ v2: use IS_ENABLED() instead of #ifdef ]

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Link: http://lkml.kernel.org/r/20140213124550.GA30497@localhost
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@vger.kernel.org> # v3.7+
2014-02-13 08:40:52 -08:00
H. Peter Anvin
03bbd596ac x86, smap: Don't enable SMAP if CONFIG_X86_SMAP is disabled
If SMAP support is not compiled into the kernel, don't enable SMAP in
CR4 -- in fact, we should clear it, because the kernel doesn't contain
the proper STAC/CLAC instructions for SMAP support.

Found by Fengguang Wu's test system.

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Link: http://lkml.kernel.org/r/20140213124550.GA30497@localhost
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@vger.kernel.org> # v3.7+
2014-02-13 07:50:25 -08:00
Jani Nikula
f51a44b9a6 drm/i915/dp: add native aux defer retry limit
Retrying indefinitely places too much trust on the aux implementation of
the sink devices.

Reported-by: Daniel Martin <consume.noise@gmail.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=71267
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Cc: stable@vger.kernel.org
Tested-by: Theodore Ts'o <tytso@mit.edu>
Tested-by: Sree Harsha Totakura <freedesktop@h.totakura.in>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2014-02-13 16:12:42 +01:00
Jani Nikula
04eada25d1 drm/i915/dp: increase native aux defer retry timeout
Give more slack to sink devices before retrying on native aux
defer. AFAICT the 100 us timeout was not based on the DP spec.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Cc: stable@vger.kernel.org (on Jani's request)
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2014-02-13 16:05:33 +01:00
Emmanuel Grumbach
205e2210da iwlwifi: disable TX AMPDU by default for iwldvm
NICs supported by iwldvm don't handle well TX AMPDU.
Disable it by default, still leave the possibility to
the user to force enable it with a debug parameter.

NICs supported by iwlmvm don't suffer from the same issue,
leave TX AMPDU enabled by default for these.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
2014-02-13 15:24:35 +02:00
Steven Noonan
a9f180345f compiler/gcc4: Make quirk for asm_volatile_goto() unconditional
I started noticing problems with KVM guest destruction on Linux
3.12+, where guest memory wasn't being cleaned up. I bisected it
down to the commit introducing the new 'asm goto'-based atomics,
and found this quirk was later applied to those.

Unfortunately, even with GCC 4.8.2 (which ostensibly fixed the
known 'asm goto' bug) I am still getting some kind of
miscompilation. If I enable the asm_volatile_goto quirk for my
compiler, KVM guests are destroyed correctly and the memory is
cleaned up.

So make the quirk unconditional for now, until bug is found
and fixed.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Steven Noonan <steven@uplinklabs.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Jakub Jelinek <jakub@redhat.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/1392274867-15236-1-git-send-email-steven@uplinklabs.net
Link: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-02-13 12:34:05 +01:00
Sumit Semwal
c0b00a525c dma-buf: update debugfs output
Russell King observed 'wierd' looking output from debugfs, and also suggested
better ways of getting device names (use KBUILD_MODNAME, dev_name())

This patch addresses these issues to make the debugfs output correct and better
looking.

While at it, replace seq_printf with seq_puts to remove the checkpatch.pl
warnings.

Reported-by: Russell King - ARM Linux <linux@arm.linux.org.uk>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
2014-02-13 10:08:52 +05:30
Oleg Nesterov
789b5e0315 md/raid5: Fix CPU hotplug callback registration
Subsystems that want to register CPU hotplug callbacks, as well as perform
initialization for the CPUs that are already online, often do it as shown
below:

	get_online_cpus();

	for_each_online_cpu(cpu)
		init_cpu(cpu);

	register_cpu_notifier(&foobar_cpu_notifier);

	put_online_cpus();

This is wrong, since it is prone to ABBA deadlocks involving the
cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently
with CPU hotplug operations).

Interestingly, the raid5 code can actually prevent double initialization and
hence can use the following simplified form of callback registration:

	register_cpu_notifier(&foobar_cpu_notifier);

	get_online_cpus();

	for_each_online_cpu(cpu)
		init_cpu(cpu);

	put_online_cpus();

A hotplug operation that occurs between registering the notifier and calling
get_online_cpus(), won't disrupt anything, because the code takes care to
perform the memory allocations only once.

So reorganize the code in raid5 this way to fix the deadlock with callback
registration.

Cc: linux-raid@vger.kernel.org
Cc: stable@vger.kernel.org (v2.6.32+)
Fixes: 36d1c6476b
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
[Srivatsa: Fixed the unregister_cpu_notifier() deadlock, added the
free_scratch_buffer() helper to condense code further and wrote the changelog.]
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2014-02-13 13:46:45 +11:00
Rafael J. Wysocki
465e5fc41d Merge branch 'pm-cpufreq'
* pm-cpufreq:
  MAINTAINERS / cpufreq: update Sudeep's email address
  intel_pstate: Remove energy reporting from pstate_sample tracepoint
2014-02-13 02:12:41 +01:00
Sudeep Holla
171d0ba869 MAINTAINERS / cpufreq: update Sudeep's email address
Though my old email address continues to work as alias, updating
to the new address as it's shorter, easier and more appropriate.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-02-13 02:11:32 +01:00
Dirk Brandewie
709c078e17 intel_pstate: Remove energy reporting from pstate_sample tracepoint
Remove the reporting of energy since it does not provide any useful
information about the state of the driver and will be a maintainance
headache going forward since the RAPL energy units register is not
architectural and subject to change between micro-architectures

References: https://bugzilla.kernel.org/show_bug.cgi?id=69831
Fixes: b69880f9cc (intel_pstate: Add trace point to report internal state.)
Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-02-13 02:11:18 +01:00
Olof Johansson
31fd8f5b89 dma: mv_xor: Silence a bunch of LPAE-related warnings
Enabling some of the mvebu platforms in the multiplatform config for ARM
enabled these drivers, which also triggered a bunch of warnings when LPAE
is enabled (thus making phys_addr_t 64-bit).

Most changes are switching printk formats, but also a bit of changes to what
used to be array-based pointer arithmetic that could just be done with the
address types instead.

The warnings were:

drivers/dma/mv_xor.c: In function 'mv_xor_tx_submit':
drivers/dma/mv_xor.c:500:3: warning: format '%x' expects argument of type
    'unsigned int', but argument 4 has type 'dma_addr_t' [-Wformat]
drivers/dma/mv_xor.c: In function 'mv_xor_alloc_chan_resources':
drivers/dma/mv_xor.c:553:13: warning: cast to pointer from integer of
    different size [-Wint-to-pointer-cast]
drivers/dma/mv_xor.c:555:4: warning: cast from pointer to integer of
    different size [-Wpointer-to-int-cast]
drivers/dma/mv_xor.c: In function 'mv_xor_prep_dma_memcpy':
drivers/dma/mv_xor.c:584:2: warning: format '%x' expects argument of type
    'unsigned int', but argument 5 has type 'dma_addr_t' [-Wformat]
drivers/dma/mv_xor.c:584:2: warning: format '%x' expects argument of type
    'unsigned int', but argument 6 has type 'dma_addr_t' [-Wformat]
drivers/dma/mv_xor.c: In function 'mv_xor_prep_dma_xor':
drivers/dma/mv_xor.c:628:2: warning: format '%u' expects argument of type
    'unsigned int', but argument 7 has type 'dma_addr_t' [-Wformat]

Acked-by: Vinod Koul <vinod.koul@intel.com>
Acked-by: Jason Cooper <jason@lakedaemon.net>
Signed-off-by: Olof Johansson <olof@lixom.net>
2014-02-12 16:21:17 -08:00
Tejun Heo
1a11533fbd Revert "cgroup: use an ordered workqueue for cgroup destruction"
This reverts commit ab3f5faa62.
Explanation from Hugh:

  It's because more thorough testing, by others here, found that it
  wasn't always solving the problem: so I asked Tejun privately to
  hold off from sending it in, until we'd worked out why not.

  Most of our testing being on a v3,11-based kernel, it was perfectly
  possible that the problem was merely our own e.g. missing Tejun's
  8a2b753844 ("workqueue: fix ordered workqueues in NUMA setups").

  But that turned out not to be enough to fix it either. Then Filipe
  pointed out how percpu_ref_kill_and_confirm() uses call_rcu_sched()
  before we ever get to put the offline on to the workqueue: by the
  time we get to the workqueue, the ordering has already been lost.

  So, thanks for the Acks, but I'm afraid that this ordered workqueue
  solution is just not good enough: we should simply forget that patch
  and provide a different answer."

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
2014-02-12 19:08:28 -05:00