This bug was reported by Steinar H. Gunderson and was introduced by commit
f7cb888633 ("sit/gre6: don't try to add the same route two times").
root@morgental:~# ip tunnel add foo mode gre remote 1.2.3.4 ttl 64
root@morgental:~# ip link set foo up mtu 1468
root@morgental:~# ip -6 route show dev foo
fe80::/64 proto kernel metric 256
but after the above commit, no such route shows up.
There is no link local route because dev->dev_addr is 0 (because local ipv4
address is 0), hence no link local address is configured.
In this scenario, the link local address is added manually: 'ip -6 addr add
fe80::1 dev foo' and because prefix is /128, no link local route is added by the
kernel.
Even if the right things to do is to add the link local address with a /64
prefix, we need to restore the previous behavior to avoid breaking userpace.
Reported-by: Steinar H. Gunderson <sesse@samfundet.no>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Mathias reported that on an AMD Geode LX embedded board (ALiX)
with ath9k driver PACKET_QDISC_BYPASS, introduced in commit
d346a3fae3 ("packet: introduce PACKET_QDISC_BYPASS socket
option"), triggers a WARN_ON() coming from the driver itself
via 066dae93bd ("ath9k: rework tx queue selection and fix
queue stopping/waking").
The reason why this happened is that ndo_select_queue() call
is not invoked from direct xmit path i.e. for ieee80211 subsystem
that sets queue and TID (similar to 802.1d tag) which is being
put into the frame through 802.11e (WMM, QoS). If that is not
set, pending frame counter for e.g. ath9k can get messed up.
So the WARN_ON() in ath9k is absolutely legitimate. Generally,
the hw queue selection in ieee80211 depends on the type of
traffic, and priorities are set according to ieee80211_ac_numbers
mapping; working in a similar way as DiffServ only on a lower
layer, so that the AP can favour frames that have "real-time"
requirements like voice or video data frames.
Therefore, check for presence of ndo_select_queue() in netdev
ops and, if available, invoke it with a fallback handler to
__packet_pick_tx_queue(), so that driver such as bnx2x, ixgbe,
or mlx4 can still select a hw queue for transmission in
relation to the current CPU while e.g. ieee80211 subsystem
can make their own choices.
Reported-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In order to allow users to invoke netdev_cap_txqueue, it needs to
be moved into netdevice.h header file. While at it, also add kernel
doc header to document the API.
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a new argument for ndo_select_queue() callback that passes a
fallback handler. This gets invoked through netdev_pick_tx();
fallback handler is currently __netdev_pick_tx() as most drivers
invoke this function within their customized implementation in
case for skbs that don't need any special handling. This fallback
handler can then be replaced on other call-sites with different
queue selection methods (e.g. in packet sockets, pktgen etc).
This also has the nice side-effect that __netdev_pick_tx() is
then only invoked from netdev_pick_tx() and export of that
function to modules can be undone.
Suggested-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Otherwise the device is not completely shut down.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Implementation of (a)rwnd calculation might lead to severe performance issues
and associations completely stalling. These problems are described and solution
is proposed which improves lksctp's robustness in congestion state.
1) Sudden drop of a_rwnd and incomplete window recovery afterwards
Data accounted in sctp_assoc_rwnd_decrease takes only payload size (sctp data),
but size of sk_buff, which is blamed against receiver buffer, is not accounted
in rwnd. Theoretically, this should not be the problem as actual size of buffer
is double the amount requested on the socket (SO_RECVBUF). Problem here is
that this will have bad scaling for data which is less then sizeof sk_buff.
E.g. in 4G (LTE) networks, link interfacing radio side will have a large portion
of traffic of this size (less then 100B).
An example of sudden drop and incomplete window recovery is given below. Node B
exhibits problematic behavior. Node A initiates association and B is configured
to advertise rwnd of 10000. A sends messages of size 43B (size of typical sctp
message in 4G (LTE) network). On B data is left in buffer by not reading socket
in userspace.
Lets examine when we will hit pressure state and declare rwnd to be 0 for
scenario with above stated parameters (rwnd == 10000, chunk size == 43, each
chunk is sent in separate sctp packet)
Logic is implemented in sctp_assoc_rwnd_decrease:
socket_buffer (see below) is maximum size which can be held in socket buffer
(sk_rcvbuf). current_alloced is amount of data currently allocated (rx_count)
A simple expression is given for which it will be examined after how many
packets for above stated parameters we enter pressure state:
We start by condition which has to be met in order to enter pressure state:
socket_buffer < currently_alloced;
currently_alloced is represented as size of sctp packets received so far and not
yet delivered to userspace. x is the number of chunks/packets (since there is no
bundling, and each chunk is delivered in separate packet, we can observe each
chunk also as sctp packet, and what is important here, having its own sk_buff):
socket_buffer < x*each_sctp_packet;
each_sctp_packet is sctp chunk size + sizeof(struct sk_buff). socket_buffer is
twice the amount of initially requested size of socket buffer, which is in case
of sctp, twice the a_rwnd requested:
2*rwnd < x*(payload+sizeof(struc sk_buff));
sizeof(struct sk_buff) is 190 (3.13.0-rc4+). Above is stated that rwnd is 10000
and each payload size is 43
20000 < x(43+190);
x > 20000/233;
x ~> 84;
After ~84 messages, pressure state is entered and 0 rwnd is advertised while
received 84*43B ~= 3612B sctp data. This is why external observer notices sudden
drop from 6474 to 0, as it will be now shown in example:
IP A.34340 > B.12345: sctp (1) [INIT] [init tag: 1875509148] [rwnd: 81920] [OS: 10] [MIS: 65535] [init TSN: 1096057017]
IP B.12345 > A.34340: sctp (1) [INIT ACK] [init tag: 3198966556] [rwnd: 10000] [OS: 10] [MIS: 10] [init TSN: 902132839]
IP A.34340 > B.12345: sctp (1) [COOKIE ECHO]
IP B.12345 > A.34340: sctp (1) [COOKIE ACK]
IP A.34340 > B.12345: sctp (1) [DATA] (B)(E) [TSN: 1096057017] [SID: 0] [SSEQ 0] [PPID 0x18]
IP B.12345 > A.34340: sctp (1) [SACK] [cum ack 1096057017] [a_rwnd 9957] [#gap acks 0] [#dup tsns 0]
IP A.34340 > B.12345: sctp (1) [DATA] (B)(E) [TSN: 1096057018] [SID: 0] [SSEQ 1] [PPID 0x18]
IP B.12345 > A.34340: sctp (1) [SACK] [cum ack 1096057018] [a_rwnd 9957] [#gap acks 0] [#dup tsns 0]
IP A.34340 > B.12345: sctp (1) [DATA] (B)(E) [TSN: 1096057019] [SID: 0] [SSEQ 2] [PPID 0x18]
IP B.12345 > A.34340: sctp (1) [SACK] [cum ack 1096057019] [a_rwnd 9914] [#gap acks 0] [#dup tsns 0]
<...>
IP A.34340 > B.12345: sctp (1) [DATA] (B)(E) [TSN: 1096057098] [SID: 0] [SSEQ 81] [PPID 0x18]
IP B.12345 > A.34340: sctp (1) [SACK] [cum ack 1096057098] [a_rwnd 6517] [#gap acks 0] [#dup tsns 0]
IP A.34340 > B.12345: sctp (1) [DATA] (B)(E) [TSN: 1096057099] [SID: 0] [SSEQ 82] [PPID 0x18]
IP B.12345 > A.34340: sctp (1) [SACK] [cum ack 1096057099] [a_rwnd 6474] [#gap acks 0] [#dup tsns 0]
IP A.34340 > B.12345: sctp (1) [DATA] (B)(E) [TSN: 1096057100] [SID: 0] [SSEQ 83] [PPID 0x18]
--> Sudden drop
IP B.12345 > A.34340: sctp (1) [SACK] [cum ack 1096057100] [a_rwnd 0] [#gap acks 0] [#dup tsns 0]
At this point, rwnd_press stores current rwnd value so it can be later restored
in sctp_assoc_rwnd_increase. This however doesn't happen as condition to start
slowly increasing rwnd until rwnd_press is returned to rwnd is never met. This
condition is not met since rwnd, after it hit 0, must first reach rwnd_press by
adding amount which is read from userspace. Let us observe values in above
example. Initial a_rwnd is 10000, pressure was hit when rwnd was ~6500 and the
amount of actual sctp data currently waiting to be delivered to userspace
is ~3500. When userspace starts to read, sctp_assoc_rwnd_increase will be blamed
only for sctp data, which is ~3500. Condition is never met, and when userspace
reads all data, rwnd stays on 3569.
IP B.12345 > A.34340: sctp (1) [SACK] [cum ack 1096057100] [a_rwnd 1505] [#gap acks 0] [#dup tsns 0]
IP B.12345 > A.34340: sctp (1) [SACK] [cum ack 1096057100] [a_rwnd 3010] [#gap acks 0] [#dup tsns 0]
IP A.34340 > B.12345: sctp (1) [DATA] (B)(E) [TSN: 1096057101] [SID: 0] [SSEQ 84] [PPID 0x18]
IP B.12345 > A.34340: sctp (1) [SACK] [cum ack 1096057101] [a_rwnd 3569] [#gap acks 0] [#dup tsns 0]
--> At this point userspace read everything, rwnd recovered only to 3569
IP A.34340 > B.12345: sctp (1) [DATA] (B)(E) [TSN: 1096057102] [SID: 0] [SSEQ 85] [PPID 0x18]
IP B.12345 > A.34340: sctp (1) [SACK] [cum ack 1096057102] [a_rwnd 3569] [#gap acks 0] [#dup tsns 0]
Reproduction is straight forward, it is enough for sender to send packets of
size less then sizeof(struct sk_buff) and receiver keeping them in its buffers.
2) Minute size window for associations sharing the same socket buffer
In case multiple associations share the same socket, and same socket buffer
(sctp.rcvbuf_policy == 0), different scenarios exist in which congestion on one
of the associations can permanently drop rwnd of other association(s).
Situation will be typically observed as one association suddenly having rwnd
dropped to size of last packet received and never recovering beyond that point.
Different scenarios will lead to it, but all have in common that one of the
associations (let it be association from 1)) nearly depleted socket buffer, and
the other association blames socket buffer just for the amount enough to start
the pressure. This association will enter pressure state, set rwnd_press and
announce 0 rwnd.
When data is read by userspace, similar situation as in 1) will occur, rwnd will
increase just for the size read by userspace but rwnd_press will be high enough
so that association doesn't have enough credit to reach rwnd_press and restore
to previous state. This case is special case of 1), being worse as there is, in
the worst case, only one packet in buffer for which size rwnd will be increased.
Consequence is association which has very low maximum rwnd ('minute size', in
our case down to 43B - size of packet which caused pressure) and as such
unusable.
Scenario happened in the field and labs frequently after congestion state (link
breaks, different probabilities of packet drop, packet reordering) and with
scenario 1) preceding. Here is given a deterministic scenario for reproduction:
>From node A establish two associations on the same socket, with rcvbuf_policy
being set to share one common buffer (sctp.rcvbuf_policy == 0). On association 1
repeat scenario from 1), that is, bring it down to 0 and restore up. Observe
scenario 1). Use small payload size (here we use 43). Once rwnd is 'recovered',
bring it down close to 0, as in just one more packet would close it. This has as
a consequence that association number 2 is able to receive (at least) one more
packet which will bring it in pressure state. E.g. if association 2 had rwnd of
10000, packet received was 43, and we enter at this point into pressure,
rwnd_press will have 9957. Once payload is delivered to userspace, rwnd will
increase for 43, but conditions to restore rwnd to original state, just as in
1), will never be satisfied.
--> Association 1, between A.y and B.12345
IP A.55915 > B.12345: sctp (1) [INIT] [init tag: 836880897] [rwnd: 10000] [OS: 10] [MIS: 65535] [init TSN: 4032536569]
IP B.12345 > A.55915: sctp (1) [INIT ACK] [init tag: 2873310749] [rwnd: 81920] [OS: 10] [MIS: 10] [init TSN: 3799315613]
IP A.55915 > B.12345: sctp (1) [COOKIE ECHO]
IP B.12345 > A.55915: sctp (1) [COOKIE ACK]
--> Association 2, between A.z and B.12346
IP A.55915 > B.12346: sctp (1) [INIT] [init tag: 534798321] [rwnd: 10000] [OS: 10] [MIS: 65535] [init TSN: 2099285173]
IP B.12346 > A.55915: sctp (1) [INIT ACK] [init tag: 516668823] [rwnd: 81920] [OS: 10] [MIS: 10] [init TSN: 3676403240]
IP A.55915 > B.12346: sctp (1) [COOKIE ECHO]
IP B.12346 > A.55915: sctp (1) [COOKIE ACK]
--> Deplete socket buffer by sending messages of size 43B over association 1
IP B.12345 > A.55915: sctp (1) [DATA] (B)(E) [TSN: 3799315613] [SID: 0] [SSEQ 0] [PPID 0x18]
IP A.55915 > B.12345: sctp (1) [SACK] [cum ack 3799315613] [a_rwnd 9957] [#gap acks 0] [#dup tsns 0]
<...>
IP A.55915 > B.12345: sctp (1) [SACK] [cum ack 3799315696] [a_rwnd 6388] [#gap acks 0] [#dup tsns 0]
IP B.12345 > A.55915: sctp (1) [DATA] (B)(E) [TSN: 3799315697] [SID: 0] [SSEQ 84] [PPID 0x18]
IP A.55915 > B.12345: sctp (1) [SACK] [cum ack 3799315697] [a_rwnd 6345] [#gap acks 0] [#dup tsns 0]
--> Sudden drop on 1
IP B.12345 > A.55915: sctp (1) [DATA] (B)(E) [TSN: 3799315698] [SID: 0] [SSEQ 85] [PPID 0x18]
IP A.55915 > B.12345: sctp (1) [SACK] [cum ack 3799315698] [a_rwnd 0] [#gap acks 0] [#dup tsns 0]
--> Here userspace read, rwnd 'recovered' to 3698, now deplete again using
association 1 so there is place in buffer for only one more packet
IP B.12345 > A.55915: sctp (1) [DATA] (B)(E) [TSN: 3799315799] [SID: 0] [SSEQ 186] [PPID 0x18]
IP A.55915 > B.12345: sctp (1) [SACK] [cum ack 3799315799] [a_rwnd 86] [#gap acks 0] [#dup tsns 0]
IP B.12345 > A.55915: sctp (1) [DATA] (B)(E) [TSN: 3799315800] [SID: 0] [SSEQ 187] [PPID 0x18]
IP A.55915 > B.12345: sctp (1) [SACK] [cum ack 3799315800] [a_rwnd 43] [#gap acks 0] [#dup tsns 0]
--> Socket buffer is almost depleted, but there is space for one more packet,
send them over association 2, size 43B
IP B.12346 > A.55915: sctp (1) [DATA] (B)(E) [TSN: 3676403240] [SID: 0] [SSEQ 0] [PPID 0x18]
IP A.55915 > B.12346: sctp (1) [SACK] [cum ack 3676403240] [a_rwnd 0] [#gap acks 0] [#dup tsns 0]
--> Immediate drop
IP A.60995 > B.12346: sctp (1) [SACK] [cum ack 387491510] [a_rwnd 0] [#gap acks 0] [#dup tsns 0]
--> Read everything from the socket, both association recover up to maximum rwnd
they are capable of reaching, note that association 1 recovered up to 3698,
and association 2 recovered only to 43
IP A.55915 > B.12345: sctp (1) [SACK] [cum ack 3799315800] [a_rwnd 1548] [#gap acks 0] [#dup tsns 0]
IP A.55915 > B.12345: sctp (1) [SACK] [cum ack 3799315800] [a_rwnd 3053] [#gap acks 0] [#dup tsns 0]
IP B.12345 > A.55915: sctp (1) [DATA] (B)(E) [TSN: 3799315801] [SID: 0] [SSEQ 188] [PPID 0x18]
IP A.55915 > B.12345: sctp (1) [SACK] [cum ack 3799315801] [a_rwnd 3698] [#gap acks 0] [#dup tsns 0]
IP B.12346 > A.55915: sctp (1) [DATA] (B)(E) [TSN: 3676403241] [SID: 0] [SSEQ 1] [PPID 0x18]
IP A.55915 > B.12346: sctp (1) [SACK] [cum ack 3676403241] [a_rwnd 43] [#gap acks 0] [#dup tsns 0]
A careful reader might wonder why it is necessary to reproduce 1) prior
reproduction of 2). It is simply easier to observe when to send packet over
association 2 which will push association into the pressure state.
Proposed solution:
Both problems share the same root cause, and that is improper scaling of socket
buffer with rwnd. Solution in which sizeof(sk_buff) is taken into concern while
calculating rwnd is not possible due to fact that there is no linear
relationship between amount of data blamed in increase/decrease with IP packet
in which payload arrived. Even in case such solution would be followed,
complexity of the code would increase. Due to nature of current rwnd handling,
slow increase (in sctp_assoc_rwnd_increase) of rwnd after pressure state is
entered is rationale, but it gives false representation to the sender of current
buffer space. Furthermore, it implements additional congestion control mechanism
which is defined on implementation, and not on standard basis.
Proposed solution simplifies whole algorithm having on mind definition from rfc:
o Receiver Window (rwnd): This gives the sender an indication of the space
available in the receiver's inbound buffer.
Core of the proposed solution is given with these lines:
sctp_assoc_rwnd_update:
if ((asoc->base.sk->sk_rcvbuf - rx_count) > 0)
asoc->rwnd = (asoc->base.sk->sk_rcvbuf - rx_count) >> 1;
else
asoc->rwnd = 0;
We advertise to sender (half of) actual space we have. Half is in the braces
depending whether you would like to observe size of socket buffer as SO_RECVBUF
or twice the amount, i.e. size is the one visible from userspace, that is,
from kernelspace.
In this way sender is given with good approximation of our buffer space,
regardless of the buffer policy - we always advertise what we have. Proposed
solution fixes described problems and removes necessity for rwnd restoration
algorithm. Finally, as proposed solution is simplification, some lines of code,
along with some bytes in struct sctp_association are saved.
Version 2 of the patch addressed comments from Vlad. Name of the function is set
to be more descriptive, and two parts of code are changed, in one removing the
superfluous call to sctp_assoc_rwnd_update since call would not result in update
of rwnd, and the other being reordering of the code in a way that call to
sctp_assoc_rwnd_update updates rwnd. Version 3 corrected change introduced in v2
in a way that existing function is not reordered/copied in line, but it is
correctly called. Thanks Vlad for suggesting.
Signed-off-by: Matija Glavinic Pecotic <matija.glavinic-pecotic.ext@nsn.com>
Reviewed-by: Alexander Sverdlin <alexander.sverdlin@nsn.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
since commit 251da413("ipv4: Cache ip_error() routes even when not forwarding."),
the counter IPSTATS_MIB_INADDRERRORS can't work correctly, because the value of
err was always set to ENETUNREACH.
Signed-off-by: Duan Jiong <duanj.fnst@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Without this patch, the "cat /sys/class/net/ethN/operstate" shows
"unknown", and "ethtool ethN" shows "Link detected: yes", when VM
boots up with or without vNIC connected.
This patch fixed the problem.
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: K. Y. Srinivasan <kys@microsoft.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
dccp tfrc: revert
This reverts 6aee49c558 ("dccp: make local variable static") since
the variable tfrc_debug is referenced by the tfrc_pr_debug(fmt, ...)
macro when TFRC debugging is enabled. If it is enabled, use of the
macro produces a compilation error.
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/net/bonding/bond_options.c includes rwlock.h directly,
which is a nono, and which also breaks RT kernel build.
Signed-off-by: Mike Galbraith <bitbucket@online.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 8fdade4 ("net: of_mdio: parse "max-speed" property to set PHY
supported features") introduced a typo in of_set_phy_supported for the
first assignment of phydev->supported which will not effectively limit
the PHY device supported features bits if the PHY driver contains
"higher" features (e.g: max-speed = <100> and PHY driver has
PHY_GBIT_FEATURES set).
Fix this by making sure that the very first thing is to reset to sane
defaults (PHY_BASIC_FEATURES) and then progressively add speed features
as we parse them.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The struct driver_info ax88178_info is assigned the function
asix_rx_fixup_common as it's rx_fixup callback. This means that
FLAG_MULTI_PACKET must be set as this function is cloning the
data and calling usbnet_skb_return. Not setting this flag leads
to usbnet_skb_return beeing called a second time from within
the rx_process function in the usbnet module.
Signed-off-by: Emil Goode <emilgoode@gmail.com>
Reported-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
Even if the 'time_before' macro expand with parentheses, the look is bad.
Signed-off-by: Francois-Xavier Le Bail <fx.lebail@yahoo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
phy_init_hw not does a full PHY reset after the driver probe has
finished, so any hw initialization done in the probe will be lost.
Part of the timestamping functionality of the dp83640 is set up in the
probe and with that lost, enabling timestamping will cause a PHY
lockup, requiring a hard reset / power cycle to recover.
This patch moves all the HW initialization in dp83640_probe to
dp83640_config_init.
Signed-off-by: Stefan Sørensen <stefan.sorensen@spectralink.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 0cd8f9cc06 ("drivers: net: cpsw:
enable promiscuous mode support")
Enable promiscuous mode support for CPSW.
Introduced a crash on an am335x based board (similiar to am335x-evm).
Reason is buggy end condition in for loop in cpsw_set_promiscious()
for (i = 0; i <= priv->data.slaves; i++)
should be
for (i = 0; i < priv->data.slaves; i++)
Fix this ...
Signed-off-by: Heiko Schocher <hs@denx.de>
Cc: Mugunthan V N <mugunthanvnm@ti.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Daniel Mack <zonque@gmail.com>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Markus Pargmann <mpa@pengutronix.de>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Acked-by: Mugunthan V N <mugunthanvnm@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
vhost_zerocopy_callback accesses VQ right after it drops a ubuf
reference. In theory, this could race with device removal which waits
on the ubuf kref, and crash on use after free.
Do all accesses within rcu read side critical section, and synchronize
on release.
Since callbacks are always invoked from bh, synchronize_rcu_bh seems
enough and will help release complete a bit faster.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
vhost checked the counter within the refcnt before decrementing. It
really wanted to know that it is the one that has the last reference, as
a way to batch freeing resources a bit more efficiently.
Note: we only let refcount go to 0 on device release.
This works well but we now access the ref counter twice so there's a
race: all users might see a high count and decide to defer freeing
resources.
In the end no one initiates freeing resources until the last reference
is gone (which is on VM shotdown so might happen after a looooong time).
Let's do what we probably should have done straight away:
switch from kref to plain atomic, documenting the
semantics, return the refcount value atomically after decrement,
then use that to avoid the deadlock.
Reported-by: Qin Chuanyu <qinchuanyu@huawei.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use %zu for size_t in order to avoid the following build
warning in printks.
drivers/net/usb/sr9800.c: In function 'sr9800_bind'
drivers/net/usb/sr9800.c:826:2: warning: format '%ld' expects argument of type 'long int' but argument 5 has type 'size_t'
[-Wformat]
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix incorrect comment reported by Norbert Kiesel. Edit another comment to add
more details. Also add references to algorithm (IETF draft and paper) to top of
file.
Signed-off-by: Vijay Subramanian <subramanian.vijay@gmail.com>
CC: Mythili Prabhu <mysuryan@cisco.com>
CC: Norbert Kiesel <nkiesel@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
It's wrong if the device tree doesn't provide a phy-mode property for
the cpsw slaves as it is documented to be required in
Documentation/devicetree/bindings/net/cpsw.txt.
Anyhow it's nice to catch that problem, still more as it used to work
without this property up to commit 388367a5a9 (drivers: net: cpsw: use
cpsw-phy-sel driver to configure phy mode) which is in v3.13-rc1.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Mugunthan V N <mugunthanvnm@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When the PXS8 and PHS8 devices show up with PID 0x0053 they will expose both a
QMI port and a WWAN interface.
CC: Hans-Christoph Schemmel <hans-christoph.schemmel@gemalto.com>
CC: Christian Schmiedl <christian.schmiedl@gemalto.com>
CC: Nicolaus Colberg <nicolaus.colberg@gemalto.com>
CC: David McCullough <david.mccullough@accelecon.com>
Signed-off-by: Aleksander Morgado <aleksander@aleksander.es>
Acked-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Merge tag 'linux-can-fixes-for-3.14-20140212' of git://gitorious.org/linux-can/linux-can
linux-can-fixes-for-3.14-20140212
Marc Kleine-Budde says:
====================
this is a pull request with one patch for net/master, for the current release
cycle. Olivier Sobrie noticed and fixed that the kvaser_usb driver doesn't
check the number of channels value from the hardware, which may result in
writing over the bounds of an array in the driver.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Warning log:
xilinx_axienet_main.c: In function 'axienet_start_xmit_done':
xilinx_axienet_main.c:617:16: warning: operation on 'lp->tx_bd_ci' may be undefined [-Wsequence-point]
xilinx_axienet_main.c: In function 'axienet_start_xmit':
xilinx_axienet_main.c:703:18: warning: operation on 'lp->tx_bd_tail' may be undefined [-Wsequence-point]
xilinx_axienet_main.c:719:17: warning: operation on 'lp->tx_bd_tail' may be undefined [-Wsequence-point]
xilinx_axienet_main.c: In function 'axienet_recv':
xilinx_axienet_main.c:792:16: warning: operation on 'lp->rx_bd_ci' may be undefined [-Wsequence-point]
xilinx_axienet_main.c: In function 'axienet_of_probe':
xilinx_axienet_main.c:1501:21: warning: unused variable 'rc' [-Wunused-variable]
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
It is needed to check the number of channels returned by the HW because it
cannot be greater than MAX_NET_DEVICES otherwise it will crash.
Signed-off-by: Olivier Sobrie <olivier@sobrie.be>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Pull s390 bugfixes from Martin Schwidefsky:
"A collection a bug fixes. Most of them are minor but two of them are
more severe. The linkage stack bug can be used by user space to force
an oops, with panic_on_oops this is a denial-of-service. And the dump
memory detection issue can cause incomplete memory dumps"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/cio: improve cio_commit_config
s390: fix kernel crash due to linkage stack instructions
s390/dump: Fix dump memory detection
s390/appldata: restore missing init_virt_timer()
s390/qdio: correct program-controlled interruption checking
s390/qdio: for_each macro correctness
Pull networking updates from David Miller:
1) Fix flexcan build on big endian, from Arnd Bergmann
2) Correctly attach cpsw to GPIO bitbang MDIO drive, from Stefan Roese
3) udp_add_offload has to use GFP_ATOMIC since it can be invoked from
non-sleepable contexts. From Or Gerlitz
4) vxlan_gro_receive() does not iterate over all possible flows
properly, fix also from Or Gerlitz
5) CAN core doesn't use a proper SKB destructor when it hooks up
sockets to SKBs. Fix from Oliver Hartkopp
6) ip_tunnel_xmit() can use an uninitialized route pointer, fix from
Eric Dumazet
7) Fix address family assignment in IPVS, from Michal Kubecek
8) Fix ath9k build on ARM, from Sujith Manoharan
9) Make sure fail_over_mac only applies for the correct bonding modes,
from Ding Tianhong
10) The udp offload code doesn't use RCU correctly, from Shlomo Pongratz
11) Handle gigabit features properly in generic PHY code, from Florian
Fainelli
12) Don't blindly invoke link operations in
rtnl_link_get_slave_info_data_size, they are optional. Fix from
Fernando Luis Vazquez Cao
13) Add USB IDs for Netgear Aircard 340U, from Bjørn Mork
14) Handle netlink packet padding properly in openvswitch, from Thomas
Graf
15) Fix oops when deleting chains in nf_tables, from Patrick McHardy
16) Fix RX stalls in xen-netback driver, from Zoltan Kiss
17) Fix deadlock in mac80211 stack, from Emmanuel Grumbach
18) inet_nlmsg_size() forgets to consider ifa_cacheinfo, fix from Geert
Uytterhoeven
19) tg3_change_mtu() can deadlock, fix from Nithin Sujir
20) Fix regression in setting SCTP local source addresses on accepted
sockets, caused by some generic ipv6 socket changes. Fix from
Matija Glavinic Pecotic
21) IPPROTO_* must be pure defines, otherwise module aliases don't get
constructed properly. Fix from Jan Moskyto
22) IPV6 netconsole setup doesn't work properly unless an explicit
source address is specified, fix from Sabrina Dubroca
23) Use __GFP_NORETRY for high order skb page allocations in
sock_alloc_send_pskb and skb_page_frag_refill. From Eric Dumazet
24) Fix a regression added in netconsole over bridging, from Cong Wang
25) TCP uses an artificial offset of 1ms for SRTT, but this doesn't jive
well with TCP pacing which needs the SRTT to be accurate. Fix from
Eric Dumazet
26) Several cases of missing header file includes from Rashika Kheria
27) Add ZTE MF667 device ID to qmi_wwan driver, from Raymond Wanyoike
28) TCP Small Queues doesn't handle nonagle properly in some corner
cases, fix from Eric Dumazet
29) Remove extraneous read_unlock in bond_enslave, whoops. From Ding
Tianhong
30) Fix 9p trans_virtio handling of vmalloc buffers, from Richard Yao
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (136 commits)
6lowpan: fix lockdep splats
alx: add missing stats_lock spinlock init
9p/trans_virtio.c: Fix broken zero-copy on vmalloc() buffers
bonding: remove unwanted bond lock for enslave processing
USB2NET : SR9800 : One chip USB2.0 USB2NET SR9800 Device Driver Support
tcp: tsq: fix nonagle handling
bridge: Prevent possible race condition in br_fdb_change_mac_address
bridge: Properly check if local fdb entry can be deleted when deleting vlan
bridge: Properly check if local fdb entry can be deleted in br_fdb_delete_by_port
bridge: Properly check if local fdb entry can be deleted in br_fdb_change_mac_address
bridge: Fix the way to check if a local fdb entry can be deleted
bridge: Change local fdb entries whenever mac address of bridge device changes
bridge: Fix the way to find old local fdb entries in br_fdb_change_mac_address
bridge: Fix the way to insert new local fdb entries in br_fdb_changeaddr
bridge: Fix the way to find old local fdb entries in br_fdb_changeaddr
tcp: correct code comment stating 3 min timeout for FIN_WAIT2, we only do 1 min
net: vxge: Remove unused device pointer
net: qmi_wwan: add ZTE MF667
3c59x: Remove unused pointer in vortex_eisa_cleanup()
net: fix 'ip rule' iif/oif device rename
...
When a device ndo_start_xmit() calls again dev_queue_xmit(),
lockdep can complain because dev_queue_xmit() is re-entered and the
spinlocks protecting tx queues share a common lockdep class.
Same issue was fixed for bonding/l2tp/ppp in commits
0daa230302 ("[PATCH] bonding: lockdep annotation")
49ee49202b ("bonding: set qdisc_tx_busylock to avoid LOCKDEP splat")
23d3b8bfb8 ("net: qdisc busylock needs lockdep annotations ")
303c07db48 ("ppp: set qdisc_tx_busylock to avoid LOCKDEP splat ")
Reported-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Tested-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Trivial fix for init time stack trace occuring in
alx_get_stats64 upon start up. Should have been part of
commit adding the spinlock:
f1b6b106 alx: add alx_get_stats64 operation
Signed-off-by: John Greene <jogreene@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The 9p-virtio transport does zero copy on things larger than 1024 bytes
in size. It accomplishes this by returning the physical addresses of
pages to the virtio-pci device. At present, the translation is usually a
bit shift.
That approach produces an invalid page address when we read/write to
vmalloc buffers, such as those used for Linux kernel modules. Any
attempt to load a Linux kernel module from 9p-virtio produces the
following stack.
[<ffffffff814878ce>] p9_virtio_zc_request+0x45e/0x510
[<ffffffff814814ed>] p9_client_zc_rpc.constprop.16+0xfd/0x4f0
[<ffffffff814839dd>] p9_client_read+0x15d/0x240
[<ffffffff811c8440>] v9fs_fid_readn+0x50/0xa0
[<ffffffff811c84a0>] v9fs_file_readn+0x10/0x20
[<ffffffff811c84e7>] v9fs_file_read+0x37/0x70
[<ffffffff8114e3fb>] vfs_read+0x9b/0x160
[<ffffffff81153571>] kernel_read+0x41/0x60
[<ffffffff810c83ab>] copy_module_from_fd.isra.34+0xfb/0x180
Subsequently, QEMU will die printing:
qemu-system-x86_64: virtio: trying to map MMIO memory
This patch enables 9p-virtio to correctly handle this case. This not
only enables us to load Linux kernel modules off virtfs, but also
enables ZFS file-based vdevs on virtfs to be used without killing QEMU.
Special thanks to both Avi Kivity and Alexander Graf for their
interpretation of QEMU backtraces. Without their guidence, tracking down
this bug would have taken much longer. Also, special thanks to Linus
Torvalds for his insightful explanation of why this should use
is_vmalloc_addr() instead of is_vmalloc_or_module_addr():
https://lkml.org/lkml/2014/2/8/272
Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The bond enslave processing don't hold bond->lock anymore,
so release an unlocked rw lock will cause warning message,
remove the unwanted read_unlock(&bond->lock).
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>
Acked-by: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Merge misc fixes from Andrew Morton:
"A bunch of fixes"
* emailed patches fron Andrew Morton <akpm@linux-foundation.org>:
ocfs2: check existence of old dentry in ocfs2_link()
ocfs2: update inode size after zeroing the hole
ocfs2: fix issue that ocfs2_setattr() does not deal with new_i_size==i_size
mm/memory-failure.c: move refcount only in !MF_COUNT_INCREASED
smp.h: fix x86+cpu.c sparse warnings about arch nonboot CPU calls
mm: fix page leak at nfs_symlink()
slub: do not assert not having lock in removing freed partial
gitignore: add all.config
ocfs2: fix ocfs2_sync_file() if filesystem is readonly
drivers/edac/edac_mc_sysfs.c: poll timeout cannot be zero
fs/file.c:fdtable: avoid triggering OOMs from alloc_fdmem
xen: properly account for _PAGE_NUMA during xen pte translations
mm/slub.c: list_lock may not be held in some circumstances
drivers/md/bcache/extents.c: use %zi to format size_t
vmcore: prevent PT_NOTE p_memsz overflow during header update
drivers/message/i2o/i2o_config.c: fix deadlock in compat_ioctl(I2OGETIOPS)
Documentation/: update 00-INDEX files
checkpatch: fix detection of git repository
get_maintainer: fix detection of git repository
drivers/misc/sgi-gru/grukdump.c: unlocking should be conditional in gru_dump_context()
System call linkat first calls user_path_at(), check the existence of
old dentry, and then calls vfs_link()->ocfs2_link() to do the actual
work. There may exist a race when Node A create a hard link for file
while node B rm it.
Node A Node B
user_path_at()
->ocfs2_lookup(),
find old dentry exist
rm file, add inode say inodeA
to orphan_dir
call ocfs2_link(),create a
hard link for inodeA.
rm the link, add inodeA to orphan_dir
again
When orphan_scan work start, it calls ocfs2_queue_orphans() to do the
main work. It first tranverses entrys in orphan_dir, linking all inodes
in this orphan_dir to a list look like this:
inodeA->inodeB->...->inodeA
When tranvering this list, it will fall into loop, calling iput() again
and again. And finally trigger BUG_ON(inode->i_state & I_CLEAR).
Signed-off-by: joyce <xuejiufei@huawei.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs-writeback will release the dirty pages without page lock whose offset
are over inode size, the release happens at
block_write_full_page_endio(). If not update, dirty pages in file holes
may be released before flushed to the disk, then file holes will contain
some non-zero data, this will cause sparse file md5sum error.
To reproduce the bug, find a big sparse file with many holes, like vm
image file, its actual size should be bigger than available mem size to
make writeback work more frequently, tar it with -S option, then keep
untar it and check its md5sum again and again until you get a wrong
md5sum.
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Younger Liu <younger.liu@huawei.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The issue scenario is as following:
- Create a small file and fallocate a large disk space for a file with
FALLOC_FL_KEEP_SIZE option.
- ftruncate the file back to the original size again. but the disk free
space is not changed back. This is a real bug that be fixed in this
patch.
In order to solve the issue above, we modified ocfs2_setattr(), if
attr->ia_size != i_size_read(inode), It calls ocfs2_truncate_file(), and
truncate disk space to attr->ia_size.
Signed-off-by: Younger Liu <younger.liu@huawei.com>
Reviewed-by: Jie Liu <jeff.liu@oracle.com>
Tested-by: Jie Liu <jeff.liu@oracle.com>
Cc: Joel Becker <jlbec@evilplan.org>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Sunil Mushran <sunil.mushran@gmail.com>
Reviewed-by: Jensen <shencanquan@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mce-test detected a test failure when injecting error to a thp tail
page. This is because we take page refcount of the tail page in
madvise_hwpoison() while the fix in commit a3e0f9e47d
("mm/memory-failure.c: transfer page count from head page to tail page
after split thp") assumes that we always take refcount on the head page.
When a real memory error happens we take refcount on the head page where
memory_failure() is called without MF_COUNT_INCREASED set, so it seems
to me that testing memory error on thp tail page using madvise makes
little sense.
This patch cancels moving refcount in !MF_COUNT_INCREASED for valid
testing.
[akpm@linux-foundation.org: s/&&/&/]
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Chen Gong <gong.chen@linux.intel.com>
Cc: <stable@vger.kernel.org> [3.9+: a3e0f9e47d]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>