Commit Graph

287 Commits

Author SHA1 Message Date
David S. Miller e548833df8 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	net/mac80211/main.c
2010-09-09 22:27:33 -07:00
Jarek Poplawski 64289c8e68 gro: Re-fix different skb headrooms
The patch: "gro: fix different skb headrooms" in its part:
"2) allocate a minimal skb for head of frag_list" is buggy. The copied
skb has p->data set at the ip header at the moment, and skb_gro_offset
is the length of ip + tcp headers. So, after the change the length of
mac header is skipped. Later skb_set_mac_header() sets it into the
NET_SKB_PAD area (if it's long enough) and ip header is misaligned at
NET_SKB_PAD + NET_IP_ALIGN offset. There is no reason to assume the
original skb was wrongly allocated, so let's copy it as it was.

bugzilla : https://bugzilla.kernel.org/show_bug.cgi?id=16626
fixes commit: 3d3be4333f

Reported-by: Plamen Petrov <pvp-lsts@fs.uni-ruse.bg>
Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
CC: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Tested-by: Plamen Petrov <pvp-lsts@fs.uni-ruse.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-08 10:32:15 -07:00
Koki Sanagi 07dc22e729 skb: Add tracepoints to freeing skb
This patch adds tracepoint to consume_skb and add trace_kfree_skb
before __kfree_skb in skb_free_datagram_locked and net_tx_action.
Combinating with tracepoint on dev_hard_start_xmit, we can check
how long it takes to free transmitted packets. And using it, we can
calculate how many packets driver had at that time. It is useful when
a drop of transmitted packet is a problem.

            sshd-6828  [000] 112689.258154: consume_skb: skbaddr=f2d99bb8

Signed-off-by: Koki Sanagi <sanagi.koki@jp.fujitsu.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Kaneshige Kenji <kaneshige.kenji@jp.fujitsu.com>
Cc: Izumo Taku <izumi.taku@jp.fujitsu.com>
Cc: Kosaki Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Scott Mcmillan <scott.a.mcmillan@intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
LKML-Reference: <4C724364.50903@jp.fujitsu.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2010-09-07 17:51:53 +02:00
Eric Dumazet 1fd63041c4 net: pskb_expand_head() optimization
pskb_expand_head() blindly takes references on fragments before calling
skb_release_data(), potentially releasing these references.

We can add a fast path, avoiding these atomic operations, if we own the
last reference on skb->head.

Based on a previous patch from David

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-06 18:24:59 -07:00
Eric Dumazet 52ee7a04a0 net: remove two kmemcheck annotations
__alloc_skb() uses a memset() to clear all the beginning of skb,
including bitfields contained in 'flags1' & 'flags2'.

We dont need any more to use kmemcheck_annotate_bitfield() on these
fields. However, we still need it for the clone part, which is not
cleared.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-03 09:44:51 -07:00
Eric Dumazet 3d3be4333f gro: fix different skb headrooms
Packets entering GRO might have different headrooms, even for a given
flow (because of implementation details in drivers, like copybreak).
We cant force drivers to deliver packets with a fixed headroom.

1) fix skb_segment()

skb_segment() makes the false assumption headrooms of fragments are same
than the head. When CHECKSUM_PARTIAL is used, this can give csum_start
errors, and crash later in skb_copy_and_csum_dev()

2) allocate a minimal skb for head of frag_list

skb_gro_receive() uses netdev_alloc_skb(headroom + skb_gro_offset(p)) to
allocate a fresh skb. This adds NET_SKB_PAD to a padding already
provided by netdevice, depending on various things, like copybreak.

Use alloc_skb() to allocate an exact padding, to reduce cache line
needs:
NET_SKB_PAD + NET_IP_ALIGN

bugzilla : https://bugzilla.kernel.org/show_bug.cgi?id=16626

Many thanks to Plamen Petrov, testing many debugging patches !
With help of Jarek Poplawski.

Reported-by: Plamen Petrov <pvp-lsts@fs.uni-ruse.bg>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-01 19:17:35 -07:00
Eric Dumazet 6602cebb5b net: skbuff.c cleanup
(skb->data - skb->head) can be changed by skb_headroom(skb)

Remove some uses of NET_SKBUFF_DATA_USES_OFFSET, using
(skb_end_pointer(skb) - skb->head) or
(skb_tail_pointer(skb) - skb->head) : compiler does the right thing,
and this is more readable for us ;)

(struct skb_shared_info *) casts in pskb_expand_head() to help memcpy()
to use aligned moves.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-01 10:57:55 -07:00
David S. Miller 21dc330157 net: Rename skb_has_frags to skb_has_frag_list
SKBs can be "fragmented" in two ways, via a page array (called
skb_shinfo(skb)->frags[]) and via a list of SKBs (called
skb_shinfo(skb)->frag_list).

Since skb_has_frags() tests the latter, it's name is confusing
since it sounds more like it's testing the former.

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-23 00:13:46 -07:00
Oliver Hartkopp 2244d07bfa net: simplify flags for tx timestamping
This patch removes the abstraction introduced by the union skb_shared_tx in
the shared skb data.

The access of the different union elements at several places led to some
confusion about accessing the shared tx_flags e.g. in skb_orphan_try().

    http://marc.info/?l=linux-netdev&m=128084897415886&w=2

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-19 00:08:30 -07:00
David S. Miller bb7e95c8fd Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	drivers/net/bnx2x_main.c

Merge bnx2x bug fixes in by hand... :-/

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-07-27 21:01:35 -07:00
Eric Dumazet fed66381d6 net: pskb_expand_head() optimization
Move frags[] at the end of struct skb_shared_info, and make
pskb_expand_head() copy only the used part of it instead of whole array.

This should avoid kmemcheck warnings and speedup pskb_expand_head() as
well, avoiding a lot of cache misses.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-07-24 21:05:57 -07:00
David S. Miller be2b6e6235 net: Fix skb_copy_expand() handling of ->csum_start
It should only be adjusted if ip_summed == CHECKSUM_PARTIAL.

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-07-22 13:27:09 -07:00
Andrea Shepard 00c5a9834b net: Fix corruption of skb csum field in pskb_expand_head() of net/core/skbuff.c
Make pskb_expand_head() check ip_summed to make sure csum_start is really
csum_start and not csum before adjusting it.

This fixes a bug I encountered using a Sun Quad-Fast Ethernet card and VLANs.
On my configuration, the sunhme driver produces skbs with differing amounts
of headroom on receive depending on the packet size.  See line 2030 of
drivers/net/sunhme.c; packets smaller than RX_COPY_THRESHOLD have 52 bytes
of headroom but packets larger than that cutoff have only 20 bytes.

When these packets reach the VLAN driver, vlan_check_reorder_header()
calls skb_cow(), which, if the packet has less than NET_SKB_PAD (== 32) bytes
of headroom, uses pskb_expand_head() to make more.

Then, pskb_expand_head() needs to adjust a lot of offsets into the skb,
including csum_start.  Since csum_start is a union with csum, if the packet
has a valid csum value this will corrupt it, which was the effect I observed.
The sunhme hardware computes receive checksums, so the skbs would be created
by the driver with ip_summed == CHECKSUM_COMPLETE and a valid csum field, and
then pskb_expand_head() would corrupt the csum field, leading to an "hw csum
error" message later on, for example in icmp_rcv() for pings larger than the
sunhme RX_COPY_THRESHOLD.

On the basis of the comment at the beginning of include/linux/skbuff.h,
I believe that the csum_start skb field is only meaningful if ip_csummed is
CSUM_PARTIAL, so this patch makes pskb_expand_head() adjust it only in that
case to avoid corrupting a valid csum value.

Please see my more in-depth disucssion of tracking down this bug for
more details if you like:

http://puellavulnerata.livejournal.com/112186.html
http://puellavulnerata.livejournal.com/112567.html
http://puellavulnerata.livejournal.com/112891.html
http://puellavulnerata.livejournal.com/113096.html
http://puellavulnerata.livejournal.com/113591.html

I am not subscribed to this list, so please CC me on replies.

Signed-off-by: Andrea Shepard <andrea@persephoneslair.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-07-22 13:25:18 -07:00
Eric Dumazet 9e34a5b516 net/core: EXPORT_SYMBOL cleanups
CodingStyle cleanups

EXPORT_SYMBOL should immediately follow the symbol declaration.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-07-12 12:57:55 -07:00
Eric Dumazet e8d15e6460 net: rxhash already set in __copy_skb_header
No need to copy rxhash again in __skb_clone()

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-13 17:16:54 -07:00
John Fastabend e897082fe7 net: fix deliver_no_wcard regression on loopback device
deliver_no_wcard is not being set in skb_copy_header.
In the skb_cloned case it is not being cleared and
may cause the skb to be dropped when the loopback device
pushes it back up the stack.

Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Tested-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-13 17:12:40 -07:00
Eric Dumazet b1faf56664 net: sock_queue_err_skb() dont mess with sk_forward_alloc
Correct sk_forward_alloc handling for error_queue would need to use a
backlog of frames that softirq handler could not deliver because socket
is owned by user thread. Or extend backlog processing to be able to
process normal and error packets.

Another possibility is to not use mem charge for error queue, this is
what I implemented in this patch.

Note: this reverts commit 29030374
(net: fix sk_forward_alloc corruptions), since we dont need to lock
socket anymore.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-31 23:44:05 -07:00
David S. Miller 64960848ab Merge branch 'master' of /home/davem/src/GIT/linux-2.6/ 2010-05-31 05:46:45 -07:00
Eric Dumazet 2903037400 net: fix sk_forward_alloc corruptions
As David found out, sock_queue_err_skb() should be called with socket
lock hold, or we risk sk_forward_alloc corruption, since we use non
atomic operations to update this field.

This patch adds bh_lock_sock()/bh_unlock_sock() pair to three spots.
(BH already disabled)

1) skb_tstamp_tx() 
2) Before calling ip_icmp_error(), in __udp4_lib_err() 
3) Before calling ipv6_icmp_error(), in __udp6_lib_err()

Reported-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-29 00:20:48 -07:00
Changli Gao 5b0daa3474 skb: make skb_recycle_check() return a bool value
Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-29 00:12:13 -07:00
Linus Torvalds b1cdc4670b Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (63 commits)
  drivers/net/usb/asix.c: Fix pointer cast.
  be2net: Bug fix to avoid disabling bottom half during firmware upgrade.
  proc_dointvec: write a single value
  hso: add support for new products
  Phonet: fix potential use-after-free in pep_sock_close()
  ath9k: remove VEOL support for ad-hoc
  ath9k: change beacon allocation to prefer the first beacon slot
  sock.h: fix kernel-doc warning
  cls_cgroup: Fix build error when built-in
  macvlan: do proper cleanup in macvlan_common_newlink() V2
  be2net: Bug fix in init code in probe
  net/dccp: expansion of error code size
  ath9k: Fix rx of mcast/bcast frames in PS mode with auto sleep
  wireless: fix sta_info.h kernel-doc warnings
  wireless: fix mac80211.h kernel-doc warnings
  iwlwifi: testing the wrong variable in iwl_add_bssid_station()
  ath9k_htc: rare leak in ath9k_hif_usb_alloc_tx_urbs()
  ath9k_htc: dereferencing before check in hif_usb_tx_cb()
  rt2x00: Fix rt2800usb TX descriptor writing.
  rt2x00: Fix failed SLEEP->AWAKE and AWAKE->SLEEP transitions.
  ...
2010-05-25 16:59:51 -07:00
Jens Axboe ee9a3607fb Merge branch 'master' into for-2.6.35
Conflicts:
	fs/ext3/fsync.c

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-21 21:27:26 +02:00
Jens Axboe 35f3d14dbb pipe: add support for shrinking and growing pipes
This patch adds F_GETPIPE_SZ and F_SETPIPE_SZ fcntl() actions for
growing and shrinking the size of a pipe and adjusts pipe.c and splice.c
(and relay and network splice) usage to work with these larger (or smaller)
pipes.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-21 21:12:40 +02:00
Herbert Xu 622e0ca1cd gro: Fix bogus gso_size on the first fraglist entry
When GRO produces fraglist entries, and the resulting skb hits
an interface that is incapable of TSO but capable of FRAGLIST,
we end up producing a bogus packet with gso_size non-zero.

This was reported in the field with older versions of KVM that
did not set the TSO bits on tuntap.

This patch fixes that.

Reported-by: Igor Zhang <yugzhang@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-20 23:07:56 -07:00
Eric Dumazet 7fee226ad2 net: add a noref bit on skb dst
Use low order bit of skb->_skb_dst to tell dst is not refcounted.

Change _skb_dst to _skb_refdst to make sure all uses are catched.

skb_dst() returns the dst, regardless of noref bit set or not, but
with a lockdep check to make sure a noref dst is not given if current
user is not rcu protected.

New skb_dst_set_noref() helper to set an notrefcounted dst on a skb.
(with lockdep check)

skb_dst_drop() drops a reference only if skb dst was refcounted.

skb_dst_force() helper is used to force a refcount on dst, when skb
is queued and not anymore RCU protected.

Use skb_dst_force() in __sk_add_backlog(), __dev_xmit_skb() if
!IFF_XMIT_DST_RELEASE or skb enqueued on qdisc queue, in
sock_queue_rcv_skb(), in __nf_queue().

Use skb_dst_force() in dev_requeue_skb().

Note: dst_use_noref() still dirties dst, we might transform it
later to do one dirtying per jiffies.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-17 17:18:50 -07:00
Eric Dumazet ec7d2f2cf3 net: __alloc_skb() speedup
With following patch I can reach maximum rate of my pktgen+udpsink
simulator :
- 'old' machine : dual quad core E5450  @3.00GHz
- 64 UDP rx flows (only differ by destination port)
- RPS enabled, NIC interrupts serviced on cpu0
- rps dispatched on 7 other cores. (~130.000 IPI per second)
- SLAB allocator (faster than SLUB in this workload)
- tg3 NIC
- 1.080.000 pps without a single drop at NIC level.

Idea is to add two prefetchw() calls in __alloc_skb(), one to prefetch
first sk_buff cache line, the second to prefetch the shinfo part.

Also using one memset() to initialize all skb_shared_info fields instead
of one by one to reduce number of instructions, using long word moves.

All skb_shared_info fields before 'dataref' are cleared in 
__alloc_skb().

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-05 01:07:37 -07:00
David S. Miller 47d29646a2 net: Inline skb_pull() in eth_type_trans().
In commit 6be8ac2f ("[NET]: uninline skb_pull, de-bloats a lot")
we uninlined skb_pull.

But in some critical paths it makes sense to inline this thing
and it helps performance significantly.

Create an skb_pull_inline() so that we can do this in a way that
serves also as annotation.

Based upon a patch by Eric Dumazet.

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-02 02:21:44 -07:00
Rami Rosen ccb7c7732e net: Remove two unnecessary exports (skbuff).
There is no need to export skb_under_panic() and skb_over_panic() in
skbuff.c, since these methods are used only in skbuff.c ; this patch
removes these two exports. It also marks these functions as 'static'
and removeS the extern declarations of them from
include/linux/skbuff.h

Signed-off-by: Rami Rosen <ramirose@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-20 22:39:53 -07:00
Tom Herbert 0a9627f264 rps: Receive Packet Steering
This patch implements software receive side packet steering (RPS).  RPS
distributes the load of received packet processing across multiple CPUs.

Problem statement: Protocol processing done in the NAPI context for received
packets is serialized per device queue and becomes a bottleneck under high
packet load.  This substantially limits pps that can be achieved on a single
queue NIC and provides no scaling with multiple cores.

This solution queues packets early on in the receive path on the backlog queues
of other CPUs.   This allows protocol processing (e.g. IP and TCP) to be
performed on packets in parallel.   For each device (or each receive queue in
a multi-queue device) a mask of CPUs is set to indicate the CPUs that can
process packets. A CPU is selected on a per packet basis by hashing contents
of the packet header (e.g. the TCP or UDP 4-tuple) and using the result to index
into the CPU mask.  The IPI mechanism is used to raise networking receive
softirqs between CPUs.  This effectively emulates in software what a multi-queue
NIC can provide, but is generic requiring no device support.

Many devices now provide a hash over the 4-tuple on a per packet basis
(e.g. the Toeplitz hash).  This patch allow drivers to set the HW reported hash
in an skb field, and that value in turn is used to index into the RPS maps.
Using the HW generated hash can avoid cache misses on the packet when
steering it to a remote CPU.

The CPU mask is set on a per device and per queue basis in the sysfs variable
/sys/class/net/<device>/queues/rx-<n>/rps_cpus.  This is a set of canonical
bit maps for receive queues in the device (numbered by <n>).  If a device
does not support multi-queue, a single variable is used for the device (rx-0).

Generally, we have found this technique increases pps capabilities of a single
queue device with good CPU utilization.  Optimal settings for the CPU mask
seem to depend on architectures and cache hierarcy.  Below are some results
running 500 instances of netperf TCP_RR test with 1 byte req. and resp.
Results show cumulative transaction rate and system CPU utilization.

e1000e on 8 core Intel
   Without RPS: 108K tps at 33% CPU
   With RPS:    311K tps at 64% CPU

forcedeth on 16 core AMD
   Without RPS: 156K tps at 15% CPU
   With RPS:    404K tps at 49% CPU

bnx2x on 16 core AMD
   Without RPS  567K tps at 61% CPU (4 HW RX queues)
   Without RPS  738K tps at 96% CPU (8 HW RX queues)
   With RPS:    854K tps at 76% CPU (4 HW RX queues)

Caveats:
- The benefits of this patch are dependent on architecture and cache hierarchy.
Tuning the masks to get best performance is probably necessary.
- This patch adds overhead in the path for processing a single packet.  In
a lightly loaded server this overhead may eliminate the advantages of
increased parallelism, and possibly cause some relative performance degradation.
We have found that masks that are cache aware (share same caches with
the interrupting CPU) mitigate much of this.
- The RPS masks can be changed dynamically, however whenever the mask is changed
this introduces the possibility of generating out of order packets.  It's
probably best not change the masks too frequently.

Signed-off-by: Tom Herbert <therbert@google.com>

 include/linux/netdevice.h |   32 ++++-
 include/linux/skbuff.h    |    3 +
 net/core/dev.c            |  335 +++++++++++++++++++++++++++++++++++++--------
 net/core/net-sysfs.c      |  225 ++++++++++++++++++++++++++++++-
 net/core/skbuff.c         |    2 +
 5 files changed, 538 insertions(+), 59 deletions(-)
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-03-16 21:23:18 -07:00
Alexey Dobriyan 28dfef8feb const: constify remaining pipe_buf_operations
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-16 07:20:05 -08:00
Eric Dumazet 8964be4a9a net: rename skb->iif to skb->skb_iif
To help grep games, rename iif to skb_iif

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-11-20 15:35:04 -08:00
David S. Miller 3505d1a9fd Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	drivers/net/sfc/sfe4001.c
	drivers/net/wireless/libertas/cmd.c
	drivers/staging/Kconfig
	drivers/staging/Makefile
	drivers/staging/rtl8187se/Kconfig
	drivers/staging/rtl8192e/Kconfig
2009-11-18 22:19:03 -08:00
Herbert Xu 69c0cab120 gro: Fix illegal merging of trailer trash
When we've merged skb's with page frags, and subsequently receive
a trailer skb (< MSS) that is not completely non-linear (this can
occur on Intel NICs if the packet size falls below the threshold),
GRO ends up producing an illegal GSO skb with a frag_list.

This is harmless unless the skb is then forwarded through an
interface that requires software GSO, whereupon the GSO code
will BUG.

This patch detects this case in GRO and avoids merging the
trailer skb.

Reported-by: Mark Wagner <mwagner@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-11-17 05:18:18 -08:00
Anton Vorontsov e84af6ddef skbuff: Do not allow skb recycling with disabled IRQs
NAPI drivers try to recycle SKBs in their polling routine, but we
generally don't know the context in which the polling will be called,
and the skb recycling itself may require IRQs to be enabled.

This patch adds irqs_disabled() test to the skb_recycle_check()
routine, so that we'll not let the drivers hit the skb recycling
path with IRQs disabled.

As a side effect, this patch actually disables skb recycling for some
[broken] drivers. E.g. gianfar driver grabs an irqsave spinlock during
TX ring processing, and then tries to recycle an skb, and that caused
the following badness:

nf_conntrack version 0.5.0 (1008 buckets, 4032 max)
------------[ cut here ]------------
Badness at kernel/softirq.c:143
NIP: c003e3c4 LR: c423a528 CTR: c003e344
...
NIP [c003e3c4] local_bh_enable+0x80/0xc4
LR [c423a528] destroy_conntrack+0xd4/0x13c [nf_conntrack]
Call Trace:
[c15d1b60] [c003e32c] local_bh_disable+0x1c/0x34 (unreliable)
[c15d1b70] [c423a528] destroy_conntrack+0xd4/0x13c [nf_conntrack]
[c15d1b80] [c02c6370] nf_conntrack_destroy+0x3c/0x70

Signed-off-by: David S. Miller <davem@davemloft.net>
2009-11-11 19:03:28 -08:00
Johannes Berg 72bce62775 net: remove unused skb->do_not_encrypt
mac80211 required this due to the master netdev, but now
it can put all information into skb->cb and this can go.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-07-24 15:05:31 -04:00
Linus Torvalds d2aa455037 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (55 commits)
  netxen: fix tx ring accounting
  netxen: fix detection of cut-thru firmware mode
  forcedeth: fix dma api mismatches
  atm: sk_wmem_alloc initial value is one
  net: correct off-by-one write allocations reports
  via-velocity : fix no link detection on boot
  Net / e100: Fix suspend of devices that cannot be power managed
  TI DaVinci EMAC : Fix rmmod error
  net: group address list and its count
  ipv4: Fix fib_trie rebalancing, part 2
  pkt_sched: Update drops stats in act_police
  sky2: version 1.23
  sky2: add GRO support
  sky2: skb recycling
  sky2: reduce default transmit ring
  sky2: receive counter update
  sky2: fix shutdown synchronization
  sky2: PCI irq issues
  sky2: more receive shutdown
  sky2: turn off pause during shutdown
  ...

Manually fix trivial conflict in net/core/skbuff.c due to kmemcheck
2009-06-18 14:07:15 -07:00
Stephen Hemminger 603a8bbe62 skbuff: don't corrupt mac_header on skb expansion
The skb mac_header field is sometimes NULL (or ~0u) as a sentinel
value. The places where skb is expanded add an offset which would
change this flag into an invalid pointer (or offset).

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-06-17 18:46:41 -07:00
Stephen Hemminger 19633e129c skbuff: skb_mac_header_was_set is always true on >32 bit
Looking at the crash in log_martians(), one suspect is that the check for
mac header being set is not correct.  The value of mac_header defaults to
0 on allocation, therefore skb_mac_header_was_set will always be true on
platforms using NET_SKBUFF_USES_OFFSET.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-06-17 18:46:03 -07:00
Linus Torvalds b3fec0fe35 Merge branch 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/vegard/kmemcheck
* 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/vegard/kmemcheck: (39 commits)
  signal: fix __send_signal() false positive kmemcheck warning
  fs: fix do_mount_root() false positive kmemcheck warning
  fs: introduce __getname_gfp()
  trace: annotate bitfields in struct ring_buffer_event
  net: annotate struct sock bitfield
  c2port: annotate bitfield for kmemcheck
  net: annotate inet_timewait_sock bitfields
  ieee1394/csr1212: fix false positive kmemcheck report
  ieee1394: annotate bitfield
  net: annotate bitfields in struct inet_sock
  net: use kmemcheck bitfields API for skbuff
  kmemcheck: introduce bitfield API
  kmemcheck: add opcode self-testing at boot
  x86: unify pte_hidden
  x86: make _PAGE_HIDDEN conditional
  kmemcheck: make kconfig accessible for other architectures
  kmemcheck: enable in the x86 Kconfig
  kmemcheck: add hooks for the page allocator
  kmemcheck: add hooks for page- and sg-dma-mappings
  kmemcheck: don't track page tables
  ...
2009-06-16 13:09:51 -07:00
Vegard Nossum fe55f6d5c0 net: use kmemcheck bitfields API for skbuff
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
2009-06-15 15:49:25 +02:00
David S. Miller 9cbc1cb8cd Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6
Conflicts:
	Documentation/feature-removal-schedule.txt
	drivers/scsi/fcoe/fcoe.c
	net/core/drop_monitor.c
	net/core/net-traces.c
2009-06-15 03:02:23 -07:00
Linus Torvalds 8623661180 Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (244 commits)
  Revert "x86, bts: reenable ptrace branch trace support"
  tracing: do not translate event helper macros in print format
  ftrace/documentation: fix typo in function grapher name
  tracing/events: convert block trace points to TRACE_EVENT(), fix !CONFIG_BLOCK
  tracing: add protection around module events unload
  tracing: add trace_seq_vprint interface
  tracing: fix the block trace points print size
  tracing/events: convert block trace points to TRACE_EVENT()
  ring-buffer: fix ret in rb_add_time_stamp
  ring-buffer: pass in lockdep class key for reader_lock
  tracing: add annotation to what type of stack trace is recorded
  tracing: fix multiple use of __print_flags and __print_symbolic
  tracing/events: fix output format of user stack
  tracing/events: fix output format of kernel stack
  tracing/trace_stack: fix the number of entries in the header
  ring-buffer: discard timestamps that are at the start of the buffer
  ring-buffer: try to discard unneeded timestamps
  ring-buffer: fix bug in ring_buffer_discard_commit
  ftrace: do not profile functions when disabled
  tracing: make trace pipe recognize latency format flag
  ...
2009-06-10 19:53:40 -07:00
Johannes Berg 8f77f3849c mac80211: do not pass PS frames out of mac80211 again
In order to handle powersave frames properly we had needed
to pass these out to the device queues again, and introduce
the skb->requeue bit. This, however, also has unnecessary
overhead by needing to 'clean up' already tried frames, and
this clean-up code is also buggy when software encryption
is used.

Instead of sending the frames via the master netdev queue
again, simply put them into the pending queue. This also
fixes a problem where frames for that particular station
could be reordered when some were still on the software
queues and older ones are re-injected into the software
queue after them.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-06-10 13:28:37 -04:00
David S. Miller fbb398a832 net/core/skbuff.c: Use frag list abstraction interfaces.
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-06-09 00:18:59 -07:00
Herbert Xu 5ff8dda303 net: Ensure partial checksum offset is inside the skb head
On Thu, Jun 04, 2009 at 09:06:00PM +1000, Herbert Xu wrote:
>
> tun: Optimise handling of bogus gso->hdr_len
>
> As all current versions of virtio_net generate a value for the
> header length that's too small, we should optimise this so that
> we don't copy it twice.  This can be done by ensuring that it is
> at least as large as the place where we'll write the checksum.
>
> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

With this applied we can strengthen the partial checksum check:

In skb_partial_csum_set we check to see if the checksum offset
is within the packet.  However, we really should check that it
is within the skb head as that's the only bit we can modify
without copying.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-06-08 00:20:19 -07:00
Eric Dumazet adf30907d6 net: skb->dst accessors
Define three accessors to get/set dst attached to a skb

struct dst_entry *skb_dst(const struct sk_buff *skb)

void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst)

void skb_dst_drop(struct sk_buff *skb)
This one should replace occurrences of :
dst_release(skb->dst)
skb->dst = NULL;

Delete skb->dst field

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-06-03 02:51:04 -07:00
Herbert Xu 9aaa156cf9 gro: Store shinfo in local variable in skb_gro_receive
This patch stores the two shinfo pointers in local variables
because they're used over and over again in skb_gro_receive.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-05-27 03:26:05 -07:00
Herbert Xu 66e92fcf1d gro: Nasty optimisations for page frags in skb_gro_receive
This patch reverses the direction of the frags array copy in
skb_gro_receive in order simplify the loop conditional.  It
also avoids touching the first element of the original frags
array.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-05-27 03:26:04 -07:00
Herbert Xu 67147ba99a gro: Localise offset/headlen in skb_gro_offset
This patch stores the offset/headlen in local variables as they're
used repeatedly in skb_gro_offset.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-05-27 03:25:55 -07:00
Herbert Xu 42da6994ca gro: Open-code frags copy in skb_gro_receive
gcc does a poor job at generating code for the memcpy of the frags
array in skb_gro_receive, which is the primary purpose of that
function when merging frags.  In particular, it can't utilise the
alignment information of the source and destination.  This patch
open-codes the copy so we process words instead of bytes.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-05-27 03:25:54 -07:00
David S. Miller c649c0e31d Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	drivers/net/wireless/ath/ath5k/phy.c
	drivers/net/wireless/iwlwifi/iwl-agn.c
	drivers/net/wireless/iwlwifi/iwl3945-base.c
2009-05-25 01:42:21 -07:00
Herbert Xu 9bcb97cace skbuff: Copy csum instead of csum_start/csum_offset
Hi:

skbuff: Copy csum instead of csum_start/csum_offset

It's easier to copy the u32 csum instead of its two u16
constituents.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Cheers,
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-05-25 00:40:43 -07:00
Herbert Xu 82c49a352e skbuff: Move new code into __copy_skb_header
Hi:

skbuff: Move new __skb_clone code into __copy_skb_header

It seems that people just keep on adding stuff to __skb_clone
instead __copy_skb_header.  This is wrong as it means your brand-new
attributes won't always get copied as you intended.

This patch moves them to the right place, and adds a comment to
prevent this from happening again.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Thanks,
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-05-25 00:40:43 -07:00
Thomas Chenault 995b337952 net: fix skb_seq_read returning wrong offset/length for page frag data
When called with a consumed value that is less than skb_headlen(skb)
bytes into a page frag, skb_seq_read() incorrectly returns an
offset/length relative to skb->data. Ensure that data which should come
from a page frag does.

Signed-off-by: Thomas Chenault <thomas_chenault@dell.com>
Tested-by: Shyam Iyer <shyam_iyer@dell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-05-18 21:43:27 -07:00
Ingo Molnar 1079cac0f4 Merge commit 'v2.6.30-rc6' into tracing/core
Merge reason: we were on an -rc4 base, sync up to -rc6

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-18 10:15:35 +02:00
Ingo Molnar 44347d947f Merge branch 'linus' into tracing/core
Merge reason: tracing/core was on a .30-rc1 base and was missing out on
              on a handful of tracing fixes present in .30-rc5-almost.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-07 11:17:34 +02:00
Lennert Buytenhek b805007545 net: update skb_recycle_check() for hardware timestamping changes
Commit ac45f602ee ("net: infrastructure
for hardware time stamping") added two skb initialization actions to
__alloc_skb(), which need to be added to skb_recycle_check() as well.

Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Patrick Ohly <patrick.ohly@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-05-06 16:49:18 -07:00
Jarek Poplawski 7a67e56fd3 net: Fix oops when splicing skbs from a frag_list.
Lennert Buytenhek wrote:
> Since 4fb6699481 ("net: Optimize memory
> usage when splicing from sockets.") I'm seeing this oops (e.g. in
> 2.6.30-rc3) when splicing from a TCP socket to /dev/null on a driver
> (mv643xx_eth) that uses LRO in the skb mode (lro_receive_skb) rather
> than the frag mode:

My patch incorrectly assumed skb->sk was always valid, but for
"frag_listed" skbs we can only use skb->sk of their parent.

Reported-by: Lennert Buytenhek <buytenh@wantstofly.org>
Debugged-by: Lennert Buytenhek <buytenh@wantstofly.org>
Tested-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-30 05:41:19 -07:00
Steven Rostedt ad8d75fff8 tracing/events: move trace point headers into include/trace/events
Impact: clean up

Create a sub directory in include/trace called events to keep the
trace point headers in their own separate directory. Only headers that
declare trace points should be defined in this directory.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Zhao Lei <zhaolei@cn.fujitsu.com>
Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-14 22:05:43 -04:00
Herbert Xu 2f181855a0 gso: Fix support for linear packets
When GRO/frag_list support was added to GSO, I made an error
which broke the support for segmenting linear GSO packets (GSO
packets are normally non-linear in the payload).

These days most of these packets are constructed by the tun
driver, which prefers to allocate linear memory if possible.
This is fixed in the latest kernel, but for 2.6.29 and earlier
it is still the norm.

Therefore this bug causes failures with GSO when used with tun
in 2.6.29.

Reported-by: James Huang <jamesclhuang@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-28 23:39:18 -07:00
Neil Horman ead2ceb0ec Network Drop Monitor: Adding kfree_skb_clean for non-drops and modifying end-of-line points for skbs
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>

 include/linux/skbuff.h |    4 +++-
 net/core/datagram.c    |    2 +-
 net/core/skbuff.c      |   22 ++++++++++++++++++++++
 net/ipv4/arp.c         |    2 +-
 net/ipv4/udp.c         |    2 +-
 net/packet/af_packet.c |    2 +-
 6 files changed, 29 insertions(+), 5 deletions(-)
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-13 12:09:28 -07:00
Wei Yongjun f3fbbe0f6f core: remove some pointless conditionals before kfree_skb()
Remove some pointless conditionals before kfree_skb().

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-26 23:07:36 -08:00
David S. Miller e70049b9e7 Merge branch 'master' of /home/davem/src/GIT/linux-2.6/ 2009-02-24 03:50:29 -08:00
David S. Miller 92a0acce18 net: Kill skb_truesize_check(), it only catches false-positives.
A long time ago we had bugs, primarily in TCP, where we would modify
skb->truesize (for TSO queue collapsing) in ways which would corrupt
the socket memory accounting.

skb_truesize_check() was added in order to try and catch this error
more systematically.

However this debugging check has morphed into a Frankenstein of sorts
and these days it does nothing other than catch false-positives.

Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-17 21:24:05 -08:00
Patrick Ohly ac45f602ee net: infrastructure for hardware time stamping
The additional per-packet information (16 bytes for time stamps, 1
byte for flags) is stored for all packets in the skb_shared_info
struct. This implementation detail is hidden from users of that
information via skb_* accessor functions. A separate struct resp.
union is used for the additional information so that it can be
stored/copied easily outside of skb_shared_info.

Compared to previous implementations (reusing the tstamp field
depending on the context, optional additional structures) this
is the simplest solution. It does not extend sk_buff itself.

TX time stamping is implemented in software if the device driver
doesn't support hardware time stamping.

The new semantic for hardware/software time stamping around
ndo_start_xmit() is based on two assumptions about existing
network device drivers which don't support hardware time
stamping and know nothing about it:
 - they leave the new skb_shared_tx unmodified
 - the keep the connection to the originating socket in skb->sk
   alive, i.e., don't call skb_orphan()

Given that skb_shared_tx is new, the first assumption is safe.
The second is only true for some drivers. As a result, software
TX time stamping currently works with the bnx2 driver, but not
with the unmodified igb driver (the two drivers this patch series
was tested with).

Signed-off-by: Patrick Ohly <patrick.ohly@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-15 22:43:34 -08:00
Jarek Poplawski ce3dd39595 net: Fix page seeking for skb_splice_bits().
struct page walking should be done with proper accessor functions, not
directly.

With doubts from David S. Miller and Herbert Xu.

Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-12 16:51:43 -08:00
David S. Miller b4ac530fc3 net: Move skbuff symbol exports after each symbol's definition.
net/core/skbuff.c is a hodge-podge of symbol export placement.
Some of the exports are right after the definition of the
symbol being exported, others are clumped together into a big
group at the end of the file.

Make things consistent.

Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-10 02:09:24 -08:00
Herbert Xu 56035022d8 gro: Fix frag_list merging on imprecisely split packets
The previous fix ad0f990444 (gro:
Fix handling of imprecisely split packets) only fixed the case
of frags merging, frag_list merging in the same circumstances
were still broken.

In particular, the packet headers end up in the data stream.

This patch fixes this plus another issue where an imprecisely
split packet header may be read incorrectly (this is mostly
harmless since it'll simply cause the packet to not match and
be rejected for GRO).

Thanks to Emil Tantilov and Jeff Kirsher for helping to track
this down.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-05 21:26:52 -08:00
Jarek Poplawski 4fb6699481 net: Optimize memory usage when splicing from sockets.
The recent fix of data corruption when splicing from sockets uses
memory very inefficiently allocating a new page to copy each chunk of
linear part of skb. This patch uses the same page until it's full
(almost) by caching the page in sk_sndmsg_page field.

With changes from David S. Miller <davem@davemloft.net>

Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-01 00:41:42 -08:00
David S. Miller 05bee47377 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	drivers/net/e1000/e1000_main.c
2009-01-30 14:31:07 -08:00
Herbert Xu 81705ad1b2 gro: Do not merge paged packets into frag_list
gro: Do not merge paged packets into frag_list

Bigger is not always better :)

It was easy to continue to merged packets into frag_list after the
page array is full.  However, this turns out to be worse than LRO
because frag_list is a much less efficient form of storage than the
page array.  So we're better off stopping the merge and starting
a new entry with an empty page array.

In future we can optimise this further by doing frag_list merging
but making sure that we continue to fill in the page array.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-01-29 16:33:04 -08:00
Herbert Xu 86911732d3 gro: Avoid copying headers of unmerged packets
Unfortunately simplicity isn't always the best.  The fraginfo
interface turned out to be suboptimal.  The problem was quite
obvious.  For every packet, we have to copy the headers from
the frags structure into skb->head, even though for 99% of the
packets this part is immediately thrown away after the merge.

LRO didn't have this problem because it directly read the headers
from the frags structure.

This patch attempts to address this by creating an interface
that allows GRO to access the headers in the first frag without
having to copy it.  Because all drivers that use frags place the
headers in the first frag this optimisation should be enough.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-01-29 16:33:03 -08:00
Shyam Iyer 71b3346d18 net: Fix OOPS in skb_seq_read().
It oopsd for me in skb_seq_read. addr2line said it was
linux-2.6/net/core/skbuff.c:2228, which is this line:


	while (st->frag_idx < skb_shinfo(st->cur_skb)->nr_frags) {


I added some printks in there and it looks like we hit this:

        } else if (st->root_skb == st->cur_skb &&
                   skb_shinfo(st->root_skb)->frag_list) {
                 st->cur_skb = skb_shinfo(st->root_skb)->frag_list;
                 st->frag_idx = 0;
                 goto next_skb;
        }



Actually I did some testing and added a few printks and found that the
st->cur_skb->data was 0 and hence the ptr used by iscsi_tcp was null.
This caused the kernel panic.

 	if (abs_offset < block_limit) {
-		*data = st->cur_skb->data + abs_offset;
+		*data = st->cur_skb->data + (abs_offset - st->stepped_offset);

I enabled the debug_tcp and with a few printks found that the code did
not go to the next_skb label and could find that the sequence being
followed was this -

It hit this if condition -

        if (st->cur_skb->next) {
                st->cur_skb = st->cur_skb->next;
                st->frag_idx = 0;
                goto next_skb;

And so, now the st pointer is shifted to the next skb whereas actually
it should have hit the second else if first since the data is in the
frag_list.

        else if (st->root_skb == st->cur_skb &&
                 skb_shinfo(st->root_skb)->frag_list) {
                st->cur_skb = skb_shinfo(st->root_skb)->frag_list;
                goto next_skb;
        }

Reversing the two conditions the attached patch fixes the issue for me
on top of Herbert's patches. 

Signed-off-by: Shyam Iyer <shyam_iyer@dell.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-01-29 16:12:42 -08:00
Herbert Xu 95e3b24cfb net: Fix frag_list handling in skb_seq_read
The frag_list handling was broken in skb_seq_read:

1) We didn't add the stepped offset when looking at the head
are of fragments other than the first.

2) We didn't take the stepped offset away when setting the data
pointer in the head area.

3) The frag index wasn't reset.

This patch fixes both issues.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-01-29 16:07:52 -08:00
Herbert Xu 37fe4732b9 gro: Fix merging of paged packets
The previous fix to paged packets broke the merging because it
reset the skb->len before we added it to the merged packet.  This
wasn't detected because it simply resulted in the truncation of
the packet while the missing bit is subsequently retransmitted.

The fix is to store skb->len before we clobber it.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-01-20 14:44:03 -08:00
Jarek Poplawski 8b9d372897 net: Fix data corruption when splicing from sockets.
The trick in socket splicing where we try to convert the skb->data
into a page based reference using virt_to_page() does not work so
well.

The idea is to pass the virt_to_page() reference via the pipe
buffer, and refcount the buffer using a SKB reference.

But if we are splicing from a socket to a socket (via sendpage)
this doesn't work.

The from side processing will grab the page (and SKB) references.
The sendpage() calls will grab page references only, return, and
then the from side processing completes and drops the SKB ref.

The page based reference to skb->data is not enough to keep the
kmalloc() buffer backing it from being reused.  Yet, that is
all that the socket send side has at this point.

This leads to data corruption if the skb->data buffer is reused
by SLAB before the send side socket actually gets the TX packet
out to the device.

The fix employed here is to simply allocate a page and copy the
skb->data bytes into that page.

This will hurt performance, but there is no clear way to fix this
properly without a copy at the present time, and it is important
to get rid of the data corruption.

With fixes from Herbert Xu.

Tested-by: Willy Tarreau <w@1wt.eu>
Foreseen-by: Changli Gao <xiaosuo@gmail.com>
Diagnosed-by: Willy Tarreau <w@1wt.eu>
Reported-by: Willy Tarreau <w@1wt.eu>
Fixed-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-01-19 17:03:56 -08:00
Herbert Xu f557206800 gro: Fix page ref count for skbs freed normally
When an skb with page frags is merged into an existing one, we
cannibalise its reference count.  This is OK when the skb is
reused because we set nr_frags to zero in that case.  However,
for the case where the skb is freed through kfree_skb, we didn't
clear nr_frags which causes the page to be freed prematurely.

This is fixed by moving the skb resetting into skb_gro_receive.

Reported-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-01-14 20:40:03 -08:00
Herbert Xu 5d38a079ce gro: Add page frag support
This patch allows GRO to merge page frags (skb_shinfo(skb)->frags)
in one skb, rather than using the less efficient frag_list.

It also adds a new interface, napi_gro_frags to allow drivers
to inject page frags directly into the stack without allocating
an skb.  This is intended to be the GRO equivalent for LRO's
lro_receive_frags interface.

The existing GSO interface can already handle page frags with
or without an appended frag_list so nothing needs to be changed
there.

The merging itself is rather simple.  We store any new frag entries
after the last existing entry, without checking whether the first
new entry can be merged with the last existing entry.  Making this
check would actually be easy but since no existing driver can
produce contiguous frags anyway it would just be mental masturbation.

If the total number of entries would exceed the capacity of a
single skb, we simply resort to using frag_list as we do now.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-01-04 16:13:40 -08:00
Herbert Xu b530256d2e gro: Use gso_size to store MSS
In order to allow GRO packets without frag_list at all, we need to
store the MSS in the packet itself.  The obvious place is gso_size.
The only thing to watch out for is if the packet ends up not being
GRO then we need to clear gso_size before pushing the packet into
the stack.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-01-04 16:13:19 -08:00
Herbert Xu 71d93b39e5 net: Add skb_gro_receive
This patch adds the helper skb_gro_receive to merge packets for
GRO.  The current method is to allocate a new header skb and then
chain the original packets to its frag_list.  This is done to
make it easier to integrate into the existing GSO framework.

In future as GSO is moved into the drivers, we can undo this and
simply chain the original packets together.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-15 23:42:33 -08:00
Herbert Xu 89319d3801 net: Add frag_list support to skb_segment
This patch adds limited support for handling frag_list packets in
skb_segment.  The intention is to support GRO (Generic Receive Offload)
packets which will be constructed by chaining normal packets using
frag_list.

As such we require all frag_list members terminate on exact MSS
boundaries.  This is checked using BUG_ON.

As there should only be one producer in the kernel of such packets,
namely GRO, this requirement should not be difficult to maintain.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-15 23:26:06 -08:00
David S. Miller 5b9ab2ec04 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:

	drivers/net/hp-plus.c
	drivers/net/wireless/ath5k/base.c
	drivers/net/wireless/ath9k/recv.c
	net/wireless/reg.c
2008-11-26 23:48:40 -08:00
Arjan van de Ven 8f480c0e4e net: make skb_truesize_bug() call WARN()
The truesize message check is important enough to make it print "BUG"
to the user console... lets also make it important enough to spit a
backtrace/module list etc so that kerneloops.org can track them.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-25 21:08:13 -08:00
Ilpo Järvinen 9f782db3f5 tcp: skb_shift cannot cache frag ptrs past pskb_expand_head
Since pskb_expand_head creates copy of the shared area we
cannot keep any frag ptr past de-cloning. This fixes the
tcpdump recvfrom -EFAULT problem.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-25 13:57:01 -08:00
Ilpo Järvinen 0ace285605 tcp: handle shift/merge of cloned skbs too
This caused me to get repeatably:

  tcpdump: pcap_loop: recvfrom: Bad address

Happens occassionally when I tcpdump my for-looped test xfers:
  while [ : ]; do echo -n "$(date '+%s.%N') "; ./sendfile; sleep 20; done

Rest of the relevant commands:
  ethtool -K eth0 tso off
  tc qdisc add dev eth0 root netem drop 4%
  tcpdump -n -s0 -i eth0 -w sacklog.all

Running net-next under kvm, connection goes to the same host
(basically just out of kvm). The connection itself works ok
and data gets sent without corruption even with a large
number of tests while tcpdump fails usually within less than
5 tests.

Whether it only happens because of this change or not, I
don't know for sure but it's the only thing with which
I've seen that error. The non-cloned variant works w/o it
for much longer time. I'm yet to debug where the error
actually comes from.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-24 21:30:21 -08:00
Ilpo Järvinen 832d11c5cd tcp: Try to restore large SKBs while SACK processing
During SACK processing, most of the benefits of TSO are eaten by
the SACK blocks that one-by-one fragment SKBs to MSS sized chunks.
Then we're in problems when cleanup work for them has to be done
when a large cumulative ACK comes. Try to return back to pre-split
state already while more and more SACK info gets discovered by
combining newly discovered SACK areas with the previous skb if
that's SACKed as well.

This approach has a number of benefits:

1) The processing overhead is spread more equally over the RTT
2) Write queue has less skbs to process (affect everything
   which has to walk in the queue past the sacked areas)
3) Write queue is consistent whole the time, so no other parts
   of TCP has to be aware of this (this was not the case with
   some other approach that was, well, quite intrusive all
   around).
4) Clean_rtx_queue can release most of the pages using single
   put_page instead of previous PAGE_SIZE/mss+1 calls

In case a hole is fully filled by the new SACK block, we attempt
to combine the next skb too which allows construction of skbs
that are even larger than what tso split them to and it handles
hole per on every nth patterns that often occur during slow start
overshoot pretty nicely. Though this to be really useful also
a retransmission would have to get lost since cumulative ACKs
advance one hole at a time in the most typical case.

TODO: handle upwards only merging. That should be rather easy
when segment is fully sacked but I'm leaving that as future
work item (it won't make very large difference anyway since
this current approach already covers quite a lot of normal
cases).

I was earlier thinking of some sophisticated way of tracking
timestamps of the first and the last segment but later on
realized that it won't be that necessary at all to store the
timestamp of the last segment. The cases that can occur are
basically either:
  1) ambiguous => no sensible measurement can be taken anyway
  2) non-ambiguous is due to reordering => having the timestamp
     of the last segment there is just skewing things more off
     than does some good since the ack got triggered by one of
     the holes (besides some substle issues that would make
     determining right hole/skb even harder problem). Anyway,
     it has nothing to do with this change then.

I choose to route some abnormal looking cases with goto noop,
some could be handled differently (eg., by stopping the
walking at that skb but again). In general, they either
shouldn't happen at all or are rare enough to make no difference
in practice.

In theory this change (as whole) could cause some macroscale
regression (global) because of cache misses that are taken over
the round-trip time but it gets very likely better because of much
less (local) cache misses per other write queue walkers and the
big recovery clearing cumulative ack.

Worth to note that these benefits would be very easy to get also
without TSO/GSO being on as long as the data is in pages so that
we can merge them. Currently I won't let that happen because
DSACK splitting at fragment that would mess up pcounts due to
sk_can_gso in tcp_set_skb_tso_segs. Once DSACKs fragments gets
avoided, we have some conditions that can be made less strict.

TODO: I will probably have to convert the excessive pointer
passing to struct sacktag_state... :-)

My testing revealed that considerable amount of skbs couldn't
be shifted because they were cloned (most likely still awaiting
tx reclaim)...

[The rest is considering future work instead since I got
repeatably EFAULT to tcpdump's recvfrom when I added
pskb_expand_head to deal with clones, so I separated that
into another, later patch]

...To counter that, I gave up on the fifth advantage:

5) When growing previous SACK block, less allocs for new skbs
   are done, basically a new alloc is needed only when new hole
   is detected and when the previous skb runs out of frags space

...which now only happens of if reclaim is fast enough to dispose
the clone before the SACK block comes in (the window is RTT long),
otherwise we'll have to alloc some.

With clones being handled I got these numbers (will be somewhat
worse without that), taken with fine-grained mibs:

                  TCPSackShifted 398
                   TCPSackMerged 877
            TCPSackShiftFallback 320
      TCPSACKCOLLAPSEFALLBACKGSO 0
  TCPSACKCOLLAPSEFALLBACKSKBBITS 0
  TCPSACKCOLLAPSEFALLBACKSKBDATA 0
    TCPSACKCOLLAPSEFALLBACKBELOW 0
    TCPSACKCOLLAPSEFALLBACKFIRST 1
 TCPSACKCOLLAPSEFALLBACKPREVBITS 318
      TCPSACKCOLLAPSEFALLBACKMSS 1
   TCPSACKCOLLAPSEFALLBACKNOHEAD 0
    TCPSACKCOLLAPSEFALLBACKSHIFT 0
          TCPSACKCOLLAPSENOOPSEQ 0
  TCPSACKCOLLAPSENOOPSMALLPCOUNT 0
     TCPSACKCOLLAPSENOOPSMALLLEN 0
             TCPSACKCOLLAPSEHOLE 12

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-24 21:20:15 -08:00
David S. Miller 7e452baf6b Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:

	drivers/message/fusion/mptlan.c
	drivers/net/sfc/ethtool.c
	net/mac80211/debugfs_sta.c
2008-11-11 15:43:02 -08:00
Lennert Buytenhek 5cd33db212 net: fix setting of skb->tail in skb_recycle_check()
Since skb_reset_tail_pointer() reads skb->data, we need to set
skb->data before calling skb_reset_tail_pointer().  This was causing
spurious skb_over_panic()s from skb_put() being called on a recycled
skb that had its skb->tail set to beyond where it should have been.

Bug report from Peter van Valderen <linux@ddcrew.com>.

Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-10 21:45:05 -08:00
David S. Miller 9eeda9abd1 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:

	drivers/net/wireless/ath5k/base.c
	net/8021q/vlan_core.c
2008-11-06 22:43:03 -08:00
Stephen Hemminger d1a203eac0 net: add documentation for skb recycling
Commit 04a4bb55bc ("net: add
skb_recycle_check() to enable netdriver skb recycling") added a
method for network drivers to recycle skbuffs, but while use of
this mechanism was documented in the commit message, it should
really have been added as a docbook comment as well -- this
patch does that.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-01 21:01:09 -07:00
Sujith 8b30b1fe36 mac80211: Re-enable aggregation
Wireless HW without any dedicated queues for aggregation
do not need the ampdu_queues mechanism present right now
in mac80211. Since mac80211 is still incomplete wrt TX MQ
changes, do not allow aggregation sessions for drivers that
set ampdu_queues.

This is only an interim hack until Intel fixes the requeue issue.

Signed-off-by: Sujith <Sujith.Manoharan@atheros.com>
Signed-off-by: Luis Rodriguez <Luis.Rodriguez@Atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-10-31 19:02:14 -04:00
Alexey Dobriyan def8b4faff net: reduce structures when XFRM=n
ifdef out
* struct sk_buff::sp		(pointer)
* struct dst_entry::xfrm	(pointer)
* struct sock::sk_policy	(2 pointers)

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-28 13:24:06 -07:00
Alan Cox 113aa838ec net: Rationalise email address: Network Specific Parts
Clean up the various different email addresses of mine listed in the code
to a single current and valid address. As Dave says his network merges
for 2.6.28 are now done this seems a good point to send them in where
they won't risk disrupting real changes.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-13 19:01:08 -07:00
Peter Zijlstra 654bed16cf net: packet split receive api
Add some packet-split receive hooks.

For one this allows to do NUMA node affine page allocs. Later on these
hooks will be extended to do emergency reserve allocations for
fragments.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-07 14:22:33 -07:00
Herbert Xu 4edd87ad5c net: BUG instead of corrupting memory in pskb_expand_head
If the caller of pskb_expand_head specifies a negative nhead
we'll silently overwrite other people's memory.  This patch
makes it BUG instead.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-01 07:09:38 -07:00
Lennert Buytenhek 04a4bb55bc net: add skb_recycle_check() to enable netdriver skb recycling
This patch adds skb_recycle_check(), which can be used by a network
driver after transmitting an skb to check whether this skb can be
recycled as a receive buffer.

skb_recycle_check() checks that the skb is not shared or cloned, and
that it is linear and its head portion large enough (as determined by
the driver) to be recycled as a receive buffer.  If these conditions
are met, it does any necessary reference count dropping and cleans
up the skbuff as if it just came from __alloc_skb().

Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-01 02:33:12 -07:00
Herbert Xu 6f85a124d8 net: Preserve netfilter attributes in skb_gso_segment using __copy_skb_header
skb_gso_segment didn't preserve some attributes in the original skb
such as the netfilter fields.  This was harmless until they were used
which is the case for packets going through lo.

This patch makes it call __copy_skb_header which also picks up some
other missing attributes.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-08-15 19:51:36 -07:00
Johannes Berg d0f0980414 mac80211: partially fix skb->cb use
This patch fixes mac80211 to not use the skb->cb over the queue step
from virtual interfaces to the master. The patch also, for now,
disables aggregation because that would still require requeuing,
will fix that in a separate patch. There are two other places (software
requeue and powersaving stations) where requeue can happen, but that is
not currently used by any drivers/not possible to use respectively.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-07-29 16:55:08 -04:00
Ilpo Järvinen 547b792cac net: convert BUG_TRAP to generic WARN_ON
Removes legacy reinvent-the-wheel type thing. The generic
machinery integrates much better to automated debugging aids
such as kerneloops.org (and others), and is unambiguous due to
better naming. Non-intuively BUG_TRAP() is actually equal to
WARN_ON() rather than BUG_ON() though some might actually be
promoted to BUG_ON() but I left that to future.

I could make at least one BUILD_BUG_ON conversion.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-25 21:43:18 -07:00
Harvey Harrison 7b1c65faa2 net: make __skb_splice_bits static
net/core/skbuff.c:1335:5: warning: symbol '__skb_splice_bits' was not declared. Should it be static?

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-16 20:12:30 -07:00