I've found the problem in general. It affects any 64-bit
architecture. The problem occurs when you change the system time.
Suppose that when you boot your system clock is forward by a day.
This gets recorded down in skb_tv_base. You then wind the clock back
by a day. From that point onwards the offset will be negative which
essentially overflows the 32-bit variables they're stored in.
In fact, why don't we just store the real time stamp in those 32-bit
variables? After all, we're not going to overflow for quite a while
yet.
When we do overflow, we'll need a better solution of course.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
initialized which can cause problems for drivers that expect the network
structure to be completely filled in.
This patch will make sure the network is filled in as much as possible.
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: James Ketrenos <jketreno@linux.intel.com>
results in a lot of duplicate code.
This will move the parsing stage into a seperate function.
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: James Ketrenos <jketreno@linux.intel.com>
net/ieee80211/ieee80211_tx.c:215:9: warning: implicit cast to nocast type
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: James Ketrenos <jketreno@linux.intel.com>
header, and I also added the ieee80211_is_cck_rate counterpart.
Various drivers currently create there own version of these functions,
but I guess the ieee80211 stack is the best place to provide such
routines.
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: James Ketrenos <jketreno@linux.intel.com>
From: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Handle better the case where the sender sends full sized
frames initially, then moves to a mode where it trickles
out small amounts of data at a time.
This known problem is even mentioned in the comments
above tcp_grow_window() in tcp_input.c, specifically:
...
* The scheme does not work when sender sends good segments opening
* window and then starts to feed us spagetti. But it should work
* in common situations. Otherwise, we have to rely on queue collapsing.
...
When the sender gives full sized frames, the "struct sk_buff" overhead
from each packet is small. So we'll advertize a larger window.
If the sender moves to a mode where small segments are sent, this
ratio becomes tilted to the other extreme and we start overrunning
the socket buffer space.
tcp_clamp_window() tries to address this, but it's clamping of
tp->window_clamp is a wee bit too aggressive for this particular case.
Fix confirmed by Ion Badulescu.
Signed-off-by: David S. Miller <davem@davemloft.net>
But retain the comment fix.
Alexey Kuznetsov has explained the situation as follows:
--------------------
I think the fix is incorrect. Look, the RFC function init_cwnd(mss) is
not continuous: f.e. for mss=1095 it needs initial window 1095*4, but
for mss=1096 it is 1096*3. We do not know exactly what mss sender used
for calculations. If we advertised 1096 (and calculate initial window
3*1096), the sender could limit it to some value < 1096 and then it
will need window his_mss*4 > 3*1096 to send initial burst.
See?
So, the honest function for inital rcv_wnd derived from
tcp_init_cwnd() is:
init_rcv_wnd(mss)=
min { init_cwnd(mss1)*mss1 for mss1 <= mss }
It is something sort of:
if (mss < 1096)
return mss*4;
if (mss < 1096*2)
return 1096*4;
return mss*2;
(I just scrablled a graph of piece of paper, it is difficult to see or
to explain without this)
I selected it differently giving more window than it is strictly
required. Initial receive window must be large enough to allow sender
following to the rfc (or just setting initial cwnd to 2) to send
initial burst. But besides that it is arbitrary, so I decided to give
slack space of one segment.
Actually, the logic was:
If mss is low/normal (<=ethernet), set window to receive more than
initial burst allowed by rfc under the worst conditions
i.e. mss*4. This gives slack space of 1 segment for ethernet frames.
For msses slighlty more than ethernet frame, take 3. Try to give slack
space of 1 frame again.
If mss is huge, force 2*mss. No slack space.
Value 1460*3 is really confusing. Minimal one is 1096*2, but besides
that it is an arbitrary value. It was meant to be ~4096. 1460*3 is
just the magic number from RFC, 1460*3 = 1095*4 is the magic :-), so
that I guess hands typed this themselves.
--------------------
Signed-off-by: David S. Miller <davem@davemloft.net>
A bunch of create_proc_dir_entry() calls creating directories had crept
in since the last sweep; converted to proc_mkdir().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
From: Oliver Dawid <oliver@helios.de>
we found a bug in net/appletalk/ddp.c concerning broadcast packets. In
kernel 2.4 it was working fine. The bug first occured 4 years ago when
switching to new SNAP layer handling. This bug can be splitted up into a
sending(1) and reception(2) problem:
Sending(1)
In kernel 2.4 broadcast packets were sent to a matching ethernet device
and atalk_rcv() was called to receive it as "loopback" (so loopback
packets were shortcutted and handled in DDP layer).
When switching to the new SNAP structure, this shortcut was removed and
the loopback packet was send to SNAP layer. The author forgot to replace
the remote device pointer by the loopback device pointer before sending
the packet to SNAP layer (by calling ddp_dl->request() ) therfor the
packet was not sent back by underlying layers to ddp's atalk_rcv().
Reception(2)
In atalk_rcv() a packet received by this loopback mechanism contains now
the (rigth) loopback device pointer (in Kernel 2.4 it was the (wrong)
remote ethernet device pointer) and therefor no matching socket will be
found to deliver this packet to. Because a broadcast packet should be
send to the first matching socket (as it is done in many other protocols
(?)), we removed the network comparison in broadcast case.
Below you will find a patch to correct this bug. Its diffed to kernel
2.6.14-rc1
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
We know the thing is at least 2-byte aligned, so take
advantage of that instead of invoking memcmp() which
results in truly horrifically inefficient code because
it can't assume anything about alignment.
Signed-off-by: David S. Miller <davem@davemloft.net>
* Don't bother with proto registering if rose_ndevs is bad.
* Make escape structure more coherent.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
I have been experimenting with loadable protocol modules, and ran into
several issues with module reference counting.
The first issue was that __module_get failed at the BUG_ON check at
the top of the routine (checking that my module reference count was
not zero) when I created the first socket. When sk_alloc() is called,
my module reference count was still 0. When I looked at why sctp
didn't have this problem, I discovered that sctp creates a control
socket during module init (when the module ref count is not 0), which
keeps the reference count non-zero. This section has been updated to
address the point Stephen raised about checking the return value of
try_module_get().
The next problem arose when my socket init routine returned an error.
This resulted in my module reference count being decremented below 0.
My socket ops->release routine was also being called. The issue here
is that sock_release() calls the ops->release routine and decrements
the ref count if sock->ops is not NULL. Since the socket probably
didn't get correctly initialized, this should not be done, so we will
set sock->ops to NULL because we will not call try_module_get().
While searching for another bug, I also noticed that sys_accept() has
a possibility of doing a module_put() when it did not do an
__module_get so I re-ordered the call to security_socket_accept().
Signed-off-by: Frank Filz <ffilzlnx@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use iteration instead of recursion. Fraglists within fraglists
should never occur, so we BUG check this.
Signed-off-by: Daniel Phillips <phillips@istop.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If we double-add a neighbour entry timer, which should be
impossible but has been reported, dump the current state of
the entry so that we can debug this.
Signed-off-by: David S. Miller <davem@davemloft.net>
When you've enabled conntrack and NAT as a module (standard case in all
distributions), and you've also enabled the new conntrack netlink
interface, loading ip_conntrack_netlink.ko will auto-load iptable_nat.ko.
This causes a huge performance penalty, since for every packet you iterate
the nat code, even if you don't want it.
This patch splits iptable_nat.ko into the NAT core (ip_nat.ko) and the
iptables frontend (iptable_nat.ko). Threfore, ip_conntrack_netlink.ko will
only pull ip_nat.ko, but not the frontend. ip_nat.ko will "only" allocate
some resources, but not affect runtime performance.
This separation is also a nice step in anticipation of new packet filters
(nf-hipac, ipset, pkttables) being able to use the NAT core.
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
These broke existing apps, and the checks are superfluous
as the values being verified aren't even used.
Signed-off-by: David S. Miller <davem@davemloft.net>
> Steps to reproduce:
> 1. Boot Linux, do NOT setup any IPv6 routes
> 2. ip route get 2001::1 (or any unroutable address)
Well caught. We never set rt6i_idev on ip6_null_entry.
This patch should make the problem go away.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
It's on the stack and declared as "unsigned char[]", but pointers
and similar can be in here thus we need to give it an explicit
alignment attribute.
Signed-off-by: Alex Williamson <alex.williamson@hp.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The GRE, SCTP and TCP protocol helpers did not call
ip_conntrack_event_cache() when updating ct->status. This patch adds
the respective calls.
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
From: Amos Waterland <apw@us.ibm.com>
If CONFIG_PROC_FS is not selected, the compiler emits this warning:
net/core/neighbour.c:64: warning: `neigh_stat_seq_fops' defined but not used
Which is correct, because neigh_stat_seq_fops is in fact only
initialized and used by code that is protected by CONFIG_PROC_FS. So
this patch fixes that up.
Signed-off-by: Amos Waterland <apw@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
We have to introduce a separate Kconfig menu entry for the NFQUEUE targets.
They cannot "just" depend on nfnetlink_queue, since nfnetlink_queue could
be linked into the kernel, whereas iptables can be a module.
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The in-kernel portmapper does in fact need a reserved port when registering
new services, but not when performing bind queries.
Ensure that we distinguish between the two cases.
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Currently rpc_mkdir/rpc_rmdir and rpc_mkpipe/mk_unlink have an API that's
a little unfortunate. They take a path relative to the rpc_pipefs root and
thus need to perform a full lookup. If you look at debugfs or usbfs they
always store the dentry for directories they created and thus can pass in
a dentry + single pathname component pair into their equivalents of the
above functions.
And in fact rpc_pipefs actually stores a dentry for all but one component so
this change not only simplifies the core rpc_pipe code but also the callers.
Unfortuntately this code path is only used by the NFS4 idmapper and
AUTH_GSSAPI for which I don't have a test enviroment. Could someone give
it a spin? It's the last bit needed before we can rework the
lookup_hash API
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
In fact, ->set_buffer_size should be completely functionless for non-UDP.
Test-plan:
Check socket buffer size on UDP sockets over time.
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Each transport implementation can now set unique bind, connect,
reestablishment, and idle timeout values. These are variables,
allowing the values to be modified dynamically. This permits
exponential backoff of any of these values, for instance.
As an example, we implement exponential backoff for the connection
reestablishment timeout.
Test-plan:
Destructive testing (unplugging the network temporarily). Connectathon
with UDP and TCP.
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Implement a best practice: if the remote end drops our connection, try to
reconnect using the same port number. This is important because the NFS
server's Duplicate Reply Cache often hashes on the source port number.
If the client reuses the port number when it reconnects, the server's DRC
will be more effective.
Based on suggestions by Mike Eisler, Olaf Kirch, and Alexey Kuznetsky.
Test-plan:
Destructive testing.
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Select an RPC client source port between 650 and 1023 instead of between
1 and 800. The old range conflicts with a number of network services.
Provide sysctls to allow admins to select a different port range.
Note that this doesn't affect user-level RPC library behavior, which
still uses 1 to 800.
Based on a suggestion by Olaf Kirch <okir@suse.de>.
Test-plan:
Repeated mount and unmount. Destructive testing. Idle timeouts.
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Clean-up: Move some macros that are specific to the Van Jacobson
implementation into xprt.c. Get rid of the cong_wait field in
rpc_xprt, which is no longer used. Get rid of xprt_clear_backlog.
Test-plan:
Compile with CONFIG_NFS enabled.
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Get rid of the "xprt->nocong" variable.
Test-plan:
Use WAN simulation to cause sporadic bursty packet loss with UDP mounts.
Look for significant regression in performance or client stability.
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The final place where congestion control state is adjusted is in
xprt_release, where each request is finally released. Add a callout
there to allow transports to perform additional processing when a
request is about to be released.
Test-plan:
Use WAN simulation to cause sporadic bursty packet loss. Look for significant
regression in performance or client stability.
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
A new interface that allows transports to adjust their congestion window
using the Van Jacobson implementation in xprt.c is provided.
Test-plan:
Use WAN simulation to cause sporadic bursty packet loss. Look for
significant regression in performance or client stability.
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Allow transports to hook the retransmit timer interrupt. Some transports
calculate their congestion window here so that a retransmit timeout has
immediate effect on the congestion window.
Test-plan:
Use WAN simulation to cause sporadic bursty packet loss. Look for significant
regression in performance or client stability.
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The next method we abstract is the one that releases a transport,
allowing another task to have access to the transport.
Again, one generic version of this is provided for transports that
don't need the RPC client to perform congestion control, and one
version is for transports that can use the original Van Jacobson
implementation in xprt.c.
Test-plan:
Use WAN simulation to cause sporadic bursty packet loss. Look for
significant regression in performance or client stability.
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The next several patches introduce an API that allows transports to
choose whether the RPC client provides congestion control or whether
the transport itself provides it.
The first method we abstract is the one that serializes access to the
RPC transport to prevent the bytes from different requests from mingling
together. This method provides proper request serialization and the
opportunity to prevent new requests from being started because the
transport is congested.
The normal situation is for the transport to handle congestion control
itself. Although NFS over UDP was first, it has been recognized after
years of experience that having the transport provide congestion control
is much better than doing it in the RPC client. Thus TCP, and probably
every future transport implementation, will use the default method,
xprt_lock_write, provided in xprt.c, which does not provide any kind
of congestion control. UDP can continue using the xprt.c-provided
Van Jacobson congestion avoidance implementation.
Test-plan:
Use WAN simulation to cause sporadic bursty packet loss. Look for significant
regression in performance or client stability.
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Prepare the way to remove the "xprt->nocong" variable by adding a callout
to the RPC client transport switch API to handle setting RPC retransmit
timeouts.
Add a pair of generic helper functions that provide the ability to set a
simple fixed timeout, or to set a timeout based on the state of a round-
trip estimator.
Test-plan:
Use WAN simulation to cause sporadic bursty packet loss. Look for significant
regression in performance or client stability.
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Herbert Xu