History log of /net/ipv4/inet_fragment.c
Revision Date Author Comments
d70127e8a942364de8dd140fe73893efda363293 28-Oct-2014 Nikolay Aleksandrov <nikolay@redhat.com> inet: frags: remove the WARN_ON from inet_evict_bucket

The WARN_ON in inet_evict_bucket can be triggered by a valid case:
inet_frag_kill and inet_evict_bucket can be running in parallel on the
same queue which means that there has been at least one more ref added
by a previous inet_frag_find call, but inet_frag_kill can delete the
timer before inet_evict_bucket which will cause the WARN_ON() there to
trigger since we'll have refcnt!=1. Now, this case is valid because the
queue is being "killed" for some reason (removed from the chain list and
its timer deleted) so it will get destroyed in the end by one of the
inet_frag_put() calls which reaches 0 i.e. refcnt is still valid.

CC: Florian Westphal <fw@strlen.de>
CC: Eric Dumazet <eric.dumazet@gmail.com>
CC: Patrick McLean <chutzpah@gentoo.org>

Fixes: b13d3cbfb8e8 ("inet: frag: move eviction of queues to work queue")
Reported-by: Patrick McLean <chutzpah@gentoo.org>
Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
65ba1f1ec0eff1c25933468e1d238201c0c2cb29 28-Oct-2014 Nikolay Aleksandrov <nikolay@redhat.com> inet: frags: fix a race between inet_evict_bucket and inet_frag_kill

When the evictor is running it adds some chosen frags to a local list to
be evicted once the chain lock has been released but at the same time
the *frag_queue can be running for some of the same queues and it
may call inet_frag_kill which will wait on the chain lock and
will then delete the queue from the wrong list since it was added in the
eviction one. The fix is simple - check if the queue has the evict flag
set under the chain lock before deleting it, this is safe because the
evict flag is set only under that lock and having the flag set also means
that the queue has been detached from the chain list, so no need to delete
it again.
An important note to make is that we're safe w.r.t refcnt because
inet_frag_kill and inet_evict_bucket will sync on the del_timer operation
where only one of the two can succeed (or if the timer is executing -
none of them), the cases are:
1. inet_frag_kill succeeds in del_timer
- then the timer ref is removed, but inet_evict_bucket will not add
this queue to its expire list but will restart eviction in that chain
2. inet_evict_bucket succeeds in del_timer
- then the timer ref is kept until the evictor "expires" the queue, but
inet_frag_kill will remove the initial ref and will set
INET_FRAG_COMPLETE which will make the frag_expire fn just to remove
its ref.
In the end all of the queue users will do an inet_frag_put and the one
that reaches 0 will free it. The refcount balance should be okay.

CC: Florian Westphal <fw@strlen.de>
CC: Eric Dumazet <eric.dumazet@gmail.com>
CC: Patrick McLean <chutzpah@gentoo.org>

Fixes: b13d3cbfb8e8 ("inet: frag: move eviction of queues to work queue")
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Reported-by: Patrick McLean <chutzpah@gentoo.org>
Tested-by: Patrick McLean <chutzpah@gentoo.org>
Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
d4ad4d22e7ac6b8711b35d7e86eb29f03f8ac153 01-Aug-2014 Nikolay Aleksandrov <nikolay@redhat.com> inet: frags: use kmem_cache for inet_frag_queue

Use kmem_cache to allocate/free inet_frag_queue objects since they're
all the same size per inet_frags user and are alloced/freed in high volumes
thus making it a perfect case for kmem_cache.

Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2e404f632f44979ddf0ce0808a438249a72d7015 01-Aug-2014 Nikolay Aleksandrov <nikolay@redhat.com> inet: frags: use INET_FRAG_EVICTED to prevent icmp messages

Now that we have INET_FRAG_EVICTED we might as well use it to stop
sending icmp messages in the "frag_expire" functions instead of
stripping INET_FRAG_FIRST_IN from their flags when evicting.
Also fix the comment style in ip6_expire_frag_queue().

Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
f926e23660d52601089222cb4755aabc693ca390 01-Aug-2014 Nikolay Aleksandrov <nikolay@redhat.com> inet: frags: fix function declaration alignments in inet_fragment

Fix a couple of functions' declaration alignments.

Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
06aa8b8a0345c78f4d9a1fb3f852952b12a0e40c 01-Aug-2014 Nikolay Aleksandrov <nikolay@redhat.com> inet: frags: rename last_in to flags

The last_in field has been used to store various flags different from
first/last frag in so give it a more descriptive name: flags.

Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
ab1c724f633080ed2e8a0cfe61654599b55cf8f9 24-Jul-2014 Florian Westphal <fw@strlen.de> inet: frag: use seqlock for hash rebuild

rehash is rare operation, don't force readers to take
the read-side rwlock.

Instead, we only have to detect the (rare) case where
the secret was altered while we are trying to insert
a new inetfrag queue into the table.

If it was changed, drop the bucket lock and recompute
the hash to get the 'new' chain bucket that we have to
insert into.

Joint work with Nikolay Aleksandrov.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
e3a57d18b06179d68fcf7a0a06ad844493c65e06 24-Jul-2014 Florian Westphal <fw@strlen.de> inet: frag: remove periodic secret rebuild timer

merge functionality into the eviction workqueue.

Instead of rebuilding every n seconds, take advantage of the upper
hash chain length limit.

If we hit it, mark table for rebuild and schedule workqueue.
To prevent frequent rebuilds when we're completely overloaded,
don't rebuild more than once every 5 seconds.

ipfrag_secret_interval sysctl is now obsolete and has been marked as
deprecated, it still can be changed so scripts won't be broken but it
won't have any effect. A comment is left above each unused secret_timer
variable to avoid confusion.

Joint work with Nikolay Aleksandrov.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
3fd588eb90bfbba17091381006ecafe29c45db4a 24-Jul-2014 Florian Westphal <fw@strlen.de> inet: frag: remove lru list

no longer used.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
434d305405ab86414f6ea3f261307d443a2c3506 24-Jul-2014 Florian Westphal <fw@strlen.de> inet: frag: don't account number of fragment queues

The 'nqueues' counter is protected by the lru list lock,
once thats removed this needs to be converted to atomic
counter. Given this isn't used for anything except for
reporting it to userspace via /proc, just remove it.

We still report the memory currently used by fragment
reassembly queues.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
b13d3cbfb8e8a8f53930af67d1ebf05149f32c24 24-Jul-2014 Florian Westphal <fw@strlen.de> inet: frag: move eviction of queues to work queue

When the high_thresh limit is reached we try to toss the 'oldest'
incomplete fragment queues until memory limits are below the low_thresh
value. This happens in softirq/packet processing context.

This has two drawbacks:

1) processors might evict a queue that was about to be completed
by another cpu, because they will compete wrt. resource usage and
resource reclaim.

2) LRU list maintenance is expensive.

But when constantly overloaded, even the 'least recently used' element is
recent, so removing 'lru' queue first is not 'fairer' than removing any
other fragment queue.

This moves eviction out of the fast path:

When the low threshold is reached, a work queue is scheduled
which then iterates over the table and removes the queues that exceed
the memory limits of the namespace. It sets a new flag called
INET_FRAG_EVICTED on the evicted queues so the proper counters will get
incremented when the queue is forcefully expired.

When the high threshold is reached, no more fragment queues are
created until we're below the limit again.

The LRU list is now unused and will be removed in a followup patch.

Joint work with Nikolay Aleksandrov.

Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
86e93e470cadedda9181a2bd9aee1d9d2e5e9c0f 24-Jul-2014 Florian Westphal <fw@strlen.de> inet: frag: move evictor calls into frag_find function

First step to move eviction handling into a work queue.

We lose two spots that accounted evicted fragments in MIB counters.

Accounting will be restored since the upcoming work-queue evictor
invokes the frag queue timer callbacks instead.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
fb3cfe6e75b9d05c87265e85e67d7caf6e5b44a7 24-Jul-2014 Florian Westphal <fw@strlen.de> inet: frag: remove hash size assumptions from callers

hide actual hash size from individual users: The _find
function will now fold the given hash value into the required range.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
e588e2f286ed7da011ed357c24c5b9a554e26595 06-Mar-2014 Florian Westphal <fw@strlen.de> inet: frag: make sure forced eviction removes all frags

Quoting Alexander Aring:
While fragmentation and unloading of 6lowpan module I got this kernel Oops
after few seconds:

BUG: unable to handle kernel paging request at f88bbc30
[..]
Modules linked in: ipv6 [last unloaded: 6lowpan]
Call Trace:
[<c012af4c>] ? call_timer_fn+0x54/0xb3
[<c012aef8>] ? process_timeout+0xa/0xa
[<c012b66b>] run_timer_softirq+0x140/0x15f

Problem is that incomplete frags are still around after unload; when
their frag expire timer fires, we get crash.

When a netns is removed (also done when unloading module), inet_frag
calls the evictor with 'force' argument to purge remaining frags.

The evictor loop terminates when accounted memory ('work') drops to 0
or the lru-list becomes empty. However, the mem accounting is done
via percpu counters and may not be accurate, i.e. loop may terminate
prematurely.

Alter evictor to only stop once the lru list is empty when force is
requested.

Reported-by: Phoebe Buckheister <phoebe.buckheister@itwm.fraunhofer.de>
Reported-by: Alexander Aring <alex.aring@gmail.com>
Tested-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
24b9bf43e93e0edd89072da51cf1fab95fc69dec 03-Mar-2014 Nikolay Aleksandrov <nikolay@redhat.com> net: fix for a race condition in the inet frag code

I stumbled upon this very serious bug while hunting for another one,
it's a very subtle race condition between inet_frag_evictor,
inet_frag_intern and the IPv4/6 frag_queue and expire functions
(basically the users of inet_frag_kill/inet_frag_put).

What happens is that after a fragment has been added to the hash chain
but before it's been added to the lru_list (inet_frag_lru_add) in
inet_frag_intern, it may get deleted (either by an expired timer if
the system load is high or the timer sufficiently low, or by the
fraq_queue function for different reasons) before it's added to the
lru_list, then after it gets added it's a matter of time for the
evictor to get to a piece of memory which has been freed leading to a
number of different bugs depending on what's left there.

I've been able to trigger this on both IPv4 and IPv6 (which is normal
as the frag code is the same), but it's been much more difficult to
trigger on IPv4 due to the protocol differences about how fragments
are treated.

The setup I used to reproduce this is: 2 machines with 4 x 10G bonded
in a RR bond, so the same flow can be seen on multiple cards at the
same time. Then I used multiple instances of ping/ping6 to generate
fragmented packets and flood the machines with them while running
other processes to load the attacked machine.

*It is very important to have the _same flow_ coming in on multiple CPUs
concurrently. Usually the attacked machine would die in less than 30
minutes, if configured properly to have many evictor calls and timeouts
it could happen in 10 minutes or so.

An important point to make is that any caller (frag_queue or timer) of
inet_frag_kill will remove both the timer refcount and the
original/guarding refcount thus removing everything that's keeping the
frag from being freed at the next inet_frag_put. All of this could
happen before the frag was ever added to the LRU list, then it gets
added and the evictor uses a freed fragment.

An example for IPv6 would be if a fragment is being added and is at
the stage of being inserted in the hash after the hash lock is
released, but before inet_frag_lru_add executes (or is able to obtain
the lru lock) another overlapping fragment for the same flow arrives
at a different CPU which finds it in the hash, but since it's
overlapping it drops it invoking inet_frag_kill and thus removing all
guarding refcounts, and afterwards freeing it by invoking
inet_frag_put which removes the last refcount added previously by
inet_frag_find, then inet_frag_lru_add gets executed by
inet_frag_intern and we have a freed fragment in the lru_list.

The fix is simple, just move the lru_add under the hash chain locked
region so when a removing function is called it'll have to wait for
the fragment to be added to the lru_list, and then it'll remove it (it
works because the hash chain removal is done before the lru_list one
and there's no window between the two list adds when the frag can get
dropped). With this fix applied I couldn't kill the same machine in 24
hours with the same setup.

Fixes: 3ef0eb0db4bf ("net: frag, move LRU list maintenance outside of
rwlock")

CC: Florian Westphal <fw@strlen.de>
CC: Jesper Dangaard Brouer <brouer@redhat.com>
CC: David S. Miller <davem@davemloft.net>

Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
7088ad74e6e710d0c80ea2cead9500f47a2a5d58 23-Oct-2013 Hannes Frederic Sowa <hannes@stressinduktion.org> inet: remove old fragmentation hash initializing

All fragmentation hash secrets now get initialized by their
corresponding hash function with net_get_random_once. Thus we can
eliminate the initial seeding.

Also provide a comment that hash secret seeding happens at the first
call to the corresponding hashing function.

Cc: David S. Miller <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
0ed5fd138539940a493dc69359cb2f49de70ad89 04-Jul-2013 Jiang Liu <liuj97@gmail.com> mm: use totalram_pages instead of num_physpages at runtime

The global variable num_physpages is scheduled to be removed, so use
totalram_pages instead of num_physpages at runtime.

Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: James Morris <jmorris@namei.org>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Patrick McHardy <kaber@trash.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
af92e5425e4a7cfbc9b85dc268acfaadb551cc56 15-Jun-2013 Rami Rosen <ramirose@gmail.com> inet: frag , remove an empty ifdef.

This patch removes an empty ifdef from inet_frag_intern()
in net/ipv4/inet_fragment.c.

commit b67bfe0d42cac56c512dd5da4b1b347a23f4b70a
(hlist: drop the node parameter from iterators) removed hlist from
net/ipv4/inet_fragment.c, but did not remove the enclosing ifdef command,
which is now empty.

Signed-off-by: Rami Rosen <ramirose@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
b56141ab34e2c3e2d7960cea12c20c99530c0c76 05-May-2013 Konstantin Khlebnikov <khlebnikov@openvz.org> net: frag, fix race conditions in LRU list maintenance

This patch fixes race between inet_frag_lru_move() and inet_frag_lru_add()
which was introduced in commit 3ef0eb0db4bf92c6d2510fe5c4dc51852746f206
("net: frag, move LRU list maintenance outside of rwlock")

One cpu already added new fragment queue into hash but not into LRU.
Other cpu found it in hash and tries to move it to the end of LRU.
This leads to NULL pointer dereference inside of list_move_tail().

Another possible race condition is between inet_frag_lru_move() and
inet_frag_lru_del(): move can happens after deletion.

This patch initializes LRU list head before adding fragment into hash and
inet_frag_lru_move() doesn't touches it if it's empty.

I saw this kernel oops two times in a couple of days.

[119482.128853] BUG: unable to handle kernel NULL pointer dereference at (null)
[119482.132693] IP: [<ffffffff812ede89>] __list_del_entry+0x29/0xd0
[119482.136456] PGD 2148f6067 PUD 215ab9067 PMD 0
[119482.140221] Oops: 0000 [#1] SMP
[119482.144008] Modules linked in: vfat msdos fat 8021q fuse nfsd auth_rpcgss nfs_acl nfs lockd sunrpc ppp_async ppp_generic bridge slhc stp llc w83627ehf hwmon_vid snd_hda_codec_hdmi snd_hda_codec_realtek kvm_amd k10temp kvm snd_hda_intel snd_hda_codec edac_core radeon snd_hwdep ath9k snd_pcm ath9k_common snd_page_alloc ath9k_hw snd_timer snd soundcore drm_kms_helper ath ttm r8169 mii
[119482.152692] CPU 3
[119482.152721] Pid: 20, comm: ksoftirqd/3 Not tainted 3.9.0-zurg-00001-g9f95269 #132 To Be Filled By O.E.M. To Be Filled By O.E.M./RS880D
[119482.161478] RIP: 0010:[<ffffffff812ede89>] [<ffffffff812ede89>] __list_del_entry+0x29/0xd0
[119482.166004] RSP: 0018:ffff880216d5db58 EFLAGS: 00010207
[119482.170568] RAX: 0000000000000000 RBX: ffff88020882b9c0 RCX: dead000000200200
[119482.175189] RDX: 0000000000000000 RSI: 0000000000000880 RDI: ffff88020882ba00
[119482.179860] RBP: ffff880216d5db58 R08: ffffffff8155c7f0 R09: 0000000000000014
[119482.184570] R10: 0000000000000000 R11: 0000000000000000 R12: ffff88020882ba00
[119482.189337] R13: ffffffff81c8d780 R14: ffff880204357f00 R15: 00000000000005a0
[119482.194140] FS: 00007f58124dc700(0000) GS:ffff88021fcc0000(0000) knlGS:0000000000000000
[119482.198928] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[119482.203711] CR2: 0000000000000000 CR3: 00000002155f0000 CR4: 00000000000007e0
[119482.208533] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[119482.213371] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[119482.218221] Process ksoftirqd/3 (pid: 20, threadinfo ffff880216d5c000, task ffff880216d3a9a0)
[119482.223113] Stack:
[119482.228004] ffff880216d5dbd8 ffffffff8155dcda 0000000000000000 ffff000200000001
[119482.233038] ffff8802153c1f00 ffff880000289440 ffff880200000014 ffff88007bc72000
[119482.238083] 00000000000079d5 ffff88007bc72f44 ffffffff00000002 ffff880204357f00
[119482.243090] Call Trace:
[119482.248009] [<ffffffff8155dcda>] ip_defrag+0x8fa/0xd10
[119482.252921] [<ffffffff815a8013>] ipv4_conntrack_defrag+0x83/0xe0
[119482.257803] [<ffffffff8154485b>] nf_iterate+0x8b/0xa0
[119482.262658] [<ffffffff8155c7f0>] ? inet_del_offload+0x40/0x40
[119482.267527] [<ffffffff815448e4>] nf_hook_slow+0x74/0x130
[119482.272412] [<ffffffff8155c7f0>] ? inet_del_offload+0x40/0x40
[119482.277302] [<ffffffff8155d068>] ip_rcv+0x268/0x320
[119482.282147] [<ffffffff81519992>] __netif_receive_skb_core+0x612/0x7e0
[119482.286998] [<ffffffff81519b78>] __netif_receive_skb+0x18/0x60
[119482.291826] [<ffffffff8151a650>] process_backlog+0xa0/0x160
[119482.296648] [<ffffffff81519f29>] net_rx_action+0x139/0x220
[119482.301403] [<ffffffff81053707>] __do_softirq+0xe7/0x220
[119482.306103] [<ffffffff81053868>] run_ksoftirqd+0x28/0x40
[119482.310809] [<ffffffff81074f5f>] smpboot_thread_fn+0xff/0x1a0
[119482.315515] [<ffffffff81074e60>] ? lg_local_lock_cpu+0x40/0x40
[119482.320219] [<ffffffff8106d870>] kthread+0xc0/0xd0
[119482.324858] [<ffffffff8106d7b0>] ? insert_kthread_work+0x40/0x40
[119482.329460] [<ffffffff816c32dc>] ret_from_fork+0x7c/0xb0
[119482.334057] [<ffffffff8106d7b0>] ? insert_kthread_work+0x40/0x40
[119482.338661] Code: 00 00 55 48 8b 17 48 b9 00 01 10 00 00 00 ad de 48 8b 47 08 48 89 e5 48 39 ca 74 29 48 b9 00 02 20 00 00 00 ad de 48 39 c8 74 7a <4c> 8b 00 4c 39 c7 75 53 4c 8b 42 08 4c 39 c7 75 2b 48 89 42 08
[119482.343787] RIP [<ffffffff812ede89>] __list_del_entry+0x29/0xd0
[119482.348675] RSP <ffff880216d5db58>
[119482.353493] CR2: 0000000000000000

Oops happened on this path:
ip_defrag() -> ip_frag_queue() -> inet_frag_lru_move() -> list_move_tail() -> __list_del_entry()

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Florian Westphal <fw@strlen.de>
Cc: Eric Dumazet <edumazet@google.com>
Cc: David S. Miller <davem@davemloft.net>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
19952cc4f8f572493293a8caed27c4be89c5fc9d 04-Apr-2013 Jesper Dangaard Brouer <brouer@redhat.com> net: frag queue per hash bucket locking

This patch implements per hash bucket locking for the frag queue
hash. This removes two write locks, and the only remaining write
lock is for protecting hash rebuild. This essentially reduce the
readers-writer lock to a rebuild lock.

This patch is part of "net: frag performance followup"
http://thread.gmane.org/gmane.linux.network/263644
of which two patches have already been accepted:

Same test setup as previous:
(http://thread.gmane.org/gmane.linux.network/257155)
Two 10G interfaces, on seperate NUMA nodes, are under-test, and uses
Ethernet flow-control. A third interface is used for generating the
DoS attack (with trafgen).

Notice, I have changed the frag DoS generator script to be more
efficient/deadly. Before it would only hit one RX queue, now its
sending packets causing multi-queue RX, due to "better" RX hashing.

Test types summary (netperf UDP_STREAM):
Test-20G64K == 2x10G with 65K fragments
Test-20G3F == 2x10G with 3x fragments (3*1472 bytes)
Test-20G64K+DoS == Same as 20G64K with frag DoS
Test-20G3F+DoS == Same as 20G3F with frag DoS
Test-20G64K+MQ == Same as 20G64K with Multi-Queue frag DoS
Test-20G3F+MQ == Same as 20G3F with Multi-Queue frag DoS

When I rebased this-patch(03) (on top of net-next commit a210576c) and
removed the _bh spinlock, I saw a performance regression. BUT this
was caused by some unrelated change in-between. See tests below.

Test (A) is what I reported before for patch-02, accepted in commit 1b5ab0de.
Test (B) verifying-retest of commit 1b5ab0de corrospond to patch-02.
Test (C) is what I reported before for this-patch

Test (D) is net-next master HEAD (commit a210576c), which reveals some
(unknown) performance regression (compared against test (B)).
Test (D) function as a new base-test.

Performance table summary (in Mbit/s):

(#) Test-type: 20G64K 20G3F 20G64K+DoS 20G3F+DoS 20G64K+MQ 20G3F+MQ
---------- ------- ------- ---------- --------- -------- -------
(A) Patch-02 : 18848.7 13230.1 4103.04 5310.36 130.0 440.2
(B) 1b5ab0de : 18841.5 13156.8 4101.08 5314.57 129.0 424.2
(C) Patch-03v1: 18838.0 13490.5 4405.11 6814.72 196.6 461.6

(D) a210576c : 18321.5 11250.4 3635.34 5160.13 119.1 405.2
(E) with _bh : 17247.3 11492.6 3994.74 6405.29 166.7 413.6
(F) without bh: 17471.3 11298.7 3818.05 6102.11 165.7 406.3

Test (E) and (F) is this-patch(03), with(V1) and without(V2) the _bh spinlocks.

I cannot explain the slow down for 20G64K (but its an artificial
"lab-test" so I'm not worried). But the other results does show
improvements. And test (E) "with _bh" version is slightly better.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Eric Dumazet <edumazet@google.com>

----
V2:
- By analysis from Hannes Frederic Sowa and Eric Dumazet, we don't
need the spinlock _bh versions, as Netfilter currently does a
local_bh_disable() before entering inet_fragment.
- Fold-in desc from cover-mail
V3:
- Drop the chain_len counter per hash bucket.
Signed-off-by: David S. Miller <davem@davemloft.net>
1b5ab0def4f6e42e8b8097c3b11d2e8d96baafec 27-Mar-2013 Jesper Dangaard Brouer <brouer@redhat.com> net: use the frag lru_lock to protect netns_frags.nqueues update

Move the protection of netns_frags.nqueues updates under the LRU_lock,
instead of the write lock. As they are located on the same cacheline,
and this is also needed when transitioning to use per hash bucket locking.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
68399ac37e571c2d695ea3b08aa82235874b5158 27-Mar-2013 Jesper Dangaard Brouer <brouer@redhat.com> net: frag, avoid several CPUs grabbing same frag queue during LRU evictor loop

The LRU list is protected by its own lock, since commit 3ef0eb0db4
(net: frag, move LRU list maintenance outside of rwlock), and
no-longer by a read_lock.

This makes it possible, to remove the inet_frag_queue, which is about
to be "evicted", from the LRU list head. This avoids the problem, of
several CPUs grabbing the same frag queue.

Note, cannot remove the inet_frag_lru_del() call in fq_unlink()
called by inet_frag_kill(), because inet_frag_kill() is also used in
other situations. Thus, we use list_del_init() to allow this
double list_del to work.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
be991971d53e0f5b6d13e3940192054216590072 22-Mar-2013 Hannes Frederic Sowa <hannes@stressinduktion.org> inet: generalize ipv4-only RFC3168 5.3 ecn fragmentation handling for future use by ipv6

This patch just moves some code arround to make the ip4_frag_ecn_table
and IPFRAG_ECN_* constants accessible from the other reassembly engines. I
also renamed ip4_frag_ecn_table to ip_frag_ecn_table.

Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Jesper Dangaard Brouer <jbrouer@redhat.com>
Cc: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
5a3da1fe9561828d0ca7eca664b16ec2b9bf0055 15-Mar-2013 Hannes Frederic Sowa <hannes@stressinduktion.org> inet: limit length of fragment queue hash table bucket lists

This patch introduces a constant limit of the fragment queue hash
table bucket list lengths. Currently the limit 128 is choosen somewhat
arbitrary and just ensures that we can fill up the fragment cache with
empty packets up to the default ip_frag_high_thresh limits. It should
just protect from list iteration eating considerable amounts of cpu.

If we reach the maximum length in one hash bucket a warning is printed.
This is implemented on the caller side of inet_frag_find to distinguish
between the different users of inet_fragment.c.

I dropped the out of memory warning in the ipv4 fragment lookup path,
because we already get a warning by the slab allocator.

Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Jesper Dangaard Brouer <jbrouer@redhat.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
b67bfe0d42cac56c512dd5da4b1b347a23f4b70a 28-Feb-2013 Sasha Levin <sasha.levin@oracle.com> hlist: drop the node parameter from iterators

I'm not sure why, but the hlist for each entry iterators were conceived

list_for_each_entry(pos, head, member)

The hlist ones were greedy and wanted an extra parameter:

hlist_for_each_entry(tpos, pos, head, member)

Why did they need an extra pos parameter? I'm not quite sure. Not only
they don't really need it, it also prevents the iterator from looking
exactly like the list iterator, which is unfortunate.

Besides the semantic patch, there was some manual work required:

- Fix up the actual hlist iterators in linux/list.h
- Fix up the declaration of other iterators based on the hlist ones.
- A very small amount of places were using the 'node' parameter, this
was modified to use 'obj->member' instead.
- Coccinelle didn't handle the hlist_for_each_entry_safe iterator
properly, so those had to be fixed up manually.

The semantic patch which is mostly the work of Peter Senna Tschudin is here:

@@
iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host;

type T;
expression a,c,d,e;
identifier b;
statement S;
@@

-T b;
<+... when != b
(
hlist_for_each_entry(a,
- b,
c, d) S
|
hlist_for_each_entry_continue(a,
- b,
c) S
|
hlist_for_each_entry_from(a,
- b,
c) S
|
hlist_for_each_entry_rcu(a,
- b,
c, d) S
|
hlist_for_each_entry_rcu_bh(a,
- b,
c, d) S
|
hlist_for_each_entry_continue_rcu_bh(a,
- b,
c) S
|
for_each_busy_worker(a, c,
- b,
d) S
|
ax25_uid_for_each(a,
- b,
c) S
|
ax25_for_each(a,
- b,
c) S
|
inet_bind_bucket_for_each(a,
- b,
c) S
|
sctp_for_each_hentry(a,
- b,
c) S
|
sk_for_each(a,
- b,
c) S
|
sk_for_each_rcu(a,
- b,
c) S
|
sk_for_each_from
-(a, b)
+(a)
S
+ sk_for_each_from(a) S
|
sk_for_each_safe(a,
- b,
c, d) S
|
sk_for_each_bound(a,
- b,
c) S
|
hlist_for_each_entry_safe(a,
- b,
c, d, e) S
|
hlist_for_each_entry_continue_rcu(a,
- b,
c) S
|
nr_neigh_for_each(a,
- b,
c) S
|
nr_neigh_for_each_safe(a,
- b,
c, d) S
|
nr_node_for_each(a,
- b,
c) S
|
nr_node_for_each_safe(a,
- b,
c, d) S
|
- for_each_gfn_sp(a, c, d, b) S
+ for_each_gfn_sp(a, c, d) S
|
- for_each_gfn_indirect_valid_sp(a, c, d, b) S
+ for_each_gfn_indirect_valid_sp(a, c, d) S
|
for_each_host(a,
- b,
c) S
|
for_each_host_safe(a,
- b,
c, d) S
|
for_each_mesh_entry(a,
- b,
c, d) S
)
...+>

[akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c]
[akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c]
[akpm@linux-foundation.org: checkpatch fixes]
[akpm@linux-foundation.org: fix warnings]
[akpm@linux-foudnation.org: redo intrusive kvm changes]
Tested-by: Peter Senna Tschudin <peter.senna@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3ef0eb0db4bf92c6d2510fe5c4dc51852746f206 29-Jan-2013 Jesper Dangaard Brouer <brouer@redhat.com> net: frag, move LRU list maintenance outside of rwlock

Updating the fragmentation queues LRU (Least-Recently-Used) list,
required taking the hash writer lock. However, the LRU list isn't
tied to the hash at all, so we can use a separate lock for it.

Original-idea-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
6d7b857d541ecd1d9bd997c97242d4ef94b19de2 29-Jan-2013 Jesper Dangaard Brouer <brouer@redhat.com> net: use lib/percpu_counter API for fragmentation mem accounting

Replace the per network namespace shared atomic "mem" accounting
variable, in the fragmentation code, with a lib/percpu_counter.

Getting percpu_counter to scale to the fragmentation code usage
requires some tweaks.

At first view, percpu_counter looks superfast, but it does not
scale on multi-CPU/NUMA machines, because the default batch size
is too small, for frag code usage. Thus, I have adjusted the
batch size by using __percpu_counter_add() directly, instead of
percpu_counter_sub() and percpu_counter_add().

The batch size is increased to 130.000, based on the largest 64K
fragment memory usage. This does introduce some imprecise
memory accounting, but its does not need to be strict for this
use-case.

It is also essential, that the percpu_counter, does not
share cacheline with other writers, to make this scale.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
d433673e5f9180e05a770c4b2ab18c08ad51cc21 29-Jan-2013 Jesper Dangaard Brouer <brouer@redhat.com> net: frag helper functions for mem limit tracking

This change is primarily a preparation to ease the extension of memory
limit tracking.

The change does reduce the number atomic operation, during freeing of
a frag queue. This does introduce a some performance improvement, as
these atomic operations are at the core of the performance problems
seen on NUMA systems.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
6b102865e7ba9ff1e3c49c32c7187bb427d91798 18-Sep-2012 Amerigo Wang <amwang@redhat.com> ipv6: unify fragment thresh handling code

Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Michal Kubeček <mkubecek@suse.cz>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
54db0cc2ba0d38166acc2d6bae21721405305537 08-Jun-2012 Gao feng <gaofeng@cn.fujitsu.com> inetpeer: add parameter net for inet_getpeer_v4,v6

add struct net as a parameter of inet_getpeer_v[4,6],
use net to replace &init_net.

and modify some places to provide net for inet_getpeer_v[4,6]

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
4bc2f18ba4f22a90ab593c0a580fc9a19c4777b6 09-Jul-2010 Eric Dumazet <eric.dumazet@gmail.com> net/ipv4: 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>
5a0e3ad6af8660be21ca98a971cd00f331318c05 24-Mar-2010 Tejun Heo <tj@kernel.org> include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
56bca31ff1989aa8b60f717e984b0e624f06324e 25-Feb-2009 Hannes Eder <hannes@hanneseder.net> inet fragments: fix sparse warning: context imbalance

Impact: Attribute function with __releases(...)

Fix this sparse warning:
net/ipv4/inet_fragment.c:276:35: warning: context imbalance in 'inet_frag_find' - unexpected unlock

Signed-off-by: Hannes Eder <hannes@hanneseder.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
547b792cac0a038b9dbf958d3c120df3740b5572 26-Jul-2008 Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> 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>
9a375803feaadb6c34e0807bd9325885dcca5c00 28-Jun-2008 Pavel Emelyanov <xemul@openvz.org> inet fragments: fix race between inet_frag_find and inet_frag_secret_rebuild

The problem is that while we work w/o the inet_frags.lock even
read-locked the secret rebuild timer may occur (on another CPU, since
BHs are still disabled in the inet_frag_find) and change the rnd seed
for ipv4/6 fragments.

It was caused by my patch fd9e63544cac30a34c951f0ec958038f0529e244
([INET]: Omit double hash calculations in xxx_frag_intern) late
in the 2.6.24 kernel, so this should probably be queued to -stable.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
e8e16b706e8406f1ab3bccab16932ebc513896d8 29-Mar-2008 David S. Miller <davem@davemloft.net> [INET]: inet_frag_evictor() must run with BH disabled

Based upon a lockdep trace from Dave Jones.

Signed-off-by: David S. Miller <davem@davemloft.net>
bc578a54f0fd489d0722303f9a52508495ccaf9a 29-Mar-2008 Joe Perches <joe@perches.com> [NET]: Rename inet_frag.h identifiers COMPLETE, FIRST_IN, LAST_IN to INET_FRAG_*

On Fri, 2008-03-28 at 03:24 -0700, Andrew Morton wrote:
> they should all be renamed.

Done for include/net and net

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
81566e8322c3f6c6f9a2277fe0e440fee8d917bd 22-Jan-2008 Pavel Emelyanov <xemul@openvz.org> [NETNS][FRAGS]: Make the pernet subsystem for fragments.

On namespace start we mainly prepare the ctl variables.

When the namespace is stopped we have to kill all the fragments that
point to this namespace. The inet_frags_exit_net() handles it.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
3140c25c82106645a6b1fc469dab7006a1d09fd0 22-Jan-2008 Pavel Emelyanov <xemul@openvz.org> [NETNS][FRAGS]: Make the LRU list per namespace.

The inet_frags.lru_list is used for evicting only, so we have
to make it per-namespace, to evict only those fragments, who's
namespace exceeded its high threshold, but not the whole hash.
Besides, this helps to avoid long loops in evictor.

The spinlock is not per-namespace because it protects the
hash table as well, which is global.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
3b4bc4a2bfe80d01ebd4f2b6dcc58986c970ed16 22-Jan-2008 Pavel Emelyanov <xemul@openvz.org> [NETNS][FRAGS]: Isolate the secret interval from namespaces.

Since we have one hashtable to lookup the fragment, having
different secret_interval-s for hash rebuild doesn't make
sense, so move this one to inet_frags.

The inet_frags_ctl becomes empty after this, so remove it.
The appropriate ctl table is kept read-only in namespaces.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
e31e0bdc7e7fb9a4b09d2f3266c035a18fdcee9d 22-Jan-2008 Pavel Emelyanov <xemul@openvz.org> [NETNS][FRAGS]: Make thresholds work in namespaces.

This is the same as with the timeout variable.

Currently, after exceeding the high threshold _all_
the fragments are evicted, but it will be fixed in
later patch.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
b2fd5321dd160ef309dfb6cfc78ed8de4a830659 22-Jan-2008 Pavel Emelyanov <xemul@openvz.org> [NETNS][FRAGS]: Make the net.ipv4.ipfrag_timeout work in namespaces.

Move it to the netns_frags, adjust the usage and
make the appropriate ctl table writable.

Now fragment, that live in different namespaces can
live for different times.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
6ddc082223ef0f73717b4133fa7e648842bbfd02 22-Jan-2008 Pavel Emelyanov <xemul@openvz.org> [NETNS][FRAGS]: Make the mem counter per-namespace.

This is also simple, but introduces more changes, since
then mem counter is altered in more places.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
e5a2bb842cd9681d00d4ca963e63e4d3647e66f8 22-Jan-2008 Pavel Emelyanov <xemul@openvz.org> [NETNS][FRAGS]: Make the nqueues counter per-namespace.

This is simple - just move the variable from struct inet_frags
to struct netns_frags and adjust the usage appropriately.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
ac18e7509e7df327e30d6e073a787d922eaf211d 22-Jan-2008 Pavel Emelyanov <xemul@openvz.org> [NETNS][FRAGS]: Make the inet_frag_queue lookup work in namespaces.

Since fragment management code is consolidated, we cannot have the
pointer from inet_frag_queue to struct net, since we must know what
king of fragment this is.

So, I introduce the netns_frags structure. This one is currently
empty, but will be eventually filled with per-namespace
attributes. Each inet_frag_queue is tagged with this one.

The conntrack_reasm is not "netns-izated", so it has one static
netns_frags instance to keep working in init namespace.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
b24b8a247ff65c01b252025926fe564209fae4fc 24-Jan-2008 Pavel Emelyanov <xemul@openvz.org> [NET]: Convert init_timer into setup_timer

Many-many code in the kernel initialized the timer->function
and timer->data together with calling init_timer(timer). There
is already a helper for this. Use it for networking code.

The patch is HUGE, but makes the code 130 lines shorter
(98 insertions(+), 228 deletions(-)).

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
c95477090a2ace6d241c184adc3fbfcab9c61ceb 18-Oct-2007 Pavel Emelyanov <xemul@openvz.org> [INET]: Consolidate frag queues freeing

Since we now allocate the queues in inet_fragment.c, we
can safely free it in the same place. The ->destructor
callback thus becomes optional for inet_frags.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
48d60056387c37a17a46feda48613587a90535e5 18-Oct-2007 Pavel Emelyanov <xemul@openvz.org> [INET]: Remove no longer needed ->equal callback

Since this callback is used to check for conflicts in
hashtable when inserting a newly created frag queue, we can
do the same by checking for matching the queue with the
argument, used to create one.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
abd6523d15f40bfee14652619a31a7f65f77f581 18-Oct-2007 Pavel Emelyanov <xemul@openvz.org> [INET]: Consolidate xxx_find() in fragment management

Here we need another callback ->match to check whether the
entry found in hash matches the key passed. The key used
is the same as the creation argument for inet_frag_create.

Yet again, this ->match is the same for netfilter and ipv6.
Running a frew steps forward - this callback will later
replace the ->equal one.

Since the inet_frag_find() uses the already consolidated
inet_frag_create() remove the xxx_frag_create from protocol
codes.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
c6fda282294da882f8d8cc4c513940277dd380f5 18-Oct-2007 Pavel Emelyanov <xemul@openvz.org> [INET]: Consolidate xxx_frag_create()

This one uses the xxx_frag_intern() and xxx_frag_alloc()
routines, which are already consolidated, so remove them
from protocol code (as promised).

The ->constructor callback is used to init the rest of
the frag queue and it is the same for netfilter and ipv6.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
e521db9d790aaa60ae8920e21cb7faedc280fc36 18-Oct-2007 Pavel Emelyanov <xemul@openvz.org> [INET]: Consolidate xxx_frag_alloc()

Just perform the kzalloc() allocation and setup common
fields in the inet_frag_queue(). Then return the result
to the caller to initialize the rest.

The inet_frag_alloc() may return NULL, so check the
return value before doing the container_of(). This looks
ugly, but the xxx_frag_alloc() will be removed soon.

The xxx_expire() timer callbacks are patches,
because the argument is now the inet_frag_queue, not
the protocol specific queue.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2588fe1d782f1686847493ad643157d5d10bf602 18-Oct-2007 Pavel Emelyanov <xemul@openvz.org> [INET]: Consolidate xxx_frag_intern

This routine checks for the existence of a given entry
in the hash table and inserts the new one if needed.

The ->equal callback is used to compare two frag_queue-s
together, but this one is temporary and will be removed
later. The netfilter code and the ipv6 one use the same
routine to compare frags.

The inet_frag_intern() always returns non-NULL pointer,
so convert the inet_frag_queue into protocol specific
one (with the container_of) without any checks.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
8e7999c44ee95e1e90ac91c83557a04e2948f160 15-Oct-2007 Pavel Emelyanov <xemul@openvz.org> [INET]: Consolidate the xxx_evictor

The evictors collect some statistics for ipv4 and ipv6,
so make it return the number of evicted queues and account
them all at once in the caller.

The XXX_ADD_STATS_BH() macros are just for this case,
but maybe there are places in code, that can make use of
them as well.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
1e4b82873af0f21002e37a81ef063d2e5410deb3 15-Oct-2007 Pavel Emelyanov <xemul@openvz.org> [INET]: Consolidate the xxx_frag_destroy

To make in possible we need to know the exact frag queue
size for inet_frags->mem management and two callbacks:

* to destoy the skb (optional, used in conntracks only)
* to free the queue itself (mandatory, but later I plan to
move the allocation and the destruction of frag_queues
into the common place, so this callback will most likely
be optional too).

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
321a3a99e4717b960e21c62fc6a140d21453df7f 15-Oct-2007 Pavel Emelyanov <xemul@openvz.org> [INET]: Consolidate xxx_the secret_rebuild

This code works with the generic data types as well, so
move this into inet_fragment.c

This move makes it possible to hide the secret_timer
management and the secret_rebuild routine completely in
the inet_fragment.c

Introduce the ->hashfn() callback in inet_frags() to get
the hashfun for a given inet_frag_queue() object.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
277e650ddfc6944ef5f5466fd898b8da7f06cd82 15-Oct-2007 Pavel Emelyanov <xemul@openvz.org> [INET]: Consolidate the xxx_frag_kill

Since now all the xxx_frag_kill functions now work
with the generic inet_frag_queue data type, this can
be moved into a common place.

The xxx_unlink() code is moved as well.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
7eb95156d9dce2f59794264db336ce007d71638b 15-Oct-2007 Pavel Emelyanov <xemul@openvz.org> [INET]: Collect frag queues management objects together

There are some objects that are common in all the places
which are used to keep track of frag queues, they are:

* hash table
* LRU list
* rw lock
* rnd number for hash function
* the number of queues
* the amount of memory occupied by queues
* secret timer

Move all this stuff into one structure (struct inet_frags)
to make it possible use them uniformly in the future. Like
with the previous patch this mostly consists of hunks like

- write_lock(&ipfrag_lock);
+ write_lock(&ip4_frags.lock);

To address the issue with exporting the number of queues and
the amount of memory occupied by queues outside the .c file
they are declared in, I introduce a couple of helpers.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>