Commit Graph

75 Commits

Author SHA1 Message Date
Ursula Braun 82492a355f af_iucv: add shutdown for HS transport
AF_IUCV sockets offer a shutdown function. This patch makes sure
shutdown works for HS transport as well.

Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-03-07 22:52:24 -08:00
Ursula Braun 9fbd87d413 af_iucv: handle netdev events
In case of transport through HiperSockets the underlying network
interface may switch to DOWN state or the underlying network device
may recover. In both cases the socket must change to IUCV_DISCONN
state. If the interface goes down, af_iucv has a chance to notify
its connection peer in addition.

Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-03-07 22:52:24 -08:00
Ursula Braun 51363b8751 af_iucv: allow retrieval of maximum message size
For HS transport the maximum message size depends on the MTU-size
of the HS-device bound to the AF_IUCV socket. This patch adds a
getsockopt option MSGSIZE returning the maximum message size that
can be handled for this AF_IUCV socket.

Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-02-08 18:50:19 -05:00
Ursula Braun 800c5eb7b5 af_iucv: change net_device handling for HS transport
This patch saves the net_device in the iucv_sock structure during
bind in order to fasten skb sending.
In addition some other small improvements are made for HS transport:
   - error checking when sending skbs
   - locking changes in afiucv_hs_callback_txnotify
   - skb freeing in afiucv_hs_callback_txnotify
And finally it contains code cleanup to get rid of iucv_skb_queue_purge.

Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-02-08 18:50:19 -05:00
Ursula Braun 7f1b0ea42a af_iucv: block writing if msg limit is exceeded
When polling on an AF_IUCV socket, writing should be blocked if the
number of pending messages exceeds a defined limit.

Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-02-08 18:50:19 -05:00
Ursula Braun 7d316b9453 af_iucv: remove IUCV-pathes completely
A SEVER is missing in the callback of a receiving SEVERED. This may
inhibit z/VM to remove the corresponding IUCV-path completely.
This patch adds a SEVER in iucv_callback_connrej (together with
additional locking.

Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-02-08 18:50:19 -05:00
Ursula Braun aac6399c6a af_iucv: get rid of state IUCV_SEVERED
af_iucv differs unnecessarily between state IUCV_SEVERED and
IUCV_DISCONN. This patch removes state IUCV_SEVERED.
While simplifying af_iucv, this patch removes the 2nd invocation of
cpcmd as well.

Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-20 14:05:03 -05:00
Ursula Braun 9e8ba5f3ec af_iucv: remove unused timer infrastructure
af_iucv contains timer infrastructure which is not exploited.
This patch removes the timer related code parts.

Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-20 14:05:03 -05:00
Ursula Braun 816abbadf9 af_iucv: release reference to HS device
For HiperSockets transport skbs sent are bound to one of the
available HiperSockets devices. Add missing release of reference to
a HiperSockets device before freeing an skb.

Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-20 14:05:03 -05:00
Ursula Braun 42bd48e014 af_iucv: accelerate close for HS transport
Closing an af_iucv socket may wait for confirmation of outstanding
send requests. This patch adds confirmation code for the new
HiperSockets transport.

Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-20 14:05:03 -05:00
Ursula Braun c64d3f8f59 af_iucv: support ancillary data with HS transport
The AF_IUCV address family offers support for ancillary data.
This patch enables usage of ancillary data with the new
HiperSockets transport.

Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-20 14:05:03 -05:00
Eric Dumazet 87fb4b7b53 net: more accurate skb truesize
skb truesize currently accounts for sk_buff struct and part of skb head.
kmalloc() roundings are also ignored.

Considering that skb_shared_info is larger than sk_buff, its time to
take it into account for better memory accounting.

This patch introduces SKB_TRUESIZE(X) macro to centralize various
assumptions into a single place.

At skb alloc phase, we put skb_shared_info struct at the exact end of
skb head, to allow a better use of memory (lowering number of
reallocations), since kmalloc() gives us power-of-two memory blocks.

Unless SLUB/SLUB debug is active, both skb->head and skb_shared_info are
aligned to cache lines, as before.

Note: This patch might trigger performance regressions because of
misconfigured protocol stacks, hitting per socket or global memory
limits that were previously not reached. But its a necessary step for a
more accurate memory accounting.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Andi Kleen <ak@linux.intel.com>
CC: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-10-13 16:05:07 -04:00
Ursula Braun 3881ac441f af_iucv: add HiperSockets transport
The current transport mechanism for af_iucv is the z/VM offered
communications facility IUCV. To provide equivalent support when
running Linux in an LPAR, HiperSockets transport is added to the
AF_IUCV address family. It requires explicit binding of an AF_IUCV
socket to a HiperSockets device. A new packet_type ETH_P_AF_IUCV
is announced. An af_iucv specific transport header is defined
preceding the skb data. A small protocol is implemented for
connecting and for flow control/congestion management.

Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-08-13 01:10:16 -07:00
Ursula Braun 493d3971a6 af_iucv: cleanup - use iucv_sk(sk) early
Code cleanup making make use of local variable for struct iucv_sock.

Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-08-13 01:10:16 -07:00
Frank Blaschka 6fcd61f7bf af_iucv: use loadable iucv interface
For future af_iucv extensions the module should be able to run in LPAR
mode too. For this we use the new dynamic loading iucv interface.

Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-08-13 01:10:16 -07:00
Ursula Braun 9f6298a6ca af_iucv: get rid of compile warning
-Wunused-but-set-variable generates compile warnings. The affected
variables are removed.

Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13 14:55:21 -04:00
Lucas De Marchi 25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
Julia Lawall a56635a56f net/iucv: Add missing spin_unlock
Add a spin_unlock missing on the error path.  There seems like no reason
why the lock should continue to be held if the kzalloc fail.

The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression E1;
@@

* spin_lock(E1,...);
  <+... when != E1
  if (...) {
    ... when != E1
*   return ...;
  }
  ...+>
* spin_unlock(E1,...);
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-26 21:09:51 -07:00
Joe Perches 3fa21e07e6 net: Remove unnecessary returns from void function()s
This patch removes from net/ (but not any netfilter files)
all the unnecessary return; statements that precede the
last closing brace of void functions.

It does not remove the returns that are immediately
preceded by a label as gcc doesn't like that.

Done via:
$ grep -rP --include=*.[ch] -l "return;\n}" net/ | \
  xargs perl -i -e 'local $/ ; while (<>) { s/\n[ \t\n]+return;\n}/\n}/g; print; }'

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-17 23:23:14 -07:00
Eric Dumazet 4381548237 net: sock_def_readable() and friends RCU conversion
sk_callback_lock rwlock actually protects sk->sk_sleep pointer, so we
need two atomic operations (and associated dirtying) per incoming
packet.

RCU conversion is pretty much needed :

1) Add a new structure, called "struct socket_wq" to hold all fields
that will need rcu_read_lock() protection (currently: a
wait_queue_head_t and a struct fasync_struct pointer).

[Future patch will add a list anchor for wakeup coalescing]

2) Attach one of such structure to each "struct socket" created in
sock_alloc_inode().

3) Respect RCU grace period when freeing a "struct socket_wq"

4) Change sk_sleep pointer in "struct sock" by sk_wq, pointer to "struct
socket_wq"

5) Change sk_sleep() function to use new sk->sk_wq instead of
sk->sk_sleep

6) Change sk_has_sleeper() to wq_has_sleeper() that must be used inside
a rcu_read_lock() section.

7) Change all sk_has_sleeper() callers to :
  - Use rcu_read_lock() instead of read_lock(&sk->sk_callback_lock)
  - Use wq_has_sleeper() to eventually wakeup tasks.
  - Use rcu_read_unlock() instead of read_unlock(&sk->sk_callback_lock)

8) sock_wake_async() is modified to use rcu protection as well.

9) Exceptions :
  macvtap, drivers/net/tun.c, af_unix use integrated "struct socket_wq"
instead of dynamically allocated ones. They dont need rcu freeing.

Some cleanups or followups are probably needed, (possible
sk_callback_lock conversion to a spinlock for example...).

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-01 15:00:15 -07:00
Eric Dumazet aa39514516 net: sk_sleep() helper
Define a new function to return the waitqueue of a "struct sock".

static inline wait_queue_head_t *sk_sleep(struct sock *sk)
{
	return sk->sk_sleep;
}

Change all read occurrences of sk_sleep by a call to this function.

Needed for a future RCU conversion. sk_sleep wont be a field directly
available.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-20 16:37:13 -07:00
Alexey Dobriyan 471452104b const: constify remaining dev_pm_ops
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>
2009-12-15 08:53:25 -08:00
Eric Paris 3f378b6844 net: pass kern to net_proto_family create function
The generic __sock_create function has a kern argument which allows the
security system to make decisions based on if a socket is being created by
the kernel or by userspace.  This patch passes that flag to the
net_proto_family specific create function, so it can do the same thing.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-11-05 22:18:14 -08:00
Ursula Braun 9a4ff8d417 af_iucv: remove duplicate sock_set_flag
Remove duplicate sock_set_flag(sk, SOCK_ZAPPED) in iucv_sock_close,
which has been overlooked in September-commit
7514bab04e.

Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-17 23:57:20 -07:00
Hendrik Brueckner 49f5eba757 af_iucv: use sk functions to modify sk->sk_ack_backlog
Instead of modifying sk->sk_ack_backlog directly, use respective
socket functions.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-17 23:57:19 -07:00
Stephen Hemminger ec1b4cf74c net: mark net_proto_ops as const
All usages of structure net_proto_ops should be declared const.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-07 01:10:46 -07:00
David S. Miller b7058842c9 net: Make setsockopt() optlen be unsigned.
This provides safety against negative optlen at the type
level instead of depending upon (sometimes non-trivial)
checks against this sprinkled all over the the place, in
each and every implementation.

Based upon work done by Arjan van de Ven and feedback
from Linus Torvalds.

Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-30 16:12:20 -07:00
Hendrik Brueckner bf95d20fdb af_iucv: fix race when queueing skbs on the backlog queue
iucv_sock_recvmsg() and iucv_process_message()/iucv_fragment_skb race
for dequeuing an skb from the backlog queue.

If iucv_sock_recvmsg() dequeues first, iucv_process_message() calls
sock_queue_rcv_skb() with an skb that is NULL.

This results in the following kernel panic:

<1>Unable to handle kernel pointer dereference at virtual kernel address (null)
<4>Oops: 0004 [#1] PREEMPT SMP DEBUG_PAGEALLOC
<4>Modules linked in: af_iucv sunrpc qeth_l3 dm_multipath dm_mod vmur qeth ccwgroup
<4>CPU: 0 Not tainted 2.6.30 #4
<4>Process client-iucv (pid: 4787, task: 0000000034e75940, ksp: 00000000353e3710)
<4>Krnl PSW : 0704000180000000 000000000043ebca (sock_queue_rcv_skb+0x7a/0x138)
<4>           R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:0 CC:0 PM:0 EA:3
<4>Krnl GPRS: 0052900000000000 000003e0016e0fe8 0000000000000000 0000000000000000
<4>           000000000043eba8 0000000000000002 0000000000000001 00000000341aa7f0
<4>           0000000000000000 0000000000007800 0000000000000000 0000000000000000
<4>           00000000341aa7f0 0000000000594650 000000000043eba8 000000003fc2fb28
<4>Krnl Code: 000000000043ebbe: a7840006            brc     8,43ebca
<4>           000000000043ebc2: 5930c23c            c       %r3,572(%r12)
<4>           000000000043ebc6: a724004c            brc     2,43ec5e
<4>          >000000000043ebca: e3c0b0100024        stg     %r12,16(%r11)
<4>           000000000043ebd0: a7190000            lghi    %r1,0
<4>           000000000043ebd4: e310b0200024        stg     %r1,32(%r11)
<4>           000000000043ebda: c010ffffdce9        larl    %r1,43a5ac
<4>           000000000043ebe0: e310b0800024        stg     %r1,128(%r11)
<4>Call Trace:
<4>([<000000000043eba8>] sock_queue_rcv_skb+0x58/0x138)
<4> [<000003e0016bcf2a>] iucv_process_message+0x112/0x3cc [af_iucv]
<4> [<000003e0016bd3d4>] iucv_callback_rx+0x1f0/0x274 [af_iucv]
<4> [<000000000053a21a>] iucv_message_pending+0xa2/0x120
<4> [<000000000053b5a6>] iucv_tasklet_fn+0x176/0x1b8
<4> [<000000000014fa82>] tasklet_action+0xfe/0x1f4
<4> [<0000000000150a56>] __do_softirq+0x116/0x284
<4> [<0000000000111058>] do_softirq+0xe4/0xe8
<4> [<00000000001504ba>] irq_exit+0xba/0xd8
<4> [<000000000010e0b2>] do_extint+0x146/0x190
<4> [<00000000001184b6>] ext_no_vtime+0x1e/0x22
<4> [<00000000001fbf4e>] kfree+0x202/0x28c
<4>([<00000000001fbf44>] kfree+0x1f8/0x28c)
<4> [<000000000044205a>] __kfree_skb+0x32/0x124
<4> [<000003e0016bd8b2>] iucv_sock_recvmsg+0x236/0x41c [af_iucv]
<4> [<0000000000437042>] sock_aio_read+0x136/0x160
<4> [<0000000000205e50>] do_sync_read+0xe4/0x13c
<4> [<0000000000206dce>] vfs_read+0x152/0x15c
<4> [<0000000000206ed0>] SyS_read+0x54/0xac
<4> [<0000000000117c8e>] sysc_noemu+0x10/0x16
<4> [<00000042ff8def3c>] 0x42ff8def3c

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-16 20:57:39 -07:00
Hendrik Brueckner 7514bab04e af_iucv: do not call iucv_sock_kill() twice
For non-accepted sockets on the accept queue, iucv_sock_kill()
is called twice (in iucv_sock_close() and iucv_sock_cleanup_listen()).
This typically results in a kernel oops as shown below.

Remove the duplicate call to iucv_sock_kill() and set the SOCK_ZAPPED
flag in iucv_sock_close() only.

The iucv_sock_kill() function frees a socket only if the socket is zapped
and orphaned (sk->sk_socket == NULL):
  - Non-accepted sockets are always orphaned and, thus, iucv_sock_kill()
    frees the socket twice.
  - For accepted sockets or sockets created with iucv_sock_create(),
    sk->sk_socket is initialized. This caused the first call to
    iucv_sock_kill() to return immediately. To free these sockets,
    iucv_sock_release() uses sock_orphan() before calling iucv_sock_kill().

<1>Unable to handle kernel pointer dereference at virtual kernel address 000000003edd3000
<4>Oops: 0011 [#1] PREEMPT SMP DEBUG_PAGEALLOC
<4>Modules linked in: af_iucv sunrpc qeth_l3 dm_multipath dm_mod qeth vmur ccwgroup
<4>CPU: 0 Not tainted 2.6.30 #4
<4>Process iucv_sock_close (pid: 2486, task: 000000003aea4340, ksp: 000000003b75bc68)
<4>Krnl PSW : 0704200180000000 000003e00168e23a (iucv_sock_kill+0x2e/0xcc [af_iucv])
<4>           R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:0 CC:2 PM:0 EA:3
<4>Krnl GPRS: 0000000000000000 000000003b75c000 000000003edd37f0 0000000000000001
<4>           000003e00168ec62 000000003988d960 0000000000000000 000003e0016b0608
<4>           000000003fe81b20 000000003839bb58 00000000399977f0 000000003edd37f0
<4>           000003e00168b000 000003e00168f138 000000003b75bcd0 000000003b75bc98
<4>Krnl Code: 000003e00168e22a: c0c0ffffe6eb	larl	%r12,3e00168b000
<4>           000003e00168e230: b90400b2		lgr	%r11,%r2
<4>           000003e00168e234: e3e0f0980024	stg	%r14,152(%r15)
<4>          >000003e00168e23a: e310225e0090	llgc	%r1,606(%r2)
<4>           000003e00168e240: a7110001		tmll	%r1,1
<4>           000003e00168e244: a7840007		brc	8,3e00168e252
<4>           000003e00168e248: d507d00023c8	clc	0(8,%r13),968(%r2)
<4>           000003e00168e24e: a7840009		brc	8,3e00168e260
<4>Call Trace:
<4>([<000003e0016b0608>] afiucv_dbf+0x0/0xfffffffffffdea20 [af_iucv])
<4> [<000003e00168ec6c>] iucv_sock_close+0x130/0x368 [af_iucv]
<4> [<000003e00168ef02>] iucv_sock_release+0x5e/0xe4 [af_iucv]
<4> [<0000000000438e6c>] sock_release+0x44/0x104
<4> [<0000000000438f5e>] sock_close+0x32/0x50
<4> [<0000000000207898>] __fput+0xf4/0x250
<4> [<00000000002038aa>] filp_close+0x7a/0xa8
<4> [<00000000002039ba>] SyS_close+0xe2/0x148
<4> [<0000000000117c8e>] sysc_noemu+0x10/0x16
<4> [<00000042ff8deeac>] 0x42ff8deeac

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-16 20:57:38 -07:00
Hendrik Brueckner 56a73de388 af_iucv: handle non-accepted sockets after resuming from suspend
After resuming from suspend, all af_iucv sockets are disconnected.
Ensure that iucv_accept_dequeue() can handle disconnected sockets
which are not yet accepted.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-16 20:57:36 -07:00
Hendrik Brueckner d9973179ae af_iucv: fix race in __iucv_sock_wait()
Moving prepare_to_wait before the condition to avoid a race between
schedule_timeout and wake up.
The race can appear during iucv_sock_connect() and iucv_callback_connack().

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-16 20:57:35 -07:00
Alexey Dobriyan 5708e868dc net: constify remaining proto_ops
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-14 17:03:09 -07:00
Jiri Olsa a57de0b433 net: adding memory barrier to the poll and receive callbacks
Adding memory barrier after the poll_wait function, paired with
receive callbacks. Adding fuctions sock_poll_wait and sk_has_sleeper
to wrap the memory barrier.

Without the memory barrier, following race can happen.
The race fires, when following code paths meet, and the tp->rcv_nxt
and __add_wait_queue updates stay in CPU caches.

CPU1                         CPU2

sys_select                   receive packet
  ...                        ...
  __add_wait_queue           update tp->rcv_nxt
  ...                        ...
  tp->rcv_nxt check          sock_def_readable
  ...                        {
  schedule                      ...
                                if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
                                        wake_up_interruptible(sk->sk_sleep)
                                ...
                             }

If there was no cache the code would work ok, since the wait_queue and
rcv_nxt are opposit to each other.

Meaning that once tp->rcv_nxt is updated by CPU2, the CPU1 either already
passed the tp->rcv_nxt check and sleeps, or will get the new value for
tp->rcv_nxt and will return with new data mask.
In both cases the process (CPU1) is being added to the wait queue, so the
waitqueue_active (CPU2) call cannot miss and will wake up CPU1.

The bad case is when the __add_wait_queue changes done by CPU1 stay in its
cache, and so does the tp->rcv_nxt update on CPU2 side.  The CPU1 will then
endup calling schedule and sleep forever if there are no more data on the
socket.

Calls to poll_wait in following modules were ommited:
	net/bluetooth/af_bluetooth.c
	net/irda/af_irda.c
	net/irda/irnet/irnet_ppp.c
	net/mac80211/rc80211_pid_debugfs.c
	net/phonet/socket.c
	net/rds/af_rds.c
	net/rfkill/core.c
	net/sunrpc/cache.c
	net/sunrpc/rpc_pipe.c
	net/tipc/socket.c

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-09 17:06:57 -07:00
Linus Torvalds 5165aece0e 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: (43 commits)
  via-velocity: Fix velocity driver unmapping incorrect size.
  mlx4_en: Remove redundant refill code on RX
  mlx4_en: Removed redundant check on lso header size
  mlx4_en: Cancel port_up check in transmit function
  mlx4_en: using stop/start_all_queues
  mlx4_en: Removed redundant skb->len check
  mlx4_en: Counting all the dropped packets on the TX side
  usbnet cdc_subset: fix issues talking to PXA gadgets
  Net: qla3xxx, remove sleeping in atomic
  ipv4: fix NULL pointer + success return in route lookup path
  isdn: clean up documentation index
  cfg80211: validate station settings
  cfg80211: allow setting station parameters in mesh
  cfg80211: allow adding/deleting stations on mesh
  ath5k: fix beacon_int handling
  MAINTAINERS: Fix Atheros pattern paths
  ath9k: restore PS mode, before we put the chip into FULL SLEEP state.
  ath9k: wait for beacon frame along with CAB
  acer-wmi: fix rfkill conversion
  ath5k: avoid PCI FATAL interrupts by restoring RETRY_TIMEOUT disabling
  ...
2009-06-22 11:57:09 -07:00
Hendrik Brueckner 0ea920d211 af_iucv: Return -EAGAIN if iucv msg limit is exceeded
If the iucv message limit for a communication path is exceeded,
sendmsg() returns -EAGAIN instead of -EPIPE.
The calling application can then handle this error situtation,
e.g. to try again after waiting some time.

For blocking sockets, sendmsg() waits up to the socket timeout
before returning -EAGAIN. For the new wait condition, a macro
has been introduced and the iucv_sock_wait_state() has been
refactored to this macro.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-06-19 00:10:40 -07:00
Hendrik Brueckner bb664f49f8 af_iucv: Change if condition in sendmsg() for more readability
Change the if condition to exit sendmsg() if the socket in not connected.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-06-19 00:10:39 -07:00
Ursula Braun c23cad923b [S390] PM: af_iucv power management callbacks.
Patch establishes a dummy afiucv-device to make sure af_iucv is
notified as iucv-bus device about suspend/resume.

The PM freeze callback severs all iucv pathes of connected af_iucv sockets.
The PM thaw/restore callback switches the state of all previously connected
sockets to IUCV_DISCONN.

Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-06-16 10:31:19 +02:00
Ursula Braun d93fe1a144 af_iucv: Fix merge.
From: Ursula Braun <ubraun@linux.vnet.ibm.com>

net/iucv/af_iucv.c in net-next-2.6 is almost correct. 4 lines should
still be deleted. These are the remaining changes:

Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-23 06:37:16 -07:00
David S. Miller 5802b140ed Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	net/iucv/af_iucv.c
2009-04-23 04:08:24 -07:00
Hendrik Brueckner 09488e2e0f af_iucv: New socket option for setting IUCV MSGLIMITs
The SO_MSGLIMIT socket option modifies the message limit for new
IUCV communication paths.

The message limit specifies the maximum number of outstanding messages
that are allowed for connections. This setting can be lowered by z/VM
when an IUCV connection is established.

Expects an integer value in the range of 1 to 65535.
The default value is 65535.

The message limit must be set before calling connect() or listen()
for sockets.

If sockets are already connected or in state listen, changing the message
limit is not supported.
For reading the message limit value, unconnected sockets return the limit
that has been set or the default limit. For connected sockets, the actual
message limit is returned. The actual message limit is assigned by z/VM
for each connection and it depends on IUCV MSGLIMIT authorizations
specified for the z/VM guest virtual machine.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-23 04:04:38 -07:00
Hendrik Brueckner 802788bf90 af_iucv: cleanup and refactor recvmsg() EFAULT handling
If the skb cannot be copied to user iovec, always return -EFAULT.
The skb is enqueued again, except MSG_PEEK flag is set, to allow user space
applications to correct its iovec pointer.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-23 04:04:37 -07:00
Hendrik Brueckner aa8e71f58a af_iucv: Provide new socket type SOCK_SEQPACKET
This patch provides the socket type SOCK_SEQPACKET in addition to
SOCK_STREAM.

AF_IUCV sockets of type SOCK_SEQPACKET supports an 1:1 mapping of
socket read or write operations to complete IUCV messages.
Socket data or IUCV message data is not fragmented as this is the
case for SOCK_STREAM sockets.

The intention is to help application developers who write
applications or device drivers using native IUCV interfaces
(Linux kernel or z/VM IUCV interfaces).

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-23 04:04:36 -07:00
Hendrik Brueckner 44b1e6b5f9 af_iucv: Modify iucv msg target class using control msghdr
Allow 'classification' of socket data that is sent or received over
an af_iucv socket. For classification of data, the target class of an
(native) iucv message is used.

This patch provides the cmsg interface for iucv_sock_recvmsg() and
iucv_sock_sendmsg().  Applications can use the msg_control field of
struct msghdr to set or get the target class as a
"socket control message" (SCM/CMSG).

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-23 04:04:35 -07:00
Hendrik Brueckner b8942e3b6c af_iucv: Support data in IUCV msg parameter lists (IPRMDATA)
The patch allows to send and receive data in the parameter list of an
iucv message.
The parameter list is an arry of 8 bytes that are used by af_iucv as
follows:
	0..6  7 bytes for socket data and
	   7  1 byte to store the data length.

Instead of storing the data length directly, the difference
between 0xFF and the data length is used.
This convention does not interfere with the existing use of PRM
messages for shutting down the send direction of an AF_IUCV socket
(shutdown() operation).  Data lenghts greater than 7 (or PRM message
byte 8 is less than 0xF8) denotes to special messages.
Currently, the special SEND_SHUTDOWN message is supported only.

To use IPRM messages, both communicators must set the IUCV_IPRMDATA
flag during path negotiation, i.e. in iucv_connect() and
path_pending().

To be compatible to older af_iucv implementations, sending PRM
messages is controlled by the socket option SO_IPRMDATA_MSG.
Receiving PRM messages does not depend on the socket option (but
requires the IUCV_IPRMDATA path flag to be set).

Sending/Receiving data in the parameter list improves performance for
small amounts of data by reducing message_completion() interrupts and
memory copy operations.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-23 04:04:33 -07:00
Hendrik Brueckner 9d5c5d8f41 af_iucv: add sockopt() to enable/disable use of IPRM_DATA msgs
Provide the socket operations getsocktopt() and setsockopt() to enable/disable
sending of data in the parameter list of IUCV messages.
The patch sets respective flag only.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-23 04:04:32 -07:00
Hendrik Brueckner af88b52def af_iucv: sync sk shutdown flag if iucv path is quiesced
If the af_iucv communication partner quiesces the path to shutdown its
receive direction, provide a quiesce callback implementation to shutdown
the (local) send direction. This ensures that both sides are synchronized.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-23 04:04:30 -07:00
Hendrik Brueckner 3fa6b5adbe af_iucv: Fix race when queuing incoming iucv messages
AF_IUCV runs into a race when queuing incoming iucv messages
and receiving the resulting backlog.

If the Linux system is under pressure (high load or steal time),
the message queue grows up, but messages are not received and queued
onto the backlog queue. In that case, applications do not
receive any data with recvmsg() even if AF_IUCV puts incoming
messages onto the message queue.

The race can be avoided if the message queue spinlock in the
message_pending callback is spreaded across the entire callback
function.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-21 23:43:15 -07:00
Hendrik Brueckner e14ad5fa87 af_iucv: Test additional sk states in iucv_sock_shutdown
Add few more sk states in iucv_sock_shutdown().

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-21 23:43:15 -07:00
Hendrik Brueckner fe86e54ef9 af_iucv: Reject incoming msgs if RECV_SHUTDOWN is set
Reject incoming iucv messages if the receive direction has been shut down.
It avoids that the queue of outstanding messages increases and exceeds the
message limit of the iucv communication path.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-21 23:43:14 -07:00
Hendrik Brueckner 60d3705fcb af_iucv: fix oops in iucv_sock_recvmsg() for MSG_PEEK flag
If iucv_sock_recvmsg() is called with MSG_PEEK flag set, the skb is enqueued
twice. If the socket is then closed, the pointer to the skb is freed twice.

Remove the skb_queue_head() call for MSG_PEEK, because the skb_recv_datagram()
function already handles MSG_PEEK (does not dequeue the skb).

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-21 23:43:13 -07:00