linux/net/rxrpc/ar-transport.c
Tejun Heo 5a0e3ad6af 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>
2010-03-30 22:02:32 +09:00

278 lines
7.1 KiB
C

/* RxRPC point-to-point transport session management
*
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/module.h>
#include <linux/net.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <net/sock.h>
#include <net/af_rxrpc.h>
#include "ar-internal.h"
static void rxrpc_transport_reaper(struct work_struct *work);
static LIST_HEAD(rxrpc_transports);
static DEFINE_RWLOCK(rxrpc_transport_lock);
static unsigned long rxrpc_transport_timeout = 3600 * 24;
static DECLARE_DELAYED_WORK(rxrpc_transport_reap, rxrpc_transport_reaper);
/*
* allocate a new transport session manager
*/
static struct rxrpc_transport *rxrpc_alloc_transport(struct rxrpc_local *local,
struct rxrpc_peer *peer,
gfp_t gfp)
{
struct rxrpc_transport *trans;
_enter("");
trans = kzalloc(sizeof(struct rxrpc_transport), gfp);
if (trans) {
trans->local = local;
trans->peer = peer;
INIT_LIST_HEAD(&trans->link);
trans->bundles = RB_ROOT;
trans->client_conns = RB_ROOT;
trans->server_conns = RB_ROOT;
skb_queue_head_init(&trans->error_queue);
spin_lock_init(&trans->client_lock);
rwlock_init(&trans->conn_lock);
atomic_set(&trans->usage, 1);
trans->debug_id = atomic_inc_return(&rxrpc_debug_id);
if (peer->srx.transport.family == AF_INET) {
switch (peer->srx.transport_type) {
case SOCK_DGRAM:
INIT_WORK(&trans->error_handler,
rxrpc_UDP_error_handler);
break;
default:
BUG();
break;
}
} else {
BUG();
}
}
_leave(" = %p", trans);
return trans;
}
/*
* obtain a transport session for the nominated endpoints
*/
struct rxrpc_transport *rxrpc_get_transport(struct rxrpc_local *local,
struct rxrpc_peer *peer,
gfp_t gfp)
{
struct rxrpc_transport *trans, *candidate;
const char *new = "old";
int usage;
_enter("{%pI4+%hu},{%pI4+%hu},",
&local->srx.transport.sin.sin_addr,
ntohs(local->srx.transport.sin.sin_port),
&peer->srx.transport.sin.sin_addr,
ntohs(peer->srx.transport.sin.sin_port));
/* search the transport list first */
read_lock_bh(&rxrpc_transport_lock);
list_for_each_entry(trans, &rxrpc_transports, link) {
if (trans->local == local && trans->peer == peer)
goto found_extant_transport;
}
read_unlock_bh(&rxrpc_transport_lock);
/* not yet present - create a candidate for a new record and then
* redo the search */
candidate = rxrpc_alloc_transport(local, peer, gfp);
if (!candidate) {
_leave(" = -ENOMEM");
return ERR_PTR(-ENOMEM);
}
write_lock_bh(&rxrpc_transport_lock);
list_for_each_entry(trans, &rxrpc_transports, link) {
if (trans->local == local && trans->peer == peer)
goto found_extant_second;
}
/* we can now add the new candidate to the list */
trans = candidate;
candidate = NULL;
rxrpc_get_local(trans->local);
atomic_inc(&trans->peer->usage);
list_add_tail(&trans->link, &rxrpc_transports);
write_unlock_bh(&rxrpc_transport_lock);
new = "new";
success:
_net("TRANSPORT %s %d local %d -> peer %d",
new,
trans->debug_id,
trans->local->debug_id,
trans->peer->debug_id);
_leave(" = %p {u=%d}", trans, atomic_read(&trans->usage));
return trans;
/* we found the transport in the list immediately */
found_extant_transport:
usage = atomic_inc_return(&trans->usage);
read_unlock_bh(&rxrpc_transport_lock);
goto success;
/* we found the transport on the second time through the list */
found_extant_second:
usage = atomic_inc_return(&trans->usage);
write_unlock_bh(&rxrpc_transport_lock);
kfree(candidate);
goto success;
}
/*
* find the transport connecting two endpoints
*/
struct rxrpc_transport *rxrpc_find_transport(struct rxrpc_local *local,
struct rxrpc_peer *peer)
{
struct rxrpc_transport *trans;
_enter("{%pI4+%hu},{%pI4+%hu},",
&local->srx.transport.sin.sin_addr,
ntohs(local->srx.transport.sin.sin_port),
&peer->srx.transport.sin.sin_addr,
ntohs(peer->srx.transport.sin.sin_port));
/* search the transport list */
read_lock_bh(&rxrpc_transport_lock);
list_for_each_entry(trans, &rxrpc_transports, link) {
if (trans->local == local && trans->peer == peer)
goto found_extant_transport;
}
read_unlock_bh(&rxrpc_transport_lock);
_leave(" = NULL");
return NULL;
found_extant_transport:
atomic_inc(&trans->usage);
read_unlock_bh(&rxrpc_transport_lock);
_leave(" = %p", trans);
return trans;
}
/*
* release a transport session
*/
void rxrpc_put_transport(struct rxrpc_transport *trans)
{
_enter("%p{u=%d}", trans, atomic_read(&trans->usage));
ASSERTCMP(atomic_read(&trans->usage), >, 0);
trans->put_time = get_seconds();
if (unlikely(atomic_dec_and_test(&trans->usage))) {
_debug("zombie");
/* let the reaper determine the timeout to avoid a race with
* overextending the timeout if the reaper is running at the
* same time */
rxrpc_queue_delayed_work(&rxrpc_transport_reap, 0);
}
_leave("");
}
/*
* clean up a transport session
*/
static void rxrpc_cleanup_transport(struct rxrpc_transport *trans)
{
_net("DESTROY TRANS %d", trans->debug_id);
rxrpc_purge_queue(&trans->error_queue);
rxrpc_put_local(trans->local);
rxrpc_put_peer(trans->peer);
kfree(trans);
}
/*
* reap dead transports that have passed their expiry date
*/
static void rxrpc_transport_reaper(struct work_struct *work)
{
struct rxrpc_transport *trans, *_p;
unsigned long now, earliest, reap_time;
LIST_HEAD(graveyard);
_enter("");
now = get_seconds();
earliest = ULONG_MAX;
/* extract all the transports that have been dead too long */
write_lock_bh(&rxrpc_transport_lock);
list_for_each_entry_safe(trans, _p, &rxrpc_transports, link) {
_debug("reap TRANS %d { u=%d t=%ld }",
trans->debug_id, atomic_read(&trans->usage),
(long) now - (long) trans->put_time);
if (likely(atomic_read(&trans->usage) > 0))
continue;
reap_time = trans->put_time + rxrpc_transport_timeout;
if (reap_time <= now)
list_move_tail(&trans->link, &graveyard);
else if (reap_time < earliest)
earliest = reap_time;
}
write_unlock_bh(&rxrpc_transport_lock);
if (earliest != ULONG_MAX) {
_debug("reschedule reaper %ld", (long) earliest - now);
ASSERTCMP(earliest, >, now);
rxrpc_queue_delayed_work(&rxrpc_transport_reap,
(earliest - now) * HZ);
}
/* then destroy all those pulled out */
while (!list_empty(&graveyard)) {
trans = list_entry(graveyard.next, struct rxrpc_transport,
link);
list_del_init(&trans->link);
ASSERTCMP(atomic_read(&trans->usage), ==, 0);
rxrpc_cleanup_transport(trans);
}
_leave("");
}
/*
* preemptively destroy all the transport session records rather than waiting
* for them to time out
*/
void __exit rxrpc_destroy_all_transports(void)
{
_enter("");
rxrpc_transport_timeout = 0;
cancel_delayed_work(&rxrpc_transport_reap);
rxrpc_queue_delayed_work(&rxrpc_transport_reap, 0);
_leave("");
}