linux-stable/net/tipc/bearer.c
dingtianhong d4cca39d90 tipc: avoid possible deadlock while enable and disable bearer
We met lockdep warning when enable and disable the bearer for commands such as:

tipc-config -netid=1234 -addr=1.1.3 -be=eth:eth0
tipc-config -netid=1234 -addr=1.1.3 -bd=eth:eth0

---------------------------------------------------

[  327.693595] ======================================================
[  327.693994] [ INFO: possible circular locking dependency detected ]
[  327.694519] 3.11.0-rc3-wwd-default #4 Tainted: G           O
[  327.694882] -------------------------------------------------------
[  327.695385] tipc-config/5825 is trying to acquire lock:
[  327.695754]  (((timer))#2){+.-...}, at: [<ffffffff8105be80>] del_timer_sync+0x0/0xd0
[  327.696018]
[  327.696018] but task is already holding lock:
[  327.696018]  (&(&b_ptr->lock)->rlock){+.-...}, at: [<ffffffffa02be58d>] bearer_disable+  0xdd/0x120 [tipc]
[  327.696018]
[  327.696018] which lock already depends on the new lock.
[  327.696018]
[  327.696018]
[  327.696018] the existing dependency chain (in reverse order) is:
[  327.696018]
[  327.696018] -> #1 (&(&b_ptr->lock)->rlock){+.-...}:
[  327.696018]        [<ffffffff810b3b4d>] validate_chain+0x6dd/0x870
[  327.696018]        [<ffffffff810b40bb>] __lock_acquire+0x3db/0x670
[  327.696018]        [<ffffffff810b4453>] lock_acquire+0x103/0x130
[  327.696018]        [<ffffffff814d65b1>] _raw_spin_lock_bh+0x41/0x80
[  327.696018]        [<ffffffffa02c5d48>] disc_timeout+0x18/0xd0 [tipc]
[  327.696018]        [<ffffffff8105b92a>] call_timer_fn+0xda/0x1e0
[  327.696018]        [<ffffffff8105bcd7>] run_timer_softirq+0x2a7/0x2d0
[  327.696018]        [<ffffffff8105379a>] __do_softirq+0x16a/0x2e0
[  327.696018]        [<ffffffff81053a35>] irq_exit+0xd5/0xe0
[  327.696018]        [<ffffffff81033005>] smp_apic_timer_interrupt+0x45/0x60
[  327.696018]        [<ffffffff814df4af>] apic_timer_interrupt+0x6f/0x80
[  327.696018]        [<ffffffff8100b70e>] arch_cpu_idle+0x1e/0x30
[  327.696018]        [<ffffffff810a039d>] cpu_idle_loop+0x1fd/0x280
[  327.696018]        [<ffffffff810a043e>] cpu_startup_entry+0x1e/0x20
[  327.696018]        [<ffffffff81031589>] start_secondary+0x89/0x90
[  327.696018]
[  327.696018] -> #0 (((timer))#2){+.-...}:
[  327.696018]        [<ffffffff810b33fe>] check_prev_add+0x43e/0x4b0
[  327.696018]        [<ffffffff810b3b4d>] validate_chain+0x6dd/0x870
[  327.696018]        [<ffffffff810b40bb>] __lock_acquire+0x3db/0x670
[  327.696018]        [<ffffffff810b4453>] lock_acquire+0x103/0x130
[  327.696018]        [<ffffffff8105bebd>] del_timer_sync+0x3d/0xd0
[  327.696018]        [<ffffffffa02c5855>] tipc_disc_delete+0x15/0x30 [tipc]
[  327.696018]        [<ffffffffa02be59f>] bearer_disable+0xef/0x120 [tipc]
[  327.696018]        [<ffffffffa02be74f>] tipc_disable_bearer+0x2f/0x60 [tipc]
[  327.696018]        [<ffffffffa02bfb32>] tipc_cfg_do_cmd+0x2e2/0x550 [tipc]
[  327.696018]        [<ffffffffa02c8c79>] handle_cmd+0x49/0xe0 [tipc]
[  327.696018]        [<ffffffff8143e898>] genl_family_rcv_msg+0x268/0x340
[  327.696018]        [<ffffffff8143ed30>] genl_rcv_msg+0x70/0xd0
[  327.696018]        [<ffffffff8143d4c9>] netlink_rcv_skb+0x89/0xb0
[  327.696018]        [<ffffffff8143e617>] genl_rcv+0x27/0x40
[  327.696018]        [<ffffffff8143d21e>] netlink_unicast+0x15e/0x1b0
[  327.696018]        [<ffffffff8143ddcf>] netlink_sendmsg+0x22f/0x400
[  327.696018]        [<ffffffff813f7836>] __sock_sendmsg+0x66/0x80
[  327.696018]        [<ffffffff813f7957>] sock_aio_write+0x107/0x120
[  327.696018]        [<ffffffff8117f76d>] do_sync_write+0x7d/0xc0
[  327.696018]        [<ffffffff8117fc56>] vfs_write+0x186/0x190
[  327.696018]        [<ffffffff811803e0>] SyS_write+0x60/0xb0
[  327.696018]        [<ffffffff814de852>] system_call_fastpath+0x16/0x1b
[  327.696018]
[  327.696018] other info that might help us debug this:
[  327.696018]
[  327.696018]  Possible unsafe locking scenario:
[  327.696018]
[  327.696018]        CPU0                    CPU1
[  327.696018]        ----                    ----
[  327.696018]   lock(&(&b_ptr->lock)->rlock);
[  327.696018]                                lock(((timer))#2);
[  327.696018]                                lock(&(&b_ptr->lock)->rlock);
[  327.696018]   lock(((timer))#2);
[  327.696018]
[  327.696018]  *** DEADLOCK ***
[  327.696018]
[  327.696018] 5 locks held by tipc-config/5825:
[  327.696018]  #0:  (cb_lock){++++++}, at: [<ffffffff8143e608>] genl_rcv+0x18/0x40
[  327.696018]  #1:  (genl_mutex){+.+.+.}, at: [<ffffffff8143ed66>] genl_rcv_msg+0xa6/0xd0
[  327.696018]  #2:  (config_mutex){+.+.+.}, at: [<ffffffffa02bf889>] tipc_cfg_do_cmd+0x39/ 0x550 [tipc]
[  327.696018]  #3:  (tipc_net_lock){++.-..}, at: [<ffffffffa02be738>] tipc_disable_bearer+ 0x18/0x60 [tipc]
[  327.696018]  #4:  (&(&b_ptr->lock)->rlock){+.-...}, at: [<ffffffffa02be58d>]             bearer_disable+0xdd/0x120 [tipc]
[  327.696018]
[  327.696018] stack backtrace:
[  327.696018] CPU: 2 PID: 5825 Comm: tipc-config Tainted: G           O 3.11.0-rc3-wwd-    default #4
[  327.696018] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
[  327.696018]  00000000ffffffff ffff880037fa77a8 ffffffff814d03dd 0000000000000000
[  327.696018]  ffff880037fa7808 ffff880037fa77e8 ffffffff810b1c4f 0000000037fa77e8
[  327.696018]  ffff880037fa7808 ffff880037e4db40 0000000000000000 ffff880037e4e318
[  327.696018] Call Trace:
[  327.696018]  [<ffffffff814d03dd>] dump_stack+0x4d/0xa0
[  327.696018]  [<ffffffff810b1c4f>] print_circular_bug+0x10f/0x120
[  327.696018]  [<ffffffff810b33fe>] check_prev_add+0x43e/0x4b0
[  327.696018]  [<ffffffff810b3b4d>] validate_chain+0x6dd/0x870
[  327.696018]  [<ffffffff81087a28>] ? sched_clock_cpu+0xd8/0x110
[  327.696018]  [<ffffffff810b40bb>] __lock_acquire+0x3db/0x670
[  327.696018]  [<ffffffff810b4453>] lock_acquire+0x103/0x130
[  327.696018]  [<ffffffff8105be80>] ? try_to_del_timer_sync+0x70/0x70
[  327.696018]  [<ffffffff8105bebd>] del_timer_sync+0x3d/0xd0
[  327.696018]  [<ffffffff8105be80>] ? try_to_del_timer_sync+0x70/0x70
[  327.696018]  [<ffffffffa02c5855>] tipc_disc_delete+0x15/0x30 [tipc]
[  327.696018]  [<ffffffffa02be59f>] bearer_disable+0xef/0x120 [tipc]
[  327.696018]  [<ffffffffa02be74f>] tipc_disable_bearer+0x2f/0x60 [tipc]
[  327.696018]  [<ffffffffa02bfb32>] tipc_cfg_do_cmd+0x2e2/0x550 [tipc]
[  327.696018]  [<ffffffff81218783>] ? security_capable+0x13/0x20
[  327.696018]  [<ffffffffa02c8c79>] handle_cmd+0x49/0xe0 [tipc]
[  327.696018]  [<ffffffff8143e898>] genl_family_rcv_msg+0x268/0x340
[  327.696018]  [<ffffffff8143ed30>] genl_rcv_msg+0x70/0xd0
[  327.696018]  [<ffffffff8143ecc0>] ? genl_lock+0x20/0x20
[  327.696018]  [<ffffffff8143d4c9>] netlink_rcv_skb+0x89/0xb0
[  327.696018]  [<ffffffff8143e608>] ? genl_rcv+0x18/0x40
[  327.696018]  [<ffffffff8143e617>] genl_rcv+0x27/0x40
[  327.696018]  [<ffffffff8143d21e>] netlink_unicast+0x15e/0x1b0
[  327.696018]  [<ffffffff81289d7c>] ? memcpy_fromiovec+0x6c/0x90
[  327.696018]  [<ffffffff8143ddcf>] netlink_sendmsg+0x22f/0x400
[  327.696018]  [<ffffffff813f7836>] __sock_sendmsg+0x66/0x80
[  327.696018]  [<ffffffff813f7957>] sock_aio_write+0x107/0x120
[  327.696018]  [<ffffffff813fe29c>] ? release_sock+0x8c/0xa0
[  327.696018]  [<ffffffff8117f76d>] do_sync_write+0x7d/0xc0
[  327.696018]  [<ffffffff8117fa24>] ? rw_verify_area+0x54/0x100
[  327.696018]  [<ffffffff8117fc56>] vfs_write+0x186/0x190
[  327.696018]  [<ffffffff811803e0>] SyS_write+0x60/0xb0
[  327.696018]  [<ffffffff814de852>] system_call_fastpath+0x16/0x1b

-----------------------------------------------------------------------

The problem is that the tipc_link_delete() will cancel the timer disc_timeout() when
the b_ptr->lock is hold, but the disc_timeout() still call b_ptr->lock to finish the
work, so the dead lock occurs.

We should unlock the b_ptr->lock when del the disc_timeout().

Remove link_timeout() still met the same problem, the patch:

http://article.gmane.org/gmane.network.tipc.general/4380

fix the problem, so no need to send patch for fix link_timeout() deadlock warming.

Signed-off-by: Wang Weidong <wangweidong1@huawei.com>
Signed-off-by: Ding Tianhong <dingtianhong@huawei.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-11 21:58:41 -07:00

511 lines
13 KiB
C

/*
* net/tipc/bearer.c: TIPC bearer code
*
* Copyright (c) 1996-2006, Ericsson AB
* Copyright (c) 2004-2006, 2010-2011, Wind River Systems
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the names of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include "core.h"
#include "config.h"
#include "bearer.h"
#include "discover.h"
#define MAX_ADDR_STR 60
static struct tipc_media *media_list[MAX_MEDIA];
static u32 media_count;
struct tipc_bearer tipc_bearers[MAX_BEARERS];
static void bearer_disable(struct tipc_bearer *b_ptr);
/**
* tipc_media_find - locates specified media object by name
*/
struct tipc_media *tipc_media_find(const char *name)
{
u32 i;
for (i = 0; i < media_count; i++) {
if (!strcmp(media_list[i]->name, name))
return media_list[i];
}
return NULL;
}
/**
* media_find_id - locates specified media object by type identifier
*/
static struct tipc_media *media_find_id(u8 type)
{
u32 i;
for (i = 0; i < media_count; i++) {
if (media_list[i]->type_id == type)
return media_list[i];
}
return NULL;
}
/**
* tipc_register_media - register a media type
*
* Bearers for this media type must be activated separately at a later stage.
*/
int tipc_register_media(struct tipc_media *m_ptr)
{
int res = -EINVAL;
write_lock_bh(&tipc_net_lock);
if ((strlen(m_ptr->name) + 1) > TIPC_MAX_MEDIA_NAME)
goto exit;
if (m_ptr->priority > TIPC_MAX_LINK_PRI)
goto exit;
if ((m_ptr->tolerance < TIPC_MIN_LINK_TOL) ||
(m_ptr->tolerance > TIPC_MAX_LINK_TOL))
goto exit;
if (media_count >= MAX_MEDIA)
goto exit;
if (tipc_media_find(m_ptr->name) || media_find_id(m_ptr->type_id))
goto exit;
media_list[media_count] = m_ptr;
media_count++;
res = 0;
exit:
write_unlock_bh(&tipc_net_lock);
if (res)
pr_warn("Media <%s> registration error\n", m_ptr->name);
return res;
}
/**
* tipc_media_addr_printf - record media address in print buffer
*/
void tipc_media_addr_printf(char *buf, int len, struct tipc_media_addr *a)
{
char addr_str[MAX_ADDR_STR];
struct tipc_media *m_ptr;
int ret;
m_ptr = media_find_id(a->media_id);
if (m_ptr && !m_ptr->addr2str(a, addr_str, sizeof(addr_str)))
ret = tipc_snprintf(buf, len, "%s(%s)", m_ptr->name, addr_str);
else {
u32 i;
ret = tipc_snprintf(buf, len, "UNKNOWN(%u)", a->media_id);
for (i = 0; i < sizeof(a->value); i++)
ret += tipc_snprintf(buf - ret, len + ret,
"-%02x", a->value[i]);
}
}
/**
* tipc_media_get_names - record names of registered media in buffer
*/
struct sk_buff *tipc_media_get_names(void)
{
struct sk_buff *buf;
int i;
buf = tipc_cfg_reply_alloc(MAX_MEDIA * TLV_SPACE(TIPC_MAX_MEDIA_NAME));
if (!buf)
return NULL;
read_lock_bh(&tipc_net_lock);
for (i = 0; i < media_count; i++) {
tipc_cfg_append_tlv(buf, TIPC_TLV_MEDIA_NAME,
media_list[i]->name,
strlen(media_list[i]->name) + 1);
}
read_unlock_bh(&tipc_net_lock);
return buf;
}
/**
* bearer_name_validate - validate & (optionally) deconstruct bearer name
* @name: ptr to bearer name string
* @name_parts: ptr to area for bearer name components (or NULL if not needed)
*
* Returns 1 if bearer name is valid, otherwise 0.
*/
static int bearer_name_validate(const char *name,
struct tipc_bearer_names *name_parts)
{
char name_copy[TIPC_MAX_BEARER_NAME];
char *media_name;
char *if_name;
u32 media_len;
u32 if_len;
/* copy bearer name & ensure length is OK */
name_copy[TIPC_MAX_BEARER_NAME - 1] = 0;
/* need above in case non-Posix strncpy() doesn't pad with nulls */
strncpy(name_copy, name, TIPC_MAX_BEARER_NAME);
if (name_copy[TIPC_MAX_BEARER_NAME - 1] != 0)
return 0;
/* ensure all component parts of bearer name are present */
media_name = name_copy;
if_name = strchr(media_name, ':');
if (if_name == NULL)
return 0;
*(if_name++) = 0;
media_len = if_name - media_name;
if_len = strlen(if_name) + 1;
/* validate component parts of bearer name */
if ((media_len <= 1) || (media_len > TIPC_MAX_MEDIA_NAME) ||
(if_len <= 1) || (if_len > TIPC_MAX_IF_NAME))
return 0;
/* return bearer name components, if necessary */
if (name_parts) {
strcpy(name_parts->media_name, media_name);
strcpy(name_parts->if_name, if_name);
}
return 1;
}
/**
* tipc_bearer_find - locates bearer object with matching bearer name
*/
struct tipc_bearer *tipc_bearer_find(const char *name)
{
struct tipc_bearer *b_ptr;
u32 i;
for (i = 0, b_ptr = tipc_bearers; i < MAX_BEARERS; i++, b_ptr++) {
if (b_ptr->active && (!strcmp(b_ptr->name, name)))
return b_ptr;
}
return NULL;
}
/**
* tipc_bearer_find_interface - locates bearer object with matching interface name
*/
struct tipc_bearer *tipc_bearer_find_interface(const char *if_name)
{
struct tipc_bearer *b_ptr;
char *b_if_name;
u32 i;
for (i = 0, b_ptr = tipc_bearers; i < MAX_BEARERS; i++, b_ptr++) {
if (!b_ptr->active)
continue;
b_if_name = strchr(b_ptr->name, ':') + 1;
if (!strcmp(b_if_name, if_name))
return b_ptr;
}
return NULL;
}
/**
* tipc_bearer_get_names - record names of bearers in buffer
*/
struct sk_buff *tipc_bearer_get_names(void)
{
struct sk_buff *buf;
struct tipc_bearer *b_ptr;
int i, j;
buf = tipc_cfg_reply_alloc(MAX_BEARERS * TLV_SPACE(TIPC_MAX_BEARER_NAME));
if (!buf)
return NULL;
read_lock_bh(&tipc_net_lock);
for (i = 0; i < media_count; i++) {
for (j = 0; j < MAX_BEARERS; j++) {
b_ptr = &tipc_bearers[j];
if (b_ptr->active && (b_ptr->media == media_list[i])) {
tipc_cfg_append_tlv(buf, TIPC_TLV_BEARER_NAME,
b_ptr->name,
strlen(b_ptr->name) + 1);
}
}
}
read_unlock_bh(&tipc_net_lock);
return buf;
}
void tipc_bearer_add_dest(struct tipc_bearer *b_ptr, u32 dest)
{
tipc_nmap_add(&b_ptr->nodes, dest);
tipc_bcbearer_sort();
tipc_disc_add_dest(b_ptr->link_req);
}
void tipc_bearer_remove_dest(struct tipc_bearer *b_ptr, u32 dest)
{
tipc_nmap_remove(&b_ptr->nodes, dest);
tipc_bcbearer_sort();
tipc_disc_remove_dest(b_ptr->link_req);
}
/*
* Interrupt enabling new requests after bearer blocking:
* See bearer_send().
*/
void tipc_continue(struct tipc_bearer *b)
{
spin_lock_bh(&b->lock);
b->blocked = 0;
spin_unlock_bh(&b->lock);
}
/*
* tipc_bearer_blocked - determines if bearer is currently blocked
*/
int tipc_bearer_blocked(struct tipc_bearer *b)
{
int res;
spin_lock_bh(&b->lock);
res = b->blocked;
spin_unlock_bh(&b->lock);
return res;
}
/**
* tipc_enable_bearer - enable bearer with the given name
*/
int tipc_enable_bearer(const char *name, u32 disc_domain, u32 priority)
{
struct tipc_bearer *b_ptr;
struct tipc_media *m_ptr;
struct tipc_bearer_names b_names;
char addr_string[16];
u32 bearer_id;
u32 with_this_prio;
u32 i;
int res = -EINVAL;
if (!tipc_own_addr) {
pr_warn("Bearer <%s> rejected, not supported in standalone mode\n",
name);
return -ENOPROTOOPT;
}
if (!bearer_name_validate(name, &b_names)) {
pr_warn("Bearer <%s> rejected, illegal name\n", name);
return -EINVAL;
}
if (tipc_addr_domain_valid(disc_domain) &&
(disc_domain != tipc_own_addr)) {
if (tipc_in_scope(disc_domain, tipc_own_addr)) {
disc_domain = tipc_own_addr & TIPC_CLUSTER_MASK;
res = 0; /* accept any node in own cluster */
} else if (in_own_cluster_exact(disc_domain))
res = 0; /* accept specified node in own cluster */
}
if (res) {
pr_warn("Bearer <%s> rejected, illegal discovery domain\n",
name);
return -EINVAL;
}
if ((priority > TIPC_MAX_LINK_PRI) &&
(priority != TIPC_MEDIA_LINK_PRI)) {
pr_warn("Bearer <%s> rejected, illegal priority\n", name);
return -EINVAL;
}
write_lock_bh(&tipc_net_lock);
m_ptr = tipc_media_find(b_names.media_name);
if (!m_ptr) {
pr_warn("Bearer <%s> rejected, media <%s> not registered\n",
name, b_names.media_name);
goto exit;
}
if (priority == TIPC_MEDIA_LINK_PRI)
priority = m_ptr->priority;
restart:
bearer_id = MAX_BEARERS;
with_this_prio = 1;
for (i = MAX_BEARERS; i-- != 0; ) {
if (!tipc_bearers[i].active) {
bearer_id = i;
continue;
}
if (!strcmp(name, tipc_bearers[i].name)) {
pr_warn("Bearer <%s> rejected, already enabled\n",
name);
goto exit;
}
if ((tipc_bearers[i].priority == priority) &&
(++with_this_prio > 2)) {
if (priority-- == 0) {
pr_warn("Bearer <%s> rejected, duplicate priority\n",
name);
goto exit;
}
pr_warn("Bearer <%s> priority adjustment required %u->%u\n",
name, priority + 1, priority);
goto restart;
}
}
if (bearer_id >= MAX_BEARERS) {
pr_warn("Bearer <%s> rejected, bearer limit reached (%u)\n",
name, MAX_BEARERS);
goto exit;
}
b_ptr = &tipc_bearers[bearer_id];
strcpy(b_ptr->name, name);
res = m_ptr->enable_bearer(b_ptr);
if (res) {
pr_warn("Bearer <%s> rejected, enable failure (%d)\n",
name, -res);
goto exit;
}
b_ptr->identity = bearer_id;
b_ptr->media = m_ptr;
b_ptr->tolerance = m_ptr->tolerance;
b_ptr->window = m_ptr->window;
b_ptr->net_plane = bearer_id + 'A';
b_ptr->active = 1;
b_ptr->priority = priority;
INIT_LIST_HEAD(&b_ptr->links);
spin_lock_init(&b_ptr->lock);
res = tipc_disc_create(b_ptr, &b_ptr->bcast_addr, disc_domain);
if (res) {
bearer_disable(b_ptr);
pr_warn("Bearer <%s> rejected, discovery object creation failed\n",
name);
goto exit;
}
pr_info("Enabled bearer <%s>, discovery domain %s, priority %u\n",
name,
tipc_addr_string_fill(addr_string, disc_domain), priority);
exit:
write_unlock_bh(&tipc_net_lock);
return res;
}
/**
* tipc_block_bearer - Block the bearer with the given name, and reset all its links
*/
int tipc_block_bearer(const char *name)
{
struct tipc_bearer *b_ptr = NULL;
struct tipc_link *l_ptr;
struct tipc_link *temp_l_ptr;
read_lock_bh(&tipc_net_lock);
b_ptr = tipc_bearer_find(name);
if (!b_ptr) {
pr_warn("Attempt to block unknown bearer <%s>\n", name);
read_unlock_bh(&tipc_net_lock);
return -EINVAL;
}
pr_info("Blocking bearer <%s>\n", name);
spin_lock_bh(&b_ptr->lock);
b_ptr->blocked = 1;
list_for_each_entry_safe(l_ptr, temp_l_ptr, &b_ptr->links, link_list) {
struct tipc_node *n_ptr = l_ptr->owner;
spin_lock_bh(&n_ptr->lock);
tipc_link_reset(l_ptr);
spin_unlock_bh(&n_ptr->lock);
}
spin_unlock_bh(&b_ptr->lock);
read_unlock_bh(&tipc_net_lock);
return 0;
}
/**
* bearer_disable
*
* Note: This routine assumes caller holds tipc_net_lock.
*/
static void bearer_disable(struct tipc_bearer *b_ptr)
{
struct tipc_link *l_ptr;
struct tipc_link *temp_l_ptr;
struct tipc_link_req *temp_req;
pr_info("Disabling bearer <%s>\n", b_ptr->name);
spin_lock_bh(&b_ptr->lock);
b_ptr->blocked = 1;
b_ptr->media->disable_bearer(b_ptr);
list_for_each_entry_safe(l_ptr, temp_l_ptr, &b_ptr->links, link_list) {
tipc_link_delete(l_ptr);
}
temp_req = b_ptr->link_req;
b_ptr->link_req = NULL;
spin_unlock_bh(&b_ptr->lock);
if (temp_req)
tipc_disc_delete(temp_req);
memset(b_ptr, 0, sizeof(struct tipc_bearer));
}
int tipc_disable_bearer(const char *name)
{
struct tipc_bearer *b_ptr;
int res;
write_lock_bh(&tipc_net_lock);
b_ptr = tipc_bearer_find(name);
if (b_ptr == NULL) {
pr_warn("Attempt to disable unknown bearer <%s>\n", name);
res = -EINVAL;
} else {
bearer_disable(b_ptr);
res = 0;
}
write_unlock_bh(&tipc_net_lock);
return res;
}
void tipc_bearer_stop(void)
{
u32 i;
for (i = 0; i < MAX_BEARERS; i++) {
if (tipc_bearers[i].active)
bearer_disable(&tipc_bearers[i]);
}
media_count = 0;
}