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IPVS: Use global mutex in ip_vs_app.c
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As part of the work to make IPVS network namespace aware
__ip_vs_app_mutex was replaced by a per-namespace lock,
ipvs->app_mutex. ipvs->app_key is also supplied for debugging purposes.

Unfortunately this implementation results in ipvs->app_key residing
in non-static storage which at the very least causes a lockdep warning.

This patch takes the rather heavy-handed approach of reinstating
__ip_vs_app_mutex which will cover access to the ipvs->list_head
of all network namespaces.

[   12.610000] IPVS: Creating netns size=2456 id=0
[   12.630000] IPVS: Registered protocols (TCP, UDP, SCTP, AH, ESP)
[   12.640000] BUG: key ffff880003bbf1a0 not in .data!
[   12.640000] ------------[ cut here ]------------
[   12.640000] WARNING: at kernel/lockdep.c:2701 lockdep_init_map+0x37b/0x570()
[   12.640000] Hardware name: Bochs
[   12.640000] Pid: 1, comm: swapper Tainted: G        W 2.6.38-kexec-06330-g69b7efe-dirty torvalds#122
[   12.650000] Call Trace:
[   12.650000]  [<ffffffff8102e685>] warn_slowpath_common+0x75/0xb0
[   12.650000]  [<ffffffff8102e6d5>] warn_slowpath_null+0x15/0x20
[   12.650000]  [<ffffffff8105967b>] lockdep_init_map+0x37b/0x570
[   12.650000]  [<ffffffff8105829d>] ? trace_hardirqs_on+0xd/0x10
[   12.650000]  [<ffffffff81055ad8>] debug_mutex_init+0x38/0x50
[   12.650000]  [<ffffffff8104bc4c>] __mutex_init+0x5c/0x70
[   12.650000]  [<ffffffff81685ee7>] __ip_vs_app_init+0x64/0x86
[   12.660000]  [<ffffffff81685a3b>] ? ip_vs_init+0x0/0xff
[   12.660000]  [<ffffffff811b1c33>] T.620+0x43/0x170
[   12.660000]  [<ffffffff811b1e9a>] ? register_pernet_subsys+0x1a/0x40
[   12.660000]  [<ffffffff81685a3b>] ? ip_vs_init+0x0/0xff
[   12.660000]  [<ffffffff81685a3b>] ? ip_vs_init+0x0/0xff
[   12.660000]  [<ffffffff811b1db7>] register_pernet_operations+0x57/0xb0
[   12.660000]  [<ffffffff81685a3b>] ? ip_vs_init+0x0/0xff
[   12.670000]  [<ffffffff811b1ea9>] register_pernet_subsys+0x29/0x40
[   12.670000]  [<ffffffff81685f19>] ip_vs_app_init+0x10/0x12
[   12.670000]  [<ffffffff81685a87>] ip_vs_init+0x4c/0xff
[   12.670000]  [<ffffffff8166562c>] do_one_initcall+0x7a/0x12e
[   12.670000]  [<ffffffff8166583e>] kernel_init+0x13e/0x1c2
[   12.670000]  [<ffffffff8128c134>] kernel_thread_helper+0x4/0x10
[   12.670000]  [<ffffffff8128ad40>] ? restore_args+0x0/0x30
[   12.680000]  [<ffffffff81665700>] ? kernel_init+0x0/0x1c2
[   12.680000]  [<ffffffff8128c130>] ? kernel_thread_helper+0x0/0x1global0

Signed-off-by: Simon Horman <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Eric Dumazet <[email protected]>
Cc: Julian Anastasov <[email protected]>
Cc: Hans Schillstrom <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
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@horms @davem330
horms authored and davem330 committed Mar 22, 2011
1 parent f40f94f commit 736561a
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Showing 2 changed files with 10 additions and 15 deletions.
2 changes: 0 additions & 2 deletions include/net/ip_vs.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -801,8 +801,6 @@ struct netns_ipvs {
struct list_head rs_table[IP_VS_RTAB_SIZE];
/* ip_vs_app */
struct list_head app_list;
struct mutex app_mutex;
struct lock_class_key app_key; /* mutex debuging */

/* ip_vs_proto */
#define IP_VS_PROTO_TAB_SIZE 32 /* must be power of 2 */
Expand Down
23 changes: 10 additions & 13 deletions net/netfilter/ipvs/ip_vs_app.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -43,6 +43,8 @@ EXPORT_SYMBOL(register_ip_vs_app);
EXPORT_SYMBOL(unregister_ip_vs_app);
EXPORT_SYMBOL(register_ip_vs_app_inc);

static DEFINE_MUTEX(__ip_vs_app_mutex);

/*
* Get an ip_vs_app object
*/
Expand Down Expand Up @@ -167,14 +169,13 @@ int
register_ip_vs_app_inc(struct net *net, struct ip_vs_app *app, __u16 proto,
__u16 port)
{
struct netns_ipvs *ipvs = net_ipvs(net);
int result;

mutex_lock(&ipvs->app_mutex);
mutex_lock(&__ip_vs_app_mutex);

result = ip_vs_app_inc_new(net, app, proto, port);

mutex_unlock(&ipvs->app_mutex);
mutex_unlock(&__ip_vs_app_mutex);

return result;
}
Expand All @@ -189,11 +190,11 @@ int register_ip_vs_app(struct net *net, struct ip_vs_app *app)
/* increase the module use count */
ip_vs_use_count_inc();

mutex_lock(&ipvs->app_mutex);
mutex_lock(&__ip_vs_app_mutex);

list_add(&app->a_list, &ipvs->app_list);

mutex_unlock(&ipvs->app_mutex);
mutex_unlock(&__ip_vs_app_mutex);

return 0;
}
Expand All @@ -205,18 +206,17 @@ int register_ip_vs_app(struct net *net, struct ip_vs_app *app)
*/
void unregister_ip_vs_app(struct net *net, struct ip_vs_app *app)
{
struct netns_ipvs *ipvs = net_ipvs(net);
struct ip_vs_app *inc, *nxt;

mutex_lock(&ipvs->app_mutex);
mutex_lock(&__ip_vs_app_mutex);

list_for_each_entry_safe(inc, nxt, &app->incs_list, a_list) {
ip_vs_app_inc_release(net, inc);
}

list_del(&app->a_list);

mutex_unlock(&ipvs->app_mutex);
mutex_unlock(&__ip_vs_app_mutex);

/* decrease the module use count */
ip_vs_use_count_dec();
Expand Down Expand Up @@ -501,7 +501,7 @@ static void *ip_vs_app_seq_start(struct seq_file *seq, loff_t *pos)
struct net *net = seq_file_net(seq);
struct netns_ipvs *ipvs = net_ipvs(net);

mutex_lock(&ipvs->app_mutex);
mutex_lock(&__ip_vs_app_mutex);

return *pos ? ip_vs_app_idx(ipvs, *pos - 1) : SEQ_START_TOKEN;
}
Expand Down Expand Up @@ -535,9 +535,7 @@ static void *ip_vs_app_seq_next(struct seq_file *seq, void *v, loff_t *pos)

static void ip_vs_app_seq_stop(struct seq_file *seq, void *v)
{
struct netns_ipvs *ipvs = net_ipvs(seq_file_net(seq));

mutex_unlock(&ipvs->app_mutex);
mutex_unlock(&__ip_vs_app_mutex);
}

static int ip_vs_app_seq_show(struct seq_file *seq, void *v)
Expand Down Expand Up @@ -583,7 +581,6 @@ static int __net_init __ip_vs_app_init(struct net *net)
struct netns_ipvs *ipvs = net_ipvs(net);

INIT_LIST_HEAD(&ipvs->app_list);
__mutex_init(&ipvs->app_mutex, "ipvs->app_mutex", &ipvs->app_key);
proc_net_fops_create(net, "ip_vs_app", 0, &ip_vs_app_fops);
return 0;
}
Expand Down

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