From: Edwin Török <edvin.to...@citrix.com>
On a 16 node virtual cluster with e1000 NICs joining the 12th node prints
SYN flood warnings for the DLM port:
Dec 21 01:46:41 localhost kernel: [ 2146.516664] TCP: request_sock_TCP:
Possible SYN flooding on port 21064. Sending cookies. Check SNMP counters.
And then joining a DLM lockspace hangs:
```
Dec 21 01:49:00 localhost kernel: [ 2285.780913] INFO: task xapi-clusterd:17638
blocked for more than 120 seconds.
Dec 21 01:49:00 localhost kernel: [ 2285.786476] Not tainted 4.4.0+10 #1
Dec 21 01:49:00 localhost kernel: [ 2285.789043] "echo 0 >
/proc/sys/kernel/hung_task_timeout_secs" disables this message.
Dec 21 01:49:00 localhost kernel: [ 2285.794611] xapi-clusterd D
ffff88001930bc58 0 17638 1 0x00000000
Dec 21 01:49:00 localhost kernel: [ 2285.794615] ffff88001930bc58
ffff880025593800 ffff880022433800 ffff88001930c000
Dec 21 01:49:00 localhost kernel: [ 2285.794617] ffff88000ef4a660
ffff88000ef4a658 ffff880022433800 ffff88000ef4a000
Dec 21 01:49:00 localhost kernel: [ 2285.794619] ffff88001930bc70
ffffffff8159f6b4 7fffffffffffffff ffff88001930bd10
Dec 21 01:49:00 localhost kernel: [ 2285.794644] [<ffffffff811570fe>] ?
printk+0x4d/0x4f
Dec 21 01:49:00 localhost kernel: [ 2285.794647] [<ffffffff810b1741>] ?
__raw_callee_save___pv_queued_spin_unlock+0x11/0x20
Dec 21 01:49:00 localhost kernel: [ 2285.794649] [<ffffffff815a085d>]
wait_for_completion+0x9d/0x110
Dec 21 01:49:00 localhost kernel: [ 2285.794653] [<ffffffff810979e0>] ?
wake_up_q+0x80/0x80
Dec 21 01:49:00 localhost kernel: [ 2285.794661] [<ffffffffa03fa4b8>]
dlm_new_lockspace+0x908/0xac0 [dlm]
Dec 21 01:49:00 localhost kernel: [ 2285.794665] [<ffffffff810aaa60>] ?
prepare_to_wait_event+0x100/0x100
Dec 21 01:49:00 localhost kernel: [ 2285.794670] [<ffffffffa0402e37>]
device_write+0x497/0x6b0 [dlm]
Dec 21 01:49:00 localhost kernel: [ 2285.794673] [<ffffffff811834f0>] ?
handle_mm_fault+0x7f0/0x13b0
Dec 21 01:49:00 localhost kernel: [ 2285.794677] [<ffffffff811b4438>]
__vfs_write+0x28/0xd0
Dec 21 01:49:00 localhost kernel: [ 2285.794679] [<ffffffff811b4b7f>] ?
rw_verify_area+0x6f/0xd0
Dec 21 01:49:00 localhost kernel: [ 2285.794681] [<ffffffff811b4dc1>]
vfs_write+0xb1/0x190
Dec 21 01:49:00 localhost kernel: [ 2285.794686] [<ffffffff8105ffc2>] ?
__do_page_fault+0x302/0x420
Dec 21 01:49:00 localhost kernel: [ 2285.794688] [<ffffffff811b5986>]
SyS_write+0x46/0xa0
Dec 21 01:49:00 localhost kernel: [ 2285.794690] [<ffffffff815a31ae>]
entry_SYSCALL_64_fastpath+0x12/0x71
```
The previous limit of 5 seems like an arbitrary number, that doesn't match any
known DLM cluster size upper bound limit.
Signed-off-by: Edwin Török <edvin.to...@citrix.com>
Cc: Christine Caulfield <ccaul...@redhat.com>
Cc: David Teigland <teigl...@redhat.com>
Cc: cluster-devel@redhat.com
Signed-off-by: Alexander Aring <aahri...@redhat.com>
---
fs/dlm/lowcomms.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c
index c06dd1988259..d56155063dee 100644
--- a/fs/dlm/lowcomms.c
+++ b/fs/dlm/lowcomms.c
@@ -1814,7 +1814,7 @@ static int dlm_listen_for_all(void)
sock->sk->sk_data_ready = lowcomms_listen_data_ready;
release_sock(sock->sk);
- result = sock->ops->listen(sock, 5);
+ result = sock->ops->listen(sock, 128);
if (result < 0) {
dlm_close_sock(&listen_con.sock);
return result;
--
2.31.1
