Messages in this thread Patch in this message | | | From | Wolfgang Walter <> | Subject | [patch] sunrpc: make closing of old temporary sockets work (was: problems with lockd in 2.6.22.6) | Date | Wed, 12 Sep 2007 14:07:10 +0200 |
| |
Hello,
as already described old temporary sockets (client is gone) of lockd aren't closed after some time. So, with enough clients and some time gone, there are 80 open dangling sockets and you start getting messages of the form:
lockd: too many open TCP sockets, consider increasing the number of nfsd threads.
If I understand the code then the intention was that the server closes temporary sockets after about 6 to 12 minutes:
a timer is started which calls svc_age_temp_sockets every 6 minutes.
svc_age_temp_sockets: if a socket is marked OLD it gets closed. sockets which are not marked as OLD are marked OLD
every time the sockets receives something OLD is cleared.
But svc_age_temp_sockets never closes any socket though because it only closes sockets with svsk->sk_inuse == 0. This seems to be a bug.
Here is a patch against 2.6.22.6 which changes the test to svsk->sk_inuse <= 0 which was probably meant. The patched kernel runs fine here. Unused sockets get closed (after 6 to 12 minutes)
Signed-off-by: Wolfgang Walter <wolfgang.walter@studentenwerk.mhn.de>
--- ../linux-2.6.22.6/net/sunrpc/svcsock.c 2007-08-27 18:10:14.000000000 +0200 +++ net/sunrpc/svcsock.c 2007-09-11 11:07:13.000000000 +0200 @@ -1572,7 +1575,7 @@ if (!test_and_set_bit(SK_OLD, &svsk->sk_flags)) continue; - if (atomic_read(&svsk->sk_inuse) || test_bit(SK_BUSY, &svsk->sk_flags)) + if (atomic_read(&svsk->sk_inuse) <= 0 || test_bit(SK_BUSY, &svsk->sk_flags)) continue; atomic_inc(&svsk->sk_inuse); list_move(le, &to_be_aged);
As svc_age_temp_sockets did not do anything before this change may trigger hidden bugs.
To be true I don't see why this check
(atomic_read(&svsk->sk_inuse) <= 0 || test_bit(SK_BUSY, &svsk->sk_flags)) is needed at all (it can only be an optimation) as this fields change after the check. In svc_tcp_accept there is no such check when a temporary socket is closed.
Regards, -- Wolfgang Walter Studentenwerk München Anstalt des öffentlichen Rechts - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |