[Ocfs2-devel] o2net_sendpage reviews, thanks

[Zhangguanghui]

Hi

1.  In the callback o2net_sendpage -> sendpage()
2.  If sendpage (tcp socket send) continuously returns -EAGAIN, then get into an endless loop,
    even though the function of cond_resched() have already used.
3.  I think it is not reasonable, try to continuously send 20 times returns -EAGAIN ,
    shutdown the socket to avoid affecting the entire cluster.

Finally, any feedback about this process (positive or negative) would be greatly appreciated.

--- tcp.c   2015-06-30 11:46:54.727447919 +0800

+++ tcp.c.diff  2015-06-30 11:52:12.823447881 +0800

@@ -949,6 +949,7 @@

 {

    struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);

    ssize_t ret;

+   int send_fails = 20;

    while (1) {

        mutex_lock(&sc->sc_send_lock);

@@ -959,10 +960,11 @@

        mutex_unlock(&sc->sc_send_lock);

        if (ret == size)

            break;

-       if (ret == (ssize_t)-EAGAIN) {

+       if (ret == (ssize_t)-EAGAIN && send_fails > 0) {

            mlog(0, "sendpage of size %zu to " SC_NODEF_FMT

                 " returned EAGAIN\n", size, SC_NODEF_ARGS(sc));

            cond_resched();

+           --send_fails;

            continue;

        }
        mlog(ML_ERROR, "sendpage of size %zu to " SC_NODEF_FMT


syslog:

/var/log/syslog:Jun 29 09:32:58 cvk47 kernel: [156022.769539] (kworker/u130:1,12041,9):o2net_sendpage:1026 sendpage of size 24 to node cvk61 (num 5) at 172.16.202.61:7100 returned EAGAIN

/var/log/syslog:Jun 29 09:32:58 cvk47 kernel: [156022.769542] (kworker/u130:1,12041,9):o2net_sendpage:1026 sendpage of size 24 to node cvk61 (num 5) at 172.16.202.61:7100 returned EAGAIN

/var/log/syslog:Jun 29 09:32:58 cvk47 kernel: [156022.769544] (kworker/u130:1,12041,9):o2net_sendpage:1026 sendpage of size 24 to node cvk61 (num 5) at 172.16.202.61:7100 returned EAGAIN

/var/log/syslog:Jun 29 09:32:58 cvk47 kernel: [156022.769546] (kworker/u130:1,12041,9):o2net_sendpage:1026 sendpage of

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zhangguanghui 10102
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