Re: [PATCH v2] char-socket: initialize reconnect timer only when the timer doesn't start

["Marc-André Lureau" <marcandre.lureau@redhat.com>]

Hi

On Tue, Apr 28, 2020 at 10:59 AM Li Feng <fengli@smartx.com> wrote:
>
> Sorry for sending the weird same mail out.
> Ignore the second one.
>
> Hi Lureau,
>
> I found another issue when running my new test:  tests/test-char -p
> /char/socket/client/reconnect-error/unix
> The backtrace like this:
> #0  0x00007ffff5ac3277 in raise () from /lib64/libc.so.6
> #1  0x00007ffff5ac4968 in abort () from /lib64/libc.so.6
> #2  0x00005555555aaa34 in error_handle_fatal (errp=<optimized out>,
> err=0x7fffec0012d0) at util/error.c:40
> #3  0x00005555555aab0d in error_setv (errp=0x555555802a08
> <error_abort>, src=0x5555555c4220 "io/channel.c", line=148,
> func=0x5555555c4520 <__func__.17450> "qio_channel_readv_all",
>     err_class=ERROR_CLASS_GENERIC_ERROR, fmt=<optimized out>,
> ap=0x7ffff423bb10, suffix=0x0) at util/error.c:73
> #4  0x00005555555aac90 in error_setg_internal
> (errp=errp@entry=0x555555802a08 <error_abort>,
> src=src@entry=0x5555555c4220 "io/channel.c", line=line@entry=148,
>     func=func@entry=0x5555555c4520 <__func__.17450>
> "qio_channel_readv_all", fmt=fmt@entry=0x5555555c4340 "Unexpected
> end-of-file before all bytes were read") at util/error.c:97
> #5  0x000055555556c1fc in qio_channel_readv_all (ioc=<optimized out>,
> iov=<optimized out>, niov=<optimized out>, errp=0x555555802a08
> <error_abort>) at io/channel.c:147
> #6  0x000055555556c23a in qio_channel_read_all (ioc=<optimized out>,
> buf=<optimized out>, buflen=<optimized out>, errp=<optimized out>) at
> io/channel.c:247
> #7  0x000055555556ad0e in char_socket_ping_pong (ioc=0x7fffec0008c0)
> at tests/test-char.c:727
> #8  0x000055555556adcf in char_socket_client_server_thread
> (data=data@entry=0x55555582e350) at tests/test-char.c:881
> #9  0x00005555555a9556 in qemu_thread_start (args=<optimized out>) at
> util/qemu-thread-posix.c:519
> #10 0x00007ffff5e61e25 in start_thread () from /lib64/libpthread.so.0
> #11 0x00007ffff5b8bbad in clone () from /lib64/libc.so.6
>
> I think this is a new issue of qemu, not my test issue.
> How do you think?


No idea, it could be a bug in the test itself. How did you produce it?

>
> Thanks,
>
> Feng Li
>
> Li Feng <fengli@smartx.com> 于2020年4月28日周二 下午4:53写道：
>
> >
> > When the disconnect event is triggered in the connecting stage,
> > the tcp_chr_disconnect_locked may be called twice.
> >
> > The first call:
> >     #0  qemu_chr_socket_restart_timer (chr=0x55555582ee90) at chardev/char-socket.c:120
> >     #1  0x000055555558e38c in tcp_chr_disconnect_locked (chr=<optimized out>) at chardev/char-socket.c:490
> >     #2  0x000055555558e3cd in tcp_chr_disconnect (chr=0x55555582ee90) at chardev/char-socket.c:497
> >     #3  0x000055555558ea32 in tcp_chr_new_client (chr=chr@entry=0x55555582ee90, sioc=sioc@entry=0x55555582f0b0) at chardev/char-socket.c:892
> >     #4  0x000055555558eeb8 in qemu_chr_socket_connected (task=0x55555582f300, opaque=<optimized out>) at chardev/char-socket.c:1090
> >     #5  0x0000555555574352 in qio_task_complete (task=task@entry=0x55555582f300) at io/task.c:196
> >     #6  0x00005555555745f4 in qio_task_thread_result (opaque=0x55555582f300) at io/task.c:111
> >     #7  qio_task_wait_thread (task=0x55555582f300) at io/task.c:190
> >     #8  0x000055555558f17e in tcp_chr_wait_connected (chr=0x55555582ee90, errp=0x555555802a08 <error_abort>) at chardev/char-socket.c:1013
> >     #9  0x0000555555567cbd in char_socket_client_reconnect_test (opaque=0x5555557fe020 <client8unix>) at tests/test-char.c:1152
> > The second call:
> >     #0  0x00007ffff5ac3277 in raise () from /lib64/libc.so.6
> >     #1  0x00007ffff5ac4968 in abort () from /lib64/libc.so.6
> >     #2  0x00007ffff5abc096 in __assert_fail_base () from /lib64/libc.so.6
> >     #3  0x00007ffff5abc142 in __assert_fail () from /lib64/libc.so.6
> >     #4  0x000055555558d10a in qemu_chr_socket_restart_timer (chr=0x55555582ee90) at chardev/char-socket.c:125
> >     #5  0x000055555558df0c in tcp_chr_disconnect_locked (chr=<optimized out>) at chardev/char-socket.c:490
> >     #6  0x000055555558df4d in tcp_chr_disconnect (chr=0x55555582ee90) at chardev/char-socket.c:497
> >     #7  0x000055555558e5b2 in tcp_chr_new_client (chr=chr@entry=0x55555582ee90, sioc=sioc@entry=0x55555582f0b0) at chardev/char-socket.c:892
> >     #8  0x000055555558e93a in tcp_chr_connect_client_sync (chr=chr@entry=0x55555582ee90, errp=errp@entry=0x7fffffffd178) at chardev/char-socket.c:944
> >     #9  0x000055555558ec78 in tcp_chr_wait_connected (chr=0x55555582ee90, errp=0x555555802a08 <error_abort>) at chardev/char-socket.c:1035
> >     #10 0x000055555556804b in char_socket_client_test (opaque=0x5555557fe020 <client8unix>) at tests/test-char.c:1023
> >
> > Run test/test-char to reproduce this issue.
> >
> > test-char: chardev/char-socket.c:125: qemu_chr_socket_restart_timer: Assertion `!s->reconnect_timer' failed.
> >
> > Signed-off-by: Li Feng <fengli@smartx.com>
> > ---
> > v2:
> > - Rewrite the solution.
> > - Add test to reproduce this issue.
> >
> >  chardev/char-socket.c |  2 +-
> >  tests/test-char.c     | 48 ++++++++++++++++++++++++++++++++++++++----------
> >  2 files changed, 39 insertions(+), 11 deletions(-)
> >
> > diff --git a/chardev/char-socket.c b/chardev/char-socket.c
> > index 1f14c2c7c8..d84330b3c9 100644
> > --- a/chardev/char-socket.c
> > +++ b/chardev/char-socket.c
> > @@ -486,7 +486,7 @@ static void tcp_chr_disconnect_locked(Chardev *chr)
> >      if (emit_close) {
> >          qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
> >      }
> > -    if (s->reconnect_time) {
> > +    if (s->reconnect_time && !s->reconnect_timer) {
> >          qemu_chr_socket_restart_timer(chr);
> >      }
> >  }
> > diff --git a/tests/test-char.c b/tests/test-char.c
> > index 8d39bdc9fa..13dbbfe2a3 100644
> > --- a/tests/test-char.c
> > +++ b/tests/test-char.c
> > @@ -625,12 +625,14 @@ static void char_udp_test(void)
> >  typedef struct {
> >      int event;
> >      bool got_pong;
> > +    CharBackend *be;
> >  } CharSocketTestData;
> >
> >
> >  #define SOCKET_PING "Hello"
> >  #define SOCKET_PONG "World"
> >
> > +typedef void (*char_socket_cb)(void *opaque, QEMUChrEvent event);
> >
> >  static void
> >  char_socket_event(void *opaque, QEMUChrEvent event)
> > @@ -639,6 +641,23 @@ char_socket_event(void *opaque, QEMUChrEvent event)
> >      data->event = event;
> >  }
> >
> > +static void
> > +char_socket_event_with_error(void *opaque, QEMUChrEvent event)
> > +{
> > +    CharSocketTestData *data = opaque;
> > +    CharBackend *be = data->be;
> > +    data->event = event;
> > +    switch (event) {
> > +    case CHR_EVENT_OPENED:
> > +        qemu_chr_fe_disconnect(be);
> > +        return;
> > +    case CHR_EVENT_CLOSED:
> > +        return;
> > +    default:
> > +        return;
> > +    }
> > +}
> > +
> >
> >  static void
> >  char_socket_read(void *opaque, const uint8_t *buf, int size)
> > @@ -783,6 +802,7 @@ static void char_socket_server_test(gconstpointer opaque)
> >
> >   reconnect:
> >      data.event = -1;
> > +    data.be = &be;
> >      qemu_chr_fe_set_handlers(&be, NULL, NULL,
> >                               char_socket_event, NULL,
> >                               &data, NULL, true);
> > @@ -869,6 +889,7 @@ typedef struct {
> >      const char *reconnect;
> >      bool wait_connected;
> >      bool fd_pass;
> > +    char_socket_cb event_cb;
> >  } CharSocketClientTestConfig;
> >
> >  static void char_socket_client_dupid_test(gconstpointer opaque)
> > @@ -920,6 +941,7 @@ static void char_socket_client_dupid_test(gconstpointer opaque)
> >  static void char_socket_client_test(gconstpointer opaque)
> >  {
> >      const CharSocketClientTestConfig *config = opaque;
> > +    const char_socket_cb event_cb = config->event_cb;
> >      QIOChannelSocket *ioc;
> >      char *optstr;
> >      Chardev *chr;
> > @@ -983,8 +1005,9 @@ static void char_socket_client_test(gconstpointer opaque)
> >
> >   reconnect:
> >      data.event = -1;
> > +    data.be = &be;
> >      qemu_chr_fe_set_handlers(&be, NULL, NULL,
> > -                             char_socket_event, NULL,
> > +                             event_cb, NULL,
> >                               &data, NULL, true);
> >      if (config->reconnect) {
> >          g_assert(data.event == -1);
> > @@ -1022,7 +1045,7 @@ static void char_socket_client_test(gconstpointer opaque)
> >      /* Setup a callback to receive the reply to our greeting */
> >      qemu_chr_fe_set_handlers(&be, char_socket_can_read,
> >                               char_socket_read,
> > -                             char_socket_event, NULL,
> > +                             event_cb, NULL,
> >                               &data, NULL, true);
> >      g_assert(data.event == CHR_EVENT_OPENED);
> >      data.event = -1;
> > @@ -1467,19 +1490,22 @@ int main(int argc, char **argv)
> >
> >  #define SOCKET_CLIENT_TEST(name, addr)                                  \
> >      static CharSocketClientTestConfig client1 ## name =                 \
> > -        { addr, NULL, false, false };                                   \
> > +        { addr, NULL, false, false, char_socket_event};                 \
> >      static CharSocketClientTestConfig client2 ## name =                 \
> > -        { addr, NULL, true, false };                                    \
> > +        { addr, NULL, true, false, char_socket_event };                 \
> >      static CharSocketClientTestConfig client3 ## name =                 \
> > -        { addr, ",reconnect=1", false };                                \
> > +        { addr, ",reconnect=1", false, false, char_socket_event };      \
> >      static CharSocketClientTestConfig client4 ## name =                 \
> > -        { addr, ",reconnect=1", true };                                 \
> > +        { addr, ",reconnect=1", true, false, char_socket_event };       \
> >      static CharSocketClientTestConfig client5 ## name =                 \
> > -        { addr, NULL, false, true };                                    \
> > +        { addr, NULL, false, true, char_socket_event };                 \
> >      static CharSocketClientTestConfig client6 ## name =                 \
> > -        { addr, NULL, true, true };                                     \
> > +        { addr, NULL, true, true, char_socket_event };                  \
> >      static CharSocketClientTestConfig client7 ## name =                 \
> > -        { addr, ",reconnect=1", false, false };                         \
> > +        { addr, ",reconnect=1", false, false, char_socket_event };      \
> > +    static CharSocketClientTestConfig client8 ## name =                 \
> > +        { addr, ",reconnect=1", true, false,                            \
> > +            char_socket_event_with_error };                             \
> >      g_test_add_data_func("/char/socket/client/mainloop/" # name,        \
> >                           &client1 ##name, char_socket_client_test);     \
> >      g_test_add_data_func("/char/socket/client/wait-conn/" # name,       \
> > @@ -1493,7 +1519,9 @@ int main(int argc, char **argv)
> >      g_test_add_data_func("/char/socket/client/wait-conn-fdpass/" # name, \
> >                           &client6 ##name, char_socket_client_test);     \
> >      g_test_add_data_func("/char/socket/client/dupid-reconnect/" # name, \
> > -                         &client7 ##name, char_socket_client_dupid_test)
> > +                         &client7 ##name, char_socket_client_dupid_test);\
> > +    g_test_add_data_func("/char/socket/client/reconnect-error/" # name, \
> > +                         &client8 ##name, char_socket_client_test)
> >
> >      if (has_ipv4) {
> >          SOCKET_SERVER_TEST(tcp, &tcpaddr);
> > --
> > 2.11.0
> >
>