Rsync crash

[Matt McCutchen]

On Mon, 2009-01-12 at 13:29 +0100, Maxence DUNNEWIND wrote:
> Anyway, after it has been working well for some time (between 2 and
> 24hours), the rsync daemon crashes.

I wouldn't call an infinite loop a crash, but whatever.

> It is still running but seems to
> retry something infinitly.
> 
> The rsync log doesn't outputs anything before the crash (just the log of
> mirrors sync). I 'straced' the rsync process and have the following
> outputs :
> 
> select(6, [4 5], NULL, NULL, NULL)      = 1 (in [5])
> accept(5, {sa_family=AF_INET, sin_port=htons(37870), sin_addr=inet_addr("xxxxxxxxxxxx")}, [16]) = 3
> rt_sigaction(SIGCHLD, {0x80768c0, [], SA_NOCLDSTOP}, NULL, 8) = 0
> clone(child_stack=0, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0xb7e196f8) = 7117
> close(3)                                = 0
> select(6, [4 5], NULL, NULL, NULL)      = 1 (in [4])
> accept(4, {sa_family=AF_INET6, sin6_port=htons(55783), inet_pton(AF_INET6, "xxxxxxxxxxxxxxx", &sin6_addr), sin6_flowinfo=0, sin6_scope_id=0}, [28]) = 3
> rt_sigaction(SIGCHLD, {0x80768c0, [], SA_NOCLDSTOP}, NULL, 8) = 0
> clone(child_stack=0, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0xb7e196f8) = 7123
> close(3)                                = 0
> select(6, [4 5], NULL, NULL, NULL)      = 2 (in [4 5])
> select(6, [4 5], NULL, NULL, NULL)      = 2 (in [4 5])
> select(6, [4 5], NULL, NULL, NULL)      = 2 (in [4 5])
> 
> The last lines (select() call) is then repeated infinitly and the rsync
> daemon is no more usuable (until i restart it).

I see what happened here: incoming connections arrived on two different
sockets at the same time, and the select call wasn't prepared to handle
that case.  I'll submit a patch.

-- 
Matt