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Retry failed rebind attempts

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When we receive a migration, if rebinding to the new listen address and
port fails for a reason which might be fixable, rather than killing the
server we retry once a second.  Also in this patch: non-overlapping log
messages and a fix for the client going away halfway through a sendfile
loop.
This commit is contained in:
Alex Young
2012-07-12 14:14:46 +01:00
parent 9002341e77
commit 10b46beeea
12 changed files with 194 additions and 20 deletions
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77
src/serve.c
View File

@@ -192,6 +192,62 @@ int server_port( struct server * server )
}
/* Try to bind to our serving socket, retrying until it works or gives a
* fatal error. */
void serve_bind( struct server * serve )
{
int bind_result;
char s_address[64];
memset( s_address, 0, 64 );
strcpy( s_address, "???" );
inet_ntop( serve->bind_to.generic.sa_family,
sockaddr_address_data( &serve->bind_to.generic),
s_address, 64 );
do {
bind_result = bind(
serve->server_fd,
&serve->bind_to.generic,
sizeof(serve->bind_to));
if ( 0 == bind_result ) {
info( "Bound to %s port %d",
s_address,
ntohs(serve->bind_to.v4.sin_port));
break;
}
else {
warn( "Couldn't bind to %s port %d: %s",
s_address,
ntohs(serve->bind_to.v4.sin_port),
strerror( errno ) );
switch (errno){
/* bind() can give us EACCES,
* EADDRINUSE, EADDRNOTAVAIL, EBADF,
* EINVAL or ENOTSOCK.
*
* Any of these other than EACCES,
* EADDRINUSE or EADDRNOTAVAIL signify
* that there's a logic error somewhere.
*/
case EACCES:
case EADDRINUSE:
case EADDRNOTAVAIL:
debug("retrying");
sleep(1);
continue;
default:
fatal( "Giving up" );
}
}
} while ( 1 );
}
/** Prepares a listening socket for the NBD server, binding etc. */
void serve_open_server_socket(struct server* params)
{
@@ -205,21 +261,32 @@ void serve_open_server_socket(struct server* params)
FATAL_IF_NEGATIVE(params->server_fd,
"Couldn't create server socket");
/* We need SO_REUSEADDR so that when we switch from listening to
* serving we don't have to change address if we don't want to.
*
* If this fails, it's not necessarily bad in principle, but at
* this point in the code we can't tell if it's going to be a
* problem. It's also indicative of something odd going on, so
* we barf.
*/
FATAL_IF_NEGATIVE(
setsockopt(params->server_fd, SOL_SOCKET, SO_REUSEADDR, &optval, sizeof(optval)),
"Couldn't set SO_REUSEADDR"
);
/* TCP_NODELAY makes everything not be slow. If we can't set
* this, again, there's something odd going on which we don't
* understand.
*/
FATAL_IF_NEGATIVE(
setsockopt(params->server_fd, IPPROTO_TCP, TCP_NODELAY, &optval, sizeof(optval)),
"Couldn't set TCP_NODELAY"
);
FATAL_IF_NEGATIVE(
bind(params->server_fd, &params->bind_to.generic,
sizeof(params->bind_to)),
"Couldn't bind server to IP address"
);
/* If we can't bind, presumably that's because someone else is
* squatting on our ip/port combo, or the ip isn't yet
* configured. Ideally we want to retry this. */
serve_bind(params);
FATAL_IF_NEGATIVE(
listen(params->server_fd, params->tcp_backlog),