bytemark/flexnbd-c
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Rewrote error & log functions to be more general, use longjmp to get out of

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trouble and into predictable cleanup functions (one for each of serve,
client & control contexts).  We use 'fatal' to mean 'kill the thread' and
'error' to mean 'don't kill the thread', assuming some recovery action,
except I don't use error anywhere yet.
This commit is contained in:
Matthew Bloch
2012-06-09 02:25:12 +01:00
parent 8691533d88
commit b546539ab8
12 changed files with 259 additions and 174 deletions
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68
src/serve.c
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@@ -46,7 +46,7 @@ int server_lock_io( struct server * serve)
{
NULLCHECK( serve );
SERVER_ERROR_ON_FAILURE(
FATAL_IF_NEGATIVE(
pthread_mutex_lock(&serve->l_io),
"Problem with I/O lock"
);
@@ -59,7 +59,7 @@ void server_unlock_io( struct server* serve )
{
NULLCHECK( serve );
SERVER_ERROR_ON_FAILURE(
FATAL_IF_NEGATIVE(
pthread_mutex_unlock(&serve->l_io),
"Problem with I/O unlock"
);
@@ -75,26 +75,26 @@ void serve_open_server_socket(struct server* params)
params->server_fd= socket(params->bind_to.generic.sa_family == AF_INET ?
PF_INET : PF_INET6, SOCK_STREAM, 0);
SERVER_ERROR_ON_FAILURE(params->server_fd,
FATAL_IF_NEGATIVE(params->server_fd,
"Couldn't create server socket");
SERVER_ERROR_ON_FAILURE(
FATAL_IF_NEGATIVE(
setsockopt(params->server_fd, SOL_SOCKET, SO_REUSEADDR, &optval, sizeof(optval)),
"Couldn't set SO_REUSEADDR"
);
SERVER_ERROR_ON_FAILURE(
FATAL_IF_NEGATIVE(
setsockopt(params->server_fd, IPPROTO_TCP, TCP_NODELAY, &optval, sizeof(optval)),
"Couldn't set TCP_NODELAY"
);
SERVER_ERROR_ON_FAILURE(
FATAL_IF_NEGATIVE(
bind(params->server_fd, &params->bind_to.generic,
sizeof(params->bind_to)),
"Couldn't bind server to IP address"
);
SERVER_ERROR_ON_FAILURE(
FATAL_IF_NEGATIVE(
listen(params->server_fd, params->tcp_backlog),
"Couldn't listen on server socket"
);
@@ -121,7 +121,7 @@ int tryjoin_client_thread( struct client_tbl_entry *entry, int (*joinfunc)(pthre
if (joinfunc(entry->thread, &status) != 0) {
if (errno != EBUSY)
SERVER_ERROR_ON_FAILURE(-1, "Problem with joining thread");
FATAL_IF_NEGATIVE(-1, "Problem with joining thread");
}
else {
debug("nbd thread %p exited (%s) with status %ld",
@@ -187,8 +187,6 @@ int cleanup_and_find_client_slot(struct server* params)
break;
}
}
if ( -1 == slot ) { debug( "No client slot found." ); }
return slot;
}
@@ -230,7 +228,7 @@ int server_should_accept_client(
debug( "Rejecting client %s: Access control error", s_client_address );
debug( "We %s have an acl, and default_deny is %s",
(params->acl ? "do" : "do not"),
(params->default_deny ? "true" : "false") );
(params->acl->default_deny ? "true" : "false") );
write(client_fd, "Access control error", 20);
return 0;
}
@@ -263,6 +261,7 @@ void accept_nbd_client(
slot = cleanup_and_find_client_slot(params);
if (slot < 0) {
warn("too many clients to accept connection");
write(client_fd, "Too many clients", 16);
close(client_fd);
return;
@@ -297,6 +296,8 @@ int server_is_closed(struct server* serve)
void server_close_clients( struct server *params )
{
NULLCHECK(params);
info("closing all clients");
int i, j;
struct client_tbl_entry *entry;
@@ -318,6 +319,7 @@ void server_close_clients( struct server *params )
void serve_accept_loop(struct server* params)
{
NULLCHECK( params );
info("accept loop starting");
while (1) {
int activity_fd, client_fd;
union mysockaddr client_address;
@@ -330,7 +332,7 @@ void serve_accept_loop(struct server* params)
if (params->control_socket_name)
FD_SET(params->control_fd, &fds);
SERVER_ERROR_ON_FAILURE(select(FD_SETSIZE, &fds,
FATAL_IF_NEGATIVE(select(FD_SETSIZE, &fds,
NULL, NULL, NULL), "select() failed");
if ( self_pipe_fd_isset( params->close_signal, &fds ) ){
@@ -343,11 +345,11 @@ void serve_accept_loop(struct server* params)
client_fd = accept(activity_fd, &client_address.generic, &socklen);
if (activity_fd == params->server_fd) {
debug("Accepted nbd client socket");
info("Accepted nbd client socket");
accept_nbd_client(params, client_fd, &client_address);
}
if (activity_fd == params->control_fd) {
debug("Accepted control client socket");
info("Accepted control client socket");
accept_control_connection(params, client_fd, &client_address);
}
@@ -364,10 +366,10 @@ void serve_init_allocation_map(struct server* params)
int fd = open(params->filename, O_RDONLY);
off64_t size;
SERVER_ERROR_ON_FAILURE(fd, "Couldn't open %s", params->filename);
FATAL_IF_NEGATIVE(fd, "Couldn't open %s", params->filename);
size = lseek64(fd, 0, SEEK_END);
params->size = size;
SERVER_ERROR_ON_FAILURE(size, "Couldn't find size of %s",
FATAL_IF_NEGATIVE(size, "Couldn't find size of %s",
params->filename);
params->allocation_map =
build_allocation_map(fd, size, block_allocation_resolution);
@@ -379,34 +381,43 @@ void serve_init_allocation_map(struct server* params)
void serve_signal_close( struct server * serve )
{
NULLCHECK( serve );
info("signalling close");
self_pipe_signal( serve->close_signal );
}
/** Closes sockets, frees memory and waits for all client threads to finish */
void serve_cleanup(struct server* params)
void serve_cleanup(struct server* params, int fatal)
{
NULLCHECK( params );
info("cleaning up");
int i;
close(params->server_fd);
close(params->control_fd);
if (params->server_fd)
close(params->server_fd);
if (params->control_fd)
close(params->control_fd);
if (params->acl)
free(params->acl);
//free(params->filename);
if (params->control_socket_name)
//free(params->control_socket_name);
;
pthread_mutex_destroy(&params->l_io);
if (params->proxy_fd);
close(params->proxy_fd);
self_pipe_destroy( params->close_signal );
if (params->close_signal)
self_pipe_destroy( params->close_signal );
free(params->allocation_map);
if (params->allocation_map)
free(params->allocation_map);
if (params->mirror)
debug("mirror thread running! this should not happen!");
if (params->mirror) {
pthread_t mirror_t = params->mirror->thread;
params->mirror->signal_abandon = 1;
pthread_join(mirror_t, NULL);
}
for (i=0; i < MAX_NBD_CLIENTS; i++) {
void* status;
@@ -422,18 +433,19 @@ void serve_cleanup(struct server* params)
void do_serve(struct server* params)
{
NULLCHECK( params );
error_set_handler((cleanup_handler*) serve_cleanup, params);
pthread_mutex_init(&params->l_io, NULL);
params->close_signal = self_pipe_create();
if ( NULL == params->close_signal) {
SERVER_ERROR( "close signal creation failed" );
fatal( "close signal creation failed" );
}
serve_open_server_socket(params);
serve_open_control_socket(params);
serve_init_allocation_map(params);
serve_accept_loop(params);
serve_cleanup(params);
serve_cleanup(params, 0);
}