Using a single main loop for sockets will help yielding from the socket coroutine back to the main loop, and later reentering it.
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> --- qemu-nbd.c | 101 ++++++++++++++++++++++++++++-------------------------------- 1 files changed, 47 insertions(+), 54 deletions(-) diff --git a/qemu-nbd.c b/qemu-nbd.c index 9fa3979..7896e9b 100644 --- a/qemu-nbd.c +++ b/qemu-nbd.c @@ -36,6 +36,8 @@ static NBDExport *exp; static int verbose; +static int shared = 1; +static int nb_fds; static void usage(const char *name) { @@ -179,6 +181,35 @@ static void show_parts(const char *device) } } +static int nbd_can_accept(void *opaque) +{ + return nb_fds < shared; +} + +static void nbd_read(void *opaque) +{ + int fd = (uintptr_t) opaque; + + if (nbd_trip(&exp, fd) != 0) { + qemu_set_fd_handler2(fd, NULL, NULL, NULL, NULL); + close(fd); + nb_fds--; + } +} + +static void nbd_accept(void *opaque) +{ + int server_fd = (uintptr_t) opaque; + struct sockaddr_in addr; + socklen_t addr_len = sizeof(addr); + + int fd = accept(server_fd, (struct sockaddr *)&addr, &addr_len); + if (fd != -1 && nbd_negotiate(fd, exp.size, exp.nbdflags) != -1) { + qemu_set_fd_handler2(fd, NULL, nbd_read, NULL, (void *) (intptr_t) fd); + nb_fds++; + } +} + int main(int argc, char **argv) { BlockDriverState *bs; @@ -187,8 +218,6 @@ int main(int argc, char **argv) bool disconnect = false; const char *bindto = "0.0.0.0"; int port = NBD_DEFAULT_PORT; - struct sockaddr_in addr; - socklen_t addr_len = sizeof(addr); off_t fd_size = -1; char *device = NULL; char *socket = NULL; @@ -219,13 +248,8 @@ int main(int argc, char **argv) int flags = BDRV_O_RDWR; int partition = -1; int ret; - int shared = 1; fd_set fds; - int *sharing_fds; int fd; - int i; - int nb_fds = 0; - int max_fd; int persistent = 0; while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) { @@ -427,61 +451,30 @@ int main(int argc, char **argv) /* children */ } - sharing_fds = g_malloc((shared + 1) * sizeof(int)); - if (socket) { - sharing_fds[0] = unix_socket_incoming(socket); + fd = unix_socket_incoming(socket); } else { - sharing_fds[0] = tcp_socket_incoming(bindto, port); + fd = tcp_socket_incoming(bindto, port); } - if (sharing_fds[0] == -1) + if (fd == -1) { return 1; - max_fd = sharing_fds[0]; - nb_fds++; - - do { - - FD_ZERO(&fds); - for (i = 0; i < nb_fds; i++) - FD_SET(sharing_fds[i], &fds); - - ret = select(max_fd + 1, &fds, NULL, NULL, NULL); - if (ret == -1) - break; + } - if (FD_ISSET(sharing_fds[0], &fds)) - ret--; - for (i = 1; i < nb_fds && ret; i++) { - if (FD_ISSET(sharing_fds[i], &fds)) { - if (nbd_trip(exp, sharing_fds[i]) != 0) { - close(sharing_fds[i]); - nb_fds--; - sharing_fds[i] = sharing_fds[nb_fds]; - i--; - } - ret--; - } - } - /* new connection ? */ - if (FD_ISSET(sharing_fds[0], &fds)) { - if (nb_fds < shared + 1) { - sharing_fds[nb_fds] = accept(sharing_fds[0], - (struct sockaddr *)&addr, - &addr_len); - if (sharing_fds[nb_fds] != -1 && - nbd_negotiate(sharing_fds[nb_fds], fd_size, nbdflags) != -1) { - if (sharing_fds[nb_fds] > max_fd) - max_fd = sharing_fds[nb_fds]; - nb_fds++; - } - } - } - } while (persistent || nb_fds > 1); + qemu_set_fd_handler2(fd, nbd_can_accept, nbd_accept, NULL, + (void *)(uintptr_t)fd); + + /* Wait for the first incoming connection. */ + FD_ZERO(&fds); + FD_SET(fd, &fds); + ret = select(fd + 1, &fds, NULL, NULL, NULL); + if (ret != -1) { + do { + main_loop_wait(false); + } while (persistent || nb_fds > 0); + } - close(sharing_fds[0]); nbd_export_close(exp); - g_free(sharing_fds); if (socket) unlink(socket); -- 1.7.6