Commit d0d6ff58 authored by Daniel P. Berrangé's avatar Daniel P. Berrangé Committed by Paolo Bonzini
Browse files

nbd: convert qemu-nbd server to use I/O channels for connection setup 



This converts the qemu-nbd server to use the QIOChannelSocket
class for initial listener socket setup and accepting of client
connections. Actual I/O is still being performed against the
socket file descriptor using the POSIX socket APIs.

Signed-off-by: default avatarDaniel P. Berrange <berrange@redhat.com>
Message-Id: <1455129674-17255-5-git-send-email-berrange@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 064097d9

qemu-nbd.c

+53 −38
Original line number Diff line number Diff line
@@ -22,19 +22,17 @@ 
#include "block/block_int.h"

#include "block/nbd.h"

#include "qemu/main-loop.h"

#include "qemu/sockets.h"

#include "qemu/error-report.h"

#include "qemu/config-file.h"

#include "block/snapshot.h"

#include "qapi/util.h"

#include "qapi/qmp/qstring.h"

#include "qom/object_interfaces.h"

#include "io/channel-socket.h"



#include <getopt.h>

#include <sys/socket.h>

#include <netinet/in.h>

#include <netinet/tcp.h>

#include <arpa/inet.h>

#include <sys/types.h>

#include <signal.h>

#include <libgen.h>

#include <pthread.h>
@@ -53,7 +51,8 @@ static int persistent = 0; 
static enum { RUNNING, TERMINATE, TERMINATING, TERMINATED } state;

static int shared = 1;

static int nb_fds;

static int server_fd;

static QIOChannelSocket *server_ioc;

static int server_watch = -1;



static void usage(const char *name)

{
@@ -236,19 +235,21 @@ static void *nbd_client_thread(void *arg) 
    char *device = arg;

    off_t size;

    uint32_t nbdflags;

    int fd, sock;

    QIOChannelSocket *sioc;

    int fd;

    int ret;

    pthread_t show_parts_thread;

    Error *local_error = NULL;





    sock = socket_connect(saddr, &local_error, NULL, NULL);

    if (sock < 0) {

    sioc = qio_channel_socket_new();

    if (qio_channel_socket_connect_sync(sioc,

                                        saddr,

                                        &local_error) < 0) {

        error_report_err(local_error);

        goto out;

    }



    ret = nbd_receive_negotiate(sock, NULL, &nbdflags,

    ret = nbd_receive_negotiate(sioc->fd, NULL, &nbdflags,

                                &size, &local_error);

    if (ret < 0) {

        if (local_error) {
@@ -264,7 +265,7 @@ static void *nbd_client_thread(void *arg) 
        goto out_socket;

    }



    ret = nbd_init(fd, sock, nbdflags, size);

    ret = nbd_init(fd, sioc->fd, nbdflags, size);

    if (ret < 0) {

        goto out_fd;

    }
@@ -285,13 +286,14 @@ static void *nbd_client_thread(void *arg) 
        goto out_fd;

    }

    close(fd);

    object_unref(OBJECT(sioc));

    kill(getpid(), SIGTERM);

    return (void *) EXIT_SUCCESS;



out_fd:

    close(fd);

out_socket:

    closesocket(sock);

    object_unref(OBJECT(sioc));

out:

    kill(getpid(), SIGTERM);

    return (void *) EXIT_FAILURE;
@@ -308,7 +310,7 @@ static void nbd_export_closed(NBDExport *exp) 
    state = TERMINATED;

}



static void nbd_update_server_fd_handler(int fd);

static void nbd_update_server_watch(void);



static void nbd_client_closed(NBDClient *client)

{
@@ -316,37 +318,51 @@ static void nbd_client_closed(NBDClient *client) 
    if (nb_fds == 0 && !persistent && state == RUNNING) {

        state = TERMINATE;

    }

    nbd_update_server_fd_handler(server_fd);

    nbd_update_server_watch();

    nbd_client_put(client);

}



static void nbd_accept(void *opaque)

static gboolean nbd_accept(QIOChannel *ioc, GIOCondition cond, gpointer opaque)

{

    struct sockaddr_in addr;

    socklen_t addr_len = sizeof(addr);

    QIOChannelSocket *cioc;

    int fd;



    int fd = accept(server_fd, (struct sockaddr *)&addr, &addr_len);

    if (fd < 0) {

        perror("accept");

        return;

    cioc = qio_channel_socket_accept(QIO_CHANNEL_SOCKET(ioc),

                                     NULL);

    if (!cioc) {

        return TRUE;

    }



    if (state >= TERMINATE) {

        close(fd);

        return;

        object_unref(OBJECT(cioc));

        return TRUE;

    }



    nb_fds++;

    nbd_update_server_fd_handler(server_fd);

    nbd_update_server_watch();

    fd = dup(cioc->fd);

    if (fd >= 0) {

        nbd_client_new(exp, fd, nbd_client_closed);

    }

    object_unref(OBJECT(cioc));



    return TRUE;

}



static void nbd_update_server_fd_handler(int fd)

static void nbd_update_server_watch(void)

{

    if (nbd_can_accept()) {

        qemu_set_fd_handler(fd, nbd_accept, NULL, (void *)(uintptr_t)fd);

        if (server_watch == -1) {

            server_watch = qio_channel_add_watch(QIO_CHANNEL(server_ioc),

                                                 G_IO_IN,

                                                 nbd_accept,

                                                 NULL, NULL);

        }

    } else {

        qemu_set_fd_handler(fd, NULL, NULL, NULL);

        if (server_watch != -1) {

            g_source_remove(server_watch);

            server_watch = -1;

        }

    }

}
@@ -433,7 +449,6 @@ int main(int argc, char **argv) 
    int flags = BDRV_O_RDWR;

    int partition = -1;

    int ret = 0;

    int fd;

    bool seen_cache = false;

    bool seen_discard = false;

    bool seen_aio = false;
@@ -632,15 +647,15 @@ int main(int argc, char **argv) 
    }



    if (disconnect) {

        fd = open(argv[optind], O_RDWR);

        if (fd < 0) {

        int nbdfd = open(argv[optind], O_RDWR);

        if (nbdfd < 0) {

            error_report("Cannot open %s: %s", argv[optind],

                         strerror(errno));

            exit(EXIT_FAILURE);

        }

        nbd_disconnect(fd);

        nbd_disconnect(nbdfd);



        close(fd);

        close(nbdfd);



        printf("%s disconnected\n", argv[optind]);
@@ -773,8 +788,9 @@ int main(int argc, char **argv) 
        exit(EXIT_FAILURE);

    }



    fd = socket_listen(saddr, &local_err);

    if (fd < 0) {

    server_ioc = qio_channel_socket_new();

    if (qio_channel_socket_listen_sync(server_ioc, saddr, &local_err) < 0) {

        object_unref(OBJECT(server_ioc));

        error_report_err(local_err);

        return 1;

    }
@@ -792,8 +808,7 @@ int main(int argc, char **argv) 
        memset(&client_thread, 0, sizeof(client_thread));

    }



    server_fd = fd;

    nbd_update_server_fd_handler(fd);

    nbd_update_server_watch();



    /* now when the initialization is (almost) complete, chdir("/")

     * to free any busy filesystems */