image-fuzzer: Public API for image-fuzzer/runner/runner.py

[qemu.git] / qemu-nbd.c

diff --git a/qemu-nbd.c b/qemu-nbd.c
index b330d8d10b2fe62687cd0fad553302c823804b6b..626e5844f9bd167dda5a8f46722c1c4c8b0572de 100644 (file)
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -17,8 +17,12 @@
  */
 
 #include "qemu-common.h"
  */
 
 #include "qemu-common.h"

-#include "block_int.h"
-#include "nbd.h"
+#include "block/block.h"
+#include "block/nbd.h"
+#include "qemu/main-loop.h"
+#include "qemu/sockets.h"
+#include "qemu/error-report.h"
+#include "block/snapshot.h"

 
 #include <stdarg.h>
 #include <stdio.h>
 
 #include <stdarg.h>
 #include <stdio.h>


@@ -33,40 +37,67 @@
 #include <libgen.h>
 #include <pthread.h>
 
 #include <libgen.h>
 #include <pthread.h>
 

-#define SOCKET_PATH    "/var/lock/qemu-nbd-%s"
+#define SOCKET_PATH          "/var/lock/qemu-nbd-%s"
+#define QEMU_NBD_OPT_CACHE   1
+#define QEMU_NBD_OPT_AIO     2
+#define QEMU_NBD_OPT_DISCARD 3

 
 

-#define NBD_BUFFER_SIZE (1024*1024)
-
-static int sigterm_wfd;
+static NBDExport *exp;

 static int verbose;
 static int verbose;

-static char *device;

 static char *srcpath;
 static char *sockpath;
 static char *srcpath;
 static char *sockpath;

+static int persistent = 0;
+static enum { RUNNING, TERMINATE, TERMINATING, TERMINATED } state;
+static int shared = 1;
+static int nb_fds;

 
 static void usage(const char *name)
 {
 
 static void usage(const char *name)
 {

-    printf(
+    (printf) (

 "Usage: %s [OPTIONS] FILE\n"
 "QEMU Disk Network Block Device Server\n"
 "\n"
 "Usage: %s [OPTIONS] FILE\n"
 "QEMU Disk Network Block Device Server\n"
 "\n"

+"  -h, --help           display this help and exit\n"
+"  -V, --version        output version information and exit\n"
+"\n"
+"Connection properties:\n"

 "  -p, --port=PORT      port to listen on (default `%d')\n"
 "  -p, --port=PORT      port to listen on (default `%d')\n"

-"  -o, --offset=OFFSET  offset into the image\n"

 "  -b, --bind=IFACE     interface to bind to (default `0.0.0.0')\n"
 "  -k, --socket=PATH    path to the unix socket\n"
 "                       (default '"SOCKET_PATH"')\n"
 "  -b, --bind=IFACE     interface to bind to (default `0.0.0.0')\n"
 "  -k, --socket=PATH    path to the unix socket\n"
 "                       (default '"SOCKET_PATH"')\n"

-"  -r, --read-only      export read-only\n"
-"  -P, --partition=NUM  only expose partition NUM\n"
-"  -s, --snapshot       use snapshot file\n"
-"  -n, --nocache        disable host cache\n"
-"  -c, --connect=DEV    connect FILE to the local NBD device DEV\n"
-"  -d, --disconnect     disconnect the specified device\n"

 "  -e, --shared=NUM     device can be shared by NUM clients (default '1')\n"
 "  -t, --persistent     don't exit on the last connection\n"
 "  -v, --verbose        display extra debugging information\n"
 "  -e, --shared=NUM     device can be shared by NUM clients (default '1')\n"
 "  -t, --persistent     don't exit on the last connection\n"
 "  -v, --verbose        display extra debugging information\n"

-"  -h, --help           display this help and exit\n"
-"  -V, --version        output version information and exit\n"

 "\n"
 "\n"

-"Report bugs to <[email protected]>\n"
+"Exposing part of the image:\n"
+"  -o, --offset=OFFSET  offset into the image\n"
+"  -P, --partition=NUM  only expose partition NUM\n"
+"\n"
+#ifdef __linux__
+"Kernel NBD client support:\n"
+"  -c, --connect=DEV    connect FILE to the local NBD device DEV\n"
+"  -d, --disconnect     disconnect the specified device\n"
+"\n"
+#endif
+"\n"
+"Block device options:\n"
+"  -f, --format=FORMAT  set image format (raw, qcow2, ...)\n"
+"  -r, --read-only      export read-only\n"
+"  -s, --snapshot       use FILE as an external snapshot, create a temporary\n"
+"                       file with backing_file=FILE, redirect the write to\n"
+"                       the temporary one\n"
+"  -l, --load-snapshot=SNAPSHOT_PARAM\n"
+"                       load an internal snapshot inside FILE and export it\n"
+"                       as an read-only device, SNAPSHOT_PARAM format is\n"
+"                       'snapshot.id=[ID],snapshot.name=[NAME]', or\n"
+"                       '[ID_OR_NAME]'\n"
+"  -n, --nocache        disable host cache\n"
+"      --cache=MODE     set cache mode (none, writeback, ...)\n"
+#ifdef CONFIG_LINUX_AIO
+"      --aio=MODE       set AIO mode (native or threads)\n"
+#endif
+"\n"
+"Report bugs to <[email protected]>\n"

     , name, NBD_DEFAULT_PORT, "DEVICE");
 }
 
     , name, NBD_DEFAULT_PORT, "DEVICE");
 }
 


@@ -125,8 +156,7 @@ static int find_partition(BlockDriverState *bs, int partition,
     }
 
     if (data[510] != 0x55 || data[511] != 0xaa) {
     }
 
     if (data[510] != 0x55 || data[511] != 0xaa) {

-        errno = -EINVAL;
-        return -1;
+        return -EINVAL;

     }
 
     for (i = 0; i < 4; i++) {
     }
 
     for (i = 0; i < 4; i++) {


@@ -164,20 +194,68 @@ static int find_partition(BlockDriverState *bs, int partition,
         }
     }
 
         }
     }
 

-    errno = -ENOENT;
-    return -1;
+    return -ENOENT;

 }
 
 static void termsig_handler(int signum)
 {
 }
 
 static void termsig_handler(int signum)
 {

-    static int sigterm_reported;
-    if (!sigterm_reported) {
-        sigterm_reported = (write(sigterm_wfd, "", 1) == 1);
+    state = TERMINATE;
+    qemu_notify_event();
+}
+
+static void combine_addr(char *buf, size_t len, const char* address,
+                         uint16_t port)
+{
+    /* If the address-part contains a colon, it's an IPv6 IP so needs [] */
+    if (strstr(address, ":")) {
+        snprintf(buf, len, "[%s]:%u", address, port);
+    } else {
+        snprintf(buf, len, "%s:%u", address, port);

     }
 }
 
     }
 }
 

+static int tcp_socket_incoming(const char *address, uint16_t port)
+{
+    char address_and_port[128];
+    Error *local_err = NULL;
+
+    combine_addr(address_and_port, 128, address, port);
+    int fd = inet_listen(address_and_port, NULL, 0, SOCK_STREAM, 0, &local_err);
+
+    if (local_err != NULL) {
+        error_report("%s", error_get_pretty(local_err));
+        error_free(local_err);
+    }
+    return fd;
+}
+
+static int unix_socket_incoming(const char *path)
+{
+    Error *local_err = NULL;
+    int fd = unix_listen(path, NULL, 0, &local_err);
+
+    if (local_err != NULL) {
+        error_report("%s", error_get_pretty(local_err));
+        error_free(local_err);
+    }
+    return fd;
+}
+
+static int unix_socket_outgoing(const char *path)
+{
+    Error *local_err = NULL;
+    int fd = unix_connect(path, &local_err);
+
+    if (local_err != NULL) {
+        error_report("%s", error_get_pretty(local_err));
+        error_free(local_err);
+    }
+    return fd;
+}
+

 static void *show_parts(void *arg)
 {
 static void *show_parts(void *arg)
 {

+    char *device = arg;

     int nbd;
 
     /* linux just needs an open() to trigger
     int nbd;
 
     /* linux just needs an open() to trigger


@@ -186,7 +264,7 @@ static void *show_parts(void *arg)
      *     modprobe nbd max_part=63
      */
     nbd = open(device, O_RDWR);
      *     modprobe nbd max_part=63
      */
     nbd = open(device, O_RDWR);

-    if (nbd != -1) {
+    if (nbd >= 0) {

         close(nbd);
     }
     return NULL;
         close(nbd);
     }
     return NULL;


@@ -194,37 +272,39 @@ static void *show_parts(void *arg)
 
 static void *nbd_client_thread(void *arg)
 {
 
 static void *nbd_client_thread(void *arg)
 {

-    int fd = *(int *)arg;
+    char *device = arg;

     off_t size;
     size_t blocksize;
     uint32_t nbdflags;
     off_t size;
     size_t blocksize;
     uint32_t nbdflags;

-    int sock;
+    int fd, sock;

     int ret;
     pthread_t show_parts_thread;
 
     int ret;
     pthread_t show_parts_thread;
 

-    do {
-        sock = unix_socket_outgoing(sockpath);
-        if (sock == -1) {
-            if (errno != ENOENT && errno != ECONNREFUSED) {
-                goto out;
-            }
-            sleep(1);  /* wait parent */
-        }
-    } while (sock == -1);
+    sock = unix_socket_outgoing(sockpath);
+    if (sock < 0) {
+        goto out;
+    }

 
     ret = nbd_receive_negotiate(sock, NULL, &nbdflags,
                                 &size, &blocksize);
 
     ret = nbd_receive_negotiate(sock, NULL, &nbdflags,
                                 &size, &blocksize);

-    if (ret == -1) {
-        goto out;
+    if (ret < 0) {
+        goto out_socket;
+    }
+
+    fd = open(device, O_RDWR);
+    if (fd < 0) {
+        /* Linux-only, we can use %m in printf.  */
+        fprintf(stderr, "Failed to open %s: %m\n", device);
+        goto out_socket;

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

-    if (ret == -1) {
-        goto out;
+    if (ret < 0) {
+        goto out_fd;

     }
 
     /* update partition table */
     }
 
     /* update partition table */

-    pthread_create(&show_parts_thread, NULL, show_parts, NULL);
+    pthread_create(&show_parts_thread, NULL, show_parts, device);

 
     if (verbose) {
         fprintf(stderr, "NBD device %s is now connected to %s\n",
 
     if (verbose) {
         fprintf(stderr, "NBD device %s is now connected to %s\n",


@@ -236,30 +316,81 @@ static void *nbd_client_thread(void *arg)
 
     ret = nbd_client(fd);
     if (ret) {
 
     ret = nbd_client(fd);
     if (ret) {

-        goto out;
+        goto out_fd;

     }
     close(fd);
     kill(getpid(), SIGTERM);
     return (void *) EXIT_SUCCESS;
 
     }
     close(fd);
     kill(getpid(), SIGTERM);
     return (void *) EXIT_SUCCESS;
 

+out_fd:
+    close(fd);
+out_socket:
+    closesocket(sock);

 out:
     kill(getpid(), SIGTERM);
     return (void *) EXIT_FAILURE;
 }
 
 out:
     kill(getpid(), SIGTERM);
     return (void *) EXIT_FAILURE;
 }
 

+static int nbd_can_accept(void *opaque)
+{
+    return nb_fds < shared;
+}
+
+static void nbd_export_closed(NBDExport *exp)
+{
+    assert(state == TERMINATING);
+    state = TERMINATED;
+}
+
+static void nbd_client_closed(NBDClient *client)
+{
+    nb_fds--;
+    if (nb_fds == 0 && !persistent && state == RUNNING) {
+        state = TERMINATE;
+    }
+    qemu_notify_event();
+    nbd_client_put(client);
+}
+
+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 < 0) {
+        perror("accept");
+        return;
+    }
+
+    if (state >= TERMINATE) {
+        close(fd);
+        return;
+    }
+
+    if (nbd_client_new(exp, fd, nbd_client_closed)) {
+        nb_fds++;
+    } else {
+        shutdown(fd, 2);
+        close(fd);
+    }
+}
+

 int main(int argc, char **argv)
 {
     BlockDriverState *bs;
 int main(int argc, char **argv)
 {
     BlockDriverState *bs;

+    BlockDriver *drv;

     off_t dev_offset = 0;
     off_t dev_offset = 0;

-    off_t offset = 0;

     uint32_t nbdflags = 0;
     bool disconnect = false;
     const char *bindto = "0.0.0.0";
     uint32_t nbdflags = 0;
     bool disconnect = false;
     const char *bindto = "0.0.0.0";

+    char *device = NULL;

     int port = NBD_DEFAULT_PORT;
     int port = NBD_DEFAULT_PORT;

-    struct sockaddr_in addr;
-    socklen_t addr_len = sizeof(addr);

     off_t fd_size;
     off_t fd_size;

-    const char *sopt = "hVb:o:p:rsnP:c:dvk:e:t";
+    QemuOpts *sn_opts = NULL;
+    const char *sn_id_or_name = NULL;
+    const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:tl:";

     struct option lopt[] = {
         { "help", 0, NULL, 'h' },
         { "version", 0, NULL, 'V' },
     struct option lopt[] = {
         { "help", 0, NULL, 'h' },
         { "version", 0, NULL, 'V' },


@@ -272,8 +403,15 @@ int main(int argc, char **argv)
         { "connect", 1, NULL, 'c' },
         { "disconnect", 0, NULL, 'd' },
         { "snapshot", 0, NULL, 's' },
         { "connect", 1, NULL, 'c' },
         { "disconnect", 0, NULL, 'd' },
         { "snapshot", 0, NULL, 's' },

+        { "load-snapshot", 1, NULL, 'l' },

         { "nocache", 0, NULL, 'n' },
         { "nocache", 0, NULL, 'n' },

+        { "cache", 1, NULL, QEMU_NBD_OPT_CACHE },
+#ifdef CONFIG_LINUX_AIO
+        { "aio", 1, NULL, QEMU_NBD_OPT_AIO },
+#endif
+        { "discard", 1, NULL, QEMU_NBD_OPT_DISCARD },

         { "shared", 1, NULL, 'e' },
         { "shared", 1, NULL, 'e' },

+        { "format", 1, NULL, 'f' },

         { "persistent", 0, NULL, 't' },
         { "verbose", 0, NULL, 'v' },
         { NULL, 0, NULL, 0 }
         { "persistent", 0, NULL, 't' },
         { "verbose", 0, NULL, 'v' },
         { NULL, 0, NULL, 0 }


@@ -285,30 +423,24 @@ int main(int argc, char **argv)
     int flags = BDRV_O_RDWR;
     int partition = -1;
     int ret;
     int flags = BDRV_O_RDWR;
     int partition = -1;
     int ret;

-    int shared = 1;
-    uint8_t *data;
-    fd_set fds;
-    int *sharing_fds;

     int fd;
     int fd;

-    int i;
-    int nb_fds = 0;
-    int max_fd;
-    int persistent = 0;
+    bool seen_cache = false;
+    bool seen_discard = false;
+#ifdef CONFIG_LINUX_AIO
+    bool seen_aio = false;
+#endif

     pthread_t client_thread;
     pthread_t client_thread;

+    const char *fmt = NULL;
+    Error *local_err = NULL;

 
     /* The client thread uses SIGTERM to interrupt the server.  A signal
      * handler ensures that "qemu-nbd -v -c" exits with a nice status code.
      */
     struct sigaction sa_sigterm;
 
     /* The client thread uses SIGTERM to interrupt the server.  A signal
      * handler ensures that "qemu-nbd -v -c" exits with a nice status code.
      */
     struct sigaction sa_sigterm;

-    int sigterm_fd[2];
-    if (qemu_pipe(sigterm_fd) == -1) {
-        err(EXIT_FAILURE, "Error setting up communication pipe");
-    }
-
-    sigterm_wfd = sigterm_fd[1];

     memset(&sa_sigterm, 0, sizeof(sa_sigterm));
     sa_sigterm.sa_handler = termsig_handler;
     sigaction(SIGTERM, &sa_sigterm, NULL);
     memset(&sa_sigterm, 0, sizeof(sa_sigterm));
     sa_sigterm.sa_handler = termsig_handler;
     sigaction(SIGTERM, &sa_sigterm, NULL);

+    qemu_init_exec_dir(argv[0]);

 
     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
         switch (ch) {
 
     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
         switch (ch) {


@@ -316,7 +448,40 @@ int main(int argc, char **argv)
             flags |= BDRV_O_SNAPSHOT;
             break;
         case 'n':
             flags |= BDRV_O_SNAPSHOT;
             break;
         case 'n':

-            flags |= BDRV_O_NOCACHE | BDRV_O_CACHE_WB;
+            optarg = (char *) "none";
+            /* fallthrough */
+        case QEMU_NBD_OPT_CACHE:
+            if (seen_cache) {
+                errx(EXIT_FAILURE, "-n and --cache can only be specified once");
+            }
+            seen_cache = true;
+            if (bdrv_parse_cache_flags(optarg, &flags) == -1) {
+                errx(EXIT_FAILURE, "Invalid cache mode `%s'", optarg);
+            }
+            break;
+#ifdef CONFIG_LINUX_AIO
+        case QEMU_NBD_OPT_AIO:
+            if (seen_aio) {
+                errx(EXIT_FAILURE, "--aio can only be specified once");
+            }
+            seen_aio = true;
+            if (!strcmp(optarg, "native")) {
+                flags |= BDRV_O_NATIVE_AIO;
+            } else if (!strcmp(optarg, "threads")) {
+                /* this is the default */
+            } else {
+               errx(EXIT_FAILURE, "invalid aio mode `%s'", optarg);
+            }
+            break;
+#endif
+        case QEMU_NBD_OPT_DISCARD:
+            if (seen_discard) {
+                errx(EXIT_FAILURE, "--discard can only be specified once");
+            }
+            seen_discard = true;
+            if (bdrv_parse_discard_flags(optarg, &flags) == -1) {
+                errx(EXIT_FAILURE, "Invalid discard mode `%s'", optarg);
+            }

             break;
         case 'b':
             bindto = optarg;
             break;
         case 'b':
             bindto = optarg;


@@ -340,6 +505,17 @@ int main(int argc, char **argv)
                 errx(EXIT_FAILURE, "Offset must be positive `%s'", optarg);
             }
             break;
                 errx(EXIT_FAILURE, "Offset must be positive `%s'", optarg);
             }
             break;

+        case 'l':
+            if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) {
+                sn_opts = qemu_opts_parse(&internal_snapshot_opts, optarg, 0);
+                if (!sn_opts) {
+                    errx(EXIT_FAILURE, "Failed in parsing snapshot param `%s'",
+                         optarg);
+                }
+            } else {
+                sn_id_or_name = optarg;
+            }
+            /* fall through */

         case 'r':
             nbdflags |= NBD_FLAG_READ_ONLY;
             flags &= ~BDRV_O_RDWR;
         case 'r':
             nbdflags |= NBD_FLAG_READ_ONLY;
             flags &= ~BDRV_O_RDWR;


@@ -371,6 +547,9 @@ int main(int argc, char **argv)
                 errx(EXIT_FAILURE, "Shared device number must be greater than 0\n");
             }
             break;
                 errx(EXIT_FAILURE, "Shared device number must be greater than 0\n");
             }
             break;

+        case 'f':
+            fmt = optarg;
+            break;

        case 't':
            persistent = 1;
            break;
        case 't':
            persistent = 1;
            break;


@@ -399,9 +578,9 @@ int main(int argc, char **argv)
 
     if (disconnect) {
         fd = open(argv[optind], O_RDWR);
 
     if (disconnect) {
         fd = open(argv[optind], O_RDWR);

-        if (fd == -1)
+        if (fd < 0) {

             err(EXIT_FAILURE, "Cannot open %s", argv[optind]);
             err(EXIT_FAILURE, "Cannot open %s", argv[optind]);

-
+        }

         nbd_disconnect(fd);
 
         close(fd);
         nbd_disconnect(fd);
 
         close(fd);


@@ -416,7 +595,7 @@ int main(int argc, char **argv)
         pid_t pid;
         int ret;
 
         pid_t pid;
         int ret;
 

-        if (qemu_pipe(stderr_fd) == -1) {
+        if (qemu_pipe(stderr_fd) < 0) {

             err(EXIT_FAILURE, "Error setting up communication pipe");
         }
 
             err(EXIT_FAILURE, "Error setting up communication pipe");
         }
 


@@ -426,11 +605,11 @@ int main(int argc, char **argv)
         pid = fork();
         if (pid == 0) {
             close(stderr_fd[0]);
         pid = fork();
         if (pid == 0) {
             close(stderr_fd[0]);

-            ret = qemu_daemon(0, 0);
+            ret = qemu_daemon(1, 0);

 
             /* Temporarily redirect stderr to the parent's pipe...  */
             dup2(stderr_fd[1], STDERR_FILENO);
 
             /* Temporarily redirect stderr to the parent's pipe...  */
             dup2(stderr_fd[1], STDERR_FILENO);

-            if (ret == -1) {
+            if (ret < 0) {

                 err(EXIT_FAILURE, "Failed to daemonize");
             }
 
                 err(EXIT_FAILURE, "Failed to daemonize");
             }
 


@@ -448,11 +627,11 @@ int main(int argc, char **argv)
             while ((ret = read(stderr_fd[0], buf, 1024)) > 0) {
                 errors = true;
                 ret = qemu_write_full(STDERR_FILENO, buf, ret);
             while ((ret = read(stderr_fd[0], buf, 1024)) > 0) {
                 errors = true;
                 ret = qemu_write_full(STDERR_FILENO, buf, ret);

-                if (ret == -1) {
+                if (ret < 0) {

                     exit(EXIT_FAILURE);
                 }
             }
                     exit(EXIT_FAILURE);
                 }
             }

-            if (ret == -1) {
+            if (ret < 0) {

                 err(EXIT_FAILURE, "Cannot read from daemon");
             }
 
                 err(EXIT_FAILURE, "Cannot read from daemon");
             }
 


@@ -463,39 +642,76 @@ int main(int argc, char **argv)
         }
     }
 
         }
     }
 

+    if (device != NULL && sockpath == NULL) {
+        sockpath = g_malloc(128);
+        snprintf(sockpath, 128, SOCKET_PATH, basename(device));
+    }
+
+    qemu_init_main_loop();

     bdrv_init();
     bdrv_init();

+    atexit(bdrv_close_all);
+
+    if (fmt) {
+        drv = bdrv_find_format(fmt);
+        if (!drv) {
+            errx(EXIT_FAILURE, "Unknown file format '%s'", fmt);
+        }
+    } else {
+        drv = NULL;
+    }

 
 

-    bs = bdrv_new("hda");
+    bs = bdrv_new("hda", &error_abort);

 
     srcpath = argv[optind];
 
     srcpath = argv[optind];

-    if ((ret = bdrv_open(bs, srcpath, flags, NULL)) < 0) {
+    ret = bdrv_open(&bs, srcpath, NULL, NULL, flags, drv, &local_err);
+    if (ret < 0) {

         errno = -ret;
         errno = -ret;

-        err(EXIT_FAILURE, "Failed to bdrv_open '%s'", srcpath);
+        err(EXIT_FAILURE, "Failed to bdrv_open '%s': %s", argv[optind],
+            error_get_pretty(local_err));

     }
 
     }
 

-    fd_size = bs->total_sectors * 512;
-
-    if (partition != -1 &&
-        find_partition(bs, partition, &dev_offset, &fd_size))
-        err(EXIT_FAILURE, "Could not find partition %d", partition);
+    if (sn_opts) {
+        ret = bdrv_snapshot_load_tmp(bs,
+                                     qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID),
+                                     qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME),
+                                     &local_err);
+    } else if (sn_id_or_name) {
+        ret = bdrv_snapshot_load_tmp_by_id_or_name(bs, sn_id_or_name,
+                                                   &local_err);
+    }
+    if (ret < 0) {
+        errno = -ret;
+        err(EXIT_FAILURE,
+            "Failed to load snapshot: %s",
+            error_get_pretty(local_err));
+    }

 
 

-    if (device) {
-        int ret;
+    fd_size = bdrv_getlength(bs);

 
 

-        /* Open before spawning new threads.  In the future, we may
-         * drop privileges after opening.
-         */
-        fd = open(device, O_RDWR);
-        if (fd == -1) {
-            err(EXIT_FAILURE, "Failed to open %s", device);
+    if (partition != -1) {
+        ret = find_partition(bs, partition, &dev_offset, &fd_size);
+        if (ret < 0) {
+            errno = -ret;
+            err(EXIT_FAILURE, "Could not find partition %d", partition);

         }
         }

+    }

 
 

-        if (sockpath == NULL) {
-            sockpath = g_malloc(128);
-            snprintf(sockpath, 128, SOCKET_PATH, basename(device));
-        }
+    exp = nbd_export_new(bs, dev_offset, fd_size, nbdflags, nbd_export_closed);
+
+    if (sockpath) {
+        fd = unix_socket_incoming(sockpath);
+    } else {
+        fd = tcp_socket_incoming(bindto, port);
+    }
+
+    if (fd < 0) {
+        return 1;
+    }
+
+    if (device) {
+        int ret;

 
 

-        ret = pthread_create(&client_thread, NULL, nbd_client_thread, &fd);
+        ret = pthread_create(&client_thread, NULL, nbd_client_thread, device);

         if (ret != 0) {
             errx(EXIT_FAILURE, "Failed to create client thread: %s",
                  strerror(ret));
         if (ret != 0) {
             errx(EXIT_FAILURE, "Failed to create client thread: %s",
                  strerror(ret));


@@ -505,75 +721,35 @@ int main(int argc, char **argv)
         memset(&client_thread, 0, sizeof(client_thread));
     }
 
         memset(&client_thread, 0, sizeof(client_thread));
     }
 

-    sharing_fds = g_malloc((shared + 1) * sizeof(int));
+    qemu_set_fd_handler2(fd, nbd_can_accept, nbd_accept, NULL,
+                         (void *)(uintptr_t)fd);

 
 

-    if (sockpath) {
-        sharing_fds[0] = unix_socket_incoming(sockpath);
-    } else {
-        sharing_fds[0] = tcp_socket_incoming(bindto, port);
-    }
-
-    if (sharing_fds[0] == -1)
-        return 1;
-    max_fd = sharing_fds[0];
-    nb_fds++;
-
-    data = qemu_blockalign(bs, NBD_BUFFER_SIZE);
-    if (data == NULL) {
-        errx(EXIT_FAILURE, "Cannot allocate data buffer");
+    /* now when the initialization is (almost) complete, chdir("/")
+     * to free any busy filesystems */
+    if (chdir("/") < 0) {
+        err(EXIT_FAILURE, "Could not chdir to root directory");

     }
 
     }
 

+    state = RUNNING;

     do {
     do {

-        FD_ZERO(&fds);
-        FD_SET(sigterm_fd[0], &fds);
-        for (i = 0; i < nb_fds; i++)
-            FD_SET(sharing_fds[i], &fds);
-
-        do {
-            ret = select(max_fd + 1, &fds, NULL, NULL, NULL);
-        } while (ret == -1 && errno == EINTR);
-        if (ret == -1 || FD_ISSET(sigterm_fd[0], &fds)) {
-            break;
+        main_loop_wait(false);
+        if (state == TERMINATE) {
+            state = TERMINATING;
+            nbd_export_close(exp);
+            nbd_export_put(exp);
+            exp = NULL;

         }
         }

+    } while (state != TERMINATED);

 
 

-        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(bs, sharing_fds[i], fd_size, dev_offset,
-                    &offset, nbdflags, data, NBD_BUFFER_SIZE) != 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_vfree(data);
-
-    close(sharing_fds[0]);

     bdrv_close(bs);
     bdrv_close(bs);

-    g_free(sharing_fds);

     if (sockpath) {
         unlink(sockpath);
     }
 
     if (sockpath) {
         unlink(sockpath);
     }
 

+    if (sn_opts) {
+        qemu_opts_del(sn_opts);
+    }
+

     if (device) {
         void *ret;
         pthread_join(client_thread, &ret);
     if (device) {
         void *ret;
         pthread_join(client_thread, &ret);