virtio: check virtio_load return code

[qemu.git] / qemu-nbd.c

diff --git a/qemu-nbd.c b/qemu-nbd.c
index eb61c33acd490f3aa786db4b9388aa2823d17447..5a0300eb0725ed658cf4fc43bed33b9ca7e40ed4 100644 (file)
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -17,7 +17,7 @@
  */
 
 #include "qemu-common.h"
-#include "block_int.h"
+#include "block.h"
 #include "nbd.h"
 
 #include <stdarg.h>
@@ -37,7 +37,6 @@
 
 static NBDExport *exp;
 static int verbose;
-static char *device;
 static char *srcpath;
 static char *sockpath;
 static bool sigterm_reported;
@@ -127,8 +126,7 @@ static int find_partition(BlockDriverState *bs, int partition,
     }
 
     if (data[510] != 0x55 || data[511] != 0xaa) {
-        errno = -EINVAL;
-        return -1;
+        return -EINVAL;
     }
 
     for (i = 0; i < 4; i++) {
@@ -166,8 +164,7 @@ static int find_partition(BlockDriverState *bs, int partition,
         }
     }
 
-    errno = -ENOENT;
-    return -1;
+    return -ENOENT;
 }
 
 static void termsig_handler(int signum)
@@ -178,6 +175,7 @@ static void termsig_handler(int signum)
 
 static void *show_parts(void *arg)
 {
+    char *device = arg;
     int nbd;
 
     /* linux just needs an open() to trigger
@@ -186,7 +184,7 @@ static void *show_parts(void *arg)
      *     modprobe nbd max_part=63
      */
     nbd = open(device, O_RDWR);
-    if (nbd != -1) {
+    if (nbd >= 0) {
         close(nbd);
     }
     return NULL;
@@ -194,32 +192,39 @@ static void *show_parts(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;
-    int sock;
+    int fd, sock;
     int ret;
     pthread_t show_parts_thread;
 
     sock = unix_socket_outgoing(sockpath);
-    if (sock == -1) {
+    if (sock < 0) {
         goto out;
     }
 
     ret = nbd_receive_negotiate(sock, NULL, &nbdflags,
                                 &size, &blocksize);
-    if (ret == -1) {
+    if (ret < 0) {
+        goto out;
+    }
+
+    fd = open(device, O_RDWR);
+    if (fd < 0) {
+        /* Linux-only, we can use %m in printf.  */
+        fprintf(stderr, "Failed to open %s: %m", device);
         goto out;
     }
 
     ret = nbd_init(fd, sock, nbdflags, size, blocksize);
-    if (ret == -1) {
+    if (ret < 0) {
         goto out;
     }
 
     /* 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",
@@ -261,7 +266,7 @@ static void nbd_accept(void *opaque)
 
     int fd = accept(server_fd, (struct sockaddr *)&addr, &addr_len);
     nbd_started = true;
-    if (fd != -1 && nbd_client_new(exp, fd, nbd_client_closed)) {
+    if (fd >= 0 && nbd_client_new(exp, fd, nbd_client_closed)) {
         nb_fds++;
     }
 }
@@ -273,6 +278,7 @@ int main(int argc, char **argv)
     uint32_t nbdflags = 0;
     bool disconnect = false;
     const char *bindto = "0.0.0.0";
+    char *device = NULL;
     int port = NBD_DEFAULT_PORT;
     off_t fd_size;
     const char *sopt = "hVb:o:p:rsnP:c:dvk:e:t";
@@ -402,9 +408,9 @@ int main(int argc, char **argv)
 
     if (disconnect) {
         fd = open(argv[optind], O_RDWR);
-        if (fd == -1)
+        if (fd < 0) {
             err(EXIT_FAILURE, "Cannot open %s", argv[optind]);
-
+        }
         nbd_disconnect(fd);
 
         close(fd);
@@ -419,7 +425,7 @@ int main(int argc, char **argv)
         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");
         }
 
@@ -429,11 +435,11 @@ int main(int argc, char **argv)
         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);
-            if (ret == -1) {
+            if (ret < 0) {
                 err(EXIT_FAILURE, "Failed to daemonize");
             }
 
@@ -451,11 +457,11 @@ 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);
-                if (ret == -1) {
+                if (ret < 0) {
                     exit(EXIT_FAILURE);
                 }
             }
-            if (ret == -1) {
+            if (ret < 0) {
                 err(EXIT_FAILURE, "Cannot read from daemon");
             }
 
@@ -466,19 +472,9 @@ int main(int argc, char **argv)
         }
     }
 
-    if (device) {
-        /* 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 (sockpath == NULL) {
-            sockpath = g_malloc(128);
-            snprintf(sockpath, 128, SOCKET_PATH, basename(device));
-        }
+    if (device != NULL && sockpath == NULL) {
+        sockpath = g_malloc(128);
+        snprintf(sockpath, 128, SOCKET_PATH, basename(device));
     }
 
     bdrv_init();
@@ -491,11 +487,14 @@ int main(int argc, char **argv)
         err(EXIT_FAILURE, "Failed to bdrv_open '%s'", argv[optind]);
     }
 
-    fd_size = bs->total_sectors * 512;
+    fd_size = bdrv_getlength(bs);
 
-    if (partition != -1 &&
-        find_partition(bs, partition, &dev_offset, &fd_size)) {
-        err(EXIT_FAILURE, "Could not find partition %d", partition);
+    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);
+        }
     }
 
     exp = nbd_export_new(bs, dev_offset, fd_size, nbdflags);
@@ -506,14 +505,14 @@ int main(int argc, char **argv)
         fd = tcp_socket_incoming(bindto, port);
     }
 
-    if (fd == -1) {
+    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));
@@ -527,6 +526,12 @@ int main(int argc, char **argv)
     qemu_set_fd_handler2(fd, nbd_can_accept, nbd_accept, NULL,
                          (void *)(uintptr_t)fd);
 
+    /* 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");
+    }
+
     do {
         main_loop_wait(false);
     } while (!sigterm_reported && (persistent || !nbd_started || nb_fds > 0));