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author | ths <ths@c046a42c-6fe2-441c-8c8c-71466251a162> | 2008-07-03 12:45:02 +0000 |
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committer | ths <ths@c046a42c-6fe2-441c-8c8c-71466251a162> | 2008-07-03 12:45:02 +0000 |
commit | 3b05a8e91bf15e1858f3f3618069dbc78e55b88e (patch) | |
tree | 99dcfae1de91d07cf05ad8c88edbd021fb87f83d /qemu-nbd.c | |
parent | 2f7264888ab4a9595a40bd045f58101e5ccd2f0a (diff) | |
download | hqemu-3b05a8e91bf15e1858f3f3618069dbc78e55b88e.zip hqemu-3b05a8e91bf15e1858f3f3618069dbc78e55b88e.tar.gz |
Allow to share a disk image via nbd, by Laurent Vivier.
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4837 c046a42c-6fe2-441c-8c8c-71466251a162
Diffstat (limited to 'qemu-nbd.c')
-rw-r--r-- | qemu-nbd.c | 96 |
1 files changed, 75 insertions, 21 deletions
@@ -55,6 +55,7 @@ static void usage(const char *name) " -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" " -v, --verbose display extra debugging information\n" " -h, --help display this help and exit\n" " -V, --version output version information and exit\n" @@ -182,14 +183,13 @@ int main(int argc, char **argv) bool disconnect = false; const char *bindto = "0.0.0.0"; int port = 1024; - int sock, csock; struct sockaddr_in addr; socklen_t addr_len = sizeof(addr); off_t fd_size; char *device = NULL; char *socket = NULL; char sockpath[128]; - const char *sopt = "hVbo:p:rsnP:c:dvk:"; + const char *sopt = "hVbo:p:rsnP:c:dvk:e:"; struct option lopt[] = { { "help", 0, 0, 'h' }, { "version", 0, 0, 'V' }, @@ -203,6 +203,7 @@ int main(int argc, char **argv) { "disconnect", 0, 0, 'd' }, { "snapshot", 0, 0, 's' }, { "nocache", 0, 0, 'n' }, + { "shared", 1, 0, 'e' }, { "verbose", 0, 0, 'v' }, { NULL, 0, 0, 0 } }; @@ -212,9 +213,15 @@ int main(int argc, char **argv) char *end; int flags = 0; int partition = -1; - int fd; int ret; + int shared = 1; uint8_t *data; + fd_set fds; + int *sharing_fds; + int fd; + int i; + int nb_fds = 0; + int max_fd; while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) { switch (ch) { @@ -267,6 +274,15 @@ int main(int argc, char **argv) case 'c': device = optarg; break; + case 'e': + shared = strtol(optarg, &end, 0); + if (*end) { + errx(EINVAL, "Invalid shared device number '%s'", optarg); + } + if (shared < 1) { + errx(EINVAL, "Shared device number must be greater than 0\n"); + } + break; case 'v': verbose = 1; break; @@ -320,8 +336,10 @@ int main(int argc, char **argv) errx(errno, "Could not find partition %d", partition); if (device) { - pid_t pid; - if (!verbose) + pid_t pid; + int sock; + + if (!verbose) daemon(0, 0); /* detach client and server */ if (socket == NULL) { @@ -384,33 +402,69 @@ int main(int argc, char **argv) /* children */ } + sharing_fds = qemu_malloc((shared + 1) * sizeof(int)); + if (sharing_fds == NULL) + errx(ENOMEM, "Cannot allocate sharing fds"); + if (socket) { - sock = unix_socket_incoming(socket); + sharing_fds[0] = unix_socket_incoming(socket); } else { - sock = tcp_socket_incoming(bindto, port); + sharing_fds[0] = tcp_socket_incoming(bindto, port); } - if (sock == -1) + if (sharing_fds[0] == -1) return 1; + max_fd = sharing_fds[0]; + nb_fds++; - csock = accept(sock, - (struct sockaddr *)&addr, - &addr_len); - if (csock == -1) - return 1; + data = qemu_memalign(512, NBD_BUFFER_SIZE); + if (data == NULL) + errx(ENOMEM, "Cannot allocate data buffer"); - /* new fd_size is calculated by find_partition */ - if (nbd_negotiate(bs, csock, fd_size) == -1) - return 1; + do { - data = qemu_memalign(512, NBD_BUFFER_SIZE); - while (nbd_trip(bs, csock, fd_size, dev_offset, &offset, readonly, - data, NBD_BUFFER_SIZE) == 0); + 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(bs, sharing_fds[i], fd_size, dev_offset, + &offset, readonly, 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(bs, sharing_fds[nb_fds], fd_size) != -1) { + if (sharing_fds[nb_fds] > max_fd) + max_fd = sharing_fds[nb_fds]; + nb_fds++; + } + } + } + } while (nb_fds > 1); qemu_free(data); - close(csock); - close(sock); + close(sharing_fds[0]); bdrv_close(bs); + qemu_free(sharing_fds); if (socket) unlink(socket); |