| Message ID | CAERYnoaz3iUgA=TWuTaDWvovCiDpwgJst_5UjUDsg9z+8_z0tA@mail.gmail.com |
|---|---|
| State | New |
| Headers | show |
On 12/07/2011 05:23 AM, Chunyan Liu wrote: > Add -f option to qemu-nbd. New implementation. Do not need nbd_setup. > Tested and worked. > > Signed-off-by: Chunyan Liu <cyliu@suse.com <mailto:cyliu@suse.com>> > --- > qemu-nbd.c | 71 +++++++++++++++++++++++++++++++++++++++++------------------ > 1 files changed, 49 insertions(+), 22 deletions(-) Looks much nicer, thanks. Paolo
On Wed, Dec 7, 2011 at 4:23 AM, Chunyan Liu <cyliu@suse.com> wrote: Overall looks good, some suggestions: > @@ -53,7 +53,7 @@ static void usage(const char *name) > " -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" > +" (default /var/lock/qemu-nbd-%s)\n" > " -r, --read-only export read-only\n" > " -P, --partition=NUM only expose partition NUM\n" > " -s, --snapshot use snapshot file\n" > @@ -67,7 +67,7 @@ static void usage(const char *name) > " -V, --version output version information and exit\n" > "\n" > "Report bugs to <anthony@codemonkey.ws>\n" > - , name, NBD_DEFAULT_PORT, "DEVICE"); > + , name, NBD_DEFAULT_PORT, "PID"); > } Since we're not using the SOCKET_PATH format string anymore it's nicer to drop this format string argument and just change to "(default /var/lock/qemu-nbd-PID" above. > + fd = open(device, O_RDWR); > + if (fd == -1) { > + fprintf(stderr, "Failed to open %s", device); Missing \n in string. > + goto out; > + } > + > + ret = nbd_init(fd, sock, nbdflags, size, blocksize); > + if (ret == -1) { > + goto out; > + } > + } else { > + int i = 0; > + int max_nbd = 16; > + for (i = 0; i < max_nbd; i++) { > + if (!asprintf(&device, "/dev/nbd%d", i)) { asprintf() is GNU and BSD only (not C or POSIX). I suggest using g_strdup_printf() instead which is guaranteed to be available because QEMU builds against glib: http://developer.gnome.org/glib/2.28/glib-String-Utility-Functions.html#g-strdup-printf > + continue; > + } > > + > + fd = open(device, O_RDWR); > + if (fd == -1 || nbd_init(fd, sock, nbdflags, size, blocksize) > == -1) { nbd_init() does not close(fd) on failure. Please separate the open() and nbd_init() error cases and close the fd. Stefan
diff --git a/qemu-nbd.c b/qemu-nbd.c index 291cba2..ba66da1 100644 --- a/qemu-nbd.c +++ b/qemu-nbd.c @@ -33,7 +33,7 @@ #include <libgen.h> #include <pthread.h> -#define SOCKET_PATH "/var/lock/qemu-nbd-%s" +#define SOCKET_PATH "/var/lock/qemu-nbd-%d" #define NBD_BUFFER_SIZE (1024*1024) @@ -53,7 +53,7 @@ static void usage(const char *name) " -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" +" (default /var/lock/qemu-nbd-%s)\n" " -r, --read-only export read-only\n" " -P, --partition=NUM only expose partition NUM\n" " -s, --snapshot use snapshot file\n" @@ -67,7 +67,7 @@ static void usage(const char *name) " -V, --version output version information and exit\n" "\n" "Report bugs to <anthony@codemonkey.ws>\n" - , name, NBD_DEFAULT_PORT, "DEVICE"); + , name, NBD_DEFAULT_PORT, "PID"); } static void version(const char *name) @@ -194,7 +194,8 @@ static void *show_parts(void *arg) static void *nbd_client_thread(void *arg) { - int fd = *(int *)arg; + int fd = -1; + int find = *(int *)arg; off_t size; size_t blocksize; uint32_t nbdflags; @@ -215,9 +216,38 @@ static void *nbd_client_thread(void *arg) goto out; } - ret = nbd_init(fd, sock, nbdflags, size, blocksize); - if (ret == -1) { - goto out; + if (!find) { + fd = open(device, O_RDWR); + if (fd == -1) { + fprintf(stderr, "Failed to open %s", device); + goto out; + } + + ret = nbd_init(fd, sock, nbdflags, size, blocksize); + if (ret == -1) { + goto out; + } + } else { + int i = 0; + int max_nbd = 16; + for (i = 0; i < max_nbd; i++) { + if (!asprintf(&device, "/dev/nbd%d", i)) { + continue; + } + + fd = open(device, O_RDWR); + if (fd == -1 || nbd_init(fd, sock, nbdflags, size, blocksize) == -1) { + free(device); + continue; + } + + break; + } + + if (i >= max_nbd) { + fprintf(stderr, "Fail to find a free nbd device\n"); + goto out; + } }
Add -f option to qemu-nbd. New implementation. Do not need nbd_setup. Tested and worked. Signed-off-by: Chunyan Liu <cyliu@suse.com> --- qemu-nbd.c | 71 +++++++++++++++++++++++++++++++++++++++++------------------ 1 files changed, 49 insertions(+), 22 deletions(-) /* update partition table */ @@ -256,7 +286,7 @@ int main(int argc, char **argv) struct sockaddr_in addr; socklen_t addr_len = sizeof(addr); off_t fd_size; - const char *sopt = "hVb:o:p:rsnP:c:dvk:e:t"; + const char *sopt = "hVb:o:p:rsnP:c:dvk:e:tf"; struct option lopt[] = { { "help", 0, NULL, 'h' }, { "version", 0, NULL, 'V' }, @@ -273,6 +303,7 @@ int main(int argc, char **argv) { "shared", 1, NULL, 'e' }, { "persistent", 0, NULL, 't' }, { "verbose", 0, NULL, 'v' }, + { "find", 0, NULL, 'f'}, { NULL, 0, NULL, 0 } }; int ch; @@ -291,6 +322,7 @@ int main(int argc, char **argv) int nb_fds = 0; int max_fd; int persistent = 0; + int find = 0; pthread_t client_thread; /* The client thread uses SIGTERM to interrupt the server. A signal @@ -374,6 +406,9 @@ int main(int argc, char **argv) case 'v': verbose = 1; break; + case 'f': + find = 1; + break; case 'V': version(argv[0]); exit(0); @@ -408,7 +443,7 @@ int main(int argc, char **argv) return 0; } - if (device && !verbose) { + if ((device || find) && !verbose) { int stderr_fd[2]; pid_t pid; int ret; @@ -460,18 +495,10 @@ 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 (device || find) { if (sockpath == NULL) { sockpath = g_malloc(128); - snprintf(sockpath, 128, SOCKET_PATH, basename(device)); + snprintf(sockpath, 128, SOCKET_PATH, getpid()); } } @@ -503,10 +530,10 @@ int main(int argc, char **argv) if (sharing_fds[0] == -1) return 1; - if (device) { + if (device || find) { int ret; - ret = pthread_create(&client_thread, NULL, nbd_client_thread, &fd); + ret = pthread_create(&client_thread, NULL, nbd_client_thread, &find); if (ret != 0) { errx(EXIT_FAILURE, "Failed to create client thread: %s", strerror(ret)); @@ -574,7 +601,7 @@ int main(int argc, char **argv) unlink(sockpath); } - if (device) { + if (device || find) { void *ret; pthread_join(client_thread, &ret); exit(ret != NULL);