Now it is possible to directly export an internal snapshot, which can be used to probe the snapshot's contents without qemu-img convert.
Signed-off-by: Wenchao Xia <xiaw...@linux.vnet.ibm.com> --- qemu-nbd.c | 54 +++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 files changed, 53 insertions(+), 1 deletions(-) diff --git a/qemu-nbd.c b/qemu-nbd.c index c26c98e..e450d04 100644 --- a/qemu-nbd.c +++ b/qemu-nbd.c @@ -20,6 +20,7 @@ #include "block/block.h" #include "block/nbd.h" #include "qemu/main-loop.h" +#include "block/snapshot.h" #include <stdarg.h> #include <stdio.h> @@ -304,6 +305,23 @@ static void nbd_accept(void *opaque) } } +#define SNAPSHOT_OPT_ID "id" +#define SNAPSHOT_OPT_NAME "name" + +static QEMUOptionParameter snapshot_options[] = { + { + .name = SNAPSHOT_OPT_ID, + .type = OPT_STRING, + .help = "snapshot id" + }, + { + .name = SNAPSHOT_OPT_NAME, + .type = OPT_STRING, + .help = "snapshot name" + }, + { NULL } +}; + int main(int argc, char **argv) { BlockDriverState *bs; @@ -315,7 +333,10 @@ int main(int argc, char **argv) char *device = NULL; int port = NBD_DEFAULT_PORT; off_t fd_size; - const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:t"; + QEMUOptionParameter *sn_param = NULL; + const QEMUOptionParameter *sn_param_id, *sn_param_name; + const char *sn_id = NULL, *sn_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' }, @@ -328,6 +349,7 @@ int main(int argc, char **argv) { "connect", 1, NULL, 'c' }, { "disconnect", 0, NULL, 'd' }, { "snapshot", 0, NULL, 's' }, + { "snapshot-load", 1, NULL, 'l' }, { "nocache", 0, NULL, 'n' }, { "cache", 1, NULL, QEMU_NBD_OPT_CACHE }, #ifdef CONFIG_LINUX_AIO @@ -428,6 +450,14 @@ int main(int argc, char **argv) errx(EXIT_FAILURE, "Offset must be positive `%s'", optarg); } break; + case 'l': + sn_param = parse_option_parameters(optarg, + snapshot_options, sn_param); + if (!sn_param) { + errx(EXIT_FAILURE, + "Invalid snapshot-load options '%s'", optarg); + } + /* fall through */ case 'r': nbdflags |= NBD_FLAG_READ_ONLY; flags &= ~BDRV_O_RDWR; @@ -581,6 +611,24 @@ int main(int argc, char **argv) error_get_pretty(local_err)); } + if (sn_param) { + sn_param_id = get_option_parameter(sn_param, SNAPSHOT_OPT_ID); + sn_param_name = get_option_parameter(sn_param, SNAPSHOT_OPT_NAME); + if (sn_param_id) { + sn_id = sn_param_id->value.s; + } + if (sn_param_name) { + sn_name = sn_param_name->value.s; + } + ret = bdrv_snapshot_load_tmp(bs, sn_id, sn_name, &local_err); + if (ret < 0) { + errno = -ret; + err(EXIT_FAILURE, + "Failed to load snapshot, reason:\n%s", + error_get_pretty(local_err)); + } + } + fd_size = bdrv_getlength(bs); if (partition != -1) { @@ -641,6 +689,10 @@ int main(int argc, char **argv) unlink(sockpath); } + if (sn_param) { + free_option_parameters(sn_param); + } + if (device) { void *ret; pthread_join(client_thread, &ret); -- 1.7.1