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author | Wenchao Xia <xiawenc@linux.vnet.ibm.com> | 2013-12-04 17:10:55 +0800 |
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committer | Stefan Hajnoczi <stefanha@redhat.com> | 2013-12-04 15:19:00 +0100 |
commit | 8c116b0e4141400f8d43a7e6dac8ff3adcc8aadd (patch) | |
tree | 758e8c14c3f45d51d1561d5bb5d2c72b7a35f0f7 /qemu-nbd.c | |
parent | 7b4c4781e390a041fa0ef70817678f1b97fc6db6 (diff) | |
download | qemu-8c116b0e4141400f8d43a7e6dac8ff3adcc8aadd.zip qemu-8c116b0e4141400f8d43a7e6dac8ff3adcc8aadd.tar.gz qemu-8c116b0e4141400f8d43a7e6dac8ff3adcc8aadd.tar.bz2 |
qemu-nbd: support internal snapshot export
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 <xiawenc@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'qemu-nbd.c')
-rw-r--r-- | qemu-nbd.c | 46 |
1 files changed, 44 insertions, 2 deletions
@@ -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> @@ -79,7 +80,14 @@ static void usage(const char *name) "\n" "Block device options:\n" " -r, --read-only export read-only\n" -" -s, --snapshot use snapshot file\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 @@ -315,7 +323,9 @@ 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"; + 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' }, @@ -328,6 +338,7 @@ int main(int argc, char **argv) { "connect", 1, NULL, 'c' }, { "disconnect", 0, NULL, 'd' }, { "snapshot", 0, NULL, 's' }, + { "load-snapshot", 1, NULL, 'l' }, { "nocache", 0, NULL, 'n' }, { "cache", 1, NULL, QEMU_NBD_OPT_CACHE }, #ifdef CONFIG_LINUX_AIO @@ -428,6 +439,17 @@ int main(int argc, char **argv) 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; @@ -581,6 +603,22 @@ int main(int argc, char **argv) error_get_pretty(local_err)); } + 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)); + } + fd_size = bdrv_getlength(bs); if (partition != -1) { @@ -641,6 +679,10 @@ int main(int argc, char **argv) unlink(sockpath); } + if (sn_opts) { + qemu_opts_del(sn_opts); + } + if (device) { void *ret; pthread_join(client_thread, &ret); |