[libvirt] [PATCHv2 26/26] snapshot: wire up new qemu monitor command

No one uses this yet, but it will be important once virDomainSnapshotCreateXML learns a VIR_DOMAIN_SNAPSHOT_DISK_ONLY flag, and the xml allows passing in the new file names. * src/qemu/qemu_monitor.h (qemuMonitorDiskSnapshot): New prototype. * src/qemu/qemu_monitor_text.h (qemuMonitorTextDiskSnapshot): Likewise. * src/qemu/qemu_monitor_json.h (qemuMonitorJSONDiskSnapshot): Likewise. * src/qemu/qemu_monitor.c (qemuMonitorDiskSnapshot): New function. * src/qemu/qemu_monitor_json.c (qemuMonitorJSONDiskSnapshot): Likewise. --- src/qemu/qemu_monitor.c | 24 ++++++++++++++++++++++++ src/qemu/qemu_monitor.h | 4 ++++ src/qemu/qemu_monitor_json.c | 33 +++++++++++++++++++++++++++++++++ src/qemu/qemu_monitor_json.h | 4 ++++ src/qemu/qemu_monitor_text.c | 40 ++++++++++++++++++++++++++++++++++++++++ src/qemu/qemu_monitor_text.h | 4 ++++ 6 files changed, 109 insertions(+), 0 deletions(-) diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c index db6107c..efc49c4 100644 --- a/src/qemu/qemu_monitor.c +++ b/src/qemu/qemu_monitor.c @@ -2391,6 +2391,30 @@ int qemuMonitorDeleteSnapshot(qemuMonitorPtr mon, const char *name) return ret; } +/* Use the snapshot_blkdev command to convert the existing file for + * device into a read-only backing file of a new qcow2 image located + * at file. */ +int +qemuMonitorDiskSnapshot(qemuMonitorPtr mon, const char *device, + const char *file) +{ + int ret; + + VIR_DEBUG("mon=%p, device=%s, file=%s", mon, device, file); + + if (!mon) { + qemuReportError(VIR_ERR_INVALID_ARG, "%s", + _("monitor must not be NULL")); + return -1; + } + + if (mon->json) + ret = qemuMonitorJSONDiskSnapshot(mon, device, file); + else + ret = qemuMonitorTextDiskSnapshot(mon, device, file); + return ret; +} + int qemuMonitorArbitraryCommand(qemuMonitorPtr mon, const char *cmd, char **reply, diff --git a/src/qemu/qemu_monitor.h b/src/qemu/qemu_monitor.h index f241c9e..b988a72 100644 --- a/src/qemu/qemu_monitor.h +++ b/src/qemu/qemu_monitor.h @@ -447,6 +447,10 @@ int qemuMonitorCreateSnapshot(qemuMonitorPtr mon, const char *name); int qemuMonitorLoadSnapshot(qemuMonitorPtr mon, const char *name); int qemuMonitorDeleteSnapshot(qemuMonitorPtr mon, const char *name); +int qemuMonitorDiskSnapshot(qemuMonitorPtr mon, + const char *device, + const char *file); + int qemuMonitorArbitraryCommand(qemuMonitorPtr mon, const char *cmd, char **reply, diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c index 2a9a078..d1fc188 100644 --- a/src/qemu/qemu_monitor_json.c +++ b/src/qemu/qemu_monitor_json.c @@ -2671,6 +2671,39 @@ cleanup: return ret; } +int +qemuMonitorJSONDiskSnapshot(qemuMonitorPtr mon, const char *device, + const char *file) +{ + int ret; + virJSONValuePtr cmd; + virJSONValuePtr reply = NULL; + + cmd = qemuMonitorJSONMakeCommand("snapshot-blkdev-sync", + "s:device", device, + "s:snapshot-file", file, + NULL); + if (!cmd) + return -1; + + if ((ret = qemuMonitorJSONCommand(mon, cmd, &reply)) < 0) + goto cleanup; + + if (qemuMonitorJSONHasError(reply, "CommandNotFound") && + qemuMonitorCheckHMP(mon, "snapshot_blkdev")) { + VIR_DEBUG("snapshot-blkdev-sync command not found, trying HMP"); + ret = qemuMonitorTextDiskSnapshot(mon, device, file); + goto cleanup; + } + + ret = qemuMonitorJSONCheckError(cmd, reply); + +cleanup: + virJSONValueFree(cmd); + virJSONValueFree(reply); + return ret; +} + int qemuMonitorJSONArbitraryCommand(qemuMonitorPtr mon, const char *cmd_str, char **reply_str, diff --git a/src/qemu/qemu_monitor_json.h b/src/qemu/qemu_monitor_json.h index 9512793..a538e9f 100644 --- a/src/qemu/qemu_monitor_json.h +++ b/src/qemu/qemu_monitor_json.h @@ -210,6 +210,10 @@ int qemuMonitorJSONCreateSnapshot(qemuMonitorPtr mon, const char *name); int qemuMonitorJSONLoadSnapshot(qemuMonitorPtr mon, const char *name); int qemuMonitorJSONDeleteSnapshot(qemuMonitorPtr mon, const char *name); +int qemuMonitorJSONDiskSnapshot(qemuMonitorPtr mon, + const char *device, + const char *file); + int qemuMonitorJSONArbitraryCommand(qemuMonitorPtr mon, const char *cmd_str, char **reply_str, diff --git a/src/qemu/qemu_monitor_text.c b/src/qemu/qemu_monitor_text.c index 7bf733d..58e6470 100644 --- a/src/qemu/qemu_monitor_text.c +++ b/src/qemu/qemu_monitor_text.c @@ -2706,6 +2706,46 @@ cleanup: return ret; } +int +qemuMonitorTextDiskSnapshot(qemuMonitorPtr mon, const char *device, + const char *file) +{ + char *cmd = NULL; + char *reply = NULL; + int ret = -1; + char *safename; + + if (!(safename = qemuMonitorEscapeArg(file)) || + virAsprintf(&cmd, "snapshot_blkdev %s \"%s\"", device, safename) < 0) { + virReportOOMError(); + goto cleanup; + } + + if (qemuMonitorHMPCommand(mon, cmd, &reply)) { + qemuReportError(VIR_ERR_OPERATION_FAILED, + _("failed to take snapshot using command '%s'"), cmd); + goto cleanup; + } + + if (strstr(reply, "error while creating qcow2") != NULL) { + qemuReportError(VIR_ERR_OPERATION_FAILED, + _("Failed to take snapshot: %s"), reply); + goto cleanup; + } + + /* XXX Should we scrape 'info block' output for + * 'device:... file=name backing_file=oldname' to make sure the + * command succeeded? */ + + ret = 0; + +cleanup: + VIR_FREE(safename); + VIR_FREE(cmd); + VIR_FREE(reply); + return ret; +} + int qemuMonitorTextArbitraryCommand(qemuMonitorPtr mon, const char *cmd, char **reply) { diff --git a/src/qemu/qemu_monitor_text.h b/src/qemu/qemu_monitor_text.h index b250738..55f78b4 100644 --- a/src/qemu/qemu_monitor_text.h +++ b/src/qemu/qemu_monitor_text.h @@ -206,6 +206,10 @@ int qemuMonitorTextCreateSnapshot(qemuMonitorPtr mon, const char *name); int qemuMonitorTextLoadSnapshot(qemuMonitorPtr mon, const char *name); int qemuMonitorTextDeleteSnapshot(qemuMonitorPtr mon, const char *name); +int qemuMonitorTextDiskSnapshot(qemuMonitorPtr mon, + const char *device, + const char *file); + int qemuMonitorTextArbitraryCommand(qemuMonitorPtr mon, const char *cmd, char **reply); -- 1.7.4.4