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snapshot: prepare to remove transient snapshot metadata

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This patch is mostly code motion - moving some functions out
of qemu_driver and into qemu_domain so they can be reused by
multiple qemu_* files (since qemu_driver.h must not grow).
It also adds a new helper function, qemuDomainRemoveInactive,
which will be used in the next patch.

* src/qemu/qemu_domain.h (qemuFindQemuImgBinary)
(qemuDomainSnapshotWriteMetadata, qemuDomainSnapshotForEachQcow2)
(qemuDomainSnapshotDiscard, qemuDomainSnapshotDiscardAll)
(qemuDomainRemoveInactive): New prototypes.
(struct qemu_snap_remove): New struct.
* src/qemu/qemu_domain.c (qemuDomainRemoveInactive)
(qemuDomainSnapshotDiscardAllMetadata): New functions.
(qemuFindQemuImgBinary, qemuDomainSnapshotWriteMetadata)
(qemuDomainSnapshotForEachQcow2, qemuDomainSnapshotDiscard)
(qemuDomainSnapshotDiscardAll): Move here...
* src/qemu/qemu_driver.c (qemuFindQemuImgBinary)
(qemuDomainSnapshotWriteMetadata, qemuDomainSnapshotForEachQcow2)
(qemuDomainSnapshotDiscard, qemuDomainSnapshotDiscardAll): ...from
here.
(qemuDomainUndefineFlags): Update caller.
* src/conf/domain_conf.c (virDomainRemoveInactive): Doc fixes.
This commit is contained in:
Eric Blake 2011-09-21 13:08:51 -06:00 committed by Daniel Veillard
parent e6966fa79a
commit bcf974b94b
5 changed files with 301 additions and 250 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
src/conf/domain_conf.c
View File

@ -1438,9 +1438,9 @@ virDomainObjGetPersistentDef(virCapsPtr caps,
}
/*
* The caller must hold a lock on the driver owning 'doms',
* The caller must hold a lock on the driver owning 'doms',
* and must also have locked 'dom', to ensure no one else
* is either waiting for 'dom' or still usingn it
* is either waiting for 'dom' or still using it
*/
void virDomainRemoveInactive(virDomainObjListPtr doms,
virDomainObjPtr dom)

260
src/qemu/qemu_domain.c
View File

@ -1296,3 +1296,263 @@ cleanup:
VIR_FREE(message);
return ret;
}
/* Locate an appropriate 'qemu-img' binary. */
const char *
qemuFindQemuImgBinary(struct qemud_driver *driver)
{
if (!driver->qemuImgBinary) {
driver->qemuImgBinary = virFindFileInPath("kvm-img");
if (!driver->qemuImgBinary)
driver->qemuImgBinary = virFindFileInPath("qemu-img");
if (!driver->qemuImgBinary)
qemuReportError(VIR_ERR_INTERNAL_ERROR,
"%s", _("unable to find kvm-img or qemu-img"));
}
return driver->qemuImgBinary;
}
int
qemuDomainSnapshotWriteMetadata(virDomainObjPtr vm,
virDomainSnapshotObjPtr snapshot,
char *snapshotDir)
{
int fd = -1;
char *newxml = NULL;
int ret = -1;
char *snapDir = NULL;
char *snapFile = NULL;
char uuidstr[VIR_UUID_STRING_BUFLEN];
char *tmp;
virUUIDFormat(vm->def->uuid, uuidstr);
newxml = virDomainSnapshotDefFormat(uuidstr, snapshot->def,
VIR_DOMAIN_XML_SECURE, 1);
if (newxml == NULL) {
virReportOOMError();
return -1;
}
if (virAsprintf(&snapDir, "%s/%s", snapshotDir, vm->def->name) < 0) {
virReportOOMError();
goto cleanup;
}
if (virFileMakePath(snapDir) < 0) {
virReportSystemError(errno, _("cannot create snapshot directory '%s'"),
snapDir);
goto cleanup;
}
if (virAsprintf(&snapFile, "%s/%s.xml", snapDir, snapshot->def->name) < 0) {
virReportOOMError();
goto cleanup;
}
fd = open(snapFile, O_CREAT|O_TRUNC|O_WRONLY, S_IRUSR|S_IWUSR);
if (fd < 0) {
qemuReportError(VIR_ERR_OPERATION_FAILED,
_("failed to create snapshot file '%s'"), snapFile);
goto cleanup;
}
if (virAsprintf(&tmp, "snapshot-edit %s", vm->def->name) < 0) {
virReportOOMError();
goto cleanup;
}
virEmitXMLWarning(fd, snapshot->def->name, tmp);
VIR_FREE(tmp);
if (safewrite(fd, newxml, strlen(newxml)) != strlen(newxml)) {
virReportSystemError(errno, _("Failed to write snapshot data to %s"),
snapFile);
goto cleanup;
}
ret = 0;
cleanup:
VIR_FREE(snapFile);
VIR_FREE(snapDir);
VIR_FREE(newxml);
VIR_FORCE_CLOSE(fd);
return ret;
}
/* The domain is expected to be locked and inactive. Return -1 on normal
* failure, 1 if we skipped a disk due to try_all. */
int
qemuDomainSnapshotForEachQcow2(struct qemud_driver *driver,
virDomainObjPtr vm,
virDomainSnapshotObjPtr snap,
const char *op,
bool try_all)
{
const char *qemuimgarg[] = { NULL, "snapshot", NULL, NULL, NULL, NULL };
int i;
bool skipped = false;
qemuimgarg[0] = qemuFindQemuImgBinary(driver);
if (qemuimgarg[0] == NULL) {
/* qemuFindQemuImgBinary set the error */
return -1;
}
qemuimgarg[2] = op;
qemuimgarg[3] = snap->def->name;
for (i = 0; i < vm->def->ndisks; i++) {
/* FIXME: we also need to handle LVM here */
/* FIXME: if we fail halfway through this loop, we are in an
* inconsistent state. I'm not quite sure what to do about that
*/
if (vm->def->disks[i]->device == VIR_DOMAIN_DISK_DEVICE_DISK) {
if (!vm->def->disks[i]->driverType ||
STRNEQ(vm->def->disks[i]->driverType, "qcow2")) {
if (try_all) {
/* Continue on even in the face of error, since other
* disks in this VM may have the same snapshot name.
*/
VIR_WARN("skipping snapshot action on %s",
vm->def->disks[i]->dst);
skipped = true;
continue;
}
qemuReportError(VIR_ERR_OPERATION_INVALID,
_("Disk device '%s' does not support"
" snapshotting"),
vm->def->disks[i]->dst);
return -1;
}
qemuimgarg[4] = vm->def->disks[i]->src;
if (virRun(qemuimgarg, NULL) < 0) {
if (try_all) {
VIR_WARN("skipping snapshot action on %s",
vm->def->disks[i]->info.alias);
skipped = true;
continue;
}
return -1;
}
}
}
return skipped ? 1 : 0;
}
/* Discard one snapshot (or its metadata), without reparenting any children. */
int
qemuDomainSnapshotDiscard(struct qemud_driver *driver,
virDomainObjPtr vm,
virDomainSnapshotObjPtr snap,
bool update_current,
bool metadata_only)
{
char *snapFile = NULL;
int ret = -1;
qemuDomainObjPrivatePtr priv;
virDomainSnapshotObjPtr parentsnap = NULL;
if (!metadata_only) {
if (!virDomainObjIsActive(vm)) {
/* Ignore any skipped disks */
if (qemuDomainSnapshotForEachQcow2(driver, vm, snap, "-d",
true) < 0)
goto cleanup;
} else {
priv = vm->privateData;
qemuDomainObjEnterMonitorWithDriver(driver, vm);
/* we continue on even in the face of error */
qemuMonitorDeleteSnapshot(priv->mon, snap->def->name);
qemuDomainObjExitMonitorWithDriver(driver, vm);
}
}
if (virAsprintf(&snapFile, "%s/%s/%s.xml", driver->snapshotDir,
vm->def->name, snap->def->name) < 0) {
virReportOOMError();
goto cleanup;
}
if (snap == vm->current_snapshot) {
if (update_current && snap->def->parent) {
parentsnap = virDomainSnapshotFindByName(&vm->snapshots,
snap->def->parent);
if (!parentsnap) {
VIR_WARN("missing parent snapshot matching name '%s'",
snap->def->parent);
} else {
parentsnap->def->current = true;
if (qemuDomainSnapshotWriteMetadata(vm, parentsnap,
driver->snapshotDir) < 0) {
VIR_WARN("failed to set parent snapshot '%s' as current",
snap->def->parent);
parentsnap->def->current = false;
parentsnap = NULL;
}
}
}
vm->current_snapshot = parentsnap;
}
if (unlink(snapFile) < 0)
VIR_WARN("Failed to unlink %s", snapFile);
virDomainSnapshotObjListRemove(&vm->snapshots, snap);
ret = 0;
cleanup:
VIR_FREE(snapFile);
return ret;
}
/* Hash iterator callback to discard multiple snapshots. */
void qemuDomainSnapshotDiscardAll(void *payload,
const void *name ATTRIBUTE_UNUSED,
void *data)
{
virDomainSnapshotObjPtr snap = payload;
struct qemu_snap_remove *curr = data;
int err;
if (snap->def->current)
curr->current = true;
err = qemuDomainSnapshotDiscard(curr->driver, curr->vm, snap, false,
curr->metadata_only);
if (err && !curr->err)
curr->err = err;
}
int
qemuDomainSnapshotDiscardAllMetadata(struct qemud_driver *driver,
virDomainObjPtr vm)
{
struct qemu_snap_remove rem;
rem.driver = driver;
rem.vm = vm;
rem.metadata_only = true;
rem.err = 0;
virHashForEach(vm->snapshots.objs, qemuDomainSnapshotDiscardAll, &rem);
/* XXX also do rmdir ? */
return rem.err;
}
/*
* The caller must hold a lock on both driver and vm, and there must
* be no remaining references to vm.
*/
void
qemuDomainRemoveInactive(struct qemud_driver *driver,
virDomainObjPtr vm)
{
/* Remove any snapshot metadata prior to removing the domain */
if (qemuDomainSnapshotDiscardAllMetadata(driver, vm) < 0) {
VIR_WARN("unable to remove all snapshots for domain %s",
vm->def->name);
}
virDomainRemoveInactive(&driver->domains, vm);
}

36
src/qemu/qemu_domain.h
View File

@ -237,4 +237,40 @@ int qemuDomainAppendLog(struct qemud_driver *driver,
int logFD,
const char *fmt, ...) ATTRIBUTE_FMT_PRINTF(4, 5);
const char *qemuFindQemuImgBinary(struct qemud_driver *driver);
int qemuDomainSnapshotWriteMetadata(virDomainObjPtr vm,
virDomainSnapshotObjPtr snapshot,
char *snapshotDir);
int qemuDomainSnapshotForEachQcow2(struct qemud_driver *driver,
virDomainObjPtr vm,
virDomainSnapshotObjPtr snap,
const char *op,
bool try_all);
int qemuDomainSnapshotDiscard(struct qemud_driver *driver,
virDomainObjPtr vm,
virDomainSnapshotObjPtr snap,
bool update_current,
bool metadata_only);
struct qemu_snap_remove {
struct qemud_driver *driver;
virDomainObjPtr vm;
int err;
bool metadata_only;
bool current;
};
void qemuDomainSnapshotDiscardAll(void *payload,
const void *name,
void *data);
int qemuDomainSnapshotDiscardAllMetadata(struct qemud_driver *driver,
virDomainObjPtr vm);
void qemuDomainRemoveInactive(struct qemud_driver *driver,
virDomainObjPtr vm);
#endif /* __QEMU_DOMAIN_H__ */

249
src/qemu/qemu_driver.c
View File

@ -1596,243 +1596,6 @@ cleanup:
}
/* Locate an appropriate 'qemu-img' binary. */
static const char *
qemuFindQemuImgBinary(struct qemud_driver *driver)
{
if (!driver->qemuImgBinary) {
driver->qemuImgBinary = virFindFileInPath("kvm-img");
if (!driver->qemuImgBinary)
driver->qemuImgBinary = virFindFileInPath("qemu-img");
if (!driver->qemuImgBinary)
qemuReportError(VIR_ERR_INTERNAL_ERROR,
"%s", _("unable to find kvm-img or qemu-img"));
}
return driver->qemuImgBinary;
}
static int
qemuDomainSnapshotWriteMetadata(virDomainObjPtr vm,
virDomainSnapshotObjPtr snapshot,
char *snapshotDir)
{
int fd = -1;
char *newxml = NULL;
int ret = -1;
char *snapDir = NULL;
char *snapFile = NULL;
char uuidstr[VIR_UUID_STRING_BUFLEN];
char *tmp;
virUUIDFormat(vm->def->uuid, uuidstr);
newxml = virDomainSnapshotDefFormat(uuidstr, snapshot->def,
VIR_DOMAIN_XML_SECURE, 1);
if (newxml == NULL) {
virReportOOMError();
return -1;
}
if (virAsprintf(&snapDir, "%s/%s", snapshotDir, vm->def->name) < 0) {
virReportOOMError();
goto cleanup;
}
if (virFileMakePath(snapDir) < 0) {
virReportSystemError(errno, _("cannot create snapshot directory '%s'"),
snapDir);
goto cleanup;
}
if (virAsprintf(&snapFile, "%s/%s.xml", snapDir, snapshot->def->name) < 0) {
virReportOOMError();
goto cleanup;
}
fd = open(snapFile, O_CREAT|O_TRUNC|O_WRONLY, S_IRUSR|S_IWUSR);
if (fd < 0) {
qemuReportError(VIR_ERR_OPERATION_FAILED,
_("failed to create snapshot file '%s'"), snapFile);
goto cleanup;
}
if (virAsprintf(&tmp, "snapshot-edit %s", vm->def->name) < 0) {
virReportOOMError();
goto cleanup;
}
virEmitXMLWarning(fd, snapshot->def->name, tmp);
VIR_FREE(tmp);
if (safewrite(fd, newxml, strlen(newxml)) != strlen(newxml)) {
virReportSystemError(errno, _("Failed to write snapshot data to %s"),
snapFile);
goto cleanup;
}
ret = 0;
cleanup:
VIR_FREE(snapFile);
VIR_FREE(snapDir);
VIR_FREE(newxml);
VIR_FORCE_CLOSE(fd);
return ret;
}
/* The domain is expected to be locked and inactive. Return -1 on normal
* failure, 1 if we skipped a disk due to try_all. */
static int
qemuDomainSnapshotForEachQcow2(struct qemud_driver *driver,
virDomainObjPtr vm,
virDomainSnapshotObjPtr snap,
const char *op,
bool try_all)
{
const char *qemuimgarg[] = { NULL, "snapshot", NULL, NULL, NULL, NULL };
int i;
bool skipped = false;
qemuimgarg[0] = qemuFindQemuImgBinary(driver);
if (qemuimgarg[0] == NULL) {
/* qemuFindQemuImgBinary set the error */
return -1;
}
qemuimgarg[2] = op;
qemuimgarg[3] = snap->def->name;
for (i = 0; i < vm->def->ndisks; i++) {
/* FIXME: we also need to handle LVM here */
/* FIXME: if we fail halfway through this loop, we are in an
* inconsistent state. I'm not quite sure what to do about that
*/
if (vm->def->disks[i]->device == VIR_DOMAIN_DISK_DEVICE_DISK) {
if (!vm->def->disks[i]->driverType ||
STRNEQ(vm->def->disks[i]->driverType, "qcow2")) {
if (try_all) {
/* Continue on even in the face of error, since other
* disks in this VM may have the same snapshot name.
*/
VIR_WARN("skipping snapshot action on %s",
vm->def->disks[i]->dst);
skipped = true;
continue;
}
qemuReportError(VIR_ERR_OPERATION_INVALID,
_("Disk device '%s' does not support"
" snapshotting"),
vm->def->disks[i]->dst);
return -1;
}
qemuimgarg[4] = vm->def->disks[i]->src;
if (virRun(qemuimgarg, NULL) < 0) {
if (try_all) {
VIR_WARN("skipping snapshot action on %s",
vm->def->disks[i]->info.alias);
skipped = true;
continue;
}
return -1;
}
}
}
return skipped ? 1 : 0;
}
/* Discard one snapshot (or its metadata), without reparenting any children. */
static int
qemuDomainSnapshotDiscard(struct qemud_driver *driver,
virDomainObjPtr vm,
virDomainSnapshotObjPtr snap,
bool update_current,
bool metadata_only)
{
char *snapFile = NULL;
int ret = -1;
qemuDomainObjPrivatePtr priv;
virDomainSnapshotObjPtr parentsnap = NULL;
if (!metadata_only) {
if (!virDomainObjIsActive(vm)) {
/* Ignore any skipped disks */
if (qemuDomainSnapshotForEachQcow2(driver, vm, snap, "-d",
true) < 0)
goto cleanup;
} else {
priv = vm->privateData;
qemuDomainObjEnterMonitorWithDriver(driver, vm);
/* we continue on even in the face of error */
qemuMonitorDeleteSnapshot(priv->mon, snap->def->name);
qemuDomainObjExitMonitorWithDriver(driver, vm);
}
}
if (virAsprintf(&snapFile, "%s/%s/%s.xml", driver->snapshotDir,
vm->def->name, snap->def->name) < 0) {
virReportOOMError();
goto cleanup;
}
if (snap == vm->current_snapshot) {
if (update_current && snap->def->parent) {
parentsnap = virDomainSnapshotFindByName(&vm->snapshots,
snap->def->parent);
if (!parentsnap) {
VIR_WARN("missing parent snapshot matching name '%s'",
snap->def->parent);
} else {
parentsnap->def->current = true;
if (qemuDomainSnapshotWriteMetadata(vm, parentsnap,
driver->snapshotDir) < 0) {
VIR_WARN("failed to set parent snapshot '%s' as current",
snap->def->parent);
parentsnap->def->current = false;
parentsnap = NULL;
}
}
}
vm->current_snapshot = parentsnap;
}
if (unlink(snapFile) < 0)
VIR_WARN("Failed to unlink %s", snapFile);
virDomainSnapshotObjListRemove(&vm->snapshots, snap);
ret = 0;
cleanup:
VIR_FREE(snapFile);
return ret;
}
struct snap_remove {
struct qemud_driver *driver;
virDomainObjPtr vm;
int err;
bool metadata_only;
bool current;
};
/* Hash iterator callback to discard multiple snapshots. */
static void
qemuDomainSnapshotDiscardAll(void *payload,
const void *name ATTRIBUTE_UNUSED,
void *data)
{
virDomainSnapshotObjPtr snap = payload;
struct snap_remove *curr = data;
int err;
if (snap->def->current)
curr->current = true;
err = qemuDomainSnapshotDiscard(curr->driver, curr->vm, snap, false,
curr->metadata_only);
if (err && !curr->err)
curr->err = err;
}
/* Count how many snapshots in a set have external disk snapshots. */
static void
qemuDomainSnapshotCountExternal(void *payload,
@ -5126,8 +4889,6 @@ qemuDomainUndefineFlags(virDomainPtr dom,
if (!virDomainObjIsActive(vm) &&
(nsnapshots = virDomainSnapshotObjListNum(&vm->snapshots, 0))) {
struct snap_remove rem;
if (!(flags & VIR_DOMAIN_UNDEFINE_SNAPSHOTS_METADATA)) {
qemuReportError(VIR_ERR_OPERATION_INVALID,
_("cannot delete inactive domain with %d "
@ -5135,13 +4896,7 @@ qemuDomainUndefineFlags(virDomainPtr dom,
nsnapshots);
goto cleanup;
}
rem.driver = driver;
rem.vm = vm;
rem.metadata_only = true;
rem.err = 0;
virHashForEach(vm->snapshots.objs, qemuDomainSnapshotDiscardAll, &rem);
if (rem.err < 0)
if (qemuDomainSnapshotDiscardAllMetadata(driver, vm) < 0)
goto cleanup;
}
@ -10132,7 +9887,7 @@ static int qemuDomainSnapshotDelete(virDomainSnapshotPtr snapshot,
int ret = -1;
virDomainSnapshotObjPtr snap = NULL;
char uuidstr[VIR_UUID_STRING_BUFLEN];
struct snap_remove rem;
struct qemu_snap_remove rem;
struct snap_reparent rep;
bool metadata_only = !!(flags & VIR_DOMAIN_SNAPSHOT_DELETE_METADATA_ONLY);
int external = 0;

2
src/qemu/qemu_process.c
View File

@ -106,7 +106,7 @@ qemuProcessRemoveDomainStatus(struct qemud_driver *driver,
extern struct qemud_driver *qemu_driver;
/*
* This is a callback registered with a qemuMonitorPtr instance,
* This is a callback registered with a qemuMonitorPtr instance,
* and to be invoked when the monitor console hits an end of file
* condition, or error, thus indicating VM shutdown should be
* performed