monitor: Fix tracepoint crash on JSON syntax error
[qemu/armbru.git] / qga / vss-win32 / requester.cpp
blob3d9c9716c01c91a0cb7a189ccc7af71a44bf8a46
1 /*
2 * QEMU Guest Agent win32 VSS Requester implementations
4 * Copyright Hitachi Data Systems Corp. 2013
6 * Authors:
7 * Tomoki Sekiyama <tomoki.sekiyama@hds.com>
9 * This work is licensed under the terms of the GNU GPL, version 2 or later.
10 * See the COPYING file in the top-level directory.
13 #include "qemu/osdep.h"
14 #include "vss-common.h"
15 #include "requester.h"
16 #include "install.h"
17 #include <inc/win2003/vswriter.h>
18 #include <inc/win2003/vsbackup.h>
20 /* Max wait time for frozen event (VSS can only hold writes for 10 seconds) */
21 #define VSS_TIMEOUT_FREEZE_MSEC 10000
23 /* Call QueryStatus every 10 ms while waiting for frozen event */
24 #define VSS_TIMEOUT_EVENT_MSEC 10
26 #define err_set(e, err, fmt, ...) \
27 ((e)->error_setg_win32_wrapper((e)->errp, __FILE__, __LINE__, __func__, \
28 err, fmt, ## __VA_ARGS__))
29 /* Bad idea, works only when (e)->errp != NULL: */
30 #define err_is_set(e) ((e)->errp && *(e)->errp)
31 /* To lift this restriction, error_propagate(), like we do in QEMU code */
33 /* Handle to VSSAPI.DLL */
34 static HMODULE hLib;
36 /* Functions in VSSAPI.DLL */
37 typedef HRESULT(STDAPICALLTYPE * t_CreateVssBackupComponents)(
38 OUT IVssBackupComponents**);
39 typedef void(APIENTRY * t_VssFreeSnapshotProperties)(IN VSS_SNAPSHOT_PROP*);
40 static t_CreateVssBackupComponents pCreateVssBackupComponents;
41 static t_VssFreeSnapshotProperties pVssFreeSnapshotProperties;
43 /* Variables used while applications and filesystes are frozen by VSS */
44 static struct QGAVSSContext {
45 IVssBackupComponents *pVssbc; /* VSS requester interface */
46 IVssAsync *pAsyncSnapshot; /* async info of VSS snapshot operation */
47 HANDLE hEventFrozen; /* notify fs/writer freeze from provider */
48 HANDLE hEventThaw; /* request provider to thaw */
49 HANDLE hEventTimeout; /* notify timeout in provider */
50 int cFrozenVols; /* number of frozen volumes */
51 } vss_ctx;
53 STDAPI requester_init(void)
55 COMInitializer initializer; /* to call CoInitializeSecurity */
56 HRESULT hr = CoInitializeSecurity(
57 NULL, -1, NULL, NULL, RPC_C_AUTHN_LEVEL_PKT_PRIVACY,
58 RPC_C_IMP_LEVEL_IDENTIFY, NULL, EOAC_NONE, NULL);
59 if (FAILED(hr)) {
60 fprintf(stderr, "failed to CoInitializeSecurity (error %lx)\n", hr);
61 return hr;
64 hLib = LoadLibraryA("VSSAPI.DLL");
65 if (!hLib) {
66 fprintf(stderr, "failed to load VSSAPI.DLL\n");
67 return HRESULT_FROM_WIN32(GetLastError());
70 pCreateVssBackupComponents = (t_CreateVssBackupComponents)
71 GetProcAddress(hLib,
72 #ifdef _WIN64 /* 64bit environment */
73 "?CreateVssBackupComponents@@YAJPEAPEAVIVssBackupComponents@@@Z"
74 #else /* 32bit environment */
75 "?CreateVssBackupComponents@@YGJPAPAVIVssBackupComponents@@@Z"
76 #endif
78 if (!pCreateVssBackupComponents) {
79 fprintf(stderr, "failed to get proc address from VSSAPI.DLL\n");
80 return HRESULT_FROM_WIN32(GetLastError());
83 pVssFreeSnapshotProperties = (t_VssFreeSnapshotProperties)
84 GetProcAddress(hLib, "VssFreeSnapshotProperties");
85 if (!pVssFreeSnapshotProperties) {
86 fprintf(stderr, "failed to get proc address from VSSAPI.DLL\n");
87 return HRESULT_FROM_WIN32(GetLastError());
90 return S_OK;
93 static void requester_cleanup(void)
95 if (vss_ctx.hEventFrozen) {
96 CloseHandle(vss_ctx.hEventFrozen);
97 vss_ctx.hEventFrozen = NULL;
99 if (vss_ctx.hEventThaw) {
100 CloseHandle(vss_ctx.hEventThaw);
101 vss_ctx.hEventThaw = NULL;
103 if (vss_ctx.hEventTimeout) {
104 CloseHandle(vss_ctx.hEventTimeout);
105 vss_ctx.hEventTimeout = NULL;
107 if (vss_ctx.pAsyncSnapshot) {
108 vss_ctx.pAsyncSnapshot->Release();
109 vss_ctx.pAsyncSnapshot = NULL;
111 if (vss_ctx.pVssbc) {
112 vss_ctx.pVssbc->Release();
113 vss_ctx.pVssbc = NULL;
115 vss_ctx.cFrozenVols = 0;
118 STDAPI requester_deinit(void)
120 requester_cleanup();
122 pCreateVssBackupComponents = NULL;
123 pVssFreeSnapshotProperties = NULL;
124 if (hLib) {
125 FreeLibrary(hLib);
126 hLib = NULL;
129 return S_OK;
132 static HRESULT WaitForAsync(IVssAsync *pAsync)
134 HRESULT ret, hr;
136 do {
137 hr = pAsync->Wait();
138 if (FAILED(hr)) {
139 ret = hr;
140 break;
142 hr = pAsync->QueryStatus(&ret, NULL);
143 if (FAILED(hr)) {
144 ret = hr;
145 break;
147 } while (ret == VSS_S_ASYNC_PENDING);
149 return ret;
152 static void AddComponents(ErrorSet *errset)
154 unsigned int cWriters, i;
155 VSS_ID id, idInstance, idWriter;
156 BSTR bstrWriterName = NULL;
157 VSS_USAGE_TYPE usage;
158 VSS_SOURCE_TYPE source;
159 unsigned int cComponents, c1, c2, j;
160 COMPointer<IVssExamineWriterMetadata> pMetadata;
161 COMPointer<IVssWMComponent> pComponent;
162 PVSSCOMPONENTINFO info;
163 HRESULT hr;
165 hr = vss_ctx.pVssbc->GetWriterMetadataCount(&cWriters);
166 if (FAILED(hr)) {
167 err_set(errset, hr, "failed to get writer metadata count");
168 goto out;
171 for (i = 0; i < cWriters; i++) {
172 hr = vss_ctx.pVssbc->GetWriterMetadata(i, &id, pMetadata.replace());
173 if (FAILED(hr)) {
174 err_set(errset, hr, "failed to get writer metadata of %d/%d",
175 i, cWriters);
176 goto out;
179 hr = pMetadata->GetIdentity(&idInstance, &idWriter,
180 &bstrWriterName, &usage, &source);
181 if (FAILED(hr)) {
182 err_set(errset, hr, "failed to get identity of writer %d/%d",
183 i, cWriters);
184 goto out;
187 hr = pMetadata->GetFileCounts(&c1, &c2, &cComponents);
188 if (FAILED(hr)) {
189 err_set(errset, hr, "failed to get file counts of %S",
190 bstrWriterName);
191 goto out;
194 for (j = 0; j < cComponents; j++) {
195 hr = pMetadata->GetComponent(j, pComponent.replace());
196 if (FAILED(hr)) {
197 err_set(errset, hr,
198 "failed to get component %d/%d of %S",
199 j, cComponents, bstrWriterName);
200 goto out;
203 hr = pComponent->GetComponentInfo(&info);
204 if (FAILED(hr)) {
205 err_set(errset, hr,
206 "failed to get component info %d/%d of %S",
207 j, cComponents, bstrWriterName);
208 goto out;
211 if (info->bSelectable) {
212 hr = vss_ctx.pVssbc->AddComponent(idInstance, idWriter,
213 info->type,
214 info->bstrLogicalPath,
215 info->bstrComponentName);
216 if (FAILED(hr)) {
217 err_set(errset, hr, "failed to add component %S(%S)",
218 info->bstrComponentName, bstrWriterName);
219 goto out;
222 SysFreeString(bstrWriterName);
223 bstrWriterName = NULL;
224 pComponent->FreeComponentInfo(info);
225 info = NULL;
228 out:
229 if (bstrWriterName) {
230 SysFreeString(bstrWriterName);
232 if (pComponent && info) {
233 pComponent->FreeComponentInfo(info);
237 void requester_freeze(int *num_vols, ErrorSet *errset)
239 COMPointer<IVssAsync> pAsync;
240 HANDLE volume;
241 HRESULT hr;
242 LONG ctx;
243 GUID guidSnapshotSet = GUID_NULL;
244 SECURITY_DESCRIPTOR sd;
245 SECURITY_ATTRIBUTES sa;
246 WCHAR short_volume_name[64], *display_name = short_volume_name;
247 DWORD wait_status;
248 int num_fixed_drives = 0, i;
250 if (vss_ctx.pVssbc) { /* already frozen */
251 *num_vols = 0;
252 return;
255 CoInitialize(NULL);
257 /* Allow unrestricted access to events */
258 InitializeSecurityDescriptor(&sd, SECURITY_DESCRIPTOR_REVISION);
259 SetSecurityDescriptorDacl(&sd, TRUE, NULL, FALSE);
260 sa.nLength = sizeof(sa);
261 sa.lpSecurityDescriptor = &sd;
262 sa.bInheritHandle = FALSE;
264 vss_ctx.hEventFrozen = CreateEvent(&sa, TRUE, FALSE, EVENT_NAME_FROZEN);
265 if (!vss_ctx.hEventFrozen) {
266 err_set(errset, GetLastError(), "failed to create event %s",
267 EVENT_NAME_FROZEN);
268 goto out;
270 vss_ctx.hEventThaw = CreateEvent(&sa, TRUE, FALSE, EVENT_NAME_THAW);
271 if (!vss_ctx.hEventThaw) {
272 err_set(errset, GetLastError(), "failed to create event %s",
273 EVENT_NAME_THAW);
274 goto out;
276 vss_ctx.hEventTimeout = CreateEvent(&sa, TRUE, FALSE, EVENT_NAME_TIMEOUT);
277 if (!vss_ctx.hEventTimeout) {
278 err_set(errset, GetLastError(), "failed to create event %s",
279 EVENT_NAME_TIMEOUT);
280 goto out;
283 assert(pCreateVssBackupComponents != NULL);
284 hr = pCreateVssBackupComponents(&vss_ctx.pVssbc);
285 if (FAILED(hr)) {
286 err_set(errset, hr, "failed to create VSS backup components");
287 goto out;
290 hr = vss_ctx.pVssbc->InitializeForBackup();
291 if (FAILED(hr)) {
292 err_set(errset, hr, "failed to initialize for backup");
293 goto out;
296 hr = vss_ctx.pVssbc->SetBackupState(true, true, VSS_BT_FULL, false);
297 if (FAILED(hr)) {
298 err_set(errset, hr, "failed to set backup state");
299 goto out;
303 * Currently writable snapshots are not supported.
304 * To prevent the final commit (which requires to write to snapshots),
305 * ATTR_NO_AUTORECOVERY and ATTR_TRANSPORTABLE are specified here.
307 ctx = VSS_CTX_APP_ROLLBACK | VSS_VOLSNAP_ATTR_TRANSPORTABLE |
308 VSS_VOLSNAP_ATTR_NO_AUTORECOVERY | VSS_VOLSNAP_ATTR_TXF_RECOVERY;
309 hr = vss_ctx.pVssbc->SetContext(ctx);
310 if (hr == (HRESULT)VSS_E_UNSUPPORTED_CONTEXT) {
311 /* Non-server version of Windows doesn't support ATTR_TRANSPORTABLE */
312 ctx &= ~VSS_VOLSNAP_ATTR_TRANSPORTABLE;
313 hr = vss_ctx.pVssbc->SetContext(ctx);
315 if (FAILED(hr)) {
316 err_set(errset, hr, "failed to set backup context");
317 goto out;
320 hr = vss_ctx.pVssbc->GatherWriterMetadata(pAsync.replace());
321 if (SUCCEEDED(hr)) {
322 hr = WaitForAsync(pAsync);
324 if (FAILED(hr)) {
325 err_set(errset, hr, "failed to gather writer metadata");
326 goto out;
329 AddComponents(errset);
330 if (err_is_set(errset)) {
331 goto out;
334 hr = vss_ctx.pVssbc->StartSnapshotSet(&guidSnapshotSet);
335 if (FAILED(hr)) {
336 err_set(errset, hr, "failed to start snapshot set");
337 goto out;
340 volume = FindFirstVolumeW(short_volume_name, sizeof(short_volume_name));
341 if (volume == INVALID_HANDLE_VALUE) {
342 err_set(errset, hr, "failed to find first volume");
343 goto out;
345 for (;;) {
346 if (GetDriveTypeW(short_volume_name) == DRIVE_FIXED) {
347 VSS_ID pid;
348 hr = vss_ctx.pVssbc->AddToSnapshotSet(short_volume_name,
349 g_gProviderId, &pid);
350 if (FAILED(hr)) {
351 WCHAR volume_path_name[PATH_MAX];
352 if (GetVolumePathNamesForVolumeNameW(
353 short_volume_name, volume_path_name,
354 sizeof(volume_path_name), NULL) && *volume_path_name) {
355 display_name = volume_path_name;
357 err_set(errset, hr, "failed to add %S to snapshot set",
358 display_name);
359 FindVolumeClose(volume);
360 goto out;
362 num_fixed_drives++;
364 if (!FindNextVolumeW(volume, short_volume_name,
365 sizeof(short_volume_name))) {
366 FindVolumeClose(volume);
367 break;
371 if (num_fixed_drives == 0) {
372 goto out; /* If there is no fixed drive, just exit. */
375 hr = vss_ctx.pVssbc->PrepareForBackup(pAsync.replace());
376 if (SUCCEEDED(hr)) {
377 hr = WaitForAsync(pAsync);
379 if (FAILED(hr)) {
380 err_set(errset, hr, "failed to prepare for backup");
381 goto out;
384 hr = vss_ctx.pVssbc->GatherWriterStatus(pAsync.replace());
385 if (SUCCEEDED(hr)) {
386 hr = WaitForAsync(pAsync);
388 if (FAILED(hr)) {
389 err_set(errset, hr, "failed to gather writer status");
390 goto out;
394 * Start VSS quiescing operations.
395 * CQGAVssProvider::CommitSnapshots will kick vss_ctx.hEventFrozen
396 * after the applications and filesystems are frozen.
398 hr = vss_ctx.pVssbc->DoSnapshotSet(&vss_ctx.pAsyncSnapshot);
399 if (FAILED(hr)) {
400 err_set(errset, hr, "failed to do snapshot set");
401 goto out;
404 /* Need to call QueryStatus several times to make VSS provider progress */
405 for (i = 0; i < VSS_TIMEOUT_FREEZE_MSEC/VSS_TIMEOUT_EVENT_MSEC; i++) {
406 HRESULT hr2 = vss_ctx.pAsyncSnapshot->QueryStatus(&hr, NULL);
407 if (FAILED(hr2)) {
408 err_set(errset, hr, "failed to do snapshot set");
409 goto out;
411 if (hr != VSS_S_ASYNC_PENDING) {
412 err_set(errset, E_FAIL,
413 "DoSnapshotSet exited without Frozen event");
414 goto out;
416 wait_status = WaitForSingleObject(vss_ctx.hEventFrozen,
417 VSS_TIMEOUT_EVENT_MSEC);
418 if (wait_status != WAIT_TIMEOUT) {
419 break;
423 if (wait_status == WAIT_TIMEOUT) {
424 err_set(errset, E_FAIL,
425 "timeout when try to receive Frozen event from VSS provider");
426 /* If we are here, VSS had timeout.
427 * Don't call AbortBackup, just return directly.
429 goto out1;
432 if (wait_status != WAIT_OBJECT_0) {
433 err_set(errset, E_FAIL,
434 "couldn't receive Frozen event from VSS provider");
435 goto out;
438 *num_vols = vss_ctx.cFrozenVols = num_fixed_drives;
439 return;
441 out:
442 if (vss_ctx.pVssbc) {
443 vss_ctx.pVssbc->AbortBackup();
446 out1:
447 requester_cleanup();
448 CoUninitialize();
452 void requester_thaw(int *num_vols, ErrorSet *errset)
454 COMPointer<IVssAsync> pAsync;
456 if (!vss_ctx.hEventThaw) {
458 * In this case, DoSnapshotSet is aborted or not started,
459 * and no volumes must be frozen. We return without an error.
461 *num_vols = 0;
462 return;
465 /* Tell the provider that the snapshot is finished. */
466 SetEvent(vss_ctx.hEventThaw);
468 assert(vss_ctx.pVssbc);
469 assert(vss_ctx.pAsyncSnapshot);
471 HRESULT hr = WaitForAsync(vss_ctx.pAsyncSnapshot);
472 switch (hr) {
473 case VSS_S_ASYNC_FINISHED:
474 hr = vss_ctx.pVssbc->BackupComplete(pAsync.replace());
475 if (SUCCEEDED(hr)) {
476 hr = WaitForAsync(pAsync);
478 if (FAILED(hr)) {
479 err_set(errset, hr, "failed to complete backup");
481 break;
483 case (HRESULT)VSS_E_OBJECT_NOT_FOUND:
485 * On Windows earlier than 2008 SP2 which does not support
486 * VSS_VOLSNAP_ATTR_NO_AUTORECOVERY context, the final commit is not
487 * skipped and VSS is aborted by VSS_E_OBJECT_NOT_FOUND. However, as
488 * the system had been frozen until fsfreeze-thaw command was issued,
489 * we ignore this error.
491 vss_ctx.pVssbc->AbortBackup();
492 break;
494 case VSS_E_UNEXPECTED_PROVIDER_ERROR:
495 if (WaitForSingleObject(vss_ctx.hEventTimeout, 0) != WAIT_OBJECT_0) {
496 err_set(errset, hr, "unexpected error in VSS provider");
497 break;
499 /* fall through if hEventTimeout is signaled */
501 case (HRESULT)VSS_E_HOLD_WRITES_TIMEOUT:
502 err_set(errset, hr, "couldn't hold writes: "
503 "fsfreeze is limited up to 10 seconds");
504 break;
506 default:
507 err_set(errset, hr, "failed to do snapshot set");
510 if (err_is_set(errset)) {
511 vss_ctx.pVssbc->AbortBackup();
513 *num_vols = vss_ctx.cFrozenVols;
514 requester_cleanup();
516 CoUninitialize();
517 StopService();