[Qemu-devel] [resend][PATCH] qga-win: add support for qmp_guest_fsfreeze_freeze_list

[Chen Hanxiao]

From: Chen Hanxiao <address@hidden>

This patch add support for freeze specified fs.

The valid mountpoints list member are [1]:

  The path of a mounted folder, for example, Y:\MountX\
  A drive letter, for example, D:\
  A volume GUID path of the form \\?\Volume{GUID}\,
      where GUID identifies the volume
  A UNC path that specifies a remote file share,
      for example, \\Clusterx\Share1\

[1] 
https://docs.microsoft.com/en-us/windows/desktop/api/vsbackup/nf-vsbackup-ivssbackupcomponents-addtosnapshotset

Cc: Michael Roth <address@hidden>
Signed-off-by: Chen Hanxiao <address@hidden>
---
 qga/commands-win32.c        | 21 ++++++--------
 qga/main.c                  |  2 +-
 qga/vss-win32.c             |  5 ++--
 qga/vss-win32.h             |  3 +-
 qga/vss-win32/requester.cpp | 56 +++++++++++++++++++++++++++++++------
 qga/vss-win32/requester.h   | 13 +++++++--
 6 files changed, 72 insertions(+), 28 deletions(-)

diff --git a/qga/commands-win32.c b/qga/commands-win32.c
index 98d9735389..1d627f73c1 100644
--- a/qga/commands-win32.c
+++ b/qga/commands-win32.c
@@ -776,6 +776,13 @@ GuestFsfreezeStatus qmp_guest_fsfreeze_status(Error **errp)
  * The frozen state is limited for up to 10 seconds by VSS.
  */
 int64_t qmp_guest_fsfreeze_freeze(Error **errp)
+{
+    return qmp_guest_fsfreeze_freeze_list(false, NULL, errp);
+}
+
+int64_t qmp_guest_fsfreeze_freeze_list(bool has_mountpoints,
+                                       strList *mountpoints,
+                                       Error **errp)
 {
     int i;
     Error *local_err = NULL;
@@ -790,7 +797,7 @@ int64_t qmp_guest_fsfreeze_freeze(Error **errp)
     /* cannot risk guest agent blocking itself on a write in this state */
     ga_set_frozen(ga_state);
 
-    qga_vss_fsfreeze(&i, true, &local_err);
+    qga_vss_fsfreeze(&i, true, mountpoints, &local_err);
     if (local_err) {
         error_propagate(errp, local_err);
         goto error;
@@ -808,15 +815,6 @@ error:
     return 0;
 }
 
-int64_t qmp_guest_fsfreeze_freeze_list(bool has_mountpoints,
-                                       strList *mountpoints,
-                                       Error **errp)
-{
-    error_setg(errp, QERR_UNSUPPORTED);
-
-    return 0;
-}
-
 /*
  * Thaw local file systems using Volume Shadow-copy Service.
  */
@@ -829,7 +827,7 @@ int64_t qmp_guest_fsfreeze_thaw(Error **errp)
         return 0;
     }
 
-    qga_vss_fsfreeze(&i, false, errp);
+    qga_vss_fsfreeze(&i, false, NULL, errp);
 
     ga_unset_frozen(ga_state);
     return i;
@@ -1646,7 +1644,6 @@ GList *ga_command_blacklist_init(GList *blacklist)
         "guest-set-vcpus",
         "guest-get-memory-blocks", "guest-set-memory-blocks",
         "guest-get-memory-block-size",
-        "guest-fsfreeze-freeze-list",
         NULL};
     char **p = (char **)list_unsupported;
 
diff --git a/qga/main.c b/qga/main.c
index 87372d40ef..098c783f1f 100644
--- a/qga/main.c
+++ b/qga/main.c
@@ -152,7 +152,7 @@ static void quit_handler(int sig)
             WaitForSingleObject(hEventTimeout, 0);
             CloseHandle(hEventTimeout);
         }
-        qga_vss_fsfreeze(&i, false, &err);
+        qga_vss_fsfreeze(&i, false, NULL, &err);
         if (err) {
             g_debug("Error unfreezing filesystems prior to exiting: %s",
                 error_get_pretty(err));
diff --git a/qga/vss-win32.c b/qga/vss-win32.c
index a541f3ae01..f444a25a70 100644
--- a/qga/vss-win32.c
+++ b/qga/vss-win32.c
@@ -147,7 +147,8 @@ void ga_uninstall_vss_provider(void)
 }
 
 /* Call VSS requester and freeze/thaw filesystems and applications */
-void qga_vss_fsfreeze(int *nr_volume, bool freeze, Error **errp)
+void qga_vss_fsfreeze(int *nr_volume, bool freeze,
+                      strList *mountpoints, Error **errp)
 {
     const char *func_name = freeze ? "requester_freeze" : "requester_thaw";
     QGAVSSRequesterFunc func;
@@ -164,5 +165,5 @@ void qga_vss_fsfreeze(int *nr_volume, bool freeze, Error 
**errp)
         return;
     }
 
-    func(nr_volume, &errset);
+    func(nr_volume, mountpoints, &errset);
 }
diff --git a/qga/vss-win32.h b/qga/vss-win32.h
index 4f8e39aa5c..ce2abe5a72 100644
--- a/qga/vss-win32.h
+++ b/qga/vss-win32.h
@@ -22,6 +22,7 @@ bool vss_initialized(void);
 int ga_install_vss_provider(void);
 void ga_uninstall_vss_provider(void);
 
-void qga_vss_fsfreeze(int *nr_volume, bool freeze, Error **errp);
+void qga_vss_fsfreeze(int *nr_volume, bool freeze,
+                      strList *mountpints, Error **errp);
 
 #endif
diff --git a/qga/vss-win32/requester.cpp b/qga/vss-win32/requester.cpp
index 3d9c9716c0..0bd170eddc 100644
--- a/qga/vss-win32/requester.cpp
+++ b/qga/vss-win32/requester.cpp
@@ -234,7 +234,7 @@ out:
     }
 }
 
-void requester_freeze(int *num_vols, ErrorSet *errset)
+void requester_freeze(int *num_vols, void *mountpoints, ErrorSet *errset)
 {
     COMPointer<IVssAsync> pAsync;
     HANDLE volume;
@@ -245,7 +245,9 @@ void requester_freeze(int *num_vols, ErrorSet *errset)
     SECURITY_ATTRIBUTES sa;
     WCHAR short_volume_name[64], *display_name = short_volume_name;
     DWORD wait_status;
+    PWCHAR WStr = NULL;
     int num_fixed_drives = 0, i;
+    int num_mount_points = 0;
 
     if (vss_ctx.pVssbc) { /* already frozen */
         *num_vols = 0;
@@ -337,12 +339,42 @@ void requester_freeze(int *num_vols, ErrorSet *errset)
         goto out;
     }
 
-    volume = FindFirstVolumeW(short_volume_name, sizeof(short_volume_name));
-    if (volume == INVALID_HANDLE_VALUE) {
-        err_set(errset, hr, "failed to find first volume");
+    if (mountpoints) {
+        for (volList *list = (volList *)mountpoints; list; list = list->next) {
+            size_t len = strlen(list->value) + 1;
+            size_t converted = 0;
+            VSS_ID pid;
+
+            WStr = new wchar_t[len];
+            mbstowcs_s(&converted, WStr, len, list->value, _TRUNCATE);
+
+            hr = vss_ctx.pVssbc->AddToSnapshotSet(WStr,
+                                                  g_gProviderId, &pid);
+            if (FAILED(hr)) {
+                err_set(errset, hr, "failed to add %S to snapshot set", WStr);
+                goto out;
+            }
+            num_mount_points++;
+
+            delete WStr;
+        }
+    }
+
+    if (mountpoints && num_mount_points == 0) {
+        /* If there is no valid mount points, just exit. */
         goto out;
     }
-    for (;;) {
+
+
+    if (!mountpoints) {
+        volume = FindFirstVolumeW(short_volume_name, 
sizeof(short_volume_name));
+        if (volume == INVALID_HANDLE_VALUE) {
+            err_set(errset, hr, "failed to find first volume");
+            goto out;
+        }
+    }
+
+    while (!mountpoints) {
         if (GetDriveTypeW(short_volume_name) == DRIVE_FIXED) {
             VSS_ID pid;
             hr = vss_ctx.pVssbc->AddToSnapshotSet(short_volume_name,
@@ -355,7 +387,7 @@ void requester_freeze(int *num_vols, ErrorSet *errset)
                     display_name = volume_path_name;
                 }
                 err_set(errset, hr, "failed to add %S to snapshot set",
-                                 display_name);
+                        display_name);
                 FindVolumeClose(volume);
                 goto out;
             }
@@ -368,7 +400,7 @@ void requester_freeze(int *num_vols, ErrorSet *errset)
         }
     }
 
-    if (num_fixed_drives == 0) {
+    if (!mountpoints && num_fixed_drives == 0) {
         goto out; /* If there is no fixed drive, just exit. */
     }
 
@@ -435,13 +467,19 @@ void requester_freeze(int *num_vols, ErrorSet *errset)
         goto out;
     }
 
-    *num_vols = vss_ctx.cFrozenVols = num_fixed_drives;
+    if (mountpoints) {
+        *num_vols = vss_ctx.cFrozenVols = num_mount_points;
+    } else {
+        *num_vols = vss_ctx.cFrozenVols = num_fixed_drives;
+    }
+
     return;
 
 out:
     if (vss_ctx.pVssbc) {
         vss_ctx.pVssbc->AbortBackup();
     }
+    delete WStr;
 
 out1:
     requester_cleanup();
@@ -449,7 +487,7 @@ out1:
 }
 
 
-void requester_thaw(int *num_vols, ErrorSet *errset)
+void requester_thaw(int *num_vols, void *mountpints, ErrorSet *errset)
 {
     COMPointer<IVssAsync> pAsync;
 
diff --git a/qga/vss-win32/requester.h b/qga/vss-win32/requester.h
index 2a39d734a2..5a8e8faf0c 100644
--- a/qga/vss-win32/requester.h
+++ b/qga/vss-win32/requester.h
@@ -34,9 +34,16 @@ typedef struct ErrorSet {
 STDAPI requester_init(void);
 STDAPI requester_deinit(void);
 
-typedef void (*QGAVSSRequesterFunc)(int *, ErrorSet *);
-void requester_freeze(int *num_vols, ErrorSet *errset);
-void requester_thaw(int *num_vols, ErrorSet *errset);
+typedef struct volList volList;
+
+struct volList {
+    volList *next;
+    char *value;
+};
+
+typedef void (*QGAVSSRequesterFunc)(int *, void *, ErrorSet *);
+void requester_freeze(int *num_vols, void *volList, ErrorSet *errset);
+void requester_thaw(int *num_vols, void *volList, ErrorSet *errset);
 
 #ifdef __cplusplus
 }
-- 
2.17.1