qga-win: fix "guest-get-fsinfo" wrong filesystem type

This patch handles the case where unmounted volumes exist,
where in that case GetVolumePathNamesForVolumeName returns
empty path, GetVolumeInformation will use the current working
directory instead.
This patch fixes the issue by opening a handle to the volumes,
and using GetVolumeInformationByHandleW instead.

Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1746667
Signed-off-by: Basil Salman <bsalman@redhat.com>
Signed-off-by: Basil Salman <basil@daynix.com>
*fix crash when guest_build_fsinfo() sets errp multiple times
*make new error message more distinct from existing ones
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

diff --git a/qga/commands-win32.c b/qga/commands-win32.c
index aaa71f147b0002d362a3d903044affc738c2b9df..15c9d7944b8e5fd7092ad5b54273dd3a9a234e8f 100644 (file)
--- a/qga/commands-win32.c
+++ b/qga/commands-win32.c
@@ -958,11 +958,13 @@ static GuestFilesystemInfo *build_guest_fsinfo(char *guid, Error **errp)
 {
     DWORD info_size;
     char mnt, *mnt_point;
+    wchar_t wfs_name[32];
     char fs_name[32];
-    char vol_info[MAX_PATH+1];
+    wchar_t vol_info[MAX_PATH + 1];
     size_t len;
     uint64_t i64FreeBytesToCaller, i64TotalBytes, i64FreeBytes;
     GuestFilesystemInfo *fs = NULL;
+    HANDLE hLocalDiskHandle = NULL;
 
     GetVolumePathNamesForVolumeName(guid, (LPCH)&mnt, 0, &info_size);
     if (GetLastError() != ERROR_MORE_DATA) {
@@ -977,18 +979,27 @@ static GuestFilesystemInfo *build_guest_fsinfo(char *guid, Error **errp)
         goto free;
     }
 
+    hLocalDiskHandle = CreateFile(guid, 0 , 0, NULL, OPEN_EXISTING,
+                                  FILE_ATTRIBUTE_NORMAL |
+                                  FILE_FLAG_BACKUP_SEMANTICS, NULL);
+    if (INVALID_HANDLE_VALUE == hLocalDiskHandle) {
+        error_setg_win32(errp, GetLastError(), "failed to get handle for volume");
+        goto free;
+    }
+
     len = strlen(mnt_point);
     mnt_point[len] = '\\';
     mnt_point[len+1] = 0;
-    if (!GetVolumeInformation(mnt_point, vol_info, sizeof(vol_info), NULL, NULL,
-                              NULL, (LPSTR)&fs_name, sizeof(fs_name))) {
+
+    if (!GetVolumeInformationByHandleW(hLocalDiskHandle, vol_info,
+                                       sizeof(vol_info), NULL, NULL, NULL,
+                                       (LPWSTR) & wfs_name, sizeof(wfs_name))) {
         if (GetLastError() != ERROR_NOT_READY) {
             error_setg_win32(errp, GetLastError(), "failed to get volume info");
         }
         goto free;
     }
 
-    fs_name[sizeof(fs_name) - 1] = 0;
     fs = g_malloc(sizeof(*fs));
     fs->name = g_strdup(guid);
     fs->has_total_bytes = false;
@@ -1007,9 +1018,11 @@ static GuestFilesystemInfo *build_guest_fsinfo(char *guid, Error **errp)
             fs->has_used_bytes = true;
         }
     }
+    wcstombs(fs_name, wfs_name, sizeof(wfs_name));
     fs->type = g_strdup(fs_name);
     fs->disk = build_guest_disk_info(guid, errp);
 free:
+    CloseHandle(hLocalDiskHandle);
     g_free(mnt_point);
     return fs;
 }
@@ -1027,8 +1040,12 @@ GuestFilesystemInfoList *qmp_guest_get_fsinfo(Error **errp)
     }
 
     do {
-        GuestFilesystemInfo *info = build_guest_fsinfo(guid, errp);
-        if (info == NULL) {
+        Error *local_err = NULL;
+        GuestFilesystemInfo *info = build_guest_fsinfo(guid, &local_err);
+        if (local_err) {
+            g_debug("failed to get filesystem info, ignoring error: %s",
+                    error_get_pretty(local_err));
+            error_free(local_err);
             continue;
         }
         new = g_malloc(sizeof(*ret));