!1751 fix umount bug

Merge pull request !1751 from nianyuu/master

modules/module_engine/include/appspawn_hook.h

@@ -60,6 +60,7 @@ typedef enum TagAppSpawnHookStage {
     // 应用状态处理
     STAGE_SERVER_APP_ADD,
     STAGE_SERVER_APP_DIED,
+    STAGE_SERVER_APP_UMOUNT,
     // run before fork
     STAGE_PARENT_PRE_FORK = 20,
     STAGE_PARENT_POST_FORK = 21,

modules/modulemgr/appspawn_modulemgr.c

@@ -259,7 +259,7 @@ int ProcessMgrHookExecute(AppSpawnHookStage stage, const AppSpawnContent *conten
 {
     APPSPAWN_CHECK(content != NULL && appInfo != NULL,
         return APPSPAWN_ARG_INVALID, "Invalid hook");
-    APPSPAWN_CHECK((stage >= STAGE_SERVER_APP_ADD) && (stage <= STAGE_SERVER_APP_DIED),
+    APPSPAWN_CHECK((stage >= STAGE_SERVER_APP_ADD) && (stage <= STAGE_SERVER_APP_UMOUNT),
         return APPSPAWN_ARG_INVALID, "Invalid stage %{public}d", (int)stage);
 
     AppSpawnAppArg arg;
@@ -279,7 +279,7 @@ static int ProcessMgrHookRun(const HOOK_INFO *hookInfo, void *executionContext)
 int AddProcessMgrHook(AppSpawnHookStage stage, int prio, ProcessChangeHook hook)
 {
     APPSPAWN_CHECK(hook != NULL, return APPSPAWN_ARG_INVALID, "Invalid hook");
-    APPSPAWN_CHECK((stage >= STAGE_SERVER_APP_ADD) && (stage <= STAGE_SERVER_APP_DIED),
+    APPSPAWN_CHECK((stage >= STAGE_SERVER_APP_ADD) && (stage <= STAGE_SERVER_APP_UMOUNT),
         return APPSPAWN_ARG_INVALID, "Invalid stage %{public}d", (int)stage);
     HOOK_INFO info;
     info.stage = stage;

modules/sandbox/sandbox_utils.cpp

@@ -57,6 +57,8 @@
 using namespace std;
 using namespace OHOS;
 
+static map<string, int> g_mountInfo;
+
 namespace OHOS {
 namespace AppSpawn {
 namespace {
@@ -1821,6 +1823,8 @@ int32_t SetAppSandboxProperty(AppSpawnMgr *content, AppSpawningCtx *property)
 {
     APPSPAWN_CHECK(property != nullptr, return -1, "Invalid appspwn client");
     APPSPAWN_CHECK(content != nullptr, return -1, "Invalid appspwn content");
+    // clear g_mountInfo in the child process
+    g_mountInfo.clear();
     int ret = 0;
     // no sandbox
     if (CheckAppMsgFlagsSet(property, APP_FLAGS_NO_SANDBOX)) {
@@ -1899,6 +1903,9 @@ static void MountDir(const AppSpawningCtx *property, const char *rootPath, const
     int len = sprintf_s(path, allPathSize, "%s%u/%s%s", rootPath, info->uid / userIdBase, bundleName, targetPath);
     APPSPAWN_CHECK(len > 0 && ((size_t)len < allPathSize), free(path);
         return, "Failed to get sandbox path");
+    if (srcPath != nullptr) {
+        g_mountInfo[string(bundleName)]++;
+    }
 
     if (access(path, F_OK) == 0 && srcPath == nullptr) {
         free(path);
@@ -2120,6 +2127,49 @@ static int SpawnMountDirToShared(AppSpawnMgr *content, AppSpawningCtx *property)
     return 0;
 }
 
+static void UmountDir(const char *rootPath, const char *targetPath, const AppSpawnedProcessInfo *appInfo)
+{
+    size_t allPathSize = strlen(rootPath) + USER_ID_SIZE + strlen(appInfo->name) + strlen(targetPath) + 2;
+    char *path = reinterpret_cast<char *>(malloc(sizeof(char) * (allPathSize)));
+    APPSPAWN_CHECK(path != NULL, return, "Failed to malloc path");
+
+    int ret = sprintf_s(path, allPathSize, "%s%u/%s%s", rootPath, appInfo->uid / UID_BASE,
+        appInfo->name, targetPath);
+    APPSPAWN_CHECK(ret > 0 && ((size_t)ret < allPathSize), free(path);
+        return, "Failed to get sandbox path errno %{public}d", errno);
+
+    ret = umount2(path, MNT_DETACH);
+    if (ret == 0) {
+        APPSPAWN_LOGV("Umount2 sandbox path %{public}s success", path);
+    } else {
+        APPSPAWN_LOGW("Failed to umount2 sandbox path %{public}s errno %{public}d", path, errno);
+    }
+    free(path);
+}
+
+static int UmountSandboxPath(const AppSpawnMgr *content, const AppSpawnedProcessInfo *appInfo)
+{
+    APPSPAWN_CHECK(content != NULL && appInfo != NULL && appInfo->name != NULL,
+        return -1, "Invalid content or appInfo");
+    APPSPAWN_LOGV("UmountSandboxPath name %{public}s pid %{public}d", appInfo->name, appInfo->pid);
+    const char rootPath[] = "/mnt/sandbox/";
+    const char el1Path[] = "/data/storage/el1/bundle";
+
+    if (g_mountInfo.find(string(appInfo->name)) == g_mountInfo.end()) {
+        return 0;
+    }
+    g_mountInfo[string(appInfo->name)]--;
+    if (g_mountInfo[string(appInfo->name)] == 0) {
+        APPSPAWN_LOGV("no app %{public}s use it, need umount", appInfo->name);
+        g_mountInfo.erase(string(appInfo->name));
+        UmountDir(rootPath, el1Path, appInfo);
+    } else {
+        APPSPAWN_LOGV("app %{public}s use it mount times %{public}d, not need umount",
+            appInfo->name, g_mountInfo[string(appInfo->name)]);
+    }
+    return 0;
+}
+
 #ifndef APPSPAWN_SANDBOX_NEW
 MODULE_CONSTRUCTOR(void)
 {
@@ -2127,5 +2177,6 @@ MODULE_CONSTRUCTOR(void)
     (void)AddServerStageHook(STAGE_SERVER_PRELOAD, HOOK_PRIO_SANDBOX, LoadAppSandboxConfig);
     (void)AddAppSpawnHook(STAGE_PARENT_PRE_FORK, HOOK_PRIO_COMMON, SpawnMountDirToShared);
     (void)AddAppSpawnHook(STAGE_CHILD_EXECUTE, HOOK_PRIO_SANDBOX, SetAppSandboxProperty);
+    (void)AddProcessMgrHook(STAGE_SERVER_APP_UMOUNT, HOOK_PRIO_SANDBOX, UmountSandboxPath);
 }
 #endif

standard/appspawn_service.c

@@ -155,6 +155,7 @@ static void HandleDiedPid(pid_t pid, uid_t uid, int status)
     APPSPAWN_CHECK_ONLY_LOG(appInfo->uid == uid, "Invalid uid %{public}u %{public}u", appInfo->uid, uid);
     DumpStatus(appInfo->name, pid, status);
     ProcessMgrHookExecute(STAGE_SERVER_APP_DIED, GetAppSpawnContent(), appInfo);
+    ProcessMgrHookExecute(STAGE_SERVER_APP_UMOUNT, GetAppSpawnContent(), appInfo);
 
     // if current process of death is nwebspawn, restart appspawn
     if (strcmp(appInfo->name, NWEBSPAWN_SERVER_NAME) == 0) {