轉自http://blog.csdn.net/yangwen123/article/details/8919503
1.Vold (Volume Daemon)介紹
vold進程接收來自內核的外部設備消息,用於管理和控制Android平臺外部存儲設備,包括SD插撥、掛載、卸載、格式化等;當外部設備發生變化時,內核通過Netlink發送uEvent格式的消息給用戶空間程序,Netlink 是一種基於異步通信機制,在內核與用戶應用間進行雙向數據傳輸的特殊 socket,用戶態應用使用標準的socket API 就可以使用 netlink 提供的強大功能;
2.Vold 框架設計
1.Netlink介紹
2.Uevent介紹
3.Vold 源碼分析
- int main()
- {
- VolumeManager *vm;
- CommandListener *cl;
- NetlinkManager *nm;
- //創建vold設備文件夾
- mkdir("/dev/block/vold", 0755);
- //初始化Vold相關的類實例 single
- vm = VolumeManager::Instance();
- nm = NetlinkManager::Instance();
- //CommandListener 創建vold socket監聽上層消息
- cl = new CommandListener();
- vm->setBroadcaster((SocketListener *) cl);
- nm->setBroadcaster((SocketListener *) cl);
- //啓動VolumeManager
- vm->start();
- //根據配置文件/etc/vold.fstab 初始化VolumeManager
- process_config(vm);
- //啓動NetlinkManager socket監聽內核發送uevent
- nm->start();
- //向/sys/block/目錄下所有設備uevent文件寫入“add\n”,
- //觸發內核sysfs發送uevent消息
- coldboot("/sys/block");
- //啓動CommandListener監聽vold socket
- cl->startListener();
- // Eventually we'll become the monitoring thread
- while(1) {
- sleep(1000);
- }
- exit(0);
- }
- <span style="font-family:Verdana, Arial, Helvetica, sans-serif;font-size:18px;"><span style="line-height: 24px; background-color: rgb(254, 254, 242);">#######################
- ## Regular device mount
- ##
- ## Format: dev_mount <label> <mount_point> <part> <sysfs_path1...>
- ## label - Label for the volume
- ## mount_point - Where the volume will be mounted
- ## part - Partition # (1 based), or 'auto' for first usable partition.
- ## <sysfs_path> - List of sysfs paths to source devices
- ######################
- # Mounts the first usable partition of the specified device
- #dev_mount sdcard /mnt/sdcard auto /block/mmcblk0
- dev_mount internal /mnt/sdcard 19 /devices/platform/sprd-sdhci.3/mmc_host/mmc3
- dev_mount sdcard /mnt/sdcard/external auto /devices/platform/sprd-sdhci.0/mmc_host/mmc0</span></span>
- static int process_config(VolumeManager *vm) {
- //打開vold.fstab的配置文件
- fp = fopen("/etc/vold.fstab", "r")
- //解析vold.fstab 配置存儲設備的掛載點
- while(fgets(line, sizeof(line), fp)) {
- const char *delim = " \t";
- char *type, *label, *mount_point, *part, *mount_flags, *sysfs_path;
- type = strtok_r(line, delim, &save_ptr)
- label = strtok_r(NULL, delim, &save_ptr)
- mount_point = strtok_r(NULL, delim, &save_ptr)
- //判斷分區 auto沒有分區
- part = strtok_r(NULL, delim, &save_ptr)
- if (!strcmp(part, "auto")) {
- //創建DirectVolume對象 相關的掛載點設備的操作
- dv = new DirectVolume(vm, label, mount_point, -1);
- } else {
- dv = new DirectVolume(vm, label, mount_point, atoi(part));
- }
- //添加掛載點設備路徑
- while ((sysfs_path = strtok_r(NULL, delim, &save_ptr))) {
- dv->addPath(sysfs_path)
- }
- //將DirectVolume 添加到VolumeManager管理
- vm->addVolume(dv);
- }
- fclose(fp);
- return 0;
- }
4.Vold各模塊分析
1.NetlinkManager模塊
1)構造NetlinkManager實例:nm = NetlinkManager::Instance()
2)設置事件廣播監聽:nm->setBroadcaster((SocketListener *) cl)
3)啓動NetlinkManager:nm->start()
構造NetlinkManager實例
- NetlinkManager *NetlinkManager::Instance() {
- if (!sInstance) //採用單例模式創建NetlinkManager實例
- sInstance = new NetlinkManager();
- return sInstance;
- }
啓動NetlinkManager
- int NetlinkManager::start() {
- //netlink使用的socket結構
- struct sockaddr_nl nladdr;
- //初始化socket數據結構
- memset(&nladdr, 0, sizeof(nladdr));
- nladdr.nl_family = AF_NETLINK;
- nladdr.nl_pid = getpid();
- nladdr.nl_groups = 0xffffffff;
- //創建socket PF_NETLINK類型
- mSock = socket(PF_NETLINK,SOCK_DGRAM,NETLINK_KOBJECT_UEVENT);
- //配置socket 大小
- setsockopt(mSock, SOL_SOCKET, SO_RCVBUFFORCE, &sz, sizeof(sz);
- setsockopt(mSock, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on);
- //bindsocket地址
- bind(mSock, (struct sockaddr *) &nladdr, sizeof(nladdr);
- //創建NetlinkHandler 傳遞socket標識,並啓動
- mHandler = new NetlinkHandler(mSock);
- mHandler->start();
- return 0;
- }
- SocketListener::SocketListener(int socketFd, bool listen) {
- init(NULL, socketFd, listen, false);
- }
- void SocketListener::init(const char *socketName, int socketFd, bool listen, bool useCmdNum) {
- mListen = listen;
- mSocketName = socketName;
- mSock = socketFd;
- mUseCmdNum = useCmdNum;
- pthread_mutex_init(&mClientsLock, NULL);
- mClients = new SocketClientCollection();
- }
- NetlinkListener::NetlinkListener(int socket) :
- SocketListener(socket, false) {
- mFormat = NETLINK_FORMAT_ASCII;
- }
- NetlinkHandler::NetlinkHandler(int listenerSocket) :
- NetlinkListener(listenerSocket) {
- }
- int NetlinkHandler::start() {
- //父類startListener
- return this->startListener();
- }
- int SocketListener::startListener() {
- //NetlinkHandler mListen爲false
- if (mListen && listen(mSock, 4) < 0) {
- return -1;
- } else if (!mListen){
- //mListen爲false 用於netlink消息監聽
- //創建SocketClient作爲SocketListener 的客戶端
- mClients->push_back(new SocketClient(mSock, false, mUseCmdNum));
- }
- //創建匿名管道
- pipe(mCtrlPipe);
- //創建線程執行函數threadStart 參this
- pthread_create(&mThread, NULL, SocketListener::threadStart, this);
- }
uevent消息監聽線程
啓動NetlinkHandler過程通過創建一個SocketListener工作線程來監聽Kernel netlink發送的UEvent消息,該線程完成的工作:- void *SocketListener::threadStart(void *obj) {
- //參數轉換
- SocketListener *me = reinterpret_cast<SocketListener *>(obj);
- me->runListener();
- pthread_exit(NULL);
- return NULL;
- }
- void SocketListener::runListener() {
- //SocketClient List
- SocketClientCollection *pendingList = new SocketClientCollection();
- while(1) {
- fd_set read_fds;
- //mListen 爲false
- if (mListen) {
- max = mSock;
- FD_SET(mSock, &read_fds);
- }
- //加入一組文件描述符集合 選擇fd最大的max
- FD_SET(mCtrlPipe[0], &read_fds);
- pthread_mutex_lock(&mClientsLock);
- for (it = mClients->begin(); it != mClients->end(); ++it) {
- int fd = (*it)->getSocket();
- FD_SET(fd, &read_fds);
- if (fd > max)
- max = fd;
- }
- pthread_mutex_unlock(&mClientsLock);
- //監聽文件描述符是否變化
- rc = select(max + 1, &read_fds, NULL, NULL, NULL);
- //匿名管道被寫,退出線程
- if (FD_ISSET(mCtrlPipe[0], &read_fds))
- break;
- //mListen 爲false
- if (mListen && FD_ISSET(mSock, &read_fds)) {
- //mListen 爲ture 表示正常監聽socket
- struct sockaddr addr;
- do {
- //接收客戶端連接
- c = accept(mSock, &addr, &alen);
- } while (c < 0 && errno == EINTR);
- //此處創建一個客戶端SocketClient加入mClients列表中,異步延遲處理
- pthread_mutex_lock(&mClientsLock);
- mClients->push_back(new SocketClient(c, true, mUseCmdNum));
- pthread_mutex_unlock(&mClientsLock);
- }
- /* Add all active clients to the pending list first */
- pendingList->clear();
- //將所有有消息的Client加入到pendingList中
- pthread_mutex_lock(&mClientsLock);
- for (it = mClients->begin(); it != mClients->end(); ++it) {
- int fd = (*it)->getSocket();
- if (FD_ISSET(fd, &read_fds)) {
- pendingList->push_back(*it);
- }
- }
- pthread_mutex_unlock(&mClientsLock);
- //處理所有消息
- while (!pendingList->empty()) {
- it = pendingList->begin();
- SocketClient* c = *it;
- pendingList->erase(it);
- //處理有數據發送的socket 虛函數
- if (!onDataAvailable(c) && mListen) {
- //mListen爲false
- }
- }
- }
- }
- bool NetlinkListener::onDataAvailable(SocketClient *cli)
- {
- //獲取socket id
- int socket = cli->getSocket();
- //接收netlink uevent消息
- count = TEMP_FAILURE_RETRY(uevent_kernel_multicast_uid_recv(
- socket, mBuffer, sizeof(mBuffer), &uid));
- //解析uevent消息爲NetlinkEvent消息
- NetlinkEvent *evt = new NetlinkEvent();
- evt->decode(mBuffer, count, mFormat);
- //處理NetlinkEvent onEvent虛函數
- onEvent(evt);
- }
- void NetlinkHandler::onEvent(NetlinkEvent *evt) {
- //獲取VolumeManager實例
- VolumeManager *vm = VolumeManager::Instance();
- //設備類型
- const char *subsys = evt->getSubsystem();
- //將消息傳遞給VolumeManager處理
- if (!strcmp(subsys, "block")) {
- vm->handleBlockEvent(evt);
- }
- }
NetlinkManager通過NetlinkHandler將接收到Kernel內核發送的Uenvet消息,轉化成了NetlinkEvent結構數據傳遞給VolumeManager處理,uevent消息的上傳流程:
2.VolumeManager模塊
啓動流程1)構造VolumeManager對象實例
2)設置事件廣播監聽
3)啓動VolumeManager
4)配置VolumeManager
VolumeManager類關係圖:
DirectVolume是一個實體存儲設備的抽象,通過系統調用直接操作存儲設備。VolumeManager的SocketListenner與NetlinkManager的SocketListenner有所不同的:
NetlinkManager構造的SocketListenner:Kernel與Vold通信;
VolumeManager構造的SocketListenner:Native Vold與Framework MountService 通信;
NetlinkManager與VolumeManager交互流程圖:
1.構造VolumeManager對象
- VolumeManager *VolumeManager::Instance() {
- if (!sInstance)
- sInstance = new VolumeManager();
- return sInstance;
- }
- VolumeManager::VolumeManager() {
- mDebug = false;
- mVolumes = new VolumeCollection();
- mActiveContainers = new AsecIdCollection();
- mBroadcaster = NULL;
- mUmsSharingCount = 0;
- mSavedDirtyRatio = -1;
- // set dirty ratio to 20 when UMS is active
- mUmsDirtyRatio = 20;
- mVolManagerDisabled = 0;
- }
2.啓動VolumeManager
- int VolumeManager::start() {
- return 0;
- }
3.uevent事件處理
- void NetlinkHandler::onEvent(NetlinkEvent *evt) {
- ……
- //將消息傳遞給VolumeManager處理
- if (!strcmp(subsys, "block")) {
- vm->handleBlockEvent(evt);
- }
- }
- void VolumeManager::handleBlockEvent(NetlinkEvent *evt) {
- //有狀態變化設備路徑
- const char *devpath = evt->findParam("DEVPATH");
- //遍歷VolumeManager中所管理Volume對象(各存儲設備代碼抽象)
- for (it = mVolumes->begin(); it != mVolumes->end(); ++it) {
- if (!(*it)->handleBlockEvent(evt)) {
- hit = true;
- break;
- }
- }
- int DirectVolume::handleBlockEvent(NetlinkEvent *evt) {
- //從NetlinkEvent消息中取出有狀態變化設備路徑
- const char *dp = evt->findParam("DEVPATH");
- PathCollection::iterator it;
- //遍歷所有的存儲設備
- for (it = mPaths->begin(); it != mPaths->end(); ++it) {
- //根據存儲設備路徑進行匹配
- if (!strncmp(dp, *it, strlen(*it))) {
- /* 從NetlinkEvent消息中取出設備變化的動作 */
- int action = evt->getAction();
- /* 從NetlinkEvent消息中取出設備類型 */
- const char *devtype = evt->findParam("DEVTYPE");
- SLOGE("DirectVolume::handleBlockEvent() evt's DEVPATH= %s DEVTYPE= %s action= %d",dp, devtype, action); //設備插入
- if (action == NetlinkEvent::NlActionAdd) {
- int major = atoi(evt->findParam("MAJOR"));
- int minor = atoi(evt->findParam("MINOR"));
- char nodepath[255];
- snprintf(nodepath,sizeof(nodepath), "/dev/block/vold/%d:%d",major, minor);
- SLOGE("DirectVolume::handleBlockEvent() NlActionAdd - /dev/block/vold/%d:%d\n", major, minor);
- if (createDeviceNode(nodepath, major, minor)) {
- SLOGE("Error making device node '%s' (%s)", nodepath,strerror(errno));
- }
- //新增磁盤
- if (!strcmp(devtype, "disk")) {
- handleDiskAdded(dp, evt);
- //新增分區
- } else {
- handlePartitionAdded(dp, evt);
- }
- //設備移除
- } else if (action == NetlinkEvent::NlActionRemove) {
- SLOGE("Volume partition %d:%d removed", atoi(evt->findParam("MAJOR")), atoi(evt->findParam("MINOR")));
- //刪除磁盤
- if (!strcmp(devtype, "disk")) {
- handleDiskRemoved(dp, evt);
- //刪除分區
- } else {
- handlePartitionRemoved(dp, evt);
- }
- //設備改變
- } else if (action == NetlinkEvent::NlActionChange) {
- //磁盤變化
- if (!strcmp(devtype, "disk")) {
- handleDiskChanged(dp, evt);
- //分區變化
- } else {
- handlePartitionChanged(dp, evt);
- }
- } else {
- SLOGW("Ignoring non add/remove/change event");
- }
- return 0;
- }
- }
- errno = ENODEV;
- return -1;
- }
每一個Volume可能對應多個Path;即一個掛載點對應多個物理設備,因此VolumeManager中的每一個Volume對象都需要處理SD狀態變換消息,當新增一個disk時:
- void DirectVolume::handleDiskAdded(const char *devpath, NetlinkEvent *evt) {
- //主次設備號
- mDiskMajor = atoi(evt->findParam("MAJOR"));
- mDiskMinor = atoi(evt->findParam("MINOR"));
- //設備分區情況
- const char *tmp = evt->findParam("NPARTS");
- mDiskNumParts = atoi(tmp);
- if (mDiskNumParts == 0) {
- //沒有分區,Volume狀態爲Idle
- setState(Volume::State_Idle);
- } else {
- //有分區未加載,設置Volume狀態Pending
- setState(Volume::State_Pending);
- }
- //格式化通知msg:"Volume sdcard /mnt/sdcard disk inserted (179:0)"
- char msg[255];
- snprintf(msg, sizeof(msg), "Volume %s %s disk inserted (%d:%d)",getLabel(), getMountpoint(), mDiskMajor, mDiskMinor);
- //調用VolumeManager中的Broadcaster——>CommandListener 發送此msg
- mVm->getBroadcaster()->sendBroadcast(ResponseCode::VolumeDiskInserted,msg, false);
- }
- void SocketListener::sendBroadcast(int code, const char *msg, bool addErrno)
- {
- pthread_mutex_lock(&mClientsLock);
- //遍歷所有的消息接收時創建的Client SocketClient
- // SocketClient將消息通過socket(“vold”)通信
- for (i = mClients->begin(); i != mClients->end(); ++i) {
- (*i)->sendMsg(code, msg, addErrno, false);
- }
- pthread_mutex_unlock(&mClientsLock);
- }
3.CommandListener模塊
2)調用startListener函數啓動監聽
1.構造CommandListener對象
- CommandListener::CommandListener() :
- FrameworkListener("vold", true) {
- //註冊Framework發送的相關命令 Command模式
- registerCmd(new DumpCmd());
- registerCmd(new VolumeCmd());
- registerCmd(new AsecCmd());
- registerCmd(new ObbCmd());
- registerCmd(new StorageCmd());
- registerCmd(new XwarpCmd());
- registerCmd(new CryptfsCmd());
- }
- FrameworkListener::FrameworkListener(const char *socketName, bool withSeq) :
- SocketListener(socketName, true, withSeq) {
- init(socketName, withSeq);
- }
- void FrameworkListener::init(const char *socketName, bool withSeq) {
- mCommands = new FrameworkCommandCollection();
- errorRate = 0;
- mCommandCount = 0;
- mWithSeq = withSeq;
- }
- SocketListener::SocketListener(const char *socketName, bool listen, bool useCmdNum) {
- init(socketName, -1, listen, useCmdNum);
- }
- void SocketListener::init(const char *socketName, int socketFd, bool listen, bool useCmdNum) {
- mListen = listen;
- mSocketName = socketName;
- mSock = socketFd;
- mUseCmdNum = useCmdNum;
- pthread_mutex_init(&mClientsLock, NULL);
- mClients = new SocketClientCollection();
- }
- void FrameworkListener::registerCmd(FrameworkCommand *cmd) {
- mCommands->push_back(cmd);
- }
2.啓動CommandListener監聽
- int SocketListener::startListener() {
- //mSocketName = “Vold”
- mSock = android_get_control_socket(mSocketName);
- //NetlinkHandler mListen爲true 監聽socket
- if (mListen && < 0) {
- return -1;
- } else if (!mListen){
- mClients->push_back(new SocketClient(mSock, false, mUseCmdNum));
- }
- //創建匿名管道
- pipe(mCtrlPipe);
- //創建線程執行函數threadStart 參數this
- pthread_create(&mThread, NULL, SocketListener::threadStart, this);
- }
- void *SocketListener::threadStart(void *obj) {
- SocketListener *me = reinterpret_cast<SocketListener *>(obj);
- me->runListener();
- }
- void SocketListener::runListener() {
- //SocketClient List
- SocketClientCollection *pendingList = new SocketClientCollection();
- while(1) {
- fd_set read_fds;
- //mListen 爲true
- if (mListen) {
- max = mSock;
- FD_SET(mSock, &read_fds);
- }
- //加入一組文件描述符集合 選擇fd最大的max select有關
- FD_SET(mCtrlPipe[0], &read_fds);
- pthread_mutex_lock(&mClientsLock);
- for (it = mClients->begin(); it != mClients->end(); ++it) {
- int fd = (*it)->getSocket();
- FD_SET(fd, &read_fds);
- if (fd > max)
- max = fd;
- }
- pthread_mutex_unlock(&mClientsLock);
- //監聽文件描述符是否變化
- rc = select(max + 1, &read_fds, NULL, NULL, NULL);
- //匿名管道被寫,退出線程
- if (FD_ISSET(mCtrlPipe[0], &read_fds))
- break;
- //mListen 爲true
- if (mListen && FD_ISSET(mSock, &read_fds)) {
- //mListen 爲ture 表示正常監聽socket
- struct sockaddr addr;
- do {
- c = accept(mSock, &addr, &alen);
- } while (c < 0 && errno == EINTR);
- //創建一個客戶端SocketClient,加入mClients列表中 到異步延遲處理
- pthread_mutex_lock(&mClientsLock);
- mClients->push_back(new SocketClient(c, true, mUseCmdNum));
- pthread_mutex_unlock(&mClientsLock);
- }
- /* Add all active clients to the pending list first */
- pendingList->clear();
- //將所有有消息的Client加入到pendingList中
- pthread_mutex_lock(&mClientsLock);
- for (it = mClients->begin(); it != mClients->end(); ++it) {
- int fd = (*it)->getSocket();
- if (FD_ISSET(fd, &read_fds)) {
- pendingList->push_back(*it);
- }
- }
- pthread_mutex_unlock(&mClientsLock);
- /* Process the pending list, since it is owned by the thread,*/
- while (!pendingList->empty()) {
- it = pendingList->begin();
- SocketClient* c = *it;
- //處理有數據發送的socket
- if (!onDataAvailable(c) && mListen) {
- //mListen爲true
- ……
- }
- }
- }
- }
啓動CommandListener監聽過程其實就是創建一個監聽的工作線程,用於監聽客戶端即MountService發過來的命令。
3.消息處理
當接收到MountService發送的消息時,將回調onDataAvailable函數進行處理。CommandListener父類FrameworkCommand重寫了消息處理onDataAvailable函數。
- bool FrameworkListener::onDataAvailable(SocketClient *c) {
- char buffer[255];
- //讀取socket消息
- len = TEMP_FAILURE_RETRY(read(c->getSocket(), buffer, sizeof(buffer)));
- for (i = 0; i < len; i++) {
- if (buffer[i] == '\0') {
- //根據消息內容 派發命令
- dispatchCommand(c, buffer + offset);
- offset = i + 1;
- }
- }
- return true;
- }
- void FrameworkListener::dispatchCommand(SocketClient *cli, char *data) {
- char *argv[FrameworkListener::CMD_ARGS_MAX];
- //解析消息內容 命令 參數
- ……
- //執行對應的消息
- for (i = mCommands->begin(); i != mCommands->end(); ++i) {
- FrameworkCommand *c = *i;
- //匹配命令
- if (!strcmp(argv[0], c->getCommand())) {
- //執行命令
- c->runCommand(cli, argc, argv);
- goto out;
- }
- }
- out:
- return;
- }
- int CommandListener::VolumeCmd::runCommand(SocketClient *cli,int argc, char **argv) {
- dumpArgs(argc, argv, -1);
- if (argc < 2) {
- cli->sendMsg(ResponseCode::CommandSyntaxError, "Missing Argument", false);
- return 0;
- }
- VolumeManager *vm = VolumeManager::Instance();
- int rc = 0;
- //查看存儲設備
- if (!strcmp(argv[1], "list")) {
- return vm->listVolumes(cli);
- } else if (!strcmp(argv[1], "debug")) {
- if (argc != 3 || (argc == 3 && (strcmp(argv[2], "off") && strcmp(argv[2], "on")))) {
- cli->sendMsg(ResponseCode::CommandSyntaxError, "Usage: volume debug <off/on>", false);
- return 0;
- }
- vm->setDebug(!strcmp(argv[2], "on") ? true : false);
- //掛載存儲設備
- } else if (!strcmp(argv[1], "mount")) {
- if (argc != 3) {
- cli->sendMsg(ResponseCode::CommandSyntaxError, "Usage: volume mount <path>", false);
- return 0;
- }
- rc = vm->mountVolume(argv[2]);
- //卸載存儲設備
- } else if (!strcmp(argv[1], "unmount")) {
- if (argc < 3 || argc > 4 ||
- ((argc == 4 && strcmp(argv[3], "force")) &&
- (argc == 4 && strcmp(argv[3], "force_and_revert")))) {
- cli->sendMsg(ResponseCode::CommandSyntaxError, "Usage: volume unmount <path> [force|force_and_revert]", false);
- return 0;
- }
- bool force = false;
- bool revert = false;
- if (argc >= 4 && !strcmp(argv[3], "force")) {
- force = true;
- } else if (argc >= 4 && !strcmp(argv[3], "force_and_revert")) {
- force = true;
- revert = true;
- }
- rc = vm->unmountVolume(argv[2], force, revert);
- //格式化存儲設備
- } else if (!strcmp(argv[1], "format")) {
- if (argc != 3) {
- cli->sendMsg(ResponseCode::CommandSyntaxError, "Usage: volume format <path>", false);
- return 0;
- }
- rc = vm->formatVolume(argv[2]);
- //共享存儲設備
- } else if (!strcmp(argv[1], "share")) {
- if (argc != 4) {
- cli->sendMsg(ResponseCode::CommandSyntaxError,
- "Usage: volume share <path> <method>", false);
- return 0;
- }
- rc = vm->shareVolume(argv[2], argv[3]);
- } else if (!strcmp(argv[1], "unshare")) {
- if (argc != 4) {
- cli->sendMsg(ResponseCode::CommandSyntaxError,
- "Usage: volume unshare <path> <method>", false);
- return 0;
- }
- rc = vm->unshareVolume(argv[2], argv[3]);
- } else if (!strcmp(argv[1], "shared")) {
- bool enabled = false;
- if (argc != 4) {
- cli->sendMsg(ResponseCode::CommandSyntaxError,
- "Usage: volume shared <path> <method>", false);
- return 0;
- }
- if (vm->shareEnabled(argv[2], argv[3], &enabled)) {
- cli->sendMsg(
- ResponseCode::OperationFailed, "Failed to determine share enable state", true);
- } else {
- cli->sendMsg(ResponseCode::ShareEnabledResult,
- (enabled ? "Share enabled" : "Share disabled"), false);
- }
- return 0;
- } else {
- cli->sendMsg(ResponseCode::CommandSyntaxError, "Unknown volume cmd", false);
- }
- if (!rc) {
- cli->sendMsg(ResponseCode::CommandOkay, "volume operation succeeded", false);
- } else {
- int erno = errno;
- rc = ResponseCode::convertFromErrno();
- cli->sendMsg(rc, "volume operation failed", true);
- }
- return 0;
- }
- int VolumeManager::mountVolume(const char *label) {
- //根據卷標查找Volume
- Volume *v = lookupVolume(label);
- if (!v) {
- errno = ENOENT;
- return -1;
- }
- return v->mountVol();
- }
整個Vold處理過程框架圖如下: