vold: support "volume list [broadcast]" command

Sometimes when an sdcard is already mounted,
some info like uuid and label are not re-broadcast to new listeners.
The extra argument to list allows late listeners to catch up by asking
volume list to broadcast that info again.

Bug: 16253597
Bug: 16306775
Change-Id: Ie7d0c1132c22d307a5b2a0e50075a3716138d00b
Signed-off-by: Benson Huang <benson.huang@mediatek.com>
(cherry picked from commit 85f4700f44170b772697e627b3075dcb9137e1b7)

CommandListener.cpp

@@ -131,7 +131,8 @@ int CommandListener::VolumeCmd::runCommand(SocketClient *cli,
     int rc = 0;
 
     if (!strcmp(argv[1], "list")) {
-        return vm->listVolumes(cli);
+        bool broadcast = argc >= 3 && !strcmp(argv[2], "broadcast");
+        return vm->listVolumes(cli, broadcast);
     } 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);

VolumeManager.cpp

@@ -260,8 +260,9 @@ void VolumeManager::handleBlockEvent(NetlinkEvent *evt) {
     }
 }
 
-int VolumeManager::listVolumes(SocketClient *cli) {
+int VolumeManager::listVolumes(SocketClient *cli, bool broadcast) {
     VolumeCollection::iterator i;
+    char msg[256];
 
     for (i = mVolumes->begin(); i != mVolumes->end(); ++i) {
         char *buffer;
@@ -270,6 +271,20 @@ int VolumeManager::listVolumes(SocketClient *cli) {
                  (*i)->getState());
         cli->sendMsg(ResponseCode::VolumeListResult, buffer, false);
         free(buffer);
+        if (broadcast) {
+            if((*i)->getUuid()) {
+                snprintf(msg, sizeof(msg), "%s %s \"%s\"", (*i)->getLabel(),
+                    (*i)->getFuseMountpoint(), (*i)->getUuid());
+                mBroadcaster->sendBroadcast(ResponseCode::VolumeUuidChange,
+                    msg, false);
+            }
+            if((*i)->getUserLabel()) {
+                snprintf(msg, sizeof(msg), "%s %s \"%s\"", (*i)->getLabel(),
+                    (*i)->getFuseMountpoint(), (*i)->getUserLabel());
+                mBroadcaster->sendBroadcast(ResponseCode::VolumeUserLabelChange,
+                    msg, false);
+            }
+        }
     }
     cli->sendMsg(ResponseCode::CommandOkay, "Volumes listed.", false);
     return 0;

VolumeManager.h

@@ -77,7 +77,7 @@ public:
 
     int addVolume(Volume *v);
 
-    int listVolumes(SocketClient *cli);
+    int listVolumes(SocketClient *cli, bool broadcast);
     int mountVolume(const char *label);
     int unmountVolume(const char *label, bool force, bool revert);
     int shareVolume(const char *label, const char *method);