Get rid of confusing FUSE variables and comments.

Long before scoped storage, FUSE was used to create several views of the
filesystem; this was later replaced by sdcardfs, yet the code still
references FUSE in variables and log messages. Fix those up to avoid
confusion with the "new FUSE".

Bug: 135341433
Test: atest AdoptableHostTest
Change-Id: I2966c5f95d6f38df36a20cdfdd0b95b3051f3f1e
diff --git a/model/EmulatedVolume.cpp b/model/EmulatedVolume.cpp
index eb6b8a3..705bf79 100644
--- a/model/EmulatedVolume.cpp
+++ b/model/EmulatedVolume.cpp
@@ -40,10 +40,10 @@
 namespace android {
 namespace vold {
 
-static const char* kFusePath = "/system/bin/sdcard";
+static const char* kSdcardFsPath = "/system/bin/sdcard";
 
 EmulatedVolume::EmulatedVolume(const std::string& rawPath, int userId)
-    : VolumeBase(Type::kEmulated), mFusePid(0) {
+    : VolumeBase(Type::kEmulated) {
     setId(StringPrintf("emulated;%u", userId));
     mRawPath = rawPath;
     mLabel = "emulated";
@@ -51,7 +51,7 @@
 
 EmulatedVolume::EmulatedVolume(const std::string& rawPath, dev_t device, const std::string& fsUuid,
                                int userId)
-    : VolumeBase(Type::kEmulated), mFusePid(0) {
+    : VolumeBase(Type::kEmulated) {
     setId(StringPrintf("emulated:%u,%u;%u", major(device), minor(device), userId));
     mRawPath = rawPath;
     mLabel = fsUuid;
@@ -67,23 +67,23 @@
         label = "emulated";
     }
 
-    mFuseDefault = StringPrintf("/mnt/runtime/default/%s", label.c_str());
-    mFuseRead = StringPrintf("/mnt/runtime/read/%s", label.c_str());
-    mFuseWrite = StringPrintf("/mnt/runtime/write/%s", label.c_str());
-    mFuseFull = StringPrintf("/mnt/runtime/full/%s", label.c_str());
+    mSdcardFsDefault = StringPrintf("/mnt/runtime/default/%s", label.c_str());
+    mSdcardFsRead = StringPrintf("/mnt/runtime/read/%s", label.c_str());
+    mSdcardFsWrite = StringPrintf("/mnt/runtime/write/%s", label.c_str());
+    mSdcardFsFull = StringPrintf("/mnt/runtime/full/%s", label.c_str());
 
     setInternalPath(mRawPath);
     setPath(StringPrintf("/storage/%s", label.c_str()));
 
-    if (fs_prepare_dir(mFuseDefault.c_str(), 0700, AID_ROOT, AID_ROOT) ||
-        fs_prepare_dir(mFuseRead.c_str(), 0700, AID_ROOT, AID_ROOT) ||
-        fs_prepare_dir(mFuseWrite.c_str(), 0700, AID_ROOT, AID_ROOT) ||
-        fs_prepare_dir(mFuseFull.c_str(), 0700, AID_ROOT, AID_ROOT)) {
+    if (fs_prepare_dir(mSdcardFsDefault.c_str(), 0700, AID_ROOT, AID_ROOT) ||
+        fs_prepare_dir(mSdcardFsRead.c_str(), 0700, AID_ROOT, AID_ROOT) ||
+        fs_prepare_dir(mSdcardFsWrite.c_str(), 0700, AID_ROOT, AID_ROOT) ||
+        fs_prepare_dir(mSdcardFsFull.c_str(), 0700, AID_ROOT, AID_ROOT)) {
         PLOG(ERROR) << getId() << " failed to create mount points";
         return -errno;
     }
 
-    dev_t before = GetDevice(mFuseFull);
+    dev_t before = GetDevice(mSdcardFsFull);
 
     bool isFuse = base::GetBoolProperty(kPropFuseSnapshot, false);
 
@@ -116,9 +116,10 @@
     }
 
     LOG(INFO) << "Executing sdcardfs";
-    if (!(mFusePid = fork())) {
+    int sdcardFsPid;
+    if (!(sdcardFsPid = fork())) {
         // clang-format off
-        if (execl(kFusePath, kFusePath,
+        if (execl(kSdcardFsPath, kSdcardFsPath,
                 "-u", "1023", // AID_MEDIA_RW
                 "-g", "1023", // AID_MEDIA_RW
                 "-m",
@@ -133,29 +134,28 @@
             PLOG(ERROR) << "Failed to exec";
         }
 
-        LOG(ERROR) << "FUSE exiting";
+        LOG(ERROR) << "sdcardfs exiting";
         _exit(1);
     }
 
-    if (mFusePid == -1) {
+    if (sdcardFsPid == -1) {
         PLOG(ERROR) << getId() << " failed to fork";
         return -errno;
     }
 
     nsecs_t start = systemTime(SYSTEM_TIME_BOOTTIME);
-    while (before == GetDevice(mFuseFull)) {
-        LOG(DEBUG) << "Waiting for FUSE to spin up...";
+    while (before == GetDevice(mSdcardFsFull)) {
+        LOG(DEBUG) << "Waiting for sdcardfs to spin up...";
         usleep(50000);  // 50ms
 
         nsecs_t now = systemTime(SYSTEM_TIME_BOOTTIME);
         if (nanoseconds_to_milliseconds(now - start) > 5000) {
-            LOG(WARNING) << "Timed out while waiting for FUSE to spin up";
+            LOG(WARNING) << "Timed out while waiting for sdcardfs to spin up";
             return -ETIMEDOUT;
         }
     }
-    /* sdcardfs will have exited already. FUSE will still be running */
-    TEMP_FAILURE_RETRY(waitpid(mFusePid, nullptr, 0));
-    mFusePid = 0;
+    /* sdcardfs will have exited already. The filesystem will still be running */
+    TEMP_FAILURE_RETRY(waitpid(sdcardFsPid, nullptr, 0));
 
     return OK;
 }
@@ -193,20 +193,20 @@
         return OK;
     }
 
-    ForceUnmount(mFuseDefault);
-    ForceUnmount(mFuseRead);
-    ForceUnmount(mFuseWrite);
-    ForceUnmount(mFuseFull);
+    ForceUnmount(mSdcardFsDefault);
+    ForceUnmount(mSdcardFsRead);
+    ForceUnmount(mSdcardFsWrite);
+    ForceUnmount(mSdcardFsFull);
 
-    rmdir(mFuseDefault.c_str());
-    rmdir(mFuseRead.c_str());
-    rmdir(mFuseWrite.c_str());
-    rmdir(mFuseFull.c_str());
+    rmdir(mSdcardFsDefault.c_str());
+    rmdir(mSdcardFsRead.c_str());
+    rmdir(mSdcardFsWrite.c_str());
+    rmdir(mSdcardFsFull.c_str());
 
-    mFuseDefault.clear();
-    mFuseRead.clear();
-    mFuseWrite.clear();
-    mFuseFull.clear();
+    mSdcardFsDefault.clear();
+    mSdcardFsRead.clear();
+    mSdcardFsWrite.clear();
+    mSdcardFsFull.clear();
 
     return OK;
 }