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/PublicVolume.cpp b/model/PublicVolume.cpp
index d1b63a3..007fd60 100644
--- a/model/PublicVolume.cpp
+++ b/model/PublicVolume.cpp
@@ -43,11 +43,11 @@
 namespace android {
 namespace vold {
 
-static const char* kFusePath = "/system/bin/sdcard";
+static const char* kSdcardFsPath = "/system/bin/sdcard";
 
 static const char* kAsecPath = "/mnt/secure/asec";
 
-PublicVolume::PublicVolume(dev_t device) : VolumeBase(Type::kPublic), mDevice(device), mFusePid(0) {
+PublicVolume::PublicVolume(dev_t device) : VolumeBase(Type::kPublic), mDevice(device) {
     setId(StringPrintf("public:%u,%u", major(device), minor(device)));
     mDevPath = StringPrintf("/dev/block/vold/%s", getId().c_str());
 }
@@ -120,10 +120,10 @@
 
     mRawPath = StringPrintf("/mnt/media_rw/%s", stableName.c_str());
 
-    mFuseDefault = StringPrintf("/mnt/runtime/default/%s", stableName.c_str());
-    mFuseRead = StringPrintf("/mnt/runtime/read/%s", stableName.c_str());
-    mFuseWrite = StringPrintf("/mnt/runtime/write/%s", stableName.c_str());
-    mFuseFull = StringPrintf("/mnt/runtime/full/%s", stableName.c_str());
+    mSdcardFsDefault = StringPrintf("/mnt/runtime/default/%s", stableName.c_str());
+    mSdcardFsRead = StringPrintf("/mnt/runtime/read/%s", stableName.c_str());
+    mSdcardFsWrite = StringPrintf("/mnt/runtime/write/%s", stableName.c_str());
+    mSdcardFsFull = StringPrintf("/mnt/runtime/full/%s", stableName.c_str());
 
     setInternalPath(mRawPath);
     if (getMountFlags() & MountFlags::kVisible) {
@@ -155,19 +155,19 @@
     }
 
     if (!(getMountFlags() & MountFlags::kVisible)) {
-        // Not visible to apps, so no need to spin up FUSE
+        // Not visible to apps, so no need to spin up sdcardfs or FUSE
         return OK;
     }
 
-    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)) {
-        PLOG(ERROR) << getId() << " failed to create FUSE mount points";
+    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 sdcardfs mount points";
         return -errno;
     }
 
-    dev_t before = GetDevice(mFuseFull);
+    dev_t before = GetDevice(mSdcardFsFull);
 
     bool isFuse = base::GetBoolProperty(kPropFuseSnapshot, false);
     if (isFuse) {
@@ -193,10 +193,11 @@
         return OK;
     }
 
-    if (!(mFusePid = fork())) {
+    int sdcardFsPid;
+    if (!(sdcardFsPid = fork())) {
         if (getMountFlags() & MountFlags::kPrimary) {
             // clang-format off
-            if (execl(kFusePath, kFusePath,
+            if (execl(kSdcardFsPath, kSdcardFsPath,
                     "-u", "1023", // AID_MEDIA_RW
                     "-g", "1023", // AID_MEDIA_RW
                     "-U", std::to_string(getMountUserId()).c_str(),
@@ -209,7 +210,7 @@
             }
         } else {
             // clang-format off
-            if (execl(kFusePath, kFusePath,
+            if (execl(kSdcardFsPath, kSdcardFsPath,
                     "-u", "1023", // AID_MEDIA_RW
                     "-g", "1023", // AID_MEDIA_RW
                     "-U", std::to_string(getMountUserId()).c_str(),
@@ -221,29 +222,28 @@
             }
         }
 
-        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;
 }
@@ -283,22 +283,22 @@
 
     ForceUnmount(kAsecPath);
 
-    ForceUnmount(mFuseDefault);
-    ForceUnmount(mFuseRead);
-    ForceUnmount(mFuseWrite);
-    ForceUnmount(mFuseFull);
+    ForceUnmount(mSdcardFsDefault);
+    ForceUnmount(mSdcardFsRead);
+    ForceUnmount(mSdcardFsWrite);
+    ForceUnmount(mSdcardFsFull);
     ForceUnmount(mRawPath);
 
-    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());
     rmdir(mRawPath.c_str());
 
-    mFuseDefault.clear();
-    mFuseRead.clear();
-    mFuseWrite.clear();
-    mFuseFull.clear();
+    mSdcardFsDefault.clear();
+    mSdcardFsRead.clear();
+    mSdcardFsWrite.clear();
+    mSdcardFsFull.clear();
     mRawPath.clear();
 
     return OK;