remount: Remove the "backing" parameter to fs_mgr_overlayfs_setup.

This is unused.

Bug: 241179247
Test: remount
Change-Id: I7a9e07a4cf397c6fc8909a9959e08d1aefa3216a
diff --git a/fs_mgr/fs_mgr_overlayfs.cpp b/fs_mgr/fs_mgr_overlayfs.cpp
index 4fe00d1..0b1eb39 100644
--- a/fs_mgr/fs_mgr_overlayfs.cpp
+++ b/fs_mgr/fs_mgr_overlayfs.cpp
@@ -97,7 +97,7 @@
     return false;
 }
 
-bool fs_mgr_overlayfs_setup(const char*, const char*, bool* change, bool) {
+bool fs_mgr_overlayfs_setup(const char*, bool* change, bool) {
     if (change) *change = false;
     return false;
 }
@@ -1357,8 +1357,7 @@
 
 // Returns false if setup not permitted, errno set to last error.
 // If something is altered, set *change.
-bool fs_mgr_overlayfs_setup(const char* backing, const char* mount_point, bool* change,
-                            bool force) {
+bool fs_mgr_overlayfs_setup(const char* mount_point, bool* change, bool force) {
     if (change) *change = false;
     auto ret = false;
     if (fs_mgr_overlayfs_valid() == OverlayfsValidResult::kNotSupported) return ret;
@@ -1395,7 +1394,6 @@
 
     std::string dir;
     for (const auto& overlay_mount_point : OverlayMountPoints()) {
-        if (backing && backing[0] && (overlay_mount_point != backing)) continue;
         if (overlay_mount_point == kScratchMountPoint) {
             if (!fs_mgr_overlayfs_setup_scratch(fstab, change)) continue;
         } else {
diff --git a/fs_mgr/fs_mgr_remount.cpp b/fs_mgr/fs_mgr_remount.cpp
index d17e4f7..86d095e 100644
--- a/fs_mgr/fs_mgr_remount.cpp
+++ b/fs_mgr/fs_mgr_remount.cpp
@@ -320,7 +320,7 @@
         if (fs_mgr_wants_overlayfs(&entry)) {
             bool change = false;
             bool force = result->disabled_verity;
-            if (!fs_mgr_overlayfs_setup(nullptr, mount_point.c_str(), &change, force)) {
+            if (!fs_mgr_overlayfs_setup(mount_point.c_str(), &change, force)) {
                 LOG(ERROR) << "Overlayfs setup for " << mount_point << " failed, skipping";
                 status = BAD_OVERLAY;
                 it = partitions->erase(it);
diff --git a/fs_mgr/include/fs_mgr_overlayfs.h b/fs_mgr/include/fs_mgr_overlayfs.h
index b328052..ec1d78f 100644
--- a/fs_mgr/include/fs_mgr_overlayfs.h
+++ b/fs_mgr/include/fs_mgr_overlayfs.h
@@ -28,8 +28,8 @@
 
 bool fs_mgr_wants_overlayfs(android::fs_mgr::FstabEntry* entry);
 bool fs_mgr_overlayfs_mount_all(android::fs_mgr::Fstab* fstab);
-bool fs_mgr_overlayfs_setup(const char* backing = nullptr, const char* mount_point = nullptr,
-                            bool* change = nullptr, bool force = true);
+bool fs_mgr_overlayfs_setup(const char* mount_point = nullptr, bool* change = nullptr,
+                            bool force = true);
 bool fs_mgr_overlayfs_teardown(const char* mount_point = nullptr, bool* change = nullptr);
 bool fs_mgr_overlayfs_is_setup();
 bool fs_mgr_has_shared_blocks(const std::string& mount_point, const std::string& dev);
diff --git a/set-verity-state/set-verity-state.cpp b/set-verity-state/set-verity-state.cpp
index d8e3d31..ac91ca0 100644
--- a/set-verity-state/set-verity-state.cpp
+++ b/set-verity-state/set-verity-state.cpp
@@ -52,7 +52,7 @@
   auto change = false;
   errno = 0;
   if (enable ? fs_mgr_overlayfs_teardown(nullptr, &change)
-             : fs_mgr_overlayfs_setup(nullptr, nullptr, &change)) {
+             : fs_mgr_overlayfs_setup(nullptr, &change)) {
     if (change) {
       printf("%s overlayfs\n", enable ? "disabling" : "using");
     }