recovery: Implement a volume manager

This is a copy of the pre-binderized vold which has been converted to
use direct calls instead of sockets and stripped down to only what is
needed to support recovery.

Includes:
  * Replace security_context_t type

    security_context_t has been marked as deprecated in libselinux from
    version 3.2. Update to the `char*` type.

    Bug: 190808996
    Test: m
    Change-Id: I6f40e161251c79893d41e12c368715736578aacc

  * recovery: volmgr: remove unused IsSupported

    Change-Id: If8206658fdfb6108221806c09c99bf0a30f4a586
    Signed-off-by: Jesse Chan <jc@lineageos.org>

  * recovery: volmgr: remove filesystem checks

    Those checks are not strictly necessary and we are
    not building fsck tools for recovery for now.

    Remove those checks so volmgr can be useful.

    Change-Id: I87756c61b933b6cdccd281c6276b686fbd36019f
    Signed-off-by: Jesse Chan <jc@lineageos.org>

  * recovery: fixup `EmulatedVolume creating`

    Avoid dangling pointer. Instead of pointing to FstabEntry create copy.

    Change-Id: I57f76006db09a6add2c173f43175f0f6b848d87b

  * recovery: fix volmgr cleaning up

    Don't reset pointer to netlink manager
    Delete disks in stop() rather then in ~VolumeManager
    Call destroy() before deleting disks cause delete expects the
      disk to be destroyed
    Clear the lists or we would read garbage data on the next scan

    Change-Id: Idadfa1f33b7cb5f2f3c780848a99344a6608420e

  * recovery: handle interrupts in apply update menu

    Change-Id: I1f78f9196634353b77986545332d7d52a5f0c161

Change-Id: Ic82d929e052b5ba70ecf7b475e0a223d77d9687e

3 files changed, 15 insertions, 17 deletions

diff --git a/install/Android.bp b/install/Android.bp
index c5917145..b52ac40e 100644
--- a/install/Android.bp
+++ b/install/Android.bp
@@ -119,6 +119,7 @@ cc_library_static {
 
     shared_libs: [
         "librecovery_ui",
+        "libvolume_manager",
     ],
 
     export_include_dirs: [
diff --git a/install/fuse_install.cpp b/install/fuse_install.cpp
index e481f913..727419d1 100644
--- a/install/fuse_install.cpp
+++ b/install/fuse_install.cpp
@@ -39,7 +39,9 @@
 #include "install/install.h"
 #include "recovery_utils/roots.h"
 
-static constexpr const char* SDCARD_ROOT = "/data/media/0";
+using android::volmgr::VolumeInfo;
+using android::volmgr::VolumeManager;
+
 // How long (in seconds) we wait for the fuse-provided package file to
 // appear, before timing out.
 static constexpr int SDCARD_INSTALL_TIMEOUT = 10;
@@ -56,8 +58,6 @@ static void SetSdcardUpdateBootloaderMessage() {
 
 // Returns the selected filename, or an empty string.
 static std::string BrowseDirectory(const std::string& path, Device* device, RecoveryUI* ui) {
-  ensure_path_mounted(path);
-
   std::unique_ptr<DIR, decltype(&closedir)> d(opendir(path.c_str()), closedir);
   if (!d) {
     PLOG(ERROR) << "error opening " << path;
@@ -140,12 +140,6 @@ static bool StartInstallPackageFuse(std::string_view path) {
     return false;
   }
 
-  if (android::base::StartsWith(path, SDCARD_ROOT)) {
-    // The installation process expects to find the sdcard unmounted. Unmount it with MNT_DETACH so
-    // that our open file continues to work but new references see it as unmounted.
-    umount2("/data", MNT_DETACH);
-  }
-
   return run_fuse_sideload(std::move(fuse_data_provider)) == 0;
 }
 
@@ -208,17 +202,15 @@ InstallResult InstallWithFuseFromPath(std::string_view path, Device* device) {
   return result;
 }
 
-InstallResult ApplyFromSdcard(Device* device) {
+InstallResult ApplyFromStorage(Device* device, VolumeInfo& vi) {
   auto ui = device->GetUI();
-  if (ensure_path_mounted(SDCARD_ROOT) != 0) {
-    LOG(ERROR) << "\n-- Couldn't mount " << SDCARD_ROOT << ".\n";
+  if (!VolumeManager::Instance()->volumeMount(vi.mId)) {
     return INSTALL_NONE;
   }
 
-  std::string path = BrowseDirectory(SDCARD_ROOT, device, ui);
+  std::string path = BrowseDirectory(vi.mPath, device, ui);
   if (path.empty()) {
-    LOG(ERROR) << "\n-- No package file selected.\n";
-    ensure_path_unmounted(SDCARD_ROOT);
+    VolumeManager::Instance()->volumeUnmount(vi.mId);
     return INSTALL_NONE;
   }
 
@@ -231,6 +223,7 @@ InstallResult ApplyFromSdcard(Device* device) {
   SetSdcardUpdateBootloaderMessage();
 
   auto result = InstallWithFuseFromPath(path, device);
-  ensure_path_unmounted(SDCARD_ROOT);
+
+  VolumeManager::Instance()->volumeUnmount(vi.mId);
   return result;
 }
diff --git a/install/include/install/fuse_install.h b/install/include/install/fuse_install.h
index 29c283f4..7c38d0d9 100644
--- a/install/include/install/fuse_install.h
+++ b/install/include/install/fuse_install.h
@@ -22,9 +22,13 @@
 #include "recovery_ui/device.h"
 #include "recovery_ui/ui.h"
 
+#include <volume_manager/VolumeManager.h>
+
+using android::volmgr::VolumeInfo;
+
 // Starts FUSE with the package from |path| as the data source. And installs the package from
 // |FUSE_SIDELOAD_HOST_PATHNAME|. The |path| can point to the location of a package zip file or a
 // block map file with the prefix '@'; e.g. /sdcard/package.zip, @/cache/recovery/block.map.
 InstallResult InstallWithFuseFromPath(std::string_view path, Device* device);
 
-InstallResult ApplyFromSdcard(Device* device);
+InstallResult ApplyFromStorage(Device* device, VolumeInfo& vi);