diff --git a/install.cpp b/install.cpp
index e1ab848..797a525 100644
--- a/install.cpp
+++ b/install.cpp
@@ -180,7 +180,9 @@
 {
     ui->SetBackground(RecoveryUI::INSTALLING_UPDATE);
     ui->Print("Finding update package...\n");
-    ui->SetProgressType(RecoveryUI::INDETERMINATE);
+    // Give verification half the progress bar...
+    ui->SetProgressType(RecoveryUI::DETERMINATE);
+    ui->ShowProgress(VERIFICATION_PROGRESS_FRACTION, VERIFICATION_PROGRESS_TIME);
     LOGI("Update location: %s\n", path);
 
     if (ensure_path_mounted(path) != 0) {
@@ -198,10 +200,7 @@
     }
     LOGI("%d key(s) loaded from %s\n", numKeys, PUBLIC_KEYS_FILE);
 
-    // Give verification half the progress bar...
     ui->Print("Verifying update package...\n");
-    ui->SetProgressType(RecoveryUI::DETERMINATE);
-    ui->ShowProgress(VERIFICATION_PROGRESS_FRACTION, VERIFICATION_PROGRESS_TIME);
 
     int err;
     err = verify_file(path, loadedKeys, numKeys);
@@ -237,7 +236,13 @@
     } else {
         LOGE("failed to open last_install: %s\n", strerror(errno));
     }
-    int result = really_install_package(path, wipe_cache);
+    int result;
+    if (setup_install_mounts() != 0) {
+        LOGE("failed to set up expected mounts for install; aborting\n");
+        result = INSTALL_ERROR;
+    } else {
+        result = really_install_package(path, wipe_cache);
+    }
     if (install_log) {
         fputc(result == INSTALL_SUCCESS ? '1' : '0', install_log);
         fputc('\n', install_log);
diff --git a/recovery.cpp b/recovery.cpp
index 38366b6..654a665 100644
--- a/recovery.cpp
+++ b/recovery.cpp
@@ -811,10 +811,6 @@
                 break;
 
             case Device::APPLY_EXT:
-                // Some packages expect /cache to be mounted (eg,
-                // standard incremental packages expect to use /cache
-                // as scratch space).
-                ensure_path_mounted(CACHE_ROOT);
                 status = update_directory(SDCARD_ROOT, SDCARD_ROOT, &wipe_cache, device);
                 if (status == INSTALL_SUCCESS && wipe_cache) {
                     ui->Print("\n-- Wiping cache (at package request)...\n");
@@ -860,7 +856,6 @@
                 break;
 
             case Device::APPLY_ADB_SIDELOAD:
-                ensure_path_mounted(CACHE_ROOT);
                 status = apply_from_adb(ui, &wipe_cache, TEMPORARY_INSTALL_FILE);
                 if (status >= 0) {
                     if (status != INSTALL_SUCCESS) {
diff --git a/roots.cpp b/roots.cpp
index 0947122..113dba1 100644
--- a/roots.cpp
+++ b/roots.cpp
@@ -202,3 +202,22 @@
     LOGE("format_volume: fs_type \"%s\" unsupported\n", v->fs_type);
     return -1;
 }
+
+int setup_install_mounts() {
+    if (fstab == NULL) {
+        LOGE("can't set up install mounts: no fstab loaded\n");
+        return -1;
+    }
+    for (int i = 0; i < fstab->num_entries; ++i) {
+        Volume* v = fstab->recs + i;
+
+        if (strcmp(v->mount_point, "/tmp") == 0 ||
+            strcmp(v->mount_point, "/cache") == 0) {
+            if (ensure_path_mounted(v->mount_point) != 0) return -1;
+
+        } else {
+            if (ensure_path_unmounted(v->mount_point) != 0) return -1;
+        }
+    }
+    return 0;
+}
diff --git a/roots.h b/roots.h
index 8abe18f..230d9de 100644
--- a/roots.h
+++ b/roots.h
@@ -42,6 +42,10 @@
 // it is mounted.
 int format_volume(const char* volume);
 
+// Ensure that all and only the volumes that packages expect to find
+// mounted (/tmp and /cache) are mounted.  Returns 0 on success.
+int setup_install_mounts();
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/screen_ui.cpp b/screen_ui.cpp
index 6a63858..8376341 100644
--- a/screen_ui.cpp
+++ b/screen_ui.cpp
@@ -467,10 +467,11 @@
     pthread_mutex_lock(&updateMutex);
     if (progressBarType != type) {
         progressBarType = type;
-        update_progress_locked();
     }
     progressScopeStart = 0;
+    progressScopeSize = 0;
     progress = 0;
+    update_progress_locked();
     pthread_mutex_unlock(&updateMutex);
 }