1 files changed, 25 insertions, 22 deletions

diff --git a/roots.cpp b/roots.cpp
index 6e5ef9810..9b4270256 100644
--- a/roots.cpp
+++ b/roots.cpp
@@ -232,14 +232,14 @@ int format_volume(const char* volume, const char* directory) {
                            << ") not supported on " << v->fs_type;
                 return -1;
             }
-            char *num_sectors;
-            if (asprintf(&num_sectors, "%zd", length / 512) <= 0) {
+            char *num_sectors = nullptr;
+            if (length >= 512 && asprintf(&num_sectors, "%zd", length / 512) <= 0) {
                 LOG(ERROR) << "format_volume: failed to create " << v->fs_type
                            << " command for " << v->blk_device;
                 return -1;
             }
             const char *f2fs_path = "/sbin/mkfs.f2fs";
-            const char* const f2fs_argv[] = {"mkfs.f2fs", "-t", "-d1", v->blk_device, num_sectors, NULL};
+            const char* const f2fs_argv[] = {"mkfs.f2fs", "-t", "-d1", v->blk_device, num_sectors, nullptr};
 
             result = exec_cmd(f2fs_path, (char* const*)f2fs_argv);
             free(num_sectors);
@@ -260,26 +260,29 @@ int format_volume(const char* volume) {
 }
 
 int setup_install_mounts() {
-    if (fstab == NULL) {
-        LOG(ERROR) << "can't set up install mounts: no fstab loaded";
-        return -1;
-    }
-    for (int i = 0; i < fstab->num_entries; ++i) {
-        Volume* v = fstab->recs + i;
+  if (fstab == nullptr) {
+    LOG(ERROR) << "can't set up install mounts: no fstab loaded";
+    return -1;
+  }
+  for (int i = 0; i < fstab->num_entries; ++i) {
+    const 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) {
-                LOG(ERROR) << "failed to mount " << v->mount_point;
-                return -1;
-            }
+    // We don't want to do anything with "/".
+    if (strcmp(v->mount_point, "/") == 0) {
+      continue;
+    }
 
-        } else {
-            if (ensure_path_unmounted(v->mount_point) != 0) {
-                LOG(ERROR) << "failed to unmount " << v->mount_point;
-                return -1;
-            }
-        }
+    if (strcmp(v->mount_point, "/tmp") == 0 || strcmp(v->mount_point, "/cache") == 0) {
+      if (ensure_path_mounted(v->mount_point) != 0) {
+        LOG(ERROR) << "failed to mount " << v->mount_point;
+        return -1;
+      }
+    } else {
+      if (ensure_path_unmounted(v->mount_point) != 0) {
+        LOG(ERROR) << "failed to unmount " << v->mount_point;
+        return -1;
+      }
     }
-    return 0;
+  }
+  return 0;
 }