early_mount: fs_mgr: move all fstab logic into fs_mgr
With init parsing fstab fragments from kernel separately, the fs_mgr
would completely miss the device tree entries. That leads to things like
'adb remount' to go through without warning for verity even if /system
is verified. This happens because 'verity_update_state' completely
misses the partitions passed to android through the device tree.
solution is to teach fs_mgr about device tree fstab entries and add 2
new public APIs.
1. fs_mgr_read_fstab_dt() - reads device tree and returns fstab
generated from it.
2. fs_mgr_read_fstab_default() - reads both device tree fstab and
/fstab.{ro.hardware} and returns the combined table.
This also reduces the hardcoded /fstab.{ro.hardware} occurence only to
fs_mgr and for eveyone who wants to read the "default" fstab must be
changed to call fs_mgr_read_fstab_default() instead. e.g. adb.
b/27805372
Test: Angler was used since it has 2 early mounted partitions instead of
one. 1 verified and 1 unverified.
- Boot angler successfully without early mount
- Boot angler successfully with /vendor early mount and test if 'adb
remount' warns us about verity
- Boot angler successfully with both /system and /vendor early mounted
and ensure 'adb remount' warns us about verity.
- check partitions.system.verified status after /system early mount ot
ensure it is set to VERITY_MODE_DEFAULT.
- 'adb disable-verity' with early mounted /system doesn't work due to
missing changes in adb
TODO:
change adb to use the new fs_mgr_read_fstab_default() API
Change-Id: I82038d87c7a44488e938acce2cc1082c08f6f73a
Signed-off-by: Sandeep Patil <sspatil@google.com>
diff --git a/init/init.cpp b/init/init.cpp
index 05f2cfd..3cb1276 100644
--- a/init/init.cpp
+++ b/init/init.cpp
@@ -502,26 +502,30 @@
std::string dt_value;
std::string file_name = StringPrintf("%s/compatible", android_dt_dir);
- android::base::ReadFileToString(file_name, &dt_value);
- if (!dt_value.compare("android,firmware")) {
- LOG(ERROR) << "firmware/android is not compatible with 'android,firmware'";
- return false;
+ if (android::base::ReadFileToString(file_name, &dt_value)) {
+ // trim the trailing '\0' out, otherwise the comparison
+ // will produce false-negatives.
+ dt_value.resize(dt_value.size() - 1);
+ if (dt_value == "android,firmware") {
+ return true;
+ }
}
- return true;
+ return false;
}
static bool is_dt_fstab_compatible() {
std::string dt_value;
std::string file_name = StringPrintf("%s/%s/compatible", android_dt_dir, "fstab");
- android::base::ReadFileToString(file_name, &dt_value);
- if (!dt_value.compare("android,fstab")) {
- LOG(ERROR) << "firmware/android/fstab is not compatible with 'android,fstab'";
- return false;
+ if (android::base::ReadFileToString(file_name, &dt_value)) {
+ dt_value.resize(dt_value.size() - 1);
+ if (dt_value == "android,fstab") {
+ return true;
+ }
}
- return true;
+ return false;
}
static void process_kernel_dt() {
@@ -664,78 +668,6 @@
}
}
-static std::string import_dt_fstab() {
- std::string fstab;
- if (!is_dt_compatible() || !is_dt_fstab_compatible()) {
- return fstab;
- }
-
- std::string fstabdir_name = StringPrintf("%s/fstab", android_dt_dir);
- std::unique_ptr<DIR, int (*)(DIR*)> fstabdir(opendir(fstabdir_name.c_str()), closedir);
- if (!fstabdir) return fstab;
-
- dirent* dp;
- while ((dp = readdir(fstabdir.get())) != NULL) {
- // skip over name and compatible
- if (dp->d_type != DT_DIR) {
- continue;
- }
-
- // skip if its not 'vendor', 'odm' or 'system'
- if (strcmp(dp->d_name, "odm") && strcmp(dp->d_name, "system") &&
- strcmp(dp->d_name, "vendor")) {
- continue;
- }
-
- // create <dev> <mnt_point> <type> <mnt_flags> <fsmgr_flags>\n
- std::vector<std::string> fstab_entry;
- std::string file_name;
- std::string value;
- file_name = StringPrintf("%s/%s/dev", fstabdir_name.c_str(), dp->d_name);
- if (!android::base::ReadFileToString(file_name, &value)) {
- LOG(ERROR) << "dt_fstab: Failed to find device for partition " << dp->d_name;
- fstab.clear();
- break;
- }
- // trim the terminating '\0' out
- value.resize(value.size() - 1);
- fstab_entry.push_back(value);
- fstab_entry.push_back(StringPrintf("/%s", dp->d_name));
-
- file_name = StringPrintf("%s/%s/type", fstabdir_name.c_str(), dp->d_name);
- if (!android::base::ReadFileToString(file_name, &value)) {
- LOG(ERROR) << "dt_fstab: Failed to find type for partition " << dp->d_name;
- fstab.clear();
- break;
- }
- value.resize(value.size() - 1);
- fstab_entry.push_back(value);
-
- file_name = StringPrintf("%s/%s/mnt_flags", fstabdir_name.c_str(), dp->d_name);
- if (!android::base::ReadFileToString(file_name, &value)) {
- LOG(ERROR) << "dt_fstab: Failed to find type for partition " << dp->d_name;
- fstab.clear();
- break;
- }
- value.resize(value.size() - 1);
- fstab_entry.push_back(value);
-
- file_name = StringPrintf("%s/%s/fsmgr_flags", fstabdir_name.c_str(), dp->d_name);
- if (!android::base::ReadFileToString(file_name, &value)) {
- LOG(ERROR) << "dt_fstab: Failed to find type for partition " << dp->d_name;
- fstab.clear();
- break;
- }
- value.resize(value.size() - 1);
- fstab_entry.push_back(value);
-
- fstab += android::base::Join(fstab_entry, " ");
- fstab += '\n';
- }
-
- return fstab;
-}
-
static bool early_mount_one(struct fstab_rec* rec) {
if (rec && fs_mgr_is_verified(rec)) {
// setup verity and create the dm-XX block device
@@ -770,23 +702,16 @@
/* Early mount vendor and ODM partitions. The fstab is read from device-tree. */
static bool early_mount() {
- std::string fstab = import_dt_fstab();
- if (fstab.empty()) {
- LOG(INFO) << "Early mount skipped (missing fstab in device tree)";
+ // first check if device tree fstab entries are compatible
+ if (!is_dt_fstab_compatible()) {
+ LOG(INFO) << "Early mount skipped (missing/incompatible fstab in device tree)";
return true;
}
- std::unique_ptr<FILE, decltype(&fclose)> fstab_file(
- fmemopen(static_cast<void*>(const_cast<char*>(fstab.c_str())), fstab.length(), "r"), fclose);
- if (!fstab_file) {
- PLOG(ERROR) << "Early mount failed to open fstab file in memory";
- return false;
- }
-
- std::unique_ptr<struct fstab, decltype(&fs_mgr_free_fstab)> tab(
- fs_mgr_read_fstab_file(fstab_file.get()), fs_mgr_free_fstab);
+ std::unique_ptr<fstab, decltype(&fs_mgr_free_fstab)> tab(
+ fs_mgr_read_fstab_dt(), fs_mgr_free_fstab);
if (!tab) {
- LOG(ERROR) << "Early mount fsmgr failed to load fstab from kernel:" << std::endl << fstab;
+ LOG(ERROR) << "Early mount failed to read fstab from device tree";
return false;
}