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platform_system_core
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Merge "Remove logic to fake /system in overlayfs"

This commit is contained in:
Tom Cherry 2019-02-12 01:04:21 +00:00 committed by Gerrit Code Review
parent ea57928f00 6576e13995
commit d2ae1c91ed
2 changed files with 47 additions and 21 deletions
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20
fs_mgr/fs_mgr_overlayfs.cpp
View File

@ -565,26 +565,6 @@ std::vector<std::string> fs_mgr_candidate_list(Fstab* fstab, const char* mount_p
if (!duplicate_or_more_specific) mounts.emplace_back(new_mount_point);
}
// if not itemized /system or /, system as root, fake one up?
// do we want or need to?
if (mount_point && ("/system"s != mount_point)) return mounts;
if (std::find(mounts.begin(), mounts.end(), "/system") != mounts.end()) return mounts;
// fs_mgr_overlayfs_verity_enabled_list says not to?
if (std::find(verity.begin(), verity.end(), "system") != verity.end()) return mounts;
// confirm that fstab is missing system
if (GetEntryForMountPoint(fstab, "/") != nullptr ||
GetEntryForMountPoint(fstab, "/system") != nullptr) {
return mounts;
}
// We have a stunted fstab (w/o system or / ) passed in by the caller,
// verity claims are assumed accurate because they are collected internally
// from fs_mgr_fstab_default() from within fs_mgr_update_verity_state(),
// Can (re)evaluate /system with impunity since we know it is ever-present.
mounts.emplace_back("/system");
return mounts;
}

48
init/first_stage_mount.cpp
View File

@ -157,6 +157,37 @@ static Fstab ReadFirstStageFstab() {
return fstab;
}
static bool GetRootEntry(FstabEntry* root_entry) {
Fstab proc_mounts;
if (!ReadFstabFromFile("/proc/mounts", &proc_mounts)) {
LOG(ERROR) << "Could not read /proc/mounts and /system not in fstab, /system will not be "
"available for overlayfs";
return false;
}
auto entry = std::find_if(proc_mounts.begin(), proc_mounts.end(), [](const auto& entry) {
return entry.mount_point == "/" && entry.fs_type != "rootfs";
});
if (entry == proc_mounts.end()) {
LOG(ERROR) << "Could not get mount point for '/' in /proc/mounts, /system will not be "
"available for overlayfs";
return false;
}
*root_entry = std::move(*entry);
// We don't know if we're avb or not, so we query device mapper as if we are avb. If we get a
// success, then mark as avb, otherwise default to verify.
auto& dm = android::dm::DeviceMapper::Instance();
if (dm.GetState("vroot") != android::dm::DmDeviceState::INVALID) {
root_entry->fs_mgr_flags.avb = true;
} else {
root_entry->fs_mgr_flags.verify = true;
}
return true;
}
// Class Definitions
// -----------------
FirstStageMount::FirstStageMount(Fstab fstab)
@ -443,7 +474,7 @@ bool FirstStageMount::TrySwitchSystemAsRoot() {
if (system_partition == fstab_.end()) return true;
if (MountPartition(system_partition, true /* erase_used_fstab_entry */)) {
if (MountPartition(system_partition, false)) {
SwitchRoot("/system");
} else {
PLOG(ERROR) << "Failed to mount /system";
@ -487,6 +518,12 @@ bool FirstStageMount::MountPartitions() {
if (!TrySkipMountingPartitions()) return false;
for (auto current = fstab_.begin(); current != fstab_.end();) {
// We've already mounted /system above.
if (current->mount_point == "/system") {
++current;
continue;
}
Fstab::iterator end;
if (!MountPartition(current, false, &end)) {
if (current->fs_mgr_flags.no_fail) {
@ -503,6 +540,15 @@ bool FirstStageMount::MountPartitions() {
current = end;
}
// If we don't see /system or / in the fstab, then we need to create an root entry for
// overlayfs.
if (!GetEntryForMountPoint(&fstab_, "/system") && !GetEntryForMountPoint(&fstab_, "/")) {
FstabEntry root_entry;
if (GetRootEntry(&root_entry)) {
fstab_.emplace_back(std::move(root_entry));
}
}
// heads up for instantiating required device(s) for overlayfs logic
const auto devices = fs_mgr_overlayfs_required_devices(&fstab_);
for (auto const& device : devices) {