Try erofs when mounting OTA partitions.
We don't know which filesystem type the partitions may have, but
currently only ext4 and erofs are in use.
A more generic approach would be to use libext2_blkid or the blkid
binary to find the filesystem type from the block device itself, since
update_engine doesn't divulge this information. However this is good
enough for now.
Test: m dist
system/update_engine/scripts/update_device.py out/dist/cf_x86_64_phone-ota-eng.*.zip
on a Cuttlefish device, and check logcat that ext4 mounts fails but
erofs ones work.
Bug: 270940551
Bug: 202022157
Change-Id: I77b9472418d7996695c2b28b20d43711d5c4d771
diff --git a/cmds/installd/otapreopt_chroot.cpp b/cmds/installd/otapreopt_chroot.cpp
index c62734a..1b7acab 100644
--- a/cmds/installd/otapreopt_chroot.cpp
+++ b/cmds/installd/otapreopt_chroot.cpp
@@ -45,6 +45,10 @@
namespace android {
namespace installd {
+// We don't know the filesystem types of the partitions in the update package,
+// so just try the possibilities one by one.
+static constexpr std::array kTryMountFsTypes = {"ext4", "erofs"};
+
static void CloseDescriptor(int fd) {
if (fd >= 0) {
int result = close(fd);
@@ -82,6 +86,27 @@
}
}
+static bool TryMountWithFstypes(const char* block_device, const char* target) {
+ for (int i = 0; i < kTryMountFsTypes.size(); ++i) {
+ const char* fstype = kTryMountFsTypes[i];
+ int mount_result = mount(block_device, target, fstype, MS_RDONLY, /* data */ nullptr);
+ if (mount_result == 0) {
+ return true;
+ }
+ if (errno == EINVAL && i < kTryMountFsTypes.size() - 1) {
+ // Only try the next fstype if mounting failed due to the current one
+ // being invalid.
+ LOG(WARNING) << "Failed to mount " << block_device << " on " << target << " with "
+ << fstype << " - trying " << kTryMountFsTypes[i + 1];
+ } else {
+ PLOG(ERROR) << "Failed to mount " << block_device << " on " << target << " with "
+ << fstype;
+ return false;
+ }
+ }
+ __builtin_unreachable();
+}
+
static void TryExtraMount(const char* name, const char* slot, const char* target) {
std::string partition_name = StringPrintf("%s%s", name, slot);
@@ -91,12 +116,7 @@
if (dm.GetState(partition_name) != dm::DmDeviceState::INVALID) {
std::string path;
if (dm.GetDmDevicePathByName(partition_name, &path)) {
- int mount_result = mount(path.c_str(),
- target,
- "ext4",
- MS_RDONLY,
- /* data */ nullptr);
- if (mount_result == 0) {
+ if (TryMountWithFstypes(path.c_str(), target)) {
return;
}
}
@@ -105,12 +125,7 @@
// Fall back and attempt a direct mount.
std::string block_device = StringPrintf("/dev/block/by-name/%s", partition_name.c_str());
- int mount_result = mount(block_device.c_str(),
- target,
- "ext4",
- MS_RDONLY,
- /* data */ nullptr);
- UNUSED(mount_result);
+ (void)TryMountWithFstypes(block_device.c_str(), target);
}
// Entry for otapreopt_chroot. Expected parameters are: