userdata_checkpoint_remount: delete all devices in dm-stack under /data
This enables unmounting + remounting of metadata encrypted ext4
userdata. Also added a sysprop to force unmount+remount logic even for
f2fs userdata which comes handy for testing, since we don't have
metadata encrypted ext4 devices to test on.
Test: adb shell setprop sys.init.userdata_remount.force_umount_f2fs 1
Test: adb shell /system/bin/vdc checkpoint startCheckpoint 1
Test: adb reboot userspace
Test: adb shell dumpsys activity
Bug: 135984674
Bug: 143970043
Change-Id: Icc30f5c99f4d9ee374352610ae17b5d9814f815b
diff --git a/fs_mgr/fs_mgr.cpp b/fs_mgr/fs_mgr.cpp
index 2dc47bb..7b686f0 100644
--- a/fs_mgr/fs_mgr.cpp
+++ b/fs_mgr/fs_mgr.cpp
@@ -91,6 +91,7 @@
#define ARRAY_SIZE(a) (sizeof(a) / sizeof(*(a)))
using android::base::Basename;
+using android::base::GetBoolProperty;
using android::base::Realpath;
using android::base::StartsWith;
using android::base::unique_fd;
@@ -1357,14 +1358,33 @@
return ret;
}
+static std::string GetBlockDeviceForMountPoint(const std::string& mount_point) {
+ Fstab mounts;
+ if (!ReadFstabFromFile("/proc/mounts", &mounts)) {
+ LERROR << "Can't read /proc/mounts";
+ return "";
+ }
+ auto entry = GetEntryForMountPoint(&mounts, mount_point);
+ if (entry == nullptr) {
+ LWARNING << mount_point << " is not mounted";
+ return "";
+ }
+ return entry->blk_device;
+}
+
// TODO(b/143970043): return different error codes based on which step failed.
int fs_mgr_remount_userdata_into_checkpointing(Fstab* fstab) {
- auto entry = GetMountedEntryForUserdata(fstab);
- if (entry == nullptr) {
+ std::string block_device = GetBlockDeviceForMountPoint("/data");
+ if (block_device.empty()) {
+ LERROR << "/data is not mounted";
+ return -1;
+ }
+ auto fstab_entry = GetMountedEntryForUserdata(fstab);
+ if (fstab_entry == nullptr) {
LERROR << "Can't find /data in fstab";
return -1;
}
- if (!entry->fs_mgr_flags.checkpoint_blk && !entry->fs_mgr_flags.checkpoint_fs) {
+ if (!fstab_entry->fs_mgr_flags.checkpoint_blk && !fstab_entry->fs_mgr_flags.checkpoint_fs) {
LINFO << "Userdata doesn't support checkpointing. Nothing to do";
return 0;
}
@@ -1373,34 +1393,43 @@
LINFO << "Checkpointing not needed. Don't remount";
return 0;
}
- if (entry->fs_mgr_flags.checkpoint_fs) {
+ bool force_umount_for_f2fs =
+ GetBoolProperty("sys.init.userdata_remount.force_umount_f2fs", false);
+ if (fstab_entry->fs_mgr_flags.checkpoint_fs && !force_umount_for_f2fs) {
// Userdata is f2fs, simply remount it.
- if (!checkpoint_manager.Update(&(*entry))) {
+ if (!checkpoint_manager.Update(fstab_entry)) {
LERROR << "Failed to remount userdata in checkpointing mode";
return -1;
}
- if (mount(entry->blk_device.c_str(), entry->mount_point.c_str(), "none",
- MS_REMOUNT | entry->flags, entry->fs_options.c_str()) != 0) {
+ if (mount(block_device.c_str(), fstab_entry->mount_point.c_str(), "none",
+ MS_REMOUNT | fstab_entry->flags, fstab_entry->fs_options.c_str()) != 0) {
PERROR << "Failed to remount userdata in checkpointing mode";
return -1;
}
} else {
- // STOPSHIP(b/143970043): support remounting for ext4 + metadata encryption.
- if (should_use_metadata_encryption(*entry)) {
- LWARNING << "Remounting into checkpointing is not supported for metadata encrypted "
- << "ext4 userdata. Proceed with caution";
- return 0;
- }
+ LINFO << "Unmounting /data before remounting into checkpointing mode";
if (umount2("/data", UMOUNT_NOFOLLOW) != 0) {
PERROR << "Failed to umount /data";
return -1;
}
DeviceMapper& dm = DeviceMapper::Instance();
- // TODO(b/143970043): need to delete every dm-device under the one userdata is mounted on.
- if (!dm.DeleteDeviceIfExists("bow")) {
- LERROR << "Failed to delete dm-bow";
- return -1;
+ while (dm.IsDmBlockDevice(block_device)) {
+ auto next_device = dm.GetParentBlockDeviceByPath(block_device);
+ auto name = dm.GetDmDeviceNameByPath(block_device);
+ if (!name) {
+ LERROR << "Failed to get dm-name for " << block_device;
+ return -1;
+ }
+ LINFO << "Deleting " << block_device << " named " << *name;
+ if (!dm.DeleteDevice(*name, 3s)) {
+ return -1;
+ }
+ if (!next_device) {
+ LERROR << "Failed to find parent device for " << block_device;
+ }
+ block_device = *next_device;
}
+ LINFO << "Remounting /data";
// TODO(b/143970043): remove this hack after fs_mgr_mount_all is refactored.
int result = fs_mgr_mount_all(fstab, MOUNT_MODE_ONLY_USERDATA);
return result == FS_MGR_MNTALL_FAIL ? -1 : 0;