Support preserving assembly/runtime files
When using overlays, they are placed in cuttlefish_runtime which causes
them to be deleted on every invocation of launch_cvd. This change allows
preserving some files in cuttlefish_assembly and cuttlefish_runtime
between invocations.
Test: launch_cvd --num_instances=2, modify /data, re-launch
Bug: 148242646
Change-Id: Ibd5ba2969da4f2653e9122a91259e332ade9f342
diff --git a/host/commands/assemble_cvd/flags.cc b/host/commands/assemble_cvd/flags.cc
index 6d8e170..5e9cb57 100644
--- a/host/commands/assemble_cvd/flags.cc
+++ b/host/commands/assemble_cvd/flags.cc
@@ -1,6 +1,10 @@
#include "host/commands/assemble_cvd/flags.h"
+#include <dirent.h>
+#include <sys/types.h>
+#include <sys/stat.h>
#include <sys/statvfs.h>
+#include <unistd.h>
#include <algorithm>
#include <iostream>
@@ -161,6 +165,11 @@
"bootloader. It will default to 'a' if empty and not using a "
"bootloader.");
DEFINE_int32(num_instances, 1, "Number of Android guests to launch");
+DEFINE_bool(resume, true, "Resume using the disk from the last session, if "
+ "possible. i.e., if --noresume is passed, the disk "
+ "will be reset to the state it was initially launched "
+ "in. This flag is ignored if the underlying partition "
+ "images have been updated since the first launch.");
namespace {
@@ -459,8 +468,77 @@
return ResolveInstanceFiles();
}
-bool CleanPriorFiles(const std::vector<std::string>& paths) {
- std::string prior_files = android::base::Join(paths, " ");
+std::string cpp_basename(const std::string& str) {
+ char* copy = strdup(str.c_str()); // basename may modify its argument
+ std::string ret(basename(copy));
+ free(copy);
+ return ret;
+}
+
+bool CleanPriorFiles(const std::string& path, const std::set<std::string>& preserving) {
+ if (preserving.count(cpp_basename(path))) {
+ LOG(INFO) << "Preserving: " << path;
+ return true;
+ }
+ struct stat statbuf;
+ if (lstat(path.c_str(), &statbuf) < 0) {
+ int error_num = errno;
+ if (error_num == ENOENT) {
+ return true;
+ } else {
+ LOG(ERROR) << "Could not stat \"" << path << "\": " << strerror(error_num);
+ return false;
+ }
+ }
+ if ((statbuf.st_mode & S_IFMT) != S_IFDIR) {
+ LOG(INFO) << "Deleting: " << path;
+ if (unlink(path.c_str()) < 0) {
+ int error_num = errno;
+ LOG(ERROR) << "Could not unlink \"" << path << "\", error was " << strerror(error_num);
+ return false;
+ }
+ return true;
+ }
+ std::unique_ptr<DIR, int(*)(DIR*)> dir(opendir(path.c_str()), closedir);
+ if (!dir) {
+ int error_num = errno;
+ LOG(ERROR) << "Could not clean \"" << path << "\": error was " << strerror(error_num);
+ return false;
+ }
+ for (auto entity = readdir(dir.get()); entity != nullptr; entity = readdir(dir.get())) {
+ std::string entity_name(entity->d_name);
+ if (entity_name == "." || entity_name == "..") {
+ continue;
+ }
+ std::string entity_path = path + "/" + entity_name;
+ if (!CleanPriorFiles(entity_path.c_str(), preserving)) {
+ return false;
+ }
+ }
+ if (rmdir(path.c_str()) < 0) {
+ if (!(errno == EEXIST || errno == ENOTEMPTY)) {
+ // If EEXIST or ENOTEMPTY, probably because a file was preserved
+ int error_num = errno;
+ LOG(ERROR) << "Could not rmdir \"" << path << "\", error was " << strerror(error_num);
+ return false;
+ }
+ }
+ return true;
+}
+
+bool CleanPriorFiles(const std::vector<std::string>& paths, const std::set<std::string>& preserving) {
+ std::string prior_files;
+ for (auto path : paths) {
+ struct stat statbuf;
+ if (stat(path.c_str(), &statbuf) < 0 && errno != ENOENT) {
+ // If ENOENT, it doesn't exist yet, so there is no work to do'
+ int error_num = errno;
+ LOG(ERROR) << "Could not stat \"" << path << "\": " << strerror(error_num);
+ return false;
+ }
+ bool is_directory = (statbuf.st_mode & S_IFMT) == S_IFDIR;
+ prior_files += (is_directory ? (path + "/*") : path) + " ";
+ }
LOG(INFO) << "Assuming prior files of " << prior_files;
std::string lsof_cmd = "lsof -t " + prior_files + " >/dev/null 2>&1";
int rval = std::system(lsof_cmd.c_str());
@@ -469,19 +547,19 @@
LOG(ERROR) << "Clean aborted: files are in use";
return false;
}
- std::string clean_command = "rm -rf " + prior_files;
- rval = std::system(clean_command.c_str());
- if (WEXITSTATUS(rval) != 0) {
- LOG(ERROR) << "Remove of files failed";
- return false;
+ for (const auto& path : paths) {
+ if (!CleanPriorFiles(path, preserving)) {
+ LOG(ERROR) << "Remove of file under \"" << path << "\" failed";
+ return false;
+ }
}
return true;
}
-bool CleanPriorFiles(const vsoc::CuttlefishConfig& config) {
+bool CleanPriorFiles(const vsoc::CuttlefishConfig& config, const std::set<std::string>& preserving) {
std::vector<std::string> paths = {
// Everything in the assembly directory
- FLAGS_assembly_dir + "/*",
+ FLAGS_assembly_dir,
// The environment file
GetCuttlefishEnvPath(),
// The global link to the config file
@@ -490,7 +568,7 @@
for (const auto& instance : config.Instances()) {
paths.push_back(instance.instance_dir());
}
- return CleanPriorFiles(paths);
+ return CleanPriorFiles(paths, preserving);
}
bool DecompressKernel(const std::string& src, const std::string& dst) {
@@ -548,23 +626,20 @@
return partitions;
}
-bool ShouldCreateCompositeDisk() {
- if (FLAGS_vm_manager == vm_manager::CrosvmManager::name()) {
- // The crosvm implementation is very fast to rebuild but also more brittle due to being split
- // into multiple files. The QEMU implementation is slow to build, but completely self-contained
- // at that point. Therefore, always rebuild on crosvm but check if it is necessary for QEMU.
- return true;
- }
- auto composite_age = cvd::FileModificationTime(FLAGS_composite_disk);
+std::chrono::system_clock::time_point LastUpdatedInputDisk() {
+ std::chrono::system_clock::time_point ret;
for (auto& partition : disk_config()) {
- auto partition_age = cvd::FileModificationTime(partition.image_file_path);
- if (partition_age >= composite_age) {
- LOG(INFO) << "composite disk age was \"" << std::chrono::system_clock::to_time_t(composite_age) << "\", "
- << "partition age was \"" << std::chrono::system_clock::to_time_t(partition_age) << "\"";
- return true;
+ auto partition_mod_time = cvd::FileModificationTime(partition.image_file_path);
+ if (partition_mod_time > ret) {
+ ret = partition_mod_time;
}
}
- return false;
+ return ret;
+}
+
+bool ShouldCreateCompositeDisk() {
+ auto composite_age = cvd::FileModificationTime(FLAGS_composite_disk);
+ return composite_age < LastUpdatedInputDisk();
}
bool ConcatRamdisks(const std::string& new_ramdisk_path, const std::string& ramdisk_a_path,
@@ -618,10 +693,6 @@
std::string header_path = config.AssemblyPath("gpt_header.img");
std::string footer_path = config.AssemblyPath("gpt_footer.img");
CreateCompositeDisk(disk_config(), header_path, footer_path, FLAGS_composite_disk);
- for (auto instance : config.Instances()) {
- auto overlay_path = instance.PerInstancePath("overlay.img");
- CreateQcowOverlay(config.crosvm_binary(), FLAGS_composite_disk, overlay_path);
- }
} else {
auto existing_size = cvd::FileSize(FLAGS_composite_disk);
auto available_space = AvailableSpaceAtPath(FLAGS_composite_disk);
@@ -654,14 +725,27 @@
// two operations, as those will assume they can read the config object from
// disk.
auto config = InitializeCuttlefishConfiguration(*boot_img_unpacker, fetcher_config);
- if (!CleanPriorFiles(config)) {
+ std::set<std::string> preserving;
+ if (FLAGS_resume && ShouldCreateCompositeDisk()) {
+ LOG(WARNING) << "Requested resuming a previous session (the default behavior) "
+ << "but the base images have changed under the overlay, making the "
+ << "overlay incompatible. Wiping the overlay files.";
+ } else if (FLAGS_resume && !ShouldCreateCompositeDisk()) {
+ preserving.insert("overlay.img");
+ preserving.insert("gpt_header.img");
+ preserving.insert("gpt_footer.img");
+ preserving.insert("composite.img");
+ preserving.insert("access-kregistry");
+ }
+ if (!CleanPriorFiles(config, preserving)) {
LOG(ERROR) << "Failed to clean prior files";
exit(AssemblerExitCodes::kPrioFilesCleanupError);
}
// Create assembly directory if it doesn't exist.
if (!cvd::DirectoryExists(FLAGS_assembly_dir.c_str())) {
LOG(INFO) << "Setting up " << FLAGS_assembly_dir;
- if (mkdir(FLAGS_assembly_dir.c_str(), S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH) < 0) {
+ if (mkdir(FLAGS_assembly_dir.c_str(), S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH) < 0
+ && errno != EEXIST) {
LOG(ERROR) << "Failed to create assembly directory: "
<< FLAGS_assembly_dir << ". Error: " << errno;
exit(AssemblerExitCodes::kAssemblyDirCreationError);
@@ -671,7 +755,8 @@
// Create instance directory if it doesn't exist.
if (!cvd::DirectoryExists(instance.instance_dir().c_str())) {
LOG(INFO) << "Setting up " << FLAGS_instance_dir << ".N";
- if (mkdir(instance.instance_dir().c_str(), S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH) < 0) {
+ if (mkdir(instance.instance_dir().c_str(), S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH) < 0
+ && errno != EEXIST) {
LOG(ERROR) << "Failed to create instance directory: "
<< FLAGS_instance_dir << ". Error: " << errno;
exit(AssemblerExitCodes::kInstanceDirCreationError);
@@ -679,8 +764,8 @@
}
auto internal_dir = instance.instance_dir() + "/" + vsoc::kInternalDirName;
if (!cvd::DirectoryExists(internal_dir)) {
- if (mkdir(internal_dir.c_str(), S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH) <
- 0) {
+ if (mkdir(internal_dir.c_str(), S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH) < 0
+ && errno != EEXIST) {
LOG(ERROR) << "Failed to create internal instance directory: "
<< internal_dir << ". Error: " << errno;
exit(AssemblerExitCodes::kInstanceDirCreationError);
@@ -791,6 +876,19 @@
}
for (auto instance : config->Instances()) {
+ auto overlay_path = instance.PerInstancePath("overlay.img");
+ if (!cvd::FileExists(overlay_path) || ShouldCreateCompositeDisk() || !FLAGS_resume
+ || cvd::FileModificationTime(overlay_path) < cvd::FileModificationTime(FLAGS_composite_disk)) {
+ if (FLAGS_resume) {
+ LOG(WARNING) << "Requested to continue an existing session, but the overlay was "
+ << "newer than its underlying composite disk. Wiping the overlay.";
+ }
+ CreateQcowOverlay(config->crosvm_binary(), FLAGS_composite_disk, overlay_path);
+ CreateBlankImage(instance.access_kregistry_path(), 1, "none", "64K");
+ }
+ }
+
+ for (auto instance : config->Instances()) {
// Check that the files exist
for (const auto& file : instance.virtual_disk_paths()) {
if (!file.empty() && !cvd::FileHasContent(file.c_str())) {
