/*
* Copyright (C) 2010 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <dirent.h>
#include <errno.h>
#include <inttypes.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/statfs.h>
#include <unistd.h>
#include <algorithm>
#include <limits>
#include <memory>
#include <set>
#include <string>
#include <android-base/file.h>
#include <android-base/logging.h>
#include <android-base/parseint.h>
#include <android-base/stringprintf.h>
#include <android-base/strings.h>
#include "applypatch/applypatch.h"
#include "otautil/paths.h"
static int EliminateOpenFiles(const std::string& dirname, std::set<std::string>* files) {
std::unique_ptr<DIR, decltype(&closedir)> d(opendir("/proc"), closedir);
if (!d) {
PLOG(ERROR) << "Failed to open /proc";
return -1;
}
struct dirent* de;
while ((de = readdir(d.get())) != 0) {
unsigned int pid;
if (!android::base::ParseUint(de->d_name, &pid)) {
continue;
}
std::string path = android::base::StringPrintf("/proc/%s/fd/", de->d_name);
struct dirent* fdde;
std::unique_ptr<DIR, decltype(&closedir)> fdd(opendir(path.c_str()), closedir);
if (!fdd) {
PLOG(ERROR) << "Failed to open " << path;
continue;
}
while ((fdde = readdir(fdd.get())) != 0) {
std::string fd_path = path + fdde->d_name;
char link[FILENAME_MAX];
int count = readlink(fd_path.c_str(), link, sizeof(link)-1);
if (count >= 0) {
link[count] = '\0';
if (android::base::StartsWith(link, dirname)) {
if (files->erase(link) > 0) {
LOG(INFO) << link << " is open by " << de->d_name;
}
}
}
}
}
return 0;
}
static std::vector<std::string> FindExpendableFiles(
const std::string& dirname, const std::function<bool(const std::string&)>& name_filter) {
std::unique_ptr<DIR, decltype(&closedir)> d(opendir(dirname.c_str()), closedir);
if (!d) {
PLOG(ERROR) << "Failed to open " << dirname;
return {};
}
// Look for regular files in the directory (not in any subdirectories).
std::set<std::string> files;
struct dirent* de;
while ((de = readdir(d.get())) != 0) {
std::string path = dirname + "/" + de->d_name;
// We can't delete cache_temp_source; if it's there we might have restarted during
// installation and could be depending on it to be there.
if (path == Paths::Get().cache_temp_source()) {
continue;
}
// Do not delete the file if it doesn't have the expected format.
if (name_filter != nullptr && !name_filter(de->d_name)) {
continue;
}
struct stat st;
if (stat(path.c_str(), &st) == 0 && S_ISREG(st.st_mode)) {
files.insert(path);
}
}
LOG(INFO) << files.size() << " regular files in deletable directory";
if (EliminateOpenFiles(dirname, &files) < 0) {
return {};
}
return std::vector<std::string>(files.begin(), files.end());
}
// Parses the index of given log file, e.g. 3 for last_log.3; returns max number if the log name
// doesn't have the expected format so that we'll delete these ones first.
static unsigned int GetLogIndex(const std::string& log_name) {
if (log_name == "last_log" || log_name == "last_kmsg") {
return 0;
}
unsigned int index;
if (sscanf(log_name.c_str(), "last_log.%u", &index) == 1 ||
sscanf(log_name.c_str(), "last_kmsg.%u", &index) == 1) {
return index;
}
return std::numeric_limits<unsigned int>::max();
}
// Returns the amount of free space (in bytes) on the filesystem containing filename, or -1 on
// error.
static int64_t FreeSpaceForFile(const std::string& filename) {
struct statfs sf;
if (statfs(filename.c_str(), &sf) == -1) {
PLOG(ERROR) << "Failed to statfs " << filename;
return -1;
}
auto f_bsize = static_cast<int64_t>(sf.f_bsize);
auto free_space = sf.f_bsize * sf.f_bavail;
if (f_bsize == 0 || free_space / f_bsize != static_cast<int64_t>(sf.f_bavail)) {
LOG(ERROR) << "Invalid block size or overflow (sf.f_bsize " << sf.f_bsize << ", sf.f_bavail "
<< sf.f_bavail << ")";
return -1;
}
return free_space;
}
bool CheckAndFreeSpaceOnCache(size_t bytes) {
#ifndef __ANDROID__
// TODO(xunchang): Implement a heuristic cache size check during host simulation.
LOG(WARNING) << "Skipped making (" << bytes
<< ") bytes free space on /cache; program is running on host";
return true;
#endif
std::vector<std::string> dirs{ "/cache", Paths::Get().cache_log_directory() };
for (const auto& dirname : dirs) {
if (RemoveFilesInDirectory(bytes, dirname, FreeSpaceForFile)) {
return true;
}
}
return false;
}
bool RemoveFilesInDirectory(size_t bytes_needed, const std::string& dirname,
const std::function<int64_t(const std::string&)>& space_checker) {
// The requested size cannot exceed max int64_t.
if (static_cast<uint64_t>(bytes_needed) >
static_cast<uint64_t>(std::numeric_limits<int64_t>::max())) {
LOG(ERROR) << "Invalid arg of bytes_needed: " << bytes_needed;
return false;
}
struct stat st;
if (stat(dirname.c_str(), &st) == -1) {
PLOG(ERROR) << "Failed to stat " << dirname;
return false;
}
if (!S_ISDIR(st.st_mode)) {
LOG(ERROR) << dirname << " is not a directory";
return false;
}
int64_t free_now = space_checker(dirname);
if (free_now == -1) {
LOG(ERROR) << "Failed to check free space for " << dirname;
return false;
}
LOG(INFO) << free_now << " bytes free on " << dirname << " (" << bytes_needed << " needed)";
if (free_now >= static_cast<int64_t>(bytes_needed)) {
return true;
}
std::vector<std::string> files;
if (dirname == Paths::Get().cache_log_directory()) {
// Deletes the log files only.
auto log_filter = [](const std::string& file_name) {
return android::base::StartsWith(file_name, "last_log") ||
android::base::StartsWith(file_name, "last_kmsg");
};
files = FindExpendableFiles(dirname, log_filter);
// Older logs will come to the top of the queue.
auto comparator = [](const std::string& name1, const std::string& name2) -> bool {
unsigned int index1 = GetLogIndex(android::base::Basename(name1));
unsigned int index2 = GetLogIndex(android::base::Basename(name2));
if (index1 == index2) {
return name1 < name2;
}
return index1 > index2;
};
std::sort(files.begin(), files.end(), comparator);
} else {
// We're allowed to delete unopened regular files in the directory.
files = FindExpendableFiles(dirname, nullptr);
}
for (const auto& file : files) {
if (unlink(file.c_str()) == -1) {
PLOG(ERROR) << "Failed to delete " << file;
continue;
}
free_now = space_checker(dirname);
if (free_now == -1) {
LOG(ERROR) << "Failed to check free space for " << dirname;
return false;
}
LOG(INFO) << "Deleted " << file << "; now " << free_now << " bytes free";
if (free_now >= static_cast<int64_t>(bytes_needed)) {
return true;
}
}
return false;
}
