blob: 4c867883eb4a0704006f42dca386c1488461d8ea [file] [log] [blame]
/*
* Copyright (C) 2008 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.
*/
#define ATRACE_TAG ATRACE_TAG_PACKAGE_MANAGER
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <linux/kdev_t.h>
#include <chrono>
#include <android-base/logging.h>
#include <android-base/stringprintf.h>
#include <android-base/strings.h>
#include <android-base/unique_fd.h>
#include <fs_mgr/file_wait.h>
#include <utils/Trace.h>
#include "Loop.h"
#include "VoldUtil.h"
#include "sehandle.h"
using namespace std::literals;
using android::base::StringPrintf;
using android::base::unique_fd;
static const char* kVoldPrefix = "vold:";
static constexpr size_t kLoopDeviceRetryAttempts = 3u;
int Loop::create(const std::string& target, std::string& out_device) {
unique_fd ctl_fd(open("/dev/loop-control", O_RDWR | O_CLOEXEC));
if (ctl_fd.get() == -1) {
PLOG(ERROR) << "Failed to open loop-control";
return -errno;
}
int num = ioctl(ctl_fd.get(), LOOP_CTL_GET_FREE);
if (num == -1) {
PLOG(ERROR) << "Failed LOOP_CTL_GET_FREE";
return -errno;
}
out_device = StringPrintf("/dev/block/loop%d", num);
unique_fd target_fd;
for (size_t i = 0; i != kLoopDeviceRetryAttempts; ++i) {
target_fd.reset(open(target.c_str(), O_RDWR | O_CLOEXEC));
if (target_fd.get() != -1) {
break;
}
usleep(50000);
}
if (target_fd.get() == -1) {
PLOG(ERROR) << "Failed to open " << target;
return -errno;
}
if (!android::fs_mgr::WaitForFile(out_device, 2s)) {
LOG(ERROR) << "Failed to find " << out_device;
return -ENOENT;
}
unique_fd device_fd(open(out_device.c_str(), O_RDWR | O_CLOEXEC));
if (device_fd.get() == -1) {
PLOG(ERROR) << "Failed to open " << out_device;
return -errno;
}
if (ioctl(device_fd.get(), LOOP_SET_FD, target_fd.get()) == -1) {
PLOG(ERROR) << "Failed to LOOP_SET_FD";
return -errno;
}
struct loop_info64 li;
memset(&li, 0, sizeof(li));
strlcpy((char*)li.lo_crypt_name, kVoldPrefix, LO_NAME_SIZE);
if (ioctl(device_fd.get(), LOOP_SET_STATUS64, &li) == -1) {
PLOG(ERROR) << "Failed to LOOP_SET_STATUS64";
return -errno;
}
return 0;
}
int Loop::destroyByDevice(const char* loopDevice) {
int device_fd;
device_fd = open(loopDevice, O_RDONLY | O_CLOEXEC);
if (device_fd < 0) {
PLOG(ERROR) << "Failed to open " << loopDevice;
return -1;
}
if (ioctl(device_fd, LOOP_CLR_FD, 0) < 0) {
PLOG(ERROR) << "Failed to destroy " << loopDevice;
close(device_fd);
return -1;
}
close(device_fd);
return 0;
}
int Loop::destroyAll() {
ATRACE_NAME("Loop::destroyAll");
std::string root = "/dev/block/";
auto dirp = std::unique_ptr<DIR, int (*)(DIR*)>(opendir(root.c_str()), closedir);
if (!dirp) {
PLOG(ERROR) << "Failed to opendir";
return -1;
}
// Poke through all devices looking for loops
struct dirent* de;
while ((de = readdir(dirp.get()))) {
auto test = std::string(de->d_name);
if (!android::base::StartsWith(test, "loop")) continue;
auto path = root + de->d_name;
unique_fd fd(open(path.c_str(), O_RDWR | O_CLOEXEC));
if (fd.get() == -1) {
if (errno != ENOENT) {
PLOG(WARNING) << "Failed to open " << path;
}
continue;
}
struct loop_info64 li;
if (ioctl(fd.get(), LOOP_GET_STATUS64, &li) < 0) {
if (errno != ENXIO) {
PLOG(WARNING) << "Failed to LOOP_GET_STATUS64 " << path;
}
continue;
}
auto id = std::string((char*)li.lo_crypt_name);
if (android::base::StartsWith(id, kVoldPrefix)) {
LOG(DEBUG) << "Tearing down stale loop device at " << path << " named " << id;
if (ioctl(fd.get(), LOOP_CLR_FD, 0) < 0) {
PLOG(WARNING) << "Failed to LOOP_CLR_FD " << path;
}
}
}
return 0;
}
int Loop::createImageFile(const char* file, unsigned long numSectors) {
unique_fd fd(open(file, O_CREAT | O_WRONLY | O_TRUNC | O_CLOEXEC, 0600));
if (fd.get() == -1) {
PLOG(ERROR) << "Failed to create image " << file;
return -errno;
}
if (fallocate(fd.get(), 0, 0, numSectors * 512) == -1) {
PLOG(WARNING) << "Failed to fallocate; falling back to ftruncate";
if (ftruncate(fd, numSectors * 512) == -1) {
PLOG(ERROR) << "Failed to ftruncate";
return -errno;
}
}
return 0;
}
int Loop::resizeImageFile(const char* file, unsigned long numSectors) {
int fd;
if ((fd = open(file, O_RDWR | O_CLOEXEC)) < 0) {
PLOG(ERROR) << "Failed to open " << file;
return -1;
}
LOG(DEBUG) << "Attempting to increase " << file << " to " << numSectors;
if (fallocate(fd, 0, 0, numSectors * 512)) {
if (errno == ENOSYS || errno == ENOTSUP) {
PLOG(WARNING) << "fallocate not found. Falling back to ftruncate.";
if (ftruncate(fd, numSectors * 512) < 0) {
PLOG(ERROR) << "Failed to ftruncate";
close(fd);
return -1;
}
} else {
PLOG(ERROR) << "Failed to fallocate";
close(fd);
return -1;
}
}
close(fd);
return 0;
}