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/*
* 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.
*/
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <linux/fs.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <linux/kdev_t.h>
#include <android-base/logging.h>
#include <android-base/stringprintf.h>
#include <selinux/selinux.h>
#include <logwrap/logwrap.h>
#include "Utils.h"
#include "Vfat.h"
#include "VoldUtil.h"
using android::base::StringPrintf;
namespace android {
namespace vold {
namespace vfat {
static const char* kMkfsPath = "/system/bin/newfs_msdos";
static const char* kFsckPath = "/system/bin/fsck_msdos";
bool IsSupported() {
return access(kMkfsPath, X_OK) == 0 && access(kFsckPath, X_OK) == 0 &&
IsFilesystemSupported("vfat");
}
status_t Check(const std::string& source) {
int pass = 1;
int rc = 0;
do {
std::vector<std::string> cmd;
cmd.push_back(kFsckPath);
cmd.push_back("-p");
cmd.push_back("-f");
cmd.push_back("-y");
cmd.push_back(source);
// Fat devices are currently always untrusted
rc = ForkExecvp(cmd, nullptr, sFsckUntrustedContext);
if (rc < 0) {
LOG(ERROR) << "Filesystem check failed due to logwrap error";
errno = EIO;
return -1;
}
switch (rc) {
case 0:
LOG(INFO) << "Filesystem check completed OK";
return 0;
case 2:
LOG(ERROR) << "Filesystem check failed (not a FAT filesystem)";
errno = ENODATA;
return -1;
case 4:
if (pass++ <= 3) {
LOG(WARNING) << "Filesystem modified - rechecking (pass " << pass << ")";
continue;
}
LOG(ERROR) << "Failing check after too many rechecks";
errno = EIO;
return -1;
case 8:
LOG(ERROR) << "Filesystem check failed (no filesystem)";
errno = ENODATA;
return -1;
default:
LOG(ERROR) << "Filesystem check failed (unknown exit code " << rc << ")";
errno = EIO;
return -1;
}
} while (0);
return 0;
}
status_t Mount(const std::string& source, const std::string& target, bool ro, bool remount,
bool executable, int ownerUid, int ownerGid, int permMask, bool createLost) {
int rc;
unsigned long flags;
const char* c_source = source.c_str();
const char* c_target = target.c_str();
flags = MS_NODEV | MS_NOSUID | MS_DIRSYNC | MS_NOATIME;
flags |= (executable ? 0 : MS_NOEXEC);
flags |= (ro ? MS_RDONLY : 0);
flags |= (remount ? MS_REMOUNT : 0);
auto mountData =
android::base::StringPrintf("utf8,uid=%d,gid=%d,fmask=%o,dmask=%o,shortname=mixed",
ownerUid, ownerGid, permMask, permMask);
rc = mount(c_source, c_target, "vfat", flags, mountData.c_str());
if (rc && errno == EROFS) {
LOG(ERROR) << source << " appears to be a read only filesystem - retrying mount RO";
flags |= MS_RDONLY;
rc = mount(c_source, c_target, "vfat", flags, mountData.c_str());
}
if (rc == 0 && createLost) {
auto lost_path = android::base::StringPrintf("%s/LOST.DIR", target.c_str());
if (access(lost_path.c_str(), F_OK)) {
/*
* Create a LOST.DIR in the root so we have somewhere to put
* lost cluster chains (fsck_msdos doesn't currently do this)
*/
if (mkdir(lost_path.c_str(), 0755)) {
PLOG(ERROR) << "Unable to create LOST.DIR";
}
}
}
return rc;
}
status_t Format(const std::string& source, unsigned long numSectors) {
std::vector<std::string> cmd;
cmd.push_back(kMkfsPath);
cmd.push_back("-O");
cmd.push_back("android");
cmd.push_back("-A");
if (numSectors) {
cmd.push_back("-s");
cmd.push_back(StringPrintf("%lu", numSectors));
}
cmd.push_back(source);
int rc = ForkExecvp(cmd);
if (rc < 0) {
LOG(ERROR) << "Filesystem format failed due to logwrap error";
errno = EIO;
return -1;
}
if (rc == 0) {
LOG(INFO) << "Filesystem formatted OK";
return 0;
} else {
LOG(ERROR) << "Format failed (unknown exit code " << rc << ")";
errno = EIO;
return -1;
}
return 0;
}
} // namespace vfat
} // namespace vold
} // namespace android