platform_bootable_recovery/mounts.cpp
Tao Bao 5f85d1fb0a Log the error message when failing to mount/umount.
Test: Observe the error messaage for a umount failure case.
Bug: 36686818
Change-Id: I28e335c2df4454dd0192f95e3909599fcc9dc1c0
2017-03-28 21:21:28 -07:00

99 lines
2.9 KiB
C++

/*
* Copyright (C) 2007 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 "mounts.h"
#include <errno.h>
#include <fcntl.h>
#include <mntent.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mount.h>
#include <string>
#include <vector>
#include <android-base/logging.h>
struct MountedVolume {
std::string device;
std::string mount_point;
std::string filesystem;
std::string flags;
};
std::vector<MountedVolume*> g_mounts_state;
bool scan_mounted_volumes() {
for (size_t i = 0; i < g_mounts_state.size(); ++i) {
delete g_mounts_state[i];
}
g_mounts_state.clear();
// Open and read mount table entries.
FILE* fp = setmntent("/proc/mounts", "re");
if (fp == NULL) {
return false;
}
mntent* e;
while ((e = getmntent(fp)) != NULL) {
MountedVolume* v = new MountedVolume;
v->device = e->mnt_fsname;
v->mount_point = e->mnt_dir;
v->filesystem = e->mnt_type;
v->flags = e->mnt_opts;
g_mounts_state.push_back(v);
}
endmntent(fp);
return true;
}
MountedVolume* find_mounted_volume_by_device(const char* device) {
for (size_t i = 0; i < g_mounts_state.size(); ++i) {
if (g_mounts_state[i]->device == device) return g_mounts_state[i];
}
return nullptr;
}
MountedVolume* find_mounted_volume_by_mount_point(const char* mount_point) {
for (size_t i = 0; i < g_mounts_state.size(); ++i) {
if (g_mounts_state[i]->mount_point == mount_point) return g_mounts_state[i];
}
return nullptr;
}
int unmount_mounted_volume(MountedVolume* volume) {
// Intentionally pass the empty string to umount if the caller tries to unmount a volume they
// already unmounted using this function.
std::string mount_point = volume->mount_point;
volume->mount_point.clear();
int result = umount(mount_point.c_str());
if (result == -1) {
PLOG(WARNING) << "Failed to umount " << mount_point;
}
return result;
}
int remount_read_only(MountedVolume* volume) {
int result = mount(volume->device.c_str(), volume->mount_point.c_str(),
volume->filesystem.c_str(),
MS_NOATIME | MS_NODEV | MS_NODIRATIME | MS_RDONLY | MS_REMOUNT, 0);
if (result == -1) {
PLOG(WARNING) << "Failed to remount read-only " << volume->mount_point;
}
return result;
}