Files
android_bootable_recovery/roots.cpp
Johan Harvyl 29dd6b6c01 Format formattable partitions if mount fails
If mount fails and the partition has the formattable flag set in fstab
it is formatted and another attempt at the mount is made.

Change-Id: I44edafac7d7ff663489072c66b7e210466316b14
2016-08-12 16:13:50 +02:00

272 lines
8.3 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 "roots.h"
#include <errno.h>
#include <stdlib.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <ctype.h>
#include <fcntl.h>
#include <fs_mgr.h>
#include "common.h"
#include "make_ext4fs.h"
#include "mounts.h"
#include "wipe.h"
#include "cryptfs.h"
static struct fstab *fstab = NULL;
extern struct selabel_handle *sehandle;
void load_volume_table()
{
int i;
int ret;
fstab = fs_mgr_read_fstab("/etc/recovery.fstab");
if (!fstab) {
LOGE("failed to read /etc/recovery.fstab\n");
return;
}
ret = fs_mgr_add_entry(fstab, "/tmp", "ramdisk", "ramdisk");
if (ret < 0 ) {
LOGE("failed to add /tmp entry to fstab\n");
fs_mgr_free_fstab(fstab);
fstab = NULL;
return;
}
printf("recovery filesystem table\n");
printf("=========================\n");
for (i = 0; i < fstab->num_entries; ++i) {
Volume* v = &fstab->recs[i];
printf(" %d %s %s %s %lld\n", i, v->mount_point, v->fs_type,
v->blk_device, v->length);
}
printf("\n");
}
Volume* volume_for_path(const char* path) {
return fs_mgr_get_entry_for_mount_point(fstab, path);
}
// Mount the volume specified by path at the given mount_point.
int ensure_path_mounted_at(const char* path, const char* mount_point) {
Volume* v = volume_for_path(path);
if (v == NULL) {
LOGE("unknown volume for path [%s]\n", path);
return -1;
}
if (strcmp(v->fs_type, "ramdisk") == 0) {
// the ramdisk is always mounted.
return 0;
}
if (!scan_mounted_volumes()) {
LOGE("failed to scan mounted volumes\n");
return -1;
}
if (!mount_point) {
mount_point = v->mount_point;
}
MountedVolume* mv = find_mounted_volume_by_mount_point(mount_point);
if (mv) {
// volume is already mounted
return 0;
}
mkdir(mount_point, 0755); // in case it doesn't already exist
if (strcmp(v->fs_type, "ext4") == 0 ||
strcmp(v->fs_type, "squashfs") == 0 ||
strcmp(v->fs_type, "vfat") == 0) {
int result = mount(v->blk_device, mount_point, v->fs_type, v->flags, v->fs_options);
if (result == -1 && fs_mgr_is_formattable(v)) {
LOGE("failed to mount %s (%s), formatting ...\n",
mount_point, strerror(errno));
bool crypt_footer = fs_mgr_is_encryptable(v) && !strcmp(v->key_loc, "footer");
if (fs_mgr_do_format(v, crypt_footer) == 0) {
result = mount(v->blk_device, mount_point, v->fs_type, v->flags, v->fs_options);
} else {
LOGE("failed to format %s (%s)\n", mount_point, strerror(errno));
return -1;
}
}
if (result == -1) {
LOGE("failed to mount %s (%s)\n", mount_point, strerror(errno));
return -1;
}
return 0;
}
LOGE("unknown fs_type \"%s\" for %s\n", v->fs_type, mount_point);
return -1;
}
int ensure_path_mounted(const char* path) {
// Mount at the default mount point.
return ensure_path_mounted_at(path, nullptr);
}
int ensure_path_unmounted(const char* path) {
Volume* v = volume_for_path(path);
if (v == NULL) {
LOGE("unknown volume for path [%s]\n", path);
return -1;
}
if (strcmp(v->fs_type, "ramdisk") == 0) {
// the ramdisk is always mounted; you can't unmount it.
return -1;
}
if (!scan_mounted_volumes()) {
LOGE("failed to scan mounted volumes\n");
return -1;
}
MountedVolume* mv = find_mounted_volume_by_mount_point(v->mount_point);
if (mv == NULL) {
// volume is already unmounted
return 0;
}
return unmount_mounted_volume(mv);
}
static int exec_cmd(const char* path, char* const argv[]) {
int status;
pid_t child;
if ((child = vfork()) == 0) {
execv(path, argv);
_exit(-1);
}
waitpid(child, &status, 0);
if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
LOGE("%s failed with status %d\n", path, WEXITSTATUS(status));
}
return WEXITSTATUS(status);
}
int format_volume(const char* volume) {
Volume* v = volume_for_path(volume);
if (v == NULL) {
LOGE("unknown volume \"%s\"\n", volume);
return -1;
}
if (strcmp(v->fs_type, "ramdisk") == 0) {
// you can't format the ramdisk.
LOGE("can't format_volume \"%s\"", volume);
return -1;
}
if (strcmp(v->mount_point, volume) != 0) {
LOGE("can't give path \"%s\" to format_volume\n", volume);
return -1;
}
if (ensure_path_unmounted(volume) != 0) {
LOGE("format_volume failed to unmount \"%s\"\n", v->mount_point);
return -1;
}
if (strcmp(v->fs_type, "ext4") == 0 || strcmp(v->fs_type, "f2fs") == 0) {
// if there's a key_loc that looks like a path, it should be a
// block device for storing encryption metadata. wipe it too.
if (v->key_loc != NULL && v->key_loc[0] == '/') {
LOGI("wiping %s\n", v->key_loc);
int fd = open(v->key_loc, O_WRONLY | O_CREAT, 0644);
if (fd < 0) {
LOGE("format_volume: failed to open %s\n", v->key_loc);
return -1;
}
wipe_block_device(fd, get_file_size(fd));
close(fd);
}
ssize_t length = 0;
if (v->length != 0) {
length = v->length;
} else if (v->key_loc != NULL && strcmp(v->key_loc, "footer") == 0) {
length = -CRYPT_FOOTER_OFFSET;
}
int result;
if (strcmp(v->fs_type, "ext4") == 0) {
result = make_ext4fs(v->blk_device, length, volume, sehandle);
} else { /* Has to be f2fs because we checked earlier. */
if (v->key_loc != NULL && strcmp(v->key_loc, "footer") == 0 && length < 0) {
LOGE("format_volume: crypt footer + negative length (%zd) not supported on %s\n", length, v->fs_type);
return -1;
}
if (length < 0) {
LOGE("format_volume: negative length (%zd) not supported on %s\n", length, v->fs_type);
return -1;
}
char *num_sectors;
if (asprintf(&num_sectors, "%zd", length / 512) <= 0) {
LOGE("format_volume: failed to create %s command for %s\n", v->fs_type, v->blk_device);
return -1;
}
const char *f2fs_path = "/sbin/mkfs.f2fs";
const char* const f2fs_argv[] = {"mkfs.f2fs", "-t", "-d1", v->blk_device, num_sectors, NULL};
result = exec_cmd(f2fs_path, (char* const*)f2fs_argv);
free(num_sectors);
}
if (result != 0) {
LOGE("format_volume: make %s failed on %s with %d(%s)\n", v->fs_type, v->blk_device, result, strerror(errno));
return -1;
}
return 0;
}
LOGE("format_volume: fs_type \"%s\" unsupported\n", v->fs_type);
return -1;
}
int setup_install_mounts() {
if (fstab == NULL) {
LOGE("can't set up install mounts: no fstab loaded\n");
return -1;
}
for (int i = 0; i < fstab->num_entries; ++i) {
Volume* v = fstab->recs + i;
if (strcmp(v->mount_point, "/tmp") == 0 ||
strcmp(v->mount_point, "/cache") == 0) {
if (ensure_path_mounted(v->mount_point) != 0) {
LOGE("failed to mount %s\n", v->mount_point);
return -1;
}
} else {
if (ensure_path_unmounted(v->mount_point) != 0) {
LOGE("failed to unmount %s\n", v->mount_point);
return -1;
}
}
}
return 0;
}