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-rw-r--r--roots.cpp282
1 files changed, 282 insertions, 0 deletions
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+/*
+ * 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 <errno.h>
+#include <stdlib.h>
+#include <sys/mount.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <ctype.h>
+
+#include "mtdutils/mtdutils.h"
+#include "mtdutils/mounts.h"
+#include "roots.h"
+#include "common.h"
+#include "make_ext4fs.h"
+
+static int num_volumes = 0;
+static Volume* device_volumes = NULL;
+
+static int parse_options(char* options, Volume* volume) {
+ char* option;
+ while ((option = strtok(options, ","))) {
+ options = NULL;
+
+ if (strncmp(option, "length=", 7) == 0) {
+ volume->length = strtoll(option+7, NULL, 10);
+ } else {
+ LOGE("bad option \"%s\"\n", option);
+ return -1;
+ }
+ }
+ return 0;
+}
+
+void load_volume_table() {
+ int alloc = 2;
+ device_volumes = (Volume*)malloc(alloc * sizeof(Volume));
+
+ // Insert an entry for /tmp, which is the ramdisk and is always mounted.
+ device_volumes[0].mount_point = "/tmp";
+ device_volumes[0].fs_type = "ramdisk";
+ device_volumes[0].device = NULL;
+ device_volumes[0].device2 = NULL;
+ device_volumes[0].length = 0;
+ num_volumes = 1;
+
+ FILE* fstab = fopen("/etc/recovery.fstab", "r");
+ if (fstab == NULL) {
+ LOGE("failed to open /etc/recovery.fstab (%s)\n", strerror(errno));
+ return;
+ }
+
+ char buffer[1024];
+ int i;
+ while (fgets(buffer, sizeof(buffer)-1, fstab)) {
+ for (i = 0; buffer[i] && isspace(buffer[i]); ++i);
+ if (buffer[i] == '\0' || buffer[i] == '#') continue;
+
+ char* original = strdup(buffer);
+
+ char* mount_point = strtok(buffer+i, " \t\n");
+ char* fs_type = strtok(NULL, " \t\n");
+ char* device = strtok(NULL, " \t\n");
+ // lines may optionally have a second device, to use if
+ // mounting the first one fails.
+ char* options = NULL;
+ char* device2 = strtok(NULL, " \t\n");
+ if (device2) {
+ if (device2[0] == '/') {
+ options = strtok(NULL, " \t\n");
+ } else {
+ options = device2;
+ device2 = NULL;
+ }
+ }
+
+ if (mount_point && fs_type && device) {
+ while (num_volumes >= alloc) {
+ alloc *= 2;
+ device_volumes = (Volume*)realloc(device_volumes, alloc*sizeof(Volume));
+ }
+ device_volumes[num_volumes].mount_point = strdup(mount_point);
+ device_volumes[num_volumes].fs_type = strdup(fs_type);
+ device_volumes[num_volumes].device = strdup(device);
+ device_volumes[num_volumes].device2 =
+ device2 ? strdup(device2) : NULL;
+
+ device_volumes[num_volumes].length = 0;
+ if (parse_options(options, device_volumes + num_volumes) != 0) {
+ LOGE("skipping malformed recovery.fstab line: %s\n", original);
+ } else {
+ ++num_volumes;
+ }
+ } else {
+ LOGE("skipping malformed recovery.fstab line: %s\n", original);
+ }
+ free(original);
+ }
+
+ fclose(fstab);
+
+ printf("recovery filesystem table\n");
+ printf("=========================\n");
+ for (i = 0; i < num_volumes; ++i) {
+ Volume* v = &device_volumes[i];
+ printf(" %d %s %s %s %s %lld\n", i, v->mount_point, v->fs_type,
+ v->device, v->device2, v->length);
+ }
+ printf("\n");
+}
+
+Volume* volume_for_path(const char* path) {
+ int i;
+ for (i = 0; i < num_volumes; ++i) {
+ Volume* v = device_volumes+i;
+ int len = strlen(v->mount_point);
+ if (strncmp(path, v->mount_point, len) == 0 &&
+ (path[len] == '\0' || path[len] == '/')) {
+ return v;
+ }
+ }
+ return NULL;
+}
+
+int ensure_path_mounted(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.
+ return 0;
+ }
+
+ int result;
+ result = scan_mounted_volumes();
+ if (result < 0) {
+ LOGE("failed to scan mounted volumes\n");
+ return -1;
+ }
+
+ const MountedVolume* mv =
+ find_mounted_volume_by_mount_point(v->mount_point);
+ if (mv) {
+ // volume is already mounted
+ return 0;
+ }
+
+ mkdir(v->mount_point, 0755); // in case it doesn't already exist
+
+ if (strcmp(v->fs_type, "yaffs2") == 0) {
+ // mount an MTD partition as a YAFFS2 filesystem.
+ mtd_scan_partitions();
+ const MtdPartition* partition;
+ partition = mtd_find_partition_by_name(v->device);
+ if (partition == NULL) {
+ LOGE("failed to find \"%s\" partition to mount at \"%s\"\n",
+ v->device, v->mount_point);
+ return -1;
+ }
+ return mtd_mount_partition(partition, v->mount_point, v->fs_type, 0);
+ } else if (strcmp(v->fs_type, "ext4") == 0 ||
+ strcmp(v->fs_type, "vfat") == 0) {
+ result = mount(v->device, v->mount_point, v->fs_type,
+ MS_NOATIME | MS_NODEV | MS_NODIRATIME, "");
+ if (result == 0) return 0;
+
+ if (v->device2) {
+ LOGW("failed to mount %s (%s); trying %s\n",
+ v->device, strerror(errno), v->device2);
+ result = mount(v->device2, v->mount_point, v->fs_type,
+ MS_NOATIME | MS_NODEV | MS_NODIRATIME, "");
+ if (result == 0) return 0;
+ }
+
+ LOGE("failed to mount %s (%s)\n", v->mount_point, strerror(errno));
+ return -1;
+ }
+
+ LOGE("unknown fs_type \"%s\" for %s\n", v->fs_type, v->mount_point);
+ return -1;
+}
+
+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;
+ }
+
+ int result;
+ result = scan_mounted_volumes();
+ if (result < 0) {
+ LOGE("failed to scan mounted volumes\n");
+ return -1;
+ }
+
+ const 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);
+}
+
+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, "yaffs2") == 0 || strcmp(v->fs_type, "mtd") == 0) {
+ mtd_scan_partitions();
+ const MtdPartition* partition = mtd_find_partition_by_name(v->device);
+ if (partition == NULL) {
+ LOGE("format_volume: no MTD partition \"%s\"\n", v->device);
+ return -1;
+ }
+
+ MtdWriteContext *write = mtd_write_partition(partition);
+ if (write == NULL) {
+ LOGW("format_volume: can't open MTD \"%s\"\n", v->device);
+ return -1;
+ } else if (mtd_erase_blocks(write, -1) == (off_t) -1) {
+ LOGW("format_volume: can't erase MTD \"%s\"\n", v->device);
+ mtd_write_close(write);
+ return -1;
+ } else if (mtd_write_close(write)) {
+ LOGW("format_volume: can't close MTD \"%s\"\n", v->device);
+ return -1;
+ }
+ return 0;
+ }
+
+ if (strcmp(v->fs_type, "ext4") == 0) {
+ int result = make_ext4fs(v->device, v->length);
+ if (result != 0) {
+ LOGE("format_volume: make_extf4fs failed on %s\n", v->device);
+ return -1;
+ }
+ return 0;
+ }
+
+ LOGE("format_volume: fs_type \"%s\" unsupported\n", v->fs_type);
+ return -1;
+}