summaryrefslogtreecommitdiffstats
path: root/roots.cpp
blob: 9345cb0a29a0b136cc32071488f1f1e81355da76 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
/*
 * 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;
}