libfstools: be more consistent with other existing code
[project/fstools.git] / libfstools / jffs2.c
1 /*
2 * Copyright (C) 2014 John Crispin <blogic@openwrt.org>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU Lesser General Public License version 2.1
6 * as published by the Free Software Foundation
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 */
13
14 #include <sys/stat.h>
15 #include <sys/types.h>
16 #include <sys/mount.h>
17
18 #include <asm/byteorder.h>
19
20 #include <errno.h>
21 #include <string.h>
22 #include <stdio.h>
23 #include <unistd.h>
24 #include <stdlib.h>
25 #include <glob.h>
26 #include <errno.h>
27 #include <dirent.h>
28 #include <fcntl.h>
29
30 #include "libfstools.h"
31 #include "volume.h"
32
33 #define SWITCH_JFFS2 "/tmp/.switch_jffs2"
34
35 void
36 foreachdir(const char *dir, int (*cb)(const char*))
37 {
38 char globdir[256];
39 glob_t gl;
40 int j;
41
42 if (dir[strlen(dir) - 1] == '/')
43 snprintf(globdir, 256, "%s*", dir);
44 else
45 snprintf(globdir, 256, "%s/*", dir);
46
47 if (!glob(globdir, GLOB_NOESCAPE | GLOB_MARK | GLOB_ONLYDIR, NULL, &gl))
48 for (j = 0; j < gl.gl_pathc; j++)
49 foreachdir(gl.gl_pathv[j], cb);
50
51 cb(dir);
52 }
53
54 static int
55 jffs2_mount(void)
56 {
57 struct volume *v;
58
59 if (mkdir("/tmp/overlay", 0755)) {
60 fprintf(stderr, "failed to mkdir /tmp/overlay: %s\n", strerror(errno));
61 return -1;
62 }
63
64 v = volume_find("rootfs_data");
65 if (!v) {
66 fprintf(stderr, "rootfs_data does not exist\n");
67 return -1;
68 }
69
70 if (mount(v->blk, "/tmp/overlay", "jffs2", MS_NOATIME, NULL)) {
71 fprintf(stderr, "failed to mount -t jffs2 %s /tmp/overlay: %s\n", v->blk, strerror(errno));
72 return -1;
73 }
74
75 return volume_init(v);
76 }
77
78 static int
79 switch2jffs(void)
80 {
81 struct volume *v = volume_find("rootfs_data");
82 struct stat s;
83 int ret;
84
85 if (!stat(SWITCH_JFFS2, &s)) {
86 fprintf(stderr, "jffs2 switch already running\n");
87 return -1;
88 }
89
90 if (!v) {
91 fprintf(stderr, "no rootfs_data was found\n");
92 return -1;
93 }
94
95 creat("/tmp/.switch_jffs2", 0600);
96 ret = mount(v->blk, "/rom/overlay", "jffs2", MS_NOATIME, NULL);
97 unlink("/tmp/.switch_jffs2");
98 if (ret) {
99 fprintf(stderr, "failed - mount -t jffs2 %s /rom/overlay: %s\n", v->blk, strerror(errno));
100 return -1;
101 }
102
103 if (mount("none", "/", NULL, MS_NOATIME | MS_REMOUNT, 0)) {
104 fprintf(stderr, "failed - mount -o remount,ro none: %s\n", strerror(errno));
105 return -1;
106 }
107
108 system("cp -a /tmp/root/* /rom/overlay");
109
110 if (pivot("/rom", "/mnt")) {
111 fprintf(stderr, "failed - pivot /rom /mnt: %s\n", strerror(errno));
112 return -1;
113 }
114
115 if (mount_move("/mnt", "/tmp/root", "")) {
116 fprintf(stderr, "failed - mount -o move /mnt /tmp/root %s\n", strerror(errno));
117 return -1;
118 }
119
120 return fopivot("/overlay", "/rom");
121 }
122
123 int
124 handle_whiteout(const char *dir)
125 {
126 struct stat s;
127 char link[256];
128 ssize_t sz;
129 struct dirent **namelist;
130 int n;
131
132 n = scandir(dir, &namelist, NULL, NULL);
133
134 if (n < 1)
135 return -1;
136
137 while (n--) {
138 char file[256];
139
140 snprintf(file, sizeof(file), "%s%s", dir, namelist[n]->d_name);
141 if (!lstat(file, &s) && S_ISLNK(s.st_mode)) {
142 sz = readlink(file, link, sizeof(link) - 1);
143 if (sz > 0) {
144 char *orig;
145
146 link[sz] = '\0';
147 orig = strstr(&file[1], "/");
148 if (orig && !strcmp(link, "(overlay-whiteout)"))
149 unlink(orig);
150 }
151 }
152 free(namelist[n]);
153 }
154 free(namelist);
155
156 return 0;
157 }
158
159 int
160 jffs2_switch(int argc, char **argv)
161 {
162 struct volume *v;
163 char *mp;
164 int ret = -1;
165
166 if (find_mount_overlay("overlayfs:/tmp/root"))
167 return -1;
168
169 if (find_filesystem("overlay")) {
170 fprintf(stderr, "overlayfs not found\n");
171 return ret;
172 }
173
174 v = volume_find("rootfs_data");
175 mp = find_mount_point(v->blk, NULL);
176 if (mp) {
177 fprintf(stderr, "rootfs_data:%s is already mounted as %s\n", v->blk, mp);
178 return -1;
179 }
180
181 switch (volume_identify(v)) {
182 case FS_NONE:
183 fprintf(stderr, "no jffs2 marker found\n");
184 /* fall through */
185
186 case FS_DEADCODE:
187 ret = switch2jffs();
188 if (!ret) {
189 fprintf(stderr, "doing fo cleanup\n");
190 umount2("/tmp/root", MNT_DETACH);
191 foreachdir("/overlay/", handle_whiteout);
192 }
193 break;
194
195 case FS_JFFS2:
196 ret = jffs2_mount();
197 if (ret)
198 break;
199 if (mount_move("/tmp", "", "/overlay") || fopivot("/overlay", "/rom")) {
200 fprintf(stderr, "switching to jffs2 failed\n");
201 ret = -1;
202 }
203 break;
204 }
205
206 return ret;
207 }
208
209 static int mount_overlay_fs(void)
210 {
211 struct volume *v;
212
213 if (mkdir("/tmp/overlay", 0755)) {
214 fprintf(stderr, "failed to mkdir /tmp/overlay: %s\n", strerror(errno));
215 return -1;
216 }
217
218 v = volume_find("rootfs_data");
219 if (!v) {
220 fprintf(stderr, "rootfs_data does not exist\n");
221 return -1;
222 }
223
224 if (mount(v->blk, "/tmp/overlay", "jffs2", MS_NOATIME, NULL)) {
225 fprintf(stderr, "failed to mount -t jffs2 %s /tmp/overlay: %s\n",
226 v->blk, strerror(errno));
227 return -1;
228 }
229
230 volume_init(v);
231
232 return -1;
233 }
234
235 int mount_overlay(void)
236 {
237 struct volume *v = volume_find("rootfs_data");;
238 char *mp;
239
240 if (!v)
241 return -1;
242
243 mp = find_mount_point(v->blk, NULL);
244 if (mp) {
245 fprintf(stderr, "rootfs_data:%s is already mounted as %s\n", v->blk, mp);
246 return -1;
247 }
248
249 mount_overlay_fs();
250
251 extroot_prefix = "/tmp/overlay";
252 if (!mount_extroot()) {
253 fprintf(stderr, "fs-state: switched to extroot\n");
254 return 0;
255 }
256
257 fprintf(stderr, "switching to jffs2\n");
258 if (mount_move("/tmp", "", "/overlay") || fopivot("/overlay", "/rom")) {
259 fprintf(stderr, "switching to jffs2 failed - fallback to ramoverlay\n");
260 return ramoverlay();
261 }
262
263 return -1;
264 }