2 * Copyright (C) 2014 John Crispin <blogic@openwrt.org>
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
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.
15 #include <sys/types.h>
16 #include <sys/mount.h>
18 #include <asm/byteorder.h>
30 #include "libfstools.h"
33 #define SWITCH_JFFS2 "/tmp/.switch_jffs2"
35 static bool keep_sysupgrade;
38 handle_rmdir(const char *dir)
51 while ((dt = readdir(d)) != NULL) {
52 if (fstatat(fd, dt->d_name, &st, AT_SYMLINK_NOFOLLOW) || S_ISDIR(st.st_mode))
55 if (keep_sysupgrade && !strcmp(dt->d_name, "sysupgrade.tgz"))
58 unlinkat(fd, dt->d_name, 0);
68 foreachdir(const char *dir, int (*cb)(const char*))
70 static char *globdir = NULL;
71 static size_t globdirlen = 0;
72 struct stat s = { 0 };
73 size_t dirlen = strlen(dir);
77 if (dirlen + sizeof("/*") > globdirlen) {
78 /* Alloc extra 256 B to avoid too many reallocs */
79 size_t len = dirlen + sizeof("/*") + 256;
82 tmp = realloc(globdir, len);
89 sprintf(globdir, "%s/*", dir);
91 /* Include GLOB_MARK as callbacks expect a trailing slash */
92 if (!glob(globdir, GLOB_NOESCAPE | GLOB_MARK | GLOB_ONLYDIR, NULL, &gl))
93 for (j = 0; j < gl.gl_pathc; j++) {
94 char *dir = gl.gl_pathv[j];
95 int len = strlen(gl.gl_pathv[j]);
98 /* Quick way of skipping files */
99 if (dir[len - 1] != '/')
102 /* lstat needs path without a trailing slash */
105 err = lstat(gl.gl_pathv[j], &s);
109 if (!err && !S_ISLNK(s.st_mode))
110 foreachdir(gl.gl_pathv[j], cb);
115 static void foreach_mount(int (*cb)(const char *, const char *))
117 FILE *fp = fopen("/proc/mounts", "r");
118 static char line[256];
123 while (fgets(line, sizeof(line), fp)) {
124 char device[32], mount_point[32];
126 if (sscanf(line, "%31s %31s %*s %*s %*u %*u", device, mount_point) == 2)
127 cb(device, mount_point);
134 overlay_delete(const char *dir, bool _keep_sysupgrade)
136 keep_sysupgrade = _keep_sysupgrade;
137 foreachdir(dir, handle_rmdir);
141 overlay_mount(struct volume *v, char *fs)
143 if (mkdir("/tmp/overlay", 0755)) {
144 ULOG_ERR("failed to mkdir /tmp/overlay: %m\n");
148 if (mount(v->blk, "/tmp/overlay", fs, MS_NOATIME, NULL)) {
149 ULOG_ERR("failed to mount -t %s %s /tmp/overlay: %m\n", fs, v->blk);
157 * move_mount - move mount point to the new root
159 static int move_mount(const char *device, const char *mount_point)
161 static const char *prefix = "/tmp/root/";
163 if (strncmp(mount_point, prefix, strlen(prefix)))
166 return mount_move(prefix, "/", mount_point + strlen(prefix));
170 switch2jffs(struct volume *v)
175 if (!stat(SWITCH_JFFS2, &s)) {
176 ULOG_ERR("jffs2 switch already running\n");
180 creat("/tmp/.switch_jffs2", 0600);
181 ret = mount(v->blk, "/rom/overlay", "jffs2", MS_NOATIME, NULL);
182 unlink("/tmp/.switch_jffs2");
184 ULOG_ERR("failed - mount -t jffs2 %s /rom/overlay: %m\n", v->blk);
188 if (mount("none", "/", NULL, MS_NOATIME | MS_REMOUNT, 0)) {
189 ULOG_ERR("failed - mount -o remount,ro none: %m\n");
193 if (system("cp -a /tmp/root/* /rom/overlay")) {
194 ULOG_ERR("failed - cp -a /tmp/root/* /rom/overlay: %m\n");
198 if (pivot("/rom", "/mnt")) {
199 ULOG_ERR("failed - pivot /rom /mnt: %m\n");
203 if (mount_move("/mnt", "/tmp/root", "")) {
204 ULOG_ERR("failed - mount -o move /mnt /tmp/root %m\n");
208 ret = fopivot("/overlay", "/rom");
211 * Besides copying overlay data from "tmpfs" to "jffs2" we should also
212 * move mount points that user could create during JFFS2 formatting.
213 * This has to happen after fopivot call because:
214 * 1) It's trivial to find mount points to move then (/tmp/root/...).
215 * 2) We can't do that earlier using /rom/overlay/upper/ as overlay(fs)
216 * doesn't support mounts. Mounting to upper dir don't make overlay
217 * /propagate/ files to the target dir.
219 foreach_mount(move_mount);
225 handle_whiteout(const char *dir)
230 struct dirent **namelist;
233 n = scandir(dir, &namelist, NULL, NULL);
241 snprintf(file, sizeof(file), "%s%s", dir, namelist[n]->d_name);
242 if (!lstat(file, &s) && S_ISLNK(s.st_mode)) {
243 sz = readlink(file, link, sizeof(link) - 1);
248 orig = strstr(&file[1], "/");
249 if (orig && !strcmp(link, "(overlay-whiteout)"))
260 static char *overlay_fs_name(int type)
276 jffs2_switch(struct volume *v)
281 if (find_overlay_mount("overlayfs:/tmp/root"))
284 if (find_filesystem("overlay")) {
285 ULOG_ERR("overlayfs not supported by kernel\n");
290 mp = find_mount_point(v->blk, 0);
292 ULOG_ERR("rootfs_data:%s is already mounted as %s\n", v->blk, mp);
296 type = volume_identify(v);
297 fs_name = overlay_fs_name(type);
301 ULOG_ERR("no jffs2 marker found\n");
308 ULOG_INFO("performing overlay whiteout\n");
309 umount2("/tmp/root", MNT_DETACH);
310 foreachdir("/overlay/", handle_whiteout);
312 /* try hard to be in sync */
313 ULOG_INFO("syncronizing overlay\n");
314 if (system("cp -a /tmp/root/upper/* / 2>/dev/null"))
315 ULOG_ERR("failed to sync jffs2 overlay\n");
321 if (overlay_mount(v, fs_name))
323 if (mount_move("/tmp", "", "/overlay") || fopivot("/overlay", "/rom")) {
324 ULOG_ERR("switching to %s failed\n", fs_name);
331 fs_state_set("/overlay", FS_STATE_READY);
335 static int overlay_mount_fs(struct volume *v)
337 char *fstype = overlay_fs_name(volume_identify(v));
339 if (mkdir("/tmp/overlay", 0755)) {
340 ULOG_ERR("failed to mkdir /tmp/overlay: %m\n");
344 if (mount(v->blk, "/tmp/overlay", fstype, MS_NOATIME, NULL)) {
345 ULOG_ERR("failed to mount -t %s %s /tmp/overlay: %m\n",
353 enum fs_state fs_state_get(const char *dir)
360 path = alloca(strlen(dir) + 1 + sizeof("/.fs_state"));
361 sprintf(path, "%s/.fs_state", dir);
362 len = readlink(path, valstr, sizeof(valstr) - 1);
364 return FS_STATE_UNKNOWN;
369 if (val > __FS_STATE_LAST)
370 return FS_STATE_UNKNOWN;
376 int fs_state_set(const char *dir, enum fs_state state)
381 if (fs_state_get(dir) == state)
384 path = alloca(strlen(dir) + 1 + sizeof("/.fs_state"));
385 sprintf(path, "%s/.fs_state", dir);
387 snprintf(valstr, sizeof(valstr), "%d", state);
389 return symlink(valstr, path);
393 int mount_overlay(struct volume *v)
400 mp = find_mount_point(v->blk, 0);
402 ULOG_ERR("rootfs_data:%s is already mounted as %s\n", v->blk, mp);
408 extroot_prefix = "/tmp/overlay";
409 if (!mount_extroot()) {
410 ULOG_INFO("switched to extroot\n");
414 switch(fs_state_get("/tmp/overlay")) {
415 case FS_STATE_UNKNOWN:
416 fs_state_set("/tmp/overlay", FS_STATE_PENDING);
417 if (fs_state_get("/tmp/overlay") != FS_STATE_PENDING) {
418 ULOG_ERR("unable to set filesystem state\n");
421 case FS_STATE_PENDING:
422 ULOG_INFO("overlay filesystem has not been fully initialized yet\n");
423 overlay_delete("/tmp/overlay", true);
429 fs_name = overlay_fs_name(volume_identify(v));
430 ULOG_INFO("switching to %s overlay\n", fs_name);
431 if (mount_move("/tmp", "", "/overlay") || fopivot("/overlay", "/rom")) {
432 ULOG_ERR("switching to %s failed - fallback to ramoverlay\n", fs_name);