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);
116 overlay_delete(const char *dir, bool _keep_sysupgrade)
118 keep_sysupgrade = _keep_sysupgrade;
119 foreachdir(dir, handle_rmdir);
123 overlay_mount(struct volume *v, char *fs)
125 if (mkdir("/tmp/overlay", 0755)) {
126 ULOG_ERR("failed to mkdir /tmp/overlay: %m\n");
130 if (mount(v->blk, "/tmp/overlay", fs, MS_NOATIME, NULL)) {
131 ULOG_ERR("failed to mount -t %s %s /tmp/overlay: %m\n", fs, v->blk);
139 switch2jffs(struct volume *v)
144 if (!stat(SWITCH_JFFS2, &s)) {
145 ULOG_ERR("jffs2 switch already running\n");
149 creat("/tmp/.switch_jffs2", 0600);
150 ret = mount(v->blk, "/rom/overlay", "jffs2", MS_NOATIME, NULL);
151 unlink("/tmp/.switch_jffs2");
153 ULOG_ERR("failed - mount -t jffs2 %s /rom/overlay: %m\n", v->blk);
157 if (mount("none", "/", NULL, MS_NOATIME | MS_REMOUNT, 0)) {
158 ULOG_ERR("failed - mount -o remount,ro none: %m\n");
162 if (system("cp -a /tmp/root/* /rom/overlay")) {
163 ULOG_ERR("failed - cp -a /tmp/root/* /rom/overlay: %m\n");
167 if (pivot("/rom", "/mnt")) {
168 ULOG_ERR("failed - pivot /rom /mnt: %m\n");
172 if (mount_move("/mnt", "/tmp/root", "")) {
173 ULOG_ERR("failed - mount -o move /mnt /tmp/root %m\n");
177 return fopivot("/overlay", "/rom");
181 handle_whiteout(const char *dir)
186 struct dirent **namelist;
189 n = scandir(dir, &namelist, NULL, NULL);
197 snprintf(file, sizeof(file), "%s%s", dir, namelist[n]->d_name);
198 if (!lstat(file, &s) && S_ISLNK(s.st_mode)) {
199 sz = readlink(file, link, sizeof(link) - 1);
204 orig = strstr(&file[1], "/");
205 if (orig && !strcmp(link, "(overlay-whiteout)"))
216 static char *overlay_fs_name(int type)
232 jffs2_switch(struct volume *v)
237 if (find_overlay_mount("overlayfs:/tmp/root"))
240 if (find_filesystem("overlay")) {
241 ULOG_ERR("overlayfs not supported by kernel\n");
246 mp = find_mount_point(v->blk, 0);
248 ULOG_ERR("rootfs_data:%s is already mounted as %s\n", v->blk, mp);
252 type = volume_identify(v);
253 fs_name = overlay_fs_name(type);
257 ULOG_ERR("no jffs2 marker found\n");
264 ULOG_INFO("performing overlay whiteout\n");
265 umount2("/tmp/root", MNT_DETACH);
266 foreachdir("/overlay/", handle_whiteout);
268 /* try hard to be in sync */
269 ULOG_INFO("syncronizing overlay\n");
270 if (system("cp -a /tmp/root/upper/* / 2>/dev/null"))
271 ULOG_ERR("failed to sync jffs2 overlay\n");
277 if (overlay_mount(v, fs_name))
279 if (mount_move("/tmp", "", "/overlay") || fopivot("/overlay", "/rom")) {
280 ULOG_ERR("switching to %s failed\n", fs_name);
287 fs_state_set("/overlay", FS_STATE_READY);
291 static int overlay_mount_fs(struct volume *v)
293 char *fstype = overlay_fs_name(volume_identify(v));
295 if (mkdir("/tmp/overlay", 0755)) {
296 ULOG_ERR("failed to mkdir /tmp/overlay: %m\n");
300 if (mount(v->blk, "/tmp/overlay", fstype, MS_NOATIME, NULL)) {
301 ULOG_ERR("failed to mount -t %s %s /tmp/overlay: %m\n",
309 enum fs_state fs_state_get(const char *dir)
316 path = alloca(strlen(dir) + 1 + sizeof("/.fs_state"));
317 sprintf(path, "%s/.fs_state", dir);
318 len = readlink(path, valstr, sizeof(valstr) - 1);
320 return FS_STATE_UNKNOWN;
325 if (val > __FS_STATE_LAST)
326 return FS_STATE_UNKNOWN;
332 int fs_state_set(const char *dir, enum fs_state state)
337 if (fs_state_get(dir) == state)
340 path = alloca(strlen(dir) + 1 + sizeof("/.fs_state"));
341 sprintf(path, "%s/.fs_state", dir);
343 snprintf(valstr, sizeof(valstr), "%d", state);
345 return symlink(valstr, path);
349 int mount_overlay(struct volume *v)
356 mp = find_mount_point(v->blk, 0);
358 ULOG_ERR("rootfs_data:%s is already mounted as %s\n", v->blk, mp);
364 extroot_prefix = "/tmp/overlay";
365 if (!mount_extroot()) {
366 ULOG_INFO("switched to extroot\n");
370 switch(fs_state_get("/tmp/overlay")) {
371 case FS_STATE_UNKNOWN:
372 fs_state_set("/tmp/overlay", FS_STATE_PENDING);
373 if (fs_state_get("/tmp/overlay") != FS_STATE_PENDING) {
374 ULOG_ERR("unable to set filesystem state\n");
377 case FS_STATE_PENDING:
378 ULOG_INFO("overlay filesystem has not been fully initialized yet\n");
379 overlay_delete("/tmp/overlay", true);
385 fs_name = overlay_fs_name(volume_identify(v));
386 ULOG_INFO("switching to %s overlay\n", fs_name);
387 if (mount_move("/tmp", "", "/overlay") || fopivot("/overlay", "/rom")) {
388 ULOG_ERR("switching to %s failed - fallback to ramoverlay\n", fs_name);