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 if (!glob(globdir, GLOB_NOESCAPE | GLOB_MARK | GLOB_ONLYDIR, NULL, &gl))
92 for (j = 0; j < gl.gl_pathc; j++) {
93 char *dir = gl.gl_pathv[j];
94 int len = strlen(gl.gl_pathv[j]);
96 if (len > 1 && dir[len - 1] == '/')
99 if (!lstat(gl.gl_pathv[j], &s) && !S_ISLNK(s.st_mode))
100 foreachdir(gl.gl_pathv[j], cb);
106 overlay_delete(const char *dir, bool _keep_sysupgrade)
108 keep_sysupgrade = _keep_sysupgrade;
109 foreachdir(dir, handle_rmdir);
113 overlay_mount(struct volume *v, char *fs)
115 if (mkdir("/tmp/overlay", 0755)) {
116 ULOG_ERR("failed to mkdir /tmp/overlay: %m\n");
120 if (mount(v->blk, "/tmp/overlay", fs, MS_NOATIME, NULL)) {
121 ULOG_ERR("failed to mount -t %s %s /tmp/overlay: %m\n", fs, v->blk);
129 switch2jffs(struct volume *v)
134 if (!stat(SWITCH_JFFS2, &s)) {
135 ULOG_ERR("jffs2 switch already running\n");
139 creat("/tmp/.switch_jffs2", 0600);
140 ret = mount(v->blk, "/rom/overlay", "jffs2", MS_NOATIME, NULL);
141 unlink("/tmp/.switch_jffs2");
143 ULOG_ERR("failed - mount -t jffs2 %s /rom/overlay: %m\n", v->blk);
147 if (mount("none", "/", NULL, MS_NOATIME | MS_REMOUNT, 0)) {
148 ULOG_ERR("failed - mount -o remount,ro none: %m\n");
152 if (system("cp -a /tmp/root/* /rom/overlay")) {
153 ULOG_ERR("failed - cp -a /tmp/root/* /rom/overlay: %m\n");
157 if (pivot("/rom", "/mnt")) {
158 ULOG_ERR("failed - pivot /rom /mnt: %m\n");
162 if (mount_move("/mnt", "/tmp/root", "")) {
163 ULOG_ERR("failed - mount -o move /mnt /tmp/root %m\n");
167 return fopivot("/overlay", "/rom");
171 handle_whiteout(const char *dir)
176 struct dirent **namelist;
179 n = scandir(dir, &namelist, NULL, NULL);
187 snprintf(file, sizeof(file), "%s%s", dir, namelist[n]->d_name);
188 if (!lstat(file, &s) && S_ISLNK(s.st_mode)) {
189 sz = readlink(file, link, sizeof(link) - 1);
194 orig = strstr(&file[1], "/");
195 if (orig && !strcmp(link, "(overlay-whiteout)"))
206 static char *overlay_fs_name(int type)
222 jffs2_switch(struct volume *v)
227 if (find_overlay_mount("overlayfs:/tmp/root"))
230 if (find_filesystem("overlay")) {
231 ULOG_ERR("overlayfs not supported by kernel\n");
236 mp = find_mount_point(v->blk, 0);
238 ULOG_ERR("rootfs_data:%s is already mounted as %s\n", v->blk, mp);
242 type = volume_identify(v);
243 fs_name = overlay_fs_name(type);
247 ULOG_ERR("no jffs2 marker found\n");
254 ULOG_INFO("performing overlay whiteout\n");
255 umount2("/tmp/root", MNT_DETACH);
256 foreachdir("/overlay/", handle_whiteout);
258 /* try hard to be in sync */
259 ULOG_INFO("syncronizing overlay\n");
260 system("cp -a /tmp/root/upper/* / 2>/dev/null");
266 if (overlay_mount(v, fs_name))
268 if (mount_move("/tmp", "", "/overlay") || fopivot("/overlay", "/rom")) {
269 ULOG_ERR("switching to %s failed\n", fs_name);
276 fs_state_set("/overlay", FS_STATE_READY);
280 static int overlay_mount_fs(struct volume *v)
282 char *fstype = overlay_fs_name(volume_identify(v));
284 if (mkdir("/tmp/overlay", 0755)) {
285 ULOG_ERR("failed to mkdir /tmp/overlay: %m\n");
289 if (mount(v->blk, "/tmp/overlay", fstype, MS_NOATIME, NULL)) {
290 ULOG_ERR("failed to mount -t %s %s /tmp/overlay: %m\n",
298 enum fs_state fs_state_get(const char *dir)
305 path = alloca(strlen(dir) + 1 + sizeof("/.fs_state"));
306 sprintf(path, "%s/.fs_state", dir);
307 len = readlink(path, valstr, sizeof(valstr) - 1);
309 return FS_STATE_UNKNOWN;
314 if (val > __FS_STATE_LAST)
315 return FS_STATE_UNKNOWN;
321 int fs_state_set(const char *dir, enum fs_state state)
326 if (fs_state_get(dir) == state)
329 path = alloca(strlen(dir) + 1 + sizeof("/.fs_state"));
330 sprintf(path, "%s/.fs_state", dir);
332 snprintf(valstr, sizeof(valstr), "%d", state);
334 return symlink(valstr, path);
338 int mount_overlay(struct volume *v)
345 mp = find_mount_point(v->blk, 0);
347 ULOG_ERR("rootfs_data:%s is already mounted as %s\n", v->blk, mp);
353 extroot_prefix = "/tmp/overlay";
354 if (!mount_extroot()) {
355 ULOG_INFO("switched to extroot\n");
359 switch(fs_state_get("/tmp/overlay")) {
360 case FS_STATE_UNKNOWN:
361 fs_state_set("/tmp/overlay", FS_STATE_PENDING);
362 if (fs_state_get("/tmp/overlay") != FS_STATE_PENDING) {
363 ULOG_ERR("unable to set filesystem state\n");
366 case FS_STATE_PENDING:
367 ULOG_INFO("overlay filesystem has not been fully initialized yet\n");
368 overlay_delete("/tmp/overlay", true);
374 fs_name = overlay_fs_name(volume_identify(v));
375 ULOG_INFO("switching to %s overlay\n", fs_name);
376 if (mount_move("/tmp", "", "/overlay") || fopivot("/overlay", "/rom")) {
377 ULOG_ERR("switching to %s failed - fallback to ramoverlay\n", fs_name);