From 768f6a1a1c06b2a04a8c2453f419eb439f6a48a0 Mon Sep 17 00:00:00 2001
From: John Crispin <blogic@openwrt.org>
Date: Wed, 19 Jun 2013 21:16:27 +0200
Subject: [PATCH] addextroot support to mount_root
Signed-off-by: John Crispin <blogic@openwrt.org>
---
mount_root.c | 189 +++++++++++++++------------------------------------
1 file changed, 56 insertions(+), 133 deletions(-)
diff --git a/mount_root.c b/mount_root.c
index dc05368..de78539 100644
--- a/mount_root.c
+++ b/mount_root.c
@@ -27,6 +27,7 @@
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/mount.h>
+#include <sys/wait.h>
#include <asm/byteorder.h>
@@ -78,6 +79,24 @@ static void foreachdir(const char *dir, int (*cb)(const char*))
cb(dir);
}
+static int find_overlay_mount(char *overlay)
+{
+ FILE *fp = fopen("/proc/mounts", "r");
+ static char line[256];
+ int ret = -1;
+
+ if(!fp)
+ return ret;
+
+ while (ret && fgets(line, sizeof(line), fp))
+ if (!strncmp(line, overlay, strlen(overlay)))
+ ret = 0;
+
+ fclose(fp);
+
+ return ret;
+}
+
static char* find_mount_point(char *block, char *fs)
{
FILE *fp = fopen("/proc/mounts", "r");
@@ -196,36 +215,7 @@ err_out:
return ret;
}
-static int mtd_erase(const char *mtd)
-{
- int fd = open(mtd, O_RDWR | O_SYNC);
- struct mtd_info_user i;
- struct erase_info_user e;
- int ret;
-
- if (!fd) {
- ERROR("failed to open %s: %s\n", mtd, strerror(errno));
- return -1;
- }
-
- ret = ioctl(fd, MEMGETINFO, &i);
- if (ret) {
- ERROR("ioctl(%s, MEMGETINFO) failed: %s\n", mtd, strerror(errno));
- return -1;
- }
-
- e.length = i.erasesize;
- for (e.start = 0; e.start < i.size; e.start += i.erasesize) {
- ioctl(fd, MEMUNLOCK, &e);
- if(ioctl(fd, MEMERASE, &e))
- ERROR("Failed to erase block on %s at 0x%x\n", mtd, e.start);
- }
-
- close(fd);
- return 0;
-}
-
-static int do_mount_jffs2(void)
+static int mtd_mount_jffs2(void)
{
char rootfs_data[32];
@@ -363,6 +353,7 @@ static int pivot(char *new, char *old)
mount_move(old, "", "/tmp");
mount_move(old, "", "/sys");
mount_move(old, "", "/overlay");
+ mount_move(old, "", "/extroot");
return 0;
}
@@ -477,6 +468,9 @@ static int main_switch2jffs(int argc, char **argv)
char *mp;
int ret = -1;
+ if (find_overlay_mount("overlayfs:/tmp/root"))
+ return -1;
+
if (check_fs_exists("overlay")) {
ERROR("overlayfs not found\n");
return ret;
@@ -509,7 +503,7 @@ static int main_switch2jffs(int argc, char **argv)
break;
case FS_JFFS2:
- ret = do_mount_jffs2();
+ ret = mtd_mount_jffs2();
if (ret)
break;
if (mount_move("/tmp", "", "/overlay") || fopivot("/overlay", "/rom")) {
@@ -522,109 +516,36 @@ static int main_switch2jffs(int argc, char **argv)
return ret;
}
-static int ask_user(int argc, char **argv)
-{
- if ((argc < 2) || strcmp(argv[1], "-y")) {
- LOG("This will erase all settings and remove any installed packages. Are you sure? [N/y]\n");
- if (getchar() != 'y')
- return -1;
- }
- return 0;
-
-}
-
-static int handle_rmdir(const char *dir)
+static int extroot(void)
{
struct stat s;
- struct dirent **namelist;
- int n;
+ pid_t pid;
- n = scandir(dir, &namelist, NULL, NULL);
-
- if (n < 1)
+ if (stat("/sbin/block", &s))
return -1;
- while (n--) {
- char file[256];
-
- snprintf(file, sizeof(file), "%s%s", dir, namelist[n]->d_name);
- if (!lstat(file, &s) && !S_ISDIR(s.st_mode)) {
- DEBUG(1, "unlinking %s\n", file);
- unlink(file);
+ pid = fork();
+ if (!pid) {
+ mkdir("/tmp/extroot", 0755);
+ execl("/sbin/block", "/sbin/block", "extroot", NULL);
+ exit(-1);
+ } else if (pid > 0) {
+ int status;
+
+ waitpid(pid, &status, 0);
+ if (!WEXITSTATUS(status)) {
+ if (mount_move("/tmp", "", "/overlay")) {
+ ERROR("moving extroot failed - continue normal boot\n");
+ umount("/tmp/overlay");
+ } else if (fopivot("/overlay", "/rom")) {
+ ERROR("switching to extroot failed - continue normal boot\n");
+ umount("overlay");
+ } else {
+ return 0;
+ }
}
- free(namelist[n]);
}
- free(namelist);
-
- DEBUG(1, "rmdir %s\n", dir);
- rmdir(dir);
-
- return 0;
-}
-
-static int main_jffs2reset(int argc, char **argv)
-{
- char mtd[32];
- char *mp;
-
- if (ask_user(argc, argv))
- return -1;
-
- if (check_fs_exists("overlay")) {
- ERROR("overlayfs not found\n");
- return -1;
- }
-
- if (find_mtd_block("rootfs_data", mtd, sizeof(mtd))) {
- ERROR("no rootfs_data was found\n");
- return -1;
- }
-
- mp = find_mount_point(mtd, "jffs2");
- if (mp) {
- LOG("%s is mounted as %s, only ereasing files\n", mtd, mp);
- foreachdir(mp, handle_rmdir);
- mount(mp, "/", NULL, MS_REMOUNT, 0);
- } else {
- LOG("%s is not mounted, erasing it\n", mtd);
- find_mtd_char("rootfs_data", mtd, sizeof(mtd));
- mtd_erase(mtd);
- }
-
- return 0;
-}
-
-static int main_jffs2mark(int argc, char **argv)
-{
- FILE *fp;
- __u32 deadc0de = __cpu_to_be32(0xdeadc0de);
- char mtd[32];
- size_t sz;
-
- if (ask_user(argc, argv))
- return -1;
-
- if (find_mtd_block("rootfs_data", mtd, sizeof(mtd))) {
- ERROR("no rootfs_data was found\n");
- return -1;
- }
-
- fp = fopen(mtd, "w");
- LOG("%s - marking with deadc0de\n", mtd);
- if (!fp) {
- ERROR("opening %s failed\n", mtd);
- return -1;
- }
-
- sz = fwrite(&deadc0de, sizeof(deadc0de), 1, fp);
- fclose(fp);
-
- if (sz != 1) {
- ERROR("writing %s failed: %s\n", mtd, strerror(errno));
- return -1;
- }
-
- return 0;
+ return -1;
}
int main(int argc, char **argv)
@@ -637,11 +558,8 @@ int main(int argc, char **argv)
if (!strcmp(basename(*argv), "switch2jffs"))
return main_switch2jffs(argc, argv);
- if (!strcmp(basename(*argv), "jffs2mark"))
- return main_jffs2mark(argc, argv);
-
- if (!strcmp(basename(*argv), "jffs2reset"))
- return main_jffs2reset(argc, argv);
+ if (!getenv("PREINIT"))
+ return -1;
if (find_mtd_char("rootfs_data", mtd, sizeof(mtd))) {
if (!find_mtd_char("rootfs", mtd, sizeof(mtd)))
@@ -649,6 +567,11 @@ int main(int argc, char **argv)
LOG("mounting /dev/root\n");
mount("/dev/root", "/", NULL, MS_NOATIME | MS_REMOUNT, 0);
} else {
+ if (!extroot()) {
+ fprintf(stderr, "mount_root: switched to extroot\n");
+ return 0;
+ }
+
switch (jffs2_ready(mtd)) {
case FS_NONE:
case FS_DEADCODE:
@@ -662,7 +585,7 @@ int main(int argc, char **argv)
return -1;
}
- do_mount_jffs2();
+ mtd_mount_jffs2();
DEBUG(1, "switching to jffs2\n");
if (mount_move("/tmp", "", "/overlay") || fopivot("/overlay", "/rom")) {
ERROR("switching to jffs2 failed - fallback to ramoverlay\n");
--
2.25.1