addextroot support to mount_root

Signed-off-by: John Crispin <blogic@openwrt.org>

diff --git a/mount_root.c b/mount_root.c
index dc053686f21a52d81f9e22c787f375db193e9030..de78539122aa334ecdc8285313307459c83faa87 100644 (file)
--- 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");