block: support finding root device by mount point

[project/fstools.git] / block.c

diff --git a/block.c b/block.c
index bba68c2..2726b1c 100644 (file)
--- a/block.c
+++ b/block.c
@@ -19,6 +19,7 @@
 #include <syslog.h>
 #include <libgen.h>
 #include <glob.h>
+#include <dirent.h>
 
 #include <sys/stat.h>
 #include <sys/types.h>
@@ -410,14 +411,16 @@ static int config_load(char *cfg)
                uci_set_confdir(ctx, path);
        }
 
-       if (uci_load(ctx, "fstab", &pkg))
-       {
-               char *err;
-               uci_get_errorstr(ctx, &err, "fstab");
-               ERROR("extroot: failed to load %s/etc/config/%s\n",
-                     cfg ? cfg : "", err);
-               free(err);
-               return -1;
+       if (uci_load(ctx, "fstab", &pkg)) {
+               uci_set_confdir(ctx, "/etc/config");
+               if (uci_load(ctx, "fstab", &pkg)) {
+                       char *err;
+                       uci_get_errorstr(ctx, &err, "fstab");
+                       ERROR("extroot: failed to load %s/etc/config/%s\n",
+                             cfg ? cfg : "", err);
+                       free(err);
+                       return -1;
+               }
        }
 
        vlist_update(&mounts);
@@ -481,6 +484,7 @@ static void cache_load(int mtd)
        if (mtd) {
                _cache_load("/dev/mtdblock*");
                _cache_load("/dev/ubiblock*");
+               _cache_load("/dev/ubi?*_?*");
        }
        _cache_load("/dev/mmcblk*");
        _cache_load("/dev/sd*");
@@ -597,6 +601,10 @@ static void check_filesystem(struct blkid_struct_probe *pr)
        struct stat statbuf;
        char *e2fsck = "/usr/sbin/e2fsck";
 
+       /* UBIFS does not need stuff like fsck */
+       if (!strncmp(pr->id->name, "ubifs", 5))
+               return;
+
        if (strncmp(pr->id->name, "ext", 3)) {
                ERROR("check_filesystem: %s is not supported\n", pr->id->name);
                return;
@@ -878,6 +886,35 @@ static int find_block_ubi_RO(libubi_t libubi, char *name, char *part, int plen)
 }
 #endif
 
+static int find_root_dev(char *buf, int len)
+{
+       DIR *d;
+       dev_t root;
+       struct stat s;
+       struct dirent *e;
+
+       if (stat("/", &s))
+               return -1;
+
+       if (!(d = opendir("/dev")))
+               return -1;
+
+       root = s.st_dev;
+
+       while ((e = readdir(d)) != NULL) {
+               snprintf(buf, len, "/dev/%s", e->d_name);
+
+               if (stat(buf, &s) || s.st_rdev != root)
+                       continue;
+
+               closedir(d);
+               return 0;
+       }
+
+       closedir(d);
+       return -1;
+}
+
 static int check_extroot(char *path)
 {
        struct blkid_struct_probe *pr = NULL;
@@ -895,8 +932,10 @@ static int check_extroot(char *path)
                        return -1;
        }
 #else
-       if (find_block_mtd("rootfs", fs, sizeof(fs)))
-               return -1;
+       if (find_block_mtd("rootfs", fs, sizeof(fs))) {
+               if (find_root_dev(fs, sizeof(fs)))
+                       return -1;
+       }
 #endif
 
        list_for_each_entry(pr, &devices, list) {
@@ -906,6 +945,10 @@ static int check_extroot(char *path)
                        char tag[64];
                        char uuid[64] = { 0 };
 
+                       snprintf(tag, sizeof(tag), "%s/etc", path);
+                       if (stat(tag, &s))
+                               mkdir_p(tag);
+
                        snprintf(tag, sizeof(tag), "%s/etc/.extroot-uuid", path);
                        if (stat(tag, &s)) {
                                fp = fopen(tag, "w+");
@@ -973,7 +1016,8 @@ static int mount_extroot(char *cfg)
                pr = find_block_info(m->uuid, m->label, m->device);
        }
        if (pr) {
-               if (strncmp(pr->id->name, "ext", 3)) {
+               if (strncmp(pr->id->name, "ext", 3) &&
+                   strncmp(pr->id->name, "ubifs", 5)) {
                        ERROR("extroot: %s is not supported, try ext4\n", pr->id->name);
                        return -1;
                }
@@ -1004,7 +1048,6 @@ static int mount_extroot(char *cfg)
 static int main_extroot(int argc, char **argv)
 {
        struct blkid_struct_probe *pr;
-       char fs[32] = { 0 };
        char blkdev_path[32] = { 0 };
        int err = -1;
 #ifdef UBIFS_EXTROOT
@@ -1023,32 +1066,6 @@ static int main_extroot(int argc, char **argv)
        cache_load(1);
 
        /*
-        * Make sure there is "rootfs" MTD partition or UBI volume.
-        * TODO: What for?
-        */
-       find_block_mtd("rootfs", fs, sizeof(fs));
-       if (!fs[0]) {
-#ifdef UBIFS_EXTROOT
-               libubi = libubi_open();
-               find_block_ubi_RO(libubi, "rootfs", fs, sizeof(fs));
-               libubi_close(libubi);
-               if (!fs[0]) {
-                       ERROR("extroot: unable to locate rootfs mtdblock / ubiblock\n");
-                       return -2;
-               }
-#else
-               ERROR("extroot: unable to locate rootfs mtdblock\n");
-               return -2;
-#endif
-       }
-
-       pr = find_block_info(NULL, NULL, fs);
-       if (!pr) {
-               ERROR("extroot: unable to retrieve rootfs information\n");
-               return -3;
-       }
-
-       /*
         * Look for "rootfs_data". We will want to mount it and check for
         * extroot configuration.
         */