support UBI blocks (volumes)

[project/fstools.git] / block.c

diff --git a/block.c b/block.c
index 6d187d1..68cfd5a 100644 (file)
--- a/block.c
+++ b/block.c
@@ -481,6 +481,7 @@ 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*");
@@ -935,6 +936,9 @@ static int check_extroot(char *path)
        return -1;
 }
 
+/*
+ * Read info about extroot from UCI (using prefix) and mount it.
+ */
 static int mount_extroot(char *cfg)
 {
        char overlay[] = "/tmp/extroot/overlay";
@@ -944,9 +948,11 @@ static int mount_extroot(char *cfg)
        struct mount *m;
        int err = -1;
 
+       /* Load @cfg/etc/config/fstab */
        if (config_load(cfg))
                return -2;
 
+       /* See if there is extroot-specific mount config */
        m = find_block(NULL, NULL, NULL, "/");
        if (!m)
                m = find_block(NULL, NULL, NULL, "/overlay");
@@ -957,6 +963,7 @@ static int mount_extroot(char *cfg)
                return -1;
        }
 
+       /* Find block device pointed by the mount config */
        pr = find_block_info(m->uuid, m->label, m->device);
 
        if (!pr && delay_root){
@@ -999,7 +1006,7 @@ static int main_extroot(int argc, char **argv)
 {
        struct blkid_struct_probe *pr;
        char fs[32] = { 0 };
-       char fs_data[32] = { 0 };
+       char blkdev_path[32] = { 0 };
        int err = -1;
 #ifdef UBIFS_EXTROOT
        libubi_t libubi;
@@ -1016,6 +1023,10 @@ static int main_extroot(int argc, char **argv)
        mkblkdev();
        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
@@ -1038,14 +1049,24 @@ static int main_extroot(int argc, char **argv)
                return -3;
        }
 
-       find_block_mtd("rootfs_data", fs_data, sizeof(fs_data));
-       if (fs_data[0]) {
-               pr = find_block_info(NULL, NULL, fs_data);
+       /*
+        * Look for "rootfs_data". We will want to mount it and check for
+        * extroot configuration.
+        */
+
+       /* Start with looking for MTD partition */
+       find_block_mtd("rootfs_data", blkdev_path, sizeof(blkdev_path));
+       if (blkdev_path[0]) {
+               pr = find_block_info(NULL, NULL, blkdev_path);
                if (pr && !strcmp(pr->id->name, "jffs2")) {
                        char cfg[] = "/tmp/jffs_cfg";
 
+                       /*
+                        * Mount MTD part and try extroot (using
+                        * /etc/config/fstab from that partition)
+                        */
                        mkdir_p(cfg);
-                       if (!mount(fs_data, cfg, "jffs2", MS_NOATIME, NULL)) {
+                       if (!mount(blkdev_path, cfg, "jffs2", MS_NOATIME, NULL)) {
                                err = mount_extroot(cfg);
                                umount2(cfg, MNT_DETACH);
                        }
@@ -1057,15 +1078,17 @@ static int main_extroot(int argc, char **argv)
        }
 
 #ifdef UBIFS_EXTROOT
-       memset(fs_data, 0, sizeof(fs_data));
+       /* ... but it also could be an UBI volume */
+       memset(blkdev_path, 0, sizeof(blkdev_path));
        libubi = libubi_open();
-       find_block_ubi(libubi, "rootfs_data", fs_data, sizeof(fs_data));
+       find_block_ubi(libubi, "rootfs_data", blkdev_path, sizeof(blkdev_path));
        libubi_close(libubi);
-       if (fs_data[0]) {
+       if (blkdev_path[0]) {
                char cfg[] = "/tmp/ubifs_cfg";
 
+               /* Mount volume and try extroot (using fstab from that vol) */
                mkdir_p(cfg);
-               if (!mount(fs_data, cfg, "ubifs", MS_NOATIME, NULL)) {
+               if (!mount(blkdev_path, cfg, "ubifs", MS_NOATIME, NULL)) {
                        err = mount_extroot(cfg);
                        umount2(cfg, MNT_DETACH);
                }