block: try to find the root device on both / and /rom
[project/fstools.git] / block.c
diff --git a/block.c b/block.c
index 50d877fbeb08e1d2b445549224f0565eecd56791..7b2ea8fd31141d87baed7d0ca26372e1ff42daf3 100644 (file)
--- a/block.c
+++ b/block.c
 #include <sys/wait.h>
 #include <sys/sysmacros.h>
 
-#include <linux/fs.h>
-
 #include <uci.h>
 #include <uci_blob.h>
 
-#include <libubox/ulog.h>
+#include <libubox/avl-cmp.h>
+#include <libubox/blobmsg_json.h>
 #include <libubox/list.h>
+#include <libubox/ulog.h>
+#include <libubox/utils.h>
 #include <libubox/vlist.h>
-#include <libubox/blobmsg_json.h>
-#include <libubox/avl-cmp.h>
 #include <libubus.h>
 
 #include "probe.h"
@@ -82,20 +81,9 @@ struct mount {
        unsigned int prio;
 };
 
-struct device {
-       struct vlist_node node;
-
-       struct probe_info *pr;
-       struct mount *m;
-};
-
-static void vlist_nop_update(struct vlist_tree *tree, struct vlist_node *node_new,
-                         struct vlist_node *node_old);
-static int devices_cmp(const void *k1, const void *k2, void *ptr);
-
+static struct vlist_tree mounts;
 static struct blob_buf b;
-static VLIST_TREE(mounts, avl_strcmp, vlist_nop_update, false, false);
-static VLIST_TREE(devices, devices_cmp, vlist_nop_update, false, false);
+static LIST_HEAD(devices);
 static int anon_mount, anon_swap, auto_mount, auto_swap, check_fs;
 static unsigned int delay_root;
 
@@ -420,10 +408,9 @@ static struct mount* find_block(const char *uuid, const char *label, const char
        return NULL;
 }
 
-static void vlist_nop_update(struct vlist_tree *tree, struct vlist_node *node_new,
+static void mounts_update(struct vlist_tree *tree, struct vlist_node *node_new,
                          struct vlist_node *node_old)
 {
-       // NOTE: free on delete skipped
 }
 
 static struct uci_package * config_try_load(struct uci_context *ctx, char *path)
@@ -454,6 +441,8 @@ static int config_load(char *cfg)
        struct uci_element *e;
        char path[64];
 
+       vlist_init(&mounts, avl_strcmp, mounts_update);
+
        if (cfg) {
                snprintf(path, sizeof(path), "%s/upper/etc/config/fstab", cfg);
                pkg = config_try_load(ctx, path);
@@ -490,21 +479,82 @@ static int config_load(char *cfg)
        return 0;
 }
 
+static bool mtdblock_is_nand(char *mtdnum)
+{
+       char tmppath[64];
+       char buf[16];
+       FILE *fp;
+
+       snprintf(tmppath, sizeof(tmppath) - 1, "/sys/class/mtd/mtd%s/type", mtdnum);
+       fp = fopen(tmppath, "r");
+       if (!fp)
+               return false;
+
+       if (!fgets(buf, sizeof(buf), fp)) {
+               fclose(fp);
+               return false;
+       }
+       fclose(fp);
+       buf[sizeof(buf) - 1] = '\0'; /* make sure buf is 0-terminated */
+       buf[strlen(buf) - 1] = '\0'; /* strip final char (newline) */
+
+       if (strcmp(buf, "nand"))
+               return false;
+
+       /*
+        * --- CUT HERE ---
+        * Keep probing rootfs and rootfs_data in the meantime to not break
+        * devices using JFFS2 on NAND but only trigger the kernel warnings.
+        * Remove this once all devices using JFFS2 and squashfs directly on
+        * NAND have been converted to UBI.
+        */
+       snprintf(tmppath, sizeof(tmppath) - 1, "/sys/class/mtd/mtd%s/name", mtdnum);
+       fp = fopen(tmppath, "r");
+       if (!fp)
+               return false;
+
+       if (!fgets(buf, sizeof(buf), fp)) {
+               fclose(fp);
+               return false;
+       }
+       fclose(fp);
+       buf[sizeof(buf) - 1] = '\0'; /* make sure buf is 0-terminated */
+       buf[strlen(buf) - 1] = '\0'; /* strip final char (newline) */
+
+       /* only return true if name differs from 'rootfs' and 'rootfs_data' */
+       if (strcmp(buf, "rootfs") && strcmp(buf, "rootfs_data"))
+               return true;
+
+       /* --- CUT HERE --- */
+       return false;
+}
+
 static struct probe_info* _probe_path(char *path)
 {
-       struct device *dev;
+       struct probe_info *pr, *epr;
        char tmppath[64];
 
-       /* skip ubi device if ubiblock device is present */
+       if (!strncmp(path, "/dev/mtdblock", 13) && mtdblock_is_nand(path + 13))
+               return NULL;
+
+       pr = probe_path(path);
+       if (!pr)
+               return NULL;
+
        if (path[5] == 'u' && path[6] == 'b' && path[7] == 'i' &&
            path[8] >= '0' && path[8] <= '9' ) {
+               /* skip ubi device if not UBIFS (as it requires ubiblock) */
+               if (strcmp("ubifs", pr->type))
+                       return NULL;
+
+               /* skip ubi device if ubiblock device is present */
                snprintf(tmppath, sizeof(tmppath), "/dev/ubiblock%s", path + 8);
-               vlist_for_each_element(&devices, dev, node)
-                       if (!strcasecmp(dev->pr->dev, tmppath))
+               list_for_each_entry(epr, &devices, list)
+                       if (!strcmp(epr->dev, tmppath))
                                return NULL;
        }
 
-       return probe_path(path);
+       return pr;
 }
 
 static int _cache_load(const char *path)
@@ -512,20 +562,14 @@ static int _cache_load(const char *path)
        int gl_flags = GLOB_NOESCAPE | GLOB_MARK;
        int j;
        glob_t gl;
-       struct device *dev;
 
        if (glob(path, gl_flags, NULL, &gl) < 0)
                return -1;
 
        for (j = 0; j < gl.gl_pathc; j++) {
                struct probe_info *pr = _probe_path(gl.gl_pathv[j]);
-               if (pr) {
-                       dev = malloc(sizeof(struct device));
-                       dev->pr = pr;
-                       dev->m = find_block(pr->uuid, pr->label,
-                                       basename(pr->dev), NULL);
-                       vlist_add(&devices, &dev->node, dev);
-               }
+               if (pr)
+                       list_add_tail(&pr->list, &devices);
        }
 
        globfree(&gl);
@@ -533,30 +577,8 @@ static int _cache_load(const char *path)
        return 0;
 }
 
-static int devices_cmp(const void *k1, const void *k2, void *ptr)
-{
-       struct device *dev1 = (struct device *)k1;
-       struct device *dev2 = (struct device *)k2;
-
-       if (dev1->m) {
-               if (!dev2->m)
-                       return -1;
-               if (dev1->m->type == TYPE_MOUNT && dev2->m->type == TYPE_MOUNT &&
-                               dev1->m->target && dev2->m->target) {
-                       int len1 = strlen(dev1->m->target);
-                       int len2 = strlen(dev2->m->target);
-                       if (len1 != len2)
-                               return len1 - len2;
-               }
-       } else if (dev2->m) {
-               return 1;
-       }
-       return strcmp(dev1->pr->dev, dev2->pr->dev);
-}
-
 static void cache_load(int mtd)
 {
-       vlist_update(&devices);
        if (mtd) {
                _cache_load("/dev/mtdblock*");
                _cache_load("/dev/ubiblock*");
@@ -570,29 +592,28 @@ static void cache_load(int mtd)
        _cache_load("/dev/nvme*");
        _cache_load("/dev/vd*");
        _cache_load("/dev/xvd*");
-       _cache_load("/dev/mapper/*");
-       vlist_flush(&devices);
+       _cache_load("/dev/dm-*");
 }
 
 
-static struct device* find_block_device(char *uuid, char *label, char *path)
+static struct probe_info* find_block_info(char *uuid, char *label, char *path)
 {
-       struct device *dev;
+       struct probe_info *pr = NULL;
 
        if (uuid)
-               vlist_for_each_element(&devices, dev, node)
-                       if (dev->pr->uuid && !strcasecmp(dev->pr->uuid, uuid))
-                               return dev;
+               list_for_each_entry(pr, &devices, list)
+                       if (pr->uuid && !strcasecmp(pr->uuid, uuid))
+                               return pr;
 
        if (label)
-               vlist_for_each_element(&devices, dev, node)
-                       if (dev->pr->label && !strcmp(dev->pr->label, label))
-                               return dev;
+               list_for_each_entry(pr, &devices, list)
+                       if (pr->label && !strcmp(pr->label, label))
+                               return pr;
 
        if (path)
-               vlist_for_each_element(&devices, dev, node)
-                       if (dev->pr->dev && !strcmp(basename(dev->pr->dev), basename(path)))
-                               return dev;
+               list_for_each_entry(pr, &devices, list)
+                       if (pr->dev && !strcmp(basename(pr->dev), basename(path)))
+                               return pr;
 
        return NULL;
 }
@@ -736,18 +757,6 @@ static int print_block_info(struct probe_info *pr)
        return 0;
 }
 
-static void mkdir_p(char *dir)
-{
-       char *l = strrchr(dir, '/');
-
-       if (l) {
-               *l = '\0';
-               mkdir_p(dir);
-               *l = '/';
-               mkdir(dir, 0755);
-       }
-}
-
 static void check_filesystem(struct probe_info *pr)
 {
        pid_t pid;
@@ -925,44 +934,34 @@ static int exec_mount(const char *source, const char *target,
        return err;
 }
 
-static int hotplug_call_mount(const char *action, const char *device)
-{
-       pid_t pid;
-       int err = 0;
-
-       pid = fork();
-       if (!pid) {
-               char * const argv[] = { "hotplug-call", "mount", NULL };
-
-               setenv("ACTION", action, 1);
-               setenv("DEVICE", device, 1);
-
-               execv("/sbin/hotplug-call", argv);
-               exit(-1);
-       } else if (pid > 0) {
-               int status;
-
-               pid = waitpid(pid, &status, 0);
-               if (pid <= 0 || !WIFEXITED(status) || WEXITSTATUS(status)) {
-                       err = -ENOEXEC;
-                       ULOG_ERR("hotplug-call call failed\n");
-               }
-       } else {
-               err = -errno;
-       }
-
-       return err;
-}
+static const char * const ntfs_fs[] = { "ntfs3", "ntfs-3g", "antfs", "ntfs" };
 
 static int handle_mount(const char *source, const char *target,
                         const char *fstype, struct mount *m)
 {
-       int i, err;
        size_t mount_opts_len;
        char *mount_opts = NULL, *ptr;
+       const char * const *filesystems;
+       int err = -EINVAL;
+       size_t count;
+       int i;
+
+       if (!strcmp(fstype, "ntfs")) {
+               filesystems = ntfs_fs;
+               count = ARRAY_SIZE(ntfs_fs);
+       } else {
+               filesystems = &fstype;
+               count = 1;
+       }
 
-       err = mount(source, target, fstype, m ? m->flags : 0,
-                   (m && m->options) ? m->options : "");
+       for (i = 0; i < count; i++) {
+               const char *fs = filesystems[i];
+
+               err = mount(source, target, fs, m ? m->flags : 0,
+                           (m && m->options) ? m->options : "");
+               if (!err || errno != ENODEV)
+                       break;
+       }
 
        /* Requested file system type is not available in kernel,
           attempt to call mount helper. */
@@ -999,13 +998,22 @@ static int handle_mount(const char *source, const char *target,
                }
 
                /* ... and now finally invoke the external mount program */
-               err = exec_mount(source, target, fstype, mount_opts);
+               for (i = 0; i < count; i++) {
+                       const char *fs = filesystems[i];
+
+                       err = exec_mount(source, target, fs, mount_opts);
+                       if (!err)
+                               break;
+               }
        }
 
+       free(mount_opts);
+
        return err;
 }
 
-static int blockd_notify(char *device, struct mount *m, struct probe_info *pr)
+static int blockd_notify(const char *method, char *device, struct mount *m,
+                        struct probe_info *pr)
 {
        struct ubus_context *ctx = ubus_connect(NULL);
        uint32_t id;
@@ -1058,7 +1066,7 @@ static int blockd_notify(char *device, struct mount *m, struct probe_info *pr)
                        blobmsg_add_u32(&buf, "remove", 1);
                }
 
-               err = ubus_invoke(ctx, id, "hotplug", buf.head, NULL, NULL, 3000);
+               err = ubus_invoke(ctx, id, method, buf.head, NULL, NULL, 3000);
        } else {
                err = -ENOENT;
        }
@@ -1068,20 +1076,19 @@ static int blockd_notify(char *device, struct mount *m, struct probe_info *pr)
        return err;
 }
 
-static int mount_device(struct device *dev, int type)
+static int mount_device(struct probe_info *pr, int type)
 {
        struct mount *m;
-       struct probe_info *pr;
-       char _target[32];
+       struct stat st;
+       char *_target = NULL;
        char *target;
        char *device;
        char *mp;
        int err;
 
-       if (!dev)
+       if (!pr)
                return -1;
 
-       pr = dev->pr;
        device = basename(pr->dev);
 
        if (!strcmp(pr->type, "swap")) {
@@ -1094,13 +1101,13 @@ static int mount_device(struct device *dev, int type)
                return 0;
        }
 
-       m = dev->m;
+       m = find_block(pr->uuid, pr->label, device, NULL);
        if (m && m->extroot)
                return -1;
 
        mp = find_mount_point(pr->dev);
        if (mp) {
-               if (m && m->type == TYPE_MOUNT && strcmp(m->target, mp)) {
+               if (m && m->type == TYPE_MOUNT && m->target && strcmp(m->target, mp)) {
                        ULOG_ERR("%s is already mounted on %s\n", pr->dev, mp);
                        err = -1;
                } else
@@ -1110,7 +1117,7 @@ static int mount_device(struct device *dev, int type)
        }
 
        if (type == TYPE_HOTPLUG)
-               blockd_notify(device, m, pr);
+               blockd_notify("hotplug", device, m, pr);
 
        /* Check if device should be mounted & set the target directory */
        if (m) {
@@ -1132,16 +1139,22 @@ static int mount_device(struct device *dev, int type)
                }
 
                if (m->autofs) {
-                       snprintf(_target, sizeof(_target), "/tmp/run/blockd/%s", device);
+                       if (asprintf(&_target, "/tmp/run/blockd/%s", device) == -1)
+                               exit(ENOMEM);
+
                        target = _target;
                } else if (m->target) {
                        target = m->target;
                } else {
-                       snprintf(_target, sizeof(_target), "/mnt/%s", device);
+                       if (asprintf(&_target, "/mnt/%s", device) == -1)
+                               exit(ENOMEM);
+
                        target = _target;
                }
        } else if (anon_mount) {
-               snprintf(_target, sizeof(_target), "/mnt/%s", device);
+               if (asprintf(&_target, "/mnt/%s", device) == -1)
+                       exit(ENOMEM);
+
                target = _target;
        } else {
                /* No reason to mount this device */
@@ -1153,36 +1166,55 @@ static int mount_device(struct device *dev, int type)
        if (check_fs)
                check_filesystem(pr);
 
-       mkdir_p(target);
+       mkdir_p(target, 0755);
+       if (!lstat(target, &st) && S_ISLNK(st.st_mode))
+               unlink(target);
 
        err = handle_mount(pr->dev, target, pr->type, m);
        if (err) {
                ULOG_ERR("mounting %s (%s) as %s failed (%d) - %m\n",
                                pr->dev, pr->type, target, errno);
+
+               if (_target)
+                       free(_target);
+
                return err;
        }
 
+       if (_target)
+               free(_target);
+
        handle_swapfiles(true);
 
        if (type != TYPE_AUTOFS)
-               hotplug_call_mount("add", device);
+               blockd_notify("mount", device, NULL, NULL);
 
        return 0;
 }
 
 static int umount_device(char *path, int type, bool all)
 {
-       char *mp;
+       char *mp, *devpath;
        int err;
 
-       mp = find_mount_point(path);
+       if (strlen(path) > 5 && !strncmp("/dev/", path, 5)) {
+               mp = find_mount_point(path);
+       } else {
+               devpath = malloc(strlen(path) + 6);
+               strcpy(devpath, "/dev/");
+               strcat(devpath, path);
+               mp = find_mount_point(devpath);
+               free(devpath);
+       }
+
        if (!mp)
                return -1;
-       if (!strcmp(mp, "/") && !all)
+       if (!strcmp(mp, "/") && !all) {
+               free(mp);
                return 0;
-
+       }
        if (type != TYPE_AUTOFS)
-               hotplug_call_mount("remove", basename(path));
+               blockd_notify("umount", basename(path), NULL, NULL);
 
        err = umount2(mp, MNT_DETACH);
        if (err) {
@@ -1199,47 +1231,38 @@ static int umount_device(char *path, int type, bool all)
 
 static int mount_action(char *action, char *device, int type)
 {
-       struct device *the_dev, *dev;
-       char path[32];
+       char *path = NULL;
+       struct probe_info *pr;
 
        if (!action || !device)
                return -1;
 
-       if (config_load(NULL))
-               return -1;
-       cache_load(0);
-
-       the_dev = find_block_device(NULL, NULL, device);
-
        if (!strcmp(action, "remove")) {
                if (type == TYPE_HOTPLUG)
-                       blockd_notify(device, NULL, NULL);
+                       blockd_notify("hotplug", device, NULL, NULL);
+
+               umount_device(device, type, true);
 
-               if (!the_dev || !the_dev->m || the_dev->m->type != TYPE_MOUNT) {
-                       snprintf(path, sizeof(path), "/dev/%s", device);
-                       umount_device(path, type, true);
-               } else
-                       vlist_for_element_to_last_reverse(&devices, the_dev, dev, node)
-                               if (dev->m && dev->m->type == TYPE_MOUNT)
-                                       umount_device(dev->pr->dev, type, true);
                return 0;
-       } else if (!strcmp(action, "add")) {
-               if (!the_dev)
-                       return -1;
-               if (the_dev->m && the_dev->m->type == TYPE_MOUNT) {
-                       vlist_for_first_to_element(&devices, the_dev, dev, node) {
-                               if (dev->m && dev->m->type == TYPE_MOUNT) {
-                                       int err = mount_device(dev, type);
-                                       if (err)
-                                               return err;
-                               }
-                       }
-                       return 0;
-               } else
-                       return mount_device(the_dev, type);
+       } else if (strcmp(action, "add")) {
+               ULOG_ERR("Unkown action %s\n", action);
+
+               return -1;
        }
-       ULOG_ERR("Unkown action %s\n", action);
-       return -1;
+
+       if (config_load(NULL))
+               return -1;
+
+       cache_load(1);
+
+       list_for_each_entry(pr, &devices, list)
+               if (!strcmp(basename(pr->dev), device))
+                       path = pr->dev;
+
+       if (!path)
+               return -1;
+
+       return mount_device(find_block_info(NULL, NULL, path), type);
 }
 
 static int main_hotplug(int argc, char **argv)
@@ -1255,30 +1278,29 @@ static int main_autofs(int argc, char **argv)
                return -1;
 
        if (!strcmp(argv[2], "start")) {
-               struct device *dev;
                struct probe_info *pr;
 
                if (config_load(NULL))
                        return -1;
 
-               cache_load(0);
-               vlist_for_each_element(&devices, dev, node) {
+               cache_load(1);
+               list_for_each_entry(pr, &devices, list) {
                        struct mount *m;
+                       char *mp;
 
-                       pr = dev->pr;
                        if (!strcmp(pr->type, "swap"))
                                continue;
 
-                       m = dev->m;
+                       m = find_block(pr->uuid, pr->label, NULL, NULL);
                        if (m && m->extroot)
                                continue;
 
-                       blockd_notify(pr->dev, m, pr);
+                       blockd_notify("hotplug", pr->dev, m, pr);
+                       if ((!m || !m->autofs) && (mp = find_mount_point(pr->dev))) {
+                               blockd_notify("mount", pr->dev, NULL, NULL);
+                               free(mp);
+                       }
                }
-       } else if (!strcmp(argv[2], "available")) {
-               err = hotplug_call_mount("add", argv[3]);
-       } else if (!strcmp(argv[2], "unavailable")) {
-               err = hotplug_call_mount("remove", argv[3]);
        } else {
                if (argc < 4)
                        return -EINVAL;
@@ -1373,17 +1395,16 @@ static int find_block_ubi_RO(libubi_t libubi, char *name, char *part, int plen)
 
        return err;
 }
+#endif
 
-#else
-
-static int find_root_dev(char *buf, int len)
+static int find_dev(const char *path, char *buf, int len)
 {
        DIR *d;
        dev_t root;
        struct stat s;
        struct dirent *e;
 
-       if (stat("/", &s))
+       if (stat(path, &s))
                return -1;
 
        if (!(d = opendir("/dev")))
@@ -1405,7 +1426,14 @@ static int find_root_dev(char *buf, int len)
        return -1;
 }
 
-#endif
+static int find_root_dev(char *buf, int len)
+{
+       int err = find_dev("/", buf, len);
+       if (err)
+           err = find_dev("/rom", buf, len);
+
+       return err;
+}
 
 static int test_fs_support(const char *name)
 {
@@ -1431,80 +1459,91 @@ static int test_fs_support(const char *name)
        return rv;
 }
 
+/**
+ * Check if mounted partition is a valid extroot
+ *
+ * @path target mount point
+ *
+ * Valid extroot partition has to contain /etc/.extroot-uuid with UUID of root
+ * device. This function reads UUID and verifies it OR writes UUID to
+ * .extroot-uuid if it doesn't exist yet (first extroot usage).
+ */
 static int check_extroot(char *path)
 {
-       struct device *dev;
-       struct probe_info *pr;
+       struct probe_info *pr = NULL;
+       struct probe_info *tmp;
+       struct stat s;
+       char uuid[64] = { 0 };
        char devpath[32];
+       char tag[64];
+       FILE *fp;
+       int err;
 
+       err = find_block_mtd("\"rootfs\"", devpath, sizeof(devpath));
 #ifdef UBIFS_EXTROOT
-       if (find_block_mtd("\"rootfs\"", devpath, sizeof(devpath))) {
-               int err = -1;
+       if (err) {
                libubi_t libubi;
 
                libubi = libubi_open();
                err = find_block_ubi_RO(libubi, "rootfs", devpath, sizeof(devpath));
                libubi_close(libubi);
-               if (err)
-                       return -1;
        }
-#else
-       if (find_block_mtd("\"rootfs\"", devpath, sizeof(devpath))) {
-               if (find_root_dev(devpath, sizeof(devpath))) {
-                       ULOG_ERR("extroot: unable to determine root device\n");
-                       return -1;
+#endif
+       if (err) {
+               err = find_root_dev(devpath, sizeof(devpath));
+       }
+       if (err) {
+               ULOG_ERR("extroot: unable to determine root device\n");
+               return -1;
+       }
+
+       /* Find root device probe_info so we know its UUID */
+       list_for_each_entry(tmp, &devices, list) {
+               if (!strcmp(tmp->dev, devpath)) {
+                       pr = tmp;
+                       break;
                }
        }
-#endif
+       if (!pr) {
+               ULOG_ERR("extroot: unable to lookup root device %s\n", devpath);
+               return -1;
+       }
 
-       vlist_for_each_element(&devices, dev, node) {
-               pr = dev->pr;
-               if (!strcmp(pr->dev, devpath)) {
-                       struct stat s;
-                       FILE *fp = NULL;
-                       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+");
-                               if (!fp) {
-                                       ULOG_ERR("extroot: failed to write UUID to %s: %d (%m)\n",
-                                                tag, errno);
-                                       /* return 0 to continue boot regardless of error */
-                                       return 0;
-                               }
-                               fputs(pr->uuid, fp);
-                               fclose(fp);
-                               return 0;
-                       }
+       snprintf(tag, sizeof(tag), "%s/etc", path);
+       if (stat(tag, &s))
+               mkdir_p(tag, 0755);
 
-                       fp = fopen(tag, "r");
-                       if (!fp) {
-                               ULOG_ERR("extroot: failed to read UUID from %s: %d (%m)\n",
-                                        tag, errno);
-                               return -1;
-                       }
+       snprintf(tag, sizeof(tag), "%s/etc/.extroot-uuid", path);
+       if (stat(tag, &s)) {
+               fp = fopen(tag, "w+");
+               if (!fp) {
+                       ULOG_ERR("extroot: failed to write UUID to %s: %d (%m)\n",
+                                tag, errno);
+                       /* return 0 to continue boot regardless of error */
+                       return 0;
+               }
+               fputs(pr->uuid, fp);
+               fclose(fp);
+               return 0;
+       }
 
-                       if (!fgets(uuid, sizeof(uuid), fp))
-                               ULOG_ERR("extroot: failed to read UUID from %s: %d (%m)\n",
-                                        tag, errno);
-                       fclose(fp);
+       fp = fopen(tag, "r");
+       if (!fp) {
+               ULOG_ERR("extroot: failed to read UUID from %s: %d (%m)\n", tag,
+                        errno);
+               return -1;
+       }
 
-                       if (*uuid && !strcasecmp(uuid, pr->uuid))
-                               return 0;
+       if (!fgets(uuid, sizeof(uuid), fp))
+               ULOG_ERR("extroot: failed to read UUID from %s: %d (%m)\n", tag,
+                        errno);
+       fclose(fp);
 
-                       ULOG_ERR("extroot: UUID mismatch (root: %s, %s: %s)\n",
-                                pr->uuid, basename(path), uuid);
-                       return -1;
-               }
-       }
+       if (*uuid && !strcasecmp(uuid, pr->uuid))
+               return 0;
 
-       ULOG_ERR("extroot: unable to lookup root device %s\n", devpath);
+       ULOG_ERR("extroot: UUID mismatch (root: %s, %s: %s)\n", pr->uuid,
+                basename(path), uuid);
        return -1;
 }
 
@@ -1516,7 +1555,6 @@ static int mount_extroot(char *cfg)
        char overlay[] = "/tmp/extroot/overlay";
        char mnt[] = "/tmp/extroot/mnt";
        char *path = mnt;
-       struct device *dev;
        struct probe_info *pr;
        struct mount *m;
        int err = -1;
@@ -1537,17 +1575,16 @@ static int mount_extroot(char *cfg)
        }
 
        /* Find block device pointed by the mount config */
-       dev = find_block_device(m->uuid, m->label, m->device);
+       pr = find_block_info(m->uuid, m->label, m->device);
 
-       if (!dev && delay_root){
+       if (!pr && delay_root){
                ULOG_INFO("extroot: device not present, retrying in %u seconds\n", delay_root);
                sleep(delay_root);
                make_devs();
                cache_load(1);
-               dev = find_block_device(m->uuid, m->label, m->device);
+               pr = find_block_info(m->uuid, m->label, m->device);
        }
-       if (dev) {
-               pr = dev->pr;
+       if (pr) {
                if (strncmp(pr->type, "ext", 3) &&
                    strncmp(pr->type, "f2fs", 4) &&
                    strncmp(pr->type, "btrfs", 5) &&
@@ -1564,7 +1601,7 @@ static int mount_extroot(char *cfg)
 
                if (m->overlay)
                        path = overlay;
-               mkdir_p(path);
+               mkdir_p(path, 0755);
 
                if (check_fs)
                        check_filesystem(pr);
@@ -1589,8 +1626,15 @@ static int mount_extroot(char *cfg)
        return err;
 }
 
+/**
+ * Look for extroot config and mount it if present
+ *
+ * Look for /etc/config/fstab on all supported partitions and use it for
+ * mounting extroot if specified.
+ */
 static int main_extroot(int argc, char **argv)
 {
+       struct probe_info *pr;
        char blkdev_path[32] = { 0 };
        int err = -1;
 #ifdef UBIFS_EXTROOT
@@ -1611,6 +1655,11 @@ static int main_extroot(int argc, char **argv)
        /* enable LOG_INFO messages */
        ulog_threshold(LOG_INFO);
 
+       /* try the currently mounted overlay if exists */
+       err = mount_extroot("/tmp/overlay");
+       if (!err)
+           return err;
+
        /*
         * Look for "rootfs_data". We will want to mount it and check for
         * extroot configuration.
@@ -1619,15 +1668,15 @@ static int main_extroot(int argc, char **argv)
        /* Start with looking for MTD partition */
        find_block_mtd("\"rootfs_data\"", blkdev_path, sizeof(blkdev_path));
        if (blkdev_path[0]) {
-               struct device *dev = find_block_device(NULL, NULL, blkdev_path);
-               if (dev && !strcmp(dev->pr->type, "jffs2")) {
+               pr = find_block_info(NULL, NULL, blkdev_path);
+               if (pr && !strcmp(pr->type, "jffs2")) {
                        char cfg[] = "/tmp/jffs_cfg";
 
                        /*
                         * Mount MTD part and try extroot (using
                         * /etc/config/fstab from that partition)
                         */
-                       mkdir_p(cfg);
+                       mkdir_p(cfg, 0755);
                        if (!mount(blkdev_path, cfg, "jffs2", MS_NOATIME, NULL)) {
                                err = mount_extroot(cfg);
                                umount2(cfg, MNT_DETACH);
@@ -1649,7 +1698,7 @@ static int main_extroot(int argc, char **argv)
                char cfg[] = "/tmp/ubifs_cfg";
 
                /* Mount volume and try extroot (using fstab from that vol) */
-               mkdir_p(cfg);
+               mkdir_p(cfg, 0755);
                if (!mount(blkdev_path, cfg, "ubifs", MS_NOATIME, NULL)) {
                        err = mount_extroot(cfg);
                        umount2(cfg, MNT_DETACH);
@@ -1661,19 +1710,20 @@ static int main_extroot(int argc, char **argv)
        }
 #endif
 
+       /* As a last resort look for /etc/config/fstab on "rootfs" partition */
        return mount_extroot(NULL);
 }
 
 static int main_mount(int argc, char **argv)
 {
-       struct device *dev;
+       struct probe_info *pr;
 
        if (config_load(NULL))
                return -1;
 
        cache_load(1);
-       vlist_for_each_element(&devices, dev, node)
-               mount_device(dev, TYPE_DEV);
+       list_for_each_entry(pr, &devices, list)
+               mount_device(pr, TYPE_DEV);
 
        handle_swapfiles(true);
 
@@ -1682,7 +1732,6 @@ static int main_mount(int argc, char **argv)
 
 static int main_umount(int argc, char **argv)
 {
-       struct device *dev;
        struct probe_info *pr;
        bool all = false;
 
@@ -1691,19 +1740,18 @@ static int main_umount(int argc, char **argv)
 
        handle_swapfiles(false);
 
-       cache_load(0);
+       cache_load(1);
 
        if (argc == 3)
                all = !strcmp(argv[2], "-a");
 
-       vlist_for_each_element_reverse(&devices, dev, node) {
+       list_for_each_entry(pr, &devices, list) {
                struct mount *m;
 
-               pr = dev->pr;
                if (!strcmp(pr->type, "swap"))
                        continue;
 
-               m = dev->m;
+               m = find_block(pr->uuid, pr->label, basename(pr->dev), NULL);
                if (m && m->extroot)
                        continue;
 
@@ -1715,7 +1763,7 @@ static int main_umount(int argc, char **argv)
 
 static int main_detect(int argc, char **argv)
 {
-       struct device *dev;
+       struct probe_info *pr;
 
        cache_load(0);
        printf("config 'global'\n");
@@ -1725,8 +1773,8 @@ static int main_detect(int argc, char **argv)
        printf("\toption\tauto_mount\t'1'\n");
        printf("\toption\tdelay_root\t'5'\n");
        printf("\toption\tcheck_fs\t'0'\n\n");
-       vlist_for_each_element(&devices, dev, node)
-               print_block_uci(dev->pr);
+       list_for_each_entry(pr, &devices, list)
+               print_block_uci(pr);
 
        return 0;
 }
@@ -1734,12 +1782,12 @@ static int main_detect(int argc, char **argv)
 static int main_info(int argc, char **argv)
 {
        int i;
-       struct device *dev;
+       struct probe_info *pr;
 
        cache_load(1);
        if (argc == 2) {
-               vlist_for_each_element(&devices, dev, node)
-                       print_block_info(dev->pr);
+               list_for_each_entry(pr, &devices, list)
+                       print_block_info(pr);
 
                return 0;
        };
@@ -1755,9 +1803,9 @@ static int main_info(int argc, char **argv)
                        ULOG_ERR("%s is not a block device\n", argv[i]);
                        continue;
                }
-               dev = find_block_device(NULL, NULL, argv[i]);
-               if (dev)
-                       print_block_info(dev->pr);
+               pr = find_block_info(NULL, NULL, argv[i]);
+               if (pr)
+                       print_block_info(pr);
        }
 
        return 0;
@@ -1779,7 +1827,6 @@ static int main_swapon(int argc, char **argv)
        FILE *fp;
        char *lineptr;
        size_t s;
-       struct device *dev;
        struct probe_info *pr;
        int flags = 0;
        int pri;
@@ -1804,8 +1851,7 @@ static int main_swapon(int argc, char **argv)
                        return 0;
                case 'a':
                        cache_load(0);
-                       vlist_for_each_element(&devices, dev, node) {
-                               pr = dev->pr;
+                       list_for_each_entry(pr, &devices, list) {
                                if (strcmp(pr->type, "swap"))
                                        continue;
                                if (swapon(pr->dev, 0))