libblkid-tiny: add exfat superblock support
[project/fstools.git] / block.c
diff --git a/block.c b/block.c
index 0671aca6d0f8231ba9f790859b513ffd75735929..4b45200ad3812f5b79bda5d53c72a13ca5e92636 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"
@@ -480,21 +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 probe_info *pr;
+       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);
-               list_for_each_entry(pr, &devices, list)
-                       if (!strcasecmp(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)
@@ -532,27 +592,10 @@ static void cache_load(int mtd)
        _cache_load("/dev/nvme*");
        _cache_load("/dev/vd*");
        _cache_load("/dev/xvd*");
-       _cache_load("/dev/mapper/*");
+       _cache_load("/dev/dm-*");
 }
 
 
-static int print_block_uci(struct probe_info *pr)
-{
-       if (!strcmp(pr->type, "swap")) {
-               printf("config 'swap'\n");
-       } else {
-               printf("config 'mount'\n");
-               printf("\toption\ttarget\t'/mnt/%s'\n", basename(pr->dev));
-       }
-       if (pr->uuid)
-               printf("\toption\tuuid\t'%s'\n", pr->uuid);
-       else
-               printf("\toption\tdevice\t'%s'\n", pr->dev);
-       printf("\toption\tenabled\t'0'\n\n");
-
-       return 0;
-}
-
 static struct probe_info* find_block_info(char *uuid, char *label, char *path)
 {
        struct probe_info *pr = NULL;
@@ -579,7 +622,6 @@ static char* find_mount_point(char *block)
 {
        FILE *fp = fopen("/proc/self/mountinfo", "r");
        static char line[256];
-       int len = strlen(block);
        char *point = NULL, *pos, *tmp, *cpoint, *devname;
        struct stat s;
        int rstat;
@@ -643,7 +685,7 @@ static char* find_mount_point(char *block)
 
                *pos = '\0';
                devname = tmp;
-               if (!strncmp(block, devname, len)) {
+               if (!strcmp(block, devname)) {
                        point = strdup(cpoint);
                        break;
                }
@@ -666,6 +708,30 @@ static char* find_mount_point(char *block)
        return point;
 }
 
+static int print_block_uci(struct probe_info *pr)
+{
+       if (!strcmp(pr->type, "swap")) {
+               printf("config 'swap'\n");
+       } else {
+               char *mp = find_mount_point(pr->dev);
+
+               printf("config 'mount'\n");
+               if (mp) {
+                       printf("\toption\ttarget\t'%s'\n", mp);
+                       free(mp);
+               } else {
+                       printf("\toption\ttarget\t'/mnt/%s'\n", basename(pr->dev));
+               }
+       }
+       if (pr->uuid)
+               printf("\toption\tuuid\t'%s'\n", pr->uuid);
+       else
+               printf("\toption\tdevice\t'%s'\n", pr->dev);
+       printf("\toption\tenabled\t'0'\n\n");
+
+       return 0;
+}
+
 static int print_block_info(struct probe_info *pr)
 {
        static char *mp;
@@ -691,25 +757,13 @@ 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;
        struct stat statbuf;
        const char *e2fsck = "/usr/sbin/e2fsck";
        const char *f2fsck = "/usr/sbin/fsck.f2fs";
-       const char *dosfsck = "/usr/sbin/dosfsck";
+       const char *fatfsck = "/usr/sbin/fsck.fat";
        const char *btrfsck = "/usr/bin/btrfsck";
        const char *ntfsck = "/usr/bin/ntfsfix";
        const char *ckfs;
@@ -719,7 +773,7 @@ static void check_filesystem(struct probe_info *pr)
                return;
 
        if (!strncmp(pr->type, "vfat", 4)) {
-               ckfs = dosfsck;
+               ckfs = fatfsck;
        } else if (!strncmp(pr->type, "f2fs", 4)) {
                ckfs = f2fsck;
        } else if (!strncmp(pr->type, "ext", 3)) {
@@ -880,15 +934,34 @@ static int exec_mount(const char *source, const char *target,
        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;
+       }
+
+       for (i = 0; i < count; i++) {
+               const char *fs = filesystems[i];
 
-       err = mount(source, target, fstype, m ? m->flags : 0,
-                   (m && m->options) ? m->options : "");
+               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. */
@@ -925,19 +998,29 @@ 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 void 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;
+       int err;
 
        if (!ctx)
-               return;
+               return -ENXIO;
 
        if (!ubus_lookup_id(ctx, "block", &id)) {
                struct blob_buf buf = { 0 };
@@ -983,17 +1066,25 @@ static void blockd_notify(char *device, struct mount *m, struct probe_info *pr)
                        blobmsg_add_u32(&buf, "remove", 1);
                }
 
-               ubus_invoke(ctx, id, "hotplug", buf.head, NULL, NULL, 3000);
+               err = ubus_invoke(ctx, id, method, buf.head, NULL, NULL, 3000);
+       } else {
+               err = -ENOENT;
        }
 
        ubus_free(ctx);
+
+       return err;
 }
 
 static int mount_device(struct probe_info *pr, int type)
 {
        struct mount *m;
+       struct stat st;
+       char *_target = NULL;
+       char *target;
        char *device;
        char *mp;
+       int err;
 
        if (!pr)
                return -1;
@@ -1010,25 +1101,26 @@ static int mount_device(struct probe_info *pr, int type)
                return 0;
        }
 
-       mp = find_mount_point(pr->dev);
-       if (mp && (type != TYPE_HOTPLUG)) {
-               ULOG_ERR("%s is already mounted on %s\n", pr->dev, mp);
-               free(mp);
-               return -1;
-       }
-
        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 && m->target && strcmp(m->target, mp)) {
+                       ULOG_ERR("%s is already mounted on %s\n", pr->dev, mp);
+                       err = -1;
+               } else
+                       err = 0;
+               free(mp);
+               return err;
+       }
+
        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) {
-               char _target[32];
-               char *target;
-               int err = 0;
-
                switch (type) {
                case TYPE_HOTPLUG:
                        if (m->autofs)
@@ -1047,78 +1139,91 @@ static int mount_device(struct probe_info *pr, 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;
                }
-               mkdir_p(target);
-
-               if (check_fs)
-                       check_filesystem(pr);
+       } else if (anon_mount) {
+               if (asprintf(&_target, "/mnt/%s", device) == -1)
+                       exit(ENOMEM);
 
-               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);
-               else
-                       handle_swapfiles(true);
-               return err;
+               target = _target;
+       } else {
+               /* No reason to mount this device */
+               return 0;
        }
 
-       if (anon_mount) {
-               char target[32];
-               int err = 0;
+       /* Mount the device */
 
-               snprintf(target, sizeof(target), "/mnt/%s", device);
-               mkdir_p(target);
+       if (check_fs)
+               check_filesystem(pr);
 
-               if (check_fs)
-                       check_filesystem(pr);
+       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);
 
-               err = handle_mount(pr->dev, target, pr->type, NULL);
-               if (err)
-                       ULOG_ERR("mounting %s (%s) as %s failed (%d) - %m\n",
-                                pr->dev, pr->type, target, errno);
-               else
-                       handle_swapfiles(true);
                return err;
        }
 
+       if (_target)
+               free(_target);
+
+       handle_swapfiles(true);
+
+       if (type != TYPE_AUTOFS)
+               blockd_notify("mount", device, NULL, NULL);
+
        return 0;
 }
 
-static int umount_device(struct probe_info *pr)
+static int umount_device(char *path, int type, bool all)
 {
-       struct mount *m;
-       char *device = basename(pr->dev);
-       char *mp;
+       char *mp, *devpath;
        int err;
 
-       if (!pr)
-               return -1;
-
-       if (!strcmp(pr->type, "swap"))
-               return -1;
+       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);
+       }
 
-       mp = find_mount_point(pr->dev);
        if (!mp)
                return -1;
-
-       m = find_block(pr->uuid, pr->label, device, NULL);
-       if (m && m->extroot)
-               return -1;
+       if (!strcmp(mp, "/") && !all) {
+               free(mp);
+               return 0;
+       }
+       if (type != TYPE_AUTOFS)
+               blockd_notify("umount", basename(path), NULL, NULL);
 
        err = umount2(mp, MNT_DETACH);
-       if (err)
-               ULOG_ERR("unmounting %s (%s)  failed (%d) - %m\n",
-                        pr->dev, mp, errno);
-       else
-               ULOG_INFO("unmounted %s (%s)\n",
-                         pr->dev, mp);
+       if (err) {
+               ULOG_ERR("unmounting %s (%s) failed (%d) - %m\n", path, mp,
+                        errno);
+       } else {
+               ULOG_INFO("unmounted %s (%s)\n", path, mp);
+               rmdir(mp);
+       }
 
        free(mp);
        return err;
@@ -1126,28 +1231,18 @@ static int umount_device(struct probe_info *pr)
 
 static int mount_action(char *action, char *device, int type)
 {
-       char path[32];
-       char *mount_point;
+       char *path = NULL;
+       struct probe_info *pr;
 
        if (!action || !device)
                return -1;
-       snprintf(path, sizeof(path), "/dev/%s", device);
 
        if (!strcmp(action, "remove")) {
-               int err = 0;
-
                if (type == TYPE_HOTPLUG)
-                       blockd_notify(device, NULL, NULL);
+                       blockd_notify("hotplug", device, NULL, NULL);
 
-               mount_point = find_mount_point(path);
-               if (mount_point)
-                       err = umount2(mount_point, MNT_DETACH);
+               umount_device(device, type, true);
 
-               if (err)
-                       ULOG_ERR("umount of %s failed (%d) - %m\n",
-                                mount_point, errno);
-
-               free(mount_point);
                return 0;
        } else if (strcmp(action, "add")) {
                ULOG_ERR("Unkown action %s\n", action);
@@ -1157,7 +1252,15 @@ static int mount_action(char *action, char *device, int type)
 
        if (config_load(NULL))
                return -1;
-       cache_load(0);
+
+       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);
 }
@@ -1169,6 +1272,8 @@ static int main_hotplug(int argc, char **argv)
 
 static int main_autofs(int argc, char **argv)
 {
+       int err = 0;
+
        if (argc < 3)
                return -1;
 
@@ -1178,18 +1283,36 @@ static int main_autofs(int argc, char **argv)
                if (config_load(NULL))
                        return -1;
 
-               cache_load(0);
+               cache_load(1);
                list_for_each_entry(pr, &devices, list) {
-                       struct mount *m = find_block(pr->uuid, pr->label, NULL, NULL);
+                       struct mount *m;
+                       char *mp;
 
-                       if (m && m->autofs)
-                               mount_device(pr, TYPE_HOTPLUG);
-                       else
-                               blockd_notify(pr->dev, m, pr);
+                       if (!strcmp(pr->type, "swap"))
+                               continue;
+
+                       m = find_block(pr->uuid, pr->label, NULL, NULL);
+                       if (m && m->extroot)
+                               continue;
+
+                       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);
+                       }
                }
-               return 0;
+       } else {
+               if (argc < 4)
+                       return -EINVAL;
+
+               err = mount_action(argv[2], argv[3], TYPE_AUTOFS);
        }
-       return mount_action(argv[2], argv[3], TYPE_AUTOFS);
+
+       if (err) {
+               ULOG_ERR("autofs: \"%s\" action has failed: %d\n", argv[2], err);
+       }
+
+       return err;
 }
 
 static int find_block_mtd(char *name, char *part, int plen)
@@ -1272,8 +1395,7 @@ static int find_block_ubi_RO(libubi_t libubi, char *name, char *part, int plen)
 
        return err;
 }
-
-#else
+#endif
 
 static int find_root_dev(char *buf, int len)
 {
@@ -1304,8 +1426,6 @@ static int find_root_dev(char *buf, int len)
        return -1;
 }
 
-#endif
-
 static int test_fs_support(const char *name)
 {
        char line[128], *p;
@@ -1330,78 +1450,91 @@ 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 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;
+       }
 
-       list_for_each_entry(pr, &devices, list) {
-               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;
 }
 
@@ -1439,7 +1572,7 @@ static int mount_extroot(char *cfg)
                ULOG_INFO("extroot: device not present, retrying in %u seconds\n", delay_root);
                sleep(delay_root);
                make_devs();
-               cache_load(0);
+               cache_load(1);
                pr = find_block_info(m->uuid, m->label, m->device);
        }
        if (pr) {
@@ -1459,7 +1592,7 @@ static int mount_extroot(char *cfg)
 
                if (m->overlay)
                        path = overlay;
-               mkdir_p(path);
+               mkdir_p(path, 0755);
 
                if (check_fs)
                        check_filesystem(pr);
@@ -1484,6 +1617,12 @@ 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;
@@ -1523,7 +1662,7 @@ static int main_extroot(int argc, char **argv)
                         * 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);
@@ -1545,7 +1684,7 @@ 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);
@@ -1557,6 +1696,7 @@ 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);
 }
 
@@ -1579,15 +1719,30 @@ static int main_mount(int argc, char **argv)
 static int main_umount(int argc, char **argv)
 {
        struct probe_info *pr;
+       bool all = false;
 
        if (config_load(NULL))
                return -1;
 
        handle_swapfiles(false);
 
-       cache_load(0);
-       list_for_each_entry(pr, &devices, list)
-               umount_device(pr);
+       cache_load(1);
+
+       if (argc == 3)
+               all = !strcmp(argv[2], "-a");
+
+       list_for_each_entry(pr, &devices, list) {
+               struct mount *m;
+
+               if (!strcmp(pr->type, "swap"))
+                       continue;
+
+               m = find_block(pr->uuid, pr->label, basename(pr->dev), NULL);
+               if (m && m->extroot)
+                       continue;
+
+               umount_device(pr->dev, TYPE_DEV, all);
+       }
 
        return 0;
 }
@@ -1697,7 +1852,6 @@ static int main_swapon(int argc, char **argv)
                default:
                        return swapon_usage();
                }
-
        }
 
        if (optind != (argc - 1))