fstools: add btrfs support

[project/fstools.git] / mount_root.c

diff --git a/mount_root.c b/mount_root.c
index c1524a4..dffb0a6 100644 (file)
--- a/mount_root.c
+++ b/mount_root.c
@@ -12,46 +12,74 @@
  */
 
 #include <sys/mount.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
 #include <stdio.h>
 #include <stdlib.h>
 
+#include <libubox/ulog.h>
+
 #include "libfstools/libfstools.h"
 #include "libfstools/volume.h"
 
+/*
+ * Called in the early (PREINIT) stage, when we immediately need some writable
+ * filesystem.
+ */
 static int
 start(int argc, char *argv[1])
 {
-       struct volume *v = volume_find("rootfs_data");
+       struct volume *root;
+       struct volume *data = volume_find("rootfs_data");
+       struct stat s;
 
-       if (!getenv("PREINIT"))
+       if (!getenv("PREINIT") && stat("/tmp/.preinit", &s))
                return -1;
 
-       if (!v) {
-               v = volume_find("rootfs");
-               volume_init(v);
-               fprintf(stderr, "mounting /dev/root\n");
+       if (!data) {
+               root = volume_find("rootfs");
+               volume_init(root);
+               ULOG_NOTE("mounting /dev/root\n");
                mount("/dev/root", "/", NULL, MS_NOATIME | MS_REMOUNT, 0);
-               return 0;
        }
 
+       /*
+        * Before trying to mount and use "rootfs_data" let's check if there is
+        * extroot configured. Following call will handle reading config from
+        * the "rootfs_data" on its own.
+        */
        extroot_prefix = "";
        if (!mount_extroot()) {
-               fprintf(stderr, "fs-state: switched to extroot\n");
+               ULOG_NOTE("switched to extroot\n");
                return 0;
        }
 
-       switch (volume_identify(v)) {
+       /* There isn't extroot, so just try to mount "rootfs_data" */
+       volume_init(data);
+       switch (volume_identify(data)) {
        case FS_NONE:
+               ULOG_WARN("no usable overlay filesystem found, using tmpfs overlay\n");
+               return ramoverlay();
+
        case FS_DEADCODE:
+               /*
+                * Filesystem isn't ready yet and we are in the preinit, so we
+                * can't afford waiting for it. Use tmpfs for now and handle it
+                * properly in the "done" call.
+                */
+               ULOG_NOTE("jffs2 not ready yet, using temporary tmpfs overlay\n");
                return ramoverlay();
 
+       case FS_EXT4:
+       case FS_F2FS:
        case FS_JFFS2:
        case FS_UBIFS:
-               mount_overlay(v);
+               mount_overlay(data);
                break;
 
        case FS_SNAPSHOT:
-               mount_snapshot(v);
+               mount_snapshot(data);
                break;
        }
 
@@ -67,6 +95,9 @@ stop(int argc, char *argv[1])
        return 0;
 }
 
+/*
+ * Called at the end of init, it can wait for filesystem if needed.
+ */
 static int
 done(int argc, char *argv[1])
 {
@@ -79,6 +110,13 @@ done(int argc, char *argv[1])
        case FS_NONE:
        case FS_DEADCODE:
                return jffs2_switch(v);
+
+       case FS_EXT4:
+       case FS_F2FS:
+       case FS_JFFS2:
+       case FS_UBIFS:
+               fs_state_set("/overlay", FS_STATE_READY);
+               break;
        }
 
        return 0;
@@ -88,6 +126,8 @@ int main(int argc, char **argv)
 {
        if (argc < 2)
                return start(argc, argv);
+       if (!strcmp(argv[1], "ram"))
+               return ramoverlay();
        if (!strcmp(argv[1], "stop"))
                return stop(argc, argv);
        if (!strcmp(argv[1], "done"))