mount_root: keep track of overlay initialization state (via xattr)

[project/fstools.git] / libfstools / overlay.c

diff --git a/libfstools/overlay.c b/libfstools/overlay.c
index 7c9b480..3269a52 100644 (file)
--- a/libfstools/overlay.c
+++ b/libfstools/overlay.c
@@ -14,6 +14,7 @@
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <sys/mount.h>
+#include <sys/syscall.h>
 
 #include <asm/byteorder.h>
 
@@ -34,6 +35,18 @@
 
 static bool keep_sysupgrade;
 
+static ssize_t
+fs_getxattr(const char *path, const char *name, void *value, size_t size)
+{
+       return syscall(__NR_getxattr, path, name, value, size);
+}
+
+static ssize_t
+fs_setxattr(const char *path, const char *name, const void *value, size_t size, int flags)
+{
+       return syscall(__NR_setxattr, path, name, value, size, flags);
+}
+
 static int
 handle_rmdir(const char *dir)
 {
@@ -235,7 +248,13 @@ jffs2_switch(struct volume *v)
                }
                break;
        }
-       return ret;
+
+       if (ret)
+               return ret;
+
+       sync();
+       fs_state_set("/overlay", FS_STATE_READY);
+       return 0;
 }
 
 static int overlay_mount_fs(struct volume *v)
@@ -266,6 +285,28 @@ static int overlay_mount_fs(struct volume *v)
        return -1;
 }
 
+enum fs_state fs_state_get(const char *dir)
+{
+       uint32_t val;
+
+       if (fs_getxattr(dir, "user.fs_state", &val, sizeof(val)) != sizeof(val))
+               return FS_STATE_UNKNOWN;
+
+       if (val > __FS_STATE_LAST)
+               return FS_STATE_UNKNOWN;
+
+       return val;
+}
+
+
+int fs_state_set(const char *dir, enum fs_state state)
+{
+       uint32_t val = state;
+
+       return fs_setxattr(dir, "user.fs_state", &val, sizeof(val), 0);
+}
+
+
 int mount_overlay(struct volume *v)
 {
        char *mp;
@@ -287,6 +328,21 @@ int mount_overlay(struct volume *v)
                return 0;
        }
 
+       switch(fs_state_get("/tmp/overlay")) {
+       case FS_STATE_UNKNOWN:
+               fs_state_set("/tmp/overlay", FS_STATE_PENDING);
+               if (fs_state_get("/tmp/overlay") != FS_STATE_PENDING) {
+                       ULOG_ERR("unable to set filesystem state\n");
+                       break;
+               }
+       case FS_STATE_PENDING:
+               ULOG_INFO("overlay filesystem has not been fully initialized yet\n");
+               overlay_delete("/tmp/overlay", true);
+               break;
+       case FS_STATE_READY:
+               break;
+       }
+
        ULOG_INFO("switching to jffs2 overlay\n");
        if (mount_move("/tmp", "", "/overlay") || fopivot("/overlay", "/rom")) {
                ULOG_ERR("switching to jffs2 failed - fallback to ramoverlay\n");