mount_root: use symlink instead of xattr to store initialization state

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

diff --git a/libfstools/overlay.c b/libfstools/overlay.c
index 0677c34..62a99f8 100644 (file)
--- a/libfstools/overlay.c
+++ b/libfstools/overlay.c
@@ -14,7 +14,6 @@
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <sys/mount.h>
-#include <sys/syscall.h>
 
 #include <asm/byteorder.h>
 
@@ -35,18 +34,6 @@
 
 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)
 {
@@ -290,11 +277,20 @@ static int overlay_mount_fs(struct volume *v)
 
 enum fs_state fs_state_get(const char *dir)
 {
+       char *path;
+       char valstr[16];
        uint32_t val;
+       ssize_t len;
 
-       if (fs_getxattr(dir, "user.fs_state", &val, sizeof(val)) != sizeof(val))
+       path = alloca(strlen(dir) + 1 + sizeof("/.fs_state"));
+       sprintf(path, "%s/.fs_state", dir);
+       len = readlink(path, valstr, sizeof(valstr) - 1);
+       if (len < 0)
                return FS_STATE_UNKNOWN;
 
+       valstr[len] = 0;
+       val = atoi(valstr);
+
        if (val > __FS_STATE_LAST)
                return FS_STATE_UNKNOWN;
 
@@ -304,9 +300,15 @@ enum fs_state fs_state_get(const char *dir)
 
 int fs_state_set(const char *dir, enum fs_state state)
 {
-       uint32_t val = state;
+       char valstr[16];
+       char *path;
+
+       path = alloca(strlen(dir) + 1 + sizeof("/.fs_state"));
+       sprintf(path, "%s/.fs_state", dir);
+       unlink(path);
+       snprintf(valstr, sizeof(valstr), "%d", state);
 
-       return fs_setxattr(dir, "user.fs_state", &val, sizeof(val), 0);
+       return symlink(valstr, path);
 }