Merge pull request #1164 from uestczyh222/master

[Components][DFS][RAMFS]Fix bug

components/dfs/filesystems/ramfs/dfs_ramfs.c

@@ -189,8 +189,11 @@ int dfs_ramfs_open(struct dfs_fd *file)
     rt_size_t size;
     struct dfs_ramfs *ramfs;
     struct ramfs_dirent *dirent;
+    struct dfs_filesystem *fs;
 
-    ramfs = (struct dfs_ramfs *)file->data;
+    fs = (struct dfs_filesystem *)file->data;
+
+    ramfs = (struct dfs_ramfs *)fs->data;
     RT_ASSERT(ramfs != NULL);
 
     if (file->flags & O_DIRECTORY)
@@ -456,6 +459,7 @@ struct dfs_ramfs* dfs_ramfs_create(rt_uint8_t *pool, rt_size_t size)
     rt_list_init(&(ramfs->root.list));
     ramfs->root.size = 0;
     strcpy(ramfs->root.name, ".");
+    ramfs->root.fs = ramfs;
 
     return ramfs;
 }