[fix][dfs] 增加文件系统操作的类型检查，防止类型不匹配导致数据结构不一致引发的异常

Author: Unbear-Hz

components/dfs/dfs_v1/filesystems/elmfat/dfs_elm.c

@@ -588,6 +588,11 @@ int dfs_elm_flush(struct dfs_file *file)
     FIL *fd;
     FRESULT result;
 
+    if (file->vnode->type == FT_DIRECTORY)
+    {
+        return -EISDIR;
+    }
+
     fd = (FIL *)(file->data);
     RT_ASSERT(fd != RT_NULL);
 

components/dfs/dfs_v1/src/dfs_posix.c

@@ -460,6 +460,11 @@ int fsync(int fildes)
     }
 
     ret = dfs_file_flush(d);
+    if (ret < 0)
+    {
+        rt_set_errno(ret);
+        return -1;
+    }
 
     return ret;
 }

components/dfs/dfs_v2/filesystems/elmfat/dfs_elm.c

@@ -623,6 +623,11 @@ int dfs_elm_flush(struct dfs_file *file)
     FIL *fd;
     FRESULT result;
 
+    if (file->vnode->type == FT_DIRECTORY)
+    {
+        return -EISDIR;
+    }
+
     fd = (FIL *)(file->vnode->data);
     RT_ASSERT(fd != RT_NULL);
 

components/dfs/dfs_v2/src/dfs_file.c

@@ -2202,6 +2202,7 @@ int dfs_file_rename(const char *old_file, const char *new_file)
  * @return int Operation result:
  *         - 0 on success
  *         -EBADF if invalid file descriptor
+ *         -EISDIR if the file is a directory (directories cannot be truncated)
  *         -ENOSYS if truncate operation not supported
  *         -EINVAL if invalid parameters or not mounted
  *
@@ -2214,6 +2215,11 @@ int dfs_file_ftruncate(struct dfs_file *file, off_t length)
 
     if (file)
     {
+        if (file->vnode->type == FT_DIRECTORY)
+        {
+            return -EISDIR;
+        }
+
         if (file->fops->truncate)
         {
             if (dfs_is_mounted(file->vnode->mnt) == 0)

components/dfs/dfs_v2/src/dfs_posix.c

@@ -605,6 +605,11 @@ int fsync(int fildes)
     }
 
     ret = dfs_file_fsync(file);
+    if (ret < 0)
+    {
+        rt_set_errno(ret);
+        return -1;
+    }
 
     return ret;
 }