删除文件夹时回收dentry缓存

kernel/filesystem/VFS/dcache.c

@@ -1,19 +1,83 @@
 #include "internal.h"
+#include <common/kfifo.h>
+#include <debug/bug.h>
 
 /**
  * @brief 释放dentry
- * 
+ *
  * @param dentry 目标dentry
  */
-void vfs_dentry_put(struct vfs_dir_entry_t * dentry)
+void vfs_dentry_put(struct vfs_dir_entry_t *dentry)
 {
+    int retval = 0;
+    uint64_t in_value = 0;
     // todo: 加锁、放锁
 
-    list_del(&dentry->child_node_list);// 从父dentry中删除
+    // 创建一个用来存放指向dentry的指针的fifo队列
+    struct kfifo_t fifo;
+    // 暂时假设队列大小为1024个元素
+    // todo: 实现队列的自动扩容功能
+    retval = kfifo_alloc(&fifo, 1024 * sizeof(uint64_t), 0);
 
-    // todo: 清除子目录的dentry
+    if (retval != 0)
+        goto failed;
 
-    dentry->dir_ops->release(dentry);
+    // 将根dentry加入队列
+    in_value = (uint64_t)dentry;
+    kfifo_in(&fifo, &in_value, sizeof(uint64_t));
+    list_del(&dentry->child_node_list); // 从父dentry中删除
 
-    kfree(dentry);
+    while (!kfifo_empty(&fifo))
+    {
+        // 取出队列中的下一个元素
+        kfifo_out(&fifo, &dentry, sizeof(uint64_t));
+        BUG_ON(dentry == NULL);
+        struct List *list = &dentry->subdirs_list;
+        if (!list_empty(list))
+        {
+            // 将当前dentry下的所有dentry加入队列
+            do
+            {
+                list = list_next(list);
+                in_value = (uint64_t)container_of(list, struct vfs_dir_entry_t, child_node_list);
+                if (in_value != NULL)
+                    kfifo_in(&fifo, &in_value, sizeof(uint64_t));
+
+            } while (list_next(list) != (&dentry->subdirs_list));
+        }
+
+        // 释放inode
+        vfs_free_inode(dentry->dir_inode);
+
+        // 若当前dentry是否为挂载点，则umount
+        if (is_local_mountpoint(dentry))
+            do_umount(dentry);
+
+        dentry->dir_ops->release(dentry);
+        kfree(dentry);
+    }
+    kfifo_free_alloc(&fifo);
+    return;
+failed:;
+    if (fifo.buffer != NULL)
+        kfifo_free_alloc(&fifo);
+    kerror("dentry_put failed.");
+}
+
+/**
+ * @brief 释放inode
+ *
+ * @param inode 待释放的inode
+ * @return int 错误码
+ */
+int vfs_free_inode(struct vfs_index_node_t *inode)
+{
+    --inode->ref_count;
+    BUG_ON(inode->ref_count < 0);
+    if (inode->ref_count == 0)
+    {
+        kfree(inode->private_inode_info);
+        kfree(inode);
+    }
+    return 0;
 }