diff --git a/fs/ext2/ext2_dentry.cpp b/fs/ext2/ext2_dentry.cpp
index 3f89a69..0970631 100644
--- a/fs/ext2/ext2_dentry.cpp
+++ b/fs/ext2/ext2_dentry.cpp
@@ -126,7 +126,7 @@ void EXT2_DEntry::write_children() {
     }
 }
 
-void EXT2_DEntry::mkdir(const std::string& new_name) {
+VFS::DEntry* EXT2_DEntry::mkdir(const std::string& new_name) {
     if (type != VFS::Directory)
         _error(type);
     EXT2_GD *new_dir_gd = nullptr;
@@ -188,12 +188,14 @@ void EXT2_DEntry::mkdir(const std::string& new_name) {
     // ext2_fs->sb->
     ext2_fs->write_gdt();
     ext2_fs->write_super();
+    return new_entry;
 }
 
-void EXT2_DEntry::create(const std::string& name) {
+VFS::DEntry *EXT2_DEntry::create(const std::string& name) {
     if (type != VFS::Directory)
         _error(type);
     _pos();
+    inflate();
     _u32 new_i_n = ext2_fs->alloc_inode();
     _error(new_i_n == 0);
     EXT2::Inode *new_disk_i = new EXT2::Inode();
@@ -212,13 +214,13 @@ void EXT2_DEntry::create(const std::string& name) {
     new_i->write_inode();  // 新Inode写入磁盘
     EXT2_DEntry *new_entry = new EXT2_DEntry(ext2_fs, this, new_i_n, VFS::RegularFile, name);
     new_entry->ext2_inode = new_i;
-
     load_children();
     children.push_back(new_entry);
     write_children();
 
     ext2_fs->write_gdt();
     ext2_fs->write_super();
+    return new_entry;
 }
 
 VFS::File *EXT2_DEntry::get_file() {
@@ -290,10 +292,10 @@ void EXT2_DEntry::unlink_children() {
     _dbg_log("unlink chlidren current %d. finish", inode_n);
 }
 
-void EXT2_DEntry::link(DEntry *tar, const std::string& s) {
+VFS::DEntry *EXT2_DEntry::link(DEntry *tar, const std::string& s) {
     if (tar->fs != fs) {
         _log_info("[EXT2]: Hard Link must in the same file system.");
-        return;
+        return nullptr;
     }
     EXT2_DEntry *t = dynamic_cast<EXT2_DEntry*>(tar);
     std::string ts;
@@ -308,11 +310,13 @@ void EXT2_DEntry::link(DEntry *tar, const std::string& s) {
     inflate();
     ext2_inode->i->links_count++;
     ext2_inode->write_inode();
+    return new_e;
 }
 
-void EXT2_DEntry::move(DEntry *dir, const std::string& new_name) {
-    link(dir, new_name);  // 在dir中创建item的硬链接
+VFS::DEntry *EXT2_DEntry::move(DEntry *dir, const std::string& new_name) {
+    auto ans = link(dir, new_name);  // 在dir中创建item的硬链接
     parent->unlink(this);  // 在父目录中删除自己
+    return ans;
 }
 
 bool EXT2_DEntry::empty() {
@@ -320,6 +324,19 @@ bool EXT2_DEntry::empty() {
     return children.size() == 2;
 }
 
+VFS::DEntry* EXT2_DEntry::copy(DEntry *dir, const std::string& new_name) {
+    VFS::DEntry *new_entry = dir->create(new_name==""?this->name:new_name);
+    VFS::File *old_f = this->open();
+    VFS::File *new_f = new_entry->open();
+    _u8 buf[old_f->size];
+    old_f->read(buf, old_f->size);
+    new_f->write(buf, old_f->size);
+    // dynamic_cast<EXT2_DEntry*>(new_entry)->ext2_inode->write_inode();
+    delete old_f;
+    delete new_f;
+    return new_entry;
+}
+
 
 EXT2_DEntry::~EXT2_DEntry() {
     delete inode;
diff --git a/fs/ext2/ext2_dentry.h b/fs/ext2/ext2_dentry.h
index 0bf1013..8a0e590 100644
--- a/fs/ext2/ext2_dentry.h
+++ b/fs/ext2/ext2_dentry.h
@@ -25,17 +25,20 @@ namespace EXT2
         void inflate();
         void load_children();
 
-        void mkdir(const std::string& name);
-        void create(const std::string& name);
+        VFS::DEntry* mkdir(const std::string& name);
+        VFS::DEntry* create(const std::string& name);
         void unlink(VFS::DEntry *d);  // 删除子项目
         void unlink();  // 删除自己
         void unlink_children();
         // 在tar中创建自己的硬链接
-        void link(DEntry *tar, const std::string& s="");
+        VFS::DEntry *link(DEntry *tar, const std::string& s="");
         // 将本目录中的item移动到另一个目录中
-        void move(DEntry *dir, const std::string& new_name="");
+        VFS::DEntry *move(DEntry *dir, const std::string& new_name="");
         bool empty();
 
+        VFS::DEntry* copy(DEntry *dir, const std::string& new_name);
+
+
 
         ~EXT2_DEntry();
     };
diff --git a/fs/ext2/ext2_file.cpp b/fs/ext2/ext2_file.cpp
index de0b7b1..abc7865 100644
--- a/fs/ext2/ext2_file.cpp
+++ b/fs/ext2/ext2_file.cpp
@@ -79,8 +79,11 @@ _u32 EXT2_File::read(_u8 *buf, _u32 len) {
 }
 
 _u32 EXT2_File::write(_u8 *buf, _u32 len) {
+    if (len + pos > size)
+        resize(len + pos);
+    ext2_inode->print();
     _u32 write_len = 0, this_write_len;
-   _u32 block_size = ext2_fs->block_size;  // 块大小
+    _u32 block_size = ext2_fs->block_size;  // 块大小
     _u32 byte_in_block = pos % block_size;  // 第一个字节在块中的位置
     _u32 nth_block = pos / block_size;  // 第一个字节在第n个块，pos以0开始计数，不需要加1
     auto it = ext2_inode->iter_at(nth_block);
@@ -134,7 +137,9 @@ void EXT2_File::resize(_u32 new_size) {
         }
     }
     size = new_size;
+    ext2_inode->size = size;
     ext2_inode->blocks = target_block;
+    ext2_inode->write_inode();
     ext2_fs->write_gdt();
     ext2_fs->write_super();
 }
\ No newline at end of file
diff --git a/fs/ext2/ext2_fs.cpp b/fs/ext2/ext2_fs.cpp
index dd4764c..3828aab 100644
--- a/fs/ext2/ext2_fs.cpp
+++ b/fs/ext2/ext2_fs.cpp
@@ -125,7 +125,7 @@ _u32 EXT2_FS::alloc_inode(EXT2_GD **ret_gd) {
     for (EXT2_GD* gdd: gdt_list) {
         _u32 t = gdd->alloc_inode();
         if (t != 0) {
-            // _si(t);
+            _si(t);
             sb->free_inodes_count--;
             if (ret_gd != nullptr)
                 *ret_gd = gdd;
diff --git a/fs/ext2/ext2_group_descriptor.cpp b/fs/ext2/ext2_group_descriptor.cpp
index 504f4dc..016c8d2 100644
--- a/fs/ext2/ext2_group_descriptor.cpp
+++ b/fs/ext2/ext2_group_descriptor.cpp
@@ -48,7 +48,6 @@ _u8 *EXT2_GD::get_block_bitmap() {
 _u32 EXT2_GD::alloc_inode() {
     if (gd->free_inodes_count == 0)
         return 0;
-    _pos();
     get_inode_bitmap();
     for (int i = 0; i < fs->block_size; i++) {
         if (inode_bitmap[i] != (_u8)0xff) {
diff --git a/fs/ext2/ext2_inode.cpp b/fs/ext2/ext2_inode.cpp
index 5ee8942..475e921 100644
--- a/fs/ext2/ext2_inode.cpp
+++ b/fs/ext2/ext2_inode.cpp
@@ -32,7 +32,7 @@ void EXT2_Inode::print() {
 
 EXT2_Inode::EXT2_Inode(EXT2_FS *fs, _u32 n, EXT2::Inode *i): VFS::Inode(fs) {
     this->i = i;
-    ino = 0;
+    ino = n;
     counter = 0;
     mode = i->mode;
     nlink = i->links_count;
@@ -49,9 +49,10 @@ EXT2_Inode::EXT2_Inode(EXT2_FS *fs, _u32 n, EXT2::Inode *i): VFS::Inode(fs) {
     inode_n = n;
     ext2_fs = fs;
     blocks = i->blocks / (ext2_fs->block_size / 512);
-    bytes = size % blocks;
-    for (int t = blocks; t < N_BLOCKS; t++)
+    bytes = size % ext2_fs->block_size;
+    for (int t = blocks; t < N_BLOCKS; t++) {
         i->block[t] = 0;
+    }
 }
 
 _u32 EXT2_Inode::byte_in_block(_u32 b) {
@@ -99,6 +100,7 @@ void EXT2_Inode::write_inode() {
     _u32 inode_pos = ext2_fs->inode_to_pos(inode_n);
     MM::Buf buf(sizeof(EXT2::Inode));
     i->blocks = blocks * (ext2_fs->block_size / 512);
+    i->size = size;
     memcpy(buf.data, i, sizeof(EXT2::Inode));
     // _sa(buf.data, sizeof(EXT2::Inode));
     ext2_fs->dev->write(buf, inode_pos, sizeof(EXT2::Inode));
@@ -213,6 +215,7 @@ void EXT2_Inode::iterator::load_buf(int t) {
 }
 
 void EXT2_Inode::iterator::write_back() {
+    _dbg_log("write back");
     if (dirty[0]) {
         memcpy(inode->i->block, block_buf[0], sizeof(_u32) * EXT2::N_BLOCKS);
         dirty[0] = false;
diff --git a/fs/test_fs.cpp b/fs/test_fs.cpp
index 1aeaa2f..5ba7d1a 100644
--- a/fs/test_fs.cpp
+++ b/fs/test_fs.cpp
@@ -233,6 +233,26 @@ VFS::DEntry *mv(VFS::DEntry *cwd, const std::vector<std::string>& cmdd) {
     return cwd;
 }
 
+VFS::DEntry *cp(VFS::DEntry *cwd, const std::vector<std::string>& cmdd) {
+    using namespace VFS;
+    VFS::NameI *from = parse_path(cmdd[cmdd.size() - 2]);
+
+    DEntry *fe = cwd->get_child(from);
+    if (fe == nullptr) {
+        _log_info("%s is not exists.", cmdd[1].c_str());
+        return cwd;
+    }
+    DEntry *te;
+    std::string s;
+    NameI *target = parse_path(cmdd[cmdd.size() - 1]);
+    if ((te = cwd->get_path(target, &s)) == nullptr) {
+        _log_info("%s is already exists.", cmdd[2].c_str());
+        return cwd;
+    }
+    fe->copy(te, s);
+    return cwd;
+}
+
 OP ops[] = {
     {"ls", ls},
     {"cd", cd},
@@ -242,6 +262,7 @@ OP ops[] = {
     {"rm", rm},
     {"link", link},
     {"mv", mv},
+    {"cp", cp},
     {"unknown", nullptr}
 };
 
diff --git a/fs/vfs.h b/fs/vfs.h
index 6a44ba3..977cb91 100644
--- a/fs/vfs.h
+++ b/fs/vfs.h
@@ -64,9 +64,9 @@ namespace VFS
         virtual void load_children()=0;
 
         // 在当前目录项创建文件夹
-        virtual void mkdir(const std::string& new_name)=0;
+        virtual VFS::DEntry* mkdir(const std::string& new_name)=0;
         // 在当前目录下创建空文件
-        virtual void create(const std::string& new_name)=0;
+        virtual VFS::DEntry* create(const std::string& new_name)=0;
         // 在当前目录下删除子项目，修改自己与子文件夹的引用关系
         virtual void unlink(DEntry*)=0;
         // 删除自己，释放空间，会由ulink(DEntry*)调用
@@ -76,11 +76,13 @@ namespace VFS
         // 判断一个目录是否为空
         virtual bool empty()=0; 
         // 在另一个目录项中创建自己的硬链接
-        virtual void link(DEntry *dir, const std::string& s="")=0;
+        virtual VFS::DEntry *link(DEntry *dir, const std::string& s="")=0;
         // 把自己移动到另一个目录中
-        virtual void move(DEntry *dir, const std::string& new_name="")=0;
+        virtual VFS::DEntry *move(DEntry *dir, const std::string& new_name="")=0;
         // 打开文件
         File *open();
+        // 把自己复制到另一个文件夹中，新文件夹中文件的Entry
+        virtual VFS::DEntry *copy(DEntry *dir, const std::string& new_name="")=0;
 
         File *open(const std::string& name);
         DEntry* get_child(const std::string& name);