diff --git a/delog/common.cpp b/delog/common.cpp
index e7bdc6d..28d7afd 100644
--- a/delog/common.cpp
+++ b/delog/common.cpp
@@ -2,7 +2,7 @@
 
 
 std::vector<std::string> split(const std::string& s, char sp) {
-    int i = 0, l = 0;
+    size_t i = 0, l = 0;
     std::vector<std::string> res;
     while (i < s.size()) {
         if (s[i] == sp) {
diff --git a/delog/delog.cpp b/delog/delog.cpp
index 7e6f17b..ff0d351 100644
--- a/delog/delog.cpp
+++ b/delog/delog.cpp
@@ -253,7 +253,7 @@ _print_debug_CON:
         default:
             fprintf(stderr, "Unknown fmt %c\n", fmt[0]);
     }
-_print_debug_END:
+// _print_debug_END:
     return ;
 }
 
@@ -323,7 +323,7 @@ _I print_bin(_s s, _I size, _u8 *p, _I len) {
         if ((i & _BITS_MASK(LINEBSIZE)) == 0) {
             last_i = LINENUM;
             if (j > 0 && j < LINENUM + 1) {
-                for (int t = 0; t < LINENUM - j; t++)
+                for (_u32 t = 0; t < LINENUM - j; t++)
                     fmt_dot(s, n);
                 last_i = j;
             } 
@@ -348,7 +348,7 @@ _I print_bin(_s s, _I size, _u8 *p, _I len) {
     if (len) {
         last_i = LINENUM;
         if (j > 0 && j < LINENUM + 1) {
-            for (int t = 0; t < LINENUM - j; t++)
+            for (_u32 t = 0; t < LINENUM - j; t++)
                 fmt_dot(s, n);
             last_i = j;
         }
diff --git a/fs/ext2/ext2_dentry.cpp b/fs/ext2/ext2_dentry.cpp
index 70a1dde..c02403e 100644
--- a/fs/ext2/ext2_dentry.cpp
+++ b/fs/ext2/ext2_dentry.cpp
@@ -49,7 +49,7 @@ void EXT2_DEntry::load_children() {
         dev->read(buf, data_block_pos, ext2_fs->block_size);
         // _sa(buf.data, ext2_fs->block_size);
         _u32 s_pos = 0;
-        _u32 next_length = 12;
+        // _u32 next_length = 12;
         while (all_length < ext2_inode->size) {
             // _sa(buf.data + s_pos, 20);
             memmove(temp_str, buf.data + s_pos, sizeof(DirEntry));
@@ -397,5 +397,9 @@ VFS::DEntry *EXT2_DEntry::follow() {
 
 EXT2_DEntry::~EXT2_DEntry() {
     delete inode;
+    for (auto x: children) {
+        if (x->name != ".." && x->name != ".")
+            delete x;
+    }
 }
 
diff --git a/fs/ext2/ext2_file.cpp b/fs/ext2/ext2_file.cpp
index b73eb4b..3f1e516 100644
--- a/fs/ext2/ext2_file.cpp
+++ b/fs/ext2/ext2_file.cpp
@@ -66,7 +66,7 @@ int EXT2_File::read(char *buf, int len) {
     ext2_fs->dev->read(buff, pos_in_fs, block_size);  // 从第一个块读入数据，每次都读出一整块
     memcpy(buf, buff.data + byte_in_block, std::min((_u32)len, block_size - byte_in_block));
     read_len = std::min((_u32)len, block_size - byte_in_block);
-    while (read_len < len && pos + read_len < size) {
+    while (read_len < (_u32)len && pos + read_len < (_u32)size) {
         it++;  // 指向下一个块
         block_n = *it;  // 下一个块号
         pos_in_fs = ext2_fs->block_to_pos(block_n);  // 下一个块的位置
@@ -95,7 +95,7 @@ int EXT2_File::write(const char *buf, int len) {
     memcpy(buff.data, buf, this_write_len);
     ext2_fs->dev->write(buff, pos_in_fs + byte_in_block, this_write_len);  // 向第一个块写数据
     write_len = this_write_len;
-    while (write_len < len) {
+    while (write_len < (_u32)len) {
         it++;  // 指向下一个块
         block_n = *it;  // 下一个块号，其实这里可以自动分配空间，不用resize
         pos_in_fs = ext2_fs->block_to_pos(block_n);  // 下一个块的位置
diff --git a/fs/ext2/ext2_fs.cpp b/fs/ext2/ext2_fs.cpp
index 5621885..31f3fc7 100644
--- a/fs/ext2/ext2_fs.cpp
+++ b/fs/ext2/ext2_fs.cpp
@@ -99,7 +99,7 @@ void EXT2_FS::mount() {
     // dev->seek(block_size + 1024);  // 指向GDT
     _u32 read_pos = block_size + 1024;
     group_cnt = sb->inodes_count / sb->inodes_per_group;
-    for (int i = 0; i < group_cnt; i++) {
+    for (_u32 i = 0; i < group_cnt; i++) {
         GroupDescriptor* gtp = new GroupDescriptor();
         dev->read(sb_buf, read_pos, sizeof(GroupDescriptor));
         memmove(gtp, sb_buf.data, sizeof(GroupDescriptor));
@@ -118,7 +118,7 @@ void EXT2_FS::mount() {
     // dev->read(sb_buf, sizeof(Inode));
     // Inode* root_inode = new Inode();
     // memmove(root_inode, sb_buf.data, sizeof(Inode));
-    _u32 root_inode_pos = gdt_list.front()->get_gd()->inode_table;
+    // _u32 root_inode_pos = gdt_list.front()->get_gd()->inode_table;
     EXT2_DEntry* ext2_entry = new EXT2_DEntry(this, nullptr, 2, VFS::Directory, "/");
     root = ext2_entry;
     // ext2_entry->inflate();
@@ -183,7 +183,7 @@ void EXT2_FS::write_super() {
     _u32 super_pos = 1;  // super block 
     MM::Buf buf(sizeof(SuperBlock));
     memcpy(buf.data, sb, sizeof(SuperBlock));
-    for (EXT2_GD *x: gdt_list) {
+    for (size_t i = 0; i < gdt_list.size(); i++) {
         dev->write(buf, block_to_pos(super_pos), sizeof(SuperBlock));
         super_pos += sb->blocks_per_group;
     }
@@ -201,7 +201,7 @@ void EXT2_FS::write_gdt() {
         x->write_inode_bitmap();
         x->write_block_bitmap();
     }
-    for (EXT2_GD *x: gdt_list) {
+    for (size_t i = 0; i < gdt_list.size(); i++) {
         dev->write(buf, block_to_pos(super_pos), sizeof(GroupDescriptor));
         super_pos += sb->blocks_per_group;
     }
@@ -222,4 +222,5 @@ EXT2_FS::~EXT2_FS() {
         delete x;
     }
     delete sb;
+    delete root;
 }
diff --git a/fs/ext2/ext2_group_descriptor.cpp b/fs/ext2/ext2_group_descriptor.cpp
index 016c8d2..05fe8c2 100644
--- a/fs/ext2/ext2_group_descriptor.cpp
+++ b/fs/ext2/ext2_group_descriptor.cpp
@@ -49,7 +49,7 @@ _u32 EXT2_GD::alloc_inode() {
     if (gd->free_inodes_count == 0)
         return 0;
     get_inode_bitmap();
-    for (int i = 0; i < fs->block_size; i++) {
+    for (_u32 i = 0; i < fs->block_size; i++) {
         if (inode_bitmap[i] != (_u8)0xff) {
             int t = lowest_0(inode_bitmap[i]);
             _set_bit(inode_bitmap[i], t);
@@ -65,7 +65,7 @@ _u32 EXT2_GD::alloc_block() {
     if (gd->free_blocks_count == 0)
         return 0;
     get_block_bitmap();
-    for (int i = 0; i < fs->block_size; i++) {
+    for (_u32 i = 0; i < fs->block_size; i++) {
         if (block_bitmap[i] != (_u8)0xff) {
             int t = lowest_0(block_bitmap[i]);
             _set_bit(block_bitmap[i], t);
diff --git a/fs/ext2/ext2_inode.cpp b/fs/ext2/ext2_inode.cpp
index 14e9831..4e68b53 100644
--- a/fs/ext2/ext2_inode.cpp
+++ b/fs/ext2/ext2_inode.cpp
@@ -26,7 +26,7 @@ void EXT2_Inode::print() {
     cerr << "目录访问控制列表 " << i->dir_acl << endl;
     cerr << "片地址 " << i->faddr << endl;
     cerr << "数据块指针 ";
-    for (int j = 0; j < min(blocks, (_u32)15); j++)
+    for (_u32 j = 0; j < min(blocks, (_u32)15); j++)
         cerr << i->block[j] << " ";
     cerr << endl;
 }
@@ -317,7 +317,7 @@ EXT2_Inode::iterator::operator==(const iterator& ano) const {
     _error(inode != ano.inode);
     if (ano.index_cnt != index_cnt || ano.level != level)
         return false;
-    for (_u32 i = 0; i < level; i++) {
+    for (int i = 0; i < level; i++) {
         if (indexs[i] != ano.indexs[i])
             return false;
     }
diff --git a/fs/test_fs.cpp b/fs/test_fs.cpp
index 05a1936..b798fe4 100644
--- a/fs/test_fs.cpp
+++ b/fs/test_fs.cpp
@@ -251,6 +251,7 @@ VFS::DEntry *mount(VFS::DEntry *cwd, const std::vector<std::string>& cmdd) {
     FS* new_fs = new EXT2::EXT2_FS(d);
     new_fs->mount();
     new_fs->root->load_children();
+    new_fs->root->parent = mnt_e->parent;
     // mnt_e->inode = new_fs->root->inode;
     // mnt_e->children = new_fs->root->children;
     new_fs->root->name = mnt_e->name;
@@ -259,6 +260,22 @@ VFS::DEntry *mount(VFS::DEntry *cwd, const std::vector<std::string>& cmdd) {
     return cwd;
 }
 
+VFS::DEntry *umount(VFS::DEntry *cwd, const std::vector<std::string>& cmdd) {
+    using namespace VFS;
+    NameI *dir = VFS::NameI::from_str(cmdd[cmdd.size() - 1]);
+    DEntry *mnt_e = cwd->get_child(dir);
+    if (mnt_e == nullptr) {
+        std::cout << "no such diectory " << cmdd[cmdd.size() - 1] << std::endl;
+        return cwd;
+    }
+    DEntry *t = mnt_e->parent;
+    t->children.clear();
+    t->load_children();
+    mnt_e->fs->dev->close();
+    delete mnt_e->fs;
+    return cwd;
+}
+
 OP ops[] = {
     {"ls", ls},
     {"cd", cd},
@@ -271,6 +288,7 @@ OP ops[] = {
     {"cp", cp},
     {"ln", symlink},
     {"mount", mount},
+    {"umount", umount},
     {"unknown", nullptr}
 };
 
diff --git a/fs/vfs.cpp b/fs/vfs.cpp
index 8e00b67..6c43bba 100644
--- a/fs/vfs.cpp
+++ b/fs/vfs.cpp
@@ -138,9 +138,6 @@ VFS::NameI *VFS::NameI::from_str(const std::string& path) {
     }
     _pos();
     return ans;
-error:
-    delete ans;
-    return nullptr;
 }
 
 _u8 VFS::mode_to_type(_u8 mode) {
diff --git a/fs/vfs.h b/fs/vfs.h
index ded27c1..2b21b29 100644
--- a/fs/vfs.h
+++ b/fs/vfs.h
@@ -98,6 +98,9 @@ namespace VFS
         DEntry *get_path(const NameI *namei, std::string* fname=nullptr);
 
         std::string printed_path();
+
+
+        virtual ~DEntry() {}
     };
 
     enum {
@@ -107,7 +110,7 @@ namespace VFS
 
     class FS {
     public:
-        Dev::BlockDevice* dev;  // 设备
+        Dev::BlockDevice* dev=nullptr;  // 设备
         // _u32 flag;  // 安装标志
         _u32 magic;  // 文件系统标志
 
@@ -142,11 +145,12 @@ namespace VFS
         _u8 sock;  // 如果文件是一个socket则为0
         int lock;  // 自旋锁
 
-        FS* fs;
+        FS* fs=nullptr;
     public:
-        Inode(FS* fs1):fs(fs1), dev(fs1->dev) {}
+        Inode(FS* fs1):dev(fs1->dev), fs(fs1) {}
         // 将Inode标记为脏，找时机写回设备        
         virtual void dirty()=0;
+        virtual ~Inode() {}
     };
 
 
@@ -164,6 +168,9 @@ namespace VFS
         virtual int read(char*, int size)=0;
         virtual int write(const char*, int size)=0;
         virtual void close();
+
+        virtual ~File() {}
+
     };
 
     _u8 mode_to_type(_u8 mode);
diff --git a/include/bits.h b/include/bits.h
index 567b2b8..2db56d7 100644
--- a/include/bits.h
+++ b/include/bits.h
@@ -12,7 +12,7 @@
 #define _lshf(a, n) ((a) >> (n))
 #define _Lclr(a, n) ((a) & (~(_BITS_MASK(n))))
 #define _Hclr(a, n) _rshf(_lshf(a, n), n)
-#define _LNclr(a, n) ((a & (_BITS_MASK(n))))
+#define _LNclr(a, n) (((a) & (_BITS_MASK(n))))
 
 #include "types.h"
 
diff --git a/makefile b/makefile
index 4ac346d..fbcd015 100644
--- a/makefile
+++ b/makefile
@@ -14,7 +14,9 @@ INC_FLAG = $(addprefix -I, $(INC_PATH))
 DEFINES = DEBUG
 DEF_FLAG = $(addprefix -D, $(DEFINES))
 
-CC_FLAG = $(INC_FLAG) $(DEF_FLAG)
+OTH_FLAG = -Werror -Wall
+
+CC_FLAG = $(INC_FLAG) $(DEF_FLAG) $(OTH_FLAG)
 
 # MAIN_NAME = config/test_config
 # OBJ_FILE= $(addsuffix .o, $(addprefix $(OBJ_PATH)/, $(SRC_NAME)))