diff --git a/fs/hmfs/Makefile b/fs/hmfs/Makefile
new file mode 100644
index 00000000..11542ca4
--- /dev/null
+++ b/fs/hmfs/Makefile
@@ -0,0 +1,20 @@
+ccflags-y += -DCONFIG_HMFS_DEBUG
+ccflags-y += -DCONFIG_HMFS_DEBUG_GC
+ccflags-y += -DCONFIG_HMFS_XATTR
+#ccflags-y += -DCONFIG_HMFS_FAST_READ
+ccflags-y += -DCONFIG_HMFS_ACL
+ccflags-y += -DCONFIG_HMFS_DEBUG_RW_LOCK
+
+obj-m += hmfs.o
+
+hmfs-objs := super.o node.o inode.o checkpoint.o file.o data.o namei.o segment.o hash.o dir.o symlink.o gc.o recovery.o
+
+hmfs-objs += debug.o
+hmfs-objs += xattr.o
+hmfs-objs += util.o
+hmfs-objs += acl.o
+
+all:
+	make -C /lib/modules/`uname -r`/build M=`pwd` modules
+clean:
+	make -C /lib/modules/`uname -r`/build M=`pwd` clean
diff --git a/fs/hmfs/build.sh b/fs/hmfs/build.sh
new file mode 100755
index 00000000..ea169ef6
--- /dev/null
+++ b/fs/hmfs/build.sh
@@ -0,0 +1,11 @@
+#!/bin/bash
+
+if [ "$1" == "hmfs" ] 
+    then
+    insmod ./hmfs.ko 
+    sudo mount -t hmfs -o physaddr=0x4B000000,init=100M none ~/mount_hmfs/
+elif [ "$1" == "nohmfs" ] 
+    then
+    umount ~/mount_hmfs
+    rmmod hmfs
+fi
\ No newline at end of file
diff --git a/fs/hmfs/checkpoint.c b/fs/hmfs/checkpoint.c
index 3a6a0cf4..54838fe1 100644
--- a/fs/hmfs/checkpoint.c
+++ b/fs/hmfs/checkpoint.c
@@ -624,8 +624,8 @@ static int flush_orphan_inodes(struct hmfs_sb_info *sbi, block_t *orphan_addrs)
 			orphan_addrs[i++] = orphan_addr;
 			orphan_block = ADDR(sbi, orphan_addr);
 			/* Reseverd for checkpoint address */
-			orphan_block = (__le32 *)JUMP(orphan_block, sizeof(__le64));
 			end = (__le32 *)JUMP(orphan_block, HMFS_PAGE_SIZE);
+			orphan_block = (__le32 *)JUMP(orphan_block, sizeof(__le64));
 		}
 		*orphan_block = cpu_to_le32(entry->ino);
 		orphan_block++;
diff --git a/fs/hmfs/debug.c b/fs/hmfs/debug.c
index f85e286c..c56fd5ae 100644
--- a/fs/hmfs/debug.c
+++ b/fs/hmfs/debug.c
@@ -92,6 +92,8 @@ static int stat_show(struct seq_file *s, void *v)
 	seq_printf(s, "main area range:%lu - %lu\n",
 		   (unsigned long)si->sbi->main_addr_start,
 		   (unsigned long)si->sbi->main_addr_end);
+	seq_printf(s, "GC Logs Segment Number:%lu\n", GET_SEGNO(si->sbi, 
+			L_ADDR(si->sbi, si->sbi->gc_logs)));
 	seq_printf(s, "max file size:%luk %luM %luG\n",
 		   max_file_size / 1024, max_file_size / 1024 / 1024,
 		   max_file_size / 1024 / 1024 / 1024);
@@ -129,13 +131,25 @@ static int stat_show(struct seq_file *s, void *v)
 	return 0;
 }
 
+static char get_segment_state(struct hmfs_sb_info *sbi, seg_t i)
+{
+	struct free_segmap_info *free_i = FREE_I(sbi);
+	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
+
+	if (test_bit(i, dirty_i->dirty_segmap))
+		return '*';
+	else if (!test_bit(i, free_i->free_segmap))
+		return '#';
+	else if (test_bit(i, free_i->prefree_segmap)) 
+		return '^';
+	else return '@';
+}
+
 static int vb_show(struct seq_file *s, void *v)
 {
 	struct hmfs_stat_info *si = s->private;
 	struct hmfs_sb_info *sbi = si->sbi;
 	int i, j;
-	struct free_segmap_info *free_i = FREE_I(sbi);
-	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 
 	seq_printf(s, "# free\n* dirty\n^ prefree\n@ in use\n");
 	for (i = 0, j = 0; i < TOTAL_SEGS(sbi); i++, j++) {
@@ -143,21 +157,13 @@ static int vb_show(struct seq_file *s, void *v)
 			seq_printf(s, "\n");
 			j = 0;
 		}
-		if (test_bit(i, dirty_i->dirty_segmap))
-			seq_printf(s, "*");
-		else if (!test_bit(i, free_i->free_segmap))
-			seq_printf(s, "#");
-		else if (test_bit(i, free_i->prefree_segmap)) 
-			seq_printf(s, "^");
-		else seq_printf(s, "@");
+		seq_printf(s, "%c", get_segment_state(sbi, i));	
 	}
 
 	seq_printf(s, "\n");
 	for (i = 0; i < TOTAL_SEGS(sbi); i++) {
-		seq_printf(s, "%d:%d %lu\n", i, get_valid_blocks(sbi, i), 
-				get_seg_vblocks_in_summary(sbi, i));
-		hmfs_bug_on(sbi, get_valid_blocks(sbi, i) != 
-				get_seg_vblocks_in_summary(sbi, i));
+		seq_printf(s, "%d(%c):%d %lu\n", i, get_segment_state(sbi, i), 
+				get_valid_blocks(sbi, i), get_seg_vblocks_in_summary(sbi, i));
 	}
 
 	return 0;
@@ -206,7 +212,7 @@ static ssize_t info_read(struct file *file, char __user * buffer, size_t count,
 	if (count + *ppos > si->buf_size)
 		count = si->buf_size - *ppos;
 
-	if (copy_to_user(buffer, si->buffer, count)) {
+	if (copy_to_user(buffer, si->buffer + *ppos, count)) {
 		return -EFAULT;
 	}
 
@@ -497,8 +503,7 @@ static size_t print_ssa_one(struct hmfs_sb_info *sbi, block_t blk_addr)
 	}
 
 	sum_entry = get_summary_by_addr(sbi, blk_addr);
-
-	len += hmfs_print(si, 1, "-- [%016x] --\n", blk_addr >> HMFS_PAGE_SIZE_BITS);
+	len += hmfs_print(si, 1, "-- [%d %d] --\n", GET_SEGNO(sbi, blk_addr), GET_SEG_OFS(sbi, blk_addr));
 	len += hmfs_print(si, 1, "  nid: %u\n", le32_to_cpu(sum_entry->nid));
 	len += hmfs_print(si, 1, "  start_version: %u\n",
 			   le32_to_cpu(sum_entry->start_version));
diff --git a/fs/hmfs/dir.c b/fs/hmfs/dir.c
index 0fa2399d..672d8d93 100644
--- a/fs/hmfs/dir.c
+++ b/fs/hmfs/dir.c
@@ -692,7 +692,6 @@ void hmfs_delete_entry(struct hmfs_dir_entry *dentry,
 		/* Inline directory should never reach here */
 		hmfs_bug_on(sbi, is_inline_inode(dir));
 
-		hmfs_dbg("%d\n",bidx);
 		dir_i_size = i_size_read(dir);
 		truncate_hole(dir, bidx, bidx + 1);
 		if (dir_i_size >> HMFS_PAGE_SIZE_BITS == bidx + 1) {
diff --git a/fs/hmfs/file.c b/fs/hmfs/file.c
index 71eeb991..92e13de0 100644
--- a/fs/hmfs/file.c
+++ b/fs/hmfs/file.c
@@ -750,6 +750,7 @@ int truncate_data_blocks_range(struct dnode_of_data *dn, int count)
 			new_node->i.i_addr[ofs] = NULL_ADDR;
 	}
 
+
 	if (nr_free) {
 		dec_valid_block_count(sbi, dn->inode, nr_free);
 		mark_inode_dirty(dn->inode);
diff --git a/fs/hmfs/gc.c b/fs/hmfs/gc.c
index ee2ad3c9..3845bfc2 100644
--- a/fs/hmfs/gc.c
+++ b/fs/hmfs/gc.c
@@ -462,9 +462,8 @@ static void move_orphan_block(struct hmfs_sb_info *sbi, seg_t src_segno,
 	block_t cp_addr;
 	prepare_move_argument(&args, sbi, src_segno, src_off, src_sum,
 			TYPE_NODE);
-	hmfs_cp = args.cp_i->cp;
-	cp_addr = le64_to_cpu(hmfs_cp->orphan_addrs[get_summary_offset(src_sum)]);
-	hmfs_bug_on(sbi, cp_addr != L_ADDR(args.src));
+	cp_addr = le64_to_cpu(*((__le64 *)args.src));
+	hmfs_cp = ADDR(sbi, cp_addr);
 	hmfs_cp->orphan_addrs[get_summary_offset(src_sum)] = 
 			cpu_to_le64(args.dest_addr);
 
@@ -514,7 +513,6 @@ static void garbage_collect(struct hmfs_sb_info *sbi, seg_t segno)
 	nid_t nid;
 	struct hmfs_summary_block *sum_blk;
 	struct hmfs_summary *sum;
-	int tmp=0;
 
 	none_valid = !get_seg_entry(sbi, segno)->valid_blocks;
 
@@ -524,9 +522,10 @@ static void garbage_collect(struct hmfs_sb_info *sbi, seg_t segno)
 	sum_blk = get_summary_block(sbi, segno);
 	sum = sum_blk->entries;
 
+	//#ERROR: inconsistent of segno->valid_blocks
 	for (off = 0; off < HMFS_PAGE_PER_SEG; ++off, sum++) {
 		is_current  = get_summary_start_version(sum) == cm_i->new_version;
-		
+
 		/*
 		 * We ignore two kinds of blocks:
 		 * 	- invalid blocks in older version
@@ -537,12 +536,12 @@ static void garbage_collect(struct hmfs_sb_info *sbi, seg_t segno)
 
 		if (is_current) {
 			nid = get_summary_nid(sum);
-			if (IS_ERR(get_node(sbi, nid)))
+			if (IS_ERR(get_node(sbi, nid))){
 				continue;
+			}
 		}
 
 		hmfs_bug_on(sbi, get_summary_valid_bit(sum) && is_current);
-
 		switch (get_summary_type(sum)) {
 		case SUM_TYPE_DATA:
 			move_data_block(sbi, segno, off, sum);
@@ -574,7 +573,6 @@ static void garbage_collect(struct hmfs_sb_info *sbi, seg_t segno)
 		}
 	}
 
-	hmfs_dbg("tmp:%d\n",tmp);
 recycle:
 	recycle_segment(sbi, segno, none_valid);
 }
diff --git a/fs/hmfs/namei.c b/fs/hmfs/namei.c
index 14cd0dfa..fcfef6ba 100644
--- a/fs/hmfs/namei.c
+++ b/fs/hmfs/namei.c
@@ -238,7 +238,7 @@ static int hmfs_unlink(struct inode *dir, struct dentry *dentry)
 	inode_write_unlock(dir);
 
 	mutex_unlock_op(sbi, ilock);
-	mark_inode_dirty(inode);
+	mark_inode_dirty(dir);
 fail:
 	return err;
 }
diff --git a/fs/hmfs/node.c b/fs/hmfs/node.c
index 6327a4a4..e93b7fad 100644
--- a/fs/hmfs/node.c
+++ b/fs/hmfs/node.c
@@ -1206,6 +1206,7 @@ static int __flush_nat_journals(struct hmfs_checkpoint *hmfs_cp,
 
 	nat_journal = &hmfs_cp->nat_journals[*journal_pos];
 
+	*journal_pos = *journal_pos + nr_dirty_nat;
 	while (nr_dirty_nat > 0) {
 		entry = list_entry(entry->list.prev, struct nat_entry, list);
 		nat_journal->nid = cpu_to_le32(entry->ni.nid);
@@ -1215,7 +1216,6 @@ static int __flush_nat_journals(struct hmfs_checkpoint *hmfs_cp,
 		nat_journal++;
 		entry->ni.flag |= NAT_FLAG_JOURNAL;
 	}
-	*journal_pos = *journal_pos + nr_dirty_nat;
 	return 0;
 }
 
@@ -1482,6 +1482,7 @@ static void __mark_block_valid(struct hmfs_sb_info *sbi,
 		return;
 	}
 
+	set_summary_valid_bit(raw_summary);
 	//leaf, alloc & copy nat entry block 
 	if (!height) {
 		hmfs_bug_on(sbi, get_summary_type(raw_summary) != SUM_TYPE_NATD);
diff --git a/fs/hmfs/segment.c b/fs/hmfs/segment.c
index 46218ec1..bddcf4cf 100644
--- a/fs/hmfs/segment.c
+++ b/fs/hmfs/segment.c
@@ -6,6 +6,9 @@
  * it fall into space where we have actually writen data
  * into. It's different from valid bits in summary entry
  */
+ /*
+ * Hi,everybody,this is a test from caihui
+ */
 bool is_valid_address(struct hmfs_sb_info *sbi, block_t addr)
 {
 	seg_t segno = GET_SEGNO(sbi, addr);
@@ -183,7 +186,7 @@ int get_new_segment(struct hmfs_sb_info *sbi, seg_t *newseg)
 	hmfs_bug_on(sbi, test_bit(segno, free_i->free_segmap));
 	__set_inuse(sbi, segno);
 	*newseg = segno;
-	/* Need to clear SSA */
+	/* TODO: Need not to clear SSA */
 	ssa = get_summary_block(sbi, segno);
 	memset_nt(ssa, 0, HMFS_SUMMARY_BLOCK_SIZE);
 unlock:
@@ -479,6 +482,7 @@ void free_prefree_segments(struct hmfs_sb_info *sbi)
 	int total_segs = TOTAL_SEGS(sbi);
 	unsigned long *bitmap = free_i->prefree_segmap;
 	seg_t segno = 0;
+	void *ssa;
 
 	lock_write_segmap(free_i);
 	while (1) {
@@ -489,6 +493,8 @@ void free_prefree_segments(struct hmfs_sb_info *sbi)
 		if (test_and_clear_bit(segno, free_i->free_segmap)) {
 			free_i->free_segments++;
 		}
+		ssa = get_summary_block(sbi, segno);
+		memset_nt(ssa, 0, HMFS_SUMMARY_BLOCK_SIZE);
 		segno++;
 	}
 	unlock_write_segmap(free_i);
diff --git a/fs/hmfs/test/create.sh b/fs/hmfs/test/create.sh
new file mode 100755
index 00000000..84d00e16
--- /dev/null
+++ b/fs/hmfs/test/create.sh
@@ -0,0 +1,11 @@
+#!/bin/bash
+
+num_file=2048
+
+#create testing files, they will be orphan files later
+for ((i=0; i<$num_file; i++)); do
+    touch ~/mount_hmfs/orphan_$i.txt
+    echo "this is a test file" > ~/mount_hmfs/orphan_$i.txt
+done
+
+echo "$num_file files created..."
\ No newline at end of file
diff --git a/fs/hmfs/test/delete.sh b/fs/hmfs/test/delete.sh
new file mode 100755
index 00000000..2981095f
--- /dev/null
+++ b/fs/hmfs/test/delete.sh
@@ -0,0 +1,15 @@
+#!/bin/bash
+
+num_file=2048
+for ((i=0; i<$num_file; i++)); do
+    #remove the file will create an orhan file
+    rm ~/mount_hmfs/orphan_$i.txt
+done
+
+echo "$num_file files deleted..."
+
+#check the cmi info
+. ./info.sh "cmi"
+
+#sync the file to enforce doing checkpoint
+sync
diff --git a/fs/hmfs/test/hold_file_open.py b/fs/hmfs/test/hold_file_open.py
new file mode 100644
index 00000000..43401372
--- /dev/null
+++ b/fs/hmfs/test/hold_file_open.py
@@ -0,0 +1,14 @@
+#!/usr/bin/python3
+from os.path import expanduser
+
+
+home = expanduser('~')
+file_list = []
+for i in range(2048):
+    with open(home + "/mount_hmfs/orphan_{:d}.txt".format(i), 'w') as file:
+        file_list.append(file)
+        file.write("ssssssssssssssssssss")
+
+#hold files
+while True:
+    pass
diff --git a/fs/hmfs/test/info.sh b/fs/hmfs/test/info.sh
new file mode 100755
index 00000000..6d24a2ed
--- /dev/null
+++ b/fs/hmfs/test/info.sh
@@ -0,0 +1,4 @@
+#!/bin/bash
+
+hmfs_debug_dir=/sys/kernel/debug/hmfs/1258291200/info
+echo "$1" > ${hmfs_debug_dir} & cat ${hmfs_debug_dir}
\ No newline at end of file
diff --git a/fs/hmfs/test/mount_f2fs.sh b/fs/hmfs/test/mount_f2fs.sh
new file mode 100755
index 00000000..f1d13e91
--- /dev/null
+++ b/fs/hmfs/test/mount_f2fs.sh
@@ -0,0 +1,10 @@
+#!/bin/bash
+
+# create a 100M file
+dd if=/dev/zero of=/opt/dev0-backstore bs=1M count=100
+
+# create the loopback block device
+mknod /dev/fake-dev0 b 7 200
+
+losetup /dev/fake-dev0 /opt/dev0-backstore
+mount -t f2fs /dev/fake-dev0 ~/mount_f2fs/
\ No newline at end of file
diff --git a/fs/hmfs/test/open.c b/fs/hmfs/test/open.c
new file mode 100644
index 00000000..d2cd40e5
--- /dev/null
+++ b/fs/hmfs/test/open.c
@@ -0,0 +1,17 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+int main(void)
+{
+    FILE* fps[2048];
+    char filename[100];
+    for (int i = 0; i < 2048; i++) {
+        sprintf(filename, "/home/wgtdkp/mount_hmfs/orphan_%d.txt", i);
+        printf("%s\n", filename);
+        fps[i] = fopen(filename, "r");
+        if (!fps[i])
+            printf("error!\n");
+    }
+    while (1) {}
+    return 0;
+}
\ No newline at end of file
diff --git a/fs/hmfs/test/orphan_test.sh b/fs/hmfs/test/orphan_test.sh
new file mode 100755
index 00000000..e4105941
--- /dev/null
+++ b/fs/hmfs/test/orphan_test.sh
@@ -0,0 +1,31 @@
+#!/bin/bash
+
+num_file=2048
+cd ~/mount_hmfs/
+
+#create testing files, they will be orphan files later
+for ((i=0; i<$num_file; i++)); do
+    touch orphan_$i.txt
+    echo "this is a test file" > orphan_$i.txt
+done
+
+echo ${num_file} "file created"
+
+#python3 $HOME/hmfs/fs/hmfs/test/hold_file_open.py &
+
+#for ((i=0; i<$num_file; i++)); do
+    #remove the file will create an orhan file
+#    rm orphan_$i.txt
+#done
+
+#cd $HOME/hmfs/fs/hmfs/test/
+#check the cmi info
+#. ./info.sh "cmi"
+
+#sync the file to enforce doing checkpoint
+#sync
+
+
+
+
+
diff --git a/fs/hmfs/test/reproduce.sh b/fs/hmfs/test/reproduce.sh
new file mode 100755
index 00000000..db99fe55
--- /dev/null
+++ b/fs/hmfs/test/reproduce.sh
@@ -0,0 +1,10 @@
+#!/bin/bash
+
+cd $HOME/hmfs/fs/hmfs/test/
+
+. ./create.sh
+. ./delete.sh
+. ./create.sh
+. ./delete.sh
+. ./create.sh
+#. ./delete.sh