diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs
index b09108811ff1..84c606fb3ca4 100644
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -124,3 +124,9 @@ Date:		May 2016
 Contact:	"Sheng Yong" <shengyong1@huawei.com>
 Description:
 		 Controls the injection type.
+
+What:		/sys/fs/f2fs/<disk>/reserved_blocks
+Date:		June 2017
+Contact:	"Chao Yu" <yuchao0@huawei.com>
+Description:
+		 Controls current reserved blocks in system.
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index c27a6264d9bf..e15d55ccc4bc 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -966,6 +966,8 @@ struct f2fs_sb_info {
 	block_t total_valid_block_count;	/* # of valid blocks */
 	block_t discard_blks;			/* discard command candidats */
 	block_t last_valid_block_count;		/* for recovery */
+	block_t reserved_blocks;		/* configurable reserved blocks */
+
 	u32 s_next_generation;			/* for NFS support */
 
 	/* # of pages, see count_type */
@@ -1376,6 +1378,7 @@ static inline bool inc_valid_block_count(struct f2fs_sb_info *sbi,
 				 struct inode *inode, blkcnt_t *count)
 {
 	blkcnt_t diff;
+	block_t avail_user_block_count;
 
 #ifdef CONFIG_F2FS_FAULT_INJECTION
 	if (time_to_inject(sbi, FAULT_BLOCK)) {
@@ -1391,10 +1394,11 @@ static inline bool inc_valid_block_count(struct f2fs_sb_info *sbi,
 
 	spin_lock(&sbi->stat_lock);
 	sbi->total_valid_block_count += (block_t)(*count);
-	if (unlikely(sbi->total_valid_block_count > sbi->user_block_count)) {
-		diff = sbi->total_valid_block_count - sbi->user_block_count;
+	avail_user_block_count = sbi->user_block_count - sbi->reserved_blocks;
+	if (unlikely(sbi->total_valid_block_count > avail_user_block_count)) {
+		diff = sbi->total_valid_block_count - avail_user_block_count;
 		*count -= diff;
-		sbi->total_valid_block_count = sbi->user_block_count;
+		sbi->total_valid_block_count = avail_user_block_count;
 		if (!*count) {
 			spin_unlock(&sbi->stat_lock);
 			percpu_counter_sub(&sbi->alloc_valid_block_count, diff);
@@ -1556,7 +1560,8 @@ static inline bool inc_valid_node_count(struct f2fs_sb_info *sbi,
 	spin_lock(&sbi->stat_lock);
 
 	valid_block_count = sbi->total_valid_block_count + 1;
-	if (unlikely(valid_block_count > sbi->user_block_count)) {
+	if (unlikely(valid_block_count + sbi->reserved_blocks >
+						sbi->user_block_count)) {
 		spin_unlock(&sbi->stat_lock);
 		return false;
 	}
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 3da6fb276f8b..c45bac6f1795 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -691,7 +691,8 @@ static int f2fs_statfs(struct dentry *dentry, struct kstatfs *buf)
 
 	buf->f_blocks = total_count - start_count;
 	buf->f_bfree = user_block_count - valid_user_blocks(sbi) + ovp_count;
-	buf->f_bavail = user_block_count - valid_user_blocks(sbi);
+	buf->f_bavail = user_block_count - valid_user_blocks(sbi) -
+						sbi->reserved_blocks;
 
 	avail_node_count = sbi->total_node_count - F2FS_RESERVED_NODE_NUM;
 
@@ -1768,6 +1769,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 	sbi->total_valid_block_count =
 				le64_to_cpu(sbi->ckpt->valid_block_count);
 	sbi->last_valid_block_count = sbi->total_valid_block_count;
+	sbi->reserved_blocks = 0;
 
 	for (i = 0; i < NR_INODE_TYPE; i++) {
 		INIT_LIST_HEAD(&sbi->inode_list[i]);
diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index 714a3e47bbe8..9adc202fcd6f 100644
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -30,6 +30,7 @@ enum {
 	FAULT_INFO_RATE,	/* struct f2fs_fault_info */
 	FAULT_INFO_TYPE,	/* struct f2fs_fault_info */
 #endif
+	RESERVED_BLOCKS,
 };
 
 struct f2fs_attr {
@@ -51,7 +52,7 @@ static unsigned char *__struct_ptr(struct f2fs_sb_info *sbi, int struct_type)
 		return (unsigned char *)SM_I(sbi)->dcc_info;
 	else if (struct_type == NM_INFO)
 		return (unsigned char *)NM_I(sbi);
-	else if (struct_type == F2FS_SBI)
+	else if (struct_type == F2FS_SBI || struct_type == RESERVED_BLOCKS)
 		return (unsigned char *)sbi;
 #ifdef CONFIG_F2FS_FAULT_INJECTION
 	else if (struct_type == FAULT_INFO_RATE ||
@@ -111,6 +112,17 @@ static ssize_t f2fs_sbi_store(struct f2fs_attr *a,
 	if (a->struct_type == FAULT_INFO_TYPE && t >= (1 << FAULT_MAX))
 		return -EINVAL;
 #endif
+	if (a->struct_type == RESERVED_BLOCKS) {
+		spin_lock(&sbi->stat_lock);
+		if ((unsigned long)sbi->total_valid_block_count + t >
+				(unsigned long)sbi->user_block_count) {
+			spin_unlock(&sbi->stat_lock);
+			return -EINVAL;
+		}
+		*ui = t;
+		spin_unlock(&sbi->stat_lock);
+		return count;
+	}
 	*ui = t;
 	return count;
 }
@@ -165,6 +177,7 @@ F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_no_gc_sleep_time, no_gc_sleep_time);
 F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_idle, gc_idle);
 F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, reclaim_segments, rec_prefree_segments);
 F2FS_RW_ATTR(DCC_INFO, discard_cmd_control, max_small_discards, max_discards);
+F2FS_RW_ATTR(RESERVED_BLOCKS, f2fs_sb_info, reserved_blocks, reserved_blocks);
 F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, batched_trim_sections, trim_sections);
 F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, ipu_policy, ipu_policy);
 F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, min_ipu_util, min_ipu_util);
@@ -208,6 +221,7 @@ static struct attribute *f2fs_attrs[] = {
 	ATTR_LIST(inject_type),
 #endif
 	ATTR_LIST(lifetime_write_kbytes),
+	ATTR_LIST(reserved_blocks),
 	NULL,
 };