diff --git a/fs/ext4/defrag.c b/fs/ext4/defrag.c
index a2b17c5..bdfbb68 100644
--- a/fs/ext4/defrag.c
+++ b/fs/ext4/defrag.c
@@ -622,6 +622,10 @@ int ext4_defrag_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,

 		err = ext4_defrag_move_victim(filp, &ext_info);

+	} else if (cmd == EXT4_IOC_BLOCK_RELEASE) {
+		down_write(&EXT4_I(inode)->i_data_sem);
+		ext4_discard_reservation(inode);
+		up_write(&EXT4_I(inode)->i_data_sem);
 	} else if (cmd == EXT4_IOC_DEFRAG) {
 		struct ext4_ext_defrag_data defrag;
 		struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 4e54eb4..6ad86f9 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -314,6 +314,7 @@ struct ext4_new_group_data {
 #define EXT4_IOC_FIEMAP_INO		_IOW('f', 19, struct fiemap_ino)
 #define EXT4_IOC_RESERVE_BLOCK		_IOW('f', 20, struct ext4_extents_info)
 #define EXT4_IOC_MOVE_VICTIM		_IOW('f', 21, struct ext4_extents_info)
+#define EXT4_IOC_BLOCK_RELEASE		_IO('f', 22)

 /*
  * ioctl commands in 32 bit emulation
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index a596785..329847f 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -262,7 +262,8 @@ setversion_out:
 	case EXT4_IOC_FREE_BLOCKS_INFO:
 	case EXT4_IOC_FIEMAP_INO:
 	case EXT4_IOC_RESERVE_BLOCK:
-	case EXT4_IOC_MOVE_VICTIM: {
+	case EXT4_IOC_MOVE_VICTIM:
+	case EXT4_IOC_BLOCK_RELEASE: {
 		return ext4_defrag_ioctl(inode, filp, cmd, arg);
 	}
 	case EXT4_IOC_GROUP_ADD: {