diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index a0212ec..81194e6 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -390,6 +390,9 @@
 	int (*clone_range)(const unsigned int, struct cifsFileInfo *src_file,
 			struct cifsFileInfo *target_file, u64 src_off, u64 len,
 			u64 dest_off);
+	int (*duplicate_extents)(const unsigned int, struct cifsFileInfo *src,
+			struct cifsFileInfo *target_file, u64 src_off, u64 len,
+			u64 dest_off);
 	int (*validate_negotiate)(const unsigned int, struct cifs_tcon *);
 	ssize_t (*query_all_EAs)(const unsigned int, struct cifs_tcon *,
 			const unsigned char *, const unsigned char *, char *,
diff --git a/fs/cifs/cifspdu.h b/fs/cifs/cifspdu.h
index 998a66f..47b030d 100644
--- a/fs/cifs/cifspdu.h
+++ b/fs/cifs/cifspdu.h
@@ -2255,6 +2255,8 @@
 
 
 /* List of FileSystemAttributes - see 2.5.1 of MS-FSCC */
+#define FILE_SUPPORTS_SPARSE_VDL	0x10000000 /* faster nonsparse extend */
+#define FILE_SUPPORTS_BLOCK_REFCOUNTING	0x08000000 /* allow ioctl dup extents */
 #define FILE_SUPPORT_INTEGRITY_STREAMS	0x04000000
 #define FILE_SUPPORTS_USN_JOURNAL	0x02000000
 #define FILE_SUPPORTS_OPEN_BY_FILE_ID	0x01000000
diff --git a/fs/cifs/ioctl.c b/fs/cifs/ioctl.c
index 8b7898b..7843b19 100644
--- a/fs/cifs/ioctl.c
+++ b/fs/cifs/ioctl.c
@@ -31,12 +31,14 @@
 #include "cifsproto.h"
 #include "cifs_debug.h"
 #include "cifsfs.h"
+#include <linux/btrfs.h>
 
 #define CIFS_IOCTL_MAGIC	0xCF
 #define CIFS_IOC_COPYCHUNK_FILE	_IOW(CIFS_IOCTL_MAGIC, 3, int)
 
 static long cifs_ioctl_clone(unsigned int xid, struct file *dst_file,
-			unsigned long srcfd, u64 off, u64 len, u64 destoff)
+			unsigned long srcfd, u64 off, u64 len, u64 destoff,
+			bool dup_extents)
 {
 	int rc;
 	struct cifsFileInfo *smb_file_target = dst_file->private_data;
@@ -109,9 +111,14 @@
 	truncate_inode_pages_range(&target_inode->i_data, destoff,
 				   PAGE_CACHE_ALIGN(destoff + len)-1);
 
-	if (target_tcon->ses->server->ops->clone_range)
+	if (dup_extents && target_tcon->ses->server->ops->duplicate_extents)
+		rc = target_tcon->ses->server->ops->duplicate_extents(xid,
+			smb_file_src, smb_file_target, off, len, destoff);
+	else if (!dup_extents && target_tcon->ses->server->ops->clone_range)
 		rc = target_tcon->ses->server->ops->clone_range(xid,
 			smb_file_src, smb_file_target, off, len, destoff);
+	else
+		rc = -EOPNOTSUPP;
 
 	/* force revalidate of size and timestamps of target file now
 	   that target is updated on the server */
@@ -205,7 +212,10 @@
 			}
 			break;
 		case CIFS_IOC_COPYCHUNK_FILE:
-			rc = cifs_ioctl_clone(xid, filep, arg, 0, 0, 0);
+			rc = cifs_ioctl_clone(xid, filep, arg, 0, 0, 0, false);
+			break;
+		case BTRFS_IOC_CLONE:
+			rc = cifs_ioctl_clone(xid, filep, arg, 0, 0, 0, true);
 			break;
 		default:
 			cifs_dbg(FYI, "unsupported ioctl\n");
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index c7d228c..b1e9c0f 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -806,6 +806,53 @@
 			    cfile->fid.volatile_fid, cfile->pid, &eof, false);
 }
 
+#ifdef CONFIG_CIFS_SMB311
+static int
+smb2_duplicate_extents(const unsigned int xid,
+			struct cifsFileInfo *srcfile,
+			struct cifsFileInfo *trgtfile, u64 src_off,
+			u64 len, u64 dest_off)
+{
+	int rc;
+	unsigned int ret_data_len;
+	char *retbuf = NULL;
+	struct duplicate_extents_to_file dup_ext_buf;
+	struct cifs_tcon *tcon = tlink_tcon(trgtfile->tlink);
+
+	/* server fileays advertise duplicate extent support with this flag */
+	if ((le32_to_cpu(tcon->fsAttrInfo.Attributes) &
+	     FILE_SUPPORTS_BLOCK_REFCOUNTING) == 0)
+		return -EOPNOTSUPP;
+
+	dup_ext_buf.VolatileFileHandle = srcfile->fid.volatile_fid;
+	dup_ext_buf.PersistentFileHandle = srcfile->fid.persistent_fid;
+	dup_ext_buf.SourceFileOffset = cpu_to_le64(src_off);
+	dup_ext_buf.TargetFileOffset = cpu_to_le64(dest_off);
+	dup_ext_buf.ByteCount = cpu_to_le64(len);
+	cifs_dbg(FYI, "duplicate extents: src off %lld dst off %lld len %lld",
+		src_off, dest_off, len);
+
+	rc = smb2_set_file_size(xid, tcon, trgtfile, dest_off + len, false);
+	if (rc)
+		goto duplicate_extents_out;
+
+	rc = SMB2_ioctl(xid, tcon, trgtfile->fid.persistent_fid,
+			trgtfile->fid.volatile_fid,
+			FSCTL_DUPLICATE_EXTENTS_TO_FILE,
+			true /* is_fsctl */, (char *)&dup_ext_buf,
+			sizeof(struct duplicate_extents_to_file),
+			(char **)&retbuf,
+			&ret_data_len);
+
+	if (ret_data_len > 0)
+		cifs_dbg(FYI, "non-zero response length in duplicate extents");
+
+duplicate_extents_out:
+	return rc;
+}
+#endif /* CONFIG_CIFS_SMB311 */
+
+
 static int
 smb2_set_compression(const unsigned int xid, struct cifs_tcon *tcon,
 		   struct cifsFileInfo *cfile)
@@ -1714,6 +1761,7 @@
 	.create_lease_buf = smb3_create_lease_buf,
 	.parse_lease_buf = smb3_parse_lease_buf,
 	.clone_range = smb2_clone_range,
+	.duplicate_extents = smb2_duplicate_extents,
 /*	.validate_negotiate = smb3_validate_negotiate, */ /* not used in 3.11 */
 	.wp_retry_size = smb2_wp_retry_size,
 	.dir_needs_close = smb2_dir_needs_close,
diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
index 725283a..8e7bbe5 100644
--- a/fs/cifs/smb2pdu.h
+++ b/fs/cifs/smb2pdu.h
@@ -654,6 +654,14 @@
 	__le16 CompressionState; /* See cifspdu.h for possible flag values */
 } __packed;
 
+struct duplicate_extents_to_file {
+	__u64 PersistentFileHandle; /* source file handle, opaque endianness */
+	__u64 VolatileFileHandle;
+	__le64 SourceFileOffset;
+	__le64 TargetFileOffset;
+	__le64 ByteCount;  /* Bytes to be copied */
+} __packed;
+
 struct smb2_ioctl_req {
 	struct smb2_hdr hdr;
 	__le16 StructureSize;	/* Must be 57 */
diff --git a/fs/cifs/smbfsctl.h b/fs/cifs/smbfsctl.h
index 83efa59..d098da6 100644
--- a/fs/cifs/smbfsctl.h
+++ b/fs/cifs/smbfsctl.h
@@ -78,6 +78,7 @@
 #define FSCTL_QUERY_ALLOCATED_RANGES 0x000940CF /* BB add struct */
 #define FSCTL_SET_DEFECT_MANAGEMENT  0x00098134 /* BB add struct */
 #define FSCTL_FILE_LEVEL_TRIM        0x00098208 /* BB add struct */
+#define FSCTL_DUPLICATE_EXTENTS_TO_FILE 0x00098344
 #define FSCTL_SIS_LINK_FILES         0x0009C104
 #define FSCTL_PIPE_PEEK              0x0011400C /* BB add struct */
 #define FSCTL_PIPE_TRANSCEIVE        0x0011C017 /* BB add struct */