diff --git a/src/backend/storage/file/copydir.c b/src/backend/storage/file/copydir.c
index 6cfb816..719a5c1 100644
--- a/src/backend/storage/file/copydir.c
+++ b/src/backend/storage/file/copydir.c
@@ -22,6 +22,10 @@
 #include <unistd.h>
 #include <sys/stat.h>
 
+#ifdef HAVE_SYS_IOCTL_H
+#include <sys/ioctl.h>
+#endif
+
 #include "storage/copydir.h"
 #include "storage/fd.h"
 #include "miscadmin.h"
@@ -139,6 +143,24 @@ copydir(char *fromdir, char *todir, bool recurse)
 }
 
 /*
+ * Perform the O(1) btrfs clone operation, if possible.
+ * Upon success, return 0.  Otherwise, return -1.
+ */
+static inline int
+clone_file (int dest_fd, int src_fd)
+{
+#ifdef __linux__
+# define BTRFS_IOCTL_MAGIC 0x94
+# define BTRFS_IOC_CLONE _IOW (BTRFS_IOCTL_MAGIC, 9, int)
+	return ioctl (dest_fd, BTRFS_IOC_CLONE, src_fd);
+#else
+	(void) dest_fd;
+	(void) src_fd;
+	return -1;
+#endif
+}
+
+/*
  * copy one file
  */
 void
@@ -150,11 +172,6 @@ copy_file(char *fromfile, char *tofile)
 	int			nbytes;
 	off_t		offset;
 
-	/* Use palloc to ensure we get a maxaligned buffer */
-#define COPY_BUF_SIZE (8 * BLCKSZ)
-
-	buffer = palloc(COPY_BUF_SIZE);
-
 	/*
 	 * Open the files
 	 */
@@ -171,38 +188,54 @@ copy_file(char *fromfile, char *tofile)
 				(errcode_for_file_access(),
 				 errmsg("could not create file \"%s\": %m", tofile)));
 
-	/*
-	 * Do the data copying.
-	 */
-	for (offset = 0;; offset += nbytes)
+	if (clone_file (dstfd, srcfd) == 0)
+		ereport(DEBUG1, (errmsg("Cloned \"%s\" to \"%s\".", fromfile, tofile)));
+
+	else
 	{
-		/* If we got a cancel signal during the copy of the file, quit */
-		CHECK_FOR_INTERRUPTS();
+		/*
+		 * Do the data copying.
+		 */
 
-		nbytes = read(srcfd, buffer, COPY_BUF_SIZE);
-		if (nbytes < 0)
-			ereport(ERROR,
-					(errcode_for_file_access(),
-					 errmsg("could not read file \"%s\": %m", fromfile)));
-		if (nbytes == 0)
-			break;
-		errno = 0;
-		if ((int) write(dstfd, buffer, nbytes) != nbytes)
+		/* Use palloc to ensure we get a maxaligned buffer */
+#define COPY_BUF_SIZE (8 * BLCKSZ)
+
+		buffer = palloc(COPY_BUF_SIZE);
+
+		ereport(DEBUG1, (errmsg("Copying \"%s\" to \"%s\" in userspace.",
+								fromfile, tofile)));
+		for (offset = 0;; offset += nbytes)
 		{
-			/* if write didn't set errno, assume problem is no disk space */
-			if (errno == 0)
-				errno = ENOSPC;
-			ereport(ERROR,
-					(errcode_for_file_access(),
-					 errmsg("could not write to file \"%s\": %m", tofile)));
+			/* If we got a cancel signal during the copy of the file, quit */
+			CHECK_FOR_INTERRUPTS();
+
+			nbytes = read(srcfd, buffer, COPY_BUF_SIZE);
+			if (nbytes < 0)
+				ereport(ERROR,
+						(errcode_for_file_access(),
+						 errmsg("could not read file \"%s\": %m", fromfile)));
+			if (nbytes == 0)
+				break;
+			errno = 0;
+			if ((int) write(dstfd, buffer, nbytes) != nbytes)
+			{
+				/* if write didn't set errno, assume problem is no disk space */
+				if (errno == 0)
+					errno = ENOSPC;
+				ereport(ERROR,
+						(errcode_for_file_access(),
+						 errmsg("could not write to file \"%s\": %m", tofile)));
+			}
+
+			/*
+			 * We fsync the files later but first flush them to avoid spamming the
+			 * cache and hopefully get the kernel to start writing them out before
+			 * the fsync comes.
+			 */
+			pg_flush_data(dstfd, offset, nbytes);
 		}
 
-		/*
-		 * We fsync the files later but first flush them to avoid spamming the
-		 * cache and hopefully get the kernel to start writing them out before
-		 * the fsync comes.
-		 */
-		pg_flush_data(dstfd, offset, nbytes);
+		pfree(buffer);
 	}
 
 	if (close(dstfd))
@@ -212,7 +245,6 @@ copy_file(char *fromfile, char *tofile)
 
 	close(srcfd);
 
-	pfree(buffer);
 }