src/internal/poll/sendfile_bsd.go | 17 ++++++++++++++++-

diff --git a/src/internal/poll/sendfile_bsd.go b/src/internal/poll/sendfile_bsd.go
index 0b0966815deedd1876a203ae0ad121c22fb3d809..341e07ca1fed6a33545bead6fadd791f70a0c3bf 100644
--- a/src/internal/poll/sendfile_bsd.go
+++ b/src/internal/poll/sendfile_bsd.go
@@ -32,13 +32,28 @@ 		n := maxSendfileSize
 		if int64(n) > remain {
 			n = int(remain)
 		}
+		m := n
 		pos1 := pos
 		n, err = syscall.Sendfile(dst, src, &pos1, n)
 		if n > 0 {
 			pos += int64(n)
 			written += int64(n)
 			remain -= int64(n)
-			continue
+			// (n, nil) indicates that sendfile(2) has transferred
+			// the exact number of bytes we requested, or some unretryable
+			// error have occurred with partial bytes sent. Either way, we
+			// don't need to go through the following logic to check EINTR
+			// or fell into dstFD.pd.waitWrite, just continue to send the
+			// next chunk or break the loop.
+			if n == m {
+				continue
+			} else if err != syscall.EAGAIN &&
+				err != syscall.EINTR &&
+				err != syscall.EBUSY {
+				// Particularly, EPIPE. Errors like that would normally lead
+				// the subsequent sendfile(2) call to (-1, EBADF).
+				break
+			}
 		} else if err != syscall.EAGAIN && err != syscall.EINTR {
 			// This includes syscall.ENOSYS (no kernel
 			// support) and syscall.EINVAL (fd types which