Use ftruncate() at the end of a --sparse file.

Fixes bug 7337.

fileio.c

@@ -28,24 +28,32 @@
 
 extern int sparse_files;
 
-static char last_byte;
 static OFF_T sparse_seek = 0;
 
-int sparse_end(int f)
+int sparse_end(int f, OFF_T size)
 {
 	int ret;
 
 	if (!sparse_seek)
 		return 0;
 
-	do_lseek(f, sparse_seek-1, SEEK_CUR);
-	sparse_seek = 0;
+#ifdef HAVE_FTRUNCATE
+	ret = do_ftruncate(f, size);
+#else
+	if (do_lseek(f, sparse_seek-1, SEEK_CUR) != size-1)
+		ret = -1;
+	else {
+		do {
+			ret = write(f, "", 1);
+		} while (ret < 0 && errno == EINTR);
+
+		ret = ret <= 0 ? -1 : 0;
+	}
+#endif
 
-	do {
-		ret = write(f, "", 1);
-	} while (ret < 0 && errno == EINTR);
+	sparse_seek = 0;
 
-	return ret <= 0 ? -1 : 0;
+	return ret;
 }
 
 
@@ -57,10 +65,6 @@ static int write_sparse(int f, char *buf, int len)
 	for (l1 = 0; l1 < len && buf[l1] == 0; l1++) {}
 	for (l2 = 0; l2 < len-l1 && buf[len-(l2+1)] == 0; l2++) {}
 
-	/* XXX Riddle me this: why does this function SLOW DOWN when I
-	 * remove the following (unneeded) line?? Core Duo weirdness? */
-	last_byte = buf[len-1];
-
 	sparse_seek += l1;
 
 	if (l1 == len)

receiver.c

@@ -322,8 +322,7 @@ static int receive_data(int f_in, char *fname_r, int fd_r, OFF_T size_r,
 		goto report_write_error;
 
 #ifdef HAVE_FTRUNCATE
-	if (inplace && fd != -1
-	 && ftruncate(fd, offset) < 0) {
+	if (inplace && fd != -1 && do_ftruncate(fd, offset) < 0) {
 		rsyserr(FERROR_XFER, errno, "ftruncate failed on %s",
 			full_fname(fname));
 	}
@@ -332,7 +331,7 @@ static int receive_data(int f_in, char *fname_r, int fd_r, OFF_T size_r,
 	if (INFO_GTE(PROGRESS, 1))
 		end_progress(total_size);
 
-	if (fd != -1 && offset > 0 && sparse_end(fd) != 0) {
+	if (fd != -1 && offset > 0 && sparse_end(fd, offset) != 0) {
 	    report_write_error:
 		rsyserr(FERROR_XFER, errno, "write failed on %s",
 			full_fname(fname));

syscall.c

@@ -226,6 +226,22 @@ int do_rename(const char *fname1, const char *fname2)
 	return rename(fname1, fname2);
 }
 
+#ifdef HAVE_FTRUNCATE
+int do_ftruncate(int fd, OFF_T size)
+{
+	int ret;
+
+	if (dry_run) return 0;
+	RETURN_ERROR_IF_RO_OR_LO;
+
+	do {
+		ret = ftruncate(fd, size);
+	} while (ret < 0 && errno == EINTR);
+
+	return ret;
+}
+#endif
+
 void trim_trailing_slashes(char *name)
 {
 	int l;