1 files changed, 151 insertions, 0 deletions
diff --git a/sys/contrib/openzfs/tests/zfs-tests/cmd/mmap_seek.c b/sys/contrib/openzfs/tests/zfs-tests/cmd/mmap_seek.c
new file mode 100644
index 000000000000..bb36527aafee
--- /dev/null
+++ b/sys/contrib/openzfs/tests/zfs-tests/cmd/mmap_seek.c
@@ -0,0 +1,151 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+
+/*
+ * Copyright (c) 2021 by Lawrence Livermore National Security, LLC.
+ */
+
+#include <unistd.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/sysmacros.h>
+#include <errno.h>
+#ifdef __linux__
+#include <linux/fs.h>
+#endif
+
+static void
+seek_data(int fd, off_t offset, off_t expected)
+{
+	off_t data_offset = lseek(fd, offset, SEEK_DATA);
+	if (data_offset != expected) {
+		fprintf(stderr, "lseek(fd, %d, SEEK_DATA) = %d (expected %d)\n",
+		    (int)offset, (int)data_offset, (int)expected);
+		exit(2);
+	}
+}
+
+static void
+seek_hole(int fd, off_t offset, off_t expected)
+{
+	off_t hole_offset = lseek(fd, offset, SEEK_HOLE);
+	if (hole_offset != expected) {
+		fprintf(stderr, "lseek(fd, %d, SEEK_HOLE) = %d (expected %d)\n",
+		    (int)offset, (int)hole_offset, (int)expected);
+		exit(2);
+	}
+}
+
+int
+main(int argc, char **argv)
+{
+	char *execname = argv[0];
+	char *file_path = argv[1];
+	char *buf = NULL;
+	int err;
+
+	if (argc != 4) {
+		(void) printf("usage: %s <file name> <file size> "
+		    "<block size>\n", argv[0]);
+		exit(1);
+	}
+
+	int fd = open(file_path, O_RDWR | O_CREAT, 0666);
+	if (fd == -1) {
+		(void) fprintf(stderr, "%s: %s: ", execname, file_path);
+		perror("open");
+		exit(2);
+	}
+
+	off_t file_size = atoi(argv[2]);
+	off_t block_size = atoi(argv[3]);
+
+	if (block_size * 2 > file_size) {
+		(void) fprintf(stderr, "file size must be at least "
+		    "double the block size\n");
+		exit(2);
+	}
+
+	err = ftruncate(fd, file_size);
+	if (err == -1) {
+		perror("ftruncate");
+		exit(2);
+	}
+
+	if ((buf = mmap(NULL, file_size, PROT_READ | PROT_WRITE,
+	    MAP_SHARED, fd, 0)) == MAP_FAILED) {
+		perror("mmap");
+		exit(2);
+	}
+
+	/* Verify the file is sparse and reports no data. */
+	seek_data(fd, 0, -1);
+
+	/* Verify the file is reported as a hole. */
+	seek_hole(fd, 0, 0);
+
+	/* Verify search beyond end of file is an error. */
+	seek_data(fd, 2 * file_size, -1);
+	seek_hole(fd, 2 * file_size, -1);
+
+	/* Dirty the first byte. */
+	memset(buf, 'a', 1);
+	seek_data(fd, 0, 0);
+	seek_data(fd, block_size, -1);
+	seek_hole(fd, 0, block_size);
+	seek_hole(fd, block_size, block_size);
+
+	/* Dirty the first half of the file. */
+	memset(buf, 'b', file_size / 2);
+	seek_data(fd, 0, 0);
+	seek_data(fd, block_size, block_size);
+	seek_hole(fd, 0, P2ROUNDUP(file_size / 2, block_size));
+	seek_hole(fd, block_size, P2ROUNDUP(file_size / 2, block_size));
+
+	/* Dirty the whole file. */
+	memset(buf, 'c', file_size);
+	seek_data(fd, 0, 0);
+	seek_data(fd, file_size * 3 / 4,
+	    P2ROUNDUP(file_size * 3 / 4, block_size));
+	seek_hole(fd, 0, file_size);
+	seek_hole(fd, file_size / 2, file_size);
+
+	/* Punch a hole (required compression be enabled). */
+	memset(buf + block_size, 0, block_size);
+	seek_data(fd, 0, 0);
+	seek_data(fd, block_size, 2 * block_size);
+	seek_hole(fd, 0, block_size);
+	seek_hole(fd, block_size, block_size);
+	seek_hole(fd, 2 * block_size, file_size);
+
+	err = munmap(buf, file_size);
+	if (err == -1) {
+		perror("munmap");
+		exit(2);
+	}
+
+	close(fd);
+
+	return (0);
+}