4 files changed, 205 insertions, 0 deletions
diff --git a/tests/zfs-tests/cmd/Makefile.am b/tests/zfs-tests/cmd/Makefile.am
index 0673fcbf6..751836ae4 100644
--- a/tests/zfs-tests/cmd/Makefile.am
+++ b/tests/zfs-tests/cmd/Makefile.am
@@ -18,6 +18,7 @@ SUBDIRS = \
 	mmapwrite \
 	nvlist_to_lua \
 	randfree_file \
+	randwritecomp \
 	readmmap \
 	rename_dir \
 	rm_lnkcnt_zero_file \
diff --git a/tests/zfs-tests/cmd/randwritecomp/.gitignore b/tests/zfs-tests/cmd/randwritecomp/.gitignore
new file mode 100644
index 000000000..fb231c678
--- /dev/null
+++ b/tests/zfs-tests/cmd/randwritecomp/.gitignore
@@ -0,0 +1 @@
+/randwritecomp
diff --git a/tests/zfs-tests/cmd/randwritecomp/Makefile.am b/tests/zfs-tests/cmd/randwritecomp/Makefile.am
new file mode 100644
index 000000000..0002291fa
--- /dev/null
+++ b/tests/zfs-tests/cmd/randwritecomp/Makefile.am
@@ -0,0 +1,9 @@
+include $(top_srcdir)/config/Rules.am
+
+pkgexecdir = $(datadir)/@PACKAGE@/zfs-tests/bin
+
+DEFAULT_INCLUDES += \
+	-I$(top_srcdir)/include
+
+pkgexec_PROGRAMS = randwritecomp
+randwritecomp_SOURCES = randwritecomp.c
diff --git a/tests/zfs-tests/cmd/randwritecomp/randwritecomp.c b/tests/zfs-tests/cmd/randwritecomp/randwritecomp.c
new file mode 100644
index 000000000..708d5ee90
--- /dev/null
+++ b/tests/zfs-tests/cmd/randwritecomp/randwritecomp.c
@@ -0,0 +1,194 @@
+/*
+ * This file and its contents are supplied under the terms of the
+ * Common Development and Distribution License ("CDDL"), version 1.0.
+ * You may only use this file in accordance with the terms of version
+ * 1.0 of the CDDL.
+ *
+ * A full copy of the text of the CDDL should have accompanied this
+ * source.  A copy of the CDDL is also available via the Internet at
+ * http://www.illumos.org/license/CDDL.
+ */
+
+/*
+ * Copyright (c) 2017 by Delphix. All rights reserved.
+ */
+
+/*
+ * The following is defined so the source can use
+ * lrand48() and srand48().
+ */
+#define	__EXTENSIONS__
+
+#include <stdint.h>
+#include <string.h>
+#include "../file_common.h"
+
+/*
+ * The following sample was derived from real-world data
+ * of a production Oracle database.
+ */
+static uint64_t size_distribution[] = {
+	0,
+	1499018,
+	352084,
+	1503485,
+	4206227,
+	5626657,
+	5387001,
+	3733756,
+	2233094,
+	874652,
+	238635,
+	81434,
+	33357,
+	13106,
+	2009,
+	1,
+	23660,
+};
+
+
+static uint64_t distribution_n;
+
+static uint8_t randbuf[BLOCKSZ];
+
+static void
+rwc_pwrite(int fd, const void *buf, size_t nbytes, off_t offset)
+{
+	size_t nleft = nbytes;
+	ssize_t nwrite = 0;
+
+	nwrite = pwrite(fd, buf, nbytes, offset);
+	if (nwrite < 0) {
+		perror("pwrite");
+		exit(EXIT_FAILURE);
+	}
+
+	nleft -= nwrite;
+	if (nleft != 0) {
+		(void) fprintf(stderr, "warning: pwrite: "
+		    "wrote %zu out of %zu bytes\n",
+		    (nbytes - nleft), nbytes);
+	}
+}
+
+static void
+fillbuf(char *buf)
+{
+	uint64_t rv = lrand48() % distribution_n;
+	uint64_t sum = 0;
+
+	uint64_t i;
+	for (i = 0;
+	    i < sizeof (size_distribution) / sizeof (size_distribution[0]);
+	    i++) {
+		sum += size_distribution[i];
+		if (rv < sum)
+			break;
+	}
+
+	bcopy(randbuf, buf, BLOCKSZ);
+	if (i == 0)
+		bzero(buf, BLOCKSZ - 10);
+	else if (i < 16)
+		bzero(buf, BLOCKSZ - i * 512 + 256);
+	/*LINTED: E_BAD_PTR_CAST_ALIGN*/
+	((uint32_t *)buf)[0] = lrand48();
+}
+
+static void
+exit_usage(void)
+{
+	(void) printf("usage: ");
+	(void) printf("randwritecomp <file> [-s] [nwrites]\n");
+	exit(EXIT_FAILURE);
+}
+
+static void
+sequential_writes(int fd, char *buf, uint64_t nblocks, int64_t n)
+{
+	for (int64_t i = 0; n == -1 || i < n; i++) {
+		fillbuf(buf);
+
+		static uint64_t j = 0;
+		if (j == 0)
+			j = lrand48() % nblocks;
+		rwc_pwrite(fd, buf, BLOCKSZ, j * BLOCKSZ);
+		j++;
+		if (j >= nblocks)
+			j = 0;
+	}
+}
+
+static void
+random_writes(int fd, char *buf, uint64_t nblocks, int64_t n)
+{
+	for (int64_t i = 0; n == -1 || i < n; i++) {
+		fillbuf(buf);
+		rwc_pwrite(fd, buf, BLOCKSZ, (lrand48() % nblocks) * BLOCKSZ);
+	}
+}
+
+int
+main(int argc, char *argv[])
+{
+	int fd, err;
+	char *filename = NULL;
+	char buf[BLOCKSZ];
+	struct stat ss;
+	uint64_t nblocks;
+	int64_t n = -1;
+	int sequential = 0;
+
+	if (argc < 2)
+		exit_usage();
+
+	argv++;
+	if (strcmp("-s", argv[0]) == 0) {
+		sequential = 1;
+		argv++;
+	}
+
+	if (argv[0] == NULL)
+		exit_usage();
+	else
+		filename = argv[0];
+
+	argv++;
+	if (argv[0] != NULL)
+		n = strtoull(argv[0], NULL, 0);
+
+	fd = open(filename, O_RDWR|O_CREAT, 0666);
+	err = fstat(fd, &ss);
+	if (err != 0) {
+		(void) fprintf(stderr,
+		    "error: fstat returned error code %d\n", err);
+		exit(EXIT_FAILURE);
+	}
+
+	nblocks = ss.st_size / BLOCKSZ;
+	if (nblocks == 0) {
+		(void) fprintf(stderr, "error: "
+		    "file is too small (min allowed size is %d bytes)\n",
+		    BLOCKSZ);
+		exit(EXIT_FAILURE);
+	}
+
+	srand48(getpid());
+	for (int i = 0; i < BLOCKSZ; i++)
+		randbuf[i] = lrand48();
+
+	distribution_n = 0;
+	for (uint64_t i = 0;
+	    i < sizeof (size_distribution) / sizeof (size_distribution[0]);
+	    i++) {
+		distribution_n += size_distribution[i];
+	}
+
+	if (sequential)
+		sequential_writes(fd, buf, nblocks, n);
+	else
+		random_writes(fd, buf, nblocks, n);
+
+	return (0);
+}