ZTS: Add dirty dnode stress test

Add a test for the dirty dnode SEEK_HOLE/SEEK_DATA bug described in
openzfs#15526

The bug was fixed in openzfs#15571 and
was backported to 2.2.2 and 2.1.14.  This test case is just to
make sure it does not come back.

seekflood.c originally written by Rob Norris.

Signed-off-by: Tony Hutter <hutter2@llnl.gov>

tests/runfiles/common.run

@@ -597,7 +597,7 @@ tests = ['compress_001_pos', 'compress_002_pos', 'compress_003_pos',
 tags = ['functional', 'compression']
 
 [tests/functional/cp_files]
-tests = ['cp_files_001_pos']
+tests = ['cp_files_001_pos', 'cp_stress']
 tags = ['functional', 'cp_files']
 
 [tests/functional/crtime]

tests/zfs-tests/tests/Makefile.am

@@ -1365,6 +1365,7 @@ nobase_dist_datadir_zfs_tests_tests_SCRIPTS += \
 	functional/compression/setup.ksh \
 	functional/cp_files/cleanup.ksh \
 	functional/cp_files/cp_files_001_pos.ksh \
+	functional/cp_files/cp_stress.ksh \
 	functional/cp_files/setup.ksh \
 	functional/crtime/cleanup.ksh \
 	functional/crtime/crtime_001_pos.ksh \

tests/zfs-tests/tests/functional/cp_files/cp_stress.ksh

@@ -0,0 +1,64 @@
+#! /bin/ksh -p
+#
+# 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 https://opensource.org/licenses/CDDL-1.0.
+# 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) 2023 by Lawrence Livermore National Security, LLC.
+#
+
+. $STF_SUITE/include/libtest.shlib
+
+#
+# DESCRIPTION:
+# This test is for the dirty dnode SEEK_HOLE/SEEK_DATA bug described in
+# https://github.com/openzfs/zfs/issues/15526
+#
+# The bug was fixed in https://github.com/openzfs/zfs/pull/15571 and
+# was backported to 2.2.2 and 2.1.14.  This test case is just to
+# make sure it does not come back.
+#
+# STRATEGY:
+#
+# 1. Run the 'seekflood' binary to create files with specific timing
+#    characteristics to trigger #15526.
+# 2. Run seekflood multiple times as seekflood doesn't always trigger it.
+
+verify_runnable "global"
+
+function cleanup
+{
+	rm -rf /$TESTDIR/cp_stress
+}
+
+log_assert "Run 'seekflood' binary multiple times to try to trigger #15526"
+
+log_onexit cleanup
+
+log_must mkdir /$TESTPOOL/cp_stress
+
+MYPWD="$PWD"
+cd /$TESTPOOL/cp_stress
+CPUS=$(get_num_cpus)
+for i in $(seq 1 10) ; do
+	log_must $STF_SUITE/tests/functional/cp_files/seekflood 2000 $CPUS
+done
+cd "$MYPWD"
+
+log_pass "No corruption detected"

tests/zfs-tests/tests/functional/cp_files/seekflood.c

@@ -23,7 +23,9 @@
  *
  */
 
+#ifndef	_GNU_SOURCE
 #define	_GNU_SOURCE
+#endif
 
 #include <fcntl.h>
 #include <unistd.h>
@@ -34,7 +36,7 @@
 #include <sys/stat.h>
 #include <sys/wait.h>
 
-#define	DATASIZE	(1024*129)
+#define	DATASIZE	(4096)
 char data[DATASIZE];
 
 static int
@@ -47,9 +49,9 @@ _open_file(int n, int wr)
 
 	if ((fd = open(buf, wr ? (O_WRONLY | O_CREAT) : O_RDONLY,
 	    wr ? (S_IRUSR | S_IWUSR) : 0)) < 0) {
-		fprintf(stderr, "E: open '%s' (%s): %s\n",
+		fprintf(stderr, "Error: open '%s' (%s): %s\n",
 		    buf, wr ? "write" : "read", strerror(errno));
-		abort();
+		exit(1);
 	}
 
 	return (fd);
@@ -61,12 +63,13 @@ _write_file(int n, int fd)
 	/* write a big ball of stuff */
 	ssize_t nwr = write(fd, data, DATASIZE);
 	if (nwr < 0) {
-		fprintf(stderr, "E: write '%d_%d': %s\n",
+		fprintf(stderr, "Error: write '%d_%d': %s\n",
 		    getpid(), n, strerror(errno));
-		abort();
+		exit(1);
 	} else if (nwr < DATASIZE) {
-		fprintf(stderr, "E: write '%d_%d': short write\n", getpid(), n);
-		abort();
+		fprintf(stderr, "Error: write '%d_%d': short write\n", getpid(),
+		    n);
+		exit(1);
 	}
 }
 
@@ -75,9 +78,9 @@ _seek_file(int n, int fd)
 {
 	struct stat st;
 	if (fstat(fd, &st) < 0) {
-		fprintf(stderr, "E: fstat '%d_%d': %s\n", getpid(), n,
+		fprintf(stderr, "Error: fstat '%d_%d': %s\n", getpid(), n,
 		    strerror(errno));
-		abort();
+		exit(1);
 	}
 
 	/* zero sized file rightly has no data, so no point seeking it */
@@ -88,15 +91,16 @@ _seek_file(int n, int fd)
 	if (lseek(fd, 0, SEEK_DATA) < 0) {
 		if (errno == ENXIO)
 			return (1);
-		fprintf(stderr, "E: lseek '%d_%d': %s\n",
+		fprintf(stderr, "Error: lseek '%d_%d': %s\n",
 		    getpid(), n, strerror(errno));
-		abort();
+		exit(2);
 	}
 
 	return (0);
 }
 
-int main(int argc, char **argv)
+int
+main(int argc, char **argv)
 {
 	int nfiles = 0;
 	int nthreads = 0;
@@ -159,13 +163,14 @@ int main(int argc, char **argv)
 	}
 
 	if (crashed) {
-		fprintf(stderr, "E: child crashed; test failed\n");
-		abort();
+		fprintf(stderr, "Error: child crashed; test failed\n");
+		exit(1);
 	}
 
 	if (count) {
-		fprintf(stderr, "E: %d seek failures; test failed\n", count);
-		abort();
+		fprintf(stderr, "Error: %d seek failures; test failed\n",
+		    count);
+		exit(1);
 	}
 
 	exit(0);