[PATCH v3] generic: add OFD lock tests

[Xiong Zhou <xzhou@redhat.com>]

The basic idea is placing a type of lock in one process,
eg WRLCK, on a testfile in SCRATCH_MNT, then do fcntl
getlk with a type of lock, eg RDLCK, in another process.
In the end, we check the returned flock.l_type by getlk
to see if the lock mechanism works fine.

We can also test these situations:
that the two locks are conflicting or not;
that open testfile RDONLY or RDWR.

Signed-off-by: Xiong Zhou <xzhou@redhat.com>
---

v3:
  Use golden output to match test result;
  Use semaphore to sync getlk/setlk;
  Add option parse to the test programme;
  Add a testrun code path for the helper;
  Add more comments;
  Skip the not stable /proc/locks check.

 .gitignore            |   1 +
 common/rc             |  11 +++
 src/Makefile          |   3 +-
 src/t_ofd_locks.c     | 262 ++++++++++++++++++++++++++++++++++++++++++++++++++
 tests/generic/466     | 119 +++++++++++++++++++++++
 tests/generic/466.out |  13 +++
 tests/generic/group   |   1 +
 7 files changed, 409 insertions(+), 1 deletion(-)
 create mode 100644 src/t_ofd_locks.c
 create mode 100755 tests/generic/466
 create mode 100644 tests/generic/466.out

diff --git a/.gitignore b/.gitignore
index 2014c08..77acb42 100644
--- a/.gitignore
+++ b/.gitignore
@@ -126,6 +126,7 @@
 /src/t_mmap_write_ro
 /src/t_mmap_writev
 /src/t_mtab
+/src/t_ofd_locks
 /src/t_readdir_1
 /src/t_readdir_2
 /src/t_rename_overwrite
diff --git a/common/rc b/common/rc
index e2a8229..983a214 100644
--- a/common/rc
+++ b/common/rc
@@ -3192,6 +3192,17 @@ _require_test_fcntl_advisory_locks()
 		_notrun "Require fcntl advisory locks support"
 }
 
+_require_ofd_locks()
+{
+	# Give a test run by setlk/getlk rdlck on testfile.
+	# If the running kernel does not support OFD locks,
+	# EINVAL will be returned.
+	touch $TEST_DIR/ofd_testfile || \
+		_notrun "Something wrong with $TEST_DIR"
+	src/t_ofd_locks -t $TEST_DIR/ofd_testfile > /dev/null 2>&1
+	[ $? -eq 22 ] && _notrun "Require OFD locks support"
+}
+
 _require_test_lsattr()
 {
 	testio=$(lsattr -d $TEST_DIR 2>&1)
diff --git a/src/Makefile b/src/Makefile
index 3eb25b1..f37af74 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -13,7 +13,8 @@ TARGETS = dirstress fill fill2 getpagesize holes lstat64 \
 	multi_open_unlink dmiperf unwritten_sync genhashnames t_holes \
 	t_mmap_writev t_truncate_cmtime dirhash_collide t_rename_overwrite \
 	holetest t_truncate_self t_mmap_dio af_unix t_mmap_stale_pmd \
-	t_mmap_cow_race t_mmap_fallocate fsync-err t_mmap_write_ro
+	t_mmap_cow_race t_mmap_fallocate fsync-err t_mmap_write_ro \
+	t_ofd_locks
 
 LINUX_TARGETS = xfsctl bstat t_mtab getdevicesize preallo_rw_pattern_reader \
 	preallo_rw_pattern_writer ftrunc trunc fs_perms testx looptest \
diff --git a/src/t_ofd_locks.c b/src/t_ofd_locks.c
new file mode 100644
index 0000000..f87c9c5
--- /dev/null
+++ b/src/t_ofd_locks.c
@@ -0,0 +1,262 @@
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/ipc.h>
+#include <sys/sem.h>
+
+/*
+ * In distributions that do not have these macros ready in
+ * glibc-headers, compilation fails. Adding them here to avoid
+ * build errors, relevant tests would fail at the helper which
+ * requires OFD locks support and notrun if the kernel does not
+ * support OFD locks. If the kernel does support OFD locks,
+ * we are good to go.
+ *
+ */
+#ifndef F_OFD_GETLK
+#define F_OFD_GETLK    36
+#endif
+
+#ifndef F_OFD_SETLK
+#define F_OFD_SETLK    37
+#endif
+
+#ifndef F_OFD_SETLKW
+#define F_OFD_SETLKW   38
+#endif
+
+/* This is required by semctl to set semaphore value */
+union semun {
+	int              val;    /* Value for SETVAL */
+	struct semid_ds *buf;    /* Buffer for IPC_STAT, IPC_SET */
+	unsigned short  *array;  /* Array for GETALL, SETALL */
+	struct seminfo  *__buf;  /* Buffer for IPC_INFO
+				    (Linux-specific) */
+};
+
+int fd;
+
+void err_exit(char *op, int errn)
+{
+	fprintf(stderr, "%s: %s\n", op, strerror(errn));
+	if (fd > 0)
+		close(fd);
+	exit(errn);
+}
+
+int main(int argc, char **argv)
+{
+	/* Five flags that used to specify operation details.
+	 * They can be specified via command line options.
+	 *
+	 * option: -s/-g
+	 * lock_cmd : 1 <--> setlk
+	 *	      0 <--> getlk
+	 *
+	 * option: -r/-w
+	 * lock_rw : 1 <--> set/get wrlck
+	 *	     0 <--> set/get rdlck
+	 *
+	 * option: -o num
+	 * lock_start : l_start to getlk
+	 *
+	 * option: -R/-W
+	 * open_rw : 1 <--> open file RDWR
+	 *	     0 <--> open file RDONLY
+	 *
+	 * This option is for _require_ofd_locks helper, just do
+	 * fcntl setlk then return errno.
+	 * option: -t
+	 * testrun : 1 <--> this is a testrun, return after setlk
+	 *	     0 <--> this is not a testrun, run as usual
+	 */
+
+	/* By default, we setlk WRLCK on [0,9], opening file RDWR.
+	 */
+
+	int lock_cmd = 1;
+	int lock_rw = 1;
+	int lock_start = 0;
+	int open_rw = 1;
+	int testrun = 0;
+
+	/* We use semaphore to synchronize between getlk and setlk.
+	 *
+	 * Although we run getlk routine after running setlk routine
+	 * in background, getlk still can be executed before setlk
+	 * sometimes, which is invalid for our tests.
+	 *
+	 * In setlk routine, we wait getlk done, then exit, making sure
+	 * the lock is still there when doing getlk.
+	 *
+	 * In getlk routine, we wait till setlk done firstly, making
+	 * sure the lock is valid at that time, then we do getlk,
+	 * after that, we tell setlk we are done, then exit.
+	 */
+	key_t semkey;
+	unsigned short vals[2];
+	union semun arg;
+	int semid;
+	struct sembuf sop;
+
+	struct flock flk = {
+		.l_whence = SEEK_SET,
+		.l_start = 0,
+		.l_len = 10,     /* lock range [0,9] */
+		.l_type = F_RDLCK,
+		.l_pid = 0,
+	};
+
+	int opt;
+
+	while((opt = getopt(argc, argv, "sgrwo:RWt")) != -1) {
+		switch(opt) {
+		case 's':
+			lock_cmd = 1;
+			break;
+		case 'g':
+			lock_cmd = 0;
+			break;
+		case 'r':
+			lock_rw = 0;
+			break;
+		case 'w':
+			lock_rw = 1;
+			break;
+		case 'o':
+			lock_start = atoi(optarg);
+			break;
+		case 'R':
+			open_rw = 0;
+			break;
+		case 'W':
+			open_rw = 1;
+			break;
+		case 't':
+			testrun = 1;
+			break;
+		default:
+			printf("Usage: %s [-sgrwo:RW] filename\n", argv[0]);
+			return -1;
+		}
+	}
+
+	if (lock_rw == 1)
+		flk.l_type = F_WRLCK;
+	else
+		flk.l_type = F_RDLCK;
+
+	if (open_rw == 0)
+		fd = open(argv[optind], O_RDONLY);
+	else
+		fd = open(argv[optind], O_RDWR);
+	if (fd == -1)
+		err_exit("open", errno);
+
+	/* In a testun, we do a fcntl getlk call and exit
+	 * immediately no matter it succeeds or not.
+	 */
+	if (testrun == 1) {
+		if (fcntl(fd, F_OFD_GETLK, &flk) < 0)
+			err_exit("test_ofd_getlk", errno);
+		if (fd > 0)
+			close(fd);
+		exit(0);
+	}
+
+	/* Init the semaphore, with key related to the same file.
+	 * If the sem set has not been created, we initialnize it.
+	 * If it exists, we semget again to get the exist one.
+	 * To make sure getlk routine and setlk routine are looking
+	 * at the same semaphore set in one single round of test.
+	 */
+	if((semkey = ftok("ofd_key", 255)) == -1)
+		err_exit("ftok", errno);
+	semid = semget(semkey, 2, IPC_CREAT|IPC_EXCL);
+	if (semid < 0) {
+		/* The sem exists or errer happens. */
+		if (errno != EEXIST)
+			err_exit("semget0", errno);
+
+		semid = semget(semkey, 2, 0);
+		if (semid < 0)
+			err_exit("semget1", errno);
+	} else {
+		/* Init both new sem to 1. */
+		vals[0] = 1;
+		vals[1] = 1;
+		arg.array = vals;
+		if (semctl(semid, 2, SETALL, arg) == -1)
+			err_exit("init sem", errno);
+	}
+
+	/* setlk */
+	if (lock_cmd == 1) {
+		if (fcntl(fd, F_OFD_SETLKW, &flk) < 0)
+			err_exit("ofd_setlkw", errno);
+
+		/* set sem0 to 0 after setlk done */
+		arg.val = 0;
+		if (semctl(semid, 0, SETVAL, arg) == -1)
+			err_exit("set sem0 0", errno);
+
+		/* wating sem 1 to be zero */
+		sop.sem_num = 1;
+		sop.sem_op = 0;
+		sop.sem_flg = 0;
+		if (semop(semid, &sop, 1) == -1)
+			err_exit("wait sem1 0", errno);
+
+		/* remove sem set after one round of test */
+		if (semctl(semid, 2, IPC_RMID, arg) == -1)
+			err_exit("rmid", errno);
+	}
+
+	/* getlck */
+	if (lock_cmd == 0) {
+		flk.l_start = lock_start;
+
+		/* wating sem 0 to be zero */
+		sop.sem_num = 0;
+		sop.sem_op = 0;
+		sop.sem_flg = 0;
+		if (semop(semid, &sop, 1) == -1)
+			err_exit("wait sem0 0", errno);
+
+		if (fcntl(fd, F_OFD_GETLK, &flk) < 0)
+			err_exit("ofd_getlk", errno);
+
+		/* set sem1 to 0 after getlk done */
+		arg.val = 0;
+		if (semctl(semid, 1, SETVAL, arg) == -1)
+			err_exit("set sem1 0", errno);
+
+		switch (flk.l_type) {
+		case F_UNLCK:
+			printf("lock could be placed\n");
+			break;
+		case F_RDLCK:
+			printf("get rdlck\n");
+			break;
+		case F_WRLCK:
+			printf("get wrlck\n");
+			break;
+		default:
+			printf("error\n");
+			close(fd);
+			return 0;
+		}
+	}
+
+	close(fd);
+	return 0;
+}
diff --git a/tests/generic/466 b/tests/generic/466
new file mode 100755
index 0000000..8903af4
--- /dev/null
+++ b/tests/generic/466
@@ -0,0 +1,119 @@
+#! /bin/bash
+# FS QA Test 466
+#
+# Test OFD locks, F_OFD_SETLK/F_OFD_GETLK
+#
+# The basic idea is placing a type of lock in one process,
+# eg WRLCK, on a testfile in SCRATCH_MNT, then do fcntl
+# getlk with a type of lock, eg RDLCK, in another process.
+# In the end, we check the returned flock.l_type by getlk
+# to see if the lock mechanism works fine.
+#
+# We can also test these situations:
+# that the two locks are conflicting or not;
+# that open testfile RDONLY or RDWR.
+#
+#-----------------------------------------------------------------------
+# Copyright (c) 2017 Red Hat Inc.  All Rights Reserved.
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it would be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write the Free Software Foundation,
+# Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+#-----------------------------------------------------------------------
+#
+
+seq=`basename $0`
+seqres=$RESULT_DIR/$seq
+echo "QA output created by $seq"
+
+here=`pwd`
+tmp=/tmp/$$
+status=1	# failure is the default!
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+_cleanup()
+{
+	rm -f ofd_key
+	cd /
+	rm -f $tmp.*
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+
+# remove previous $seqres.full before test
+rm -f $seqres.full
+
+# Modify as appropriate.
+_supported_fs generic
+_supported_os Linux
+_require_scratch
+_require_test_program "t_ofd_locks"
+_require_ofd_locks
+
+# real QA test starts here
+_scratch_mkfs >> $seqres.full 2>&1
+
+# prepare a 4k test file
+$XFS_IO_PROG -f -c "pwrite -S 0xFF 0 4096" \
+	$SCRATCH_MNT/testfile >> $seqres.full 2>&1
+
+do_test()
+{
+	local soptions="$1"
+	local goptions="$2"
+	rm -f fifo
+	echo $* >> $seqres.full 2>&1
+	# -s : do setlk
+	src/t_ofd_locks -s $soptions $SCRATCH_MNT/testfile &
+	# -g : do getlk
+	src/t_ofd_locks -g $goptions $SCRATCH_MNT/testfile
+	wait
+}
+
+# For the semaphore to sync getlk and getlk
+touch ofd_key
+
+# Always setlk at range [0,9], getlk at range [0,9] or [20,29].
+# To open file RDONLY or RDWR should not break the locks.
+
+# -w : operate on F_WRLCK
+# -r : operate on F_RDLCK
+# -R : open file RDONLY
+# -W : open file RDWR
+# -o : file offset where the lock starts
+
+# setlk wrlck [0,9], getlk wrlck [0,9], expect wrlck
+do_test "-w" "-w"
+# setlk wrlck [0,9], getlk wrlck [20,29], expect unlck
+do_test "-w" "-w -o 20"
+# setlk wrlck [0,9], getlk rdlck [0,9], expect wrlck
+do_test "-w" "-r"
+# setlk wrlck [0,9], getlk rdlck [20,29], expect unlck
+do_test "-w" "-r -o 20"
+# setlk rdlck [0,9], getlk wrlck [0,9], expect rdlck
+do_test "-r -R" "-w -R"
+do_test "-r" "-w"
+# setlk rdlck [0,9], getlk wrlck [20,29], expect unlck
+do_test "-r -R" "-w -o 20 -R"
+do_test "-r" "-w -o 20"
+# setlk rdlck [0,9], getlk rdlck [0,9], expect unlck
+do_test "-r -R" "-r -R"
+do_test "-r" "-r"
+# setlk rdlck [0,9], getlk rdlck [0,9], expect unlck
+do_test "-r -R" "-r -o 20 -R"
+do_test "-r" "-r -o 20"
+
+# success, all done
+status=0
+exit
diff --git a/tests/generic/466.out b/tests/generic/466.out
new file mode 100644
index 0000000..89c77fe
--- /dev/null
+++ b/tests/generic/466.out
@@ -0,0 +1,13 @@
+QA output created by 466
+get wrlck
+lock could be placed
+get wrlck
+lock could be placed
+get rdlck
+get rdlck
+lock could be placed
+lock could be placed
+lock could be placed
+lock could be placed
+lock could be placed
+lock could be placed
diff --git a/tests/generic/group b/tests/generic/group
index fbe0a7f..b716440 100644
--- a/tests/generic/group
+++ b/tests/generic/group
@@ -468,3 +468,4 @@
 463 auto quick clone dangerous
 464 auto rw
 465 auto rw quick aio
+466 auto quick
-- 
1.8.3.1