This patch adds fcntl corner cases that was being used to confirm issues
on a GFS2 filesystem. The GFS2 filesystem has it's own ->lock()
implementation and in those corner cases issues was being found and
fixed.
Signed-off-by: Alexander Aring <aahringo@xxxxxxxxxx>
---
changes since v2:
- move fcntl tests into one fcntl c file
- remove ofd and same owner tests, should be reflected by only one test
- simplify commit message (remove testname out of it)
- add error messages in fcntl.c to give more information if an error
occur
src/Makefile | 3 +-
src/fcntl.c | 322 ++++++++++++++++++++++++++++++++++++++++++
tests/generic/732 | 32 +++++
tests/generic/732.out | 2 +
4 files changed, 358 insertions(+), 1 deletion(-)
create mode 100644 src/fcntl.c
create mode 100755 tests/generic/732
create mode 100644 tests/generic/732.out
diff --git a/src/Makefile b/src/Makefile
index 2815f919..67f936d3 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -19,7 +19,8 @@ TARGETS = dirstress fill fill2 getpagesize holes lstat64 \
t_ofd_locks t_mmap_collision mmap-write-concurrent \
t_get_file_time t_create_short_dirs t_create_long_dirs t_enospc \
t_mmap_writev_overlap checkpoint_journal mmap-rw-fault allocstale \
- t_mmap_cow_memory_failure fake-dump-rootino dio-buf-fault rewinddir-test
+ t_mmap_cow_memory_failure fake-dump-rootino dio-buf-fault rewinddir-test \
+ fcntl
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/fcntl.c b/src/fcntl.c
new file mode 100644
index 00000000..8e375357
--- /dev/null
+++ b/src/fcntl.c
@@ -0,0 +1,322 @@
+// SPDX-License-Identifier: GPL-2.0+
+/* Copyright (c) 2023 Alexander Aring. All Rights Reserved.
+ */
+
+#include <pthread.h>
+#include <unistd.h>
+#include <string.h>
+#include <limits.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <wait.h>
+
+static char filename[PATH_MAX + 1];
+static int fd;
+
+static void usage(char *name, const char *msg)
+{
+ printf("Fatal: %s\nUsage:\n"
+ "%s <file for fcntl>\n", msg, name);
+ _exit(1);
+}
+
+static void *do_equal_file_lock_thread(void *arg)
+{
+ struct flock fl = {
+ .l_type = F_WRLCK,
+ .l_whence = SEEK_SET,
+ .l_start = 0L,
+ .l_len = 1L,
+ };
+ int rv;
+
+ rv = fcntl(fd, F_SETLKW, &fl);
+ if (rv == -1) {
+ perror("fcntl");
+ _exit(1);
+ }
+
+ return NULL;
+}
+
+static void do_test_equal_file_lock(void)
+{
+ struct flock fl;
+ pthread_t t[2];
+ int pid, rv;
+
+ fl.l_type = F_WRLCK;
+ fl.l_whence = SEEK_SET;
+ fl.l_start = 0L;
+ fl.l_len = 1L;
+
+ /* acquire range 0-0 */
+ rv = fcntl(fd, F_SETLK, &fl);
+ if (rv == -1) {
+ perror("fcntl");
+ _exit(1);
+ }
+
+ pid = fork();
+ if (pid == 0) {
+ rv = pthread_create(&t[0], NULL, do_equal_file_lock_thread, NULL);
+ if (rv != 0) {
+ fprintf(stderr, "failed to create pthread\n");
+ _exit(1);
+ }
+
+ rv = pthread_create(&t[1], NULL, do_equal_file_lock_thread, NULL);
+ if (rv != 0) {
+ fprintf(stderr, "failed to create pthread\n");
+ _exit(1);
+ }
+
+ pthread_join(t[0], NULL);
+ pthread_join(t[1], NULL);
+
+ _exit(0);
+ }
+
+ /* wait until threads block on 0-0 */
+ sleep(3);
+
+ fl.l_type = F_UNLCK;
+ fl.l_start = 0;
+ fl.l_len = 1;
+ rv = fcntl(fd, F_SETLK, &fl);
+ if (rv == -1) {
+ perror("fcntl");
+ _exit(1);
+ }
+
+ sleep(3);
+
+ /* check if the ->lock() implementation got the
+ * right locks granted because two waiter with the
+ * same file_lock fields are waiting
+ */
+ fl.l_type = F_WRLCK;
+ rv = fcntl(fd, F_SETLK, &fl);
+ if (rv == -1 && errno == EAGAIN) {
+ fprintf(stderr, "deadlock, pthread not cleaned up correctly\n");
+ _exit(1);
+ }
+
+ wait(NULL);
+}
+
+static void catch_alarm(int num) { }
+
+static void do_test_signal_interrupt_child(int *pfd)
+{
+ struct sigaction act;
+ unsigned char m;
+ struct flock fl;
+ int rv;
+
+ fl.l_type = F_WRLCK;
+ fl.l_whence = SEEK_SET;
+ fl.l_start = 1;
+ fl.l_len = 1;
+
+ rv = fcntl(fd, F_SETLK, &fl);
+ if (rv == -1) {
+ perror("fcntl");
+ _exit(1);
+ }
+
+ memset(&act, 0, sizeof(act));
+ act.sa_handler = catch_alarm;
+ sigemptyset(&act.sa_mask);
+ sigaddset(&act.sa_mask, SIGALRM);
+ sigaction(SIGALRM, &act, NULL);
+
+ fl.l_type = F_WRLCK;
+ fl.l_whence = SEEK_SET;
+ fl.l_start = 0;
+ fl.l_len = 1;
+
+ /* interrupt SETLKW by signal in 3 secs */
+ alarm(3);
+ rv = fcntl(fd, F_SETLKW, &fl);
+ if (rv == 0) {
+ fprintf(stderr, "fcntl interrupt successful but should fail with EINTR\n");
+ _exit(1);
+ }
+
+ /* synchronize to move parent to test region 1-1 */
+ write(pfd[1], &m, sizeof(m));
+
+ /* keep child alive */
+ read(pfd[1], &m, sizeof(m));
+}
+
+static void do_test_signal_interrupt(void)
+{
+ struct flock fl;
+ unsigned char m;
+ int pid, rv;
+ int pfd[2];
+
+ rv = pipe(pfd);
+ if (rv == -1) {
+ perror("pipe");
+ _exit(1);
+ }
+
+ fl.l_type = F_WRLCK;
+ fl.l_whence = SEEK_SET;
+ fl.l_start = 0;
+ fl.l_len = 1;
+
+ rv = fcntl(fd, F_SETLK, &fl);
+ if (rv == -1) {
+ perror("fcntl");
+ _exit(1);
+ }
+
+ pid = fork();
+ if (pid == 0) {
+ do_test_signal_interrupt_child(pfd);
+ _exit(0);
+ }
+
+ /* wait until child writes */
+ read(pfd[0], &m, sizeof(m));
+
+ fl.l_type = F_WRLCK;
+ fl.l_whence = SEEK_SET;
+ fl.l_start = 1;
+ fl.l_len = 1;
+ /* parent testing childs region, the child will think
+ * it has region 1-1 locked because it was interrupted
+ * by region 0-0. Due bugs the interruption also unlocked
+ * region 1-1.
+ */
+ rv = fcntl(fd, F_SETLK, &fl);
+ if (rv == 0) {
+ fprintf(stderr, "fcntl trylock successful but should fail because child still acquires region\n");
+ _exit(1);
+ }
+
+ write(pfd[0], &m, sizeof(m));
+
+ wait(NULL);
+
+ close(pfd[0]);
+ close(pfd[1]);
+
+ /* cleanup everything */
+ fl.l_type = F_UNLCK;
+ fl.l_whence = SEEK_SET;
+ fl.l_start = 0;
+ fl.l_len = 2;
+ rv = fcntl(fd, F_SETLK, &fl);
+ if (rv == -1) {
+ perror("fcntl");
+ _exit(1);
+ }
+}
+
+static void do_test_kill_child(void)
+{
+ struct flock fl;
+ int rv;
+
+ fl.l_type = F_WRLCK;
+ fl.l_whence = SEEK_SET;
+ fl.l_start = 0;
+ fl.l_len = 1;
+
+ rv = fcntl(fd, F_SETLKW, &fl);
+ if (rv == -1) {
+ perror("fcntl");
+ _exit(1);
+ }
+}
+
+static void do_test_kill(void)
+{
+ struct flock fl;
+ int pid_to_kill;
+ int rv;
+
+ fl.l_type = F_WRLCK;
+ fl.l_whence = SEEK_SET;
+ fl.l_start = 0;
+ fl.l_len = 1;
+
+ rv = fcntl(fd, F_SETLK, &fl);
+ if (rv == -1) {
+ perror("fcntl");
+ _exit(1);
+ }
+
+ pid_to_kill = fork();
+ if (pid_to_kill == 0) {
+ do_test_kill_child();
+ _exit(0);
+ }
+
+ /* wait until child blocks */
+ sleep(3);
+
+ kill(pid_to_kill, SIGKILL);
+
+ /* wait until Linux did plock cleanup */
+ sleep(3);
+
+ fl.l_type = F_UNLCK;
+ fl.l_whence = SEEK_SET;
+ fl.l_start = 0;
+ fl.l_len = 1;
+
+ /* cleanup parent lock */
+ rv = fcntl(fd, F_SETLK, &fl);
+ if (rv == -1) {
+ perror("fcntl");
+ _exit(1);
+ }
+
+ fl.l_type = F_WRLCK;
+ fl.l_whence = SEEK_SET;
+ fl.l_start = 0;
+ fl.l_len = 1;
+
+ /* check if the child still holds the lock
+ * and killing the child was not cleaning
+ * up locks.
+ */
+ rv = fcntl(fd, F_SETLK, &fl);
+ if ((rv == -1 && errno == EAGAIN)) {
+ fprintf(stderr, "fcntl trylock failed but should be successful because killing child should cleanup acquired lock\n");
+ _exit(1);
+ }
+}
+
+int main(int argc, char * const argv[])
+{
+ if (optind != argc - 1)
+ usage(argv[0], "<file for fcntl> is mandatory to tell the file where to run fcntl() on it");
+
+ strncpy(filename, argv[1], PATH_MAX);
+
+ fd = open(filename, O_RDWR | O_CREAT, 0700);
+ if (fd == -1) {
+ perror("open");
+ _exit(1);
+ }
+
+ /* test to have to equal struct file_lock requests in ->lock() */
+ do_test_equal_file_lock();
+ /* test to interrupt F_SETLKW by a signal and cleanup only canceled the pending interrupted request */
+ do_test_signal_interrupt();
+ /* test if cleanup is correct if a child gets killed while being blocked in F_SETLKW */
+ do_test_kill();
+
+ close(fd);
+
+ return 0;
+}
diff --git a/tests/generic/732 b/tests/generic/732
new file mode 100755
index 00000000..d77f9fc2
--- /dev/null
+++ b/tests/generic/732
@@ -0,0 +1,32 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2023 Alexander Aring. All Rights Reserved.
+#
+# FS QA Test 732
+#
+# This tests performs some fcntl() corner cases. See fcntl test
+# program for more details.
+#
+. ./common/preamble
+_begin_fstest auto
+
+# Import common functions.
+. ./common/filter
+
+# real QA test starts here
+
+# Modify as appropriate.
+_supported_fs generic
+_require_test
+_require_test_program fcntl
+
+echo "Silence is golden"
+
+$here/src/fcntl $TEST_DIR/testfile
+if [ $? -ne 0 ]
+then
+ exit
+fi
+
+status=0
+exit
diff --git a/tests/generic/732.out b/tests/generic/732.out
new file mode 100644
index 00000000..451f82ce
--- /dev/null
+++ b/tests/generic/732.out
@@ -0,0 +1,2 @@
+QA output created by 732
+Silence is golden
--
2.31.1
