1#!/bin/sh 2 3# 4# Copyright (c) 2014 EMC Corp. 5# All rights reserved. 6# 7# Redistribution and use in source and binary forms, with or without 8# modification, are permitted provided that the following conditions 9# are met: 10# 1. Redistributions of source code must retain the above copyright 11# notice, this list of conditions and the following disclaimer. 12# 2. Redistributions in binary form must reproduce the above copyright 13# notice, this list of conditions and the following disclaimer in the 14# documentation and/or other materials provided with the distribution. 15# 16# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26# SUCH DAMAGE. 27# 28 29# The issue makes it possible for applications to get wrong EINTR 30# or ERESTART (the later is not directly visible) when doing write 31# to the file on suspended UFS volume. I.e. the thread is sleeping 32# when fs is suspended, and process is signaled. 33 34# Test scenario mostly by kib. 35# Fixed in r275744. 36 37# Deadlock seen: 38# https://people.freebsd.org/~pho/stress/log/pcatch.txt 39 40[ `id -u ` -ne 0 ] && echo "Must be root!" && exit 1 41[ -z "$DEBUG" ] && exit 0 # Waiting for fix 42 43. ../default.cfg 44 45here=`pwd` 46cd /tmp 47sed '1,/^EOF/d' < $here/$0 > pcatch.c 48mycc -o pcatch -Wall -Wextra -O0 -g pcatch.c || exit 1 49rm -f pcatch.c 50cd $here 51 52mount | grep -q "$mntpoint" && umount $mntpoint 53mdconfig -l | grep -q $mdstart && mdconfig -d -u $mdstart 54mdconfig -a -t swap -s 1g -u $mdstart 55newfs $newfs_flags md$mdstart > /dev/null 56 57mount /dev/md$mdstart $mntpoint 58 59start=`date '+%s'` 60while [ $((`date '+%s'` - start)) -lt 120 ]; do 61 /tmp/pcatch $mntpoint 62done 63 64while mount | grep -q "on $mntpoint "; do 65 umount $mntpoint || sleep 1 66done 67mdconfig -d -u $mdstart 68rm -f /tmp/pcatch 69exit 0 70EOF 71#include <sys/types.h> 72#include <sys/ioctl.h> 73#include <sys/mount.h> 74#include <sys/wait.h> 75 76#include <ufs/ffs/fs.h> 77 78#include <err.h> 79#include <errno.h> 80#include <fcntl.h> 81#include <signal.h> 82#include <stdio.h> 83#include <stdlib.h> 84#include <string.h> 85#include <unistd.h> 86 87static void 88hand_sigaction(int signo __unused, siginfo_t *si __unused, void *c __unused) 89{ 90} 91 92static void 93suspend(char *path) 94{ 95 struct statfs s; 96 int fd, error; 97 98 if (fork() == 0) { 99 if ((error = statfs(path, &s)) != 0) 100 err(1, "statfs %s", path); 101 fd = open("/dev/ufssuspend", O_RDWR); 102 if ((error = ioctl(fd, UFSSUSPEND, &s.f_fsid)) != 0) 103 err(1, "UFSSUSPEND"); 104 sleep(1); 105 if ((error = ioctl(fd, UFSRESUME, &s.f_fsid)) != 0) 106 err(1, "UFSRESUME"); 107 _exit(0); 108 } 109} 110 111static void 112test(char *mp) 113{ 114 pid_t pid; 115 struct sigaction sa; 116 int fd; 117 char buf[80], file[80]; 118 119 memset(&sa, 0, sizeof(sa)); 120 sa.sa_sigaction = hand_sigaction; 121 if (sigaction(SIGUSR1, &sa, NULL) == -1) 122 err(1, "sigaction"); 123 124 snprintf(file, sizeof(file), "%s/file", mp); 125 if ((fd = open(file, O_RDWR | O_CREAT | O_TRUNC, 0640)) == -1) 126 err(1, "open(%s). %s:%d", file, __FILE__, __LINE__); 127 128 suspend(mp); 129 130 if ((pid = fork()) == 0) { 131 if (write(fd, buf, sizeof(buf)) == -1) 132 warn("FAIL: write"); 133 _exit(0); 134 } 135 usleep(10000); 136 if (kill(pid, SIGUSR1) == -1) 137 err(1, "kill"); 138 wait(NULL); 139 wait(NULL); 140 close(fd); 141} 142 143int 144main(int argc, char *argv[]) 145{ 146 147 if (argc != 2) 148 errx(1, "Usage: %s <UFS mount point>", argv[0]); 149 150 test(argv[1]); 151 152 return (0); 153} 154