#!/bin/sh # # Copyright (c) 2011 Peter Holm # All rights reserved. # # Redistribution and use in source and binary forms, with or without # modification, are permitted provided that the following conditions # are met: # 1. Redistributions of source code must retain the above copyright # notice, this list of conditions and the following disclaimer. # 2. Redistributions in binary form must reproduce the above copyright # notice, this list of conditions and the following disclaimer in the # documentation and/or other materials provided with the distribution. # # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE # ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF # SUCH DAMAGE. # [ `id -u ` -ne 0 ] && echo "Must be root!" && exit 1 # Demonstrate rename(2) cache problem for tmpfs(5). Fixed in r226987. # Variation of rename6.sh . ../default.cfg here=`pwd` cd /tmp sed '1,/^EOF/d' < $here/$0 > tmpfs8.c mycc -o tmpfs8 -Wall -Wextra -O2 tmpfs8.c rm -f tmpfs8.c cd $here mount | grep $mntpoint | grep -q tmpfs && umount -f $mntpoint mount -t tmpfs tmpfs $mntpoint chmod 777 $mntpoint su $testuser -c "cd $mntpoint; /tmp/tmpfs8" while mount | grep $mntpoint | grep -q tmpfs; do umount $mntpoint || sleep 1 done rm -f /tmp/tmpfs8 exit EOF #include #include #include #include #include #include #include #include #include #include #include #include #include #include pid_t spid; const char *logfile = "test.log"; char new[128]; void cleanup() { kill(spid, SIGINT); } static void Stat() { struct stat sb; int i; setproctitle("Stat"); for (;;) { for (i = 0; i < 1000; i++) { stat(logfile, &sb); stat(new, &sb); } // usleep(1000); usleep(100); } } int main(void) { struct stat sb1, sb2, sb3; int fd, i, r1, r2, r3; if ((spid = fork()) == 0) Stat(); setproctitle("main"); atexit(cleanup); for (i = 0; i < 200000; i++) { bzero(&sb1, sizeof(sb1)); bzero(&sb2, sizeof(sb2)); if ((fd = open(logfile, O_RDWR | O_CREAT | O_TRUNC, 0644)) == -1) err(1, "creat(%s)", logfile); close(fd); sprintf(new, "test.log.%05d", i); if ((fd = open(new, O_RDWR | O_CREAT | O_TRUNC, 0644)) == -1) err(1, "creat(%s)", new); write(fd, "xxx", 3); close(fd); if ((r3 = stat(new, &sb3)) == -1) err(1, "stat(%s)", new); #if 1 if (rename(logfile, new) == -1) warn("rename(%s, %s)", logfile, new); #else /* No cache problem is seen */ if (link(logfile, new) == -1) err(1, "link(%s, %s)", logfile, new); if (unlink(logfile) == -1) err(1, "unlink(%s)", logfile); #endif /* * stat() for logfile and new will be identical sometimes, * but only when Stat() is running. */ r1 = stat(logfile, &sb1); r2 = stat(new, &sb2); if (r1 == 0 && r2 == 0 && bcmp(&sb1, &sb2, sizeof(sb1)) == 0) { fprintf(stderr, "FAIL 1\n"); fprintf(stderr, "%-15s: ino = %4ju, nlink = %ju, " "size = %jd\n", logfile, (uintmax_t)sb1.st_ino, (uintmax_t)sb1.st_nlink, sb1.st_blocks); fprintf(stderr, "%-15s: ino = %4ju, nlink = %ju, " "size = %jd\n", new , (uintmax_t)sb2.st_ino, (uintmax_t)sb2.st_nlink, sb2.st_blocks); } if (bcmp(&sb2, &sb3, sizeof(sb2)) == 0) { fprintf(stderr, "Old to file is lingering\n"); } if (sb2.st_ino == sb3.st_ino) { fprintf(stderr, "FAIL 2\n"); if (r1 == 0) fprintf(stderr, "sb1: %-15s: ino = %4ju, nlink = %ju, " "size = %jd\n", logfile, (uintmax_t)sb1.st_ino, (uintmax_t)sb1.st_nlink, sb1.st_blocks); if (r2 == 0) fprintf(stderr, "sb2: %-15s: ino = %4ju, nlink = %ju, " "size = %jd\n", new, (uintmax_t)sb2.st_ino, (uintmax_t)sb2.st_nlink, sb2.st_blocks); if (r3 == 0) fprintf(stderr, "sb3: %-15s: ino = %4ju, nlink = %ju, " "size = %jd\n", new, (uintmax_t)sb3.st_ino, (uintmax_t)sb3.st_nlink, sb3.st_blocks); exit(1); } unlink(new); } kill(spid, SIGINT); wait(NULL); return (0); }