Bug 12869

I found a problem with ffs:

Script started on Sat Jul 24 18:39:38 1999
bastion# kermit
C-Kermit 6.0.192, 6 Sep 96, for FreeBSD

 Copyright (C) 1985, 1996,
  Trustees of Columbia University in the City of New York.
Default file-transfer mode is TEXT
Type ? or HELP for help.
[/usr/tmp] C-Kermit>connect
Connecting to /dev/cuaa1, speed 9600.
The escape character is Ctrl-V (ASCII 22, SYN)
Type the escape character followed by C to get back,
or followed by ? to see other options.
data=0x266d4+0x20764 syms=[0x4+0x279f0+0x4+0x2a357

Hit [Enter] to boot immediately, or any other key for command prompt.
Booting [kernel] in 9 seconds...

Type '?' for a list of commands, 'help' for more detailed help.
disk1s1a:> boot -s
Copyright (c) 1992-1999 The FreeBSD Project.
Copyright (c) 1982, 1986, 1989, 1991, 1993
 The Regents of the University of California. All rights reserved.
FreeBSD 4.0-CURRENT #0: Sat Jul 24 15:08:52 CEST 1999
    root@current.risby.dk:/usr/src/sys/compile/PHO
Timecounter "i8254"  frequency 1193182 Hz
CPU: AMD-K6(tm) 3D processor (400.91-MHz 586-class CPU)
  Origin = "AuthenticAMD"  Id = 0x58c  Stepping = 12
  Features=0x8021bf<FPU,VME,DE,PSE,TSC,MSR,MCE,CX8,PGE,MMX>
  AMD Features=0x80000800<SYSCALL,3DNow!>
real memory  = 134201344 (131056K bytes)
avail memory = 126226432 (123268K bytes)
Preloaded elf kernel "kernel" at 0xc03a4000.
K6-family MTRR support enabled (2 registers)
:
changing root device to wd0s1a
Enter full pathname of shell or RETURN for /bin/sh:
# fsck -p
/dev/rwd0s1a: FILESYSTEM CLEAN; SKIPPING CHECKS
/dev/rwd0s1a: clean, 72609 free (217 frags, 9049 blocks, 0.2%
fragmentation)
/dev/rwd0s3f: FILESYSTEM CLEAN; SKIPPING CHECKS
/dev/rwd0s3f: clean, 917227 free (299 frags, 114616 blocks, 0.0%
fragmentation)
/dev/rwd0s3a: FILESYSTEM CLEAN; SKIPPING CHECKS
/dev/rwd0s3a: clean, 435121 free (129 frags, 54374 blocks, 0.0%
fragmentation)
/dev/rwd0s3d: FILESYSTEM CLEAN; SKIPPING CHECKS
/dev/rwd0s3d: clean, 4116873 free (25633 frags, 511405 blocks, 0.6%
fragmentation)
/dev/rwd0s3g: FILESYSTEM CLEAN; SKIPPING CHECKS
/dev/rwd0s3g: clean, 281787 free (9123 frags, 34083 blocks, 1.8%
fragmentation)
/dev/rwd0s3h: FILESYSTEM CLEAN; SKIPPING CHECKS
/dev/rwd0s3h: clean, 730667 free (643 frags, 91253 blocks, 0.1%
fragmentation)
/dev/rwd0s3e: FILESYSTEM CLEAN; SKIPPING CHECKS
/dev/rwd0s3e: clean, 855529 free (193 frags, 106917 blocks, 0.0%
fragmentation)
# mount -u /
# mount /usr
# mount
/dev/wd0s1a on / (local, writes: sync 2 async 0)
/dev/wd0s3d on /usr (local, soft-updates, writes: sync 2 async 0)
# cd /usr/tmp/stress/dir
# cat dir.c
/* $Id$ */
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <errno.h>
#include <string.h>


void
error(char *op, char* arg, char* file, int line) {
 fprintf(stderr,"%s. %s. %s (%s:%d)\n",
  op, arg, sys_errlist[errno], file, line);
}

void
mkDir(char *path, int level) {
 char newPath[4096];
/* printf("mkdir(%s)\n", path);*/
 if (mkdir(path, 0770) == -1) {
  error("mkdir", path, __FILE__, __LINE__);
  exit(2);
 }
 if (level > 1) {
  sprintf(newPath,"%s/d%d", path, level-1);
  mkDir(newPath, level-1);
 }
}

void
rmDir(char *path, int level) {
 char newPath[4096];
 if (level > 1) {
  sprintf(newPath,"%s/d%d", path, level-1);
  rmDir(newPath, level-1);
 }
/* printf("rmdir(%s):%d\n", path, level);*/
 if (rmdir(path) == -1) {
  error("unlink", path, __FILE__, __LINE__);
  exit(2);
 }
}

int
main(int argc, char **argv) {
 int fd, i, levels, pid;
 char path[128];

 if (argc != 2) {
  fprintf(stderr, "Usage: %s <levels>\n", argv[0]);
  exit(1);
 }

 levels = 10;
 sscanf(argv[1], "%d", &levels);
 if (levels > 210) levels = 210;
 pid = getpid();

 umask(0);
 sprintf(path,"p%05d.d%04d", pid, levels);
 mkDir(path, levels);
 rmDir(path, levels);
 return 0;
}
# ./dir 200
# sync;sync;sync
# reboot

syncing disks... done
panic: softdep_flushfiles: looping
Debugger("panic")
Stopped at      Debugger+0x37:  movl    $0,in_Debugger
db> trace
Debugger(c02b22db) at Debugger+0x37
panic(c02ef9ef,c0ddda00,0,c9020620,c99d5e94) at panic+0x74
softdep_flushfiles(c0ddda00,2,c9020620,c0ddda00,0) at
softdep_flushfiles+0x164
ffs_unmount(c0ddda00,80000,c9020620,c0ddda00,0) at ffs_unmount+0x2d
dounmount(c0ddda00,80000,c9020620,c36cb2a0,0) at dounmount+0xa6
vfs_unmountall(c9020620,c031215c,0,0,0) at vfs_unmountall+0x46
boot(0,c99d5fa0,c02687b6,c9020620,c99d5f80) at boot+0x23f
reboot(c9020620,c99d5f80,2,0,0) at reboot+0x1c
syscall(2f,2f,2f,0,0) at syscall+0x182
Xint0x80_syscall() at Xint0x80_syscall+0x26
db>

How-To-Repeat: Run the test program, reboot.