i386/53137: background fscking causing ffs_valloc panic.

[Peter Losher]

>Number:         53137
>Category:       i386
>Synopsis:       background fscking causing ffs_valloc panic.
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-i386
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Tue Jun 10 01:40:14 PDT 2003
>Closed-Date:
>Last-Modified:
>Originator:     Peter Losher
>Release:        FreeBSD 5.1-RELEASE i386
>Organization:
ISC
>Environment:
System: FreeBSD sf1.isc.org 5.1-RELEASE FreeBSD 5.1-RELEASE #0: Mon Jun 9 01:34:57 UTC 2003 root@:/usr/src/sys/i386/compile/ISC_FBSD_51_SMP i386

	
>Description:

Because of a kernel panic, this system was unable to cleanly dismount its 
local drives.  On the subequent reboot the system marked the large (230GB) data 
partition (/dev/twed0s1g = /hog) for background fscking:

-=-
Starting file system checks:
/dev/twed0s1a: UNREF FILE I=8365  OWNER=root MODE=100600
/dev/twed0s1a: SIZE=344064 MTIME=Jun  9 19:58 2003  (CLEARED)
/dev/twed0s1a: FREE BLK COUNT(S) WRONG IN SUPERBLK (SALVAGED)
/dev/twed0s1a: SUMMARY INFORMATION BAD (SALVAGED)
/dev/twed0s1a: BLK(S) MISSING IN BIT MAPS (SALVAGED)
/dev/twed0s1a: 1264 files, 47473 used, 81446 free (190 frags, 10157 blocks, 0.1%
fragmentation)
/dev/twed0s1g: DEFER FOR BACKGROUND CHECKING
/dev/twed0s1d: DEFER FOR BACKGROUND CHECKING
/dev/twed0s1e: DEFER FOR BACKGROUND CHECKING

/dev/twed0s1f: UNREF FILE I=2619949  OWNER=news MODE=100644
/dev/twed0s1f: SIZE=134523 MTIME=Jun  9 02:00 2003  (CLEARED)
/dev/twed0s1f: FREE BLK COUNT(S) WRONG IN SUPERBLK (SALVAGED)
/dev/twed0s1f: SUMMARY INFORMATION BAD (SALVAGED)
/dev/twed0s1f: BLK(S) MISSING IN BIT MAPS (SALVAGED)
/dev/twed0s1f: 844287 files, 3452688 used, 21113556 free (259396 frags, 2606770
blocks, 1.1% fragmentation)
WARNING: /hog was not properly dismounted
/hog: mount pending error: blocks 12816 files 5
/hog: superblock summary recomputed
WARNING: /usr was not properly dismounted
WARNING: /var was not properly dismounted
/var: superblock summary recomputed
-=-

After starting the background fsck'ing it panics:

-=-
Starting background file system checks.

Mon Jun  9 21:00:29 UTC 2003
mode = 041777, inum = 4, fs = /hog
panic: ffs_valloc: dup alloc
cpuid = 0; lapic.id = 00000000
boot() called on cpu#0
-=-

>How-To-Repeat:

No reliable way to reproduce the problem; perhaps do a big write on a large 
partition, cut the power (thus not properly sync'ing the disks) and try a 
background fsck upon reboot.

>Fix:

You either have to go into single-user mode and manually fsck the partition,
or turn off background fscking in /etc/rc.conf (background_fsck="NO").
>Release-Note:
>Audit-Trail:
>Unformatted: