bin/94810: fsck incorrectly reports 'file system marked clean' when lost+found fills up

[Kris Kennaway]

>Number:         94810
>Category:       bin
>Synopsis:       fsck incorrectly reports 'file system marked clean' when lost+found fills up
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Tue Mar 21 21:50:16 GMT 2006
>Closed-Date:
>Last-Modified:
>Originator:     Kris Kennaway
>Release:        FreeBSD 6.1-PRERELEASE i386
>Organization:
FreeBSD
>Environment:
System: FreeBSD xor.obsecurity.org 6.1-PRERELEASE FreeBSD 6.1-PRERELEASE #18: Mon Mar 13 01:39:05 EST 2006 kkenn at xor.obsecurity.org:/mnt/src/sys/i386/compile/XOR i386

>Description:

In cases of severe filesystem damage, fsck may fill up lost+found:

[...]
SORRY. NO SPACE IN lost+found DIRECTORY
UNEXPECTED SOFT UPDATE INCONSISTENCY


UNREF DIR  I=871505  OWNER=root MODE=40770
SIZE=512 MTIME=Jan  1 09:59 1970
RECONNECT? yes

SORRY. NO SPACE IN lost+found DIRECTORY
UNEXPECTED SOFT UPDATE INCONSISTENCY
[...]

However, when fsck eventually completes it reports

***** FILE SYSTEM MARKED CLEAN *****
***** FILE SYSTEM WAS MODIFIED *****

In fact, all of the damage was not repaired since the extra files
could not be reconnected to lost+found, so it is necessary to:

1) mount and clean out lost+found or move it aside

2) unmount and rerun fsck to continue recovering lost files.

3) Repeat until all files have been recovered (may take multiple
iterations)

>How-To-Repeat:
>Fix:

The admin should be informed that due to lost+found filling up,
further action is required as above.

Even if the filesystem is being marked clean to facilitate the admin
mounting it, for the purposes of making additional space in lost+found
(this isn't strictly necessary since you can mount -f a dirty fs), the
admin should be informed that the filesystem damage is not yet
repaired.
>Release-Note:
>Audit-Trail:
>Unformatted: