kern/43576: pathconf(2) FILESIZEBITS bad value on tmpfs

[njoly%pasteur.fr@localhost]

>Number:         43576
>Category:       kern
>Synopsis:       pathconf(2) FILESIZEBITS bad value on tmpfs
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Jul 06 11:50:00 +0000 2010
>Originator:     Nicolas Joly
>Release:        NetBSD 5.99.34
>Organization:
Institut Pasteur
>Environment:
System: NetBSD lanfeust.sis.pasteur.fr 5.99.34 NetBSD 5.99.34 (LANFEUST) #7: 
Tue Jul 6 12:12:47 CEST 2010 
njoly%lanfeust.sis.pasteur.fr@localhost:/local/src/NetBSD/obj.amd64/sys/arch/amd64/compile/LANFEUST
 amd64
Architecture: x86_64
Machine: amd64
>Description:
pathconf(2) FILESIZEBITS value is incorrect for tmpfs mounts.

njoly@lanfeust [~]> df -h /tmp               
Filesystem        Size       Used      Avail %Cap Mounted on
tmpfs              12G        20K        12G   0% /tmp
njoly@lanfeust [~]> getconf -a /tmp          
LINK_MAX = 32767
NAME_MAX = 255
PATH_MAX = 1024
PIPE_BUF = 512
_POSIX_CHOWN_RESTRICTED = 1
_POSIX_NO_TRUNC = 1
_POSIX_SYNC_IO = 1
FILESIZEBITS = 0

According to the opengroup document, it should be at least 32:

http://www.opengroup.org/onlinepubs/009695399/basedefs/limits.h.html
[...]
{FILESIZEBITS}
    Minimum number of bits needed to represent, as a signed integer value, the 
maximum size of a regular file allowed in the specified directory.
    Minimum Acceptable Value: 32

>How-To-Repeat:
Use getconf -a on a tmpfs mount
>Fix: