Defining PATH_MAX for a filesystem?

Question

I\'m presently writing a filesystem. The statvfs (and even the statfs) structs contain a field specifying the maximum length of a name in that path. As PATH_M

Answer 1

I do not enough about other OSes but imho this is a system-wide setting in at least FreeBSD 5.2.1

PATH_MAX is found in #62 sys/syslimits.h

Because static int ufs_pathconf() which returns the PATHCONF information for UFS FS, uses this variable in the manner you specified.

/*
 * Return POSIX pathconf information applicable to ufs filesystems.
 */
int
ufs_pathconf(ap)
    struct vop_pathconf_args /* {
        struct vnode *a_vp;
        int a_name;
        int *a_retval;
    } */ *ap;
{

    switch (ap->a_name) {
    .
    .
    .
    .
    case _PC_PATH_MAX:
        *ap->a_retval = PATH_MAX;
        return (0);
    .
    .
    .
    .

    default:
        return (EINVAL);
    }
    /* NOTREACHED */
}