NetBSD master CVS tree commits

[source%NetBSD.ORG@localhost]

pk
Tue Jul  8 15:03:32 PDT 1997
Update of /cvsroot/src/sys/kern
In directory netbsd1:/var/slash-tmp/cvs-serv344

Modified Files:
        vfs_bio.c 
Log Message:
Check `b_dev' field in bdwrite() before using it as an index into bdevsw[].
`b_dev' value of NODEV happens and is normal if the buffer is on its way
to the underlying device strategy function for the first time.

Also, MFS sillily uses a major device number (255) which cannot be used
to index bdevsw[]. Check marked with XXXs.