kern/76234: System cannot guess NFS client module name to autoload it

[Yar Tikhiy]

>Number:         76234
>Category:       kern
>Synopsis:       System cannot guess NFS client module name to autoload it
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Fri Jan 14 03:50:24 GMT 2005
>Closed-Date:
>Last-Modified:
>Originator:     Yar Tikhiy
>Release:        FreeBSD 6.0-CURRENT i386
>Organization:
Moscow State University
>Environment:
System: FreeBSD stylish.chem.msu.su 6.0-CURRENT FreeBSD 6.0-CURRENT #0: Mon Jan 10 21:00:34 MSK 2005 yar at stylish.chem.msu.su:/usr/obj/usr/src/sys/STYLISH i386


>Description:
	The mount(2) syscall handler will attempt autoloading the file system
	module if the file system type to mount isn't there.  To do that, it
	assumes that the file system "foofs" is handled by the module "foofs.ko".
	Therefore it cannot guess the NFS client module name since it's
	"nfsclient.ko", not "nfs.ko".

>How-To-Repeat:

stylish# grep ports /etc/fstab
bsd:/usr/ports          /usr/ports      nfs     ro,noauto       0       0
stylish# ktrace -i mount /usr/ports
nfs: /usr/ports: No such file or directory
stylish# kdump
...
   917 mount_nfs CALL  mount(0x804b15b,0xbfbfe3a4,0x1,0xbfbfe7a4)
   917 mount_nfs NAMI  "/boot/kernel/linker.hints"
   917 mount_nfs NAMI  "/boot/kernel/nfs"
   917 mount_nfs NAMI  "/boot/kernel/nfs.ko"
   917 mount_nfs NAMI  "/boot/modules/linker.hints"
   917 mount_nfs NAMI  "/boot/modules/nfs"
   917 mount_nfs NAMI  "/boot/modules/nfs.ko"
   917 mount_nfs RET   mount -1 errno 2 No such file or directory

>Fix:
	It would be ugly to hardcode this special case in the mount(2)
	handler, a symlink nfs.ko -> nfsclient.ko would be a better solution.
>Release-Note:
>Audit-Trail:
>Unformatted: