>Number:         564
>Category:       kern
>Synopsis:       msdosfs is incompatible with NFS
>Confidential:   no
>Severity:       serious
>Priority:       low
>Responsible:    gnats-admin (Kernel Bug People)
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Nov  8 14:35:02 1994
>Originator:     Mike Hartman
>Organization:
Human Designed Systems, Inc.
>Release:        current
>Environment:
	
System: SunOS hdssun1 4.1.3 1 sun4m
Architecture: sun4

>Description:
	Since msdosfs does not update the modification times for directories,
	it is incompatible with NFS.  Some NFS clients cache info on
	directories and files and the file modification time is used to
	determine if the the cached info is valid.
	
>How-To-Repeat:
	When an msdosfs filesystem is NFS mounted from a Sun running
	SunOS 4.1.3, the following example shows the problem:

	sun>cd subdir1/subdir2
	sun>cd ..
	sun>mv subdir2 ..
	sun>cd ../subdir2
	sun>cd ..
	sun>pwd
	current directory is 'subdir1'.

>Fix:
	One possible solution is for msdosfs to update the file modification
	times for directories on the disk.  Would MS-DOS complain?  If so,
	the file modification times for directories' RAM entries (denodes)
	could be updated without modifying the data on the disk.
>Audit-Trail:
>Unformatted: