RE: recent nfs change causes autofs regression

["Hua Zhong" <hzhong@gmail.com>]

This patch fixes the problem for me, thanks.

Is this patch changing the behavior of "sharecache" to
"try-to-share-cache-if-possible", or adding a third behavior? If the user
explicitly asks for "-o sharecache", does he get an error back if the mount
options mismatch?
 
> The best I can do given the constraints appears to be to have the
> kernel first look for a superblock that matches both the fsid and the
> user-specified mount options, and then spawn off a new superblock if
> that search fails. The attached patch does just that.
> 
> Note that this is not the same as specifying nosharecache everywhere
> since nosharecache will never attempt to match an existing superblock.
> 
> Finally, for the record: I still feel very uncomfortable about not
> being able to report the state of the client setup back to the sysadmin.
> AFAIK, the only way to do so is to stat the mountpoints, and compare
> the device ids.
> 
> Trond