tree 77a864ab5538255dfba454d13f67de60807f2973
parent 9b8b317d58084b9a44f6f33b355c4278d9f841fb
author J. Bruce Fields <bfields@citi.umich.edu> 1259188925 -0500
committer J. Bruce Fields <bfields@citi.umich.edu> 1259189746 -0500

nfsd: simplify fh_verify access checks

All nfsd security depends on the security checks in fh_verify, and
especially on nfsd_setuser().

It therefore bothers me that the nfsd_setuser call may be made from
three different places, depending on whether the filehandle has already
been mapped to a dentry, and on whether subtreechecking is in force.

Instead, make an unconditional call in fh_verify(), so it's trivial to
verify that the call always occurs.

That leaves us with a redundant nfsd_setuser() call in the subtreecheck
case--it needs the correct user set earlier in order to check execute
permissions on the path to this filehandle--but I'm willing to accept
that minor inefficiency in the subtreecheck case in return for more
straightforward permission checking.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>