Re: [PATCH] Access cache forgetting mode bits

[Steve Dickson <SteveD@RedHat.com>]

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Hello,

I'm thinking there might even be a better way to cache these bits...

It seems the OS calls nfs_permission() to test each permission bit which 
in turn
causes an otw access rpc for every call (assuming the same person and same
bit is *not* asked for ) and even with Andreas patch's there are at 
least two
rpcs for one access call....

Now what if on the first access call, we get *all* of the access bits 
from the
server and cache them locally (i.e. in cache->mask). That way when 
nfs_permission()
is called again, all if the needed info is there... The attached patch 
does just that
and it really seems to cut down on the amount access rpc needed...

Thoughts?

SteveD.


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--- linux-2.4.21/fs/nfs/dir.c.diff	2003-08-28 12:13:22.000000000 -0400
+++ linux-2.4.21/fs/nfs/dir.c	2003-08-28 12:13:47.000000000 -0400
@@ -1278,7 +1278,7 @@ nfs_permission(struct inode *inode, int 
 		if (cache->cred)
 			put_rpccred(cache->cred);
 		cache->cred = cred;
-		cache->mask = mask;
+		cache->mask |= mask;
 		cache->err = error;
 		return error;
 	}