NFS: change access cache to use 'struct cred'.

Rather than keying the access cache with 'struct rpc_cred',
use 'struct cred'.  Then use cred_fscmp() to compare
credentials rather than comparing the raw pointer.

A benefit of this approach is that in the common case we avoid the
rpc_lookup_cred_nonblock() call which can be slow when the cred cache is large.
This also keeps many fewer items pinned in the rpc cred cache, so the
cred cache is less likely to get large.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

1 files changed, 8 insertions, 1 deletions

diff --git a/fs/nfs/nfs3proc.c b/fs/nfs/nfs3proc.c
index 71bc16225b98..f7174f3a9575 100644
--- a/fs/nfs/nfs3proc.c
+++ b/fs/nfs/nfs3proc.c
@@ -195,15 +195,20 @@ static int nfs3_proc_access(struct inode *inode, struct nfs_access_entry *entry)
 		.access		= entry->mask,
 	};
 	struct nfs3_accessres	res;
+	struct auth_cred acred = {
+		.cred		= entry->cred,
+	};
 	struct rpc_message msg = {
 		.rpc_proc	= &nfs3_procedures[NFS3PROC_ACCESS],
 		.rpc_argp	= &arg,
 		.rpc_resp	= &res,
-		.rpc_cred	= entry->cred,
+		.rpc_cred	= rpc_lookup_generic_cred(&acred, 0, GFP_NOFS),
 	};
 	int status = -ENOMEM;
 
 	dprintk("NFS call  access\n");
+	if (!msg.rpc_cred)
+		goto out;
 	res.fattr = nfs_alloc_fattr();
 	if (res.fattr == NULL)
 		goto out;
@@ -214,6 +219,8 @@ static int nfs3_proc_access(struct inode *inode, struct nfs_access_entry *entry)
 		nfs_access_set_mask(entry, res.access);
 	nfs_free_fattr(res.fattr);
 out:
+	if (msg.rpc_cred)
+		put_rpccred(msg.rpc_cred);
 	dprintk("NFS reply access: %d\n", status);
 	return status;
 }