NFS/NFSD/SUNRPC: replace generic creds with 'struct cred'.

SUNRPC has two sorts of credentials, both of which appear as
"struct rpc_cred".
There are "generic credentials" which are supplied by clients
such as NFS and passed in 'struct rpc_message' to indicate
which user should be used to authorize the request, and there
are low-level credentials such as AUTH_NULL, AUTH_UNIX, AUTH_GSS
which describe the credential to be sent over the wires.

This patch replaces all the generic credentials by 'struct cred'
pointers - the credential structure used throughout Linux.

For machine credentials, there is a special 'struct cred *' pointer
which is statically allocated and recognized where needed as
having a special meaning.  A look-up of a low-level cred will
map this to a machine credential.

Signed-off-by: NeilBrown <neilb@suse.com>
Acked-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

include/linux/nfs_fs.h

@@ -70,7 +70,7 @@ struct nfs_open_context {
 	struct nfs_lock_context lock_context;
 	fl_owner_t flock_owner;
 	struct dentry *dentry;
-	struct rpc_cred *cred;
+	const struct cred *cred;
 	struct rpc_cred *ll_cred;	/* low-level cred - use to check for expiry */
 	struct nfs4_state *state;
 	fmode_t mode;
@@ -391,7 +391,7 @@ extern void nfs_setsecurity(struct inode *inode, struct nfs_fattr *fattr,
 				struct nfs4_label *label);
 extern struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx);
 extern void put_nfs_open_context(struct nfs_open_context *ctx);
-extern struct nfs_open_context *nfs_find_open_context(struct inode *inode, struct rpc_cred *cred, fmode_t mode);
+extern struct nfs_open_context *nfs_find_open_context(struct inode *inode, const struct cred *cred, fmode_t mode);
 extern struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry, fmode_t f_mode, struct file *filp);
 extern void nfs_inode_attach_open_context(struct nfs_open_context *ctx);
 extern void nfs_file_set_open_context(struct file *filp, struct nfs_open_context *ctx);
@@ -462,7 +462,7 @@ static inline struct nfs_open_context *nfs_file_open_context(struct file *filp)
 	return filp->private_data;
 }
 
-static inline struct rpc_cred *nfs_file_cred(struct file *file)
+static inline const struct cred *nfs_file_cred(struct file *file)
 {
 	if (file != NULL) {
 		struct nfs_open_context *ctx =

include/linux/nfs_xdr.h

@@ -270,7 +270,7 @@ struct nfs4_layoutget_res {
 struct nfs4_layoutget {
 	struct nfs4_layoutget_args args;
 	struct nfs4_layoutget_res res;
-	struct rpc_cred *cred;
+	const struct cred *cred;
 	gfp_t gfp_flags;
 };
 
@@ -309,7 +309,7 @@ struct nfs4_layoutcommit_data {
 	struct rpc_task task;
 	struct nfs_fattr fattr;
 	struct list_head lseg_list;
-	struct rpc_cred *cred;
+	const struct cred *cred;
 	struct inode *inode;
 	struct nfs4_layoutcommit_args args;
 	struct nfs4_layoutcommit_res res;
@@ -334,7 +334,7 @@ struct nfs4_layoutreturn_res {
 struct nfs4_layoutreturn {
 	struct nfs4_layoutreturn_args args;
 	struct nfs4_layoutreturn_res res;
-	struct rpc_cred *cred;
+	const struct cred *cred;
 	struct nfs_client *clp;
 	struct inode *inode;
 	int rpc_status;
@@ -1469,7 +1469,7 @@ enum {
 struct nfs_io_completion;
 struct nfs_pgio_header {
 	struct inode		*inode;
-	struct rpc_cred		*cred;
+	const struct cred		*cred;
 	struct list_head	pages;
 	struct nfs_page		*req;
 	struct nfs_writeverf	verf;		/* Used for writes */
@@ -1529,7 +1529,7 @@ struct nfs_commit_info {
 struct nfs_commit_data {
 	struct rpc_task		task;
 	struct inode		*inode;
-	struct rpc_cred		*cred;
+	const struct cred		*cred;
 	struct nfs_fattr	fattr;
 	struct nfs_writeverf	verf;
 	struct list_head	pages;		/* Coalesced requests we wish to flush */
@@ -1560,7 +1560,7 @@ struct nfs_unlinkdata {
 	struct nfs_removeres res;
 	struct dentry *dentry;
 	wait_queue_head_t wq;
-	struct rpc_cred	*cred;
+	const struct cred *cred;
 	struct nfs_fattr dir_attr;
 	long timeout;
 };
@@ -1568,7 +1568,7 @@ struct nfs_unlinkdata {
 struct nfs_renamedata {
 	struct nfs_renameargs	args;
 	struct nfs_renameres	res;
-	struct rpc_cred		*cred;
+	const struct cred	*cred;
 	struct inode		*old_dir;
 	struct dentry		*old_dentry;
 	struct nfs_fattr	old_fattr;

include/linux/sunrpc/auth.h

@@ -67,7 +67,7 @@ struct rpc_cred {
 #define RPCAUTH_CRED_HASHED	2
 #define RPCAUTH_CRED_NEGATIVE	3
 
-struct rpc_cred *rpc_machine_cred(void);
+const struct cred *rpc_machine_cred(void);
 
 /*
  * Client authentication handle
@@ -196,21 +196,5 @@ struct rpc_cred *get_rpccred(struct rpc_cred *cred)
 	return NULL;
 }
 
-/**
- * get_rpccred_rcu - get a reference to a cred using rcu-protected pointer
- * @cred: cred of which to take a reference
- *
- * In some cases, we may have a pointer to a credential to which we
- * want to take a reference, but don't already have one. Because these
- * objects are freed using RCU, we can access the cr_count while its
- * on its way to destruction and only take a reference if it's not already
- * zero.
- */
-static inline struct rpc_cred *
-get_rpccred_rcu(struct rpc_cred *cred)
-{
-	return get_rpccred(cred);
-}
-
 #endif /* __KERNEL__ */
 #endif /* _LINUX_SUNRPC_AUTH_H */

include/linux/sunrpc/sched.h

@@ -26,7 +26,7 @@ struct rpc_message {
 	const struct rpc_procinfo *rpc_proc;	/* Procedure information */
 	void *			rpc_argp;	/* Arguments */
 	void *			rpc_resp;	/* Result */
-	struct rpc_cred *	rpc_cred;	/* Credentials */
+	const struct cred *	rpc_cred;	/* Credentials */
 };
 
 struct rpc_call_ops;