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>

Author: NeilBrown

fs/lockd/clntproc.c

@@ -256,7 +256,7 @@ static int nlm_wait_on_grace(wait_queue_head_t *queue)
  * Generic NLM call
  */
 static int
-nlmclnt_call(struct rpc_cred *cred, struct nlm_rqst *req, u32 proc)
+nlmclnt_call(const struct cred *cred, struct nlm_rqst *req, u32 proc)
 {
 	struct nlm_host	*host = req->a_host;
 	struct rpc_clnt	*clnt;
@@ -401,7 +401,7 @@ int nlm_async_reply(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *t
  *      completion in order to be able to correctly track the lock
  *      state.
  */
-static int nlmclnt_async_call(struct rpc_cred *cred, struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops)
+static int nlmclnt_async_call(const struct cred *cred, struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops)
 {
 	struct rpc_message msg = {
 		.rpc_argp	= &req->a_args,
@@ -510,7 +510,7 @@ static int do_vfs_lock(struct file_lock *fl)
 static int
 nlmclnt_lock(struct nlm_rqst *req, struct file_lock *fl)
 {
-	struct rpc_cred *cred = nfs_file_cred(fl->fl_file);
+	const struct cred *cred = nfs_file_cred(fl->fl_file);
 	struct nlm_host	*host = req->a_host;
 	struct nlm_res	*resp = &req->a_res;
 	struct nlm_wait *block = NULL;

fs/nfs/blocklayout/blocklayout.c

@@ -584,7 +584,7 @@ static int decode_sector_number(__be32 **rp, sector_t *sp)
 
 static struct nfs4_deviceid_node *
 bl_find_get_deviceid(struct nfs_server *server,
-		const struct nfs4_deviceid *id, struct rpc_cred *cred,
+		const struct nfs4_deviceid *id, const struct cred *cred,
 		gfp_t gfp_mask)
 {
 	struct nfs4_deviceid_node *node;

fs/nfs/delegation.c

@@ -26,10 +26,8 @@
 
 static void nfs_free_delegation(struct nfs_delegation *delegation)
 {
-	if (delegation->cred) {
-		put_rpccred(delegation->cred);
-		delegation->cred = NULL;
-	}
+	put_cred(delegation->cred);
+	delegation->cred = NULL;
 	kfree_rcu(delegation, rcu);
 }
 
@@ -178,13 +176,13 @@ static int nfs_delegation_claim_opens(struct inode *inode,
  * @pagemod_limit: write delegation "space_limit"
  *
  */
-void nfs_inode_reclaim_delegation(struct inode *inode, struct rpc_cred *cred,
+void nfs_inode_reclaim_delegation(struct inode *inode, const struct cred *cred,
 				  fmode_t type,
 				  const nfs4_stateid *stateid,
 				  unsigned long pagemod_limit)
 {
 	struct nfs_delegation *delegation;
-	struct rpc_cred *oldcred = NULL;
+	const struct cred *oldcred = NULL;
 
 	rcu_read_lock();
 	delegation = rcu_dereference(NFS_I(inode)->delegation);
@@ -195,12 +193,12 @@ void nfs_inode_reclaim_delegation(struct inode *inode, struct rpc_cred *cred,
 			delegation->type = type;
 			delegation->pagemod_limit = pagemod_limit;
 			oldcred = delegation->cred;
-			delegation->cred = get_rpccred(cred);
+			delegation->cred = get_cred(cred);
 			clear_bit(NFS_DELEGATION_NEED_RECLAIM,
 				  &delegation->flags);
 			spin_unlock(&delegation->lock);
 			rcu_read_unlock();
-			put_rpccred(oldcred);
+			put_cred(oldcred);
 			trace_nfs4_reclaim_delegation(inode, type);
 			return;
 		}
@@ -341,7 +339,7 @@ nfs_update_inplace_delegation(struct nfs_delegation *delegation,
  *
  * Returns zero on success, or a negative errno value.
  */
-int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred,
+int nfs_inode_set_delegation(struct inode *inode, const struct cred *cred,
 				  fmode_t type,
 				  const nfs4_stateid *stateid,
 				  unsigned long pagemod_limit)
@@ -360,7 +358,7 @@ int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred,
 	delegation->type = type;
 	delegation->pagemod_limit = pagemod_limit;
 	delegation->change_attr = inode_peek_iversion_raw(inode);
-	delegation->cred = get_rpccred(cred);
+	delegation->cred = get_cred(cred);
 	delegation->inode = inode;
 	delegation->flags = 1<<NFS_DELEGATION_REFERENCED;
 	spin_lock_init(&delegation->lock);
@@ -1047,7 +1045,7 @@ void nfs_reap_expired_delegations(struct nfs_client *clp)
 	struct nfs_delegation *delegation;
 	struct nfs_server *server;
 	struct inode *inode;
-	struct rpc_cred *cred;
+	const struct cred *cred;
 	nfs4_stateid stateid;
 
 restart:
@@ -1069,7 +1067,7 @@ void nfs_reap_expired_delegations(struct nfs_client *clp)
 				nfs_sb_deactive(server->super);
 				goto restart;
 			}
-			cred = get_rpccred_rcu(delegation->cred);
+			cred = get_cred_rcu(delegation->cred);
 			nfs4_stateid_copy(&stateid, &delegation->stateid);
 			clear_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags);
 			rcu_read_unlock();
@@ -1078,7 +1076,7 @@ void nfs_reap_expired_delegations(struct nfs_client *clp)
 				nfs_revoke_delegation(inode, &stateid);
 				nfs_inode_find_state_and_recover(inode, &stateid);
 			}
-			put_rpccred(cred);
+			put_cred(cred);
 			if (nfs4_server_rebooted(clp)) {
 				nfs_inode_mark_test_expired_delegation(server,inode);
 				iput(inode);
@@ -1173,7 +1171,7 @@ bool nfs4_refresh_delegation_stateid(nfs4_stateid *dst, struct inode *inode)
  * otherwise "false" is returned.
  */
 bool nfs4_copy_delegation_stateid(struct inode *inode, fmode_t flags,
-		nfs4_stateid *dst, struct rpc_cred **cred)
+		nfs4_stateid *dst, const struct cred **cred)
 {
 	struct nfs_inode *nfsi = NFS_I(inode);
 	struct nfs_delegation *delegation;
@@ -1187,7 +1185,7 @@ bool nfs4_copy_delegation_stateid(struct inode *inode, fmode_t flags,
 		nfs4_stateid_copy(dst, &delegation->stateid);
 		nfs_mark_delegation_referenced(delegation);
 		if (cred)
-			*cred = get_rpccred(delegation->cred);
+			*cred = get_cred(delegation->cred);
 	}
 	rcu_read_unlock();
 	return ret;

fs/nfs/delegation.h

@@ -15,7 +15,7 @@
  */
 struct nfs_delegation {
 	struct list_head super_list;
-	struct rpc_cred *cred;
+	const struct cred *cred;
 	struct inode *inode;
 	nfs4_stateid stateid;
 	fmode_t type;
@@ -36,9 +36,9 @@ enum {
 	NFS_DELEGATION_TEST_EXPIRED,
 };
 
-int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred,
+int nfs_inode_set_delegation(struct inode *inode, const struct cred *cred,
 		fmode_t type, const nfs4_stateid *stateid, unsigned long pagemod_limit);
-void nfs_inode_reclaim_delegation(struct inode *inode, struct rpc_cred *cred,
+void nfs_inode_reclaim_delegation(struct inode *inode, const struct cred *cred,
 		fmode_t type, const nfs4_stateid *stateid, unsigned long pagemod_limit);
 int nfs4_inode_return_delegation(struct inode *inode);
 int nfs_async_inode_return_delegation(struct inode *inode, const nfs4_stateid *stateid);
@@ -60,10 +60,10 @@ void nfs_mark_test_expired_all_delegations(struct nfs_client *clp);
 void nfs_reap_expired_delegations(struct nfs_client *clp);
 
 /* NFSv4 delegation-related procedures */
-int nfs4_proc_delegreturn(struct inode *inode, struct rpc_cred *cred, const nfs4_stateid *stateid, int issync);
+int nfs4_proc_delegreturn(struct inode *inode, const struct cred *cred, const nfs4_stateid *stateid, int issync);
 int nfs4_open_delegation_recall(struct nfs_open_context *ctx, struct nfs4_state *state, const nfs4_stateid *stateid, fmode_t type);
 int nfs4_lock_delegation_recall(struct file_lock *fl, struct nfs4_state *state, const nfs4_stateid *stateid);
-bool nfs4_copy_delegation_stateid(struct inode *inode, fmode_t flags, nfs4_stateid *dst, struct rpc_cred **cred);
+bool nfs4_copy_delegation_stateid(struct inode *inode, fmode_t flags, nfs4_stateid *dst, const struct cred **cred);
 bool nfs4_refresh_delegation_stateid(nfs4_stateid *dst, struct inode *inode);
 
 void nfs_mark_delegation_referenced(struct nfs_delegation *delegation);

fs/nfs/flexfilelayout/flexfilelayout.c

@@ -224,16 +224,14 @@ static struct nfs4_ff_layout_mirror *ff_layout_alloc_mirror(gfp_t gfp_flags)
 
 static void ff_layout_free_mirror(struct nfs4_ff_layout_mirror *mirror)
 {
-	struct rpc_cred	*cred;
+	const struct cred	*cred;
 
 	ff_layout_remove_mirror(mirror);
 	kfree(mirror->fh_versions);
 	cred = rcu_access_pointer(mirror->ro_cred);
-	if (cred)
-		put_rpccred(cred);
+	put_cred(cred);
 	cred = rcu_access_pointer(mirror->rw_cred);
-	if (cred)
-		put_rpccred(cred);
+	put_cred(cred);
 	nfs4_ff_layout_put_deviceid(mirror->mirror_ds);
 	kfree(mirror);
 }
@@ -411,9 +409,8 @@ ff_layout_alloc_lseg(struct pnfs_layout_hdr *lh,
 
 	for (i = 0; i < fls->mirror_array_cnt; i++) {
 		struct nfs4_ff_layout_mirror *mirror;
-		struct auth_cred acred = {};
-		struct rpc_cred	__rcu *cred;
 		struct cred *kcred;
+		const struct cred *cred;
 		kuid_t uid;
 		kgid_t gid;
 		u32 ds_count, fh_count, id;
@@ -504,15 +501,7 @@ ff_layout_alloc_lseg(struct pnfs_layout_hdr *lh,
 			goto out_err_free;
 		kcred->fsuid = uid;
 		kcred->fsgid = gid;
-		acred.cred = kcred;
-
-		/* find the cred for it */
-		rcu_assign_pointer(cred, rpc_lookup_generic_cred(&acred, 0, gfp_flags));
-		put_cred(kcred);
-		if (IS_ERR(cred)) {
-			rc = PTR_ERR(cred);
-			goto out_err_free;
-		}
+		cred = kcred;
 
 		if (lgr->range.iomode == IOMODE_READ)
 			rcu_assign_pointer(fls->mirror_array[i]->ro_cred, cred);
@@ -1714,7 +1703,7 @@ ff_layout_read_pagelist(struct nfs_pgio_header *hdr)
 	struct pnfs_layout_segment *lseg = hdr->lseg;
 	struct nfs4_pnfs_ds *ds;
 	struct rpc_clnt *ds_clnt;
-	struct rpc_cred *ds_cred;
+	const struct cred *ds_cred;
 	loff_t offset = hdr->args.offset;
 	u32 idx = hdr->pgio_mirror_idx;
 	int vers;
@@ -1765,7 +1754,7 @@ ff_layout_read_pagelist(struct nfs_pgio_header *hdr)
 			  vers == 3 ? &ff_layout_read_call_ops_v3 :
 				      &ff_layout_read_call_ops_v4,
 			  0, RPC_TASK_SOFTCONN);
-	put_rpccred(ds_cred);
+	put_cred(ds_cred);
 	return PNFS_ATTEMPTED;
 
 out_failed:
@@ -1781,7 +1770,7 @@ ff_layout_write_pagelist(struct nfs_pgio_header *hdr, int sync)
 	struct pnfs_layout_segment *lseg = hdr->lseg;
 	struct nfs4_pnfs_ds *ds;
 	struct rpc_clnt *ds_clnt;
-	struct rpc_cred *ds_cred;
+	const struct cred *ds_cred;
 	loff_t offset = hdr->args.offset;
 	int vers;
 	struct nfs_fh *fh;
@@ -1830,7 +1819,7 @@ ff_layout_write_pagelist(struct nfs_pgio_header *hdr, int sync)
 			  vers == 3 ? &ff_layout_write_call_ops_v3 :
 				      &ff_layout_write_call_ops_v4,
 			  sync, RPC_TASK_SOFTCONN);
-	put_rpccred(ds_cred);
+	put_cred(ds_cred);
 	return PNFS_ATTEMPTED;
 
 out_failed:
@@ -1860,7 +1849,7 @@ static int ff_layout_initiate_commit(struct nfs_commit_data *data, int how)
 	struct pnfs_layout_segment *lseg = data->lseg;
 	struct nfs4_pnfs_ds *ds;
 	struct rpc_clnt *ds_clnt;
-	struct rpc_cred *ds_cred;
+	const struct cred *ds_cred;
 	u32 idx;
 	int vers, ret;
 	struct nfs_fh *fh;
@@ -1900,7 +1889,7 @@ static int ff_layout_initiate_commit(struct nfs_commit_data *data, int how)
 				   vers == 3 ? &ff_layout_commit_call_ops_v3 :
 					       &ff_layout_commit_call_ops_v4,
 				   how, RPC_TASK_SOFTCONN);
-	put_rpccred(ds_cred);
+	put_cred(ds_cred);
 	return ret;
 out_err:
 	pnfs_generic_prepare_to_resend_writes(data);

fs/nfs/flexfilelayout/flexfilelayout.h

@@ -81,8 +81,8 @@ struct nfs4_ff_layout_mirror {
 	u32				fh_versions_cnt;
 	struct nfs_fh			*fh_versions;
 	nfs4_stateid			stateid;
-	struct rpc_cred	__rcu		*ro_cred;
-	struct rpc_cred	__rcu		*rw_cred;
+	const struct cred __rcu		*ro_cred;
+	const struct cred __rcu		*rw_cred;
 	refcount_t			ref;
 	spinlock_t			lock;
 	unsigned long			flags;
@@ -229,8 +229,8 @@ nfs4_ff_find_or_create_ds_client(struct pnfs_layout_segment *lseg,
 				 u32 ds_idx,
 				 struct nfs_client *ds_clp,
 				 struct inode *inode);
-struct rpc_cred *ff_layout_get_ds_cred(struct pnfs_layout_segment *lseg,
-				       u32 ds_idx, struct rpc_cred *mdscred);
+const struct cred *ff_layout_get_ds_cred(struct pnfs_layout_segment *lseg,
+				       u32 ds_idx, const struct cred *mdscred);
 bool ff_layout_avoid_mds_available_ds(struct pnfs_layout_segment *lseg);
 bool ff_layout_avoid_read_on_rw(struct pnfs_layout_segment *lseg);
 

fs/nfs/flexfilelayout/flexfilelayoutdev.c

@@ -330,10 +330,10 @@ int ff_layout_track_ds_error(struct nfs4_flexfile_layout *flo,
 	return 0;
 }
 
-static struct rpc_cred *
+static const struct cred *
 ff_layout_get_mirror_cred(struct nfs4_ff_layout_mirror *mirror, u32 iomode)
 {
-	struct rpc_cred *cred, __rcu **pcred;
+	const struct cred *cred, __rcu **pcred;
 
 	if (iomode == IOMODE_READ)
 		pcred = &mirror->ro_cred;
@@ -346,7 +346,7 @@ ff_layout_get_mirror_cred(struct nfs4_ff_layout_mirror *mirror, u32 iomode)
 		if (!cred)
 			break;
 
-		cred = get_rpccred_rcu(cred);
+		cred = get_cred_rcu(cred);
 	} while(!cred);
 	rcu_read_unlock();
 	return cred;
@@ -465,19 +465,19 @@ nfs4_ff_layout_prepare_ds(struct pnfs_layout_segment *lseg, u32 ds_idx,
 	return ds;
 }
 
-struct rpc_cred *
+const struct cred *
 ff_layout_get_ds_cred(struct pnfs_layout_segment *lseg, u32 ds_idx,
-		      struct rpc_cred *mdscred)
+		      const struct cred *mdscred)
 {
 	struct nfs4_ff_layout_mirror *mirror = FF_LAYOUT_COMP(lseg, ds_idx);
-	struct rpc_cred *cred;
+	const struct cred *cred;
 
 	if (mirror && !mirror->mirror_ds->ds_versions[0].tightly_coupled) {
 		cred = ff_layout_get_mirror_cred(mirror, lseg->pls_range.iomode);
 		if (!cred)
-			cred = get_rpccred(mdscred);
+			cred = get_cred(mdscred);
 	} else {
-		cred = get_rpccred(mdscred);
+		cred = get_cred(mdscred);
 	}
 	return cred;
 }

fs/nfs/inode.c

@@ -950,13 +950,11 @@ struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry,
 						struct file *filp)
 {
 	struct nfs_open_context *ctx;
-	struct rpc_cred *cred = rpc_lookup_cred();
-	if (IS_ERR(cred))
-		return ERR_CAST(cred);
+	const struct cred *cred = get_current_cred();
 
 	ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
 	if (!ctx) {
-		put_rpccred(cred);
+		put_cred(cred);
 		return ERR_PTR(-ENOMEM);
 	}
 	nfs_sb_active(dentry->d_sb);
@@ -998,8 +996,7 @@ static void __put_nfs_open_context(struct nfs_open_context *ctx, int is_sync)
 	}
 	if (inode != NULL)
 		NFS_PROTO(inode)->close_context(ctx, is_sync);
-	if (ctx->cred != NULL)
-		put_rpccred(ctx->cred);
+	put_cred(ctx->cred);
 	dput(ctx->dentry);
 	nfs_sb_deactive(sb);
 	put_rpccred(ctx->ll_cred);
@@ -1044,7 +1041,7 @@ EXPORT_SYMBOL_GPL(nfs_file_set_open_context);
 /*
  * Given an inode, search for an open context with the desired characteristics
  */
-struct nfs_open_context *nfs_find_open_context(struct inode *inode, struct rpc_cred *cred, fmode_t mode)
+struct nfs_open_context *nfs_find_open_context(struct inode *inode, const struct cred *cred, fmode_t mode)
 {
 	struct nfs_inode *nfsi = NFS_I(inode);
 	struct nfs_open_context *pos, *ctx = NULL;