[PATCH Version 2 2/2] NFSv4.1 Use the MDS nfs_server authflavor for pNFS data server connections

[<andros@netapp.com>]

From: Andy Adamson <andros@netapp.com>

pNFS data servers are not mounted in the normal sense as there is no associated
nfs_server structure.

Commit 4edaa308 "NFS: Use "krb5i" to establish NFSv4 state whenever possible"
uses the nfs_client cl_rpcclient for all state management operations, and
will use krb5i or auth_sys with no regard to the mount command authflavor
choice.  For normal mounted servers, the nfs_server client authflavor is used
for all non-state management operations

Data servers use the same authflavor as the MDS mount for non-state management
operations. Note that the MDS has performed any sub-mounts and created an
nfs_server rpc client. Add an array of struct rpc_clnt to struct
nfs_client, one for each possible auth flavor for data server RPC connections.

Signed-off-by: Andy Adamson <andros@netapp.com>
---
 fs/nfs/client.c            | 14 +++++++++-
 fs/nfs/nfs4filelayout.c    | 65 ++++++++++++++++++++++++++++++++++++++--------
 fs/nfs/nfs4filelayout.h    | 17 ++++++++++++
 fs/nfs/nfs4filelayoutdev.c |  3 ++-
 include/linux/nfs_fs_sb.h  |  5 ++++
 5 files changed, 91 insertions(+), 13 deletions(-)

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 2dceee4..fc63967 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -152,7 +152,7 @@ struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *cl_init)
 {
 	struct nfs_client *clp;
 	struct rpc_cred *cred;
-	int err = -ENOMEM;
+	int err = -ENOMEM, i;
 
 	if ((clp = kzalloc(sizeof(*clp), GFP_KERNEL)) == NULL)
 		goto error_0;
@@ -177,6 +177,8 @@ struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *cl_init)
 
 	INIT_LIST_HEAD(&clp->cl_superblocks);
 	clp->cl_rpcclient = ERR_PTR(-EINVAL);
+	for (i = 0; i < NFS_NUM_DS_RPC_CLNT; i++)
+		clp->cl_ds_clnt[i] = ERR_PTR(-EINVAL);
 
 	clp->cl_proto = cl_init->proto;
 	clp->cl_net = get_net(cl_init->net);
@@ -238,6 +240,8 @@ static void pnfs_init_server(struct nfs_server *server)
  */
 void nfs_free_client(struct nfs_client *clp)
 {
+	int i;
+
 	dprintk("--> nfs_free_client(%u)\n", clp->rpc_ops->version);
 
 	nfs_fscache_release_client_cookie(clp);
@@ -246,6 +250,14 @@ void nfs_free_client(struct nfs_client *clp)
 	if (!IS_ERR(clp->cl_rpcclient))
 		rpc_shutdown_client(clp->cl_rpcclient);
 
+	for (i = 0; i < NFS_NUM_DS_RPC_CLNT; i++) {
+		if (!IS_ERR(clp->cl_ds_clnt[i])) {
+			dprintk("%s shutdown data server client %p index %d\n",
+				__func__, clp->cl_ds_clnt[i], i);
+			rpc_shutdown_client(clp->cl_ds_clnt[i]);
+		}
+	}
+
 	if (clp->cl_machine_cred != NULL)
 		put_rpccred(clp->cl_machine_cred);
 
diff --git a/fs/nfs/nfs4filelayout.c b/fs/nfs/nfs4filelayout.c
index 17ed87e..eb33592 100644
--- a/fs/nfs/nfs4filelayout.c
+++ b/fs/nfs/nfs4filelayout.c
@@ -83,6 +83,31 @@ filelayout_get_dserver_offset(struct pnfs_layout_segment *lseg, loff_t offset)
 	BUG();
 }
 
+/* Use the au_flavor of the MDS nfs_server RPC client to find or clone the
+ * correct data server RPC client.
+ *
+ * Note that the MDS has already performed any sub-mounts and negotiated
+ * a security flavor.
+ */
+static struct rpc_clnt *
+filelayout_rpc_clnt(struct inode *inode, struct nfs_client *clp)
+{
+	rpc_authflavor_t flavor = NFS_SERVER(inode)->client->cl_auth->au_flavor;
+	int index = filelayout_rpc_clnt_index(flavor);
+
+	if (index < 0)
+		return ERR_PTR(index);
+
+	if (IS_ERR(clp->cl_ds_clnt[index])) {
+		clp->cl_ds_clnt[index] =
+			rpc_clone_client_set_auth(clp->cl_rpcclient, flavor);
+
+		dprintk("%s clone data server client %p flavor %d index %d \n",
+			__func__, clp->cl_ds_clnt[index], flavor, index);
+	}
+	return clp->cl_ds_clnt[index];
+}
+
 static void filelayout_reset_write(struct nfs_write_data *data)
 {
 	struct nfs_pgio_header *hdr = data->header;
@@ -524,6 +549,7 @@ filelayout_read_pagelist(struct nfs_read_data *data)
 	struct nfs_pgio_header *hdr = data->header;
 	struct pnfs_layout_segment *lseg = hdr->lseg;
 	struct nfs4_pnfs_ds *ds;
+	struct rpc_clnt *ds_clnt;
 	loff_t offset = data->args.offset;
 	u32 j, idx;
 	struct nfs_fh *fh;
@@ -538,6 +564,11 @@ filelayout_read_pagelist(struct nfs_read_data *data)
 	ds = nfs4_fl_prepare_ds(lseg, idx);
 	if (!ds)
 		return PNFS_NOT_ATTEMPTED;
+
+	ds_clnt = filelayout_rpc_clnt(hdr->inode, ds->ds_clp);
+	if (IS_ERR(ds_clnt))
+		return PNFS_NOT_ATTEMPTED;
+
 	dprintk("%s USE DS: %s cl_count %d\n", __func__,
 		ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count));
 
@@ -552,8 +583,8 @@ filelayout_read_pagelist(struct nfs_read_data *data)
 	data->mds_offset = offset;
 
 	/* Perform an asynchronous read to ds */
-	nfs_initiate_read(ds->ds_clp->cl_rpcclient, data,
-				  &filelayout_read_call_ops, RPC_TASK_SOFTCONN);
+	nfs_initiate_read(ds_clnt, data, &filelayout_read_call_ops,
+			RPC_TASK_SOFTCONN);
 	return PNFS_ATTEMPTED;
 }
 
@@ -564,6 +595,7 @@ filelayout_write_pagelist(struct nfs_write_data *data, int sync)
 	struct nfs_pgio_header *hdr = data->header;
 	struct pnfs_layout_segment *lseg = hdr->lseg;
 	struct nfs4_pnfs_ds *ds;
+	struct rpc_clnt *ds_clnt;
 	loff_t offset = data->args.offset;
 	u32 j, idx;
 	struct nfs_fh *fh;
@@ -574,6 +606,11 @@ filelayout_write_pagelist(struct nfs_write_data *data, int sync)
 	ds = nfs4_fl_prepare_ds(lseg, idx);
 	if (!ds)
 		return PNFS_NOT_ATTEMPTED;
+
+	ds_clnt = filelayout_rpc_clnt(hdr->inode, ds->ds_clp);
+	if (IS_ERR(ds_clnt))
+		return PNFS_NOT_ATTEMPTED;
+
 	dprintk("%s ino %lu sync %d req %Zu@%llu DS: %s cl_count %d\n",
 		__func__, hdr->inode->i_ino, sync, (size_t) data->args.count,
 		offset, ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count));
@@ -591,9 +628,8 @@ filelayout_write_pagelist(struct nfs_write_data *data, int sync)
 	data->args.offset = filelayout_get_dserver_offset(lseg, offset);
 
 	/* Perform an asynchronous write */
-	nfs_initiate_write(ds->ds_clp->cl_rpcclient, data,
-				    &filelayout_write_call_ops, sync,
-				    RPC_TASK_SOFTCONN);
+	nfs_initiate_write(ds_clnt, data, &filelayout_write_call_ops, sync,
+				RPC_TASK_SOFTCONN);
 	return PNFS_ATTEMPTED;
 }
 
@@ -1101,16 +1137,19 @@ static int filelayout_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;
 	u32 idx;
 	struct nfs_fh *fh;
 
 	idx = calc_ds_index_from_commit(lseg, data->ds_commit_index);
 	ds = nfs4_fl_prepare_ds(lseg, idx);
-	if (!ds) {
-		prepare_to_resend_writes(data);
-		filelayout_commit_release(data);
-		return -EAGAIN;
-	}
+	if (!ds) 
+		goto out_err;
+
+	ds_clnt = filelayout_rpc_clnt(data->inode, ds->ds_clp);
+	if (IS_ERR(ds_clnt))
+		goto out_err;
+
 	dprintk("%s ino %lu, how %d cl_count %d\n", __func__,
 		data->inode->i_ino, how, atomic_read(&ds->ds_clp->cl_count));
 	data->commit_done_cb = filelayout_commit_done_cb;
@@ -1119,9 +1158,13 @@ static int filelayout_initiate_commit(struct nfs_commit_data *data, int how)
 	fh = select_ds_fh_from_commit(lseg, data->ds_commit_index);
 	if (fh)
 		data->args.fh = fh;
-	return nfs_initiate_commit(ds->ds_clp->cl_rpcclient, data,
+	return nfs_initiate_commit(ds_clnt, data,
 				   &filelayout_commit_call_ops, how,
 				   RPC_TASK_SOFTCONN);
+out_err:
+	prepare_to_resend_writes(data);
+	filelayout_commit_release(data);
+	return -EAGAIN;
 }
 
 static int
diff --git a/fs/nfs/nfs4filelayout.h b/fs/nfs/nfs4filelayout.h
index cebd20e..9bb39ec 100644
--- a/fs/nfs/nfs4filelayout.h
+++ b/fs/nfs/nfs4filelayout.h
@@ -136,6 +136,23 @@ filelayout_test_devid_invalid(struct nfs4_deviceid_node *node)
 	return test_bit(NFS_DEVICEID_INVALID, &node->flags);
 }
 
+static inline int
+filelayout_rpc_clnt_index(rpc_authflavor_t flavor)
+{
+	switch (flavor) {
+		case RPC_AUTH_UNIX:
+			return 0;
+		case RPC_AUTH_GSS_KRB5:
+			return 1;
+		case RPC_AUTH_GSS_KRB5I:
+			return 2;
+		case RPC_AUTH_GSS_KRB5P:
+			return 3;
+		default:
+			return -EINVAL;
+	}
+}
+
 extern bool
 filelayout_test_devid_unavailable(struct nfs4_deviceid_node *node);
 
diff --git a/fs/nfs/nfs4filelayoutdev.c b/fs/nfs/nfs4filelayoutdev.c
index 95604f6..fea056d 100644
--- a/fs/nfs/nfs4filelayoutdev.c
+++ b/fs/nfs/nfs4filelayoutdev.c
@@ -162,7 +162,7 @@ nfs4_ds_connect(struct nfs_server *mds_srv, struct nfs4_pnfs_ds *ds)
 	int status = 0;
 
 	dprintk("--> %s DS %s au_flavor %d\n", __func__, ds->ds_remotestr,
-		mds_srv->nfs_client->cl_rpcclient->cl_auth->au_flavor);
+		mds_srv->client->cl_auth->au_flavor);
 
 	list_for_each_entry(da, &ds->ds_addrs, da_node) {
 		dprintk("%s: DS %s: trying address %s\n",
@@ -186,6 +186,7 @@ nfs4_ds_connect(struct nfs_server *mds_srv, struct nfs4_pnfs_ds *ds)
 		goto out_put;
 
 	ds->ds_clp = clp;
+
 	dprintk("%s [new] addr: %s\n", __func__, ds->ds_remotestr);
 out:
 	return status;
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index d221243..bd86a1b 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -20,6 +20,10 @@ struct nfs4_minor_version_ops;
 struct nfs41_server_scope;
 struct nfs41_impl_id;
 
+
+/* One rpc clnt for each authentiction flavor */
+#define NFS_NUM_DS_RPC_CLNT 4
+
 /*
  * The nfs_client identifies our client state to the server.
  */
@@ -56,6 +60,7 @@ struct nfs_client {
 	struct rpc_cred		*cl_machine_cred;
 
 #if IS_ENABLED(CONFIG_NFS_V4)
+	struct rpc_clnt *	cl_ds_clnt[NFS_NUM_DS_RPC_CLNT];
 	u64			cl_clientid;	/* constant */
 	nfs4_verifier		cl_confirm;	/* Clientid verifier */
 	unsigned long		cl_state;
-- 
1.8.3.1