[PATCH 0/7] NFSv4.1+ support for session trunking discovery

[PATCH 0/7] NFSv4.1+ support for session trunking discovery

[Olga Kornievskaia]

From: Olga Kornievskaia <kolga@netapp.com>

This patch series adds session trunking discovery and setup. When a
client discovers a new file system in addition to probing for
existing attributes, it also sends a GETATTR asking for an fs_location
attribute. If it receives a non-zero length reply, it will iterate
thru the response and, for each server location, it will establish a
connection (of the same type as the existing RPC transport), send
an EXCHANGE_ID, and test for session trunking. If the trunking test
succeeds, the transport is added to an existing set of transports
for this server. 

Olga Kornievskaia (7):
  NFSv4 remove zero number of fs_locations entries error check
  NFSv4 store server support for fs_location attribute
  NFSv4.1 query for fs_location attr on a new file system
  NFSv4 expose nfs_parse_server_name function
  NFSv4 handle port presence in fs_location server string
  SUNRPC allow for unspecified transport time in rpc_clnt_add_xprt
  NFSv4.1 test and add 4.1 trunking transport

 fs/nfs/client.c           |   7 ++
 fs/nfs/nfs4_fs.h          |  12 ++--
 fs/nfs/nfs4namespace.c    |  19 ++++--
 fs/nfs/nfs4proc.c         | 131 +++++++++++++++++++++++++++++++++++---
 fs/nfs/nfs4state.c        |   6 +-
 fs/nfs/nfs4xdr.c          |   2 -
 include/linux/nfs_fs_sb.h |   2 +-
 include/linux/nfs_xdr.h   |   1 +
 net/sunrpc/clnt.c         |   5 +-
 9 files changed, 158 insertions(+), 27 deletions(-)

-- 
2.27.0

[PATCH 1/7] NFSv4 remove zero number of fs_locations entries error check

[Olga Kornievskaia]

From: Olga Kornievskaia <kolga@netapp.com>

Remove the check for the zero length fs_locations reply in the
xdr decoding, and instead check for that in the migration code.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
---
 fs/nfs/nfs4state.c | 3 +++
 fs/nfs/nfs4xdr.c   | 2 --
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index f63dfa01001c..f3265575c28d 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -2106,6 +2106,9 @@ static int nfs4_try_migration(struct nfs_server *server, const struct cred *cred
 	}
 
 	result = -NFS4ERR_NXIO;
+	if (!locations->nlocations)
+		goto out;
+
 	if (!(locations->fattr.valid & NFS_ATTR_FATTR_V4_LOCATIONS)) {
 		dprintk("<-- %s: No fs_locations data, migration skipped\n",
 			__func__);
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 801119b7a596..71a00e48bd2d 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -3696,8 +3696,6 @@ static int decode_attr_fs_locations(struct xdr_stream *xdr, uint32_t *bitmap, st
 	if (unlikely(!p))
 		goto out_eio;
 	n = be32_to_cpup(p);
-	if (n <= 0)
-		goto out_eio;
 	for (res->nlocations = 0; res->nlocations < n; res->nlocations++) {
 		u32 m;
 		struct nfs4_fs_location *loc;
-- 
2.27.0

[PATCH 2/7] NFSv4 store server support for fs_location attribute

[Olga Kornievskaia]

From: Olga Kornievskaia <kolga@netapp.com>

Define and store if server returns it supports fs_locations attribute
as a capability.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
---
 fs/nfs/nfs4proc.c         | 2 ++
 include/linux/nfs_fs_sb.h | 2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 535436dbdc9a..199f03c9d0b2 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -3873,6 +3873,8 @@ static int _nfs4_server_capabilities(struct nfs_server *server, struct nfs_fh *f
 		if (res.attr_bitmask[2] & FATTR4_WORD2_SECURITY_LABEL)
 			server->caps |= NFS_CAP_SECURITY_LABEL;
 #endif
+		if (res.attr_bitmask[0] & FATTR4_WORD0_FS_LOCATIONS)
+			server->caps |= NFS_CAP_FS_LOCATIONS;
 		if (!(res.attr_bitmask[0] & FATTR4_WORD0_FILEID))
 			server->fattr_valid &= ~NFS_ATTR_FATTR_FILEID;
 		if (!(res.attr_bitmask[1] & FATTR4_WORD1_MODE))
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index 2a9acbfe00f0..9a6e70ccde56 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -287,5 +287,5 @@ struct nfs_server {
 #define NFS_CAP_COPY_NOTIFY	(1U << 27)
 #define NFS_CAP_XATTR		(1U << 28)
 #define NFS_CAP_READ_PLUS	(1U << 29)
-
+#define NFS_CAP_FS_LOCATIONS	(1U << 30)
 #endif
-- 
2.27.0

[PATCH 3/7] NFSv4.1 query for fs_location attr on a new file system

[Olga Kornievskaia]

From: Olga Kornievskaia <kolga@netapp.com>

Query the server for other possible trunkable locations for a given
file system on a 4.1+ mount.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
---
 fs/nfs/client.c         |  7 ++++
 fs/nfs/nfs4_fs.h        |  9 ++---
 fs/nfs/nfs4proc.c       | 75 +++++++++++++++++++++++++++++++++++------
 fs/nfs/nfs4state.c      |  3 +-
 include/linux/nfs_xdr.h |  1 +
 5 files changed, 80 insertions(+), 15 deletions(-)

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 1e4dc1ab9312..f7e39cc4472b 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -860,6 +860,13 @@ static int nfs_probe_fsinfo(struct nfs_server *server, struct nfs_fh *mntfh, str
 			server->namelen = pathinfo.max_namelen;
 	}
 
+	if (clp->rpc_ops->discover_trunking != NULL &&
+			(server->caps & NFS_CAP_FS_LOCATIONS)) {
+		error = clp->rpc_ops->discover_trunking(server, mntfh);
+		if (error < 0)
+			return error;
+	}
+
 	return 0;
 }
 
diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index ed5eaca6801e..2402a3d8ba99 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -260,8 +260,8 @@ struct nfs4_state_maintenance_ops {
 };
 
 struct nfs4_mig_recovery_ops {
-	int (*get_locations)(struct inode *, struct nfs4_fs_locations *,
-		struct page *, const struct cred *);
+	int (*get_locations)(struct nfs_server *, struct nfs_fh *,
+		struct nfs4_fs_locations *, struct page *, const struct cred *);
 	int (*fsid_present)(struct inode *, const struct cred *);
 };
 
@@ -302,8 +302,9 @@ extern int nfs4_do_close(struct nfs4_state *state, gfp_t gfp_mask, int wait);
 extern int nfs4_server_capabilities(struct nfs_server *server, struct nfs_fh *fhandle);
 extern int nfs4_proc_fs_locations(struct rpc_clnt *, struct inode *, const struct qstr *,
 				  struct nfs4_fs_locations *, struct page *);
-extern int nfs4_proc_get_locations(struct inode *, struct nfs4_fs_locations *,
-		struct page *page, const struct cred *);
+extern int nfs4_proc_get_locations(struct nfs_server *, struct nfs_fh *,
+				   struct nfs4_fs_locations *,
+				   struct page *page, const struct cred *);
 extern int nfs4_proc_fsid_present(struct inode *, const struct cred *);
 extern struct rpc_clnt *nfs4_proc_lookup_mountpoint(struct inode *,
 						    struct dentry *,
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 199f03c9d0b2..9a6b53ec0eaa 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -3933,6 +3933,59 @@ int nfs4_server_capabilities(struct nfs_server *server, struct nfs_fh *fhandle)
 	return err;
 }
 
+static int _nfs4_discover_trunking(struct nfs_server *server,
+				   struct nfs_fh *fhandle)
+{
+	struct nfs4_fs_locations *locations = NULL;
+	struct page *page;
+	const struct cred *cred;
+	struct nfs_client *clp = server->nfs_client;
+	const struct nfs4_state_maintenance_ops *ops =
+		clp->cl_mvops->state_renewal_ops;
+	int status = -ENOMEM;
+
+	cred = ops->get_state_renewal_cred(clp);
+	if (cred == NULL) {
+		cred = nfs4_get_clid_cred(clp);
+		if (cred == NULL)
+			return -ENOKEY;
+	}
+
+	page = alloc_page(GFP_KERNEL);
+	locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
+	if (page == NULL || locations == NULL)
+		goto out;
+
+	status = nfs4_proc_get_locations(server, fhandle, locations, page,
+					 cred);
+	if (status)
+		goto out;
+out:
+	if (page)
+		__free_page(page);
+	kfree(locations);
+	return status;
+}
+
+int nfs4_discover_trunking(struct nfs_server *server, struct nfs_fh *fhandle)
+{
+	struct nfs4_exception exception = {
+		.interruptible = true,
+	};
+	struct nfs_client *clp = server->nfs_client;
+	int err = 0;
+
+	if (!nfs4_has_session(clp))
+		goto out;
+	do {
+		err = nfs4_handle_exception(server,
+				_nfs4_discover_trunking(server, fhandle),
+				&exception);
+	} while (exception.retry);
+out:
+	return err;
+}
+
 static int _nfs4_lookup_root(struct nfs_server *server, struct nfs_fh *fhandle,
 		struct nfs_fsinfo *info)
 {
@@ -7819,18 +7872,18 @@ int nfs4_proc_fs_locations(struct rpc_clnt *client, struct inode *dir,
  * appended to this compound to identify the client ID which is
  * performing recovery.
  */
-static int _nfs40_proc_get_locations(struct inode *inode,
+static int _nfs40_proc_get_locations(struct nfs_server *server,
+				     struct nfs_fh *fhandle,
 				     struct nfs4_fs_locations *locations,
 				     struct page *page, const struct cred *cred)
 {
-	struct nfs_server *server = NFS_SERVER(inode);
 	struct rpc_clnt *clnt = server->client;
 	u32 bitmask[2] = {
 		[0] = FATTR4_WORD0_FSID | FATTR4_WORD0_FS_LOCATIONS,
 	};
 	struct nfs4_fs_locations_arg args = {
 		.clientid	= server->nfs_client->cl_clientid,
-		.fh		= NFS_FH(inode),
+		.fh		= fhandle,
 		.page		= page,
 		.bitmask	= bitmask,
 		.migration	= 1,		/* skip LOOKUP */
@@ -7876,17 +7929,17 @@ static int _nfs40_proc_get_locations(struct inode *inode,
  * When the client supports GETATTR(fs_locations_info), it can
  * be plumbed in here.
  */
-static int _nfs41_proc_get_locations(struct inode *inode,
+static int _nfs41_proc_get_locations(struct nfs_server *server,
+				     struct nfs_fh *fhandle,
 				     struct nfs4_fs_locations *locations,
 				     struct page *page, const struct cred *cred)
 {
-	struct nfs_server *server = NFS_SERVER(inode);
 	struct rpc_clnt *clnt = server->client;
 	u32 bitmask[2] = {
 		[0] = FATTR4_WORD0_FSID | FATTR4_WORD0_FS_LOCATIONS,
 	};
 	struct nfs4_fs_locations_arg args = {
-		.fh		= NFS_FH(inode),
+		.fh		= fhandle,
 		.page		= page,
 		.bitmask	= bitmask,
 		.migration	= 1,		/* skip LOOKUP */
@@ -7935,11 +7988,11 @@ static int _nfs41_proc_get_locations(struct inode *inode,
  * -NFS4ERR_LEASE_MOVED is returned if the server still has leases
  * from this client that require migration recovery.
  */
-int nfs4_proc_get_locations(struct inode *inode,
+int nfs4_proc_get_locations(struct nfs_server *server,
+			    struct nfs_fh *fhandle,
 			    struct nfs4_fs_locations *locations,
 			    struct page *page, const struct cred *cred)
 {
-	struct nfs_server *server = NFS_SERVER(inode);
 	struct nfs_client *clp = server->nfs_client;
 	const struct nfs4_mig_recovery_ops *ops =
 					clp->cl_mvops->mig_recovery_ops;
@@ -7952,10 +8005,11 @@ int nfs4_proc_get_locations(struct inode *inode,
 		(unsigned long long)server->fsid.major,
 		(unsigned long long)server->fsid.minor,
 		clp->cl_hostname);
-	nfs_display_fhandle(NFS_FH(inode), __func__);
+	nfs_display_fhandle(fhandle, __func__);
 
 	do {
-		status = ops->get_locations(inode, locations, page, cred);
+		status = ops->get_locations(server, fhandle, locations, page,
+					    cred);
 		if (status != -NFS4ERR_DELAY)
 			break;
 		nfs4_handle_exception(server, status, &exception);
@@ -10424,6 +10478,7 @@ const struct nfs_rpc_ops nfs_v4_clientops = {
 	.free_client	= nfs4_free_client,
 	.create_server	= nfs4_create_server,
 	.clone_server	= nfs_clone_server,
+	.discover_trunking = nfs4_discover_trunking,
 };
 
 static const struct xattr_handler nfs4_xattr_nfs4_acl_handler = {
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index f3265575c28d..499bef9fe118 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -2098,7 +2098,8 @@ static int nfs4_try_migration(struct nfs_server *server, const struct cred *cred
 	}
 
 	inode = d_inode(server->super->s_root);
-	result = nfs4_proc_get_locations(inode, locations, page, cred);
+	result = nfs4_proc_get_locations(server, NFS_FH(inode), locations,
+					 page, cred);
 	if (result) {
 		dprintk("<-- %s: failed to retrieve fs_locations: %d\n",
 			__func__, result);
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index 967a0098f0a9..695fa84611b6 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -1795,6 +1795,7 @@ struct nfs_rpc_ops {
 	struct nfs_server *(*create_server)(struct fs_context *);
 	struct nfs_server *(*clone_server)(struct nfs_server *, struct nfs_fh *,
 					   struct nfs_fattr *, rpc_authflavor_t);
+	int	(*discover_trunking)(struct nfs_server *, struct nfs_fh *);
 };
 
 /*
-- 
2.27.0

[PATCH 4/7] NFSv4 expose nfs_parse_server_name function

[Olga Kornievskaia]

From: Olga Kornievskaia <kolga@netapp.com>

Make nfs_parse_server_name available outside of nfs4namespace.c.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
---
 fs/nfs/nfs4_fs.h       | 3 ++-
 fs/nfs/nfs4namespace.c | 4 ++--
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index 2402a3d8ba99..734ac09becf7 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -280,7 +280,8 @@ struct rpc_clnt *nfs4_negotiate_security(struct rpc_clnt *, struct inode *,
 int nfs4_submount(struct fs_context *, struct nfs_server *);
 int nfs4_replace_transport(struct nfs_server *server,
 				const struct nfs4_fs_locations *locations);
-
+size_t nfs_parse_server_name(char *string, size_t len, struct sockaddr *sa,
+			     size_t salen, struct net *net);
 /* nfs4proc.c */
 extern int nfs4_handle_exception(struct nfs_server *, int, struct nfs4_exception *);
 extern int nfs4_async_handle_error(struct rpc_task *task,
diff --git a/fs/nfs/nfs4namespace.c b/fs/nfs/nfs4namespace.c
index 873342308dc0..f1ed4f60a7f3 100644
--- a/fs/nfs/nfs4namespace.c
+++ b/fs/nfs/nfs4namespace.c
@@ -164,8 +164,8 @@ static int nfs4_validate_fspath(struct dentry *dentry,
 	return 0;
 }
 
-static size_t nfs_parse_server_name(char *string, size_t len,
-		struct sockaddr *sa, size_t salen, struct net *net)
+size_t nfs_parse_server_name(char *string, size_t len, struct sockaddr *sa,
+			     size_t salen, struct net *net)
 {
 	ssize_t ret;
 
-- 
2.27.0

[PATCH 5/7] NFSv4 handle port presence in fs_location server string

[Olga Kornievskaia]

From: Olga Kornievskaia <kolga@netapp.com>

An fs_location attribute returns a string that can be ipv4, ipv6,
or DNS name. An ip location can have a port appended to it and if
no port is present a default port needs to be set. If rpc_pton()
fails to parse, try calling rpc_uaddr2socaddr() that can convert
an universal address.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
---
 fs/nfs/nfs4_fs.h       |  2 +-
 fs/nfs/nfs4namespace.c | 17 +++++++++++------
 2 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index 734ac09becf7..85c5d08dfa9c 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -281,7 +281,7 @@ int nfs4_submount(struct fs_context *, struct nfs_server *);
 int nfs4_replace_transport(struct nfs_server *server,
 				const struct nfs4_fs_locations *locations);
 size_t nfs_parse_server_name(char *string, size_t len, struct sockaddr *sa,
-			     size_t salen, struct net *net);
+			     size_t salen, struct net *net, int port);
 /* nfs4proc.c */
 extern int nfs4_handle_exception(struct nfs_server *, int, struct nfs4_exception *);
 extern int nfs4_async_handle_error(struct rpc_task *task,
diff --git a/fs/nfs/nfs4namespace.c b/fs/nfs/nfs4namespace.c
index f1ed4f60a7f3..3680c8da510c 100644
--- a/fs/nfs/nfs4namespace.c
+++ b/fs/nfs/nfs4namespace.c
@@ -165,15 +165,20 @@ static int nfs4_validate_fspath(struct dentry *dentry,
 }
 
 size_t nfs_parse_server_name(char *string, size_t len, struct sockaddr *sa,
-			     size_t salen, struct net *net)
+			     size_t salen, struct net *net, int port)
 {
 	ssize_t ret;
 
 	ret = rpc_pton(net, string, len, sa, salen);
 	if (ret == 0) {
-		ret = nfs_dns_resolve_name(net, string, len, sa, salen);
-		if (ret < 0)
-			ret = 0;
+		ret = rpc_uaddr2sockaddr(net, string, len, sa, salen);
+		if (ret == 0) {
+			ret = nfs_dns_resolve_name(net, string, len, sa, salen);
+			if (ret < 0)
+				ret = 0;
+		}
+	} else if (port) {
+		rpc_set_port(sa, port);
 	}
 	return ret;
 }
@@ -328,7 +333,7 @@ static int try_location(struct fs_context *fc,
 			nfs_parse_server_name(buf->data, buf->len,
 					      &ctx->nfs_server.address,
 					      sizeof(ctx->nfs_server._address),
-					      fc->net_ns);
+					      fc->net_ns, 0);
 		if (ctx->nfs_server.addrlen == 0)
 			continue;
 
@@ -496,7 +501,7 @@ static int nfs4_try_replacing_one_location(struct nfs_server *server,
 			continue;
 
 		salen = nfs_parse_server_name(buf->data, buf->len,
-						sap, addr_bufsize, net);
+						sap, addr_bufsize, net, 0);
 		if (salen == 0)
 			continue;
 		rpc_set_port(sap, NFS_PORT);
-- 
2.27.0

[PATCH 6/7] SUNRPC allow for unspecified transport time in rpc_clnt_add_xprt

[Olga Kornievskaia]

From: Olga Kornievskaia <kolga@netapp.com>

If the supplied argument doesn't specify the transport type, use the
type of the existing rpc clnt and its existing transport.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
---
 net/sunrpc/clnt.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index a312ea2bc440..c83fe618767c 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -2900,7 +2900,7 @@ int rpc_clnt_add_xprt(struct rpc_clnt *clnt,
 	unsigned long connect_timeout;
 	unsigned long reconnect_timeout;
 	unsigned char resvport, reuseport;
-	int ret = 0;
+	int ret = 0, ident;
 
 	rcu_read_lock();
 	xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
@@ -2914,8 +2914,11 @@ int rpc_clnt_add_xprt(struct rpc_clnt *clnt,
 	reuseport = xprt->reuseport;
 	connect_timeout = xprt->connect_timeout;
 	reconnect_timeout = xprt->max_reconnect_timeout;
+	ident = xprt->xprt_class->ident;
 	rcu_read_unlock();
 
+	if (!xprtargs->ident)
+		xprtargs->ident = ident;
 	xprt = xprt_create_transport(xprtargs);
 	if (IS_ERR(xprt)) {
 		ret = PTR_ERR(xprt);
-- 
2.27.0

[PATCH 7/7] NFSv4.1 test and add 4.1 trunking transport

[Olga Kornievskaia]

From: Olga Kornievskaia <kolga@netapp.com>

For each location returned in FS_LOCATION query, establish a
transport to the server, send EXCHANGE_ID and test for trunking,
if successful, add the transport to the exiting client.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
---
 fs/nfs/nfs4proc.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 55 insertions(+), 1 deletion(-)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 9a6b53ec0eaa..0529c60c27e9 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -3933,6 +3933,56 @@ int nfs4_server_capabilities(struct nfs_server *server, struct nfs_fh *fhandle)
 	return err;
 }
 
+static void test_fs_location_for_trunking(struct nfs4_fs_location *location,
+					  struct nfs_client *clp,
+					  struct nfs_server *server)
+{
+	int i;
+
+	for (i = 0; i < location->nservers; i++) {
+		struct nfs4_string *srv_loc = &location->servers[i];
+		struct sockaddr addr;
+		size_t addrlen;
+		struct xprt_create xprt_args = {
+			.ident = 0,
+			.net = clp->cl_net,
+		};
+		struct nfs4_add_xprt_data xprtdata = {
+			.clp = clp,
+		};
+		struct rpc_add_xprt_test rpcdata = {
+			.add_xprt_test = clp->cl_mvops->session_trunk,
+			.data = &xprtdata,
+		};
+		char *servername = NULL;
+
+		if (!srv_loc->len)
+			continue;
+
+		addrlen = nfs_parse_server_name(srv_loc->data, srv_loc->len,
+						&addr, sizeof(addr),
+						clp->cl_net, server->port);
+		if (!addrlen)
+			return;
+		xprt_args.dstaddr = &addr;
+		xprt_args.addrlen = addrlen;
+		servername = kmalloc(srv_loc->len + 1, GFP_KERNEL);
+		if (!servername)
+			return;
+		memcpy(servername, srv_loc->data, srv_loc->len);
+		servername[srv_loc->len] = '\0';
+		xprt_args.servername = servername;
+
+		xprtdata.cred = nfs4_get_clid_cred(clp);
+		rpc_clnt_add_xprt(clp->cl_rpcclient, &xprt_args,
+				  rpc_clnt_setup_test_and_add_xprt,
+				  &rpcdata);
+		if (xprtdata.cred)
+			put_cred(xprtdata.cred);
+		kfree(servername);
+	}
+}
+
 static int _nfs4_discover_trunking(struct nfs_server *server,
 				   struct nfs_fh *fhandle)
 {
@@ -3942,7 +3992,7 @@ static int _nfs4_discover_trunking(struct nfs_server *server,
 	struct nfs_client *clp = server->nfs_client;
 	const struct nfs4_state_maintenance_ops *ops =
 		clp->cl_mvops->state_renewal_ops;
-	int status = -ENOMEM;
+	int status = -ENOMEM, i;
 
 	cred = ops->get_state_renewal_cred(clp);
 	if (cred == NULL) {
@@ -3960,6 +4010,10 @@ static int _nfs4_discover_trunking(struct nfs_server *server,
 					 cred);
 	if (status)
 		goto out;
+
+	for (i = 0; i < locations->nlocations; i++)
+		test_fs_location_for_trunking(&locations->locations[i], clp,
+					      server);
 out:
 	if (page)
 		__free_page(page);
-- 
2.27.0

Re: [PATCH 0/7] NFSv4.1+ support for session trunking discovery

[Wang Yugui]

Hi,

We need a option to control active-active or active-standby mode?
1) active-active    will get better performance when 10GbE/25GbE ports?
2) active-standby will get better performance when 100GbE/40GbE ports?

Best Regards
Wang Yugui (wangyugui@e16-tech.com)
2021/12/11

> From: Olga Kornievskaia <kolga@netapp.com>
> 
> This patch series adds session trunking discovery and setup. When a
> client discovers a new file system in addition to probing for
> existing attributes, it also sends a GETATTR asking for an fs_location
> attribute. If it receives a non-zero length reply, it will iterate
> thru the response and, for each server location, it will establish a
> connection (of the same type as the existing RPC transport), send
> an EXCHANGE_ID, and test for session trunking. If the trunking test
> succeeds, the transport is added to an existing set of transports
> for this server. 
> 
> Olga Kornievskaia (7):
>   NFSv4 remove zero number of fs_locations entries error check
>   NFSv4 store server support for fs_location attribute
>   NFSv4.1 query for fs_location attr on a new file system
>   NFSv4 expose nfs_parse_server_name function
>   NFSv4 handle port presence in fs_location server string
>   SUNRPC allow for unspecified transport time in rpc_clnt_add_xprt
>   NFSv4.1 test and add 4.1 trunking transport
> 
>  fs/nfs/client.c           |   7 ++
>  fs/nfs/nfs4_fs.h          |  12 ++--
>  fs/nfs/nfs4namespace.c    |  19 ++++--
>  fs/nfs/nfs4proc.c         | 131 +++++++++++++++++++++++++++++++++++---
>  fs/nfs/nfs4state.c        |   6 +-
>  fs/nfs/nfs4xdr.c          |   2 -
>  include/linux/nfs_fs_sb.h |   2 +-
>  include/linux/nfs_xdr.h   |   1 +
>  net/sunrpc/clnt.c         |   5 +-
>  9 files changed, 158 insertions(+), 27 deletions(-)
> 
> -- 
> 2.27.0