[RFC v4 8/9] NFS: Don't shared transient clients

[Joshua Watt <jpewhacker@gmail.com>]

If the transient mount option is set the client should not be shared so
that operations done to it will not affect other mounts.

Signed-off-by: Joshua Watt <JPEWhacker@gmail.com>
---
 fs/nfs/client.c           | 9 +++++++--
 fs/nfs/nfs3client.c       | 2 ++
 fs/nfs/nfs4client.c       | 4 ++++
 include/linux/nfs_fs_sb.h | 1 +
 4 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 7bab47d0dd07..9d88dea4bc59 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -328,6 +328,10 @@ static struct nfs_client *nfs_match_client(const struct nfs_client_initdata *dat
 		if (clp->cl_cons_state < 0)
 			continue;
 
+		/* Don't match clients that don't want to be shared */
+		if (test_bit(NFS_CS_UNSHARED, &clp->cl_flags))
+			continue;
+
 		/* Different NFS versions cannot share the same nfs_client */
 		if (clp->rpc_ops != data->nfs_mod->rpc_ops)
 			continue;
@@ -428,7 +432,7 @@ init_client(struct nfs_client *new, const struct nfs_client_initdata *cl_init)
  */
 struct nfs_client *nfs_get_client(const struct nfs_client_initdata *cl_init)
 {
-	struct nfs_client *clp, *new = NULL;
+	struct nfs_client *clp = NULL, *new = NULL;
 	struct nfs_net *nn = net_generic(cl_init->net, nfs_net_id);
 	const struct nfs_rpc_ops *rpc_ops = cl_init->nfs_mod->rpc_ops;
 
@@ -441,7 +445,8 @@ struct nfs_client *nfs_get_client(const struct nfs_client_initdata *cl_init)
 	do {
 		spin_lock(&nn->nfs_client_lock);
 
-		clp = nfs_match_client(cl_init);
+		if (!test_bit(NFS_CS_UNSHARED, &cl_init->init_flags))
+			clp = nfs_match_client(cl_init);
 		if (clp) {
 			spin_unlock(&nn->nfs_client_lock);
 			if (new)
diff --git a/fs/nfs/nfs3client.c b/fs/nfs/nfs3client.c
index 7879f2a0fcfd..a627a925f210 100644
--- a/fs/nfs/nfs3client.c
+++ b/fs/nfs/nfs3client.c
@@ -102,6 +102,8 @@ struct nfs_client *nfs3_set_ds_client(struct nfs_server *mds_srv,
 
 	if (mds_srv->flags & NFS_MOUNT_NORESVPORT)
 		set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
+	if (mds_srv->flags & NFS_MOUNT_TRANSIENT)
+		__set_bit(NFS_CS_UNSHARED, &cl_init.init_flags);
 
 	/* Use the MDS nfs_client cl_ipaddr. */
 	nfs_init_timeout_values(&ds_timeout, ds_proto, ds_timeo, ds_retrans);
diff --git a/fs/nfs/nfs4client.c b/fs/nfs/nfs4client.c
index ef725106e45c..ffbc1143a4ab 100644
--- a/fs/nfs/nfs4client.c
+++ b/fs/nfs/nfs4client.c
@@ -852,6 +852,8 @@ static int nfs4_set_client(struct nfs_server *server,
 		set_bit(NFS_CS_MIGRATION, &cl_init.init_flags);
 	if (test_bit(NFS_MIG_TSM_POSSIBLE, &server->mig_status))
 		set_bit(NFS_CS_TSM_POSSIBLE, &cl_init.init_flags);
+	if (server->flags & NFS_MOUNT_TRANSIENT)
+		__set_bit(NFS_CS_UNSHARED, &cl_init.init_flags);
 
 	/* Allocate or find a client reference we can use */
 	clp = nfs_get_client(&cl_init);
@@ -910,6 +912,8 @@ struct nfs_client *nfs4_set_ds_client(struct nfs_server *mds_srv,
 
 	if (mds_srv->flags & NFS_MOUNT_NORESVPORT)
 		__set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
+	if (mds_srv->flags & NFS_MOUNT_TRANSIENT)
+		__set_bit(NFS_CS_UNSHARED, &cl_init.init_flags);
 
 	/*
 	 * Set an authflavor equual to the MDS value. Use the MDS nfs_client
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index 5dac856355f0..0eb7093faea7 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -45,6 +45,7 @@ struct nfs_client {
 #define NFS_CS_INFINITE_SLOTS	3		/* - don't limit TCP slots */
 #define NFS_CS_NO_RETRANS_TIMEOUT	4	/* - Disable retransmit timeouts */
 #define NFS_CS_TSM_POSSIBLE	5		/* - Maybe state migration */
+#define NFS_CS_UNSHARED		6		/* - Client state not shared */
 	struct sockaddr_storage	cl_addr;	/* server identifier */
 	size_t			cl_addrlen;
 	char *			cl_hostname;	/* hostname of server */
-- 
2.13.6