[PATCH 5/5] NFS: Implement get_nfs_version()

[Anna Schumaker <anna@kernel.org>]

From: Anna Schumaker <anna.schumaker@oracle.com>

This is a pair for put_nfs_version(), and is used for incrementing the
reference count on the nfs version module. I also updated the callers I
could find who had this hardcoded up until now.

Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
---
 fs/nfs/client.c     | 10 ++++++++--
 fs/nfs/fs_context.c |  4 ++--
 fs/nfs/namespace.c  |  2 +-
 fs/nfs/nfs.h        |  1 +
 4 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 4fe5a635f329..68a88f29a1d6 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -100,12 +100,18 @@ struct nfs_subversion *find_nfs_version(unsigned int version)
 	if (!nfs)
 		return ERR_PTR(-EPROTONOSUPPORT);
 
-	if (!try_module_get(nfs->owner))
+	if (!get_nfs_version(nfs))
 		return ERR_PTR(-EAGAIN);
 
 	return nfs;
 }
 
+int get_nfs_version(struct nfs_subversion *nfs)
+{
+	return try_module_get(nfs->owner);
+}
+EXPORT_SYMBOL_GPL(get_nfs_version);
+
 void put_nfs_version(struct nfs_subversion *nfs)
 {
 	module_put(nfs->owner);
@@ -149,7 +155,7 @@ struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *cl_init)
 
 	clp->cl_minorversion = cl_init->minorversion;
 	clp->cl_nfs_mod = cl_init->nfs_mod;
-	if (!try_module_get(clp->cl_nfs_mod->owner))
+	if (!get_nfs_version(clp->cl_nfs_mod))
 		goto error_dealloc;
 
 	clp->rpc_ops = clp->cl_nfs_mod->rpc_ops;
diff --git a/fs/nfs/fs_context.c b/fs/nfs/fs_context.c
index d553daa4c09c..b069385eea17 100644
--- a/fs/nfs/fs_context.c
+++ b/fs/nfs/fs_context.c
@@ -1541,7 +1541,7 @@ static int nfs_fs_context_dup(struct fs_context *fc, struct fs_context *src_fc)
 	}
 	nfs_copy_fh(ctx->mntfh, src->mntfh);
 
-	__module_get(ctx->nfs_mod->owner);
+	get_nfs_version(ctx->nfs_mod);
 	ctx->client_address		= NULL;
 	ctx->mount_server.hostname	= NULL;
 	ctx->nfs_server.export_path	= NULL;
@@ -1633,7 +1633,7 @@ static int nfs_init_fs_context(struct fs_context *fc)
 		}
 
 		ctx->nfs_mod = nfss->nfs_client->cl_nfs_mod;
-		__module_get(ctx->nfs_mod->owner);
+		get_nfs_version(ctx->nfs_mod);
 	} else {
 		/* defaults */
 		ctx->timeo		= NFS_UNSPEC_TIMEO;
diff --git a/fs/nfs/namespace.c b/fs/nfs/namespace.c
index e7494cdd957e..2d53574da605 100644
--- a/fs/nfs/namespace.c
+++ b/fs/nfs/namespace.c
@@ -182,7 +182,7 @@ struct vfsmount *nfs_d_automount(struct path *path)
 	ctx->version		= client->rpc_ops->version;
 	ctx->minorversion	= client->cl_minorversion;
 	ctx->nfs_mod		= client->cl_nfs_mod;
-	__module_get(ctx->nfs_mod->owner);
+	get_nfs_version(ctx->nfs_mod);
 
 	ret = client->rpc_ops->submount(fc, server);
 	if (ret < 0) {
diff --git a/fs/nfs/nfs.h b/fs/nfs/nfs.h
index a30bf8ef79d7..8a5f51be013a 100644
--- a/fs/nfs/nfs.h
+++ b/fs/nfs/nfs.h
@@ -22,6 +22,7 @@ struct nfs_subversion {
 };
 
 struct nfs_subversion *find_nfs_version(unsigned int);
+int get_nfs_version(struct nfs_subversion *);
 void put_nfs_version(struct nfs_subversion *);
 void register_nfs_version(struct nfs_subversion *);
 void unregister_nfs_version(struct nfs_subversion *);
-- 
2.46.2