NFS: Implement get_nfs_version()

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 <[email protected]>
Signed-off-by: Trond Myklebust <[email protected]>

Author: Anna Schumaker

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;

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;

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) {

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 *);