1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_SUNRPC_RPC_PIPE_FS_H
3 #define _LINUX_SUNRPC_RPC_PIPE_FS_H
4 
5 #include <linux/workqueue.h>
6 
7 struct rpc_pipe_dir_head {
8 	struct list_head pdh_entries;
9 	struct dentry *pdh_dentry;
10 };
11 
12 struct rpc_pipe_dir_object_ops;
13 struct rpc_pipe_dir_object {
14 	struct list_head pdo_head;
15 	const struct rpc_pipe_dir_object_ops *pdo_ops;
16 
17 	void *pdo_data;
18 };
19 
20 struct rpc_pipe_dir_object_ops {
21 	int (*create)(struct dentry *dir,
22 			struct rpc_pipe_dir_object *pdo);
23 	void (*destroy)(struct dentry *dir,
24 			struct rpc_pipe_dir_object *pdo);
25 };
26 
27 struct rpc_pipe_msg {
28 	struct list_head list;
29 	void *data;
30 	size_t len;
31 	size_t copied;
32 	int errno;
33 };
34 
35 struct rpc_pipe_ops {
36 	ssize_t (*upcall)(struct file *, struct rpc_pipe_msg *, char __user *, size_t);
37 	ssize_t (*downcall)(struct file *, const char __user *, size_t);
38 	void (*release_pipe)(struct inode *);
39 	int (*open_pipe)(struct inode *);
40 	void (*destroy_msg)(struct rpc_pipe_msg *);
41 };
42 
43 struct rpc_pipe {
44 	struct list_head pipe;
45 	struct list_head in_upcall;
46 	struct list_head in_downcall;
47 	int pipelen;
48 	int nreaders;
49 	int nwriters;
50 #define RPC_PIPE_WAIT_FOR_OPEN	1
51 	int flags;
52 	struct delayed_work queue_timeout;
53 	const struct rpc_pipe_ops *ops;
54 	spinlock_t lock;
55 	struct dentry *dentry;
56 };
57 
58 struct rpc_inode {
59 	struct inode vfs_inode;
60 	void *private;
61 	struct rpc_pipe *pipe;
62 	wait_queue_head_t waitq;
63 };
64 
65 static inline struct rpc_inode *
RPC_I(struct inode * inode)66 RPC_I(struct inode *inode)
67 {
68 	return container_of(inode, struct rpc_inode, vfs_inode);
69 }
70 
71 enum {
72 	SUNRPC_PIPEFS_NFS_PRIO,
73 	SUNRPC_PIPEFS_RPC_PRIO,
74 };
75 
76 extern int rpc_pipefs_notifier_register(struct notifier_block *);
77 extern void rpc_pipefs_notifier_unregister(struct notifier_block *);
78 
79 enum {
80 	RPC_PIPEFS_MOUNT,
81 	RPC_PIPEFS_UMOUNT,
82 };
83 
84 extern struct dentry *rpc_d_lookup_sb(const struct super_block *sb,
85 				      const unsigned char *dir_name);
86 extern int rpc_pipefs_init_net(struct net *net);
87 extern void rpc_pipefs_exit_net(struct net *net);
88 extern struct super_block *rpc_get_sb_net(const struct net *net);
89 extern void rpc_put_sb_net(const struct net *net);
90 
91 extern ssize_t rpc_pipe_generic_upcall(struct file *, struct rpc_pipe_msg *,
92 				       char __user *, size_t);
93 extern int rpc_queue_upcall(struct rpc_pipe *, struct rpc_pipe_msg *);
94 
95 /* returns true if the msg is in-flight, i.e., already eaten by the peer */
rpc_msg_is_inflight(const struct rpc_pipe_msg * msg)96 static inline bool rpc_msg_is_inflight(const struct rpc_pipe_msg *msg) {
97 	return (msg->copied != 0 && list_empty(&msg->list));
98 }
99 
100 struct rpc_clnt;
101 extern struct dentry *rpc_create_client_dir(struct dentry *, const char *, struct rpc_clnt *);
102 extern int rpc_remove_client_dir(struct rpc_clnt *);
103 
104 extern void rpc_init_pipe_dir_head(struct rpc_pipe_dir_head *pdh);
105 extern void rpc_init_pipe_dir_object(struct rpc_pipe_dir_object *pdo,
106 		const struct rpc_pipe_dir_object_ops *pdo_ops,
107 		void *pdo_data);
108 extern int rpc_add_pipe_dir_object(struct net *net,
109 		struct rpc_pipe_dir_head *pdh,
110 		struct rpc_pipe_dir_object *pdo);
111 extern void rpc_remove_pipe_dir_object(struct net *net,
112 		struct rpc_pipe_dir_head *pdh,
113 		struct rpc_pipe_dir_object *pdo);
114 extern struct rpc_pipe_dir_object *rpc_find_or_alloc_pipe_dir_object(
115 		struct net *net,
116 		struct rpc_pipe_dir_head *pdh,
117 		int (*match)(struct rpc_pipe_dir_object *, void *),
118 		struct rpc_pipe_dir_object *(*alloc)(void *),
119 		void *data);
120 
121 struct cache_detail;
122 extern struct dentry *rpc_create_cache_dir(struct dentry *,
123 					   const char *,
124 					   umode_t umode,
125 					   struct cache_detail *);
126 extern void rpc_remove_cache_dir(struct dentry *);
127 
128 struct rpc_pipe *rpc_mkpipe_data(const struct rpc_pipe_ops *ops, int flags);
129 void rpc_destroy_pipe_data(struct rpc_pipe *pipe);
130 extern struct dentry *rpc_mkpipe_dentry(struct dentry *, const char *, void *,
131 					struct rpc_pipe *);
132 extern int rpc_unlink(struct dentry *);
133 extern int register_rpc_pipefs(void);
134 extern void unregister_rpc_pipefs(void);
135 
136 extern bool gssd_running(struct net *net);
137 
138 #endif
139