xref: /linux-6.15/include/linux/lockd/lockd.h (revision 8802f616)
1 /*
2  * linux/include/linux/lockd/lockd.h
3  *
4  * General-purpose lockd include file.
5  *
6  * Copyright (C) 1996 Olaf Kirch <[email protected]>
7  */
8 
9 #ifndef LINUX_LOCKD_LOCKD_H
10 #define LINUX_LOCKD_LOCKD_H
11 
12 #ifdef __KERNEL__
13 
14 #include <linux/in.h>
15 #include <linux/fs.h>
16 #include <linux/kref.h>
17 #include <linux/utsname.h>
18 #include <linux/nfsd/nfsfh.h>
19 #include <linux/lockd/bind.h>
20 #include <linux/lockd/xdr.h>
21 #ifdef CONFIG_LOCKD_V4
22 #include <linux/lockd/xdr4.h>
23 #endif
24 #include <linux/lockd/debug.h>
25 
26 /*
27  * Version string
28  */
29 #define LOCKD_VERSION		"0.5"
30 
31 /*
32  * Default timeout for RPC calls (seconds)
33  */
34 #define LOCKD_DFLT_TIMEO	10
35 
36 /*
37  * Lockd host handle (used both by the client and server personality).
38  */
39 struct nlm_host {
40 	struct nlm_host *	h_next;		/* linked list (hash table) */
41 	struct sockaddr_in	h_addr;		/* peer address */
42 	struct rpc_clnt	*	h_rpcclnt;	/* RPC client to talk to peer */
43 	char			h_name[20];	/* remote hostname */
44 	u32			h_version;	/* interface version */
45 	unsigned short		h_proto;	/* transport proto */
46 	unsigned short		h_reclaiming : 1,
47 				h_server     : 1, /* server side, not client side */
48 				h_inuse      : 1,
49 				h_killed     : 1,
50 				h_monitored  : 1;
51 	wait_queue_head_t	h_gracewait;	/* wait while reclaiming */
52 	struct rw_semaphore	h_rwsem;	/* Reboot recovery lock */
53 	u32			h_state;	/* pseudo-state counter */
54 	u32			h_nsmstate;	/* true remote NSM state */
55 	u32			h_pidcount;	/* Pseudopids */
56 	atomic_t		h_count;	/* reference count */
57 	struct mutex		h_mutex;	/* mutex for pmap binding */
58 	unsigned long		h_nextrebind;	/* next portmap call */
59 	unsigned long		h_expires;	/* eligible for GC */
60 	struct list_head	h_lockowners;	/* Lockowners for the client */
61 	spinlock_t		h_lock;
62 	struct list_head	h_granted;	/* Locks in GRANTED state */
63 	struct list_head	h_reclaim;	/* Locks in RECLAIM state */
64 };
65 
66 /*
67  * Map an fl_owner_t into a unique 32-bit "pid"
68  */
69 struct nlm_lockowner {
70 	struct list_head list;
71 	atomic_t count;
72 
73 	struct nlm_host *host;
74 	fl_owner_t owner;
75 	uint32_t pid;
76 };
77 
78 struct nlm_wait;
79 
80 /*
81  * Memory chunk for NLM client RPC request.
82  */
83 #define NLMCLNT_OHSIZE		(sizeof(system_utsname.nodename)+10)
84 struct nlm_rqst {
85 	unsigned int		a_flags;	/* initial RPC task flags */
86 	struct nlm_host *	a_host;		/* host handle */
87 	struct nlm_args		a_args;		/* arguments */
88 	struct nlm_res		a_res;		/* result */
89 	struct nlm_block *	a_block;
90 	unsigned int		a_retries;	/* Retry count */
91 	u8			a_owner[NLMCLNT_OHSIZE];
92 };
93 
94 /*
95  * This struct describes a file held open by lockd on behalf of
96  * an NFS client.
97  */
98 struct nlm_file {
99 	struct nlm_file *	f_next;		/* linked list */
100 	struct nfs_fh		f_handle;	/* NFS file handle */
101 	struct file *		f_file;		/* VFS file pointer */
102 	struct nlm_share *	f_shares;	/* DOS shares */
103 	struct nlm_block *	f_blocks;	/* blocked locks */
104 	unsigned int		f_locks;	/* guesstimate # of locks */
105 	unsigned int		f_count;	/* reference count */
106 	struct semaphore	f_sema;		/* avoid concurrent access */
107 	int		       	f_hash;		/* hash of f_handle */
108 };
109 
110 /*
111  * This is a server block (i.e. a lock requested by some client which
112  * couldn't be granted because of a conflicting lock).
113  */
114 #define NLM_NEVER		(~(unsigned long) 0)
115 struct nlm_block {
116 	struct kref		b_count;	/* Reference count */
117 	struct nlm_block *	b_next;		/* linked list (all blocks) */
118 	struct nlm_block *	b_fnext;	/* linked list (per file) */
119 	struct nlm_rqst	*	b_call;		/* RPC args & callback info */
120 	struct svc_serv *	b_daemon;	/* NLM service */
121 	struct nlm_host *	b_host;		/* host handle for RPC clnt */
122 	unsigned long		b_when;		/* next re-xmit */
123 	unsigned int		b_id;		/* block id */
124 	unsigned char		b_queued;	/* re-queued */
125 	unsigned char		b_granted;	/* VFS granted lock */
126 	struct nlm_file *	b_file;		/* file in question */
127 };
128 
129 /*
130  * Valid actions for nlmsvc_traverse_files
131  */
132 #define NLM_ACT_CHECK		0		/* check for locks */
133 #define NLM_ACT_MARK		1		/* mark & sweep */
134 #define NLM_ACT_UNLOCK		2		/* release all locks */
135 
136 /*
137  * Global variables
138  */
139 extern struct rpc_program	nlm_program;
140 extern struct svc_procedure	nlmsvc_procedures[];
141 #ifdef CONFIG_LOCKD_V4
142 extern struct svc_procedure	nlmsvc_procedures4[];
143 #endif
144 extern int			nlmsvc_grace_period;
145 extern unsigned long		nlmsvc_timeout;
146 
147 /*
148  * Lockd client functions
149  */
150 struct nlm_rqst * nlm_alloc_call(struct nlm_host *host);
151 void		  nlm_release_call(struct nlm_rqst *);
152 int		  nlm_async_call(struct nlm_rqst *, u32, const struct rpc_call_ops *);
153 int		  nlm_async_reply(struct nlm_rqst *, u32, const struct rpc_call_ops *);
154 struct nlm_wait * nlmclnt_prepare_block(struct nlm_host *host, struct file_lock *fl);
155 void		  nlmclnt_finish_block(struct nlm_wait *block);
156 int		  nlmclnt_block(struct nlm_wait *block, struct nlm_rqst *req, long timeout);
157 u32		  nlmclnt_grant(const struct sockaddr_in *addr, const struct nlm_lock *);
158 void		  nlmclnt_recovery(struct nlm_host *, u32);
159 int		  nlmclnt_reclaim(struct nlm_host *, struct file_lock *);
160 
161 /*
162  * Host cache
163  */
164 struct nlm_host * nlmclnt_lookup_host(struct sockaddr_in *, int, int);
165 struct nlm_host * nlmsvc_lookup_host(struct svc_rqst *);
166 struct nlm_host * nlm_lookup_host(int server, struct sockaddr_in *, int, int);
167 struct rpc_clnt * nlm_bind_host(struct nlm_host *);
168 void		  nlm_rebind_host(struct nlm_host *);
169 struct nlm_host * nlm_get_host(struct nlm_host *);
170 void		  nlm_release_host(struct nlm_host *);
171 void		  nlm_shutdown_hosts(void);
172 extern struct nlm_host *nlm_find_client(void);
173 
174 
175 /*
176  * Server-side lock handling
177  */
178 u32		  nlmsvc_lock(struct svc_rqst *, struct nlm_file *,
179 					struct nlm_lock *, int, struct nlm_cookie *);
180 u32		  nlmsvc_unlock(struct nlm_file *, struct nlm_lock *);
181 u32		  nlmsvc_testlock(struct nlm_file *, struct nlm_lock *,
182 					struct nlm_lock *);
183 u32		  nlmsvc_cancel_blocked(struct nlm_file *, struct nlm_lock *);
184 unsigned long	  nlmsvc_retry_blocked(void);
185 void		  nlmsvc_traverse_blocks(struct nlm_host *, struct nlm_file *,
186 					int action);
187 void	  nlmsvc_grant_reply(struct svc_rqst *, struct nlm_cookie *, u32);
188 
189 /*
190  * File handling for the server personality
191  */
192 u32		  nlm_lookup_file(struct svc_rqst *, struct nlm_file **,
193 					struct nfs_fh *);
194 void		  nlm_release_file(struct nlm_file *);
195 void		  nlmsvc_mark_resources(void);
196 void		  nlmsvc_free_host_resources(struct nlm_host *);
197 void		  nlmsvc_invalidate_all(void);
198 
199 static __inline__ struct inode *
200 nlmsvc_file_inode(struct nlm_file *file)
201 {
202 	return file->f_file->f_dentry->d_inode;
203 }
204 
205 /*
206  * Compare two host addresses (needs modifying for ipv6)
207  */
208 static __inline__ int
209 nlm_cmp_addr(const struct sockaddr_in *sin1, const struct sockaddr_in *sin2)
210 {
211 	return sin1->sin_addr.s_addr == sin2->sin_addr.s_addr;
212 }
213 
214 /*
215  * Compare two NLM locks.
216  * When the second lock is of type F_UNLCK, this acts like a wildcard.
217  */
218 static __inline__ int
219 nlm_compare_locks(const struct file_lock *fl1, const struct file_lock *fl2)
220 {
221 	return	fl1->fl_pid   == fl2->fl_pid
222 	     && fl1->fl_owner == fl2->fl_owner
223 	     && fl1->fl_start == fl2->fl_start
224 	     && fl1->fl_end   == fl2->fl_end
225 	     &&(fl1->fl_type  == fl2->fl_type || fl2->fl_type == F_UNLCK);
226 }
227 
228 extern struct lock_manager_operations nlmsvc_lock_operations;
229 
230 #endif /* __KERNEL__ */
231 
232 #endif /* LINUX_LOCKD_LOCKD_H */
233