xref: /linux-6.15/include/linux/lockd/lockd.h (revision f15cbe6f)
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 hlist_node	h_hash;		/* doubly linked list */
41 	struct sockaddr_in	h_addr;		/* peer address */
42 	struct sockaddr_in	h_saddr;	/* our address (optional) */
43 	struct rpc_clnt	*	h_rpcclnt;	/* RPC client to talk to peer */
44 	char *			h_name;		/* remote hostname */
45 	u32			h_version;	/* interface version */
46 	unsigned short		h_proto;	/* transport proto */
47 	unsigned short		h_reclaiming : 1,
48 				h_server     : 1, /* server side, not client side */
49 				h_inuse      : 1;
50 	wait_queue_head_t	h_gracewait;	/* wait while reclaiming */
51 	struct rw_semaphore	h_rwsem;	/* Reboot recovery lock */
52 	u32			h_state;	/* pseudo-state counter */
53 	u32			h_nsmstate;	/* true remote NSM state */
54 	u32			h_pidcount;	/* Pseudopids */
55 	atomic_t		h_count;	/* reference count */
56 	struct mutex		h_mutex;	/* mutex for pmap binding */
57 	unsigned long		h_nextrebind;	/* next portmap call */
58 	unsigned long		h_expires;	/* eligible for GC */
59 	struct list_head	h_lockowners;	/* Lockowners for the client */
60 	spinlock_t		h_lock;
61 	struct list_head	h_granted;	/* Locks in GRANTED state */
62 	struct list_head	h_reclaim;	/* Locks in RECLAIM state */
63 	struct nsm_handle *	h_nsmhandle;	/* NSM status handle */
64 };
65 
66 struct nsm_handle {
67 	struct list_head	sm_link;
68 	atomic_t		sm_count;
69 	char *			sm_name;
70 	struct sockaddr_in	sm_addr;
71 	unsigned int		sm_monitored : 1,
72 				sm_sticky : 1;	/* don't unmonitor */
73 };
74 
75 /*
76  * Map an fl_owner_t into a unique 32-bit "pid"
77  */
78 struct nlm_lockowner {
79 	struct list_head list;
80 	atomic_t count;
81 
82 	struct nlm_host *host;
83 	fl_owner_t owner;
84 	uint32_t pid;
85 };
86 
87 struct nlm_wait;
88 
89 /*
90  * Memory chunk for NLM client RPC request.
91  */
92 #define NLMCLNT_OHSIZE		((__NEW_UTS_LEN) + 10u)
93 struct nlm_rqst {
94 	atomic_t		a_count;
95 	unsigned int		a_flags;	/* initial RPC task flags */
96 	struct nlm_host *	a_host;		/* host handle */
97 	struct nlm_args		a_args;		/* arguments */
98 	struct nlm_res		a_res;		/* result */
99 	struct nlm_block *	a_block;
100 	unsigned int		a_retries;	/* Retry count */
101 	u8			a_owner[NLMCLNT_OHSIZE];
102 };
103 
104 /*
105  * This struct describes a file held open by lockd on behalf of
106  * an NFS client.
107  */
108 struct nlm_file {
109 	struct hlist_node	f_list;		/* linked list */
110 	struct nfs_fh		f_handle;	/* NFS file handle */
111 	struct file *		f_file;		/* VFS file pointer */
112 	struct nlm_share *	f_shares;	/* DOS shares */
113 	struct list_head	f_blocks;	/* blocked locks */
114 	unsigned int		f_locks;	/* guesstimate # of locks */
115 	unsigned int		f_count;	/* reference count */
116 	struct mutex		f_mutex;	/* avoid concurrent access */
117 };
118 
119 /*
120  * This is a server block (i.e. a lock requested by some client which
121  * couldn't be granted because of a conflicting lock).
122  */
123 #define NLM_NEVER		(~(unsigned long) 0)
124 /* timeout on non-blocking call: */
125 #define NLM_TIMEOUT		(7 * HZ)
126 
127 struct nlm_block {
128 	struct kref		b_count;	/* Reference count */
129 	struct list_head	b_list;		/* linked list of all blocks */
130 	struct list_head	b_flist;	/* linked list (per file) */
131 	struct nlm_rqst	*	b_call;		/* RPC args & callback info */
132 	struct svc_serv *	b_daemon;	/* NLM service */
133 	struct nlm_host *	b_host;		/* host handle for RPC clnt */
134 	unsigned long		b_when;		/* next re-xmit */
135 	unsigned int		b_id;		/* block id */
136 	unsigned char		b_granted;	/* VFS granted lock */
137 	struct nlm_file *	b_file;		/* file in question */
138 	struct cache_req *	b_cache_req;	/* deferred request handling */
139 	struct file_lock *	b_fl;		/* set for GETLK */
140 	struct cache_deferred_req * b_deferred_req;
141 	unsigned int		b_flags;	/* block flags */
142 #define B_QUEUED		1	/* lock queued */
143 #define B_GOT_CALLBACK		2	/* got lock or conflicting lock */
144 #define B_TIMED_OUT		4	/* filesystem too slow to respond */
145 };
146 
147 /*
148  * Global variables
149  */
150 extern struct rpc_program	nlm_program;
151 extern struct svc_procedure	nlmsvc_procedures[];
152 #ifdef CONFIG_LOCKD_V4
153 extern struct svc_procedure	nlmsvc_procedures4[];
154 #endif
155 extern int			nlmsvc_grace_period;
156 extern unsigned long		nlmsvc_timeout;
157 extern int			nsm_use_hostnames;
158 
159 /*
160  * Lockd client functions
161  */
162 struct nlm_rqst * nlm_alloc_call(struct nlm_host *host);
163 void		  nlm_release_call(struct nlm_rqst *);
164 int		  nlm_async_call(struct nlm_rqst *, u32, const struct rpc_call_ops *);
165 int		  nlm_async_reply(struct nlm_rqst *, u32, const struct rpc_call_ops *);
166 struct nlm_wait * nlmclnt_prepare_block(struct nlm_host *host, struct file_lock *fl);
167 void		  nlmclnt_finish_block(struct nlm_wait *block);
168 int		  nlmclnt_block(struct nlm_wait *block, struct nlm_rqst *req, long timeout);
169 __be32		  nlmclnt_grant(const struct sockaddr_in *addr, const struct nlm_lock *);
170 void		  nlmclnt_recovery(struct nlm_host *);
171 int		  nlmclnt_reclaim(struct nlm_host *, struct file_lock *);
172 void		  nlmclnt_next_cookie(struct nlm_cookie *);
173 
174 /*
175  * Host cache
176  */
177 struct nlm_host  *nlmclnt_lookup_host(const struct sockaddr_in *sin,
178 					int proto, u32 version,
179 					const char *hostname,
180 					unsigned int hostname_len);
181 struct nlm_host  *nlmsvc_lookup_host(struct svc_rqst *, const char *,
182 					unsigned int);
183 struct rpc_clnt * nlm_bind_host(struct nlm_host *);
184 void		  nlm_rebind_host(struct nlm_host *);
185 struct nlm_host * nlm_get_host(struct nlm_host *);
186 void		  nlm_release_host(struct nlm_host *);
187 void		  nlm_shutdown_hosts(void);
188 extern void	  nlm_host_rebooted(const struct sockaddr_in *, const char *,
189 					unsigned int, u32);
190 void		  nsm_release(struct nsm_handle *);
191 
192 
193 /*
194  * This is used in garbage collection and resource reclaim
195  * A return value != 0 means destroy the lock/block/share
196  */
197 typedef int	  (*nlm_host_match_fn_t)(void *cur, struct nlm_host *ref);
198 
199 /*
200  * Server-side lock handling
201  */
202 __be32		  nlmsvc_lock(struct svc_rqst *, struct nlm_file *,
203 			      struct nlm_host *, struct nlm_lock *, int,
204 			      struct nlm_cookie *);
205 __be32		  nlmsvc_unlock(struct nlm_file *, struct nlm_lock *);
206 __be32		  nlmsvc_testlock(struct svc_rqst *, struct nlm_file *,
207 			struct nlm_host *, struct nlm_lock *,
208 			struct nlm_lock *, struct nlm_cookie *);
209 __be32		  nlmsvc_cancel_blocked(struct nlm_file *, struct nlm_lock *);
210 unsigned long	  nlmsvc_retry_blocked(void);
211 void		  nlmsvc_traverse_blocks(struct nlm_host *, struct nlm_file *,
212 					nlm_host_match_fn_t match);
213 void		  nlmsvc_grant_reply(struct nlm_cookie *, __be32);
214 
215 /*
216  * File handling for the server personality
217  */
218 __be32		  nlm_lookup_file(struct svc_rqst *, struct nlm_file **,
219 					struct nfs_fh *);
220 void		  nlm_release_file(struct nlm_file *);
221 void		  nlmsvc_mark_resources(void);
222 void		  nlmsvc_free_host_resources(struct nlm_host *);
223 void		  nlmsvc_invalidate_all(void);
224 
225 /*
226  * Cluster failover support
227  */
228 int           nlmsvc_unlock_all_by_sb(struct super_block *sb);
229 int           nlmsvc_unlock_all_by_ip(struct sockaddr *server_addr);
230 
231 static inline struct inode *nlmsvc_file_inode(struct nlm_file *file)
232 {
233 	return file->f_file->f_path.dentry->d_inode;
234 }
235 
236 /*
237  * Compare two host addresses (needs modifying for ipv6)
238  */
239 static inline int nlm_cmp_addr(const struct sockaddr_in *sin1,
240 			       const struct sockaddr_in *sin2)
241 {
242 	return sin1->sin_addr.s_addr == sin2->sin_addr.s_addr;
243 }
244 
245 /*
246  * Compare two NLM locks.
247  * When the second lock is of type F_UNLCK, this acts like a wildcard.
248  */
249 static inline int nlm_compare_locks(const struct file_lock *fl1,
250 				    const struct file_lock *fl2)
251 {
252 	return	fl1->fl_pid   == fl2->fl_pid
253 	     && fl1->fl_owner == fl2->fl_owner
254 	     && fl1->fl_start == fl2->fl_start
255 	     && fl1->fl_end   == fl2->fl_end
256 	     &&(fl1->fl_type  == fl2->fl_type || fl2->fl_type == F_UNLCK);
257 }
258 
259 extern struct lock_manager_operations nlmsvc_lock_operations;
260 
261 #endif /* __KERNEL__ */
262 
263 #endif /* LINUX_LOCKD_LOCKD_H */
264