xref: /linux-6.15/include/linux/lockd/lockd.h (revision 757dea93)
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 rpc_clnt	*	h_rpcclnt;	/* RPC client to talk to peer */
43 	char *			h_name;		/* 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 	wait_queue_head_t	h_gracewait;	/* wait while reclaiming */
50 	struct rw_semaphore	h_rwsem;	/* Reboot recovery lock */
51 	u32			h_state;	/* pseudo-state counter */
52 	u32			h_nsmstate;	/* true remote NSM state */
53 	u32			h_pidcount;	/* Pseudopids */
54 	atomic_t		h_count;	/* reference count */
55 	struct mutex		h_mutex;	/* mutex for pmap binding */
56 	unsigned long		h_nextrebind;	/* next portmap call */
57 	unsigned long		h_expires;	/* eligible for GC */
58 	struct list_head	h_lockowners;	/* Lockowners for the client */
59 	spinlock_t		h_lock;
60 	struct list_head	h_granted;	/* Locks in GRANTED state */
61 	struct list_head	h_reclaim;	/* Locks in RECLAIM state */
62 	struct nsm_handle *	h_nsmhandle;	/* NSM status handle */
63 };
64 
65 struct nsm_handle {
66 	struct list_head	sm_link;
67 	atomic_t		sm_count;
68 	char *			sm_name;
69 	struct sockaddr_in	sm_addr;
70 	unsigned int		sm_monitored : 1,
71 				sm_sticky : 1;	/* don't unmonitor */
72 };
73 
74 /*
75  * Map an fl_owner_t into a unique 32-bit "pid"
76  */
77 struct nlm_lockowner {
78 	struct list_head list;
79 	atomic_t count;
80 
81 	struct nlm_host *host;
82 	fl_owner_t owner;
83 	uint32_t pid;
84 };
85 
86 struct nlm_wait;
87 
88 /*
89  * Memory chunk for NLM client RPC request.
90  */
91 #define NLMCLNT_OHSIZE		((__NEW_UTS_LEN) + 10u)
92 struct nlm_rqst {
93 	unsigned int		a_flags;	/* initial RPC task flags */
94 	struct nlm_host *	a_host;		/* host handle */
95 	struct nlm_args		a_args;		/* arguments */
96 	struct nlm_res		a_res;		/* result */
97 	struct nlm_block *	a_block;
98 	unsigned int		a_retries;	/* Retry count */
99 	u8			a_owner[NLMCLNT_OHSIZE];
100 };
101 
102 /*
103  * This struct describes a file held open by lockd on behalf of
104  * an NFS client.
105  */
106 struct nlm_file {
107 	struct hlist_node	f_list;		/* linked list */
108 	struct nfs_fh		f_handle;	/* NFS file handle */
109 	struct file *		f_file;		/* VFS file pointer */
110 	struct nlm_share *	f_shares;	/* DOS shares */
111 	struct list_head	f_blocks;	/* blocked locks */
112 	unsigned int		f_locks;	/* guesstimate # of locks */
113 	unsigned int		f_count;	/* reference count */
114 	struct mutex		f_mutex;	/* avoid concurrent access */
115 };
116 
117 /*
118  * This is a server block (i.e. a lock requested by some client which
119  * couldn't be granted because of a conflicting lock).
120  */
121 #define NLM_NEVER		(~(unsigned long) 0)
122 /* timeout on non-blocking call: */
123 #define NLM_TIMEOUT		(7 * HZ)
124 
125 struct nlm_block {
126 	struct kref		b_count;	/* Reference count */
127 	struct list_head	b_list;		/* linked list of all blocks */
128 	struct list_head	b_flist;	/* linked list (per file) */
129 	struct nlm_rqst	*	b_call;		/* RPC args & callback info */
130 	struct svc_serv *	b_daemon;	/* NLM service */
131 	struct nlm_host *	b_host;		/* host handle for RPC clnt */
132 	unsigned long		b_when;		/* next re-xmit */
133 	unsigned int		b_id;		/* block id */
134 	unsigned char		b_granted;	/* VFS granted lock */
135 	struct nlm_file *	b_file;		/* file in question */
136 	struct cache_req *	b_cache_req;	/* deferred request handling */
137 	struct file_lock *	b_fl;		/* set for GETLK */
138 	struct cache_deferred_req * b_deferred_req;
139 	unsigned int		b_flags;	/* block flags */
140 #define B_QUEUED		1	/* lock queued */
141 #define B_GOT_CALLBACK		2	/* got lock or conflicting lock */
142 #define B_TIMED_OUT		4	/* filesystem too slow to respond */
143 };
144 
145 /*
146  * Global variables
147  */
148 extern struct rpc_program	nlm_program;
149 extern struct svc_procedure	nlmsvc_procedures[];
150 #ifdef CONFIG_LOCKD_V4
151 extern struct svc_procedure	nlmsvc_procedures4[];
152 #endif
153 extern int			nlmsvc_grace_period;
154 extern unsigned long		nlmsvc_timeout;
155 extern int			nsm_use_hostnames;
156 
157 /*
158  * Lockd client functions
159  */
160 struct nlm_rqst * nlm_alloc_call(struct nlm_host *host);
161 void		  nlm_release_call(struct nlm_rqst *);
162 int		  nlm_async_call(struct nlm_rqst *, u32, const struct rpc_call_ops *);
163 int		  nlm_async_reply(struct nlm_rqst *, u32, const struct rpc_call_ops *);
164 struct nlm_wait * nlmclnt_prepare_block(struct nlm_host *host, struct file_lock *fl);
165 void		  nlmclnt_finish_block(struct nlm_wait *block);
166 int		  nlmclnt_block(struct nlm_wait *block, struct nlm_rqst *req, long timeout);
167 __be32		  nlmclnt_grant(const struct sockaddr_in *addr, const struct nlm_lock *);
168 void		  nlmclnt_recovery(struct nlm_host *);
169 int		  nlmclnt_reclaim(struct nlm_host *, struct file_lock *);
170 void		  nlmclnt_next_cookie(struct nlm_cookie *);
171 
172 /*
173  * Host cache
174  */
175 struct nlm_host * nlmclnt_lookup_host(const struct sockaddr_in *, int, int, const char *, int);
176 struct nlm_host * nlmsvc_lookup_host(struct svc_rqst *, const char *, int);
177 struct rpc_clnt * nlm_bind_host(struct nlm_host *);
178 void		  nlm_rebind_host(struct nlm_host *);
179 struct nlm_host * nlm_get_host(struct nlm_host *);
180 void		  nlm_release_host(struct nlm_host *);
181 void		  nlm_shutdown_hosts(void);
182 extern void	  nlm_host_rebooted(const struct sockaddr_in *, const char *, int, u32);
183 void		  nsm_release(struct nsm_handle *);
184 
185 
186 /*
187  * This is used in garbage collection and resource reclaim
188  * A return value != 0 means destroy the lock/block/share
189  */
190 typedef int	  (*nlm_host_match_fn_t)(struct nlm_host *cur, struct nlm_host *ref);
191 
192 /*
193  * Server-side lock handling
194  */
195 __be32		  nlmsvc_lock(struct svc_rqst *, struct nlm_file *,
196 					struct nlm_lock *, int, struct nlm_cookie *);
197 __be32		  nlmsvc_unlock(struct nlm_file *, struct nlm_lock *);
198 __be32		  nlmsvc_testlock(struct svc_rqst *, struct nlm_file *,
199 			struct nlm_lock *, struct nlm_lock *, struct nlm_cookie *);
200 __be32		  nlmsvc_cancel_blocked(struct nlm_file *, struct nlm_lock *);
201 unsigned long	  nlmsvc_retry_blocked(void);
202 void		  nlmsvc_traverse_blocks(struct nlm_host *, struct nlm_file *,
203 					nlm_host_match_fn_t match);
204 void		  nlmsvc_grant_reply(struct nlm_cookie *, __be32);
205 
206 /*
207  * File handling for the server personality
208  */
209 __be32		  nlm_lookup_file(struct svc_rqst *, struct nlm_file **,
210 					struct nfs_fh *);
211 void		  nlm_release_file(struct nlm_file *);
212 void		  nlmsvc_mark_resources(void);
213 void		  nlmsvc_free_host_resources(struct nlm_host *);
214 void		  nlmsvc_invalidate_all(void);
215 
216 static __inline__ struct inode *
217 nlmsvc_file_inode(struct nlm_file *file)
218 {
219 	return file->f_file->f_path.dentry->d_inode;
220 }
221 
222 /*
223  * Compare two host addresses (needs modifying for ipv6)
224  */
225 static __inline__ int
226 nlm_cmp_addr(const struct sockaddr_in *sin1, const struct sockaddr_in *sin2)
227 {
228 	return sin1->sin_addr.s_addr == sin2->sin_addr.s_addr;
229 }
230 
231 /*
232  * Compare two NLM locks.
233  * When the second lock is of type F_UNLCK, this acts like a wildcard.
234  */
235 static __inline__ int
236 nlm_compare_locks(const struct file_lock *fl1, const struct file_lock *fl2)
237 {
238 	return	fl1->fl_pid   == fl2->fl_pid
239 	     && fl1->fl_owner == fl2->fl_owner
240 	     && fl1->fl_start == fl2->fl_start
241 	     && fl1->fl_end   == fl2->fl_end
242 	     &&(fl1->fl_type  == fl2->fl_type || fl2->fl_type == F_UNLCK);
243 }
244 
245 extern struct lock_manager_operations nlmsvc_lock_operations;
246 
247 #endif /* __KERNEL__ */
248 
249 #endif /* LINUX_LOCKD_LOCKD_H */
250