xref: /linux-6.15/include/linux/lockd/lockd.h (revision 4bedea94)
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/config.h>
15 #include <linux/in.h>
16 #include <linux/fs.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 	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 semaphore	h_sema;		/* 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 };
62 
63 /*
64  * Map an fl_owner_t into a unique 32-bit "pid"
65  */
66 struct nlm_lockowner {
67 	struct list_head list;
68 	atomic_t count;
69 
70 	struct nlm_host *host;
71 	fl_owner_t owner;
72 	uint32_t pid;
73 };
74 
75 struct nlm_wait;
76 
77 /*
78  * Memory chunk for NLM client RPC request.
79  */
80 #define NLMCLNT_OHSIZE		(sizeof(system_utsname.nodename)+10)
81 struct nlm_rqst {
82 	unsigned int		a_flags;	/* initial RPC task flags */
83 	struct nlm_host *	a_host;		/* host handle */
84 	struct nlm_args		a_args;		/* arguments */
85 	struct nlm_res		a_res;		/* result */
86 	struct nlm_wait *	a_block;
87 	char			a_owner[NLMCLNT_OHSIZE];
88 };
89 
90 /*
91  * This struct describes a file held open by lockd on behalf of
92  * an NFS client.
93  */
94 struct nlm_file {
95 	struct nlm_file *	f_next;		/* linked list */
96 	struct nfs_fh		f_handle;	/* NFS file handle */
97 	struct file *		f_file;		/* VFS file pointer */
98 	struct nlm_share *	f_shares;	/* DOS shares */
99 	struct nlm_block *	f_blocks;	/* blocked locks */
100 	unsigned int		f_locks;	/* guesstimate # of locks */
101 	unsigned int		f_count;	/* reference count */
102 	struct semaphore	f_sema;		/* avoid concurrent access */
103 	int		       	f_hash;		/* hash of f_handle */
104 };
105 
106 /*
107  * This is a server block (i.e. a lock requested by some client which
108  * couldn't be granted because of a conflicting lock).
109  */
110 #define NLM_NEVER		(~(unsigned long) 0)
111 struct nlm_block {
112 	struct nlm_block *	b_next;		/* linked list (all blocks) */
113 	struct nlm_block *	b_fnext;	/* linked list (per file) */
114 	struct nlm_rqst		b_call;		/* RPC args & callback info */
115 	struct svc_serv *	b_daemon;	/* NLM service */
116 	struct nlm_host *	b_host;		/* host handle for RPC clnt */
117 	unsigned long		b_when;		/* next re-xmit */
118 	unsigned int		b_id;		/* block id */
119 	unsigned char		b_queued;	/* re-queued */
120 	unsigned char		b_granted;	/* VFS granted lock */
121 	unsigned char		b_incall;	/* doing callback */
122 	unsigned char		b_done;		/* callback complete */
123 	struct nlm_file *	b_file;		/* file in question */
124 };
125 
126 /*
127  * Valid actions for nlmsvc_traverse_files
128  */
129 #define NLM_ACT_CHECK		0		/* check for locks */
130 #define NLM_ACT_MARK		1		/* mark & sweep */
131 #define NLM_ACT_UNLOCK		2		/* release all locks */
132 
133 /*
134  * Global variables
135  */
136 extern struct rpc_program	nlm_program;
137 extern struct svc_procedure	nlmsvc_procedures[];
138 #ifdef CONFIG_LOCKD_V4
139 extern struct svc_procedure	nlmsvc_procedures4[];
140 #endif
141 extern int			nlmsvc_grace_period;
142 extern unsigned long		nlmsvc_timeout;
143 
144 /*
145  * Lockd client functions
146  */
147 struct nlm_rqst * nlmclnt_alloc_call(void);
148 int		  nlmclnt_prepare_block(struct nlm_rqst *req, struct nlm_host *host, struct file_lock *fl);
149 void		  nlmclnt_finish_block(struct nlm_rqst *req);
150 long		  nlmclnt_block(struct nlm_rqst *req, long timeout);
151 int		  nlmclnt_cancel(struct nlm_host *, struct file_lock *);
152 u32		  nlmclnt_grant(struct nlm_lock *);
153 void		  nlmclnt_recovery(struct nlm_host *, u32);
154 int		  nlmclnt_reclaim(struct nlm_host *, struct file_lock *);
155 int		  nlmclnt_setgrantargs(struct nlm_rqst *, struct nlm_lock *);
156 void		  nlmclnt_freegrantargs(struct nlm_rqst *);
157 
158 /*
159  * Host cache
160  */
161 struct nlm_host * nlmclnt_lookup_host(struct sockaddr_in *, int, int);
162 struct nlm_host * nlmsvc_lookup_host(struct svc_rqst *);
163 struct nlm_host * nlm_lookup_host(int server, struct sockaddr_in *, int, int);
164 struct rpc_clnt * nlm_bind_host(struct nlm_host *);
165 void		  nlm_rebind_host(struct nlm_host *);
166 struct nlm_host * nlm_get_host(struct nlm_host *);
167 void		  nlm_release_host(struct nlm_host *);
168 void		  nlm_shutdown_hosts(void);
169 extern struct nlm_host *nlm_find_client(void);
170 
171 
172 /*
173  * Server-side lock handling
174  */
175 int		  nlmsvc_async_call(struct nlm_rqst *, u32, rpc_action);
176 u32		  nlmsvc_lock(struct svc_rqst *, struct nlm_file *,
177 					struct nlm_lock *, int, struct nlm_cookie *);
178 u32		  nlmsvc_unlock(struct nlm_file *, struct nlm_lock *);
179 u32		  nlmsvc_testlock(struct nlm_file *, struct nlm_lock *,
180 					struct nlm_lock *);
181 u32		  nlmsvc_cancel_blocked(struct nlm_file *, struct nlm_lock *);
182 unsigned long	  nlmsvc_retry_blocked(void);
183 int		  nlmsvc_traverse_blocks(struct nlm_host *, struct nlm_file *,
184 					int action);
185 void	  nlmsvc_grant_reply(struct svc_rqst *, struct nlm_cookie *, u32);
186 
187 /*
188  * File handling for the server personality
189  */
190 u32		  nlm_lookup_file(struct svc_rqst *, struct nlm_file **,
191 					struct nfs_fh *);
192 void		  nlm_release_file(struct nlm_file *);
193 void		  nlmsvc_mark_resources(void);
194 void		  nlmsvc_free_host_resources(struct nlm_host *);
195 void		  nlmsvc_invalidate_all(void);
196 
197 static __inline__ struct inode *
198 nlmsvc_file_inode(struct nlm_file *file)
199 {
200 	return file->f_file->f_dentry->d_inode;
201 }
202 
203 /*
204  * Compare two host addresses (needs modifying for ipv6)
205  */
206 static __inline__ int
207 nlm_cmp_addr(struct sockaddr_in *sin1, struct sockaddr_in *sin2)
208 {
209 	return sin1->sin_addr.s_addr == sin2->sin_addr.s_addr;
210 }
211 
212 /*
213  * Compare two NLM locks.
214  * When the second lock is of type F_UNLCK, this acts like a wildcard.
215  */
216 static __inline__ int
217 nlm_compare_locks(struct file_lock *fl1, struct file_lock *fl2)
218 {
219 	return	fl1->fl_pid   == fl2->fl_pid
220 	     && fl1->fl_start == fl2->fl_start
221 	     && fl1->fl_end   == fl2->fl_end
222 	     &&(fl1->fl_type  == fl2->fl_type || fl2->fl_type == F_UNLCK);
223 }
224 
225 extern struct lock_manager_operations nlmsvc_lock_operations;
226 
227 #endif /* __KERNEL__ */
228 
229 #endif /* LINUX_LOCKD_LOCKD_H */
230