1 /*
2  * linux/include/linux/lockd/lockd.h
3  *
4  * General-purpose lockd include file.
5  *
6  * Copyright (C) 1996 Olaf Kirch <okir@monad.swb.de>
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		"0.4"
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 svc_client *	h_exportent;	/* NFS client */
43 	struct rpc_clnt	*	h_rpcclnt;	/* RPC client to talk to peer */
44 	char			h_name[20];	/* remote hostname */
45 	u32			h_version;	/* interface version */
46 	unsigned short		h_proto;	/* transport proto */
47 	unsigned short		h_authflavor;	/* RPC authentication type */
48 	unsigned short		h_reclaiming : 1,
49 				h_inuse      : 1,
50 				h_killed     : 1,
51 				h_monitored  : 1;
52 	wait_queue_head_t	h_gracewait;	/* wait while reclaiming */
53 	u32			h_state;	/* pseudo-state counter */
54 	u32			h_nsmstate;	/* true remote NSM state */
55 	unsigned int		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 };
60 
61 /*
62  * Memory chunk for NLM client RPC request.
63  */
64 #define NLMCLNT_OHSIZE		(sizeof(system_utsname.nodename)+10)
65 struct nlm_rqst {
66 	unsigned int		a_flags;	/* initial RPC task flags */
67 	struct nlm_host *	a_host;		/* host handle */
68 	struct nlm_args		a_args;		/* arguments */
69 	struct nlm_res		a_res;		/* result */
70 	char			a_owner[NLMCLNT_OHSIZE];
71 };
72 
73 /*
74  * This struct describes a file held open by lockd on behalf of
75  * an NFS client.
76  */
77 struct nlm_file {
78 	struct nlm_file *	f_next;		/* linked list */
79 	struct nfs_fh		f_handle;	/* NFS file handle */
80 	struct file		f_file;		/* VFS file pointer */
81 	struct nlm_share *	f_shares;	/* DOS shares */
82 	struct nlm_block *	f_blocks;	/* blocked locks */
83 	unsigned int		f_locks;	/* guesstimate # of locks */
84 	unsigned int		f_count;	/* reference count */
85 	struct semaphore	f_sema;		/* avoid concurrent access */
86 	int		       	f_hash;		/* hash of f_handle */
87 };
88 
89 /*
90  * This is a server block (i.e. a lock requested by some client which
91  * couldn't be granted because of a conflicting lock).
92  */
93 #define NLM_NEVER		(~(unsigned long) 0)
94 struct nlm_block {
95 	struct nlm_block *	b_next;		/* linked list (all blocks) */
96 	struct nlm_block *	b_fnext;	/* linked list (per file) */
97 	struct nlm_rqst		b_call;		/* RPC args & callback info */
98 	struct svc_serv *	b_daemon;	/* NLM service */
99 	struct nlm_host *	b_host;		/* host handle for RPC clnt */
100 	unsigned long		b_when;		/* next re-xmit */
101 	unsigned int		b_id;		/* block id */
102 	unsigned char		b_queued;	/* re-queued */
103 	unsigned char		b_granted;	/* VFS granted lock */
104 	unsigned char		b_incall;	/* doing callback */
105 	unsigned char		b_done;		/* callback complete */
106 	struct nlm_file *	b_file;		/* file in question */
107 };
108 
109 /*
110  * Valid actions for nlmsvc_traverse_files
111  */
112 #define NLM_ACT_CHECK		0		/* check for locks */
113 #define NLM_ACT_MARK		1		/* mark & sweep */
114 #define NLM_ACT_UNLOCK		2		/* release all locks */
115 
116 /*
117  * Global variables
118  */
119 extern struct rpc_program	nlm_program;
120 extern struct svc_procedure	nlmsvc_procedures[];
121 #ifdef CONFIG_LOCKD_V4
122 extern struct svc_procedure	nlmsvc_procedures4[];
123 #endif
124 extern int			nlmsvc_grace_period;
125 extern unsigned long		nlmsvc_timeout;
126 
127 /*
128  * Lockd client functions
129  */
130 struct nlm_rqst * nlmclnt_alloc_call(void);
131 int		  nlmclnt_call(struct nlm_rqst *, u32);
132 int		  nlmclnt_async_call(struct nlm_rqst *, u32, rpc_action);
133 int		  nlmclnt_block(struct nlm_host *, struct file_lock *, u32 *);
134 int		  nlmclnt_cancel(struct nlm_host *, struct file_lock *);
135 u32		  nlmclnt_grant(struct nlm_lock *);
136 void		  nlmclnt_recovery(struct nlm_host *, u32);
137 int		  nlmclnt_reclaim(struct nlm_host *, struct file_lock *);
138 int		  nlmclnt_setgrantargs(struct nlm_rqst *, struct nlm_lock *);
139 void		  nlmclnt_freegrantargs(struct nlm_rqst *);
140 
141 /*
142  * Host cache
143  */
144 struct nlm_host * nlmclnt_lookup_host(struct sockaddr_in *, int, int);
145 struct nlm_host * nlmsvc_lookup_host(struct svc_rqst *);
146 struct nlm_host * nlm_lookup_host(struct svc_client *,
147 					struct sockaddr_in *, int, int);
148 struct rpc_clnt * nlm_bind_host(struct nlm_host *);
149 void		  nlm_rebind_host(struct nlm_host *);
150 struct nlm_host * nlm_get_host(struct nlm_host *);
151 void		  nlm_release_host(struct nlm_host *);
152 void		  nlm_shutdown_hosts(void);
153 
154 /*
155  * Server-side lock handling
156  */
157 int		  nlmsvc_async_call(struct nlm_rqst *, u32, rpc_action);
158 u32		  nlmsvc_lock(struct svc_rqst *, struct nlm_file *,
159 					struct nlm_lock *, int, struct nlm_cookie *);
160 u32		  nlmsvc_unlock(struct nlm_file *, struct nlm_lock *);
161 u32		  nlmsvc_testlock(struct nlm_file *, struct nlm_lock *,
162 					struct nlm_lock *);
163 u32		  nlmsvc_cancel_blocked(struct nlm_file *, struct nlm_lock *);
164 unsigned long	  nlmsvc_retry_blocked(void);
165 int		  nlmsvc_traverse_blocks(struct nlm_host *, struct nlm_file *,
166 					int action);
167 void	  nlmsvc_grant_reply(struct svc_rqst *, struct nlm_cookie *, u32);
168 
169 /*
170  * File handling for the server personality
171  */
172 u32		  nlm_lookup_file(struct svc_rqst *, struct nlm_file **,
173 					struct nfs_fh *);
174 void		  nlm_release_file(struct nlm_file *);
175 void		  nlmsvc_mark_resources(void);
176 void		  nlmsvc_free_host_resources(struct nlm_host *);
177 
178 static __inline__ struct inode *
nlmsvc_file_inode(struct nlm_file * file)179 nlmsvc_file_inode(struct nlm_file *file)
180 {
181 	return file->f_file.f_dentry->d_inode;
182 }
183 
184 /*
185  * Compare two host addresses (needs modifying for ipv6)
186  */
187 static __inline__ int
nlm_cmp_addr(struct sockaddr_in * sin1,struct sockaddr_in * sin2)188 nlm_cmp_addr(struct sockaddr_in *sin1, struct sockaddr_in *sin2)
189 {
190 	return sin1->sin_addr.s_addr == sin2->sin_addr.s_addr;
191 }
192 
193 /*
194  * Compare two NLM locks.
195  * When the second lock is of type F_UNLCK, this acts like a wildcard.
196  */
197 static __inline__ int
nlm_compare_locks(struct file_lock * fl1,struct file_lock * fl2)198 nlm_compare_locks(struct file_lock *fl1, struct file_lock *fl2)
199 {
200 	return	fl1->fl_pid   == fl2->fl_pid
201 	     && fl1->fl_start == fl2->fl_start
202 	     && fl1->fl_end   == fl2->fl_end
203 	     &&(fl1->fl_type  == fl2->fl_type || fl2->fl_type == F_UNLCK);
204 }
205 
206 #endif /* __KERNEL__ */
207 
208 #endif /* LINUX_LOCKD_LOCKD_H */
209