xref: /freebsd/sys/nfs/nfs_lock.h (revision 6472ac3d8a86336899b6cfb789a4cd9897e3fab5)
1 /*-
2  * Copyright (c) 1998 Berkeley Software Design, Inc. All rights reserved.
3  * Redistribution and use in source and binary forms, with or without
4  * modification, are permitted provided that the following conditions
5  * are met:
6  * 1. Redistributions of source code must retain the above copyright
7  *    notice, this list of conditions and the following disclaimer.
8  * 2. Redistributions in binary form must reproduce the above copyright
9  *    notice, this list of conditions and the following disclaimer in the
10  *    documentation and/or other materials provided with the distribution.
11  * 3. Berkeley Software Design Inc's name may not be used to endorse or
12  *    promote products derived from this software without specific prior
13  *    written permission.
14  *
15  * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  *
27  *      from nfs_lock.h,v 2.2 1998/04/28 19:38:41 don Exp
28  * $FreeBSD$
29  */
30 
31 /*
32  * lockd uses the nfssvc system call to get the unique kernel services it needs.
33  * It passes in a request structure with a version number at the start.
34  * This prevents libc from needing to change if the information passed
35  * between lockd and the kernel needs to change.
36  *
37  * If a structure changes, you must bump the version number.
38  */
39 
40 /*
41  * The fifo where the kernel writes requests for locks on remote NFS files,
42  * and where lockd reads these requests.
43  *
44  */
45 #define	_PATH_NFSLCKDEV	"nfslock"
46 
47 /*
48  * This structure is used to uniquely identify the process which originated
49  * a particular message to lockd.  A sequence number is used to differentiate
50  * multiple messages from the same process.  A process start time is used to
51  * detect the unlikely, but possible, event of the recycling of a pid.
52  */
53 struct lockd_msg_ident {
54 	pid_t		pid;            /* The process ID. */
55 	struct timeval	pid_start;	/* Start time of process id */
56 	int		msg_seq;	/* Sequence number of message */
57 };
58 
59 #define LOCKD_MSG_VERSION	3
60 
61 /*
62  * The structure that the kernel hands us for each lock request.
63  */
64 typedef struct __lock_msg {
65 	TAILQ_ENTRY(__lock_msg)	lm_link;	/* internal linkage */
66 	int			lm_version;	/* which version is this */
67 	struct lockd_msg_ident	lm_msg_ident;	/* originator of the message */
68 	struct flock		lm_fl;             /* The lock request. */
69 	int			lm_wait;           /* The F_WAIT flag. */
70 	int			lm_getlk;		/* is this a F_GETLK request */
71 	struct sockaddr_storage lm_addr;		/* The address. */
72 	int			lm_nfsv3;		/* If NFS version 3. */
73 	size_t			lm_fh_len;		/* The file handle length. */
74 	struct xucred		lm_cred;		/* user cred for lock req */
75 	u_int8_t		lm_fh[NFSX_V3FHMAX];/* The file handle. */
76 } LOCKD_MSG;
77 
78 #define LOCKD_ANS_VERSION	1
79 
80 struct lockd_ans {
81 	int		la_vers;
82 	struct lockd_msg_ident	la_msg_ident;	/* originator of the message */
83 	int		la_errno;
84 	int		la_set_getlk_pid;		/* use returned pid */
85 	int		la_getlk_pid;		/* returned pid for F_GETLK */
86 };
87 
88 #ifdef _KERNEL
89 int	nfs_dolock(struct vop_advlock_args *ap);
90 extern	vop_advlock_t *nfs_advlock_p;
91 extern	vop_reclaim_t *nfs_reclaim_p;
92 #endif
93