xref: /freebsd/sys/nfs/nfs_lock.h (revision dd41de95a84d979615a2ef11df6850622bf6184e)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1998 Berkeley Software Design, Inc. All rights reserved.
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Berkeley Software Design Inc's name may not be used to endorse or
14  *    promote products derived from this software without specific prior
15  *    written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *      from nfs_lock.h,v 2.2 1998/04/28 19:38:41 don Exp
30  * $FreeBSD$
31  */
32 
33 /*
34  * lockd uses the nfssvc system call to get the unique kernel services it needs.
35  * It passes in a request structure with a version number at the start.
36  * This prevents libc from needing to change if the information passed
37  * between lockd and the kernel needs to change.
38  *
39  * If a structure changes, you must bump the version number.
40  */
41 
42 /*
43  * The fifo where the kernel writes requests for locks on remote NFS files,
44  * and where lockd reads these requests.
45  *
46  */
47 #define	_PATH_NFSLCKDEV	"nfslock"
48 
49 /*
50  * This structure is used to uniquely identify the process which originated
51  * a particular message to lockd.  A sequence number is used to differentiate
52  * multiple messages from the same process.  A process start time is used to
53  * detect the unlikely, but possible, event of the recycling of a pid.
54  */
55 struct lockd_msg_ident {
56 	pid_t		pid;            /* The process ID. */
57 	struct timeval	pid_start;	/* Start time of process id */
58 	int		msg_seq;	/* Sequence number of message */
59 };
60 
61 #define LOCKD_MSG_VERSION	3
62 
63 /*
64  * The structure that the kernel hands us for each lock request.
65  */
66 typedef struct __lock_msg {
67 	TAILQ_ENTRY(__lock_msg)	lm_link;	/* internal linkage */
68 	int			lm_version;	/* which version is this */
69 	struct lockd_msg_ident	lm_msg_ident;	/* originator of the message */
70 	struct flock		lm_fl;             /* The lock request. */
71 	int			lm_wait;           /* The F_WAIT flag. */
72 	int			lm_getlk;		/* is this a F_GETLK request */
73 	struct sockaddr_storage lm_addr;		/* The address. */
74 	int			lm_nfsv3;		/* If NFS version 3. */
75 	size_t			lm_fh_len;		/* The file handle length. */
76 	struct xucred		lm_cred;		/* user cred for lock req */
77 	u_int8_t		lm_fh[NFSX_V3FHMAX];/* The file handle. */
78 } LOCKD_MSG;
79 
80 #define LOCKD_ANS_VERSION	1
81 
82 struct lockd_ans {
83 	int		la_vers;
84 	struct lockd_msg_ident	la_msg_ident;	/* originator of the message */
85 	int		la_errno;
86 	int		la_set_getlk_pid;		/* use returned pid */
87 	int		la_getlk_pid;		/* returned pid for F_GETLK */
88 };
89 
90 #ifdef _KERNEL
91 int	nfs_dolock(struct vop_advlock_args *ap);
92 extern	vop_advlock_t *nfs_advlock_p;
93 extern	vop_reclaim_t *nfs_reclaim_p;
94 #endif
95