xref: /freebsd/sys/nfs/nfs_lock.h (revision a90b9d0159070121c221b966469c3e36d912bf82)
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  */
31 
32 /*
33  * lockd uses the nfssvc system call to get the unique kernel services it needs.
34  * It passes in a request structure with a version number at the start.
35  * This prevents libc from needing to change if the information passed
36  * between lockd and the kernel needs to change.
37  *
38  * If a structure changes, you must bump the version number.
39  */
40 
41 /*
42  * The fifo where the kernel writes requests for locks on remote NFS files,
43  * and where lockd reads these requests.
44  *
45  */
46 #define	_PATH_NFSLCKDEV	"nfslock"
47 
48 /*
49  * This structure is used to uniquely identify the process which originated
50  * a particular message to lockd.  A sequence number is used to differentiate
51  * multiple messages from the same process.  A process start time is used to
52  * detect the unlikely, but possible, event of the recycling of a pid.
53  */
54 struct lockd_msg_ident {
55 	pid_t		pid;            /* The process ID. */
56 	struct timeval	pid_start;	/* Start time of process id */
57 	int		msg_seq;	/* Sequence number of message */
58 };
59 
60 #define LOCKD_MSG_VERSION	3
61 
62 /*
63  * The structure that the kernel hands us for each lock request.
64  */
65 typedef struct __lock_msg {
66 	TAILQ_ENTRY(__lock_msg)	lm_link;	/* internal linkage */
67 	int			lm_version;	/* which version is this */
68 	struct lockd_msg_ident	lm_msg_ident;	/* originator of the message */
69 	struct flock		lm_fl;             /* The lock request. */
70 	int			lm_wait;           /* The F_WAIT flag. */
71 	int			lm_getlk;		/* is this a F_GETLK request */
72 	struct sockaddr_storage lm_addr;		/* The address. */
73 	int			lm_nfsv3;		/* If NFS version 3. */
74 	size_t			lm_fh_len;		/* The file handle length. */
75 	struct xucred		lm_cred;		/* user cred for lock req */
76 	u_int8_t		lm_fh[NFSX_V3FHMAX];/* The file handle. */
77 } LOCKD_MSG;
78 
79 #define LOCKD_ANS_VERSION	1
80 
81 struct lockd_ans {
82 	int		la_vers;
83 	struct lockd_msg_ident	la_msg_ident;	/* originator of the message */
84 	int		la_errno;
85 	int		la_set_getlk_pid;		/* use returned pid */
86 	int		la_getlk_pid;		/* returned pid for F_GETLK */
87 };
88 
89 #ifdef _KERNEL
90 int	nfs_dolock(struct vop_advlock_args *ap);
91 extern	vop_advlock_t *nfs_advlock_p;
92 extern	vop_reclaim_t *nfs_reclaim_p;
93 #endif
94