1 /*- 2 * Copyright (c) 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Scooter Morris at Genentech Inc. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)lockf.h 8.1 (Berkeley) 6/11/93 33 * $FreeBSD$ 34 */ 35 36 #ifndef _SYS_LOCKF_H_ 37 #define _SYS_LOCKF_H_ 38 39 #include <sys/queue.h> 40 41 struct vop_advlock_args; 42 43 /* 44 * The lockf structure is a kernel structure which contains the information 45 * associated with a byte range lock. The lockf structures are linked into 46 * the inode structure. Locks are sorted by the starting byte of the lock for 47 * efficiency. 48 */ 49 TAILQ_HEAD(locklist, lockf); 50 51 struct lockf { 52 short lf_flags; /* Semantics: F_POSIX, F_FLOCK, F_WAIT */ 53 short lf_type; /* Lock type: F_RDLCK, F_WRLCK */ 54 off_t lf_start; /* Byte # of the start of the lock */ 55 off_t lf_end; /* Byte # of the end of the lock (-1=EOF) */ 56 caddr_t lf_id; /* Id of the resource holding the lock */ 57 struct lockf **lf_head; /* Back pointer to the head of the locf list */ 58 struct inode *lf_inode; /* Back pointer to the inode */ 59 struct lockf *lf_next; /* Pointer to the next lock on this inode */ 60 struct locklist lf_blkhd; /* List of requests blocked on this lock */ 61 TAILQ_ENTRY(lockf) lf_block;/* A request waiting for a lock */ 62 }; 63 64 /* Maximum length of sleep chains to traverse to try and detect deadlock. */ 65 #define MAXDEPTH 50 66 67 int lf_advlock(struct vop_advlock_args *, struct lockf **, u_quad_t); 68 69 #endif /* !_SYS_LOCKF_H_ */ 70