freebsd-skq/sys/sys/lockf.h
2002-03-19 20:18:42 +00:00

83 lines
3.3 KiB
C

/*
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Scooter Morris at Genentech Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)lockf.h 8.1 (Berkeley) 6/11/93
* $FreeBSD$
*/
#ifndef _SYS_LOCKF_H_
#define _SYS_LOCKF_H_
#include <sys/queue.h>
struct vop_advlock_args;
#ifdef MALLOC_DECLARE
MALLOC_DECLARE(M_LOCKF);
#endif
/*
* The lockf structure is a kernel structure which contains the information
* associated with a byte range lock. The lockf structures are linked into
* the inode structure. Locks are sorted by the starting byte of the lock for
* efficiency.
*/
TAILQ_HEAD(locklist, lockf);
struct lockf {
short lf_flags; /* Semantics: F_POSIX, F_FLOCK, F_WAIT */
short lf_type; /* Lock type: F_RDLCK, F_WRLCK */
off_t lf_start; /* Byte # of the start of the lock */
off_t lf_end; /* Byte # of the end of the lock (-1=EOF) */
caddr_t lf_id; /* Id of the resource holding the lock */
struct lockf **lf_head; /* Back pointer to the head of the locf list */
struct inode *lf_inode; /* Back pointer to the inode */
struct lockf *lf_next; /* Pointer to the next lock on this inode */
struct locklist lf_blkhd; /* List of requests blocked on this lock */
TAILQ_ENTRY(lockf) lf_block;/* A request waiting for a lock */
};
/* Maximum length of sleep chains to traverse to try and detect deadlock. */
#define MAXDEPTH 50
int lf_advlock(struct vop_advlock_args *, struct lockf **, u_quad_t);
#ifdef LOCKF_DEBUG
void lf_print(char *, struct lockf *);
void lf_printlist(char *, struct lockf *);
#endif
#endif /* !_SYS_LOCKF_H_ */