Made lockf advisory locking code generic (rather than ufs specific), and
use it in NFS. This is required both for diskless support and for POSIX compliance. Note: the support in NFS is only for the local node. Submitted by: based on work originally done by Yuval Yurom
This commit is contained in:
parent
712ca8b499
commit
92dc7331c9
Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=1960
@ -45,6 +45,7 @@ kern/kern_exec.c standard
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kern/kern_exit.c standard
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kern/kern_fork.c standard
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kern/kern_ktrace.c standard
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kern/kern_lockf.c standard
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kern/kern_malloc.c standard
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kern/kern_physio.c standard
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kern/kern_proc.c standard
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@ -277,7 +278,6 @@ ufs/ufs/ufs_bmap.c standard
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ufs/ufs/ufs_disksubr.c standard
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ufs/ufs/ufs_ihash.c standard
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ufs/ufs/ufs_inode.c standard
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ufs/ufs/ufs_lockf.c standard
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ufs/ufs/ufs_lookup.c standard
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ufs/ufs/ufs_quota.c standard
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ufs/ufs/ufs_vfsops.c standard
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|
797
sys/kern/kern_lockf.c
Normal file
797
sys/kern/kern_lockf.c
Normal file
@ -0,0 +1,797 @@
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/*
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* Copyright (c) 1982, 1986, 1989, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* Scooter Morris at Genentech Inc.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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||||
* notice, this list of conditions and the following disclaimer.
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||||
* 2. Redistributions in binary form must reproduce the above copyright
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||||
* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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||||
* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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||||
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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||||
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)ufs_lockf.c 8.3 (Berkeley) 1/6/94
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* $Id: ufs_lockf.c,v 1.2 1994/08/02 07:54:57 davidg Exp $
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*/
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/kernel.h>
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#include <sys/file.h>
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#include <sys/proc.h>
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#include <sys/vnode.h>
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#include <sys/malloc.h>
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#include <sys/fcntl.h>
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#include <sys/lockf.h>
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/*
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* This variable controls the maximum number of processes that will
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* be checked in doing deadlock detection.
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*/
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int maxlockdepth = MAXDEPTH;
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#ifdef LOCKF_DEBUG
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int lockf_debug = 0;
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#endif
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#define NOLOCKF (struct lockf *)0
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#define SELF 0x1
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#define OTHERS 0x2
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/*
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* Advisory record locking support
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*/
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int
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lf_advlock(ap, head, size)
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struct vop_advlock_args /* {
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struct vnode *a_vp;
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caddr_t a_id;
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int a_op;
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struct flock *a_fl;
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int a_flags;
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} */ *ap;
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struct lockf **head;
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u_quad_t size;
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{
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register struct flock *fl = ap->a_fl;
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register struct lockf *lock;
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off_t start, end;
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int error;
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/*
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* Avoid the common case of unlocking when inode has no locks.
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*/
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if (*head == (struct lockf *)0) {
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if (ap->a_op != F_SETLK) {
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fl->l_type = F_UNLCK;
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return (0);
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}
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}
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/*
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* Convert the flock structure into a start and end.
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*/
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switch (fl->l_whence) {
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case SEEK_SET:
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case SEEK_CUR:
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/*
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* Caller is responsible for adding any necessary offset
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* when SEEK_CUR is used.
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*/
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start = fl->l_start;
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break;
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case SEEK_END:
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start = size + fl->l_start;
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break;
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default:
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return (EINVAL);
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}
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if (start < 0)
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return (EINVAL);
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if (fl->l_len == 0)
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end = -1;
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else
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end = start + fl->l_len - 1;
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/*
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* Create the lockf structure
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*/
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MALLOC(lock, struct lockf *, sizeof *lock, M_LOCKF, M_WAITOK);
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lock->lf_start = start;
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lock->lf_end = end;
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lock->lf_id = ap->a_id;
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lock->lf_head = head;
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lock->lf_type = fl->l_type;
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lock->lf_next = (struct lockf *)0;
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lock->lf_block = (struct lockf *)0;
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lock->lf_flags = ap->a_flags;
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/*
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* Do the requested operation.
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*/
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switch(ap->a_op) {
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case F_SETLK:
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return (lf_setlock(lock));
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case F_UNLCK:
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error = lf_clearlock(lock);
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FREE(lock, M_LOCKF);
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return (error);
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case F_GETLK:
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error = lf_getlock(lock, fl);
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FREE(lock, M_LOCKF);
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return (error);
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default:
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free(lock, M_LOCKF);
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return (EINVAL);
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}
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/* NOTREACHED */
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}
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/*
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* Set a byte-range lock.
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*/
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int
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lf_setlock(lock)
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register struct lockf *lock;
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{
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register struct lockf *block;
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struct lockf **head = lock->lf_head;
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struct lockf **prev, *overlap, *ltmp;
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static char lockstr[] = "lockf";
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int ovcase, priority, needtolink, error;
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#ifdef LOCKF_DEBUG
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if (lockf_debug & 1)
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lf_print("lf_setlock", lock);
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#endif /* LOCKF_DEBUG */
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/*
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* Set the priority
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*/
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priority = PLOCK;
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if (lock->lf_type == F_WRLCK)
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priority += 4;
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priority |= PCATCH;
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/*
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* Scan lock list for this file looking for locks that would block us.
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*/
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while (block = lf_getblock(lock)) {
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/*
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* Free the structure and return if nonblocking.
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*/
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if ((lock->lf_flags & F_WAIT) == 0) {
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FREE(lock, M_LOCKF);
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return (EAGAIN);
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}
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/*
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* We are blocked. Since flock style locks cover
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* the whole file, there is no chance for deadlock.
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* For byte-range locks we must check for deadlock.
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*
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* Deadlock detection is done by looking through the
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* wait channels to see if there are any cycles that
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* involve us. MAXDEPTH is set just to make sure we
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* do not go off into neverland.
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*/
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if ((lock->lf_flags & F_POSIX) &&
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(block->lf_flags & F_POSIX)) {
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register struct proc *wproc;
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register struct lockf *waitblock;
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int i = 0;
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/* The block is waiting on something */
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wproc = (struct proc *)block->lf_id;
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while (wproc->p_wchan &&
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(wproc->p_wmesg == lockstr) &&
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(i++ < maxlockdepth)) {
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waitblock = (struct lockf *)wproc->p_wchan;
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/* Get the owner of the blocking lock */
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waitblock = waitblock->lf_next;
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if ((waitblock->lf_flags & F_POSIX) == 0)
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break;
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wproc = (struct proc *)waitblock->lf_id;
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if (wproc == (struct proc *)lock->lf_id) {
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free(lock, M_LOCKF);
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return (EDEADLK);
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}
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}
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}
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/*
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* For flock type locks, we must first remove
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* any shared locks that we hold before we sleep
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* waiting for an exclusive lock.
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*/
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if ((lock->lf_flags & F_FLOCK) &&
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lock->lf_type == F_WRLCK) {
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lock->lf_type = F_UNLCK;
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(void) lf_clearlock(lock);
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lock->lf_type = F_WRLCK;
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}
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/*
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* Add our lock to the blocked list and sleep until we're free.
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* Remember who blocked us (for deadlock detection).
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*/
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lock->lf_next = block;
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lf_addblock(block, lock);
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#ifdef LOCKF_DEBUG
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if (lockf_debug & 1) {
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lf_print("lf_setlock: blocking on", block);
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lf_printlist("lf_setlock", block);
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}
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#endif /* LOCKF_DEBUG */
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if (error = tsleep((caddr_t)lock, priority, lockstr, 0)) {
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/*
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* Delete ourselves from the waiting to lock list.
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*/
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for (block = lock->lf_next;
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block != NOLOCKF;
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block = block->lf_block) {
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if (block->lf_block != lock)
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continue;
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block->lf_block = block->lf_block->lf_block;
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break;
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}
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/*
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* If we did not find ourselves on the list, but
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* are still linked onto a lock list, then something
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* is very wrong.
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*/
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if (block == NOLOCKF && lock->lf_next != NOLOCKF)
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panic("lf_setlock: lost lock");
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free(lock, M_LOCKF);
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return (error);
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}
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}
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/*
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* No blocks!! Add the lock. Note that we will
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* downgrade or upgrade any overlapping locks this
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* process already owns.
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*
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* Skip over locks owned by other processes.
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* Handle any locks that overlap and are owned by ourselves.
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*/
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prev = head;
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block = *head;
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needtolink = 1;
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for (;;) {
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if (ovcase = lf_findoverlap(block, lock, SELF, &prev, &overlap))
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block = overlap->lf_next;
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/*
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* Six cases:
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* 0) no overlap
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* 1) overlap == lock
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* 2) overlap contains lock
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* 3) lock contains overlap
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* 4) overlap starts before lock
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* 5) overlap ends after lock
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*/
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switch (ovcase) {
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case 0: /* no overlap */
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if (needtolink) {
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*prev = lock;
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lock->lf_next = overlap;
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}
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break;
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case 1: /* overlap == lock */
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/*
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* If downgrading lock, others may be
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* able to acquire it.
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*/
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if (lock->lf_type == F_RDLCK &&
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overlap->lf_type == F_WRLCK)
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lf_wakelock(overlap);
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overlap->lf_type = lock->lf_type;
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FREE(lock, M_LOCKF);
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lock = overlap; /* for debug output below */
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break;
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case 2: /* overlap contains lock */
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/*
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* Check for common starting point and different types.
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*/
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if (overlap->lf_type == lock->lf_type) {
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free(lock, M_LOCKF);
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lock = overlap; /* for debug output below */
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break;
|
||||
}
|
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if (overlap->lf_start == lock->lf_start) {
|
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*prev = lock;
|
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lock->lf_next = overlap;
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overlap->lf_start = lock->lf_end + 1;
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} else
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lf_split(overlap, lock);
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lf_wakelock(overlap);
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break;
|
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|
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case 3: /* lock contains overlap */
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/*
|
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* If downgrading lock, others may be able to
|
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* acquire it, otherwise take the list.
|
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*/
|
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if (lock->lf_type == F_RDLCK &&
|
||||
overlap->lf_type == F_WRLCK) {
|
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lf_wakelock(overlap);
|
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} else {
|
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ltmp = lock->lf_block;
|
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lock->lf_block = overlap->lf_block;
|
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lf_addblock(lock, ltmp);
|
||||
}
|
||||
/*
|
||||
* Add the new lock if necessary and delete the overlap.
|
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*/
|
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if (needtolink) {
|
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*prev = lock;
|
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lock->lf_next = overlap->lf_next;
|
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prev = &lock->lf_next;
|
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needtolink = 0;
|
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} else
|
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*prev = overlap->lf_next;
|
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free(overlap, M_LOCKF);
|
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continue;
|
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|
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case 4: /* overlap starts before lock */
|
||||
/*
|
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* Add lock after overlap on the list.
|
||||
*/
|
||||
lock->lf_next = overlap->lf_next;
|
||||
overlap->lf_next = lock;
|
||||
overlap->lf_end = lock->lf_start - 1;
|
||||
prev = &lock->lf_next;
|
||||
lf_wakelock(overlap);
|
||||
needtolink = 0;
|
||||
continue;
|
||||
|
||||
case 5: /* overlap ends after lock */
|
||||
/*
|
||||
* Add the new lock before overlap.
|
||||
*/
|
||||
if (needtolink) {
|
||||
*prev = lock;
|
||||
lock->lf_next = overlap;
|
||||
}
|
||||
overlap->lf_start = lock->lf_end + 1;
|
||||
lf_wakelock(overlap);
|
||||
break;
|
||||
}
|
||||
break;
|
||||
}
|
||||
#ifdef LOCKF_DEBUG
|
||||
if (lockf_debug & 1) {
|
||||
lf_print("lf_setlock: got the lock", lock);
|
||||
lf_printlist("lf_setlock", lock);
|
||||
}
|
||||
#endif /* LOCKF_DEBUG */
|
||||
return (0);
|
||||
}
|
||||
|
||||
/*
|
||||
* Remove a byte-range lock on an inode.
|
||||
*
|
||||
* Generally, find the lock (or an overlap to that lock)
|
||||
* and remove it (or shrink it), then wakeup anyone we can.
|
||||
*/
|
||||
int
|
||||
lf_clearlock(unlock)
|
||||
register struct lockf *unlock;
|
||||
{
|
||||
struct lockf **head = unlock->lf_head;
|
||||
register struct lockf *lf = *head;
|
||||
struct lockf *overlap, **prev;
|
||||
int ovcase;
|
||||
|
||||
if (lf == NOLOCKF)
|
||||
return (0);
|
||||
#ifdef LOCKF_DEBUG
|
||||
if (unlock->lf_type != F_UNLCK)
|
||||
panic("lf_clearlock: bad type");
|
||||
if (lockf_debug & 1)
|
||||
lf_print("lf_clearlock", unlock);
|
||||
#endif /* LOCKF_DEBUG */
|
||||
prev = head;
|
||||
while (ovcase = lf_findoverlap(lf, unlock, SELF, &prev, &overlap)) {
|
||||
/*
|
||||
* Wakeup the list of locks to be retried.
|
||||
*/
|
||||
lf_wakelock(overlap);
|
||||
|
||||
switch (ovcase) {
|
||||
|
||||
case 1: /* overlap == lock */
|
||||
*prev = overlap->lf_next;
|
||||
FREE(overlap, M_LOCKF);
|
||||
break;
|
||||
|
||||
case 2: /* overlap contains lock: split it */
|
||||
if (overlap->lf_start == unlock->lf_start) {
|
||||
overlap->lf_start = unlock->lf_end + 1;
|
||||
break;
|
||||
}
|
||||
lf_split(overlap, unlock);
|
||||
overlap->lf_next = unlock->lf_next;
|
||||
break;
|
||||
|
||||
case 3: /* lock contains overlap */
|
||||
*prev = overlap->lf_next;
|
||||
lf = overlap->lf_next;
|
||||
free(overlap, M_LOCKF);
|
||||
continue;
|
||||
|
||||
case 4: /* overlap starts before lock */
|
||||
overlap->lf_end = unlock->lf_start - 1;
|
||||
prev = &overlap->lf_next;
|
||||
lf = overlap->lf_next;
|
||||
continue;
|
||||
|
||||
case 5: /* overlap ends after lock */
|
||||
overlap->lf_start = unlock->lf_end + 1;
|
||||
break;
|
||||
}
|
||||
break;
|
||||
}
|
||||
#ifdef LOCKF_DEBUG
|
||||
if (lockf_debug & 1)
|
||||
lf_printlist("lf_clearlock", unlock);
|
||||
#endif /* LOCKF_DEBUG */
|
||||
return (0);
|
||||
}
|
||||
|
||||
/*
|
||||
* Check whether there is a blocking lock,
|
||||
* and if so return its process identifier.
|
||||
*/
|
||||
int
|
||||
lf_getlock(lock, fl)
|
||||
register struct lockf *lock;
|
||||
register struct flock *fl;
|
||||
{
|
||||
register struct lockf *block;
|
||||
|
||||
#ifdef LOCKF_DEBUG
|
||||
if (lockf_debug & 1)
|
||||
lf_print("lf_getlock", lock);
|
||||
#endif /* LOCKF_DEBUG */
|
||||
|
||||
if (block = lf_getblock(lock)) {
|
||||
fl->l_type = block->lf_type;
|
||||
fl->l_whence = SEEK_SET;
|
||||
fl->l_start = block->lf_start;
|
||||
if (block->lf_end == -1)
|
||||
fl->l_len = 0;
|
||||
else
|
||||
fl->l_len = block->lf_end - block->lf_start + 1;
|
||||
if (block->lf_flags & F_POSIX)
|
||||
fl->l_pid = ((struct proc *)(block->lf_id))->p_pid;
|
||||
else
|
||||
fl->l_pid = -1;
|
||||
} else {
|
||||
fl->l_type = F_UNLCK;
|
||||
}
|
||||
return (0);
|
||||
}
|
||||
|
||||
/*
|
||||
* Walk the list of locks for an inode and
|
||||
* return the first blocking lock.
|
||||
*/
|
||||
struct lockf *
|
||||
lf_getblock(lock)
|
||||
register struct lockf *lock;
|
||||
{
|
||||
struct lockf **prev, *overlap, *lf = *(lock->lf_head);
|
||||
int ovcase;
|
||||
|
||||
prev = lock->lf_head;
|
||||
while (ovcase = lf_findoverlap(lf, lock, OTHERS, &prev, &overlap)) {
|
||||
/*
|
||||
* We've found an overlap, see if it blocks us
|
||||
*/
|
||||
if ((lock->lf_type == F_WRLCK || overlap->lf_type == F_WRLCK))
|
||||
return (overlap);
|
||||
/*
|
||||
* Nope, point to the next one on the list and
|
||||
* see if it blocks us
|
||||
*/
|
||||
lf = overlap->lf_next;
|
||||
}
|
||||
return (NOLOCKF);
|
||||
}
|
||||
|
||||
/*
|
||||
* Walk the list of locks for an inode to
|
||||
* find an overlapping lock (if any).
|
||||
*
|
||||
* NOTE: this returns only the FIRST overlapping lock. There
|
||||
* may be more than one.
|
||||
*/
|
||||
int
|
||||
lf_findoverlap(lf, lock, type, prev, overlap)
|
||||
register struct lockf *lf;
|
||||
struct lockf *lock;
|
||||
int type;
|
||||
struct lockf ***prev;
|
||||
struct lockf **overlap;
|
||||
{
|
||||
off_t start, end;
|
||||
|
||||
*overlap = lf;
|
||||
if (lf == NOLOCKF)
|
||||
return (0);
|
||||
#ifdef LOCKF_DEBUG
|
||||
if (lockf_debug & 2)
|
||||
lf_print("lf_findoverlap: looking for overlap in", lock);
|
||||
#endif /* LOCKF_DEBUG */
|
||||
start = lock->lf_start;
|
||||
end = lock->lf_end;
|
||||
while (lf != NOLOCKF) {
|
||||
if (((type & SELF) && lf->lf_id != lock->lf_id) ||
|
||||
((type & OTHERS) && lf->lf_id == lock->lf_id)) {
|
||||
*prev = &lf->lf_next;
|
||||
*overlap = lf = lf->lf_next;
|
||||
continue;
|
||||
}
|
||||
#ifdef LOCKF_DEBUG
|
||||
if (lockf_debug & 2)
|
||||
lf_print("\tchecking", lf);
|
||||
#endif /* LOCKF_DEBUG */
|
||||
/*
|
||||
* OK, check for overlap
|
||||
*
|
||||
* Six cases:
|
||||
* 0) no overlap
|
||||
* 1) overlap == lock
|
||||
* 2) overlap contains lock
|
||||
* 3) lock contains overlap
|
||||
* 4) overlap starts before lock
|
||||
* 5) overlap ends after lock
|
||||
*/
|
||||
if ((lf->lf_end != -1 && start > lf->lf_end) ||
|
||||
(end != -1 && lf->lf_start > end)) {
|
||||
/* Case 0 */
|
||||
#ifdef LOCKF_DEBUG
|
||||
if (lockf_debug & 2)
|
||||
printf("no overlap\n");
|
||||
#endif /* LOCKF_DEBUG */
|
||||
if ((type & SELF) && end != -1 && lf->lf_start > end)
|
||||
return (0);
|
||||
*prev = &lf->lf_next;
|
||||
*overlap = lf = lf->lf_next;
|
||||
continue;
|
||||
}
|
||||
if ((lf->lf_start == start) && (lf->lf_end == end)) {
|
||||
/* Case 1 */
|
||||
#ifdef LOCKF_DEBUG
|
||||
if (lockf_debug & 2)
|
||||
printf("overlap == lock\n");
|
||||
#endif /* LOCKF_DEBUG */
|
||||
return (1);
|
||||
}
|
||||
if ((lf->lf_start <= start) &&
|
||||
(end != -1) &&
|
||||
((lf->lf_end >= end) || (lf->lf_end == -1))) {
|
||||
/* Case 2 */
|
||||
#ifdef LOCKF_DEBUG
|
||||
if (lockf_debug & 2)
|
||||
printf("overlap contains lock\n");
|
||||
#endif /* LOCKF_DEBUG */
|
||||
return (2);
|
||||
}
|
||||
if (start <= lf->lf_start &&
|
||||
(end == -1 ||
|
||||
(lf->lf_end != -1 && end >= lf->lf_end))) {
|
||||
/* Case 3 */
|
||||
#ifdef LOCKF_DEBUG
|
||||
if (lockf_debug & 2)
|
||||
printf("lock contains overlap\n");
|
||||
#endif /* LOCKF_DEBUG */
|
||||
return (3);
|
||||
}
|
||||
if ((lf->lf_start < start) &&
|
||||
((lf->lf_end >= start) || (lf->lf_end == -1))) {
|
||||
/* Case 4 */
|
||||
#ifdef LOCKF_DEBUG
|
||||
if (lockf_debug & 2)
|
||||
printf("overlap starts before lock\n");
|
||||
#endif /* LOCKF_DEBUG */
|
||||
return (4);
|
||||
}
|
||||
if ((lf->lf_start > start) &&
|
||||
(end != -1) &&
|
||||
((lf->lf_end > end) || (lf->lf_end == -1))) {
|
||||
/* Case 5 */
|
||||
#ifdef LOCKF_DEBUG
|
||||
if (lockf_debug & 2)
|
||||
printf("overlap ends after lock\n");
|
||||
#endif /* LOCKF_DEBUG */
|
||||
return (5);
|
||||
}
|
||||
panic("lf_findoverlap: default");
|
||||
}
|
||||
return (0);
|
||||
}
|
||||
|
||||
/*
|
||||
* Add a lock to the end of the blocked list.
|
||||
*/
|
||||
void
|
||||
lf_addblock(lock, blocked)
|
||||
struct lockf *lock;
|
||||
struct lockf *blocked;
|
||||
{
|
||||
register struct lockf *lf;
|
||||
|
||||
if (blocked == NOLOCKF)
|
||||
return;
|
||||
#ifdef LOCKF_DEBUG
|
||||
if (lockf_debug & 2) {
|
||||
lf_print("addblock: adding", blocked);
|
||||
lf_print("to blocked list of", lock);
|
||||
}
|
||||
#endif /* LOCKF_DEBUG */
|
||||
if ((lf = lock->lf_block) == NOLOCKF) {
|
||||
lock->lf_block = blocked;
|
||||
return;
|
||||
}
|
||||
while (lf->lf_block != NOLOCKF)
|
||||
lf = lf->lf_block;
|
||||
lf->lf_block = blocked;
|
||||
return;
|
||||
}
|
||||
|
||||
/*
|
||||
* Split a lock and a contained region into
|
||||
* two or three locks as necessary.
|
||||
*/
|
||||
void
|
||||
lf_split(lock1, lock2)
|
||||
register struct lockf *lock1;
|
||||
register struct lockf *lock2;
|
||||
{
|
||||
register struct lockf *splitlock;
|
||||
|
||||
#ifdef LOCKF_DEBUG
|
||||
if (lockf_debug & 2) {
|
||||
lf_print("lf_split", lock1);
|
||||
lf_print("splitting from", lock2);
|
||||
}
|
||||
#endif /* LOCKF_DEBUG */
|
||||
/*
|
||||
* Check to see if spliting into only two pieces.
|
||||
*/
|
||||
if (lock1->lf_start == lock2->lf_start) {
|
||||
lock1->lf_start = lock2->lf_end + 1;
|
||||
lock2->lf_next = lock1;
|
||||
return;
|
||||
}
|
||||
if (lock1->lf_end == lock2->lf_end) {
|
||||
lock1->lf_end = lock2->lf_start - 1;
|
||||
lock2->lf_next = lock1->lf_next;
|
||||
lock1->lf_next = lock2;
|
||||
return;
|
||||
}
|
||||
/*
|
||||
* Make a new lock consisting of the last part of
|
||||
* the encompassing lock
|
||||
*/
|
||||
MALLOC(splitlock, struct lockf *, sizeof *splitlock, M_LOCKF, M_WAITOK);
|
||||
bcopy((caddr_t)lock1, (caddr_t)splitlock, sizeof *splitlock);
|
||||
splitlock->lf_start = lock2->lf_end + 1;
|
||||
splitlock->lf_block = NOLOCKF;
|
||||
lock1->lf_end = lock2->lf_start - 1;
|
||||
/*
|
||||
* OK, now link it in
|
||||
*/
|
||||
splitlock->lf_next = lock1->lf_next;
|
||||
lock2->lf_next = splitlock;
|
||||
lock1->lf_next = lock2;
|
||||
}
|
||||
|
||||
/*
|
||||
* Wakeup a blocklist
|
||||
*/
|
||||
void
|
||||
lf_wakelock(listhead)
|
||||
struct lockf *listhead;
|
||||
{
|
||||
register struct lockf *blocklist, *wakelock;
|
||||
|
||||
blocklist = listhead->lf_block;
|
||||
listhead->lf_block = NOLOCKF;
|
||||
while (blocklist != NOLOCKF) {
|
||||
wakelock = blocklist;
|
||||
blocklist = blocklist->lf_block;
|
||||
wakelock->lf_block = NOLOCKF;
|
||||
wakelock->lf_next = NOLOCKF;
|
||||
#ifdef LOCKF_DEBUG
|
||||
if (lockf_debug & 2)
|
||||
lf_print("lf_wakelock: awakening", wakelock);
|
||||
#endif /* LOCKF_DEBUG */
|
||||
wakeup((caddr_t)wakelock);
|
||||
}
|
||||
}
|
||||
|
||||
#ifdef LOCKF_DEBUG
|
||||
/*
|
||||
* Print out a lock.
|
||||
*/
|
||||
void
|
||||
lf_print(tag, lock)
|
||||
char *tag;
|
||||
register struct lockf *lock;
|
||||
{
|
||||
|
||||
printf("%s: lock 0x%lx for ", tag, lock);
|
||||
if (lock->lf_flags & F_POSIX)
|
||||
printf("proc %d", ((struct proc *)(lock->lf_id))->p_pid);
|
||||
else
|
||||
printf("id 0x%x", lock->lf_id);
|
||||
printf(" in ino %d on dev <%d, %d>, %s, start %d, end %d",
|
||||
lock->lf_inode->i_number,
|
||||
major(lock->lf_inode->i_dev),
|
||||
minor(lock->lf_inode->i_dev),
|
||||
lock->lf_type == F_RDLCK ? "shared" :
|
||||
lock->lf_type == F_WRLCK ? "exclusive" :
|
||||
lock->lf_type == F_UNLCK ? "unlock" :
|
||||
"unknown", lock->lf_start, lock->lf_end);
|
||||
if (lock->lf_block)
|
||||
printf(" block 0x%x\n", lock->lf_block);
|
||||
else
|
||||
printf("\n");
|
||||
}
|
||||
|
||||
void
|
||||
lf_printlist(tag, lock)
|
||||
char *tag;
|
||||
struct lockf *lock;
|
||||
{
|
||||
register struct lockf *lf;
|
||||
|
||||
printf("%s: Lock list for ino %d on dev <%d, %d>:\n",
|
||||
tag, lock->lf_inode->i_number,
|
||||
major(lock->lf_inode->i_dev),
|
||||
minor(lock->lf_inode->i_dev));
|
||||
for (lf = lock->lf_inode->i_lockf; lf; lf = lf->lf_next) {
|
||||
printf("\tlock 0x%lx for ", lf);
|
||||
if (lf->lf_flags & F_POSIX)
|
||||
printf("proc %d", ((struct proc *)(lf->lf_id))->p_pid);
|
||||
else
|
||||
printf("id 0x%x", lf->lf_id);
|
||||
printf(", %s, start %d, end %d",
|
||||
lf->lf_type == F_RDLCK ? "shared" :
|
||||
lf->lf_type == F_WRLCK ? "exclusive" :
|
||||
lf->lf_type == F_UNLCK ? "unlock" :
|
||||
"unknown", lf->lf_start, lf->lf_end);
|
||||
if (lf->lf_block)
|
||||
printf(" block 0x%x\n", lf->lf_block);
|
||||
else
|
||||
printf("\n");
|
||||
}
|
||||
}
|
||||
#endif /* LOCKF_DEBUG */
|
@ -34,7 +34,7 @@
|
||||
* SUCH DAMAGE.
|
||||
*
|
||||
* @(#)nfs_vnops.c 8.5 (Berkeley) 2/13/94
|
||||
* $Id$
|
||||
* $Id: nfs_vnops.c,v 1.3 1994/08/02 07:52:18 davidg Exp $
|
||||
*/
|
||||
|
||||
/*
|
||||
@ -54,6 +54,7 @@
|
||||
#include <sys/vnode.h>
|
||||
#include <sys/map.h>
|
||||
#include <sys/dirent.h>
|
||||
#include <sys/lockf.h>
|
||||
|
||||
#include <vm/vm.h>
|
||||
|
||||
@ -2204,8 +2205,14 @@ nfs_advlock(ap)
|
||||
int a_flags;
|
||||
} */ *ap;
|
||||
{
|
||||
register struct nfsnode *np = VTONFS(ap->a_vp);
|
||||
|
||||
return (EOPNOTSUPP);
|
||||
/*
|
||||
* The following kludge is to allow diskless support to work
|
||||
* until a real NFS lockd is implemented. Basically, just pretend
|
||||
* that this is a local lock.
|
||||
*/
|
||||
return (lf_advlock(ap, &(np->n_lockf), np->n_size));
|
||||
}
|
||||
|
||||
/*
|
||||
|
@ -34,7 +34,7 @@
|
||||
* SUCH DAMAGE.
|
||||
*
|
||||
* @(#)nfsnode.h 8.4 (Berkeley) 2/13/94
|
||||
* $Id$
|
||||
* $Id: nfsnode.h,v 1.2 1994/08/02 07:52:22 davidg Exp $
|
||||
*/
|
||||
|
||||
/*
|
||||
@ -66,6 +66,7 @@ struct nfsnode {
|
||||
time_t n_attrstamp; /* Time stamp for cached attributes */
|
||||
struct sillyrename *n_sillyrename; /* Ptr to silly rename struct */
|
||||
u_quad_t n_size; /* Current size of file */
|
||||
struct lockf *n_lockf; /* Locking record of file */
|
||||
int n_error; /* Save write error value */
|
||||
u_long n_direofoffset; /* Dir. EOF offset cache */
|
||||
time_t n_mtime; /* Prev modify time. */
|
||||
|
@ -34,7 +34,7 @@
|
||||
* SUCH DAMAGE.
|
||||
*
|
||||
* @(#)nfs_vnops.c 8.5 (Berkeley) 2/13/94
|
||||
* $Id$
|
||||
* $Id: nfs_vnops.c,v 1.3 1994/08/02 07:52:18 davidg Exp $
|
||||
*/
|
||||
|
||||
/*
|
||||
@ -54,6 +54,7 @@
|
||||
#include <sys/vnode.h>
|
||||
#include <sys/map.h>
|
||||
#include <sys/dirent.h>
|
||||
#include <sys/lockf.h>
|
||||
|
||||
#include <vm/vm.h>
|
||||
|
||||
@ -2204,8 +2205,14 @@ nfs_advlock(ap)
|
||||
int a_flags;
|
||||
} */ *ap;
|
||||
{
|
||||
register struct nfsnode *np = VTONFS(ap->a_vp);
|
||||
|
||||
return (EOPNOTSUPP);
|
||||
/*
|
||||
* The following kludge is to allow diskless support to work
|
||||
* until a real NFS lockd is implemented. Basically, just pretend
|
||||
* that this is a local lock.
|
||||
*/
|
||||
return (lf_advlock(ap, &(np->n_lockf), np->n_size));
|
||||
}
|
||||
|
||||
/*
|
||||
|
@ -34,7 +34,7 @@
|
||||
* SUCH DAMAGE.
|
||||
*
|
||||
* @(#)nfsnode.h 8.4 (Berkeley) 2/13/94
|
||||
* $Id$
|
||||
* $Id: nfsnode.h,v 1.2 1994/08/02 07:52:22 davidg Exp $
|
||||
*/
|
||||
|
||||
/*
|
||||
@ -66,6 +66,7 @@ struct nfsnode {
|
||||
time_t n_attrstamp; /* Time stamp for cached attributes */
|
||||
struct sillyrename *n_sillyrename; /* Ptr to silly rename struct */
|
||||
u_quad_t n_size; /* Current size of file */
|
||||
struct lockf *n_lockf; /* Locking record of file */
|
||||
int n_error; /* Save write error value */
|
||||
u_long n_direofoffset; /* Dir. EOF offset cache */
|
||||
time_t n_mtime; /* Prev modify time. */
|
||||
|
81
sys/sys/lockf.h
Normal file
81
sys/sys/lockf.h
Normal file
@ -0,0 +1,81 @@
|
||||
/*
|
||||
* 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
|
||||
* $Id: lockf.h,v 1.2 1994/08/02 07:54:50 davidg Exp $
|
||||
*/
|
||||
|
||||
/*
|
||||
* 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.
|
||||
*/
|
||||
struct lockf {
|
||||
short lf_flags; /* Lock semantics: F_POSIX, F_FLOCK, F_WAIT */
|
||||
short lf_type; /* Lock type: F_RDLCK, F_WRLCK */
|
||||
off_t lf_start; /* The byte # of the start of the lock */
|
||||
off_t lf_end; /* The byte # of the end of the lock (-1=EOF)*/
|
||||
caddr_t lf_id; /* The id of the resource holding the lock */
|
||||
struct lockf **lf_head; /* Back pointer to the head of the lockf list */
|
||||
struct lockf *lf_next; /* A pointer to the next lock on this inode */
|
||||
struct lockf *lf_block; /* The list of blocked locks */
|
||||
};
|
||||
|
||||
/* Maximum length of sleep chains to traverse to try and detect deadlock. */
|
||||
#define MAXDEPTH 50
|
||||
|
||||
__BEGIN_DECLS
|
||||
int lf_advlock __P((struct vop_advlock_args *, struct lockf **, u_quad_t));
|
||||
void lf_addblock __P((struct lockf *, struct lockf *));
|
||||
int lf_clearlock __P((struct lockf *));
|
||||
int lf_findoverlap __P((struct lockf *,
|
||||
struct lockf *, int, struct lockf ***, struct lockf **));
|
||||
struct lockf *
|
||||
lf_getblock __P((struct lockf *));
|
||||
int lf_getlock __P((struct lockf *, struct flock *));
|
||||
int lf_setlock __P((struct lockf *));
|
||||
void lf_split __P((struct lockf *, struct lockf *));
|
||||
void lf_wakelock __P((struct lockf *));
|
||||
__END_DECLS
|
||||
|
||||
#ifdef LOCKF_DEBUG
|
||||
extern int lockf_debug;
|
||||
|
||||
__BEGIN_DECLS
|
||||
void lf_print __P((char *, struct lockf *));
|
||||
void lf_printlist __P((char *, struct lockf *));
|
||||
__END_DECLS
|
||||
#endif
|
@ -31,7 +31,7 @@
|
||||
* SUCH DAMAGE.
|
||||
*
|
||||
* @(#)ffs_vnops.c 8.7 (Berkeley) 2/3/94
|
||||
* $Id$
|
||||
* $Id: ffs_vnops.c,v 1.2 1994/08/02 07:54:25 davidg Exp $
|
||||
*/
|
||||
|
||||
#include <sys/param.h>
|
||||
@ -46,13 +46,13 @@
|
||||
#include <sys/mount.h>
|
||||
#include <sys/vnode.h>
|
||||
#include <sys/malloc.h>
|
||||
#include <sys/lockf.h>
|
||||
|
||||
#include <vm/vm.h>
|
||||
|
||||
#include <miscfs/specfs/specdev.h>
|
||||
#include <miscfs/fifofs/fifo.h>
|
||||
|
||||
#include <ufs/ufs/lockf.h>
|
||||
#include <ufs/ufs/quota.h>
|
||||
#include <ufs/ufs/inode.h>
|
||||
#include <ufs/ufs/dir.h>
|
||||
|
@ -36,7 +36,7 @@
|
||||
* SUCH DAMAGE.
|
||||
*
|
||||
* @(#)ufs_vnops.c 8.10 (Berkeley) 4/1/94
|
||||
* $Id$
|
||||
* $Id: ufs_vnops.c,v 1.3 1994/08/02 07:55:03 davidg Exp $
|
||||
*/
|
||||
|
||||
#include <sys/param.h>
|
||||
@ -53,12 +53,12 @@
|
||||
#include <sys/vnode.h>
|
||||
#include <sys/malloc.h>
|
||||
#include <sys/dirent.h>
|
||||
#include <sys/lockf.h>
|
||||
|
||||
#include <vm/vm.h>
|
||||
|
||||
#include <miscfs/specfs/specdev.h>
|
||||
|
||||
#include <ufs/ufs/lockf.h>
|
||||
#include <ufs/ufs/quota.h>
|
||||
#include <ufs/ufs/inode.h>
|
||||
#include <ufs/ufs/dir.h>
|
||||
@ -1947,81 +1947,8 @@ ufs_advlock(ap)
|
||||
} */ *ap;
|
||||
{
|
||||
register struct inode *ip = VTOI(ap->a_vp);
|
||||
register struct flock *fl = ap->a_fl;
|
||||
register struct lockf *lock;
|
||||
off_t start, end;
|
||||
int error;
|
||||
|
||||
/*
|
||||
* Avoid the common case of unlocking when inode has no locks.
|
||||
*/
|
||||
if (ip->i_lockf == (struct lockf *)0) {
|
||||
if (ap->a_op != F_SETLK) {
|
||||
fl->l_type = F_UNLCK;
|
||||
return (0);
|
||||
}
|
||||
}
|
||||
/*
|
||||
* Convert the flock structure into a start and end.
|
||||
*/
|
||||
switch (fl->l_whence) {
|
||||
|
||||
case SEEK_SET:
|
||||
case SEEK_CUR:
|
||||
/*
|
||||
* Caller is responsible for adding any necessary offset
|
||||
* when SEEK_CUR is used.
|
||||
*/
|
||||
start = fl->l_start;
|
||||
break;
|
||||
|
||||
case SEEK_END:
|
||||
start = ip->i_size + fl->l_start;
|
||||
break;
|
||||
|
||||
default:
|
||||
return (EINVAL);
|
||||
}
|
||||
if (start < 0)
|
||||
return (EINVAL);
|
||||
if (fl->l_len == 0)
|
||||
end = -1;
|
||||
else
|
||||
end = start + fl->l_len - 1;
|
||||
/*
|
||||
* Create the lockf structure
|
||||
*/
|
||||
MALLOC(lock, struct lockf *, sizeof *lock, M_LOCKF, M_WAITOK);
|
||||
lock->lf_start = start;
|
||||
lock->lf_end = end;
|
||||
lock->lf_id = ap->a_id;
|
||||
lock->lf_inode = ip;
|
||||
lock->lf_type = fl->l_type;
|
||||
lock->lf_next = (struct lockf *)0;
|
||||
lock->lf_block = (struct lockf *)0;
|
||||
lock->lf_flags = ap->a_flags;
|
||||
/*
|
||||
* Do the requested operation.
|
||||
*/
|
||||
switch(ap->a_op) {
|
||||
case F_SETLK:
|
||||
return (lf_setlock(lock));
|
||||
|
||||
case F_UNLCK:
|
||||
error = lf_clearlock(lock);
|
||||
FREE(lock, M_LOCKF);
|
||||
return (error);
|
||||
|
||||
case F_GETLK:
|
||||
error = lf_getlock(lock, fl);
|
||||
FREE(lock, M_LOCKF);
|
||||
return (error);
|
||||
|
||||
default:
|
||||
free(lock, M_LOCKF);
|
||||
return (EINVAL);
|
||||
}
|
||||
/* NOTREACHED */
|
||||
return (lf_advlock(ap, &(ip->i_lockf), ip->i_size));
|
||||
}
|
||||
|
||||
/*
|
||||
|
Loading…
Reference in New Issue
Block a user