freebsd-skq/sys/sys/lockmgr.h
mjg 28fa5eedfe vfs: implement v_holdcnt/v_usecount manipulation using atomic ops
Transitions 0->1 and 1->0 (which decide e.g. on putting the vnode on the free
list) of either counter are still guarded with vnode interlock.

Reviewed by:	kib (earlier version)
Tested by:	pho
2015-07-16 13:57:05 +00:00

201 lines
6.5 KiB
C

/*-
* Copyright (c) 2008 Attilio Rao <attilio@FreeBSD.org>
* All rights reserved.
*
* 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(s), this list of conditions and the following disclaimer as
* the first lines of this file unmodified other than the possible
* addition of one or more copyright notices.
* 2. Redistributions in binary form must reproduce the above copyright
* notice(s), this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``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 COPYRIGHT HOLDER(S) 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.
*
* $FreeBSD$
*/
#ifndef _SYS_LOCKMGR_H_
#define _SYS_LOCKMGR_H_
#include <sys/_lock.h>
#include <sys/_lockmgr.h>
#include <sys/_mutex.h>
#include <sys/_rwlock.h>
#define LK_SHARE 0x01
#define LK_SHARED_WAITERS 0x02
#define LK_EXCLUSIVE_WAITERS 0x04
#define LK_EXCLUSIVE_SPINNERS 0x08
#define LK_ALL_WAITERS \
(LK_SHARED_WAITERS | LK_EXCLUSIVE_WAITERS)
#define LK_FLAGMASK \
(LK_SHARE | LK_ALL_WAITERS | LK_EXCLUSIVE_SPINNERS)
#define LK_HOLDER(x) ((x) & ~LK_FLAGMASK)
#define LK_SHARERS_SHIFT 4
#define LK_SHARERS(x) (LK_HOLDER(x) >> LK_SHARERS_SHIFT)
#define LK_SHARERS_LOCK(x) ((x) << LK_SHARERS_SHIFT | LK_SHARE)
#define LK_ONE_SHARER (1 << LK_SHARERS_SHIFT)
#define LK_UNLOCKED LK_SHARERS_LOCK(0)
#define LK_KERNPROC ((uintptr_t)(-1) & ~LK_FLAGMASK)
#ifdef _KERNEL
#if !defined(LOCK_FILE) || !defined(LOCK_LINE)
#error "LOCK_FILE and LOCK_LINE not defined, include <sys/lock.h> before"
#endif
struct thread;
#define lk_recurse lock_object.lo_data
/*
* Function prototipes. Routines that start with an underscore are not part
* of the public interface and might be wrappered with a macro.
*/
int __lockmgr_args(struct lock *lk, u_int flags, struct lock_object *ilk,
const char *wmesg, int prio, int timo, const char *file, int line);
#if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
void _lockmgr_assert(const struct lock *lk, int what, const char *file, int line);
#endif
void _lockmgr_disown(struct lock *lk, const char *file, int line);
void lockallowrecurse(struct lock *lk);
void lockallowshare(struct lock *lk);
void lockdestroy(struct lock *lk);
void lockdisablerecurse(struct lock *lk);
void lockdisableshare(struct lock *lk);
void lockinit(struct lock *lk, int prio, const char *wmesg, int timo,
int flags);
#ifdef DDB
int lockmgr_chain(struct thread *td, struct thread **ownerp);
#endif
void lockmgr_printinfo(const struct lock *lk);
int lockstatus(const struct lock *lk);
/*
* As far as the ilk can be a static NULL pointer these functions need a
* strict prototype in order to safely use the lock_object member.
*/
static __inline int
_lockmgr_args(struct lock *lk, u_int flags, struct mtx *ilk, const char *wmesg,
int prio, int timo, const char *file, int line)
{
return (__lockmgr_args(lk, flags, (ilk != NULL) ? &ilk->lock_object :
NULL, wmesg, prio, timo, file, line));
}
static __inline int
_lockmgr_args_rw(struct lock *lk, u_int flags, struct rwlock *ilk,
const char *wmesg, int prio, int timo, const char *file, int line)
{
return (__lockmgr_args(lk, flags, (ilk != NULL) ? &ilk->lock_object :
NULL, wmesg, prio, timo, file, line));
}
/*
* Define aliases in order to complete lockmgr KPI.
*/
#define lockmgr(lk, flags, ilk) \
_lockmgr_args((lk), (flags), (ilk), LK_WMESG_DEFAULT, \
LK_PRIO_DEFAULT, LK_TIMO_DEFAULT, LOCK_FILE, LOCK_LINE)
#define lockmgr_args(lk, flags, ilk, wmesg, prio, timo) \
_lockmgr_args((lk), (flags), (ilk), (wmesg), (prio), (timo), \
LOCK_FILE, LOCK_LINE)
#define lockmgr_args_rw(lk, flags, ilk, wmesg, prio, timo) \
_lockmgr_args_rw((lk), (flags), (ilk), (wmesg), (prio), (timo), \
LOCK_FILE, LOCK_LINE)
#define lockmgr_disown(lk) \
_lockmgr_disown((lk), LOCK_FILE, LOCK_LINE)
#define lockmgr_recursed(lk) \
((lk)->lk_recurse != 0)
#define lockmgr_rw(lk, flags, ilk) \
_lockmgr_args_rw((lk), (flags), (ilk), LK_WMESG_DEFAULT, \
LK_PRIO_DEFAULT, LK_TIMO_DEFAULT, LOCK_FILE, LOCK_LINE)
#define lockmgr_waiters(lk) \
((lk)->lk_lock & LK_ALL_WAITERS)
#ifdef INVARIANTS
#define lockmgr_assert(lk, what) \
_lockmgr_assert((lk), (what), LOCK_FILE, LOCK_LINE)
#else
#define lockmgr_assert(lk, what)
#endif
/*
* Flags for lockinit().
*/
#define LK_INIT_MASK 0x0000FF
#define LK_CANRECURSE 0x000001
#define LK_NODUP 0x000002
#define LK_NOPROFILE 0x000004
#define LK_NOSHARE 0x000008
#define LK_NOWITNESS 0x000010
#define LK_QUIET 0x000020
#define LK_ADAPTIVE 0x000040
#define LK_IS_VNODE 0x000080 /* Tell WITNESS about a VNODE lock */
/*
* Additional attributes to be used in lockmgr().
*/
#define LK_EATTR_MASK 0x00FF00
#define LK_INTERLOCK 0x000100
#define LK_NOWAIT 0x000200
#define LK_RETRY 0x000400
#define LK_SLEEPFAIL 0x000800
#define LK_TIMELOCK 0x001000
#define LK_NODDLKTREAT 0x002000
#define LK_VNHELD 0x004000
/*
* Operations for lockmgr().
*/
#define LK_TYPE_MASK 0xFF0000
#define LK_DOWNGRADE 0x010000
#define LK_DRAIN 0x020000
#define LK_EXCLOTHER 0x040000
#define LK_EXCLUSIVE 0x080000
#define LK_RELEASE 0x100000
#define LK_SHARED 0x200000
#define LK_UPGRADE 0x400000
#define LK_TRYUPGRADE 0x800000
#define LK_TOTAL_MASK (LK_INIT_MASK | LK_EATTR_MASK | LK_TYPE_MASK)
/*
* Default values for lockmgr_args().
*/
#define LK_WMESG_DEFAULT (NULL)
#define LK_PRIO_DEFAULT (0)
#define LK_TIMO_DEFAULT (0)
/*
* Assertion flags.
*/
#if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
#define KA_LOCKED LA_LOCKED
#define KA_SLOCKED LA_SLOCKED
#define KA_XLOCKED LA_XLOCKED
#define KA_UNLOCKED LA_UNLOCKED
#define KA_RECURSED LA_RECURSED
#define KA_NOTRECURSED LA_NOTRECURSED
#endif
#endif /* _KERNEL */
#endif /* !_SYS_LOCKMGR_H_ */