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/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2004 Poul-Henning Kamp
* 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, 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*
* $FreeBSD$
*/
/*
* Architectural notes:
*
* bufobj is a new object which is what buffers hang from in the buffer
* cache.
*
* This used to be vnodes, but we need non-vnode code to be able
* to use the buffer cache as well, specifically geom classes like gbde,
* raid3 and raid5.
*
* All vnodes will contain a bufobj initially, but down the road we may
* want to only allocate bufobjs when they are needed. There could be a
* large number of vnodes in the system which wouldn't need a bufobj during
* their lifetime.
*
* The exact relationship to the vmobject is not determined at this point,
* it may in fact be that we find them to be two sides of the same object
* once things starts to crystalize.
*/
#ifndef _SYS_BUFOBJ_H_
#define _SYS_BUFOBJ_H_
#if defined(_KERNEL) || defined(_KVM_VNODE)
#include <sys/queue.h>
#include <sys/_lock.h>
#include <sys/_rwlock.h>
#include <sys/_pctrie.h>
struct bufobj;
struct buf_ops;
extern struct buf_ops buf_ops_bio;
TAILQ_HEAD(buflists, buf);
/* A Buffer list & trie */
struct bufv {
struct buflists bv_hd; /* Sorted blocklist */
struct pctrie bv_root; /* Buf trie */
int bv_cnt; /* Number of buffers */
};
typedef void b_strategy_t(struct bufobj *, struct buf *);
typedef int b_write_t(struct buf *);
typedef int b_sync_t(struct bufobj *, int waitfor);
typedef void b_bdflush_t(struct bufobj *, struct buf *);
struct buf_ops {
char *bop_name;
b_write_t *bop_write;
b_strategy_t *bop_strategy;
b_sync_t *bop_sync;
b_bdflush_t *bop_bdflush;
};
#define BO_STRATEGY(bo, bp) ((bo)->bo_ops->bop_strategy((bo), (bp)))
#define BO_SYNC(bo, w) ((bo)->bo_ops->bop_sync((bo), (w)))
#define BO_WRITE(bo, bp) ((bo)->bo_ops->bop_write((bp)))
#define BO_BDFLUSH(bo, bp) ((bo)->bo_ops->bop_bdflush((bo), (bp)))
/*
* Locking notes:
* 'S' is sync_mtx
* 'v' is the vnode lock which embeds the bufobj.
* '-' Constant and unchanging after initialization.
*/
struct bufobj {
struct rwlock bo_lock; /* Lock which protects "i" things */
struct buf_ops *bo_ops; /* - Buffer operations */
struct vm_object *bo_object; /* v Place to store VM object */
LIST_ENTRY(bufobj) bo_synclist; /* S dirty vnode list */
void *bo_private; /* private pointer */
struct bufv bo_clean; /* i Clean buffers */
struct bufv bo_dirty; /* i Dirty buffers */
long bo_numoutput; /* i Writes in progress */
u_int bo_flag; /* i Flags */
int bo_bsize; /* - Block size for i/o */
};
/*
* XXX BO_ONWORKLST could be replaced with a check for NULL list elements
* in v_synclist.
*/
#define BO_ONWORKLST (1 << 0) /* On syncer work-list */
#define BO_WWAIT (1 << 1) /* Wait for output to complete */
#define BO_DEAD (1 << 2) /* Dead; only with INVARIANTS */
#define BO_LOCKPTR(bo) (&(bo)->bo_lock)
#define BO_LOCK(bo) rw_wlock(BO_LOCKPTR((bo)))
#define BO_UNLOCK(bo) rw_wunlock(BO_LOCKPTR((bo)))
#define BO_RLOCK(bo) rw_rlock(BO_LOCKPTR((bo)))
#define BO_RUNLOCK(bo) rw_runlock(BO_LOCKPTR((bo)))
#define ASSERT_BO_WLOCKED(bo) rw_assert(BO_LOCKPTR((bo)), RA_WLOCKED)
#define ASSERT_BO_LOCKED(bo) rw_assert(BO_LOCKPTR((bo)), RA_LOCKED)
#define ASSERT_BO_UNLOCKED(bo) rw_assert(BO_LOCKPTR((bo)), RA_UNLOCKED)
void bufobj_wdrop(struct bufobj *bo);
void bufobj_wref(struct bufobj *bo);
void bufobj_wrefl(struct bufobj *bo);
int bufobj_invalbuf(struct bufobj *bo, int flags, int slpflag, int slptimeo);
int bufobj_wwait(struct bufobj *bo, int slpflag, int timeo);
int bufsync(struct bufobj *bo, int waitfor);
void bufbdflush(struct bufobj *bo, struct buf *bp);
#endif /* defined(_KERNEL) || defined(_KVM_VNODE) */
#endif /* _SYS_BUFOBJ_H_ */
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