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/*-
* 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>
struct bufobj;
struct buf_ops;
extern struct buf_ops buf_ops_bio;
TAILQ_HEAD(buflists, buf);
/* A Buffer splay list */
struct bufv {
struct buflists bv_hd; /* Sorted blocklist */
struct buf *bv_root; /* Buf splay tree */
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, struct thread *td);
struct buf_ops {
char *bop_name;
b_write_t *bop_write;
b_strategy_t *bop_strategy;
b_sync_t *bop_sync;
};
#define BO_STRATEGY(bo, bp) ((bo)->bo_ops->bop_strategy((bo), (bp)))
#define BO_SYNC(bo, w, td) ((bo)->bo_ops->bop_sync((bo), (w), (td)))
#define BO_WRITE(bo, bp) ((bo)->bo_ops->bop_write((bp)))
struct bufobj {
struct mtx *bo_mtx; /* Mutex which protects "i" things */
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 */
struct buf_ops *bo_ops; /* - Buffer operations */
int bo_bsize; /* - Block size for i/o */
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 vnode *__bo_vnode; /*
* XXX: This vnode pointer is here
* XXX: only to keep the syncer working
* XXX: for now.
*/
};
/*
* 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_NEEDSGIANT (1 << 2) /* Require giant for child buffers. */
#define BO_LOCK(bo) \
do { \
KASSERT((bo)->bo_mtx != NULL, ("No lock in bufobj")); \
mtx_lock((bo)->bo_mtx); \
} while (0)
#define BO_UNLOCK(bo) \
do { \
KASSERT((bo)->bo_mtx != NULL, ("No lock in bufobj")); \
mtx_unlock((bo)->bo_mtx); \
} while (0)
#define BO_MTX(bo) ((bo)->bo_mtx)
#define ASSERT_BO_LOCKED(bo) mtx_assert(bo->bo_mtx, MA_OWNED)
#define ASSERT_BO_UNLOCKED(bo) mtx_assert(bo->bo_mtx, MA_NOTOWNED)
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, struct thread *td, int slpflag, int slptimeo);
int bufobj_wwait(struct bufobj *bo, int slpflag, int timeo);
int bufsync(struct bufobj *bo, int waitfor, struct thread *td);
#endif /* defined(_KERNEL) || defined(_KVM_VNODE) */
#endif /* _SYS_BUFOBJ_H_ */
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