bufobj.h revision 142079
1/*- 2 * Copyright (c) 2004 Poul-Henning Kamp 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD: head/sys/sys/bufobj.h 142079 2005-02-19 11:44:57Z phk $ 27 */ 28 29/* 30 * Architectural notes: 31 * 32 * bufobj is a new object which is what buffers hang from in the buffer 33 * cache. 34 * 35 * This used to be vnodes, but we need non-vnode code to be able 36 * to use the buffer cache as well, specifically geom classes like gbde, 37 * raid3 and raid5. 38 * 39 * All vnodes will contain a bufobj initially, but down the road we may 40 * want to only allocate bufobjs when they are needed. There could be a 41 * large number of vnodes in the system which wouldn't need a bufobj during 42 * their lifetime. 43 * 44 * The exact relationship to the vmobject is not determined at this point, 45 * it may in fact bee that we find them to be two sides of the same object 46 * once things starts to crystalize. 47 */ 48 49#ifndef _SYS_BUFOBJ_H_ 50#define _SYS_BUFOBJ_H_ 51 52#if defined(_KERNEL) || defined(_KVM_VNODE) 53 54#include <sys/queue.h> 55 56struct bufobj; 57struct buf_ops; 58 59extern struct buf_ops buf_ops_bio; 60 61TAILQ_HEAD(buflists, buf); 62 63/* A Buffer splay list */ 64struct bufv { 65 struct buflists bv_hd; /* Sorted blocklist */ 66 struct buf *bv_root; /* Buf splay tree */ 67 int bv_cnt; /* Number of buffers */ 68}; 69 70typedef void b_strategy_t(struct bufobj *, struct buf *); 71typedef int b_write_t(struct buf *); 72typedef int b_sync_t(struct bufobj *, int waitfor, struct thread *td); 73 74struct buf_ops { 75 char *bop_name; 76 b_write_t *bop_write; 77 b_strategy_t *bop_strategy; 78 b_sync_t *bop_sync; 79}; 80 81#define BO_STRATEGY(bo, bp) ((bo)->bo_ops->bop_strategy((bo), (bp))) 82#define BO_SYNC(bo, w, td) ((bo)->bo_ops->bop_sync((bo), (w), (td))) 83#define BO_WRITE(bo, bp) ((bo)->bo_ops->bop_write((bp))) 84 85struct bufobj { 86 struct mtx *bo_mtx; /* Mutex which protects "i" things */ 87 struct bufv bo_clean; /* i Clean buffers */ 88 struct bufv bo_dirty; /* i Dirty buffers */ 89 long bo_numoutput; /* i Writes in progress */ 90 u_int bo_flag; /* i Flags */ 91 struct buf_ops *bo_ops; /* - Buffer operations */ 92 int bo_bsize; /* - Block size for i/o */ 93 struct vm_object *bo_object; /* v Place to store VM object */ 94 LIST_ENTRY(bufobj) bo_synclist; /* S dirty vnode list */ 95 void *bo_private; /* private pointer */ 96 struct vnode *__bo_vnode; /* 97 * XXX: This vnode pointer is here 98 * XXX: only to keep the syncer working 99 * XXX: for now. 100 */ 101}; 102 103/* 104 * XXX BO_ONWORKLST could be replaced with a check for NULL list elements 105 * in v_synclist. 106 */ 107#define BO_ONWORKLST (1 << 0) /* On syncer work-list */ 108#define BO_WWAIT (1 << 1) /* Wait for output to complete */ 109 110#define BO_LOCK(bo) \ 111 do { \ 112 KASSERT (bo->bo_mtx != NULL, ("No lock in bufobj")); \ 113 mtx_lock((bo)->bo_mtx); \ 114 } while (0) 115 116#define BO_UNLOCK(bo) \ 117 do { \ 118 KASSERT (bo->bo_mtx != NULL, ("No lock in bufobj")); \ 119 mtx_unlock((bo)->bo_mtx); \ 120 } while (0) 121 122#define BO_MTX(bo) ((bo)->bo_mtx) 123#define ASSERT_BO_LOCKED(bo) mtx_assert(bo->bo_mtx, MA_OWNED) 124#define ASSERT_BO_UNLOCKED(bo) mtx_assert(bo->bo_mtx, MA_NOTOWNED) 125 126void bufobj_wdrop(struct bufobj *bo); 127void bufobj_wref(struct bufobj *bo); 128int bufobj_invalbuf(struct bufobj *bo, int flags, struct thread *td, int slpflag, int slptimeo); 129int bufobj_wwait(struct bufobj *bo, int slpflag, int timeo); 130int bufsync(struct bufobj *bo, int waitfor, struct thread *td); 131 132#endif /* defined(_KERNEL) || defined(_KVM_VNODE) */ 133#endif /* _SYS_BUFOBJ_H_ */ 134