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 * $FreeBSD$ 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 be 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 #include <sys/_lock.h> 56 #include <sys/_rwlock.h> 57 #include <sys/_pctrie.h> 58 59 struct bufobj; 60 struct buf_ops; 61 62 extern struct buf_ops buf_ops_bio; 63 64 TAILQ_HEAD(buflists, buf); 65 66 /* A Buffer list & trie */ 67 struct bufv { 68 struct buflists bv_hd; /* Sorted blocklist */ 69 struct pctrie bv_root; /* Buf trie */ 70 int bv_cnt; /* Number of buffers */ 71 }; 72 73 typedef void b_strategy_t(struct bufobj *, struct buf *); 74 typedef int b_write_t(struct buf *); 75 typedef int b_sync_t(struct bufobj *, int waitfor); 76 typedef void b_bdflush_t(struct bufobj *, struct buf *); 77 78 struct buf_ops { 79 char *bop_name; 80 b_write_t *bop_write; 81 b_strategy_t *bop_strategy; 82 b_sync_t *bop_sync; 83 b_bdflush_t *bop_bdflush; 84 }; 85 86 #define BO_STRATEGY(bo, bp) ((bo)->bo_ops->bop_strategy((bo), (bp))) 87 #define BO_SYNC(bo, w) ((bo)->bo_ops->bop_sync((bo), (w))) 88 #define BO_WRITE(bo, bp) ((bo)->bo_ops->bop_write((bp))) 89 #define BO_BDFLUSH(bo, bp) ((bo)->bo_ops->bop_bdflush((bo), (bp))) 90 91 struct bufobj { 92 struct rwlock bo_lock; /* Lock which protects "i" things */ 93 struct buf_ops *bo_ops; /* - Buffer operations */ 94 struct vm_object *bo_object; /* v Place to store VM object */ 95 LIST_ENTRY(bufobj) bo_synclist; /* S dirty vnode list */ 96 void *bo_private; /* private pointer */ 97 struct vnode *__bo_vnode; /* 98 * XXX: This vnode pointer is here 99 * XXX: only to keep the syncer working 100 * XXX: for now. 101 */ 102 struct bufv bo_clean; /* i Clean buffers */ 103 struct bufv bo_dirty; /* i Dirty buffers */ 104 long bo_numoutput; /* i Writes in progress */ 105 u_int bo_flag; /* i Flags */ 106 int bo_bsize; /* - Block size for i/o */ 107 }; 108 109 /* 110 * XXX BO_ONWORKLST could be replaced with a check for NULL list elements 111 * in v_synclist. 112 */ 113 #define BO_ONWORKLST (1 << 0) /* On syncer work-list */ 114 #define BO_WWAIT (1 << 1) /* Wait for output to complete */ 115 #define BO_DEAD (1 << 2) /* Dead; only with INVARIANTS */ 116 117 #define BO_LOCKPTR(bo) (&(bo)->bo_lock) 118 #define BO_LOCK(bo) rw_wlock(BO_LOCKPTR((bo))) 119 #define BO_UNLOCK(bo) rw_wunlock(BO_LOCKPTR((bo))) 120 #define BO_RLOCK(bo) rw_rlock(BO_LOCKPTR((bo))) 121 #define BO_RUNLOCK(bo) rw_runlock(BO_LOCKPTR((bo))) 122 #define ASSERT_BO_WLOCKED(bo) rw_assert(BO_LOCKPTR((bo)), RA_WLOCKED) 123 #define ASSERT_BO_LOCKED(bo) rw_assert(BO_LOCKPTR((bo)), RA_LOCKED) 124 #define ASSERT_BO_UNLOCKED(bo) rw_assert(BO_LOCKPTR((bo)), RA_UNLOCKED) 125 126 void bufobj_wdrop(struct bufobj *bo); 127 void bufobj_wref(struct bufobj *bo); 128 void bufobj_wrefl(struct bufobj *bo); 129 int bufobj_invalbuf(struct bufobj *bo, int flags, int slpflag, int slptimeo); 130 int bufobj_wwait(struct bufobj *bo, int slpflag, int timeo); 131 int bufsync(struct bufobj *bo, int waitfor); 132 void bufbdflush(struct bufobj *bo, struct buf *bp); 133 134 #endif /* defined(_KERNEL) || defined(_KVM_VNODE) */ 135 #endif /* _SYS_BUFOBJ_H_ */ 136