1/* 2 * Copyright (c) 2000-2007 Apple Inc. All rights reserved. 3 * 4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ 5 * 6 * This file contains Original Code and/or Modifications of Original Code 7 * as defined in and that are subject to the Apple Public Source License 8 * Version 2.0 (the 'License'). You may not use this file except in 9 * compliance with the License. The rights granted to you under the License 10 * may not be used to create, or enable the creation or redistribution of, 11 * unlawful or unlicensed copies of an Apple operating system, or to 12 * circumvent, violate, or enable the circumvention or violation of, any 13 * terms of an Apple operating system software license agreement. 14 * 15 * Please obtain a copy of the License at 16 * http://www.opensource.apple.com/apsl/ and read it before using this file. 17 * 18 * The Original Code and all software distributed under the License are 19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 23 * Please see the License for the specific language governing rights and 24 * limitations under the License. 25 * 26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ 27 */ 28/* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */ 29/* 30 * Copyright (c) 1982, 1986, 1989, 1993 31 * The Regents of the University of California. All rights reserved. 32 * (c) UNIX System Laboratories, Inc. 33 * All or some portions of this file are derived from material licensed 34 * to the University of California by American Telephone and Telegraph 35 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 36 * the permission of UNIX System Laboratories, Inc. 37 * 38 * Redistribution and use in source and binary forms, with or without 39 * modification, are permitted provided that the following conditions 40 * are met: 41 * 1. Redistributions of source code must retain the above copyright 42 * notice, this list of conditions and the following disclaimer. 43 * 2. Redistributions in binary form must reproduce the above copyright 44 * notice, this list of conditions and the following disclaimer in the 45 * documentation and/or other materials provided with the distribution. 46 * 3. All advertising materials mentioning features or use of this software 47 * must display the following acknowledgement: 48 * This product includes software developed by the University of 49 * California, Berkeley and its contributors. 50 * 4. Neither the name of the University nor the names of its contributors 51 * may be used to endorse or promote products derived from this software 52 * without specific prior written permission. 53 * 54 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 55 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 56 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 57 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 58 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 59 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 60 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 61 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 62 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 63 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 64 * SUCH DAMAGE. 65 * 66 * @(#)buf.h 8.9 (Berkeley) 3/30/95 67 */ 68 69#ifndef _SYS_BUF_INTERNAL_H_ 70#define _SYS_BUF_INTERNAL_H_ 71 72#include <sys/appleapiopts.h> 73 74#ifdef KERNEL 75#include <sys/queue.h> 76#include <sys/errno.h> 77#include <sys/vm.h> 78#include <sys/cdefs.h> 79#include <sys/buf.h> 80#include <sys/lock.h> 81 82 83#define NOLIST ((struct buf *)0x87654321) 84 85/* 86 * The buffer header describes an I/O operation in the kernel. 87 */ 88struct buf { 89 LIST_ENTRY(buf) b_hash; /* Hash chain. */ 90 LIST_ENTRY(buf) b_vnbufs; /* Buffer's associated vnode. */ 91 TAILQ_ENTRY(buf) b_freelist; /* Free list position if not active. */ 92 int b_timestamp; /* timestamp for queuing operation */ 93 long b_whichq; /* the free list the buffer belongs to */ 94 volatile long b_flags; /* B_* flags. */ 95 volatile long b_lflags; /* BL_BUSY | BL_WANTED flags... protected by buf_mtx */ 96 int b_error; /* errno value. */ 97 long b_bufsize; /* Allocated buffer size. */ 98 long b_bcount; /* Valid bytes in buffer. */ 99 long b_resid; /* Remaining I/O. */ 100 dev_t b_dev; /* Device associated with buffer. */ 101 uintptr_t b_datap; /* Memory, superblocks, indirect etc.*/ 102 daddr64_t b_lblkno; /* Logical block number. */ 103 daddr64_t b_blkno; /* Underlying physical block number. */ 104 void (*b_iodone)(buf_t, void *); /* Function to call upon completion. */ 105 vnode_t b_vp; /* File vnode for data, device vnode for metadata. */ 106 kauth_cred_t b_rcred; /* Read credentials reference. */ 107 kauth_cred_t b_wcred; /* Write credentials reference. */ 108 void * b_upl; /* Pointer to UPL */ 109 buf_t b_real_bp; /* used to track bp generated through cluster_bp */ 110 TAILQ_ENTRY(buf) b_act; /* Device driver queue when active */ 111 void * b_drvdata; /* Device driver private use */ 112 void * b_fsprivate; /* filesystem private use */ 113 void * b_transaction; /* journal private use */ 114 int b_dirtyoff; /* Offset in buffer of dirty region. */ 115 int b_dirtyend; /* Offset of end of dirty region. */ 116 int b_validoff; /* Offset in buffer of valid region. */ 117 int b_validend; /* Offset of end of valid region. */ 118 proc_t b_proc; /* Associated proc; NULL if kernel. */ 119#ifdef JOE_DEBUG 120 void * b_owner; 121 int b_tag; 122 void * b_lastbrelse; 123 int b_stackbrelse[6]; 124 int b_stackgetblk[6]; 125#endif 126}; 127 128 129/* cluster_io definitions for use with io bufs */ 130#define b_uploffset b_bufsize 131#define b_trans_head b_freelist.tqe_prev 132#define b_trans_next b_freelist.tqe_next 133#define b_iostate b_rcred 134#define b_cliodone b_wcred 135 136/* 137 * These flags are kept in b_lflags... 138 * buf_mtxp must be held before examining/updating 139 */ 140#define BL_BUSY 0x00000001 /* I/O in progress. */ 141#define BL_WANTED 0x00000002 /* Process wants this buffer. */ 142#define BL_IOBUF 0x00000004 /* buffer allocated via 'buf_alloc' */ 143#define BL_CALLDONE 0x00000008 /* callback routine on B_CALL bp has completed */ 144 145/* 146 * mask used by buf_flags... these are the readable external flags 147 */ 148#define BUF_X_RDFLAGS (B_PHYS | B_RAW | B_LOCKED | B_ASYNC | B_READ | B_WRITE | B_PAGEIO |\ 149 B_META | B_CLUSTER | B_DELWRI | B_FUA | B_PASSIVE) 150/* 151 * mask used by buf_clearflags/buf_setflags... these are the writable external flags 152 */ 153#define BUF_X_WRFLAGS (B_PHYS | B_RAW | B_LOCKED | B_ASYNC | B_READ | B_WRITE | B_PAGEIO |\ 154 B_NOCACHE | B_FUA | B_PASSIVE) 155 156/* 157 * These flags are kept in b_flags... access is lockless 158 * External flags are defined in buf.h and cannot overlap 159 * the internal flags 160 * 161 * these flags are internal... there definition may change 162 */ 163#define B_CACHE 0x00010000 /* getblk found us in the cache. */ 164#define B_DONE 0x00020000 /* I/O completed. */ 165#define B_INVAL 0x00040000 /* Does not contain valid info. */ 166#define B_ERROR 0x00080000 /* I/O error occurred. */ 167#define B_EINTR 0x00100000 /* I/O was interrupted */ 168#define B_AGE 0x00200000 /* Move to age queue when I/O done. */ 169#define B_FILTER 0x00400000 /* call b_iodone from biodone as an in-line filter */ 170#define B_CALL 0x00800000 /* Call b_iodone from biodone, assumes b_iodone consumes bp */ 171#define B_EOT 0x01000000 /* last buffer in a transaction list created by cluster_io */ 172#define B_WASDIRTY 0x02000000 /* page was found dirty in the VM cache */ 173#define B_HDRALLOC 0x04000000 /* zone allocated buffer header */ 174#define B_ZALLOC 0x08000000 /* b_datap is zalloc()ed */ 175/* 176 * private flags used by the journal layer 177 */ 178#define B_NORELSE 0x10000000 /* don't brelse() in bwrite() */ 179/* 180 * private flags used by by the cluster layer 181 */ 182#define B_NEED_IODONE 0x20000000 /* need biodone on the real_bp associated with a cluster_io */ 183#define B_COMMIT_UPL 0x40000000 /* commit/abort the UPL on I/O success/failure */ 184/* 185 * can we deprecate? 186 */ 187#define B_TAPE 0x80000000 /* Magnetic tape I/O. */ 188 189 190/* Flags to low-level allocation routines. */ 191#define B_CLRBUF 0x01 /* Request allocated buffer be cleared. */ 192#define B_SYNC 0x02 /* Do all allocations synchronously. */ 193#define B_NOBUFF 0x04 /* Do not allocate struct buf */ 194 195 196extern int niobuf_headers; /* The number of IO buffer headers for cluster IO */ 197extern int nbuf_headers; /* The number of buffer headers */ 198extern int max_nbuf_headers; /* The max number of buffer headers */ 199extern int nbuf_hashelements; /* The number of elements in bufhash */ 200extern struct buf *buf_headers; /* The buffer headers. */ 201 202 203/* 204 * Definitions for the buffer free lists. 205 */ 206#define BQUEUES 6 /* number of free buffer queues */ 207 208#define BQ_LOCKED 0 /* super-blocks &c */ 209#define BQ_LRU 1 /* lru, useful buffers */ 210#define BQ_AGE 2 /* rubbish */ 211#define BQ_EMPTY 3 /* buffer headers with no memory */ 212#define BQ_META 4 /* buffer containing metadata */ 213#define BQ_LAUNDRY 5 /* buffers that need cleaning */ 214 215 216__BEGIN_DECLS 217 218buf_t alloc_io_buf(vnode_t, int); 219void free_io_buf(buf_t); 220 221int allocbuf(struct buf *, int); 222void bufinit(void) __attribute__((section("__TEXT, initcode"))); 223 224void buf_setfilter(buf_t, void (*)(buf_t, void *), void *, void **, void **); 225 226/* 227 * Flags for buf_acquire 228 */ 229#define BAC_NOWAIT 0x01 /* Don't wait if buffer is busy */ 230#define BAC_REMOVE 0x02 /* Remove from free list once buffer is acquired */ 231#define BAC_SKIP_NONLOCKED 0x04 /* Don't return LOCKED buffers */ 232#define BAC_SKIP_LOCKED 0x08 /* Only return LOCKED buffers */ 233 234void buf_list_lock(void); 235void buf_list_unlock(void); 236 237void buf_biowait_callback(buf_t); 238 239void cluster_init(void) __attribute__((section("__TEXT, initcode"))); 240void buf_drop(buf_t); 241errno_t buf_acquire(buf_t, int, int, int); 242 243int count_busy_buffers(void); 244int count_lock_queue(void); 245 246 247__END_DECLS 248 249 250/* 251 * Stats on usefulness of the buffer cache 252 */ 253struct bufstats { 254 long bufs_incore; /* found incore */ 255 long bufs_busyincore; /* found incore. was busy */ 256 long bufs_vmhits; /* not incore. found in VM */ 257 long bufs_miss; /* not incore. not in VM */ 258 long bufs_sleeps; /* buffer starvation */ 259 long bufs_eblk; /* Calls to geteblk */ 260 long bufs_iobufmax; /* Max. number of IO buffers used */ 261 long bufs_iobufinuse; /* number of IO buffers in use */ 262 long bufs_iobufsleeps; /* IO buffer starvation */ 263}; 264 265#endif /* KERNEL */ 266#endif /* !_SYS_BUF_H_ */ 267