1/* 2 * Copyright (c) 2000-2014 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#define NOLIST ((struct buf *)0x87654321) 83 84/* 85 * Attributes of an I/O to be used by lower layers 86 */ 87struct bufattr { 88#if CONFIG_PROTECT 89 struct cprotect *ba_cpentry; /* address of cp_entry */ 90 uint64_t ba_cp_file_off; /* rounded file offset. See buf_setcpoff() for more comments */ 91#endif 92 uint64_t ba_flags; /* flags. Some are only in-use on embedded devices */ 93}; 94 95/* 96 * The buffer header describes an I/O operation in the kernel. 97 */ 98struct buf { 99 LIST_ENTRY(buf) b_hash; /* Hash chain. */ 100 LIST_ENTRY(buf) b_vnbufs; /* Buffer's associated vnode. */ 101 TAILQ_ENTRY(buf) b_freelist; /* Free list position if not active. */ 102 int b_timestamp; /* timestamp for queuing operation */ 103 int b_whichq; /* the free list the buffer belongs to */ 104 volatile uint32_t b_flags; /* B_* flags. */ 105 volatile uint32_t b_lflags; /* BL_BUSY | BL_WANTED flags... protected by buf_mtx */ 106 int b_error; /* errno value. */ 107 int b_bufsize; /* Allocated buffer size. */ 108 int b_bcount; /* Valid bytes in buffer. */ 109 int b_resid; /* Remaining I/O. */ 110 dev_t b_dev; /* Device associated with buffer. */ 111 uintptr_t b_datap; /* Memory, superblocks, indirect etc.*/ 112 daddr64_t b_lblkno; /* Logical block number. */ 113 daddr64_t b_blkno; /* Underlying physical block number. */ 114 void (*b_iodone)(buf_t, void *); /* Function to call upon completion. */ 115 vnode_t b_vp; /* File vnode for data, device vnode for metadata. */ 116 kauth_cred_t b_rcred; /* Read credentials reference. */ 117 kauth_cred_t b_wcred; /* Write credentials reference. */ 118 void * b_upl; /* Pointer to UPL */ 119 buf_t b_real_bp; /* used to track bp generated through cluster_bp */ 120 TAILQ_ENTRY(buf) b_act; /* Device driver queue when active */ 121 void * b_drvdata; /* Device driver private use */ 122 void * b_fsprivate; /* filesystem private use */ 123 void * b_transaction; /* journal private use */ 124 int b_dirtyoff; /* Offset in buffer of dirty region. */ 125 int b_dirtyend; /* Offset of end of dirty region. */ 126 int b_validoff; /* Offset in buffer of valid region. */ 127 int b_validend; /* Offset of end of valid region. */ 128 129 /* store extra information related to redundancy of data, such as 130 * which redundancy copy to use, etc 131 */ 132 uint32_t b_redundancy_flags; 133 134 proc_t b_proc; /* Associated proc; NULL if kernel. */ 135#ifdef BUF_MAKE_PRIVATE 136 buf_t b_data_store; 137#endif 138 struct bufattr b_attr; 139#ifdef JOE_DEBUG 140 void * b_owner; 141 int b_tag; 142 void * b_lastbrelse; 143 void * b_stackbrelse[6]; 144 void * b_stackgetblk[6]; 145#endif 146}; 147 148extern vm_offset_t buf_kernel_addrperm; 149 150/* cluster_io definitions for use with io bufs */ 151#define b_uploffset b_bufsize 152#define b_orig b_freelist.tqe_prev 153#define b_shadow b_freelist.tqe_next 154#define b_shadow_ref b_validoff 155#ifdef BUF_MAKE_PRIVATE 156#define b_data_ref b_validend 157#endif 158#define b_trans_head b_freelist.tqe_prev 159#define b_trans_next b_freelist.tqe_next 160#define b_iostate b_rcred 161#define b_cliodone b_wcred 162 163/* 164 * These flags are kept in b_lflags... 165 * buf_mtxp must be held before examining/updating 166 */ 167#define BL_BUSY 0x00000001 /* I/O in progress. */ 168#define BL_WANTED 0x00000002 /* Process wants this buffer. */ 169#define BL_IOBUF 0x00000004 /* buffer allocated via 'buf_alloc' */ 170#define BL_WANTDEALLOC 0x00000010 /* buffer should be put on empty list when clean */ 171#define BL_SHADOW 0x00000020 172#define BL_EXTERNAL 0x00000040 173#define BL_WAITSHADOW 0x00000080 174#define BL_IOBUF_ALLOC 0x00000100 175#define BL_WANTED_REF 0x00000200 176 177/* 178 * Parameters for buffer cache garbage collection 179 */ 180#define BUF_STALE_THRESHHOLD 30 /* Collect if untouched in the last 30 seconds */ 181#define BUF_MAX_GC_BATCH_SIZE 64 /* Under a single grab of the lock */ 182 183/* 184 * mask used by buf_flags... these are the readable external flags 185 */ 186#define BUF_X_RDFLAGS (B_PHYS | B_RAW | B_LOCKED | B_ASYNC | B_READ | B_WRITE | B_PAGEIO |\ 187 B_META | B_CLUSTER | B_DELWRI | B_FUA | B_PASSIVE | B_IOSTREAMING |\ 188 B_ENCRYPTED_IO | B_STATICCONTENT) 189/* 190 * mask used by buf_clearflags/buf_setflags... these are the writable external flags 191 */ 192#define BUF_X_WRFLAGS (B_PHYS | B_RAW | B_LOCKED | B_ASYNC | B_READ | B_WRITE | B_PAGEIO |\ 193 B_NOCACHE | B_FUA | B_PASSIVE | B_IOSTREAMING) 194 195#if 0 196/* b_flags defined in buf.h */ 197#define B_WRITE 0x00000000 /* Write buffer (pseudo flag). */ 198#define B_READ 0x00000001 /* Read buffer. */ 199#define B_ASYNC 0x00000002 /* Start I/O, do not wait. */ 200#define B_NOCACHE 0x00000004 /* Do not cache block after use. */ 201#define B_DELWRI 0x00000008 /* Delay I/O until buffer reused. */ 202#define B_LOCKED 0x00000010 /* Locked in core (not reusable). */ 203#define B_PHYS 0x00000020 /* I/O to user memory. */ 204#define B_CLUSTER 0x00000040 /* UPL based I/O generated by cluster layer */ 205#define B_PAGEIO 0x00000080 /* Page in/out */ 206#define B_META 0x00000100 /* buffer contains meta-data. */ 207#define B_RAW 0x00000200 /* Set by physio for raw transfers. */ 208#define B_FUA 0x00000400 /* Write-through disk cache(if supported) */ 209#define B_PASSIVE 0x00000800 /* PASSIVE I/Os are ignored by THROTTLE I/O */ 210#define B_IOSTREAMING 0x00001000 /* sequential access pattern detected */ 211#define B_ENCRYPTED_IO 0x00004000 /* Encrypted I/O */ 212#define B_STATICCONTENT 0x00008000 /* Buffer is likely to remain unaltered */ 213#endif 214 215/* 216 * These flags are kept in b_flags... access is lockless 217 * External flags are defined in buf.h and cannot overlap 218 * the internal flags 219 * 220 * these flags are internal... there definition may change 221 */ 222#define B_CACHE 0x00010000 /* getblk found us in the cache. */ 223#define B_DONE 0x00020000 /* I/O completed. */ 224#define B_INVAL 0x00040000 /* Does not contain valid info. */ 225#define B_ERROR 0x00080000 /* I/O error occurred. */ 226#define B_EINTR 0x00100000 /* I/O was interrupted */ 227#define B_AGE 0x00200000 /* Move to age queue when I/O done. */ 228#define B_FILTER 0x00400000 /* call b_iodone from biodone as an in-line filter */ 229#define B_CALL 0x00800000 /* Call b_iodone from biodone, assumes b_iodone consumes bp */ 230#define B_EOT 0x01000000 /* last buffer in a transaction list created by cluster_io */ 231#define B_WASDIRTY 0x02000000 /* page was found dirty in the VM cache */ 232#define B_HDRALLOC 0x04000000 /* zone allocated buffer header */ 233#define B_ZALLOC 0x08000000 /* b_datap is zalloc()ed */ 234/* 235 * private flags used by the journal layer 236 */ 237#define B_NORELSE 0x10000000 /* don't brelse() in bwrite() */ 238/* 239 * private flags used by by the cluster layer 240 */ 241#define B_TWANTED 0x20000000 /* but_t that is part of a cluster level transaction is wanted */ 242#define B_COMMIT_UPL 0x40000000 /* commit/abort the UPL on I/O success/failure */ 243#define B_TDONE 0x80000000 /* buf_t that is part of a cluster level transaction has completed */ 244 245/* Flags to low-level allocation routines. */ 246#define B_CLRBUF 0x01 /* Request allocated buffer be cleared. */ 247#define B_SYNC 0x02 /* Do all allocations synchronously. */ 248#define B_NOBUFF 0x04 /* Do not allocate struct buf */ 249 250/* 251 * ba_flags (Buffer Attribute flags) 252 * Some of these may be in-use only on embedded devices. 253 */ 254#define BA_RAW_ENCRYPTED_IO 0x00000001 255#define BA_THROTTLED_IO 0x00000002 256#define BA_DELAYIDLESLEEP 0x00000004 /* Process is marked to delay idle sleep on disk IO */ 257#define BA_NOCACHE 0x00000008 258#define BA_META 0x00000010 259#define BA_GREEDY_MODE 0x00000020 /* High speed writes that consume more storage */ 260#define BA_QUICK_COMPLETE 0x00000040 /* Request quick completion at expense of storage efficiency */ 261#define BA_PASSIVE 0x00000080 262 263/* 264 * Note: IO_TIERs consume 0x0100, 0x0200, 0x0400, 0x0800 265 * These are now in-use by the I/O tiering system. 266 */ 267#define BA_IO_TIER_MASK 0x00000f00 268#define BA_IO_TIER_SHIFT 8 269 270#define BA_ISOCHRONOUS 0x00001000 /* device specific isochronous throughput to media */ 271 272 273#define GET_BUFATTR_IO_TIER(bap) ((bap->ba_flags & BA_IO_TIER_MASK) >> BA_IO_TIER_SHIFT) 274#define SET_BUFATTR_IO_TIER(bap, tier) \ 275do { \ 276 (bap)->ba_flags &= (~BA_IO_TIER_MASK); \ 277 (bap)->ba_flags |= (((tier) << BA_IO_TIER_SHIFT) & BA_IO_TIER_MASK); \ 278} while(0) 279 280extern int niobuf_headers; /* The number of IO buffer headers for cluster IO */ 281extern int nbuf_headers; /* The number of buffer headers */ 282extern int max_nbuf_headers; /* The max number of buffer headers */ 283extern int nbuf_hashelements; /* The number of elements in bufhash */ 284extern struct buf *buf_headers; /* The buffer headers. */ 285 286 287/* 288 * Definitions for the buffer free lists. 289 */ 290#define BQUEUES 6 /* number of free buffer queues */ 291 292#define BQ_LOCKED 0 /* super-blocks &c */ 293#define BQ_LRU 1 /* lru, useful buffers */ 294#define BQ_AGE 2 /* rubbish */ 295#define BQ_EMPTY 3 /* buffer headers with no memory */ 296#define BQ_META 4 /* buffer containing metadata */ 297#define BQ_LAUNDRY 5 /* buffers that need cleaning */ 298 299 300__BEGIN_DECLS 301 302buf_t buf_create_shadow_priv(buf_t bp, boolean_t force_copy, uintptr_t external_storage, void (*iodone)(buf_t, void *), void *arg); 303 304buf_t alloc_io_buf(vnode_t, int); 305void free_io_buf(buf_t); 306 307int allocbuf(struct buf *, int); 308void bufinit(void); 309 310/* 311 * Flags for buf_acquire 312 */ 313#define BAC_NOWAIT 0x01 /* Don't wait if buffer is busy */ 314#define BAC_REMOVE 0x02 /* Remove from free list once buffer is acquired */ 315#define BAC_SKIP_NONLOCKED 0x04 /* Don't return LOCKED buffers */ 316#define BAC_SKIP_LOCKED 0x08 /* Only return LOCKED buffers */ 317 318void buf_list_lock(void); 319void buf_list_unlock(void); 320 321void cluster_init(void); 322void buf_drop(buf_t); 323errno_t buf_acquire(buf_t, int, int, int); 324 325int count_busy_buffers(void); 326int count_lock_queue(void); 327 328int buf_flushdirtyblks_skipinfo (vnode_t, int, int, const char *); 329void buf_wait_for_shadow_io (vnode_t, daddr64_t); 330 331#ifdef BUF_MAKE_PRIVATE 332errno_t buf_make_private(buf_t bp); 333#endif 334 335#ifdef CONFIG_PROTECT 336void buf_setcpaddr(buf_t, struct cprotect *); 337void buf_setcpoff (buf_t, uint64_t); 338#endif 339 340__END_DECLS 341 342 343/* 344 * Stats on usefulness of the buffer cache 345 */ 346struct bufstats { 347 long bufs_incore; /* found incore */ 348 long bufs_busyincore; /* found incore. was busy */ 349 long bufs_vmhits; /* not incore. found in VM */ 350 long bufs_miss; /* not incore. not in VM */ 351 long bufs_sleeps; /* buffer starvation */ 352 long bufs_eblk; /* Calls to geteblk */ 353 long bufs_iobufmax; /* Max. number of IO buffers used */ 354 long bufs_iobufinuse; /* number of IO buffers in use */ 355 long bufs_iobufsleeps; /* IO buffer starvation */ 356}; 357 358#endif /* KERNEL */ 359#endif /* !_SYS_BUF_H_ */ 360