bsd/sys/buf.h

   1 /*
   2  * Copyright (c) 2006 Apple Computer, Inc. All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_OSREFERENCE_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
  10  * License may not be used to create, or enable the creation or
  11  * redistribution of, unlawful or unlicensed copies of an Apple operating
  12  * system, or to circumvent, violate, or enable the circumvention or
  13  * violation of, any terms of an Apple operating system software license
  14  * agreement.
  15  *
  16  * Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
  18  * file.
  19  *
  20  * The Original Code and all software distributed under the License are
  21  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  22  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  23  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  25  * Please see the License for the specific language governing rights and
  26  * limitations under the License.
  27  *
  28  * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  29  */
  30 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
  31 /*
  32  * Copyright (c) 1982, 1986, 1989, 1993
  33  *      The Regents of the University of California.  All rights reserved.
  34  * (c) UNIX System Laboratories, Inc.
  35  * All or some portions of this file are derived from material licensed
  36  * to the University of California by American Telephone and Telegraph
  37  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
  38  * the permission of UNIX System Laboratories, Inc.
  39  *
  40  * Redistribution and use in source and binary forms, with or without
  41  * modification, are permitted provided that the following conditions
  42  * are met:
  43  * 1. Redistributions of source code must retain the above copyright
  44  *    notice, this list of conditions and the following disclaimer.
  45  * 2. Redistributions in binary form must reproduce the above copyright
  46  *    notice, this list of conditions and the following disclaimer in the
  47  *    documentation and/or other materials provided with the distribution.
  48  * 3. All advertising materials mentioning features or use of this software
  49  *    must display the following acknowledgement:
  50  *      This product includes software developed by the University of
  51  *      California, Berkeley and its contributors.
  52  * 4. Neither the name of the University nor the names of its contributors
  53  *    may be used to endorse or promote products derived from this software
  54  *    without specific prior written permission.
  55  *
  56  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  57  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  58  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  59  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  60  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  61  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  62  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  63  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  64  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  65  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  66  * SUCH DAMAGE.
  67  *
  68  *      @(#)buf.h       8.9 (Berkeley) 3/30/95
  69  */
  70
  71 #ifndef _SYS_BUF_H_
  72 #define _SYS_BUF_H_
  73
  74 #include <sys/cdefs.h>
  75 #include <sys/kernel_types.h>
  76 #include <mach/memory_object_types.h>
  77
  78
  79 #define B_WRITE         0x00000000      /* Write buffer (pseudo flag). */
  80 #define B_READ          0x00000001      /* Read buffer. */
  81 #define B_ASYNC         0x00000002      /* Start I/O, do not wait. */
  82 #define B_NOCACHE       0x00000004      /* Do not cache block after use. */
  83 #define B_DELWRI        0x00000008      /* Delay I/O until buffer reused. */
  84 #define B_LOCKED        0x00000010      /* Locked in core (not reusable). */
  85 #define B_PHYS          0x00000020      /* I/O to user memory. */
  86 #define B_CLUSTER       0x00000040      /* UPL based I/O generated by cluster layer */
  87 #define B_PAGEIO        0x00000080      /* Page in/out */
  88 #define B_META          0x00000100      /* buffer contains meta-data. */
  89 /*
  90  * make sure to check when adding flags that
  91  * that the new flags don't overlap the definitions
  92  * in buf_internal.h
  93  */
  94
  95 __BEGIN_DECLS
  96
  97 /*
  98  * mark the buffer associated with buf_t
  99  * as AGED with respect to the LRU cache
 100  */
 101 void    buf_markaged(buf_t);
 102
 103 /*
 104  * mark the buffer associated with buf_t
 105  * as invalid... on release, it will go
 106  * directly to the free list
 107  */
 108 void    buf_markinvalid(buf_t);
 109
 110 /*
 111  * mark the buffer assoicated with buf_t
 112  * as a delayed write...
 113  */
 114 void    buf_markdelayed(buf_t);
 115
 116 /*
 117  * mark the buffer associated with buf_t
 118  * as having been interrupted... EINTR
 119  */
 120 void    buf_markeintr(buf_t);
 121
 122 /*
 123  * returns 1 if the buffer associated with buf_t
 124  * contains valid data... 0 if it does not
 125  */
 126 int     buf_valid(buf_t);
 127
 128 /*
 129  * returns 1 if the buffer was already valid
 130  * in the cache... i.e. no I/O was performed
 131  * returns 0 otherwise
 132  */
 133 int     buf_fromcache(buf_t);
 134
 135 /*
 136  * returns the UPL associated with buf_t
 137  */
 138 void *  buf_upl(buf_t);
 139
 140 /*
 141  * returns the offset into the UPL
 142  * associated with buf_t which is to be
 143  * used as the base offset for this I/O
 144  */
 145 uint32_t buf_uploffset(buf_t);
 146
 147 /*
 148  * returns read credential associated with buf_t
 149  * a reference is taken which must be explicilty dropped
 150  */
 151 ucred_t buf_rcred(buf_t);
 152
 153 /*
 154  * returns write credential associated with buf_t
 155  * a reference is taken which must be explicilty dropped
 156  */
 157 ucred_t buf_wcred(buf_t);
 158
 159 /*
 160  * returns process handle associated with buf_t
 161  * i.e identity of task that issued the I/O
 162  */
 163 proc_t  buf_proc(buf_t);
 164
 165 uint32_t buf_dirtyoff(buf_t);
 166 uint32_t buf_dirtyend(buf_t);
 167 void    buf_setdirtyoff(buf_t, uint32_t);
 168 void    buf_setdirtyend(buf_t, uint32_t);
 169
 170 /*
 171  * return the errno value associated with buf_t
 172  */
 173 errno_t buf_error(buf_t);
 174
 175 /*
 176  * set errno on buf_t
 177  */
 178 void    buf_seterror(buf_t, errno_t);
 179
 180 /*
 181  * set specified flags on buf_t
 182  * B_LOCKED/B_NOCACHE/B_ASYNC/B_READ/B_WRITE/B_PAGEIO
 183  */
 184 void    buf_setflags(buf_t, int32_t);
 185
 186 /*
 187  * clear specified flags on buf_t
 188  * B_LOCKED/B_NOCACHE/B_ASYNC/B_READ/B_WRITE/B_PAGEIO
 189  */
 190 void    buf_clearflags(buf_t, int32_t);
 191
 192 /*
 193  * return external flags associated with buf_t
 194  * B_CLUSTER/B_PHYS/B_LOCKED/B_DELWRI/B_ASYNC/B_READ/B_WRITE/B_META/B_PAGEIO
 195  */
 196 int32_t buf_flags(buf_t);
 197
 198 /*
 199  * clears I/O related flags (both internal and
 200  * external) associated with buf_t and allows
 201  * the following to be set...
 202  * B_READ/B_WRITE/B_ASYNC/B_NOCACHE
 203  */
 204 void    buf_reset(buf_t, int32_t);
 205
 206 /*
 207  * insure that the data storage associated with buf_t
 208  * is addressable
 209  */
 210 errno_t buf_map(buf_t, caddr_t *);
 211
 212 /*
 213  * release our need to have the storage associated
 214  * with buf_t in an addressable state
 215  */
 216 errno_t buf_unmap(buf_t);
 217
 218 /*
 219  * set driver specific data for buf_t
 220  */
 221 void    buf_setdrvdata(buf_t, void *);
 222
 223 /*
 224  * retrieve driver specific data associated with buf_t
 225  */
 226 void *  buf_drvdata(buf_t);
 227
 228 /*
 229  * set fs specific data for buf_t
 230  */
 231 void    buf_setfsprivate(buf_t, void *);
 232
 233 /*
 234  * retrieve driver specific data associated with buf_t
 235  */
 236 void *  buf_fsprivate(buf_t);
 237
 238 /*
 239  * retrieve the phsyical block number associated with buf_t
 240  */
 241 daddr64_t buf_blkno(buf_t);
 242
 243 /*
 244  * retrieve the logical block number associated with buf_t
 245  * i.e. the block number derived from the file offset
 246  */
 247 daddr64_t buf_lblkno(buf_t);
 248
 249 /*
 250  * set the phsyical block number associated with buf_t
 251  */
 252 void    buf_setblkno(buf_t, daddr64_t);
 253
 254 /*
 255  * set the logical block number associated with buf_t
 256  * i.e. the block number derived from the file offset
 257  */
 258 void    buf_setlblkno(buf_t, daddr64_t);
 259
 260 /*
 261  * retrieve the count of valid bytes associated with buf_t
 262  */
 263 uint32_t buf_count(buf_t);
 264
 265 /*
 266  * retrieve the size of the data store assoicated with buf_t
 267  */
 268 uint32_t buf_size(buf_t);
 269
 270 /*
 271  * retrieve the residual I/O count assoicated with buf_t
 272  * i.e. number of bytes that have not yet been completed
 273  */
 274 uint32_t buf_resid(buf_t);
 275
 276 /*
 277  * set the count of bytes associated with buf_t
 278  * typically used to set the size of the I/O to be performed
 279  */
 280 void    buf_setcount(buf_t, uint32_t);
 281
 282 /*
 283  * set the size of the buffer store associated with buf_t
 284  * typically used when providing private storage to buf_t
 285  */
 286 void    buf_setsize(buf_t, uint32_t);
 287
 288 /*
 289  * set the size in bytes of the unfinished I/O associated with buf_t
 290  */
 291 void    buf_setresid(buf_t, uint32_t);
 292
 293 /*
 294  * associate kernel addressable storage with buf_t
 295  */
 296 void    buf_setdataptr(buf_t, uintptr_t);
 297
 298 /*
 299  * retrieve pointer to buffer associated with buf_t
 300  * if non-null, than guaranteed to be kernel addressable
 301  * size of buffer can be retrieved via buf_size
 302  * size of valid data can be retrieved via buf_count
 303  * if NULL, than use buf_map/buf_unmap to manage access to the underlying storage
 304  */
 305 uintptr_t buf_dataptr(buf_t);
 306
 307 /*
 308  * return the vnode_t associated with buf_t
 309  */
 310 vnode_t buf_vnode(buf_t);
 311
 312 /*
 313  * assign vnode_t to buf_t... the
 314  * device currently associated with
 315  * but_t is not changed.
 316  */
 317 void    buf_setvnode(buf_t, vnode_t);
 318
 319 /*
 320  * return the dev_t associated with buf_t
 321  */
 322 dev_t   buf_device(buf_t);
 323
 324 /*
 325  * assign the dev_t associated with vnode_t
 326  * to buf_t
 327  */
 328 errno_t buf_setdevice(buf_t, vnode_t);
 329
 330 errno_t buf_strategy(vnode_t, void *);
 331
 332 /*
 333  * flags for buf_invalblkno
 334  */
 335 #define BUF_WAIT        0x01
 336
 337 errno_t buf_invalblkno(vnode_t, daddr64_t, int);
 338
 339
 340 /*
 341  * return the callback function pointer
 342  * if the callback is still valid
 343  * returns NULL if a buffer that was not
 344  * allocated via buf_alloc is specified
 345  * or if a callback has not been set or
 346  * it has already fired...
 347  */
 348 void * buf_callback(buf_t);
 349
 350 /*
 351  * assign a one-shot callback function (driven from biodone)
 352  * to a buf_t allocated via buf_alloc... a caller specified
 353  * arg is passed to the callback function
 354  */
 355 errno_t buf_setcallback(buf_t, void (*)(buf_t, void *), void *);
 356
 357 /*
 358  * add a upl_t to a buffer allocated via buf_alloc
 359  * and set the offset into the upl_t (must be page
 360  * aligned).
 361  */
 362 errno_t buf_setupl(buf_t, upl_t, uint32_t);
 363
 364 /*
 365  * allocate a buf_t that is a clone of the buf_t
 366  * passed in, but whose I/O range is a subset...
 367  * if a callback routine is specified, it will
 368  * be called from buf_biodone with the bp and
 369  * arg specified.
 370  * it must be freed via buf_free
 371  */
 372 buf_t   buf_clone(buf_t, int, int, void (*)(buf_t, void *), void *);
 373
 374 /*
 375  * allocate a buf_t associated with vnode_t
 376  * that has NO storage associated with it
 377  * but is suitable for use in issuing I/Os
 378  * after storage has been assigned via buf_setdataptr
 379  * or buf_addupl
 380  */
 381 buf_t   buf_alloc(vnode_t);
 382
 383 /*
 384  * free a buf_t that was allocated via buf_alloc
 385  * any private storage associated with buf_t is the
 386  * responsiblity of the caller to release
 387  */
 388 void    buf_free(buf_t);
 389
 390 /*
 391  * flags for buf_invalidateblks
 392  */
 393 #define BUF_WRITE_DATA  0x0001          /* write data blocks first */
 394 #define BUF_SKIP_META   0x0002          /* skip over metadata blocks */
 395
 396 int     buf_invalidateblks(vnode_t, int, int, int);
 397 /*
 398  * flags for buf_flushdirtyblks and buf_iterate
 399  */
 400 #define BUF_SKIP_NONLOCKED      0x01
 401 #define BUF_SKIP_LOCKED         0x02
 402
 403 void    buf_flushdirtyblks(vnode_t, int, int, char *);
 404 void    buf_iterate(vnode_t, int (*)(buf_t, void *), int, void *);
 405
 406 #define BUF_RETURNED            0
 407 #define BUF_RETURNED_DONE       1
 408 #define BUF_CLAIMED             2
 409 #define BUF_CLAIMED_DONE        3
 410
 411 /*
 412  * zero the storage associated with buf_t
 413  */
 414 void    buf_clear(buf_t);
 415
 416 errno_t buf_bawrite(buf_t);
 417 errno_t buf_bdwrite(buf_t);
 418 errno_t buf_bwrite(buf_t);
 419
 420 void    buf_biodone(buf_t);
 421 errno_t buf_biowait(buf_t);
 422 void    buf_brelse(buf_t);
 423
 424 errno_t buf_bread(vnode_t, daddr64_t, int, ucred_t, buf_t *);
 425 errno_t buf_breadn(vnode_t, daddr64_t, int, daddr64_t *, int *, int, ucred_t, buf_t *);
 426 errno_t buf_meta_bread(vnode_t, daddr64_t, int, ucred_t, buf_t *);
 427 errno_t buf_meta_breadn(vnode_t, daddr64_t, int, daddr64_t *, int *, int, ucred_t, buf_t *);
 428
 429 u_int   minphys(buf_t bp);
 430 int     physio(void (*)(buf_t), buf_t, dev_t, int ,  u_int (*)(buf_t), struct uio *, int );
 431
 432
 433 /*
 434  * Flags for operation type in getblk()
 435  */
 436 #define BLK_READ        0x01    /* buffer for read */
 437 #define BLK_WRITE       0x02    /* buffer for write */
 438 #define BLK_META        0x10    /* buffer for metadata */
 439 /*
 440  * modifier for above flags...  if set, getblk will only return
 441  * a bp that is already valid... i.e. found in the cache
 442  */
 443 #define BLK_ONLYVALID   0x80000000
 444
 445 /* timeout is in msecs */
 446 buf_t   buf_getblk(vnode_t, daddr64_t, int, int, int, int);
 447 buf_t   buf_geteblk(int);
 448
 449 __END_DECLS
 450
 451
 452 /* Macros to clear/set/test flags. */
 453 #define SET(t, f)       (t) |= (f)
 454 #define CLR(t, f)       (t) &= ~(f)
 455 #define ISSET(t, f)     ((t) & (f))
 456
 457
 458 #endif /* !_SYS_BUF_H_ */