bsd/sys/buf.h

   1 /*
   2  * Copyright (c) 2000-2005 Apple Computer, 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_H_
  70 #define _SYS_BUF_H_
  71
  72 #include <sys/cdefs.h>
  73 #include <sys/kernel_types.h>
  74 #include <mach/memory_object_types.h>
  75
  76
  77 #define B_WRITE         0x00000000      /* Write buffer (pseudo flag). */
  78 #define B_READ          0x00000001      /* Read buffer. */
  79 #define B_ASYNC         0x00000002      /* Start I/O, do not wait. */
  80 #define B_NOCACHE       0x00000004      /* Do not cache block after use. */
  81 #define B_DELWRI        0x00000008      /* Delay I/O until buffer reused. */
  82 #define B_LOCKED        0x00000010      /* Locked in core (not reusable). */
  83 #define B_PHYS          0x00000020      /* I/O to user memory. */
  84 #define B_CLUSTER       0x00000040      /* UPL based I/O generated by cluster layer */
  85 #define B_PAGEIO        0x00000080      /* Page in/out */
  86 #define B_META          0x00000100      /* buffer contains meta-data. */
  87 #define B_RAW           0x00000200      /* Set by physio for raw transfers. */
  88 #define B_FUA           0x00000400      /* Write-through disk cache(if supported) */
  89 #define B_PASSIVE       0x00000800      /* PASSIVE I/Os are ignored by THROTTLE I/O */
  90 /*
  91  * make sure to check when adding flags that
  92  * that the new flags don't overlap the definitions
  93  * in buf_internal.h
  94  */
  95
  96 __BEGIN_DECLS
  97
  98 /*
  99  * mark the buffer associated with buf_t
 100  * as AGED with respect to the LRU cache
 101  */
 102 void    buf_markaged(buf_t);
 103
 104 /*
 105  * mark the buffer associated with buf_t
 106  * as invalid... on release, it will go
 107  * directly to the free list
 108  */
 109 void    buf_markinvalid(buf_t);
 110
 111 /*
 112  * mark the buffer assoicated with buf_t
 113  * as a delayed write...
 114  */
 115 void    buf_markdelayed(buf_t);
 116
 117 /*
 118  * mark the buffer associated with buf_t
 119  * as having been interrupted... EINTR
 120  */
 121 void    buf_markeintr(buf_t);
 122
 123 /*
 124  * mark the buffer associated with buf_t
 125  * for write through disk cache if device supports
 126  */
 127 void    buf_markfua(buf_t);
 128
 129 /*
 130  * returns 1 if the buffer associated with buf_t
 131  * is set for write through disk cache... 0 if it does not
 132  */
 133 int     buf_fua(buf_t);
 134
 135 /*
 136  * returns 1 if the buffer associated with buf_t
 137  * contains valid data... 0 if it does not
 138  */
 139 int     buf_valid(buf_t);
 140
 141 /*
 142  * returns 1 if the buffer was already valid
 143  * in the cache... i.e. no I/O was performed
 144  * returns 0 otherwise
 145  */
 146 int     buf_fromcache(buf_t);
 147
 148 /*
 149  * returns the UPL associated with buf_t
 150  */
 151 void *  buf_upl(buf_t);
 152
 153 /*
 154  * returns the offset into the UPL
 155  * associated with buf_t which is to be
 156  * used as the base offset for this I/O
 157  */
 158 uint32_t buf_uploffset(buf_t);
 159
 160 /*
 161  * returns read credential associated with buf_t
 162  * a reference is taken which must be explicilty dropped
 163  */
 164 ucred_t buf_rcred(buf_t);
 165
 166 /*
 167  * returns write credential associated with buf_t
 168  * a reference is taken which must be explicilty dropped
 169  */
 170 ucred_t buf_wcred(buf_t);
 171
 172 /*
 173  * returns process handle associated with buf_t
 174  * i.e identity of task that issued the I/O
 175  */
 176 proc_t  buf_proc(buf_t);
 177
 178 uint32_t buf_dirtyoff(buf_t);
 179 uint32_t buf_dirtyend(buf_t);
 180 void    buf_setdirtyoff(buf_t, uint32_t);
 181 void    buf_setdirtyend(buf_t, uint32_t);
 182
 183 /*
 184  * return the errno value associated with buf_t
 185  */
 186 errno_t buf_error(buf_t);
 187
 188 /*
 189  * set errno on buf_t
 190  */
 191 void    buf_seterror(buf_t, errno_t);
 192
 193 /*
 194  * set specified flags on buf_t
 195  * B_LOCKED/B_NOCACHE/B_ASYNC/B_READ/B_WRITE/B_PAGEIO/B_FUA
 196  */
 197 void    buf_setflags(buf_t, int32_t);
 198
 199 /*
 200  * clear specified flags on buf_t
 201  * B_LOCKED/B_NOCACHE/B_ASYNC/B_READ/B_WRITE/B_PAGEIO/B_FUA
 202  */
 203 void    buf_clearflags(buf_t, int32_t);
 204
 205 /*
 206  * return external flags associated with buf_t
 207  * B_CLUSTER/B_PHYS/B_LOCKED/B_DELWRI/B_ASYNC/B_READ/B_WRITE/B_META/B_PAGEIO/B_FUA
 208  */
 209 int32_t buf_flags(buf_t);
 210
 211 /*
 212  * clears I/O related flags (both internal and
 213  * external) associated with buf_t and allows
 214  * the following to be set...
 215  * B_READ/B_WRITE/B_ASYNC/B_NOCACHE
 216  */
 217 void    buf_reset(buf_t, int32_t);
 218
 219 /*
 220  * insure that the data storage associated with buf_t
 221  * is addressable
 222  */
 223 errno_t buf_map(buf_t, caddr_t *);
 224
 225 /*
 226  * release our need to have the storage associated
 227  * with buf_t in an addressable state
 228  */
 229 errno_t buf_unmap(buf_t);
 230
 231 /*
 232  * set driver specific data for buf_t
 233  */
 234 void    buf_setdrvdata(buf_t, void *);
 235
 236 /*
 237  * retrieve driver specific data associated with buf_t
 238  */
 239 void *  buf_drvdata(buf_t);
 240
 241 /*
 242  * set fs specific data for buf_t
 243  */
 244 void    buf_setfsprivate(buf_t, void *);
 245
 246 /*
 247  * retrieve driver specific data associated with buf_t
 248  */
 249 void *  buf_fsprivate(buf_t);
 250
 251 /*
 252  * retrieve the phsyical block number associated with buf_t
 253  */
 254 daddr64_t buf_blkno(buf_t);
 255
 256 /*
 257  * retrieve the logical block number associated with buf_t
 258  * i.e. the block number derived from the file offset
 259  */
 260 daddr64_t buf_lblkno(buf_t);
 261
 262 /*
 263  * set the phsyical block number associated with buf_t
 264  */
 265 void    buf_setblkno(buf_t, daddr64_t);
 266
 267 /*
 268  * set the logical block number associated with buf_t
 269  * i.e. the block number derived from the file offset
 270  */
 271 void    buf_setlblkno(buf_t, daddr64_t);
 272
 273 /*
 274  * retrieve the count of valid bytes associated with buf_t
 275  */
 276 uint32_t buf_count(buf_t);
 277
 278 /*
 279  * retrieve the size of the data store assoicated with buf_t
 280  */
 281 uint32_t buf_size(buf_t);
 282
 283 /*
 284  * retrieve the residual I/O count assoicated with buf_t
 285  * i.e. number of bytes that have not yet been completed
 286  */
 287 uint32_t buf_resid(buf_t);
 288
 289 /*
 290  * set the count of bytes associated with buf_t
 291  * typically used to set the size of the I/O to be performed
 292  */
 293 void    buf_setcount(buf_t, uint32_t);
 294
 295 /*
 296  * set the size of the buffer store associated with buf_t
 297  * typically used when providing private storage to buf_t
 298  */
 299 void    buf_setsize(buf_t, uint32_t);
 300
 301 /*
 302  * set the size in bytes of the unfinished I/O associated with buf_t
 303  */
 304 void    buf_setresid(buf_t, uint32_t);
 305
 306 /*
 307  * associate kernel addressable storage with buf_t
 308  */
 309 void    buf_setdataptr(buf_t, uintptr_t);
 310
 311 /*
 312  * retrieve pointer to buffer associated with buf_t
 313  * if non-null, than guaranteed to be kernel addressable
 314  * size of buffer can be retrieved via buf_size
 315  * size of valid data can be retrieved via buf_count
 316  * if NULL, than use buf_map/buf_unmap to manage access to the underlying storage
 317  */
 318 uintptr_t buf_dataptr(buf_t);
 319
 320 /*
 321  * return the vnode_t associated with buf_t
 322  */
 323 vnode_t buf_vnode(buf_t);
 324
 325 /*
 326  * assign vnode_t to buf_t... the
 327  * device currently associated with
 328  * but_t is not changed.
 329  */
 330 void    buf_setvnode(buf_t, vnode_t);
 331
 332 /*
 333  * return the dev_t associated with buf_t
 334  */
 335 dev_t   buf_device(buf_t);
 336
 337 /*
 338  * assign the dev_t associated with vnode_t
 339  * to buf_t
 340  */
 341 errno_t buf_setdevice(buf_t, vnode_t);
 342
 343 errno_t buf_strategy(vnode_t, void *);
 344
 345 /*
 346  * flags for buf_invalblkno
 347  */
 348 #define BUF_WAIT        0x01
 349
 350 errno_t buf_invalblkno(vnode_t, daddr64_t, int);
 351
 352
 353 /*
 354  * return the callback function pointer
 355  * if the callback is still valid
 356  * returns NULL if a buffer that was not
 357  * allocated via buf_alloc is specified
 358  * or if a callback has not been set or
 359  * it has already fired...
 360  */
 361 void * buf_callback(buf_t);
 362
 363 /*
 364  * assign a one-shot callback function (driven from biodone)
 365  * to a buf_t allocated via buf_alloc... a caller specified
 366  * arg is passed to the callback function
 367  */
 368 errno_t buf_setcallback(buf_t, void (*)(buf_t, void *), void *);
 369
 370 /*
 371  * add a upl_t to a buffer allocated via buf_alloc
 372  * and set the offset into the upl_t (must be page
 373  * aligned).
 374  */
 375 errno_t buf_setupl(buf_t, upl_t, uint32_t);
 376
 377 /*
 378  * allocate a buf_t that is a clone of the buf_t
 379  * passed in, but whose I/O range is a subset...
 380  * if a callback routine is specified, it will
 381  * be called from buf_biodone with the bp and
 382  * arg specified.
 383  * it must be freed via buf_free
 384  */
 385 buf_t   buf_clone(buf_t, int, int, void (*)(buf_t, void *), void *);
 386
 387 /*
 388  * allocate a buf_t associated with vnode_t
 389  * that has NO storage associated with it
 390  * but is suitable for use in issuing I/Os
 391  * after storage has been assigned via buf_setdataptr
 392  * or buf_addupl
 393  */
 394 buf_t   buf_alloc(vnode_t);
 395
 396 /*
 397  * free a buf_t that was allocated via buf_alloc
 398  * any private storage associated with buf_t is the
 399  * responsiblity of the caller to release
 400  */
 401 void    buf_free(buf_t);
 402
 403 /*
 404  * flags for buf_invalidateblks
 405  */
 406 #define BUF_WRITE_DATA  0x0001          /* write data blocks first */
 407 #define BUF_SKIP_META   0x0002          /* skip over metadata blocks */
 408
 409 int     buf_invalidateblks(vnode_t, int, int, int);
 410 /*
 411  * flags for buf_flushdirtyblks and buf_iterate
 412  */
 413 #define BUF_SKIP_NONLOCKED      0x01
 414 #define BUF_SKIP_LOCKED         0x02
 415 #define BUF_SCAN_CLEAN          0x04    /* scan only the clean buffers */
 416 #define BUF_SCAN_DIRTY          0x08    /* scan only the dirty buffers */
 417 #define BUF_NOTIFY_BUSY         0x10    /* notify the caller about the busy pages during the scan */
 418
 419 void    buf_flushdirtyblks(vnode_t, int, int, const char *);
 420 void    buf_iterate(vnode_t, int (*)(buf_t, void *), int, void *);
 421
 422 #define BUF_RETURNED            0
 423 #define BUF_RETURNED_DONE       1
 424 #define BUF_CLAIMED             2
 425 #define BUF_CLAIMED_DONE        3
 426
 427 /*
 428  * zero the storage associated with buf_t
 429  */
 430 void    buf_clear(buf_t);
 431
 432 errno_t buf_bawrite(buf_t);
 433 errno_t buf_bdwrite(buf_t);
 434 errno_t buf_bwrite(buf_t);
 435
 436 void    buf_biodone(buf_t);
 437 errno_t buf_biowait(buf_t);
 438 void    buf_brelse(buf_t);
 439
 440 errno_t buf_bread(vnode_t, daddr64_t, int, ucred_t, buf_t *);
 441 errno_t buf_breadn(vnode_t, daddr64_t, int, daddr64_t *, int *, int, ucred_t, buf_t *);
 442 errno_t buf_meta_bread(vnode_t, daddr64_t, int, ucred_t, buf_t *);
 443 errno_t buf_meta_breadn(vnode_t, daddr64_t, int, daddr64_t *, int *, int, ucred_t, buf_t *);
 444
 445 u_int   minphys(buf_t bp);
 446 int     physio(void (*)(buf_t), buf_t, dev_t, int ,  u_int (*)(buf_t), struct uio *, int );
 447
 448
 449 /*
 450  * Flags for operation type in getblk()
 451  */
 452 #define BLK_READ        0x01    /* buffer for read */
 453 #define BLK_WRITE       0x02    /* buffer for write */
 454 #define BLK_META        0x10    /* buffer for metadata */
 455 /*
 456  * modifier for above flags...  if set, getblk will only return
 457  * a bp that is already valid... i.e. found in the cache
 458  */
 459 #define BLK_ONLYVALID   0x80000000
 460
 461 /* timeout is in msecs */
 462 buf_t   buf_getblk(vnode_t, daddr64_t, int, int, int, int);
 463 buf_t   buf_geteblk(int);
 464
 465 __END_DECLS
 466
 467
 468 /* Macros to clear/set/test flags. */
 469 #define SET(t, f)       (t) |= (f)
 470 #define CLR(t, f)       (t) &= ~(f)
 471 #define ISSET(t, f)     ((t) & (f))
 472
 473
 474 #endif /* !_SYS_BUF_H_ */