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