bsd/sys/buf.h

   1 /*
   2  * Copyright (c) 2000-2005 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
  23 /*
  24  * Copyright (c) 1982, 1986, 1989, 1993
  25  *      The Regents of the University of California.  All rights reserved.
  26  * (c) UNIX System Laboratories, Inc.
  27  * All or some portions of this file are derived from material licensed
  28  * to the University of California by American Telephone and Telegraph
  29  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
  30  * the permission of UNIX System Laboratories, Inc.
  31  *
  32  * Redistribution and use in source and binary forms, with or without
  33  * modification, are permitted provided that the following conditions
  34  * are met:
  35  * 1. Redistributions of source code must retain the above copyright
  36  *    notice, this list of conditions and the following disclaimer.
  37  * 2. Redistributions in binary form must reproduce the above copyright
  38  *    notice, this list of conditions and the following disclaimer in the
  39  *    documentation and/or other materials provided with the distribution.
  40  * 3. All advertising materials mentioning features or use of this software
  41  *    must display the following acknowledgement:
  42  *      This product includes software developed by the University of
  43  *      California, Berkeley and its contributors.
  44  * 4. Neither the name of the University nor the names of its contributors
  45  *    may be used to endorse or promote products derived from this software
  46  *    without specific prior written permission.
  47  *
  48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  58  * SUCH DAMAGE.
  59  *
  60  *      @(#)buf.h       8.9 (Berkeley) 3/30/95
  61  */
  62
  63 #ifndef _SYS_BUF_H_
  64 #define _SYS_BUF_H_
  65
  66 #include <sys/cdefs.h>
  67 #include <sys/kernel_types.h>
  68 #include <mach/memory_object_types.h>
  69
  70
  71 #define B_WRITE         0x00000000      /* Write buffer (pseudo flag). */
  72 #define B_READ          0x00000001      /* Read buffer. */
  73 #define B_ASYNC         0x00000002      /* Start I/O, do not wait. */
  74 #define B_NOCACHE       0x00000004      /* Do not cache block after use. */
  75 #define B_DELWRI        0x00000008      /* Delay I/O until buffer reused. */
  76 #define B_LOCKED        0x00000010      /* Locked in core (not reusable). */
  77 #define B_PHYS          0x00000020      /* I/O to user memory. */
  78 #define B_CLUSTER       0x00000040      /* UPL based I/O generated by cluster layer */
  79 #define B_PAGEIO        0x00000080      /* Page in/out */
  80 #define B_META          0x00000100      /* buffer contains meta-data. */
  81 /*
  82  * make sure to check when adding flags that
  83  * that the new flags don't overlap the definitions
  84  * in buf_internal.h
  85  */
  86
  87 __BEGIN_DECLS
  88
  89 /*
  90  * mark the buffer associated with buf_t
  91  * as AGED with respect to the LRU cache
  92  */
  93 void    buf_markaged(buf_t);
  94
  95 /*
  96  * mark the buffer associated with buf_t
  97  * as invalid... on release, it will go
  98  * directly to the free list
  99  */
 100 void    buf_markinvalid(buf_t);
 101
 102 /*
 103  * mark the buffer assoicated with buf_t
 104  * as a delayed write...
 105  */
 106 void    buf_markdelayed(buf_t);
 107
 108 /*
 109  * mark the buffer associated with buf_t
 110  * as having been interrupted... EINTR
 111  */
 112 void    buf_markeintr(buf_t);
 113
 114 /*
 115  * returns 1 if the buffer associated with buf_t
 116  * contains valid data... 0 if it does not
 117  */
 118 int     buf_valid(buf_t);
 119
 120 /*
 121  * returns 1 if the buffer was already valid
 122  * in the cache... i.e. no I/O was performed
 123  * returns 0 otherwise
 124  */
 125 int     buf_fromcache(buf_t);
 126
 127 /*
 128  * returns the UPL associated with buf_t
 129  */
 130 void *  buf_upl(buf_t);
 131
 132 /*
 133  * returns the offset into the UPL
 134  * associated with buf_t which is to be
 135  * used as the base offset for this I/O
 136  */
 137 uint32_t buf_uploffset(buf_t);
 138
 139 /*
 140  * returns read credential associated with buf_t
 141  * a reference is taken which must be explicilty dropped
 142  */
 143 ucred_t buf_rcred(buf_t);
 144
 145 /*
 146  * returns write credential associated with buf_t
 147  * a reference is taken which must be explicilty dropped
 148  */
 149 ucred_t buf_wcred(buf_t);
 150
 151 /*
 152  * returns process handle associated with buf_t
 153  * i.e identity of task that issued the I/O
 154  */
 155 proc_t  buf_proc(buf_t);
 156
 157 uint32_t buf_dirtyoff(buf_t);
 158 uint32_t buf_dirtyend(buf_t);
 159 void    buf_setdirtyoff(buf_t, uint32_t);
 160 void    buf_setdirtyend(buf_t, uint32_t);
 161
 162 /*
 163  * return the errno value associated with buf_t
 164  */
 165 errno_t buf_error(buf_t);
 166
 167 /*
 168  * set errno on buf_t
 169  */
 170 void    buf_seterror(buf_t, errno_t);
 171
 172 /*
 173  * set specified flags on buf_t
 174  * B_LOCKED/B_NOCACHE/B_ASYNC/B_READ/B_WRITE/B_PAGEIO
 175  */
 176 void    buf_setflags(buf_t, int32_t);
 177
 178 /*
 179  * clear specified flags on buf_t
 180  * B_LOCKED/B_NOCACHE/B_ASYNC/B_READ/B_WRITE/B_PAGEIO
 181  */
 182 void    buf_clearflags(buf_t, int32_t);
 183
 184 /*
 185  * return external flags associated with buf_t
 186  * B_CLUSTER/B_PHYS/B_LOCKED/B_DELWRI/B_ASYNC/B_READ/B_WRITE/B_META/B_PAGEIO
 187  */
 188 int32_t buf_flags(buf_t);
 189
 190 /*
 191  * clears I/O related flags (both internal and
 192  * external) associated with buf_t and allows
 193  * the following to be set...
 194  * B_READ/B_WRITE/B_ASYNC/B_NOCACHE
 195  */
 196 void    buf_reset(buf_t, int32_t);
 197
 198 /*
 199  * insure that the data storage associated with buf_t
 200  * is addressable
 201  */
 202 errno_t buf_map(buf_t, caddr_t *);
 203
 204 /*
 205  * release our need to have the storage associated
 206  * with buf_t in an addressable state
 207  */
 208 errno_t buf_unmap(buf_t);
 209
 210 /*
 211  * set driver specific data for buf_t
 212  */
 213 void    buf_setdrvdata(buf_t, void *);
 214
 215 /*
 216  * retrieve driver specific data associated with buf_t
 217  */
 218 void *  buf_drvdata(buf_t);
 219
 220 /*
 221  * set fs specific data for buf_t
 222  */
 223 void    buf_setfsprivate(buf_t, void *);
 224
 225 /*
 226  * retrieve driver specific data associated with buf_t
 227  */
 228 void *  buf_fsprivate(buf_t);
 229
 230 /*
 231  * retrieve the phsyical block number associated with buf_t
 232  */
 233 daddr64_t buf_blkno(buf_t);
 234
 235 /*
 236  * retrieve the logical block number associated with buf_t
 237  * i.e. the block number derived from the file offset
 238  */
 239 daddr64_t buf_lblkno(buf_t);
 240
 241 /*
 242  * set the phsyical block number associated with buf_t
 243  */
 244 void    buf_setblkno(buf_t, daddr64_t);
 245
 246 /*
 247  * set the logical block number associated with buf_t
 248  * i.e. the block number derived from the file offset
 249  */
 250 void    buf_setlblkno(buf_t, daddr64_t);
 251
 252 /*
 253  * retrieve the count of valid bytes associated with buf_t
 254  */
 255 uint32_t buf_count(buf_t);
 256
 257 /*
 258  * retrieve the size of the data store assoicated with buf_t
 259  */
 260 uint32_t buf_size(buf_t);
 261
 262 /*
 263  * retrieve the residual I/O count assoicated with buf_t
 264  * i.e. number of bytes that have not yet been completed
 265  */
 266 uint32_t buf_resid(buf_t);
 267
 268 /*
 269  * set the count of bytes associated with buf_t
 270  * typically used to set the size of the I/O to be performed
 271  */
 272 void    buf_setcount(buf_t, uint32_t);
 273
 274 /*
 275  * set the size of the buffer store associated with buf_t
 276  * typically used when providing private storage to buf_t
 277  */
 278 void    buf_setsize(buf_t, uint32_t);
 279
 280 /*
 281  * set the size in bytes of the unfinished I/O associated with buf_t
 282  */
 283 void    buf_setresid(buf_t, uint32_t);
 284
 285 /*
 286  * associate kernel addressable storage with buf_t
 287  */
 288 void    buf_setdataptr(buf_t, uintptr_t);
 289
 290 /*
 291  * retrieve pointer to buffer associated with buf_t
 292  * if non-null, than guaranteed to be kernel addressable
 293  * size of buffer can be retrieved via buf_size
 294  * size of valid data can be retrieved via buf_count
 295  * if NULL, than use buf_map/buf_unmap to manage access to the underlying storage
 296  */
 297 uintptr_t buf_dataptr(buf_t);
 298
 299 /*
 300  * return the vnode_t associated with buf_t
 301  */
 302 vnode_t buf_vnode(buf_t);
 303
 304 /*
 305  * assign vnode_t to buf_t... the
 306  * device currently associated with
 307  * but_t is not changed.
 308  */
 309 void    buf_setvnode(buf_t, vnode_t);
 310
 311 /*
 312  * return the dev_t associated with buf_t
 313  */
 314 dev_t   buf_device(buf_t);
 315
 316 /*
 317  * assign the dev_t associated with vnode_t
 318  * to buf_t
 319  */
 320 errno_t buf_setdevice(buf_t, vnode_t);
 321
 322 errno_t buf_strategy(vnode_t, void *);
 323
 324 /*
 325  * flags for buf_invalblkno
 326  */
 327 #define BUF_WAIT        0x01
 328
 329 errno_t buf_invalblkno(vnode_t, daddr64_t, int);
 330
 331
 332 /*
 333  * return the callback function pointer
 334  * if the callback is still valid
 335  * returns NULL if a buffer that was not
 336  * allocated via buf_alloc is specified
 337  * or if a callback has not been set or
 338  * it has already fired...
 339  */
 340 void * buf_callback(buf_t);
 341
 342 /*
 343  * assign a one-shot callback function (driven from biodone)
 344  * to a buf_t allocated via buf_alloc... a caller specified
 345  * arg is passed to the callback function
 346  */
 347 errno_t buf_setcallback(buf_t, void (*)(buf_t, void *), void *);
 348
 349 /*
 350  * add a upl_t to a buffer allocated via buf_alloc
 351  * and set the offset into the upl_t (must be page
 352  * aligned).
 353  */
 354 errno_t buf_setupl(buf_t, upl_t, uint32_t);
 355
 356 /*
 357  * allocate a buf_t that is a clone of the buf_t
 358  * passed in, but whose I/O range is a subset...
 359  * if a callback routine is specified, it will
 360  * be called from buf_biodone with the bp and
 361  * arg specified.
 362  * it must be freed via buf_free
 363  */
 364 buf_t   buf_clone(buf_t, int, int, void (*)(buf_t, void *), void *);
 365
 366 /*
 367  * allocate a buf_t associated with vnode_t
 368  * that has NO storage associated with it
 369  * but is suitable for use in issuing I/Os
 370  * after storage has been assigned via buf_setdataptr
 371  * or buf_addupl
 372  */
 373 buf_t   buf_alloc(vnode_t);
 374
 375 /*
 376  * free a buf_t that was allocated via buf_alloc
 377  * any private storage associated with buf_t is the
 378  * responsiblity of the caller to release
 379  */
 380 void    buf_free(buf_t);
 381
 382 /*
 383  * flags for buf_invalidateblks
 384  */
 385 #define BUF_WRITE_DATA  0x0001          /* write data blocks first */
 386 #define BUF_SKIP_META   0x0002          /* skip over metadata blocks */
 387
 388 int     buf_invalidateblks(vnode_t, int, int, int);
 389 /*
 390  * flags for buf_flushdirtyblks and buf_iterate
 391  */
 392 #define BUF_SKIP_NONLOCKED      0x01
 393 #define BUF_SKIP_LOCKED         0x02
 394
 395 void    buf_flushdirtyblks(vnode_t, int, int, char *);
 396 void    buf_iterate(vnode_t, int (*)(buf_t, void *), int, void *);
 397
 398 #define BUF_RETURNED            0
 399 #define BUF_RETURNED_DONE       1
 400 #define BUF_CLAIMED             2
 401 #define BUF_CLAIMED_DONE        3
 402
 403 /*
 404  * zero the storage associated with buf_t
 405  */
 406 void    buf_clear(buf_t);
 407
 408 errno_t buf_bawrite(buf_t);
 409 errno_t buf_bdwrite(buf_t);
 410 errno_t buf_bwrite(buf_t);
 411
 412 void    buf_biodone(buf_t);
 413 errno_t buf_biowait(buf_t);
 414 void    buf_brelse(buf_t);
 415
 416 errno_t buf_bread(vnode_t, daddr64_t, int, ucred_t, buf_t *);
 417 errno_t buf_breadn(vnode_t, daddr64_t, int, daddr64_t *, int *, int, ucred_t, buf_t *);
 418 errno_t buf_meta_bread(vnode_t, daddr64_t, int, ucred_t, buf_t *);
 419 errno_t buf_meta_breadn(vnode_t, daddr64_t, int, daddr64_t *, int *, int, ucred_t, buf_t *);
 420
 421 u_int   minphys(buf_t bp);
 422 int     physio(void (*)(buf_t), buf_t, dev_t, int ,  u_int (*)(buf_t), struct uio *, int );
 423
 424
 425 /*
 426  * Flags for operation type in getblk()
 427  */
 428 #define BLK_READ        0x01    /* buffer for read */
 429 #define BLK_WRITE       0x02    /* buffer for write */
 430 #define BLK_META        0x10    /* buffer for metadata */
 431 /*
 432  * modifier for above flags...  if set, getblk will only return
 433  * a bp that is already valid... i.e. found in the cache
 434  */
 435 #define BLK_ONLYVALID   0x80000000
 436
 437 /* timeout is in msecs */
 438 buf_t   buf_getblk(vnode_t, daddr64_t, int, int, int, int);
 439 buf_t   buf_geteblk(int);
 440
 441 __END_DECLS
 442
 443
 444 /* Macros to clear/set/test flags. */
 445 #define SET(t, f)       (t) |= (f)
 446 #define CLR(t, f)       (t) &= ~(f)
 447 #define ISSET(t, f)     ((t) & (f))
 448
 449
 450 #endif /* !_SYS_BUF_H_ */