bsd/ufs/ufs/ufs_bmap.c

   1 /*
   2  * Copyright (c) 2000 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) 1989, 1991, 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  *      @(#)ufs_bmap.c  8.7 (Berkeley) 3/21/95
  61  */
  62 /*
  63  * HISTORY
  64  * 11-July-97  Umesh Vaishampayan (umeshv@apple.com)
  65  *      Cleanup. Fixed compilation error when tracing is turned on.
  66  */
  67 #include <rev_endian_fs.h>
  68 #include <sys/param.h>
  69 #include <sys/buf.h>
  70 #include <sys/proc.h>
  71 #include <sys/vnode.h>
  72 #include <sys/mount.h>
  73 #include <sys/resourcevar.h>
  74 #include <sys/trace.h>
  75
  76 #include <miscfs/specfs/specdev.h>
  77
  78 #include <ufs/ufs/quota.h>
  79 #include <ufs/ufs/inode.h>
  80 #include <ufs/ufs/ufsmount.h>
  81 #include <ufs/ufs/ufs_extern.h>
  82 #if REV_ENDIAN_FS
  83 #include <ufs/ufs/ufs_byte_order.h>
  84 #include <architecture/byte_order.h>
  85 #endif /* REV_ENDIAN_FS */
  86
  87 /*
  88  * Bmap converts a the logical block number of a file to its physical block
  89  * number on the disk. The conversion is done by using the logical block
  90  * number to index into the array of block pointers described by the dinode.
  91  */
  92 int
  93 ufs_bmap(ap)
  94         struct vop_bmap_args /* {
  95                 struct vnode *a_vp;
  96                 ufs_daddr_t a_bn;
  97                 struct vnode **a_vpp;
  98                 ufs_daddr_t *a_bnp;
  99                 int *a_runp;
 100         } */ *ap;
 101 {
 102         /*
 103          * Check for underlying vnode requests and ensure that logical
 104          * to physical mapping is requested.
 105          */
 106         if (ap->a_vpp != NULL)
 107                 *ap->a_vpp = VTOI(ap->a_vp)->i_devvp;
 108         if (ap->a_bnp == NULL)
 109                 return (0);
 110
 111         return (ufs_bmaparray(ap->a_vp, ap->a_bn, ap->a_bnp, NULL, NULL,
 112             ap->a_runp));
 113 }
 114
 115 /*
 116  * Indirect blocks are now on the vnode for the file.  They are given negative
 117  * logical block numbers.  Indirect blocks are addressed by the negative
 118  * address of the first data block to which they point.  Double indirect blocks
 119  * are addressed by one less than the address of the first indirect block to
 120  * which they point.  Triple indirect blocks are addressed by one less than
 121  * the address of the first double indirect block to which they point.
 122  *
 123  * ufs_bmaparray does the bmap conversion, and if requested returns the
 124  * array of logical blocks which must be traversed to get to a block.
 125  * Each entry contains the offset into that block that gets you to the
 126  * next block and the disk address of the block (if it is assigned).
 127  */
 128
 129 int
 130 ufs_bmaparray(vp, bn, bnp, ap, nump, runp)
 131         struct vnode *vp;
 132         ufs_daddr_t bn;
 133         ufs_daddr_t *bnp;
 134         struct indir *ap;
 135         int *nump;
 136         int *runp;
 137 {
 138         register struct inode *ip;
 139         struct buf *bp;
 140         struct ufsmount *ump;
 141         struct mount *mp;
 142         struct vnode *devvp;
 143         struct indir a[NIADDR], *xap;
 144         ufs_daddr_t daddr;
 145         long metalbn;
 146         int error, maxrun, num;
 147 #if REV_ENDIAN_FS
 148         int rev_endian=0;
 149 #endif /* REV_ENDIAN_FS */
 150
 151         ip = VTOI(vp);
 152         mp = vp->v_mount;
 153         ump = VFSTOUFS(mp);
 154
 155 #if REV_ENDIAN_FS
 156         rev_endian=(mp->mnt_flag & MNT_REVEND);
 157 #endif /* REV_ENDIAN_FS */
 158
 159 #if DIAGNOSTIC
 160         if (ap != NULL && nump == NULL || ap == NULL && nump != NULL)
 161                 panic("ufs_bmaparray: invalid arguments");
 162 #endif
 163
 164         if (runp) {
 165                 /*
 166                  * XXX
 167                  * If MAXPHYSIO is the largest transfer the disks can handle,
 168                  * we probably want maxrun to be 1 block less so that we
 169                  * don't create a block larger than the device can handle.
 170                  */
 171                 *runp = 0;
 172                 maxrun = MAXPHYSIO / mp->mnt_stat.f_iosize - 1;
 173         }
 174
 175         xap = ap == NULL ? a : ap;
 176         if (!nump)
 177                 nump = &num;
 178         if (error = ufs_getlbns(vp, bn, xap, nump))
 179                 return (error);
 180
 181         num = *nump;
 182         if (num == 0) {
 183                 *bnp = blkptrtodb(ump, ip->i_db[bn]);
 184                 if (*bnp == 0)
 185                         *bnp = -1;
 186                 else if (runp)
 187                         for (++bn; bn < NDADDR && *runp < maxrun &&
 188                             is_sequential(ump, ip->i_db[bn - 1], ip->i_db[bn]);
 189                             ++bn, ++*runp);
 190                 return (0);
 191         }
 192
 193
 194         /* Get disk address out of indirect block array */
 195         daddr = ip->i_ib[xap->in_off];
 196
 197         devvp = VFSTOUFS(vp->v_mount)->um_devvp;
 198         for (bp = NULL, ++xap; --num; ++xap) {
 199                 /*
 200                  * Exit the loop if there is no disk address assigned yet and
 201                  * the indirect block isn't in the cache, or if we were
 202                  * looking for an indirect block and we've found it.
 203                  */
 204
 205                 metalbn = xap->in_lbn;
 206                 if (daddr == 0 && !incore(vp, metalbn) || metalbn == bn)
 207                         break;
 208                 /*
 209                  * If we get here, we've either got the block in the cache
 210                  * or we have a disk address for it, go fetch it.
 211                  */
 212                 if (bp)
 213                         brelse(bp);
 214
 215                 xap->in_exists = 1;
 216                 bp = getblk(vp, metalbn, mp->mnt_stat.f_iosize, 0, 0, BLK_META);
 217                 if (bp->b_flags & (B_DONE | B_DELWRI)) {
 218                         trace(TR_BREADHIT, pack(vp, mp->mnt_stat.f_iosize), metalbn);
 219                 }
 220 #if DIAGNOSTIC
 221                 else if (!daddr)
 222                         panic("ufs_bmaparry: indirect block not in cache");
 223 #endif
 224                 else {
 225                         trace(TR_BREADMISS, pack(vp, mp->mnt_stat.f_iosize), metalbn);
 226                         bp->b_blkno = blkptrtodb(ump, daddr);
 227                         bp->b_flags |= B_READ;
 228                         VOP_STRATEGY(bp);
 229                         current_proc()->p_stats->p_ru.ru_inblock++;     /* XXX */
 230                         if (error = biowait(bp)) {
 231                                 brelse(bp);
 232                                 return (error);
 233                         }
 234                 }
 235
 236                 daddr = ((ufs_daddr_t *)bp->b_data)[xap->in_off];
 237 #if REV_ENDIAN_FS
 238                 if (rev_endian)
 239                         daddr = NXSwapLong(daddr);
 240 #endif /* REV_ENDIAN_FS */
 241                 if (num == 1 && daddr && runp) {
 242 #if REV_ENDIAN_FS
 243                 if (rev_endian) {
 244                         for (bn = xap->in_off + 1;
 245                             bn < MNINDIR(ump) && *runp < maxrun &&
 246                             is_sequential(ump,
 247                             NXSwapLong(((ufs_daddr_t *)bp->b_data)[bn - 1]),
 248                             NXSwapLong(((ufs_daddr_t *)bp->b_data)[bn]));
 249                             ++bn, ++*runp);
 250                  } else {
 251 #endif /* REV_ENDIAN_FS */
 252                         for (bn = xap->in_off + 1;
 253                             bn < MNINDIR(ump) && *runp < maxrun &&
 254                             is_sequential(ump,
 255                             ((ufs_daddr_t *)bp->b_data)[bn - 1],
 256                             ((ufs_daddr_t *)bp->b_data)[bn]);
 257                             ++bn, ++*runp);
 258 #if REV_ENDIAN_FS
 259                 }
 260 #endif /* REV_ENDIAN_FS */
 261                 }
 262         }
 263         if (bp)
 264                 brelse(bp);
 265
 266         daddr = blkptrtodb(ump, daddr);
 267         *bnp = daddr == 0 ? -1 : daddr;
 268         return (0);
 269 }
 270
 271 /*
 272  * Create an array of logical block number/offset pairs which represent the
 273  * path of indirect blocks required to access a data block.  The first "pair"
 274  * contains the logical block number of the appropriate single, double or
 275  * triple indirect block and the offset into the inode indirect block array.
 276  * Note, the logical block number of the inode single/double/triple indirect
 277  * block appears twice in the array, once with the offset into the i_ib and
 278  * once with the offset into the page itself.
 279  */
 280 int
 281 ufs_getlbns(vp, bn, ap, nump)
 282         struct vnode *vp;
 283         ufs_daddr_t bn;
 284         struct indir *ap;
 285         int *nump;
 286 {
 287         long metalbn, realbn;
 288         struct ufsmount *ump;
 289         int blockcnt, i, numlevels, off;
 290
 291         ump = VFSTOUFS(vp->v_mount);
 292         if (nump)
 293                 *nump = 0;
 294         numlevels = 0;
 295         realbn = bn;
 296         if ((long)bn < 0)
 297                 bn = -(long)bn;
 298
 299         /* The first NDADDR blocks are direct blocks. */
 300         if (bn < NDADDR)
 301                 return (0);
 302
 303         /*
 304          * Determine the number of levels of indirection.  After this loop
 305          * is done, blockcnt indicates the number of data blocks possible
 306          * at the given level of indirection, and NIADDR - i is the number
 307          * of levels of indirection needed to locate the requested block.
 308          */
 309         for (blockcnt = 1, i = NIADDR, bn -= NDADDR;; i--, bn -= blockcnt) {
 310                 if (i == 0)
 311                         return (EFBIG);
 312                 blockcnt *= MNINDIR(ump);
 313                 if (bn < blockcnt)
 314                         break;
 315         }
 316
 317         /* Calculate the address of the first meta-block. */
 318         if (realbn >= 0)
 319                 metalbn = -(realbn - bn + NIADDR - i);
 320         else
 321                 metalbn = -(-realbn - bn + NIADDR - i);
 322
 323         /*
 324          * At each iteration, off is the offset into the bap array which is
 325          * an array of disk addresses at the current level of indirection.
 326          * The logical block number and the offset in that block are stored
 327          * into the argument array.
 328          */
 329         ap->in_lbn = metalbn;
 330         ap->in_off = off = NIADDR - i;
 331         ap->in_exists = 0;
 332         ap++;
 333         for (++numlevels; i <= NIADDR; i++) {
 334                 /* If searching for a meta-data block, quit when found. */
 335                 if (metalbn == realbn)
 336                         break;
 337
 338                 blockcnt /= MNINDIR(ump);
 339                 off = (bn / blockcnt) % MNINDIR(ump);
 340
 341                 ++numlevels;
 342                 ap->in_lbn = metalbn;
 343                 ap->in_off = off;
 344                 ap->in_exists = 0;
 345                 ++ap;
 346
 347                 metalbn -= -1 + off * blockcnt;
 348         }
 349         if (nump)
 350                 *nump = numlevels;
 351         return (0);
 352 }
 353 /*
 354  * Cmap converts a the file offset of a file to its physical block
 355  * number on the disk And returns  contiguous size for transfer.
 356  */
 357 int
 358 ufs_cmap(ap)
 359         struct vop_cmap_args /* {
 360                 struct vnode *a_vp;
 361                 off_t a_foffset;
 362                 size_t a_size;
 363                 daddr_t *a_bpn;
 364                 size_t *a_run;
 365                 void *a_poff;
 366         } */ *ap;
 367 {
 368         struct vnode * vp = ap->a_vp;
 369         ufs_daddr_t *bnp = ap->a_bpn;
 370         size_t *runp = ap->a_run;
 371         int size = ap->a_size;
 372         daddr_t bn;
 373         int nblks;
 374         register struct inode *ip;
 375         ufs_daddr_t daddr = 0;
 376         int devBlockSize=0;
 377         struct fs *fs;
 378         int retsize=0;
 379         int error=0;
 380
 381         ip = VTOI(vp);
 382         fs = ip->i_fs;
 383
 384
 385         if (blkoff(fs, ap->a_foffset)) {
 386                 panic("ufs_cmap; allocation requested inside a block");
 387         }
 388
 389         bn = (daddr_t)lblkno(fs, ap->a_foffset);
 390         VOP_DEVBLOCKSIZE(ip->i_devvp, &devBlockSize);
 391
 392         if (size % devBlockSize) {
 393                 panic("ufs_cmap: size is not multiple of device block size\n");
 394         }
 395
 396         if (error =  VOP_BMAP(vp, bn, (struct vnode **) 0, &daddr, &nblks)) {
 397                         return(error);
 398         }
 399
 400         retsize = nblks * fs->fs_bsize;
 401
 402         if (bnp)
 403                 *bnp = daddr;
 404
 405         if (ap->a_poff)
 406                 *(int *)ap->a_poff = 0;
 407
 408         if (daddr == -1) {
 409                 if (size < fs->fs_bsize) {
 410                         retsize = fragroundup(fs, size);
 411                         if(size >= retsize)
 412                                 *runp = retsize;
 413                         else
 414                                 *runp = size;
 415                 } else {
 416                         *runp = fs->fs_bsize;
 417                 }
 418                 return(0);
 419         }
 420
 421         if (runp) {
 422                 if ((size < fs->fs_bsize)) {
 423                         *runp = size;
 424                         return(0);
 425                 }
 426                 if (retsize) {
 427                         retsize += fs->fs_bsize;
 428                         if(size >= retsize)
 429                                 *runp = retsize;
 430                         else
 431                                 *runp = size;
 432                 } else {
 433                         if (size < fs->fs_bsize) {
 434                                 retsize = fragroundup(fs, size);
 435                                 if(size >= retsize)
 436                                         *runp = retsize;
 437                                 else
 438                                         *runp = size;
 439                         } else {
 440                                 *runp = fs->fs_bsize;
 441                         }
 442                 }
 443         }
 444         return (0);
 445 }
 446
 447
 448 #if NOTTOBEUSED
 449 /*
 450  * Cmap converts a the file offset of a file to its physical block
 451  * number on the disk And returns  contiguous size for transfer.
 452  */
 453 int
 454 ufs_cmap(ap)
 455         struct vop_cmap_args /* {
 456                 struct vnode *a_vp;
 457                 off_t a_foffset;
 458                 size_t a_size;
 459                 daddr_t *a_bpn;
 460                 size_t *a_run;
 461                 void *a_poff;
 462         } */ *ap;
 463 {
 464         struct vnode * vp = ap->a_vp;
 465         ufs_daddr_t *bnp = ap->a_bpn;
 466         size_t *runp = ap->a_run;
 467         daddr_t bn;
 468         int nblks, blks;
 469         int *nump;
 470         register struct inode *ip;
 471         struct buf *bp;
 472         struct ufsmount *ump;
 473         struct mount *mp;
 474         struct vnode *devvp;
 475         struct indir a[NIADDR], *xap;
 476         ufs_daddr_t daddr;
 477         long metalbn;
 478         int error, maxrun, num;
 479         int devBlockSize=0;
 480         struct fs *fs;
 481         int size = ap->a_size;
 482         int block_offset=0;
 483         int retsize=0;
 484 #if 1
 485         daddr_t orig_blkno;
 486         daddr_t orig_bblkno;
 487 #endif /* 1 */
 488 #if REV_ENDIAN_FS
 489         int rev_endian=0;
 490 #endif /* REV_ENDIAN_FS */
 491
 492         ip = VTOI(vp);
 493         fs = ip->i_fs;
 494
 495         mp = vp->v_mount;
 496         ump = VFSTOUFS(mp);
 497
 498         VOP_DEVBLOCKSIZE(ip->i_devvp, &devBlockSize);
 499         bn = (daddr_t)lblkno(fs, ap->a_foffset);
 500
 501         if (size % devBlockSize) {
 502                 panic("ufs_cmap: size is not multiple of device block size\n");
 503         }
 504
 505         block_offset = blkoff(fs, ap->a_foffset);
 506         if (block_offset) {
 507                 panic("ufs_cmap; allocation requested inside a block");
 508         }
 509
 510 #if 1
 511         VOP_OFFTOBLK(vp, ap->a_foffset, & orig_blkno);
 512 #endif /* 1 */
 513         /* less than block size and not block offset aligned */
 514         if ( (size < fs->fs_bsize) && fragoff(fs, size) && block_offset ) {
 515                 panic("ffs_cmap: size not a mult of fragment\n");
 516         }
 517 #if 0
 518         if (size > fs->fs_bsize && fragoff(fs, size))  {
 519                 panic("ffs_cmap: more than bsize  & not a multiple of fragment\n");
 520         }
 521 #endif /* 0 */
 522 #if REV_ENDIAN_FS
 523         rev_endian=(mp->mnt_flag & MNT_REVEND);
 524 #endif /* REV_ENDIAN_FS */
 525
 526         if(runp)
 527                 *runp = 0;
 528
 529         if ( size > MAXPHYSIO)
 530                 size = MAXPHYSIO;
 531         nblks = (blkroundup(fs, size))/fs->fs_bsize;
 532
 533         xap = a;
 534         num = 0;
 535         if (error = ufs_getlbns(vp, bn, xap, &num))
 536                 return (error);
 537
 538         blks = 0;
 539         if (num == 0) {
 540                 daddr = blkptrtodb(ump, ip->i_db[bn]);
 541                 *bnp = ((daddr == 0) ? -1 : daddr);
 542                 if (daddr && runp) {
 543                         for (++bn; bn < NDADDR && blks < nblks &&
 544                             ip->i_db[bn] &&
 545                             is_sequential(ump, ip->i_db[bn - 1], ip->i_db[bn]);
 546                             ++bn, ++blks);
 547
 548                         if (blks) {
 549                                 retsize = lblktosize(fs, blks);
 550                                 if(size >= retsize)
 551                                         *runp = retsize;
 552                                 else
 553                                         *runp = size;
 554                         } else {
 555                                 if (size < fs->fs_bsize) {
 556                                         retsize = fragroundup(fs, size);
 557                                         if(size >= retsize)
 558                                                 *runp = retsize;
 559                                         else
 560                                                 *runp = size;
 561                                 } else {
 562                                         *runp = fs->fs_bsize;
 563                                 }
 564                         }
 565                         if (ap->a_poff)
 566                                 *(int *)ap->a_poff = 0;
 567                 }
 568 #if 1
 569                 if (VOP_BMAP(vp, orig_blkno, NULL, &orig_bblkno, NULL)) {
 570                         panic("vop_bmap failed\n");
 571                 }
 572                 if(daddr != orig_bblkno) {
 573                         panic("vop_bmap and vop_cmap differ\n");
 574                 }
 575 #endif /* 1 */
 576                 return (0);
 577         }
 578
 579
 580         /* Get disk address out of indirect block array */
 581         daddr = ip->i_ib[xap->in_off];
 582
 583         devvp = VFSTOUFS(vp->v_mount)->um_devvp;
 584         for (bp = NULL, ++xap; --num; ++xap) {
 585                 /*
 586                  * Exit the loop if there is no disk address assigned yet
 587                  * or if we were looking for an indirect block and we've
 588                  * found it.
 589                  */
 590
 591                 metalbn = xap->in_lbn;
 592                 if (daddr == 0  || metalbn == bn)
 593                         break;
 594                 /*
 595                  * We have a disk address for it, go fetch it.
 596                  */
 597                 if (bp)
 598                         brelse(bp);
 599
 600                 xap->in_exists = 1;
 601                 bp = getblk(vp, metalbn, mp->mnt_stat.f_iosize, 0, 0, BLK_META);
 602                 if (bp->b_flags & (B_DONE | B_DELWRI)) {
 603                         trace(TR_BREADHIT, pack(vp, mp->mnt_stat.f_iosize), metalbn);
 604                 }
 605                 else {
 606                         trace(TR_BREADMISS, pack(vp, mp->mnt_stat.f_iosize), metalbn);
 607                         bp->b_blkno = blkptrtodb(ump, daddr);
 608                         bp->b_flags |= B_READ;
 609                         VOP_STRATEGY(bp);
 610                         current_proc()->p_stats->p_ru.ru_inblock++;     /* XXX */
 611                         if (error = biowait(bp)) {
 612                                 brelse(bp);
 613                                 return (error);
 614                         }
 615                 }
 616
 617                 daddr = ((ufs_daddr_t *)bp->b_data)[xap->in_off];
 618 #if REV_ENDIAN_FS
 619                 if (rev_endian)
 620                         daddr = NXSwapLong(daddr);
 621 #endif /* REV_ENDIAN_FS */
 622                 if (num == 1 && daddr && runp) {
 623                         blks = 0;
 624 #if REV_ENDIAN_FS
 625                 if (rev_endian) {
 626                         for (bn = xap->in_off + 1;
 627                             bn < MNINDIR(ump) && blks < maxrun &&
 628                             is_sequential(ump,
 629                             NXSwapLong(((ufs_daddr_t *)bp->b_data)[bn - 1]),
 630                             NXSwapLong(((ufs_daddr_t *)bp->b_data)[bn]));
 631                             ++bn, ++blks);
 632                  } else {
 633 #endif /* REV_ENDIAN_FS */
 634                         for (bn = xap->in_off + 1;
 635                             bn < MNINDIR(ump) && blks < maxrun &&
 636                             is_sequential(ump,
 637                             ((ufs_daddr_t *)bp->b_data)[bn - 1],
 638                             ((ufs_daddr_t *)bp->b_data)[bn]);
 639                             ++bn, ++blks);
 640 #if REV_ENDIAN_FS
 641                 }
 642 #endif /* REV_ENDIAN_FS */
 643                 }
 644         }
 645         if (bp)
 646                 brelse(bp);
 647
 648         daddr = blkptrtodb(ump, daddr);
 649         *bnp = ((daddr == 0) ? -1 : daddr);
 650         if (daddr && runp) {
 651                 if (blks) {
 652                         retsize = lblktosize(fs, blks);
 653                         if(size >= retsize)
 654                                 *runp = retsize;
 655                         else
 656                                 *runp = size;
 657                 } else {
 658                                 if (size < fs->fs_bsize) {
 659                                         retsize = fragroundup(fs, size);
 660                                         if(size >= retsize)
 661                                                 *runp = retsize;
 662                                         else
 663                                                 *runp = size;
 664                                 } else {
 665                                         *runp = fs->fs_bsize;
 666                                 }
 667                         }
 668
 669         }
 670         if (daddr &&  ap->a_poff)
 671                 *(int *)ap->a_poff = 0;
 672 #if 1
 673                 if (VOP_BMAP(vp, orig_blkno, (struct vnode **) 0, &orig_bblkno, 0)) {
 674                         panic("vop_bmap failed\n");
 675                 }
 676                 if(daddr != orig_bblkno) {
 677                         panic("vop_bmap and vop_cmap differ\n");
 678                 }
 679 #endif /* 1 */
 680         return (0);
 681 }
 682 #endif /* NOTTOBEUSED */