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