bsd/ufs/ffs/ffs_inode.c

   1 /*
   2  * Copyright (c) 2000 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  *
  33  * Redistribution and use in source and binary forms, with or without
  34  * modification, are permitted provided that the following conditions
  35  * are met:
  36  * 1. Redistributions of source code must retain the above copyright
  37  *    notice, this list of conditions and the following disclaimer.
  38  * 2. Redistributions in binary form must reproduce the above copyright
  39  *    notice, this list of conditions and the following disclaimer in the
  40  *    documentation and/or other materials provided with the distribution.
  41  * 3. All advertising materials mentioning features or use of this software
  42  *    must display the following acknowledgement:
  43  *      This product includes software developed by the University of
  44  *      California, Berkeley and its contributors.
  45  * 4. Neither the name of the University nor the names of its contributors
  46  *    may be used to endorse or promote products derived from this software
  47  *    without specific prior written permission.
  48  *
  49  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  59  * SUCH DAMAGE.
  60  *
  61  *      @(#)ffs_inode.c 8.13 (Berkeley) 4/21/95
  62  */
  63
  64 #include <rev_endian_fs.h>
  65 #include <vm/vm_pager.h>
  66
  67 #include <sys/param.h>
  68 #include <sys/systm.h>
  69 #include <sys/mount_internal.h>
  70 #include <sys/proc_internal.h>  /* for accessing p_stats */
  71 #include <sys/file.h>
  72 #include <sys/buf_internal.h>
  73 #include <sys/vnode_internal.h>
  74 #include <sys/kernel.h>
  75 #include <sys/malloc.h>
  76 #include <sys/trace.h>
  77 #include <sys/resourcevar.h>
  78 #include <sys/ubc.h>
  79 #include <sys/quota.h>
  80
  81 #include <sys/vm.h>
  82
  83 #include <ufs/ufs/quota.h>
  84 #include <ufs/ufs/inode.h>
  85 #include <ufs/ufs/ufsmount.h>
  86 #include <ufs/ufs/ufs_extern.h>
  87
  88 #include <ufs/ffs/fs.h>
  89 #include <ufs/ffs/ffs_extern.h>
  90
  91 #if REV_ENDIAN_FS
  92 #include <ufs/ufs/ufs_byte_order.h>
  93 #include <libkern/OSByteOrder.h>
  94 #endif /* REV_ENDIAN_FS */
  95 #include <libkern/OSAtomic.h>
  96
  97 static int ffs_indirtrunc(struct inode *, ufs_daddr_t, ufs_daddr_t,
  98             ufs_daddr_t, int, long *);
  99
 100 /*
 101  * Update the access, modified, and inode change times as specified by the
 102  * IACCESS, IUPDATE, and ICHANGE flags respectively. The IMODIFIED flag is
 103  * used to specify that the inode needs to be updated but that the times have
 104  * already been set. The access and modified times are taken from the second
 105  * and third parameters; the inode change time is always taken from the current
 106  * time. If waitfor is set, then wait for the disk write of the inode to
 107  * complete.
 108  */
 109 int
 110 ffs_update(struct vnode *vp, struct timeval *access, struct timeval *modify, int waitfor)
 111 {
 112         register struct fs *fs;
 113         struct buf *bp;
 114         struct inode *ip;
 115         struct timeval tv;
 116         errno_t error;
 117 #if REV_ENDIAN_FS
 118         struct mount *mp=(vp)->v_mount;
 119         int rev_endian=(mp->mnt_flag & MNT_REVEND);
 120 #endif /* REV_ENDIAN_FS */
 121
 122         ip = VTOI(vp);
 123         if (vp->v_mount->mnt_flag & MNT_RDONLY) {
 124                 ip->i_flag &=
 125                     ~(IN_ACCESS | IN_CHANGE | IN_MODIFIED | IN_UPDATE);
 126                 return (0);
 127         }
 128         if ((ip->i_flag &
 129             (IN_ACCESS | IN_CHANGE | IN_MODIFIED | IN_UPDATE)) == 0)
 130                 return (0);
 131         if (ip->i_flag & IN_ACCESS)
 132                 ip->i_atime = access->tv_sec;
 133         if (ip->i_flag & IN_UPDATE) {
 134                 ip->i_mtime = modify->tv_sec;
 135                 ip->i_modrev++;
 136         }
 137         if (ip->i_flag & IN_CHANGE) {
 138                 microtime(&tv);
 139                 ip->i_ctime = tv.tv_sec;
 140         }
 141         ip->i_flag &= ~(IN_ACCESS | IN_CHANGE | IN_MODIFIED | IN_UPDATE);
 142         fs = ip->i_fs;
 143         /*
 144          * Ensure that uid and gid are correct. This is a temporary
 145          * fix until fsck has been changed to do the update.
 146          */
 147         if (fs->fs_inodefmt < FS_44INODEFMT) {          /* XXX */
 148                 ip->i_din.di_ouid = ip->i_uid;          /* XXX */
 149                 ip->i_din.di_ogid = ip->i_gid;          /* XXX */
 150         }                                               /* XXX */
 151         if (error = buf_bread(ip->i_devvp,
 152                               (daddr64_t)((unsigned)fsbtodb(fs, ino_to_fsba(fs, ip->i_number))),
 153                 (int)fs->fs_bsize, NOCRED, &bp)) {
 154                 buf_brelse(bp);
 155                 return ((int)error);
 156         }
 157 #if REV_ENDIAN_FS
 158         if (rev_endian)
 159                 byte_swap_inode_out(ip, ((struct dinode *)buf_dataptr(bp) + ino_to_fsbo(fs, ip->i_number)));
 160         else {
 161 #endif /* REV_ENDIAN_FS */
 162         *((struct dinode *)buf_dataptr(bp) + ino_to_fsbo(fs, ip->i_number)) = ip->i_din;
 163 #if REV_ENDIAN_FS
 164         }
 165 #endif /* REV_ENDIAN_FS */
 166
 167         if (waitfor && (vp->v_mount->mnt_flag & MNT_ASYNC) == 0)
 168                 return ((int)buf_bwrite(bp));
 169         else {
 170                 buf_bdwrite(bp);
 171                 return (0);
 172         }
 173 }
 174
 175
 176 #define SINGLE  0       /* index of single indirect block */
 177 #define DOUBLE  1       /* index of double indirect block */
 178 #define TRIPLE  2       /* index of triple indirect block */
 179
 180 int
 181 ffs_truncate_internal(vnode_t ovp, off_t length, int flags, ucred_t cred)
 182 {
 183         struct inode    *oip;
 184         struct fs       *fs;
 185         ufs_daddr_t lastblock;
 186         ufs_daddr_t bn, lbn, lastiblock[NIADDR], indir_lbn[NIADDR];
 187         ufs_daddr_t oldblks[NDADDR + NIADDR], newblks[NDADDR + NIADDR];
 188         buf_t   bp;
 189         int     offset, size, level, i;
 190         long    count, nblocks, vflags, blocksreleased = 0;
 191         struct  timeval tv;
 192         int     aflags, error, allerror;
 193         off_t   osize;
 194         int     devBlockSize=0;
 195 #if QUOTA
 196         int64_t change;   /* in bytes */
 197 #endif /* QUOTA */
 198
 199         if (length < 0)
 200                 return (EINVAL);
 201
 202         oip = VTOI(ovp);
 203         fs = oip->i_fs;
 204
 205         if (length > fs->fs_maxfilesize)
 206                 return (EFBIG);
 207
 208         microtime(&tv);
 209         if (ovp->v_type == VLNK &&
 210             oip->i_size < ovp->v_mount->mnt_maxsymlinklen) {
 211 #if DIAGNOSTIC
 212                 if (length != 0)
 213                         panic("ffs_truncate: partial truncate of symlink");
 214 #endif
 215                 bzero((char *)&oip->i_shortlink, (u_int)oip->i_size);
 216                 oip->i_size = 0;
 217                 oip->i_flag |= IN_CHANGE | IN_UPDATE;
 218                 return (ffs_update(ovp, &tv, &tv, 1));
 219         }
 220
 221         if (oip->i_size == length) {
 222                 oip->i_flag |= IN_CHANGE | IN_UPDATE;
 223                 return (ffs_update(ovp, &tv, &tv, 0));
 224         }
 225 #if QUOTA
 226         if (error = getinoquota(oip))
 227                 return (error);
 228 #endif
 229         osize = oip->i_size;
 230
 231         /*
 232          * Lengthen the size of the file. We must ensure that the
 233          * last byte of the file is allocated. Since the smallest
 234          * value of osize is 0, length will be at least 1.
 235          */
 236         if (osize < length) {
 237                 offset = blkoff(fs, length - 1);
 238                 lbn = lblkno(fs, length - 1);
 239                 aflags = B_CLRBUF;
 240                 if (flags & IO_SYNC)
 241                         aflags |= B_SYNC;
 242                 if (error = ffs_balloc(oip, lbn, offset + 1, cred, &bp, aflags, 0))
 243                         return (error);
 244                 oip->i_size = length;
 245
 246                 if (UBCINFOEXISTS(ovp)) {
 247                         buf_markinvalid(bp);
 248                         buf_bwrite(bp);
 249                         ubc_setsize(ovp, (off_t)length);
 250                 } else {
 251                         if (aflags & B_SYNC)
 252                                 buf_bwrite(bp);
 253                         else
 254                                 buf_bawrite(bp);
 255                 }
 256                 oip->i_flag |= IN_CHANGE | IN_UPDATE;
 257                 return (ffs_update(ovp, &tv, &tv, 1));
 258         }
 259         /*
 260          * Shorten the size of the file. If the file is not being
 261          * truncated to a block boundry, the contents of the
 262          * partial block following the end of the file must be
 263          * zero'ed in case it ever become accessable again because
 264          * of subsequent file growth.
 265          */
 266         if (UBCINFOEXISTS(ovp))
 267                 ubc_setsize(ovp, (off_t)length);
 268
 269         vflags = ((length > 0) ? BUF_WRITE_DATA : 0) | BUF_SKIP_META;
 270
 271         if (vflags & BUF_WRITE_DATA)
 272                 ffs_fsync_internal(ovp, MNT_WAIT);
 273         allerror = buf_invalidateblks(ovp, vflags, 0, 0);
 274
 275         offset = blkoff(fs, length);
 276         if (offset == 0) {
 277                 oip->i_size = length;
 278         } else {
 279                 lbn = lblkno(fs, length);
 280                 aflags = B_CLRBUF;
 281                 if (flags & IO_SYNC)
 282                         aflags |= B_SYNC;
 283                 if (error = ffs_balloc(oip, lbn, offset, cred, &bp, aflags, 0))
 284                         return (error);
 285                 oip->i_size = length;
 286                 size = blksize(fs, oip, lbn);
 287                 bzero((char *)buf_dataptr(bp) + offset, (u_int)(size - offset));
 288                 allocbuf(bp, size);
 289                 if (UBCINFOEXISTS(ovp)) {
 290                         buf_markinvalid(bp);
 291                         buf_bwrite(bp);
 292                 } else {
 293                         if (aflags & B_SYNC)
 294                                 buf_bwrite(bp);
 295                         else
 296                                 buf_bawrite(bp);
 297                 }
 298         }
 299         /*
 300          * Calculate index into inode's block list of
 301          * last direct and indirect blocks (if any)
 302          * which we want to keep.  Lastblock is -1 when
 303          * the file is truncated to 0.
 304          */
 305         lastblock = lblkno(fs, length + fs->fs_bsize - 1) - 1;
 306         lastiblock[SINGLE] = lastblock - NDADDR;
 307         lastiblock[DOUBLE] = lastiblock[SINGLE] - NINDIR(fs);
 308         lastiblock[TRIPLE] = lastiblock[DOUBLE] - NINDIR(fs) * NINDIR(fs);
 309
 310         devBlockSize = vfs_devblocksize(vnode_mount(ovp));
 311         nblocks = btodb(fs->fs_bsize, devBlockSize);
 312
 313         /*
 314          * Update file and block pointers on disk before we start freeing
 315          * blocks.  If we crash before free'ing blocks below, the blocks
 316          * will be returned to the free list.  lastiblock values are also
 317          * normalized to -1 for calls to ffs_indirtrunc below.
 318          */
 319         bcopy((caddr_t)&oip->i_db[0], (caddr_t)oldblks, sizeof oldblks);
 320         for (level = TRIPLE; level >= SINGLE; level--)
 321                 if (lastiblock[level] < 0) {
 322                         oip->i_ib[level] = 0;
 323                         lastiblock[level] = -1;
 324                 }
 325         for (i = NDADDR - 1; i > lastblock; i--)
 326                 oip->i_db[i] = 0;
 327         oip->i_flag |= IN_CHANGE | IN_UPDATE;
 328         if (error = ffs_update(ovp, &tv, &tv, MNT_WAIT))
 329                 allerror = error;
 330         /*
 331          * Having written the new inode to disk, save its new configuration
 332          * and put back the old block pointers long enough to process them.
 333          * Note that we save the new block configuration so we can check it
 334          * when we are done.
 335          */
 336         bcopy((caddr_t)&oip->i_db[0], (caddr_t)newblks, sizeof newblks);
 337         bcopy((caddr_t)oldblks, (caddr_t)&oip->i_db[0], sizeof oldblks);
 338         oip->i_size = osize;
 339
 340         vflags = ((length > 0) ? BUF_WRITE_DATA : 0) | BUF_SKIP_META;
 341
 342         if (vflags & BUF_WRITE_DATA)
 343                 ffs_fsync_internal(ovp, MNT_WAIT);
 344         allerror = buf_invalidateblks(ovp, vflags, 0, 0);
 345
 346         /*
 347          * Indirect blocks first.
 348          */
 349         indir_lbn[SINGLE] = -NDADDR;
 350         indir_lbn[DOUBLE] = indir_lbn[SINGLE] - NINDIR(fs) - 1;
 351         indir_lbn[TRIPLE] = indir_lbn[DOUBLE] - NINDIR(fs) * NINDIR(fs) - 1;
 352         for (level = TRIPLE; level >= SINGLE; level--) {
 353                 bn = oip->i_ib[level];
 354                 if (bn != 0) {
 355                         error = ffs_indirtrunc(oip, indir_lbn[level],
 356                             fsbtodb(fs, bn), lastiblock[level], level, &count);
 357                         if (error)
 358                                 allerror = error;
 359                         blocksreleased += count;
 360                         if (lastiblock[level] < 0) {
 361                                 oip->i_ib[level] = 0;
 362                                 ffs_blkfree(oip, bn, fs->fs_bsize);
 363                                 blocksreleased += nblocks;
 364                         }
 365                 }
 366                 if (lastiblock[level] >= 0)
 367                         goto done;
 368         }
 369
 370         /*
 371          * All whole direct blocks or frags.
 372          */
 373         for (i = NDADDR - 1; i > lastblock; i--) {
 374                 register long bsize;
 375
 376                 bn = oip->i_db[i];
 377                 if (bn == 0)
 378                         continue;
 379                 oip->i_db[i] = 0;
 380                 bsize = blksize(fs, oip, i);
 381                 ffs_blkfree(oip, bn, bsize);
 382                 blocksreleased += btodb(bsize, devBlockSize);
 383         }
 384         if (lastblock < 0)
 385                 goto done;
 386
 387         /*
 388          * Finally, look for a change in size of the
 389          * last direct block; release any frags.
 390          */
 391         bn = oip->i_db[lastblock];
 392         if (bn != 0) {
 393                 long oldspace, newspace;
 394
 395                 /*
 396                  * Calculate amount of space we're giving
 397                  * back as old block size minus new block size.
 398                  */
 399                 oldspace = blksize(fs, oip, lastblock);
 400                 oip->i_size = length;
 401                 newspace = blksize(fs, oip, lastblock);
 402                 if (newspace == 0)
 403                         panic("itrunc: newspace");
 404                 if (oldspace - newspace > 0) {
 405                         /*
 406                          * Block number of space to be free'd is
 407                          * the old block # plus the number of frags
 408                          * required for the storage we're keeping.
 409                          */
 410                         bn += numfrags(fs, newspace);
 411                         ffs_blkfree(oip, bn, oldspace - newspace);
 412                         blocksreleased += btodb(oldspace - newspace, devBlockSize);
 413                 }
 414         }
 415 done:
 416 #if DIAGNOSTIC
 417         for (level = SINGLE; level <= TRIPLE; level++)
 418                 if (newblks[NDADDR + level] != oip->i_ib[level])
 419                         panic("itrunc1");
 420         for (i = 0; i < NDADDR; i++)
 421                 if (newblks[i] != oip->i_db[i])
 422                         panic("itrunc2");
 423         if (length == 0 &&
 424             (vnode_hasdirtyblks(ovp) || vnode_hascleanblks(ovp)))
 425                 panic("itrunc3");
 426 #endif /* DIAGNOSTIC */
 427         /*
 428          * Put back the real size.
 429          */
 430         oip->i_size = length;
 431         oip->i_blocks -= blocksreleased;
 432         if (oip->i_blocks < 0)                  /* sanity */
 433                 oip->i_blocks = 0;
 434         oip->i_flag |= IN_CHANGE;
 435 #if QUOTA
 436         change = dbtob((int64_t)blocksreleased,devBlockSize);
 437         (void) chkdq(oip, -change, NOCRED, 0);
 438 #endif
 439         return (allerror);
 440 }
 441
 442 /*
 443  * Release blocks associated with the inode ip and stored in the indirect
 444  * block bn.  Blocks are free'd in LIFO order up to (but not including)
 445  * lastbn.  If level is greater than SINGLE, the block is an indirect block
 446  * and recursive calls to indirtrunc must be used to cleanse other indirect
 447  * blocks.
 448  *
 449  * NB: triple indirect blocks are untested.
 450  */
 451 static int
 452 ffs_indirtrunc(ip, lbn, dbn, lastbn, level, countp)
 453         register struct inode *ip;
 454         ufs_daddr_t lbn, lastbn;
 455         ufs_daddr_t dbn;
 456         int level;
 457         long *countp;
 458 {
 459         register int i;
 460         struct buf *bp;
 461         struct buf *tbp;
 462         register struct fs *fs = ip->i_fs;
 463         register ufs_daddr_t *bap;
 464         struct vnode *vp=ITOV(ip);
 465         ufs_daddr_t *copy, nb, nlbn, last;
 466         long blkcount, factor;
 467         int nblocks, blocksreleased = 0;
 468         errno_t error = 0, allerror = 0;
 469         int devBlockSize=0;
 470         struct mount *mp=vp->v_mount;
 471 #if REV_ENDIAN_FS
 472         int rev_endian=(mp->mnt_flag & MNT_REVEND);
 473 #endif /* REV_ENDIAN_FS */
 474
 475         /*
 476          * Calculate index in current block of last
 477          * block to be kept.  -1 indicates the entire
 478          * block so we need not calculate the index.
 479          */
 480         factor = 1;
 481         for (i = SINGLE; i < level; i++)
 482                 factor *= NINDIR(fs);
 483         last = lastbn;
 484         if (lastbn > 0)
 485                 last /= factor;
 486
 487         devBlockSize = vfs_devblocksize(mp);
 488         nblocks = btodb(fs->fs_bsize, devBlockSize);
 489
 490         /* Doing a MALLOC here is asking for trouble. We can still
 491          * deadlock on pagerfile lock, in case we are running
 492          * low on memory and block in MALLOC
 493          */
 494
 495         tbp = buf_geteblk(fs->fs_bsize);
 496         copy = (ufs_daddr_t *)buf_dataptr(tbp);
 497
 498         /*
 499          * Get buffer of block pointers, zero those entries corresponding
 500          * to blocks to be free'd, and update on disk copy first.  Since
 501          * double(triple) indirect before single(double) indirect, calls
 502          * to bmap on these blocks will fail.  However, we already have
 503          * the on disk address, so we have to set the blkno field
 504          * explicitly instead of letting buf_bread do everything for us.
 505          */
 506
 507         vp = ITOV(ip);
 508         bp = buf_getblk(vp, (daddr64_t)((unsigned)lbn), (int)fs->fs_bsize, 0, 0, BLK_META);
 509
 510         if (buf_valid(bp)) {
 511                 /* Braces must be here in case trace evaluates to nothing. */
 512                 trace(TR_BREADHIT, pack(vp, fs->fs_bsize), lbn);
 513         } else {
 514                 trace(TR_BREADMISS, pack(vp, fs->fs_bsize), lbn);
 515                 OSIncrementAtomic(&current_proc()->p_stats->p_ru.ru_inblock);   /* pay for read */
 516                 buf_setflags(bp,  B_READ);
 517                 if (buf_count(bp) > buf_size(bp))
 518                         panic("ffs_indirtrunc: bad buffer size");
 519                 buf_setblkno(bp, (daddr64_t)((unsigned)dbn));
 520                 VNOP_STRATEGY(bp);
 521                 error = buf_biowait(bp);
 522         }
 523         if (error) {
 524                 buf_brelse(bp);
 525                 *countp = 0;
 526                 buf_brelse(tbp);
 527                 return ((int)error);
 528         }
 529
 530         bap = (ufs_daddr_t *)buf_dataptr(bp);
 531         bcopy((caddr_t)bap, (caddr_t)copy, (u_int)fs->fs_bsize);
 532         bzero((caddr_t)&bap[last + 1],
 533           (u_int)(NINDIR(fs) - (last + 1)) * sizeof (ufs_daddr_t));
 534         if (last == -1)
 535                 buf_markinvalid(bp);
 536         if (last != -1 && (vp)->v_mount->mnt_flag & MNT_ASYNC) {
 537                 error = 0;
 538                 buf_bdwrite(bp);
 539         } else {
 540                 error = buf_bwrite(bp);
 541                 if (error)
 542                         allerror = error;
 543         }
 544         bap = copy;
 545
 546         /*
 547          * Recursively free totally unused blocks.
 548          */
 549         for (i = NINDIR(fs) - 1, nlbn = lbn + 1 - i * factor; i > last;
 550             i--, nlbn += factor) {
 551 #if     REV_ENDIAN_FS
 552                 if (rev_endian)
 553                         nb = OSSwapInt32(bap[i]);
 554                 else {
 555 #endif  /* REV_ENDIAN_FS */
 556                         nb = bap[i];
 557 #if     REV_ENDIAN_FS
 558                 }
 559 #endif  /* REV_ENDIAN_FS */
 560                 if (nb == 0)
 561                         continue;
 562                 if (level > SINGLE) {
 563                         if (error = ffs_indirtrunc(ip, nlbn, fsbtodb(fs, nb),
 564                             (ufs_daddr_t)-1, level - 1, &blkcount))
 565                                 allerror = error;
 566                         blocksreleased += blkcount;
 567                 }
 568                 ffs_blkfree(ip, nb, fs->fs_bsize);
 569                 blocksreleased += nblocks;
 570         }
 571
 572         /*
 573          * Recursively free last partial block.
 574          */
 575         if (level > SINGLE && lastbn >= 0) {
 576                 last = lastbn % factor;
 577 #if     REV_ENDIAN_FS
 578                 if (rev_endian)
 579                         nb = OSSwapInt32(bap[i]);
 580                 else {
 581 #endif  /* REV_ENDIAN_FS */
 582                         nb = bap[i];
 583 #if     REV_ENDIAN_FS
 584                 }
 585 #endif  /* REV_ENDIAN_FS */
 586                 if (nb != 0) {
 587                         if (error = ffs_indirtrunc(ip, nlbn, fsbtodb(fs, nb),
 588                             last, level - 1, &blkcount))
 589                                 allerror = error;
 590                         blocksreleased += blkcount;
 591                 }
 592         }
 593         buf_brelse(tbp);
 594         *countp = blocksreleased;
 595         return ((int)allerror);
 596 }
 597