sys/vfs/ufs/ffs_inode.c

   1 /*
   2  * Copyright (c) 1982, 1986, 1989, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  *      @(#)ffs_inode.c 8.13 (Berkeley) 4/21/95
  30  * $FreeBSD: src/sys/ufs/ffs/ffs_inode.c,v 1.56.2.5 2002/02/05 18:35:03 dillon Exp $
  31  */
  32
  33 #include "opt_quota.h"
  34
  35 #include <sys/param.h>
  36 #include <sys/systm.h>
  37 #include <sys/mount.h>
  38 #include <sys/proc.h>
  39 #include <sys/buf.h>
  40 #include <sys/vnode.h>
  41 #include <sys/kernel.h>
  42 #include <sys/malloc.h>
  43 #include <sys/resourcevar.h>
  44 #include <sys/vmmeter.h>
  45
  46 #include <vm/vm.h>
  47 #include <vm/vm_extern.h>
  48
  49 #include "quota.h"
  50 #include "ufsmount.h"
  51 #include "inode.h"
  52 #include "ufs_extern.h"
  53
  54 #include "fs.h"
  55 #include "ffs_extern.h"
  56
  57 #include <vm/vm_page2.h>
  58 #include <sys/buf2.h>
  59
  60 static int ffs_indirtrunc (struct inode *, ufs_daddr_t, ufs_daddr_t,
  61             ufs_daddr_t, int, long *);
  62
  63 /*
  64  * Update the access, modified, and inode change times as specified by the
  65  * IN_ACCESS, IN_UPDATE, and IN_CHANGE flags respectively.  Write the inode
  66  * to disk if the IN_MODIFIED flag is set (it may be set initially, or by
  67  * the timestamp update).  The IN_LAZYMOD flag is set to force a write
  68  * later if not now.  If we write now, then clear both IN_MODIFIED and
  69  * IN_LAZYMOD to reflect the presumably successful write, and if waitfor is
  70  * set, then wait for the write to complete.
  71  */
  72 int
  73 ffs_update(struct vnode *vp, int waitfor)
  74 {
  75         struct fs *fs;
  76         struct buf *bp;
  77         struct inode *ip;
  78         int error;
  79
  80         ufs_itimes(vp);
  81         ip = VTOI(vp);
  82         if ((ip->i_flag & IN_MODIFIED) == 0 && waitfor == 0)
  83                 return (0);
  84         ip->i_flag &= ~(IN_LAZYMOD | IN_MODIFIED);
  85         fs = ip->i_fs;
  86         if (fs->fs_ronly)
  87                 return (0);
  88
  89         /*
  90          * The vnode type is usually set to VBAD if an unrecoverable I/O
  91          * error has occured (such as when reading the inode).  Clear the
  92          * modified bits but do not write anything out in this case.
  93          */
  94         if (vp->v_type == VBAD)
  95                 return (0);
  96         /*
  97          * Ensure that uid and gid are correct. This is a temporary
  98          * fix until fsck has been changed to do the update.
  99          */
 100         if (fs->fs_inodefmt < FS_44INODEFMT) {          /* XXX */
 101                 ip->i_din.di_ouid = ip->i_uid;          /* XXX */
 102                 ip->i_din.di_ogid = ip->i_gid;          /* XXX */
 103         }                                               /* XXX */
 104         error = bread(ip->i_devvp,
 105                       fsbtodoff(fs, ino_to_fsba(fs, ip->i_number)),
 106                       (int)fs->fs_bsize, &bp);
 107         if (error) {
 108                 brelse(bp);
 109                 return (error);
 110         }
 111         if (DOINGSOFTDEP(vp))
 112                 softdep_update_inodeblock(ip, bp, waitfor);
 113         else if (ip->i_effnlink != ip->i_nlink)
 114                 panic("ffs_update: bad link cnt");
 115         *((struct ufs1_dinode *)bp->b_data +
 116             ino_to_fsbo(fs, ip->i_number)) = ip->i_din;
 117         if (waitfor && !DOINGASYNC(vp)) {
 118                 return (bwrite(bp));
 119         } else if (vm_page_count_severe() || buf_dirty_count_severe()) {
 120                 return (bwrite(bp));
 121         } else {
 122                 if (bp->b_bufsize == fs->fs_bsize)
 123                         bp->b_flags |= B_CLUSTEROK;
 124                 bdwrite(bp);
 125                 return (0);
 126         }
 127 }
 128
 129 #define SINGLE  0       /* index of single indirect block */
 130 #define DOUBLE  1       /* index of double indirect block */
 131 #define TRIPLE  2       /* index of triple indirect block */
 132 /*
 133  * Truncate the inode oip to at most length size, freeing the
 134  * disk blocks.
 135  */
 136 int
 137 ffs_truncate(struct vnode *vp, off_t length, int flags, struct ucred *cred)
 138 {
 139         struct vnode *ovp = vp;
 140         ufs_daddr_t lastblock;
 141         struct inode *oip;
 142         ufs_daddr_t bn, lbn, lastiblock[NIADDR], indir_lbn[NIADDR];
 143         ufs_daddr_t oldblks[NDADDR + NIADDR], newblks[NDADDR + NIADDR];
 144         struct fs *fs;
 145         struct buf *bp;
 146         int offset, size, level;
 147         long count, nblocks, blocksreleased = 0;
 148         int i;
 149         int aflags, error, allerror;
 150         off_t osize;
 151
 152         oip = VTOI(ovp);
 153         fs = oip->i_fs;
 154         if (length < 0)
 155                 return (EINVAL);
 156         if (length > fs->fs_maxfilesize)
 157                 return (EFBIG);
 158         if (ovp->v_type == VLNK &&
 159             (oip->i_size < ovp->v_mount->mnt_maxsymlinklen || oip->i_din.di_blocks == 0)) {
 160 #ifdef DIAGNOSTIC
 161                 if (length != 0)
 162                         panic("ffs_truncate: partial truncate of symlink");
 163 #endif /* DIAGNOSTIC */
 164                 bzero((char *)&oip->i_shortlink, (uint)oip->i_size);
 165                 oip->i_size = 0;
 166                 oip->i_flag |= IN_CHANGE | IN_UPDATE;
 167                 return (ffs_update(ovp, 1));
 168         }
 169         if (oip->i_size == length) {
 170                 oip->i_flag |= IN_CHANGE | IN_UPDATE;
 171                 return (ffs_update(ovp, 0));
 172         }
 173         if (fs->fs_ronly)
 174                 panic("ffs_truncate: read-only filesystem");
 175 #ifdef QUOTA
 176         error = ufs_getinoquota(oip);
 177         if (error)
 178                 return (error);
 179 #endif
 180         if (DOINGSOFTDEP(ovp)) {
 181                 if (length > 0 || softdep_slowdown(ovp)) {
 182                         /*
 183                          * If a file is only partially truncated, then
 184                          * we have to clean up the data structures
 185                          * describing the allocation past the truncation
 186                          * point. Finding and deallocating those structures
 187                          * is a lot of work. Since partial truncation occurs
 188                          * rarely, we solve the problem by syncing the file
 189                          * so that it will have no data structures left.
 190                          */
 191                         if ((error = VOP_FSYNC(ovp, MNT_WAIT, 0)) != 0)
 192                                 return (error);
 193                 } else {
 194 #ifdef QUOTA
 195                         (void) ufs_chkdq(oip, -oip->i_blocks, NOCRED, 0);
 196 #endif
 197                         softdep_setup_freeblocks(oip, length);
 198                         vinvalbuf(ovp, 0, 0, 0);
 199                         nvnode_pager_setsize(ovp, 0, fs->fs_bsize, 0);
 200                         oip->i_flag |= IN_CHANGE | IN_UPDATE;
 201                         return (ffs_update(ovp, 0));
 202                 }
 203         }
 204         osize = oip->i_size;
 205
 206         /*
 207          * Lengthen the size of the file. We must ensure that the
 208          * last byte of the file is allocated. Since the smallest
 209          * value of osize is 0, length will be at least 1.
 210          *
 211          * nvextendbuf() only breads the old buffer.  The blocksize
 212          * of the new buffer must be specified so it knows how large
 213          * to make the VM object.
 214          */
 215         if (osize < length) {
 216                 nvextendbuf(vp, osize, length,
 217                             blkoffsize(fs, oip, osize), /* oblksize */
 218                             blkoffresize(fs, length),   /* nblksize */
 219                             blkoff(fs, osize),
 220                             blkoff(fs, length),
 221                             0);
 222
 223                 aflags = B_CLRBUF;
 224                 if (flags & IO_SYNC)
 225                         aflags |= B_SYNC;
 226                 /* BALLOC will reallocate the fragment at the old EOF */
 227                 error = VOP_BALLOC(ovp, length - 1, 1, cred, aflags, &bp);
 228                 if (error)
 229                         return (error);
 230                 oip->i_size = length;
 231                 if (bp->b_bufsize == fs->fs_bsize)
 232                         bp->b_flags |= B_CLUSTEROK;
 233                 if (aflags & B_SYNC)
 234                         bwrite(bp);
 235                 else
 236                         bawrite(bp);
 237                 oip->i_flag |= IN_CHANGE | IN_UPDATE;
 238                 return (ffs_update(ovp, 1));
 239         }
 240
 241         /*
 242          * Shorten the size of the file.
 243          *
 244          * NOTE: The block size specified in nvtruncbuf() is the blocksize
 245          *       of the buffer containing length prior to any reallocation
 246          *       of the block.
 247          */
 248         allerror = nvtruncbuf(ovp, length, blkoffsize(fs, oip, length),
 249                               blkoff(fs, length), 0);
 250         offset = blkoff(fs, length);
 251         if (offset == 0) {
 252                 oip->i_size = length;
 253         } else {
 254                 lbn = lblkno(fs, length);
 255                 aflags = B_CLRBUF;
 256                 if (flags & IO_SYNC)
 257                         aflags |= B_SYNC;
 258                 error = VOP_BALLOC(ovp, length - 1, 1, cred, aflags, &bp);
 259                 if (error)
 260                         return (error);
 261
 262                 /*
 263                  * When we are doing soft updates and the UFS_BALLOC
 264                  * above fills in a direct block hole with a full sized
 265                  * block that will be truncated down to a fragment below,
 266                  * we must flush out the block dependency with an FSYNC
 267                  * so that we do not get a soft updates inconsistency
 268                  * when we create the fragment below.
 269                  *
 270                  * nvtruncbuf() may have re-dirtied the underlying block
 271                  * as part of its truncation zeroing code.  To avoid a
 272                  * 'locking against myself' panic in the second fsync we
 273                  * can simply undirty the bp since the redirtying was
 274                  * related to areas of the buffer that we are going to
 275                  * throw away anyway, and we will b*write() the remainder
 276                  * anyway down below.
 277                  */
 278                 if (DOINGSOFTDEP(ovp) && lbn < NDADDR &&
 279                     fragroundup(fs, blkoff(fs, length)) < fs->fs_bsize) {
 280                         bundirty(bp);
 281                         error = VOP_FSYNC(ovp, MNT_WAIT, 0);
 282                         if (error) {
 283                                 bdwrite(bp);
 284                                 return (error);
 285                         }
 286                 }
 287                 oip->i_size = length;
 288                 size = blksize(fs, oip, lbn);
 289 #if 0
 290                 /* remove - nvtruncbuf deals with this */
 291                 if (ovp->v_type != VDIR)
 292                         bzero((char *)bp->b_data + offset,
 293                             (uint)(size - offset));
 294 #endif
 295                 /* Kirk's code has reallocbuf(bp, size, 1) here */
 296                 allocbuf(bp, size);
 297                 if (bp->b_bufsize == fs->fs_bsize)
 298                         bp->b_flags |= B_CLUSTEROK;
 299                 if (aflags & B_SYNC)
 300                         bwrite(bp);
 301                 else
 302                         bawrite(bp);
 303         }
 304         /*
 305          * Calculate index into inode's block list of
 306          * last direct and indirect blocks (if any)
 307          * which we want to keep.  Lastblock is -1 when
 308          * the file is truncated to 0.
 309          */
 310         lastblock = lblkno(fs, length + fs->fs_bsize - 1) - 1;
 311         lastiblock[SINGLE] = lastblock - NDADDR;
 312         lastiblock[DOUBLE] = lastiblock[SINGLE] - NINDIR(fs);
 313         lastiblock[TRIPLE] = lastiblock[DOUBLE] - NINDIR(fs) * NINDIR(fs);
 314         nblocks = btodb(fs->fs_bsize);
 315
 316         /*
 317          * Update file and block pointers on disk before we start freeing
 318          * blocks.  If we crash before free'ing blocks below, the blocks
 319          * will be returned to the free list.  lastiblock values are also
 320          * normalized to -1 for calls to ffs_indirtrunc below.
 321          */
 322         for (level = TRIPLE; level >= SINGLE; level--) {
 323                 oldblks[NDADDR + level] = oip->i_ib[level];
 324                 if (lastiblock[level] < 0) {
 325                         oip->i_ib[level] = 0;
 326                         lastiblock[level] = -1;
 327                 }
 328         }
 329         for (i = 0; i < NDADDR; i++) {
 330                 oldblks[i] = oip->i_db[i];
 331                 if (i > lastblock)
 332                         oip->i_db[i] = 0;
 333         }
 334         oip->i_flag |= IN_CHANGE | IN_UPDATE;
 335         error = ffs_update(ovp, 1);
 336         if (error && allerror == 0)
 337                 allerror = error;
 338
 339         /*
 340          * Having written the new inode to disk, save its new configuration
 341          * and put back the old block pointers long enough to process them.
 342          * Note that we save the new block configuration so we can check it
 343          * when we are done.
 344          */
 345         for (i = 0; i < NDADDR; i++) {
 346                 newblks[i] = oip->i_db[i];
 347                 oip->i_db[i] = oldblks[i];
 348         }
 349         for (i = 0; i < NIADDR; i++) {
 350                 newblks[NDADDR + i] = oip->i_ib[i];
 351                 oip->i_ib[i] = oldblks[NDADDR + i];
 352         }
 353         oip->i_size = osize;
 354
 355         if (error && allerror == 0)
 356                 allerror = error;
 357
 358         /*
 359          * Indirect blocks first.
 360          */
 361         indir_lbn[SINGLE] = -NDADDR;
 362         indir_lbn[DOUBLE] = indir_lbn[SINGLE] - NINDIR(fs) - 1;
 363         indir_lbn[TRIPLE] = indir_lbn[DOUBLE] - NINDIR(fs) * NINDIR(fs) - 1;
 364         for (level = TRIPLE; level >= SINGLE; level--) {
 365                 bn = oip->i_ib[level];
 366                 if (bn != 0) {
 367                         error = ffs_indirtrunc(oip, indir_lbn[level],
 368                             fsbtodb(fs, bn), lastiblock[level], level, &count);
 369                         if (error)
 370                                 allerror = error;
 371                         blocksreleased += count;
 372                         if (lastiblock[level] < 0) {
 373                                 oip->i_ib[level] = 0;
 374                                 ffs_blkfree(oip, bn, fs->fs_bsize);
 375                                 blocksreleased += nblocks;
 376                         }
 377                 }
 378                 if (lastiblock[level] >= 0)
 379                         goto done;
 380         }
 381
 382         /*
 383          * All whole direct blocks or frags.
 384          */
 385         for (i = NDADDR - 1; i > lastblock; i--) {
 386                 long bsize;
 387
 388                 bn = oip->i_db[i];
 389                 if (bn == 0)
 390                         continue;
 391                 oip->i_db[i] = 0;
 392                 bsize = blksize(fs, oip, i);
 393                 ffs_blkfree(oip, bn, bsize);
 394                 blocksreleased += btodb(bsize);
 395         }
 396         if (lastblock < 0)
 397                 goto done;
 398
 399         /*
 400          * Finally, look for a change in size of the
 401          * last direct block; release any frags.
 402          */
 403         bn = oip->i_db[lastblock];
 404         if (bn != 0) {
 405                 long oldspace, newspace;
 406
 407                 /*
 408                  * Calculate amount of space we're giving
 409                  * back as old block size minus new block size.
 410                  */
 411                 oldspace = blksize(fs, oip, lastblock);
 412                 oip->i_size = length;
 413                 newspace = blksize(fs, oip, lastblock);
 414                 if (newspace == 0)
 415                         panic("ffs_truncate: newspace");
 416                 if (oldspace - newspace > 0) {
 417                         /*
 418                          * Block number of space to be free'd is
 419                          * the old block # plus the number of frags
 420                          * required for the storage we're keeping.
 421                          */
 422                         bn += numfrags(fs, newspace);
 423                         ffs_blkfree(oip, bn, oldspace - newspace);
 424                         blocksreleased += btodb(oldspace - newspace);
 425                 }
 426         }
 427 done:
 428 #ifdef DIAGNOSTIC
 429         for (level = SINGLE; level <= TRIPLE; level++)
 430                 if (newblks[NDADDR + level] != oip->i_ib[level])
 431                         panic("ffs_truncate1");
 432         for (i = 0; i < NDADDR; i++)
 433                 if (newblks[i] != oip->i_db[i])
 434                         panic("ffs_truncate2");
 435         if (length == 0 && !RB_EMPTY(&ovp->v_rbdirty_tree))
 436                 panic("ffs_truncate3");
 437 #endif /* DIAGNOSTIC */
 438         /*
 439          * Put back the real size.
 440          */
 441         oip->i_size = length;
 442         oip->i_blocks -= blocksreleased;
 443
 444         if (oip->i_blocks < 0)                  /* sanity */
 445                 oip->i_blocks = 0;
 446         oip->i_flag |= IN_CHANGE;
 447 #ifdef QUOTA
 448         (void) ufs_chkdq(oip, -blocksreleased, NOCRED, 0);
 449 #endif
 450         return (allerror);
 451 }
 452
 453 /*
 454  * Release blocks associated with the inode ip and stored in the indirect
 455  * block bn.  Blocks are free'd in LIFO order up to (but not including)
 456  * lastbn.  If level is greater than SINGLE, the block is an indirect block
 457  * and recursive calls to indirtrunc must be used to cleanse other indirect
 458  * blocks.
 459  *
 460  * NB: triple indirect blocks are untested.
 461  */
 462 static int
 463 ffs_indirtrunc(struct inode *ip, ufs_daddr_t lbn, ufs_daddr_t dbn,
 464                ufs_daddr_t lastbn, int level, long *countp)
 465 {
 466         int i;
 467         struct buf *bp;
 468         struct fs *fs = ip->i_fs;
 469         ufs_daddr_t *bap;
 470         struct vnode *vp;
 471         ufs_daddr_t *copy = NULL, nb, nlbn, last;
 472         long blkcount, factor;
 473         int nblocks, blocksreleased = 0;
 474         int error = 0, allerror = 0;
 475
 476         /*
 477          * Calculate index in current block of last
 478          * block to be kept.  -1 indicates the entire
 479          * block so we need not calculate the index.
 480          */
 481         factor = 1;
 482         for (i = SINGLE; i < level; i++)
 483                 factor *= NINDIR(fs);
 484         last = lastbn;
 485         if (lastbn > 0)
 486                 last /= factor;
 487         nblocks = btodb(fs->fs_bsize);
 488         /*
 489          * Get buffer of block pointers, zero those entries corresponding
 490          * to blocks to be free'd, and update on disk copy first.  Since
 491          * double(triple) indirect before single(double) indirect, calls
 492          * to bmap on these blocks will fail.  However, we already have
 493          * the on disk address, so we have to set the bio_offset field
 494          * explicitly instead of letting bread do everything for us.
 495          */
 496         vp = ITOV(ip);
 497         bp = getblk(vp, lblktodoff(fs, lbn), (int)fs->fs_bsize, 0, 0);
 498         if ((bp->b_flags & B_CACHE) == 0) {
 499                 bp->b_flags &= ~(B_ERROR|B_INVAL);
 500                 bp->b_cmd = BUF_CMD_READ;
 501                 if (bp->b_bcount > bp->b_bufsize)
 502                         panic("ffs_indirtrunc: bad buffer size");
 503                 /*
 504                  * BIO is bio2 which chains back to bio1.  We wait
 505                  * on bio1.
 506                  */
 507                 bp->b_bio2.bio_offset = dbtodoff(fs, dbn);
 508                 bp->b_bio1.bio_done = biodone_sync;
 509                 bp->b_bio1.bio_flags |= BIO_SYNC;
 510                 vfs_busy_pages(vp, bp);
 511                 /*
 512                  * Access the block device layer using the device vnode
 513                  * and the translated block number (bio2) instead of the
 514                  * file vnode (vp) and logical block number (bio1).
 515                  *
 516                  * Even though we are bypassing the vnode layer, we still
 517                  * want the vnode state to indicate that an I/O on its behalf
 518                  * is in progress.
 519                  */
 520                 bio_start_transaction(&bp->b_bio1, &vp->v_track_read);
 521                 vn_strategy(ip->i_devvp, &bp->b_bio2);
 522                 error = biowait(&bp->b_bio1, "biord");
 523         }
 524         if (error) {
 525                 brelse(bp);
 526                 *countp = 0;
 527                 return (error);
 528         }
 529
 530         bap = (ufs_daddr_t *)bp->b_data;
 531         if (lastbn != -1) {
 532                 copy = kmalloc(fs->fs_bsize, M_TEMP, M_WAITOK);
 533                 bcopy((caddr_t)bap, (caddr_t)copy, (uint)fs->fs_bsize);
 534                 bzero((caddr_t)&bap[last + 1],
 535                     (uint)(NINDIR(fs) - (last + 1)) * sizeof (ufs_daddr_t));
 536                 if (DOINGASYNC(vp)) {
 537                         bawrite(bp);
 538                 } else {
 539                         error = bwrite(bp);
 540                         if (error)
 541                                 allerror = error;
 542                 }
 543                 bap = copy;
 544         }
 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                 nb = bap[i];
 552                 if (nb == 0)
 553                         continue;
 554                 if (level > SINGLE) {
 555                         if ((error = ffs_indirtrunc(ip, nlbn, fsbtodb(fs, nb),
 556                             (ufs_daddr_t)-1, level - 1, &blkcount)) != 0)
 557                                 allerror = error;
 558                         blocksreleased += blkcount;
 559                 }
 560                 ffs_blkfree(ip, nb, fs->fs_bsize);
 561                 blocksreleased += nblocks;
 562         }
 563
 564         /*
 565          * Recursively free last partial block.
 566          */
 567         if (level > SINGLE && lastbn >= 0) {
 568                 last = lastbn % factor;
 569                 nb = bap[i];
 570                 if (nb != 0) {
 571                         error = ffs_indirtrunc(ip, nlbn, fsbtodb(fs, nb),
 572                             last, level - 1, &blkcount);
 573                         if (error)
 574                                 allerror = error;
 575                         blocksreleased += blkcount;
 576                 }
 577         }
 578         if (copy != NULL) {
 579                 kfree(copy, M_TEMP);
 580         } else {
 581                 bp->b_flags |= B_INVAL | B_NOCACHE;
 582                 brelse(bp);
 583         }
 584
 585         *countp = blocksreleased;
 586         return (allerror);
 587 }