Beispiel #1
0
/*
 * Truncate the inode oip to at most length size, freeing the
 * disk blocks.
 */
int
ffs_truncate(struct vnode *ovp, off_t length, int ioflag, kauth_cred_t cred)
{
    daddr_t lastblock;
    struct inode *oip = VTOI(ovp);
    daddr_t bn, lastiblock[UFS_NIADDR], indir_lbn[UFS_NIADDR];
    daddr_t blks[UFS_NDADDR + UFS_NIADDR];
    struct fs *fs;
    int offset, pgoffset, level;
    int64_t count, blocksreleased = 0;
    int i, aflag, nblocks;
    int error, allerror = 0;
    off_t osize;
    int sync;
    struct ufsmount *ump = oip->i_ump;

    if (ovp->v_type == VCHR || ovp->v_type == VBLK ||
            ovp->v_type == VFIFO || ovp->v_type == VSOCK) {
        KASSERT(oip->i_size == 0);
        return 0;
    }

    if (length < 0)
        return (EINVAL);

    if (ovp->v_type == VLNK &&
            (oip->i_size < ump->um_maxsymlinklen ||
             (ump->um_maxsymlinklen == 0 && DIP(oip, blocks) == 0))) {
        KDASSERT(length == 0);
        memset(SHORTLINK(oip), 0, (size_t)oip->i_size);
        oip->i_size = 0;
        DIP_ASSIGN(oip, size, 0);
        oip->i_flag |= IN_CHANGE | IN_UPDATE;
        return (ffs_update(ovp, NULL, NULL, 0));
    }
    if (oip->i_size == length) {
        /* still do a uvm_vnp_setsize() as writesize may be larger */
        uvm_vnp_setsize(ovp, length);
        oip->i_flag |= IN_CHANGE | IN_UPDATE;
        return (ffs_update(ovp, NULL, NULL, 0));
    }
    fs = oip->i_fs;
    if (length > ump->um_maxfilesize)
        return (EFBIG);

    if ((oip->i_flags & SF_SNAPSHOT) != 0)
        ffs_snapremove(ovp);

    osize = oip->i_size;
    aflag = ioflag & IO_SYNC ? B_SYNC : 0;

    /*
     * Lengthen the size of the file. We must ensure that the
     * last byte of the file is allocated. Since the smallest
     * value of osize is 0, length will be at least 1.
     */

    if (osize < length) {
        if (ffs_lblkno(fs, osize) < UFS_NDADDR &&
                ffs_lblkno(fs, osize) != ffs_lblkno(fs, length) &&
                ffs_blkroundup(fs, osize) != osize) {
            off_t eob;

            eob = ffs_blkroundup(fs, osize);
            uvm_vnp_setwritesize(ovp, eob);
            error = ufs_balloc_range(ovp, osize, eob - osize,
                                     cred, aflag);
            if (error) {
                (void) ffs_truncate(ovp, osize,
                                    ioflag & IO_SYNC, cred);
                return error;
            }
            if (ioflag & IO_SYNC) {
                mutex_enter(ovp->v_interlock);
                VOP_PUTPAGES(ovp,
                             trunc_page(osize & fs->fs_bmask),
                             round_page(eob), PGO_CLEANIT | PGO_SYNCIO |
                             PGO_JOURNALLOCKED);
            }
        }
        uvm_vnp_setwritesize(ovp, length);
        error = ufs_balloc_range(ovp, length - 1, 1, cred, aflag);
        if (error) {
            (void) ffs_truncate(ovp, osize, ioflag & IO_SYNC, cred);
            return (error);
        }
        uvm_vnp_setsize(ovp, length);
        oip->i_flag |= IN_CHANGE | IN_UPDATE;
        KASSERT(ovp->v_size == oip->i_size);
        return (ffs_update(ovp, NULL, NULL, 0));
    }

    /*
     * When truncating a regular file down to a non-block-aligned size,
     * we must zero the part of last block which is past the new EOF.
     * We must synchronously flush the zeroed pages to disk
     * since the new pages will be invalidated as soon as we
     * inform the VM system of the new, smaller size.
     * We must do this before acquiring the GLOCK, since fetching
     * the pages will acquire the GLOCK internally.
     * So there is a window where another thread could see a whole
     * zeroed page past EOF, but that's life.
     */

    offset = ffs_blkoff(fs, length);
    pgoffset = length & PAGE_MASK;
    if (ovp->v_type == VREG && (pgoffset != 0 || offset != 0) &&
            osize > length) {
        daddr_t lbn;
        voff_t eoz;
        int size;

        if (offset != 0) {
            error = ufs_balloc_range(ovp, length - 1, 1, cred,
                                     aflag);
            if (error)
                return error;
        }
        lbn = ffs_lblkno(fs, length);
        size = ffs_blksize(fs, oip, lbn);
        eoz = MIN(MAX(ffs_lblktosize(fs, lbn) + size, round_page(pgoffset)),
                  osize);
        ubc_zerorange(&ovp->v_uobj, length, eoz - length,
                      UBC_UNMAP_FLAG(ovp));
        if (round_page(eoz) > round_page(length)) {
            mutex_enter(ovp->v_interlock);
            error = VOP_PUTPAGES(ovp, round_page(length),
                                 round_page(eoz),
                                 PGO_CLEANIT | PGO_DEACTIVATE | PGO_JOURNALLOCKED |
                                 ((ioflag & IO_SYNC) ? PGO_SYNCIO : 0));
            if (error)
                return error;
        }
    }

    genfs_node_wrlock(ovp);
    oip->i_size = length;
    DIP_ASSIGN(oip, size, length);
    uvm_vnp_setsize(ovp, length);
    /*
     * Calculate index into inode's block list of
     * last direct and indirect blocks (if any)
     * which we want to keep.  Lastblock is -1 when
     * the file is truncated to 0.
     */
    lastblock = ffs_lblkno(fs, length + fs->fs_bsize - 1) - 1;
    lastiblock[SINGLE] = lastblock - UFS_NDADDR;
    lastiblock[DOUBLE] = lastiblock[SINGLE] - FFS_NINDIR(fs);
    lastiblock[TRIPLE] = lastiblock[DOUBLE] - FFS_NINDIR(fs) * FFS_NINDIR(fs);
    nblocks = btodb(fs->fs_bsize);
    /*
     * Update file and block pointers on disk before we start freeing
     * blocks.  If we crash before free'ing blocks below, the blocks
     * will be returned to the free list.  lastiblock values are also
     * normalized to -1 for calls to ffs_indirtrunc below.
     */
    sync = 0;
    for (level = TRIPLE; level >= SINGLE; level--) {
        blks[UFS_NDADDR + level] = DIP(oip, ib[level]);
        if (lastiblock[level] < 0 && blks[UFS_NDADDR + level] != 0) {
            sync = 1;
            DIP_ASSIGN(oip, ib[level], 0);
            lastiblock[level] = -1;
        }
    }
    for (i = 0; i < UFS_NDADDR; i++) {
        blks[i] = DIP(oip, db[i]);
        if (i > lastblock && blks[i] != 0) {
            sync = 1;
            DIP_ASSIGN(oip, db[i], 0);
        }
    }
    oip->i_flag |= IN_CHANGE | IN_UPDATE;
    if (sync) {
        error = ffs_update(ovp, NULL, NULL, UPDATE_WAIT);
        if (error && !allerror)
            allerror = error;
    }

    /*
     * Having written the new inode to disk, save its new configuration
     * and put back the old block pointers long enough to process them.
     * Note that we save the new block configuration so we can check it
     * when we are done.
     */
    for (i = 0; i < UFS_NDADDR; i++) {
        bn = DIP(oip, db[i]);
        DIP_ASSIGN(oip, db[i], blks[i]);
        blks[i] = bn;
    }
    for (i = 0; i < UFS_NIADDR; i++) {
        bn = DIP(oip, ib[i]);
        DIP_ASSIGN(oip, ib[i], blks[UFS_NDADDR + i]);
        blks[UFS_NDADDR + i] = bn;
    }

    oip->i_size = osize;
    DIP_ASSIGN(oip, size, osize);
    error = vtruncbuf(ovp, lastblock + 1, 0, 0);
    if (error && !allerror)
        allerror = error;

    /*
     * Indirect blocks first.
     */
    indir_lbn[SINGLE] = -UFS_NDADDR;
    indir_lbn[DOUBLE] = indir_lbn[SINGLE] - FFS_NINDIR(fs) - 1;
    indir_lbn[TRIPLE] = indir_lbn[DOUBLE] - FFS_NINDIR(fs) * FFS_NINDIR(fs) - 1;
    for (level = TRIPLE; level >= SINGLE; level--) {
        if (oip->i_ump->um_fstype == UFS1)
            bn = ufs_rw32(oip->i_ffs1_ib[level],UFS_FSNEEDSWAP(fs));
        else
            bn = ufs_rw64(oip->i_ffs2_ib[level],UFS_FSNEEDSWAP(fs));
        if (bn != 0) {
            error = ffs_indirtrunc(oip, indir_lbn[level],
                                   FFS_FSBTODB(fs, bn), lastiblock[level], level, &count);
            if (error)
                allerror = error;
            blocksreleased += count;
            if (lastiblock[level] < 0) {
                DIP_ASSIGN(oip, ib[level], 0);
                if (oip->i_ump->um_mountp->mnt_wapbl) {
                    UFS_WAPBL_REGISTER_DEALLOCATION(
                        oip->i_ump->um_mountp,
                        FFS_FSBTODB(fs, bn), fs->fs_bsize);
                } else
                    ffs_blkfree(fs, oip->i_devvp, bn,
                                fs->fs_bsize, oip->i_number);
                blocksreleased += nblocks;
            }
        }
        if (lastiblock[level] >= 0)
            goto done;
    }

    /*
     * All whole direct blocks or frags.
     */
    for (i = UFS_NDADDR - 1; i > lastblock; i--) {
        long bsize;

        if (oip->i_ump->um_fstype == UFS1)
            bn = ufs_rw32(oip->i_ffs1_db[i], UFS_FSNEEDSWAP(fs));
        else
            bn = ufs_rw64(oip->i_ffs2_db[i], UFS_FSNEEDSWAP(fs));
        if (bn == 0)
            continue;
        DIP_ASSIGN(oip, db[i], 0);
        bsize = ffs_blksize(fs, oip, i);
        if ((oip->i_ump->um_mountp->mnt_wapbl) &&
                (ovp->v_type != VREG)) {
            UFS_WAPBL_REGISTER_DEALLOCATION(oip->i_ump->um_mountp,
                                            FFS_FSBTODB(fs, bn), bsize);
        } else
            ffs_blkfree(fs, oip->i_devvp, bn, bsize, oip->i_number);
        blocksreleased += btodb(bsize);
    }
    if (lastblock < 0)
        goto done;

    /*
     * Finally, look for a change in size of the
     * last direct block; release any frags.
     */
    if (oip->i_ump->um_fstype == UFS1)
        bn = ufs_rw32(oip->i_ffs1_db[lastblock], UFS_FSNEEDSWAP(fs));
    else
        bn = ufs_rw64(oip->i_ffs2_db[lastblock], UFS_FSNEEDSWAP(fs));
    if (bn != 0) {
        long oldspace, newspace;

        /*
         * Calculate amount of space we're giving
         * back as old block size minus new block size.
         */
        oldspace = ffs_blksize(fs, oip, lastblock);
        oip->i_size = length;
        DIP_ASSIGN(oip, size, length);
        newspace = ffs_blksize(fs, oip, lastblock);
        if (newspace == 0)
            panic("itrunc: newspace");
        if (oldspace - newspace > 0) {
            /*
             * Block number of space to be free'd is
             * the old block # plus the number of frags
             * required for the storage we're keeping.
             */
            bn += ffs_numfrags(fs, newspace);
            if ((oip->i_ump->um_mountp->mnt_wapbl) &&
                    (ovp->v_type != VREG)) {
                UFS_WAPBL_REGISTER_DEALLOCATION(
                    oip->i_ump->um_mountp, FFS_FSBTODB(fs, bn),
                    oldspace - newspace);
            } else
                ffs_blkfree(fs, oip->i_devvp, bn,
                            oldspace - newspace, oip->i_number);
            blocksreleased += btodb(oldspace - newspace);
        }
    }

done:
#ifdef DIAGNOSTIC
    for (level = SINGLE; level <= TRIPLE; level++)
        if (blks[UFS_NDADDR + level] != DIP(oip, ib[level]))
            panic("itrunc1");
    for (i = 0; i < UFS_NDADDR; i++)
        if (blks[i] != DIP(oip, db[i]))
            panic("itrunc2");
    if (length == 0 &&
            (!LIST_EMPTY(&ovp->v_cleanblkhd) || !LIST_EMPTY(&ovp->v_dirtyblkhd)))
        panic("itrunc3");
#endif /* DIAGNOSTIC */
    /*
     * Put back the real size.
     */
    oip->i_size = length;
    DIP_ASSIGN(oip, size, length);
    DIP_ADD(oip, blocks, -blocksreleased);
    genfs_node_unlock(ovp);
    oip->i_flag |= IN_CHANGE;
    UFS_WAPBL_UPDATE(ovp, NULL, NULL, 0);
#if defined(QUOTA) || defined(QUOTA2)
    (void) chkdq(oip, -blocksreleased, NOCRED, 0);
#endif
    KASSERT(ovp->v_type != VREG || ovp->v_size == oip->i_size);
    return (allerror);
}
Beispiel #2
0
int
lfs_truncate(struct vnode *ovp, off_t length, int ioflag, kauth_cred_t cred)
{
	daddr_t lastblock;
	struct inode *oip = VTOI(ovp);
	daddr_t bn, lbn, lastiblock[ULFS_NIADDR], indir_lbn[ULFS_NIADDR];
	/* XXX ondisk32 */
	int32_t newblks[ULFS_NDADDR + ULFS_NIADDR];
	struct lfs *fs;
	struct buf *bp;
	int offset, size, level;
	daddr_t count, rcount;
	daddr_t blocksreleased = 0, real_released = 0;
	int i, nblocks;
	int aflags, error, allerror = 0;
	off_t osize;
	long lastseg;
	size_t bc;
	int obufsize, odb;
	int usepc;

	if (ovp->v_type == VCHR || ovp->v_type == VBLK ||
	    ovp->v_type == VFIFO || ovp->v_type == VSOCK) {
		KASSERT(oip->i_size == 0);
		return 0;
	}

	if (length < 0)
		return (EINVAL);

	/*
	 * Just return and not update modification times.
	 */
	if (oip->i_size == length) {
		/* still do a uvm_vnp_setsize() as writesize may be larger */
		uvm_vnp_setsize(ovp, length);
		return (0);
	}

	fs = oip->i_lfs;

	if (ovp->v_type == VLNK &&
	    (oip->i_size < fs->um_maxsymlinklen ||
	     (fs->um_maxsymlinklen == 0 &&
	      oip->i_ffs1_blocks == 0))) {
#ifdef DIAGNOSTIC
		if (length != 0)
			panic("lfs_truncate: partial truncate of symlink");
#endif
		memset((char *)SHORTLINK(oip), 0, (u_int)oip->i_size);
		oip->i_size = oip->i_ffs1_size = 0;
		oip->i_flag |= IN_CHANGE | IN_UPDATE;
		return (lfs_update(ovp, NULL, NULL, 0));
	}
	if (oip->i_size == length) {
		oip->i_flag |= IN_CHANGE | IN_UPDATE;
		return (lfs_update(ovp, NULL, NULL, 0));
	}
	lfs_imtime(fs);
	osize = oip->i_size;
	usepc = (ovp->v_type == VREG && ovp != fs->lfs_ivnode);

	ASSERT_NO_SEGLOCK(fs);
	/*
	 * Lengthen the size of the file. We must ensure that the
	 * last byte of the file is allocated. Since the smallest
	 * value of osize is 0, length will be at least 1.
	 */
	if (osize < length) {
		if (length > fs->um_maxfilesize)
			return (EFBIG);
		aflags = B_CLRBUF;
		if (ioflag & IO_SYNC)
			aflags |= B_SYNC;
		if (usepc) {
			if (lfs_lblkno(fs, osize) < ULFS_NDADDR &&
			    lfs_lblkno(fs, osize) != lfs_lblkno(fs, length) &&
			    lfs_blkroundup(fs, osize) != osize) {
				off_t eob;

				eob = lfs_blkroundup(fs, osize);
				uvm_vnp_setwritesize(ovp, eob);
				error = ulfs_balloc_range(ovp, osize,
				    eob - osize, cred, aflags);
				if (error) {
					(void) lfs_truncate(ovp, osize,
						    ioflag & IO_SYNC, cred);
					return error;
				}
				if (ioflag & IO_SYNC) {
					mutex_enter(ovp->v_interlock);
					VOP_PUTPAGES(ovp,
					    trunc_page(osize & lfs_sb_getbmask(fs)),
					    round_page(eob),
					    PGO_CLEANIT | PGO_SYNCIO);
				}
			}
			uvm_vnp_setwritesize(ovp, length);
			error = ulfs_balloc_range(ovp, length - 1, 1, cred,
						 aflags);
			if (error) {
				(void) lfs_truncate(ovp, osize,
						    ioflag & IO_SYNC, cred);
				return error;
			}
			uvm_vnp_setsize(ovp, length);
			oip->i_flag |= IN_CHANGE | IN_UPDATE;
			KASSERT(ovp->v_size == oip->i_size);
			oip->i_lfs_hiblk = lfs_lblkno(fs, oip->i_size + lfs_sb_getbsize(fs) - 1) - 1;
			return (lfs_update(ovp, NULL, NULL, 0));
		} else {
			error = lfs_reserve(fs, ovp, NULL,
			    lfs_btofsb(fs, (ULFS_NIADDR + 2) << lfs_sb_getbshift(fs)));
			if (error)
				return (error);
			error = lfs_balloc(ovp, length - 1, 1, cred,
					   aflags, &bp);
			lfs_reserve(fs, ovp, NULL,
			    -lfs_btofsb(fs, (ULFS_NIADDR + 2) << lfs_sb_getbshift(fs)));
			if (error)
				return (error);
			oip->i_ffs1_size = oip->i_size = length;
			uvm_vnp_setsize(ovp, length);
			(void) VOP_BWRITE(bp->b_vp, bp);
			oip->i_flag |= IN_CHANGE | IN_UPDATE;
			oip->i_lfs_hiblk = lfs_lblkno(fs, oip->i_size + lfs_sb_getbsize(fs) - 1) - 1;
			return (lfs_update(ovp, NULL, NULL, 0));
		}
	}

	if ((error = lfs_reserve(fs, ovp, NULL,
	    lfs_btofsb(fs, (2 * ULFS_NIADDR + 3) << lfs_sb_getbshift(fs)))) != 0)
		return (error);

	/*
	 * Shorten the size of the file. If the file is not being
	 * truncated to a block boundary, the contents of the
	 * partial block following the end of the file must be
	 * zero'ed in case it ever becomes accessible again because
	 * of subsequent file growth. Directories however are not
	 * zero'ed as they should grow back initialized to empty.
	 */
	offset = lfs_blkoff(fs, length);
	lastseg = -1;
	bc = 0;

	if (ovp != fs->lfs_ivnode)
		lfs_seglock(fs, SEGM_PROT);
	if (offset == 0) {
		oip->i_size = oip->i_ffs1_size = length;
	} else if (!usepc) {
		lbn = lfs_lblkno(fs, length);
		aflags = B_CLRBUF;
		if (ioflag & IO_SYNC)
			aflags |= B_SYNC;
		error = lfs_balloc(ovp, length - 1, 1, cred, aflags, &bp);
		if (error) {
			lfs_reserve(fs, ovp, NULL,
			    -lfs_btofsb(fs, (2 * ULFS_NIADDR + 3) << lfs_sb_getbshift(fs)));
			goto errout;
		}
		obufsize = bp->b_bufsize;
		odb = lfs_btofsb(fs, bp->b_bcount);
		oip->i_size = oip->i_ffs1_size = length;
		size = lfs_blksize(fs, oip, lbn);
		if (ovp->v_type != VDIR)
			memset((char *)bp->b_data + offset, 0,
			       (u_int)(size - offset));
		allocbuf(bp, size, 1);
		if ((bp->b_flags & B_LOCKED) != 0 && bp->b_iodone == NULL) {
			mutex_enter(&lfs_lock);
			locked_queue_bytes -= obufsize - bp->b_bufsize;
			mutex_exit(&lfs_lock);
		}
		if (bp->b_oflags & BO_DELWRI) {
			lfs_sb_addavail(fs, odb - lfs_btofsb(fs, size));
			/* XXX shouldn't this wake up on lfs_availsleep? */
		}
		(void) VOP_BWRITE(bp->b_vp, bp);
	} else { /* vp->v_type == VREG && length < osize && offset != 0 */
		/*
		 * When truncating a regular file down to a non-block-aligned
		 * size, we must zero the part of last block which is past
		 * the new EOF.  We must synchronously flush the zeroed pages
		 * to disk since the new pages will be invalidated as soon
		 * as we inform the VM system of the new, smaller size.
		 * We must do this before acquiring the GLOCK, since fetching
		 * the pages will acquire the GLOCK internally.
		 * So there is a window where another thread could see a whole
		 * zeroed page past EOF, but that's life.
		 */
		daddr_t xlbn;
		voff_t eoz;

		aflags = ioflag & IO_SYNC ? B_SYNC : 0;
		error = ulfs_balloc_range(ovp, length - 1, 1, cred, aflags);
		if (error) {
			lfs_reserve(fs, ovp, NULL,
				    -lfs_btofsb(fs, (2 * ULFS_NIADDR + 3) << lfs_sb_getbshift(fs)));
			goto errout;
		}
		xlbn = lfs_lblkno(fs, length);
		size = lfs_blksize(fs, oip, xlbn);
		eoz = MIN(lfs_lblktosize(fs, xlbn) + size, osize);
		ubc_zerorange(&ovp->v_uobj, length, eoz - length,
		    UBC_UNMAP_FLAG(ovp));
		if (round_page(eoz) > round_page(length)) {
			mutex_enter(ovp->v_interlock);
			error = VOP_PUTPAGES(ovp, round_page(length),
			    round_page(eoz),
			    PGO_CLEANIT | PGO_DEACTIVATE |
			    ((ioflag & IO_SYNC) ? PGO_SYNCIO : 0));
			if (error) {
				lfs_reserve(fs, ovp, NULL,
					    -lfs_btofsb(fs, (2 * ULFS_NIADDR + 3) << lfs_sb_getbshift(fs)));
				goto errout;
			}
		}
	}

	genfs_node_wrlock(ovp);

	oip->i_size = oip->i_ffs1_size = length;
	uvm_vnp_setsize(ovp, length);

	/*
	 * Calculate index into inode's block list of
	 * last direct and indirect blocks (if any)
	 * which we want to keep.  Lastblock is -1 when
	 * the file is truncated to 0.
	 */
	/* Avoid sign overflow - XXX assumes that off_t is a quad_t. */
	if (length > QUAD_MAX - lfs_sb_getbsize(fs))
		lastblock = lfs_lblkno(fs, QUAD_MAX - lfs_sb_getbsize(fs));
	else
		lastblock = lfs_lblkno(fs, length + lfs_sb_getbsize(fs) - 1) - 1;
	lastiblock[SINGLE] = lastblock - ULFS_NDADDR;
	lastiblock[DOUBLE] = lastiblock[SINGLE] - LFS_NINDIR(fs);
	lastiblock[TRIPLE] = lastiblock[DOUBLE] - LFS_NINDIR(fs) * LFS_NINDIR(fs);
	nblocks = lfs_btofsb(fs, lfs_sb_getbsize(fs));
	/*
	 * Record changed file and block pointers before we start
	 * freeing blocks.  lastiblock values are also normalized to -1
	 * for calls to lfs_indirtrunc below.
	 */
	memcpy((void *)newblks, (void *)&oip->i_ffs1_db[0], sizeof newblks);
	for (level = TRIPLE; level >= SINGLE; level--)
		if (lastiblock[level] < 0) {
			newblks[ULFS_NDADDR+level] = 0;
			lastiblock[level] = -1;
		}
	for (i = ULFS_NDADDR - 1; i > lastblock; i--)
		newblks[i] = 0;

	oip->i_size = oip->i_ffs1_size = osize;
	error = lfs_vtruncbuf(ovp, lastblock + 1, false, 0);
	if (error && !allerror)
		allerror = error;

	/*
	 * Indirect blocks first.
	 */
	indir_lbn[SINGLE] = -ULFS_NDADDR;
	indir_lbn[DOUBLE] = indir_lbn[SINGLE] - LFS_NINDIR(fs) - 1;
	indir_lbn[TRIPLE] = indir_lbn[DOUBLE] - LFS_NINDIR(fs) * LFS_NINDIR(fs) - 1;
	for (level = TRIPLE; level >= SINGLE; level--) {
		bn = oip->i_ffs1_ib[level];
		if (bn != 0) {
			error = lfs_indirtrunc(oip, indir_lbn[level],
					       bn, lastiblock[level],
					       level, &count, &rcount,
					       &lastseg, &bc);
			if (error)
				allerror = error;
			real_released += rcount;
			blocksreleased += count;
			if (lastiblock[level] < 0) {
				if (oip->i_ffs1_ib[level] > 0)
					real_released += nblocks;
				blocksreleased += nblocks;
				oip->i_ffs1_ib[level] = 0;
				lfs_blkfree(fs, oip, bn, lfs_sb_getbsize(fs),
					    &lastseg, &bc);
        			lfs_deregister_block(ovp, bn);
			}
		}
		if (lastiblock[level] >= 0)
			goto done;
	}

	/*
	 * All whole direct blocks or frags.
	 */
	for (i = ULFS_NDADDR - 1; i > lastblock; i--) {
		long bsize, obsize;

		bn = oip->i_ffs1_db[i];
		if (bn == 0)
			continue;
		bsize = lfs_blksize(fs, oip, i);
		if (oip->i_ffs1_db[i] > 0) {
			/* Check for fragment size changes */
			obsize = oip->i_lfs_fragsize[i];
			real_released += lfs_btofsb(fs, obsize);
			oip->i_lfs_fragsize[i] = 0;
		} else
			obsize = 0;
		blocksreleased += lfs_btofsb(fs, bsize);
		oip->i_ffs1_db[i] = 0;
		lfs_blkfree(fs, oip, bn, obsize, &lastseg, &bc);
        	lfs_deregister_block(ovp, bn);
	}
	if (lastblock < 0)
		goto done;

	/*
	 * Finally, look for a change in size of the
	 * last direct block; release any frags.
	 */
	bn = oip->i_ffs1_db[lastblock];
	if (bn != 0) {
		long oldspace, newspace;
#if 0
		long olddspace;
#endif

		/*
		 * Calculate amount of space we're giving
		 * back as old block size minus new block size.
		 */
		oldspace = lfs_blksize(fs, oip, lastblock);
#if 0
		olddspace = oip->i_lfs_fragsize[lastblock];
#endif

		oip->i_size = oip->i_ffs1_size = length;
		newspace = lfs_blksize(fs, oip, lastblock);
		if (newspace == 0)
			panic("itrunc: newspace");
		if (oldspace - newspace > 0) {
			blocksreleased += lfs_btofsb(fs, oldspace - newspace);
		}
#if 0
		if (bn > 0 && olddspace - newspace > 0) {
			/* No segment accounting here, just vnode */
			real_released += lfs_btofsb(fs, olddspace - newspace);
		}
#endif
	}

done:
	/* Finish segment accounting corrections */
	lfs_update_seguse(fs, oip, lastseg, bc);
#ifdef DIAGNOSTIC
	for (level = SINGLE; level <= TRIPLE; level++)
		if ((newblks[ULFS_NDADDR + level] == 0) !=
		    ((oip->i_ffs1_ib[level]) == 0)) {
			panic("lfs itrunc1");
		}
	for (i = 0; i < ULFS_NDADDR; i++)
		if ((newblks[i] == 0) != (oip->i_ffs1_db[i] == 0)) {
			panic("lfs itrunc2");
		}
	if (length == 0 &&
	    (!LIST_EMPTY(&ovp->v_cleanblkhd) || !LIST_EMPTY(&ovp->v_dirtyblkhd)))
		panic("lfs itrunc3");
#endif /* DIAGNOSTIC */
	/*
	 * Put back the real size.
	 */
	oip->i_size = oip->i_ffs1_size = length;
	oip->i_lfs_effnblks -= blocksreleased;
	oip->i_ffs1_blocks -= real_released;
	mutex_enter(&lfs_lock);
	lfs_sb_addbfree(fs, blocksreleased);
	mutex_exit(&lfs_lock);
#ifdef DIAGNOSTIC
	if (oip->i_size == 0 &&
	    (oip->i_ffs1_blocks != 0 || oip->i_lfs_effnblks != 0)) {
		printf("lfs_truncate: truncate to 0 but %d blks/%jd effblks\n",
		       oip->i_ffs1_blocks, (intmax_t)oip->i_lfs_effnblks);
		panic("lfs_truncate: persistent blocks");
	}
#endif

	/*
	 * If we truncated to zero, take us off the paging queue.
	 */
	mutex_enter(&lfs_lock);
	if (oip->i_size == 0 && oip->i_flags & IN_PAGING) {
		oip->i_flags &= ~IN_PAGING;
		TAILQ_REMOVE(&fs->lfs_pchainhd, oip, i_lfs_pchain);
	}
	mutex_exit(&lfs_lock);

	oip->i_flag |= IN_CHANGE;
#if defined(LFS_QUOTA) || defined(LFS_QUOTA2)
	(void) lfs_chkdq(oip, -blocksreleased, NOCRED, 0);
#endif
	lfs_reserve(fs, ovp, NULL,
	    -lfs_btofsb(fs, (2 * ULFS_NIADDR + 3) << lfs_sb_getbshift(fs)));
	genfs_node_unlock(ovp);
  errout:
	oip->i_lfs_hiblk = lfs_lblkno(fs, oip->i_size + lfs_sb_getbsize(fs) - 1) - 1;
	if (ovp != fs->lfs_ivnode)
		lfs_segunlock(fs);
	return (allerror ? allerror : error);
}