/*      $NetBSD: lfs_inode.c,v 1.165 2026/01/05 05:02:47 perseant Exp $ */

/*-
 * Copyright (c) 1999, 2000, 2001, 2002, 2003 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Konrad E. Schroder <perseant@hhhh.org>.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */
/*
 * Copyright (c) 1986, 1989, 1991, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      @(#)lfs_inode.c 8.9 (Berkeley) 5/8/95
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: lfs_inode.c,v 1.165 2026/01/05 05:02:47 perseant Exp $");

#if defined(_KERNEL_OPT)
#include "opt_quota.h"
#endif

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mount.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <sys/file.h>
#include <sys/buf.h>
#include <sys/vnode.h>
#include <sys/kernel.h>
#include <sys/trace.h>
#include <sys/resourcevar.h>
#include <sys/kauth.h>

#include <ufs/lfs/ulfs_quotacommon.h>
#include <ufs/lfs/ulfs_inode.h>
#include <ufs/lfs/ulfsmount.h>
#include <ufs/lfs/ulfs_extern.h>

#include <ufs/lfs/lfs.h>
#include <ufs/lfs/lfs_accessors.h>
#include <ufs/lfs/lfs_extern.h>
#include <ufs/lfs/lfs_kernel.h>

static int lfs_update_seguse(struct lfs *, struct inode *ip, long, size_t);
static int lfs_indirtrunc(struct inode *, daddr_t, daddr_t,
                          daddr_t, int, daddr_t *, daddr_t *,
                          long *, size_t *);
static int lfs_blkfree (struct lfs *, struct inode *, daddr_t, size_t, long *, size_t *);
static int lfs_vtruncbuf(struct vnode *, daddr_t, bool, int);

/* Search a block for a specific dinode. */
union lfs_dinode *
lfs_ifind(struct lfs *fs, ino_t ino, struct buf *bp)
{
        union lfs_dinode *ldip;
        unsigned num, i;

        ASSERT_NO_SEGLOCK(fs);
        /*
         * Read the inode block backwards, since later versions of the
         * inode will supercede earlier ones.  Though it is unlikely, it is
         * possible that the same inode will appear in the same inode block.
         */
        num = LFS_INOPB(fs);
        for (i = num; i-- > 0; ) {
                ldip = DINO_IN_BLOCK(fs, bp->b_data, i);
                if (lfs_dino_getinumber(fs, ldip) == ino)
                        return (ldip);
        }

        printf("searched %u entries for %ju\n", num, (uintmax_t)ino);
        printf("offset is 0x%jx (seg %d)\n", (uintmax_t)lfs_sb_getoffset(fs),
               lfs_dtosn(fs, lfs_sb_getoffset(fs)));
        printf("block is 0x%jx (seg %d)\n",
               (uintmax_t)LFS_DBTOFSB(fs, bp->b_blkno),
               lfs_dtosn(fs, LFS_DBTOFSB(fs, bp->b_blkno)));

        return NULL;
}

int
lfs_update(struct vnode *vp, const struct timespec *acc,
    const struct timespec *mod, int updflags)
{
        struct inode *ip;
        struct lfs *fs = VFSTOULFS(vp->v_mount)->um_lfs;
        int flags;
        int error;

        ASSERT_NO_SEGLOCK(fs);
        if (vp->v_mount->mnt_flag & MNT_RDONLY)
                return (0);
        ip = VTOI(vp);

        /*
         * If we are called from vinvalbuf, and the file's blocks have
         * already been scheduled for writing, but the writes have not
         * yet completed, lfs_vflush will not be called, and vinvalbuf
         * will cause a panic.  So, we must wait until any pending write
         * for our inode completes, if we are called with UPDATE_WAIT set.
         */
        mutex_enter(vp->v_interlock);
        while ((updflags & (UPDATE_WAIT|UPDATE_DIROP)) == UPDATE_WAIT &&
            WRITEINPROG(vp)) {
                DLOG((DLOG_SEG, "lfs_update: sleeping on ino %llu"
                      " (in progress)\n", (unsigned long long) ip->i_number));
                cv_wait(&vp->v_cv, vp->v_interlock);
        }
        mutex_exit(vp->v_interlock);
        LFS_ITIMES(ip, acc, mod, NULL);
        if (updflags & UPDATE_CLOSE)
                flags = ip->i_state & (IN_MODIFIED | IN_ACCESSED | IN_CLEANING);
        else
                flags = ip->i_state & (IN_MODIFIED | IN_CLEANING);
        if (flags == 0)
                return (0);

        /* If sync, push back the vnode and any dirty blocks it may have. */
        if ((updflags & (UPDATE_WAIT|UPDATE_DIROP)) == UPDATE_WAIT) {
                /* Avoid flushing VU_DIROP. */
                mutex_enter(&lfs_lock);
                ++fs->lfs_diropwait;
                while (vp->v_uflag & VU_DIROP) {
                        DLOG((DLOG_DIROP, "lfs_update: sleeping on inode %llu "
                              "(dirops)\n", (unsigned long long) ip->i_number));
                        DLOG((DLOG_DIROP, "lfs_update: vflags 0x%x, i_state"
                              " 0x%x\n",
                              vp->v_iflag | vp->v_vflag | vp->v_uflag,
                              ip->i_state));
                        if (fs->lfs_dirops == 0)
                                break;
                        else
                                mtsleep(&fs->lfs_writer, PRIBIO+1, "lfs_fsync",
                                        0, &lfs_lock);
                        /* XXX KS - by falling out here, are we writing the vn
                        twice? */
                }
                --fs->lfs_diropwait;
                fs->lfs_writer++;
                if (vp->v_uflag & VU_DIROP) {
                        KASSERT(fs->lfs_dirops == 0);
                        lfs_flush_fs(fs, SEGM_SYNC);
                }
                mutex_exit(&lfs_lock);
                error = lfs_vflush(vp);
                mutex_enter(&lfs_lock);
                if (--fs->lfs_writer == 0)
                        cv_broadcast(&fs->lfs_diropscv);
                mutex_exit(&lfs_lock);
                return error;
        }
        return 0;
}

#define SINGLE  0       /* index of single indirect block */
#define DOUBLE  1       /* index of double indirect block */
#define TRIPLE  2       /* index of triple indirect block */
/*
 * Truncate the inode oip to at most length size, freeing the
 * disk blocks.
 */
/* VOP_BWRITE 1 + ULFS_NIADDR + lfs_balloc == 2 + 2*ULFS_NIADDR times */

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];
        /* note: newblks is set but only actually used if DIAGNOSTIC */
        daddr_t newblks[ULFS_NDADDR + ULFS_NIADDR] __diagused;
        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);

        fs = oip->i_lfs;

        if (ovp->v_type == VLNK &&
            (oip->i_size < fs->um_maxsymlinklen ||
             (fs->um_maxsymlinklen == 0 &&
              lfs_dino_getblocks(fs, oip->i_din) == 0))) {
                KASSERTMSG((length == 0),
                    "partial truncate of symlink: %jd", (intmax_t)length);
                memset((char *)SHORTLINK(oip), 0, (u_int)oip->i_size);
                oip->i_size = 0;
                lfs_dino_setsize(fs, oip->i_din, 0);
                oip->i_state |= IN_CHANGE | IN_UPDATE;
                return (lfs_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_state |= 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) {
                                        rw_enter(ovp->v_uobj.vmobjlock, RW_WRITER);
                                        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_state |= 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_size = length;
                        lfs_dino_setsize(fs, oip->i_din, oip->i_size);
                        uvm_vnp_setsize(ovp, length);
                        (void) VOP_BWRITE(bp->b_vp, bp);
                        oip->i_state |= 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_prelock(fs, 0);
        if (offset == 0) {
                oip->i_size = length;
                lfs_dino_setsize(fs, oip->i_din, oip->i_size);
        } 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 = length;
                lfs_dino_setsize(fs, oip->i_din, oip->i_size);
                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_VNODE_FLAGS(ovp));
                if (round_page(eoz) > round_page(length)) {
                        rw_enter(ovp->v_uobj.vmobjlock, RW_WRITER);
                        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 = length;
        lfs_dino_setsize(fs, oip->i_din, oip->i_size);
        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.
         */
        for (i=0; i<ULFS_NDADDR; i++) {
                newblks[i] = lfs_dino_getdb(fs, oip->i_din, i);
        }
        for (i=0; i<ULFS_NIADDR; i++) {
                newblks[ULFS_NDADDR + i] = lfs_dino_getib(fs, oip->i_din, i);
        }
        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 = osize;
        lfs_dino_setsize(fs, oip->i_din, oip->i_size);
        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 = lfs_dino_getib(fs, oip->i_din, 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 (lfs_dino_getib(fs, oip->i_din, level) > 0)
                                        real_released += nblocks;
                                blocksreleased += nblocks;
                                lfs_dino_setib(fs, oip->i_din, 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 = lfs_dino_getdb(fs, oip->i_din, i);
                if (bn == 0)
                        continue;
                bsize = lfs_blksize(fs, oip, i);
                if (lfs_dino_getdb(fs, oip->i_din, 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);
                lfs_dino_setdb(fs, oip->i_din, 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 = lfs_dino_getdb(fs, oip->i_din, 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 = length;
                lfs_dino_setsize(fs, oip->i_din, oip->i_size);
                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);
        for (level = SINGLE; level <= TRIPLE; level++)
                KASSERTMSG(((newblks[ULFS_NDADDR + level] == 0) ==
                        (lfs_dino_getib(fs, oip->i_din, level) == 0)),
                    "lfs itrunc1");
        for (i = 0; i < ULFS_NDADDR; i++)
                KASSERTMSG(((newblks[i] == 0) ==
                        (lfs_dino_getdb(fs, oip->i_din, i) == 0)),
                    "lfs itrunc2");
        KASSERTMSG((length != 0 || LIST_EMPTY(&ovp->v_cleanblkhd)),
            "lfs itrunc3a");
        KASSERTMSG((length != 0 || LIST_EMPTY(&ovp->v_dirtyblkhd)),
            "lfs itrunc3b");

        /*
         * Put back the real size.
         */
        oip->i_size = length;
        lfs_dino_setsize(fs, oip->i_din, oip->i_size);
        oip->i_lfs_effnblks -= blocksreleased;

        mutex_enter(&lfs_lock);
        lfs_dino_setblocks(fs, oip->i_din,
            lfs_dino_getblocks(fs, oip->i_din) - real_released);
        lfs_sb_addbfree(fs, blocksreleased);

        KASSERTMSG((oip->i_size != 0 ||
                lfs_dino_getblocks(fs, oip->i_din) == 0),
            "ino %llu truncate to 0 but %jd blks/%jd effblks",
            (unsigned long long) oip->i_number,
            lfs_dino_getblocks(fs, oip->i_din), oip->i_lfs_effnblks);
        KASSERTMSG((oip->i_size != 0 || oip->i_lfs_effnblks == 0),
            "ino %llu truncate to 0 but %jd blks/%jd effblks",
            (unsigned long long) oip->i_number,
            lfs_dino_getblocks(fs, oip->i_din), oip->i_lfs_effnblks);

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

        oip->i_state |= 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_preunlock(fs);
        return (allerror ? allerror : error);
}

/* Update segment and avail usage information when removing a block. */
static int
lfs_blkfree(struct lfs *fs, struct inode *ip, daddr_t daddr,
            size_t bsize, long *lastseg, size_t *num)
{
        long seg;
        int error = 0;

        ASSERT_SEGLOCK(fs);
        bsize = lfs_fragroundup(fs, bsize);
        if (daddr > 0) {
                if (*lastseg != (seg = lfs_dtosn(fs, daddr))) {
                        error = lfs_update_seguse(fs, ip, *lastseg, *num);
                        *num = bsize;
                        *lastseg = seg;
                } else
                        *num += bsize;
        }

        return error;
}

/* Finish the accounting updates for a segment. */
static int
lfs_update_seguse(struct lfs *fs, struct inode *ip, long lastseg, size_t num)
{
        struct segdelta *sd;

        ASSERT_SEGLOCK(fs);
        if (lastseg < 0 || num == 0)
                return 0;

        sd = rb_tree_find_node(&ip->i_lfs_segdhd, &lastseg);
        if (sd == NULL) {
                sd = malloc(sizeof(*sd), M_SEGMENT, M_WAITOK);
                sd->segnum = lastseg;
                sd->num = 0;
                rb_tree_insert_node(&ip->i_lfs_segdhd, sd);
        }
        sd->num += num;
        DLOG((DLOG_SU, "seg %jd -= %jd for ino %jd (postponed)\n",
              (intmax_t)lastseg, (intmax_t)num,
              (intmax_t)ip->i_number));

        return 0;
}

static void
lfs_finalize_seguse(struct lfs *fs, void *v)
{
        SEGUSE *sup;
        struct buf *bp;
        struct segdelta *sd, *tmp;
        rb_tree_t *rbt = v;

        ASSERT_SEGLOCK(fs);
        RB_TREE_FOREACH_SAFE(sd, rbt, tmp) {
                LFS_SEGENTRY(sup, fs, sd->segnum, bp);
                DLOG((DLOG_SU, "seg %jd -= %jd when finalized\n",
                        (intmax_t)sd->segnum, (intmax_t)sd->num));
                if (sd->num > sup->su_nbytes) {
                        printf("lfs_finalize_seguse: seg %ld short by %ld\n",
                                sd->segnum, (long)(sd->num - sup->su_nbytes));
                        panic("lfs_finalize_seguse: negative bytes");
                        sup->su_nbytes = sd->num;
                }
                sup->su_nbytes -= sd->num;
                LFS_WRITESEGENTRY(sup, fs, sd->segnum, bp);
                rb_tree_remove_node(rbt, sd);
                free(sd, M_SEGMENT);
        }
}

/* Finish the accounting updates for a segment. */
void
lfs_finalize_ino_seguse(struct lfs *fs, struct inode *ip)
{
        ASSERT_SEGLOCK(fs);
        lfs_finalize_seguse(fs, &ip->i_lfs_segdhd);
}

/* Finish the accounting updates for a segment. */
void
lfs_finalize_fs_seguse(struct lfs *fs)
{
        ASSERT_SEGLOCK(fs);
        lfs_finalize_seguse(fs, &fs->lfs_segdhd);
}

/*
 * Release blocks associated with the inode ip and stored in the indirect
 * block bn.  Blocks are free'd in LIFO order up to (but not including)
 * lastbn.  If level is greater than SINGLE, the block is an indirect block
 * and recursive calls to indirtrunc must be used to cleanse other indirect
 * blocks.
 *
 * NB: triple indirect blocks are untested.
 */
static int
lfs_indirtrunc(struct inode *ip, daddr_t lbn, daddr_t dbn,
               daddr_t lastbn, int level, daddr_t *countp,
               daddr_t *rcountp, long *lastsegp, size_t *bcp)
{
        int i;
        struct buf *bp;
        struct lfs *fs = ip->i_lfs;
        void *bap;
        bool bap_needs_free;
        struct vnode *vp;
        daddr_t nb, nlbn, last;
        daddr_t blkcount, rblkcount, factor;
        int nblocks;
        daddr_t blocksreleased = 0, real_released = 0;
        int error = 0, allerror = 0;

        ASSERT_SEGLOCK(fs);
        /*
         * Calculate index in current block of last
         * block to be kept.  -1 indicates the entire
         * block so we need not calculate the index.
         */
        factor = 1;
        for (i = SINGLE; i < level; i++)
                factor *= LFS_NINDIR(fs);
        last = lastbn;
        if (lastbn > 0)
                last /= factor;
        nblocks = lfs_btofsb(fs, lfs_sb_getbsize(fs));
        /*
         * Get buffer of block pointers, zero those entries corresponding
         * to blocks to be free'd, and update on disk copy first.  Since
         * double(triple) indirect before single(double) indirect, calls
         * to bmap on these blocks will fail.  However, we already have
         * the on disk address, so we have to set the b_blkno field
         * explicitly instead of letting bread do everything for us.
         */
        vp = ITOV(ip);
        bp = getblk(vp, lbn, lfs_sb_getbsize(fs), 0, 0);
        if (bp->b_oflags & (BO_DONE | BO_DELWRI)) {
                /* Braces must be here in case trace evaluates to nothing. */
                trace(TR_BREADHIT, pack(vp, lfs_sb_getbsize(fs)), lbn);
        } else {
                trace(TR_BREADMISS, pack(vp, lfs_sb_getbsize(fs)), lbn);
                curlwp->l_ru.ru_inblock++; /* pay for read */
                bp->b_flags |= B_READ;
                if (bp->b_bcount > bp->b_bufsize)
                        panic("lfs_indirtrunc: bad buffer size");
                bp->b_blkno = LFS_FSBTODB(fs, dbn);
                VOP_STRATEGY(vp, bp);
                error = biowait(bp);
        }
        if (error) {
                brelse(bp, 0);
                *countp = *rcountp = 0;
                return (error);
        }

        if (lastbn >= 0) {
                /*
                 * We still need this block, so copy the data for
                 * subsequent processing; then in the original block,
                 * zero out the dying block pointers and send it off.
                 */
                bap = lfs_malloc(fs, lfs_sb_getbsize(fs), LFS_NB_IBLOCK);
                memcpy(bap, bp->b_data, lfs_sb_getbsize(fs));
                bap_needs_free = true;

                for (i = last + 1; i < LFS_NINDIR(fs); i++) {
                        lfs_iblock_set(fs, bp->b_data, i, 0);
                }
                error = VOP_BWRITE(bp->b_vp, bp);
                if (error)
                        allerror = error;
        } else {
                bap = bp->b_data;
                bap_needs_free = false;
        }

        /*
         * Recursively free totally unused blocks.
         */
        for (i = LFS_NINDIR(fs) - 1, nlbn = lbn + 1 - i * factor; i > last;
            i--, nlbn += factor) {
                nb = lfs_iblock_get(fs, bap, i);
                if (nb == 0)
                        continue;
                if (level > SINGLE) {
                        error = lfs_indirtrunc(ip, nlbn, nb,
                                               (daddr_t)-1, level - 1,
                                               &blkcount, &rblkcount,
                                               lastsegp, bcp);
                        if (error)
                                allerror = error;
                        blocksreleased += blkcount;
                        real_released += rblkcount;
                }
                lfs_blkfree(fs, ip, nb, lfs_sb_getbsize(fs), lastsegp, bcp);
                if (lfs_iblock_get(fs, bap, i) > 0)
                        real_released += nblocks;
                blocksreleased += nblocks;
        }

        /*
         * Recursively free last partial block.
         */
        if (level > SINGLE && lastbn >= 0) {
                last = lastbn % factor;
                nb = lfs_iblock_get(fs, bap, i);
                if (nb != 0) {
                        error = lfs_indirtrunc(ip, nlbn, nb,
                                               last, level - 1, &blkcount,
                                               &rblkcount, lastsegp, bcp);
                        if (error)
                                allerror = error;
                        real_released += rblkcount;
                        blocksreleased += blkcount;
                }
        }

        if (bap_needs_free) {
                lfs_free(fs, bap, LFS_NB_IBLOCK);
        } else {
                mutex_enter(&bufcache_lock);
                if (bp->b_oflags & BO_DELWRI) {
                        LFS_UNLOCK_BUF(bp);
                        lfs_sb_addavail(fs, lfs_btofsb(fs, bp->b_bcount));
                        wakeup(&fs->lfs_availsleep);
                }
                brelsel(bp, BC_INVAL);
                mutex_exit(&bufcache_lock);
        }

        *countp = blocksreleased;
        *rcountp = real_released;
        return (allerror);
}

/*
 * Destroy any in core blocks past the truncation length.
 * Inlined from vtruncbuf, so that lfs_avail could be updated.
 * We take the seglock to prevent cleaning from occurring while we are
 * invalidating blocks.
 */
static int
lfs_vtruncbuf(struct vnode *vp, daddr_t lbn, bool catch, int slptimeo)
{
        struct buf *bp, *nbp;
        int error = 0;
        struct lfs *fs;
        voff_t off;

        off = round_page((voff_t)lbn << vp->v_mount->mnt_fs_bshift);
        rw_enter(vp->v_uobj.vmobjlock, RW_WRITER);
        error = VOP_PUTPAGES(vp, off, 0, PGO_FREE | PGO_SYNCIO);
        if (error)
                return error;

        fs = VTOI(vp)->i_lfs;

        ASSERT_SEGLOCK(fs);

        mutex_enter(&bufcache_lock);
restart:        
        for (bp = LIST_FIRST(&vp->v_cleanblkhd); bp; bp = nbp) {
                nbp = LIST_NEXT(bp, b_vnbufs);
                if (bp->b_lblkno < lbn)
                        continue;
                error = bbusy(bp, catch, slptimeo, NULL);
                if (error == EPASSTHROUGH)
                        goto restart;
                if (error)
                        goto exit;

                mutex_enter(bp->b_objlock);
                if (bp->b_oflags & BO_DELWRI) {
                        bp->b_oflags &= ~BO_DELWRI;
                        lfs_sb_addavail(fs, lfs_btofsb(fs, bp->b_bcount));
                        wakeup(&fs->lfs_availsleep);
                }
                mutex_exit(bp->b_objlock);
                LFS_UNLOCK_BUF(bp);
                brelsel(bp, BC_INVAL | BC_VFLUSH);
        }

        for (bp = LIST_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) {
                nbp = LIST_NEXT(bp, b_vnbufs);
                if (bp->b_lblkno < lbn)
                        continue;
                error = bbusy(bp, catch, slptimeo, NULL);
                if (error == EPASSTHROUGH)
                        goto restart;
                if (error)
                        goto exit;

                mutex_enter(bp->b_objlock);
                if (bp->b_oflags & BO_DELWRI) {
                        bp->b_oflags &= ~BO_DELWRI;
                        lfs_sb_addavail(fs, lfs_btofsb(fs, bp->b_bcount));
                        wakeup(&fs->lfs_availsleep);
                }
                mutex_exit(bp->b_objlock);
                LFS_UNLOCK_BUF(bp);
                brelsel(bp, BC_INVAL | BC_VFLUSH);
        }
exit:
        mutex_exit(&bufcache_lock);

        return error;
}