/*      $OpenBSD: ffs_inode.c,v 1.83 2024/02/03 18:51:58 beck Exp $     */
/*      $NetBSD: ffs_inode.c,v 1.10 1996/05/11 18:27:19 mycroft Exp $   */

/*
 * Copyright (c) 1982, 1986, 1989, 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.
 *
 *      @(#)ffs_inode.c 8.8 (Berkeley) 10/19/94
 */

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

#include <ufs/ufs/quota.h>
#include <ufs/ufs/inode.h>
#include <ufs/ufs/ufsmount.h>
#include <ufs/ufs/ufs_extern.h>

#include <ufs/ffs/fs.h>
#include <ufs/ffs/ffs_extern.h>

int ffs_indirtrunc(struct inode *, daddr_t, daddr_t, daddr_t, int, long *);

/*
 * Update the access, modified, and inode change times as specified by the
 * IN_ACCESS, IN_UPDATE, and IN_CHANGE flags respectively. The IN_MODIFIED
 * flag is used to specify that the inode needs to be updated but that the
 * times have already been set.  The IN_LAZYMOD flag is used to specify
 * that the inode needs to be updated at some point, by reclaim if not
 * in the course of other changes; this is used to defer writes just to
 * update device timestamps.  If waitfor is set, then wait for the disk
 * write of the inode to complete.
 */
int
ffs_update(struct inode *ip, int waitfor)
{
        struct vnode *vp;
        struct fs *fs;
        struct buf *bp;
        int error;

        vp = ITOV(ip);
        ufs_itimes(vp);

        if ((ip->i_flag & IN_MODIFIED) == 0 && waitfor == 0)
                return (0);

        ip->i_flag &= ~(IN_MODIFIED | IN_LAZYMOD);
        fs = ip->i_fs;

        /*
         * Ensure that uid and gid are correct. This is a temporary
         * fix until fsck has been changed to do the update.
         */
        if (fs->fs_magic == FS_UFS1_MAGIC && fs->fs_inodefmt < FS_44INODEFMT) {
                ip->i_din1->di_ouid = ip->i_ffs1_uid;
                ip->i_din1->di_ogid = ip->i_ffs1_gid;
        }

        error = bread(ip->i_devvp, fsbtodb(fs, ino_to_fsba(fs, ip->i_number)),
            (int)fs->fs_bsize, &bp);
        if (error) {
                brelse(bp);
                return (error);
        }

        if (ip->i_effnlink != DIP(ip, nlink))
                panic("ffs_update: bad link cnt");

#ifdef FFS2
        if (ip->i_ump->um_fstype == UM_UFS2)
                *((struct ufs2_dinode *)bp->b_data +
                    ino_to_fsbo(fs, ip->i_number)) = *ip->i_din2;
        else
#endif
                *((struct ufs1_dinode *)bp->b_data +
                    ino_to_fsbo(fs, ip->i_number)) = *ip->i_din1;

        if (waitfor && !DOINGASYNC(vp)) {
                return (bwrite(bp));
        } else {
                bdwrite(bp);
                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.
 */
int
ffs_truncate(struct inode *oip, off_t length, int flags, struct ucred *cred)
{
        struct vnode *ovp;
        daddr_t lastblock;
        daddr_t bn, lbn, lastiblock[NIADDR], indir_lbn[NIADDR];
        daddr_t oldblks[NDADDR + NIADDR], newblks[NDADDR + NIADDR];
        struct fs *fs;
        struct buf *bp;
        int offset, size, level;
        long count, nblocks, vflags, blocksreleased = 0;
        int i, aflags, error, allerror;
        off_t osize;

        if (length < 0)
                return (EINVAL);
        ovp = ITOV(oip);

        if (ovp->v_type != VREG &&
            ovp->v_type != VDIR &&
            ovp->v_type != VLNK)
                return (0);

        if (DIP(oip, size) == length)
                return (0);

        if (ovp->v_type == VLNK &&
            DIP(oip, size) < oip->i_ump->um_maxsymlinklen) {
#ifdef DIAGNOSTIC
                if (length != 0)
                        panic("ffs_truncate: partial truncate of symlink");
#endif
                memset(SHORTLINK(oip), 0, (size_t) DIP(oip, size));
                DIP_ASSIGN(oip, size, 0);
                oip->i_flag |= IN_CHANGE | IN_UPDATE;
                return (UFS_UPDATE(oip, 1));
        }

        if ((error = getinoquota(oip)) != 0)
                return (error);

        fs = oip->i_fs;
        if (length > fs->fs_maxfilesize)
                return (EFBIG);

        uvm_vnp_setsize(ovp, length);
        oip->i_ci.ci_lasta = oip->i_ci.ci_clen 
            = oip->i_ci.ci_cstart = oip->i_ci.ci_lastw = 0;

        osize = DIP(oip, size);
        /*
         * 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) {
                aflags = B_CLRBUF;
                if (flags & IO_SYNC)
                        aflags |= B_SYNC;
                error = UFS_BUF_ALLOC(oip, length - 1, 1, 
                                   cred, aflags, &bp);
                if (error)
                        return (error);
                DIP_ASSIGN(oip, size, length);
                uvm_vnp_setsize(ovp, length);
                (void) uvm_vnp_uncache(ovp);
                if (aflags & B_SYNC)
                        bwrite(bp);
                else
                        bawrite(bp);
                oip->i_flag |= IN_CHANGE | IN_UPDATE;
                return (UFS_UPDATE(oip, 1));
        }
        uvm_vnp_setsize(ovp, length);

        /*
         * 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 = blkoff(fs, length);
        if (offset == 0) {
                DIP_ASSIGN(oip, size, length);
        } else {
                lbn = lblkno(fs, length);
                aflags = B_CLRBUF;
                if (flags & IO_SYNC)
                        aflags |= B_SYNC;
                error = UFS_BUF_ALLOC(oip, length - 1, 1,
                                   cred, aflags, &bp);
                if (error)
                        return (error);
                DIP_ASSIGN(oip, size, length);
                size = blksize(fs, oip, lbn);
                (void) uvm_vnp_uncache(ovp);
                if (ovp->v_type != VDIR)
                        memset(bp->b_data + offset, 0, size - offset);
                buf_adjcnt(bp, size);
                if (aflags & B_SYNC)
                        bwrite(bp);
                else
                        bawrite(bp);
        }
        /*
         * 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 = lblkno(fs, length + fs->fs_bsize - 1) - 1;
        lastiblock[SINGLE] = lastblock - NDADDR;
        lastiblock[DOUBLE] = lastiblock[SINGLE] - NINDIR(fs);
        lastiblock[TRIPLE] = lastiblock[DOUBLE] - NINDIR(fs) * 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.
         */
        for (level = TRIPLE; level >= SINGLE; level--) {
                oldblks[NDADDR + level] = DIP(oip, ib[level]);
                if (lastiblock[level] < 0) {
                        DIP_ASSIGN(oip, ib[level], 0);
                        lastiblock[level] = -1;
                }
        }

        for (i = 0; i < NDADDR; i++) {
                oldblks[i] = DIP(oip, db[i]);
                if (i > lastblock)
                        DIP_ASSIGN(oip, db[i], 0);
        }

        oip->i_flag |= IN_CHANGE | IN_UPDATE;
        if ((error = UFS_UPDATE(oip, 1)) != 0)
                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 < NDADDR; i++) {
                newblks[i] = DIP(oip, db[i]);
                DIP_ASSIGN(oip, db[i], oldblks[i]);
        }

        for (i = 0; i < NIADDR; i++) {
                newblks[NDADDR + i] = DIP(oip, ib[i]);
                DIP_ASSIGN(oip, ib[i], oldblks[NDADDR + i]);
        }

        DIP_ASSIGN(oip, size, osize);
        vflags = ((length > 0) ? V_SAVE : 0) | V_SAVEMETA;
        allerror = vinvalbuf(ovp, vflags, cred, curproc, 0, INFSLP);

        /*
         * Indirect blocks first.
         */
        indir_lbn[SINGLE] = -NDADDR;
        indir_lbn[DOUBLE] = indir_lbn[SINGLE] - NINDIR(fs) - 1;
        indir_lbn[TRIPLE] = indir_lbn[DOUBLE] - NINDIR(fs) * NINDIR(fs) - 1;
        for (level = TRIPLE; level >= SINGLE; level--) {
                bn = DIP(oip, ib[level]);
                if (bn != 0) {
                        error = ffs_indirtrunc(oip, indir_lbn[level],
                            fsbtodb(fs, bn), lastiblock[level], level, &count);
                        if (error)
                                allerror = error;
                        blocksreleased += count;
                        if (lastiblock[level] < 0) {
                                DIP_ASSIGN(oip, ib[level], 0);
                                ffs_blkfree(oip, bn, fs->fs_bsize);
                                blocksreleased += nblocks;
                        }
                }
                if (lastiblock[level] >= 0)
                        goto done;
        }

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

                bn = DIP(oip, db[i]);
                if (bn == 0)
                        continue;

                DIP_ASSIGN(oip, db[i], 0);
                bsize = blksize(fs, oip, i);
                ffs_blkfree(oip, bn, bsize);
                blocksreleased += btodb(bsize);
        }
        if (lastblock < 0)
                goto done;

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

                /*
                 * Calculate amount of space we're giving
                 * back as old block size minus new block size.
                 */
                oldspace = blksize(fs, oip, lastblock);
                DIP_ASSIGN(oip, size, length);
                newspace = blksize(fs, oip, lastblock);
                if (newspace == 0)
                        panic("ffs_truncate: 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 += numfrags(fs, newspace);
                        ffs_blkfree(oip, bn, oldspace - newspace);
                        blocksreleased += btodb(oldspace - newspace);
                }
        }
done:
#ifdef DIAGNOSTIC
        for (level = SINGLE; level <= TRIPLE; level++)
                if (newblks[NDADDR + level] != DIP(oip, ib[level]))
                        panic("ffs_truncate1");
        for (i = 0; i < NDADDR; i++)
                if (newblks[i] != DIP(oip, db[i]))
                        panic("ffs_truncate2");
#endif /* DIAGNOSTIC */
        /*
         * Put back the real size.
         */
        DIP_ASSIGN(oip, size, length);
        if (DIP(oip, blocks) >= blocksreleased)
                DIP_ADD(oip, blocks, -blocksreleased);
        else    /* sanity */
                DIP_ASSIGN(oip, blocks, 0);
        oip->i_flag |= IN_CHANGE;
        (void)ufs_quota_free_blocks(oip, blocksreleased, NOCRED);
        return (allerror);
}

#ifdef FFS2
#define BAP(ip, i) (((ip)->i_ump->um_fstype == UM_UFS2) ? bap2[i] : bap1[i])
#define BAP_ASSIGN(ip, i, value)                                        \
        do {                                                            \
                if ((ip)->i_ump->um_fstype == UM_UFS2)                  \
                        bap2[i] = (value);                              \
                else                                                    \
                        bap1[i] = (value);                              \
        } while (0)
#else
#define BAP(ip, i) bap1[i]
#define BAP_ASSIGN(ip, i, value) do { bap1[i] = (value); } while (0)
#endif /* FFS2 */

/*
 * 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.
 */
int
ffs_indirtrunc(struct inode *ip, daddr_t lbn, daddr_t dbn,
    daddr_t lastbn, int level, long *countp)
{
        int i;
        struct buf *bp;
        struct fs *fs = ip->i_fs;
        struct vnode *vp;
        void *copy = NULL;
        daddr_t nb, nlbn, last;
        long blkcount, factor;
        int nblocks, blocksreleased = 0;
        int error = 0, allerror = 0;
        int32_t *bap1 = NULL;
#ifdef FFS2
        int64_t *bap2 = NULL;
#endif

        /*
         * 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 *= NINDIR(fs);
        last = lastbn;
        if (lastbn > 0)
                last /= factor;
        nblocks = btodb(fs->fs_bsize);
        /*
         * 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, (int)fs->fs_bsize, 0, INFSLP);
        if (!(bp->b_flags & (B_DONE | B_DELWRI))) {
                curproc->p_ru.ru_inblock++;             /* pay for read */
                bcstats.pendingreads++;
                bcstats.numreads++;
                bp->b_flags |= B_READ;
                if (bp->b_bcount > bp->b_bufsize)
                        panic("ffs_indirtrunc: bad buffer size");
                bp->b_blkno = dbn;
                VOP_STRATEGY(bp->b_vp, bp);
                error = biowait(bp);
        }
        if (error) {
                brelse(bp);
                *countp = 0;
                return (error);
        }

#ifdef FFS2
        if (ip->i_ump->um_fstype == UM_UFS2)
                bap2 = (int64_t *)bp->b_data;
        else
#endif
                bap1 = (int32_t *)bp->b_data;

        if (lastbn != -1) {
                copy = malloc(fs->fs_bsize, M_TEMP, M_WAITOK);
                memcpy(copy, bp->b_data, fs->fs_bsize);

                for (i = last + 1; i < NINDIR(fs); i++)
                        BAP_ASSIGN(ip, i, 0);

                if (!DOINGASYNC(vp)) {
                        error = bwrite(bp);
                        if (error)
                                allerror = error;
                } else {
                        bawrite(bp);
                }

#ifdef FFS2
                if (ip->i_ump->um_fstype == UM_UFS2)
                        bap2 = (int64_t *)copy;
                else
#endif
                        bap1 = (int32_t *)copy;
        }

        /*
         * Recursively free totally unused blocks.
         */
        for (i = NINDIR(fs) - 1, nlbn = lbn + 1 - i * factor; i > last;
            i--, nlbn += factor) {
                nb = BAP(ip, i);
                if (nb == 0)
                        continue;
                if (level > SINGLE) {
                        error = ffs_indirtrunc(ip, nlbn, fsbtodb(fs, nb),
                                               -1, level - 1, &blkcount);
                        if (error)
                                allerror = error;
                        blocksreleased += blkcount;
                }
                ffs_blkfree(ip, nb, fs->fs_bsize);
                blocksreleased += nblocks;
        }

        /*
         * Recursively free last partial block.
         */
        if (level > SINGLE && lastbn >= 0) {
                last = lastbn % factor;
                nb = BAP(ip, i);
                if (nb != 0) {
                        error = ffs_indirtrunc(ip, nlbn, fsbtodb(fs, nb),
                                               last, level - 1, &blkcount);
                        if (error)
                                allerror = error;
                        blocksreleased += blkcount;
                }
        }
        if (copy != NULL) {
                free(copy, M_TEMP, fs->fs_bsize);
        } else {
                bp->b_flags |= B_INVAL;
                brelse(bp);
        }
                
        *countp = blocksreleased;
        return (allerror);
}