/*      $OpenBSD: ffs_subr.c,v 1.35 2024/10/08 02:58:26 jsg Exp $       */
/*      $NetBSD: ffs_subr.c,v 1.6 1996/03/17 02:16:23 christos 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_subr.c  8.2 (Berkeley) 9/21/93
 */

#include <sys/param.h>
#include <ufs/ffs/fs.h>

#ifdef _KERNEL
#include <sys/systm.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/buf.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/ffs_extern.h>

/*
 * Return buffer with the contents of block "offset" from the beginning of
 * directory "ip".  If "res" is non-zero, fill it in with a pointer to the
 * remaining space in the directory.
 */
int
ffs_bufatoff(struct inode *ip, off_t offset, char **res, struct buf **bpp)
{
        struct fs *fs;
        struct vnode *vp;
        struct buf *bp;
        daddr_t lbn;
        int bsize, error;

        vp = ITOV(ip);
        fs = ip->i_fs;
        lbn = lblkno(fs, offset);
        bsize = blksize(fs, ip, lbn);

        *bpp = NULL;
        if ((error = bread(vp, lbn, fs->fs_bsize, &bp)) != 0) {
                brelse(bp);
                return (error);
        }
        buf_adjcnt(bp, bsize);
        if (res)
                *res = (char *)bp->b_data + blkoff(fs, offset);
        *bpp = bp;
        return (0);
}
#else
/* Prototypes for userland */
void    ffs_fragacct(struct fs *, int, int32_t[], int);
int     ffs_isfreeblock(struct fs *, u_char *, daddr_t);
int     ffs_isblock(struct fs *, u_char *, daddr_t);
void    ffs_clrblock(struct fs *, u_char *, daddr_t);
void    ffs_setblock(struct fs *, u_char *, daddr_t);
__dead void panic(const char *, ...);
#endif

/*
 * Update the frsum fields to reflect addition or deletion
 * of some frags.
 */
void
ffs_fragacct(struct fs *fs, int fragmap, int32_t fraglist[], int cnt)
{
        int inblk;
        int field, subfield;
        int siz, pos;

        inblk = (int)(fragtbl[fs->fs_frag][fragmap]) << 1;
        fragmap <<= 1;
        for (siz = 1; siz < fs->fs_frag; siz++) {
                if ((inblk & (1 << (siz + (fs->fs_frag % NBBY)))) == 0)
                        continue;
                field = around[siz];
                subfield = inside[siz];
                for (pos = siz; pos <= fs->fs_frag; pos++) {
                        if ((fragmap & field) == subfield) {
                                fraglist[siz] += cnt;
                                pos += siz;
                                field <<= siz;
                                subfield <<= siz;
                        }
                        field <<= 1;
                        subfield <<= 1;
                }
        }
}

/*
 * block operations
 *
 * check if a block is available
 */
int
ffs_isblock(struct fs *fs, u_char *cp, daddr_t h)
{
        u_char mask;

        switch (fs->fs_frag) {
        default:
        case 8:
                return (cp[h] == 0xff);
        case 4:
                mask = 0x0f << ((h & 0x1) << 2);
                return ((cp[h >> 1] & mask) == mask);
        case 2:
                mask = 0x03 << ((h & 0x3) << 1);
                return ((cp[h >> 2] & mask) == mask);
        case 1:
                mask = 0x01 << (h & 0x7);
                return ((cp[h >> 3] & mask) == mask);
        }
}

/*
 * take a block out of the map
 */
void
ffs_clrblock(struct fs *fs, u_char *cp, daddr_t h)
{

        switch (fs->fs_frag) {
        default:
        case 8:
                cp[h] = 0;
                return;
        case 4:
                cp[h >> 1] &= ~(0x0f << ((h & 0x1) << 2));
                return;
        case 2:
                cp[h >> 2] &= ~(0x03 << ((h & 0x3) << 1));
                return;
        case 1:
                cp[h >> 3] &= ~(0x01 << (h & 0x7));
                return;
        }
}

/*
 * put a block into the map
 */
void
ffs_setblock(struct fs *fs, u_char *cp, daddr_t h)
{

        switch (fs->fs_frag) {
        default:
        case 8:
                cp[h] = 0xff;
                return;
        case 4:
                cp[h >> 1] |= (0x0f << ((h & 0x1) << 2));
                return;
        case 2:
                cp[h >> 2] |= (0x03 << ((h & 0x3) << 1));
                return;
        case 1:
                cp[h >> 3] |= (0x01 << (h & 0x7));
                return;
        }
}

/*
 * check if a block is free
 */
int
ffs_isfreeblock(struct fs *fs, u_char *cp, daddr_t h)
{

        switch (fs->fs_frag) {
        default:
        case 8:
                return (cp[h] == 0);
        case 4:
                return ((cp[h >> 1] & (0x0f << ((h & 0x1) << 2))) == 0);
        case 2:
                return ((cp[h >> 2] & (0x03 << ((h & 0x3) << 1))) == 0);
        case 1:
                return ((cp[h >> 3] & (0x01 << (h & 0x7))) == 0);
        }
}

#ifdef _KERNEL
/*
 * Initialize the vnode associated with a new inode, handle aliased
 * vnodes.
 */
int
ffs_vinit(struct mount *mntp, struct vnode **vpp)
{
        struct inode *ip;
        struct vnode *vp, *nvp;
        struct timeval mtv;

        vp = *vpp;
        ip = VTOI(vp);
        switch(vp->v_type = IFTOVT(DIP(ip, mode))) {
        case VCHR:
        case VBLK:
                vp->v_op = &ffs_specvops;
                if ((nvp = checkalias(vp, DIP(ip, rdev), mntp)) != NULL) {
                        /*
                         * Discard unneeded vnode, but save its inode.
                         * Note that the lock is carried over in the inode
                         * to the replacement vnode.
                         */
                        nvp->v_data = vp->v_data;
                        vp->v_data = NULL;
                        vp->v_op = &spec_vops;
#ifdef VFSLCKDEBUG
                        vp->v_flag &= ~VLOCKSWORK;
#endif
                        vrele(vp);
                        vgone(vp);
                        /*
                         * Reinitialize aliased inode.
                         */
                        vp = nvp;
                        ip->i_vnode = vp;
                }
                break;
        case VFIFO:
#ifdef FIFO
                vp->v_op = &ffs_fifovops;
                break;
#else
                return (EOPNOTSUPP);
#endif
        case VNON:
        case VBAD:
        case VSOCK:
        case VLNK:
        case VDIR:
        case VREG:
                break;
        }
        if (ip->i_number == ROOTINO)
                vp->v_flag |= VROOT;
        /*
         * Initialize modrev times
         */
        getmicrouptime(&mtv);
        ip->i_modrev = (u_quad_t)mtv.tv_sec << 32;
        ip->i_modrev |= (u_quad_t)mtv.tv_usec * 4294;
        *vpp = vp;
        return (0);
}
#endif /* _KERNEL */