cd9660_node.c

早期freebsd实现

			iso_iput(ip);
			ip = iq;
		}
	}
	
	if (ip->iso_extent == imp->root_extent)
		vp->v_flag |= VROOT;
	
	*ipp = ip;
	return 0;
}

/*
 * Unlock and decrement the reference count of an inode structure.
 */
iso_iput(ip)
	register struct iso_node *ip;
{
	
	if ((ip->i_flag & ILOCKED) == 0)
		panic("iso_iput");
	ISO_IUNLOCK(ip);
	vrele(ITOV(ip));
}

/*
 * Last reference to an inode, write the inode out and if necessary,
 * truncate and deallocate the file.
 */
int
cd9660_inactive(ap)
	struct vop_inactive_args /* {
		struct vnode *a_vp;
	} */ *ap;
{
	struct vnode *vp = ap->a_vp;
	register struct iso_node *ip = VTOI(vp);
	int mode, error = 0;
	
	if (prtactive && vp->v_usecount != 0)
		vprint("cd9660_inactive: pushing active", vp);
	
	ip->i_flag = 0;
	/*
	 * If we are done with the inode, reclaim it
	 * so that it can be reused immediately.
	 */
	if (vp->v_usecount == 0 && ip->inode.iso_mode == 0)
		vgone(vp);
	return error;
}

/*
 * Reclaim an inode so that it can be used for other purposes.
 */
int
cd9660_reclaim(ap)
	struct vop_reclaim_args /* {
		struct vnode *a_vp;
	} */ *ap;
{
	register struct vnode *vp = ap->a_vp;
	register struct iso_node *ip = VTOI(vp);
	int i;
	
	if (prtactive && vp->v_usecount != 0)
		vprint("cd9660_reclaim: pushing active", vp);
	/*
	 * Remove the inode from its hash chain.
	 */
	remque(ip);
	ip->i_forw = ip;
	ip->i_back = ip;
	/*
	 * Purge old data structures associated with the inode.
	 */
	cache_purge(vp);
	if (ip->i_devvp) {
		vrele(ip->i_devvp);
		ip->i_devvp = 0;
	}
	FREE(vp->v_data, M_ISOFSNODE);
	vp->v_data = NULL;
	return 0;
}

/*
 * Lock an inode. If its already locked, set the WANT bit and sleep.
 */
iso_ilock(ip)
	register struct iso_node *ip;
{
	
	while (ip->i_flag & ILOCKED) {
		ip->i_flag |= IWANT;
		if (ip->i_spare0 == curproc->p_pid)
			panic("locking against myself");
		ip->i_spare1 = curproc->p_pid;
		(void) sleep((caddr_t)ip, PINOD);
	}
	ip->i_spare1 = 0;
	ip->i_spare0 = curproc->p_pid;
	ip->i_flag |= ILOCKED;
}

/*
 * Unlock an inode.  If WANT bit is on, wakeup.
 */
iso_iunlock(ip)
	register struct iso_node *ip;
{

	if ((ip->i_flag & ILOCKED) == 0)
		vprint("iso_iunlock: unlocked inode", ITOV(ip));
	ip->i_spare0 = 0;
	ip->i_flag &= ~ILOCKED;
	if (ip->i_flag&IWANT) {
		ip->i_flag &= ~IWANT;
		wakeup((caddr_t)ip);
	}
}

/*
 * File attributes
 */
void
cd9660_defattr(isodir,inop,bp)
	struct iso_directory_record *isodir;
	struct iso_node *inop;
	struct buf *bp;
{
	struct buf *bp2 = NULL;
	struct iso_mnt *imp;
	struct iso_extended_attributes *ap = NULL;
	int off;
	
	if (isonum_711(isodir->flags)&2) {
		inop->inode.iso_mode = S_IFDIR;
		/*
		 * If we return 2, fts() will assume there are no subdirectories
		 * (just links for the path and .), so instead we return 1.
		 */
		inop->inode.iso_links = 1;
	} else {
		inop->inode.iso_mode = S_IFREG;
		inop->inode.iso_links = 1;
	}
	if (!bp
	    && ((imp = inop->i_mnt)->im_flags&ISOFSMNT_EXTATT)
	    && (off = isonum_711(isodir->ext_attr_length))) {
		iso_blkatoff(inop,-off * imp->logical_block_size,&bp2);
		bp = bp2;
	}
	if (bp) {
		ap = (struct iso_extended_attributes *)bp->b_un.b_addr;
		
		if (isonum_711(ap->version) == 1) {
			if (!(ap->perm[0]&0x40))
				inop->inode.iso_mode |= VEXEC >> 6;
			if (!(ap->perm[0]&0x10))
				inop->inode.iso_mode |= VREAD >> 6;
			if (!(ap->perm[0]&4))
				inop->inode.iso_mode |= VEXEC >> 3;
			if (!(ap->perm[0]&1))
				inop->inode.iso_mode |= VREAD >> 3;
			if (!(ap->perm[1]&0x40))
				inop->inode.iso_mode |= VEXEC;
			if (!(ap->perm[1]&0x10))
				inop->inode.iso_mode |= VREAD;
			inop->inode.iso_uid = isonum_723(ap->owner); /* what about 0? */
			inop->inode.iso_gid = isonum_723(ap->group); /* what about 0? */
		} else
			ap = NULL;
	}
	if (!ap) {
		inop->inode.iso_mode |= VREAD|VEXEC|(VREAD|VEXEC)>>3|(VREAD|VEXEC)>>6;
		inop->inode.iso_uid = (uid_t)0;
		inop->inode.iso_gid = (gid_t)0;
	}
	if (bp2)
		brelse(bp2);
}

/*
 * Time stamps
 */
void
cd9660_deftstamp(isodir,inop,bp)
	struct iso_directory_record *isodir;
	struct iso_node *inop;
	struct buf *bp;
{
	struct buf *bp2 = NULL;
	struct iso_mnt *imp;
	struct iso_extended_attributes *ap = NULL;
	int off;
	
	if (!bp
	    && ((imp = inop->i_mnt)->im_flags&ISOFSMNT_EXTATT)
	    && (off = isonum_711(isodir->ext_attr_length))) {
		iso_blkatoff(inop,-off * imp->logical_block_size,&bp2);
		bp = bp2;
	}
	if (bp) {
		ap = (struct iso_extended_attributes *)bp->b_un.b_addr;
		
		if (isonum_711(ap->version) == 1) {
			if (!cd9660_tstamp_conv17(ap->ftime,&inop->inode.iso_atime))
				cd9660_tstamp_conv17(ap->ctime,&inop->inode.iso_atime);
			if (!cd9660_tstamp_conv17(ap->ctime,&inop->inode.iso_ctime))
				inop->inode.iso_ctime = inop->inode.iso_atime;
			if (!cd9660_tstamp_conv17(ap->mtime,&inop->inode.iso_mtime))
				inop->inode.iso_mtime = inop->inode.iso_ctime;
		} else
			ap = NULL;
	}
	if (!ap) {
		cd9660_tstamp_conv7(isodir->date,&inop->inode.iso_ctime);
		inop->inode.iso_atime = inop->inode.iso_ctime;
		inop->inode.iso_mtime = inop->inode.iso_ctime;
	}
	if (bp2)
		brelse(bp2);
}

int
cd9660_tstamp_conv7(pi,pu)
char *pi;
struct timeval *pu;
{
	int i;
	int crtime, days;
	int y, m, d, hour, minute, second, tz;
	
	y = pi[0] + 1900;
	m = pi[1];
	d = pi[2];
	hour = pi[3];
	minute = pi[4];
	second = pi[5];
	tz = pi[6];
	
	if (y < 1970) {
		pu->tv_sec  = 0;
		pu->tv_usec = 0;
		return 0;
	} else {
#ifdef	ORIGINAL
		/* computes day number relative to Sept. 19th,1989 */
		/* don't even *THINK* about changing formula. It works! */
		days = 367*(y-1980)-7*(y+(m+9)/12)/4-3*((y+(m-9)/7)/100+1)/4+275*m/9+d-100;
#else
		/*
		 * Changed :-) to make it relative to Jan. 1st, 1970
		 * and to disambiguate negative division
		 */
		days = 367*(y-1960)-7*(y+(m+9)/12)/4-3*((y+(m+9)/12-1)/100+1)/4+275*m/9+d-239;
#endif
		crtime = ((((days * 24) + hour) * 60 + minute) * 60) + second;
		
		/* timezone offset is unreliable on some disks */
		if (-48 <= tz && tz <= 52)
			crtime += tz * 15 * 60;
	}
	pu->tv_sec  = crtime;
	pu->tv_usec = 0;
	return 1;
}

static unsigned
cd9660_chars2ui(begin,len)
	unsigned char *begin;
	int len;
{
	unsigned rc;
	
	for (rc = 0; --len >= 0;) {
		rc *= 10;
		rc += *begin++ - '0';
	}
	return rc;
}

int
cd9660_tstamp_conv17(pi,pu)
	unsigned char *pi;
	struct timeval *pu;
{
	unsigned char buf[7];
	
	/* year:"0001"-"9999" -> -1900  */
	buf[0] = cd9660_chars2ui(pi,4) - 1900;
	
	/* month: " 1"-"12"      -> 1 - 12 */
	buf[1] = cd9660_chars2ui(pi + 4,2);
	
	/* day:   " 1"-"31"      -> 1 - 31 */
	buf[2] = cd9660_chars2ui(pi + 6,2);
	
	/* hour:  " 0"-"23"      -> 0 - 23 */
	buf[3] = cd9660_chars2ui(pi + 8,2);
	
	/* minute:" 0"-"59"      -> 0 - 59 */
	buf[4] = cd9660_chars2ui(pi + 10,2);
	
	/* second:" 0"-"59"      -> 0 - 59 */
	buf[5] = cd9660_chars2ui(pi + 12,2);
	
	/* difference of GMT */
	buf[6] = pi[16];
	
	return cd9660_tstamp_conv7(buf,pu);
}

void
isodirino(inump,isodir,imp)
	ino_t *inump;
	struct iso_directory_record *isodir;
	struct iso_mnt *imp;
{
	*inump = (isonum_733(isodir->extent) + isonum_711(isodir->ext_attr_length))
		 * imp->logical_block_size;
}