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kernfs_vnops.c revision 1.15
      1 /*
      2  * Copyright (c) 1990, 1992 Jan-Simon Pendry
      3  * All rights reserved.
      4  *
      5  * This code is derived from software contributed to Berkeley by
      6  * Jan-Simon Pendry.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  * 1. Redistributions of source code must retain the above copyright
     12  *    notice, this list of conditions and the following disclaimer.
     13  * 2. Redistributions in binary form must reproduce the above copyright
     14  *    notice, this list of conditions and the following disclaimer in the
     15  *    documentation and/or other materials provided with the distribution.
     16  * 3. All advertising materials mentioning features or use of this software
     17  *    must display the following acknowledgement:
     18  *      This product includes software developed by the University of
     19  *      California, Berkeley and its contributors.
     20  * 4. Neither the name of the University nor the names of its contributors
     21  *    may be used to endorse or promote products derived from this software
     22  *    without specific prior written permission.
     23  *
     24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     34  * SUCH DAMAGE.
     35  *
     36  *	$Id: kernfs_vnops.c,v 1.15 1993/12/20 12:39:12 cgd Exp $
     37  */
     38 
     39 /*
     40  * Kernel parameter filesystem
     41  */
     42 
     43 #include <sys/param.h>
     44 #include <sys/systm.h>
     45 #include <sys/kernel.h>
     46 #include <sys/types.h>
     47 #include <sys/time.h>
     48 #include <sys/proc.h>
     49 #include <sys/file.h>
     50 #include <sys/vnode.h>
     51 #include <sys/stat.h>
     52 #include <sys/mount.h>
     53 #include <sys/namei.h>
     54 #include <sys/buf.h>
     55 
     56 #include <ufs/dir.h>		/* For readdir() XXX */
     57 
     58 #include <miscfs/kernfs/kernfs.h>
     59 
     60 struct kernfs_target kernfs_targets[] = {
     61 /* NOTE: The name must be less than UIO_MX-16 chars in length */
     62 DIR_TARGET(".",		0,		KTT_NULL,	KTM_DIR_PERMS	)
     63 DIR_TARGET("..",	0,		KTT_NULL,	KTM_DIR_PERMS	)
     64 REG_TARGET("copyright",	copyright,	KTT_STRING,	KTM_RO_PERMS	)
     65 REG_TARGET("hostname",	0,		KTT_HOSTNAME,	KTM_RW_PERMS	)
     66 REG_TARGET("hz",	&hz,		KTT_INT,	KTM_RO_PERMS	)
     67 REG_TARGET("loadavg",	0,		KTT_AVENRUN,	KTM_RO_PERMS	)
     68 REG_TARGET("physmem",	&physmem,	KTT_INT,	KTM_RO_PERMS	)
     69 #ifdef KERNFS_HAVE_ROOTDIR
     70 DIR_TARGET("root",	0,		KTT_NULL,	KTM_DIR_PERMS	)
     71 #endif
     72 BLK_TARGET("rootdev",	0,		KTT_NULL,	KTM_RO_PERMS	)
     73 CHR_TARGET("rrootdev",	0,		KTT_NULL,	KTM_RO_PERMS	)
     74 REG_TARGET("time",	0,		KTT_TIME,	KTM_RO_PERMS	)
     75 REG_TARGET("version",	version,	KTT_STRING,	KTM_RO_PERMS	)
     76 };
     77 
     78 static int nkernfs_targets = sizeof(kernfs_targets) / sizeof(kernfs_targets[0]);
     79 
     80 static int
     81 kernfs_xread(kt, buf, len, lenp)
     82 	struct kernfs_target *kt;
     83 	char *buf;
     84 	int len;
     85 	int *lenp;
     86 {
     87 	int xlen;
     88 
     89 	switch (kt->kt_tag) {
     90 	case KTT_TIME: {
     91 		struct timeval tv;
     92 		microtime(&tv);
     93 		sprintf(buf, "%d %d\n", tv.tv_sec, tv.tv_usec);
     94 		break;
     95 	}
     96 
     97 	case KTT_INT: {
     98 		int *ip = kt->kt_data;
     99 		sprintf(buf, "%d\n", *ip);
    100 		break;
    101 	}
    102 
    103 	case KTT_STRING: {
    104 		char *cp = kt->kt_data;
    105 		int xlen = strlen(cp) + 1;
    106 
    107 		if (xlen >= len)
    108 			return (EINVAL);
    109 
    110 		bcopy(cp, buf, xlen);
    111 		break;
    112 	}
    113 
    114 	case KTT_HOSTNAME: {
    115 		char *cp = hostname;
    116 		int xlen = hostnamelen;
    117 
    118 		if (xlen + 2 > len)	/* extra space for null and newline */
    119 			return (EINVAL);
    120 
    121 		bcopy(cp, buf, xlen);	/* safer than sprintf */
    122 		buf[xlen] = '\n';
    123 		buf[xlen+1] = '\0';
    124 		break;
    125 	}
    126 
    127 	case KTT_AVENRUN:
    128 		sprintf(buf, "%d %d %d %d\n",
    129 				averunnable.ldavg[0],
    130 				averunnable.ldavg[1],
    131 				averunnable.ldavg[2],
    132 				FSCALE);
    133 		break;
    134 
    135 	default:
    136 		return (EINVAL);
    137 	}
    138 
    139 	*lenp = strlen(buf);
    140 	return (0);
    141 }
    142 
    143 static int
    144 kernfs_xwrite(kt, buf, len)
    145 	struct kernfs_target *kt;
    146 	char *buf;
    147 	int len;
    148 {
    149 	switch (kt->kt_tag) {
    150 	case KTT_HOSTNAME: {
    151 		if (buf[len-1] == '\n')
    152 			--len;
    153 		bcopy(buf, hostname, len);
    154 		/* kernfs_write set buf[value_passed_as_len] = \0.
    155 		 * therefore, buf len (hostnamelen) = len.
    156 		 */
    157 		hostnamelen = len;
    158 		hostname[hostnamelen] = '\0';	/* null end of string. */
    159 		return (0);
    160 	}
    161 
    162 	default:
    163 		return (EIO);
    164 	}
    165 }
    166 
    167 /*
    168  * vp is the current namei directory
    169  * ndp is the name to locate in that directory...
    170  */
    171 kernfs_lookup(dvp, ndp, p)
    172 	struct vnode *dvp;
    173 	struct nameidata *ndp;
    174 	struct proc *p;
    175 {
    176 	char *pname = ndp->ni_ptr;
    177 	int error = ENOENT;
    178 	int i;
    179 	struct vnode *fvp;
    180 
    181 #ifdef KERNFS_DIAGNOSTIC
    182 	printf("kernfs_lookup(%s)\n", pname);
    183 #endif
    184 	if (ndp->ni_namelen == 1 && *pname == '.') {
    185 		ndp->ni_dvp = dvp;
    186 		ndp->ni_vp = dvp;
    187 		VREF(dvp);
    188 		/*VOP_LOCK(dvp);*/
    189 		return (0);
    190 	}
    191 
    192 #ifdef KERNFS_HAVE_ROOTDIR
    193 	if (ndp->ni_namelen == 4 && bcmp(pname, "root", 4) == 0) {
    194 		ndp->ni_dvp = dvp;
    195 		ndp->ni_vp = rootdir;
    196 		VREF(rootdir);
    197 		VOP_LOCK(rootdir);
    198 		return (0);
    199 	}
    200 #endif
    201 
    202 	/*
    203 	 * /kern/rootdev is the root device
    204 	 */
    205 	if (ndp->ni_namelen == 7 && bcmp(pname, "rootdev", 7) == 0) {
    206 		if (!rootvp) {
    207 			error = ENOENT;
    208 			goto bad;
    209 		}
    210 		ndp->ni_dvp = dvp;
    211 		ndp->ni_vp = rootvp;
    212 		VREF(rootvp);
    213 		VOP_LOCK(rootvp);
    214 		return (0);
    215 	}
    216 
    217 	/*
    218 	 * /kern/rrootdev is the raw root device
    219 	 */
    220 	if (ndp->ni_namelen == 8 && bcmp(pname, "rrootdev", 7) == 0) {
    221 		if (!rrootdevvp) {
    222 			error = ENOENT;
    223 			goto bad;
    224 		}
    225 		ndp->ni_dvp = dvp;
    226 		ndp->ni_vp = rrootdevvp;
    227 		VREF(rrootdevvp);
    228 		VOP_LOCK(rrootdevvp);
    229 		return (0);
    230 	}
    231 
    232 	for (i = 0; i < nkernfs_targets; i++) {
    233 		struct kernfs_target *kt = &kernfs_targets[i];
    234 		if (ndp->ni_namelen == strlen(kt->kt_name) &&
    235 		    bcmp(kt->kt_name, pname, ndp->ni_namelen) == 0) {
    236 			error = 0;
    237 			break;
    238 		}
    239 	}
    240 
    241 #ifdef KERNFS_DIAGNOSTIC
    242 	printf("kernfs_lookup: i = %d, error = %d\n", i, error);
    243 #endif
    244 
    245 	if (error)
    246 		goto bad;
    247 
    248 #ifdef KERNFS_DIAGNOSTIC
    249 	printf("kernfs_lookup: allocate new vnode\n");
    250 #endif
    251 	error = getnewvnode(VT_KERNFS, dvp->v_mount, &kernfs_vnodeops, &fvp);
    252 	if (error)
    253 		goto bad;
    254 	VTOKERN(fvp)->kf_kt = &kernfs_targets[i];
    255 	fvp->v_type = VTOKERN(fvp)->kf_kt->kt_vtype;
    256 	ndp->ni_dvp = dvp;
    257 	ndp->ni_vp = fvp;
    258 #ifdef KERNFS_DIAGNOSTIC
    259 	printf("kernfs_lookup: newvp = %x\n", fvp);
    260 #endif
    261 	return (0);
    262 
    263 bad:;
    264 	ndp->ni_dvp = dvp;
    265 	ndp->ni_vp = NULL;
    266 #ifdef KERNFS_DIAGNOSTIC
    267 	printf("kernfs_lookup: error = %d\n", error);
    268 #endif
    269 	return (error);
    270 }
    271 
    272 kernfs_open(vp, mode, cred, p)
    273 	struct vnode *vp;
    274 	int mode;
    275 	struct ucred *cred;
    276 	struct proc *p;
    277 {
    278 	/* if access succeeded, this always does, too */
    279 
    280 	return (0);
    281 }
    282 
    283 /*
    284  * Check mode permission on target pointer. Mode is READ, WRITE or EXEC.
    285  * The mode is shifted to select the owner/group/other fields. The
    286  * super user is granted all permissions.
    287  */
    288 kernfs_access(vp, mode, cred, p)
    289 	struct vnode *vp;
    290 	register int mode;
    291 	struct ucred *cred;
    292 	struct proc *p;
    293 {
    294 	struct kernfs_target *kt = VTOKERN(vp)->kf_kt;
    295 	register gid_t *gp;
    296 	int i, error;
    297 
    298 #ifdef KERN_DIAGNOSTIC
    299 	if (!VOP_ISLOCKED(vp)) {
    300 		vprint("kernfs_access: not locked", vp);
    301 		panic("kernfs_access: not locked");
    302 	}
    303 #endif
    304 	/*
    305 	 * If you're the super-user, you always get access.
    306 	 */
    307 	if (cred->cr_uid == 0)
    308 		return (0);
    309 	/*
    310 	 * Access check is based on only one of owner, group, public.
    311 	 * If not owner, then check group. If not a member of the
    312 	 * group, then check public access.
    313 	 */
    314 	if (cred->cr_uid != /* kt->kt_uid XXX */ 0) {
    315 		mode >>= 3;
    316 		gp = cred->cr_groups;
    317 		for (i = 0; i < cred->cr_ngroups; i++, gp++)
    318 			if (/* kt->kt_gid XXX */ 0 == *gp)
    319 				goto found;
    320 		mode >>= 3;
    321 found:
    322 		;
    323 	}
    324 	if ((kt->kt_perms & mode) == mode)
    325 		return (0);
    326 	return (EACCES);
    327 }
    328 
    329 kernfs_getattr(vp, vap, cred, p)
    330 	struct vnode *vp;
    331 	struct vattr *vap;
    332 	struct ucred *cred;
    333 	struct proc *p;
    334 {
    335 	int error = 0;
    336 	char strbuf[KSTRING];
    337 	struct kernfs_target *kt = VTOKERN(vp)->kf_kt;
    338 
    339 	bzero((caddr_t) vap, sizeof(*vap));
    340 	vattr_null(vap);
    341 	vap->va_uid = kt->kt_uid;
    342 	vap->va_gid = kt->kt_gid;
    343 	vap->va_fsid = vp->v_mount->mnt_stat.f_fsid.val[0];
    344 	/* vap->va_qsize = 0; */
    345 	vap->va_blocksize = DEV_BSIZE;
    346 	microtime(&vap->va_atime);
    347 	vap->va_mtime = vap->va_atime;
    348 	vap->va_ctime = vap->va_ctime;
    349 	vap->va_gen = 0;
    350 	vap->va_flags = 0;
    351 	vap->va_rdev = 0;
    352 	/* vap->va_qbytes = 0; */
    353 	vap->va_bytes = 0;
    354 	vap->va_type = kt->kt_vtype;
    355 	vap->va_mode = kt->kt_perms;
    356 
    357 	if (vp->v_flag & VROOT) {
    358 #ifdef KERNFS_DIAGNOSTIC
    359 		printf("kernfs_getattr: stat rootdir\n");
    360 #endif
    361 		vap->va_nlink = 2;
    362 		vap->va_fileid = 2;
    363 		vap->va_size = DEV_BSIZE;
    364 	} else {
    365 #ifdef KERNFS_DIAGNOSTIC
    366 		printf("kernfs_getattr: stat target %s\n", kt->kt_name);
    367 #endif
    368 		vap->va_nlink = 1;
    369 		vap->va_fileid = 3 + (kt - kernfs_targets) / sizeof(*kt);
    370 		error = kernfs_xread(kt, strbuf, sizeof(strbuf), &vap->va_size);
    371 	}
    372 
    373 	vp->v_type = vap->va_type;
    374 #ifdef KERNFS_DIAGNOSTIC
    375 	printf("kernfs_getattr: return error %d\n", error);
    376 #endif
    377 	return (error);
    378 }
    379 
    380 
    381 /*
    382  * Change the mode on a file.
    383  */
    384 kernfs_chmod1(vp, mode, p)
    385 	register struct vnode *vp;
    386 	register int mode;
    387 	struct proc *p;
    388 {
    389 	register struct ucred *cred = p->p_ucred;
    390 	register struct kernfs_target *kt = VTOKERN(vp)->kf_kt;
    391 	int error;
    392 
    393 	if ((mode & kt->kt_maxperms) != mode)	/* can't set ro var to rw */
    394 		return (EPERM);
    395 
    396 	if (cred->cr_uid != kt->kt_uid &&
    397 	    (error = suser(cred, &p->p_acflag)))
    398 		return (error);
    399 	if (cred->cr_uid) {
    400 		if (vp->v_type != VDIR && (mode & S_ISVTX))
    401 			return (EFTYPE);
    402 		if (!groupmember(kt->kt_gid, cred) && (mode & S_ISGID))
    403 			return (EPERM);
    404 	}
    405 	kt->kt_perms &= ~07777;
    406 	kt->kt_perms |= mode & 07777;
    407 /*	ip->i_flag |= ICHG;*/
    408 	return (0);
    409 }
    410 
    411 /*
    412  * Perform chown operation on kernfs_target kt
    413  */
    414 kernfs_chown1(vp, uid, gid, p)
    415 	register struct vnode *vp;
    416 	uid_t uid;
    417 	gid_t gid;
    418 	struct proc *p;
    419 {
    420 	register struct kernfs_target *kt = VTOKERN(vp)->kf_kt;
    421 	register struct ucred *cred = p->p_ucred;
    422 	uid_t ouid;
    423 	gid_t ogid;
    424 	int error = 0;
    425 
    426 	if (uid == (u_short)VNOVAL)
    427 		uid = kt->kt_uid;
    428 	if (gid == (u_short)VNOVAL)
    429 		gid = kt->kt_gid;
    430 	/*
    431 	 * If we don't own the file, are trying to change the owner
    432 	 * of the file, or are not a member of the target group,
    433 	 * the caller must be superuser or the call fails.
    434 	 */
    435 	if ((cred->cr_uid != kt->kt_uid || uid != kt->kt_uid ||
    436 	    !groupmember((gid_t)gid, cred)) &&
    437 	    (error = suser(cred, &p->p_acflag)))
    438 		return (error);
    439 	ouid = kt->kt_uid;
    440 	ogid = kt->kt_gid;
    441 
    442 	kt->kt_uid = uid;
    443 	kt->kt_gid = gid;
    444 
    445 /*	if (ouid != uid || ogid != gid)
    446 		ip->i_flag |= ICHG;*/
    447 	if (ouid != uid && cred->cr_uid != 0)
    448 		kt->kt_perms &= ~S_ISUID;
    449 	if (ogid != gid && cred->cr_uid != 0)
    450 		kt->kt_perms &= ~S_ISGID;
    451 	return (0);
    452 }
    453 
    454 /*
    455  * Set attribute vnode op. called from several syscalls
    456  */
    457 kernfs_setattr(vp, vap, cred, p)
    458 	struct vnode *vp;
    459 	struct vattr *vap;
    460 	struct ucred *cred;
    461 	struct proc *p;
    462 {
    463 	int error = 0;
    464 
    465 	/*
    466 	 * Check for unsetable attributes.
    467 	 */
    468 	if ((vap->va_type != VNON) || (vap->va_nlink != VNOVAL) ||
    469 	    (vap->va_fsid != VNOVAL) || (vap->va_fileid != VNOVAL) ||
    470 	    (vap->va_blocksize != VNOVAL) || (vap->va_rdev != VNOVAL) ||
    471 	    ((int)vap->va_bytes != VNOVAL) || (vap->va_gen != VNOVAL)) {
    472 		return (EINVAL);
    473 	}
    474 	/*
    475 	 * Go through the fields and update iff not VNOVAL.
    476 	 */
    477 	if (vap->va_uid != (u_short)VNOVAL || vap->va_gid != (u_short)VNOVAL)
    478 		if (error = kernfs_chown1(vp, vap->va_uid, vap->va_gid, p))
    479 			return (error);
    480 	if (vap->va_size != VNOVAL) {
    481 		if (vp->v_type == VDIR)
    482 			return (EISDIR);
    483 		/* else just nod and smile... */
    484 	}
    485 	if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL) {
    486 /*		if (cred->cr_uid != ip->i_uid &&
    487 		    (error = suser(cred, &p->p_acflag)))
    488 			return (error);
    489 		if (vap->va_atime.tv_sec != VNOVAL)
    490 			ip->i_flag |= IACC;
    491 		if (vap->va_mtime.tv_sec != VNOVAL)
    492 			ip->i_flag |= IUPD;
    493 		ip->i_flag |= ICHG;
    494 		if (error = iupdat(ip, &vap->va_atime, &vap->va_mtime, 1))
    495 			return (error);
    496 */
    497 	}
    498 	if (vap->va_mode != (u_short)VNOVAL)
    499 		error = kernfs_chmod1(vp, (int)vap->va_mode, p);
    500 	if (vap->va_flags != VNOVAL) {
    501 /*		if (cred->cr_uid != ip->i_uid &&
    502 		    (error = suser(cred, &p->p_acflag)))
    503 			return (error);
    504 		if (cred->cr_uid == 0) {
    505 			ip->i_flags = vap->va_flags;
    506 		} else {
    507 			ip->i_flags &= 0xffff0000;
    508 			ip->i_flags |= (vap->va_flags & 0xffff);
    509 		}
    510 		ip->i_flag |= ICHG;
    511 */
    512 	}
    513 	return (error);
    514 }
    515 
    516 static int
    517 kernfs_read(vp, uio, ioflag, cred)
    518 	struct vnode *vp;
    519 	struct uio *uio;
    520 	int ioflag;
    521 	struct ucred *cred;
    522 {
    523 	struct kernfs_target *kt = VTOKERN(vp)->kf_kt;
    524 	char strbuf[KSTRING];
    525 	int off = uio->uio_offset;
    526 	int len = 0;
    527 	char *cp = strbuf;
    528 	int error;
    529 #ifdef KERNFS_DIAGNOSTIC
    530 	printf("kern_read %s\n", kt->kt_name);
    531 #endif
    532 
    533 	error = kernfs_xread(kt, strbuf, sizeof(strbuf), &len);
    534 	if (error)
    535 		return (error);
    536 	cp = strbuf + off;
    537 	len -= off;
    538 	return (uiomove(cp, len, uio));
    539 }
    540 
    541 static int
    542 kernfs_write(vp, uio, ioflag, cred)
    543 	struct vnode *vp;
    544 	struct uio *uio;
    545 	int ioflag;
    546 	struct ucred *cred;
    547 {
    548 	struct kernfs_target *kt = VTOKERN(vp)->kf_kt;
    549 	char strbuf[KSTRING];
    550 	int len = uio->uio_resid;
    551 	char *cp = strbuf;
    552 	int xlen;
    553 	int error;
    554 
    555 	if (uio->uio_offset != 0)
    556 		return (EINVAL);
    557 
    558 	xlen = min(uio->uio_resid, KSTRING-1);
    559 	error = uiomove(strbuf, xlen, uio);
    560 	if (error)
    561 		return (error);
    562 
    563 	if (uio->uio_resid != 0)
    564 		return (EIO);
    565 
    566 	strbuf[xlen] = '\0';
    567 	return (kernfs_xwrite(kt, strbuf, xlen));
    568 }
    569 
    570 kernfs_readdir(vp, uio, cred, eofflagp, cookies, ncookies)
    571 	struct vnode *vp;
    572 	struct uio *uio;
    573 	struct ucred *cred;
    574 	int *eofflagp;
    575 	u_int *cookies;
    576 	int ncookies;
    577 {
    578 	struct filedesc *fdp;
    579 	int i;
    580 	int error;
    581 
    582 	i = uio->uio_offset / UIO_MX;
    583 	error = 0;
    584 	while (uio->uio_resid > 0 && (!cookies || ncookies > 0)) {
    585 #ifdef KERNFS_DIAGNOSTIC
    586 		printf("kernfs_readdir: i = %d\n", i);
    587 #endif
    588 		if (i >= nkernfs_targets) {
    589 			*eofflagp = 1;
    590 			break;
    591 		}
    592 		{
    593 			struct direct d;
    594 			struct direct *dp = &d;
    595 			struct kernfs_target *kt = &kernfs_targets[i];
    596 
    597 			bzero((caddr_t) dp, UIO_MX);
    598 
    599 			dp->d_namlen = strlen(kt->kt_name);
    600 			bcopy(kt->kt_name, dp->d_name, dp->d_namlen+1);
    601 
    602 #ifdef KERNFS_DIAGNOSTIC
    603 			printf("kernfs_readdir: name = %s, len = %d\n",
    604 					dp->d_name, dp->d_namlen);
    605 #endif
    606 			/*
    607 			 * Fill in the remaining fields
    608 			 */
    609 			dp->d_reclen = UIO_MX;
    610 			dp->d_ino = i + 3;
    611 			/*
    612 			 * And ship to userland
    613 			 */
    614 			error = uiomove((caddr_t) dp, UIO_MX, uio);
    615 			if (error)
    616 				break;
    617 			if (cookies) {
    618 				*cookies = (i + 1) * UIO_MX;
    619 				ncookies--;
    620 			}
    621 		}
    622 		i++;
    623 	}
    624 
    625 	uio->uio_offset = i * UIO_MX;
    626 
    627 	return (error);
    628 }
    629 
    630 kernfs_inactive(vp, p)
    631 	struct vnode *vp;
    632 	struct proc *p;
    633 {
    634 	/*
    635 	 * Clear out the v_type field to avoid
    636 	 * nasty things happening in vgone().
    637 	 */
    638 	vp->v_type = VNON;
    639 #ifdef KERNFS_DIAGNOSTIC
    640 	printf("kernfs_inactive(%x)\n", vp);
    641 #endif
    642 	return (0);
    643 }
    644 
    645 /*
    646  * Print out the contents of a kernfs vnode.
    647  */
    648 /* ARGSUSED */
    649 void
    650 kernfs_print(vp)
    651 	struct vnode *vp;
    652 {
    653 	printf("tag VT_KERNFS, kernfs vnode\n");
    654 }
    655 
    656 /*
    657  * kernfs vnode unsupported operation
    658  */
    659 kernfs_enotsupp()
    660 {
    661 	return (EOPNOTSUPP);
    662 }
    663 
    664 /*
    665  * kernfs "should never get here" operation
    666  */
    667 kernfs_badop()
    668 {
    669 	panic("kernfs: bad op");
    670 	/* NOTREACHED */
    671 }
    672 
    673 /*
    674  * kernfs vnode null operation
    675  */
    676 kernfs_nullop()
    677 {
    678 	return (0);
    679 }
    680 
    681 #define kernfs_create ((int (*) __P(( \
    682 		struct nameidata *ndp, \
    683 		struct vattr *vap, \
    684 		struct proc *p))) kernfs_enotsupp)
    685 #define kernfs_mknod ((int (*) __P(( \
    686 		struct nameidata *ndp, \
    687 		struct vattr *vap, \
    688 		struct ucred *cred, \
    689 		struct proc *p))) kernfs_enotsupp)
    690 #define kernfs_close ((int (*) __P(( \
    691 		struct vnode *vp, \
    692 		int fflag, \
    693 		struct ucred *cred, \
    694 		struct proc *p))) nullop)
    695 #define	kernfs_ioctl ((int (*) __P(( \
    696 		struct vnode *vp, \
    697 		int command, \
    698 		caddr_t data, \
    699 		int fflag, \
    700 		struct ucred *cred, \
    701 		struct proc *p))) kernfs_enotsupp)
    702 #define	kernfs_select ((int (*) __P(( \
    703 		struct vnode *vp, \
    704 		int which, \
    705 		int fflags, \
    706 		struct ucred *cred, \
    707 		struct proc *p))) kernfs_enotsupp)
    708 #define kernfs_mmap ((int (*) __P(( \
    709 		struct vnode *vp, \
    710 		int fflags, \
    711 		struct ucred *cred, \
    712 		struct proc *p))) kernfs_enotsupp)
    713 #define kernfs_fsync ((int (*) __P(( \
    714 		struct vnode *vp, \
    715 		int fflags, \
    716 		struct ucred *cred, \
    717 		int waitfor, \
    718 		struct proc *p))) nullop)
    719 #define kernfs_seek ((int (*) __P(( \
    720 		struct vnode *vp, \
    721 		off_t oldoff, \
    722 		off_t newoff, \
    723 		struct ucred *cred))) nullop)
    724 #define kernfs_remove ((int (*) __P(( \
    725 		struct nameidata *ndp, \
    726 		struct proc *p))) kernfs_enotsupp)
    727 #define kernfs_link ((int (*) __P(( \
    728 		struct vnode *vp, \
    729 		struct nameidata *ndp, \
    730 		struct proc *p))) kernfs_enotsupp)
    731 #define kernfs_rename ((int (*) __P(( \
    732 		struct nameidata *fndp, \
    733 		struct nameidata *tdnp, \
    734 		struct proc *p))) kernfs_enotsupp)
    735 #define kernfs_mkdir ((int (*) __P(( \
    736 		struct nameidata *ndp, \
    737 		struct vattr *vap, \
    738 		struct proc *p))) kernfs_enotsupp)
    739 #define kernfs_rmdir ((int (*) __P(( \
    740 		struct nameidata *ndp, \
    741 		struct proc *p))) kernfs_enotsupp)
    742 #define kernfs_symlink ((int (*) __P(( \
    743 		struct nameidata *ndp, \
    744 		struct vattr *vap, \
    745 		char *target, \
    746 		struct proc *p))) kernfs_enotsupp)
    747 #define kernfs_readlink ((int (*) __P(( \
    748 		struct vnode *vp, \
    749 		struct uio *uio, \
    750 		struct ucred *cred))) kernfs_enotsupp)
    751 #define kernfs_abortop ((int (*) __P(( \
    752 		struct nameidata *ndp))) nullop)
    753 #ifdef KERNFS_DIAGNOSTIC
    754 int kernfs_reclaim(vp)
    755 struct vnode *vp;
    756 {
    757 	printf("kernfs_reclaim(%x)\n", vp);
    758 	return (0);
    759 }
    760 #else
    761 #define kernfs_reclaim ((int (*) __P(( \
    762 		struct vnode *vp))) nullop)
    763 #endif
    764 #define	kernfs_lock ((int (*) __P(( \
    765 		struct vnode *vp))) nullop)
    766 #define kernfs_unlock ((int (*) __P(( \
    767 		struct vnode *vp))) nullop)
    768 #define	kernfs_bmap ((int (*) __P(( \
    769 		struct vnode *vp, \
    770 		daddr_t bn, \
    771 		struct vnode **vpp, \
    772 		daddr_t *bnp))) kernfs_badop)
    773 #define	kernfs_strategy ((int (*) __P(( \
    774 		struct buf *bp))) kernfs_badop)
    775 #define kernfs_islocked ((int (*) __P(( \
    776 		struct vnode *vp))) nullop)
    777 #define kernfs_advlock ((int (*) __P(( \
    778 		struct vnode *vp, \
    779 		caddr_t id, \
    780 		int op, \
    781 		struct flock *fl, \
    782 		int flags))) kernfs_enotsupp)
    783 
    784 struct vnodeops kernfs_vnodeops = {
    785 	kernfs_lookup,	/* lookup */
    786 	kernfs_create,	/* create */
    787 	kernfs_mknod,	/* mknod */
    788 	kernfs_open,	/* open */
    789 	kernfs_close,	/* close */
    790 	kernfs_access,	/* access */
    791 	kernfs_getattr,	/* getattr */
    792 	kernfs_setattr,	/* setattr */
    793 	kernfs_read,	/* read */
    794 	kernfs_write,	/* write */
    795 	kernfs_ioctl,	/* ioctl */
    796 	kernfs_select,	/* select */
    797 	kernfs_mmap,	/* mmap */
    798 	kernfs_fsync,	/* fsync */
    799 	kernfs_seek,	/* seek */
    800 	kernfs_remove,	/* remove */
    801 	kernfs_link,	/* link */
    802 	kernfs_rename,	/* rename */
    803 	kernfs_mkdir,	/* mkdir */
    804 	kernfs_rmdir,	/* rmdir */
    805 	kernfs_symlink,	/* symlink */
    806 	kernfs_readdir,	/* readdir */
    807 	kernfs_readlink,	/* readlink */
    808 	kernfs_abortop,	/* abortop */
    809 	kernfs_inactive,	/* inactive */
    810 	kernfs_reclaim,	/* reclaim */
    811 	kernfs_lock,	/* lock */
    812 	kernfs_unlock,	/* unlock */
    813 	kernfs_bmap,	/* bmap */
    814 	kernfs_strategy,	/* strategy */
    815 	kernfs_print,	/* print */
    816 	kernfs_islocked,	/* islocked */
    817 	kernfs_advlock,	/* advlock */
    818 };
    819