bsd/miscfs/umapfs/umap_vnops.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*      $NetBSD: umap_vnops.c,v 1.3 1994/08/19 11:25:42 mycroft Exp $   */
  23
  24 /*
  25  * Copyright (c) 1992, 1993
  26  *      The Regents of the University of California.  All rights reserved.
  27  *
  28  * This code is derived from software donated to Berkeley by
  29  * the UCLA Ficus project.
  30  *
  31  * Redistribution and use in source and binary forms, with or without
  32  * modification, are permitted provided that the following conditions
  33  * are met:
  34  * 1. Redistributions of source code must retain the above copyright
  35  *    notice, this list of conditions and the following disclaimer.
  36  * 2. Redistributions in binary form must reproduce the above copyright
  37  *    notice, this list of conditions and the following disclaimer in the
  38  *    documentation and/or other materials provided with the distribution.
  39  * 3. All advertising materials mentioning features or use of this software
  40  *    must display the following acknowledgement:
  41  *      This product includes software developed by the University of
  42  *      California, Berkeley and its contributors.
  43  * 4. Neither the name of the University nor the names of its contributors
  44  *    may be used to endorse or promote products derived from this software
  45  *    without specific prior written permission.
  46  *
  47  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  48  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  49  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  50  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  51  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  52  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  53  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  54  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  55  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  56  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  57  * SUCH DAMAGE.
  58  *
  59  *      @(#)umap_vnops.c        8.3 (Berkeley) 1/5/94
  60  */
  61
  62 /*
  63  * Umap Layer
  64  */
  65
  66 #include <sys/param.h>
  67 #include <sys/systm.h>
  68 #include <sys/time.h>
  69 #include <sys/types.h>
  70 #include <sys/vnode.h>
  71 #include <sys/mount.h>
  72 #include <sys/namei.h>
  73 #include <sys/malloc.h>
  74 #include <sys/buf.h>
  75 #include <miscfs/umapfs/umap.h>
  76
  77
  78 int umap_bug_bypass = 0;   /* for debugging: enables bypass printf'ing */
  79
  80 /*
  81  * This is the 10-Apr-92 bypass routine.
  82  * See null_vnops.c:null_bypass for more details.
  83  */
  84 int
  85 umap_bypass(ap)
  86         struct vop_generic_args /* {
  87                 struct vnodeop_desc *a_desc;
  88                 <other random data follows, presumably>
  89         } */ *ap;
  90 {
  91         extern int (**umap_vnodeop_p)(void *); /* not extern, really "forward" */
  92         struct ucred **credpp = 0, *credp = 0;
  93         struct ucred *savecredp, *savecompcredp = 0;
  94         struct ucred *compcredp = 0;
  95         struct vnode **this_vp_p;
  96         int error;
  97         struct vnode *old_vps[VDESC_MAX_VPS];
  98         struct vnode *vp1 = 0;
  99         struct vnode **vps_p[VDESC_MAX_VPS];
 100         struct vnode ***vppp;
 101         struct vnodeop_desc *descp = ap->a_desc;
 102         int reles, i;
 103         struct componentname **compnamepp = 0;
 104
 105         if (umap_bug_bypass)
 106                 printf ("umap_bypass: %s\n", descp->vdesc_name);
 107
 108 #ifdef SAFETY
 109         /*
 110          * We require at least one vp.
 111          */
 112         if (descp->vdesc_vp_offsets == NULL ||
 113             descp->vdesc_vp_offsets[0] == VDESC_NO_OFFSET)
 114                 panic ("umap_bypass: no vp's in map.\n");
 115 #endif
 116
 117         /*
 118          * Map the vnodes going in.
 119          * Later, we'll invoke the operation based on
 120          * the first mapped vnode's operation vector.
 121          */
 122         reles = descp->vdesc_flags;
 123         for (i = 0; i < VDESC_MAX_VPS; reles >>= 1, i++) {
 124                 if (descp->vdesc_vp_offsets[i] == VDESC_NO_OFFSET)
 125                         break;   /* bail out at end of list */
 126                 vps_p[i] = this_vp_p =
 127                         VOPARG_OFFSETTO(struct vnode**, descp->vdesc_vp_offsets[i], ap);
 128
 129                 if (i == 0) {
 130                         vp1 = *vps_p[0];
 131                 }
 132
 133                 /*
 134                  * We're not guaranteed that any but the first vnode
 135                  * are of our type.  Check for and don't map any
 136                  * that aren't.  (Must map first vp or vclean fails.)
 137                  */
 138
 139                 if (i && (*this_vp_p)->v_op != umap_vnodeop_p) {
 140                         old_vps[i] = NULL;
 141                 } else {
 142                         old_vps[i] = *this_vp_p;
 143                         *(vps_p[i]) = UMAPVPTOLOWERVP(*this_vp_p);
 144                         if (reles & 1)
 145                                 VREF(*this_vp_p);
 146                 }
 147
 148         }
 149
 150         /*
 151          * Fix the credentials.  (That's the purpose of this layer.)
 152          */
 153
 154         if (descp->vdesc_cred_offset != VDESC_NO_OFFSET) {
 155
 156                 credpp = VOPARG_OFFSETTO(struct ucred**,
 157                     descp->vdesc_cred_offset, ap);
 158
 159                 /* Save old values */
 160
 161                 savecredp = *credpp;
 162                 if (savecredp != NOCRED)
 163                         *credpp = crdup(savecredp);
 164                 credp = *credpp;
 165
 166                 if (umap_bug_bypass && credp->cr_uid != 0)
 167                         printf("umap_bypass: user was %d, group %d\n",
 168                             credp->cr_uid, credp->cr_gid);
 169
 170                 /* Map all ids in the credential structure. */
 171
 172                 umap_mapids(vp1->v_mount, credp);
 173
 174                 if (umap_bug_bypass && credp->cr_uid != 0)
 175                         printf("umap_bypass: user now %d, group %d\n",
 176                             credp->cr_uid, credp->cr_gid);
 177         }
 178
 179         /* BSD often keeps a credential in the componentname structure
 180          * for speed.  If there is one, it better get mapped, too.
 181          */
 182
 183         if (descp->vdesc_componentname_offset != VDESC_NO_OFFSET) {
 184
 185                 compnamepp = VOPARG_OFFSETTO(struct componentname**,
 186                     descp->vdesc_componentname_offset, ap);
 187
 188                 savecompcredp = (*compnamepp)->cn_cred;
 189                 if (savecompcredp != NOCRED)
 190                         (*compnamepp)->cn_cred = crdup(savecompcredp);
 191                 compcredp = (*compnamepp)->cn_cred;
 192
 193                 if (umap_bug_bypass && compcredp->cr_uid != 0)
 194                         printf("umap_bypass: component credit user was %d, group %d\n",
 195                             compcredp->cr_uid, compcredp->cr_gid);
 196
 197                 /* Map all ids in the credential structure. */
 198
 199                 umap_mapids(vp1->v_mount, compcredp);
 200
 201                 if (umap_bug_bypass && compcredp->cr_uid != 0)
 202                         printf("umap_bypass: component credit user now %d, group %d\n",
 203                             compcredp->cr_uid, compcredp->cr_gid);
 204         }
 205
 206         /*
 207          * Call the operation on the lower layer
 208          * with the modified argument structure.
 209          */
 210         error = VCALL(*(vps_p[0]), descp->vdesc_offset, ap);
 211
 212         /*
 213          * Maintain the illusion of call-by-value
 214          * by restoring vnodes in the argument structure
 215          * to their original value.
 216          */
 217         reles = descp->vdesc_flags;
 218         for (i = 0; i < VDESC_MAX_VPS; reles >>= 1, i++) {
 219                 if (descp->vdesc_vp_offsets[i] == VDESC_NO_OFFSET)
 220                         break;   /* bail out at end of list */
 221                 if (old_vps[i]) {
 222                         *(vps_p[i]) = old_vps[i];
 223                         if (reles & 1)
 224                                 vrele(*(vps_p[i]));
 225                 };
 226         };
 227
 228         /*
 229          * Map the possible out-going vpp
 230          * (Assumes that the lower layer always returns
 231          * a VREF'ed vpp unless it gets an error.)
 232          */
 233         if (descp->vdesc_vpp_offset != VDESC_NO_OFFSET &&
 234             !(descp->vdesc_flags & VDESC_NOMAP_VPP) &&
 235             !error) {
 236                 if (descp->vdesc_flags & VDESC_VPP_WILLRELE)
 237                         goto out;
 238                 vppp = VOPARG_OFFSETTO(struct vnode***,
 239                                  descp->vdesc_vpp_offset, ap);
 240                 error = umap_node_create(old_vps[0]->v_mount, **vppp, *vppp);
 241         };
 242
 243  out:
 244         /*
 245          * Free duplicate cred structure and restore old one.
 246          */
 247         if (descp->vdesc_cred_offset != VDESC_NO_OFFSET) {
 248                 if (umap_bug_bypass && credp && credp->cr_uid != 0)
 249                         printf("umap_bypass: returning-user was %d\n",
 250                                         credp->cr_uid);
 251
 252                 if (savecredp != NOCRED) {
 253                         if (credp != NOCRED)
 254                                 crfree(credp);
 255                         *credpp = savecredp;
 256                         if (umap_bug_bypass && credpp && (*credpp)->cr_uid != 0)
 257                                 printf("umap_bypass: returning-user now %d\n\n",
 258                                     savecredp->cr_uid);
 259                 }
 260         }
 261
 262         if (descp->vdesc_componentname_offset != VDESC_NO_OFFSET) {
 263                 if (umap_bug_bypass && compcredp && compcredp->cr_uid != 0)
 264                         printf("umap_bypass: returning-component-user was %d\n",
 265                                 compcredp->cr_uid);
 266
 267                 if (savecompcredp != NOCRED) {
 268                         if (compcredp != NOCRED)
 269                                 crfree(compcredp);
 270                         (*compnamepp)->cn_cred = savecompcredp;
 271                         if (umap_bug_bypass && credpp && (*credpp)->cr_uid != 0)
 272                                 printf("umap_bypass: returning-component-user now %d\n",
 273                                     savecompcredp->cr_uid);
 274                 }
 275         }
 276
 277         return (error);
 278 }
 279
 280
 281 /*
 282  *  We handle getattr to change the fsid.
 283  */
 284 int
 285 umap_getattr(ap)
 286         struct vop_getattr_args /* {
 287                 struct vnode *a_vp;
 288                 struct vattr *a_vap;
 289                 struct ucred *a_cred;
 290                 struct proc *a_p;
 291         } */ *ap;
 292 {
 293         uid_t uid;
 294         gid_t gid;
 295         int error, tmpid, nentries, gnentries;
 296         uid_t (*mapdata)[2];
 297         gid_t (*gmapdata)[2];
 298         struct vnode **vp1p;
 299         struct vnodeop_desc *descp = ap->a_desc;
 300
 301         if (error = umap_bypass(ap))
 302                 return (error);
 303         /* Requires that arguments be restored. */
 304         ap->a_vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid.val[0];
 305
 306         /*
 307          * Umap needs to map the uid and gid returned by a stat
 308          * into the proper values for this site.  This involves
 309          * finding the returned uid in the mapping information,
 310          * translating it into the uid on the other end,
 311          * and filling in the proper field in the vattr
 312          * structure pointed to by ap->a_vap.  The group
 313          * is easier, since currently all groups will be
 314          * translate to the NULLGROUP.
 315          */
 316
 317         /* Find entry in map */
 318
 319         uid = ap->a_vap->va_uid;
 320         gid = ap->a_vap->va_gid;
 321         if (umap_bug_bypass)
 322                 printf("umap_getattr: mapped uid = %d, mapped gid = %d\n", uid,
 323                     gid);
 324
 325         vp1p = VOPARG_OFFSETTO(struct vnode**, descp->vdesc_vp_offsets[0], ap);
 326         nentries =  MOUNTTOUMAPMOUNT((*vp1p)->v_mount)->info_nentries;
 327         mapdata =  (MOUNTTOUMAPMOUNT((*vp1p)->v_mount)->info_mapdata);
 328         gnentries =  MOUNTTOUMAPMOUNT((*vp1p)->v_mount)->info_gnentries;
 329         gmapdata =  (MOUNTTOUMAPMOUNT((*vp1p)->v_mount)->info_gmapdata);
 330
 331         /* Reverse map the uid for the vnode.  Since it's a reverse
 332                 map, we can't use umap_mapids() to do it. */
 333
 334         tmpid = umap_reverse_findid(uid, mapdata, nentries);
 335
 336         if (tmpid != -1) {
 337                 ap->a_vap->va_uid = (uid_t) tmpid;
 338                 if (umap_bug_bypass)
 339                         printf("umap_getattr: original uid = %d\n", uid);
 340         } else
 341                 ap->a_vap->va_uid = (uid_t) NOBODY;
 342
 343         /* Reverse map the gid for the vnode. */
 344
 345         tmpid = umap_reverse_findid(gid, gmapdata, gnentries);
 346
 347         if (tmpid != -1) {
 348                 ap->a_vap->va_gid = (gid_t) tmpid;
 349                 if (umap_bug_bypass)
 350                         printf("umap_getattr: original gid = %d\n", gid);
 351         } else
 352                 ap->a_vap->va_gid = (gid_t) NULLGROUP;
 353
 354         return (0);
 355 }
 356
 357 int
 358 umap_inactive(ap)
 359         struct vop_inactive_args /* {
 360                 struct vnode *a_vp;
 361         } */ *ap;
 362 {
 363         /*
 364          * Do nothing (and _don't_ bypass).
 365          * Wait to vrele lowervp until reclaim,
 366          * so that until then our umap_node is in the
 367          * cache and reusable.
 368          *
 369          */
 370         return (0);
 371 }
 372
 373 int
 374 umap_reclaim(ap)
 375         struct vop_reclaim_args /* {
 376                 struct vnode *a_vp;
 377         } */ *ap;
 378 {
 379         struct vnode *vp = ap->a_vp;
 380         struct umap_node *xp = VTOUMAP(vp);
 381         struct vnode *lowervp = xp->umap_lowervp;
 382
 383         /* After this assignment, this node will not be re-used. */
 384         xp->umap_lowervp = NULL;
 385         LIST_REMOVE(xp, umap_hash);
 386         FREE(vp->v_data, M_TEMP);
 387         vp->v_data = NULL;
 388         vrele(lowervp);
 389         return (0);
 390 }
 391
 392 int
 393 umap_strategy(ap)
 394         struct vop_strategy_args /* {
 395                 struct buf *a_bp;
 396         } */ *ap;
 397 {
 398         struct buf *bp = ap->a_bp;
 399         int error;
 400         struct vnode *savedvp;
 401
 402         savedvp = bp->b_vp;
 403         bp->b_vp = UMAPVPTOLOWERVP(bp->b_vp);
 404
 405         error = VOP_STRATEGY(ap->a_bp);
 406
 407         bp->b_vp = savedvp;
 408
 409         return (error);
 410 }
 411
 412 int
 413 umap_bwrite(ap)
 414         struct vop_bwrite_args /* {
 415                 struct buf *a_bp;
 416         } */ *ap;
 417 {
 418         struct buf *bp = ap->a_bp;
 419         int error;
 420         struct vnode *savedvp;
 421
 422         savedvp = bp->b_vp;
 423         bp->b_vp = UMAPVPTOLOWERVP(bp->b_vp);
 424
 425         error = VOP_BWRITE(ap->a_bp);
 426
 427         bp->b_vp = savedvp;
 428
 429         return (error);
 430 }
 431
 432
 433 int
 434 umap_print(ap)
 435         struct vop_print_args /* {
 436                 struct vnode *a_vp;
 437         } */ *ap;
 438 {
 439         struct vnode *vp = ap->a_vp;
 440         printf("\ttag VT_UMAPFS, vp=%x, lowervp=%x\n", vp, UMAPVPTOLOWERVP(vp));
 441         return (0);
 442 }
 443
 444 int
 445 umap_rename(ap)
 446         struct vop_rename_args  /* {
 447                 struct vnode *a_fdvp;
 448                 struct vnode *a_fvp;
 449                 struct componentname *a_fcnp;
 450                 struct vnode *a_tdvp;
 451                 struct vnode *a_tvp;
 452                 struct componentname *a_tcnp;
 453         } */ *ap;
 454 {
 455         int error;
 456         struct componentname *compnamep;
 457         struct ucred *compcredp, *savecompcredp;
 458         struct vnode *vp;
 459
 460         /*
 461          * Rename is irregular, having two componentname structures.
 462          * We need to map the cre in the second structure,
 463          * and then bypass takes care of the rest.
 464          */
 465
 466         vp = ap->a_fdvp;
 467         compnamep = ap->a_tcnp;
 468         compcredp = compnamep->cn_cred;
 469
 470         savecompcredp = compcredp;
 471         compcredp = compnamep->cn_cred = crdup(savecompcredp);
 472
 473         if (umap_bug_bypass && compcredp->cr_uid != 0)
 474                 printf("umap_rename: rename component credit user was %d, group %d\n",
 475                     compcredp->cr_uid, compcredp->cr_gid);
 476
 477         /* Map all ids in the credential structure. */
 478
 479         umap_mapids(vp->v_mount, compcredp);
 480
 481         if (umap_bug_bypass && compcredp->cr_uid != 0)
 482                 printf("umap_rename: rename component credit user now %d, group %d\n",
 483                     compcredp->cr_uid, compcredp->cr_gid);
 484
 485         error = umap_bypass(ap);
 486
 487         /* Restore the additional mapped componentname cred structure. */
 488
 489         crfree(compcredp);
 490         compnamep->cn_cred = savecompcredp;
 491
 492         return error;
 493 }
 494
 495 /*
 496  * Global vfs data structures
 497  */
 498 /*
 499  * XXX - strategy, bwrite are hand coded currently.  They should
 500  * go away with a merged buffer/block cache.
 501  *
 502  */
 503
 504 #define VOPFUNC int (*)(void *)
 505
 506 int (**umap_vnodeop_p)(void *);
 507 struct vnodeopv_entry_desc umap_vnodeop_entries[] = {
 508         { &vop_default_desc, (VOPFUNC)umap_bypass },
 509         { &vop_getattr_desc, (VOPFUNC)umap_getattr },
 510         { &vop_inactive_desc, (VOPFUNC)umap_inactive },
 511         { &vop_reclaim_desc, (VOPFUNC)umap_reclaim },
 512         { &vop_print_desc, (VOPFUNC)umap_print },
 513         { &vop_rename_desc, (VOPFUNC)umap_rename },
 514         { &vop_strategy_desc, (VOPFUNC)umap_strategy },
 515         { &vop_bwrite_desc, (VOPFUNC)umap_bwrite },
 516
 517         { (struct vnodeop_desc*) NULL, (int(*)()) NULL }
 518 };
 519 struct vnodeopv_desc umap_vnodeop_opv_desc =
 520         { &umap_vnodeop_p, umap_vnodeop_entries };