1 /* $NetBSD: umap_vnops.c,v 1.12 1999/03/22 17:24:22 sommerfe Exp $ */ 2 3 /* 4 * Copyright (c) 1992, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software donated to Berkeley by 8 * the UCLA Ficus project. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * @(#)umap_vnops.c 8.6 (Berkeley) 5/22/95 39 */ 40 41 /* 42 * Umap Layer 43 */ 44 45 #include <sys/param.h> 46 #include <sys/systm.h> 47 #include <sys/time.h> 48 #include <sys/types.h> 49 #include <sys/vnode.h> 50 #include <sys/mount.h> 51 #include <sys/namei.h> 52 #include <sys/malloc.h> 53 #include <sys/buf.h> 54 #include <miscfs/umapfs/umap.h> 55 #include <miscfs/genfs/genfs.h> 56 57 58 int umap_bug_bypass = 0; /* for debugging: enables bypass printf'ing */ 59 60 int umap_bypass __P((void *)); 61 int umap_getattr __P((void *)); 62 int umap_inactive __P((void *)); 63 int umap_reclaim __P((void *)); 64 int umap_print __P((void *)); 65 int umap_rename __P((void *)); 66 int umap_strategy __P((void *)); 67 int umap_bwrite __P((void *)); 68 int umap_lock __P((void *)); 69 int umap_unlock __P((void *)); 70 int umap_fsync __P((void *)); 71 72 extern int null_bypass __P((void *)); 73 74 /* 75 * Global vfs data structures 76 */ 77 /* 78 * XXX - strategy, bwrite are hand coded currently. They should 79 * go away with a merged buffer/block cache. 80 * 81 */ 82 int (**umap_vnodeop_p) __P((void *)); 83 struct vnodeopv_entry_desc umap_vnodeop_entries[] = { 84 { &vop_default_desc, umap_bypass }, 85 86 { &vop_getattr_desc, umap_getattr }, 87 { &vop_lock_desc, umap_lock }, 88 { &vop_unlock_desc, umap_unlock }, 89 { &vop_fsync_desc, umap_fsync }, 90 { &vop_inactive_desc, umap_inactive }, 91 { &vop_reclaim_desc, umap_reclaim }, 92 { &vop_print_desc, umap_print }, 93 { &vop_rename_desc, umap_rename }, 94 95 { &vop_strategy_desc, umap_strategy }, 96 { &vop_bwrite_desc, umap_bwrite }, 97 98 { (struct vnodeop_desc*) NULL, (int(*) __P((void *))) NULL } 99 }; 100 struct vnodeopv_desc umapfs_vnodeop_opv_desc = 101 { &umap_vnodeop_p, umap_vnodeop_entries }; 102 103 /* 104 * This is the 10-Apr-92 bypass routine. 105 * See null_vnops.c:null_bypass for more details. 106 */ 107 int 108 umap_bypass(v) 109 void *v; 110 { 111 struct vop_generic_args /* { 112 struct vnodeop_desc *a_desc; 113 <other random data follows, presumably> 114 } */ *ap = v; 115 struct ucred **credpp = 0, *credp = 0; 116 struct ucred *savecredp = 0, *savecompcredp = 0; 117 struct ucred *compcredp = 0; 118 struct vnode **this_vp_p; 119 int error; 120 struct vnode *old_vps[VDESC_MAX_VPS]; 121 struct vnode *vp1 = 0; 122 struct vnode **vps_p[VDESC_MAX_VPS]; 123 struct vnode ***vppp; 124 struct vnodeop_desc *descp = ap->a_desc; 125 int reles, i; 126 struct componentname **compnamepp = 0; 127 128 if (umap_bug_bypass) 129 printf("umap_bypass: %s\n", descp->vdesc_name); 130 131 #ifdef SAFETY 132 /* 133 * We require at least one vp. 134 */ 135 if (descp->vdesc_vp_offsets == NULL || 136 descp->vdesc_vp_offsets[0] == VDESC_NO_OFFSET) 137 panic ("umap_bypass: no vp's in map.\n"); 138 #endif 139 140 /* 141 * Map the vnodes going in. 142 * Later, we'll invoke the operation based on 143 * the first mapped vnode's operation vector. 144 */ 145 reles = descp->vdesc_flags; 146 for (i = 0; i < VDESC_MAX_VPS; reles >>= 1, i++) { 147 if (descp->vdesc_vp_offsets[i] == VDESC_NO_OFFSET) 148 break; /* bail out at end of list */ 149 vps_p[i] = this_vp_p = 150 VOPARG_OFFSETTO(struct vnode**, descp->vdesc_vp_offsets[i], ap); 151 152 if (i == 0) { 153 vp1 = *vps_p[0]; 154 } 155 156 /* 157 * We're not guaranteed that any but the first vnode 158 * are of our type. Check for and don't map any 159 * that aren't. (Must map first vp or vclean fails.) 160 */ 161 162 if (i && ((*this_vp_p)==NULL || (*this_vp_p)->v_op != umap_vnodeop_p)) { 163 old_vps[i] = NULL; 164 } else { 165 old_vps[i] = *this_vp_p; 166 *(vps_p[i]) = UMAPVPTOLOWERVP(*this_vp_p); 167 if (reles & 1) 168 VREF(*this_vp_p); 169 } 170 171 } 172 173 /* 174 * Fix the credentials. (That's the purpose of this layer.) 175 */ 176 177 if (descp->vdesc_cred_offset != VDESC_NO_OFFSET) { 178 179 credpp = VOPARG_OFFSETTO(struct ucred**, 180 descp->vdesc_cred_offset, ap); 181 182 /* Save old values */ 183 184 savecredp = *credpp; 185 if (savecredp != NOCRED) 186 *credpp = crdup(savecredp); 187 credp = *credpp; 188 189 if (umap_bug_bypass && credp->cr_uid != 0) 190 printf("umap_bypass: user was %d, group %d\n", 191 credp->cr_uid, credp->cr_gid); 192 193 /* Map all ids in the credential structure. */ 194 195 umap_mapids(vp1->v_mount, credp); 196 197 if (umap_bug_bypass && credp->cr_uid != 0) 198 printf("umap_bypass: user now %d, group %d\n", 199 credp->cr_uid, credp->cr_gid); 200 } 201 202 /* BSD often keeps a credential in the componentname structure 203 * for speed. If there is one, it better get mapped, too. 204 */ 205 206 if (descp->vdesc_componentname_offset != VDESC_NO_OFFSET) { 207 208 compnamepp = VOPARG_OFFSETTO(struct componentname**, 209 descp->vdesc_componentname_offset, ap); 210 211 savecompcredp = (*compnamepp)->cn_cred; 212 if (savecompcredp != NOCRED) 213 (*compnamepp)->cn_cred = crdup(savecompcredp); 214 compcredp = (*compnamepp)->cn_cred; 215 216 if (umap_bug_bypass && compcredp->cr_uid != 0) 217 printf("umap_bypass: component credit user was %d, group %d\n", 218 compcredp->cr_uid, compcredp->cr_gid); 219 220 /* Map all ids in the credential structure. */ 221 222 umap_mapids(vp1->v_mount, compcredp); 223 224 if (umap_bug_bypass && compcredp->cr_uid != 0) 225 printf("umap_bypass: component credit user now %d, group %d\n", 226 compcredp->cr_uid, compcredp->cr_gid); 227 } 228 229 /* 230 * Call the operation on the lower layer 231 * with the modified argument structure. 232 */ 233 error = VCALL(*(vps_p[0]), descp->vdesc_offset, ap); 234 235 /* 236 * Maintain the illusion of call-by-value 237 * by restoring vnodes in the argument structure 238 * to their original value. 239 */ 240 reles = descp->vdesc_flags; 241 for (i = 0; i < VDESC_MAX_VPS; reles >>= 1, i++) { 242 if (descp->vdesc_vp_offsets[i] == VDESC_NO_OFFSET) 243 break; /* bail out at end of list */ 244 if (old_vps[i]) { 245 *(vps_p[i]) = old_vps[i]; 246 if (reles & 1) 247 vrele(*(vps_p[i])); 248 }; 249 }; 250 251 /* 252 * Map the possible out-going vpp 253 * (Assumes that the lower layer always returns 254 * a VREF'ed vpp unless it gets an error.) 255 */ 256 if (descp->vdesc_vpp_offset != VDESC_NO_OFFSET && 257 !(descp->vdesc_flags & VDESC_NOMAP_VPP) && 258 !error) { 259 if (descp->vdesc_flags & VDESC_VPP_WILLRELE) 260 goto out; 261 vppp = VOPARG_OFFSETTO(struct vnode***, 262 descp->vdesc_vpp_offset, ap); 263 error = umap_node_create(old_vps[0]->v_mount, **vppp, *vppp); 264 }; 265 266 out: 267 /* 268 * Free duplicate cred structure and restore old one. 269 */ 270 if (descp->vdesc_cred_offset != VDESC_NO_OFFSET) { 271 if (umap_bug_bypass && credp && credp->cr_uid != 0) 272 printf("umap_bypass: returning-user was %d\n", 273 credp->cr_uid); 274 275 if (savecredp != NOCRED) { 276 crfree(credp); 277 *credpp = savecredp; 278 if (umap_bug_bypass && credpp && (*credpp)->cr_uid != 0) 279 printf("umap_bypass: returning-user now %d\n\n", 280 savecredp->cr_uid); 281 } 282 } 283 284 if (descp->vdesc_componentname_offset != VDESC_NO_OFFSET) { 285 if (umap_bug_bypass && compcredp && compcredp->cr_uid != 0) 286 printf("umap_bypass: returning-component-user was %d\n", 287 compcredp->cr_uid); 288 289 if (savecompcredp != NOCRED) { 290 crfree(compcredp); 291 (*compnamepp)->cn_cred = savecompcredp; 292 if (umap_bug_bypass && credpp && (*credpp)->cr_uid != 0) 293 printf("umap_bypass: returning-component-user now %d\n", 294 savecompcredp->cr_uid); 295 } 296 } 297 298 return (error); 299 } 300 301 /* 302 * We need to process our own vnode lock and then clear the 303 * interlock flag as it applies only to our vnode, not the 304 * vnodes below us on the stack. 305 */ 306 int 307 umap_lock(v) 308 void *v; 309 { 310 struct vop_lock_args /* { 311 struct vnode *a_vp; 312 int a_flags; 313 struct proc *a_p; 314 } */ *ap = v; 315 316 genfs_nolock(ap); 317 if ((ap->a_flags & LK_TYPE_MASK) == LK_DRAIN) 318 return (0); 319 ap->a_flags &= ~LK_INTERLOCK; 320 return (null_bypass(ap)); 321 } 322 323 /* 324 * We need to process our own vnode unlock and then clear the 325 * interlock flag as it applies only to our vnode, not the 326 * vnodes below us on the stack. 327 */ 328 int 329 umap_unlock(v) 330 void *v; 331 { 332 struct vop_unlock_args /* { 333 struct vnode *a_vp; 334 int a_flags; 335 struct proc *a_p; 336 } */ *ap = v; 337 338 genfs_nounlock(ap); 339 ap->a_flags &= ~LK_INTERLOCK; 340 return (null_bypass(ap)); 341 } 342 343 /* 344 * If vinvalbuf is calling us, it's a "shallow fsync" -- don't bother 345 * syncing the underlying vnodes, since (a) they'll be fsync'ed when 346 * reclaimed and (b) we could deadlock if they're locked; otherwise, 347 * pass it through to the underlying layer. 348 */ 349 350 int 351 umap_fsync(v) 352 void *v; 353 { 354 struct vop_fsync_args /* { 355 struct vnode *a_vp; 356 struct ucred *a_cred; 357 int a_flags; 358 struct proc *a_p; 359 } */ *ap = v; 360 361 if (ap->a_flags & FSYNC_RECLAIM) 362 return 0; 363 364 return (umap_bypass(ap)); 365 } 366 367 /* 368 * We handle getattr to change the fsid. 369 */ 370 int 371 umap_getattr(v) 372 void *v; 373 { 374 struct vop_getattr_args /* { 375 struct vnode *a_vp; 376 struct vattr *a_vap; 377 struct ucred *a_cred; 378 struct proc *a_p; 379 } */ *ap = v; 380 uid_t uid; 381 gid_t gid; 382 int error, tmpid, nentries, gnentries; 383 u_long (*mapdata)[2]; 384 u_long (*gmapdata)[2]; 385 struct vnode **vp1p; 386 struct vnodeop_desc *descp = ap->a_desc; 387 388 if ((error = umap_bypass(ap)) != 0) 389 return (error); 390 /* Requires that arguments be restored. */ 391 ap->a_vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid.val[0]; 392 393 /* 394 * Umap needs to map the uid and gid returned by a stat 395 * into the proper values for this site. This involves 396 * finding the returned uid in the mapping information, 397 * translating it into the uid on the other end, 398 * and filling in the proper field in the vattr 399 * structure pointed to by ap->a_vap. The group 400 * is easier, since currently all groups will be 401 * translate to the NULLGROUP. 402 */ 403 404 /* Find entry in map */ 405 406 uid = ap->a_vap->va_uid; 407 gid = ap->a_vap->va_gid; 408 if (umap_bug_bypass) 409 printf("umap_getattr: mapped uid = %d, mapped gid = %d\n", uid, 410 gid); 411 412 vp1p = VOPARG_OFFSETTO(struct vnode**, descp->vdesc_vp_offsets[0], ap); 413 nentries = MOUNTTOUMAPMOUNT((*vp1p)->v_mount)->info_nentries; 414 mapdata = (MOUNTTOUMAPMOUNT((*vp1p)->v_mount)->info_mapdata); 415 gnentries = MOUNTTOUMAPMOUNT((*vp1p)->v_mount)->info_gnentries; 416 gmapdata = (MOUNTTOUMAPMOUNT((*vp1p)->v_mount)->info_gmapdata); 417 418 /* Reverse map the uid for the vnode. Since it's a reverse 419 map, we can't use umap_mapids() to do it. */ 420 421 tmpid = umap_reverse_findid(uid, mapdata, nentries); 422 423 if (tmpid != -1) { 424 ap->a_vap->va_uid = (uid_t) tmpid; 425 if (umap_bug_bypass) 426 printf("umap_getattr: original uid = %d\n", uid); 427 } else 428 ap->a_vap->va_uid = (uid_t) NOBODY; 429 430 /* Reverse map the gid for the vnode. */ 431 432 tmpid = umap_reverse_findid(gid, gmapdata, gnentries); 433 434 if (tmpid != -1) { 435 ap->a_vap->va_gid = (gid_t) tmpid; 436 if (umap_bug_bypass) 437 printf("umap_getattr: original gid = %d\n", gid); 438 } else 439 ap->a_vap->va_gid = (gid_t) NULLGROUP; 440 441 return (0); 442 } 443 444 /*ARGSUSED*/ 445 int 446 umap_inactive(v) 447 void *v; 448 { 449 struct vop_inactive_args /* { 450 struct vnode *a_vp; 451 struct proc *a_p; 452 } */ *ap = v; 453 /* 454 * Do nothing (and _don't_ bypass). 455 * Wait to vrele lowervp until reclaim, 456 * so that until then our umap_node is in the 457 * cache and reusable. 458 * 459 */ 460 VOP_UNLOCK(ap->a_vp, 0); 461 return (0); 462 } 463 464 int 465 umap_reclaim(v) 466 void *v; 467 { 468 struct vop_reclaim_args /* { 469 struct vnode *a_vp; 470 } */ *ap = v; 471 struct vnode *vp = ap->a_vp; 472 struct umap_node *xp = VTOUMAP(vp); 473 struct vnode *lowervp = xp->umap_lowervp; 474 475 /* After this assignment, this node will not be re-used. */ 476 xp->umap_lowervp = NULL; 477 LIST_REMOVE(xp, umap_hash); 478 FREE(vp->v_data, M_TEMP); 479 vp->v_data = NULL; 480 vrele(lowervp); 481 return (0); 482 } 483 484 int 485 umap_strategy(v) 486 void *v; 487 { 488 struct vop_strategy_args /* { 489 struct buf *a_bp; 490 } */ *ap = v; 491 struct buf *bp = ap->a_bp; 492 int error; 493 struct vnode *savedvp; 494 495 savedvp = bp->b_vp; 496 bp->b_vp = UMAPVPTOLOWERVP(bp->b_vp); 497 498 error = VOP_STRATEGY(ap->a_bp); 499 500 bp->b_vp = savedvp; 501 502 return (error); 503 } 504 505 int 506 umap_bwrite(v) 507 void *v; 508 { 509 struct vop_bwrite_args /* { 510 struct buf *a_bp; 511 } */ *ap = v; 512 struct buf *bp = ap->a_bp; 513 int error; 514 struct vnode *savedvp; 515 516 savedvp = bp->b_vp; 517 bp->b_vp = UMAPVPTOLOWERVP(bp->b_vp); 518 519 error = VOP_BWRITE(ap->a_bp); 520 521 bp->b_vp = savedvp; 522 523 return (error); 524 } 525 526 527 int 528 umap_print(v) 529 void *v; 530 { 531 struct vop_print_args /* { 532 struct vnode *a_vp; 533 } */ *ap = v; 534 struct vnode *vp = ap->a_vp; 535 printf("\ttag VT_UMAPFS, vp=%p, lowervp=%p\n", vp, 536 UMAPVPTOLOWERVP(vp)); 537 return (0); 538 } 539 540 int 541 umap_rename(v) 542 void *v; 543 { 544 struct vop_rename_args /* { 545 struct vnode *a_fdvp; 546 struct vnode *a_fvp; 547 struct componentname *a_fcnp; 548 struct vnode *a_tdvp; 549 struct vnode *a_tvp; 550 struct componentname *a_tcnp; 551 } */ *ap = v; 552 int error; 553 struct componentname *compnamep; 554 struct ucred *compcredp, *savecompcredp; 555 struct vnode *vp; 556 557 /* 558 * Rename is irregular, having two componentname structures. 559 * We need to map the cre in the second structure, 560 * and then bypass takes care of the rest. 561 */ 562 563 vp = ap->a_fdvp; 564 compnamep = ap->a_tcnp; 565 compcredp = compnamep->cn_cred; 566 567 savecompcredp = compcredp; 568 compcredp = compnamep->cn_cred = crdup(savecompcredp); 569 570 if (umap_bug_bypass && compcredp->cr_uid != 0) 571 printf("umap_rename: rename component credit user was %d, group %d\n", 572 compcredp->cr_uid, compcredp->cr_gid); 573 574 /* Map all ids in the credential structure. */ 575 576 umap_mapids(vp->v_mount, compcredp); 577 578 if (umap_bug_bypass && compcredp->cr_uid != 0) 579 printf("umap_rename: rename component credit user now %d, group %d\n", 580 compcredp->cr_uid, compcredp->cr_gid); 581 582 error = umap_bypass(ap); 583 584 /* Restore the additional mapped componentname cred structure. */ 585 586 crfree(compcredp); 587 compnamep->cn_cred = savecompcredp; 588 589 return error; 590 } 591