sys/vfs/umapfs/umap_vnops.c

   1 /*
   2  * Copyright (c) 1992, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * This code is derived from software donated to Berkeley by
   6  * the UCLA Ficus project.
   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  *      @(#)umap_vnops.c        8.6 (Berkeley) 5/22/95
  37  * $FreeBSD: src/sys/miscfs/umapfs/umap_vnops.c,v 1.30 1999/08/30 07:08:04 bde Exp $
  38  * $DragonFly: src/sys/vfs/umapfs/Attic/umap_vnops.c,v 1.9 2004/08/13 17:51:14 dillon Exp $
  39  */
  40
  41 /*
  42  * Umap Layer
  43  */
  44
  45 #include <sys/param.h>
  46 #include <sys/systm.h>
  47 #include <sys/kernel.h>
  48 #include <sys/sysctl.h>
  49 #include <sys/vnode.h>
  50 #include <sys/mount.h>
  51 #include <sys/proc.h>
  52 #include <sys/namei.h>
  53 #include <sys/malloc.h>
  54 #include <sys/buf.h>
  55 #include "umap.h"
  56 #include <vfs/nullfs/null.h>
  57
  58 static int umap_bug_bypass = 0;   /* for debugging: enables bypass printf'ing */
  59 SYSCTL_INT(_debug, OID_AUTO, umapfs_bug_bypass, CTLFLAG_RW,
  60         &umap_bug_bypass, 0, "");
  61
  62 static int      umap_bypass (struct vop_generic_args *ap);
  63 static int      umap_getattr (struct vop_getattr_args *ap);
  64 static int      umap_inactive (struct vop_inactive_args *ap);
  65 static int      umap_lock (struct vop_lock_args *ap);
  66 static int      umap_print (struct vop_print_args *ap);
  67 static int      umap_reclaim (struct vop_reclaim_args *ap);
  68 static int      umap_rename (struct vop_rename_args *ap);
  69 static int      umap_unlock (struct vop_unlock_args *ap);
  70
  71 /*
  72  * This is the 10-Apr-92 bypass routine.
  73  * See null_vnops.c:null_bypass for more details.
  74  *
  75  * umap_bypass(struct vnodeop_desc *a_desc, ...)
  76  */
  77 static int
  78 umap_bypass(struct vop_generic_args *ap)
  79 {
  80         struct ucred **credpp = 0, *credp = 0;
  81         struct ucred *savecredp = 0, *savecompcredp = 0;
  82         struct ucred *compcredp = 0;
  83         struct vnode **this_vp_p;
  84         int error;
  85         struct vnode *old_vps[VDESC_MAX_VPS];
  86         struct vnode *vp1 = 0;
  87         struct vnode **vps_p[VDESC_MAX_VPS];
  88         struct vnode ***vppp;
  89         struct vnodeop_desc *descp = ap->a_desc;
  90         int reles, i;
  91         struct componentname **compnamepp = 0;
  92
  93         if (umap_bug_bypass)
  94                 printf ("umap_bypass: %s\n", descp->vdesc_name);
  95
  96 #ifdef DIAGNOSTIC
  97         /*
  98          * We require at least one vp.
  99          */
 100         if (descp->vdesc_vp_offsets == NULL ||
 101             descp->vdesc_vp_offsets[0] == VDESC_NO_OFFSET)
 102                 panic ("umap_bypass: no vp's in map");
 103 #endif
 104
 105         /*
 106          * Map the vnodes going in.
 107          * Later, we'll invoke the operation based on
 108          * the first mapped vnode's operation vector.
 109          */
 110         reles = descp->vdesc_flags;
 111         for (i = 0; i < VDESC_MAX_VPS; reles >>= 1, i++) {
 112                 if (descp->vdesc_vp_offsets[i] == VDESC_NO_OFFSET)
 113                         break;   /* bail out at end of list */
 114                 vps_p[i] = this_vp_p =
 115                         VOPARG_OFFSETTO(struct vnode**, descp->vdesc_vp_offsets[i], ap);
 116
 117                 if (i == 0) {
 118                         vp1 = *vps_p[0];
 119                 }
 120
 121                 /*
 122                  * We're not guaranteed that any but the first vnode
 123                  * are of our type.  Check for and don't map any
 124                  * that aren't.  (Must map first vp or vclean fails.)
 125                  */
 126
 127                 if (i && (*this_vp_p)->v_vops != umap_vnode_vops) {
 128                         old_vps[i] = NULL;
 129                 } else {
 130                         old_vps[i] = *this_vp_p;
 131                         *(vps_p[i]) = UMAPVPTOLOWERVP(*this_vp_p);
 132                         if (reles & 1)
 133                                 vref(*this_vp_p);
 134                 }
 135
 136         }
 137
 138         /*
 139          * Fix the credentials.  (That's the purpose of this layer.)
 140          */
 141
 142         if (descp->vdesc_cred_offset != VDESC_NO_OFFSET) {
 143
 144                 credpp = VOPARG_OFFSETTO(struct ucred**,
 145                     descp->vdesc_cred_offset, ap);
 146
 147                 /* Save old values */
 148
 149                 savecredp = (*credpp);
 150                 if (savecredp != NOCRED)
 151                         (*credpp) = crdup(savecredp);
 152                 credp = *credpp;
 153
 154                 if (umap_bug_bypass && credp->cr_uid != 0)
 155                         printf("umap_bypass: user was %lu, group %lu\n",
 156                             (u_long)credp->cr_uid, (u_long)credp->cr_gid);
 157
 158                 /* Map all ids in the credential structure. */
 159
 160                 umap_mapids(vp1->v_mount, credp);
 161
 162                 if (umap_bug_bypass && credp->cr_uid != 0)
 163                         printf("umap_bypass: user now %lu, group %lu\n",
 164                             (u_long)credp->cr_uid, (u_long)credp->cr_gid);
 165         }
 166
 167         /* BSD often keeps a credential in the componentname structure
 168          * for speed.  If there is one, it better get mapped, too.
 169          */
 170
 171         if (descp->vdesc_componentname_offset != VDESC_NO_OFFSET) {
 172
 173                 compnamepp = VOPARG_OFFSETTO(struct componentname**,
 174                     descp->vdesc_componentname_offset, ap);
 175
 176                 compcredp = (*compnamepp)->cn_cred;
 177                 savecompcredp = compcredp;
 178                 if (savecompcredp != NOCRED)
 179                         (*compnamepp)->cn_cred = crdup(savecompcredp);
 180                 compcredp = (*compnamepp)->cn_cred;
 181
 182                 if (umap_bug_bypass && compcredp->cr_uid != 0)
 183                         printf(
 184                     "umap_bypass: component credit user was %lu, group %lu\n",
 185                             (u_long)compcredp->cr_uid,
 186                             (u_long)compcredp->cr_gid);
 187
 188                 /* Map all ids in the credential structure. */
 189
 190                 umap_mapids(vp1->v_mount, compcredp);
 191
 192                 if (umap_bug_bypass && compcredp->cr_uid != 0)
 193                         printf(
 194                     "umap_bypass: component credit user now %lu, group %lu\n",
 195                             (u_long)compcredp->cr_uid,
 196                             (u_long)compcredp->cr_gid);
 197         }
 198
 199         /*
 200          * Call the operation on the lower layer
 201          * with the modified argument structure.
 202          */
 203         error = VCALL(*(vps_p[0]), descp->vdesc_offset, ap);
 204
 205         /*
 206          * Maintain the illusion of call-by-value
 207          * by restoring vnodes in the argument structure
 208          * to their original value.
 209          */
 210         reles = descp->vdesc_flags;
 211         for (i = 0; i < VDESC_MAX_VPS; reles >>= 1, i++) {
 212                 if (descp->vdesc_vp_offsets[i] == VDESC_NO_OFFSET)
 213                         break;   /* bail out at end of list */
 214                 if (old_vps[i]) {
 215                         *(vps_p[i]) = old_vps[i];
 216                         if (reles & 1)
 217                                 vrele(*(vps_p[i]));
 218                 };
 219         };
 220
 221         /*
 222          * Map the possible out-going vpp
 223          * (Assumes that the lower layer always returns
 224          * a vref'ed vpp unless it gets an error.)
 225          */
 226         if (descp->vdesc_vpp_offset != VDESC_NO_OFFSET &&
 227             !(descp->vdesc_flags & VDESC_NOMAP_VPP) &&
 228             !error) {
 229                 if (descp->vdesc_flags & VDESC_VPP_WILLRELE)
 230                         goto out;
 231                 vppp = VOPARG_OFFSETTO(struct vnode***,
 232                                  descp->vdesc_vpp_offset, ap);
 233                 if (*vppp)
 234                         error = umap_node_create(old_vps[0]->v_mount, **vppp, *vppp);
 235         };
 236
 237  out:
 238         /*
 239          * Free duplicate cred structure and restore old one.
 240          */
 241         if (descp->vdesc_cred_offset != VDESC_NO_OFFSET) {
 242                 if (umap_bug_bypass && credp && credp->cr_uid != 0)
 243                         printf("umap_bypass: returning-user was %lu\n",
 244                             (u_long)credp->cr_uid);
 245
 246                 if (savecredp != NOCRED) {
 247                         crfree(credp);
 248                         (*credpp) = savecredp;
 249                         if (umap_bug_bypass && credpp && (*credpp)->cr_uid != 0)
 250                                 printf(
 251                                     "umap_bypass: returning-user now %lu\n\n",
 252                                     (u_long)(*credpp)->cr_uid);
 253                 }
 254         }
 255
 256         if (descp->vdesc_componentname_offset != VDESC_NO_OFFSET) {
 257                 if (umap_bug_bypass && compcredp && compcredp->cr_uid != 0)
 258                         printf(
 259                             "umap_bypass: returning-component-user was %lu\n",
 260                             (u_long)compcredp->cr_uid);
 261
 262                 if (savecompcredp != NOCRED) {
 263                         crfree(compcredp);
 264                         (*compnamepp)->cn_cred = savecompcredp;
 265                         if (umap_bug_bypass && credpp && (*credpp)->cr_uid != 0)
 266                                 printf(
 267                             "umap_bypass: returning-component-user now %lu\n",
 268                                     (u_long)compcredp->cr_uid);
 269                 }
 270         }
 271
 272         return (error);
 273 }
 274
 275
 276 /*
 277  *  We handle getattr to change the fsid.
 278  *
 279  * umap_getattr(struct vnode *a_vp, struct vattr *a_vap, struct ucred *a_cred,
 280  *              struct thread *a_td)
 281  */
 282 static int
 283 umap_getattr(struct vop_getattr_args *ap)
 284 {
 285         short uid, gid;
 286         int error, tmpid, nentries, gnentries;
 287         u_long (*mapdata)[2], (*gmapdata)[2];
 288         struct vnode **vp1p;
 289         struct vnodeop_desc *descp = ap->a_head.a_desc;
 290
 291         error = umap_bypass(&ap->a_head);
 292         if (error)
 293                 return (error);
 294
 295         /*
 296          * Umap needs to map the uid and gid returned by a stat
 297          * into the proper values for this site.  This involves
 298          * finding the returned uid in the mapping information,
 299          * translating it into the uid on the other end,
 300          * and filling in the proper field in the vattr
 301          * structure pointed to by ap->a_vap.  The group
 302          * is easier, since currently all groups will be
 303          * translate to the NULLGROUP.
 304          */
 305
 306         /* Find entry in map */
 307
 308         uid = ap->a_vap->va_uid;
 309         gid = ap->a_vap->va_gid;
 310         if (umap_bug_bypass)
 311                 printf("umap_getattr: mapped uid = %d, mapped gid = %d\n", uid,
 312                     gid);
 313
 314         vp1p = VOPARG_OFFSETTO(struct vnode**, descp->vdesc_vp_offsets[0], ap);
 315         nentries =  MOUNTTOUMAPMOUNT((*vp1p)->v_mount)->info_nentries;
 316         mapdata =  (MOUNTTOUMAPMOUNT((*vp1p)->v_mount)->info_mapdata);
 317         gnentries =  MOUNTTOUMAPMOUNT((*vp1p)->v_mount)->info_gnentries;
 318         gmapdata =  (MOUNTTOUMAPMOUNT((*vp1p)->v_mount)->info_gmapdata);
 319
 320         /* Reverse map the uid for the vnode.  Since it's a reverse
 321                 map, we can't use umap_mapids() to do it. */
 322
 323         tmpid = umap_reverse_findid(uid, mapdata, nentries);
 324
 325         if (tmpid != -1) {
 326
 327                 ap->a_vap->va_uid = (uid_t) tmpid;
 328                 if (umap_bug_bypass)
 329                         printf("umap_getattr: original uid = %d\n", uid);
 330         } else
 331                 ap->a_vap->va_uid = (uid_t) NOBODY;
 332
 333         /* Reverse map the gid for the vnode. */
 334
 335         tmpid = umap_reverse_findid(gid, gmapdata, gnentries);
 336
 337         if (tmpid != -1) {
 338
 339                 ap->a_vap->va_gid = (gid_t) tmpid;
 340                 if (umap_bug_bypass)
 341                         printf("umap_getattr: original gid = %d\n", gid);
 342         } else
 343                 ap->a_vap->va_gid = (gid_t) NULLGROUP;
 344
 345         return (0);
 346 }
 347
 348 /*
 349  * We need to process our own vnode lock and then clear the
 350  * interlock flag as it applies only to our vnode, not the
 351  * vnodes below us on the stack.
 352  *
 353  * umap_lock(struct vnode *a_vp, lwkt_tokref_t a_vlock, int a_flags,
 354  *           struct thread *a_td)
 355  */
 356 static int
 357 umap_lock(struct vop_lock_args *ap)
 358 {
 359         vop_nolock(ap);
 360         if ((ap->a_flags & LK_TYPE_MASK) == LK_DRAIN)
 361                 return (0);
 362         ap->a_flags &= ~LK_INTERLOCK;
 363         return (null_bypass(&ap->a_head));
 364 }
 365
 366 /*
 367  * We need to process our own vnode unlock and then clear the
 368  * interlock flag as it applies only to our vnode, not the
 369  * vnodes below us on the stack.
 370  *
 371  * umap_unlock(struct vnode *a_vp, int a_flags, struct thread *a_td)
 372  */
 373 int
 374 umap_unlock(struct vop_unlock_args *ap)
 375 {
 376         vop_nounlock(ap);
 377         ap->a_flags &= ~LK_INTERLOCK;
 378         return (null_bypass(&ap->a_head));
 379 }
 380
 381 /*
 382  * umap_inactive(struct vnode *a_vp, struct thread *a_td)
 383  */
 384 static int
 385 umap_inactive(struct vop_inactive_args *ap)
 386 {
 387         struct vnode *vp = ap->a_vp;
 388         struct umap_node *xp = VTOUMAP(vp);
 389         struct vnode *lowervp = xp->umap_lowervp;
 390         /*
 391          * Do nothing (and _don't_ bypass).
 392          * Wait to vrele lowervp until reclaim,
 393          * so that until then our umap_node is in the
 394          * cache and reusable.
 395          *
 396          */
 397         VOP_INACTIVE(lowervp, ap->a_td);
 398         VOP_UNLOCK(ap->a_vp, NULL, 0, ap->a_td);
 399         return (0);
 400 }
 401
 402 /*
 403  * umap_reclaim(struct vnode *a_vp)
 404  */
 405 static int
 406 umap_reclaim(struct vop_reclaim_args *ap)
 407 {
 408         struct vnode *vp = ap->a_vp;
 409         struct umap_node *xp = VTOUMAP(vp);
 410         struct vnode *lowervp = xp->umap_lowervp;
 411
 412         /* After this assignment, this node will not be re-used. */
 413         xp->umap_lowervp = NULL;
 414         LIST_REMOVE(xp, umap_hash);
 415         FREE(vp->v_data, M_TEMP);
 416         vp->v_data = NULL;
 417         vrele(lowervp);
 418         return (0);
 419 }
 420
 421 /*
 422  * umap_print(struct vop_print_args *ap)
 423  */
 424 static int
 425 umap_print(struct vop_print_args *ap)
 426 {
 427         struct vnode *vp = ap->a_vp;
 428         printf("\ttag VT_UMAPFS, vp=%p, lowervp=%p\n", vp, UMAPVPTOLOWERVP(vp));
 429         return (0);
 430 }
 431
 432 /*
 433  * umap_rename(struct vnode *a_fdvp, struct vnode *a_fvp,
 434  *              struct componentname *a_fcnp, struct vnode *a_tdvp,
 435  *              struct vnode *a_tvp, struct componentname *a_tcnp)
 436  */
 437 static int
 438 umap_rename(struct vop_rename_args *ap)
 439 {
 440         int error;
 441         struct componentname *compnamep;
 442         struct ucred *compcredp, *savecompcredp;
 443         struct vnode *vp;
 444
 445         /*
 446          * Rename is irregular, having two componentname structures.
 447          * We need to map the cre in the second structure,
 448          * and then bypass takes care of the rest.
 449          */
 450
 451         vp = ap->a_fdvp;
 452         compnamep = ap->a_tcnp;
 453         compcredp = compnamep->cn_cred;
 454
 455         savecompcredp = compcredp;
 456         compcredp = compnamep->cn_cred = crdup(savecompcredp);
 457
 458         if (umap_bug_bypass && compcredp->cr_uid != 0)
 459                 printf(
 460             "umap_rename: rename component credit user was %lu, group %lu\n",
 461                     (u_long)compcredp->cr_uid, (u_long)compcredp->cr_gid);
 462
 463         /* Map all ids in the credential structure. */
 464
 465         umap_mapids(vp->v_mount, compcredp);
 466
 467         if (umap_bug_bypass && compcredp->cr_uid != 0)
 468                 printf(
 469             "umap_rename: rename component credit user now %lu, group %lu\n",
 470                     (u_long)compcredp->cr_uid, (u_long)compcredp->cr_gid);
 471
 472         error = umap_bypass(&ap->a_head);
 473
 474         /* Restore the additional mapped componentname cred structure. */
 475
 476         crfree(compcredp);
 477         compnamep->cn_cred = savecompcredp;
 478
 479         return error;
 480 }
 481
 482 /*
 483  * Global vfs data structures
 484  */
 485 /*
 486  * XXX - strategy, bwrite are hand coded currently.  They should
 487  * go away with a merged buffer/block cache.
 488  *
 489  */
 490 struct vop_ops *umap_vnode_vops;
 491 static struct vnodeopv_entry_desc umap_vnodeop_entries[] = {
 492         { &vop_default_desc,            (void *) umap_bypass },
 493         { &vop_getattr_desc,            (void *) umap_getattr },
 494         { &vop_inactive_desc,           (void *) umap_inactive },
 495         { &vop_lock_desc,               (void *) umap_lock },
 496         { &vop_print_desc,              (void *) umap_print },
 497         { &vop_reclaim_desc,            (void *) umap_reclaim },
 498         { &vop_rename_desc,             (void *) umap_rename },
 499         { &vop_unlock_desc,             (void *) umap_unlock },
 500         { NULL, NULL }
 501 };
 502 static struct vnodeopv_desc umap_vnodeop_opv_desc =
 503         { &umap_vnode_vops, umap_vnodeop_entries };
 504
 505 VNODEOP_SET(umap_vnodeop_opv_desc);