vnd.c revision 1.5
1 /* 2 * Copyright (c) 1988 University of Utah. 3 * Copyright (c) 1990, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * the Systems Programming Group of the University of Utah Computer 8 * Science Department. 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 * from: Utah $Hdr: vn.c 1.13 94/04/02$ 39 * 40 * @(#)vn.c 8.6 (Berkeley) 4/1/94 41 */ 42 43 /* 44 * Vnode disk driver. 45 * 46 * Block/character interface to a vnode. Allows one to treat a file 47 * as a disk (e.g. build a filesystem in it, mount it, etc.). 48 * 49 * NOTE 1: This uses the VOP_BMAP/VOP_STRATEGY interface to the vnode 50 * instead of a simple VOP_RDWR. We do this to avoid distorting the 51 * local buffer cache. 52 * 53 * NOTE 2: There is a security issue involved with this driver. 54 * Once mounted all access to the contents of the "mapped" file via 55 * the special file is controlled by the permissions on the special 56 * file, the protection of the mapped file is ignored (effectively, 57 * by using root credentials in all transactions). 58 * 59 * NOTE 3: Doesn't interact with leases, should it? 60 */ 61 #include "vn.h" 62 #if NVN > 0 63 64 #include <sys/param.h> 65 #include <sys/systm.h> 66 #include <sys/namei.h> 67 #include <sys/proc.h> 68 #include <sys/errno.h> 69 #include <sys/dkstat.h> 70 #include <sys/buf.h> 71 #include <sys/malloc.h> 72 #include <sys/ioctl.h> 73 #include <sys/mount.h> 74 #include <sys/vnode.h> 75 #include <sys/file.h> 76 #include <sys/uio.h> 77 78 #include <miscfs/specfs/specdev.h> 79 80 #include <dev/vnioctl.h> 81 82 #ifdef DEBUG 83 int dovncluster = 1; 84 int vndebug = 0x00; 85 #define VDB_FOLLOW 0x01 86 #define VDB_INIT 0x02 87 #define VDB_IO 0x04 88 #endif 89 90 #define b_cylin b_resid 91 92 #define vnunit(x) ((minor(x) >> 3) & 0x7) /* for consistency */ 93 94 #define getvnbuf() \ 95 ((struct buf *)malloc(sizeof(struct buf), M_DEVBUF, M_WAITOK)) 96 #define putvnbuf(bp) \ 97 free((caddr_t)(bp), M_DEVBUF) 98 99 struct vn_softc { 100 int sc_flags; /* flags */ 101 size_t sc_size; /* size of vn */ 102 struct vnode *sc_vp; /* vnode */ 103 struct ucred *sc_cred; /* credentials */ 104 int sc_maxactive; /* max # of active requests */ 105 struct buf sc_tab; /* transfer queue */ 106 }; 107 108 /* sc_flags */ 109 #define VNF_ALIVE 0x01 110 #define VNF_INITED 0x02 111 112 #if 0 /* if you need static allocation */ 113 struct vn_softc vn_softc[NVN]; 114 int numvnd = NVN; 115 #else 116 struct vn_softc *vn_softc; 117 int numvnd; 118 #endif 119 120 void 121 vnattach(num) 122 int num; 123 { 124 char *mem; 125 register u_long size; 126 127 if (num <= 0) 128 return; 129 size = num * sizeof(struct vn_softc); 130 mem = malloc(size, M_DEVBUF, M_NOWAIT); 131 if (mem == NULL) { 132 printf("WARNING: no memory for vnode disks\n"); 133 return; 134 } 135 bzero(mem, size); 136 vn_softc = (struct vn_softc *)mem; 137 numvnd = num; 138 } 139 140 int 141 vnopen(dev, flags, mode, p) 142 dev_t dev; 143 int flags, mode; 144 struct proc *p; 145 { 146 int unit = vnunit(dev); 147 148 #ifdef DEBUG 149 if (vndebug & VDB_FOLLOW) 150 printf("vnopen(%x, %x, %x, %x)\n", dev, flags, mode, p); 151 #endif 152 if (unit >= numvnd) 153 return(ENXIO); 154 return(0); 155 } 156 157 int 158 vnclose(dev, flags, mode, p) 159 dev_t dev; 160 int flags, mode; 161 struct proc *p; 162 { 163 #ifdef DEBUG 164 if (vndebug & VDB_FOLLOW) 165 printf("vnclose(%x, %x, %x, %x)\n", dev, flags, mode, p); 166 #endif 167 return 0; 168 } 169 170 /* 171 * Break the request into bsize pieces and submit using VOP_BMAP/VOP_STRATEGY. 172 * Note that this driver can only be used for swapping over NFS on the hp 173 * since nfs_strategy on the vax cannot handle u-areas and page tables. 174 */ 175 vnstrategy(bp) 176 register struct buf *bp; 177 { 178 int unit = vnunit(bp->b_dev); 179 register struct vn_softc *vn = &vn_softc[unit]; 180 register struct buf *nbp; 181 register int bn, bsize, resid; 182 register caddr_t addr; 183 int sz, flags, error; 184 extern void vniodone(); 185 186 #ifdef DEBUG 187 if (vndebug & VDB_FOLLOW) 188 printf("vnstrategy(%x): unit %d\n", bp, unit); 189 #endif 190 if ((vn->sc_flags & VNF_INITED) == 0) { 191 bp->b_error = ENXIO; 192 bp->b_flags |= B_ERROR; 193 biodone(bp); 194 return; 195 } 196 bn = bp->b_blkno; 197 sz = howmany(bp->b_bcount, DEV_BSIZE); 198 bp->b_resid = bp->b_bcount; 199 if (bn < 0 || bn + sz > vn->sc_size) { 200 if (bn != vn->sc_size) { 201 bp->b_error = EINVAL; 202 bp->b_flags |= B_ERROR; 203 } 204 biodone(bp); 205 return; 206 } 207 bn = dbtob(bn); 208 bsize = vn->sc_vp->v_mount->mnt_stat.f_iosize; 209 addr = bp->b_data; 210 flags = bp->b_flags | B_CALL; 211 for (resid = bp->b_resid; resid; resid -= sz) { 212 struct vnode *vp; 213 daddr_t nbn; 214 int off, s, nra; 215 216 nra = 0; 217 #if (BSD > 199103) 218 error = VOP_BMAP(vn->sc_vp, bn / bsize, &vp, &nbn, &nra); 219 #else 220 error = VOP_BMAP(vn->sc_vp, bn / bsize, &vp, &nbn); 221 #endif 222 if (error == 0 && (long)nbn == -1) 223 error = EIO; 224 #ifdef DEBUG 225 if (!dovncluster) 226 nra = 0; 227 #endif 228 229 if (off = bn % bsize) 230 sz = bsize - off; 231 else 232 sz = (1 + nra) * bsize; 233 if (resid < sz) 234 sz = resid; 235 #ifdef DEBUG 236 if (vndebug & VDB_IO) 237 printf("vnstrategy: vp %x/%x bn %x/%x sz %x\n", 238 vn->sc_vp, vp, bn, nbn, sz); 239 #endif 240 241 nbp = getvnbuf(); 242 nbp->b_flags = flags; 243 nbp->b_bcount = sz; 244 nbp->b_bufsize = bp->b_bufsize; 245 nbp->b_error = 0; 246 if (vp->v_type == VBLK || vp->v_type == VCHR) 247 nbp->b_dev = vp->v_rdev; 248 else 249 nbp->b_dev = NODEV; 250 nbp->b_data = addr; 251 nbp->b_blkno = nbn + btodb(off); 252 nbp->b_proc = bp->b_proc; 253 nbp->b_iodone = vniodone; 254 nbp->b_vp = vp; 255 nbp->b_pfcent = (int) bp; /* XXX */ 256 nbp->b_rcred = vn->sc_cred; /* XXX crdup? */ 257 nbp->b_wcred = vn->sc_cred; /* XXX crdup? */ 258 nbp->b_dirtyoff = bp->b_dirtyoff; 259 nbp->b_dirtyend = bp->b_dirtyend; 260 nbp->b_validoff = bp->b_validoff; 261 nbp->b_validend = bp->b_validend; 262 /* 263 * If there was an error or a hole in the file...punt. 264 * Note that we deal with this after the nbp allocation. 265 * This ensures that we properly clean up any operations 266 * that we have already fired off. 267 * 268 * XXX we could deal with holes here but it would be 269 * a hassle (in the write case). 270 */ 271 if (error) { 272 nbp->b_error = error; 273 nbp->b_flags |= B_ERROR; 274 bp->b_resid -= (resid - sz); 275 biodone(nbp); 276 return; 277 } 278 /* 279 * Just sort by block number 280 */ 281 nbp->b_cylin = nbp->b_blkno; 282 s = splbio(); 283 disksort(&vn->sc_tab, nbp); 284 if (vn->sc_tab.b_active < vn->sc_maxactive) { 285 vn->sc_tab.b_active++; 286 vnstart(vn); 287 } 288 splx(s); 289 bn += sz; 290 addr += sz; 291 } 292 } 293 294 /* 295 * Feed requests sequentially. 296 * We do it this way to keep from flooding NFS servers if we are connected 297 * to an NFS file. This places the burden on the client rather than the 298 * server. 299 */ 300 vnstart(vn) 301 register struct vn_softc *vn; 302 { 303 register struct buf *bp; 304 305 /* 306 * Dequeue now since lower level strategy routine might 307 * queue using same links 308 */ 309 bp = vn->sc_tab.b_actf; 310 vn->sc_tab.b_actf = bp->b_actf; 311 #ifdef DEBUG 312 if (vndebug & VDB_IO) 313 printf("vnstart(%d): bp %x vp %x blkno %x addr %x cnt %x\n", 314 vn-vn_softc, bp, bp->b_vp, bp->b_blkno, bp->b_data, 315 bp->b_bcount); 316 #endif 317 if ((bp->b_flags & B_READ) == 0) 318 bp->b_vp->v_numoutput++; 319 VOP_STRATEGY(bp); 320 } 321 322 void 323 vniodone(bp) 324 register struct buf *bp; 325 { 326 register struct buf *pbp = (struct buf *)bp->b_pfcent; /* XXX */ 327 register struct vn_softc *vn = &vn_softc[vnunit(pbp->b_dev)]; 328 int s; 329 330 s = splbio(); 331 #ifdef DEBUG 332 if (vndebug & VDB_IO) 333 printf("vniodone(%d): bp %x vp %x blkno %x addr %x cnt %x\n", 334 vn-vn_softc, bp, bp->b_vp, bp->b_blkno, bp->b_data, 335 bp->b_bcount); 336 #endif 337 if (bp->b_error) { 338 #ifdef DEBUG 339 if (vndebug & VDB_IO) 340 printf("vniodone: bp %x error %d\n", bp, bp->b_error); 341 #endif 342 pbp->b_flags |= B_ERROR; 343 pbp->b_error = biowait(bp); 344 } 345 pbp->b_resid -= bp->b_bcount; 346 putvnbuf(bp); 347 if (pbp->b_resid == 0) { 348 #ifdef DEBUG 349 if (vndebug & VDB_IO) 350 printf("vniodone: pbp %x iodone\n", pbp); 351 #endif 352 biodone(pbp); 353 } 354 if (vn->sc_tab.b_actf) 355 vnstart(vn); 356 else 357 vn->sc_tab.b_active--; 358 splx(s); 359 } 360 361 vnread(dev, uio, flags, p) 362 dev_t dev; 363 struct uio *uio; 364 int flags; 365 struct proc *p; 366 { 367 368 #ifdef DEBUG 369 if (vndebug & VDB_FOLLOW) 370 printf("vnread(%x, %x, %x, %x)\n", dev, uio, flags, p); 371 #endif 372 return(physio(vnstrategy, NULL, dev, B_READ, minphys, uio)); 373 } 374 375 vnwrite(dev, uio, flags, p) 376 dev_t dev; 377 struct uio *uio; 378 int flags; 379 struct proc *p; 380 { 381 382 #ifdef DEBUG 383 if (vndebug & VDB_FOLLOW) 384 printf("vnwrite(%x, %x, %x, %x)\n", dev, uio, flags, p); 385 #endif 386 return(physio(vnstrategy, NULL, dev, B_WRITE, minphys, uio)); 387 } 388 389 /* ARGSUSED */ 390 vnioctl(dev, cmd, data, flag, p) 391 dev_t dev; 392 u_long cmd; 393 caddr_t data; 394 int flag; 395 struct proc *p; 396 { 397 int unit = vnunit(dev); 398 register struct vn_softc *vn; 399 struct vn_ioctl *vio; 400 struct vattr vattr; 401 struct nameidata nd; 402 int error; 403 404 #ifdef DEBUG 405 if (vndebug & VDB_FOLLOW) 406 printf("vnioctl(%x, %x, %x, %x, %x): unit %d\n", 407 dev, cmd, data, flag, p, unit); 408 #endif 409 error = suser(p->p_ucred, &p->p_acflag); 410 if (error) 411 return (error); 412 if (unit >= numvnd) 413 return (ENXIO); 414 415 vn = &vn_softc[unit]; 416 vio = (struct vn_ioctl *)data; 417 switch (cmd) { 418 419 case VNIOCSET: 420 if (vn->sc_flags & VNF_INITED) 421 return(EBUSY); 422 /* 423 * Always open for read and write. 424 * This is probably bogus, but it lets vn_open() 425 * weed out directories, sockets, etc. so we don't 426 * have to worry about them. 427 */ 428 #if (BSD > 199103) 429 NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, vio->vn_file, p); 430 if (error = vn_open(&nd, FREAD|FWRITE, 0)) 431 return(error); 432 #else 433 nd.ni_nameiop = LOOKUP | FOLLOW; 434 nd.ni_segflg = UIO_USERSPACE; 435 nd.ni_dirp = vio->vn_file; 436 if (error = vn_open(&nd, p, FREAD|FWRITE, 0)) 437 return(error); 438 #endif 439 if (error = VOP_GETATTR(nd.ni_vp, &vattr, p->p_ucred, p)) { 440 VOP_UNLOCK(nd.ni_vp); 441 (void) vn_close(nd.ni_vp, FREAD|FWRITE, p->p_ucred, p); 442 return(error); 443 } 444 VOP_UNLOCK(nd.ni_vp); 445 vn->sc_vp = nd.ni_vp; 446 vn->sc_size = btodb(vattr.va_size); /* note truncation */ 447 if (error = vnsetcred(vn, p->p_ucred)) { 448 (void) vn_close(nd.ni_vp, FREAD|FWRITE, p->p_ucred, p); 449 return(error); 450 } 451 vnthrottle(vn, vn->sc_vp); 452 vio->vn_size = dbtob(vn->sc_size); 453 vn->sc_flags |= VNF_INITED; 454 #ifdef DEBUG 455 if (vndebug & VDB_INIT) 456 printf("vnioctl: SET vp %x size %x\n", 457 vn->sc_vp, vn->sc_size); 458 #endif 459 break; 460 461 case VNIOCCLR: 462 if ((vn->sc_flags & VNF_INITED) == 0) 463 return(ENXIO); 464 vnclear(vn); 465 #ifdef DEBUG 466 if (vndebug & VDB_INIT) 467 printf("vnioctl: CLRed\n"); 468 #endif 469 break; 470 471 default: 472 return(ENXIO); 473 } 474 return(0); 475 } 476 477 /* 478 * Duplicate the current processes' credentials. Since we are called only 479 * as the result of a SET ioctl and only root can do that, any future access 480 * to this "disk" is essentially as root. Note that credentials may change 481 * if some other uid can write directly to the mapped file (NFS). 482 */ 483 vnsetcred(vn, cred) 484 register struct vn_softc *vn; 485 struct ucred *cred; 486 { 487 struct uio auio; 488 struct iovec aiov; 489 char *tmpbuf; 490 int error; 491 492 vn->sc_cred = crdup(cred); 493 tmpbuf = malloc(DEV_BSIZE, M_TEMP, M_WAITOK); 494 495 /* XXX: Horrible kludge to establish credentials for NFS */ 496 aiov.iov_base = tmpbuf; 497 aiov.iov_len = min(DEV_BSIZE, dbtob(vn->sc_size)); 498 auio.uio_iov = &aiov; 499 auio.uio_iovcnt = 1; 500 auio.uio_offset = 0; 501 auio.uio_rw = UIO_READ; 502 auio.uio_segflg = UIO_SYSSPACE; 503 auio.uio_resid = aiov.iov_len; 504 error = VOP_READ(vn->sc_vp, &auio, 0, vn->sc_cred); 505 506 free(tmpbuf, M_TEMP); 507 return (error); 508 } 509 510 /* 511 * Set maxactive based on FS type 512 */ 513 vnthrottle(vn, vp) 514 register struct vn_softc *vn; 515 struct vnode *vp; 516 { 517 #ifdef NFSCLIENT 518 #if (BSD > 199103) 519 extern int (**nfsv2_vnodeop_p)(); 520 521 if (vp->v_op == nfsv2_vnodeop_p) 522 #else 523 extern struct vnodeops nfsv2_vnodeops; 524 525 if (vp->v_op == &nfsv2_vnodeops) 526 #endif 527 vn->sc_maxactive = 2; 528 else 529 #endif 530 vn->sc_maxactive = 8; 531 532 if (vn->sc_maxactive < 1) 533 vn->sc_maxactive = 1; 534 } 535 536 vnshutdown() 537 { 538 register struct vn_softc *vn; 539 540 for (vn = &vn_softc[0]; vn < &vn_softc[numvnd]; vn++) 541 if (vn->sc_flags & VNF_INITED) 542 vnclear(vn); 543 } 544 545 vnclear(vn) 546 register struct vn_softc *vn; 547 { 548 register struct vnode *vp = vn->sc_vp; 549 struct proc *p = curproc; /* XXX */ 550 551 #ifdef DEBUG 552 if (vndebug & VDB_FOLLOW) 553 printf("vnclear(%x): vp %x\n", vp); 554 #endif 555 vn->sc_flags &= ~VNF_INITED; 556 if (vp == (struct vnode *)0) 557 panic("vnioctl: null vp"); 558 (void) vn_close(vp, FREAD|FWRITE, vn->sc_cred, p); 559 crfree(vn->sc_cred); 560 vn->sc_vp = (struct vnode *)0; 561 vn->sc_cred = (struct ucred *)0; 562 vn->sc_size = 0; 563 } 564 565 vnsize(dev) 566 dev_t dev; 567 { 568 int unit = vnunit(dev); 569 register struct vn_softc *vn = &vn_softc[unit]; 570 571 if (unit >= numvnd || (vn->sc_flags & VNF_INITED) == 0) 572 return(-1); 573 return(vn->sc_size); 574 } 575 576 vndump(dev) 577 { 578 return(ENXIO); 579 } 580 #endif 581
Indexes created Mon Sep 29 21:09:56 GMT 2025