Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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sys/fs/devfs/devfs_vnops.c
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1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2000-2004 5 * Poul-Henning Kamp. All rights reserved. 6 * Copyright (c) 1989, 1992-1993, 1995 7 * The Regents of the University of California. All rights reserved. 8 * 9 * This code is derived from software donated to Berkeley by 10 * Jan-Simon Pendry. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)kernfs_vnops.c 8.15 (Berkeley) 5/21/95 34 * From: FreeBSD: src/sys/miscfs/kernfs/kernfs_vnops.c 1.43 35 * 36 * $FreeBSD: releng/12.0/sys/fs/devfs/devfs_vnops.c 339186 2018-10-04 23:55:03Z brooks $ 37 */ 38 39 /* 40 * TODO: 41 * mkdir: want it ? 42 */ 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/conf.h> 47 #include <sys/dirent.h> 48 #include <sys/fcntl.h> 49 #include <sys/file.h> 50 #include <sys/filedesc.h> 51 #include <sys/filio.h> 52 #include <sys/jail.h> 53 #include <sys/kernel.h> 54 #include <sys/lock.h> 55 #include <sys/malloc.h> 56 #include <sys/mman.h> 57 #include <sys/mount.h> 58 #include <sys/namei.h> 59 #include <sys/priv.h> 60 #include <sys/proc.h> 61 #include <sys/stat.h> 62 #include <sys/sx.h> 63 #include <sys/sysctl.h> 64 #include <sys/time.h> 65 #include <sys/ttycom.h> 66 #include <sys/unistd.h> 67 #include <sys/vnode.h> 68 69 static struct vop_vector devfs_vnodeops; 70 static struct vop_vector devfs_specops; 71 static struct fileops devfs_ops_f; 72 73 #include <fs/devfs/devfs.h> 74 #include <fs/devfs/devfs_int.h> 75 76 #include <security/mac/mac_framework.h> 77 78 #include <vm/vm.h> 79 #include <vm/vm_extern.h> 80 #include <vm/vm_object.h> 81 82 static MALLOC_DEFINE(M_CDEVPDATA, "DEVFSP", "Metainfo for cdev-fp data"); 83 84 struct mtx devfs_de_interlock; 85 MTX_SYSINIT(devfs_de_interlock, &devfs_de_interlock, "devfs interlock", MTX_DEF); 86 struct sx clone_drain_lock; 87 SX_SYSINIT(clone_drain_lock, &clone_drain_lock, "clone events drain lock"); 88 struct mtx cdevpriv_mtx; 89 MTX_SYSINIT(cdevpriv_mtx, &cdevpriv_mtx, "cdevpriv lock", MTX_DEF); 90 91 SYSCTL_DECL(_vfs_devfs); 92 93 static int devfs_dotimes; 94 SYSCTL_INT(_vfs_devfs, OID_AUTO, dotimes, CTLFLAG_RW, 95 &devfs_dotimes, 0, "Update timestamps on DEVFS with default precision"); 96 97 /* 98 * Update devfs node timestamp. Note that updates are unlocked and 99 * stat(2) could see partially updated times. 100 */ 101 static void 102 devfs_timestamp(struct timespec *tsp) 103 { 104 time_t ts; 105 106 if (devfs_dotimes) { 107 vfs_timestamp(tsp); 108 } else { 109 ts = time_second; 110 if (tsp->tv_sec != ts) { 111 tsp->tv_sec = ts; 112 tsp->tv_nsec = 0; 113 } 114 } 115 } 116 117 static int 118 devfs_fp_check(struct file *fp, struct cdev **devp, struct cdevsw **dswp, 119 int *ref) 120 { 121 122 *dswp = devvn_refthread(fp->f_vnode, devp, ref); 123 if (*devp != fp->f_data) { 124 if (*dswp != NULL) 125 dev_relthread(*devp, *ref); 126 return (ENXIO); 127 } 128 KASSERT((*devp)->si_refcount > 0, 129 ("devfs: un-referenced struct cdev *(%s)", devtoname(*devp))); 130 if (*dswp == NULL) 131 return (ENXIO); 132 curthread->td_fpop = fp; 133 return (0); 134 } 135 136 int 137 devfs_get_cdevpriv(void **datap) 138 { 139 struct file *fp; 140 struct cdev_privdata *p; 141 int error; 142 143 fp = curthread->td_fpop; 144 if (fp == NULL) 145 return (EBADF); 146 p = fp->f_cdevpriv; 147 if (p != NULL) { 148 error = 0; 149 *datap = p->cdpd_data; 150 } else 151 error = ENOENT; 152 return (error); 153 } 154 155 int 156 devfs_set_cdevpriv(void *priv, d_priv_dtor_t *priv_dtr) 157 { 158 struct file *fp; 159 struct cdev_priv *cdp; 160 struct cdev_privdata *p; 161 int error; 162 163 fp = curthread->td_fpop; 164 if (fp == NULL) 165 return (ENOENT); 166 cdp = cdev2priv((struct cdev *)fp->f_data); 167 p = malloc(sizeof(struct cdev_privdata), M_CDEVPDATA, M_WAITOK); 168 p->cdpd_data = priv; 169 p->cdpd_dtr = priv_dtr; 170 p->cdpd_fp = fp; 171 mtx_lock(&cdevpriv_mtx); 172 if (fp->f_cdevpriv == NULL) { 173 LIST_INSERT_HEAD(&cdp->cdp_fdpriv, p, cdpd_list); 174 fp->f_cdevpriv = p; 175 mtx_unlock(&cdevpriv_mtx); 176 error = 0; 177 } else { 178 mtx_unlock(&cdevpriv_mtx); 179 free(p, M_CDEVPDATA); 180 error = EBUSY; 181 } 182 return (error); 183 } 184 185 void 186 devfs_destroy_cdevpriv(struct cdev_privdata *p) 187 { 188 189 mtx_assert(&cdevpriv_mtx, MA_OWNED); 190 KASSERT(p->cdpd_fp->f_cdevpriv == p, 191 ("devfs_destoy_cdevpriv %p != %p", p->cdpd_fp->f_cdevpriv, p)); 192 p->cdpd_fp->f_cdevpriv = NULL; 193 LIST_REMOVE(p, cdpd_list); 194 mtx_unlock(&cdevpriv_mtx); 195 (p->cdpd_dtr)(p->cdpd_data); 196 free(p, M_CDEVPDATA); 197 } 198 199 static void 200 devfs_fpdrop(struct file *fp) 201 { 202 struct cdev_privdata *p; 203 204 mtx_lock(&cdevpriv_mtx); 205 if ((p = fp->f_cdevpriv) == NULL) { 206 mtx_unlock(&cdevpriv_mtx); 207 return; 208 } 209 devfs_destroy_cdevpriv(p); 210 } 211 212 void 213 devfs_clear_cdevpriv(void) 214 { 215 struct file *fp; 216 217 fp = curthread->td_fpop; 218 if (fp == NULL) 219 return; 220 devfs_fpdrop(fp); 221 } 222 223 /* 224 * On success devfs_populate_vp() returns with dmp->dm_lock held. 225 */ 226 static int 227 devfs_populate_vp(struct vnode *vp) 228 { 229 struct devfs_dirent *de; 230 struct devfs_mount *dmp; 231 int locked; 232 233 ASSERT_VOP_LOCKED(vp, "devfs_populate_vp"); 234 235 dmp = VFSTODEVFS(vp->v_mount); 236 locked = VOP_ISLOCKED(vp); 237 238 sx_xlock(&dmp->dm_lock); 239 DEVFS_DMP_HOLD(dmp); 240 241 /* Can't call devfs_populate() with the vnode lock held. */ 242 VOP_UNLOCK(vp, 0); 243 devfs_populate(dmp); 244 245 sx_xunlock(&dmp->dm_lock); 246 vn_lock(vp, locked | LK_RETRY); 247 sx_xlock(&dmp->dm_lock); 248 if (DEVFS_DMP_DROP(dmp)) { 249 sx_xunlock(&dmp->dm_lock); 250 devfs_unmount_final(dmp); 251 return (ERESTART); 252 } 253 if ((vp->v_iflag & VI_DOOMED) != 0) { 254 sx_xunlock(&dmp->dm_lock); 255 return (ERESTART); 256 } 257 de = vp->v_data; 258 KASSERT(de != NULL, 259 ("devfs_populate_vp: vp->v_data == NULL but vnode not doomed")); 260 if ((de->de_flags & DE_DOOMED) != 0) { 261 sx_xunlock(&dmp->dm_lock); 262 return (ERESTART); 263 } 264 265 return (0); 266 } 267 268 static int 269 devfs_vptocnp(struct vop_vptocnp_args *ap) 270 { 271 struct vnode *vp = ap->a_vp; 272 struct vnode **dvp = ap->a_vpp; 273 struct devfs_mount *dmp; 274 char *buf = ap->a_buf; 275 int *buflen = ap->a_buflen; 276 struct devfs_dirent *dd, *de; 277 int i, error; 278 279 dmp = VFSTODEVFS(vp->v_mount); 280 281 error = devfs_populate_vp(vp); 282 if (error != 0) 283 return (error); 284 285 i = *buflen; 286 dd = vp->v_data; 287 288 if (vp->v_type == VCHR) { 289 i -= strlen(dd->de_cdp->cdp_c.si_name); 290 if (i < 0) { 291 error = ENOMEM; 292 goto finished; 293 } 294 bcopy(dd->de_cdp->cdp_c.si_name, buf + i, 295 strlen(dd->de_cdp->cdp_c.si_name)); 296 de = dd->de_dir; 297 } else if (vp->v_type == VDIR) { 298 if (dd == dmp->dm_rootdir) { 299 *dvp = vp; 300 vref(*dvp); 301 goto finished; 302 } 303 i -= dd->de_dirent->d_namlen; 304 if (i < 0) { 305 error = ENOMEM; 306 goto finished; 307 } 308 bcopy(dd->de_dirent->d_name, buf + i, 309 dd->de_dirent->d_namlen); 310 de = dd; 311 } else { 312 error = ENOENT; 313 goto finished; 314 } 315 *buflen = i; 316 de = devfs_parent_dirent(de); 317 if (de == NULL) { 318 error = ENOENT; 319 goto finished; 320 } 321 mtx_lock(&devfs_de_interlock); 322 *dvp = de->de_vnode; 323 if (*dvp != NULL) { 324 VI_LOCK(*dvp); 325 mtx_unlock(&devfs_de_interlock); 326 vholdl(*dvp); 327 VI_UNLOCK(*dvp); 328 vref(*dvp); 329 vdrop(*dvp); 330 } else { 331 mtx_unlock(&devfs_de_interlock); 332 error = ENOENT; 333 } 334 finished: 335 sx_xunlock(&dmp->dm_lock); 336 return (error); 337 } 338 339 /* 340 * Construct the fully qualified path name relative to the mountpoint. 341 * If a NULL cnp is provided, no '/' is appended to the resulting path. 342 */ 343 char * 344 devfs_fqpn(char *buf, struct devfs_mount *dmp, struct devfs_dirent *dd, 345 struct componentname *cnp) 346 { 347 int i; 348 struct devfs_dirent *de; 349 350 sx_assert(&dmp->dm_lock, SA_LOCKED); 351 352 i = SPECNAMELEN; 353 buf[i] = '\0'; 354 if (cnp != NULL) 355 i -= cnp->cn_namelen; 356 if (i < 0) 357 return (NULL); 358 if (cnp != NULL) 359 bcopy(cnp->cn_nameptr, buf + i, cnp->cn_namelen); 360 de = dd; 361 while (de != dmp->dm_rootdir) { 362 if (cnp != NULL || i < SPECNAMELEN) { 363 i--; 364 if (i < 0) 365 return (NULL); 366 buf[i] = '/'; 367 } 368 i -= de->de_dirent->d_namlen; 369 if (i < 0) 370 return (NULL); 371 bcopy(de->de_dirent->d_name, buf + i, 372 de->de_dirent->d_namlen); 373 de = devfs_parent_dirent(de); 374 if (de == NULL) 375 return (NULL); 376 } 377 return (buf + i); 378 } 379 380 static int 381 devfs_allocv_drop_refs(int drop_dm_lock, struct devfs_mount *dmp, 382 struct devfs_dirent *de) 383 { 384 int not_found; 385 386 not_found = 0; 387 if (de->de_flags & DE_DOOMED) 388 not_found = 1; 389 if (DEVFS_DE_DROP(de)) { 390 KASSERT(not_found == 1, ("DEVFS de dropped but not doomed")); 391 devfs_dirent_free(de); 392 } 393 if (DEVFS_DMP_DROP(dmp)) { 394 KASSERT(not_found == 1, 395 ("DEVFS mount struct freed before dirent")); 396 not_found = 2; 397 sx_xunlock(&dmp->dm_lock); 398 devfs_unmount_final(dmp); 399 } 400 if (not_found == 1 || (drop_dm_lock && not_found != 2)) 401 sx_unlock(&dmp->dm_lock); 402 return (not_found); 403 } 404 405 static void 406 devfs_insmntque_dtr(struct vnode *vp, void *arg) 407 { 408 struct devfs_dirent *de; 409 410 de = (struct devfs_dirent *)arg; 411 mtx_lock(&devfs_de_interlock); 412 vp->v_data = NULL; 413 de->de_vnode = NULL; 414 mtx_unlock(&devfs_de_interlock); 415 vgone(vp); 416 vput(vp); 417 } 418 419 /* 420 * devfs_allocv shall be entered with dmp->dm_lock held, and it drops 421 * it on return. 422 */ 423 int 424 devfs_allocv(struct devfs_dirent *de, struct mount *mp, int lockmode, 425 struct vnode **vpp) 426 { 427 int error; 428 struct vnode *vp; 429 struct cdev *dev; 430 struct devfs_mount *dmp; 431 struct cdevsw *dsw; 432 433 dmp = VFSTODEVFS(mp); 434 if (de->de_flags & DE_DOOMED) { 435 sx_xunlock(&dmp->dm_lock); 436 return (ENOENT); 437 } 438 loop: 439 DEVFS_DE_HOLD(de); 440 DEVFS_DMP_HOLD(dmp); 441 mtx_lock(&devfs_de_interlock); 442 vp = de->de_vnode; 443 if (vp != NULL) { 444 VI_LOCK(vp); 445 mtx_unlock(&devfs_de_interlock); 446 sx_xunlock(&dmp->dm_lock); 447 vget(vp, lockmode | LK_INTERLOCK | LK_RETRY, curthread); 448 sx_xlock(&dmp->dm_lock); 449 if (devfs_allocv_drop_refs(0, dmp, de)) { 450 vput(vp); 451 return (ENOENT); 452 } 453 else if ((vp->v_iflag & VI_DOOMED) != 0) { 454 mtx_lock(&devfs_de_interlock); 455 if (de->de_vnode == vp) { 456 de->de_vnode = NULL; 457 vp->v_data = NULL; 458 } 459 mtx_unlock(&devfs_de_interlock); 460 vput(vp); 461 goto loop; 462 } 463 sx_xunlock(&dmp->dm_lock); 464 *vpp = vp; 465 return (0); 466 } 467 mtx_unlock(&devfs_de_interlock); 468 if (de->de_dirent->d_type == DT_CHR) { 469 if (!(de->de_cdp->cdp_flags & CDP_ACTIVE)) { 470 devfs_allocv_drop_refs(1, dmp, de); 471 return (ENOENT); 472 } 473 dev = &de->de_cdp->cdp_c; 474 } else { 475 dev = NULL; 476 } 477 error = getnewvnode("devfs", mp, &devfs_vnodeops, &vp); 478 if (error != 0) { 479 devfs_allocv_drop_refs(1, dmp, de); 480 printf("devfs_allocv: failed to allocate new vnode\n"); 481 return (error); 482 } 483 484 if (de->de_dirent->d_type == DT_CHR) { 485 vp->v_type = VCHR; 486 VI_LOCK(vp); 487 dev_lock(); 488 dev_refl(dev); 489 /* XXX: v_rdev should be protect by vnode lock */ 490 vp->v_rdev = dev; 491 KASSERT(vp->v_usecount == 1, 492 ("%s %d (%d)\n", __func__, __LINE__, vp->v_usecount)); 493 dev->si_usecount += vp->v_usecount; 494 /* Special casing of ttys for deadfs. Probably redundant. */ 495 dsw = dev->si_devsw; 496 if (dsw != NULL && (dsw->d_flags & D_TTY) != 0) 497 vp->v_vflag |= VV_ISTTY; 498 dev_unlock(); 499 VI_UNLOCK(vp); 500 if ((dev->si_flags & SI_ETERNAL) != 0) 501 vp->v_vflag |= VV_ETERNALDEV; 502 vp->v_op = &devfs_specops; 503 } else if (de->de_dirent->d_type == DT_DIR) { 504 vp->v_type = VDIR; 505 } else if (de->de_dirent->d_type == DT_LNK) { 506 vp->v_type = VLNK; 507 } else { 508 vp->v_type = VBAD; 509 } 510 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY | LK_NOWITNESS); 511 VN_LOCK_ASHARE(vp); 512 mtx_lock(&devfs_de_interlock); 513 vp->v_data = de; 514 de->de_vnode = vp; 515 mtx_unlock(&devfs_de_interlock); 516 error = insmntque1(vp, mp, devfs_insmntque_dtr, de); 517 if (error != 0) { 518 (void) devfs_allocv_drop_refs(1, dmp, de); 519 return (error); 520 } 521 if (devfs_allocv_drop_refs(0, dmp, de)) { 522 vput(vp); 523 return (ENOENT); 524 } 525 #ifdef MAC 526 mac_devfs_vnode_associate(mp, de, vp); 527 #endif 528 sx_xunlock(&dmp->dm_lock); 529 *vpp = vp; 530 return (0); 531 } 532 533 static int 534 devfs_access(struct vop_access_args *ap) 535 { 536 struct vnode *vp = ap->a_vp; 537 struct devfs_dirent *de; 538 struct proc *p; 539 int error; 540 541 de = vp->v_data; 542 if (vp->v_type == VDIR) 543 de = de->de_dir; 544 545 error = vaccess(vp->v_type, de->de_mode, de->de_uid, de->de_gid, 546 ap->a_accmode, ap->a_cred, NULL); 547 if (error == 0) 548 return (0); 549 if (error != EACCES) 550 return (error); 551 p = ap->a_td->td_proc; 552 /* We do, however, allow access to the controlling terminal */ 553 PROC_LOCK(p); 554 if (!(p->p_flag & P_CONTROLT)) { 555 PROC_UNLOCK(p); 556 return (error); 557 } 558 if (p->p_session->s_ttydp == de->de_cdp) 559 error = 0; 560 PROC_UNLOCK(p); 561 return (error); 562 } 563 564 _Static_assert(((FMASK | FCNTLFLAGS) & (FLASTCLOSE | FREVOKE)) == 0, 565 "devfs-only flag reuse failed"); 566 567 static int 568 devfs_close(struct vop_close_args *ap) 569 { 570 struct vnode *vp = ap->a_vp, *oldvp; 571 struct thread *td = ap->a_td; 572 struct proc *p; 573 struct cdev *dev = vp->v_rdev; 574 struct cdevsw *dsw; 575 int dflags, error, ref, vp_locked; 576 577 /* 578 * XXX: Don't call d_close() if we were called because of 579 * XXX: insmntque1() failure. 580 */ 581 if (vp->v_data == NULL) 582 return (0); 583 584 /* 585 * Hack: a tty device that is a controlling terminal 586 * has a reference from the session structure. 587 * We cannot easily tell that a character device is 588 * a controlling terminal, unless it is the closing 589 * process' controlling terminal. In that case, 590 * if the reference count is 2 (this last descriptor 591 * plus the session), release the reference from the session. 592 */ 593 if (td != NULL) { 594 p = td->td_proc; 595 PROC_LOCK(p); 596 if (vp == p->p_session->s_ttyvp) { 597 PROC_UNLOCK(p); 598 oldvp = NULL; 599 sx_xlock(&proctree_lock); 600 if (vp == p->p_session->s_ttyvp) { 601 SESS_LOCK(p->p_session); 602 VI_LOCK(vp); 603 if (count_dev(dev) == 2 && 604 (vp->v_iflag & VI_DOOMED) == 0) { 605 p->p_session->s_ttyvp = NULL; 606 p->p_session->s_ttydp = NULL; 607 oldvp = vp; 608 } 609 VI_UNLOCK(vp); 610 SESS_UNLOCK(p->p_session); 611 } 612 sx_xunlock(&proctree_lock); 613 if (oldvp != NULL) 614 vrele(oldvp); 615 } else 616 PROC_UNLOCK(p); 617 } 618 /* 619 * We do not want to really close the device if it 620 * is still in use unless we are trying to close it 621 * forcibly. Since every use (buffer, vnode, swap, cmap) 622 * holds a reference to the vnode, and because we mark 623 * any other vnodes that alias this device, when the 624 * sum of the reference counts on all the aliased 625 * vnodes descends to one, we are on last close. 626 */ 627 dsw = dev_refthread(dev, &ref); 628 if (dsw == NULL) 629 return (ENXIO); 630 dflags = 0; 631 VI_LOCK(vp); 632 if (vp->v_iflag & VI_DOOMED) { 633 /* Forced close. */ 634 dflags |= FREVOKE | FNONBLOCK; 635 } else if (dsw->d_flags & D_TRACKCLOSE) { 636 /* Keep device updated on status. */ 637 } else if (count_dev(dev) > 1) { 638 VI_UNLOCK(vp); 639 dev_relthread(dev, ref); 640 return (0); 641 } 642 if (count_dev(dev) == 1) 643 dflags |= FLASTCLOSE; 644 vholdl(vp); 645 VI_UNLOCK(vp); 646 vp_locked = VOP_ISLOCKED(vp); 647 VOP_UNLOCK(vp, 0); 648 KASSERT(dev->si_refcount > 0, 649 ("devfs_close() on un-referenced struct cdev *(%s)", devtoname(dev))); 650 error = dsw->d_close(dev, ap->a_fflag | dflags, S_IFCHR, td); 651 dev_relthread(dev, ref); 652 vn_lock(vp, vp_locked | LK_RETRY); 653 vdrop(vp); 654 return (error); 655 } 656 657 static int 658 devfs_close_f(struct file *fp, struct thread *td) 659 { 660 int error; 661 struct file *fpop; 662 663 /* 664 * NB: td may be NULL if this descriptor is closed due to 665 * garbage collection from a closed UNIX domain socket. 666 */ 667 fpop = curthread->td_fpop; 668 curthread->td_fpop = fp; 669 error = vnops.fo_close(fp, td); 670 curthread->td_fpop = fpop; 671 672 /* 673 * The f_cdevpriv cannot be assigned non-NULL value while we 674 * are destroying the file. 675 */ 676 if (fp->f_cdevpriv != NULL) 677 devfs_fpdrop(fp); 678 return (error); 679 } 680 681 static int 682 devfs_getattr(struct vop_getattr_args *ap) 683 { 684 struct vnode *vp = ap->a_vp; 685 struct vattr *vap = ap->a_vap; 686 struct devfs_dirent *de; 687 struct devfs_mount *dmp; 688 struct cdev *dev; 689 struct timeval boottime; 690 int error; 691 692 error = devfs_populate_vp(vp); 693 if (error != 0) 694 return (error); 695 696 dmp = VFSTODEVFS(vp->v_mount); 697 sx_xunlock(&dmp->dm_lock); 698 699 de = vp->v_data; 700 KASSERT(de != NULL, ("Null dirent in devfs_getattr vp=%p", vp)); 701 if (vp->v_type == VDIR) { 702 de = de->de_dir; 703 KASSERT(de != NULL, 704 ("Null dir dirent in devfs_getattr vp=%p", vp)); 705 } 706 vap->va_uid = de->de_uid; 707 vap->va_gid = de->de_gid; 708 vap->va_mode = de->de_mode; 709 if (vp->v_type == VLNK) 710 vap->va_size = strlen(de->de_symlink); 711 else if (vp->v_type == VDIR) 712 vap->va_size = vap->va_bytes = DEV_BSIZE; 713 else 714 vap->va_size = 0; 715 if (vp->v_type != VDIR) 716 vap->va_bytes = 0; 717 vap->va_blocksize = DEV_BSIZE; 718 vap->va_type = vp->v_type; 719 720 getboottime(&boottime); 721 #define fix(aa) \ 722 do { \ 723 if ((aa).tv_sec <= 3600) { \ 724 (aa).tv_sec = boottime.tv_sec; \ 725 (aa).tv_nsec = boottime.tv_usec * 1000; \ 726 } \ 727 } while (0) 728 729 if (vp->v_type != VCHR) { 730 fix(de->de_atime); 731 vap->va_atime = de->de_atime; 732 fix(de->de_mtime); 733 vap->va_mtime = de->de_mtime; 734 fix(de->de_ctime); 735 vap->va_ctime = de->de_ctime; 736 } else { 737 dev = vp->v_rdev; 738 fix(dev->si_atime); 739 vap->va_atime = dev->si_atime; 740 fix(dev->si_mtime); 741 vap->va_mtime = dev->si_mtime; 742 fix(dev->si_ctime); 743 vap->va_ctime = dev->si_ctime; 744 745 vap->va_rdev = cdev2priv(dev)->cdp_inode; 746 } 747 vap->va_gen = 0; 748 vap->va_flags = 0; 749 vap->va_filerev = 0; 750 vap->va_nlink = de->de_links; 751 vap->va_fileid = de->de_inode; 752 753 return (error); 754 } 755 756 /* ARGSUSED */ 757 static int 758 devfs_ioctl_f(struct file *fp, u_long com, void *data, struct ucred *cred, struct thread *td) 759 { 760 struct file *fpop; 761 int error; 762 763 fpop = td->td_fpop; 764 td->td_fpop = fp; 765 error = vnops.fo_ioctl(fp, com, data, cred, td); 766 td->td_fpop = fpop; 767 return (error); 768 } 769 770 static int 771 devfs_ioctl(struct vop_ioctl_args *ap) 772 { 773 struct fiodgname_arg *fgn; 774 struct vnode *vpold, *vp; 775 struct cdevsw *dsw; 776 struct thread *td; 777 struct cdev *dev; 778 int error, ref, i; 779 const char *p; 780 u_long com; 781 782 vp = ap->a_vp; 783 com = ap->a_command; 784 td = ap->a_td; 785 786 dsw = devvn_refthread(vp, &dev, &ref); 787 if (dsw == NULL) 788 return (ENXIO); 789 KASSERT(dev->si_refcount > 0, 790 ("devfs: un-referenced struct cdev *(%s)", devtoname(dev))); 791 792 if (com == FIODTYPE) { 793 *(int *)ap->a_data = dsw->d_flags & D_TYPEMASK; 794 error = 0; 795 goto out; 796 } else if (com == FIODGNAME) { 797 fgn = ap->a_data; 798 p = devtoname(dev); 799 i = strlen(p) + 1; 800 if (i > fgn->len) 801 error = EINVAL; 802 else 803 error = copyout(p, fgn->buf, i); 804 goto out; 805 } 806 807 error = dsw->d_ioctl(dev, com, ap->a_data, ap->a_fflag, td); 808 809 out: 810 dev_relthread(dev, ref); 811 if (error == ENOIOCTL) 812 error = ENOTTY; 813 814 if (error == 0 && com == TIOCSCTTY) { 815 /* Do nothing if reassigning same control tty */ 816 sx_slock(&proctree_lock); 817 if (td->td_proc->p_session->s_ttyvp == vp) { 818 sx_sunlock(&proctree_lock); 819 return (0); 820 } 821 822 vpold = td->td_proc->p_session->s_ttyvp; 823 VREF(vp); 824 SESS_LOCK(td->td_proc->p_session); 825 td->td_proc->p_session->s_ttyvp = vp; 826 td->td_proc->p_session->s_ttydp = cdev2priv(dev); 827 SESS_UNLOCK(td->td_proc->p_session); 828 829 sx_sunlock(&proctree_lock); 830 831 /* Get rid of reference to old control tty */ 832 if (vpold) 833 vrele(vpold); 834 } 835 return (error); 836 } 837 838 /* ARGSUSED */ 839 static int 840 devfs_kqfilter_f(struct file *fp, struct knote *kn) 841 { 842 struct cdev *dev; 843 struct cdevsw *dsw; 844 int error, ref; 845 struct file *fpop; 846 struct thread *td; 847 848 td = curthread; 849 fpop = td->td_fpop; 850 error = devfs_fp_check(fp, &dev, &dsw, &ref); 851 if (error) 852 return (error); 853 error = dsw->d_kqfilter(dev, kn); 854 td->td_fpop = fpop; 855 dev_relthread(dev, ref); 856 return (error); 857 } 858 859 static inline int 860 devfs_prison_check(struct devfs_dirent *de, struct thread *td) 861 { 862 struct cdev_priv *cdp; 863 struct ucred *dcr; 864 struct proc *p; 865 int error; 866 867 cdp = de->de_cdp; 868 if (cdp == NULL) 869 return (0); 870 dcr = cdp->cdp_c.si_cred; 871 if (dcr == NULL) 872 return (0); 873 874 error = prison_check(td->td_ucred, dcr); 875 if (error == 0) 876 return (0); 877 /* We do, however, allow access to the controlling terminal */ 878 p = td->td_proc; 879 PROC_LOCK(p); 880 if (!(p->p_flag & P_CONTROLT)) { 881 PROC_UNLOCK(p); 882 return (error); 883 } 884 if (p->p_session->s_ttydp == cdp) 885 error = 0; 886 PROC_UNLOCK(p); 887 return (error); 888 } 889 890 static int 891 devfs_lookupx(struct vop_lookup_args *ap, int *dm_unlock) 892 { 893 struct componentname *cnp; 894 struct vnode *dvp, **vpp; 895 struct thread *td; 896 struct devfs_dirent *de, *dd; 897 struct devfs_dirent **dde; 898 struct devfs_mount *dmp; 899 struct mount *mp; 900 struct cdev *cdev; 901 int error, flags, nameiop, dvplocked; 902 char specname[SPECNAMELEN + 1], *pname; 903 904 cnp = ap->a_cnp; 905 vpp = ap->a_vpp; 906 dvp = ap->a_dvp; 907 pname = cnp->cn_nameptr; 908 td = cnp->cn_thread; 909 flags = cnp->cn_flags; 910 nameiop = cnp->cn_nameiop; 911 mp = dvp->v_mount; 912 dmp = VFSTODEVFS(mp); 913 dd = dvp->v_data; 914 *vpp = NULLVP; 915 916 if ((flags & ISLASTCN) && nameiop == RENAME) 917 return (EOPNOTSUPP); 918 919 if (dvp->v_type != VDIR) 920 return (ENOTDIR); 921 922 if ((flags & ISDOTDOT) && (dvp->v_vflag & VV_ROOT)) 923 return (EIO); 924 925 error = VOP_ACCESS(dvp, VEXEC, cnp->cn_cred, td); 926 if (error) 927 return (error); 928 929 if (cnp->cn_namelen == 1 && *pname == '.') { 930 if ((flags & ISLASTCN) && nameiop != LOOKUP) 931 return (EINVAL); 932 *vpp = dvp; 933 VREF(dvp); 934 return (0); 935 } 936 937 if (flags & ISDOTDOT) { 938 if ((flags & ISLASTCN) && nameiop != LOOKUP) 939 return (EINVAL); 940 de = devfs_parent_dirent(dd); 941 if (de == NULL) 942 return (ENOENT); 943 dvplocked = VOP_ISLOCKED(dvp); 944 VOP_UNLOCK(dvp, 0); 945 error = devfs_allocv(de, mp, cnp->cn_lkflags & LK_TYPE_MASK, 946 vpp); 947 *dm_unlock = 0; 948 vn_lock(dvp, dvplocked | LK_RETRY); 949 return (error); 950 } 951 952 dd = dvp->v_data; 953 de = devfs_find(dd, cnp->cn_nameptr, cnp->cn_namelen, 0); 954 while (de == NULL) { /* While(...) so we can use break */ 955 956 if (nameiop == DELETE) 957 return (ENOENT); 958 959 /* 960 * OK, we didn't have an entry for the name we were asked for 961 * so we try to see if anybody can create it on demand. 962 */ 963 pname = devfs_fqpn(specname, dmp, dd, cnp); 964 if (pname == NULL) 965 break; 966 967 cdev = NULL; 968 DEVFS_DMP_HOLD(dmp); 969 sx_xunlock(&dmp->dm_lock); 970 sx_slock(&clone_drain_lock); 971 EVENTHANDLER_INVOKE(dev_clone, 972 td->td_ucred, pname, strlen(pname), &cdev); 973 sx_sunlock(&clone_drain_lock); 974 975 if (cdev == NULL) 976 sx_xlock(&dmp->dm_lock); 977 else if (devfs_populate_vp(dvp) != 0) { 978 *dm_unlock = 0; 979 sx_xlock(&dmp->dm_lock); 980 if (DEVFS_DMP_DROP(dmp)) { 981 sx_xunlock(&dmp->dm_lock); 982 devfs_unmount_final(dmp); 983 } else 984 sx_xunlock(&dmp->dm_lock); 985 dev_rel(cdev); 986 return (ENOENT); 987 } 988 if (DEVFS_DMP_DROP(dmp)) { 989 *dm_unlock = 0; 990 sx_xunlock(&dmp->dm_lock); 991 devfs_unmount_final(dmp); 992 if (cdev != NULL) 993 dev_rel(cdev); 994 return (ENOENT); 995 } 996 997 if (cdev == NULL) 998 break; 999 1000 dev_lock(); 1001 dde = &cdev2priv(cdev)->cdp_dirents[dmp->dm_idx]; 1002 if (dde != NULL && *dde != NULL) 1003 de = *dde; 1004 dev_unlock(); 1005 dev_rel(cdev); 1006 break; 1007 } 1008 1009 if (de == NULL || de->de_flags & DE_WHITEOUT) { 1010 if ((nameiop == CREATE || nameiop == RENAME) && 1011 (flags & (LOCKPARENT | WANTPARENT)) && (flags & ISLASTCN)) { 1012 cnp->cn_flags |= SAVENAME; 1013 return (EJUSTRETURN); 1014 } 1015 return (ENOENT); 1016 } 1017 1018 if (devfs_prison_check(de, td)) 1019 return (ENOENT); 1020 1021 if ((cnp->cn_nameiop == DELETE) && (flags & ISLASTCN)) { 1022 error = VOP_ACCESS(dvp, VWRITE, cnp->cn_cred, td); 1023 if (error) 1024 return (error); 1025 if (*vpp == dvp) { 1026 VREF(dvp); 1027 *vpp = dvp; 1028 return (0); 1029 } 1030 } 1031 error = devfs_allocv(de, mp, cnp->cn_lkflags & LK_TYPE_MASK, vpp); 1032 *dm_unlock = 0; 1033 return (error); 1034 } 1035 1036 static int 1037 devfs_lookup(struct vop_lookup_args *ap) 1038 { 1039 int j; 1040 struct devfs_mount *dmp; 1041 int dm_unlock; 1042 1043 if (devfs_populate_vp(ap->a_dvp) != 0) 1044 return (ENOTDIR); 1045 1046 dmp = VFSTODEVFS(ap->a_dvp->v_mount); 1047 dm_unlock = 1; 1048 j = devfs_lookupx(ap, &dm_unlock); 1049 if (dm_unlock == 1) 1050 sx_xunlock(&dmp->dm_lock); 1051 return (j); 1052 } 1053 1054 static int 1055 devfs_mknod(struct vop_mknod_args *ap) 1056 { 1057 struct componentname *cnp; 1058 struct vnode *dvp, **vpp; 1059 struct devfs_dirent *dd, *de; 1060 struct devfs_mount *dmp; 1061 int error; 1062 1063 /* 1064 * The only type of node we should be creating here is a 1065 * character device, for anything else return EOPNOTSUPP. 1066 */ 1067 if (ap->a_vap->va_type != VCHR) 1068 return (EOPNOTSUPP); 1069 dvp = ap->a_dvp; 1070 dmp = VFSTODEVFS(dvp->v_mount); 1071 1072 cnp = ap->a_cnp; 1073 vpp = ap->a_vpp; 1074 dd = dvp->v_data; 1075 1076 error = ENOENT; 1077 sx_xlock(&dmp->dm_lock); 1078 TAILQ_FOREACH(de, &dd->de_dlist, de_list) { 1079 if (cnp->cn_namelen != de->de_dirent->d_namlen) 1080 continue; 1081 if (de->de_dirent->d_type == DT_CHR && 1082 (de->de_cdp->cdp_flags & CDP_ACTIVE) == 0) 1083 continue; 1084 if (bcmp(cnp->cn_nameptr, de->de_dirent->d_name, 1085 de->de_dirent->d_namlen) != 0) 1086 continue; 1087 if (de->de_flags & DE_WHITEOUT) 1088 break; 1089 goto notfound; 1090 } 1091 if (de == NULL) 1092 goto notfound; 1093 de->de_flags &= ~DE_WHITEOUT; 1094 error = devfs_allocv(de, dvp->v_mount, LK_EXCLUSIVE, vpp); 1095 return (error); 1096 notfound: 1097 sx_xunlock(&dmp->dm_lock); 1098 return (error); 1099 } 1100 1101 /* ARGSUSED */ 1102 static int 1103 devfs_open(struct vop_open_args *ap) 1104 { 1105 struct thread *td = ap->a_td; 1106 struct vnode *vp = ap->a_vp; 1107 struct cdev *dev = vp->v_rdev; 1108 struct file *fp = ap->a_fp; 1109 int error, ref, vlocked; 1110 struct cdevsw *dsw; 1111 struct file *fpop; 1112 struct mtx *mtxp; 1113 1114 if (vp->v_type == VBLK) 1115 return (ENXIO); 1116 1117 if (dev == NULL) 1118 return (ENXIO); 1119 1120 /* Make this field valid before any I/O in d_open. */ 1121 if (dev->si_iosize_max == 0) 1122 dev->si_iosize_max = DFLTPHYS; 1123 1124 dsw = dev_refthread(dev, &ref); 1125 if (dsw == NULL) 1126 return (ENXIO); 1127 if (fp == NULL && dsw->d_fdopen != NULL) { 1128 dev_relthread(dev, ref); 1129 return (ENXIO); 1130 } 1131 1132 vlocked = VOP_ISLOCKED(vp); 1133 VOP_UNLOCK(vp, 0); 1134 1135 fpop = td->td_fpop; 1136 td->td_fpop = fp; 1137 if (fp != NULL) { 1138 fp->f_data = dev; 1139 fp->f_vnode = vp; 1140 } 1141 if (dsw->d_fdopen != NULL) 1142 error = dsw->d_fdopen(dev, ap->a_mode, td, fp); 1143 else 1144 error = dsw->d_open(dev, ap->a_mode, S_IFCHR, td); 1145 /* Clean up any cdevpriv upon error. */ 1146 if (error != 0) 1147 devfs_clear_cdevpriv(); 1148 td->td_fpop = fpop; 1149 1150 vn_lock(vp, vlocked | LK_RETRY); 1151 dev_relthread(dev, ref); 1152 if (error != 0) { 1153 if (error == ERESTART) 1154 error = EINTR; 1155 return (error); 1156 } 1157 1158 #if 0 /* /dev/console */ 1159 KASSERT(fp != NULL, ("Could not vnode bypass device on NULL fp")); 1160 #else 1161 if (fp == NULL) 1162 return (error); 1163 #endif 1164 if (fp->f_ops == &badfileops) 1165 finit(fp, fp->f_flag, DTYPE_VNODE, dev, &devfs_ops_f); 1166 mtxp = mtx_pool_find(mtxpool_sleep, fp); 1167 1168 /* 1169 * Hint to the dofilewrite() to not force the buffer draining 1170 * on the writer to the file. Most likely, the write would 1171 * not need normal buffers. 1172 */ 1173 mtx_lock(mtxp); 1174 fp->f_vnread_flags |= FDEVFS_VNODE; 1175 mtx_unlock(mtxp); 1176 return (error); 1177 } 1178 1179 static int 1180 devfs_pathconf(struct vop_pathconf_args *ap) 1181 { 1182 1183 switch (ap->a_name) { 1184 case _PC_FILESIZEBITS: 1185 *ap->a_retval = 64; 1186 return (0); 1187 case _PC_NAME_MAX: 1188 *ap->a_retval = NAME_MAX; 1189 return (0); 1190 case _PC_LINK_MAX: 1191 *ap->a_retval = INT_MAX; 1192 return (0); 1193 case _PC_SYMLINK_MAX: 1194 *ap->a_retval = MAXPATHLEN; 1195 return (0); 1196 case _PC_MAX_CANON: 1197 if (ap->a_vp->v_vflag & VV_ISTTY) { 1198 *ap->a_retval = MAX_CANON; 1199 return (0); 1200 } 1201 return (EINVAL); 1202 case _PC_MAX_INPUT: 1203 if (ap->a_vp->v_vflag & VV_ISTTY) { 1204 *ap->a_retval = MAX_INPUT; 1205 return (0); 1206 } 1207 return (EINVAL); 1208 case _PC_VDISABLE: 1209 if (ap->a_vp->v_vflag & VV_ISTTY) { 1210 *ap->a_retval = _POSIX_VDISABLE; 1211 return (0); 1212 } 1213 return (EINVAL); 1214 case _PC_MAC_PRESENT: 1215 #ifdef MAC 1216 /* 1217 * If MAC is enabled, devfs automatically supports 1218 * trivial non-persistant label storage. 1219 */ 1220 *ap->a_retval = 1; 1221 #else 1222 *ap->a_retval = 0; 1223 #endif 1224 return (0); 1225 case _PC_CHOWN_RESTRICTED: 1226 *ap->a_retval = 1; 1227 return (0); 1228 default: 1229 return (vop_stdpathconf(ap)); 1230 } 1231 /* NOTREACHED */ 1232 } 1233 1234 /* ARGSUSED */ 1235 static int 1236 devfs_poll_f(struct file *fp, int events, struct ucred *cred, struct thread *td) 1237 { 1238 struct cdev *dev; 1239 struct cdevsw *dsw; 1240 int error, ref; 1241 struct file *fpop; 1242 1243 fpop = td->td_fpop; 1244 error = devfs_fp_check(fp, &dev, &dsw, &ref); 1245 if (error != 0) { 1246 error = vnops.fo_poll(fp, events, cred, td); 1247 return (error); 1248 } 1249 error = dsw->d_poll(dev, events, td); 1250 td->td_fpop = fpop; 1251 dev_relthread(dev, ref); 1252 return(error); 1253 } 1254 1255 /* 1256 * Print out the contents of a special device vnode. 1257 */ 1258 static int 1259 devfs_print(struct vop_print_args *ap) 1260 { 1261 1262 printf("\tdev %s\n", devtoname(ap->a_vp->v_rdev)); 1263 return (0); 1264 } 1265 1266 static int 1267 devfs_read_f(struct file *fp, struct uio *uio, struct ucred *cred, 1268 int flags, struct thread *td) 1269 { 1270 struct cdev *dev; 1271 int ioflag, error, ref; 1272 ssize_t resid; 1273 struct cdevsw *dsw; 1274 struct file *fpop; 1275 1276 if (uio->uio_resid > DEVFS_IOSIZE_MAX) 1277 return (EINVAL); 1278 fpop = td->td_fpop; 1279 error = devfs_fp_check(fp, &dev, &dsw, &ref); 1280 if (error != 0) { 1281 error = vnops.fo_read(fp, uio, cred, flags, td); 1282 return (error); 1283 } 1284 resid = uio->uio_resid; 1285 ioflag = fp->f_flag & (O_NONBLOCK | O_DIRECT); 1286 if (ioflag & O_DIRECT) 1287 ioflag |= IO_DIRECT; 1288 1289 foffset_lock_uio(fp, uio, flags | FOF_NOLOCK); 1290 error = dsw->d_read(dev, uio, ioflag); 1291 if (uio->uio_resid != resid || (error == 0 && resid != 0)) 1292 devfs_timestamp(&dev->si_atime); 1293 td->td_fpop = fpop; 1294 dev_relthread(dev, ref); 1295 1296 foffset_unlock_uio(fp, uio, flags | FOF_NOLOCK | FOF_NEXTOFF); 1297 return (error); 1298 } 1299 1300 static int 1301 devfs_readdir(struct vop_readdir_args *ap) 1302 { 1303 int error; 1304 struct uio *uio; 1305 struct dirent *dp; 1306 struct devfs_dirent *dd; 1307 struct devfs_dirent *de; 1308 struct devfs_mount *dmp; 1309 off_t off; 1310 int *tmp_ncookies = NULL; 1311 1312 if (ap->a_vp->v_type != VDIR) 1313 return (ENOTDIR); 1314 1315 uio = ap->a_uio; 1316 if (uio->uio_offset < 0) 1317 return (EINVAL); 1318 1319 /* 1320 * XXX: This is a temporary hack to get around this filesystem not 1321 * supporting cookies. We store the location of the ncookies pointer 1322 * in a temporary variable before calling vfs_subr.c:vfs_read_dirent() 1323 * and set the number of cookies to 0. We then set the pointer to 1324 * NULL so that vfs_read_dirent doesn't try to call realloc() on 1325 * ap->a_cookies. Later in this function, we restore the ap->a_ncookies 1326 * pointer to its original location before returning to the caller. 1327 */ 1328 if (ap->a_ncookies != NULL) { 1329 tmp_ncookies = ap->a_ncookies; 1330 *ap->a_ncookies = 0; 1331 ap->a_ncookies = NULL; 1332 } 1333 1334 dmp = VFSTODEVFS(ap->a_vp->v_mount); 1335 if (devfs_populate_vp(ap->a_vp) != 0) { 1336 if (tmp_ncookies != NULL) 1337 ap->a_ncookies = tmp_ncookies; 1338 return (EIO); 1339 } 1340 error = 0; 1341 de = ap->a_vp->v_data; 1342 off = 0; 1343 TAILQ_FOREACH(dd, &de->de_dlist, de_list) { 1344 KASSERT(dd->de_cdp != (void *)0xdeadc0de, ("%s %d\n", __func__, __LINE__)); 1345 if (dd->de_flags & (DE_COVERED | DE_WHITEOUT)) 1346 continue; 1347 if (devfs_prison_check(dd, uio->uio_td)) 1348 continue; 1349 if (dd->de_dirent->d_type == DT_DIR) 1350 de = dd->de_dir; 1351 else 1352 de = dd; 1353 dp = dd->de_dirent; 1354 MPASS(dp->d_reclen == GENERIC_DIRSIZ(dp)); 1355 if (dp->d_reclen > uio->uio_resid) 1356 break; 1357 dp->d_fileno = de->de_inode; 1358 if (off >= uio->uio_offset) { 1359 error = vfs_read_dirent(ap, dp, off); 1360 if (error) 1361 break; 1362 } 1363 off += dp->d_reclen; 1364 } 1365 sx_xunlock(&dmp->dm_lock); 1366 uio->uio_offset = off; 1367 1368 /* 1369 * Restore ap->a_ncookies if it wasn't originally NULL in the first 1370 * place. 1371 */ 1372 if (tmp_ncookies != NULL) 1373 ap->a_ncookies = tmp_ncookies; 1374 1375 return (error); 1376 } 1377 1378 static int 1379 devfs_readlink(struct vop_readlink_args *ap) 1380 { 1381 struct devfs_dirent *de; 1382 1383 de = ap->a_vp->v_data; 1384 return (uiomove(de->de_symlink, strlen(de->de_symlink), ap->a_uio)); 1385 } 1386 1387 static int 1388 devfs_reclaim(struct vop_reclaim_args *ap) 1389 { 1390 struct vnode *vp; 1391 struct devfs_dirent *de; 1392 1393 vp = ap->a_vp; 1394 mtx_lock(&devfs_de_interlock); 1395 de = vp->v_data; 1396 if (de != NULL) { 1397 de->de_vnode = NULL; 1398 vp->v_data = NULL; 1399 } 1400 mtx_unlock(&devfs_de_interlock); 1401 vnode_destroy_vobject(vp); 1402 return (0); 1403 } 1404 1405 static int 1406 devfs_reclaim_vchr(struct vop_reclaim_args *ap) 1407 { 1408 struct vnode *vp; 1409 struct cdev *dev; 1410 1411 vp = ap->a_vp; 1412 MPASS(vp->v_type == VCHR); 1413 1414 devfs_reclaim(ap); 1415 1416 VI_LOCK(vp); 1417 dev_lock(); 1418 dev = vp->v_rdev; 1419 vp->v_rdev = NULL; 1420 if (dev != NULL) 1421 dev->si_usecount -= vp->v_usecount; 1422 dev_unlock(); 1423 VI_UNLOCK(vp); 1424 if (dev != NULL) 1425 dev_rel(dev); 1426 return (0); 1427 } 1428 1429 static int 1430 devfs_remove(struct vop_remove_args *ap) 1431 { 1432 struct vnode *dvp = ap->a_dvp; 1433 struct vnode *vp = ap->a_vp; 1434 struct devfs_dirent *dd; 1435 struct devfs_dirent *de, *de_covered; 1436 struct devfs_mount *dmp = VFSTODEVFS(vp->v_mount); 1437 1438 ASSERT_VOP_ELOCKED(dvp, "devfs_remove"); 1439 ASSERT_VOP_ELOCKED(vp, "devfs_remove"); 1440 1441 sx_xlock(&dmp->dm_lock); 1442 dd = ap->a_dvp->v_data; 1443 de = vp->v_data; 1444 if (de->de_cdp == NULL) { 1445 TAILQ_REMOVE(&dd->de_dlist, de, de_list); 1446 if (de->de_dirent->d_type == DT_LNK) { 1447 de_covered = devfs_find(dd, de->de_dirent->d_name, 1448 de->de_dirent->d_namlen, 0); 1449 if (de_covered != NULL) 1450 de_covered->de_flags &= ~DE_COVERED; 1451 } 1452 /* We need to unlock dvp because devfs_delete() may lock it. */ 1453 VOP_UNLOCK(vp, 0); 1454 if (dvp != vp) 1455 VOP_UNLOCK(dvp, 0); 1456 devfs_delete(dmp, de, 0); 1457 sx_xunlock(&dmp->dm_lock); 1458 if (dvp != vp) 1459 vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY); 1460 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1461 } else { 1462 de->de_flags |= DE_WHITEOUT; 1463 sx_xunlock(&dmp->dm_lock); 1464 } 1465 return (0); 1466 } 1467 1468 /* 1469 * Revoke is called on a tty when a terminal session ends. The vnode 1470 * is orphaned by setting v_op to deadfs so we need to let go of it 1471 * as well so that we create a new one next time around. 1472 * 1473 */ 1474 static int 1475 devfs_revoke(struct vop_revoke_args *ap) 1476 { 1477 struct vnode *vp = ap->a_vp, *vp2; 1478 struct cdev *dev; 1479 struct cdev_priv *cdp; 1480 struct devfs_dirent *de; 1481 u_int i; 1482 1483 KASSERT((ap->a_flags & REVOKEALL) != 0, ("devfs_revoke !REVOKEALL")); 1484 1485 dev = vp->v_rdev; 1486 cdp = cdev2priv(dev); 1487 1488 dev_lock(); 1489 cdp->cdp_inuse++; 1490 dev_unlock(); 1491 1492 vhold(vp); 1493 vgone(vp); 1494 vdrop(vp); 1495 1496 VOP_UNLOCK(vp,0); 1497 loop: 1498 for (;;) { 1499 mtx_lock(&devfs_de_interlock); 1500 dev_lock(); 1501 vp2 = NULL; 1502 for (i = 0; i <= cdp->cdp_maxdirent; i++) { 1503 de = cdp->cdp_dirents[i]; 1504 if (de == NULL) 1505 continue; 1506 1507 vp2 = de->de_vnode; 1508 if (vp2 != NULL) { 1509 dev_unlock(); 1510 VI_LOCK(vp2); 1511 mtx_unlock(&devfs_de_interlock); 1512 if (vget(vp2, LK_EXCLUSIVE | LK_INTERLOCK, 1513 curthread)) 1514 goto loop; 1515 vhold(vp2); 1516 vgone(vp2); 1517 vdrop(vp2); 1518 vput(vp2); 1519 break; 1520 } 1521 } 1522 if (vp2 != NULL) { 1523 continue; 1524 } 1525 dev_unlock(); 1526 mtx_unlock(&devfs_de_interlock); 1527 break; 1528 } 1529 dev_lock(); 1530 cdp->cdp_inuse--; 1531 if (!(cdp->cdp_flags & CDP_ACTIVE) && cdp->cdp_inuse == 0) { 1532 TAILQ_REMOVE(&cdevp_list, cdp, cdp_list); 1533 dev_unlock(); 1534 dev_rel(&cdp->cdp_c); 1535 } else 1536 dev_unlock(); 1537 1538 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1539 return (0); 1540 } 1541 1542 static int 1543 devfs_rioctl(struct vop_ioctl_args *ap) 1544 { 1545 struct vnode *vp; 1546 struct devfs_mount *dmp; 1547 int error; 1548 1549 vp = ap->a_vp; 1550 vn_lock(vp, LK_SHARED | LK_RETRY); 1551 if (vp->v_iflag & VI_DOOMED) { 1552 VOP_UNLOCK(vp, 0); 1553 return (EBADF); 1554 } 1555 dmp = VFSTODEVFS(vp->v_mount); 1556 sx_xlock(&dmp->dm_lock); 1557 VOP_UNLOCK(vp, 0); 1558 DEVFS_DMP_HOLD(dmp); 1559 devfs_populate(dmp); 1560 if (DEVFS_DMP_DROP(dmp)) { 1561 sx_xunlock(&dmp->dm_lock); 1562 devfs_unmount_final(dmp); 1563 return (ENOENT); 1564 } 1565 error = devfs_rules_ioctl(dmp, ap->a_command, ap->a_data, ap->a_td); 1566 sx_xunlock(&dmp->dm_lock); 1567 return (error); 1568 } 1569 1570 static int 1571 devfs_rread(struct vop_read_args *ap) 1572 { 1573 1574 if (ap->a_vp->v_type != VDIR) 1575 return (EINVAL); 1576 return (VOP_READDIR(ap->a_vp, ap->a_uio, ap->a_cred, NULL, NULL, NULL)); 1577 } 1578 1579 static int 1580 devfs_setattr(struct vop_setattr_args *ap) 1581 { 1582 struct devfs_dirent *de; 1583 struct vattr *vap; 1584 struct vnode *vp; 1585 struct thread *td; 1586 int c, error; 1587 uid_t uid; 1588 gid_t gid; 1589 1590 vap = ap->a_vap; 1591 vp = ap->a_vp; 1592 td = curthread; 1593 if ((vap->va_type != VNON) || 1594 (vap->va_nlink != VNOVAL) || 1595 (vap->va_fsid != VNOVAL) || 1596 (vap->va_fileid != VNOVAL) || 1597 (vap->va_blocksize != VNOVAL) || 1598 (vap->va_flags != VNOVAL && vap->va_flags != 0) || 1599 (vap->va_rdev != VNOVAL) || 1600 ((int)vap->va_bytes != VNOVAL) || 1601 (vap->va_gen != VNOVAL)) { 1602 return (EINVAL); 1603 } 1604 1605 error = devfs_populate_vp(vp); 1606 if (error != 0) 1607 return (error); 1608 1609 de = vp->v_data; 1610 if (vp->v_type == VDIR) 1611 de = de->de_dir; 1612 1613 c = 0; 1614 if (vap->va_uid == (uid_t)VNOVAL) 1615 uid = de->de_uid; 1616 else 1617 uid = vap->va_uid; 1618 if (vap->va_gid == (gid_t)VNOVAL) 1619 gid = de->de_gid; 1620 else 1621 gid = vap->va_gid; 1622 if (uid != de->de_uid || gid != de->de_gid) { 1623 if ((ap->a_cred->cr_uid != de->de_uid) || uid != de->de_uid || 1624 (gid != de->de_gid && !groupmember(gid, ap->a_cred))) { 1625 error = priv_check(td, PRIV_VFS_CHOWN); 1626 if (error != 0) 1627 goto ret; 1628 } 1629 de->de_uid = uid; 1630 de->de_gid = gid; 1631 c = 1; 1632 } 1633 1634 if (vap->va_mode != (mode_t)VNOVAL) { 1635 if (ap->a_cred->cr_uid != de->de_uid) { 1636 error = priv_check(td, PRIV_VFS_ADMIN); 1637 if (error != 0) 1638 goto ret; 1639 } 1640 de->de_mode = vap->va_mode; 1641 c = 1; 1642 } 1643 1644 if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL) { 1645 error = vn_utimes_perm(vp, vap, ap->a_cred, td); 1646 if (error != 0) 1647 goto ret; 1648 if (vap->va_atime.tv_sec != VNOVAL) { 1649 if (vp->v_type == VCHR) 1650 vp->v_rdev->si_atime = vap->va_atime; 1651 else 1652 de->de_atime = vap->va_atime; 1653 } 1654 if (vap->va_mtime.tv_sec != VNOVAL) { 1655 if (vp->v_type == VCHR) 1656 vp->v_rdev->si_mtime = vap->va_mtime; 1657 else 1658 de->de_mtime = vap->va_mtime; 1659 } 1660 c = 1; 1661 } 1662 1663 if (c) { 1664 if (vp->v_type == VCHR) 1665 vfs_timestamp(&vp->v_rdev->si_ctime); 1666 else 1667 vfs_timestamp(&de->de_mtime); 1668 } 1669 1670 ret: 1671 sx_xunlock(&VFSTODEVFS(vp->v_mount)->dm_lock); 1672 return (error); 1673 } 1674 1675 #ifdef MAC 1676 static int 1677 devfs_setlabel(struct vop_setlabel_args *ap) 1678 { 1679 struct vnode *vp; 1680 struct devfs_dirent *de; 1681 1682 vp = ap->a_vp; 1683 de = vp->v_data; 1684 1685 mac_vnode_relabel(ap->a_cred, vp, ap->a_label); 1686 mac_devfs_update(vp->v_mount, de, vp); 1687 1688 return (0); 1689 } 1690 #endif 1691 1692 static int 1693 devfs_stat_f(struct file *fp, struct stat *sb, struct ucred *cred, struct thread *td) 1694 { 1695 1696 return (vnops.fo_stat(fp, sb, cred, td)); 1697 } 1698 1699 static int 1700 devfs_symlink(struct vop_symlink_args *ap) 1701 { 1702 int i, error; 1703 struct devfs_dirent *dd; 1704 struct devfs_dirent *de, *de_covered, *de_dotdot; 1705 struct devfs_mount *dmp; 1706 1707 error = priv_check(curthread, PRIV_DEVFS_SYMLINK); 1708 if (error) 1709 return(error); 1710 dmp = VFSTODEVFS(ap->a_dvp->v_mount); 1711 if (devfs_populate_vp(ap->a_dvp) != 0) 1712 return (ENOENT); 1713 1714 dd = ap->a_dvp->v_data; 1715 de = devfs_newdirent(ap->a_cnp->cn_nameptr, ap->a_cnp->cn_namelen); 1716 de->de_flags = DE_USER; 1717 de->de_uid = 0; 1718 de->de_gid = 0; 1719 de->de_mode = 0755; 1720 de->de_inode = alloc_unr(devfs_inos); 1721 de->de_dir = dd; 1722 de->de_dirent->d_type = DT_LNK; 1723 i = strlen(ap->a_target) + 1; 1724 de->de_symlink = malloc(i, M_DEVFS, M_WAITOK); 1725 bcopy(ap->a_target, de->de_symlink, i); 1726 #ifdef MAC 1727 mac_devfs_create_symlink(ap->a_cnp->cn_cred, dmp->dm_mount, dd, de); 1728 #endif 1729 de_covered = devfs_find(dd, de->de_dirent->d_name, 1730 de->de_dirent->d_namlen, 0); 1731 if (de_covered != NULL) { 1732 if ((de_covered->de_flags & DE_USER) != 0) { 1733 devfs_delete(dmp, de, DEVFS_DEL_NORECURSE); 1734 sx_xunlock(&dmp->dm_lock); 1735 return (EEXIST); 1736 } 1737 KASSERT((de_covered->de_flags & DE_COVERED) == 0, 1738 ("devfs_symlink: entry %p already covered", de_covered)); 1739 de_covered->de_flags |= DE_COVERED; 1740 } 1741 1742 de_dotdot = TAILQ_FIRST(&dd->de_dlist); /* "." */ 1743 de_dotdot = TAILQ_NEXT(de_dotdot, de_list); /* ".." */ 1744 TAILQ_INSERT_AFTER(&dd->de_dlist, de_dotdot, de, de_list); 1745 devfs_dir_ref_de(dmp, dd); 1746 devfs_rules_apply(dmp, de); 1747 1748 return (devfs_allocv(de, ap->a_dvp->v_mount, LK_EXCLUSIVE, ap->a_vpp)); 1749 } 1750 1751 static int 1752 devfs_truncate_f(struct file *fp, off_t length, struct ucred *cred, struct thread *td) 1753 { 1754 1755 return (vnops.fo_truncate(fp, length, cred, td)); 1756 } 1757 1758 static int 1759 devfs_write_f(struct file *fp, struct uio *uio, struct ucred *cred, 1760 int flags, struct thread *td) 1761 { 1762 struct cdev *dev; 1763 int error, ioflag, ref; 1764 ssize_t resid; 1765 struct cdevsw *dsw; 1766 struct file *fpop; 1767 1768 if (uio->uio_resid > DEVFS_IOSIZE_MAX) 1769 return (EINVAL); 1770 fpop = td->td_fpop; 1771 error = devfs_fp_check(fp, &dev, &dsw, &ref); 1772 if (error != 0) { 1773 error = vnops.fo_write(fp, uio, cred, flags, td); 1774 return (error); 1775 } 1776 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", uio->uio_td, td)); 1777 ioflag = fp->f_flag & (O_NONBLOCK | O_DIRECT | O_FSYNC); 1778 if (ioflag & O_DIRECT) 1779 ioflag |= IO_DIRECT; 1780 foffset_lock_uio(fp, uio, flags | FOF_NOLOCK); 1781 1782 resid = uio->uio_resid; 1783 1784 error = dsw->d_write(dev, uio, ioflag); 1785 if (uio->uio_resid != resid || (error == 0 && resid != 0)) { 1786 devfs_timestamp(&dev->si_ctime); 1787 dev->si_mtime = dev->si_ctime; 1788 } 1789 td->td_fpop = fpop; 1790 dev_relthread(dev, ref); 1791 1792 foffset_unlock_uio(fp, uio, flags | FOF_NOLOCK | FOF_NEXTOFF); 1793 return (error); 1794 } 1795 1796 static int 1797 devfs_mmap_f(struct file *fp, vm_map_t map, vm_offset_t *addr, vm_size_t size, 1798 vm_prot_t prot, vm_prot_t cap_maxprot, int flags, vm_ooffset_t foff, 1799 struct thread *td) 1800 { 1801 struct cdev *dev; 1802 struct cdevsw *dsw; 1803 struct mount *mp; 1804 struct vnode *vp; 1805 struct file *fpop; 1806 vm_object_t object; 1807 vm_prot_t maxprot; 1808 int error, ref; 1809 1810 vp = fp->f_vnode; 1811 1812 /* 1813 * Ensure that file and memory protections are 1814 * compatible. 1815 */ 1816 mp = vp->v_mount; 1817 if (mp != NULL && (mp->mnt_flag & MNT_NOEXEC) != 0) { 1818 maxprot = VM_PROT_NONE; 1819 if ((prot & VM_PROT_EXECUTE) != 0) 1820 return (EACCES); 1821 } else 1822 maxprot = VM_PROT_EXECUTE; 1823 if ((fp->f_flag & FREAD) != 0) 1824 maxprot |= VM_PROT_READ; 1825 else if ((prot & VM_PROT_READ) != 0) 1826 return (EACCES); 1827 1828 /* 1829 * If we are sharing potential changes via MAP_SHARED and we 1830 * are trying to get write permission although we opened it 1831 * without asking for it, bail out. 1832 * 1833 * Note that most character devices always share mappings. 1834 * The one exception is that D_MMAP_ANON devices 1835 * (i.e. /dev/zero) permit private writable mappings. 1836 * 1837 * Rely on vm_mmap_cdev() to fail invalid MAP_PRIVATE requests 1838 * as well as updating maxprot to permit writing for 1839 * D_MMAP_ANON devices rather than doing that here. 1840 */ 1841 if ((flags & MAP_SHARED) != 0) { 1842 if ((fp->f_flag & FWRITE) != 0) 1843 maxprot |= VM_PROT_WRITE; 1844 else if ((prot & VM_PROT_WRITE) != 0) 1845 return (EACCES); 1846 } 1847 maxprot &= cap_maxprot; 1848 1849 fpop = td->td_fpop; 1850 error = devfs_fp_check(fp, &dev, &dsw, &ref); 1851 if (error != 0) 1852 return (error); 1853 1854 error = vm_mmap_cdev(td, size, prot, &maxprot, &flags, dev, dsw, &foff, 1855 &object); 1856 td->td_fpop = fpop; 1857 dev_relthread(dev, ref); 1858 if (error != 0) 1859 return (error); 1860 1861 error = vm_mmap_object(map, addr, size, prot, maxprot, flags, object, 1862 foff, FALSE, td); 1863 if (error != 0) 1864 vm_object_deallocate(object); 1865 return (error); 1866 } 1867 1868 dev_t 1869 dev2udev(struct cdev *x) 1870 { 1871 if (x == NULL) 1872 return (NODEV); 1873 return (cdev2priv(x)->cdp_inode); 1874 } 1875 1876 static struct fileops devfs_ops_f = { 1877 .fo_read = devfs_read_f, 1878 .fo_write = devfs_write_f, 1879 .fo_truncate = devfs_truncate_f, 1880 .fo_ioctl = devfs_ioctl_f, 1881 .fo_poll = devfs_poll_f, 1882 .fo_kqfilter = devfs_kqfilter_f, 1883 .fo_stat = devfs_stat_f, 1884 .fo_close = devfs_close_f, 1885 .fo_chmod = vn_chmod, 1886 .fo_chown = vn_chown, 1887 .fo_sendfile = vn_sendfile, 1888 .fo_seek = vn_seek, 1889 .fo_fill_kinfo = vn_fill_kinfo, 1890 .fo_mmap = devfs_mmap_f, 1891 .fo_flags = DFLAG_PASSABLE | DFLAG_SEEKABLE 1892 }; 1893 1894 /* Vops for non-CHR vnodes in /dev. */ 1895 static struct vop_vector devfs_vnodeops = { 1896 .vop_default = &default_vnodeops, 1897 1898 .vop_access = devfs_access, 1899 .vop_getattr = devfs_getattr, 1900 .vop_ioctl = devfs_rioctl, 1901 .vop_lookup = devfs_lookup, 1902 .vop_mknod = devfs_mknod, 1903 .vop_pathconf = devfs_pathconf, 1904 .vop_read = devfs_rread, 1905 .vop_readdir = devfs_readdir, 1906 .vop_readlink = devfs_readlink, 1907 .vop_reclaim = devfs_reclaim, 1908 .vop_remove = devfs_remove, 1909 .vop_revoke = devfs_revoke, 1910 .vop_setattr = devfs_setattr, 1911 #ifdef MAC 1912 .vop_setlabel = devfs_setlabel, 1913 #endif 1914 .vop_symlink = devfs_symlink, 1915 .vop_vptocnp = devfs_vptocnp, 1916 }; 1917 1918 /* Vops for VCHR vnodes in /dev. */ 1919 static struct vop_vector devfs_specops = { 1920 .vop_default = &default_vnodeops, 1921 1922 .vop_access = devfs_access, 1923 .vop_bmap = VOP_PANIC, 1924 .vop_close = devfs_close, 1925 .vop_create = VOP_PANIC, 1926 .vop_fsync = vop_stdfsync, 1927 .vop_getattr = devfs_getattr, 1928 .vop_ioctl = devfs_ioctl, 1929 .vop_link = VOP_PANIC, 1930 .vop_mkdir = VOP_PANIC, 1931 .vop_mknod = VOP_PANIC, 1932 .vop_open = devfs_open, 1933 .vop_pathconf = devfs_pathconf, 1934 .vop_poll = dead_poll, 1935 .vop_print = devfs_print, 1936 .vop_read = dead_read, 1937 .vop_readdir = VOP_PANIC, 1938 .vop_readlink = VOP_PANIC, 1939 .vop_reallocblks = VOP_PANIC, 1940 .vop_reclaim = devfs_reclaim_vchr, 1941 .vop_remove = devfs_remove, 1942 .vop_rename = VOP_PANIC, 1943 .vop_revoke = devfs_revoke, 1944 .vop_rmdir = VOP_PANIC, 1945 .vop_setattr = devfs_setattr, 1946 #ifdef MAC 1947 .vop_setlabel = devfs_setlabel, 1948 #endif 1949 .vop_strategy = VOP_PANIC, 1950 .vop_symlink = VOP_PANIC, 1951 .vop_vptocnp = devfs_vptocnp, 1952 .vop_write = dead_write, 1953 }; 1954 1955 /* 1956 * Our calling convention to the device drivers used to be that we passed 1957 * vnode.h IO_* flags to read()/write(), but we're moving to fcntl.h O_ 1958 * flags instead since that's what open(), close() and ioctl() takes and 1959 * we don't really want vnode.h in device drivers. 1960 * We solved the source compatibility by redefining some vnode flags to 1961 * be the same as the fcntl ones and by sending down the bitwise OR of 1962 * the respective fcntl/vnode flags. These CTASSERTS make sure nobody 1963 * pulls the rug out under this. 1964 */ 1965 CTASSERT(O_NONBLOCK == IO_NDELAY); 1966 CTASSERT(O_FSYNC == IO_SYNC);
Cache object: 07dca40d6b5355e7f6cf28ff51f8a82c
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