1 /* 2 * Copyright (c) 2009 The DragonFly Project. All rights reserved. 3 * 4 * This code is derived from software contributed to The DragonFly Project 5 * by Alex Hornung <ahornung@gmail.com> 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 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 15 * the documentation and/or other materials provided with the 16 * distribution. 17 * 3. Neither the name of The DragonFly Project nor the names of its 18 * contributors may be used to endorse or promote products derived 19 * from this software without specific, prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/time.h> 37 #include <sys/kernel.h> 38 #include <sys/lock.h> 39 #include <sys/fcntl.h> 40 #include <sys/proc.h> 41 #include <sys/priv.h> 42 #include <sys/signalvar.h> 43 #include <sys/vnode.h> 44 #include <sys/uio.h> 45 #include <sys/mount.h> 46 #include <sys/file.h> 47 #include <sys/fcntl.h> 48 #include <sys/namei.h> 49 #include <sys/dirent.h> 50 #include <sys/malloc.h> 51 #include <sys/stat.h> 52 #include <sys/reg.h> 53 #include <vm/vm_pager.h> 54 #include <vm/vm_zone.h> 55 #include <vm/vm_object.h> 56 #include <sys/filio.h> 57 #include <sys/ttycom.h> 58 #include <sys/tty.h> 59 #include <sys/diskslice.h> 60 #include <sys/sysctl.h> 61 #include <sys/devfs.h> 62 #include <sys/pioctl.h> 63 64 #include <machine/limits.h> 65 66 #include <sys/buf2.h> 67 #include <sys/sysref2.h> 68 #include <sys/mplock2.h> 69 #include <vm/vm_page2.h> 70 71 MALLOC_DECLARE(M_DEVFS); 72 #define DEVFS_BADOP (void *)devfs_badop 73 74 static int devfs_badop(struct vop_generic_args *); 75 static int devfs_access(struct vop_access_args *); 76 static int devfs_inactive(struct vop_inactive_args *); 77 static int devfs_reclaim(struct vop_reclaim_args *); 78 static int devfs_readdir(struct vop_readdir_args *); 79 static int devfs_getattr(struct vop_getattr_args *); 80 static int devfs_setattr(struct vop_setattr_args *); 81 static int devfs_readlink(struct vop_readlink_args *); 82 static int devfs_print(struct vop_print_args *); 83 84 static int devfs_nresolve(struct vop_nresolve_args *); 85 static int devfs_nlookupdotdot(struct vop_nlookupdotdot_args *); 86 static int devfs_nsymlink(struct vop_nsymlink_args *); 87 static int devfs_nremove(struct vop_nremove_args *); 88 89 static int devfs_spec_open(struct vop_open_args *); 90 static int devfs_spec_close(struct vop_close_args *); 91 static int devfs_spec_fsync(struct vop_fsync_args *); 92 93 static int devfs_spec_read(struct vop_read_args *); 94 static int devfs_spec_write(struct vop_write_args *); 95 static int devfs_spec_ioctl(struct vop_ioctl_args *); 96 static int devfs_spec_poll(struct vop_poll_args *); 97 static int devfs_spec_kqfilter(struct vop_kqfilter_args *); 98 static int devfs_spec_strategy(struct vop_strategy_args *); 99 static void devfs_spec_strategy_done(struct bio *); 100 static int devfs_spec_freeblks(struct vop_freeblks_args *); 101 static int devfs_spec_bmap(struct vop_bmap_args *); 102 static int devfs_spec_advlock(struct vop_advlock_args *); 103 static void devfs_spec_getpages_iodone(struct bio *); 104 static int devfs_spec_getpages(struct vop_getpages_args *); 105 106 107 static int devfs_specf_close(struct file *); 108 static int devfs_specf_read(struct file *, struct uio *, struct ucred *, int); 109 static int devfs_specf_write(struct file *, struct uio *, struct ucred *, int); 110 static int devfs_specf_stat(struct file *, struct stat *, struct ucred *); 111 static int devfs_specf_kqfilter(struct file *, struct knote *); 112 static int devfs_specf_poll(struct file *, int, struct ucred *); 113 static int devfs_specf_ioctl(struct file *, u_long, caddr_t, 114 struct ucred *, struct sysmsg *); 115 static __inline int sequential_heuristic(struct uio *, struct file *); 116 117 extern struct lock devfs_lock; 118 119 static int mpsafe_reads, mpsafe_writes, mplock_reads, mplock_writes; 120 121 /* 122 * devfs vnode operations for regular files 123 */ 124 struct vop_ops devfs_vnode_norm_vops = { 125 .vop_default = vop_defaultop, 126 .vop_access = devfs_access, 127 .vop_advlock = DEVFS_BADOP, 128 .vop_bmap = DEVFS_BADOP, 129 .vop_close = vop_stdclose, 130 .vop_getattr = devfs_getattr, 131 .vop_inactive = devfs_inactive, 132 .vop_ncreate = DEVFS_BADOP, 133 .vop_nresolve = devfs_nresolve, 134 .vop_nlookupdotdot = devfs_nlookupdotdot, 135 .vop_nlink = DEVFS_BADOP, 136 .vop_nmkdir = DEVFS_BADOP, 137 .vop_nmknod = DEVFS_BADOP, 138 .vop_nremove = devfs_nremove, 139 .vop_nrename = DEVFS_BADOP, 140 .vop_nrmdir = DEVFS_BADOP, 141 .vop_nsymlink = devfs_nsymlink, 142 .vop_open = vop_stdopen, 143 .vop_pathconf = vop_stdpathconf, 144 .vop_print = devfs_print, 145 .vop_read = DEVFS_BADOP, 146 .vop_readdir = devfs_readdir, 147 .vop_readlink = devfs_readlink, 148 .vop_reclaim = devfs_reclaim, 149 .vop_setattr = devfs_setattr, 150 .vop_write = DEVFS_BADOP, 151 .vop_ioctl = DEVFS_BADOP 152 }; 153 154 /* 155 * devfs vnode operations for character devices 156 */ 157 struct vop_ops devfs_vnode_dev_vops = { 158 .vop_default = vop_defaultop, 159 .vop_access = devfs_access, 160 .vop_advlock = devfs_spec_advlock, 161 .vop_bmap = devfs_spec_bmap, 162 .vop_close = devfs_spec_close, 163 .vop_freeblks = devfs_spec_freeblks, 164 .vop_fsync = devfs_spec_fsync, 165 .vop_getattr = devfs_getattr, 166 .vop_getpages = devfs_spec_getpages, 167 .vop_inactive = devfs_inactive, 168 .vop_open = devfs_spec_open, 169 .vop_pathconf = vop_stdpathconf, 170 .vop_print = devfs_print, 171 .vop_poll = devfs_spec_poll, 172 .vop_kqfilter = devfs_spec_kqfilter, 173 .vop_read = devfs_spec_read, 174 .vop_readdir = DEVFS_BADOP, 175 .vop_readlink = DEVFS_BADOP, 176 .vop_reclaim = devfs_reclaim, 177 .vop_setattr = devfs_setattr, 178 .vop_strategy = devfs_spec_strategy, 179 .vop_write = devfs_spec_write, 180 .vop_ioctl = devfs_spec_ioctl 181 }; 182 183 struct vop_ops *devfs_vnode_dev_vops_p = &devfs_vnode_dev_vops; 184 185 struct fileops devfs_dev_fileops = { 186 .fo_read = devfs_specf_read, 187 .fo_write = devfs_specf_write, 188 .fo_ioctl = devfs_specf_ioctl, 189 .fo_poll = devfs_specf_poll, 190 .fo_kqfilter = devfs_specf_kqfilter, 191 .fo_stat = devfs_specf_stat, 192 .fo_close = devfs_specf_close, 193 .fo_shutdown = nofo_shutdown 194 }; 195 196 /* 197 * These two functions are possibly temporary hacks for 198 * devices (aka the pty code) which want to control the 199 * node attributes themselves. 200 * 201 * XXX we may ultimately desire to simply remove the uid/gid/mode 202 * from the node entirely. 203 */ 204 static __inline void 205 node_sync_dev_get(struct devfs_node *node) 206 { 207 cdev_t dev; 208 209 if ((dev = node->d_dev) && (dev->si_flags & SI_OVERRIDE)) { 210 node->uid = dev->si_uid; 211 node->gid = dev->si_gid; 212 node->mode = dev->si_perms; 213 } 214 } 215 216 static __inline void 217 node_sync_dev_set(struct devfs_node *node) 218 { 219 cdev_t dev; 220 221 if ((dev = node->d_dev) && (dev->si_flags & SI_OVERRIDE)) { 222 dev->si_uid = node->uid; 223 dev->si_gid = node->gid; 224 dev->si_perms = node->mode; 225 } 226 } 227 228 /* 229 * generic entry point for unsupported operations 230 */ 231 static int 232 devfs_badop(struct vop_generic_args *ap) 233 { 234 return (EIO); 235 } 236 237 238 static int 239 devfs_access(struct vop_access_args *ap) 240 { 241 struct devfs_node *node = DEVFS_NODE(ap->a_vp); 242 int error; 243 244 if (!devfs_node_is_accessible(node)) 245 return ENOENT; 246 node_sync_dev_get(node); 247 error = vop_helper_access(ap, node->uid, node->gid, 248 node->mode, node->flags); 249 250 return error; 251 } 252 253 254 static int 255 devfs_inactive(struct vop_inactive_args *ap) 256 { 257 struct devfs_node *node = DEVFS_NODE(ap->a_vp); 258 259 if (node == NULL || (node->flags & DEVFS_NODE_LINKED) == 0) 260 vrecycle(ap->a_vp); 261 return 0; 262 } 263 264 265 static int 266 devfs_reclaim(struct vop_reclaim_args *ap) 267 { 268 struct devfs_node *node; 269 struct vnode *vp; 270 int locked; 271 272 /* 273 * Check if it is locked already. if not, we acquire the devfs lock 274 */ 275 if (!(lockstatus(&devfs_lock, curthread)) == LK_EXCLUSIVE) { 276 lockmgr(&devfs_lock, LK_EXCLUSIVE); 277 locked = 1; 278 } else { 279 locked = 0; 280 } 281 282 /* 283 * Get rid of the devfs_node if it is no longer linked into the 284 * topology. 285 */ 286 vp = ap->a_vp; 287 if ((node = DEVFS_NODE(vp)) != NULL) { 288 node->v_node = NULL; 289 if ((node->flags & DEVFS_NODE_LINKED) == 0) 290 devfs_freep(node); 291 } 292 293 if (locked) 294 lockmgr(&devfs_lock, LK_RELEASE); 295 296 /* 297 * v_rdev needs to be properly released using v_release_rdev 298 * Make sure v_data is NULL as well. 299 */ 300 vp->v_data = NULL; 301 v_release_rdev(vp); 302 return 0; 303 } 304 305 306 static int 307 devfs_readdir(struct vop_readdir_args *ap) 308 { 309 struct devfs_node *dnode = DEVFS_NODE(ap->a_vp); 310 struct devfs_node *node; 311 int cookie_index; 312 int ncookies; 313 int error2; 314 int error; 315 int r; 316 off_t *cookies; 317 off_t saveoff; 318 319 devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_readdir() called!\n"); 320 321 if (ap->a_uio->uio_offset < 0 || ap->a_uio->uio_offset > INT_MAX) 322 return (EINVAL); 323 if ((error = vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY)) != 0) 324 return (error); 325 326 if (!devfs_node_is_accessible(dnode)) { 327 vn_unlock(ap->a_vp); 328 return ENOENT; 329 } 330 331 lockmgr(&devfs_lock, LK_EXCLUSIVE); 332 333 saveoff = ap->a_uio->uio_offset; 334 335 if (ap->a_ncookies) { 336 ncookies = ap->a_uio->uio_resid / 16 + 1; /* Why / 16 ?? */ 337 if (ncookies > 256) 338 ncookies = 256; 339 cookies = kmalloc(256 * sizeof(off_t), M_TEMP, M_WAITOK); 340 cookie_index = 0; 341 } else { 342 ncookies = -1; 343 cookies = NULL; 344 cookie_index = 0; 345 } 346 347 nanotime(&dnode->atime); 348 349 if (saveoff == 0) { 350 r = vop_write_dirent(&error, ap->a_uio, dnode->d_dir.d_ino, 351 DT_DIR, 1, "."); 352 if (r) 353 goto done; 354 if (cookies) 355 cookies[cookie_index] = saveoff; 356 saveoff++; 357 cookie_index++; 358 if (cookie_index == ncookies) 359 goto done; 360 } 361 362 if (saveoff == 1) { 363 if (dnode->parent) { 364 r = vop_write_dirent(&error, ap->a_uio, 365 dnode->parent->d_dir.d_ino, 366 DT_DIR, 2, ".."); 367 } else { 368 r = vop_write_dirent(&error, ap->a_uio, 369 dnode->d_dir.d_ino, 370 DT_DIR, 2, ".."); 371 } 372 if (r) 373 goto done; 374 if (cookies) 375 cookies[cookie_index] = saveoff; 376 saveoff++; 377 cookie_index++; 378 if (cookie_index == ncookies) 379 goto done; 380 } 381 382 TAILQ_FOREACH(node, DEVFS_DENODE_HEAD(dnode), link) { 383 if ((node->flags & DEVFS_HIDDEN) || 384 (node->flags & DEVFS_INVISIBLE)) { 385 continue; 386 } 387 388 /* 389 * If the node type is a valid devfs alias, then we make sure that the 390 * target isn't hidden. If it is, we don't show the link in the 391 * directory listing. 392 */ 393 if ((node->node_type == Plink) && (node->link_target != NULL) && 394 (node->link_target->flags & DEVFS_HIDDEN)) 395 continue; 396 397 if (node->cookie < saveoff) 398 continue; 399 400 saveoff = node->cookie; 401 402 error2 = vop_write_dirent(&error, ap->a_uio, node->d_dir.d_ino, 403 node->d_dir.d_type, 404 node->d_dir.d_namlen, 405 node->d_dir.d_name); 406 407 if (error2) 408 break; 409 410 saveoff++; 411 412 if (cookies) 413 cookies[cookie_index] = node->cookie; 414 ++cookie_index; 415 if (cookie_index == ncookies) 416 break; 417 } 418 419 done: 420 lockmgr(&devfs_lock, LK_RELEASE); 421 vn_unlock(ap->a_vp); 422 423 ap->a_uio->uio_offset = saveoff; 424 if (error && cookie_index == 0) { 425 if (cookies) { 426 kfree(cookies, M_TEMP); 427 *ap->a_ncookies = 0; 428 *ap->a_cookies = NULL; 429 } 430 } else { 431 if (cookies) { 432 *ap->a_ncookies = cookie_index; 433 *ap->a_cookies = cookies; 434 } 435 } 436 return (error); 437 } 438 439 440 static int 441 devfs_nresolve(struct vop_nresolve_args *ap) 442 { 443 struct devfs_node *dnode = DEVFS_NODE(ap->a_dvp); 444 struct devfs_node *node, *found = NULL; 445 struct namecache *ncp; 446 struct vnode *vp = NULL; 447 int error = 0; 448 int len; 449 int depth; 450 451 ncp = ap->a_nch->ncp; 452 len = ncp->nc_nlen; 453 454 if (!devfs_node_is_accessible(dnode)) 455 return ENOENT; 456 457 lockmgr(&devfs_lock, LK_EXCLUSIVE); 458 459 if ((dnode->node_type != Proot) && (dnode->node_type != Pdir)) { 460 error = ENOENT; 461 cache_setvp(ap->a_nch, NULL); 462 goto out; 463 } 464 465 TAILQ_FOREACH(node, DEVFS_DENODE_HEAD(dnode), link) { 466 if (len == node->d_dir.d_namlen) { 467 if (!memcmp(ncp->nc_name, node->d_dir.d_name, len)) { 468 found = node; 469 break; 470 } 471 } 472 } 473 474 if (found) { 475 depth = 0; 476 while ((found->node_type == Plink) && (found->link_target)) { 477 if (depth >= 8) { 478 devfs_debug(DEVFS_DEBUG_SHOW, "Recursive link or depth >= 8"); 479 break; 480 } 481 482 found = found->link_target; 483 ++depth; 484 } 485 486 if (!(found->flags & DEVFS_HIDDEN)) 487 devfs_allocv(/*ap->a_dvp->v_mount, */ &vp, found); 488 } 489 490 if (vp == NULL) { 491 error = ENOENT; 492 cache_setvp(ap->a_nch, NULL); 493 goto out; 494 495 } 496 KKASSERT(vp); 497 vn_unlock(vp); 498 cache_setvp(ap->a_nch, vp); 499 vrele(vp); 500 out: 501 lockmgr(&devfs_lock, LK_RELEASE); 502 503 return error; 504 } 505 506 507 static int 508 devfs_nlookupdotdot(struct vop_nlookupdotdot_args *ap) 509 { 510 struct devfs_node *dnode = DEVFS_NODE(ap->a_dvp); 511 512 *ap->a_vpp = NULL; 513 if (!devfs_node_is_accessible(dnode)) 514 return ENOENT; 515 516 lockmgr(&devfs_lock, LK_EXCLUSIVE); 517 if (dnode->parent != NULL) { 518 devfs_allocv(ap->a_vpp, dnode->parent); 519 vn_unlock(*ap->a_vpp); 520 } 521 lockmgr(&devfs_lock, LK_RELEASE); 522 523 return ((*ap->a_vpp == NULL) ? ENOENT : 0); 524 } 525 526 527 static int 528 devfs_getattr(struct vop_getattr_args *ap) 529 { 530 struct devfs_node *node = DEVFS_NODE(ap->a_vp); 531 struct vattr *vap = ap->a_vap; 532 struct partinfo pinfo; 533 int error = 0; 534 535 #if 0 536 if (!devfs_node_is_accessible(node)) 537 return ENOENT; 538 #endif 539 node_sync_dev_get(node); 540 541 lockmgr(&devfs_lock, LK_EXCLUSIVE); 542 543 /* start by zeroing out the attributes */ 544 VATTR_NULL(vap); 545 546 /* next do all the common fields */ 547 vap->va_type = ap->a_vp->v_type; 548 vap->va_mode = node->mode; 549 vap->va_fileid = DEVFS_NODE(ap->a_vp)->d_dir.d_ino ; 550 vap->va_flags = 0; /* XXX: what should this be? */ 551 vap->va_blocksize = DEV_BSIZE; 552 vap->va_bytes = vap->va_size = sizeof(struct devfs_node); 553 554 vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid.val[0]; 555 556 vap->va_atime = node->atime; 557 vap->va_mtime = node->mtime; 558 vap->va_ctime = node->ctime; 559 560 vap->va_nlink = 1; /* number of references to file */ 561 562 vap->va_uid = node->uid; 563 vap->va_gid = node->gid; 564 565 vap->va_rmajor = 0; 566 vap->va_rminor = 0; 567 568 if ((node->node_type == Pdev) && node->d_dev) { 569 reference_dev(node->d_dev); 570 vap->va_rminor = node->d_dev->si_uminor; 571 release_dev(node->d_dev); 572 } 573 574 /* For a softlink the va_size is the length of the softlink */ 575 if (node->symlink_name != 0) { 576 vap->va_bytes = vap->va_size = node->symlink_namelen; 577 } 578 579 /* 580 * For a disk-type device, va_size is the size of the underlying 581 * device, so that lseek() works properly. 582 */ 583 if ((node->d_dev) && (dev_dflags(node->d_dev) & D_DISK)) { 584 bzero(&pinfo, sizeof(pinfo)); 585 error = dev_dioctl(node->d_dev, DIOCGPART, (void *)&pinfo, 586 0, proc0.p_ucred, NULL); 587 if ((error == 0) && (pinfo.media_blksize != 0)) { 588 vap->va_size = pinfo.media_size; 589 } else { 590 vap->va_size = 0; 591 error = 0; 592 } 593 } 594 595 lockmgr(&devfs_lock, LK_RELEASE); 596 597 return (error); 598 } 599 600 601 static int 602 devfs_setattr(struct vop_setattr_args *ap) 603 { 604 struct devfs_node *node = DEVFS_NODE(ap->a_vp); 605 struct vattr *vap; 606 int error = 0; 607 608 if (!devfs_node_is_accessible(node)) 609 return ENOENT; 610 node_sync_dev_get(node); 611 612 lockmgr(&devfs_lock, LK_EXCLUSIVE); 613 614 vap = ap->a_vap; 615 616 if (vap->va_uid != (uid_t)VNOVAL) { 617 if ((ap->a_cred->cr_uid != node->uid) && 618 (!groupmember(node->gid, ap->a_cred))) { 619 error = priv_check(curthread, PRIV_VFS_CHOWN); 620 if (error) 621 goto out; 622 } 623 node->uid = vap->va_uid; 624 } 625 626 if (vap->va_gid != (uid_t)VNOVAL) { 627 if ((ap->a_cred->cr_uid != node->uid) && 628 (!groupmember(node->gid, ap->a_cred))) { 629 error = priv_check(curthread, PRIV_VFS_CHOWN); 630 if (error) 631 goto out; 632 } 633 node->gid = vap->va_gid; 634 } 635 636 if (vap->va_mode != (mode_t)VNOVAL) { 637 if (ap->a_cred->cr_uid != node->uid) { 638 error = priv_check(curthread, PRIV_VFS_ADMIN); 639 if (error) 640 goto out; 641 } 642 node->mode = vap->va_mode; 643 } 644 645 out: 646 node_sync_dev_set(node); 647 nanotime(&node->ctime); 648 lockmgr(&devfs_lock, LK_RELEASE); 649 650 return error; 651 } 652 653 654 static int 655 devfs_readlink(struct vop_readlink_args *ap) 656 { 657 struct devfs_node *node = DEVFS_NODE(ap->a_vp); 658 int ret; 659 660 if (!devfs_node_is_accessible(node)) 661 return ENOENT; 662 663 lockmgr(&devfs_lock, LK_EXCLUSIVE); 664 ret = uiomove(node->symlink_name, node->symlink_namelen, ap->a_uio); 665 lockmgr(&devfs_lock, LK_RELEASE); 666 667 return ret; 668 } 669 670 671 static int 672 devfs_print(struct vop_print_args *ap) 673 { 674 return (0); 675 } 676 677 678 static int 679 devfs_nsymlink(struct vop_nsymlink_args *ap) 680 { 681 struct devfs_node *dnode = DEVFS_NODE(ap->a_dvp); 682 struct devfs_node *node; 683 size_t targetlen; 684 685 if (!devfs_node_is_accessible(dnode)) 686 return ENOENT; 687 688 ap->a_vap->va_type = VLNK; 689 690 if ((dnode->node_type != Proot) && (dnode->node_type != Pdir)) 691 goto out; 692 693 lockmgr(&devfs_lock, LK_EXCLUSIVE); 694 devfs_allocvp(ap->a_dvp->v_mount, ap->a_vpp, Plink, 695 ap->a_nch->ncp->nc_name, dnode, NULL); 696 697 targetlen = strlen(ap->a_target); 698 if (*ap->a_vpp) { 699 node = DEVFS_NODE(*ap->a_vpp); 700 node->flags |= DEVFS_USER_CREATED; 701 node->symlink_namelen = targetlen; 702 node->symlink_name = kmalloc(targetlen + 1, M_DEVFS, M_WAITOK); 703 memcpy(node->symlink_name, ap->a_target, targetlen); 704 node->symlink_name[targetlen] = '\0'; 705 cache_setunresolved(ap->a_nch); 706 cache_setvp(ap->a_nch, *ap->a_vpp); 707 } 708 lockmgr(&devfs_lock, LK_RELEASE); 709 out: 710 return ((*ap->a_vpp == NULL) ? ENOTDIR : 0); 711 } 712 713 714 static int 715 devfs_nremove(struct vop_nremove_args *ap) 716 { 717 struct devfs_node *dnode = DEVFS_NODE(ap->a_dvp); 718 struct devfs_node *node; 719 struct namecache *ncp; 720 int error = ENOENT; 721 722 ncp = ap->a_nch->ncp; 723 724 if (!devfs_node_is_accessible(dnode)) 725 return ENOENT; 726 727 lockmgr(&devfs_lock, LK_EXCLUSIVE); 728 729 if ((dnode->node_type != Proot) && (dnode->node_type != Pdir)) 730 goto out; 731 732 TAILQ_FOREACH(node, DEVFS_DENODE_HEAD(dnode), link) { 733 if (ncp->nc_nlen != node->d_dir.d_namlen) 734 continue; 735 if (memcmp(ncp->nc_name, node->d_dir.d_name, ncp->nc_nlen)) 736 continue; 737 738 /* 739 * only allow removal of user created stuff (e.g. symlinks) 740 */ 741 if ((node->flags & DEVFS_USER_CREATED) == 0) { 742 error = EPERM; 743 goto out; 744 } else { 745 if (node->v_node) 746 cache_inval_vp(node->v_node, CINV_DESTROY); 747 devfs_unlinkp(node); 748 error = 0; 749 break; 750 } 751 } 752 753 cache_setunresolved(ap->a_nch); 754 cache_setvp(ap->a_nch, NULL); 755 756 out: 757 lockmgr(&devfs_lock, LK_RELEASE); 758 return error; 759 } 760 761 762 static int 763 devfs_spec_open(struct vop_open_args *ap) 764 { 765 struct vnode *vp = ap->a_vp; 766 struct vnode *orig_vp = NULL; 767 struct devfs_node *node = DEVFS_NODE(vp); 768 struct devfs_node *newnode; 769 cdev_t dev, ndev = NULL; 770 int error = 0; 771 772 if (node) { 773 if (node->d_dev == NULL) 774 return ENXIO; 775 if (!devfs_node_is_accessible(node)) 776 return ENOENT; 777 } 778 779 if ((dev = vp->v_rdev) == NULL) 780 return ENXIO; 781 782 if (node && ap->a_fp) { 783 devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_spec_open: -1.1-\n"); 784 lockmgr(&devfs_lock, LK_EXCLUSIVE); 785 786 ndev = devfs_clone(dev, node->d_dir.d_name, node->d_dir.d_namlen, 787 ap->a_mode, ap->a_cred); 788 if (ndev != NULL) { 789 newnode = devfs_create_device_node( 790 DEVFS_MNTDATA(vp->v_mount)->root_node, 791 ndev, NULL, NULL); 792 /* XXX: possibly destroy device if this happens */ 793 794 if (newnode != NULL) { 795 dev = ndev; 796 devfs_link_dev(dev); 797 798 devfs_debug(DEVFS_DEBUG_DEBUG, 799 "parent here is: %s, node is: |%s|\n", 800 ((node->parent->node_type == Proot) ? 801 "ROOT!" : node->parent->d_dir.d_name), 802 newnode->d_dir.d_name); 803 devfs_debug(DEVFS_DEBUG_DEBUG, 804 "test: %s\n", 805 ((struct devfs_node *)(TAILQ_LAST(DEVFS_DENODE_HEAD(node->parent), devfs_node_head)))->d_dir.d_name); 806 807 /* 808 * orig_vp is set to the original vp if we cloned. 809 */ 810 /* node->flags |= DEVFS_CLONED; */ 811 devfs_allocv(&vp, newnode); 812 orig_vp = ap->a_vp; 813 ap->a_vp = vp; 814 } 815 } 816 lockmgr(&devfs_lock, LK_RELEASE); 817 } 818 819 devfs_debug(DEVFS_DEBUG_DEBUG, 820 "devfs_spec_open() called on %s! \n", 821 dev->si_name); 822 823 /* 824 * Make this field valid before any I/O in ->d_open 825 */ 826 if (!dev->si_iosize_max) 827 dev->si_iosize_max = DFLTPHYS; 828 829 if (dev_dflags(dev) & D_TTY) 830 vsetflags(vp, VISTTY); 831 832 vn_unlock(vp); 833 error = dev_dopen(dev, ap->a_mode, S_IFCHR, ap->a_cred); 834 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 835 836 /* 837 * Clean up any cloned vp if we error out. 838 */ 839 if (error) { 840 if (orig_vp) { 841 vput(vp); 842 ap->a_vp = orig_vp; 843 /* orig_vp = NULL; */ 844 } 845 return error; 846 } 847 848 /* 849 * This checks if the disk device is going to be opened for writing. 850 * It will be only allowed in the cases where securelevel permits it 851 * and it's not mounted R/W. 852 */ 853 if ((dev_dflags(dev) & D_DISK) && (ap->a_mode & FWRITE) && 854 (ap->a_cred != FSCRED)) { 855 856 /* Very secure mode. No open for writing allowed */ 857 if (securelevel >= 2) 858 return EPERM; 859 860 /* 861 * If it is mounted R/W, do not allow to open for writing. 862 * In the case it's mounted read-only but securelevel 863 * is >= 1, then do not allow opening for writing either. 864 */ 865 if (vfs_mountedon(vp)) { 866 if (!(dev->si_mountpoint->mnt_flag & MNT_RDONLY)) 867 return EBUSY; 868 else if (securelevel >= 1) 869 return EPERM; 870 } 871 } 872 873 if (dev_dflags(dev) & D_TTY) { 874 if (dev->si_tty) { 875 struct tty *tp; 876 tp = dev->si_tty; 877 if (!tp->t_stop) { 878 devfs_debug(DEVFS_DEBUG_DEBUG, 879 "devfs: no t_stop\n"); 880 tp->t_stop = nottystop; 881 } 882 } 883 } 884 885 886 if (vn_isdisk(vp, NULL)) { 887 if (!dev->si_bsize_phys) 888 dev->si_bsize_phys = DEV_BSIZE; 889 vinitvmio(vp, IDX_TO_OFF(INT_MAX), PAGE_SIZE, -1); 890 } 891 892 vop_stdopen(ap); 893 #if 0 894 if (node) 895 nanotime(&node->atime); 896 #endif 897 898 if (orig_vp) 899 vn_unlock(vp); 900 901 /* Ugly pty magic, to make pty devices appear once they are opened */ 902 if (node && (node->flags & DEVFS_PTY) == DEVFS_PTY) 903 node->flags &= ~DEVFS_INVISIBLE; 904 905 if (ap->a_fp) { 906 ap->a_fp->f_type = DTYPE_VNODE; 907 ap->a_fp->f_flag = ap->a_mode & FMASK; 908 ap->a_fp->f_ops = &devfs_dev_fileops; 909 ap->a_fp->f_data = vp; 910 } 911 912 return 0; 913 } 914 915 916 static int 917 devfs_spec_close(struct vop_close_args *ap) 918 { 919 struct devfs_node *node = DEVFS_NODE(ap->a_vp); 920 struct proc *p = curproc; 921 struct vnode *vp = ap->a_vp; 922 cdev_t dev = vp->v_rdev; 923 int error = 0; 924 int needrelock; 925 926 devfs_debug(DEVFS_DEBUG_DEBUG, 927 "devfs_spec_close() called on %s! \n", 928 dev->si_name); 929 930 /* 931 * A couple of hacks for devices and tty devices. The 932 * vnode ref count cannot be used to figure out the 933 * last close, but we can use v_opencount now that 934 * revoke works properly. 935 * 936 * Detect the last close on a controlling terminal and clear 937 * the session (half-close). 938 */ 939 if (dev) 940 reference_dev(dev); 941 942 if (p && vp->v_opencount <= 1 && vp == p->p_session->s_ttyvp) { 943 p->p_session->s_ttyvp = NULL; 944 vrele(vp); 945 } 946 947 /* 948 * Vnodes can be opened and closed multiple times. Do not really 949 * close the device unless (1) it is being closed forcibly, 950 * (2) the device wants to track closes, or (3) this is the last 951 * vnode doing its last close on the device. 952 * 953 * XXX the VXLOCK (force close) case can leave vnodes referencing 954 * a closed device. This might not occur now that our revoke is 955 * fixed. 956 */ 957 devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_spec_close() -1- \n"); 958 if (dev && ((vp->v_flag & VRECLAIMED) || 959 (dev_dflags(dev) & D_TRACKCLOSE) || 960 (vp->v_opencount == 1))) { 961 /* 962 * Unlock around dev_dclose() 963 */ 964 needrelock = 0; 965 if (vn_islocked(vp)) { 966 needrelock = 1; 967 vn_unlock(vp); 968 } 969 error = dev_dclose(dev, ap->a_fflag, S_IFCHR); 970 971 /* 972 * Ugly pty magic, to make pty devices disappear again once 973 * they are closed 974 */ 975 if (node && (node->flags & DEVFS_PTY) == DEVFS_PTY) 976 node->flags |= DEVFS_INVISIBLE; 977 978 if (needrelock) 979 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 980 } else { 981 error = 0; 982 } 983 devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_spec_close() -2- \n"); 984 985 /* 986 * Track the actual opens and closes on the vnode. The last close 987 * disassociates the rdev. If the rdev is already disassociated or 988 * the opencount is already 0, the vnode might have been revoked 989 * and no further opencount tracking occurs. 990 */ 991 if (dev) 992 release_dev(dev); 993 if (vp->v_opencount > 0) 994 vop_stdclose(ap); 995 return(error); 996 997 } 998 999 1000 static int 1001 devfs_specf_close(struct file *fp) 1002 { 1003 struct vnode *vp = (struct vnode *)fp->f_data; 1004 int error; 1005 1006 get_mplock(); 1007 fp->f_ops = &badfileops; 1008 error = vn_close(vp, fp->f_flag); 1009 rel_mplock(); 1010 1011 return (error); 1012 } 1013 1014 1015 /* 1016 * Device-optimized file table vnode read routine. 1017 * 1018 * This bypasses the VOP table and talks directly to the device. Most 1019 * filesystems just route to specfs and can make this optimization. 1020 * 1021 * MPALMOSTSAFE - acquires mplock 1022 */ 1023 static int 1024 devfs_specf_read(struct file *fp, struct uio *uio, 1025 struct ucred *cred, int flags) 1026 { 1027 struct devfs_node *node; 1028 struct vnode *vp; 1029 int ioflag; 1030 int error; 1031 cdev_t dev; 1032 1033 KASSERT(uio->uio_td == curthread, 1034 ("uio_td %p is not td %p", uio->uio_td, curthread)); 1035 1036 if (uio->uio_resid == 0) 1037 return 0; 1038 1039 vp = (struct vnode *)fp->f_data; 1040 if (vp == NULL || vp->v_type == VBAD) 1041 return EBADF; 1042 1043 node = DEVFS_NODE(vp); 1044 1045 if ((dev = vp->v_rdev) == NULL) 1046 return EBADF; 1047 1048 /* only acquire mplock for devices that require it */ 1049 if (!(dev_dflags(dev) & D_MPSAFE_READ)) { 1050 atomic_add_int(&mplock_reads, 1); 1051 get_mplock(); 1052 } else { 1053 atomic_add_int(&mpsafe_reads, 1); 1054 } 1055 1056 reference_dev(dev); 1057 1058 if ((flags & O_FOFFSET) == 0) 1059 uio->uio_offset = fp->f_offset; 1060 1061 ioflag = 0; 1062 if (flags & O_FBLOCKING) { 1063 /* ioflag &= ~IO_NDELAY; */ 1064 } else if (flags & O_FNONBLOCKING) { 1065 ioflag |= IO_NDELAY; 1066 } else if (fp->f_flag & FNONBLOCK) { 1067 ioflag |= IO_NDELAY; 1068 } 1069 if (flags & O_FBUFFERED) { 1070 /* ioflag &= ~IO_DIRECT; */ 1071 } else if (flags & O_FUNBUFFERED) { 1072 ioflag |= IO_DIRECT; 1073 } else if (fp->f_flag & O_DIRECT) { 1074 ioflag |= IO_DIRECT; 1075 } 1076 ioflag |= sequential_heuristic(uio, fp); 1077 1078 error = dev_dread(dev, uio, ioflag); 1079 1080 release_dev(dev); 1081 if (node) 1082 nanotime(&node->atime); 1083 if ((flags & O_FOFFSET) == 0) 1084 fp->f_offset = uio->uio_offset; 1085 fp->f_nextoff = uio->uio_offset; 1086 1087 if (!(dev_dflags(dev) & D_MPSAFE_READ)) 1088 rel_mplock(); 1089 1090 return (error); 1091 } 1092 1093 1094 static int 1095 devfs_specf_write(struct file *fp, struct uio *uio, 1096 struct ucred *cred, int flags) 1097 { 1098 struct devfs_node *node; 1099 struct vnode *vp; 1100 int ioflag; 1101 int error; 1102 cdev_t dev; 1103 1104 KASSERT(uio->uio_td == curthread, 1105 ("uio_td %p is not p %p", uio->uio_td, curthread)); 1106 1107 vp = (struct vnode *)fp->f_data; 1108 if (vp == NULL || vp->v_type == VBAD) 1109 return EBADF; 1110 1111 node = DEVFS_NODE(vp); 1112 1113 if (vp->v_type == VREG) 1114 bwillwrite(uio->uio_resid); 1115 1116 vp = (struct vnode *)fp->f_data; 1117 1118 if ((dev = vp->v_rdev) == NULL) 1119 return EBADF; 1120 1121 /* only acquire mplock for devices that require it */ 1122 if (!(dev_dflags(dev) & D_MPSAFE_WRITE)) { 1123 atomic_add_int(&mplock_writes, 1); 1124 get_mplock(); 1125 } else { 1126 atomic_add_int(&mpsafe_writes, 1); 1127 } 1128 1129 reference_dev(dev); 1130 1131 if ((flags & O_FOFFSET) == 0) 1132 uio->uio_offset = fp->f_offset; 1133 1134 ioflag = IO_UNIT; 1135 if (vp->v_type == VREG && 1136 ((fp->f_flag & O_APPEND) || (flags & O_FAPPEND))) { 1137 ioflag |= IO_APPEND; 1138 } 1139 1140 if (flags & O_FBLOCKING) { 1141 /* ioflag &= ~IO_NDELAY; */ 1142 } else if (flags & O_FNONBLOCKING) { 1143 ioflag |= IO_NDELAY; 1144 } else if (fp->f_flag & FNONBLOCK) { 1145 ioflag |= IO_NDELAY; 1146 } 1147 if (flags & O_FBUFFERED) { 1148 /* ioflag &= ~IO_DIRECT; */ 1149 } else if (flags & O_FUNBUFFERED) { 1150 ioflag |= IO_DIRECT; 1151 } else if (fp->f_flag & O_DIRECT) { 1152 ioflag |= IO_DIRECT; 1153 } 1154 if (flags & O_FASYNCWRITE) { 1155 /* ioflag &= ~IO_SYNC; */ 1156 } else if (flags & O_FSYNCWRITE) { 1157 ioflag |= IO_SYNC; 1158 } else if (fp->f_flag & O_FSYNC) { 1159 ioflag |= IO_SYNC; 1160 } 1161 1162 if (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS)) 1163 ioflag |= IO_SYNC; 1164 ioflag |= sequential_heuristic(uio, fp); 1165 1166 error = dev_dwrite(dev, uio, ioflag); 1167 1168 release_dev(dev); 1169 if (node) { 1170 nanotime(&node->atime); 1171 nanotime(&node->mtime); 1172 } 1173 1174 if ((flags & O_FOFFSET) == 0) 1175 fp->f_offset = uio->uio_offset; 1176 fp->f_nextoff = uio->uio_offset; 1177 1178 if (!(dev_dflags(dev) & D_MPSAFE_WRITE)) 1179 rel_mplock(); 1180 return (error); 1181 } 1182 1183 1184 static int 1185 devfs_specf_stat(struct file *fp, struct stat *sb, struct ucred *cred) 1186 { 1187 struct vnode *vp; 1188 struct vattr vattr; 1189 struct vattr *vap; 1190 u_short mode; 1191 cdev_t dev; 1192 int error; 1193 1194 vp = (struct vnode *)fp->f_data; 1195 if (vp == NULL || vp->v_type == VBAD) 1196 return EBADF; 1197 1198 error = vn_stat(vp, sb, cred); 1199 if (error) 1200 return (error); 1201 1202 vap = &vattr; 1203 error = VOP_GETATTR(vp, vap); 1204 if (error) 1205 return (error); 1206 1207 /* 1208 * Zero the spare stat fields 1209 */ 1210 sb->st_lspare = 0; 1211 sb->st_qspare1 = 0; 1212 sb->st_qspare2 = 0; 1213 1214 /* 1215 * Copy from vattr table ... or not in case it's a cloned device 1216 */ 1217 if (vap->va_fsid != VNOVAL) 1218 sb->st_dev = vap->va_fsid; 1219 else 1220 sb->st_dev = vp->v_mount->mnt_stat.f_fsid.val[0]; 1221 1222 sb->st_ino = vap->va_fileid; 1223 1224 mode = vap->va_mode; 1225 mode |= S_IFCHR; 1226 sb->st_mode = mode; 1227 1228 if (vap->va_nlink > (nlink_t)-1) 1229 sb->st_nlink = (nlink_t)-1; 1230 else 1231 sb->st_nlink = vap->va_nlink; 1232 1233 sb->st_uid = vap->va_uid; 1234 sb->st_gid = vap->va_gid; 1235 sb->st_rdev = dev2udev(DEVFS_NODE(vp)->d_dev); 1236 sb->st_size = vap->va_bytes; 1237 sb->st_atimespec = vap->va_atime; 1238 sb->st_mtimespec = vap->va_mtime; 1239 sb->st_ctimespec = vap->va_ctime; 1240 1241 /* 1242 * A VCHR and VBLK device may track the last access and last modified 1243 * time independantly of the filesystem. This is particularly true 1244 * because device read and write calls may bypass the filesystem. 1245 */ 1246 if (vp->v_type == VCHR || vp->v_type == VBLK) { 1247 dev = vp->v_rdev; 1248 if (dev != NULL) { 1249 if (dev->si_lastread) { 1250 sb->st_atimespec.tv_sec = dev->si_lastread; 1251 sb->st_atimespec.tv_nsec = 0; 1252 } 1253 if (dev->si_lastwrite) { 1254 sb->st_atimespec.tv_sec = dev->si_lastwrite; 1255 sb->st_atimespec.tv_nsec = 0; 1256 } 1257 } 1258 } 1259 1260 /* 1261 * According to www.opengroup.org, the meaning of st_blksize is 1262 * "a filesystem-specific preferred I/O block size for this 1263 * object. In some filesystem types, this may vary from file 1264 * to file" 1265 * Default to PAGE_SIZE after much discussion. 1266 */ 1267 1268 sb->st_blksize = PAGE_SIZE; 1269 1270 sb->st_flags = vap->va_flags; 1271 1272 error = priv_check_cred(cred, PRIV_VFS_GENERATION, 0); 1273 if (error) 1274 sb->st_gen = 0; 1275 else 1276 sb->st_gen = (u_int32_t)vap->va_gen; 1277 1278 sb->st_blocks = vap->va_bytes / S_BLKSIZE; 1279 1280 return (0); 1281 } 1282 1283 1284 static int 1285 devfs_specf_kqfilter(struct file *fp, struct knote *kn) 1286 { 1287 struct vnode *vp; 1288 int error; 1289 cdev_t dev; 1290 1291 get_mplock(); 1292 1293 vp = (struct vnode *)fp->f_data; 1294 if (vp == NULL || vp->v_type == VBAD) { 1295 error = EBADF; 1296 goto done; 1297 } 1298 if ((dev = vp->v_rdev) == NULL) { 1299 error = EBADF; 1300 goto done; 1301 } 1302 reference_dev(dev); 1303 1304 error = dev_dkqfilter(dev, kn); 1305 1306 release_dev(dev); 1307 1308 done: 1309 rel_mplock(); 1310 return (error); 1311 } 1312 1313 1314 static int 1315 devfs_specf_poll(struct file *fp, int events, struct ucred *cred) 1316 { 1317 struct devfs_node *node; 1318 struct vnode *vp; 1319 int error; 1320 cdev_t dev; 1321 1322 get_mplock(); 1323 1324 vp = (struct vnode *)fp->f_data; 1325 if (vp == NULL || vp->v_type == VBAD) { 1326 error = EBADF; 1327 goto done; 1328 } 1329 node = DEVFS_NODE(vp); 1330 1331 if ((dev = vp->v_rdev) == NULL) { 1332 error = EBADF; 1333 goto done; 1334 } 1335 reference_dev(dev); 1336 error = dev_dpoll(dev, events); 1337 1338 release_dev(dev); 1339 1340 #if 0 1341 if (node) 1342 nanotime(&node->atime); 1343 #endif 1344 done: 1345 rel_mplock(); 1346 return (error); 1347 } 1348 1349 1350 /* 1351 * MPALMOSTSAFE - acquires mplock 1352 */ 1353 static int 1354 devfs_specf_ioctl(struct file *fp, u_long com, caddr_t data, 1355 struct ucred *ucred, struct sysmsg *msg) 1356 { 1357 struct devfs_node *node; 1358 struct vnode *vp; 1359 struct vnode *ovp; 1360 cdev_t dev; 1361 int error; 1362 struct fiodname_args *name_args; 1363 size_t namlen; 1364 const char *name; 1365 1366 vp = ((struct vnode *)fp->f_data); 1367 1368 if ((dev = vp->v_rdev) == NULL) 1369 return EBADF; /* device was revoked */ 1370 1371 reference_dev(dev); 1372 1373 node = DEVFS_NODE(vp); 1374 1375 devfs_debug(DEVFS_DEBUG_DEBUG, 1376 "devfs_specf_ioctl() called! for dev %s\n", 1377 dev->si_name); 1378 1379 if (com == FIODTYPE) { 1380 *(int *)data = dev_dflags(dev) & D_TYPEMASK; 1381 error = 0; 1382 goto out; 1383 } else if (com == FIODNAME) { 1384 name_args = (struct fiodname_args *)data; 1385 name = dev->si_name; 1386 namlen = strlen(name) + 1; 1387 1388 devfs_debug(DEVFS_DEBUG_DEBUG, 1389 "ioctl, got: FIODNAME for %s\n", name); 1390 1391 if (namlen <= name_args->len) 1392 error = copyout(dev->si_name, name_args->name, namlen); 1393 else 1394 error = EINVAL; 1395 1396 devfs_debug(DEVFS_DEBUG_DEBUG, 1397 "ioctl stuff: error: %d\n", error); 1398 goto out; 1399 } 1400 1401 /* only acquire mplock for devices that require it */ 1402 if (!(dev_dflags(dev) & D_MPSAFE_IOCTL)) 1403 get_mplock(); 1404 1405 error = dev_dioctl(dev, com, data, fp->f_flag, ucred, msg); 1406 1407 #if 0 1408 if (node) { 1409 nanotime(&node->atime); 1410 nanotime(&node->mtime); 1411 } 1412 #endif 1413 1414 if (!(dev_dflags(dev) & D_MPSAFE_IOCTL)) 1415 rel_mplock(); 1416 1417 if (com == TIOCSCTTY) { 1418 devfs_debug(DEVFS_DEBUG_DEBUG, 1419 "devfs_specf_ioctl: got TIOCSCTTY on %s\n", 1420 dev->si_name); 1421 } 1422 if (error == 0 && com == TIOCSCTTY) { 1423 struct proc *p = curthread->td_proc; 1424 struct session *sess; 1425 1426 devfs_debug(DEVFS_DEBUG_DEBUG, 1427 "devfs_specf_ioctl: dealing with TIOCSCTTY on %s\n", 1428 dev->si_name); 1429 if (p == NULL) { 1430 error = ENOTTY; 1431 goto out; 1432 } 1433 sess = p->p_session; 1434 1435 /* 1436 * Do nothing if reassigning same control tty 1437 */ 1438 if (sess->s_ttyvp == vp) { 1439 error = 0; 1440 goto out; 1441 } 1442 1443 /* 1444 * Get rid of reference to old control tty 1445 */ 1446 ovp = sess->s_ttyvp; 1447 vref(vp); 1448 sess->s_ttyvp = vp; 1449 if (ovp) 1450 vrele(ovp); 1451 } 1452 1453 out: 1454 release_dev(dev); 1455 devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_specf_ioctl() finished! \n"); 1456 return (error); 1457 } 1458 1459 1460 static int 1461 devfs_spec_fsync(struct vop_fsync_args *ap) 1462 { 1463 struct vnode *vp = ap->a_vp; 1464 int error; 1465 1466 if (!vn_isdisk(vp, NULL)) 1467 return (0); 1468 1469 /* 1470 * Flush all dirty buffers associated with a block device. 1471 */ 1472 error = vfsync(vp, ap->a_waitfor, 10000, NULL, NULL); 1473 return (error); 1474 } 1475 1476 static int 1477 devfs_spec_read(struct vop_read_args *ap) 1478 { 1479 struct devfs_node *node; 1480 struct vnode *vp; 1481 struct uio *uio; 1482 cdev_t dev; 1483 int error; 1484 1485 vp = ap->a_vp; 1486 dev = vp->v_rdev; 1487 uio = ap->a_uio; 1488 node = DEVFS_NODE(vp); 1489 1490 if (dev == NULL) /* device was revoked */ 1491 return (EBADF); 1492 if (uio->uio_resid == 0) 1493 return (0); 1494 1495 vn_unlock(vp); 1496 error = dev_dread(dev, uio, ap->a_ioflag); 1497 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1498 1499 if (node) 1500 nanotime(&node->atime); 1501 1502 return (error); 1503 } 1504 1505 /* 1506 * Vnode op for write 1507 * 1508 * spec_write(struct vnode *a_vp, struct uio *a_uio, int a_ioflag, 1509 * struct ucred *a_cred) 1510 */ 1511 static int 1512 devfs_spec_write(struct vop_write_args *ap) 1513 { 1514 struct devfs_node *node; 1515 struct vnode *vp; 1516 struct uio *uio; 1517 cdev_t dev; 1518 int error; 1519 1520 vp = ap->a_vp; 1521 dev = vp->v_rdev; 1522 uio = ap->a_uio; 1523 node = DEVFS_NODE(vp); 1524 1525 KKASSERT(uio->uio_segflg != UIO_NOCOPY); 1526 1527 if (dev == NULL) /* device was revoked */ 1528 return (EBADF); 1529 1530 vn_unlock(vp); 1531 error = dev_dwrite(dev, uio, ap->a_ioflag); 1532 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1533 1534 if (node) { 1535 nanotime(&node->atime); 1536 nanotime(&node->mtime); 1537 } 1538 1539 return (error); 1540 } 1541 1542 /* 1543 * Device ioctl operation. 1544 * 1545 * spec_ioctl(struct vnode *a_vp, int a_command, caddr_t a_data, 1546 * int a_fflag, struct ucred *a_cred, struct sysmsg *msg) 1547 */ 1548 static int 1549 devfs_spec_ioctl(struct vop_ioctl_args *ap) 1550 { 1551 struct vnode *vp = ap->a_vp; 1552 struct devfs_node *node; 1553 cdev_t dev; 1554 1555 if ((dev = vp->v_rdev) == NULL) 1556 return (EBADF); /* device was revoked */ 1557 node = DEVFS_NODE(vp); 1558 1559 #if 0 1560 if (node) { 1561 nanotime(&node->atime); 1562 nanotime(&node->mtime); 1563 } 1564 #endif 1565 1566 return (dev_dioctl(dev, ap->a_command, ap->a_data, ap->a_fflag, 1567 ap->a_cred, ap->a_sysmsg)); 1568 } 1569 1570 /* 1571 * spec_poll(struct vnode *a_vp, int a_events, struct ucred *a_cred) 1572 */ 1573 /* ARGSUSED */ 1574 static int 1575 devfs_spec_poll(struct vop_poll_args *ap) 1576 { 1577 struct vnode *vp = ap->a_vp; 1578 struct devfs_node *node; 1579 cdev_t dev; 1580 1581 if ((dev = vp->v_rdev) == NULL) 1582 return (EBADF); /* device was revoked */ 1583 node = DEVFS_NODE(vp); 1584 1585 #if 0 1586 if (node) 1587 nanotime(&node->atime); 1588 #endif 1589 1590 return (dev_dpoll(dev, ap->a_events)); 1591 } 1592 1593 /* 1594 * spec_kqfilter(struct vnode *a_vp, struct knote *a_kn) 1595 */ 1596 /* ARGSUSED */ 1597 static int 1598 devfs_spec_kqfilter(struct vop_kqfilter_args *ap) 1599 { 1600 struct vnode *vp = ap->a_vp; 1601 struct devfs_node *node; 1602 cdev_t dev; 1603 1604 if ((dev = vp->v_rdev) == NULL) 1605 return (EBADF); /* device was revoked */ 1606 node = DEVFS_NODE(vp); 1607 1608 #if 0 1609 if (node) 1610 nanotime(&node->atime); 1611 #endif 1612 1613 return (dev_dkqfilter(dev, ap->a_kn)); 1614 } 1615 1616 /* 1617 * Convert a vnode strategy call into a device strategy call. Vnode strategy 1618 * calls are not limited to device DMA limits so we have to deal with the 1619 * case. 1620 * 1621 * spec_strategy(struct vnode *a_vp, struct bio *a_bio) 1622 */ 1623 static int 1624 devfs_spec_strategy(struct vop_strategy_args *ap) 1625 { 1626 struct bio *bio = ap->a_bio; 1627 struct buf *bp = bio->bio_buf; 1628 struct buf *nbp; 1629 struct vnode *vp; 1630 struct mount *mp; 1631 int chunksize; 1632 int maxiosize; 1633 1634 if (bp->b_cmd != BUF_CMD_READ && LIST_FIRST(&bp->b_dep) != NULL) 1635 buf_start(bp); 1636 1637 /* 1638 * Collect statistics on synchronous and asynchronous read 1639 * and write counts for disks that have associated filesystems. 1640 */ 1641 vp = ap->a_vp; 1642 KKASSERT(vp->v_rdev != NULL); /* XXX */ 1643 if (vn_isdisk(vp, NULL) && (mp = vp->v_rdev->si_mountpoint) != NULL) { 1644 if (bp->b_cmd == BUF_CMD_READ) { 1645 if (bp->b_flags & BIO_SYNC) 1646 mp->mnt_stat.f_syncreads++; 1647 else 1648 mp->mnt_stat.f_asyncreads++; 1649 } else { 1650 if (bp->b_flags & BIO_SYNC) 1651 mp->mnt_stat.f_syncwrites++; 1652 else 1653 mp->mnt_stat.f_asyncwrites++; 1654 } 1655 } 1656 1657 /* 1658 * Device iosize limitations only apply to read and write. Shortcut 1659 * the I/O if it fits. 1660 */ 1661 if ((maxiosize = vp->v_rdev->si_iosize_max) == 0) { 1662 devfs_debug(DEVFS_DEBUG_DEBUG, 1663 "%s: si_iosize_max not set!\n", 1664 dev_dname(vp->v_rdev)); 1665 maxiosize = MAXPHYS; 1666 } 1667 #if SPEC_CHAIN_DEBUG & 2 1668 maxiosize = 4096; 1669 #endif 1670 if (bp->b_bcount <= maxiosize || 1671 (bp->b_cmd != BUF_CMD_READ && bp->b_cmd != BUF_CMD_WRITE)) { 1672 dev_dstrategy_chain(vp->v_rdev, bio); 1673 return (0); 1674 } 1675 1676 /* 1677 * Clone the buffer and set up an I/O chain to chunk up the I/O. 1678 */ 1679 nbp = kmalloc(sizeof(*bp), M_DEVBUF, M_INTWAIT|M_ZERO); 1680 initbufbio(nbp); 1681 buf_dep_init(nbp); 1682 BUF_LOCKINIT(nbp); 1683 BUF_LOCK(nbp, LK_EXCLUSIVE); 1684 BUF_KERNPROC(nbp); 1685 nbp->b_vp = vp; 1686 nbp->b_flags = B_PAGING | (bp->b_flags & B_BNOCLIP); 1687 nbp->b_data = bp->b_data; 1688 nbp->b_bio1.bio_done = devfs_spec_strategy_done; 1689 nbp->b_bio1.bio_offset = bio->bio_offset; 1690 nbp->b_bio1.bio_caller_info1.ptr = bio; 1691 1692 /* 1693 * Start the first transfer 1694 */ 1695 if (vn_isdisk(vp, NULL)) 1696 chunksize = vp->v_rdev->si_bsize_phys; 1697 else 1698 chunksize = DEV_BSIZE; 1699 chunksize = maxiosize / chunksize * chunksize; 1700 #if SPEC_CHAIN_DEBUG & 1 1701 devfs_debug(DEVFS_DEBUG_DEBUG, 1702 "spec_strategy chained I/O chunksize=%d\n", 1703 chunksize); 1704 #endif 1705 nbp->b_cmd = bp->b_cmd; 1706 nbp->b_bcount = chunksize; 1707 nbp->b_bufsize = chunksize; /* used to detect a short I/O */ 1708 nbp->b_bio1.bio_caller_info2.index = chunksize; 1709 1710 #if SPEC_CHAIN_DEBUG & 1 1711 devfs_debug(DEVFS_DEBUG_DEBUG, 1712 "spec_strategy: chain %p offset %d/%d bcount %d\n", 1713 bp, 0, bp->b_bcount, nbp->b_bcount); 1714 #endif 1715 1716 dev_dstrategy(vp->v_rdev, &nbp->b_bio1); 1717 1718 if (DEVFS_NODE(vp)) { 1719 nanotime(&DEVFS_NODE(vp)->atime); 1720 nanotime(&DEVFS_NODE(vp)->mtime); 1721 } 1722 1723 return (0); 1724 } 1725 1726 /* 1727 * Chunked up transfer completion routine - chain transfers until done 1728 */ 1729 static 1730 void 1731 devfs_spec_strategy_done(struct bio *nbio) 1732 { 1733 struct buf *nbp = nbio->bio_buf; 1734 struct bio *bio = nbio->bio_caller_info1.ptr; /* original bio */ 1735 struct buf *bp = bio->bio_buf; /* original bp */ 1736 int chunksize = nbio->bio_caller_info2.index; /* chunking */ 1737 int boffset = nbp->b_data - bp->b_data; 1738 1739 if (nbp->b_flags & B_ERROR) { 1740 /* 1741 * An error terminates the chain, propogate the error back 1742 * to the original bp 1743 */ 1744 bp->b_flags |= B_ERROR; 1745 bp->b_error = nbp->b_error; 1746 bp->b_resid = bp->b_bcount - boffset + 1747 (nbp->b_bcount - nbp->b_resid); 1748 #if SPEC_CHAIN_DEBUG & 1 1749 devfs_debug(DEVFS_DEBUG_DEBUG, 1750 "spec_strategy: chain %p error %d bcount %d/%d\n", 1751 bp, bp->b_error, bp->b_bcount, 1752 bp->b_bcount - bp->b_resid); 1753 #endif 1754 kfree(nbp, M_DEVBUF); 1755 biodone(bio); 1756 } else if (nbp->b_resid) { 1757 /* 1758 * A short read or write terminates the chain 1759 */ 1760 bp->b_error = nbp->b_error; 1761 bp->b_resid = bp->b_bcount - boffset + 1762 (nbp->b_bcount - nbp->b_resid); 1763 #if SPEC_CHAIN_DEBUG & 1 1764 devfs_debug(DEVFS_DEBUG_DEBUG, 1765 "spec_strategy: chain %p short read(1) " 1766 "bcount %d/%d\n", 1767 bp, bp->b_bcount - bp->b_resid, bp->b_bcount); 1768 #endif 1769 kfree(nbp, M_DEVBUF); 1770 biodone(bio); 1771 } else if (nbp->b_bcount != nbp->b_bufsize) { 1772 /* 1773 * A short read or write can also occur by truncating b_bcount 1774 */ 1775 #if SPEC_CHAIN_DEBUG & 1 1776 devfs_debug(DEVFS_DEBUG_DEBUG, 1777 "spec_strategy: chain %p short read(2) " 1778 "bcount %d/%d\n", 1779 bp, nbp->b_bcount + boffset, bp->b_bcount); 1780 #endif 1781 bp->b_error = 0; 1782 bp->b_bcount = nbp->b_bcount + boffset; 1783 bp->b_resid = nbp->b_resid; 1784 kfree(nbp, M_DEVBUF); 1785 biodone(bio); 1786 } else if (nbp->b_bcount + boffset == bp->b_bcount) { 1787 /* 1788 * No more data terminates the chain 1789 */ 1790 #if SPEC_CHAIN_DEBUG & 1 1791 devfs_debug(DEVFS_DEBUG_DEBUG, 1792 "spec_strategy: chain %p finished bcount %d\n", 1793 bp, bp->b_bcount); 1794 #endif 1795 bp->b_error = 0; 1796 bp->b_resid = 0; 1797 kfree(nbp, M_DEVBUF); 1798 biodone(bio); 1799 } else { 1800 /* 1801 * Continue the chain 1802 */ 1803 boffset += nbp->b_bcount; 1804 nbp->b_data = bp->b_data + boffset; 1805 nbp->b_bcount = bp->b_bcount - boffset; 1806 if (nbp->b_bcount > chunksize) 1807 nbp->b_bcount = chunksize; 1808 nbp->b_bio1.bio_done = devfs_spec_strategy_done; 1809 nbp->b_bio1.bio_offset = bio->bio_offset + boffset; 1810 1811 #if SPEC_CHAIN_DEBUG & 1 1812 devfs_debug(DEVFS_DEBUG_DEBUG, 1813 "spec_strategy: chain %p offset %d/%d bcount %d\n", 1814 bp, boffset, bp->b_bcount, nbp->b_bcount); 1815 #endif 1816 1817 dev_dstrategy(nbp->b_vp->v_rdev, &nbp->b_bio1); 1818 } 1819 } 1820 1821 /* 1822 * spec_freeblks(struct vnode *a_vp, daddr_t a_addr, daddr_t a_length) 1823 */ 1824 static int 1825 devfs_spec_freeblks(struct vop_freeblks_args *ap) 1826 { 1827 struct buf *bp; 1828 1829 /* 1830 * XXX: This assumes that strategy does the deed right away. 1831 * XXX: this may not be TRTTD. 1832 */ 1833 KKASSERT(ap->a_vp->v_rdev != NULL); 1834 if ((dev_dflags(ap->a_vp->v_rdev) & D_CANFREE) == 0) 1835 return (0); 1836 bp = geteblk(ap->a_length); 1837 bp->b_cmd = BUF_CMD_FREEBLKS; 1838 bp->b_bio1.bio_offset = ap->a_offset; 1839 bp->b_bcount = ap->a_length; 1840 dev_dstrategy(ap->a_vp->v_rdev, &bp->b_bio1); 1841 return (0); 1842 } 1843 1844 /* 1845 * Implement degenerate case where the block requested is the block 1846 * returned, and assume that the entire device is contiguous in regards 1847 * to the contiguous block range (runp and runb). 1848 * 1849 * spec_bmap(struct vnode *a_vp, off_t a_loffset, 1850 * off_t *a_doffsetp, int *a_runp, int *a_runb) 1851 */ 1852 static int 1853 devfs_spec_bmap(struct vop_bmap_args *ap) 1854 { 1855 if (ap->a_doffsetp != NULL) 1856 *ap->a_doffsetp = ap->a_loffset; 1857 if (ap->a_runp != NULL) 1858 *ap->a_runp = MAXBSIZE; 1859 if (ap->a_runb != NULL) { 1860 if (ap->a_loffset < MAXBSIZE) 1861 *ap->a_runb = (int)ap->a_loffset; 1862 else 1863 *ap->a_runb = MAXBSIZE; 1864 } 1865 return (0); 1866 } 1867 1868 1869 /* 1870 * Special device advisory byte-level locks. 1871 * 1872 * spec_advlock(struct vnode *a_vp, caddr_t a_id, int a_op, 1873 * struct flock *a_fl, int a_flags) 1874 */ 1875 /* ARGSUSED */ 1876 static int 1877 devfs_spec_advlock(struct vop_advlock_args *ap) 1878 { 1879 return ((ap->a_flags & F_POSIX) ? EINVAL : EOPNOTSUPP); 1880 } 1881 1882 static void 1883 devfs_spec_getpages_iodone(struct bio *bio) 1884 { 1885 bio->bio_buf->b_cmd = BUF_CMD_DONE; 1886 wakeup(bio->bio_buf); 1887 } 1888 1889 /* 1890 * spec_getpages() - get pages associated with device vnode. 1891 * 1892 * Note that spec_read and spec_write do not use the buffer cache, so we 1893 * must fully implement getpages here. 1894 */ 1895 static int 1896 devfs_spec_getpages(struct vop_getpages_args *ap) 1897 { 1898 vm_offset_t kva; 1899 int error; 1900 int i, pcount, size; 1901 struct buf *bp; 1902 vm_page_t m; 1903 vm_ooffset_t offset; 1904 int toff, nextoff, nread; 1905 struct vnode *vp = ap->a_vp; 1906 int blksiz; 1907 int gotreqpage; 1908 1909 error = 0; 1910 pcount = round_page(ap->a_count) / PAGE_SIZE; 1911 1912 /* 1913 * Calculate the offset of the transfer and do sanity check. 1914 */ 1915 offset = IDX_TO_OFF(ap->a_m[0]->pindex) + ap->a_offset; 1916 1917 /* 1918 * Round up physical size for real devices. We cannot round using 1919 * v_mount's block size data because v_mount has nothing to do with 1920 * the device. i.e. it's usually '/dev'. We need the physical block 1921 * size for the device itself. 1922 * 1923 * We can't use v_rdev->si_mountpoint because it only exists when the 1924 * block device is mounted. However, we can use v_rdev. 1925 */ 1926 if (vn_isdisk(vp, NULL)) 1927 blksiz = vp->v_rdev->si_bsize_phys; 1928 else 1929 blksiz = DEV_BSIZE; 1930 1931 size = (ap->a_count + blksiz - 1) & ~(blksiz - 1); 1932 1933 bp = getpbuf(NULL); 1934 kva = (vm_offset_t)bp->b_data; 1935 1936 /* 1937 * Map the pages to be read into the kva. 1938 */ 1939 pmap_qenter(kva, ap->a_m, pcount); 1940 1941 /* Build a minimal buffer header. */ 1942 bp->b_cmd = BUF_CMD_READ; 1943 bp->b_bcount = size; 1944 bp->b_resid = 0; 1945 bp->b_runningbufspace = size; 1946 if (size) { 1947 runningbufspace += bp->b_runningbufspace; 1948 ++runningbufcount; 1949 } 1950 1951 bp->b_bio1.bio_offset = offset; 1952 bp->b_bio1.bio_done = devfs_spec_getpages_iodone; 1953 1954 mycpu->gd_cnt.v_vnodein++; 1955 mycpu->gd_cnt.v_vnodepgsin += pcount; 1956 1957 /* Do the input. */ 1958 vn_strategy(ap->a_vp, &bp->b_bio1); 1959 1960 crit_enter(); 1961 1962 /* We definitely need to be at splbio here. */ 1963 while (bp->b_cmd != BUF_CMD_DONE) 1964 tsleep(bp, 0, "spread", 0); 1965 1966 crit_exit(); 1967 1968 if (bp->b_flags & B_ERROR) { 1969 if (bp->b_error) 1970 error = bp->b_error; 1971 else 1972 error = EIO; 1973 } 1974 1975 /* 1976 * If EOF is encountered we must zero-extend the result in order 1977 * to ensure that the page does not contain garabge. When no 1978 * error occurs, an early EOF is indicated if b_bcount got truncated. 1979 * b_resid is relative to b_bcount and should be 0, but some devices 1980 * might indicate an EOF with b_resid instead of truncating b_bcount. 1981 */ 1982 nread = bp->b_bcount - bp->b_resid; 1983 if (nread < ap->a_count) 1984 bzero((caddr_t)kva + nread, ap->a_count - nread); 1985 pmap_qremove(kva, pcount); 1986 1987 gotreqpage = 0; 1988 for (i = 0, toff = 0; i < pcount; i++, toff = nextoff) { 1989 nextoff = toff + PAGE_SIZE; 1990 m = ap->a_m[i]; 1991 1992 m->flags &= ~PG_ZERO; 1993 1994 /* 1995 * NOTE: vm_page_undirty/clear_dirty etc do not clear the 1996 * pmap modified bit. pmap modified bit should have 1997 * already been cleared. 1998 */ 1999 if (nextoff <= nread) { 2000 m->valid = VM_PAGE_BITS_ALL; 2001 vm_page_undirty(m); 2002 } else if (toff < nread) { 2003 /* 2004 * Since this is a VM request, we have to supply the 2005 * unaligned offset to allow vm_page_set_valid() 2006 * to zero sub-DEV_BSIZE'd portions of the page. 2007 */ 2008 vm_page_set_valid(m, 0, nread - toff); 2009 vm_page_clear_dirty_end_nonincl(m, 0, nread - toff); 2010 } else { 2011 m->valid = 0; 2012 vm_page_undirty(m); 2013 } 2014 2015 if (i != ap->a_reqpage) { 2016 /* 2017 * Just in case someone was asking for this page we 2018 * now tell them that it is ok to use. 2019 */ 2020 if (!error || (m->valid == VM_PAGE_BITS_ALL)) { 2021 if (m->valid) { 2022 if (m->flags & PG_WANTED) { 2023 vm_page_activate(m); 2024 } else { 2025 vm_page_deactivate(m); 2026 } 2027 vm_page_wakeup(m); 2028 } else { 2029 vm_page_free(m); 2030 } 2031 } else { 2032 vm_page_free(m); 2033 } 2034 } else if (m->valid) { 2035 gotreqpage = 1; 2036 /* 2037 * Since this is a VM request, we need to make the 2038 * entire page presentable by zeroing invalid sections. 2039 */ 2040 if (m->valid != VM_PAGE_BITS_ALL) 2041 vm_page_zero_invalid(m, FALSE); 2042 } 2043 } 2044 if (!gotreqpage) { 2045 m = ap->a_m[ap->a_reqpage]; 2046 devfs_debug(DEVFS_DEBUG_WARNING, 2047 "spec_getpages:(%s) I/O read failure: (error=%d) bp %p vp %p\n", 2048 devtoname(vp->v_rdev), error, bp, bp->b_vp); 2049 devfs_debug(DEVFS_DEBUG_WARNING, 2050 " size: %d, resid: %d, a_count: %d, valid: 0x%x\n", 2051 size, bp->b_resid, ap->a_count, m->valid); 2052 devfs_debug(DEVFS_DEBUG_WARNING, 2053 " nread: %d, reqpage: %d, pindex: %lu, pcount: %d\n", 2054 nread, ap->a_reqpage, (u_long)m->pindex, pcount); 2055 /* 2056 * Free the buffer header back to the swap buffer pool. 2057 */ 2058 relpbuf(bp, NULL); 2059 return VM_PAGER_ERROR; 2060 } 2061 /* 2062 * Free the buffer header back to the swap buffer pool. 2063 */ 2064 relpbuf(bp, NULL); 2065 if (DEVFS_NODE(ap->a_vp)) 2066 nanotime(&DEVFS_NODE(ap->a_vp)->mtime); 2067 return VM_PAGER_OK; 2068 } 2069 2070 static __inline 2071 int 2072 sequential_heuristic(struct uio *uio, struct file *fp) 2073 { 2074 /* 2075 * Sequential heuristic - detect sequential operation 2076 */ 2077 if ((uio->uio_offset == 0 && fp->f_seqcount > 0) || 2078 uio->uio_offset == fp->f_nextoff) { 2079 /* 2080 * XXX we assume that the filesystem block size is 2081 * the default. Not true, but still gives us a pretty 2082 * good indicator of how sequential the read operations 2083 * are. 2084 */ 2085 int tmpseq = fp->f_seqcount; 2086 2087 tmpseq += (uio->uio_resid + BKVASIZE - 1) / BKVASIZE; 2088 if (tmpseq > IO_SEQMAX) 2089 tmpseq = IO_SEQMAX; 2090 fp->f_seqcount = tmpseq; 2091 return(fp->f_seqcount << IO_SEQSHIFT); 2092 } 2093 2094 /* 2095 * Not sequential, quick draw-down of seqcount 2096 */ 2097 if (fp->f_seqcount > 1) 2098 fp->f_seqcount = 1; 2099 else 2100 fp->f_seqcount = 0; 2101 return(0); 2102 } 2103 2104 extern SYSCTL_NODE(_vfs, OID_AUTO, devfs, CTLFLAG_RW, 0, "devfs"); 2105 2106 SYSCTL_INT(_vfs_devfs, OID_AUTO, mpsafe_writes, CTLFLAG_RD, &mpsafe_writes, 2107 0, "mpsafe writes"); 2108 SYSCTL_INT(_vfs_devfs, OID_AUTO, mplock_writes, CTLFLAG_RD, &mplock_writes, 2109 0, "non-mpsafe writes"); 2110 SYSCTL_INT(_vfs_devfs, OID_AUTO, mpsafe_reads, CTLFLAG_RD, &mpsafe_reads, 2111 0, "mpsafe reads"); 2112 SYSCTL_INT(_vfs_devfs, OID_AUTO, mplock_reads, CTLFLAG_RD, &mplock_reads, 2113 0, "non-mpsafe reads"); 2114