1 /* $NetBSD: vfs_vnops.c,v 1.107 2006/03/10 11:07:01 yamt Exp $ */ 2 3 /* 4 * Copyright (c) 1982, 1986, 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 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. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)vfs_vnops.c 8.14 (Berkeley) 6/15/95 37 */ 38 39 #include <sys/cdefs.h> 40 __KERNEL_RCSID(0, "$NetBSD: vfs_vnops.c,v 1.107 2006/03/10 11:07:01 yamt Exp $"); 41 42 #include "opt_verified_exec.h" 43 44 #include "fs_union.h" 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 #include <sys/kernel.h> 49 #include <sys/file.h> 50 #include <sys/stat.h> 51 #include <sys/buf.h> 52 #include <sys/proc.h> 53 #include <sys/malloc.h> 54 #include <sys/mount.h> 55 #include <sys/namei.h> 56 #include <sys/vnode.h> 57 #include <sys/ioctl.h> 58 #include <sys/tty.h> 59 #include <sys/poll.h> 60 61 #include <miscfs/specfs/specdev.h> 62 63 #include <uvm/uvm_extern.h> 64 #include <uvm/uvm_readahead.h> 65 66 #ifdef UNION 67 #include <fs/union/union.h> 68 #endif 69 70 #if defined(LKM) || defined(UNION) 71 int (*vn_union_readdir_hook) (struct vnode **, struct file *, struct lwp *); 72 #endif 73 74 #ifdef VERIFIED_EXEC 75 #include <sys/verified_exec.h> 76 #endif 77 78 static int vn_read(struct file *fp, off_t *offset, struct uio *uio, 79 struct ucred *cred, int flags); 80 static int vn_write(struct file *fp, off_t *offset, struct uio *uio, 81 struct ucred *cred, int flags); 82 static int vn_closefile(struct file *fp, struct lwp *l); 83 static int vn_poll(struct file *fp, int events, struct lwp *l); 84 static int vn_fcntl(struct file *fp, u_int com, void *data, struct lwp *l); 85 static int vn_statfile(struct file *fp, struct stat *sb, struct lwp *l); 86 static int vn_ioctl(struct file *fp, u_long com, void *data, struct lwp *l); 87 88 const struct fileops vnops = { 89 vn_read, vn_write, vn_ioctl, vn_fcntl, vn_poll, 90 vn_statfile, vn_closefile, vn_kqfilter 91 }; 92 93 /* 94 * Common code for vnode open operations. 95 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine. 96 */ 97 int 98 vn_open(struct nameidata *ndp, int fmode, int cmode) 99 { 100 struct vnode *vp; 101 struct mount *mp; 102 struct lwp *l = ndp->ni_cnd.cn_lwp; 103 struct ucred *cred = l->l_proc->p_ucred; 104 struct vattr va; 105 int error; 106 #ifdef VERIFIED_EXEC 107 struct veriexec_hash_entry *vhe = NULL; 108 char pathbuf[MAXPATHLEN]; 109 size_t pathlen; 110 int (*copyfun)(const void *, void *, size_t, size_t *) = 111 ndp->ni_segflg == UIO_SYSSPACE ? copystr : copyinstr; 112 #endif /* VERIFIED_EXEC */ 113 114 #ifdef VERIFIED_EXEC 115 error = (*copyfun)(ndp->ni_dirp, pathbuf, sizeof(pathbuf), &pathlen); 116 if (error) { 117 if (veriexec_verbose >= 1) 118 printf("veriexec: Can't copy path. (error=%d)\n", 119 error); 120 121 return (error); 122 } 123 #endif /* VERIFIED_EXEC */ 124 125 restart: 126 if (fmode & O_CREAT) { 127 ndp->ni_cnd.cn_nameiop = CREATE; 128 ndp->ni_cnd.cn_flags = LOCKPARENT | LOCKLEAF; 129 if ((fmode & O_EXCL) == 0 && 130 ((fmode & O_NOFOLLOW) == 0)) 131 ndp->ni_cnd.cn_flags |= FOLLOW; 132 if ((error = namei(ndp)) != 0) 133 return (error); 134 if (ndp->ni_vp == NULL) { 135 #ifdef VERIFIED_EXEC 136 /* Lockdown mode: Prevent creation of new files. */ 137 if (veriexec_strict >= 3) { 138 VOP_ABORTOP(ndp->ni_dvp, &ndp->ni_cnd); 139 140 printf("Veriexec: vn_open: Preventing " 141 "new file creation in %s.\n", 142 pathbuf); 143 144 vp = ndp->ni_dvp; 145 error = EPERM; 146 goto bad; 147 } 148 #endif /* VERIFIED_EXEC */ 149 150 VATTR_NULL(&va); 151 va.va_type = VREG; 152 va.va_mode = cmode; 153 if (fmode & O_EXCL) 154 va.va_vaflags |= VA_EXCLUSIVE; 155 if (vn_start_write(ndp->ni_dvp, &mp, V_NOWAIT) != 0) { 156 VOP_ABORTOP(ndp->ni_dvp, &ndp->ni_cnd); 157 vput(ndp->ni_dvp); 158 if ((error = vn_start_write(NULL, &mp, 159 V_WAIT | V_SLEEPONLY | V_PCATCH)) != 0) 160 return (error); 161 goto restart; 162 } 163 VOP_LEASE(ndp->ni_dvp, l, cred, LEASE_WRITE); 164 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp, 165 &ndp->ni_cnd, &va); 166 vn_finished_write(mp, 0); 167 if (error) 168 return (error); 169 fmode &= ~O_TRUNC; 170 vp = ndp->ni_vp; 171 } else { 172 VOP_ABORTOP(ndp->ni_dvp, &ndp->ni_cnd); 173 if (ndp->ni_dvp == ndp->ni_vp) 174 vrele(ndp->ni_dvp); 175 else 176 vput(ndp->ni_dvp); 177 ndp->ni_dvp = NULL; 178 vp = ndp->ni_vp; 179 if (fmode & O_EXCL) { 180 error = EEXIST; 181 goto bad; 182 } 183 fmode &= ~O_CREAT; 184 } 185 } else { 186 ndp->ni_cnd.cn_nameiop = LOOKUP; 187 ndp->ni_cnd.cn_flags = LOCKLEAF; 188 if ((fmode & O_NOFOLLOW) == 0) 189 ndp->ni_cnd.cn_flags |= FOLLOW; 190 if ((error = namei(ndp)) != 0) 191 return (error); 192 vp = ndp->ni_vp; 193 } 194 if (vp->v_type == VSOCK) { 195 error = EOPNOTSUPP; 196 goto bad; 197 } 198 if (ndp->ni_vp->v_type == VLNK) { 199 error = EFTYPE; 200 goto bad; 201 } 202 203 #ifdef VERIFIED_EXEC 204 if ((error = VOP_GETATTR(vp, &va, cred, l)) != 0) 205 goto bad; 206 #endif 207 208 if ((fmode & O_CREAT) == 0) { 209 #ifdef VERIFIED_EXEC 210 if ((error = veriexec_verify(l, vp, &va, pathbuf, 211 VERIEXEC_FILE, &vhe)) != 0) 212 goto bad; 213 #endif 214 215 if (fmode & FREAD) { 216 if ((error = VOP_ACCESS(vp, VREAD, cred, l)) != 0) 217 goto bad; 218 } 219 220 if (fmode & (FWRITE | O_TRUNC)) { 221 if (vp->v_type == VDIR) { 222 error = EISDIR; 223 goto bad; 224 } 225 if ((error = vn_writechk(vp)) != 0 || 226 (error = VOP_ACCESS(vp, VWRITE, cred, l)) != 0) 227 goto bad; 228 #ifdef VERIFIED_EXEC 229 if (vhe != NULL) { 230 veriexec_report("Write access request.", 231 pathbuf, &va, l, 232 REPORT_NOVERBOSE, 233 REPORT_ALARM, 234 REPORT_NOPANIC); 235 236 /* IPS mode: Deny writing to monitored files. */ 237 if (veriexec_strict >= 2) { 238 error = EPERM; 239 goto bad; 240 } else { 241 vhe->status = FINGERPRINT_NOTEVAL; 242 } 243 } 244 #endif 245 } 246 } 247 248 if (fmode & O_TRUNC) { 249 VOP_UNLOCK(vp, 0); /* XXX */ 250 if ((error = vn_start_write(vp, &mp, V_WAIT | V_PCATCH)) != 0) { 251 vrele(vp); 252 return (error); 253 } 254 VOP_LEASE(vp, l, cred, LEASE_WRITE); 255 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); /* XXX */ 256 VATTR_NULL(&va); 257 va.va_size = 0; 258 error = VOP_SETATTR(vp, &va, cred, l); 259 vn_finished_write(mp, 0); 260 if (error != 0) 261 goto bad; 262 } 263 if ((error = VOP_OPEN(vp, fmode, cred, l)) != 0) 264 goto bad; 265 if (vp->v_type == VREG && 266 uvn_attach(vp, fmode & FWRITE ? VM_PROT_WRITE : 0) == NULL) { 267 error = EIO; 268 goto bad; 269 } 270 if (fmode & FWRITE) 271 vp->v_writecount++; 272 273 return (0); 274 bad: 275 vput(vp); 276 return (error); 277 } 278 279 /* 280 * Check for write permissions on the specified vnode. 281 * Prototype text segments cannot be written. 282 */ 283 int 284 vn_writechk(struct vnode *vp) 285 { 286 287 /* 288 * If the vnode is in use as a process's text, 289 * we can't allow writing. 290 */ 291 if (vp->v_flag & VTEXT) 292 return (ETXTBSY); 293 return (0); 294 } 295 296 /* 297 * Mark a vnode as having executable mappings. 298 */ 299 void 300 vn_markexec(struct vnode *vp) 301 { 302 if ((vp->v_flag & VEXECMAP) == 0) { 303 uvmexp.filepages -= vp->v_uobj.uo_npages; 304 uvmexp.execpages += vp->v_uobj.uo_npages; 305 } 306 vp->v_flag |= VEXECMAP; 307 } 308 309 /* 310 * Mark a vnode as being the text of a process. 311 * Fail if the vnode is currently writable. 312 */ 313 int 314 vn_marktext(struct vnode *vp) 315 { 316 317 if (vp->v_writecount != 0) { 318 KASSERT((vp->v_flag & VTEXT) == 0); 319 return (ETXTBSY); 320 } 321 vp->v_flag |= VTEXT; 322 vn_markexec(vp); 323 return (0); 324 } 325 326 /* 327 * Vnode close call 328 * 329 * Note: takes an unlocked vnode, while VOP_CLOSE takes a locked node. 330 */ 331 int 332 vn_close(struct vnode *vp, int flags, struct ucred *cred, struct lwp *l) 333 { 334 int error; 335 336 if (flags & FWRITE) 337 vp->v_writecount--; 338 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 339 error = VOP_CLOSE(vp, flags, cred, l); 340 vput(vp); 341 return (error); 342 } 343 344 /* 345 * Package up an I/O request on a vnode into a uio and do it. 346 */ 347 int 348 vn_rdwr(enum uio_rw rw, struct vnode *vp, caddr_t base, int len, off_t offset, 349 enum uio_seg segflg, int ioflg, struct ucred *cred, size_t *aresid, 350 struct lwp *l) 351 { 352 struct uio auio; 353 struct iovec aiov; 354 struct mount *mp; 355 int error; 356 357 if ((ioflg & IO_NODELOCKED) == 0) { 358 if (rw == UIO_READ) { 359 vn_lock(vp, LK_SHARED | LK_RETRY); 360 } else /* UIO_WRITE */ { 361 if (vp->v_type != VCHR && 362 (error = vn_start_write(vp, &mp, V_WAIT | V_PCATCH)) 363 != 0) 364 return (error); 365 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 366 } 367 } 368 auio.uio_iov = &aiov; 369 auio.uio_iovcnt = 1; 370 aiov.iov_base = base; 371 aiov.iov_len = len; 372 auio.uio_resid = len; 373 auio.uio_offset = offset; 374 auio.uio_rw = rw; 375 if (segflg == UIO_SYSSPACE) { 376 UIO_SETUP_SYSSPACE(&auio); 377 } else { 378 auio.uio_vmspace = l->l_proc->p_vmspace; 379 } 380 if (rw == UIO_READ) { 381 error = VOP_READ(vp, &auio, ioflg, cred); 382 } else { 383 error = VOP_WRITE(vp, &auio, ioflg, cred); 384 } 385 if (aresid) 386 *aresid = auio.uio_resid; 387 else 388 if (auio.uio_resid && error == 0) 389 error = EIO; 390 if ((ioflg & IO_NODELOCKED) == 0) { 391 if (rw == UIO_WRITE) 392 vn_finished_write(mp, 0); 393 VOP_UNLOCK(vp, 0); 394 } 395 return (error); 396 } 397 398 int 399 vn_readdir(struct file *fp, char *bf, int segflg, u_int count, int *done, 400 struct lwp *l, off_t **cookies, int *ncookies) 401 { 402 struct vnode *vp = (struct vnode *)fp->f_data; 403 struct iovec aiov; 404 struct uio auio; 405 int error, eofflag; 406 407 unionread: 408 if (vp->v_type != VDIR) 409 return (EINVAL); 410 aiov.iov_base = bf; 411 aiov.iov_len = count; 412 auio.uio_iov = &aiov; 413 auio.uio_iovcnt = 1; 414 auio.uio_rw = UIO_READ; 415 if (segflg == UIO_SYSSPACE) { 416 UIO_SETUP_SYSSPACE(&auio); 417 } else { 418 KASSERT(l == curlwp); 419 auio.uio_vmspace = l->l_proc->p_vmspace; 420 } 421 auio.uio_resid = count; 422 vn_lock(vp, LK_SHARED | LK_RETRY); 423 auio.uio_offset = fp->f_offset; 424 error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, cookies, 425 ncookies); 426 fp->f_offset = auio.uio_offset; 427 VOP_UNLOCK(vp, 0); 428 if (error) 429 return (error); 430 431 #if defined(UNION) || defined(LKM) 432 if (count == auio.uio_resid && vn_union_readdir_hook) { 433 struct vnode *ovp = vp; 434 435 error = (*vn_union_readdir_hook)(&vp, fp, l); 436 if (error) 437 return (error); 438 if (vp != ovp) 439 goto unionread; 440 } 441 #endif /* UNION || LKM */ 442 443 if (count == auio.uio_resid && (vp->v_flag & VROOT) && 444 (vp->v_mount->mnt_flag & MNT_UNION)) { 445 struct vnode *tvp = vp; 446 vp = vp->v_mount->mnt_vnodecovered; 447 VREF(vp); 448 fp->f_data = vp; 449 fp->f_offset = 0; 450 vrele(tvp); 451 goto unionread; 452 } 453 *done = count - auio.uio_resid; 454 return error; 455 } 456 457 /* 458 * File table vnode read routine. 459 */ 460 static int 461 vn_read(struct file *fp, off_t *offset, struct uio *uio, struct ucred *cred, 462 int flags) 463 { 464 struct vnode *vp = (struct vnode *)fp->f_data; 465 int count, error, ioflag; 466 struct lwp *l = curlwp; 467 468 VOP_LEASE(vp, l, cred, LEASE_READ); 469 ioflag = IO_ADV_ENCODE(fp->f_advice); 470 if (fp->f_flag & FNONBLOCK) 471 ioflag |= IO_NDELAY; 472 if ((fp->f_flag & (FFSYNC | FRSYNC)) == (FFSYNC | FRSYNC)) 473 ioflag |= IO_SYNC; 474 if (fp->f_flag & FALTIO) 475 ioflag |= IO_ALTSEMANTICS; 476 vn_lock(vp, LK_SHARED | LK_RETRY); 477 uio->uio_offset = *offset; 478 count = uio->uio_resid; 479 error = VOP_READ(vp, uio, ioflag, cred); 480 if (flags & FOF_UPDATE_OFFSET) 481 *offset += count - uio->uio_resid; 482 VOP_UNLOCK(vp, 0); 483 return (error); 484 } 485 486 /* 487 * File table vnode write routine. 488 */ 489 static int 490 vn_write(struct file *fp, off_t *offset, struct uio *uio, struct ucred *cred, 491 int flags) 492 { 493 struct vnode *vp = (struct vnode *)fp->f_data; 494 struct mount *mp; 495 int count, error, ioflag = IO_UNIT; 496 struct lwp *l = curlwp; 497 498 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 499 ioflag |= IO_APPEND; 500 if (fp->f_flag & FNONBLOCK) 501 ioflag |= IO_NDELAY; 502 if (fp->f_flag & FFSYNC || 503 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS))) 504 ioflag |= IO_SYNC; 505 else if (fp->f_flag & FDSYNC) 506 ioflag |= IO_DSYNC; 507 if (fp->f_flag & FALTIO) 508 ioflag |= IO_ALTSEMANTICS; 509 mp = NULL; 510 if (vp->v_type != VCHR && 511 (error = vn_start_write(vp, &mp, V_WAIT | V_PCATCH)) != 0) 512 return (error); 513 VOP_LEASE(vp, l, cred, LEASE_WRITE); 514 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 515 uio->uio_offset = *offset; 516 count = uio->uio_resid; 517 error = VOP_WRITE(vp, uio, ioflag, cred); 518 if (flags & FOF_UPDATE_OFFSET) { 519 if (ioflag & IO_APPEND) 520 *offset = uio->uio_offset; 521 else 522 *offset += count - uio->uio_resid; 523 } 524 VOP_UNLOCK(vp, 0); 525 vn_finished_write(mp, 0); 526 return (error); 527 } 528 529 /* 530 * File table vnode stat routine. 531 */ 532 static int 533 vn_statfile(struct file *fp, struct stat *sb, struct lwp *l) 534 { 535 struct vnode *vp = (struct vnode *)fp->f_data; 536 537 return vn_stat(vp, sb, l); 538 } 539 540 int 541 vn_stat(struct vnode *vp, struct stat *sb, struct lwp *l) 542 { 543 struct vattr va; 544 int error; 545 mode_t mode; 546 547 error = VOP_GETATTR(vp, &va, l->l_proc->p_ucred, l); 548 if (error) 549 return (error); 550 /* 551 * Copy from vattr table 552 */ 553 sb->st_dev = va.va_fsid; 554 sb->st_ino = va.va_fileid; 555 mode = va.va_mode; 556 switch (vp->v_type) { 557 case VREG: 558 mode |= S_IFREG; 559 break; 560 case VDIR: 561 mode |= S_IFDIR; 562 break; 563 case VBLK: 564 mode |= S_IFBLK; 565 break; 566 case VCHR: 567 mode |= S_IFCHR; 568 break; 569 case VLNK: 570 mode |= S_IFLNK; 571 break; 572 case VSOCK: 573 mode |= S_IFSOCK; 574 break; 575 case VFIFO: 576 mode |= S_IFIFO; 577 break; 578 default: 579 return (EBADF); 580 }; 581 sb->st_mode = mode; 582 sb->st_nlink = va.va_nlink; 583 sb->st_uid = va.va_uid; 584 sb->st_gid = va.va_gid; 585 sb->st_rdev = va.va_rdev; 586 sb->st_size = va.va_size; 587 sb->st_atimespec = va.va_atime; 588 sb->st_mtimespec = va.va_mtime; 589 sb->st_ctimespec = va.va_ctime; 590 sb->st_birthtimespec = va.va_birthtime; 591 sb->st_blksize = va.va_blocksize; 592 sb->st_flags = va.va_flags; 593 sb->st_gen = 0; 594 sb->st_blocks = va.va_bytes / S_BLKSIZE; 595 return (0); 596 } 597 598 /* 599 * File table vnode fcntl routine. 600 */ 601 static int 602 vn_fcntl(struct file *fp, u_int com, void *data, struct lwp *l) 603 { 604 struct vnode *vp = ((struct vnode *)fp->f_data); 605 int error; 606 607 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 608 error = VOP_FCNTL(vp, com, data, fp->f_flag, l->l_proc->p_ucred, l); 609 VOP_UNLOCK(vp, 0); 610 return (error); 611 } 612 613 /* 614 * File table vnode ioctl routine. 615 */ 616 static int 617 vn_ioctl(struct file *fp, u_long com, void *data, struct lwp *l) 618 { 619 struct vnode *vp = ((struct vnode *)fp->f_data); 620 struct proc *p = l->l_proc; 621 struct vattr vattr; 622 int error; 623 624 switch (vp->v_type) { 625 626 case VREG: 627 case VDIR: 628 if (com == FIONREAD) { 629 error = VOP_GETATTR(vp, &vattr, l->l_proc->p_ucred, l); 630 if (error) 631 return (error); 632 *(int *)data = vattr.va_size - fp->f_offset; 633 return (0); 634 } 635 if ((com == FIONWRITE) || (com == FIONSPACE)) { 636 /* 637 * Files don't have send queues, so there never 638 * are any bytes in them, nor is there any 639 * open space in them. 640 */ 641 *(int *)data = 0; 642 return (0); 643 } 644 if (com == FIOGETBMAP) { 645 daddr_t *block; 646 647 if (*(daddr_t *)data < 0) 648 return (EINVAL); 649 block = (daddr_t *)data; 650 return (VOP_BMAP(vp, *block, NULL, block, NULL)); 651 } 652 if (com == OFIOGETBMAP) { 653 daddr_t ibn, obn; 654 655 if (*(int32_t *)data < 0) 656 return (EINVAL); 657 ibn = (daddr_t)*(int32_t *)data; 658 error = VOP_BMAP(vp, ibn, NULL, &obn, NULL); 659 *(int32_t *)data = (int32_t)obn; 660 return error; 661 } 662 if (com == FIONBIO || com == FIOASYNC) /* XXX */ 663 return (0); /* XXX */ 664 /* fall into ... */ 665 case VFIFO: 666 case VCHR: 667 case VBLK: 668 error = VOP_IOCTL(vp, com, data, fp->f_flag, 669 l->l_proc->p_ucred, l); 670 if (error == 0 && com == TIOCSCTTY) { 671 if (p->p_session->s_ttyvp) 672 vrele(p->p_session->s_ttyvp); 673 p->p_session->s_ttyvp = vp; 674 VREF(vp); 675 } 676 return (error); 677 678 default: 679 return (EPASSTHROUGH); 680 } 681 } 682 683 /* 684 * File table vnode poll routine. 685 */ 686 static int 687 vn_poll(struct file *fp, int events, struct lwp *l) 688 { 689 690 return (VOP_POLL(((struct vnode *)fp->f_data), events, l)); 691 } 692 693 /* 694 * File table vnode kqfilter routine. 695 */ 696 int 697 vn_kqfilter(struct file *fp, struct knote *kn) 698 { 699 700 return (VOP_KQFILTER((struct vnode *)fp->f_data, kn)); 701 } 702 703 /* 704 * Check that the vnode is still valid, and if so 705 * acquire requested lock. 706 */ 707 int 708 vn_lock(struct vnode *vp, int flags) 709 { 710 int error; 711 712 #if 0 713 KASSERT(vp->v_usecount > 0 || (flags & LK_INTERLOCK) != 0 714 || (vp->v_flag & VONWORKLST) != 0); 715 #endif 716 KASSERT((flags & 717 ~(LK_INTERLOCK|LK_SHARED|LK_EXCLUSIVE|LK_DRAIN|LK_NOWAIT|LK_RETRY| 718 LK_SETRECURSE|LK_CANRECURSE)) 719 == 0); 720 721 do { 722 if ((flags & LK_INTERLOCK) == 0) 723 simple_lock(&vp->v_interlock); 724 if (vp->v_flag & VXLOCK) { 725 if (flags & LK_NOWAIT) { 726 simple_unlock(&vp->v_interlock); 727 return EBUSY; 728 } 729 vp->v_flag |= VXWANT; 730 ltsleep(vp, PINOD | PNORELOCK, 731 "vn_lock", 0, &vp->v_interlock); 732 error = ENOENT; 733 } else { 734 error = VOP_LOCK(vp, 735 (flags & ~LK_RETRY) | LK_INTERLOCK); 736 if (error == 0 || error == EDEADLK || error == EBUSY) 737 return (error); 738 } 739 flags &= ~LK_INTERLOCK; 740 } while (flags & LK_RETRY); 741 return (error); 742 } 743 744 /* 745 * File table vnode close routine. 746 */ 747 static int 748 vn_closefile(struct file *fp, struct lwp *l) 749 { 750 751 return (vn_close(((struct vnode *)fp->f_data), fp->f_flag, 752 fp->f_cred, l)); 753 } 754 755 /* 756 * Enable LK_CANRECURSE on lock. Return prior status. 757 */ 758 u_int 759 vn_setrecurse(struct vnode *vp) 760 { 761 struct lock *lkp = &vp->v_lock; 762 u_int retval = lkp->lk_flags & LK_CANRECURSE; 763 764 lkp->lk_flags |= LK_CANRECURSE; 765 return retval; 766 } 767 768 /* 769 * Called when done with locksetrecurse. 770 */ 771 void 772 vn_restorerecurse(struct vnode *vp, u_int flags) 773 { 774 struct lock *lkp = &vp->v_lock; 775 776 lkp->lk_flags &= ~LK_CANRECURSE; 777 lkp->lk_flags |= flags; 778 } 779 780 int 781 vn_cow_establish(struct vnode *vp, 782 int (*func)(void *, struct buf *), void *cookie) 783 { 784 int s; 785 struct spec_cow_entry *e; 786 787 MALLOC(e, struct spec_cow_entry *, sizeof(struct spec_cow_entry), 788 M_DEVBUF, M_WAITOK); 789 e->ce_func = func; 790 e->ce_cookie = cookie; 791 792 SPEC_COW_LOCK(vp->v_specinfo, s); 793 vp->v_spec_cow_req++; 794 while (vp->v_spec_cow_count > 0) 795 ltsleep(&vp->v_spec_cow_req, PRIBIO, "cowlist", 0, 796 &vp->v_spec_cow_slock); 797 798 SLIST_INSERT_HEAD(&vp->v_spec_cow_head, e, ce_list); 799 800 vp->v_spec_cow_req--; 801 if (vp->v_spec_cow_req == 0) 802 wakeup(&vp->v_spec_cow_req); 803 SPEC_COW_UNLOCK(vp->v_specinfo, s); 804 805 return 0; 806 } 807 808 int 809 vn_cow_disestablish(struct vnode *vp, 810 int (*func)(void *, struct buf *), void *cookie) 811 { 812 int s; 813 struct spec_cow_entry *e; 814 815 SPEC_COW_LOCK(vp->v_specinfo, s); 816 vp->v_spec_cow_req++; 817 while (vp->v_spec_cow_count > 0) 818 ltsleep(&vp->v_spec_cow_req, PRIBIO, "cowlist", 0, 819 &vp->v_spec_cow_slock); 820 821 SLIST_FOREACH(e, &vp->v_spec_cow_head, ce_list) 822 if (e->ce_func == func && e->ce_cookie == cookie) { 823 SLIST_REMOVE(&vp->v_spec_cow_head, e, 824 spec_cow_entry, ce_list); 825 FREE(e, M_DEVBUF); 826 break; 827 } 828 829 vp->v_spec_cow_req--; 830 if (vp->v_spec_cow_req == 0) 831 wakeup(&vp->v_spec_cow_req); 832 SPEC_COW_UNLOCK(vp->v_specinfo, s); 833 834 return e ? 0 : EINVAL; 835 } 836 837 /* 838 * Simplified in-kernel wrapper calls for extended attribute access. 839 * Both calls pass in a NULL credential, authorizing a "kernel" access. 840 * Set IO_NODELOCKED in ioflg if the vnode is already locked. 841 */ 842 int 843 vn_extattr_get(struct vnode *vp, int ioflg, int attrnamespace, 844 const char *attrname, size_t *buflen, void *bf, struct lwp *l) 845 { 846 struct uio auio; 847 struct iovec aiov; 848 int error; 849 850 aiov.iov_len = *buflen; 851 aiov.iov_base = bf; 852 853 auio.uio_iov = &aiov; 854 auio.uio_iovcnt = 1; 855 auio.uio_rw = UIO_READ; 856 auio.uio_offset = 0; 857 auio.uio_resid = *buflen; 858 UIO_SETUP_SYSSPACE(&auio); 859 860 if ((ioflg & IO_NODELOCKED) == 0) 861 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 862 863 error = VOP_GETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, NULL, 864 l); 865 866 if ((ioflg & IO_NODELOCKED) == 0) 867 VOP_UNLOCK(vp, 0); 868 869 if (error == 0) 870 *buflen = *buflen - auio.uio_resid; 871 872 return (error); 873 } 874 875 /* 876 * XXX Failure mode if partially written? 877 */ 878 int 879 vn_extattr_set(struct vnode *vp, int ioflg, int attrnamespace, 880 const char *attrname, size_t buflen, const void *bf, struct lwp *l) 881 { 882 struct uio auio; 883 struct iovec aiov; 884 struct mount *mp; 885 int error; 886 887 aiov.iov_len = buflen; 888 aiov.iov_base = __UNCONST(bf); /* XXXUNCONST kills const */ 889 890 auio.uio_iov = &aiov; 891 auio.uio_iovcnt = 1; 892 auio.uio_rw = UIO_WRITE; 893 auio.uio_offset = 0; 894 auio.uio_resid = buflen; 895 UIO_SETUP_SYSSPACE(&auio); 896 897 if ((ioflg & IO_NODELOCKED) == 0) { 898 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) 899 return (error); 900 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 901 } 902 903 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, l); 904 905 if ((ioflg & IO_NODELOCKED) == 0) { 906 vn_finished_write(mp, 0); 907 VOP_UNLOCK(vp, 0); 908 } 909 910 return (error); 911 } 912 913 int 914 vn_extattr_rm(struct vnode *vp, int ioflg, int attrnamespace, 915 const char *attrname, struct lwp *l) 916 { 917 struct mount *mp; 918 int error; 919 920 if ((ioflg & IO_NODELOCKED) == 0) { 921 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) 922 return (error); 923 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 924 } 925 926 error = VOP_DELETEEXTATTR(vp, attrnamespace, attrname, NULL, l); 927 if (error == EOPNOTSUPP) 928 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, NULL, 929 NULL, l); 930 931 if ((ioflg & IO_NODELOCKED) == 0) { 932 vn_finished_write(mp, 0); 933 VOP_UNLOCK(vp, 0); 934 } 935 936 return (error); 937 } 938 939 /* 940 * Preparing to start a filesystem write operation. If the operation is 941 * permitted, then we bump the count of operations in progress and 942 * proceed. If a suspend request is in progress, we wait until the 943 * suspension is over, and then proceed. 944 * V_PCATCH adds PCATCH to the tsleep flags. 945 * V_WAIT waits until suspension is over. Otherwise returns EWOULDBLOCK. 946 * V_SLEEPONLY wait, but do not bump the operations count. 947 * V_LOWER this is a lower level operation. No further vnodes should be 948 * locked. Otherwise it is a upper level operation. No vnodes 949 * should be locked. 950 */ 951 int 952 vn_start_write(struct vnode *vp, struct mount **mpp, int flags) 953 { 954 struct mount *mp; 955 int error, mask, prio; 956 957 /* 958 * If a vnode is provided, get and return the mount point that 959 * to which it will write. 960 */ 961 if (vp != NULL) { 962 *mpp = vp->v_mount; 963 } 964 if ((mp = *mpp) == NULL) 965 return (0); 966 mp = mp->mnt_leaf; 967 /* 968 * Check on status of suspension. 969 */ 970 prio = PUSER - 1; 971 if (flags & V_PCATCH) 972 prio |= PCATCH; 973 974 if ((flags & V_LOWER) == 0) 975 mask = IMNT_SUSPEND; 976 else 977 mask = IMNT_SUSPENDLOW; 978 979 while ((mp->mnt_iflag & mask) != 0) { 980 if ((flags & V_WAIT) == 0) 981 return (EWOULDBLOCK); 982 error = tsleep(&mp->mnt_flag, prio, "suspfs", 0); 983 if (error) 984 return (error); 985 } 986 if (flags & V_SLEEPONLY) 987 return (0); 988 simple_lock(&mp->mnt_slock); 989 if ((flags & V_LOWER) == 0) 990 mp->mnt_writeopcountupper++; 991 else 992 mp->mnt_writeopcountlower++; 993 simple_unlock(&mp->mnt_slock); 994 return (0); 995 } 996 997 /* 998 * Filesystem write operation has completed. If we are suspending and this 999 * operation is the last one, notify the suspender that the suspension is 1000 * now in effect. 1001 */ 1002 void 1003 vn_finished_write(struct mount *mp, int flags) 1004 { 1005 if (mp == NULL) 1006 return; 1007 mp = mp->mnt_leaf; 1008 simple_lock(&mp->mnt_slock); 1009 if ((flags & V_LOWER) == 0) { 1010 mp->mnt_writeopcountupper--; 1011 if (mp->mnt_writeopcountupper < 0) 1012 printf("vn_finished_write: neg cnt upper=%d\n", 1013 mp->mnt_writeopcountupper); 1014 if ((mp->mnt_iflag & IMNT_SUSPEND) != 0 && 1015 mp->mnt_writeopcountupper <= 0) 1016 wakeup(&mp->mnt_writeopcountupper); 1017 } else { 1018 mp->mnt_writeopcountlower--; 1019 if (mp->mnt_writeopcountlower < 0) 1020 printf("vn_finished_write: neg cnt lower=%d\n", 1021 mp->mnt_writeopcountlower); 1022 if ((mp->mnt_iflag & IMNT_SUSPENDLOW) != 0 && 1023 mp->mnt_writeopcountupper <= 0) 1024 wakeup(&mp->mnt_writeopcountlower); 1025 } 1026 simple_unlock(&mp->mnt_slock); 1027 } 1028 1029 void 1030 vn_ra_allocctx(struct vnode *vp) 1031 { 1032 struct uvm_ractx *ra = NULL; 1033 1034 if (vp->v_type != VREG) { 1035 return; 1036 } 1037 if (vp->v_ractx != NULL) { 1038 return; 1039 } 1040 simple_lock(&vp->v_interlock); 1041 if (vp->v_ractx == NULL) { 1042 simple_unlock(&vp->v_interlock); 1043 ra = uvm_ra_allocctx(); 1044 simple_lock(&vp->v_interlock); 1045 if (ra != NULL && vp->v_ractx == NULL) { 1046 vp->v_ractx = ra; 1047 ra = NULL; 1048 } 1049 } 1050 simple_unlock(&vp->v_interlock); 1051 if (ra != NULL) { 1052 uvm_ra_freectx(ra); 1053 } 1054 } 1055