1 /* $NetBSD: vfs_vnops.c,v 1.104 2006/01/01 16:45:42 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 1.104 2006/01/01 16:45:42 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_segflg = segflg; 375 auio.uio_rw = rw; 376 auio.uio_lwp = l; 377 if (rw == UIO_READ) { 378 error = VOP_READ(vp, &auio, ioflg, cred); 379 } else { 380 error = VOP_WRITE(vp, &auio, ioflg, cred); 381 } 382 if (aresid) 383 *aresid = auio.uio_resid; 384 else 385 if (auio.uio_resid && error == 0) 386 error = EIO; 387 if ((ioflg & IO_NODELOCKED) == 0) { 388 if (rw == UIO_WRITE) 389 vn_finished_write(mp, 0); 390 VOP_UNLOCK(vp, 0); 391 } 392 return (error); 393 } 394 395 int 396 vn_readdir(struct file *fp, char *bf, int segflg, u_int count, int *done, 397 struct lwp *l, off_t **cookies, int *ncookies) 398 { 399 struct vnode *vp = (struct vnode *)fp->f_data; 400 struct iovec aiov; 401 struct uio auio; 402 int error, eofflag; 403 404 unionread: 405 if (vp->v_type != VDIR) 406 return (EINVAL); 407 aiov.iov_base = bf; 408 aiov.iov_len = count; 409 auio.uio_iov = &aiov; 410 auio.uio_iovcnt = 1; 411 auio.uio_rw = UIO_READ; 412 auio.uio_segflg = segflg; 413 auio.uio_lwp = l; 414 auio.uio_resid = count; 415 vn_lock(vp, LK_SHARED | LK_RETRY); 416 auio.uio_offset = fp->f_offset; 417 error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, cookies, 418 ncookies); 419 fp->f_offset = auio.uio_offset; 420 VOP_UNLOCK(vp, 0); 421 if (error) 422 return (error); 423 424 #if defined(UNION) || defined(LKM) 425 if (count == auio.uio_resid && vn_union_readdir_hook) { 426 struct vnode *ovp = vp; 427 428 error = (*vn_union_readdir_hook)(&vp, fp, l); 429 if (error) 430 return (error); 431 if (vp != ovp) 432 goto unionread; 433 } 434 #endif /* UNION || LKM */ 435 436 if (count == auio.uio_resid && (vp->v_flag & VROOT) && 437 (vp->v_mount->mnt_flag & MNT_UNION)) { 438 struct vnode *tvp = vp; 439 vp = vp->v_mount->mnt_vnodecovered; 440 VREF(vp); 441 fp->f_data = vp; 442 fp->f_offset = 0; 443 vrele(tvp); 444 goto unionread; 445 } 446 *done = count - auio.uio_resid; 447 return error; 448 } 449 450 /* 451 * File table vnode read routine. 452 */ 453 static int 454 vn_read(struct file *fp, off_t *offset, struct uio *uio, struct ucred *cred, 455 int flags) 456 { 457 struct vnode *vp = (struct vnode *)fp->f_data; 458 int count, error, ioflag; 459 460 VOP_LEASE(vp, uio->uio_lwp, cred, LEASE_READ); 461 ioflag = IO_ADV_ENCODE(fp->f_advice); 462 if (fp->f_flag & FNONBLOCK) 463 ioflag |= IO_NDELAY; 464 if ((fp->f_flag & (FFSYNC | FRSYNC)) == (FFSYNC | FRSYNC)) 465 ioflag |= IO_SYNC; 466 if (fp->f_flag & FALTIO) 467 ioflag |= IO_ALTSEMANTICS; 468 vn_lock(vp, LK_SHARED | LK_RETRY); 469 vn_ra_allocctx(vp); 470 uio->uio_offset = *offset; 471 count = uio->uio_resid; 472 error = VOP_READ(vp, uio, ioflag, cred); 473 if (flags & FOF_UPDATE_OFFSET) 474 *offset += count - uio->uio_resid; 475 VOP_UNLOCK(vp, 0); 476 return (error); 477 } 478 479 /* 480 * File table vnode write routine. 481 */ 482 static int 483 vn_write(struct file *fp, off_t *offset, struct uio *uio, struct ucred *cred, 484 int flags) 485 { 486 struct vnode *vp = (struct vnode *)fp->f_data; 487 struct mount *mp; 488 int count, error, ioflag = IO_UNIT; 489 490 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 491 ioflag |= IO_APPEND; 492 if (fp->f_flag & FNONBLOCK) 493 ioflag |= IO_NDELAY; 494 if (fp->f_flag & FFSYNC || 495 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS))) 496 ioflag |= IO_SYNC; 497 else if (fp->f_flag & FDSYNC) 498 ioflag |= IO_DSYNC; 499 if (fp->f_flag & FALTIO) 500 ioflag |= IO_ALTSEMANTICS; 501 mp = NULL; 502 if (vp->v_type != VCHR && 503 (error = vn_start_write(vp, &mp, V_WAIT | V_PCATCH)) != 0) 504 return (error); 505 VOP_LEASE(vp, uio->uio_lwp, cred, LEASE_WRITE); 506 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 507 uio->uio_offset = *offset; 508 count = uio->uio_resid; 509 error = VOP_WRITE(vp, uio, ioflag, cred); 510 if (flags & FOF_UPDATE_OFFSET) { 511 if (ioflag & IO_APPEND) 512 *offset = uio->uio_offset; 513 else 514 *offset += count - uio->uio_resid; 515 } 516 VOP_UNLOCK(vp, 0); 517 vn_finished_write(mp, 0); 518 return (error); 519 } 520 521 /* 522 * File table vnode stat routine. 523 */ 524 static int 525 vn_statfile(struct file *fp, struct stat *sb, struct lwp *l) 526 { 527 struct vnode *vp = (struct vnode *)fp->f_data; 528 529 return vn_stat(vp, sb, l); 530 } 531 532 int 533 vn_stat(struct vnode *vp, struct stat *sb, struct lwp *l) 534 { 535 struct vattr va; 536 int error; 537 mode_t mode; 538 539 error = VOP_GETATTR(vp, &va, l->l_proc->p_ucred, l); 540 if (error) 541 return (error); 542 /* 543 * Copy from vattr table 544 */ 545 sb->st_dev = va.va_fsid; 546 sb->st_ino = va.va_fileid; 547 mode = va.va_mode; 548 switch (vp->v_type) { 549 case VREG: 550 mode |= S_IFREG; 551 break; 552 case VDIR: 553 mode |= S_IFDIR; 554 break; 555 case VBLK: 556 mode |= S_IFBLK; 557 break; 558 case VCHR: 559 mode |= S_IFCHR; 560 break; 561 case VLNK: 562 mode |= S_IFLNK; 563 break; 564 case VSOCK: 565 mode |= S_IFSOCK; 566 break; 567 case VFIFO: 568 mode |= S_IFIFO; 569 break; 570 default: 571 return (EBADF); 572 }; 573 sb->st_mode = mode; 574 sb->st_nlink = va.va_nlink; 575 sb->st_uid = va.va_uid; 576 sb->st_gid = va.va_gid; 577 sb->st_rdev = va.va_rdev; 578 sb->st_size = va.va_size; 579 sb->st_atimespec = va.va_atime; 580 sb->st_mtimespec = va.va_mtime; 581 sb->st_ctimespec = va.va_ctime; 582 sb->st_birthtimespec = va.va_birthtime; 583 sb->st_blksize = va.va_blocksize; 584 sb->st_flags = va.va_flags; 585 sb->st_gen = 0; 586 sb->st_blocks = va.va_bytes / S_BLKSIZE; 587 return (0); 588 } 589 590 /* 591 * File table vnode fcntl routine. 592 */ 593 static int 594 vn_fcntl(struct file *fp, u_int com, void *data, struct lwp *l) 595 { 596 struct vnode *vp = ((struct vnode *)fp->f_data); 597 int error; 598 599 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 600 error = VOP_FCNTL(vp, com, data, fp->f_flag, l->l_proc->p_ucred, l); 601 VOP_UNLOCK(vp, 0); 602 return (error); 603 } 604 605 /* 606 * File table vnode ioctl routine. 607 */ 608 static int 609 vn_ioctl(struct file *fp, u_long com, void *data, struct lwp *l) 610 { 611 struct vnode *vp = ((struct vnode *)fp->f_data); 612 struct proc *p = l->l_proc; 613 struct vattr vattr; 614 int error; 615 616 switch (vp->v_type) { 617 618 case VREG: 619 case VDIR: 620 if (com == FIONREAD) { 621 error = VOP_GETATTR(vp, &vattr, l->l_proc->p_ucred, l); 622 if (error) 623 return (error); 624 *(int *)data = vattr.va_size - fp->f_offset; 625 return (0); 626 } 627 if ((com == FIONWRITE) || (com == FIONSPACE)) { 628 /* 629 * Files don't have send queues, so there never 630 * are any bytes in them, nor is there any 631 * open space in them. 632 */ 633 *(int *)data = 0; 634 return (0); 635 } 636 if (com == FIOGETBMAP) { 637 daddr_t *block; 638 639 if (*(daddr_t *)data < 0) 640 return (EINVAL); 641 block = (daddr_t *)data; 642 return (VOP_BMAP(vp, *block, NULL, block, NULL)); 643 } 644 if (com == OFIOGETBMAP) { 645 daddr_t ibn, obn; 646 647 if (*(int32_t *)data < 0) 648 return (EINVAL); 649 ibn = (daddr_t)*(int32_t *)data; 650 error = VOP_BMAP(vp, ibn, NULL, &obn, NULL); 651 *(int32_t *)data = (int32_t)obn; 652 return error; 653 } 654 if (com == FIONBIO || com == FIOASYNC) /* XXX */ 655 return (0); /* XXX */ 656 /* fall into ... */ 657 case VFIFO: 658 case VCHR: 659 case VBLK: 660 error = VOP_IOCTL(vp, com, data, fp->f_flag, 661 l->l_proc->p_ucred, l); 662 if (error == 0 && com == TIOCSCTTY) { 663 if (p->p_session->s_ttyvp) 664 vrele(p->p_session->s_ttyvp); 665 p->p_session->s_ttyvp = vp; 666 VREF(vp); 667 } 668 return (error); 669 670 default: 671 return (EPASSTHROUGH); 672 } 673 } 674 675 /* 676 * File table vnode poll routine. 677 */ 678 static int 679 vn_poll(struct file *fp, int events, struct lwp *l) 680 { 681 682 return (VOP_POLL(((struct vnode *)fp->f_data), events, l)); 683 } 684 685 /* 686 * File table vnode kqfilter routine. 687 */ 688 int 689 vn_kqfilter(struct file *fp, struct knote *kn) 690 { 691 692 return (VOP_KQFILTER((struct vnode *)fp->f_data, kn)); 693 } 694 695 /* 696 * Check that the vnode is still valid, and if so 697 * acquire requested lock. 698 */ 699 int 700 vn_lock(struct vnode *vp, int flags) 701 { 702 int error; 703 704 #if 0 705 KASSERT(vp->v_usecount > 0 || (flags & LK_INTERLOCK) != 0 706 || (vp->v_flag & VONWORKLST) != 0); 707 #endif 708 KASSERT((flags & 709 ~(LK_INTERLOCK|LK_SHARED|LK_EXCLUSIVE|LK_DRAIN|LK_NOWAIT|LK_RETRY| 710 LK_SETRECURSE|LK_CANRECURSE)) 711 == 0); 712 713 do { 714 if ((flags & LK_INTERLOCK) == 0) 715 simple_lock(&vp->v_interlock); 716 if (vp->v_flag & VXLOCK) { 717 if (flags & LK_NOWAIT) { 718 simple_unlock(&vp->v_interlock); 719 return EBUSY; 720 } 721 vp->v_flag |= VXWANT; 722 ltsleep(vp, PINOD | PNORELOCK, 723 "vn_lock", 0, &vp->v_interlock); 724 error = ENOENT; 725 } else { 726 error = VOP_LOCK(vp, 727 (flags & ~LK_RETRY) | LK_INTERLOCK); 728 if (error == 0 || error == EDEADLK || error == EBUSY) 729 return (error); 730 } 731 flags &= ~LK_INTERLOCK; 732 } while (flags & LK_RETRY); 733 return (error); 734 } 735 736 /* 737 * File table vnode close routine. 738 */ 739 static int 740 vn_closefile(struct file *fp, struct lwp *l) 741 { 742 743 return (vn_close(((struct vnode *)fp->f_data), fp->f_flag, 744 fp->f_cred, l)); 745 } 746 747 /* 748 * Enable LK_CANRECURSE on lock. Return prior status. 749 */ 750 u_int 751 vn_setrecurse(struct vnode *vp) 752 { 753 struct lock *lkp = &vp->v_lock; 754 u_int retval = lkp->lk_flags & LK_CANRECURSE; 755 756 lkp->lk_flags |= LK_CANRECURSE; 757 return retval; 758 } 759 760 /* 761 * Called when done with locksetrecurse. 762 */ 763 void 764 vn_restorerecurse(struct vnode *vp, u_int flags) 765 { 766 struct lock *lkp = &vp->v_lock; 767 768 lkp->lk_flags &= ~LK_CANRECURSE; 769 lkp->lk_flags |= flags; 770 } 771 772 int 773 vn_cow_establish(struct vnode *vp, 774 int (*func)(void *, struct buf *), void *cookie) 775 { 776 int s; 777 struct spec_cow_entry *e; 778 779 MALLOC(e, struct spec_cow_entry *, sizeof(struct spec_cow_entry), 780 M_DEVBUF, M_WAITOK); 781 e->ce_func = func; 782 e->ce_cookie = cookie; 783 784 SPEC_COW_LOCK(vp->v_specinfo, s); 785 vp->v_spec_cow_req++; 786 while (vp->v_spec_cow_count > 0) 787 ltsleep(&vp->v_spec_cow_req, PRIBIO, "cowlist", 0, 788 &vp->v_spec_cow_slock); 789 790 SLIST_INSERT_HEAD(&vp->v_spec_cow_head, e, ce_list); 791 792 vp->v_spec_cow_req--; 793 if (vp->v_spec_cow_req == 0) 794 wakeup(&vp->v_spec_cow_req); 795 SPEC_COW_UNLOCK(vp->v_specinfo, s); 796 797 return 0; 798 } 799 800 int 801 vn_cow_disestablish(struct vnode *vp, 802 int (*func)(void *, struct buf *), void *cookie) 803 { 804 int s; 805 struct spec_cow_entry *e; 806 807 SPEC_COW_LOCK(vp->v_specinfo, s); 808 vp->v_spec_cow_req++; 809 while (vp->v_spec_cow_count > 0) 810 ltsleep(&vp->v_spec_cow_req, PRIBIO, "cowlist", 0, 811 &vp->v_spec_cow_slock); 812 813 SLIST_FOREACH(e, &vp->v_spec_cow_head, ce_list) 814 if (e->ce_func == func && e->ce_cookie == cookie) { 815 SLIST_REMOVE(&vp->v_spec_cow_head, e, 816 spec_cow_entry, ce_list); 817 FREE(e, M_DEVBUF); 818 break; 819 } 820 821 vp->v_spec_cow_req--; 822 if (vp->v_spec_cow_req == 0) 823 wakeup(&vp->v_spec_cow_req); 824 SPEC_COW_UNLOCK(vp->v_specinfo, s); 825 826 return e ? 0 : EINVAL; 827 } 828 829 /* 830 * Simplified in-kernel wrapper calls for extended attribute access. 831 * Both calls pass in a NULL credential, authorizing a "kernel" access. 832 * Set IO_NODELOCKED in ioflg if the vnode is already locked. 833 */ 834 int 835 vn_extattr_get(struct vnode *vp, int ioflg, int attrnamespace, 836 const char *attrname, size_t *buflen, void *bf, struct lwp *l) 837 { 838 struct uio auio; 839 struct iovec aiov; 840 int error; 841 842 aiov.iov_len = *buflen; 843 aiov.iov_base = bf; 844 845 auio.uio_iov = &aiov; 846 auio.uio_iovcnt = 1; 847 auio.uio_rw = UIO_READ; 848 auio.uio_segflg = UIO_SYSSPACE; 849 auio.uio_lwp = l; 850 auio.uio_offset = 0; 851 auio.uio_resid = *buflen; 852 853 if ((ioflg & IO_NODELOCKED) == 0) 854 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 855 856 error = VOP_GETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, NULL, 857 l); 858 859 if ((ioflg & IO_NODELOCKED) == 0) 860 VOP_UNLOCK(vp, 0); 861 862 if (error == 0) 863 *buflen = *buflen - auio.uio_resid; 864 865 return (error); 866 } 867 868 /* 869 * XXX Failure mode if partially written? 870 */ 871 int 872 vn_extattr_set(struct vnode *vp, int ioflg, int attrnamespace, 873 const char *attrname, size_t buflen, const void *bf, struct lwp *l) 874 { 875 struct uio auio; 876 struct iovec aiov; 877 struct mount *mp; 878 int error; 879 880 aiov.iov_len = buflen; 881 aiov.iov_base = __UNCONST(bf); /* XXXUNCONST kills const */ 882 883 auio.uio_iov = &aiov; 884 auio.uio_iovcnt = 1; 885 auio.uio_rw = UIO_WRITE; 886 auio.uio_segflg = UIO_SYSSPACE; 887 auio.uio_lwp = l; 888 auio.uio_offset = 0; 889 auio.uio_resid = buflen; 890 891 if ((ioflg & IO_NODELOCKED) == 0) { 892 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) 893 return (error); 894 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 895 } 896 897 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, l); 898 899 if ((ioflg & IO_NODELOCKED) == 0) { 900 vn_finished_write(mp, 0); 901 VOP_UNLOCK(vp, 0); 902 } 903 904 return (error); 905 } 906 907 int 908 vn_extattr_rm(struct vnode *vp, int ioflg, int attrnamespace, 909 const char *attrname, struct lwp *l) 910 { 911 struct mount *mp; 912 int error; 913 914 if ((ioflg & IO_NODELOCKED) == 0) { 915 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) 916 return (error); 917 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 918 } 919 920 error = VOP_DELETEEXTATTR(vp, attrnamespace, attrname, NULL, l); 921 if (error == EOPNOTSUPP) 922 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, NULL, 923 NULL, l); 924 925 if ((ioflg & IO_NODELOCKED) == 0) { 926 vn_finished_write(mp, 0); 927 VOP_UNLOCK(vp, 0); 928 } 929 930 return (error); 931 } 932 933 /* 934 * Preparing to start a filesystem write operation. If the operation is 935 * permitted, then we bump the count of operations in progress and 936 * proceed. If a suspend request is in progress, we wait until the 937 * suspension is over, and then proceed. 938 * V_PCATCH adds PCATCH to the tsleep flags. 939 * V_WAIT waits until suspension is over. Otherwise returns EWOULDBLOCK. 940 * V_SLEEPONLY wait, but do not bump the operations count. 941 * V_LOWER this is a lower level operation. No further vnodes should be 942 * locked. Otherwise it is a upper level operation. No vnodes 943 * should be locked. 944 */ 945 int 946 vn_start_write(struct vnode *vp, struct mount **mpp, int flags) 947 { 948 struct mount *mp; 949 int error, mask, prio; 950 951 /* 952 * If a vnode is provided, get and return the mount point that 953 * to which it will write. 954 */ 955 if (vp != NULL) { 956 *mpp = vp->v_mount; 957 } 958 if ((mp = *mpp) == NULL) 959 return (0); 960 mp = mp->mnt_leaf; 961 /* 962 * Check on status of suspension. 963 */ 964 prio = PUSER - 1; 965 if (flags & V_PCATCH) 966 prio |= PCATCH; 967 968 if ((flags & V_LOWER) == 0) 969 mask = IMNT_SUSPEND; 970 else 971 mask = IMNT_SUSPENDLOW; 972 973 while ((mp->mnt_iflag & mask) != 0) { 974 if ((flags & V_WAIT) == 0) 975 return (EWOULDBLOCK); 976 error = tsleep(&mp->mnt_flag, prio, "suspfs", 0); 977 if (error) 978 return (error); 979 } 980 if (flags & V_SLEEPONLY) 981 return (0); 982 simple_lock(&mp->mnt_slock); 983 if ((flags & V_LOWER) == 0) 984 mp->mnt_writeopcountupper++; 985 else 986 mp->mnt_writeopcountlower++; 987 simple_unlock(&mp->mnt_slock); 988 return (0); 989 } 990 991 /* 992 * Filesystem write operation has completed. If we are suspending and this 993 * operation is the last one, notify the suspender that the suspension is 994 * now in effect. 995 */ 996 void 997 vn_finished_write(struct mount *mp, int flags) 998 { 999 if (mp == NULL) 1000 return; 1001 mp = mp->mnt_leaf; 1002 simple_lock(&mp->mnt_slock); 1003 if ((flags & V_LOWER) == 0) { 1004 mp->mnt_writeopcountupper--; 1005 if (mp->mnt_writeopcountupper < 0) 1006 printf("vn_finished_write: neg cnt upper=%d\n", 1007 mp->mnt_writeopcountupper); 1008 if ((mp->mnt_iflag & IMNT_SUSPEND) != 0 && 1009 mp->mnt_writeopcountupper <= 0) 1010 wakeup(&mp->mnt_writeopcountupper); 1011 } else { 1012 mp->mnt_writeopcountlower--; 1013 if (mp->mnt_writeopcountlower < 0) 1014 printf("vn_finished_write: neg cnt lower=%d\n", 1015 mp->mnt_writeopcountlower); 1016 if ((mp->mnt_iflag & IMNT_SUSPENDLOW) != 0 && 1017 mp->mnt_writeopcountupper <= 0) 1018 wakeup(&mp->mnt_writeopcountlower); 1019 } 1020 simple_unlock(&mp->mnt_slock); 1021 } 1022 1023 void 1024 vn_ra_allocctx(struct vnode *vp) 1025 { 1026 struct uvm_ractx *ra = NULL; 1027 1028 if (vp->v_type != VREG) { 1029 return; 1030 } 1031 if (vp->v_ractx != NULL) { 1032 return; 1033 } 1034 simple_lock(&vp->v_interlock); 1035 if (vp->v_ractx == NULL) { 1036 simple_unlock(&vp->v_interlock); 1037 ra = uvm_ra_allocctx(); 1038 simple_lock(&vp->v_interlock); 1039 if (ra != NULL && vp->v_ractx == NULL) { 1040 vp->v_ractx = ra; 1041 ra = NULL; 1042 } 1043 } 1044 simple_unlock(&vp->v_interlock); 1045 if (ra != NULL) { 1046 uvm_ra_freectx(ra); 1047 } 1048 } 1049