vfs_vnops.c revision 1.48.4.2
1 /* $NetBSD: vfs_vnops.c,v 1.48.4.2 2001/10/01 12:47:02 fvdl 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. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by the University of 23 * California, Berkeley and its contributors. 24 * 4. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 * 40 * @(#)vfs_vnops.c 8.14 (Berkeley) 6/15/95 41 */ 42 43 #include "fs_union.h" 44 45 #include <sys/param.h> 46 #include <sys/systm.h> 47 #include <sys/kernel.h> 48 #include <sys/file.h> 49 #include <sys/stat.h> 50 #include <sys/buf.h> 51 #include <sys/proc.h> 52 #include <sys/mount.h> 53 #include <sys/namei.h> 54 #include <sys/vnode.h> 55 #include <sys/ioctl.h> 56 #include <sys/tty.h> 57 #include <sys/poll.h> 58 59 #include <uvm/uvm_extern.h> 60 61 #ifdef UNION 62 #include <miscfs/union/union.h> 63 #endif 64 65 static int vn_statfile __P((struct file *fp, struct stat *sb, struct proc *p)); 66 67 struct fileops vnops = { 68 vn_read, vn_write, vn_ioctl, vn_fcntl, vn_poll, 69 vn_statfile, vn_closefile 70 }; 71 72 /* 73 * Common code for vnode open operations. 74 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine. 75 */ 76 int 77 vn_open(ndp, fmode, cmode) 78 struct nameidata *ndp; 79 int fmode, cmode; 80 { 81 struct vnode *vp, *vp2; 82 struct proc *p = ndp->ni_cnd.cn_proc; 83 struct ucred *cred = p->p_ucred; 84 struct vattr va; 85 int error; 86 87 if (fmode & O_CREAT) { 88 ndp->ni_cnd.cn_nameiop = CREATE; 89 ndp->ni_cnd.cn_flags = LOCKPARENT | LOCKLEAF; 90 if ((fmode & O_EXCL) == 0 && 91 ((fmode & FNOSYMLINK) == 0)) 92 ndp->ni_cnd.cn_flags |= FOLLOW; 93 if ((error = namei(ndp)) != 0) 94 return (error); 95 if (ndp->ni_vp == NULL) { 96 VATTR_NULL(&va); 97 va.va_type = VREG; 98 va.va_mode = cmode; 99 if (fmode & O_EXCL) 100 va.va_vaflags |= VA_EXCLUSIVE; 101 VOP_LEASE(ndp->ni_dvp, p, cred, LEASE_WRITE); 102 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp, 103 &ndp->ni_cnd, &va); 104 if (error) 105 return (error); 106 fmode &= ~O_TRUNC; 107 vp = ndp->ni_vp; 108 } else { 109 VOP_ABORTOP(ndp->ni_dvp, &ndp->ni_cnd); 110 if (ndp->ni_dvp == ndp->ni_vp) 111 vrele(ndp->ni_dvp); 112 else 113 vput(ndp->ni_dvp); 114 ndp->ni_dvp = NULL; 115 vp = ndp->ni_vp; 116 if (fmode & O_EXCL) { 117 error = EEXIST; 118 goto bad; 119 } 120 if (ndp->ni_vp->v_type == VLNK) { 121 error = EFTYPE; 122 goto bad; 123 } 124 fmode &= ~O_CREAT; 125 } 126 } else { 127 ndp->ni_cnd.cn_nameiop = LOOKUP; 128 ndp->ni_cnd.cn_flags = FOLLOW | LOCKLEAF; 129 if ((error = namei(ndp)) != 0) 130 return (error); 131 vp = ndp->ni_vp; 132 } 133 if (vp->v_type == VSOCK) { 134 error = EOPNOTSUPP; 135 goto bad; 136 } 137 if ((fmode & O_CREAT) == 0) { 138 if (fmode & FREAD) { 139 if ((error = VOP_ACCESS(vp, VREAD, cred, p)) != 0) 140 goto bad; 141 } 142 if (fmode & (FWRITE | O_TRUNC)) { 143 if (vp->v_type == VDIR) { 144 error = EISDIR; 145 goto bad; 146 } 147 if ((error = vn_writechk(vp)) != 0 || 148 (error = VOP_ACCESS(vp, VWRITE, cred, p)) != 0) 149 goto bad; 150 } 151 } 152 if (fmode & O_TRUNC) { 153 VOP_UNLOCK(vp, 0); /* XXX */ 154 VOP_LEASE(vp, p, cred, LEASE_WRITE); 155 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); /* XXX */ 156 VATTR_NULL(&va); 157 va.va_size = 0; 158 if ((error = VOP_SETATTR(vp, &va, cred, p)) != 0) 159 goto bad; 160 } 161 vp2 = NULL; 162 if ((error = VOP_OPEN(vp, fmode, cred, p, &vp2)) != 0) 163 goto bad; 164 if (vp2 != NULL) { 165 vput(vp); 166 ndp->ni_vp = vp = vp2; 167 } 168 169 if (vp->v_type == VREG && 170 uvn_attach(vp, fmode & FWRITE ? VM_PROT_WRITE : 0) == NULL) { 171 error = EIO; 172 goto bad; 173 } 174 if (fmode & FWRITE) 175 vp->v_writecount++; 176 177 return (0); 178 bad: 179 vput(vp); 180 return (error); 181 } 182 183 /* 184 * Check for write permissions on the specified vnode. 185 * Prototype text segments cannot be written. 186 */ 187 int 188 vn_writechk(vp) 189 struct vnode *vp; 190 { 191 192 /* 193 * If the vnode is in use as a process's text, 194 * we can't allow writing. 195 */ 196 if (vp->v_flag & VTEXT) 197 return (ETXTBSY); 198 return (0); 199 } 200 201 /* 202 * Mark a vnode as being the text image of a running process. 203 */ 204 void 205 vn_marktext(vp) 206 struct vnode *vp; 207 { 208 if ((vp->v_flag & VTEXT) == 0) { 209 uvmexp.vnodepages -= vp->v_uobj.uo_npages; 210 uvmexp.vtextpages += vp->v_uobj.uo_npages; 211 } 212 vp->v_flag |= VTEXT; 213 } 214 215 /* 216 * Vnode close call 217 * 218 * Note: takes an unlocked vnode, while VOP_CLOSE takes a locked node. 219 */ 220 int 221 vn_close(vp, flags, cred, p) 222 struct vnode *vp; 223 int flags; 224 struct ucred *cred; 225 struct proc *p; 226 { 227 int error; 228 229 if (flags & FWRITE) 230 vp->v_writecount--; 231 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 232 error = VOP_CLOSE(vp, flags, cred, p); 233 vput(vp); 234 return (error); 235 } 236 237 /* 238 * Package up an I/O request on a vnode into a uio and do it. 239 */ 240 int 241 vn_rdwr(rw, vp, base, len, offset, segflg, ioflg, cred, aresid, p) 242 enum uio_rw rw; 243 struct vnode *vp; 244 caddr_t base; 245 int len; 246 off_t offset; 247 enum uio_seg segflg; 248 int ioflg; 249 struct ucred *cred; 250 size_t *aresid; 251 struct proc *p; 252 { 253 struct uio auio; 254 struct iovec aiov; 255 int error; 256 257 if ((ioflg & IO_NODELOCKED) == 0) { 258 if (rw == UIO_READ) { 259 vn_lock(vp, LK_SHARED | LK_RETRY); 260 } else { 261 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 262 } 263 } 264 auio.uio_iov = &aiov; 265 auio.uio_iovcnt = 1; 266 aiov.iov_base = base; 267 aiov.iov_len = len; 268 auio.uio_resid = len; 269 auio.uio_offset = offset; 270 auio.uio_segflg = segflg; 271 auio.uio_rw = rw; 272 auio.uio_procp = p; 273 if (rw == UIO_READ) { 274 error = VOP_READ(vp, &auio, ioflg, cred); 275 } else { 276 error = VOP_WRITE(vp, &auio, ioflg, cred); 277 } 278 if (aresid) 279 *aresid = auio.uio_resid; 280 else 281 if (auio.uio_resid && error == 0) 282 error = EIO; 283 if ((ioflg & IO_NODELOCKED) == 0) 284 VOP_UNLOCK(vp, 0); 285 return (error); 286 } 287 288 int 289 vn_readdir(fp, buf, segflg, count, done, p, cookies, ncookies) 290 struct file *fp; 291 char *buf; 292 int segflg, *done, *ncookies; 293 u_int count; 294 struct proc *p; 295 off_t **cookies; 296 { 297 struct vnode *vp = (struct vnode *)fp->f_data; 298 struct iovec aiov; 299 struct uio auio; 300 int error, eofflag; 301 302 unionread: 303 if (vp->v_type != VDIR) 304 return (EINVAL); 305 aiov.iov_base = buf; 306 aiov.iov_len = count; 307 auio.uio_iov = &aiov; 308 auio.uio_iovcnt = 1; 309 auio.uio_rw = UIO_READ; 310 auio.uio_segflg = segflg; 311 auio.uio_procp = p; 312 auio.uio_resid = count; 313 vn_lock(vp, LK_SHARED | LK_RETRY); 314 auio.uio_offset = fp->f_offset; 315 error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, cookies, 316 ncookies); 317 fp->f_offset = auio.uio_offset; 318 VOP_UNLOCK(vp, 0); 319 if (error) 320 return (error); 321 322 #ifdef UNION 323 { 324 extern struct vnode *union_dircache __P((struct vnode *)); 325 326 if (count == auio.uio_resid && (vp->v_op == union_vnodeop_p)) { 327 struct vnode *lvp; 328 329 lvp = union_dircache(vp); 330 if (lvp != NULLVP) { 331 struct vattr va; 332 333 /* 334 * If the directory is opaque, 335 * then don't show lower entries 336 */ 337 error = VOP_GETATTR(vp, &va, fp->f_cred, p); 338 if (va.va_flags & OPAQUE) { 339 vput(lvp); 340 lvp = NULL; 341 } 342 } 343 344 if (lvp != NULLVP) { 345 error = VOP_OPEN(lvp, FREAD, fp->f_cred, p, NULL); 346 if (error) { 347 vput(lvp); 348 return (error); 349 } 350 VOP_UNLOCK(lvp, 0); 351 fp->f_data = (caddr_t) lvp; 352 fp->f_offset = 0; 353 error = vn_close(vp, FREAD, fp->f_cred, p); 354 if (error) 355 return (error); 356 vp = lvp; 357 goto unionread; 358 } 359 } 360 } 361 #endif /* UNION */ 362 363 if (count == auio.uio_resid && (vp->v_flag & VROOT) && 364 (vp->v_mount->mnt_flag & MNT_UNION)) { 365 struct vnode *tvp = vp; 366 vp = vp->v_mount->mnt_vnodecovered; 367 VREF(vp); 368 fp->f_data = (caddr_t) vp; 369 fp->f_offset = 0; 370 vrele(tvp); 371 goto unionread; 372 } 373 *done = count - auio.uio_resid; 374 return error; 375 } 376 377 /* 378 * File table vnode read routine. 379 */ 380 int 381 vn_read(fp, offset, uio, cred, flags) 382 struct file *fp; 383 off_t *offset; 384 struct uio *uio; 385 struct ucred *cred; 386 int flags; 387 { 388 struct vnode *vp = (struct vnode *)fp->f_data; 389 int count, error, ioflag = 0; 390 391 VOP_LEASE(vp, uio->uio_procp, cred, LEASE_READ); 392 if (fp->f_flag & FNONBLOCK) 393 ioflag |= IO_NDELAY; 394 if ((fp->f_flag & (FFSYNC | FRSYNC)) == (FFSYNC | FRSYNC)) 395 ioflag |= IO_SYNC; 396 if (fp->f_flag & FALTIO) 397 ioflag |= IO_ALTSEMANTICS; 398 vn_lock(vp, LK_SHARED | LK_RETRY); 399 uio->uio_offset = *offset; 400 count = uio->uio_resid; 401 error = VOP_READ(vp, uio, ioflag, cred); 402 if (flags & FOF_UPDATE_OFFSET) 403 *offset += count - uio->uio_resid; 404 VOP_UNLOCK(vp, 0); 405 return (error); 406 } 407 408 /* 409 * File table vnode write routine. 410 */ 411 int 412 vn_write(fp, offset, uio, cred, flags) 413 struct file *fp; 414 off_t *offset; 415 struct uio *uio; 416 struct ucred *cred; 417 int flags; 418 { 419 struct vnode *vp = (struct vnode *)fp->f_data; 420 int count, error, ioflag = IO_UNIT; 421 422 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 423 ioflag |= IO_APPEND; 424 if (fp->f_flag & FNONBLOCK) 425 ioflag |= IO_NDELAY; 426 if (fp->f_flag & FFSYNC || 427 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS))) 428 ioflag |= IO_SYNC; 429 else if (fp->f_flag & FDSYNC) 430 ioflag |= IO_DSYNC; 431 if (fp->f_flag & FALTIO) 432 ioflag |= IO_ALTSEMANTICS; 433 VOP_LEASE(vp, uio->uio_procp, cred, LEASE_WRITE); 434 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 435 uio->uio_offset = *offset; 436 count = uio->uio_resid; 437 error = VOP_WRITE(vp, uio, ioflag, cred); 438 if (flags & FOF_UPDATE_OFFSET) { 439 if (ioflag & IO_APPEND) 440 *offset = uio->uio_offset; 441 else 442 *offset += count - uio->uio_resid; 443 } 444 VOP_UNLOCK(vp, 0); 445 return (error); 446 } 447 448 /* 449 * File table vnode stat routine. 450 */ 451 static int 452 vn_statfile(fp, sb, p) 453 struct file *fp; 454 struct stat *sb; 455 struct proc *p; 456 { 457 struct vnode *vp = (struct vnode *)fp->f_data; 458 459 return vn_stat(vp, sb, p); 460 } 461 462 int 463 vn_stat(fdata, sb, p) 464 void *fdata; 465 struct stat *sb; 466 struct proc *p; 467 { 468 struct vnode *vp = fdata; 469 struct vattr va; 470 int error; 471 mode_t mode; 472 473 error = VOP_GETATTR(vp, &va, p->p_ucred, p); 474 if (error) 475 return (error); 476 /* 477 * Copy from vattr table 478 */ 479 sb->st_dev = va.va_fsid; 480 sb->st_ino = va.va_fileid; 481 mode = va.va_mode; 482 switch (vp->v_type) { 483 case VREG: 484 mode |= S_IFREG; 485 break; 486 case VDIR: 487 mode |= S_IFDIR; 488 break; 489 case VBLK: 490 mode |= S_IFBLK; 491 break; 492 case VCHR: 493 mode |= S_IFCHR; 494 break; 495 case VLNK: 496 mode |= S_IFLNK; 497 break; 498 case VSOCK: 499 mode |= S_IFSOCK; 500 break; 501 case VFIFO: 502 mode |= S_IFIFO; 503 break; 504 default: 505 return (EBADF); 506 }; 507 sb->st_mode = mode; 508 sb->st_nlink = va.va_nlink; 509 sb->st_uid = va.va_uid; 510 sb->st_gid = va.va_gid; 511 sb->st_rdev = va.va_rdev; 512 sb->st_size = va.va_size; 513 sb->st_atimespec = va.va_atime; 514 sb->st_mtimespec = va.va_mtime; 515 sb->st_ctimespec = va.va_ctime; 516 sb->st_blksize = va.va_blocksize; 517 sb->st_flags = va.va_flags; 518 sb->st_gen = 0; 519 sb->st_blocks = va.va_bytes / S_BLKSIZE; 520 return (0); 521 } 522 523 /* 524 * File table vnode fcntl routine. 525 */ 526 int 527 vn_fcntl(fp, com, data, p) 528 struct file *fp; 529 u_int com; 530 caddr_t data; 531 struct proc *p; 532 { 533 struct vnode *vp = ((struct vnode *)fp->f_data); 534 int error; 535 536 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 537 error = VOP_FCNTL(vp, com, data, fp->f_flag, p->p_ucred, p); 538 VOP_UNLOCK(vp, 0); 539 return (error); 540 } 541 542 /* 543 * File table vnode ioctl routine. 544 */ 545 int 546 vn_ioctl(fp, com, data, p) 547 struct file *fp; 548 u_long com; 549 caddr_t data; 550 struct proc *p; 551 { 552 struct vnode *vp = ((struct vnode *)fp->f_data); 553 struct vattr vattr; 554 int error; 555 556 switch (vp->v_type) { 557 558 case VREG: 559 case VDIR: 560 if (com == FIONREAD) { 561 error = VOP_GETATTR(vp, &vattr, p->p_ucred, p); 562 if (error) 563 return (error); 564 *(int *)data = vattr.va_size - fp->f_offset; 565 return (0); 566 } 567 if (com == FIONBIO || com == FIOASYNC) /* XXX */ 568 return (0); /* XXX */ 569 /* fall into ... */ 570 571 default: 572 return (ENOTTY); 573 574 case VFIFO: 575 case VCHR: 576 case VBLK: 577 error = VOP_IOCTL(vp, com, data, fp->f_flag, p->p_ucred, p); 578 if (error == 0 && com == TIOCSCTTY) { 579 if (p->p_session->s_ttyvp) 580 vrele(p->p_session->s_ttyvp); 581 p->p_session->s_ttyvp = vp; 582 VREF(vp); 583 } 584 return (error); 585 } 586 } 587 588 /* 589 * File table vnode poll routine. 590 */ 591 int 592 vn_poll(fp, events, p) 593 struct file *fp; 594 int events; 595 struct proc *p; 596 { 597 598 return (VOP_POLL(((struct vnode *)fp->f_data), events, p)); 599 } 600 601 /* 602 * Check that the vnode is still valid, and if so 603 * acquire requested lock. 604 */ 605 int 606 vn_lock(vp, flags) 607 struct vnode *vp; 608 int flags; 609 { 610 int error; 611 612 do { 613 if ((flags & LK_INTERLOCK) == 0) 614 simple_lock(&vp->v_interlock); 615 if (vp->v_flag & VXLOCK) { 616 if (flags & LK_NOWAIT) { 617 simple_unlock(&vp->v_interlock); 618 return EBUSY; 619 } 620 vp->v_flag |= VXWANT; 621 ltsleep(vp, PINOD | PNORELOCK, 622 "vn_lock", 0, &vp->v_interlock); 623 error = ENOENT; 624 } else { 625 error = VOP_LOCK(vp, flags | LK_INTERLOCK); 626 if (error == 0 || error == EDEADLK || error == EBUSY) 627 return (error); 628 } 629 flags &= ~LK_INTERLOCK; 630 } while (flags & LK_RETRY); 631 return (error); 632 } 633 634 /* 635 * File table vnode close routine. 636 */ 637 int 638 vn_closefile(fp, p) 639 struct file *fp; 640 struct proc *p; 641 { 642 643 return (vn_close(((struct vnode *)fp->f_data), fp->f_flag, 644 fp->f_cred, p)); 645 } 646 647 /* 648 * Enable LK_CANRECURSE on lock. Return prior status. 649 */ 650 u_int 651 vn_setrecurse(vp) 652 struct vnode *vp; 653 { 654 struct lock *lkp = &vp->v_lock; 655 u_int retval = lkp->lk_flags & LK_CANRECURSE; 656 657 lkp->lk_flags |= LK_CANRECURSE; 658 return retval; 659 } 660 661 /* 662 * Called when done with locksetrecurse. 663 */ 664 void 665 vn_restorerecurse(vp, flags) 666 struct vnode *vp; 667 u_int flags; 668 { 669 struct lock *lkp = &vp->v_lock; 670 671 lkp->lk_flags &= ~LK_CANRECURSE; 672 lkp->lk_flags |= flags; 673 } 674
Indexes created Wed Sep 24 05:09:52 GMT 2025