vfs_vnops.c revision 1.48.4.1
1 /* $NetBSD: vfs_vnops.c,v 1.48.4.1 2001/09/18 19:13:55 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_uvm.u_obj.uo_npages; 210 uvmexp.vtextpages += vp->v_uvm.u_obj.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 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 259 auio.uio_iov = &aiov; 260 auio.uio_iovcnt = 1; 261 aiov.iov_base = base; 262 aiov.iov_len = len; 263 auio.uio_resid = len; 264 auio.uio_offset = offset; 265 auio.uio_segflg = segflg; 266 auio.uio_rw = rw; 267 auio.uio_procp = p; 268 if (rw == UIO_READ) { 269 error = VOP_READ(vp, &auio, ioflg, cred); 270 } else { 271 error = VOP_WRITE(vp, &auio, ioflg, cred); 272 } 273 if (aresid) 274 *aresid = auio.uio_resid; 275 else 276 if (auio.uio_resid && error == 0) 277 error = EIO; 278 if ((ioflg & IO_NODELOCKED) == 0) 279 VOP_UNLOCK(vp, 0); 280 return (error); 281 } 282 283 int 284 vn_readdir(fp, buf, segflg, count, done, p, cookies, ncookies) 285 struct file *fp; 286 char *buf; 287 int segflg, *done, *ncookies; 288 u_int count; 289 struct proc *p; 290 off_t **cookies; 291 { 292 struct vnode *vp = (struct vnode *)fp->f_data; 293 struct iovec aiov; 294 struct uio auio; 295 int error, eofflag; 296 297 unionread: 298 if (vp->v_type != VDIR) 299 return (EINVAL); 300 aiov.iov_base = buf; 301 aiov.iov_len = count; 302 auio.uio_iov = &aiov; 303 auio.uio_iovcnt = 1; 304 auio.uio_rw = UIO_READ; 305 auio.uio_segflg = segflg; 306 auio.uio_procp = p; 307 auio.uio_resid = count; 308 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 309 auio.uio_offset = fp->f_offset; 310 error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, cookies, 311 ncookies); 312 fp->f_offset = auio.uio_offset; 313 VOP_UNLOCK(vp, 0); 314 if (error) 315 return (error); 316 317 #ifdef UNION 318 { 319 extern struct vnode *union_dircache __P((struct vnode *)); 320 321 if (count == auio.uio_resid && (vp->v_op == union_vnodeop_p)) { 322 struct vnode *lvp; 323 324 lvp = union_dircache(vp); 325 if (lvp != NULLVP) { 326 struct vattr va; 327 328 /* 329 * If the directory is opaque, 330 * then don't show lower entries 331 */ 332 error = VOP_GETATTR(vp, &va, fp->f_cred, p); 333 if (va.va_flags & OPAQUE) { 334 vput(lvp); 335 lvp = NULL; 336 } 337 } 338 339 if (lvp != NULLVP) { 340 error = VOP_OPEN(lvp, FREAD, fp->f_cred, p, NULL); 341 if (error) { 342 vput(lvp); 343 return (error); 344 } 345 VOP_UNLOCK(lvp, 0); 346 fp->f_data = (caddr_t) lvp; 347 fp->f_offset = 0; 348 error = vn_close(vp, FREAD, fp->f_cred, p); 349 if (error) 350 return (error); 351 vp = lvp; 352 goto unionread; 353 } 354 } 355 } 356 #endif /* UNION */ 357 358 if (count == auio.uio_resid && (vp->v_flag & VROOT) && 359 (vp->v_mount->mnt_flag & MNT_UNION)) { 360 struct vnode *tvp = vp; 361 vp = vp->v_mount->mnt_vnodecovered; 362 VREF(vp); 363 fp->f_data = (caddr_t) vp; 364 fp->f_offset = 0; 365 vrele(tvp); 366 goto unionread; 367 } 368 *done = count - auio.uio_resid; 369 return error; 370 } 371 372 /* 373 * File table vnode read routine. 374 */ 375 int 376 vn_read(fp, offset, uio, cred, flags) 377 struct file *fp; 378 off_t *offset; 379 struct uio *uio; 380 struct ucred *cred; 381 int flags; 382 { 383 struct vnode *vp = (struct vnode *)fp->f_data; 384 int count, error, ioflag = 0; 385 386 VOP_LEASE(vp, uio->uio_procp, cred, LEASE_READ); 387 if (fp->f_flag & FNONBLOCK) 388 ioflag |= IO_NDELAY; 389 if ((fp->f_flag & (FFSYNC | FRSYNC)) == (FFSYNC | FRSYNC)) 390 ioflag |= IO_SYNC; 391 if (fp->f_flag & FALTIO) 392 ioflag |= IO_ALTSEMANTICS; 393 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 394 uio->uio_offset = *offset; 395 count = uio->uio_resid; 396 error = VOP_READ(vp, uio, ioflag, cred); 397 if (flags & FOF_UPDATE_OFFSET) 398 *offset += count - uio->uio_resid; 399 VOP_UNLOCK(vp, 0); 400 return (error); 401 } 402 403 /* 404 * File table vnode write routine. 405 */ 406 int 407 vn_write(fp, offset, uio, cred, flags) 408 struct file *fp; 409 off_t *offset; 410 struct uio *uio; 411 struct ucred *cred; 412 int flags; 413 { 414 struct vnode *vp = (struct vnode *)fp->f_data; 415 int count, error, ioflag = IO_UNIT; 416 417 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 418 ioflag |= IO_APPEND; 419 if (fp->f_flag & FNONBLOCK) 420 ioflag |= IO_NDELAY; 421 if (fp->f_flag & FFSYNC || 422 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS))) 423 ioflag |= IO_SYNC; 424 else if (fp->f_flag & FDSYNC) 425 ioflag |= IO_DSYNC; 426 if (fp->f_flag & FALTIO) 427 ioflag |= IO_ALTSEMANTICS; 428 VOP_LEASE(vp, uio->uio_procp, cred, LEASE_WRITE); 429 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 430 uio->uio_offset = *offset; 431 count = uio->uio_resid; 432 error = VOP_WRITE(vp, uio, ioflag, cred); 433 if (flags & FOF_UPDATE_OFFSET) { 434 if (ioflag & IO_APPEND) 435 *offset = uio->uio_offset; 436 else 437 *offset += count - uio->uio_resid; 438 } 439 VOP_UNLOCK(vp, 0); 440 return (error); 441 } 442 443 /* 444 * File table vnode stat routine. 445 */ 446 static int 447 vn_statfile(fp, sb, p) 448 struct file *fp; 449 struct stat *sb; 450 struct proc *p; 451 { 452 struct vnode *vp = (struct vnode *)fp->f_data; 453 454 return vn_stat(vp, sb, p); 455 } 456 457 int 458 vn_stat(fdata, sb, p) 459 void *fdata; 460 struct stat *sb; 461 struct proc *p; 462 { 463 struct vnode *vp = fdata; 464 struct vattr va; 465 int error; 466 mode_t mode; 467 468 error = VOP_GETATTR(vp, &va, p->p_ucred, p); 469 if (error) 470 return (error); 471 /* 472 * Copy from vattr table 473 */ 474 sb->st_dev = va.va_fsid; 475 sb->st_ino = va.va_fileid; 476 mode = va.va_mode; 477 switch (vp->v_type) { 478 case VREG: 479 mode |= S_IFREG; 480 break; 481 case VDIR: 482 mode |= S_IFDIR; 483 break; 484 case VBLK: 485 mode |= S_IFBLK; 486 break; 487 case VCHR: 488 mode |= S_IFCHR; 489 break; 490 case VLNK: 491 mode |= S_IFLNK; 492 break; 493 case VSOCK: 494 mode |= S_IFSOCK; 495 break; 496 case VFIFO: 497 mode |= S_IFIFO; 498 break; 499 default: 500 return (EBADF); 501 }; 502 sb->st_mode = mode; 503 sb->st_nlink = va.va_nlink; 504 sb->st_uid = va.va_uid; 505 sb->st_gid = va.va_gid; 506 sb->st_rdev = va.va_rdev; 507 sb->st_size = va.va_size; 508 sb->st_atimespec = va.va_atime; 509 sb->st_mtimespec = va.va_mtime; 510 sb->st_ctimespec = va.va_ctime; 511 sb->st_blksize = va.va_blocksize; 512 sb->st_flags = va.va_flags; 513 sb->st_gen = 0; 514 sb->st_blocks = va.va_bytes / S_BLKSIZE; 515 return (0); 516 } 517 518 /* 519 * File table vnode fcntl routine. 520 */ 521 int 522 vn_fcntl(fp, com, data, p) 523 struct file *fp; 524 u_int com; 525 caddr_t data; 526 struct proc *p; 527 { 528 struct vnode *vp = ((struct vnode *)fp->f_data); 529 int error; 530 531 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 532 error = VOP_FCNTL(vp, com, data, fp->f_flag, p->p_ucred, p); 533 VOP_UNLOCK(vp, 0); 534 return (error); 535 } 536 537 /* 538 * File table vnode ioctl routine. 539 */ 540 int 541 vn_ioctl(fp, com, data, p) 542 struct file *fp; 543 u_long com; 544 caddr_t data; 545 struct proc *p; 546 { 547 struct vnode *vp = ((struct vnode *)fp->f_data); 548 struct vattr vattr; 549 int error; 550 551 switch (vp->v_type) { 552 553 case VREG: 554 case VDIR: 555 if (com == FIONREAD) { 556 error = VOP_GETATTR(vp, &vattr, p->p_ucred, p); 557 if (error) 558 return (error); 559 *(int *)data = vattr.va_size - fp->f_offset; 560 return (0); 561 } 562 if (com == FIONBIO || com == FIOASYNC) /* XXX */ 563 return (0); /* XXX */ 564 /* fall into ... */ 565 566 default: 567 return (ENOTTY); 568 569 case VFIFO: 570 case VCHR: 571 case VBLK: 572 error = VOP_IOCTL(vp, com, data, fp->f_flag, p->p_ucred, p); 573 if (error == 0 && com == TIOCSCTTY) { 574 if (p->p_session->s_ttyvp) 575 vrele(p->p_session->s_ttyvp); 576 p->p_session->s_ttyvp = vp; 577 VREF(vp); 578 } 579 return (error); 580 } 581 } 582 583 /* 584 * File table vnode poll routine. 585 */ 586 int 587 vn_poll(fp, events, p) 588 struct file *fp; 589 int events; 590 struct proc *p; 591 { 592 593 return (VOP_POLL(((struct vnode *)fp->f_data), events, p)); 594 } 595 596 /* 597 * Check that the vnode is still valid, and if so 598 * acquire requested lock. 599 */ 600 int 601 vn_lock(vp, flags) 602 struct vnode *vp; 603 int flags; 604 { 605 int error; 606 607 do { 608 if ((flags & LK_INTERLOCK) == 0) 609 simple_lock(&vp->v_interlock); 610 if (vp->v_flag & VXLOCK) { 611 vp->v_flag |= VXWANT; 612 ltsleep((caddr_t)vp, PINOD | PNORELOCK, 613 "vn_lock", 0, &vp->v_interlock); 614 error = ENOENT; 615 } else { 616 error = VOP_LOCK(vp, flags | LK_INTERLOCK); 617 if (error == 0 || error == EDEADLK) 618 return (error); 619 } 620 flags &= ~LK_INTERLOCK; 621 } while (flags & LK_RETRY); 622 return (error); 623 } 624 625 /* 626 * File table vnode close routine. 627 */ 628 int 629 vn_closefile(fp, p) 630 struct file *fp; 631 struct proc *p; 632 { 633 634 return (vn_close(((struct vnode *)fp->f_data), fp->f_flag, 635 fp->f_cred, p)); 636 } 637 638 /* 639 * Enable LK_CANRECURSE on lock. Return prior status. 640 */ 641 u_int 642 vn_setrecurse(vp) 643 struct vnode *vp; 644 { 645 struct lock *lkp = &vp->v_lock; 646 u_int retval = lkp->lk_flags & LK_CANRECURSE; 647 648 lkp->lk_flags |= LK_CANRECURSE; 649 return retval; 650 } 651 652 /* 653 * Called when done with locksetrecurse. 654 */ 655 void 656 vn_restorerecurse(vp, flags) 657 struct vnode *vp; 658 u_int flags; 659 { 660 struct lock *lkp = &vp->v_lock; 661 662 lkp->lk_flags &= ~LK_CANRECURSE; 663 lkp->lk_flags |= flags; 664 } 665
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