vfs_vnops.c revision 1.46
1 /* $NetBSD: vfs_vnops.c,v 1.46 2001/03/09 01:02:11 chs 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 struct fileops vnops = 66 { vn_read, vn_write, vn_ioctl, vn_fcntl, vn_poll, vn_closefile }; 67 68 /* 69 * Common code for vnode open operations. 70 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine. 71 */ 72 int 73 vn_open(ndp, fmode, cmode) 74 struct nameidata *ndp; 75 int fmode, cmode; 76 { 77 struct vnode *vp; 78 struct proc *p = ndp->ni_cnd.cn_proc; 79 struct ucred *cred = p->p_ucred; 80 struct vattr va; 81 int error; 82 83 if (fmode & O_CREAT) { 84 ndp->ni_cnd.cn_nameiop = CREATE; 85 ndp->ni_cnd.cn_flags = LOCKPARENT | LOCKLEAF; 86 if ((fmode & O_EXCL) == 0 && 87 ((fmode & FNOSYMLINK) == 0)) 88 ndp->ni_cnd.cn_flags |= FOLLOW; 89 if ((error = namei(ndp)) != 0) 90 return (error); 91 if (ndp->ni_vp == NULL) { 92 VATTR_NULL(&va); 93 va.va_type = VREG; 94 va.va_mode = cmode; 95 if (fmode & O_EXCL) 96 va.va_vaflags |= VA_EXCLUSIVE; 97 VOP_LEASE(ndp->ni_dvp, p, cred, LEASE_WRITE); 98 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp, 99 &ndp->ni_cnd, &va); 100 if (error) 101 return (error); 102 fmode &= ~O_TRUNC; 103 vp = ndp->ni_vp; 104 } else { 105 VOP_ABORTOP(ndp->ni_dvp, &ndp->ni_cnd); 106 if (ndp->ni_dvp == ndp->ni_vp) 107 vrele(ndp->ni_dvp); 108 else 109 vput(ndp->ni_dvp); 110 ndp->ni_dvp = NULL; 111 vp = ndp->ni_vp; 112 if (fmode & O_EXCL) { 113 error = EEXIST; 114 goto bad; 115 } 116 if (ndp->ni_vp->v_type == VLNK) { 117 error = EFTYPE; 118 goto bad; 119 } 120 fmode &= ~O_CREAT; 121 } 122 } else { 123 ndp->ni_cnd.cn_nameiop = LOOKUP; 124 ndp->ni_cnd.cn_flags = FOLLOW | LOCKLEAF; 125 if ((error = namei(ndp)) != 0) 126 return (error); 127 vp = ndp->ni_vp; 128 } 129 if (vp->v_type == VSOCK) { 130 error = EOPNOTSUPP; 131 goto bad; 132 } 133 if ((fmode & O_CREAT) == 0) { 134 if (fmode & FREAD) { 135 if ((error = VOP_ACCESS(vp, VREAD, cred, p)) != 0) 136 goto bad; 137 } 138 if (fmode & (FWRITE | O_TRUNC)) { 139 if (vp->v_type == VDIR) { 140 error = EISDIR; 141 goto bad; 142 } 143 if ((error = vn_writechk(vp)) != 0 || 144 (error = VOP_ACCESS(vp, VWRITE, cred, p)) != 0) 145 goto bad; 146 } 147 } 148 if (fmode & O_TRUNC) { 149 VOP_UNLOCK(vp, 0); /* XXX */ 150 VOP_LEASE(vp, p, cred, LEASE_WRITE); 151 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); /* XXX */ 152 VATTR_NULL(&va); 153 va.va_size = 0; 154 if ((error = VOP_SETATTR(vp, &va, cred, p)) != 0) 155 goto bad; 156 } 157 if ((error = VOP_OPEN(vp, fmode, cred, p)) != 0) 158 goto bad; 159 if (vp->v_type == VREG && 160 uvn_attach(vp, fmode & FWRITE ? VM_PROT_WRITE : 0) == NULL) { 161 error = EIO; 162 goto bad; 163 } 164 if (fmode & FWRITE) 165 vp->v_writecount++; 166 167 return (0); 168 bad: 169 vput(vp); 170 return (error); 171 } 172 173 /* 174 * Check for write permissions on the specified vnode. 175 * Prototype text segments cannot be written. 176 */ 177 int 178 vn_writechk(vp) 179 struct vnode *vp; 180 { 181 182 /* 183 * If the vnode is in use as a process's text, 184 * we can't allow writing. 185 */ 186 if (vp->v_flag & VTEXT) 187 return (ETXTBSY); 188 return (0); 189 } 190 191 /* 192 * Mark a vnode as being the text image of a running process. 193 */ 194 void 195 vn_marktext(vp) 196 struct vnode *vp; 197 { 198 if ((vp->v_flag & VTEXT) == 0) { 199 uvmexp.vnodepages -= vp->v_uvm.u_obj.uo_npages; 200 uvmexp.vtextpages += vp->v_uvm.u_obj.uo_npages; 201 } 202 vp->v_flag |= VTEXT; 203 } 204 205 /* 206 * Vnode close call 207 * 208 * Note: takes an unlocked vnode, while VOP_CLOSE takes a locked node. 209 */ 210 int 211 vn_close(vp, flags, cred, p) 212 struct vnode *vp; 213 int flags; 214 struct ucred *cred; 215 struct proc *p; 216 { 217 int error; 218 219 if (flags & FWRITE) 220 vp->v_writecount--; 221 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 222 error = VOP_CLOSE(vp, flags, cred, p); 223 vput(vp); 224 return (error); 225 } 226 227 /* 228 * Package up an I/O request on a vnode into a uio and do it. 229 */ 230 int 231 vn_rdwr(rw, vp, base, len, offset, segflg, ioflg, cred, aresid, p) 232 enum uio_rw rw; 233 struct vnode *vp; 234 caddr_t base; 235 int len; 236 off_t offset; 237 enum uio_seg segflg; 238 int ioflg; 239 struct ucred *cred; 240 size_t *aresid; 241 struct proc *p; 242 { 243 struct uio auio; 244 struct iovec aiov; 245 int error; 246 247 if ((ioflg & IO_NODELOCKED) == 0) 248 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 249 auio.uio_iov = &aiov; 250 auio.uio_iovcnt = 1; 251 aiov.iov_base = base; 252 aiov.iov_len = len; 253 auio.uio_resid = len; 254 auio.uio_offset = offset; 255 auio.uio_segflg = segflg; 256 auio.uio_rw = rw; 257 auio.uio_procp = p; 258 if (rw == UIO_READ) { 259 error = VOP_READ(vp, &auio, ioflg, cred); 260 } else { 261 error = VOP_WRITE(vp, &auio, ioflg, cred); 262 } 263 if (aresid) 264 *aresid = auio.uio_resid; 265 else 266 if (auio.uio_resid && error == 0) 267 error = EIO; 268 if ((ioflg & IO_NODELOCKED) == 0) 269 VOP_UNLOCK(vp, 0); 270 return (error); 271 } 272 273 int 274 vn_readdir(fp, buf, segflg, count, done, p, cookies, ncookies) 275 struct file *fp; 276 char *buf; 277 int segflg, *done, *ncookies; 278 u_int count; 279 struct proc *p; 280 off_t **cookies; 281 { 282 struct vnode *vp = (struct vnode *)fp->f_data; 283 struct iovec aiov; 284 struct uio auio; 285 int error, eofflag; 286 287 unionread: 288 if (vp->v_type != VDIR) 289 return (EINVAL); 290 aiov.iov_base = buf; 291 aiov.iov_len = count; 292 auio.uio_iov = &aiov; 293 auio.uio_iovcnt = 1; 294 auio.uio_rw = UIO_READ; 295 auio.uio_segflg = segflg; 296 auio.uio_procp = p; 297 auio.uio_resid = count; 298 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 299 auio.uio_offset = fp->f_offset; 300 error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, cookies, 301 ncookies); 302 fp->f_offset = auio.uio_offset; 303 VOP_UNLOCK(vp, 0); 304 if (error) 305 return (error); 306 307 #ifdef UNION 308 { 309 extern struct vnode *union_dircache __P((struct vnode *)); 310 311 if (count == auio.uio_resid && (vp->v_op == union_vnodeop_p)) { 312 struct vnode *lvp; 313 314 lvp = union_dircache(vp); 315 if (lvp != NULLVP) { 316 struct vattr va; 317 318 /* 319 * If the directory is opaque, 320 * then don't show lower entries 321 */ 322 error = VOP_GETATTR(vp, &va, fp->f_cred, p); 323 if (va.va_flags & OPAQUE) { 324 vput(lvp); 325 lvp = NULL; 326 } 327 } 328 329 if (lvp != NULLVP) { 330 error = VOP_OPEN(lvp, FREAD, fp->f_cred, p); 331 if (error) { 332 vput(lvp); 333 return (error); 334 } 335 VOP_UNLOCK(lvp, 0); 336 fp->f_data = (caddr_t) lvp; 337 fp->f_offset = 0; 338 error = vn_close(vp, FREAD, fp->f_cred, p); 339 if (error) 340 return (error); 341 vp = lvp; 342 goto unionread; 343 } 344 } 345 } 346 #endif /* UNION */ 347 348 if (count == auio.uio_resid && (vp->v_flag & VROOT) && 349 (vp->v_mount->mnt_flag & MNT_UNION)) { 350 struct vnode *tvp = vp; 351 vp = vp->v_mount->mnt_vnodecovered; 352 VREF(vp); 353 fp->f_data = (caddr_t) vp; 354 fp->f_offset = 0; 355 vrele(tvp); 356 goto unionread; 357 } 358 *done = count - auio.uio_resid; 359 return error; 360 } 361 362 /* 363 * File table vnode read routine. 364 */ 365 int 366 vn_read(fp, offset, uio, cred, flags) 367 struct file *fp; 368 off_t *offset; 369 struct uio *uio; 370 struct ucred *cred; 371 int flags; 372 { 373 struct vnode *vp = (struct vnode *)fp->f_data; 374 int count, error, ioflag = 0; 375 376 VOP_LEASE(vp, uio->uio_procp, cred, LEASE_READ); 377 if (fp->f_flag & FNONBLOCK) 378 ioflag |= IO_NDELAY; 379 if ((fp->f_flag & (FFSYNC | FRSYNC)) == (FFSYNC | FRSYNC)) 380 ioflag |= IO_SYNC; 381 if (fp->f_flag & FALTIO) 382 ioflag |= IO_ALTSEMANTICS; 383 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 384 uio->uio_offset = *offset; 385 count = uio->uio_resid; 386 error = VOP_READ(vp, uio, ioflag, cred); 387 if (flags & FOF_UPDATE_OFFSET) 388 *offset += count - uio->uio_resid; 389 VOP_UNLOCK(vp, 0); 390 return (error); 391 } 392 393 /* 394 * File table vnode write routine. 395 */ 396 int 397 vn_write(fp, offset, uio, cred, flags) 398 struct file *fp; 399 off_t *offset; 400 struct uio *uio; 401 struct ucred *cred; 402 int flags; 403 { 404 struct vnode *vp = (struct vnode *)fp->f_data; 405 int count, error, ioflag = IO_UNIT; 406 407 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 408 ioflag |= IO_APPEND; 409 if (fp->f_flag & FNONBLOCK) 410 ioflag |= IO_NDELAY; 411 if (fp->f_flag & FFSYNC || 412 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS))) 413 ioflag |= IO_SYNC; 414 else if (fp->f_flag & FDSYNC) 415 ioflag |= IO_DSYNC; 416 if (fp->f_flag & FALTIO) 417 ioflag |= IO_ALTSEMANTICS; 418 VOP_LEASE(vp, uio->uio_procp, cred, LEASE_WRITE); 419 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 420 uio->uio_offset = *offset; 421 count = uio->uio_resid; 422 error = VOP_WRITE(vp, uio, ioflag, cred); 423 if (flags & FOF_UPDATE_OFFSET) { 424 if (ioflag & IO_APPEND) 425 *offset = uio->uio_offset; 426 else 427 *offset += count - uio->uio_resid; 428 } 429 VOP_UNLOCK(vp, 0); 430 return (error); 431 } 432 433 /* 434 * File table vnode stat routine. 435 */ 436 int 437 vn_stat(vp, sb, p) 438 struct vnode *vp; 439 struct stat *sb; 440 struct proc *p; 441 { 442 struct vattr va; 443 int error; 444 mode_t mode; 445 446 error = VOP_GETATTR(vp, &va, p->p_ucred, p); 447 if (error) 448 return (error); 449 /* 450 * Copy from vattr table 451 */ 452 sb->st_dev = va.va_fsid; 453 sb->st_ino = va.va_fileid; 454 mode = va.va_mode; 455 switch (vp->v_type) { 456 case VREG: 457 mode |= S_IFREG; 458 break; 459 case VDIR: 460 mode |= S_IFDIR; 461 break; 462 case VBLK: 463 mode |= S_IFBLK; 464 break; 465 case VCHR: 466 mode |= S_IFCHR; 467 break; 468 case VLNK: 469 mode |= S_IFLNK; 470 break; 471 case VSOCK: 472 mode |= S_IFSOCK; 473 break; 474 case VFIFO: 475 mode |= S_IFIFO; 476 break; 477 default: 478 return (EBADF); 479 }; 480 sb->st_mode = mode; 481 sb->st_nlink = va.va_nlink; 482 sb->st_uid = va.va_uid; 483 sb->st_gid = va.va_gid; 484 sb->st_rdev = va.va_rdev; 485 sb->st_size = va.va_size; 486 sb->st_atimespec = va.va_atime; 487 sb->st_mtimespec = va.va_mtime; 488 sb->st_ctimespec = va.va_ctime; 489 sb->st_blksize = va.va_blocksize; 490 sb->st_flags = va.va_flags; 491 sb->st_gen = 0; 492 sb->st_blocks = va.va_bytes / S_BLKSIZE; 493 return (0); 494 } 495 496 /* 497 * File table vnode fcntl routine. 498 */ 499 int 500 vn_fcntl(fp, com, data, p) 501 struct file *fp; 502 u_int com; 503 caddr_t data; 504 struct proc *p; 505 { 506 struct vnode *vp = ((struct vnode *)fp->f_data); 507 int error; 508 509 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 510 error = VOP_FCNTL(vp, com, data, fp->f_flag, p->p_ucred, p); 511 VOP_UNLOCK(vp, 0); 512 return (error); 513 } 514 515 /* 516 * File table vnode ioctl routine. 517 */ 518 int 519 vn_ioctl(fp, com, data, p) 520 struct file *fp; 521 u_long com; 522 caddr_t data; 523 struct proc *p; 524 { 525 struct vnode *vp = ((struct vnode *)fp->f_data); 526 struct vattr vattr; 527 int error; 528 529 switch (vp->v_type) { 530 531 case VREG: 532 case VDIR: 533 if (com == FIONREAD) { 534 error = VOP_GETATTR(vp, &vattr, p->p_ucred, p); 535 if (error) 536 return (error); 537 *(int *)data = vattr.va_size - fp->f_offset; 538 return (0); 539 } 540 if (com == FIONBIO || com == FIOASYNC) /* XXX */ 541 return (0); /* XXX */ 542 /* fall into ... */ 543 544 default: 545 return (ENOTTY); 546 547 case VFIFO: 548 case VCHR: 549 case VBLK: 550 error = VOP_IOCTL(vp, com, data, fp->f_flag, p->p_ucred, p); 551 if (error == 0 && com == TIOCSCTTY) { 552 if (p->p_session->s_ttyvp) 553 vrele(p->p_session->s_ttyvp); 554 p->p_session->s_ttyvp = vp; 555 VREF(vp); 556 } 557 return (error); 558 } 559 } 560 561 /* 562 * File table vnode poll routine. 563 */ 564 int 565 vn_poll(fp, events, p) 566 struct file *fp; 567 int events; 568 struct proc *p; 569 { 570 571 return (VOP_POLL(((struct vnode *)fp->f_data), events, p)); 572 } 573 574 /* 575 * Check that the vnode is still valid, and if so 576 * acquire requested lock. 577 */ 578 int 579 vn_lock(vp, flags) 580 struct vnode *vp; 581 int flags; 582 { 583 int error; 584 585 do { 586 if ((flags & LK_INTERLOCK) == 0) 587 simple_lock(&vp->v_interlock); 588 if (vp->v_flag & VXLOCK) { 589 vp->v_flag |= VXWANT; 590 ltsleep((caddr_t)vp, PINOD | PNORELOCK, 591 "vn_lock", 0, &vp->v_interlock); 592 error = ENOENT; 593 } else { 594 error = VOP_LOCK(vp, flags | LK_INTERLOCK); 595 if (error == 0 || error == EDEADLK) 596 return (error); 597 } 598 flags &= ~LK_INTERLOCK; 599 } while (flags & LK_RETRY); 600 return (error); 601 } 602 603 /* 604 * File table vnode close routine. 605 */ 606 int 607 vn_closefile(fp, p) 608 struct file *fp; 609 struct proc *p; 610 { 611 612 return (vn_close(((struct vnode *)fp->f_data), fp->f_flag, 613 fp->f_cred, p)); 614 } 615 616 /* 617 * Enable LK_CANRECURSE on lock. Return prior status. 618 */ 619 u_int 620 vn_setrecurse(vp) 621 struct vnode *vp; 622 { 623 struct lock *lkp = &vp->v_lock; 624 u_int retval = lkp->lk_flags & LK_CANRECURSE; 625 626 lkp->lk_flags |= LK_CANRECURSE; 627 return retval; 628 } 629 630 /* 631 * Called when done with locksetrecurse. 632 */ 633 void 634 vn_restorerecurse(vp, flags) 635 struct vnode *vp; 636 u_int flags; 637 { 638 struct lock *lkp = &vp->v_lock; 639 640 lkp->lk_flags &= ~LK_CANRECURSE; 641 lkp->lk_flags |= flags; 642 } 643
Indexes created Sat Sep 20 22:09:52 GMT 2025