vfs_vnops.c revision 1.42
1 /* $NetBSD: vfs_vnops.c,v 1.42 2000/04/11 04:37:51 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 <vm/vm.h> 60 61 #include <uvm/uvm_extern.h> 62 63 #ifdef UNION 64 #include <miscfs/union/union.h> 65 #endif 66 67 struct fileops vnops = 68 { vn_read, vn_write, vn_ioctl, vn_fcntl, vn_poll, vn_closefile }; 69 70 /* 71 * Common code for vnode open operations. 72 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine. 73 */ 74 int 75 vn_open(ndp, fmode, cmode) 76 struct nameidata *ndp; 77 int fmode, cmode; 78 { 79 struct vnode *vp; 80 struct proc *p = ndp->ni_cnd.cn_proc; 81 struct ucred *cred = p->p_ucred; 82 struct vattr va; 83 int error; 84 85 if (fmode & O_CREAT) { 86 ndp->ni_cnd.cn_nameiop = CREATE; 87 ndp->ni_cnd.cn_flags = LOCKPARENT | LOCKLEAF; 88 if ((fmode & O_EXCL) == 0 && 89 ((fmode & FNOSYMLINK) == 0)) 90 ndp->ni_cnd.cn_flags |= FOLLOW; 91 if ((error = namei(ndp)) != 0) 92 return (error); 93 if (ndp->ni_vp == NULL) { 94 VATTR_NULL(&va); 95 va.va_type = VREG; 96 va.va_mode = cmode; 97 if (fmode & O_EXCL) 98 va.va_vaflags |= VA_EXCLUSIVE; 99 VOP_LEASE(ndp->ni_dvp, p, cred, LEASE_WRITE); 100 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp, 101 &ndp->ni_cnd, &va); 102 if (error) 103 return (error); 104 fmode &= ~O_TRUNC; 105 vp = ndp->ni_vp; 106 } else { 107 VOP_ABORTOP(ndp->ni_dvp, &ndp->ni_cnd); 108 if (ndp->ni_dvp == ndp->ni_vp) 109 vrele(ndp->ni_dvp); 110 else 111 vput(ndp->ni_dvp); 112 ndp->ni_dvp = NULL; 113 vp = ndp->ni_vp; 114 if (fmode & O_EXCL) { 115 error = EEXIST; 116 goto bad; 117 } 118 if (ndp->ni_vp->v_type == VLNK) { 119 error = EFTYPE; 120 goto bad; 121 } 122 fmode &= ~O_CREAT; 123 } 124 } else { 125 ndp->ni_cnd.cn_nameiop = LOOKUP; 126 ndp->ni_cnd.cn_flags = FOLLOW | LOCKLEAF; 127 if ((error = namei(ndp)) != 0) 128 return (error); 129 vp = ndp->ni_vp; 130 } 131 if (vp->v_type == VSOCK) { 132 error = EOPNOTSUPP; 133 goto bad; 134 } 135 if ((fmode & O_CREAT) == 0) { 136 if (fmode & FREAD) { 137 if ((error = VOP_ACCESS(vp, VREAD, cred, p)) != 0) 138 goto bad; 139 } 140 if (fmode & (FWRITE | O_TRUNC)) { 141 if (vp->v_type == VDIR) { 142 error = EISDIR; 143 goto bad; 144 } 145 if ((error = vn_writechk(vp)) != 0 || 146 (error = VOP_ACCESS(vp, VWRITE, cred, p)) != 0) 147 goto bad; 148 } 149 } 150 if (fmode & O_TRUNC) { 151 VOP_UNLOCK(vp, 0); /* XXX */ 152 VOP_LEASE(vp, p, cred, LEASE_WRITE); 153 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); /* XXX */ 154 VATTR_NULL(&va); 155 va.va_size = 0; 156 if ((error = VOP_SETATTR(vp, &va, cred, p)) != 0) 157 goto bad; 158 } 159 if ((error = VOP_OPEN(vp, fmode, cred, p)) != 0) 160 goto bad; 161 if (fmode & FWRITE) 162 vp->v_writecount++; 163 return (0); 164 bad: 165 vput(vp); 166 return (error); 167 } 168 169 /* 170 * Check for write permissions on the specified vnode. 171 * Prototype text segments cannot be written. 172 */ 173 int 174 vn_writechk(vp) 175 struct vnode *vp; 176 { 177 178 /* 179 * If there's shared text associated with 180 * the vnode, try to free it up once. If 181 * we fail, we can't allow writing. 182 */ 183 if ((vp->v_flag & VTEXT) && !uvm_vnp_uncache(vp)) 184 return (ETXTBSY); 185 return (0); 186 } 187 188 /* 189 * Mark a vnode as being the text image of a running process. 190 */ 191 void 192 vn_marktext(vp) 193 struct vnode *vp; 194 { 195 vp->v_flag |= VTEXT; 196 } 197 198 /* 199 * Vnode close call 200 * 201 * Note: takes an unlocked vnode, while VOP_CLOSE takes a locked node. 202 */ 203 int 204 vn_close(vp, flags, cred, p) 205 struct vnode *vp; 206 int flags; 207 struct ucred *cred; 208 struct proc *p; 209 { 210 int error; 211 212 if (flags & FWRITE) 213 vp->v_writecount--; 214 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 215 error = VOP_CLOSE(vp, flags, cred, p); 216 vput(vp); 217 return (error); 218 } 219 220 /* 221 * Package up an I/O request on a vnode into a uio and do it. 222 */ 223 int 224 vn_rdwr(rw, vp, base, len, offset, segflg, ioflg, cred, aresid, p) 225 enum uio_rw rw; 226 struct vnode *vp; 227 caddr_t base; 228 int len; 229 off_t offset; 230 enum uio_seg segflg; 231 int ioflg; 232 struct ucred *cred; 233 size_t *aresid; 234 struct proc *p; 235 { 236 struct uio auio; 237 struct iovec aiov; 238 int error; 239 240 if ((ioflg & IO_NODELOCKED) == 0) 241 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 242 auio.uio_iov = &aiov; 243 auio.uio_iovcnt = 1; 244 aiov.iov_base = base; 245 aiov.iov_len = len; 246 auio.uio_resid = len; 247 auio.uio_offset = offset; 248 auio.uio_segflg = segflg; 249 auio.uio_rw = rw; 250 auio.uio_procp = p; 251 if (rw == UIO_READ) { 252 error = VOP_READ(vp, &auio, ioflg, cred); 253 } else { 254 error = VOP_WRITE(vp, &auio, ioflg, cred); 255 } 256 if (aresid) 257 *aresid = auio.uio_resid; 258 else 259 if (auio.uio_resid && error == 0) 260 error = EIO; 261 if ((ioflg & IO_NODELOCKED) == 0) 262 VOP_UNLOCK(vp, 0); 263 return (error); 264 } 265 266 int 267 vn_readdir(fp, buf, segflg, count, done, p, cookies, ncookies) 268 struct file *fp; 269 char *buf; 270 int segflg, *done, *ncookies; 271 u_int count; 272 struct proc *p; 273 off_t **cookies; 274 { 275 struct vnode *vp = (struct vnode *)fp->f_data; 276 struct iovec aiov; 277 struct uio auio; 278 int error, eofflag; 279 280 unionread: 281 if (vp->v_type != VDIR) 282 return (EINVAL); 283 aiov.iov_base = buf; 284 aiov.iov_len = count; 285 auio.uio_iov = &aiov; 286 auio.uio_iovcnt = 1; 287 auio.uio_rw = UIO_READ; 288 auio.uio_segflg = segflg; 289 auio.uio_procp = p; 290 auio.uio_resid = count; 291 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 292 auio.uio_offset = fp->f_offset; 293 error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, cookies, 294 ncookies); 295 fp->f_offset = auio.uio_offset; 296 VOP_UNLOCK(vp, 0); 297 if (error) 298 return (error); 299 300 #ifdef UNION 301 { 302 extern struct vnode *union_dircache __P((struct vnode *)); 303 304 if (count == auio.uio_resid && (vp->v_op == union_vnodeop_p)) { 305 struct vnode *lvp; 306 307 lvp = union_dircache(vp); 308 if (lvp != NULLVP) { 309 struct vattr va; 310 311 /* 312 * If the directory is opaque, 313 * then don't show lower entries 314 */ 315 error = VOP_GETATTR(vp, &va, fp->f_cred, p); 316 if (va.va_flags & OPAQUE) { 317 vput(lvp); 318 lvp = NULL; 319 } 320 } 321 322 if (lvp != NULLVP) { 323 error = VOP_OPEN(lvp, FREAD, fp->f_cred, p); 324 if (error) { 325 vput(lvp); 326 return (error); 327 } 328 VOP_UNLOCK(lvp, 0); 329 fp->f_data = (caddr_t) lvp; 330 fp->f_offset = 0; 331 error = vn_close(vp, FREAD, fp->f_cred, p); 332 if (error) 333 return (error); 334 vp = lvp; 335 goto unionread; 336 } 337 } 338 } 339 #endif /* UNION */ 340 341 if (count == auio.uio_resid && (vp->v_flag & VROOT) && 342 (vp->v_mount->mnt_flag & MNT_UNION)) { 343 struct vnode *tvp = vp; 344 vp = vp->v_mount->mnt_vnodecovered; 345 VREF(vp); 346 fp->f_data = (caddr_t) vp; 347 fp->f_offset = 0; 348 vrele(tvp); 349 goto unionread; 350 } 351 *done = count - auio.uio_resid; 352 return error; 353 } 354 355 /* 356 * File table vnode read routine. 357 */ 358 int 359 vn_read(fp, offset, uio, cred, flags) 360 struct file *fp; 361 off_t *offset; 362 struct uio *uio; 363 struct ucred *cred; 364 int flags; 365 { 366 struct vnode *vp = (struct vnode *)fp->f_data; 367 int count, error, ioflag = 0; 368 369 VOP_LEASE(vp, uio->uio_procp, cred, LEASE_READ); 370 if (fp->f_flag & FNONBLOCK) 371 ioflag |= IO_NDELAY; 372 if ((fp->f_flag & (FFSYNC | FRSYNC)) == (FFSYNC | FRSYNC)) 373 ioflag |= IO_SYNC; 374 if (fp->f_flag & FALTIO) 375 ioflag |= IO_ALTSEMANTICS; 376 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 377 uio->uio_offset = *offset; 378 count = uio->uio_resid; 379 error = VOP_READ(vp, uio, ioflag, cred); 380 if (flags & FOF_UPDATE_OFFSET) 381 *offset += count - uio->uio_resid; 382 VOP_UNLOCK(vp, 0); 383 return (error); 384 } 385 386 /* 387 * File table vnode write routine. 388 */ 389 int 390 vn_write(fp, offset, uio, cred, flags) 391 struct file *fp; 392 off_t *offset; 393 struct uio *uio; 394 struct ucred *cred; 395 int flags; 396 { 397 struct vnode *vp = (struct vnode *)fp->f_data; 398 int count, error, ioflag = IO_UNIT; 399 400 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 401 ioflag |= IO_APPEND; 402 if (fp->f_flag & FNONBLOCK) 403 ioflag |= IO_NDELAY; 404 if (fp->f_flag & FFSYNC || 405 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS))) 406 ioflag |= IO_SYNC; 407 else if (fp->f_flag & FDSYNC) 408 ioflag |= IO_DSYNC; 409 if (fp->f_flag & FALTIO) 410 ioflag |= IO_ALTSEMANTICS; 411 VOP_LEASE(vp, uio->uio_procp, cred, LEASE_WRITE); 412 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 413 uio->uio_offset = *offset; 414 count = uio->uio_resid; 415 error = VOP_WRITE(vp, uio, ioflag, cred); 416 if (flags & FOF_UPDATE_OFFSET) { 417 if (ioflag & IO_APPEND) 418 *offset = uio->uio_offset; 419 else 420 *offset += count - uio->uio_resid; 421 } 422 VOP_UNLOCK(vp, 0); 423 return (error); 424 } 425 426 /* 427 * File table vnode stat routine. 428 */ 429 int 430 vn_stat(vp, sb, p) 431 struct vnode *vp; 432 struct stat *sb; 433 struct proc *p; 434 { 435 struct vattr va; 436 int error; 437 mode_t mode; 438 439 error = VOP_GETATTR(vp, &va, p->p_ucred, p); 440 if (error) 441 return (error); 442 /* 443 * Copy from vattr table 444 */ 445 sb->st_dev = va.va_fsid; 446 sb->st_ino = va.va_fileid; 447 mode = va.va_mode; 448 switch (vp->v_type) { 449 case VREG: 450 mode |= S_IFREG; 451 break; 452 case VDIR: 453 mode |= S_IFDIR; 454 break; 455 case VBLK: 456 mode |= S_IFBLK; 457 break; 458 case VCHR: 459 mode |= S_IFCHR; 460 break; 461 case VLNK: 462 mode |= S_IFLNK; 463 break; 464 case VSOCK: 465 mode |= S_IFSOCK; 466 break; 467 case VFIFO: 468 mode |= S_IFIFO; 469 break; 470 default: 471 return (EBADF); 472 }; 473 sb->st_mode = mode; 474 sb->st_nlink = va.va_nlink; 475 sb->st_uid = va.va_uid; 476 sb->st_gid = va.va_gid; 477 sb->st_rdev = va.va_rdev; 478 sb->st_size = va.va_size; 479 sb->st_atimespec = va.va_atime; 480 sb->st_mtimespec = va.va_mtime; 481 sb->st_ctimespec = va.va_ctime; 482 sb->st_blksize = va.va_blocksize; 483 sb->st_flags = va.va_flags; 484 sb->st_gen = 0; 485 sb->st_blocks = va.va_bytes / S_BLKSIZE; 486 return (0); 487 } 488 489 /* 490 * File table vnode fcntl routine. 491 */ 492 int 493 vn_fcntl(fp, com, data, p) 494 struct file *fp; 495 u_int com; 496 caddr_t data; 497 struct proc *p; 498 { 499 struct vnode *vp = ((struct vnode *)fp->f_data); 500 int error; 501 502 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 503 error = VOP_FCNTL(vp, com, data, fp->f_flag, p->p_ucred, p); 504 VOP_UNLOCK(vp, 0); 505 return (error); 506 } 507 508 /* 509 * File table vnode ioctl routine. 510 */ 511 int 512 vn_ioctl(fp, com, data, p) 513 struct file *fp; 514 u_long com; 515 caddr_t data; 516 struct proc *p; 517 { 518 struct vnode *vp = ((struct vnode *)fp->f_data); 519 struct vattr vattr; 520 int error; 521 522 switch (vp->v_type) { 523 524 case VREG: 525 case VDIR: 526 if (com == FIONREAD) { 527 error = VOP_GETATTR(vp, &vattr, p->p_ucred, p); 528 if (error) 529 return (error); 530 *(int *)data = vattr.va_size - fp->f_offset; 531 return (0); 532 } 533 if (com == FIONBIO || com == FIOASYNC) /* XXX */ 534 return (0); /* XXX */ 535 /* fall into ... */ 536 537 default: 538 return (ENOTTY); 539 540 case VFIFO: 541 case VCHR: 542 case VBLK: 543 error = VOP_IOCTL(vp, com, data, fp->f_flag, p->p_ucred, p); 544 if (error == 0 && com == TIOCSCTTY) { 545 if (p->p_session->s_ttyvp) 546 vrele(p->p_session->s_ttyvp); 547 p->p_session->s_ttyvp = vp; 548 VREF(vp); 549 } 550 return (error); 551 } 552 } 553 554 /* 555 * File table vnode poll routine. 556 */ 557 int 558 vn_poll(fp, events, p) 559 struct file *fp; 560 int events; 561 struct proc *p; 562 { 563 564 return (VOP_POLL(((struct vnode *)fp->f_data), events, p)); 565 } 566 567 /* 568 * Check that the vnode is still valid, and if so 569 * acquire requested lock. 570 */ 571 int 572 vn_lock(vp, flags) 573 struct vnode *vp; 574 int flags; 575 { 576 int error; 577 578 do { 579 if ((flags & LK_INTERLOCK) == 0) 580 simple_lock(&vp->v_interlock); 581 if (vp->v_flag & VXLOCK) { 582 vp->v_flag |= VXWANT; 583 simple_unlock(&vp->v_interlock); 584 tsleep((caddr_t)vp, PINOD, "vn_lock", 0); 585 error = ENOENT; 586 } else { 587 error = VOP_LOCK(vp, flags | LK_INTERLOCK); 588 if (error == 0 || error == EDEADLK) 589 return (error); 590 } 591 flags &= ~LK_INTERLOCK; 592 } while (flags & LK_RETRY); 593 return (error); 594 } 595 596 /* 597 * File table vnode close routine. 598 */ 599 int 600 vn_closefile(fp, p) 601 struct file *fp; 602 struct proc *p; 603 { 604 605 return (vn_close(((struct vnode *)fp->f_data), fp->f_flag, 606 fp->f_cred, p)); 607 } 608 609 /* 610 * Enable LK_CANRECURSE on lock. Return prior status. 611 */ 612 u_int 613 vn_setrecurse(vp) 614 struct vnode *vp; 615 { 616 struct lock *lkp = &vp->v_lock; 617 u_int retval = lkp->lk_flags & LK_CANRECURSE; 618 619 lkp->lk_flags |= LK_CANRECURSE; 620 return retval; 621 } 622 623 /* 624 * Called when done with locksetrecurse. 625 */ 626 void 627 vn_restorerecurse(vp, flags) 628 struct vnode *vp; 629 u_int flags; 630 { 631 struct lock *lkp = &vp->v_lock; 632 633 lkp->lk_flags &= ~LK_CANRECURSE; 634 lkp->lk_flags |= flags; 635 } 636
Indexes created Mon Sep 22 05:09:51 GMT 2025