vfs_vnops.c revision 1.43
1 /* $NetBSD: vfs_vnops.c,v 1.43 2000/06/27 17:41:54 mrg 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 (fmode & FWRITE) 160 vp->v_writecount++; 161 return (0); 162 bad: 163 vput(vp); 164 return (error); 165 } 166 167 /* 168 * Check for write permissions on the specified vnode. 169 * Prototype text segments cannot be written. 170 */ 171 int 172 vn_writechk(vp) 173 struct vnode *vp; 174 { 175 176 /* 177 * If there's shared text associated with 178 * the vnode, try to free it up once. If 179 * we fail, we can't allow writing. 180 */ 181 if ((vp->v_flag & VTEXT) && !uvm_vnp_uncache(vp)) 182 return (ETXTBSY); 183 return (0); 184 } 185 186 /* 187 * Mark a vnode as being the text image of a running process. 188 */ 189 void 190 vn_marktext(vp) 191 struct vnode *vp; 192 { 193 vp->v_flag |= VTEXT; 194 } 195 196 /* 197 * Vnode close call 198 * 199 * Note: takes an unlocked vnode, while VOP_CLOSE takes a locked node. 200 */ 201 int 202 vn_close(vp, flags, cred, p) 203 struct vnode *vp; 204 int flags; 205 struct ucred *cred; 206 struct proc *p; 207 { 208 int error; 209 210 if (flags & FWRITE) 211 vp->v_writecount--; 212 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 213 error = VOP_CLOSE(vp, flags, cred, p); 214 vput(vp); 215 return (error); 216 } 217 218 /* 219 * Package up an I/O request on a vnode into a uio and do it. 220 */ 221 int 222 vn_rdwr(rw, vp, base, len, offset, segflg, ioflg, cred, aresid, p) 223 enum uio_rw rw; 224 struct vnode *vp; 225 caddr_t base; 226 int len; 227 off_t offset; 228 enum uio_seg segflg; 229 int ioflg; 230 struct ucred *cred; 231 size_t *aresid; 232 struct proc *p; 233 { 234 struct uio auio; 235 struct iovec aiov; 236 int error; 237 238 if ((ioflg & IO_NODELOCKED) == 0) 239 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 240 auio.uio_iov = &aiov; 241 auio.uio_iovcnt = 1; 242 aiov.iov_base = base; 243 aiov.iov_len = len; 244 auio.uio_resid = len; 245 auio.uio_offset = offset; 246 auio.uio_segflg = segflg; 247 auio.uio_rw = rw; 248 auio.uio_procp = p; 249 if (rw == UIO_READ) { 250 error = VOP_READ(vp, &auio, ioflg, cred); 251 } else { 252 error = VOP_WRITE(vp, &auio, ioflg, cred); 253 } 254 if (aresid) 255 *aresid = auio.uio_resid; 256 else 257 if (auio.uio_resid && error == 0) 258 error = EIO; 259 if ((ioflg & IO_NODELOCKED) == 0) 260 VOP_UNLOCK(vp, 0); 261 return (error); 262 } 263 264 int 265 vn_readdir(fp, buf, segflg, count, done, p, cookies, ncookies) 266 struct file *fp; 267 char *buf; 268 int segflg, *done, *ncookies; 269 u_int count; 270 struct proc *p; 271 off_t **cookies; 272 { 273 struct vnode *vp = (struct vnode *)fp->f_data; 274 struct iovec aiov; 275 struct uio auio; 276 int error, eofflag; 277 278 unionread: 279 if (vp->v_type != VDIR) 280 return (EINVAL); 281 aiov.iov_base = buf; 282 aiov.iov_len = count; 283 auio.uio_iov = &aiov; 284 auio.uio_iovcnt = 1; 285 auio.uio_rw = UIO_READ; 286 auio.uio_segflg = segflg; 287 auio.uio_procp = p; 288 auio.uio_resid = count; 289 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 290 auio.uio_offset = fp->f_offset; 291 error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, cookies, 292 ncookies); 293 fp->f_offset = auio.uio_offset; 294 VOP_UNLOCK(vp, 0); 295 if (error) 296 return (error); 297 298 #ifdef UNION 299 { 300 extern struct vnode *union_dircache __P((struct vnode *)); 301 302 if (count == auio.uio_resid && (vp->v_op == union_vnodeop_p)) { 303 struct vnode *lvp; 304 305 lvp = union_dircache(vp); 306 if (lvp != NULLVP) { 307 struct vattr va; 308 309 /* 310 * If the directory is opaque, 311 * then don't show lower entries 312 */ 313 error = VOP_GETATTR(vp, &va, fp->f_cred, p); 314 if (va.va_flags & OPAQUE) { 315 vput(lvp); 316 lvp = NULL; 317 } 318 } 319 320 if (lvp != NULLVP) { 321 error = VOP_OPEN(lvp, FREAD, fp->f_cred, p); 322 if (error) { 323 vput(lvp); 324 return (error); 325 } 326 VOP_UNLOCK(lvp, 0); 327 fp->f_data = (caddr_t) lvp; 328 fp->f_offset = 0; 329 error = vn_close(vp, FREAD, fp->f_cred, p); 330 if (error) 331 return (error); 332 vp = lvp; 333 goto unionread; 334 } 335 } 336 } 337 #endif /* UNION */ 338 339 if (count == auio.uio_resid && (vp->v_flag & VROOT) && 340 (vp->v_mount->mnt_flag & MNT_UNION)) { 341 struct vnode *tvp = vp; 342 vp = vp->v_mount->mnt_vnodecovered; 343 VREF(vp); 344 fp->f_data = (caddr_t) vp; 345 fp->f_offset = 0; 346 vrele(tvp); 347 goto unionread; 348 } 349 *done = count - auio.uio_resid; 350 return error; 351 } 352 353 /* 354 * File table vnode read routine. 355 */ 356 int 357 vn_read(fp, offset, uio, cred, flags) 358 struct file *fp; 359 off_t *offset; 360 struct uio *uio; 361 struct ucred *cred; 362 int flags; 363 { 364 struct vnode *vp = (struct vnode *)fp->f_data; 365 int count, error, ioflag = 0; 366 367 VOP_LEASE(vp, uio->uio_procp, cred, LEASE_READ); 368 if (fp->f_flag & FNONBLOCK) 369 ioflag |= IO_NDELAY; 370 if ((fp->f_flag & (FFSYNC | FRSYNC)) == (FFSYNC | FRSYNC)) 371 ioflag |= IO_SYNC; 372 if (fp->f_flag & FALTIO) 373 ioflag |= IO_ALTSEMANTICS; 374 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 375 uio->uio_offset = *offset; 376 count = uio->uio_resid; 377 error = VOP_READ(vp, uio, ioflag, cred); 378 if (flags & FOF_UPDATE_OFFSET) 379 *offset += count - uio->uio_resid; 380 VOP_UNLOCK(vp, 0); 381 return (error); 382 } 383 384 /* 385 * File table vnode write routine. 386 */ 387 int 388 vn_write(fp, offset, uio, cred, flags) 389 struct file *fp; 390 off_t *offset; 391 struct uio *uio; 392 struct ucred *cred; 393 int flags; 394 { 395 struct vnode *vp = (struct vnode *)fp->f_data; 396 int count, error, ioflag = IO_UNIT; 397 398 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 399 ioflag |= IO_APPEND; 400 if (fp->f_flag & FNONBLOCK) 401 ioflag |= IO_NDELAY; 402 if (fp->f_flag & FFSYNC || 403 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS))) 404 ioflag |= IO_SYNC; 405 else if (fp->f_flag & FDSYNC) 406 ioflag |= IO_DSYNC; 407 if (fp->f_flag & FALTIO) 408 ioflag |= IO_ALTSEMANTICS; 409 VOP_LEASE(vp, uio->uio_procp, cred, LEASE_WRITE); 410 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 411 uio->uio_offset = *offset; 412 count = uio->uio_resid; 413 error = VOP_WRITE(vp, uio, ioflag, cred); 414 if (flags & FOF_UPDATE_OFFSET) { 415 if (ioflag & IO_APPEND) 416 *offset = uio->uio_offset; 417 else 418 *offset += count - uio->uio_resid; 419 } 420 VOP_UNLOCK(vp, 0); 421 return (error); 422 } 423 424 /* 425 * File table vnode stat routine. 426 */ 427 int 428 vn_stat(vp, sb, p) 429 struct vnode *vp; 430 struct stat *sb; 431 struct proc *p; 432 { 433 struct vattr va; 434 int error; 435 mode_t mode; 436 437 error = VOP_GETATTR(vp, &va, p->p_ucred, p); 438 if (error) 439 return (error); 440 /* 441 * Copy from vattr table 442 */ 443 sb->st_dev = va.va_fsid; 444 sb->st_ino = va.va_fileid; 445 mode = va.va_mode; 446 switch (vp->v_type) { 447 case VREG: 448 mode |= S_IFREG; 449 break; 450 case VDIR: 451 mode |= S_IFDIR; 452 break; 453 case VBLK: 454 mode |= S_IFBLK; 455 break; 456 case VCHR: 457 mode |= S_IFCHR; 458 break; 459 case VLNK: 460 mode |= S_IFLNK; 461 break; 462 case VSOCK: 463 mode |= S_IFSOCK; 464 break; 465 case VFIFO: 466 mode |= S_IFIFO; 467 break; 468 default: 469 return (EBADF); 470 }; 471 sb->st_mode = mode; 472 sb->st_nlink = va.va_nlink; 473 sb->st_uid = va.va_uid; 474 sb->st_gid = va.va_gid; 475 sb->st_rdev = va.va_rdev; 476 sb->st_size = va.va_size; 477 sb->st_atimespec = va.va_atime; 478 sb->st_mtimespec = va.va_mtime; 479 sb->st_ctimespec = va.va_ctime; 480 sb->st_blksize = va.va_blocksize; 481 sb->st_flags = va.va_flags; 482 sb->st_gen = 0; 483 sb->st_blocks = va.va_bytes / S_BLKSIZE; 484 return (0); 485 } 486 487 /* 488 * File table vnode fcntl routine. 489 */ 490 int 491 vn_fcntl(fp, com, data, p) 492 struct file *fp; 493 u_int com; 494 caddr_t data; 495 struct proc *p; 496 { 497 struct vnode *vp = ((struct vnode *)fp->f_data); 498 int error; 499 500 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 501 error = VOP_FCNTL(vp, com, data, fp->f_flag, p->p_ucred, p); 502 VOP_UNLOCK(vp, 0); 503 return (error); 504 } 505 506 /* 507 * File table vnode ioctl routine. 508 */ 509 int 510 vn_ioctl(fp, com, data, p) 511 struct file *fp; 512 u_long com; 513 caddr_t data; 514 struct proc *p; 515 { 516 struct vnode *vp = ((struct vnode *)fp->f_data); 517 struct vattr vattr; 518 int error; 519 520 switch (vp->v_type) { 521 522 case VREG: 523 case VDIR: 524 if (com == FIONREAD) { 525 error = VOP_GETATTR(vp, &vattr, p->p_ucred, p); 526 if (error) 527 return (error); 528 *(int *)data = vattr.va_size - fp->f_offset; 529 return (0); 530 } 531 if (com == FIONBIO || com == FIOASYNC) /* XXX */ 532 return (0); /* XXX */ 533 /* fall into ... */ 534 535 default: 536 return (ENOTTY); 537 538 case VFIFO: 539 case VCHR: 540 case VBLK: 541 error = VOP_IOCTL(vp, com, data, fp->f_flag, p->p_ucred, p); 542 if (error == 0 && com == TIOCSCTTY) { 543 if (p->p_session->s_ttyvp) 544 vrele(p->p_session->s_ttyvp); 545 p->p_session->s_ttyvp = vp; 546 VREF(vp); 547 } 548 return (error); 549 } 550 } 551 552 /* 553 * File table vnode poll routine. 554 */ 555 int 556 vn_poll(fp, events, p) 557 struct file *fp; 558 int events; 559 struct proc *p; 560 { 561 562 return (VOP_POLL(((struct vnode *)fp->f_data), events, p)); 563 } 564 565 /* 566 * Check that the vnode is still valid, and if so 567 * acquire requested lock. 568 */ 569 int 570 vn_lock(vp, flags) 571 struct vnode *vp; 572 int flags; 573 { 574 int error; 575 576 do { 577 if ((flags & LK_INTERLOCK) == 0) 578 simple_lock(&vp->v_interlock); 579 if (vp->v_flag & VXLOCK) { 580 vp->v_flag |= VXWANT; 581 simple_unlock(&vp->v_interlock); 582 tsleep((caddr_t)vp, PINOD, "vn_lock", 0); 583 error = ENOENT; 584 } else { 585 error = VOP_LOCK(vp, flags | LK_INTERLOCK); 586 if (error == 0 || error == EDEADLK) 587 return (error); 588 } 589 flags &= ~LK_INTERLOCK; 590 } while (flags & LK_RETRY); 591 return (error); 592 } 593 594 /* 595 * File table vnode close routine. 596 */ 597 int 598 vn_closefile(fp, p) 599 struct file *fp; 600 struct proc *p; 601 { 602 603 return (vn_close(((struct vnode *)fp->f_data), fp->f_flag, 604 fp->f_cred, p)); 605 } 606 607 /* 608 * Enable LK_CANRECURSE on lock. Return prior status. 609 */ 610 u_int 611 vn_setrecurse(vp) 612 struct vnode *vp; 613 { 614 struct lock *lkp = &vp->v_lock; 615 u_int retval = lkp->lk_flags & LK_CANRECURSE; 616 617 lkp->lk_flags |= LK_CANRECURSE; 618 return retval; 619 } 620 621 /* 622 * Called when done with locksetrecurse. 623 */ 624 void 625 vn_restorerecurse(vp, flags) 626 struct vnode *vp; 627 u_int flags; 628 { 629 struct lock *lkp = &vp->v_lock; 630 631 lkp->lk_flags &= ~LK_CANRECURSE; 632 lkp->lk_flags |= flags; 633 } 634
Indexes created Sat Sep 20 22:09:52 GMT 2025