vfs_vnops.c revision 1.48
1 /* $NetBSD: vfs_vnops.c,v 1.48 2001/04/09 10:22:02 jdolecek 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; 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 if ((error = VOP_OPEN(vp, fmode, cred, p)) != 0) 162 goto bad; 163 if (vp->v_type == VREG && 164 uvn_attach(vp, fmode & FWRITE ? VM_PROT_WRITE : 0) == NULL) { 165 error = EIO; 166 goto bad; 167 } 168 if (fmode & FWRITE) 169 vp->v_writecount++; 170 171 return (0); 172 bad: 173 vput(vp); 174 return (error); 175 } 176 177 /* 178 * Check for write permissions on the specified vnode. 179 * Prototype text segments cannot be written. 180 */ 181 int 182 vn_writechk(vp) 183 struct vnode *vp; 184 { 185 186 /* 187 * If the vnode is in use as a process's text, 188 * we can't allow writing. 189 */ 190 if (vp->v_flag & VTEXT) 191 return (ETXTBSY); 192 return (0); 193 } 194 195 /* 196 * Mark a vnode as being the text image of a running process. 197 */ 198 void 199 vn_marktext(vp) 200 struct vnode *vp; 201 { 202 if ((vp->v_flag & VTEXT) == 0) { 203 uvmexp.vnodepages -= vp->v_uvm.u_obj.uo_npages; 204 uvmexp.vtextpages += vp->v_uvm.u_obj.uo_npages; 205 } 206 vp->v_flag |= VTEXT; 207 } 208 209 /* 210 * Vnode close call 211 * 212 * Note: takes an unlocked vnode, while VOP_CLOSE takes a locked node. 213 */ 214 int 215 vn_close(vp, flags, cred, p) 216 struct vnode *vp; 217 int flags; 218 struct ucred *cred; 219 struct proc *p; 220 { 221 int error; 222 223 if (flags & FWRITE) 224 vp->v_writecount--; 225 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 226 error = VOP_CLOSE(vp, flags, cred, p); 227 vput(vp); 228 return (error); 229 } 230 231 /* 232 * Package up an I/O request on a vnode into a uio and do it. 233 */ 234 int 235 vn_rdwr(rw, vp, base, len, offset, segflg, ioflg, cred, aresid, p) 236 enum uio_rw rw; 237 struct vnode *vp; 238 caddr_t base; 239 int len; 240 off_t offset; 241 enum uio_seg segflg; 242 int ioflg; 243 struct ucred *cred; 244 size_t *aresid; 245 struct proc *p; 246 { 247 struct uio auio; 248 struct iovec aiov; 249 int error; 250 251 if ((ioflg & IO_NODELOCKED) == 0) 252 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 253 auio.uio_iov = &aiov; 254 auio.uio_iovcnt = 1; 255 aiov.iov_base = base; 256 aiov.iov_len = len; 257 auio.uio_resid = len; 258 auio.uio_offset = offset; 259 auio.uio_segflg = segflg; 260 auio.uio_rw = rw; 261 auio.uio_procp = p; 262 if (rw == UIO_READ) { 263 error = VOP_READ(vp, &auio, ioflg, cred); 264 } else { 265 error = VOP_WRITE(vp, &auio, ioflg, cred); 266 } 267 if (aresid) 268 *aresid = auio.uio_resid; 269 else 270 if (auio.uio_resid && error == 0) 271 error = EIO; 272 if ((ioflg & IO_NODELOCKED) == 0) 273 VOP_UNLOCK(vp, 0); 274 return (error); 275 } 276 277 int 278 vn_readdir(fp, buf, segflg, count, done, p, cookies, ncookies) 279 struct file *fp; 280 char *buf; 281 int segflg, *done, *ncookies; 282 u_int count; 283 struct proc *p; 284 off_t **cookies; 285 { 286 struct vnode *vp = (struct vnode *)fp->f_data; 287 struct iovec aiov; 288 struct uio auio; 289 int error, eofflag; 290 291 unionread: 292 if (vp->v_type != VDIR) 293 return (EINVAL); 294 aiov.iov_base = buf; 295 aiov.iov_len = count; 296 auio.uio_iov = &aiov; 297 auio.uio_iovcnt = 1; 298 auio.uio_rw = UIO_READ; 299 auio.uio_segflg = segflg; 300 auio.uio_procp = p; 301 auio.uio_resid = count; 302 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 303 auio.uio_offset = fp->f_offset; 304 error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, cookies, 305 ncookies); 306 fp->f_offset = auio.uio_offset; 307 VOP_UNLOCK(vp, 0); 308 if (error) 309 return (error); 310 311 #ifdef UNION 312 { 313 extern struct vnode *union_dircache __P((struct vnode *)); 314 315 if (count == auio.uio_resid && (vp->v_op == union_vnodeop_p)) { 316 struct vnode *lvp; 317 318 lvp = union_dircache(vp); 319 if (lvp != NULLVP) { 320 struct vattr va; 321 322 /* 323 * If the directory is opaque, 324 * then don't show lower entries 325 */ 326 error = VOP_GETATTR(vp, &va, fp->f_cred, p); 327 if (va.va_flags & OPAQUE) { 328 vput(lvp); 329 lvp = NULL; 330 } 331 } 332 333 if (lvp != NULLVP) { 334 error = VOP_OPEN(lvp, FREAD, fp->f_cred, p); 335 if (error) { 336 vput(lvp); 337 return (error); 338 } 339 VOP_UNLOCK(lvp, 0); 340 fp->f_data = (caddr_t) lvp; 341 fp->f_offset = 0; 342 error = vn_close(vp, FREAD, fp->f_cred, p); 343 if (error) 344 return (error); 345 vp = lvp; 346 goto unionread; 347 } 348 } 349 } 350 #endif /* UNION */ 351 352 if (count == auio.uio_resid && (vp->v_flag & VROOT) && 353 (vp->v_mount->mnt_flag & MNT_UNION)) { 354 struct vnode *tvp = vp; 355 vp = vp->v_mount->mnt_vnodecovered; 356 VREF(vp); 357 fp->f_data = (caddr_t) vp; 358 fp->f_offset = 0; 359 vrele(tvp); 360 goto unionread; 361 } 362 *done = count - auio.uio_resid; 363 return error; 364 } 365 366 /* 367 * File table vnode read routine. 368 */ 369 int 370 vn_read(fp, offset, uio, cred, flags) 371 struct file *fp; 372 off_t *offset; 373 struct uio *uio; 374 struct ucred *cred; 375 int flags; 376 { 377 struct vnode *vp = (struct vnode *)fp->f_data; 378 int count, error, ioflag = 0; 379 380 VOP_LEASE(vp, uio->uio_procp, cred, LEASE_READ); 381 if (fp->f_flag & FNONBLOCK) 382 ioflag |= IO_NDELAY; 383 if ((fp->f_flag & (FFSYNC | FRSYNC)) == (FFSYNC | FRSYNC)) 384 ioflag |= IO_SYNC; 385 if (fp->f_flag & FALTIO) 386 ioflag |= IO_ALTSEMANTICS; 387 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 388 uio->uio_offset = *offset; 389 count = uio->uio_resid; 390 error = VOP_READ(vp, uio, ioflag, cred); 391 if (flags & FOF_UPDATE_OFFSET) 392 *offset += count - uio->uio_resid; 393 VOP_UNLOCK(vp, 0); 394 return (error); 395 } 396 397 /* 398 * File table vnode write routine. 399 */ 400 int 401 vn_write(fp, offset, uio, cred, flags) 402 struct file *fp; 403 off_t *offset; 404 struct uio *uio; 405 struct ucred *cred; 406 int flags; 407 { 408 struct vnode *vp = (struct vnode *)fp->f_data; 409 int count, error, ioflag = IO_UNIT; 410 411 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 412 ioflag |= IO_APPEND; 413 if (fp->f_flag & FNONBLOCK) 414 ioflag |= IO_NDELAY; 415 if (fp->f_flag & FFSYNC || 416 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS))) 417 ioflag |= IO_SYNC; 418 else if (fp->f_flag & FDSYNC) 419 ioflag |= IO_DSYNC; 420 if (fp->f_flag & FALTIO) 421 ioflag |= IO_ALTSEMANTICS; 422 VOP_LEASE(vp, uio->uio_procp, cred, LEASE_WRITE); 423 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 424 uio->uio_offset = *offset; 425 count = uio->uio_resid; 426 error = VOP_WRITE(vp, uio, ioflag, cred); 427 if (flags & FOF_UPDATE_OFFSET) { 428 if (ioflag & IO_APPEND) 429 *offset = uio->uio_offset; 430 else 431 *offset += count - uio->uio_resid; 432 } 433 VOP_UNLOCK(vp, 0); 434 return (error); 435 } 436 437 /* 438 * File table vnode stat routine. 439 */ 440 static int 441 vn_statfile(fp, sb, p) 442 struct file *fp; 443 struct stat *sb; 444 struct proc *p; 445 { 446 struct vnode *vp = (struct vnode *)fp->f_data; 447 448 return vn_stat(vp, sb, p); 449 } 450 451 int 452 vn_stat(fdata, sb, p) 453 void *fdata; 454 struct stat *sb; 455 struct proc *p; 456 { 457 struct vnode *vp = fdata; 458 struct vattr va; 459 int error; 460 mode_t mode; 461 462 error = VOP_GETATTR(vp, &va, p->p_ucred, p); 463 if (error) 464 return (error); 465 /* 466 * Copy from vattr table 467 */ 468 sb->st_dev = va.va_fsid; 469 sb->st_ino = va.va_fileid; 470 mode = va.va_mode; 471 switch (vp->v_type) { 472 case VREG: 473 mode |= S_IFREG; 474 break; 475 case VDIR: 476 mode |= S_IFDIR; 477 break; 478 case VBLK: 479 mode |= S_IFBLK; 480 break; 481 case VCHR: 482 mode |= S_IFCHR; 483 break; 484 case VLNK: 485 mode |= S_IFLNK; 486 break; 487 case VSOCK: 488 mode |= S_IFSOCK; 489 break; 490 case VFIFO: 491 mode |= S_IFIFO; 492 break; 493 default: 494 return (EBADF); 495 }; 496 sb->st_mode = mode; 497 sb->st_nlink = va.va_nlink; 498 sb->st_uid = va.va_uid; 499 sb->st_gid = va.va_gid; 500 sb->st_rdev = va.va_rdev; 501 sb->st_size = va.va_size; 502 sb->st_atimespec = va.va_atime; 503 sb->st_mtimespec = va.va_mtime; 504 sb->st_ctimespec = va.va_ctime; 505 sb->st_blksize = va.va_blocksize; 506 sb->st_flags = va.va_flags; 507 sb->st_gen = 0; 508 sb->st_blocks = va.va_bytes / S_BLKSIZE; 509 return (0); 510 } 511 512 /* 513 * File table vnode fcntl routine. 514 */ 515 int 516 vn_fcntl(fp, com, data, p) 517 struct file *fp; 518 u_int com; 519 caddr_t data; 520 struct proc *p; 521 { 522 struct vnode *vp = ((struct vnode *)fp->f_data); 523 int error; 524 525 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 526 error = VOP_FCNTL(vp, com, data, fp->f_flag, p->p_ucred, p); 527 VOP_UNLOCK(vp, 0); 528 return (error); 529 } 530 531 /* 532 * File table vnode ioctl routine. 533 */ 534 int 535 vn_ioctl(fp, com, data, p) 536 struct file *fp; 537 u_long com; 538 caddr_t data; 539 struct proc *p; 540 { 541 struct vnode *vp = ((struct vnode *)fp->f_data); 542 struct vattr vattr; 543 int error; 544 545 switch (vp->v_type) { 546 547 case VREG: 548 case VDIR: 549 if (com == FIONREAD) { 550 error = VOP_GETATTR(vp, &vattr, p->p_ucred, p); 551 if (error) 552 return (error); 553 *(int *)data = vattr.va_size - fp->f_offset; 554 return (0); 555 } 556 if (com == FIONBIO || com == FIOASYNC) /* XXX */ 557 return (0); /* XXX */ 558 /* fall into ... */ 559 560 default: 561 return (ENOTTY); 562 563 case VFIFO: 564 case VCHR: 565 case VBLK: 566 error = VOP_IOCTL(vp, com, data, fp->f_flag, p->p_ucred, p); 567 if (error == 0 && com == TIOCSCTTY) { 568 if (p->p_session->s_ttyvp) 569 vrele(p->p_session->s_ttyvp); 570 p->p_session->s_ttyvp = vp; 571 VREF(vp); 572 } 573 return (error); 574 } 575 } 576 577 /* 578 * File table vnode poll routine. 579 */ 580 int 581 vn_poll(fp, events, p) 582 struct file *fp; 583 int events; 584 struct proc *p; 585 { 586 587 return (VOP_POLL(((struct vnode *)fp->f_data), events, p)); 588 } 589 590 /* 591 * Check that the vnode is still valid, and if so 592 * acquire requested lock. 593 */ 594 int 595 vn_lock(vp, flags) 596 struct vnode *vp; 597 int flags; 598 { 599 int error; 600 601 do { 602 if ((flags & LK_INTERLOCK) == 0) 603 simple_lock(&vp->v_interlock); 604 if (vp->v_flag & VXLOCK) { 605 vp->v_flag |= VXWANT; 606 ltsleep((caddr_t)vp, PINOD | PNORELOCK, 607 "vn_lock", 0, &vp->v_interlock); 608 error = ENOENT; 609 } else { 610 error = VOP_LOCK(vp, flags | LK_INTERLOCK); 611 if (error == 0 || error == EDEADLK) 612 return (error); 613 } 614 flags &= ~LK_INTERLOCK; 615 } while (flags & LK_RETRY); 616 return (error); 617 } 618 619 /* 620 * File table vnode close routine. 621 */ 622 int 623 vn_closefile(fp, p) 624 struct file *fp; 625 struct proc *p; 626 { 627 628 return (vn_close(((struct vnode *)fp->f_data), fp->f_flag, 629 fp->f_cred, p)); 630 } 631 632 /* 633 * Enable LK_CANRECURSE on lock. Return prior status. 634 */ 635 u_int 636 vn_setrecurse(vp) 637 struct vnode *vp; 638 { 639 struct lock *lkp = &vp->v_lock; 640 u_int retval = lkp->lk_flags & LK_CANRECURSE; 641 642 lkp->lk_flags |= LK_CANRECURSE; 643 return retval; 644 } 645 646 /* 647 * Called when done with locksetrecurse. 648 */ 649 void 650 vn_restorerecurse(vp, flags) 651 struct vnode *vp; 652 u_int flags; 653 { 654 struct lock *lkp = &vp->v_lock; 655 656 lkp->lk_flags &= ~LK_CANRECURSE; 657 lkp->lk_flags |= flags; 658 } 659
Indexes created Sun Sep 21 20:09:37 GMT 2025