vfs_vnops.c revision 1.37
1 /* $NetBSD: vfs_vnops.c,v 1.37 1999/08/03 20:19:17 wrstuden 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 register struct nameidata *ndp; 77 int fmode, cmode; 78 { 79 register struct vnode *vp; 80 register struct proc *p = ndp->ni_cnd.cn_proc; 81 register 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 ndp->ni_cnd.cn_flags |= FOLLOW; 90 if ((error = namei(ndp)) != 0) 91 return (error); 92 if (ndp->ni_vp == NULL) { 93 VATTR_NULL(&va); 94 va.va_type = VREG; 95 va.va_mode = cmode; 96 if (fmode & O_EXCL) 97 va.va_vaflags |= VA_EXCLUSIVE; 98 VOP_LEASE(ndp->ni_dvp, p, cred, LEASE_WRITE); 99 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp, 100 &ndp->ni_cnd, &va); 101 if (error) 102 return (error); 103 fmode &= ~O_TRUNC; 104 vp = ndp->ni_vp; 105 } else { 106 VOP_ABORTOP(ndp->ni_dvp, &ndp->ni_cnd); 107 if (ndp->ni_dvp == ndp->ni_vp) 108 vrele(ndp->ni_dvp); 109 else 110 vput(ndp->ni_dvp); 111 ndp->ni_dvp = NULL; 112 vp = ndp->ni_vp; 113 if (fmode & O_EXCL) { 114 error = EEXIST; 115 goto bad; 116 } 117 fmode &= ~O_CREAT; 118 } 119 } else { 120 ndp->ni_cnd.cn_nameiop = LOOKUP; 121 ndp->ni_cnd.cn_flags = FOLLOW | LOCKLEAF; 122 if ((error = namei(ndp)) != 0) 123 return (error); 124 vp = ndp->ni_vp; 125 } 126 if (vp->v_type == VSOCK) { 127 error = EOPNOTSUPP; 128 goto bad; 129 } 130 if ((fmode & O_CREAT) == 0) { 131 if (fmode & FREAD) { 132 if ((error = VOP_ACCESS(vp, VREAD, cred, p)) != 0) 133 goto bad; 134 } 135 if (fmode & (FWRITE | O_TRUNC)) { 136 if (vp->v_type == VDIR) { 137 error = EISDIR; 138 goto bad; 139 } 140 if ((error = vn_writechk(vp)) != 0 || 141 (error = VOP_ACCESS(vp, VWRITE, cred, p)) != 0) 142 goto bad; 143 } 144 } 145 if (fmode & O_TRUNC) { 146 VOP_UNLOCK(vp, 0); /* XXX */ 147 VOP_LEASE(vp, p, cred, LEASE_WRITE); 148 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); /* XXX */ 149 VATTR_NULL(&va); 150 va.va_size = 0; 151 if ((error = VOP_SETATTR(vp, &va, cred, p)) != 0) 152 goto bad; 153 } 154 if ((error = VOP_OPEN(vp, fmode, cred, p)) != 0) 155 goto bad; 156 if (fmode & FWRITE) 157 vp->v_writecount++; 158 return (0); 159 bad: 160 vput(vp); 161 return (error); 162 } 163 164 /* 165 * Check for write permissions on the specified vnode. 166 * Prototype text segments cannot be written. 167 */ 168 int 169 vn_writechk(vp) 170 register struct vnode *vp; 171 { 172 173 /* 174 * If there's shared text associated with 175 * the vnode, try to free it up once. If 176 * we fail, we can't allow writing. 177 */ 178 if ((vp->v_flag & VTEXT) && !uvm_vnp_uncache(vp)) 179 return (ETXTBSY); 180 return (0); 181 } 182 183 /* 184 * Vnode close call 185 * 186 * Note: takes an unlocked vnode, while VOP_CLOSE takes a locked node. 187 */ 188 int 189 vn_close(vp, flags, cred, p) 190 register struct vnode *vp; 191 int flags; 192 struct ucred *cred; 193 struct proc *p; 194 { 195 int error; 196 197 if (flags & FWRITE) 198 vp->v_writecount--; 199 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 200 error = VOP_CLOSE(vp, flags, cred, p); 201 vput(vp); 202 return (error); 203 } 204 205 /* 206 * Package up an I/O request on a vnode into a uio and do it. 207 */ 208 int 209 vn_rdwr(rw, vp, base, len, offset, segflg, ioflg, cred, aresid, p) 210 enum uio_rw rw; 211 struct vnode *vp; 212 caddr_t base; 213 int len; 214 off_t offset; 215 enum uio_seg segflg; 216 int ioflg; 217 struct ucred *cred; 218 size_t *aresid; 219 struct proc *p; 220 { 221 struct uio auio; 222 struct iovec aiov; 223 int error; 224 225 if ((ioflg & IO_NODELOCKED) == 0) 226 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 227 auio.uio_iov = &aiov; 228 auio.uio_iovcnt = 1; 229 aiov.iov_base = base; 230 aiov.iov_len = len; 231 auio.uio_resid = len; 232 auio.uio_offset = offset; 233 auio.uio_segflg = segflg; 234 auio.uio_rw = rw; 235 auio.uio_procp = p; 236 if (rw == UIO_READ) { 237 error = VOP_READ(vp, &auio, ioflg, cred); 238 } else { 239 error = VOP_WRITE(vp, &auio, ioflg, cred); 240 } 241 if (aresid) 242 *aresid = auio.uio_resid; 243 else 244 if (auio.uio_resid && error == 0) 245 error = EIO; 246 if ((ioflg & IO_NODELOCKED) == 0) 247 VOP_UNLOCK(vp, 0); 248 return (error); 249 } 250 251 int 252 vn_readdir(fp, buf, segflg, count, done, p, cookies, ncookies) 253 struct file *fp; 254 char *buf; 255 int segflg, *done, *ncookies; 256 u_int count; 257 struct proc *p; 258 off_t **cookies; 259 { 260 struct vnode *vp = (struct vnode *)fp->f_data; 261 struct iovec aiov; 262 struct uio auio; 263 int error, eofflag; 264 265 unionread: 266 if (vp->v_type != VDIR) 267 return (EINVAL); 268 aiov.iov_base = buf; 269 aiov.iov_len = count; 270 auio.uio_iov = &aiov; 271 auio.uio_iovcnt = 1; 272 auio.uio_rw = UIO_READ; 273 auio.uio_segflg = segflg; 274 auio.uio_procp = p; 275 auio.uio_resid = count; 276 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 277 auio.uio_offset = fp->f_offset; 278 error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, cookies, 279 ncookies); 280 fp->f_offset = auio.uio_offset; 281 VOP_UNLOCK(vp, 0); 282 if (error) 283 return (error); 284 285 #ifdef UNION 286 { 287 extern int (**union_vnodeop_p) __P((void *)); 288 extern struct vnode *union_dircache __P((struct vnode *)); 289 290 if (count == auio.uio_resid && (vp->v_op == union_vnodeop_p)) { 291 struct vnode *lvp; 292 293 lvp = union_dircache(vp); 294 if (lvp != NULLVP) { 295 struct vattr va; 296 297 /* 298 * If the directory is opaque, 299 * then don't show lower entries 300 */ 301 error = VOP_GETATTR(vp, &va, fp->f_cred, p); 302 if (va.va_flags & OPAQUE) { 303 vput(lvp); 304 lvp = NULL; 305 } 306 } 307 308 if (lvp != NULLVP) { 309 error = VOP_OPEN(lvp, FREAD, fp->f_cred, p); 310 if (error) { 311 vput(lvp); 312 return (error); 313 } 314 VOP_UNLOCK(lvp, 0); 315 fp->f_data = (caddr_t) lvp; 316 fp->f_offset = 0; 317 error = vn_close(vp, FREAD, fp->f_cred, p); 318 if (error) 319 return (error); 320 vp = lvp; 321 goto unionread; 322 } 323 } 324 } 325 #endif /* UNION */ 326 327 if (count == auio.uio_resid && (vp->v_flag & VROOT) && 328 (vp->v_mount->mnt_flag & MNT_UNION)) { 329 struct vnode *tvp = vp; 330 vp = vp->v_mount->mnt_vnodecovered; 331 VREF(vp); 332 fp->f_data = (caddr_t) vp; 333 fp->f_offset = 0; 334 vrele(tvp); 335 goto unionread; 336 } 337 *done = count - auio.uio_resid; 338 return error; 339 } 340 341 /* 342 * File table vnode read routine. 343 */ 344 int 345 vn_read(fp, offset, uio, cred, flags) 346 struct file *fp; 347 off_t *offset; 348 struct uio *uio; 349 struct ucred *cred; 350 int flags; 351 { 352 struct vnode *vp = (struct vnode *)fp->f_data; 353 int count, error, ioflag = 0; 354 355 VOP_LEASE(vp, uio->uio_procp, cred, LEASE_READ); 356 if (fp->f_flag & FNONBLOCK) 357 ioflag |= IO_NDELAY; 358 if ((fp->f_flag & (FFSYNC | FRSYNC)) == (FFSYNC | FRSYNC)) 359 ioflag |= IO_SYNC; 360 if (fp->f_flag & FALTIO) 361 ioflag |= IO_ALTSEMANTICS; 362 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 363 uio->uio_offset = *offset; 364 count = uio->uio_resid; 365 error = VOP_READ(vp, uio, ioflag, cred); 366 if (flags & FOF_UPDATE_OFFSET) 367 *offset += count - uio->uio_resid; 368 VOP_UNLOCK(vp, 0); 369 return (error); 370 } 371 372 /* 373 * File table vnode write routine. 374 */ 375 int 376 vn_write(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 = IO_UNIT; 385 386 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 387 ioflag |= IO_APPEND; 388 if (fp->f_flag & FNONBLOCK) 389 ioflag |= IO_NDELAY; 390 if (fp->f_flag & FFSYNC || 391 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS))) 392 ioflag |= IO_SYNC; 393 else if (fp->f_flag & FDSYNC) 394 ioflag |= IO_DSYNC; 395 if (fp->f_flag & FALTIO) 396 ioflag |= IO_ALTSEMANTICS; 397 VOP_LEASE(vp, uio->uio_procp, cred, LEASE_WRITE); 398 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 399 uio->uio_offset = *offset; 400 count = uio->uio_resid; 401 error = VOP_WRITE(vp, uio, ioflag, cred); 402 if (flags & FOF_UPDATE_OFFSET) { 403 if (ioflag & IO_APPEND) 404 *offset = uio->uio_offset; 405 else 406 *offset += count - uio->uio_resid; 407 } 408 VOP_UNLOCK(vp, 0); 409 return (error); 410 } 411 412 /* 413 * File table vnode stat routine. 414 */ 415 int 416 vn_stat(vp, sb, p) 417 struct vnode *vp; 418 register struct stat *sb; 419 struct proc *p; 420 { 421 struct vattr va; 422 int error; 423 mode_t mode; 424 425 error = VOP_GETATTR(vp, &va, p->p_ucred, p); 426 if (error) 427 return (error); 428 /* 429 * Copy from vattr table 430 */ 431 sb->st_dev = va.va_fsid; 432 sb->st_ino = va.va_fileid; 433 mode = va.va_mode; 434 switch (vp->v_type) { 435 case VREG: 436 mode |= S_IFREG; 437 break; 438 case VDIR: 439 mode |= S_IFDIR; 440 break; 441 case VBLK: 442 mode |= S_IFBLK; 443 break; 444 case VCHR: 445 mode |= S_IFCHR; 446 break; 447 case VLNK: 448 mode |= S_IFLNK; 449 break; 450 case VSOCK: 451 mode |= S_IFSOCK; 452 break; 453 case VFIFO: 454 mode |= S_IFIFO; 455 break; 456 default: 457 return (EBADF); 458 }; 459 sb->st_mode = mode; 460 sb->st_nlink = va.va_nlink; 461 sb->st_uid = va.va_uid; 462 sb->st_gid = va.va_gid; 463 sb->st_rdev = va.va_rdev; 464 sb->st_size = va.va_size; 465 sb->st_atimespec = va.va_atime; 466 sb->st_mtimespec = va.va_mtime; 467 sb->st_ctimespec = va.va_ctime; 468 sb->st_blksize = va.va_blocksize; 469 sb->st_flags = va.va_flags; 470 sb->st_gen = 0; 471 sb->st_blocks = va.va_bytes / S_BLKSIZE; 472 return (0); 473 } 474 475 /* 476 * File table vnode fcntl routine. 477 */ 478 int 479 vn_fcntl(fp, com, data, p) 480 struct file *fp; 481 u_int com; 482 caddr_t data; 483 struct proc *p; 484 { 485 register struct vnode *vp = ((struct vnode *)fp->f_data); 486 int error; 487 488 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 489 error = VOP_FCNTL(vp, com, data, fp->f_flag, p->p_ucred, p); 490 VOP_UNLOCK(vp, 0); 491 return (error); 492 } 493 494 /* 495 * File table vnode ioctl routine. 496 */ 497 int 498 vn_ioctl(fp, com, data, p) 499 struct file *fp; 500 u_long com; 501 caddr_t data; 502 struct proc *p; 503 { 504 register struct vnode *vp = ((struct vnode *)fp->f_data); 505 struct vattr vattr; 506 int error; 507 508 switch (vp->v_type) { 509 510 case VREG: 511 case VDIR: 512 if (com == FIONREAD) { 513 error = VOP_GETATTR(vp, &vattr, p->p_ucred, p); 514 if (error) 515 return (error); 516 *(int *)data = vattr.va_size - fp->f_offset; 517 return (0); 518 } 519 if (com == FIONBIO || com == FIOASYNC) /* XXX */ 520 return (0); /* XXX */ 521 /* fall into ... */ 522 523 default: 524 return (ENOTTY); 525 526 case VFIFO: 527 case VCHR: 528 case VBLK: 529 error = VOP_IOCTL(vp, com, data, fp->f_flag, p->p_ucred, p); 530 if (error == 0 && com == TIOCSCTTY) { 531 if (p->p_session->s_ttyvp) 532 vrele(p->p_session->s_ttyvp); 533 p->p_session->s_ttyvp = vp; 534 VREF(vp); 535 } 536 return (error); 537 } 538 } 539 540 /* 541 * File table vnode poll routine. 542 */ 543 int 544 vn_poll(fp, events, p) 545 struct file *fp; 546 int events; 547 struct proc *p; 548 { 549 550 return (VOP_POLL(((struct vnode *)fp->f_data), events, p)); 551 } 552 553 /* 554 * Check that the vnode is still valid, and if so 555 * acquire requested lock. 556 */ 557 int 558 vn_lock(vp, flags) 559 struct vnode *vp; 560 int flags; 561 { 562 int error; 563 564 do { 565 if ((flags & LK_INTERLOCK) == 0) 566 simple_lock(&vp->v_interlock); 567 if (vp->v_flag & VXLOCK) { 568 vp->v_flag |= VXWANT; 569 simple_unlock(&vp->v_interlock); 570 tsleep((caddr_t)vp, PINOD, "vn_lock", 0); 571 error = ENOENT; 572 } else { 573 error = VOP_LOCK(vp, flags | LK_INTERLOCK); 574 if (error == 0 || error == EDEADLK) 575 return (error); 576 } 577 flags &= ~LK_INTERLOCK; 578 } while (flags & LK_RETRY); 579 return (error); 580 } 581 582 /* 583 * File table vnode close routine. 584 */ 585 int 586 vn_closefile(fp, p) 587 struct file *fp; 588 struct proc *p; 589 { 590 591 return (vn_close(((struct vnode *)fp->f_data), fp->f_flag, 592 fp->f_cred, p)); 593 } 594
Indexes created Sat Sep 20 22:09:52 GMT 2025