vfs_vnops.c revision 1.36.4.1
1 /* $NetBSD: vfs_vnops.c,v 1.36.4.1 1999/06/07 04:25:31 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_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 (vp->v_type == VREG && 157 uvn_attach(vp, fmode & FWRITE ? VM_PROT_WRITE : 0) == NULL) { 158 error = EIO; 159 goto bad; 160 } 161 if (fmode & FWRITE) 162 vp->v_writecount++; 163 164 return (0); 165 bad: 166 vput(vp); 167 return (error); 168 } 169 170 /* 171 * Check for write permissions on the specified vnode. 172 * Prototype text segments cannot be written. 173 */ 174 int 175 vn_writechk(vp) 176 register struct vnode *vp; 177 { 178 179 /* 180 * If there's shared text associated with 181 * the vnode, try to free it up once. If 182 * we fail, we can't allow writing. 183 */ 184 if ((vp->v_flag & VTEXT) && !uvm_vnp_uncache(vp)) 185 return (ETXTBSY); 186 return (0); 187 } 188 189 /* 190 * Vnode close call 191 * 192 * Note: takes an unlocked vnode, while VOP_CLOSE takes a locked node. 193 */ 194 int 195 vn_close(vp, flags, cred, p) 196 register struct vnode *vp; 197 int flags; 198 struct ucred *cred; 199 struct proc *p; 200 { 201 int error; 202 203 if (flags & FWRITE) 204 vp->v_writecount--; 205 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 206 error = VOP_CLOSE(vp, flags, cred, p); 207 vput(vp); 208 return (error); 209 } 210 211 /* 212 * Package up an I/O request on a vnode into a uio and do it. 213 */ 214 int 215 vn_rdwr(rw, vp, base, len, offset, segflg, ioflg, cred, aresid, p) 216 enum uio_rw rw; 217 struct vnode *vp; 218 caddr_t base; 219 int len; 220 off_t offset; 221 enum uio_seg segflg; 222 int ioflg; 223 struct ucred *cred; 224 size_t *aresid; 225 struct proc *p; 226 { 227 struct uio auio; 228 struct iovec aiov; 229 int error; 230 231 if ((ioflg & IO_NODELOCKED) == 0) 232 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 233 auio.uio_iov = &aiov; 234 auio.uio_iovcnt = 1; 235 aiov.iov_base = base; 236 aiov.iov_len = len; 237 auio.uio_resid = len; 238 auio.uio_offset = offset; 239 auio.uio_segflg = segflg; 240 auio.uio_rw = rw; 241 auio.uio_procp = p; 242 if (rw == UIO_READ) { 243 error = VOP_READ(vp, &auio, ioflg, cred); 244 } else { 245 error = VOP_WRITE(vp, &auio, ioflg, cred); 246 } 247 if (aresid) 248 *aresid = auio.uio_resid; 249 else 250 if (auio.uio_resid && error == 0) 251 error = EIO; 252 if ((ioflg & IO_NODELOCKED) == 0) 253 VOP_UNLOCK(vp, 0); 254 return (error); 255 } 256 257 int 258 vn_readdir(fp, buf, segflg, count, done, p, cookies, ncookies) 259 struct file *fp; 260 char *buf; 261 int segflg, *done, *ncookies; 262 u_int count; 263 struct proc *p; 264 off_t **cookies; 265 { 266 struct vnode *vp = (struct vnode *)fp->f_data; 267 struct iovec aiov; 268 struct uio auio; 269 int error, eofflag; 270 271 unionread: 272 if (vp->v_type != VDIR) 273 return (EINVAL); 274 aiov.iov_base = buf; 275 aiov.iov_len = count; 276 auio.uio_iov = &aiov; 277 auio.uio_iovcnt = 1; 278 auio.uio_rw = UIO_READ; 279 auio.uio_segflg = segflg; 280 auio.uio_procp = p; 281 auio.uio_resid = count; 282 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 283 auio.uio_offset = fp->f_offset; 284 error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, cookies, 285 ncookies); 286 fp->f_offset = auio.uio_offset; 287 VOP_UNLOCK(vp, 0); 288 if (error) 289 return (error); 290 291 #ifdef UNION 292 { 293 extern int (**union_vnodeop_p) __P((void *)); 294 extern struct vnode *union_dircache __P((struct vnode *)); 295 296 if (count == auio.uio_resid && (vp->v_op == union_vnodeop_p)) { 297 struct vnode *lvp; 298 299 lvp = union_dircache(vp); 300 if (lvp != NULLVP) { 301 struct vattr va; 302 303 /* 304 * If the directory is opaque, 305 * then don't show lower entries 306 */ 307 error = VOP_GETATTR(vp, &va, fp->f_cred, p); 308 if (va.va_flags & OPAQUE) { 309 vput(lvp); 310 lvp = NULL; 311 } 312 } 313 314 if (lvp != NULLVP) { 315 error = VOP_OPEN(lvp, FREAD, fp->f_cred, p); 316 if (error) { 317 vput(lvp); 318 return (error); 319 } 320 VOP_UNLOCK(lvp, 0); 321 fp->f_data = (caddr_t) lvp; 322 fp->f_offset = 0; 323 error = vn_close(vp, FREAD, fp->f_cred, p); 324 if (error) 325 return (error); 326 vp = lvp; 327 goto unionread; 328 } 329 } 330 } 331 #endif /* UNION */ 332 333 if (count == auio.uio_resid && (vp->v_flag & VROOT) && 334 (vp->v_mount->mnt_flag & MNT_UNION)) { 335 struct vnode *tvp = vp; 336 vp = vp->v_mount->mnt_vnodecovered; 337 VREF(vp); 338 fp->f_data = (caddr_t) vp; 339 fp->f_offset = 0; 340 vrele(tvp); 341 goto unionread; 342 } 343 *done = count - auio.uio_resid; 344 return error; 345 } 346 347 /* 348 * File table vnode read routine. 349 */ 350 int 351 vn_read(fp, offset, uio, cred, flags) 352 struct file *fp; 353 off_t *offset; 354 struct uio *uio; 355 struct ucred *cred; 356 int flags; 357 { 358 struct vnode *vp = (struct vnode *)fp->f_data; 359 int count, error, ioflag = 0; 360 361 VOP_LEASE(vp, uio->uio_procp, cred, LEASE_READ); 362 if (fp->f_flag & FNONBLOCK) 363 ioflag |= IO_NDELAY; 364 if ((fp->f_flag & (FFSYNC | FRSYNC)) == (FFSYNC | FRSYNC)) 365 ioflag |= IO_SYNC; 366 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 367 uio->uio_offset = *offset; 368 count = uio->uio_resid; 369 error = VOP_READ(vp, uio, ioflag, cred); 370 if (flags & FOF_UPDATE_OFFSET) 371 *offset += count - uio->uio_resid; 372 VOP_UNLOCK(vp, 0); 373 return (error); 374 } 375 376 /* 377 * File table vnode write routine. 378 */ 379 int 380 vn_write(fp, offset, uio, cred, flags) 381 struct file *fp; 382 off_t *offset; 383 struct uio *uio; 384 struct ucred *cred; 385 int flags; 386 { 387 struct vnode *vp = (struct vnode *)fp->f_data; 388 int count, error, ioflag = IO_UNIT; 389 390 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 391 ioflag |= IO_APPEND; 392 if (fp->f_flag & FNONBLOCK) 393 ioflag |= IO_NDELAY; 394 if (fp->f_flag & FFSYNC || 395 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS))) 396 ioflag |= IO_SYNC; 397 else if (fp->f_flag & FDSYNC) 398 ioflag |= IO_DSYNC; 399 VOP_LEASE(vp, uio->uio_procp, cred, LEASE_WRITE); 400 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 401 uio->uio_offset = *offset; 402 count = uio->uio_resid; 403 error = VOP_WRITE(vp, uio, ioflag, cred); 404 if (flags & FOF_UPDATE_OFFSET) { 405 if (ioflag & IO_APPEND) 406 *offset = uio->uio_offset; 407 else 408 *offset += count - uio->uio_resid; 409 } 410 VOP_UNLOCK(vp, 0); 411 return (error); 412 } 413 414 /* 415 * File table vnode stat routine. 416 */ 417 int 418 vn_stat(vp, sb, p) 419 struct vnode *vp; 420 register struct stat *sb; 421 struct proc *p; 422 { 423 struct vattr va; 424 int error; 425 mode_t mode; 426 427 error = VOP_GETATTR(vp, &va, p->p_ucred, p); 428 if (error) 429 return (error); 430 /* 431 * Copy from vattr table 432 */ 433 sb->st_dev = va.va_fsid; 434 sb->st_ino = va.va_fileid; 435 mode = va.va_mode; 436 switch (vp->v_type) { 437 case VREG: 438 mode |= S_IFREG; 439 break; 440 case VDIR: 441 mode |= S_IFDIR; 442 break; 443 case VBLK: 444 mode |= S_IFBLK; 445 break; 446 case VCHR: 447 mode |= S_IFCHR; 448 break; 449 case VLNK: 450 mode |= S_IFLNK; 451 break; 452 case VSOCK: 453 mode |= S_IFSOCK; 454 break; 455 case VFIFO: 456 mode |= S_IFIFO; 457 break; 458 default: 459 return (EBADF); 460 }; 461 sb->st_mode = mode; 462 sb->st_nlink = va.va_nlink; 463 sb->st_uid = va.va_uid; 464 sb->st_gid = va.va_gid; 465 sb->st_rdev = va.va_rdev; 466 sb->st_size = va.va_size; 467 sb->st_atimespec = va.va_atime; 468 sb->st_mtimespec = va.va_mtime; 469 sb->st_ctimespec = va.va_ctime; 470 sb->st_blksize = va.va_blocksize; 471 sb->st_flags = va.va_flags; 472 sb->st_gen = 0; 473 sb->st_blocks = va.va_bytes / S_BLKSIZE; 474 return (0); 475 } 476 477 /* 478 * File table vnode ioctl routine. 479 */ 480 int 481 vn_ioctl(fp, com, data, p) 482 struct file *fp; 483 u_long com; 484 caddr_t data; 485 struct proc *p; 486 { 487 register struct vnode *vp = ((struct vnode *)fp->f_data); 488 struct vattr vattr; 489 int error; 490 491 switch (vp->v_type) { 492 493 case VREG: 494 case VDIR: 495 if (com == FIONREAD) { 496 error = VOP_GETATTR(vp, &vattr, p->p_ucred, p); 497 if (error) 498 return (error); 499 *(int *)data = vattr.va_size - fp->f_offset; 500 return (0); 501 } 502 if (com == FIONBIO || com == FIOASYNC) /* XXX */ 503 return (0); /* XXX */ 504 /* fall into ... */ 505 506 default: 507 return (ENOTTY); 508 509 case VFIFO: 510 case VCHR: 511 case VBLK: 512 error = VOP_IOCTL(vp, com, data, fp->f_flag, p->p_ucred, p); 513 if (error == 0 && com == TIOCSCTTY) { 514 if (p->p_session->s_ttyvp) 515 vrele(p->p_session->s_ttyvp); 516 p->p_session->s_ttyvp = vp; 517 VREF(vp); 518 } 519 return (error); 520 } 521 } 522 523 /* 524 * File table vnode poll routine. 525 */ 526 int 527 vn_poll(fp, events, p) 528 struct file *fp; 529 int events; 530 struct proc *p; 531 { 532 533 return (VOP_POLL(((struct vnode *)fp->f_data), events, p)); 534 } 535 536 /* 537 * Check that the vnode is still valid, and if so 538 * acquire requested lock. 539 */ 540 int 541 vn_lock(vp, flags) 542 struct vnode *vp; 543 int flags; 544 { 545 int error; 546 547 do { 548 if ((flags & LK_INTERLOCK) == 0) 549 simple_lock(&vp->v_interlock); 550 if (vp->v_flag & VXLOCK) { 551 vp->v_flag |= VXWANT; 552 simple_unlock(&vp->v_interlock); 553 tsleep((caddr_t)vp, PINOD, "vn_lock", 0); 554 error = ENOENT; 555 } else { 556 error = VOP_LOCK(vp, flags | LK_INTERLOCK); 557 if (error == 0 || error == EDEADLK) 558 return (error); 559 } 560 flags &= ~LK_INTERLOCK; 561 } while (flags & LK_RETRY); 562 return (error); 563 } 564 565 /* 566 * File table vnode close routine. 567 */ 568 int 569 vn_closefile(fp, p) 570 struct file *fp; 571 struct proc *p; 572 { 573 574 return (vn_close(((struct vnode *)fp->f_data), fp->f_flag, 575 fp->f_cred, p)); 576 } 577
Indexes created Sun Sep 21 19:09:51 GMT 2025