vfs_vnops.c revision 1.32
1 /* $NetBSD: vfs_vnops.c,v 1.32 1999/02/26 23:38:55 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 #include "opt_uvm.h" 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 #include <sys/kernel.h> 49 #include <sys/file.h> 50 #include <sys/stat.h> 51 #include <sys/buf.h> 52 #include <sys/proc.h> 53 #include <sys/mount.h> 54 #include <sys/namei.h> 55 #include <sys/vnode.h> 56 #include <sys/ioctl.h> 57 #include <sys/tty.h> 58 #include <sys/poll.h> 59 60 #include <vm/vm.h> 61 62 #if defined(UVM) 63 #include <uvm/uvm_extern.h> 64 #endif 65 66 #ifdef UNION 67 #include <miscfs/union/union.h> 68 #endif 69 70 struct fileops vnops = 71 { vn_read, vn_write, vn_ioctl, vn_poll, vn_closefile }; 72 73 /* 74 * Common code for vnode open operations. 75 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine. 76 */ 77 int 78 vn_open(ndp, fmode, cmode) 79 register struct nameidata *ndp; 80 int fmode, cmode; 81 { 82 register struct vnode *vp; 83 register struct proc *p = ndp->ni_cnd.cn_proc; 84 register struct ucred *cred = p->p_ucred; 85 struct vattr va; 86 int error; 87 88 if (fmode & O_CREAT) { 89 ndp->ni_cnd.cn_nameiop = CREATE; 90 ndp->ni_cnd.cn_flags = LOCKPARENT | LOCKLEAF; 91 if ((fmode & O_EXCL) == 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 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 register 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 defined(UVM) 182 if ((vp->v_flag & VTEXT) && !uvm_vnp_uncache(vp)) 183 return (ETXTBSY); 184 #else 185 if ((vp->v_flag & VTEXT) && !vnode_pager_uncache(vp)) 186 return (ETXTBSY); 187 #endif 188 return (0); 189 } 190 191 /* 192 * Vnode close call 193 * 194 * Note: takes an unlocked vnode, while VOP_CLOSE takes a locked node. 195 */ 196 int 197 vn_close(vp, flags, cred, p) 198 register struct vnode *vp; 199 int flags; 200 struct ucred *cred; 201 struct proc *p; 202 { 203 int error; 204 205 if (flags & FWRITE) 206 vp->v_writecount--; 207 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 208 error = VOP_CLOSE(vp, flags, cred, p); 209 vput(vp); 210 return (error); 211 } 212 213 /* 214 * Package up an I/O request on a vnode into a uio and do it. 215 */ 216 int 217 vn_rdwr(rw, vp, base, len, offset, segflg, ioflg, cred, aresid, p) 218 enum uio_rw rw; 219 struct vnode *vp; 220 caddr_t base; 221 int len; 222 off_t offset; 223 enum uio_seg segflg; 224 int ioflg; 225 struct ucred *cred; 226 size_t *aresid; 227 struct proc *p; 228 { 229 struct uio auio; 230 struct iovec aiov; 231 int error; 232 233 if ((ioflg & IO_NODELOCKED) == 0) 234 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 235 auio.uio_iov = &aiov; 236 auio.uio_iovcnt = 1; 237 aiov.iov_base = base; 238 aiov.iov_len = len; 239 auio.uio_resid = len; 240 auio.uio_offset = offset; 241 auio.uio_segflg = segflg; 242 auio.uio_rw = rw; 243 auio.uio_procp = p; 244 if (rw == UIO_READ) { 245 error = VOP_READ(vp, &auio, ioflg, cred); 246 } else { 247 error = VOP_WRITE(vp, &auio, ioflg, cred); 248 } 249 if (aresid) 250 *aresid = auio.uio_resid; 251 else 252 if (auio.uio_resid && error == 0) 253 error = EIO; 254 if ((ioflg & IO_NODELOCKED) == 0) 255 VOP_UNLOCK(vp, 0); 256 return (error); 257 } 258 259 int 260 vn_readdir(fp, buf, segflg, count, done, p, cookies, ncookies) 261 struct file *fp; 262 char *buf; 263 int segflg, *done, *ncookies; 264 u_int count; 265 struct proc *p; 266 off_t **cookies; 267 { 268 struct vnode *vp = (struct vnode *)fp->f_data; 269 struct iovec aiov; 270 struct uio auio; 271 int error, eofflag; 272 273 unionread: 274 if (vp->v_type != VDIR) 275 return (EINVAL); 276 aiov.iov_base = buf; 277 aiov.iov_len = count; 278 auio.uio_iov = &aiov; 279 auio.uio_iovcnt = 1; 280 auio.uio_rw = UIO_READ; 281 auio.uio_segflg = segflg; 282 auio.uio_procp = p; 283 auio.uio_resid = count; 284 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 285 auio.uio_offset = fp->f_offset; 286 error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, cookies, 287 ncookies); 288 fp->f_offset = auio.uio_offset; 289 VOP_UNLOCK(vp, 0); 290 if (error) 291 return (error); 292 293 #ifdef UNION 294 { 295 extern int (**union_vnodeop_p) __P((void *)); 296 extern struct vnode *union_dircache __P((struct vnode *)); 297 298 if (count == auio.uio_resid && (vp->v_op == union_vnodeop_p)) { 299 struct vnode *lvp; 300 301 lvp = union_dircache(vp); 302 if (lvp != NULLVP) { 303 struct vattr va; 304 305 /* 306 * If the directory is opaque, 307 * then don't show lower entries 308 */ 309 error = VOP_GETATTR(vp, &va, fp->f_cred, p); 310 if (va.va_flags & OPAQUE) { 311 vput(lvp); 312 lvp = NULL; 313 } 314 } 315 316 if (lvp != NULLVP) { 317 error = VOP_OPEN(lvp, FREAD, fp->f_cred, p); 318 if (error) { 319 vput(lvp); 320 return (error); 321 } 322 VOP_UNLOCK(lvp, 0); 323 fp->f_data = (caddr_t) lvp; 324 fp->f_offset = 0; 325 error = vn_close(vp, FREAD, fp->f_cred, p); 326 if (error) 327 return (error); 328 vp = lvp; 329 goto unionread; 330 } 331 } 332 } 333 #endif /* UNION */ 334 335 if (count == auio.uio_resid && (vp->v_flag & VROOT) && 336 (vp->v_mount->mnt_flag & MNT_UNION)) { 337 struct vnode *tvp = vp; 338 vp = vp->v_mount->mnt_vnodecovered; 339 VREF(vp); 340 fp->f_data = (caddr_t) vp; 341 fp->f_offset = 0; 342 vrele(tvp); 343 goto unionread; 344 } 345 *done = count - auio.uio_resid; 346 return error; 347 } 348 349 /* 350 * File table vnode read routine. 351 */ 352 int 353 vn_read(fp, offset, uio, cred, flags) 354 struct file *fp; 355 off_t *offset; 356 struct uio *uio; 357 struct ucred *cred; 358 int flags; 359 { 360 struct vnode *vp = (struct vnode *)fp->f_data; 361 int count, error, ioflag = 0; 362 363 VOP_LEASE(vp, uio->uio_procp, cred, LEASE_READ); 364 if (fp->f_flag & FNONBLOCK) 365 ioflag |= IO_NDELAY; 366 if ((fp->f_flag & (FFSYNC | FRSYNC)) == (FFSYNC | FRSYNC)) 367 ioflag |= IO_SYNC; 368 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 369 uio->uio_offset = *offset; 370 count = uio->uio_resid; 371 error = VOP_READ(vp, uio, ioflag, cred); 372 if (flags & FOF_UPDATE_OFFSET) 373 *offset += count - uio->uio_resid; 374 VOP_UNLOCK(vp, 0); 375 return (error); 376 } 377 378 /* 379 * File table vnode write routine. 380 */ 381 int 382 vn_write(fp, offset, uio, cred, flags) 383 struct file *fp; 384 off_t *offset; 385 struct uio *uio; 386 struct ucred *cred; 387 int flags; 388 { 389 struct vnode *vp = (struct vnode *)fp->f_data; 390 int count, error, ioflag = IO_UNIT; 391 392 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 393 ioflag |= IO_APPEND; 394 if (fp->f_flag & FNONBLOCK) 395 ioflag |= IO_NDELAY; 396 if (fp->f_flag & FFSYNC || 397 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS))) 398 ioflag |= IO_SYNC; 399 else if (fp->f_flag & FDSYNC) 400 ioflag |= IO_DSYNC; 401 VOP_LEASE(vp, uio->uio_procp, cred, LEASE_WRITE); 402 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 403 uio->uio_offset = *offset; 404 count = uio->uio_resid; 405 error = VOP_WRITE(vp, uio, ioflag, cred); 406 if (flags & FOF_UPDATE_OFFSET) { 407 if (ioflag & IO_APPEND) 408 *offset = uio->uio_offset; 409 else 410 *offset += count - uio->uio_resid; 411 } 412 VOP_UNLOCK(vp, 0); 413 return (error); 414 } 415 416 /* 417 * File table vnode stat routine. 418 */ 419 int 420 vn_stat(vp, sb, p) 421 struct vnode *vp; 422 register struct stat *sb; 423 struct proc *p; 424 { 425 struct vattr va; 426 int error; 427 u_short mode; 428 429 error = VOP_GETATTR(vp, &va, p->p_ucred, p); 430 if (error) 431 return (error); 432 /* 433 * Copy from vattr table 434 */ 435 sb->st_dev = va.va_fsid; 436 sb->st_ino = va.va_fileid; 437 mode = va.va_mode; 438 switch (vp->v_type) { 439 case VREG: 440 mode |= S_IFREG; 441 break; 442 case VDIR: 443 mode |= S_IFDIR; 444 break; 445 case VBLK: 446 mode |= S_IFBLK; 447 break; 448 case VCHR: 449 mode |= S_IFCHR; 450 break; 451 case VLNK: 452 mode |= S_IFLNK; 453 break; 454 case VSOCK: 455 mode |= S_IFSOCK; 456 break; 457 case VFIFO: 458 mode |= S_IFIFO; 459 break; 460 default: 461 return (EBADF); 462 }; 463 sb->st_mode = mode; 464 sb->st_nlink = va.va_nlink; 465 sb->st_uid = va.va_uid; 466 sb->st_gid = va.va_gid; 467 sb->st_rdev = va.va_rdev; 468 sb->st_size = va.va_size; 469 sb->st_atimespec = va.va_atime; 470 sb->st_mtimespec = va.va_mtime; 471 sb->st_ctimespec = va.va_ctime; 472 sb->st_blksize = va.va_blocksize; 473 sb->st_flags = va.va_flags; 474 sb->st_gen = 0; 475 sb->st_blocks = va.va_bytes / S_BLKSIZE; 476 return (0); 477 } 478 479 /* 480 * File table vnode ioctl routine. 481 */ 482 int 483 vn_ioctl(fp, com, data, p) 484 struct file *fp; 485 u_long com; 486 caddr_t data; 487 struct proc *p; 488 { 489 register struct vnode *vp = ((struct vnode *)fp->f_data); 490 struct vattr vattr; 491 int error; 492 493 switch (vp->v_type) { 494 495 case VREG: 496 case VDIR: 497 if (com == FIONREAD) { 498 error = VOP_GETATTR(vp, &vattr, p->p_ucred, p); 499 if (error) 500 return (error); 501 *(int *)data = vattr.va_size - fp->f_offset; 502 return (0); 503 } 504 if (com == FIONBIO || com == FIOASYNC) /* XXX */ 505 return (0); /* XXX */ 506 /* fall into ... */ 507 508 default: 509 return (ENOTTY); 510 511 case VFIFO: 512 case VCHR: 513 case VBLK: 514 error = VOP_IOCTL(vp, com, data, fp->f_flag, p->p_ucred, p); 515 if (error == 0 && com == TIOCSCTTY) { 516 if (p->p_session->s_ttyvp) 517 vrele(p->p_session->s_ttyvp); 518 p->p_session->s_ttyvp = vp; 519 VREF(vp); 520 } 521 return (error); 522 } 523 } 524 525 /* 526 * File table vnode poll routine. 527 */ 528 int 529 vn_poll(fp, events, p) 530 struct file *fp; 531 int events; 532 struct proc *p; 533 { 534 535 return (VOP_POLL(((struct vnode *)fp->f_data), events, p)); 536 } 537 538 /* 539 * Check that the vnode is still valid, and if so 540 * acquire requested lock. 541 */ 542 int 543 vn_lock(vp, flags) 544 struct vnode *vp; 545 int flags; 546 { 547 int error; 548 549 do { 550 if ((flags & LK_INTERLOCK) == 0) 551 simple_lock(&vp->v_interlock); 552 if (vp->v_flag & VXLOCK) { 553 vp->v_flag |= VXWANT; 554 simple_unlock(&vp->v_interlock); 555 tsleep((caddr_t)vp, PINOD, "vn_lock", 0); 556 error = ENOENT; 557 } else { 558 error = VOP_LOCK(vp, flags | LK_INTERLOCK); 559 if (error == 0) 560 return (error); 561 } 562 flags &= ~LK_INTERLOCK; 563 } while (flags & LK_RETRY); 564 return (error); 565 } 566 567 /* 568 * File table vnode close routine. 569 */ 570 int 571 vn_closefile(fp, p) 572 struct file *fp; 573 struct proc *p; 574 { 575 576 return (vn_close(((struct vnode *)fp->f_data), fp->f_flag, 577 fp->f_cred, p)); 578 } 579
Indexes created Sat Sep 20 22:09:52 GMT 2025