vfs_vnops.c revision 1.31.2.1
1 /* $NetBSD: vfs_vnops.c,v 1.31.2.1 1998/11/09 06:06:33 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 #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++; 161 162 #ifdef UBC 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 #endif 169 return (0); 170 bad: 171 vput(vp); 172 return (error); 173 } 174 175 /* 176 * Check for write permissions on the specified vnode. 177 * Prototype text segments cannot be written. 178 */ 179 int 180 vn_writechk(vp) 181 register struct vnode *vp; 182 { 183 184 /* 185 * If there's shared text associated with 186 * the vnode, try to free it up once. If 187 * we fail, we can't allow writing. 188 */ 189 #if defined(UVM) 190 if ((vp->v_flag & VTEXT) && !uvm_vnp_uncache(vp)) 191 return (ETXTBSY); 192 #else 193 if ((vp->v_flag & VTEXT) && !vnode_pager_uncache(vp)) 194 return (ETXTBSY); 195 #endif 196 return (0); 197 } 198 199 /* 200 * Vnode close call 201 */ 202 int 203 vn_close(vp, flags, cred, p) 204 register struct vnode *vp; 205 int flags; 206 struct ucred *cred; 207 struct proc *p; 208 { 209 int error; 210 211 if (flags & FWRITE) 212 vp->v_writecount--; 213 error = VOP_CLOSE(vp, flags, cred, p); 214 vrele(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 int (**union_vnodeop_p) __P((void *)); 301 extern struct vnode *union_dircache __P((struct vnode *)); 302 303 if (count == auio.uio_resid && (vp->v_op == union_vnodeop_p)) { 304 struct vnode *lvp; 305 306 lvp = union_dircache(vp); 307 if (lvp != NULLVP) { 308 struct vattr va; 309 310 /* 311 * If the directory is opaque, 312 * then don't show lower entries 313 */ 314 error = VOP_GETATTR(vp, &va, fp->f_cred, p); 315 if (va.va_flags & OPAQUE) { 316 vput(lvp); 317 lvp = NULL; 318 } 319 } 320 321 if (lvp != NULLVP) { 322 error = VOP_OPEN(lvp, FREAD, fp->f_cred, p); 323 if (error) { 324 vput(lvp); 325 return (error); 326 } 327 VOP_UNLOCK(lvp, 0); 328 fp->f_data = (caddr_t) lvp; 329 fp->f_offset = 0; 330 error = vn_close(vp, FREAD, fp->f_cred, p); 331 if (error) 332 return (error); 333 vp = lvp; 334 goto unionread; 335 } 336 } 337 } 338 #endif /* UNION */ 339 340 if (count == auio.uio_resid && (vp->v_flag & VROOT) && 341 (vp->v_mount->mnt_flag & MNT_UNION)) { 342 struct vnode *tvp = vp; 343 vp = vp->v_mount->mnt_vnodecovered; 344 VREF(vp); 345 fp->f_data = (caddr_t) vp; 346 fp->f_offset = 0; 347 vrele(tvp); 348 goto unionread; 349 } 350 *done = count - auio.uio_resid; 351 return error; 352 } 353 354 /* 355 * File table vnode read routine. 356 */ 357 int 358 vn_read(fp, offset, uio, cred, flags) 359 struct file *fp; 360 off_t *offset; 361 struct uio *uio; 362 struct ucred *cred; 363 int flags; 364 { 365 struct vnode *vp = (struct vnode *)fp->f_data; 366 int count, error, ioflag = 0; 367 368 VOP_LEASE(vp, uio->uio_procp, cred, LEASE_READ); 369 if (fp->f_flag & FNONBLOCK) 370 ioflag |= IO_NDELAY; 371 if ((fp->f_flag & (FFSYNC | FRSYNC)) == (FFSYNC | FRSYNC)) 372 ioflag |= IO_SYNC; 373 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 374 uio->uio_offset = *offset; 375 count = uio->uio_resid; 376 error = VOP_READ(vp, uio, ioflag, cred); 377 if (flags & FOF_UPDATE_OFFSET) 378 *offset += count - uio->uio_resid; 379 VOP_UNLOCK(vp, 0); 380 return (error); 381 } 382 383 /* 384 * File table vnode write routine. 385 */ 386 int 387 vn_write(fp, offset, uio, cred, flags) 388 struct file *fp; 389 off_t *offset; 390 struct uio *uio; 391 struct ucred *cred; 392 int flags; 393 { 394 struct vnode *vp = (struct vnode *)fp->f_data; 395 int count, error, ioflag = IO_UNIT; 396 397 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 398 ioflag |= IO_APPEND; 399 if (fp->f_flag & FNONBLOCK) 400 ioflag |= IO_NDELAY; 401 if (fp->f_flag & FFSYNC || 402 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS))) 403 ioflag |= IO_SYNC; 404 else if (fp->f_flag & FDSYNC) 405 ioflag |= IO_DSYNC; 406 VOP_LEASE(vp, uio->uio_procp, cred, LEASE_WRITE); 407 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 408 uio->uio_offset = *offset; 409 count = uio->uio_resid; 410 error = VOP_WRITE(vp, uio, ioflag, cred); 411 if (flags & FOF_UPDATE_OFFSET) { 412 if (ioflag & IO_APPEND) 413 *offset = uio->uio_offset; 414 else 415 *offset += count - uio->uio_resid; 416 } 417 VOP_UNLOCK(vp, 0); 418 return (error); 419 } 420 421 /* 422 * File table vnode stat routine. 423 */ 424 int 425 vn_stat(vp, sb, p) 426 struct vnode *vp; 427 register struct stat *sb; 428 struct proc *p; 429 { 430 struct vattr va; 431 int error; 432 u_short mode; 433 434 error = VOP_GETATTR(vp, &va, p->p_ucred, p); 435 if (error) 436 return (error); 437 /* 438 * Copy from vattr table 439 */ 440 sb->st_dev = va.va_fsid; 441 sb->st_ino = va.va_fileid; 442 mode = va.va_mode; 443 switch (vp->v_type) { 444 case VREG: 445 mode |= S_IFREG; 446 break; 447 case VDIR: 448 mode |= S_IFDIR; 449 break; 450 case VBLK: 451 mode |= S_IFBLK; 452 break; 453 case VCHR: 454 mode |= S_IFCHR; 455 break; 456 case VLNK: 457 mode |= S_IFLNK; 458 break; 459 case VSOCK: 460 mode |= S_IFSOCK; 461 break; 462 case VFIFO: 463 mode |= S_IFIFO; 464 break; 465 default: 466 return (EBADF); 467 }; 468 sb->st_mode = mode; 469 sb->st_nlink = va.va_nlink; 470 sb->st_uid = va.va_uid; 471 sb->st_gid = va.va_gid; 472 sb->st_rdev = va.va_rdev; 473 sb->st_size = va.va_size; 474 sb->st_atimespec = va.va_atime; 475 sb->st_mtimespec = va.va_mtime; 476 sb->st_ctimespec = va.va_ctime; 477 sb->st_blksize = va.va_blocksize; 478 sb->st_flags = va.va_flags; 479 sb->st_gen = 0; 480 sb->st_blocks = va.va_bytes / S_BLKSIZE; 481 return (0); 482 } 483 484 /* 485 * File table vnode ioctl routine. 486 */ 487 int 488 vn_ioctl(fp, com, data, p) 489 struct file *fp; 490 u_long com; 491 caddr_t data; 492 struct proc *p; 493 { 494 register struct vnode *vp = ((struct vnode *)fp->f_data); 495 struct vattr vattr; 496 int error; 497 498 switch (vp->v_type) { 499 500 case VREG: 501 case VDIR: 502 if (com == FIONREAD) { 503 error = VOP_GETATTR(vp, &vattr, p->p_ucred, p); 504 if (error) 505 return (error); 506 *(int *)data = vattr.va_size - fp->f_offset; 507 return (0); 508 } 509 if (com == FIONBIO || com == FIOASYNC) /* XXX */ 510 return (0); /* XXX */ 511 /* fall into ... */ 512 513 default: 514 return (ENOTTY); 515 516 case VFIFO: 517 case VCHR: 518 case VBLK: 519 error = VOP_IOCTL(vp, com, data, fp->f_flag, p->p_ucred, p); 520 if (error == 0 && com == TIOCSCTTY) { 521 if (p->p_session->s_ttyvp) 522 vrele(p->p_session->s_ttyvp); 523 p->p_session->s_ttyvp = vp; 524 VREF(vp); 525 } 526 return (error); 527 } 528 } 529 530 /* 531 * File table vnode poll routine. 532 */ 533 int 534 vn_poll(fp, events, p) 535 struct file *fp; 536 int events; 537 struct proc *p; 538 { 539 540 return (VOP_POLL(((struct vnode *)fp->f_data), events, p)); 541 } 542 543 /* 544 * Check that the vnode is still valid, and if so 545 * acquire requested lock. 546 */ 547 int 548 vn_lock(vp, flags) 549 struct vnode *vp; 550 int flags; 551 { 552 int error; 553 554 do { 555 if ((flags & LK_INTERLOCK) == 0) 556 simple_lock(&vp->v_interlock); 557 if (vp->v_flag & VXLOCK) { 558 vp->v_flag |= VXWANT; 559 simple_unlock(&vp->v_interlock); 560 tsleep((caddr_t)vp, PINOD, "vn_lock", 0); 561 error = ENOENT; 562 } else { 563 error = VOP_LOCK(vp, flags | LK_INTERLOCK); 564 if (error == 0) 565 return (error); 566 } 567 flags &= ~LK_INTERLOCK; 568 } while (flags & LK_RETRY); 569 return (error); 570 } 571 572 /* 573 * File table vnode close routine. 574 */ 575 int 576 vn_closefile(fp, p) 577 struct file *fp; 578 struct proc *p; 579 { 580 581 return (vn_close(((struct vnode *)fp->f_data), fp->f_flag, 582 fp->f_cred, p)); 583 } 584
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