vfs_vnops.c revision 1.25
1 /* $NetBSD: vfs_vnops.c,v 1.25 1998/02/05 08:00:07 mrg 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 8.5 (Berkeley) 12/8/94 41 */ 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/kernel.h> 46 #include <sys/file.h> 47 #include <sys/stat.h> 48 #include <sys/buf.h> 49 #include <sys/proc.h> 50 #include <sys/mount.h> 51 #include <sys/namei.h> 52 #include <sys/vnode.h> 53 #include <sys/ioctl.h> 54 #include <sys/tty.h> 55 #include <sys/poll.h> 56 57 #include <vm/vm.h> 58 59 #if defined(UVM) 60 #include <uvm/uvm_extern.h> 61 #endif 62 63 struct fileops vnops = 64 { vn_read, vn_write, vn_ioctl, vn_poll, vn_closefile }; 65 66 /* 67 * Common code for vnode open operations. 68 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine. 69 */ 70 int 71 vn_open(ndp, fmode, cmode) 72 register struct nameidata *ndp; 73 int fmode, cmode; 74 { 75 register struct vnode *vp; 76 register struct proc *p = ndp->ni_cnd.cn_proc; 77 register struct ucred *cred = p->p_ucred; 78 struct vattr va; 79 int error; 80 81 if (fmode & O_CREAT) { 82 ndp->ni_cnd.cn_nameiop = CREATE; 83 ndp->ni_cnd.cn_flags = LOCKPARENT | LOCKLEAF; 84 if ((fmode & O_EXCL) == 0) 85 ndp->ni_cnd.cn_flags |= FOLLOW; 86 if ((error = namei(ndp)) != 0) 87 return (error); 88 if (ndp->ni_vp == NULL) { 89 VATTR_NULL(&va); 90 va.va_type = VREG; 91 va.va_mode = cmode; 92 VOP_LEASE(ndp->ni_dvp, p, cred, LEASE_WRITE); 93 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp, 94 &ndp->ni_cnd, &va); 95 if (error) 96 return (error); 97 fmode &= ~O_TRUNC; 98 vp = ndp->ni_vp; 99 } else { 100 VOP_ABORTOP(ndp->ni_dvp, &ndp->ni_cnd); 101 if (ndp->ni_dvp == ndp->ni_vp) 102 vrele(ndp->ni_dvp); 103 else 104 vput(ndp->ni_dvp); 105 ndp->ni_dvp = NULL; 106 vp = ndp->ni_vp; 107 if (fmode & O_EXCL) { 108 error = EEXIST; 109 goto bad; 110 } 111 fmode &= ~O_CREAT; 112 } 113 } else { 114 ndp->ni_cnd.cn_nameiop = LOOKUP; 115 ndp->ni_cnd.cn_flags = FOLLOW | LOCKLEAF; 116 if ((error = namei(ndp)) != 0) 117 return (error); 118 vp = ndp->ni_vp; 119 } 120 if (vp->v_type == VSOCK) { 121 error = EOPNOTSUPP; 122 goto bad; 123 } 124 if ((fmode & O_CREAT) == 0) { 125 if (fmode & FREAD) { 126 if ((error = VOP_ACCESS(vp, VREAD, cred, p)) != 0) 127 goto bad; 128 } 129 if (fmode & (FWRITE | O_TRUNC)) { 130 if (vp->v_type == VDIR) { 131 error = EISDIR; 132 goto bad; 133 } 134 if ((error = vn_writechk(vp)) != 0 || 135 (error = VOP_ACCESS(vp, VWRITE, cred, p)) != 0) 136 goto bad; 137 } 138 } 139 if (fmode & O_TRUNC) { 140 VOP_UNLOCK(vp); /* XXX */ 141 VOP_LEASE(vp, p, cred, LEASE_WRITE); 142 VOP_LOCK(vp); /* XXX */ 143 VATTR_NULL(&va); 144 va.va_size = 0; 145 if ((error = VOP_SETATTR(vp, &va, cred, p)) != 0) 146 goto bad; 147 } 148 if ((error = VOP_OPEN(vp, fmode, cred, p)) != 0) 149 goto bad; 150 if (fmode & FWRITE) 151 vp->v_writecount++; 152 return (0); 153 bad: 154 vput(vp); 155 return (error); 156 } 157 158 /* 159 * Check for write permissions on the specified vnode. 160 * The read-only status of the file system is checked. 161 * Also, prototype text segments cannot be written. 162 */ 163 int 164 vn_writechk(vp) 165 register struct vnode *vp; 166 { 167 168 /* 169 * Disallow write attempts on read-only file systems; 170 * unless the file is a socket or a block or character 171 * device resident on the file system. 172 */ 173 if (vp->v_mount->mnt_flag & MNT_RDONLY) { 174 switch (vp->v_type) { 175 case VREG: case VDIR: case VLNK: 176 return (EROFS); 177 case VNON: case VCHR: case VSOCK: 178 case VFIFO: case VBAD: case VBLK: 179 break; 180 } 181 } 182 /* 183 * If there's shared text associated with 184 * the vnode, try to free it up once. If 185 * we fail, we can't allow writing. 186 */ 187 #if defined(UVM) 188 if ((vp->v_flag & VTEXT) && !uvm_vnp_uncache(vp)) 189 return (ETXTBSY); 190 #else 191 if ((vp->v_flag & VTEXT) && !vnode_pager_uncache(vp)) 192 return (ETXTBSY); 193 #endif 194 return (0); 195 } 196 197 /* 198 * Vnode close call 199 */ 200 int 201 vn_close(vp, flags, cred, p) 202 register struct vnode *vp; 203 int flags; 204 struct ucred *cred; 205 struct proc *p; 206 { 207 int error; 208 209 if (flags & FWRITE) 210 vp->v_writecount--; 211 error = VOP_CLOSE(vp, flags, cred, p); 212 vrele(vp); 213 return (error); 214 } 215 216 /* 217 * Package up an I/O request on a vnode into a uio and do it. 218 */ 219 int 220 vn_rdwr(rw, vp, base, len, offset, segflg, ioflg, cred, aresid, p) 221 enum uio_rw rw; 222 struct vnode *vp; 223 caddr_t base; 224 int len; 225 off_t offset; 226 enum uio_seg segflg; 227 int ioflg; 228 struct ucred *cred; 229 int *aresid; 230 struct proc *p; 231 { 232 struct uio auio; 233 struct iovec aiov; 234 int error; 235 236 if ((ioflg & IO_NODELOCKED) == 0) 237 VOP_LOCK(vp); 238 auio.uio_iov = &aiov; 239 auio.uio_iovcnt = 1; 240 aiov.iov_base = base; 241 aiov.iov_len = len; 242 auio.uio_resid = len; 243 auio.uio_offset = offset; 244 auio.uio_segflg = segflg; 245 auio.uio_rw = rw; 246 auio.uio_procp = p; 247 if (rw == UIO_READ) { 248 error = VOP_READ(vp, &auio, ioflg, cred); 249 } else { 250 error = VOP_WRITE(vp, &auio, ioflg, cred); 251 } 252 if (aresid) 253 *aresid = auio.uio_resid; 254 else 255 if (auio.uio_resid && error == 0) 256 error = EIO; 257 if ((ioflg & IO_NODELOCKED) == 0) 258 VOP_UNLOCK(vp); 259 return (error); 260 } 261 262 int 263 vn_readdir(fp, buf, segflg, count, done, p, cookies, ncookies) 264 struct file *fp; 265 char *buf; 266 int segflg, *done, ncookies; 267 u_int count; 268 struct proc *p; 269 off_t *cookies; 270 { 271 struct vnode *vp = (struct vnode *)fp->f_data; 272 struct iovec aiov; 273 struct uio auio; 274 int error, eofflag; 275 276 unionread: 277 if (vp->v_type != VDIR) 278 return (EINVAL); 279 aiov.iov_base = buf; 280 aiov.iov_len = count; 281 auio.uio_iov = &aiov; 282 auio.uio_iovcnt = 1; 283 auio.uio_rw = UIO_READ; 284 auio.uio_segflg = segflg; 285 auio.uio_procp = p; 286 auio.uio_resid = count; 287 VOP_LOCK(vp); 288 auio.uio_offset = fp->f_offset; 289 error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, (off_t *)cookies, 290 ncookies); 291 fp->f_offset = auio.uio_offset; 292 VOP_UNLOCK(vp); 293 if (error) 294 return (error); 295 296 #ifdef UNION 297 { 298 extern int (**union_vnodeop_p) __P((void *)); 299 extern struct vnode *union_dircache __P((struct vnode *)); 300 301 if (count == auio.uio_resid && (vp->v_op == union_vnodeop_p)) { 302 struct vnode *lvp; 303 304 lvp = union_dircache(vp); 305 if (lvp != NULLVP) { 306 struct vattr va; 307 308 /* 309 * If the directory is opaque, 310 * then don't show lower entries 311 */ 312 error = VOP_GETATTR(vp, &va, fp->f_cred, p); 313 if (va.va_flags & OPAQUE) { 314 vput(lvp); 315 lvp = NULL; 316 } 317 } 318 319 if (lvp != NULLVP) { 320 error = VOP_OPEN(lvp, FREAD, fp->f_cred, p); 321 VOP_UNLOCK(lvp); 322 323 if (error) { 324 vrele(lvp); 325 return (error); 326 } 327 fp->f_data = (caddr_t) lvp; 328 fp->f_offset = 0; 329 error = vn_close(vp, FREAD, fp->f_cred, p); 330 if (error) 331 return (error); 332 vp = lvp; 333 goto unionread; 334 } 335 } 336 } 337 #endif /* UNION */ 338 339 if (count == auio.uio_resid && (vp->v_flag & VROOT) && 340 (vp->v_mount->mnt_flag & MNT_UNION)) { 341 struct vnode *tvp = vp; 342 vp = vp->v_mount->mnt_vnodecovered; 343 VREF(vp); 344 fp->f_data = (caddr_t) vp; 345 fp->f_offset = 0; 346 vrele(tvp); 347 goto unionread; 348 } 349 *done = count - auio.uio_resid; 350 return error; 351 } 352 353 /* 354 * File table vnode read routine. 355 */ 356 int 357 vn_read(fp, uio, cred) 358 struct file *fp; 359 struct uio *uio; 360 struct ucred *cred; 361 { 362 register struct vnode *vp = (struct vnode *)fp->f_data; 363 int count, error; 364 365 VOP_LEASE(vp, uio->uio_procp, cred, LEASE_READ); 366 VOP_LOCK(vp); 367 uio->uio_offset = fp->f_offset; 368 count = uio->uio_resid; 369 error = VOP_READ(vp, uio, (fp->f_flag & FNONBLOCK) ? IO_NDELAY : 0, 370 cred); 371 fp->f_offset += count - uio->uio_resid; 372 VOP_UNLOCK(vp); 373 return (error); 374 } 375 376 /* 377 * File table vnode write routine. 378 */ 379 int 380 vn_write(fp, uio, cred) 381 struct file *fp; 382 struct uio *uio; 383 struct ucred *cred; 384 { 385 register struct vnode *vp = (struct vnode *)fp->f_data; 386 int count, error, ioflag = IO_UNIT; 387 388 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 389 ioflag |= IO_APPEND; 390 if (fp->f_flag & FNONBLOCK) 391 ioflag |= IO_NDELAY; 392 if (fp->f_flag & FFSYNC || 393 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS))) 394 ioflag |= IO_SYNC; 395 VOP_LEASE(vp, uio->uio_procp, cred, LEASE_WRITE); 396 VOP_LOCK(vp); 397 uio->uio_offset = fp->f_offset; 398 count = uio->uio_resid; 399 error = VOP_WRITE(vp, uio, ioflag, cred); 400 if (ioflag & IO_APPEND) 401 fp->f_offset = uio->uio_offset; 402 else 403 fp->f_offset += count - uio->uio_resid; 404 VOP_UNLOCK(vp); 405 return (error); 406 } 407 408 /* 409 * File table vnode stat routine. 410 */ 411 int 412 vn_stat(vp, sb, p) 413 struct vnode *vp; 414 register struct stat *sb; 415 struct proc *p; 416 { 417 struct vattr va; 418 int error; 419 u_short mode; 420 421 error = VOP_GETATTR(vp, &va, p->p_ucred, p); 422 if (error) 423 return (error); 424 /* 425 * Copy from vattr table 426 */ 427 sb->st_dev = va.va_fsid; 428 sb->st_ino = va.va_fileid; 429 mode = va.va_mode; 430 switch (vp->v_type) { 431 case VREG: 432 mode |= S_IFREG; 433 break; 434 case VDIR: 435 mode |= S_IFDIR; 436 break; 437 case VBLK: 438 mode |= S_IFBLK; 439 break; 440 case VCHR: 441 mode |= S_IFCHR; 442 break; 443 case VLNK: 444 mode |= S_IFLNK; 445 break; 446 case VSOCK: 447 mode |= S_IFSOCK; 448 break; 449 case VFIFO: 450 mode |= S_IFIFO; 451 break; 452 default: 453 return (EBADF); 454 }; 455 sb->st_mode = mode; 456 sb->st_nlink = va.va_nlink; 457 sb->st_uid = va.va_uid; 458 sb->st_gid = va.va_gid; 459 sb->st_rdev = va.va_rdev; 460 sb->st_size = va.va_size; 461 sb->st_atimespec = va.va_atime; 462 sb->st_mtimespec = va.va_mtime; 463 sb->st_ctimespec = va.va_ctime; 464 sb->st_blksize = va.va_blocksize; 465 sb->st_flags = va.va_flags; 466 sb->st_gen = 0; 467 sb->st_blocks = va.va_bytes / S_BLKSIZE; 468 return (0); 469 } 470 471 /* 472 * File table vnode ioctl routine. 473 */ 474 int 475 vn_ioctl(fp, com, data, p) 476 struct file *fp; 477 u_long com; 478 caddr_t data; 479 struct proc *p; 480 { 481 register struct vnode *vp = ((struct vnode *)fp->f_data); 482 struct vattr vattr; 483 int error; 484 485 switch (vp->v_type) { 486 487 case VREG: 488 case VDIR: 489 if (com == FIONREAD) { 490 error = VOP_GETATTR(vp, &vattr, p->p_ucred, p); 491 if (error) 492 return (error); 493 *(int *)data = vattr.va_size - fp->f_offset; 494 return (0); 495 } 496 if (com == FIONBIO || com == FIOASYNC) /* XXX */ 497 return (0); /* XXX */ 498 /* fall into ... */ 499 500 default: 501 return (ENOTTY); 502 503 case VFIFO: 504 case VCHR: 505 case VBLK: 506 error = VOP_IOCTL(vp, com, data, fp->f_flag, p->p_ucred, p); 507 if (error == 0 && com == TIOCSCTTY) { 508 if (p->p_session->s_ttyvp) 509 vrele(p->p_session->s_ttyvp); 510 p->p_session->s_ttyvp = vp; 511 VREF(vp); 512 } 513 return (error); 514 } 515 } 516 517 /* 518 * File table vnode poll routine. 519 */ 520 int 521 vn_poll(fp, events, p) 522 struct file *fp; 523 int events; 524 struct proc *p; 525 { 526 527 return (VOP_POLL(((struct vnode *)fp->f_data), events, p)); 528 } 529 530 /* 531 * File table vnode close routine. 532 */ 533 int 534 vn_closefile(fp, p) 535 struct file *fp; 536 struct proc *p; 537 { 538 539 return (vn_close(((struct vnode *)fp->f_data), fp->f_flag, 540 fp->f_cred, p)); 541 } 542
Indexes created Sat Sep 20 22:09:52 GMT 2025