vfs_vnops.c revision 1.27
1 /* $NetBSD: vfs_vnops.c,v 1.27 1998/02/19 00:53:46 thorpej 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 "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 struct fileops vnops = 67 { vn_read, vn_write, vn_ioctl, vn_poll, vn_closefile }; 68 69 /* 70 * Common code for vnode open operations. 71 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine. 72 */ 73 int 74 vn_open(ndp, fmode, cmode) 75 register struct nameidata *ndp; 76 int fmode, cmode; 77 { 78 register struct vnode *vp; 79 register struct proc *p = ndp->ni_cnd.cn_proc; 80 register struct ucred *cred = p->p_ucred; 81 struct vattr va; 82 int error; 83 84 if (fmode & O_CREAT) { 85 ndp->ni_cnd.cn_nameiop = CREATE; 86 ndp->ni_cnd.cn_flags = LOCKPARENT | LOCKLEAF; 87 if ((fmode & O_EXCL) == 0) 88 ndp->ni_cnd.cn_flags |= FOLLOW; 89 if ((error = namei(ndp)) != 0) 90 return (error); 91 if (ndp->ni_vp == NULL) { 92 VATTR_NULL(&va); 93 va.va_type = VREG; 94 va.va_mode = cmode; 95 VOP_LEASE(ndp->ni_dvp, p, cred, LEASE_WRITE); 96 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp, 97 &ndp->ni_cnd, &va); 98 if (error) 99 return (error); 100 fmode &= ~O_TRUNC; 101 vp = ndp->ni_vp; 102 } else { 103 VOP_ABORTOP(ndp->ni_dvp, &ndp->ni_cnd); 104 if (ndp->ni_dvp == ndp->ni_vp) 105 vrele(ndp->ni_dvp); 106 else 107 vput(ndp->ni_dvp); 108 ndp->ni_dvp = NULL; 109 vp = ndp->ni_vp; 110 if (fmode & O_EXCL) { 111 error = EEXIST; 112 goto bad; 113 } 114 fmode &= ~O_CREAT; 115 } 116 } else { 117 ndp->ni_cnd.cn_nameiop = LOOKUP; 118 ndp->ni_cnd.cn_flags = FOLLOW | LOCKLEAF; 119 if ((error = namei(ndp)) != 0) 120 return (error); 121 vp = ndp->ni_vp; 122 } 123 if (vp->v_type == VSOCK) { 124 error = EOPNOTSUPP; 125 goto bad; 126 } 127 if ((fmode & O_CREAT) == 0) { 128 if (fmode & FREAD) { 129 if ((error = VOP_ACCESS(vp, VREAD, cred, p)) != 0) 130 goto bad; 131 } 132 if (fmode & (FWRITE | O_TRUNC)) { 133 if (vp->v_type == VDIR) { 134 error = EISDIR; 135 goto bad; 136 } 137 if ((error = vn_writechk(vp)) != 0 || 138 (error = VOP_ACCESS(vp, VWRITE, cred, p)) != 0) 139 goto bad; 140 } 141 } 142 if (fmode & O_TRUNC) { 143 VOP_UNLOCK(vp); /* XXX */ 144 VOP_LEASE(vp, p, cred, LEASE_WRITE); 145 VOP_LOCK(vp); /* XXX */ 146 VATTR_NULL(&va); 147 va.va_size = 0; 148 if ((error = VOP_SETATTR(vp, &va, cred, p)) != 0) 149 goto bad; 150 } 151 if ((error = VOP_OPEN(vp, fmode, cred, p)) != 0) 152 goto bad; 153 if (fmode & FWRITE) 154 vp->v_writecount++; 155 return (0); 156 bad: 157 vput(vp); 158 return (error); 159 } 160 161 /* 162 * Check for write permissions on the specified vnode. 163 * The read-only status of the file system is checked. 164 * Also, prototype text segments cannot be written. 165 */ 166 int 167 vn_writechk(vp) 168 register struct vnode *vp; 169 { 170 171 /* 172 * Disallow write attempts on read-only file systems; 173 * unless the file is a socket or a block or character 174 * device resident on the file system. 175 */ 176 if (vp->v_mount->mnt_flag & MNT_RDONLY) { 177 switch (vp->v_type) { 178 case VREG: case VDIR: case VLNK: 179 return (EROFS); 180 case VNON: case VCHR: case VSOCK: 181 case VFIFO: case VBAD: case VBLK: 182 break; 183 } 184 } 185 /* 186 * If there's shared text associated with 187 * the vnode, try to free it up once. If 188 * we fail, we can't allow writing. 189 */ 190 #if defined(UVM) 191 if ((vp->v_flag & VTEXT) && !uvm_vnp_uncache(vp)) 192 return (ETXTBSY); 193 #else 194 if ((vp->v_flag & VTEXT) && !vnode_pager_uncache(vp)) 195 return (ETXTBSY); 196 #endif 197 return (0); 198 } 199 200 /* 201 * Vnode close call 202 */ 203 int 204 vn_close(vp, flags, cred, p) 205 register struct vnode *vp; 206 int flags; 207 struct ucred *cred; 208 struct proc *p; 209 { 210 int error; 211 212 if (flags & FWRITE) 213 vp->v_writecount--; 214 error = VOP_CLOSE(vp, flags, cred, p); 215 vrele(vp); 216 return (error); 217 } 218 219 /* 220 * Package up an I/O request on a vnode into a uio and do it. 221 */ 222 int 223 vn_rdwr(rw, vp, base, len, offset, segflg, ioflg, cred, aresid, p) 224 enum uio_rw rw; 225 struct vnode *vp; 226 caddr_t base; 227 int len; 228 off_t offset; 229 enum uio_seg segflg; 230 int ioflg; 231 struct ucred *cred; 232 int *aresid; 233 struct proc *p; 234 { 235 struct uio auio; 236 struct iovec aiov; 237 int error; 238 239 if ((ioflg & IO_NODELOCKED) == 0) 240 VOP_LOCK(vp); 241 auio.uio_iov = &aiov; 242 auio.uio_iovcnt = 1; 243 aiov.iov_base = base; 244 aiov.iov_len = len; 245 auio.uio_resid = len; 246 auio.uio_offset = offset; 247 auio.uio_segflg = segflg; 248 auio.uio_rw = rw; 249 auio.uio_procp = p; 250 if (rw == UIO_READ) { 251 error = VOP_READ(vp, &auio, ioflg, cred); 252 } else { 253 error = VOP_WRITE(vp, &auio, ioflg, cred); 254 } 255 if (aresid) 256 *aresid = auio.uio_resid; 257 else 258 if (auio.uio_resid && error == 0) 259 error = EIO; 260 if ((ioflg & IO_NODELOCKED) == 0) 261 VOP_UNLOCK(vp); 262 return (error); 263 } 264 265 int 266 vn_readdir(fp, buf, segflg, count, done, p, cookies, ncookies) 267 struct file *fp; 268 char *buf; 269 int segflg, *done, ncookies; 270 u_int count; 271 struct proc *p; 272 off_t *cookies; 273 { 274 struct vnode *vp = (struct vnode *)fp->f_data; 275 struct iovec aiov; 276 struct uio auio; 277 int error, eofflag; 278 279 unionread: 280 if (vp->v_type != VDIR) 281 return (EINVAL); 282 aiov.iov_base = buf; 283 aiov.iov_len = count; 284 auio.uio_iov = &aiov; 285 auio.uio_iovcnt = 1; 286 auio.uio_rw = UIO_READ; 287 auio.uio_segflg = segflg; 288 auio.uio_procp = p; 289 auio.uio_resid = count; 290 VOP_LOCK(vp); 291 auio.uio_offset = fp->f_offset; 292 error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, (off_t *)cookies, 293 ncookies); 294 fp->f_offset = auio.uio_offset; 295 VOP_UNLOCK(vp); 296 if (error) 297 return (error); 298 299 #ifdef UNION 300 { 301 extern int (**union_vnodeop_p) __P((void *)); 302 extern struct vnode *union_dircache __P((struct vnode *)); 303 304 if (count == auio.uio_resid && (vp->v_op == union_vnodeop_p)) { 305 struct vnode *lvp; 306 307 lvp = union_dircache(vp); 308 if (lvp != NULLVP) { 309 struct vattr va; 310 311 /* 312 * If the directory is opaque, 313 * then don't show lower entries 314 */ 315 error = VOP_GETATTR(vp, &va, fp->f_cred, p); 316 if (va.va_flags & OPAQUE) { 317 vput(lvp); 318 lvp = NULL; 319 } 320 } 321 322 if (lvp != NULLVP) { 323 error = VOP_OPEN(lvp, FREAD, fp->f_cred, p); 324 VOP_UNLOCK(lvp); 325 326 if (error) { 327 vrele(lvp); 328 return (error); 329 } 330 fp->f_data = (caddr_t) lvp; 331 fp->f_offset = 0; 332 error = vn_close(vp, FREAD, fp->f_cred, p); 333 if (error) 334 return (error); 335 vp = lvp; 336 goto unionread; 337 } 338 } 339 } 340 #endif /* UNION */ 341 342 if (count == auio.uio_resid && (vp->v_flag & VROOT) && 343 (vp->v_mount->mnt_flag & MNT_UNION)) { 344 struct vnode *tvp = vp; 345 vp = vp->v_mount->mnt_vnodecovered; 346 VREF(vp); 347 fp->f_data = (caddr_t) vp; 348 fp->f_offset = 0; 349 vrele(tvp); 350 goto unionread; 351 } 352 *done = count - auio.uio_resid; 353 return error; 354 } 355 356 /* 357 * File table vnode read routine. 358 */ 359 int 360 vn_read(fp, uio, cred) 361 struct file *fp; 362 struct uio *uio; 363 struct ucred *cred; 364 { 365 register struct vnode *vp = (struct vnode *)fp->f_data; 366 int count, error; 367 368 VOP_LEASE(vp, uio->uio_procp, cred, LEASE_READ); 369 VOP_LOCK(vp); 370 uio->uio_offset = fp->f_offset; 371 count = uio->uio_resid; 372 error = VOP_READ(vp, uio, (fp->f_flag & FNONBLOCK) ? IO_NDELAY : 0, 373 cred); 374 fp->f_offset += count - uio->uio_resid; 375 VOP_UNLOCK(vp); 376 return (error); 377 } 378 379 /* 380 * File table vnode write routine. 381 */ 382 int 383 vn_write(fp, uio, cred) 384 struct file *fp; 385 struct uio *uio; 386 struct ucred *cred; 387 { 388 register struct vnode *vp = (struct vnode *)fp->f_data; 389 int count, error, ioflag = IO_UNIT; 390 391 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 392 ioflag |= IO_APPEND; 393 if (fp->f_flag & FNONBLOCK) 394 ioflag |= IO_NDELAY; 395 if (fp->f_flag & FFSYNC || 396 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS))) 397 ioflag |= IO_SYNC; 398 VOP_LEASE(vp, uio->uio_procp, cred, LEASE_WRITE); 399 VOP_LOCK(vp); 400 uio->uio_offset = fp->f_offset; 401 count = uio->uio_resid; 402 error = VOP_WRITE(vp, uio, ioflag, cred); 403 if (ioflag & IO_APPEND) 404 fp->f_offset = uio->uio_offset; 405 else 406 fp->f_offset += count - uio->uio_resid; 407 VOP_UNLOCK(vp); 408 return (error); 409 } 410 411 /* 412 * File table vnode stat routine. 413 */ 414 int 415 vn_stat(vp, sb, p) 416 struct vnode *vp; 417 register struct stat *sb; 418 struct proc *p; 419 { 420 struct vattr va; 421 int error; 422 u_short mode; 423 424 error = VOP_GETATTR(vp, &va, p->p_ucred, p); 425 if (error) 426 return (error); 427 /* 428 * Copy from vattr table 429 */ 430 sb->st_dev = va.va_fsid; 431 sb->st_ino = va.va_fileid; 432 mode = va.va_mode; 433 switch (vp->v_type) { 434 case VREG: 435 mode |= S_IFREG; 436 break; 437 case VDIR: 438 mode |= S_IFDIR; 439 break; 440 case VBLK: 441 mode |= S_IFBLK; 442 break; 443 case VCHR: 444 mode |= S_IFCHR; 445 break; 446 case VLNK: 447 mode |= S_IFLNK; 448 break; 449 case VSOCK: 450 mode |= S_IFSOCK; 451 break; 452 case VFIFO: 453 mode |= S_IFIFO; 454 break; 455 default: 456 return (EBADF); 457 }; 458 sb->st_mode = mode; 459 sb->st_nlink = va.va_nlink; 460 sb->st_uid = va.va_uid; 461 sb->st_gid = va.va_gid; 462 sb->st_rdev = va.va_rdev; 463 sb->st_size = va.va_size; 464 sb->st_atimespec = va.va_atime; 465 sb->st_mtimespec = va.va_mtime; 466 sb->st_ctimespec = va.va_ctime; 467 sb->st_blksize = va.va_blocksize; 468 sb->st_flags = va.va_flags; 469 sb->st_gen = 0; 470 sb->st_blocks = va.va_bytes / S_BLKSIZE; 471 return (0); 472 } 473 474 /* 475 * File table vnode ioctl routine. 476 */ 477 int 478 vn_ioctl(fp, com, data, p) 479 struct file *fp; 480 u_long com; 481 caddr_t data; 482 struct proc *p; 483 { 484 register struct vnode *vp = ((struct vnode *)fp->f_data); 485 struct vattr vattr; 486 int error; 487 488 switch (vp->v_type) { 489 490 case VREG: 491 case VDIR: 492 if (com == FIONREAD) { 493 error = VOP_GETATTR(vp, &vattr, p->p_ucred, p); 494 if (error) 495 return (error); 496 *(int *)data = vattr.va_size - fp->f_offset; 497 return (0); 498 } 499 if (com == FIONBIO || com == FIOASYNC) /* XXX */ 500 return (0); /* XXX */ 501 /* fall into ... */ 502 503 default: 504 return (ENOTTY); 505 506 case VFIFO: 507 case VCHR: 508 case VBLK: 509 error = VOP_IOCTL(vp, com, data, fp->f_flag, p->p_ucred, p); 510 if (error == 0 && com == TIOCSCTTY) { 511 if (p->p_session->s_ttyvp) 512 vrele(p->p_session->s_ttyvp); 513 p->p_session->s_ttyvp = vp; 514 VREF(vp); 515 } 516 return (error); 517 } 518 } 519 520 /* 521 * File table vnode poll routine. 522 */ 523 int 524 vn_poll(fp, events, p) 525 struct file *fp; 526 int events; 527 struct proc *p; 528 { 529 530 return (VOP_POLL(((struct vnode *)fp->f_data), events, p)); 531 } 532 533 /* 534 * File table vnode close routine. 535 */ 536 int 537 vn_closefile(fp, p) 538 struct file *fp; 539 struct proc *p; 540 { 541 542 return (vn_close(((struct vnode *)fp->f_data), fp->f_flag, 543 fp->f_cred, p)); 544 } 545
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