1 /* 2 * Copyright (c) 1982, 1986, 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * @(#)vfs_vnops.c 8.2 (Berkeley) 1/21/94 39 * $Id: vfs_vnops.c,v 1.24 1996/03/02 03:45:05 dyson Exp $ 40 */ 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/kernel.h> 45 #include <sys/file.h> 46 #include <sys/stat.h> 47 #include <sys/buf.h> 48 #include <sys/proc.h> 49 #include <sys/mount.h> 50 #include <sys/namei.h> 51 #include <sys/vnode.h> 52 #include <sys/ioctl.h> 53 54 #include <vm/vm.h> 55 #include <vm/vm_param.h> 56 #include <vm/vm_object.h> 57 #include <vm/vnode_pager.h> 58 59 static int vn_closefile __P((struct file *fp, struct proc *p)); 60 static int vn_ioctl __P((struct file *fp, int com, caddr_t data, 61 struct proc *p)); 62 static int vn_read __P((struct file *fp, struct uio *uio, 63 struct ucred *cred)); 64 static int vn_select __P((struct file *fp, int which, struct proc *p)); 65 static int vn_write __P((struct file *fp, struct uio *uio, 66 struct ucred *cred)); 67 68 struct fileops vnops = 69 { vn_read, vn_write, vn_ioctl, vn_select, vn_closefile }; 70 71 /* 72 * Common code for vnode open operations. 73 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine. 74 */ 75 int 76 vn_open(ndp, fmode, cmode) 77 register struct nameidata *ndp; 78 int fmode, cmode; 79 { 80 register struct vnode *vp; 81 register struct proc *p = ndp->ni_cnd.cn_proc; 82 register struct ucred *cred = p->p_ucred; 83 struct vattr vat; 84 struct vattr *vap = &vat; 85 int error; 86 87 if (fmode & O_CREAT) { 88 ndp->ni_cnd.cn_nameiop = CREATE; 89 ndp->ni_cnd.cn_flags = LOCKPARENT | LOCKLEAF; 90 if ((fmode & O_EXCL) == 0) 91 ndp->ni_cnd.cn_flags |= FOLLOW; 92 error = namei(ndp); 93 if (error) 94 return (error); 95 if (ndp->ni_vp == NULL) { 96 VATTR_NULL(vap); 97 vap->va_type = VREG; 98 vap->va_mode = cmode; 99 LEASE_CHECK(ndp->ni_dvp, p, cred, LEASE_WRITE); 100 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp, 101 &ndp->ni_cnd, vap); 102 if (error) 103 return (error); 104 fmode &= ~O_TRUNC; 105 vp = ndp->ni_vp; 106 } else { 107 VOP_ABORTOP(ndp->ni_dvp, &ndp->ni_cnd); 108 if (ndp->ni_dvp == ndp->ni_vp) 109 vrele(ndp->ni_dvp); 110 else 111 vput(ndp->ni_dvp); 112 ndp->ni_dvp = NULL; 113 vp = ndp->ni_vp; 114 if (fmode & O_EXCL) { 115 error = EEXIST; 116 goto bad; 117 } 118 fmode &= ~O_CREAT; 119 } 120 } else { 121 ndp->ni_cnd.cn_nameiop = LOOKUP; 122 ndp->ni_cnd.cn_flags = FOLLOW | LOCKLEAF; 123 error = namei(ndp); 124 if (error) 125 return (error); 126 vp = ndp->ni_vp; 127 } 128 if (vp->v_type == VSOCK) { 129 error = EOPNOTSUPP; 130 goto bad; 131 } 132 if ((fmode & O_CREAT) == 0) { 133 if (fmode & FREAD) { 134 error = VOP_ACCESS(vp, VREAD, cred, p); 135 if (error) 136 goto bad; 137 } 138 if (fmode & (FWRITE | O_TRUNC)) { 139 if (vp->v_type == VDIR) { 140 error = EISDIR; 141 goto bad; 142 } 143 error = vn_writechk(vp); 144 if (error) 145 goto bad; 146 error = VOP_ACCESS(vp, VWRITE, cred, p); 147 if (error) 148 goto bad; 149 } 150 } 151 if (fmode & O_TRUNC) { 152 VOP_UNLOCK(vp); /* XXX */ 153 LEASE_CHECK(vp, p, cred, LEASE_WRITE); 154 VOP_LOCK(vp); /* XXX */ 155 VATTR_NULL(vap); 156 vap->va_size = 0; 157 error = VOP_SETATTR(vp, vap, cred, p); 158 if (error) 159 goto bad; 160 } 161 error = VOP_OPEN(vp, fmode, cred, p); 162 if (error) 163 goto bad; 164 /* 165 * this is here for VMIO support 166 */ 167 if (vp->v_type == VREG) { 168 if ((error = vn_vmio_open(vp, p, cred)) != 0) 169 goto bad; 170 } 171 if (fmode & FWRITE) 172 vp->v_writecount++; 173 return (0); 174 bad: 175 vput(vp); 176 return (error); 177 } 178 179 /* 180 * Check for write permissions on the specified vnode. 181 * The read-only status of the file system is checked. 182 * Also, prototype text segments cannot be written. 183 */ 184 int 185 vn_writechk(vp) 186 register struct vnode *vp; 187 { 188 189 /* 190 * If there's shared text associated with 191 * the vnode, try to free it up once. If 192 * we fail, we can't allow writing. 193 */ 194 if (vp->v_flag & VTEXT) 195 return (ETXTBSY); 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 vn_vmio_close(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 int *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 VOP_LOCK(vp); 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); 261 return (error); 262 } 263 264 /* 265 * File table vnode read routine. 266 */ 267 static int 268 vn_read(fp, uio, cred) 269 struct file *fp; 270 struct uio *uio; 271 struct ucred *cred; 272 { 273 register struct vnode *vp = (struct vnode *)fp->f_data; 274 int count, error; 275 276 LEASE_CHECK(vp, uio->uio_procp, cred, LEASE_READ); 277 VOP_LOCK(vp); 278 uio->uio_offset = fp->f_offset; 279 count = uio->uio_resid; 280 error = VOP_READ(vp, uio, (fp->f_flag & FNONBLOCK) ? IO_NDELAY : 0, 281 cred); 282 fp->f_offset += count - uio->uio_resid; 283 VOP_UNLOCK(vp); 284 return (error); 285 } 286 287 /* 288 * File table vnode write routine. 289 */ 290 static int 291 vn_write(fp, uio, cred) 292 struct file *fp; 293 struct uio *uio; 294 struct ucred *cred; 295 { 296 register struct vnode *vp = (struct vnode *)fp->f_data; 297 int count, error, ioflag = 0; 298 299 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 300 ioflag |= IO_APPEND; 301 if (fp->f_flag & FNONBLOCK) 302 ioflag |= IO_NDELAY; 303 LEASE_CHECK(vp, uio->uio_procp, cred, LEASE_WRITE); 304 VOP_LOCK(vp); 305 uio->uio_offset = fp->f_offset; 306 count = uio->uio_resid; 307 error = VOP_WRITE(vp, uio, ioflag, cred); 308 if (ioflag & IO_APPEND) 309 fp->f_offset = uio->uio_offset; 310 else 311 fp->f_offset += count - uio->uio_resid; 312 VOP_UNLOCK(vp); 313 return (error); 314 } 315 316 /* 317 * File table vnode stat routine. 318 */ 319 int 320 vn_stat(vp, sb, p) 321 struct vnode *vp; 322 register struct stat *sb; 323 struct proc *p; 324 { 325 struct vattr vattr; 326 register struct vattr *vap; 327 int error; 328 u_short mode; 329 330 vap = &vattr; 331 error = VOP_GETATTR(vp, vap, p->p_ucred, p); 332 if (error) 333 return (error); 334 /* 335 * Copy from vattr table 336 */ 337 sb->st_dev = vap->va_fsid; 338 sb->st_ino = vap->va_fileid; 339 mode = vap->va_mode; 340 switch (vp->v_type) { 341 case VREG: 342 mode |= S_IFREG; 343 break; 344 case VDIR: 345 mode |= S_IFDIR; 346 break; 347 case VBLK: 348 mode |= S_IFBLK; 349 break; 350 case VCHR: 351 mode |= S_IFCHR; 352 break; 353 case VLNK: 354 mode |= S_IFLNK; 355 break; 356 case VSOCK: 357 mode |= S_IFSOCK; 358 break; 359 case VFIFO: 360 mode |= S_IFIFO; 361 break; 362 default: 363 return (EBADF); 364 }; 365 sb->st_mode = mode; 366 sb->st_nlink = vap->va_nlink; 367 sb->st_uid = vap->va_uid; 368 sb->st_gid = vap->va_gid; 369 sb->st_rdev = vap->va_rdev; 370 sb->st_size = vap->va_size; 371 sb->st_atimespec = vap->va_atime; 372 sb->st_mtimespec= vap->va_mtime; 373 sb->st_ctimespec = vap->va_ctime; 374 sb->st_blksize = vap->va_blocksize; 375 sb->st_flags = vap->va_flags; 376 sb->st_gen = vap->va_gen; 377 #if (S_BLKSIZE == 512) 378 /* Optimize this case */ 379 sb->st_blocks = vap->va_bytes >> 9; 380 #else 381 sb->st_blocks = vap->va_bytes / S_BLKSIZE; 382 #endif 383 return (0); 384 } 385 386 /* 387 * File table vnode ioctl routine. 388 */ 389 static int 390 vn_ioctl(fp, com, data, p) 391 struct file *fp; 392 int com; 393 caddr_t data; 394 struct proc *p; 395 { 396 register struct vnode *vp = ((struct vnode *)fp->f_data); 397 struct vattr vattr; 398 int error; 399 400 switch (vp->v_type) { 401 402 case VREG: 403 case VDIR: 404 if (com == FIONREAD) { 405 error = VOP_GETATTR(vp, &vattr, p->p_ucred, p); 406 if (error) 407 return (error); 408 *(int *)data = vattr.va_size - fp->f_offset; 409 return (0); 410 } 411 if (com == FIONBIO || com == FIOASYNC) /* XXX */ 412 return (0); /* XXX */ 413 /* fall into ... */ 414 415 default: 416 return (ENOTTY); 417 418 case VFIFO: 419 case VCHR: 420 case VBLK: 421 error = VOP_IOCTL(vp, com, data, fp->f_flag, p->p_ucred, p); 422 if (error == 0 && com == TIOCSCTTY) { 423 424 /* Do nothing if reassigning same control tty */ 425 if (p->p_session->s_ttyvp == vp) 426 return (0); 427 428 /* Get rid of reference to old control tty */ 429 if (p->p_session->s_ttyvp) 430 vrele(p->p_session->s_ttyvp); 431 432 p->p_session->s_ttyvp = vp; 433 VREF(vp); 434 } 435 return (error); 436 } 437 } 438 439 /* 440 * File table vnode select routine. 441 */ 442 static int 443 vn_select(fp, which, p) 444 struct file *fp; 445 int which; 446 struct proc *p; 447 { 448 449 return (VOP_SELECT(((struct vnode *)fp->f_data), which, fp->f_flag, 450 fp->f_cred, p)); 451 } 452 453 /* 454 * File table vnode close routine. 455 */ 456 static int 457 vn_closefile(fp, p) 458 struct file *fp; 459 struct proc *p; 460 { 461 462 return (vn_close(((struct vnode *)fp->f_data), fp->f_flag, 463 fp->f_cred, p)); 464 } 465 466 int 467 vn_vmio_open(vp, p, cred) 468 struct vnode *vp; 469 struct proc *p; 470 struct ucred *cred; 471 { 472 struct vattr vat; 473 int error; 474 /* 475 * this is here for VMIO support 476 */ 477 if (vp->v_type == VREG || vp->v_type == VBLK) { 478 retry: 479 if ((vp->v_flag & VVMIO) == 0) { 480 if ((error = VOP_GETATTR(vp, &vat, cred, p)) != 0) 481 return error; 482 (void) vnode_pager_alloc(vp, OFF_TO_IDX(round_page(vat.va_size)), 0, 0); 483 vp->v_flag |= VVMIO; 484 } else { 485 vm_object_t object; 486 if ((object = vp->v_object) && 487 (object->flags & OBJ_DEAD)) { 488 VOP_UNLOCK(vp); 489 tsleep(object, PVM, "vodead", 0); 490 VOP_LOCK(vp); 491 goto retry; 492 } 493 if (!object) 494 panic("vn_open: VMIO object missing"); 495 vm_object_reference(object); 496 } 497 } 498 return 0; 499 } 500 501 void 502 vn_vmio_close(vp) 503 struct vnode *vp; 504 { 505 /* 506 * this code is here for VMIO support, will eventually 507 * be in vfs code. 508 */ 509 if (vp->v_flag & VVMIO) { 510 vrele(vp); 511 if (vp->v_object == NULL) 512 panic("vn_close: VMIO object missing"); 513 vm_object_deallocate(vp->v_object); 514 } else 515 vrele(vp); 516 } 517