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 1.26 1996/08/21 21:55:23 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 * Make sure that a VM object is created for VMIO support. 166 */ 167 if (vp->v_type == VREG) { 168 if ((error = vfs_object_create(vp, p, cred, 1)) != 0) 169 goto bad; 170 } 171 172 if (fmode & FWRITE) 173 vp->v_writecount++; 174 return (0); 175 bad: 176 vput(vp); 177 return (error); 178 } 179 180 /* 181 * Check for write permissions on the specified vnode. 182 * The read-only status of the file system is checked. 183 * Also, prototype text segments cannot be written. 184 */ 185 int 186 vn_writechk(vp) 187 register struct vnode *vp; 188 { 189 190 /* 191 * If there's shared text associated with 192 * the vnode, try to free it up once. If 193 * we fail, we can't allow writing. 194 */ 195 if (vp->v_flag & VTEXT) 196 return (ETXTBSY); 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 /* 266 * File table vnode read routine. 267 */ 268 static int 269 vn_read(fp, uio, cred) 270 struct file *fp; 271 struct uio *uio; 272 struct ucred *cred; 273 { 274 register struct vnode *vp = (struct vnode *)fp->f_data; 275 int count, error; 276 int flag, seq; 277 278 LEASE_CHECK(vp, uio->uio_procp, cred, LEASE_READ); 279 VOP_LOCK(vp); 280 uio->uio_offset = fp->f_offset; 281 count = uio->uio_resid; 282 flag = 0; 283 if (fp->f_flag & FNONBLOCK) 284 flag |= IO_NDELAY; 285 286 /* 287 * Sequential read heuristic. 288 * If we have been doing sequential input, 289 * a rewind operation doesn't turn off 290 * sequential input mode. 291 */ 292 if (((fp->f_offset == 0) && (fp->f_seqcount > 0)) || 293 (fp->f_offset == fp->f_nextread)) { 294 int tmpseq = fp->f_seqcount; 295 /* 296 * XXX we assume that the filesystem block size is 297 * the default. Not true, but still gives us a pretty 298 * good indicator of how sequential the read operations 299 * are. 300 */ 301 tmpseq += ((count + BKVASIZE - 1) / BKVASIZE); 302 if (tmpseq >= CHAR_MAX) 303 tmpseq = CHAR_MAX; 304 fp->f_seqcount = tmpseq; 305 flag |= (fp->f_seqcount << 16); 306 } else { 307 if (fp->f_seqcount > 1) 308 fp->f_seqcount = 1; 309 else 310 fp->f_seqcount = 0; 311 } 312 313 error = VOP_READ(vp, uio, flag, cred); 314 fp->f_offset += count - uio->uio_resid; 315 fp->f_nextread = fp->f_offset; 316 VOP_UNLOCK(vp); 317 return (error); 318 } 319 320 /* 321 * File table vnode write routine. 322 */ 323 static int 324 vn_write(fp, uio, cred) 325 struct file *fp; 326 struct uio *uio; 327 struct ucred *cred; 328 { 329 register struct vnode *vp = (struct vnode *)fp->f_data; 330 int count, error, ioflag = 0; 331 332 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 333 ioflag |= IO_APPEND; 334 if (fp->f_flag & FNONBLOCK) 335 ioflag |= IO_NDELAY; 336 LEASE_CHECK(vp, uio->uio_procp, cred, LEASE_WRITE); 337 VOP_LOCK(vp); 338 uio->uio_offset = fp->f_offset; 339 count = uio->uio_resid; 340 error = VOP_WRITE(vp, uio, ioflag, cred); 341 if (ioflag & IO_APPEND) 342 fp->f_offset = uio->uio_offset; 343 else 344 fp->f_offset += count - uio->uio_resid; 345 VOP_UNLOCK(vp); 346 return (error); 347 } 348 349 /* 350 * File table vnode stat routine. 351 */ 352 int 353 vn_stat(vp, sb, p) 354 struct vnode *vp; 355 register struct stat *sb; 356 struct proc *p; 357 { 358 struct vattr vattr; 359 register struct vattr *vap; 360 int error; 361 u_short mode; 362 363 vap = &vattr; 364 error = VOP_GETATTR(vp, vap, p->p_ucred, p); 365 if (error) 366 return (error); 367 /* 368 * Copy from vattr table 369 */ 370 sb->st_dev = vap->va_fsid; 371 sb->st_ino = vap->va_fileid; 372 mode = vap->va_mode; 373 switch (vp->v_type) { 374 case VREG: 375 mode |= S_IFREG; 376 break; 377 case VDIR: 378 mode |= S_IFDIR; 379 break; 380 case VBLK: 381 mode |= S_IFBLK; 382 break; 383 case VCHR: 384 mode |= S_IFCHR; 385 break; 386 case VLNK: 387 mode |= S_IFLNK; 388 break; 389 case VSOCK: 390 mode |= S_IFSOCK; 391 break; 392 case VFIFO: 393 mode |= S_IFIFO; 394 break; 395 default: 396 return (EBADF); 397 }; 398 sb->st_mode = mode; 399 sb->st_nlink = vap->va_nlink; 400 sb->st_uid = vap->va_uid; 401 sb->st_gid = vap->va_gid; 402 sb->st_rdev = vap->va_rdev; 403 sb->st_size = vap->va_size; 404 sb->st_atimespec = vap->va_atime; 405 sb->st_mtimespec= vap->va_mtime; 406 sb->st_ctimespec = vap->va_ctime; 407 sb->st_blksize = vap->va_blocksize; 408 sb->st_flags = vap->va_flags; 409 sb->st_gen = vap->va_gen; 410 #if (S_BLKSIZE == 512) 411 /* Optimize this case */ 412 sb->st_blocks = vap->va_bytes >> 9; 413 #else 414 sb->st_blocks = vap->va_bytes / S_BLKSIZE; 415 #endif 416 return (0); 417 } 418 419 /* 420 * File table vnode ioctl routine. 421 */ 422 static int 423 vn_ioctl(fp, com, data, p) 424 struct file *fp; 425 int com; 426 caddr_t data; 427 struct proc *p; 428 { 429 register struct vnode *vp = ((struct vnode *)fp->f_data); 430 struct vattr vattr; 431 int error; 432 433 switch (vp->v_type) { 434 435 case VREG: 436 case VDIR: 437 if (com == FIONREAD) { 438 error = VOP_GETATTR(vp, &vattr, p->p_ucred, p); 439 if (error) 440 return (error); 441 *(int *)data = vattr.va_size - fp->f_offset; 442 return (0); 443 } 444 if (com == FIONBIO || com == FIOASYNC) /* XXX */ 445 return (0); /* XXX */ 446 /* fall into ... */ 447 448 default: 449 return (ENOTTY); 450 451 case VFIFO: 452 case VCHR: 453 case VBLK: 454 error = VOP_IOCTL(vp, com, data, fp->f_flag, p->p_ucred, p); 455 if (error == 0 && com == TIOCSCTTY) { 456 457 /* Do nothing if reassigning same control tty */ 458 if (p->p_session->s_ttyvp == vp) 459 return (0); 460 461 /* Get rid of reference to old control tty */ 462 if (p->p_session->s_ttyvp) 463 vrele(p->p_session->s_ttyvp); 464 465 p->p_session->s_ttyvp = vp; 466 VREF(vp); 467 } 468 return (error); 469 } 470 } 471 472 /* 473 * File table vnode select routine. 474 */ 475 static int 476 vn_select(fp, which, p) 477 struct file *fp; 478 int which; 479 struct proc *p; 480 { 481 482 return (VOP_SELECT(((struct vnode *)fp->f_data), which, fp->f_flag, 483 fp->f_cred, p)); 484 } 485 486 /* 487 * File table vnode close routine. 488 */ 489 static int 490 vn_closefile(fp, p) 491 struct file *fp; 492 struct proc *p; 493 { 494 495 return (vn_close(((struct vnode *)fp->f_data), fp->f_flag, 496 fp->f_cred, p)); 497 } 498