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 1.35 1997/04/04 17:46:21 dfr Exp $ 40 */ 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/kernel.h> 45 #include <sys/fcntl.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/filio.h> 54 #include <sys/ttycom.h> 55 56 #include <vm/vm.h> 57 #include <vm/vm_param.h> 58 #include <vm/vm_object.h> 59 #include <vm/vnode_pager.h> 60 61 static int vn_closefile __P((struct file *fp, struct proc *p)); 62 static int vn_ioctl __P((struct file *fp, int com, caddr_t data, 63 struct proc *p)); 64 static int vn_read __P((struct file *fp, struct uio *uio, 65 struct ucred *cred)); 66 static int vn_select __P((struct file *fp, int which, struct proc *p)); 67 static int vn_write __P((struct file *fp, struct uio *uio, 68 struct ucred *cred)); 69 70 struct fileops vnops = 71 { vn_read, vn_write, vn_ioctl, vn_select, 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 vat; 86 struct vattr *vap = &vat; 87 int error; 88 89 if (fmode & O_CREAT) { 90 ndp->ni_cnd.cn_nameiop = CREATE; 91 ndp->ni_cnd.cn_flags = LOCKPARENT | LOCKLEAF; 92 if ((fmode & O_EXCL) == 0) 93 ndp->ni_cnd.cn_flags |= FOLLOW; 94 error = namei(ndp); 95 if (error) 96 return (error); 97 if (ndp->ni_vp == NULL) { 98 VATTR_NULL(vap); 99 vap->va_type = VREG; 100 vap->va_mode = cmode; 101 if (fmode & O_EXCL) 102 vap->va_vaflags |= VA_EXCLUSIVE; 103 VOP_LEASE(ndp->ni_dvp, p, cred, LEASE_WRITE); 104 if (error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp, 105 &ndp->ni_cnd, vap)) 106 return (error); 107 ASSERT_VOP_UNLOCKED(ndp->ni_dvp, "create"); 108 ASSERT_VOP_LOCKED(ndp->ni_vp, "create"); 109 fmode &= ~O_TRUNC; 110 vp = ndp->ni_vp; 111 } else { 112 VOP_ABORTOP(ndp->ni_dvp, &ndp->ni_cnd); 113 if (ndp->ni_dvp == ndp->ni_vp) 114 vrele(ndp->ni_dvp); 115 else 116 vput(ndp->ni_dvp); 117 ndp->ni_dvp = NULL; 118 vp = ndp->ni_vp; 119 if (fmode & O_EXCL) { 120 error = EEXIST; 121 goto bad; 122 } 123 fmode &= ~O_CREAT; 124 } 125 } else { 126 ndp->ni_cnd.cn_nameiop = LOOKUP; 127 ndp->ni_cnd.cn_flags = FOLLOW | LOCKLEAF; 128 error = namei(ndp); 129 if (error) 130 return (error); 131 vp = ndp->ni_vp; 132 } 133 if (vp->v_type == VSOCK) { 134 error = EOPNOTSUPP; 135 goto bad; 136 } 137 if ((fmode & O_CREAT) == 0) { 138 if (fmode & FREAD) { 139 error = VOP_ACCESS(vp, VREAD, cred, p); 140 if (error) 141 goto bad; 142 } 143 if (fmode & (FWRITE | O_TRUNC)) { 144 if (vp->v_type == VDIR) { 145 error = EISDIR; 146 goto bad; 147 } 148 error = vn_writechk(vp); 149 if (error) 150 goto bad; 151 error = VOP_ACCESS(vp, VWRITE, cred, p); 152 if (error) 153 goto bad; 154 } 155 } 156 if (fmode & O_TRUNC) { 157 VOP_UNLOCK(vp, 0, p); /* XXX */ 158 VOP_LEASE(vp, p, cred, LEASE_WRITE); 159 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); /* XXX */ 160 VATTR_NULL(vap); 161 vap->va_size = 0; 162 error = VOP_SETATTR(vp, vap, cred, p); 163 if (error) 164 goto bad; 165 } 166 error = VOP_OPEN(vp, fmode, cred, p); 167 if (error) 168 goto bad; 169 /* 170 * Make sure that a VM object is created for VMIO support. 171 */ 172 if (vp->v_type == VREG) { 173 if ((error = vfs_object_create(vp, p, cred, 1)) != 0) 174 goto bad; 175 } 176 177 if (fmode & FWRITE) 178 vp->v_writecount++; 179 return (0); 180 bad: 181 vput(vp); 182 return (error); 183 } 184 185 /* 186 * Check for write permissions on the specified vnode. 187 * Prototype text segments cannot be written. 188 */ 189 int 190 vn_writechk(vp) 191 register struct vnode *vp; 192 { 193 194 /* 195 * If there's shared text associated with 196 * the vnode, try to free it up once. If 197 * we fail, we can't allow writing. 198 */ 199 if (vp->v_flag & VTEXT) 200 return (ETXTBSY); 201 return (0); 202 } 203 204 /* 205 * Vnode close call 206 */ 207 int 208 vn_close(vp, flags, cred, p) 209 register struct vnode *vp; 210 int flags; 211 struct ucred *cred; 212 struct proc *p; 213 { 214 int error; 215 216 if (flags & FWRITE) 217 vp->v_writecount--; 218 error = VOP_CLOSE(vp, flags, cred, p); 219 vrele(vp); 220 return (error); 221 } 222 223 /* 224 * Package up an I/O request on a vnode into a uio and do it. 225 */ 226 int 227 vn_rdwr(rw, vp, base, len, offset, segflg, ioflg, cred, aresid, p) 228 enum uio_rw rw; 229 struct vnode *vp; 230 caddr_t base; 231 int len; 232 off_t offset; 233 enum uio_seg segflg; 234 int ioflg; 235 struct ucred *cred; 236 int *aresid; 237 struct proc *p; 238 { 239 struct uio auio; 240 struct iovec aiov; 241 int error; 242 243 if ((ioflg & IO_NODELOCKED) == 0) 244 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); 245 auio.uio_iov = &aiov; 246 auio.uio_iovcnt = 1; 247 aiov.iov_base = base; 248 aiov.iov_len = len; 249 auio.uio_resid = len; 250 auio.uio_offset = offset; 251 auio.uio_segflg = segflg; 252 auio.uio_rw = rw; 253 auio.uio_procp = p; 254 if (rw == UIO_READ) { 255 error = VOP_READ(vp, &auio, ioflg, cred); 256 } else { 257 error = VOP_WRITE(vp, &auio, ioflg, cred); 258 } 259 if (aresid) 260 *aresid = auio.uio_resid; 261 else 262 if (auio.uio_resid && error == 0) 263 error = EIO; 264 if ((ioflg & IO_NODELOCKED) == 0) 265 VOP_UNLOCK(vp, 0, p); 266 return (error); 267 } 268 269 /* 270 * File table vnode read routine. 271 */ 272 static int 273 vn_read(fp, uio, cred) 274 struct file *fp; 275 struct uio *uio; 276 struct ucred *cred; 277 { 278 struct vnode *vp = (struct vnode *)fp->f_data; 279 struct proc *p = uio->uio_procp; 280 int count, error; 281 int flag, seq; 282 283 VOP_LEASE(vp, p, cred, LEASE_READ); 284 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); 285 uio->uio_offset = fp->f_offset; 286 count = uio->uio_resid; 287 flag = 0; 288 if (fp->f_flag & FNONBLOCK) 289 flag |= IO_NDELAY; 290 291 /* 292 * Sequential read heuristic. 293 * If we have been doing sequential input, 294 * a rewind operation doesn't turn off 295 * sequential input mode. 296 */ 297 if (((fp->f_offset == 0) && (fp->f_seqcount > 0)) || 298 (fp->f_offset == fp->f_nextread)) { 299 int tmpseq = fp->f_seqcount; 300 /* 301 * XXX we assume that the filesystem block size is 302 * the default. Not true, but still gives us a pretty 303 * good indicator of how sequential the read operations 304 * are. 305 */ 306 tmpseq += ((count + BKVASIZE - 1) / BKVASIZE); 307 if (tmpseq >= CHAR_MAX) 308 tmpseq = CHAR_MAX; 309 fp->f_seqcount = tmpseq; 310 flag |= (fp->f_seqcount << 16); 311 } else { 312 if (fp->f_seqcount > 1) 313 fp->f_seqcount = 1; 314 else 315 fp->f_seqcount = 0; 316 } 317 318 error = VOP_READ(vp, uio, flag, cred); 319 fp->f_offset += count - uio->uio_resid; 320 fp->f_nextread = fp->f_offset; 321 VOP_UNLOCK(vp, 0, p); 322 return (error); 323 } 324 325 /* 326 * File table vnode write routine. 327 */ 328 static int 329 vn_write(fp, uio, cred) 330 struct file *fp; 331 struct uio *uio; 332 struct ucred *cred; 333 { 334 struct vnode *vp = (struct vnode *)fp->f_data; 335 struct proc *p = uio->uio_procp; 336 int count, error, ioflag = IO_UNIT; 337 338 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 339 ioflag |= IO_APPEND; 340 if (fp->f_flag & FNONBLOCK) 341 ioflag |= IO_NDELAY; 342 if ((fp->f_flag & O_FSYNC) || 343 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS))) 344 ioflag |= IO_SYNC; 345 VOP_LEASE(vp, p, cred, LEASE_WRITE); 346 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); 347 uio->uio_offset = fp->f_offset; 348 count = uio->uio_resid; 349 error = VOP_WRITE(vp, uio, ioflag, cred); 350 if (ioflag & IO_APPEND) 351 fp->f_offset = uio->uio_offset; 352 else 353 fp->f_offset += count - uio->uio_resid; 354 VOP_UNLOCK(vp, 0, p); 355 return (error); 356 } 357 358 /* 359 * File table vnode stat routine. 360 */ 361 int 362 vn_stat(vp, sb, p) 363 struct vnode *vp; 364 register struct stat *sb; 365 struct proc *p; 366 { 367 struct vattr vattr; 368 register struct vattr *vap; 369 int error; 370 u_short mode; 371 372 vap = &vattr; 373 error = VOP_GETATTR(vp, vap, p->p_ucred, p); 374 if (error) 375 return (error); 376 /* 377 * Copy from vattr table 378 */ 379 sb->st_dev = vap->va_fsid; 380 sb->st_ino = vap->va_fileid; 381 mode = vap->va_mode; 382 switch (vp->v_type) { 383 case VREG: 384 mode |= S_IFREG; 385 break; 386 case VDIR: 387 mode |= S_IFDIR; 388 break; 389 case VBLK: 390 mode |= S_IFBLK; 391 break; 392 case VCHR: 393 mode |= S_IFCHR; 394 break; 395 case VLNK: 396 mode |= S_IFLNK; 397 break; 398 case VSOCK: 399 mode |= S_IFSOCK; 400 break; 401 case VFIFO: 402 mode |= S_IFIFO; 403 break; 404 default: 405 return (EBADF); 406 }; 407 sb->st_mode = mode; 408 sb->st_nlink = vap->va_nlink; 409 sb->st_uid = vap->va_uid; 410 sb->st_gid = vap->va_gid; 411 sb->st_rdev = vap->va_rdev; 412 sb->st_size = vap->va_size; 413 sb->st_atimespec = vap->va_atime; 414 sb->st_mtimespec = vap->va_mtime; 415 sb->st_ctimespec = vap->va_ctime; 416 sb->st_blksize = vap->va_blocksize; 417 sb->st_flags = vap->va_flags; 418 if (p->p_ucred->cr_uid != 0) 419 sb->st_gen = 0; 420 else 421 sb->st_gen = vap->va_gen; 422 423 #if (S_BLKSIZE == 512) 424 /* Optimize this case */ 425 sb->st_blocks = vap->va_bytes >> 9; 426 #else 427 sb->st_blocks = vap->va_bytes / S_BLKSIZE; 428 #endif 429 return (0); 430 } 431 432 /* 433 * File table vnode ioctl routine. 434 */ 435 static int 436 vn_ioctl(fp, com, data, p) 437 struct file *fp; 438 int com; 439 caddr_t data; 440 struct proc *p; 441 { 442 register struct vnode *vp = ((struct vnode *)fp->f_data); 443 struct vattr vattr; 444 int error; 445 446 switch (vp->v_type) { 447 448 case VREG: 449 case VDIR: 450 if (com == FIONREAD) { 451 error = VOP_GETATTR(vp, &vattr, p->p_ucred, p); 452 if (error) 453 return (error); 454 *(int *)data = vattr.va_size - fp->f_offset; 455 return (0); 456 } 457 if (com == FIONBIO || com == FIOASYNC) /* XXX */ 458 return (0); /* XXX */ 459 /* fall into ... */ 460 461 default: 462 return (ENOTTY); 463 464 case VFIFO: 465 case VCHR: 466 case VBLK: 467 error = VOP_IOCTL(vp, com, data, fp->f_flag, p->p_ucred, p); 468 if (error == 0 && com == TIOCSCTTY) { 469 470 /* Do nothing if reassigning same control tty */ 471 if (p->p_session->s_ttyvp == vp) 472 return (0); 473 474 /* Get rid of reference to old control tty */ 475 if (p->p_session->s_ttyvp) 476 vrele(p->p_session->s_ttyvp); 477 478 p->p_session->s_ttyvp = vp; 479 VREF(vp); 480 } 481 return (error); 482 } 483 } 484 485 /* 486 * File table vnode select routine. 487 */ 488 static int 489 vn_select(fp, which, p) 490 struct file *fp; 491 int which; 492 struct proc *p; 493 { 494 495 return (VOP_SELECT(((struct vnode *)fp->f_data), which, fp->f_flag, 496 fp->f_cred, p)); 497 } 498 499 /* 500 * File table vnode close routine. 501 */ 502 static int 503 vn_closefile(fp, p) 504 struct file *fp; 505 struct proc *p; 506 { 507 508 return (vn_close(((struct vnode *)fp->f_data), fp->f_flag, 509 fp->f_cred, p)); 510 } 511 512 /* 513 * Check that the vnode is still valid, and if so 514 * acquire requested lock. 515 */ 516 int 517 vn_lock(vp, flags, p) 518 struct vnode *vp; 519 int flags; 520 struct proc *p; 521 { 522 int error; 523 524 do { 525 if ((flags & LK_INTERLOCK) == 0) { 526 simple_lock(&vp->v_interlock); 527 } 528 if (vp->v_flag & VXLOCK) { 529 vp->v_flag |= VXWANT; 530 simple_unlock(&vp->v_interlock); 531 tsleep((caddr_t)vp, PINOD, "vn_lock", 0); 532 error = ENOENT; 533 } else { 534 error = VOP_LOCK(vp, flags | LK_INTERLOCK, p); 535 if (error == 0) 536 return (error); 537 } 538 flags &= ~LK_INTERLOCK; 539 } while (flags & LK_RETRY); 540 return (error); 541 } 542