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 1.17 1995/07/20 09:43:04 davidg 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/vnode_pager.h> 56 57 struct fileops vnops = 58 { vn_read, vn_write, vn_ioctl, vn_select, vn_closefile }; 59 60 /* 61 * Common code for vnode open operations. 62 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine. 63 */ 64 int 65 vn_open(ndp, fmode, cmode) 66 register struct nameidata *ndp; 67 int fmode, cmode; 68 { 69 register struct vnode *vp; 70 register struct proc *p = ndp->ni_cnd.cn_proc; 71 register struct ucred *cred = p->p_ucred; 72 struct vattr vat; 73 struct vattr *vap = &vat; 74 int error; 75 76 if (fmode & O_CREAT) { 77 ndp->ni_cnd.cn_nameiop = CREATE; 78 ndp->ni_cnd.cn_flags = LOCKPARENT | LOCKLEAF; 79 if ((fmode & O_EXCL) == 0) 80 ndp->ni_cnd.cn_flags |= FOLLOW; 81 error = namei(ndp); 82 if (error) 83 return (error); 84 if (ndp->ni_vp == NULL) { 85 VATTR_NULL(vap); 86 vap->va_type = VREG; 87 vap->va_mode = cmode; 88 LEASE_CHECK(ndp->ni_dvp, p, cred, LEASE_WRITE); 89 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp, 90 &ndp->ni_cnd, vap); 91 if (error) 92 return (error); 93 fmode &= ~O_TRUNC; 94 vp = ndp->ni_vp; 95 } else { 96 VOP_ABORTOP(ndp->ni_dvp, &ndp->ni_cnd); 97 if (ndp->ni_dvp == ndp->ni_vp) 98 vrele(ndp->ni_dvp); 99 else 100 vput(ndp->ni_dvp); 101 ndp->ni_dvp = NULL; 102 vp = ndp->ni_vp; 103 if (fmode & O_EXCL) { 104 error = EEXIST; 105 goto bad; 106 } 107 fmode &= ~O_CREAT; 108 } 109 } else { 110 ndp->ni_cnd.cn_nameiop = LOOKUP; 111 ndp->ni_cnd.cn_flags = FOLLOW | LOCKLEAF; 112 error = namei(ndp); 113 if (error) 114 return (error); 115 vp = ndp->ni_vp; 116 } 117 if (vp->v_type == VSOCK) { 118 error = EOPNOTSUPP; 119 goto bad; 120 } 121 if ((fmode & O_CREAT) == 0) { 122 if (fmode & FREAD) { 123 error = VOP_ACCESS(vp, VREAD, cred, p); 124 if (error) 125 goto bad; 126 } 127 if (fmode & (FWRITE | O_TRUNC)) { 128 if (vp->v_type == VDIR) { 129 error = EISDIR; 130 goto bad; 131 } 132 error = vn_writechk(vp); 133 if (error) 134 goto bad; 135 error = VOP_ACCESS(vp, VWRITE, cred, p); 136 if (error) 137 goto bad; 138 } 139 } 140 if (fmode & O_TRUNC) { 141 VOP_UNLOCK(vp); /* XXX */ 142 LEASE_CHECK(vp, p, cred, LEASE_WRITE); 143 VOP_LOCK(vp); /* XXX */ 144 VATTR_NULL(vap); 145 vap->va_size = 0; 146 error = VOP_SETATTR(vp, vap, cred, p); 147 if (error) 148 goto bad; 149 } 150 error = VOP_OPEN(vp, fmode, cred, p); 151 if (error) 152 goto bad; 153 /* 154 * this is here for VMIO support 155 */ 156 if (vp->v_type == VREG) { 157 retry: 158 if ((vp->v_flag & VVMIO) == 0) { 159 error = VOP_GETATTR(vp, vap, cred, p); 160 if (error) 161 goto bad; 162 (void) vnode_pager_alloc(vp, vap->va_size, 0, 0); 163 vp->v_flag |= VVMIO; 164 } else { 165 vm_object_t object; 166 if ((object = vp->v_object) && 167 (object->flags & OBJ_DEAD)) { 168 VOP_UNLOCK(vp); 169 tsleep(object, PVM, "vodead", 0); 170 VOP_LOCK(vp); 171 goto retry; 172 } 173 if (!object) 174 panic("vn_open: VMIO object missing"); 175 vm_object_reference(object); 176 } 177 } 178 if (fmode & FWRITE) 179 vp->v_writecount++; 180 return (0); 181 bad: 182 vput(vp); 183 return (error); 184 } 185 186 /* 187 * Check for write permissions on the specified vnode. 188 * The read-only status of the file system is checked. 189 * Also, prototype text segments cannot be written. 190 */ 191 int 192 vn_writechk(vp) 193 register struct vnode *vp; 194 { 195 196 /* 197 * Disallow write attempts on read-only file systems; 198 * unless the file is a socket or a block or character 199 * device resident on the file system. 200 */ 201 if (vp->v_mount->mnt_flag & MNT_RDONLY) { 202 switch (vp->v_type) { 203 case VREG: case VDIR: case VLNK: 204 return (EROFS); 205 default: 206 break; 207 } 208 } 209 /* 210 * If there's shared text associated with 211 * the vnode, try to free it up once. If 212 * we fail, we can't allow writing. 213 */ 214 if (vp->v_flag & VTEXT) 215 return (ETXTBSY); 216 return (0); 217 } 218 219 /* 220 * Vnode close call 221 */ 222 int 223 vn_close(vp, flags, cred, p) 224 register struct vnode *vp; 225 int flags; 226 struct ucred *cred; 227 struct proc *p; 228 { 229 int error; 230 231 if (flags & FWRITE) 232 vp->v_writecount--; 233 error = VOP_CLOSE(vp, flags, cred, p); 234 /* 235 * this code is here for VMIO support, will eventually 236 * be in vfs code. 237 */ 238 if (vp->v_flag & VVMIO) { 239 vrele(vp); 240 if (vp->v_object == NULL) 241 panic("vn_close: VMIO object missing"); 242 vm_object_deallocate(vp->v_object); 243 } else 244 vrele(vp); 245 return (error); 246 } 247 248 /* 249 * Package up an I/O request on a vnode into a uio and do it. 250 */ 251 int 252 vn_rdwr(rw, vp, base, len, offset, segflg, ioflg, cred, aresid, p) 253 enum uio_rw rw; 254 struct vnode *vp; 255 caddr_t base; 256 int len; 257 off_t offset; 258 enum uio_seg segflg; 259 int ioflg; 260 struct ucred *cred; 261 int *aresid; 262 struct proc *p; 263 { 264 struct uio auio; 265 struct iovec aiov; 266 int error; 267 268 if ((ioflg & IO_NODELOCKED) == 0) 269 VOP_LOCK(vp); 270 auio.uio_iov = &aiov; 271 auio.uio_iovcnt = 1; 272 aiov.iov_base = base; 273 aiov.iov_len = len; 274 auio.uio_resid = len; 275 auio.uio_offset = offset; 276 auio.uio_segflg = segflg; 277 auio.uio_rw = rw; 278 auio.uio_procp = p; 279 if (rw == UIO_READ) { 280 error = VOP_READ(vp, &auio, ioflg, cred); 281 } else { 282 error = VOP_WRITE(vp, &auio, ioflg, cred); 283 } 284 if (aresid) 285 *aresid = auio.uio_resid; 286 else 287 if (auio.uio_resid && error == 0) 288 error = EIO; 289 if ((ioflg & IO_NODELOCKED) == 0) 290 VOP_UNLOCK(vp); 291 return (error); 292 } 293 294 /* 295 * File table vnode read routine. 296 */ 297 int 298 vn_read(fp, uio, cred) 299 struct file *fp; 300 struct uio *uio; 301 struct ucred *cred; 302 { 303 register struct vnode *vp = (struct vnode *)fp->f_data; 304 int count, error; 305 306 LEASE_CHECK(vp, uio->uio_procp, cred, LEASE_READ); 307 VOP_LOCK(vp); 308 uio->uio_offset = fp->f_offset; 309 count = uio->uio_resid; 310 error = VOP_READ(vp, uio, (fp->f_flag & FNONBLOCK) ? IO_NDELAY : 0, 311 cred); 312 fp->f_offset += count - uio->uio_resid; 313 VOP_UNLOCK(vp); 314 return (error); 315 } 316 317 /* 318 * File table vnode write routine. 319 */ 320 int 321 vn_write(fp, uio, cred) 322 struct file *fp; 323 struct uio *uio; 324 struct ucred *cred; 325 { 326 register struct vnode *vp = (struct vnode *)fp->f_data; 327 int count, error, ioflag = 0; 328 329 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 330 ioflag |= IO_APPEND; 331 if (fp->f_flag & FNONBLOCK) 332 ioflag |= IO_NDELAY; 333 LEASE_CHECK(vp, uio->uio_procp, cred, LEASE_WRITE); 334 VOP_LOCK(vp); 335 uio->uio_offset = fp->f_offset; 336 count = uio->uio_resid; 337 error = VOP_WRITE(vp, uio, ioflag, cred); 338 if (ioflag & IO_APPEND) 339 fp->f_offset = uio->uio_offset; 340 else 341 fp->f_offset += count - uio->uio_resid; 342 VOP_UNLOCK(vp); 343 return (error); 344 } 345 346 /* 347 * File table vnode stat routine. 348 */ 349 int 350 vn_stat(vp, sb, p) 351 struct vnode *vp; 352 register struct stat *sb; 353 struct proc *p; 354 { 355 struct vattr vattr; 356 register struct vattr *vap; 357 int error; 358 u_short mode; 359 360 vap = &vattr; 361 error = VOP_GETATTR(vp, vap, p->p_ucred, p); 362 if (error) 363 return (error); 364 /* 365 * Copy from vattr table 366 */ 367 sb->st_dev = vap->va_fsid; 368 sb->st_ino = vap->va_fileid; 369 mode = vap->va_mode; 370 switch (vp->v_type) { 371 case VREG: 372 mode |= S_IFREG; 373 break; 374 case VDIR: 375 mode |= S_IFDIR; 376 break; 377 case VBLK: 378 mode |= S_IFBLK; 379 break; 380 case VCHR: 381 mode |= S_IFCHR; 382 break; 383 case VLNK: 384 mode |= S_IFLNK; 385 break; 386 case VSOCK: 387 mode |= S_IFSOCK; 388 break; 389 case VFIFO: 390 mode |= S_IFIFO; 391 break; 392 default: 393 return (EBADF); 394 }; 395 sb->st_mode = mode; 396 sb->st_nlink = vap->va_nlink; 397 sb->st_uid = vap->va_uid; 398 sb->st_gid = vap->va_gid; 399 sb->st_rdev = vap->va_rdev; 400 sb->st_size = vap->va_size; 401 sb->st_atimespec = vap->va_atime; 402 sb->st_mtimespec= vap->va_mtime; 403 sb->st_ctimespec = vap->va_ctime; 404 sb->st_blksize = vap->va_blocksize; 405 sb->st_flags = vap->va_flags; 406 sb->st_gen = vap->va_gen; 407 #if (S_BLKSIZE == 512) 408 /* Optimize this case */ 409 sb->st_blocks = vap->va_bytes >> 9; 410 #else 411 sb->st_blocks = vap->va_bytes / S_BLKSIZE; 412 #endif 413 return (0); 414 } 415 416 /* 417 * File table vnode ioctl routine. 418 */ 419 int 420 vn_ioctl(fp, com, data, p) 421 struct file *fp; 422 int com; 423 caddr_t data; 424 struct proc *p; 425 { 426 register struct vnode *vp = ((struct vnode *)fp->f_data); 427 struct vattr vattr; 428 int error; 429 430 switch (vp->v_type) { 431 432 case VREG: 433 case VDIR: 434 if (com == FIONREAD) { 435 error = VOP_GETATTR(vp, &vattr, p->p_ucred, p); 436 if (error) 437 return (error); 438 *(int *)data = vattr.va_size - fp->f_offset; 439 return (0); 440 } 441 if (com == FIONBIO || com == FIOASYNC) /* XXX */ 442 return (0); /* XXX */ 443 /* fall into ... */ 444 445 default: 446 return (ENOTTY); 447 448 case VFIFO: 449 case VCHR: 450 case VBLK: 451 error = VOP_IOCTL(vp, com, data, fp->f_flag, p->p_ucred, p); 452 if (error == 0 && com == TIOCSCTTY) { 453 454 /* Do nothing if reassigning same control tty */ 455 if (p->p_session->s_ttyvp == vp) 456 return (0); 457 458 /* Get rid of reference to old control tty */ 459 if (p->p_session->s_ttyvp) 460 vrele(p->p_session->s_ttyvp); 461 462 p->p_session->s_ttyvp = vp; 463 VREF(vp); 464 } 465 return (error); 466 } 467 } 468 469 /* 470 * File table vnode select routine. 471 */ 472 int 473 vn_select(fp, which, p) 474 struct file *fp; 475 int which; 476 struct proc *p; 477 { 478 479 return (VOP_SELECT(((struct vnode *)fp->f_data), which, fp->f_flag, 480 fp->f_cred, p)); 481 } 482 483 /* 484 * File table vnode close routine. 485 */ 486 int 487 vn_closefile(fp, p) 488 struct file *fp; 489 struct proc *p; 490 { 491 492 return (vn_close(((struct vnode *)fp->f_data), fp->f_flag, 493 fp->f_cred, p)); 494 } 495