1 /* $OpenBSD: vfs_vnops.c,v 1.33 2001/07/16 18:25:43 millert Exp $ */ 2 /* $NetBSD: vfs_vnops.c,v 1.20 1996/02/04 02:18:41 christos Exp $ */ 3 4 /* 5 * Copyright (c) 1982, 1986, 1989, 1993 6 * The Regents of the University of California. All rights reserved. 7 * (c) UNIX System Laboratories, Inc. 8 * All or some portions of this file are derived from material licensed 9 * to the University of California by American Telephone and Telegraph 10 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 11 * the permission of UNIX System Laboratories, Inc. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 3. All advertising materials mentioning features or use of this software 22 * must display the following acknowledgement: 23 * This product includes software developed by the University of 24 * California, Berkeley and its contributors. 25 * 4. Neither the name of the University nor the names of its contributors 26 * may be used to endorse or promote products derived from this software 27 * without specific prior written permission. 28 * 29 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 32 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 39 * SUCH DAMAGE. 40 * 41 * @(#)vfs_vnops.c 8.5 (Berkeley) 12/8/94 42 */ 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/kernel.h> 47 #include <sys/file.h> 48 #include <sys/stat.h> 49 #include <sys/buf.h> 50 #include <sys/proc.h> 51 #include <sys/mount.h> 52 #include <sys/namei.h> 53 #include <sys/vnode.h> 54 #include <sys/ioctl.h> 55 #include <sys/tty.h> 56 #include <sys/cdio.h> 57 58 #include <vm/vm.h> 59 60 #include <uvm/uvm_extern.h> 61 62 int vn_read __P((struct file *fp, off_t *off, struct uio *uio, 63 struct ucred *cred)); 64 int vn_write __P((struct file *fp, off_t *off, struct uio *uio, 65 struct ucred *cred)); 66 int vn_select __P((struct file *fp, int which, struct proc *p)); 67 int vn_kqfilter __P((struct file *fp, struct knote *kn)); 68 int vn_closefile __P((struct file *fp, struct proc *p)); 69 int vn_ioctl __P((struct file *fp, u_long com, caddr_t data, 70 struct proc *p)); 71 72 struct fileops vnops = 73 { vn_read, vn_write, vn_ioctl, vn_select, vn_kqfilter, vn_statfile, 74 vn_closefile }; 75 76 /* 77 * Common code for vnode open operations. 78 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine. 79 */ 80 int 81 vn_open(ndp, fmode, cmode) 82 register struct nameidata *ndp; 83 int fmode, cmode; 84 { 85 register struct vnode *vp; 86 register struct proc *p = ndp->ni_cnd.cn_proc; 87 register struct ucred *cred = p->p_ucred; 88 struct vattr va; 89 int error; 90 91 if ((fmode & (FREAD|FWRITE)) == 0) 92 return (EINVAL); 93 if ((fmode & (O_TRUNC | FWRITE)) == O_TRUNC) 94 return (EINVAL); 95 if (fmode & O_CREAT) { 96 ndp->ni_cnd.cn_nameiop = CREATE; 97 ndp->ni_cnd.cn_flags = LOCKPARENT | LOCKLEAF; 98 if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0) 99 ndp->ni_cnd.cn_flags |= FOLLOW; 100 if ((error = namei(ndp)) != 0) 101 return (error); 102 103 if (ndp->ni_vp == NULL) { 104 VATTR_NULL(&va); 105 va.va_type = VREG; 106 va.va_mode = cmode; 107 VOP_LEASE(ndp->ni_dvp, p, cred, LEASE_WRITE); 108 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp, 109 &ndp->ni_cnd, &va); 110 if (error) 111 return (error); 112 fmode &= ~O_TRUNC; 113 vp = ndp->ni_vp; 114 } else { 115 VOP_ABORTOP(ndp->ni_dvp, &ndp->ni_cnd); 116 if (ndp->ni_dvp == ndp->ni_vp) 117 vrele(ndp->ni_dvp); 118 else 119 vput(ndp->ni_dvp); 120 ndp->ni_dvp = NULL; 121 vp = ndp->ni_vp; 122 if (fmode & O_EXCL) { 123 error = EEXIST; 124 goto bad; 125 } 126 fmode &= ~O_CREAT; 127 } 128 } else { 129 ndp->ni_cnd.cn_nameiop = LOOKUP; 130 ndp->ni_cnd.cn_flags = 131 ((fmode & O_NOFOLLOW) ? NOFOLLOW : FOLLOW) | LOCKLEAF; 132 if ((error = namei(ndp)) != 0) 133 return (error); 134 vp = ndp->ni_vp; 135 } 136 if (vp->v_type == VSOCK) { 137 error = EOPNOTSUPP; 138 goto bad; 139 } 140 if (vp->v_type == VLNK) { 141 error = EMLINK; 142 goto bad; 143 } 144 if ((fmode & O_CREAT) == 0) { 145 if (fmode & FREAD) { 146 if ((error = VOP_ACCESS(vp, VREAD, cred, p)) != 0) 147 goto bad; 148 } 149 if (fmode & FWRITE) { 150 if (vp->v_type == VDIR) { 151 error = EISDIR; 152 goto bad; 153 } 154 if ((error = vn_writechk(vp)) != 0 || 155 (error = VOP_ACCESS(vp, VWRITE, cred, p)) != 0) 156 goto bad; 157 } 158 } 159 if ((fmode & O_TRUNC) && vp->v_type == VREG) { 160 VOP_UNLOCK(vp, 0, p); /* XXX */ 161 VOP_LEASE(vp, p, cred, LEASE_WRITE); 162 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); /* XXX */ 163 VATTR_NULL(&va); 164 va.va_size = 0; 165 if ((error = VOP_SETATTR(vp, &va, cred, p)) != 0) 166 goto bad; 167 } 168 if ((error = VOP_OPEN(vp, fmode, cred, p)) != 0) 169 goto bad; 170 if (fmode & FWRITE) 171 vp->v_writecount++; 172 return (0); 173 bad: 174 vput(vp); 175 return (error); 176 } 177 178 /* 179 * Check for write permissions on the specified vnode. 180 * Prototype text segments cannot be written. 181 */ 182 int 183 vn_writechk(vp) 184 register struct vnode *vp; 185 { 186 187 /* 188 * Disallow write attempts on read-only file systems; 189 * unless the file is a socket or a block or character 190 * device resident on the file system. 191 */ 192 if (vp->v_mount->mnt_flag & MNT_RDONLY) { 193 switch (vp->v_type) { 194 case VREG: case VDIR: case VLNK: 195 return (EROFS); 196 case VNON: case VCHR: case VSOCK: 197 case VFIFO: case VBAD: case VBLK: 198 break; 199 } 200 } 201 /* 202 * If there's shared text associated with 203 * the vnode, try to free it up once. If 204 * we fail, we can't allow writing. 205 */ 206 if ((vp->v_flag & VTEXT) && !uvm_vnp_uncache(vp)) 207 return (ETXTBSY); 208 209 return (0); 210 } 211 212 /* 213 * Vnode close call 214 */ 215 int 216 vn_close(vp, flags, cred, p) 217 register struct vnode *vp; 218 int flags; 219 struct ucred *cred; 220 struct proc *p; 221 { 222 int error; 223 224 if (flags & FWRITE) 225 vp->v_writecount--; 226 error = VOP_CLOSE(vp, flags, cred, p); 227 vrele(vp); 228 return (error); 229 } 230 231 /* 232 * Package up an I/O request on a vnode into a uio and do it. 233 */ 234 int 235 vn_rdwr(rw, vp, base, len, offset, segflg, ioflg, cred, aresid, p) 236 enum uio_rw rw; 237 struct vnode *vp; 238 caddr_t base; 239 int len; 240 off_t offset; 241 enum uio_seg segflg; 242 int ioflg; 243 struct ucred *cred; 244 size_t *aresid; 245 struct proc *p; 246 { 247 struct uio auio; 248 struct iovec aiov; 249 int error; 250 251 if ((ioflg & IO_NODELOCKED) == 0) 252 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); 253 auio.uio_iov = &aiov; 254 auio.uio_iovcnt = 1; 255 aiov.iov_base = base; 256 aiov.iov_len = len; 257 auio.uio_resid = len; 258 auio.uio_offset = offset; 259 auio.uio_segflg = segflg; 260 auio.uio_rw = rw; 261 auio.uio_procp = p; 262 if (rw == UIO_READ) { 263 error = VOP_READ(vp, &auio, ioflg, cred); 264 } else { 265 error = VOP_WRITE(vp, &auio, ioflg, cred); 266 } 267 if (aresid) 268 *aresid = auio.uio_resid; 269 else 270 if (auio.uio_resid && error == 0) 271 error = EIO; 272 if ((ioflg & IO_NODELOCKED) == 0) 273 VOP_UNLOCK(vp, 0, p); 274 return (error); 275 } 276 277 /* 278 * File table vnode read routine. 279 */ 280 int 281 vn_read(fp, poff, uio, cred) 282 struct file *fp; 283 off_t *poff; 284 struct uio *uio; 285 struct ucred *cred; 286 { 287 register struct vnode *vp = (struct vnode *)fp->f_data; 288 int error = 0; 289 size_t count; 290 struct proc *p = uio->uio_procp; 291 292 VOP_LEASE(vp, uio->uio_procp, cred, LEASE_READ); 293 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); 294 uio->uio_offset = *poff; 295 count = uio->uio_resid; 296 if (vp->v_type != VDIR) 297 error = VOP_READ(vp, uio, 298 (fp->f_flag & FNONBLOCK) ? IO_NDELAY : 0, cred); 299 *poff += count - uio->uio_resid; 300 VOP_UNLOCK(vp, 0, p); 301 return (error); 302 } 303 304 /* 305 * File table vnode write routine. 306 */ 307 int 308 vn_write(fp, poff, uio, cred) 309 struct file *fp; 310 off_t *poff; 311 struct uio *uio; 312 struct ucred *cred; 313 { 314 register struct vnode *vp = (struct vnode *)fp->f_data; 315 struct proc *p = uio->uio_procp; 316 int error, ioflag = IO_UNIT; 317 size_t count; 318 319 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 320 ioflag |= IO_APPEND; 321 if (fp->f_flag & FNONBLOCK) 322 ioflag |= IO_NDELAY; 323 if ((fp->f_flag & FFSYNC) || 324 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS))) 325 ioflag |= IO_SYNC; 326 VOP_LEASE(vp, uio->uio_procp, cred, LEASE_WRITE); 327 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); 328 uio->uio_offset = *poff; 329 count = uio->uio_resid; 330 error = VOP_WRITE(vp, uio, ioflag, cred); 331 if (ioflag & IO_APPEND) 332 *poff = uio->uio_offset; 333 else 334 *poff += count - uio->uio_resid; 335 VOP_UNLOCK(vp, 0, p); 336 return (error); 337 } 338 339 /* 340 * File table wrapper for vn_stat 341 */ 342 int 343 vn_statfile(fp, sb, p) 344 struct file *fp; 345 struct stat *sb; 346 struct proc *p; 347 { 348 struct vnode *vp = (struct vnode *)fp->f_data; 349 350 return vn_stat(vp, sb, p); 351 } 352 353 /* 354 * vnode stat routine. 355 */ 356 int 357 vn_stat(vp, sb, p) 358 struct vnode *vp; 359 register struct stat *sb; 360 struct proc *p; 361 { 362 struct vattr va; 363 int error; 364 u_short mode; 365 366 error = VOP_GETATTR(vp, &va, p->p_ucred, p); 367 if (error) 368 return (error); 369 /* 370 * Copy from vattr table 371 */ 372 sb->st_dev = va.va_fsid; 373 sb->st_ino = va.va_fileid; 374 mode = va.va_mode; 375 switch (vp->v_type) { 376 case VREG: 377 mode |= S_IFREG; 378 break; 379 case VDIR: 380 mode |= S_IFDIR; 381 break; 382 case VBLK: 383 mode |= S_IFBLK; 384 break; 385 case VCHR: 386 mode |= S_IFCHR; 387 break; 388 case VLNK: 389 mode |= S_IFLNK; 390 break; 391 case VSOCK: 392 mode |= S_IFSOCK; 393 break; 394 case VFIFO: 395 mode |= S_IFIFO; 396 break; 397 default: 398 return (EBADF); 399 } 400 sb->st_mode = mode; 401 sb->st_nlink = va.va_nlink; 402 sb->st_uid = va.va_uid; 403 sb->st_gid = va.va_gid; 404 sb->st_rdev = va.va_rdev; 405 sb->st_size = va.va_size; 406 sb->st_atimespec = va.va_atime; 407 sb->st_mtimespec = va.va_mtime; 408 sb->st_ctimespec = va.va_ctime; 409 sb->st_blksize = va.va_blocksize; 410 sb->st_flags = va.va_flags; 411 sb->st_gen = va.va_gen; 412 sb->st_blocks = va.va_bytes / S_BLKSIZE; 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 u_long 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 == FIBMAP) 442 return VOP_IOCTL(vp, com, data, fp->f_flag, 443 p->p_ucred, p); 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 if (p->p_session->s_ttyvp) 457 vrele(p->p_session->s_ttyvp); 458 p->p_session->s_ttyvp = vp; 459 VREF(vp); 460 } 461 return (error); 462 } 463 } 464 465 /* 466 * File table vnode select routine. 467 */ 468 int 469 vn_select(fp, which, p) 470 struct file *fp; 471 int which; 472 struct proc *p; 473 { 474 475 return (VOP_SELECT(((struct vnode *)fp->f_data), which, fp->f_flag, 476 fp->f_cred, p)); 477 } 478 479 /* 480 * Check that the vnode is still valid, and if so 481 * acquire requested lock. 482 */ 483 int 484 vn_lock(vp, flags, p) 485 struct vnode *vp; 486 int flags; 487 struct proc *p; 488 { 489 int error; 490 491 do { 492 if ((flags & LK_INTERLOCK) == 0) 493 simple_lock(&vp->v_interlock); 494 if (vp->v_flag & VXLOCK) { 495 vp->v_flag |= VXWANT; 496 simple_unlock(&vp->v_interlock); 497 tsleep((caddr_t)vp, PINOD, "vn_lock", 0); 498 error = ENOENT; 499 } else { 500 error = VOP_LOCK(vp, flags | LK_INTERLOCK | LK_CANRECURSE, p); 501 if (error == 0) 502 return (error); 503 } 504 flags &= ~LK_INTERLOCK; 505 } while (flags & LK_RETRY); 506 return (error); 507 } 508 509 /* 510 * File table vnode close routine. 511 */ 512 int 513 vn_closefile(fp, p) 514 struct file *fp; 515 struct proc *p; 516 { 517 518 return (vn_close(((struct vnode *)fp->f_data), fp->f_flag, 519 fp->f_cred, p)); 520 } 521 522 /*ARGSUSED*/ 523 int 524 vn_kqfilter(struct file *fp, struct knote *kn) 525 { 526 return (VOP_KQFILTER(((struct vnode *)fp->f_data), kn)); 527 } 528