vfs_vnops.c revision 1.14
1/* $NetBSD: vfs_vnops.c,v 1.14 1994/09/18 04:40:47 mycroft Exp $ */ 2 3/* 4 * Copyright (c) 1982, 1986, 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by the University of 23 * California, Berkeley and its contributors. 24 * 4. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 * 40 * @(#)vfs_vnops.c 8.2 (Berkeley) 1/21/94 41 */ 42 43#include <sys/param.h> 44#include <sys/systm.h> 45#include <sys/kernel.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/ioctl.h> 54#include <sys/tty.h> 55 56#include <vm/vm.h> 57 58struct fileops vnops = 59 { vn_read, vn_write, vn_ioctl, vn_select, vn_closefile }; 60 61/* 62 * Common code for vnode open operations. 63 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine. 64 */ 65vn_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 if (error = namei(ndp)) 82 return (error); 83 if (ndp->ni_vp == NULL) { 84 VATTR_NULL(vap); 85 vap->va_type = VREG; 86 vap->va_mode = cmode; 87 LEASE_CHECK(ndp->ni_dvp, p, cred, LEASE_WRITE); 88 if (error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp, 89 &ndp->ni_cnd, vap)) 90 return (error); 91 fmode &= ~O_TRUNC; 92 vp = ndp->ni_vp; 93 } else { 94 VOP_ABORTOP(ndp->ni_dvp, &ndp->ni_cnd); 95 if (ndp->ni_dvp == ndp->ni_vp) 96 vrele(ndp->ni_dvp); 97 else 98 vput(ndp->ni_dvp); 99 ndp->ni_dvp = NULL; 100 vp = ndp->ni_vp; 101 if (fmode & O_EXCL) { 102 error = EEXIST; 103 goto bad; 104 } 105 fmode &= ~O_CREAT; 106 } 107 } else { 108 ndp->ni_cnd.cn_nameiop = LOOKUP; 109 ndp->ni_cnd.cn_flags = FOLLOW | LOCKLEAF; 110 if (error = namei(ndp)) 111 return (error); 112 vp = ndp->ni_vp; 113 } 114 if (vp->v_type == VSOCK) { 115 error = EOPNOTSUPP; 116 goto bad; 117 } 118 if ((fmode & O_CREAT) == 0) { 119 if (fmode & FREAD) { 120 if (error = VOP_ACCESS(vp, VREAD, cred, p)) 121 goto bad; 122 } 123 if (fmode & (FWRITE | O_TRUNC)) { 124 if (vp->v_type == VDIR) { 125 error = EISDIR; 126 goto bad; 127 } 128 if ((error = vn_writechk(vp)) || 129 (error = VOP_ACCESS(vp, VWRITE, cred, p))) 130 goto bad; 131 } 132 } 133 if (fmode & O_TRUNC) { 134 VOP_UNLOCK(vp); /* XXX */ 135 LEASE_CHECK(vp, p, cred, LEASE_WRITE); 136 VOP_LOCK(vp); /* XXX */ 137 VATTR_NULL(vap); 138 vap->va_size = 0; 139 if (error = VOP_SETATTR(vp, vap, cred, p)) 140 goto bad; 141 } 142 if (error = VOP_OPEN(vp, fmode, cred, p)) 143 goto bad; 144 if (fmode & FWRITE) 145 vp->v_writecount++; 146 return (0); 147bad: 148 vput(vp); 149 return (error); 150} 151 152/* 153 * Check for write permissions on the specified vnode. 154 * The read-only status of the file system is checked. 155 * Also, prototype text segments cannot be written. 156 */ 157vn_writechk(vp) 158 register struct vnode *vp; 159{ 160 161 /* 162 * Disallow write attempts on read-only file systems; 163 * unless the file is a socket or a block or character 164 * device resident on the file system. 165 */ 166 if (vp->v_mount->mnt_flag & MNT_RDONLY) { 167 switch (vp->v_type) { 168 case VREG: case VDIR: case VLNK: 169 return (EROFS); 170 } 171 } 172 /* 173 * If there's shared text associated with 174 * the vnode, try to free it up once. If 175 * we fail, we can't allow writing. 176 */ 177 if ((vp->v_flag & VTEXT) && !vnode_pager_uncache(vp)) 178 return (ETXTBSY); 179 return (0); 180} 181 182/* 183 * Vnode close call 184 */ 185vn_close(vp, flags, cred, p) 186 register struct vnode *vp; 187 int flags; 188 struct ucred *cred; 189 struct proc *p; 190{ 191 int error; 192 193 if (flags & FWRITE) 194 vp->v_writecount--; 195 error = VOP_CLOSE(vp, flags, cred, p); 196 vrele(vp); 197 return (error); 198} 199 200/* 201 * Package up an I/O request on a vnode into a uio and do it. 202 */ 203vn_rdwr(rw, vp, base, len, offset, segflg, ioflg, cred, aresid, p) 204 enum uio_rw rw; 205 struct vnode *vp; 206 caddr_t base; 207 int len; 208 off_t offset; 209 enum uio_seg segflg; 210 int ioflg; 211 struct ucred *cred; 212 int *aresid; 213 struct proc *p; 214{ 215 struct uio auio; 216 struct iovec aiov; 217 int error; 218 219 if ((ioflg & IO_NODELOCKED) == 0) 220 VOP_LOCK(vp); 221 auio.uio_iov = &aiov; 222 auio.uio_iovcnt = 1; 223 aiov.iov_base = base; 224 aiov.iov_len = len; 225 auio.uio_resid = len; 226 auio.uio_offset = offset; 227 auio.uio_segflg = segflg; 228 auio.uio_rw = rw; 229 auio.uio_procp = p; 230 if (rw == UIO_READ) { 231 error = VOP_READ(vp, &auio, ioflg, cred); 232 } else { 233 error = VOP_WRITE(vp, &auio, ioflg, cred); 234 } 235 if (aresid) 236 *aresid = auio.uio_resid; 237 else 238 if (auio.uio_resid && error == 0) 239 error = EIO; 240 if ((ioflg & IO_NODELOCKED) == 0) 241 VOP_UNLOCK(vp); 242 return (error); 243} 244 245/* 246 * File table vnode read routine. 247 */ 248vn_read(fp, uio, cred) 249 struct file *fp; 250 struct uio *uio; 251 struct ucred *cred; 252{ 253 register struct vnode *vp = (struct vnode *)fp->f_data; 254 int count, error; 255 256 LEASE_CHECK(vp, uio->uio_procp, cred, LEASE_READ); 257 VOP_LOCK(vp); 258 uio->uio_offset = fp->f_offset; 259 count = uio->uio_resid; 260 error = VOP_READ(vp, uio, (fp->f_flag & FNONBLOCK) ? IO_NDELAY : 0, 261 cred); 262 fp->f_offset += count - uio->uio_resid; 263 VOP_UNLOCK(vp); 264 return (error); 265} 266 267/* 268 * File table vnode write routine. 269 */ 270vn_write(fp, uio, cred) 271 struct file *fp; 272 struct uio *uio; 273 struct ucred *cred; 274{ 275 register struct vnode *vp = (struct vnode *)fp->f_data; 276 int count, error, ioflag = 0; 277 278 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 279 ioflag |= IO_APPEND; 280 if (fp->f_flag & FNONBLOCK) 281 ioflag |= IO_NDELAY; 282 LEASE_CHECK(vp, uio->uio_procp, cred, LEASE_WRITE); 283 VOP_LOCK(vp); 284 uio->uio_offset = fp->f_offset; 285 count = uio->uio_resid; 286 error = VOP_WRITE(vp, uio, ioflag, cred); 287 if (ioflag & IO_APPEND) 288 fp->f_offset = uio->uio_offset; 289 else 290 fp->f_offset += count - uio->uio_resid; 291 VOP_UNLOCK(vp); 292 return (error); 293} 294 295/* 296 * File table vnode stat routine. 297 */ 298vn_stat(vp, sb, p) 299 struct vnode *vp; 300 register struct stat *sb; 301 struct proc *p; 302{ 303 struct vattr vattr; 304 register struct vattr *vap; 305 int error; 306 u_short mode; 307 308 vap = &vattr; 309 error = VOP_GETATTR(vp, vap, p->p_ucred, p); 310 if (error) 311 return (error); 312 /* 313 * Copy from vattr table 314 */ 315 sb->st_dev = vap->va_fsid; 316 sb->st_ino = vap->va_fileid; 317 mode = vap->va_mode; 318 switch (vp->v_type) { 319 case VREG: 320 mode |= S_IFREG; 321 break; 322 case VDIR: 323 mode |= S_IFDIR; 324 break; 325 case VBLK: 326 mode |= S_IFBLK; 327 break; 328 case VCHR: 329 mode |= S_IFCHR; 330 break; 331 case VLNK: 332 mode |= S_IFLNK; 333 break; 334 case VSOCK: 335 mode |= S_IFSOCK; 336 break; 337 case VFIFO: 338 mode |= S_IFIFO; 339 break; 340 default: 341 return (EBADF); 342 }; 343 sb->st_mode = mode; 344 sb->st_nlink = vap->va_nlink; 345 sb->st_uid = vap->va_uid; 346 sb->st_gid = vap->va_gid; 347 sb->st_rdev = vap->va_rdev; 348 sb->st_size = vap->va_size; 349 sb->st_atimespec = vap->va_atime; 350 sb->st_mtimespec = vap->va_mtime; 351 sb->st_ctimespec = vap->va_ctime; 352 sb->st_blksize = vap->va_blocksize; 353 sb->st_flags = vap->va_flags; 354 sb->st_gen = vap->va_gen; 355 sb->st_blocks = vap->va_bytes / S_BLKSIZE; 356 return (0); 357} 358 359/* 360 * File table vnode ioctl routine. 361 */ 362vn_ioctl(fp, com, data, p) 363 struct file *fp; 364 int com; 365 caddr_t data; 366 struct proc *p; 367{ 368 register struct vnode *vp = ((struct vnode *)fp->f_data); 369 struct vattr vattr; 370 int error; 371 372 switch (vp->v_type) { 373 374 case VREG: 375 case VDIR: 376 if (com == FIONREAD) { 377 if (error = VOP_GETATTR(vp, &vattr, p->p_ucred, p)) 378 return (error); 379 *(int *)data = vattr.va_size - fp->f_offset; 380 return (0); 381 } 382 if (com == FIONBIO || com == FIOASYNC) /* XXX */ 383 return (0); /* XXX */ 384 /* fall into ... */ 385 386 default: 387 return (ENOTTY); 388 389 case VFIFO: 390 case VCHR: 391 case VBLK: 392 error = VOP_IOCTL(vp, com, data, fp->f_flag, p->p_ucred, p); 393 if (error == 0 && com == TIOCSCTTY) { 394 if (p->p_session->s_ttyvp) 395 vrele(p->p_session->s_ttyvp); 396 p->p_session->s_ttyvp = vp; 397 VREF(vp); 398 } 399 return (error); 400 } 401} 402 403/* 404 * File table vnode select routine. 405 */ 406vn_select(fp, which, p) 407 struct file *fp; 408 int which; 409 struct proc *p; 410{ 411 412 return (VOP_SELECT(((struct vnode *)fp->f_data), which, fp->f_flag, 413 fp->f_cred, p)); 414} 415 416/* 417 * File table vnode close routine. 418 */ 419vn_closefile(fp, p) 420 struct file *fp; 421 struct proc *p; 422{ 423 424 return (vn_close(((struct vnode *)fp->f_data), fp->f_flag, 425 fp->f_cred, p)); 426} 427