vfs_vnops.c revision 1.16
1/* $NetBSD: vfs_vnops.c,v 1.16 1994/11/14 06:01:24 christos 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, fp) 66 register struct nameidata *ndp; 67 int fmode, cmode; 68 struct file *fp; 69{ 70 register struct vnode *vp; 71 register struct proc *p = ndp->ni_cnd.cn_proc; 72 register struct ucred *cred = p->p_ucred; 73 struct vattr vat; 74 struct vattr *vap = &vat; 75 int error; 76 77 if (fmode & O_CREAT) { 78 ndp->ni_cnd.cn_nameiop = CREATE; 79 ndp->ni_cnd.cn_flags = LOCKPARENT | LOCKLEAF; 80 if ((fmode & O_EXCL) == 0) 81 ndp->ni_cnd.cn_flags |= FOLLOW; 82 if (error = namei(ndp)) 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 if (error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp, 90 &ndp->ni_cnd, vap)) 91 return (error); 92 fmode &= ~O_TRUNC; 93 vp = ndp->ni_vp; 94 } else { 95 VOP_ABORTOP(ndp->ni_dvp, &ndp->ni_cnd); 96 if (ndp->ni_dvp == ndp->ni_vp) 97 vrele(ndp->ni_dvp); 98 else 99 vput(ndp->ni_dvp); 100 ndp->ni_dvp = NULL; 101 vp = ndp->ni_vp; 102 if (fmode & O_EXCL) { 103 error = EEXIST; 104 goto bad; 105 } 106 fmode &= ~O_CREAT; 107 } 108 } else { 109 ndp->ni_cnd.cn_nameiop = LOOKUP; 110 ndp->ni_cnd.cn_flags = FOLLOW | LOCKLEAF; 111 if (error = namei(ndp)) 112 return (error); 113 vp = ndp->ni_vp; 114 } 115 if (vp->v_type == VSOCK) { 116 error = EOPNOTSUPP; 117 goto bad; 118 } 119 if ((fmode & O_CREAT) == 0) { 120 if (fmode & FREAD) { 121 if (error = VOP_ACCESS(vp, VREAD, cred, p)) 122 goto bad; 123 } 124 if (fmode & (FWRITE | O_TRUNC)) { 125 if (vp->v_type == VDIR) { 126 error = EISDIR; 127 goto bad; 128 } 129 if ((error = vn_writechk(vp)) || 130 (error = VOP_ACCESS(vp, VWRITE, cred, p))) 131 goto bad; 132 } 133 } 134 if (fmode & O_TRUNC) { 135 VOP_UNLOCK(vp); /* XXX */ 136 LEASE_CHECK(vp, p, cred, LEASE_WRITE); 137 VOP_LOCK(vp); /* XXX */ 138 VATTR_NULL(vap); 139 vap->va_size = 0; 140 if (error = VOP_SETATTR(vp, vap, cred, p)) 141 goto bad; 142 } 143 if (error = VOP_OPEN(vp, fmode, cred, p, fp)) 144 goto bad; 145 if (fmode & FWRITE) 146 vp->v_writecount++; 147 return (0); 148bad: 149 vput(vp); 150 return (error); 151} 152 153/* 154 * Check for write permissions on the specified vnode. 155 * The read-only status of the file system is checked. 156 * Also, prototype text segments cannot be written. 157 */ 158vn_writechk(vp) 159 register struct vnode *vp; 160{ 161 162 /* 163 * Disallow write attempts on read-only file systems; 164 * unless the file is a socket or a block or character 165 * device resident on the file system. 166 */ 167 if (vp->v_mount->mnt_flag & MNT_RDONLY) { 168 switch (vp->v_type) { 169 case VREG: case VDIR: case VLNK: 170 return (EROFS); 171 } 172 } 173 /* 174 * If there's shared text associated with 175 * the vnode, try to free it up once. If 176 * we fail, we can't allow writing. 177 */ 178 if ((vp->v_flag & VTEXT) && !vnode_pager_uncache(vp)) 179 return (ETXTBSY); 180 return (0); 181} 182 183/* 184 * Vnode close call 185 */ 186vn_close(vp, flags, cred, p) 187 register struct vnode *vp; 188 int flags; 189 struct ucred *cred; 190 struct proc *p; 191{ 192 int error; 193 194 if (flags & FWRITE) 195 vp->v_writecount--; 196 error = VOP_CLOSE(vp, flags, cred, p); 197 vrele(vp); 198 return (error); 199} 200 201/* 202 * Package up an I/O request on a vnode into a uio and do it. 203 */ 204vn_rdwr(rw, vp, base, len, offset, segflg, ioflg, cred, aresid, p) 205 enum uio_rw rw; 206 struct vnode *vp; 207 caddr_t base; 208 int len; 209 off_t offset; 210 enum uio_seg segflg; 211 int ioflg; 212 struct ucred *cred; 213 int *aresid; 214 struct proc *p; 215{ 216 struct uio auio; 217 struct iovec aiov; 218 int error; 219 220 if ((ioflg & IO_NODELOCKED) == 0) 221 VOP_LOCK(vp); 222 auio.uio_iov = &aiov; 223 auio.uio_iovcnt = 1; 224 aiov.iov_base = base; 225 aiov.iov_len = len; 226 auio.uio_resid = len; 227 auio.uio_offset = offset; 228 auio.uio_segflg = segflg; 229 auio.uio_rw = rw; 230 auio.uio_procp = p; 231 if (rw == UIO_READ) { 232 error = VOP_READ(vp, &auio, ioflg, cred); 233 } else { 234 error = VOP_WRITE(vp, &auio, ioflg, cred); 235 } 236 if (aresid) 237 *aresid = auio.uio_resid; 238 else 239 if (auio.uio_resid && error == 0) 240 error = EIO; 241 if ((ioflg & IO_NODELOCKED) == 0) 242 VOP_UNLOCK(vp); 243 return (error); 244} 245 246/* 247 * File table vnode read routine. 248 */ 249vn_read(fp, uio, cred) 250 struct file *fp; 251 struct uio *uio; 252 struct ucred *cred; 253{ 254 register struct vnode *vp = (struct vnode *)fp->f_data; 255 int count, error; 256 257 LEASE_CHECK(vp, uio->uio_procp, cred, LEASE_READ); 258 VOP_LOCK(vp); 259 uio->uio_offset = fp->f_offset; 260 count = uio->uio_resid; 261 error = VOP_READ(vp, uio, (fp->f_flag & FNONBLOCK) ? IO_NDELAY : 0, 262 cred); 263 fp->f_offset += count - uio->uio_resid; 264 VOP_UNLOCK(vp); 265 return (error); 266} 267 268/* 269 * File table vnode write routine. 270 */ 271vn_write(fp, uio, cred) 272 struct file *fp; 273 struct uio *uio; 274 struct ucred *cred; 275{ 276 register struct vnode *vp = (struct vnode *)fp->f_data; 277 int count, error, ioflag = 0; 278 279 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 280 ioflag |= IO_APPEND; 281 if (fp->f_flag & FNONBLOCK) 282 ioflag |= IO_NDELAY; 283 LEASE_CHECK(vp, uio->uio_procp, cred, LEASE_WRITE); 284 VOP_LOCK(vp); 285 uio->uio_offset = fp->f_offset; 286 count = uio->uio_resid; 287 error = VOP_WRITE(vp, uio, ioflag, cred); 288 if (ioflag & IO_APPEND) 289 fp->f_offset = uio->uio_offset; 290 else 291 fp->f_offset += count - uio->uio_resid; 292 VOP_UNLOCK(vp); 293 return (error); 294} 295 296/* 297 * File table vnode stat routine. 298 */ 299vn_stat(vp, sb, p) 300 struct vnode *vp; 301 register struct stat *sb; 302 struct proc *p; 303{ 304 struct vattr vattr; 305 register struct vattr *vap; 306 int error; 307 u_short mode; 308 309 vap = &vattr; 310 error = VOP_GETATTR(vp, vap, p->p_ucred, p); 311 if (error) 312 return (error); 313 /* 314 * Copy from vattr table 315 */ 316 sb->st_dev = vap->va_fsid; 317 sb->st_ino = vap->va_fileid; 318 mode = vap->va_mode; 319 switch (vp->v_type) { 320 case VREG: 321 mode |= S_IFREG; 322 break; 323 case VDIR: 324 mode |= S_IFDIR; 325 break; 326 case VBLK: 327 mode |= S_IFBLK; 328 break; 329 case VCHR: 330 mode |= S_IFCHR; 331 break; 332 case VLNK: 333 mode |= S_IFLNK; 334 break; 335 case VSOCK: 336 mode |= S_IFSOCK; 337 break; 338 case VFIFO: 339 mode |= S_IFIFO; 340 break; 341 default: 342 return (EBADF); 343 }; 344 sb->st_mode = mode; 345 sb->st_nlink = vap->va_nlink; 346 sb->st_uid = vap->va_uid; 347 sb->st_gid = vap->va_gid; 348 sb->st_rdev = vap->va_rdev; 349 sb->st_size = vap->va_size; 350 sb->st_atimespec = vap->va_atime; 351 sb->st_mtimespec = vap->va_mtime; 352 sb->st_ctimespec = vap->va_ctime; 353 sb->st_blksize = vap->va_blocksize; 354 sb->st_flags = vap->va_flags; 355 sb->st_gen = vap->va_gen; 356 sb->st_blocks = vap->va_bytes / S_BLKSIZE; 357 return (0); 358} 359 360/* 361 * File table vnode ioctl routine. 362 */ 363vn_ioctl(fp, com, data, p) 364 struct file *fp; 365 u_long com; 366 caddr_t data; 367 struct proc *p; 368{ 369 register struct vnode *vp = ((struct vnode *)fp->f_data); 370 struct vattr vattr; 371 int error; 372 373 switch (vp->v_type) { 374 375 case VREG: 376 case VDIR: 377 if (com == FIONREAD) { 378 if (error = VOP_GETATTR(vp, &vattr, p->p_ucred, p)) 379 return (error); 380 *(int *)data = vattr.va_size - fp->f_offset; 381 return (0); 382 } 383 if (com == FIONBIO || com == FIOASYNC) /* XXX */ 384 return (0); /* XXX */ 385 /* fall into ... */ 386 387 default: 388 return (ENOTTY); 389 390 case VFIFO: 391 case VCHR: 392 case VBLK: 393 error = VOP_IOCTL(vp, com, data, fp->f_flag, p->p_ucred, p); 394 if (error == 0 && com == TIOCSCTTY) { 395 if (p->p_session->s_ttyvp) 396 vrele(p->p_session->s_ttyvp); 397 p->p_session->s_ttyvp = vp; 398 VREF(vp); 399 } 400 return (error); 401 } 402} 403 404/* 405 * File table vnode select routine. 406 */ 407vn_select(fp, which, p) 408 struct file *fp; 409 int which; 410 struct proc *p; 411{ 412 413 return (VOP_SELECT(((struct vnode *)fp->f_data), which, fp->f_flag, 414 fp->f_cred, p)); 415} 416 417/* 418 * File table vnode close routine. 419 */ 420vn_closefile(fp, p) 421 struct file *fp; 422 struct proc *p; 423{ 424 425 return (vn_close(((struct vnode *)fp->f_data), fp->f_flag, 426 fp->f_cred, p)); 427} 428