vfs_vnops.c revision 1.20
1 /* $NetBSD: vfs_vnops.c,v 1.20 1996/02/04 02:18:41 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 8.5 (Berkeley) 12/8/94 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 58 struct 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 */ 65 int 66 vn_open(ndp, fmode, cmode) 67 register struct nameidata *ndp; 68 int fmode, cmode; 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 va; 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)) != 0) 82 return (error); 83 if (ndp->ni_vp == NULL) { 84 VATTR_NULL(&va); 85 va.va_type = VREG; 86 va.va_mode = cmode; 87 VOP_LEASE(ndp->ni_dvp, p, cred, LEASE_WRITE); 88 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp, 89 &ndp->ni_cnd, &va); 90 if (error) 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)) != 0) 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)) != 0) 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)) != 0 || 130 (error = VOP_ACCESS(vp, VWRITE, cred, p)) != 0) 131 goto bad; 132 } 133 } 134 if (fmode & O_TRUNC) { 135 VOP_UNLOCK(vp); /* XXX */ 136 VOP_LEASE(vp, p, cred, LEASE_WRITE); 137 VOP_LOCK(vp); /* XXX */ 138 VATTR_NULL(&va); 139 va.va_size = 0; 140 if ((error = VOP_SETATTR(vp, &va, cred, p)) != 0) 141 goto bad; 142 } 143 if ((error = VOP_OPEN(vp, fmode, cred, p)) != 0) 144 goto bad; 145 if (fmode & FWRITE) 146 vp->v_writecount++; 147 return (0); 148 bad: 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 */ 158 int 159 vn_writechk(vp) 160 register struct vnode *vp; 161 { 162 163 /* 164 * Disallow write attempts on read-only file systems; 165 * unless the file is a socket or a block or character 166 * device resident on the file system. 167 */ 168 if (vp->v_mount->mnt_flag & MNT_RDONLY) { 169 switch (vp->v_type) { 170 case VREG: case VDIR: case VLNK: 171 return (EROFS); 172 case VNON: case VCHR: case VSOCK: 173 case VFIFO: case VBAD: case VBLK: 174 break; 175 } 176 } 177 /* 178 * If there's shared text associated with 179 * the vnode, try to free it up once. If 180 * we fail, we can't allow writing. 181 */ 182 if ((vp->v_flag & VTEXT) && !vnode_pager_uncache(vp)) 183 return (ETXTBSY); 184 return (0); 185 } 186 187 /* 188 * Vnode close call 189 */ 190 int 191 vn_close(vp, flags, cred, p) 192 register struct vnode *vp; 193 int flags; 194 struct ucred *cred; 195 struct proc *p; 196 { 197 int error; 198 199 if (flags & FWRITE) 200 vp->v_writecount--; 201 error = VOP_CLOSE(vp, flags, cred, p); 202 vrele(vp); 203 return (error); 204 } 205 206 /* 207 * Package up an I/O request on a vnode into a uio and do it. 208 */ 209 int 210 vn_rdwr(rw, vp, base, len, offset, segflg, ioflg, cred, aresid, p) 211 enum uio_rw rw; 212 struct vnode *vp; 213 caddr_t base; 214 int len; 215 off_t offset; 216 enum uio_seg segflg; 217 int ioflg; 218 struct ucred *cred; 219 int *aresid; 220 struct proc *p; 221 { 222 struct uio auio; 223 struct iovec aiov; 224 int error; 225 226 if ((ioflg & IO_NODELOCKED) == 0) 227 VOP_LOCK(vp); 228 auio.uio_iov = &aiov; 229 auio.uio_iovcnt = 1; 230 aiov.iov_base = base; 231 aiov.iov_len = len; 232 auio.uio_resid = len; 233 auio.uio_offset = offset; 234 auio.uio_segflg = segflg; 235 auio.uio_rw = rw; 236 auio.uio_procp = p; 237 if (rw == UIO_READ) { 238 error = VOP_READ(vp, &auio, ioflg, cred); 239 } else { 240 error = VOP_WRITE(vp, &auio, ioflg, cred); 241 } 242 if (aresid) 243 *aresid = auio.uio_resid; 244 else 245 if (auio.uio_resid && error == 0) 246 error = EIO; 247 if ((ioflg & IO_NODELOCKED) == 0) 248 VOP_UNLOCK(vp); 249 return (error); 250 } 251 252 /* 253 * File table vnode read routine. 254 */ 255 int 256 vn_read(fp, uio, cred) 257 struct file *fp; 258 struct uio *uio; 259 struct ucred *cred; 260 { 261 register struct vnode *vp = (struct vnode *)fp->f_data; 262 int count, error; 263 264 VOP_LEASE(vp, uio->uio_procp, cred, LEASE_READ); 265 VOP_LOCK(vp); 266 uio->uio_offset = fp->f_offset; 267 count = uio->uio_resid; 268 error = VOP_READ(vp, uio, (fp->f_flag & FNONBLOCK) ? IO_NDELAY : 0, 269 cred); 270 fp->f_offset += count - uio->uio_resid; 271 VOP_UNLOCK(vp); 272 return (error); 273 } 274 275 /* 276 * File table vnode write routine. 277 */ 278 int 279 vn_write(fp, uio, cred) 280 struct file *fp; 281 struct uio *uio; 282 struct ucred *cred; 283 { 284 register struct vnode *vp = (struct vnode *)fp->f_data; 285 int count, error, ioflag = IO_UNIT; 286 287 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 288 ioflag |= IO_APPEND; 289 if (fp->f_flag & FNONBLOCK) 290 ioflag |= IO_NDELAY; 291 VOP_LEASE(vp, uio->uio_procp, cred, LEASE_WRITE); 292 VOP_LOCK(vp); 293 uio->uio_offset = fp->f_offset; 294 count = uio->uio_resid; 295 error = VOP_WRITE(vp, uio, ioflag, cred); 296 if (ioflag & IO_APPEND) 297 fp->f_offset = uio->uio_offset; 298 else 299 fp->f_offset += count - uio->uio_resid; 300 VOP_UNLOCK(vp); 301 return (error); 302 } 303 304 /* 305 * File table vnode stat routine. 306 */ 307 int 308 vn_stat(vp, sb, p) 309 struct vnode *vp; 310 register struct stat *sb; 311 struct proc *p; 312 { 313 struct vattr va; 314 int error; 315 u_short mode; 316 317 error = VOP_GETATTR(vp, &va, p->p_ucred, p); 318 if (error) 319 return (error); 320 /* 321 * Copy from vattr table 322 */ 323 sb->st_dev = va.va_fsid; 324 sb->st_ino = va.va_fileid; 325 mode = va.va_mode; 326 switch (vp->v_type) { 327 case VREG: 328 mode |= S_IFREG; 329 break; 330 case VDIR: 331 mode |= S_IFDIR; 332 break; 333 case VBLK: 334 mode |= S_IFBLK; 335 break; 336 case VCHR: 337 mode |= S_IFCHR; 338 break; 339 case VLNK: 340 mode |= S_IFLNK; 341 break; 342 case VSOCK: 343 mode |= S_IFSOCK; 344 break; 345 case VFIFO: 346 mode |= S_IFIFO; 347 break; 348 default: 349 return (EBADF); 350 }; 351 sb->st_mode = mode; 352 sb->st_nlink = va.va_nlink; 353 sb->st_uid = va.va_uid; 354 sb->st_gid = va.va_gid; 355 sb->st_rdev = va.va_rdev; 356 sb->st_size = va.va_size; 357 sb->st_atimespec = va.va_atime; 358 sb->st_mtimespec = va.va_mtime; 359 sb->st_ctimespec = va.va_ctime; 360 sb->st_blksize = va.va_blocksize; 361 sb->st_flags = va.va_flags; 362 sb->st_gen = va.va_gen; 363 sb->st_blocks = va.va_bytes / S_BLKSIZE; 364 return (0); 365 } 366 367 /* 368 * File table vnode ioctl routine. 369 */ 370 int 371 vn_ioctl(fp, com, data, p) 372 struct file *fp; 373 u_long com; 374 caddr_t data; 375 struct proc *p; 376 { 377 register struct vnode *vp = ((struct vnode *)fp->f_data); 378 struct vattr vattr; 379 int error; 380 381 switch (vp->v_type) { 382 383 case VREG: 384 case VDIR: 385 if (com == FIONREAD) { 386 error = VOP_GETATTR(vp, &vattr, p->p_ucred, p); 387 if (error) 388 return (error); 389 *(int *)data = vattr.va_size - fp->f_offset; 390 return (0); 391 } 392 if (com == FIONBIO || com == FIOASYNC) /* XXX */ 393 return (0); /* XXX */ 394 /* fall into ... */ 395 396 default: 397 return (ENOTTY); 398 399 case VFIFO: 400 case VCHR: 401 case VBLK: 402 error = VOP_IOCTL(vp, com, data, fp->f_flag, p->p_ucred, p); 403 if (error == 0 && com == TIOCSCTTY) { 404 if (p->p_session->s_ttyvp) 405 vrele(p->p_session->s_ttyvp); 406 p->p_session->s_ttyvp = vp; 407 VREF(vp); 408 } 409 return (error); 410 } 411 } 412 413 /* 414 * File table vnode select routine. 415 */ 416 int 417 vn_select(fp, which, p) 418 struct file *fp; 419 int which; 420 struct proc *p; 421 { 422 423 return (VOP_SELECT(((struct vnode *)fp->f_data), which, fp->f_flag, 424 fp->f_cred, p)); 425 } 426 427 /* 428 * File table vnode close routine. 429 */ 430 int 431 vn_closefile(fp, p) 432 struct file *fp; 433 struct proc *p; 434 { 435 436 return (vn_close(((struct vnode *)fp->f_data), fp->f_flag, 437 fp->f_cred, p)); 438 } 439
Indexes created Sat Sep 20 22:09:52 GMT 2025