1 /* $NetBSD: vfs_vnops.c,v 1.21 1996/09/07 12:41:05 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 8.5 (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 #include <sys/poll.h> 56 57 #include <vm/vm.h> 58 59 struct fileops vnops = 60 { vn_read, vn_write, vn_ioctl, vn_poll, vn_closefile }; 61 62 /* 63 * Common code for vnode open operations. 64 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine. 65 */ 66 int 67 vn_open(ndp, fmode, cmode) 68 register struct nameidata *ndp; 69 int fmode, cmode; 70 { 71 register struct vnode *vp; 72 register struct proc *p = ndp->ni_cnd.cn_proc; 73 register struct ucred *cred = p->p_ucred; 74 struct vattr va; 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)) != 0) 83 return (error); 84 if (ndp->ni_vp == NULL) { 85 VATTR_NULL(&va); 86 va.va_type = VREG; 87 va.va_mode = cmode; 88 VOP_LEASE(ndp->ni_dvp, p, cred, LEASE_WRITE); 89 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp, 90 &ndp->ni_cnd, &va); 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 if ((error = namei(ndp)) != 0) 113 return (error); 114 vp = ndp->ni_vp; 115 } 116 if (vp->v_type == VSOCK) { 117 error = EOPNOTSUPP; 118 goto bad; 119 } 120 if ((fmode & O_CREAT) == 0) { 121 if (fmode & FREAD) { 122 if ((error = VOP_ACCESS(vp, VREAD, cred, p)) != 0) 123 goto bad; 124 } 125 if (fmode & (FWRITE | O_TRUNC)) { 126 if (vp->v_type == VDIR) { 127 error = EISDIR; 128 goto bad; 129 } 130 if ((error = vn_writechk(vp)) != 0 || 131 (error = VOP_ACCESS(vp, VWRITE, cred, p)) != 0) 132 goto bad; 133 } 134 } 135 if (fmode & O_TRUNC) { 136 VOP_UNLOCK(vp); /* XXX */ 137 VOP_LEASE(vp, p, cred, LEASE_WRITE); 138 VOP_LOCK(vp); /* XXX */ 139 VATTR_NULL(&va); 140 va.va_size = 0; 141 if ((error = VOP_SETATTR(vp, &va, cred, p)) != 0) 142 goto bad; 143 } 144 if ((error = VOP_OPEN(vp, fmode, cred, p)) != 0) 145 goto bad; 146 if (fmode & FWRITE) 147 vp->v_writecount++; 148 return (0); 149 bad: 150 vput(vp); 151 return (error); 152 } 153 154 /* 155 * Check for write permissions on the specified vnode. 156 * The read-only status of the file system is checked. 157 * Also, prototype text segments cannot be written. 158 */ 159 int 160 vn_writechk(vp) 161 register struct vnode *vp; 162 { 163 164 /* 165 * Disallow write attempts on read-only file systems; 166 * unless the file is a socket or a block or character 167 * device resident on the file system. 168 */ 169 if (vp->v_mount->mnt_flag & MNT_RDONLY) { 170 switch (vp->v_type) { 171 case VREG: case VDIR: case VLNK: 172 return (EROFS); 173 case VNON: case VCHR: case VSOCK: 174 case VFIFO: case VBAD: case VBLK: 175 break; 176 } 177 } 178 /* 179 * If there's shared text associated with 180 * the vnode, try to free it up once. If 181 * we fail, we can't allow writing. 182 */ 183 if ((vp->v_flag & VTEXT) && !vnode_pager_uncache(vp)) 184 return (ETXTBSY); 185 return (0); 186 } 187 188 /* 189 * Vnode close call 190 */ 191 int 192 vn_close(vp, flags, cred, p) 193 register struct vnode *vp; 194 int flags; 195 struct ucred *cred; 196 struct proc *p; 197 { 198 int error; 199 200 if (flags & FWRITE) 201 vp->v_writecount--; 202 error = VOP_CLOSE(vp, flags, cred, p); 203 vrele(vp); 204 return (error); 205 } 206 207 /* 208 * Package up an I/O request on a vnode into a uio and do it. 209 */ 210 int 211 vn_rdwr(rw, vp, base, len, offset, segflg, ioflg, cred, aresid, p) 212 enum uio_rw rw; 213 struct vnode *vp; 214 caddr_t base; 215 int len; 216 off_t offset; 217 enum uio_seg segflg; 218 int ioflg; 219 struct ucred *cred; 220 int *aresid; 221 struct proc *p; 222 { 223 struct uio auio; 224 struct iovec aiov; 225 int error; 226 227 if ((ioflg & IO_NODELOCKED) == 0) 228 VOP_LOCK(vp); 229 auio.uio_iov = &aiov; 230 auio.uio_iovcnt = 1; 231 aiov.iov_base = base; 232 aiov.iov_len = len; 233 auio.uio_resid = len; 234 auio.uio_offset = offset; 235 auio.uio_segflg = segflg; 236 auio.uio_rw = rw; 237 auio.uio_procp = p; 238 if (rw == UIO_READ) { 239 error = VOP_READ(vp, &auio, ioflg, cred); 240 } else { 241 error = VOP_WRITE(vp, &auio, ioflg, cred); 242 } 243 if (aresid) 244 *aresid = auio.uio_resid; 245 else 246 if (auio.uio_resid && error == 0) 247 error = EIO; 248 if ((ioflg & IO_NODELOCKED) == 0) 249 VOP_UNLOCK(vp); 250 return (error); 251 } 252 253 /* 254 * File table vnode read routine. 255 */ 256 int 257 vn_read(fp, uio, cred) 258 struct file *fp; 259 struct uio *uio; 260 struct ucred *cred; 261 { 262 register struct vnode *vp = (struct vnode *)fp->f_data; 263 int count, error; 264 265 VOP_LEASE(vp, uio->uio_procp, cred, LEASE_READ); 266 VOP_LOCK(vp); 267 uio->uio_offset = fp->f_offset; 268 count = uio->uio_resid; 269 error = VOP_READ(vp, uio, (fp->f_flag & FNONBLOCK) ? IO_NDELAY : 0, 270 cred); 271 fp->f_offset += count - uio->uio_resid; 272 VOP_UNLOCK(vp); 273 return (error); 274 } 275 276 /* 277 * File table vnode write routine. 278 */ 279 int 280 vn_write(fp, uio, cred) 281 struct file *fp; 282 struct uio *uio; 283 struct ucred *cred; 284 { 285 register struct vnode *vp = (struct vnode *)fp->f_data; 286 int count, error, ioflag = IO_UNIT; 287 288 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 289 ioflag |= IO_APPEND; 290 if (fp->f_flag & FNONBLOCK) 291 ioflag |= IO_NDELAY; 292 VOP_LEASE(vp, uio->uio_procp, cred, LEASE_WRITE); 293 VOP_LOCK(vp); 294 uio->uio_offset = fp->f_offset; 295 count = uio->uio_resid; 296 error = VOP_WRITE(vp, uio, ioflag, cred); 297 if (ioflag & IO_APPEND) 298 fp->f_offset = uio->uio_offset; 299 else 300 fp->f_offset += count - uio->uio_resid; 301 VOP_UNLOCK(vp); 302 return (error); 303 } 304 305 /* 306 * File table vnode stat routine. 307 */ 308 int 309 vn_stat(vp, sb, p) 310 struct vnode *vp; 311 register struct stat *sb; 312 struct proc *p; 313 { 314 struct vattr va; 315 int error; 316 u_short mode; 317 318 error = VOP_GETATTR(vp, &va, p->p_ucred, p); 319 if (error) 320 return (error); 321 /* 322 * Copy from vattr table 323 */ 324 sb->st_dev = va.va_fsid; 325 sb->st_ino = va.va_fileid; 326 mode = va.va_mode; 327 switch (vp->v_type) { 328 case VREG: 329 mode |= S_IFREG; 330 break; 331 case VDIR: 332 mode |= S_IFDIR; 333 break; 334 case VBLK: 335 mode |= S_IFBLK; 336 break; 337 case VCHR: 338 mode |= S_IFCHR; 339 break; 340 case VLNK: 341 mode |= S_IFLNK; 342 break; 343 case VSOCK: 344 mode |= S_IFSOCK; 345 break; 346 case VFIFO: 347 mode |= S_IFIFO; 348 break; 349 default: 350 return (EBADF); 351 }; 352 sb->st_mode = mode; 353 sb->st_nlink = va.va_nlink; 354 sb->st_uid = va.va_uid; 355 sb->st_gid = va.va_gid; 356 sb->st_rdev = va.va_rdev; 357 sb->st_size = va.va_size; 358 sb->st_atimespec = va.va_atime; 359 sb->st_mtimespec = va.va_mtime; 360 sb->st_ctimespec = va.va_ctime; 361 sb->st_blksize = va.va_blocksize; 362 sb->st_flags = va.va_flags; 363 sb->st_gen = va.va_gen; 364 sb->st_blocks = va.va_bytes / S_BLKSIZE; 365 return (0); 366 } 367 368 /* 369 * File table vnode ioctl routine. 370 */ 371 int 372 vn_ioctl(fp, com, data, p) 373 struct file *fp; 374 u_long com; 375 caddr_t data; 376 struct proc *p; 377 { 378 register struct vnode *vp = ((struct vnode *)fp->f_data); 379 struct vattr vattr; 380 int error; 381 382 switch (vp->v_type) { 383 384 case VREG: 385 case VDIR: 386 if (com == FIONREAD) { 387 error = VOP_GETATTR(vp, &vattr, p->p_ucred, p); 388 if (error) 389 return (error); 390 *(int *)data = vattr.va_size - fp->f_offset; 391 return (0); 392 } 393 if (com == FIONBIO || com == FIOASYNC) /* XXX */ 394 return (0); /* XXX */ 395 /* fall into ... */ 396 397 default: 398 return (ENOTTY); 399 400 case VFIFO: 401 case VCHR: 402 case VBLK: 403 error = VOP_IOCTL(vp, com, data, fp->f_flag, p->p_ucred, p); 404 if (error == 0 && com == TIOCSCTTY) { 405 if (p->p_session->s_ttyvp) 406 vrele(p->p_session->s_ttyvp); 407 p->p_session->s_ttyvp = vp; 408 VREF(vp); 409 } 410 return (error); 411 } 412 } 413 414 /* 415 * File table vnode poll routine. 416 */ 417 int 418 vn_poll(fp, events, p) 419 struct file *fp; 420 int events; 421 struct proc *p; 422 { 423 424 return (VOP_POLL(((struct vnode *)fp->f_data), events, 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