vfs_vnops.c revision 1.11
1 /* 2 * Copyright (c) 1982, 1986, 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * from: @(#)vfs_vnops.c 8.2 (Berkeley) 1/21/94 39 * $Id: vfs_vnops.c,v 1.11 1994/06/08 11:29:00 mycroft Exp $ 40 */ 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/kernel.h> 45 #include <sys/file.h> 46 #include <sys/stat.h> 47 #include <sys/buf.h> 48 #include <sys/proc.h> 49 #include <sys/mount.h> 50 #include <sys/namei.h> 51 #include <sys/vnode.h> 52 #include <sys/ioctl.h> 53 #include <sys/tty.h> 54 55 #include <vm/vm.h> 56 57 struct fileops vnops = 58 { vn_read, vn_write, vn_ioctl, vn_select, vn_closefile }; 59 60 /* 61 * Common code for vnode open operations. 62 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine. 63 */ 64 vn_open(ndp, fmode, cmode) 65 register struct nameidata *ndp; 66 int fmode, cmode; 67 { 68 register struct vnode *vp; 69 register struct proc *p = ndp->ni_cnd.cn_proc; 70 register struct ucred *cred = p->p_ucred; 71 struct vattr vat; 72 struct vattr *vap = &vat; 73 int error; 74 75 if (fmode & O_CREAT) { 76 ndp->ni_cnd.cn_nameiop = CREATE; 77 ndp->ni_cnd.cn_flags = LOCKPARENT | LOCKLEAF; 78 if ((fmode & O_EXCL) == 0) 79 ndp->ni_cnd.cn_flags |= FOLLOW; 80 if (error = namei(ndp)) 81 return (error); 82 if (ndp->ni_vp == NULL) { 83 VATTR_NULL(vap); 84 vap->va_type = VREG; 85 vap->va_mode = cmode; 86 LEASE_CHECK(ndp->ni_dvp, p, cred, LEASE_WRITE); 87 if (error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp, 88 &ndp->ni_cnd, vap)) 89 return (error); 90 fmode &= ~O_TRUNC; 91 vp = ndp->ni_vp; 92 } else { 93 VOP_ABORTOP(ndp->ni_dvp, &ndp->ni_cnd); 94 if (ndp->ni_dvp == ndp->ni_vp) 95 vrele(ndp->ni_dvp); 96 else 97 vput(ndp->ni_dvp); 98 ndp->ni_dvp = NULL; 99 vp = ndp->ni_vp; 100 if (fmode & O_EXCL) { 101 error = EEXIST; 102 goto bad; 103 } 104 fmode &= ~O_CREAT; 105 } 106 } else { 107 ndp->ni_cnd.cn_nameiop = LOOKUP; 108 ndp->ni_cnd.cn_flags = FOLLOW | LOCKLEAF; 109 if (error = namei(ndp)) 110 return (error); 111 vp = ndp->ni_vp; 112 } 113 if (vp->v_type == VSOCK) { 114 error = EOPNOTSUPP; 115 goto bad; 116 } 117 if ((fmode & O_CREAT) == 0) { 118 if (fmode & FREAD) { 119 if (error = VOP_ACCESS(vp, VREAD, cred, p)) 120 goto bad; 121 } 122 if (fmode & (FWRITE | O_TRUNC)) { 123 if (vp->v_type == VDIR) { 124 error = EISDIR; 125 goto bad; 126 } 127 if ((error = vn_writechk(vp)) || 128 (error = VOP_ACCESS(vp, VWRITE, cred, p))) 129 goto bad; 130 } 131 } 132 if (fmode & O_TRUNC) { 133 VOP_UNLOCK(vp); /* XXX */ 134 LEASE_CHECK(vp, p, cred, LEASE_WRITE); 135 VOP_LOCK(vp); /* XXX */ 136 VATTR_NULL(vap); 137 vap->va_size = 0; 138 if (error = VOP_SETATTR(vp, vap, cred, p)) 139 goto bad; 140 } 141 if (error = VOP_OPEN(vp, fmode, cred, p)) 142 goto bad; 143 if (fmode & FWRITE) 144 vp->v_writecount++; 145 return (0); 146 bad: 147 vput(vp); 148 return (error); 149 } 150 151 /* 152 * Check for write permissions on the specified vnode. 153 * The read-only status of the file system is checked. 154 * Also, prototype text segments cannot be written. 155 */ 156 vn_writechk(vp) 157 register struct vnode *vp; 158 { 159 160 /* 161 * Disallow write attempts on read-only file systems; 162 * unless the file is a socket or a block or character 163 * device resident on the file system. 164 */ 165 if (vp->v_mount->mnt_flag & MNT_RDONLY) { 166 switch (vp->v_type) { 167 case VREG: case VDIR: case VLNK: 168 return (EROFS); 169 } 170 } 171 /* 172 * If there's shared text associated with 173 * the vnode, try to free it up once. If 174 * we fail, we can't allow writing. 175 */ 176 if ((vp->v_flag & VTEXT) && !vnode_pager_uncache(vp)) 177 return (ETXTBSY); 178 return (0); 179 } 180 181 /* 182 * Vnode close call 183 */ 184 vn_close(vp, flags, cred, p) 185 register struct vnode *vp; 186 int flags; 187 struct ucred *cred; 188 struct proc *p; 189 { 190 int error; 191 192 if (flags & FWRITE) 193 vp->v_writecount--; 194 error = VOP_CLOSE(vp, flags, cred, p); 195 vrele(vp); 196 return (error); 197 } 198 199 /* 200 * Package up an I/O request on a vnode into a uio and do it. 201 */ 202 vn_rdwr(rw, vp, base, len, offset, segflg, ioflg, cred, aresid, p) 203 enum uio_rw rw; 204 struct vnode *vp; 205 caddr_t base; 206 int len; 207 off_t offset; 208 enum uio_seg segflg; 209 int ioflg; 210 struct ucred *cred; 211 int *aresid; 212 struct proc *p; 213 { 214 struct uio auio; 215 struct iovec aiov; 216 int error; 217 218 if ((ioflg & IO_NODELOCKED) == 0) 219 VOP_LOCK(vp); 220 auio.uio_iov = &aiov; 221 auio.uio_iovcnt = 1; 222 aiov.iov_base = base; 223 aiov.iov_len = len; 224 auio.uio_resid = len; 225 auio.uio_offset = offset; 226 auio.uio_segflg = segflg; 227 auio.uio_rw = rw; 228 auio.uio_procp = p; 229 if (rw == UIO_READ) { 230 error = VOP_READ(vp, &auio, ioflg, cred); 231 } else { 232 error = VOP_WRITE(vp, &auio, ioflg, cred); 233 } 234 if (aresid) 235 *aresid = auio.uio_resid; 236 else 237 if (auio.uio_resid && error == 0) 238 error = EIO; 239 if ((ioflg & IO_NODELOCKED) == 0) 240 VOP_UNLOCK(vp); 241 return (error); 242 } 243 244 /* 245 * File table vnode read routine. 246 */ 247 vn_read(fp, uio, cred) 248 struct file *fp; 249 struct uio *uio; 250 struct ucred *cred; 251 { 252 register struct vnode *vp = (struct vnode *)fp->f_data; 253 int count, error; 254 255 LEASE_CHECK(vp, uio->uio_procp, cred, LEASE_READ); 256 VOP_LOCK(vp); 257 uio->uio_offset = fp->f_offset; 258 count = uio->uio_resid; 259 error = VOP_READ(vp, uio, (fp->f_flag & FNONBLOCK) ? IO_NDELAY : 0, 260 cred); 261 fp->f_offset += count - uio->uio_resid; 262 VOP_UNLOCK(vp); 263 return (error); 264 } 265 266 /* 267 * File table vnode write routine. 268 */ 269 vn_write(fp, uio, cred) 270 struct file *fp; 271 struct uio *uio; 272 struct ucred *cred; 273 { 274 register struct vnode *vp = (struct vnode *)fp->f_data; 275 int count, error, ioflag = 0; 276 277 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 278 ioflag |= IO_APPEND; 279 if (fp->f_flag & FNONBLOCK) 280 ioflag |= IO_NDELAY; 281 LEASE_CHECK(vp, uio->uio_procp, cred, LEASE_WRITE); 282 VOP_LOCK(vp); 283 uio->uio_offset = fp->f_offset; 284 count = uio->uio_resid; 285 error = VOP_WRITE(vp, uio, ioflag, cred); 286 if (ioflag & IO_APPEND) 287 fp->f_offset = uio->uio_offset; 288 else 289 fp->f_offset += count - uio->uio_resid; 290 VOP_UNLOCK(vp); 291 return (error); 292 } 293 294 /* 295 * File table vnode stat routine. 296 */ 297 vn_stat(vp, sb, p) 298 struct vnode *vp; 299 register struct stat *sb; 300 struct proc *p; 301 { 302 struct vattr vattr; 303 register struct vattr *vap; 304 int error; 305 u_short mode; 306 307 vap = &vattr; 308 error = VOP_GETATTR(vp, vap, p->p_ucred, p); 309 if (error) 310 return (error); 311 /* 312 * Copy from vattr table 313 */ 314 sb->st_dev = vap->va_fsid; 315 sb->st_ino = vap->va_fileid; 316 mode = vap->va_mode; 317 switch (vp->v_type) { 318 case VREG: 319 mode |= S_IFREG; 320 break; 321 case VDIR: 322 mode |= S_IFDIR; 323 break; 324 case VBLK: 325 mode |= S_IFBLK; 326 break; 327 case VCHR: 328 mode |= S_IFCHR; 329 break; 330 case VLNK: 331 mode |= S_IFLNK; 332 break; 333 case VSOCK: 334 mode |= S_IFSOCK; 335 break; 336 case VFIFO: 337 mode |= S_IFIFO; 338 break; 339 default: 340 return (EBADF); 341 }; 342 sb->st_mode = mode; 343 sb->st_nlink = vap->va_nlink; 344 sb->st_uid = vap->va_uid; 345 sb->st_gid = vap->va_gid; 346 sb->st_rdev = vap->va_rdev; 347 sb->st_size = vap->va_size; 348 sb->st_atimespec = vap->va_atime; 349 sb->st_mtimespec = vap->va_mtime; 350 sb->st_ctimespec = vap->va_ctime; 351 sb->st_blksize = vap->va_blocksize; 352 sb->st_flags = vap->va_flags; 353 sb->st_gen = vap->va_gen; 354 sb->st_blocks = vap->va_bytes / S_BLKSIZE; 355 return (0); 356 } 357 358 /* 359 * File table vnode ioctl routine. 360 */ 361 vn_ioctl(fp, com, data, p) 362 struct file *fp; 363 int com; 364 caddr_t data; 365 struct proc *p; 366 { 367 register struct vnode *vp = ((struct vnode *)fp->f_data); 368 struct vattr vattr; 369 int error; 370 371 switch (vp->v_type) { 372 373 case VREG: 374 case VDIR: 375 if (com == FIONREAD) { 376 if (error = VOP_GETATTR(vp, &vattr, p->p_ucred, p)) 377 return (error); 378 *(int *)data = vattr.va_size - fp->f_offset; 379 return (0); 380 } 381 if (com == FIONBIO || com == FIOASYNC) /* XXX */ 382 return (0); /* XXX */ 383 /* fall into ... */ 384 385 default: 386 return (ENOTTY); 387 388 case VFIFO: 389 case VCHR: 390 case VBLK: 391 error = VOP_IOCTL(vp, com, data, fp->f_flag, p->p_ucred, p); 392 if (error == 0 && com == TIOCSCTTY) { 393 p->p_session->s_ttyvp = vp; 394 VREF(vp); 395 } 396 return (error); 397 } 398 } 399 400 /* 401 * File table vnode select routine. 402 */ 403 vn_select(fp, which, p) 404 struct file *fp; 405 int which; 406 struct proc *p; 407 { 408 409 return (VOP_SELECT(((struct vnode *)fp->f_data), which, fp->f_flag, 410 fp->f_cred, p)); 411 } 412 413 /* 414 * File table vnode close routine. 415 */ 416 vn_closefile(fp, p) 417 struct file *fp; 418 struct proc *p; 419 { 420 421 return (vn_close(((struct vnode *)fp->f_data), fp->f_flag, 422 fp->f_cred, p)); 423 } 424
Indexes created Sun Sep 21 20:09:37 GMT 2025