| 1 | /* |
| 2 | * Copyright (c) 1982, 1986, 1989 Regents of the University of California. |
| 3 | * All rights reserved. |
| 4 | * |
| 5 | * Redistribution and use in source and binary forms, with or without |
| 6 | * modification, are permitted provided that the following conditions |
| 7 | * are met: |
| 8 | * 1. Redistributions of source code must retain the above copyright |
| 9 | * notice, this list of conditions and the following disclaimer. |
| 10 | * 2. Redistributions in binary form must reproduce the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer in the |
| 12 | * documentation and/or other materials provided with the distribution. |
| 13 | * 3. All advertising materials mentioning features or use of this software |
| 14 | * must display the following acknowledgement: |
| 15 | * This product includes software developed by the University of |
| 16 | * California, Berkeley and its contributors. |
| 17 | * 4. Neither the name of the University nor the names of its contributors |
| 18 | * may be used to endorse or promote products derived from this software |
| 19 | * without specific prior written permission. |
| 20 | * |
| 21 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 22 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 23 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 24 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 25 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 26 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 27 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 28 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 29 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 30 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 31 | * SUCH DAMAGE. |
| 32 | * |
| 33 | * @(#)vfs_vnops.c 7.33 (Berkeley) 6/27/91 |
| 34 | */ |
| 35 | |
| 36 | #include "param.h" |
| 37 | #include "systm.h" |
| 38 | #include "kernel.h" |
| 39 | #include "file.h" |
| 40 | #include "stat.h" |
| 41 | #include "buf.h" |
| 42 | #include "proc.h" |
| 43 | #include "mount.h" |
| 44 | #include "namei.h" |
| 45 | #include "vnode.h" |
| 46 | #include "ioctl.h" |
| 47 | #include "tty.h" |
| 48 | |
| 49 | struct fileops vnops = |
| 50 | { vn_read, vn_write, vn_ioctl, vn_select, vn_closefile }; |
| 51 | |
| 52 | /* |
| 53 | * Common code for vnode open operations. |
| 54 | * Check permissions, and call the VOP_OPEN or VOP_CREATE routine. |
| 55 | */ |
| 56 | vn_open(ndp, p, fmode, cmode) |
| 57 | register struct nameidata *ndp; |
| 58 | struct proc *p; |
| 59 | int fmode, cmode; |
| 60 | { |
| 61 | register struct vnode *vp; |
| 62 | register struct ucred *cred = p->p_ucred; |
| 63 | struct vattr vat; |
| 64 | struct vattr *vap = &vat; |
| 65 | int error; |
| 66 | |
| 67 | if (fmode & O_CREAT) { |
| 68 | ndp->ni_nameiop = CREATE | LOCKPARENT | LOCKLEAF; |
| 69 | if ((fmode & O_EXCL) == 0) |
| 70 | ndp->ni_nameiop |= FOLLOW; |
| 71 | if (error = namei(ndp, p)) |
| 72 | return (error); |
| 73 | if (ndp->ni_vp == NULL) { |
| 74 | VATTR_NULL(vap); |
| 75 | vap->va_type = VREG; |
| 76 | vap->va_mode = cmode; |
| 77 | if (error = VOP_CREATE(ndp, vap, p)) |
| 78 | return (error); |
| 79 | fmode &= ~O_TRUNC; |
| 80 | vp = ndp->ni_vp; |
| 81 | } else { |
| 82 | VOP_ABORTOP(ndp); |
| 83 | if (ndp->ni_dvp == ndp->ni_vp) |
| 84 | vrele(ndp->ni_dvp); |
| 85 | else |
| 86 | vput(ndp->ni_dvp); |
| 87 | ndp->ni_dvp = NULL; |
| 88 | vp = ndp->ni_vp; |
| 89 | if (fmode & O_EXCL) { |
| 90 | error = EEXIST; |
| 91 | goto bad; |
| 92 | } |
| 93 | fmode &= ~O_CREAT; |
| 94 | } |
| 95 | } else { |
| 96 | ndp->ni_nameiop = LOOKUP | FOLLOW | LOCKLEAF; |
| 97 | if (error = namei(ndp, p)) |
| 98 | return (error); |
| 99 | vp = ndp->ni_vp; |
| 100 | } |
| 101 | if (vp->v_type == VSOCK) { |
| 102 | error = EOPNOTSUPP; |
| 103 | goto bad; |
| 104 | } |
| 105 | if ((fmode & O_CREAT) == 0) { |
| 106 | if (fmode & FREAD) { |
| 107 | if (error = VOP_ACCESS(vp, VREAD, cred, p)) |
| 108 | goto bad; |
| 109 | } |
| 110 | if (fmode & (FWRITE | O_TRUNC)) { |
| 111 | if (vp->v_type == VDIR) { |
| 112 | error = EISDIR; |
| 113 | goto bad; |
| 114 | } |
| 115 | if ((error = vn_writechk(vp)) || |
| 116 | (error = VOP_ACCESS(vp, VWRITE, cred, p))) |
| 117 | goto bad; |
| 118 | } |
| 119 | } |
| 120 | if (fmode & O_TRUNC) { |
| 121 | VATTR_NULL(vap); |
| 122 | vap->va_size = 0; |
| 123 | if (error = VOP_SETATTR(vp, vap, cred, p)) |
| 124 | goto bad; |
| 125 | } |
| 126 | if (error = VOP_OPEN(vp, fmode, cred, p)) |
| 127 | goto bad; |
| 128 | if (fmode & FWRITE) |
| 129 | vp->v_writecount++; |
| 130 | return (0); |
| 131 | bad: |
| 132 | vput(vp); |
| 133 | return (error); |
| 134 | } |
| 135 | |
| 136 | /* |
| 137 | * Check for write permissions on the specified vnode. |
| 138 | * The read-only status of the file system is checked. |
| 139 | * Also, prototype text segments cannot be written. |
| 140 | */ |
| 141 | vn_writechk(vp) |
| 142 | register struct vnode *vp; |
| 143 | { |
| 144 | |
| 145 | /* |
| 146 | * Disallow write attempts on read-only file systems; |
| 147 | * unless the file is a socket or a block or character |
| 148 | * device resident on the file system. |
| 149 | */ |
| 150 | if (vp->v_mount->mnt_flag & MNT_RDONLY) { |
| 151 | switch (vp->v_type) { |
| 152 | case VREG: case VDIR: case VLNK: |
| 153 | return (EROFS); |
| 154 | } |
| 155 | } |
| 156 | /* |
| 157 | * If there's shared text associated with |
| 158 | * the vnode, try to free it up once. If |
| 159 | * we fail, we can't allow writing. |
| 160 | */ |
| 161 | if ((vp->v_flag & VTEXT) && !vnode_pager_uncache(vp)) |
| 162 | return (ETXTBSY); |
| 163 | return (0); |
| 164 | } |
| 165 | |
| 166 | /* |
| 167 | * Vnode close call |
| 168 | */ |
| 169 | vn_close(vp, flags, cred, p) |
| 170 | register struct vnode *vp; |
| 171 | int flags; |
| 172 | struct ucred *cred; |
| 173 | struct proc *p; |
| 174 | { |
| 175 | int error; |
| 176 | |
| 177 | if (flags & FWRITE) |
| 178 | vp->v_writecount--; |
| 179 | error = VOP_CLOSE(vp, flags, cred, p); |
| 180 | vrele(vp); |
| 181 | return (error); |
| 182 | } |
| 183 | |
| 184 | /* |
| 185 | * Package up an I/O request on a vnode into a uio and do it. |
| 186 | * [internal interface to file i/o for kernel only] |
| 187 | */ |
| 188 | vn_rdwr(rw, vp, base, len, offset, segflg, ioflg, cred, aresid, p) |
| 189 | enum uio_rw rw; |
| 190 | struct vnode *vp; |
| 191 | caddr_t base; |
| 192 | int len; |
| 193 | off_t offset; |
| 194 | enum uio_seg segflg; |
| 195 | int ioflg; |
| 196 | struct ucred *cred; |
| 197 | int *aresid; |
| 198 | struct proc *p; |
| 199 | { |
| 200 | struct uio auio; |
| 201 | struct iovec aiov; |
| 202 | int error; |
| 203 | |
| 204 | if ((ioflg & IO_NODELOCKED) == 0) |
| 205 | VOP_LOCK(vp); |
| 206 | auio.uio_iov = &aiov; |
| 207 | auio.uio_iovcnt = 1; |
| 208 | aiov.iov_base = base; |
| 209 | aiov.iov_len = len; |
| 210 | auio.uio_resid = len; |
| 211 | auio.uio_offset = offset; |
| 212 | auio.uio_segflg = segflg; |
| 213 | auio.uio_rw = rw; |
| 214 | auio.uio_procp = p; |
| 215 | if (rw == UIO_READ) |
| 216 | error = VOP_READ(vp, &auio, ioflg, cred); |
| 217 | else |
| 218 | error = VOP_WRITE(vp, &auio, ioflg, cred); |
| 219 | if (aresid) |
| 220 | *aresid = auio.uio_resid; |
| 221 | else |
| 222 | if (auio.uio_resid && error == 0) |
| 223 | error = EIO; |
| 224 | if ((ioflg & IO_NODELOCKED) == 0) |
| 225 | VOP_UNLOCK(vp); |
| 226 | return (error); |
| 227 | } |
| 228 | |
| 229 | /* |
| 230 | * File table vnode read routine. |
| 231 | */ |
| 232 | vn_read(fp, uio, cred) |
| 233 | struct file *fp; |
| 234 | struct uio *uio; |
| 235 | struct ucred *cred; |
| 236 | { |
| 237 | register struct vnode *vp = (struct vnode *)fp->f_data; |
| 238 | int count, error; |
| 239 | |
| 240 | VOP_LOCK(vp); |
| 241 | uio->uio_offset = fp->f_offset; |
| 242 | count = uio->uio_resid; |
| 243 | error = VOP_READ(vp, uio, (fp->f_flag & FNONBLOCK) ? IO_NDELAY : 0, |
| 244 | cred); |
| 245 | fp->f_offset += count - uio->uio_resid; |
| 246 | VOP_UNLOCK(vp); |
| 247 | return (error); |
| 248 | } |
| 249 | |
| 250 | /* |
| 251 | * File table vnode write routine. |
| 252 | */ |
| 253 | vn_write(fp, uio, cred) |
| 254 | struct file *fp; |
| 255 | struct uio *uio; |
| 256 | struct ucred *cred; |
| 257 | { |
| 258 | register struct vnode *vp = (struct vnode *)fp->f_data; |
| 259 | int count, error, ioflag = 0; |
| 260 | |
| 261 | if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) |
| 262 | ioflag |= IO_APPEND; |
| 263 | if (fp->f_flag & FNONBLOCK) |
| 264 | ioflag |= IO_NDELAY; |
| 265 | VOP_LOCK(vp); |
| 266 | uio->uio_offset = fp->f_offset; |
| 267 | count = uio->uio_resid; |
| 268 | error = VOP_WRITE(vp, uio, ioflag, cred); |
| 269 | if (ioflag & IO_APPEND) |
| 270 | fp->f_offset = uio->uio_offset; |
| 271 | else |
| 272 | fp->f_offset += count - uio->uio_resid; |
| 273 | VOP_UNLOCK(vp); |
| 274 | return (error); |
| 275 | } |
| 276 | |
| 277 | /* |
| 278 | * File table vnode stat routine. |
| 279 | */ |
| 280 | vn_stat(vp, sb, p) |
| 281 | struct vnode *vp; |
| 282 | register struct stat *sb; |
| 283 | struct proc *p; |
| 284 | { |
| 285 | struct vattr vattr; |
| 286 | register struct vattr *vap; |
| 287 | int error; |
| 288 | u_short mode; |
| 289 | |
| 290 | vap = &vattr; |
| 291 | error = VOP_GETATTR(vp, vap, p->p_ucred, p); |
| 292 | if (error) |
| 293 | return (error); |
| 294 | /* |
| 295 | * Copy from vattr table |
| 296 | */ |
| 297 | sb->st_dev = vap->va_fsid; |
| 298 | sb->st_ino = vap->va_fileid; |
| 299 | mode = vap->va_mode; |
| 300 | switch (vp->v_type) { |
| 301 | case VREG: |
| 302 | mode |= S_IFREG; |
| 303 | break; |
| 304 | case VDIR: |
| 305 | mode |= S_IFDIR; |
| 306 | break; |
| 307 | case VBLK: |
| 308 | mode |= S_IFBLK; |
| 309 | break; |
| 310 | case VCHR: |
| 311 | mode |= S_IFCHR; |
| 312 | break; |
| 313 | case VLNK: |
| 314 | mode |= S_IFLNK; |
| 315 | break; |
| 316 | case VSOCK: |
| 317 | mode |= S_IFSOCK; |
| 318 | break; |
| 319 | case VFIFO: |
| 320 | mode |= S_IFIFO; |
| 321 | break; |
| 322 | default: |
| 323 | return (EBADF); |
| 324 | }; |
| 325 | sb->st_mode = mode; |
| 326 | sb->st_nlink = vap->va_nlink; |
| 327 | sb->st_uid = vap->va_uid; |
| 328 | sb->st_gid = vap->va_gid; |
| 329 | sb->st_rdev = vap->va_rdev; |
| 330 | sb->st_size = vap->va_size; |
| 331 | sb->st_atime = vap->va_atime.tv_sec; |
| 332 | sb->st_spare1 = 0; |
| 333 | sb->st_mtime = vap->va_mtime.tv_sec; |
| 334 | sb->st_spare2 = 0; |
| 335 | sb->st_ctime = vap->va_ctime.tv_sec; |
| 336 | sb->st_spare3 = 0; |
| 337 | sb->st_blksize = vap->va_blocksize; |
| 338 | sb->st_flags = vap->va_flags; |
| 339 | sb->st_gen = vap->va_gen; |
| 340 | sb->st_blocks = vap->va_bytes / S_BLKSIZE; |
| 341 | return (0); |
| 342 | } |
| 343 | |
| 344 | /* |
| 345 | * File table vnode ioctl routine. |
| 346 | */ |
| 347 | vn_ioctl(fp, com, data, p) |
| 348 | struct file *fp; |
| 349 | int com; |
| 350 | caddr_t data; |
| 351 | struct proc *p; |
| 352 | { |
| 353 | register struct vnode *vp = ((struct vnode *)fp->f_data); |
| 354 | struct vattr vattr; |
| 355 | int error; |
| 356 | |
| 357 | switch (vp->v_type) { |
| 358 | |
| 359 | case VREG: |
| 360 | case VDIR: |
| 361 | if (com == FIONREAD) { |
| 362 | if (error = VOP_GETATTR(vp, &vattr, p->p_ucred, p)) |
| 363 | return (error); |
| 364 | *(off_t *)data = vattr.va_size - fp->f_offset; |
| 365 | return (0); |
| 366 | } |
| 367 | if (com == FIONBIO || com == FIOASYNC) /* XXX */ |
| 368 | return (0); /* XXX */ |
| 369 | /* fall into ... */ |
| 370 | |
| 371 | default: |
| 372 | return (ENOTTY); |
| 373 | |
| 374 | case VFIFO: |
| 375 | case VCHR: |
| 376 | case VBLK: |
| 377 | error = VOP_IOCTL(vp, com, data, fp->f_flag, p->p_ucred, p); |
| 378 | if (error == 0 && com == TIOCSCTTY) { |
| 379 | p->p_session->s_ttyvp = vp; |
| 380 | VREF(vp); |
| 381 | } |
| 382 | return (error); |
| 383 | } |
| 384 | } |
| 385 | |
| 386 | /* |
| 387 | * File table vnode select routine. |
| 388 | */ |
| 389 | vn_select(fp, which, p) |
| 390 | struct file *fp; |
| 391 | int which; |
| 392 | struct proc *p; |
| 393 | { |
| 394 | |
| 395 | return (VOP_SELECT(((struct vnode *)fp->f_data), which, fp->f_flag, |
| 396 | fp->f_cred, p)); |
| 397 | } |
| 398 | |
| 399 | /* |
| 400 | * File table vnode close routine. |
| 401 | */ |
| 402 | vn_closefile(fp, p) |
| 403 | struct file *fp; |
| 404 | struct proc *p; |
| 405 | { |
| 406 | |
| 407 | return (vn_close(((struct vnode *)fp->f_data), fp->f_flag, |
| 408 | fp->f_cred, p)); |
| 409 | } |
| 410 | |
| 411 | /* |
| 412 | * vn_fhtovp() - convert a fh to a vnode ptr (optionally locked) |
| 413 | * - look up fsid in mount list (if not found ret error) |
| 414 | * - get vp by calling VFS_FHTOVP() macro |
| 415 | * - if lockflag lock it with VOP_LOCK() |
| 416 | */ |
| 417 | vn_fhtovp(fhp, lockflag, vpp) |
| 418 | fhandle_t *fhp; |
| 419 | int lockflag; |
| 420 | struct vnode **vpp; |
| 421 | { |
| 422 | register struct mount *mp; |
| 423 | |
| 424 | if ((mp = getvfs(&fhp->fh_fsid)) == NULL) |
| 425 | return (ESTALE); |
| 426 | if (VFS_FHTOVP(mp, &fhp->fh_fid, vpp)) |
| 427 | return (ESTALE); |
| 428 | if (!lockflag) |
| 429 | VOP_UNLOCK(*vpp); |
| 430 | return (0); |
| 431 | } |