| 1 | /* vfs_syscalls.c 4.51 83/02/20 */ |
| 2 | |
| 3 | #include "../h/param.h" |
| 4 | #include "../h/systm.h" |
| 5 | #include "../h/dir.h" |
| 6 | #include "../h/user.h" |
| 7 | #include "../h/kernel.h" |
| 8 | #include "../h/file.h" |
| 9 | #include "../h/stat.h" |
| 10 | #include "../h/inode.h" |
| 11 | #include "../h/fs.h" |
| 12 | #include "../h/buf.h" |
| 13 | #include "../h/proc.h" |
| 14 | #include "../h/quota.h" |
| 15 | #include "../h/descrip.h" |
| 16 | #include "../h/uio.h" |
| 17 | #include "../h/socket.h" |
| 18 | #include "../h/socketvar.h" |
| 19 | #include "../h/nami.h" |
| 20 | |
| 21 | /* |
| 22 | * Change current working directory (``.''). |
| 23 | */ |
| 24 | chdir() |
| 25 | { |
| 26 | |
| 27 | chdirec(&u.u_cdir); |
| 28 | } |
| 29 | |
| 30 | /* |
| 31 | * Change notion of root (``/'') directory. |
| 32 | */ |
| 33 | chroot() |
| 34 | { |
| 35 | |
| 36 | if (suser()) |
| 37 | chdirec(&u.u_rdir); |
| 38 | } |
| 39 | |
| 40 | /* |
| 41 | * Common routine for chroot and chdir. |
| 42 | */ |
| 43 | chdirec(ipp) |
| 44 | register struct inode **ipp; |
| 45 | { |
| 46 | register struct inode *ip; |
| 47 | struct a { |
| 48 | char *fname; |
| 49 | }; |
| 50 | |
| 51 | ip = namei(uchar, LOOKUP, 1); |
| 52 | if (ip == NULL) |
| 53 | return; |
| 54 | if ((ip->i_mode&IFMT) != IFDIR) { |
| 55 | u.u_error = ENOTDIR; |
| 56 | goto bad; |
| 57 | } |
| 58 | if (access(ip, IEXEC)) |
| 59 | goto bad; |
| 60 | iunlock(ip); |
| 61 | if (*ipp) |
| 62 | irele(*ipp); |
| 63 | *ipp = ip; |
| 64 | return; |
| 65 | |
| 66 | bad: |
| 67 | iput(ip); |
| 68 | } |
| 69 | |
| 70 | /* |
| 71 | * Open system call. |
| 72 | */ |
| 73 | open() |
| 74 | { |
| 75 | register struct inode *ip; |
| 76 | register struct a { |
| 77 | char *fname; |
| 78 | int flags; |
| 79 | int mode; |
| 80 | } *uap; |
| 81 | int checkpermissions = 1, flags; |
| 82 | |
| 83 | uap = (struct a *)u.u_ap; |
| 84 | flags = uap->flags + 1; |
| 85 | if ((flags&FTRUNCATE) && (flags&FWRITE) == 0) { |
| 86 | u.u_error = EINVAL; |
| 87 | return; |
| 88 | } |
| 89 | if (flags&FCREATE) { |
| 90 | ip = namei(uchar, CREATE, 1); |
| 91 | if (ip == NULL) { |
| 92 | if (u.u_error) |
| 93 | return; |
| 94 | ip = maknode(uap->mode&07777&(~ISVTX)); |
| 95 | checkpermissions = 0; |
| 96 | flags &= ~FTRUNCATE; |
| 97 | } |
| 98 | } else |
| 99 | ip = namei(uchar, LOOKUP, 1); |
| 100 | if (ip == NULL) |
| 101 | return; |
| 102 | open1(ip, flags, checkpermissions); |
| 103 | } |
| 104 | |
| 105 | #ifndef NOCOMPAT |
| 106 | /* |
| 107 | * Creat system call. |
| 108 | */ |
| 109 | ocreat() |
| 110 | { |
| 111 | register struct inode *ip; |
| 112 | register struct a { |
| 113 | char *fname; |
| 114 | int fmode; |
| 115 | } *uap; |
| 116 | |
| 117 | uap = (struct a *)u.u_ap; |
| 118 | ip = namei(uchar, CREATE, 1); |
| 119 | if (ip == NULL) { |
| 120 | if (u.u_error) |
| 121 | return; |
| 122 | ip = maknode(uap->fmode&07777&(~ISVTX)); |
| 123 | if (ip == NULL) |
| 124 | return; |
| 125 | open1(ip, FWRITE, 0); |
| 126 | } else |
| 127 | open1(ip, FWRITE|FTRUNCATE, 1); |
| 128 | } |
| 129 | #endif |
| 130 | |
| 131 | /* |
| 132 | * Common code for open and creat. |
| 133 | * Check permissions (if we haven't done so already), |
| 134 | * allocate an open file structure, and call |
| 135 | * the device open routine, if any. |
| 136 | */ |
| 137 | open1(ip, mode, checkpermissions) |
| 138 | register struct inode *ip; |
| 139 | register mode; |
| 140 | { |
| 141 | register struct file *fp; |
| 142 | int i, flags; |
| 143 | |
| 144 | if (checkpermissions) { |
| 145 | if (mode&FREAD) |
| 146 | if (access(ip, IREAD)) |
| 147 | goto bad; |
| 148 | if (mode&FWRITE) { |
| 149 | if (access(ip, IWRITE)) |
| 150 | goto bad; |
| 151 | if ((ip->i_mode&IFMT) == IFDIR) { |
| 152 | u.u_error = EISDIR; |
| 153 | goto bad; |
| 154 | } |
| 155 | } |
| 156 | } |
| 157 | |
| 158 | /* |
| 159 | * Check locking on inode. Release "inode lock" |
| 160 | * while doing so in case we block inside flocki. |
| 161 | */ |
| 162 | flags = 0; |
| 163 | if (mode&(FSHLOCK|FEXLOCK)) { |
| 164 | iunlock(ip); |
| 165 | flags = flocki(ip, 0, mode); |
| 166 | ilock(ip); |
| 167 | if (u.u_error) |
| 168 | goto bad; |
| 169 | } |
| 170 | if (mode&FTRUNCATE) |
| 171 | itrunc(ip, (u_long)0); |
| 172 | iunlock(ip); |
| 173 | if ((fp = falloc()) == NULL) |
| 174 | goto out; |
| 175 | fp->f_flag = mode & FMODES; |
| 176 | fp->f_type = DTYPE_FILE; |
| 177 | i = u.u_r.r_val1; |
| 178 | fp->f_inode = ip; |
| 179 | u.u_error = openi(ip, mode); |
| 180 | if (u.u_error == 0) { |
| 181 | u.u_pofile[i] = flags; |
| 182 | return; |
| 183 | } |
| 184 | u.u_ofile[i] = NULL; |
| 185 | fp->f_count--; |
| 186 | out: |
| 187 | irele(ip); |
| 188 | return; |
| 189 | bad: |
| 190 | iput(ip); |
| 191 | } |
| 192 | |
| 193 | /* |
| 194 | * Mknod system call |
| 195 | */ |
| 196 | mknod() |
| 197 | { |
| 198 | register struct inode *ip; |
| 199 | register struct a { |
| 200 | char *fname; |
| 201 | int fmode; |
| 202 | int dev; |
| 203 | } *uap; |
| 204 | |
| 205 | uap = (struct a *)u.u_ap; |
| 206 | if (suser()) { |
| 207 | ip = namei(uchar, CREATE, 0); |
| 208 | if (ip != NULL) { |
| 209 | u.u_error = EEXIST; |
| 210 | goto out; |
| 211 | } |
| 212 | } |
| 213 | if (u.u_error) |
| 214 | return; |
| 215 | ip = maknode(uap->fmode); |
| 216 | if (ip == NULL) |
| 217 | return; |
| 218 | if (uap->dev) { |
| 219 | /* |
| 220 | * Want to be able to use this to make badblock |
| 221 | * inodes, so don't truncate the dev number. |
| 222 | */ |
| 223 | ip->i_rdev = uap->dev; |
| 224 | ip->i_flag |= IACC|IUPD|ICHG; |
| 225 | } |
| 226 | |
| 227 | out: |
| 228 | iput(ip); |
| 229 | } |
| 230 | |
| 231 | /* |
| 232 | * link system call |
| 233 | */ |
| 234 | link() |
| 235 | { |
| 236 | register struct inode *ip, *xp; |
| 237 | register struct a { |
| 238 | char *target; |
| 239 | char *linkname; |
| 240 | } *uap; |
| 241 | |
| 242 | uap = (struct a *)u.u_ap; |
| 243 | ip = namei(uchar, LOOKUP, 1); /* well, this routine is doomed anyhow */ |
| 244 | if (ip == NULL) |
| 245 | return; |
| 246 | if ((ip->i_mode&IFMT) == IFDIR && !suser()) { |
| 247 | iput(ip); |
| 248 | return; |
| 249 | } |
| 250 | ip->i_nlink++; |
| 251 | ip->i_flag |= ICHG; |
| 252 | iupdat(ip, &time, &time, 1); |
| 253 | iunlock(ip); |
| 254 | u.u_dirp = (caddr_t)uap->linkname; |
| 255 | xp = namei(uchar, CREATE, 0); |
| 256 | if (xp != NULL) { |
| 257 | u.u_error = EEXIST; |
| 258 | iput(xp); |
| 259 | goto out; |
| 260 | } |
| 261 | if (u.u_error) |
| 262 | goto out; |
| 263 | if (u.u_pdir->i_dev != ip->i_dev) { |
| 264 | iput(u.u_pdir); |
| 265 | u.u_error = EXDEV; |
| 266 | goto out; |
| 267 | } |
| 268 | u.u_error = direnter(ip); |
| 269 | out: |
| 270 | if (u.u_error) { |
| 271 | ip->i_nlink--; |
| 272 | ip->i_flag |= ICHG; |
| 273 | } |
| 274 | irele(ip); |
| 275 | } |
| 276 | |
| 277 | /* |
| 278 | * symlink -- make a symbolic link |
| 279 | */ |
| 280 | symlink() |
| 281 | { |
| 282 | register struct a { |
| 283 | char *target; |
| 284 | char *linkname; |
| 285 | } *uap; |
| 286 | register struct inode *ip; |
| 287 | register char *tp; |
| 288 | register c, nc; |
| 289 | |
| 290 | uap = (struct a *)u.u_ap; |
| 291 | tp = uap->target; |
| 292 | nc = 0; |
| 293 | while (c = fubyte(tp)) { |
| 294 | if (c < 0) { |
| 295 | u.u_error = EFAULT; |
| 296 | return; |
| 297 | } |
| 298 | tp++; |
| 299 | nc++; |
| 300 | } |
| 301 | u.u_dirp = uap->linkname; |
| 302 | ip = namei(uchar, CREATE, 0); |
| 303 | if (ip) { |
| 304 | iput(ip); |
| 305 | u.u_error = EEXIST; |
| 306 | return; |
| 307 | } |
| 308 | if (u.u_error) |
| 309 | return; |
| 310 | ip = maknode(IFLNK | 0777); |
| 311 | if (ip == NULL) |
| 312 | return; |
| 313 | u.u_error = rdwri(UIO_WRITE, ip, uap->target, nc, 0, 0, (int *)0); |
| 314 | /* handle u.u_error != 0 */ |
| 315 | iput(ip); |
| 316 | } |
| 317 | |
| 318 | /* |
| 319 | * Unlink system call. |
| 320 | * Hard to avoid races here, especially |
| 321 | * in unlinking directories. |
| 322 | */ |
| 323 | unlink() |
| 324 | { |
| 325 | struct a { |
| 326 | char *fname; |
| 327 | }; |
| 328 | register struct inode *ip, *dp; |
| 329 | |
| 330 | ip = namei(uchar, DELETE | LOCKPARENT, 0); |
| 331 | if (ip == NULL) |
| 332 | return; |
| 333 | dp = u.u_pdir; |
| 334 | if ((ip->i_mode&IFMT) == IFDIR && !suser()) |
| 335 | goto out; |
| 336 | /* |
| 337 | * Don't unlink a mounted file. |
| 338 | */ |
| 339 | if (ip->i_dev != dp->i_dev) { |
| 340 | u.u_error = EBUSY; |
| 341 | goto out; |
| 342 | } |
| 343 | if (ip->i_flag&ITEXT) |
| 344 | xrele(ip); /* try once to free text */ |
| 345 | if (dirremove()) { |
| 346 | ip->i_nlink--; |
| 347 | ip->i_flag |= ICHG; |
| 348 | } |
| 349 | out: |
| 350 | if (dp == ip) |
| 351 | irele(ip); |
| 352 | else |
| 353 | iput(ip); |
| 354 | iput(dp); |
| 355 | } |
| 356 | |
| 357 | /* |
| 358 | * Seek system call |
| 359 | */ |
| 360 | lseek() |
| 361 | { |
| 362 | register struct file *fp; |
| 363 | register struct a { |
| 364 | int fd; |
| 365 | off_t off; |
| 366 | int sbase; |
| 367 | } *uap; |
| 368 | |
| 369 | uap = (struct a *)u.u_ap; |
| 370 | fp = getf(uap->fd); |
| 371 | if (fp == NULL) |
| 372 | return; |
| 373 | if (fp->f_type == DTYPE_SOCKET) { |
| 374 | u.u_error = ESPIPE; |
| 375 | return; |
| 376 | } |
| 377 | if (uap->sbase == FSEEK_RELATIVE) |
| 378 | uap->off += fp->f_offset; |
| 379 | else if (uap->sbase == FSEEK_EOF) |
| 380 | uap->off += fp->f_inode->i_size; |
| 381 | fp->f_offset = uap->off; |
| 382 | u.u_r.r_off = uap->off; |
| 383 | } |
| 384 | |
| 385 | /* |
| 386 | * Access system call |
| 387 | */ |
| 388 | saccess() |
| 389 | { |
| 390 | register svuid, svgid; |
| 391 | register struct inode *ip; |
| 392 | register struct a { |
| 393 | char *fname; |
| 394 | int fmode; |
| 395 | } *uap; |
| 396 | |
| 397 | uap = (struct a *)u.u_ap; |
| 398 | svuid = u.u_uid; |
| 399 | svgid = u.u_gid; |
| 400 | u.u_uid = u.u_ruid; |
| 401 | u.u_gid = u.u_rgid; |
| 402 | ip = namei(uchar, LOOKUP, 1); |
| 403 | if (ip != NULL) { |
| 404 | if ((uap->fmode&FACCESS_READ) && access(ip, IREAD)) |
| 405 | goto done; |
| 406 | if ((uap->fmode&FACCESS_WRITE) && access(ip, IWRITE)) |
| 407 | goto done; |
| 408 | if ((uap->fmode&FACCESS_EXECUTE) && access(ip, IEXEC)) |
| 409 | goto done; |
| 410 | done: |
| 411 | iput(ip); |
| 412 | } |
| 413 | u.u_uid = svuid; |
| 414 | u.u_gid = svgid; |
| 415 | } |
| 416 | |
| 417 | /* |
| 418 | * the fstat system call. |
| 419 | */ |
| 420 | fstat() |
| 421 | { |
| 422 | register struct file *fp; |
| 423 | register struct a { |
| 424 | int fd; |
| 425 | struct stat *sb; |
| 426 | } *uap; |
| 427 | |
| 428 | uap = (struct a *)u.u_ap; |
| 429 | fp = getf(uap->fd); |
| 430 | if (fp == NULL) |
| 431 | return; |
| 432 | if (fp->f_type == DTYPE_SOCKET) |
| 433 | u.u_error = sostat(fp->f_socket, uap->sb); |
| 434 | else |
| 435 | stat1(fp->f_inode, uap->sb); |
| 436 | } |
| 437 | |
| 438 | /* |
| 439 | * Stat system call. This version follows links. |
| 440 | */ |
| 441 | stat() |
| 442 | { |
| 443 | register struct inode *ip; |
| 444 | register struct a { |
| 445 | char *fname; |
| 446 | struct stat *sb; |
| 447 | } *uap; |
| 448 | |
| 449 | uap = (struct a *)u.u_ap; |
| 450 | ip = namei(uchar, LOOKUP, 1); |
| 451 | if (ip == NULL) |
| 452 | return; |
| 453 | stat1(ip, uap->sb); |
| 454 | iput(ip); |
| 455 | } |
| 456 | |
| 457 | /* |
| 458 | * Lstat system call. This version does not follow links. |
| 459 | */ |
| 460 | lstat() |
| 461 | { |
| 462 | register struct inode *ip; |
| 463 | register struct a { |
| 464 | char *fname; |
| 465 | struct stat *sb; |
| 466 | } *uap; |
| 467 | |
| 468 | uap = (struct a *)u.u_ap; |
| 469 | ip = namei(uchar, LOOKUP, 0); |
| 470 | if (ip == NULL) |
| 471 | return; |
| 472 | stat1(ip, uap->sb); |
| 473 | iput(ip); |
| 474 | } |
| 475 | |
| 476 | /* |
| 477 | * The basic routine for fstat and stat: |
| 478 | * get the inode and pass appropriate parts back. |
| 479 | */ |
| 480 | stat1(ip, ub) |
| 481 | register struct inode *ip; |
| 482 | struct stat *ub; |
| 483 | { |
| 484 | struct stat ds; |
| 485 | |
| 486 | IUPDAT(ip, &time, &time, 0); |
| 487 | /* |
| 488 | * Copy from inode table |
| 489 | */ |
| 490 | ds.st_dev = ip->i_dev; |
| 491 | ds.st_ino = ip->i_number; |
| 492 | ds.st_mode = ip->i_mode; |
| 493 | ds.st_nlink = ip->i_nlink; |
| 494 | ds.st_uid = ip->i_uid; |
| 495 | ds.st_gid = ip->i_gid; |
| 496 | ds.st_rdev = (dev_t)ip->i_rdev; |
| 497 | ds.st_size = ip->i_size; |
| 498 | ds.st_atime = ip->i_atime; |
| 499 | ds.st_spare1 = 0; |
| 500 | ds.st_mtime = ip->i_mtime; |
| 501 | ds.st_spare2 = 0; |
| 502 | ds.st_ctime = ip->i_ctime; |
| 503 | ds.st_spare3 = 0; |
| 504 | /* this doesn't belong here */ |
| 505 | if ((ip->i_mode&IFMT) == IFBLK) |
| 506 | ds.st_blksize = BLKDEV_IOSIZE; |
| 507 | else if ((ip->i_mode&IFMT) == IFCHR) |
| 508 | ds.st_blksize = MAXBSIZE; |
| 509 | else |
| 510 | ds.st_blksize = ip->i_fs->fs_bsize; |
| 511 | ds.st_spare4[0] = ds.st_spare4[1] = ds.st_spare4[2] = 0; |
| 512 | u.u_error = copyout((caddr_t)&ds, (caddr_t)ub, sizeof(ds)); |
| 513 | } |
| 514 | |
| 515 | /* |
| 516 | * Return target name of a symbolic link |
| 517 | */ |
| 518 | readlink() |
| 519 | { |
| 520 | register struct inode *ip; |
| 521 | register struct a { |
| 522 | char *name; |
| 523 | char *buf; |
| 524 | int count; |
| 525 | } *uap = (struct a *)u.u_ap; |
| 526 | int resid; |
| 527 | |
| 528 | ip = namei(uchar, LOOKUP, 0); |
| 529 | if (ip == NULL) |
| 530 | return; |
| 531 | if ((ip->i_mode&IFMT) != IFLNK) { |
| 532 | u.u_error = ENXIO; |
| 533 | goto out; |
| 534 | } |
| 535 | u.u_error = rdwri(UIO_READ, ip, uap->buf, uap->count, 0, 0, &resid); |
| 536 | out: |
| 537 | iput(ip); |
| 538 | u.u_r.r_val1 = uap->count - resid; |
| 539 | } |
| 540 | |
| 541 | /* |
| 542 | * Change mode of a file given path name. |
| 543 | */ |
| 544 | chmod() |
| 545 | { |
| 546 | struct inode *ip; |
| 547 | struct a { |
| 548 | char *fname; |
| 549 | int fmode; |
| 550 | } *uap; |
| 551 | |
| 552 | uap = (struct a *)u.u_ap; |
| 553 | if ((ip = owner(1)) == NULL) |
| 554 | return; |
| 555 | chmod1(ip, uap->fmode); |
| 556 | iput(ip); |
| 557 | } |
| 558 | |
| 559 | /* |
| 560 | * Change mode of a file given a file descriptor. |
| 561 | */ |
| 562 | fchmod() |
| 563 | { |
| 564 | struct a { |
| 565 | int fd; |
| 566 | int fmode; |
| 567 | } *uap; |
| 568 | register struct inode *ip; |
| 569 | register struct file *fp; |
| 570 | |
| 571 | uap = (struct a *)u.u_ap; |
| 572 | fp = getf(uap->fd); |
| 573 | if (fp == NULL) |
| 574 | return; |
| 575 | if (fp->f_type == DTYPE_SOCKET) { |
| 576 | u.u_error = EINVAL; |
| 577 | return; |
| 578 | } |
| 579 | ip = fp->f_inode; |
| 580 | if (u.u_uid != ip->i_uid && !suser()) |
| 581 | return; |
| 582 | ilock(ip); |
| 583 | chmod1(ip, uap->fmode); |
| 584 | iunlock(ip); |
| 585 | } |
| 586 | |
| 587 | /* |
| 588 | * Change the mode on a file. |
| 589 | * Inode must be locked before calling. |
| 590 | */ |
| 591 | chmod1(ip, mode) |
| 592 | register struct inode *ip; |
| 593 | register int mode; |
| 594 | { |
| 595 | register int *gp; |
| 596 | |
| 597 | ip->i_mode &= ~07777; |
| 598 | if (u.u_uid) { |
| 599 | mode &= ~ISVTX; |
| 600 | if (u.u_gid == ip->i_gid) |
| 601 | goto ok; |
| 602 | for (gp = u.u_groups; gp < &u.u_groups[NGROUPS]; gp++) |
| 603 | if (*gp == ip->i_gid) |
| 604 | goto ok; |
| 605 | mode &= ~ISGID; |
| 606 | ok: |
| 607 | ; |
| 608 | #ifdef MUSH |
| 609 | if (u.u_quota->q_syflags & QF_UMASK && u.u_uid != 0 && |
| 610 | (ip->i_mode & IFMT) != IFCHR) |
| 611 | mode &= ~u.u_cmask; |
| 612 | #endif |
| 613 | } |
| 614 | ip->i_mode |= mode&07777; |
| 615 | ip->i_flag |= ICHG; |
| 616 | if (ip->i_flag&ITEXT && (ip->i_mode&ISVTX)==0) |
| 617 | xrele(ip); |
| 618 | } |
| 619 | |
| 620 | /* |
| 621 | * Set ownership given a path name. |
| 622 | */ |
| 623 | chown() |
| 624 | { |
| 625 | struct inode *ip; |
| 626 | struct a { |
| 627 | char *fname; |
| 628 | int uid; |
| 629 | int gid; |
| 630 | } *uap; |
| 631 | |
| 632 | uap = (struct a *)u.u_ap; |
| 633 | if (!suser() || (ip = owner(0)) == NULL) |
| 634 | return; |
| 635 | chown1(ip, uap->uid, uap->gid); |
| 636 | iput(ip); |
| 637 | } |
| 638 | |
| 639 | /* |
| 640 | * Set ownership given a file descriptor. |
| 641 | */ |
| 642 | fchown() |
| 643 | { |
| 644 | struct a { |
| 645 | int fd; |
| 646 | int uid; |
| 647 | int gid; |
| 648 | } *uap; |
| 649 | register struct inode *ip; |
| 650 | register struct file *fp; |
| 651 | |
| 652 | uap = (struct a *)u.u_ap; |
| 653 | fp = getf(uap->fd); |
| 654 | if (fp == NULL) |
| 655 | return; |
| 656 | if (fp->f_type == DTYPE_SOCKET) { |
| 657 | u.u_error = EINVAL; |
| 658 | return; |
| 659 | } |
| 660 | ip = fp->f_inode; |
| 661 | if (!suser()) |
| 662 | return; |
| 663 | ilock(ip); |
| 664 | chown1(ip, uap->uid, uap->gid); |
| 665 | iunlock(ip); |
| 666 | } |
| 667 | |
| 668 | /* |
| 669 | * Perform chown operation on inode ip; |
| 670 | * inode must be locked prior to call. |
| 671 | */ |
| 672 | chown1(ip, uid, gid) |
| 673 | register struct inode *ip; |
| 674 | int uid, gid; |
| 675 | { |
| 676 | #ifdef QUOTA |
| 677 | register long change; |
| 678 | |
| 679 | /* |
| 680 | * This doesn't allow for holes in files (which hopefully don't |
| 681 | * happen often in files that we chown), and is not accurate anyway |
| 682 | * (eg: it totally ignores 3 level indir blk files - but hopefully |
| 683 | * noone who can make a file that big will have a quota) |
| 684 | */ |
| 685 | if (ip->i_uid == uid) |
| 686 | change = 0; |
| 687 | else { |
| 688 | register struct fs *fs = ip->i_fs; |
| 689 | |
| 690 | if (ip->i_size > (change = NDADDR * fs->fs_bsize)) { |
| 691 | register off_t size; |
| 692 | |
| 693 | size = blkroundup(fs, ip->i_size) - change; |
| 694 | change += size; |
| 695 | change += fs->fs_bsize; |
| 696 | /* this assumes NIADDR <= 2 */ |
| 697 | if (size > NINDIR(fs) * fs->fs_bsize) |
| 698 | change += fs->fs_bsize; |
| 699 | } else |
| 700 | change = fragroundup(fs, ip->i_size); |
| 701 | change /= DEV_BSIZE; |
| 702 | } |
| 703 | (void)chkdq(ip, -change, 1); |
| 704 | (void)chkiq(ip->i_dev, ip, ip->i_uid, 1); |
| 705 | dqrele(ip->i_dquot); |
| 706 | #endif |
| 707 | /* |
| 708 | * keep uid/gid's in sane range -- no err, |
| 709 | * so chown(file, uid, -1) will do something useful |
| 710 | */ |
| 711 | if (uid >= 0 && uid <= 32767) /* should have a constant */ |
| 712 | ip->i_uid = uid; |
| 713 | if (gid >= 0 && gid <= 32767) /* same here */ |
| 714 | ip->i_gid = gid; |
| 715 | ip->i_flag |= ICHG; |
| 716 | if (u.u_ruid != 0) |
| 717 | ip->i_mode &= ~(ISUID|ISGID); |
| 718 | #ifdef QUOTA |
| 719 | ip->i_dquot = inoquota(ip); |
| 720 | (void)chkdq(ip, change, 1); |
| 721 | (void)chkiq(ip->i_dev, (struct inode *)NULL, uid, 1); |
| 722 | #endif |
| 723 | } |
| 724 | |
| 725 | /* |
| 726 | * Set IUPD and IACC times on file. |
| 727 | * Can't set ICHG. |
| 728 | */ |
| 729 | outime() |
| 730 | { |
| 731 | register struct a { |
| 732 | char *fname; |
| 733 | time_t *tptr; |
| 734 | } *uap; |
| 735 | register struct inode *ip; |
| 736 | time_t tv[2]; |
| 737 | struct timeval tv0, tv1; |
| 738 | |
| 739 | uap = (struct a *)u.u_ap; |
| 740 | if ((ip = owner(1)) == NULL) |
| 741 | return; |
| 742 | u.u_error = copyin((caddr_t)uap->tptr, (caddr_t)tv, sizeof(tv)); |
| 743 | if (u.u_error == 0) { |
| 744 | ip->i_flag |= IACC|IUPD|ICHG; |
| 745 | tv0.tv_sec = tv[0]; tv0.tv_usec = 0; |
| 746 | tv1.tv_sec = tv[1]; tv1.tv_usec = 0; |
| 747 | iupdat(ip, &tv0, &tv1, 0); |
| 748 | } |
| 749 | iput(ip); |
| 750 | } |
| 751 | |
| 752 | /* |
| 753 | * Flush any pending I/O. |
| 754 | */ |
| 755 | sync() |
| 756 | { |
| 757 | |
| 758 | update(); |
| 759 | } |
| 760 | |
| 761 | /* |
| 762 | * Apply an advisory lock on a file descriptor. |
| 763 | */ |
| 764 | flock() |
| 765 | { |
| 766 | struct a { |
| 767 | int fd; |
| 768 | int how; |
| 769 | } *uap; |
| 770 | register struct file *fp; |
| 771 | register int cmd, flags; |
| 772 | |
| 773 | uap = (struct a *)u.u_ap; |
| 774 | fp = getf(uap->fd); |
| 775 | if (fp == NULL) |
| 776 | return; |
| 777 | if (fp->f_type == DTYPE_SOCKET) { /* XXX */ |
| 778 | u.u_error = EINVAL; |
| 779 | return; |
| 780 | } |
| 781 | cmd = uap->how; |
| 782 | flags = u.u_pofile[uap->fd] & (UF_SHLOCK|UF_EXLOCK); |
| 783 | if (cmd&FUNLOCK) { |
| 784 | if (flags == 0) { |
| 785 | u.u_error = EINVAL; |
| 786 | return; |
| 787 | } |
| 788 | funlocki(fp->f_inode, flags); |
| 789 | u.u_pofile[uap->fd] &= ~(UF_SHLOCK|UF_EXLOCK); |
| 790 | return; |
| 791 | } |
| 792 | /* |
| 793 | * No reason to write lock a file we've already |
| 794 | * write locked, similarly with a read lock. |
| 795 | */ |
| 796 | if ((flags&UF_EXLOCK) && (cmd&FEXLOCK) || |
| 797 | (flags&UF_SHLOCK) && (cmd&FSHLOCK)) |
| 798 | return; |
| 799 | u.u_pofile[uap->fd] = flocki(fp->f_inode, u.u_pofile[uap->fd], cmd); |
| 800 | } |
| 801 | |
| 802 | /* |
| 803 | * Truncate a file given its path name. |
| 804 | */ |
| 805 | truncate() |
| 806 | { |
| 807 | struct a { |
| 808 | char *fname; |
| 809 | u_long length; |
| 810 | } *uap = (struct a *)u.u_ap; |
| 811 | struct inode *ip; |
| 812 | |
| 813 | ip = namei(uchar, LOOKUP, 1); |
| 814 | if (ip == NULL) |
| 815 | return; |
| 816 | if (access(ip, IWRITE)) |
| 817 | goto bad; |
| 818 | if ((ip->i_mode&IFMT) == IFDIR) { |
| 819 | u.u_error = EISDIR; |
| 820 | goto bad; |
| 821 | } |
| 822 | itrunc(ip, uap->length); |
| 823 | bad: |
| 824 | iput(ip); |
| 825 | } |
| 826 | |
| 827 | /* |
| 828 | * Truncate a file given a file descriptor. |
| 829 | */ |
| 830 | ftruncate() |
| 831 | { |
| 832 | struct a { |
| 833 | int fd; |
| 834 | u_long length; |
| 835 | } *uap = (struct a *)u.u_ap; |
| 836 | struct inode *ip; |
| 837 | struct file *fp; |
| 838 | |
| 839 | fp = getf(uap->fd); |
| 840 | if (fp == NULL) |
| 841 | return; |
| 842 | if (fp->f_type == DTYPE_SOCKET) { |
| 843 | u.u_error = EINVAL; |
| 844 | return; |
| 845 | } |
| 846 | if ((fp->f_flag&FWRITE) == 0) { |
| 847 | u.u_error = EINVAL; |
| 848 | return; |
| 849 | } |
| 850 | ip = fp->f_inode; |
| 851 | ilock(ip); |
| 852 | itrunc(ip, uap->length); |
| 853 | iunlock(ip); |
| 854 | } |
| 855 | |
| 856 | /* |
| 857 | * Synch an open file. |
| 858 | */ |
| 859 | fsync() |
| 860 | { |
| 861 | struct a { |
| 862 | int fd; |
| 863 | } *uap = (struct a *)u.u_ap; |
| 864 | struct inode *ip; |
| 865 | struct file *fp; |
| 866 | |
| 867 | fp = getf(uap->fd); |
| 868 | if (fp == NULL) |
| 869 | return; |
| 870 | if (fp->f_type == DTYPE_SOCKET) { |
| 871 | u.u_error = EINVAL; |
| 872 | return; |
| 873 | } |
| 874 | ip = fp->f_inode; |
| 875 | ilock(ip); |
| 876 | syncip(ip); |
| 877 | iunlock(ip); |
| 878 | } |
| 879 | |
| 880 | /* |
| 881 | * Rename system call. |
| 882 | * rename("foo", "bar"); |
| 883 | * is essentially |
| 884 | * unlink("bar"); |
| 885 | * link("foo", "bar"); |
| 886 | * unlink("foo"); |
| 887 | * but ``atomically''. Can't do full commit without saving state in the |
| 888 | * inode on disk which isn't feasible at this time. Best we can do is |
| 889 | * always guarantee the target exists. |
| 890 | * |
| 891 | * Basic algorithm is: |
| 892 | * |
| 893 | * 1) Bump link count on source while we're linking it to the |
| 894 | * target. This also insure the inode won't be deleted out |
| 895 | * from underneath us while we work. |
| 896 | * 2) Link source to destination. If destination already exists, |
| 897 | * delete it first. |
| 898 | * 3) Unlink source reference to inode if still around. |
| 899 | * 4) If a directory was moved and the parent of the destination |
| 900 | * is different from the source, patch the ".." entry in the |
| 901 | * directory. |
| 902 | * |
| 903 | * Source and destination must either both be directories, or both |
| 904 | * not be directories. If target is a directory, it must be empty. |
| 905 | */ |
| 906 | rename() |
| 907 | { |
| 908 | struct a { |
| 909 | char *from; |
| 910 | char *to; |
| 911 | } *uap; |
| 912 | register struct inode *ip, *xp, *dp; |
| 913 | int oldparent, parentdifferent, doingdirectory; |
| 914 | int error = 0; |
| 915 | |
| 916 | uap = (struct a *)u.u_ap; |
| 917 | ip = namei(uchar, LOOKUP | LOCKPARENT, 0); |
| 918 | if (ip == NULL) |
| 919 | return; |
| 920 | dp = u.u_pdir; |
| 921 | oldparent = 0, doingdirectory = 0; |
| 922 | if ((ip->i_mode&IFMT) == IFDIR) { |
| 923 | register struct direct *d; |
| 924 | |
| 925 | d = &u.u_dent; |
| 926 | /* |
| 927 | * Avoid "." and ".." for obvious reasons. |
| 928 | */ |
| 929 | if (d->d_name[0] == '.') { |
| 930 | if (d->d_namlen == 1 || |
| 931 | (d->d_namlen == 2 && d->d_name[1] == '.')) { |
| 932 | iput(ip); |
| 933 | u.u_error = EINVAL; |
| 934 | return; |
| 935 | } |
| 936 | } |
| 937 | oldparent = dp->i_number; |
| 938 | doingdirectory++; |
| 939 | } |
| 940 | irele(dp); |
| 941 | |
| 942 | /* |
| 943 | * 1) Bump link count while we're moving stuff |
| 944 | * around. If we crash somewhere before |
| 945 | * completing our work, the link count |
| 946 | * may be wrong, but correctable. |
| 947 | */ |
| 948 | ip->i_nlink++; |
| 949 | ip->i_flag |= ICHG; |
| 950 | iupdat(ip, &time, &time, 1); |
| 951 | iunlock(ip); |
| 952 | |
| 953 | /* |
| 954 | * When the target exists, both the directory |
| 955 | * and target inodes are returned locked. |
| 956 | */ |
| 957 | u.u_dirp = (caddr_t)uap->to; |
| 958 | xp = namei(uchar, CREATE | LOCKPARENT, 0); |
| 959 | if (u.u_error) { |
| 960 | error = u.u_error; |
| 961 | goto out; |
| 962 | } |
| 963 | dp = u.u_pdir; |
| 964 | /* |
| 965 | * 2) If target doesn't exist, link the target |
| 966 | * to the source and unlink the source. |
| 967 | * Otherwise, rewrite the target directory |
| 968 | * entry to reference the source inode and |
| 969 | * expunge the original entry's existence. |
| 970 | */ |
| 971 | parentdifferent = oldparent != dp->i_number; |
| 972 | if (xp == NULL) { |
| 973 | if (dp->i_dev != ip->i_dev) { |
| 974 | error = EXDEV; |
| 975 | goto bad; |
| 976 | } |
| 977 | /* |
| 978 | * Disallow rename(foo, foo/bar). |
| 979 | */ |
| 980 | if (dp->i_number == ip->i_number) { |
| 981 | error = EEXIST; |
| 982 | goto bad; |
| 983 | } |
| 984 | /* |
| 985 | * Account for ".." in directory. |
| 986 | * When source and destination have the |
| 987 | * same parent we don't fool with the |
| 988 | * link count -- this isn't required |
| 989 | * because we do a similar check below. |
| 990 | */ |
| 991 | if (doingdirectory && parentdifferent) { |
| 992 | dp->i_nlink++; |
| 993 | dp->i_flag |= ICHG; |
| 994 | iupdat(dp, &time, &time, 1); |
| 995 | } |
| 996 | error = direnter(ip); |
| 997 | if (error) |
| 998 | goto out; |
| 999 | } else { |
| 1000 | if (xp->i_dev != dp->i_dev || xp->i_dev != ip->i_dev) { |
| 1001 | error = EXDEV; |
| 1002 | goto bad; |
| 1003 | } |
| 1004 | /* |
| 1005 | * Short circuit rename(foo, foo). |
| 1006 | */ |
| 1007 | if (xp->i_number == ip->i_number) |
| 1008 | goto bad; |
| 1009 | /* |
| 1010 | * Target must be empty if a directory |
| 1011 | * and have no links to it. |
| 1012 | * Also, insure source and target are |
| 1013 | * compatible (both directories, or both |
| 1014 | * not directories). |
| 1015 | */ |
| 1016 | if ((xp->i_mode&IFMT) == IFDIR) { |
| 1017 | if (!dirempty(xp) || xp->i_nlink > 2) { |
| 1018 | error = ENOTEMPTY; |
| 1019 | goto bad; |
| 1020 | } |
| 1021 | if (!doingdirectory) { |
| 1022 | error = ENOTDIR; |
| 1023 | goto bad; |
| 1024 | } |
| 1025 | } else if (doingdirectory) { |
| 1026 | error = EISDIR; |
| 1027 | goto bad; |
| 1028 | } |
| 1029 | dirrewrite(dp, ip); |
| 1030 | if (u.u_error) { |
| 1031 | error = u.u_error; |
| 1032 | goto bad1; |
| 1033 | } |
| 1034 | /* |
| 1035 | * Adjust the link count of the target to |
| 1036 | * reflect the dirrewrite above. If this is |
| 1037 | * a directory it is empty and there are |
| 1038 | * no links to it, so we can squash the inode and |
| 1039 | * any space associated with it. We disallowed |
| 1040 | * renaming over top of a directory with links to |
| 1041 | * it above, as we've no way to determine if |
| 1042 | * we've got a link or the directory itself, and |
| 1043 | * if we get a link, then ".." will be screwed up. |
| 1044 | */ |
| 1045 | xp->i_nlink--; |
| 1046 | if (doingdirectory) { |
| 1047 | if (--xp->i_nlink != 0) |
| 1048 | panic("rename: linked directory"); |
| 1049 | itrunc(xp, (u_long)0); |
| 1050 | } |
| 1051 | xp->i_flag |= ICHG; |
| 1052 | iput(xp); |
| 1053 | xp = NULL; |
| 1054 | } |
| 1055 | |
| 1056 | /* |
| 1057 | * 3) Unlink the source. |
| 1058 | */ |
| 1059 | u.u_dirp = uap->from; |
| 1060 | dp = namei(uchar, DELETE, 0); |
| 1061 | /* |
| 1062 | * Insure directory entry still exists and |
| 1063 | * has not changed since the start of all |
| 1064 | * this. If either has occured, forget about |
| 1065 | * about deleting the original entry and just |
| 1066 | * adjust the link count in the inode. |
| 1067 | */ |
| 1068 | if (dp == NULL || u.u_dent.d_ino != ip->i_number) { |
| 1069 | ip->i_nlink--; |
| 1070 | ip->i_flag |= ICHG; |
| 1071 | } else { |
| 1072 | /* |
| 1073 | * If source is a directory, must adjust |
| 1074 | * link count of parent directory also. |
| 1075 | * If target didn't exist and source and |
| 1076 | * target have the same parent, then we |
| 1077 | * needn't touch the link count, it all |
| 1078 | * balances out in the end. Otherwise, we |
| 1079 | * must do so to reflect deletion of ".." |
| 1080 | * done above. |
| 1081 | */ |
| 1082 | if (doingdirectory && (xp != NULL || parentdifferent)) { |
| 1083 | dp->i_nlink--; |
| 1084 | dp->i_flag |= ICHG; |
| 1085 | } |
| 1086 | if (dirremove()) { |
| 1087 | ip->i_nlink--; |
| 1088 | ip->i_flag |= ICHG; |
| 1089 | } |
| 1090 | if (error == 0) /* conservative */ |
| 1091 | error = u.u_error; |
| 1092 | } |
| 1093 | irele(ip); |
| 1094 | if (dp) |
| 1095 | iput(dp); |
| 1096 | |
| 1097 | /* |
| 1098 | * 4) Renaming a directory with the parent |
| 1099 | * different requires ".." to be rewritten. |
| 1100 | * The window is still there for ".." to |
| 1101 | * be inconsistent, but this is unavoidable, |
| 1102 | * and a lot shorter than when it was done |
| 1103 | * in a user process. |
| 1104 | */ |
| 1105 | if (doingdirectory && parentdifferent && error == 0) { |
| 1106 | struct dirtemplate dirbuf; |
| 1107 | |
| 1108 | u.u_dirp = uap->to; |
| 1109 | ip = namei(uchar, LOOKUP | LOCKPARENT, 0); |
| 1110 | if (ip == NULL) { |
| 1111 | printf("rename: .. went away\n"); |
| 1112 | return; |
| 1113 | } |
| 1114 | dp = u.u_pdir; |
| 1115 | if ((ip->i_mode&IFMT) != IFDIR) { |
| 1116 | printf("rename: .. not a directory\n"); |
| 1117 | goto stuck; |
| 1118 | } |
| 1119 | error = rdwri(UIO_READ, ip, (caddr_t)&dirbuf, |
| 1120 | sizeof (struct dirtemplate), (off_t)0, 1, (int *)0); |
| 1121 | if (error == 0) { |
| 1122 | dirbuf.dotdot_ino = dp->i_number; |
| 1123 | (void) rdwri(UIO_WRITE, ip, (caddr_t)&dirbuf, |
| 1124 | sizeof (struct dirtemplate), (off_t)0, 1, (int *)0); |
| 1125 | } |
| 1126 | stuck: |
| 1127 | irele(dp); |
| 1128 | iput(ip); |
| 1129 | } |
| 1130 | goto done; |
| 1131 | |
| 1132 | bad: |
| 1133 | iput(dp); |
| 1134 | bad1: |
| 1135 | if (xp) |
| 1136 | iput(xp); |
| 1137 | out: |
| 1138 | ip->i_nlink--; |
| 1139 | ip->i_flag |= ICHG; |
| 1140 | irele(ip); |
| 1141 | done: |
| 1142 | if (error) |
| 1143 | u.u_error = error; |
| 1144 | } |
| 1145 | |
| 1146 | /* |
| 1147 | * Make a new file. |
| 1148 | */ |
| 1149 | struct inode * |
| 1150 | maknode(mode) |
| 1151 | int mode; |
| 1152 | { |
| 1153 | register struct inode *ip; |
| 1154 | ino_t ipref; |
| 1155 | |
| 1156 | if ((mode & IFMT) == IFDIR) |
| 1157 | ipref = dirpref(u.u_pdir->i_fs); |
| 1158 | else |
| 1159 | ipref = u.u_pdir->i_number; |
| 1160 | ip = ialloc(u.u_pdir, ipref, mode); |
| 1161 | if (ip == NULL) { |
| 1162 | iput(u.u_pdir); |
| 1163 | return (NULL); |
| 1164 | } |
| 1165 | #ifdef QUOTA |
| 1166 | if (ip->i_dquot != NODQUOT) |
| 1167 | panic("maknode: dquot"); |
| 1168 | #endif |
| 1169 | ip->i_flag |= IACC|IUPD|ICHG; |
| 1170 | if ((mode & IFMT) == 0) |
| 1171 | mode |= IFREG; |
| 1172 | ip->i_mode = mode & ~u.u_cmask; |
| 1173 | ip->i_nlink = 1; |
| 1174 | ip->i_uid = u.u_uid; |
| 1175 | ip->i_gid = u.u_pdir->i_gid; |
| 1176 | #ifdef QUOTA |
| 1177 | ip->i_dquot = inoquota(ip); |
| 1178 | #endif |
| 1179 | |
| 1180 | /* |
| 1181 | * Make sure inode goes to disk before directory entry. |
| 1182 | */ |
| 1183 | iupdat(ip, &time, &time, 1); |
| 1184 | u.u_error = direnter(ip); |
| 1185 | if (u.u_error) { |
| 1186 | /* |
| 1187 | * Write error occurred trying to update directory |
| 1188 | * so must deallocate the inode. |
| 1189 | */ |
| 1190 | ip->i_nlink = 0; |
| 1191 | ip->i_flag |= ICHG; |
| 1192 | iput(ip); |
| 1193 | return (NULL); |
| 1194 | } |
| 1195 | return (ip); |
| 1196 | } |