1 /* ufs_vnops.c 4.44 82/12/19 */ 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 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_mtime = ip->i_mtime; 500 ds.st_ctime = ip->i_ctime; 501 /* this doesn't belong here */ 502 if ((ip->i_mode&IFMT) == IFBLK) 503 ds.st_blksize = BLKDEV_IOSIZE; 504 else if ((ip->i_mode&IFMT) == IFCHR) 505 ds.st_blksize = MAXBSIZE; 506 else 507 ds.st_blksize = ip->i_fs->fs_bsize; 508 if (copyout((caddr_t)&ds, (caddr_t)ub, sizeof(ds)) < 0) 509 u.u_error = EFAULT; 510 } 511 512 /* 513 * Return target name of a symbolic link 514 */ 515 readlink() 516 { 517 register struct inode *ip; 518 register struct a { 519 char *name; 520 char *buf; 521 int count; 522 } *uap = (struct a *)u.u_ap; 523 int resid; 524 525 ip = namei(uchar, LOOKUP, 0); 526 if (ip == NULL) 527 return; 528 if ((ip->i_mode&IFMT) != IFLNK) { 529 u.u_error = ENXIO; 530 goto out; 531 } 532 u.u_error = rdwri(UIO_READ, ip, uap->buf, uap->count, 0, 0, &resid); 533 out: 534 iput(ip); 535 u.u_r.r_val1 = uap->count - resid; 536 } 537 538 /* 539 * Change mode of a file given path name. 540 */ 541 chmod() 542 { 543 struct inode *ip; 544 struct a { 545 char *fname; 546 int fmode; 547 } *uap; 548 549 uap = (struct a *)u.u_ap; 550 if ((ip = owner(1)) == NULL) 551 return; 552 chmod1(ip, uap->fmode); 553 iput(ip); 554 } 555 556 /* 557 * Change mode of a file given a file descriptor. 558 */ 559 fchmod() 560 { 561 struct a { 562 int fd; 563 int fmode; 564 } *uap; 565 register struct inode *ip; 566 register struct file *fp; 567 568 uap = (struct a *)u.u_ap; 569 fp = getf(uap->fd); 570 if (fp == NULL) 571 return; 572 if (fp->f_type == DTYPE_SOCKET) { 573 u.u_error = EINVAL; 574 return; 575 } 576 ip = fp->f_inode; 577 if (u.u_uid != ip->i_uid && !suser()) 578 return; 579 ilock(ip); 580 chmod1(ip, uap->fmode); 581 iunlock(ip); 582 } 583 584 /* 585 * Change the mode on a file. 586 * Inode must be locked before calling. 587 */ 588 chmod1(ip, mode) 589 register struct inode *ip; 590 register int mode; 591 { 592 register int *gp; 593 594 ip->i_mode &= ~07777; 595 if (u.u_uid) { 596 mode &= ~ISVTX; 597 for (gp = u.u_groups; gp < &u.u_groups[NGROUPS]; gp++) 598 if (*gp == ip->i_gid) 599 goto ok; 600 mode &= ~ISGID; 601 ok: 602 ; 603 #ifdef MUSH 604 if (u.u_quota->q_syflags & QF_UMASK && u.u_uid != 0 && 605 (ip->i_mode & IFMT) != IFCHR) 606 mode &= ~u.u_cmask; 607 #endif 608 } 609 ip->i_mode |= mode&07777; 610 ip->i_flag |= ICHG; 611 if (ip->i_flag&ITEXT && (ip->i_mode&ISVTX)==0) 612 xrele(ip); 613 } 614 615 /* 616 * Set ownership given a path name. 617 */ 618 chown() 619 { 620 struct inode *ip; 621 struct a { 622 char *fname; 623 int uid; 624 int gid; 625 } *uap; 626 627 uap = (struct a *)u.u_ap; 628 if (!suser() || (ip = owner(0)) == NULL) 629 return; 630 chown1(ip, uap->uid, uap->gid); 631 iput(ip); 632 } 633 634 /* 635 * Set ownership given a file descriptor. 636 */ 637 fchown() 638 { 639 struct a { 640 int fd; 641 int uid; 642 int gid; 643 } *uap; 644 register struct inode *ip; 645 register struct file *fp; 646 647 uap = (struct a *)u.u_ap; 648 fp = getf(uap->fd); 649 if (fp == NULL) 650 return; 651 if (fp->f_type == DTYPE_SOCKET) { 652 u.u_error = EINVAL; 653 return; 654 } 655 ip = fp->f_inode; 656 if (!suser()) 657 return; 658 ilock(ip); 659 chown1(ip, uap->uid, uap->gid); 660 iunlock(ip); 661 } 662 663 /* 664 * Perform chown operation on inode ip; 665 * inode must be locked prior to call. 666 */ 667 chown1(ip, uid, gid) 668 register struct inode *ip; 669 int uid, gid; 670 { 671 #ifdef QUOTA 672 register long change; 673 674 /* 675 * This doesn't allow for holes in files (which hopefully don't 676 * happen often in files that we chown), and is not accurate anyway 677 * (eg: it totally ignores 3 level indir blk files - but hopefully 678 * noone who can make a file that big will have a quota) 679 */ 680 if (ip->i_uid == uid) 681 change = 0; 682 else { 683 register struct fs *fs = ip->i_fs; 684 685 if (ip->i_size > (change = NDADDR * fs->fs_bsize)) { 686 register off_t size; 687 688 size = blkroundup(fs, ip->i_size) - change; 689 change += size; 690 change += fs->fs_bsize; 691 /* this assumes NIADDR <= 2 */ 692 if (size > NINDIR(fs) * fs->fs_bsize) 693 change += fs->fs_bsize; 694 } else 695 change = fragroundup(fs, ip->i_size); 696 change /= DEV_BSIZE; 697 } 698 (void)chkdq(ip, -change, 1); 699 (void)chkiq(ip->i_dev, ip, ip->i_uid, 1); 700 dqrele(ip->i_dquot); 701 #endif 702 /* 703 * keep uid/gid's in sane range -- no err, 704 * so chown(file, uid, -1) will do something useful 705 */ 706 if (uid >= 0 && uid <= 32767) /* should have a constant */ 707 ip->i_uid = uid; 708 if (gid >= 0 && gid <= 32767) /* same here */ 709 ip->i_gid = gid; 710 ip->i_flag |= ICHG; 711 if (u.u_ruid != 0) 712 ip->i_mode &= ~(ISUID|ISGID); 713 #ifdef QUOTA 714 ip->i_dquot = inoquota(ip); 715 (void)chkdq(ip, change, 1); 716 (void)chkiq(ip->i_dev, (struct inode *)NULL, uid, 1); 717 #endif 718 } 719 720 /* 721 * Set IUPD and IACC times on file. 722 * Can't set ICHG. 723 */ 724 outime() 725 { 726 register struct a { 727 char *fname; 728 time_t *tptr; 729 } *uap; 730 register struct inode *ip; 731 time_t tv[2]; 732 struct timeval tv0, tv1; 733 734 uap = (struct a *)u.u_ap; 735 if ((ip = owner(1)) == NULL) 736 return; 737 if (copyin((caddr_t)uap->tptr, (caddr_t)tv, sizeof(tv))) { 738 u.u_error = EFAULT; 739 } else { 740 ip->i_flag |= IACC|IUPD|ICHG; 741 tv0.tv_sec = tv[0]; tv0.tv_usec = 0; 742 tv1.tv_sec = tv[1]; tv1.tv_usec = 0; 743 iupdat(ip, &tv0, &tv1, 0); 744 } 745 iput(ip); 746 } 747 748 /* 749 * Flush any pending I/O. 750 */ 751 sync() 752 { 753 754 update(); 755 } 756 757 /* 758 * Apply an advisory lock on a file descriptor. 759 */ 760 flock() 761 { 762 struct a { 763 int fd; 764 int how; 765 } *uap; 766 register struct file *fp; 767 register int cmd, flags; 768 769 uap = (struct a *)u.u_ap; 770 fp = getf(uap->fd); 771 if (fp == NULL) 772 return; 773 if (fp->f_type == DTYPE_SOCKET) { /* XXX */ 774 u.u_error = EINVAL; 775 return; 776 } 777 cmd = uap->how; 778 flags = u.u_pofile[uap->fd] & (UF_SHLOCK|UF_EXLOCK); 779 if (cmd&FUNLOCK) { 780 if (flags == 0) { 781 u.u_error = EINVAL; 782 return; 783 } 784 funlocki(fp->f_inode, flags); 785 u.u_pofile[uap->fd] &= ~(UF_SHLOCK|UF_EXLOCK); 786 return; 787 } 788 /* 789 * No reason to write lock a file we've already 790 * write locked, similarly with a read lock. 791 */ 792 if ((flags&UF_EXLOCK) && (cmd&FEXLOCK) || 793 (flags&UF_SHLOCK) && (cmd&FSHLOCK)) 794 return; 795 u.u_pofile[uap->fd] = flocki(fp->f_inode, u.u_pofile[uap->fd], cmd); 796 } 797 798 /* 799 * Truncate a file given its path name. 800 */ 801 truncate() 802 { 803 struct a { 804 char *fname; 805 u_long length; 806 } *uap = (struct a *)u.u_ap; 807 struct inode *ip; 808 809 ip = namei(uchar, LOOKUP, 1); 810 if (ip == NULL) 811 return; 812 if (access(ip, IWRITE)) 813 goto bad; 814 if ((ip->i_mode&IFMT) == IFDIR) { 815 u.u_error = EISDIR; 816 goto bad; 817 } 818 itrunc(ip, uap->length); 819 bad: 820 iput(ip); 821 } 822 823 /* 824 * Truncate a file given a file descriptor. 825 */ 826 ftruncate() 827 { 828 struct a { 829 int fd; 830 u_long length; 831 } *uap = (struct a *)u.u_ap; 832 struct inode *ip; 833 struct file *fp; 834 835 fp = getf(uap->fd); 836 if (fp == NULL) 837 return; 838 if (fp->f_type == DTYPE_SOCKET) { 839 u.u_error = EINVAL; 840 return; 841 } 842 if ((fp->f_flag&FWRITE) == 0) { 843 u.u_error = EINVAL; 844 return; 845 } 846 ip = fp->f_inode; 847 ilock(ip); 848 itrunc(ip, uap->length); 849 iunlock(ip); 850 } 851 852 /* 853 * Synch an open file. 854 */ 855 fsync() 856 { 857 struct a { 858 int fd; 859 } *uap = (struct a *)u.u_ap; 860 struct inode *ip; 861 struct file *fp; 862 863 fp = getf(uap->fd); 864 if (fp == NULL) 865 return; 866 if (fp->f_type == DTYPE_SOCKET) { 867 u.u_error = EINVAL; 868 return; 869 } 870 ip = fp->f_inode; 871 ilock(ip); 872 syncip(ip); 873 iunlock(ip); 874 } 875 876 /* 877 * Rename system call. 878 * rename("foo", "bar"); 879 * is essentially 880 * unlink("bar"); 881 * link("foo", "bar"); 882 * unlink("foo"); 883 * but ``atomically''. Can't do full commit without saving state in the 884 * inode on disk which isn't feasible at this time. Best we can do is 885 * always guarantee the target exists. 886 * 887 * Basic algorithm is: 888 * 889 * 1) Bump link count on source while we're linking it to the 890 * target. This also insure the inode won't be deleted out 891 * from underneath us while we work. 892 * 2) Link source to destination. If destination already exists, 893 * delete it first. 894 * 3) Unlink source reference to inode if still around. 895 * 4) If a directory was moved and the parent of the destination 896 * is different from the source, patch the ".." entry in the 897 * directory. 898 * 899 * Source and destination must either both be directories, or both 900 * not be directories. If target is a directory, it must be empty. 901 */ 902 rename() 903 { 904 struct a { 905 char *from; 906 char *to; 907 } *uap; 908 register struct inode *ip, *xp, *dp; 909 int oldparent, parentdifferent, doingdirectory; 910 911 uap = (struct a *)u.u_ap; 912 ip = namei(uchar, LOOKUP | LOCKPARENT, 0); 913 if (ip == NULL) 914 return; 915 dp = u.u_pdir; 916 oldparent = 0, doingdirectory = 0; 917 if ((ip->i_mode&IFMT) == IFDIR) { 918 register struct direct *d; 919 920 d = &u.u_dent; 921 /* 922 * Avoid "." and ".." for obvious reasons. 923 */ 924 if (d->d_name[0] == '.') { 925 if (d->d_namlen == 1 || 926 (d->d_namlen == 2 && d->d_name[1] == '.')) { 927 u.u_error = EINVAL; 928 iput(ip); 929 return; 930 } 931 } 932 oldparent = dp->i_number; 933 doingdirectory++; 934 } 935 irele(dp); 936 937 /* 938 * 1) Bump link count while we're moving stuff 939 * around. If we crash somewhere before 940 * completing our work, the link count 941 * may be wrong, but correctable. 942 */ 943 ip->i_nlink++; 944 ip->i_flag |= ICHG; 945 iupdat(ip, &time, &time, 1); 946 iunlock(ip); 947 948 /* 949 * When the target exists, both the directory 950 * and target inodes are returned locked. 951 */ 952 u.u_dirp = (caddr_t)uap->to; 953 xp = namei(uchar, CREATE | LOCKPARENT, 0); 954 if (u.u_error) 955 goto out; 956 dp = u.u_pdir; 957 /* 958 * 2) If target doesn't exist, link the target 959 * to the source and unlink the source. 960 * Otherwise, rewrite the target directory 961 * entry to reference the source inode and 962 * expunge the original entry's existence. 963 */ 964 parentdifferent = oldparent != dp->i_number; 965 if (xp == NULL) { 966 if (dp->i_dev != ip->i_dev) { 967 u.u_error = EXDEV; 968 goto bad; 969 } 970 /* 971 * Account for ".." in directory. 972 * When source and destination have the 973 * same parent we don't fool with the 974 * link count -- this isn't required 975 * because we do a similar check below. 976 */ 977 if (doingdirectory && parentdifferent) { 978 dp->i_nlink++; 979 dp->i_flag |= ICHG; 980 iupdat(dp, &time, &time, 1); 981 } 982 direnter(ip); 983 if (u.u_error) 984 goto out; 985 } else { 986 if (xp->i_dev != dp->i_dev || xp->i_dev != ip->i_dev) { 987 u.u_error = EXDEV; 988 goto bad; 989 } 990 /* 991 * Target must be empty if a directory. 992 * Also, insure source and target are 993 * compatible (both directories, or both 994 * not directories). 995 */ 996 if ((xp->i_mode&IFMT) == IFDIR) { 997 if (!dirempty(xp)) { 998 u.u_error = ENOTEMPTY; 999 goto bad; 1000 } 1001 if (!doingdirectory) { 1002 u.u_error = ENOTDIR; 1003 goto bad; 1004 } 1005 } else if (doingdirectory) { 1006 u.u_error = EISDIR; 1007 goto bad; 1008 } 1009 dirrewrite(dp, ip); 1010 if (u.u_error) 1011 goto bad1; 1012 /* 1013 * If this is a directory we know it is 1014 * empty and we can squash the inode and 1015 * any space associated with it. Otherwise, 1016 * we've got a plain file and the link count 1017 * simply needs to be adjusted. 1018 */ 1019 if (doingdirectory) { 1020 xp->i_nlink = 0; 1021 itrunc(xp, (u_long)0); 1022 } else 1023 xp->i_nlink--; 1024 xp->i_flag |= ICHG; 1025 iput(xp); 1026 } 1027 1028 /* 1029 * 3) Unlink the source. 1030 */ 1031 u.u_dirp = uap->from; 1032 dp = namei(uchar, DELETE, 0); 1033 /* 1034 * Insure directory entry still exists and 1035 * has not changed since the start of all 1036 * this. If either has occured, forget about 1037 * about deleting the original entry and just 1038 * adjust the link count in the inode. 1039 */ 1040 if (dp == NULL || u.u_dent.d_ino != ip->i_number) { 1041 ip->i_nlink--; 1042 ip->i_flag |= ICHG; 1043 } else { 1044 /* 1045 * If source is a directory, must adjust 1046 * link count of parent directory also. 1047 * If target didn't exist and source and 1048 * target have the same parent, then we 1049 * needn't touch the link count, it all 1050 * balances out in the end. Otherwise, we 1051 * must do so to reflect deletion of ".." 1052 * done above. 1053 */ 1054 if (doingdirectory && (xp != NULL || parentdifferent)) { 1055 dp->i_nlink--; 1056 dp->i_flag |= ICHG; 1057 } 1058 if (dirremove()) { 1059 ip->i_nlink--; 1060 ip->i_flag |= ICHG; 1061 } 1062 } 1063 irele(ip); 1064 if (dp) 1065 iput(dp); 1066 1067 /* 1068 * 4) Renaming a directory with the parent 1069 * different requires ".." to be rewritten. 1070 * The window is still there for ".." to 1071 * be inconsistent, but this is unavoidable, 1072 * and a lot shorter than when it was done 1073 * in a user process. 1074 */ 1075 if (doingdirectory && parentdifferent && u.u_error == 0) { 1076 struct dirtemplate dirbuf; 1077 1078 u.u_dirp = uap->to; 1079 ip = namei(uchar, LOOKUP | LOCKPARENT, 0); 1080 if (ip == NULL) { 1081 printf("rename: .. went away\n"); 1082 return; 1083 } 1084 dp = u.u_pdir; 1085 if ((ip->i_mode&IFMT) != IFDIR) { 1086 printf("rename: .. not a directory\n"); 1087 goto stuck; 1088 } 1089 u.u_error = rdwri(UIO_READ, ip, (caddr_t)&dirbuf, 1090 sizeof (struct dirtemplate), (off_t)0, 1, (int *)0); 1091 if (u.u_error == 0) { 1092 dirbuf.dotdot_ino = dp->i_number; 1093 (void) rdwri(UIO_WRITE, ip, (caddr_t)&dirbuf, 1094 sizeof (struct dirtemplate), (off_t)0, 1, (int *)0); 1095 } 1096 stuck: 1097 irele(dp); 1098 iput(ip); 1099 } 1100 return; 1101 bad: 1102 iput(u.u_pdir); 1103 bad1: 1104 if (xp) 1105 irele(xp); 1106 out: 1107 ip->i_nlink--; 1108 ip->i_flag |= ICHG; 1109 irele(ip); 1110 } 1111 1112 /* 1113 * Make a new file. 1114 */ 1115 struct inode * 1116 maknode(mode) 1117 int mode; 1118 { 1119 register struct inode *ip; 1120 ino_t ipref; 1121 1122 if ((mode & IFMT) == IFDIR) 1123 ipref = dirpref(u.u_pdir->i_fs); 1124 else 1125 ipref = u.u_pdir->i_number; 1126 ip = ialloc(u.u_pdir, ipref, mode); 1127 if (ip == NULL) { 1128 iput(u.u_pdir); 1129 return (NULL); 1130 } 1131 #ifdef QUOTA 1132 if (ip->i_dquot != NODQUOT) 1133 panic("maknode: dquot"); 1134 #endif 1135 ip->i_flag |= IACC|IUPD|ICHG; 1136 if ((mode & IFMT) == 0) 1137 mode |= IFREG; 1138 ip->i_mode = mode & ~u.u_cmask; 1139 ip->i_nlink = 1; 1140 ip->i_uid = u.u_uid; 1141 ip->i_gid = u.u_pdir->i_gid; 1142 #ifdef QUOTA 1143 ip->i_dquot = inoquota(ip); 1144 #endif 1145 1146 /* 1147 * Make sure inode goes to disk before directory entry. 1148 */ 1149 iupdat(ip, &time, &time, 1); 1150 direnter(ip); 1151 if (u.u_error) { 1152 /* 1153 * write error occurred trying to update directory 1154 * so must deallocate the inode 1155 */ 1156 ip->i_nlink = 0; 1157 ip->i_flag |= ICHG; 1158 iput(ip); 1159 return (NULL); 1160 } 1161 return (ip); 1162 } 1163