1 /* ffs_vnops.c 4.47 83/01/01 */ 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_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 for (gp = u.u_groups; gp < &u.u_groups[NGROUPS]; gp++) 601 if (*gp == ip->i_gid) 602 goto ok; 603 mode &= ~ISGID; 604 ok: 605 ; 606 #ifdef MUSH 607 if (u.u_quota->q_syflags & QF_UMASK && u.u_uid != 0 && 608 (ip->i_mode & IFMT) != IFCHR) 609 mode &= ~u.u_cmask; 610 #endif 611 } 612 ip->i_mode |= mode&07777; 613 ip->i_flag |= ICHG; 614 if (ip->i_flag&ITEXT && (ip->i_mode&ISVTX)==0) 615 xrele(ip); 616 } 617 618 /* 619 * Set ownership given a path name. 620 */ 621 chown() 622 { 623 struct inode *ip; 624 struct a { 625 char *fname; 626 int uid; 627 int gid; 628 } *uap; 629 630 uap = (struct a *)u.u_ap; 631 if (!suser() || (ip = owner(0)) == NULL) 632 return; 633 chown1(ip, uap->uid, uap->gid); 634 iput(ip); 635 } 636 637 /* 638 * Set ownership given a file descriptor. 639 */ 640 fchown() 641 { 642 struct a { 643 int fd; 644 int uid; 645 int gid; 646 } *uap; 647 register struct inode *ip; 648 register struct file *fp; 649 650 uap = (struct a *)u.u_ap; 651 fp = getf(uap->fd); 652 if (fp == NULL) 653 return; 654 if (fp->f_type == DTYPE_SOCKET) { 655 u.u_error = EINVAL; 656 return; 657 } 658 ip = fp->f_inode; 659 if (!suser()) 660 return; 661 ilock(ip); 662 chown1(ip, uap->uid, uap->gid); 663 iunlock(ip); 664 } 665 666 /* 667 * Perform chown operation on inode ip; 668 * inode must be locked prior to call. 669 */ 670 chown1(ip, uid, gid) 671 register struct inode *ip; 672 int uid, gid; 673 { 674 #ifdef QUOTA 675 register long change; 676 677 /* 678 * This doesn't allow for holes in files (which hopefully don't 679 * happen often in files that we chown), and is not accurate anyway 680 * (eg: it totally ignores 3 level indir blk files - but hopefully 681 * noone who can make a file that big will have a quota) 682 */ 683 if (ip->i_uid == uid) 684 change = 0; 685 else { 686 register struct fs *fs = ip->i_fs; 687 688 if (ip->i_size > (change = NDADDR * fs->fs_bsize)) { 689 register off_t size; 690 691 size = blkroundup(fs, ip->i_size) - change; 692 change += size; 693 change += fs->fs_bsize; 694 /* this assumes NIADDR <= 2 */ 695 if (size > NINDIR(fs) * fs->fs_bsize) 696 change += fs->fs_bsize; 697 } else 698 change = fragroundup(fs, ip->i_size); 699 change /= DEV_BSIZE; 700 } 701 (void)chkdq(ip, -change, 1); 702 (void)chkiq(ip->i_dev, ip, ip->i_uid, 1); 703 dqrele(ip->i_dquot); 704 #endif 705 /* 706 * keep uid/gid's in sane range -- no err, 707 * so chown(file, uid, -1) will do something useful 708 */ 709 if (uid >= 0 && uid <= 32767) /* should have a constant */ 710 ip->i_uid = uid; 711 if (gid >= 0 && gid <= 32767) /* same here */ 712 ip->i_gid = gid; 713 ip->i_flag |= ICHG; 714 if (u.u_ruid != 0) 715 ip->i_mode &= ~(ISUID|ISGID); 716 #ifdef QUOTA 717 ip->i_dquot = inoquota(ip); 718 (void)chkdq(ip, change, 1); 719 (void)chkiq(ip->i_dev, (struct inode *)NULL, uid, 1); 720 #endif 721 } 722 723 /* 724 * Set IUPD and IACC times on file. 725 * Can't set ICHG. 726 */ 727 outime() 728 { 729 register struct a { 730 char *fname; 731 time_t *tptr; 732 } *uap; 733 register struct inode *ip; 734 time_t tv[2]; 735 struct timeval tv0, tv1; 736 737 uap = (struct a *)u.u_ap; 738 if ((ip = owner(1)) == NULL) 739 return; 740 u.u_error = copyin((caddr_t)uap->tptr, (caddr_t)tv, sizeof(tv)); 741 if (u.u_error == 0) { 742 ip->i_flag |= IACC|IUPD|ICHG; 743 tv0.tv_sec = tv[0]; tv0.tv_usec = 0; 744 tv1.tv_sec = tv[1]; tv1.tv_usec = 0; 745 iupdat(ip, &tv0, &tv1, 0); 746 } 747 iput(ip); 748 } 749 750 /* 751 * Flush any pending I/O. 752 */ 753 sync() 754 { 755 756 update(); 757 } 758 759 /* 760 * Apply an advisory lock on a file descriptor. 761 */ 762 flock() 763 { 764 struct a { 765 int fd; 766 int how; 767 } *uap; 768 register struct file *fp; 769 register int cmd, flags; 770 771 uap = (struct a *)u.u_ap; 772 fp = getf(uap->fd); 773 if (fp == NULL) 774 return; 775 if (fp->f_type == DTYPE_SOCKET) { /* XXX */ 776 u.u_error = EINVAL; 777 return; 778 } 779 cmd = uap->how; 780 flags = u.u_pofile[uap->fd] & (UF_SHLOCK|UF_EXLOCK); 781 if (cmd&FUNLOCK) { 782 if (flags == 0) { 783 u.u_error = EINVAL; 784 return; 785 } 786 funlocki(fp->f_inode, flags); 787 u.u_pofile[uap->fd] &= ~(UF_SHLOCK|UF_EXLOCK); 788 return; 789 } 790 /* 791 * No reason to write lock a file we've already 792 * write locked, similarly with a read lock. 793 */ 794 if ((flags&UF_EXLOCK) && (cmd&FEXLOCK) || 795 (flags&UF_SHLOCK) && (cmd&FSHLOCK)) 796 return; 797 u.u_pofile[uap->fd] = flocki(fp->f_inode, u.u_pofile[uap->fd], cmd); 798 } 799 800 /* 801 * Truncate a file given its path name. 802 */ 803 truncate() 804 { 805 struct a { 806 char *fname; 807 u_long length; 808 } *uap = (struct a *)u.u_ap; 809 struct inode *ip; 810 811 ip = namei(uchar, LOOKUP, 1); 812 if (ip == NULL) 813 return; 814 if (access(ip, IWRITE)) 815 goto bad; 816 if ((ip->i_mode&IFMT) == IFDIR) { 817 u.u_error = EISDIR; 818 goto bad; 819 } 820 itrunc(ip, uap->length); 821 bad: 822 iput(ip); 823 } 824 825 /* 826 * Truncate a file given a file descriptor. 827 */ 828 ftruncate() 829 { 830 struct a { 831 int fd; 832 u_long length; 833 } *uap = (struct a *)u.u_ap; 834 struct inode *ip; 835 struct file *fp; 836 837 fp = getf(uap->fd); 838 if (fp == NULL) 839 return; 840 if (fp->f_type == DTYPE_SOCKET) { 841 u.u_error = EINVAL; 842 return; 843 } 844 if ((fp->f_flag&FWRITE) == 0) { 845 u.u_error = EINVAL; 846 return; 847 } 848 ip = fp->f_inode; 849 ilock(ip); 850 itrunc(ip, uap->length); 851 iunlock(ip); 852 } 853 854 /* 855 * Synch an open file. 856 */ 857 fsync() 858 { 859 struct a { 860 int fd; 861 } *uap = (struct a *)u.u_ap; 862 struct inode *ip; 863 struct file *fp; 864 865 fp = getf(uap->fd); 866 if (fp == NULL) 867 return; 868 if (fp->f_type == DTYPE_SOCKET) { 869 u.u_error = EINVAL; 870 return; 871 } 872 ip = fp->f_inode; 873 ilock(ip); 874 syncip(ip); 875 iunlock(ip); 876 } 877 878 /* 879 * Rename system call. 880 * rename("foo", "bar"); 881 * is essentially 882 * unlink("bar"); 883 * link("foo", "bar"); 884 * unlink("foo"); 885 * but ``atomically''. Can't do full commit without saving state in the 886 * inode on disk which isn't feasible at this time. Best we can do is 887 * always guarantee the target exists. 888 * 889 * Basic algorithm is: 890 * 891 * 1) Bump link count on source while we're linking it to the 892 * target. This also insure the inode won't be deleted out 893 * from underneath us while we work. 894 * 2) Link source to destination. If destination already exists, 895 * delete it first. 896 * 3) Unlink source reference to inode if still around. 897 * 4) If a directory was moved and the parent of the destination 898 * is different from the source, patch the ".." entry in the 899 * directory. 900 * 901 * Source and destination must either both be directories, or both 902 * not be directories. If target is a directory, it must be empty. 903 */ 904 rename() 905 { 906 struct a { 907 char *from; 908 char *to; 909 } *uap; 910 register struct inode *ip, *xp, *dp; 911 int oldparent, parentdifferent, doingdirectory; 912 int error = 0; 913 914 uap = (struct a *)u.u_ap; 915 ip = namei(uchar, LOOKUP | LOCKPARENT, 0); 916 if (ip == NULL) 917 return; 918 dp = u.u_pdir; 919 oldparent = 0, doingdirectory = 0; 920 if ((ip->i_mode&IFMT) == IFDIR) { 921 register struct direct *d; 922 923 d = &u.u_dent; 924 /* 925 * Avoid "." and ".." for obvious reasons. 926 */ 927 if (d->d_name[0] == '.') { 928 if (d->d_namlen == 1 || 929 (d->d_namlen == 2 && d->d_name[1] == '.')) { 930 iput(ip); 931 u.u_error = EINVAL; 932 return; 933 } 934 } 935 oldparent = dp->i_number; 936 doingdirectory++; 937 } 938 irele(dp); 939 940 /* 941 * 1) Bump link count while we're moving stuff 942 * around. If we crash somewhere before 943 * completing our work, the link count 944 * may be wrong, but correctable. 945 */ 946 ip->i_nlink++; 947 ip->i_flag |= ICHG; 948 iupdat(ip, &time, &time, 1); 949 iunlock(ip); 950 951 /* 952 * When the target exists, both the directory 953 * and target inodes are returned locked. 954 */ 955 u.u_dirp = (caddr_t)uap->to; 956 xp = namei(uchar, CREATE | LOCKPARENT, 0); 957 if (u.u_error) { 958 error = u.u_error; 959 goto out; 960 } 961 dp = u.u_pdir; 962 /* 963 * 2) If target doesn't exist, link the target 964 * to the source and unlink the source. 965 * Otherwise, rewrite the target directory 966 * entry to reference the source inode and 967 * expunge the original entry's existence. 968 */ 969 parentdifferent = oldparent != dp->i_number; 970 if (xp == NULL) { 971 if (dp->i_dev != ip->i_dev) { 972 error = EXDEV; 973 goto bad; 974 } 975 /* 976 * Account for ".." in directory. 977 * When source and destination have the 978 * same parent we don't fool with the 979 * link count -- this isn't required 980 * because we do a similar check below. 981 */ 982 if (doingdirectory && parentdifferent) { 983 dp->i_nlink++; 984 dp->i_flag |= ICHG; 985 iupdat(dp, &time, &time, 1); 986 } 987 direnter(ip); 988 if (u.u_error) { 989 error = u.u_error; 990 goto out; 991 } 992 } else { 993 if (xp->i_dev != dp->i_dev || xp->i_dev != ip->i_dev) { 994 error = EXDEV; 995 goto bad; 996 } 997 /* 998 * Target must be empty if a directory 999 * and have no links to it. 1000 * Also, insure source and target are 1001 * compatible (both directories, or both 1002 * not directories). 1003 */ 1004 if ((xp->i_mode&IFMT) == IFDIR) { 1005 if (!dirempty(xp) || xp->i_nlink > 2) { 1006 error = ENOTEMPTY; 1007 goto bad; 1008 } 1009 if (!doingdirectory) { 1010 error = ENOTDIR; 1011 goto bad; 1012 } 1013 } else if (doingdirectory) { 1014 error = EISDIR; 1015 goto bad; 1016 } 1017 dirrewrite(dp, ip); 1018 if (u.u_error) { 1019 error = u.u_error; 1020 goto bad1; 1021 } 1022 /* 1023 * Adjust the link count of the target to 1024 * reflect the dirrewrite above. If this is 1025 * a directory it is empty and there are 1026 * no links to it, so we can squash the inode and 1027 * any space associated with it. We disallowed 1028 * renaming over top of a directory with links to 1029 * it above, as we've no way to determine if 1030 * we've got a link or the directory itself, and 1031 * if we get a link, then ".." will be screwed up. 1032 */ 1033 xp->i_nlink--; 1034 if (doingdirectory) { 1035 if (--xp->i_nlink != 0) 1036 panic("rename: linked directory"); 1037 itrunc(xp, (u_long)0); 1038 } 1039 xp->i_flag |= ICHG; 1040 iput(xp); 1041 } 1042 1043 /* 1044 * 3) Unlink the source. 1045 */ 1046 u.u_dirp = uap->from; 1047 dp = namei(uchar, DELETE, 0); 1048 /* 1049 * Insure directory entry still exists and 1050 * has not changed since the start of all 1051 * this. If either has occured, forget about 1052 * about deleting the original entry and just 1053 * adjust the link count in the inode. 1054 */ 1055 if (dp == NULL || u.u_dent.d_ino != ip->i_number) { 1056 ip->i_nlink--; 1057 ip->i_flag |= ICHG; 1058 } else { 1059 /* 1060 * If source is a directory, must adjust 1061 * link count of parent directory also. 1062 * If target didn't exist and source and 1063 * target have the same parent, then we 1064 * needn't touch the link count, it all 1065 * balances out in the end. Otherwise, we 1066 * must do so to reflect deletion of ".." 1067 * done above. 1068 */ 1069 if (doingdirectory && (xp != NULL || parentdifferent)) { 1070 dp->i_nlink--; 1071 dp->i_flag |= ICHG; 1072 } 1073 if (dirremove()) { 1074 ip->i_nlink--; 1075 ip->i_flag |= ICHG; 1076 } 1077 if (error == 0) /* conservative */ 1078 error = u.u_error; 1079 } 1080 irele(ip); 1081 if (dp) 1082 iput(dp); 1083 1084 /* 1085 * 4) Renaming a directory with the parent 1086 * different requires ".." to be rewritten. 1087 * The window is still there for ".." to 1088 * be inconsistent, but this is unavoidable, 1089 * and a lot shorter than when it was done 1090 * in a user process. 1091 */ 1092 if (doingdirectory && parentdifferent && error == 0) { 1093 struct dirtemplate dirbuf; 1094 1095 u.u_dirp = uap->to; 1096 ip = namei(uchar, LOOKUP | LOCKPARENT, 0); 1097 if (ip == NULL) { 1098 printf("rename: .. went away\n"); 1099 return; 1100 } 1101 dp = u.u_pdir; 1102 if ((ip->i_mode&IFMT) != IFDIR) { 1103 printf("rename: .. not a directory\n"); 1104 goto stuck; 1105 } 1106 error = rdwri(UIO_READ, ip, (caddr_t)&dirbuf, 1107 sizeof (struct dirtemplate), (off_t)0, 1, (int *)0); 1108 if (error == 0) { 1109 dirbuf.dotdot_ino = dp->i_number; 1110 (void) rdwri(UIO_WRITE, ip, (caddr_t)&dirbuf, 1111 sizeof (struct dirtemplate), (off_t)0, 1, (int *)0); 1112 } 1113 stuck: 1114 irele(dp); 1115 iput(ip); 1116 } 1117 goto done; 1118 1119 bad: 1120 iput(u.u_pdir); 1121 bad1: 1122 if (xp) 1123 irele(xp); 1124 out: 1125 ip->i_nlink--; 1126 ip->i_flag |= ICHG; 1127 irele(ip); 1128 done: 1129 if (error) 1130 u.u_error = error; 1131 } 1132 1133 /* 1134 * Make a new file. 1135 */ 1136 struct inode * 1137 maknode(mode) 1138 int mode; 1139 { 1140 register struct inode *ip; 1141 ino_t ipref; 1142 1143 if ((mode & IFMT) == IFDIR) 1144 ipref = dirpref(u.u_pdir->i_fs); 1145 else 1146 ipref = u.u_pdir->i_number; 1147 ip = ialloc(u.u_pdir, ipref, mode); 1148 if (ip == NULL) { 1149 iput(u.u_pdir); 1150 return (NULL); 1151 } 1152 #ifdef QUOTA 1153 if (ip->i_dquot != NODQUOT) 1154 panic("maknode: dquot"); 1155 #endif 1156 ip->i_flag |= IACC|IUPD|ICHG; 1157 if ((mode & IFMT) == 0) 1158 mode |= IFREG; 1159 ip->i_mode = mode & ~u.u_cmask; 1160 ip->i_nlink = 1; 1161 ip->i_uid = u.u_uid; 1162 ip->i_gid = u.u_pdir->i_gid; 1163 #ifdef QUOTA 1164 ip->i_dquot = inoquota(ip); 1165 #endif 1166 1167 /* 1168 * Make sure inode goes to disk before directory entry. 1169 */ 1170 iupdat(ip, &time, &time, 1); 1171 direnter(ip); 1172 if (u.u_error) { 1173 /* 1174 * write error occurred trying to update directory 1175 * so must deallocate the inode 1176 */ 1177 ip->i_nlink = 0; 1178 ip->i_flag |= ICHG; 1179 iput(ip); 1180 return (NULL); 1181 } 1182 return (ip); 1183 } 1184