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 are permitted 6 * provided that the above copyright notice and this paragraph are 7 * duplicated in all such forms and that any documentation, 8 * advertising materials, and other materials related to such 9 * distribution and use acknowledge that the software was developed 10 * by the University of California, Berkeley. The name of the 11 * University may not be used to endorse or promote products derived 12 * from this software without specific prior written permission. 13 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 14 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 15 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. 16 * 17 * @(#)vfs_vnops.c 7.4 (Berkeley) 05/09/89 18 */ 19 20 #include "param.h" 21 #include "systm.h" 22 #include "user.h" 23 #include "kernel.h" 24 #include "file.h" 25 #include "stat.h" 26 #include "buf.h" 27 #include "proc.h" 28 #include "uio.h" 29 #include "socket.h" 30 #include "socketvar.h" 31 #include "mount.h" 32 #include "vnode.h" 33 #include "../ufs/inode.h" 34 #include "../ufs/fs.h" 35 #include "../ufs/quota.h" 36 #include "ioctl.h" 37 #include "tty.h" 38 39 int vn_read(), vn_write(), vn_ioctl(), vn_select(), vn_close(); 40 struct fileops vnops = 41 { vn_read, vn_write, vn_ioctl, vn_select, vn_close }; 42 43 /* 44 * Common code for vnode open operations. 45 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine. 46 */ 47 vn_open(ndp, fmode, cmode) 48 register struct nameidata *ndp; 49 int fmode, cmode; 50 { 51 register struct vnode *vp; 52 struct vattr vat; 53 struct vattr *vap = &vat; 54 int error; 55 56 if (fmode & FCREAT) { 57 ndp->ni_nameiop = CREATE | LOCKPARENT | LOCKLEAF; 58 if ((fmode & FEXCL) == 0) 59 ndp->ni_nameiop |= FOLLOW; 60 if (error = namei(ndp)) 61 return (error); 62 if (ndp->ni_vp == NULL) { 63 vattr_null(vap); 64 vap->va_type = VREG; 65 vap->va_mode = cmode; 66 if (error = VOP_CREATE(ndp, vap)) 67 return (error); 68 fmode &= ~FTRUNC; 69 vp = ndp->ni_vp; 70 } else { 71 vp = ndp->ni_vp; 72 ndp->ni_vp = 0; 73 VOP_ABORTOP(ndp); 74 ndp->ni_vp = vp; 75 if (fmode & FEXCL) { 76 error = EEXIST; 77 goto bad; 78 } 79 fmode &= ~FCREAT; 80 } 81 } else { 82 ndp->ni_nameiop = LOOKUP | FOLLOW | LOCKLEAF; 83 if (error = namei(ndp)) 84 return (error); 85 vp = ndp->ni_vp; 86 } 87 if (vp->v_type == VSOCK) { 88 error = EOPNOTSUPP; 89 goto bad; 90 } 91 if ((fmode & FCREAT) == 0) { 92 if (fmode & FREAD) { 93 if (error = vn_access(vp, VREAD, ndp->ni_cred)) 94 goto bad; 95 } 96 if (fmode & (FWRITE|FTRUNC)) { 97 if (error = vn_access(vp, VWRITE, ndp->ni_cred)) 98 goto bad; 99 if (vp->v_type == VDIR) { 100 error = EISDIR; 101 goto bad; 102 } 103 } 104 } 105 if (fmode & FTRUNC) { 106 vattr_null(vap); 107 vap->va_size = 0; 108 if (error = VOP_SETATTR(vp, vap, ndp->ni_cred)) 109 goto bad; 110 } 111 VOP_UNLOCK(vp); 112 if (setjmp(&u.u_qsave)) { 113 if (error == 0) 114 error = EINTR; 115 return (error); 116 } 117 return (VOP_OPEN(vp, fmode, ndp->ni_cred)); 118 119 bad: 120 vput(vp); 121 return(error); 122 } 123 124 /* 125 * Check mode permission on vnode pointer. Mode is READ, WRITE or EXEC. 126 * In the case of WRITE, the read-only status of the file system is 127 * checked. Also in WRITE, prototype text segments cannot be written. 128 */ 129 vn_access(vp, mode, cred) 130 register struct vnode *vp; 131 int mode; 132 struct ucred *cred; 133 { 134 135 if (mode & VWRITE) { 136 /* 137 * Disallow write attempts on read-only file systems; 138 * unless the file is a socket or a block or character 139 * device resident on the file system. 140 */ 141 if ((vp->v_mount->m_flag & M_RDONLY) && 142 vp->v_type != VCHR && 143 vp->v_type != VBLK && 144 vp->v_type != VSOCK) 145 return (EROFS); 146 /* 147 * If there's shared text associated with 148 * the inode, try to free it up once. If 149 * we fail, we can't allow writing. 150 */ 151 if (vp->v_flag & VTEXT) 152 xrele(vp); 153 if (vp->v_flag & VTEXT) 154 return (ETXTBSY); 155 } 156 return (VOP_ACCESS(vp, mode, cred)); 157 } 158 159 /* 160 * Vnode version of rdwri() for calls on file systems. 161 */ 162 vn_rdwr(rw, vp, base, len, offset, segflg, ioflg, cred, aresid) 163 enum uio_rw rw; 164 struct vnode *vp; 165 caddr_t base; 166 int len; 167 off_t offset; 168 enum uio_seg segflg; 169 int ioflg; 170 struct ucred *cred; 171 int *aresid; 172 { 173 struct uio auio; 174 struct iovec aiov; 175 int error; 176 177 auio.uio_iov = &aiov; 178 auio.uio_iovcnt = 1; 179 aiov.iov_base = base; 180 aiov.iov_len = len; 181 auio.uio_resid = len; 182 auio.uio_offset = offset; 183 auio.uio_segflg = segflg; 184 auio.uio_rw = rw; 185 if (rw == UIO_READ) 186 error = VOP_READ(vp, &auio, &offset, ioflg, cred); 187 else 188 error = VOP_WRITE(vp, &auio, &offset, ioflg, cred); 189 if (aresid) 190 *aresid = auio.uio_resid; 191 else 192 if (auio.uio_resid && error == 0) 193 error = EIO; 194 return (error); 195 } 196 197 vn_read(fp, uio, cred) 198 struct file *fp; 199 struct uio *uio; 200 struct ucred *cred; 201 { 202 203 return (VOP_READ((struct vnode *)fp->f_data, uio, &(fp->f_offset), 204 (fp->f_flag & FNDELAY) ? IO_NDELAY : 0, cred)); 205 } 206 207 vn_write(fp, uio, cred) 208 struct file *fp; 209 struct uio *uio; 210 struct ucred *cred; 211 { 212 register struct vnode *vp = (struct vnode *)fp->f_data; 213 int ioflag = 0; 214 215 if (vp->v_type == VREG && (fp->f_flag & FAPPEND)) 216 ioflag |= IO_APPEND; 217 if (fp->f_flag & FNDELAY) 218 ioflag |= IO_NDELAY; 219 return (VOP_WRITE(vp, uio, &(fp->f_offset), ioflag, cred)); 220 } 221 222 /* 223 * Get stat info for a vnode. 224 */ 225 vn_stat(vp, sb) 226 struct vnode *vp; 227 register struct stat *sb; 228 { 229 struct vattr vattr; 230 register struct vattr *vap; 231 int error; 232 u_short mode; 233 234 vap = &vattr; 235 error = VOP_GETATTR(vp, vap, u.u_cred); 236 if (error) 237 return (error); 238 /* 239 * Copy from vattr table 240 */ 241 sb->st_dev = vap->va_fsid; 242 sb->st_ino = vap->va_fileid; 243 mode = vap->va_mode; 244 switch (vp->v_type) { 245 case VREG: 246 mode |= IFREG; 247 break; 248 case VDIR: 249 mode |= IFDIR; 250 break; 251 case VBLK: 252 mode |= IFBLK; 253 break; 254 case VCHR: 255 mode |= IFCHR; 256 break; 257 case VLNK: 258 mode |= IFLNK; 259 break; 260 case VSOCK: 261 mode |= IFSOCK; 262 break; 263 default: 264 return (EBADF); 265 }; 266 sb->st_mode = mode; 267 sb->st_nlink = vap->va_nlink; 268 sb->st_uid = vap->va_uid; 269 sb->st_gid = vap->va_gid; 270 sb->st_rdev = vap->va_rdev; 271 sb->st_size = vap->va_size; 272 sb->st_atime = vap->va_atime.tv_sec; 273 sb->st_spare1 = 0; 274 sb->st_mtime = vap->va_mtime.tv_sec; 275 sb->st_spare2 = 0; 276 sb->st_ctime = vap->va_ctime.tv_sec; 277 sb->st_spare3 = 0; 278 sb->st_blksize = vap->va_blocksize; 279 sb->st_spare4[0] = sb->st_spare4[1] = 0; 280 /* 281 * XXX THIS IS NOT CORRECT!!, but be sure to change ufs_getattr() 282 * if you change it. 283 */ 284 sb->st_blocks = vap->va_bytes; 285 return (0); 286 } 287 288 /* 289 * Vnode ioctl call 290 */ 291 vn_ioctl(fp, com, data) 292 struct file *fp; 293 int com; 294 caddr_t data; 295 { 296 register struct vnode *vp = ((struct vnode *)fp->f_data); 297 struct vattr vattr; 298 int error; 299 300 switch (vp->v_type) { 301 302 case VREG: 303 case VDIR: 304 if (com == FIONREAD) { 305 if (error = VOP_GETATTR(vp, &vattr, u.u_cred)) 306 return (error); 307 *(off_t *)data = vattr.va_size - fp->f_offset; 308 return (0); 309 } 310 if (com == FIONBIO || com == FIOASYNC) /* XXX */ 311 return (0); /* XXX */ 312 /* fall into ... */ 313 314 default: 315 return (ENOTTY); 316 317 case VCHR: 318 case VBLK: 319 u.u_r.r_val1 = 0; 320 if (setjmp(&u.u_qsave)) { 321 if ((u.u_sigintr & sigmask(u.u_procp->p_cursig)) != 0) 322 return(EINTR); 323 u.u_eosys = RESTARTSYS; 324 return (0); 325 } 326 return (VOP_IOCTL(vp, com, data, fp->f_flag, u.u_cred)); 327 } 328 } 329 330 /* 331 * Vnode select call 332 */ 333 vn_select(fp, which) 334 struct file *fp; 335 int which; 336 { 337 return(VOP_SELECT(((struct vnode *)fp->f_data), which, u.u_cred)); 338 } 339 340 /* 341 * Vnode close call 342 */ 343 vn_close(fp) 344 register struct file *fp; 345 { 346 struct vnode *vp = ((struct vnode *)fp->f_data); 347 int error; 348 349 if (fp->f_flag & (FSHLOCK|FEXLOCK)) 350 vn_unlock(fp, FSHLOCK|FEXLOCK); 351 /* 352 * Must delete vnode reference from this file entry 353 * before VOP_CLOSE, so that only other references 354 * will prevent close. 355 */ 356 fp->f_data = (caddr_t) 0; 357 error = VOP_CLOSE(vp, fp->f_flag, u.u_cred); 358 vrele(vp); 359 return (error); 360 } 361 362 /* 363 * Place an advisory lock on a vnode. 364 * !! THIS IMPLIES THAT ALL STATEFUL FILE SERVERS WILL USE file table entries 365 */ 366 vn_lock(fp, cmd) 367 register struct file *fp; 368 int cmd; 369 { 370 register int priority = PLOCK; 371 register struct vnode *vp = (struct vnode *)fp->f_data; 372 373 if ((cmd & LOCK_EX) == 0) 374 priority += 4; 375 if (setjmp(&u.u_qsave)) { 376 if ((u.u_sigintr & sigmask(u.u_procp->p_cursig)) != 0) 377 return(EINTR); 378 u.u_eosys = RESTARTSYS; 379 return (0); 380 } 381 /* 382 * If there's a exclusive lock currently applied 383 * to the file, then we've gotta wait for the 384 * lock with everyone else. 385 */ 386 again: 387 while (vp->v_flag & VEXLOCK) { 388 /* 389 * If we're holding an exclusive 390 * lock, then release it. 391 */ 392 if (fp->f_flag & FEXLOCK) { 393 vn_unlock(fp, FEXLOCK); 394 continue; 395 } 396 if (cmd & LOCK_NB) 397 return (EWOULDBLOCK); 398 vp->v_flag |= VLWAIT; 399 sleep((caddr_t)&vp->v_exlockc, priority); 400 } 401 if ((cmd & LOCK_EX) && (vp->v_flag & VSHLOCK)) { 402 /* 403 * Must wait for any shared locks to finish 404 * before we try to apply a exclusive lock. 405 * 406 * If we're holding a shared 407 * lock, then release it. 408 */ 409 if (fp->f_flag & FSHLOCK) { 410 vn_unlock(fp, FSHLOCK); 411 goto again; 412 } 413 if (cmd & LOCK_NB) 414 return (EWOULDBLOCK); 415 vp->v_flag |= VLWAIT; 416 sleep((caddr_t)&vp->v_shlockc, PLOCK); 417 goto again; 418 } 419 if (fp->f_flag & FEXLOCK) 420 panic("vn_lock"); 421 if (cmd & LOCK_EX) { 422 cmd &= ~LOCK_SH; 423 vp->v_exlockc++; 424 vp->v_flag |= VEXLOCK; 425 fp->f_flag |= FEXLOCK; 426 } 427 if ((cmd & LOCK_SH) && (fp->f_flag & FSHLOCK) == 0) { 428 vp->v_shlockc++; 429 vp->v_flag |= VSHLOCK; 430 fp->f_flag |= FSHLOCK; 431 } 432 return (0); 433 } 434 435 /* 436 * Unlock a file. 437 */ 438 vn_unlock(fp, kind) 439 register struct file *fp; 440 int kind; 441 { 442 register struct vnode *vp = (struct vnode *)fp->f_data; 443 int flags; 444 445 kind &= fp->f_flag; 446 if (vp == NULL || kind == 0) 447 return; 448 flags = vp->v_flag; 449 if (kind & FSHLOCK) { 450 if ((flags & VSHLOCK) == 0) 451 panic("vn_unlock: SHLOCK"); 452 if (--vp->v_shlockc == 0) { 453 vp->v_flag &= ~VSHLOCK; 454 if (flags & VLWAIT) 455 wakeup((caddr_t)&vp->v_shlockc); 456 } 457 fp->f_flag &= ~FSHLOCK; 458 } 459 if (kind & FEXLOCK) { 460 if ((flags & VEXLOCK) == 0) 461 panic("vn_unlock: EXLOCK"); 462 if (--vp->v_exlockc == 0) { 463 vp->v_flag &= ~(VEXLOCK|VLWAIT); 464 if (flags & VLWAIT) 465 wakeup((caddr_t)&vp->v_exlockc); 466 } 467 fp->f_flag &= ~FEXLOCK; 468 } 469 } 470 471 /* 472 * vn_fhtovp() - convert a fh to a vnode ptr (optionally locked) 473 * - look up fsid in mount list (if not found ret error) 474 * - get vp by calling VFS_FHTOVP() macro 475 * - if lockflag lock it with VOP_LOCK() 476 */ 477 vn_fhtovp(fhp, lockflag, vpp) 478 fhandle_t *fhp; 479 int lockflag; 480 struct vnode **vpp; 481 { 482 register struct mount *mp; 483 int error; 484 485 if ((mp = getvfs(&fhp->fh_fsid)) == NULL) 486 return (ESTALE); 487 if (error = VFS_FHTOVP(mp, &fhp->fh_fid, vpp)) 488 return (error); 489 if (lockflag) 490 VOP_LOCK(*vpp); 491 return (0); 492 } 493 494 /* 495 * Revoke access the current tty by all processes. 496 * Used only by the super-user in init 497 * to give ``clean'' terminals at login. 498 */ 499 vhangup() 500 { 501 502 if (u.u_error = suser(u.u_cred, &u.u_acflag)) 503 return; 504 if (u.u_ttyp == NULL) 505 return; 506 forceclose(u.u_ttyd); 507 if ((u.u_ttyp->t_state) & TS_ISOPEN) 508 gsignal(u.u_ttyp->t_pgid, SIGHUP); 509 u.u_ttyp->t_session = 0; 510 u.u_ttyp->t_pgid = 0; 511 } 512 513 forceclose(dev) 514 dev_t dev; 515 { 516 register struct file *fp; 517 register struct vnode *vp; 518 519 for (fp = file; fp < fileNFILE; fp++) { 520 if (fp->f_count == 0) 521 continue; 522 if (fp->f_type != DTYPE_VNODE) 523 continue; 524 vp = (struct vnode *)fp->f_data; 525 if (vp == 0) 526 continue; 527 if (vp->v_type != VCHR) 528 continue; 529 if (vp->v_rdev != dev) 530 continue; 531 fp->f_flag &= ~(FREAD|FWRITE); 532 } 533 } 534 535 /* 536 * Vnode release, just decrement the count and call VOP_INACTIVE() 537 */ 538 void vrele(vp) 539 register struct vnode *vp; 540 { 541 542 if (vp == NULL) 543 return; 544 vp->v_count--; 545 if (vp->v_count < 0) 546 printf("inode %d, bad ref count %d\n", 547 VTOI(vp)->i_number, vp->v_count); 548 if (vp->v_count == 0) 549 VOP_INACTIVE(vp); 550 } 551 552 /* 553 * vput(), just unlock and vrele() 554 */ 555 vput(vp) 556 register struct vnode *vp; 557 { 558 VOP_UNLOCK(vp); 559 vrele(vp); 560 } 561 562 /* 563 * Noop 564 */ 565 vfs_noop() 566 { 567 568 return (ENXIO); 569 } 570 571 /* 572 * Null op 573 */ 574 vfs_nullop() 575 { 576 577 return (0); 578 } 579