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FreeBSD/Linux Kernel Cross Reference
sys/kern/vfs_vnops.c
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1 /* 2 * Copyright (c) 1982, 1986, 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * @(#)vfs_vnops.c 8.2 (Berkeley) 1/21/94 39 * $FreeBSD: releng/5.1/sys/kern/vfs_vnops.c 114216 2003-04-29 13:36:06Z kan $ 40 */ 41 42 #include "opt_mac.h" 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/fcntl.h> 47 #include <sys/file.h> 48 #include <sys/stat.h> 49 #include <sys/proc.h> 50 #include <sys/limits.h> 51 #include <sys/lock.h> 52 #include <sys/mac.h> 53 #include <sys/mount.h> 54 #include <sys/mutex.h> 55 #include <sys/namei.h> 56 #include <sys/vnode.h> 57 #include <sys/bio.h> 58 #include <sys/buf.h> 59 #include <sys/filio.h> 60 #include <sys/sx.h> 61 #include <sys/ttycom.h> 62 #include <sys/conf.h> 63 #include <sys/syslog.h> 64 65 static fo_rdwr_t vn_read; 66 static fo_rdwr_t vn_write; 67 static fo_ioctl_t vn_ioctl; 68 static fo_poll_t vn_poll; 69 static fo_kqfilter_t vn_kqfilter; 70 static fo_stat_t vn_statfile; 71 static fo_close_t vn_closefile; 72 73 struct fileops vnops = { 74 vn_read, vn_write, vn_ioctl, vn_poll, vn_kqfilter, 75 vn_statfile, vn_closefile, DFLAG_PASSABLE 76 }; 77 78 int 79 vn_open(ndp, flagp, cmode) 80 register struct nameidata *ndp; 81 int *flagp, cmode; 82 { 83 struct thread *td = ndp->ni_cnd.cn_thread; 84 85 return (vn_open_cred(ndp, flagp, cmode, td->td_ucred)); 86 } 87 88 /* 89 * Common code for vnode open operations. 90 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine. 91 * 92 * Note that this does NOT free nameidata for the successful case, 93 * due to the NDINIT being done elsewhere. 94 */ 95 int 96 vn_open_cred(ndp, flagp, cmode, cred) 97 register struct nameidata *ndp; 98 int *flagp, cmode; 99 struct ucred *cred; 100 { 101 struct vnode *vp; 102 struct mount *mp; 103 struct thread *td = ndp->ni_cnd.cn_thread; 104 struct vattr vat; 105 struct vattr *vap = &vat; 106 int mode, fmode, error; 107 #ifdef LOOKUP_SHARED 108 int exclusive; /* The current intended lock state */ 109 110 exclusive = 0; 111 #endif 112 113 restart: 114 fmode = *flagp; 115 if (fmode & O_CREAT) { 116 ndp->ni_cnd.cn_nameiop = CREATE; 117 ndp->ni_cnd.cn_flags = LOCKPARENT | LOCKLEAF; 118 if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0) 119 ndp->ni_cnd.cn_flags |= FOLLOW; 120 bwillwrite(); 121 if ((error = namei(ndp)) != 0) 122 return (error); 123 if (ndp->ni_vp == NULL) { 124 VATTR_NULL(vap); 125 vap->va_type = VREG; 126 vap->va_mode = cmode; 127 if (fmode & O_EXCL) 128 vap->va_vaflags |= VA_EXCLUSIVE; 129 if (vn_start_write(ndp->ni_dvp, &mp, V_NOWAIT) != 0) { 130 NDFREE(ndp, NDF_ONLY_PNBUF); 131 vput(ndp->ni_dvp); 132 if ((error = vn_start_write(NULL, &mp, 133 V_XSLEEP | PCATCH)) != 0) 134 return (error); 135 goto restart; 136 } 137 #ifdef MAC 138 error = mac_check_vnode_create(cred, ndp->ni_dvp, 139 &ndp->ni_cnd, vap); 140 if (error == 0) { 141 #endif 142 VOP_LEASE(ndp->ni_dvp, td, cred, LEASE_WRITE); 143 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp, 144 &ndp->ni_cnd, vap); 145 #ifdef MAC 146 } 147 #endif 148 vput(ndp->ni_dvp); 149 vn_finished_write(mp); 150 if (error) { 151 NDFREE(ndp, NDF_ONLY_PNBUF); 152 return (error); 153 } 154 ASSERT_VOP_UNLOCKED(ndp->ni_dvp, "create"); 155 ASSERT_VOP_LOCKED(ndp->ni_vp, "create"); 156 fmode &= ~O_TRUNC; 157 vp = ndp->ni_vp; 158 #ifdef LOOKUP_SHARED 159 exclusive = 1; 160 #endif 161 } else { 162 if (ndp->ni_dvp == ndp->ni_vp) 163 vrele(ndp->ni_dvp); 164 else 165 vput(ndp->ni_dvp); 166 ndp->ni_dvp = NULL; 167 vp = ndp->ni_vp; 168 if (fmode & O_EXCL) { 169 error = EEXIST; 170 goto bad; 171 } 172 fmode &= ~O_CREAT; 173 } 174 } else { 175 ndp->ni_cnd.cn_nameiop = LOOKUP; 176 #ifdef LOOKUP_SHARED 177 ndp->ni_cnd.cn_flags = 178 ((fmode & O_NOFOLLOW) ? NOFOLLOW : FOLLOW) | 179 LOCKSHARED | LOCKLEAF; 180 #else 181 ndp->ni_cnd.cn_flags = 182 ((fmode & O_NOFOLLOW) ? NOFOLLOW : FOLLOW) | LOCKLEAF; 183 #endif 184 if ((error = namei(ndp)) != 0) 185 return (error); 186 vp = ndp->ni_vp; 187 } 188 if (vp->v_type == VLNK) { 189 error = EMLINK; 190 goto bad; 191 } 192 if (vp->v_type == VSOCK) { 193 error = EOPNOTSUPP; 194 goto bad; 195 } 196 mode = 0; 197 if (fmode & (FWRITE | O_TRUNC)) { 198 if (vp->v_type == VDIR) { 199 error = EISDIR; 200 goto bad; 201 } 202 mode |= VWRITE; 203 } 204 if (fmode & FREAD) 205 mode |= VREAD; 206 if (fmode & O_APPEND) 207 mode |= VAPPEND; 208 #ifdef MAC 209 error = mac_check_vnode_open(cred, vp, mode); 210 if (error) 211 goto bad; 212 #endif 213 if ((fmode & O_CREAT) == 0) { 214 if (mode & VWRITE) { 215 error = vn_writechk(vp); 216 if (error) 217 goto bad; 218 } 219 if (mode) { 220 error = VOP_ACCESS(vp, mode, cred, td); 221 if (error) 222 goto bad; 223 } 224 } 225 if ((error = VOP_GETATTR(vp, vap, cred, td)) == 0) { 226 vp->v_cachedfs = vap->va_fsid; 227 vp->v_cachedid = vap->va_fileid; 228 } 229 if ((error = VOP_OPEN(vp, fmode, cred, td)) != 0) 230 goto bad; 231 /* 232 * Make sure that a VM object is created for VMIO support. 233 */ 234 if (vn_canvmio(vp) == TRUE) { 235 #ifdef LOOKUP_SHARED 236 int flock; 237 238 if (!exclusive && VOP_GETVOBJECT(vp, NULL) != 0) 239 VOP_LOCK(vp, LK_UPGRADE, td); 240 /* 241 * In cases where the object is marked as dead object_create 242 * will unlock and relock exclusive. It is safe to call in 243 * here with a shared lock because we only examine fields that 244 * the shared lock guarantees will be stable. In the UPGRADE 245 * case it is not likely that anyone has used this vnode yet 246 * so there will be no contention. The logic after this call 247 * restores the requested locking state. 248 */ 249 #endif 250 if ((error = vfs_object_create(vp, td, cred)) != 0) { 251 VOP_UNLOCK(vp, 0, td); 252 VOP_CLOSE(vp, fmode, cred, td); 253 NDFREE(ndp, NDF_ONLY_PNBUF); 254 vrele(vp); 255 *flagp = fmode; 256 return (error); 257 } 258 #ifdef LOOKUP_SHARED 259 flock = VOP_ISLOCKED(vp, td); 260 if (!exclusive && flock == LK_EXCLUSIVE) 261 VOP_LOCK(vp, LK_DOWNGRADE, td); 262 #endif 263 } 264 265 if (fmode & FWRITE) 266 vp->v_writecount++; 267 *flagp = fmode; 268 return (0); 269 bad: 270 NDFREE(ndp, NDF_ONLY_PNBUF); 271 vput(vp); 272 *flagp = fmode; 273 ndp->ni_vp = NULL; 274 return (error); 275 } 276 277 /* 278 * Check for write permissions on the specified vnode. 279 * Prototype text segments cannot be written. 280 */ 281 int 282 vn_writechk(vp) 283 register struct vnode *vp; 284 { 285 286 ASSERT_VOP_LOCKED(vp, "vn_writechk"); 287 /* 288 * If there's shared text associated with 289 * the vnode, try to free it up once. If 290 * we fail, we can't allow writing. 291 */ 292 if (vp->v_vflag & VV_TEXT) 293 return (ETXTBSY); 294 295 return (0); 296 } 297 298 /* 299 * Vnode close call 300 */ 301 int 302 vn_close(vp, flags, file_cred, td) 303 register struct vnode *vp; 304 int flags; 305 struct ucred *file_cred; 306 struct thread *td; 307 { 308 int error; 309 310 if (flags & FWRITE) 311 vp->v_writecount--; 312 error = VOP_CLOSE(vp, flags, file_cred, td); 313 /* 314 * XXX - In certain instances VOP_CLOSE has to do the vrele 315 * itself. If the vrele has been done, it will return EAGAIN 316 * to indicate that the vrele should not be done again. When 317 * this happens, we just return success. The correct thing to 318 * do would be to have all VOP_CLOSE instances do the vrele. 319 */ 320 if (error == EAGAIN) 321 return (0); 322 vrele(vp); 323 return (error); 324 } 325 326 /* 327 * Sequential heuristic - detect sequential operation 328 */ 329 static __inline 330 int 331 sequential_heuristic(struct uio *uio, struct file *fp) 332 { 333 334 if ((uio->uio_offset == 0 && fp->f_seqcount > 0) || 335 uio->uio_offset == fp->f_nextoff) { 336 /* 337 * XXX we assume that the filesystem block size is 338 * the default. Not true, but still gives us a pretty 339 * good indicator of how sequential the read operations 340 * are. 341 */ 342 fp->f_seqcount += (uio->uio_resid + BKVASIZE - 1) / BKVASIZE; 343 if (fp->f_seqcount > IO_SEQMAX) 344 fp->f_seqcount = IO_SEQMAX; 345 return(fp->f_seqcount << IO_SEQSHIFT); 346 } 347 348 /* 349 * Not sequential, quick draw-down of seqcount 350 */ 351 if (fp->f_seqcount > 1) 352 fp->f_seqcount = 1; 353 else 354 fp->f_seqcount = 0; 355 return(0); 356 } 357 358 /* 359 * Package up an I/O request on a vnode into a uio and do it. 360 */ 361 int 362 vn_rdwr(rw, vp, base, len, offset, segflg, ioflg, active_cred, file_cred, 363 aresid, td) 364 enum uio_rw rw; 365 struct vnode *vp; 366 caddr_t base; 367 int len; 368 off_t offset; 369 enum uio_seg segflg; 370 int ioflg; 371 struct ucred *active_cred; 372 struct ucred *file_cred; 373 int *aresid; 374 struct thread *td; 375 { 376 struct uio auio; 377 struct iovec aiov; 378 struct mount *mp; 379 struct ucred *cred; 380 int error; 381 382 if ((ioflg & IO_NODELOCKED) == 0) { 383 mp = NULL; 384 if (rw == UIO_WRITE) { 385 if (vp->v_type != VCHR && 386 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) 387 != 0) 388 return (error); 389 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 390 } else { 391 /* 392 * XXX This should be LK_SHARED but I don't trust VFS 393 * enough to leave it like that until it has been 394 * reviewed further. 395 */ 396 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 397 } 398 399 } 400 auio.uio_iov = &aiov; 401 auio.uio_iovcnt = 1; 402 aiov.iov_base = base; 403 aiov.iov_len = len; 404 auio.uio_resid = len; 405 auio.uio_offset = offset; 406 auio.uio_segflg = segflg; 407 auio.uio_rw = rw; 408 auio.uio_td = td; 409 error = 0; 410 #ifdef MAC 411 if ((ioflg & IO_NOMACCHECK) == 0) { 412 if (rw == UIO_READ) 413 error = mac_check_vnode_read(active_cred, file_cred, 414 vp); 415 else 416 error = mac_check_vnode_write(active_cred, file_cred, 417 vp); 418 } 419 #endif 420 if (error == 0) { 421 if (file_cred) 422 cred = file_cred; 423 else 424 cred = active_cred; 425 if (rw == UIO_READ) 426 error = VOP_READ(vp, &auio, ioflg, cred); 427 else 428 error = VOP_WRITE(vp, &auio, ioflg, cred); 429 } 430 if (aresid) 431 *aresid = auio.uio_resid; 432 else 433 if (auio.uio_resid && error == 0) 434 error = EIO; 435 if ((ioflg & IO_NODELOCKED) == 0) { 436 if (rw == UIO_WRITE) 437 vn_finished_write(mp); 438 VOP_UNLOCK(vp, 0, td); 439 } 440 return (error); 441 } 442 443 /* 444 * Package up an I/O request on a vnode into a uio and do it. The I/O 445 * request is split up into smaller chunks and we try to avoid saturating 446 * the buffer cache while potentially holding a vnode locked, so we 447 * check bwillwrite() before calling vn_rdwr(). We also call uio_yield() 448 * to give other processes a chance to lock the vnode (either other processes 449 * core'ing the same binary, or unrelated processes scanning the directory). 450 */ 451 int 452 vn_rdwr_inchunks(rw, vp, base, len, offset, segflg, ioflg, active_cred, 453 file_cred, aresid, td) 454 enum uio_rw rw; 455 struct vnode *vp; 456 caddr_t base; 457 int len; 458 off_t offset; 459 enum uio_seg segflg; 460 int ioflg; 461 struct ucred *active_cred; 462 struct ucred *file_cred; 463 int *aresid; 464 struct thread *td; 465 { 466 int error = 0; 467 468 do { 469 int chunk = (len > MAXBSIZE) ? MAXBSIZE : len; 470 471 if (rw != UIO_READ && vp->v_type == VREG) 472 bwillwrite(); 473 error = vn_rdwr(rw, vp, base, chunk, offset, segflg, 474 ioflg, active_cred, file_cred, aresid, td); 475 len -= chunk; /* aresid calc already includes length */ 476 if (error) 477 break; 478 offset += chunk; 479 base += chunk; 480 uio_yield(); 481 } while (len); 482 if (aresid) 483 *aresid += len; 484 return (error); 485 } 486 487 /* 488 * File table vnode read routine. 489 */ 490 static int 491 vn_read(fp, uio, active_cred, flags, td) 492 struct file *fp; 493 struct uio *uio; 494 struct ucred *active_cred; 495 struct thread *td; 496 int flags; 497 { 498 struct vnode *vp; 499 int error, ioflag; 500 501 mtx_lock(&Giant); 502 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", 503 uio->uio_td, td)); 504 vp = fp->f_data; 505 ioflag = 0; 506 if (fp->f_flag & FNONBLOCK) 507 ioflag |= IO_NDELAY; 508 if (fp->f_flag & O_DIRECT) 509 ioflag |= IO_DIRECT; 510 VOP_LEASE(vp, td, fp->f_cred, LEASE_READ); 511 /* 512 * According to McKusick the vn lock is protecting f_offset here. 513 * Once this field has it's own lock we can acquire this shared. 514 */ 515 if ((flags & FOF_OFFSET) == 0) { 516 vn_lock(vp, LK_EXCLUSIVE | LK_NOPAUSE | LK_RETRY, td); 517 uio->uio_offset = fp->f_offset; 518 } else 519 vn_lock(vp, LK_SHARED | LK_NOPAUSE | LK_RETRY, td); 520 521 ioflag |= sequential_heuristic(uio, fp); 522 523 #ifdef MAC 524 error = mac_check_vnode_read(active_cred, fp->f_cred, vp); 525 if (error == 0) 526 #endif 527 error = VOP_READ(vp, uio, ioflag, fp->f_cred); 528 if ((flags & FOF_OFFSET) == 0) 529 fp->f_offset = uio->uio_offset; 530 fp->f_nextoff = uio->uio_offset; 531 VOP_UNLOCK(vp, 0, td); 532 mtx_unlock(&Giant); 533 return (error); 534 } 535 536 /* 537 * File table vnode write routine. 538 */ 539 static int 540 vn_write(fp, uio, active_cred, flags, td) 541 struct file *fp; 542 struct uio *uio; 543 struct ucred *active_cred; 544 struct thread *td; 545 int flags; 546 { 547 struct vnode *vp; 548 struct mount *mp; 549 int error, ioflag; 550 551 mtx_lock(&Giant); 552 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", 553 uio->uio_td, td)); 554 vp = fp->f_data; 555 if (vp->v_type == VREG) 556 bwillwrite(); 557 ioflag = IO_UNIT; 558 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 559 ioflag |= IO_APPEND; 560 if (fp->f_flag & FNONBLOCK) 561 ioflag |= IO_NDELAY; 562 if (fp->f_flag & O_DIRECT) 563 ioflag |= IO_DIRECT; 564 if ((fp->f_flag & O_FSYNC) || 565 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS))) 566 ioflag |= IO_SYNC; 567 mp = NULL; 568 if (vp->v_type != VCHR && 569 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0) { 570 mtx_unlock(&Giant); 571 return (error); 572 } 573 VOP_LEASE(vp, td, fp->f_cred, LEASE_WRITE); 574 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 575 if ((flags & FOF_OFFSET) == 0) 576 uio->uio_offset = fp->f_offset; 577 ioflag |= sequential_heuristic(uio, fp); 578 #ifdef MAC 579 error = mac_check_vnode_write(active_cred, fp->f_cred, vp); 580 if (error == 0) 581 #endif 582 error = VOP_WRITE(vp, uio, ioflag, fp->f_cred); 583 if ((flags & FOF_OFFSET) == 0) 584 fp->f_offset = uio->uio_offset; 585 fp->f_nextoff = uio->uio_offset; 586 VOP_UNLOCK(vp, 0, td); 587 vn_finished_write(mp); 588 mtx_unlock(&Giant); 589 return (error); 590 } 591 592 /* 593 * File table vnode stat routine. 594 */ 595 static int 596 vn_statfile(fp, sb, active_cred, td) 597 struct file *fp; 598 struct stat *sb; 599 struct ucred *active_cred; 600 struct thread *td; 601 { 602 struct vnode *vp = fp->f_data; 603 int error; 604 605 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 606 error = vn_stat(vp, sb, active_cred, fp->f_cred, td); 607 VOP_UNLOCK(vp, 0, td); 608 609 return (error); 610 } 611 612 /* 613 * Stat a vnode; implementation for the stat syscall 614 */ 615 int 616 vn_stat(vp, sb, active_cred, file_cred, td) 617 struct vnode *vp; 618 register struct stat *sb; 619 struct ucred *active_cred; 620 struct ucred *file_cred; 621 struct thread *td; 622 { 623 struct vattr vattr; 624 register struct vattr *vap; 625 int error; 626 u_short mode; 627 628 #ifdef MAC 629 error = mac_check_vnode_stat(active_cred, file_cred, vp); 630 if (error) 631 return (error); 632 #endif 633 634 vap = &vattr; 635 error = VOP_GETATTR(vp, vap, active_cred, td); 636 if (error) 637 return (error); 638 639 vp->v_cachedfs = vap->va_fsid; 640 vp->v_cachedid = vap->va_fileid; 641 642 /* 643 * Zero the spare stat fields 644 */ 645 bzero(sb, sizeof *sb); 646 647 /* 648 * Copy from vattr table 649 */ 650 if (vap->va_fsid != VNOVAL) 651 sb->st_dev = vap->va_fsid; 652 else 653 sb->st_dev = vp->v_mount->mnt_stat.f_fsid.val[0]; 654 sb->st_ino = vap->va_fileid; 655 mode = vap->va_mode; 656 switch (vap->va_type) { 657 case VREG: 658 mode |= S_IFREG; 659 break; 660 case VDIR: 661 mode |= S_IFDIR; 662 break; 663 case VBLK: 664 mode |= S_IFBLK; 665 break; 666 case VCHR: 667 mode |= S_IFCHR; 668 break; 669 case VLNK: 670 mode |= S_IFLNK; 671 /* This is a cosmetic change, symlinks do not have a mode. */ 672 if (vp->v_mount->mnt_flag & MNT_NOSYMFOLLOW) 673 sb->st_mode &= ~ACCESSPERMS; /* 0000 */ 674 else 675 sb->st_mode |= ACCESSPERMS; /* 0777 */ 676 break; 677 case VSOCK: 678 mode |= S_IFSOCK; 679 break; 680 case VFIFO: 681 mode |= S_IFIFO; 682 break; 683 default: 684 return (EBADF); 685 }; 686 sb->st_mode = mode; 687 sb->st_nlink = vap->va_nlink; 688 sb->st_uid = vap->va_uid; 689 sb->st_gid = vap->va_gid; 690 sb->st_rdev = vap->va_rdev; 691 if (vap->va_size > OFF_MAX) 692 return (EOVERFLOW); 693 sb->st_size = vap->va_size; 694 sb->st_atimespec = vap->va_atime; 695 sb->st_mtimespec = vap->va_mtime; 696 sb->st_ctimespec = vap->va_ctime; 697 sb->st_birthtimespec = vap->va_birthtime; 698 699 /* 700 * According to www.opengroup.org, the meaning of st_blksize is 701 * "a filesystem-specific preferred I/O block size for this 702 * object. In some filesystem types, this may vary from file 703 * to file" 704 * Default to PAGE_SIZE after much discussion. 705 */ 706 707 if (vap->va_type == VREG) { 708 sb->st_blksize = vap->va_blocksize; 709 } else if (vn_isdisk(vp, NULL)) { 710 sb->st_blksize = vp->v_rdev->si_bsize_best; 711 if (sb->st_blksize < vp->v_rdev->si_bsize_phys) 712 sb->st_blksize = vp->v_rdev->si_bsize_phys; 713 if (sb->st_blksize < BLKDEV_IOSIZE) 714 sb->st_blksize = BLKDEV_IOSIZE; 715 } else { 716 sb->st_blksize = PAGE_SIZE; 717 } 718 719 sb->st_flags = vap->va_flags; 720 if (suser(td)) 721 sb->st_gen = 0; 722 else 723 sb->st_gen = vap->va_gen; 724 725 #if (S_BLKSIZE == 512) 726 /* Optimize this case */ 727 sb->st_blocks = vap->va_bytes >> 9; 728 #else 729 sb->st_blocks = vap->va_bytes / S_BLKSIZE; 730 #endif 731 return (0); 732 } 733 734 /* 735 * File table vnode ioctl routine. 736 */ 737 static int 738 vn_ioctl(fp, com, data, active_cred, td) 739 struct file *fp; 740 u_long com; 741 void *data; 742 struct ucred *active_cred; 743 struct thread *td; 744 { 745 struct vnode *vp = fp->f_data; 746 struct vnode *vpold; 747 struct vattr vattr; 748 int error; 749 750 switch (vp->v_type) { 751 752 case VREG: 753 case VDIR: 754 if (com == FIONREAD) { 755 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 756 error = VOP_GETATTR(vp, &vattr, active_cred, td); 757 VOP_UNLOCK(vp, 0, td); 758 if (error) 759 return (error); 760 *(int *)data = vattr.va_size - fp->f_offset; 761 return (0); 762 } 763 if (com == FIONBIO || com == FIOASYNC) /* XXX */ 764 return (0); /* XXX */ 765 /* FALLTHROUGH */ 766 767 default: 768 #if 0 769 return (ENOTTY); 770 #endif 771 case VFIFO: 772 case VCHR: 773 case VBLK: 774 if (com == FIODTYPE) { 775 if (vp->v_type != VCHR && vp->v_type != VBLK) 776 return (ENOTTY); 777 *(int *)data = devsw(vp->v_rdev)->d_flags & D_TYPEMASK; 778 return (0); 779 } 780 error = VOP_IOCTL(vp, com, data, fp->f_flag, active_cred, td); 781 if (error == ENOIOCTL) { 782 #ifdef DIAGNOSTIC 783 Debugger("ENOIOCTL leaked through"); 784 #endif 785 error = ENOTTY; 786 } 787 if (error == 0 && com == TIOCSCTTY) { 788 789 /* Do nothing if reassigning same control tty */ 790 sx_slock(&proctree_lock); 791 if (td->td_proc->p_session->s_ttyvp == vp) { 792 sx_sunlock(&proctree_lock); 793 return (0); 794 } 795 796 vpold = td->td_proc->p_session->s_ttyvp; 797 VREF(vp); 798 SESS_LOCK(td->td_proc->p_session); 799 td->td_proc->p_session->s_ttyvp = vp; 800 SESS_UNLOCK(td->td_proc->p_session); 801 802 sx_sunlock(&proctree_lock); 803 804 /* Get rid of reference to old control tty */ 805 if (vpold) 806 vrele(vpold); 807 } 808 return (error); 809 } 810 } 811 812 /* 813 * File table vnode poll routine. 814 */ 815 static int 816 vn_poll(fp, events, active_cred, td) 817 struct file *fp; 818 int events; 819 struct ucred *active_cred; 820 struct thread *td; 821 { 822 struct vnode *vp; 823 #ifdef MAC 824 int error; 825 #endif 826 827 vp = fp->f_data; 828 #ifdef MAC 829 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 830 error = mac_check_vnode_poll(active_cred, fp->f_cred, vp); 831 VOP_UNLOCK(vp, 0, td); 832 if (error) 833 return (error); 834 #endif 835 836 return (VOP_POLL(vp, events, fp->f_cred, td)); 837 } 838 839 /* 840 * Check that the vnode is still valid, and if so 841 * acquire requested lock. 842 */ 843 int 844 #ifndef DEBUG_LOCKS 845 vn_lock(vp, flags, td) 846 #else 847 debug_vn_lock(vp, flags, td, filename, line) 848 #endif 849 struct vnode *vp; 850 int flags; 851 struct thread *td; 852 #ifdef DEBUG_LOCKS 853 const char *filename; 854 int line; 855 #endif 856 { 857 int error; 858 859 do { 860 if ((flags & LK_INTERLOCK) == 0) 861 VI_LOCK(vp); 862 if ((vp->v_iflag & VI_XLOCK) && vp->v_vxproc != curthread) { 863 vp->v_iflag |= VI_XWANT; 864 msleep(vp, VI_MTX(vp), PINOD, "vn_lock", 0); 865 error = ENOENT; 866 if ((flags & LK_RETRY) == 0) { 867 VI_UNLOCK(vp); 868 return (error); 869 } 870 } 871 #ifdef DEBUG_LOCKS 872 vp->filename = filename; 873 vp->line = line; 874 #endif 875 /* 876 * lockmgr drops interlock before it will return for 877 * any reason. So force the code above to relock it. 878 */ 879 error = VOP_LOCK(vp, flags | LK_NOPAUSE | LK_INTERLOCK, td); 880 flags &= ~LK_INTERLOCK; 881 } while (flags & LK_RETRY && error != 0); 882 return (error); 883 } 884 885 /* 886 * File table vnode close routine. 887 */ 888 static int 889 vn_closefile(fp, td) 890 struct file *fp; 891 struct thread *td; 892 { 893 894 fp->f_ops = &badfileops; 895 return (vn_close(fp->f_data, fp->f_flag, fp->f_cred, td)); 896 } 897 898 /* 899 * Preparing to start a filesystem write operation. If the operation is 900 * permitted, then we bump the count of operations in progress and 901 * proceed. If a suspend request is in progress, we wait until the 902 * suspension is over, and then proceed. 903 */ 904 int 905 vn_start_write(vp, mpp, flags) 906 struct vnode *vp; 907 struct mount **mpp; 908 int flags; 909 { 910 struct mount *mp; 911 int error; 912 913 /* 914 * If a vnode is provided, get and return the mount point that 915 * to which it will write. 916 */ 917 if (vp != NULL) { 918 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) { 919 *mpp = NULL; 920 if (error != EOPNOTSUPP) 921 return (error); 922 return (0); 923 } 924 } 925 if ((mp = *mpp) == NULL) 926 return (0); 927 /* 928 * Check on status of suspension. 929 */ 930 while ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { 931 if (flags & V_NOWAIT) 932 return (EWOULDBLOCK); 933 error = tsleep(&mp->mnt_flag, (PUSER - 1) | (flags & PCATCH), 934 "suspfs", 0); 935 if (error) 936 return (error); 937 } 938 if (flags & V_XSLEEP) 939 return (0); 940 mp->mnt_writeopcount++; 941 return (0); 942 } 943 944 /* 945 * Secondary suspension. Used by operations such as vop_inactive 946 * routines that are needed by the higher level functions. These 947 * are allowed to proceed until all the higher level functions have 948 * completed (indicated by mnt_writeopcount dropping to zero). At that 949 * time, these operations are halted until the suspension is over. 950 */ 951 int 952 vn_write_suspend_wait(vp, mp, flags) 953 struct vnode *vp; 954 struct mount *mp; 955 int flags; 956 { 957 int error; 958 959 if (vp != NULL) { 960 if ((error = VOP_GETWRITEMOUNT(vp, &mp)) != 0) { 961 if (error != EOPNOTSUPP) 962 return (error); 963 return (0); 964 } 965 } 966 /* 967 * If we are not suspended or have not yet reached suspended 968 * mode, then let the operation proceed. 969 */ 970 if (mp == NULL || (mp->mnt_kern_flag & MNTK_SUSPENDED) == 0) 971 return (0); 972 if (flags & V_NOWAIT) 973 return (EWOULDBLOCK); 974 /* 975 * Wait for the suspension to finish. 976 */ 977 return (tsleep(&mp->mnt_flag, (PUSER - 1) | (flags & PCATCH), 978 "suspfs", 0)); 979 } 980 981 /* 982 * Filesystem write operation has completed. If we are suspending and this 983 * operation is the last one, notify the suspender that the suspension is 984 * now in effect. 985 */ 986 void 987 vn_finished_write(mp) 988 struct mount *mp; 989 { 990 991 if (mp == NULL) 992 return; 993 mp->mnt_writeopcount--; 994 if (mp->mnt_writeopcount < 0) 995 panic("vn_finished_write: neg cnt"); 996 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && 997 mp->mnt_writeopcount <= 0) 998 wakeup(&mp->mnt_writeopcount); 999 } 1000 1001 /* 1002 * Request a filesystem to suspend write operations. 1003 */ 1004 int 1005 vfs_write_suspend(mp) 1006 struct mount *mp; 1007 { 1008 struct thread *td = curthread; 1009 int error; 1010 1011 if (mp->mnt_kern_flag & MNTK_SUSPEND) 1012 return (0); 1013 mp->mnt_kern_flag |= MNTK_SUSPEND; 1014 if (mp->mnt_writeopcount > 0) 1015 (void) tsleep(&mp->mnt_writeopcount, PUSER - 1, "suspwt", 0); 1016 if ((error = VFS_SYNC(mp, MNT_WAIT, td->td_ucred, td)) != 0) { 1017 vfs_write_resume(mp); 1018 return (error); 1019 } 1020 mp->mnt_kern_flag |= MNTK_SUSPENDED; 1021 return (0); 1022 } 1023 1024 /* 1025 * Request a filesystem to resume write operations. 1026 */ 1027 void 1028 vfs_write_resume(mp) 1029 struct mount *mp; 1030 { 1031 1032 if ((mp->mnt_kern_flag & MNTK_SUSPEND) == 0) 1033 return; 1034 mp->mnt_kern_flag &= ~(MNTK_SUSPEND | MNTK_SUSPENDED); 1035 wakeup(&mp->mnt_writeopcount); 1036 wakeup(&mp->mnt_flag); 1037 } 1038 1039 /* 1040 * Implement kqueues for files by translating it to vnode operation. 1041 */ 1042 static int 1043 vn_kqfilter(struct file *fp, struct knote *kn) 1044 { 1045 1046 return (VOP_KQFILTER(fp->f_data, kn)); 1047 } 1048 1049 /* 1050 * Simplified in-kernel wrapper calls for extended attribute access. 1051 * Both calls pass in a NULL credential, authorizing as "kernel" access. 1052 * Set IO_NODELOCKED in ioflg if the vnode is already locked. 1053 */ 1054 int 1055 vn_extattr_get(struct vnode *vp, int ioflg, int attrnamespace, 1056 const char *attrname, int *buflen, char *buf, struct thread *td) 1057 { 1058 struct uio auio; 1059 struct iovec iov; 1060 int error; 1061 1062 iov.iov_len = *buflen; 1063 iov.iov_base = buf; 1064 1065 auio.uio_iov = &iov; 1066 auio.uio_iovcnt = 1; 1067 auio.uio_rw = UIO_READ; 1068 auio.uio_segflg = UIO_SYSSPACE; 1069 auio.uio_td = td; 1070 auio.uio_offset = 0; 1071 auio.uio_resid = *buflen; 1072 1073 if ((ioflg & IO_NODELOCKED) == 0) 1074 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 1075 1076 /* authorize attribute retrieval as kernel */ 1077 error = VOP_GETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, NULL, 1078 td); 1079 1080 if ((ioflg & IO_NODELOCKED) == 0) 1081 VOP_UNLOCK(vp, 0, td); 1082 1083 if (error == 0) { 1084 *buflen = *buflen - auio.uio_resid; 1085 } 1086 1087 return (error); 1088 } 1089 1090 /* 1091 * XXX failure mode if partially written? 1092 */ 1093 int 1094 vn_extattr_set(struct vnode *vp, int ioflg, int attrnamespace, 1095 const char *attrname, int buflen, char *buf, struct thread *td) 1096 { 1097 struct uio auio; 1098 struct iovec iov; 1099 struct mount *mp; 1100 int error; 1101 1102 iov.iov_len = buflen; 1103 iov.iov_base = buf; 1104 1105 auio.uio_iov = &iov; 1106 auio.uio_iovcnt = 1; 1107 auio.uio_rw = UIO_WRITE; 1108 auio.uio_segflg = UIO_SYSSPACE; 1109 auio.uio_td = td; 1110 auio.uio_offset = 0; 1111 auio.uio_resid = buflen; 1112 1113 if ((ioflg & IO_NODELOCKED) == 0) { 1114 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) 1115 return (error); 1116 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 1117 } 1118 1119 /* authorize attribute setting as kernel */ 1120 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, td); 1121 1122 if ((ioflg & IO_NODELOCKED) == 0) { 1123 vn_finished_write(mp); 1124 VOP_UNLOCK(vp, 0, td); 1125 } 1126 1127 return (error); 1128 } 1129 1130 int 1131 vn_extattr_rm(struct vnode *vp, int ioflg, int attrnamespace, 1132 const char *attrname, struct thread *td) 1133 { 1134 struct mount *mp; 1135 int error; 1136 1137 if ((ioflg & IO_NODELOCKED) == 0) { 1138 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) 1139 return (error); 1140 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 1141 } 1142 1143 /* authorize attribute removal as kernel */ 1144 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, NULL, NULL, td); 1145 1146 if ((ioflg & IO_NODELOCKED) == 0) { 1147 vn_finished_write(mp); 1148 VOP_UNLOCK(vp, 0, td); 1149 } 1150 1151 return (error); 1152 }
Cache object: 307f016ab4b0014061d745e56c77a8d9
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