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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/5.0/sys/kern/vfs_vnops.c 105902 2002-10-25 00:20:37Z mckusick $ 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/lock.h> 51 #include <sys/mac.h> 52 #include <sys/mount.h> 53 #include <sys/mutex.h> 54 #include <sys/namei.h> 55 #include <sys/vnode.h> 56 #include <sys/bio.h> 57 #include <sys/buf.h> 58 #include <sys/filio.h> 59 #include <sys/sx.h> 60 #include <sys/ttycom.h> 61 #include <sys/conf.h> 62 #include <sys/syslog.h> 63 64 #include <machine/limits.h> 65 66 static int vn_closefile(struct file *fp, struct thread *td); 67 static int vn_ioctl(struct file *fp, u_long com, void *data, 68 struct ucred *active_cred, struct thread *td); 69 static int vn_read(struct file *fp, struct uio *uio, 70 struct ucred *active_cred, int flags, struct thread *td); 71 static int vn_poll(struct file *fp, int events, struct ucred *active_cred, 72 struct thread *td); 73 static int vn_kqfilter(struct file *fp, struct knote *kn); 74 static int vn_statfile(struct file *fp, struct stat *sb, 75 struct ucred *active_cred, struct thread *td); 76 static int vn_write(struct file *fp, struct uio *uio, 77 struct ucred *active_cred, int flags, struct thread *td); 78 79 struct fileops vnops = { 80 vn_read, vn_write, vn_ioctl, vn_poll, vn_kqfilter, 81 vn_statfile, vn_closefile 82 }; 83 84 int 85 vn_open(ndp, flagp, cmode) 86 register struct nameidata *ndp; 87 int *flagp, cmode; 88 { 89 struct thread *td = ndp->ni_cnd.cn_thread; 90 91 return (vn_open_cred(ndp, flagp, cmode, td->td_ucred)); 92 } 93 94 /* 95 * Common code for vnode open operations. 96 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine. 97 * 98 * Note that this does NOT free nameidata for the successful case, 99 * due to the NDINIT being done elsewhere. 100 */ 101 int 102 vn_open_cred(ndp, flagp, cmode, cred) 103 register struct nameidata *ndp; 104 int *flagp, cmode; 105 struct ucred *cred; 106 { 107 struct vnode *vp; 108 struct mount *mp; 109 struct thread *td = ndp->ni_cnd.cn_thread; 110 struct vattr vat; 111 struct vattr *vap = &vat; 112 int mode, fmode, error; 113 #ifdef LOOKUP_SHARED 114 int exclusive; /* The current intended lock state */ 115 116 exclusive = 0; 117 #endif 118 119 restart: 120 fmode = *flagp; 121 if (fmode & O_CREAT) { 122 ndp->ni_cnd.cn_nameiop = CREATE; 123 ndp->ni_cnd.cn_flags = LOCKPARENT | LOCKLEAF; 124 if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0) 125 ndp->ni_cnd.cn_flags |= FOLLOW; 126 bwillwrite(); 127 if ((error = namei(ndp)) != 0) 128 return (error); 129 if (ndp->ni_vp == NULL) { 130 VATTR_NULL(vap); 131 vap->va_type = VREG; 132 vap->va_mode = cmode; 133 if (fmode & O_EXCL) 134 vap->va_vaflags |= VA_EXCLUSIVE; 135 if (vn_start_write(ndp->ni_dvp, &mp, V_NOWAIT) != 0) { 136 NDFREE(ndp, NDF_ONLY_PNBUF); 137 vput(ndp->ni_dvp); 138 if ((error = vn_start_write(NULL, &mp, 139 V_XSLEEP | PCATCH)) != 0) 140 return (error); 141 goto restart; 142 } 143 #ifdef MAC 144 error = mac_check_vnode_create(cred, ndp->ni_dvp, 145 &ndp->ni_cnd, vap); 146 if (error == 0) { 147 #endif 148 VOP_LEASE(ndp->ni_dvp, td, cred, LEASE_WRITE); 149 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp, 150 &ndp->ni_cnd, vap); 151 #ifdef MAC 152 } 153 #endif 154 vput(ndp->ni_dvp); 155 vn_finished_write(mp); 156 if (error) { 157 NDFREE(ndp, NDF_ONLY_PNBUF); 158 return (error); 159 } 160 ASSERT_VOP_UNLOCKED(ndp->ni_dvp, "create"); 161 ASSERT_VOP_LOCKED(ndp->ni_vp, "create"); 162 fmode &= ~O_TRUNC; 163 vp = ndp->ni_vp; 164 #ifdef LOOKUP_SHARED 165 exclusive = 1; 166 #endif 167 } else { 168 if (ndp->ni_dvp == ndp->ni_vp) 169 vrele(ndp->ni_dvp); 170 else 171 vput(ndp->ni_dvp); 172 ndp->ni_dvp = NULL; 173 vp = ndp->ni_vp; 174 if (fmode & O_EXCL) { 175 error = EEXIST; 176 goto bad; 177 } 178 fmode &= ~O_CREAT; 179 } 180 } else { 181 ndp->ni_cnd.cn_nameiop = LOOKUP; 182 #ifdef LOOKUP_SHARED 183 ndp->ni_cnd.cn_flags = 184 ((fmode & O_NOFOLLOW) ? NOFOLLOW : FOLLOW) | 185 LOCKSHARED | LOCKLEAF; 186 #else 187 ndp->ni_cnd.cn_flags = 188 ((fmode & O_NOFOLLOW) ? NOFOLLOW : FOLLOW) | LOCKLEAF; 189 #endif 190 if ((error = namei(ndp)) != 0) 191 return (error); 192 vp = ndp->ni_vp; 193 } 194 if (vp->v_type == VLNK) { 195 error = EMLINK; 196 goto bad; 197 } 198 if (vp->v_type == VSOCK) { 199 error = EOPNOTSUPP; 200 goto bad; 201 } 202 mode = 0; 203 if (fmode & (FWRITE | O_TRUNC)) { 204 if (vp->v_type == VDIR) { 205 error = EISDIR; 206 goto bad; 207 } 208 mode |= VWRITE; 209 } 210 if (fmode & FREAD) 211 mode |= VREAD; 212 if (fmode & O_APPEND) 213 mode |= VAPPEND; 214 #ifdef MAC 215 error = mac_check_vnode_open(cred, vp, mode); 216 if (error) 217 goto bad; 218 #endif 219 if ((fmode & O_CREAT) == 0) { 220 if (mode & VWRITE) { 221 error = vn_writechk(vp); 222 if (error) 223 goto bad; 224 } 225 if (mode) { 226 error = VOP_ACCESS(vp, mode, cred, td); 227 if (error) 228 goto bad; 229 } 230 } 231 if ((error = VOP_GETATTR(vp, vap, cred, td)) == 0) { 232 vp->v_cachedfs = vap->va_fsid; 233 vp->v_cachedid = vap->va_fileid; 234 } 235 if ((error = VOP_OPEN(vp, fmode, cred, td)) != 0) 236 goto bad; 237 /* 238 * Make sure that a VM object is created for VMIO support. 239 */ 240 if (vn_canvmio(vp) == TRUE) { 241 #ifdef LOOKUP_SHARED 242 int flock; 243 244 if (!exclusive && VOP_GETVOBJECT(vp, NULL) != 0) 245 VOP_LOCK(vp, LK_UPGRADE, td); 246 /* 247 * In cases where the object is marked as dead object_create 248 * will unlock and relock exclusive. It is safe to call in 249 * here with a shared lock because we only examine fields that 250 * the shared lock guarantees will be stable. In the UPGRADE 251 * case it is not likely that anyone has used this vnode yet 252 * so there will be no contention. The logic after this call 253 * restores the requested locking state. 254 */ 255 #endif 256 if ((error = vfs_object_create(vp, td, cred)) != 0) { 257 VOP_UNLOCK(vp, 0, td); 258 VOP_CLOSE(vp, fmode, cred, td); 259 NDFREE(ndp, NDF_ONLY_PNBUF); 260 vrele(vp); 261 *flagp = fmode; 262 return (error); 263 } 264 #ifdef LOOKUP_SHARED 265 flock = VOP_ISLOCKED(vp, td); 266 if (!exclusive && flock == LK_EXCLUSIVE) 267 VOP_LOCK(vp, LK_DOWNGRADE, td); 268 #endif 269 } 270 271 if (fmode & FWRITE) 272 vp->v_writecount++; 273 *flagp = fmode; 274 return (0); 275 bad: 276 NDFREE(ndp, NDF_ONLY_PNBUF); 277 vput(vp); 278 *flagp = fmode; 279 return (error); 280 } 281 282 /* 283 * Check for write permissions on the specified vnode. 284 * Prototype text segments cannot be written. 285 */ 286 int 287 vn_writechk(vp) 288 register struct vnode *vp; 289 { 290 291 ASSERT_VOP_LOCKED(vp, "vn_writechk"); 292 /* 293 * If there's shared text associated with 294 * the vnode, try to free it up once. If 295 * we fail, we can't allow writing. 296 */ 297 if (vp->v_vflag & VV_TEXT) 298 return (ETXTBSY); 299 300 return (0); 301 } 302 303 /* 304 * Vnode close call 305 */ 306 int 307 vn_close(vp, flags, file_cred, td) 308 register struct vnode *vp; 309 int flags; 310 struct ucred *file_cred; 311 struct thread *td; 312 { 313 int error; 314 315 if (flags & FWRITE) 316 vp->v_writecount--; 317 error = VOP_CLOSE(vp, flags, file_cred, td); 318 /* 319 * XXX - In certain instances VOP_CLOSE has to do the vrele 320 * itself. If the vrele has been done, it will return EAGAIN 321 * to indicate that the vrele should not be done again. When 322 * this happens, we just return success. The correct thing to 323 * do would be to have all VOP_CLOSE instances do the vrele. 324 */ 325 if (error == EAGAIN) 326 return (0); 327 vrele(vp); 328 return (error); 329 } 330 331 /* 332 * Sequential heuristic - detect sequential operation 333 */ 334 static __inline 335 int 336 sequential_heuristic(struct uio *uio, struct file *fp) 337 { 338 339 if ((uio->uio_offset == 0 && fp->f_seqcount > 0) || 340 uio->uio_offset == fp->f_nextoff) { 341 /* 342 * XXX we assume that the filesystem block size is 343 * the default. Not true, but still gives us a pretty 344 * good indicator of how sequential the read operations 345 * are. 346 */ 347 fp->f_seqcount += (uio->uio_resid + BKVASIZE - 1) / BKVASIZE; 348 if (fp->f_seqcount >= 127) 349 fp->f_seqcount = 127; 350 return(fp->f_seqcount << 16); 351 } 352 353 /* 354 * Not sequential, quick draw-down of seqcount 355 */ 356 if (fp->f_seqcount > 1) 357 fp->f_seqcount = 1; 358 else 359 fp->f_seqcount = 0; 360 return(0); 361 } 362 363 /* 364 * Package up an I/O request on a vnode into a uio and do it. 365 */ 366 int 367 vn_rdwr(rw, vp, base, len, offset, segflg, ioflg, active_cred, file_cred, 368 aresid, td) 369 enum uio_rw rw; 370 struct vnode *vp; 371 caddr_t base; 372 int len; 373 off_t offset; 374 enum uio_seg segflg; 375 int ioflg; 376 struct ucred *active_cred; 377 struct ucred *file_cred; 378 int *aresid; 379 struct thread *td; 380 { 381 struct uio auio; 382 struct iovec aiov; 383 struct mount *mp; 384 struct ucred *cred; 385 int error; 386 387 if ((ioflg & IO_NODELOCKED) == 0) { 388 mp = NULL; 389 if (rw == UIO_WRITE) { 390 if (vp->v_type != VCHR && 391 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) 392 != 0) 393 return (error); 394 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 395 } else { 396 /* 397 * XXX This should be LK_SHARED but I don't trust VFS 398 * enough to leave it like that until it has been 399 * reviewed further. 400 */ 401 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 402 } 403 404 } 405 auio.uio_iov = &aiov; 406 auio.uio_iovcnt = 1; 407 aiov.iov_base = base; 408 aiov.iov_len = len; 409 auio.uio_resid = len; 410 auio.uio_offset = offset; 411 auio.uio_segflg = segflg; 412 auio.uio_rw = rw; 413 auio.uio_td = td; 414 error = 0; 415 #ifdef MAC 416 if ((ioflg & IO_NOMACCHECK) == 0) { 417 if (rw == UIO_READ) 418 error = mac_check_vnode_read(active_cred, file_cred, 419 vp); 420 else 421 error = mac_check_vnode_write(active_cred, file_cred, 422 vp); 423 } 424 #endif 425 if (error == 0) { 426 if (file_cred) 427 cred = file_cred; 428 else 429 cred = active_cred; 430 if (rw == UIO_READ) 431 error = VOP_READ(vp, &auio, ioflg, cred); 432 else 433 error = VOP_WRITE(vp, &auio, ioflg, cred); 434 } 435 if (aresid) 436 *aresid = auio.uio_resid; 437 else 438 if (auio.uio_resid && error == 0) 439 error = EIO; 440 if ((ioflg & IO_NODELOCKED) == 0) { 441 if (rw == UIO_WRITE) 442 vn_finished_write(mp); 443 VOP_UNLOCK(vp, 0, td); 444 } 445 return (error); 446 } 447 448 /* 449 * Package up an I/O request on a vnode into a uio and do it. The I/O 450 * request is split up into smaller chunks and we try to avoid saturating 451 * the buffer cache while potentially holding a vnode locked, so we 452 * check bwillwrite() before calling vn_rdwr(). We also call uio_yield() 453 * to give other processes a chance to lock the vnode (either other processes 454 * core'ing the same binary, or unrelated processes scanning the directory). 455 */ 456 int 457 vn_rdwr_inchunks(rw, vp, base, len, offset, segflg, ioflg, active_cred, 458 file_cred, aresid, td) 459 enum uio_rw rw; 460 struct vnode *vp; 461 caddr_t base; 462 int len; 463 off_t offset; 464 enum uio_seg segflg; 465 int ioflg; 466 struct ucred *active_cred; 467 struct ucred *file_cred; 468 int *aresid; 469 struct thread *td; 470 { 471 int error = 0; 472 473 do { 474 int chunk = (len > MAXBSIZE) ? MAXBSIZE : len; 475 476 if (rw != UIO_READ && vp->v_type == VREG) 477 bwillwrite(); 478 error = vn_rdwr(rw, vp, base, chunk, offset, segflg, 479 ioflg, active_cred, file_cred, aresid, td); 480 len -= chunk; /* aresid calc already includes length */ 481 if (error) 482 break; 483 offset += chunk; 484 base += chunk; 485 uio_yield(); 486 } while (len); 487 if (aresid) 488 *aresid += len; 489 return (error); 490 } 491 492 /* 493 * File table vnode read routine. 494 */ 495 static int 496 vn_read(fp, uio, active_cred, flags, td) 497 struct file *fp; 498 struct uio *uio; 499 struct ucred *active_cred; 500 struct thread *td; 501 int flags; 502 { 503 struct vnode *vp; 504 int error, ioflag; 505 506 mtx_lock(&Giant); 507 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", 508 uio->uio_td, td)); 509 vp = (struct vnode *)fp->f_data; 510 ioflag = 0; 511 if (fp->f_flag & FNONBLOCK) 512 ioflag |= IO_NDELAY; 513 if (fp->f_flag & O_DIRECT) 514 ioflag |= IO_DIRECT; 515 VOP_LEASE(vp, td, fp->f_cred, LEASE_READ); 516 /* 517 * According to McKusick the vn lock is protecting f_offset here. 518 * Once this field has it's own lock we can acquire this shared. 519 */ 520 vn_lock(vp, LK_EXCLUSIVE | LK_NOPAUSE | LK_RETRY, td); 521 if ((flags & FOF_OFFSET) == 0) 522 uio->uio_offset = fp->f_offset; 523 524 ioflag |= sequential_heuristic(uio, fp); 525 526 #ifdef MAC 527 error = mac_check_vnode_read(active_cred, fp->f_cred, vp); 528 if (error == 0) 529 #endif 530 error = VOP_READ(vp, uio, ioflag, fp->f_cred); 531 if ((flags & FOF_OFFSET) == 0) 532 fp->f_offset = uio->uio_offset; 533 fp->f_nextoff = uio->uio_offset; 534 VOP_UNLOCK(vp, 0, td); 535 mtx_unlock(&Giant); 536 return (error); 537 } 538 539 /* 540 * File table vnode write routine. 541 */ 542 static int 543 vn_write(fp, uio, active_cred, flags, td) 544 struct file *fp; 545 struct uio *uio; 546 struct ucred *active_cred; 547 struct thread *td; 548 int flags; 549 { 550 struct vnode *vp; 551 struct mount *mp; 552 int error, ioflag; 553 554 mtx_lock(&Giant); 555 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", 556 uio->uio_td, td)); 557 vp = (struct vnode *)fp->f_data; 558 if (vp->v_type == VREG) 559 bwillwrite(); 560 ioflag = IO_UNIT; 561 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 562 ioflag |= IO_APPEND; 563 if (fp->f_flag & FNONBLOCK) 564 ioflag |= IO_NDELAY; 565 if (fp->f_flag & O_DIRECT) 566 ioflag |= IO_DIRECT; 567 if ((fp->f_flag & O_FSYNC) || 568 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS))) 569 ioflag |= IO_SYNC; 570 mp = NULL; 571 if (vp->v_type != VCHR && 572 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0) { 573 mtx_unlock(&Giant); 574 return (error); 575 } 576 VOP_LEASE(vp, td, fp->f_cred, LEASE_WRITE); 577 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 578 if ((flags & FOF_OFFSET) == 0) 579 uio->uio_offset = fp->f_offset; 580 ioflag |= sequential_heuristic(uio, fp); 581 #ifdef MAC 582 error = mac_check_vnode_write(active_cred, fp->f_cred, vp); 583 if (error == 0) 584 #endif 585 error = VOP_WRITE(vp, uio, ioflag, fp->f_cred); 586 if ((flags & FOF_OFFSET) == 0) 587 fp->f_offset = uio->uio_offset; 588 fp->f_nextoff = uio->uio_offset; 589 VOP_UNLOCK(vp, 0, td); 590 vn_finished_write(mp); 591 mtx_unlock(&Giant); 592 return (error); 593 } 594 595 /* 596 * File table vnode stat routine. 597 */ 598 static int 599 vn_statfile(fp, sb, active_cred, td) 600 struct file *fp; 601 struct stat *sb; 602 struct ucred *active_cred; 603 struct thread *td; 604 { 605 struct vnode *vp = (struct vnode *)fp->f_data; 606 int error; 607 608 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 609 error = vn_stat(vp, sb, active_cred, fp->f_cred, td); 610 VOP_UNLOCK(vp, 0, td); 611 612 return (error); 613 } 614 615 /* 616 * Stat a vnode; implementation for the stat syscall 617 */ 618 int 619 vn_stat(vp, sb, active_cred, file_cred, td) 620 struct vnode *vp; 621 register struct stat *sb; 622 struct ucred *active_cred; 623 struct ucred *file_cred; 624 struct thread *td; 625 { 626 struct vattr vattr; 627 register struct vattr *vap; 628 int error; 629 u_short mode; 630 631 #ifdef MAC 632 error = mac_check_vnode_stat(active_cred, file_cred, vp); 633 if (error) 634 return (error); 635 #endif 636 637 vap = &vattr; 638 error = VOP_GETATTR(vp, vap, active_cred, td); 639 if (error) 640 return (error); 641 642 vp->v_cachedfs = vap->va_fsid; 643 vp->v_cachedid = vap->va_fileid; 644 645 /* 646 * Zero the spare stat fields 647 */ 648 bzero(sb, sizeof *sb); 649 650 /* 651 * Copy from vattr table 652 */ 653 if (vap->va_fsid != VNOVAL) 654 sb->st_dev = vap->va_fsid; 655 else 656 sb->st_dev = vp->v_mount->mnt_stat.f_fsid.val[0]; 657 sb->st_ino = vap->va_fileid; 658 mode = vap->va_mode; 659 switch (vap->va_type) { 660 case VREG: 661 mode |= S_IFREG; 662 break; 663 case VDIR: 664 mode |= S_IFDIR; 665 break; 666 case VBLK: 667 mode |= S_IFBLK; 668 break; 669 case VCHR: 670 mode |= S_IFCHR; 671 break; 672 case VLNK: 673 mode |= S_IFLNK; 674 /* This is a cosmetic change, symlinks do not have a mode. */ 675 if (vp->v_mount->mnt_flag & MNT_NOSYMFOLLOW) 676 sb->st_mode &= ~ACCESSPERMS; /* 0000 */ 677 else 678 sb->st_mode |= ACCESSPERMS; /* 0777 */ 679 break; 680 case VSOCK: 681 mode |= S_IFSOCK; 682 break; 683 case VFIFO: 684 mode |= S_IFIFO; 685 break; 686 default: 687 return (EBADF); 688 }; 689 sb->st_mode = mode; 690 sb->st_nlink = vap->va_nlink; 691 sb->st_uid = vap->va_uid; 692 sb->st_gid = vap->va_gid; 693 sb->st_rdev = vap->va_rdev; 694 if (vap->va_size > OFF_MAX) 695 return (EOVERFLOW); 696 sb->st_size = vap->va_size; 697 sb->st_atimespec = vap->va_atime; 698 sb->st_mtimespec = vap->va_mtime; 699 sb->st_ctimespec = vap->va_ctime; 700 sb->st_birthtimespec = vap->va_birthtime; 701 702 /* 703 * According to www.opengroup.org, the meaning of st_blksize is 704 * "a filesystem-specific preferred I/O block size for this 705 * object. In some filesystem types, this may vary from file 706 * to file" 707 * Default to PAGE_SIZE after much discussion. 708 */ 709 710 if (vap->va_type == VREG) { 711 sb->st_blksize = vap->va_blocksize; 712 } else if (vn_isdisk(vp, NULL)) { 713 sb->st_blksize = vp->v_rdev->si_bsize_best; 714 if (sb->st_blksize < vp->v_rdev->si_bsize_phys) 715 sb->st_blksize = vp->v_rdev->si_bsize_phys; 716 if (sb->st_blksize < BLKDEV_IOSIZE) 717 sb->st_blksize = BLKDEV_IOSIZE; 718 } else { 719 sb->st_blksize = PAGE_SIZE; 720 } 721 722 sb->st_flags = vap->va_flags; 723 if (suser(td)) 724 sb->st_gen = 0; 725 else 726 sb->st_gen = vap->va_gen; 727 728 #if (S_BLKSIZE == 512) 729 /* Optimize this case */ 730 sb->st_blocks = vap->va_bytes >> 9; 731 #else 732 sb->st_blocks = vap->va_bytes / S_BLKSIZE; 733 #endif 734 return (0); 735 } 736 737 /* 738 * File table vnode ioctl routine. 739 */ 740 static int 741 vn_ioctl(fp, com, data, active_cred, td) 742 struct file *fp; 743 u_long com; 744 void *data; 745 struct ucred *active_cred; 746 struct thread *td; 747 { 748 register struct vnode *vp = ((struct vnode *)fp->f_data); 749 struct vnode *vpold; 750 struct vattr vattr; 751 int error; 752 753 switch (vp->v_type) { 754 755 case VREG: 756 case VDIR: 757 if (com == FIONREAD) { 758 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 759 error = VOP_GETATTR(vp, &vattr, active_cred, td); 760 VOP_UNLOCK(vp, 0, td); 761 if (error) 762 return (error); 763 *(int *)data = vattr.va_size - fp->f_offset; 764 return (0); 765 } 766 if (com == FIONBIO || com == FIOASYNC) /* XXX */ 767 return (0); /* XXX */ 768 /* FALLTHROUGH */ 769 770 default: 771 #if 0 772 return (ENOTTY); 773 #endif 774 case VFIFO: 775 case VCHR: 776 case VBLK: 777 if (com == FIODTYPE) { 778 if (vp->v_type != VCHR && vp->v_type != VBLK) 779 return (ENOTTY); 780 *(int *)data = devsw(vp->v_rdev)->d_flags & D_TYPEMASK; 781 return (0); 782 } 783 error = VOP_IOCTL(vp, com, data, fp->f_flag, active_cred, td); 784 if (error == ENOIOCTL) { 785 #ifdef DIAGNOSTIC 786 Debugger("ENOIOCTL leaked through"); 787 #endif 788 error = ENOTTY; 789 } 790 if (error == 0 && com == TIOCSCTTY) { 791 792 /* Do nothing if reassigning same control tty */ 793 sx_slock(&proctree_lock); 794 if (td->td_proc->p_session->s_ttyvp == vp) { 795 sx_sunlock(&proctree_lock); 796 return (0); 797 } 798 799 vpold = td->td_proc->p_session->s_ttyvp; 800 VREF(vp); 801 SESS_LOCK(td->td_proc->p_session); 802 td->td_proc->p_session->s_ttyvp = vp; 803 SESS_UNLOCK(td->td_proc->p_session); 804 805 sx_sunlock(&proctree_lock); 806 807 /* Get rid of reference to old control tty */ 808 if (vpold) 809 vrele(vpold); 810 } 811 return (error); 812 } 813 } 814 815 /* 816 * File table vnode poll routine. 817 */ 818 static int 819 vn_poll(fp, events, active_cred, td) 820 struct file *fp; 821 int events; 822 struct ucred *active_cred; 823 struct thread *td; 824 { 825 struct vnode *vp; 826 #ifdef MAC 827 int error; 828 #endif 829 830 vp = (struct vnode *)fp->f_data; 831 #ifdef MAC 832 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 833 error = mac_check_vnode_poll(active_cred, fp->f_cred, vp); 834 VOP_UNLOCK(vp, 0, td); 835 if (error) 836 return (error); 837 #endif 838 839 return (VOP_POLL(vp, events, fp->f_cred, td)); 840 } 841 842 /* 843 * Check that the vnode is still valid, and if so 844 * acquire requested lock. 845 */ 846 int 847 #ifndef DEBUG_LOCKS 848 vn_lock(vp, flags, td) 849 #else 850 debug_vn_lock(vp, flags, td, filename, line) 851 #endif 852 struct vnode *vp; 853 int flags; 854 struct thread *td; 855 #ifdef DEBUG_LOCKS 856 const char *filename; 857 int line; 858 #endif 859 { 860 int error; 861 862 do { 863 if ((flags & LK_INTERLOCK) == 0) 864 VI_LOCK(vp); 865 if ((vp->v_iflag & VI_XLOCK) && vp->v_vxproc != curthread) { 866 vp->v_iflag |= VI_XWANT; 867 msleep(vp, VI_MTX(vp), PINOD, "vn_lock", 0); 868 error = ENOENT; 869 if ((flags & LK_RETRY) == 0) { 870 VI_UNLOCK(vp); 871 return (error); 872 } 873 } 874 #ifdef DEBUG_LOCKS 875 vp->filename = filename; 876 vp->line = line; 877 #endif 878 /* 879 * lockmgr drops interlock before it will return for 880 * any reason. So force the code above to relock it. 881 */ 882 error = VOP_LOCK(vp, flags | LK_NOPAUSE | LK_INTERLOCK, td); 883 flags &= ~LK_INTERLOCK; 884 } while (flags & LK_RETRY && error != 0); 885 return (error); 886 } 887 888 /* 889 * File table vnode close routine. 890 */ 891 static int 892 vn_closefile(fp, td) 893 struct file *fp; 894 struct thread *td; 895 { 896 897 fp->f_ops = &badfileops; 898 return (vn_close(((struct vnode *)fp->f_data), fp->f_flag, 899 fp->f_cred, td)); 900 } 901 902 /* 903 * Preparing to start a filesystem write operation. If the operation is 904 * permitted, then we bump the count of operations in progress and 905 * proceed. If a suspend request is in progress, we wait until the 906 * suspension is over, and then proceed. 907 */ 908 int 909 vn_start_write(vp, mpp, flags) 910 struct vnode *vp; 911 struct mount **mpp; 912 int flags; 913 { 914 struct mount *mp; 915 int error; 916 917 /* 918 * If a vnode is provided, get and return the mount point that 919 * to which it will write. 920 */ 921 if (vp != NULL) { 922 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) { 923 *mpp = NULL; 924 if (error != EOPNOTSUPP) 925 return (error); 926 return (0); 927 } 928 } 929 if ((mp = *mpp) == NULL) 930 return (0); 931 /* 932 * Check on status of suspension. 933 */ 934 while ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { 935 if (flags & V_NOWAIT) 936 return (EWOULDBLOCK); 937 error = tsleep(&mp->mnt_flag, (PUSER - 1) | (flags & PCATCH), 938 "suspfs", 0); 939 if (error) 940 return (error); 941 } 942 if (flags & V_XSLEEP) 943 return (0); 944 mp->mnt_writeopcount++; 945 return (0); 946 } 947 948 /* 949 * Secondary suspension. Used by operations such as vop_inactive 950 * routines that are needed by the higher level functions. These 951 * are allowed to proceed until all the higher level functions have 952 * completed (indicated by mnt_writeopcount dropping to zero). At that 953 * time, these operations are halted until the suspension is over. 954 */ 955 int 956 vn_write_suspend_wait(vp, mp, flags) 957 struct vnode *vp; 958 struct mount *mp; 959 int flags; 960 { 961 int error; 962 963 if (vp != NULL) { 964 if ((error = VOP_GETWRITEMOUNT(vp, &mp)) != 0) { 965 if (error != EOPNOTSUPP) 966 return (error); 967 return (0); 968 } 969 } 970 /* 971 * If we are not suspended or have not yet reached suspended 972 * mode, then let the operation proceed. 973 */ 974 if (mp == NULL || (mp->mnt_kern_flag & MNTK_SUSPENDED) == 0) 975 return (0); 976 if (flags & V_NOWAIT) 977 return (EWOULDBLOCK); 978 /* 979 * Wait for the suspension to finish. 980 */ 981 return (tsleep(&mp->mnt_flag, (PUSER - 1) | (flags & PCATCH), 982 "suspfs", 0)); 983 } 984 985 /* 986 * Filesystem write operation has completed. If we are suspending and this 987 * operation is the last one, notify the suspender that the suspension is 988 * now in effect. 989 */ 990 void 991 vn_finished_write(mp) 992 struct mount *mp; 993 { 994 995 if (mp == NULL) 996 return; 997 mp->mnt_writeopcount--; 998 if (mp->mnt_writeopcount < 0) 999 panic("vn_finished_write: neg cnt"); 1000 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && 1001 mp->mnt_writeopcount <= 0) 1002 wakeup(&mp->mnt_writeopcount); 1003 } 1004 1005 /* 1006 * Request a filesystem to suspend write operations. 1007 */ 1008 int 1009 vfs_write_suspend(mp) 1010 struct mount *mp; 1011 { 1012 struct thread *td = curthread; 1013 int error; 1014 1015 if (mp->mnt_kern_flag & MNTK_SUSPEND) 1016 return (0); 1017 mp->mnt_kern_flag |= MNTK_SUSPEND; 1018 if (mp->mnt_writeopcount > 0) 1019 (void) tsleep(&mp->mnt_writeopcount, PUSER - 1, "suspwt", 0); 1020 if ((error = VFS_SYNC(mp, MNT_WAIT, td->td_ucred, td)) != 0) { 1021 vfs_write_resume(mp); 1022 return (error); 1023 } 1024 mp->mnt_kern_flag |= MNTK_SUSPENDED; 1025 return (0); 1026 } 1027 1028 /* 1029 * Request a filesystem to resume write operations. 1030 */ 1031 void 1032 vfs_write_resume(mp) 1033 struct mount *mp; 1034 { 1035 1036 if ((mp->mnt_kern_flag & MNTK_SUSPEND) == 0) 1037 return; 1038 mp->mnt_kern_flag &= ~(MNTK_SUSPEND | MNTK_SUSPENDED); 1039 wakeup(&mp->mnt_writeopcount); 1040 wakeup(&mp->mnt_flag); 1041 } 1042 1043 /* 1044 * Implement kqueues for files by translating it to vnode operation. 1045 */ 1046 static int 1047 vn_kqfilter(struct file *fp, struct knote *kn) 1048 { 1049 1050 return (VOP_KQFILTER(((struct vnode *)fp->f_data), kn)); 1051 } 1052 1053 /* 1054 * Simplified in-kernel wrapper calls for extended attribute access. 1055 * Both calls pass in a NULL credential, authorizing as "kernel" access. 1056 * Set IO_NODELOCKED in ioflg if the vnode is already locked. 1057 */ 1058 int 1059 vn_extattr_get(struct vnode *vp, int ioflg, int attrnamespace, 1060 const char *attrname, int *buflen, char *buf, struct thread *td) 1061 { 1062 struct uio auio; 1063 struct iovec iov; 1064 int error; 1065 1066 iov.iov_len = *buflen; 1067 iov.iov_base = buf; 1068 1069 auio.uio_iov = &iov; 1070 auio.uio_iovcnt = 1; 1071 auio.uio_rw = UIO_READ; 1072 auio.uio_segflg = UIO_SYSSPACE; 1073 auio.uio_td = td; 1074 auio.uio_offset = 0; 1075 auio.uio_resid = *buflen; 1076 1077 if ((ioflg & IO_NODELOCKED) == 0) 1078 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 1079 1080 /* authorize attribute retrieval as kernel */ 1081 error = VOP_GETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, NULL, 1082 td); 1083 1084 if ((ioflg & IO_NODELOCKED) == 0) 1085 VOP_UNLOCK(vp, 0, td); 1086 1087 if (error == 0) { 1088 *buflen = *buflen - auio.uio_resid; 1089 } 1090 1091 return (error); 1092 } 1093 1094 /* 1095 * XXX failure mode if partially written? 1096 */ 1097 int 1098 vn_extattr_set(struct vnode *vp, int ioflg, int attrnamespace, 1099 const char *attrname, int buflen, char *buf, struct thread *td) 1100 { 1101 struct uio auio; 1102 struct iovec iov; 1103 struct mount *mp; 1104 int error; 1105 1106 iov.iov_len = buflen; 1107 iov.iov_base = buf; 1108 1109 auio.uio_iov = &iov; 1110 auio.uio_iovcnt = 1; 1111 auio.uio_rw = UIO_WRITE; 1112 auio.uio_segflg = UIO_SYSSPACE; 1113 auio.uio_td = td; 1114 auio.uio_offset = 0; 1115 auio.uio_resid = buflen; 1116 1117 if ((ioflg & IO_NODELOCKED) == 0) { 1118 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) 1119 return (error); 1120 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 1121 } 1122 1123 /* authorize attribute setting as kernel */ 1124 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, td); 1125 1126 if ((ioflg & IO_NODELOCKED) == 0) { 1127 vn_finished_write(mp); 1128 VOP_UNLOCK(vp, 0, td); 1129 } 1130 1131 return (error); 1132 } 1133 1134 int 1135 vn_extattr_rm(struct vnode *vp, int ioflg, int attrnamespace, 1136 const char *attrname, struct thread *td) 1137 { 1138 struct mount *mp; 1139 int error; 1140 1141 if ((ioflg & IO_NODELOCKED) == 0) { 1142 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) 1143 return (error); 1144 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 1145 } 1146 1147 /* authorize attribute removal as kernel */ 1148 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, NULL, NULL, td); 1149 1150 if ((ioflg & IO_NODELOCKED) == 0) { 1151 vn_finished_write(mp); 1152 VOP_UNLOCK(vp, 0, td); 1153 } 1154 1155 return (error); 1156 }
Cache object: 5b45fdf2ef07c660675182988e5da7db
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