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 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)vfs_vnops.c 8.2 (Berkeley) 1/21/94 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 #include <sys/param.h> 41 #include <sys/systm.h> 42 #include <sys/fcntl.h> 43 #include <sys/file.h> 44 #include <sys/kdb.h> 45 #include <sys/stat.h> 46 #include <sys/priv.h> 47 #include <sys/proc.h> 48 #include <sys/limits.h> 49 #include <sys/lock.h> 50 #include <sys/mount.h> 51 #include <sys/mutex.h> 52 #include <sys/namei.h> 53 #include <sys/vnode.h> 54 #include <sys/bio.h> 55 #include <sys/buf.h> 56 #include <sys/filio.h> 57 #include <sys/resourcevar.h> 58 #include <sys/sx.h> 59 #include <sys/sysctl.h> 60 #include <sys/ttycom.h> 61 #include <sys/conf.h> 62 #include <sys/syslog.h> 63 #include <sys/unistd.h> 64 65 #include <security/audit/audit.h> 66 #include <security/mac/mac_framework.h> 67 68 #include <vm/vm.h> 69 #include <vm/vm_extern.h> 70 #include <vm/pmap.h> 71 #include <vm/vm_map.h> 72 #include <vm/vm_object.h> 73 #include <vm/vm_page.h> 74 75 static fo_rdwr_t vn_read; 76 static fo_rdwr_t vn_write; 77 static fo_rdwr_t vn_io_fault; 78 static fo_truncate_t vn_truncate; 79 static fo_ioctl_t vn_ioctl; 80 static fo_poll_t vn_poll; 81 static fo_kqfilter_t vn_kqfilter; 82 static fo_stat_t vn_statfile; 83 static fo_close_t vn_closefile; 84 85 struct fileops vnops = { 86 .fo_read = vn_io_fault, 87 .fo_write = vn_io_fault, 88 .fo_truncate = vn_truncate, 89 .fo_ioctl = vn_ioctl, 90 .fo_poll = vn_poll, 91 .fo_kqfilter = vn_kqfilter, 92 .fo_stat = vn_statfile, 93 .fo_close = vn_closefile, 94 .fo_chmod = vn_chmod, 95 .fo_chown = vn_chown, 96 .fo_flags = DFLAG_PASSABLE | DFLAG_SEEKABLE 97 }; 98 99 int 100 vn_open(ndp, flagp, cmode, fp) 101 struct nameidata *ndp; 102 int *flagp, cmode; 103 struct file *fp; 104 { 105 struct thread *td = ndp->ni_cnd.cn_thread; 106 107 return (vn_open_cred(ndp, flagp, cmode, 0, td->td_ucred, fp)); 108 } 109 110 /* 111 * Common code for vnode open operations via a name lookup. 112 * Lookup the vnode and invoke VOP_CREATE if needed. 113 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine. 114 * 115 * Note that this does NOT free nameidata for the successful case, 116 * due to the NDINIT being done elsewhere. 117 */ 118 int 119 vn_open_cred(struct nameidata *ndp, int *flagp, int cmode, u_int vn_open_flags, 120 struct ucred *cred, struct file *fp) 121 { 122 struct vnode *vp; 123 struct mount *mp; 124 struct thread *td = ndp->ni_cnd.cn_thread; 125 struct vattr vat; 126 struct vattr *vap = &vat; 127 int fmode, error; 128 int vfslocked, mpsafe; 129 130 mpsafe = ndp->ni_cnd.cn_flags & MPSAFE; 131 restart: 132 vfslocked = 0; 133 fmode = *flagp; 134 if (fmode & O_CREAT) { 135 ndp->ni_cnd.cn_nameiop = CREATE; 136 ndp->ni_cnd.cn_flags = ISOPEN | LOCKPARENT | LOCKLEAF | 137 MPSAFE; 138 if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0) 139 ndp->ni_cnd.cn_flags |= FOLLOW; 140 if (!(vn_open_flags & VN_OPEN_NOAUDIT)) 141 ndp->ni_cnd.cn_flags |= AUDITVNODE1; 142 bwillwrite(); 143 if ((error = namei(ndp)) != 0) 144 return (error); 145 vfslocked = NDHASGIANT(ndp); 146 if (!mpsafe) 147 ndp->ni_cnd.cn_flags &= ~MPSAFE; 148 if (ndp->ni_vp == NULL) { 149 VATTR_NULL(vap); 150 vap->va_type = VREG; 151 vap->va_mode = cmode; 152 if (fmode & O_EXCL) 153 vap->va_vaflags |= VA_EXCLUSIVE; 154 if (vn_start_write(ndp->ni_dvp, &mp, V_NOWAIT) != 0) { 155 NDFREE(ndp, NDF_ONLY_PNBUF); 156 vput(ndp->ni_dvp); 157 VFS_UNLOCK_GIANT(vfslocked); 158 if ((error = vn_start_write(NULL, &mp, 159 V_XSLEEP | PCATCH)) != 0) 160 return (error); 161 goto restart; 162 } 163 #ifdef MAC 164 error = mac_vnode_check_create(cred, ndp->ni_dvp, 165 &ndp->ni_cnd, vap); 166 if (error == 0) 167 #endif 168 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp, 169 &ndp->ni_cnd, vap); 170 vput(ndp->ni_dvp); 171 vn_finished_write(mp); 172 if (error) { 173 VFS_UNLOCK_GIANT(vfslocked); 174 NDFREE(ndp, NDF_ONLY_PNBUF); 175 return (error); 176 } 177 fmode &= ~O_TRUNC; 178 vp = ndp->ni_vp; 179 } else { 180 if (ndp->ni_dvp == ndp->ni_vp) 181 vrele(ndp->ni_dvp); 182 else 183 vput(ndp->ni_dvp); 184 ndp->ni_dvp = NULL; 185 vp = ndp->ni_vp; 186 if (fmode & O_EXCL) { 187 error = EEXIST; 188 goto bad; 189 } 190 fmode &= ~O_CREAT; 191 } 192 } else { 193 ndp->ni_cnd.cn_nameiop = LOOKUP; 194 ndp->ni_cnd.cn_flags = ISOPEN | 195 ((fmode & O_NOFOLLOW) ? NOFOLLOW : FOLLOW) | 196 LOCKLEAF | MPSAFE; 197 if (!(fmode & FWRITE)) 198 ndp->ni_cnd.cn_flags |= LOCKSHARED; 199 if (!(vn_open_flags & VN_OPEN_NOAUDIT)) 200 ndp->ni_cnd.cn_flags |= AUDITVNODE1; 201 if ((error = namei(ndp)) != 0) 202 return (error); 203 if (!mpsafe) 204 ndp->ni_cnd.cn_flags &= ~MPSAFE; 205 vfslocked = NDHASGIANT(ndp); 206 vp = ndp->ni_vp; 207 } 208 error = vn_open_vnode(vp, fmode, cred, td, fp); 209 if (error) 210 goto bad; 211 *flagp = fmode; 212 if (!mpsafe) 213 VFS_UNLOCK_GIANT(vfslocked); 214 return (0); 215 bad: 216 NDFREE(ndp, NDF_ONLY_PNBUF); 217 vput(vp); 218 VFS_UNLOCK_GIANT(vfslocked); 219 *flagp = fmode; 220 ndp->ni_vp = NULL; 221 return (error); 222 } 223 224 /* 225 * Common code for vnode open operations once a vnode is located. 226 * Check permissions, and call the VOP_OPEN routine. 227 */ 228 int 229 vn_open_vnode(struct vnode *vp, int fmode, struct ucred *cred, 230 struct thread *td, struct file *fp) 231 { 232 struct mount *mp; 233 accmode_t accmode; 234 struct flock lf; 235 int error, have_flock, lock_flags, type; 236 237 VFS_ASSERT_GIANT(vp->v_mount); 238 if (vp->v_type == VLNK) 239 return (EMLINK); 240 if (vp->v_type == VSOCK) 241 return (EOPNOTSUPP); 242 if (vp->v_type != VDIR && fmode & O_DIRECTORY) 243 return (ENOTDIR); 244 accmode = 0; 245 if (fmode & (FWRITE | O_TRUNC)) { 246 if (vp->v_type == VDIR) 247 return (EISDIR); 248 accmode |= VWRITE; 249 } 250 if (fmode & FREAD) 251 accmode |= VREAD; 252 if (fmode & FEXEC) 253 accmode |= VEXEC; 254 if ((fmode & O_APPEND) && (fmode & FWRITE)) 255 accmode |= VAPPEND; 256 #ifdef MAC 257 error = mac_vnode_check_open(cred, vp, accmode); 258 if (error) 259 return (error); 260 #endif 261 if ((fmode & O_CREAT) == 0) { 262 if (accmode & VWRITE) { 263 error = vn_writechk(vp); 264 if (error) 265 return (error); 266 } 267 if (accmode) { 268 error = VOP_ACCESS(vp, accmode, cred, td); 269 if (error) 270 return (error); 271 } 272 } 273 if ((error = VOP_OPEN(vp, fmode, cred, td, fp)) != 0) 274 return (error); 275 276 if (fmode & (O_EXLOCK | O_SHLOCK)) { 277 KASSERT(fp != NULL, ("open with flock requires fp")); 278 lock_flags = VOP_ISLOCKED(vp); 279 VOP_UNLOCK(vp, 0); 280 lf.l_whence = SEEK_SET; 281 lf.l_start = 0; 282 lf.l_len = 0; 283 if (fmode & O_EXLOCK) 284 lf.l_type = F_WRLCK; 285 else 286 lf.l_type = F_RDLCK; 287 type = F_FLOCK; 288 if ((fmode & FNONBLOCK) == 0) 289 type |= F_WAIT; 290 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, type); 291 have_flock = (error == 0); 292 vn_lock(vp, lock_flags | LK_RETRY); 293 if (error == 0 && vp->v_iflag & VI_DOOMED) 294 error = ENOENT; 295 /* 296 * Another thread might have used this vnode as an 297 * executable while the vnode lock was dropped. 298 * Ensure the vnode is still able to be opened for 299 * writing after the lock has been obtained. 300 */ 301 if (error == 0 && accmode & VWRITE) 302 error = vn_writechk(vp); 303 if (error) { 304 VOP_UNLOCK(vp, 0); 305 if (have_flock) { 306 lf.l_whence = SEEK_SET; 307 lf.l_start = 0; 308 lf.l_len = 0; 309 lf.l_type = F_UNLCK; 310 (void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, 311 F_FLOCK); 312 } 313 vn_start_write(vp, &mp, V_WAIT); 314 vn_lock(vp, lock_flags | LK_RETRY); 315 (void)VOP_CLOSE(vp, fmode, cred, td); 316 vn_finished_write(mp); 317 return (error); 318 } 319 fp->f_flag |= FHASLOCK; 320 } 321 if (fmode & FWRITE) { 322 vp->v_writecount++; 323 CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d", 324 __func__, vp, vp->v_writecount); 325 } 326 ASSERT_VOP_LOCKED(vp, "vn_open_vnode"); 327 return (0); 328 } 329 330 /* 331 * Check for write permissions on the specified vnode. 332 * Prototype text segments cannot be written. 333 */ 334 int 335 vn_writechk(vp) 336 register struct vnode *vp; 337 { 338 339 ASSERT_VOP_LOCKED(vp, "vn_writechk"); 340 /* 341 * If there's shared text associated with 342 * the vnode, try to free it up once. If 343 * we fail, we can't allow writing. 344 */ 345 if (vp->v_vflag & VV_TEXT) 346 return (ETXTBSY); 347 348 return (0); 349 } 350 351 /* 352 * Vnode close call 353 */ 354 int 355 vn_close(vp, flags, file_cred, td) 356 register struct vnode *vp; 357 int flags; 358 struct ucred *file_cred; 359 struct thread *td; 360 { 361 struct mount *mp; 362 int error, lock_flags; 363 364 if (!(flags & FWRITE) && vp->v_mount != NULL && 365 vp->v_mount->mnt_kern_flag & MNTK_EXTENDED_SHARED) 366 lock_flags = LK_SHARED; 367 else 368 lock_flags = LK_EXCLUSIVE; 369 370 VFS_ASSERT_GIANT(vp->v_mount); 371 372 vn_start_write(vp, &mp, V_WAIT); 373 vn_lock(vp, lock_flags | LK_RETRY); 374 if (flags & FWRITE) { 375 VNASSERT(vp->v_writecount > 0, vp, 376 ("vn_close: negative writecount")); 377 vp->v_writecount--; 378 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d", 379 __func__, vp, vp->v_writecount); 380 } 381 error = VOP_CLOSE(vp, flags, file_cred, td); 382 vput(vp); 383 vn_finished_write(mp); 384 return (error); 385 } 386 387 /* 388 * Heuristic to detect sequential operation. 389 */ 390 static int 391 sequential_heuristic(struct uio *uio, struct file *fp) 392 { 393 394 if (atomic_load_acq_int(&(fp->f_flag)) & FRDAHEAD) 395 return (fp->f_seqcount << IO_SEQSHIFT); 396 397 /* 398 * Offset 0 is handled specially. open() sets f_seqcount to 1 so 399 * that the first I/O is normally considered to be slightly 400 * sequential. Seeking to offset 0 doesn't change sequentiality 401 * unless previous seeks have reduced f_seqcount to 0, in which 402 * case offset 0 is not special. 403 */ 404 if ((uio->uio_offset == 0 && fp->f_seqcount > 0) || 405 uio->uio_offset == fp->f_nextoff) { 406 /* 407 * f_seqcount is in units of fixed-size blocks so that it 408 * depends mainly on the amount of sequential I/O and not 409 * much on the number of sequential I/O's. The fixed size 410 * of 16384 is hard-coded here since it is (not quite) just 411 * a magic size that works well here. This size is more 412 * closely related to the best I/O size for real disks than 413 * to any block size used by software. 414 */ 415 fp->f_seqcount += howmany(uio->uio_resid, 16384); 416 if (fp->f_seqcount > IO_SEQMAX) 417 fp->f_seqcount = IO_SEQMAX; 418 return (fp->f_seqcount << IO_SEQSHIFT); 419 } 420 421 /* Not sequential. Quickly draw-down sequentiality. */ 422 if (fp->f_seqcount > 1) 423 fp->f_seqcount = 1; 424 else 425 fp->f_seqcount = 0; 426 return (0); 427 } 428 429 /* 430 * Package up an I/O request on a vnode into a uio and do it. 431 */ 432 int 433 vn_rdwr(enum uio_rw rw, struct vnode *vp, void *base, int len, off_t offset, 434 enum uio_seg segflg, int ioflg, struct ucred *active_cred, 435 struct ucred *file_cred, ssize_t *aresid, struct thread *td) 436 { 437 struct uio auio; 438 struct iovec aiov; 439 struct mount *mp; 440 struct ucred *cred; 441 void *rl_cookie; 442 int error, lock_flags; 443 444 VFS_ASSERT_GIANT(vp->v_mount); 445 446 auio.uio_iov = &aiov; 447 auio.uio_iovcnt = 1; 448 aiov.iov_base = base; 449 aiov.iov_len = len; 450 auio.uio_resid = len; 451 auio.uio_offset = offset; 452 auio.uio_segflg = segflg; 453 auio.uio_rw = rw; 454 auio.uio_td = td; 455 error = 0; 456 457 if ((ioflg & IO_NODELOCKED) == 0) { 458 if (rw == UIO_READ) { 459 rl_cookie = vn_rangelock_rlock(vp, offset, 460 offset + len); 461 } else { 462 rl_cookie = vn_rangelock_wlock(vp, offset, 463 offset + len); 464 } 465 mp = NULL; 466 if (rw == UIO_WRITE) { 467 if (vp->v_type != VCHR && 468 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) 469 != 0) 470 goto out; 471 if (MNT_SHARED_WRITES(mp) || 472 ((mp == NULL) && MNT_SHARED_WRITES(vp->v_mount))) 473 lock_flags = LK_SHARED; 474 else 475 lock_flags = LK_EXCLUSIVE; 476 } else 477 lock_flags = LK_SHARED; 478 vn_lock(vp, lock_flags | LK_RETRY); 479 } else 480 rl_cookie = NULL; 481 482 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 483 #ifdef MAC 484 if ((ioflg & IO_NOMACCHECK) == 0) { 485 if (rw == UIO_READ) 486 error = mac_vnode_check_read(active_cred, file_cred, 487 vp); 488 else 489 error = mac_vnode_check_write(active_cred, file_cred, 490 vp); 491 } 492 #endif 493 if (error == 0) { 494 if (file_cred != NULL) 495 cred = file_cred; 496 else 497 cred = active_cred; 498 if (rw == UIO_READ) 499 error = VOP_READ(vp, &auio, ioflg, cred); 500 else 501 error = VOP_WRITE(vp, &auio, ioflg, cred); 502 } 503 if (aresid) 504 *aresid = auio.uio_resid; 505 else 506 if (auio.uio_resid && error == 0) 507 error = EIO; 508 if ((ioflg & IO_NODELOCKED) == 0) { 509 VOP_UNLOCK(vp, 0); 510 if (mp != NULL) 511 vn_finished_write(mp); 512 } 513 out: 514 if (rl_cookie != NULL) 515 vn_rangelock_unlock(vp, rl_cookie); 516 return (error); 517 } 518 519 /* 520 * Package up an I/O request on a vnode into a uio and do it. The I/O 521 * request is split up into smaller chunks and we try to avoid saturating 522 * the buffer cache while potentially holding a vnode locked, so we 523 * check bwillwrite() before calling vn_rdwr(). We also call kern_yield() 524 * to give other processes a chance to lock the vnode (either other processes 525 * core'ing the same binary, or unrelated processes scanning the directory). 526 */ 527 int 528 vn_rdwr_inchunks(rw, vp, base, len, offset, segflg, ioflg, active_cred, 529 file_cred, aresid, td) 530 enum uio_rw rw; 531 struct vnode *vp; 532 void *base; 533 size_t len; 534 off_t offset; 535 enum uio_seg segflg; 536 int ioflg; 537 struct ucred *active_cred; 538 struct ucred *file_cred; 539 size_t *aresid; 540 struct thread *td; 541 { 542 int error = 0; 543 ssize_t iaresid; 544 545 VFS_ASSERT_GIANT(vp->v_mount); 546 547 do { 548 int chunk; 549 550 /* 551 * Force `offset' to a multiple of MAXBSIZE except possibly 552 * for the first chunk, so that filesystems only need to 553 * write full blocks except possibly for the first and last 554 * chunks. 555 */ 556 chunk = MAXBSIZE - (uoff_t)offset % MAXBSIZE; 557 558 if (chunk > len) 559 chunk = len; 560 if (rw != UIO_READ && vp->v_type == VREG) 561 bwillwrite(); 562 iaresid = 0; 563 error = vn_rdwr(rw, vp, base, chunk, offset, segflg, 564 ioflg, active_cred, file_cred, &iaresid, td); 565 len -= chunk; /* aresid calc already includes length */ 566 if (error) 567 break; 568 offset += chunk; 569 base = (char *)base + chunk; 570 kern_yield(PRI_USER); 571 } while (len); 572 if (aresid) 573 *aresid = len + iaresid; 574 return (error); 575 } 576 577 off_t 578 foffset_lock(struct file *fp, int flags) 579 { 580 struct mtx *mtxp; 581 off_t res; 582 583 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed")); 584 585 #if OFF_MAX <= LONG_MAX 586 /* 587 * Caller only wants the current f_offset value. Assume that 588 * the long and shorter integer types reads are atomic. 589 */ 590 if ((flags & FOF_NOLOCK) != 0) 591 return (fp->f_offset); 592 #endif 593 594 /* 595 * According to McKusick the vn lock was protecting f_offset here. 596 * It is now protected by the FOFFSET_LOCKED flag. 597 */ 598 mtxp = mtx_pool_find(mtxpool_sleep, fp); 599 mtx_lock(mtxp); 600 if ((flags & FOF_NOLOCK) == 0) { 601 while (fp->f_vnread_flags & FOFFSET_LOCKED) { 602 fp->f_vnread_flags |= FOFFSET_LOCK_WAITING; 603 msleep(&fp->f_vnread_flags, mtxp, PUSER -1, 604 "vofflock", 0); 605 } 606 fp->f_vnread_flags |= FOFFSET_LOCKED; 607 } 608 res = fp->f_offset; 609 mtx_unlock(mtxp); 610 return (res); 611 } 612 613 void 614 foffset_unlock(struct file *fp, off_t val, int flags) 615 { 616 struct mtx *mtxp; 617 618 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed")); 619 620 #if OFF_MAX <= LONG_MAX 621 if ((flags & FOF_NOLOCK) != 0) { 622 if ((flags & FOF_NOUPDATE) == 0) 623 fp->f_offset = val; 624 if ((flags & FOF_NEXTOFF) != 0) 625 fp->f_nextoff = val; 626 return; 627 } 628 #endif 629 630 mtxp = mtx_pool_find(mtxpool_sleep, fp); 631 mtx_lock(mtxp); 632 if ((flags & FOF_NOUPDATE) == 0) 633 fp->f_offset = val; 634 if ((flags & FOF_NEXTOFF) != 0) 635 fp->f_nextoff = val; 636 if ((flags & FOF_NOLOCK) == 0) { 637 KASSERT((fp->f_vnread_flags & FOFFSET_LOCKED) != 0, 638 ("Lost FOFFSET_LOCKED")); 639 if (fp->f_vnread_flags & FOFFSET_LOCK_WAITING) 640 wakeup(&fp->f_vnread_flags); 641 fp->f_vnread_flags = 0; 642 } 643 mtx_unlock(mtxp); 644 } 645 646 void 647 foffset_lock_uio(struct file *fp, struct uio *uio, int flags) 648 { 649 650 if ((flags & FOF_OFFSET) == 0) 651 uio->uio_offset = foffset_lock(fp, flags); 652 } 653 654 void 655 foffset_unlock_uio(struct file *fp, struct uio *uio, int flags) 656 { 657 658 if ((flags & FOF_OFFSET) == 0) 659 foffset_unlock(fp, uio->uio_offset, flags); 660 } 661 662 static int 663 get_advice(struct file *fp, struct uio *uio) 664 { 665 struct mtx *mtxp; 666 int ret; 667 668 ret = POSIX_FADV_NORMAL; 669 if (fp->f_advice == NULL) 670 return (ret); 671 672 mtxp = mtx_pool_find(mtxpool_sleep, fp); 673 mtx_lock(mtxp); 674 if (uio->uio_offset >= fp->f_advice->fa_start && 675 uio->uio_offset + uio->uio_resid <= fp->f_advice->fa_end) 676 ret = fp->f_advice->fa_advice; 677 mtx_unlock(mtxp); 678 return (ret); 679 } 680 681 /* 682 * File table vnode read routine. 683 */ 684 static int 685 vn_read(fp, uio, active_cred, flags, td) 686 struct file *fp; 687 struct uio *uio; 688 struct ucred *active_cred; 689 int flags; 690 struct thread *td; 691 { 692 struct vnode *vp; 693 struct mtx *mtxp; 694 int error, ioflag; 695 int advice, vfslocked; 696 off_t offset, start, end; 697 698 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", 699 uio->uio_td, td)); 700 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET")); 701 vp = fp->f_vnode; 702 ioflag = 0; 703 if (fp->f_flag & FNONBLOCK) 704 ioflag |= IO_NDELAY; 705 if (fp->f_flag & O_DIRECT) 706 ioflag |= IO_DIRECT; 707 advice = get_advice(fp, uio); 708 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 709 vn_lock(vp, LK_SHARED | LK_RETRY); 710 711 switch (advice) { 712 case POSIX_FADV_NORMAL: 713 case POSIX_FADV_SEQUENTIAL: 714 case POSIX_FADV_NOREUSE: 715 ioflag |= sequential_heuristic(uio, fp); 716 break; 717 case POSIX_FADV_RANDOM: 718 /* Disable read-ahead for random I/O. */ 719 break; 720 } 721 offset = uio->uio_offset; 722 723 #ifdef MAC 724 error = mac_vnode_check_read(active_cred, fp->f_cred, vp); 725 if (error == 0) 726 #endif 727 error = VOP_READ(vp, uio, ioflag, fp->f_cred); 728 fp->f_nextoff = uio->uio_offset; 729 VOP_UNLOCK(vp, 0); 730 if (error == 0 && advice == POSIX_FADV_NOREUSE && 731 offset != uio->uio_offset) { 732 /* 733 * Use POSIX_FADV_DONTNEED to flush clean pages and 734 * buffers for the backing file after a 735 * POSIX_FADV_NOREUSE read(2). To optimize the common 736 * case of using POSIX_FADV_NOREUSE with sequential 737 * access, track the previous implicit DONTNEED 738 * request and grow this request to include the 739 * current read(2) in addition to the previous 740 * DONTNEED. With purely sequential access this will 741 * cause the DONTNEED requests to continously grow to 742 * cover all of the previously read regions of the 743 * file. This allows filesystem blocks that are 744 * accessed by multiple calls to read(2) to be flushed 745 * once the last read(2) finishes. 746 */ 747 start = offset; 748 end = uio->uio_offset - 1; 749 mtxp = mtx_pool_find(mtxpool_sleep, fp); 750 mtx_lock(mtxp); 751 if (fp->f_advice != NULL && 752 fp->f_advice->fa_advice == POSIX_FADV_NOREUSE) { 753 if (start != 0 && fp->f_advice->fa_prevend + 1 == start) 754 start = fp->f_advice->fa_prevstart; 755 else if (fp->f_advice->fa_prevstart != 0 && 756 fp->f_advice->fa_prevstart == end + 1) 757 end = fp->f_advice->fa_prevend; 758 fp->f_advice->fa_prevstart = start; 759 fp->f_advice->fa_prevend = end; 760 } 761 mtx_unlock(mtxp); 762 error = VOP_ADVISE(vp, start, end, POSIX_FADV_DONTNEED); 763 } 764 VFS_UNLOCK_GIANT(vfslocked); 765 return (error); 766 } 767 768 /* 769 * File table vnode write routine. 770 */ 771 static int 772 vn_write(fp, uio, active_cred, flags, td) 773 struct file *fp; 774 struct uio *uio; 775 struct ucred *active_cred; 776 int flags; 777 struct thread *td; 778 { 779 struct vnode *vp; 780 struct mount *mp; 781 struct mtx *mtxp; 782 int error, ioflag, lock_flags; 783 int advice, vfslocked; 784 off_t offset, start, end; 785 786 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", 787 uio->uio_td, td)); 788 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET")); 789 vp = fp->f_vnode; 790 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 791 if (vp->v_type == VREG) 792 bwillwrite(); 793 ioflag = IO_UNIT; 794 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 795 ioflag |= IO_APPEND; 796 if (fp->f_flag & FNONBLOCK) 797 ioflag |= IO_NDELAY; 798 if (fp->f_flag & O_DIRECT) 799 ioflag |= IO_DIRECT; 800 if ((fp->f_flag & O_FSYNC) || 801 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS))) 802 ioflag |= IO_SYNC; 803 mp = NULL; 804 if (vp->v_type != VCHR && 805 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0) 806 goto unlock; 807 808 advice = get_advice(fp, uio); 809 810 if ((MNT_SHARED_WRITES(mp) || 811 ((mp == NULL) && MNT_SHARED_WRITES(vp->v_mount))) && 812 (flags & FOF_OFFSET) != 0) { 813 lock_flags = LK_SHARED; 814 } else { 815 lock_flags = LK_EXCLUSIVE; 816 } 817 818 vn_lock(vp, lock_flags | LK_RETRY); 819 switch (advice) { 820 case POSIX_FADV_NORMAL: 821 case POSIX_FADV_SEQUENTIAL: 822 case POSIX_FADV_NOREUSE: 823 ioflag |= sequential_heuristic(uio, fp); 824 break; 825 case POSIX_FADV_RANDOM: 826 /* XXX: Is this correct? */ 827 break; 828 } 829 offset = uio->uio_offset; 830 831 #ifdef MAC 832 error = mac_vnode_check_write(active_cred, fp->f_cred, vp); 833 if (error == 0) 834 #endif 835 error = VOP_WRITE(vp, uio, ioflag, fp->f_cred); 836 fp->f_nextoff = uio->uio_offset; 837 VOP_UNLOCK(vp, 0); 838 if (vp->v_type != VCHR) 839 vn_finished_write(mp); 840 if (error == 0 && advice == POSIX_FADV_NOREUSE && 841 offset != uio->uio_offset) { 842 /* 843 * Use POSIX_FADV_DONTNEED to flush clean pages and 844 * buffers for the backing file after a 845 * POSIX_FADV_NOREUSE write(2). To optimize the 846 * common case of using POSIX_FADV_NOREUSE with 847 * sequential access, track the previous implicit 848 * DONTNEED request and grow this request to include 849 * the current write(2) in addition to the previous 850 * DONTNEED. With purely sequential access this will 851 * cause the DONTNEED requests to continously grow to 852 * cover all of the previously written regions of the 853 * file. 854 * 855 * Note that the blocks just written are almost 856 * certainly still dirty, so this only works when 857 * VOP_ADVISE() calls from subsequent writes push out 858 * the data written by this write(2) once the backing 859 * buffers are clean. However, as compared to forcing 860 * IO_DIRECT, this gives much saner behavior. Write 861 * clustering is still allowed, and clean pages are 862 * merely moved to the cache page queue rather than 863 * outright thrown away. This means a subsequent 864 * read(2) can still avoid hitting the disk if the 865 * pages have not been reclaimed. 866 * 867 * This does make POSIX_FADV_NOREUSE largely useless 868 * with non-sequential access. However, sequential 869 * access is the more common use case and the flag is 870 * merely advisory. 871 */ 872 start = offset; 873 end = uio->uio_offset - 1; 874 mtxp = mtx_pool_find(mtxpool_sleep, fp); 875 mtx_lock(mtxp); 876 if (fp->f_advice != NULL && 877 fp->f_advice->fa_advice == POSIX_FADV_NOREUSE) { 878 if (start != 0 && fp->f_advice->fa_prevend + 1 == start) 879 start = fp->f_advice->fa_prevstart; 880 else if (fp->f_advice->fa_prevstart != 0 && 881 fp->f_advice->fa_prevstart == end + 1) 882 end = fp->f_advice->fa_prevend; 883 fp->f_advice->fa_prevstart = start; 884 fp->f_advice->fa_prevend = end; 885 } 886 mtx_unlock(mtxp); 887 error = VOP_ADVISE(vp, start, end, POSIX_FADV_DONTNEED); 888 } 889 890 unlock: 891 VFS_UNLOCK_GIANT(vfslocked); 892 return (error); 893 } 894 895 static const int io_hold_cnt = 16; 896 static int vn_io_fault_enable = 1; 897 SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_enable, CTLFLAG_RW, 898 &vn_io_fault_enable, 0, "Enable vn_io_fault lock avoidance"); 899 static unsigned long vn_io_faults_cnt; 900 SYSCTL_LONG(_debug, OID_AUTO, vn_io_faults, CTLFLAG_RD, 901 &vn_io_faults_cnt, 0, "Count of vn_io_fault lock avoidance triggers"); 902 903 /* 904 * The vn_io_fault() is a wrapper around vn_read() and vn_write() to 905 * prevent the following deadlock: 906 * 907 * Assume that the thread A reads from the vnode vp1 into userspace 908 * buffer buf1 backed by the pages of vnode vp2. If a page in buf1 is 909 * currently not resident, then system ends up with the call chain 910 * vn_read() -> VOP_READ(vp1) -> uiomove() -> [Page Fault] -> 911 * vm_fault(buf1) -> vnode_pager_getpages(vp2) -> VOP_GETPAGES(vp2) 912 * which establishes lock order vp1->vn_lock, then vp2->vn_lock. 913 * If, at the same time, thread B reads from vnode vp2 into buffer buf2 914 * backed by the pages of vnode vp1, and some page in buf2 is not 915 * resident, we get a reversed order vp2->vn_lock, then vp1->vn_lock. 916 * 917 * To prevent the lock order reversal and deadlock, vn_io_fault() does 918 * not allow page faults to happen during VOP_READ() or VOP_WRITE(). 919 * Instead, it first tries to do the whole range i/o with pagefaults 920 * disabled. If all pages in the i/o buffer are resident and mapped, 921 * VOP will succeed (ignoring the genuine filesystem errors). 922 * Otherwise, we get back EFAULT, and vn_io_fault() falls back to do 923 * i/o in chunks, with all pages in the chunk prefaulted and held 924 * using vm_fault_quick_hold_pages(). 925 * 926 * Filesystems using this deadlock avoidance scheme should use the 927 * array of the held pages from uio, saved in the curthread->td_ma, 928 * instead of doing uiomove(). A helper function 929 * vn_io_fault_uiomove() converts uiomove request into 930 * uiomove_fromphys() over td_ma array. 931 * 932 * Since vnode locks do not cover the whole i/o anymore, rangelocks 933 * make the current i/o request atomic with respect to other i/os and 934 * truncations. 935 */ 936 static int 937 vn_io_fault(struct file *fp, struct uio *uio, struct ucred *active_cred, 938 int flags, struct thread *td) 939 { 940 vm_page_t ma[io_hold_cnt + 2]; 941 struct uio *uio_clone, short_uio; 942 struct iovec short_iovec[1]; 943 fo_rdwr_t *doio; 944 struct vnode *vp; 945 void *rl_cookie; 946 struct mount *mp; 947 vm_page_t *prev_td_ma; 948 int cnt, error, save, saveheld, prev_td_ma_cnt; 949 vm_offset_t addr, end; 950 vm_prot_t prot; 951 size_t len, resid; 952 ssize_t adv; 953 954 if (uio->uio_rw == UIO_READ) 955 doio = vn_read; 956 else 957 doio = vn_write; 958 vp = fp->f_vnode; 959 foffset_lock_uio(fp, uio, flags); 960 961 if (uio->uio_segflg != UIO_USERSPACE || vp->v_type != VREG || 962 ((mp = vp->v_mount) != NULL && 963 (mp->mnt_kern_flag & MNTK_NO_IOPF) == 0) || 964 !vn_io_fault_enable) { 965 error = doio(fp, uio, active_cred, flags | FOF_OFFSET, td); 966 goto out_last; 967 } 968 969 /* 970 * The UFS follows IO_UNIT directive and replays back both 971 * uio_offset and uio_resid if an error is encountered during the 972 * operation. But, since the iovec may be already advanced, 973 * uio is still in an inconsistent state. 974 * 975 * Cache a copy of the original uio, which is advanced to the redo 976 * point using UIO_NOCOPY below. 977 */ 978 uio_clone = cloneuio(uio); 979 resid = uio->uio_resid; 980 981 short_uio.uio_segflg = UIO_USERSPACE; 982 short_uio.uio_rw = uio->uio_rw; 983 short_uio.uio_td = uio->uio_td; 984 985 if (uio->uio_rw == UIO_READ) { 986 prot = VM_PROT_WRITE; 987 rl_cookie = vn_rangelock_rlock(vp, uio->uio_offset, 988 uio->uio_offset + uio->uio_resid); 989 } else { 990 prot = VM_PROT_READ; 991 if ((fp->f_flag & O_APPEND) != 0 || (flags & FOF_OFFSET) == 0) 992 /* For appenders, punt and lock the whole range. */ 993 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 994 else 995 rl_cookie = vn_rangelock_wlock(vp, uio->uio_offset, 996 uio->uio_offset + uio->uio_resid); 997 } 998 999 save = vm_fault_disable_pagefaults(); 1000 error = doio(fp, uio, active_cred, flags | FOF_OFFSET, td); 1001 if (error != EFAULT) 1002 goto out; 1003 1004 atomic_add_long(&vn_io_faults_cnt, 1); 1005 uio_clone->uio_segflg = UIO_NOCOPY; 1006 uiomove(NULL, resid - uio->uio_resid, uio_clone); 1007 uio_clone->uio_segflg = uio->uio_segflg; 1008 1009 saveheld = curthread_pflags_set(TDP_UIOHELD); 1010 prev_td_ma = td->td_ma; 1011 prev_td_ma_cnt = td->td_ma_cnt; 1012 1013 while (uio_clone->uio_resid != 0) { 1014 len = uio_clone->uio_iov->iov_len; 1015 if (len == 0) { 1016 KASSERT(uio_clone->uio_iovcnt >= 1, 1017 ("iovcnt underflow")); 1018 uio_clone->uio_iov++; 1019 uio_clone->uio_iovcnt--; 1020 continue; 1021 } 1022 1023 addr = (vm_offset_t)uio_clone->uio_iov->iov_base; 1024 end = round_page(addr + len); 1025 cnt = howmany(end - trunc_page(addr), PAGE_SIZE); 1026 /* 1027 * A perfectly misaligned address and length could cause 1028 * both the start and the end of the chunk to use partial 1029 * page. +2 accounts for such a situation. 1030 */ 1031 if (cnt > io_hold_cnt + 2) { 1032 len = io_hold_cnt * PAGE_SIZE; 1033 KASSERT(howmany(round_page(addr + len) - 1034 trunc_page(addr), PAGE_SIZE) <= io_hold_cnt + 2, 1035 ("cnt overflow")); 1036 } 1037 cnt = vm_fault_quick_hold_pages(&td->td_proc->p_vmspace->vm_map, 1038 addr, len, prot, ma, io_hold_cnt + 2); 1039 if (cnt == -1) { 1040 error = EFAULT; 1041 break; 1042 } 1043 short_uio.uio_iov = &short_iovec[0]; 1044 short_iovec[0].iov_base = (void *)addr; 1045 short_uio.uio_iovcnt = 1; 1046 short_uio.uio_resid = short_iovec[0].iov_len = len; 1047 short_uio.uio_offset = uio_clone->uio_offset; 1048 td->td_ma = ma; 1049 td->td_ma_cnt = cnt; 1050 1051 error = doio(fp, &short_uio, active_cred, flags | FOF_OFFSET, 1052 td); 1053 vm_page_unhold_pages(ma, cnt); 1054 adv = len - short_uio.uio_resid; 1055 1056 uio_clone->uio_iov->iov_base = 1057 (char *)uio_clone->uio_iov->iov_base + adv; 1058 uio_clone->uio_iov->iov_len -= adv; 1059 uio_clone->uio_resid -= adv; 1060 uio_clone->uio_offset += adv; 1061 1062 uio->uio_resid -= adv; 1063 uio->uio_offset += adv; 1064 1065 if (error != 0 || adv == 0) 1066 break; 1067 } 1068 td->td_ma = prev_td_ma; 1069 td->td_ma_cnt = prev_td_ma_cnt; 1070 curthread_pflags_restore(saveheld); 1071 out: 1072 vm_fault_enable_pagefaults(save); 1073 vn_rangelock_unlock(vp, rl_cookie); 1074 free(uio_clone, M_IOV); 1075 out_last: 1076 foffset_unlock_uio(fp, uio, flags); 1077 return (error); 1078 } 1079 1080 /* 1081 * Helper function to perform the requested uiomove operation using 1082 * the held pages for io->uio_iov[0].iov_base buffer instead of 1083 * copyin/copyout. Access to the pages with uiomove_fromphys() 1084 * instead of iov_base prevents page faults that could occur due to 1085 * pmap_collect() invalidating the mapping created by 1086 * vm_fault_quick_hold_pages(), or pageout daemon, page laundry or 1087 * object cleanup revoking the write access from page mappings. 1088 * 1089 * Filesystems specified MNTK_NO_IOPF shall use vn_io_fault_uiomove() 1090 * instead of plain uiomove(). 1091 */ 1092 int 1093 vn_io_fault_uiomove(char *data, int xfersize, struct uio *uio) 1094 { 1095 struct uio transp_uio; 1096 struct iovec transp_iov[1]; 1097 struct thread *td; 1098 size_t adv; 1099 int error, pgadv; 1100 1101 td = curthread; 1102 if ((td->td_pflags & TDP_UIOHELD) == 0 || 1103 uio->uio_segflg != UIO_USERSPACE) 1104 return (uiomove(data, xfersize, uio)); 1105 1106 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt)); 1107 transp_iov[0].iov_base = data; 1108 transp_uio.uio_iov = &transp_iov[0]; 1109 transp_uio.uio_iovcnt = 1; 1110 if (xfersize > uio->uio_resid) 1111 xfersize = uio->uio_resid; 1112 transp_uio.uio_resid = transp_iov[0].iov_len = xfersize; 1113 transp_uio.uio_offset = 0; 1114 transp_uio.uio_segflg = UIO_SYSSPACE; 1115 /* 1116 * Since transp_iov points to data, and td_ma page array 1117 * corresponds to original uio->uio_iov, we need to invert the 1118 * direction of the i/o operation as passed to 1119 * uiomove_fromphys(). 1120 */ 1121 switch (uio->uio_rw) { 1122 case UIO_WRITE: 1123 transp_uio.uio_rw = UIO_READ; 1124 break; 1125 case UIO_READ: 1126 transp_uio.uio_rw = UIO_WRITE; 1127 break; 1128 } 1129 transp_uio.uio_td = uio->uio_td; 1130 error = uiomove_fromphys(td->td_ma, 1131 ((vm_offset_t)uio->uio_iov->iov_base) & PAGE_MASK, 1132 xfersize, &transp_uio); 1133 adv = xfersize - transp_uio.uio_resid; 1134 pgadv = 1135 (((vm_offset_t)uio->uio_iov->iov_base + adv) >> PAGE_SHIFT) - 1136 (((vm_offset_t)uio->uio_iov->iov_base) >> PAGE_SHIFT); 1137 td->td_ma += pgadv; 1138 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt, 1139 pgadv)); 1140 td->td_ma_cnt -= pgadv; 1141 uio->uio_iov->iov_base = (char *)uio->uio_iov->iov_base + adv; 1142 uio->uio_iov->iov_len -= adv; 1143 uio->uio_resid -= adv; 1144 uio->uio_offset += adv; 1145 return (error); 1146 } 1147 1148 /* 1149 * File table truncate routine. 1150 */ 1151 static int 1152 vn_truncate(struct file *fp, off_t length, struct ucred *active_cred, 1153 struct thread *td) 1154 { 1155 struct vattr vattr; 1156 struct mount *mp; 1157 struct vnode *vp; 1158 void *rl_cookie; 1159 int vfslocked; 1160 int error; 1161 1162 vp = fp->f_vnode; 1163 1164 /* 1165 * Lock the whole range for truncation. Otherwise split i/o 1166 * might happen partly before and partly after the truncation. 1167 */ 1168 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 1169 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 1170 error = vn_start_write(vp, &mp, V_WAIT | PCATCH); 1171 if (error) 1172 goto out1; 1173 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1174 if (vp->v_type == VDIR) { 1175 error = EISDIR; 1176 goto out; 1177 } 1178 #ifdef MAC 1179 error = mac_vnode_check_write(active_cred, fp->f_cred, vp); 1180 if (error) 1181 goto out; 1182 #endif 1183 error = vn_writechk(vp); 1184 if (error == 0) { 1185 VATTR_NULL(&vattr); 1186 vattr.va_size = length; 1187 error = VOP_SETATTR(vp, &vattr, fp->f_cred); 1188 } 1189 out: 1190 VOP_UNLOCK(vp, 0); 1191 vn_finished_write(mp); 1192 out1: 1193 VFS_UNLOCK_GIANT(vfslocked); 1194 vn_rangelock_unlock(vp, rl_cookie); 1195 return (error); 1196 } 1197 1198 /* 1199 * File table vnode stat routine. 1200 */ 1201 static int 1202 vn_statfile(fp, sb, active_cred, td) 1203 struct file *fp; 1204 struct stat *sb; 1205 struct ucred *active_cred; 1206 struct thread *td; 1207 { 1208 struct vnode *vp = fp->f_vnode; 1209 int vfslocked; 1210 int error; 1211 1212 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 1213 vn_lock(vp, LK_SHARED | LK_RETRY); 1214 error = vn_stat(vp, sb, active_cred, fp->f_cred, td); 1215 VOP_UNLOCK(vp, 0); 1216 VFS_UNLOCK_GIANT(vfslocked); 1217 1218 return (error); 1219 } 1220 1221 /* 1222 * Stat a vnode; implementation for the stat syscall 1223 */ 1224 int 1225 vn_stat(vp, sb, active_cred, file_cred, td) 1226 struct vnode *vp; 1227 register struct stat *sb; 1228 struct ucred *active_cred; 1229 struct ucred *file_cred; 1230 struct thread *td; 1231 { 1232 struct vattr vattr; 1233 register struct vattr *vap; 1234 int error; 1235 u_short mode; 1236 1237 #ifdef MAC 1238 error = mac_vnode_check_stat(active_cred, file_cred, vp); 1239 if (error) 1240 return (error); 1241 #endif 1242 1243 vap = &vattr; 1244 1245 /* 1246 * Initialize defaults for new and unusual fields, so that file 1247 * systems which don't support these fields don't need to know 1248 * about them. 1249 */ 1250 vap->va_birthtime.tv_sec = -1; 1251 vap->va_birthtime.tv_nsec = 0; 1252 vap->va_fsid = VNOVAL; 1253 vap->va_rdev = NODEV; 1254 1255 error = VOP_GETATTR(vp, vap, active_cred); 1256 if (error) 1257 return (error); 1258 1259 /* 1260 * Zero the spare stat fields 1261 */ 1262 bzero(sb, sizeof *sb); 1263 1264 /* 1265 * Copy from vattr table 1266 */ 1267 if (vap->va_fsid != VNOVAL) 1268 sb->st_dev = vap->va_fsid; 1269 else 1270 sb->st_dev = vp->v_mount->mnt_stat.f_fsid.val[0]; 1271 sb->st_ino = vap->va_fileid; 1272 mode = vap->va_mode; 1273 switch (vap->va_type) { 1274 case VREG: 1275 mode |= S_IFREG; 1276 break; 1277 case VDIR: 1278 mode |= S_IFDIR; 1279 break; 1280 case VBLK: 1281 mode |= S_IFBLK; 1282 break; 1283 case VCHR: 1284 mode |= S_IFCHR; 1285 break; 1286 case VLNK: 1287 mode |= S_IFLNK; 1288 break; 1289 case VSOCK: 1290 mode |= S_IFSOCK; 1291 break; 1292 case VFIFO: 1293 mode |= S_IFIFO; 1294 break; 1295 default: 1296 return (EBADF); 1297 }; 1298 sb->st_mode = mode; 1299 sb->st_nlink = vap->va_nlink; 1300 sb->st_uid = vap->va_uid; 1301 sb->st_gid = vap->va_gid; 1302 sb->st_rdev = vap->va_rdev; 1303 if (vap->va_size > OFF_MAX) 1304 return (EOVERFLOW); 1305 sb->st_size = vap->va_size; 1306 sb->st_atim = vap->va_atime; 1307 sb->st_mtim = vap->va_mtime; 1308 sb->st_ctim = vap->va_ctime; 1309 sb->st_birthtim = vap->va_birthtime; 1310 1311 /* 1312 * According to www.opengroup.org, the meaning of st_blksize is 1313 * "a filesystem-specific preferred I/O block size for this 1314 * object. In some filesystem types, this may vary from file 1315 * to file" 1316 * Use miminum/default of PAGE_SIZE (e.g. for VCHR). 1317 */ 1318 1319 sb->st_blksize = max(PAGE_SIZE, vap->va_blocksize); 1320 1321 sb->st_flags = vap->va_flags; 1322 if (priv_check(td, PRIV_VFS_GENERATION)) 1323 sb->st_gen = 0; 1324 else 1325 sb->st_gen = vap->va_gen; 1326 1327 sb->st_blocks = vap->va_bytes / S_BLKSIZE; 1328 return (0); 1329 } 1330 1331 /* 1332 * File table vnode ioctl routine. 1333 */ 1334 static int 1335 vn_ioctl(fp, com, data, active_cred, td) 1336 struct file *fp; 1337 u_long com; 1338 void *data; 1339 struct ucred *active_cred; 1340 struct thread *td; 1341 { 1342 struct vnode *vp = fp->f_vnode; 1343 struct vattr vattr; 1344 int vfslocked; 1345 int error; 1346 1347 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 1348 error = ENOTTY; 1349 switch (vp->v_type) { 1350 case VREG: 1351 case VDIR: 1352 if (com == FIONREAD) { 1353 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1354 error = VOP_GETATTR(vp, &vattr, active_cred); 1355 VOP_UNLOCK(vp, 0); 1356 if (!error) 1357 *(int *)data = vattr.va_size - fp->f_offset; 1358 } 1359 if (com == FIONBIO || com == FIOASYNC) /* XXX */ 1360 error = 0; 1361 else 1362 error = VOP_IOCTL(vp, com, data, fp->f_flag, 1363 active_cred, td); 1364 break; 1365 1366 default: 1367 break; 1368 } 1369 VFS_UNLOCK_GIANT(vfslocked); 1370 return (error); 1371 } 1372 1373 /* 1374 * File table vnode poll routine. 1375 */ 1376 static int 1377 vn_poll(fp, events, active_cred, td) 1378 struct file *fp; 1379 int events; 1380 struct ucred *active_cred; 1381 struct thread *td; 1382 { 1383 struct vnode *vp; 1384 int vfslocked; 1385 int error; 1386 1387 vp = fp->f_vnode; 1388 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 1389 #ifdef MAC 1390 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1391 error = mac_vnode_check_poll(active_cred, fp->f_cred, vp); 1392 VOP_UNLOCK(vp, 0); 1393 if (!error) 1394 #endif 1395 1396 error = VOP_POLL(vp, events, fp->f_cred, td); 1397 VFS_UNLOCK_GIANT(vfslocked); 1398 return (error); 1399 } 1400 1401 /* 1402 * Acquire the requested lock and then check for validity. LK_RETRY 1403 * permits vn_lock to return doomed vnodes. 1404 */ 1405 int 1406 _vn_lock(struct vnode *vp, int flags, char *file, int line) 1407 { 1408 int error; 1409 1410 VNASSERT((flags & LK_TYPE_MASK) != 0, vp, 1411 ("vn_lock called with no locktype.")); 1412 do { 1413 #ifdef DEBUG_VFS_LOCKS 1414 KASSERT(vp->v_holdcnt != 0, 1415 ("vn_lock %p: zero hold count", vp)); 1416 #endif 1417 error = VOP_LOCK1(vp, flags, file, line); 1418 flags &= ~LK_INTERLOCK; /* Interlock is always dropped. */ 1419 KASSERT((flags & LK_RETRY) == 0 || error == 0, 1420 ("LK_RETRY set with incompatible flags (0x%x) or an error occured (%d)", 1421 flags, error)); 1422 /* 1423 * Callers specify LK_RETRY if they wish to get dead vnodes. 1424 * If RETRY is not set, we return ENOENT instead. 1425 */ 1426 if (error == 0 && vp->v_iflag & VI_DOOMED && 1427 (flags & LK_RETRY) == 0) { 1428 VOP_UNLOCK(vp, 0); 1429 error = ENOENT; 1430 break; 1431 } 1432 } while (flags & LK_RETRY && error != 0); 1433 return (error); 1434 } 1435 1436 /* 1437 * File table vnode close routine. 1438 */ 1439 static int 1440 vn_closefile(fp, td) 1441 struct file *fp; 1442 struct thread *td; 1443 { 1444 struct vnode *vp; 1445 struct flock lf; 1446 int vfslocked; 1447 int error; 1448 1449 vp = fp->f_vnode; 1450 fp->f_ops = &badfileops; 1451 1452 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 1453 if (fp->f_type == DTYPE_VNODE && fp->f_flag & FHASLOCK) 1454 vref(vp); 1455 1456 error = vn_close(vp, fp->f_flag, fp->f_cred, td); 1457 1458 if (fp->f_type == DTYPE_VNODE && fp->f_flag & FHASLOCK) { 1459 lf.l_whence = SEEK_SET; 1460 lf.l_start = 0; 1461 lf.l_len = 0; 1462 lf.l_type = F_UNLCK; 1463 (void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, F_FLOCK); 1464 vrele(vp); 1465 } 1466 VFS_UNLOCK_GIANT(vfslocked); 1467 return (error); 1468 } 1469 1470 /* 1471 * Preparing to start a filesystem write operation. If the operation is 1472 * permitted, then we bump the count of operations in progress and 1473 * proceed. If a suspend request is in progress, we wait until the 1474 * suspension is over, and then proceed. 1475 */ 1476 int 1477 vn_start_write(vp, mpp, flags) 1478 struct vnode *vp; 1479 struct mount **mpp; 1480 int flags; 1481 { 1482 struct mount *mp; 1483 int error; 1484 1485 error = 0; 1486 /* 1487 * If a vnode is provided, get and return the mount point that 1488 * to which it will write. 1489 */ 1490 if (vp != NULL) { 1491 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) { 1492 *mpp = NULL; 1493 if (error != EOPNOTSUPP) 1494 return (error); 1495 return (0); 1496 } 1497 } 1498 if ((mp = *mpp) == NULL) 1499 return (0); 1500 1501 /* 1502 * VOP_GETWRITEMOUNT() returns with the mp refcount held through 1503 * a vfs_ref(). 1504 * As long as a vnode is not provided we need to acquire a 1505 * refcount for the provided mountpoint too, in order to 1506 * emulate a vfs_ref(). 1507 */ 1508 MNT_ILOCK(mp); 1509 if (vp == NULL) 1510 MNT_REF(mp); 1511 1512 /* 1513 * Check on status of suspension. 1514 */ 1515 if ((curthread->td_pflags & TDP_IGNSUSP) == 0 || 1516 mp->mnt_susp_owner != curthread) { 1517 while ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { 1518 if (flags & V_NOWAIT) { 1519 error = EWOULDBLOCK; 1520 goto unlock; 1521 } 1522 error = msleep(&mp->mnt_flag, MNT_MTX(mp), 1523 (PUSER - 1) | (flags & PCATCH), "suspfs", 0); 1524 if (error) 1525 goto unlock; 1526 } 1527 } 1528 if (flags & V_XSLEEP) 1529 goto unlock; 1530 mp->mnt_writeopcount++; 1531 unlock: 1532 if (error != 0 || (flags & V_XSLEEP) != 0) 1533 MNT_REL(mp); 1534 MNT_IUNLOCK(mp); 1535 return (error); 1536 } 1537 1538 /* 1539 * Secondary suspension. Used by operations such as vop_inactive 1540 * routines that are needed by the higher level functions. These 1541 * are allowed to proceed until all the higher level functions have 1542 * completed (indicated by mnt_writeopcount dropping to zero). At that 1543 * time, these operations are halted until the suspension is over. 1544 */ 1545 int 1546 vn_start_secondary_write(vp, mpp, flags) 1547 struct vnode *vp; 1548 struct mount **mpp; 1549 int flags; 1550 { 1551 struct mount *mp; 1552 int error; 1553 1554 retry: 1555 if (vp != NULL) { 1556 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) { 1557 *mpp = NULL; 1558 if (error != EOPNOTSUPP) 1559 return (error); 1560 return (0); 1561 } 1562 } 1563 /* 1564 * If we are not suspended or have not yet reached suspended 1565 * mode, then let the operation proceed. 1566 */ 1567 if ((mp = *mpp) == NULL) 1568 return (0); 1569 1570 /* 1571 * VOP_GETWRITEMOUNT() returns with the mp refcount held through 1572 * a vfs_ref(). 1573 * As long as a vnode is not provided we need to acquire a 1574 * refcount for the provided mountpoint too, in order to 1575 * emulate a vfs_ref(). 1576 */ 1577 MNT_ILOCK(mp); 1578 if (vp == NULL) 1579 MNT_REF(mp); 1580 if ((mp->mnt_kern_flag & (MNTK_SUSPENDED | MNTK_SUSPEND2)) == 0) { 1581 mp->mnt_secondary_writes++; 1582 mp->mnt_secondary_accwrites++; 1583 MNT_IUNLOCK(mp); 1584 return (0); 1585 } 1586 if (flags & V_NOWAIT) { 1587 MNT_REL(mp); 1588 MNT_IUNLOCK(mp); 1589 return (EWOULDBLOCK); 1590 } 1591 /* 1592 * Wait for the suspension to finish. 1593 */ 1594 error = msleep(&mp->mnt_flag, MNT_MTX(mp), 1595 (PUSER - 1) | (flags & PCATCH) | PDROP, "suspfs", 0); 1596 vfs_rel(mp); 1597 if (error == 0) 1598 goto retry; 1599 return (error); 1600 } 1601 1602 /* 1603 * Filesystem write operation has completed. If we are suspending and this 1604 * operation is the last one, notify the suspender that the suspension is 1605 * now in effect. 1606 */ 1607 void 1608 vn_finished_write(mp) 1609 struct mount *mp; 1610 { 1611 if (mp == NULL) 1612 return; 1613 MNT_ILOCK(mp); 1614 MNT_REL(mp); 1615 mp->mnt_writeopcount--; 1616 if (mp->mnt_writeopcount < 0) 1617 panic("vn_finished_write: neg cnt"); 1618 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && 1619 mp->mnt_writeopcount <= 0) 1620 wakeup(&mp->mnt_writeopcount); 1621 MNT_IUNLOCK(mp); 1622 } 1623 1624 1625 /* 1626 * Filesystem secondary write operation has completed. If we are 1627 * suspending and this operation is the last one, notify the suspender 1628 * that the suspension is now in effect. 1629 */ 1630 void 1631 vn_finished_secondary_write(mp) 1632 struct mount *mp; 1633 { 1634 if (mp == NULL) 1635 return; 1636 MNT_ILOCK(mp); 1637 MNT_REL(mp); 1638 mp->mnt_secondary_writes--; 1639 if (mp->mnt_secondary_writes < 0) 1640 panic("vn_finished_secondary_write: neg cnt"); 1641 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && 1642 mp->mnt_secondary_writes <= 0) 1643 wakeup(&mp->mnt_secondary_writes); 1644 MNT_IUNLOCK(mp); 1645 } 1646 1647 1648 1649 /* 1650 * Request a filesystem to suspend write operations. 1651 */ 1652 int 1653 vfs_write_suspend(mp) 1654 struct mount *mp; 1655 { 1656 int error; 1657 1658 MNT_ILOCK(mp); 1659 if (mp->mnt_susp_owner == curthread) { 1660 MNT_IUNLOCK(mp); 1661 return (EALREADY); 1662 } 1663 while (mp->mnt_kern_flag & MNTK_SUSPEND) 1664 msleep(&mp->mnt_flag, MNT_MTX(mp), PUSER - 1, "wsuspfs", 0); 1665 mp->mnt_kern_flag |= MNTK_SUSPEND; 1666 mp->mnt_susp_owner = curthread; 1667 if (mp->mnt_writeopcount > 0) 1668 (void) msleep(&mp->mnt_writeopcount, 1669 MNT_MTX(mp), (PUSER - 1)|PDROP, "suspwt", 0); 1670 else 1671 MNT_IUNLOCK(mp); 1672 if ((error = VFS_SYNC(mp, MNT_SUSPEND)) != 0) 1673 vfs_write_resume(mp); 1674 return (error); 1675 } 1676 1677 /* 1678 * Request a filesystem to resume write operations. 1679 */ 1680 void 1681 vfs_write_resume(mp) 1682 struct mount *mp; 1683 { 1684 1685 MNT_ILOCK(mp); 1686 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { 1687 KASSERT(mp->mnt_susp_owner == curthread, ("mnt_susp_owner")); 1688 mp->mnt_kern_flag &= ~(MNTK_SUSPEND | MNTK_SUSPEND2 | 1689 MNTK_SUSPENDED); 1690 mp->mnt_susp_owner = NULL; 1691 wakeup(&mp->mnt_writeopcount); 1692 wakeup(&mp->mnt_flag); 1693 curthread->td_pflags &= ~TDP_IGNSUSP; 1694 MNT_IUNLOCK(mp); 1695 VFS_SUSP_CLEAN(mp); 1696 } else 1697 MNT_IUNLOCK(mp); 1698 } 1699 1700 /* 1701 * Implement kqueues for files by translating it to vnode operation. 1702 */ 1703 static int 1704 vn_kqfilter(struct file *fp, struct knote *kn) 1705 { 1706 int vfslocked; 1707 int error; 1708 1709 vfslocked = VFS_LOCK_GIANT(fp->f_vnode->v_mount); 1710 error = VOP_KQFILTER(fp->f_vnode, kn); 1711 VFS_UNLOCK_GIANT(vfslocked); 1712 1713 return error; 1714 } 1715 1716 /* 1717 * Simplified in-kernel wrapper calls for extended attribute access. 1718 * Both calls pass in a NULL credential, authorizing as "kernel" access. 1719 * Set IO_NODELOCKED in ioflg if the vnode is already locked. 1720 */ 1721 int 1722 vn_extattr_get(struct vnode *vp, int ioflg, int attrnamespace, 1723 const char *attrname, int *buflen, char *buf, struct thread *td) 1724 { 1725 struct uio auio; 1726 struct iovec iov; 1727 int error; 1728 1729 iov.iov_len = *buflen; 1730 iov.iov_base = buf; 1731 1732 auio.uio_iov = &iov; 1733 auio.uio_iovcnt = 1; 1734 auio.uio_rw = UIO_READ; 1735 auio.uio_segflg = UIO_SYSSPACE; 1736 auio.uio_td = td; 1737 auio.uio_offset = 0; 1738 auio.uio_resid = *buflen; 1739 1740 if ((ioflg & IO_NODELOCKED) == 0) 1741 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1742 1743 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 1744 1745 /* authorize attribute retrieval as kernel */ 1746 error = VOP_GETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, NULL, 1747 td); 1748 1749 if ((ioflg & IO_NODELOCKED) == 0) 1750 VOP_UNLOCK(vp, 0); 1751 1752 if (error == 0) { 1753 *buflen = *buflen - auio.uio_resid; 1754 } 1755 1756 return (error); 1757 } 1758 1759 /* 1760 * XXX failure mode if partially written? 1761 */ 1762 int 1763 vn_extattr_set(struct vnode *vp, int ioflg, int attrnamespace, 1764 const char *attrname, int buflen, char *buf, struct thread *td) 1765 { 1766 struct uio auio; 1767 struct iovec iov; 1768 struct mount *mp; 1769 int error; 1770 1771 iov.iov_len = buflen; 1772 iov.iov_base = buf; 1773 1774 auio.uio_iov = &iov; 1775 auio.uio_iovcnt = 1; 1776 auio.uio_rw = UIO_WRITE; 1777 auio.uio_segflg = UIO_SYSSPACE; 1778 auio.uio_td = td; 1779 auio.uio_offset = 0; 1780 auio.uio_resid = buflen; 1781 1782 if ((ioflg & IO_NODELOCKED) == 0) { 1783 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) 1784 return (error); 1785 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1786 } 1787 1788 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 1789 1790 /* authorize attribute setting as kernel */ 1791 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, td); 1792 1793 if ((ioflg & IO_NODELOCKED) == 0) { 1794 vn_finished_write(mp); 1795 VOP_UNLOCK(vp, 0); 1796 } 1797 1798 return (error); 1799 } 1800 1801 int 1802 vn_extattr_rm(struct vnode *vp, int ioflg, int attrnamespace, 1803 const char *attrname, struct thread *td) 1804 { 1805 struct mount *mp; 1806 int error; 1807 1808 if ((ioflg & IO_NODELOCKED) == 0) { 1809 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) 1810 return (error); 1811 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1812 } 1813 1814 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 1815 1816 /* authorize attribute removal as kernel */ 1817 error = VOP_DELETEEXTATTR(vp, attrnamespace, attrname, NULL, td); 1818 if (error == EOPNOTSUPP) 1819 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, NULL, 1820 NULL, td); 1821 1822 if ((ioflg & IO_NODELOCKED) == 0) { 1823 vn_finished_write(mp); 1824 VOP_UNLOCK(vp, 0); 1825 } 1826 1827 return (error); 1828 } 1829 1830 int 1831 vn_vget_ino(struct vnode *vp, ino_t ino, int lkflags, struct vnode **rvp) 1832 { 1833 struct mount *mp; 1834 int ltype, error; 1835 1836 mp = vp->v_mount; 1837 ltype = VOP_ISLOCKED(vp); 1838 KASSERT(ltype == LK_EXCLUSIVE || ltype == LK_SHARED, 1839 ("vn_vget_ino: vp not locked")); 1840 error = vfs_busy(mp, MBF_NOWAIT); 1841 if (error != 0) { 1842 vfs_ref(mp); 1843 VOP_UNLOCK(vp, 0); 1844 error = vfs_busy(mp, 0); 1845 vn_lock(vp, ltype | LK_RETRY); 1846 vfs_rel(mp); 1847 if (error != 0) 1848 return (ENOENT); 1849 if (vp->v_iflag & VI_DOOMED) { 1850 vfs_unbusy(mp); 1851 return (ENOENT); 1852 } 1853 } 1854 VOP_UNLOCK(vp, 0); 1855 error = VFS_VGET(mp, ino, lkflags, rvp); 1856 vfs_unbusy(mp); 1857 vn_lock(vp, ltype | LK_RETRY); 1858 if (vp->v_iflag & VI_DOOMED) { 1859 if (error == 0) 1860 vput(*rvp); 1861 error = ENOENT; 1862 } 1863 return (error); 1864 } 1865 1866 int 1867 vn_rlimit_fsize(const struct vnode *vp, const struct uio *uio, 1868 const struct thread *td) 1869 { 1870 1871 if (vp->v_type != VREG || td == NULL) 1872 return (0); 1873 PROC_LOCK(td->td_proc); 1874 if ((uoff_t)uio->uio_offset + uio->uio_resid > 1875 lim_cur(td->td_proc, RLIMIT_FSIZE)) { 1876 kern_psignal(td->td_proc, SIGXFSZ); 1877 PROC_UNLOCK(td->td_proc); 1878 return (EFBIG); 1879 } 1880 PROC_UNLOCK(td->td_proc); 1881 return (0); 1882 } 1883 1884 int 1885 vn_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 1886 struct thread *td) 1887 { 1888 struct vnode *vp; 1889 int error, vfslocked; 1890 1891 vp = fp->f_vnode; 1892 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 1893 #ifdef AUDIT 1894 vn_lock(vp, LK_SHARED | LK_RETRY); 1895 AUDIT_ARG_VNODE1(vp); 1896 VOP_UNLOCK(vp, 0); 1897 #endif 1898 error = setfmode(td, active_cred, vp, mode); 1899 VFS_UNLOCK_GIANT(vfslocked); 1900 return (error); 1901 } 1902 1903 int 1904 vn_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 1905 struct thread *td) 1906 { 1907 struct vnode *vp; 1908 int error, vfslocked; 1909 1910 vp = fp->f_vnode; 1911 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 1912 #ifdef AUDIT 1913 vn_lock(vp, LK_SHARED | LK_RETRY); 1914 AUDIT_ARG_VNODE1(vp); 1915 VOP_UNLOCK(vp, 0); 1916 #endif 1917 error = setfown(td, active_cred, vp, uid, gid); 1918 VFS_UNLOCK_GIANT(vfslocked); 1919 return (error); 1920 } 1921 1922 void 1923 vn_pages_remove(struct vnode *vp, vm_pindex_t start, vm_pindex_t end) 1924 { 1925 vm_object_t object; 1926 1927 if ((object = vp->v_object) == NULL) 1928 return; 1929 VM_OBJECT_LOCK(object); 1930 vm_object_page_remove(object, start, end, 0); 1931 VM_OBJECT_UNLOCK(object); 1932 } 1933 1934 int 1935 vn_bmap_seekhole(struct vnode *vp, u_long cmd, off_t *off, struct ucred *cred) 1936 { 1937 struct vattr va; 1938 daddr_t bn, bnp; 1939 uint64_t bsize; 1940 off_t noff; 1941 int error; 1942 1943 KASSERT(cmd == FIOSEEKHOLE || cmd == FIOSEEKDATA, 1944 ("Wrong command %lu", cmd)); 1945 1946 if (vn_lock(vp, LK_SHARED) != 0) 1947 return (EBADF); 1948 if (vp->v_type != VREG) { 1949 error = ENOTTY; 1950 goto unlock; 1951 } 1952 error = VOP_GETATTR(vp, &va, cred); 1953 if (error != 0) 1954 goto unlock; 1955 noff = *off; 1956 if (noff >= va.va_size) { 1957 error = ENXIO; 1958 goto unlock; 1959 } 1960 bsize = vp->v_mount->mnt_stat.f_iosize; 1961 for (bn = noff / bsize; noff < va.va_size; bn++, noff += bsize) { 1962 error = VOP_BMAP(vp, bn, NULL, &bnp, NULL, NULL); 1963 if (error == EOPNOTSUPP) { 1964 error = ENOTTY; 1965 goto unlock; 1966 } 1967 if ((bnp == -1 && cmd == FIOSEEKHOLE) || 1968 (bnp != -1 && cmd == FIOSEEKDATA)) { 1969 noff = bn * bsize; 1970 if (noff < *off) 1971 noff = *off; 1972 goto unlock; 1973 } 1974 } 1975 if (noff > va.va_size) 1976 noff = va.va_size; 1977 /* noff == va.va_size. There is an implicit hole at the end of file. */ 1978 if (cmd == FIOSEEKDATA) 1979 error = ENXIO; 1980 unlock: 1981 VOP_UNLOCK(vp, 0); 1982 if (error == 0) 1983 *off = noff; 1984 return (error); 1985 } 1986