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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 * Copyright (c) 2012 Konstantin Belousov <kib@FreeBSD.org> 11 * Copyright (c) 2013 The FreeBSD Foundation 12 * 13 * Portions of this software were developed by Konstantin Belousov 14 * under sponsorship from the FreeBSD Foundation. 15 * 16 * Redistribution and use in source and binary forms, with or without 17 * modification, are permitted provided that the following conditions 18 * are met: 19 * 1. Redistributions of source code must retain the above copyright 20 * notice, this list of conditions and the following disclaimer. 21 * 2. Redistributions in binary form must reproduce the above copyright 22 * notice, this list of conditions and the following disclaimer in the 23 * documentation and/or other materials provided with the distribution. 24 * 4. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 * 40 * @(#)vfs_vnops.c 8.2 (Berkeley) 1/21/94 41 */ 42 43 #include <sys/cdefs.h> 44 __FBSDID("$FreeBSD: releng/9.2/sys/kern/vfs_vnops.c 251762 2013-06-14 21:56:10Z jhb $"); 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 #include <sys/fcntl.h> 49 #include <sys/file.h> 50 #include <sys/kdb.h> 51 #include <sys/stat.h> 52 #include <sys/priv.h> 53 #include <sys/proc.h> 54 #include <sys/limits.h> 55 #include <sys/lock.h> 56 #include <sys/mount.h> 57 #include <sys/mutex.h> 58 #include <sys/namei.h> 59 #include <sys/vnode.h> 60 #include <sys/bio.h> 61 #include <sys/buf.h> 62 #include <sys/filio.h> 63 #include <sys/resourcevar.h> 64 #include <sys/sx.h> 65 #include <sys/sysctl.h> 66 #include <sys/ttycom.h> 67 #include <sys/conf.h> 68 #include <sys/syslog.h> 69 #include <sys/unistd.h> 70 71 #include <security/audit/audit.h> 72 #include <security/mac/mac_framework.h> 73 74 #include <vm/vm.h> 75 #include <vm/vm_extern.h> 76 #include <vm/pmap.h> 77 #include <vm/vm_map.h> 78 #include <vm/vm_object.h> 79 #include <vm/vm_page.h> 80 81 static fo_rdwr_t vn_read; 82 static fo_rdwr_t vn_write; 83 static fo_rdwr_t vn_io_fault; 84 static fo_truncate_t vn_truncate; 85 static fo_ioctl_t vn_ioctl; 86 static fo_poll_t vn_poll; 87 static fo_kqfilter_t vn_kqfilter; 88 static fo_stat_t vn_statfile; 89 static fo_close_t vn_closefile; 90 91 struct fileops vnops = { 92 .fo_read = vn_io_fault, 93 .fo_write = vn_io_fault, 94 .fo_truncate = vn_truncate, 95 .fo_ioctl = vn_ioctl, 96 .fo_poll = vn_poll, 97 .fo_kqfilter = vn_kqfilter, 98 .fo_stat = vn_statfile, 99 .fo_close = vn_closefile, 100 .fo_chmod = vn_chmod, 101 .fo_chown = vn_chown, 102 .fo_flags = DFLAG_PASSABLE | DFLAG_SEEKABLE 103 }; 104 105 int 106 vn_open(ndp, flagp, cmode, fp) 107 struct nameidata *ndp; 108 int *flagp, cmode; 109 struct file *fp; 110 { 111 struct thread *td = ndp->ni_cnd.cn_thread; 112 113 return (vn_open_cred(ndp, flagp, cmode, 0, td->td_ucred, fp)); 114 } 115 116 /* 117 * Common code for vnode open operations. 118 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine. 119 * 120 * Note that this does NOT free nameidata for the successful case, 121 * due to the NDINIT being done elsewhere. 122 */ 123 int 124 vn_open_cred(struct nameidata *ndp, int *flagp, int cmode, u_int vn_open_flags, 125 struct ucred *cred, struct file *fp) 126 { 127 struct vnode *vp; 128 struct mount *mp; 129 struct thread *td = ndp->ni_cnd.cn_thread; 130 struct vattr vat; 131 struct vattr *vap = &vat; 132 int fmode, error; 133 accmode_t accmode; 134 int vfslocked, mpsafe; 135 136 mpsafe = ndp->ni_cnd.cn_flags & MPSAFE; 137 restart: 138 vfslocked = 0; 139 fmode = *flagp; 140 if (fmode & O_CREAT) { 141 ndp->ni_cnd.cn_nameiop = CREATE; 142 ndp->ni_cnd.cn_flags = ISOPEN | LOCKPARENT | LOCKLEAF | 143 MPSAFE; 144 if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0) 145 ndp->ni_cnd.cn_flags |= FOLLOW; 146 if (!(vn_open_flags & VN_OPEN_NOAUDIT)) 147 ndp->ni_cnd.cn_flags |= AUDITVNODE1; 148 bwillwrite(); 149 if ((error = namei(ndp)) != 0) 150 return (error); 151 vfslocked = NDHASGIANT(ndp); 152 if (!mpsafe) 153 ndp->ni_cnd.cn_flags &= ~MPSAFE; 154 if (ndp->ni_vp == NULL) { 155 VATTR_NULL(vap); 156 vap->va_type = VREG; 157 vap->va_mode = cmode; 158 if (fmode & O_EXCL) 159 vap->va_vaflags |= VA_EXCLUSIVE; 160 if (vn_start_write(ndp->ni_dvp, &mp, V_NOWAIT) != 0) { 161 NDFREE(ndp, NDF_ONLY_PNBUF); 162 vput(ndp->ni_dvp); 163 VFS_UNLOCK_GIANT(vfslocked); 164 if ((error = vn_start_write(NULL, &mp, 165 V_XSLEEP | PCATCH)) != 0) 166 return (error); 167 goto restart; 168 } 169 #ifdef MAC 170 error = mac_vnode_check_create(cred, ndp->ni_dvp, 171 &ndp->ni_cnd, vap); 172 if (error == 0) 173 #endif 174 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp, 175 &ndp->ni_cnd, vap); 176 vput(ndp->ni_dvp); 177 vn_finished_write(mp); 178 if (error) { 179 VFS_UNLOCK_GIANT(vfslocked); 180 NDFREE(ndp, NDF_ONLY_PNBUF); 181 return (error); 182 } 183 fmode &= ~O_TRUNC; 184 vp = ndp->ni_vp; 185 } else { 186 if (ndp->ni_dvp == ndp->ni_vp) 187 vrele(ndp->ni_dvp); 188 else 189 vput(ndp->ni_dvp); 190 ndp->ni_dvp = NULL; 191 vp = ndp->ni_vp; 192 if (fmode & O_EXCL) { 193 error = EEXIST; 194 goto bad; 195 } 196 fmode &= ~O_CREAT; 197 } 198 } else { 199 ndp->ni_cnd.cn_nameiop = LOOKUP; 200 ndp->ni_cnd.cn_flags = ISOPEN | 201 ((fmode & O_NOFOLLOW) ? NOFOLLOW : FOLLOW) | 202 LOCKLEAF | MPSAFE; 203 if (!(fmode & FWRITE)) 204 ndp->ni_cnd.cn_flags |= LOCKSHARED; 205 if (!(vn_open_flags & VN_OPEN_NOAUDIT)) 206 ndp->ni_cnd.cn_flags |= AUDITVNODE1; 207 if ((error = namei(ndp)) != 0) 208 return (error); 209 if (!mpsafe) 210 ndp->ni_cnd.cn_flags &= ~MPSAFE; 211 vfslocked = NDHASGIANT(ndp); 212 vp = ndp->ni_vp; 213 } 214 if (vp->v_type == VLNK) { 215 error = EMLINK; 216 goto bad; 217 } 218 if (vp->v_type == VSOCK) { 219 error = EOPNOTSUPP; 220 goto bad; 221 } 222 if (vp->v_type != VDIR && fmode & O_DIRECTORY) { 223 error = ENOTDIR; 224 goto bad; 225 } 226 accmode = 0; 227 if (fmode & (FWRITE | O_TRUNC)) { 228 if (vp->v_type == VDIR) { 229 error = EISDIR; 230 goto bad; 231 } 232 accmode |= VWRITE; 233 } 234 if (fmode & FREAD) 235 accmode |= VREAD; 236 if (fmode & FEXEC) 237 accmode |= VEXEC; 238 if ((fmode & O_APPEND) && (fmode & FWRITE)) 239 accmode |= VAPPEND; 240 #ifdef MAC 241 error = mac_vnode_check_open(cred, vp, accmode); 242 if (error) 243 goto bad; 244 #endif 245 if ((fmode & O_CREAT) == 0) { 246 if (accmode & VWRITE) { 247 error = vn_writechk(vp); 248 if (error) 249 goto bad; 250 } 251 if (accmode) { 252 error = VOP_ACCESS(vp, accmode, cred, td); 253 if (error) 254 goto bad; 255 } 256 } 257 if ((error = VOP_OPEN(vp, fmode, cred, td, fp)) != 0) 258 goto bad; 259 260 if (fmode & FWRITE) 261 VOP_ADD_WRITECOUNT(vp, 1); 262 *flagp = fmode; 263 ASSERT_VOP_LOCKED(vp, "vn_open_cred"); 264 if (!mpsafe) 265 VFS_UNLOCK_GIANT(vfslocked); 266 return (0); 267 bad: 268 NDFREE(ndp, NDF_ONLY_PNBUF); 269 vput(vp); 270 VFS_UNLOCK_GIANT(vfslocked); 271 *flagp = fmode; 272 ndp->ni_vp = NULL; 273 return (error); 274 } 275 276 /* 277 * Check for write permissions on the specified vnode. 278 * Prototype text segments cannot be written. 279 */ 280 int 281 vn_writechk(vp) 282 register struct vnode *vp; 283 { 284 285 ASSERT_VOP_LOCKED(vp, "vn_writechk"); 286 /* 287 * If there's shared text associated with 288 * the vnode, try to free it up once. If 289 * we fail, we can't allow writing. 290 */ 291 if (VOP_IS_TEXT(vp)) 292 return (ETXTBSY); 293 294 return (0); 295 } 296 297 /* 298 * Vnode close call 299 */ 300 int 301 vn_close(vp, flags, file_cred, td) 302 register struct vnode *vp; 303 int flags; 304 struct ucred *file_cred; 305 struct thread *td; 306 { 307 struct mount *mp; 308 int error, lock_flags; 309 310 if (!(flags & FWRITE) && vp->v_mount != NULL && 311 vp->v_mount->mnt_kern_flag & MNTK_EXTENDED_SHARED) 312 lock_flags = LK_SHARED; 313 else 314 lock_flags = LK_EXCLUSIVE; 315 316 VFS_ASSERT_GIANT(vp->v_mount); 317 318 vn_start_write(vp, &mp, V_WAIT); 319 vn_lock(vp, lock_flags | LK_RETRY); 320 if (flags & FWRITE) { 321 VNASSERT(vp->v_writecount > 0, vp, 322 ("vn_close: negative writecount")); 323 VOP_ADD_WRITECOUNT(vp, -1); 324 } 325 error = VOP_CLOSE(vp, flags, file_cred, td); 326 vput(vp); 327 vn_finished_write(mp); 328 return (error); 329 } 330 331 /* 332 * Heuristic to detect sequential operation. 333 */ 334 static int 335 sequential_heuristic(struct uio *uio, struct file *fp) 336 { 337 338 if (atomic_load_acq_int(&(fp->f_flag)) & FRDAHEAD) 339 return (fp->f_seqcount << IO_SEQSHIFT); 340 341 /* 342 * Offset 0 is handled specially. open() sets f_seqcount to 1 so 343 * that the first I/O is normally considered to be slightly 344 * sequential. Seeking to offset 0 doesn't change sequentiality 345 * unless previous seeks have reduced f_seqcount to 0, in which 346 * case offset 0 is not special. 347 */ 348 if ((uio->uio_offset == 0 && fp->f_seqcount > 0) || 349 uio->uio_offset == fp->f_nextoff) { 350 /* 351 * f_seqcount is in units of fixed-size blocks so that it 352 * depends mainly on the amount of sequential I/O and not 353 * much on the number of sequential I/O's. The fixed size 354 * of 16384 is hard-coded here since it is (not quite) just 355 * a magic size that works well here. This size is more 356 * closely related to the best I/O size for real disks than 357 * to any block size used by software. 358 */ 359 fp->f_seqcount += howmany(uio->uio_resid, 16384); 360 if (fp->f_seqcount > IO_SEQMAX) 361 fp->f_seqcount = IO_SEQMAX; 362 return (fp->f_seqcount << IO_SEQSHIFT); 363 } 364 365 /* Not sequential. Quickly draw-down sequentiality. */ 366 if (fp->f_seqcount > 1) 367 fp->f_seqcount = 1; 368 else 369 fp->f_seqcount = 0; 370 return (0); 371 } 372 373 /* 374 * Package up an I/O request on a vnode into a uio and do it. 375 */ 376 int 377 vn_rdwr(enum uio_rw rw, struct vnode *vp, void *base, int len, off_t offset, 378 enum uio_seg segflg, int ioflg, struct ucred *active_cred, 379 struct ucred *file_cred, ssize_t *aresid, struct thread *td) 380 { 381 struct uio auio; 382 struct iovec aiov; 383 struct mount *mp; 384 struct ucred *cred; 385 void *rl_cookie; 386 int error, lock_flags; 387 388 VFS_ASSERT_GIANT(vp->v_mount); 389 390 auio.uio_iov = &aiov; 391 auio.uio_iovcnt = 1; 392 aiov.iov_base = base; 393 aiov.iov_len = len; 394 auio.uio_resid = len; 395 auio.uio_offset = offset; 396 auio.uio_segflg = segflg; 397 auio.uio_rw = rw; 398 auio.uio_td = td; 399 error = 0; 400 401 if ((ioflg & IO_NODELOCKED) == 0) { 402 if (rw == UIO_READ) { 403 rl_cookie = vn_rangelock_rlock(vp, offset, 404 offset + len); 405 } else { 406 rl_cookie = vn_rangelock_wlock(vp, offset, 407 offset + len); 408 } 409 mp = NULL; 410 if (rw == UIO_WRITE) { 411 if (vp->v_type != VCHR && 412 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) 413 != 0) 414 goto out; 415 if (MNT_SHARED_WRITES(mp) || 416 ((mp == NULL) && MNT_SHARED_WRITES(vp->v_mount))) 417 lock_flags = LK_SHARED; 418 else 419 lock_flags = LK_EXCLUSIVE; 420 } else 421 lock_flags = LK_SHARED; 422 vn_lock(vp, lock_flags | LK_RETRY); 423 } else 424 rl_cookie = NULL; 425 426 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 427 #ifdef MAC 428 if ((ioflg & IO_NOMACCHECK) == 0) { 429 if (rw == UIO_READ) 430 error = mac_vnode_check_read(active_cred, file_cred, 431 vp); 432 else 433 error = mac_vnode_check_write(active_cred, file_cred, 434 vp); 435 } 436 #endif 437 if (error == 0) { 438 if (file_cred != NULL) 439 cred = file_cred; 440 else 441 cred = active_cred; 442 if (rw == UIO_READ) 443 error = VOP_READ(vp, &auio, ioflg, cred); 444 else 445 error = VOP_WRITE(vp, &auio, ioflg, cred); 446 } 447 if (aresid) 448 *aresid = auio.uio_resid; 449 else 450 if (auio.uio_resid && error == 0) 451 error = EIO; 452 if ((ioflg & IO_NODELOCKED) == 0) { 453 VOP_UNLOCK(vp, 0); 454 if (mp != NULL) 455 vn_finished_write(mp); 456 } 457 out: 458 if (rl_cookie != NULL) 459 vn_rangelock_unlock(vp, rl_cookie); 460 return (error); 461 } 462 463 /* 464 * Package up an I/O request on a vnode into a uio and do it. The I/O 465 * request is split up into smaller chunks and we try to avoid saturating 466 * the buffer cache while potentially holding a vnode locked, so we 467 * check bwillwrite() before calling vn_rdwr(). We also call kern_yield() 468 * to give other processes a chance to lock the vnode (either other processes 469 * core'ing the same binary, or unrelated processes scanning the directory). 470 */ 471 int 472 vn_rdwr_inchunks(rw, vp, base, len, offset, segflg, ioflg, active_cred, 473 file_cred, aresid, td) 474 enum uio_rw rw; 475 struct vnode *vp; 476 void *base; 477 size_t len; 478 off_t offset; 479 enum uio_seg segflg; 480 int ioflg; 481 struct ucred *active_cred; 482 struct ucred *file_cred; 483 size_t *aresid; 484 struct thread *td; 485 { 486 int error = 0; 487 ssize_t iaresid; 488 489 VFS_ASSERT_GIANT(vp->v_mount); 490 491 do { 492 int chunk; 493 494 /* 495 * Force `offset' to a multiple of MAXBSIZE except possibly 496 * for the first chunk, so that filesystems only need to 497 * write full blocks except possibly for the first and last 498 * chunks. 499 */ 500 chunk = MAXBSIZE - (uoff_t)offset % MAXBSIZE; 501 502 if (chunk > len) 503 chunk = len; 504 if (rw != UIO_READ && vp->v_type == VREG) 505 bwillwrite(); 506 iaresid = 0; 507 error = vn_rdwr(rw, vp, base, chunk, offset, segflg, 508 ioflg, active_cred, file_cred, &iaresid, td); 509 len -= chunk; /* aresid calc already includes length */ 510 if (error) 511 break; 512 offset += chunk; 513 base = (char *)base + chunk; 514 kern_yield(PRI_USER); 515 } while (len); 516 if (aresid) 517 *aresid = len + iaresid; 518 return (error); 519 } 520 521 off_t 522 foffset_lock(struct file *fp, int flags) 523 { 524 struct mtx *mtxp; 525 off_t res; 526 527 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed")); 528 529 #if OFF_MAX <= LONG_MAX 530 /* 531 * Caller only wants the current f_offset value. Assume that 532 * the long and shorter integer types reads are atomic. 533 */ 534 if ((flags & FOF_NOLOCK) != 0) 535 return (fp->f_offset); 536 #endif 537 538 /* 539 * According to McKusick the vn lock was protecting f_offset here. 540 * It is now protected by the FOFFSET_LOCKED flag. 541 */ 542 mtxp = mtx_pool_find(mtxpool_sleep, fp); 543 mtx_lock(mtxp); 544 if ((flags & FOF_NOLOCK) == 0) { 545 while (fp->f_vnread_flags & FOFFSET_LOCKED) { 546 fp->f_vnread_flags |= FOFFSET_LOCK_WAITING; 547 msleep(&fp->f_vnread_flags, mtxp, PUSER -1, 548 "vofflock", 0); 549 } 550 fp->f_vnread_flags |= FOFFSET_LOCKED; 551 } 552 res = fp->f_offset; 553 mtx_unlock(mtxp); 554 return (res); 555 } 556 557 void 558 foffset_unlock(struct file *fp, off_t val, int flags) 559 { 560 struct mtx *mtxp; 561 562 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed")); 563 564 #if OFF_MAX <= LONG_MAX 565 if ((flags & FOF_NOLOCK) != 0) { 566 if ((flags & FOF_NOUPDATE) == 0) 567 fp->f_offset = val; 568 if ((flags & FOF_NEXTOFF) != 0) 569 fp->f_nextoff = val; 570 return; 571 } 572 #endif 573 574 mtxp = mtx_pool_find(mtxpool_sleep, fp); 575 mtx_lock(mtxp); 576 if ((flags & FOF_NOUPDATE) == 0) 577 fp->f_offset = val; 578 if ((flags & FOF_NEXTOFF) != 0) 579 fp->f_nextoff = val; 580 if ((flags & FOF_NOLOCK) == 0) { 581 KASSERT((fp->f_vnread_flags & FOFFSET_LOCKED) != 0, 582 ("Lost FOFFSET_LOCKED")); 583 if (fp->f_vnread_flags & FOFFSET_LOCK_WAITING) 584 wakeup(&fp->f_vnread_flags); 585 fp->f_vnread_flags = 0; 586 } 587 mtx_unlock(mtxp); 588 } 589 590 void 591 foffset_lock_uio(struct file *fp, struct uio *uio, int flags) 592 { 593 594 if ((flags & FOF_OFFSET) == 0) 595 uio->uio_offset = foffset_lock(fp, flags); 596 } 597 598 void 599 foffset_unlock_uio(struct file *fp, struct uio *uio, int flags) 600 { 601 602 if ((flags & FOF_OFFSET) == 0) 603 foffset_unlock(fp, uio->uio_offset, flags); 604 } 605 606 static int 607 get_advice(struct file *fp, struct uio *uio) 608 { 609 struct mtx *mtxp; 610 int ret; 611 612 ret = POSIX_FADV_NORMAL; 613 if (fp->f_advice == NULL) 614 return (ret); 615 616 mtxp = mtx_pool_find(mtxpool_sleep, fp); 617 mtx_lock(mtxp); 618 if (uio->uio_offset >= fp->f_advice->fa_start && 619 uio->uio_offset + uio->uio_resid <= fp->f_advice->fa_end) 620 ret = fp->f_advice->fa_advice; 621 mtx_unlock(mtxp); 622 return (ret); 623 } 624 625 /* 626 * File table vnode read routine. 627 */ 628 static int 629 vn_read(fp, uio, active_cred, flags, td) 630 struct file *fp; 631 struct uio *uio; 632 struct ucred *active_cred; 633 int flags; 634 struct thread *td; 635 { 636 struct vnode *vp; 637 struct mtx *mtxp; 638 int error, ioflag; 639 int advice, vfslocked; 640 off_t offset, start, end; 641 642 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", 643 uio->uio_td, td)); 644 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET")); 645 vp = fp->f_vnode; 646 ioflag = 0; 647 if (fp->f_flag & FNONBLOCK) 648 ioflag |= IO_NDELAY; 649 if (fp->f_flag & O_DIRECT) 650 ioflag |= IO_DIRECT; 651 advice = get_advice(fp, uio); 652 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 653 vn_lock(vp, LK_SHARED | LK_RETRY); 654 655 switch (advice) { 656 case POSIX_FADV_NORMAL: 657 case POSIX_FADV_SEQUENTIAL: 658 case POSIX_FADV_NOREUSE: 659 ioflag |= sequential_heuristic(uio, fp); 660 break; 661 case POSIX_FADV_RANDOM: 662 /* Disable read-ahead for random I/O. */ 663 break; 664 } 665 offset = uio->uio_offset; 666 667 #ifdef MAC 668 error = mac_vnode_check_read(active_cred, fp->f_cred, vp); 669 if (error == 0) 670 #endif 671 error = VOP_READ(vp, uio, ioflag, fp->f_cred); 672 fp->f_nextoff = uio->uio_offset; 673 VOP_UNLOCK(vp, 0); 674 if (error == 0 && advice == POSIX_FADV_NOREUSE && 675 offset != uio->uio_offset) { 676 /* 677 * Use POSIX_FADV_DONTNEED to flush clean pages and 678 * buffers for the backing file after a 679 * POSIX_FADV_NOREUSE read(2). To optimize the common 680 * case of using POSIX_FADV_NOREUSE with sequential 681 * access, track the previous implicit DONTNEED 682 * request and grow this request to include the 683 * current read(2) in addition to the previous 684 * DONTNEED. With purely sequential access this will 685 * cause the DONTNEED requests to continously grow to 686 * cover all of the previously read regions of the 687 * file. This allows filesystem blocks that are 688 * accessed by multiple calls to read(2) to be flushed 689 * once the last read(2) finishes. 690 */ 691 start = offset; 692 end = uio->uio_offset - 1; 693 mtxp = mtx_pool_find(mtxpool_sleep, fp); 694 mtx_lock(mtxp); 695 if (fp->f_advice != NULL && 696 fp->f_advice->fa_advice == POSIX_FADV_NOREUSE) { 697 if (start != 0 && fp->f_advice->fa_prevend + 1 == start) 698 start = fp->f_advice->fa_prevstart; 699 else if (fp->f_advice->fa_prevstart != 0 && 700 fp->f_advice->fa_prevstart == end + 1) 701 end = fp->f_advice->fa_prevend; 702 fp->f_advice->fa_prevstart = start; 703 fp->f_advice->fa_prevend = end; 704 } 705 mtx_unlock(mtxp); 706 error = VOP_ADVISE(vp, start, end, POSIX_FADV_DONTNEED); 707 } 708 VFS_UNLOCK_GIANT(vfslocked); 709 return (error); 710 } 711 712 /* 713 * File table vnode write routine. 714 */ 715 static int 716 vn_write(fp, uio, active_cred, flags, td) 717 struct file *fp; 718 struct uio *uio; 719 struct ucred *active_cred; 720 int flags; 721 struct thread *td; 722 { 723 struct vnode *vp; 724 struct mount *mp; 725 struct mtx *mtxp; 726 int error, ioflag, lock_flags; 727 int advice, vfslocked; 728 off_t offset, start, end; 729 730 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", 731 uio->uio_td, td)); 732 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET")); 733 vp = fp->f_vnode; 734 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 735 if (vp->v_type == VREG) 736 bwillwrite(); 737 ioflag = IO_UNIT; 738 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 739 ioflag |= IO_APPEND; 740 if (fp->f_flag & FNONBLOCK) 741 ioflag |= IO_NDELAY; 742 if (fp->f_flag & O_DIRECT) 743 ioflag |= IO_DIRECT; 744 if ((fp->f_flag & O_FSYNC) || 745 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS))) 746 ioflag |= IO_SYNC; 747 mp = NULL; 748 if (vp->v_type != VCHR && 749 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0) 750 goto unlock; 751 752 advice = get_advice(fp, uio); 753 754 if ((MNT_SHARED_WRITES(mp) || 755 ((mp == NULL) && MNT_SHARED_WRITES(vp->v_mount))) && 756 (flags & FOF_OFFSET) != 0) { 757 lock_flags = LK_SHARED; 758 } else { 759 lock_flags = LK_EXCLUSIVE; 760 } 761 762 vn_lock(vp, lock_flags | LK_RETRY); 763 switch (advice) { 764 case POSIX_FADV_NORMAL: 765 case POSIX_FADV_SEQUENTIAL: 766 case POSIX_FADV_NOREUSE: 767 ioflag |= sequential_heuristic(uio, fp); 768 break; 769 case POSIX_FADV_RANDOM: 770 /* XXX: Is this correct? */ 771 break; 772 } 773 offset = uio->uio_offset; 774 775 #ifdef MAC 776 error = mac_vnode_check_write(active_cred, fp->f_cred, vp); 777 if (error == 0) 778 #endif 779 error = VOP_WRITE(vp, uio, ioflag, fp->f_cred); 780 fp->f_nextoff = uio->uio_offset; 781 VOP_UNLOCK(vp, 0); 782 if (vp->v_type != VCHR) 783 vn_finished_write(mp); 784 if (error == 0 && advice == POSIX_FADV_NOREUSE && 785 offset != uio->uio_offset) { 786 /* 787 * Use POSIX_FADV_DONTNEED to flush clean pages and 788 * buffers for the backing file after a 789 * POSIX_FADV_NOREUSE write(2). To optimize the 790 * common case of using POSIX_FADV_NOREUSE with 791 * sequential access, track the previous implicit 792 * DONTNEED request and grow this request to include 793 * the current write(2) in addition to the previous 794 * DONTNEED. With purely sequential access this will 795 * cause the DONTNEED requests to continously grow to 796 * cover all of the previously written regions of the 797 * file. 798 * 799 * Note that the blocks just written are almost 800 * certainly still dirty, so this only works when 801 * VOP_ADVISE() calls from subsequent writes push out 802 * the data written by this write(2) once the backing 803 * buffers are clean. However, as compared to forcing 804 * IO_DIRECT, this gives much saner behavior. Write 805 * clustering is still allowed, and clean pages are 806 * merely moved to the cache page queue rather than 807 * outright thrown away. This means a subsequent 808 * read(2) can still avoid hitting the disk if the 809 * pages have not been reclaimed. 810 * 811 * This does make POSIX_FADV_NOREUSE largely useless 812 * with non-sequential access. However, sequential 813 * access is the more common use case and the flag is 814 * merely advisory. 815 */ 816 start = offset; 817 end = uio->uio_offset - 1; 818 mtxp = mtx_pool_find(mtxpool_sleep, fp); 819 mtx_lock(mtxp); 820 if (fp->f_advice != NULL && 821 fp->f_advice->fa_advice == POSIX_FADV_NOREUSE) { 822 if (start != 0 && fp->f_advice->fa_prevend + 1 == start) 823 start = fp->f_advice->fa_prevstart; 824 else if (fp->f_advice->fa_prevstart != 0 && 825 fp->f_advice->fa_prevstart == end + 1) 826 end = fp->f_advice->fa_prevend; 827 fp->f_advice->fa_prevstart = start; 828 fp->f_advice->fa_prevend = end; 829 } 830 mtx_unlock(mtxp); 831 error = VOP_ADVISE(vp, start, end, POSIX_FADV_DONTNEED); 832 } 833 834 unlock: 835 VFS_UNLOCK_GIANT(vfslocked); 836 return (error); 837 } 838 839 static const int io_hold_cnt = 16; 840 static int vn_io_fault_enable = 0; 841 SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_enable, CTLFLAG_RW, 842 &vn_io_fault_enable, 0, "Enable vn_io_fault lock avoidance"); 843 static u_long vn_io_faults_cnt; 844 SYSCTL_ULONG(_debug, OID_AUTO, vn_io_faults, CTLFLAG_RD, 845 &vn_io_faults_cnt, 0, "Count of vn_io_fault lock avoidance triggers"); 846 847 /* 848 * The vn_io_fault() is a wrapper around vn_read() and vn_write() to 849 * prevent the following deadlock: 850 * 851 * Assume that the thread A reads from the vnode vp1 into userspace 852 * buffer buf1 backed by the pages of vnode vp2. If a page in buf1 is 853 * currently not resident, then system ends up with the call chain 854 * vn_read() -> VOP_READ(vp1) -> uiomove() -> [Page Fault] -> 855 * vm_fault(buf1) -> vnode_pager_getpages(vp2) -> VOP_GETPAGES(vp2) 856 * which establishes lock order vp1->vn_lock, then vp2->vn_lock. 857 * If, at the same time, thread B reads from vnode vp2 into buffer buf2 858 * backed by the pages of vnode vp1, and some page in buf2 is not 859 * resident, we get a reversed order vp2->vn_lock, then vp1->vn_lock. 860 * 861 * To prevent the lock order reversal and deadlock, vn_io_fault() does 862 * not allow page faults to happen during VOP_READ() or VOP_WRITE(). 863 * Instead, it first tries to do the whole range i/o with pagefaults 864 * disabled. If all pages in the i/o buffer are resident and mapped, 865 * VOP will succeed (ignoring the genuine filesystem errors). 866 * Otherwise, we get back EFAULT, and vn_io_fault() falls back to do 867 * i/o in chunks, with all pages in the chunk prefaulted and held 868 * using vm_fault_quick_hold_pages(). 869 * 870 * Filesystems using this deadlock avoidance scheme should use the 871 * array of the held pages from uio, saved in the curthread->td_ma, 872 * instead of doing uiomove(). A helper function 873 * vn_io_fault_uiomove() converts uiomove request into 874 * uiomove_fromphys() over td_ma array. 875 * 876 * Since vnode locks do not cover the whole i/o anymore, rangelocks 877 * make the current i/o request atomic with respect to other i/os and 878 * truncations. 879 */ 880 static int 881 vn_io_fault(struct file *fp, struct uio *uio, struct ucred *active_cred, 882 int flags, struct thread *td) 883 { 884 vm_page_t ma[io_hold_cnt + 2]; 885 struct uio *uio_clone, short_uio; 886 struct iovec short_iovec[1]; 887 fo_rdwr_t *doio; 888 struct vnode *vp; 889 void *rl_cookie; 890 struct mount *mp; 891 vm_page_t *prev_td_ma; 892 int cnt, error, save, saveheld, prev_td_ma_cnt; 893 vm_offset_t addr, end; 894 vm_prot_t prot; 895 size_t len, resid; 896 ssize_t adv; 897 898 if (uio->uio_rw == UIO_READ) 899 doio = vn_read; 900 else 901 doio = vn_write; 902 vp = fp->f_vnode; 903 foffset_lock_uio(fp, uio, flags); 904 905 if (uio->uio_segflg != UIO_USERSPACE || vp->v_type != VREG || 906 ((mp = vp->v_mount) != NULL && 907 (mp->mnt_kern_flag & MNTK_NO_IOPF) == 0) || 908 !vn_io_fault_enable) { 909 error = doio(fp, uio, active_cred, flags | FOF_OFFSET, td); 910 goto out_last; 911 } 912 913 /* 914 * The UFS follows IO_UNIT directive and replays back both 915 * uio_offset and uio_resid if an error is encountered during the 916 * operation. But, since the iovec may be already advanced, 917 * uio is still in an inconsistent state. 918 * 919 * Cache a copy of the original uio, which is advanced to the redo 920 * point using UIO_NOCOPY below. 921 */ 922 uio_clone = cloneuio(uio); 923 resid = uio->uio_resid; 924 925 short_uio.uio_segflg = UIO_USERSPACE; 926 short_uio.uio_rw = uio->uio_rw; 927 short_uio.uio_td = uio->uio_td; 928 929 if (uio->uio_rw == UIO_READ) { 930 prot = VM_PROT_WRITE; 931 rl_cookie = vn_rangelock_rlock(vp, uio->uio_offset, 932 uio->uio_offset + uio->uio_resid); 933 } else { 934 prot = VM_PROT_READ; 935 if ((fp->f_flag & O_APPEND) != 0 || (flags & FOF_OFFSET) == 0) 936 /* For appenders, punt and lock the whole range. */ 937 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 938 else 939 rl_cookie = vn_rangelock_wlock(vp, uio->uio_offset, 940 uio->uio_offset + uio->uio_resid); 941 } 942 943 save = vm_fault_disable_pagefaults(); 944 error = doio(fp, uio, active_cred, flags | FOF_OFFSET, td); 945 if (error != EFAULT) 946 goto out; 947 948 atomic_add_long(&vn_io_faults_cnt, 1); 949 uio_clone->uio_segflg = UIO_NOCOPY; 950 uiomove(NULL, resid - uio->uio_resid, uio_clone); 951 uio_clone->uio_segflg = uio->uio_segflg; 952 953 saveheld = curthread_pflags_set(TDP_UIOHELD); 954 prev_td_ma = td->td_ma; 955 prev_td_ma_cnt = td->td_ma_cnt; 956 957 while (uio_clone->uio_resid != 0) { 958 len = uio_clone->uio_iov->iov_len; 959 if (len == 0) { 960 KASSERT(uio_clone->uio_iovcnt >= 1, 961 ("iovcnt underflow")); 962 uio_clone->uio_iov++; 963 uio_clone->uio_iovcnt--; 964 continue; 965 } 966 967 addr = (vm_offset_t)uio_clone->uio_iov->iov_base; 968 end = round_page(addr + len); 969 cnt = howmany(end - trunc_page(addr), PAGE_SIZE); 970 /* 971 * A perfectly misaligned address and length could cause 972 * both the start and the end of the chunk to use partial 973 * page. +2 accounts for such a situation. 974 */ 975 if (cnt > io_hold_cnt + 2) { 976 len = io_hold_cnt * PAGE_SIZE; 977 KASSERT(howmany(round_page(addr + len) - 978 trunc_page(addr), PAGE_SIZE) <= io_hold_cnt + 2, 979 ("cnt overflow")); 980 } 981 cnt = vm_fault_quick_hold_pages(&td->td_proc->p_vmspace->vm_map, 982 addr, len, prot, ma, io_hold_cnt + 2); 983 if (cnt == -1) { 984 error = EFAULT; 985 break; 986 } 987 short_uio.uio_iov = &short_iovec[0]; 988 short_iovec[0].iov_base = (void *)addr; 989 short_uio.uio_iovcnt = 1; 990 short_uio.uio_resid = short_iovec[0].iov_len = len; 991 short_uio.uio_offset = uio_clone->uio_offset; 992 td->td_ma = ma; 993 td->td_ma_cnt = cnt; 994 995 error = doio(fp, &short_uio, active_cred, flags | FOF_OFFSET, 996 td); 997 vm_page_unhold_pages(ma, cnt); 998 adv = len - short_uio.uio_resid; 999 1000 uio_clone->uio_iov->iov_base = 1001 (char *)uio_clone->uio_iov->iov_base + adv; 1002 uio_clone->uio_iov->iov_len -= adv; 1003 uio_clone->uio_resid -= adv; 1004 uio_clone->uio_offset += adv; 1005 1006 uio->uio_resid -= adv; 1007 uio->uio_offset += adv; 1008 1009 if (error != 0 || adv == 0) 1010 break; 1011 } 1012 td->td_ma = prev_td_ma; 1013 td->td_ma_cnt = prev_td_ma_cnt; 1014 curthread_pflags_restore(saveheld); 1015 out: 1016 vm_fault_enable_pagefaults(save); 1017 vn_rangelock_unlock(vp, rl_cookie); 1018 free(uio_clone, M_IOV); 1019 out_last: 1020 foffset_unlock_uio(fp, uio, flags); 1021 return (error); 1022 } 1023 1024 /* 1025 * Helper function to perform the requested uiomove operation using 1026 * the held pages for io->uio_iov[0].iov_base buffer instead of 1027 * copyin/copyout. Access to the pages with uiomove_fromphys() 1028 * instead of iov_base prevents page faults that could occur due to 1029 * pmap_collect() invalidating the mapping created by 1030 * vm_fault_quick_hold_pages(), or pageout daemon, page laundry or 1031 * object cleanup revoking the write access from page mappings. 1032 * 1033 * Filesystems specified MNTK_NO_IOPF shall use vn_io_fault_uiomove() 1034 * instead of plain uiomove(). 1035 */ 1036 int 1037 vn_io_fault_uiomove(char *data, int xfersize, struct uio *uio) 1038 { 1039 struct uio transp_uio; 1040 struct iovec transp_iov[1]; 1041 struct thread *td; 1042 size_t adv; 1043 int error, pgadv; 1044 1045 td = curthread; 1046 if ((td->td_pflags & TDP_UIOHELD) == 0 || 1047 uio->uio_segflg != UIO_USERSPACE) 1048 return (uiomove(data, xfersize, uio)); 1049 1050 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt)); 1051 transp_iov[0].iov_base = data; 1052 transp_uio.uio_iov = &transp_iov[0]; 1053 transp_uio.uio_iovcnt = 1; 1054 if (xfersize > uio->uio_resid) 1055 xfersize = uio->uio_resid; 1056 transp_uio.uio_resid = transp_iov[0].iov_len = xfersize; 1057 transp_uio.uio_offset = 0; 1058 transp_uio.uio_segflg = UIO_SYSSPACE; 1059 /* 1060 * Since transp_iov points to data, and td_ma page array 1061 * corresponds to original uio->uio_iov, we need to invert the 1062 * direction of the i/o operation as passed to 1063 * uiomove_fromphys(). 1064 */ 1065 switch (uio->uio_rw) { 1066 case UIO_WRITE: 1067 transp_uio.uio_rw = UIO_READ; 1068 break; 1069 case UIO_READ: 1070 transp_uio.uio_rw = UIO_WRITE; 1071 break; 1072 } 1073 transp_uio.uio_td = uio->uio_td; 1074 error = uiomove_fromphys(td->td_ma, 1075 ((vm_offset_t)uio->uio_iov->iov_base) & PAGE_MASK, 1076 xfersize, &transp_uio); 1077 adv = xfersize - transp_uio.uio_resid; 1078 pgadv = 1079 (((vm_offset_t)uio->uio_iov->iov_base + adv) >> PAGE_SHIFT) - 1080 (((vm_offset_t)uio->uio_iov->iov_base) >> PAGE_SHIFT); 1081 td->td_ma += pgadv; 1082 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt, 1083 pgadv)); 1084 td->td_ma_cnt -= pgadv; 1085 uio->uio_iov->iov_base = (char *)uio->uio_iov->iov_base + adv; 1086 uio->uio_iov->iov_len -= adv; 1087 uio->uio_resid -= adv; 1088 uio->uio_offset += adv; 1089 return (error); 1090 } 1091 1092 int 1093 vn_io_fault_pgmove(vm_page_t ma[], vm_offset_t offset, int xfersize, 1094 struct uio *uio) 1095 { 1096 struct thread *td; 1097 vm_offset_t iov_base; 1098 int cnt, pgadv; 1099 1100 td = curthread; 1101 if ((td->td_pflags & TDP_UIOHELD) == 0 || 1102 uio->uio_segflg != UIO_USERSPACE) 1103 return (uiomove_fromphys(ma, offset, xfersize, uio)); 1104 1105 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt)); 1106 cnt = xfersize > uio->uio_resid ? uio->uio_resid : xfersize; 1107 iov_base = (vm_offset_t)uio->uio_iov->iov_base; 1108 switch (uio->uio_rw) { 1109 case UIO_WRITE: 1110 pmap_copy_pages(td->td_ma, iov_base & PAGE_MASK, ma, 1111 offset, cnt); 1112 break; 1113 case UIO_READ: 1114 pmap_copy_pages(ma, offset, td->td_ma, iov_base & PAGE_MASK, 1115 cnt); 1116 break; 1117 } 1118 pgadv = ((iov_base + cnt) >> PAGE_SHIFT) - (iov_base >> PAGE_SHIFT); 1119 td->td_ma += pgadv; 1120 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt, 1121 pgadv)); 1122 td->td_ma_cnt -= pgadv; 1123 uio->uio_iov->iov_base = (char *)(iov_base + cnt); 1124 uio->uio_iov->iov_len -= cnt; 1125 uio->uio_resid -= cnt; 1126 uio->uio_offset += cnt; 1127 return (0); 1128 } 1129 1130 1131 /* 1132 * File table truncate routine. 1133 */ 1134 static int 1135 vn_truncate(struct file *fp, off_t length, struct ucred *active_cred, 1136 struct thread *td) 1137 { 1138 struct vattr vattr; 1139 struct mount *mp; 1140 struct vnode *vp; 1141 void *rl_cookie; 1142 int vfslocked; 1143 int error; 1144 1145 vp = fp->f_vnode; 1146 1147 /* 1148 * Lock the whole range for truncation. Otherwise split i/o 1149 * might happen partly before and partly after the truncation. 1150 */ 1151 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 1152 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 1153 error = vn_start_write(vp, &mp, V_WAIT | PCATCH); 1154 if (error) 1155 goto out1; 1156 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1157 if (vp->v_type == VDIR) { 1158 error = EISDIR; 1159 goto out; 1160 } 1161 #ifdef MAC 1162 error = mac_vnode_check_write(active_cred, fp->f_cred, vp); 1163 if (error) 1164 goto out; 1165 #endif 1166 error = vn_writechk(vp); 1167 if (error == 0) { 1168 VATTR_NULL(&vattr); 1169 vattr.va_size = length; 1170 error = VOP_SETATTR(vp, &vattr, fp->f_cred); 1171 } 1172 out: 1173 VOP_UNLOCK(vp, 0); 1174 vn_finished_write(mp); 1175 out1: 1176 VFS_UNLOCK_GIANT(vfslocked); 1177 vn_rangelock_unlock(vp, rl_cookie); 1178 return (error); 1179 } 1180 1181 /* 1182 * File table vnode stat routine. 1183 */ 1184 static int 1185 vn_statfile(fp, sb, active_cred, td) 1186 struct file *fp; 1187 struct stat *sb; 1188 struct ucred *active_cred; 1189 struct thread *td; 1190 { 1191 struct vnode *vp = fp->f_vnode; 1192 int vfslocked; 1193 int error; 1194 1195 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 1196 vn_lock(vp, LK_SHARED | LK_RETRY); 1197 error = vn_stat(vp, sb, active_cred, fp->f_cred, td); 1198 VOP_UNLOCK(vp, 0); 1199 VFS_UNLOCK_GIANT(vfslocked); 1200 1201 return (error); 1202 } 1203 1204 /* 1205 * Stat a vnode; implementation for the stat syscall 1206 */ 1207 int 1208 vn_stat(vp, sb, active_cred, file_cred, td) 1209 struct vnode *vp; 1210 register struct stat *sb; 1211 struct ucred *active_cred; 1212 struct ucred *file_cred; 1213 struct thread *td; 1214 { 1215 struct vattr vattr; 1216 register struct vattr *vap; 1217 int error; 1218 u_short mode; 1219 1220 #ifdef MAC 1221 error = mac_vnode_check_stat(active_cred, file_cred, vp); 1222 if (error) 1223 return (error); 1224 #endif 1225 1226 vap = &vattr; 1227 1228 /* 1229 * Initialize defaults for new and unusual fields, so that file 1230 * systems which don't support these fields don't need to know 1231 * about them. 1232 */ 1233 vap->va_birthtime.tv_sec = -1; 1234 vap->va_birthtime.tv_nsec = 0; 1235 vap->va_fsid = VNOVAL; 1236 vap->va_rdev = NODEV; 1237 1238 error = VOP_GETATTR(vp, vap, active_cred); 1239 if (error) 1240 return (error); 1241 1242 /* 1243 * Zero the spare stat fields 1244 */ 1245 bzero(sb, sizeof *sb); 1246 1247 /* 1248 * Copy from vattr table 1249 */ 1250 if (vap->va_fsid != VNOVAL) 1251 sb->st_dev = vap->va_fsid; 1252 else 1253 sb->st_dev = vp->v_mount->mnt_stat.f_fsid.val[0]; 1254 sb->st_ino = vap->va_fileid; 1255 mode = vap->va_mode; 1256 switch (vap->va_type) { 1257 case VREG: 1258 mode |= S_IFREG; 1259 break; 1260 case VDIR: 1261 mode |= S_IFDIR; 1262 break; 1263 case VBLK: 1264 mode |= S_IFBLK; 1265 break; 1266 case VCHR: 1267 mode |= S_IFCHR; 1268 break; 1269 case VLNK: 1270 mode |= S_IFLNK; 1271 break; 1272 case VSOCK: 1273 mode |= S_IFSOCK; 1274 break; 1275 case VFIFO: 1276 mode |= S_IFIFO; 1277 break; 1278 default: 1279 return (EBADF); 1280 }; 1281 sb->st_mode = mode; 1282 sb->st_nlink = vap->va_nlink; 1283 sb->st_uid = vap->va_uid; 1284 sb->st_gid = vap->va_gid; 1285 sb->st_rdev = vap->va_rdev; 1286 if (vap->va_size > OFF_MAX) 1287 return (EOVERFLOW); 1288 sb->st_size = vap->va_size; 1289 sb->st_atim = vap->va_atime; 1290 sb->st_mtim = vap->va_mtime; 1291 sb->st_ctim = vap->va_ctime; 1292 sb->st_birthtim = vap->va_birthtime; 1293 1294 /* 1295 * According to www.opengroup.org, the meaning of st_blksize is 1296 * "a filesystem-specific preferred I/O block size for this 1297 * object. In some filesystem types, this may vary from file 1298 * to file" 1299 * Use miminum/default of PAGE_SIZE (e.g. for VCHR). 1300 */ 1301 1302 sb->st_blksize = max(PAGE_SIZE, vap->va_blocksize); 1303 1304 sb->st_flags = vap->va_flags; 1305 if (priv_check(td, PRIV_VFS_GENERATION)) 1306 sb->st_gen = 0; 1307 else 1308 sb->st_gen = vap->va_gen; 1309 1310 sb->st_blocks = vap->va_bytes / S_BLKSIZE; 1311 return (0); 1312 } 1313 1314 /* 1315 * File table vnode ioctl routine. 1316 */ 1317 static int 1318 vn_ioctl(fp, com, data, active_cred, td) 1319 struct file *fp; 1320 u_long com; 1321 void *data; 1322 struct ucred *active_cred; 1323 struct thread *td; 1324 { 1325 struct vnode *vp = fp->f_vnode; 1326 struct vattr vattr; 1327 int vfslocked; 1328 int error; 1329 1330 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 1331 error = ENOTTY; 1332 switch (vp->v_type) { 1333 case VREG: 1334 case VDIR: 1335 if (com == FIONREAD) { 1336 vn_lock(vp, LK_SHARED | LK_RETRY); 1337 error = VOP_GETATTR(vp, &vattr, active_cred); 1338 VOP_UNLOCK(vp, 0); 1339 if (!error) 1340 *(int *)data = vattr.va_size - fp->f_offset; 1341 } else if (com == FIONBIO || com == FIOASYNC) /* XXX */ 1342 error = 0; 1343 else 1344 error = VOP_IOCTL(vp, com, data, fp->f_flag, 1345 active_cred, td); 1346 break; 1347 1348 default: 1349 break; 1350 } 1351 VFS_UNLOCK_GIANT(vfslocked); 1352 return (error); 1353 } 1354 1355 /* 1356 * File table vnode poll routine. 1357 */ 1358 static int 1359 vn_poll(fp, events, active_cred, td) 1360 struct file *fp; 1361 int events; 1362 struct ucred *active_cred; 1363 struct thread *td; 1364 { 1365 struct vnode *vp; 1366 int vfslocked; 1367 int error; 1368 1369 vp = fp->f_vnode; 1370 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 1371 #ifdef MAC 1372 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1373 error = mac_vnode_check_poll(active_cred, fp->f_cred, vp); 1374 VOP_UNLOCK(vp, 0); 1375 if (!error) 1376 #endif 1377 1378 error = VOP_POLL(vp, events, fp->f_cred, td); 1379 VFS_UNLOCK_GIANT(vfslocked); 1380 return (error); 1381 } 1382 1383 /* 1384 * Acquire the requested lock and then check for validity. LK_RETRY 1385 * permits vn_lock to return doomed vnodes. 1386 */ 1387 int 1388 _vn_lock(struct vnode *vp, int flags, char *file, int line) 1389 { 1390 int error; 1391 1392 VNASSERT((flags & LK_TYPE_MASK) != 0, vp, 1393 ("vn_lock called with no locktype.")); 1394 do { 1395 #ifdef DEBUG_VFS_LOCKS 1396 KASSERT(vp->v_holdcnt != 0, 1397 ("vn_lock %p: zero hold count", vp)); 1398 #endif 1399 error = VOP_LOCK1(vp, flags, file, line); 1400 flags &= ~LK_INTERLOCK; /* Interlock is always dropped. */ 1401 KASSERT((flags & LK_RETRY) == 0 || error == 0, 1402 ("LK_RETRY set with incompatible flags (0x%x) or an error occured (%d)", 1403 flags, error)); 1404 /* 1405 * Callers specify LK_RETRY if they wish to get dead vnodes. 1406 * If RETRY is not set, we return ENOENT instead. 1407 */ 1408 if (error == 0 && vp->v_iflag & VI_DOOMED && 1409 (flags & LK_RETRY) == 0) { 1410 VOP_UNLOCK(vp, 0); 1411 error = ENOENT; 1412 break; 1413 } 1414 } while (flags & LK_RETRY && error != 0); 1415 return (error); 1416 } 1417 1418 /* 1419 * File table vnode close routine. 1420 */ 1421 static int 1422 vn_closefile(fp, td) 1423 struct file *fp; 1424 struct thread *td; 1425 { 1426 struct vnode *vp; 1427 struct flock lf; 1428 int vfslocked; 1429 int error; 1430 1431 vp = fp->f_vnode; 1432 1433 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 1434 if (fp->f_type == DTYPE_VNODE && fp->f_flag & FHASLOCK) { 1435 lf.l_whence = SEEK_SET; 1436 lf.l_start = 0; 1437 lf.l_len = 0; 1438 lf.l_type = F_UNLCK; 1439 (void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, F_FLOCK); 1440 } 1441 1442 fp->f_ops = &badfileops; 1443 1444 error = vn_close(vp, fp->f_flag, fp->f_cred, td); 1445 VFS_UNLOCK_GIANT(vfslocked); 1446 return (error); 1447 } 1448 1449 /* 1450 * Preparing to start a filesystem write operation. If the operation is 1451 * permitted, then we bump the count of operations in progress and 1452 * proceed. If a suspend request is in progress, we wait until the 1453 * suspension is over, and then proceed. 1454 */ 1455 static int 1456 vn_start_write_locked(struct mount *mp, int flags) 1457 { 1458 int error; 1459 1460 mtx_assert(MNT_MTX(mp), MA_OWNED); 1461 error = 0; 1462 1463 /* 1464 * Check on status of suspension. 1465 */ 1466 if ((curthread->td_pflags & TDP_IGNSUSP) == 0 || 1467 mp->mnt_susp_owner != curthread) { 1468 while ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { 1469 if (flags & V_NOWAIT) { 1470 error = EWOULDBLOCK; 1471 goto unlock; 1472 } 1473 error = msleep(&mp->mnt_flag, MNT_MTX(mp), 1474 (PUSER - 1) | (flags & PCATCH), "suspfs", 0); 1475 if (error) 1476 goto unlock; 1477 } 1478 } 1479 if (flags & V_XSLEEP) 1480 goto unlock; 1481 mp->mnt_writeopcount++; 1482 unlock: 1483 if (error != 0 || (flags & V_XSLEEP) != 0) 1484 MNT_REL(mp); 1485 MNT_IUNLOCK(mp); 1486 return (error); 1487 } 1488 1489 int 1490 vn_start_write(vp, mpp, flags) 1491 struct vnode *vp; 1492 struct mount **mpp; 1493 int flags; 1494 { 1495 struct mount *mp; 1496 int error; 1497 1498 error = 0; 1499 /* 1500 * If a vnode is provided, get and return the mount point that 1501 * to which it will write. 1502 */ 1503 if (vp != NULL) { 1504 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) { 1505 *mpp = NULL; 1506 if (error != EOPNOTSUPP) 1507 return (error); 1508 return (0); 1509 } 1510 } 1511 if ((mp = *mpp) == NULL) 1512 return (0); 1513 1514 /* 1515 * VOP_GETWRITEMOUNT() returns with the mp refcount held through 1516 * a vfs_ref(). 1517 * As long as a vnode is not provided we need to acquire a 1518 * refcount for the provided mountpoint too, in order to 1519 * emulate a vfs_ref(). 1520 */ 1521 MNT_ILOCK(mp); 1522 if (vp == NULL) 1523 MNT_REF(mp); 1524 1525 return (vn_start_write_locked(mp, flags)); 1526 } 1527 1528 /* 1529 * Secondary suspension. Used by operations such as vop_inactive 1530 * routines that are needed by the higher level functions. These 1531 * are allowed to proceed until all the higher level functions have 1532 * completed (indicated by mnt_writeopcount dropping to zero). At that 1533 * time, these operations are halted until the suspension is over. 1534 */ 1535 int 1536 vn_start_secondary_write(vp, mpp, flags) 1537 struct vnode *vp; 1538 struct mount **mpp; 1539 int flags; 1540 { 1541 struct mount *mp; 1542 int error; 1543 1544 retry: 1545 if (vp != NULL) { 1546 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) { 1547 *mpp = NULL; 1548 if (error != EOPNOTSUPP) 1549 return (error); 1550 return (0); 1551 } 1552 } 1553 /* 1554 * If we are not suspended or have not yet reached suspended 1555 * mode, then let the operation proceed. 1556 */ 1557 if ((mp = *mpp) == NULL) 1558 return (0); 1559 1560 /* 1561 * VOP_GETWRITEMOUNT() returns with the mp refcount held through 1562 * a vfs_ref(). 1563 * As long as a vnode is not provided we need to acquire a 1564 * refcount for the provided mountpoint too, in order to 1565 * emulate a vfs_ref(). 1566 */ 1567 MNT_ILOCK(mp); 1568 if (vp == NULL) 1569 MNT_REF(mp); 1570 if ((mp->mnt_kern_flag & (MNTK_SUSPENDED | MNTK_SUSPEND2)) == 0) { 1571 mp->mnt_secondary_writes++; 1572 mp->mnt_secondary_accwrites++; 1573 MNT_IUNLOCK(mp); 1574 return (0); 1575 } 1576 if (flags & V_NOWAIT) { 1577 MNT_REL(mp); 1578 MNT_IUNLOCK(mp); 1579 return (EWOULDBLOCK); 1580 } 1581 /* 1582 * Wait for the suspension to finish. 1583 */ 1584 error = msleep(&mp->mnt_flag, MNT_MTX(mp), 1585 (PUSER - 1) | (flags & PCATCH) | PDROP, "suspfs", 0); 1586 vfs_rel(mp); 1587 if (error == 0) 1588 goto retry; 1589 return (error); 1590 } 1591 1592 /* 1593 * Filesystem write operation has completed. If we are suspending and this 1594 * operation is the last one, notify the suspender that the suspension is 1595 * now in effect. 1596 */ 1597 void 1598 vn_finished_write(mp) 1599 struct mount *mp; 1600 { 1601 if (mp == NULL) 1602 return; 1603 MNT_ILOCK(mp); 1604 MNT_REL(mp); 1605 mp->mnt_writeopcount--; 1606 if (mp->mnt_writeopcount < 0) 1607 panic("vn_finished_write: neg cnt"); 1608 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && 1609 mp->mnt_writeopcount <= 0) 1610 wakeup(&mp->mnt_writeopcount); 1611 MNT_IUNLOCK(mp); 1612 } 1613 1614 1615 /* 1616 * Filesystem secondary write operation has completed. If we are 1617 * suspending and this operation is the last one, notify the suspender 1618 * that the suspension is now in effect. 1619 */ 1620 void 1621 vn_finished_secondary_write(mp) 1622 struct mount *mp; 1623 { 1624 if (mp == NULL) 1625 return; 1626 MNT_ILOCK(mp); 1627 MNT_REL(mp); 1628 mp->mnt_secondary_writes--; 1629 if (mp->mnt_secondary_writes < 0) 1630 panic("vn_finished_secondary_write: neg cnt"); 1631 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && 1632 mp->mnt_secondary_writes <= 0) 1633 wakeup(&mp->mnt_secondary_writes); 1634 MNT_IUNLOCK(mp); 1635 } 1636 1637 1638 1639 /* 1640 * Request a filesystem to suspend write operations. 1641 */ 1642 int 1643 vfs_write_suspend(mp) 1644 struct mount *mp; 1645 { 1646 int error; 1647 1648 MNT_ILOCK(mp); 1649 if (mp->mnt_susp_owner == curthread) { 1650 MNT_IUNLOCK(mp); 1651 return (EALREADY); 1652 } 1653 while (mp->mnt_kern_flag & MNTK_SUSPEND) 1654 msleep(&mp->mnt_flag, MNT_MTX(mp), PUSER - 1, "wsuspfs", 0); 1655 mp->mnt_kern_flag |= MNTK_SUSPEND; 1656 mp->mnt_susp_owner = curthread; 1657 if (mp->mnt_writeopcount > 0) 1658 (void) msleep(&mp->mnt_writeopcount, 1659 MNT_MTX(mp), (PUSER - 1)|PDROP, "suspwt", 0); 1660 else 1661 MNT_IUNLOCK(mp); 1662 if ((error = VFS_SYNC(mp, MNT_SUSPEND)) != 0) 1663 vfs_write_resume(mp); 1664 return (error); 1665 } 1666 1667 /* 1668 * Request a filesystem to resume write operations. 1669 */ 1670 void 1671 vfs_write_resume_flags(struct mount *mp, int flags) 1672 { 1673 1674 MNT_ILOCK(mp); 1675 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { 1676 KASSERT(mp->mnt_susp_owner == curthread, ("mnt_susp_owner")); 1677 mp->mnt_kern_flag &= ~(MNTK_SUSPEND | MNTK_SUSPEND2 | 1678 MNTK_SUSPENDED); 1679 mp->mnt_susp_owner = NULL; 1680 wakeup(&mp->mnt_writeopcount); 1681 wakeup(&mp->mnt_flag); 1682 curthread->td_pflags &= ~TDP_IGNSUSP; 1683 if ((flags & VR_START_WRITE) != 0) { 1684 MNT_REF(mp); 1685 mp->mnt_writeopcount++; 1686 } 1687 MNT_IUNLOCK(mp); 1688 if ((flags & VR_NO_SUSPCLR) == 0) 1689 VFS_SUSP_CLEAN(mp); 1690 } else if ((flags & VR_START_WRITE) != 0) { 1691 MNT_REF(mp); 1692 vn_start_write_locked(mp, 0); 1693 } else { 1694 MNT_IUNLOCK(mp); 1695 } 1696 } 1697 1698 void 1699 vfs_write_resume(struct mount *mp) 1700 { 1701 1702 vfs_write_resume_flags(mp, 0); 1703 } 1704 1705 /* 1706 * Implement kqueues for files by translating it to vnode operation. 1707 */ 1708 static int 1709 vn_kqfilter(struct file *fp, struct knote *kn) 1710 { 1711 int vfslocked; 1712 int error; 1713 1714 vfslocked = VFS_LOCK_GIANT(fp->f_vnode->v_mount); 1715 error = VOP_KQFILTER(fp->f_vnode, kn); 1716 VFS_UNLOCK_GIANT(vfslocked); 1717 1718 return error; 1719 } 1720 1721 /* 1722 * Simplified in-kernel wrapper calls for extended attribute access. 1723 * Both calls pass in a NULL credential, authorizing as "kernel" access. 1724 * Set IO_NODELOCKED in ioflg if the vnode is already locked. 1725 */ 1726 int 1727 vn_extattr_get(struct vnode *vp, int ioflg, int attrnamespace, 1728 const char *attrname, int *buflen, char *buf, struct thread *td) 1729 { 1730 struct uio auio; 1731 struct iovec iov; 1732 int error; 1733 1734 iov.iov_len = *buflen; 1735 iov.iov_base = buf; 1736 1737 auio.uio_iov = &iov; 1738 auio.uio_iovcnt = 1; 1739 auio.uio_rw = UIO_READ; 1740 auio.uio_segflg = UIO_SYSSPACE; 1741 auio.uio_td = td; 1742 auio.uio_offset = 0; 1743 auio.uio_resid = *buflen; 1744 1745 if ((ioflg & IO_NODELOCKED) == 0) 1746 vn_lock(vp, LK_SHARED | LK_RETRY); 1747 1748 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 1749 1750 /* authorize attribute retrieval as kernel */ 1751 error = VOP_GETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, NULL, 1752 td); 1753 1754 if ((ioflg & IO_NODELOCKED) == 0) 1755 VOP_UNLOCK(vp, 0); 1756 1757 if (error == 0) { 1758 *buflen = *buflen - auio.uio_resid; 1759 } 1760 1761 return (error); 1762 } 1763 1764 /* 1765 * XXX failure mode if partially written? 1766 */ 1767 int 1768 vn_extattr_set(struct vnode *vp, int ioflg, int attrnamespace, 1769 const char *attrname, int buflen, char *buf, struct thread *td) 1770 { 1771 struct uio auio; 1772 struct iovec iov; 1773 struct mount *mp; 1774 int error; 1775 1776 iov.iov_len = buflen; 1777 iov.iov_base = buf; 1778 1779 auio.uio_iov = &iov; 1780 auio.uio_iovcnt = 1; 1781 auio.uio_rw = UIO_WRITE; 1782 auio.uio_segflg = UIO_SYSSPACE; 1783 auio.uio_td = td; 1784 auio.uio_offset = 0; 1785 auio.uio_resid = buflen; 1786 1787 if ((ioflg & IO_NODELOCKED) == 0) { 1788 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) 1789 return (error); 1790 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1791 } 1792 1793 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 1794 1795 /* authorize attribute setting as kernel */ 1796 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, td); 1797 1798 if ((ioflg & IO_NODELOCKED) == 0) { 1799 vn_finished_write(mp); 1800 VOP_UNLOCK(vp, 0); 1801 } 1802 1803 return (error); 1804 } 1805 1806 int 1807 vn_extattr_rm(struct vnode *vp, int ioflg, int attrnamespace, 1808 const char *attrname, struct thread *td) 1809 { 1810 struct mount *mp; 1811 int error; 1812 1813 if ((ioflg & IO_NODELOCKED) == 0) { 1814 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) 1815 return (error); 1816 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1817 } 1818 1819 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 1820 1821 /* authorize attribute removal as kernel */ 1822 error = VOP_DELETEEXTATTR(vp, attrnamespace, attrname, NULL, td); 1823 if (error == EOPNOTSUPP) 1824 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, NULL, 1825 NULL, td); 1826 1827 if ((ioflg & IO_NODELOCKED) == 0) { 1828 vn_finished_write(mp); 1829 VOP_UNLOCK(vp, 0); 1830 } 1831 1832 return (error); 1833 } 1834 1835 int 1836 vn_vget_ino(struct vnode *vp, ino_t ino, int lkflags, struct vnode **rvp) 1837 { 1838 struct mount *mp; 1839 int ltype, error; 1840 1841 mp = vp->v_mount; 1842 ltype = VOP_ISLOCKED(vp); 1843 KASSERT(ltype == LK_EXCLUSIVE || ltype == LK_SHARED, 1844 ("vn_vget_ino: vp not locked")); 1845 error = vfs_busy(mp, MBF_NOWAIT); 1846 if (error != 0) { 1847 vfs_ref(mp); 1848 VOP_UNLOCK(vp, 0); 1849 error = vfs_busy(mp, 0); 1850 vn_lock(vp, ltype | LK_RETRY); 1851 vfs_rel(mp); 1852 if (error != 0) 1853 return (ENOENT); 1854 if (vp->v_iflag & VI_DOOMED) { 1855 vfs_unbusy(mp); 1856 return (ENOENT); 1857 } 1858 } 1859 VOP_UNLOCK(vp, 0); 1860 error = VFS_VGET(mp, ino, lkflags, rvp); 1861 vfs_unbusy(mp); 1862 vn_lock(vp, ltype | LK_RETRY); 1863 if (vp->v_iflag & VI_DOOMED) { 1864 if (error == 0) 1865 vput(*rvp); 1866 error = ENOENT; 1867 } 1868 return (error); 1869 } 1870 1871 int 1872 vn_rlimit_fsize(const struct vnode *vp, const struct uio *uio, 1873 const struct thread *td) 1874 { 1875 1876 if (vp->v_type != VREG || td == NULL) 1877 return (0); 1878 PROC_LOCK(td->td_proc); 1879 if ((uoff_t)uio->uio_offset + uio->uio_resid > 1880 lim_cur(td->td_proc, RLIMIT_FSIZE)) { 1881 kern_psignal(td->td_proc, SIGXFSZ); 1882 PROC_UNLOCK(td->td_proc); 1883 return (EFBIG); 1884 } 1885 PROC_UNLOCK(td->td_proc); 1886 return (0); 1887 } 1888 1889 int 1890 vn_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 1891 struct thread *td) 1892 { 1893 struct vnode *vp; 1894 int error, vfslocked; 1895 1896 vp = fp->f_vnode; 1897 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 1898 #ifdef AUDIT 1899 vn_lock(vp, LK_SHARED | LK_RETRY); 1900 AUDIT_ARG_VNODE1(vp); 1901 VOP_UNLOCK(vp, 0); 1902 #endif 1903 error = setfmode(td, active_cred, vp, mode); 1904 VFS_UNLOCK_GIANT(vfslocked); 1905 return (error); 1906 } 1907 1908 int 1909 vn_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 1910 struct thread *td) 1911 { 1912 struct vnode *vp; 1913 int error, vfslocked; 1914 1915 vp = fp->f_vnode; 1916 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 1917 #ifdef AUDIT 1918 vn_lock(vp, LK_SHARED | LK_RETRY); 1919 AUDIT_ARG_VNODE1(vp); 1920 VOP_UNLOCK(vp, 0); 1921 #endif 1922 error = setfown(td, active_cred, vp, uid, gid); 1923 VFS_UNLOCK_GIANT(vfslocked); 1924 return (error); 1925 } 1926 1927 void 1928 vn_pages_remove(struct vnode *vp, vm_pindex_t start, vm_pindex_t end) 1929 { 1930 vm_object_t object; 1931 1932 if ((object = vp->v_object) == NULL) 1933 return; 1934 VM_OBJECT_LOCK(object); 1935 vm_object_page_remove(object, start, end, 0); 1936 VM_OBJECT_UNLOCK(object); 1937 } 1938 1939 int 1940 vn_bmap_seekhole(struct vnode *vp, u_long cmd, off_t *off, struct ucred *cred) 1941 { 1942 struct vattr va; 1943 daddr_t bn, bnp; 1944 uint64_t bsize; 1945 off_t noff; 1946 int error; 1947 1948 KASSERT(cmd == FIOSEEKHOLE || cmd == FIOSEEKDATA, 1949 ("Wrong command %lu", cmd)); 1950 1951 if (vn_lock(vp, LK_SHARED) != 0) 1952 return (EBADF); 1953 if (vp->v_type != VREG) { 1954 error = ENOTTY; 1955 goto unlock; 1956 } 1957 error = VOP_GETATTR(vp, &va, cred); 1958 if (error != 0) 1959 goto unlock; 1960 noff = *off; 1961 if (noff >= va.va_size) { 1962 error = ENXIO; 1963 goto unlock; 1964 } 1965 bsize = vp->v_mount->mnt_stat.f_iosize; 1966 for (bn = noff / bsize; noff < va.va_size; bn++, noff += bsize) { 1967 error = VOP_BMAP(vp, bn, NULL, &bnp, NULL, NULL); 1968 if (error == EOPNOTSUPP) { 1969 error = ENOTTY; 1970 goto unlock; 1971 } 1972 if ((bnp == -1 && cmd == FIOSEEKHOLE) || 1973 (bnp != -1 && cmd == FIOSEEKDATA)) { 1974 noff = bn * bsize; 1975 if (noff < *off) 1976 noff = *off; 1977 goto unlock; 1978 } 1979 } 1980 if (noff > va.va_size) 1981 noff = va.va_size; 1982 /* noff == va.va_size. There is an implicit hole at the end of file. */ 1983 if (cmd == FIOSEEKDATA) 1984 error = ENXIO; 1985 unlock: 1986 VOP_UNLOCK(vp, 0); 1987 if (error == 0) 1988 *off = noff; 1989 return (error); 1990 }
Cache object: 0d774b00bac233e4cb9a8673c026f44a
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