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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("$FreeBSD$"); 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 (vp->v_type == VFIFO && VOP_ISLOCKED(vp) != LK_EXCLUSIVE) 258 vn_lock(vp, LK_UPGRADE | LK_RETRY); 259 if ((error = VOP_OPEN(vp, fmode, cred, td, fp)) != 0) 260 goto bad; 261 262 if (fmode & FWRITE) 263 VOP_ADD_WRITECOUNT(vp, 1); 264 *flagp = fmode; 265 ASSERT_VOP_LOCKED(vp, "vn_open_cred"); 266 if (!mpsafe) 267 VFS_UNLOCK_GIANT(vfslocked); 268 return (0); 269 bad: 270 NDFREE(ndp, NDF_ONLY_PNBUF); 271 vput(vp); 272 VFS_UNLOCK_GIANT(vfslocked); 273 *flagp = fmode; 274 ndp->ni_vp = NULL; 275 return (error); 276 } 277 278 /* 279 * Check for write permissions on the specified vnode. 280 * Prototype text segments cannot be written. 281 */ 282 int 283 vn_writechk(vp) 284 register struct vnode *vp; 285 { 286 287 ASSERT_VOP_LOCKED(vp, "vn_writechk"); 288 /* 289 * If there's shared text associated with 290 * the vnode, try to free it up once. If 291 * we fail, we can't allow writing. 292 */ 293 if (VOP_IS_TEXT(vp)) 294 return (ETXTBSY); 295 296 return (0); 297 } 298 299 /* 300 * Vnode close call 301 */ 302 int 303 vn_close(vp, flags, file_cred, td) 304 register struct vnode *vp; 305 int flags; 306 struct ucred *file_cred; 307 struct thread *td; 308 { 309 struct mount *mp; 310 int error, lock_flags; 311 312 if (vp->v_type != VFIFO && !(flags & FWRITE) && vp->v_mount != NULL && 313 vp->v_mount->mnt_kern_flag & MNTK_EXTENDED_SHARED) 314 lock_flags = LK_SHARED; 315 else 316 lock_flags = LK_EXCLUSIVE; 317 318 VFS_ASSERT_GIANT(vp->v_mount); 319 320 vn_start_write(vp, &mp, V_WAIT); 321 vn_lock(vp, lock_flags | LK_RETRY); 322 if (flags & FWRITE) { 323 VNASSERT(vp->v_writecount > 0, vp, 324 ("vn_close: negative writecount")); 325 VOP_ADD_WRITECOUNT(vp, -1); 326 } 327 error = VOP_CLOSE(vp, flags, file_cred, td); 328 vput(vp); 329 vn_finished_write(mp); 330 return (error); 331 } 332 333 /* 334 * Heuristic to detect sequential operation. 335 */ 336 static int 337 sequential_heuristic(struct uio *uio, struct file *fp) 338 { 339 340 if (atomic_load_acq_int(&(fp->f_flag)) & FRDAHEAD) 341 return (fp->f_seqcount << IO_SEQSHIFT); 342 343 /* 344 * Offset 0 is handled specially. open() sets f_seqcount to 1 so 345 * that the first I/O is normally considered to be slightly 346 * sequential. Seeking to offset 0 doesn't change sequentiality 347 * unless previous seeks have reduced f_seqcount to 0, in which 348 * case offset 0 is not special. 349 */ 350 if ((uio->uio_offset == 0 && fp->f_seqcount > 0) || 351 uio->uio_offset == fp->f_nextoff) { 352 /* 353 * f_seqcount is in units of fixed-size blocks so that it 354 * depends mainly on the amount of sequential I/O and not 355 * much on the number of sequential I/O's. The fixed size 356 * of 16384 is hard-coded here since it is (not quite) just 357 * a magic size that works well here. This size is more 358 * closely related to the best I/O size for real disks than 359 * to any block size used by software. 360 */ 361 fp->f_seqcount += howmany(uio->uio_resid, 16384); 362 if (fp->f_seqcount > IO_SEQMAX) 363 fp->f_seqcount = IO_SEQMAX; 364 return (fp->f_seqcount << IO_SEQSHIFT); 365 } 366 367 /* Not sequential. Quickly draw-down sequentiality. */ 368 if (fp->f_seqcount > 1) 369 fp->f_seqcount = 1; 370 else 371 fp->f_seqcount = 0; 372 return (0); 373 } 374 375 /* 376 * Package up an I/O request on a vnode into a uio and do it. 377 */ 378 int 379 vn_rdwr(enum uio_rw rw, struct vnode *vp, void *base, int len, off_t offset, 380 enum uio_seg segflg, int ioflg, struct ucred *active_cred, 381 struct ucred *file_cred, ssize_t *aresid, struct thread *td) 382 { 383 struct uio auio; 384 struct iovec aiov; 385 struct mount *mp; 386 struct ucred *cred; 387 void *rl_cookie; 388 int error, lock_flags; 389 390 VFS_ASSERT_GIANT(vp->v_mount); 391 392 auio.uio_iov = &aiov; 393 auio.uio_iovcnt = 1; 394 aiov.iov_base = base; 395 aiov.iov_len = len; 396 auio.uio_resid = len; 397 auio.uio_offset = offset; 398 auio.uio_segflg = segflg; 399 auio.uio_rw = rw; 400 auio.uio_td = td; 401 error = 0; 402 403 if ((ioflg & IO_NODELOCKED) == 0) { 404 if (rw == UIO_READ) { 405 rl_cookie = vn_rangelock_rlock(vp, offset, 406 offset + len); 407 } else { 408 rl_cookie = vn_rangelock_wlock(vp, offset, 409 offset + len); 410 } 411 mp = NULL; 412 if (rw == UIO_WRITE) { 413 if (vp->v_type != VCHR && 414 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) 415 != 0) 416 goto out; 417 if (MNT_SHARED_WRITES(mp) || 418 ((mp == NULL) && MNT_SHARED_WRITES(vp->v_mount))) 419 lock_flags = LK_SHARED; 420 else 421 lock_flags = LK_EXCLUSIVE; 422 } else 423 lock_flags = LK_SHARED; 424 vn_lock(vp, lock_flags | LK_RETRY); 425 } else 426 rl_cookie = NULL; 427 428 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 429 #ifdef MAC 430 if ((ioflg & IO_NOMACCHECK) == 0) { 431 if (rw == UIO_READ) 432 error = mac_vnode_check_read(active_cred, file_cred, 433 vp); 434 else 435 error = mac_vnode_check_write(active_cred, file_cred, 436 vp); 437 } 438 #endif 439 if (error == 0) { 440 if (file_cred != NULL) 441 cred = file_cred; 442 else 443 cred = active_cred; 444 if (rw == UIO_READ) 445 error = VOP_READ(vp, &auio, ioflg, cred); 446 else 447 error = VOP_WRITE(vp, &auio, ioflg, cred); 448 } 449 if (aresid) 450 *aresid = auio.uio_resid; 451 else 452 if (auio.uio_resid && error == 0) 453 error = EIO; 454 if ((ioflg & IO_NODELOCKED) == 0) { 455 VOP_UNLOCK(vp, 0); 456 if (mp != NULL) 457 vn_finished_write(mp); 458 } 459 out: 460 if (rl_cookie != NULL) 461 vn_rangelock_unlock(vp, rl_cookie); 462 return (error); 463 } 464 465 /* 466 * Package up an I/O request on a vnode into a uio and do it. The I/O 467 * request is split up into smaller chunks and we try to avoid saturating 468 * the buffer cache while potentially holding a vnode locked, so we 469 * check bwillwrite() before calling vn_rdwr(). We also call kern_yield() 470 * to give other processes a chance to lock the vnode (either other processes 471 * core'ing the same binary, or unrelated processes scanning the directory). 472 */ 473 int 474 vn_rdwr_inchunks(rw, vp, base, len, offset, segflg, ioflg, active_cred, 475 file_cred, aresid, td) 476 enum uio_rw rw; 477 struct vnode *vp; 478 void *base; 479 size_t len; 480 off_t offset; 481 enum uio_seg segflg; 482 int ioflg; 483 struct ucred *active_cred; 484 struct ucred *file_cred; 485 size_t *aresid; 486 struct thread *td; 487 { 488 int error = 0; 489 ssize_t iaresid; 490 491 VFS_ASSERT_GIANT(vp->v_mount); 492 493 do { 494 int chunk; 495 496 /* 497 * Force `offset' to a multiple of MAXBSIZE except possibly 498 * for the first chunk, so that filesystems only need to 499 * write full blocks except possibly for the first and last 500 * chunks. 501 */ 502 chunk = MAXBSIZE - (uoff_t)offset % MAXBSIZE; 503 504 if (chunk > len) 505 chunk = len; 506 if (rw != UIO_READ && vp->v_type == VREG) 507 bwillwrite(); 508 iaresid = 0; 509 error = vn_rdwr(rw, vp, base, chunk, offset, segflg, 510 ioflg, active_cred, file_cred, &iaresid, td); 511 len -= chunk; /* aresid calc already includes length */ 512 if (error) 513 break; 514 offset += chunk; 515 base = (char *)base + chunk; 516 kern_yield(PRI_USER); 517 } while (len); 518 if (aresid) 519 *aresid = len + iaresid; 520 return (error); 521 } 522 523 off_t 524 foffset_lock(struct file *fp, int flags) 525 { 526 struct mtx *mtxp; 527 off_t res; 528 529 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed")); 530 531 #if OFF_MAX <= LONG_MAX 532 /* 533 * Caller only wants the current f_offset value. Assume that 534 * the long and shorter integer types reads are atomic. 535 */ 536 if ((flags & FOF_NOLOCK) != 0) 537 return (fp->f_offset); 538 #endif 539 540 /* 541 * According to McKusick the vn lock was protecting f_offset here. 542 * It is now protected by the FOFFSET_LOCKED flag. 543 */ 544 mtxp = mtx_pool_find(mtxpool_sleep, fp); 545 mtx_lock(mtxp); 546 if ((flags & FOF_NOLOCK) == 0) { 547 while (fp->f_vnread_flags & FOFFSET_LOCKED) { 548 fp->f_vnread_flags |= FOFFSET_LOCK_WAITING; 549 msleep(&fp->f_vnread_flags, mtxp, PUSER -1, 550 "vofflock", 0); 551 } 552 fp->f_vnread_flags |= FOFFSET_LOCKED; 553 } 554 res = fp->f_offset; 555 mtx_unlock(mtxp); 556 return (res); 557 } 558 559 void 560 foffset_unlock(struct file *fp, off_t val, int flags) 561 { 562 struct mtx *mtxp; 563 564 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed")); 565 566 #if OFF_MAX <= LONG_MAX 567 if ((flags & FOF_NOLOCK) != 0) { 568 if ((flags & FOF_NOUPDATE) == 0) 569 fp->f_offset = val; 570 if ((flags & FOF_NEXTOFF) != 0) 571 fp->f_nextoff = val; 572 return; 573 } 574 #endif 575 576 mtxp = mtx_pool_find(mtxpool_sleep, fp); 577 mtx_lock(mtxp); 578 if ((flags & FOF_NOUPDATE) == 0) 579 fp->f_offset = val; 580 if ((flags & FOF_NEXTOFF) != 0) 581 fp->f_nextoff = val; 582 if ((flags & FOF_NOLOCK) == 0) { 583 KASSERT((fp->f_vnread_flags & FOFFSET_LOCKED) != 0, 584 ("Lost FOFFSET_LOCKED")); 585 if (fp->f_vnread_flags & FOFFSET_LOCK_WAITING) 586 wakeup(&fp->f_vnread_flags); 587 fp->f_vnread_flags = 0; 588 } 589 mtx_unlock(mtxp); 590 } 591 592 void 593 foffset_lock_uio(struct file *fp, struct uio *uio, int flags) 594 { 595 596 if ((flags & FOF_OFFSET) == 0) 597 uio->uio_offset = foffset_lock(fp, flags); 598 } 599 600 void 601 foffset_unlock_uio(struct file *fp, struct uio *uio, int flags) 602 { 603 604 if ((flags & FOF_OFFSET) == 0) 605 foffset_unlock(fp, uio->uio_offset, flags); 606 } 607 608 static int 609 get_advice(struct file *fp, struct uio *uio) 610 { 611 struct mtx *mtxp; 612 int ret; 613 614 ret = POSIX_FADV_NORMAL; 615 if (fp->f_advice == NULL) 616 return (ret); 617 618 mtxp = mtx_pool_find(mtxpool_sleep, fp); 619 mtx_lock(mtxp); 620 if (uio->uio_offset >= fp->f_advice->fa_start && 621 uio->uio_offset + uio->uio_resid <= fp->f_advice->fa_end) 622 ret = fp->f_advice->fa_advice; 623 mtx_unlock(mtxp); 624 return (ret); 625 } 626 627 /* 628 * File table vnode read routine. 629 */ 630 static int 631 vn_read(fp, uio, active_cred, flags, td) 632 struct file *fp; 633 struct uio *uio; 634 struct ucred *active_cred; 635 int flags; 636 struct thread *td; 637 { 638 struct vnode *vp; 639 struct mtx *mtxp; 640 int error, ioflag; 641 int advice, vfslocked; 642 off_t offset, start, end; 643 644 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", 645 uio->uio_td, td)); 646 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET")); 647 vp = fp->f_vnode; 648 ioflag = 0; 649 if (fp->f_flag & FNONBLOCK) 650 ioflag |= IO_NDELAY; 651 if (fp->f_flag & O_DIRECT) 652 ioflag |= IO_DIRECT; 653 advice = get_advice(fp, uio); 654 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 655 vn_lock(vp, LK_SHARED | LK_RETRY); 656 657 switch (advice) { 658 case POSIX_FADV_NORMAL: 659 case POSIX_FADV_SEQUENTIAL: 660 case POSIX_FADV_NOREUSE: 661 ioflag |= sequential_heuristic(uio, fp); 662 break; 663 case POSIX_FADV_RANDOM: 664 /* Disable read-ahead for random I/O. */ 665 break; 666 } 667 offset = uio->uio_offset; 668 669 #ifdef MAC 670 error = mac_vnode_check_read(active_cred, fp->f_cred, vp); 671 if (error == 0) 672 #endif 673 error = VOP_READ(vp, uio, ioflag, fp->f_cred); 674 fp->f_nextoff = uio->uio_offset; 675 VOP_UNLOCK(vp, 0); 676 if (error == 0 && advice == POSIX_FADV_NOREUSE && 677 offset != uio->uio_offset) { 678 /* 679 * Use POSIX_FADV_DONTNEED to flush clean pages and 680 * buffers for the backing file after a 681 * POSIX_FADV_NOREUSE read(2). To optimize the common 682 * case of using POSIX_FADV_NOREUSE with sequential 683 * access, track the previous implicit DONTNEED 684 * request and grow this request to include the 685 * current read(2) in addition to the previous 686 * DONTNEED. With purely sequential access this will 687 * cause the DONTNEED requests to continously grow to 688 * cover all of the previously read regions of the 689 * file. This allows filesystem blocks that are 690 * accessed by multiple calls to read(2) to be flushed 691 * once the last read(2) finishes. 692 */ 693 start = offset; 694 end = uio->uio_offset - 1; 695 mtxp = mtx_pool_find(mtxpool_sleep, fp); 696 mtx_lock(mtxp); 697 if (fp->f_advice != NULL && 698 fp->f_advice->fa_advice == POSIX_FADV_NOREUSE) { 699 if (start != 0 && fp->f_advice->fa_prevend + 1 == start) 700 start = fp->f_advice->fa_prevstart; 701 else if (fp->f_advice->fa_prevstart != 0 && 702 fp->f_advice->fa_prevstart == end + 1) 703 end = fp->f_advice->fa_prevend; 704 fp->f_advice->fa_prevstart = start; 705 fp->f_advice->fa_prevend = end; 706 } 707 mtx_unlock(mtxp); 708 error = VOP_ADVISE(vp, start, end, POSIX_FADV_DONTNEED); 709 } 710 VFS_UNLOCK_GIANT(vfslocked); 711 return (error); 712 } 713 714 /* 715 * File table vnode write routine. 716 */ 717 static int 718 vn_write(fp, uio, active_cred, flags, td) 719 struct file *fp; 720 struct uio *uio; 721 struct ucred *active_cred; 722 int flags; 723 struct thread *td; 724 { 725 struct vnode *vp; 726 struct mount *mp; 727 struct mtx *mtxp; 728 int error, ioflag, lock_flags; 729 int advice, vfslocked; 730 off_t offset, start, end; 731 732 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", 733 uio->uio_td, td)); 734 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET")); 735 vp = fp->f_vnode; 736 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 737 if (vp->v_type == VREG) 738 bwillwrite(); 739 ioflag = IO_UNIT; 740 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 741 ioflag |= IO_APPEND; 742 if (fp->f_flag & FNONBLOCK) 743 ioflag |= IO_NDELAY; 744 if (fp->f_flag & O_DIRECT) 745 ioflag |= IO_DIRECT; 746 if ((fp->f_flag & O_FSYNC) || 747 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS))) 748 ioflag |= IO_SYNC; 749 mp = NULL; 750 if (vp->v_type != VCHR && 751 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0) 752 goto unlock; 753 754 advice = get_advice(fp, uio); 755 756 if ((MNT_SHARED_WRITES(mp) || 757 ((mp == NULL) && MNT_SHARED_WRITES(vp->v_mount))) && 758 (flags & FOF_OFFSET) != 0) { 759 lock_flags = LK_SHARED; 760 } else { 761 lock_flags = LK_EXCLUSIVE; 762 } 763 764 vn_lock(vp, lock_flags | LK_RETRY); 765 switch (advice) { 766 case POSIX_FADV_NORMAL: 767 case POSIX_FADV_SEQUENTIAL: 768 case POSIX_FADV_NOREUSE: 769 ioflag |= sequential_heuristic(uio, fp); 770 break; 771 case POSIX_FADV_RANDOM: 772 /* XXX: Is this correct? */ 773 break; 774 } 775 offset = uio->uio_offset; 776 777 #ifdef MAC 778 error = mac_vnode_check_write(active_cred, fp->f_cred, vp); 779 if (error == 0) 780 #endif 781 error = VOP_WRITE(vp, uio, ioflag, fp->f_cred); 782 fp->f_nextoff = uio->uio_offset; 783 VOP_UNLOCK(vp, 0); 784 if (vp->v_type != VCHR) 785 vn_finished_write(mp); 786 if (error == 0 && advice == POSIX_FADV_NOREUSE && 787 offset != uio->uio_offset) { 788 /* 789 * Use POSIX_FADV_DONTNEED to flush clean pages and 790 * buffers for the backing file after a 791 * POSIX_FADV_NOREUSE write(2). To optimize the 792 * common case of using POSIX_FADV_NOREUSE with 793 * sequential access, track the previous implicit 794 * DONTNEED request and grow this request to include 795 * the current write(2) in addition to the previous 796 * DONTNEED. With purely sequential access this will 797 * cause the DONTNEED requests to continously grow to 798 * cover all of the previously written regions of the 799 * file. 800 * 801 * Note that the blocks just written are almost 802 * certainly still dirty, so this only works when 803 * VOP_ADVISE() calls from subsequent writes push out 804 * the data written by this write(2) once the backing 805 * buffers are clean. However, as compared to forcing 806 * IO_DIRECT, this gives much saner behavior. Write 807 * clustering is still allowed, and clean pages are 808 * merely moved to the cache page queue rather than 809 * outright thrown away. This means a subsequent 810 * read(2) can still avoid hitting the disk if the 811 * pages have not been reclaimed. 812 * 813 * This does make POSIX_FADV_NOREUSE largely useless 814 * with non-sequential access. However, sequential 815 * access is the more common use case and the flag is 816 * merely advisory. 817 */ 818 start = offset; 819 end = uio->uio_offset - 1; 820 mtxp = mtx_pool_find(mtxpool_sleep, fp); 821 mtx_lock(mtxp); 822 if (fp->f_advice != NULL && 823 fp->f_advice->fa_advice == POSIX_FADV_NOREUSE) { 824 if (start != 0 && fp->f_advice->fa_prevend + 1 == start) 825 start = fp->f_advice->fa_prevstart; 826 else if (fp->f_advice->fa_prevstart != 0 && 827 fp->f_advice->fa_prevstart == end + 1) 828 end = fp->f_advice->fa_prevend; 829 fp->f_advice->fa_prevstart = start; 830 fp->f_advice->fa_prevend = end; 831 } 832 mtx_unlock(mtxp); 833 error = VOP_ADVISE(vp, start, end, POSIX_FADV_DONTNEED); 834 } 835 836 unlock: 837 VFS_UNLOCK_GIANT(vfslocked); 838 return (error); 839 } 840 841 static const int io_hold_cnt = 16; 842 static int vn_io_fault_enable = 0; 843 SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_enable, CTLFLAG_RW, 844 &vn_io_fault_enable, 0, "Enable vn_io_fault lock avoidance"); 845 static u_long vn_io_faults_cnt; 846 SYSCTL_ULONG(_debug, OID_AUTO, vn_io_faults, CTLFLAG_RD, 847 &vn_io_faults_cnt, 0, "Count of vn_io_fault lock avoidance triggers"); 848 849 /* 850 * The vn_io_fault() is a wrapper around vn_read() and vn_write() to 851 * prevent the following deadlock: 852 * 853 * Assume that the thread A reads from the vnode vp1 into userspace 854 * buffer buf1 backed by the pages of vnode vp2. If a page in buf1 is 855 * currently not resident, then system ends up with the call chain 856 * vn_read() -> VOP_READ(vp1) -> uiomove() -> [Page Fault] -> 857 * vm_fault(buf1) -> vnode_pager_getpages(vp2) -> VOP_GETPAGES(vp2) 858 * which establishes lock order vp1->vn_lock, then vp2->vn_lock. 859 * If, at the same time, thread B reads from vnode vp2 into buffer buf2 860 * backed by the pages of vnode vp1, and some page in buf2 is not 861 * resident, we get a reversed order vp2->vn_lock, then vp1->vn_lock. 862 * 863 * To prevent the lock order reversal and deadlock, vn_io_fault() does 864 * not allow page faults to happen during VOP_READ() or VOP_WRITE(). 865 * Instead, it first tries to do the whole range i/o with pagefaults 866 * disabled. If all pages in the i/o buffer are resident and mapped, 867 * VOP will succeed (ignoring the genuine filesystem errors). 868 * Otherwise, we get back EFAULT, and vn_io_fault() falls back to do 869 * i/o in chunks, with all pages in the chunk prefaulted and held 870 * using vm_fault_quick_hold_pages(). 871 * 872 * Filesystems using this deadlock avoidance scheme should use the 873 * array of the held pages from uio, saved in the curthread->td_ma, 874 * instead of doing uiomove(). A helper function 875 * vn_io_fault_uiomove() converts uiomove request into 876 * uiomove_fromphys() over td_ma array. 877 * 878 * Since vnode locks do not cover the whole i/o anymore, rangelocks 879 * make the current i/o request atomic with respect to other i/os and 880 * truncations. 881 */ 882 static int 883 vn_io_fault(struct file *fp, struct uio *uio, struct ucred *active_cred, 884 int flags, struct thread *td) 885 { 886 vm_page_t ma[io_hold_cnt + 2]; 887 struct uio *uio_clone, short_uio; 888 struct iovec short_iovec[1]; 889 fo_rdwr_t *doio; 890 struct vnode *vp; 891 void *rl_cookie; 892 struct mount *mp; 893 vm_page_t *prev_td_ma; 894 int error, cnt, save, saveheld, prev_td_ma_cnt; 895 vm_offset_t addr, end; 896 vm_prot_t prot; 897 size_t len, resid; 898 ssize_t adv; 899 900 if (uio->uio_rw == UIO_READ) 901 doio = vn_read; 902 else 903 doio = vn_write; 904 vp = fp->f_vnode; 905 foffset_lock_uio(fp, uio, flags); 906 907 if (uio->uio_segflg != UIO_USERSPACE || vp->v_type != VREG || 908 ((mp = vp->v_mount) != NULL && 909 (mp->mnt_kern_flag & MNTK_NO_IOPF) == 0) || 910 !vn_io_fault_enable) { 911 error = doio(fp, uio, active_cred, flags | FOF_OFFSET, td); 912 goto out_last; 913 } 914 915 /* 916 * The UFS follows IO_UNIT directive and replays back both 917 * uio_offset and uio_resid if an error is encountered during the 918 * operation. But, since the iovec may be already advanced, 919 * uio is still in an inconsistent state. 920 * 921 * Cache a copy of the original uio, which is advanced to the redo 922 * point using UIO_NOCOPY below. 923 */ 924 uio_clone = cloneuio(uio); 925 resid = uio->uio_resid; 926 927 short_uio.uio_segflg = UIO_USERSPACE; 928 short_uio.uio_rw = uio->uio_rw; 929 short_uio.uio_td = uio->uio_td; 930 931 if (uio->uio_rw == UIO_READ) { 932 prot = VM_PROT_WRITE; 933 rl_cookie = vn_rangelock_rlock(vp, uio->uio_offset, 934 uio->uio_offset + uio->uio_resid); 935 } else { 936 prot = VM_PROT_READ; 937 if ((fp->f_flag & O_APPEND) != 0 || (flags & FOF_OFFSET) == 0) 938 /* For appenders, punt and lock the whole range. */ 939 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 940 else 941 rl_cookie = vn_rangelock_wlock(vp, uio->uio_offset, 942 uio->uio_offset + uio->uio_resid); 943 } 944 945 save = vm_fault_disable_pagefaults(); 946 error = doio(fp, uio, active_cred, flags | FOF_OFFSET, td); 947 if (error != EFAULT) 948 goto out; 949 950 atomic_add_long(&vn_io_faults_cnt, 1); 951 uio_clone->uio_segflg = UIO_NOCOPY; 952 uiomove(NULL, resid - uio->uio_resid, uio_clone); 953 uio_clone->uio_segflg = uio->uio_segflg; 954 955 saveheld = curthread_pflags_set(TDP_UIOHELD); 956 prev_td_ma = td->td_ma; 957 prev_td_ma_cnt = td->td_ma_cnt; 958 959 while (uio_clone->uio_resid != 0) { 960 len = uio_clone->uio_iov->iov_len; 961 if (len == 0) { 962 KASSERT(uio_clone->uio_iovcnt >= 1, 963 ("iovcnt underflow")); 964 uio_clone->uio_iov++; 965 uio_clone->uio_iovcnt--; 966 continue; 967 } 968 if (len > io_hold_cnt * PAGE_SIZE) 969 len = io_hold_cnt * PAGE_SIZE; 970 addr = (uintptr_t)uio_clone->uio_iov->iov_base; 971 end = round_page(addr + len); 972 if (end < addr) { 973 error = EFAULT; 974 break; 975 } 976 cnt = atop(end - trunc_page(addr)); 977 /* 978 * A perfectly misaligned address and length could cause 979 * both the start and the end of the chunk to use partial 980 * page. +2 accounts for such a situation. 981 */ 982 cnt = vm_fault_quick_hold_pages(&td->td_proc->p_vmspace->vm_map, 983 addr, len, prot, ma, io_hold_cnt + 2); 984 if (cnt == -1) { 985 error = EFAULT; 986 break; 987 } 988 short_uio.uio_iov = &short_iovec[0]; 989 short_iovec[0].iov_base = (void *)addr; 990 short_uio.uio_iovcnt = 1; 991 short_uio.uio_resid = short_iovec[0].iov_len = len; 992 short_uio.uio_offset = uio_clone->uio_offset; 993 td->td_ma = ma; 994 td->td_ma_cnt = cnt; 995 996 error = doio(fp, &short_uio, active_cred, flags | FOF_OFFSET, 997 td); 998 vm_page_unhold_pages(ma, cnt); 999 adv = len - short_uio.uio_resid; 1000 1001 uio_clone->uio_iov->iov_base = 1002 (char *)uio_clone->uio_iov->iov_base + adv; 1003 uio_clone->uio_iov->iov_len -= adv; 1004 uio_clone->uio_resid -= adv; 1005 uio_clone->uio_offset += adv; 1006 1007 uio->uio_resid -= adv; 1008 uio->uio_offset += adv; 1009 1010 if (error != 0 || adv == 0) 1011 break; 1012 } 1013 td->td_ma = prev_td_ma; 1014 td->td_ma_cnt = prev_td_ma_cnt; 1015 curthread_pflags_restore(saveheld); 1016 out: 1017 vm_fault_enable_pagefaults(save); 1018 vn_rangelock_unlock(vp, rl_cookie); 1019 free(uio_clone, M_IOV); 1020 out_last: 1021 foffset_unlock_uio(fp, uio, flags); 1022 return (error); 1023 } 1024 1025 /* 1026 * Helper function to perform the requested uiomove operation using 1027 * the held pages for io->uio_iov[0].iov_base buffer instead of 1028 * copyin/copyout. Access to the pages with uiomove_fromphys() 1029 * instead of iov_base prevents page faults that could occur due to 1030 * pmap_collect() invalidating the mapping created by 1031 * vm_fault_quick_hold_pages(), or pageout daemon, page laundry or 1032 * object cleanup revoking the write access from page mappings. 1033 * 1034 * Filesystems specified MNTK_NO_IOPF shall use vn_io_fault_uiomove() 1035 * instead of plain uiomove(). 1036 */ 1037 int 1038 vn_io_fault_uiomove(char *data, int xfersize, struct uio *uio) 1039 { 1040 struct uio transp_uio; 1041 struct iovec transp_iov[1]; 1042 struct thread *td; 1043 size_t adv; 1044 int error, pgadv; 1045 1046 td = curthread; 1047 if ((td->td_pflags & TDP_UIOHELD) == 0 || 1048 uio->uio_segflg != UIO_USERSPACE) 1049 return (uiomove(data, xfersize, uio)); 1050 1051 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt)); 1052 transp_iov[0].iov_base = data; 1053 transp_uio.uio_iov = &transp_iov[0]; 1054 transp_uio.uio_iovcnt = 1; 1055 if (xfersize > uio->uio_resid) 1056 xfersize = uio->uio_resid; 1057 transp_uio.uio_resid = transp_iov[0].iov_len = xfersize; 1058 transp_uio.uio_offset = 0; 1059 transp_uio.uio_segflg = UIO_SYSSPACE; 1060 /* 1061 * Since transp_iov points to data, and td_ma page array 1062 * corresponds to original uio->uio_iov, we need to invert the 1063 * direction of the i/o operation as passed to 1064 * uiomove_fromphys(). 1065 */ 1066 switch (uio->uio_rw) { 1067 case UIO_WRITE: 1068 transp_uio.uio_rw = UIO_READ; 1069 break; 1070 case UIO_READ: 1071 transp_uio.uio_rw = UIO_WRITE; 1072 break; 1073 } 1074 transp_uio.uio_td = uio->uio_td; 1075 error = uiomove_fromphys(td->td_ma, 1076 ((vm_offset_t)uio->uio_iov->iov_base) & PAGE_MASK, 1077 xfersize, &transp_uio); 1078 adv = xfersize - transp_uio.uio_resid; 1079 pgadv = 1080 (((vm_offset_t)uio->uio_iov->iov_base + adv) >> PAGE_SHIFT) - 1081 (((vm_offset_t)uio->uio_iov->iov_base) >> PAGE_SHIFT); 1082 td->td_ma += pgadv; 1083 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt, 1084 pgadv)); 1085 td->td_ma_cnt -= pgadv; 1086 uio->uio_iov->iov_base = (char *)uio->uio_iov->iov_base + adv; 1087 uio->uio_iov->iov_len -= adv; 1088 uio->uio_resid -= adv; 1089 uio->uio_offset += adv; 1090 return (error); 1091 } 1092 1093 int 1094 vn_io_fault_pgmove(vm_page_t ma[], vm_offset_t offset, int xfersize, 1095 struct uio *uio) 1096 { 1097 struct thread *td; 1098 vm_offset_t iov_base; 1099 int cnt, pgadv; 1100 1101 td = curthread; 1102 if ((td->td_pflags & TDP_UIOHELD) == 0 || 1103 uio->uio_segflg != UIO_USERSPACE) 1104 return (uiomove_fromphys(ma, offset, xfersize, uio)); 1105 1106 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt)); 1107 cnt = xfersize > uio->uio_resid ? uio->uio_resid : xfersize; 1108 iov_base = (vm_offset_t)uio->uio_iov->iov_base; 1109 switch (uio->uio_rw) { 1110 case UIO_WRITE: 1111 pmap_copy_pages(td->td_ma, iov_base & PAGE_MASK, ma, 1112 offset, cnt); 1113 break; 1114 case UIO_READ: 1115 pmap_copy_pages(ma, offset, td->td_ma, iov_base & PAGE_MASK, 1116 cnt); 1117 break; 1118 } 1119 pgadv = ((iov_base + cnt) >> PAGE_SHIFT) - (iov_base >> PAGE_SHIFT); 1120 td->td_ma += pgadv; 1121 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt, 1122 pgadv)); 1123 td->td_ma_cnt -= pgadv; 1124 uio->uio_iov->iov_base = (char *)(iov_base + cnt); 1125 uio->uio_iov->iov_len -= cnt; 1126 uio->uio_resid -= cnt; 1127 uio->uio_offset += cnt; 1128 return (0); 1129 } 1130 1131 1132 /* 1133 * File table truncate routine. 1134 */ 1135 static int 1136 vn_truncate(struct file *fp, off_t length, struct ucred *active_cred, 1137 struct thread *td) 1138 { 1139 struct vattr vattr; 1140 struct mount *mp; 1141 struct vnode *vp; 1142 void *rl_cookie; 1143 int vfslocked; 1144 int error; 1145 1146 vp = fp->f_vnode; 1147 1148 /* 1149 * Lock the whole range for truncation. Otherwise split i/o 1150 * might happen partly before and partly after the truncation. 1151 */ 1152 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 1153 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 1154 error = vn_start_write(vp, &mp, V_WAIT | PCATCH); 1155 if (error) 1156 goto out1; 1157 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1158 if (vp->v_type == VDIR) { 1159 error = EISDIR; 1160 goto out; 1161 } 1162 #ifdef MAC 1163 error = mac_vnode_check_write(active_cred, fp->f_cred, vp); 1164 if (error) 1165 goto out; 1166 #endif 1167 error = vn_writechk(vp); 1168 if (error == 0) { 1169 VATTR_NULL(&vattr); 1170 vattr.va_size = length; 1171 error = VOP_SETATTR(vp, &vattr, fp->f_cred); 1172 } 1173 out: 1174 VOP_UNLOCK(vp, 0); 1175 vn_finished_write(mp); 1176 out1: 1177 VFS_UNLOCK_GIANT(vfslocked); 1178 vn_rangelock_unlock(vp, rl_cookie); 1179 return (error); 1180 } 1181 1182 /* 1183 * File table vnode stat routine. 1184 */ 1185 static int 1186 vn_statfile(fp, sb, active_cred, td) 1187 struct file *fp; 1188 struct stat *sb; 1189 struct ucred *active_cred; 1190 struct thread *td; 1191 { 1192 struct vnode *vp = fp->f_vnode; 1193 int vfslocked; 1194 int error; 1195 1196 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 1197 vn_lock(vp, LK_SHARED | LK_RETRY); 1198 error = vn_stat(vp, sb, active_cred, fp->f_cred, td); 1199 VOP_UNLOCK(vp, 0); 1200 VFS_UNLOCK_GIANT(vfslocked); 1201 1202 return (error); 1203 } 1204 1205 /* 1206 * Stat a vnode; implementation for the stat syscall 1207 */ 1208 int 1209 vn_stat(vp, sb, active_cred, file_cred, td) 1210 struct vnode *vp; 1211 register struct stat *sb; 1212 struct ucred *active_cred; 1213 struct ucred *file_cred; 1214 struct thread *td; 1215 { 1216 struct vattr vattr; 1217 register struct vattr *vap; 1218 int error; 1219 u_short mode; 1220 1221 #ifdef MAC 1222 error = mac_vnode_check_stat(active_cred, file_cred, vp); 1223 if (error) 1224 return (error); 1225 #endif 1226 1227 vap = &vattr; 1228 1229 /* 1230 * Initialize defaults for new and unusual fields, so that file 1231 * systems which don't support these fields don't need to know 1232 * about them. 1233 */ 1234 vap->va_birthtime.tv_sec = -1; 1235 vap->va_birthtime.tv_nsec = 0; 1236 vap->va_fsid = VNOVAL; 1237 vap->va_rdev = NODEV; 1238 1239 error = VOP_GETATTR(vp, vap, active_cred); 1240 if (error) 1241 return (error); 1242 1243 /* 1244 * Zero the spare stat fields 1245 */ 1246 bzero(sb, sizeof *sb); 1247 1248 /* 1249 * Copy from vattr table 1250 */ 1251 if (vap->va_fsid != VNOVAL) 1252 sb->st_dev = vap->va_fsid; 1253 else 1254 sb->st_dev = vp->v_mount->mnt_stat.f_fsid.val[0]; 1255 sb->st_ino = vap->va_fileid; 1256 mode = vap->va_mode; 1257 switch (vap->va_type) { 1258 case VREG: 1259 mode |= S_IFREG; 1260 break; 1261 case VDIR: 1262 mode |= S_IFDIR; 1263 break; 1264 case VBLK: 1265 mode |= S_IFBLK; 1266 break; 1267 case VCHR: 1268 mode |= S_IFCHR; 1269 break; 1270 case VLNK: 1271 mode |= S_IFLNK; 1272 break; 1273 case VSOCK: 1274 mode |= S_IFSOCK; 1275 break; 1276 case VFIFO: 1277 mode |= S_IFIFO; 1278 break; 1279 default: 1280 return (EBADF); 1281 }; 1282 sb->st_mode = mode; 1283 sb->st_nlink = vap->va_nlink; 1284 sb->st_uid = vap->va_uid; 1285 sb->st_gid = vap->va_gid; 1286 sb->st_rdev = vap->va_rdev; 1287 if (vap->va_size > OFF_MAX) 1288 return (EOVERFLOW); 1289 sb->st_size = vap->va_size; 1290 sb->st_atim = vap->va_atime; 1291 sb->st_mtim = vap->va_mtime; 1292 sb->st_ctim = vap->va_ctime; 1293 sb->st_birthtim = vap->va_birthtime; 1294 1295 /* 1296 * According to www.opengroup.org, the meaning of st_blksize is 1297 * "a filesystem-specific preferred I/O block size for this 1298 * object. In some filesystem types, this may vary from file 1299 * to file" 1300 * Use miminum/default of PAGE_SIZE (e.g. for VCHR). 1301 */ 1302 1303 sb->st_blksize = max(PAGE_SIZE, vap->va_blocksize); 1304 1305 sb->st_flags = vap->va_flags; 1306 if (priv_check(td, PRIV_VFS_GENERATION)) 1307 sb->st_gen = 0; 1308 else 1309 sb->st_gen = vap->va_gen; 1310 1311 sb->st_blocks = vap->va_bytes / S_BLKSIZE; 1312 return (0); 1313 } 1314 1315 /* 1316 * File table vnode ioctl routine. 1317 */ 1318 static int 1319 vn_ioctl(fp, com, data, active_cred, td) 1320 struct file *fp; 1321 u_long com; 1322 void *data; 1323 struct ucred *active_cred; 1324 struct thread *td; 1325 { 1326 struct vnode *vp = fp->f_vnode; 1327 struct vattr vattr; 1328 int vfslocked; 1329 int error; 1330 1331 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 1332 error = ENOTTY; 1333 switch (vp->v_type) { 1334 case VREG: 1335 case VDIR: 1336 if (com == FIONREAD) { 1337 vn_lock(vp, LK_SHARED | LK_RETRY); 1338 error = VOP_GETATTR(vp, &vattr, active_cred); 1339 VOP_UNLOCK(vp, 0); 1340 if (!error) 1341 *(int *)data = vattr.va_size - fp->f_offset; 1342 } else if (com == FIONBIO || com == FIOASYNC) /* XXX */ 1343 error = 0; 1344 else 1345 error = VOP_IOCTL(vp, com, data, fp->f_flag, 1346 active_cred, td); 1347 break; 1348 1349 default: 1350 break; 1351 } 1352 VFS_UNLOCK_GIANT(vfslocked); 1353 return (error); 1354 } 1355 1356 /* 1357 * File table vnode poll routine. 1358 */ 1359 static int 1360 vn_poll(fp, events, active_cred, td) 1361 struct file *fp; 1362 int events; 1363 struct ucred *active_cred; 1364 struct thread *td; 1365 { 1366 struct vnode *vp; 1367 int vfslocked; 1368 int error; 1369 1370 vp = fp->f_vnode; 1371 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 1372 #ifdef MAC 1373 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1374 error = mac_vnode_check_poll(active_cred, fp->f_cred, vp); 1375 VOP_UNLOCK(vp, 0); 1376 if (!error) 1377 #endif 1378 1379 error = VOP_POLL(vp, events, fp->f_cred, td); 1380 VFS_UNLOCK_GIANT(vfslocked); 1381 return (error); 1382 } 1383 1384 /* 1385 * Acquire the requested lock and then check for validity. LK_RETRY 1386 * permits vn_lock to return doomed vnodes. 1387 */ 1388 int 1389 _vn_lock(struct vnode *vp, int flags, char *file, int line) 1390 { 1391 int error; 1392 1393 VNASSERT((flags & LK_TYPE_MASK) != 0, vp, 1394 ("vn_lock called with no locktype.")); 1395 do { 1396 #ifdef DEBUG_VFS_LOCKS 1397 KASSERT(vp->v_holdcnt != 0, 1398 ("vn_lock %p: zero hold count", vp)); 1399 #endif 1400 error = VOP_LOCK1(vp, flags, file, line); 1401 flags &= ~LK_INTERLOCK; /* Interlock is always dropped. */ 1402 KASSERT((flags & LK_RETRY) == 0 || error == 0, 1403 ("LK_RETRY set with incompatible flags (0x%x) or an error occured (%d)", 1404 flags, error)); 1405 /* 1406 * Callers specify LK_RETRY if they wish to get dead vnodes. 1407 * If RETRY is not set, we return ENOENT instead. 1408 */ 1409 if (error == 0 && vp->v_iflag & VI_DOOMED && 1410 (flags & LK_RETRY) == 0) { 1411 VOP_UNLOCK(vp, 0); 1412 error = ENOENT; 1413 break; 1414 } 1415 } while (flags & LK_RETRY && error != 0); 1416 return (error); 1417 } 1418 1419 /* 1420 * File table vnode close routine. 1421 */ 1422 static int 1423 vn_closefile(fp, td) 1424 struct file *fp; 1425 struct thread *td; 1426 { 1427 struct vnode *vp; 1428 struct flock lf; 1429 int vfslocked; 1430 int error; 1431 1432 vp = fp->f_vnode; 1433 1434 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 1435 if (fp->f_type == DTYPE_VNODE && fp->f_flag & FHASLOCK) { 1436 lf.l_whence = SEEK_SET; 1437 lf.l_start = 0; 1438 lf.l_len = 0; 1439 lf.l_type = F_UNLCK; 1440 (void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, F_FLOCK); 1441 } 1442 1443 fp->f_ops = &badfileops; 1444 1445 error = vn_close(vp, fp->f_flag, fp->f_cred, td); 1446 VFS_UNLOCK_GIANT(vfslocked); 1447 return (error); 1448 } 1449 1450 /* 1451 * Preparing to start a filesystem write operation. If the operation is 1452 * permitted, then we bump the count of operations in progress and 1453 * proceed. If a suspend request is in progress, we wait until the 1454 * suspension is over, and then proceed. 1455 */ 1456 static int 1457 vn_start_write_locked(struct mount *mp, int flags) 1458 { 1459 int error; 1460 1461 mtx_assert(MNT_MTX(mp), MA_OWNED); 1462 error = 0; 1463 1464 /* 1465 * Check on status of suspension. 1466 */ 1467 if ((curthread->td_pflags & TDP_IGNSUSP) == 0 || 1468 mp->mnt_susp_owner != curthread) { 1469 while ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { 1470 if (flags & V_NOWAIT) { 1471 error = EWOULDBLOCK; 1472 goto unlock; 1473 } 1474 error = msleep(&mp->mnt_flag, MNT_MTX(mp), 1475 (PUSER - 1) | (flags & PCATCH), "suspfs", 0); 1476 if (error) 1477 goto unlock; 1478 } 1479 } 1480 if (flags & V_XSLEEP) 1481 goto unlock; 1482 mp->mnt_writeopcount++; 1483 unlock: 1484 if (error != 0 || (flags & V_XSLEEP) != 0) 1485 MNT_REL(mp); 1486 MNT_IUNLOCK(mp); 1487 return (error); 1488 } 1489 1490 int 1491 vn_start_write(vp, mpp, flags) 1492 struct vnode *vp; 1493 struct mount **mpp; 1494 int flags; 1495 { 1496 struct mount *mp; 1497 int error; 1498 1499 error = 0; 1500 /* 1501 * If a vnode is provided, get and return the mount point that 1502 * to which it will write. 1503 */ 1504 if (vp != NULL) { 1505 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) { 1506 *mpp = NULL; 1507 if (error != EOPNOTSUPP) 1508 return (error); 1509 return (0); 1510 } 1511 } 1512 if ((mp = *mpp) == NULL) 1513 return (0); 1514 1515 /* 1516 * VOP_GETWRITEMOUNT() returns with the mp refcount held through 1517 * a vfs_ref(). 1518 * As long as a vnode is not provided we need to acquire a 1519 * refcount for the provided mountpoint too, in order to 1520 * emulate a vfs_ref(). 1521 */ 1522 MNT_ILOCK(mp); 1523 if (vp == NULL) 1524 MNT_REF(mp); 1525 1526 return (vn_start_write_locked(mp, flags)); 1527 } 1528 1529 /* 1530 * Secondary suspension. Used by operations such as vop_inactive 1531 * routines that are needed by the higher level functions. These 1532 * are allowed to proceed until all the higher level functions have 1533 * completed (indicated by mnt_writeopcount dropping to zero). At that 1534 * time, these operations are halted until the suspension is over. 1535 */ 1536 int 1537 vn_start_secondary_write(vp, mpp, flags) 1538 struct vnode *vp; 1539 struct mount **mpp; 1540 int flags; 1541 { 1542 struct mount *mp; 1543 int error; 1544 1545 retry: 1546 if (vp != NULL) { 1547 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) { 1548 *mpp = NULL; 1549 if (error != EOPNOTSUPP) 1550 return (error); 1551 return (0); 1552 } 1553 } 1554 /* 1555 * If we are not suspended or have not yet reached suspended 1556 * mode, then let the operation proceed. 1557 */ 1558 if ((mp = *mpp) == NULL) 1559 return (0); 1560 1561 /* 1562 * VOP_GETWRITEMOUNT() returns with the mp refcount held through 1563 * a vfs_ref(). 1564 * As long as a vnode is not provided we need to acquire a 1565 * refcount for the provided mountpoint too, in order to 1566 * emulate a vfs_ref(). 1567 */ 1568 MNT_ILOCK(mp); 1569 if (vp == NULL) 1570 MNT_REF(mp); 1571 if ((mp->mnt_kern_flag & (MNTK_SUSPENDED | MNTK_SUSPEND2)) == 0) { 1572 mp->mnt_secondary_writes++; 1573 mp->mnt_secondary_accwrites++; 1574 MNT_IUNLOCK(mp); 1575 return (0); 1576 } 1577 if (flags & V_NOWAIT) { 1578 MNT_REL(mp); 1579 MNT_IUNLOCK(mp); 1580 return (EWOULDBLOCK); 1581 } 1582 /* 1583 * Wait for the suspension to finish. 1584 */ 1585 error = msleep(&mp->mnt_flag, MNT_MTX(mp), 1586 (PUSER - 1) | (flags & PCATCH) | PDROP, "suspfs", 0); 1587 vfs_rel(mp); 1588 if (error == 0) 1589 goto retry; 1590 return (error); 1591 } 1592 1593 /* 1594 * Filesystem write operation has completed. If we are suspending and this 1595 * operation is the last one, notify the suspender that the suspension is 1596 * now in effect. 1597 */ 1598 void 1599 vn_finished_write(mp) 1600 struct mount *mp; 1601 { 1602 if (mp == NULL) 1603 return; 1604 MNT_ILOCK(mp); 1605 MNT_REL(mp); 1606 mp->mnt_writeopcount--; 1607 if (mp->mnt_writeopcount < 0) 1608 panic("vn_finished_write: neg cnt"); 1609 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && 1610 mp->mnt_writeopcount <= 0) 1611 wakeup(&mp->mnt_writeopcount); 1612 MNT_IUNLOCK(mp); 1613 } 1614 1615 1616 /* 1617 * Filesystem secondary write operation has completed. If we are 1618 * suspending and this operation is the last one, notify the suspender 1619 * that the suspension is now in effect. 1620 */ 1621 void 1622 vn_finished_secondary_write(mp) 1623 struct mount *mp; 1624 { 1625 if (mp == NULL) 1626 return; 1627 MNT_ILOCK(mp); 1628 MNT_REL(mp); 1629 mp->mnt_secondary_writes--; 1630 if (mp->mnt_secondary_writes < 0) 1631 panic("vn_finished_secondary_write: neg cnt"); 1632 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && 1633 mp->mnt_secondary_writes <= 0) 1634 wakeup(&mp->mnt_secondary_writes); 1635 MNT_IUNLOCK(mp); 1636 } 1637 1638 1639 1640 /* 1641 * Request a filesystem to suspend write operations. 1642 */ 1643 int 1644 vfs_write_suspend(mp) 1645 struct mount *mp; 1646 { 1647 int error; 1648 1649 MNT_ILOCK(mp); 1650 if (mp->mnt_susp_owner == curthread) { 1651 MNT_IUNLOCK(mp); 1652 return (EALREADY); 1653 } 1654 while (mp->mnt_kern_flag & MNTK_SUSPEND) 1655 msleep(&mp->mnt_flag, MNT_MTX(mp), PUSER - 1, "wsuspfs", 0); 1656 mp->mnt_kern_flag |= MNTK_SUSPEND; 1657 mp->mnt_susp_owner = curthread; 1658 if (mp->mnt_writeopcount > 0) 1659 (void) msleep(&mp->mnt_writeopcount, 1660 MNT_MTX(mp), (PUSER - 1)|PDROP, "suspwt", 0); 1661 else 1662 MNT_IUNLOCK(mp); 1663 if ((error = VFS_SYNC(mp, MNT_SUSPEND)) != 0) 1664 vfs_write_resume(mp); 1665 return (error); 1666 } 1667 1668 /* 1669 * Request a filesystem to resume write operations. 1670 */ 1671 void 1672 vfs_write_resume_flags(struct mount *mp, int flags) 1673 { 1674 1675 MNT_ILOCK(mp); 1676 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { 1677 KASSERT(mp->mnt_susp_owner == curthread, ("mnt_susp_owner")); 1678 mp->mnt_kern_flag &= ~(MNTK_SUSPEND | MNTK_SUSPEND2 | 1679 MNTK_SUSPENDED); 1680 mp->mnt_susp_owner = NULL; 1681 wakeup(&mp->mnt_writeopcount); 1682 wakeup(&mp->mnt_flag); 1683 curthread->td_pflags &= ~TDP_IGNSUSP; 1684 if ((flags & VR_START_WRITE) != 0) { 1685 MNT_REF(mp); 1686 mp->mnt_writeopcount++; 1687 } 1688 MNT_IUNLOCK(mp); 1689 if ((flags & VR_NO_SUSPCLR) == 0) 1690 VFS_SUSP_CLEAN(mp); 1691 } else if ((flags & VR_START_WRITE) != 0) { 1692 MNT_REF(mp); 1693 vn_start_write_locked(mp, 0); 1694 } else { 1695 MNT_IUNLOCK(mp); 1696 } 1697 } 1698 1699 void 1700 vfs_write_resume(struct mount *mp) 1701 { 1702 1703 vfs_write_resume_flags(mp, 0); 1704 } 1705 1706 /* 1707 * Implement kqueues for files by translating it to vnode operation. 1708 */ 1709 static int 1710 vn_kqfilter(struct file *fp, struct knote *kn) 1711 { 1712 int vfslocked; 1713 int error; 1714 1715 vfslocked = VFS_LOCK_GIANT(fp->f_vnode->v_mount); 1716 error = VOP_KQFILTER(fp->f_vnode, kn); 1717 VFS_UNLOCK_GIANT(vfslocked); 1718 1719 return error; 1720 } 1721 1722 /* 1723 * Simplified in-kernel wrapper calls for extended attribute access. 1724 * Both calls pass in a NULL credential, authorizing as "kernel" access. 1725 * Set IO_NODELOCKED in ioflg if the vnode is already locked. 1726 */ 1727 int 1728 vn_extattr_get(struct vnode *vp, int ioflg, int attrnamespace, 1729 const char *attrname, int *buflen, char *buf, struct thread *td) 1730 { 1731 struct uio auio; 1732 struct iovec iov; 1733 int error; 1734 1735 iov.iov_len = *buflen; 1736 iov.iov_base = buf; 1737 1738 auio.uio_iov = &iov; 1739 auio.uio_iovcnt = 1; 1740 auio.uio_rw = UIO_READ; 1741 auio.uio_segflg = UIO_SYSSPACE; 1742 auio.uio_td = td; 1743 auio.uio_offset = 0; 1744 auio.uio_resid = *buflen; 1745 1746 if ((ioflg & IO_NODELOCKED) == 0) 1747 vn_lock(vp, LK_SHARED | LK_RETRY); 1748 1749 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 1750 1751 /* authorize attribute retrieval as kernel */ 1752 error = VOP_GETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, NULL, 1753 td); 1754 1755 if ((ioflg & IO_NODELOCKED) == 0) 1756 VOP_UNLOCK(vp, 0); 1757 1758 if (error == 0) { 1759 *buflen = *buflen - auio.uio_resid; 1760 } 1761 1762 return (error); 1763 } 1764 1765 /* 1766 * XXX failure mode if partially written? 1767 */ 1768 int 1769 vn_extattr_set(struct vnode *vp, int ioflg, int attrnamespace, 1770 const char *attrname, int buflen, char *buf, struct thread *td) 1771 { 1772 struct uio auio; 1773 struct iovec iov; 1774 struct mount *mp; 1775 int error; 1776 1777 iov.iov_len = buflen; 1778 iov.iov_base = buf; 1779 1780 auio.uio_iov = &iov; 1781 auio.uio_iovcnt = 1; 1782 auio.uio_rw = UIO_WRITE; 1783 auio.uio_segflg = UIO_SYSSPACE; 1784 auio.uio_td = td; 1785 auio.uio_offset = 0; 1786 auio.uio_resid = buflen; 1787 1788 if ((ioflg & IO_NODELOCKED) == 0) { 1789 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) 1790 return (error); 1791 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1792 } 1793 1794 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 1795 1796 /* authorize attribute setting as kernel */ 1797 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, td); 1798 1799 if ((ioflg & IO_NODELOCKED) == 0) { 1800 vn_finished_write(mp); 1801 VOP_UNLOCK(vp, 0); 1802 } 1803 1804 return (error); 1805 } 1806 1807 int 1808 vn_extattr_rm(struct vnode *vp, int ioflg, int attrnamespace, 1809 const char *attrname, struct thread *td) 1810 { 1811 struct mount *mp; 1812 int error; 1813 1814 if ((ioflg & IO_NODELOCKED) == 0) { 1815 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) 1816 return (error); 1817 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1818 } 1819 1820 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 1821 1822 /* authorize attribute removal as kernel */ 1823 error = VOP_DELETEEXTATTR(vp, attrnamespace, attrname, NULL, td); 1824 if (error == EOPNOTSUPP) 1825 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, NULL, 1826 NULL, td); 1827 1828 if ((ioflg & IO_NODELOCKED) == 0) { 1829 vn_finished_write(mp); 1830 VOP_UNLOCK(vp, 0); 1831 } 1832 1833 return (error); 1834 } 1835 1836 int 1837 vn_vget_ino(struct vnode *vp, ino_t ino, int lkflags, struct vnode **rvp) 1838 { 1839 struct mount *mp; 1840 int ltype, error; 1841 1842 mp = vp->v_mount; 1843 ltype = VOP_ISLOCKED(vp); 1844 KASSERT(ltype == LK_EXCLUSIVE || ltype == LK_SHARED, 1845 ("vn_vget_ino: vp not locked")); 1846 error = vfs_busy(mp, MBF_NOWAIT); 1847 if (error != 0) { 1848 vfs_ref(mp); 1849 VOP_UNLOCK(vp, 0); 1850 error = vfs_busy(mp, 0); 1851 vn_lock(vp, ltype | LK_RETRY); 1852 vfs_rel(mp); 1853 if (error != 0) 1854 return (ENOENT); 1855 if (vp->v_iflag & VI_DOOMED) { 1856 vfs_unbusy(mp); 1857 return (ENOENT); 1858 } 1859 } 1860 VOP_UNLOCK(vp, 0); 1861 error = VFS_VGET(mp, ino, lkflags, rvp); 1862 vfs_unbusy(mp); 1863 vn_lock(vp, ltype | LK_RETRY); 1864 if (vp->v_iflag & VI_DOOMED) { 1865 if (error == 0) 1866 vput(*rvp); 1867 error = ENOENT; 1868 } 1869 return (error); 1870 } 1871 1872 int 1873 vn_rlimit_fsize(const struct vnode *vp, const struct uio *uio, 1874 const struct thread *td) 1875 { 1876 1877 if (vp->v_type != VREG || td == NULL) 1878 return (0); 1879 PROC_LOCK(td->td_proc); 1880 if ((uoff_t)uio->uio_offset + uio->uio_resid > 1881 lim_cur(td->td_proc, RLIMIT_FSIZE)) { 1882 kern_psignal(td->td_proc, SIGXFSZ); 1883 PROC_UNLOCK(td->td_proc); 1884 return (EFBIG); 1885 } 1886 PROC_UNLOCK(td->td_proc); 1887 return (0); 1888 } 1889 1890 int 1891 vn_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 1892 struct thread *td) 1893 { 1894 struct vnode *vp; 1895 int error, vfslocked; 1896 1897 vp = fp->f_vnode; 1898 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 1899 #ifdef AUDIT 1900 vn_lock(vp, LK_SHARED | LK_RETRY); 1901 AUDIT_ARG_VNODE1(vp); 1902 VOP_UNLOCK(vp, 0); 1903 #endif 1904 error = setfmode(td, active_cred, vp, mode); 1905 VFS_UNLOCK_GIANT(vfslocked); 1906 return (error); 1907 } 1908 1909 int 1910 vn_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 1911 struct thread *td) 1912 { 1913 struct vnode *vp; 1914 int error, vfslocked; 1915 1916 vp = fp->f_vnode; 1917 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 1918 #ifdef AUDIT 1919 vn_lock(vp, LK_SHARED | LK_RETRY); 1920 AUDIT_ARG_VNODE1(vp); 1921 VOP_UNLOCK(vp, 0); 1922 #endif 1923 error = setfown(td, active_cred, vp, uid, gid); 1924 VFS_UNLOCK_GIANT(vfslocked); 1925 return (error); 1926 } 1927 1928 void 1929 vn_pages_remove(struct vnode *vp, vm_pindex_t start, vm_pindex_t end) 1930 { 1931 vm_object_t object; 1932 1933 if ((object = vp->v_object) == NULL) 1934 return; 1935 VM_OBJECT_LOCK(object); 1936 vm_object_page_remove(object, start, end, 0); 1937 VM_OBJECT_UNLOCK(object); 1938 } 1939 1940 int 1941 vn_bmap_seekhole(struct vnode *vp, u_long cmd, off_t *off, struct ucred *cred) 1942 { 1943 struct vattr va; 1944 daddr_t bn, bnp; 1945 uint64_t bsize; 1946 off_t noff; 1947 int error; 1948 1949 KASSERT(cmd == FIOSEEKHOLE || cmd == FIOSEEKDATA, 1950 ("Wrong command %lu", cmd)); 1951 1952 if (vn_lock(vp, LK_SHARED) != 0) 1953 return (EBADF); 1954 if (vp->v_type != VREG) { 1955 error = ENOTTY; 1956 goto unlock; 1957 } 1958 error = VOP_GETATTR(vp, &va, cred); 1959 if (error != 0) 1960 goto unlock; 1961 noff = *off; 1962 if (noff >= va.va_size) { 1963 error = ENXIO; 1964 goto unlock; 1965 } 1966 bsize = vp->v_mount->mnt_stat.f_iosize; 1967 for (bn = noff / bsize; noff < va.va_size; bn++, noff += bsize) { 1968 error = VOP_BMAP(vp, bn, NULL, &bnp, NULL, NULL); 1969 if (error == EOPNOTSUPP) { 1970 error = ENOTTY; 1971 goto unlock; 1972 } 1973 if ((bnp == -1 && cmd == FIOSEEKHOLE) || 1974 (bnp != -1 && cmd == FIOSEEKDATA)) { 1975 noff = bn * bsize; 1976 if (noff < *off) 1977 noff = *off; 1978 goto unlock; 1979 } 1980 } 1981 if (noff > va.va_size) 1982 noff = va.va_size; 1983 /* noff == va.va_size. There is an implicit hole at the end of file. */ 1984 if (cmd == FIOSEEKDATA) 1985 error = ENXIO; 1986 unlock: 1987 VOP_UNLOCK(vp, 0); 1988 if (error == 0) 1989 *off = noff; 1990 return (error); 1991 }
Cache object: 2c8b0215d8c0f5adcd45df03c4e2bcc2
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