1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Copyright (c) 2012 Konstantin Belousov <kib@FreeBSD.org> 13 * Copyright (c) 2013, 2014 The FreeBSD Foundation 14 * 15 * Portions of this software were developed by Konstantin Belousov 16 * under sponsorship from the FreeBSD Foundation. 17 * 18 * Redistribution and use in source and binary forms, with or without 19 * modification, are permitted provided that the following conditions 20 * are met: 21 * 1. Redistributions of source code must retain the above copyright 22 * notice, this list of conditions and the following disclaimer. 23 * 2. Redistributions in binary form must reproduce the above copyright 24 * notice, this list of conditions and the following disclaimer in the 25 * documentation and/or other materials provided with the distribution. 26 * 3. Neither the name of the University nor the names of its contributors 27 * may be used to endorse or promote products derived from this software 28 * without specific prior written permission. 29 * 30 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 31 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 32 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 33 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 34 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 35 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 36 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 37 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 38 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 39 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 40 * SUCH DAMAGE. 41 * 42 * @(#)vfs_vnops.c 8.2 (Berkeley) 1/21/94 43 */ 44 45 #include <sys/cdefs.h> 46 __FBSDID("$FreeBSD$"); 47 48 #include "opt_hwpmc_hooks.h" 49 50 #include <sys/param.h> 51 #include <sys/systm.h> 52 #include <sys/disk.h> 53 #include <sys/fail.h> 54 #include <sys/fcntl.h> 55 #include <sys/file.h> 56 #include <sys/kdb.h> 57 #include <sys/ktr.h> 58 #include <sys/stat.h> 59 #include <sys/priv.h> 60 #include <sys/proc.h> 61 #include <sys/limits.h> 62 #include <sys/lock.h> 63 #include <sys/mman.h> 64 #include <sys/mount.h> 65 #include <sys/mutex.h> 66 #include <sys/namei.h> 67 #include <sys/vnode.h> 68 #include <sys/bio.h> 69 #include <sys/buf.h> 70 #include <sys/filio.h> 71 #include <sys/resourcevar.h> 72 #include <sys/rwlock.h> 73 #include <sys/prng.h> 74 #include <sys/sx.h> 75 #include <sys/sleepqueue.h> 76 #include <sys/sysctl.h> 77 #include <sys/ttycom.h> 78 #include <sys/conf.h> 79 #include <sys/syslog.h> 80 #include <sys/unistd.h> 81 #include <sys/user.h> 82 #include <sys/ktrace.h> 83 84 #include <security/audit/audit.h> 85 #include <security/mac/mac_framework.h> 86 87 #include <vm/vm.h> 88 #include <vm/vm_extern.h> 89 #include <vm/pmap.h> 90 #include <vm/vm_map.h> 91 #include <vm/vm_object.h> 92 #include <vm/vm_page.h> 93 #include <vm/vm_pager.h> 94 95 #ifdef HWPMC_HOOKS 96 #include <sys/pmckern.h> 97 #endif 98 99 static fo_rdwr_t vn_read; 100 static fo_rdwr_t vn_write; 101 static fo_rdwr_t vn_io_fault; 102 static fo_truncate_t vn_truncate; 103 static fo_ioctl_t vn_ioctl; 104 static fo_poll_t vn_poll; 105 static fo_kqfilter_t vn_kqfilter; 106 static fo_close_t vn_closefile; 107 static fo_mmap_t vn_mmap; 108 static fo_fallocate_t vn_fallocate; 109 static fo_fspacectl_t vn_fspacectl; 110 111 struct fileops vnops = { 112 .fo_read = vn_io_fault, 113 .fo_write = vn_io_fault, 114 .fo_truncate = vn_truncate, 115 .fo_ioctl = vn_ioctl, 116 .fo_poll = vn_poll, 117 .fo_kqfilter = vn_kqfilter, 118 .fo_stat = vn_statfile, 119 .fo_close = vn_closefile, 120 .fo_chmod = vn_chmod, 121 .fo_chown = vn_chown, 122 .fo_sendfile = vn_sendfile, 123 .fo_seek = vn_seek, 124 .fo_fill_kinfo = vn_fill_kinfo, 125 .fo_mmap = vn_mmap, 126 .fo_fallocate = vn_fallocate, 127 .fo_fspacectl = vn_fspacectl, 128 .fo_flags = DFLAG_PASSABLE | DFLAG_SEEKABLE 129 }; 130 131 const u_int io_hold_cnt = 16; 132 static int vn_io_fault_enable = 1; 133 SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_enable, CTLFLAG_RWTUN, 134 &vn_io_fault_enable, 0, "Enable vn_io_fault lock avoidance"); 135 static int vn_io_fault_prefault = 0; 136 SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_prefault, CTLFLAG_RWTUN, 137 &vn_io_fault_prefault, 0, "Enable vn_io_fault prefaulting"); 138 static int vn_io_pgcache_read_enable = 1; 139 SYSCTL_INT(_debug, OID_AUTO, vn_io_pgcache_read_enable, CTLFLAG_RWTUN, 140 &vn_io_pgcache_read_enable, 0, 141 "Enable copying from page cache for reads, avoiding fs"); 142 static u_long vn_io_faults_cnt; 143 SYSCTL_ULONG(_debug, OID_AUTO, vn_io_faults, CTLFLAG_RD, 144 &vn_io_faults_cnt, 0, "Count of vn_io_fault lock avoidance triggers"); 145 146 static int vfs_allow_read_dir = 0; 147 SYSCTL_INT(_security_bsd, OID_AUTO, allow_read_dir, CTLFLAG_RW, 148 &vfs_allow_read_dir, 0, 149 "Enable read(2) of directory by root for filesystems that support it"); 150 151 /* 152 * Returns true if vn_io_fault mode of handling the i/o request should 153 * be used. 154 */ 155 static bool 156 do_vn_io_fault(struct vnode *vp, struct uio *uio) 157 { 158 struct mount *mp; 159 160 return (uio->uio_segflg == UIO_USERSPACE && vp->v_type == VREG && 161 (mp = vp->v_mount) != NULL && 162 (mp->mnt_kern_flag & MNTK_NO_IOPF) != 0 && vn_io_fault_enable); 163 } 164 165 /* 166 * Structure used to pass arguments to vn_io_fault1(), to do either 167 * file- or vnode-based I/O calls. 168 */ 169 struct vn_io_fault_args { 170 enum { 171 VN_IO_FAULT_FOP, 172 VN_IO_FAULT_VOP 173 } kind; 174 struct ucred *cred; 175 int flags; 176 union { 177 struct fop_args_tag { 178 struct file *fp; 179 fo_rdwr_t *doio; 180 } fop_args; 181 struct vop_args_tag { 182 struct vnode *vp; 183 } vop_args; 184 } args; 185 }; 186 187 static int vn_io_fault1(struct vnode *vp, struct uio *uio, 188 struct vn_io_fault_args *args, struct thread *td); 189 190 int 191 vn_open(struct nameidata *ndp, int *flagp, int cmode, struct file *fp) 192 { 193 struct thread *td = curthread; 194 195 return (vn_open_cred(ndp, flagp, cmode, 0, td->td_ucred, fp)); 196 } 197 198 static uint64_t 199 open2nameif(int fmode, u_int vn_open_flags) 200 { 201 uint64_t res; 202 203 res = ISOPEN | LOCKLEAF; 204 if ((fmode & O_RESOLVE_BENEATH) != 0) 205 res |= RBENEATH; 206 if ((fmode & O_EMPTY_PATH) != 0) 207 res |= EMPTYPATH; 208 if ((fmode & FREAD) != 0) 209 res |= OPENREAD; 210 if ((fmode & FWRITE) != 0) 211 res |= OPENWRITE; 212 if ((vn_open_flags & VN_OPEN_NOAUDIT) == 0) 213 res |= AUDITVNODE1; 214 if ((vn_open_flags & VN_OPEN_NOCAPCHECK) != 0) 215 res |= NOCAPCHECK; 216 if ((vn_open_flags & VN_OPEN_WANTIOCTLCAPS) != 0) 217 res |= WANTIOCTLCAPS; 218 return (res); 219 } 220 221 /* 222 * Common code for vnode open operations via a name lookup. 223 * Lookup the vnode and invoke VOP_CREATE if needed. 224 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine. 225 * 226 * Note that this does NOT free nameidata for the successful case, 227 * due to the NDINIT being done elsewhere. 228 */ 229 int 230 vn_open_cred(struct nameidata *ndp, int *flagp, int cmode, u_int vn_open_flags, 231 struct ucred *cred, struct file *fp) 232 { 233 struct vnode *vp; 234 struct mount *mp; 235 struct vattr vat; 236 struct vattr *vap = &vat; 237 int fmode, error; 238 bool first_open; 239 240 restart: 241 first_open = false; 242 fmode = *flagp; 243 if ((fmode & (O_CREAT | O_EXCL | O_DIRECTORY)) == (O_CREAT | 244 O_EXCL | O_DIRECTORY) || 245 (fmode & (O_CREAT | O_EMPTY_PATH)) == (O_CREAT | O_EMPTY_PATH)) 246 return (EINVAL); 247 else if ((fmode & (O_CREAT | O_DIRECTORY)) == O_CREAT) { 248 ndp->ni_cnd.cn_nameiop = CREATE; 249 ndp->ni_cnd.cn_flags = open2nameif(fmode, vn_open_flags); 250 /* 251 * Set NOCACHE to avoid flushing the cache when 252 * rolling in many files at once. 253 * 254 * Set NC_KEEPPOSENTRY to keep positive entries if they already 255 * exist despite NOCACHE. 256 */ 257 ndp->ni_cnd.cn_flags |= LOCKPARENT | NOCACHE | NC_KEEPPOSENTRY; 258 if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0) 259 ndp->ni_cnd.cn_flags |= FOLLOW; 260 if ((vn_open_flags & VN_OPEN_INVFS) == 0) 261 bwillwrite(); 262 if ((error = namei(ndp)) != 0) 263 return (error); 264 if (ndp->ni_vp == NULL) { 265 VATTR_NULL(vap); 266 vap->va_type = VREG; 267 vap->va_mode = cmode; 268 if (fmode & O_EXCL) 269 vap->va_vaflags |= VA_EXCLUSIVE; 270 if (vn_start_write(ndp->ni_dvp, &mp, V_NOWAIT) != 0) { 271 NDFREE_PNBUF(ndp); 272 vput(ndp->ni_dvp); 273 if ((error = vn_start_write(NULL, &mp, 274 V_XSLEEP | V_PCATCH)) != 0) 275 return (error); 276 NDREINIT(ndp); 277 goto restart; 278 } 279 if ((vn_open_flags & VN_OPEN_NAMECACHE) != 0) 280 ndp->ni_cnd.cn_flags |= MAKEENTRY; 281 #ifdef MAC 282 error = mac_vnode_check_create(cred, ndp->ni_dvp, 283 &ndp->ni_cnd, vap); 284 if (error == 0) 285 #endif 286 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp, 287 &ndp->ni_cnd, vap); 288 vp = ndp->ni_vp; 289 if (error == 0 && (fmode & O_EXCL) != 0 && 290 (fmode & (O_EXLOCK | O_SHLOCK)) != 0) { 291 VI_LOCK(vp); 292 vp->v_iflag |= VI_FOPENING; 293 VI_UNLOCK(vp); 294 first_open = true; 295 } 296 VOP_VPUT_PAIR(ndp->ni_dvp, error == 0 ? &vp : NULL, 297 false); 298 vn_finished_write(mp); 299 if (error) { 300 NDFREE_PNBUF(ndp); 301 if (error == ERELOOKUP) { 302 NDREINIT(ndp); 303 goto restart; 304 } 305 return (error); 306 } 307 fmode &= ~O_TRUNC; 308 } else { 309 if (ndp->ni_dvp == ndp->ni_vp) 310 vrele(ndp->ni_dvp); 311 else 312 vput(ndp->ni_dvp); 313 ndp->ni_dvp = NULL; 314 vp = ndp->ni_vp; 315 if (fmode & O_EXCL) { 316 error = EEXIST; 317 goto bad; 318 } 319 if (vp->v_type == VDIR) { 320 error = EISDIR; 321 goto bad; 322 } 323 fmode &= ~O_CREAT; 324 } 325 } else { 326 ndp->ni_cnd.cn_nameiop = LOOKUP; 327 ndp->ni_cnd.cn_flags = open2nameif(fmode, vn_open_flags); 328 ndp->ni_cnd.cn_flags |= (fmode & O_NOFOLLOW) != 0 ? NOFOLLOW : 329 FOLLOW; 330 if ((fmode & FWRITE) == 0) 331 ndp->ni_cnd.cn_flags |= LOCKSHARED; 332 if ((error = namei(ndp)) != 0) 333 return (error); 334 vp = ndp->ni_vp; 335 } 336 error = vn_open_vnode(vp, fmode, cred, curthread, fp); 337 if (first_open) { 338 VI_LOCK(vp); 339 vp->v_iflag &= ~VI_FOPENING; 340 wakeup(vp); 341 VI_UNLOCK(vp); 342 } 343 if (error) 344 goto bad; 345 *flagp = fmode; 346 return (0); 347 bad: 348 NDFREE_PNBUF(ndp); 349 vput(vp); 350 *flagp = fmode; 351 ndp->ni_vp = NULL; 352 return (error); 353 } 354 355 static int 356 vn_open_vnode_advlock(struct vnode *vp, int fmode, struct file *fp) 357 { 358 struct flock lf; 359 int error, lock_flags, type; 360 361 ASSERT_VOP_LOCKED(vp, "vn_open_vnode_advlock"); 362 if ((fmode & (O_EXLOCK | O_SHLOCK)) == 0) 363 return (0); 364 KASSERT(fp != NULL, ("open with flock requires fp")); 365 if (fp->f_type != DTYPE_NONE && fp->f_type != DTYPE_VNODE) 366 return (EOPNOTSUPP); 367 368 lock_flags = VOP_ISLOCKED(vp); 369 VOP_UNLOCK(vp); 370 371 lf.l_whence = SEEK_SET; 372 lf.l_start = 0; 373 lf.l_len = 0; 374 lf.l_type = (fmode & O_EXLOCK) != 0 ? F_WRLCK : F_RDLCK; 375 type = F_FLOCK; 376 if ((fmode & FNONBLOCK) == 0) 377 type |= F_WAIT; 378 if ((fmode & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL)) 379 type |= F_FIRSTOPEN; 380 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, type); 381 if (error == 0) 382 fp->f_flag |= FHASLOCK; 383 384 vn_lock(vp, lock_flags | LK_RETRY); 385 return (error); 386 } 387 388 /* 389 * Common code for vnode open operations once a vnode is located. 390 * Check permissions, and call the VOP_OPEN routine. 391 */ 392 int 393 vn_open_vnode(struct vnode *vp, int fmode, struct ucred *cred, 394 struct thread *td, struct file *fp) 395 { 396 accmode_t accmode; 397 int error; 398 399 if (vp->v_type == VLNK) { 400 if ((fmode & O_PATH) == 0 || (fmode & FEXEC) != 0) 401 return (EMLINK); 402 } 403 if (vp->v_type != VDIR && fmode & O_DIRECTORY) 404 return (ENOTDIR); 405 406 accmode = 0; 407 if ((fmode & O_PATH) == 0) { 408 if (vp->v_type == VSOCK) 409 return (EOPNOTSUPP); 410 if ((fmode & (FWRITE | O_TRUNC)) != 0) { 411 if (vp->v_type == VDIR) 412 return (EISDIR); 413 accmode |= VWRITE; 414 } 415 if ((fmode & FREAD) != 0) 416 accmode |= VREAD; 417 if ((fmode & O_APPEND) && (fmode & FWRITE)) 418 accmode |= VAPPEND; 419 #ifdef MAC 420 if ((fmode & O_CREAT) != 0) 421 accmode |= VCREAT; 422 #endif 423 } 424 if ((fmode & FEXEC) != 0) 425 accmode |= VEXEC; 426 #ifdef MAC 427 if ((fmode & O_VERIFY) != 0) 428 accmode |= VVERIFY; 429 error = mac_vnode_check_open(cred, vp, accmode); 430 if (error != 0) 431 return (error); 432 433 accmode &= ~(VCREAT | VVERIFY); 434 #endif 435 if ((fmode & O_CREAT) == 0 && accmode != 0) { 436 error = VOP_ACCESS(vp, accmode, cred, td); 437 if (error != 0) 438 return (error); 439 } 440 if ((fmode & O_PATH) != 0) { 441 if (vp->v_type != VFIFO && vp->v_type != VSOCK && 442 VOP_ACCESS(vp, VREAD, cred, td) == 0) 443 fp->f_flag |= FKQALLOWED; 444 return (0); 445 } 446 447 if (vp->v_type == VFIFO && VOP_ISLOCKED(vp) != LK_EXCLUSIVE) 448 vn_lock(vp, LK_UPGRADE | LK_RETRY); 449 error = VOP_OPEN(vp, fmode, cred, td, fp); 450 if (error != 0) 451 return (error); 452 453 error = vn_open_vnode_advlock(vp, fmode, fp); 454 if (error == 0 && (fmode & FWRITE) != 0) { 455 error = VOP_ADD_WRITECOUNT(vp, 1); 456 if (error == 0) { 457 CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d", 458 __func__, vp, vp->v_writecount); 459 } 460 } 461 462 /* 463 * Error from advlock or VOP_ADD_WRITECOUNT() still requires 464 * calling VOP_CLOSE() to pair with earlier VOP_OPEN(). 465 */ 466 if (error != 0) { 467 if (fp != NULL) { 468 /* 469 * Arrange the call by having fdrop() to use 470 * vn_closefile(). This is to satisfy 471 * filesystems like devfs or tmpfs, which 472 * override fo_close(). 473 */ 474 fp->f_flag |= FOPENFAILED; 475 fp->f_vnode = vp; 476 if (fp->f_ops == &badfileops) { 477 fp->f_type = DTYPE_VNODE; 478 fp->f_ops = &vnops; 479 } 480 vref(vp); 481 } else { 482 /* 483 * If there is no fp, due to kernel-mode open, 484 * we can call VOP_CLOSE() now. 485 */ 486 if (vp->v_type != VFIFO && (fmode & FWRITE) != 0 && 487 !MNT_EXTENDED_SHARED(vp->v_mount) && 488 VOP_ISLOCKED(vp) != LK_EXCLUSIVE) 489 vn_lock(vp, LK_UPGRADE | LK_RETRY); 490 (void)VOP_CLOSE(vp, fmode & (FREAD | FWRITE | FEXEC), 491 cred, td); 492 } 493 } 494 495 ASSERT_VOP_LOCKED(vp, "vn_open_vnode"); 496 return (error); 497 498 } 499 500 /* 501 * Check for write permissions on the specified vnode. 502 * Prototype text segments cannot be written. 503 * It is racy. 504 */ 505 int 506 vn_writechk(struct vnode *vp) 507 { 508 509 ASSERT_VOP_LOCKED(vp, "vn_writechk"); 510 /* 511 * If there's shared text associated with 512 * the vnode, try to free it up once. If 513 * we fail, we can't allow writing. 514 */ 515 if (VOP_IS_TEXT(vp)) 516 return (ETXTBSY); 517 518 return (0); 519 } 520 521 /* 522 * Vnode close call 523 */ 524 static int 525 vn_close1(struct vnode *vp, int flags, struct ucred *file_cred, 526 struct thread *td, bool keep_ref) 527 { 528 struct mount *mp; 529 int error, lock_flags; 530 531 if (vp->v_type != VFIFO && (flags & FWRITE) == 0 && 532 MNT_EXTENDED_SHARED(vp->v_mount)) 533 lock_flags = LK_SHARED; 534 else 535 lock_flags = LK_EXCLUSIVE; 536 537 vn_start_write(vp, &mp, V_WAIT); 538 vn_lock(vp, lock_flags | LK_RETRY); 539 AUDIT_ARG_VNODE1(vp); 540 if ((flags & (FWRITE | FOPENFAILED)) == FWRITE) { 541 VOP_ADD_WRITECOUNT_CHECKED(vp, -1); 542 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d", 543 __func__, vp, vp->v_writecount); 544 } 545 error = VOP_CLOSE(vp, flags, file_cred, td); 546 if (keep_ref) 547 VOP_UNLOCK(vp); 548 else 549 vput(vp); 550 vn_finished_write(mp); 551 return (error); 552 } 553 554 int 555 vn_close(struct vnode *vp, int flags, struct ucred *file_cred, 556 struct thread *td) 557 { 558 559 return (vn_close1(vp, flags, file_cred, td, false)); 560 } 561 562 /* 563 * Heuristic to detect sequential operation. 564 */ 565 static int 566 sequential_heuristic(struct uio *uio, struct file *fp) 567 { 568 enum uio_rw rw; 569 570 ASSERT_VOP_LOCKED(fp->f_vnode, __func__); 571 572 rw = uio->uio_rw; 573 if (fp->f_flag & FRDAHEAD) 574 return (fp->f_seqcount[rw] << IO_SEQSHIFT); 575 576 /* 577 * Offset 0 is handled specially. open() sets f_seqcount to 1 so 578 * that the first I/O is normally considered to be slightly 579 * sequential. Seeking to offset 0 doesn't change sequentiality 580 * unless previous seeks have reduced f_seqcount to 0, in which 581 * case offset 0 is not special. 582 */ 583 if ((uio->uio_offset == 0 && fp->f_seqcount[rw] > 0) || 584 uio->uio_offset == fp->f_nextoff[rw]) { 585 /* 586 * f_seqcount is in units of fixed-size blocks so that it 587 * depends mainly on the amount of sequential I/O and not 588 * much on the number of sequential I/O's. The fixed size 589 * of 16384 is hard-coded here since it is (not quite) just 590 * a magic size that works well here. This size is more 591 * closely related to the best I/O size for real disks than 592 * to any block size used by software. 593 */ 594 if (uio->uio_resid >= IO_SEQMAX * 16384) 595 fp->f_seqcount[rw] = IO_SEQMAX; 596 else { 597 fp->f_seqcount[rw] += howmany(uio->uio_resid, 16384); 598 if (fp->f_seqcount[rw] > IO_SEQMAX) 599 fp->f_seqcount[rw] = IO_SEQMAX; 600 } 601 return (fp->f_seqcount[rw] << IO_SEQSHIFT); 602 } 603 604 /* Not sequential. Quickly draw-down sequentiality. */ 605 if (fp->f_seqcount[rw] > 1) 606 fp->f_seqcount[rw] = 1; 607 else 608 fp->f_seqcount[rw] = 0; 609 return (0); 610 } 611 612 /* 613 * Package up an I/O request on a vnode into a uio and do it. 614 */ 615 int 616 vn_rdwr(enum uio_rw rw, struct vnode *vp, void *base, int len, off_t offset, 617 enum uio_seg segflg, int ioflg, struct ucred *active_cred, 618 struct ucred *file_cred, ssize_t *aresid, struct thread *td) 619 { 620 struct uio auio; 621 struct iovec aiov; 622 struct mount *mp; 623 struct ucred *cred; 624 void *rl_cookie; 625 struct vn_io_fault_args args; 626 int error, lock_flags; 627 628 if (offset < 0 && vp->v_type != VCHR) 629 return (EINVAL); 630 auio.uio_iov = &aiov; 631 auio.uio_iovcnt = 1; 632 aiov.iov_base = base; 633 aiov.iov_len = len; 634 auio.uio_resid = len; 635 auio.uio_offset = offset; 636 auio.uio_segflg = segflg; 637 auio.uio_rw = rw; 638 auio.uio_td = td; 639 error = 0; 640 641 if ((ioflg & IO_NODELOCKED) == 0) { 642 if ((ioflg & IO_RANGELOCKED) == 0) { 643 if (rw == UIO_READ) { 644 rl_cookie = vn_rangelock_rlock(vp, offset, 645 offset + len); 646 } else if ((ioflg & IO_APPEND) != 0) { 647 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 648 } else { 649 rl_cookie = vn_rangelock_wlock(vp, offset, 650 offset + len); 651 } 652 } else 653 rl_cookie = NULL; 654 mp = NULL; 655 if (rw == UIO_WRITE) { 656 if (vp->v_type != VCHR && 657 (error = vn_start_write(vp, &mp, V_WAIT | V_PCATCH)) 658 != 0) 659 goto out; 660 lock_flags = vn_lktype_write(mp, vp); 661 } else 662 lock_flags = LK_SHARED; 663 vn_lock(vp, lock_flags | LK_RETRY); 664 } else 665 rl_cookie = NULL; 666 667 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 668 #ifdef MAC 669 if ((ioflg & IO_NOMACCHECK) == 0) { 670 if (rw == UIO_READ) 671 error = mac_vnode_check_read(active_cred, file_cred, 672 vp); 673 else 674 error = mac_vnode_check_write(active_cred, file_cred, 675 vp); 676 } 677 #endif 678 if (error == 0) { 679 if (file_cred != NULL) 680 cred = file_cred; 681 else 682 cred = active_cred; 683 if (do_vn_io_fault(vp, &auio)) { 684 args.kind = VN_IO_FAULT_VOP; 685 args.cred = cred; 686 args.flags = ioflg; 687 args.args.vop_args.vp = vp; 688 error = vn_io_fault1(vp, &auio, &args, td); 689 } else if (rw == UIO_READ) { 690 error = VOP_READ(vp, &auio, ioflg, cred); 691 } else /* if (rw == UIO_WRITE) */ { 692 error = VOP_WRITE(vp, &auio, ioflg, cred); 693 } 694 } 695 if (aresid) 696 *aresid = auio.uio_resid; 697 else 698 if (auio.uio_resid && error == 0) 699 error = EIO; 700 if ((ioflg & IO_NODELOCKED) == 0) { 701 VOP_UNLOCK(vp); 702 if (mp != NULL) 703 vn_finished_write(mp); 704 } 705 out: 706 if (rl_cookie != NULL) 707 vn_rangelock_unlock(vp, rl_cookie); 708 return (error); 709 } 710 711 /* 712 * Package up an I/O request on a vnode into a uio and do it. The I/O 713 * request is split up into smaller chunks and we try to avoid saturating 714 * the buffer cache while potentially holding a vnode locked, so we 715 * check bwillwrite() before calling vn_rdwr(). We also call kern_yield() 716 * to give other processes a chance to lock the vnode (either other processes 717 * core'ing the same binary, or unrelated processes scanning the directory). 718 */ 719 int 720 vn_rdwr_inchunks(enum uio_rw rw, struct vnode *vp, void *base, size_t len, 721 off_t offset, enum uio_seg segflg, int ioflg, struct ucred *active_cred, 722 struct ucred *file_cred, size_t *aresid, struct thread *td) 723 { 724 int error = 0; 725 ssize_t iaresid; 726 727 do { 728 int chunk; 729 730 /* 731 * Force `offset' to a multiple of MAXBSIZE except possibly 732 * for the first chunk, so that filesystems only need to 733 * write full blocks except possibly for the first and last 734 * chunks. 735 */ 736 chunk = MAXBSIZE - (uoff_t)offset % MAXBSIZE; 737 738 if (chunk > len) 739 chunk = len; 740 if (rw != UIO_READ && vp->v_type == VREG) 741 bwillwrite(); 742 iaresid = 0; 743 error = vn_rdwr(rw, vp, base, chunk, offset, segflg, 744 ioflg, active_cred, file_cred, &iaresid, td); 745 len -= chunk; /* aresid calc already includes length */ 746 if (error) 747 break; 748 offset += chunk; 749 base = (char *)base + chunk; 750 kern_yield(PRI_USER); 751 } while (len); 752 if (aresid) 753 *aresid = len + iaresid; 754 return (error); 755 } 756 757 #if OFF_MAX <= LONG_MAX 758 off_t 759 foffset_lock(struct file *fp, int flags) 760 { 761 volatile short *flagsp; 762 off_t res; 763 short state; 764 765 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed")); 766 767 if ((flags & FOF_NOLOCK) != 0) 768 return (atomic_load_long(&fp->f_offset)); 769 770 /* 771 * According to McKusick the vn lock was protecting f_offset here. 772 * It is now protected by the FOFFSET_LOCKED flag. 773 */ 774 flagsp = &fp->f_vnread_flags; 775 if (atomic_cmpset_acq_16(flagsp, 0, FOFFSET_LOCKED)) 776 return (atomic_load_long(&fp->f_offset)); 777 778 sleepq_lock(&fp->f_vnread_flags); 779 state = atomic_load_16(flagsp); 780 for (;;) { 781 if ((state & FOFFSET_LOCKED) == 0) { 782 if (!atomic_fcmpset_acq_16(flagsp, &state, 783 FOFFSET_LOCKED)) 784 continue; 785 break; 786 } 787 if ((state & FOFFSET_LOCK_WAITING) == 0) { 788 if (!atomic_fcmpset_acq_16(flagsp, &state, 789 state | FOFFSET_LOCK_WAITING)) 790 continue; 791 } 792 DROP_GIANT(); 793 sleepq_add(&fp->f_vnread_flags, NULL, "vofflock", 0, 0); 794 sleepq_wait(&fp->f_vnread_flags, PUSER -1); 795 PICKUP_GIANT(); 796 sleepq_lock(&fp->f_vnread_flags); 797 state = atomic_load_16(flagsp); 798 } 799 res = atomic_load_long(&fp->f_offset); 800 sleepq_release(&fp->f_vnread_flags); 801 return (res); 802 } 803 804 void 805 foffset_unlock(struct file *fp, off_t val, int flags) 806 { 807 volatile short *flagsp; 808 short state; 809 810 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed")); 811 812 if ((flags & FOF_NOUPDATE) == 0) 813 atomic_store_long(&fp->f_offset, val); 814 if ((flags & FOF_NEXTOFF_R) != 0) 815 fp->f_nextoff[UIO_READ] = val; 816 if ((flags & FOF_NEXTOFF_W) != 0) 817 fp->f_nextoff[UIO_WRITE] = val; 818 819 if ((flags & FOF_NOLOCK) != 0) 820 return; 821 822 flagsp = &fp->f_vnread_flags; 823 state = atomic_load_16(flagsp); 824 if ((state & FOFFSET_LOCK_WAITING) == 0 && 825 atomic_cmpset_rel_16(flagsp, state, 0)) 826 return; 827 828 sleepq_lock(&fp->f_vnread_flags); 829 MPASS((fp->f_vnread_flags & FOFFSET_LOCKED) != 0); 830 MPASS((fp->f_vnread_flags & FOFFSET_LOCK_WAITING) != 0); 831 fp->f_vnread_flags = 0; 832 sleepq_broadcast(&fp->f_vnread_flags, SLEEPQ_SLEEP, 0, 0); 833 sleepq_release(&fp->f_vnread_flags); 834 } 835 #else 836 off_t 837 foffset_lock(struct file *fp, int flags) 838 { 839 struct mtx *mtxp; 840 off_t res; 841 842 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed")); 843 844 mtxp = mtx_pool_find(mtxpool_sleep, fp); 845 mtx_lock(mtxp); 846 if ((flags & FOF_NOLOCK) == 0) { 847 while (fp->f_vnread_flags & FOFFSET_LOCKED) { 848 fp->f_vnread_flags |= FOFFSET_LOCK_WAITING; 849 msleep(&fp->f_vnread_flags, mtxp, PUSER -1, 850 "vofflock", 0); 851 } 852 fp->f_vnread_flags |= FOFFSET_LOCKED; 853 } 854 res = fp->f_offset; 855 mtx_unlock(mtxp); 856 return (res); 857 } 858 859 void 860 foffset_unlock(struct file *fp, off_t val, int flags) 861 { 862 struct mtx *mtxp; 863 864 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed")); 865 866 mtxp = mtx_pool_find(mtxpool_sleep, fp); 867 mtx_lock(mtxp); 868 if ((flags & FOF_NOUPDATE) == 0) 869 fp->f_offset = val; 870 if ((flags & FOF_NEXTOFF_R) != 0) 871 fp->f_nextoff[UIO_READ] = val; 872 if ((flags & FOF_NEXTOFF_W) != 0) 873 fp->f_nextoff[UIO_WRITE] = val; 874 if ((flags & FOF_NOLOCK) == 0) { 875 KASSERT((fp->f_vnread_flags & FOFFSET_LOCKED) != 0, 876 ("Lost FOFFSET_LOCKED")); 877 if (fp->f_vnread_flags & FOFFSET_LOCK_WAITING) 878 wakeup(&fp->f_vnread_flags); 879 fp->f_vnread_flags = 0; 880 } 881 mtx_unlock(mtxp); 882 } 883 #endif 884 885 void 886 foffset_lock_uio(struct file *fp, struct uio *uio, int flags) 887 { 888 889 if ((flags & FOF_OFFSET) == 0) 890 uio->uio_offset = foffset_lock(fp, flags); 891 } 892 893 void 894 foffset_unlock_uio(struct file *fp, struct uio *uio, int flags) 895 { 896 897 if ((flags & FOF_OFFSET) == 0) 898 foffset_unlock(fp, uio->uio_offset, flags); 899 } 900 901 static int 902 get_advice(struct file *fp, struct uio *uio) 903 { 904 struct mtx *mtxp; 905 int ret; 906 907 ret = POSIX_FADV_NORMAL; 908 if (fp->f_advice == NULL || fp->f_vnode->v_type != VREG) 909 return (ret); 910 911 mtxp = mtx_pool_find(mtxpool_sleep, fp); 912 mtx_lock(mtxp); 913 if (fp->f_advice != NULL && 914 uio->uio_offset >= fp->f_advice->fa_start && 915 uio->uio_offset + uio->uio_resid <= fp->f_advice->fa_end) 916 ret = fp->f_advice->fa_advice; 917 mtx_unlock(mtxp); 918 return (ret); 919 } 920 921 static int 922 get_write_ioflag(struct file *fp) 923 { 924 int ioflag; 925 struct mount *mp; 926 struct vnode *vp; 927 928 ioflag = 0; 929 vp = fp->f_vnode; 930 mp = atomic_load_ptr(&vp->v_mount); 931 932 if ((fp->f_flag & O_DIRECT) != 0) 933 ioflag |= IO_DIRECT; 934 935 if ((fp->f_flag & O_FSYNC) != 0 || 936 (mp != NULL && (mp->mnt_flag & MNT_SYNCHRONOUS) != 0)) 937 ioflag |= IO_SYNC; 938 939 /* 940 * For O_DSYNC we set both IO_SYNC and IO_DATASYNC, so that VOP_WRITE() 941 * or VOP_DEALLOCATE() implementations that don't understand IO_DATASYNC 942 * fall back to full O_SYNC behavior. 943 */ 944 if ((fp->f_flag & O_DSYNC) != 0) 945 ioflag |= IO_SYNC | IO_DATASYNC; 946 947 return (ioflag); 948 } 949 950 int 951 vn_read_from_obj(struct vnode *vp, struct uio *uio) 952 { 953 vm_object_t obj; 954 vm_page_t ma[io_hold_cnt + 2]; 955 off_t off, vsz; 956 ssize_t resid; 957 int error, i, j; 958 959 MPASS(uio->uio_resid <= ptoa(io_hold_cnt + 2)); 960 obj = atomic_load_ptr(&vp->v_object); 961 if (obj == NULL) 962 return (EJUSTRETURN); 963 964 /* 965 * Depends on type stability of vm_objects. 966 */ 967 vm_object_pip_add(obj, 1); 968 if ((obj->flags & OBJ_DEAD) != 0) { 969 /* 970 * Note that object might be already reused from the 971 * vnode, and the OBJ_DEAD flag cleared. This is fine, 972 * we recheck for DOOMED vnode state after all pages 973 * are busied, and retract then. 974 * 975 * But we check for OBJ_DEAD to ensure that we do not 976 * busy pages while vm_object_terminate_pages() 977 * processes the queue. 978 */ 979 error = EJUSTRETURN; 980 goto out_pip; 981 } 982 983 resid = uio->uio_resid; 984 off = uio->uio_offset; 985 for (i = 0; resid > 0; i++) { 986 MPASS(i < io_hold_cnt + 2); 987 ma[i] = vm_page_grab_unlocked(obj, atop(off), 988 VM_ALLOC_NOCREAT | VM_ALLOC_SBUSY | VM_ALLOC_IGN_SBUSY | 989 VM_ALLOC_NOWAIT); 990 if (ma[i] == NULL) 991 break; 992 993 /* 994 * Skip invalid pages. Valid mask can be partial only 995 * at EOF, and we clip later. 996 */ 997 if (vm_page_none_valid(ma[i])) { 998 vm_page_sunbusy(ma[i]); 999 break; 1000 } 1001 1002 resid -= PAGE_SIZE; 1003 off += PAGE_SIZE; 1004 } 1005 if (i == 0) { 1006 error = EJUSTRETURN; 1007 goto out_pip; 1008 } 1009 1010 /* 1011 * Check VIRF_DOOMED after we busied our pages. Since 1012 * vgonel() terminates the vnode' vm_object, it cannot 1013 * process past pages busied by us. 1014 */ 1015 if (VN_IS_DOOMED(vp)) { 1016 error = EJUSTRETURN; 1017 goto out; 1018 } 1019 1020 resid = PAGE_SIZE - (uio->uio_offset & PAGE_MASK) + ptoa(i - 1); 1021 if (resid > uio->uio_resid) 1022 resid = uio->uio_resid; 1023 1024 /* 1025 * Unlocked read of vnp_size is safe because truncation cannot 1026 * pass busied page. But we load vnp_size into a local 1027 * variable so that possible concurrent extension does not 1028 * break calculation. 1029 */ 1030 #if defined(__powerpc__) && !defined(__powerpc64__) 1031 vsz = obj->un_pager.vnp.vnp_size; 1032 #else 1033 vsz = atomic_load_64(&obj->un_pager.vnp.vnp_size); 1034 #endif 1035 if (uio->uio_offset >= vsz) { 1036 error = EJUSTRETURN; 1037 goto out; 1038 } 1039 if (uio->uio_offset + resid > vsz) 1040 resid = vsz - uio->uio_offset; 1041 1042 error = vn_io_fault_pgmove(ma, uio->uio_offset & PAGE_MASK, resid, uio); 1043 1044 out: 1045 for (j = 0; j < i; j++) { 1046 if (error == 0) 1047 vm_page_reference(ma[j]); 1048 vm_page_sunbusy(ma[j]); 1049 } 1050 out_pip: 1051 vm_object_pip_wakeup(obj); 1052 if (error != 0) 1053 return (error); 1054 return (uio->uio_resid == 0 ? 0 : EJUSTRETURN); 1055 } 1056 1057 /* 1058 * File table vnode read routine. 1059 */ 1060 static int 1061 vn_read(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags, 1062 struct thread *td) 1063 { 1064 struct vnode *vp; 1065 off_t orig_offset; 1066 int error, ioflag; 1067 int advice; 1068 1069 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", 1070 uio->uio_td, td)); 1071 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET")); 1072 vp = fp->f_vnode; 1073 ioflag = 0; 1074 if (fp->f_flag & FNONBLOCK) 1075 ioflag |= IO_NDELAY; 1076 if (fp->f_flag & O_DIRECT) 1077 ioflag |= IO_DIRECT; 1078 1079 /* 1080 * Try to read from page cache. VIRF_DOOMED check is racy but 1081 * allows us to avoid unneeded work outright. 1082 */ 1083 if (vn_io_pgcache_read_enable && !mac_vnode_check_read_enabled() && 1084 (vn_irflag_read(vp) & (VIRF_DOOMED | VIRF_PGREAD)) == VIRF_PGREAD) { 1085 error = VOP_READ_PGCACHE(vp, uio, ioflag, fp->f_cred); 1086 if (error == 0) { 1087 fp->f_nextoff[UIO_READ] = uio->uio_offset; 1088 return (0); 1089 } 1090 if (error != EJUSTRETURN) 1091 return (error); 1092 } 1093 1094 advice = get_advice(fp, uio); 1095 vn_lock(vp, LK_SHARED | LK_RETRY); 1096 1097 switch (advice) { 1098 case POSIX_FADV_NORMAL: 1099 case POSIX_FADV_SEQUENTIAL: 1100 case POSIX_FADV_NOREUSE: 1101 ioflag |= sequential_heuristic(uio, fp); 1102 break; 1103 case POSIX_FADV_RANDOM: 1104 /* Disable read-ahead for random I/O. */ 1105 break; 1106 } 1107 orig_offset = uio->uio_offset; 1108 1109 #ifdef MAC 1110 error = mac_vnode_check_read(active_cred, fp->f_cred, vp); 1111 if (error == 0) 1112 #endif 1113 error = VOP_READ(vp, uio, ioflag, fp->f_cred); 1114 fp->f_nextoff[UIO_READ] = uio->uio_offset; 1115 VOP_UNLOCK(vp); 1116 if (error == 0 && advice == POSIX_FADV_NOREUSE && 1117 orig_offset != uio->uio_offset) 1118 /* 1119 * Use POSIX_FADV_DONTNEED to flush pages and buffers 1120 * for the backing file after a POSIX_FADV_NOREUSE 1121 * read(2). 1122 */ 1123 error = VOP_ADVISE(vp, orig_offset, uio->uio_offset - 1, 1124 POSIX_FADV_DONTNEED); 1125 return (error); 1126 } 1127 1128 /* 1129 * File table vnode write routine. 1130 */ 1131 static int 1132 vn_write(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags, 1133 struct thread *td) 1134 { 1135 struct vnode *vp; 1136 struct mount *mp; 1137 off_t orig_offset; 1138 int error, ioflag; 1139 int advice; 1140 bool need_finished_write; 1141 1142 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", 1143 uio->uio_td, td)); 1144 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET")); 1145 vp = fp->f_vnode; 1146 if (vp->v_type == VREG) 1147 bwillwrite(); 1148 ioflag = IO_UNIT; 1149 if (vp->v_type == VREG && (fp->f_flag & O_APPEND) != 0) 1150 ioflag |= IO_APPEND; 1151 if ((fp->f_flag & FNONBLOCK) != 0) 1152 ioflag |= IO_NDELAY; 1153 ioflag |= get_write_ioflag(fp); 1154 1155 mp = NULL; 1156 need_finished_write = false; 1157 if (vp->v_type != VCHR) { 1158 error = vn_start_write(vp, &mp, V_WAIT | V_PCATCH); 1159 if (error != 0) 1160 goto unlock; 1161 need_finished_write = true; 1162 } 1163 1164 advice = get_advice(fp, uio); 1165 1166 vn_lock(vp, vn_lktype_write(mp, vp) | LK_RETRY); 1167 switch (advice) { 1168 case POSIX_FADV_NORMAL: 1169 case POSIX_FADV_SEQUENTIAL: 1170 case POSIX_FADV_NOREUSE: 1171 ioflag |= sequential_heuristic(uio, fp); 1172 break; 1173 case POSIX_FADV_RANDOM: 1174 /* XXX: Is this correct? */ 1175 break; 1176 } 1177 orig_offset = uio->uio_offset; 1178 1179 #ifdef MAC 1180 error = mac_vnode_check_write(active_cred, fp->f_cred, vp); 1181 if (error == 0) 1182 #endif 1183 error = VOP_WRITE(vp, uio, ioflag, fp->f_cred); 1184 fp->f_nextoff[UIO_WRITE] = uio->uio_offset; 1185 VOP_UNLOCK(vp); 1186 if (need_finished_write) 1187 vn_finished_write(mp); 1188 if (error == 0 && advice == POSIX_FADV_NOREUSE && 1189 orig_offset != uio->uio_offset) 1190 /* 1191 * Use POSIX_FADV_DONTNEED to flush pages and buffers 1192 * for the backing file after a POSIX_FADV_NOREUSE 1193 * write(2). 1194 */ 1195 error = VOP_ADVISE(vp, orig_offset, uio->uio_offset - 1, 1196 POSIX_FADV_DONTNEED); 1197 unlock: 1198 return (error); 1199 } 1200 1201 /* 1202 * The vn_io_fault() is a wrapper around vn_read() and vn_write() to 1203 * prevent the following deadlock: 1204 * 1205 * Assume that the thread A reads from the vnode vp1 into userspace 1206 * buffer buf1 backed by the pages of vnode vp2. If a page in buf1 is 1207 * currently not resident, then system ends up with the call chain 1208 * vn_read() -> VOP_READ(vp1) -> uiomove() -> [Page Fault] -> 1209 * vm_fault(buf1) -> vnode_pager_getpages(vp2) -> VOP_GETPAGES(vp2) 1210 * which establishes lock order vp1->vn_lock, then vp2->vn_lock. 1211 * If, at the same time, thread B reads from vnode vp2 into buffer buf2 1212 * backed by the pages of vnode vp1, and some page in buf2 is not 1213 * resident, we get a reversed order vp2->vn_lock, then vp1->vn_lock. 1214 * 1215 * To prevent the lock order reversal and deadlock, vn_io_fault() does 1216 * not allow page faults to happen during VOP_READ() or VOP_WRITE(). 1217 * Instead, it first tries to do the whole range i/o with pagefaults 1218 * disabled. If all pages in the i/o buffer are resident and mapped, 1219 * VOP will succeed (ignoring the genuine filesystem errors). 1220 * Otherwise, we get back EFAULT, and vn_io_fault() falls back to do 1221 * i/o in chunks, with all pages in the chunk prefaulted and held 1222 * using vm_fault_quick_hold_pages(). 1223 * 1224 * Filesystems using this deadlock avoidance scheme should use the 1225 * array of the held pages from uio, saved in the curthread->td_ma, 1226 * instead of doing uiomove(). A helper function 1227 * vn_io_fault_uiomove() converts uiomove request into 1228 * uiomove_fromphys() over td_ma array. 1229 * 1230 * Since vnode locks do not cover the whole i/o anymore, rangelocks 1231 * make the current i/o request atomic with respect to other i/os and 1232 * truncations. 1233 */ 1234 1235 /* 1236 * Decode vn_io_fault_args and perform the corresponding i/o. 1237 */ 1238 static int 1239 vn_io_fault_doio(struct vn_io_fault_args *args, struct uio *uio, 1240 struct thread *td) 1241 { 1242 int error, save; 1243 1244 error = 0; 1245 save = vm_fault_disable_pagefaults(); 1246 switch (args->kind) { 1247 case VN_IO_FAULT_FOP: 1248 error = (args->args.fop_args.doio)(args->args.fop_args.fp, 1249 uio, args->cred, args->flags, td); 1250 break; 1251 case VN_IO_FAULT_VOP: 1252 if (uio->uio_rw == UIO_READ) { 1253 error = VOP_READ(args->args.vop_args.vp, uio, 1254 args->flags, args->cred); 1255 } else if (uio->uio_rw == UIO_WRITE) { 1256 error = VOP_WRITE(args->args.vop_args.vp, uio, 1257 args->flags, args->cred); 1258 } 1259 break; 1260 default: 1261 panic("vn_io_fault_doio: unknown kind of io %d %d", 1262 args->kind, uio->uio_rw); 1263 } 1264 vm_fault_enable_pagefaults(save); 1265 return (error); 1266 } 1267 1268 static int 1269 vn_io_fault_touch(char *base, const struct uio *uio) 1270 { 1271 int r; 1272 1273 r = fubyte(base); 1274 if (r == -1 || (uio->uio_rw == UIO_READ && subyte(base, r) == -1)) 1275 return (EFAULT); 1276 return (0); 1277 } 1278 1279 static int 1280 vn_io_fault_prefault_user(const struct uio *uio) 1281 { 1282 char *base; 1283 const struct iovec *iov; 1284 size_t len; 1285 ssize_t resid; 1286 int error, i; 1287 1288 KASSERT(uio->uio_segflg == UIO_USERSPACE, 1289 ("vn_io_fault_prefault userspace")); 1290 1291 error = i = 0; 1292 iov = uio->uio_iov; 1293 resid = uio->uio_resid; 1294 base = iov->iov_base; 1295 len = iov->iov_len; 1296 while (resid > 0) { 1297 error = vn_io_fault_touch(base, uio); 1298 if (error != 0) 1299 break; 1300 if (len < PAGE_SIZE) { 1301 if (len != 0) { 1302 error = vn_io_fault_touch(base + len - 1, uio); 1303 if (error != 0) 1304 break; 1305 resid -= len; 1306 } 1307 if (++i >= uio->uio_iovcnt) 1308 break; 1309 iov = uio->uio_iov + i; 1310 base = iov->iov_base; 1311 len = iov->iov_len; 1312 } else { 1313 len -= PAGE_SIZE; 1314 base += PAGE_SIZE; 1315 resid -= PAGE_SIZE; 1316 } 1317 } 1318 return (error); 1319 } 1320 1321 /* 1322 * Common code for vn_io_fault(), agnostic to the kind of i/o request. 1323 * Uses vn_io_fault_doio() to make the call to an actual i/o function. 1324 * Used from vn_rdwr() and vn_io_fault(), which encode the i/o request 1325 * into args and call vn_io_fault1() to handle faults during the user 1326 * mode buffer accesses. 1327 */ 1328 static int 1329 vn_io_fault1(struct vnode *vp, struct uio *uio, struct vn_io_fault_args *args, 1330 struct thread *td) 1331 { 1332 vm_page_t ma[io_hold_cnt + 2]; 1333 struct uio *uio_clone, short_uio; 1334 struct iovec short_iovec[1]; 1335 vm_page_t *prev_td_ma; 1336 vm_prot_t prot; 1337 vm_offset_t addr, end; 1338 size_t len, resid; 1339 ssize_t adv; 1340 int error, cnt, saveheld, prev_td_ma_cnt; 1341 1342 if (vn_io_fault_prefault) { 1343 error = vn_io_fault_prefault_user(uio); 1344 if (error != 0) 1345 return (error); /* Or ignore ? */ 1346 } 1347 1348 prot = uio->uio_rw == UIO_READ ? VM_PROT_WRITE : VM_PROT_READ; 1349 1350 /* 1351 * The UFS follows IO_UNIT directive and replays back both 1352 * uio_offset and uio_resid if an error is encountered during the 1353 * operation. But, since the iovec may be already advanced, 1354 * uio is still in an inconsistent state. 1355 * 1356 * Cache a copy of the original uio, which is advanced to the redo 1357 * point using UIO_NOCOPY below. 1358 */ 1359 uio_clone = cloneuio(uio); 1360 resid = uio->uio_resid; 1361 1362 short_uio.uio_segflg = UIO_USERSPACE; 1363 short_uio.uio_rw = uio->uio_rw; 1364 short_uio.uio_td = uio->uio_td; 1365 1366 error = vn_io_fault_doio(args, uio, td); 1367 if (error != EFAULT) 1368 goto out; 1369 1370 atomic_add_long(&vn_io_faults_cnt, 1); 1371 uio_clone->uio_segflg = UIO_NOCOPY; 1372 uiomove(NULL, resid - uio->uio_resid, uio_clone); 1373 uio_clone->uio_segflg = uio->uio_segflg; 1374 1375 saveheld = curthread_pflags_set(TDP_UIOHELD); 1376 prev_td_ma = td->td_ma; 1377 prev_td_ma_cnt = td->td_ma_cnt; 1378 1379 while (uio_clone->uio_resid != 0) { 1380 len = uio_clone->uio_iov->iov_len; 1381 if (len == 0) { 1382 KASSERT(uio_clone->uio_iovcnt >= 1, 1383 ("iovcnt underflow")); 1384 uio_clone->uio_iov++; 1385 uio_clone->uio_iovcnt--; 1386 continue; 1387 } 1388 if (len > ptoa(io_hold_cnt)) 1389 len = ptoa(io_hold_cnt); 1390 addr = (uintptr_t)uio_clone->uio_iov->iov_base; 1391 end = round_page(addr + len); 1392 if (end < addr) { 1393 error = EFAULT; 1394 break; 1395 } 1396 /* 1397 * A perfectly misaligned address and length could cause 1398 * both the start and the end of the chunk to use partial 1399 * page. +2 accounts for such a situation. 1400 */ 1401 cnt = vm_fault_quick_hold_pages(&td->td_proc->p_vmspace->vm_map, 1402 addr, len, prot, ma, io_hold_cnt + 2); 1403 if (cnt == -1) { 1404 error = EFAULT; 1405 break; 1406 } 1407 short_uio.uio_iov = &short_iovec[0]; 1408 short_iovec[0].iov_base = (void *)addr; 1409 short_uio.uio_iovcnt = 1; 1410 short_uio.uio_resid = short_iovec[0].iov_len = len; 1411 short_uio.uio_offset = uio_clone->uio_offset; 1412 td->td_ma = ma; 1413 td->td_ma_cnt = cnt; 1414 1415 error = vn_io_fault_doio(args, &short_uio, td); 1416 vm_page_unhold_pages(ma, cnt); 1417 adv = len - short_uio.uio_resid; 1418 1419 uio_clone->uio_iov->iov_base = 1420 (char *)uio_clone->uio_iov->iov_base + adv; 1421 uio_clone->uio_iov->iov_len -= adv; 1422 uio_clone->uio_resid -= adv; 1423 uio_clone->uio_offset += adv; 1424 1425 uio->uio_resid -= adv; 1426 uio->uio_offset += adv; 1427 1428 if (error != 0 || adv == 0) 1429 break; 1430 } 1431 td->td_ma = prev_td_ma; 1432 td->td_ma_cnt = prev_td_ma_cnt; 1433 curthread_pflags_restore(saveheld); 1434 out: 1435 free(uio_clone, M_IOV); 1436 return (error); 1437 } 1438 1439 static int 1440 vn_io_fault(struct file *fp, struct uio *uio, struct ucred *active_cred, 1441 int flags, struct thread *td) 1442 { 1443 fo_rdwr_t *doio; 1444 struct vnode *vp; 1445 void *rl_cookie; 1446 struct vn_io_fault_args args; 1447 int error; 1448 1449 doio = uio->uio_rw == UIO_READ ? vn_read : vn_write; 1450 vp = fp->f_vnode; 1451 1452 /* 1453 * The ability to read(2) on a directory has historically been 1454 * allowed for all users, but this can and has been the source of 1455 * at least one security issue in the past. As such, it is now hidden 1456 * away behind a sysctl for those that actually need it to use it, and 1457 * restricted to root when it's turned on to make it relatively safe to 1458 * leave on for longer sessions of need. 1459 */ 1460 if (vp->v_type == VDIR) { 1461 KASSERT(uio->uio_rw == UIO_READ, 1462 ("illegal write attempted on a directory")); 1463 if (!vfs_allow_read_dir) 1464 return (EISDIR); 1465 if ((error = priv_check(td, PRIV_VFS_READ_DIR)) != 0) 1466 return (EISDIR); 1467 } 1468 1469 foffset_lock_uio(fp, uio, flags); 1470 if (do_vn_io_fault(vp, uio)) { 1471 args.kind = VN_IO_FAULT_FOP; 1472 args.args.fop_args.fp = fp; 1473 args.args.fop_args.doio = doio; 1474 args.cred = active_cred; 1475 args.flags = flags | FOF_OFFSET; 1476 if (uio->uio_rw == UIO_READ) { 1477 rl_cookie = vn_rangelock_rlock(vp, uio->uio_offset, 1478 uio->uio_offset + uio->uio_resid); 1479 } else if ((fp->f_flag & O_APPEND) != 0 || 1480 (flags & FOF_OFFSET) == 0) { 1481 /* For appenders, punt and lock the whole range. */ 1482 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 1483 } else { 1484 rl_cookie = vn_rangelock_wlock(vp, uio->uio_offset, 1485 uio->uio_offset + uio->uio_resid); 1486 } 1487 error = vn_io_fault1(vp, uio, &args, td); 1488 vn_rangelock_unlock(vp, rl_cookie); 1489 } else { 1490 error = doio(fp, uio, active_cred, flags | FOF_OFFSET, td); 1491 } 1492 foffset_unlock_uio(fp, uio, flags); 1493 return (error); 1494 } 1495 1496 /* 1497 * Helper function to perform the requested uiomove operation using 1498 * the held pages for io->uio_iov[0].iov_base buffer instead of 1499 * copyin/copyout. Access to the pages with uiomove_fromphys() 1500 * instead of iov_base prevents page faults that could occur due to 1501 * pmap_collect() invalidating the mapping created by 1502 * vm_fault_quick_hold_pages(), or pageout daemon, page laundry or 1503 * object cleanup revoking the write access from page mappings. 1504 * 1505 * Filesystems specified MNTK_NO_IOPF shall use vn_io_fault_uiomove() 1506 * instead of plain uiomove(). 1507 */ 1508 int 1509 vn_io_fault_uiomove(char *data, int xfersize, struct uio *uio) 1510 { 1511 struct uio transp_uio; 1512 struct iovec transp_iov[1]; 1513 struct thread *td; 1514 size_t adv; 1515 int error, pgadv; 1516 1517 td = curthread; 1518 if ((td->td_pflags & TDP_UIOHELD) == 0 || 1519 uio->uio_segflg != UIO_USERSPACE) 1520 return (uiomove(data, xfersize, uio)); 1521 1522 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt)); 1523 transp_iov[0].iov_base = data; 1524 transp_uio.uio_iov = &transp_iov[0]; 1525 transp_uio.uio_iovcnt = 1; 1526 if (xfersize > uio->uio_resid) 1527 xfersize = uio->uio_resid; 1528 transp_uio.uio_resid = transp_iov[0].iov_len = xfersize; 1529 transp_uio.uio_offset = 0; 1530 transp_uio.uio_segflg = UIO_SYSSPACE; 1531 /* 1532 * Since transp_iov points to data, and td_ma page array 1533 * corresponds to original uio->uio_iov, we need to invert the 1534 * direction of the i/o operation as passed to 1535 * uiomove_fromphys(). 1536 */ 1537 switch (uio->uio_rw) { 1538 case UIO_WRITE: 1539 transp_uio.uio_rw = UIO_READ; 1540 break; 1541 case UIO_READ: 1542 transp_uio.uio_rw = UIO_WRITE; 1543 break; 1544 } 1545 transp_uio.uio_td = uio->uio_td; 1546 error = uiomove_fromphys(td->td_ma, 1547 ((vm_offset_t)uio->uio_iov->iov_base) & PAGE_MASK, 1548 xfersize, &transp_uio); 1549 adv = xfersize - transp_uio.uio_resid; 1550 pgadv = 1551 (((vm_offset_t)uio->uio_iov->iov_base + adv) >> PAGE_SHIFT) - 1552 (((vm_offset_t)uio->uio_iov->iov_base) >> PAGE_SHIFT); 1553 td->td_ma += pgadv; 1554 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt, 1555 pgadv)); 1556 td->td_ma_cnt -= pgadv; 1557 uio->uio_iov->iov_base = (char *)uio->uio_iov->iov_base + adv; 1558 uio->uio_iov->iov_len -= adv; 1559 uio->uio_resid -= adv; 1560 uio->uio_offset += adv; 1561 return (error); 1562 } 1563 1564 int 1565 vn_io_fault_pgmove(vm_page_t ma[], vm_offset_t offset, int xfersize, 1566 struct uio *uio) 1567 { 1568 struct thread *td; 1569 vm_offset_t iov_base; 1570 int cnt, pgadv; 1571 1572 td = curthread; 1573 if ((td->td_pflags & TDP_UIOHELD) == 0 || 1574 uio->uio_segflg != UIO_USERSPACE) 1575 return (uiomove_fromphys(ma, offset, xfersize, uio)); 1576 1577 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt)); 1578 cnt = xfersize > uio->uio_resid ? uio->uio_resid : xfersize; 1579 iov_base = (vm_offset_t)uio->uio_iov->iov_base; 1580 switch (uio->uio_rw) { 1581 case UIO_WRITE: 1582 pmap_copy_pages(td->td_ma, iov_base & PAGE_MASK, ma, 1583 offset, cnt); 1584 break; 1585 case UIO_READ: 1586 pmap_copy_pages(ma, offset, td->td_ma, iov_base & PAGE_MASK, 1587 cnt); 1588 break; 1589 } 1590 pgadv = ((iov_base + cnt) >> PAGE_SHIFT) - (iov_base >> PAGE_SHIFT); 1591 td->td_ma += pgadv; 1592 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt, 1593 pgadv)); 1594 td->td_ma_cnt -= pgadv; 1595 uio->uio_iov->iov_base = (char *)(iov_base + cnt); 1596 uio->uio_iov->iov_len -= cnt; 1597 uio->uio_resid -= cnt; 1598 uio->uio_offset += cnt; 1599 return (0); 1600 } 1601 1602 /* 1603 * File table truncate routine. 1604 */ 1605 static int 1606 vn_truncate(struct file *fp, off_t length, struct ucred *active_cred, 1607 struct thread *td) 1608 { 1609 struct mount *mp; 1610 struct vnode *vp; 1611 void *rl_cookie; 1612 int error; 1613 1614 vp = fp->f_vnode; 1615 1616 retry: 1617 /* 1618 * Lock the whole range for truncation. Otherwise split i/o 1619 * might happen partly before and partly after the truncation. 1620 */ 1621 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 1622 error = vn_start_write(vp, &mp, V_WAIT | V_PCATCH); 1623 if (error) 1624 goto out1; 1625 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1626 AUDIT_ARG_VNODE1(vp); 1627 if (vp->v_type == VDIR) { 1628 error = EISDIR; 1629 goto out; 1630 } 1631 #ifdef MAC 1632 error = mac_vnode_check_write(active_cred, fp->f_cred, vp); 1633 if (error) 1634 goto out; 1635 #endif 1636 error = vn_truncate_locked(vp, length, (fp->f_flag & O_FSYNC) != 0, 1637 fp->f_cred); 1638 out: 1639 VOP_UNLOCK(vp); 1640 vn_finished_write(mp); 1641 out1: 1642 vn_rangelock_unlock(vp, rl_cookie); 1643 if (error == ERELOOKUP) 1644 goto retry; 1645 return (error); 1646 } 1647 1648 /* 1649 * Truncate a file that is already locked. 1650 */ 1651 int 1652 vn_truncate_locked(struct vnode *vp, off_t length, bool sync, 1653 struct ucred *cred) 1654 { 1655 struct vattr vattr; 1656 int error; 1657 1658 error = VOP_ADD_WRITECOUNT(vp, 1); 1659 if (error == 0) { 1660 VATTR_NULL(&vattr); 1661 vattr.va_size = length; 1662 if (sync) 1663 vattr.va_vaflags |= VA_SYNC; 1664 error = VOP_SETATTR(vp, &vattr, cred); 1665 VOP_ADD_WRITECOUNT_CHECKED(vp, -1); 1666 } 1667 return (error); 1668 } 1669 1670 /* 1671 * File table vnode stat routine. 1672 */ 1673 int 1674 vn_statfile(struct file *fp, struct stat *sb, struct ucred *active_cred) 1675 { 1676 struct vnode *vp = fp->f_vnode; 1677 int error; 1678 1679 vn_lock(vp, LK_SHARED | LK_RETRY); 1680 error = VOP_STAT(vp, sb, active_cred, fp->f_cred); 1681 VOP_UNLOCK(vp); 1682 1683 return (error); 1684 } 1685 1686 /* 1687 * File table vnode ioctl routine. 1688 */ 1689 static int 1690 vn_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 1691 struct thread *td) 1692 { 1693 struct vnode *vp; 1694 struct fiobmap2_arg *bmarg; 1695 off_t size; 1696 int error; 1697 1698 vp = fp->f_vnode; 1699 switch (vp->v_type) { 1700 case VDIR: 1701 case VREG: 1702 switch (com) { 1703 case FIONREAD: 1704 error = vn_getsize(vp, &size, active_cred); 1705 if (error == 0) 1706 *(int *)data = size - fp->f_offset; 1707 return (error); 1708 case FIOBMAP2: 1709 bmarg = (struct fiobmap2_arg *)data; 1710 vn_lock(vp, LK_SHARED | LK_RETRY); 1711 #ifdef MAC 1712 error = mac_vnode_check_read(active_cred, fp->f_cred, 1713 vp); 1714 if (error == 0) 1715 #endif 1716 error = VOP_BMAP(vp, bmarg->bn, NULL, 1717 &bmarg->bn, &bmarg->runp, &bmarg->runb); 1718 VOP_UNLOCK(vp); 1719 return (error); 1720 case FIONBIO: 1721 case FIOASYNC: 1722 return (0); 1723 default: 1724 return (VOP_IOCTL(vp, com, data, fp->f_flag, 1725 active_cred, td)); 1726 } 1727 break; 1728 case VCHR: 1729 return (VOP_IOCTL(vp, com, data, fp->f_flag, 1730 active_cred, td)); 1731 default: 1732 return (ENOTTY); 1733 } 1734 } 1735 1736 /* 1737 * File table vnode poll routine. 1738 */ 1739 static int 1740 vn_poll(struct file *fp, int events, struct ucred *active_cred, 1741 struct thread *td) 1742 { 1743 struct vnode *vp; 1744 int error; 1745 1746 vp = fp->f_vnode; 1747 #if defined(MAC) || defined(AUDIT) 1748 if (AUDITING_TD(td) || mac_vnode_check_poll_enabled()) { 1749 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1750 AUDIT_ARG_VNODE1(vp); 1751 error = mac_vnode_check_poll(active_cred, fp->f_cred, vp); 1752 VOP_UNLOCK(vp); 1753 if (error != 0) 1754 return (error); 1755 } 1756 #endif 1757 error = VOP_POLL(vp, events, fp->f_cred, td); 1758 return (error); 1759 } 1760 1761 /* 1762 * Acquire the requested lock and then check for validity. LK_RETRY 1763 * permits vn_lock to return doomed vnodes. 1764 */ 1765 static int __noinline 1766 _vn_lock_fallback(struct vnode *vp, int flags, const char *file, int line, 1767 int error) 1768 { 1769 1770 KASSERT((flags & LK_RETRY) == 0 || error == 0, 1771 ("vn_lock: error %d incompatible with flags %#x", error, flags)); 1772 1773 if (error == 0) 1774 VNASSERT(VN_IS_DOOMED(vp), vp, ("vnode not doomed")); 1775 1776 if ((flags & LK_RETRY) == 0) { 1777 if (error == 0) { 1778 VOP_UNLOCK(vp); 1779 error = ENOENT; 1780 } 1781 return (error); 1782 } 1783 1784 /* 1785 * LK_RETRY case. 1786 * 1787 * Nothing to do if we got the lock. 1788 */ 1789 if (error == 0) 1790 return (0); 1791 1792 /* 1793 * Interlock was dropped by the call in _vn_lock. 1794 */ 1795 flags &= ~LK_INTERLOCK; 1796 do { 1797 error = VOP_LOCK1(vp, flags, file, line); 1798 } while (error != 0); 1799 return (0); 1800 } 1801 1802 int 1803 _vn_lock(struct vnode *vp, int flags, const char *file, int line) 1804 { 1805 int error; 1806 1807 VNASSERT((flags & LK_TYPE_MASK) != 0, vp, 1808 ("vn_lock: no locktype (%d passed)", flags)); 1809 VNPASS(vp->v_holdcnt > 0, vp); 1810 error = VOP_LOCK1(vp, flags, file, line); 1811 if (__predict_false(error != 0 || VN_IS_DOOMED(vp))) 1812 return (_vn_lock_fallback(vp, flags, file, line, error)); 1813 return (0); 1814 } 1815 1816 /* 1817 * File table vnode close routine. 1818 */ 1819 static int 1820 vn_closefile(struct file *fp, struct thread *td) 1821 { 1822 struct vnode *vp; 1823 struct flock lf; 1824 int error; 1825 bool ref; 1826 1827 vp = fp->f_vnode; 1828 fp->f_ops = &badfileops; 1829 ref = (fp->f_flag & FHASLOCK) != 0; 1830 1831 error = vn_close1(vp, fp->f_flag, fp->f_cred, td, ref); 1832 1833 if (__predict_false(ref)) { 1834 lf.l_whence = SEEK_SET; 1835 lf.l_start = 0; 1836 lf.l_len = 0; 1837 lf.l_type = F_UNLCK; 1838 (void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, F_FLOCK); 1839 vrele(vp); 1840 } 1841 return (error); 1842 } 1843 1844 /* 1845 * Preparing to start a filesystem write operation. If the operation is 1846 * permitted, then we bump the count of operations in progress and 1847 * proceed. If a suspend request is in progress, we wait until the 1848 * suspension is over, and then proceed. 1849 */ 1850 static int 1851 vn_start_write_refed(struct mount *mp, int flags, bool mplocked) 1852 { 1853 struct mount_pcpu *mpcpu; 1854 int error, mflags; 1855 1856 if (__predict_true(!mplocked) && (flags & V_XSLEEP) == 0 && 1857 vfs_op_thread_enter(mp, mpcpu)) { 1858 MPASS((mp->mnt_kern_flag & MNTK_SUSPEND) == 0); 1859 vfs_mp_count_add_pcpu(mpcpu, writeopcount, 1); 1860 vfs_op_thread_exit(mp, mpcpu); 1861 return (0); 1862 } 1863 1864 if (mplocked) 1865 mtx_assert(MNT_MTX(mp), MA_OWNED); 1866 else 1867 MNT_ILOCK(mp); 1868 1869 error = 0; 1870 1871 /* 1872 * Check on status of suspension. 1873 */ 1874 if ((curthread->td_pflags & TDP_IGNSUSP) == 0 || 1875 mp->mnt_susp_owner != curthread) { 1876 mflags = 0; 1877 if ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0) { 1878 if (flags & V_PCATCH) 1879 mflags |= PCATCH; 1880 } 1881 mflags |= (PUSER - 1); 1882 while ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { 1883 if ((flags & V_NOWAIT) != 0) { 1884 error = EWOULDBLOCK; 1885 goto unlock; 1886 } 1887 error = msleep(&mp->mnt_flag, MNT_MTX(mp), mflags, 1888 "suspfs", 0); 1889 if (error != 0) 1890 goto unlock; 1891 } 1892 } 1893 if ((flags & V_XSLEEP) != 0) 1894 goto unlock; 1895 mp->mnt_writeopcount++; 1896 unlock: 1897 if (error != 0 || (flags & V_XSLEEP) != 0) 1898 MNT_REL(mp); 1899 MNT_IUNLOCK(mp); 1900 return (error); 1901 } 1902 1903 int 1904 vn_start_write(struct vnode *vp, struct mount **mpp, int flags) 1905 { 1906 struct mount *mp; 1907 int error; 1908 1909 KASSERT((flags & ~V_VALID_FLAGS) == 0, 1910 ("%s: invalid flags passed %d\n", __func__, flags)); 1911 1912 error = 0; 1913 /* 1914 * If a vnode is provided, get and return the mount point that 1915 * to which it will write. 1916 */ 1917 if (vp != NULL) { 1918 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) { 1919 *mpp = NULL; 1920 if (error != EOPNOTSUPP) 1921 return (error); 1922 return (0); 1923 } 1924 } 1925 if ((mp = *mpp) == NULL) 1926 return (0); 1927 1928 /* 1929 * VOP_GETWRITEMOUNT() returns with the mp refcount held through 1930 * a vfs_ref(). 1931 * As long as a vnode is not provided we need to acquire a 1932 * refcount for the provided mountpoint too, in order to 1933 * emulate a vfs_ref(). 1934 */ 1935 if (vp == NULL) 1936 vfs_ref(mp); 1937 1938 error = vn_start_write_refed(mp, flags, false); 1939 if (error != 0 && (flags & V_NOWAIT) == 0) 1940 *mpp = NULL; 1941 return (error); 1942 } 1943 1944 /* 1945 * Secondary suspension. Used by operations such as vop_inactive 1946 * routines that are needed by the higher level functions. These 1947 * are allowed to proceed until all the higher level functions have 1948 * completed (indicated by mnt_writeopcount dropping to zero). At that 1949 * time, these operations are halted until the suspension is over. 1950 */ 1951 int 1952 vn_start_secondary_write(struct vnode *vp, struct mount **mpp, int flags) 1953 { 1954 struct mount *mp; 1955 int error, mflags; 1956 1957 KASSERT((flags & (~V_VALID_FLAGS | V_XSLEEP)) == 0, 1958 ("%s: invalid flags passed %d\n", __func__, flags)); 1959 1960 retry: 1961 if (vp != NULL) { 1962 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) { 1963 *mpp = NULL; 1964 if (error != EOPNOTSUPP) 1965 return (error); 1966 return (0); 1967 } 1968 } 1969 /* 1970 * If we are not suspended or have not yet reached suspended 1971 * mode, then let the operation proceed. 1972 */ 1973 if ((mp = *mpp) == NULL) 1974 return (0); 1975 1976 /* 1977 * VOP_GETWRITEMOUNT() returns with the mp refcount held through 1978 * a vfs_ref(). 1979 * As long as a vnode is not provided we need to acquire a 1980 * refcount for the provided mountpoint too, in order to 1981 * emulate a vfs_ref(). 1982 */ 1983 MNT_ILOCK(mp); 1984 if (vp == NULL) 1985 MNT_REF(mp); 1986 if ((mp->mnt_kern_flag & (MNTK_SUSPENDED | MNTK_SUSPEND2)) == 0) { 1987 mp->mnt_secondary_writes++; 1988 mp->mnt_secondary_accwrites++; 1989 MNT_IUNLOCK(mp); 1990 return (0); 1991 } 1992 if ((flags & V_NOWAIT) != 0) { 1993 MNT_REL(mp); 1994 MNT_IUNLOCK(mp); 1995 *mpp = NULL; 1996 return (EWOULDBLOCK); 1997 } 1998 /* 1999 * Wait for the suspension to finish. 2000 */ 2001 mflags = 0; 2002 if ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0) { 2003 if ((flags & V_PCATCH) != 0) 2004 mflags |= PCATCH; 2005 } 2006 mflags |= (PUSER - 1) | PDROP; 2007 error = msleep(&mp->mnt_flag, MNT_MTX(mp), mflags, "suspfs", 0); 2008 vfs_rel(mp); 2009 if (error == 0) 2010 goto retry; 2011 *mpp = NULL; 2012 return (error); 2013 } 2014 2015 /* 2016 * Filesystem write operation has completed. If we are suspending and this 2017 * operation is the last one, notify the suspender that the suspension is 2018 * now in effect. 2019 */ 2020 void 2021 vn_finished_write(struct mount *mp) 2022 { 2023 struct mount_pcpu *mpcpu; 2024 int c; 2025 2026 if (mp == NULL) 2027 return; 2028 2029 if (vfs_op_thread_enter(mp, mpcpu)) { 2030 vfs_mp_count_sub_pcpu(mpcpu, writeopcount, 1); 2031 vfs_mp_count_sub_pcpu(mpcpu, ref, 1); 2032 vfs_op_thread_exit(mp, mpcpu); 2033 return; 2034 } 2035 2036 MNT_ILOCK(mp); 2037 vfs_assert_mount_counters(mp); 2038 MNT_REL(mp); 2039 c = --mp->mnt_writeopcount; 2040 if (mp->mnt_vfs_ops == 0) { 2041 MPASS((mp->mnt_kern_flag & MNTK_SUSPEND) == 0); 2042 MNT_IUNLOCK(mp); 2043 return; 2044 } 2045 if (c < 0) 2046 vfs_dump_mount_counters(mp); 2047 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && c == 0) 2048 wakeup(&mp->mnt_writeopcount); 2049 MNT_IUNLOCK(mp); 2050 } 2051 2052 /* 2053 * Filesystem secondary write operation has completed. If we are 2054 * suspending and this operation is the last one, notify the suspender 2055 * that the suspension is now in effect. 2056 */ 2057 void 2058 vn_finished_secondary_write(struct mount *mp) 2059 { 2060 if (mp == NULL) 2061 return; 2062 MNT_ILOCK(mp); 2063 MNT_REL(mp); 2064 mp->mnt_secondary_writes--; 2065 if (mp->mnt_secondary_writes < 0) 2066 panic("vn_finished_secondary_write: neg cnt"); 2067 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && 2068 mp->mnt_secondary_writes <= 0) 2069 wakeup(&mp->mnt_secondary_writes); 2070 MNT_IUNLOCK(mp); 2071 } 2072 2073 /* 2074 * Request a filesystem to suspend write operations. 2075 */ 2076 int 2077 vfs_write_suspend(struct mount *mp, int flags) 2078 { 2079 int error; 2080 2081 vfs_op_enter(mp); 2082 2083 MNT_ILOCK(mp); 2084 vfs_assert_mount_counters(mp); 2085 if (mp->mnt_susp_owner == curthread) { 2086 vfs_op_exit_locked(mp); 2087 MNT_IUNLOCK(mp); 2088 return (EALREADY); 2089 } 2090 while (mp->mnt_kern_flag & MNTK_SUSPEND) 2091 msleep(&mp->mnt_flag, MNT_MTX(mp), PUSER - 1, "wsuspfs", 0); 2092 2093 /* 2094 * Unmount holds a write reference on the mount point. If we 2095 * own busy reference and drain for writers, we deadlock with 2096 * the reference draining in the unmount path. Callers of 2097 * vfs_write_suspend() must specify VS_SKIP_UNMOUNT if 2098 * vfs_busy() reference is owned and caller is not in the 2099 * unmount context. 2100 */ 2101 if ((flags & VS_SKIP_UNMOUNT) != 0 && 2102 (mp->mnt_kern_flag & MNTK_UNMOUNT) != 0) { 2103 vfs_op_exit_locked(mp); 2104 MNT_IUNLOCK(mp); 2105 return (EBUSY); 2106 } 2107 2108 mp->mnt_kern_flag |= MNTK_SUSPEND; 2109 mp->mnt_susp_owner = curthread; 2110 if (mp->mnt_writeopcount > 0) 2111 (void) msleep(&mp->mnt_writeopcount, 2112 MNT_MTX(mp), (PUSER - 1)|PDROP, "suspwt", 0); 2113 else 2114 MNT_IUNLOCK(mp); 2115 if ((error = VFS_SYNC(mp, MNT_SUSPEND)) != 0) { 2116 vfs_write_resume(mp, 0); 2117 /* vfs_write_resume does vfs_op_exit() for us */ 2118 } 2119 return (error); 2120 } 2121 2122 /* 2123 * Request a filesystem to resume write operations. 2124 */ 2125 void 2126 vfs_write_resume(struct mount *mp, int flags) 2127 { 2128 2129 MNT_ILOCK(mp); 2130 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { 2131 KASSERT(mp->mnt_susp_owner == curthread, ("mnt_susp_owner")); 2132 mp->mnt_kern_flag &= ~(MNTK_SUSPEND | MNTK_SUSPEND2 | 2133 MNTK_SUSPENDED); 2134 mp->mnt_susp_owner = NULL; 2135 wakeup(&mp->mnt_writeopcount); 2136 wakeup(&mp->mnt_flag); 2137 curthread->td_pflags &= ~TDP_IGNSUSP; 2138 if ((flags & VR_START_WRITE) != 0) { 2139 MNT_REF(mp); 2140 mp->mnt_writeopcount++; 2141 } 2142 MNT_IUNLOCK(mp); 2143 if ((flags & VR_NO_SUSPCLR) == 0) 2144 VFS_SUSP_CLEAN(mp); 2145 vfs_op_exit(mp); 2146 } else if ((flags & VR_START_WRITE) != 0) { 2147 MNT_REF(mp); 2148 vn_start_write_refed(mp, 0, true); 2149 } else { 2150 MNT_IUNLOCK(mp); 2151 } 2152 } 2153 2154 /* 2155 * Helper loop around vfs_write_suspend() for filesystem unmount VFS 2156 * methods. 2157 */ 2158 int 2159 vfs_write_suspend_umnt(struct mount *mp) 2160 { 2161 int error; 2162 2163 KASSERT((curthread->td_pflags & TDP_IGNSUSP) == 0, 2164 ("vfs_write_suspend_umnt: recursed")); 2165 2166 /* dounmount() already called vn_start_write(). */ 2167 for (;;) { 2168 vn_finished_write(mp); 2169 error = vfs_write_suspend(mp, 0); 2170 if (error != 0) { 2171 vn_start_write(NULL, &mp, V_WAIT); 2172 return (error); 2173 } 2174 MNT_ILOCK(mp); 2175 if ((mp->mnt_kern_flag & MNTK_SUSPENDED) != 0) 2176 break; 2177 MNT_IUNLOCK(mp); 2178 vn_start_write(NULL, &mp, V_WAIT); 2179 } 2180 mp->mnt_kern_flag &= ~(MNTK_SUSPENDED | MNTK_SUSPEND2); 2181 wakeup(&mp->mnt_flag); 2182 MNT_IUNLOCK(mp); 2183 curthread->td_pflags |= TDP_IGNSUSP; 2184 return (0); 2185 } 2186 2187 /* 2188 * Implement kqueues for files by translating it to vnode operation. 2189 */ 2190 static int 2191 vn_kqfilter(struct file *fp, struct knote *kn) 2192 { 2193 2194 return (VOP_KQFILTER(fp->f_vnode, kn)); 2195 } 2196 2197 int 2198 vn_kqfilter_opath(struct file *fp, struct knote *kn) 2199 { 2200 if ((fp->f_flag & FKQALLOWED) == 0) 2201 return (EBADF); 2202 return (vn_kqfilter(fp, kn)); 2203 } 2204 2205 /* 2206 * Simplified in-kernel wrapper calls for extended attribute access. 2207 * Both calls pass in a NULL credential, authorizing as "kernel" access. 2208 * Set IO_NODELOCKED in ioflg if the vnode is already locked. 2209 */ 2210 int 2211 vn_extattr_get(struct vnode *vp, int ioflg, int attrnamespace, 2212 const char *attrname, int *buflen, char *buf, struct thread *td) 2213 { 2214 struct uio auio; 2215 struct iovec iov; 2216 int error; 2217 2218 iov.iov_len = *buflen; 2219 iov.iov_base = buf; 2220 2221 auio.uio_iov = &iov; 2222 auio.uio_iovcnt = 1; 2223 auio.uio_rw = UIO_READ; 2224 auio.uio_segflg = UIO_SYSSPACE; 2225 auio.uio_td = td; 2226 auio.uio_offset = 0; 2227 auio.uio_resid = *buflen; 2228 2229 if ((ioflg & IO_NODELOCKED) == 0) 2230 vn_lock(vp, LK_SHARED | LK_RETRY); 2231 2232 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 2233 2234 /* authorize attribute retrieval as kernel */ 2235 error = VOP_GETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, NULL, 2236 td); 2237 2238 if ((ioflg & IO_NODELOCKED) == 0) 2239 VOP_UNLOCK(vp); 2240 2241 if (error == 0) { 2242 *buflen = *buflen - auio.uio_resid; 2243 } 2244 2245 return (error); 2246 } 2247 2248 /* 2249 * XXX failure mode if partially written? 2250 */ 2251 int 2252 vn_extattr_set(struct vnode *vp, int ioflg, int attrnamespace, 2253 const char *attrname, int buflen, char *buf, struct thread *td) 2254 { 2255 struct uio auio; 2256 struct iovec iov; 2257 struct mount *mp; 2258 int error; 2259 2260 iov.iov_len = buflen; 2261 iov.iov_base = buf; 2262 2263 auio.uio_iov = &iov; 2264 auio.uio_iovcnt = 1; 2265 auio.uio_rw = UIO_WRITE; 2266 auio.uio_segflg = UIO_SYSSPACE; 2267 auio.uio_td = td; 2268 auio.uio_offset = 0; 2269 auio.uio_resid = buflen; 2270 2271 if ((ioflg & IO_NODELOCKED) == 0) { 2272 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) 2273 return (error); 2274 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2275 } 2276 2277 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 2278 2279 /* authorize attribute setting as kernel */ 2280 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, td); 2281 2282 if ((ioflg & IO_NODELOCKED) == 0) { 2283 vn_finished_write(mp); 2284 VOP_UNLOCK(vp); 2285 } 2286 2287 return (error); 2288 } 2289 2290 int 2291 vn_extattr_rm(struct vnode *vp, int ioflg, int attrnamespace, 2292 const char *attrname, struct thread *td) 2293 { 2294 struct mount *mp; 2295 int error; 2296 2297 if ((ioflg & IO_NODELOCKED) == 0) { 2298 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) 2299 return (error); 2300 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2301 } 2302 2303 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 2304 2305 /* authorize attribute removal as kernel */ 2306 error = VOP_DELETEEXTATTR(vp, attrnamespace, attrname, NULL, td); 2307 if (error == EOPNOTSUPP) 2308 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, NULL, 2309 NULL, td); 2310 2311 if ((ioflg & IO_NODELOCKED) == 0) { 2312 vn_finished_write(mp); 2313 VOP_UNLOCK(vp); 2314 } 2315 2316 return (error); 2317 } 2318 2319 static int 2320 vn_get_ino_alloc_vget(struct mount *mp, void *arg, int lkflags, 2321 struct vnode **rvp) 2322 { 2323 2324 return (VFS_VGET(mp, *(ino_t *)arg, lkflags, rvp)); 2325 } 2326 2327 int 2328 vn_vget_ino(struct vnode *vp, ino_t ino, int lkflags, struct vnode **rvp) 2329 { 2330 2331 return (vn_vget_ino_gen(vp, vn_get_ino_alloc_vget, &ino, 2332 lkflags, rvp)); 2333 } 2334 2335 int 2336 vn_vget_ino_gen(struct vnode *vp, vn_get_ino_t alloc, void *alloc_arg, 2337 int lkflags, struct vnode **rvp) 2338 { 2339 struct mount *mp; 2340 int ltype, error; 2341 2342 ASSERT_VOP_LOCKED(vp, "vn_vget_ino_get"); 2343 mp = vp->v_mount; 2344 ltype = VOP_ISLOCKED(vp); 2345 KASSERT(ltype == LK_EXCLUSIVE || ltype == LK_SHARED, 2346 ("vn_vget_ino: vp not locked")); 2347 error = vfs_busy(mp, MBF_NOWAIT); 2348 if (error != 0) { 2349 vfs_ref(mp); 2350 VOP_UNLOCK(vp); 2351 error = vfs_busy(mp, 0); 2352 vn_lock(vp, ltype | LK_RETRY); 2353 vfs_rel(mp); 2354 if (error != 0) 2355 return (ENOENT); 2356 if (VN_IS_DOOMED(vp)) { 2357 vfs_unbusy(mp); 2358 return (ENOENT); 2359 } 2360 } 2361 VOP_UNLOCK(vp); 2362 error = alloc(mp, alloc_arg, lkflags, rvp); 2363 vfs_unbusy(mp); 2364 if (error != 0 || *rvp != vp) 2365 vn_lock(vp, ltype | LK_RETRY); 2366 if (VN_IS_DOOMED(vp)) { 2367 if (error == 0) { 2368 if (*rvp == vp) 2369 vunref(vp); 2370 else 2371 vput(*rvp); 2372 } 2373 error = ENOENT; 2374 } 2375 return (error); 2376 } 2377 2378 static void 2379 vn_send_sigxfsz(struct proc *p) 2380 { 2381 PROC_LOCK(p); 2382 kern_psignal(p, SIGXFSZ); 2383 PROC_UNLOCK(p); 2384 } 2385 2386 int 2387 vn_rlimit_trunc(u_quad_t size, struct thread *td) 2388 { 2389 if (size <= lim_cur(td, RLIMIT_FSIZE)) 2390 return (0); 2391 vn_send_sigxfsz(td->td_proc); 2392 return (EFBIG); 2393 } 2394 2395 static int 2396 vn_rlimit_fsizex1(const struct vnode *vp, struct uio *uio, off_t maxfsz, 2397 bool adj, struct thread *td) 2398 { 2399 off_t lim; 2400 bool ktr_write; 2401 2402 if (vp->v_type != VREG) 2403 return (0); 2404 2405 /* 2406 * Handle file system maximum file size. 2407 */ 2408 if (maxfsz != 0 && uio->uio_offset + uio->uio_resid > maxfsz) { 2409 if (!adj || uio->uio_offset >= maxfsz) 2410 return (EFBIG); 2411 uio->uio_resid = maxfsz - uio->uio_offset; 2412 } 2413 2414 /* 2415 * This is kernel write (e.g. vnode_pager) or accounting 2416 * write, ignore limit. 2417 */ 2418 if (td == NULL || (td->td_pflags2 & TDP2_ACCT) != 0) 2419 return (0); 2420 2421 /* 2422 * Calculate file size limit. 2423 */ 2424 ktr_write = (td->td_pflags & TDP_INKTRACE) != 0; 2425 lim = __predict_false(ktr_write) ? td->td_ktr_io_lim : 2426 lim_cur(td, RLIMIT_FSIZE); 2427 2428 /* 2429 * Is the limit reached? 2430 */ 2431 if (__predict_true((uoff_t)uio->uio_offset + uio->uio_resid <= lim)) 2432 return (0); 2433 2434 /* 2435 * Prepared filesystems can handle writes truncated to the 2436 * file size limit. 2437 */ 2438 if (adj && (uoff_t)uio->uio_offset < lim) { 2439 uio->uio_resid = lim - (uoff_t)uio->uio_offset; 2440 return (0); 2441 } 2442 2443 if (!ktr_write || ktr_filesize_limit_signal) 2444 vn_send_sigxfsz(td->td_proc); 2445 return (EFBIG); 2446 } 2447 2448 /* 2449 * Helper for VOP_WRITE() implementations, the common code to 2450 * handle maximum supported file size on the filesystem, and 2451 * RLIMIT_FSIZE, except for special writes from accounting subsystem 2452 * and ktrace. 2453 * 2454 * For maximum file size (maxfsz argument): 2455 * - return EFBIG if uio_offset is beyond it 2456 * - otherwise, clamp uio_resid if write would extend file beyond maxfsz. 2457 * 2458 * For RLIMIT_FSIZE: 2459 * - return EFBIG and send SIGXFSZ if uio_offset is beyond the limit 2460 * - otherwise, clamp uio_resid if write would extend file beyond limit. 2461 * 2462 * If clamping occured, the adjustment for uio_resid is stored in 2463 * *resid_adj, to be re-applied by vn_rlimit_fsizex_res() on return 2464 * from the VOP. 2465 */ 2466 int 2467 vn_rlimit_fsizex(const struct vnode *vp, struct uio *uio, off_t maxfsz, 2468 ssize_t *resid_adj, struct thread *td) 2469 { 2470 ssize_t resid_orig; 2471 int error; 2472 bool adj; 2473 2474 resid_orig = uio->uio_resid; 2475 adj = resid_adj != NULL; 2476 error = vn_rlimit_fsizex1(vp, uio, maxfsz, adj, td); 2477 if (adj) 2478 *resid_adj = resid_orig - uio->uio_resid; 2479 return (error); 2480 } 2481 2482 void 2483 vn_rlimit_fsizex_res(struct uio *uio, ssize_t resid_adj) 2484 { 2485 uio->uio_resid += resid_adj; 2486 } 2487 2488 int 2489 vn_rlimit_fsize(const struct vnode *vp, const struct uio *uio, 2490 struct thread *td) 2491 { 2492 return (vn_rlimit_fsizex(vp, __DECONST(struct uio *, uio), 0, NULL, 2493 td)); 2494 } 2495 2496 int 2497 vn_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 2498 struct thread *td) 2499 { 2500 struct vnode *vp; 2501 2502 vp = fp->f_vnode; 2503 #ifdef AUDIT 2504 vn_lock(vp, LK_SHARED | LK_RETRY); 2505 AUDIT_ARG_VNODE1(vp); 2506 VOP_UNLOCK(vp); 2507 #endif 2508 return (setfmode(td, active_cred, vp, mode)); 2509 } 2510 2511 int 2512 vn_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 2513 struct thread *td) 2514 { 2515 struct vnode *vp; 2516 2517 vp = fp->f_vnode; 2518 #ifdef AUDIT 2519 vn_lock(vp, LK_SHARED | LK_RETRY); 2520 AUDIT_ARG_VNODE1(vp); 2521 VOP_UNLOCK(vp); 2522 #endif 2523 return (setfown(td, active_cred, vp, uid, gid)); 2524 } 2525 2526 /* 2527 * Remove pages in the range ["start", "end") from the vnode's VM object. If 2528 * "end" is 0, then the range extends to the end of the object. 2529 */ 2530 void 2531 vn_pages_remove(struct vnode *vp, vm_pindex_t start, vm_pindex_t end) 2532 { 2533 vm_object_t object; 2534 2535 if ((object = vp->v_object) == NULL) 2536 return; 2537 VM_OBJECT_WLOCK(object); 2538 vm_object_page_remove(object, start, end, 0); 2539 VM_OBJECT_WUNLOCK(object); 2540 } 2541 2542 /* 2543 * Like vn_pages_remove(), but skips invalid pages, which by definition are not 2544 * mapped into any process' address space. Filesystems may use this in 2545 * preference to vn_pages_remove() to avoid blocking on pages busied in 2546 * preparation for a VOP_GETPAGES. 2547 */ 2548 void 2549 vn_pages_remove_valid(struct vnode *vp, vm_pindex_t start, vm_pindex_t end) 2550 { 2551 vm_object_t object; 2552 2553 if ((object = vp->v_object) == NULL) 2554 return; 2555 VM_OBJECT_WLOCK(object); 2556 vm_object_page_remove(object, start, end, OBJPR_VALIDONLY); 2557 VM_OBJECT_WUNLOCK(object); 2558 } 2559 2560 int 2561 vn_bmap_seekhole_locked(struct vnode *vp, u_long cmd, off_t *off, 2562 struct ucred *cred) 2563 { 2564 vm_object_t obj; 2565 off_t size; 2566 daddr_t bn, bnp; 2567 uint64_t bsize; 2568 off_t noff; 2569 int error; 2570 2571 KASSERT(cmd == FIOSEEKHOLE || cmd == FIOSEEKDATA, 2572 ("%s: Wrong command %lu", __func__, cmd)); 2573 ASSERT_VOP_ELOCKED(vp, "vn_bmap_seekhole_locked"); 2574 2575 if (vp->v_type != VREG) { 2576 error = ENOTTY; 2577 goto out; 2578 } 2579 error = vn_getsize_locked(vp, &size, cred); 2580 if (error != 0) 2581 goto out; 2582 noff = *off; 2583 if (noff < 0 || noff >= size) { 2584 error = ENXIO; 2585 goto out; 2586 } 2587 2588 /* See the comment in ufs_bmap_seekdata(). */ 2589 obj = vp->v_object; 2590 if (obj != NULL) { 2591 VM_OBJECT_WLOCK(obj); 2592 vm_object_page_clean(obj, 0, 0, OBJPC_SYNC); 2593 VM_OBJECT_WUNLOCK(obj); 2594 } 2595 2596 bsize = vp->v_mount->mnt_stat.f_iosize; 2597 for (bn = noff / bsize; noff < size; bn++, noff += bsize - 2598 noff % bsize) { 2599 error = VOP_BMAP(vp, bn, NULL, &bnp, NULL, NULL); 2600 if (error == EOPNOTSUPP) { 2601 error = ENOTTY; 2602 goto out; 2603 } 2604 if ((bnp == -1 && cmd == FIOSEEKHOLE) || 2605 (bnp != -1 && cmd == FIOSEEKDATA)) { 2606 noff = bn * bsize; 2607 if (noff < *off) 2608 noff = *off; 2609 goto out; 2610 } 2611 } 2612 if (noff > size) 2613 noff = size; 2614 /* noff == size. There is an implicit hole at the end of file. */ 2615 if (cmd == FIOSEEKDATA) 2616 error = ENXIO; 2617 out: 2618 if (error == 0) 2619 *off = noff; 2620 return (error); 2621 } 2622 2623 int 2624 vn_bmap_seekhole(struct vnode *vp, u_long cmd, off_t *off, struct ucred *cred) 2625 { 2626 int error; 2627 2628 KASSERT(cmd == FIOSEEKHOLE || cmd == FIOSEEKDATA, 2629 ("%s: Wrong command %lu", __func__, cmd)); 2630 2631 if (vn_lock(vp, LK_EXCLUSIVE) != 0) 2632 return (EBADF); 2633 error = vn_bmap_seekhole_locked(vp, cmd, off, cred); 2634 VOP_UNLOCK(vp); 2635 return (error); 2636 } 2637 2638 int 2639 vn_seek(struct file *fp, off_t offset, int whence, struct thread *td) 2640 { 2641 struct ucred *cred; 2642 struct vnode *vp; 2643 off_t foffset, fsize, size; 2644 int error, noneg; 2645 2646 cred = td->td_ucred; 2647 vp = fp->f_vnode; 2648 foffset = foffset_lock(fp, 0); 2649 noneg = (vp->v_type != VCHR); 2650 error = 0; 2651 switch (whence) { 2652 case L_INCR: 2653 if (noneg && 2654 (foffset < 0 || 2655 (offset > 0 && foffset > OFF_MAX - offset))) { 2656 error = EOVERFLOW; 2657 break; 2658 } 2659 offset += foffset; 2660 break; 2661 case L_XTND: 2662 error = vn_getsize(vp, &fsize, cred); 2663 if (error != 0) 2664 break; 2665 2666 /* 2667 * If the file references a disk device, then fetch 2668 * the media size and use that to determine the ending 2669 * offset. 2670 */ 2671 if (fsize == 0 && vp->v_type == VCHR && 2672 fo_ioctl(fp, DIOCGMEDIASIZE, &size, cred, td) == 0) 2673 fsize = size; 2674 if (noneg && offset > 0 && fsize > OFF_MAX - offset) { 2675 error = EOVERFLOW; 2676 break; 2677 } 2678 offset += fsize; 2679 break; 2680 case L_SET: 2681 break; 2682 case SEEK_DATA: 2683 error = fo_ioctl(fp, FIOSEEKDATA, &offset, cred, td); 2684 if (error == ENOTTY) 2685 error = EINVAL; 2686 break; 2687 case SEEK_HOLE: 2688 error = fo_ioctl(fp, FIOSEEKHOLE, &offset, cred, td); 2689 if (error == ENOTTY) 2690 error = EINVAL; 2691 break; 2692 default: 2693 error = EINVAL; 2694 } 2695 if (error == 0 && noneg && offset < 0) 2696 error = EINVAL; 2697 if (error != 0) 2698 goto drop; 2699 VFS_KNOTE_UNLOCKED(vp, 0); 2700 td->td_uretoff.tdu_off = offset; 2701 drop: 2702 foffset_unlock(fp, offset, error != 0 ? FOF_NOUPDATE : 0); 2703 return (error); 2704 } 2705 2706 int 2707 vn_utimes_perm(struct vnode *vp, struct vattr *vap, struct ucred *cred, 2708 struct thread *td) 2709 { 2710 int error; 2711 2712 /* 2713 * Grant permission if the caller is the owner of the file, or 2714 * the super-user, or has ACL_WRITE_ATTRIBUTES permission on 2715 * on the file. If the time pointer is null, then write 2716 * permission on the file is also sufficient. 2717 * 2718 * From NFSv4.1, draft 21, 6.2.1.3.1, Discussion of Mask Attributes: 2719 * A user having ACL_WRITE_DATA or ACL_WRITE_ATTRIBUTES 2720 * will be allowed to set the times [..] to the current 2721 * server time. 2722 */ 2723 error = VOP_ACCESSX(vp, VWRITE_ATTRIBUTES, cred, td); 2724 if (error != 0 && (vap->va_vaflags & VA_UTIMES_NULL) != 0) 2725 error = VOP_ACCESS(vp, VWRITE, cred, td); 2726 return (error); 2727 } 2728 2729 int 2730 vn_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 2731 { 2732 struct vnode *vp; 2733 int error; 2734 2735 if (fp->f_type == DTYPE_FIFO) 2736 kif->kf_type = KF_TYPE_FIFO; 2737 else 2738 kif->kf_type = KF_TYPE_VNODE; 2739 vp = fp->f_vnode; 2740 vref(vp); 2741 FILEDESC_SUNLOCK(fdp); 2742 error = vn_fill_kinfo_vnode(vp, kif); 2743 vrele(vp); 2744 FILEDESC_SLOCK(fdp); 2745 return (error); 2746 } 2747 2748 static inline void 2749 vn_fill_junk(struct kinfo_file *kif) 2750 { 2751 size_t len, olen; 2752 2753 /* 2754 * Simulate vn_fullpath returning changing values for a given 2755 * vp during e.g. coredump. 2756 */ 2757 len = (arc4random() % (sizeof(kif->kf_path) - 2)) + 1; 2758 olen = strlen(kif->kf_path); 2759 if (len < olen) 2760 strcpy(&kif->kf_path[len - 1], "$"); 2761 else 2762 for (; olen < len; olen++) 2763 strcpy(&kif->kf_path[olen], "A"); 2764 } 2765 2766 int 2767 vn_fill_kinfo_vnode(struct vnode *vp, struct kinfo_file *kif) 2768 { 2769 struct vattr va; 2770 char *fullpath, *freepath; 2771 int error; 2772 2773 kif->kf_un.kf_file.kf_file_type = vntype_to_kinfo(vp->v_type); 2774 freepath = NULL; 2775 fullpath = "-"; 2776 error = vn_fullpath(vp, &fullpath, &freepath); 2777 if (error == 0) { 2778 strlcpy(kif->kf_path, fullpath, sizeof(kif->kf_path)); 2779 } 2780 if (freepath != NULL) 2781 free(freepath, M_TEMP); 2782 2783 KFAIL_POINT_CODE(DEBUG_FP, fill_kinfo_vnode__random_path, 2784 vn_fill_junk(kif); 2785 ); 2786 2787 /* 2788 * Retrieve vnode attributes. 2789 */ 2790 va.va_fsid = VNOVAL; 2791 va.va_rdev = NODEV; 2792 vn_lock(vp, LK_SHARED | LK_RETRY); 2793 error = VOP_GETATTR(vp, &va, curthread->td_ucred); 2794 VOP_UNLOCK(vp); 2795 if (error != 0) 2796 return (error); 2797 if (va.va_fsid != VNOVAL) 2798 kif->kf_un.kf_file.kf_file_fsid = va.va_fsid; 2799 else 2800 kif->kf_un.kf_file.kf_file_fsid = 2801 vp->v_mount->mnt_stat.f_fsid.val[0]; 2802 kif->kf_un.kf_file.kf_file_fsid_freebsd11 = 2803 kif->kf_un.kf_file.kf_file_fsid; /* truncate */ 2804 kif->kf_un.kf_file.kf_file_fileid = va.va_fileid; 2805 kif->kf_un.kf_file.kf_file_mode = MAKEIMODE(va.va_type, va.va_mode); 2806 kif->kf_un.kf_file.kf_file_size = va.va_size; 2807 kif->kf_un.kf_file.kf_file_rdev = va.va_rdev; 2808 kif->kf_un.kf_file.kf_file_rdev_freebsd11 = 2809 kif->kf_un.kf_file.kf_file_rdev; /* truncate */ 2810 kif->kf_un.kf_file.kf_file_nlink = va.va_nlink; 2811 return (0); 2812 } 2813 2814 int 2815 vn_mmap(struct file *fp, vm_map_t map, vm_offset_t *addr, vm_size_t size, 2816 vm_prot_t prot, vm_prot_t cap_maxprot, int flags, vm_ooffset_t foff, 2817 struct thread *td) 2818 { 2819 #ifdef HWPMC_HOOKS 2820 struct pmckern_map_in pkm; 2821 #endif 2822 struct mount *mp; 2823 struct vnode *vp; 2824 vm_object_t object; 2825 vm_prot_t maxprot; 2826 boolean_t writecounted; 2827 int error; 2828 2829 #if defined(COMPAT_FREEBSD7) || defined(COMPAT_FREEBSD6) || \ 2830 defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4) 2831 /* 2832 * POSIX shared-memory objects are defined to have 2833 * kernel persistence, and are not defined to support 2834 * read(2)/write(2) -- or even open(2). Thus, we can 2835 * use MAP_ASYNC to trade on-disk coherence for speed. 2836 * The shm_open(3) library routine turns on the FPOSIXSHM 2837 * flag to request this behavior. 2838 */ 2839 if ((fp->f_flag & FPOSIXSHM) != 0) 2840 flags |= MAP_NOSYNC; 2841 #endif 2842 vp = fp->f_vnode; 2843 2844 /* 2845 * Ensure that file and memory protections are 2846 * compatible. Note that we only worry about 2847 * writability if mapping is shared; in this case, 2848 * current and max prot are dictated by the open file. 2849 * XXX use the vnode instead? Problem is: what 2850 * credentials do we use for determination? What if 2851 * proc does a setuid? 2852 */ 2853 mp = vp->v_mount; 2854 if (mp != NULL && (mp->mnt_flag & MNT_NOEXEC) != 0) { 2855 maxprot = VM_PROT_NONE; 2856 if ((prot & VM_PROT_EXECUTE) != 0) 2857 return (EACCES); 2858 } else 2859 maxprot = VM_PROT_EXECUTE; 2860 if ((fp->f_flag & FREAD) != 0) 2861 maxprot |= VM_PROT_READ; 2862 else if ((prot & VM_PROT_READ) != 0) 2863 return (EACCES); 2864 2865 /* 2866 * If we are sharing potential changes via MAP_SHARED and we 2867 * are trying to get write permission although we opened it 2868 * without asking for it, bail out. 2869 */ 2870 if ((flags & MAP_SHARED) != 0) { 2871 if ((fp->f_flag & FWRITE) != 0) 2872 maxprot |= VM_PROT_WRITE; 2873 else if ((prot & VM_PROT_WRITE) != 0) 2874 return (EACCES); 2875 } else { 2876 maxprot |= VM_PROT_WRITE; 2877 cap_maxprot |= VM_PROT_WRITE; 2878 } 2879 maxprot &= cap_maxprot; 2880 2881 /* 2882 * For regular files and shared memory, POSIX requires that 2883 * the value of foff be a legitimate offset within the data 2884 * object. In particular, negative offsets are invalid. 2885 * Blocking negative offsets and overflows here avoids 2886 * possible wraparound or user-level access into reserved 2887 * ranges of the data object later. In contrast, POSIX does 2888 * not dictate how offsets are used by device drivers, so in 2889 * the case of a device mapping a negative offset is passed 2890 * on. 2891 */ 2892 if ( 2893 #ifdef _LP64 2894 size > OFF_MAX || 2895 #endif 2896 foff > OFF_MAX - size) 2897 return (EINVAL); 2898 2899 writecounted = FALSE; 2900 error = vm_mmap_vnode(td, size, prot, &maxprot, &flags, vp, 2901 &foff, &object, &writecounted); 2902 if (error != 0) 2903 return (error); 2904 error = vm_mmap_object(map, addr, size, prot, maxprot, flags, object, 2905 foff, writecounted, td); 2906 if (error != 0) { 2907 /* 2908 * If this mapping was accounted for in the vnode's 2909 * writecount, then undo that now. 2910 */ 2911 if (writecounted) 2912 vm_pager_release_writecount(object, 0, size); 2913 vm_object_deallocate(object); 2914 } 2915 #ifdef HWPMC_HOOKS 2916 /* Inform hwpmc(4) if an executable is being mapped. */ 2917 if (PMC_HOOK_INSTALLED(PMC_FN_MMAP)) { 2918 if ((prot & VM_PROT_EXECUTE) != 0 && error == 0) { 2919 pkm.pm_file = vp; 2920 pkm.pm_address = (uintptr_t) *addr; 2921 PMC_CALL_HOOK_UNLOCKED(td, PMC_FN_MMAP, (void *) &pkm); 2922 } 2923 } 2924 #endif 2925 return (error); 2926 } 2927 2928 void 2929 vn_fsid(struct vnode *vp, struct vattr *va) 2930 { 2931 fsid_t *f; 2932 2933 f = &vp->v_mount->mnt_stat.f_fsid; 2934 va->va_fsid = (uint32_t)f->val[1]; 2935 va->va_fsid <<= sizeof(f->val[1]) * NBBY; 2936 va->va_fsid += (uint32_t)f->val[0]; 2937 } 2938 2939 int 2940 vn_fsync_buf(struct vnode *vp, int waitfor) 2941 { 2942 struct buf *bp, *nbp; 2943 struct bufobj *bo; 2944 struct mount *mp; 2945 int error, maxretry; 2946 2947 error = 0; 2948 maxretry = 10000; /* large, arbitrarily chosen */ 2949 mp = NULL; 2950 if (vp->v_type == VCHR) { 2951 VI_LOCK(vp); 2952 mp = vp->v_rdev->si_mountpt; 2953 VI_UNLOCK(vp); 2954 } 2955 bo = &vp->v_bufobj; 2956 BO_LOCK(bo); 2957 loop1: 2958 /* 2959 * MARK/SCAN initialization to avoid infinite loops. 2960 */ 2961 TAILQ_FOREACH(bp, &bo->bo_dirty.bv_hd, b_bobufs) { 2962 bp->b_vflags &= ~BV_SCANNED; 2963 bp->b_error = 0; 2964 } 2965 2966 /* 2967 * Flush all dirty buffers associated with a vnode. 2968 */ 2969 loop2: 2970 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 2971 if ((bp->b_vflags & BV_SCANNED) != 0) 2972 continue; 2973 bp->b_vflags |= BV_SCANNED; 2974 if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT, NULL)) { 2975 if (waitfor != MNT_WAIT) 2976 continue; 2977 if (BUF_LOCK(bp, 2978 LK_EXCLUSIVE | LK_INTERLOCK | LK_SLEEPFAIL, 2979 BO_LOCKPTR(bo)) != 0) { 2980 BO_LOCK(bo); 2981 goto loop1; 2982 } 2983 BO_LOCK(bo); 2984 } 2985 BO_UNLOCK(bo); 2986 KASSERT(bp->b_bufobj == bo, 2987 ("bp %p wrong b_bufobj %p should be %p", 2988 bp, bp->b_bufobj, bo)); 2989 if ((bp->b_flags & B_DELWRI) == 0) 2990 panic("fsync: not dirty"); 2991 if ((vp->v_object != NULL) && (bp->b_flags & B_CLUSTEROK)) { 2992 vfs_bio_awrite(bp); 2993 } else { 2994 bremfree(bp); 2995 bawrite(bp); 2996 } 2997 if (maxretry < 1000) 2998 pause("dirty", hz < 1000 ? 1 : hz / 1000); 2999 BO_LOCK(bo); 3000 goto loop2; 3001 } 3002 3003 /* 3004 * If synchronous the caller expects us to completely resolve all 3005 * dirty buffers in the system. Wait for in-progress I/O to 3006 * complete (which could include background bitmap writes), then 3007 * retry if dirty blocks still exist. 3008 */ 3009 if (waitfor == MNT_WAIT) { 3010 bufobj_wwait(bo, 0, 0); 3011 if (bo->bo_dirty.bv_cnt > 0) { 3012 /* 3013 * If we are unable to write any of these buffers 3014 * then we fail now rather than trying endlessly 3015 * to write them out. 3016 */ 3017 TAILQ_FOREACH(bp, &bo->bo_dirty.bv_hd, b_bobufs) 3018 if ((error = bp->b_error) != 0) 3019 break; 3020 if ((mp != NULL && mp->mnt_secondary_writes > 0) || 3021 (error == 0 && --maxretry >= 0)) 3022 goto loop1; 3023 if (error == 0) 3024 error = EAGAIN; 3025 } 3026 } 3027 BO_UNLOCK(bo); 3028 if (error != 0) 3029 vn_printf(vp, "fsync: giving up on dirty (error = %d) ", error); 3030 3031 return (error); 3032 } 3033 3034 /* 3035 * Copies a byte range from invp to outvp. Calls VOP_COPY_FILE_RANGE() 3036 * or vn_generic_copy_file_range() after rangelocking the byte ranges, 3037 * to do the actual copy. 3038 * vn_generic_copy_file_range() is factored out, so it can be called 3039 * from a VOP_COPY_FILE_RANGE() call as well, but handles vnodes from 3040 * different file systems. 3041 */ 3042 int 3043 vn_copy_file_range(struct vnode *invp, off_t *inoffp, struct vnode *outvp, 3044 off_t *outoffp, size_t *lenp, unsigned int flags, struct ucred *incred, 3045 struct ucred *outcred, struct thread *fsize_td) 3046 { 3047 int error; 3048 size_t len; 3049 uint64_t uval; 3050 3051 len = *lenp; 3052 *lenp = 0; /* For error returns. */ 3053 error = 0; 3054 3055 /* Do some sanity checks on the arguments. */ 3056 if (invp->v_type == VDIR || outvp->v_type == VDIR) 3057 error = EISDIR; 3058 else if (*inoffp < 0 || *outoffp < 0 || 3059 invp->v_type != VREG || outvp->v_type != VREG) 3060 error = EINVAL; 3061 if (error != 0) 3062 goto out; 3063 3064 /* Ensure offset + len does not wrap around. */ 3065 uval = *inoffp; 3066 uval += len; 3067 if (uval > INT64_MAX) 3068 len = INT64_MAX - *inoffp; 3069 uval = *outoffp; 3070 uval += len; 3071 if (uval > INT64_MAX) 3072 len = INT64_MAX - *outoffp; 3073 if (len == 0) 3074 goto out; 3075 3076 /* 3077 * If the two vnode are for the same file system, call 3078 * VOP_COPY_FILE_RANGE(), otherwise call vn_generic_copy_file_range() 3079 * which can handle copies across multiple file systems. 3080 */ 3081 *lenp = len; 3082 if (invp->v_mount == outvp->v_mount) 3083 error = VOP_COPY_FILE_RANGE(invp, inoffp, outvp, outoffp, 3084 lenp, flags, incred, outcred, fsize_td); 3085 else 3086 error = vn_generic_copy_file_range(invp, inoffp, outvp, 3087 outoffp, lenp, flags, incred, outcred, fsize_td); 3088 out: 3089 return (error); 3090 } 3091 3092 /* 3093 * Test len bytes of data starting at dat for all bytes == 0. 3094 * Return true if all bytes are zero, false otherwise. 3095 * Expects dat to be well aligned. 3096 */ 3097 static bool 3098 mem_iszero(void *dat, int len) 3099 { 3100 int i; 3101 const u_int *p; 3102 const char *cp; 3103 3104 for (p = dat; len > 0; len -= sizeof(*p), p++) { 3105 if (len >= sizeof(*p)) { 3106 if (*p != 0) 3107 return (false); 3108 } else { 3109 cp = (const char *)p; 3110 for (i = 0; i < len; i++, cp++) 3111 if (*cp != '\0') 3112 return (false); 3113 } 3114 } 3115 return (true); 3116 } 3117 3118 /* 3119 * Look for a hole in the output file and, if found, adjust *outoffp 3120 * and *xferp to skip past the hole. 3121 * *xferp is the entire hole length to be written and xfer2 is how many bytes 3122 * to be written as 0's upon return. 3123 */ 3124 static off_t 3125 vn_skip_hole(struct vnode *outvp, off_t xfer2, off_t *outoffp, off_t *xferp, 3126 off_t *dataoffp, off_t *holeoffp, struct ucred *cred) 3127 { 3128 int error; 3129 off_t delta; 3130 3131 if (*holeoffp == 0 || *holeoffp <= *outoffp) { 3132 *dataoffp = *outoffp; 3133 error = VOP_IOCTL(outvp, FIOSEEKDATA, dataoffp, 0, cred, 3134 curthread); 3135 if (error == 0) { 3136 *holeoffp = *dataoffp; 3137 error = VOP_IOCTL(outvp, FIOSEEKHOLE, holeoffp, 0, cred, 3138 curthread); 3139 } 3140 if (error != 0 || *holeoffp == *dataoffp) { 3141 /* 3142 * Since outvp is unlocked, it may be possible for 3143 * another thread to do a truncate(), lseek(), write() 3144 * creating a hole at startoff between the above 3145 * VOP_IOCTL() calls, if the other thread does not do 3146 * rangelocking. 3147 * If that happens, *holeoffp == *dataoffp and finding 3148 * the hole has failed, so disable vn_skip_hole(). 3149 */ 3150 *holeoffp = -1; /* Disable use of vn_skip_hole(). */ 3151 return (xfer2); 3152 } 3153 KASSERT(*dataoffp >= *outoffp, 3154 ("vn_skip_hole: dataoff=%jd < outoff=%jd", 3155 (intmax_t)*dataoffp, (intmax_t)*outoffp)); 3156 KASSERT(*holeoffp > *dataoffp, 3157 ("vn_skip_hole: holeoff=%jd <= dataoff=%jd", 3158 (intmax_t)*holeoffp, (intmax_t)*dataoffp)); 3159 } 3160 3161 /* 3162 * If there is a hole before the data starts, advance *outoffp and 3163 * *xferp past the hole. 3164 */ 3165 if (*dataoffp > *outoffp) { 3166 delta = *dataoffp - *outoffp; 3167 if (delta >= *xferp) { 3168 /* Entire *xferp is a hole. */ 3169 *outoffp += *xferp; 3170 *xferp = 0; 3171 return (0); 3172 } 3173 *xferp -= delta; 3174 *outoffp += delta; 3175 xfer2 = MIN(xfer2, *xferp); 3176 } 3177 3178 /* 3179 * If a hole starts before the end of this xfer2, reduce this xfer2 so 3180 * that the write ends at the start of the hole. 3181 * *holeoffp should always be greater than *outoffp, but for the 3182 * non-INVARIANTS case, check this to make sure xfer2 remains a sane 3183 * value. 3184 */ 3185 if (*holeoffp > *outoffp && *holeoffp < *outoffp + xfer2) 3186 xfer2 = *holeoffp - *outoffp; 3187 return (xfer2); 3188 } 3189 3190 /* 3191 * Write an xfer sized chunk to outvp in blksize blocks from dat. 3192 * dat is a maximum of blksize in length and can be written repeatedly in 3193 * the chunk. 3194 * If growfile == true, just grow the file via vn_truncate_locked() instead 3195 * of doing actual writes. 3196 * If checkhole == true, a hole is being punched, so skip over any hole 3197 * already in the output file. 3198 */ 3199 static int 3200 vn_write_outvp(struct vnode *outvp, char *dat, off_t outoff, off_t xfer, 3201 u_long blksize, bool growfile, bool checkhole, struct ucred *cred) 3202 { 3203 struct mount *mp; 3204 off_t dataoff, holeoff, xfer2; 3205 int error; 3206 3207 /* 3208 * Loop around doing writes of blksize until write has been completed. 3209 * Lock/unlock on each loop iteration so that a bwillwrite() can be 3210 * done for each iteration, since the xfer argument can be very 3211 * large if there is a large hole to punch in the output file. 3212 */ 3213 error = 0; 3214 holeoff = 0; 3215 do { 3216 xfer2 = MIN(xfer, blksize); 3217 if (checkhole) { 3218 /* 3219 * Punching a hole. Skip writing if there is 3220 * already a hole in the output file. 3221 */ 3222 xfer2 = vn_skip_hole(outvp, xfer2, &outoff, &xfer, 3223 &dataoff, &holeoff, cred); 3224 if (xfer == 0) 3225 break; 3226 if (holeoff < 0) 3227 checkhole = false; 3228 KASSERT(xfer2 > 0, ("vn_write_outvp: xfer2=%jd", 3229 (intmax_t)xfer2)); 3230 } 3231 bwillwrite(); 3232 mp = NULL; 3233 error = vn_start_write(outvp, &mp, V_WAIT); 3234 if (error != 0) 3235 break; 3236 if (growfile) { 3237 error = vn_lock(outvp, LK_EXCLUSIVE); 3238 if (error == 0) { 3239 error = vn_truncate_locked(outvp, outoff + xfer, 3240 false, cred); 3241 VOP_UNLOCK(outvp); 3242 } 3243 } else { 3244 error = vn_lock(outvp, vn_lktype_write(mp, outvp)); 3245 if (error == 0) { 3246 error = vn_rdwr(UIO_WRITE, outvp, dat, xfer2, 3247 outoff, UIO_SYSSPACE, IO_NODELOCKED, 3248 curthread->td_ucred, cred, NULL, curthread); 3249 outoff += xfer2; 3250 xfer -= xfer2; 3251 VOP_UNLOCK(outvp); 3252 } 3253 } 3254 if (mp != NULL) 3255 vn_finished_write(mp); 3256 } while (!growfile && xfer > 0 && error == 0); 3257 return (error); 3258 } 3259 3260 /* 3261 * Copy a byte range of one file to another. This function can handle the 3262 * case where invp and outvp are on different file systems. 3263 * It can also be called by a VOP_COPY_FILE_RANGE() to do the work, if there 3264 * is no better file system specific way to do it. 3265 */ 3266 int 3267 vn_generic_copy_file_range(struct vnode *invp, off_t *inoffp, 3268 struct vnode *outvp, off_t *outoffp, size_t *lenp, unsigned int flags, 3269 struct ucred *incred, struct ucred *outcred, struct thread *fsize_td) 3270 { 3271 struct mount *mp; 3272 off_t startoff, endoff, xfer, xfer2; 3273 u_long blksize; 3274 int error, interrupted; 3275 bool cantseek, readzeros, eof, lastblock, holetoeof; 3276 ssize_t aresid, r = 0; 3277 size_t copylen, len, savlen; 3278 off_t insize, outsize; 3279 char *dat; 3280 long holein, holeout; 3281 struct timespec curts, endts; 3282 3283 holein = holeout = 0; 3284 savlen = len = *lenp; 3285 error = 0; 3286 interrupted = 0; 3287 dat = NULL; 3288 3289 error = vn_lock(invp, LK_SHARED); 3290 if (error != 0) 3291 goto out; 3292 if (VOP_PATHCONF(invp, _PC_MIN_HOLE_SIZE, &holein) != 0) 3293 holein = 0; 3294 if (holein > 0) 3295 error = vn_getsize_locked(invp, &insize, incred); 3296 VOP_UNLOCK(invp); 3297 if (error != 0) 3298 goto out; 3299 3300 mp = NULL; 3301 error = vn_start_write(outvp, &mp, V_WAIT); 3302 if (error == 0) 3303 error = vn_lock(outvp, LK_EXCLUSIVE); 3304 if (error == 0) { 3305 /* 3306 * If fsize_td != NULL, do a vn_rlimit_fsizex() call, 3307 * now that outvp is locked. 3308 */ 3309 if (fsize_td != NULL) { 3310 struct uio io; 3311 3312 io.uio_offset = *outoffp; 3313 io.uio_resid = len; 3314 error = vn_rlimit_fsizex(outvp, &io, 0, &r, fsize_td); 3315 len = savlen = io.uio_resid; 3316 /* 3317 * No need to call vn_rlimit_fsizex_res before return, 3318 * since the uio is local. 3319 */ 3320 } 3321 if (VOP_PATHCONF(outvp, _PC_MIN_HOLE_SIZE, &holeout) != 0) 3322 holeout = 0; 3323 /* 3324 * Holes that are past EOF do not need to be written as a block 3325 * of zero bytes. So, truncate the output file as far as 3326 * possible and then use size to decide if writing 0 3327 * bytes is necessary in the loop below. 3328 */ 3329 if (error == 0) 3330 error = vn_getsize_locked(outvp, &outsize, outcred); 3331 if (error == 0 && outsize > *outoffp && outsize <= *outoffp + len) { 3332 #ifdef MAC 3333 error = mac_vnode_check_write(curthread->td_ucred, 3334 outcred, outvp); 3335 if (error == 0) 3336 #endif 3337 error = vn_truncate_locked(outvp, *outoffp, 3338 false, outcred); 3339 if (error == 0) 3340 outsize = *outoffp; 3341 } 3342 VOP_UNLOCK(outvp); 3343 } 3344 if (mp != NULL) 3345 vn_finished_write(mp); 3346 if (error != 0) 3347 goto out; 3348 3349 if (holein == 0 && holeout > 0) { 3350 /* 3351 * For this special case, the input data will be scanned 3352 * for blocks of all 0 bytes. For these blocks, the 3353 * write can be skipped for the output file to create 3354 * an unallocated region. 3355 * Therefore, use the appropriate size for the output file. 3356 */ 3357 blksize = holeout; 3358 if (blksize <= 512) { 3359 /* 3360 * Use f_iosize, since ZFS reports a _PC_MIN_HOLE_SIZE 3361 * of 512, although it actually only creates 3362 * unallocated regions for blocks >= f_iosize. 3363 */ 3364 blksize = outvp->v_mount->mnt_stat.f_iosize; 3365 } 3366 } else { 3367 /* 3368 * Use the larger of the two f_iosize values. If they are 3369 * not the same size, one will normally be an exact multiple of 3370 * the other, since they are both likely to be a power of 2. 3371 */ 3372 blksize = MAX(invp->v_mount->mnt_stat.f_iosize, 3373 outvp->v_mount->mnt_stat.f_iosize); 3374 } 3375 3376 /* Clip to sane limits. */ 3377 if (blksize < 4096) 3378 blksize = 4096; 3379 else if (blksize > maxphys) 3380 blksize = maxphys; 3381 dat = malloc(blksize, M_TEMP, M_WAITOK); 3382 3383 /* 3384 * If VOP_IOCTL(FIOSEEKHOLE) works for invp, use it and FIOSEEKDATA 3385 * to find holes. Otherwise, just scan the read block for all 0s 3386 * in the inner loop where the data copying is done. 3387 * Note that some file systems such as NFSv3, NFSv4.0 and NFSv4.1 may 3388 * support holes on the server, but do not support FIOSEEKHOLE. 3389 * The kernel flag COPY_FILE_RANGE_TIMEO1SEC is used to indicate 3390 * that this function should return after 1second with a partial 3391 * completion. 3392 */ 3393 if ((flags & COPY_FILE_RANGE_TIMEO1SEC) != 0) { 3394 getnanouptime(&endts); 3395 endts.tv_sec++; 3396 } else 3397 timespecclear(&endts); 3398 holetoeof = eof = false; 3399 while (len > 0 && error == 0 && !eof && interrupted == 0) { 3400 endoff = 0; /* To shut up compilers. */ 3401 cantseek = true; 3402 startoff = *inoffp; 3403 copylen = len; 3404 3405 /* 3406 * Find the next data area. If there is just a hole to EOF, 3407 * FIOSEEKDATA should fail with ENXIO. 3408 * (I do not know if any file system will report a hole to 3409 * EOF via FIOSEEKHOLE, but I am pretty sure FIOSEEKDATA 3410 * will fail for those file systems.) 3411 * 3412 * For input files that don't support FIOSEEKDATA/FIOSEEKHOLE, 3413 * the code just falls through to the inner copy loop. 3414 */ 3415 error = EINVAL; 3416 if (holein > 0) { 3417 error = VOP_IOCTL(invp, FIOSEEKDATA, &startoff, 0, 3418 incred, curthread); 3419 if (error == ENXIO) { 3420 startoff = endoff = insize; 3421 eof = holetoeof = true; 3422 error = 0; 3423 } 3424 } 3425 if (error == 0 && !holetoeof) { 3426 endoff = startoff; 3427 error = VOP_IOCTL(invp, FIOSEEKHOLE, &endoff, 0, 3428 incred, curthread); 3429 /* 3430 * Since invp is unlocked, it may be possible for 3431 * another thread to do a truncate(), lseek(), write() 3432 * creating a hole at startoff between the above 3433 * VOP_IOCTL() calls, if the other thread does not do 3434 * rangelocking. 3435 * If that happens, startoff == endoff and finding 3436 * the hole has failed, so set an error. 3437 */ 3438 if (error == 0 && startoff == endoff) 3439 error = EINVAL; /* Any error. Reset to 0. */ 3440 } 3441 if (error == 0) { 3442 if (startoff > *inoffp) { 3443 /* Found hole before data block. */ 3444 xfer = MIN(startoff - *inoffp, len); 3445 if (*outoffp < outsize) { 3446 /* Must write 0s to punch hole. */ 3447 xfer2 = MIN(outsize - *outoffp, 3448 xfer); 3449 memset(dat, 0, MIN(xfer2, blksize)); 3450 error = vn_write_outvp(outvp, dat, 3451 *outoffp, xfer2, blksize, false, 3452 holeout > 0, outcred); 3453 } 3454 3455 if (error == 0 && *outoffp + xfer > 3456 outsize && (xfer == len || holetoeof)) { 3457 /* Grow output file (hole at end). */ 3458 error = vn_write_outvp(outvp, dat, 3459 *outoffp, xfer, blksize, true, 3460 false, outcred); 3461 } 3462 if (error == 0) { 3463 *inoffp += xfer; 3464 *outoffp += xfer; 3465 len -= xfer; 3466 if (len < savlen) { 3467 interrupted = sig_intr(); 3468 if (timespecisset(&endts) && 3469 interrupted == 0) { 3470 getnanouptime(&curts); 3471 if (timespeccmp(&curts, 3472 &endts, >=)) 3473 interrupted = 3474 EINTR; 3475 } 3476 } 3477 } 3478 } 3479 copylen = MIN(len, endoff - startoff); 3480 cantseek = false; 3481 } else { 3482 cantseek = true; 3483 startoff = *inoffp; 3484 copylen = len; 3485 error = 0; 3486 } 3487 3488 xfer = blksize; 3489 if (cantseek) { 3490 /* 3491 * Set first xfer to end at a block boundary, so that 3492 * holes are more likely detected in the loop below via 3493 * the for all bytes 0 method. 3494 */ 3495 xfer -= (*inoffp % blksize); 3496 } 3497 /* Loop copying the data block. */ 3498 while (copylen > 0 && error == 0 && !eof && interrupted == 0) { 3499 if (copylen < xfer) 3500 xfer = copylen; 3501 error = vn_lock(invp, LK_SHARED); 3502 if (error != 0) 3503 goto out; 3504 error = vn_rdwr(UIO_READ, invp, dat, xfer, 3505 startoff, UIO_SYSSPACE, IO_NODELOCKED, 3506 curthread->td_ucred, incred, &aresid, 3507 curthread); 3508 VOP_UNLOCK(invp); 3509 lastblock = false; 3510 if (error == 0 && aresid > 0) { 3511 /* Stop the copy at EOF on the input file. */ 3512 xfer -= aresid; 3513 eof = true; 3514 lastblock = true; 3515 } 3516 if (error == 0) { 3517 /* 3518 * Skip the write for holes past the initial EOF 3519 * of the output file, unless this is the last 3520 * write of the output file at EOF. 3521 */ 3522 readzeros = cantseek ? mem_iszero(dat, xfer) : 3523 false; 3524 if (xfer == len) 3525 lastblock = true; 3526 if (!cantseek || *outoffp < outsize || 3527 lastblock || !readzeros) 3528 error = vn_write_outvp(outvp, dat, 3529 *outoffp, xfer, blksize, 3530 readzeros && lastblock && 3531 *outoffp >= outsize, false, 3532 outcred); 3533 if (error == 0) { 3534 *inoffp += xfer; 3535 startoff += xfer; 3536 *outoffp += xfer; 3537 copylen -= xfer; 3538 len -= xfer; 3539 if (len < savlen) { 3540 interrupted = sig_intr(); 3541 if (timespecisset(&endts) && 3542 interrupted == 0) { 3543 getnanouptime(&curts); 3544 if (timespeccmp(&curts, 3545 &endts, >=)) 3546 interrupted = 3547 EINTR; 3548 } 3549 } 3550 } 3551 } 3552 xfer = blksize; 3553 } 3554 } 3555 out: 3556 *lenp = savlen - len; 3557 free(dat, M_TEMP); 3558 return (error); 3559 } 3560 3561 static int 3562 vn_fallocate(struct file *fp, off_t offset, off_t len, struct thread *td) 3563 { 3564 struct mount *mp; 3565 struct vnode *vp; 3566 off_t olen, ooffset; 3567 int error; 3568 #ifdef AUDIT 3569 int audited_vnode1 = 0; 3570 #endif 3571 3572 vp = fp->f_vnode; 3573 if (vp->v_type != VREG) 3574 return (ENODEV); 3575 3576 /* Allocating blocks may take a long time, so iterate. */ 3577 for (;;) { 3578 olen = len; 3579 ooffset = offset; 3580 3581 bwillwrite(); 3582 mp = NULL; 3583 error = vn_start_write(vp, &mp, V_WAIT | V_PCATCH); 3584 if (error != 0) 3585 break; 3586 error = vn_lock(vp, LK_EXCLUSIVE); 3587 if (error != 0) { 3588 vn_finished_write(mp); 3589 break; 3590 } 3591 #ifdef AUDIT 3592 if (!audited_vnode1) { 3593 AUDIT_ARG_VNODE1(vp); 3594 audited_vnode1 = 1; 3595 } 3596 #endif 3597 #ifdef MAC 3598 error = mac_vnode_check_write(td->td_ucred, fp->f_cred, vp); 3599 if (error == 0) 3600 #endif 3601 error = VOP_ALLOCATE(vp, &offset, &len, 0, 3602 td->td_ucred); 3603 VOP_UNLOCK(vp); 3604 vn_finished_write(mp); 3605 3606 if (olen + ooffset != offset + len) { 3607 panic("offset + len changed from %jx/%jx to %jx/%jx", 3608 ooffset, olen, offset, len); 3609 } 3610 if (error != 0 || len == 0) 3611 break; 3612 KASSERT(olen > len, ("Iteration did not make progress?")); 3613 maybe_yield(); 3614 } 3615 3616 return (error); 3617 } 3618 3619 static int 3620 vn_deallocate_impl(struct vnode *vp, off_t *offset, off_t *length, int flags, 3621 int ioflag, struct ucred *cred, struct ucred *active_cred, 3622 struct ucred *file_cred) 3623 { 3624 struct mount *mp; 3625 void *rl_cookie; 3626 off_t off, len; 3627 int error; 3628 #ifdef AUDIT 3629 bool audited_vnode1 = false; 3630 #endif 3631 3632 rl_cookie = NULL; 3633 error = 0; 3634 mp = NULL; 3635 off = *offset; 3636 len = *length; 3637 3638 if ((ioflag & (IO_NODELOCKED | IO_RANGELOCKED)) == 0) 3639 rl_cookie = vn_rangelock_wlock(vp, off, off + len); 3640 while (len > 0 && error == 0) { 3641 /* 3642 * Try to deallocate the longest range in one pass. 3643 * In case a pass takes too long to be executed, it returns 3644 * partial result. The residue will be proceeded in the next 3645 * pass. 3646 */ 3647 3648 if ((ioflag & IO_NODELOCKED) == 0) { 3649 bwillwrite(); 3650 if ((error = vn_start_write(vp, &mp, 3651 V_WAIT | V_PCATCH)) != 0) 3652 goto out; 3653 vn_lock(vp, vn_lktype_write(mp, vp) | LK_RETRY); 3654 } 3655 #ifdef AUDIT 3656 if (!audited_vnode1) { 3657 AUDIT_ARG_VNODE1(vp); 3658 audited_vnode1 = true; 3659 } 3660 #endif 3661 3662 #ifdef MAC 3663 if ((ioflag & IO_NOMACCHECK) == 0) 3664 error = mac_vnode_check_write(active_cred, file_cred, 3665 vp); 3666 #endif 3667 if (error == 0) 3668 error = VOP_DEALLOCATE(vp, &off, &len, flags, ioflag, 3669 cred); 3670 3671 if ((ioflag & IO_NODELOCKED) == 0) { 3672 VOP_UNLOCK(vp); 3673 if (mp != NULL) { 3674 vn_finished_write(mp); 3675 mp = NULL; 3676 } 3677 } 3678 if (error == 0 && len != 0) 3679 maybe_yield(); 3680 } 3681 out: 3682 if (rl_cookie != NULL) 3683 vn_rangelock_unlock(vp, rl_cookie); 3684 *offset = off; 3685 *length = len; 3686 return (error); 3687 } 3688 3689 /* 3690 * This function is supposed to be used in the situations where the deallocation 3691 * is not triggered by a user request. 3692 */ 3693 int 3694 vn_deallocate(struct vnode *vp, off_t *offset, off_t *length, int flags, 3695 int ioflag, struct ucred *active_cred, struct ucred *file_cred) 3696 { 3697 struct ucred *cred; 3698 3699 if (*offset < 0 || *length <= 0 || *length > OFF_MAX - *offset || 3700 flags != 0) 3701 return (EINVAL); 3702 if (vp->v_type != VREG) 3703 return (ENODEV); 3704 3705 cred = file_cred != NOCRED ? file_cred : active_cred; 3706 return (vn_deallocate_impl(vp, offset, length, flags, ioflag, cred, 3707 active_cred, file_cred)); 3708 } 3709 3710 static int 3711 vn_fspacectl(struct file *fp, int cmd, off_t *offset, off_t *length, int flags, 3712 struct ucred *active_cred, struct thread *td) 3713 { 3714 int error; 3715 struct vnode *vp; 3716 int ioflag; 3717 3718 KASSERT(cmd == SPACECTL_DEALLOC, ("vn_fspacectl: Invalid cmd")); 3719 KASSERT((flags & ~SPACECTL_F_SUPPORTED) == 0, 3720 ("vn_fspacectl: non-zero flags")); 3721 KASSERT(*offset >= 0 && *length > 0 && *length <= OFF_MAX - *offset, 3722 ("vn_fspacectl: offset/length overflow or underflow")); 3723 vp = fp->f_vnode; 3724 3725 if (vp->v_type != VREG) 3726 return (ENODEV); 3727 3728 ioflag = get_write_ioflag(fp); 3729 3730 switch (cmd) { 3731 case SPACECTL_DEALLOC: 3732 error = vn_deallocate_impl(vp, offset, length, flags, ioflag, 3733 active_cred, active_cred, fp->f_cred); 3734 break; 3735 default: 3736 panic("vn_fspacectl: unknown cmd %d", cmd); 3737 } 3738 3739 return (error); 3740 } 3741 3742 static u_long vn_lock_pair_pause_cnt; 3743 SYSCTL_ULONG(_debug, OID_AUTO, vn_lock_pair_pause, CTLFLAG_RD, 3744 &vn_lock_pair_pause_cnt, 0, 3745 "Count of vn_lock_pair deadlocks"); 3746 3747 u_int vn_lock_pair_pause_max; 3748 SYSCTL_UINT(_debug, OID_AUTO, vn_lock_pair_pause_max, CTLFLAG_RW, 3749 &vn_lock_pair_pause_max, 0, 3750 "Max ticks for vn_lock_pair deadlock avoidance sleep"); 3751 3752 static void 3753 vn_lock_pair_pause(const char *wmesg) 3754 { 3755 atomic_add_long(&vn_lock_pair_pause_cnt, 1); 3756 pause(wmesg, prng32_bounded(vn_lock_pair_pause_max)); 3757 } 3758 3759 /* 3760 * Lock pair of vnodes vp1, vp2, avoiding lock order reversal. 3761 * vp1_locked indicates whether vp1 is locked; if not, vp1 must be 3762 * unlocked. Same for vp2 and vp2_locked. One of the vnodes can be 3763 * NULL. 3764 * 3765 * The function returns with both vnodes exclusively or shared locked, 3766 * according to corresponding lkflags, and guarantees that it does not 3767 * create lock order reversal with other threads during its execution. 3768 * Both vnodes could be unlocked temporary (and reclaimed). 3769 * 3770 * If requesting shared locking, locked vnode lock must not be recursed. 3771 */ 3772 void 3773 vn_lock_pair(struct vnode *vp1, bool vp1_locked, int lkflags1, 3774 struct vnode *vp2, bool vp2_locked, int lkflags2) 3775 { 3776 int error; 3777 3778 MPASS(lkflags1 == LK_SHARED || lkflags1 == LK_EXCLUSIVE); 3779 MPASS(lkflags2 == LK_SHARED || lkflags2 == LK_EXCLUSIVE); 3780 3781 if (vp1 == NULL && vp2 == NULL) 3782 return; 3783 3784 if (vp1 != NULL) { 3785 if (lkflags1 == LK_SHARED && 3786 (vp1->v_vnlock->lock_object.lo_flags & LK_NOSHARE) != 0) 3787 lkflags1 = LK_EXCLUSIVE; 3788 if (vp1_locked && VOP_ISLOCKED(vp1) != LK_EXCLUSIVE) { 3789 ASSERT_VOP_LOCKED(vp1, "vp1"); 3790 if (lkflags1 == LK_EXCLUSIVE) { 3791 VOP_UNLOCK(vp1); 3792 ASSERT_VOP_UNLOCKED(vp1, 3793 "vp1 shared recursed"); 3794 vp1_locked = false; 3795 } 3796 } else if (!vp1_locked) 3797 ASSERT_VOP_UNLOCKED(vp1, "vp1"); 3798 } else { 3799 vp1_locked = true; 3800 } 3801 3802 if (vp2 != NULL) { 3803 if (lkflags2 == LK_SHARED && 3804 (vp2->v_vnlock->lock_object.lo_flags & LK_NOSHARE) != 0) 3805 lkflags2 = LK_EXCLUSIVE; 3806 if (vp2_locked && VOP_ISLOCKED(vp2) != LK_EXCLUSIVE) { 3807 ASSERT_VOP_LOCKED(vp2, "vp2"); 3808 if (lkflags2 == LK_EXCLUSIVE) { 3809 VOP_UNLOCK(vp2); 3810 ASSERT_VOP_UNLOCKED(vp2, 3811 "vp2 shared recursed"); 3812 vp2_locked = false; 3813 } 3814 } else if (!vp2_locked) 3815 ASSERT_VOP_UNLOCKED(vp2, "vp2"); 3816 } else { 3817 vp2_locked = true; 3818 } 3819 3820 if (!vp1_locked && !vp2_locked) { 3821 vn_lock(vp1, lkflags1 | LK_RETRY); 3822 vp1_locked = true; 3823 } 3824 3825 while (!vp1_locked || !vp2_locked) { 3826 if (vp1_locked && vp2 != NULL) { 3827 if (vp1 != NULL) { 3828 error = VOP_LOCK1(vp2, lkflags2 | LK_NOWAIT, 3829 __FILE__, __LINE__); 3830 if (error == 0) 3831 break; 3832 VOP_UNLOCK(vp1); 3833 vp1_locked = false; 3834 vn_lock_pair_pause("vlp1"); 3835 } 3836 vn_lock(vp2, lkflags2 | LK_RETRY); 3837 vp2_locked = true; 3838 } 3839 if (vp2_locked && vp1 != NULL) { 3840 if (vp2 != NULL) { 3841 error = VOP_LOCK1(vp1, lkflags1 | LK_NOWAIT, 3842 __FILE__, __LINE__); 3843 if (error == 0) 3844 break; 3845 VOP_UNLOCK(vp2); 3846 vp2_locked = false; 3847 vn_lock_pair_pause("vlp2"); 3848 } 3849 vn_lock(vp1, lkflags1 | LK_RETRY); 3850 vp1_locked = true; 3851 } 3852 } 3853 if (vp1 != NULL) { 3854 if (lkflags1 == LK_EXCLUSIVE) 3855 ASSERT_VOP_ELOCKED(vp1, "vp1 ret"); 3856 else 3857 ASSERT_VOP_LOCKED(vp1, "vp1 ret"); 3858 } 3859 if (vp2 != NULL) { 3860 if (lkflags2 == LK_EXCLUSIVE) 3861 ASSERT_VOP_ELOCKED(vp2, "vp2 ret"); 3862 else 3863 ASSERT_VOP_LOCKED(vp2, "vp2 ret"); 3864 } 3865 } 3866 3867 int 3868 vn_lktype_write(struct mount *mp, struct vnode *vp) 3869 { 3870 if (MNT_SHARED_WRITES(mp) || 3871 (mp == NULL && MNT_SHARED_WRITES(vp->v_mount))) 3872 return (LK_SHARED); 3873 return (LK_EXCLUSIVE); 3874 } 3875