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