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