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