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