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