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