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 43 #include <sys/cdefs.h> 44 #include "opt_hwpmc_hooks.h" 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 #include <sys/disk.h> 49 #include <sys/fail.h> 50 #include <sys/fcntl.h> 51 #include <sys/file.h> 52 #include <sys/kdb.h> 53 #include <sys/ktr.h> 54 #include <sys/stat.h> 55 #include <sys/priv.h> 56 #include <sys/proc.h> 57 #include <sys/limits.h> 58 #include <sys/lock.h> 59 #include <sys/mman.h> 60 #include <sys/mount.h> 61 #include <sys/mutex.h> 62 #include <sys/namei.h> 63 #include <sys/vnode.h> 64 #include <sys/dirent.h> 65 #include <sys/bio.h> 66 #include <sys/buf.h> 67 #include <sys/filio.h> 68 #include <sys/resourcevar.h> 69 #include <sys/rwlock.h> 70 #include <sys/prng.h> 71 #include <sys/sx.h> 72 #include <sys/sleepqueue.h> 73 #include <sys/sysctl.h> 74 #include <sys/ttycom.h> 75 #include <sys/conf.h> 76 #include <sys/syslog.h> 77 #include <sys/unistd.h> 78 #include <sys/user.h> 79 #include <sys/ktrace.h> 80 81 #include <security/audit/audit.h> 82 #include <security/mac/mac_framework.h> 83 84 #include <vm/vm.h> 85 #include <vm/vm_extern.h> 86 #include <vm/pmap.h> 87 #include <vm/vm_map.h> 88 #include <vm/vm_object.h> 89 #include <vm/vm_page.h> 90 #include <vm/vm_pager.h> 91 #include <vm/vnode_pager.h> 92 93 #ifdef HWPMC_HOOKS 94 #include <sys/pmckern.h> 95 #endif 96 97 static fo_rdwr_t vn_read; 98 static fo_rdwr_t vn_write; 99 static fo_rdwr_t vn_io_fault; 100 static fo_truncate_t vn_truncate; 101 static fo_ioctl_t vn_ioctl; 102 static fo_poll_t vn_poll; 103 static fo_kqfilter_t vn_kqfilter; 104 static fo_close_t vn_closefile; 105 static fo_mmap_t vn_mmap; 106 static fo_fallocate_t vn_fallocate; 107 static fo_fspacectl_t vn_fspacectl; 108 109 struct fileops vnops = { 110 .fo_read = vn_io_fault, 111 .fo_write = vn_io_fault, 112 .fo_truncate = vn_truncate, 113 .fo_ioctl = vn_ioctl, 114 .fo_poll = vn_poll, 115 .fo_kqfilter = vn_kqfilter, 116 .fo_stat = vn_statfile, 117 .fo_close = vn_closefile, 118 .fo_chmod = vn_chmod, 119 .fo_chown = vn_chown, 120 .fo_sendfile = vn_sendfile, 121 .fo_seek = vn_seek, 122 .fo_fill_kinfo = vn_fill_kinfo, 123 .fo_mmap = vn_mmap, 124 .fo_fallocate = vn_fallocate, 125 .fo_fspacectl = vn_fspacectl, 126 .fo_cmp = vn_cmp, 127 .fo_flags = DFLAG_PASSABLE | DFLAG_SEEKABLE 128 }; 129 130 const u_int io_hold_cnt = 16; 131 static int vn_io_fault_enable = 1; 132 SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_enable, CTLFLAG_RWTUN, 133 &vn_io_fault_enable, 0, "Enable vn_io_fault lock avoidance"); 134 static int vn_io_fault_prefault = 0; 135 SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_prefault, CTLFLAG_RWTUN, 136 &vn_io_fault_prefault, 0, "Enable vn_io_fault prefaulting"); 137 static int vn_io_pgcache_read_enable = 1; 138 SYSCTL_INT(_debug, OID_AUTO, vn_io_pgcache_read_enable, CTLFLAG_RWTUN, 139 &vn_io_pgcache_read_enable, 0, 140 "Enable copying from page cache for reads, avoiding fs"); 141 static u_long vn_io_faults_cnt; 142 SYSCTL_ULONG(_debug, OID_AUTO, vn_io_faults, CTLFLAG_RD, 143 &vn_io_faults_cnt, 0, "Count of vn_io_fault lock avoidance triggers"); 144 145 static int vfs_allow_read_dir = 0; 146 SYSCTL_INT(_security_bsd, OID_AUTO, allow_read_dir, CTLFLAG_RW, 147 &vfs_allow_read_dir, 0, 148 "Enable read(2) of directory by root for filesystems that support it"); 149 150 /* 151 * Returns true if vn_io_fault mode of handling the i/o request should 152 * be used. 153 */ 154 static bool 155 do_vn_io_fault(struct vnode *vp, struct uio *uio) 156 { 157 struct mount *mp; 158 159 return (uio->uio_segflg == UIO_USERSPACE && vp->v_type == VREG && 160 (mp = vp->v_mount) != NULL && 161 (mp->mnt_kern_flag & MNTK_NO_IOPF) != 0 && vn_io_fault_enable); 162 } 163 164 /* 165 * Structure used to pass arguments to vn_io_fault1(), to do either 166 * file- or vnode-based I/O calls. 167 */ 168 struct vn_io_fault_args { 169 enum { 170 VN_IO_FAULT_FOP, 171 VN_IO_FAULT_VOP 172 } kind; 173 struct ucred *cred; 174 int flags; 175 union { 176 struct fop_args_tag { 177 struct file *fp; 178 fo_rdwr_t *doio; 179 } fop_args; 180 struct vop_args_tag { 181 struct vnode *vp; 182 } vop_args; 183 } args; 184 }; 185 186 static int vn_io_fault1(struct vnode *vp, struct uio *uio, 187 struct vn_io_fault_args *args, struct thread *td); 188 189 int 190 vn_open(struct nameidata *ndp, int *flagp, int cmode, struct file *fp) 191 { 192 struct thread *td = curthread; 193 194 return (vn_open_cred(ndp, flagp, cmode, 0, td->td_ucred, fp)); 195 } 196 197 static uint64_t 198 open2nameif(int fmode, u_int vn_open_flags) 199 { 200 uint64_t res; 201 202 res = ISOPEN | LOCKLEAF; 203 if ((fmode & O_RESOLVE_BENEATH) != 0) 204 res |= RBENEATH; 205 if ((fmode & O_EMPTY_PATH) != 0) 206 res |= EMPTYPATH; 207 if ((fmode & FREAD) != 0) 208 res |= OPENREAD; 209 if ((fmode & FWRITE) != 0) 210 res |= OPENWRITE; 211 if ((vn_open_flags & VN_OPEN_NOAUDIT) == 0) 212 res |= AUDITVNODE1; 213 if ((vn_open_flags & VN_OPEN_NOCAPCHECK) != 0) 214 res |= NOCAPCHECK; 215 if ((vn_open_flags & VN_OPEN_WANTIOCTLCAPS) != 0) 216 res |= WANTIOCTLCAPS; 217 return (res); 218 } 219 220 /* 221 * Common code for vnode open operations via a name lookup. 222 * Lookup the vnode and invoke VOP_CREATE if needed. 223 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine. 224 * 225 * Note that this does NOT free nameidata for the successful case, 226 * due to the NDINIT being done elsewhere. 227 */ 228 int 229 vn_open_cred(struct nameidata *ndp, int *flagp, int cmode, u_int vn_open_flags, 230 struct ucred *cred, struct file *fp) 231 { 232 struct vnode *vp; 233 struct mount *mp; 234 struct vattr vat; 235 struct vattr *vap = &vat; 236 int fmode, error; 237 bool first_open; 238 239 restart: 240 first_open = false; 241 fmode = *flagp; 242 if ((fmode & (O_CREAT | O_EXCL | O_DIRECTORY)) == (O_CREAT | 243 O_EXCL | O_DIRECTORY) || 244 (fmode & (O_CREAT | O_EMPTY_PATH)) == (O_CREAT | O_EMPTY_PATH)) 245 return (EINVAL); 246 else if ((fmode & (O_CREAT | O_DIRECTORY)) == O_CREAT) { 247 ndp->ni_cnd.cn_nameiop = CREATE; 248 ndp->ni_cnd.cn_flags = open2nameif(fmode, vn_open_flags); 249 /* 250 * Set NOCACHE to avoid flushing the cache when 251 * rolling in many files at once. 252 * 253 * Set NC_KEEPPOSENTRY to keep positive entries if they already 254 * exist despite NOCACHE. 255 */ 256 ndp->ni_cnd.cn_flags |= LOCKPARENT | NOCACHE | NC_KEEPPOSENTRY; 257 if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0) 258 ndp->ni_cnd.cn_flags |= FOLLOW; 259 if ((vn_open_flags & VN_OPEN_INVFS) == 0) 260 bwillwrite(); 261 if ((error = namei(ndp)) != 0) 262 return (error); 263 if (ndp->ni_vp == NULL) { 264 VATTR_NULL(vap); 265 vap->va_type = VREG; 266 vap->va_mode = cmode; 267 if (fmode & O_EXCL) 268 vap->va_vaflags |= VA_EXCLUSIVE; 269 if (vn_start_write(ndp->ni_dvp, &mp, V_NOWAIT) != 0) { 270 NDFREE_PNBUF(ndp); 271 vput(ndp->ni_dvp); 272 if ((error = vn_start_write(NULL, &mp, 273 V_XSLEEP | V_PCATCH)) != 0) 274 return (error); 275 NDREINIT(ndp); 276 goto restart; 277 } 278 if ((vn_open_flags & VN_OPEN_NAMECACHE) != 0) 279 ndp->ni_cnd.cn_flags |= MAKEENTRY; 280 #ifdef MAC 281 error = mac_vnode_check_create(cred, ndp->ni_dvp, 282 &ndp->ni_cnd, vap); 283 if (error == 0) 284 #endif 285 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp, 286 &ndp->ni_cnd, vap); 287 vp = ndp->ni_vp; 288 if (error == 0 && (fmode & O_EXCL) != 0 && 289 (fmode & (O_EXLOCK | O_SHLOCK)) != 0) { 290 VI_LOCK(vp); 291 vp->v_iflag |= VI_FOPENING; 292 VI_UNLOCK(vp); 293 first_open = true; 294 } 295 VOP_VPUT_PAIR(ndp->ni_dvp, error == 0 ? &vp : NULL, 296 false); 297 vn_finished_write(mp); 298 if (error) { 299 NDFREE_PNBUF(ndp); 300 if (error == ERELOOKUP) { 301 NDREINIT(ndp); 302 goto restart; 303 } 304 return (error); 305 } 306 fmode &= ~O_TRUNC; 307 } else { 308 if (ndp->ni_dvp == ndp->ni_vp) 309 vrele(ndp->ni_dvp); 310 else 311 vput(ndp->ni_dvp); 312 ndp->ni_dvp = NULL; 313 vp = ndp->ni_vp; 314 if (fmode & O_EXCL) { 315 error = EEXIST; 316 goto bad; 317 } 318 if (vp->v_type == VDIR) { 319 error = EISDIR; 320 goto bad; 321 } 322 fmode &= ~O_CREAT; 323 } 324 } else { 325 ndp->ni_cnd.cn_nameiop = LOOKUP; 326 ndp->ni_cnd.cn_flags = open2nameif(fmode, vn_open_flags); 327 ndp->ni_cnd.cn_flags |= (fmode & O_NOFOLLOW) != 0 ? NOFOLLOW : 328 FOLLOW; 329 if ((fmode & FWRITE) == 0) 330 ndp->ni_cnd.cn_flags |= LOCKSHARED; 331 if ((error = namei(ndp)) != 0) 332 return (error); 333 vp = ndp->ni_vp; 334 } 335 error = vn_open_vnode(vp, fmode, cred, curthread, fp); 336 if (first_open) { 337 VI_LOCK(vp); 338 vp->v_iflag &= ~VI_FOPENING; 339 wakeup(vp); 340 VI_UNLOCK(vp); 341 } 342 if (error) 343 goto bad; 344 *flagp = fmode; 345 return (0); 346 bad: 347 NDFREE_PNBUF(ndp); 348 vput(vp); 349 *flagp = fmode; 350 ndp->ni_vp = NULL; 351 return (error); 352 } 353 354 static int 355 vn_open_vnode_advlock(struct vnode *vp, int fmode, struct file *fp) 356 { 357 struct flock lf; 358 int error, lock_flags, type; 359 360 ASSERT_VOP_LOCKED(vp, "vn_open_vnode_advlock"); 361 if ((fmode & (O_EXLOCK | O_SHLOCK)) == 0) 362 return (0); 363 KASSERT(fp != NULL, ("open with flock requires fp")); 364 if (fp->f_type != DTYPE_NONE && fp->f_type != DTYPE_VNODE) 365 return (EOPNOTSUPP); 366 367 lock_flags = VOP_ISLOCKED(vp); 368 VOP_UNLOCK(vp); 369 370 lf.l_whence = SEEK_SET; 371 lf.l_start = 0; 372 lf.l_len = 0; 373 lf.l_type = (fmode & O_EXLOCK) != 0 ? F_WRLCK : F_RDLCK; 374 type = F_FLOCK; 375 if ((fmode & FNONBLOCK) == 0) 376 type |= F_WAIT; 377 if ((fmode & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL)) 378 type |= F_FIRSTOPEN; 379 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, type); 380 if (error == 0) 381 fp->f_flag |= FHASLOCK; 382 383 vn_lock(vp, lock_flags | LK_RETRY); 384 return (error); 385 } 386 387 /* 388 * Common code for vnode open operations once a vnode is located. 389 * Check permissions, and call the VOP_OPEN routine. 390 */ 391 int 392 vn_open_vnode(struct vnode *vp, int fmode, struct ucred *cred, 393 struct thread *td, struct file *fp) 394 { 395 accmode_t accmode; 396 int error; 397 398 if (vp->v_type == VLNK) { 399 if ((fmode & O_PATH) == 0 || (fmode & FEXEC) != 0) 400 return (EMLINK); 401 } 402 if (vp->v_type != VDIR && fmode & O_DIRECTORY) 403 return (ENOTDIR); 404 405 accmode = 0; 406 if ((fmode & O_PATH) == 0) { 407 if (vp->v_type == VSOCK) 408 return (EOPNOTSUPP); 409 if ((fmode & (FWRITE | O_TRUNC)) != 0) { 410 if (vp->v_type == VDIR) 411 return (EISDIR); 412 accmode |= VWRITE; 413 } 414 if ((fmode & FREAD) != 0) 415 accmode |= VREAD; 416 if ((fmode & O_APPEND) && (fmode & FWRITE)) 417 accmode |= VAPPEND; 418 #ifdef MAC 419 if ((fmode & O_CREAT) != 0) 420 accmode |= VCREAT; 421 #endif 422 } 423 if ((fmode & FEXEC) != 0) 424 accmode |= VEXEC; 425 #ifdef MAC 426 if ((fmode & O_VERIFY) != 0) 427 accmode |= VVERIFY; 428 error = mac_vnode_check_open(cred, vp, accmode); 429 if (error != 0) 430 return (error); 431 432 accmode &= ~(VCREAT | VVERIFY); 433 #endif 434 if ((fmode & O_CREAT) == 0 && accmode != 0) { 435 error = VOP_ACCESS(vp, accmode, cred, td); 436 if (error != 0) 437 return (error); 438 } 439 if ((fmode & O_PATH) != 0) { 440 if (vp->v_type != VFIFO && vp->v_type != VSOCK && 441 VOP_ACCESS(vp, VREAD, cred, td) == 0) 442 fp->f_flag |= FKQALLOWED; 443 return (0); 444 } 445 446 if (vp->v_type == VFIFO && VOP_ISLOCKED(vp) != LK_EXCLUSIVE) 447 vn_lock(vp, LK_UPGRADE | LK_RETRY); 448 error = VOP_OPEN(vp, fmode, cred, td, fp); 449 if (error != 0) 450 return (error); 451 452 error = vn_open_vnode_advlock(vp, fmode, fp); 453 if (error == 0 && (fmode & FWRITE) != 0) { 454 error = VOP_ADD_WRITECOUNT(vp, 1); 455 if (error == 0) { 456 CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d", 457 __func__, vp, vp->v_writecount); 458 } 459 } 460 461 /* 462 * Error from advlock or VOP_ADD_WRITECOUNT() still requires 463 * calling VOP_CLOSE() to pair with earlier VOP_OPEN(). 464 */ 465 if (error != 0) { 466 if (fp != NULL) { 467 /* 468 * Arrange the call by having fdrop() to use 469 * vn_closefile(). This is to satisfy 470 * filesystems like devfs or tmpfs, which 471 * override fo_close(). 472 */ 473 fp->f_flag |= FOPENFAILED; 474 fp->f_vnode = vp; 475 if (fp->f_ops == &badfileops) { 476 fp->f_type = DTYPE_VNODE; 477 fp->f_ops = &vnops; 478 } 479 vref(vp); 480 } else { 481 /* 482 * If there is no fp, due to kernel-mode open, 483 * we can call VOP_CLOSE() now. 484 */ 485 if ((vp->v_type == VFIFO || 486 !MNT_EXTENDED_SHARED(vp->v_mount)) && 487 VOP_ISLOCKED(vp) != LK_EXCLUSIVE) 488 vn_lock(vp, LK_UPGRADE | LK_RETRY); 489 (void)VOP_CLOSE(vp, fmode & (FREAD | FWRITE | FEXEC), 490 cred, td); 491 } 492 } 493 494 ASSERT_VOP_LOCKED(vp, "vn_open_vnode"); 495 return (error); 496 497 } 498 499 /* 500 * Check for write permissions on the specified vnode. 501 * Prototype text segments cannot be written. 502 * It is racy. 503 */ 504 int 505 vn_writechk(struct vnode *vp) 506 { 507 508 ASSERT_VOP_LOCKED(vp, "vn_writechk"); 509 /* 510 * If there's shared text associated with 511 * the vnode, try to free it up once. If 512 * we fail, we can't allow writing. 513 */ 514 if (VOP_IS_TEXT(vp)) 515 return (ETXTBSY); 516 517 return (0); 518 } 519 520 /* 521 * Vnode close call 522 */ 523 static int 524 vn_close1(struct vnode *vp, int flags, struct ucred *file_cred, 525 struct thread *td, bool keep_ref) 526 { 527 struct mount *mp; 528 int error, lock_flags; 529 530 lock_flags = vp->v_type != VFIFO && MNT_EXTENDED_SHARED(vp->v_mount) ? 531 LK_SHARED : LK_EXCLUSIVE; 532 533 vn_start_write(vp, &mp, V_WAIT); 534 vn_lock(vp, lock_flags | LK_RETRY); 535 AUDIT_ARG_VNODE1(vp); 536 if ((flags & (FWRITE | FOPENFAILED)) == FWRITE) { 537 VOP_ADD_WRITECOUNT_CHECKED(vp, -1); 538 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d", 539 __func__, vp, vp->v_writecount); 540 } 541 error = VOP_CLOSE(vp, flags, file_cred, td); 542 if (keep_ref) 543 VOP_UNLOCK(vp); 544 else 545 vput(vp); 546 vn_finished_write(mp); 547 return (error); 548 } 549 550 int 551 vn_close(struct vnode *vp, int flags, struct ucred *file_cred, 552 struct thread *td) 553 { 554 555 return (vn_close1(vp, flags, file_cred, td, false)); 556 } 557 558 /* 559 * Heuristic to detect sequential operation. 560 */ 561 static int 562 sequential_heuristic(struct uio *uio, struct file *fp) 563 { 564 enum uio_rw rw; 565 566 ASSERT_VOP_LOCKED(fp->f_vnode, __func__); 567 568 rw = uio->uio_rw; 569 if (fp->f_flag & FRDAHEAD) 570 return (fp->f_seqcount[rw] << IO_SEQSHIFT); 571 572 /* 573 * Offset 0 is handled specially. open() sets f_seqcount to 1 so 574 * that the first I/O is normally considered to be slightly 575 * sequential. Seeking to offset 0 doesn't change sequentiality 576 * unless previous seeks have reduced f_seqcount to 0, in which 577 * case offset 0 is not special. 578 */ 579 if ((uio->uio_offset == 0 && fp->f_seqcount[rw] > 0) || 580 uio->uio_offset == fp->f_nextoff[rw]) { 581 /* 582 * f_seqcount is in units of fixed-size blocks so that it 583 * depends mainly on the amount of sequential I/O and not 584 * much on the number of sequential I/O's. The fixed size 585 * of 16384 is hard-coded here since it is (not quite) just 586 * a magic size that works well here. This size is more 587 * closely related to the best I/O size for real disks than 588 * to any block size used by software. 589 */ 590 if (uio->uio_resid >= IO_SEQMAX * 16384) 591 fp->f_seqcount[rw] = IO_SEQMAX; 592 else { 593 fp->f_seqcount[rw] += howmany(uio->uio_resid, 16384); 594 if (fp->f_seqcount[rw] > IO_SEQMAX) 595 fp->f_seqcount[rw] = IO_SEQMAX; 596 } 597 return (fp->f_seqcount[rw] << IO_SEQSHIFT); 598 } 599 600 /* Not sequential. Quickly draw-down sequentiality. */ 601 if (fp->f_seqcount[rw] > 1) 602 fp->f_seqcount[rw] = 1; 603 else 604 fp->f_seqcount[rw] = 0; 605 return (0); 606 } 607 608 /* 609 * Package up an I/O request on a vnode into a uio and do it. 610 */ 611 int 612 vn_rdwr(enum uio_rw rw, struct vnode *vp, void *base, int len, off_t offset, 613 enum uio_seg segflg, int ioflg, struct ucred *active_cred, 614 struct ucred *file_cred, ssize_t *aresid, struct thread *td) 615 { 616 struct uio auio; 617 struct iovec aiov; 618 struct mount *mp; 619 struct ucred *cred; 620 void *rl_cookie; 621 struct vn_io_fault_args args; 622 int error, lock_flags; 623 624 if (offset < 0 && vp->v_type != VCHR) 625 return (EINVAL); 626 auio.uio_iov = &aiov; 627 auio.uio_iovcnt = 1; 628 aiov.iov_base = base; 629 aiov.iov_len = len; 630 auio.uio_resid = len; 631 auio.uio_offset = offset; 632 auio.uio_segflg = segflg; 633 auio.uio_rw = rw; 634 auio.uio_td = td; 635 error = 0; 636 637 if ((ioflg & IO_NODELOCKED) == 0) { 638 if ((ioflg & IO_RANGELOCKED) == 0) { 639 if (rw == UIO_READ) { 640 rl_cookie = vn_rangelock_rlock(vp, offset, 641 offset + len); 642 } else if ((ioflg & IO_APPEND) != 0) { 643 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 644 } else { 645 rl_cookie = vn_rangelock_wlock(vp, offset, 646 offset + len); 647 } 648 } else 649 rl_cookie = NULL; 650 mp = NULL; 651 if (rw == UIO_WRITE) { 652 if (vp->v_type != VCHR && 653 (error = vn_start_write(vp, &mp, V_WAIT | V_PCATCH)) 654 != 0) 655 goto out; 656 lock_flags = vn_lktype_write(mp, vp); 657 } else 658 lock_flags = LK_SHARED; 659 vn_lock(vp, lock_flags | LK_RETRY); 660 } else 661 rl_cookie = NULL; 662 663 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 664 #ifdef MAC 665 if ((ioflg & IO_NOMACCHECK) == 0) { 666 if (rw == UIO_READ) 667 error = mac_vnode_check_read(active_cred, file_cred, 668 vp); 669 else 670 error = mac_vnode_check_write(active_cred, file_cred, 671 vp); 672 } 673 #endif 674 if (error == 0) { 675 if (file_cred != NULL) 676 cred = file_cred; 677 else 678 cred = active_cred; 679 if (do_vn_io_fault(vp, &auio)) { 680 args.kind = VN_IO_FAULT_VOP; 681 args.cred = cred; 682 args.flags = ioflg; 683 args.args.vop_args.vp = vp; 684 error = vn_io_fault1(vp, &auio, &args, td); 685 } else if (rw == UIO_READ) { 686 error = VOP_READ(vp, &auio, ioflg, cred); 687 } else /* if (rw == UIO_WRITE) */ { 688 error = VOP_WRITE(vp, &auio, ioflg, cred); 689 } 690 } 691 if (aresid) 692 *aresid = auio.uio_resid; 693 else 694 if (auio.uio_resid && error == 0) 695 error = EIO; 696 if ((ioflg & IO_NODELOCKED) == 0) { 697 VOP_UNLOCK(vp); 698 if (mp != NULL) 699 vn_finished_write(mp); 700 } 701 out: 702 if (rl_cookie != NULL) 703 vn_rangelock_unlock(vp, rl_cookie); 704 return (error); 705 } 706 707 /* 708 * Package up an I/O request on a vnode into a uio and do it. The I/O 709 * request is split up into smaller chunks and we try to avoid saturating 710 * the buffer cache while potentially holding a vnode locked, so we 711 * check bwillwrite() before calling vn_rdwr(). We also call kern_yield() 712 * to give other processes a chance to lock the vnode (either other processes 713 * core'ing the same binary, or unrelated processes scanning the directory). 714 */ 715 int 716 vn_rdwr_inchunks(enum uio_rw rw, struct vnode *vp, void *base, size_t len, 717 off_t offset, enum uio_seg segflg, int ioflg, struct ucred *active_cred, 718 struct ucred *file_cred, size_t *aresid, struct thread *td) 719 { 720 int error = 0; 721 ssize_t iaresid; 722 723 do { 724 int chunk; 725 726 /* 727 * Force `offset' to a multiple of MAXBSIZE except possibly 728 * for the first chunk, so that filesystems only need to 729 * write full blocks except possibly for the first and last 730 * chunks. 731 */ 732 chunk = MAXBSIZE - (uoff_t)offset % MAXBSIZE; 733 734 if (chunk > len) 735 chunk = len; 736 if (rw != UIO_READ && vp->v_type == VREG) 737 bwillwrite(); 738 iaresid = 0; 739 error = vn_rdwr(rw, vp, base, chunk, offset, segflg, 740 ioflg, active_cred, file_cred, &iaresid, td); 741 len -= chunk; /* aresid calc already includes length */ 742 if (error) 743 break; 744 offset += chunk; 745 base = (char *)base + chunk; 746 kern_yield(PRI_USER); 747 } while (len); 748 if (aresid) 749 *aresid = len + iaresid; 750 return (error); 751 } 752 753 #if OFF_MAX <= LONG_MAX 754 off_t 755 foffset_lock(struct file *fp, int flags) 756 { 757 volatile short *flagsp; 758 off_t res; 759 short state; 760 761 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed")); 762 763 if ((flags & FOF_NOLOCK) != 0) 764 return (atomic_load_long(&fp->f_offset)); 765 766 /* 767 * According to McKusick the vn lock was protecting f_offset here. 768 * It is now protected by the FOFFSET_LOCKED flag. 769 */ 770 flagsp = &fp->f_vnread_flags; 771 if (atomic_cmpset_acq_16(flagsp, 0, FOFFSET_LOCKED)) 772 return (atomic_load_long(&fp->f_offset)); 773 774 sleepq_lock(&fp->f_vnread_flags); 775 state = atomic_load_16(flagsp); 776 for (;;) { 777 if ((state & FOFFSET_LOCKED) == 0) { 778 if (!atomic_fcmpset_acq_16(flagsp, &state, 779 FOFFSET_LOCKED)) 780 continue; 781 break; 782 } 783 if ((state & FOFFSET_LOCK_WAITING) == 0) { 784 if (!atomic_fcmpset_acq_16(flagsp, &state, 785 state | FOFFSET_LOCK_WAITING)) 786 continue; 787 } 788 DROP_GIANT(); 789 sleepq_add(&fp->f_vnread_flags, NULL, "vofflock", 0, 0); 790 sleepq_wait(&fp->f_vnread_flags, PUSER -1); 791 PICKUP_GIANT(); 792 sleepq_lock(&fp->f_vnread_flags); 793 state = atomic_load_16(flagsp); 794 } 795 res = atomic_load_long(&fp->f_offset); 796 sleepq_release(&fp->f_vnread_flags); 797 return (res); 798 } 799 800 void 801 foffset_unlock(struct file *fp, off_t val, int flags) 802 { 803 volatile short *flagsp; 804 short state; 805 806 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed")); 807 808 if ((flags & FOF_NOUPDATE) == 0) 809 atomic_store_long(&fp->f_offset, val); 810 if ((flags & FOF_NEXTOFF_R) != 0) 811 fp->f_nextoff[UIO_READ] = val; 812 if ((flags & FOF_NEXTOFF_W) != 0) 813 fp->f_nextoff[UIO_WRITE] = val; 814 815 if ((flags & FOF_NOLOCK) != 0) 816 return; 817 818 flagsp = &fp->f_vnread_flags; 819 state = atomic_load_16(flagsp); 820 if ((state & FOFFSET_LOCK_WAITING) == 0 && 821 atomic_cmpset_rel_16(flagsp, state, 0)) 822 return; 823 824 sleepq_lock(&fp->f_vnread_flags); 825 MPASS((fp->f_vnread_flags & FOFFSET_LOCKED) != 0); 826 MPASS((fp->f_vnread_flags & FOFFSET_LOCK_WAITING) != 0); 827 fp->f_vnread_flags = 0; 828 sleepq_broadcast(&fp->f_vnread_flags, SLEEPQ_SLEEP, 0, 0); 829 sleepq_release(&fp->f_vnread_flags); 830 } 831 832 static off_t 833 foffset_read(struct file *fp) 834 { 835 836 return (atomic_load_long(&fp->f_offset)); 837 } 838 #else 839 off_t 840 foffset_lock(struct file *fp, int flags) 841 { 842 struct mtx *mtxp; 843 off_t res; 844 845 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed")); 846 847 mtxp = mtx_pool_find(mtxpool_sleep, fp); 848 mtx_lock(mtxp); 849 if ((flags & FOF_NOLOCK) == 0) { 850 while (fp->f_vnread_flags & FOFFSET_LOCKED) { 851 fp->f_vnread_flags |= FOFFSET_LOCK_WAITING; 852 msleep(&fp->f_vnread_flags, mtxp, PUSER -1, 853 "vofflock", 0); 854 } 855 fp->f_vnread_flags |= FOFFSET_LOCKED; 856 } 857 res = fp->f_offset; 858 mtx_unlock(mtxp); 859 return (res); 860 } 861 862 void 863 foffset_unlock(struct file *fp, off_t val, int flags) 864 { 865 struct mtx *mtxp; 866 867 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed")); 868 869 mtxp = mtx_pool_find(mtxpool_sleep, fp); 870 mtx_lock(mtxp); 871 if ((flags & FOF_NOUPDATE) == 0) 872 fp->f_offset = val; 873 if ((flags & FOF_NEXTOFF_R) != 0) 874 fp->f_nextoff[UIO_READ] = val; 875 if ((flags & FOF_NEXTOFF_W) != 0) 876 fp->f_nextoff[UIO_WRITE] = val; 877 if ((flags & FOF_NOLOCK) == 0) { 878 KASSERT((fp->f_vnread_flags & FOFFSET_LOCKED) != 0, 879 ("Lost FOFFSET_LOCKED")); 880 if (fp->f_vnread_flags & FOFFSET_LOCK_WAITING) 881 wakeup(&fp->f_vnread_flags); 882 fp->f_vnread_flags = 0; 883 } 884 mtx_unlock(mtxp); 885 } 886 887 static off_t 888 foffset_read(struct file *fp) 889 { 890 891 return (foffset_lock(fp, FOF_NOLOCK)); 892 } 893 #endif 894 895 void 896 foffset_lock_uio(struct file *fp, struct uio *uio, int flags) 897 { 898 899 if ((flags & FOF_OFFSET) == 0) 900 uio->uio_offset = foffset_lock(fp, flags); 901 } 902 903 void 904 foffset_unlock_uio(struct file *fp, struct uio *uio, int flags) 905 { 906 907 if ((flags & FOF_OFFSET) == 0) 908 foffset_unlock(fp, uio->uio_offset, flags); 909 } 910 911 static int 912 get_advice(struct file *fp, struct uio *uio) 913 { 914 struct mtx *mtxp; 915 int ret; 916 917 ret = POSIX_FADV_NORMAL; 918 if (fp->f_advice == NULL || fp->f_vnode->v_type != VREG) 919 return (ret); 920 921 mtxp = mtx_pool_find(mtxpool_sleep, fp); 922 mtx_lock(mtxp); 923 if (fp->f_advice != NULL && 924 uio->uio_offset >= fp->f_advice->fa_start && 925 uio->uio_offset + uio->uio_resid <= fp->f_advice->fa_end) 926 ret = fp->f_advice->fa_advice; 927 mtx_unlock(mtxp); 928 return (ret); 929 } 930 931 static int 932 get_write_ioflag(struct file *fp) 933 { 934 int ioflag; 935 struct mount *mp; 936 struct vnode *vp; 937 938 ioflag = 0; 939 vp = fp->f_vnode; 940 mp = atomic_load_ptr(&vp->v_mount); 941 942 if ((fp->f_flag & O_DIRECT) != 0) 943 ioflag |= IO_DIRECT; 944 945 if ((fp->f_flag & O_FSYNC) != 0 || 946 (mp != NULL && (mp->mnt_flag & MNT_SYNCHRONOUS) != 0)) 947 ioflag |= IO_SYNC; 948 949 /* 950 * For O_DSYNC we set both IO_SYNC and IO_DATASYNC, so that VOP_WRITE() 951 * or VOP_DEALLOCATE() implementations that don't understand IO_DATASYNC 952 * fall back to full O_SYNC behavior. 953 */ 954 if ((fp->f_flag & O_DSYNC) != 0) 955 ioflag |= IO_SYNC | IO_DATASYNC; 956 957 return (ioflag); 958 } 959 960 int 961 vn_read_from_obj(struct vnode *vp, struct uio *uio) 962 { 963 vm_object_t obj; 964 vm_page_t ma[io_hold_cnt + 2]; 965 off_t off, vsz; 966 ssize_t resid; 967 int error, i, j; 968 969 MPASS(uio->uio_resid <= ptoa(io_hold_cnt + 2)); 970 obj = atomic_load_ptr(&vp->v_object); 971 if (obj == NULL) 972 return (EJUSTRETURN); 973 974 /* 975 * Depends on type stability of vm_objects. 976 */ 977 vm_object_pip_add(obj, 1); 978 if ((obj->flags & OBJ_DEAD) != 0) { 979 /* 980 * Note that object might be already reused from the 981 * vnode, and the OBJ_DEAD flag cleared. This is fine, 982 * we recheck for DOOMED vnode state after all pages 983 * are busied, and retract then. 984 * 985 * But we check for OBJ_DEAD to ensure that we do not 986 * busy pages while vm_object_terminate_pages() 987 * processes the queue. 988 */ 989 error = EJUSTRETURN; 990 goto out_pip; 991 } 992 993 resid = uio->uio_resid; 994 off = uio->uio_offset; 995 for (i = 0; resid > 0; i++) { 996 MPASS(i < io_hold_cnt + 2); 997 ma[i] = vm_page_grab_unlocked(obj, atop(off), 998 VM_ALLOC_NOCREAT | VM_ALLOC_SBUSY | VM_ALLOC_IGN_SBUSY | 999 VM_ALLOC_NOWAIT); 1000 if (ma[i] == NULL) 1001 break; 1002 1003 /* 1004 * Skip invalid pages. Valid mask can be partial only 1005 * at EOF, and we clip later. 1006 */ 1007 if (vm_page_none_valid(ma[i])) { 1008 vm_page_sunbusy(ma[i]); 1009 break; 1010 } 1011 1012 resid -= PAGE_SIZE; 1013 off += PAGE_SIZE; 1014 } 1015 if (i == 0) { 1016 error = EJUSTRETURN; 1017 goto out_pip; 1018 } 1019 1020 /* 1021 * Check VIRF_DOOMED after we busied our pages. Since 1022 * vgonel() terminates the vnode' vm_object, it cannot 1023 * process past pages busied by us. 1024 */ 1025 if (VN_IS_DOOMED(vp)) { 1026 error = EJUSTRETURN; 1027 goto out; 1028 } 1029 1030 resid = PAGE_SIZE - (uio->uio_offset & PAGE_MASK) + ptoa(i - 1); 1031 if (resid > uio->uio_resid) 1032 resid = uio->uio_resid; 1033 1034 /* 1035 * Unlocked read of vnp_size is safe because truncation cannot 1036 * pass busied page. But we load vnp_size into a local 1037 * variable so that possible concurrent extension does not 1038 * break calculation. 1039 */ 1040 #if defined(__powerpc__) && !defined(__powerpc64__) 1041 vsz = obj->un_pager.vnp.vnp_size; 1042 #else 1043 vsz = atomic_load_64(&obj->un_pager.vnp.vnp_size); 1044 #endif 1045 if (uio->uio_offset >= vsz) { 1046 error = EJUSTRETURN; 1047 goto out; 1048 } 1049 if (uio->uio_offset + resid > vsz) 1050 resid = vsz - uio->uio_offset; 1051 1052 error = vn_io_fault_pgmove(ma, uio->uio_offset & PAGE_MASK, resid, uio); 1053 1054 out: 1055 for (j = 0; j < i; j++) { 1056 if (error == 0) 1057 vm_page_reference(ma[j]); 1058 vm_page_sunbusy(ma[j]); 1059 } 1060 out_pip: 1061 vm_object_pip_wakeup(obj); 1062 if (error != 0) 1063 return (error); 1064 return (uio->uio_resid == 0 ? 0 : EJUSTRETURN); 1065 } 1066 1067 /* 1068 * File table vnode read routine. 1069 */ 1070 static int 1071 vn_read(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags, 1072 struct thread *td) 1073 { 1074 struct vnode *vp; 1075 off_t orig_offset; 1076 int error, ioflag; 1077 int advice; 1078 1079 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", 1080 uio->uio_td, td)); 1081 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET")); 1082 vp = fp->f_vnode; 1083 ioflag = 0; 1084 if (fp->f_flag & FNONBLOCK) 1085 ioflag |= IO_NDELAY; 1086 if (fp->f_flag & O_DIRECT) 1087 ioflag |= IO_DIRECT; 1088 1089 /* 1090 * Try to read from page cache. VIRF_DOOMED check is racy but 1091 * allows us to avoid unneeded work outright. 1092 */ 1093 if (vn_io_pgcache_read_enable && !mac_vnode_check_read_enabled() && 1094 (vn_irflag_read(vp) & (VIRF_DOOMED | VIRF_PGREAD)) == VIRF_PGREAD) { 1095 error = VOP_READ_PGCACHE(vp, uio, ioflag, fp->f_cred); 1096 if (error == 0) { 1097 fp->f_nextoff[UIO_READ] = uio->uio_offset; 1098 return (0); 1099 } 1100 if (error != EJUSTRETURN) 1101 return (error); 1102 } 1103 1104 advice = get_advice(fp, uio); 1105 vn_lock(vp, LK_SHARED | LK_RETRY); 1106 1107 switch (advice) { 1108 case POSIX_FADV_NORMAL: 1109 case POSIX_FADV_SEQUENTIAL: 1110 case POSIX_FADV_NOREUSE: 1111 ioflag |= sequential_heuristic(uio, fp); 1112 break; 1113 case POSIX_FADV_RANDOM: 1114 /* Disable read-ahead for random I/O. */ 1115 break; 1116 } 1117 orig_offset = uio->uio_offset; 1118 1119 #ifdef MAC 1120 error = mac_vnode_check_read(active_cred, fp->f_cred, vp); 1121 if (error == 0) 1122 #endif 1123 error = VOP_READ(vp, uio, ioflag, fp->f_cred); 1124 fp->f_nextoff[UIO_READ] = uio->uio_offset; 1125 VOP_UNLOCK(vp); 1126 if (error == 0 && advice == POSIX_FADV_NOREUSE && 1127 orig_offset != uio->uio_offset) 1128 /* 1129 * Use POSIX_FADV_DONTNEED to flush pages and buffers 1130 * for the backing file after a POSIX_FADV_NOREUSE 1131 * read(2). 1132 */ 1133 error = VOP_ADVISE(vp, orig_offset, uio->uio_offset - 1, 1134 POSIX_FADV_DONTNEED); 1135 return (error); 1136 } 1137 1138 /* 1139 * File table vnode write routine. 1140 */ 1141 static int 1142 vn_write(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags, 1143 struct thread *td) 1144 { 1145 struct vnode *vp; 1146 struct mount *mp; 1147 off_t orig_offset; 1148 int error, ioflag; 1149 int advice; 1150 bool need_finished_write; 1151 1152 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", 1153 uio->uio_td, td)); 1154 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET")); 1155 vp = fp->f_vnode; 1156 if (vp->v_type == VREG) 1157 bwillwrite(); 1158 ioflag = IO_UNIT; 1159 if (vp->v_type == VREG && (fp->f_flag & O_APPEND) != 0) 1160 ioflag |= IO_APPEND; 1161 if ((fp->f_flag & FNONBLOCK) != 0) 1162 ioflag |= IO_NDELAY; 1163 ioflag |= get_write_ioflag(fp); 1164 1165 mp = NULL; 1166 need_finished_write = false; 1167 if (vp->v_type != VCHR) { 1168 error = vn_start_write(vp, &mp, V_WAIT | V_PCATCH); 1169 if (error != 0) 1170 goto unlock; 1171 need_finished_write = true; 1172 } 1173 1174 advice = get_advice(fp, uio); 1175 1176 vn_lock(vp, vn_lktype_write(mp, vp) | LK_RETRY); 1177 switch (advice) { 1178 case POSIX_FADV_NORMAL: 1179 case POSIX_FADV_SEQUENTIAL: 1180 case POSIX_FADV_NOREUSE: 1181 ioflag |= sequential_heuristic(uio, fp); 1182 break; 1183 case POSIX_FADV_RANDOM: 1184 /* XXX: Is this correct? */ 1185 break; 1186 } 1187 orig_offset = uio->uio_offset; 1188 1189 #ifdef MAC 1190 error = mac_vnode_check_write(active_cred, fp->f_cred, vp); 1191 if (error == 0) 1192 #endif 1193 error = VOP_WRITE(vp, uio, ioflag, fp->f_cred); 1194 fp->f_nextoff[UIO_WRITE] = uio->uio_offset; 1195 VOP_UNLOCK(vp); 1196 if (need_finished_write) 1197 vn_finished_write(mp); 1198 if (error == 0 && advice == POSIX_FADV_NOREUSE && 1199 orig_offset != uio->uio_offset) 1200 /* 1201 * Use POSIX_FADV_DONTNEED to flush pages and buffers 1202 * for the backing file after a POSIX_FADV_NOREUSE 1203 * write(2). 1204 */ 1205 error = VOP_ADVISE(vp, orig_offset, uio->uio_offset - 1, 1206 POSIX_FADV_DONTNEED); 1207 unlock: 1208 return (error); 1209 } 1210 1211 /* 1212 * The vn_io_fault() is a wrapper around vn_read() and vn_write() to 1213 * prevent the following deadlock: 1214 * 1215 * Assume that the thread A reads from the vnode vp1 into userspace 1216 * buffer buf1 backed by the pages of vnode vp2. If a page in buf1 is 1217 * currently not resident, then system ends up with the call chain 1218 * vn_read() -> VOP_READ(vp1) -> uiomove() -> [Page Fault] -> 1219 * vm_fault(buf1) -> vnode_pager_getpages(vp2) -> VOP_GETPAGES(vp2) 1220 * which establishes lock order vp1->vn_lock, then vp2->vn_lock. 1221 * If, at the same time, thread B reads from vnode vp2 into buffer buf2 1222 * backed by the pages of vnode vp1, and some page in buf2 is not 1223 * resident, we get a reversed order vp2->vn_lock, then vp1->vn_lock. 1224 * 1225 * To prevent the lock order reversal and deadlock, vn_io_fault() does 1226 * not allow page faults to happen during VOP_READ() or VOP_WRITE(). 1227 * Instead, it first tries to do the whole range i/o with pagefaults 1228 * disabled. If all pages in the i/o buffer are resident and mapped, 1229 * VOP will succeed (ignoring the genuine filesystem errors). 1230 * Otherwise, we get back EFAULT, and vn_io_fault() falls back to do 1231 * i/o in chunks, with all pages in the chunk prefaulted and held 1232 * using vm_fault_quick_hold_pages(). 1233 * 1234 * Filesystems using this deadlock avoidance scheme should use the 1235 * array of the held pages from uio, saved in the curthread->td_ma, 1236 * instead of doing uiomove(). A helper function 1237 * vn_io_fault_uiomove() converts uiomove request into 1238 * uiomove_fromphys() over td_ma array. 1239 * 1240 * Since vnode locks do not cover the whole i/o anymore, rangelocks 1241 * make the current i/o request atomic with respect to other i/os and 1242 * truncations. 1243 */ 1244 1245 /* 1246 * Decode vn_io_fault_args and perform the corresponding i/o. 1247 */ 1248 static int 1249 vn_io_fault_doio(struct vn_io_fault_args *args, struct uio *uio, 1250 struct thread *td) 1251 { 1252 int error, save; 1253 1254 error = 0; 1255 save = vm_fault_disable_pagefaults(); 1256 switch (args->kind) { 1257 case VN_IO_FAULT_FOP: 1258 error = (args->args.fop_args.doio)(args->args.fop_args.fp, 1259 uio, args->cred, args->flags, td); 1260 break; 1261 case VN_IO_FAULT_VOP: 1262 if (uio->uio_rw == UIO_READ) { 1263 error = VOP_READ(args->args.vop_args.vp, uio, 1264 args->flags, args->cred); 1265 } else if (uio->uio_rw == UIO_WRITE) { 1266 error = VOP_WRITE(args->args.vop_args.vp, uio, 1267 args->flags, args->cred); 1268 } 1269 break; 1270 default: 1271 panic("vn_io_fault_doio: unknown kind of io %d %d", 1272 args->kind, uio->uio_rw); 1273 } 1274 vm_fault_enable_pagefaults(save); 1275 return (error); 1276 } 1277 1278 static int 1279 vn_io_fault_touch(char *base, const struct uio *uio) 1280 { 1281 int r; 1282 1283 r = fubyte(base); 1284 if (r == -1 || (uio->uio_rw == UIO_READ && subyte(base, r) == -1)) 1285 return (EFAULT); 1286 return (0); 1287 } 1288 1289 static int 1290 vn_io_fault_prefault_user(const struct uio *uio) 1291 { 1292 char *base; 1293 const struct iovec *iov; 1294 size_t len; 1295 ssize_t resid; 1296 int error, i; 1297 1298 KASSERT(uio->uio_segflg == UIO_USERSPACE, 1299 ("vn_io_fault_prefault userspace")); 1300 1301 error = i = 0; 1302 iov = uio->uio_iov; 1303 resid = uio->uio_resid; 1304 base = iov->iov_base; 1305 len = iov->iov_len; 1306 while (resid > 0) { 1307 error = vn_io_fault_touch(base, uio); 1308 if (error != 0) 1309 break; 1310 if (len < PAGE_SIZE) { 1311 if (len != 0) { 1312 error = vn_io_fault_touch(base + len - 1, uio); 1313 if (error != 0) 1314 break; 1315 resid -= len; 1316 } 1317 if (++i >= uio->uio_iovcnt) 1318 break; 1319 iov = uio->uio_iov + i; 1320 base = iov->iov_base; 1321 len = iov->iov_len; 1322 } else { 1323 len -= PAGE_SIZE; 1324 base += PAGE_SIZE; 1325 resid -= PAGE_SIZE; 1326 } 1327 } 1328 return (error); 1329 } 1330 1331 /* 1332 * Common code for vn_io_fault(), agnostic to the kind of i/o request. 1333 * Uses vn_io_fault_doio() to make the call to an actual i/o function. 1334 * Used from vn_rdwr() and vn_io_fault(), which encode the i/o request 1335 * into args and call vn_io_fault1() to handle faults during the user 1336 * mode buffer accesses. 1337 */ 1338 static int 1339 vn_io_fault1(struct vnode *vp, struct uio *uio, struct vn_io_fault_args *args, 1340 struct thread *td) 1341 { 1342 vm_page_t ma[io_hold_cnt + 2]; 1343 struct uio *uio_clone, short_uio; 1344 struct iovec short_iovec[1]; 1345 vm_page_t *prev_td_ma; 1346 vm_prot_t prot; 1347 vm_offset_t addr, end; 1348 size_t len, resid; 1349 ssize_t adv; 1350 int error, cnt, saveheld, prev_td_ma_cnt; 1351 1352 if (vn_io_fault_prefault) { 1353 error = vn_io_fault_prefault_user(uio); 1354 if (error != 0) 1355 return (error); /* Or ignore ? */ 1356 } 1357 1358 prot = uio->uio_rw == UIO_READ ? VM_PROT_WRITE : VM_PROT_READ; 1359 1360 /* 1361 * The UFS follows IO_UNIT directive and replays back both 1362 * uio_offset and uio_resid if an error is encountered during the 1363 * operation. But, since the iovec may be already advanced, 1364 * uio is still in an inconsistent state. 1365 * 1366 * Cache a copy of the original uio, which is advanced to the redo 1367 * point using UIO_NOCOPY below. 1368 */ 1369 uio_clone = cloneuio(uio); 1370 resid = uio->uio_resid; 1371 1372 short_uio.uio_segflg = UIO_USERSPACE; 1373 short_uio.uio_rw = uio->uio_rw; 1374 short_uio.uio_td = uio->uio_td; 1375 1376 error = vn_io_fault_doio(args, uio, td); 1377 if (error != EFAULT) 1378 goto out; 1379 1380 atomic_add_long(&vn_io_faults_cnt, 1); 1381 uio_clone->uio_segflg = UIO_NOCOPY; 1382 uiomove(NULL, resid - uio->uio_resid, uio_clone); 1383 uio_clone->uio_segflg = uio->uio_segflg; 1384 1385 saveheld = curthread_pflags_set(TDP_UIOHELD); 1386 prev_td_ma = td->td_ma; 1387 prev_td_ma_cnt = td->td_ma_cnt; 1388 1389 while (uio_clone->uio_resid != 0) { 1390 len = uio_clone->uio_iov->iov_len; 1391 if (len == 0) { 1392 KASSERT(uio_clone->uio_iovcnt >= 1, 1393 ("iovcnt underflow")); 1394 uio_clone->uio_iov++; 1395 uio_clone->uio_iovcnt--; 1396 continue; 1397 } 1398 if (len > ptoa(io_hold_cnt)) 1399 len = ptoa(io_hold_cnt); 1400 addr = (uintptr_t)uio_clone->uio_iov->iov_base; 1401 end = round_page(addr + len); 1402 if (end < addr) { 1403 error = EFAULT; 1404 break; 1405 } 1406 /* 1407 * A perfectly misaligned address and length could cause 1408 * both the start and the end of the chunk to use partial 1409 * page. +2 accounts for such a situation. 1410 */ 1411 cnt = vm_fault_quick_hold_pages(&td->td_proc->p_vmspace->vm_map, 1412 addr, len, prot, ma, io_hold_cnt + 2); 1413 if (cnt == -1) { 1414 error = EFAULT; 1415 break; 1416 } 1417 short_uio.uio_iov = &short_iovec[0]; 1418 short_iovec[0].iov_base = (void *)addr; 1419 short_uio.uio_iovcnt = 1; 1420 short_uio.uio_resid = short_iovec[0].iov_len = len; 1421 short_uio.uio_offset = uio_clone->uio_offset; 1422 td->td_ma = ma; 1423 td->td_ma_cnt = cnt; 1424 1425 error = vn_io_fault_doio(args, &short_uio, td); 1426 vm_page_unhold_pages(ma, cnt); 1427 adv = len - short_uio.uio_resid; 1428 1429 uio_clone->uio_iov->iov_base = 1430 (char *)uio_clone->uio_iov->iov_base + adv; 1431 uio_clone->uio_iov->iov_len -= adv; 1432 uio_clone->uio_resid -= adv; 1433 uio_clone->uio_offset += adv; 1434 1435 uio->uio_resid -= adv; 1436 uio->uio_offset += adv; 1437 1438 if (error != 0 || adv == 0) 1439 break; 1440 } 1441 td->td_ma = prev_td_ma; 1442 td->td_ma_cnt = prev_td_ma_cnt; 1443 curthread_pflags_restore(saveheld); 1444 out: 1445 freeuio(uio_clone); 1446 return (error); 1447 } 1448 1449 static int 1450 vn_io_fault(struct file *fp, struct uio *uio, struct ucred *active_cred, 1451 int flags, struct thread *td) 1452 { 1453 fo_rdwr_t *doio; 1454 struct vnode *vp; 1455 void *rl_cookie; 1456 struct vn_io_fault_args args; 1457 int error; 1458 bool do_io_fault, do_rangelock; 1459 1460 doio = uio->uio_rw == UIO_READ ? vn_read : vn_write; 1461 vp = fp->f_vnode; 1462 1463 /* 1464 * The ability to read(2) on a directory has historically been 1465 * allowed for all users, but this can and has been the source of 1466 * at least one security issue in the past. As such, it is now hidden 1467 * away behind a sysctl for those that actually need it to use it, and 1468 * restricted to root when it's turned on to make it relatively safe to 1469 * leave on for longer sessions of need. 1470 */ 1471 if (vp->v_type == VDIR) { 1472 KASSERT(uio->uio_rw == UIO_READ, 1473 ("illegal write attempted on a directory")); 1474 if (!vfs_allow_read_dir) 1475 return (EISDIR); 1476 if ((error = priv_check(td, PRIV_VFS_READ_DIR)) != 0) 1477 return (EISDIR); 1478 } 1479 1480 do_io_fault = do_vn_io_fault(vp, uio); 1481 do_rangelock = do_io_fault || (vn_irflag_read(vp) & VIRF_PGREAD) != 0; 1482 foffset_lock_uio(fp, uio, flags); 1483 if (do_rangelock) { 1484 if (uio->uio_rw == UIO_READ) { 1485 rl_cookie = vn_rangelock_rlock(vp, uio->uio_offset, 1486 uio->uio_offset + uio->uio_resid); 1487 } else if ((fp->f_flag & O_APPEND) != 0 || 1488 (flags & FOF_OFFSET) == 0) { 1489 /* For appenders, punt and lock the whole range. */ 1490 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 1491 } else { 1492 rl_cookie = vn_rangelock_wlock(vp, uio->uio_offset, 1493 uio->uio_offset + uio->uio_resid); 1494 } 1495 } 1496 if (do_io_fault) { 1497 args.kind = VN_IO_FAULT_FOP; 1498 args.args.fop_args.fp = fp; 1499 args.args.fop_args.doio = doio; 1500 args.cred = active_cred; 1501 args.flags = flags | FOF_OFFSET; 1502 error = vn_io_fault1(vp, uio, &args, td); 1503 } else { 1504 error = doio(fp, uio, active_cred, flags | FOF_OFFSET, td); 1505 } 1506 if (do_rangelock) 1507 vn_rangelock_unlock(vp, rl_cookie); 1508 foffset_unlock_uio(fp, uio, flags); 1509 return (error); 1510 } 1511 1512 /* 1513 * Helper function to perform the requested uiomove operation using 1514 * the held pages for io->uio_iov[0].iov_base buffer instead of 1515 * copyin/copyout. Access to the pages with uiomove_fromphys() 1516 * instead of iov_base prevents page faults that could occur due to 1517 * pmap_collect() invalidating the mapping created by 1518 * vm_fault_quick_hold_pages(), or pageout daemon, page laundry or 1519 * object cleanup revoking the write access from page mappings. 1520 * 1521 * Filesystems specified MNTK_NO_IOPF shall use vn_io_fault_uiomove() 1522 * instead of plain uiomove(). 1523 */ 1524 int 1525 vn_io_fault_uiomove(char *data, int xfersize, struct uio *uio) 1526 { 1527 struct uio transp_uio; 1528 struct iovec transp_iov[1]; 1529 struct thread *td; 1530 size_t adv; 1531 int error, pgadv; 1532 1533 td = curthread; 1534 if ((td->td_pflags & TDP_UIOHELD) == 0 || 1535 uio->uio_segflg != UIO_USERSPACE) 1536 return (uiomove(data, xfersize, uio)); 1537 1538 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt)); 1539 transp_iov[0].iov_base = data; 1540 transp_uio.uio_iov = &transp_iov[0]; 1541 transp_uio.uio_iovcnt = 1; 1542 if (xfersize > uio->uio_resid) 1543 xfersize = uio->uio_resid; 1544 transp_uio.uio_resid = transp_iov[0].iov_len = xfersize; 1545 transp_uio.uio_offset = 0; 1546 transp_uio.uio_segflg = UIO_SYSSPACE; 1547 /* 1548 * Since transp_iov points to data, and td_ma page array 1549 * corresponds to original uio->uio_iov, we need to invert the 1550 * direction of the i/o operation as passed to 1551 * uiomove_fromphys(). 1552 */ 1553 switch (uio->uio_rw) { 1554 case UIO_WRITE: 1555 transp_uio.uio_rw = UIO_READ; 1556 break; 1557 case UIO_READ: 1558 transp_uio.uio_rw = UIO_WRITE; 1559 break; 1560 } 1561 transp_uio.uio_td = uio->uio_td; 1562 error = uiomove_fromphys(td->td_ma, 1563 ((vm_offset_t)uio->uio_iov->iov_base) & PAGE_MASK, 1564 xfersize, &transp_uio); 1565 adv = xfersize - transp_uio.uio_resid; 1566 pgadv = 1567 (((vm_offset_t)uio->uio_iov->iov_base + adv) >> PAGE_SHIFT) - 1568 (((vm_offset_t)uio->uio_iov->iov_base) >> PAGE_SHIFT); 1569 td->td_ma += pgadv; 1570 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt, 1571 pgadv)); 1572 td->td_ma_cnt -= pgadv; 1573 uio->uio_iov->iov_base = (char *)uio->uio_iov->iov_base + adv; 1574 uio->uio_iov->iov_len -= adv; 1575 uio->uio_resid -= adv; 1576 uio->uio_offset += adv; 1577 return (error); 1578 } 1579 1580 int 1581 vn_io_fault_pgmove(vm_page_t ma[], vm_offset_t offset, int xfersize, 1582 struct uio *uio) 1583 { 1584 struct thread *td; 1585 vm_offset_t iov_base; 1586 int cnt, pgadv; 1587 1588 td = curthread; 1589 if ((td->td_pflags & TDP_UIOHELD) == 0 || 1590 uio->uio_segflg != UIO_USERSPACE) 1591 return (uiomove_fromphys(ma, offset, xfersize, uio)); 1592 1593 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt)); 1594 cnt = xfersize > uio->uio_resid ? uio->uio_resid : xfersize; 1595 iov_base = (vm_offset_t)uio->uio_iov->iov_base; 1596 switch (uio->uio_rw) { 1597 case UIO_WRITE: 1598 pmap_copy_pages(td->td_ma, iov_base & PAGE_MASK, ma, 1599 offset, cnt); 1600 break; 1601 case UIO_READ: 1602 pmap_copy_pages(ma, offset, td->td_ma, iov_base & PAGE_MASK, 1603 cnt); 1604 break; 1605 } 1606 pgadv = ((iov_base + cnt) >> PAGE_SHIFT) - (iov_base >> PAGE_SHIFT); 1607 td->td_ma += pgadv; 1608 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt, 1609 pgadv)); 1610 td->td_ma_cnt -= pgadv; 1611 uio->uio_iov->iov_base = (char *)(iov_base + cnt); 1612 uio->uio_iov->iov_len -= cnt; 1613 uio->uio_resid -= cnt; 1614 uio->uio_offset += cnt; 1615 return (0); 1616 } 1617 1618 /* 1619 * File table truncate routine. 1620 */ 1621 static int 1622 vn_truncate(struct file *fp, off_t length, struct ucred *active_cred, 1623 struct thread *td) 1624 { 1625 struct mount *mp; 1626 struct vnode *vp; 1627 void *rl_cookie; 1628 int error; 1629 1630 vp = fp->f_vnode; 1631 1632 retry: 1633 /* 1634 * Lock the whole range for truncation. Otherwise split i/o 1635 * might happen partly before and partly after the truncation. 1636 */ 1637 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 1638 error = vn_start_write(vp, &mp, V_WAIT | V_PCATCH); 1639 if (error) 1640 goto out1; 1641 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1642 AUDIT_ARG_VNODE1(vp); 1643 if (vp->v_type == VDIR) { 1644 error = EISDIR; 1645 goto out; 1646 } 1647 #ifdef MAC 1648 error = mac_vnode_check_write(active_cred, fp->f_cred, vp); 1649 if (error) 1650 goto out; 1651 #endif 1652 error = vn_truncate_locked(vp, length, (fp->f_flag & O_FSYNC) != 0, 1653 fp->f_cred); 1654 out: 1655 VOP_UNLOCK(vp); 1656 vn_finished_write(mp); 1657 out1: 1658 vn_rangelock_unlock(vp, rl_cookie); 1659 if (error == ERELOOKUP) 1660 goto retry; 1661 return (error); 1662 } 1663 1664 /* 1665 * Truncate a file that is already locked. 1666 */ 1667 int 1668 vn_truncate_locked(struct vnode *vp, off_t length, bool sync, 1669 struct ucred *cred) 1670 { 1671 struct vattr vattr; 1672 int error; 1673 1674 error = VOP_ADD_WRITECOUNT(vp, 1); 1675 if (error == 0) { 1676 VATTR_NULL(&vattr); 1677 vattr.va_size = length; 1678 if (sync) 1679 vattr.va_vaflags |= VA_SYNC; 1680 error = VOP_SETATTR(vp, &vattr, cred); 1681 VOP_ADD_WRITECOUNT_CHECKED(vp, -1); 1682 } 1683 return (error); 1684 } 1685 1686 /* 1687 * File table vnode stat routine. 1688 */ 1689 int 1690 vn_statfile(struct file *fp, struct stat *sb, struct ucred *active_cred) 1691 { 1692 struct vnode *vp = fp->f_vnode; 1693 int error; 1694 1695 vn_lock(vp, LK_SHARED | LK_RETRY); 1696 error = VOP_STAT(vp, sb, active_cred, fp->f_cred); 1697 VOP_UNLOCK(vp); 1698 1699 return (error); 1700 } 1701 1702 /* 1703 * File table vnode ioctl routine. 1704 */ 1705 static int 1706 vn_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 1707 struct thread *td) 1708 { 1709 struct vnode *vp; 1710 struct fiobmap2_arg *bmarg; 1711 off_t size; 1712 int error; 1713 1714 vp = fp->f_vnode; 1715 switch (vp->v_type) { 1716 case VDIR: 1717 case VREG: 1718 switch (com) { 1719 case FIONREAD: 1720 error = vn_getsize(vp, &size, active_cred); 1721 if (error == 0) 1722 *(int *)data = size - fp->f_offset; 1723 return (error); 1724 case FIOBMAP2: 1725 bmarg = (struct fiobmap2_arg *)data; 1726 vn_lock(vp, LK_SHARED | LK_RETRY); 1727 #ifdef MAC 1728 error = mac_vnode_check_read(active_cred, fp->f_cred, 1729 vp); 1730 if (error == 0) 1731 #endif 1732 error = VOP_BMAP(vp, bmarg->bn, NULL, 1733 &bmarg->bn, &bmarg->runp, &bmarg->runb); 1734 VOP_UNLOCK(vp); 1735 return (error); 1736 case FIONBIO: 1737 case FIOASYNC: 1738 return (0); 1739 default: 1740 return (VOP_IOCTL(vp, com, data, fp->f_flag, 1741 active_cred, td)); 1742 } 1743 break; 1744 case VCHR: 1745 return (VOP_IOCTL(vp, com, data, fp->f_flag, 1746 active_cred, td)); 1747 default: 1748 return (ENOTTY); 1749 } 1750 } 1751 1752 /* 1753 * File table vnode poll routine. 1754 */ 1755 static int 1756 vn_poll(struct file *fp, int events, struct ucred *active_cred, 1757 struct thread *td) 1758 { 1759 struct vnode *vp; 1760 int error; 1761 1762 vp = fp->f_vnode; 1763 #if defined(MAC) || defined(AUDIT) 1764 if (AUDITING_TD(td) || mac_vnode_check_poll_enabled()) { 1765 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1766 AUDIT_ARG_VNODE1(vp); 1767 error = mac_vnode_check_poll(active_cred, fp->f_cred, vp); 1768 VOP_UNLOCK(vp); 1769 if (error != 0) 1770 return (error); 1771 } 1772 #endif 1773 error = VOP_POLL(vp, events, fp->f_cred, td); 1774 return (error); 1775 } 1776 1777 /* 1778 * Acquire the requested lock and then check for validity. LK_RETRY 1779 * permits vn_lock to return doomed vnodes. 1780 */ 1781 static int __noinline 1782 _vn_lock_fallback(struct vnode *vp, int flags, const char *file, int line, 1783 int error) 1784 { 1785 1786 KASSERT((flags & LK_RETRY) == 0 || error == 0, 1787 ("vn_lock: error %d incompatible with flags %#x", error, flags)); 1788 1789 if (error == 0) 1790 VNASSERT(VN_IS_DOOMED(vp), vp, ("vnode not doomed")); 1791 1792 if ((flags & LK_RETRY) == 0) { 1793 if (error == 0) { 1794 VOP_UNLOCK(vp); 1795 error = ENOENT; 1796 } 1797 return (error); 1798 } 1799 1800 /* 1801 * LK_RETRY case. 1802 * 1803 * Nothing to do if we got the lock. 1804 */ 1805 if (error == 0) 1806 return (0); 1807 1808 /* 1809 * Interlock was dropped by the call in _vn_lock. 1810 */ 1811 flags &= ~LK_INTERLOCK; 1812 do { 1813 error = VOP_LOCK1(vp, flags, file, line); 1814 } while (error != 0); 1815 return (0); 1816 } 1817 1818 int 1819 _vn_lock(struct vnode *vp, int flags, const char *file, int line) 1820 { 1821 int error; 1822 1823 VNASSERT((flags & LK_TYPE_MASK) != 0, vp, 1824 ("vn_lock: no locktype (%d passed)", flags)); 1825 VNPASS(vp->v_holdcnt > 0, vp); 1826 error = VOP_LOCK1(vp, flags, file, line); 1827 if (__predict_false(error != 0 || VN_IS_DOOMED(vp))) 1828 return (_vn_lock_fallback(vp, flags, file, line, error)); 1829 return (0); 1830 } 1831 1832 /* 1833 * File table vnode close routine. 1834 */ 1835 static int 1836 vn_closefile(struct file *fp, struct thread *td) 1837 { 1838 struct vnode *vp; 1839 struct flock lf; 1840 int error; 1841 bool ref; 1842 1843 vp = fp->f_vnode; 1844 fp->f_ops = &badfileops; 1845 ref = (fp->f_flag & FHASLOCK) != 0; 1846 1847 error = vn_close1(vp, fp->f_flag, fp->f_cred, td, ref); 1848 1849 if (__predict_false(ref)) { 1850 lf.l_whence = SEEK_SET; 1851 lf.l_start = 0; 1852 lf.l_len = 0; 1853 lf.l_type = F_UNLCK; 1854 (void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, F_FLOCK); 1855 vrele(vp); 1856 } 1857 return (error); 1858 } 1859 1860 /* 1861 * Preparing to start a filesystem write operation. If the operation is 1862 * permitted, then we bump the count of operations in progress and 1863 * proceed. If a suspend request is in progress, we wait until the 1864 * suspension is over, and then proceed. 1865 */ 1866 static int 1867 vn_start_write_refed(struct mount *mp, int flags, bool mplocked) 1868 { 1869 struct mount_pcpu *mpcpu; 1870 int error, mflags; 1871 1872 if (__predict_true(!mplocked) && (flags & V_XSLEEP) == 0 && 1873 vfs_op_thread_enter(mp, mpcpu)) { 1874 MPASS((mp->mnt_kern_flag & MNTK_SUSPEND) == 0); 1875 vfs_mp_count_add_pcpu(mpcpu, writeopcount, 1); 1876 vfs_op_thread_exit(mp, mpcpu); 1877 return (0); 1878 } 1879 1880 if (mplocked) 1881 mtx_assert(MNT_MTX(mp), MA_OWNED); 1882 else 1883 MNT_ILOCK(mp); 1884 1885 error = 0; 1886 1887 /* 1888 * Check on status of suspension. 1889 */ 1890 if ((curthread->td_pflags & TDP_IGNSUSP) == 0 || 1891 mp->mnt_susp_owner != curthread) { 1892 mflags = 0; 1893 if ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0) { 1894 if (flags & V_PCATCH) 1895 mflags |= PCATCH; 1896 } 1897 mflags |= (PUSER - 1); 1898 while ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { 1899 if ((flags & V_NOWAIT) != 0) { 1900 error = EWOULDBLOCK; 1901 goto unlock; 1902 } 1903 error = msleep(&mp->mnt_flag, MNT_MTX(mp), mflags, 1904 "suspfs", 0); 1905 if (error != 0) 1906 goto unlock; 1907 } 1908 } 1909 if ((flags & V_XSLEEP) != 0) 1910 goto unlock; 1911 mp->mnt_writeopcount++; 1912 unlock: 1913 if (error != 0 || (flags & V_XSLEEP) != 0) 1914 MNT_REL(mp); 1915 MNT_IUNLOCK(mp); 1916 return (error); 1917 } 1918 1919 int 1920 vn_start_write(struct vnode *vp, struct mount **mpp, int flags) 1921 { 1922 struct mount *mp; 1923 int error; 1924 1925 KASSERT((flags & ~V_VALID_FLAGS) == 0, 1926 ("%s: invalid flags passed %d\n", __func__, flags)); 1927 1928 error = 0; 1929 /* 1930 * If a vnode is provided, get and return the mount point that 1931 * to which it will write. 1932 */ 1933 if (vp != NULL) { 1934 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) { 1935 *mpp = NULL; 1936 if (error != EOPNOTSUPP) 1937 return (error); 1938 return (0); 1939 } 1940 } 1941 if ((mp = *mpp) == NULL) 1942 return (0); 1943 1944 /* 1945 * VOP_GETWRITEMOUNT() returns with the mp refcount held through 1946 * a vfs_ref(). 1947 * As long as a vnode is not provided we need to acquire a 1948 * refcount for the provided mountpoint too, in order to 1949 * emulate a vfs_ref(). 1950 */ 1951 if (vp == NULL) 1952 vfs_ref(mp); 1953 1954 error = vn_start_write_refed(mp, flags, false); 1955 if (error != 0 && (flags & V_NOWAIT) == 0) 1956 *mpp = NULL; 1957 return (error); 1958 } 1959 1960 /* 1961 * Secondary suspension. Used by operations such as vop_inactive 1962 * routines that are needed by the higher level functions. These 1963 * are allowed to proceed until all the higher level functions have 1964 * completed (indicated by mnt_writeopcount dropping to zero). At that 1965 * time, these operations are halted until the suspension is over. 1966 */ 1967 int 1968 vn_start_secondary_write(struct vnode *vp, struct mount **mpp, int flags) 1969 { 1970 struct mount *mp; 1971 int error, mflags; 1972 1973 KASSERT((flags & (~V_VALID_FLAGS | V_XSLEEP)) == 0, 1974 ("%s: invalid flags passed %d\n", __func__, flags)); 1975 1976 retry: 1977 if (vp != NULL) { 1978 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) { 1979 *mpp = NULL; 1980 if (error != EOPNOTSUPP) 1981 return (error); 1982 return (0); 1983 } 1984 } 1985 /* 1986 * If we are not suspended or have not yet reached suspended 1987 * mode, then let the operation proceed. 1988 */ 1989 if ((mp = *mpp) == NULL) 1990 return (0); 1991 1992 /* 1993 * VOP_GETWRITEMOUNT() returns with the mp refcount held through 1994 * a vfs_ref(). 1995 * As long as a vnode is not provided we need to acquire a 1996 * refcount for the provided mountpoint too, in order to 1997 * emulate a vfs_ref(). 1998 */ 1999 MNT_ILOCK(mp); 2000 if (vp == NULL) 2001 MNT_REF(mp); 2002 if ((mp->mnt_kern_flag & (MNTK_SUSPENDED | MNTK_SUSPEND2)) == 0) { 2003 mp->mnt_secondary_writes++; 2004 mp->mnt_secondary_accwrites++; 2005 MNT_IUNLOCK(mp); 2006 return (0); 2007 } 2008 if ((flags & V_NOWAIT) != 0) { 2009 MNT_REL(mp); 2010 MNT_IUNLOCK(mp); 2011 *mpp = NULL; 2012 return (EWOULDBLOCK); 2013 } 2014 /* 2015 * Wait for the suspension to finish. 2016 */ 2017 mflags = 0; 2018 if ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0) { 2019 if ((flags & V_PCATCH) != 0) 2020 mflags |= PCATCH; 2021 } 2022 mflags |= (PUSER - 1) | PDROP; 2023 error = msleep(&mp->mnt_flag, MNT_MTX(mp), mflags, "suspfs", 0); 2024 vfs_rel(mp); 2025 if (error == 0) 2026 goto retry; 2027 *mpp = NULL; 2028 return (error); 2029 } 2030 2031 /* 2032 * Filesystem write operation has completed. If we are suspending and this 2033 * operation is the last one, notify the suspender that the suspension is 2034 * now in effect. 2035 */ 2036 void 2037 vn_finished_write(struct mount *mp) 2038 { 2039 struct mount_pcpu *mpcpu; 2040 int c; 2041 2042 if (mp == NULL) 2043 return; 2044 2045 if (vfs_op_thread_enter(mp, mpcpu)) { 2046 vfs_mp_count_sub_pcpu(mpcpu, writeopcount, 1); 2047 vfs_mp_count_sub_pcpu(mpcpu, ref, 1); 2048 vfs_op_thread_exit(mp, mpcpu); 2049 return; 2050 } 2051 2052 MNT_ILOCK(mp); 2053 vfs_assert_mount_counters(mp); 2054 MNT_REL(mp); 2055 c = --mp->mnt_writeopcount; 2056 if (mp->mnt_vfs_ops == 0) { 2057 MPASS((mp->mnt_kern_flag & MNTK_SUSPEND) == 0); 2058 MNT_IUNLOCK(mp); 2059 return; 2060 } 2061 if (c < 0) 2062 vfs_dump_mount_counters(mp); 2063 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && c == 0) 2064 wakeup(&mp->mnt_writeopcount); 2065 MNT_IUNLOCK(mp); 2066 } 2067 2068 /* 2069 * Filesystem secondary write operation has completed. If we are 2070 * suspending and this operation is the last one, notify the suspender 2071 * that the suspension is now in effect. 2072 */ 2073 void 2074 vn_finished_secondary_write(struct mount *mp) 2075 { 2076 if (mp == NULL) 2077 return; 2078 MNT_ILOCK(mp); 2079 MNT_REL(mp); 2080 mp->mnt_secondary_writes--; 2081 if (mp->mnt_secondary_writes < 0) 2082 panic("vn_finished_secondary_write: neg cnt"); 2083 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && 2084 mp->mnt_secondary_writes <= 0) 2085 wakeup(&mp->mnt_secondary_writes); 2086 MNT_IUNLOCK(mp); 2087 } 2088 2089 /* 2090 * Request a filesystem to suspend write operations. 2091 */ 2092 int 2093 vfs_write_suspend(struct mount *mp, int flags) 2094 { 2095 int error; 2096 2097 vfs_op_enter(mp); 2098 2099 MNT_ILOCK(mp); 2100 vfs_assert_mount_counters(mp); 2101 if (mp->mnt_susp_owner == curthread) { 2102 vfs_op_exit_locked(mp); 2103 MNT_IUNLOCK(mp); 2104 return (EALREADY); 2105 } 2106 while (mp->mnt_kern_flag & MNTK_SUSPEND) 2107 msleep(&mp->mnt_flag, MNT_MTX(mp), PUSER - 1, "wsuspfs", 0); 2108 2109 /* 2110 * Unmount holds a write reference on the mount point. If we 2111 * own busy reference and drain for writers, we deadlock with 2112 * the reference draining in the unmount path. Callers of 2113 * vfs_write_suspend() must specify VS_SKIP_UNMOUNT if 2114 * vfs_busy() reference is owned and caller is not in the 2115 * unmount context. 2116 */ 2117 if ((flags & VS_SKIP_UNMOUNT) != 0 && 2118 (mp->mnt_kern_flag & MNTK_UNMOUNT) != 0) { 2119 vfs_op_exit_locked(mp); 2120 MNT_IUNLOCK(mp); 2121 return (EBUSY); 2122 } 2123 2124 mp->mnt_kern_flag |= MNTK_SUSPEND; 2125 mp->mnt_susp_owner = curthread; 2126 if (mp->mnt_writeopcount > 0) 2127 (void) msleep(&mp->mnt_writeopcount, 2128 MNT_MTX(mp), (PUSER - 1)|PDROP, "suspwt", 0); 2129 else 2130 MNT_IUNLOCK(mp); 2131 if ((error = VFS_SYNC(mp, MNT_SUSPEND)) != 0) { 2132 vfs_write_resume(mp, 0); 2133 /* vfs_write_resume does vfs_op_exit() for us */ 2134 } 2135 return (error); 2136 } 2137 2138 /* 2139 * Request a filesystem to resume write operations. 2140 */ 2141 void 2142 vfs_write_resume(struct mount *mp, int flags) 2143 { 2144 2145 MNT_ILOCK(mp); 2146 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { 2147 KASSERT(mp->mnt_susp_owner == curthread, ("mnt_susp_owner")); 2148 mp->mnt_kern_flag &= ~(MNTK_SUSPEND | MNTK_SUSPEND2 | 2149 MNTK_SUSPENDED); 2150 mp->mnt_susp_owner = NULL; 2151 wakeup(&mp->mnt_writeopcount); 2152 wakeup(&mp->mnt_flag); 2153 curthread->td_pflags &= ~TDP_IGNSUSP; 2154 if ((flags & VR_START_WRITE) != 0) { 2155 MNT_REF(mp); 2156 mp->mnt_writeopcount++; 2157 } 2158 MNT_IUNLOCK(mp); 2159 if ((flags & VR_NO_SUSPCLR) == 0) 2160 VFS_SUSP_CLEAN(mp); 2161 vfs_op_exit(mp); 2162 } else if ((flags & VR_START_WRITE) != 0) { 2163 MNT_REF(mp); 2164 vn_start_write_refed(mp, 0, true); 2165 } else { 2166 MNT_IUNLOCK(mp); 2167 } 2168 } 2169 2170 /* 2171 * Helper loop around vfs_write_suspend() for filesystem unmount VFS 2172 * methods. 2173 */ 2174 int 2175 vfs_write_suspend_umnt(struct mount *mp) 2176 { 2177 int error; 2178 2179 KASSERT((curthread->td_pflags & TDP_IGNSUSP) == 0, 2180 ("vfs_write_suspend_umnt: recursed")); 2181 2182 /* dounmount() already called vn_start_write(). */ 2183 for (;;) { 2184 vn_finished_write(mp); 2185 error = vfs_write_suspend(mp, 0); 2186 if (error != 0) { 2187 vn_start_write(NULL, &mp, V_WAIT); 2188 return (error); 2189 } 2190 MNT_ILOCK(mp); 2191 if ((mp->mnt_kern_flag & MNTK_SUSPENDED) != 0) 2192 break; 2193 MNT_IUNLOCK(mp); 2194 vn_start_write(NULL, &mp, V_WAIT); 2195 } 2196 mp->mnt_kern_flag &= ~(MNTK_SUSPENDED | MNTK_SUSPEND2); 2197 wakeup(&mp->mnt_flag); 2198 MNT_IUNLOCK(mp); 2199 curthread->td_pflags |= TDP_IGNSUSP; 2200 return (0); 2201 } 2202 2203 /* 2204 * Implement kqueues for files by translating it to vnode operation. 2205 */ 2206 static int 2207 vn_kqfilter(struct file *fp, struct knote *kn) 2208 { 2209 2210 return (VOP_KQFILTER(fp->f_vnode, kn)); 2211 } 2212 2213 int 2214 vn_kqfilter_opath(struct file *fp, struct knote *kn) 2215 { 2216 if ((fp->f_flag & FKQALLOWED) == 0) 2217 return (EBADF); 2218 return (vn_kqfilter(fp, kn)); 2219 } 2220 2221 /* 2222 * Simplified in-kernel wrapper calls for extended attribute access. 2223 * Both calls pass in a NULL credential, authorizing as "kernel" access. 2224 * Set IO_NODELOCKED in ioflg if the vnode is already locked. 2225 */ 2226 int 2227 vn_extattr_get(struct vnode *vp, int ioflg, int attrnamespace, 2228 const char *attrname, int *buflen, char *buf, struct thread *td) 2229 { 2230 struct uio auio; 2231 struct iovec iov; 2232 int error; 2233 2234 iov.iov_len = *buflen; 2235 iov.iov_base = buf; 2236 2237 auio.uio_iov = &iov; 2238 auio.uio_iovcnt = 1; 2239 auio.uio_rw = UIO_READ; 2240 auio.uio_segflg = UIO_SYSSPACE; 2241 auio.uio_td = td; 2242 auio.uio_offset = 0; 2243 auio.uio_resid = *buflen; 2244 2245 if ((ioflg & IO_NODELOCKED) == 0) 2246 vn_lock(vp, LK_SHARED | LK_RETRY); 2247 2248 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 2249 2250 /* authorize attribute retrieval as kernel */ 2251 error = VOP_GETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, NULL, 2252 td); 2253 2254 if ((ioflg & IO_NODELOCKED) == 0) 2255 VOP_UNLOCK(vp); 2256 2257 if (error == 0) { 2258 *buflen = *buflen - auio.uio_resid; 2259 } 2260 2261 return (error); 2262 } 2263 2264 /* 2265 * XXX failure mode if partially written? 2266 */ 2267 int 2268 vn_extattr_set(struct vnode *vp, int ioflg, int attrnamespace, 2269 const char *attrname, int buflen, char *buf, struct thread *td) 2270 { 2271 struct uio auio; 2272 struct iovec iov; 2273 struct mount *mp; 2274 int error; 2275 2276 iov.iov_len = buflen; 2277 iov.iov_base = buf; 2278 2279 auio.uio_iov = &iov; 2280 auio.uio_iovcnt = 1; 2281 auio.uio_rw = UIO_WRITE; 2282 auio.uio_segflg = UIO_SYSSPACE; 2283 auio.uio_td = td; 2284 auio.uio_offset = 0; 2285 auio.uio_resid = buflen; 2286 2287 if ((ioflg & IO_NODELOCKED) == 0) { 2288 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) 2289 return (error); 2290 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2291 } 2292 2293 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 2294 2295 /* authorize attribute setting as kernel */ 2296 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, td); 2297 2298 if ((ioflg & IO_NODELOCKED) == 0) { 2299 vn_finished_write(mp); 2300 VOP_UNLOCK(vp); 2301 } 2302 2303 return (error); 2304 } 2305 2306 int 2307 vn_extattr_rm(struct vnode *vp, int ioflg, int attrnamespace, 2308 const char *attrname, struct thread *td) 2309 { 2310 struct mount *mp; 2311 int error; 2312 2313 if ((ioflg & IO_NODELOCKED) == 0) { 2314 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) 2315 return (error); 2316 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2317 } 2318 2319 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 2320 2321 /* authorize attribute removal as kernel */ 2322 error = VOP_DELETEEXTATTR(vp, attrnamespace, attrname, NULL, td); 2323 if (error == EOPNOTSUPP) 2324 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, NULL, 2325 NULL, td); 2326 2327 if ((ioflg & IO_NODELOCKED) == 0) { 2328 vn_finished_write(mp); 2329 VOP_UNLOCK(vp); 2330 } 2331 2332 return (error); 2333 } 2334 2335 static int 2336 vn_get_ino_alloc_vget(struct mount *mp, void *arg, int lkflags, 2337 struct vnode **rvp) 2338 { 2339 2340 return (VFS_VGET(mp, *(ino_t *)arg, lkflags, rvp)); 2341 } 2342 2343 int 2344 vn_vget_ino(struct vnode *vp, ino_t ino, int lkflags, struct vnode **rvp) 2345 { 2346 2347 return (vn_vget_ino_gen(vp, vn_get_ino_alloc_vget, &ino, 2348 lkflags, rvp)); 2349 } 2350 2351 int 2352 vn_vget_ino_gen(struct vnode *vp, vn_get_ino_t alloc, void *alloc_arg, 2353 int lkflags, struct vnode **rvp) 2354 { 2355 struct mount *mp; 2356 int ltype, error; 2357 2358 ASSERT_VOP_LOCKED(vp, "vn_vget_ino_get"); 2359 mp = vp->v_mount; 2360 ltype = VOP_ISLOCKED(vp); 2361 KASSERT(ltype == LK_EXCLUSIVE || ltype == LK_SHARED, 2362 ("vn_vget_ino: vp not locked")); 2363 error = vfs_busy(mp, MBF_NOWAIT); 2364 if (error != 0) { 2365 vfs_ref(mp); 2366 VOP_UNLOCK(vp); 2367 error = vfs_busy(mp, 0); 2368 vn_lock(vp, ltype | LK_RETRY); 2369 vfs_rel(mp); 2370 if (error != 0) 2371 return (ENOENT); 2372 if (VN_IS_DOOMED(vp)) { 2373 vfs_unbusy(mp); 2374 return (ENOENT); 2375 } 2376 } 2377 VOP_UNLOCK(vp); 2378 error = alloc(mp, alloc_arg, lkflags, rvp); 2379 vfs_unbusy(mp); 2380 if (error != 0 || *rvp != vp) 2381 vn_lock(vp, ltype | LK_RETRY); 2382 if (VN_IS_DOOMED(vp)) { 2383 if (error == 0) { 2384 if (*rvp == vp) 2385 vunref(vp); 2386 else 2387 vput(*rvp); 2388 } 2389 error = ENOENT; 2390 } 2391 return (error); 2392 } 2393 2394 static void 2395 vn_send_sigxfsz(struct proc *p) 2396 { 2397 PROC_LOCK(p); 2398 kern_psignal(p, SIGXFSZ); 2399 PROC_UNLOCK(p); 2400 } 2401 2402 int 2403 vn_rlimit_trunc(u_quad_t size, struct thread *td) 2404 { 2405 if (size <= lim_cur(td, RLIMIT_FSIZE)) 2406 return (0); 2407 vn_send_sigxfsz(td->td_proc); 2408 return (EFBIG); 2409 } 2410 2411 static int 2412 vn_rlimit_fsizex1(const struct vnode *vp, struct uio *uio, off_t maxfsz, 2413 bool adj, struct thread *td) 2414 { 2415 off_t lim; 2416 bool ktr_write; 2417 2418 if (vp->v_type != VREG) 2419 return (0); 2420 2421 /* 2422 * Handle file system maximum file size. 2423 */ 2424 if (maxfsz != 0 && uio->uio_offset + uio->uio_resid > maxfsz) { 2425 if (!adj || uio->uio_offset >= maxfsz) 2426 return (EFBIG); 2427 uio->uio_resid = maxfsz - uio->uio_offset; 2428 } 2429 2430 /* 2431 * This is kernel write (e.g. vnode_pager) or accounting 2432 * write, ignore limit. 2433 */ 2434 if (td == NULL || (td->td_pflags2 & TDP2_ACCT) != 0) 2435 return (0); 2436 2437 /* 2438 * Calculate file size limit. 2439 */ 2440 ktr_write = (td->td_pflags & TDP_INKTRACE) != 0; 2441 lim = __predict_false(ktr_write) ? td->td_ktr_io_lim : 2442 lim_cur(td, RLIMIT_FSIZE); 2443 2444 /* 2445 * Is the limit reached? 2446 */ 2447 if (__predict_true((uoff_t)uio->uio_offset + uio->uio_resid <= lim)) 2448 return (0); 2449 2450 /* 2451 * Prepared filesystems can handle writes truncated to the 2452 * file size limit. 2453 */ 2454 if (adj && (uoff_t)uio->uio_offset < lim) { 2455 uio->uio_resid = lim - (uoff_t)uio->uio_offset; 2456 return (0); 2457 } 2458 2459 if (!ktr_write || ktr_filesize_limit_signal) 2460 vn_send_sigxfsz(td->td_proc); 2461 return (EFBIG); 2462 } 2463 2464 /* 2465 * Helper for VOP_WRITE() implementations, the common code to 2466 * handle maximum supported file size on the filesystem, and 2467 * RLIMIT_FSIZE, except for special writes from accounting subsystem 2468 * and ktrace. 2469 * 2470 * For maximum file size (maxfsz argument): 2471 * - return EFBIG if uio_offset is beyond it 2472 * - otherwise, clamp uio_resid if write would extend file beyond maxfsz. 2473 * 2474 * For RLIMIT_FSIZE: 2475 * - return EFBIG and send SIGXFSZ if uio_offset is beyond the limit 2476 * - otherwise, clamp uio_resid if write would extend file beyond limit. 2477 * 2478 * If clamping occured, the adjustment for uio_resid is stored in 2479 * *resid_adj, to be re-applied by vn_rlimit_fsizex_res() on return 2480 * from the VOP. 2481 */ 2482 int 2483 vn_rlimit_fsizex(const struct vnode *vp, struct uio *uio, off_t maxfsz, 2484 ssize_t *resid_adj, struct thread *td) 2485 { 2486 ssize_t resid_orig; 2487 int error; 2488 bool adj; 2489 2490 resid_orig = uio->uio_resid; 2491 adj = resid_adj != NULL; 2492 error = vn_rlimit_fsizex1(vp, uio, maxfsz, adj, td); 2493 if (adj) 2494 *resid_adj = resid_orig - uio->uio_resid; 2495 return (error); 2496 } 2497 2498 void 2499 vn_rlimit_fsizex_res(struct uio *uio, ssize_t resid_adj) 2500 { 2501 uio->uio_resid += resid_adj; 2502 } 2503 2504 int 2505 vn_rlimit_fsize(const struct vnode *vp, const struct uio *uio, 2506 struct thread *td) 2507 { 2508 return (vn_rlimit_fsizex(vp, __DECONST(struct uio *, uio), 0, NULL, 2509 td)); 2510 } 2511 2512 int 2513 vn_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 2514 struct thread *td) 2515 { 2516 struct vnode *vp; 2517 2518 vp = fp->f_vnode; 2519 #ifdef AUDIT 2520 vn_lock(vp, LK_SHARED | LK_RETRY); 2521 AUDIT_ARG_VNODE1(vp); 2522 VOP_UNLOCK(vp); 2523 #endif 2524 return (setfmode(td, active_cred, vp, mode)); 2525 } 2526 2527 int 2528 vn_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 2529 struct thread *td) 2530 { 2531 struct vnode *vp; 2532 2533 vp = fp->f_vnode; 2534 #ifdef AUDIT 2535 vn_lock(vp, LK_SHARED | LK_RETRY); 2536 AUDIT_ARG_VNODE1(vp); 2537 VOP_UNLOCK(vp); 2538 #endif 2539 return (setfown(td, active_cred, vp, uid, gid)); 2540 } 2541 2542 /* 2543 * Remove pages in the range ["start", "end") from the vnode's VM object. If 2544 * "end" is 0, then the range extends to the end of the object. 2545 */ 2546 void 2547 vn_pages_remove(struct vnode *vp, vm_pindex_t start, vm_pindex_t end) 2548 { 2549 vm_object_t object; 2550 2551 if ((object = vp->v_object) == NULL) 2552 return; 2553 VM_OBJECT_WLOCK(object); 2554 vm_object_page_remove(object, start, end, 0); 2555 VM_OBJECT_WUNLOCK(object); 2556 } 2557 2558 /* 2559 * Like vn_pages_remove(), but skips invalid pages, which by definition are not 2560 * mapped into any process' address space. Filesystems may use this in 2561 * preference to vn_pages_remove() to avoid blocking on pages busied in 2562 * preparation for a VOP_GETPAGES. 2563 */ 2564 void 2565 vn_pages_remove_valid(struct vnode *vp, vm_pindex_t start, vm_pindex_t end) 2566 { 2567 vm_object_t object; 2568 2569 if ((object = vp->v_object) == NULL) 2570 return; 2571 VM_OBJECT_WLOCK(object); 2572 vm_object_page_remove(object, start, end, OBJPR_VALIDONLY); 2573 VM_OBJECT_WUNLOCK(object); 2574 } 2575 2576 int 2577 vn_bmap_seekhole_locked(struct vnode *vp, u_long cmd, off_t *off, 2578 struct ucred *cred) 2579 { 2580 off_t size; 2581 daddr_t bn, bnp; 2582 uint64_t bsize; 2583 off_t noff; 2584 int error; 2585 2586 KASSERT(cmd == FIOSEEKHOLE || cmd == FIOSEEKDATA, 2587 ("%s: Wrong command %lu", __func__, cmd)); 2588 ASSERT_VOP_ELOCKED(vp, "vn_bmap_seekhole_locked"); 2589 2590 if (vp->v_type != VREG) { 2591 error = ENOTTY; 2592 goto out; 2593 } 2594 error = vn_getsize_locked(vp, &size, cred); 2595 if (error != 0) 2596 goto out; 2597 noff = *off; 2598 if (noff < 0 || noff >= size) { 2599 error = ENXIO; 2600 goto out; 2601 } 2602 2603 /* See the comment in ufs_bmap_seekdata(). */ 2604 vnode_pager_clean_sync(vp); 2605 2606 bsize = vp->v_mount->mnt_stat.f_iosize; 2607 for (bn = noff / bsize; noff < size; bn++, noff += bsize - 2608 noff % bsize) { 2609 error = VOP_BMAP(vp, bn, NULL, &bnp, NULL, NULL); 2610 if (error == EOPNOTSUPP) { 2611 error = ENOTTY; 2612 goto out; 2613 } 2614 if ((bnp == -1 && cmd == FIOSEEKHOLE) || 2615 (bnp != -1 && cmd == FIOSEEKDATA)) { 2616 noff = bn * bsize; 2617 if (noff < *off) 2618 noff = *off; 2619 goto out; 2620 } 2621 } 2622 if (noff > size) 2623 noff = size; 2624 /* noff == size. There is an implicit hole at the end of file. */ 2625 if (cmd == FIOSEEKDATA) 2626 error = ENXIO; 2627 out: 2628 if (error == 0) 2629 *off = noff; 2630 return (error); 2631 } 2632 2633 int 2634 vn_bmap_seekhole(struct vnode *vp, u_long cmd, off_t *off, struct ucred *cred) 2635 { 2636 int error; 2637 2638 KASSERT(cmd == FIOSEEKHOLE || cmd == FIOSEEKDATA, 2639 ("%s: Wrong command %lu", __func__, cmd)); 2640 2641 if (vn_lock(vp, LK_EXCLUSIVE) != 0) 2642 return (EBADF); 2643 error = vn_bmap_seekhole_locked(vp, cmd, off, cred); 2644 VOP_UNLOCK(vp); 2645 return (error); 2646 } 2647 2648 int 2649 vn_seek(struct file *fp, off_t offset, int whence, struct thread *td) 2650 { 2651 struct ucred *cred; 2652 struct vnode *vp; 2653 off_t foffset, fsize, size; 2654 int error, noneg; 2655 2656 cred = td->td_ucred; 2657 vp = fp->f_vnode; 2658 noneg = (vp->v_type != VCHR); 2659 /* 2660 * Try to dodge locking for common case of querying the offset. 2661 */ 2662 if (whence == L_INCR && offset == 0) { 2663 foffset = foffset_read(fp); 2664 if (__predict_false(foffset < 0 && noneg)) { 2665 return (EOVERFLOW); 2666 } 2667 td->td_uretoff.tdu_off = foffset; 2668 return (0); 2669 } 2670 foffset = foffset_lock(fp, 0); 2671 error = 0; 2672 switch (whence) { 2673 case L_INCR: 2674 if (noneg && 2675 (foffset < 0 || 2676 (offset > 0 && foffset > OFF_MAX - offset))) { 2677 error = EOVERFLOW; 2678 break; 2679 } 2680 offset += foffset; 2681 break; 2682 case L_XTND: 2683 error = vn_getsize(vp, &fsize, cred); 2684 if (error != 0) 2685 break; 2686 2687 /* 2688 * If the file references a disk device, then fetch 2689 * the media size and use that to determine the ending 2690 * offset. 2691 */ 2692 if (fsize == 0 && vp->v_type == VCHR && 2693 fo_ioctl(fp, DIOCGMEDIASIZE, &size, cred, td) == 0) 2694 fsize = size; 2695 if (noneg && offset > 0 && fsize > OFF_MAX - offset) { 2696 error = EOVERFLOW; 2697 break; 2698 } 2699 offset += fsize; 2700 break; 2701 case L_SET: 2702 break; 2703 case SEEK_DATA: 2704 error = fo_ioctl(fp, FIOSEEKDATA, &offset, cred, td); 2705 if (error == ENOTTY) 2706 error = EINVAL; 2707 break; 2708 case SEEK_HOLE: 2709 error = fo_ioctl(fp, FIOSEEKHOLE, &offset, cred, td); 2710 if (error == ENOTTY) 2711 error = EINVAL; 2712 break; 2713 default: 2714 error = EINVAL; 2715 } 2716 if (error == 0 && noneg && offset < 0) 2717 error = EINVAL; 2718 if (error != 0) 2719 goto drop; 2720 VFS_KNOTE_UNLOCKED(vp, 0); 2721 td->td_uretoff.tdu_off = offset; 2722 drop: 2723 foffset_unlock(fp, offset, error != 0 ? FOF_NOUPDATE : 0); 2724 return (error); 2725 } 2726 2727 int 2728 vn_utimes_perm(struct vnode *vp, struct vattr *vap, struct ucred *cred, 2729 struct thread *td) 2730 { 2731 int error; 2732 2733 /* 2734 * Grant permission if the caller is the owner of the file, or 2735 * the super-user, or has ACL_WRITE_ATTRIBUTES permission on 2736 * on the file. If the time pointer is null, then write 2737 * permission on the file is also sufficient. 2738 * 2739 * From NFSv4.1, draft 21, 6.2.1.3.1, Discussion of Mask Attributes: 2740 * A user having ACL_WRITE_DATA or ACL_WRITE_ATTRIBUTES 2741 * will be allowed to set the times [..] to the current 2742 * server time. 2743 */ 2744 error = VOP_ACCESSX(vp, VWRITE_ATTRIBUTES, cred, td); 2745 if (error != 0 && (vap->va_vaflags & VA_UTIMES_NULL) != 0) 2746 error = VOP_ACCESS(vp, VWRITE, cred, td); 2747 return (error); 2748 } 2749 2750 int 2751 vn_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 2752 { 2753 struct vnode *vp; 2754 int error; 2755 2756 if (fp->f_type == DTYPE_FIFO) 2757 kif->kf_type = KF_TYPE_FIFO; 2758 else 2759 kif->kf_type = KF_TYPE_VNODE; 2760 vp = fp->f_vnode; 2761 vref(vp); 2762 FILEDESC_SUNLOCK(fdp); 2763 error = vn_fill_kinfo_vnode(vp, kif); 2764 vrele(vp); 2765 FILEDESC_SLOCK(fdp); 2766 return (error); 2767 } 2768 2769 static inline void 2770 vn_fill_junk(struct kinfo_file *kif) 2771 { 2772 size_t len, olen; 2773 2774 /* 2775 * Simulate vn_fullpath returning changing values for a given 2776 * vp during e.g. coredump. 2777 */ 2778 len = (arc4random() % (sizeof(kif->kf_path) - 2)) + 1; 2779 olen = strlen(kif->kf_path); 2780 if (len < olen) 2781 strcpy(&kif->kf_path[len - 1], "$"); 2782 else 2783 for (; olen < len; olen++) 2784 strcpy(&kif->kf_path[olen], "A"); 2785 } 2786 2787 int 2788 vn_fill_kinfo_vnode(struct vnode *vp, struct kinfo_file *kif) 2789 { 2790 struct vattr va; 2791 char *fullpath, *freepath; 2792 int error; 2793 2794 kif->kf_un.kf_file.kf_file_type = vntype_to_kinfo(vp->v_type); 2795 freepath = NULL; 2796 fullpath = "-"; 2797 error = vn_fullpath(vp, &fullpath, &freepath); 2798 if (error == 0) { 2799 strlcpy(kif->kf_path, fullpath, sizeof(kif->kf_path)); 2800 } 2801 if (freepath != NULL) 2802 free(freepath, M_TEMP); 2803 2804 KFAIL_POINT_CODE(DEBUG_FP, fill_kinfo_vnode__random_path, 2805 vn_fill_junk(kif); 2806 ); 2807 2808 /* 2809 * Retrieve vnode attributes. 2810 */ 2811 va.va_fsid = VNOVAL; 2812 va.va_rdev = NODEV; 2813 vn_lock(vp, LK_SHARED | LK_RETRY); 2814 error = VOP_GETATTR(vp, &va, curthread->td_ucred); 2815 VOP_UNLOCK(vp); 2816 if (error != 0) 2817 return (error); 2818 if (va.va_fsid != VNOVAL) 2819 kif->kf_un.kf_file.kf_file_fsid = va.va_fsid; 2820 else 2821 kif->kf_un.kf_file.kf_file_fsid = 2822 vp->v_mount->mnt_stat.f_fsid.val[0]; 2823 kif->kf_un.kf_file.kf_file_fsid_freebsd11 = 2824 kif->kf_un.kf_file.kf_file_fsid; /* truncate */ 2825 kif->kf_un.kf_file.kf_file_fileid = va.va_fileid; 2826 kif->kf_un.kf_file.kf_file_mode = MAKEIMODE(va.va_type, va.va_mode); 2827 kif->kf_un.kf_file.kf_file_size = va.va_size; 2828 kif->kf_un.kf_file.kf_file_rdev = va.va_rdev; 2829 kif->kf_un.kf_file.kf_file_rdev_freebsd11 = 2830 kif->kf_un.kf_file.kf_file_rdev; /* truncate */ 2831 kif->kf_un.kf_file.kf_file_nlink = va.va_nlink; 2832 return (0); 2833 } 2834 2835 int 2836 vn_mmap(struct file *fp, vm_map_t map, vm_offset_t *addr, vm_size_t size, 2837 vm_prot_t prot, vm_prot_t cap_maxprot, int flags, vm_ooffset_t foff, 2838 struct thread *td) 2839 { 2840 #ifdef HWPMC_HOOKS 2841 struct pmckern_map_in pkm; 2842 #endif 2843 struct mount *mp; 2844 struct vnode *vp; 2845 vm_object_t object; 2846 vm_prot_t maxprot; 2847 boolean_t writecounted; 2848 int error; 2849 2850 #if defined(COMPAT_FREEBSD7) || defined(COMPAT_FREEBSD6) || \ 2851 defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4) 2852 /* 2853 * POSIX shared-memory objects are defined to have 2854 * kernel persistence, and are not defined to support 2855 * read(2)/write(2) -- or even open(2). Thus, we can 2856 * use MAP_ASYNC to trade on-disk coherence for speed. 2857 * The shm_open(3) library routine turns on the FPOSIXSHM 2858 * flag to request this behavior. 2859 */ 2860 if ((fp->f_flag & FPOSIXSHM) != 0) 2861 flags |= MAP_NOSYNC; 2862 #endif 2863 vp = fp->f_vnode; 2864 2865 /* 2866 * Ensure that file and memory protections are 2867 * compatible. Note that we only worry about 2868 * writability if mapping is shared; in this case, 2869 * current and max prot are dictated by the open file. 2870 * XXX use the vnode instead? Problem is: what 2871 * credentials do we use for determination? What if 2872 * proc does a setuid? 2873 */ 2874 mp = vp->v_mount; 2875 if (mp != NULL && (mp->mnt_flag & MNT_NOEXEC) != 0) { 2876 maxprot = VM_PROT_NONE; 2877 if ((prot & VM_PROT_EXECUTE) != 0) 2878 return (EACCES); 2879 } else 2880 maxprot = VM_PROT_EXECUTE; 2881 if ((fp->f_flag & FREAD) != 0) 2882 maxprot |= VM_PROT_READ; 2883 else if ((prot & VM_PROT_READ) != 0) 2884 return (EACCES); 2885 2886 /* 2887 * If we are sharing potential changes via MAP_SHARED and we 2888 * are trying to get write permission although we opened it 2889 * without asking for it, bail out. 2890 */ 2891 if ((flags & MAP_SHARED) != 0) { 2892 if ((fp->f_flag & FWRITE) != 0) 2893 maxprot |= VM_PROT_WRITE; 2894 else if ((prot & VM_PROT_WRITE) != 0) 2895 return (EACCES); 2896 } else { 2897 maxprot |= VM_PROT_WRITE; 2898 cap_maxprot |= VM_PROT_WRITE; 2899 } 2900 maxprot &= cap_maxprot; 2901 2902 /* 2903 * For regular files and shared memory, POSIX requires that 2904 * the value of foff be a legitimate offset within the data 2905 * object. In particular, negative offsets are invalid. 2906 * Blocking negative offsets and overflows here avoids 2907 * possible wraparound or user-level access into reserved 2908 * ranges of the data object later. In contrast, POSIX does 2909 * not dictate how offsets are used by device drivers, so in 2910 * the case of a device mapping a negative offset is passed 2911 * on. 2912 */ 2913 if ( 2914 #ifdef _LP64 2915 size > OFF_MAX || 2916 #endif 2917 foff > OFF_MAX - size) 2918 return (EINVAL); 2919 2920 writecounted = FALSE; 2921 error = vm_mmap_vnode(td, size, prot, &maxprot, &flags, vp, 2922 &foff, &object, &writecounted); 2923 if (error != 0) 2924 return (error); 2925 error = vm_mmap_object(map, addr, size, prot, maxprot, flags, object, 2926 foff, writecounted, td); 2927 if (error != 0) { 2928 /* 2929 * If this mapping was accounted for in the vnode's 2930 * writecount, then undo that now. 2931 */ 2932 if (writecounted) 2933 vm_pager_release_writecount(object, 0, size); 2934 vm_object_deallocate(object); 2935 } 2936 #ifdef HWPMC_HOOKS 2937 /* Inform hwpmc(4) if an executable is being mapped. */ 2938 if (PMC_HOOK_INSTALLED(PMC_FN_MMAP)) { 2939 if ((prot & VM_PROT_EXECUTE) != 0 && error == 0) { 2940 pkm.pm_file = vp; 2941 pkm.pm_address = (uintptr_t) *addr; 2942 PMC_CALL_HOOK_UNLOCKED(td, PMC_FN_MMAP, (void *) &pkm); 2943 } 2944 } 2945 #endif 2946 return (error); 2947 } 2948 2949 void 2950 vn_fsid(struct vnode *vp, struct vattr *va) 2951 { 2952 fsid_t *f; 2953 2954 f = &vp->v_mount->mnt_stat.f_fsid; 2955 va->va_fsid = (uint32_t)f->val[1]; 2956 va->va_fsid <<= sizeof(f->val[1]) * NBBY; 2957 va->va_fsid += (uint32_t)f->val[0]; 2958 } 2959 2960 int 2961 vn_fsync_buf(struct vnode *vp, int waitfor) 2962 { 2963 struct buf *bp, *nbp; 2964 struct bufobj *bo; 2965 struct mount *mp; 2966 int error, maxretry; 2967 2968 error = 0; 2969 maxretry = 10000; /* large, arbitrarily chosen */ 2970 mp = NULL; 2971 if (vp->v_type == VCHR) { 2972 VI_LOCK(vp); 2973 mp = vp->v_rdev->si_mountpt; 2974 VI_UNLOCK(vp); 2975 } 2976 bo = &vp->v_bufobj; 2977 BO_LOCK(bo); 2978 loop1: 2979 /* 2980 * MARK/SCAN initialization to avoid infinite loops. 2981 */ 2982 TAILQ_FOREACH(bp, &bo->bo_dirty.bv_hd, b_bobufs) { 2983 bp->b_vflags &= ~BV_SCANNED; 2984 bp->b_error = 0; 2985 } 2986 2987 /* 2988 * Flush all dirty buffers associated with a vnode. 2989 */ 2990 loop2: 2991 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 2992 if ((bp->b_vflags & BV_SCANNED) != 0) 2993 continue; 2994 bp->b_vflags |= BV_SCANNED; 2995 if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT, NULL)) { 2996 if (waitfor != MNT_WAIT) 2997 continue; 2998 if (BUF_LOCK(bp, 2999 LK_EXCLUSIVE | LK_INTERLOCK | LK_SLEEPFAIL, 3000 BO_LOCKPTR(bo)) != 0) { 3001 BO_LOCK(bo); 3002 goto loop1; 3003 } 3004 BO_LOCK(bo); 3005 } 3006 BO_UNLOCK(bo); 3007 KASSERT(bp->b_bufobj == bo, 3008 ("bp %p wrong b_bufobj %p should be %p", 3009 bp, bp->b_bufobj, bo)); 3010 if ((bp->b_flags & B_DELWRI) == 0) 3011 panic("fsync: not dirty"); 3012 if ((vp->v_object != NULL) && (bp->b_flags & B_CLUSTEROK)) { 3013 vfs_bio_awrite(bp); 3014 } else { 3015 bremfree(bp); 3016 bawrite(bp); 3017 } 3018 if (maxretry < 1000) 3019 pause("dirty", hz < 1000 ? 1 : hz / 1000); 3020 BO_LOCK(bo); 3021 goto loop2; 3022 } 3023 3024 /* 3025 * If synchronous the caller expects us to completely resolve all 3026 * dirty buffers in the system. Wait for in-progress I/O to 3027 * complete (which could include background bitmap writes), then 3028 * retry if dirty blocks still exist. 3029 */ 3030 if (waitfor == MNT_WAIT) { 3031 bufobj_wwait(bo, 0, 0); 3032 if (bo->bo_dirty.bv_cnt > 0) { 3033 /* 3034 * If we are unable to write any of these buffers 3035 * then we fail now rather than trying endlessly 3036 * to write them out. 3037 */ 3038 TAILQ_FOREACH(bp, &bo->bo_dirty.bv_hd, b_bobufs) 3039 if ((error = bp->b_error) != 0) 3040 break; 3041 if ((mp != NULL && mp->mnt_secondary_writes > 0) || 3042 (error == 0 && --maxretry >= 0)) 3043 goto loop1; 3044 if (error == 0) 3045 error = EAGAIN; 3046 } 3047 } 3048 BO_UNLOCK(bo); 3049 if (error != 0) 3050 vn_printf(vp, "fsync: giving up on dirty (error = %d) ", error); 3051 3052 return (error); 3053 } 3054 3055 /* 3056 * Copies a byte range from invp to outvp. Calls VOP_COPY_FILE_RANGE() 3057 * or vn_generic_copy_file_range() after rangelocking the byte ranges, 3058 * to do the actual copy. 3059 * vn_generic_copy_file_range() is factored out, so it can be called 3060 * from a VOP_COPY_FILE_RANGE() call as well, but handles vnodes from 3061 * different file systems. 3062 */ 3063 int 3064 vn_copy_file_range(struct vnode *invp, off_t *inoffp, struct vnode *outvp, 3065 off_t *outoffp, size_t *lenp, unsigned int flags, struct ucred *incred, 3066 struct ucred *outcred, struct thread *fsize_td) 3067 { 3068 struct mount *inmp, *outmp; 3069 struct vnode *invpl, *outvpl; 3070 int error; 3071 size_t len; 3072 uint64_t uval; 3073 3074 invpl = outvpl = NULL; 3075 len = *lenp; 3076 *lenp = 0; /* For error returns. */ 3077 error = 0; 3078 3079 /* Do some sanity checks on the arguments. */ 3080 if (invp->v_type == VDIR || outvp->v_type == VDIR) 3081 error = EISDIR; 3082 else if (*inoffp < 0 || *outoffp < 0 || 3083 invp->v_type != VREG || outvp->v_type != VREG) 3084 error = EINVAL; 3085 if (error != 0) 3086 goto out; 3087 3088 /* Ensure offset + len does not wrap around. */ 3089 uval = *inoffp; 3090 uval += len; 3091 if (uval > INT64_MAX) 3092 len = INT64_MAX - *inoffp; 3093 uval = *outoffp; 3094 uval += len; 3095 if (uval > INT64_MAX) 3096 len = INT64_MAX - *outoffp; 3097 if (len == 0) 3098 goto out; 3099 3100 error = VOP_GETLOWVNODE(invp, &invpl, FREAD); 3101 if (error != 0) 3102 goto out; 3103 error = VOP_GETLOWVNODE(outvp, &outvpl, FWRITE); 3104 if (error != 0) 3105 goto out1; 3106 3107 inmp = invpl->v_mount; 3108 outmp = outvpl->v_mount; 3109 if (inmp == NULL || outmp == NULL) 3110 goto out2; 3111 3112 for (;;) { 3113 error = vfs_busy(inmp, 0); 3114 if (error != 0) 3115 goto out2; 3116 if (inmp == outmp) 3117 break; 3118 error = vfs_busy(outmp, MBF_NOWAIT); 3119 if (error != 0) { 3120 vfs_unbusy(inmp); 3121 error = vfs_busy(outmp, 0); 3122 if (error == 0) { 3123 vfs_unbusy(outmp); 3124 continue; 3125 } 3126 goto out2; 3127 } 3128 break; 3129 } 3130 3131 /* 3132 * If the two vnodes are for the same file system type, call 3133 * VOP_COPY_FILE_RANGE(), otherwise call vn_generic_copy_file_range() 3134 * which can handle copies across multiple file system types. 3135 */ 3136 *lenp = len; 3137 if (inmp == outmp || inmp->mnt_vfc == outmp->mnt_vfc) 3138 error = VOP_COPY_FILE_RANGE(invpl, inoffp, outvpl, outoffp, 3139 lenp, flags, incred, outcred, fsize_td); 3140 else 3141 error = ENOSYS; 3142 if (error == ENOSYS) 3143 error = vn_generic_copy_file_range(invpl, inoffp, outvpl, 3144 outoffp, lenp, flags, incred, outcred, fsize_td); 3145 vfs_unbusy(outmp); 3146 if (inmp != outmp) 3147 vfs_unbusy(inmp); 3148 out2: 3149 if (outvpl != NULL) 3150 vrele(outvpl); 3151 out1: 3152 if (invpl != NULL) 3153 vrele(invpl); 3154 out: 3155 return (error); 3156 } 3157 3158 /* 3159 * Test len bytes of data starting at dat for all bytes == 0. 3160 * Return true if all bytes are zero, false otherwise. 3161 * Expects dat to be well aligned. 3162 */ 3163 static bool 3164 mem_iszero(void *dat, int len) 3165 { 3166 int i; 3167 const u_int *p; 3168 const char *cp; 3169 3170 for (p = dat; len > 0; len -= sizeof(*p), p++) { 3171 if (len >= sizeof(*p)) { 3172 if (*p != 0) 3173 return (false); 3174 } else { 3175 cp = (const char *)p; 3176 for (i = 0; i < len; i++, cp++) 3177 if (*cp != '\0') 3178 return (false); 3179 } 3180 } 3181 return (true); 3182 } 3183 3184 /* 3185 * Look for a hole in the output file and, if found, adjust *outoffp 3186 * and *xferp to skip past the hole. 3187 * *xferp is the entire hole length to be written and xfer2 is how many bytes 3188 * to be written as 0's upon return. 3189 */ 3190 static off_t 3191 vn_skip_hole(struct vnode *outvp, off_t xfer2, off_t *outoffp, off_t *xferp, 3192 off_t *dataoffp, off_t *holeoffp, struct ucred *cred) 3193 { 3194 int error; 3195 off_t delta; 3196 3197 if (*holeoffp == 0 || *holeoffp <= *outoffp) { 3198 *dataoffp = *outoffp; 3199 error = VOP_IOCTL(outvp, FIOSEEKDATA, dataoffp, 0, cred, 3200 curthread); 3201 if (error == 0) { 3202 *holeoffp = *dataoffp; 3203 error = VOP_IOCTL(outvp, FIOSEEKHOLE, holeoffp, 0, cred, 3204 curthread); 3205 } 3206 if (error != 0 || *holeoffp == *dataoffp) { 3207 /* 3208 * Since outvp is unlocked, it may be possible for 3209 * another thread to do a truncate(), lseek(), write() 3210 * creating a hole at startoff between the above 3211 * VOP_IOCTL() calls, if the other thread does not do 3212 * rangelocking. 3213 * If that happens, *holeoffp == *dataoffp and finding 3214 * the hole has failed, so disable vn_skip_hole(). 3215 */ 3216 *holeoffp = -1; /* Disable use of vn_skip_hole(). */ 3217 return (xfer2); 3218 } 3219 KASSERT(*dataoffp >= *outoffp, 3220 ("vn_skip_hole: dataoff=%jd < outoff=%jd", 3221 (intmax_t)*dataoffp, (intmax_t)*outoffp)); 3222 KASSERT(*holeoffp > *dataoffp, 3223 ("vn_skip_hole: holeoff=%jd <= dataoff=%jd", 3224 (intmax_t)*holeoffp, (intmax_t)*dataoffp)); 3225 } 3226 3227 /* 3228 * If there is a hole before the data starts, advance *outoffp and 3229 * *xferp past the hole. 3230 */ 3231 if (*dataoffp > *outoffp) { 3232 delta = *dataoffp - *outoffp; 3233 if (delta >= *xferp) { 3234 /* Entire *xferp is a hole. */ 3235 *outoffp += *xferp; 3236 *xferp = 0; 3237 return (0); 3238 } 3239 *xferp -= delta; 3240 *outoffp += delta; 3241 xfer2 = MIN(xfer2, *xferp); 3242 } 3243 3244 /* 3245 * If a hole starts before the end of this xfer2, reduce this xfer2 so 3246 * that the write ends at the start of the hole. 3247 * *holeoffp should always be greater than *outoffp, but for the 3248 * non-INVARIANTS case, check this to make sure xfer2 remains a sane 3249 * value. 3250 */ 3251 if (*holeoffp > *outoffp && *holeoffp < *outoffp + xfer2) 3252 xfer2 = *holeoffp - *outoffp; 3253 return (xfer2); 3254 } 3255 3256 /* 3257 * Write an xfer sized chunk to outvp in blksize blocks from dat. 3258 * dat is a maximum of blksize in length and can be written repeatedly in 3259 * the chunk. 3260 * If growfile == true, just grow the file via vn_truncate_locked() instead 3261 * of doing actual writes. 3262 * If checkhole == true, a hole is being punched, so skip over any hole 3263 * already in the output file. 3264 */ 3265 static int 3266 vn_write_outvp(struct vnode *outvp, char *dat, off_t outoff, off_t xfer, 3267 u_long blksize, bool growfile, bool checkhole, struct ucred *cred) 3268 { 3269 struct mount *mp; 3270 off_t dataoff, holeoff, xfer2; 3271 int error; 3272 3273 /* 3274 * Loop around doing writes of blksize until write has been completed. 3275 * Lock/unlock on each loop iteration so that a bwillwrite() can be 3276 * done for each iteration, since the xfer argument can be very 3277 * large if there is a large hole to punch in the output file. 3278 */ 3279 error = 0; 3280 holeoff = 0; 3281 do { 3282 xfer2 = MIN(xfer, blksize); 3283 if (checkhole) { 3284 /* 3285 * Punching a hole. Skip writing if there is 3286 * already a hole in the output file. 3287 */ 3288 xfer2 = vn_skip_hole(outvp, xfer2, &outoff, &xfer, 3289 &dataoff, &holeoff, cred); 3290 if (xfer == 0) 3291 break; 3292 if (holeoff < 0) 3293 checkhole = false; 3294 KASSERT(xfer2 > 0, ("vn_write_outvp: xfer2=%jd", 3295 (intmax_t)xfer2)); 3296 } 3297 bwillwrite(); 3298 mp = NULL; 3299 error = vn_start_write(outvp, &mp, V_WAIT); 3300 if (error != 0) 3301 break; 3302 if (growfile) { 3303 error = vn_lock(outvp, LK_EXCLUSIVE); 3304 if (error == 0) { 3305 error = vn_truncate_locked(outvp, outoff + xfer, 3306 false, cred); 3307 VOP_UNLOCK(outvp); 3308 } 3309 } else { 3310 error = vn_lock(outvp, vn_lktype_write(mp, outvp)); 3311 if (error == 0) { 3312 error = vn_rdwr(UIO_WRITE, outvp, dat, xfer2, 3313 outoff, UIO_SYSSPACE, IO_NODELOCKED, 3314 curthread->td_ucred, cred, NULL, curthread); 3315 outoff += xfer2; 3316 xfer -= xfer2; 3317 VOP_UNLOCK(outvp); 3318 } 3319 } 3320 if (mp != NULL) 3321 vn_finished_write(mp); 3322 } while (!growfile && xfer > 0 && error == 0); 3323 return (error); 3324 } 3325 3326 /* 3327 * Copy a byte range of one file to another. This function can handle the 3328 * case where invp and outvp are on different file systems. 3329 * It can also be called by a VOP_COPY_FILE_RANGE() to do the work, if there 3330 * is no better file system specific way to do it. 3331 */ 3332 int 3333 vn_generic_copy_file_range(struct vnode *invp, off_t *inoffp, 3334 struct vnode *outvp, off_t *outoffp, size_t *lenp, unsigned int flags, 3335 struct ucred *incred, struct ucred *outcred, struct thread *fsize_td) 3336 { 3337 struct vattr inva; 3338 struct mount *mp; 3339 off_t startoff, endoff, xfer, xfer2; 3340 u_long blksize; 3341 int error, interrupted; 3342 bool cantseek, readzeros, eof, lastblock, holetoeof, sparse; 3343 ssize_t aresid, r = 0; 3344 size_t copylen, len, savlen; 3345 off_t outsize; 3346 char *dat; 3347 long holein, holeout; 3348 struct timespec curts, endts; 3349 3350 holein = holeout = 0; 3351 savlen = len = *lenp; 3352 error = 0; 3353 interrupted = 0; 3354 dat = NULL; 3355 3356 error = vn_lock(invp, LK_SHARED); 3357 if (error != 0) 3358 goto out; 3359 if (VOP_PATHCONF(invp, _PC_MIN_HOLE_SIZE, &holein) != 0) 3360 holein = 0; 3361 error = VOP_GETATTR(invp, &inva, incred); 3362 if (error == 0 && inva.va_size > OFF_MAX) 3363 error = EFBIG; 3364 VOP_UNLOCK(invp); 3365 if (error != 0) 3366 goto out; 3367 3368 /* 3369 * Use va_bytes >= va_size as a hint that the file does not have 3370 * sufficient holes to justify the overhead of doing FIOSEEKHOLE. 3371 * This hint does not work well for file systems doing compression 3372 * and may fail when allocations for extended attributes increases 3373 * the value of va_bytes to >= va_size. 3374 */ 3375 sparse = true; 3376 if (holein != 0 && inva.va_bytes >= inva.va_size) { 3377 holein = 0; 3378 sparse = false; 3379 } 3380 3381 mp = NULL; 3382 error = vn_start_write(outvp, &mp, V_WAIT); 3383 if (error == 0) 3384 error = vn_lock(outvp, LK_EXCLUSIVE); 3385 if (error == 0) { 3386 /* 3387 * If fsize_td != NULL, do a vn_rlimit_fsizex() call, 3388 * now that outvp is locked. 3389 */ 3390 if (fsize_td != NULL) { 3391 struct uio io; 3392 3393 io.uio_offset = *outoffp; 3394 io.uio_resid = len; 3395 error = vn_rlimit_fsizex(outvp, &io, 0, &r, fsize_td); 3396 len = savlen = io.uio_resid; 3397 /* 3398 * No need to call vn_rlimit_fsizex_res before return, 3399 * since the uio is local. 3400 */ 3401 } 3402 if (VOP_PATHCONF(outvp, _PC_MIN_HOLE_SIZE, &holeout) != 0) 3403 holeout = 0; 3404 /* 3405 * Holes that are past EOF do not need to be written as a block 3406 * of zero bytes. So, truncate the output file as far as 3407 * possible and then use size to decide if writing 0 3408 * bytes is necessary in the loop below. 3409 */ 3410 if (error == 0) 3411 error = vn_getsize_locked(outvp, &outsize, outcred); 3412 if (error == 0 && outsize > *outoffp && 3413 *outoffp <= OFF_MAX - len && outsize <= *outoffp + len && 3414 *inoffp < inva.va_size && 3415 *outoffp <= OFF_MAX - (inva.va_size - *inoffp) && 3416 outsize <= *outoffp + (inva.va_size - *inoffp)) { 3417 #ifdef MAC 3418 error = mac_vnode_check_write(curthread->td_ucred, 3419 outcred, outvp); 3420 if (error == 0) 3421 #endif 3422 error = vn_truncate_locked(outvp, *outoffp, 3423 false, outcred); 3424 if (error == 0) 3425 outsize = *outoffp; 3426 } 3427 VOP_UNLOCK(outvp); 3428 } 3429 if (mp != NULL) 3430 vn_finished_write(mp); 3431 if (error != 0) 3432 goto out; 3433 3434 if (sparse && holein == 0 && holeout > 0) { 3435 /* 3436 * For this special case, the input data will be scanned 3437 * for blocks of all 0 bytes. For these blocks, the 3438 * write can be skipped for the output file to create 3439 * an unallocated region. 3440 * Therefore, use the appropriate size for the output file. 3441 */ 3442 blksize = holeout; 3443 if (blksize <= 512) { 3444 /* 3445 * Use f_iosize, since ZFS reports a _PC_MIN_HOLE_SIZE 3446 * of 512, although it actually only creates 3447 * unallocated regions for blocks >= f_iosize. 3448 */ 3449 blksize = outvp->v_mount->mnt_stat.f_iosize; 3450 } 3451 } else { 3452 /* 3453 * Use the larger of the two f_iosize values. If they are 3454 * not the same size, one will normally be an exact multiple of 3455 * the other, since they are both likely to be a power of 2. 3456 */ 3457 blksize = MAX(invp->v_mount->mnt_stat.f_iosize, 3458 outvp->v_mount->mnt_stat.f_iosize); 3459 } 3460 3461 /* Clip to sane limits. */ 3462 if (blksize < 4096) 3463 blksize = 4096; 3464 else if (blksize > maxphys) 3465 blksize = maxphys; 3466 dat = malloc(blksize, M_TEMP, M_WAITOK); 3467 3468 /* 3469 * If VOP_IOCTL(FIOSEEKHOLE) works for invp, use it and FIOSEEKDATA 3470 * to find holes. Otherwise, just scan the read block for all 0s 3471 * in the inner loop where the data copying is done. 3472 * Note that some file systems such as NFSv3, NFSv4.0 and NFSv4.1 may 3473 * support holes on the server, but do not support FIOSEEKHOLE. 3474 * The kernel flag COPY_FILE_RANGE_TIMEO1SEC is used to indicate 3475 * that this function should return after 1second with a partial 3476 * completion. 3477 */ 3478 if ((flags & COPY_FILE_RANGE_TIMEO1SEC) != 0) { 3479 getnanouptime(&endts); 3480 endts.tv_sec++; 3481 } else 3482 timespecclear(&endts); 3483 holetoeof = eof = false; 3484 while (len > 0 && error == 0 && !eof && interrupted == 0) { 3485 endoff = 0; /* To shut up compilers. */ 3486 cantseek = true; 3487 startoff = *inoffp; 3488 copylen = len; 3489 3490 /* 3491 * Find the next data area. If there is just a hole to EOF, 3492 * FIOSEEKDATA should fail with ENXIO. 3493 * (I do not know if any file system will report a hole to 3494 * EOF via FIOSEEKHOLE, but I am pretty sure FIOSEEKDATA 3495 * will fail for those file systems.) 3496 * 3497 * For input files that don't support FIOSEEKDATA/FIOSEEKHOLE, 3498 * the code just falls through to the inner copy loop. 3499 */ 3500 error = EINVAL; 3501 if (holein > 0) { 3502 error = VOP_IOCTL(invp, FIOSEEKDATA, &startoff, 0, 3503 incred, curthread); 3504 if (error == ENXIO) { 3505 startoff = endoff = inva.va_size; 3506 eof = holetoeof = true; 3507 error = 0; 3508 } 3509 } 3510 if (error == 0 && !holetoeof) { 3511 endoff = startoff; 3512 error = VOP_IOCTL(invp, FIOSEEKHOLE, &endoff, 0, 3513 incred, curthread); 3514 /* 3515 * Since invp is unlocked, it may be possible for 3516 * another thread to do a truncate(), lseek(), write() 3517 * creating a hole at startoff between the above 3518 * VOP_IOCTL() calls, if the other thread does not do 3519 * rangelocking. 3520 * If that happens, startoff == endoff and finding 3521 * the hole has failed, so set an error. 3522 */ 3523 if (error == 0 && startoff == endoff) 3524 error = EINVAL; /* Any error. Reset to 0. */ 3525 } 3526 if (error == 0) { 3527 if (startoff > *inoffp) { 3528 /* Found hole before data block. */ 3529 xfer = MIN(startoff - *inoffp, len); 3530 if (*outoffp < outsize) { 3531 /* Must write 0s to punch hole. */ 3532 xfer2 = MIN(outsize - *outoffp, 3533 xfer); 3534 memset(dat, 0, MIN(xfer2, blksize)); 3535 error = vn_write_outvp(outvp, dat, 3536 *outoffp, xfer2, blksize, false, 3537 holeout > 0, outcred); 3538 } 3539 3540 if (error == 0 && *outoffp + xfer > 3541 outsize && (xfer == len || holetoeof)) { 3542 /* Grow output file (hole at end). */ 3543 error = vn_write_outvp(outvp, dat, 3544 *outoffp, xfer, blksize, true, 3545 false, outcred); 3546 } 3547 if (error == 0) { 3548 *inoffp += xfer; 3549 *outoffp += xfer; 3550 len -= xfer; 3551 if (len < savlen) { 3552 interrupted = sig_intr(); 3553 if (timespecisset(&endts) && 3554 interrupted == 0) { 3555 getnanouptime(&curts); 3556 if (timespeccmp(&curts, 3557 &endts, >=)) 3558 interrupted = 3559 EINTR; 3560 } 3561 } 3562 } 3563 } 3564 copylen = MIN(len, endoff - startoff); 3565 cantseek = false; 3566 } else { 3567 cantseek = true; 3568 if (!sparse) 3569 cantseek = false; 3570 startoff = *inoffp; 3571 copylen = len; 3572 error = 0; 3573 } 3574 3575 xfer = blksize; 3576 if (cantseek) { 3577 /* 3578 * Set first xfer to end at a block boundary, so that 3579 * holes are more likely detected in the loop below via 3580 * the for all bytes 0 method. 3581 */ 3582 xfer -= (*inoffp % blksize); 3583 } 3584 /* Loop copying the data block. */ 3585 while (copylen > 0 && error == 0 && !eof && interrupted == 0) { 3586 if (copylen < xfer) 3587 xfer = copylen; 3588 error = vn_lock(invp, LK_SHARED); 3589 if (error != 0) 3590 goto out; 3591 error = vn_rdwr(UIO_READ, invp, dat, xfer, 3592 startoff, UIO_SYSSPACE, IO_NODELOCKED, 3593 curthread->td_ucred, incred, &aresid, 3594 curthread); 3595 VOP_UNLOCK(invp); 3596 lastblock = false; 3597 if (error == 0 && aresid > 0) { 3598 /* Stop the copy at EOF on the input file. */ 3599 xfer -= aresid; 3600 eof = true; 3601 lastblock = true; 3602 } 3603 if (error == 0) { 3604 /* 3605 * Skip the write for holes past the initial EOF 3606 * of the output file, unless this is the last 3607 * write of the output file at EOF. 3608 */ 3609 readzeros = cantseek ? mem_iszero(dat, xfer) : 3610 false; 3611 if (xfer == len) 3612 lastblock = true; 3613 if (!cantseek || *outoffp < outsize || 3614 lastblock || !readzeros) 3615 error = vn_write_outvp(outvp, dat, 3616 *outoffp, xfer, blksize, 3617 readzeros && lastblock && 3618 *outoffp >= outsize, false, 3619 outcred); 3620 if (error == 0) { 3621 *inoffp += xfer; 3622 startoff += xfer; 3623 *outoffp += xfer; 3624 copylen -= xfer; 3625 len -= xfer; 3626 if (len < savlen) { 3627 interrupted = sig_intr(); 3628 if (timespecisset(&endts) && 3629 interrupted == 0) { 3630 getnanouptime(&curts); 3631 if (timespeccmp(&curts, 3632 &endts, >=)) 3633 interrupted = 3634 EINTR; 3635 } 3636 } 3637 } 3638 } 3639 xfer = blksize; 3640 } 3641 } 3642 out: 3643 *lenp = savlen - len; 3644 free(dat, M_TEMP); 3645 return (error); 3646 } 3647 3648 static int 3649 vn_fallocate(struct file *fp, off_t offset, off_t len, struct thread *td) 3650 { 3651 struct mount *mp; 3652 struct vnode *vp; 3653 off_t olen, ooffset; 3654 int error; 3655 #ifdef AUDIT 3656 int audited_vnode1 = 0; 3657 #endif 3658 3659 vp = fp->f_vnode; 3660 if (vp->v_type != VREG) 3661 return (ENODEV); 3662 3663 /* Allocating blocks may take a long time, so iterate. */ 3664 for (;;) { 3665 olen = len; 3666 ooffset = offset; 3667 3668 bwillwrite(); 3669 mp = NULL; 3670 error = vn_start_write(vp, &mp, V_WAIT | V_PCATCH); 3671 if (error != 0) 3672 break; 3673 error = vn_lock(vp, LK_EXCLUSIVE); 3674 if (error != 0) { 3675 vn_finished_write(mp); 3676 break; 3677 } 3678 #ifdef AUDIT 3679 if (!audited_vnode1) { 3680 AUDIT_ARG_VNODE1(vp); 3681 audited_vnode1 = 1; 3682 } 3683 #endif 3684 #ifdef MAC 3685 error = mac_vnode_check_write(td->td_ucred, fp->f_cred, vp); 3686 if (error == 0) 3687 #endif 3688 error = VOP_ALLOCATE(vp, &offset, &len, 0, 3689 td->td_ucred); 3690 VOP_UNLOCK(vp); 3691 vn_finished_write(mp); 3692 3693 if (olen + ooffset != offset + len) { 3694 panic("offset + len changed from %jx/%jx to %jx/%jx", 3695 ooffset, olen, offset, len); 3696 } 3697 if (error != 0 || len == 0) 3698 break; 3699 KASSERT(olen > len, ("Iteration did not make progress?")); 3700 maybe_yield(); 3701 } 3702 3703 return (error); 3704 } 3705 3706 static int 3707 vn_deallocate_impl(struct vnode *vp, off_t *offset, off_t *length, int flags, 3708 int ioflag, struct ucred *cred, struct ucred *active_cred, 3709 struct ucred *file_cred) 3710 { 3711 struct mount *mp; 3712 void *rl_cookie; 3713 off_t off, len; 3714 int error; 3715 #ifdef AUDIT 3716 bool audited_vnode1 = false; 3717 #endif 3718 3719 rl_cookie = NULL; 3720 error = 0; 3721 mp = NULL; 3722 off = *offset; 3723 len = *length; 3724 3725 if ((ioflag & (IO_NODELOCKED | IO_RANGELOCKED)) == 0) 3726 rl_cookie = vn_rangelock_wlock(vp, off, off + len); 3727 while (len > 0 && error == 0) { 3728 /* 3729 * Try to deallocate the longest range in one pass. 3730 * In case a pass takes too long to be executed, it returns 3731 * partial result. The residue will be proceeded in the next 3732 * pass. 3733 */ 3734 3735 if ((ioflag & IO_NODELOCKED) == 0) { 3736 bwillwrite(); 3737 if ((error = vn_start_write(vp, &mp, 3738 V_WAIT | V_PCATCH)) != 0) 3739 goto out; 3740 vn_lock(vp, vn_lktype_write(mp, vp) | LK_RETRY); 3741 } 3742 #ifdef AUDIT 3743 if (!audited_vnode1) { 3744 AUDIT_ARG_VNODE1(vp); 3745 audited_vnode1 = true; 3746 } 3747 #endif 3748 3749 #ifdef MAC 3750 if ((ioflag & IO_NOMACCHECK) == 0) 3751 error = mac_vnode_check_write(active_cred, file_cred, 3752 vp); 3753 #endif 3754 if (error == 0) 3755 error = VOP_DEALLOCATE(vp, &off, &len, flags, ioflag, 3756 cred); 3757 3758 if ((ioflag & IO_NODELOCKED) == 0) { 3759 VOP_UNLOCK(vp); 3760 if (mp != NULL) { 3761 vn_finished_write(mp); 3762 mp = NULL; 3763 } 3764 } 3765 if (error == 0 && len != 0) 3766 maybe_yield(); 3767 } 3768 out: 3769 if (rl_cookie != NULL) 3770 vn_rangelock_unlock(vp, rl_cookie); 3771 *offset = off; 3772 *length = len; 3773 return (error); 3774 } 3775 3776 /* 3777 * This function is supposed to be used in the situations where the deallocation 3778 * is not triggered by a user request. 3779 */ 3780 int 3781 vn_deallocate(struct vnode *vp, off_t *offset, off_t *length, int flags, 3782 int ioflag, struct ucred *active_cred, struct ucred *file_cred) 3783 { 3784 struct ucred *cred; 3785 3786 if (*offset < 0 || *length <= 0 || *length > OFF_MAX - *offset || 3787 flags != 0) 3788 return (EINVAL); 3789 if (vp->v_type != VREG) 3790 return (ENODEV); 3791 3792 cred = file_cred != NOCRED ? file_cred : active_cred; 3793 return (vn_deallocate_impl(vp, offset, length, flags, ioflag, cred, 3794 active_cred, file_cred)); 3795 } 3796 3797 static int 3798 vn_fspacectl(struct file *fp, int cmd, off_t *offset, off_t *length, int flags, 3799 struct ucred *active_cred, struct thread *td) 3800 { 3801 int error; 3802 struct vnode *vp; 3803 int ioflag; 3804 3805 KASSERT(cmd == SPACECTL_DEALLOC, ("vn_fspacectl: Invalid cmd")); 3806 KASSERT((flags & ~SPACECTL_F_SUPPORTED) == 0, 3807 ("vn_fspacectl: non-zero flags")); 3808 KASSERT(*offset >= 0 && *length > 0 && *length <= OFF_MAX - *offset, 3809 ("vn_fspacectl: offset/length overflow or underflow")); 3810 vp = fp->f_vnode; 3811 3812 if (vp->v_type != VREG) 3813 return (ENODEV); 3814 3815 ioflag = get_write_ioflag(fp); 3816 3817 switch (cmd) { 3818 case SPACECTL_DEALLOC: 3819 error = vn_deallocate_impl(vp, offset, length, flags, ioflag, 3820 active_cred, active_cred, fp->f_cred); 3821 break; 3822 default: 3823 panic("vn_fspacectl: unknown cmd %d", cmd); 3824 } 3825 3826 return (error); 3827 } 3828 3829 /* 3830 * Keep this assert as long as sizeof(struct dirent) is used as the maximum 3831 * entry size. 3832 */ 3833 _Static_assert(_GENERIC_MAXDIRSIZ == sizeof(struct dirent), 3834 "'struct dirent' size must be a multiple of its alignment " 3835 "(see _GENERIC_DIRLEN())"); 3836 3837 /* 3838 * Returns successive directory entries through some caller's provided buffer. 3839 * 3840 * This function automatically refills the provided buffer with calls to 3841 * VOP_READDIR() (after MAC permission checks). 3842 * 3843 * 'td' is used for credentials and passed to uiomove(). 'dirbuf' is the 3844 * caller's buffer to fill and 'dirbuflen' its allocated size. 'dirbuf' must 3845 * be properly aligned to access 'struct dirent' structures and 'dirbuflen' 3846 * must be greater than GENERIC_MAXDIRSIZ to avoid VOP_READDIR() returning 3847 * EINVAL (the latter is not a strong guarantee (yet); but EINVAL will always 3848 * be returned if this requirement is not verified). '*dpp' points to the 3849 * current directory entry in the buffer and '*len' contains the remaining 3850 * valid bytes in 'dirbuf' after 'dpp' (including the pointed entry). 3851 * 3852 * At first call (or when restarting the read), '*len' must have been set to 0, 3853 * '*off' to 0 (or any valid start offset) and '*eofflag' to 0. There are no 3854 * more entries as soon as '*len' is 0 after a call that returned 0. Calling 3855 * again this function after such a condition is considered an error and EINVAL 3856 * will be returned. Other possible error codes are those of VOP_READDIR(), 3857 * EINTEGRITY if the returned entries do not pass coherency tests, or EINVAL 3858 * (bad call). All errors are unrecoverable, i.e., the state ('*len', '*off' 3859 * and '*eofflag') must be re-initialized before a subsequent call. On error 3860 * or at end of directory, '*dpp' is reset to NULL. 3861 * 3862 * '*len', '*off' and '*eofflag' are internal state the caller should not 3863 * tamper with except as explained above. '*off' is the next directory offset 3864 * to read from to refill the buffer. '*eofflag' is set to 0 or 1 by the last 3865 * internal call to VOP_READDIR() that returned without error, indicating 3866 * whether it reached the end of the directory, and to 2 by this function after 3867 * all entries have been read. 3868 */ 3869 int 3870 vn_dir_next_dirent(struct vnode *vp, struct thread *td, 3871 char *dirbuf, size_t dirbuflen, 3872 struct dirent **dpp, size_t *len, off_t *off, int *eofflag) 3873 { 3874 struct dirent *dp = NULL; 3875 int reclen; 3876 int error; 3877 struct uio uio; 3878 struct iovec iov; 3879 3880 ASSERT_VOP_LOCKED(vp, "vnode not locked"); 3881 VNASSERT(vp->v_type == VDIR, vp, ("vnode is not a directory")); 3882 MPASS2((uintptr_t)dirbuf < (uintptr_t)dirbuf + dirbuflen, 3883 "Address space overflow"); 3884 3885 if (__predict_false(dirbuflen < GENERIC_MAXDIRSIZ)) { 3886 /* Don't take any chances in this case */ 3887 error = EINVAL; 3888 goto out; 3889 } 3890 3891 if (*len != 0) { 3892 dp = *dpp; 3893 3894 /* 3895 * The caller continued to call us after an error (we set dp to 3896 * NULL in a previous iteration). Bail out right now. 3897 */ 3898 if (__predict_false(dp == NULL)) 3899 return (EINVAL); 3900 3901 MPASS(*len <= dirbuflen); 3902 MPASS2((uintptr_t)dirbuf <= (uintptr_t)dp && 3903 (uintptr_t)dp + *len <= (uintptr_t)dirbuf + dirbuflen, 3904 "Filled range not inside buffer"); 3905 3906 reclen = dp->d_reclen; 3907 if (reclen >= *len) { 3908 /* End of buffer reached */ 3909 *len = 0; 3910 } else { 3911 dp = (struct dirent *)((char *)dp + reclen); 3912 *len -= reclen; 3913 } 3914 } 3915 3916 if (*len == 0) { 3917 dp = NULL; 3918 3919 /* Have to refill. */ 3920 switch (*eofflag) { 3921 case 0: 3922 break; 3923 3924 case 1: 3925 /* Nothing more to read. */ 3926 *eofflag = 2; /* Remember the caller reached EOF. */ 3927 goto success; 3928 3929 default: 3930 /* The caller didn't test for EOF. */ 3931 error = EINVAL; 3932 goto out; 3933 } 3934 3935 iov.iov_base = dirbuf; 3936 iov.iov_len = dirbuflen; 3937 3938 uio.uio_iov = &iov; 3939 uio.uio_iovcnt = 1; 3940 uio.uio_offset = *off; 3941 uio.uio_resid = dirbuflen; 3942 uio.uio_segflg = UIO_SYSSPACE; 3943 uio.uio_rw = UIO_READ; 3944 uio.uio_td = td; 3945 3946 #ifdef MAC 3947 error = mac_vnode_check_readdir(td->td_ucred, vp); 3948 if (error == 0) 3949 #endif 3950 error = VOP_READDIR(vp, &uio, td->td_ucred, eofflag, 3951 NULL, NULL); 3952 if (error != 0) 3953 goto out; 3954 3955 *len = dirbuflen - uio.uio_resid; 3956 *off = uio.uio_offset; 3957 3958 if (*len == 0) { 3959 /* Sanity check on INVARIANTS. */ 3960 MPASS(*eofflag != 0); 3961 *eofflag = 1; 3962 goto success; 3963 } 3964 3965 /* 3966 * Normalize the flag returned by VOP_READDIR(), since we use 2 3967 * as a sentinel value. 3968 */ 3969 if (*eofflag != 0) 3970 *eofflag = 1; 3971 3972 dp = (struct dirent *)dirbuf; 3973 } 3974 3975 if (__predict_false(*len < GENERIC_MINDIRSIZ || 3976 dp->d_reclen < GENERIC_MINDIRSIZ)) { 3977 error = EINTEGRITY; 3978 dp = NULL; 3979 goto out; 3980 } 3981 3982 success: 3983 error = 0; 3984 out: 3985 *dpp = dp; 3986 return (error); 3987 } 3988 3989 /* 3990 * Checks whether a directory is empty or not. 3991 * 3992 * If the directory is empty, returns 0, and if it is not, ENOTEMPTY. Other 3993 * values are genuine errors preventing the check. 3994 */ 3995 int 3996 vn_dir_check_empty(struct vnode *vp) 3997 { 3998 struct thread *const td = curthread; 3999 char *dirbuf; 4000 size_t dirbuflen, len; 4001 off_t off; 4002 int eofflag, error; 4003 struct dirent *dp; 4004 struct vattr va; 4005 4006 ASSERT_VOP_LOCKED(vp, "vfs_emptydir"); 4007 VNPASS(vp->v_type == VDIR, vp); 4008 4009 error = VOP_GETATTR(vp, &va, td->td_ucred); 4010 if (error != 0) 4011 return (error); 4012 4013 dirbuflen = max(DEV_BSIZE, GENERIC_MAXDIRSIZ); 4014 if (dirbuflen < va.va_blocksize) 4015 dirbuflen = va.va_blocksize; 4016 dirbuf = malloc(dirbuflen, M_TEMP, M_WAITOK); 4017 4018 len = 0; 4019 off = 0; 4020 eofflag = 0; 4021 4022 for (;;) { 4023 error = vn_dir_next_dirent(vp, td, dirbuf, dirbuflen, 4024 &dp, &len, &off, &eofflag); 4025 if (error != 0) 4026 goto end; 4027 4028 if (len == 0) { 4029 /* EOF */ 4030 error = 0; 4031 goto end; 4032 } 4033 4034 /* 4035 * Skip whiteouts. Unionfs operates on filesystems only and 4036 * not on hierarchies, so these whiteouts would be shadowed on 4037 * the system hierarchy but not for a union using the 4038 * filesystem of their directories as the upper layer. 4039 * Additionally, unionfs currently transparently exposes 4040 * union-specific metadata of its upper layer, meaning that 4041 * whiteouts can be seen through the union view in empty 4042 * directories. Taking into account these whiteouts would then 4043 * prevent mounting another filesystem on such effectively 4044 * empty directories. 4045 */ 4046 if (dp->d_type == DT_WHT) 4047 continue; 4048 4049 /* 4050 * Any file in the directory which is not '.' or '..' indicates 4051 * the directory is not empty. 4052 */ 4053 switch (dp->d_namlen) { 4054 case 2: 4055 if (dp->d_name[1] != '.') { 4056 /* Can't be '..' (nor '.') */ 4057 error = ENOTEMPTY; 4058 goto end; 4059 } 4060 /* FALLTHROUGH */ 4061 case 1: 4062 if (dp->d_name[0] != '.') { 4063 /* Can't be '..' nor '.' */ 4064 error = ENOTEMPTY; 4065 goto end; 4066 } 4067 break; 4068 4069 default: 4070 error = ENOTEMPTY; 4071 goto end; 4072 } 4073 } 4074 4075 end: 4076 free(dirbuf, M_TEMP); 4077 return (error); 4078 } 4079 4080 4081 static u_long vn_lock_pair_pause_cnt; 4082 SYSCTL_ULONG(_debug, OID_AUTO, vn_lock_pair_pause, CTLFLAG_RD, 4083 &vn_lock_pair_pause_cnt, 0, 4084 "Count of vn_lock_pair deadlocks"); 4085 4086 u_int vn_lock_pair_pause_max; 4087 SYSCTL_UINT(_debug, OID_AUTO, vn_lock_pair_pause_max, CTLFLAG_RW, 4088 &vn_lock_pair_pause_max, 0, 4089 "Max ticks for vn_lock_pair deadlock avoidance sleep"); 4090 4091 static void 4092 vn_lock_pair_pause(const char *wmesg) 4093 { 4094 atomic_add_long(&vn_lock_pair_pause_cnt, 1); 4095 pause(wmesg, prng32_bounded(vn_lock_pair_pause_max)); 4096 } 4097 4098 /* 4099 * Lock pair of (possibly same) vnodes vp1, vp2, avoiding lock order 4100 * reversal. vp1_locked indicates whether vp1 is locked; if not, vp1 4101 * must be unlocked. Same for vp2 and vp2_locked. One of the vnodes 4102 * can be NULL. 4103 * 4104 * The function returns with both vnodes exclusively or shared locked, 4105 * according to corresponding lkflags, and guarantees that it does not 4106 * create lock order reversal with other threads during its execution. 4107 * Both vnodes could be unlocked temporary (and reclaimed). 4108 * 4109 * If requesting shared locking, locked vnode lock must not be recursed. 4110 * 4111 * Only one of LK_SHARED and LK_EXCLUSIVE must be specified. 4112 * LK_NODDLKTREAT can be optionally passed. 4113 * 4114 * If vp1 == vp2, only one, most exclusive, lock is obtained on it. 4115 */ 4116 void 4117 vn_lock_pair(struct vnode *vp1, bool vp1_locked, int lkflags1, 4118 struct vnode *vp2, bool vp2_locked, int lkflags2) 4119 { 4120 int error, locked1; 4121 4122 MPASS((((lkflags1 & LK_SHARED) != 0) ^ ((lkflags1 & LK_EXCLUSIVE) != 0)) || 4123 (vp1 == NULL && lkflags1 == 0)); 4124 MPASS((lkflags1 & ~(LK_SHARED | LK_EXCLUSIVE | LK_NODDLKTREAT)) == 0); 4125 MPASS((((lkflags2 & LK_SHARED) != 0) ^ ((lkflags2 & LK_EXCLUSIVE) != 0)) || 4126 (vp2 == NULL && lkflags2 == 0)); 4127 MPASS((lkflags2 & ~(LK_SHARED | LK_EXCLUSIVE | LK_NODDLKTREAT)) == 0); 4128 4129 if (vp1 == NULL && vp2 == NULL) 4130 return; 4131 4132 if (vp1 == vp2) { 4133 MPASS(vp1_locked == vp2_locked); 4134 4135 /* Select the most exclusive mode for lock. */ 4136 if ((lkflags1 & LK_TYPE_MASK) != (lkflags2 & LK_TYPE_MASK)) 4137 lkflags1 = (lkflags1 & ~LK_SHARED) | LK_EXCLUSIVE; 4138 4139 if (vp1_locked) { 4140 ASSERT_VOP_LOCKED(vp1, "vp1"); 4141 4142 /* No need to relock if any lock is exclusive. */ 4143 if ((vp1->v_vnlock->lock_object.lo_flags & 4144 LK_NOSHARE) != 0) 4145 return; 4146 4147 locked1 = VOP_ISLOCKED(vp1); 4148 if (((lkflags1 & LK_SHARED) != 0 && 4149 locked1 != LK_EXCLUSIVE) || 4150 ((lkflags1 & LK_EXCLUSIVE) != 0 && 4151 locked1 == LK_EXCLUSIVE)) 4152 return; 4153 VOP_UNLOCK(vp1); 4154 } 4155 4156 ASSERT_VOP_UNLOCKED(vp1, "vp1"); 4157 vn_lock(vp1, lkflags1 | LK_RETRY); 4158 return; 4159 } 4160 4161 if (vp1 != NULL) { 4162 if ((lkflags1 & LK_SHARED) != 0 && 4163 (vp1->v_vnlock->lock_object.lo_flags & LK_NOSHARE) != 0) 4164 lkflags1 = (lkflags1 & ~LK_SHARED) | LK_EXCLUSIVE; 4165 if (vp1_locked && VOP_ISLOCKED(vp1) != LK_EXCLUSIVE) { 4166 ASSERT_VOP_LOCKED(vp1, "vp1"); 4167 if ((lkflags1 & LK_EXCLUSIVE) != 0) { 4168 VOP_UNLOCK(vp1); 4169 ASSERT_VOP_UNLOCKED(vp1, 4170 "vp1 shared recursed"); 4171 vp1_locked = false; 4172 } 4173 } else if (!vp1_locked) 4174 ASSERT_VOP_UNLOCKED(vp1, "vp1"); 4175 } else { 4176 vp1_locked = true; 4177 } 4178 4179 if (vp2 != NULL) { 4180 if ((lkflags2 & LK_SHARED) != 0 && 4181 (vp2->v_vnlock->lock_object.lo_flags & LK_NOSHARE) != 0) 4182 lkflags2 = (lkflags2 & ~LK_SHARED) | LK_EXCLUSIVE; 4183 if (vp2_locked && VOP_ISLOCKED(vp2) != LK_EXCLUSIVE) { 4184 ASSERT_VOP_LOCKED(vp2, "vp2"); 4185 if ((lkflags2 & LK_EXCLUSIVE) != 0) { 4186 VOP_UNLOCK(vp2); 4187 ASSERT_VOP_UNLOCKED(vp2, 4188 "vp2 shared recursed"); 4189 vp2_locked = false; 4190 } 4191 } else if (!vp2_locked) 4192 ASSERT_VOP_UNLOCKED(vp2, "vp2"); 4193 } else { 4194 vp2_locked = true; 4195 } 4196 4197 if (!vp1_locked && !vp2_locked) { 4198 vn_lock(vp1, lkflags1 | LK_RETRY); 4199 vp1_locked = true; 4200 } 4201 4202 while (!vp1_locked || !vp2_locked) { 4203 if (vp1_locked && vp2 != NULL) { 4204 if (vp1 != NULL) { 4205 error = VOP_LOCK1(vp2, lkflags2 | LK_NOWAIT, 4206 __FILE__, __LINE__); 4207 if (error == 0) 4208 break; 4209 VOP_UNLOCK(vp1); 4210 vp1_locked = false; 4211 vn_lock_pair_pause("vlp1"); 4212 } 4213 vn_lock(vp2, lkflags2 | LK_RETRY); 4214 vp2_locked = true; 4215 } 4216 if (vp2_locked && vp1 != NULL) { 4217 if (vp2 != NULL) { 4218 error = VOP_LOCK1(vp1, lkflags1 | LK_NOWAIT, 4219 __FILE__, __LINE__); 4220 if (error == 0) 4221 break; 4222 VOP_UNLOCK(vp2); 4223 vp2_locked = false; 4224 vn_lock_pair_pause("vlp2"); 4225 } 4226 vn_lock(vp1, lkflags1 | LK_RETRY); 4227 vp1_locked = true; 4228 } 4229 } 4230 if (vp1 != NULL) { 4231 if (lkflags1 == LK_EXCLUSIVE) 4232 ASSERT_VOP_ELOCKED(vp1, "vp1 ret"); 4233 else 4234 ASSERT_VOP_LOCKED(vp1, "vp1 ret"); 4235 } 4236 if (vp2 != NULL) { 4237 if (lkflags2 == LK_EXCLUSIVE) 4238 ASSERT_VOP_ELOCKED(vp2, "vp2 ret"); 4239 else 4240 ASSERT_VOP_LOCKED(vp2, "vp2 ret"); 4241 } 4242 } 4243 4244 int 4245 vn_lktype_write(struct mount *mp, struct vnode *vp) 4246 { 4247 if (MNT_SHARED_WRITES(mp) || 4248 (mp == NULL && MNT_SHARED_WRITES(vp->v_mount))) 4249 return (LK_SHARED); 4250 return (LK_EXCLUSIVE); 4251 } 4252 4253 int 4254 vn_cmp(struct file *fp1, struct file *fp2, struct thread *td) 4255 { 4256 if (fp2->f_type != DTYPE_VNODE) 4257 return (3); 4258 return (kcmp_cmp((uintptr_t)fp1->f_vnode, (uintptr_t)fp2->f_vnode)); 4259 } 4260