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