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