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