1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Copyright (c) 2012 Konstantin Belousov <kib@FreeBSD.org> 13 * Copyright (c) 2013, 2014 The FreeBSD Foundation 14 * 15 * Portions of this software were developed by Konstantin Belousov 16 * under sponsorship from the FreeBSD Foundation. 17 * 18 * Redistribution and use in source and binary forms, with or without 19 * modification, are permitted provided that the following conditions 20 * are met: 21 * 1. Redistributions of source code must retain the above copyright 22 * notice, this list of conditions and the following disclaimer. 23 * 2. Redistributions in binary form must reproduce the above copyright 24 * notice, this list of conditions and the following disclaimer in the 25 * documentation and/or other materials provided with the distribution. 26 * 3. Neither the name of the University nor the names of its contributors 27 * may be used to endorse or promote products derived from this software 28 * without specific prior written permission. 29 * 30 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 31 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 32 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 33 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 34 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 35 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 36 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 37 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 38 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 39 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 40 * SUCH DAMAGE. 41 * 42 * @(#)vfs_vnops.c 8.2 (Berkeley) 1/21/94 43 */ 44 45 #include <sys/cdefs.h> 46 __FBSDID("$FreeBSD$"); 47 48 #include "opt_hwpmc_hooks.h" 49 50 #include <sys/param.h> 51 #include <sys/systm.h> 52 #include <sys/disk.h> 53 #include <sys/fail.h> 54 #include <sys/fcntl.h> 55 #include <sys/file.h> 56 #include <sys/kdb.h> 57 #include <sys/ktr.h> 58 #include <sys/stat.h> 59 #include <sys/priv.h> 60 #include <sys/proc.h> 61 #include <sys/limits.h> 62 #include <sys/lock.h> 63 #include <sys/mman.h> 64 #include <sys/mount.h> 65 #include <sys/mutex.h> 66 #include <sys/namei.h> 67 #include <sys/vnode.h> 68 #include <sys/bio.h> 69 #include <sys/buf.h> 70 #include <sys/filio.h> 71 #include <sys/resourcevar.h> 72 #include <sys/rwlock.h> 73 #include <sys/sx.h> 74 #include <sys/sleepqueue.h> 75 #include <sys/sysctl.h> 76 #include <sys/ttycom.h> 77 #include <sys/conf.h> 78 #include <sys/syslog.h> 79 #include <sys/unistd.h> 80 #include <sys/user.h> 81 82 #include <security/audit/audit.h> 83 #include <security/mac/mac_framework.h> 84 85 #include <vm/vm.h> 86 #include <vm/vm_extern.h> 87 #include <vm/pmap.h> 88 #include <vm/vm_map.h> 89 #include <vm/vm_object.h> 90 #include <vm/vm_page.h> 91 #include <vm/vm_pager.h> 92 93 #ifdef HWPMC_HOOKS 94 #include <sys/pmckern.h> 95 #endif 96 97 static fo_rdwr_t vn_read; 98 static fo_rdwr_t vn_write; 99 static fo_rdwr_t vn_io_fault; 100 static fo_truncate_t vn_truncate; 101 static fo_ioctl_t vn_ioctl; 102 static fo_poll_t vn_poll; 103 static fo_kqfilter_t vn_kqfilter; 104 static fo_stat_t vn_statfile; 105 static fo_close_t vn_closefile; 106 static fo_mmap_t vn_mmap; 107 static fo_fallocate_t vn_fallocate; 108 109 struct fileops vnops = { 110 .fo_read = vn_io_fault, 111 .fo_write = vn_io_fault, 112 .fo_truncate = vn_truncate, 113 .fo_ioctl = vn_ioctl, 114 .fo_poll = vn_poll, 115 .fo_kqfilter = vn_kqfilter, 116 .fo_stat = vn_statfile, 117 .fo_close = vn_closefile, 118 .fo_chmod = vn_chmod, 119 .fo_chown = vn_chown, 120 .fo_sendfile = vn_sendfile, 121 .fo_seek = vn_seek, 122 .fo_fill_kinfo = vn_fill_kinfo, 123 .fo_mmap = vn_mmap, 124 .fo_fallocate = vn_fallocate, 125 .fo_flags = DFLAG_PASSABLE | DFLAG_SEEKABLE 126 }; 127 128 static const int io_hold_cnt = 16; 129 static int vn_io_fault_enable = 1; 130 SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_enable, CTLFLAG_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 static 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 static bool 955 do_vn_read_from_pgcache(struct vnode *vp, struct uio *uio, struct file *fp) 956 { 957 return ((vp->v_irflag & (VIRF_DOOMED | VIRF_PGREAD)) == VIRF_PGREAD && 958 !mac_vnode_check_read_enabled() && 959 uio->uio_resid <= ptoa(io_hold_cnt) && uio->uio_offset >= 0 && 960 (fp->f_flag & O_DIRECT) == 0 && vn_io_pgcache_read_enable); 961 } 962 963 /* 964 * File table vnode read routine. 965 */ 966 static int 967 vn_read(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags, 968 struct thread *td) 969 { 970 struct vnode *vp; 971 off_t orig_offset; 972 int error, ioflag; 973 int advice; 974 975 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", 976 uio->uio_td, td)); 977 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET")); 978 vp = fp->f_vnode; 979 if (do_vn_read_from_pgcache(vp, uio, fp)) { 980 error = vn_read_from_obj(vp, uio); 981 if (error == 0) { 982 fp->f_nextoff[UIO_READ] = uio->uio_offset; 983 return (0); 984 } 985 if (error != EJUSTRETURN) 986 return (error); 987 } 988 ioflag = 0; 989 if (fp->f_flag & FNONBLOCK) 990 ioflag |= IO_NDELAY; 991 if (fp->f_flag & O_DIRECT) 992 ioflag |= IO_DIRECT; 993 advice = get_advice(fp, uio); 994 vn_lock(vp, LK_SHARED | LK_RETRY); 995 996 switch (advice) { 997 case POSIX_FADV_NORMAL: 998 case POSIX_FADV_SEQUENTIAL: 999 case POSIX_FADV_NOREUSE: 1000 ioflag |= sequential_heuristic(uio, fp); 1001 break; 1002 case POSIX_FADV_RANDOM: 1003 /* Disable read-ahead for random I/O. */ 1004 break; 1005 } 1006 orig_offset = uio->uio_offset; 1007 1008 #ifdef MAC 1009 error = mac_vnode_check_read(active_cred, fp->f_cred, vp); 1010 if (error == 0) 1011 #endif 1012 error = VOP_READ(vp, uio, ioflag, fp->f_cred); 1013 fp->f_nextoff[UIO_READ] = uio->uio_offset; 1014 VOP_UNLOCK(vp); 1015 if (error == 0 && advice == POSIX_FADV_NOREUSE && 1016 orig_offset != uio->uio_offset) 1017 /* 1018 * Use POSIX_FADV_DONTNEED to flush pages and buffers 1019 * for the backing file after a POSIX_FADV_NOREUSE 1020 * read(2). 1021 */ 1022 error = VOP_ADVISE(vp, orig_offset, uio->uio_offset - 1, 1023 POSIX_FADV_DONTNEED); 1024 return (error); 1025 } 1026 1027 /* 1028 * File table vnode write routine. 1029 */ 1030 static int 1031 vn_write(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags, 1032 struct thread *td) 1033 { 1034 struct vnode *vp; 1035 struct mount *mp; 1036 off_t orig_offset; 1037 int error, ioflag, lock_flags; 1038 int advice; 1039 1040 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", 1041 uio->uio_td, td)); 1042 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET")); 1043 vp = fp->f_vnode; 1044 if (vp->v_type == VREG) 1045 bwillwrite(); 1046 ioflag = IO_UNIT; 1047 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 1048 ioflag |= IO_APPEND; 1049 if (fp->f_flag & FNONBLOCK) 1050 ioflag |= IO_NDELAY; 1051 if (fp->f_flag & O_DIRECT) 1052 ioflag |= IO_DIRECT; 1053 if ((fp->f_flag & O_FSYNC) || 1054 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS))) 1055 ioflag |= IO_SYNC; 1056 mp = NULL; 1057 if (vp->v_type != VCHR && 1058 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0) 1059 goto unlock; 1060 1061 advice = get_advice(fp, uio); 1062 1063 if (MNT_SHARED_WRITES(mp) || 1064 (mp == NULL && MNT_SHARED_WRITES(vp->v_mount))) { 1065 lock_flags = LK_SHARED; 1066 } else { 1067 lock_flags = LK_EXCLUSIVE; 1068 } 1069 1070 vn_lock(vp, lock_flags | LK_RETRY); 1071 switch (advice) { 1072 case POSIX_FADV_NORMAL: 1073 case POSIX_FADV_SEQUENTIAL: 1074 case POSIX_FADV_NOREUSE: 1075 ioflag |= sequential_heuristic(uio, fp); 1076 break; 1077 case POSIX_FADV_RANDOM: 1078 /* XXX: Is this correct? */ 1079 break; 1080 } 1081 orig_offset = uio->uio_offset; 1082 1083 #ifdef MAC 1084 error = mac_vnode_check_write(active_cred, fp->f_cred, vp); 1085 if (error == 0) 1086 #endif 1087 error = VOP_WRITE(vp, uio, ioflag, fp->f_cred); 1088 fp->f_nextoff[UIO_WRITE] = uio->uio_offset; 1089 VOP_UNLOCK(vp); 1090 if (vp->v_type != VCHR) 1091 vn_finished_write(mp); 1092 if (error == 0 && advice == POSIX_FADV_NOREUSE && 1093 orig_offset != uio->uio_offset) 1094 /* 1095 * Use POSIX_FADV_DONTNEED to flush pages and buffers 1096 * for the backing file after a POSIX_FADV_NOREUSE 1097 * write(2). 1098 */ 1099 error = VOP_ADVISE(vp, orig_offset, uio->uio_offset - 1, 1100 POSIX_FADV_DONTNEED); 1101 unlock: 1102 return (error); 1103 } 1104 1105 /* 1106 * The vn_io_fault() is a wrapper around vn_read() and vn_write() to 1107 * prevent the following deadlock: 1108 * 1109 * Assume that the thread A reads from the vnode vp1 into userspace 1110 * buffer buf1 backed by the pages of vnode vp2. If a page in buf1 is 1111 * currently not resident, then system ends up with the call chain 1112 * vn_read() -> VOP_READ(vp1) -> uiomove() -> [Page Fault] -> 1113 * vm_fault(buf1) -> vnode_pager_getpages(vp2) -> VOP_GETPAGES(vp2) 1114 * which establishes lock order vp1->vn_lock, then vp2->vn_lock. 1115 * If, at the same time, thread B reads from vnode vp2 into buffer buf2 1116 * backed by the pages of vnode vp1, and some page in buf2 is not 1117 * resident, we get a reversed order vp2->vn_lock, then vp1->vn_lock. 1118 * 1119 * To prevent the lock order reversal and deadlock, vn_io_fault() does 1120 * not allow page faults to happen during VOP_READ() or VOP_WRITE(). 1121 * Instead, it first tries to do the whole range i/o with pagefaults 1122 * disabled. If all pages in the i/o buffer are resident and mapped, 1123 * VOP will succeed (ignoring the genuine filesystem errors). 1124 * Otherwise, we get back EFAULT, and vn_io_fault() falls back to do 1125 * i/o in chunks, with all pages in the chunk prefaulted and held 1126 * using vm_fault_quick_hold_pages(). 1127 * 1128 * Filesystems using this deadlock avoidance scheme should use the 1129 * array of the held pages from uio, saved in the curthread->td_ma, 1130 * instead of doing uiomove(). A helper function 1131 * vn_io_fault_uiomove() converts uiomove request into 1132 * uiomove_fromphys() over td_ma array. 1133 * 1134 * Since vnode locks do not cover the whole i/o anymore, rangelocks 1135 * make the current i/o request atomic with respect to other i/os and 1136 * truncations. 1137 */ 1138 1139 /* 1140 * Decode vn_io_fault_args and perform the corresponding i/o. 1141 */ 1142 static int 1143 vn_io_fault_doio(struct vn_io_fault_args *args, struct uio *uio, 1144 struct thread *td) 1145 { 1146 int error, save; 1147 1148 error = 0; 1149 save = vm_fault_disable_pagefaults(); 1150 switch (args->kind) { 1151 case VN_IO_FAULT_FOP: 1152 error = (args->args.fop_args.doio)(args->args.fop_args.fp, 1153 uio, args->cred, args->flags, td); 1154 break; 1155 case VN_IO_FAULT_VOP: 1156 if (uio->uio_rw == UIO_READ) { 1157 error = VOP_READ(args->args.vop_args.vp, uio, 1158 args->flags, args->cred); 1159 } else if (uio->uio_rw == UIO_WRITE) { 1160 error = VOP_WRITE(args->args.vop_args.vp, uio, 1161 args->flags, args->cred); 1162 } 1163 break; 1164 default: 1165 panic("vn_io_fault_doio: unknown kind of io %d %d", 1166 args->kind, uio->uio_rw); 1167 } 1168 vm_fault_enable_pagefaults(save); 1169 return (error); 1170 } 1171 1172 static int 1173 vn_io_fault_touch(char *base, const struct uio *uio) 1174 { 1175 int r; 1176 1177 r = fubyte(base); 1178 if (r == -1 || (uio->uio_rw == UIO_READ && subyte(base, r) == -1)) 1179 return (EFAULT); 1180 return (0); 1181 } 1182 1183 static int 1184 vn_io_fault_prefault_user(const struct uio *uio) 1185 { 1186 char *base; 1187 const struct iovec *iov; 1188 size_t len; 1189 ssize_t resid; 1190 int error, i; 1191 1192 KASSERT(uio->uio_segflg == UIO_USERSPACE, 1193 ("vn_io_fault_prefault userspace")); 1194 1195 error = i = 0; 1196 iov = uio->uio_iov; 1197 resid = uio->uio_resid; 1198 base = iov->iov_base; 1199 len = iov->iov_len; 1200 while (resid > 0) { 1201 error = vn_io_fault_touch(base, uio); 1202 if (error != 0) 1203 break; 1204 if (len < PAGE_SIZE) { 1205 if (len != 0) { 1206 error = vn_io_fault_touch(base + len - 1, uio); 1207 if (error != 0) 1208 break; 1209 resid -= len; 1210 } 1211 if (++i >= uio->uio_iovcnt) 1212 break; 1213 iov = uio->uio_iov + i; 1214 base = iov->iov_base; 1215 len = iov->iov_len; 1216 } else { 1217 len -= PAGE_SIZE; 1218 base += PAGE_SIZE; 1219 resid -= PAGE_SIZE; 1220 } 1221 } 1222 return (error); 1223 } 1224 1225 /* 1226 * Common code for vn_io_fault(), agnostic to the kind of i/o request. 1227 * Uses vn_io_fault_doio() to make the call to an actual i/o function. 1228 * Used from vn_rdwr() and vn_io_fault(), which encode the i/o request 1229 * into args and call vn_io_fault1() to handle faults during the user 1230 * mode buffer accesses. 1231 */ 1232 static int 1233 vn_io_fault1(struct vnode *vp, struct uio *uio, struct vn_io_fault_args *args, 1234 struct thread *td) 1235 { 1236 vm_page_t ma[io_hold_cnt + 2]; 1237 struct uio *uio_clone, short_uio; 1238 struct iovec short_iovec[1]; 1239 vm_page_t *prev_td_ma; 1240 vm_prot_t prot; 1241 vm_offset_t addr, end; 1242 size_t len, resid; 1243 ssize_t adv; 1244 int error, cnt, saveheld, prev_td_ma_cnt; 1245 1246 if (vn_io_fault_prefault) { 1247 error = vn_io_fault_prefault_user(uio); 1248 if (error != 0) 1249 return (error); /* Or ignore ? */ 1250 } 1251 1252 prot = uio->uio_rw == UIO_READ ? VM_PROT_WRITE : VM_PROT_READ; 1253 1254 /* 1255 * The UFS follows IO_UNIT directive and replays back both 1256 * uio_offset and uio_resid if an error is encountered during the 1257 * operation. But, since the iovec may be already advanced, 1258 * uio is still in an inconsistent state. 1259 * 1260 * Cache a copy of the original uio, which is advanced to the redo 1261 * point using UIO_NOCOPY below. 1262 */ 1263 uio_clone = cloneuio(uio); 1264 resid = uio->uio_resid; 1265 1266 short_uio.uio_segflg = UIO_USERSPACE; 1267 short_uio.uio_rw = uio->uio_rw; 1268 short_uio.uio_td = uio->uio_td; 1269 1270 error = vn_io_fault_doio(args, uio, td); 1271 if (error != EFAULT) 1272 goto out; 1273 1274 atomic_add_long(&vn_io_faults_cnt, 1); 1275 uio_clone->uio_segflg = UIO_NOCOPY; 1276 uiomove(NULL, resid - uio->uio_resid, uio_clone); 1277 uio_clone->uio_segflg = uio->uio_segflg; 1278 1279 saveheld = curthread_pflags_set(TDP_UIOHELD); 1280 prev_td_ma = td->td_ma; 1281 prev_td_ma_cnt = td->td_ma_cnt; 1282 1283 while (uio_clone->uio_resid != 0) { 1284 len = uio_clone->uio_iov->iov_len; 1285 if (len == 0) { 1286 KASSERT(uio_clone->uio_iovcnt >= 1, 1287 ("iovcnt underflow")); 1288 uio_clone->uio_iov++; 1289 uio_clone->uio_iovcnt--; 1290 continue; 1291 } 1292 if (len > ptoa(io_hold_cnt)) 1293 len = ptoa(io_hold_cnt); 1294 addr = (uintptr_t)uio_clone->uio_iov->iov_base; 1295 end = round_page(addr + len); 1296 if (end < addr) { 1297 error = EFAULT; 1298 break; 1299 } 1300 cnt = atop(end - trunc_page(addr)); 1301 /* 1302 * A perfectly misaligned address and length could cause 1303 * both the start and the end of the chunk to use partial 1304 * page. +2 accounts for such a situation. 1305 */ 1306 cnt = vm_fault_quick_hold_pages(&td->td_proc->p_vmspace->vm_map, 1307 addr, len, prot, ma, io_hold_cnt + 2); 1308 if (cnt == -1) { 1309 error = EFAULT; 1310 break; 1311 } 1312 short_uio.uio_iov = &short_iovec[0]; 1313 short_iovec[0].iov_base = (void *)addr; 1314 short_uio.uio_iovcnt = 1; 1315 short_uio.uio_resid = short_iovec[0].iov_len = len; 1316 short_uio.uio_offset = uio_clone->uio_offset; 1317 td->td_ma = ma; 1318 td->td_ma_cnt = cnt; 1319 1320 error = vn_io_fault_doio(args, &short_uio, td); 1321 vm_page_unhold_pages(ma, cnt); 1322 adv = len - short_uio.uio_resid; 1323 1324 uio_clone->uio_iov->iov_base = 1325 (char *)uio_clone->uio_iov->iov_base + adv; 1326 uio_clone->uio_iov->iov_len -= adv; 1327 uio_clone->uio_resid -= adv; 1328 uio_clone->uio_offset += adv; 1329 1330 uio->uio_resid -= adv; 1331 uio->uio_offset += adv; 1332 1333 if (error != 0 || adv == 0) 1334 break; 1335 } 1336 td->td_ma = prev_td_ma; 1337 td->td_ma_cnt = prev_td_ma_cnt; 1338 curthread_pflags_restore(saveheld); 1339 out: 1340 free(uio_clone, M_IOV); 1341 return (error); 1342 } 1343 1344 static int 1345 vn_io_fault(struct file *fp, struct uio *uio, struct ucred *active_cred, 1346 int flags, struct thread *td) 1347 { 1348 fo_rdwr_t *doio; 1349 struct vnode *vp; 1350 void *rl_cookie; 1351 struct vn_io_fault_args args; 1352 int error; 1353 1354 doio = uio->uio_rw == UIO_READ ? vn_read : vn_write; 1355 vp = fp->f_vnode; 1356 1357 /* 1358 * The ability to read(2) on a directory has historically been 1359 * allowed for all users, but this can and has been the source of 1360 * at least one security issue in the past. As such, it is now hidden 1361 * away behind a sysctl for those that actually need it to use it, and 1362 * restricted to root when it's turned on to make it relatively safe to 1363 * leave on for longer sessions of need. 1364 */ 1365 if (vp->v_type == VDIR) { 1366 KASSERT(uio->uio_rw == UIO_READ, 1367 ("illegal write attempted on a directory")); 1368 if (!vfs_allow_read_dir) 1369 return (EISDIR); 1370 if ((error = priv_check(td, PRIV_VFS_READ_DIR)) != 0) 1371 return (EISDIR); 1372 } 1373 1374 foffset_lock_uio(fp, uio, flags); 1375 if (do_vn_io_fault(vp, uio)) { 1376 args.kind = VN_IO_FAULT_FOP; 1377 args.args.fop_args.fp = fp; 1378 args.args.fop_args.doio = doio; 1379 args.cred = active_cred; 1380 args.flags = flags | FOF_OFFSET; 1381 if (uio->uio_rw == UIO_READ) { 1382 rl_cookie = vn_rangelock_rlock(vp, uio->uio_offset, 1383 uio->uio_offset + uio->uio_resid); 1384 } else if ((fp->f_flag & O_APPEND) != 0 || 1385 (flags & FOF_OFFSET) == 0) { 1386 /* For appenders, punt and lock the whole range. */ 1387 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 1388 } else { 1389 rl_cookie = vn_rangelock_wlock(vp, uio->uio_offset, 1390 uio->uio_offset + uio->uio_resid); 1391 } 1392 error = vn_io_fault1(vp, uio, &args, td); 1393 vn_rangelock_unlock(vp, rl_cookie); 1394 } else { 1395 error = doio(fp, uio, active_cred, flags | FOF_OFFSET, td); 1396 } 1397 foffset_unlock_uio(fp, uio, flags); 1398 return (error); 1399 } 1400 1401 /* 1402 * Helper function to perform the requested uiomove operation using 1403 * the held pages for io->uio_iov[0].iov_base buffer instead of 1404 * copyin/copyout. Access to the pages with uiomove_fromphys() 1405 * instead of iov_base prevents page faults that could occur due to 1406 * pmap_collect() invalidating the mapping created by 1407 * vm_fault_quick_hold_pages(), or pageout daemon, page laundry or 1408 * object cleanup revoking the write access from page mappings. 1409 * 1410 * Filesystems specified MNTK_NO_IOPF shall use vn_io_fault_uiomove() 1411 * instead of plain uiomove(). 1412 */ 1413 int 1414 vn_io_fault_uiomove(char *data, int xfersize, struct uio *uio) 1415 { 1416 struct uio transp_uio; 1417 struct iovec transp_iov[1]; 1418 struct thread *td; 1419 size_t adv; 1420 int error, pgadv; 1421 1422 td = curthread; 1423 if ((td->td_pflags & TDP_UIOHELD) == 0 || 1424 uio->uio_segflg != UIO_USERSPACE) 1425 return (uiomove(data, xfersize, uio)); 1426 1427 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt)); 1428 transp_iov[0].iov_base = data; 1429 transp_uio.uio_iov = &transp_iov[0]; 1430 transp_uio.uio_iovcnt = 1; 1431 if (xfersize > uio->uio_resid) 1432 xfersize = uio->uio_resid; 1433 transp_uio.uio_resid = transp_iov[0].iov_len = xfersize; 1434 transp_uio.uio_offset = 0; 1435 transp_uio.uio_segflg = UIO_SYSSPACE; 1436 /* 1437 * Since transp_iov points to data, and td_ma page array 1438 * corresponds to original uio->uio_iov, we need to invert the 1439 * direction of the i/o operation as passed to 1440 * uiomove_fromphys(). 1441 */ 1442 switch (uio->uio_rw) { 1443 case UIO_WRITE: 1444 transp_uio.uio_rw = UIO_READ; 1445 break; 1446 case UIO_READ: 1447 transp_uio.uio_rw = UIO_WRITE; 1448 break; 1449 } 1450 transp_uio.uio_td = uio->uio_td; 1451 error = uiomove_fromphys(td->td_ma, 1452 ((vm_offset_t)uio->uio_iov->iov_base) & PAGE_MASK, 1453 xfersize, &transp_uio); 1454 adv = xfersize - transp_uio.uio_resid; 1455 pgadv = 1456 (((vm_offset_t)uio->uio_iov->iov_base + adv) >> PAGE_SHIFT) - 1457 (((vm_offset_t)uio->uio_iov->iov_base) >> PAGE_SHIFT); 1458 td->td_ma += pgadv; 1459 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt, 1460 pgadv)); 1461 td->td_ma_cnt -= pgadv; 1462 uio->uio_iov->iov_base = (char *)uio->uio_iov->iov_base + adv; 1463 uio->uio_iov->iov_len -= adv; 1464 uio->uio_resid -= adv; 1465 uio->uio_offset += adv; 1466 return (error); 1467 } 1468 1469 int 1470 vn_io_fault_pgmove(vm_page_t ma[], vm_offset_t offset, int xfersize, 1471 struct uio *uio) 1472 { 1473 struct thread *td; 1474 vm_offset_t iov_base; 1475 int cnt, pgadv; 1476 1477 td = curthread; 1478 if ((td->td_pflags & TDP_UIOHELD) == 0 || 1479 uio->uio_segflg != UIO_USERSPACE) 1480 return (uiomove_fromphys(ma, offset, xfersize, uio)); 1481 1482 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt)); 1483 cnt = xfersize > uio->uio_resid ? uio->uio_resid : xfersize; 1484 iov_base = (vm_offset_t)uio->uio_iov->iov_base; 1485 switch (uio->uio_rw) { 1486 case UIO_WRITE: 1487 pmap_copy_pages(td->td_ma, iov_base & PAGE_MASK, ma, 1488 offset, cnt); 1489 break; 1490 case UIO_READ: 1491 pmap_copy_pages(ma, offset, td->td_ma, iov_base & PAGE_MASK, 1492 cnt); 1493 break; 1494 } 1495 pgadv = ((iov_base + cnt) >> PAGE_SHIFT) - (iov_base >> PAGE_SHIFT); 1496 td->td_ma += pgadv; 1497 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt, 1498 pgadv)); 1499 td->td_ma_cnt -= pgadv; 1500 uio->uio_iov->iov_base = (char *)(iov_base + cnt); 1501 uio->uio_iov->iov_len -= cnt; 1502 uio->uio_resid -= cnt; 1503 uio->uio_offset += cnt; 1504 return (0); 1505 } 1506 1507 /* 1508 * File table truncate routine. 1509 */ 1510 static int 1511 vn_truncate(struct file *fp, off_t length, struct ucred *active_cred, 1512 struct thread *td) 1513 { 1514 struct mount *mp; 1515 struct vnode *vp; 1516 void *rl_cookie; 1517 int error; 1518 1519 vp = fp->f_vnode; 1520 1521 /* 1522 * Lock the whole range for truncation. Otherwise split i/o 1523 * might happen partly before and partly after the truncation. 1524 */ 1525 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 1526 error = vn_start_write(vp, &mp, V_WAIT | PCATCH); 1527 if (error) 1528 goto out1; 1529 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1530 AUDIT_ARG_VNODE1(vp); 1531 if (vp->v_type == VDIR) { 1532 error = EISDIR; 1533 goto out; 1534 } 1535 #ifdef MAC 1536 error = mac_vnode_check_write(active_cred, fp->f_cred, vp); 1537 if (error) 1538 goto out; 1539 #endif 1540 error = vn_truncate_locked(vp, length, (fp->f_flag & O_FSYNC) != 0, 1541 fp->f_cred); 1542 out: 1543 VOP_UNLOCK(vp); 1544 vn_finished_write(mp); 1545 out1: 1546 vn_rangelock_unlock(vp, rl_cookie); 1547 return (error); 1548 } 1549 1550 /* 1551 * Truncate a file that is already locked. 1552 */ 1553 int 1554 vn_truncate_locked(struct vnode *vp, off_t length, bool sync, 1555 struct ucred *cred) 1556 { 1557 struct vattr vattr; 1558 int error; 1559 1560 error = VOP_ADD_WRITECOUNT(vp, 1); 1561 if (error == 0) { 1562 VATTR_NULL(&vattr); 1563 vattr.va_size = length; 1564 if (sync) 1565 vattr.va_vaflags |= VA_SYNC; 1566 error = VOP_SETATTR(vp, &vattr, cred); 1567 VOP_ADD_WRITECOUNT_CHECKED(vp, -1); 1568 } 1569 return (error); 1570 } 1571 1572 /* 1573 * File table vnode stat routine. 1574 */ 1575 static int 1576 vn_statfile(struct file *fp, struct stat *sb, struct ucred *active_cred, 1577 struct thread *td) 1578 { 1579 struct vnode *vp = fp->f_vnode; 1580 int error; 1581 1582 vn_lock(vp, LK_SHARED | LK_RETRY); 1583 error = VOP_STAT(vp, sb, active_cred, fp->f_cred, td); 1584 VOP_UNLOCK(vp); 1585 1586 return (error); 1587 } 1588 1589 /* 1590 * File table vnode ioctl routine. 1591 */ 1592 static int 1593 vn_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 1594 struct thread *td) 1595 { 1596 struct vattr vattr; 1597 struct vnode *vp; 1598 struct fiobmap2_arg *bmarg; 1599 int error; 1600 1601 vp = fp->f_vnode; 1602 switch (vp->v_type) { 1603 case VDIR: 1604 case VREG: 1605 switch (com) { 1606 case FIONREAD: 1607 vn_lock(vp, LK_SHARED | LK_RETRY); 1608 error = VOP_GETATTR(vp, &vattr, active_cred); 1609 VOP_UNLOCK(vp); 1610 if (error == 0) 1611 *(int *)data = vattr.va_size - fp->f_offset; 1612 return (error); 1613 case FIOBMAP2: 1614 bmarg = (struct fiobmap2_arg *)data; 1615 vn_lock(vp, LK_SHARED | LK_RETRY); 1616 #ifdef MAC 1617 error = mac_vnode_check_read(active_cred, fp->f_cred, 1618 vp); 1619 if (error == 0) 1620 #endif 1621 error = VOP_BMAP(vp, bmarg->bn, NULL, 1622 &bmarg->bn, &bmarg->runp, &bmarg->runb); 1623 VOP_UNLOCK(vp); 1624 return (error); 1625 case FIONBIO: 1626 case FIOASYNC: 1627 return (0); 1628 default: 1629 return (VOP_IOCTL(vp, com, data, fp->f_flag, 1630 active_cred, td)); 1631 } 1632 break; 1633 case VCHR: 1634 return (VOP_IOCTL(vp, com, data, fp->f_flag, 1635 active_cred, td)); 1636 default: 1637 return (ENOTTY); 1638 } 1639 } 1640 1641 /* 1642 * File table vnode poll routine. 1643 */ 1644 static int 1645 vn_poll(struct file *fp, int events, struct ucred *active_cred, 1646 struct thread *td) 1647 { 1648 struct vnode *vp; 1649 int error; 1650 1651 vp = fp->f_vnode; 1652 #if defined(MAC) || defined(AUDIT) 1653 if (AUDITING_TD(td) || mac_vnode_check_poll_enabled()) { 1654 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1655 AUDIT_ARG_VNODE1(vp); 1656 error = mac_vnode_check_poll(active_cred, fp->f_cred, vp); 1657 VOP_UNLOCK(vp); 1658 if (error != 0) 1659 return (error); 1660 } 1661 #endif 1662 error = VOP_POLL(vp, events, fp->f_cred, td); 1663 return (error); 1664 } 1665 1666 /* 1667 * Acquire the requested lock and then check for validity. LK_RETRY 1668 * permits vn_lock to return doomed vnodes. 1669 */ 1670 static int __noinline 1671 _vn_lock_fallback(struct vnode *vp, int flags, const char *file, int line, 1672 int error) 1673 { 1674 1675 KASSERT((flags & LK_RETRY) == 0 || error == 0, 1676 ("vn_lock: error %d incompatible with flags %#x", error, flags)); 1677 1678 if (error == 0) 1679 VNASSERT(VN_IS_DOOMED(vp), vp, ("vnode not doomed")); 1680 1681 if ((flags & LK_RETRY) == 0) { 1682 if (error == 0) { 1683 VOP_UNLOCK(vp); 1684 error = ENOENT; 1685 } 1686 return (error); 1687 } 1688 1689 /* 1690 * LK_RETRY case. 1691 * 1692 * Nothing to do if we got the lock. 1693 */ 1694 if (error == 0) 1695 return (0); 1696 1697 /* 1698 * Interlock was dropped by the call in _vn_lock. 1699 */ 1700 flags &= ~LK_INTERLOCK; 1701 do { 1702 error = VOP_LOCK1(vp, flags, file, line); 1703 } while (error != 0); 1704 return (0); 1705 } 1706 1707 int 1708 _vn_lock(struct vnode *vp, int flags, const char *file, int line) 1709 { 1710 int error; 1711 1712 VNASSERT((flags & LK_TYPE_MASK) != 0, vp, 1713 ("vn_lock: no locktype (%d passed)", flags)); 1714 VNPASS(vp->v_holdcnt > 0, vp); 1715 error = VOP_LOCK1(vp, flags, file, line); 1716 if (__predict_false(error != 0 || VN_IS_DOOMED(vp))) 1717 return (_vn_lock_fallback(vp, flags, file, line, error)); 1718 return (0); 1719 } 1720 1721 /* 1722 * File table vnode close routine. 1723 */ 1724 static int 1725 vn_closefile(struct file *fp, struct thread *td) 1726 { 1727 struct vnode *vp; 1728 struct flock lf; 1729 int error; 1730 bool ref; 1731 1732 vp = fp->f_vnode; 1733 fp->f_ops = &badfileops; 1734 ref= (fp->f_flag & FHASLOCK) != 0 && fp->f_type == DTYPE_VNODE; 1735 1736 error = vn_close1(vp, fp->f_flag, fp->f_cred, td, ref); 1737 1738 if (__predict_false(ref)) { 1739 lf.l_whence = SEEK_SET; 1740 lf.l_start = 0; 1741 lf.l_len = 0; 1742 lf.l_type = F_UNLCK; 1743 (void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, F_FLOCK); 1744 vrele(vp); 1745 } 1746 return (error); 1747 } 1748 1749 /* 1750 * Preparing to start a filesystem write operation. If the operation is 1751 * permitted, then we bump the count of operations in progress and 1752 * proceed. If a suspend request is in progress, we wait until the 1753 * suspension is over, and then proceed. 1754 */ 1755 static int 1756 vn_start_write_refed(struct mount *mp, int flags, bool mplocked) 1757 { 1758 int error, mflags; 1759 1760 if (__predict_true(!mplocked) && (flags & V_XSLEEP) == 0 && 1761 vfs_op_thread_enter(mp)) { 1762 MPASS((mp->mnt_kern_flag & MNTK_SUSPEND) == 0); 1763 vfs_mp_count_add_pcpu(mp, writeopcount, 1); 1764 vfs_op_thread_exit(mp); 1765 return (0); 1766 } 1767 1768 if (mplocked) 1769 mtx_assert(MNT_MTX(mp), MA_OWNED); 1770 else 1771 MNT_ILOCK(mp); 1772 1773 error = 0; 1774 1775 /* 1776 * Check on status of suspension. 1777 */ 1778 if ((curthread->td_pflags & TDP_IGNSUSP) == 0 || 1779 mp->mnt_susp_owner != curthread) { 1780 mflags = ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0 ? 1781 (flags & PCATCH) : 0) | (PUSER - 1); 1782 while ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { 1783 if (flags & V_NOWAIT) { 1784 error = EWOULDBLOCK; 1785 goto unlock; 1786 } 1787 error = msleep(&mp->mnt_flag, MNT_MTX(mp), mflags, 1788 "suspfs", 0); 1789 if (error) 1790 goto unlock; 1791 } 1792 } 1793 if (flags & V_XSLEEP) 1794 goto unlock; 1795 mp->mnt_writeopcount++; 1796 unlock: 1797 if (error != 0 || (flags & V_XSLEEP) != 0) 1798 MNT_REL(mp); 1799 MNT_IUNLOCK(mp); 1800 return (error); 1801 } 1802 1803 int 1804 vn_start_write(struct vnode *vp, struct mount **mpp, int flags) 1805 { 1806 struct mount *mp; 1807 int error; 1808 1809 KASSERT((flags & V_MNTREF) == 0 || (*mpp != NULL && vp == NULL), 1810 ("V_MNTREF requires mp")); 1811 1812 error = 0; 1813 /* 1814 * If a vnode is provided, get and return the mount point that 1815 * to which it will write. 1816 */ 1817 if (vp != NULL) { 1818 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) { 1819 *mpp = NULL; 1820 if (error != EOPNOTSUPP) 1821 return (error); 1822 return (0); 1823 } 1824 } 1825 if ((mp = *mpp) == NULL) 1826 return (0); 1827 1828 /* 1829 * VOP_GETWRITEMOUNT() returns with the mp refcount held through 1830 * a vfs_ref(). 1831 * As long as a vnode is not provided we need to acquire a 1832 * refcount for the provided mountpoint too, in order to 1833 * emulate a vfs_ref(). 1834 */ 1835 if (vp == NULL && (flags & V_MNTREF) == 0) 1836 vfs_ref(mp); 1837 1838 return (vn_start_write_refed(mp, flags, false)); 1839 } 1840 1841 /* 1842 * Secondary suspension. Used by operations such as vop_inactive 1843 * routines that are needed by the higher level functions. These 1844 * are allowed to proceed until all the higher level functions have 1845 * completed (indicated by mnt_writeopcount dropping to zero). At that 1846 * time, these operations are halted until the suspension is over. 1847 */ 1848 int 1849 vn_start_secondary_write(struct vnode *vp, struct mount **mpp, int flags) 1850 { 1851 struct mount *mp; 1852 int error; 1853 1854 KASSERT((flags & V_MNTREF) == 0 || (*mpp != NULL && vp == NULL), 1855 ("V_MNTREF requires mp")); 1856 1857 retry: 1858 if (vp != NULL) { 1859 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) { 1860 *mpp = NULL; 1861 if (error != EOPNOTSUPP) 1862 return (error); 1863 return (0); 1864 } 1865 } 1866 /* 1867 * If we are not suspended or have not yet reached suspended 1868 * mode, then let the operation proceed. 1869 */ 1870 if ((mp = *mpp) == NULL) 1871 return (0); 1872 1873 /* 1874 * VOP_GETWRITEMOUNT() returns with the mp refcount held through 1875 * a vfs_ref(). 1876 * As long as a vnode is not provided we need to acquire a 1877 * refcount for the provided mountpoint too, in order to 1878 * emulate a vfs_ref(). 1879 */ 1880 MNT_ILOCK(mp); 1881 if (vp == NULL && (flags & V_MNTREF) == 0) 1882 MNT_REF(mp); 1883 if ((mp->mnt_kern_flag & (MNTK_SUSPENDED | MNTK_SUSPEND2)) == 0) { 1884 mp->mnt_secondary_writes++; 1885 mp->mnt_secondary_accwrites++; 1886 MNT_IUNLOCK(mp); 1887 return (0); 1888 } 1889 if (flags & V_NOWAIT) { 1890 MNT_REL(mp); 1891 MNT_IUNLOCK(mp); 1892 return (EWOULDBLOCK); 1893 } 1894 /* 1895 * Wait for the suspension to finish. 1896 */ 1897 error = msleep(&mp->mnt_flag, MNT_MTX(mp), (PUSER - 1) | PDROP | 1898 ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0 ? (flags & PCATCH) : 0), 1899 "suspfs", 0); 1900 vfs_rel(mp); 1901 if (error == 0) 1902 goto retry; 1903 return (error); 1904 } 1905 1906 /* 1907 * Filesystem write operation has completed. If we are suspending and this 1908 * operation is the last one, notify the suspender that the suspension is 1909 * now in effect. 1910 */ 1911 void 1912 vn_finished_write(struct mount *mp) 1913 { 1914 int c; 1915 1916 if (mp == NULL) 1917 return; 1918 1919 if (vfs_op_thread_enter(mp)) { 1920 vfs_mp_count_sub_pcpu(mp, writeopcount, 1); 1921 vfs_mp_count_sub_pcpu(mp, ref, 1); 1922 vfs_op_thread_exit(mp); 1923 return; 1924 } 1925 1926 MNT_ILOCK(mp); 1927 vfs_assert_mount_counters(mp); 1928 MNT_REL(mp); 1929 c = --mp->mnt_writeopcount; 1930 if (mp->mnt_vfs_ops == 0) { 1931 MPASS((mp->mnt_kern_flag & MNTK_SUSPEND) == 0); 1932 MNT_IUNLOCK(mp); 1933 return; 1934 } 1935 if (c < 0) 1936 vfs_dump_mount_counters(mp); 1937 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && c == 0) 1938 wakeup(&mp->mnt_writeopcount); 1939 MNT_IUNLOCK(mp); 1940 } 1941 1942 /* 1943 * Filesystem secondary write operation has completed. If we are 1944 * suspending and this operation is the last one, notify the suspender 1945 * that the suspension is now in effect. 1946 */ 1947 void 1948 vn_finished_secondary_write(struct mount *mp) 1949 { 1950 if (mp == NULL) 1951 return; 1952 MNT_ILOCK(mp); 1953 MNT_REL(mp); 1954 mp->mnt_secondary_writes--; 1955 if (mp->mnt_secondary_writes < 0) 1956 panic("vn_finished_secondary_write: neg cnt"); 1957 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && 1958 mp->mnt_secondary_writes <= 0) 1959 wakeup(&mp->mnt_secondary_writes); 1960 MNT_IUNLOCK(mp); 1961 } 1962 1963 /* 1964 * Request a filesystem to suspend write operations. 1965 */ 1966 int 1967 vfs_write_suspend(struct mount *mp, int flags) 1968 { 1969 int error; 1970 1971 vfs_op_enter(mp); 1972 1973 MNT_ILOCK(mp); 1974 vfs_assert_mount_counters(mp); 1975 if (mp->mnt_susp_owner == curthread) { 1976 vfs_op_exit_locked(mp); 1977 MNT_IUNLOCK(mp); 1978 return (EALREADY); 1979 } 1980 while (mp->mnt_kern_flag & MNTK_SUSPEND) 1981 msleep(&mp->mnt_flag, MNT_MTX(mp), PUSER - 1, "wsuspfs", 0); 1982 1983 /* 1984 * Unmount holds a write reference on the mount point. If we 1985 * own busy reference and drain for writers, we deadlock with 1986 * the reference draining in the unmount path. Callers of 1987 * vfs_write_suspend() must specify VS_SKIP_UNMOUNT if 1988 * vfs_busy() reference is owned and caller is not in the 1989 * unmount context. 1990 */ 1991 if ((flags & VS_SKIP_UNMOUNT) != 0 && 1992 (mp->mnt_kern_flag & MNTK_UNMOUNT) != 0) { 1993 vfs_op_exit_locked(mp); 1994 MNT_IUNLOCK(mp); 1995 return (EBUSY); 1996 } 1997 1998 mp->mnt_kern_flag |= MNTK_SUSPEND; 1999 mp->mnt_susp_owner = curthread; 2000 if (mp->mnt_writeopcount > 0) 2001 (void) msleep(&mp->mnt_writeopcount, 2002 MNT_MTX(mp), (PUSER - 1)|PDROP, "suspwt", 0); 2003 else 2004 MNT_IUNLOCK(mp); 2005 if ((error = VFS_SYNC(mp, MNT_SUSPEND)) != 0) { 2006 vfs_write_resume(mp, 0); 2007 /* vfs_write_resume does vfs_op_exit() for us */ 2008 } 2009 return (error); 2010 } 2011 2012 /* 2013 * Request a filesystem to resume write operations. 2014 */ 2015 void 2016 vfs_write_resume(struct mount *mp, int flags) 2017 { 2018 2019 MNT_ILOCK(mp); 2020 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { 2021 KASSERT(mp->mnt_susp_owner == curthread, ("mnt_susp_owner")); 2022 mp->mnt_kern_flag &= ~(MNTK_SUSPEND | MNTK_SUSPEND2 | 2023 MNTK_SUSPENDED); 2024 mp->mnt_susp_owner = NULL; 2025 wakeup(&mp->mnt_writeopcount); 2026 wakeup(&mp->mnt_flag); 2027 curthread->td_pflags &= ~TDP_IGNSUSP; 2028 if ((flags & VR_START_WRITE) != 0) { 2029 MNT_REF(mp); 2030 mp->mnt_writeopcount++; 2031 } 2032 MNT_IUNLOCK(mp); 2033 if ((flags & VR_NO_SUSPCLR) == 0) 2034 VFS_SUSP_CLEAN(mp); 2035 vfs_op_exit(mp); 2036 } else if ((flags & VR_START_WRITE) != 0) { 2037 MNT_REF(mp); 2038 vn_start_write_refed(mp, 0, true); 2039 } else { 2040 MNT_IUNLOCK(mp); 2041 } 2042 } 2043 2044 /* 2045 * Helper loop around vfs_write_suspend() for filesystem unmount VFS 2046 * methods. 2047 */ 2048 int 2049 vfs_write_suspend_umnt(struct mount *mp) 2050 { 2051 int error; 2052 2053 KASSERT((curthread->td_pflags & TDP_IGNSUSP) == 0, 2054 ("vfs_write_suspend_umnt: recursed")); 2055 2056 /* dounmount() already called vn_start_write(). */ 2057 for (;;) { 2058 vn_finished_write(mp); 2059 error = vfs_write_suspend(mp, 0); 2060 if (error != 0) { 2061 vn_start_write(NULL, &mp, V_WAIT); 2062 return (error); 2063 } 2064 MNT_ILOCK(mp); 2065 if ((mp->mnt_kern_flag & MNTK_SUSPENDED) != 0) 2066 break; 2067 MNT_IUNLOCK(mp); 2068 vn_start_write(NULL, &mp, V_WAIT); 2069 } 2070 mp->mnt_kern_flag &= ~(MNTK_SUSPENDED | MNTK_SUSPEND2); 2071 wakeup(&mp->mnt_flag); 2072 MNT_IUNLOCK(mp); 2073 curthread->td_pflags |= TDP_IGNSUSP; 2074 return (0); 2075 } 2076 2077 /* 2078 * Implement kqueues for files by translating it to vnode operation. 2079 */ 2080 static int 2081 vn_kqfilter(struct file *fp, struct knote *kn) 2082 { 2083 2084 return (VOP_KQFILTER(fp->f_vnode, kn)); 2085 } 2086 2087 /* 2088 * Simplified in-kernel wrapper calls for extended attribute access. 2089 * Both calls pass in a NULL credential, authorizing as "kernel" access. 2090 * Set IO_NODELOCKED in ioflg if the vnode is already locked. 2091 */ 2092 int 2093 vn_extattr_get(struct vnode *vp, int ioflg, int attrnamespace, 2094 const char *attrname, int *buflen, char *buf, struct thread *td) 2095 { 2096 struct uio auio; 2097 struct iovec iov; 2098 int error; 2099 2100 iov.iov_len = *buflen; 2101 iov.iov_base = buf; 2102 2103 auio.uio_iov = &iov; 2104 auio.uio_iovcnt = 1; 2105 auio.uio_rw = UIO_READ; 2106 auio.uio_segflg = UIO_SYSSPACE; 2107 auio.uio_td = td; 2108 auio.uio_offset = 0; 2109 auio.uio_resid = *buflen; 2110 2111 if ((ioflg & IO_NODELOCKED) == 0) 2112 vn_lock(vp, LK_SHARED | LK_RETRY); 2113 2114 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 2115 2116 /* authorize attribute retrieval as kernel */ 2117 error = VOP_GETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, NULL, 2118 td); 2119 2120 if ((ioflg & IO_NODELOCKED) == 0) 2121 VOP_UNLOCK(vp); 2122 2123 if (error == 0) { 2124 *buflen = *buflen - auio.uio_resid; 2125 } 2126 2127 return (error); 2128 } 2129 2130 /* 2131 * XXX failure mode if partially written? 2132 */ 2133 int 2134 vn_extattr_set(struct vnode *vp, int ioflg, int attrnamespace, 2135 const char *attrname, int buflen, char *buf, struct thread *td) 2136 { 2137 struct uio auio; 2138 struct iovec iov; 2139 struct mount *mp; 2140 int error; 2141 2142 iov.iov_len = buflen; 2143 iov.iov_base = buf; 2144 2145 auio.uio_iov = &iov; 2146 auio.uio_iovcnt = 1; 2147 auio.uio_rw = UIO_WRITE; 2148 auio.uio_segflg = UIO_SYSSPACE; 2149 auio.uio_td = td; 2150 auio.uio_offset = 0; 2151 auio.uio_resid = buflen; 2152 2153 if ((ioflg & IO_NODELOCKED) == 0) { 2154 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) 2155 return (error); 2156 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2157 } 2158 2159 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 2160 2161 /* authorize attribute setting as kernel */ 2162 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, td); 2163 2164 if ((ioflg & IO_NODELOCKED) == 0) { 2165 vn_finished_write(mp); 2166 VOP_UNLOCK(vp); 2167 } 2168 2169 return (error); 2170 } 2171 2172 int 2173 vn_extattr_rm(struct vnode *vp, int ioflg, int attrnamespace, 2174 const char *attrname, struct thread *td) 2175 { 2176 struct mount *mp; 2177 int error; 2178 2179 if ((ioflg & IO_NODELOCKED) == 0) { 2180 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) 2181 return (error); 2182 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2183 } 2184 2185 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 2186 2187 /* authorize attribute removal as kernel */ 2188 error = VOP_DELETEEXTATTR(vp, attrnamespace, attrname, NULL, td); 2189 if (error == EOPNOTSUPP) 2190 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, NULL, 2191 NULL, td); 2192 2193 if ((ioflg & IO_NODELOCKED) == 0) { 2194 vn_finished_write(mp); 2195 VOP_UNLOCK(vp); 2196 } 2197 2198 return (error); 2199 } 2200 2201 static int 2202 vn_get_ino_alloc_vget(struct mount *mp, void *arg, int lkflags, 2203 struct vnode **rvp) 2204 { 2205 2206 return (VFS_VGET(mp, *(ino_t *)arg, lkflags, rvp)); 2207 } 2208 2209 int 2210 vn_vget_ino(struct vnode *vp, ino_t ino, int lkflags, struct vnode **rvp) 2211 { 2212 2213 return (vn_vget_ino_gen(vp, vn_get_ino_alloc_vget, &ino, 2214 lkflags, rvp)); 2215 } 2216 2217 int 2218 vn_vget_ino_gen(struct vnode *vp, vn_get_ino_t alloc, void *alloc_arg, 2219 int lkflags, struct vnode **rvp) 2220 { 2221 struct mount *mp; 2222 int ltype, error; 2223 2224 ASSERT_VOP_LOCKED(vp, "vn_vget_ino_get"); 2225 mp = vp->v_mount; 2226 ltype = VOP_ISLOCKED(vp); 2227 KASSERT(ltype == LK_EXCLUSIVE || ltype == LK_SHARED, 2228 ("vn_vget_ino: vp not locked")); 2229 error = vfs_busy(mp, MBF_NOWAIT); 2230 if (error != 0) { 2231 vfs_ref(mp); 2232 VOP_UNLOCK(vp); 2233 error = vfs_busy(mp, 0); 2234 vn_lock(vp, ltype | LK_RETRY); 2235 vfs_rel(mp); 2236 if (error != 0) 2237 return (ENOENT); 2238 if (VN_IS_DOOMED(vp)) { 2239 vfs_unbusy(mp); 2240 return (ENOENT); 2241 } 2242 } 2243 VOP_UNLOCK(vp); 2244 error = alloc(mp, alloc_arg, lkflags, rvp); 2245 vfs_unbusy(mp); 2246 if (error != 0 || *rvp != vp) 2247 vn_lock(vp, ltype | LK_RETRY); 2248 if (VN_IS_DOOMED(vp)) { 2249 if (error == 0) { 2250 if (*rvp == vp) 2251 vunref(vp); 2252 else 2253 vput(*rvp); 2254 } 2255 error = ENOENT; 2256 } 2257 return (error); 2258 } 2259 2260 int 2261 vn_rlimit_fsize(const struct vnode *vp, const struct uio *uio, 2262 struct thread *td) 2263 { 2264 2265 if (vp->v_type != VREG || td == NULL) 2266 return (0); 2267 if ((uoff_t)uio->uio_offset + uio->uio_resid > 2268 lim_cur(td, RLIMIT_FSIZE)) { 2269 PROC_LOCK(td->td_proc); 2270 kern_psignal(td->td_proc, SIGXFSZ); 2271 PROC_UNLOCK(td->td_proc); 2272 return (EFBIG); 2273 } 2274 return (0); 2275 } 2276 2277 int 2278 vn_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 2279 struct thread *td) 2280 { 2281 struct vnode *vp; 2282 2283 vp = fp->f_vnode; 2284 #ifdef AUDIT 2285 vn_lock(vp, LK_SHARED | LK_RETRY); 2286 AUDIT_ARG_VNODE1(vp); 2287 VOP_UNLOCK(vp); 2288 #endif 2289 return (setfmode(td, active_cred, vp, mode)); 2290 } 2291 2292 int 2293 vn_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 2294 struct thread *td) 2295 { 2296 struct vnode *vp; 2297 2298 vp = fp->f_vnode; 2299 #ifdef AUDIT 2300 vn_lock(vp, LK_SHARED | LK_RETRY); 2301 AUDIT_ARG_VNODE1(vp); 2302 VOP_UNLOCK(vp); 2303 #endif 2304 return (setfown(td, active_cred, vp, uid, gid)); 2305 } 2306 2307 void 2308 vn_pages_remove(struct vnode *vp, vm_pindex_t start, vm_pindex_t end) 2309 { 2310 vm_object_t object; 2311 2312 if ((object = vp->v_object) == NULL) 2313 return; 2314 VM_OBJECT_WLOCK(object); 2315 vm_object_page_remove(object, start, end, 0); 2316 VM_OBJECT_WUNLOCK(object); 2317 } 2318 2319 int 2320 vn_bmap_seekhole(struct vnode *vp, u_long cmd, off_t *off, struct ucred *cred) 2321 { 2322 struct vattr va; 2323 daddr_t bn, bnp; 2324 uint64_t bsize; 2325 off_t noff; 2326 int error; 2327 2328 KASSERT(cmd == FIOSEEKHOLE || cmd == FIOSEEKDATA, 2329 ("Wrong command %lu", cmd)); 2330 2331 if (vn_lock(vp, LK_SHARED) != 0) 2332 return (EBADF); 2333 if (vp->v_type != VREG) { 2334 error = ENOTTY; 2335 goto unlock; 2336 } 2337 error = VOP_GETATTR(vp, &va, cred); 2338 if (error != 0) 2339 goto unlock; 2340 noff = *off; 2341 if (noff >= va.va_size) { 2342 error = ENXIO; 2343 goto unlock; 2344 } 2345 bsize = vp->v_mount->mnt_stat.f_iosize; 2346 for (bn = noff / bsize; noff < va.va_size; bn++, noff += bsize - 2347 noff % bsize) { 2348 error = VOP_BMAP(vp, bn, NULL, &bnp, NULL, NULL); 2349 if (error == EOPNOTSUPP) { 2350 error = ENOTTY; 2351 goto unlock; 2352 } 2353 if ((bnp == -1 && cmd == FIOSEEKHOLE) || 2354 (bnp != -1 && cmd == FIOSEEKDATA)) { 2355 noff = bn * bsize; 2356 if (noff < *off) 2357 noff = *off; 2358 goto unlock; 2359 } 2360 } 2361 if (noff > va.va_size) 2362 noff = va.va_size; 2363 /* noff == va.va_size. There is an implicit hole at the end of file. */ 2364 if (cmd == FIOSEEKDATA) 2365 error = ENXIO; 2366 unlock: 2367 VOP_UNLOCK(vp); 2368 if (error == 0) 2369 *off = noff; 2370 return (error); 2371 } 2372 2373 int 2374 vn_seek(struct file *fp, off_t offset, int whence, struct thread *td) 2375 { 2376 struct ucred *cred; 2377 struct vnode *vp; 2378 struct vattr vattr; 2379 off_t foffset, size; 2380 int error, noneg; 2381 2382 cred = td->td_ucred; 2383 vp = fp->f_vnode; 2384 foffset = foffset_lock(fp, 0); 2385 noneg = (vp->v_type != VCHR); 2386 error = 0; 2387 switch (whence) { 2388 case L_INCR: 2389 if (noneg && 2390 (foffset < 0 || 2391 (offset > 0 && foffset > OFF_MAX - offset))) { 2392 error = EOVERFLOW; 2393 break; 2394 } 2395 offset += foffset; 2396 break; 2397 case L_XTND: 2398 vn_lock(vp, LK_SHARED | LK_RETRY); 2399 error = VOP_GETATTR(vp, &vattr, cred); 2400 VOP_UNLOCK(vp); 2401 if (error) 2402 break; 2403 2404 /* 2405 * If the file references a disk device, then fetch 2406 * the media size and use that to determine the ending 2407 * offset. 2408 */ 2409 if (vattr.va_size == 0 && vp->v_type == VCHR && 2410 fo_ioctl(fp, DIOCGMEDIASIZE, &size, cred, td) == 0) 2411 vattr.va_size = size; 2412 if (noneg && 2413 (vattr.va_size > OFF_MAX || 2414 (offset > 0 && vattr.va_size > OFF_MAX - offset))) { 2415 error = EOVERFLOW; 2416 break; 2417 } 2418 offset += vattr.va_size; 2419 break; 2420 case L_SET: 2421 break; 2422 case SEEK_DATA: 2423 error = fo_ioctl(fp, FIOSEEKDATA, &offset, cred, td); 2424 if (error == ENOTTY) 2425 error = EINVAL; 2426 break; 2427 case SEEK_HOLE: 2428 error = fo_ioctl(fp, FIOSEEKHOLE, &offset, cred, td); 2429 if (error == ENOTTY) 2430 error = EINVAL; 2431 break; 2432 default: 2433 error = EINVAL; 2434 } 2435 if (error == 0 && noneg && offset < 0) 2436 error = EINVAL; 2437 if (error != 0) 2438 goto drop; 2439 VFS_KNOTE_UNLOCKED(vp, 0); 2440 td->td_uretoff.tdu_off = offset; 2441 drop: 2442 foffset_unlock(fp, offset, error != 0 ? FOF_NOUPDATE : 0); 2443 return (error); 2444 } 2445 2446 int 2447 vn_utimes_perm(struct vnode *vp, struct vattr *vap, struct ucred *cred, 2448 struct thread *td) 2449 { 2450 int error; 2451 2452 /* 2453 * Grant permission if the caller is the owner of the file, or 2454 * the super-user, or has ACL_WRITE_ATTRIBUTES permission on 2455 * on the file. If the time pointer is null, then write 2456 * permission on the file is also sufficient. 2457 * 2458 * From NFSv4.1, draft 21, 6.2.1.3.1, Discussion of Mask Attributes: 2459 * A user having ACL_WRITE_DATA or ACL_WRITE_ATTRIBUTES 2460 * will be allowed to set the times [..] to the current 2461 * server time. 2462 */ 2463 error = VOP_ACCESSX(vp, VWRITE_ATTRIBUTES, cred, td); 2464 if (error != 0 && (vap->va_vaflags & VA_UTIMES_NULL) != 0) 2465 error = VOP_ACCESS(vp, VWRITE, cred, td); 2466 return (error); 2467 } 2468 2469 int 2470 vn_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 2471 { 2472 struct vnode *vp; 2473 int error; 2474 2475 if (fp->f_type == DTYPE_FIFO) 2476 kif->kf_type = KF_TYPE_FIFO; 2477 else 2478 kif->kf_type = KF_TYPE_VNODE; 2479 vp = fp->f_vnode; 2480 vref(vp); 2481 FILEDESC_SUNLOCK(fdp); 2482 error = vn_fill_kinfo_vnode(vp, kif); 2483 vrele(vp); 2484 FILEDESC_SLOCK(fdp); 2485 return (error); 2486 } 2487 2488 static inline void 2489 vn_fill_junk(struct kinfo_file *kif) 2490 { 2491 size_t len, olen; 2492 2493 /* 2494 * Simulate vn_fullpath returning changing values for a given 2495 * vp during e.g. coredump. 2496 */ 2497 len = (arc4random() % (sizeof(kif->kf_path) - 2)) + 1; 2498 olen = strlen(kif->kf_path); 2499 if (len < olen) 2500 strcpy(&kif->kf_path[len - 1], "$"); 2501 else 2502 for (; olen < len; olen++) 2503 strcpy(&kif->kf_path[olen], "A"); 2504 } 2505 2506 int 2507 vn_fill_kinfo_vnode(struct vnode *vp, struct kinfo_file *kif) 2508 { 2509 struct vattr va; 2510 char *fullpath, *freepath; 2511 int error; 2512 2513 kif->kf_un.kf_file.kf_file_type = vntype_to_kinfo(vp->v_type); 2514 freepath = NULL; 2515 fullpath = "-"; 2516 error = vn_fullpath(vp, &fullpath, &freepath); 2517 if (error == 0) { 2518 strlcpy(kif->kf_path, fullpath, sizeof(kif->kf_path)); 2519 } 2520 if (freepath != NULL) 2521 free(freepath, M_TEMP); 2522 2523 KFAIL_POINT_CODE(DEBUG_FP, fill_kinfo_vnode__random_path, 2524 vn_fill_junk(kif); 2525 ); 2526 2527 /* 2528 * Retrieve vnode attributes. 2529 */ 2530 va.va_fsid = VNOVAL; 2531 va.va_rdev = NODEV; 2532 vn_lock(vp, LK_SHARED | LK_RETRY); 2533 error = VOP_GETATTR(vp, &va, curthread->td_ucred); 2534 VOP_UNLOCK(vp); 2535 if (error != 0) 2536 return (error); 2537 if (va.va_fsid != VNOVAL) 2538 kif->kf_un.kf_file.kf_file_fsid = va.va_fsid; 2539 else 2540 kif->kf_un.kf_file.kf_file_fsid = 2541 vp->v_mount->mnt_stat.f_fsid.val[0]; 2542 kif->kf_un.kf_file.kf_file_fsid_freebsd11 = 2543 kif->kf_un.kf_file.kf_file_fsid; /* truncate */ 2544 kif->kf_un.kf_file.kf_file_fileid = va.va_fileid; 2545 kif->kf_un.kf_file.kf_file_mode = MAKEIMODE(va.va_type, va.va_mode); 2546 kif->kf_un.kf_file.kf_file_size = va.va_size; 2547 kif->kf_un.kf_file.kf_file_rdev = va.va_rdev; 2548 kif->kf_un.kf_file.kf_file_rdev_freebsd11 = 2549 kif->kf_un.kf_file.kf_file_rdev; /* truncate */ 2550 return (0); 2551 } 2552 2553 int 2554 vn_mmap(struct file *fp, vm_map_t map, vm_offset_t *addr, vm_size_t size, 2555 vm_prot_t prot, vm_prot_t cap_maxprot, int flags, vm_ooffset_t foff, 2556 struct thread *td) 2557 { 2558 #ifdef HWPMC_HOOKS 2559 struct pmckern_map_in pkm; 2560 #endif 2561 struct mount *mp; 2562 struct vnode *vp; 2563 vm_object_t object; 2564 vm_prot_t maxprot; 2565 boolean_t writecounted; 2566 int error; 2567 2568 #if defined(COMPAT_FREEBSD7) || defined(COMPAT_FREEBSD6) || \ 2569 defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4) 2570 /* 2571 * POSIX shared-memory objects are defined to have 2572 * kernel persistence, and are not defined to support 2573 * read(2)/write(2) -- or even open(2). Thus, we can 2574 * use MAP_ASYNC to trade on-disk coherence for speed. 2575 * The shm_open(3) library routine turns on the FPOSIXSHM 2576 * flag to request this behavior. 2577 */ 2578 if ((fp->f_flag & FPOSIXSHM) != 0) 2579 flags |= MAP_NOSYNC; 2580 #endif 2581 vp = fp->f_vnode; 2582 2583 /* 2584 * Ensure that file and memory protections are 2585 * compatible. Note that we only worry about 2586 * writability if mapping is shared; in this case, 2587 * current and max prot are dictated by the open file. 2588 * XXX use the vnode instead? Problem is: what 2589 * credentials do we use for determination? What if 2590 * proc does a setuid? 2591 */ 2592 mp = vp->v_mount; 2593 if (mp != NULL && (mp->mnt_flag & MNT_NOEXEC) != 0) { 2594 maxprot = VM_PROT_NONE; 2595 if ((prot & VM_PROT_EXECUTE) != 0) 2596 return (EACCES); 2597 } else 2598 maxprot = VM_PROT_EXECUTE; 2599 if ((fp->f_flag & FREAD) != 0) 2600 maxprot |= VM_PROT_READ; 2601 else if ((prot & VM_PROT_READ) != 0) 2602 return (EACCES); 2603 2604 /* 2605 * If we are sharing potential changes via MAP_SHARED and we 2606 * are trying to get write permission although we opened it 2607 * without asking for it, bail out. 2608 */ 2609 if ((flags & MAP_SHARED) != 0) { 2610 if ((fp->f_flag & FWRITE) != 0) 2611 maxprot |= VM_PROT_WRITE; 2612 else if ((prot & VM_PROT_WRITE) != 0) 2613 return (EACCES); 2614 } else { 2615 maxprot |= VM_PROT_WRITE; 2616 cap_maxprot |= VM_PROT_WRITE; 2617 } 2618 maxprot &= cap_maxprot; 2619 2620 /* 2621 * For regular files and shared memory, POSIX requires that 2622 * the value of foff be a legitimate offset within the data 2623 * object. In particular, negative offsets are invalid. 2624 * Blocking negative offsets and overflows here avoids 2625 * possible wraparound or user-level access into reserved 2626 * ranges of the data object later. In contrast, POSIX does 2627 * not dictate how offsets are used by device drivers, so in 2628 * the case of a device mapping a negative offset is passed 2629 * on. 2630 */ 2631 if ( 2632 #ifdef _LP64 2633 size > OFF_MAX || 2634 #endif 2635 foff < 0 || foff > OFF_MAX - size) 2636 return (EINVAL); 2637 2638 writecounted = FALSE; 2639 error = vm_mmap_vnode(td, size, prot, &maxprot, &flags, vp, 2640 &foff, &object, &writecounted); 2641 if (error != 0) 2642 return (error); 2643 error = vm_mmap_object(map, addr, size, prot, maxprot, flags, object, 2644 foff, writecounted, td); 2645 if (error != 0) { 2646 /* 2647 * If this mapping was accounted for in the vnode's 2648 * writecount, then undo that now. 2649 */ 2650 if (writecounted) 2651 vm_pager_release_writecount(object, 0, size); 2652 vm_object_deallocate(object); 2653 } 2654 #ifdef HWPMC_HOOKS 2655 /* Inform hwpmc(4) if an executable is being mapped. */ 2656 if (PMC_HOOK_INSTALLED(PMC_FN_MMAP)) { 2657 if ((prot & VM_PROT_EXECUTE) != 0 && error == 0) { 2658 pkm.pm_file = vp; 2659 pkm.pm_address = (uintptr_t) *addr; 2660 PMC_CALL_HOOK_UNLOCKED(td, PMC_FN_MMAP, (void *) &pkm); 2661 } 2662 } 2663 #endif 2664 return (error); 2665 } 2666 2667 void 2668 vn_fsid(struct vnode *vp, struct vattr *va) 2669 { 2670 fsid_t *f; 2671 2672 f = &vp->v_mount->mnt_stat.f_fsid; 2673 va->va_fsid = (uint32_t)f->val[1]; 2674 va->va_fsid <<= sizeof(f->val[1]) * NBBY; 2675 va->va_fsid += (uint32_t)f->val[0]; 2676 } 2677 2678 int 2679 vn_fsync_buf(struct vnode *vp, int waitfor) 2680 { 2681 struct buf *bp, *nbp; 2682 struct bufobj *bo; 2683 struct mount *mp; 2684 int error, maxretry; 2685 2686 error = 0; 2687 maxretry = 10000; /* large, arbitrarily chosen */ 2688 mp = NULL; 2689 if (vp->v_type == VCHR) { 2690 VI_LOCK(vp); 2691 mp = vp->v_rdev->si_mountpt; 2692 VI_UNLOCK(vp); 2693 } 2694 bo = &vp->v_bufobj; 2695 BO_LOCK(bo); 2696 loop1: 2697 /* 2698 * MARK/SCAN initialization to avoid infinite loops. 2699 */ 2700 TAILQ_FOREACH(bp, &bo->bo_dirty.bv_hd, b_bobufs) { 2701 bp->b_vflags &= ~BV_SCANNED; 2702 bp->b_error = 0; 2703 } 2704 2705 /* 2706 * Flush all dirty buffers associated with a vnode. 2707 */ 2708 loop2: 2709 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 2710 if ((bp->b_vflags & BV_SCANNED) != 0) 2711 continue; 2712 bp->b_vflags |= BV_SCANNED; 2713 if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT, NULL)) { 2714 if (waitfor != MNT_WAIT) 2715 continue; 2716 if (BUF_LOCK(bp, 2717 LK_EXCLUSIVE | LK_INTERLOCK | LK_SLEEPFAIL, 2718 BO_LOCKPTR(bo)) != 0) { 2719 BO_LOCK(bo); 2720 goto loop1; 2721 } 2722 BO_LOCK(bo); 2723 } 2724 BO_UNLOCK(bo); 2725 KASSERT(bp->b_bufobj == bo, 2726 ("bp %p wrong b_bufobj %p should be %p", 2727 bp, bp->b_bufobj, bo)); 2728 if ((bp->b_flags & B_DELWRI) == 0) 2729 panic("fsync: not dirty"); 2730 if ((vp->v_object != NULL) && (bp->b_flags & B_CLUSTEROK)) { 2731 vfs_bio_awrite(bp); 2732 } else { 2733 bremfree(bp); 2734 bawrite(bp); 2735 } 2736 if (maxretry < 1000) 2737 pause("dirty", hz < 1000 ? 1 : hz / 1000); 2738 BO_LOCK(bo); 2739 goto loop2; 2740 } 2741 2742 /* 2743 * If synchronous the caller expects us to completely resolve all 2744 * dirty buffers in the system. Wait for in-progress I/O to 2745 * complete (which could include background bitmap writes), then 2746 * retry if dirty blocks still exist. 2747 */ 2748 if (waitfor == MNT_WAIT) { 2749 bufobj_wwait(bo, 0, 0); 2750 if (bo->bo_dirty.bv_cnt > 0) { 2751 /* 2752 * If we are unable to write any of these buffers 2753 * then we fail now rather than trying endlessly 2754 * to write them out. 2755 */ 2756 TAILQ_FOREACH(bp, &bo->bo_dirty.bv_hd, b_bobufs) 2757 if ((error = bp->b_error) != 0) 2758 break; 2759 if ((mp != NULL && mp->mnt_secondary_writes > 0) || 2760 (error == 0 && --maxretry >= 0)) 2761 goto loop1; 2762 if (error == 0) 2763 error = EAGAIN; 2764 } 2765 } 2766 BO_UNLOCK(bo); 2767 if (error != 0) 2768 vn_printf(vp, "fsync: giving up on dirty (error = %d) ", error); 2769 2770 return (error); 2771 } 2772 2773 /* 2774 * Copies a byte range from invp to outvp. Calls VOP_COPY_FILE_RANGE() 2775 * or vn_generic_copy_file_range() after rangelocking the byte ranges, 2776 * to do the actual copy. 2777 * vn_generic_copy_file_range() is factored out, so it can be called 2778 * from a VOP_COPY_FILE_RANGE() call as well, but handles vnodes from 2779 * different file systems. 2780 */ 2781 int 2782 vn_copy_file_range(struct vnode *invp, off_t *inoffp, struct vnode *outvp, 2783 off_t *outoffp, size_t *lenp, unsigned int flags, struct ucred *incred, 2784 struct ucred *outcred, struct thread *fsize_td) 2785 { 2786 int error; 2787 size_t len; 2788 uint64_t uvalin, uvalout; 2789 2790 len = *lenp; 2791 *lenp = 0; /* For error returns. */ 2792 error = 0; 2793 2794 /* Do some sanity checks on the arguments. */ 2795 uvalin = *inoffp; 2796 uvalin += len; 2797 uvalout = *outoffp; 2798 uvalout += len; 2799 if (invp->v_type == VDIR || outvp->v_type == VDIR) 2800 error = EISDIR; 2801 else if (*inoffp < 0 || uvalin > INT64_MAX || uvalin < 2802 (uint64_t)*inoffp || *outoffp < 0 || uvalout > INT64_MAX || 2803 uvalout < (uint64_t)*outoffp || invp->v_type != VREG || 2804 outvp->v_type != VREG) 2805 error = EINVAL; 2806 if (error != 0) 2807 goto out; 2808 2809 /* 2810 * If the two vnode are for the same file system, call 2811 * VOP_COPY_FILE_RANGE(), otherwise call vn_generic_copy_file_range() 2812 * which can handle copies across multiple file systems. 2813 */ 2814 *lenp = len; 2815 if (invp->v_mount == outvp->v_mount) 2816 error = VOP_COPY_FILE_RANGE(invp, inoffp, outvp, outoffp, 2817 lenp, flags, incred, outcred, fsize_td); 2818 else 2819 error = vn_generic_copy_file_range(invp, inoffp, outvp, 2820 outoffp, lenp, flags, incred, outcred, fsize_td); 2821 out: 2822 return (error); 2823 } 2824 2825 /* 2826 * Test len bytes of data starting at dat for all bytes == 0. 2827 * Return true if all bytes are zero, false otherwise. 2828 * Expects dat to be well aligned. 2829 */ 2830 static bool 2831 mem_iszero(void *dat, int len) 2832 { 2833 int i; 2834 const u_int *p; 2835 const char *cp; 2836 2837 for (p = dat; len > 0; len -= sizeof(*p), p++) { 2838 if (len >= sizeof(*p)) { 2839 if (*p != 0) 2840 return (false); 2841 } else { 2842 cp = (const char *)p; 2843 for (i = 0; i < len; i++, cp++) 2844 if (*cp != '\0') 2845 return (false); 2846 } 2847 } 2848 return (true); 2849 } 2850 2851 /* 2852 * Look for a hole in the output file and, if found, adjust *outoffp 2853 * and *xferp to skip past the hole. 2854 * *xferp is the entire hole length to be written and xfer2 is how many bytes 2855 * to be written as 0's upon return. 2856 */ 2857 static off_t 2858 vn_skip_hole(struct vnode *outvp, off_t xfer2, off_t *outoffp, off_t *xferp, 2859 off_t *dataoffp, off_t *holeoffp, struct ucred *cred) 2860 { 2861 int error; 2862 off_t delta; 2863 2864 if (*holeoffp == 0 || *holeoffp <= *outoffp) { 2865 *dataoffp = *outoffp; 2866 error = VOP_IOCTL(outvp, FIOSEEKDATA, dataoffp, 0, cred, 2867 curthread); 2868 if (error == 0) { 2869 *holeoffp = *dataoffp; 2870 error = VOP_IOCTL(outvp, FIOSEEKHOLE, holeoffp, 0, cred, 2871 curthread); 2872 } 2873 if (error != 0 || *holeoffp == *dataoffp) { 2874 /* 2875 * Since outvp is unlocked, it may be possible for 2876 * another thread to do a truncate(), lseek(), write() 2877 * creating a hole at startoff between the above 2878 * VOP_IOCTL() calls, if the other thread does not do 2879 * rangelocking. 2880 * If that happens, *holeoffp == *dataoffp and finding 2881 * the hole has failed, so disable vn_skip_hole(). 2882 */ 2883 *holeoffp = -1; /* Disable use of vn_skip_hole(). */ 2884 return (xfer2); 2885 } 2886 KASSERT(*dataoffp >= *outoffp, 2887 ("vn_skip_hole: dataoff=%jd < outoff=%jd", 2888 (intmax_t)*dataoffp, (intmax_t)*outoffp)); 2889 KASSERT(*holeoffp > *dataoffp, 2890 ("vn_skip_hole: holeoff=%jd <= dataoff=%jd", 2891 (intmax_t)*holeoffp, (intmax_t)*dataoffp)); 2892 } 2893 2894 /* 2895 * If there is a hole before the data starts, advance *outoffp and 2896 * *xferp past the hole. 2897 */ 2898 if (*dataoffp > *outoffp) { 2899 delta = *dataoffp - *outoffp; 2900 if (delta >= *xferp) { 2901 /* Entire *xferp is a hole. */ 2902 *outoffp += *xferp; 2903 *xferp = 0; 2904 return (0); 2905 } 2906 *xferp -= delta; 2907 *outoffp += delta; 2908 xfer2 = MIN(xfer2, *xferp); 2909 } 2910 2911 /* 2912 * If a hole starts before the end of this xfer2, reduce this xfer2 so 2913 * that the write ends at the start of the hole. 2914 * *holeoffp should always be greater than *outoffp, but for the 2915 * non-INVARIANTS case, check this to make sure xfer2 remains a sane 2916 * value. 2917 */ 2918 if (*holeoffp > *outoffp && *holeoffp < *outoffp + xfer2) 2919 xfer2 = *holeoffp - *outoffp; 2920 return (xfer2); 2921 } 2922 2923 /* 2924 * Write an xfer sized chunk to outvp in blksize blocks from dat. 2925 * dat is a maximum of blksize in length and can be written repeatedly in 2926 * the chunk. 2927 * If growfile == true, just grow the file via vn_truncate_locked() instead 2928 * of doing actual writes. 2929 * If checkhole == true, a hole is being punched, so skip over any hole 2930 * already in the output file. 2931 */ 2932 static int 2933 vn_write_outvp(struct vnode *outvp, char *dat, off_t outoff, off_t xfer, 2934 u_long blksize, bool growfile, bool checkhole, struct ucred *cred) 2935 { 2936 struct mount *mp; 2937 off_t dataoff, holeoff, xfer2; 2938 int error, lckf; 2939 2940 /* 2941 * Loop around doing writes of blksize until write has been completed. 2942 * Lock/unlock on each loop iteration so that a bwillwrite() can be 2943 * done for each iteration, since the xfer argument can be very 2944 * large if there is a large hole to punch in the output file. 2945 */ 2946 error = 0; 2947 holeoff = 0; 2948 do { 2949 xfer2 = MIN(xfer, blksize); 2950 if (checkhole) { 2951 /* 2952 * Punching a hole. Skip writing if there is 2953 * already a hole in the output file. 2954 */ 2955 xfer2 = vn_skip_hole(outvp, xfer2, &outoff, &xfer, 2956 &dataoff, &holeoff, cred); 2957 if (xfer == 0) 2958 break; 2959 if (holeoff < 0) 2960 checkhole = false; 2961 KASSERT(xfer2 > 0, ("vn_write_outvp: xfer2=%jd", 2962 (intmax_t)xfer2)); 2963 } 2964 bwillwrite(); 2965 mp = NULL; 2966 error = vn_start_write(outvp, &mp, V_WAIT); 2967 if (error == 0) { 2968 if (MNT_SHARED_WRITES(mp)) 2969 lckf = LK_SHARED; 2970 else 2971 lckf = LK_EXCLUSIVE; 2972 error = vn_lock(outvp, lckf); 2973 } 2974 if (error == 0) { 2975 if (growfile) 2976 error = vn_truncate_locked(outvp, outoff + xfer, 2977 false, cred); 2978 else { 2979 error = vn_rdwr(UIO_WRITE, outvp, dat, xfer2, 2980 outoff, UIO_SYSSPACE, IO_NODELOCKED, 2981 curthread->td_ucred, cred, NULL, curthread); 2982 outoff += xfer2; 2983 xfer -= xfer2; 2984 } 2985 VOP_UNLOCK(outvp); 2986 } 2987 if (mp != NULL) 2988 vn_finished_write(mp); 2989 } while (!growfile && xfer > 0 && error == 0); 2990 return (error); 2991 } 2992 2993 /* 2994 * Copy a byte range of one file to another. This function can handle the 2995 * case where invp and outvp are on different file systems. 2996 * It can also be called by a VOP_COPY_FILE_RANGE() to do the work, if there 2997 * is no better file system specific way to do it. 2998 */ 2999 int 3000 vn_generic_copy_file_range(struct vnode *invp, off_t *inoffp, 3001 struct vnode *outvp, off_t *outoffp, size_t *lenp, unsigned int flags, 3002 struct ucred *incred, struct ucred *outcred, struct thread *fsize_td) 3003 { 3004 struct vattr va; 3005 struct mount *mp; 3006 struct uio io; 3007 off_t startoff, endoff, xfer, xfer2; 3008 u_long blksize; 3009 int error; 3010 bool cantseek, readzeros, eof, lastblock; 3011 ssize_t aresid; 3012 size_t copylen, len, savlen; 3013 char *dat; 3014 long holein, holeout; 3015 3016 holein = holeout = 0; 3017 savlen = len = *lenp; 3018 error = 0; 3019 dat = NULL; 3020 3021 error = vn_lock(invp, LK_SHARED); 3022 if (error != 0) 3023 goto out; 3024 if (VOP_PATHCONF(invp, _PC_MIN_HOLE_SIZE, &holein) != 0) 3025 holein = 0; 3026 VOP_UNLOCK(invp); 3027 3028 mp = NULL; 3029 error = vn_start_write(outvp, &mp, V_WAIT); 3030 if (error == 0) 3031 error = vn_lock(outvp, LK_EXCLUSIVE); 3032 if (error == 0) { 3033 /* 3034 * If fsize_td != NULL, do a vn_rlimit_fsize() call, 3035 * now that outvp is locked. 3036 */ 3037 if (fsize_td != NULL) { 3038 io.uio_offset = *outoffp; 3039 io.uio_resid = len; 3040 error = vn_rlimit_fsize(outvp, &io, fsize_td); 3041 if (error != 0) 3042 error = EFBIG; 3043 } 3044 if (VOP_PATHCONF(outvp, _PC_MIN_HOLE_SIZE, &holeout) != 0) 3045 holeout = 0; 3046 /* 3047 * Holes that are past EOF do not need to be written as a block 3048 * of zero bytes. So, truncate the output file as far as 3049 * possible and then use va.va_size to decide if writing 0 3050 * bytes is necessary in the loop below. 3051 */ 3052 if (error == 0) 3053 error = VOP_GETATTR(outvp, &va, outcred); 3054 if (error == 0 && va.va_size > *outoffp && va.va_size <= 3055 *outoffp + len) { 3056 #ifdef MAC 3057 error = mac_vnode_check_write(curthread->td_ucred, 3058 outcred, outvp); 3059 if (error == 0) 3060 #endif 3061 error = vn_truncate_locked(outvp, *outoffp, 3062 false, outcred); 3063 if (error == 0) 3064 va.va_size = *outoffp; 3065 } 3066 VOP_UNLOCK(outvp); 3067 } 3068 if (mp != NULL) 3069 vn_finished_write(mp); 3070 if (error != 0) 3071 goto out; 3072 3073 /* 3074 * Set the blksize to the larger of the hole sizes for invp and outvp. 3075 * If hole sizes aren't available, set the blksize to the larger 3076 * f_iosize of invp and outvp. 3077 * This code expects the hole sizes and f_iosizes to be powers of 2. 3078 * This value is clipped at 4Kbytes and 1Mbyte. 3079 */ 3080 blksize = MAX(holein, holeout); 3081 if (blksize == 0) 3082 blksize = MAX(invp->v_mount->mnt_stat.f_iosize, 3083 outvp->v_mount->mnt_stat.f_iosize); 3084 if (blksize < 4096) 3085 blksize = 4096; 3086 else if (blksize > 1024 * 1024) 3087 blksize = 1024 * 1024; 3088 dat = malloc(blksize, M_TEMP, M_WAITOK); 3089 3090 /* 3091 * If VOP_IOCTL(FIOSEEKHOLE) works for invp, use it and FIOSEEKDATA 3092 * to find holes. Otherwise, just scan the read block for all 0s 3093 * in the inner loop where the data copying is done. 3094 * Note that some file systems such as NFSv3, NFSv4.0 and NFSv4.1 may 3095 * support holes on the server, but do not support FIOSEEKHOLE. 3096 */ 3097 eof = false; 3098 while (len > 0 && error == 0 && !eof) { 3099 endoff = 0; /* To shut up compilers. */ 3100 cantseek = true; 3101 startoff = *inoffp; 3102 copylen = len; 3103 3104 /* 3105 * Find the next data area. If there is just a hole to EOF, 3106 * FIOSEEKDATA should fail and then we drop down into the 3107 * inner loop and create the hole on the outvp file. 3108 * (I do not know if any file system will report a hole to 3109 * EOF via FIOSEEKHOLE, but I am pretty sure FIOSEEKDATA 3110 * will fail for those file systems.) 3111 * 3112 * For input files that don't support FIOSEEKDATA/FIOSEEKHOLE, 3113 * the code just falls through to the inner copy loop. 3114 */ 3115 error = EINVAL; 3116 if (holein > 0) 3117 error = VOP_IOCTL(invp, FIOSEEKDATA, &startoff, 0, 3118 incred, curthread); 3119 if (error == 0) { 3120 endoff = startoff; 3121 error = VOP_IOCTL(invp, FIOSEEKHOLE, &endoff, 0, 3122 incred, curthread); 3123 /* 3124 * Since invp is unlocked, it may be possible for 3125 * another thread to do a truncate(), lseek(), write() 3126 * creating a hole at startoff between the above 3127 * VOP_IOCTL() calls, if the other thread does not do 3128 * rangelocking. 3129 * If that happens, startoff == endoff and finding 3130 * the hole has failed, so set an error. 3131 */ 3132 if (error == 0 && startoff == endoff) 3133 error = EINVAL; /* Any error. Reset to 0. */ 3134 } 3135 if (error == 0) { 3136 if (startoff > *inoffp) { 3137 /* Found hole before data block. */ 3138 xfer = MIN(startoff - *inoffp, len); 3139 if (*outoffp < va.va_size) { 3140 /* Must write 0s to punch hole. */ 3141 xfer2 = MIN(va.va_size - *outoffp, 3142 xfer); 3143 memset(dat, 0, MIN(xfer2, blksize)); 3144 error = vn_write_outvp(outvp, dat, 3145 *outoffp, xfer2, blksize, false, 3146 holeout > 0, outcred); 3147 } 3148 3149 if (error == 0 && *outoffp + xfer > 3150 va.va_size && xfer == len) 3151 /* Grow last block. */ 3152 error = vn_write_outvp(outvp, dat, 3153 *outoffp, xfer, blksize, true, 3154 false, outcred); 3155 if (error == 0) { 3156 *inoffp += xfer; 3157 *outoffp += xfer; 3158 len -= xfer; 3159 } 3160 } 3161 copylen = MIN(len, endoff - startoff); 3162 cantseek = false; 3163 } else { 3164 cantseek = true; 3165 startoff = *inoffp; 3166 copylen = len; 3167 error = 0; 3168 } 3169 3170 xfer = blksize; 3171 if (cantseek) { 3172 /* 3173 * Set first xfer to end at a block boundary, so that 3174 * holes are more likely detected in the loop below via 3175 * the for all bytes 0 method. 3176 */ 3177 xfer -= (*inoffp % blksize); 3178 } 3179 /* Loop copying the data block. */ 3180 while (copylen > 0 && error == 0 && !eof) { 3181 if (copylen < xfer) 3182 xfer = copylen; 3183 error = vn_lock(invp, LK_SHARED); 3184 if (error != 0) 3185 goto out; 3186 error = vn_rdwr(UIO_READ, invp, dat, xfer, 3187 startoff, UIO_SYSSPACE, IO_NODELOCKED, 3188 curthread->td_ucred, incred, &aresid, 3189 curthread); 3190 VOP_UNLOCK(invp); 3191 lastblock = false; 3192 if (error == 0 && aresid > 0) { 3193 /* Stop the copy at EOF on the input file. */ 3194 xfer -= aresid; 3195 eof = true; 3196 lastblock = true; 3197 } 3198 if (error == 0) { 3199 /* 3200 * Skip the write for holes past the initial EOF 3201 * of the output file, unless this is the last 3202 * write of the output file at EOF. 3203 */ 3204 readzeros = cantseek ? mem_iszero(dat, xfer) : 3205 false; 3206 if (xfer == len) 3207 lastblock = true; 3208 if (!cantseek || *outoffp < va.va_size || 3209 lastblock || !readzeros) 3210 error = vn_write_outvp(outvp, dat, 3211 *outoffp, xfer, blksize, 3212 readzeros && lastblock && 3213 *outoffp >= va.va_size, false, 3214 outcred); 3215 if (error == 0) { 3216 *inoffp += xfer; 3217 startoff += xfer; 3218 *outoffp += xfer; 3219 copylen -= xfer; 3220 len -= xfer; 3221 } 3222 } 3223 xfer = blksize; 3224 } 3225 } 3226 out: 3227 *lenp = savlen - len; 3228 free(dat, M_TEMP); 3229 return (error); 3230 } 3231 3232 static int 3233 vn_fallocate(struct file *fp, off_t offset, off_t len, struct thread *td) 3234 { 3235 struct mount *mp; 3236 struct vnode *vp; 3237 off_t olen, ooffset; 3238 int error; 3239 #ifdef AUDIT 3240 int audited_vnode1 = 0; 3241 #endif 3242 3243 vp = fp->f_vnode; 3244 if (vp->v_type != VREG) 3245 return (ENODEV); 3246 3247 /* Allocating blocks may take a long time, so iterate. */ 3248 for (;;) { 3249 olen = len; 3250 ooffset = offset; 3251 3252 bwillwrite(); 3253 mp = NULL; 3254 error = vn_start_write(vp, &mp, V_WAIT | PCATCH); 3255 if (error != 0) 3256 break; 3257 error = vn_lock(vp, LK_EXCLUSIVE); 3258 if (error != 0) { 3259 vn_finished_write(mp); 3260 break; 3261 } 3262 #ifdef AUDIT 3263 if (!audited_vnode1) { 3264 AUDIT_ARG_VNODE1(vp); 3265 audited_vnode1 = 1; 3266 } 3267 #endif 3268 #ifdef MAC 3269 error = mac_vnode_check_write(td->td_ucred, fp->f_cred, vp); 3270 if (error == 0) 3271 #endif 3272 error = VOP_ALLOCATE(vp, &offset, &len); 3273 VOP_UNLOCK(vp); 3274 vn_finished_write(mp); 3275 3276 if (olen + ooffset != offset + len) { 3277 panic("offset + len changed from %jx/%jx to %jx/%jx", 3278 ooffset, olen, offset, len); 3279 } 3280 if (error != 0 || len == 0) 3281 break; 3282 KASSERT(olen > len, ("Iteration did not make progress?")); 3283 maybe_yield(); 3284 } 3285 3286 return (error); 3287 } 3288