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