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