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