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