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