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/stat.h> 58 #include <sys/priv.h> 59 #include <sys/proc.h> 60 #include <sys/limits.h> 61 #include <sys/lock.h> 62 #include <sys/mman.h> 63 #include <sys/mount.h> 64 #include <sys/mutex.h> 65 #include <sys/namei.h> 66 #include <sys/vnode.h> 67 #include <sys/bio.h> 68 #include <sys/buf.h> 69 #include <sys/filio.h> 70 #include <sys/resourcevar.h> 71 #include <sys/rwlock.h> 72 #include <sys/sx.h> 73 #include <sys/sysctl.h> 74 #include <sys/ttycom.h> 75 #include <sys/conf.h> 76 #include <sys/syslog.h> 77 #include <sys/unistd.h> 78 #include <sys/user.h> 79 80 #include <security/audit/audit.h> 81 #include <security/mac/mac_framework.h> 82 83 #include <vm/vm.h> 84 #include <vm/vm_extern.h> 85 #include <vm/pmap.h> 86 #include <vm/vm_map.h> 87 #include <vm/vm_object.h> 88 #include <vm/vm_page.h> 89 #include <vm/vnode_pager.h> 90 91 #ifdef HWPMC_HOOKS 92 #include <sys/pmckern.h> 93 #endif 94 95 static fo_rdwr_t vn_read; 96 static fo_rdwr_t vn_write; 97 static fo_rdwr_t vn_io_fault; 98 static fo_truncate_t vn_truncate; 99 static fo_ioctl_t vn_ioctl; 100 static fo_poll_t vn_poll; 101 static fo_kqfilter_t vn_kqfilter; 102 static fo_stat_t vn_statfile; 103 static fo_close_t vn_closefile; 104 static fo_mmap_t vn_mmap; 105 106 struct fileops vnops = { 107 .fo_read = vn_io_fault, 108 .fo_write = vn_io_fault, 109 .fo_truncate = vn_truncate, 110 .fo_ioctl = vn_ioctl, 111 .fo_poll = vn_poll, 112 .fo_kqfilter = vn_kqfilter, 113 .fo_stat = vn_statfile, 114 .fo_close = vn_closefile, 115 .fo_chmod = vn_chmod, 116 .fo_chown = vn_chown, 117 .fo_sendfile = vn_sendfile, 118 .fo_seek = vn_seek, 119 .fo_fill_kinfo = vn_fill_kinfo, 120 .fo_mmap = vn_mmap, 121 .fo_flags = DFLAG_PASSABLE | DFLAG_SEEKABLE 122 }; 123 124 static const int io_hold_cnt = 16; 125 static int vn_io_fault_enable = 1; 126 SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_enable, CTLFLAG_RW, 127 &vn_io_fault_enable, 0, "Enable vn_io_fault lock avoidance"); 128 static int vn_io_fault_prefault = 0; 129 SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_prefault, CTLFLAG_RW, 130 &vn_io_fault_prefault, 0, "Enable vn_io_fault prefaulting"); 131 static u_long vn_io_faults_cnt; 132 SYSCTL_ULONG(_debug, OID_AUTO, vn_io_faults, CTLFLAG_RD, 133 &vn_io_faults_cnt, 0, "Count of vn_io_fault lock avoidance triggers"); 134 135 /* 136 * Returns true if vn_io_fault mode of handling the i/o request should 137 * be used. 138 */ 139 static bool 140 do_vn_io_fault(struct vnode *vp, struct uio *uio) 141 { 142 struct mount *mp; 143 144 return (uio->uio_segflg == UIO_USERSPACE && vp->v_type == VREG && 145 (mp = vp->v_mount) != NULL && 146 (mp->mnt_kern_flag & MNTK_NO_IOPF) != 0 && vn_io_fault_enable); 147 } 148 149 /* 150 * Structure used to pass arguments to vn_io_fault1(), to do either 151 * file- or vnode-based I/O calls. 152 */ 153 struct vn_io_fault_args { 154 enum { 155 VN_IO_FAULT_FOP, 156 VN_IO_FAULT_VOP 157 } kind; 158 struct ucred *cred; 159 int flags; 160 union { 161 struct fop_args_tag { 162 struct file *fp; 163 fo_rdwr_t *doio; 164 } fop_args; 165 struct vop_args_tag { 166 struct vnode *vp; 167 } vop_args; 168 } args; 169 }; 170 171 static int vn_io_fault1(struct vnode *vp, struct uio *uio, 172 struct vn_io_fault_args *args, struct thread *td); 173 174 int 175 vn_open(struct nameidata *ndp, int *flagp, int cmode, struct file *fp) 176 { 177 struct thread *td = ndp->ni_cnd.cn_thread; 178 179 return (vn_open_cred(ndp, flagp, cmode, 0, td->td_ucred, fp)); 180 } 181 182 /* 183 * Common code for vnode open operations via a name lookup. 184 * Lookup the vnode and invoke VOP_CREATE if needed. 185 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine. 186 * 187 * Note that this does NOT free nameidata for the successful case, 188 * due to the NDINIT being done elsewhere. 189 */ 190 int 191 vn_open_cred(struct nameidata *ndp, int *flagp, int cmode, u_int vn_open_flags, 192 struct ucred *cred, struct file *fp) 193 { 194 struct vnode *vp; 195 struct mount *mp; 196 struct thread *td = ndp->ni_cnd.cn_thread; 197 struct vattr vat; 198 struct vattr *vap = &vat; 199 int fmode, error; 200 201 restart: 202 fmode = *flagp; 203 if ((fmode & (O_CREAT | O_EXCL | O_DIRECTORY)) == (O_CREAT | 204 O_EXCL | O_DIRECTORY)) 205 return (EINVAL); 206 else if ((fmode & (O_CREAT | O_DIRECTORY)) == O_CREAT) { 207 ndp->ni_cnd.cn_nameiop = CREATE; 208 /* 209 * Set NOCACHE to avoid flushing the cache when 210 * rolling in many files at once. 211 */ 212 ndp->ni_cnd.cn_flags = ISOPEN | LOCKPARENT | LOCKLEAF | NOCACHE; 213 if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0) 214 ndp->ni_cnd.cn_flags |= FOLLOW; 215 if ((fmode & O_BENEATH) != 0) 216 ndp->ni_cnd.cn_flags |= BENEATH; 217 if (!(vn_open_flags & VN_OPEN_NOAUDIT)) 218 ndp->ni_cnd.cn_flags |= AUDITVNODE1; 219 if (vn_open_flags & VN_OPEN_NOCAPCHECK) 220 ndp->ni_cnd.cn_flags |= NOCAPCHECK; 221 bwillwrite(); 222 if ((error = namei(ndp)) != 0) 223 return (error); 224 if (ndp->ni_vp == NULL) { 225 VATTR_NULL(vap); 226 vap->va_type = VREG; 227 vap->va_mode = cmode; 228 if (fmode & O_EXCL) 229 vap->va_vaflags |= VA_EXCLUSIVE; 230 if (vn_start_write(ndp->ni_dvp, &mp, V_NOWAIT) != 0) { 231 NDFREE(ndp, NDF_ONLY_PNBUF); 232 vput(ndp->ni_dvp); 233 if ((error = vn_start_write(NULL, &mp, 234 V_XSLEEP | PCATCH)) != 0) 235 return (error); 236 goto restart; 237 } 238 if ((vn_open_flags & VN_OPEN_NAMECACHE) != 0) 239 ndp->ni_cnd.cn_flags |= MAKEENTRY; 240 #ifdef MAC 241 error = mac_vnode_check_create(cred, ndp->ni_dvp, 242 &ndp->ni_cnd, vap); 243 if (error == 0) 244 #endif 245 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp, 246 &ndp->ni_cnd, vap); 247 vput(ndp->ni_dvp); 248 vn_finished_write(mp); 249 if (error) { 250 NDFREE(ndp, NDF_ONLY_PNBUF); 251 return (error); 252 } 253 fmode &= ~O_TRUNC; 254 vp = ndp->ni_vp; 255 } else { 256 if (ndp->ni_dvp == ndp->ni_vp) 257 vrele(ndp->ni_dvp); 258 else 259 vput(ndp->ni_dvp); 260 ndp->ni_dvp = NULL; 261 vp = ndp->ni_vp; 262 if (fmode & O_EXCL) { 263 error = EEXIST; 264 goto bad; 265 } 266 fmode &= ~O_CREAT; 267 } 268 } else { 269 ndp->ni_cnd.cn_nameiop = LOOKUP; 270 ndp->ni_cnd.cn_flags = ISOPEN | 271 ((fmode & O_NOFOLLOW) ? NOFOLLOW : FOLLOW) | LOCKLEAF; 272 if (!(fmode & FWRITE)) 273 ndp->ni_cnd.cn_flags |= LOCKSHARED; 274 if ((fmode & O_BENEATH) != 0) 275 ndp->ni_cnd.cn_flags |= BENEATH; 276 if (!(vn_open_flags & VN_OPEN_NOAUDIT)) 277 ndp->ni_cnd.cn_flags |= AUDITVNODE1; 278 if (vn_open_flags & VN_OPEN_NOCAPCHECK) 279 ndp->ni_cnd.cn_flags |= NOCAPCHECK; 280 if ((error = namei(ndp)) != 0) 281 return (error); 282 vp = ndp->ni_vp; 283 } 284 error = vn_open_vnode(vp, fmode, cred, td, fp); 285 if (error) 286 goto bad; 287 *flagp = fmode; 288 return (0); 289 bad: 290 NDFREE(ndp, NDF_ONLY_PNBUF); 291 vput(vp); 292 *flagp = fmode; 293 ndp->ni_vp = NULL; 294 return (error); 295 } 296 297 /* 298 * Common code for vnode open operations once a vnode is located. 299 * Check permissions, and call the VOP_OPEN routine. 300 */ 301 int 302 vn_open_vnode(struct vnode *vp, int fmode, struct ucred *cred, 303 struct thread *td, struct file *fp) 304 { 305 accmode_t accmode; 306 struct flock lf; 307 int error, lock_flags, type; 308 309 if (vp->v_type == VLNK) 310 return (EMLINK); 311 if (vp->v_type == VSOCK) 312 return (EOPNOTSUPP); 313 if (vp->v_type != VDIR && fmode & O_DIRECTORY) 314 return (ENOTDIR); 315 accmode = 0; 316 if (fmode & (FWRITE | O_TRUNC)) { 317 if (vp->v_type == VDIR) 318 return (EISDIR); 319 accmode |= VWRITE; 320 } 321 if (fmode & FREAD) 322 accmode |= VREAD; 323 if (fmode & FEXEC) 324 accmode |= VEXEC; 325 if ((fmode & O_APPEND) && (fmode & FWRITE)) 326 accmode |= VAPPEND; 327 #ifdef MAC 328 if (fmode & O_CREAT) 329 accmode |= VCREAT; 330 if (fmode & O_VERIFY) 331 accmode |= VVERIFY; 332 error = mac_vnode_check_open(cred, vp, accmode); 333 if (error) 334 return (error); 335 336 accmode &= ~(VCREAT | VVERIFY); 337 #endif 338 if ((fmode & O_CREAT) == 0) { 339 if (accmode & VWRITE) { 340 error = vn_writechk(vp); 341 if (error) 342 return (error); 343 } 344 if (accmode) { 345 error = VOP_ACCESS(vp, accmode, cred, td); 346 if (error) 347 return (error); 348 } 349 } 350 if (vp->v_type == VFIFO && VOP_ISLOCKED(vp) != LK_EXCLUSIVE) 351 vn_lock(vp, LK_UPGRADE | LK_RETRY); 352 if ((error = VOP_OPEN(vp, fmode, cred, td, fp)) != 0) 353 return (error); 354 355 while ((fmode & (O_EXLOCK | O_SHLOCK)) != 0) { 356 KASSERT(fp != NULL, ("open with flock requires fp")); 357 if (fp->f_type != DTYPE_NONE && fp->f_type != DTYPE_VNODE) { 358 error = EOPNOTSUPP; 359 break; 360 } 361 lock_flags = VOP_ISLOCKED(vp); 362 VOP_UNLOCK(vp, 0); 363 lf.l_whence = SEEK_SET; 364 lf.l_start = 0; 365 lf.l_len = 0; 366 if (fmode & O_EXLOCK) 367 lf.l_type = F_WRLCK; 368 else 369 lf.l_type = F_RDLCK; 370 type = F_FLOCK; 371 if ((fmode & FNONBLOCK) == 0) 372 type |= F_WAIT; 373 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, type); 374 if (error == 0) 375 fp->f_flag |= FHASLOCK; 376 vn_lock(vp, lock_flags | LK_RETRY); 377 if (error != 0) 378 break; 379 if ((vp->v_iflag & VI_DOOMED) != 0) { 380 error = ENOENT; 381 break; 382 } 383 384 /* 385 * Another thread might have used this vnode as an 386 * executable while the vnode lock was dropped. 387 * Ensure the vnode is still able to be opened for 388 * writing after the lock has been obtained. 389 */ 390 if ((accmode & VWRITE) != 0) 391 error = vn_writechk(vp); 392 break; 393 } 394 395 if (error != 0) { 396 fp->f_flag |= FOPENFAILED; 397 fp->f_vnode = vp; 398 if (fp->f_ops == &badfileops) { 399 fp->f_type = DTYPE_VNODE; 400 fp->f_ops = &vnops; 401 } 402 vref(vp); 403 } else if ((fmode & FWRITE) != 0) { 404 VOP_ADD_WRITECOUNT(vp, 1); 405 CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d", 406 __func__, vp, vp->v_writecount); 407 } 408 ASSERT_VOP_LOCKED(vp, "vn_open_vnode"); 409 return (error); 410 } 411 412 /* 413 * Check for write permissions on the specified vnode. 414 * Prototype text segments cannot be written. 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 VNASSERT(vp->v_writecount > 0, vp, 453 ("vn_close: negative writecount")); 454 VOP_ADD_WRITECOUNT(vp, -1); 455 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d", 456 __func__, vp, vp->v_writecount); 457 } 458 error = VOP_CLOSE(vp, flags, file_cred, td); 459 if (keep_ref) 460 VOP_UNLOCK(vp, 0); 461 else 462 vput(vp); 463 vn_finished_write(mp); 464 return (error); 465 } 466 467 int 468 vn_close(struct vnode *vp, int flags, struct ucred *file_cred, 469 struct thread *td) 470 { 471 472 return (vn_close1(vp, flags, file_cred, td, false)); 473 } 474 475 /* 476 * Heuristic to detect sequential operation. 477 */ 478 static int 479 sequential_heuristic(struct uio *uio, struct file *fp) 480 { 481 482 ASSERT_VOP_LOCKED(fp->f_vnode, __func__); 483 if (fp->f_flag & FRDAHEAD) 484 return (fp->f_seqcount << IO_SEQSHIFT); 485 486 /* 487 * Offset 0 is handled specially. open() sets f_seqcount to 1 so 488 * that the first I/O is normally considered to be slightly 489 * sequential. Seeking to offset 0 doesn't change sequentiality 490 * unless previous seeks have reduced f_seqcount to 0, in which 491 * case offset 0 is not special. 492 */ 493 if ((uio->uio_offset == 0 && fp->f_seqcount > 0) || 494 uio->uio_offset == fp->f_nextoff) { 495 /* 496 * f_seqcount is in units of fixed-size blocks so that it 497 * depends mainly on the amount of sequential I/O and not 498 * much on the number of sequential I/O's. The fixed size 499 * of 16384 is hard-coded here since it is (not quite) just 500 * a magic size that works well here. This size is more 501 * closely related to the best I/O size for real disks than 502 * to any block size used by software. 503 */ 504 fp->f_seqcount += howmany(uio->uio_resid, 16384); 505 if (fp->f_seqcount > IO_SEQMAX) 506 fp->f_seqcount = IO_SEQMAX; 507 return (fp->f_seqcount << IO_SEQSHIFT); 508 } 509 510 /* Not sequential. Quickly draw-down sequentiality. */ 511 if (fp->f_seqcount > 1) 512 fp->f_seqcount = 1; 513 else 514 fp->f_seqcount = 0; 515 return (0); 516 } 517 518 /* 519 * Package up an I/O request on a vnode into a uio and do it. 520 */ 521 int 522 vn_rdwr(enum uio_rw rw, struct vnode *vp, void *base, int len, off_t offset, 523 enum uio_seg segflg, int ioflg, struct ucred *active_cred, 524 struct ucred *file_cred, ssize_t *aresid, struct thread *td) 525 { 526 struct uio auio; 527 struct iovec aiov; 528 struct mount *mp; 529 struct ucred *cred; 530 void *rl_cookie; 531 struct vn_io_fault_args args; 532 int error, lock_flags; 533 534 if (offset < 0 && vp->v_type != VCHR) 535 return (EINVAL); 536 auio.uio_iov = &aiov; 537 auio.uio_iovcnt = 1; 538 aiov.iov_base = base; 539 aiov.iov_len = len; 540 auio.uio_resid = len; 541 auio.uio_offset = offset; 542 auio.uio_segflg = segflg; 543 auio.uio_rw = rw; 544 auio.uio_td = td; 545 error = 0; 546 547 if ((ioflg & IO_NODELOCKED) == 0) { 548 if ((ioflg & IO_RANGELOCKED) == 0) { 549 if (rw == UIO_READ) { 550 rl_cookie = vn_rangelock_rlock(vp, offset, 551 offset + len); 552 } else { 553 rl_cookie = vn_rangelock_wlock(vp, offset, 554 offset + len); 555 } 556 } else 557 rl_cookie = NULL; 558 mp = NULL; 559 if (rw == UIO_WRITE) { 560 if (vp->v_type != VCHR && 561 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) 562 != 0) 563 goto out; 564 if (MNT_SHARED_WRITES(mp) || 565 ((mp == NULL) && MNT_SHARED_WRITES(vp->v_mount))) 566 lock_flags = LK_SHARED; 567 else 568 lock_flags = LK_EXCLUSIVE; 569 } else 570 lock_flags = LK_SHARED; 571 vn_lock(vp, lock_flags | LK_RETRY); 572 } else 573 rl_cookie = NULL; 574 575 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 576 #ifdef MAC 577 if ((ioflg & IO_NOMACCHECK) == 0) { 578 if (rw == UIO_READ) 579 error = mac_vnode_check_read(active_cred, file_cred, 580 vp); 581 else 582 error = mac_vnode_check_write(active_cred, file_cred, 583 vp); 584 } 585 #endif 586 if (error == 0) { 587 if (file_cred != NULL) 588 cred = file_cred; 589 else 590 cred = active_cred; 591 if (do_vn_io_fault(vp, &auio)) { 592 args.kind = VN_IO_FAULT_VOP; 593 args.cred = cred; 594 args.flags = ioflg; 595 args.args.vop_args.vp = vp; 596 error = vn_io_fault1(vp, &auio, &args, td); 597 } else if (rw == UIO_READ) { 598 error = VOP_READ(vp, &auio, ioflg, cred); 599 } else /* if (rw == UIO_WRITE) */ { 600 error = VOP_WRITE(vp, &auio, ioflg, cred); 601 } 602 } 603 if (aresid) 604 *aresid = auio.uio_resid; 605 else 606 if (auio.uio_resid && error == 0) 607 error = EIO; 608 if ((ioflg & IO_NODELOCKED) == 0) { 609 VOP_UNLOCK(vp, 0); 610 if (mp != NULL) 611 vn_finished_write(mp); 612 } 613 out: 614 if (rl_cookie != NULL) 615 vn_rangelock_unlock(vp, rl_cookie); 616 return (error); 617 } 618 619 /* 620 * Package up an I/O request on a vnode into a uio and do it. The I/O 621 * request is split up into smaller chunks and we try to avoid saturating 622 * the buffer cache while potentially holding a vnode locked, so we 623 * check bwillwrite() before calling vn_rdwr(). We also call kern_yield() 624 * to give other processes a chance to lock the vnode (either other processes 625 * core'ing the same binary, or unrelated processes scanning the directory). 626 */ 627 int 628 vn_rdwr_inchunks(enum uio_rw rw, struct vnode *vp, void *base, size_t len, 629 off_t offset, enum uio_seg segflg, int ioflg, struct ucred *active_cred, 630 struct ucred *file_cred, size_t *aresid, struct thread *td) 631 { 632 int error = 0; 633 ssize_t iaresid; 634 635 do { 636 int chunk; 637 638 /* 639 * Force `offset' to a multiple of MAXBSIZE except possibly 640 * for the first chunk, so that filesystems only need to 641 * write full blocks except possibly for the first and last 642 * chunks. 643 */ 644 chunk = MAXBSIZE - (uoff_t)offset % MAXBSIZE; 645 646 if (chunk > len) 647 chunk = len; 648 if (rw != UIO_READ && vp->v_type == VREG) 649 bwillwrite(); 650 iaresid = 0; 651 error = vn_rdwr(rw, vp, base, chunk, offset, segflg, 652 ioflg, active_cred, file_cred, &iaresid, td); 653 len -= chunk; /* aresid calc already includes length */ 654 if (error) 655 break; 656 offset += chunk; 657 base = (char *)base + chunk; 658 kern_yield(PRI_USER); 659 } while (len); 660 if (aresid) 661 *aresid = len + iaresid; 662 return (error); 663 } 664 665 off_t 666 foffset_lock(struct file *fp, int flags) 667 { 668 struct mtx *mtxp; 669 off_t res; 670 671 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed")); 672 673 #if OFF_MAX <= LONG_MAX 674 /* 675 * Caller only wants the current f_offset value. Assume that 676 * the long and shorter integer types reads are atomic. 677 */ 678 if ((flags & FOF_NOLOCK) != 0) 679 return (fp->f_offset); 680 #endif 681 682 /* 683 * According to McKusick the vn lock was protecting f_offset here. 684 * It is now protected by the FOFFSET_LOCKED flag. 685 */ 686 mtxp = mtx_pool_find(mtxpool_sleep, fp); 687 mtx_lock(mtxp); 688 if ((flags & FOF_NOLOCK) == 0) { 689 while (fp->f_vnread_flags & FOFFSET_LOCKED) { 690 fp->f_vnread_flags |= FOFFSET_LOCK_WAITING; 691 msleep(&fp->f_vnread_flags, mtxp, PUSER -1, 692 "vofflock", 0); 693 } 694 fp->f_vnread_flags |= FOFFSET_LOCKED; 695 } 696 res = fp->f_offset; 697 mtx_unlock(mtxp); 698 return (res); 699 } 700 701 void 702 foffset_unlock(struct file *fp, off_t val, int flags) 703 { 704 struct mtx *mtxp; 705 706 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed")); 707 708 #if OFF_MAX <= LONG_MAX 709 if ((flags & FOF_NOLOCK) != 0) { 710 if ((flags & FOF_NOUPDATE) == 0) 711 fp->f_offset = val; 712 if ((flags & FOF_NEXTOFF) != 0) 713 fp->f_nextoff = val; 714 return; 715 } 716 #endif 717 718 mtxp = mtx_pool_find(mtxpool_sleep, fp); 719 mtx_lock(mtxp); 720 if ((flags & FOF_NOUPDATE) == 0) 721 fp->f_offset = val; 722 if ((flags & FOF_NEXTOFF) != 0) 723 fp->f_nextoff = val; 724 if ((flags & FOF_NOLOCK) == 0) { 725 KASSERT((fp->f_vnread_flags & FOFFSET_LOCKED) != 0, 726 ("Lost FOFFSET_LOCKED")); 727 if (fp->f_vnread_flags & FOFFSET_LOCK_WAITING) 728 wakeup(&fp->f_vnread_flags); 729 fp->f_vnread_flags = 0; 730 } 731 mtx_unlock(mtxp); 732 } 733 734 void 735 foffset_lock_uio(struct file *fp, struct uio *uio, int flags) 736 { 737 738 if ((flags & FOF_OFFSET) == 0) 739 uio->uio_offset = foffset_lock(fp, flags); 740 } 741 742 void 743 foffset_unlock_uio(struct file *fp, struct uio *uio, int flags) 744 { 745 746 if ((flags & FOF_OFFSET) == 0) 747 foffset_unlock(fp, uio->uio_offset, flags); 748 } 749 750 static int 751 get_advice(struct file *fp, struct uio *uio) 752 { 753 struct mtx *mtxp; 754 int ret; 755 756 ret = POSIX_FADV_NORMAL; 757 if (fp->f_advice == NULL || fp->f_vnode->v_type != VREG) 758 return (ret); 759 760 mtxp = mtx_pool_find(mtxpool_sleep, fp); 761 mtx_lock(mtxp); 762 if (fp->f_advice != NULL && 763 uio->uio_offset >= fp->f_advice->fa_start && 764 uio->uio_offset + uio->uio_resid <= fp->f_advice->fa_end) 765 ret = fp->f_advice->fa_advice; 766 mtx_unlock(mtxp); 767 return (ret); 768 } 769 770 /* 771 * File table vnode read routine. 772 */ 773 static int 774 vn_read(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags, 775 struct thread *td) 776 { 777 struct vnode *vp; 778 off_t orig_offset; 779 int error, ioflag; 780 int advice; 781 782 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", 783 uio->uio_td, td)); 784 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET")); 785 vp = fp->f_vnode; 786 ioflag = 0; 787 if (fp->f_flag & FNONBLOCK) 788 ioflag |= IO_NDELAY; 789 if (fp->f_flag & O_DIRECT) 790 ioflag |= IO_DIRECT; 791 advice = get_advice(fp, uio); 792 vn_lock(vp, LK_SHARED | LK_RETRY); 793 794 switch (advice) { 795 case POSIX_FADV_NORMAL: 796 case POSIX_FADV_SEQUENTIAL: 797 case POSIX_FADV_NOREUSE: 798 ioflag |= sequential_heuristic(uio, fp); 799 break; 800 case POSIX_FADV_RANDOM: 801 /* Disable read-ahead for random I/O. */ 802 break; 803 } 804 orig_offset = uio->uio_offset; 805 806 #ifdef MAC 807 error = mac_vnode_check_read(active_cred, fp->f_cred, vp); 808 if (error == 0) 809 #endif 810 error = VOP_READ(vp, uio, ioflag, fp->f_cred); 811 fp->f_nextoff = uio->uio_offset; 812 VOP_UNLOCK(vp, 0); 813 if (error == 0 && advice == POSIX_FADV_NOREUSE && 814 orig_offset != uio->uio_offset) 815 /* 816 * Use POSIX_FADV_DONTNEED to flush pages and buffers 817 * for the backing file after a POSIX_FADV_NOREUSE 818 * read(2). 819 */ 820 error = VOP_ADVISE(vp, orig_offset, uio->uio_offset - 1, 821 POSIX_FADV_DONTNEED); 822 return (error); 823 } 824 825 /* 826 * File table vnode write routine. 827 */ 828 static int 829 vn_write(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags, 830 struct thread *td) 831 { 832 struct vnode *vp; 833 struct mount *mp; 834 off_t orig_offset; 835 int error, ioflag, lock_flags; 836 int advice; 837 838 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", 839 uio->uio_td, td)); 840 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET")); 841 vp = fp->f_vnode; 842 if (vp->v_type == VREG) 843 bwillwrite(); 844 ioflag = IO_UNIT; 845 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 846 ioflag |= IO_APPEND; 847 if (fp->f_flag & FNONBLOCK) 848 ioflag |= IO_NDELAY; 849 if (fp->f_flag & O_DIRECT) 850 ioflag |= IO_DIRECT; 851 if ((fp->f_flag & O_FSYNC) || 852 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS))) 853 ioflag |= IO_SYNC; 854 mp = NULL; 855 if (vp->v_type != VCHR && 856 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0) 857 goto unlock; 858 859 advice = get_advice(fp, uio); 860 861 if (MNT_SHARED_WRITES(mp) || 862 (mp == NULL && MNT_SHARED_WRITES(vp->v_mount))) { 863 lock_flags = LK_SHARED; 864 } else { 865 lock_flags = LK_EXCLUSIVE; 866 } 867 868 vn_lock(vp, lock_flags | LK_RETRY); 869 switch (advice) { 870 case POSIX_FADV_NORMAL: 871 case POSIX_FADV_SEQUENTIAL: 872 case POSIX_FADV_NOREUSE: 873 ioflag |= sequential_heuristic(uio, fp); 874 break; 875 case POSIX_FADV_RANDOM: 876 /* XXX: Is this correct? */ 877 break; 878 } 879 orig_offset = uio->uio_offset; 880 881 #ifdef MAC 882 error = mac_vnode_check_write(active_cred, fp->f_cred, vp); 883 if (error == 0) 884 #endif 885 error = VOP_WRITE(vp, uio, ioflag, fp->f_cred); 886 fp->f_nextoff = uio->uio_offset; 887 VOP_UNLOCK(vp, 0); 888 if (vp->v_type != VCHR) 889 vn_finished_write(mp); 890 if (error == 0 && advice == POSIX_FADV_NOREUSE && 891 orig_offset != uio->uio_offset) 892 /* 893 * Use POSIX_FADV_DONTNEED to flush pages and buffers 894 * for the backing file after a POSIX_FADV_NOREUSE 895 * write(2). 896 */ 897 error = VOP_ADVISE(vp, orig_offset, uio->uio_offset - 1, 898 POSIX_FADV_DONTNEED); 899 unlock: 900 return (error); 901 } 902 903 /* 904 * The vn_io_fault() is a wrapper around vn_read() and vn_write() to 905 * prevent the following deadlock: 906 * 907 * Assume that the thread A reads from the vnode vp1 into userspace 908 * buffer buf1 backed by the pages of vnode vp2. If a page in buf1 is 909 * currently not resident, then system ends up with the call chain 910 * vn_read() -> VOP_READ(vp1) -> uiomove() -> [Page Fault] -> 911 * vm_fault(buf1) -> vnode_pager_getpages(vp2) -> VOP_GETPAGES(vp2) 912 * which establishes lock order vp1->vn_lock, then vp2->vn_lock. 913 * If, at the same time, thread B reads from vnode vp2 into buffer buf2 914 * backed by the pages of vnode vp1, and some page in buf2 is not 915 * resident, we get a reversed order vp2->vn_lock, then vp1->vn_lock. 916 * 917 * To prevent the lock order reversal and deadlock, vn_io_fault() does 918 * not allow page faults to happen during VOP_READ() or VOP_WRITE(). 919 * Instead, it first tries to do the whole range i/o with pagefaults 920 * disabled. If all pages in the i/o buffer are resident and mapped, 921 * VOP will succeed (ignoring the genuine filesystem errors). 922 * Otherwise, we get back EFAULT, and vn_io_fault() falls back to do 923 * i/o in chunks, with all pages in the chunk prefaulted and held 924 * using vm_fault_quick_hold_pages(). 925 * 926 * Filesystems using this deadlock avoidance scheme should use the 927 * array of the held pages from uio, saved in the curthread->td_ma, 928 * instead of doing uiomove(). A helper function 929 * vn_io_fault_uiomove() converts uiomove request into 930 * uiomove_fromphys() over td_ma array. 931 * 932 * Since vnode locks do not cover the whole i/o anymore, rangelocks 933 * make the current i/o request atomic with respect to other i/os and 934 * truncations. 935 */ 936 937 /* 938 * Decode vn_io_fault_args and perform the corresponding i/o. 939 */ 940 static int 941 vn_io_fault_doio(struct vn_io_fault_args *args, struct uio *uio, 942 struct thread *td) 943 { 944 int error, save; 945 946 error = 0; 947 save = vm_fault_disable_pagefaults(); 948 switch (args->kind) { 949 case VN_IO_FAULT_FOP: 950 error = (args->args.fop_args.doio)(args->args.fop_args.fp, 951 uio, args->cred, args->flags, td); 952 break; 953 case VN_IO_FAULT_VOP: 954 if (uio->uio_rw == UIO_READ) { 955 error = VOP_READ(args->args.vop_args.vp, uio, 956 args->flags, args->cred); 957 } else if (uio->uio_rw == UIO_WRITE) { 958 error = VOP_WRITE(args->args.vop_args.vp, uio, 959 args->flags, args->cred); 960 } 961 break; 962 default: 963 panic("vn_io_fault_doio: unknown kind of io %d %d", 964 args->kind, uio->uio_rw); 965 } 966 vm_fault_enable_pagefaults(save); 967 return (error); 968 } 969 970 static int 971 vn_io_fault_touch(char *base, const struct uio *uio) 972 { 973 int r; 974 975 r = fubyte(base); 976 if (r == -1 || (uio->uio_rw == UIO_READ && subyte(base, r) == -1)) 977 return (EFAULT); 978 return (0); 979 } 980 981 static int 982 vn_io_fault_prefault_user(const struct uio *uio) 983 { 984 char *base; 985 const struct iovec *iov; 986 size_t len; 987 ssize_t resid; 988 int error, i; 989 990 KASSERT(uio->uio_segflg == UIO_USERSPACE, 991 ("vn_io_fault_prefault userspace")); 992 993 error = i = 0; 994 iov = uio->uio_iov; 995 resid = uio->uio_resid; 996 base = iov->iov_base; 997 len = iov->iov_len; 998 while (resid > 0) { 999 error = vn_io_fault_touch(base, uio); 1000 if (error != 0) 1001 break; 1002 if (len < PAGE_SIZE) { 1003 if (len != 0) { 1004 error = vn_io_fault_touch(base + len - 1, uio); 1005 if (error != 0) 1006 break; 1007 resid -= len; 1008 } 1009 if (++i >= uio->uio_iovcnt) 1010 break; 1011 iov = uio->uio_iov + i; 1012 base = iov->iov_base; 1013 len = iov->iov_len; 1014 } else { 1015 len -= PAGE_SIZE; 1016 base += PAGE_SIZE; 1017 resid -= PAGE_SIZE; 1018 } 1019 } 1020 return (error); 1021 } 1022 1023 /* 1024 * Common code for vn_io_fault(), agnostic to the kind of i/o request. 1025 * Uses vn_io_fault_doio() to make the call to an actual i/o function. 1026 * Used from vn_rdwr() and vn_io_fault(), which encode the i/o request 1027 * into args and call vn_io_fault1() to handle faults during the user 1028 * mode buffer accesses. 1029 */ 1030 static int 1031 vn_io_fault1(struct vnode *vp, struct uio *uio, struct vn_io_fault_args *args, 1032 struct thread *td) 1033 { 1034 vm_page_t ma[io_hold_cnt + 2]; 1035 struct uio *uio_clone, short_uio; 1036 struct iovec short_iovec[1]; 1037 vm_page_t *prev_td_ma; 1038 vm_prot_t prot; 1039 vm_offset_t addr, end; 1040 size_t len, resid; 1041 ssize_t adv; 1042 int error, cnt, saveheld, prev_td_ma_cnt; 1043 1044 if (vn_io_fault_prefault) { 1045 error = vn_io_fault_prefault_user(uio); 1046 if (error != 0) 1047 return (error); /* Or ignore ? */ 1048 } 1049 1050 prot = uio->uio_rw == UIO_READ ? VM_PROT_WRITE : VM_PROT_READ; 1051 1052 /* 1053 * The UFS follows IO_UNIT directive and replays back both 1054 * uio_offset and uio_resid if an error is encountered during the 1055 * operation. But, since the iovec may be already advanced, 1056 * uio is still in an inconsistent state. 1057 * 1058 * Cache a copy of the original uio, which is advanced to the redo 1059 * point using UIO_NOCOPY below. 1060 */ 1061 uio_clone = cloneuio(uio); 1062 resid = uio->uio_resid; 1063 1064 short_uio.uio_segflg = UIO_USERSPACE; 1065 short_uio.uio_rw = uio->uio_rw; 1066 short_uio.uio_td = uio->uio_td; 1067 1068 error = vn_io_fault_doio(args, uio, td); 1069 if (error != EFAULT) 1070 goto out; 1071 1072 atomic_add_long(&vn_io_faults_cnt, 1); 1073 uio_clone->uio_segflg = UIO_NOCOPY; 1074 uiomove(NULL, resid - uio->uio_resid, uio_clone); 1075 uio_clone->uio_segflg = uio->uio_segflg; 1076 1077 saveheld = curthread_pflags_set(TDP_UIOHELD); 1078 prev_td_ma = td->td_ma; 1079 prev_td_ma_cnt = td->td_ma_cnt; 1080 1081 while (uio_clone->uio_resid != 0) { 1082 len = uio_clone->uio_iov->iov_len; 1083 if (len == 0) { 1084 KASSERT(uio_clone->uio_iovcnt >= 1, 1085 ("iovcnt underflow")); 1086 uio_clone->uio_iov++; 1087 uio_clone->uio_iovcnt--; 1088 continue; 1089 } 1090 if (len > io_hold_cnt * PAGE_SIZE) 1091 len = io_hold_cnt * PAGE_SIZE; 1092 addr = (uintptr_t)uio_clone->uio_iov->iov_base; 1093 end = round_page(addr + len); 1094 if (end < addr) { 1095 error = EFAULT; 1096 break; 1097 } 1098 cnt = atop(end - trunc_page(addr)); 1099 /* 1100 * A perfectly misaligned address and length could cause 1101 * both the start and the end of the chunk to use partial 1102 * page. +2 accounts for such a situation. 1103 */ 1104 cnt = vm_fault_quick_hold_pages(&td->td_proc->p_vmspace->vm_map, 1105 addr, len, prot, ma, io_hold_cnt + 2); 1106 if (cnt == -1) { 1107 error = EFAULT; 1108 break; 1109 } 1110 short_uio.uio_iov = &short_iovec[0]; 1111 short_iovec[0].iov_base = (void *)addr; 1112 short_uio.uio_iovcnt = 1; 1113 short_uio.uio_resid = short_iovec[0].iov_len = len; 1114 short_uio.uio_offset = uio_clone->uio_offset; 1115 td->td_ma = ma; 1116 td->td_ma_cnt = cnt; 1117 1118 error = vn_io_fault_doio(args, &short_uio, td); 1119 vm_page_unhold_pages(ma, cnt); 1120 adv = len - short_uio.uio_resid; 1121 1122 uio_clone->uio_iov->iov_base = 1123 (char *)uio_clone->uio_iov->iov_base + adv; 1124 uio_clone->uio_iov->iov_len -= adv; 1125 uio_clone->uio_resid -= adv; 1126 uio_clone->uio_offset += adv; 1127 1128 uio->uio_resid -= adv; 1129 uio->uio_offset += adv; 1130 1131 if (error != 0 || adv == 0) 1132 break; 1133 } 1134 td->td_ma = prev_td_ma; 1135 td->td_ma_cnt = prev_td_ma_cnt; 1136 curthread_pflags_restore(saveheld); 1137 out: 1138 free(uio_clone, M_IOV); 1139 return (error); 1140 } 1141 1142 static int 1143 vn_io_fault(struct file *fp, struct uio *uio, struct ucred *active_cred, 1144 int flags, struct thread *td) 1145 { 1146 fo_rdwr_t *doio; 1147 struct vnode *vp; 1148 void *rl_cookie; 1149 struct vn_io_fault_args args; 1150 int error; 1151 1152 doio = uio->uio_rw == UIO_READ ? vn_read : vn_write; 1153 vp = fp->f_vnode; 1154 foffset_lock_uio(fp, uio, flags); 1155 if (do_vn_io_fault(vp, uio)) { 1156 args.kind = VN_IO_FAULT_FOP; 1157 args.args.fop_args.fp = fp; 1158 args.args.fop_args.doio = doio; 1159 args.cred = active_cred; 1160 args.flags = flags | FOF_OFFSET; 1161 if (uio->uio_rw == UIO_READ) { 1162 rl_cookie = vn_rangelock_rlock(vp, uio->uio_offset, 1163 uio->uio_offset + uio->uio_resid); 1164 } else if ((fp->f_flag & O_APPEND) != 0 || 1165 (flags & FOF_OFFSET) == 0) { 1166 /* For appenders, punt and lock the whole range. */ 1167 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 1168 } else { 1169 rl_cookie = vn_rangelock_wlock(vp, uio->uio_offset, 1170 uio->uio_offset + uio->uio_resid); 1171 } 1172 error = vn_io_fault1(vp, uio, &args, td); 1173 vn_rangelock_unlock(vp, rl_cookie); 1174 } else { 1175 error = doio(fp, uio, active_cred, flags | FOF_OFFSET, td); 1176 } 1177 foffset_unlock_uio(fp, uio, flags); 1178 return (error); 1179 } 1180 1181 /* 1182 * Helper function to perform the requested uiomove operation using 1183 * the held pages for io->uio_iov[0].iov_base buffer instead of 1184 * copyin/copyout. Access to the pages with uiomove_fromphys() 1185 * instead of iov_base prevents page faults that could occur due to 1186 * pmap_collect() invalidating the mapping created by 1187 * vm_fault_quick_hold_pages(), or pageout daemon, page laundry or 1188 * object cleanup revoking the write access from page mappings. 1189 * 1190 * Filesystems specified MNTK_NO_IOPF shall use vn_io_fault_uiomove() 1191 * instead of plain uiomove(). 1192 */ 1193 int 1194 vn_io_fault_uiomove(char *data, int xfersize, struct uio *uio) 1195 { 1196 struct uio transp_uio; 1197 struct iovec transp_iov[1]; 1198 struct thread *td; 1199 size_t adv; 1200 int error, pgadv; 1201 1202 td = curthread; 1203 if ((td->td_pflags & TDP_UIOHELD) == 0 || 1204 uio->uio_segflg != UIO_USERSPACE) 1205 return (uiomove(data, xfersize, uio)); 1206 1207 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt)); 1208 transp_iov[0].iov_base = data; 1209 transp_uio.uio_iov = &transp_iov[0]; 1210 transp_uio.uio_iovcnt = 1; 1211 if (xfersize > uio->uio_resid) 1212 xfersize = uio->uio_resid; 1213 transp_uio.uio_resid = transp_iov[0].iov_len = xfersize; 1214 transp_uio.uio_offset = 0; 1215 transp_uio.uio_segflg = UIO_SYSSPACE; 1216 /* 1217 * Since transp_iov points to data, and td_ma page array 1218 * corresponds to original uio->uio_iov, we need to invert the 1219 * direction of the i/o operation as passed to 1220 * uiomove_fromphys(). 1221 */ 1222 switch (uio->uio_rw) { 1223 case UIO_WRITE: 1224 transp_uio.uio_rw = UIO_READ; 1225 break; 1226 case UIO_READ: 1227 transp_uio.uio_rw = UIO_WRITE; 1228 break; 1229 } 1230 transp_uio.uio_td = uio->uio_td; 1231 error = uiomove_fromphys(td->td_ma, 1232 ((vm_offset_t)uio->uio_iov->iov_base) & PAGE_MASK, 1233 xfersize, &transp_uio); 1234 adv = xfersize - transp_uio.uio_resid; 1235 pgadv = 1236 (((vm_offset_t)uio->uio_iov->iov_base + adv) >> PAGE_SHIFT) - 1237 (((vm_offset_t)uio->uio_iov->iov_base) >> PAGE_SHIFT); 1238 td->td_ma += pgadv; 1239 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt, 1240 pgadv)); 1241 td->td_ma_cnt -= pgadv; 1242 uio->uio_iov->iov_base = (char *)uio->uio_iov->iov_base + adv; 1243 uio->uio_iov->iov_len -= adv; 1244 uio->uio_resid -= adv; 1245 uio->uio_offset += adv; 1246 return (error); 1247 } 1248 1249 int 1250 vn_io_fault_pgmove(vm_page_t ma[], vm_offset_t offset, int xfersize, 1251 struct uio *uio) 1252 { 1253 struct thread *td; 1254 vm_offset_t iov_base; 1255 int cnt, pgadv; 1256 1257 td = curthread; 1258 if ((td->td_pflags & TDP_UIOHELD) == 0 || 1259 uio->uio_segflg != UIO_USERSPACE) 1260 return (uiomove_fromphys(ma, offset, xfersize, uio)); 1261 1262 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt)); 1263 cnt = xfersize > uio->uio_resid ? uio->uio_resid : xfersize; 1264 iov_base = (vm_offset_t)uio->uio_iov->iov_base; 1265 switch (uio->uio_rw) { 1266 case UIO_WRITE: 1267 pmap_copy_pages(td->td_ma, iov_base & PAGE_MASK, ma, 1268 offset, cnt); 1269 break; 1270 case UIO_READ: 1271 pmap_copy_pages(ma, offset, td->td_ma, iov_base & PAGE_MASK, 1272 cnt); 1273 break; 1274 } 1275 pgadv = ((iov_base + cnt) >> PAGE_SHIFT) - (iov_base >> PAGE_SHIFT); 1276 td->td_ma += pgadv; 1277 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt, 1278 pgadv)); 1279 td->td_ma_cnt -= pgadv; 1280 uio->uio_iov->iov_base = (char *)(iov_base + cnt); 1281 uio->uio_iov->iov_len -= cnt; 1282 uio->uio_resid -= cnt; 1283 uio->uio_offset += cnt; 1284 return (0); 1285 } 1286 1287 1288 /* 1289 * File table truncate routine. 1290 */ 1291 static int 1292 vn_truncate(struct file *fp, off_t length, struct ucred *active_cred, 1293 struct thread *td) 1294 { 1295 struct vattr vattr; 1296 struct mount *mp; 1297 struct vnode *vp; 1298 void *rl_cookie; 1299 int error; 1300 1301 vp = fp->f_vnode; 1302 1303 /* 1304 * Lock the whole range for truncation. Otherwise split i/o 1305 * might happen partly before and partly after the truncation. 1306 */ 1307 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 1308 error = vn_start_write(vp, &mp, V_WAIT | PCATCH); 1309 if (error) 1310 goto out1; 1311 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1312 AUDIT_ARG_VNODE1(vp); 1313 if (vp->v_type == VDIR) { 1314 error = EISDIR; 1315 goto out; 1316 } 1317 #ifdef MAC 1318 error = mac_vnode_check_write(active_cred, fp->f_cred, vp); 1319 if (error) 1320 goto out; 1321 #endif 1322 error = vn_writechk(vp); 1323 if (error == 0) { 1324 VATTR_NULL(&vattr); 1325 vattr.va_size = length; 1326 if ((fp->f_flag & O_FSYNC) != 0) 1327 vattr.va_vaflags |= VA_SYNC; 1328 error = VOP_SETATTR(vp, &vattr, fp->f_cred); 1329 } 1330 out: 1331 VOP_UNLOCK(vp, 0); 1332 vn_finished_write(mp); 1333 out1: 1334 vn_rangelock_unlock(vp, rl_cookie); 1335 return (error); 1336 } 1337 1338 /* 1339 * File table vnode stat routine. 1340 */ 1341 static int 1342 vn_statfile(struct file *fp, struct stat *sb, struct ucred *active_cred, 1343 struct thread *td) 1344 { 1345 struct vnode *vp = fp->f_vnode; 1346 int error; 1347 1348 vn_lock(vp, LK_SHARED | LK_RETRY); 1349 error = vn_stat(vp, sb, active_cred, fp->f_cred, td); 1350 VOP_UNLOCK(vp, 0); 1351 1352 return (error); 1353 } 1354 1355 /* 1356 * Stat a vnode; implementation for the stat syscall 1357 */ 1358 int 1359 vn_stat(struct vnode *vp, struct stat *sb, struct ucred *active_cred, 1360 struct ucred *file_cred, struct thread *td) 1361 { 1362 struct vattr vattr; 1363 struct vattr *vap; 1364 int error; 1365 u_short mode; 1366 1367 AUDIT_ARG_VNODE1(vp); 1368 #ifdef MAC 1369 error = mac_vnode_check_stat(active_cred, file_cred, vp); 1370 if (error) 1371 return (error); 1372 #endif 1373 1374 vap = &vattr; 1375 1376 /* 1377 * Initialize defaults for new and unusual fields, so that file 1378 * systems which don't support these fields don't need to know 1379 * about them. 1380 */ 1381 vap->va_birthtime.tv_sec = -1; 1382 vap->va_birthtime.tv_nsec = 0; 1383 vap->va_fsid = VNOVAL; 1384 vap->va_rdev = NODEV; 1385 1386 error = VOP_GETATTR(vp, vap, active_cred); 1387 if (error) 1388 return (error); 1389 1390 /* 1391 * Zero the spare stat fields 1392 */ 1393 bzero(sb, sizeof *sb); 1394 1395 /* 1396 * Copy from vattr table 1397 */ 1398 if (vap->va_fsid != VNOVAL) 1399 sb->st_dev = vap->va_fsid; 1400 else 1401 sb->st_dev = vp->v_mount->mnt_stat.f_fsid.val[0]; 1402 sb->st_ino = vap->va_fileid; 1403 mode = vap->va_mode; 1404 switch (vap->va_type) { 1405 case VREG: 1406 mode |= S_IFREG; 1407 break; 1408 case VDIR: 1409 mode |= S_IFDIR; 1410 break; 1411 case VBLK: 1412 mode |= S_IFBLK; 1413 break; 1414 case VCHR: 1415 mode |= S_IFCHR; 1416 break; 1417 case VLNK: 1418 mode |= S_IFLNK; 1419 break; 1420 case VSOCK: 1421 mode |= S_IFSOCK; 1422 break; 1423 case VFIFO: 1424 mode |= S_IFIFO; 1425 break; 1426 default: 1427 return (EBADF); 1428 } 1429 sb->st_mode = mode; 1430 sb->st_nlink = vap->va_nlink; 1431 sb->st_uid = vap->va_uid; 1432 sb->st_gid = vap->va_gid; 1433 sb->st_rdev = vap->va_rdev; 1434 if (vap->va_size > OFF_MAX) 1435 return (EOVERFLOW); 1436 sb->st_size = vap->va_size; 1437 sb->st_atim = vap->va_atime; 1438 sb->st_mtim = vap->va_mtime; 1439 sb->st_ctim = vap->va_ctime; 1440 sb->st_birthtim = vap->va_birthtime; 1441 1442 /* 1443 * According to www.opengroup.org, the meaning of st_blksize is 1444 * "a filesystem-specific preferred I/O block size for this 1445 * object. In some filesystem types, this may vary from file 1446 * to file" 1447 * Use miminum/default of PAGE_SIZE (e.g. for VCHR). 1448 */ 1449 1450 sb->st_blksize = max(PAGE_SIZE, vap->va_blocksize); 1451 1452 sb->st_flags = vap->va_flags; 1453 if (priv_check(td, PRIV_VFS_GENERATION)) 1454 sb->st_gen = 0; 1455 else 1456 sb->st_gen = vap->va_gen; 1457 1458 sb->st_blocks = vap->va_bytes / S_BLKSIZE; 1459 return (0); 1460 } 1461 1462 /* 1463 * File table vnode ioctl routine. 1464 */ 1465 static int 1466 vn_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 1467 struct thread *td) 1468 { 1469 struct vattr vattr; 1470 struct vnode *vp; 1471 int error; 1472 1473 vp = fp->f_vnode; 1474 switch (vp->v_type) { 1475 case VDIR: 1476 case VREG: 1477 switch (com) { 1478 case FIONREAD: 1479 vn_lock(vp, LK_SHARED | LK_RETRY); 1480 error = VOP_GETATTR(vp, &vattr, active_cred); 1481 VOP_UNLOCK(vp, 0); 1482 if (error == 0) 1483 *(int *)data = vattr.va_size - fp->f_offset; 1484 return (error); 1485 case FIONBIO: 1486 case FIOASYNC: 1487 return (0); 1488 default: 1489 return (VOP_IOCTL(vp, com, data, fp->f_flag, 1490 active_cred, td)); 1491 } 1492 break; 1493 case VCHR: 1494 return (VOP_IOCTL(vp, com, data, fp->f_flag, 1495 active_cred, td)); 1496 default: 1497 return (ENOTTY); 1498 } 1499 } 1500 1501 /* 1502 * File table vnode poll routine. 1503 */ 1504 static int 1505 vn_poll(struct file *fp, int events, struct ucred *active_cred, 1506 struct thread *td) 1507 { 1508 struct vnode *vp; 1509 int error; 1510 1511 vp = fp->f_vnode; 1512 #ifdef MAC 1513 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1514 AUDIT_ARG_VNODE1(vp); 1515 error = mac_vnode_check_poll(active_cred, fp->f_cred, vp); 1516 VOP_UNLOCK(vp, 0); 1517 if (!error) 1518 #endif 1519 1520 error = VOP_POLL(vp, events, fp->f_cred, td); 1521 return (error); 1522 } 1523 1524 /* 1525 * Acquire the requested lock and then check for validity. LK_RETRY 1526 * permits vn_lock to return doomed vnodes. 1527 */ 1528 int 1529 _vn_lock(struct vnode *vp, int flags, char *file, int line) 1530 { 1531 int error; 1532 1533 VNASSERT((flags & LK_TYPE_MASK) != 0, vp, 1534 ("vn_lock: no locktype")); 1535 VNASSERT(vp->v_holdcnt != 0, vp, ("vn_lock: zero hold count")); 1536 retry: 1537 error = VOP_LOCK1(vp, flags, file, line); 1538 flags &= ~LK_INTERLOCK; /* Interlock is always dropped. */ 1539 KASSERT((flags & LK_RETRY) == 0 || error == 0, 1540 ("vn_lock: error %d incompatible with flags %#x", error, flags)); 1541 1542 if ((flags & LK_RETRY) == 0) { 1543 if (error == 0 && (vp->v_iflag & VI_DOOMED) != 0) { 1544 VOP_UNLOCK(vp, 0); 1545 error = ENOENT; 1546 } 1547 } else if (error != 0) 1548 goto retry; 1549 return (error); 1550 } 1551 1552 /* 1553 * File table vnode close routine. 1554 */ 1555 static int 1556 vn_closefile(struct file *fp, struct thread *td) 1557 { 1558 struct vnode *vp; 1559 struct flock lf; 1560 int error; 1561 bool ref; 1562 1563 vp = fp->f_vnode; 1564 fp->f_ops = &badfileops; 1565 ref= (fp->f_flag & FHASLOCK) != 0 && fp->f_type == DTYPE_VNODE; 1566 1567 error = vn_close1(vp, fp->f_flag, fp->f_cred, td, ref); 1568 1569 if (__predict_false(ref)) { 1570 lf.l_whence = SEEK_SET; 1571 lf.l_start = 0; 1572 lf.l_len = 0; 1573 lf.l_type = F_UNLCK; 1574 (void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, F_FLOCK); 1575 vrele(vp); 1576 } 1577 return (error); 1578 } 1579 1580 static bool 1581 vn_suspendable(struct mount *mp) 1582 { 1583 1584 return (mp->mnt_op->vfs_susp_clean != NULL); 1585 } 1586 1587 /* 1588 * Preparing to start a filesystem write operation. If the operation is 1589 * permitted, then we bump the count of operations in progress and 1590 * proceed. If a suspend request is in progress, we wait until the 1591 * suspension is over, and then proceed. 1592 */ 1593 static int 1594 vn_start_write_locked(struct mount *mp, int flags) 1595 { 1596 int error, mflags; 1597 1598 mtx_assert(MNT_MTX(mp), MA_OWNED); 1599 error = 0; 1600 1601 /* 1602 * Check on status of suspension. 1603 */ 1604 if ((curthread->td_pflags & TDP_IGNSUSP) == 0 || 1605 mp->mnt_susp_owner != curthread) { 1606 mflags = ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0 ? 1607 (flags & PCATCH) : 0) | (PUSER - 1); 1608 while ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { 1609 if (flags & V_NOWAIT) { 1610 error = EWOULDBLOCK; 1611 goto unlock; 1612 } 1613 error = msleep(&mp->mnt_flag, MNT_MTX(mp), mflags, 1614 "suspfs", 0); 1615 if (error) 1616 goto unlock; 1617 } 1618 } 1619 if (flags & V_XSLEEP) 1620 goto unlock; 1621 mp->mnt_writeopcount++; 1622 unlock: 1623 if (error != 0 || (flags & V_XSLEEP) != 0) 1624 MNT_REL(mp); 1625 MNT_IUNLOCK(mp); 1626 return (error); 1627 } 1628 1629 int 1630 vn_start_write(struct vnode *vp, struct mount **mpp, int flags) 1631 { 1632 struct mount *mp; 1633 int error; 1634 1635 KASSERT((flags & V_MNTREF) == 0 || (*mpp != NULL && vp == NULL), 1636 ("V_MNTREF requires mp")); 1637 1638 error = 0; 1639 /* 1640 * If a vnode is provided, get and return the mount point that 1641 * to which it will write. 1642 */ 1643 if (vp != NULL) { 1644 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) { 1645 *mpp = NULL; 1646 if (error != EOPNOTSUPP) 1647 return (error); 1648 return (0); 1649 } 1650 } 1651 if ((mp = *mpp) == NULL) 1652 return (0); 1653 1654 if (!vn_suspendable(mp)) { 1655 if (vp != NULL || (flags & V_MNTREF) != 0) 1656 vfs_rel(mp); 1657 return (0); 1658 } 1659 1660 /* 1661 * VOP_GETWRITEMOUNT() returns with the mp refcount held through 1662 * a vfs_ref(). 1663 * As long as a vnode is not provided we need to acquire a 1664 * refcount for the provided mountpoint too, in order to 1665 * emulate a vfs_ref(). 1666 */ 1667 MNT_ILOCK(mp); 1668 if (vp == NULL && (flags & V_MNTREF) == 0) 1669 MNT_REF(mp); 1670 1671 return (vn_start_write_locked(mp, flags)); 1672 } 1673 1674 /* 1675 * Secondary suspension. Used by operations such as vop_inactive 1676 * routines that are needed by the higher level functions. These 1677 * are allowed to proceed until all the higher level functions have 1678 * completed (indicated by mnt_writeopcount dropping to zero). At that 1679 * time, these operations are halted until the suspension is over. 1680 */ 1681 int 1682 vn_start_secondary_write(struct vnode *vp, struct mount **mpp, int flags) 1683 { 1684 struct mount *mp; 1685 int error; 1686 1687 KASSERT((flags & V_MNTREF) == 0 || (*mpp != NULL && vp == NULL), 1688 ("V_MNTREF requires mp")); 1689 1690 retry: 1691 if (vp != NULL) { 1692 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) { 1693 *mpp = NULL; 1694 if (error != EOPNOTSUPP) 1695 return (error); 1696 return (0); 1697 } 1698 } 1699 /* 1700 * If we are not suspended or have not yet reached suspended 1701 * mode, then let the operation proceed. 1702 */ 1703 if ((mp = *mpp) == NULL) 1704 return (0); 1705 1706 if (!vn_suspendable(mp)) { 1707 if (vp != NULL || (flags & V_MNTREF) != 0) 1708 vfs_rel(mp); 1709 return (0); 1710 } 1711 1712 /* 1713 * VOP_GETWRITEMOUNT() returns with the mp refcount held through 1714 * a vfs_ref(). 1715 * As long as a vnode is not provided we need to acquire a 1716 * refcount for the provided mountpoint too, in order to 1717 * emulate a vfs_ref(). 1718 */ 1719 MNT_ILOCK(mp); 1720 if (vp == NULL && (flags & V_MNTREF) == 0) 1721 MNT_REF(mp); 1722 if ((mp->mnt_kern_flag & (MNTK_SUSPENDED | MNTK_SUSPEND2)) == 0) { 1723 mp->mnt_secondary_writes++; 1724 mp->mnt_secondary_accwrites++; 1725 MNT_IUNLOCK(mp); 1726 return (0); 1727 } 1728 if (flags & V_NOWAIT) { 1729 MNT_REL(mp); 1730 MNT_IUNLOCK(mp); 1731 return (EWOULDBLOCK); 1732 } 1733 /* 1734 * Wait for the suspension to finish. 1735 */ 1736 error = msleep(&mp->mnt_flag, MNT_MTX(mp), (PUSER - 1) | PDROP | 1737 ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0 ? (flags & PCATCH) : 0), 1738 "suspfs", 0); 1739 vfs_rel(mp); 1740 if (error == 0) 1741 goto retry; 1742 return (error); 1743 } 1744 1745 /* 1746 * Filesystem write operation has completed. If we are suspending and this 1747 * operation is the last one, notify the suspender that the suspension is 1748 * now in effect. 1749 */ 1750 void 1751 vn_finished_write(struct mount *mp) 1752 { 1753 if (mp == NULL || !vn_suspendable(mp)) 1754 return; 1755 MNT_ILOCK(mp); 1756 MNT_REL(mp); 1757 mp->mnt_writeopcount--; 1758 if (mp->mnt_writeopcount < 0) 1759 panic("vn_finished_write: neg cnt"); 1760 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && 1761 mp->mnt_writeopcount <= 0) 1762 wakeup(&mp->mnt_writeopcount); 1763 MNT_IUNLOCK(mp); 1764 } 1765 1766 1767 /* 1768 * Filesystem secondary write operation has completed. If we are 1769 * suspending and this operation is the last one, notify the suspender 1770 * that the suspension is now in effect. 1771 */ 1772 void 1773 vn_finished_secondary_write(struct mount *mp) 1774 { 1775 if (mp == NULL || !vn_suspendable(mp)) 1776 return; 1777 MNT_ILOCK(mp); 1778 MNT_REL(mp); 1779 mp->mnt_secondary_writes--; 1780 if (mp->mnt_secondary_writes < 0) 1781 panic("vn_finished_secondary_write: neg cnt"); 1782 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && 1783 mp->mnt_secondary_writes <= 0) 1784 wakeup(&mp->mnt_secondary_writes); 1785 MNT_IUNLOCK(mp); 1786 } 1787 1788 1789 1790 /* 1791 * Request a filesystem to suspend write operations. 1792 */ 1793 int 1794 vfs_write_suspend(struct mount *mp, int flags) 1795 { 1796 int error; 1797 1798 MPASS(vn_suspendable(mp)); 1799 1800 MNT_ILOCK(mp); 1801 if (mp->mnt_susp_owner == curthread) { 1802 MNT_IUNLOCK(mp); 1803 return (EALREADY); 1804 } 1805 while (mp->mnt_kern_flag & MNTK_SUSPEND) 1806 msleep(&mp->mnt_flag, MNT_MTX(mp), PUSER - 1, "wsuspfs", 0); 1807 1808 /* 1809 * Unmount holds a write reference on the mount point. If we 1810 * own busy reference and drain for writers, we deadlock with 1811 * the reference draining in the unmount path. Callers of 1812 * vfs_write_suspend() must specify VS_SKIP_UNMOUNT if 1813 * vfs_busy() reference is owned and caller is not in the 1814 * unmount context. 1815 */ 1816 if ((flags & VS_SKIP_UNMOUNT) != 0 && 1817 (mp->mnt_kern_flag & MNTK_UNMOUNT) != 0) { 1818 MNT_IUNLOCK(mp); 1819 return (EBUSY); 1820 } 1821 1822 mp->mnt_kern_flag |= MNTK_SUSPEND; 1823 mp->mnt_susp_owner = curthread; 1824 if (mp->mnt_writeopcount > 0) 1825 (void) msleep(&mp->mnt_writeopcount, 1826 MNT_MTX(mp), (PUSER - 1)|PDROP, "suspwt", 0); 1827 else 1828 MNT_IUNLOCK(mp); 1829 if ((error = VFS_SYNC(mp, MNT_SUSPEND)) != 0) 1830 vfs_write_resume(mp, 0); 1831 return (error); 1832 } 1833 1834 /* 1835 * Request a filesystem to resume write operations. 1836 */ 1837 void 1838 vfs_write_resume(struct mount *mp, int flags) 1839 { 1840 1841 MPASS(vn_suspendable(mp)); 1842 1843 MNT_ILOCK(mp); 1844 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { 1845 KASSERT(mp->mnt_susp_owner == curthread, ("mnt_susp_owner")); 1846 mp->mnt_kern_flag &= ~(MNTK_SUSPEND | MNTK_SUSPEND2 | 1847 MNTK_SUSPENDED); 1848 mp->mnt_susp_owner = NULL; 1849 wakeup(&mp->mnt_writeopcount); 1850 wakeup(&mp->mnt_flag); 1851 curthread->td_pflags &= ~TDP_IGNSUSP; 1852 if ((flags & VR_START_WRITE) != 0) { 1853 MNT_REF(mp); 1854 mp->mnt_writeopcount++; 1855 } 1856 MNT_IUNLOCK(mp); 1857 if ((flags & VR_NO_SUSPCLR) == 0) 1858 VFS_SUSP_CLEAN(mp); 1859 } else if ((flags & VR_START_WRITE) != 0) { 1860 MNT_REF(mp); 1861 vn_start_write_locked(mp, 0); 1862 } else { 1863 MNT_IUNLOCK(mp); 1864 } 1865 } 1866 1867 /* 1868 * Helper loop around vfs_write_suspend() for filesystem unmount VFS 1869 * methods. 1870 */ 1871 int 1872 vfs_write_suspend_umnt(struct mount *mp) 1873 { 1874 int error; 1875 1876 MPASS(vn_suspendable(mp)); 1877 KASSERT((curthread->td_pflags & TDP_IGNSUSP) == 0, 1878 ("vfs_write_suspend_umnt: recursed")); 1879 1880 /* dounmount() already called vn_start_write(). */ 1881 for (;;) { 1882 vn_finished_write(mp); 1883 error = vfs_write_suspend(mp, 0); 1884 if (error != 0) { 1885 vn_start_write(NULL, &mp, V_WAIT); 1886 return (error); 1887 } 1888 MNT_ILOCK(mp); 1889 if ((mp->mnt_kern_flag & MNTK_SUSPENDED) != 0) 1890 break; 1891 MNT_IUNLOCK(mp); 1892 vn_start_write(NULL, &mp, V_WAIT); 1893 } 1894 mp->mnt_kern_flag &= ~(MNTK_SUSPENDED | MNTK_SUSPEND2); 1895 wakeup(&mp->mnt_flag); 1896 MNT_IUNLOCK(mp); 1897 curthread->td_pflags |= TDP_IGNSUSP; 1898 return (0); 1899 } 1900 1901 /* 1902 * Implement kqueues for files by translating it to vnode operation. 1903 */ 1904 static int 1905 vn_kqfilter(struct file *fp, struct knote *kn) 1906 { 1907 1908 return (VOP_KQFILTER(fp->f_vnode, kn)); 1909 } 1910 1911 /* 1912 * Simplified in-kernel wrapper calls for extended attribute access. 1913 * Both calls pass in a NULL credential, authorizing as "kernel" access. 1914 * Set IO_NODELOCKED in ioflg if the vnode is already locked. 1915 */ 1916 int 1917 vn_extattr_get(struct vnode *vp, int ioflg, int attrnamespace, 1918 const char *attrname, int *buflen, char *buf, struct thread *td) 1919 { 1920 struct uio auio; 1921 struct iovec iov; 1922 int error; 1923 1924 iov.iov_len = *buflen; 1925 iov.iov_base = buf; 1926 1927 auio.uio_iov = &iov; 1928 auio.uio_iovcnt = 1; 1929 auio.uio_rw = UIO_READ; 1930 auio.uio_segflg = UIO_SYSSPACE; 1931 auio.uio_td = td; 1932 auio.uio_offset = 0; 1933 auio.uio_resid = *buflen; 1934 1935 if ((ioflg & IO_NODELOCKED) == 0) 1936 vn_lock(vp, LK_SHARED | LK_RETRY); 1937 1938 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 1939 1940 /* authorize attribute retrieval as kernel */ 1941 error = VOP_GETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, NULL, 1942 td); 1943 1944 if ((ioflg & IO_NODELOCKED) == 0) 1945 VOP_UNLOCK(vp, 0); 1946 1947 if (error == 0) { 1948 *buflen = *buflen - auio.uio_resid; 1949 } 1950 1951 return (error); 1952 } 1953 1954 /* 1955 * XXX failure mode if partially written? 1956 */ 1957 int 1958 vn_extattr_set(struct vnode *vp, int ioflg, int attrnamespace, 1959 const char *attrname, int buflen, char *buf, struct thread *td) 1960 { 1961 struct uio auio; 1962 struct iovec iov; 1963 struct mount *mp; 1964 int error; 1965 1966 iov.iov_len = buflen; 1967 iov.iov_base = buf; 1968 1969 auio.uio_iov = &iov; 1970 auio.uio_iovcnt = 1; 1971 auio.uio_rw = UIO_WRITE; 1972 auio.uio_segflg = UIO_SYSSPACE; 1973 auio.uio_td = td; 1974 auio.uio_offset = 0; 1975 auio.uio_resid = buflen; 1976 1977 if ((ioflg & IO_NODELOCKED) == 0) { 1978 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) 1979 return (error); 1980 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1981 } 1982 1983 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 1984 1985 /* authorize attribute setting as kernel */ 1986 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, td); 1987 1988 if ((ioflg & IO_NODELOCKED) == 0) { 1989 vn_finished_write(mp); 1990 VOP_UNLOCK(vp, 0); 1991 } 1992 1993 return (error); 1994 } 1995 1996 int 1997 vn_extattr_rm(struct vnode *vp, int ioflg, int attrnamespace, 1998 const char *attrname, struct thread *td) 1999 { 2000 struct mount *mp; 2001 int error; 2002 2003 if ((ioflg & IO_NODELOCKED) == 0) { 2004 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) 2005 return (error); 2006 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2007 } 2008 2009 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 2010 2011 /* authorize attribute removal as kernel */ 2012 error = VOP_DELETEEXTATTR(vp, attrnamespace, attrname, NULL, td); 2013 if (error == EOPNOTSUPP) 2014 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, NULL, 2015 NULL, td); 2016 2017 if ((ioflg & IO_NODELOCKED) == 0) { 2018 vn_finished_write(mp); 2019 VOP_UNLOCK(vp, 0); 2020 } 2021 2022 return (error); 2023 } 2024 2025 static int 2026 vn_get_ino_alloc_vget(struct mount *mp, void *arg, int lkflags, 2027 struct vnode **rvp) 2028 { 2029 2030 return (VFS_VGET(mp, *(ino_t *)arg, lkflags, rvp)); 2031 } 2032 2033 int 2034 vn_vget_ino(struct vnode *vp, ino_t ino, int lkflags, struct vnode **rvp) 2035 { 2036 2037 return (vn_vget_ino_gen(vp, vn_get_ino_alloc_vget, &ino, 2038 lkflags, rvp)); 2039 } 2040 2041 int 2042 vn_vget_ino_gen(struct vnode *vp, vn_get_ino_t alloc, void *alloc_arg, 2043 int lkflags, struct vnode **rvp) 2044 { 2045 struct mount *mp; 2046 int ltype, error; 2047 2048 ASSERT_VOP_LOCKED(vp, "vn_vget_ino_get"); 2049 mp = vp->v_mount; 2050 ltype = VOP_ISLOCKED(vp); 2051 KASSERT(ltype == LK_EXCLUSIVE || ltype == LK_SHARED, 2052 ("vn_vget_ino: vp not locked")); 2053 error = vfs_busy(mp, MBF_NOWAIT); 2054 if (error != 0) { 2055 vfs_ref(mp); 2056 VOP_UNLOCK(vp, 0); 2057 error = vfs_busy(mp, 0); 2058 vn_lock(vp, ltype | LK_RETRY); 2059 vfs_rel(mp); 2060 if (error != 0) 2061 return (ENOENT); 2062 if (vp->v_iflag & VI_DOOMED) { 2063 vfs_unbusy(mp); 2064 return (ENOENT); 2065 } 2066 } 2067 VOP_UNLOCK(vp, 0); 2068 error = alloc(mp, alloc_arg, lkflags, rvp); 2069 vfs_unbusy(mp); 2070 if (*rvp != vp) 2071 vn_lock(vp, ltype | LK_RETRY); 2072 if (vp->v_iflag & VI_DOOMED) { 2073 if (error == 0) { 2074 if (*rvp == vp) 2075 vunref(vp); 2076 else 2077 vput(*rvp); 2078 } 2079 error = ENOENT; 2080 } 2081 return (error); 2082 } 2083 2084 int 2085 vn_rlimit_fsize(const struct vnode *vp, const struct uio *uio, 2086 struct thread *td) 2087 { 2088 2089 if (vp->v_type != VREG || td == NULL) 2090 return (0); 2091 if ((uoff_t)uio->uio_offset + uio->uio_resid > 2092 lim_cur(td, RLIMIT_FSIZE)) { 2093 PROC_LOCK(td->td_proc); 2094 kern_psignal(td->td_proc, SIGXFSZ); 2095 PROC_UNLOCK(td->td_proc); 2096 return (EFBIG); 2097 } 2098 return (0); 2099 } 2100 2101 int 2102 vn_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 2103 struct thread *td) 2104 { 2105 struct vnode *vp; 2106 2107 vp = fp->f_vnode; 2108 #ifdef AUDIT 2109 vn_lock(vp, LK_SHARED | LK_RETRY); 2110 AUDIT_ARG_VNODE1(vp); 2111 VOP_UNLOCK(vp, 0); 2112 #endif 2113 return (setfmode(td, active_cred, vp, mode)); 2114 } 2115 2116 int 2117 vn_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 2118 struct thread *td) 2119 { 2120 struct vnode *vp; 2121 2122 vp = fp->f_vnode; 2123 #ifdef AUDIT 2124 vn_lock(vp, LK_SHARED | LK_RETRY); 2125 AUDIT_ARG_VNODE1(vp); 2126 VOP_UNLOCK(vp, 0); 2127 #endif 2128 return (setfown(td, active_cred, vp, uid, gid)); 2129 } 2130 2131 void 2132 vn_pages_remove(struct vnode *vp, vm_pindex_t start, vm_pindex_t end) 2133 { 2134 vm_object_t object; 2135 2136 if ((object = vp->v_object) == NULL) 2137 return; 2138 VM_OBJECT_WLOCK(object); 2139 vm_object_page_remove(object, start, end, 0); 2140 VM_OBJECT_WUNLOCK(object); 2141 } 2142 2143 int 2144 vn_bmap_seekhole(struct vnode *vp, u_long cmd, off_t *off, struct ucred *cred) 2145 { 2146 struct vattr va; 2147 daddr_t bn, bnp; 2148 uint64_t bsize; 2149 off_t noff; 2150 int error; 2151 2152 KASSERT(cmd == FIOSEEKHOLE || cmd == FIOSEEKDATA, 2153 ("Wrong command %lu", cmd)); 2154 2155 if (vn_lock(vp, LK_SHARED) != 0) 2156 return (EBADF); 2157 if (vp->v_type != VREG) { 2158 error = ENOTTY; 2159 goto unlock; 2160 } 2161 error = VOP_GETATTR(vp, &va, cred); 2162 if (error != 0) 2163 goto unlock; 2164 noff = *off; 2165 if (noff >= va.va_size) { 2166 error = ENXIO; 2167 goto unlock; 2168 } 2169 bsize = vp->v_mount->mnt_stat.f_iosize; 2170 for (bn = noff / bsize; noff < va.va_size; bn++, noff += bsize) { 2171 error = VOP_BMAP(vp, bn, NULL, &bnp, NULL, NULL); 2172 if (error == EOPNOTSUPP) { 2173 error = ENOTTY; 2174 goto unlock; 2175 } 2176 if ((bnp == -1 && cmd == FIOSEEKHOLE) || 2177 (bnp != -1 && cmd == FIOSEEKDATA)) { 2178 noff = bn * bsize; 2179 if (noff < *off) 2180 noff = *off; 2181 goto unlock; 2182 } 2183 } 2184 if (noff > va.va_size) 2185 noff = va.va_size; 2186 /* noff == va.va_size. There is an implicit hole at the end of file. */ 2187 if (cmd == FIOSEEKDATA) 2188 error = ENXIO; 2189 unlock: 2190 VOP_UNLOCK(vp, 0); 2191 if (error == 0) 2192 *off = noff; 2193 return (error); 2194 } 2195 2196 int 2197 vn_seek(struct file *fp, off_t offset, int whence, struct thread *td) 2198 { 2199 struct ucred *cred; 2200 struct vnode *vp; 2201 struct vattr vattr; 2202 off_t foffset, size; 2203 int error, noneg; 2204 2205 cred = td->td_ucred; 2206 vp = fp->f_vnode; 2207 foffset = foffset_lock(fp, 0); 2208 noneg = (vp->v_type != VCHR); 2209 error = 0; 2210 switch (whence) { 2211 case L_INCR: 2212 if (noneg && 2213 (foffset < 0 || 2214 (offset > 0 && foffset > OFF_MAX - offset))) { 2215 error = EOVERFLOW; 2216 break; 2217 } 2218 offset += foffset; 2219 break; 2220 case L_XTND: 2221 vn_lock(vp, LK_SHARED | LK_RETRY); 2222 error = VOP_GETATTR(vp, &vattr, cred); 2223 VOP_UNLOCK(vp, 0); 2224 if (error) 2225 break; 2226 2227 /* 2228 * If the file references a disk device, then fetch 2229 * the media size and use that to determine the ending 2230 * offset. 2231 */ 2232 if (vattr.va_size == 0 && vp->v_type == VCHR && 2233 fo_ioctl(fp, DIOCGMEDIASIZE, &size, cred, td) == 0) 2234 vattr.va_size = size; 2235 if (noneg && 2236 (vattr.va_size > OFF_MAX || 2237 (offset > 0 && vattr.va_size > OFF_MAX - offset))) { 2238 error = EOVERFLOW; 2239 break; 2240 } 2241 offset += vattr.va_size; 2242 break; 2243 case L_SET: 2244 break; 2245 case SEEK_DATA: 2246 error = fo_ioctl(fp, FIOSEEKDATA, &offset, cred, td); 2247 break; 2248 case SEEK_HOLE: 2249 error = fo_ioctl(fp, FIOSEEKHOLE, &offset, cred, td); 2250 break; 2251 default: 2252 error = EINVAL; 2253 } 2254 if (error == 0 && noneg && offset < 0) 2255 error = EINVAL; 2256 if (error != 0) 2257 goto drop; 2258 VFS_KNOTE_UNLOCKED(vp, 0); 2259 td->td_uretoff.tdu_off = offset; 2260 drop: 2261 foffset_unlock(fp, offset, error != 0 ? FOF_NOUPDATE : 0); 2262 return (error); 2263 } 2264 2265 int 2266 vn_utimes_perm(struct vnode *vp, struct vattr *vap, struct ucred *cred, 2267 struct thread *td) 2268 { 2269 int error; 2270 2271 /* 2272 * Grant permission if the caller is the owner of the file, or 2273 * the super-user, or has ACL_WRITE_ATTRIBUTES permission on 2274 * on the file. If the time pointer is null, then write 2275 * permission on the file is also sufficient. 2276 * 2277 * From NFSv4.1, draft 21, 6.2.1.3.1, Discussion of Mask Attributes: 2278 * A user having ACL_WRITE_DATA or ACL_WRITE_ATTRIBUTES 2279 * will be allowed to set the times [..] to the current 2280 * server time. 2281 */ 2282 error = VOP_ACCESSX(vp, VWRITE_ATTRIBUTES, cred, td); 2283 if (error != 0 && (vap->va_vaflags & VA_UTIMES_NULL) != 0) 2284 error = VOP_ACCESS(vp, VWRITE, cred, td); 2285 return (error); 2286 } 2287 2288 int 2289 vn_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 2290 { 2291 struct vnode *vp; 2292 int error; 2293 2294 if (fp->f_type == DTYPE_FIFO) 2295 kif->kf_type = KF_TYPE_FIFO; 2296 else 2297 kif->kf_type = KF_TYPE_VNODE; 2298 vp = fp->f_vnode; 2299 vref(vp); 2300 FILEDESC_SUNLOCK(fdp); 2301 error = vn_fill_kinfo_vnode(vp, kif); 2302 vrele(vp); 2303 FILEDESC_SLOCK(fdp); 2304 return (error); 2305 } 2306 2307 static inline void 2308 vn_fill_junk(struct kinfo_file *kif) 2309 { 2310 size_t len, olen; 2311 2312 /* 2313 * Simulate vn_fullpath returning changing values for a given 2314 * vp during e.g. coredump. 2315 */ 2316 len = (arc4random() % (sizeof(kif->kf_path) - 2)) + 1; 2317 olen = strlen(kif->kf_path); 2318 if (len < olen) 2319 strcpy(&kif->kf_path[len - 1], "$"); 2320 else 2321 for (; olen < len; olen++) 2322 strcpy(&kif->kf_path[olen], "A"); 2323 } 2324 2325 int 2326 vn_fill_kinfo_vnode(struct vnode *vp, struct kinfo_file *kif) 2327 { 2328 struct vattr va; 2329 char *fullpath, *freepath; 2330 int error; 2331 2332 kif->kf_un.kf_file.kf_file_type = vntype_to_kinfo(vp->v_type); 2333 freepath = NULL; 2334 fullpath = "-"; 2335 error = vn_fullpath(curthread, vp, &fullpath, &freepath); 2336 if (error == 0) { 2337 strlcpy(kif->kf_path, fullpath, sizeof(kif->kf_path)); 2338 } 2339 if (freepath != NULL) 2340 free(freepath, M_TEMP); 2341 2342 KFAIL_POINT_CODE(DEBUG_FP, fill_kinfo_vnode__random_path, 2343 vn_fill_junk(kif); 2344 ); 2345 2346 /* 2347 * Retrieve vnode attributes. 2348 */ 2349 va.va_fsid = VNOVAL; 2350 va.va_rdev = NODEV; 2351 vn_lock(vp, LK_SHARED | LK_RETRY); 2352 error = VOP_GETATTR(vp, &va, curthread->td_ucred); 2353 VOP_UNLOCK(vp, 0); 2354 if (error != 0) 2355 return (error); 2356 if (va.va_fsid != VNOVAL) 2357 kif->kf_un.kf_file.kf_file_fsid = va.va_fsid; 2358 else 2359 kif->kf_un.kf_file.kf_file_fsid = 2360 vp->v_mount->mnt_stat.f_fsid.val[0]; 2361 kif->kf_un.kf_file.kf_file_fsid_freebsd11 = 2362 kif->kf_un.kf_file.kf_file_fsid; /* truncate */ 2363 kif->kf_un.kf_file.kf_file_fileid = va.va_fileid; 2364 kif->kf_un.kf_file.kf_file_mode = MAKEIMODE(va.va_type, va.va_mode); 2365 kif->kf_un.kf_file.kf_file_size = va.va_size; 2366 kif->kf_un.kf_file.kf_file_rdev = va.va_rdev; 2367 kif->kf_un.kf_file.kf_file_rdev_freebsd11 = 2368 kif->kf_un.kf_file.kf_file_rdev; /* truncate */ 2369 return (0); 2370 } 2371 2372 int 2373 vn_mmap(struct file *fp, vm_map_t map, vm_offset_t *addr, vm_size_t size, 2374 vm_prot_t prot, vm_prot_t cap_maxprot, int flags, vm_ooffset_t foff, 2375 struct thread *td) 2376 { 2377 #ifdef HWPMC_HOOKS 2378 struct pmckern_map_in pkm; 2379 #endif 2380 struct mount *mp; 2381 struct vnode *vp; 2382 vm_object_t object; 2383 vm_prot_t maxprot; 2384 boolean_t writecounted; 2385 int error; 2386 2387 #if defined(COMPAT_FREEBSD7) || defined(COMPAT_FREEBSD6) || \ 2388 defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4) 2389 /* 2390 * POSIX shared-memory objects are defined to have 2391 * kernel persistence, and are not defined to support 2392 * read(2)/write(2) -- or even open(2). Thus, we can 2393 * use MAP_ASYNC to trade on-disk coherence for speed. 2394 * The shm_open(3) library routine turns on the FPOSIXSHM 2395 * flag to request this behavior. 2396 */ 2397 if ((fp->f_flag & FPOSIXSHM) != 0) 2398 flags |= MAP_NOSYNC; 2399 #endif 2400 vp = fp->f_vnode; 2401 2402 /* 2403 * Ensure that file and memory protections are 2404 * compatible. Note that we only worry about 2405 * writability if mapping is shared; in this case, 2406 * current and max prot are dictated by the open file. 2407 * XXX use the vnode instead? Problem is: what 2408 * credentials do we use for determination? What if 2409 * proc does a setuid? 2410 */ 2411 mp = vp->v_mount; 2412 if (mp != NULL && (mp->mnt_flag & MNT_NOEXEC) != 0) { 2413 maxprot = VM_PROT_NONE; 2414 if ((prot & VM_PROT_EXECUTE) != 0) 2415 return (EACCES); 2416 } else 2417 maxprot = VM_PROT_EXECUTE; 2418 if ((fp->f_flag & FREAD) != 0) 2419 maxprot |= VM_PROT_READ; 2420 else if ((prot & VM_PROT_READ) != 0) 2421 return (EACCES); 2422 2423 /* 2424 * If we are sharing potential changes via MAP_SHARED and we 2425 * are trying to get write permission although we opened it 2426 * without asking for it, bail out. 2427 */ 2428 if ((flags & MAP_SHARED) != 0) { 2429 if ((fp->f_flag & FWRITE) != 0) 2430 maxprot |= VM_PROT_WRITE; 2431 else if ((prot & VM_PROT_WRITE) != 0) 2432 return (EACCES); 2433 } else { 2434 maxprot |= VM_PROT_WRITE; 2435 cap_maxprot |= VM_PROT_WRITE; 2436 } 2437 maxprot &= cap_maxprot; 2438 2439 /* 2440 * For regular files and shared memory, POSIX requires that 2441 * the value of foff be a legitimate offset within the data 2442 * object. In particular, negative offsets are invalid. 2443 * Blocking negative offsets and overflows here avoids 2444 * possible wraparound or user-level access into reserved 2445 * ranges of the data object later. In contrast, POSIX does 2446 * not dictate how offsets are used by device drivers, so in 2447 * the case of a device mapping a negative offset is passed 2448 * on. 2449 */ 2450 if ( 2451 #ifdef _LP64 2452 size > OFF_MAX || 2453 #endif 2454 foff < 0 || foff > OFF_MAX - size) 2455 return (EINVAL); 2456 2457 writecounted = FALSE; 2458 error = vm_mmap_vnode(td, size, prot, &maxprot, &flags, vp, 2459 &foff, &object, &writecounted); 2460 if (error != 0) 2461 return (error); 2462 error = vm_mmap_object(map, addr, size, prot, maxprot, flags, object, 2463 foff, writecounted, td); 2464 if (error != 0) { 2465 /* 2466 * If this mapping was accounted for in the vnode's 2467 * writecount, then undo that now. 2468 */ 2469 if (writecounted) 2470 vnode_pager_release_writecount(object, 0, size); 2471 vm_object_deallocate(object); 2472 } 2473 #ifdef HWPMC_HOOKS 2474 /* Inform hwpmc(4) if an executable is being mapped. */ 2475 if (PMC_HOOK_INSTALLED(PMC_FN_MMAP)) { 2476 if ((prot & VM_PROT_EXECUTE) != 0 && error == 0) { 2477 pkm.pm_file = vp; 2478 pkm.pm_address = (uintptr_t) *addr; 2479 PMC_CALL_HOOK_UNLOCKED(td, PMC_FN_MMAP, (void *) &pkm); 2480 } 2481 } 2482 #endif 2483 return (error); 2484 } 2485 2486 void 2487 vn_fsid(struct vnode *vp, struct vattr *va) 2488 { 2489 fsid_t *f; 2490 2491 f = &vp->v_mount->mnt_stat.f_fsid; 2492 va->va_fsid = (uint32_t)f->val[1]; 2493 va->va_fsid <<= sizeof(f->val[1]) * NBBY; 2494 va->va_fsid += (uint32_t)f->val[0]; 2495 } 2496