1 /*- 2 * Copyright (c) 1982, 1986, 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Copyright (c) 2012 Konstantin Belousov <kib@FreeBSD.org> 11 * Copyright (c) 2013, 2014 The FreeBSD Foundation 12 * 13 * Portions of this software were developed by Konstantin Belousov 14 * under sponsorship from the FreeBSD Foundation. 15 * 16 * Redistribution and use in source and binary forms, with or without 17 * modification, are permitted provided that the following conditions 18 * are met: 19 * 1. Redistributions of source code must retain the above copyright 20 * notice, this list of conditions and the following disclaimer. 21 * 2. Redistributions in binary form must reproduce the above copyright 22 * notice, this list of conditions and the following disclaimer in the 23 * documentation and/or other materials provided with the distribution. 24 * 3. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 * 40 * @(#)vfs_vnops.c 8.2 (Berkeley) 1/21/94 41 */ 42 43 #include <sys/cdefs.h> 44 __FBSDID("$FreeBSD$"); 45 46 #include "opt_hwpmc_hooks.h" 47 48 #include <sys/param.h> 49 #include <sys/systm.h> 50 #include <sys/disk.h> 51 #include <sys/fail.h> 52 #include <sys/fcntl.h> 53 #include <sys/file.h> 54 #include <sys/kdb.h> 55 #include <sys/stat.h> 56 #include <sys/priv.h> 57 #include <sys/proc.h> 58 #include <sys/limits.h> 59 #include <sys/lock.h> 60 #include <sys/mman.h> 61 #include <sys/mount.h> 62 #include <sys/mutex.h> 63 #include <sys/namei.h> 64 #include <sys/vnode.h> 65 #include <sys/bio.h> 66 #include <sys/buf.h> 67 #include <sys/filio.h> 68 #include <sys/resourcevar.h> 69 #include <sys/rwlock.h> 70 #include <sys/sx.h> 71 #include <sys/sysctl.h> 72 #include <sys/ttycom.h> 73 #include <sys/conf.h> 74 #include <sys/syslog.h> 75 #include <sys/unistd.h> 76 #include <sys/user.h> 77 78 #include <security/audit/audit.h> 79 #include <security/mac/mac_framework.h> 80 81 #include <vm/vm.h> 82 #include <vm/vm_extern.h> 83 #include <vm/pmap.h> 84 #include <vm/vm_map.h> 85 #include <vm/vm_object.h> 86 #include <vm/vm_page.h> 87 #include <vm/vnode_pager.h> 88 89 #ifdef HWPMC_HOOKS 90 #include <sys/pmckern.h> 91 #endif 92 93 static fo_rdwr_t vn_read; 94 static fo_rdwr_t vn_write; 95 static fo_rdwr_t vn_io_fault; 96 static fo_truncate_t vn_truncate; 97 static fo_ioctl_t vn_ioctl; 98 static fo_poll_t vn_poll; 99 static fo_kqfilter_t vn_kqfilter; 100 static fo_stat_t vn_statfile; 101 static fo_close_t vn_closefile; 102 static fo_mmap_t vn_mmap; 103 104 struct fileops vnops = { 105 .fo_read = vn_io_fault, 106 .fo_write = vn_io_fault, 107 .fo_truncate = vn_truncate, 108 .fo_ioctl = vn_ioctl, 109 .fo_poll = vn_poll, 110 .fo_kqfilter = vn_kqfilter, 111 .fo_stat = vn_statfile, 112 .fo_close = vn_closefile, 113 .fo_chmod = vn_chmod, 114 .fo_chown = vn_chown, 115 .fo_sendfile = vn_sendfile, 116 .fo_seek = vn_seek, 117 .fo_fill_kinfo = vn_fill_kinfo, 118 .fo_mmap = vn_mmap, 119 .fo_flags = DFLAG_PASSABLE | DFLAG_SEEKABLE 120 }; 121 122 static const int io_hold_cnt = 16; 123 static int vn_io_fault_enable = 1; 124 SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_enable, CTLFLAG_RW, 125 &vn_io_fault_enable, 0, "Enable vn_io_fault lock avoidance"); 126 static int vn_io_fault_prefault = 0; 127 SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_prefault, CTLFLAG_RW, 128 &vn_io_fault_prefault, 0, "Enable vn_io_fault prefaulting"); 129 static u_long vn_io_faults_cnt; 130 SYSCTL_ULONG(_debug, OID_AUTO, vn_io_faults, CTLFLAG_RD, 131 &vn_io_faults_cnt, 0, "Count of vn_io_fault lock avoidance triggers"); 132 133 /* 134 * Returns true if vn_io_fault mode of handling the i/o request should 135 * be used. 136 */ 137 static bool 138 do_vn_io_fault(struct vnode *vp, struct uio *uio) 139 { 140 struct mount *mp; 141 142 return (uio->uio_segflg == UIO_USERSPACE && vp->v_type == VREG && 143 (mp = vp->v_mount) != NULL && 144 (mp->mnt_kern_flag & MNTK_NO_IOPF) != 0 && vn_io_fault_enable); 145 } 146 147 /* 148 * Structure used to pass arguments to vn_io_fault1(), to do either 149 * file- or vnode-based I/O calls. 150 */ 151 struct vn_io_fault_args { 152 enum { 153 VN_IO_FAULT_FOP, 154 VN_IO_FAULT_VOP 155 } kind; 156 struct ucred *cred; 157 int flags; 158 union { 159 struct fop_args_tag { 160 struct file *fp; 161 fo_rdwr_t *doio; 162 } fop_args; 163 struct vop_args_tag { 164 struct vnode *vp; 165 } vop_args; 166 } args; 167 }; 168 169 static int vn_io_fault1(struct vnode *vp, struct uio *uio, 170 struct vn_io_fault_args *args, struct thread *td); 171 172 int 173 vn_open(ndp, flagp, cmode, fp) 174 struct nameidata *ndp; 175 int *flagp, cmode; 176 struct file *fp; 177 { 178 struct thread *td = ndp->ni_cnd.cn_thread; 179 180 return (vn_open_cred(ndp, flagp, cmode, 0, td->td_ucred, fp)); 181 } 182 183 /* 184 * Common code for vnode open operations via a name lookup. 185 * Lookup the vnode and invoke VOP_CREATE if needed. 186 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine. 187 * 188 * Note that this does NOT free nameidata for the successful case, 189 * due to the NDINIT being done elsewhere. 190 */ 191 int 192 vn_open_cred(struct nameidata *ndp, int *flagp, int cmode, u_int vn_open_flags, 193 struct ucred *cred, struct file *fp) 194 { 195 struct vnode *vp; 196 struct mount *mp; 197 struct thread *td = ndp->ni_cnd.cn_thread; 198 struct vattr vat; 199 struct vattr *vap = &vat; 200 int fmode, error; 201 202 restart: 203 fmode = *flagp; 204 if ((fmode & (O_CREAT | O_EXCL | O_DIRECTORY)) == (O_CREAT | 205 O_EXCL | O_DIRECTORY)) 206 return (EINVAL); 207 else if ((fmode & (O_CREAT | O_DIRECTORY)) == O_CREAT) { 208 ndp->ni_cnd.cn_nameiop = CREATE; 209 /* 210 * Set NOCACHE to avoid flushing the cache when 211 * rolling in many files at once. 212 */ 213 ndp->ni_cnd.cn_flags = ISOPEN | LOCKPARENT | LOCKLEAF | NOCACHE; 214 if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0) 215 ndp->ni_cnd.cn_flags |= FOLLOW; 216 if (!(vn_open_flags & VN_OPEN_NOAUDIT)) 217 ndp->ni_cnd.cn_flags |= AUDITVNODE1; 218 if (vn_open_flags & VN_OPEN_NOCAPCHECK) 219 ndp->ni_cnd.cn_flags |= NOCAPCHECK; 220 bwillwrite(); 221 if ((error = namei(ndp)) != 0) 222 return (error); 223 if (ndp->ni_vp == NULL) { 224 VATTR_NULL(vap); 225 vap->va_type = VREG; 226 vap->va_mode = cmode; 227 if (fmode & O_EXCL) 228 vap->va_vaflags |= VA_EXCLUSIVE; 229 if (vn_start_write(ndp->ni_dvp, &mp, V_NOWAIT) != 0) { 230 NDFREE(ndp, NDF_ONLY_PNBUF); 231 vput(ndp->ni_dvp); 232 if ((error = vn_start_write(NULL, &mp, 233 V_XSLEEP | PCATCH)) != 0) 234 return (error); 235 goto restart; 236 } 237 if ((vn_open_flags & VN_OPEN_NAMECACHE) != 0) 238 ndp->ni_cnd.cn_flags |= MAKEENTRY; 239 #ifdef MAC 240 error = mac_vnode_check_create(cred, ndp->ni_dvp, 241 &ndp->ni_cnd, vap); 242 if (error == 0) 243 #endif 244 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp, 245 &ndp->ni_cnd, vap); 246 vput(ndp->ni_dvp); 247 vn_finished_write(mp); 248 if (error) { 249 NDFREE(ndp, NDF_ONLY_PNBUF); 250 return (error); 251 } 252 fmode &= ~O_TRUNC; 253 vp = ndp->ni_vp; 254 } else { 255 if (ndp->ni_dvp == ndp->ni_vp) 256 vrele(ndp->ni_dvp); 257 else 258 vput(ndp->ni_dvp); 259 ndp->ni_dvp = NULL; 260 vp = ndp->ni_vp; 261 if (fmode & O_EXCL) { 262 error = EEXIST; 263 goto bad; 264 } 265 fmode &= ~O_CREAT; 266 } 267 } else { 268 ndp->ni_cnd.cn_nameiop = LOOKUP; 269 ndp->ni_cnd.cn_flags = ISOPEN | 270 ((fmode & O_NOFOLLOW) ? NOFOLLOW : FOLLOW) | LOCKLEAF; 271 if (!(fmode & FWRITE)) 272 ndp->ni_cnd.cn_flags |= LOCKSHARED; 273 if (!(vn_open_flags & VN_OPEN_NOAUDIT)) 274 ndp->ni_cnd.cn_flags |= AUDITVNODE1; 275 if (vn_open_flags & VN_OPEN_NOCAPCHECK) 276 ndp->ni_cnd.cn_flags |= NOCAPCHECK; 277 if ((error = namei(ndp)) != 0) 278 return (error); 279 vp = ndp->ni_vp; 280 } 281 error = vn_open_vnode(vp, fmode, cred, td, fp); 282 if (error) 283 goto bad; 284 *flagp = fmode; 285 return (0); 286 bad: 287 NDFREE(ndp, NDF_ONLY_PNBUF); 288 vput(vp); 289 *flagp = fmode; 290 ndp->ni_vp = NULL; 291 return (error); 292 } 293 294 /* 295 * Common code for vnode open operations once a vnode is located. 296 * Check permissions, and call the VOP_OPEN routine. 297 */ 298 int 299 vn_open_vnode(struct vnode *vp, int fmode, struct ucred *cred, 300 struct thread *td, struct file *fp) 301 { 302 accmode_t accmode; 303 struct flock lf; 304 int error, lock_flags, type; 305 306 if (vp->v_type == VLNK) 307 return (EMLINK); 308 if (vp->v_type == VSOCK) 309 return (EOPNOTSUPP); 310 if (vp->v_type != VDIR && fmode & O_DIRECTORY) 311 return (ENOTDIR); 312 accmode = 0; 313 if (fmode & (FWRITE | O_TRUNC)) { 314 if (vp->v_type == VDIR) 315 return (EISDIR); 316 accmode |= VWRITE; 317 } 318 if (fmode & FREAD) 319 accmode |= VREAD; 320 if (fmode & FEXEC) 321 accmode |= VEXEC; 322 if ((fmode & O_APPEND) && (fmode & FWRITE)) 323 accmode |= VAPPEND; 324 #ifdef MAC 325 if (fmode & O_CREAT) 326 accmode |= VCREAT; 327 if (fmode & O_VERIFY) 328 accmode |= VVERIFY; 329 error = mac_vnode_check_open(cred, vp, accmode); 330 if (error) 331 return (error); 332 333 accmode &= ~(VCREAT | VVERIFY); 334 #endif 335 if ((fmode & O_CREAT) == 0) { 336 if (accmode & VWRITE) { 337 error = vn_writechk(vp); 338 if (error) 339 return (error); 340 } 341 if (accmode) { 342 error = VOP_ACCESS(vp, accmode, cred, td); 343 if (error) 344 return (error); 345 } 346 } 347 if (vp->v_type == VFIFO && VOP_ISLOCKED(vp) != LK_EXCLUSIVE) 348 vn_lock(vp, LK_UPGRADE | LK_RETRY); 349 if ((error = VOP_OPEN(vp, fmode, cred, td, fp)) != 0) 350 return (error); 351 352 while ((fmode & (O_EXLOCK | O_SHLOCK)) != 0) { 353 KASSERT(fp != NULL, ("open with flock requires fp")); 354 if (fp->f_type != DTYPE_NONE && fp->f_type != DTYPE_VNODE) { 355 error = EOPNOTSUPP; 356 break; 357 } 358 lock_flags = VOP_ISLOCKED(vp); 359 VOP_UNLOCK(vp, 0); 360 lf.l_whence = SEEK_SET; 361 lf.l_start = 0; 362 lf.l_len = 0; 363 if (fmode & O_EXLOCK) 364 lf.l_type = F_WRLCK; 365 else 366 lf.l_type = F_RDLCK; 367 type = F_FLOCK; 368 if ((fmode & FNONBLOCK) == 0) 369 type |= F_WAIT; 370 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, type); 371 if (error == 0) 372 fp->f_flag |= FHASLOCK; 373 vn_lock(vp, lock_flags | LK_RETRY); 374 if (error != 0) 375 break; 376 if ((vp->v_iflag & VI_DOOMED) != 0) { 377 error = ENOENT; 378 break; 379 } 380 381 /* 382 * Another thread might have used this vnode as an 383 * executable while the vnode lock was dropped. 384 * Ensure the vnode is still able to be opened for 385 * writing after the lock has been obtained. 386 */ 387 if ((accmode & VWRITE) != 0) 388 error = vn_writechk(vp); 389 break; 390 } 391 392 if (error != 0) { 393 fp->f_flag |= FOPENFAILED; 394 fp->f_vnode = vp; 395 if (fp->f_ops == &badfileops) { 396 fp->f_type = DTYPE_VNODE; 397 fp->f_ops = &vnops; 398 } 399 vref(vp); 400 } else if ((fmode & FWRITE) != 0) { 401 VOP_ADD_WRITECOUNT(vp, 1); 402 CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d", 403 __func__, vp, vp->v_writecount); 404 } 405 ASSERT_VOP_LOCKED(vp, "vn_open_vnode"); 406 return (error); 407 } 408 409 /* 410 * Check for write permissions on the specified vnode. 411 * Prototype text segments cannot be written. 412 */ 413 int 414 vn_writechk(vp) 415 register struct vnode *vp; 416 { 417 418 ASSERT_VOP_LOCKED(vp, "vn_writechk"); 419 /* 420 * If there's shared text associated with 421 * the vnode, try to free it up once. If 422 * we fail, we can't allow writing. 423 */ 424 if (VOP_IS_TEXT(vp)) 425 return (ETXTBSY); 426 427 return (0); 428 } 429 430 /* 431 * Vnode close call 432 */ 433 static int 434 vn_close1(struct vnode *vp, int flags, struct ucred *file_cred, 435 struct thread *td, bool keep_ref) 436 { 437 struct mount *mp; 438 int error, lock_flags; 439 440 if (vp->v_type != VFIFO && (flags & FWRITE) == 0 && 441 MNT_EXTENDED_SHARED(vp->v_mount)) 442 lock_flags = LK_SHARED; 443 else 444 lock_flags = LK_EXCLUSIVE; 445 446 vn_start_write(vp, &mp, V_WAIT); 447 vn_lock(vp, lock_flags | LK_RETRY); 448 AUDIT_ARG_VNODE1(vp); 449 if ((flags & (FWRITE | FOPENFAILED)) == FWRITE) { 450 VNASSERT(vp->v_writecount > 0, vp, 451 ("vn_close: negative writecount")); 452 VOP_ADD_WRITECOUNT(vp, -1); 453 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d", 454 __func__, vp, vp->v_writecount); 455 } 456 error = VOP_CLOSE(vp, flags, file_cred, td); 457 if (keep_ref) 458 VOP_UNLOCK(vp, 0); 459 else 460 vput(vp); 461 vn_finished_write(mp); 462 return (error); 463 } 464 465 int 466 vn_close(struct vnode *vp, int flags, struct ucred *file_cred, 467 struct thread *td) 468 { 469 470 return (vn_close1(vp, flags, file_cred, td, false)); 471 } 472 473 /* 474 * Heuristic to detect sequential operation. 475 */ 476 static int 477 sequential_heuristic(struct uio *uio, struct file *fp) 478 { 479 480 ASSERT_VOP_LOCKED(fp->f_vnode, __func__); 481 if (fp->f_flag & FRDAHEAD) 482 return (fp->f_seqcount << IO_SEQSHIFT); 483 484 /* 485 * Offset 0 is handled specially. open() sets f_seqcount to 1 so 486 * that the first I/O is normally considered to be slightly 487 * sequential. Seeking to offset 0 doesn't change sequentiality 488 * unless previous seeks have reduced f_seqcount to 0, in which 489 * case offset 0 is not special. 490 */ 491 if ((uio->uio_offset == 0 && fp->f_seqcount > 0) || 492 uio->uio_offset == fp->f_nextoff) { 493 /* 494 * f_seqcount is in units of fixed-size blocks so that it 495 * depends mainly on the amount of sequential I/O and not 496 * much on the number of sequential I/O's. The fixed size 497 * of 16384 is hard-coded here since it is (not quite) just 498 * a magic size that works well here. This size is more 499 * closely related to the best I/O size for real disks than 500 * to any block size used by software. 501 */ 502 fp->f_seqcount += howmany(uio->uio_resid, 16384); 503 if (fp->f_seqcount > IO_SEQMAX) 504 fp->f_seqcount = IO_SEQMAX; 505 return (fp->f_seqcount << IO_SEQSHIFT); 506 } 507 508 /* Not sequential. Quickly draw-down sequentiality. */ 509 if (fp->f_seqcount > 1) 510 fp->f_seqcount = 1; 511 else 512 fp->f_seqcount = 0; 513 return (0); 514 } 515 516 /* 517 * Package up an I/O request on a vnode into a uio and do it. 518 */ 519 int 520 vn_rdwr(enum uio_rw rw, struct vnode *vp, void *base, int len, off_t offset, 521 enum uio_seg segflg, int ioflg, struct ucred *active_cred, 522 struct ucred *file_cred, ssize_t *aresid, struct thread *td) 523 { 524 struct uio auio; 525 struct iovec aiov; 526 struct mount *mp; 527 struct ucred *cred; 528 void *rl_cookie; 529 struct vn_io_fault_args args; 530 int error, lock_flags; 531 532 auio.uio_iov = &aiov; 533 auio.uio_iovcnt = 1; 534 aiov.iov_base = base; 535 aiov.iov_len = len; 536 auio.uio_resid = len; 537 auio.uio_offset = offset; 538 auio.uio_segflg = segflg; 539 auio.uio_rw = rw; 540 auio.uio_td = td; 541 error = 0; 542 543 if ((ioflg & IO_NODELOCKED) == 0) { 544 if ((ioflg & IO_RANGELOCKED) == 0) { 545 if (rw == UIO_READ) { 546 rl_cookie = vn_rangelock_rlock(vp, offset, 547 offset + len); 548 } else { 549 rl_cookie = vn_rangelock_wlock(vp, offset, 550 offset + len); 551 } 552 } else 553 rl_cookie = NULL; 554 mp = NULL; 555 if (rw == UIO_WRITE) { 556 if (vp->v_type != VCHR && 557 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) 558 != 0) 559 goto out; 560 if (MNT_SHARED_WRITES(mp) || 561 ((mp == NULL) && MNT_SHARED_WRITES(vp->v_mount))) 562 lock_flags = LK_SHARED; 563 else 564 lock_flags = LK_EXCLUSIVE; 565 } else 566 lock_flags = LK_SHARED; 567 vn_lock(vp, lock_flags | LK_RETRY); 568 } else 569 rl_cookie = NULL; 570 571 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 572 #ifdef MAC 573 if ((ioflg & IO_NOMACCHECK) == 0) { 574 if (rw == UIO_READ) 575 error = mac_vnode_check_read(active_cred, file_cred, 576 vp); 577 else 578 error = mac_vnode_check_write(active_cred, file_cred, 579 vp); 580 } 581 #endif 582 if (error == 0) { 583 if (file_cred != NULL) 584 cred = file_cred; 585 else 586 cred = active_cred; 587 if (do_vn_io_fault(vp, &auio)) { 588 args.kind = VN_IO_FAULT_VOP; 589 args.cred = cred; 590 args.flags = ioflg; 591 args.args.vop_args.vp = vp; 592 error = vn_io_fault1(vp, &auio, &args, td); 593 } else if (rw == UIO_READ) { 594 error = VOP_READ(vp, &auio, ioflg, cred); 595 } else /* if (rw == UIO_WRITE) */ { 596 error = VOP_WRITE(vp, &auio, ioflg, cred); 597 } 598 } 599 if (aresid) 600 *aresid = auio.uio_resid; 601 else 602 if (auio.uio_resid && error == 0) 603 error = EIO; 604 if ((ioflg & IO_NODELOCKED) == 0) { 605 VOP_UNLOCK(vp, 0); 606 if (mp != NULL) 607 vn_finished_write(mp); 608 } 609 out: 610 if (rl_cookie != NULL) 611 vn_rangelock_unlock(vp, rl_cookie); 612 return (error); 613 } 614 615 /* 616 * Package up an I/O request on a vnode into a uio and do it. The I/O 617 * request is split up into smaller chunks and we try to avoid saturating 618 * the buffer cache while potentially holding a vnode locked, so we 619 * check bwillwrite() before calling vn_rdwr(). We also call kern_yield() 620 * to give other processes a chance to lock the vnode (either other processes 621 * core'ing the same binary, or unrelated processes scanning the directory). 622 */ 623 int 624 vn_rdwr_inchunks(rw, vp, base, len, offset, segflg, ioflg, active_cred, 625 file_cred, aresid, td) 626 enum uio_rw rw; 627 struct vnode *vp; 628 void *base; 629 size_t len; 630 off_t offset; 631 enum uio_seg segflg; 632 int ioflg; 633 struct ucred *active_cred; 634 struct ucred *file_cred; 635 size_t *aresid; 636 struct thread *td; 637 { 638 int error = 0; 639 ssize_t iaresid; 640 641 do { 642 int chunk; 643 644 /* 645 * Force `offset' to a multiple of MAXBSIZE except possibly 646 * for the first chunk, so that filesystems only need to 647 * write full blocks except possibly for the first and last 648 * chunks. 649 */ 650 chunk = MAXBSIZE - (uoff_t)offset % MAXBSIZE; 651 652 if (chunk > len) 653 chunk = len; 654 if (rw != UIO_READ && vp->v_type == VREG) 655 bwillwrite(); 656 iaresid = 0; 657 error = vn_rdwr(rw, vp, base, chunk, offset, segflg, 658 ioflg, active_cred, file_cred, &iaresid, td); 659 len -= chunk; /* aresid calc already includes length */ 660 if (error) 661 break; 662 offset += chunk; 663 base = (char *)base + chunk; 664 kern_yield(PRI_USER); 665 } while (len); 666 if (aresid) 667 *aresid = len + iaresid; 668 return (error); 669 } 670 671 off_t 672 foffset_lock(struct file *fp, int flags) 673 { 674 struct mtx *mtxp; 675 off_t res; 676 677 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed")); 678 679 #if OFF_MAX <= LONG_MAX 680 /* 681 * Caller only wants the current f_offset value. Assume that 682 * the long and shorter integer types reads are atomic. 683 */ 684 if ((flags & FOF_NOLOCK) != 0) 685 return (fp->f_offset); 686 #endif 687 688 /* 689 * According to McKusick the vn lock was protecting f_offset here. 690 * It is now protected by the FOFFSET_LOCKED flag. 691 */ 692 mtxp = mtx_pool_find(mtxpool_sleep, fp); 693 mtx_lock(mtxp); 694 if ((flags & FOF_NOLOCK) == 0) { 695 while (fp->f_vnread_flags & FOFFSET_LOCKED) { 696 fp->f_vnread_flags |= FOFFSET_LOCK_WAITING; 697 msleep(&fp->f_vnread_flags, mtxp, PUSER -1, 698 "vofflock", 0); 699 } 700 fp->f_vnread_flags |= FOFFSET_LOCKED; 701 } 702 res = fp->f_offset; 703 mtx_unlock(mtxp); 704 return (res); 705 } 706 707 void 708 foffset_unlock(struct file *fp, off_t val, int flags) 709 { 710 struct mtx *mtxp; 711 712 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed")); 713 714 #if OFF_MAX <= LONG_MAX 715 if ((flags & FOF_NOLOCK) != 0) { 716 if ((flags & FOF_NOUPDATE) == 0) 717 fp->f_offset = val; 718 if ((flags & FOF_NEXTOFF) != 0) 719 fp->f_nextoff = val; 720 return; 721 } 722 #endif 723 724 mtxp = mtx_pool_find(mtxpool_sleep, fp); 725 mtx_lock(mtxp); 726 if ((flags & FOF_NOUPDATE) == 0) 727 fp->f_offset = val; 728 if ((flags & FOF_NEXTOFF) != 0) 729 fp->f_nextoff = val; 730 if ((flags & FOF_NOLOCK) == 0) { 731 KASSERT((fp->f_vnread_flags & FOFFSET_LOCKED) != 0, 732 ("Lost FOFFSET_LOCKED")); 733 if (fp->f_vnread_flags & FOFFSET_LOCK_WAITING) 734 wakeup(&fp->f_vnread_flags); 735 fp->f_vnread_flags = 0; 736 } 737 mtx_unlock(mtxp); 738 } 739 740 void 741 foffset_lock_uio(struct file *fp, struct uio *uio, int flags) 742 { 743 744 if ((flags & FOF_OFFSET) == 0) 745 uio->uio_offset = foffset_lock(fp, flags); 746 } 747 748 void 749 foffset_unlock_uio(struct file *fp, struct uio *uio, int flags) 750 { 751 752 if ((flags & FOF_OFFSET) == 0) 753 foffset_unlock(fp, uio->uio_offset, flags); 754 } 755 756 static int 757 get_advice(struct file *fp, struct uio *uio) 758 { 759 struct mtx *mtxp; 760 int ret; 761 762 ret = POSIX_FADV_NORMAL; 763 if (fp->f_advice == NULL || fp->f_vnode->v_type != VREG) 764 return (ret); 765 766 mtxp = mtx_pool_find(mtxpool_sleep, fp); 767 mtx_lock(mtxp); 768 if (fp->f_advice != NULL && 769 uio->uio_offset >= fp->f_advice->fa_start && 770 uio->uio_offset + uio->uio_resid <= fp->f_advice->fa_end) 771 ret = fp->f_advice->fa_advice; 772 mtx_unlock(mtxp); 773 return (ret); 774 } 775 776 /* 777 * File table vnode read routine. 778 */ 779 static int 780 vn_read(fp, uio, active_cred, flags, td) 781 struct file *fp; 782 struct uio *uio; 783 struct ucred *active_cred; 784 int flags; 785 struct thread *td; 786 { 787 struct vnode *vp; 788 off_t orig_offset; 789 int error, ioflag; 790 int advice; 791 792 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", 793 uio->uio_td, td)); 794 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET")); 795 vp = fp->f_vnode; 796 ioflag = 0; 797 if (fp->f_flag & FNONBLOCK) 798 ioflag |= IO_NDELAY; 799 if (fp->f_flag & O_DIRECT) 800 ioflag |= IO_DIRECT; 801 advice = get_advice(fp, uio); 802 vn_lock(vp, LK_SHARED | LK_RETRY); 803 804 switch (advice) { 805 case POSIX_FADV_NORMAL: 806 case POSIX_FADV_SEQUENTIAL: 807 case POSIX_FADV_NOREUSE: 808 ioflag |= sequential_heuristic(uio, fp); 809 break; 810 case POSIX_FADV_RANDOM: 811 /* Disable read-ahead for random I/O. */ 812 break; 813 } 814 orig_offset = uio->uio_offset; 815 816 #ifdef MAC 817 error = mac_vnode_check_read(active_cred, fp->f_cred, vp); 818 if (error == 0) 819 #endif 820 error = VOP_READ(vp, uio, ioflag, fp->f_cred); 821 fp->f_nextoff = uio->uio_offset; 822 VOP_UNLOCK(vp, 0); 823 if (error == 0 && advice == POSIX_FADV_NOREUSE && 824 orig_offset != uio->uio_offset) 825 /* 826 * Use POSIX_FADV_DONTNEED to flush pages and buffers 827 * for the backing file after a POSIX_FADV_NOREUSE 828 * read(2). 829 */ 830 error = VOP_ADVISE(vp, orig_offset, uio->uio_offset - 1, 831 POSIX_FADV_DONTNEED); 832 return (error); 833 } 834 835 /* 836 * File table vnode write routine. 837 */ 838 static int 839 vn_write(fp, uio, active_cred, flags, td) 840 struct file *fp; 841 struct uio *uio; 842 struct ucred *active_cred; 843 int flags; 844 struct thread *td; 845 { 846 struct vnode *vp; 847 struct mount *mp; 848 off_t orig_offset; 849 int error, ioflag, lock_flags; 850 int advice; 851 852 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", 853 uio->uio_td, td)); 854 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET")); 855 vp = fp->f_vnode; 856 if (vp->v_type == VREG) 857 bwillwrite(); 858 ioflag = IO_UNIT; 859 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 860 ioflag |= IO_APPEND; 861 if (fp->f_flag & FNONBLOCK) 862 ioflag |= IO_NDELAY; 863 if (fp->f_flag & O_DIRECT) 864 ioflag |= IO_DIRECT; 865 if ((fp->f_flag & O_FSYNC) || 866 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS))) 867 ioflag |= IO_SYNC; 868 mp = NULL; 869 if (vp->v_type != VCHR && 870 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0) 871 goto unlock; 872 873 advice = get_advice(fp, uio); 874 875 if (MNT_SHARED_WRITES(mp) || 876 (mp == NULL && MNT_SHARED_WRITES(vp->v_mount))) { 877 lock_flags = LK_SHARED; 878 } else { 879 lock_flags = LK_EXCLUSIVE; 880 } 881 882 vn_lock(vp, lock_flags | LK_RETRY); 883 switch (advice) { 884 case POSIX_FADV_NORMAL: 885 case POSIX_FADV_SEQUENTIAL: 886 case POSIX_FADV_NOREUSE: 887 ioflag |= sequential_heuristic(uio, fp); 888 break; 889 case POSIX_FADV_RANDOM: 890 /* XXX: Is this correct? */ 891 break; 892 } 893 orig_offset = uio->uio_offset; 894 895 #ifdef MAC 896 error = mac_vnode_check_write(active_cred, fp->f_cred, vp); 897 if (error == 0) 898 #endif 899 error = VOP_WRITE(vp, uio, ioflag, fp->f_cred); 900 fp->f_nextoff = uio->uio_offset; 901 VOP_UNLOCK(vp, 0); 902 if (vp->v_type != VCHR) 903 vn_finished_write(mp); 904 if (error == 0 && advice == POSIX_FADV_NOREUSE && 905 orig_offset != uio->uio_offset) 906 /* 907 * Use POSIX_FADV_DONTNEED to flush pages and buffers 908 * for the backing file after a POSIX_FADV_NOREUSE 909 * write(2). 910 */ 911 error = VOP_ADVISE(vp, orig_offset, uio->uio_offset - 1, 912 POSIX_FADV_DONTNEED); 913 unlock: 914 return (error); 915 } 916 917 /* 918 * The vn_io_fault() is a wrapper around vn_read() and vn_write() to 919 * prevent the following deadlock: 920 * 921 * Assume that the thread A reads from the vnode vp1 into userspace 922 * buffer buf1 backed by the pages of vnode vp2. If a page in buf1 is 923 * currently not resident, then system ends up with the call chain 924 * vn_read() -> VOP_READ(vp1) -> uiomove() -> [Page Fault] -> 925 * vm_fault(buf1) -> vnode_pager_getpages(vp2) -> VOP_GETPAGES(vp2) 926 * which establishes lock order vp1->vn_lock, then vp2->vn_lock. 927 * If, at the same time, thread B reads from vnode vp2 into buffer buf2 928 * backed by the pages of vnode vp1, and some page in buf2 is not 929 * resident, we get a reversed order vp2->vn_lock, then vp1->vn_lock. 930 * 931 * To prevent the lock order reversal and deadlock, vn_io_fault() does 932 * not allow page faults to happen during VOP_READ() or VOP_WRITE(). 933 * Instead, it first tries to do the whole range i/o with pagefaults 934 * disabled. If all pages in the i/o buffer are resident and mapped, 935 * VOP will succeed (ignoring the genuine filesystem errors). 936 * Otherwise, we get back EFAULT, and vn_io_fault() falls back to do 937 * i/o in chunks, with all pages in the chunk prefaulted and held 938 * using vm_fault_quick_hold_pages(). 939 * 940 * Filesystems using this deadlock avoidance scheme should use the 941 * array of the held pages from uio, saved in the curthread->td_ma, 942 * instead of doing uiomove(). A helper function 943 * vn_io_fault_uiomove() converts uiomove request into 944 * uiomove_fromphys() over td_ma array. 945 * 946 * Since vnode locks do not cover the whole i/o anymore, rangelocks 947 * make the current i/o request atomic with respect to other i/os and 948 * truncations. 949 */ 950 951 /* 952 * Decode vn_io_fault_args and perform the corresponding i/o. 953 */ 954 static int 955 vn_io_fault_doio(struct vn_io_fault_args *args, struct uio *uio, 956 struct thread *td) 957 { 958 959 switch (args->kind) { 960 case VN_IO_FAULT_FOP: 961 return ((args->args.fop_args.doio)(args->args.fop_args.fp, 962 uio, args->cred, args->flags, td)); 963 case VN_IO_FAULT_VOP: 964 if (uio->uio_rw == UIO_READ) { 965 return (VOP_READ(args->args.vop_args.vp, uio, 966 args->flags, args->cred)); 967 } else if (uio->uio_rw == UIO_WRITE) { 968 return (VOP_WRITE(args->args.vop_args.vp, uio, 969 args->flags, args->cred)); 970 } 971 break; 972 } 973 panic("vn_io_fault_doio: unknown kind of io %d %d", args->kind, 974 uio->uio_rw); 975 } 976 977 static int 978 vn_io_fault_touch(char *base, const struct uio *uio) 979 { 980 int r; 981 982 r = fubyte(base); 983 if (r == -1 || (uio->uio_rw == UIO_READ && subyte(base, r) == -1)) 984 return (EFAULT); 985 return (0); 986 } 987 988 static int 989 vn_io_fault_prefault_user(const struct uio *uio) 990 { 991 char *base; 992 const struct iovec *iov; 993 size_t len; 994 ssize_t resid; 995 int error, i; 996 997 KASSERT(uio->uio_segflg == UIO_USERSPACE, 998 ("vn_io_fault_prefault userspace")); 999 1000 error = i = 0; 1001 iov = uio->uio_iov; 1002 resid = uio->uio_resid; 1003 base = iov->iov_base; 1004 len = iov->iov_len; 1005 while (resid > 0) { 1006 error = vn_io_fault_touch(base, uio); 1007 if (error != 0) 1008 break; 1009 if (len < PAGE_SIZE) { 1010 if (len != 0) { 1011 error = vn_io_fault_touch(base + len - 1, uio); 1012 if (error != 0) 1013 break; 1014 resid -= len; 1015 } 1016 if (++i >= uio->uio_iovcnt) 1017 break; 1018 iov = uio->uio_iov + i; 1019 base = iov->iov_base; 1020 len = iov->iov_len; 1021 } else { 1022 len -= PAGE_SIZE; 1023 base += PAGE_SIZE; 1024 resid -= PAGE_SIZE; 1025 } 1026 } 1027 return (error); 1028 } 1029 1030 /* 1031 * Common code for vn_io_fault(), agnostic to the kind of i/o request. 1032 * Uses vn_io_fault_doio() to make the call to an actual i/o function. 1033 * Used from vn_rdwr() and vn_io_fault(), which encode the i/o request 1034 * into args and call vn_io_fault1() to handle faults during the user 1035 * mode buffer accesses. 1036 */ 1037 static int 1038 vn_io_fault1(struct vnode *vp, struct uio *uio, struct vn_io_fault_args *args, 1039 struct thread *td) 1040 { 1041 vm_page_t ma[io_hold_cnt + 2]; 1042 struct uio *uio_clone, short_uio; 1043 struct iovec short_iovec[1]; 1044 vm_page_t *prev_td_ma; 1045 vm_prot_t prot; 1046 vm_offset_t addr, end; 1047 size_t len, resid; 1048 ssize_t adv; 1049 int error, cnt, save, saveheld, prev_td_ma_cnt; 1050 1051 if (vn_io_fault_prefault) { 1052 error = vn_io_fault_prefault_user(uio); 1053 if (error != 0) 1054 return (error); /* Or ignore ? */ 1055 } 1056 1057 prot = uio->uio_rw == UIO_READ ? VM_PROT_WRITE : VM_PROT_READ; 1058 1059 /* 1060 * The UFS follows IO_UNIT directive and replays back both 1061 * uio_offset and uio_resid if an error is encountered during the 1062 * operation. But, since the iovec may be already advanced, 1063 * uio is still in an inconsistent state. 1064 * 1065 * Cache a copy of the original uio, which is advanced to the redo 1066 * point using UIO_NOCOPY below. 1067 */ 1068 uio_clone = cloneuio(uio); 1069 resid = uio->uio_resid; 1070 1071 short_uio.uio_segflg = UIO_USERSPACE; 1072 short_uio.uio_rw = uio->uio_rw; 1073 short_uio.uio_td = uio->uio_td; 1074 1075 save = vm_fault_disable_pagefaults(); 1076 error = vn_io_fault_doio(args, uio, td); 1077 if (error != EFAULT) 1078 goto out; 1079 1080 atomic_add_long(&vn_io_faults_cnt, 1); 1081 uio_clone->uio_segflg = UIO_NOCOPY; 1082 uiomove(NULL, resid - uio->uio_resid, uio_clone); 1083 uio_clone->uio_segflg = uio->uio_segflg; 1084 1085 saveheld = curthread_pflags_set(TDP_UIOHELD); 1086 prev_td_ma = td->td_ma; 1087 prev_td_ma_cnt = td->td_ma_cnt; 1088 1089 while (uio_clone->uio_resid != 0) { 1090 len = uio_clone->uio_iov->iov_len; 1091 if (len == 0) { 1092 KASSERT(uio_clone->uio_iovcnt >= 1, 1093 ("iovcnt underflow")); 1094 uio_clone->uio_iov++; 1095 uio_clone->uio_iovcnt--; 1096 continue; 1097 } 1098 if (len > io_hold_cnt * PAGE_SIZE) 1099 len = io_hold_cnt * PAGE_SIZE; 1100 addr = (uintptr_t)uio_clone->uio_iov->iov_base; 1101 end = round_page(addr + len); 1102 if (end < addr) { 1103 error = EFAULT; 1104 break; 1105 } 1106 cnt = atop(end - trunc_page(addr)); 1107 /* 1108 * A perfectly misaligned address and length could cause 1109 * both the start and the end of the chunk to use partial 1110 * page. +2 accounts for such a situation. 1111 */ 1112 cnt = vm_fault_quick_hold_pages(&td->td_proc->p_vmspace->vm_map, 1113 addr, len, prot, ma, io_hold_cnt + 2); 1114 if (cnt == -1) { 1115 error = EFAULT; 1116 break; 1117 } 1118 short_uio.uio_iov = &short_iovec[0]; 1119 short_iovec[0].iov_base = (void *)addr; 1120 short_uio.uio_iovcnt = 1; 1121 short_uio.uio_resid = short_iovec[0].iov_len = len; 1122 short_uio.uio_offset = uio_clone->uio_offset; 1123 td->td_ma = ma; 1124 td->td_ma_cnt = cnt; 1125 1126 error = vn_io_fault_doio(args, &short_uio, td); 1127 vm_page_unhold_pages(ma, cnt); 1128 adv = len - short_uio.uio_resid; 1129 1130 uio_clone->uio_iov->iov_base = 1131 (char *)uio_clone->uio_iov->iov_base + adv; 1132 uio_clone->uio_iov->iov_len -= adv; 1133 uio_clone->uio_resid -= adv; 1134 uio_clone->uio_offset += adv; 1135 1136 uio->uio_resid -= adv; 1137 uio->uio_offset += adv; 1138 1139 if (error != 0 || adv == 0) 1140 break; 1141 } 1142 td->td_ma = prev_td_ma; 1143 td->td_ma_cnt = prev_td_ma_cnt; 1144 curthread_pflags_restore(saveheld); 1145 out: 1146 vm_fault_enable_pagefaults(save); 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 vattr vattr; 1305 struct mount *mp; 1306 struct vnode *vp; 1307 void *rl_cookie; 1308 int error; 1309 1310 vp = fp->f_vnode; 1311 1312 /* 1313 * Lock the whole range for truncation. Otherwise split i/o 1314 * might happen partly before and partly after the truncation. 1315 */ 1316 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 1317 error = vn_start_write(vp, &mp, V_WAIT | PCATCH); 1318 if (error) 1319 goto out1; 1320 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1321 AUDIT_ARG_VNODE1(vp); 1322 if (vp->v_type == VDIR) { 1323 error = EISDIR; 1324 goto out; 1325 } 1326 #ifdef MAC 1327 error = mac_vnode_check_write(active_cred, fp->f_cred, vp); 1328 if (error) 1329 goto out; 1330 #endif 1331 error = vn_writechk(vp); 1332 if (error == 0) { 1333 VATTR_NULL(&vattr); 1334 vattr.va_size = length; 1335 if ((fp->f_flag & O_FSYNC) != 0) 1336 vattr.va_vaflags |= VA_SYNC; 1337 error = VOP_SETATTR(vp, &vattr, fp->f_cred); 1338 } 1339 out: 1340 VOP_UNLOCK(vp, 0); 1341 vn_finished_write(mp); 1342 out1: 1343 vn_rangelock_unlock(vp, rl_cookie); 1344 return (error); 1345 } 1346 1347 /* 1348 * File table vnode stat routine. 1349 */ 1350 static int 1351 vn_statfile(fp, sb, active_cred, td) 1352 struct file *fp; 1353 struct stat *sb; 1354 struct ucred *active_cred; 1355 struct thread *td; 1356 { 1357 struct vnode *vp = fp->f_vnode; 1358 int error; 1359 1360 vn_lock(vp, LK_SHARED | LK_RETRY); 1361 error = vn_stat(vp, sb, active_cred, fp->f_cred, td); 1362 VOP_UNLOCK(vp, 0); 1363 1364 return (error); 1365 } 1366 1367 /* 1368 * Stat a vnode; implementation for the stat syscall 1369 */ 1370 int 1371 vn_stat(vp, sb, active_cred, file_cred, td) 1372 struct vnode *vp; 1373 register struct stat *sb; 1374 struct ucred *active_cred; 1375 struct ucred *file_cred; 1376 struct thread *td; 1377 { 1378 struct vattr vattr; 1379 register struct vattr *vap; 1380 int error; 1381 u_short mode; 1382 1383 AUDIT_ARG_VNODE1(vp); 1384 #ifdef MAC 1385 error = mac_vnode_check_stat(active_cred, file_cred, vp); 1386 if (error) 1387 return (error); 1388 #endif 1389 1390 vap = &vattr; 1391 1392 /* 1393 * Initialize defaults for new and unusual fields, so that file 1394 * systems which don't support these fields don't need to know 1395 * about them. 1396 */ 1397 vap->va_birthtime.tv_sec = -1; 1398 vap->va_birthtime.tv_nsec = 0; 1399 vap->va_fsid = VNOVAL; 1400 vap->va_rdev = NODEV; 1401 1402 error = VOP_GETATTR(vp, vap, active_cred); 1403 if (error) 1404 return (error); 1405 1406 /* 1407 * Zero the spare stat fields 1408 */ 1409 bzero(sb, sizeof *sb); 1410 1411 /* 1412 * Copy from vattr table 1413 */ 1414 if (vap->va_fsid != VNOVAL) 1415 sb->st_dev = vap->va_fsid; 1416 else 1417 sb->st_dev = vp->v_mount->mnt_stat.f_fsid.val[0]; 1418 sb->st_ino = vap->va_fileid; 1419 mode = vap->va_mode; 1420 switch (vap->va_type) { 1421 case VREG: 1422 mode |= S_IFREG; 1423 break; 1424 case VDIR: 1425 mode |= S_IFDIR; 1426 break; 1427 case VBLK: 1428 mode |= S_IFBLK; 1429 break; 1430 case VCHR: 1431 mode |= S_IFCHR; 1432 break; 1433 case VLNK: 1434 mode |= S_IFLNK; 1435 break; 1436 case VSOCK: 1437 mode |= S_IFSOCK; 1438 break; 1439 case VFIFO: 1440 mode |= S_IFIFO; 1441 break; 1442 default: 1443 return (EBADF); 1444 } 1445 sb->st_mode = mode; 1446 sb->st_nlink = vap->va_nlink; 1447 sb->st_uid = vap->va_uid; 1448 sb->st_gid = vap->va_gid; 1449 sb->st_rdev = vap->va_rdev; 1450 if (vap->va_size > OFF_MAX) 1451 return (EOVERFLOW); 1452 sb->st_size = vap->va_size; 1453 sb->st_atim = vap->va_atime; 1454 sb->st_mtim = vap->va_mtime; 1455 sb->st_ctim = vap->va_ctime; 1456 sb->st_birthtim = vap->va_birthtime; 1457 1458 /* 1459 * According to www.opengroup.org, the meaning of st_blksize is 1460 * "a filesystem-specific preferred I/O block size for this 1461 * object. In some filesystem types, this may vary from file 1462 * to file" 1463 * Use miminum/default of PAGE_SIZE (e.g. for VCHR). 1464 */ 1465 1466 sb->st_blksize = max(PAGE_SIZE, vap->va_blocksize); 1467 1468 sb->st_flags = vap->va_flags; 1469 if (priv_check(td, PRIV_VFS_GENERATION)) 1470 sb->st_gen = 0; 1471 else 1472 sb->st_gen = vap->va_gen; 1473 1474 sb->st_blocks = vap->va_bytes / S_BLKSIZE; 1475 return (0); 1476 } 1477 1478 /* 1479 * File table vnode ioctl routine. 1480 */ 1481 static int 1482 vn_ioctl(fp, com, data, active_cred, td) 1483 struct file *fp; 1484 u_long com; 1485 void *data; 1486 struct ucred *active_cred; 1487 struct thread *td; 1488 { 1489 struct vattr vattr; 1490 struct vnode *vp; 1491 int error; 1492 1493 vp = fp->f_vnode; 1494 switch (vp->v_type) { 1495 case VDIR: 1496 case VREG: 1497 switch (com) { 1498 case FIONREAD: 1499 vn_lock(vp, LK_SHARED | LK_RETRY); 1500 error = VOP_GETATTR(vp, &vattr, active_cred); 1501 VOP_UNLOCK(vp, 0); 1502 if (error == 0) 1503 *(int *)data = vattr.va_size - fp->f_offset; 1504 return (error); 1505 case FIONBIO: 1506 case FIOASYNC: 1507 return (0); 1508 default: 1509 return (VOP_IOCTL(vp, com, data, fp->f_flag, 1510 active_cred, td)); 1511 } 1512 break; 1513 case VCHR: 1514 return (VOP_IOCTL(vp, com, data, fp->f_flag, 1515 active_cred, td)); 1516 default: 1517 return (ENOTTY); 1518 } 1519 } 1520 1521 /* 1522 * File table vnode poll routine. 1523 */ 1524 static int 1525 vn_poll(fp, events, active_cred, td) 1526 struct file *fp; 1527 int events; 1528 struct ucred *active_cred; 1529 struct thread *td; 1530 { 1531 struct vnode *vp; 1532 int error; 1533 1534 vp = fp->f_vnode; 1535 #ifdef MAC 1536 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1537 AUDIT_ARG_VNODE1(vp); 1538 error = mac_vnode_check_poll(active_cred, fp->f_cred, vp); 1539 VOP_UNLOCK(vp, 0); 1540 if (!error) 1541 #endif 1542 1543 error = VOP_POLL(vp, events, fp->f_cred, td); 1544 return (error); 1545 } 1546 1547 /* 1548 * Acquire the requested lock and then check for validity. LK_RETRY 1549 * permits vn_lock to return doomed vnodes. 1550 */ 1551 int 1552 _vn_lock(struct vnode *vp, int flags, char *file, int line) 1553 { 1554 int error; 1555 1556 VNASSERT((flags & LK_TYPE_MASK) != 0, vp, 1557 ("vn_lock: no locktype")); 1558 VNASSERT(vp->v_holdcnt != 0, vp, ("vn_lock: zero hold count")); 1559 retry: 1560 error = VOP_LOCK1(vp, flags, file, line); 1561 flags &= ~LK_INTERLOCK; /* Interlock is always dropped. */ 1562 KASSERT((flags & LK_RETRY) == 0 || error == 0, 1563 ("vn_lock: error %d incompatible with flags %#x", error, flags)); 1564 1565 if ((flags & LK_RETRY) == 0) { 1566 if (error == 0 && (vp->v_iflag & VI_DOOMED) != 0) { 1567 VOP_UNLOCK(vp, 0); 1568 error = ENOENT; 1569 } 1570 } else if (error != 0) 1571 goto retry; 1572 return (error); 1573 } 1574 1575 /* 1576 * File table vnode close routine. 1577 */ 1578 static int 1579 vn_closefile(struct file *fp, struct thread *td) 1580 { 1581 struct vnode *vp; 1582 struct flock lf; 1583 int error; 1584 bool ref; 1585 1586 vp = fp->f_vnode; 1587 fp->f_ops = &badfileops; 1588 ref= (fp->f_flag & FHASLOCK) != 0 && fp->f_type == DTYPE_VNODE; 1589 1590 error = vn_close1(vp, fp->f_flag, fp->f_cred, td, ref); 1591 1592 if (__predict_false(ref)) { 1593 lf.l_whence = SEEK_SET; 1594 lf.l_start = 0; 1595 lf.l_len = 0; 1596 lf.l_type = F_UNLCK; 1597 (void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, F_FLOCK); 1598 vrele(vp); 1599 } 1600 return (error); 1601 } 1602 1603 static bool 1604 vn_suspendable(struct mount *mp) 1605 { 1606 1607 return (mp->mnt_op->vfs_susp_clean != NULL); 1608 } 1609 1610 /* 1611 * Preparing to start a filesystem write operation. If the operation is 1612 * permitted, then we bump the count of operations in progress and 1613 * proceed. If a suspend request is in progress, we wait until the 1614 * suspension is over, and then proceed. 1615 */ 1616 static int 1617 vn_start_write_locked(struct mount *mp, int flags) 1618 { 1619 int error, mflags; 1620 1621 mtx_assert(MNT_MTX(mp), MA_OWNED); 1622 error = 0; 1623 1624 /* 1625 * Check on status of suspension. 1626 */ 1627 if ((curthread->td_pflags & TDP_IGNSUSP) == 0 || 1628 mp->mnt_susp_owner != curthread) { 1629 mflags = ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0 ? 1630 (flags & PCATCH) : 0) | (PUSER - 1); 1631 while ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { 1632 if (flags & V_NOWAIT) { 1633 error = EWOULDBLOCK; 1634 goto unlock; 1635 } 1636 error = msleep(&mp->mnt_flag, MNT_MTX(mp), mflags, 1637 "suspfs", 0); 1638 if (error) 1639 goto unlock; 1640 } 1641 } 1642 if (flags & V_XSLEEP) 1643 goto unlock; 1644 mp->mnt_writeopcount++; 1645 unlock: 1646 if (error != 0 || (flags & V_XSLEEP) != 0) 1647 MNT_REL(mp); 1648 MNT_IUNLOCK(mp); 1649 return (error); 1650 } 1651 1652 int 1653 vn_start_write(struct vnode *vp, struct mount **mpp, int flags) 1654 { 1655 struct mount *mp; 1656 int error; 1657 1658 KASSERT((flags & V_MNTREF) == 0 || (*mpp != NULL && vp == NULL), 1659 ("V_MNTREF requires mp")); 1660 1661 error = 0; 1662 /* 1663 * If a vnode is provided, get and return the mount point that 1664 * to which it will write. 1665 */ 1666 if (vp != NULL) { 1667 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) { 1668 *mpp = NULL; 1669 if (error != EOPNOTSUPP) 1670 return (error); 1671 return (0); 1672 } 1673 } 1674 if ((mp = *mpp) == NULL) 1675 return (0); 1676 1677 if (!vn_suspendable(mp)) { 1678 if (vp != NULL || (flags & V_MNTREF) != 0) 1679 vfs_rel(mp); 1680 return (0); 1681 } 1682 1683 /* 1684 * VOP_GETWRITEMOUNT() returns with the mp refcount held through 1685 * a vfs_ref(). 1686 * As long as a vnode is not provided we need to acquire a 1687 * refcount for the provided mountpoint too, in order to 1688 * emulate a vfs_ref(). 1689 */ 1690 MNT_ILOCK(mp); 1691 if (vp == NULL && (flags & V_MNTREF) == 0) 1692 MNT_REF(mp); 1693 1694 return (vn_start_write_locked(mp, flags)); 1695 } 1696 1697 /* 1698 * Secondary suspension. Used by operations such as vop_inactive 1699 * routines that are needed by the higher level functions. These 1700 * are allowed to proceed until all the higher level functions have 1701 * completed (indicated by mnt_writeopcount dropping to zero). At that 1702 * time, these operations are halted until the suspension is over. 1703 */ 1704 int 1705 vn_start_secondary_write(struct vnode *vp, struct mount **mpp, int flags) 1706 { 1707 struct mount *mp; 1708 int error; 1709 1710 KASSERT((flags & V_MNTREF) == 0 || (*mpp != NULL && vp == NULL), 1711 ("V_MNTREF requires mp")); 1712 1713 retry: 1714 if (vp != NULL) { 1715 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) { 1716 *mpp = NULL; 1717 if (error != EOPNOTSUPP) 1718 return (error); 1719 return (0); 1720 } 1721 } 1722 /* 1723 * If we are not suspended or have not yet reached suspended 1724 * mode, then let the operation proceed. 1725 */ 1726 if ((mp = *mpp) == NULL) 1727 return (0); 1728 1729 if (!vn_suspendable(mp)) { 1730 if (vp != NULL || (flags & V_MNTREF) != 0) 1731 vfs_rel(mp); 1732 return (0); 1733 } 1734 1735 /* 1736 * VOP_GETWRITEMOUNT() returns with the mp refcount held through 1737 * a vfs_ref(). 1738 * As long as a vnode is not provided we need to acquire a 1739 * refcount for the provided mountpoint too, in order to 1740 * emulate a vfs_ref(). 1741 */ 1742 MNT_ILOCK(mp); 1743 if (vp == NULL && (flags & V_MNTREF) == 0) 1744 MNT_REF(mp); 1745 if ((mp->mnt_kern_flag & (MNTK_SUSPENDED | MNTK_SUSPEND2)) == 0) { 1746 mp->mnt_secondary_writes++; 1747 mp->mnt_secondary_accwrites++; 1748 MNT_IUNLOCK(mp); 1749 return (0); 1750 } 1751 if (flags & V_NOWAIT) { 1752 MNT_REL(mp); 1753 MNT_IUNLOCK(mp); 1754 return (EWOULDBLOCK); 1755 } 1756 /* 1757 * Wait for the suspension to finish. 1758 */ 1759 error = msleep(&mp->mnt_flag, MNT_MTX(mp), (PUSER - 1) | PDROP | 1760 ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0 ? (flags & PCATCH) : 0), 1761 "suspfs", 0); 1762 vfs_rel(mp); 1763 if (error == 0) 1764 goto retry; 1765 return (error); 1766 } 1767 1768 /* 1769 * Filesystem write operation has completed. If we are suspending and this 1770 * operation is the last one, notify the suspender that the suspension is 1771 * now in effect. 1772 */ 1773 void 1774 vn_finished_write(mp) 1775 struct mount *mp; 1776 { 1777 if (mp == NULL || !vn_suspendable(mp)) 1778 return; 1779 MNT_ILOCK(mp); 1780 MNT_REL(mp); 1781 mp->mnt_writeopcount--; 1782 if (mp->mnt_writeopcount < 0) 1783 panic("vn_finished_write: neg cnt"); 1784 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && 1785 mp->mnt_writeopcount <= 0) 1786 wakeup(&mp->mnt_writeopcount); 1787 MNT_IUNLOCK(mp); 1788 } 1789 1790 1791 /* 1792 * Filesystem secondary write operation has completed. If we are 1793 * suspending and this operation is the last one, notify the suspender 1794 * that the suspension is now in effect. 1795 */ 1796 void 1797 vn_finished_secondary_write(mp) 1798 struct mount *mp; 1799 { 1800 if (mp == NULL || !vn_suspendable(mp)) 1801 return; 1802 MNT_ILOCK(mp); 1803 MNT_REL(mp); 1804 mp->mnt_secondary_writes--; 1805 if (mp->mnt_secondary_writes < 0) 1806 panic("vn_finished_secondary_write: neg cnt"); 1807 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && 1808 mp->mnt_secondary_writes <= 0) 1809 wakeup(&mp->mnt_secondary_writes); 1810 MNT_IUNLOCK(mp); 1811 } 1812 1813 1814 1815 /* 1816 * Request a filesystem to suspend write operations. 1817 */ 1818 int 1819 vfs_write_suspend(struct mount *mp, int flags) 1820 { 1821 int error; 1822 1823 MPASS(vn_suspendable(mp)); 1824 1825 MNT_ILOCK(mp); 1826 if (mp->mnt_susp_owner == curthread) { 1827 MNT_IUNLOCK(mp); 1828 return (EALREADY); 1829 } 1830 while (mp->mnt_kern_flag & MNTK_SUSPEND) 1831 msleep(&mp->mnt_flag, MNT_MTX(mp), PUSER - 1, "wsuspfs", 0); 1832 1833 /* 1834 * Unmount holds a write reference on the mount point. If we 1835 * own busy reference and drain for writers, we deadlock with 1836 * the reference draining in the unmount path. Callers of 1837 * vfs_write_suspend() must specify VS_SKIP_UNMOUNT if 1838 * vfs_busy() reference is owned and caller is not in the 1839 * unmount context. 1840 */ 1841 if ((flags & VS_SKIP_UNMOUNT) != 0 && 1842 (mp->mnt_kern_flag & MNTK_UNMOUNT) != 0) { 1843 MNT_IUNLOCK(mp); 1844 return (EBUSY); 1845 } 1846 1847 mp->mnt_kern_flag |= MNTK_SUSPEND; 1848 mp->mnt_susp_owner = curthread; 1849 if (mp->mnt_writeopcount > 0) 1850 (void) msleep(&mp->mnt_writeopcount, 1851 MNT_MTX(mp), (PUSER - 1)|PDROP, "suspwt", 0); 1852 else 1853 MNT_IUNLOCK(mp); 1854 if ((error = VFS_SYNC(mp, MNT_SUSPEND)) != 0) 1855 vfs_write_resume(mp, 0); 1856 return (error); 1857 } 1858 1859 /* 1860 * Request a filesystem to resume write operations. 1861 */ 1862 void 1863 vfs_write_resume(struct mount *mp, int flags) 1864 { 1865 1866 MPASS(vn_suspendable(mp)); 1867 1868 MNT_ILOCK(mp); 1869 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { 1870 KASSERT(mp->mnt_susp_owner == curthread, ("mnt_susp_owner")); 1871 mp->mnt_kern_flag &= ~(MNTK_SUSPEND | MNTK_SUSPEND2 | 1872 MNTK_SUSPENDED); 1873 mp->mnt_susp_owner = NULL; 1874 wakeup(&mp->mnt_writeopcount); 1875 wakeup(&mp->mnt_flag); 1876 curthread->td_pflags &= ~TDP_IGNSUSP; 1877 if ((flags & VR_START_WRITE) != 0) { 1878 MNT_REF(mp); 1879 mp->mnt_writeopcount++; 1880 } 1881 MNT_IUNLOCK(mp); 1882 if ((flags & VR_NO_SUSPCLR) == 0) 1883 VFS_SUSP_CLEAN(mp); 1884 } else if ((flags & VR_START_WRITE) != 0) { 1885 MNT_REF(mp); 1886 vn_start_write_locked(mp, 0); 1887 } else { 1888 MNT_IUNLOCK(mp); 1889 } 1890 } 1891 1892 /* 1893 * Helper loop around vfs_write_suspend() for filesystem unmount VFS 1894 * methods. 1895 */ 1896 int 1897 vfs_write_suspend_umnt(struct mount *mp) 1898 { 1899 int error; 1900 1901 MPASS(vn_suspendable(mp)); 1902 KASSERT((curthread->td_pflags & TDP_IGNSUSP) == 0, 1903 ("vfs_write_suspend_umnt: recursed")); 1904 1905 /* dounmount() already called vn_start_write(). */ 1906 for (;;) { 1907 vn_finished_write(mp); 1908 error = vfs_write_suspend(mp, 0); 1909 if (error != 0) { 1910 vn_start_write(NULL, &mp, V_WAIT); 1911 return (error); 1912 } 1913 MNT_ILOCK(mp); 1914 if ((mp->mnt_kern_flag & MNTK_SUSPENDED) != 0) 1915 break; 1916 MNT_IUNLOCK(mp); 1917 vn_start_write(NULL, &mp, V_WAIT); 1918 } 1919 mp->mnt_kern_flag &= ~(MNTK_SUSPENDED | MNTK_SUSPEND2); 1920 wakeup(&mp->mnt_flag); 1921 MNT_IUNLOCK(mp); 1922 curthread->td_pflags |= TDP_IGNSUSP; 1923 return (0); 1924 } 1925 1926 /* 1927 * Implement kqueues for files by translating it to vnode operation. 1928 */ 1929 static int 1930 vn_kqfilter(struct file *fp, struct knote *kn) 1931 { 1932 1933 return (VOP_KQFILTER(fp->f_vnode, kn)); 1934 } 1935 1936 /* 1937 * Simplified in-kernel wrapper calls for extended attribute access. 1938 * Both calls pass in a NULL credential, authorizing as "kernel" access. 1939 * Set IO_NODELOCKED in ioflg if the vnode is already locked. 1940 */ 1941 int 1942 vn_extattr_get(struct vnode *vp, int ioflg, int attrnamespace, 1943 const char *attrname, int *buflen, char *buf, struct thread *td) 1944 { 1945 struct uio auio; 1946 struct iovec iov; 1947 int error; 1948 1949 iov.iov_len = *buflen; 1950 iov.iov_base = buf; 1951 1952 auio.uio_iov = &iov; 1953 auio.uio_iovcnt = 1; 1954 auio.uio_rw = UIO_READ; 1955 auio.uio_segflg = UIO_SYSSPACE; 1956 auio.uio_td = td; 1957 auio.uio_offset = 0; 1958 auio.uio_resid = *buflen; 1959 1960 if ((ioflg & IO_NODELOCKED) == 0) 1961 vn_lock(vp, LK_SHARED | LK_RETRY); 1962 1963 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 1964 1965 /* authorize attribute retrieval as kernel */ 1966 error = VOP_GETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, NULL, 1967 td); 1968 1969 if ((ioflg & IO_NODELOCKED) == 0) 1970 VOP_UNLOCK(vp, 0); 1971 1972 if (error == 0) { 1973 *buflen = *buflen - auio.uio_resid; 1974 } 1975 1976 return (error); 1977 } 1978 1979 /* 1980 * XXX failure mode if partially written? 1981 */ 1982 int 1983 vn_extattr_set(struct vnode *vp, int ioflg, int attrnamespace, 1984 const char *attrname, int buflen, char *buf, struct thread *td) 1985 { 1986 struct uio auio; 1987 struct iovec iov; 1988 struct mount *mp; 1989 int error; 1990 1991 iov.iov_len = buflen; 1992 iov.iov_base = buf; 1993 1994 auio.uio_iov = &iov; 1995 auio.uio_iovcnt = 1; 1996 auio.uio_rw = UIO_WRITE; 1997 auio.uio_segflg = UIO_SYSSPACE; 1998 auio.uio_td = td; 1999 auio.uio_offset = 0; 2000 auio.uio_resid = buflen; 2001 2002 if ((ioflg & IO_NODELOCKED) == 0) { 2003 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) 2004 return (error); 2005 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2006 } 2007 2008 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 2009 2010 /* authorize attribute setting as kernel */ 2011 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, td); 2012 2013 if ((ioflg & IO_NODELOCKED) == 0) { 2014 vn_finished_write(mp); 2015 VOP_UNLOCK(vp, 0); 2016 } 2017 2018 return (error); 2019 } 2020 2021 int 2022 vn_extattr_rm(struct vnode *vp, int ioflg, int attrnamespace, 2023 const char *attrname, struct thread *td) 2024 { 2025 struct mount *mp; 2026 int error; 2027 2028 if ((ioflg & IO_NODELOCKED) == 0) { 2029 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) 2030 return (error); 2031 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2032 } 2033 2034 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 2035 2036 /* authorize attribute removal as kernel */ 2037 error = VOP_DELETEEXTATTR(vp, attrnamespace, attrname, NULL, td); 2038 if (error == EOPNOTSUPP) 2039 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, NULL, 2040 NULL, td); 2041 2042 if ((ioflg & IO_NODELOCKED) == 0) { 2043 vn_finished_write(mp); 2044 VOP_UNLOCK(vp, 0); 2045 } 2046 2047 return (error); 2048 } 2049 2050 static int 2051 vn_get_ino_alloc_vget(struct mount *mp, void *arg, int lkflags, 2052 struct vnode **rvp) 2053 { 2054 2055 return (VFS_VGET(mp, *(ino_t *)arg, lkflags, rvp)); 2056 } 2057 2058 int 2059 vn_vget_ino(struct vnode *vp, ino_t ino, int lkflags, struct vnode **rvp) 2060 { 2061 2062 return (vn_vget_ino_gen(vp, vn_get_ino_alloc_vget, &ino, 2063 lkflags, rvp)); 2064 } 2065 2066 int 2067 vn_vget_ino_gen(struct vnode *vp, vn_get_ino_t alloc, void *alloc_arg, 2068 int lkflags, struct vnode **rvp) 2069 { 2070 struct mount *mp; 2071 int ltype, error; 2072 2073 ASSERT_VOP_LOCKED(vp, "vn_vget_ino_get"); 2074 mp = vp->v_mount; 2075 ltype = VOP_ISLOCKED(vp); 2076 KASSERT(ltype == LK_EXCLUSIVE || ltype == LK_SHARED, 2077 ("vn_vget_ino: vp not locked")); 2078 error = vfs_busy(mp, MBF_NOWAIT); 2079 if (error != 0) { 2080 vfs_ref(mp); 2081 VOP_UNLOCK(vp, 0); 2082 error = vfs_busy(mp, 0); 2083 vn_lock(vp, ltype | LK_RETRY); 2084 vfs_rel(mp); 2085 if (error != 0) 2086 return (ENOENT); 2087 if (vp->v_iflag & VI_DOOMED) { 2088 vfs_unbusy(mp); 2089 return (ENOENT); 2090 } 2091 } 2092 VOP_UNLOCK(vp, 0); 2093 error = alloc(mp, alloc_arg, lkflags, rvp); 2094 vfs_unbusy(mp); 2095 if (*rvp != vp) 2096 vn_lock(vp, ltype | LK_RETRY); 2097 if (vp->v_iflag & VI_DOOMED) { 2098 if (error == 0) { 2099 if (*rvp == vp) 2100 vunref(vp); 2101 else 2102 vput(*rvp); 2103 } 2104 error = ENOENT; 2105 } 2106 return (error); 2107 } 2108 2109 int 2110 vn_rlimit_fsize(const struct vnode *vp, const struct uio *uio, 2111 struct thread *td) 2112 { 2113 2114 if (vp->v_type != VREG || td == NULL) 2115 return (0); 2116 if ((uoff_t)uio->uio_offset + uio->uio_resid > 2117 lim_cur(td, RLIMIT_FSIZE)) { 2118 PROC_LOCK(td->td_proc); 2119 kern_psignal(td->td_proc, SIGXFSZ); 2120 PROC_UNLOCK(td->td_proc); 2121 return (EFBIG); 2122 } 2123 return (0); 2124 } 2125 2126 int 2127 vn_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 2128 struct thread *td) 2129 { 2130 struct vnode *vp; 2131 2132 vp = fp->f_vnode; 2133 #ifdef AUDIT 2134 vn_lock(vp, LK_SHARED | LK_RETRY); 2135 AUDIT_ARG_VNODE1(vp); 2136 VOP_UNLOCK(vp, 0); 2137 #endif 2138 return (setfmode(td, active_cred, vp, mode)); 2139 } 2140 2141 int 2142 vn_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 2143 struct thread *td) 2144 { 2145 struct vnode *vp; 2146 2147 vp = fp->f_vnode; 2148 #ifdef AUDIT 2149 vn_lock(vp, LK_SHARED | LK_RETRY); 2150 AUDIT_ARG_VNODE1(vp); 2151 VOP_UNLOCK(vp, 0); 2152 #endif 2153 return (setfown(td, active_cred, vp, uid, gid)); 2154 } 2155 2156 void 2157 vn_pages_remove(struct vnode *vp, vm_pindex_t start, vm_pindex_t end) 2158 { 2159 vm_object_t object; 2160 2161 if ((object = vp->v_object) == NULL) 2162 return; 2163 VM_OBJECT_WLOCK(object); 2164 vm_object_page_remove(object, start, end, 0); 2165 VM_OBJECT_WUNLOCK(object); 2166 } 2167 2168 int 2169 vn_bmap_seekhole(struct vnode *vp, u_long cmd, off_t *off, struct ucred *cred) 2170 { 2171 struct vattr va; 2172 daddr_t bn, bnp; 2173 uint64_t bsize; 2174 off_t noff; 2175 int error; 2176 2177 KASSERT(cmd == FIOSEEKHOLE || cmd == FIOSEEKDATA, 2178 ("Wrong command %lu", cmd)); 2179 2180 if (vn_lock(vp, LK_SHARED) != 0) 2181 return (EBADF); 2182 if (vp->v_type != VREG) { 2183 error = ENOTTY; 2184 goto unlock; 2185 } 2186 error = VOP_GETATTR(vp, &va, cred); 2187 if (error != 0) 2188 goto unlock; 2189 noff = *off; 2190 if (noff >= va.va_size) { 2191 error = ENXIO; 2192 goto unlock; 2193 } 2194 bsize = vp->v_mount->mnt_stat.f_iosize; 2195 for (bn = noff / bsize; noff < va.va_size; bn++, noff += bsize) { 2196 error = VOP_BMAP(vp, bn, NULL, &bnp, NULL, NULL); 2197 if (error == EOPNOTSUPP) { 2198 error = ENOTTY; 2199 goto unlock; 2200 } 2201 if ((bnp == -1 && cmd == FIOSEEKHOLE) || 2202 (bnp != -1 && cmd == FIOSEEKDATA)) { 2203 noff = bn * bsize; 2204 if (noff < *off) 2205 noff = *off; 2206 goto unlock; 2207 } 2208 } 2209 if (noff > va.va_size) 2210 noff = va.va_size; 2211 /* noff == va.va_size. There is an implicit hole at the end of file. */ 2212 if (cmd == FIOSEEKDATA) 2213 error = ENXIO; 2214 unlock: 2215 VOP_UNLOCK(vp, 0); 2216 if (error == 0) 2217 *off = noff; 2218 return (error); 2219 } 2220 2221 int 2222 vn_seek(struct file *fp, off_t offset, int whence, struct thread *td) 2223 { 2224 struct ucred *cred; 2225 struct vnode *vp; 2226 struct vattr vattr; 2227 off_t foffset, size; 2228 int error, noneg; 2229 2230 cred = td->td_ucred; 2231 vp = fp->f_vnode; 2232 foffset = foffset_lock(fp, 0); 2233 noneg = (vp->v_type != VCHR); 2234 error = 0; 2235 switch (whence) { 2236 case L_INCR: 2237 if (noneg && 2238 (foffset < 0 || 2239 (offset > 0 && foffset > OFF_MAX - offset))) { 2240 error = EOVERFLOW; 2241 break; 2242 } 2243 offset += foffset; 2244 break; 2245 case L_XTND: 2246 vn_lock(vp, LK_SHARED | LK_RETRY); 2247 error = VOP_GETATTR(vp, &vattr, cred); 2248 VOP_UNLOCK(vp, 0); 2249 if (error) 2250 break; 2251 2252 /* 2253 * If the file references a disk device, then fetch 2254 * the media size and use that to determine the ending 2255 * offset. 2256 */ 2257 if (vattr.va_size == 0 && vp->v_type == VCHR && 2258 fo_ioctl(fp, DIOCGMEDIASIZE, &size, cred, td) == 0) 2259 vattr.va_size = size; 2260 if (noneg && 2261 (vattr.va_size > OFF_MAX || 2262 (offset > 0 && vattr.va_size > OFF_MAX - offset))) { 2263 error = EOVERFLOW; 2264 break; 2265 } 2266 offset += vattr.va_size; 2267 break; 2268 case L_SET: 2269 break; 2270 case SEEK_DATA: 2271 error = fo_ioctl(fp, FIOSEEKDATA, &offset, cred, td); 2272 break; 2273 case SEEK_HOLE: 2274 error = fo_ioctl(fp, FIOSEEKHOLE, &offset, cred, td); 2275 break; 2276 default: 2277 error = EINVAL; 2278 } 2279 if (error == 0 && noneg && offset < 0) 2280 error = EINVAL; 2281 if (error != 0) 2282 goto drop; 2283 VFS_KNOTE_UNLOCKED(vp, 0); 2284 td->td_uretoff.tdu_off = offset; 2285 drop: 2286 foffset_unlock(fp, offset, error != 0 ? FOF_NOUPDATE : 0); 2287 return (error); 2288 } 2289 2290 int 2291 vn_utimes_perm(struct vnode *vp, struct vattr *vap, struct ucred *cred, 2292 struct thread *td) 2293 { 2294 int error; 2295 2296 /* 2297 * Grant permission if the caller is the owner of the file, or 2298 * the super-user, or has ACL_WRITE_ATTRIBUTES permission on 2299 * on the file. If the time pointer is null, then write 2300 * permission on the file is also sufficient. 2301 * 2302 * From NFSv4.1, draft 21, 6.2.1.3.1, Discussion of Mask Attributes: 2303 * A user having ACL_WRITE_DATA or ACL_WRITE_ATTRIBUTES 2304 * will be allowed to set the times [..] to the current 2305 * server time. 2306 */ 2307 error = VOP_ACCESSX(vp, VWRITE_ATTRIBUTES, cred, td); 2308 if (error != 0 && (vap->va_vaflags & VA_UTIMES_NULL) != 0) 2309 error = VOP_ACCESS(vp, VWRITE, cred, td); 2310 return (error); 2311 } 2312 2313 int 2314 vn_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 2315 { 2316 struct vnode *vp; 2317 int error; 2318 2319 if (fp->f_type == DTYPE_FIFO) 2320 kif->kf_type = KF_TYPE_FIFO; 2321 else 2322 kif->kf_type = KF_TYPE_VNODE; 2323 vp = fp->f_vnode; 2324 vref(vp); 2325 FILEDESC_SUNLOCK(fdp); 2326 error = vn_fill_kinfo_vnode(vp, kif); 2327 vrele(vp); 2328 FILEDESC_SLOCK(fdp); 2329 return (error); 2330 } 2331 2332 static inline void 2333 vn_fill_junk(struct kinfo_file *kif) 2334 { 2335 size_t len, olen; 2336 2337 /* 2338 * Simulate vn_fullpath returning changing values for a given 2339 * vp during e.g. coredump. 2340 */ 2341 len = (arc4random() % (sizeof(kif->kf_path) - 2)) + 1; 2342 olen = strlen(kif->kf_path); 2343 if (len < olen) 2344 strcpy(&kif->kf_path[len - 1], "$"); 2345 else 2346 for (; olen < len; olen++) 2347 strcpy(&kif->kf_path[olen], "A"); 2348 } 2349 2350 int 2351 vn_fill_kinfo_vnode(struct vnode *vp, struct kinfo_file *kif) 2352 { 2353 struct vattr va; 2354 char *fullpath, *freepath; 2355 int error; 2356 2357 kif->kf_vnode_type = vntype_to_kinfo(vp->v_type); 2358 freepath = NULL; 2359 fullpath = "-"; 2360 error = vn_fullpath(curthread, vp, &fullpath, &freepath); 2361 if (error == 0) { 2362 strlcpy(kif->kf_path, fullpath, sizeof(kif->kf_path)); 2363 } 2364 if (freepath != NULL) 2365 free(freepath, M_TEMP); 2366 2367 KFAIL_POINT_CODE(DEBUG_FP, fill_kinfo_vnode__random_path, 2368 vn_fill_junk(kif); 2369 ); 2370 2371 /* 2372 * Retrieve vnode attributes. 2373 */ 2374 va.va_fsid = VNOVAL; 2375 va.va_rdev = NODEV; 2376 vn_lock(vp, LK_SHARED | LK_RETRY); 2377 error = VOP_GETATTR(vp, &va, curthread->td_ucred); 2378 VOP_UNLOCK(vp, 0); 2379 if (error != 0) 2380 return (error); 2381 if (va.va_fsid != VNOVAL) 2382 kif->kf_un.kf_file.kf_file_fsid = va.va_fsid; 2383 else 2384 kif->kf_un.kf_file.kf_file_fsid = 2385 vp->v_mount->mnt_stat.f_fsid.val[0]; 2386 kif->kf_un.kf_file.kf_file_fileid = va.va_fileid; 2387 kif->kf_un.kf_file.kf_file_mode = MAKEIMODE(va.va_type, va.va_mode); 2388 kif->kf_un.kf_file.kf_file_size = va.va_size; 2389 kif->kf_un.kf_file.kf_file_rdev = va.va_rdev; 2390 return (0); 2391 } 2392 2393 int 2394 vn_mmap(struct file *fp, vm_map_t map, vm_offset_t *addr, vm_size_t size, 2395 vm_prot_t prot, vm_prot_t cap_maxprot, int flags, vm_ooffset_t foff, 2396 struct thread *td) 2397 { 2398 #ifdef HWPMC_HOOKS 2399 struct pmckern_map_in pkm; 2400 #endif 2401 struct mount *mp; 2402 struct vnode *vp; 2403 vm_object_t object; 2404 vm_prot_t maxprot; 2405 boolean_t writecounted; 2406 int error; 2407 2408 #if defined(COMPAT_FREEBSD7) || defined(COMPAT_FREEBSD6) || \ 2409 defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4) 2410 /* 2411 * POSIX shared-memory objects are defined to have 2412 * kernel persistence, and are not defined to support 2413 * read(2)/write(2) -- or even open(2). Thus, we can 2414 * use MAP_ASYNC to trade on-disk coherence for speed. 2415 * The shm_open(3) library routine turns on the FPOSIXSHM 2416 * flag to request this behavior. 2417 */ 2418 if ((fp->f_flag & FPOSIXSHM) != 0) 2419 flags |= MAP_NOSYNC; 2420 #endif 2421 vp = fp->f_vnode; 2422 2423 /* 2424 * Ensure that file and memory protections are 2425 * compatible. Note that we only worry about 2426 * writability if mapping is shared; in this case, 2427 * current and max prot are dictated by the open file. 2428 * XXX use the vnode instead? Problem is: what 2429 * credentials do we use for determination? What if 2430 * proc does a setuid? 2431 */ 2432 mp = vp->v_mount; 2433 if (mp != NULL && (mp->mnt_flag & MNT_NOEXEC) != 0) { 2434 maxprot = VM_PROT_NONE; 2435 if ((prot & VM_PROT_EXECUTE) != 0) 2436 return (EACCES); 2437 } else 2438 maxprot = VM_PROT_EXECUTE; 2439 if ((fp->f_flag & FREAD) != 0) 2440 maxprot |= VM_PROT_READ; 2441 else if ((prot & VM_PROT_READ) != 0) 2442 return (EACCES); 2443 2444 /* 2445 * If we are sharing potential changes via MAP_SHARED and we 2446 * are trying to get write permission although we opened it 2447 * without asking for it, bail out. 2448 */ 2449 if ((flags & MAP_SHARED) != 0) { 2450 if ((fp->f_flag & FWRITE) != 0) 2451 maxprot |= VM_PROT_WRITE; 2452 else if ((prot & VM_PROT_WRITE) != 0) 2453 return (EACCES); 2454 } else { 2455 maxprot |= VM_PROT_WRITE; 2456 cap_maxprot |= VM_PROT_WRITE; 2457 } 2458 maxprot &= cap_maxprot; 2459 2460 /* 2461 * For regular files and shared memory, POSIX requires that 2462 * the value of foff be a legitimate offset within the data 2463 * object. In particular, negative offsets are invalid. 2464 * Blocking negative offsets and overflows here avoids 2465 * possible wraparound or user-level access into reserved 2466 * ranges of the data object later. In contrast, POSIX does 2467 * not dictate how offsets are used by device drivers, so in 2468 * the case of a device mapping a negative offset is passed 2469 * on. 2470 */ 2471 if ( 2472 #ifdef _LP64 2473 size > OFF_MAX || 2474 #endif 2475 foff < 0 || foff > OFF_MAX - size) 2476 return (EINVAL); 2477 2478 writecounted = FALSE; 2479 error = vm_mmap_vnode(td, size, prot, &maxprot, &flags, vp, 2480 &foff, &object, &writecounted); 2481 if (error != 0) 2482 return (error); 2483 error = vm_mmap_object(map, addr, size, prot, maxprot, flags, object, 2484 foff, writecounted, td); 2485 if (error != 0) { 2486 /* 2487 * If this mapping was accounted for in the vnode's 2488 * writecount, then undo that now. 2489 */ 2490 if (writecounted) 2491 vnode_pager_release_writecount(object, 0, size); 2492 vm_object_deallocate(object); 2493 } 2494 #ifdef HWPMC_HOOKS 2495 /* Inform hwpmc(4) if an executable is being mapped. */ 2496 if (PMC_HOOK_INSTALLED(PMC_FN_MMAP)) { 2497 if ((prot & VM_PROT_EXECUTE) != 0 && error == 0) { 2498 pkm.pm_file = vp; 2499 pkm.pm_address = (uintptr_t) *addr; 2500 PMC_CALL_HOOK(td, PMC_FN_MMAP, (void *) &pkm); 2501 } 2502 } 2503 #endif 2504 return (error); 2505 } 2506