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