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 <sys/param.h> 47 #include <sys/systm.h> 48 #include <sys/disk.h> 49 #include <sys/fcntl.h> 50 #include <sys/file.h> 51 #include <sys/kdb.h> 52 #include <sys/stat.h> 53 #include <sys/priv.h> 54 #include <sys/proc.h> 55 #include <sys/limits.h> 56 #include <sys/lock.h> 57 #include <sys/mman.h> 58 #include <sys/mount.h> 59 #include <sys/mutex.h> 60 #include <sys/namei.h> 61 #include <sys/vnode.h> 62 #include <sys/bio.h> 63 #include <sys/buf.h> 64 #include <sys/filio.h> 65 #include <sys/resourcevar.h> 66 #include <sys/rwlock.h> 67 #include <sys/sx.h> 68 #include <sys/sysctl.h> 69 #include <sys/ttycom.h> 70 #include <sys/conf.h> 71 #include <sys/syslog.h> 72 #include <sys/unistd.h> 73 #include <sys/user.h> 74 75 #include <security/audit/audit.h> 76 #include <security/mac/mac_framework.h> 77 78 #include <vm/vm.h> 79 #include <vm/vm_extern.h> 80 #include <vm/pmap.h> 81 #include <vm/vm_map.h> 82 #include <vm/vm_object.h> 83 #include <vm/vm_page.h> 84 #include <vm/vnode_pager.h> 85 86 static fo_rdwr_t vn_read; 87 static fo_rdwr_t vn_write; 88 static fo_rdwr_t vn_io_fault; 89 static fo_truncate_t vn_truncate; 90 static fo_ioctl_t vn_ioctl; 91 static fo_poll_t vn_poll; 92 static fo_kqfilter_t vn_kqfilter; 93 static fo_stat_t vn_statfile; 94 static fo_close_t vn_closefile; 95 static fo_mmap_t vn_mmap; 96 97 struct fileops vnops = { 98 .fo_read = vn_io_fault, 99 .fo_write = vn_io_fault, 100 .fo_truncate = vn_truncate, 101 .fo_ioctl = vn_ioctl, 102 .fo_poll = vn_poll, 103 .fo_kqfilter = vn_kqfilter, 104 .fo_stat = vn_statfile, 105 .fo_close = vn_closefile, 106 .fo_chmod = vn_chmod, 107 .fo_chown = vn_chown, 108 .fo_sendfile = vn_sendfile, 109 .fo_seek = vn_seek, 110 .fo_fill_kinfo = vn_fill_kinfo, 111 .fo_mmap = vn_mmap, 112 .fo_flags = DFLAG_PASSABLE | DFLAG_SEEKABLE 113 }; 114 115 static const int io_hold_cnt = 16; 116 static int vn_io_fault_enable = 1; 117 SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_enable, CTLFLAG_RW, 118 &vn_io_fault_enable, 0, "Enable vn_io_fault lock avoidance"); 119 static u_long vn_io_faults_cnt; 120 SYSCTL_ULONG(_debug, OID_AUTO, vn_io_faults, CTLFLAG_RD, 121 &vn_io_faults_cnt, 0, "Count of vn_io_fault lock avoidance triggers"); 122 123 /* 124 * Returns true if vn_io_fault mode of handling the i/o request should 125 * be used. 126 */ 127 static bool 128 do_vn_io_fault(struct vnode *vp, struct uio *uio) 129 { 130 struct mount *mp; 131 132 return (uio->uio_segflg == UIO_USERSPACE && vp->v_type == VREG && 133 (mp = vp->v_mount) != NULL && 134 (mp->mnt_kern_flag & MNTK_NO_IOPF) != 0 && vn_io_fault_enable); 135 } 136 137 /* 138 * Structure used to pass arguments to vn_io_fault1(), to do either 139 * file- or vnode-based I/O calls. 140 */ 141 struct vn_io_fault_args { 142 enum { 143 VN_IO_FAULT_FOP, 144 VN_IO_FAULT_VOP 145 } kind; 146 struct ucred *cred; 147 int flags; 148 union { 149 struct fop_args_tag { 150 struct file *fp; 151 fo_rdwr_t *doio; 152 } fop_args; 153 struct vop_args_tag { 154 struct vnode *vp; 155 } vop_args; 156 } args; 157 }; 158 159 static int vn_io_fault1(struct vnode *vp, struct uio *uio, 160 struct vn_io_fault_args *args, struct thread *td); 161 162 int 163 vn_open(ndp, flagp, cmode, fp) 164 struct nameidata *ndp; 165 int *flagp, cmode; 166 struct file *fp; 167 { 168 struct thread *td = ndp->ni_cnd.cn_thread; 169 170 return (vn_open_cred(ndp, flagp, cmode, 0, td->td_ucred, fp)); 171 } 172 173 /* 174 * Common code for vnode open operations via a name lookup. 175 * Lookup the vnode and invoke VOP_CREATE if needed. 176 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine. 177 * 178 * Note that this does NOT free nameidata for the successful case, 179 * due to the NDINIT being done elsewhere. 180 */ 181 int 182 vn_open_cred(struct nameidata *ndp, int *flagp, int cmode, u_int vn_open_flags, 183 struct ucred *cred, struct file *fp) 184 { 185 struct vnode *vp; 186 struct mount *mp; 187 struct thread *td = ndp->ni_cnd.cn_thread; 188 struct vattr vat; 189 struct vattr *vap = &vat; 190 int fmode, error; 191 192 restart: 193 fmode = *flagp; 194 if (fmode & O_CREAT) { 195 ndp->ni_cnd.cn_nameiop = CREATE; 196 /* 197 * Set NOCACHE to avoid flushing the cache when 198 * rolling in many files at once. 199 */ 200 ndp->ni_cnd.cn_flags = ISOPEN | LOCKPARENT | LOCKLEAF | NOCACHE; 201 if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0) 202 ndp->ni_cnd.cn_flags |= FOLLOW; 203 if (!(vn_open_flags & VN_OPEN_NOAUDIT)) 204 ndp->ni_cnd.cn_flags |= AUDITVNODE1; 205 if (vn_open_flags & VN_OPEN_NOCAPCHECK) 206 ndp->ni_cnd.cn_flags |= NOCAPCHECK; 207 bwillwrite(); 208 if ((error = namei(ndp)) != 0) 209 return (error); 210 if (ndp->ni_vp == NULL) { 211 VATTR_NULL(vap); 212 vap->va_type = VREG; 213 vap->va_mode = cmode; 214 if (fmode & O_EXCL) 215 vap->va_vaflags |= VA_EXCLUSIVE; 216 if (vn_start_write(ndp->ni_dvp, &mp, V_NOWAIT) != 0) { 217 NDFREE(ndp, NDF_ONLY_PNBUF); 218 vput(ndp->ni_dvp); 219 if ((error = vn_start_write(NULL, &mp, 220 V_XSLEEP | PCATCH)) != 0) 221 return (error); 222 goto restart; 223 } 224 if ((vn_open_flags & VN_OPEN_NAMECACHE) != 0) 225 ndp->ni_cnd.cn_flags |= MAKEENTRY; 226 #ifdef MAC 227 error = mac_vnode_check_create(cred, ndp->ni_dvp, 228 &ndp->ni_cnd, vap); 229 if (error == 0) 230 #endif 231 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp, 232 &ndp->ni_cnd, vap); 233 vput(ndp->ni_dvp); 234 vn_finished_write(mp); 235 if (error) { 236 NDFREE(ndp, NDF_ONLY_PNBUF); 237 return (error); 238 } 239 fmode &= ~O_TRUNC; 240 vp = ndp->ni_vp; 241 } else { 242 if (ndp->ni_dvp == ndp->ni_vp) 243 vrele(ndp->ni_dvp); 244 else 245 vput(ndp->ni_dvp); 246 ndp->ni_dvp = NULL; 247 vp = ndp->ni_vp; 248 if (fmode & O_EXCL) { 249 error = EEXIST; 250 goto bad; 251 } 252 fmode &= ~O_CREAT; 253 } 254 } else { 255 ndp->ni_cnd.cn_nameiop = LOOKUP; 256 ndp->ni_cnd.cn_flags = ISOPEN | 257 ((fmode & O_NOFOLLOW) ? NOFOLLOW : FOLLOW) | LOCKLEAF; 258 if (!(fmode & FWRITE)) 259 ndp->ni_cnd.cn_flags |= LOCKSHARED; 260 if (!(vn_open_flags & VN_OPEN_NOAUDIT)) 261 ndp->ni_cnd.cn_flags |= AUDITVNODE1; 262 if (vn_open_flags & VN_OPEN_NOCAPCHECK) 263 ndp->ni_cnd.cn_flags |= NOCAPCHECK; 264 if ((error = namei(ndp)) != 0) 265 return (error); 266 vp = ndp->ni_vp; 267 } 268 error = vn_open_vnode(vp, fmode, cred, td, fp); 269 if (error) 270 goto bad; 271 *flagp = fmode; 272 return (0); 273 bad: 274 NDFREE(ndp, NDF_ONLY_PNBUF); 275 vput(vp); 276 *flagp = fmode; 277 ndp->ni_vp = NULL; 278 return (error); 279 } 280 281 /* 282 * Common code for vnode open operations once a vnode is located. 283 * Check permissions, and call the VOP_OPEN routine. 284 */ 285 int 286 vn_open_vnode(struct vnode *vp, int fmode, struct ucred *cred, 287 struct thread *td, struct file *fp) 288 { 289 struct mount *mp; 290 accmode_t accmode; 291 struct flock lf; 292 int error, have_flock, lock_flags, type; 293 294 if (vp->v_type == VLNK) 295 return (EMLINK); 296 if (vp->v_type == VSOCK) 297 return (EOPNOTSUPP); 298 if (vp->v_type != VDIR && fmode & O_DIRECTORY) 299 return (ENOTDIR); 300 accmode = 0; 301 if (fmode & (FWRITE | O_TRUNC)) { 302 if (vp->v_type == VDIR) 303 return (EISDIR); 304 accmode |= VWRITE; 305 } 306 if (fmode & FREAD) 307 accmode |= VREAD; 308 if (fmode & FEXEC) 309 accmode |= VEXEC; 310 if ((fmode & O_APPEND) && (fmode & FWRITE)) 311 accmode |= VAPPEND; 312 #ifdef MAC 313 if (fmode & O_CREAT) 314 accmode |= VCREAT; 315 if (fmode & O_VERIFY) 316 accmode |= VVERIFY; 317 error = mac_vnode_check_open(cred, vp, accmode); 318 if (error) 319 return (error); 320 321 accmode &= ~(VCREAT | VVERIFY); 322 #endif 323 if ((fmode & O_CREAT) == 0) { 324 if (accmode & VWRITE) { 325 error = vn_writechk(vp); 326 if (error) 327 return (error); 328 } 329 if (accmode) { 330 error = VOP_ACCESS(vp, accmode, cred, td); 331 if (error) 332 return (error); 333 } 334 } 335 if (vp->v_type == VFIFO && VOP_ISLOCKED(vp) != LK_EXCLUSIVE) 336 vn_lock(vp, LK_UPGRADE | LK_RETRY); 337 if ((error = VOP_OPEN(vp, fmode, cred, td, fp)) != 0) 338 return (error); 339 340 if (fmode & (O_EXLOCK | O_SHLOCK)) { 341 KASSERT(fp != NULL, ("open with flock requires fp")); 342 lock_flags = VOP_ISLOCKED(vp); 343 VOP_UNLOCK(vp, 0); 344 lf.l_whence = SEEK_SET; 345 lf.l_start = 0; 346 lf.l_len = 0; 347 if (fmode & O_EXLOCK) 348 lf.l_type = F_WRLCK; 349 else 350 lf.l_type = F_RDLCK; 351 type = F_FLOCK; 352 if ((fmode & FNONBLOCK) == 0) 353 type |= F_WAIT; 354 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, type); 355 have_flock = (error == 0); 356 vn_lock(vp, lock_flags | LK_RETRY); 357 if (error == 0 && vp->v_iflag & VI_DOOMED) 358 error = ENOENT; 359 /* 360 * Another thread might have used this vnode as an 361 * executable while the vnode lock was dropped. 362 * Ensure the vnode is still able to be opened for 363 * writing after the lock has been obtained. 364 */ 365 if (error == 0 && accmode & VWRITE) 366 error = vn_writechk(vp); 367 if (error) { 368 VOP_UNLOCK(vp, 0); 369 if (have_flock) { 370 lf.l_whence = SEEK_SET; 371 lf.l_start = 0; 372 lf.l_len = 0; 373 lf.l_type = F_UNLCK; 374 (void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, 375 F_FLOCK); 376 } 377 vn_start_write(vp, &mp, V_WAIT); 378 vn_lock(vp, lock_flags | LK_RETRY); 379 (void)VOP_CLOSE(vp, fmode, cred, td); 380 vn_finished_write(mp); 381 /* Prevent second close from fdrop()->vn_close(). */ 382 if (fp != NULL) 383 fp->f_ops= &badfileops; 384 return (error); 385 } 386 fp->f_flag |= FHASLOCK; 387 } 388 if (fmode & FWRITE) { 389 VOP_ADD_WRITECOUNT(vp, 1); 390 CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d", 391 __func__, vp, vp->v_writecount); 392 } 393 ASSERT_VOP_LOCKED(vp, "vn_open_vnode"); 394 return (0); 395 } 396 397 /* 398 * Check for write permissions on the specified vnode. 399 * Prototype text segments cannot be written. 400 */ 401 int 402 vn_writechk(vp) 403 register struct vnode *vp; 404 { 405 406 ASSERT_VOP_LOCKED(vp, "vn_writechk"); 407 /* 408 * If there's shared text associated with 409 * the vnode, try to free it up once. If 410 * we fail, we can't allow writing. 411 */ 412 if (VOP_IS_TEXT(vp)) 413 return (ETXTBSY); 414 415 return (0); 416 } 417 418 /* 419 * Vnode close call 420 */ 421 int 422 vn_close(vp, flags, file_cred, td) 423 register struct vnode *vp; 424 int flags; 425 struct ucred *file_cred; 426 struct thread *td; 427 { 428 struct mount *mp; 429 int error, lock_flags; 430 431 if (vp->v_type != VFIFO && (flags & FWRITE) == 0 && 432 MNT_EXTENDED_SHARED(vp->v_mount)) 433 lock_flags = LK_SHARED; 434 else 435 lock_flags = LK_EXCLUSIVE; 436 437 vn_start_write(vp, &mp, V_WAIT); 438 vn_lock(vp, lock_flags | LK_RETRY); 439 if (flags & FWRITE) { 440 VNASSERT(vp->v_writecount > 0, vp, 441 ("vn_close: negative writecount")); 442 VOP_ADD_WRITECOUNT(vp, -1); 443 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d", 444 __func__, vp, vp->v_writecount); 445 } 446 error = VOP_CLOSE(vp, flags, file_cred, td); 447 vput(vp); 448 vn_finished_write(mp); 449 return (error); 450 } 451 452 /* 453 * Heuristic to detect sequential operation. 454 */ 455 static int 456 sequential_heuristic(struct uio *uio, struct file *fp) 457 { 458 459 ASSERT_VOP_LOCKED(fp->f_vnode, __func__); 460 if (fp->f_flag & FRDAHEAD) 461 return (fp->f_seqcount << IO_SEQSHIFT); 462 463 /* 464 * Offset 0 is handled specially. open() sets f_seqcount to 1 so 465 * that the first I/O is normally considered to be slightly 466 * sequential. Seeking to offset 0 doesn't change sequentiality 467 * unless previous seeks have reduced f_seqcount to 0, in which 468 * case offset 0 is not special. 469 */ 470 if ((uio->uio_offset == 0 && fp->f_seqcount > 0) || 471 uio->uio_offset == fp->f_nextoff) { 472 /* 473 * f_seqcount is in units of fixed-size blocks so that it 474 * depends mainly on the amount of sequential I/O and not 475 * much on the number of sequential I/O's. The fixed size 476 * of 16384 is hard-coded here since it is (not quite) just 477 * a magic size that works well here. This size is more 478 * closely related to the best I/O size for real disks than 479 * to any block size used by software. 480 */ 481 fp->f_seqcount += howmany(uio->uio_resid, 16384); 482 if (fp->f_seqcount > IO_SEQMAX) 483 fp->f_seqcount = IO_SEQMAX; 484 return (fp->f_seqcount << IO_SEQSHIFT); 485 } 486 487 /* Not sequential. Quickly draw-down sequentiality. */ 488 if (fp->f_seqcount > 1) 489 fp->f_seqcount = 1; 490 else 491 fp->f_seqcount = 0; 492 return (0); 493 } 494 495 /* 496 * Package up an I/O request on a vnode into a uio and do it. 497 */ 498 int 499 vn_rdwr(enum uio_rw rw, struct vnode *vp, void *base, int len, off_t offset, 500 enum uio_seg segflg, int ioflg, struct ucred *active_cred, 501 struct ucred *file_cred, ssize_t *aresid, struct thread *td) 502 { 503 struct uio auio; 504 struct iovec aiov; 505 struct mount *mp; 506 struct ucred *cred; 507 void *rl_cookie; 508 struct vn_io_fault_args args; 509 int error, lock_flags; 510 511 auio.uio_iov = &aiov; 512 auio.uio_iovcnt = 1; 513 aiov.iov_base = base; 514 aiov.iov_len = len; 515 auio.uio_resid = len; 516 auio.uio_offset = offset; 517 auio.uio_segflg = segflg; 518 auio.uio_rw = rw; 519 auio.uio_td = td; 520 error = 0; 521 522 if ((ioflg & IO_NODELOCKED) == 0) { 523 if ((ioflg & IO_RANGELOCKED) == 0) { 524 if (rw == UIO_READ) { 525 rl_cookie = vn_rangelock_rlock(vp, offset, 526 offset + len); 527 } else { 528 rl_cookie = vn_rangelock_wlock(vp, offset, 529 offset + len); 530 } 531 } else 532 rl_cookie = NULL; 533 mp = NULL; 534 if (rw == UIO_WRITE) { 535 if (vp->v_type != VCHR && 536 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) 537 != 0) 538 goto out; 539 if (MNT_SHARED_WRITES(mp) || 540 ((mp == NULL) && MNT_SHARED_WRITES(vp->v_mount))) 541 lock_flags = LK_SHARED; 542 else 543 lock_flags = LK_EXCLUSIVE; 544 } else 545 lock_flags = LK_SHARED; 546 vn_lock(vp, lock_flags | LK_RETRY); 547 } else 548 rl_cookie = NULL; 549 550 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 551 #ifdef MAC 552 if ((ioflg & IO_NOMACCHECK) == 0) { 553 if (rw == UIO_READ) 554 error = mac_vnode_check_read(active_cred, file_cred, 555 vp); 556 else 557 error = mac_vnode_check_write(active_cred, file_cred, 558 vp); 559 } 560 #endif 561 if (error == 0) { 562 if (file_cred != NULL) 563 cred = file_cred; 564 else 565 cred = active_cred; 566 if (do_vn_io_fault(vp, &auio)) { 567 args.kind = VN_IO_FAULT_VOP; 568 args.cred = cred; 569 args.flags = ioflg; 570 args.args.vop_args.vp = vp; 571 error = vn_io_fault1(vp, &auio, &args, td); 572 } else if (rw == UIO_READ) { 573 error = VOP_READ(vp, &auio, ioflg, cred); 574 } else /* if (rw == UIO_WRITE) */ { 575 error = VOP_WRITE(vp, &auio, ioflg, cred); 576 } 577 } 578 if (aresid) 579 *aresid = auio.uio_resid; 580 else 581 if (auio.uio_resid && error == 0) 582 error = EIO; 583 if ((ioflg & IO_NODELOCKED) == 0) { 584 VOP_UNLOCK(vp, 0); 585 if (mp != NULL) 586 vn_finished_write(mp); 587 } 588 out: 589 if (rl_cookie != NULL) 590 vn_rangelock_unlock(vp, rl_cookie); 591 return (error); 592 } 593 594 /* 595 * Package up an I/O request on a vnode into a uio and do it. The I/O 596 * request is split up into smaller chunks and we try to avoid saturating 597 * the buffer cache while potentially holding a vnode locked, so we 598 * check bwillwrite() before calling vn_rdwr(). We also call kern_yield() 599 * to give other processes a chance to lock the vnode (either other processes 600 * core'ing the same binary, or unrelated processes scanning the directory). 601 */ 602 int 603 vn_rdwr_inchunks(rw, vp, base, len, offset, segflg, ioflg, active_cred, 604 file_cred, aresid, td) 605 enum uio_rw rw; 606 struct vnode *vp; 607 void *base; 608 size_t len; 609 off_t offset; 610 enum uio_seg segflg; 611 int ioflg; 612 struct ucred *active_cred; 613 struct ucred *file_cred; 614 size_t *aresid; 615 struct thread *td; 616 { 617 int error = 0; 618 ssize_t iaresid; 619 620 do { 621 int chunk; 622 623 /* 624 * Force `offset' to a multiple of MAXBSIZE except possibly 625 * for the first chunk, so that filesystems only need to 626 * write full blocks except possibly for the first and last 627 * chunks. 628 */ 629 chunk = MAXBSIZE - (uoff_t)offset % MAXBSIZE; 630 631 if (chunk > len) 632 chunk = len; 633 if (rw != UIO_READ && vp->v_type == VREG) 634 bwillwrite(); 635 iaresid = 0; 636 error = vn_rdwr(rw, vp, base, chunk, offset, segflg, 637 ioflg, active_cred, file_cred, &iaresid, td); 638 len -= chunk; /* aresid calc already includes length */ 639 if (error) 640 break; 641 offset += chunk; 642 base = (char *)base + chunk; 643 kern_yield(PRI_USER); 644 } while (len); 645 if (aresid) 646 *aresid = len + iaresid; 647 return (error); 648 } 649 650 off_t 651 foffset_lock(struct file *fp, int flags) 652 { 653 struct mtx *mtxp; 654 off_t res; 655 656 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed")); 657 658 #if OFF_MAX <= LONG_MAX 659 /* 660 * Caller only wants the current f_offset value. Assume that 661 * the long and shorter integer types reads are atomic. 662 */ 663 if ((flags & FOF_NOLOCK) != 0) 664 return (fp->f_offset); 665 #endif 666 667 /* 668 * According to McKusick the vn lock was protecting f_offset here. 669 * It is now protected by the FOFFSET_LOCKED flag. 670 */ 671 mtxp = mtx_pool_find(mtxpool_sleep, fp); 672 mtx_lock(mtxp); 673 if ((flags & FOF_NOLOCK) == 0) { 674 while (fp->f_vnread_flags & FOFFSET_LOCKED) { 675 fp->f_vnread_flags |= FOFFSET_LOCK_WAITING; 676 msleep(&fp->f_vnread_flags, mtxp, PUSER -1, 677 "vofflock", 0); 678 } 679 fp->f_vnread_flags |= FOFFSET_LOCKED; 680 } 681 res = fp->f_offset; 682 mtx_unlock(mtxp); 683 return (res); 684 } 685 686 void 687 foffset_unlock(struct file *fp, off_t val, int flags) 688 { 689 struct mtx *mtxp; 690 691 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed")); 692 693 #if OFF_MAX <= LONG_MAX 694 if ((flags & FOF_NOLOCK) != 0) { 695 if ((flags & FOF_NOUPDATE) == 0) 696 fp->f_offset = val; 697 if ((flags & FOF_NEXTOFF) != 0) 698 fp->f_nextoff = val; 699 return; 700 } 701 #endif 702 703 mtxp = mtx_pool_find(mtxpool_sleep, fp); 704 mtx_lock(mtxp); 705 if ((flags & FOF_NOUPDATE) == 0) 706 fp->f_offset = val; 707 if ((flags & FOF_NEXTOFF) != 0) 708 fp->f_nextoff = val; 709 if ((flags & FOF_NOLOCK) == 0) { 710 KASSERT((fp->f_vnread_flags & FOFFSET_LOCKED) != 0, 711 ("Lost FOFFSET_LOCKED")); 712 if (fp->f_vnread_flags & FOFFSET_LOCK_WAITING) 713 wakeup(&fp->f_vnread_flags); 714 fp->f_vnread_flags = 0; 715 } 716 mtx_unlock(mtxp); 717 } 718 719 void 720 foffset_lock_uio(struct file *fp, struct uio *uio, int flags) 721 { 722 723 if ((flags & FOF_OFFSET) == 0) 724 uio->uio_offset = foffset_lock(fp, flags); 725 } 726 727 void 728 foffset_unlock_uio(struct file *fp, struct uio *uio, int flags) 729 { 730 731 if ((flags & FOF_OFFSET) == 0) 732 foffset_unlock(fp, uio->uio_offset, flags); 733 } 734 735 static int 736 get_advice(struct file *fp, struct uio *uio) 737 { 738 struct mtx *mtxp; 739 int ret; 740 741 ret = POSIX_FADV_NORMAL; 742 if (fp->f_advice == NULL) 743 return (ret); 744 745 mtxp = mtx_pool_find(mtxpool_sleep, fp); 746 mtx_lock(mtxp); 747 if (uio->uio_offset >= fp->f_advice->fa_start && 748 uio->uio_offset + uio->uio_resid <= fp->f_advice->fa_end) 749 ret = fp->f_advice->fa_advice; 750 mtx_unlock(mtxp); 751 return (ret); 752 } 753 754 /* 755 * File table vnode read routine. 756 */ 757 static int 758 vn_read(fp, uio, active_cred, flags, td) 759 struct file *fp; 760 struct uio *uio; 761 struct ucred *active_cred; 762 int flags; 763 struct thread *td; 764 { 765 struct vnode *vp; 766 struct mtx *mtxp; 767 int error, ioflag; 768 int advice; 769 off_t offset, start, end; 770 771 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", 772 uio->uio_td, td)); 773 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET")); 774 vp = fp->f_vnode; 775 ioflag = 0; 776 if (fp->f_flag & FNONBLOCK) 777 ioflag |= IO_NDELAY; 778 if (fp->f_flag & O_DIRECT) 779 ioflag |= IO_DIRECT; 780 advice = get_advice(fp, uio); 781 vn_lock(vp, LK_SHARED | LK_RETRY); 782 783 switch (advice) { 784 case POSIX_FADV_NORMAL: 785 case POSIX_FADV_SEQUENTIAL: 786 case POSIX_FADV_NOREUSE: 787 ioflag |= sequential_heuristic(uio, fp); 788 break; 789 case POSIX_FADV_RANDOM: 790 /* Disable read-ahead for random I/O. */ 791 break; 792 } 793 offset = uio->uio_offset; 794 795 #ifdef MAC 796 error = mac_vnode_check_read(active_cred, fp->f_cred, vp); 797 if (error == 0) 798 #endif 799 error = VOP_READ(vp, uio, ioflag, fp->f_cred); 800 fp->f_nextoff = uio->uio_offset; 801 VOP_UNLOCK(vp, 0); 802 if (error == 0 && advice == POSIX_FADV_NOREUSE && 803 offset != uio->uio_offset) { 804 /* 805 * Use POSIX_FADV_DONTNEED to flush clean pages and 806 * buffers for the backing file after a 807 * POSIX_FADV_NOREUSE read(2). To optimize the common 808 * case of using POSIX_FADV_NOREUSE with sequential 809 * access, track the previous implicit DONTNEED 810 * request and grow this request to include the 811 * current read(2) in addition to the previous 812 * DONTNEED. With purely sequential access this will 813 * cause the DONTNEED requests to continously grow to 814 * cover all of the previously read regions of the 815 * file. This allows filesystem blocks that are 816 * accessed by multiple calls to read(2) to be flushed 817 * once the last read(2) finishes. 818 */ 819 start = offset; 820 end = uio->uio_offset - 1; 821 mtxp = mtx_pool_find(mtxpool_sleep, fp); 822 mtx_lock(mtxp); 823 if (fp->f_advice != NULL && 824 fp->f_advice->fa_advice == POSIX_FADV_NOREUSE) { 825 if (start != 0 && fp->f_advice->fa_prevend + 1 == start) 826 start = fp->f_advice->fa_prevstart; 827 else if (fp->f_advice->fa_prevstart != 0 && 828 fp->f_advice->fa_prevstart == end + 1) 829 end = fp->f_advice->fa_prevend; 830 fp->f_advice->fa_prevstart = start; 831 fp->f_advice->fa_prevend = end; 832 } 833 mtx_unlock(mtxp); 834 error = VOP_ADVISE(vp, start, end, POSIX_FADV_DONTNEED); 835 } 836 return (error); 837 } 838 839 /* 840 * File table vnode write routine. 841 */ 842 static int 843 vn_write(fp, uio, active_cred, flags, td) 844 struct file *fp; 845 struct uio *uio; 846 struct ucred *active_cred; 847 int flags; 848 struct thread *td; 849 { 850 struct vnode *vp; 851 struct mount *mp; 852 struct mtx *mtxp; 853 int error, ioflag, lock_flags; 854 int advice; 855 off_t offset, start, end; 856 857 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", 858 uio->uio_td, td)); 859 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET")); 860 vp = fp->f_vnode; 861 if (vp->v_type == VREG) 862 bwillwrite(); 863 ioflag = IO_UNIT; 864 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 865 ioflag |= IO_APPEND; 866 if (fp->f_flag & FNONBLOCK) 867 ioflag |= IO_NDELAY; 868 if (fp->f_flag & O_DIRECT) 869 ioflag |= IO_DIRECT; 870 if ((fp->f_flag & O_FSYNC) || 871 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS))) 872 ioflag |= IO_SYNC; 873 mp = NULL; 874 if (vp->v_type != VCHR && 875 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0) 876 goto unlock; 877 878 advice = get_advice(fp, uio); 879 880 if (MNT_SHARED_WRITES(mp) || 881 (mp == NULL && MNT_SHARED_WRITES(vp->v_mount))) { 882 lock_flags = LK_SHARED; 883 } else { 884 lock_flags = LK_EXCLUSIVE; 885 } 886 887 vn_lock(vp, lock_flags | LK_RETRY); 888 switch (advice) { 889 case POSIX_FADV_NORMAL: 890 case POSIX_FADV_SEQUENTIAL: 891 case POSIX_FADV_NOREUSE: 892 ioflag |= sequential_heuristic(uio, fp); 893 break; 894 case POSIX_FADV_RANDOM: 895 /* XXX: Is this correct? */ 896 break; 897 } 898 offset = uio->uio_offset; 899 900 #ifdef MAC 901 error = mac_vnode_check_write(active_cred, fp->f_cred, vp); 902 if (error == 0) 903 #endif 904 error = VOP_WRITE(vp, uio, ioflag, fp->f_cred); 905 fp->f_nextoff = uio->uio_offset; 906 VOP_UNLOCK(vp, 0); 907 if (vp->v_type != VCHR) 908 vn_finished_write(mp); 909 if (error == 0 && advice == POSIX_FADV_NOREUSE && 910 offset != uio->uio_offset) { 911 /* 912 * Use POSIX_FADV_DONTNEED to flush clean pages and 913 * buffers for the backing file after a 914 * POSIX_FADV_NOREUSE write(2). To optimize the 915 * common case of using POSIX_FADV_NOREUSE with 916 * sequential access, track the previous implicit 917 * DONTNEED request and grow this request to include 918 * the current write(2) in addition to the previous 919 * DONTNEED. With purely sequential access this will 920 * cause the DONTNEED requests to continously grow to 921 * cover all of the previously written regions of the 922 * file. 923 * 924 * Note that the blocks just written are almost 925 * certainly still dirty, so this only works when 926 * VOP_ADVISE() calls from subsequent writes push out 927 * the data written by this write(2) once the backing 928 * buffers are clean. However, as compared to forcing 929 * IO_DIRECT, this gives much saner behavior. Write 930 * clustering is still allowed, and clean pages are 931 * merely moved to the cache page queue rather than 932 * outright thrown away. This means a subsequent 933 * read(2) can still avoid hitting the disk if the 934 * pages have not been reclaimed. 935 * 936 * This does make POSIX_FADV_NOREUSE largely useless 937 * with non-sequential access. However, sequential 938 * access is the more common use case and the flag is 939 * merely advisory. 940 */ 941 start = offset; 942 end = uio->uio_offset - 1; 943 mtxp = mtx_pool_find(mtxpool_sleep, fp); 944 mtx_lock(mtxp); 945 if (fp->f_advice != NULL && 946 fp->f_advice->fa_advice == POSIX_FADV_NOREUSE) { 947 if (start != 0 && fp->f_advice->fa_prevend + 1 == start) 948 start = fp->f_advice->fa_prevstart; 949 else if (fp->f_advice->fa_prevstart != 0 && 950 fp->f_advice->fa_prevstart == end + 1) 951 end = fp->f_advice->fa_prevend; 952 fp->f_advice->fa_prevstart = start; 953 fp->f_advice->fa_prevend = end; 954 } 955 mtx_unlock(mtxp); 956 error = VOP_ADVISE(vp, start, end, POSIX_FADV_DONTNEED); 957 } 958 959 unlock: 960 return (error); 961 } 962 963 /* 964 * The vn_io_fault() is a wrapper around vn_read() and vn_write() to 965 * prevent the following deadlock: 966 * 967 * Assume that the thread A reads from the vnode vp1 into userspace 968 * buffer buf1 backed by the pages of vnode vp2. If a page in buf1 is 969 * currently not resident, then system ends up with the call chain 970 * vn_read() -> VOP_READ(vp1) -> uiomove() -> [Page Fault] -> 971 * vm_fault(buf1) -> vnode_pager_getpages(vp2) -> VOP_GETPAGES(vp2) 972 * which establishes lock order vp1->vn_lock, then vp2->vn_lock. 973 * If, at the same time, thread B reads from vnode vp2 into buffer buf2 974 * backed by the pages of vnode vp1, and some page in buf2 is not 975 * resident, we get a reversed order vp2->vn_lock, then vp1->vn_lock. 976 * 977 * To prevent the lock order reversal and deadlock, vn_io_fault() does 978 * not allow page faults to happen during VOP_READ() or VOP_WRITE(). 979 * Instead, it first tries to do the whole range i/o with pagefaults 980 * disabled. If all pages in the i/o buffer are resident and mapped, 981 * VOP will succeed (ignoring the genuine filesystem errors). 982 * Otherwise, we get back EFAULT, and vn_io_fault() falls back to do 983 * i/o in chunks, with all pages in the chunk prefaulted and held 984 * using vm_fault_quick_hold_pages(). 985 * 986 * Filesystems using this deadlock avoidance scheme should use the 987 * array of the held pages from uio, saved in the curthread->td_ma, 988 * instead of doing uiomove(). A helper function 989 * vn_io_fault_uiomove() converts uiomove request into 990 * uiomove_fromphys() over td_ma array. 991 * 992 * Since vnode locks do not cover the whole i/o anymore, rangelocks 993 * make the current i/o request atomic with respect to other i/os and 994 * truncations. 995 */ 996 997 /* 998 * Decode vn_io_fault_args and perform the corresponding i/o. 999 */ 1000 static int 1001 vn_io_fault_doio(struct vn_io_fault_args *args, struct uio *uio, 1002 struct thread *td) 1003 { 1004 1005 switch (args->kind) { 1006 case VN_IO_FAULT_FOP: 1007 return ((args->args.fop_args.doio)(args->args.fop_args.fp, 1008 uio, args->cred, args->flags, td)); 1009 case VN_IO_FAULT_VOP: 1010 if (uio->uio_rw == UIO_READ) { 1011 return (VOP_READ(args->args.vop_args.vp, uio, 1012 args->flags, args->cred)); 1013 } else if (uio->uio_rw == UIO_WRITE) { 1014 return (VOP_WRITE(args->args.vop_args.vp, uio, 1015 args->flags, args->cred)); 1016 } 1017 break; 1018 } 1019 panic("vn_io_fault_doio: unknown kind of io %d %d", args->kind, 1020 uio->uio_rw); 1021 } 1022 1023 /* 1024 * Common code for vn_io_fault(), agnostic to the kind of i/o request. 1025 * Uses vn_io_fault_doio() to make the call to an actual i/o function. 1026 * Used from vn_rdwr() and vn_io_fault(), which encode the i/o request 1027 * into args and call vn_io_fault1() to handle faults during the user 1028 * mode buffer accesses. 1029 */ 1030 static int 1031 vn_io_fault1(struct vnode *vp, struct uio *uio, struct vn_io_fault_args *args, 1032 struct thread *td) 1033 { 1034 vm_page_t ma[io_hold_cnt + 2]; 1035 struct uio *uio_clone, short_uio; 1036 struct iovec short_iovec[1]; 1037 vm_page_t *prev_td_ma; 1038 vm_prot_t prot; 1039 vm_offset_t addr, end; 1040 size_t len, resid; 1041 ssize_t adv; 1042 int error, cnt, save, saveheld, prev_td_ma_cnt; 1043 1044 prot = uio->uio_rw == UIO_READ ? VM_PROT_WRITE : VM_PROT_READ; 1045 1046 /* 1047 * The UFS follows IO_UNIT directive and replays back both 1048 * uio_offset and uio_resid if an error is encountered during the 1049 * operation. But, since the iovec may be already advanced, 1050 * uio is still in an inconsistent state. 1051 * 1052 * Cache a copy of the original uio, which is advanced to the redo 1053 * point using UIO_NOCOPY below. 1054 */ 1055 uio_clone = cloneuio(uio); 1056 resid = uio->uio_resid; 1057 1058 short_uio.uio_segflg = UIO_USERSPACE; 1059 short_uio.uio_rw = uio->uio_rw; 1060 short_uio.uio_td = uio->uio_td; 1061 1062 save = vm_fault_disable_pagefaults(); 1063 error = vn_io_fault_doio(args, uio, td); 1064 if (error != EFAULT) 1065 goto out; 1066 1067 atomic_add_long(&vn_io_faults_cnt, 1); 1068 uio_clone->uio_segflg = UIO_NOCOPY; 1069 uiomove(NULL, resid - uio->uio_resid, uio_clone); 1070 uio_clone->uio_segflg = uio->uio_segflg; 1071 1072 saveheld = curthread_pflags_set(TDP_UIOHELD); 1073 prev_td_ma = td->td_ma; 1074 prev_td_ma_cnt = td->td_ma_cnt; 1075 1076 while (uio_clone->uio_resid != 0) { 1077 len = uio_clone->uio_iov->iov_len; 1078 if (len == 0) { 1079 KASSERT(uio_clone->uio_iovcnt >= 1, 1080 ("iovcnt underflow")); 1081 uio_clone->uio_iov++; 1082 uio_clone->uio_iovcnt--; 1083 continue; 1084 } 1085 if (len > io_hold_cnt * PAGE_SIZE) 1086 len = io_hold_cnt * PAGE_SIZE; 1087 addr = (uintptr_t)uio_clone->uio_iov->iov_base; 1088 end = round_page(addr + len); 1089 if (end < addr) { 1090 error = EFAULT; 1091 break; 1092 } 1093 cnt = atop(end - trunc_page(addr)); 1094 /* 1095 * A perfectly misaligned address and length could cause 1096 * both the start and the end of the chunk to use partial 1097 * page. +2 accounts for such a situation. 1098 */ 1099 cnt = vm_fault_quick_hold_pages(&td->td_proc->p_vmspace->vm_map, 1100 addr, len, prot, ma, io_hold_cnt + 2); 1101 if (cnt == -1) { 1102 error = EFAULT; 1103 break; 1104 } 1105 short_uio.uio_iov = &short_iovec[0]; 1106 short_iovec[0].iov_base = (void *)addr; 1107 short_uio.uio_iovcnt = 1; 1108 short_uio.uio_resid = short_iovec[0].iov_len = len; 1109 short_uio.uio_offset = uio_clone->uio_offset; 1110 td->td_ma = ma; 1111 td->td_ma_cnt = cnt; 1112 1113 error = vn_io_fault_doio(args, &short_uio, td); 1114 vm_page_unhold_pages(ma, cnt); 1115 adv = len - short_uio.uio_resid; 1116 1117 uio_clone->uio_iov->iov_base = 1118 (char *)uio_clone->uio_iov->iov_base + adv; 1119 uio_clone->uio_iov->iov_len -= adv; 1120 uio_clone->uio_resid -= adv; 1121 uio_clone->uio_offset += adv; 1122 1123 uio->uio_resid -= adv; 1124 uio->uio_offset += adv; 1125 1126 if (error != 0 || adv == 0) 1127 break; 1128 } 1129 td->td_ma = prev_td_ma; 1130 td->td_ma_cnt = prev_td_ma_cnt; 1131 curthread_pflags_restore(saveheld); 1132 out: 1133 vm_fault_enable_pagefaults(save); 1134 free(uio_clone, M_IOV); 1135 return (error); 1136 } 1137 1138 static int 1139 vn_io_fault(struct file *fp, struct uio *uio, struct ucred *active_cred, 1140 int flags, struct thread *td) 1141 { 1142 fo_rdwr_t *doio; 1143 struct vnode *vp; 1144 void *rl_cookie; 1145 struct vn_io_fault_args args; 1146 int error; 1147 1148 doio = uio->uio_rw == UIO_READ ? vn_read : vn_write; 1149 vp = fp->f_vnode; 1150 foffset_lock_uio(fp, uio, flags); 1151 if (do_vn_io_fault(vp, uio)) { 1152 args.kind = VN_IO_FAULT_FOP; 1153 args.args.fop_args.fp = fp; 1154 args.args.fop_args.doio = doio; 1155 args.cred = active_cred; 1156 args.flags = flags | FOF_OFFSET; 1157 if (uio->uio_rw == UIO_READ) { 1158 rl_cookie = vn_rangelock_rlock(vp, uio->uio_offset, 1159 uio->uio_offset + uio->uio_resid); 1160 } else if ((fp->f_flag & O_APPEND) != 0 || 1161 (flags & FOF_OFFSET) == 0) { 1162 /* For appenders, punt and lock the whole range. */ 1163 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 1164 } else { 1165 rl_cookie = vn_rangelock_wlock(vp, uio->uio_offset, 1166 uio->uio_offset + uio->uio_resid); 1167 } 1168 error = vn_io_fault1(vp, uio, &args, td); 1169 vn_rangelock_unlock(vp, rl_cookie); 1170 } else { 1171 error = doio(fp, uio, active_cred, flags | FOF_OFFSET, td); 1172 } 1173 foffset_unlock_uio(fp, uio, flags); 1174 return (error); 1175 } 1176 1177 /* 1178 * Helper function to perform the requested uiomove operation using 1179 * the held pages for io->uio_iov[0].iov_base buffer instead of 1180 * copyin/copyout. Access to the pages with uiomove_fromphys() 1181 * instead of iov_base prevents page faults that could occur due to 1182 * pmap_collect() invalidating the mapping created by 1183 * vm_fault_quick_hold_pages(), or pageout daemon, page laundry or 1184 * object cleanup revoking the write access from page mappings. 1185 * 1186 * Filesystems specified MNTK_NO_IOPF shall use vn_io_fault_uiomove() 1187 * instead of plain uiomove(). 1188 */ 1189 int 1190 vn_io_fault_uiomove(char *data, int xfersize, struct uio *uio) 1191 { 1192 struct uio transp_uio; 1193 struct iovec transp_iov[1]; 1194 struct thread *td; 1195 size_t adv; 1196 int error, pgadv; 1197 1198 td = curthread; 1199 if ((td->td_pflags & TDP_UIOHELD) == 0 || 1200 uio->uio_segflg != UIO_USERSPACE) 1201 return (uiomove(data, xfersize, uio)); 1202 1203 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt)); 1204 transp_iov[0].iov_base = data; 1205 transp_uio.uio_iov = &transp_iov[0]; 1206 transp_uio.uio_iovcnt = 1; 1207 if (xfersize > uio->uio_resid) 1208 xfersize = uio->uio_resid; 1209 transp_uio.uio_resid = transp_iov[0].iov_len = xfersize; 1210 transp_uio.uio_offset = 0; 1211 transp_uio.uio_segflg = UIO_SYSSPACE; 1212 /* 1213 * Since transp_iov points to data, and td_ma page array 1214 * corresponds to original uio->uio_iov, we need to invert the 1215 * direction of the i/o operation as passed to 1216 * uiomove_fromphys(). 1217 */ 1218 switch (uio->uio_rw) { 1219 case UIO_WRITE: 1220 transp_uio.uio_rw = UIO_READ; 1221 break; 1222 case UIO_READ: 1223 transp_uio.uio_rw = UIO_WRITE; 1224 break; 1225 } 1226 transp_uio.uio_td = uio->uio_td; 1227 error = uiomove_fromphys(td->td_ma, 1228 ((vm_offset_t)uio->uio_iov->iov_base) & PAGE_MASK, 1229 xfersize, &transp_uio); 1230 adv = xfersize - transp_uio.uio_resid; 1231 pgadv = 1232 (((vm_offset_t)uio->uio_iov->iov_base + adv) >> PAGE_SHIFT) - 1233 (((vm_offset_t)uio->uio_iov->iov_base) >> PAGE_SHIFT); 1234 td->td_ma += pgadv; 1235 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt, 1236 pgadv)); 1237 td->td_ma_cnt -= pgadv; 1238 uio->uio_iov->iov_base = (char *)uio->uio_iov->iov_base + adv; 1239 uio->uio_iov->iov_len -= adv; 1240 uio->uio_resid -= adv; 1241 uio->uio_offset += adv; 1242 return (error); 1243 } 1244 1245 int 1246 vn_io_fault_pgmove(vm_page_t ma[], vm_offset_t offset, int xfersize, 1247 struct uio *uio) 1248 { 1249 struct thread *td; 1250 vm_offset_t iov_base; 1251 int cnt, pgadv; 1252 1253 td = curthread; 1254 if ((td->td_pflags & TDP_UIOHELD) == 0 || 1255 uio->uio_segflg != UIO_USERSPACE) 1256 return (uiomove_fromphys(ma, offset, xfersize, uio)); 1257 1258 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt)); 1259 cnt = xfersize > uio->uio_resid ? uio->uio_resid : xfersize; 1260 iov_base = (vm_offset_t)uio->uio_iov->iov_base; 1261 switch (uio->uio_rw) { 1262 case UIO_WRITE: 1263 pmap_copy_pages(td->td_ma, iov_base & PAGE_MASK, ma, 1264 offset, cnt); 1265 break; 1266 case UIO_READ: 1267 pmap_copy_pages(ma, offset, td->td_ma, iov_base & PAGE_MASK, 1268 cnt); 1269 break; 1270 } 1271 pgadv = ((iov_base + cnt) >> PAGE_SHIFT) - (iov_base >> PAGE_SHIFT); 1272 td->td_ma += pgadv; 1273 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt, 1274 pgadv)); 1275 td->td_ma_cnt -= pgadv; 1276 uio->uio_iov->iov_base = (char *)(iov_base + cnt); 1277 uio->uio_iov->iov_len -= cnt; 1278 uio->uio_resid -= cnt; 1279 uio->uio_offset += cnt; 1280 return (0); 1281 } 1282 1283 1284 /* 1285 * File table truncate routine. 1286 */ 1287 static int 1288 vn_truncate(struct file *fp, off_t length, struct ucred *active_cred, 1289 struct thread *td) 1290 { 1291 struct vattr vattr; 1292 struct mount *mp; 1293 struct vnode *vp; 1294 void *rl_cookie; 1295 int error; 1296 1297 vp = fp->f_vnode; 1298 1299 /* 1300 * Lock the whole range for truncation. Otherwise split i/o 1301 * might happen partly before and partly after the truncation. 1302 */ 1303 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 1304 error = vn_start_write(vp, &mp, V_WAIT | PCATCH); 1305 if (error) 1306 goto out1; 1307 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1308 if (vp->v_type == VDIR) { 1309 error = EISDIR; 1310 goto out; 1311 } 1312 #ifdef MAC 1313 error = mac_vnode_check_write(active_cred, fp->f_cred, vp); 1314 if (error) 1315 goto out; 1316 #endif 1317 error = vn_writechk(vp); 1318 if (error == 0) { 1319 VATTR_NULL(&vattr); 1320 vattr.va_size = length; 1321 error = VOP_SETATTR(vp, &vattr, fp->f_cred); 1322 } 1323 out: 1324 VOP_UNLOCK(vp, 0); 1325 vn_finished_write(mp); 1326 out1: 1327 vn_rangelock_unlock(vp, rl_cookie); 1328 return (error); 1329 } 1330 1331 /* 1332 * File table vnode stat routine. 1333 */ 1334 static int 1335 vn_statfile(fp, sb, active_cred, td) 1336 struct file *fp; 1337 struct stat *sb; 1338 struct ucred *active_cred; 1339 struct thread *td; 1340 { 1341 struct vnode *vp = fp->f_vnode; 1342 int error; 1343 1344 vn_lock(vp, LK_SHARED | LK_RETRY); 1345 error = vn_stat(vp, sb, active_cred, fp->f_cred, td); 1346 VOP_UNLOCK(vp, 0); 1347 1348 return (error); 1349 } 1350 1351 /* 1352 * Stat a vnode; implementation for the stat syscall 1353 */ 1354 int 1355 vn_stat(vp, sb, active_cred, file_cred, td) 1356 struct vnode *vp; 1357 register struct stat *sb; 1358 struct ucred *active_cred; 1359 struct ucred *file_cred; 1360 struct thread *td; 1361 { 1362 struct vattr vattr; 1363 register struct vattr *vap; 1364 int error; 1365 u_short mode; 1366 1367 #ifdef MAC 1368 error = mac_vnode_check_stat(active_cred, file_cred, vp); 1369 if (error) 1370 return (error); 1371 #endif 1372 1373 vap = &vattr; 1374 1375 /* 1376 * Initialize defaults for new and unusual fields, so that file 1377 * systems which don't support these fields don't need to know 1378 * about them. 1379 */ 1380 vap->va_birthtime.tv_sec = -1; 1381 vap->va_birthtime.tv_nsec = 0; 1382 vap->va_fsid = VNOVAL; 1383 vap->va_rdev = NODEV; 1384 1385 error = VOP_GETATTR(vp, vap, active_cred); 1386 if (error) 1387 return (error); 1388 1389 /* 1390 * Zero the spare stat fields 1391 */ 1392 bzero(sb, sizeof *sb); 1393 1394 /* 1395 * Copy from vattr table 1396 */ 1397 if (vap->va_fsid != VNOVAL) 1398 sb->st_dev = vap->va_fsid; 1399 else 1400 sb->st_dev = vp->v_mount->mnt_stat.f_fsid.val[0]; 1401 sb->st_ino = vap->va_fileid; 1402 mode = vap->va_mode; 1403 switch (vap->va_type) { 1404 case VREG: 1405 mode |= S_IFREG; 1406 break; 1407 case VDIR: 1408 mode |= S_IFDIR; 1409 break; 1410 case VBLK: 1411 mode |= S_IFBLK; 1412 break; 1413 case VCHR: 1414 mode |= S_IFCHR; 1415 break; 1416 case VLNK: 1417 mode |= S_IFLNK; 1418 break; 1419 case VSOCK: 1420 mode |= S_IFSOCK; 1421 break; 1422 case VFIFO: 1423 mode |= S_IFIFO; 1424 break; 1425 default: 1426 return (EBADF); 1427 }; 1428 sb->st_mode = mode; 1429 sb->st_nlink = vap->va_nlink; 1430 sb->st_uid = vap->va_uid; 1431 sb->st_gid = vap->va_gid; 1432 sb->st_rdev = vap->va_rdev; 1433 if (vap->va_size > OFF_MAX) 1434 return (EOVERFLOW); 1435 sb->st_size = vap->va_size; 1436 sb->st_atim = vap->va_atime; 1437 sb->st_mtim = vap->va_mtime; 1438 sb->st_ctim = vap->va_ctime; 1439 sb->st_birthtim = vap->va_birthtime; 1440 1441 /* 1442 * According to www.opengroup.org, the meaning of st_blksize is 1443 * "a filesystem-specific preferred I/O block size for this 1444 * object. In some filesystem types, this may vary from file 1445 * to file" 1446 * Use miminum/default of PAGE_SIZE (e.g. for VCHR). 1447 */ 1448 1449 sb->st_blksize = max(PAGE_SIZE, vap->va_blocksize); 1450 1451 sb->st_flags = vap->va_flags; 1452 if (priv_check(td, PRIV_VFS_GENERATION)) 1453 sb->st_gen = 0; 1454 else 1455 sb->st_gen = vap->va_gen; 1456 1457 sb->st_blocks = vap->va_bytes / S_BLKSIZE; 1458 return (0); 1459 } 1460 1461 /* 1462 * File table vnode ioctl routine. 1463 */ 1464 static int 1465 vn_ioctl(fp, com, data, active_cred, td) 1466 struct file *fp; 1467 u_long com; 1468 void *data; 1469 struct ucred *active_cred; 1470 struct thread *td; 1471 { 1472 struct vattr vattr; 1473 struct vnode *vp; 1474 int error; 1475 1476 vp = fp->f_vnode; 1477 switch (vp->v_type) { 1478 case VDIR: 1479 case VREG: 1480 switch (com) { 1481 case FIONREAD: 1482 vn_lock(vp, LK_SHARED | LK_RETRY); 1483 error = VOP_GETATTR(vp, &vattr, active_cred); 1484 VOP_UNLOCK(vp, 0); 1485 if (error == 0) 1486 *(int *)data = vattr.va_size - fp->f_offset; 1487 return (error); 1488 case FIONBIO: 1489 case FIOASYNC: 1490 return (0); 1491 default: 1492 return (VOP_IOCTL(vp, com, data, fp->f_flag, 1493 active_cred, td)); 1494 } 1495 default: 1496 return (ENOTTY); 1497 } 1498 } 1499 1500 /* 1501 * File table vnode poll routine. 1502 */ 1503 static int 1504 vn_poll(fp, events, active_cred, td) 1505 struct file *fp; 1506 int events; 1507 struct ucred *active_cred; 1508 struct thread *td; 1509 { 1510 struct vnode *vp; 1511 int error; 1512 1513 vp = fp->f_vnode; 1514 #ifdef MAC 1515 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1516 error = mac_vnode_check_poll(active_cred, fp->f_cred, vp); 1517 VOP_UNLOCK(vp, 0); 1518 if (!error) 1519 #endif 1520 1521 error = VOP_POLL(vp, events, fp->f_cred, td); 1522 return (error); 1523 } 1524 1525 /* 1526 * Acquire the requested lock and then check for validity. LK_RETRY 1527 * permits vn_lock to return doomed vnodes. 1528 */ 1529 int 1530 _vn_lock(struct vnode *vp, int flags, char *file, int line) 1531 { 1532 int error; 1533 1534 VNASSERT((flags & LK_TYPE_MASK) != 0, vp, 1535 ("vn_lock called with no locktype.")); 1536 do { 1537 #ifdef DEBUG_VFS_LOCKS 1538 KASSERT(vp->v_holdcnt != 0, 1539 ("vn_lock %p: zero hold count", vp)); 1540 #endif 1541 error = VOP_LOCK1(vp, flags, file, line); 1542 flags &= ~LK_INTERLOCK; /* Interlock is always dropped. */ 1543 KASSERT((flags & LK_RETRY) == 0 || error == 0, 1544 ("LK_RETRY set with incompatible flags (0x%x) or an error occured (%d)", 1545 flags, error)); 1546 /* 1547 * Callers specify LK_RETRY if they wish to get dead vnodes. 1548 * If RETRY is not set, we return ENOENT instead. 1549 */ 1550 if (error == 0 && vp->v_iflag & VI_DOOMED && 1551 (flags & LK_RETRY) == 0) { 1552 VOP_UNLOCK(vp, 0); 1553 error = ENOENT; 1554 break; 1555 } 1556 } while (flags & LK_RETRY && error != 0); 1557 return (error); 1558 } 1559 1560 /* 1561 * File table vnode close routine. 1562 */ 1563 static int 1564 vn_closefile(fp, td) 1565 struct file *fp; 1566 struct thread *td; 1567 { 1568 struct vnode *vp; 1569 struct flock lf; 1570 int error; 1571 1572 vp = fp->f_vnode; 1573 fp->f_ops = &badfileops; 1574 1575 if (fp->f_type == DTYPE_VNODE && fp->f_flag & FHASLOCK) 1576 vref(vp); 1577 1578 error = vn_close(vp, fp->f_flag, fp->f_cred, td); 1579 1580 if (fp->f_type == DTYPE_VNODE && fp->f_flag & FHASLOCK) { 1581 lf.l_whence = SEEK_SET; 1582 lf.l_start = 0; 1583 lf.l_len = 0; 1584 lf.l_type = F_UNLCK; 1585 (void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, F_FLOCK); 1586 vrele(vp); 1587 } 1588 return (error); 1589 } 1590 1591 static bool 1592 vn_suspendable(struct mount *mp) 1593 { 1594 1595 return (mp->mnt_op->vfs_susp_clean != NULL); 1596 } 1597 1598 /* 1599 * Preparing to start a filesystem write operation. If the operation is 1600 * permitted, then we bump the count of operations in progress and 1601 * proceed. If a suspend request is in progress, we wait until the 1602 * suspension is over, and then proceed. 1603 */ 1604 static int 1605 vn_start_write_locked(struct mount *mp, int flags) 1606 { 1607 int error, mflags; 1608 1609 mtx_assert(MNT_MTX(mp), MA_OWNED); 1610 error = 0; 1611 1612 /* 1613 * Check on status of suspension. 1614 */ 1615 if ((curthread->td_pflags & TDP_IGNSUSP) == 0 || 1616 mp->mnt_susp_owner != curthread) { 1617 mflags = ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0 ? 1618 (flags & PCATCH) : 0) | (PUSER - 1); 1619 while ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { 1620 if (flags & V_NOWAIT) { 1621 error = EWOULDBLOCK; 1622 goto unlock; 1623 } 1624 error = msleep(&mp->mnt_flag, MNT_MTX(mp), mflags, 1625 "suspfs", 0); 1626 if (error) 1627 goto unlock; 1628 } 1629 } 1630 if (flags & V_XSLEEP) 1631 goto unlock; 1632 mp->mnt_writeopcount++; 1633 unlock: 1634 if (error != 0 || (flags & V_XSLEEP) != 0) 1635 MNT_REL(mp); 1636 MNT_IUNLOCK(mp); 1637 return (error); 1638 } 1639 1640 int 1641 vn_start_write(struct vnode *vp, struct mount **mpp, int flags) 1642 { 1643 struct mount *mp; 1644 int error; 1645 1646 KASSERT((flags & V_MNTREF) == 0 || (*mpp != NULL && vp == NULL), 1647 ("V_MNTREF requires mp")); 1648 1649 error = 0; 1650 /* 1651 * If a vnode is provided, get and return the mount point that 1652 * to which it will write. 1653 */ 1654 if (vp != NULL) { 1655 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) { 1656 *mpp = NULL; 1657 if (error != EOPNOTSUPP) 1658 return (error); 1659 return (0); 1660 } 1661 } 1662 if ((mp = *mpp) == NULL) 1663 return (0); 1664 1665 if (!vn_suspendable(mp)) { 1666 if (vp != NULL || (flags & V_MNTREF) != 0) 1667 vfs_rel(mp); 1668 return (0); 1669 } 1670 1671 /* 1672 * VOP_GETWRITEMOUNT() returns with the mp refcount held through 1673 * a vfs_ref(). 1674 * As long as a vnode is not provided we need to acquire a 1675 * refcount for the provided mountpoint too, in order to 1676 * emulate a vfs_ref(). 1677 */ 1678 MNT_ILOCK(mp); 1679 if (vp == NULL && (flags & V_MNTREF) == 0) 1680 MNT_REF(mp); 1681 1682 return (vn_start_write_locked(mp, flags)); 1683 } 1684 1685 /* 1686 * Secondary suspension. Used by operations such as vop_inactive 1687 * routines that are needed by the higher level functions. These 1688 * are allowed to proceed until all the higher level functions have 1689 * completed (indicated by mnt_writeopcount dropping to zero). At that 1690 * time, these operations are halted until the suspension is over. 1691 */ 1692 int 1693 vn_start_secondary_write(struct vnode *vp, struct mount **mpp, int flags) 1694 { 1695 struct mount *mp; 1696 int error; 1697 1698 KASSERT((flags & V_MNTREF) == 0 || (*mpp != NULL && vp == NULL), 1699 ("V_MNTREF requires mp")); 1700 1701 retry: 1702 if (vp != NULL) { 1703 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) { 1704 *mpp = NULL; 1705 if (error != EOPNOTSUPP) 1706 return (error); 1707 return (0); 1708 } 1709 } 1710 /* 1711 * If we are not suspended or have not yet reached suspended 1712 * mode, then let the operation proceed. 1713 */ 1714 if ((mp = *mpp) == NULL) 1715 return (0); 1716 1717 if (!vn_suspendable(mp)) { 1718 if (vp != NULL || (flags & V_MNTREF) != 0) 1719 vfs_rel(mp); 1720 return (0); 1721 } 1722 1723 /* 1724 * VOP_GETWRITEMOUNT() returns with the mp refcount held through 1725 * a vfs_ref(). 1726 * As long as a vnode is not provided we need to acquire a 1727 * refcount for the provided mountpoint too, in order to 1728 * emulate a vfs_ref(). 1729 */ 1730 MNT_ILOCK(mp); 1731 if (vp == NULL && (flags & V_MNTREF) == 0) 1732 MNT_REF(mp); 1733 if ((mp->mnt_kern_flag & (MNTK_SUSPENDED | MNTK_SUSPEND2)) == 0) { 1734 mp->mnt_secondary_writes++; 1735 mp->mnt_secondary_accwrites++; 1736 MNT_IUNLOCK(mp); 1737 return (0); 1738 } 1739 if (flags & V_NOWAIT) { 1740 MNT_REL(mp); 1741 MNT_IUNLOCK(mp); 1742 return (EWOULDBLOCK); 1743 } 1744 /* 1745 * Wait for the suspension to finish. 1746 */ 1747 error = msleep(&mp->mnt_flag, MNT_MTX(mp), (PUSER - 1) | PDROP | 1748 ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0 ? (flags & PCATCH) : 0), 1749 "suspfs", 0); 1750 vfs_rel(mp); 1751 if (error == 0) 1752 goto retry; 1753 return (error); 1754 } 1755 1756 /* 1757 * Filesystem write operation has completed. If we are suspending and this 1758 * operation is the last one, notify the suspender that the suspension is 1759 * now in effect. 1760 */ 1761 void 1762 vn_finished_write(mp) 1763 struct mount *mp; 1764 { 1765 if (mp == NULL || !vn_suspendable(mp)) 1766 return; 1767 MNT_ILOCK(mp); 1768 MNT_REL(mp); 1769 mp->mnt_writeopcount--; 1770 if (mp->mnt_writeopcount < 0) 1771 panic("vn_finished_write: neg cnt"); 1772 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && 1773 mp->mnt_writeopcount <= 0) 1774 wakeup(&mp->mnt_writeopcount); 1775 MNT_IUNLOCK(mp); 1776 } 1777 1778 1779 /* 1780 * Filesystem secondary write operation has completed. If we are 1781 * suspending and this operation is the last one, notify the suspender 1782 * that the suspension is now in effect. 1783 */ 1784 void 1785 vn_finished_secondary_write(mp) 1786 struct mount *mp; 1787 { 1788 if (mp == NULL || !vn_suspendable(mp)) 1789 return; 1790 MNT_ILOCK(mp); 1791 MNT_REL(mp); 1792 mp->mnt_secondary_writes--; 1793 if (mp->mnt_secondary_writes < 0) 1794 panic("vn_finished_secondary_write: neg cnt"); 1795 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && 1796 mp->mnt_secondary_writes <= 0) 1797 wakeup(&mp->mnt_secondary_writes); 1798 MNT_IUNLOCK(mp); 1799 } 1800 1801 1802 1803 /* 1804 * Request a filesystem to suspend write operations. 1805 */ 1806 int 1807 vfs_write_suspend(struct mount *mp, int flags) 1808 { 1809 int error; 1810 1811 MPASS(vn_suspendable(mp)); 1812 1813 MNT_ILOCK(mp); 1814 if (mp->mnt_susp_owner == curthread) { 1815 MNT_IUNLOCK(mp); 1816 return (EALREADY); 1817 } 1818 while (mp->mnt_kern_flag & MNTK_SUSPEND) 1819 msleep(&mp->mnt_flag, MNT_MTX(mp), PUSER - 1, "wsuspfs", 0); 1820 1821 /* 1822 * Unmount holds a write reference on the mount point. If we 1823 * own busy reference and drain for writers, we deadlock with 1824 * the reference draining in the unmount path. Callers of 1825 * vfs_write_suspend() must specify VS_SKIP_UNMOUNT if 1826 * vfs_busy() reference is owned and caller is not in the 1827 * unmount context. 1828 */ 1829 if ((flags & VS_SKIP_UNMOUNT) != 0 && 1830 (mp->mnt_kern_flag & MNTK_UNMOUNT) != 0) { 1831 MNT_IUNLOCK(mp); 1832 return (EBUSY); 1833 } 1834 1835 mp->mnt_kern_flag |= MNTK_SUSPEND; 1836 mp->mnt_susp_owner = curthread; 1837 if (mp->mnt_writeopcount > 0) 1838 (void) msleep(&mp->mnt_writeopcount, 1839 MNT_MTX(mp), (PUSER - 1)|PDROP, "suspwt", 0); 1840 else 1841 MNT_IUNLOCK(mp); 1842 if ((error = VFS_SYNC(mp, MNT_SUSPEND)) != 0) 1843 vfs_write_resume(mp, 0); 1844 return (error); 1845 } 1846 1847 /* 1848 * Request a filesystem to resume write operations. 1849 */ 1850 void 1851 vfs_write_resume(struct mount *mp, int flags) 1852 { 1853 1854 MPASS(vn_suspendable(mp)); 1855 1856 MNT_ILOCK(mp); 1857 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { 1858 KASSERT(mp->mnt_susp_owner == curthread, ("mnt_susp_owner")); 1859 mp->mnt_kern_flag &= ~(MNTK_SUSPEND | MNTK_SUSPEND2 | 1860 MNTK_SUSPENDED); 1861 mp->mnt_susp_owner = NULL; 1862 wakeup(&mp->mnt_writeopcount); 1863 wakeup(&mp->mnt_flag); 1864 curthread->td_pflags &= ~TDP_IGNSUSP; 1865 if ((flags & VR_START_WRITE) != 0) { 1866 MNT_REF(mp); 1867 mp->mnt_writeopcount++; 1868 } 1869 MNT_IUNLOCK(mp); 1870 if ((flags & VR_NO_SUSPCLR) == 0) 1871 VFS_SUSP_CLEAN(mp); 1872 } else if ((flags & VR_START_WRITE) != 0) { 1873 MNT_REF(mp); 1874 vn_start_write_locked(mp, 0); 1875 } else { 1876 MNT_IUNLOCK(mp); 1877 } 1878 } 1879 1880 /* 1881 * Helper loop around vfs_write_suspend() for filesystem unmount VFS 1882 * methods. 1883 */ 1884 int 1885 vfs_write_suspend_umnt(struct mount *mp) 1886 { 1887 int error; 1888 1889 MPASS(vn_suspendable(mp)); 1890 KASSERT((curthread->td_pflags & TDP_IGNSUSP) == 0, 1891 ("vfs_write_suspend_umnt: recursed")); 1892 1893 /* dounmount() already called vn_start_write(). */ 1894 for (;;) { 1895 vn_finished_write(mp); 1896 error = vfs_write_suspend(mp, 0); 1897 if (error != 0) { 1898 vn_start_write(NULL, &mp, V_WAIT); 1899 return (error); 1900 } 1901 MNT_ILOCK(mp); 1902 if ((mp->mnt_kern_flag & MNTK_SUSPENDED) != 0) 1903 break; 1904 MNT_IUNLOCK(mp); 1905 vn_start_write(NULL, &mp, V_WAIT); 1906 } 1907 mp->mnt_kern_flag &= ~(MNTK_SUSPENDED | MNTK_SUSPEND2); 1908 wakeup(&mp->mnt_flag); 1909 MNT_IUNLOCK(mp); 1910 curthread->td_pflags |= TDP_IGNSUSP; 1911 return (0); 1912 } 1913 1914 /* 1915 * Implement kqueues for files by translating it to vnode operation. 1916 */ 1917 static int 1918 vn_kqfilter(struct file *fp, struct knote *kn) 1919 { 1920 1921 return (VOP_KQFILTER(fp->f_vnode, kn)); 1922 } 1923 1924 /* 1925 * Simplified in-kernel wrapper calls for extended attribute access. 1926 * Both calls pass in a NULL credential, authorizing as "kernel" access. 1927 * Set IO_NODELOCKED in ioflg if the vnode is already locked. 1928 */ 1929 int 1930 vn_extattr_get(struct vnode *vp, int ioflg, int attrnamespace, 1931 const char *attrname, int *buflen, char *buf, struct thread *td) 1932 { 1933 struct uio auio; 1934 struct iovec iov; 1935 int error; 1936 1937 iov.iov_len = *buflen; 1938 iov.iov_base = buf; 1939 1940 auio.uio_iov = &iov; 1941 auio.uio_iovcnt = 1; 1942 auio.uio_rw = UIO_READ; 1943 auio.uio_segflg = UIO_SYSSPACE; 1944 auio.uio_td = td; 1945 auio.uio_offset = 0; 1946 auio.uio_resid = *buflen; 1947 1948 if ((ioflg & IO_NODELOCKED) == 0) 1949 vn_lock(vp, LK_SHARED | LK_RETRY); 1950 1951 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 1952 1953 /* authorize attribute retrieval as kernel */ 1954 error = VOP_GETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, NULL, 1955 td); 1956 1957 if ((ioflg & IO_NODELOCKED) == 0) 1958 VOP_UNLOCK(vp, 0); 1959 1960 if (error == 0) { 1961 *buflen = *buflen - auio.uio_resid; 1962 } 1963 1964 return (error); 1965 } 1966 1967 /* 1968 * XXX failure mode if partially written? 1969 */ 1970 int 1971 vn_extattr_set(struct vnode *vp, int ioflg, int attrnamespace, 1972 const char *attrname, int buflen, char *buf, struct thread *td) 1973 { 1974 struct uio auio; 1975 struct iovec iov; 1976 struct mount *mp; 1977 int error; 1978 1979 iov.iov_len = buflen; 1980 iov.iov_base = buf; 1981 1982 auio.uio_iov = &iov; 1983 auio.uio_iovcnt = 1; 1984 auio.uio_rw = UIO_WRITE; 1985 auio.uio_segflg = UIO_SYSSPACE; 1986 auio.uio_td = td; 1987 auio.uio_offset = 0; 1988 auio.uio_resid = buflen; 1989 1990 if ((ioflg & IO_NODELOCKED) == 0) { 1991 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) 1992 return (error); 1993 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1994 } 1995 1996 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 1997 1998 /* authorize attribute setting as kernel */ 1999 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, td); 2000 2001 if ((ioflg & IO_NODELOCKED) == 0) { 2002 vn_finished_write(mp); 2003 VOP_UNLOCK(vp, 0); 2004 } 2005 2006 return (error); 2007 } 2008 2009 int 2010 vn_extattr_rm(struct vnode *vp, int ioflg, int attrnamespace, 2011 const char *attrname, struct thread *td) 2012 { 2013 struct mount *mp; 2014 int error; 2015 2016 if ((ioflg & IO_NODELOCKED) == 0) { 2017 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) 2018 return (error); 2019 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2020 } 2021 2022 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 2023 2024 /* authorize attribute removal as kernel */ 2025 error = VOP_DELETEEXTATTR(vp, attrnamespace, attrname, NULL, td); 2026 if (error == EOPNOTSUPP) 2027 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, NULL, 2028 NULL, td); 2029 2030 if ((ioflg & IO_NODELOCKED) == 0) { 2031 vn_finished_write(mp); 2032 VOP_UNLOCK(vp, 0); 2033 } 2034 2035 return (error); 2036 } 2037 2038 static int 2039 vn_get_ino_alloc_vget(struct mount *mp, void *arg, int lkflags, 2040 struct vnode **rvp) 2041 { 2042 2043 return (VFS_VGET(mp, *(ino_t *)arg, lkflags, rvp)); 2044 } 2045 2046 int 2047 vn_vget_ino(struct vnode *vp, ino_t ino, int lkflags, struct vnode **rvp) 2048 { 2049 2050 return (vn_vget_ino_gen(vp, vn_get_ino_alloc_vget, &ino, 2051 lkflags, rvp)); 2052 } 2053 2054 int 2055 vn_vget_ino_gen(struct vnode *vp, vn_get_ino_t alloc, void *alloc_arg, 2056 int lkflags, struct vnode **rvp) 2057 { 2058 struct mount *mp; 2059 int ltype, error; 2060 2061 ASSERT_VOP_LOCKED(vp, "vn_vget_ino_get"); 2062 mp = vp->v_mount; 2063 ltype = VOP_ISLOCKED(vp); 2064 KASSERT(ltype == LK_EXCLUSIVE || ltype == LK_SHARED, 2065 ("vn_vget_ino: vp not locked")); 2066 error = vfs_busy(mp, MBF_NOWAIT); 2067 if (error != 0) { 2068 vfs_ref(mp); 2069 VOP_UNLOCK(vp, 0); 2070 error = vfs_busy(mp, 0); 2071 vn_lock(vp, ltype | LK_RETRY); 2072 vfs_rel(mp); 2073 if (error != 0) 2074 return (ENOENT); 2075 if (vp->v_iflag & VI_DOOMED) { 2076 vfs_unbusy(mp); 2077 return (ENOENT); 2078 } 2079 } 2080 VOP_UNLOCK(vp, 0); 2081 error = alloc(mp, alloc_arg, lkflags, rvp); 2082 vfs_unbusy(mp); 2083 if (*rvp != vp) 2084 vn_lock(vp, ltype | LK_RETRY); 2085 if (vp->v_iflag & VI_DOOMED) { 2086 if (error == 0) { 2087 if (*rvp == vp) 2088 vunref(vp); 2089 else 2090 vput(*rvp); 2091 } 2092 error = ENOENT; 2093 } 2094 return (error); 2095 } 2096 2097 int 2098 vn_rlimit_fsize(const struct vnode *vp, const struct uio *uio, 2099 struct thread *td) 2100 { 2101 2102 if (vp->v_type != VREG || td == NULL) 2103 return (0); 2104 if ((uoff_t)uio->uio_offset + uio->uio_resid > 2105 lim_cur(td, RLIMIT_FSIZE)) { 2106 PROC_LOCK(td->td_proc); 2107 kern_psignal(td->td_proc, SIGXFSZ); 2108 PROC_UNLOCK(td->td_proc); 2109 return (EFBIG); 2110 } 2111 return (0); 2112 } 2113 2114 int 2115 vn_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 2116 struct thread *td) 2117 { 2118 struct vnode *vp; 2119 2120 vp = fp->f_vnode; 2121 #ifdef AUDIT 2122 vn_lock(vp, LK_SHARED | LK_RETRY); 2123 AUDIT_ARG_VNODE1(vp); 2124 VOP_UNLOCK(vp, 0); 2125 #endif 2126 return (setfmode(td, active_cred, vp, mode)); 2127 } 2128 2129 int 2130 vn_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 2131 struct thread *td) 2132 { 2133 struct vnode *vp; 2134 2135 vp = fp->f_vnode; 2136 #ifdef AUDIT 2137 vn_lock(vp, LK_SHARED | LK_RETRY); 2138 AUDIT_ARG_VNODE1(vp); 2139 VOP_UNLOCK(vp, 0); 2140 #endif 2141 return (setfown(td, active_cred, vp, uid, gid)); 2142 } 2143 2144 void 2145 vn_pages_remove(struct vnode *vp, vm_pindex_t start, vm_pindex_t end) 2146 { 2147 vm_object_t object; 2148 2149 if ((object = vp->v_object) == NULL) 2150 return; 2151 VM_OBJECT_WLOCK(object); 2152 vm_object_page_remove(object, start, end, 0); 2153 VM_OBJECT_WUNLOCK(object); 2154 } 2155 2156 int 2157 vn_bmap_seekhole(struct vnode *vp, u_long cmd, off_t *off, struct ucred *cred) 2158 { 2159 struct vattr va; 2160 daddr_t bn, bnp; 2161 uint64_t bsize; 2162 off_t noff; 2163 int error; 2164 2165 KASSERT(cmd == FIOSEEKHOLE || cmd == FIOSEEKDATA, 2166 ("Wrong command %lu", cmd)); 2167 2168 if (vn_lock(vp, LK_SHARED) != 0) 2169 return (EBADF); 2170 if (vp->v_type != VREG) { 2171 error = ENOTTY; 2172 goto unlock; 2173 } 2174 error = VOP_GETATTR(vp, &va, cred); 2175 if (error != 0) 2176 goto unlock; 2177 noff = *off; 2178 if (noff >= va.va_size) { 2179 error = ENXIO; 2180 goto unlock; 2181 } 2182 bsize = vp->v_mount->mnt_stat.f_iosize; 2183 for (bn = noff / bsize; noff < va.va_size; bn++, noff += bsize) { 2184 error = VOP_BMAP(vp, bn, NULL, &bnp, NULL, NULL); 2185 if (error == EOPNOTSUPP) { 2186 error = ENOTTY; 2187 goto unlock; 2188 } 2189 if ((bnp == -1 && cmd == FIOSEEKHOLE) || 2190 (bnp != -1 && cmd == FIOSEEKDATA)) { 2191 noff = bn * bsize; 2192 if (noff < *off) 2193 noff = *off; 2194 goto unlock; 2195 } 2196 } 2197 if (noff > va.va_size) 2198 noff = va.va_size; 2199 /* noff == va.va_size. There is an implicit hole at the end of file. */ 2200 if (cmd == FIOSEEKDATA) 2201 error = ENXIO; 2202 unlock: 2203 VOP_UNLOCK(vp, 0); 2204 if (error == 0) 2205 *off = noff; 2206 return (error); 2207 } 2208 2209 int 2210 vn_seek(struct file *fp, off_t offset, int whence, struct thread *td) 2211 { 2212 struct ucred *cred; 2213 struct vnode *vp; 2214 struct vattr vattr; 2215 off_t foffset, size; 2216 int error, noneg; 2217 2218 cred = td->td_ucred; 2219 vp = fp->f_vnode; 2220 foffset = foffset_lock(fp, 0); 2221 noneg = (vp->v_type != VCHR); 2222 error = 0; 2223 switch (whence) { 2224 case L_INCR: 2225 if (noneg && 2226 (foffset < 0 || 2227 (offset > 0 && foffset > OFF_MAX - offset))) { 2228 error = EOVERFLOW; 2229 break; 2230 } 2231 offset += foffset; 2232 break; 2233 case L_XTND: 2234 vn_lock(vp, LK_SHARED | LK_RETRY); 2235 error = VOP_GETATTR(vp, &vattr, cred); 2236 VOP_UNLOCK(vp, 0); 2237 if (error) 2238 break; 2239 2240 /* 2241 * If the file references a disk device, then fetch 2242 * the media size and use that to determine the ending 2243 * offset. 2244 */ 2245 if (vattr.va_size == 0 && vp->v_type == VCHR && 2246 fo_ioctl(fp, DIOCGMEDIASIZE, &size, cred, td) == 0) 2247 vattr.va_size = size; 2248 if (noneg && 2249 (vattr.va_size > OFF_MAX || 2250 (offset > 0 && vattr.va_size > OFF_MAX - offset))) { 2251 error = EOVERFLOW; 2252 break; 2253 } 2254 offset += vattr.va_size; 2255 break; 2256 case L_SET: 2257 break; 2258 case SEEK_DATA: 2259 error = fo_ioctl(fp, FIOSEEKDATA, &offset, cred, td); 2260 break; 2261 case SEEK_HOLE: 2262 error = fo_ioctl(fp, FIOSEEKHOLE, &offset, cred, td); 2263 break; 2264 default: 2265 error = EINVAL; 2266 } 2267 if (error == 0 && noneg && offset < 0) 2268 error = EINVAL; 2269 if (error != 0) 2270 goto drop; 2271 VFS_KNOTE_UNLOCKED(vp, 0); 2272 td->td_uretoff.tdu_off = offset; 2273 drop: 2274 foffset_unlock(fp, offset, error != 0 ? FOF_NOUPDATE : 0); 2275 return (error); 2276 } 2277 2278 int 2279 vn_utimes_perm(struct vnode *vp, struct vattr *vap, struct ucred *cred, 2280 struct thread *td) 2281 { 2282 int error; 2283 2284 /* 2285 * Grant permission if the caller is the owner of the file, or 2286 * the super-user, or has ACL_WRITE_ATTRIBUTES permission on 2287 * on the file. If the time pointer is null, then write 2288 * permission on the file is also sufficient. 2289 * 2290 * From NFSv4.1, draft 21, 6.2.1.3.1, Discussion of Mask Attributes: 2291 * A user having ACL_WRITE_DATA or ACL_WRITE_ATTRIBUTES 2292 * will be allowed to set the times [..] to the current 2293 * server time. 2294 */ 2295 error = VOP_ACCESSX(vp, VWRITE_ATTRIBUTES, cred, td); 2296 if (error != 0 && (vap->va_vaflags & VA_UTIMES_NULL) != 0) 2297 error = VOP_ACCESS(vp, VWRITE, cred, td); 2298 return (error); 2299 } 2300 2301 int 2302 vn_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 2303 { 2304 struct vnode *vp; 2305 int error; 2306 2307 if (fp->f_type == DTYPE_FIFO) 2308 kif->kf_type = KF_TYPE_FIFO; 2309 else 2310 kif->kf_type = KF_TYPE_VNODE; 2311 vp = fp->f_vnode; 2312 vref(vp); 2313 FILEDESC_SUNLOCK(fdp); 2314 error = vn_fill_kinfo_vnode(vp, kif); 2315 vrele(vp); 2316 FILEDESC_SLOCK(fdp); 2317 return (error); 2318 } 2319 2320 int 2321 vn_fill_kinfo_vnode(struct vnode *vp, struct kinfo_file *kif) 2322 { 2323 struct vattr va; 2324 char *fullpath, *freepath; 2325 int error; 2326 2327 kif->kf_vnode_type = vntype_to_kinfo(vp->v_type); 2328 freepath = NULL; 2329 fullpath = "-"; 2330 error = vn_fullpath(curthread, vp, &fullpath, &freepath); 2331 if (error == 0) { 2332 strlcpy(kif->kf_path, fullpath, sizeof(kif->kf_path)); 2333 } 2334 if (freepath != NULL) 2335 free(freepath, M_TEMP); 2336 2337 /* 2338 * Retrieve vnode attributes. 2339 */ 2340 va.va_fsid = VNOVAL; 2341 va.va_rdev = NODEV; 2342 vn_lock(vp, LK_SHARED | LK_RETRY); 2343 error = VOP_GETATTR(vp, &va, curthread->td_ucred); 2344 VOP_UNLOCK(vp, 0); 2345 if (error != 0) 2346 return (error); 2347 if (va.va_fsid != VNOVAL) 2348 kif->kf_un.kf_file.kf_file_fsid = va.va_fsid; 2349 else 2350 kif->kf_un.kf_file.kf_file_fsid = 2351 vp->v_mount->mnt_stat.f_fsid.val[0]; 2352 kif->kf_un.kf_file.kf_file_fileid = va.va_fileid; 2353 kif->kf_un.kf_file.kf_file_mode = MAKEIMODE(va.va_type, va.va_mode); 2354 kif->kf_un.kf_file.kf_file_size = va.va_size; 2355 kif->kf_un.kf_file.kf_file_rdev = va.va_rdev; 2356 return (0); 2357 } 2358 2359 int 2360 vn_mmap(struct file *fp, vm_map_t map, vm_offset_t *addr, vm_size_t size, 2361 vm_prot_t prot, vm_prot_t cap_maxprot, int flags, vm_ooffset_t foff, 2362 struct thread *td) 2363 { 2364 #ifdef HWPMC_HOOKS 2365 struct pmckern_map_in pkm; 2366 #endif 2367 struct mount *mp; 2368 struct vnode *vp; 2369 vm_object_t object; 2370 vm_prot_t maxprot; 2371 boolean_t writecounted; 2372 int error; 2373 2374 #if defined(COMPAT_FREEBSD7) || defined(COMPAT_FREEBSD6) || \ 2375 defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4) 2376 /* 2377 * POSIX shared-memory objects are defined to have 2378 * kernel persistence, and are not defined to support 2379 * read(2)/write(2) -- or even open(2). Thus, we can 2380 * use MAP_ASYNC to trade on-disk coherence for speed. 2381 * The shm_open(3) library routine turns on the FPOSIXSHM 2382 * flag to request this behavior. 2383 */ 2384 if ((fp->f_flag & FPOSIXSHM) != 0) 2385 flags |= MAP_NOSYNC; 2386 #endif 2387 vp = fp->f_vnode; 2388 2389 /* 2390 * Ensure that file and memory protections are 2391 * compatible. Note that we only worry about 2392 * writability if mapping is shared; in this case, 2393 * current and max prot are dictated by the open file. 2394 * XXX use the vnode instead? Problem is: what 2395 * credentials do we use for determination? What if 2396 * proc does a setuid? 2397 */ 2398 mp = vp->v_mount; 2399 if (mp != NULL && (mp->mnt_flag & MNT_NOEXEC) != 0) 2400 maxprot = VM_PROT_NONE; 2401 else 2402 maxprot = VM_PROT_EXECUTE; 2403 if ((fp->f_flag & FREAD) != 0) 2404 maxprot |= VM_PROT_READ; 2405 else if ((prot & VM_PROT_READ) != 0) 2406 return (EACCES); 2407 2408 /* 2409 * If we are sharing potential changes via MAP_SHARED and we 2410 * are trying to get write permission although we opened it 2411 * without asking for it, bail out. 2412 */ 2413 if ((flags & MAP_SHARED) != 0) { 2414 if ((fp->f_flag & FWRITE) != 0) 2415 maxprot |= VM_PROT_WRITE; 2416 else if ((prot & VM_PROT_WRITE) != 0) 2417 return (EACCES); 2418 } else { 2419 maxprot |= VM_PROT_WRITE; 2420 cap_maxprot |= VM_PROT_WRITE; 2421 } 2422 maxprot &= cap_maxprot; 2423 2424 writecounted = FALSE; 2425 error = vm_mmap_vnode(td, size, prot, &maxprot, &flags, vp, 2426 &foff, &object, &writecounted); 2427 if (error != 0) 2428 return (error); 2429 error = vm_mmap_object(map, addr, size, prot, maxprot, flags, object, 2430 foff, writecounted, td); 2431 if (error != 0) { 2432 /* 2433 * If this mapping was accounted for in the vnode's 2434 * writecount, then undo that now. 2435 */ 2436 if (writecounted) 2437 vnode_pager_release_writecount(object, 0, size); 2438 vm_object_deallocate(object); 2439 } 2440 #ifdef HWPMC_HOOKS 2441 /* Inform hwpmc(4) if an executable is being mapped. */ 2442 if (error == 0 && (prot & VM_PROT_EXECUTE) != 0) { 2443 pkm.pm_file = vp; 2444 pkm.pm_address = (uintptr_t) addr; 2445 PMC_CALL_HOOK(td, PMC_FN_MMAP, (void *) &pkm); 2446 } 2447 #endif 2448 return (error); 2449 } 2450