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sys/kern/vfs_vnops.c
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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 if ((vn_open_flags & VN_OPEN_INVFS) == 0) 221 bwillwrite(); 222 if ((error = namei(ndp)) != 0) 223 return (error); 224 if (ndp->ni_vp == NULL) { 225 VATTR_NULL(vap); 226 vap->va_type = VREG; 227 vap->va_mode = cmode; 228 if (fmode & O_EXCL) 229 vap->va_vaflags |= VA_EXCLUSIVE; 230 if (vn_start_write(ndp->ni_dvp, &mp, V_NOWAIT) != 0) { 231 NDFREE(ndp, NDF_ONLY_PNBUF); 232 vput(ndp->ni_dvp); 233 if ((error = vn_start_write(NULL, &mp, 234 V_XSLEEP | PCATCH)) != 0) 235 return (error); 236 goto restart; 237 } 238 if ((vn_open_flags & VN_OPEN_NAMECACHE) != 0) 239 ndp->ni_cnd.cn_flags |= MAKEENTRY; 240 #ifdef MAC 241 error = mac_vnode_check_create(cred, ndp->ni_dvp, 242 &ndp->ni_cnd, vap); 243 if (error == 0) 244 #endif 245 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp, 246 &ndp->ni_cnd, vap); 247 vput(ndp->ni_dvp); 248 vn_finished_write(mp); 249 if (error) { 250 NDFREE(ndp, NDF_ONLY_PNBUF); 251 return (error); 252 } 253 fmode &= ~O_TRUNC; 254 vp = ndp->ni_vp; 255 } else { 256 if (ndp->ni_dvp == ndp->ni_vp) 257 vrele(ndp->ni_dvp); 258 else 259 vput(ndp->ni_dvp); 260 ndp->ni_dvp = NULL; 261 vp = ndp->ni_vp; 262 if (fmode & O_EXCL) { 263 error = EEXIST; 264 goto bad; 265 } 266 if (vp->v_type == VDIR) { 267 error = EISDIR; 268 goto bad; 269 } 270 fmode &= ~O_CREAT; 271 } 272 } else { 273 ndp->ni_cnd.cn_nameiop = LOOKUP; 274 ndp->ni_cnd.cn_flags = ISOPEN | 275 ((fmode & O_NOFOLLOW) ? NOFOLLOW : FOLLOW) | LOCKLEAF; 276 if (!(fmode & FWRITE)) 277 ndp->ni_cnd.cn_flags |= LOCKSHARED; 278 if (!(vn_open_flags & VN_OPEN_NOAUDIT)) 279 ndp->ni_cnd.cn_flags |= AUDITVNODE1; 280 if (vn_open_flags & VN_OPEN_NOCAPCHECK) 281 ndp->ni_cnd.cn_flags |= NOCAPCHECK; 282 if ((error = namei(ndp)) != 0) 283 return (error); 284 vp = ndp->ni_vp; 285 } 286 error = vn_open_vnode(vp, fmode, cred, td, fp); 287 if (error) 288 goto bad; 289 *flagp = fmode; 290 return (0); 291 bad: 292 NDFREE(ndp, NDF_ONLY_PNBUF); 293 vput(vp); 294 *flagp = fmode; 295 ndp->ni_vp = NULL; 296 return (error); 297 } 298 299 /* 300 * Common code for vnode open operations once a vnode is located. 301 * Check permissions, and call the VOP_OPEN routine. 302 */ 303 int 304 vn_open_vnode(struct vnode *vp, int fmode, struct ucred *cred, 305 struct thread *td, struct file *fp) 306 { 307 accmode_t accmode; 308 struct flock lf; 309 int error, lock_flags, type; 310 311 if (vp->v_type == VLNK) 312 return (EMLINK); 313 if (vp->v_type == VSOCK) 314 return (EOPNOTSUPP); 315 if (vp->v_type != VDIR && fmode & O_DIRECTORY) 316 return (ENOTDIR); 317 accmode = 0; 318 if (fmode & (FWRITE | O_TRUNC)) { 319 if (vp->v_type == VDIR) 320 return (EISDIR); 321 accmode |= VWRITE; 322 } 323 if (fmode & FREAD) 324 accmode |= VREAD; 325 if (fmode & FEXEC) 326 accmode |= VEXEC; 327 if ((fmode & O_APPEND) && (fmode & FWRITE)) 328 accmode |= VAPPEND; 329 #ifdef MAC 330 if (fmode & O_CREAT) 331 accmode |= VCREAT; 332 if (fmode & O_VERIFY) 333 accmode |= VVERIFY; 334 error = mac_vnode_check_open(cred, vp, accmode); 335 if (error) 336 return (error); 337 338 accmode &= ~(VCREAT | VVERIFY); 339 #endif 340 if ((fmode & O_CREAT) == 0) { 341 if (accmode & VWRITE) { 342 error = vn_writechk(vp); 343 if (error) 344 return (error); 345 } 346 if (accmode) { 347 error = VOP_ACCESS(vp, accmode, cred, td); 348 if (error) 349 return (error); 350 } 351 } 352 if (vp->v_type == VFIFO && VOP_ISLOCKED(vp) != LK_EXCLUSIVE) 353 vn_lock(vp, LK_UPGRADE | LK_RETRY); 354 if ((error = VOP_OPEN(vp, fmode, cred, td, fp)) != 0) 355 return (error); 356 357 while ((fmode & (O_EXLOCK | O_SHLOCK)) != 0) { 358 KASSERT(fp != NULL, ("open with flock requires fp")); 359 if (fp->f_type != DTYPE_NONE && fp->f_type != DTYPE_VNODE) { 360 error = EOPNOTSUPP; 361 break; 362 } 363 lock_flags = VOP_ISLOCKED(vp); 364 VOP_UNLOCK(vp, 0); 365 lf.l_whence = SEEK_SET; 366 lf.l_start = 0; 367 lf.l_len = 0; 368 if (fmode & O_EXLOCK) 369 lf.l_type = F_WRLCK; 370 else 371 lf.l_type = F_RDLCK; 372 type = F_FLOCK; 373 if ((fmode & FNONBLOCK) == 0) 374 type |= F_WAIT; 375 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, type); 376 if (error == 0) 377 fp->f_flag |= FHASLOCK; 378 vn_lock(vp, lock_flags | LK_RETRY); 379 if (error != 0) 380 break; 381 if ((vp->v_iflag & VI_DOOMED) != 0) { 382 error = ENOENT; 383 break; 384 } 385 386 /* 387 * Another thread might have used this vnode as an 388 * executable while the vnode lock was dropped. 389 * Ensure the vnode is still able to be opened for 390 * writing after the lock has been obtained. 391 */ 392 if ((accmode & VWRITE) != 0) 393 error = vn_writechk(vp); 394 break; 395 } 396 397 if (error != 0) { 398 fp->f_flag |= FOPENFAILED; 399 fp->f_vnode = vp; 400 if (fp->f_ops == &badfileops) { 401 fp->f_type = DTYPE_VNODE; 402 fp->f_ops = &vnops; 403 } 404 vref(vp); 405 } else if ((fmode & FWRITE) != 0) { 406 VOP_ADD_WRITECOUNT(vp, 1); 407 CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d", 408 __func__, vp, vp->v_writecount); 409 } 410 ASSERT_VOP_LOCKED(vp, "vn_open_vnode"); 411 return (error); 412 } 413 414 /* 415 * Check for write permissions on the specified vnode. 416 * Prototype text segments cannot be written. 417 */ 418 int 419 vn_writechk(struct vnode *vp) 420 { 421 422 ASSERT_VOP_LOCKED(vp, "vn_writechk"); 423 /* 424 * If there's shared text associated with 425 * the vnode, try to free it up once. If 426 * we fail, we can't allow writing. 427 */ 428 if (VOP_IS_TEXT(vp)) 429 return (ETXTBSY); 430 431 return (0); 432 } 433 434 /* 435 * Vnode close call 436 */ 437 static int 438 vn_close1(struct vnode *vp, int flags, struct ucred *file_cred, 439 struct thread *td, bool keep_ref) 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 AUDIT_ARG_VNODE1(vp); 453 if ((flags & (FWRITE | FOPENFAILED)) == FWRITE) { 454 VNASSERT(vp->v_writecount > 0, vp, 455 ("vn_close: negative writecount")); 456 VOP_ADD_WRITECOUNT(vp, -1); 457 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d", 458 __func__, vp, vp->v_writecount); 459 } 460 error = VOP_CLOSE(vp, flags, file_cred, td); 461 if (keep_ref) 462 VOP_UNLOCK(vp, 0); 463 else 464 vput(vp); 465 vn_finished_write(mp); 466 return (error); 467 } 468 469 int 470 vn_close(struct vnode *vp, int flags, struct ucred *file_cred, 471 struct thread *td) 472 { 473 474 return (vn_close1(vp, flags, file_cred, td, false)); 475 } 476 477 /* 478 * Heuristic to detect sequential operation. 479 */ 480 static int 481 sequential_heuristic(struct uio *uio, struct file *fp) 482 { 483 484 ASSERT_VOP_LOCKED(fp->f_vnode, __func__); 485 if (fp->f_flag & FRDAHEAD) 486 return (fp->f_seqcount << IO_SEQSHIFT); 487 488 /* 489 * Offset 0 is handled specially. open() sets f_seqcount to 1 so 490 * that the first I/O is normally considered to be slightly 491 * sequential. Seeking to offset 0 doesn't change sequentiality 492 * unless previous seeks have reduced f_seqcount to 0, in which 493 * case offset 0 is not special. 494 */ 495 if ((uio->uio_offset == 0 && fp->f_seqcount > 0) || 496 uio->uio_offset == fp->f_nextoff) { 497 /* 498 * f_seqcount is in units of fixed-size blocks so that it 499 * depends mainly on the amount of sequential I/O and not 500 * much on the number of sequential I/O's. The fixed size 501 * of 16384 is hard-coded here since it is (not quite) just 502 * a magic size that works well here. This size is more 503 * closely related to the best I/O size for real disks than 504 * to any block size used by software. 505 */ 506 fp->f_seqcount += howmany(uio->uio_resid, 16384); 507 if (fp->f_seqcount > IO_SEQMAX) 508 fp->f_seqcount = IO_SEQMAX; 509 return (fp->f_seqcount << IO_SEQSHIFT); 510 } 511 512 /* Not sequential. Quickly draw-down sequentiality. */ 513 if (fp->f_seqcount > 1) 514 fp->f_seqcount = 1; 515 else 516 fp->f_seqcount = 0; 517 return (0); 518 } 519 520 /* 521 * Package up an I/O request on a vnode into a uio and do it. 522 */ 523 int 524 vn_rdwr(enum uio_rw rw, struct vnode *vp, void *base, int len, off_t offset, 525 enum uio_seg segflg, int ioflg, struct ucred *active_cred, 526 struct ucred *file_cred, ssize_t *aresid, struct thread *td) 527 { 528 struct uio auio; 529 struct iovec aiov; 530 struct mount *mp; 531 struct ucred *cred; 532 void *rl_cookie; 533 struct vn_io_fault_args args; 534 int error, lock_flags; 535 536 if (offset < 0 && vp->v_type != VCHR) 537 return (EINVAL); 538 auio.uio_iov = &aiov; 539 auio.uio_iovcnt = 1; 540 aiov.iov_base = base; 541 aiov.iov_len = len; 542 auio.uio_resid = len; 543 auio.uio_offset = offset; 544 auio.uio_segflg = segflg; 545 auio.uio_rw = rw; 546 auio.uio_td = td; 547 error = 0; 548 549 if ((ioflg & IO_NODELOCKED) == 0) { 550 if ((ioflg & IO_RANGELOCKED) == 0) { 551 if (rw == UIO_READ) { 552 rl_cookie = vn_rangelock_rlock(vp, offset, 553 offset + len); 554 } else { 555 rl_cookie = vn_rangelock_wlock(vp, offset, 556 offset + len); 557 } 558 } else 559 rl_cookie = NULL; 560 mp = NULL; 561 if (rw == UIO_WRITE) { 562 if (vp->v_type != VCHR && 563 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) 564 != 0) 565 goto out; 566 if (MNT_SHARED_WRITES(mp) || 567 ((mp == NULL) && MNT_SHARED_WRITES(vp->v_mount))) 568 lock_flags = LK_SHARED; 569 else 570 lock_flags = LK_EXCLUSIVE; 571 } else 572 lock_flags = LK_SHARED; 573 vn_lock(vp, lock_flags | LK_RETRY); 574 } else 575 rl_cookie = NULL; 576 577 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 578 #ifdef MAC 579 if ((ioflg & IO_NOMACCHECK) == 0) { 580 if (rw == UIO_READ) 581 error = mac_vnode_check_read(active_cred, file_cred, 582 vp); 583 else 584 error = mac_vnode_check_write(active_cred, file_cred, 585 vp); 586 } 587 #endif 588 if (error == 0) { 589 if (file_cred != NULL) 590 cred = file_cred; 591 else 592 cred = active_cred; 593 if (do_vn_io_fault(vp, &auio)) { 594 args.kind = VN_IO_FAULT_VOP; 595 args.cred = cred; 596 args.flags = ioflg; 597 args.args.vop_args.vp = vp; 598 error = vn_io_fault1(vp, &auio, &args, td); 599 } else if (rw == UIO_READ) { 600 error = VOP_READ(vp, &auio, ioflg, cred); 601 } else /* if (rw == UIO_WRITE) */ { 602 error = VOP_WRITE(vp, &auio, ioflg, cred); 603 } 604 } 605 if (aresid) 606 *aresid = auio.uio_resid; 607 else 608 if (auio.uio_resid && error == 0) 609 error = EIO; 610 if ((ioflg & IO_NODELOCKED) == 0) { 611 VOP_UNLOCK(vp, 0); 612 if (mp != NULL) 613 vn_finished_write(mp); 614 } 615 out: 616 if (rl_cookie != NULL) 617 vn_rangelock_unlock(vp, rl_cookie); 618 return (error); 619 } 620 621 /* 622 * Package up an I/O request on a vnode into a uio and do it. The I/O 623 * request is split up into smaller chunks and we try to avoid saturating 624 * the buffer cache while potentially holding a vnode locked, so we 625 * check bwillwrite() before calling vn_rdwr(). We also call kern_yield() 626 * to give other processes a chance to lock the vnode (either other processes 627 * core'ing the same binary, or unrelated processes scanning the directory). 628 */ 629 int 630 vn_rdwr_inchunks(rw, vp, base, len, offset, segflg, ioflg, active_cred, 631 file_cred, aresid, td) 632 enum uio_rw rw; 633 struct vnode *vp; 634 void *base; 635 size_t len; 636 off_t offset; 637 enum uio_seg segflg; 638 int ioflg; 639 struct ucred *active_cred; 640 struct ucred *file_cred; 641 size_t *aresid; 642 struct thread *td; 643 { 644 int error = 0; 645 ssize_t iaresid; 646 647 do { 648 int chunk; 649 650 /* 651 * Force `offset' to a multiple of MAXBSIZE except possibly 652 * for the first chunk, so that filesystems only need to 653 * write full blocks except possibly for the first and last 654 * chunks. 655 */ 656 chunk = MAXBSIZE - (uoff_t)offset % MAXBSIZE; 657 658 if (chunk > len) 659 chunk = len; 660 if (rw != UIO_READ && vp->v_type == VREG) 661 bwillwrite(); 662 iaresid = 0; 663 error = vn_rdwr(rw, vp, base, chunk, offset, segflg, 664 ioflg, active_cred, file_cred, &iaresid, td); 665 len -= chunk; /* aresid calc already includes length */ 666 if (error) 667 break; 668 offset += chunk; 669 base = (char *)base + chunk; 670 kern_yield(PRI_USER); 671 } while (len); 672 if (aresid) 673 *aresid = len + iaresid; 674 return (error); 675 } 676 677 off_t 678 foffset_lock(struct file *fp, int flags) 679 { 680 struct mtx *mtxp; 681 off_t res; 682 683 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed")); 684 685 #if OFF_MAX <= LONG_MAX 686 /* 687 * Caller only wants the current f_offset value. Assume that 688 * the long and shorter integer types reads are atomic. 689 */ 690 if ((flags & FOF_NOLOCK) != 0) 691 return (fp->f_offset); 692 #endif 693 694 /* 695 * According to McKusick the vn lock was protecting f_offset here. 696 * It is now protected by the FOFFSET_LOCKED flag. 697 */ 698 mtxp = mtx_pool_find(mtxpool_sleep, fp); 699 mtx_lock(mtxp); 700 if ((flags & FOF_NOLOCK) == 0) { 701 while (fp->f_vnread_flags & FOFFSET_LOCKED) { 702 fp->f_vnread_flags |= FOFFSET_LOCK_WAITING; 703 msleep(&fp->f_vnread_flags, mtxp, PUSER -1, 704 "vofflock", 0); 705 } 706 fp->f_vnread_flags |= FOFFSET_LOCKED; 707 } 708 res = fp->f_offset; 709 mtx_unlock(mtxp); 710 return (res); 711 } 712 713 void 714 foffset_unlock(struct file *fp, off_t val, int flags) 715 { 716 struct mtx *mtxp; 717 718 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed")); 719 720 #if OFF_MAX <= LONG_MAX 721 if ((flags & FOF_NOLOCK) != 0) { 722 if ((flags & FOF_NOUPDATE) == 0) 723 fp->f_offset = val; 724 if ((flags & FOF_NEXTOFF) != 0) 725 fp->f_nextoff = val; 726 return; 727 } 728 #endif 729 730 mtxp = mtx_pool_find(mtxpool_sleep, fp); 731 mtx_lock(mtxp); 732 if ((flags & FOF_NOUPDATE) == 0) 733 fp->f_offset = val; 734 if ((flags & FOF_NEXTOFF) != 0) 735 fp->f_nextoff = val; 736 if ((flags & FOF_NOLOCK) == 0) { 737 KASSERT((fp->f_vnread_flags & FOFFSET_LOCKED) != 0, 738 ("Lost FOFFSET_LOCKED")); 739 if (fp->f_vnread_flags & FOFFSET_LOCK_WAITING) 740 wakeup(&fp->f_vnread_flags); 741 fp->f_vnread_flags = 0; 742 } 743 mtx_unlock(mtxp); 744 } 745 746 void 747 foffset_lock_uio(struct file *fp, struct uio *uio, int flags) 748 { 749 750 if ((flags & FOF_OFFSET) == 0) 751 uio->uio_offset = foffset_lock(fp, flags); 752 } 753 754 void 755 foffset_unlock_uio(struct file *fp, struct uio *uio, int flags) 756 { 757 758 if ((flags & FOF_OFFSET) == 0) 759 foffset_unlock(fp, uio->uio_offset, flags); 760 } 761 762 static int 763 get_advice(struct file *fp, struct uio *uio) 764 { 765 struct mtx *mtxp; 766 int ret; 767 768 ret = POSIX_FADV_NORMAL; 769 if (fp->f_advice == NULL || fp->f_vnode->v_type != VREG) 770 return (ret); 771 772 mtxp = mtx_pool_find(mtxpool_sleep, fp); 773 mtx_lock(mtxp); 774 if (fp->f_advice != NULL && 775 uio->uio_offset >= fp->f_advice->fa_start && 776 uio->uio_offset + uio->uio_resid <= fp->f_advice->fa_end) 777 ret = fp->f_advice->fa_advice; 778 mtx_unlock(mtxp); 779 return (ret); 780 } 781 782 /* 783 * File table vnode read routine. 784 */ 785 static int 786 vn_read(fp, uio, active_cred, flags, td) 787 struct file *fp; 788 struct uio *uio; 789 struct ucred *active_cred; 790 int flags; 791 struct thread *td; 792 { 793 struct vnode *vp; 794 off_t orig_offset; 795 int error, ioflag; 796 int advice; 797 798 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", 799 uio->uio_td, td)); 800 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET")); 801 vp = fp->f_vnode; 802 ioflag = 0; 803 if (fp->f_flag & FNONBLOCK) 804 ioflag |= IO_NDELAY; 805 if (fp->f_flag & O_DIRECT) 806 ioflag |= IO_DIRECT; 807 advice = get_advice(fp, uio); 808 vn_lock(vp, LK_SHARED | LK_RETRY); 809 810 switch (advice) { 811 case POSIX_FADV_NORMAL: 812 case POSIX_FADV_SEQUENTIAL: 813 case POSIX_FADV_NOREUSE: 814 ioflag |= sequential_heuristic(uio, fp); 815 break; 816 case POSIX_FADV_RANDOM: 817 /* Disable read-ahead for random I/O. */ 818 break; 819 } 820 orig_offset = uio->uio_offset; 821 822 #ifdef MAC 823 error = mac_vnode_check_read(active_cred, fp->f_cred, vp); 824 if (error == 0) 825 #endif 826 error = VOP_READ(vp, uio, ioflag, fp->f_cred); 827 fp->f_nextoff = uio->uio_offset; 828 VOP_UNLOCK(vp, 0); 829 if (error == 0 && advice == POSIX_FADV_NOREUSE && 830 orig_offset != uio->uio_offset) 831 /* 832 * Use POSIX_FADV_DONTNEED to flush pages and buffers 833 * for the backing file after a POSIX_FADV_NOREUSE 834 * read(2). 835 */ 836 error = VOP_ADVISE(vp, orig_offset, uio->uio_offset - 1, 837 POSIX_FADV_DONTNEED); 838 return (error); 839 } 840 841 /* 842 * File table vnode write routine. 843 */ 844 static int 845 vn_write(fp, uio, active_cred, flags, td) 846 struct file *fp; 847 struct uio *uio; 848 struct ucred *active_cred; 849 int flags; 850 struct thread *td; 851 { 852 struct vnode *vp; 853 struct mount *mp; 854 off_t orig_offset; 855 int error, ioflag, lock_flags; 856 int advice; 857 858 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", 859 uio->uio_td, td)); 860 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET")); 861 vp = fp->f_vnode; 862 if (vp->v_type == VREG) 863 bwillwrite(); 864 ioflag = IO_UNIT; 865 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 866 ioflag |= IO_APPEND; 867 if (fp->f_flag & FNONBLOCK) 868 ioflag |= IO_NDELAY; 869 if (fp->f_flag & O_DIRECT) 870 ioflag |= IO_DIRECT; 871 if ((fp->f_flag & O_FSYNC) || 872 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS))) 873 ioflag |= IO_SYNC; 874 mp = NULL; 875 if (vp->v_type != VCHR && 876 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0) 877 goto unlock; 878 879 advice = get_advice(fp, uio); 880 881 if (MNT_SHARED_WRITES(mp) || 882 (mp == NULL && MNT_SHARED_WRITES(vp->v_mount))) { 883 lock_flags = LK_SHARED; 884 } else { 885 lock_flags = LK_EXCLUSIVE; 886 } 887 888 vn_lock(vp, lock_flags | LK_RETRY); 889 switch (advice) { 890 case POSIX_FADV_NORMAL: 891 case POSIX_FADV_SEQUENTIAL: 892 case POSIX_FADV_NOREUSE: 893 ioflag |= sequential_heuristic(uio, fp); 894 break; 895 case POSIX_FADV_RANDOM: 896 /* XXX: Is this correct? */ 897 break; 898 } 899 orig_offset = uio->uio_offset; 900 901 #ifdef MAC 902 error = mac_vnode_check_write(active_cred, fp->f_cred, vp); 903 if (error == 0) 904 #endif 905 error = VOP_WRITE(vp, uio, ioflag, fp->f_cred); 906 fp->f_nextoff = uio->uio_offset; 907 VOP_UNLOCK(vp, 0); 908 if (vp->v_type != VCHR) 909 vn_finished_write(mp); 910 if (error == 0 && advice == POSIX_FADV_NOREUSE && 911 orig_offset != uio->uio_offset) 912 /* 913 * Use POSIX_FADV_DONTNEED to flush pages and buffers 914 * for the backing file after a POSIX_FADV_NOREUSE 915 * write(2). 916 */ 917 error = VOP_ADVISE(vp, orig_offset, uio->uio_offset - 1, 918 POSIX_FADV_DONTNEED); 919 unlock: 920 return (error); 921 } 922 923 /* 924 * The vn_io_fault() is a wrapper around vn_read() and vn_write() to 925 * prevent the following deadlock: 926 * 927 * Assume that the thread A reads from the vnode vp1 into userspace 928 * buffer buf1 backed by the pages of vnode vp2. If a page in buf1 is 929 * currently not resident, then system ends up with the call chain 930 * vn_read() -> VOP_READ(vp1) -> uiomove() -> [Page Fault] -> 931 * vm_fault(buf1) -> vnode_pager_getpages(vp2) -> VOP_GETPAGES(vp2) 932 * which establishes lock order vp1->vn_lock, then vp2->vn_lock. 933 * If, at the same time, thread B reads from vnode vp2 into buffer buf2 934 * backed by the pages of vnode vp1, and some page in buf2 is not 935 * resident, we get a reversed order vp2->vn_lock, then vp1->vn_lock. 936 * 937 * To prevent the lock order reversal and deadlock, vn_io_fault() does 938 * not allow page faults to happen during VOP_READ() or VOP_WRITE(). 939 * Instead, it first tries to do the whole range i/o with pagefaults 940 * disabled. If all pages in the i/o buffer are resident and mapped, 941 * VOP will succeed (ignoring the genuine filesystem errors). 942 * Otherwise, we get back EFAULT, and vn_io_fault() falls back to do 943 * i/o in chunks, with all pages in the chunk prefaulted and held 944 * using vm_fault_quick_hold_pages(). 945 * 946 * Filesystems using this deadlock avoidance scheme should use the 947 * array of the held pages from uio, saved in the curthread->td_ma, 948 * instead of doing uiomove(). A helper function 949 * vn_io_fault_uiomove() converts uiomove request into 950 * uiomove_fromphys() over td_ma array. 951 * 952 * Since vnode locks do not cover the whole i/o anymore, rangelocks 953 * make the current i/o request atomic with respect to other i/os and 954 * truncations. 955 */ 956 957 /* 958 * Decode vn_io_fault_args and perform the corresponding i/o. 959 */ 960 static int 961 vn_io_fault_doio(struct vn_io_fault_args *args, struct uio *uio, 962 struct thread *td) 963 { 964 int error, save; 965 966 error = 0; 967 save = vm_fault_disable_pagefaults(); 968 switch (args->kind) { 969 case VN_IO_FAULT_FOP: 970 error = (args->args.fop_args.doio)(args->args.fop_args.fp, 971 uio, args->cred, args->flags, td); 972 break; 973 case VN_IO_FAULT_VOP: 974 if (uio->uio_rw == UIO_READ) { 975 error = VOP_READ(args->args.vop_args.vp, uio, 976 args->flags, args->cred); 977 } else if (uio->uio_rw == UIO_WRITE) { 978 error = VOP_WRITE(args->args.vop_args.vp, uio, 979 args->flags, args->cred); 980 } 981 break; 982 default: 983 panic("vn_io_fault_doio: unknown kind of io %d %d", 984 args->kind, uio->uio_rw); 985 } 986 vm_fault_enable_pagefaults(save); 987 return (error); 988 } 989 990 static int 991 vn_io_fault_touch(char *base, const struct uio *uio) 992 { 993 int r; 994 995 r = fubyte(base); 996 if (r == -1 || (uio->uio_rw == UIO_READ && subyte(base, r) == -1)) 997 return (EFAULT); 998 return (0); 999 } 1000 1001 static int 1002 vn_io_fault_prefault_user(const struct uio *uio) 1003 { 1004 char *base; 1005 const struct iovec *iov; 1006 size_t len; 1007 ssize_t resid; 1008 int error, i; 1009 1010 KASSERT(uio->uio_segflg == UIO_USERSPACE, 1011 ("vn_io_fault_prefault userspace")); 1012 1013 error = i = 0; 1014 iov = uio->uio_iov; 1015 resid = uio->uio_resid; 1016 base = iov->iov_base; 1017 len = iov->iov_len; 1018 while (resid > 0) { 1019 error = vn_io_fault_touch(base, uio); 1020 if (error != 0) 1021 break; 1022 if (len < PAGE_SIZE) { 1023 if (len != 0) { 1024 error = vn_io_fault_touch(base + len - 1, uio); 1025 if (error != 0) 1026 break; 1027 resid -= len; 1028 } 1029 if (++i >= uio->uio_iovcnt) 1030 break; 1031 iov = uio->uio_iov + i; 1032 base = iov->iov_base; 1033 len = iov->iov_len; 1034 } else { 1035 len -= PAGE_SIZE; 1036 base += PAGE_SIZE; 1037 resid -= PAGE_SIZE; 1038 } 1039 } 1040 return (error); 1041 } 1042 1043 /* 1044 * Common code for vn_io_fault(), agnostic to the kind of i/o request. 1045 * Uses vn_io_fault_doio() to make the call to an actual i/o function. 1046 * Used from vn_rdwr() and vn_io_fault(), which encode the i/o request 1047 * into args and call vn_io_fault1() to handle faults during the user 1048 * mode buffer accesses. 1049 */ 1050 static int 1051 vn_io_fault1(struct vnode *vp, struct uio *uio, struct vn_io_fault_args *args, 1052 struct thread *td) 1053 { 1054 vm_page_t ma[io_hold_cnt + 2]; 1055 struct uio *uio_clone, short_uio; 1056 struct iovec short_iovec[1]; 1057 vm_page_t *prev_td_ma; 1058 vm_prot_t prot; 1059 vm_offset_t addr, end; 1060 size_t len, resid; 1061 ssize_t adv; 1062 int error, cnt, saveheld, prev_td_ma_cnt; 1063 1064 if (vn_io_fault_prefault) { 1065 error = vn_io_fault_prefault_user(uio); 1066 if (error != 0) 1067 return (error); /* Or ignore ? */ 1068 } 1069 1070 prot = uio->uio_rw == UIO_READ ? VM_PROT_WRITE : VM_PROT_READ; 1071 1072 /* 1073 * The UFS follows IO_UNIT directive and replays back both 1074 * uio_offset and uio_resid if an error is encountered during the 1075 * operation. But, since the iovec may be already advanced, 1076 * uio is still in an inconsistent state. 1077 * 1078 * Cache a copy of the original uio, which is advanced to the redo 1079 * point using UIO_NOCOPY below. 1080 */ 1081 uio_clone = cloneuio(uio); 1082 resid = uio->uio_resid; 1083 1084 short_uio.uio_segflg = UIO_USERSPACE; 1085 short_uio.uio_rw = uio->uio_rw; 1086 short_uio.uio_td = uio->uio_td; 1087 1088 error = vn_io_fault_doio(args, uio, td); 1089 if (error != EFAULT) 1090 goto out; 1091 1092 atomic_add_long(&vn_io_faults_cnt, 1); 1093 uio_clone->uio_segflg = UIO_NOCOPY; 1094 uiomove(NULL, resid - uio->uio_resid, uio_clone); 1095 uio_clone->uio_segflg = uio->uio_segflg; 1096 1097 saveheld = curthread_pflags_set(TDP_UIOHELD); 1098 prev_td_ma = td->td_ma; 1099 prev_td_ma_cnt = td->td_ma_cnt; 1100 1101 while (uio_clone->uio_resid != 0) { 1102 len = uio_clone->uio_iov->iov_len; 1103 if (len == 0) { 1104 KASSERT(uio_clone->uio_iovcnt >= 1, 1105 ("iovcnt underflow")); 1106 uio_clone->uio_iov++; 1107 uio_clone->uio_iovcnt--; 1108 continue; 1109 } 1110 if (len > io_hold_cnt * PAGE_SIZE) 1111 len = io_hold_cnt * PAGE_SIZE; 1112 addr = (uintptr_t)uio_clone->uio_iov->iov_base; 1113 end = round_page(addr + len); 1114 if (end < addr) { 1115 error = EFAULT; 1116 break; 1117 } 1118 cnt = atop(end - trunc_page(addr)); 1119 /* 1120 * A perfectly misaligned address and length could cause 1121 * both the start and the end of the chunk to use partial 1122 * page. +2 accounts for such a situation. 1123 */ 1124 cnt = vm_fault_quick_hold_pages(&td->td_proc->p_vmspace->vm_map, 1125 addr, len, prot, ma, io_hold_cnt + 2); 1126 if (cnt == -1) { 1127 error = EFAULT; 1128 break; 1129 } 1130 short_uio.uio_iov = &short_iovec[0]; 1131 short_iovec[0].iov_base = (void *)addr; 1132 short_uio.uio_iovcnt = 1; 1133 short_uio.uio_resid = short_iovec[0].iov_len = len; 1134 short_uio.uio_offset = uio_clone->uio_offset; 1135 td->td_ma = ma; 1136 td->td_ma_cnt = cnt; 1137 1138 error = vn_io_fault_doio(args, &short_uio, td); 1139 vm_page_unhold_pages(ma, cnt); 1140 adv = len - short_uio.uio_resid; 1141 1142 uio_clone->uio_iov->iov_base = 1143 (char *)uio_clone->uio_iov->iov_base + adv; 1144 uio_clone->uio_iov->iov_len -= adv; 1145 uio_clone->uio_resid -= adv; 1146 uio_clone->uio_offset += adv; 1147 1148 uio->uio_resid -= adv; 1149 uio->uio_offset += adv; 1150 1151 if (error != 0 || adv == 0) 1152 break; 1153 } 1154 td->td_ma = prev_td_ma; 1155 td->td_ma_cnt = prev_td_ma_cnt; 1156 curthread_pflags_restore(saveheld); 1157 out: 1158 free(uio_clone, M_IOV); 1159 return (error); 1160 } 1161 1162 static int 1163 vn_io_fault(struct file *fp, struct uio *uio, struct ucred *active_cred, 1164 int flags, struct thread *td) 1165 { 1166 fo_rdwr_t *doio; 1167 struct vnode *vp; 1168 void *rl_cookie; 1169 struct vn_io_fault_args args; 1170 int error; 1171 1172 doio = uio->uio_rw == UIO_READ ? vn_read : vn_write; 1173 vp = fp->f_vnode; 1174 foffset_lock_uio(fp, uio, flags); 1175 if (do_vn_io_fault(vp, uio)) { 1176 args.kind = VN_IO_FAULT_FOP; 1177 args.args.fop_args.fp = fp; 1178 args.args.fop_args.doio = doio; 1179 args.cred = active_cred; 1180 args.flags = flags | FOF_OFFSET; 1181 if (uio->uio_rw == UIO_READ) { 1182 rl_cookie = vn_rangelock_rlock(vp, uio->uio_offset, 1183 uio->uio_offset + uio->uio_resid); 1184 } else if ((fp->f_flag & O_APPEND) != 0 || 1185 (flags & FOF_OFFSET) == 0) { 1186 /* For appenders, punt and lock the whole range. */ 1187 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 1188 } else { 1189 rl_cookie = vn_rangelock_wlock(vp, uio->uio_offset, 1190 uio->uio_offset + uio->uio_resid); 1191 } 1192 error = vn_io_fault1(vp, uio, &args, td); 1193 vn_rangelock_unlock(vp, rl_cookie); 1194 } else { 1195 error = doio(fp, uio, active_cred, flags | FOF_OFFSET, td); 1196 } 1197 foffset_unlock_uio(fp, uio, flags); 1198 return (error); 1199 } 1200 1201 /* 1202 * Helper function to perform the requested uiomove operation using 1203 * the held pages for io->uio_iov[0].iov_base buffer instead of 1204 * copyin/copyout. Access to the pages with uiomove_fromphys() 1205 * instead of iov_base prevents page faults that could occur due to 1206 * pmap_collect() invalidating the mapping created by 1207 * vm_fault_quick_hold_pages(), or pageout daemon, page laundry or 1208 * object cleanup revoking the write access from page mappings. 1209 * 1210 * Filesystems specified MNTK_NO_IOPF shall use vn_io_fault_uiomove() 1211 * instead of plain uiomove(). 1212 */ 1213 int 1214 vn_io_fault_uiomove(char *data, int xfersize, struct uio *uio) 1215 { 1216 struct uio transp_uio; 1217 struct iovec transp_iov[1]; 1218 struct thread *td; 1219 size_t adv; 1220 int error, pgadv; 1221 1222 td = curthread; 1223 if ((td->td_pflags & TDP_UIOHELD) == 0 || 1224 uio->uio_segflg != UIO_USERSPACE) 1225 return (uiomove(data, xfersize, uio)); 1226 1227 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt)); 1228 transp_iov[0].iov_base = data; 1229 transp_uio.uio_iov = &transp_iov[0]; 1230 transp_uio.uio_iovcnt = 1; 1231 if (xfersize > uio->uio_resid) 1232 xfersize = uio->uio_resid; 1233 transp_uio.uio_resid = transp_iov[0].iov_len = xfersize; 1234 transp_uio.uio_offset = 0; 1235 transp_uio.uio_segflg = UIO_SYSSPACE; 1236 /* 1237 * Since transp_iov points to data, and td_ma page array 1238 * corresponds to original uio->uio_iov, we need to invert the 1239 * direction of the i/o operation as passed to 1240 * uiomove_fromphys(). 1241 */ 1242 switch (uio->uio_rw) { 1243 case UIO_WRITE: 1244 transp_uio.uio_rw = UIO_READ; 1245 break; 1246 case UIO_READ: 1247 transp_uio.uio_rw = UIO_WRITE; 1248 break; 1249 } 1250 transp_uio.uio_td = uio->uio_td; 1251 error = uiomove_fromphys(td->td_ma, 1252 ((vm_offset_t)uio->uio_iov->iov_base) & PAGE_MASK, 1253 xfersize, &transp_uio); 1254 adv = xfersize - transp_uio.uio_resid; 1255 pgadv = 1256 (((vm_offset_t)uio->uio_iov->iov_base + adv) >> PAGE_SHIFT) - 1257 (((vm_offset_t)uio->uio_iov->iov_base) >> PAGE_SHIFT); 1258 td->td_ma += pgadv; 1259 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt, 1260 pgadv)); 1261 td->td_ma_cnt -= pgadv; 1262 uio->uio_iov->iov_base = (char *)uio->uio_iov->iov_base + adv; 1263 uio->uio_iov->iov_len -= adv; 1264 uio->uio_resid -= adv; 1265 uio->uio_offset += adv; 1266 return (error); 1267 } 1268 1269 int 1270 vn_io_fault_pgmove(vm_page_t ma[], vm_offset_t offset, int xfersize, 1271 struct uio *uio) 1272 { 1273 struct thread *td; 1274 vm_offset_t iov_base; 1275 int cnt, pgadv; 1276 1277 td = curthread; 1278 if ((td->td_pflags & TDP_UIOHELD) == 0 || 1279 uio->uio_segflg != UIO_USERSPACE) 1280 return (uiomove_fromphys(ma, offset, xfersize, uio)); 1281 1282 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt)); 1283 cnt = xfersize > uio->uio_resid ? uio->uio_resid : xfersize; 1284 iov_base = (vm_offset_t)uio->uio_iov->iov_base; 1285 switch (uio->uio_rw) { 1286 case UIO_WRITE: 1287 pmap_copy_pages(td->td_ma, iov_base & PAGE_MASK, ma, 1288 offset, cnt); 1289 break; 1290 case UIO_READ: 1291 pmap_copy_pages(ma, offset, td->td_ma, iov_base & PAGE_MASK, 1292 cnt); 1293 break; 1294 } 1295 pgadv = ((iov_base + cnt) >> PAGE_SHIFT) - (iov_base >> PAGE_SHIFT); 1296 td->td_ma += pgadv; 1297 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt, 1298 pgadv)); 1299 td->td_ma_cnt -= pgadv; 1300 uio->uio_iov->iov_base = (char *)(iov_base + cnt); 1301 uio->uio_iov->iov_len -= cnt; 1302 uio->uio_resid -= cnt; 1303 uio->uio_offset += cnt; 1304 return (0); 1305 } 1306 1307 1308 /* 1309 * File table truncate routine. 1310 */ 1311 static int 1312 vn_truncate(struct file *fp, off_t length, struct ucred *active_cred, 1313 struct thread *td) 1314 { 1315 struct vattr vattr; 1316 struct mount *mp; 1317 struct vnode *vp; 1318 void *rl_cookie; 1319 int error; 1320 1321 vp = fp->f_vnode; 1322 1323 /* 1324 * Lock the whole range for truncation. Otherwise split i/o 1325 * might happen partly before and partly after the truncation. 1326 */ 1327 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 1328 error = vn_start_write(vp, &mp, V_WAIT | PCATCH); 1329 if (error) 1330 goto out1; 1331 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1332 if (vp->v_type == VDIR) { 1333 error = EISDIR; 1334 goto out; 1335 } 1336 #ifdef MAC 1337 error = mac_vnode_check_write(active_cred, fp->f_cred, vp); 1338 if (error) 1339 goto out; 1340 #endif 1341 error = vn_writechk(vp); 1342 if (error == 0) { 1343 VATTR_NULL(&vattr); 1344 vattr.va_size = length; 1345 if ((fp->f_flag & O_FSYNC) != 0) 1346 vattr.va_vaflags |= VA_SYNC; 1347 error = VOP_SETATTR(vp, &vattr, fp->f_cred); 1348 } 1349 out: 1350 VOP_UNLOCK(vp, 0); 1351 vn_finished_write(mp); 1352 out1: 1353 vn_rangelock_unlock(vp, rl_cookie); 1354 return (error); 1355 } 1356 1357 /* 1358 * File table vnode stat routine. 1359 */ 1360 static int 1361 vn_statfile(fp, sb, active_cred, td) 1362 struct file *fp; 1363 struct stat *sb; 1364 struct ucred *active_cred; 1365 struct thread *td; 1366 { 1367 struct vnode *vp = fp->f_vnode; 1368 int error; 1369 1370 vn_lock(vp, LK_SHARED | LK_RETRY); 1371 error = vn_stat(vp, sb, active_cred, fp->f_cred, td); 1372 VOP_UNLOCK(vp, 0); 1373 1374 return (error); 1375 } 1376 1377 /* 1378 * Stat a vnode; implementation for the stat syscall 1379 */ 1380 int 1381 vn_stat(struct vnode *vp, struct stat *sb, struct ucred *active_cred, 1382 struct ucred *file_cred, struct thread *td) 1383 { 1384 struct vattr vattr; 1385 struct vattr *vap; 1386 int error; 1387 u_short mode; 1388 1389 AUDIT_ARG_VNODE1(vp); 1390 #ifdef MAC 1391 error = mac_vnode_check_stat(active_cred, file_cred, vp); 1392 if (error) 1393 return (error); 1394 #endif 1395 1396 vap = &vattr; 1397 1398 /* 1399 * Initialize defaults for new and unusual fields, so that file 1400 * systems which don't support these fields don't need to know 1401 * about them. 1402 */ 1403 vap->va_birthtime.tv_sec = -1; 1404 vap->va_birthtime.tv_nsec = 0; 1405 vap->va_fsid = VNOVAL; 1406 vap->va_rdev = NODEV; 1407 1408 error = VOP_GETATTR(vp, vap, active_cred); 1409 if (error) 1410 return (error); 1411 1412 /* 1413 * Zero the spare stat fields 1414 */ 1415 bzero(sb, sizeof *sb); 1416 1417 /* 1418 * Copy from vattr table 1419 */ 1420 if (vap->va_fsid != VNOVAL) 1421 sb->st_dev = vap->va_fsid; 1422 else 1423 sb->st_dev = vp->v_mount->mnt_stat.f_fsid.val[0]; 1424 sb->st_ino = vap->va_fileid; 1425 mode = vap->va_mode; 1426 switch (vap->va_type) { 1427 case VREG: 1428 mode |= S_IFREG; 1429 break; 1430 case VDIR: 1431 mode |= S_IFDIR; 1432 break; 1433 case VBLK: 1434 mode |= S_IFBLK; 1435 break; 1436 case VCHR: 1437 mode |= S_IFCHR; 1438 break; 1439 case VLNK: 1440 mode |= S_IFLNK; 1441 break; 1442 case VSOCK: 1443 mode |= S_IFSOCK; 1444 break; 1445 case VFIFO: 1446 mode |= S_IFIFO; 1447 break; 1448 default: 1449 return (EBADF); 1450 } 1451 sb->st_mode = mode; 1452 sb->st_nlink = vap->va_nlink; 1453 sb->st_uid = vap->va_uid; 1454 sb->st_gid = vap->va_gid; 1455 sb->st_rdev = vap->va_rdev; 1456 if (vap->va_size > OFF_MAX) 1457 return (EOVERFLOW); 1458 sb->st_size = vap->va_size; 1459 sb->st_atim = vap->va_atime; 1460 sb->st_mtim = vap->va_mtime; 1461 sb->st_ctim = vap->va_ctime; 1462 sb->st_birthtim = vap->va_birthtime; 1463 1464 /* 1465 * According to www.opengroup.org, the meaning of st_blksize is 1466 * "a filesystem-specific preferred I/O block size for this 1467 * object. In some filesystem types, this may vary from file 1468 * to file" 1469 * Use minimum/default of PAGE_SIZE (e.g. for VCHR). 1470 */ 1471 1472 sb->st_blksize = max(PAGE_SIZE, vap->va_blocksize); 1473 1474 sb->st_flags = vap->va_flags; 1475 if (priv_check(td, PRIV_VFS_GENERATION)) 1476 sb->st_gen = 0; 1477 else 1478 sb->st_gen = vap->va_gen; 1479 1480 sb->st_blocks = vap->va_bytes / S_BLKSIZE; 1481 return (0); 1482 } 1483 1484 /* 1485 * File table vnode ioctl routine. 1486 */ 1487 static int 1488 vn_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 1489 struct thread *td) 1490 { 1491 struct vattr vattr; 1492 struct vnode *vp; 1493 int error; 1494 1495 vp = fp->f_vnode; 1496 switch (vp->v_type) { 1497 case VDIR: 1498 case VREG: 1499 switch (com) { 1500 case FIONREAD: 1501 vn_lock(vp, LK_SHARED | LK_RETRY); 1502 error = VOP_GETATTR(vp, &vattr, active_cred); 1503 VOP_UNLOCK(vp, 0); 1504 if (error == 0) 1505 *(int *)data = vattr.va_size - fp->f_offset; 1506 return (error); 1507 case FIONBIO: 1508 case FIOASYNC: 1509 return (0); 1510 default: 1511 return (VOP_IOCTL(vp, com, data, fp->f_flag, 1512 active_cred, td)); 1513 } 1514 default: 1515 return (ENOTTY); 1516 } 1517 } 1518 1519 /* 1520 * File table vnode poll routine. 1521 */ 1522 static int 1523 vn_poll(struct file *fp, int events, struct ucred *active_cred, 1524 struct thread *td) 1525 { 1526 struct vnode *vp; 1527 int error; 1528 1529 vp = fp->f_vnode; 1530 #ifdef MAC 1531 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1532 AUDIT_ARG_VNODE1(vp); 1533 error = mac_vnode_check_poll(active_cred, fp->f_cred, vp); 1534 VOP_UNLOCK(vp, 0); 1535 if (!error) 1536 #endif 1537 1538 error = VOP_POLL(vp, events, fp->f_cred, td); 1539 return (error); 1540 } 1541 1542 /* 1543 * Acquire the requested lock and then check for validity. LK_RETRY 1544 * permits vn_lock to return doomed vnodes. 1545 */ 1546 int 1547 _vn_lock(struct vnode *vp, int flags, char *file, int line) 1548 { 1549 int error; 1550 1551 VNASSERT((flags & LK_TYPE_MASK) != 0, vp, 1552 ("vn_lock: no locktype")); 1553 VNASSERT(vp->v_holdcnt != 0, vp, ("vn_lock: zero hold count")); 1554 retry: 1555 error = VOP_LOCK1(vp, flags, file, line); 1556 flags &= ~LK_INTERLOCK; /* Interlock is always dropped. */ 1557 KASSERT((flags & LK_RETRY) == 0 || error == 0, 1558 ("vn_lock: error %d incompatible with flags %#x", error, flags)); 1559 1560 if ((flags & LK_RETRY) == 0) { 1561 if (error == 0 && (vp->v_iflag & VI_DOOMED) != 0) { 1562 VOP_UNLOCK(vp, 0); 1563 error = ENOENT; 1564 } 1565 } else if (error != 0) 1566 goto retry; 1567 return (error); 1568 } 1569 1570 /* 1571 * File table vnode close routine. 1572 */ 1573 static int 1574 vn_closefile(struct file *fp, struct thread *td) 1575 { 1576 struct vnode *vp; 1577 struct flock lf; 1578 int error; 1579 bool ref; 1580 1581 vp = fp->f_vnode; 1582 fp->f_ops = &badfileops; 1583 ref= (fp->f_flag & FHASLOCK) != 0 && fp->f_type == DTYPE_VNODE; 1584 1585 error = vn_close1(vp, fp->f_flag, fp->f_cred, td, ref); 1586 1587 if (__predict_false(ref)) { 1588 lf.l_whence = SEEK_SET; 1589 lf.l_start = 0; 1590 lf.l_len = 0; 1591 lf.l_type = F_UNLCK; 1592 (void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, F_FLOCK); 1593 vrele(vp); 1594 } 1595 return (error); 1596 } 1597 1598 static bool 1599 vn_suspendable(struct mount *mp) 1600 { 1601 1602 return (mp->mnt_op->vfs_susp_clean != NULL); 1603 } 1604 1605 /* 1606 * Preparing to start a filesystem write operation. If the operation is 1607 * permitted, then we bump the count of operations in progress and 1608 * proceed. If a suspend request is in progress, we wait until the 1609 * suspension is over, and then proceed. 1610 */ 1611 static int 1612 vn_start_write_locked(struct mount *mp, int flags) 1613 { 1614 int error, mflags; 1615 1616 mtx_assert(MNT_MTX(mp), MA_OWNED); 1617 error = 0; 1618 1619 /* 1620 * Check on status of suspension. 1621 */ 1622 if ((curthread->td_pflags & TDP_IGNSUSP) == 0 || 1623 mp->mnt_susp_owner != curthread) { 1624 mflags = ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0 ? 1625 (flags & PCATCH) : 0) | (PUSER - 1); 1626 while ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { 1627 if (flags & V_NOWAIT) { 1628 error = EWOULDBLOCK; 1629 goto unlock; 1630 } 1631 error = msleep(&mp->mnt_flag, MNT_MTX(mp), mflags, 1632 "suspfs", 0); 1633 if (error) 1634 goto unlock; 1635 } 1636 } 1637 if (flags & V_XSLEEP) 1638 goto unlock; 1639 mp->mnt_writeopcount++; 1640 unlock: 1641 if (error != 0 || (flags & V_XSLEEP) != 0) 1642 MNT_REL(mp); 1643 MNT_IUNLOCK(mp); 1644 return (error); 1645 } 1646 1647 int 1648 vn_start_write(struct vnode *vp, struct mount **mpp, int flags) 1649 { 1650 struct mount *mp; 1651 int error; 1652 1653 KASSERT((flags & V_MNTREF) == 0 || (*mpp != NULL && vp == NULL), 1654 ("V_MNTREF requires mp")); 1655 1656 error = 0; 1657 /* 1658 * If a vnode is provided, get and return the mount point that 1659 * to which it will write. 1660 */ 1661 if (vp != NULL) { 1662 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) { 1663 *mpp = NULL; 1664 if (error != EOPNOTSUPP) 1665 return (error); 1666 return (0); 1667 } 1668 } 1669 if ((mp = *mpp) == NULL) 1670 return (0); 1671 1672 if (!vn_suspendable(mp)) { 1673 if (vp != NULL || (flags & V_MNTREF) != 0) 1674 vfs_rel(mp); 1675 return (0); 1676 } 1677 1678 /* 1679 * VOP_GETWRITEMOUNT() returns with the mp refcount held through 1680 * a vfs_ref(). 1681 * As long as a vnode is not provided we need to acquire a 1682 * refcount for the provided mountpoint too, in order to 1683 * emulate a vfs_ref(). 1684 */ 1685 MNT_ILOCK(mp); 1686 if (vp == NULL && (flags & V_MNTREF) == 0) 1687 MNT_REF(mp); 1688 1689 return (vn_start_write_locked(mp, flags)); 1690 } 1691 1692 /* 1693 * Secondary suspension. Used by operations such as vop_inactive 1694 * routines that are needed by the higher level functions. These 1695 * are allowed to proceed until all the higher level functions have 1696 * completed (indicated by mnt_writeopcount dropping to zero). At that 1697 * time, these operations are halted until the suspension is over. 1698 */ 1699 int 1700 vn_start_secondary_write(struct vnode *vp, struct mount **mpp, int flags) 1701 { 1702 struct mount *mp; 1703 int error; 1704 1705 KASSERT((flags & V_MNTREF) == 0 || (*mpp != NULL && vp == NULL), 1706 ("V_MNTREF requires mp")); 1707 1708 retry: 1709 if (vp != NULL) { 1710 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) { 1711 *mpp = NULL; 1712 if (error != EOPNOTSUPP) 1713 return (error); 1714 return (0); 1715 } 1716 } 1717 /* 1718 * If we are not suspended or have not yet reached suspended 1719 * mode, then let the operation proceed. 1720 */ 1721 if ((mp = *mpp) == NULL) 1722 return (0); 1723 1724 if (!vn_suspendable(mp)) { 1725 if (vp != NULL || (flags & V_MNTREF) != 0) 1726 vfs_rel(mp); 1727 return (0); 1728 } 1729 1730 /* 1731 * VOP_GETWRITEMOUNT() returns with the mp refcount held through 1732 * a vfs_ref(). 1733 * As long as a vnode is not provided we need to acquire a 1734 * refcount for the provided mountpoint too, in order to 1735 * emulate a vfs_ref(). 1736 */ 1737 MNT_ILOCK(mp); 1738 if (vp == NULL && (flags & V_MNTREF) == 0) 1739 MNT_REF(mp); 1740 if ((mp->mnt_kern_flag & (MNTK_SUSPENDED | MNTK_SUSPEND2)) == 0) { 1741 mp->mnt_secondary_writes++; 1742 mp->mnt_secondary_accwrites++; 1743 MNT_IUNLOCK(mp); 1744 return (0); 1745 } 1746 if (flags & V_NOWAIT) { 1747 MNT_REL(mp); 1748 MNT_IUNLOCK(mp); 1749 return (EWOULDBLOCK); 1750 } 1751 /* 1752 * Wait for the suspension to finish. 1753 */ 1754 error = msleep(&mp->mnt_flag, MNT_MTX(mp), (PUSER - 1) | PDROP | 1755 ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0 ? (flags & PCATCH) : 0), 1756 "suspfs", 0); 1757 vfs_rel(mp); 1758 if (error == 0) 1759 goto retry; 1760 return (error); 1761 } 1762 1763 /* 1764 * Filesystem write operation has completed. If we are suspending and this 1765 * operation is the last one, notify the suspender that the suspension is 1766 * now in effect. 1767 */ 1768 void 1769 vn_finished_write(struct mount *mp) 1770 { 1771 if (mp == NULL || !vn_suspendable(mp)) 1772 return; 1773 MNT_ILOCK(mp); 1774 MNT_REL(mp); 1775 mp->mnt_writeopcount--; 1776 if (mp->mnt_writeopcount < 0) 1777 panic("vn_finished_write: neg cnt"); 1778 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && 1779 mp->mnt_writeopcount <= 0) 1780 wakeup(&mp->mnt_writeopcount); 1781 MNT_IUNLOCK(mp); 1782 } 1783 1784 1785 /* 1786 * Filesystem secondary write operation has completed. If we are 1787 * suspending and this operation is the last one, notify the suspender 1788 * that the suspension is now in effect. 1789 */ 1790 void 1791 vn_finished_secondary_write(struct mount *mp) 1792 { 1793 if (mp == NULL || !vn_suspendable(mp)) 1794 return; 1795 MNT_ILOCK(mp); 1796 MNT_REL(mp); 1797 mp->mnt_secondary_writes--; 1798 if (mp->mnt_secondary_writes < 0) 1799 panic("vn_finished_secondary_write: neg cnt"); 1800 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && 1801 mp->mnt_secondary_writes <= 0) 1802 wakeup(&mp->mnt_secondary_writes); 1803 MNT_IUNLOCK(mp); 1804 } 1805 1806 1807 1808 /* 1809 * Request a filesystem to suspend write operations. 1810 */ 1811 int 1812 vfs_write_suspend(struct mount *mp, int flags) 1813 { 1814 int error; 1815 1816 MPASS(vn_suspendable(mp)); 1817 1818 MNT_ILOCK(mp); 1819 if (mp->mnt_susp_owner == curthread) { 1820 MNT_IUNLOCK(mp); 1821 return (EALREADY); 1822 } 1823 while (mp->mnt_kern_flag & MNTK_SUSPEND) 1824 msleep(&mp->mnt_flag, MNT_MTX(mp), PUSER - 1, "wsuspfs", 0); 1825 1826 /* 1827 * Unmount holds a write reference on the mount point. If we 1828 * own busy reference and drain for writers, we deadlock with 1829 * the reference draining in the unmount path. Callers of 1830 * vfs_write_suspend() must specify VS_SKIP_UNMOUNT if 1831 * vfs_busy() reference is owned and caller is not in the 1832 * unmount context. 1833 */ 1834 if ((flags & VS_SKIP_UNMOUNT) != 0 && 1835 (mp->mnt_kern_flag & MNTK_UNMOUNT) != 0) { 1836 MNT_IUNLOCK(mp); 1837 return (EBUSY); 1838 } 1839 1840 mp->mnt_kern_flag |= MNTK_SUSPEND; 1841 mp->mnt_susp_owner = curthread; 1842 if (mp->mnt_writeopcount > 0) 1843 (void) msleep(&mp->mnt_writeopcount, 1844 MNT_MTX(mp), (PUSER - 1)|PDROP, "suspwt", 0); 1845 else 1846 MNT_IUNLOCK(mp); 1847 if ((error = VFS_SYNC(mp, MNT_SUSPEND)) != 0) 1848 vfs_write_resume(mp, 0); 1849 return (error); 1850 } 1851 1852 /* 1853 * Request a filesystem to resume write operations. 1854 */ 1855 void 1856 vfs_write_resume(struct mount *mp, int flags) 1857 { 1858 1859 MPASS(vn_suspendable(mp)); 1860 1861 MNT_ILOCK(mp); 1862 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { 1863 KASSERT(mp->mnt_susp_owner == curthread, ("mnt_susp_owner")); 1864 mp->mnt_kern_flag &= ~(MNTK_SUSPEND | MNTK_SUSPEND2 | 1865 MNTK_SUSPENDED); 1866 mp->mnt_susp_owner = NULL; 1867 wakeup(&mp->mnt_writeopcount); 1868 wakeup(&mp->mnt_flag); 1869 curthread->td_pflags &= ~TDP_IGNSUSP; 1870 if ((flags & VR_START_WRITE) != 0) { 1871 MNT_REF(mp); 1872 mp->mnt_writeopcount++; 1873 } 1874 MNT_IUNLOCK(mp); 1875 if ((flags & VR_NO_SUSPCLR) == 0) 1876 VFS_SUSP_CLEAN(mp); 1877 } else if ((flags & VR_START_WRITE) != 0) { 1878 MNT_REF(mp); 1879 vn_start_write_locked(mp, 0); 1880 } else { 1881 MNT_IUNLOCK(mp); 1882 } 1883 } 1884 1885 /* 1886 * Helper loop around vfs_write_suspend() for filesystem unmount VFS 1887 * methods. 1888 */ 1889 int 1890 vfs_write_suspend_umnt(struct mount *mp) 1891 { 1892 int error; 1893 1894 MPASS(vn_suspendable(mp)); 1895 KASSERT((curthread->td_pflags & TDP_IGNSUSP) == 0, 1896 ("vfs_write_suspend_umnt: recursed")); 1897 1898 /* dounmount() already called vn_start_write(). */ 1899 for (;;) { 1900 vn_finished_write(mp); 1901 error = vfs_write_suspend(mp, 0); 1902 if (error != 0) { 1903 vn_start_write(NULL, &mp, V_WAIT); 1904 return (error); 1905 } 1906 MNT_ILOCK(mp); 1907 if ((mp->mnt_kern_flag & MNTK_SUSPENDED) != 0) 1908 break; 1909 MNT_IUNLOCK(mp); 1910 vn_start_write(NULL, &mp, V_WAIT); 1911 } 1912 mp->mnt_kern_flag &= ~(MNTK_SUSPENDED | MNTK_SUSPEND2); 1913 wakeup(&mp->mnt_flag); 1914 MNT_IUNLOCK(mp); 1915 curthread->td_pflags |= TDP_IGNSUSP; 1916 return (0); 1917 } 1918 1919 /* 1920 * Implement kqueues for files by translating it to vnode operation. 1921 */ 1922 static int 1923 vn_kqfilter(struct file *fp, struct knote *kn) 1924 { 1925 1926 return (VOP_KQFILTER(fp->f_vnode, kn)); 1927 } 1928 1929 /* 1930 * Simplified in-kernel wrapper calls for extended attribute access. 1931 * Both calls pass in a NULL credential, authorizing as "kernel" access. 1932 * Set IO_NODELOCKED in ioflg if the vnode is already locked. 1933 */ 1934 int 1935 vn_extattr_get(struct vnode *vp, int ioflg, int attrnamespace, 1936 const char *attrname, int *buflen, char *buf, struct thread *td) 1937 { 1938 struct uio auio; 1939 struct iovec iov; 1940 int error; 1941 1942 iov.iov_len = *buflen; 1943 iov.iov_base = buf; 1944 1945 auio.uio_iov = &iov; 1946 auio.uio_iovcnt = 1; 1947 auio.uio_rw = UIO_READ; 1948 auio.uio_segflg = UIO_SYSSPACE; 1949 auio.uio_td = td; 1950 auio.uio_offset = 0; 1951 auio.uio_resid = *buflen; 1952 1953 if ((ioflg & IO_NODELOCKED) == 0) 1954 vn_lock(vp, LK_SHARED | LK_RETRY); 1955 1956 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 1957 1958 /* authorize attribute retrieval as kernel */ 1959 error = VOP_GETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, NULL, 1960 td); 1961 1962 if ((ioflg & IO_NODELOCKED) == 0) 1963 VOP_UNLOCK(vp, 0); 1964 1965 if (error == 0) { 1966 *buflen = *buflen - auio.uio_resid; 1967 } 1968 1969 return (error); 1970 } 1971 1972 /* 1973 * XXX failure mode if partially written? 1974 */ 1975 int 1976 vn_extattr_set(struct vnode *vp, int ioflg, int attrnamespace, 1977 const char *attrname, int buflen, char *buf, struct thread *td) 1978 { 1979 struct uio auio; 1980 struct iovec iov; 1981 struct mount *mp; 1982 int error; 1983 1984 iov.iov_len = buflen; 1985 iov.iov_base = buf; 1986 1987 auio.uio_iov = &iov; 1988 auio.uio_iovcnt = 1; 1989 auio.uio_rw = UIO_WRITE; 1990 auio.uio_segflg = UIO_SYSSPACE; 1991 auio.uio_td = td; 1992 auio.uio_offset = 0; 1993 auio.uio_resid = buflen; 1994 1995 if ((ioflg & IO_NODELOCKED) == 0) { 1996 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) 1997 return (error); 1998 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1999 } 2000 2001 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 2002 2003 /* authorize attribute setting as kernel */ 2004 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, td); 2005 2006 if ((ioflg & IO_NODELOCKED) == 0) { 2007 vn_finished_write(mp); 2008 VOP_UNLOCK(vp, 0); 2009 } 2010 2011 return (error); 2012 } 2013 2014 int 2015 vn_extattr_rm(struct vnode *vp, int ioflg, int attrnamespace, 2016 const char *attrname, struct thread *td) 2017 { 2018 struct mount *mp; 2019 int error; 2020 2021 if ((ioflg & IO_NODELOCKED) == 0) { 2022 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) 2023 return (error); 2024 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2025 } 2026 2027 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 2028 2029 /* authorize attribute removal as kernel */ 2030 error = VOP_DELETEEXTATTR(vp, attrnamespace, attrname, NULL, td); 2031 if (error == EOPNOTSUPP) 2032 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, NULL, 2033 NULL, td); 2034 2035 if ((ioflg & IO_NODELOCKED) == 0) { 2036 vn_finished_write(mp); 2037 VOP_UNLOCK(vp, 0); 2038 } 2039 2040 return (error); 2041 } 2042 2043 static int 2044 vn_get_ino_alloc_vget(struct mount *mp, void *arg, int lkflags, 2045 struct vnode **rvp) 2046 { 2047 2048 return (VFS_VGET(mp, *(ino_t *)arg, lkflags, rvp)); 2049 } 2050 2051 int 2052 vn_vget_ino(struct vnode *vp, ino_t ino, int lkflags, struct vnode **rvp) 2053 { 2054 2055 return (vn_vget_ino_gen(vp, vn_get_ino_alloc_vget, &ino, 2056 lkflags, rvp)); 2057 } 2058 2059 int 2060 vn_vget_ino_gen(struct vnode *vp, vn_get_ino_t alloc, void *alloc_arg, 2061 int lkflags, struct vnode **rvp) 2062 { 2063 struct mount *mp; 2064 int ltype, error; 2065 2066 ASSERT_VOP_LOCKED(vp, "vn_vget_ino_get"); 2067 mp = vp->v_mount; 2068 ltype = VOP_ISLOCKED(vp); 2069 KASSERT(ltype == LK_EXCLUSIVE || ltype == LK_SHARED, 2070 ("vn_vget_ino: vp not locked")); 2071 error = vfs_busy(mp, MBF_NOWAIT); 2072 if (error != 0) { 2073 vfs_ref(mp); 2074 VOP_UNLOCK(vp, 0); 2075 error = vfs_busy(mp, 0); 2076 vn_lock(vp, ltype | LK_RETRY); 2077 vfs_rel(mp); 2078 if (error != 0) 2079 return (ENOENT); 2080 if (vp->v_iflag & VI_DOOMED) { 2081 vfs_unbusy(mp); 2082 return (ENOENT); 2083 } 2084 } 2085 VOP_UNLOCK(vp, 0); 2086 error = alloc(mp, alloc_arg, lkflags, rvp); 2087 vfs_unbusy(mp); 2088 if (error != 0 || *rvp != vp) 2089 vn_lock(vp, ltype | LK_RETRY); 2090 if (vp->v_iflag & VI_DOOMED) { 2091 if (error == 0) { 2092 if (*rvp == vp) 2093 vunref(vp); 2094 else 2095 vput(*rvp); 2096 } 2097 error = ENOENT; 2098 } 2099 return (error); 2100 } 2101 2102 int 2103 vn_rlimit_fsize(const struct vnode *vp, const struct uio *uio, 2104 struct thread *td) 2105 { 2106 2107 if (vp->v_type != VREG || td == NULL) 2108 return (0); 2109 if ((uoff_t)uio->uio_offset + uio->uio_resid > 2110 lim_cur(td, RLIMIT_FSIZE)) { 2111 PROC_LOCK(td->td_proc); 2112 kern_psignal(td->td_proc, SIGXFSZ); 2113 PROC_UNLOCK(td->td_proc); 2114 return (EFBIG); 2115 } 2116 return (0); 2117 } 2118 2119 int 2120 vn_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 2121 struct thread *td) 2122 { 2123 struct vnode *vp; 2124 2125 vp = fp->f_vnode; 2126 #ifdef AUDIT 2127 vn_lock(vp, LK_SHARED | LK_RETRY); 2128 AUDIT_ARG_VNODE1(vp); 2129 VOP_UNLOCK(vp, 0); 2130 #endif 2131 return (setfmode(td, active_cred, vp, mode)); 2132 } 2133 2134 int 2135 vn_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 2136 struct thread *td) 2137 { 2138 struct vnode *vp; 2139 2140 vp = fp->f_vnode; 2141 #ifdef AUDIT 2142 vn_lock(vp, LK_SHARED | LK_RETRY); 2143 AUDIT_ARG_VNODE1(vp); 2144 VOP_UNLOCK(vp, 0); 2145 #endif 2146 return (setfown(td, active_cred, vp, uid, gid)); 2147 } 2148 2149 void 2150 vn_pages_remove(struct vnode *vp, vm_pindex_t start, vm_pindex_t end) 2151 { 2152 vm_object_t object; 2153 2154 if ((object = vp->v_object) == NULL) 2155 return; 2156 VM_OBJECT_WLOCK(object); 2157 vm_object_page_remove(object, start, end, 0); 2158 VM_OBJECT_WUNLOCK(object); 2159 } 2160 2161 int 2162 vn_bmap_seekhole(struct vnode *vp, u_long cmd, off_t *off, struct ucred *cred) 2163 { 2164 struct vattr va; 2165 daddr_t bn, bnp; 2166 uint64_t bsize; 2167 off_t noff; 2168 int error; 2169 2170 KASSERT(cmd == FIOSEEKHOLE || cmd == FIOSEEKDATA, 2171 ("Wrong command %lu", cmd)); 2172 2173 if (vn_lock(vp, LK_SHARED) != 0) 2174 return (EBADF); 2175 if (vp->v_type != VREG) { 2176 error = ENOTTY; 2177 goto unlock; 2178 } 2179 error = VOP_GETATTR(vp, &va, cred); 2180 if (error != 0) 2181 goto unlock; 2182 noff = *off; 2183 if (noff >= va.va_size) { 2184 error = ENXIO; 2185 goto unlock; 2186 } 2187 bsize = vp->v_mount->mnt_stat.f_iosize; 2188 for (bn = noff / bsize; noff < va.va_size; bn++, noff += bsize - 2189 noff % bsize) { 2190 error = VOP_BMAP(vp, bn, NULL, &bnp, NULL, NULL); 2191 if (error == EOPNOTSUPP) { 2192 error = ENOTTY; 2193 goto unlock; 2194 } 2195 if ((bnp == -1 && cmd == FIOSEEKHOLE) || 2196 (bnp != -1 && cmd == FIOSEEKDATA)) { 2197 noff = bn * bsize; 2198 if (noff < *off) 2199 noff = *off; 2200 goto unlock; 2201 } 2202 } 2203 if (noff > va.va_size) 2204 noff = va.va_size; 2205 /* noff == va.va_size. There is an implicit hole at the end of file. */ 2206 if (cmd == FIOSEEKDATA) 2207 error = ENXIO; 2208 unlock: 2209 VOP_UNLOCK(vp, 0); 2210 if (error == 0) 2211 *off = noff; 2212 return (error); 2213 } 2214 2215 int 2216 vn_seek(struct file *fp, off_t offset, int whence, struct thread *td) 2217 { 2218 struct ucred *cred; 2219 struct vnode *vp; 2220 struct vattr vattr; 2221 off_t foffset, size; 2222 int error, noneg; 2223 2224 cred = td->td_ucred; 2225 vp = fp->f_vnode; 2226 foffset = foffset_lock(fp, 0); 2227 noneg = (vp->v_type != VCHR); 2228 error = 0; 2229 switch (whence) { 2230 case L_INCR: 2231 if (noneg && 2232 (foffset < 0 || 2233 (offset > 0 && foffset > OFF_MAX - offset))) { 2234 error = EOVERFLOW; 2235 break; 2236 } 2237 offset += foffset; 2238 break; 2239 case L_XTND: 2240 vn_lock(vp, LK_SHARED | LK_RETRY); 2241 error = VOP_GETATTR(vp, &vattr, cred); 2242 VOP_UNLOCK(vp, 0); 2243 if (error) 2244 break; 2245 2246 /* 2247 * If the file references a disk device, then fetch 2248 * the media size and use that to determine the ending 2249 * offset. 2250 */ 2251 if (vattr.va_size == 0 && vp->v_type == VCHR && 2252 fo_ioctl(fp, DIOCGMEDIASIZE, &size, cred, td) == 0) 2253 vattr.va_size = size; 2254 if (noneg && 2255 (vattr.va_size > OFF_MAX || 2256 (offset > 0 && vattr.va_size > OFF_MAX - offset))) { 2257 error = EOVERFLOW; 2258 break; 2259 } 2260 offset += vattr.va_size; 2261 break; 2262 case L_SET: 2263 break; 2264 case SEEK_DATA: 2265 error = fo_ioctl(fp, FIOSEEKDATA, &offset, cred, td); 2266 break; 2267 case SEEK_HOLE: 2268 error = fo_ioctl(fp, FIOSEEKHOLE, &offset, cred, td); 2269 break; 2270 default: 2271 error = EINVAL; 2272 } 2273 if (error == 0 && noneg && offset < 0) 2274 error = EINVAL; 2275 if (error != 0) 2276 goto drop; 2277 VFS_KNOTE_UNLOCKED(vp, 0); 2278 td->td_uretoff.tdu_off = offset; 2279 drop: 2280 foffset_unlock(fp, offset, error != 0 ? FOF_NOUPDATE : 0); 2281 return (error); 2282 } 2283 2284 int 2285 vn_utimes_perm(struct vnode *vp, struct vattr *vap, struct ucred *cred, 2286 struct thread *td) 2287 { 2288 int error; 2289 2290 /* 2291 * Grant permission if the caller is the owner of the file, or 2292 * the super-user, or has ACL_WRITE_ATTRIBUTES permission on 2293 * on the file. If the time pointer is null, then write 2294 * permission on the file is also sufficient. 2295 * 2296 * From NFSv4.1, draft 21, 6.2.1.3.1, Discussion of Mask Attributes: 2297 * A user having ACL_WRITE_DATA or ACL_WRITE_ATTRIBUTES 2298 * will be allowed to set the times [..] to the current 2299 * server time. 2300 */ 2301 error = VOP_ACCESSX(vp, VWRITE_ATTRIBUTES, cred, td); 2302 if (error != 0 && (vap->va_vaflags & VA_UTIMES_NULL) != 0) 2303 error = VOP_ACCESS(vp, VWRITE, cred, td); 2304 return (error); 2305 } 2306 2307 int 2308 vn_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 2309 { 2310 struct vnode *vp; 2311 int error; 2312 2313 if (fp->f_type == DTYPE_FIFO) 2314 kif->kf_type = KF_TYPE_FIFO; 2315 else 2316 kif->kf_type = KF_TYPE_VNODE; 2317 vp = fp->f_vnode; 2318 vref(vp); 2319 FILEDESC_SUNLOCK(fdp); 2320 error = vn_fill_kinfo_vnode(vp, kif); 2321 vrele(vp); 2322 FILEDESC_SLOCK(fdp); 2323 return (error); 2324 } 2325 2326 static inline void 2327 vn_fill_junk(struct kinfo_file *kif) 2328 { 2329 size_t len, olen; 2330 2331 /* 2332 * Simulate vn_fullpath returning changing values for a given 2333 * vp during e.g. coredump. 2334 */ 2335 len = (arc4random() % (sizeof(kif->kf_path) - 2)) + 1; 2336 olen = strlen(kif->kf_path); 2337 if (len < olen) 2338 strcpy(&kif->kf_path[len - 1], "$"); 2339 else 2340 for (; olen < len; olen++) 2341 strcpy(&kif->kf_path[olen], "A"); 2342 } 2343 2344 int 2345 vn_fill_kinfo_vnode(struct vnode *vp, struct kinfo_file *kif) 2346 { 2347 struct vattr va; 2348 char *fullpath, *freepath; 2349 int error; 2350 2351 kif->kf_vnode_type = vntype_to_kinfo(vp->v_type); 2352 freepath = NULL; 2353 fullpath = "-"; 2354 error = vn_fullpath(curthread, vp, &fullpath, &freepath); 2355 if (error == 0) { 2356 strlcpy(kif->kf_path, fullpath, sizeof(kif->kf_path)); 2357 } 2358 if (freepath != NULL) 2359 free(freepath, M_TEMP); 2360 2361 KFAIL_POINT_CODE(DEBUG_FP, fill_kinfo_vnode__random_path, 2362 vn_fill_junk(kif); 2363 ); 2364 2365 /* 2366 * Retrieve vnode attributes. 2367 */ 2368 va.va_fsid = VNOVAL; 2369 va.va_rdev = NODEV; 2370 vn_lock(vp, LK_SHARED | LK_RETRY); 2371 error = VOP_GETATTR(vp, &va, curthread->td_ucred); 2372 VOP_UNLOCK(vp, 0); 2373 if (error != 0) 2374 return (error); 2375 if (va.va_fsid != VNOVAL) 2376 kif->kf_un.kf_file.kf_file_fsid = va.va_fsid; 2377 else 2378 kif->kf_un.kf_file.kf_file_fsid = 2379 vp->v_mount->mnt_stat.f_fsid.val[0]; 2380 kif->kf_un.kf_file.kf_file_fileid = va.va_fileid; 2381 kif->kf_un.kf_file.kf_file_mode = MAKEIMODE(va.va_type, va.va_mode); 2382 kif->kf_un.kf_file.kf_file_size = va.va_size; 2383 kif->kf_un.kf_file.kf_file_rdev = va.va_rdev; 2384 return (0); 2385 } 2386 2387 int 2388 vn_mmap(struct file *fp, vm_map_t map, vm_offset_t *addr, vm_size_t size, 2389 vm_prot_t prot, vm_prot_t cap_maxprot, int flags, vm_ooffset_t foff, 2390 struct thread *td) 2391 { 2392 #ifdef HWPMC_HOOKS 2393 struct pmckern_map_in pkm; 2394 #endif 2395 struct mount *mp; 2396 struct vnode *vp; 2397 vm_object_t object; 2398 vm_prot_t maxprot; 2399 boolean_t writecounted; 2400 int error; 2401 2402 #if defined(COMPAT_FREEBSD7) || defined(COMPAT_FREEBSD6) || \ 2403 defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4) 2404 /* 2405 * POSIX shared-memory objects are defined to have 2406 * kernel persistence, and are not defined to support 2407 * read(2)/write(2) -- or even open(2). Thus, we can 2408 * use MAP_ASYNC to trade on-disk coherence for speed. 2409 * The shm_open(3) library routine turns on the FPOSIXSHM 2410 * flag to request this behavior. 2411 */ 2412 if ((fp->f_flag & FPOSIXSHM) != 0) 2413 flags |= MAP_NOSYNC; 2414 #endif 2415 vp = fp->f_vnode; 2416 2417 /* 2418 * Ensure that file and memory protections are 2419 * compatible. Note that we only worry about 2420 * writability if mapping is shared; in this case, 2421 * current and max prot are dictated by the open file. 2422 * XXX use the vnode instead? Problem is: what 2423 * credentials do we use for determination? What if 2424 * proc does a setuid? 2425 */ 2426 mp = vp->v_mount; 2427 if (mp != NULL && (mp->mnt_flag & MNT_NOEXEC) != 0) { 2428 maxprot = VM_PROT_NONE; 2429 if ((prot & VM_PROT_EXECUTE) != 0) 2430 return (EACCES); 2431 } else 2432 maxprot = VM_PROT_EXECUTE; 2433 if ((fp->f_flag & FREAD) != 0) 2434 maxprot |= VM_PROT_READ; 2435 else if ((prot & VM_PROT_READ) != 0) 2436 return (EACCES); 2437 2438 /* 2439 * If we are sharing potential changes via MAP_SHARED and we 2440 * are trying to get write permission although we opened it 2441 * without asking for it, bail out. 2442 */ 2443 if ((flags & MAP_SHARED) != 0) { 2444 if ((fp->f_flag & FWRITE) != 0) 2445 maxprot |= VM_PROT_WRITE; 2446 else if ((prot & VM_PROT_WRITE) != 0) 2447 return (EACCES); 2448 } else { 2449 maxprot |= VM_PROT_WRITE; 2450 cap_maxprot |= VM_PROT_WRITE; 2451 } 2452 maxprot &= cap_maxprot; 2453 2454 /* 2455 * For regular files and shared memory, POSIX requires that 2456 * the value of foff be a legitimate offset within the data 2457 * object. In particular, negative offsets are invalid. 2458 * Blocking negative offsets and overflows here avoids 2459 * possible wraparound or user-level access into reserved 2460 * ranges of the data object later. In contrast, POSIX does 2461 * not dictate how offsets are used by device drivers, so in 2462 * the case of a device mapping a negative offset is passed 2463 * on. 2464 */ 2465 if ( 2466 #ifdef _LP64 2467 size > OFF_MAX || 2468 #endif 2469 foff < 0 || foff > OFF_MAX - size) 2470 return (EINVAL); 2471 2472 writecounted = FALSE; 2473 error = vm_mmap_vnode(td, size, prot, &maxprot, &flags, vp, 2474 &foff, &object, &writecounted); 2475 if (error != 0) 2476 return (error); 2477 error = vm_mmap_object(map, addr, size, prot, maxprot, flags, object, 2478 foff, writecounted, td); 2479 if (error != 0) { 2480 /* 2481 * If this mapping was accounted for in the vnode's 2482 * writecount, then undo that now. 2483 */ 2484 if (writecounted) 2485 vnode_pager_release_writecount(object, 0, size); 2486 vm_object_deallocate(object); 2487 } 2488 #ifdef HWPMC_HOOKS 2489 /* Inform hwpmc(4) if an executable is being mapped. */ 2490 if (PMC_HOOK_INSTALLED(PMC_FN_MMAP)) { 2491 if ((prot & VM_PROT_EXECUTE) != 0 && error == 0) { 2492 pkm.pm_file = vp; 2493 pkm.pm_address = (uintptr_t) *addr; 2494 PMC_CALL_HOOK(td, PMC_FN_MMAP, (void *) &pkm); 2495 } 2496 } 2497 #endif 2498 return (error); 2499 }
Cache object: 22f38b095491e4d5275b69bc09fe5de6
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