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FreeBSD/Linux Kernel Cross Reference
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: releng/11.2/sys/kern/vfs_vnops.c 338606 2018-09-12 05:07:35Z gordon $"); 45 46 #include "opt_hwpmc_hooks.h" 47 48 #include <sys/param.h> 49 #include <sys/systm.h> 50 #include <sys/disk.h> 51 #include <sys/fail.h> 52 #include <sys/fcntl.h> 53 #include <sys/file.h> 54 #include <sys/kdb.h> 55 #include <sys/stat.h> 56 #include <sys/priv.h> 57 #include <sys/proc.h> 58 #include <sys/limits.h> 59 #include <sys/lock.h> 60 #include <sys/mman.h> 61 #include <sys/mount.h> 62 #include <sys/mutex.h> 63 #include <sys/namei.h> 64 #include <sys/vnode.h> 65 #include <sys/bio.h> 66 #include <sys/buf.h> 67 #include <sys/filio.h> 68 #include <sys/resourcevar.h> 69 #include <sys/rwlock.h> 70 #include <sys/sx.h> 71 #include <sys/sysctl.h> 72 #include <sys/ttycom.h> 73 #include <sys/conf.h> 74 #include <sys/syslog.h> 75 #include <sys/unistd.h> 76 #include <sys/user.h> 77 78 #include <security/audit/audit.h> 79 #include <security/mac/mac_framework.h> 80 81 #include <vm/vm.h> 82 #include <vm/vm_extern.h> 83 #include <vm/pmap.h> 84 #include <vm/vm_map.h> 85 #include <vm/vm_object.h> 86 #include <vm/vm_page.h> 87 #include <vm/vnode_pager.h> 88 89 #ifdef HWPMC_HOOKS 90 #include <sys/pmckern.h> 91 #endif 92 93 static fo_rdwr_t vn_read; 94 static fo_rdwr_t vn_write; 95 static fo_rdwr_t vn_io_fault; 96 static fo_truncate_t vn_truncate; 97 static fo_ioctl_t vn_ioctl; 98 static fo_poll_t vn_poll; 99 static fo_kqfilter_t vn_kqfilter; 100 static fo_stat_t vn_statfile; 101 static fo_close_t vn_closefile; 102 static fo_mmap_t vn_mmap; 103 104 struct fileops vnops = { 105 .fo_read = vn_io_fault, 106 .fo_write = vn_io_fault, 107 .fo_truncate = vn_truncate, 108 .fo_ioctl = vn_ioctl, 109 .fo_poll = vn_poll, 110 .fo_kqfilter = vn_kqfilter, 111 .fo_stat = vn_statfile, 112 .fo_close = vn_closefile, 113 .fo_chmod = vn_chmod, 114 .fo_chown = vn_chown, 115 .fo_sendfile = vn_sendfile, 116 .fo_seek = vn_seek, 117 .fo_fill_kinfo = vn_fill_kinfo, 118 .fo_mmap = vn_mmap, 119 .fo_flags = DFLAG_PASSABLE | DFLAG_SEEKABLE 120 }; 121 122 static const int io_hold_cnt = 16; 123 static int vn_io_fault_enable = 1; 124 SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_enable, CTLFLAG_RW, 125 &vn_io_fault_enable, 0, "Enable vn_io_fault lock avoidance"); 126 static int vn_io_fault_prefault = 0; 127 SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_prefault, CTLFLAG_RW, 128 &vn_io_fault_prefault, 0, "Enable vn_io_fault prefaulting"); 129 static u_long vn_io_faults_cnt; 130 SYSCTL_ULONG(_debug, OID_AUTO, vn_io_faults, CTLFLAG_RD, 131 &vn_io_faults_cnt, 0, "Count of vn_io_fault lock avoidance triggers"); 132 133 /* 134 * Returns true if vn_io_fault mode of handling the i/o request should 135 * be used. 136 */ 137 static bool 138 do_vn_io_fault(struct vnode *vp, struct uio *uio) 139 { 140 struct mount *mp; 141 142 return (uio->uio_segflg == UIO_USERSPACE && vp->v_type == VREG && 143 (mp = vp->v_mount) != NULL && 144 (mp->mnt_kern_flag & MNTK_NO_IOPF) != 0 && vn_io_fault_enable); 145 } 146 147 /* 148 * Structure used to pass arguments to vn_io_fault1(), to do either 149 * file- or vnode-based I/O calls. 150 */ 151 struct vn_io_fault_args { 152 enum { 153 VN_IO_FAULT_FOP, 154 VN_IO_FAULT_VOP 155 } kind; 156 struct ucred *cred; 157 int flags; 158 union { 159 struct fop_args_tag { 160 struct file *fp; 161 fo_rdwr_t *doio; 162 } fop_args; 163 struct vop_args_tag { 164 struct vnode *vp; 165 } vop_args; 166 } args; 167 }; 168 169 static int vn_io_fault1(struct vnode *vp, struct uio *uio, 170 struct vn_io_fault_args *args, struct thread *td); 171 172 int 173 vn_open(ndp, flagp, cmode, fp) 174 struct nameidata *ndp; 175 int *flagp, cmode; 176 struct file *fp; 177 { 178 struct thread *td = ndp->ni_cnd.cn_thread; 179 180 return (vn_open_cred(ndp, flagp, cmode, 0, td->td_ucred, fp)); 181 } 182 183 /* 184 * Common code for vnode open operations via a name lookup. 185 * Lookup the vnode and invoke VOP_CREATE if needed. 186 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine. 187 * 188 * Note that this does NOT free nameidata for the successful case, 189 * due to the NDINIT being done elsewhere. 190 */ 191 int 192 vn_open_cred(struct nameidata *ndp, int *flagp, int cmode, u_int vn_open_flags, 193 struct ucred *cred, struct file *fp) 194 { 195 struct vnode *vp; 196 struct mount *mp; 197 struct thread *td = ndp->ni_cnd.cn_thread; 198 struct vattr vat; 199 struct vattr *vap = &vat; 200 int fmode, error; 201 202 restart: 203 fmode = *flagp; 204 if ((fmode & (O_CREAT | O_EXCL | O_DIRECTORY)) == (O_CREAT | 205 O_EXCL | O_DIRECTORY)) 206 return (EINVAL); 207 else if ((fmode & (O_CREAT | O_DIRECTORY)) == O_CREAT) { 208 ndp->ni_cnd.cn_nameiop = CREATE; 209 /* 210 * Set NOCACHE to avoid flushing the cache when 211 * rolling in many files at once. 212 */ 213 ndp->ni_cnd.cn_flags = ISOPEN | LOCKPARENT | LOCKLEAF | NOCACHE; 214 if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0) 215 ndp->ni_cnd.cn_flags |= FOLLOW; 216 if (!(vn_open_flags & VN_OPEN_NOAUDIT)) 217 ndp->ni_cnd.cn_flags |= AUDITVNODE1; 218 if (vn_open_flags & VN_OPEN_NOCAPCHECK) 219 ndp->ni_cnd.cn_flags |= NOCAPCHECK; 220 bwillwrite(); 221 if ((error = namei(ndp)) != 0) 222 return (error); 223 if (ndp->ni_vp == NULL) { 224 VATTR_NULL(vap); 225 vap->va_type = VREG; 226 vap->va_mode = cmode; 227 if (fmode & O_EXCL) 228 vap->va_vaflags |= VA_EXCLUSIVE; 229 if (vn_start_write(ndp->ni_dvp, &mp, V_NOWAIT) != 0) { 230 NDFREE(ndp, NDF_ONLY_PNBUF); 231 vput(ndp->ni_dvp); 232 if ((error = vn_start_write(NULL, &mp, 233 V_XSLEEP | PCATCH)) != 0) 234 return (error); 235 goto restart; 236 } 237 if ((vn_open_flags & VN_OPEN_NAMECACHE) != 0) 238 ndp->ni_cnd.cn_flags |= MAKEENTRY; 239 #ifdef MAC 240 error = mac_vnode_check_create(cred, ndp->ni_dvp, 241 &ndp->ni_cnd, vap); 242 if (error == 0) 243 #endif 244 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp, 245 &ndp->ni_cnd, vap); 246 vput(ndp->ni_dvp); 247 vn_finished_write(mp); 248 if (error) { 249 NDFREE(ndp, NDF_ONLY_PNBUF); 250 return (error); 251 } 252 fmode &= ~O_TRUNC; 253 vp = ndp->ni_vp; 254 } else { 255 if (ndp->ni_dvp == ndp->ni_vp) 256 vrele(ndp->ni_dvp); 257 else 258 vput(ndp->ni_dvp); 259 ndp->ni_dvp = NULL; 260 vp = ndp->ni_vp; 261 if (fmode & O_EXCL) { 262 error = EEXIST; 263 goto bad; 264 } 265 fmode &= ~O_CREAT; 266 } 267 } else { 268 ndp->ni_cnd.cn_nameiop = LOOKUP; 269 ndp->ni_cnd.cn_flags = ISOPEN | 270 ((fmode & O_NOFOLLOW) ? NOFOLLOW : FOLLOW) | LOCKLEAF; 271 if (!(fmode & FWRITE)) 272 ndp->ni_cnd.cn_flags |= LOCKSHARED; 273 if (!(vn_open_flags & VN_OPEN_NOAUDIT)) 274 ndp->ni_cnd.cn_flags |= AUDITVNODE1; 275 if (vn_open_flags & VN_OPEN_NOCAPCHECK) 276 ndp->ni_cnd.cn_flags |= NOCAPCHECK; 277 if ((error = namei(ndp)) != 0) 278 return (error); 279 vp = ndp->ni_vp; 280 } 281 error = vn_open_vnode(vp, fmode, cred, td, fp); 282 if (error) 283 goto bad; 284 *flagp = fmode; 285 return (0); 286 bad: 287 NDFREE(ndp, NDF_ONLY_PNBUF); 288 vput(vp); 289 *flagp = fmode; 290 ndp->ni_vp = NULL; 291 return (error); 292 } 293 294 /* 295 * Common code for vnode open operations once a vnode is located. 296 * Check permissions, and call the VOP_OPEN routine. 297 */ 298 int 299 vn_open_vnode(struct vnode *vp, int fmode, struct ucred *cred, 300 struct thread *td, struct file *fp) 301 { 302 accmode_t accmode; 303 struct flock lf; 304 int error, lock_flags, type; 305 306 if (vp->v_type == VLNK) 307 return (EMLINK); 308 if (vp->v_type == VSOCK) 309 return (EOPNOTSUPP); 310 if (vp->v_type != VDIR && fmode & O_DIRECTORY) 311 return (ENOTDIR); 312 accmode = 0; 313 if (fmode & (FWRITE | O_TRUNC)) { 314 if (vp->v_type == VDIR) 315 return (EISDIR); 316 accmode |= VWRITE; 317 } 318 if (fmode & FREAD) 319 accmode |= VREAD; 320 if (fmode & FEXEC) 321 accmode |= VEXEC; 322 if ((fmode & O_APPEND) && (fmode & FWRITE)) 323 accmode |= VAPPEND; 324 #ifdef MAC 325 if (fmode & O_CREAT) 326 accmode |= VCREAT; 327 if (fmode & O_VERIFY) 328 accmode |= VVERIFY; 329 error = mac_vnode_check_open(cred, vp, accmode); 330 if (error) 331 return (error); 332 333 accmode &= ~(VCREAT | VVERIFY); 334 #endif 335 if ((fmode & O_CREAT) == 0) { 336 if (accmode & VWRITE) { 337 error = vn_writechk(vp); 338 if (error) 339 return (error); 340 } 341 if (accmode) { 342 error = VOP_ACCESS(vp, accmode, cred, td); 343 if (error) 344 return (error); 345 } 346 } 347 if (vp->v_type == VFIFO && VOP_ISLOCKED(vp) != LK_EXCLUSIVE) 348 vn_lock(vp, LK_UPGRADE | LK_RETRY); 349 if ((error = VOP_OPEN(vp, fmode, cred, td, fp)) != 0) 350 return (error); 351 352 while ((fmode & (O_EXLOCK | O_SHLOCK)) != 0) { 353 KASSERT(fp != NULL, ("open with flock requires fp")); 354 if (fp->f_type != DTYPE_NONE && fp->f_type != DTYPE_VNODE) { 355 error = EOPNOTSUPP; 356 break; 357 } 358 lock_flags = VOP_ISLOCKED(vp); 359 VOP_UNLOCK(vp, 0); 360 lf.l_whence = SEEK_SET; 361 lf.l_start = 0; 362 lf.l_len = 0; 363 if (fmode & O_EXLOCK) 364 lf.l_type = F_WRLCK; 365 else 366 lf.l_type = F_RDLCK; 367 type = F_FLOCK; 368 if ((fmode & FNONBLOCK) == 0) 369 type |= F_WAIT; 370 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, type); 371 if (error == 0) 372 fp->f_flag |= FHASLOCK; 373 vn_lock(vp, lock_flags | LK_RETRY); 374 if (error != 0) 375 break; 376 if ((vp->v_iflag & VI_DOOMED) != 0) { 377 error = ENOENT; 378 break; 379 } 380 381 /* 382 * Another thread might have used this vnode as an 383 * executable while the vnode lock was dropped. 384 * Ensure the vnode is still able to be opened for 385 * writing after the lock has been obtained. 386 */ 387 if ((accmode & VWRITE) != 0) 388 error = vn_writechk(vp); 389 break; 390 } 391 392 if (error != 0) { 393 fp->f_flag |= FOPENFAILED; 394 fp->f_vnode = vp; 395 if (fp->f_ops == &badfileops) { 396 fp->f_type = DTYPE_VNODE; 397 fp->f_ops = &vnops; 398 } 399 vref(vp); 400 } else if ((fmode & FWRITE) != 0) { 401 VOP_ADD_WRITECOUNT(vp, 1); 402 CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d", 403 __func__, vp, vp->v_writecount); 404 } 405 ASSERT_VOP_LOCKED(vp, "vn_open_vnode"); 406 return (error); 407 } 408 409 /* 410 * Check for write permissions on the specified vnode. 411 * Prototype text segments cannot be written. 412 */ 413 int 414 vn_writechk(struct vnode *vp) 415 { 416 417 ASSERT_VOP_LOCKED(vp, "vn_writechk"); 418 /* 419 * If there's shared text associated with 420 * the vnode, try to free it up once. If 421 * we fail, we can't allow writing. 422 */ 423 if (VOP_IS_TEXT(vp)) 424 return (ETXTBSY); 425 426 return (0); 427 } 428 429 /* 430 * Vnode close call 431 */ 432 static int 433 vn_close1(struct vnode *vp, int flags, struct ucred *file_cred, 434 struct thread *td, bool keep_ref) 435 { 436 struct mount *mp; 437 int error, lock_flags; 438 439 if (vp->v_type != VFIFO && (flags & FWRITE) == 0 && 440 MNT_EXTENDED_SHARED(vp->v_mount)) 441 lock_flags = LK_SHARED; 442 else 443 lock_flags = LK_EXCLUSIVE; 444 445 vn_start_write(vp, &mp, V_WAIT); 446 vn_lock(vp, lock_flags | LK_RETRY); 447 AUDIT_ARG_VNODE1(vp); 448 if ((flags & (FWRITE | FOPENFAILED)) == FWRITE) { 449 VNASSERT(vp->v_writecount > 0, vp, 450 ("vn_close: negative writecount")); 451 VOP_ADD_WRITECOUNT(vp, -1); 452 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d", 453 __func__, vp, vp->v_writecount); 454 } 455 error = VOP_CLOSE(vp, flags, file_cred, td); 456 if (keep_ref) 457 VOP_UNLOCK(vp, 0); 458 else 459 vput(vp); 460 vn_finished_write(mp); 461 return (error); 462 } 463 464 int 465 vn_close(struct vnode *vp, int flags, struct ucred *file_cred, 466 struct thread *td) 467 { 468 469 return (vn_close1(vp, flags, file_cred, td, false)); 470 } 471 472 /* 473 * Heuristic to detect sequential operation. 474 */ 475 static int 476 sequential_heuristic(struct uio *uio, struct file *fp) 477 { 478 479 ASSERT_VOP_LOCKED(fp->f_vnode, __func__); 480 if (fp->f_flag & FRDAHEAD) 481 return (fp->f_seqcount << IO_SEQSHIFT); 482 483 /* 484 * Offset 0 is handled specially. open() sets f_seqcount to 1 so 485 * that the first I/O is normally considered to be slightly 486 * sequential. Seeking to offset 0 doesn't change sequentiality 487 * unless previous seeks have reduced f_seqcount to 0, in which 488 * case offset 0 is not special. 489 */ 490 if ((uio->uio_offset == 0 && fp->f_seqcount > 0) || 491 uio->uio_offset == fp->f_nextoff) { 492 /* 493 * f_seqcount is in units of fixed-size blocks so that it 494 * depends mainly on the amount of sequential I/O and not 495 * much on the number of sequential I/O's. The fixed size 496 * of 16384 is hard-coded here since it is (not quite) just 497 * a magic size that works well here. This size is more 498 * closely related to the best I/O size for real disks than 499 * to any block size used by software. 500 */ 501 fp->f_seqcount += howmany(uio->uio_resid, 16384); 502 if (fp->f_seqcount > IO_SEQMAX) 503 fp->f_seqcount = IO_SEQMAX; 504 return (fp->f_seqcount << IO_SEQSHIFT); 505 } 506 507 /* Not sequential. Quickly draw-down sequentiality. */ 508 if (fp->f_seqcount > 1) 509 fp->f_seqcount = 1; 510 else 511 fp->f_seqcount = 0; 512 return (0); 513 } 514 515 /* 516 * Package up an I/O request on a vnode into a uio and do it. 517 */ 518 int 519 vn_rdwr(enum uio_rw rw, struct vnode *vp, void *base, int len, off_t offset, 520 enum uio_seg segflg, int ioflg, struct ucred *active_cred, 521 struct ucred *file_cred, ssize_t *aresid, struct thread *td) 522 { 523 struct uio auio; 524 struct iovec aiov; 525 struct mount *mp; 526 struct ucred *cred; 527 void *rl_cookie; 528 struct vn_io_fault_args args; 529 int error, lock_flags; 530 531 if (offset < 0 && vp->v_type != VCHR) 532 return (EINVAL); 533 auio.uio_iov = &aiov; 534 auio.uio_iovcnt = 1; 535 aiov.iov_base = base; 536 aiov.iov_len = len; 537 auio.uio_resid = len; 538 auio.uio_offset = offset; 539 auio.uio_segflg = segflg; 540 auio.uio_rw = rw; 541 auio.uio_td = td; 542 error = 0; 543 544 if ((ioflg & IO_NODELOCKED) == 0) { 545 if ((ioflg & IO_RANGELOCKED) == 0) { 546 if (rw == UIO_READ) { 547 rl_cookie = vn_rangelock_rlock(vp, offset, 548 offset + len); 549 } else { 550 rl_cookie = vn_rangelock_wlock(vp, offset, 551 offset + len); 552 } 553 } else 554 rl_cookie = NULL; 555 mp = NULL; 556 if (rw == UIO_WRITE) { 557 if (vp->v_type != VCHR && 558 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) 559 != 0) 560 goto out; 561 if (MNT_SHARED_WRITES(mp) || 562 ((mp == NULL) && MNT_SHARED_WRITES(vp->v_mount))) 563 lock_flags = LK_SHARED; 564 else 565 lock_flags = LK_EXCLUSIVE; 566 } else 567 lock_flags = LK_SHARED; 568 vn_lock(vp, lock_flags | LK_RETRY); 569 } else 570 rl_cookie = NULL; 571 572 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 573 #ifdef MAC 574 if ((ioflg & IO_NOMACCHECK) == 0) { 575 if (rw == UIO_READ) 576 error = mac_vnode_check_read(active_cred, file_cred, 577 vp); 578 else 579 error = mac_vnode_check_write(active_cred, file_cred, 580 vp); 581 } 582 #endif 583 if (error == 0) { 584 if (file_cred != NULL) 585 cred = file_cred; 586 else 587 cred = active_cred; 588 if (do_vn_io_fault(vp, &auio)) { 589 args.kind = VN_IO_FAULT_VOP; 590 args.cred = cred; 591 args.flags = ioflg; 592 args.args.vop_args.vp = vp; 593 error = vn_io_fault1(vp, &auio, &args, td); 594 } else if (rw == UIO_READ) { 595 error = VOP_READ(vp, &auio, ioflg, cred); 596 } else /* if (rw == UIO_WRITE) */ { 597 error = VOP_WRITE(vp, &auio, ioflg, cred); 598 } 599 } 600 if (aresid) 601 *aresid = auio.uio_resid; 602 else 603 if (auio.uio_resid && error == 0) 604 error = EIO; 605 if ((ioflg & IO_NODELOCKED) == 0) { 606 VOP_UNLOCK(vp, 0); 607 if (mp != NULL) 608 vn_finished_write(mp); 609 } 610 out: 611 if (rl_cookie != NULL) 612 vn_rangelock_unlock(vp, rl_cookie); 613 return (error); 614 } 615 616 /* 617 * Package up an I/O request on a vnode into a uio and do it. The I/O 618 * request is split up into smaller chunks and we try to avoid saturating 619 * the buffer cache while potentially holding a vnode locked, so we 620 * check bwillwrite() before calling vn_rdwr(). We also call kern_yield() 621 * to give other processes a chance to lock the vnode (either other processes 622 * core'ing the same binary, or unrelated processes scanning the directory). 623 */ 624 int 625 vn_rdwr_inchunks(rw, vp, base, len, offset, segflg, ioflg, active_cred, 626 file_cred, aresid, td) 627 enum uio_rw rw; 628 struct vnode *vp; 629 void *base; 630 size_t len; 631 off_t offset; 632 enum uio_seg segflg; 633 int ioflg; 634 struct ucred *active_cred; 635 struct ucred *file_cred; 636 size_t *aresid; 637 struct thread *td; 638 { 639 int error = 0; 640 ssize_t iaresid; 641 642 do { 643 int chunk; 644 645 /* 646 * Force `offset' to a multiple of MAXBSIZE except possibly 647 * for the first chunk, so that filesystems only need to 648 * write full blocks except possibly for the first and last 649 * chunks. 650 */ 651 chunk = MAXBSIZE - (uoff_t)offset % MAXBSIZE; 652 653 if (chunk > len) 654 chunk = len; 655 if (rw != UIO_READ && vp->v_type == VREG) 656 bwillwrite(); 657 iaresid = 0; 658 error = vn_rdwr(rw, vp, base, chunk, offset, segflg, 659 ioflg, active_cred, file_cred, &iaresid, td); 660 len -= chunk; /* aresid calc already includes length */ 661 if (error) 662 break; 663 offset += chunk; 664 base = (char *)base + chunk; 665 kern_yield(PRI_USER); 666 } while (len); 667 if (aresid) 668 *aresid = len + iaresid; 669 return (error); 670 } 671 672 off_t 673 foffset_lock(struct file *fp, int flags) 674 { 675 struct mtx *mtxp; 676 off_t res; 677 678 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed")); 679 680 #if OFF_MAX <= LONG_MAX 681 /* 682 * Caller only wants the current f_offset value. Assume that 683 * the long and shorter integer types reads are atomic. 684 */ 685 if ((flags & FOF_NOLOCK) != 0) 686 return (fp->f_offset); 687 #endif 688 689 /* 690 * According to McKusick the vn lock was protecting f_offset here. 691 * It is now protected by the FOFFSET_LOCKED flag. 692 */ 693 mtxp = mtx_pool_find(mtxpool_sleep, fp); 694 mtx_lock(mtxp); 695 if ((flags & FOF_NOLOCK) == 0) { 696 while (fp->f_vnread_flags & FOFFSET_LOCKED) { 697 fp->f_vnread_flags |= FOFFSET_LOCK_WAITING; 698 msleep(&fp->f_vnread_flags, mtxp, PUSER -1, 699 "vofflock", 0); 700 } 701 fp->f_vnread_flags |= FOFFSET_LOCKED; 702 } 703 res = fp->f_offset; 704 mtx_unlock(mtxp); 705 return (res); 706 } 707 708 void 709 foffset_unlock(struct file *fp, off_t val, int flags) 710 { 711 struct mtx *mtxp; 712 713 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed")); 714 715 #if OFF_MAX <= LONG_MAX 716 if ((flags & FOF_NOLOCK) != 0) { 717 if ((flags & FOF_NOUPDATE) == 0) 718 fp->f_offset = val; 719 if ((flags & FOF_NEXTOFF) != 0) 720 fp->f_nextoff = val; 721 return; 722 } 723 #endif 724 725 mtxp = mtx_pool_find(mtxpool_sleep, fp); 726 mtx_lock(mtxp); 727 if ((flags & FOF_NOUPDATE) == 0) 728 fp->f_offset = val; 729 if ((flags & FOF_NEXTOFF) != 0) 730 fp->f_nextoff = val; 731 if ((flags & FOF_NOLOCK) == 0) { 732 KASSERT((fp->f_vnread_flags & FOFFSET_LOCKED) != 0, 733 ("Lost FOFFSET_LOCKED")); 734 if (fp->f_vnread_flags & FOFFSET_LOCK_WAITING) 735 wakeup(&fp->f_vnread_flags); 736 fp->f_vnread_flags = 0; 737 } 738 mtx_unlock(mtxp); 739 } 740 741 void 742 foffset_lock_uio(struct file *fp, struct uio *uio, int flags) 743 { 744 745 if ((flags & FOF_OFFSET) == 0) 746 uio->uio_offset = foffset_lock(fp, flags); 747 } 748 749 void 750 foffset_unlock_uio(struct file *fp, struct uio *uio, int flags) 751 { 752 753 if ((flags & FOF_OFFSET) == 0) 754 foffset_unlock(fp, uio->uio_offset, flags); 755 } 756 757 static int 758 get_advice(struct file *fp, struct uio *uio) 759 { 760 struct mtx *mtxp; 761 int ret; 762 763 ret = POSIX_FADV_NORMAL; 764 if (fp->f_advice == NULL || fp->f_vnode->v_type != VREG) 765 return (ret); 766 767 mtxp = mtx_pool_find(mtxpool_sleep, fp); 768 mtx_lock(mtxp); 769 if (fp->f_advice != NULL && 770 uio->uio_offset >= fp->f_advice->fa_start && 771 uio->uio_offset + uio->uio_resid <= fp->f_advice->fa_end) 772 ret = fp->f_advice->fa_advice; 773 mtx_unlock(mtxp); 774 return (ret); 775 } 776 777 /* 778 * File table vnode read routine. 779 */ 780 static int 781 vn_read(fp, uio, active_cred, flags, td) 782 struct file *fp; 783 struct uio *uio; 784 struct ucred *active_cred; 785 int flags; 786 struct thread *td; 787 { 788 struct vnode *vp; 789 off_t orig_offset; 790 int error, ioflag; 791 int advice; 792 793 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", 794 uio->uio_td, td)); 795 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET")); 796 vp = fp->f_vnode; 797 ioflag = 0; 798 if (fp->f_flag & FNONBLOCK) 799 ioflag |= IO_NDELAY; 800 if (fp->f_flag & O_DIRECT) 801 ioflag |= IO_DIRECT; 802 advice = get_advice(fp, uio); 803 vn_lock(vp, LK_SHARED | LK_RETRY); 804 805 switch (advice) { 806 case POSIX_FADV_NORMAL: 807 case POSIX_FADV_SEQUENTIAL: 808 case POSIX_FADV_NOREUSE: 809 ioflag |= sequential_heuristic(uio, fp); 810 break; 811 case POSIX_FADV_RANDOM: 812 /* Disable read-ahead for random I/O. */ 813 break; 814 } 815 orig_offset = uio->uio_offset; 816 817 #ifdef MAC 818 error = mac_vnode_check_read(active_cred, fp->f_cred, vp); 819 if (error == 0) 820 #endif 821 error = VOP_READ(vp, uio, ioflag, fp->f_cred); 822 fp->f_nextoff = uio->uio_offset; 823 VOP_UNLOCK(vp, 0); 824 if (error == 0 && advice == POSIX_FADV_NOREUSE && 825 orig_offset != uio->uio_offset) 826 /* 827 * Use POSIX_FADV_DONTNEED to flush pages and buffers 828 * for the backing file after a POSIX_FADV_NOREUSE 829 * read(2). 830 */ 831 error = VOP_ADVISE(vp, orig_offset, uio->uio_offset - 1, 832 POSIX_FADV_DONTNEED); 833 return (error); 834 } 835 836 /* 837 * File table vnode write routine. 838 */ 839 static int 840 vn_write(fp, uio, active_cred, flags, td) 841 struct file *fp; 842 struct uio *uio; 843 struct ucred *active_cred; 844 int flags; 845 struct thread *td; 846 { 847 struct vnode *vp; 848 struct mount *mp; 849 off_t orig_offset; 850 int error, ioflag, lock_flags; 851 int advice; 852 853 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", 854 uio->uio_td, td)); 855 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET")); 856 vp = fp->f_vnode; 857 if (vp->v_type == VREG) 858 bwillwrite(); 859 ioflag = IO_UNIT; 860 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 861 ioflag |= IO_APPEND; 862 if (fp->f_flag & FNONBLOCK) 863 ioflag |= IO_NDELAY; 864 if (fp->f_flag & O_DIRECT) 865 ioflag |= IO_DIRECT; 866 if ((fp->f_flag & O_FSYNC) || 867 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS))) 868 ioflag |= IO_SYNC; 869 mp = NULL; 870 if (vp->v_type != VCHR && 871 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0) 872 goto unlock; 873 874 advice = get_advice(fp, uio); 875 876 if (MNT_SHARED_WRITES(mp) || 877 (mp == NULL && MNT_SHARED_WRITES(vp->v_mount))) { 878 lock_flags = LK_SHARED; 879 } else { 880 lock_flags = LK_EXCLUSIVE; 881 } 882 883 vn_lock(vp, lock_flags | LK_RETRY); 884 switch (advice) { 885 case POSIX_FADV_NORMAL: 886 case POSIX_FADV_SEQUENTIAL: 887 case POSIX_FADV_NOREUSE: 888 ioflag |= sequential_heuristic(uio, fp); 889 break; 890 case POSIX_FADV_RANDOM: 891 /* XXX: Is this correct? */ 892 break; 893 } 894 orig_offset = uio->uio_offset; 895 896 #ifdef MAC 897 error = mac_vnode_check_write(active_cred, fp->f_cred, vp); 898 if (error == 0) 899 #endif 900 error = VOP_WRITE(vp, uio, ioflag, fp->f_cred); 901 fp->f_nextoff = uio->uio_offset; 902 VOP_UNLOCK(vp, 0); 903 if (vp->v_type != VCHR) 904 vn_finished_write(mp); 905 if (error == 0 && advice == POSIX_FADV_NOREUSE && 906 orig_offset != uio->uio_offset) 907 /* 908 * Use POSIX_FADV_DONTNEED to flush pages and buffers 909 * for the backing file after a POSIX_FADV_NOREUSE 910 * write(2). 911 */ 912 error = VOP_ADVISE(vp, orig_offset, uio->uio_offset - 1, 913 POSIX_FADV_DONTNEED); 914 unlock: 915 return (error); 916 } 917 918 /* 919 * The vn_io_fault() is a wrapper around vn_read() and vn_write() to 920 * prevent the following deadlock: 921 * 922 * Assume that the thread A reads from the vnode vp1 into userspace 923 * buffer buf1 backed by the pages of vnode vp2. If a page in buf1 is 924 * currently not resident, then system ends up with the call chain 925 * vn_read() -> VOP_READ(vp1) -> uiomove() -> [Page Fault] -> 926 * vm_fault(buf1) -> vnode_pager_getpages(vp2) -> VOP_GETPAGES(vp2) 927 * which establishes lock order vp1->vn_lock, then vp2->vn_lock. 928 * If, at the same time, thread B reads from vnode vp2 into buffer buf2 929 * backed by the pages of vnode vp1, and some page in buf2 is not 930 * resident, we get a reversed order vp2->vn_lock, then vp1->vn_lock. 931 * 932 * To prevent the lock order reversal and deadlock, vn_io_fault() does 933 * not allow page faults to happen during VOP_READ() or VOP_WRITE(). 934 * Instead, it first tries to do the whole range i/o with pagefaults 935 * disabled. If all pages in the i/o buffer are resident and mapped, 936 * VOP will succeed (ignoring the genuine filesystem errors). 937 * Otherwise, we get back EFAULT, and vn_io_fault() falls back to do 938 * i/o in chunks, with all pages in the chunk prefaulted and held 939 * using vm_fault_quick_hold_pages(). 940 * 941 * Filesystems using this deadlock avoidance scheme should use the 942 * array of the held pages from uio, saved in the curthread->td_ma, 943 * instead of doing uiomove(). A helper function 944 * vn_io_fault_uiomove() converts uiomove request into 945 * uiomove_fromphys() over td_ma array. 946 * 947 * Since vnode locks do not cover the whole i/o anymore, rangelocks 948 * make the current i/o request atomic with respect to other i/os and 949 * truncations. 950 */ 951 952 /* 953 * Decode vn_io_fault_args and perform the corresponding i/o. 954 */ 955 static int 956 vn_io_fault_doio(struct vn_io_fault_args *args, struct uio *uio, 957 struct thread *td) 958 { 959 int error, save; 960 961 error = 0; 962 save = vm_fault_disable_pagefaults(); 963 switch (args->kind) { 964 case VN_IO_FAULT_FOP: 965 error = (args->args.fop_args.doio)(args->args.fop_args.fp, 966 uio, args->cred, args->flags, td); 967 break; 968 case VN_IO_FAULT_VOP: 969 if (uio->uio_rw == UIO_READ) { 970 error = VOP_READ(args->args.vop_args.vp, uio, 971 args->flags, args->cred); 972 } else if (uio->uio_rw == UIO_WRITE) { 973 error = VOP_WRITE(args->args.vop_args.vp, uio, 974 args->flags, args->cred); 975 } 976 break; 977 default: 978 panic("vn_io_fault_doio: unknown kind of io %d %d", 979 args->kind, uio->uio_rw); 980 } 981 vm_fault_enable_pagefaults(save); 982 return (error); 983 } 984 985 static int 986 vn_io_fault_touch(char *base, const struct uio *uio) 987 { 988 int r; 989 990 r = fubyte(base); 991 if (r == -1 || (uio->uio_rw == UIO_READ && subyte(base, r) == -1)) 992 return (EFAULT); 993 return (0); 994 } 995 996 static int 997 vn_io_fault_prefault_user(const struct uio *uio) 998 { 999 char *base; 1000 const struct iovec *iov; 1001 size_t len; 1002 ssize_t resid; 1003 int error, i; 1004 1005 KASSERT(uio->uio_segflg == UIO_USERSPACE, 1006 ("vn_io_fault_prefault userspace")); 1007 1008 error = i = 0; 1009 iov = uio->uio_iov; 1010 resid = uio->uio_resid; 1011 base = iov->iov_base; 1012 len = iov->iov_len; 1013 while (resid > 0) { 1014 error = vn_io_fault_touch(base, uio); 1015 if (error != 0) 1016 break; 1017 if (len < PAGE_SIZE) { 1018 if (len != 0) { 1019 error = vn_io_fault_touch(base + len - 1, uio); 1020 if (error != 0) 1021 break; 1022 resid -= len; 1023 } 1024 if (++i >= uio->uio_iovcnt) 1025 break; 1026 iov = uio->uio_iov + i; 1027 base = iov->iov_base; 1028 len = iov->iov_len; 1029 } else { 1030 len -= PAGE_SIZE; 1031 base += PAGE_SIZE; 1032 resid -= PAGE_SIZE; 1033 } 1034 } 1035 return (error); 1036 } 1037 1038 /* 1039 * Common code for vn_io_fault(), agnostic to the kind of i/o request. 1040 * Uses vn_io_fault_doio() to make the call to an actual i/o function. 1041 * Used from vn_rdwr() and vn_io_fault(), which encode the i/o request 1042 * into args and call vn_io_fault1() to handle faults during the user 1043 * mode buffer accesses. 1044 */ 1045 static int 1046 vn_io_fault1(struct vnode *vp, struct uio *uio, struct vn_io_fault_args *args, 1047 struct thread *td) 1048 { 1049 vm_page_t ma[io_hold_cnt + 2]; 1050 struct uio *uio_clone, short_uio; 1051 struct iovec short_iovec[1]; 1052 vm_page_t *prev_td_ma; 1053 vm_prot_t prot; 1054 vm_offset_t addr, end; 1055 size_t len, resid; 1056 ssize_t adv; 1057 int error, cnt, saveheld, prev_td_ma_cnt; 1058 1059 if (vn_io_fault_prefault) { 1060 error = vn_io_fault_prefault_user(uio); 1061 if (error != 0) 1062 return (error); /* Or ignore ? */ 1063 } 1064 1065 prot = uio->uio_rw == UIO_READ ? VM_PROT_WRITE : VM_PROT_READ; 1066 1067 /* 1068 * The UFS follows IO_UNIT directive and replays back both 1069 * uio_offset and uio_resid if an error is encountered during the 1070 * operation. But, since the iovec may be already advanced, 1071 * uio is still in an inconsistent state. 1072 * 1073 * Cache a copy of the original uio, which is advanced to the redo 1074 * point using UIO_NOCOPY below. 1075 */ 1076 uio_clone = cloneuio(uio); 1077 resid = uio->uio_resid; 1078 1079 short_uio.uio_segflg = UIO_USERSPACE; 1080 short_uio.uio_rw = uio->uio_rw; 1081 short_uio.uio_td = uio->uio_td; 1082 1083 error = vn_io_fault_doio(args, uio, td); 1084 if (error != EFAULT) 1085 goto out; 1086 1087 atomic_add_long(&vn_io_faults_cnt, 1); 1088 uio_clone->uio_segflg = UIO_NOCOPY; 1089 uiomove(NULL, resid - uio->uio_resid, uio_clone); 1090 uio_clone->uio_segflg = uio->uio_segflg; 1091 1092 saveheld = curthread_pflags_set(TDP_UIOHELD); 1093 prev_td_ma = td->td_ma; 1094 prev_td_ma_cnt = td->td_ma_cnt; 1095 1096 while (uio_clone->uio_resid != 0) { 1097 len = uio_clone->uio_iov->iov_len; 1098 if (len == 0) { 1099 KASSERT(uio_clone->uio_iovcnt >= 1, 1100 ("iovcnt underflow")); 1101 uio_clone->uio_iov++; 1102 uio_clone->uio_iovcnt--; 1103 continue; 1104 } 1105 if (len > io_hold_cnt * PAGE_SIZE) 1106 len = io_hold_cnt * PAGE_SIZE; 1107 addr = (uintptr_t)uio_clone->uio_iov->iov_base; 1108 end = round_page(addr + len); 1109 if (end < addr) { 1110 error = EFAULT; 1111 break; 1112 } 1113 cnt = atop(end - trunc_page(addr)); 1114 /* 1115 * A perfectly misaligned address and length could cause 1116 * both the start and the end of the chunk to use partial 1117 * page. +2 accounts for such a situation. 1118 */ 1119 cnt = vm_fault_quick_hold_pages(&td->td_proc->p_vmspace->vm_map, 1120 addr, len, prot, ma, io_hold_cnt + 2); 1121 if (cnt == -1) { 1122 error = EFAULT; 1123 break; 1124 } 1125 short_uio.uio_iov = &short_iovec[0]; 1126 short_iovec[0].iov_base = (void *)addr; 1127 short_uio.uio_iovcnt = 1; 1128 short_uio.uio_resid = short_iovec[0].iov_len = len; 1129 short_uio.uio_offset = uio_clone->uio_offset; 1130 td->td_ma = ma; 1131 td->td_ma_cnt = cnt; 1132 1133 error = vn_io_fault_doio(args, &short_uio, td); 1134 vm_page_unhold_pages(ma, cnt); 1135 adv = len - short_uio.uio_resid; 1136 1137 uio_clone->uio_iov->iov_base = 1138 (char *)uio_clone->uio_iov->iov_base + adv; 1139 uio_clone->uio_iov->iov_len -= adv; 1140 uio_clone->uio_resid -= adv; 1141 uio_clone->uio_offset += adv; 1142 1143 uio->uio_resid -= adv; 1144 uio->uio_offset += adv; 1145 1146 if (error != 0 || adv == 0) 1147 break; 1148 } 1149 td->td_ma = prev_td_ma; 1150 td->td_ma_cnt = prev_td_ma_cnt; 1151 curthread_pflags_restore(saveheld); 1152 out: 1153 free(uio_clone, M_IOV); 1154 return (error); 1155 } 1156 1157 static int 1158 vn_io_fault(struct file *fp, struct uio *uio, struct ucred *active_cred, 1159 int flags, struct thread *td) 1160 { 1161 fo_rdwr_t *doio; 1162 struct vnode *vp; 1163 void *rl_cookie; 1164 struct vn_io_fault_args args; 1165 int error; 1166 1167 doio = uio->uio_rw == UIO_READ ? vn_read : vn_write; 1168 vp = fp->f_vnode; 1169 foffset_lock_uio(fp, uio, flags); 1170 if (do_vn_io_fault(vp, uio)) { 1171 args.kind = VN_IO_FAULT_FOP; 1172 args.args.fop_args.fp = fp; 1173 args.args.fop_args.doio = doio; 1174 args.cred = active_cred; 1175 args.flags = flags | FOF_OFFSET; 1176 if (uio->uio_rw == UIO_READ) { 1177 rl_cookie = vn_rangelock_rlock(vp, uio->uio_offset, 1178 uio->uio_offset + uio->uio_resid); 1179 } else if ((fp->f_flag & O_APPEND) != 0 || 1180 (flags & FOF_OFFSET) == 0) { 1181 /* For appenders, punt and lock the whole range. */ 1182 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 1183 } else { 1184 rl_cookie = vn_rangelock_wlock(vp, uio->uio_offset, 1185 uio->uio_offset + uio->uio_resid); 1186 } 1187 error = vn_io_fault1(vp, uio, &args, td); 1188 vn_rangelock_unlock(vp, rl_cookie); 1189 } else { 1190 error = doio(fp, uio, active_cred, flags | FOF_OFFSET, td); 1191 } 1192 foffset_unlock_uio(fp, uio, flags); 1193 return (error); 1194 } 1195 1196 /* 1197 * Helper function to perform the requested uiomove operation using 1198 * the held pages for io->uio_iov[0].iov_base buffer instead of 1199 * copyin/copyout. Access to the pages with uiomove_fromphys() 1200 * instead of iov_base prevents page faults that could occur due to 1201 * pmap_collect() invalidating the mapping created by 1202 * vm_fault_quick_hold_pages(), or pageout daemon, page laundry or 1203 * object cleanup revoking the write access from page mappings. 1204 * 1205 * Filesystems specified MNTK_NO_IOPF shall use vn_io_fault_uiomove() 1206 * instead of plain uiomove(). 1207 */ 1208 int 1209 vn_io_fault_uiomove(char *data, int xfersize, struct uio *uio) 1210 { 1211 struct uio transp_uio; 1212 struct iovec transp_iov[1]; 1213 struct thread *td; 1214 size_t adv; 1215 int error, pgadv; 1216 1217 td = curthread; 1218 if ((td->td_pflags & TDP_UIOHELD) == 0 || 1219 uio->uio_segflg != UIO_USERSPACE) 1220 return (uiomove(data, xfersize, uio)); 1221 1222 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt)); 1223 transp_iov[0].iov_base = data; 1224 transp_uio.uio_iov = &transp_iov[0]; 1225 transp_uio.uio_iovcnt = 1; 1226 if (xfersize > uio->uio_resid) 1227 xfersize = uio->uio_resid; 1228 transp_uio.uio_resid = transp_iov[0].iov_len = xfersize; 1229 transp_uio.uio_offset = 0; 1230 transp_uio.uio_segflg = UIO_SYSSPACE; 1231 /* 1232 * Since transp_iov points to data, and td_ma page array 1233 * corresponds to original uio->uio_iov, we need to invert the 1234 * direction of the i/o operation as passed to 1235 * uiomove_fromphys(). 1236 */ 1237 switch (uio->uio_rw) { 1238 case UIO_WRITE: 1239 transp_uio.uio_rw = UIO_READ; 1240 break; 1241 case UIO_READ: 1242 transp_uio.uio_rw = UIO_WRITE; 1243 break; 1244 } 1245 transp_uio.uio_td = uio->uio_td; 1246 error = uiomove_fromphys(td->td_ma, 1247 ((vm_offset_t)uio->uio_iov->iov_base) & PAGE_MASK, 1248 xfersize, &transp_uio); 1249 adv = xfersize - transp_uio.uio_resid; 1250 pgadv = 1251 (((vm_offset_t)uio->uio_iov->iov_base + adv) >> PAGE_SHIFT) - 1252 (((vm_offset_t)uio->uio_iov->iov_base) >> PAGE_SHIFT); 1253 td->td_ma += pgadv; 1254 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt, 1255 pgadv)); 1256 td->td_ma_cnt -= pgadv; 1257 uio->uio_iov->iov_base = (char *)uio->uio_iov->iov_base + adv; 1258 uio->uio_iov->iov_len -= adv; 1259 uio->uio_resid -= adv; 1260 uio->uio_offset += adv; 1261 return (error); 1262 } 1263 1264 int 1265 vn_io_fault_pgmove(vm_page_t ma[], vm_offset_t offset, int xfersize, 1266 struct uio *uio) 1267 { 1268 struct thread *td; 1269 vm_offset_t iov_base; 1270 int cnt, pgadv; 1271 1272 td = curthread; 1273 if ((td->td_pflags & TDP_UIOHELD) == 0 || 1274 uio->uio_segflg != UIO_USERSPACE) 1275 return (uiomove_fromphys(ma, offset, xfersize, uio)); 1276 1277 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt)); 1278 cnt = xfersize > uio->uio_resid ? uio->uio_resid : xfersize; 1279 iov_base = (vm_offset_t)uio->uio_iov->iov_base; 1280 switch (uio->uio_rw) { 1281 case UIO_WRITE: 1282 pmap_copy_pages(td->td_ma, iov_base & PAGE_MASK, ma, 1283 offset, cnt); 1284 break; 1285 case UIO_READ: 1286 pmap_copy_pages(ma, offset, td->td_ma, iov_base & PAGE_MASK, 1287 cnt); 1288 break; 1289 } 1290 pgadv = ((iov_base + cnt) >> PAGE_SHIFT) - (iov_base >> PAGE_SHIFT); 1291 td->td_ma += pgadv; 1292 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt, 1293 pgadv)); 1294 td->td_ma_cnt -= pgadv; 1295 uio->uio_iov->iov_base = (char *)(iov_base + cnt); 1296 uio->uio_iov->iov_len -= cnt; 1297 uio->uio_resid -= cnt; 1298 uio->uio_offset += cnt; 1299 return (0); 1300 } 1301 1302 1303 /* 1304 * File table truncate routine. 1305 */ 1306 static int 1307 vn_truncate(struct file *fp, off_t length, struct ucred *active_cred, 1308 struct thread *td) 1309 { 1310 struct vattr vattr; 1311 struct mount *mp; 1312 struct vnode *vp; 1313 void *rl_cookie; 1314 int error; 1315 1316 vp = fp->f_vnode; 1317 1318 /* 1319 * Lock the whole range for truncation. Otherwise split i/o 1320 * might happen partly before and partly after the truncation. 1321 */ 1322 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 1323 error = vn_start_write(vp, &mp, V_WAIT | PCATCH); 1324 if (error) 1325 goto out1; 1326 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1327 if (vp->v_type == VDIR) { 1328 error = EISDIR; 1329 goto out; 1330 } 1331 #ifdef MAC 1332 error = mac_vnode_check_write(active_cred, fp->f_cred, vp); 1333 if (error) 1334 goto out; 1335 #endif 1336 error = vn_writechk(vp); 1337 if (error == 0) { 1338 VATTR_NULL(&vattr); 1339 vattr.va_size = length; 1340 if ((fp->f_flag & O_FSYNC) != 0) 1341 vattr.va_vaflags |= VA_SYNC; 1342 error = VOP_SETATTR(vp, &vattr, fp->f_cred); 1343 } 1344 out: 1345 VOP_UNLOCK(vp, 0); 1346 vn_finished_write(mp); 1347 out1: 1348 vn_rangelock_unlock(vp, rl_cookie); 1349 return (error); 1350 } 1351 1352 /* 1353 * File table vnode stat routine. 1354 */ 1355 static int 1356 vn_statfile(fp, sb, active_cred, td) 1357 struct file *fp; 1358 struct stat *sb; 1359 struct ucred *active_cred; 1360 struct thread *td; 1361 { 1362 struct vnode *vp = fp->f_vnode; 1363 int error; 1364 1365 vn_lock(vp, LK_SHARED | LK_RETRY); 1366 error = vn_stat(vp, sb, active_cred, fp->f_cred, td); 1367 VOP_UNLOCK(vp, 0); 1368 1369 return (error); 1370 } 1371 1372 /* 1373 * Stat a vnode; implementation for the stat syscall 1374 */ 1375 int 1376 vn_stat(struct vnode *vp, struct stat *sb, struct ucred *active_cred, 1377 struct ucred *file_cred, struct thread *td) 1378 { 1379 struct vattr vattr; 1380 struct vattr *vap; 1381 int error; 1382 u_short mode; 1383 1384 AUDIT_ARG_VNODE1(vp); 1385 #ifdef MAC 1386 error = mac_vnode_check_stat(active_cred, file_cred, vp); 1387 if (error) 1388 return (error); 1389 #endif 1390 1391 vap = &vattr; 1392 1393 /* 1394 * Initialize defaults for new and unusual fields, so that file 1395 * systems which don't support these fields don't need to know 1396 * about them. 1397 */ 1398 vap->va_birthtime.tv_sec = -1; 1399 vap->va_birthtime.tv_nsec = 0; 1400 vap->va_fsid = VNOVAL; 1401 vap->va_rdev = NODEV; 1402 1403 error = VOP_GETATTR(vp, vap, active_cred); 1404 if (error) 1405 return (error); 1406 1407 /* 1408 * Zero the spare stat fields 1409 */ 1410 bzero(sb, sizeof *sb); 1411 1412 /* 1413 * Copy from vattr table 1414 */ 1415 if (vap->va_fsid != VNOVAL) 1416 sb->st_dev = vap->va_fsid; 1417 else 1418 sb->st_dev = vp->v_mount->mnt_stat.f_fsid.val[0]; 1419 sb->st_ino = vap->va_fileid; 1420 mode = vap->va_mode; 1421 switch (vap->va_type) { 1422 case VREG: 1423 mode |= S_IFREG; 1424 break; 1425 case VDIR: 1426 mode |= S_IFDIR; 1427 break; 1428 case VBLK: 1429 mode |= S_IFBLK; 1430 break; 1431 case VCHR: 1432 mode |= S_IFCHR; 1433 break; 1434 case VLNK: 1435 mode |= S_IFLNK; 1436 break; 1437 case VSOCK: 1438 mode |= S_IFSOCK; 1439 break; 1440 case VFIFO: 1441 mode |= S_IFIFO; 1442 break; 1443 default: 1444 return (EBADF); 1445 } 1446 sb->st_mode = mode; 1447 sb->st_nlink = vap->va_nlink; 1448 sb->st_uid = vap->va_uid; 1449 sb->st_gid = vap->va_gid; 1450 sb->st_rdev = vap->va_rdev; 1451 if (vap->va_size > OFF_MAX) 1452 return (EOVERFLOW); 1453 sb->st_size = vap->va_size; 1454 sb->st_atim = vap->va_atime; 1455 sb->st_mtim = vap->va_mtime; 1456 sb->st_ctim = vap->va_ctime; 1457 sb->st_birthtim = vap->va_birthtime; 1458 1459 /* 1460 * According to www.opengroup.org, the meaning of st_blksize is 1461 * "a filesystem-specific preferred I/O block size for this 1462 * object. In some filesystem types, this may vary from file 1463 * to file" 1464 * Use miminum/default of PAGE_SIZE (e.g. for VCHR). 1465 */ 1466 1467 sb->st_blksize = max(PAGE_SIZE, vap->va_blocksize); 1468 1469 sb->st_flags = vap->va_flags; 1470 if (priv_check(td, PRIV_VFS_GENERATION)) 1471 sb->st_gen = 0; 1472 else 1473 sb->st_gen = vap->va_gen; 1474 1475 sb->st_blocks = vap->va_bytes / S_BLKSIZE; 1476 return (0); 1477 } 1478 1479 /* 1480 * File table vnode ioctl routine. 1481 */ 1482 static int 1483 vn_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 1484 struct thread *td) 1485 { 1486 struct vattr vattr; 1487 struct vnode *vp; 1488 int error; 1489 1490 vp = fp->f_vnode; 1491 switch (vp->v_type) { 1492 case VDIR: 1493 case VREG: 1494 switch (com) { 1495 case FIONREAD: 1496 vn_lock(vp, LK_SHARED | LK_RETRY); 1497 error = VOP_GETATTR(vp, &vattr, active_cred); 1498 VOP_UNLOCK(vp, 0); 1499 if (error == 0) 1500 *(int *)data = vattr.va_size - fp->f_offset; 1501 return (error); 1502 case FIONBIO: 1503 case FIOASYNC: 1504 return (0); 1505 default: 1506 return (VOP_IOCTL(vp, com, data, fp->f_flag, 1507 active_cred, td)); 1508 } 1509 default: 1510 return (ENOTTY); 1511 } 1512 } 1513 1514 /* 1515 * File table vnode poll routine. 1516 */ 1517 static int 1518 vn_poll(struct file *fp, int events, struct ucred *active_cred, 1519 struct thread *td) 1520 { 1521 struct vnode *vp; 1522 int error; 1523 1524 vp = fp->f_vnode; 1525 #ifdef MAC 1526 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1527 AUDIT_ARG_VNODE1(vp); 1528 error = mac_vnode_check_poll(active_cred, fp->f_cred, vp); 1529 VOP_UNLOCK(vp, 0); 1530 if (!error) 1531 #endif 1532 1533 error = VOP_POLL(vp, events, fp->f_cred, td); 1534 return (error); 1535 } 1536 1537 /* 1538 * Acquire the requested lock and then check for validity. LK_RETRY 1539 * permits vn_lock to return doomed vnodes. 1540 */ 1541 int 1542 _vn_lock(struct vnode *vp, int flags, char *file, int line) 1543 { 1544 int error; 1545 1546 VNASSERT((flags & LK_TYPE_MASK) != 0, vp, 1547 ("vn_lock: no locktype")); 1548 VNASSERT(vp->v_holdcnt != 0, vp, ("vn_lock: zero hold count")); 1549 retry: 1550 error = VOP_LOCK1(vp, flags, file, line); 1551 flags &= ~LK_INTERLOCK; /* Interlock is always dropped. */ 1552 KASSERT((flags & LK_RETRY) == 0 || error == 0, 1553 ("vn_lock: error %d incompatible with flags %#x", error, flags)); 1554 1555 if ((flags & LK_RETRY) == 0) { 1556 if (error == 0 && (vp->v_iflag & VI_DOOMED) != 0) { 1557 VOP_UNLOCK(vp, 0); 1558 error = ENOENT; 1559 } 1560 } else if (error != 0) 1561 goto retry; 1562 return (error); 1563 } 1564 1565 /* 1566 * File table vnode close routine. 1567 */ 1568 static int 1569 vn_closefile(struct file *fp, struct thread *td) 1570 { 1571 struct vnode *vp; 1572 struct flock lf; 1573 int error; 1574 bool ref; 1575 1576 vp = fp->f_vnode; 1577 fp->f_ops = &badfileops; 1578 ref= (fp->f_flag & FHASLOCK) != 0 && fp->f_type == DTYPE_VNODE; 1579 1580 error = vn_close1(vp, fp->f_flag, fp->f_cred, td, ref); 1581 1582 if (__predict_false(ref)) { 1583 lf.l_whence = SEEK_SET; 1584 lf.l_start = 0; 1585 lf.l_len = 0; 1586 lf.l_type = F_UNLCK; 1587 (void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, F_FLOCK); 1588 vrele(vp); 1589 } 1590 return (error); 1591 } 1592 1593 static bool 1594 vn_suspendable(struct mount *mp) 1595 { 1596 1597 return (mp->mnt_op->vfs_susp_clean != NULL); 1598 } 1599 1600 /* 1601 * Preparing to start a filesystem write operation. If the operation is 1602 * permitted, then we bump the count of operations in progress and 1603 * proceed. If a suspend request is in progress, we wait until the 1604 * suspension is over, and then proceed. 1605 */ 1606 static int 1607 vn_start_write_locked(struct mount *mp, int flags) 1608 { 1609 int error, mflags; 1610 1611 mtx_assert(MNT_MTX(mp), MA_OWNED); 1612 error = 0; 1613 1614 /* 1615 * Check on status of suspension. 1616 */ 1617 if ((curthread->td_pflags & TDP_IGNSUSP) == 0 || 1618 mp->mnt_susp_owner != curthread) { 1619 mflags = ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0 ? 1620 (flags & PCATCH) : 0) | (PUSER - 1); 1621 while ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { 1622 if (flags & V_NOWAIT) { 1623 error = EWOULDBLOCK; 1624 goto unlock; 1625 } 1626 error = msleep(&mp->mnt_flag, MNT_MTX(mp), mflags, 1627 "suspfs", 0); 1628 if (error) 1629 goto unlock; 1630 } 1631 } 1632 if (flags & V_XSLEEP) 1633 goto unlock; 1634 mp->mnt_writeopcount++; 1635 unlock: 1636 if (error != 0 || (flags & V_XSLEEP) != 0) 1637 MNT_REL(mp); 1638 MNT_IUNLOCK(mp); 1639 return (error); 1640 } 1641 1642 int 1643 vn_start_write(struct vnode *vp, struct mount **mpp, int flags) 1644 { 1645 struct mount *mp; 1646 int error; 1647 1648 KASSERT((flags & V_MNTREF) == 0 || (*mpp != NULL && vp == NULL), 1649 ("V_MNTREF requires mp")); 1650 1651 error = 0; 1652 /* 1653 * If a vnode is provided, get and return the mount point that 1654 * to which it will write. 1655 */ 1656 if (vp != NULL) { 1657 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) { 1658 *mpp = NULL; 1659 if (error != EOPNOTSUPP) 1660 return (error); 1661 return (0); 1662 } 1663 } 1664 if ((mp = *mpp) == NULL) 1665 return (0); 1666 1667 if (!vn_suspendable(mp)) { 1668 if (vp != NULL || (flags & V_MNTREF) != 0) 1669 vfs_rel(mp); 1670 return (0); 1671 } 1672 1673 /* 1674 * VOP_GETWRITEMOUNT() returns with the mp refcount held through 1675 * a vfs_ref(). 1676 * As long as a vnode is not provided we need to acquire a 1677 * refcount for the provided mountpoint too, in order to 1678 * emulate a vfs_ref(). 1679 */ 1680 MNT_ILOCK(mp); 1681 if (vp == NULL && (flags & V_MNTREF) == 0) 1682 MNT_REF(mp); 1683 1684 return (vn_start_write_locked(mp, flags)); 1685 } 1686 1687 /* 1688 * Secondary suspension. Used by operations such as vop_inactive 1689 * routines that are needed by the higher level functions. These 1690 * are allowed to proceed until all the higher level functions have 1691 * completed (indicated by mnt_writeopcount dropping to zero). At that 1692 * time, these operations are halted until the suspension is over. 1693 */ 1694 int 1695 vn_start_secondary_write(struct vnode *vp, struct mount **mpp, int flags) 1696 { 1697 struct mount *mp; 1698 int error; 1699 1700 KASSERT((flags & V_MNTREF) == 0 || (*mpp != NULL && vp == NULL), 1701 ("V_MNTREF requires mp")); 1702 1703 retry: 1704 if (vp != NULL) { 1705 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) { 1706 *mpp = NULL; 1707 if (error != EOPNOTSUPP) 1708 return (error); 1709 return (0); 1710 } 1711 } 1712 /* 1713 * If we are not suspended or have not yet reached suspended 1714 * mode, then let the operation proceed. 1715 */ 1716 if ((mp = *mpp) == NULL) 1717 return (0); 1718 1719 if (!vn_suspendable(mp)) { 1720 if (vp != NULL || (flags & V_MNTREF) != 0) 1721 vfs_rel(mp); 1722 return (0); 1723 } 1724 1725 /* 1726 * VOP_GETWRITEMOUNT() returns with the mp refcount held through 1727 * a vfs_ref(). 1728 * As long as a vnode is not provided we need to acquire a 1729 * refcount for the provided mountpoint too, in order to 1730 * emulate a vfs_ref(). 1731 */ 1732 MNT_ILOCK(mp); 1733 if (vp == NULL && (flags & V_MNTREF) == 0) 1734 MNT_REF(mp); 1735 if ((mp->mnt_kern_flag & (MNTK_SUSPENDED | MNTK_SUSPEND2)) == 0) { 1736 mp->mnt_secondary_writes++; 1737 mp->mnt_secondary_accwrites++; 1738 MNT_IUNLOCK(mp); 1739 return (0); 1740 } 1741 if (flags & V_NOWAIT) { 1742 MNT_REL(mp); 1743 MNT_IUNLOCK(mp); 1744 return (EWOULDBLOCK); 1745 } 1746 /* 1747 * Wait for the suspension to finish. 1748 */ 1749 error = msleep(&mp->mnt_flag, MNT_MTX(mp), (PUSER - 1) | PDROP | 1750 ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0 ? (flags & PCATCH) : 0), 1751 "suspfs", 0); 1752 vfs_rel(mp); 1753 if (error == 0) 1754 goto retry; 1755 return (error); 1756 } 1757 1758 /* 1759 * Filesystem write operation has completed. If we are suspending and this 1760 * operation is the last one, notify the suspender that the suspension is 1761 * now in effect. 1762 */ 1763 void 1764 vn_finished_write(struct mount *mp) 1765 { 1766 if (mp == NULL || !vn_suspendable(mp)) 1767 return; 1768 MNT_ILOCK(mp); 1769 MNT_REL(mp); 1770 mp->mnt_writeopcount--; 1771 if (mp->mnt_writeopcount < 0) 1772 panic("vn_finished_write: neg cnt"); 1773 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && 1774 mp->mnt_writeopcount <= 0) 1775 wakeup(&mp->mnt_writeopcount); 1776 MNT_IUNLOCK(mp); 1777 } 1778 1779 1780 /* 1781 * Filesystem secondary write operation has completed. If we are 1782 * suspending and this operation is the last one, notify the suspender 1783 * that the suspension is now in effect. 1784 */ 1785 void 1786 vn_finished_secondary_write(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 static inline void 2321 vn_fill_junk(struct kinfo_file *kif) 2322 { 2323 size_t len, olen; 2324 2325 /* 2326 * Simulate vn_fullpath returning changing values for a given 2327 * vp during e.g. coredump. 2328 */ 2329 len = (arc4random() % (sizeof(kif->kf_path) - 2)) + 1; 2330 olen = strlen(kif->kf_path); 2331 if (len < olen) 2332 strcpy(&kif->kf_path[len - 1], "$"); 2333 else 2334 for (; olen < len; olen++) 2335 strcpy(&kif->kf_path[olen], "A"); 2336 } 2337 2338 int 2339 vn_fill_kinfo_vnode(struct vnode *vp, struct kinfo_file *kif) 2340 { 2341 struct vattr va; 2342 char *fullpath, *freepath; 2343 int error; 2344 2345 kif->kf_vnode_type = vntype_to_kinfo(vp->v_type); 2346 freepath = NULL; 2347 fullpath = "-"; 2348 error = vn_fullpath(curthread, vp, &fullpath, &freepath); 2349 if (error == 0) { 2350 strlcpy(kif->kf_path, fullpath, sizeof(kif->kf_path)); 2351 } 2352 if (freepath != NULL) 2353 free(freepath, M_TEMP); 2354 2355 KFAIL_POINT_CODE(DEBUG_FP, fill_kinfo_vnode__random_path, 2356 vn_fill_junk(kif); 2357 ); 2358 2359 /* 2360 * Retrieve vnode attributes. 2361 */ 2362 va.va_fsid = VNOVAL; 2363 va.va_rdev = NODEV; 2364 vn_lock(vp, LK_SHARED | LK_RETRY); 2365 error = VOP_GETATTR(vp, &va, curthread->td_ucred); 2366 VOP_UNLOCK(vp, 0); 2367 if (error != 0) 2368 return (error); 2369 if (va.va_fsid != VNOVAL) 2370 kif->kf_un.kf_file.kf_file_fsid = va.va_fsid; 2371 else 2372 kif->kf_un.kf_file.kf_file_fsid = 2373 vp->v_mount->mnt_stat.f_fsid.val[0]; 2374 kif->kf_un.kf_file.kf_file_fileid = va.va_fileid; 2375 kif->kf_un.kf_file.kf_file_mode = MAKEIMODE(va.va_type, va.va_mode); 2376 kif->kf_un.kf_file.kf_file_size = va.va_size; 2377 kif->kf_un.kf_file.kf_file_rdev = va.va_rdev; 2378 return (0); 2379 } 2380 2381 int 2382 vn_mmap(struct file *fp, vm_map_t map, vm_offset_t *addr, vm_size_t size, 2383 vm_prot_t prot, vm_prot_t cap_maxprot, int flags, vm_ooffset_t foff, 2384 struct thread *td) 2385 { 2386 #ifdef HWPMC_HOOKS 2387 struct pmckern_map_in pkm; 2388 #endif 2389 struct mount *mp; 2390 struct vnode *vp; 2391 vm_object_t object; 2392 vm_prot_t maxprot; 2393 boolean_t writecounted; 2394 int error; 2395 2396 #if defined(COMPAT_FREEBSD7) || defined(COMPAT_FREEBSD6) || \ 2397 defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4) 2398 /* 2399 * POSIX shared-memory objects are defined to have 2400 * kernel persistence, and are not defined to support 2401 * read(2)/write(2) -- or even open(2). Thus, we can 2402 * use MAP_ASYNC to trade on-disk coherence for speed. 2403 * The shm_open(3) library routine turns on the FPOSIXSHM 2404 * flag to request this behavior. 2405 */ 2406 if ((fp->f_flag & FPOSIXSHM) != 0) 2407 flags |= MAP_NOSYNC; 2408 #endif 2409 vp = fp->f_vnode; 2410 2411 /* 2412 * Ensure that file and memory protections are 2413 * compatible. Note that we only worry about 2414 * writability if mapping is shared; in this case, 2415 * current and max prot are dictated by the open file. 2416 * XXX use the vnode instead? Problem is: what 2417 * credentials do we use for determination? What if 2418 * proc does a setuid? 2419 */ 2420 mp = vp->v_mount; 2421 if (mp != NULL && (mp->mnt_flag & MNT_NOEXEC) != 0) { 2422 maxprot = VM_PROT_NONE; 2423 if ((prot & VM_PROT_EXECUTE) != 0) 2424 return (EACCES); 2425 } else 2426 maxprot = VM_PROT_EXECUTE; 2427 if ((fp->f_flag & FREAD) != 0) 2428 maxprot |= VM_PROT_READ; 2429 else if ((prot & VM_PROT_READ) != 0) 2430 return (EACCES); 2431 2432 /* 2433 * If we are sharing potential changes via MAP_SHARED and we 2434 * are trying to get write permission although we opened it 2435 * without asking for it, bail out. 2436 */ 2437 if ((flags & MAP_SHARED) != 0) { 2438 if ((fp->f_flag & FWRITE) != 0) 2439 maxprot |= VM_PROT_WRITE; 2440 else if ((prot & VM_PROT_WRITE) != 0) 2441 return (EACCES); 2442 } else { 2443 maxprot |= VM_PROT_WRITE; 2444 cap_maxprot |= VM_PROT_WRITE; 2445 } 2446 maxprot &= cap_maxprot; 2447 2448 /* 2449 * For regular files and shared memory, POSIX requires that 2450 * the value of foff be a legitimate offset within the data 2451 * object. In particular, negative offsets are invalid. 2452 * Blocking negative offsets and overflows here avoids 2453 * possible wraparound or user-level access into reserved 2454 * ranges of the data object later. In contrast, POSIX does 2455 * not dictate how offsets are used by device drivers, so in 2456 * the case of a device mapping a negative offset is passed 2457 * on. 2458 */ 2459 if ( 2460 #ifdef _LP64 2461 size > OFF_MAX || 2462 #endif 2463 foff < 0 || foff > OFF_MAX - size) 2464 return (EINVAL); 2465 2466 writecounted = FALSE; 2467 error = vm_mmap_vnode(td, size, prot, &maxprot, &flags, vp, 2468 &foff, &object, &writecounted); 2469 if (error != 0) 2470 return (error); 2471 error = vm_mmap_object(map, addr, size, prot, maxprot, flags, object, 2472 foff, writecounted, td); 2473 if (error != 0) { 2474 /* 2475 * If this mapping was accounted for in the vnode's 2476 * writecount, then undo that now. 2477 */ 2478 if (writecounted) 2479 vnode_pager_release_writecount(object, 0, size); 2480 vm_object_deallocate(object); 2481 } 2482 #ifdef HWPMC_HOOKS 2483 /* Inform hwpmc(4) if an executable is being mapped. */ 2484 if (PMC_HOOK_INSTALLED(PMC_FN_MMAP)) { 2485 if ((prot & VM_PROT_EXECUTE) != 0 && error == 0) { 2486 pkm.pm_file = vp; 2487 pkm.pm_address = (uintptr_t) *addr; 2488 PMC_CALL_HOOK(td, PMC_FN_MMAP, (void *) &pkm); 2489 } 2490 } 2491 #endif 2492 return (error); 2493 }
Cache object: a025246abad6f013323921b2c9528e4b
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