1 /*- 2 * Copyright (c) 1982, 1986, 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Copyright (c) 2012 Konstantin Belousov <kib@FreeBSD.org> 11 * Copyright (c) 2013, 2014 The FreeBSD Foundation 12 * 13 * Portions of this software were developed by Konstantin Belousov 14 * under sponsorship from the FreeBSD Foundation. 15 * 16 * Redistribution and use in source and binary forms, with or without 17 * modification, are permitted provided that the following conditions 18 * are met: 19 * 1. Redistributions of source code must retain the above copyright 20 * notice, this list of conditions and the following disclaimer. 21 * 2. Redistributions in binary form must reproduce the above copyright 22 * notice, this list of conditions and the following disclaimer in the 23 * documentation and/or other materials provided with the distribution. 24 * 4. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 * 40 * @(#)vfs_vnops.c 8.2 (Berkeley) 1/21/94 41 */ 42 43 #include <sys/cdefs.h> 44 __FBSDID("$FreeBSD$"); 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 #include <sys/disk.h> 49 #include <sys/fcntl.h> 50 #include <sys/file.h> 51 #include <sys/kdb.h> 52 #include <sys/stat.h> 53 #include <sys/priv.h> 54 #include <sys/proc.h> 55 #include <sys/limits.h> 56 #include <sys/lock.h> 57 #include <sys/mount.h> 58 #include <sys/mutex.h> 59 #include <sys/namei.h> 60 #include <sys/vnode.h> 61 #include <sys/bio.h> 62 #include <sys/buf.h> 63 #include <sys/filio.h> 64 #include <sys/resourcevar.h> 65 #include <sys/rwlock.h> 66 #include <sys/sx.h> 67 #include <sys/sysctl.h> 68 #include <sys/ttycom.h> 69 #include <sys/conf.h> 70 #include <sys/syslog.h> 71 #include <sys/unistd.h> 72 #include <sys/user.h> 73 74 #include <security/audit/audit.h> 75 #include <security/mac/mac_framework.h> 76 77 #include <vm/vm.h> 78 #include <vm/vm_extern.h> 79 #include <vm/pmap.h> 80 #include <vm/vm_map.h> 81 #include <vm/vm_object.h> 82 #include <vm/vm_page.h> 83 84 static fo_rdwr_t vn_read; 85 static fo_rdwr_t vn_write; 86 static fo_rdwr_t vn_io_fault; 87 static fo_truncate_t vn_truncate; 88 static fo_ioctl_t vn_ioctl; 89 static fo_poll_t vn_poll; 90 static fo_kqfilter_t vn_kqfilter; 91 static fo_stat_t vn_statfile; 92 static fo_close_t vn_closefile; 93 94 struct fileops vnops = { 95 .fo_read = vn_io_fault, 96 .fo_write = vn_io_fault, 97 .fo_truncate = vn_truncate, 98 .fo_ioctl = vn_ioctl, 99 .fo_poll = vn_poll, 100 .fo_kqfilter = vn_kqfilter, 101 .fo_stat = vn_statfile, 102 .fo_close = vn_closefile, 103 .fo_chmod = vn_chmod, 104 .fo_chown = vn_chown, 105 .fo_sendfile = vn_sendfile, 106 .fo_seek = vn_seek, 107 .fo_fill_kinfo = vn_fill_kinfo, 108 .fo_flags = DFLAG_PASSABLE | DFLAG_SEEKABLE 109 }; 110 111 static const int io_hold_cnt = 16; 112 static int vn_io_fault_enable = 1; 113 SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_enable, CTLFLAG_RW, 114 &vn_io_fault_enable, 0, "Enable vn_io_fault lock avoidance"); 115 static u_long vn_io_faults_cnt; 116 SYSCTL_ULONG(_debug, OID_AUTO, vn_io_faults, CTLFLAG_RD, 117 &vn_io_faults_cnt, 0, "Count of vn_io_fault lock avoidance triggers"); 118 119 /* 120 * Returns true if vn_io_fault mode of handling the i/o request should 121 * be used. 122 */ 123 static bool 124 do_vn_io_fault(struct vnode *vp, struct uio *uio) 125 { 126 struct mount *mp; 127 128 return (uio->uio_segflg == UIO_USERSPACE && vp->v_type == VREG && 129 (mp = vp->v_mount) != NULL && 130 (mp->mnt_kern_flag & MNTK_NO_IOPF) != 0 && vn_io_fault_enable); 131 } 132 133 /* 134 * Structure used to pass arguments to vn_io_fault1(), to do either 135 * file- or vnode-based I/O calls. 136 */ 137 struct vn_io_fault_args { 138 enum { 139 VN_IO_FAULT_FOP, 140 VN_IO_FAULT_VOP 141 } kind; 142 struct ucred *cred; 143 int flags; 144 union { 145 struct fop_args_tag { 146 struct file *fp; 147 fo_rdwr_t *doio; 148 } fop_args; 149 struct vop_args_tag { 150 struct vnode *vp; 151 } vop_args; 152 } args; 153 }; 154 155 static int vn_io_fault1(struct vnode *vp, struct uio *uio, 156 struct vn_io_fault_args *args, struct thread *td); 157 158 int 159 vn_open(ndp, flagp, cmode, fp) 160 struct nameidata *ndp; 161 int *flagp, cmode; 162 struct file *fp; 163 { 164 struct thread *td = ndp->ni_cnd.cn_thread; 165 166 return (vn_open_cred(ndp, flagp, cmode, 0, td->td_ucred, fp)); 167 } 168 169 /* 170 * Common code for vnode open operations via a name lookup. 171 * Lookup the vnode and invoke VOP_CREATE if needed. 172 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine. 173 * 174 * Note that this does NOT free nameidata for the successful case, 175 * due to the NDINIT being done elsewhere. 176 */ 177 int 178 vn_open_cred(struct nameidata *ndp, int *flagp, int cmode, u_int vn_open_flags, 179 struct ucred *cred, struct file *fp) 180 { 181 struct vnode *vp; 182 struct mount *mp; 183 struct thread *td = ndp->ni_cnd.cn_thread; 184 struct vattr vat; 185 struct vattr *vap = &vat; 186 int fmode, error; 187 188 restart: 189 fmode = *flagp; 190 if (fmode & O_CREAT) { 191 ndp->ni_cnd.cn_nameiop = CREATE; 192 /* 193 * Set NOCACHE to avoid flushing the cache when 194 * rolling in many files at once. 195 */ 196 ndp->ni_cnd.cn_flags = ISOPEN | LOCKPARENT | LOCKLEAF | NOCACHE; 197 if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0) 198 ndp->ni_cnd.cn_flags |= FOLLOW; 199 if (!(vn_open_flags & VN_OPEN_NOAUDIT)) 200 ndp->ni_cnd.cn_flags |= AUDITVNODE1; 201 if (vn_open_flags & VN_OPEN_NOCAPCHECK) 202 ndp->ni_cnd.cn_flags |= NOCAPCHECK; 203 bwillwrite(); 204 if ((error = namei(ndp)) != 0) 205 return (error); 206 if (ndp->ni_vp == NULL) { 207 VATTR_NULL(vap); 208 vap->va_type = VREG; 209 vap->va_mode = cmode; 210 if (fmode & O_EXCL) 211 vap->va_vaflags |= VA_EXCLUSIVE; 212 if (vn_start_write(ndp->ni_dvp, &mp, V_NOWAIT) != 0) { 213 NDFREE(ndp, NDF_ONLY_PNBUF); 214 vput(ndp->ni_dvp); 215 if ((error = vn_start_write(NULL, &mp, 216 V_XSLEEP | PCATCH)) != 0) 217 return (error); 218 goto restart; 219 } 220 if ((vn_open_flags & VN_OPEN_NAMECACHE) != 0) 221 ndp->ni_cnd.cn_flags |= MAKEENTRY; 222 #ifdef MAC 223 error = mac_vnode_check_create(cred, ndp->ni_dvp, 224 &ndp->ni_cnd, vap); 225 if (error == 0) 226 #endif 227 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp, 228 &ndp->ni_cnd, vap); 229 vput(ndp->ni_dvp); 230 vn_finished_write(mp); 231 if (error) { 232 NDFREE(ndp, NDF_ONLY_PNBUF); 233 return (error); 234 } 235 fmode &= ~O_TRUNC; 236 vp = ndp->ni_vp; 237 } else { 238 if (ndp->ni_dvp == ndp->ni_vp) 239 vrele(ndp->ni_dvp); 240 else 241 vput(ndp->ni_dvp); 242 ndp->ni_dvp = NULL; 243 vp = ndp->ni_vp; 244 if (fmode & O_EXCL) { 245 error = EEXIST; 246 goto bad; 247 } 248 fmode &= ~O_CREAT; 249 } 250 } else { 251 ndp->ni_cnd.cn_nameiop = LOOKUP; 252 ndp->ni_cnd.cn_flags = ISOPEN | 253 ((fmode & O_NOFOLLOW) ? NOFOLLOW : FOLLOW) | LOCKLEAF; 254 if (!(fmode & FWRITE)) 255 ndp->ni_cnd.cn_flags |= LOCKSHARED; 256 if (!(vn_open_flags & VN_OPEN_NOAUDIT)) 257 ndp->ni_cnd.cn_flags |= AUDITVNODE1; 258 if (vn_open_flags & VN_OPEN_NOCAPCHECK) 259 ndp->ni_cnd.cn_flags |= NOCAPCHECK; 260 if ((error = namei(ndp)) != 0) 261 return (error); 262 vp = ndp->ni_vp; 263 } 264 error = vn_open_vnode(vp, fmode, cred, td, fp); 265 if (error) 266 goto bad; 267 *flagp = fmode; 268 return (0); 269 bad: 270 NDFREE(ndp, NDF_ONLY_PNBUF); 271 vput(vp); 272 *flagp = fmode; 273 ndp->ni_vp = NULL; 274 return (error); 275 } 276 277 /* 278 * Common code for vnode open operations once a vnode is located. 279 * Check permissions, and call the VOP_OPEN routine. 280 */ 281 int 282 vn_open_vnode(struct vnode *vp, int fmode, struct ucred *cred, 283 struct thread *td, struct file *fp) 284 { 285 struct mount *mp; 286 accmode_t accmode; 287 struct flock lf; 288 int error, have_flock, lock_flags, type; 289 290 if (vp->v_type == VLNK) 291 return (EMLINK); 292 if (vp->v_type == VSOCK) 293 return (EOPNOTSUPP); 294 if (vp->v_type != VDIR && fmode & O_DIRECTORY) 295 return (ENOTDIR); 296 accmode = 0; 297 if (fmode & (FWRITE | O_TRUNC)) { 298 if (vp->v_type == VDIR) 299 return (EISDIR); 300 accmode |= VWRITE; 301 } 302 if (fmode & FREAD) 303 accmode |= VREAD; 304 if (fmode & FEXEC) 305 accmode |= VEXEC; 306 if ((fmode & O_APPEND) && (fmode & FWRITE)) 307 accmode |= VAPPEND; 308 #ifdef MAC 309 error = mac_vnode_check_open(cred, vp, accmode); 310 if (error) 311 return (error); 312 #endif 313 if ((fmode & O_CREAT) == 0) { 314 if (accmode & VWRITE) { 315 error = vn_writechk(vp); 316 if (error) 317 return (error); 318 } 319 if (accmode) { 320 error = VOP_ACCESS(vp, accmode, cred, td); 321 if (error) 322 return (error); 323 } 324 } 325 if (vp->v_type == VFIFO && VOP_ISLOCKED(vp) != LK_EXCLUSIVE) 326 vn_lock(vp, LK_UPGRADE | LK_RETRY); 327 if ((error = VOP_OPEN(vp, fmode, cred, td, fp)) != 0) 328 return (error); 329 330 if (fmode & (O_EXLOCK | O_SHLOCK)) { 331 KASSERT(fp != NULL, ("open with flock requires fp")); 332 lock_flags = VOP_ISLOCKED(vp); 333 VOP_UNLOCK(vp, 0); 334 lf.l_whence = SEEK_SET; 335 lf.l_start = 0; 336 lf.l_len = 0; 337 if (fmode & O_EXLOCK) 338 lf.l_type = F_WRLCK; 339 else 340 lf.l_type = F_RDLCK; 341 type = F_FLOCK; 342 if ((fmode & FNONBLOCK) == 0) 343 type |= F_WAIT; 344 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, type); 345 have_flock = (error == 0); 346 vn_lock(vp, lock_flags | LK_RETRY); 347 if (error == 0 && vp->v_iflag & VI_DOOMED) 348 error = ENOENT; 349 /* 350 * Another thread might have used this vnode as an 351 * executable while the vnode lock was dropped. 352 * Ensure the vnode is still able to be opened for 353 * writing after the lock has been obtained. 354 */ 355 if (error == 0 && accmode & VWRITE) 356 error = vn_writechk(vp); 357 if (error) { 358 VOP_UNLOCK(vp, 0); 359 if (have_flock) { 360 lf.l_whence = SEEK_SET; 361 lf.l_start = 0; 362 lf.l_len = 0; 363 lf.l_type = F_UNLCK; 364 (void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, 365 F_FLOCK); 366 } 367 vn_start_write(vp, &mp, V_WAIT); 368 vn_lock(vp, lock_flags | LK_RETRY); 369 (void)VOP_CLOSE(vp, fmode, cred, td); 370 vn_finished_write(mp); 371 /* Prevent second close from fdrop()->vn_close(). */ 372 if (fp != NULL) 373 fp->f_ops= &badfileops; 374 return (error); 375 } 376 fp->f_flag |= FHASLOCK; 377 } 378 if (fmode & FWRITE) { 379 VOP_ADD_WRITECOUNT(vp, 1); 380 CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d", 381 __func__, vp, vp->v_writecount); 382 } 383 ASSERT_VOP_LOCKED(vp, "vn_open_vnode"); 384 return (0); 385 } 386 387 /* 388 * Check for write permissions on the specified vnode. 389 * Prototype text segments cannot be written. 390 */ 391 int 392 vn_writechk(vp) 393 register struct vnode *vp; 394 { 395 396 ASSERT_VOP_LOCKED(vp, "vn_writechk"); 397 /* 398 * If there's shared text associated with 399 * the vnode, try to free it up once. If 400 * we fail, we can't allow writing. 401 */ 402 if (VOP_IS_TEXT(vp)) 403 return (ETXTBSY); 404 405 return (0); 406 } 407 408 /* 409 * Vnode close call 410 */ 411 int 412 vn_close(vp, flags, file_cred, td) 413 register struct vnode *vp; 414 int flags; 415 struct ucred *file_cred; 416 struct thread *td; 417 { 418 struct mount *mp; 419 int error, lock_flags; 420 421 if (vp->v_type != VFIFO && (flags & FWRITE) == 0 && 422 MNT_EXTENDED_SHARED(vp->v_mount)) 423 lock_flags = LK_SHARED; 424 else 425 lock_flags = LK_EXCLUSIVE; 426 427 vn_start_write(vp, &mp, V_WAIT); 428 vn_lock(vp, lock_flags | LK_RETRY); 429 if (flags & FWRITE) { 430 VNASSERT(vp->v_writecount > 0, vp, 431 ("vn_close: negative writecount")); 432 VOP_ADD_WRITECOUNT(vp, -1); 433 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d", 434 __func__, vp, vp->v_writecount); 435 } 436 error = VOP_CLOSE(vp, flags, file_cred, td); 437 vput(vp); 438 vn_finished_write(mp); 439 return (error); 440 } 441 442 /* 443 * Heuristic to detect sequential operation. 444 */ 445 static int 446 sequential_heuristic(struct uio *uio, struct file *fp) 447 { 448 449 ASSERT_VOP_LOCKED(fp->f_vnode, __func__); 450 if (fp->f_flag & FRDAHEAD) 451 return (fp->f_seqcount << IO_SEQSHIFT); 452 453 /* 454 * Offset 0 is handled specially. open() sets f_seqcount to 1 so 455 * that the first I/O is normally considered to be slightly 456 * sequential. Seeking to offset 0 doesn't change sequentiality 457 * unless previous seeks have reduced f_seqcount to 0, in which 458 * case offset 0 is not special. 459 */ 460 if ((uio->uio_offset == 0 && fp->f_seqcount > 0) || 461 uio->uio_offset == fp->f_nextoff) { 462 /* 463 * f_seqcount is in units of fixed-size blocks so that it 464 * depends mainly on the amount of sequential I/O and not 465 * much on the number of sequential I/O's. The fixed size 466 * of 16384 is hard-coded here since it is (not quite) just 467 * a magic size that works well here. This size is more 468 * closely related to the best I/O size for real disks than 469 * to any block size used by software. 470 */ 471 fp->f_seqcount += howmany(uio->uio_resid, 16384); 472 if (fp->f_seqcount > IO_SEQMAX) 473 fp->f_seqcount = IO_SEQMAX; 474 return (fp->f_seqcount << IO_SEQSHIFT); 475 } 476 477 /* Not sequential. Quickly draw-down sequentiality. */ 478 if (fp->f_seqcount > 1) 479 fp->f_seqcount = 1; 480 else 481 fp->f_seqcount = 0; 482 return (0); 483 } 484 485 /* 486 * Package up an I/O request on a vnode into a uio and do it. 487 */ 488 int 489 vn_rdwr(enum uio_rw rw, struct vnode *vp, void *base, int len, off_t offset, 490 enum uio_seg segflg, int ioflg, struct ucred *active_cred, 491 struct ucred *file_cred, ssize_t *aresid, struct thread *td) 492 { 493 struct uio auio; 494 struct iovec aiov; 495 struct mount *mp; 496 struct ucred *cred; 497 void *rl_cookie; 498 struct vn_io_fault_args args; 499 int error, lock_flags; 500 501 auio.uio_iov = &aiov; 502 auio.uio_iovcnt = 1; 503 aiov.iov_base = base; 504 aiov.iov_len = len; 505 auio.uio_resid = len; 506 auio.uio_offset = offset; 507 auio.uio_segflg = segflg; 508 auio.uio_rw = rw; 509 auio.uio_td = td; 510 error = 0; 511 512 if ((ioflg & IO_NODELOCKED) == 0) { 513 if ((ioflg & IO_RANGELOCKED) == 0) { 514 if (rw == UIO_READ) { 515 rl_cookie = vn_rangelock_rlock(vp, offset, 516 offset + len); 517 } else { 518 rl_cookie = vn_rangelock_wlock(vp, offset, 519 offset + len); 520 } 521 } else 522 rl_cookie = NULL; 523 mp = NULL; 524 if (rw == UIO_WRITE) { 525 if (vp->v_type != VCHR && 526 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) 527 != 0) 528 goto out; 529 if (MNT_SHARED_WRITES(mp) || 530 ((mp == NULL) && MNT_SHARED_WRITES(vp->v_mount))) 531 lock_flags = LK_SHARED; 532 else 533 lock_flags = LK_EXCLUSIVE; 534 } else 535 lock_flags = LK_SHARED; 536 vn_lock(vp, lock_flags | LK_RETRY); 537 } else 538 rl_cookie = NULL; 539 540 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 541 #ifdef MAC 542 if ((ioflg & IO_NOMACCHECK) == 0) { 543 if (rw == UIO_READ) 544 error = mac_vnode_check_read(active_cred, file_cred, 545 vp); 546 else 547 error = mac_vnode_check_write(active_cred, file_cred, 548 vp); 549 } 550 #endif 551 if (error == 0) { 552 if (file_cred != NULL) 553 cred = file_cred; 554 else 555 cred = active_cred; 556 if (do_vn_io_fault(vp, &auio)) { 557 args.kind = VN_IO_FAULT_VOP; 558 args.cred = cred; 559 args.flags = ioflg; 560 args.args.vop_args.vp = vp; 561 error = vn_io_fault1(vp, &auio, &args, td); 562 } else if (rw == UIO_READ) { 563 error = VOP_READ(vp, &auio, ioflg, cred); 564 } else /* if (rw == UIO_WRITE) */ { 565 error = VOP_WRITE(vp, &auio, ioflg, cred); 566 } 567 } 568 if (aresid) 569 *aresid = auio.uio_resid; 570 else 571 if (auio.uio_resid && error == 0) 572 error = EIO; 573 if ((ioflg & IO_NODELOCKED) == 0) { 574 VOP_UNLOCK(vp, 0); 575 if (mp != NULL) 576 vn_finished_write(mp); 577 } 578 out: 579 if (rl_cookie != NULL) 580 vn_rangelock_unlock(vp, rl_cookie); 581 return (error); 582 } 583 584 /* 585 * Package up an I/O request on a vnode into a uio and do it. The I/O 586 * request is split up into smaller chunks and we try to avoid saturating 587 * the buffer cache while potentially holding a vnode locked, so we 588 * check bwillwrite() before calling vn_rdwr(). We also call kern_yield() 589 * to give other processes a chance to lock the vnode (either other processes 590 * core'ing the same binary, or unrelated processes scanning the directory). 591 */ 592 int 593 vn_rdwr_inchunks(rw, vp, base, len, offset, segflg, ioflg, active_cred, 594 file_cred, aresid, td) 595 enum uio_rw rw; 596 struct vnode *vp; 597 void *base; 598 size_t len; 599 off_t offset; 600 enum uio_seg segflg; 601 int ioflg; 602 struct ucred *active_cred; 603 struct ucred *file_cred; 604 size_t *aresid; 605 struct thread *td; 606 { 607 int error = 0; 608 ssize_t iaresid; 609 610 do { 611 int chunk; 612 613 /* 614 * Force `offset' to a multiple of MAXBSIZE except possibly 615 * for the first chunk, so that filesystems only need to 616 * write full blocks except possibly for the first and last 617 * chunks. 618 */ 619 chunk = MAXBSIZE - (uoff_t)offset % MAXBSIZE; 620 621 if (chunk > len) 622 chunk = len; 623 if (rw != UIO_READ && vp->v_type == VREG) 624 bwillwrite(); 625 iaresid = 0; 626 error = vn_rdwr(rw, vp, base, chunk, offset, segflg, 627 ioflg, active_cred, file_cred, &iaresid, td); 628 len -= chunk; /* aresid calc already includes length */ 629 if (error) 630 break; 631 offset += chunk; 632 base = (char *)base + chunk; 633 kern_yield(PRI_USER); 634 } while (len); 635 if (aresid) 636 *aresid = len + iaresid; 637 return (error); 638 } 639 640 off_t 641 foffset_lock(struct file *fp, int flags) 642 { 643 struct mtx *mtxp; 644 off_t res; 645 646 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed")); 647 648 #if OFF_MAX <= LONG_MAX 649 /* 650 * Caller only wants the current f_offset value. Assume that 651 * the long and shorter integer types reads are atomic. 652 */ 653 if ((flags & FOF_NOLOCK) != 0) 654 return (fp->f_offset); 655 #endif 656 657 /* 658 * According to McKusick the vn lock was protecting f_offset here. 659 * It is now protected by the FOFFSET_LOCKED flag. 660 */ 661 mtxp = mtx_pool_find(mtxpool_sleep, fp); 662 mtx_lock(mtxp); 663 if ((flags & FOF_NOLOCK) == 0) { 664 while (fp->f_vnread_flags & FOFFSET_LOCKED) { 665 fp->f_vnread_flags |= FOFFSET_LOCK_WAITING; 666 msleep(&fp->f_vnread_flags, mtxp, PUSER -1, 667 "vofflock", 0); 668 } 669 fp->f_vnread_flags |= FOFFSET_LOCKED; 670 } 671 res = fp->f_offset; 672 mtx_unlock(mtxp); 673 return (res); 674 } 675 676 void 677 foffset_unlock(struct file *fp, off_t val, int flags) 678 { 679 struct mtx *mtxp; 680 681 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed")); 682 683 #if OFF_MAX <= LONG_MAX 684 if ((flags & FOF_NOLOCK) != 0) { 685 if ((flags & FOF_NOUPDATE) == 0) 686 fp->f_offset = val; 687 if ((flags & FOF_NEXTOFF) != 0) 688 fp->f_nextoff = val; 689 return; 690 } 691 #endif 692 693 mtxp = mtx_pool_find(mtxpool_sleep, fp); 694 mtx_lock(mtxp); 695 if ((flags & FOF_NOUPDATE) == 0) 696 fp->f_offset = val; 697 if ((flags & FOF_NEXTOFF) != 0) 698 fp->f_nextoff = val; 699 if ((flags & FOF_NOLOCK) == 0) { 700 KASSERT((fp->f_vnread_flags & FOFFSET_LOCKED) != 0, 701 ("Lost FOFFSET_LOCKED")); 702 if (fp->f_vnread_flags & FOFFSET_LOCK_WAITING) 703 wakeup(&fp->f_vnread_flags); 704 fp->f_vnread_flags = 0; 705 } 706 mtx_unlock(mtxp); 707 } 708 709 void 710 foffset_lock_uio(struct file *fp, struct uio *uio, int flags) 711 { 712 713 if ((flags & FOF_OFFSET) == 0) 714 uio->uio_offset = foffset_lock(fp, flags); 715 } 716 717 void 718 foffset_unlock_uio(struct file *fp, struct uio *uio, int flags) 719 { 720 721 if ((flags & FOF_OFFSET) == 0) 722 foffset_unlock(fp, uio->uio_offset, flags); 723 } 724 725 static int 726 get_advice(struct file *fp, struct uio *uio) 727 { 728 struct mtx *mtxp; 729 int ret; 730 731 ret = POSIX_FADV_NORMAL; 732 if (fp->f_advice == NULL) 733 return (ret); 734 735 mtxp = mtx_pool_find(mtxpool_sleep, fp); 736 mtx_lock(mtxp); 737 if (uio->uio_offset >= fp->f_advice->fa_start && 738 uio->uio_offset + uio->uio_resid <= fp->f_advice->fa_end) 739 ret = fp->f_advice->fa_advice; 740 mtx_unlock(mtxp); 741 return (ret); 742 } 743 744 /* 745 * File table vnode read routine. 746 */ 747 static int 748 vn_read(fp, uio, active_cred, flags, td) 749 struct file *fp; 750 struct uio *uio; 751 struct ucred *active_cred; 752 int flags; 753 struct thread *td; 754 { 755 struct vnode *vp; 756 struct mtx *mtxp; 757 int error, ioflag; 758 int advice; 759 off_t offset, start, end; 760 761 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", 762 uio->uio_td, td)); 763 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET")); 764 vp = fp->f_vnode; 765 ioflag = 0; 766 if (fp->f_flag & FNONBLOCK) 767 ioflag |= IO_NDELAY; 768 if (fp->f_flag & O_DIRECT) 769 ioflag |= IO_DIRECT; 770 advice = get_advice(fp, uio); 771 vn_lock(vp, LK_SHARED | LK_RETRY); 772 773 switch (advice) { 774 case POSIX_FADV_NORMAL: 775 case POSIX_FADV_SEQUENTIAL: 776 case POSIX_FADV_NOREUSE: 777 ioflag |= sequential_heuristic(uio, fp); 778 break; 779 case POSIX_FADV_RANDOM: 780 /* Disable read-ahead for random I/O. */ 781 break; 782 } 783 offset = uio->uio_offset; 784 785 #ifdef MAC 786 error = mac_vnode_check_read(active_cred, fp->f_cred, vp); 787 if (error == 0) 788 #endif 789 error = VOP_READ(vp, uio, ioflag, fp->f_cred); 790 fp->f_nextoff = uio->uio_offset; 791 VOP_UNLOCK(vp, 0); 792 if (error == 0 && advice == POSIX_FADV_NOREUSE && 793 offset != uio->uio_offset) { 794 /* 795 * Use POSIX_FADV_DONTNEED to flush clean pages and 796 * buffers for the backing file after a 797 * POSIX_FADV_NOREUSE read(2). To optimize the common 798 * case of using POSIX_FADV_NOREUSE with sequential 799 * access, track the previous implicit DONTNEED 800 * request and grow this request to include the 801 * current read(2) in addition to the previous 802 * DONTNEED. With purely sequential access this will 803 * cause the DONTNEED requests to continously grow to 804 * cover all of the previously read regions of the 805 * file. This allows filesystem blocks that are 806 * accessed by multiple calls to read(2) to be flushed 807 * once the last read(2) finishes. 808 */ 809 start = offset; 810 end = uio->uio_offset - 1; 811 mtxp = mtx_pool_find(mtxpool_sleep, fp); 812 mtx_lock(mtxp); 813 if (fp->f_advice != NULL && 814 fp->f_advice->fa_advice == POSIX_FADV_NOREUSE) { 815 if (start != 0 && fp->f_advice->fa_prevend + 1 == start) 816 start = fp->f_advice->fa_prevstart; 817 else if (fp->f_advice->fa_prevstart != 0 && 818 fp->f_advice->fa_prevstart == end + 1) 819 end = fp->f_advice->fa_prevend; 820 fp->f_advice->fa_prevstart = start; 821 fp->f_advice->fa_prevend = end; 822 } 823 mtx_unlock(mtxp); 824 error = VOP_ADVISE(vp, start, end, POSIX_FADV_DONTNEED); 825 } 826 return (error); 827 } 828 829 /* 830 * File table vnode write routine. 831 */ 832 static int 833 vn_write(fp, uio, active_cred, flags, td) 834 struct file *fp; 835 struct uio *uio; 836 struct ucred *active_cred; 837 int flags; 838 struct thread *td; 839 { 840 struct vnode *vp; 841 struct mount *mp; 842 struct mtx *mtxp; 843 int error, ioflag, lock_flags; 844 int advice; 845 off_t offset, start, end; 846 847 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", 848 uio->uio_td, td)); 849 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET")); 850 vp = fp->f_vnode; 851 if (vp->v_type == VREG) 852 bwillwrite(); 853 ioflag = IO_UNIT; 854 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 855 ioflag |= IO_APPEND; 856 if (fp->f_flag & FNONBLOCK) 857 ioflag |= IO_NDELAY; 858 if (fp->f_flag & O_DIRECT) 859 ioflag |= IO_DIRECT; 860 if ((fp->f_flag & O_FSYNC) || 861 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS))) 862 ioflag |= IO_SYNC; 863 mp = NULL; 864 if (vp->v_type != VCHR && 865 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0) 866 goto unlock; 867 868 advice = get_advice(fp, uio); 869 870 if (MNT_SHARED_WRITES(mp) || 871 (mp == NULL && MNT_SHARED_WRITES(vp->v_mount))) { 872 lock_flags = LK_SHARED; 873 } else { 874 lock_flags = LK_EXCLUSIVE; 875 } 876 877 vn_lock(vp, lock_flags | LK_RETRY); 878 switch (advice) { 879 case POSIX_FADV_NORMAL: 880 case POSIX_FADV_SEQUENTIAL: 881 case POSIX_FADV_NOREUSE: 882 ioflag |= sequential_heuristic(uio, fp); 883 break; 884 case POSIX_FADV_RANDOM: 885 /* XXX: Is this correct? */ 886 break; 887 } 888 offset = uio->uio_offset; 889 890 #ifdef MAC 891 error = mac_vnode_check_write(active_cred, fp->f_cred, vp); 892 if (error == 0) 893 #endif 894 error = VOP_WRITE(vp, uio, ioflag, fp->f_cred); 895 fp->f_nextoff = uio->uio_offset; 896 VOP_UNLOCK(vp, 0); 897 if (vp->v_type != VCHR) 898 vn_finished_write(mp); 899 if (error == 0 && advice == POSIX_FADV_NOREUSE && 900 offset != uio->uio_offset) { 901 /* 902 * Use POSIX_FADV_DONTNEED to flush clean pages and 903 * buffers for the backing file after a 904 * POSIX_FADV_NOREUSE write(2). To optimize the 905 * common case of using POSIX_FADV_NOREUSE with 906 * sequential access, track the previous implicit 907 * DONTNEED request and grow this request to include 908 * the current write(2) in addition to the previous 909 * DONTNEED. With purely sequential access this will 910 * cause the DONTNEED requests to continously grow to 911 * cover all of the previously written regions of the 912 * file. 913 * 914 * Note that the blocks just written are almost 915 * certainly still dirty, so this only works when 916 * VOP_ADVISE() calls from subsequent writes push out 917 * the data written by this write(2) once the backing 918 * buffers are clean. However, as compared to forcing 919 * IO_DIRECT, this gives much saner behavior. Write 920 * clustering is still allowed, and clean pages are 921 * merely moved to the cache page queue rather than 922 * outright thrown away. This means a subsequent 923 * read(2) can still avoid hitting the disk if the 924 * pages have not been reclaimed. 925 * 926 * This does make POSIX_FADV_NOREUSE largely useless 927 * with non-sequential access. However, sequential 928 * access is the more common use case and the flag is 929 * merely advisory. 930 */ 931 start = offset; 932 end = uio->uio_offset - 1; 933 mtxp = mtx_pool_find(mtxpool_sleep, fp); 934 mtx_lock(mtxp); 935 if (fp->f_advice != NULL && 936 fp->f_advice->fa_advice == POSIX_FADV_NOREUSE) { 937 if (start != 0 && fp->f_advice->fa_prevend + 1 == start) 938 start = fp->f_advice->fa_prevstart; 939 else if (fp->f_advice->fa_prevstart != 0 && 940 fp->f_advice->fa_prevstart == end + 1) 941 end = fp->f_advice->fa_prevend; 942 fp->f_advice->fa_prevstart = start; 943 fp->f_advice->fa_prevend = end; 944 } 945 mtx_unlock(mtxp); 946 error = VOP_ADVISE(vp, start, end, POSIX_FADV_DONTNEED); 947 } 948 949 unlock: 950 return (error); 951 } 952 953 /* 954 * The vn_io_fault() is a wrapper around vn_read() and vn_write() to 955 * prevent the following deadlock: 956 * 957 * Assume that the thread A reads from the vnode vp1 into userspace 958 * buffer buf1 backed by the pages of vnode vp2. If a page in buf1 is 959 * currently not resident, then system ends up with the call chain 960 * vn_read() -> VOP_READ(vp1) -> uiomove() -> [Page Fault] -> 961 * vm_fault(buf1) -> vnode_pager_getpages(vp2) -> VOP_GETPAGES(vp2) 962 * which establishes lock order vp1->vn_lock, then vp2->vn_lock. 963 * If, at the same time, thread B reads from vnode vp2 into buffer buf2 964 * backed by the pages of vnode vp1, and some page in buf2 is not 965 * resident, we get a reversed order vp2->vn_lock, then vp1->vn_lock. 966 * 967 * To prevent the lock order reversal and deadlock, vn_io_fault() does 968 * not allow page faults to happen during VOP_READ() or VOP_WRITE(). 969 * Instead, it first tries to do the whole range i/o with pagefaults 970 * disabled. If all pages in the i/o buffer are resident and mapped, 971 * VOP will succeed (ignoring the genuine filesystem errors). 972 * Otherwise, we get back EFAULT, and vn_io_fault() falls back to do 973 * i/o in chunks, with all pages in the chunk prefaulted and held 974 * using vm_fault_quick_hold_pages(). 975 * 976 * Filesystems using this deadlock avoidance scheme should use the 977 * array of the held pages from uio, saved in the curthread->td_ma, 978 * instead of doing uiomove(). A helper function 979 * vn_io_fault_uiomove() converts uiomove request into 980 * uiomove_fromphys() over td_ma array. 981 * 982 * Since vnode locks do not cover the whole i/o anymore, rangelocks 983 * make the current i/o request atomic with respect to other i/os and 984 * truncations. 985 */ 986 987 /* 988 * Decode vn_io_fault_args and perform the corresponding i/o. 989 */ 990 static int 991 vn_io_fault_doio(struct vn_io_fault_args *args, struct uio *uio, 992 struct thread *td) 993 { 994 995 switch (args->kind) { 996 case VN_IO_FAULT_FOP: 997 return ((args->args.fop_args.doio)(args->args.fop_args.fp, 998 uio, args->cred, args->flags, td)); 999 case VN_IO_FAULT_VOP: 1000 if (uio->uio_rw == UIO_READ) { 1001 return (VOP_READ(args->args.vop_args.vp, uio, 1002 args->flags, args->cred)); 1003 } else if (uio->uio_rw == UIO_WRITE) { 1004 return (VOP_WRITE(args->args.vop_args.vp, uio, 1005 args->flags, args->cred)); 1006 } 1007 break; 1008 } 1009 panic("vn_io_fault_doio: unknown kind of io %d %d", args->kind, 1010 uio->uio_rw); 1011 } 1012 1013 /* 1014 * Common code for vn_io_fault(), agnostic to the kind of i/o request. 1015 * Uses vn_io_fault_doio() to make the call to an actual i/o function. 1016 * Used from vn_rdwr() and vn_io_fault(), which encode the i/o request 1017 * into args and call vn_io_fault1() to handle faults during the user 1018 * mode buffer accesses. 1019 */ 1020 static int 1021 vn_io_fault1(struct vnode *vp, struct uio *uio, struct vn_io_fault_args *args, 1022 struct thread *td) 1023 { 1024 vm_page_t ma[io_hold_cnt + 2]; 1025 struct uio *uio_clone, short_uio; 1026 struct iovec short_iovec[1]; 1027 vm_page_t *prev_td_ma; 1028 vm_prot_t prot; 1029 vm_offset_t addr, end; 1030 size_t len, resid; 1031 ssize_t adv; 1032 int error, cnt, save, saveheld, prev_td_ma_cnt; 1033 1034 prot = uio->uio_rw == UIO_READ ? VM_PROT_WRITE : VM_PROT_READ; 1035 1036 /* 1037 * The UFS follows IO_UNIT directive and replays back both 1038 * uio_offset and uio_resid if an error is encountered during the 1039 * operation. But, since the iovec may be already advanced, 1040 * uio is still in an inconsistent state. 1041 * 1042 * Cache a copy of the original uio, which is advanced to the redo 1043 * point using UIO_NOCOPY below. 1044 */ 1045 uio_clone = cloneuio(uio); 1046 resid = uio->uio_resid; 1047 1048 short_uio.uio_segflg = UIO_USERSPACE; 1049 short_uio.uio_rw = uio->uio_rw; 1050 short_uio.uio_td = uio->uio_td; 1051 1052 save = vm_fault_disable_pagefaults(); 1053 error = vn_io_fault_doio(args, uio, td); 1054 if (error != EFAULT) 1055 goto out; 1056 1057 atomic_add_long(&vn_io_faults_cnt, 1); 1058 uio_clone->uio_segflg = UIO_NOCOPY; 1059 uiomove(NULL, resid - uio->uio_resid, uio_clone); 1060 uio_clone->uio_segflg = uio->uio_segflg; 1061 1062 saveheld = curthread_pflags_set(TDP_UIOHELD); 1063 prev_td_ma = td->td_ma; 1064 prev_td_ma_cnt = td->td_ma_cnt; 1065 1066 while (uio_clone->uio_resid != 0) { 1067 len = uio_clone->uio_iov->iov_len; 1068 if (len == 0) { 1069 KASSERT(uio_clone->uio_iovcnt >= 1, 1070 ("iovcnt underflow")); 1071 uio_clone->uio_iov++; 1072 uio_clone->uio_iovcnt--; 1073 continue; 1074 } 1075 if (len > io_hold_cnt * PAGE_SIZE) 1076 len = io_hold_cnt * PAGE_SIZE; 1077 addr = (uintptr_t)uio_clone->uio_iov->iov_base; 1078 end = round_page(addr + len); 1079 if (end < addr) { 1080 error = EFAULT; 1081 break; 1082 } 1083 cnt = atop(end - trunc_page(addr)); 1084 /* 1085 * A perfectly misaligned address and length could cause 1086 * both the start and the end of the chunk to use partial 1087 * page. +2 accounts for such a situation. 1088 */ 1089 cnt = vm_fault_quick_hold_pages(&td->td_proc->p_vmspace->vm_map, 1090 addr, len, prot, ma, io_hold_cnt + 2); 1091 if (cnt == -1) { 1092 error = EFAULT; 1093 break; 1094 } 1095 short_uio.uio_iov = &short_iovec[0]; 1096 short_iovec[0].iov_base = (void *)addr; 1097 short_uio.uio_iovcnt = 1; 1098 short_uio.uio_resid = short_iovec[0].iov_len = len; 1099 short_uio.uio_offset = uio_clone->uio_offset; 1100 td->td_ma = ma; 1101 td->td_ma_cnt = cnt; 1102 1103 error = vn_io_fault_doio(args, &short_uio, td); 1104 vm_page_unhold_pages(ma, cnt); 1105 adv = len - short_uio.uio_resid; 1106 1107 uio_clone->uio_iov->iov_base = 1108 (char *)uio_clone->uio_iov->iov_base + adv; 1109 uio_clone->uio_iov->iov_len -= adv; 1110 uio_clone->uio_resid -= adv; 1111 uio_clone->uio_offset += adv; 1112 1113 uio->uio_resid -= adv; 1114 uio->uio_offset += adv; 1115 1116 if (error != 0 || adv == 0) 1117 break; 1118 } 1119 td->td_ma = prev_td_ma; 1120 td->td_ma_cnt = prev_td_ma_cnt; 1121 curthread_pflags_restore(saveheld); 1122 out: 1123 vm_fault_enable_pagefaults(save); 1124 free(uio_clone, M_IOV); 1125 return (error); 1126 } 1127 1128 static int 1129 vn_io_fault(struct file *fp, struct uio *uio, struct ucred *active_cred, 1130 int flags, struct thread *td) 1131 { 1132 fo_rdwr_t *doio; 1133 struct vnode *vp; 1134 void *rl_cookie; 1135 struct vn_io_fault_args args; 1136 int error; 1137 1138 doio = uio->uio_rw == UIO_READ ? vn_read : vn_write; 1139 vp = fp->f_vnode; 1140 foffset_lock_uio(fp, uio, flags); 1141 if (do_vn_io_fault(vp, uio)) { 1142 args.kind = VN_IO_FAULT_FOP; 1143 args.args.fop_args.fp = fp; 1144 args.args.fop_args.doio = doio; 1145 args.cred = active_cred; 1146 args.flags = flags | FOF_OFFSET; 1147 if (uio->uio_rw == UIO_READ) { 1148 rl_cookie = vn_rangelock_rlock(vp, uio->uio_offset, 1149 uio->uio_offset + uio->uio_resid); 1150 } else if ((fp->f_flag & O_APPEND) != 0 || 1151 (flags & FOF_OFFSET) == 0) { 1152 /* For appenders, punt and lock the whole range. */ 1153 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 1154 } else { 1155 rl_cookie = vn_rangelock_wlock(vp, uio->uio_offset, 1156 uio->uio_offset + uio->uio_resid); 1157 } 1158 error = vn_io_fault1(vp, uio, &args, td); 1159 vn_rangelock_unlock(vp, rl_cookie); 1160 } else { 1161 error = doio(fp, uio, active_cred, flags | FOF_OFFSET, td); 1162 } 1163 foffset_unlock_uio(fp, uio, flags); 1164 return (error); 1165 } 1166 1167 /* 1168 * Helper function to perform the requested uiomove operation using 1169 * the held pages for io->uio_iov[0].iov_base buffer instead of 1170 * copyin/copyout. Access to the pages with uiomove_fromphys() 1171 * instead of iov_base prevents page faults that could occur due to 1172 * pmap_collect() invalidating the mapping created by 1173 * vm_fault_quick_hold_pages(), or pageout daemon, page laundry or 1174 * object cleanup revoking the write access from page mappings. 1175 * 1176 * Filesystems specified MNTK_NO_IOPF shall use vn_io_fault_uiomove() 1177 * instead of plain uiomove(). 1178 */ 1179 int 1180 vn_io_fault_uiomove(char *data, int xfersize, struct uio *uio) 1181 { 1182 struct uio transp_uio; 1183 struct iovec transp_iov[1]; 1184 struct thread *td; 1185 size_t adv; 1186 int error, pgadv; 1187 1188 td = curthread; 1189 if ((td->td_pflags & TDP_UIOHELD) == 0 || 1190 uio->uio_segflg != UIO_USERSPACE) 1191 return (uiomove(data, xfersize, uio)); 1192 1193 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt)); 1194 transp_iov[0].iov_base = data; 1195 transp_uio.uio_iov = &transp_iov[0]; 1196 transp_uio.uio_iovcnt = 1; 1197 if (xfersize > uio->uio_resid) 1198 xfersize = uio->uio_resid; 1199 transp_uio.uio_resid = transp_iov[0].iov_len = xfersize; 1200 transp_uio.uio_offset = 0; 1201 transp_uio.uio_segflg = UIO_SYSSPACE; 1202 /* 1203 * Since transp_iov points to data, and td_ma page array 1204 * corresponds to original uio->uio_iov, we need to invert the 1205 * direction of the i/o operation as passed to 1206 * uiomove_fromphys(). 1207 */ 1208 switch (uio->uio_rw) { 1209 case UIO_WRITE: 1210 transp_uio.uio_rw = UIO_READ; 1211 break; 1212 case UIO_READ: 1213 transp_uio.uio_rw = UIO_WRITE; 1214 break; 1215 } 1216 transp_uio.uio_td = uio->uio_td; 1217 error = uiomove_fromphys(td->td_ma, 1218 ((vm_offset_t)uio->uio_iov->iov_base) & PAGE_MASK, 1219 xfersize, &transp_uio); 1220 adv = xfersize - transp_uio.uio_resid; 1221 pgadv = 1222 (((vm_offset_t)uio->uio_iov->iov_base + adv) >> PAGE_SHIFT) - 1223 (((vm_offset_t)uio->uio_iov->iov_base) >> PAGE_SHIFT); 1224 td->td_ma += pgadv; 1225 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt, 1226 pgadv)); 1227 td->td_ma_cnt -= pgadv; 1228 uio->uio_iov->iov_base = (char *)uio->uio_iov->iov_base + adv; 1229 uio->uio_iov->iov_len -= adv; 1230 uio->uio_resid -= adv; 1231 uio->uio_offset += adv; 1232 return (error); 1233 } 1234 1235 int 1236 vn_io_fault_pgmove(vm_page_t ma[], vm_offset_t offset, int xfersize, 1237 struct uio *uio) 1238 { 1239 struct thread *td; 1240 vm_offset_t iov_base; 1241 int cnt, pgadv; 1242 1243 td = curthread; 1244 if ((td->td_pflags & TDP_UIOHELD) == 0 || 1245 uio->uio_segflg != UIO_USERSPACE) 1246 return (uiomove_fromphys(ma, offset, xfersize, uio)); 1247 1248 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt)); 1249 cnt = xfersize > uio->uio_resid ? uio->uio_resid : xfersize; 1250 iov_base = (vm_offset_t)uio->uio_iov->iov_base; 1251 switch (uio->uio_rw) { 1252 case UIO_WRITE: 1253 pmap_copy_pages(td->td_ma, iov_base & PAGE_MASK, ma, 1254 offset, cnt); 1255 break; 1256 case UIO_READ: 1257 pmap_copy_pages(ma, offset, td->td_ma, iov_base & PAGE_MASK, 1258 cnt); 1259 break; 1260 } 1261 pgadv = ((iov_base + cnt) >> PAGE_SHIFT) - (iov_base >> PAGE_SHIFT); 1262 td->td_ma += pgadv; 1263 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt, 1264 pgadv)); 1265 td->td_ma_cnt -= pgadv; 1266 uio->uio_iov->iov_base = (char *)(iov_base + cnt); 1267 uio->uio_iov->iov_len -= cnt; 1268 uio->uio_resid -= cnt; 1269 uio->uio_offset += cnt; 1270 return (0); 1271 } 1272 1273 1274 /* 1275 * File table truncate routine. 1276 */ 1277 static int 1278 vn_truncate(struct file *fp, off_t length, struct ucred *active_cred, 1279 struct thread *td) 1280 { 1281 struct vattr vattr; 1282 struct mount *mp; 1283 struct vnode *vp; 1284 void *rl_cookie; 1285 int error; 1286 1287 vp = fp->f_vnode; 1288 1289 /* 1290 * Lock the whole range for truncation. Otherwise split i/o 1291 * might happen partly before and partly after the truncation. 1292 */ 1293 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 1294 error = vn_start_write(vp, &mp, V_WAIT | PCATCH); 1295 if (error) 1296 goto out1; 1297 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1298 if (vp->v_type == VDIR) { 1299 error = EISDIR; 1300 goto out; 1301 } 1302 #ifdef MAC 1303 error = mac_vnode_check_write(active_cred, fp->f_cred, vp); 1304 if (error) 1305 goto out; 1306 #endif 1307 error = vn_writechk(vp); 1308 if (error == 0) { 1309 VATTR_NULL(&vattr); 1310 vattr.va_size = length; 1311 error = VOP_SETATTR(vp, &vattr, fp->f_cred); 1312 } 1313 out: 1314 VOP_UNLOCK(vp, 0); 1315 vn_finished_write(mp); 1316 out1: 1317 vn_rangelock_unlock(vp, rl_cookie); 1318 return (error); 1319 } 1320 1321 /* 1322 * File table vnode stat routine. 1323 */ 1324 static int 1325 vn_statfile(fp, sb, active_cred, td) 1326 struct file *fp; 1327 struct stat *sb; 1328 struct ucred *active_cred; 1329 struct thread *td; 1330 { 1331 struct vnode *vp = fp->f_vnode; 1332 int error; 1333 1334 vn_lock(vp, LK_SHARED | LK_RETRY); 1335 error = vn_stat(vp, sb, active_cred, fp->f_cred, td); 1336 VOP_UNLOCK(vp, 0); 1337 1338 return (error); 1339 } 1340 1341 /* 1342 * Stat a vnode; implementation for the stat syscall 1343 */ 1344 int 1345 vn_stat(vp, sb, active_cred, file_cred, td) 1346 struct vnode *vp; 1347 register struct stat *sb; 1348 struct ucred *active_cred; 1349 struct ucred *file_cred; 1350 struct thread *td; 1351 { 1352 struct vattr vattr; 1353 register struct vattr *vap; 1354 int error; 1355 u_short mode; 1356 1357 #ifdef MAC 1358 error = mac_vnode_check_stat(active_cred, file_cred, vp); 1359 if (error) 1360 return (error); 1361 #endif 1362 1363 vap = &vattr; 1364 1365 /* 1366 * Initialize defaults for new and unusual fields, so that file 1367 * systems which don't support these fields don't need to know 1368 * about them. 1369 */ 1370 vap->va_birthtime.tv_sec = -1; 1371 vap->va_birthtime.tv_nsec = 0; 1372 vap->va_fsid = VNOVAL; 1373 vap->va_rdev = NODEV; 1374 1375 error = VOP_GETATTR(vp, vap, active_cred); 1376 if (error) 1377 return (error); 1378 1379 /* 1380 * Zero the spare stat fields 1381 */ 1382 bzero(sb, sizeof *sb); 1383 1384 /* 1385 * Copy from vattr table 1386 */ 1387 if (vap->va_fsid != VNOVAL) 1388 sb->st_dev = vap->va_fsid; 1389 else 1390 sb->st_dev = vp->v_mount->mnt_stat.f_fsid.val[0]; 1391 sb->st_ino = vap->va_fileid; 1392 mode = vap->va_mode; 1393 switch (vap->va_type) { 1394 case VREG: 1395 mode |= S_IFREG; 1396 break; 1397 case VDIR: 1398 mode |= S_IFDIR; 1399 break; 1400 case VBLK: 1401 mode |= S_IFBLK; 1402 break; 1403 case VCHR: 1404 mode |= S_IFCHR; 1405 break; 1406 case VLNK: 1407 mode |= S_IFLNK; 1408 break; 1409 case VSOCK: 1410 mode |= S_IFSOCK; 1411 break; 1412 case VFIFO: 1413 mode |= S_IFIFO; 1414 break; 1415 default: 1416 return (EBADF); 1417 }; 1418 sb->st_mode = mode; 1419 sb->st_nlink = vap->va_nlink; 1420 sb->st_uid = vap->va_uid; 1421 sb->st_gid = vap->va_gid; 1422 sb->st_rdev = vap->va_rdev; 1423 if (vap->va_size > OFF_MAX) 1424 return (EOVERFLOW); 1425 sb->st_size = vap->va_size; 1426 sb->st_atim = vap->va_atime; 1427 sb->st_mtim = vap->va_mtime; 1428 sb->st_ctim = vap->va_ctime; 1429 sb->st_birthtim = vap->va_birthtime; 1430 1431 /* 1432 * According to www.opengroup.org, the meaning of st_blksize is 1433 * "a filesystem-specific preferred I/O block size for this 1434 * object. In some filesystem types, this may vary from file 1435 * to file" 1436 * Use miminum/default of PAGE_SIZE (e.g. for VCHR). 1437 */ 1438 1439 sb->st_blksize = max(PAGE_SIZE, vap->va_blocksize); 1440 1441 sb->st_flags = vap->va_flags; 1442 if (priv_check(td, PRIV_VFS_GENERATION)) 1443 sb->st_gen = 0; 1444 else 1445 sb->st_gen = vap->va_gen; 1446 1447 sb->st_blocks = vap->va_bytes / S_BLKSIZE; 1448 return (0); 1449 } 1450 1451 /* 1452 * File table vnode ioctl routine. 1453 */ 1454 static int 1455 vn_ioctl(fp, com, data, active_cred, td) 1456 struct file *fp; 1457 u_long com; 1458 void *data; 1459 struct ucred *active_cred; 1460 struct thread *td; 1461 { 1462 struct vattr vattr; 1463 struct vnode *vp; 1464 int error; 1465 1466 vp = fp->f_vnode; 1467 switch (vp->v_type) { 1468 case VDIR: 1469 case VREG: 1470 switch (com) { 1471 case FIONREAD: 1472 vn_lock(vp, LK_SHARED | LK_RETRY); 1473 error = VOP_GETATTR(vp, &vattr, active_cred); 1474 VOP_UNLOCK(vp, 0); 1475 if (error == 0) 1476 *(int *)data = vattr.va_size - fp->f_offset; 1477 return (error); 1478 case FIONBIO: 1479 case FIOASYNC: 1480 return (0); 1481 default: 1482 return (VOP_IOCTL(vp, com, data, fp->f_flag, 1483 active_cred, td)); 1484 } 1485 default: 1486 return (ENOTTY); 1487 } 1488 } 1489 1490 /* 1491 * File table vnode poll routine. 1492 */ 1493 static int 1494 vn_poll(fp, events, active_cred, td) 1495 struct file *fp; 1496 int events; 1497 struct ucred *active_cred; 1498 struct thread *td; 1499 { 1500 struct vnode *vp; 1501 int error; 1502 1503 vp = fp->f_vnode; 1504 #ifdef MAC 1505 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1506 error = mac_vnode_check_poll(active_cred, fp->f_cred, vp); 1507 VOP_UNLOCK(vp, 0); 1508 if (!error) 1509 #endif 1510 1511 error = VOP_POLL(vp, events, fp->f_cred, td); 1512 return (error); 1513 } 1514 1515 /* 1516 * Acquire the requested lock and then check for validity. LK_RETRY 1517 * permits vn_lock to return doomed vnodes. 1518 */ 1519 int 1520 _vn_lock(struct vnode *vp, int flags, char *file, int line) 1521 { 1522 int error; 1523 1524 VNASSERT((flags & LK_TYPE_MASK) != 0, vp, 1525 ("vn_lock called with no locktype.")); 1526 do { 1527 #ifdef DEBUG_VFS_LOCKS 1528 KASSERT(vp->v_holdcnt != 0, 1529 ("vn_lock %p: zero hold count", vp)); 1530 #endif 1531 error = VOP_LOCK1(vp, flags, file, line); 1532 flags &= ~LK_INTERLOCK; /* Interlock is always dropped. */ 1533 KASSERT((flags & LK_RETRY) == 0 || error == 0, 1534 ("LK_RETRY set with incompatible flags (0x%x) or an error occured (%d)", 1535 flags, error)); 1536 /* 1537 * Callers specify LK_RETRY if they wish to get dead vnodes. 1538 * If RETRY is not set, we return ENOENT instead. 1539 */ 1540 if (error == 0 && vp->v_iflag & VI_DOOMED && 1541 (flags & LK_RETRY) == 0) { 1542 VOP_UNLOCK(vp, 0); 1543 error = ENOENT; 1544 break; 1545 } 1546 } while (flags & LK_RETRY && error != 0); 1547 return (error); 1548 } 1549 1550 /* 1551 * File table vnode close routine. 1552 */ 1553 static int 1554 vn_closefile(fp, td) 1555 struct file *fp; 1556 struct thread *td; 1557 { 1558 struct vnode *vp; 1559 struct flock lf; 1560 int error; 1561 1562 vp = fp->f_vnode; 1563 fp->f_ops = &badfileops; 1564 1565 if (fp->f_type == DTYPE_VNODE && fp->f_flag & FHASLOCK) 1566 vref(vp); 1567 1568 error = vn_close(vp, fp->f_flag, fp->f_cred, td); 1569 1570 if (fp->f_type == DTYPE_VNODE && fp->f_flag & FHASLOCK) { 1571 lf.l_whence = SEEK_SET; 1572 lf.l_start = 0; 1573 lf.l_len = 0; 1574 lf.l_type = F_UNLCK; 1575 (void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, F_FLOCK); 1576 vrele(vp); 1577 } 1578 return (error); 1579 } 1580 1581 static bool 1582 vn_suspendable_mp(struct mount *mp) 1583 { 1584 1585 return ((mp->mnt_kern_flag & MNTK_SUSPENDABLE) != 0); 1586 } 1587 1588 static bool 1589 vn_suspendable(struct vnode *vp, struct mount **mpp) 1590 { 1591 1592 if (vp != NULL) 1593 *mpp = vp->v_mount; 1594 if (*mpp == NULL) 1595 return (false); 1596 1597 return (vn_suspendable_mp(*mpp)); 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(vp, mpp, flags) 1644 struct vnode *vp; 1645 struct mount **mpp; 1646 int flags; 1647 { 1648 struct mount *mp; 1649 int error; 1650 1651 if (!vn_suspendable(vp, mpp)) 1652 return (0); 1653 1654 error = 0; 1655 /* 1656 * If a vnode is provided, get and return the mount point that 1657 * to which it will write. 1658 */ 1659 if (vp != NULL) { 1660 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) { 1661 *mpp = NULL; 1662 if (error != EOPNOTSUPP) 1663 return (error); 1664 return (0); 1665 } 1666 } 1667 if ((mp = *mpp) == NULL) 1668 return (0); 1669 1670 /* 1671 * VOP_GETWRITEMOUNT() returns with the mp refcount held through 1672 * a vfs_ref(). 1673 * As long as a vnode is not provided we need to acquire a 1674 * refcount for the provided mountpoint too, in order to 1675 * emulate a vfs_ref(). 1676 */ 1677 MNT_ILOCK(mp); 1678 if (vp == NULL) 1679 MNT_REF(mp); 1680 1681 return (vn_start_write_locked(mp, flags)); 1682 } 1683 1684 /* 1685 * Secondary suspension. Used by operations such as vop_inactive 1686 * routines that are needed by the higher level functions. These 1687 * are allowed to proceed until all the higher level functions have 1688 * completed (indicated by mnt_writeopcount dropping to zero). At that 1689 * time, these operations are halted until the suspension is over. 1690 */ 1691 int 1692 vn_start_secondary_write(vp, mpp, flags) 1693 struct vnode *vp; 1694 struct mount **mpp; 1695 int flags; 1696 { 1697 struct mount *mp; 1698 int error; 1699 1700 if (!vn_suspendable(vp, mpp)) 1701 return (0); 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 /* 1720 * VOP_GETWRITEMOUNT() returns with the mp refcount held through 1721 * a vfs_ref(). 1722 * As long as a vnode is not provided we need to acquire a 1723 * refcount for the provided mountpoint too, in order to 1724 * emulate a vfs_ref(). 1725 */ 1726 MNT_ILOCK(mp); 1727 if (vp == NULL) 1728 MNT_REF(mp); 1729 if ((mp->mnt_kern_flag & (MNTK_SUSPENDED | MNTK_SUSPEND2)) == 0) { 1730 mp->mnt_secondary_writes++; 1731 mp->mnt_secondary_accwrites++; 1732 MNT_IUNLOCK(mp); 1733 return (0); 1734 } 1735 if (flags & V_NOWAIT) { 1736 MNT_REL(mp); 1737 MNT_IUNLOCK(mp); 1738 return (EWOULDBLOCK); 1739 } 1740 /* 1741 * Wait for the suspension to finish. 1742 */ 1743 error = msleep(&mp->mnt_flag, MNT_MTX(mp), (PUSER - 1) | PDROP | 1744 ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0 ? (flags & PCATCH) : 0), 1745 "suspfs", 0); 1746 vfs_rel(mp); 1747 if (error == 0) 1748 goto retry; 1749 return (error); 1750 } 1751 1752 /* 1753 * Filesystem write operation has completed. If we are suspending and this 1754 * operation is the last one, notify the suspender that the suspension is 1755 * now in effect. 1756 */ 1757 void 1758 vn_finished_write(mp) 1759 struct mount *mp; 1760 { 1761 if (mp == NULL || !vn_suspendable_mp(mp)) 1762 return; 1763 MNT_ILOCK(mp); 1764 MNT_REL(mp); 1765 mp->mnt_writeopcount--; 1766 if (mp->mnt_writeopcount < 0) 1767 panic("vn_finished_write: neg cnt"); 1768 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && 1769 mp->mnt_writeopcount <= 0) 1770 wakeup(&mp->mnt_writeopcount); 1771 MNT_IUNLOCK(mp); 1772 } 1773 1774 1775 /* 1776 * Filesystem secondary write operation has completed. If we are 1777 * suspending and this operation is the last one, notify the suspender 1778 * that the suspension is now in effect. 1779 */ 1780 void 1781 vn_finished_secondary_write(mp) 1782 struct mount *mp; 1783 { 1784 if (mp == NULL || !vn_suspendable_mp(mp)) 1785 return; 1786 MNT_ILOCK(mp); 1787 MNT_REL(mp); 1788 mp->mnt_secondary_writes--; 1789 if (mp->mnt_secondary_writes < 0) 1790 panic("vn_finished_secondary_write: neg cnt"); 1791 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && 1792 mp->mnt_secondary_writes <= 0) 1793 wakeup(&mp->mnt_secondary_writes); 1794 MNT_IUNLOCK(mp); 1795 } 1796 1797 1798 1799 /* 1800 * Request a filesystem to suspend write operations. 1801 */ 1802 int 1803 vfs_write_suspend(struct mount *mp, int flags) 1804 { 1805 int error; 1806 1807 MPASS(vn_suspendable_mp(mp)); 1808 1809 MNT_ILOCK(mp); 1810 if (mp->mnt_susp_owner == curthread) { 1811 MNT_IUNLOCK(mp); 1812 return (EALREADY); 1813 } 1814 while (mp->mnt_kern_flag & MNTK_SUSPEND) 1815 msleep(&mp->mnt_flag, MNT_MTX(mp), PUSER - 1, "wsuspfs", 0); 1816 1817 /* 1818 * Unmount holds a write reference on the mount point. If we 1819 * own busy reference and drain for writers, we deadlock with 1820 * the reference draining in the unmount path. Callers of 1821 * vfs_write_suspend() must specify VS_SKIP_UNMOUNT if 1822 * vfs_busy() reference is owned and caller is not in the 1823 * unmount context. 1824 */ 1825 if ((flags & VS_SKIP_UNMOUNT) != 0 && 1826 (mp->mnt_kern_flag & MNTK_UNMOUNT) != 0) { 1827 MNT_IUNLOCK(mp); 1828 return (EBUSY); 1829 } 1830 1831 mp->mnt_kern_flag |= MNTK_SUSPEND; 1832 mp->mnt_susp_owner = curthread; 1833 if (mp->mnt_writeopcount > 0) 1834 (void) msleep(&mp->mnt_writeopcount, 1835 MNT_MTX(mp), (PUSER - 1)|PDROP, "suspwt", 0); 1836 else 1837 MNT_IUNLOCK(mp); 1838 if ((error = VFS_SYNC(mp, MNT_SUSPEND)) != 0) 1839 vfs_write_resume(mp, 0); 1840 return (error); 1841 } 1842 1843 /* 1844 * Request a filesystem to resume write operations. 1845 */ 1846 void 1847 vfs_write_resume(struct mount *mp, int flags) 1848 { 1849 1850 MPASS(vn_suspendable_mp(mp)); 1851 1852 MNT_ILOCK(mp); 1853 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { 1854 KASSERT(mp->mnt_susp_owner == curthread, ("mnt_susp_owner")); 1855 mp->mnt_kern_flag &= ~(MNTK_SUSPEND | MNTK_SUSPEND2 | 1856 MNTK_SUSPENDED); 1857 mp->mnt_susp_owner = NULL; 1858 wakeup(&mp->mnt_writeopcount); 1859 wakeup(&mp->mnt_flag); 1860 curthread->td_pflags &= ~TDP_IGNSUSP; 1861 if ((flags & VR_START_WRITE) != 0) { 1862 MNT_REF(mp); 1863 mp->mnt_writeopcount++; 1864 } 1865 MNT_IUNLOCK(mp); 1866 if ((flags & VR_NO_SUSPCLR) == 0) 1867 VFS_SUSP_CLEAN(mp); 1868 } else if ((flags & VR_START_WRITE) != 0) { 1869 MNT_REF(mp); 1870 vn_start_write_locked(mp, 0); 1871 } else { 1872 MNT_IUNLOCK(mp); 1873 } 1874 } 1875 1876 /* 1877 * Helper loop around vfs_write_suspend() for filesystem unmount VFS 1878 * methods. 1879 */ 1880 int 1881 vfs_write_suspend_umnt(struct mount *mp) 1882 { 1883 int error; 1884 1885 MPASS(vn_suspendable_mp(mp)); 1886 KASSERT((curthread->td_pflags & TDP_IGNSUSP) == 0, 1887 ("vfs_write_suspend_umnt: recursed")); 1888 1889 /* dounmount() already called vn_start_write(). */ 1890 for (;;) { 1891 vn_finished_write(mp); 1892 error = vfs_write_suspend(mp, 0); 1893 if (error != 0) { 1894 vn_start_write(NULL, &mp, V_WAIT); 1895 return (error); 1896 } 1897 MNT_ILOCK(mp); 1898 if ((mp->mnt_kern_flag & MNTK_SUSPENDED) != 0) 1899 break; 1900 MNT_IUNLOCK(mp); 1901 vn_start_write(NULL, &mp, V_WAIT); 1902 } 1903 mp->mnt_kern_flag &= ~(MNTK_SUSPENDED | MNTK_SUSPEND2); 1904 wakeup(&mp->mnt_flag); 1905 MNT_IUNLOCK(mp); 1906 curthread->td_pflags |= TDP_IGNSUSP; 1907 return (0); 1908 } 1909 1910 /* 1911 * Implement kqueues for files by translating it to vnode operation. 1912 */ 1913 static int 1914 vn_kqfilter(struct file *fp, struct knote *kn) 1915 { 1916 1917 return (VOP_KQFILTER(fp->f_vnode, kn)); 1918 } 1919 1920 /* 1921 * Simplified in-kernel wrapper calls for extended attribute access. 1922 * Both calls pass in a NULL credential, authorizing as "kernel" access. 1923 * Set IO_NODELOCKED in ioflg if the vnode is already locked. 1924 */ 1925 int 1926 vn_extattr_get(struct vnode *vp, int ioflg, int attrnamespace, 1927 const char *attrname, int *buflen, char *buf, struct thread *td) 1928 { 1929 struct uio auio; 1930 struct iovec iov; 1931 int error; 1932 1933 iov.iov_len = *buflen; 1934 iov.iov_base = buf; 1935 1936 auio.uio_iov = &iov; 1937 auio.uio_iovcnt = 1; 1938 auio.uio_rw = UIO_READ; 1939 auio.uio_segflg = UIO_SYSSPACE; 1940 auio.uio_td = td; 1941 auio.uio_offset = 0; 1942 auio.uio_resid = *buflen; 1943 1944 if ((ioflg & IO_NODELOCKED) == 0) 1945 vn_lock(vp, LK_SHARED | LK_RETRY); 1946 1947 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 1948 1949 /* authorize attribute retrieval as kernel */ 1950 error = VOP_GETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, NULL, 1951 td); 1952 1953 if ((ioflg & IO_NODELOCKED) == 0) 1954 VOP_UNLOCK(vp, 0); 1955 1956 if (error == 0) { 1957 *buflen = *buflen - auio.uio_resid; 1958 } 1959 1960 return (error); 1961 } 1962 1963 /* 1964 * XXX failure mode if partially written? 1965 */ 1966 int 1967 vn_extattr_set(struct vnode *vp, int ioflg, int attrnamespace, 1968 const char *attrname, int buflen, char *buf, struct thread *td) 1969 { 1970 struct uio auio; 1971 struct iovec iov; 1972 struct mount *mp; 1973 int error; 1974 1975 iov.iov_len = buflen; 1976 iov.iov_base = buf; 1977 1978 auio.uio_iov = &iov; 1979 auio.uio_iovcnt = 1; 1980 auio.uio_rw = UIO_WRITE; 1981 auio.uio_segflg = UIO_SYSSPACE; 1982 auio.uio_td = td; 1983 auio.uio_offset = 0; 1984 auio.uio_resid = buflen; 1985 1986 if ((ioflg & IO_NODELOCKED) == 0) { 1987 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) 1988 return (error); 1989 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1990 } 1991 1992 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 1993 1994 /* authorize attribute setting as kernel */ 1995 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, td); 1996 1997 if ((ioflg & IO_NODELOCKED) == 0) { 1998 vn_finished_write(mp); 1999 VOP_UNLOCK(vp, 0); 2000 } 2001 2002 return (error); 2003 } 2004 2005 int 2006 vn_extattr_rm(struct vnode *vp, int ioflg, int attrnamespace, 2007 const char *attrname, struct thread *td) 2008 { 2009 struct mount *mp; 2010 int error; 2011 2012 if ((ioflg & IO_NODELOCKED) == 0) { 2013 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) 2014 return (error); 2015 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2016 } 2017 2018 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 2019 2020 /* authorize attribute removal as kernel */ 2021 error = VOP_DELETEEXTATTR(vp, attrnamespace, attrname, NULL, td); 2022 if (error == EOPNOTSUPP) 2023 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, NULL, 2024 NULL, td); 2025 2026 if ((ioflg & IO_NODELOCKED) == 0) { 2027 vn_finished_write(mp); 2028 VOP_UNLOCK(vp, 0); 2029 } 2030 2031 return (error); 2032 } 2033 2034 static int 2035 vn_get_ino_alloc_vget(struct mount *mp, void *arg, int lkflags, 2036 struct vnode **rvp) 2037 { 2038 2039 return (VFS_VGET(mp, *(ino_t *)arg, lkflags, rvp)); 2040 } 2041 2042 int 2043 vn_vget_ino(struct vnode *vp, ino_t ino, int lkflags, struct vnode **rvp) 2044 { 2045 2046 return (vn_vget_ino_gen(vp, vn_get_ino_alloc_vget, &ino, 2047 lkflags, rvp)); 2048 } 2049 2050 int 2051 vn_vget_ino_gen(struct vnode *vp, vn_get_ino_t alloc, void *alloc_arg, 2052 int lkflags, struct vnode **rvp) 2053 { 2054 struct mount *mp; 2055 int ltype, error; 2056 2057 ASSERT_VOP_LOCKED(vp, "vn_vget_ino_get"); 2058 mp = vp->v_mount; 2059 ltype = VOP_ISLOCKED(vp); 2060 KASSERT(ltype == LK_EXCLUSIVE || ltype == LK_SHARED, 2061 ("vn_vget_ino: vp not locked")); 2062 error = vfs_busy(mp, MBF_NOWAIT); 2063 if (error != 0) { 2064 vfs_ref(mp); 2065 VOP_UNLOCK(vp, 0); 2066 error = vfs_busy(mp, 0); 2067 vn_lock(vp, ltype | LK_RETRY); 2068 vfs_rel(mp); 2069 if (error != 0) 2070 return (ENOENT); 2071 if (vp->v_iflag & VI_DOOMED) { 2072 vfs_unbusy(mp); 2073 return (ENOENT); 2074 } 2075 } 2076 VOP_UNLOCK(vp, 0); 2077 error = alloc(mp, alloc_arg, lkflags, rvp); 2078 vfs_unbusy(mp); 2079 if (*rvp != vp) 2080 vn_lock(vp, ltype | LK_RETRY); 2081 if (vp->v_iflag & VI_DOOMED) { 2082 if (error == 0) { 2083 if (*rvp == vp) 2084 vunref(vp); 2085 else 2086 vput(*rvp); 2087 } 2088 error = ENOENT; 2089 } 2090 return (error); 2091 } 2092 2093 int 2094 vn_rlimit_fsize(const struct vnode *vp, const struct uio *uio, 2095 const struct thread *td) 2096 { 2097 2098 if (vp->v_type != VREG || td == NULL) 2099 return (0); 2100 PROC_LOCK(td->td_proc); 2101 if ((uoff_t)uio->uio_offset + uio->uio_resid > 2102 lim_cur(td->td_proc, RLIMIT_FSIZE)) { 2103 kern_psignal(td->td_proc, SIGXFSZ); 2104 PROC_UNLOCK(td->td_proc); 2105 return (EFBIG); 2106 } 2107 PROC_UNLOCK(td->td_proc); 2108 return (0); 2109 } 2110 2111 int 2112 vn_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 2113 struct thread *td) 2114 { 2115 struct vnode *vp; 2116 2117 vp = fp->f_vnode; 2118 #ifdef AUDIT 2119 vn_lock(vp, LK_SHARED | LK_RETRY); 2120 AUDIT_ARG_VNODE1(vp); 2121 VOP_UNLOCK(vp, 0); 2122 #endif 2123 return (setfmode(td, active_cred, vp, mode)); 2124 } 2125 2126 int 2127 vn_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 2128 struct thread *td) 2129 { 2130 struct vnode *vp; 2131 2132 vp = fp->f_vnode; 2133 #ifdef AUDIT 2134 vn_lock(vp, LK_SHARED | LK_RETRY); 2135 AUDIT_ARG_VNODE1(vp); 2136 VOP_UNLOCK(vp, 0); 2137 #endif 2138 return (setfown(td, active_cred, vp, uid, gid)); 2139 } 2140 2141 void 2142 vn_pages_remove(struct vnode *vp, vm_pindex_t start, vm_pindex_t end) 2143 { 2144 vm_object_t object; 2145 2146 if ((object = vp->v_object) == NULL) 2147 return; 2148 VM_OBJECT_WLOCK(object); 2149 vm_object_page_remove(object, start, end, 0); 2150 VM_OBJECT_WUNLOCK(object); 2151 } 2152 2153 int 2154 vn_bmap_seekhole(struct vnode *vp, u_long cmd, off_t *off, struct ucred *cred) 2155 { 2156 struct vattr va; 2157 daddr_t bn, bnp; 2158 uint64_t bsize; 2159 off_t noff; 2160 int error; 2161 2162 KASSERT(cmd == FIOSEEKHOLE || cmd == FIOSEEKDATA, 2163 ("Wrong command %lu", cmd)); 2164 2165 if (vn_lock(vp, LK_SHARED) != 0) 2166 return (EBADF); 2167 if (vp->v_type != VREG) { 2168 error = ENOTTY; 2169 goto unlock; 2170 } 2171 error = VOP_GETATTR(vp, &va, cred); 2172 if (error != 0) 2173 goto unlock; 2174 noff = *off; 2175 if (noff >= va.va_size) { 2176 error = ENXIO; 2177 goto unlock; 2178 } 2179 bsize = vp->v_mount->mnt_stat.f_iosize; 2180 for (bn = noff / bsize; noff < va.va_size; bn++, noff += bsize) { 2181 error = VOP_BMAP(vp, bn, NULL, &bnp, NULL, NULL); 2182 if (error == EOPNOTSUPP) { 2183 error = ENOTTY; 2184 goto unlock; 2185 } 2186 if ((bnp == -1 && cmd == FIOSEEKHOLE) || 2187 (bnp != -1 && cmd == FIOSEEKDATA)) { 2188 noff = bn * bsize; 2189 if (noff < *off) 2190 noff = *off; 2191 goto unlock; 2192 } 2193 } 2194 if (noff > va.va_size) 2195 noff = va.va_size; 2196 /* noff == va.va_size. There is an implicit hole at the end of file. */ 2197 if (cmd == FIOSEEKDATA) 2198 error = ENXIO; 2199 unlock: 2200 VOP_UNLOCK(vp, 0); 2201 if (error == 0) 2202 *off = noff; 2203 return (error); 2204 } 2205 2206 int 2207 vn_seek(struct file *fp, off_t offset, int whence, struct thread *td) 2208 { 2209 struct ucred *cred; 2210 struct vnode *vp; 2211 struct vattr vattr; 2212 off_t foffset, size; 2213 int error, noneg; 2214 2215 cred = td->td_ucred; 2216 vp = fp->f_vnode; 2217 foffset = foffset_lock(fp, 0); 2218 noneg = (vp->v_type != VCHR); 2219 error = 0; 2220 switch (whence) { 2221 case L_INCR: 2222 if (noneg && 2223 (foffset < 0 || 2224 (offset > 0 && foffset > OFF_MAX - offset))) { 2225 error = EOVERFLOW; 2226 break; 2227 } 2228 offset += foffset; 2229 break; 2230 case L_XTND: 2231 vn_lock(vp, LK_SHARED | LK_RETRY); 2232 error = VOP_GETATTR(vp, &vattr, cred); 2233 VOP_UNLOCK(vp, 0); 2234 if (error) 2235 break; 2236 2237 /* 2238 * If the file references a disk device, then fetch 2239 * the media size and use that to determine the ending 2240 * offset. 2241 */ 2242 if (vattr.va_size == 0 && vp->v_type == VCHR && 2243 fo_ioctl(fp, DIOCGMEDIASIZE, &size, cred, td) == 0) 2244 vattr.va_size = size; 2245 if (noneg && 2246 (vattr.va_size > OFF_MAX || 2247 (offset > 0 && vattr.va_size > OFF_MAX - offset))) { 2248 error = EOVERFLOW; 2249 break; 2250 } 2251 offset += vattr.va_size; 2252 break; 2253 case L_SET: 2254 break; 2255 case SEEK_DATA: 2256 error = fo_ioctl(fp, FIOSEEKDATA, &offset, cred, td); 2257 break; 2258 case SEEK_HOLE: 2259 error = fo_ioctl(fp, FIOSEEKHOLE, &offset, cred, td); 2260 break; 2261 default: 2262 error = EINVAL; 2263 } 2264 if (error == 0 && noneg && offset < 0) 2265 error = EINVAL; 2266 if (error != 0) 2267 goto drop; 2268 VFS_KNOTE_UNLOCKED(vp, 0); 2269 td->td_uretoff.tdu_off = offset; 2270 drop: 2271 foffset_unlock(fp, offset, error != 0 ? FOF_NOUPDATE : 0); 2272 return (error); 2273 } 2274 2275 int 2276 vn_utimes_perm(struct vnode *vp, struct vattr *vap, struct ucred *cred, 2277 struct thread *td) 2278 { 2279 int error; 2280 2281 /* 2282 * Grant permission if the caller is the owner of the file, or 2283 * the super-user, or has ACL_WRITE_ATTRIBUTES permission on 2284 * on the file. If the time pointer is null, then write 2285 * permission on the file is also sufficient. 2286 * 2287 * From NFSv4.1, draft 21, 6.2.1.3.1, Discussion of Mask Attributes: 2288 * A user having ACL_WRITE_DATA or ACL_WRITE_ATTRIBUTES 2289 * will be allowed to set the times [..] to the current 2290 * server time. 2291 */ 2292 error = VOP_ACCESSX(vp, VWRITE_ATTRIBUTES, cred, td); 2293 if (error != 0 && (vap->va_vaflags & VA_UTIMES_NULL) != 0) 2294 error = VOP_ACCESS(vp, VWRITE, cred, td); 2295 return (error); 2296 } 2297 2298 int 2299 vn_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 2300 { 2301 struct vnode *vp; 2302 int error; 2303 2304 if (fp->f_type == DTYPE_FIFO) 2305 kif->kf_type = KF_TYPE_FIFO; 2306 else 2307 kif->kf_type = KF_TYPE_VNODE; 2308 vp = fp->f_vnode; 2309 vref(vp); 2310 FILEDESC_SUNLOCK(fdp); 2311 error = vn_fill_kinfo_vnode(vp, kif); 2312 vrele(vp); 2313 FILEDESC_SLOCK(fdp); 2314 return (error); 2315 } 2316 2317 int 2318 vn_fill_kinfo_vnode(struct vnode *vp, struct kinfo_file *kif) 2319 { 2320 struct vattr va; 2321 char *fullpath, *freepath; 2322 int error; 2323 2324 kif->kf_vnode_type = vntype_to_kinfo(vp->v_type); 2325 freepath = NULL; 2326 fullpath = "-"; 2327 error = vn_fullpath(curthread, vp, &fullpath, &freepath); 2328 if (error == 0) { 2329 strlcpy(kif->kf_path, fullpath, sizeof(kif->kf_path)); 2330 } 2331 if (freepath != NULL) 2332 free(freepath, M_TEMP); 2333 2334 /* 2335 * Retrieve vnode attributes. 2336 */ 2337 va.va_fsid = VNOVAL; 2338 va.va_rdev = NODEV; 2339 vn_lock(vp, LK_SHARED | LK_RETRY); 2340 error = VOP_GETATTR(vp, &va, curthread->td_ucred); 2341 VOP_UNLOCK(vp, 0); 2342 if (error != 0) 2343 return (error); 2344 if (va.va_fsid != VNOVAL) 2345 kif->kf_un.kf_file.kf_file_fsid = va.va_fsid; 2346 else 2347 kif->kf_un.kf_file.kf_file_fsid = 2348 vp->v_mount->mnt_stat.f_fsid.val[0]; 2349 kif->kf_un.kf_file.kf_file_fileid = va.va_fileid; 2350 kif->kf_un.kf_file.kf_file_mode = MAKEIMODE(va.va_type, va.va_mode); 2351 kif->kf_un.kf_file.kf_file_size = va.va_size; 2352 kif->kf_un.kf_file.kf_file_rdev = va.va_rdev; 2353 return (0); 2354 } 2355