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