Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/vfs_vnops.c
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1 /*- 2 * Copyright (c) 1982, 1986, 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Copyright (c) 2012 Konstantin Belousov <kib@FreeBSD.org> 11 * Copyright (c) 2013 The FreeBSD Foundation 12 * 13 * Portions of this software were developed by Konstantin Belousov 14 * under sponsorship from the FreeBSD Foundation. 15 * 16 * Redistribution and use in source and binary forms, with or without 17 * modification, are permitted provided that the following conditions 18 * are met: 19 * 1. Redistributions of source code must retain the above copyright 20 * notice, this list of conditions and the following disclaimer. 21 * 2. Redistributions in binary form must reproduce the above copyright 22 * notice, this list of conditions and the following disclaimer in the 23 * documentation and/or other materials provided with the distribution. 24 * 4. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 * 40 * @(#)vfs_vnops.c 8.2 (Berkeley) 1/21/94 41 */ 42 43 #include <sys/cdefs.h> 44 __FBSDID("$FreeBSD: releng/10.0/sys/kern/vfs_vnops.c 255510 2013-09-13 06:52:23Z kib $"); 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 73 #include <security/audit/audit.h> 74 #include <security/mac/mac_framework.h> 75 76 #include <vm/vm.h> 77 #include <vm/vm_extern.h> 78 #include <vm/pmap.h> 79 #include <vm/vm_map.h> 80 #include <vm/vm_object.h> 81 #include <vm/vm_page.h> 82 83 static fo_rdwr_t vn_read; 84 static fo_rdwr_t vn_write; 85 static fo_rdwr_t vn_io_fault; 86 static fo_truncate_t vn_truncate; 87 static fo_ioctl_t vn_ioctl; 88 static fo_poll_t vn_poll; 89 static fo_kqfilter_t vn_kqfilter; 90 static fo_stat_t vn_statfile; 91 static fo_close_t vn_closefile; 92 93 struct fileops vnops = { 94 .fo_read = vn_io_fault, 95 .fo_write = vn_io_fault, 96 .fo_truncate = vn_truncate, 97 .fo_ioctl = vn_ioctl, 98 .fo_poll = vn_poll, 99 .fo_kqfilter = vn_kqfilter, 100 .fo_stat = vn_statfile, 101 .fo_close = vn_closefile, 102 .fo_chmod = vn_chmod, 103 .fo_chown = vn_chown, 104 .fo_sendfile = vn_sendfile, 105 .fo_seek = vn_seek, 106 .fo_flags = DFLAG_PASSABLE | DFLAG_SEEKABLE 107 }; 108 109 int 110 vn_open(ndp, flagp, cmode, fp) 111 struct nameidata *ndp; 112 int *flagp, cmode; 113 struct file *fp; 114 { 115 struct thread *td = ndp->ni_cnd.cn_thread; 116 117 return (vn_open_cred(ndp, flagp, cmode, 0, td->td_ucred, fp)); 118 } 119 120 /* 121 * Common code for vnode open operations via a name lookup. 122 * Lookup the vnode and invoke VOP_CREATE if needed. 123 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine. 124 * 125 * Note that this does NOT free nameidata for the successful case, 126 * due to the NDINIT being done elsewhere. 127 */ 128 int 129 vn_open_cred(struct nameidata *ndp, int *flagp, int cmode, u_int vn_open_flags, 130 struct ucred *cred, struct file *fp) 131 { 132 struct vnode *vp; 133 struct mount *mp; 134 struct thread *td = ndp->ni_cnd.cn_thread; 135 struct vattr vat; 136 struct vattr *vap = &vat; 137 int fmode, error; 138 139 restart: 140 fmode = *flagp; 141 if (fmode & O_CREAT) { 142 ndp->ni_cnd.cn_nameiop = CREATE; 143 ndp->ni_cnd.cn_flags = ISOPEN | LOCKPARENT | LOCKLEAF; 144 if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0) 145 ndp->ni_cnd.cn_flags |= FOLLOW; 146 if (!(vn_open_flags & VN_OPEN_NOAUDIT)) 147 ndp->ni_cnd.cn_flags |= AUDITVNODE1; 148 if (vn_open_flags & VN_OPEN_NOCAPCHECK) 149 ndp->ni_cnd.cn_flags |= NOCAPCHECK; 150 bwillwrite(); 151 if ((error = namei(ndp)) != 0) 152 return (error); 153 if (ndp->ni_vp == NULL) { 154 VATTR_NULL(vap); 155 vap->va_type = VREG; 156 vap->va_mode = cmode; 157 if (fmode & O_EXCL) 158 vap->va_vaflags |= VA_EXCLUSIVE; 159 if (vn_start_write(ndp->ni_dvp, &mp, V_NOWAIT) != 0) { 160 NDFREE(ndp, NDF_ONLY_PNBUF); 161 vput(ndp->ni_dvp); 162 if ((error = vn_start_write(NULL, &mp, 163 V_XSLEEP | PCATCH)) != 0) 164 return (error); 165 goto restart; 166 } 167 #ifdef MAC 168 error = mac_vnode_check_create(cred, ndp->ni_dvp, 169 &ndp->ni_cnd, vap); 170 if (error == 0) 171 #endif 172 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp, 173 &ndp->ni_cnd, vap); 174 vput(ndp->ni_dvp); 175 vn_finished_write(mp); 176 if (error) { 177 NDFREE(ndp, NDF_ONLY_PNBUF); 178 return (error); 179 } 180 fmode &= ~O_TRUNC; 181 vp = ndp->ni_vp; 182 } else { 183 if (ndp->ni_dvp == ndp->ni_vp) 184 vrele(ndp->ni_dvp); 185 else 186 vput(ndp->ni_dvp); 187 ndp->ni_dvp = NULL; 188 vp = ndp->ni_vp; 189 if (fmode & O_EXCL) { 190 error = EEXIST; 191 goto bad; 192 } 193 fmode &= ~O_CREAT; 194 } 195 } else { 196 ndp->ni_cnd.cn_nameiop = LOOKUP; 197 ndp->ni_cnd.cn_flags = ISOPEN | 198 ((fmode & O_NOFOLLOW) ? NOFOLLOW : FOLLOW) | LOCKLEAF; 199 if (!(fmode & FWRITE)) 200 ndp->ni_cnd.cn_flags |= LOCKSHARED; 201 if (!(vn_open_flags & VN_OPEN_NOAUDIT)) 202 ndp->ni_cnd.cn_flags |= AUDITVNODE1; 203 if (vn_open_flags & VN_OPEN_NOCAPCHECK) 204 ndp->ni_cnd.cn_flags |= NOCAPCHECK; 205 if ((error = namei(ndp)) != 0) 206 return (error); 207 vp = ndp->ni_vp; 208 } 209 error = vn_open_vnode(vp, fmode, cred, td, fp); 210 if (error) 211 goto bad; 212 *flagp = fmode; 213 return (0); 214 bad: 215 NDFREE(ndp, NDF_ONLY_PNBUF); 216 vput(vp); 217 *flagp = fmode; 218 ndp->ni_vp = NULL; 219 return (error); 220 } 221 222 /* 223 * Common code for vnode open operations once a vnode is located. 224 * Check permissions, and call the VOP_OPEN routine. 225 */ 226 int 227 vn_open_vnode(struct vnode *vp, int fmode, struct ucred *cred, 228 struct thread *td, struct file *fp) 229 { 230 struct mount *mp; 231 accmode_t accmode; 232 struct flock lf; 233 int error, have_flock, lock_flags, type; 234 235 if (vp->v_type == VLNK) 236 return (EMLINK); 237 if (vp->v_type == VSOCK) 238 return (EOPNOTSUPP); 239 if (vp->v_type != VDIR && fmode & O_DIRECTORY) 240 return (ENOTDIR); 241 accmode = 0; 242 if (fmode & (FWRITE | O_TRUNC)) { 243 if (vp->v_type == VDIR) 244 return (EISDIR); 245 accmode |= VWRITE; 246 } 247 if (fmode & FREAD) 248 accmode |= VREAD; 249 if (fmode & FEXEC) 250 accmode |= VEXEC; 251 if ((fmode & O_APPEND) && (fmode & FWRITE)) 252 accmode |= VAPPEND; 253 #ifdef MAC 254 error = mac_vnode_check_open(cred, vp, accmode); 255 if (error) 256 return (error); 257 #endif 258 if ((fmode & O_CREAT) == 0) { 259 if (accmode & VWRITE) { 260 error = vn_writechk(vp); 261 if (error) 262 return (error); 263 } 264 if (accmode) { 265 error = VOP_ACCESS(vp, accmode, cred, td); 266 if (error) 267 return (error); 268 } 269 } 270 if (vp->v_type == VFIFO && VOP_ISLOCKED(vp) != LK_EXCLUSIVE) 271 vn_lock(vp, LK_UPGRADE | LK_RETRY); 272 if ((error = VOP_OPEN(vp, fmode, cred, td, fp)) != 0) 273 return (error); 274 275 if (fmode & (O_EXLOCK | O_SHLOCK)) { 276 KASSERT(fp != NULL, ("open with flock requires fp")); 277 lock_flags = VOP_ISLOCKED(vp); 278 VOP_UNLOCK(vp, 0); 279 lf.l_whence = SEEK_SET; 280 lf.l_start = 0; 281 lf.l_len = 0; 282 if (fmode & O_EXLOCK) 283 lf.l_type = F_WRLCK; 284 else 285 lf.l_type = F_RDLCK; 286 type = F_FLOCK; 287 if ((fmode & FNONBLOCK) == 0) 288 type |= F_WAIT; 289 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, type); 290 have_flock = (error == 0); 291 vn_lock(vp, lock_flags | LK_RETRY); 292 if (error == 0 && vp->v_iflag & VI_DOOMED) 293 error = ENOENT; 294 /* 295 * Another thread might have used this vnode as an 296 * executable while the vnode lock was dropped. 297 * Ensure the vnode is still able to be opened for 298 * writing after the lock has been obtained. 299 */ 300 if (error == 0 && accmode & VWRITE) 301 error = vn_writechk(vp); 302 if (error) { 303 VOP_UNLOCK(vp, 0); 304 if (have_flock) { 305 lf.l_whence = SEEK_SET; 306 lf.l_start = 0; 307 lf.l_len = 0; 308 lf.l_type = F_UNLCK; 309 (void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, 310 F_FLOCK); 311 } 312 vn_start_write(vp, &mp, V_WAIT); 313 vn_lock(vp, lock_flags | LK_RETRY); 314 (void)VOP_CLOSE(vp, fmode, cred, td); 315 vn_finished_write(mp); 316 return (error); 317 } 318 fp->f_flag |= FHASLOCK; 319 } 320 if (fmode & FWRITE) { 321 VOP_ADD_WRITECOUNT(vp, 1); 322 CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d", 323 __func__, vp, vp->v_writecount); 324 } 325 ASSERT_VOP_LOCKED(vp, "vn_open_vnode"); 326 return (0); 327 } 328 329 /* 330 * Check for write permissions on the specified vnode. 331 * Prototype text segments cannot be written. 332 */ 333 int 334 vn_writechk(vp) 335 register struct vnode *vp; 336 { 337 338 ASSERT_VOP_LOCKED(vp, "vn_writechk"); 339 /* 340 * If there's shared text associated with 341 * the vnode, try to free it up once. If 342 * we fail, we can't allow writing. 343 */ 344 if (VOP_IS_TEXT(vp)) 345 return (ETXTBSY); 346 347 return (0); 348 } 349 350 /* 351 * Vnode close call 352 */ 353 int 354 vn_close(vp, flags, file_cred, td) 355 register struct vnode *vp; 356 int flags; 357 struct ucred *file_cred; 358 struct thread *td; 359 { 360 struct mount *mp; 361 int error, lock_flags; 362 363 if (vp->v_type != VFIFO && !(flags & FWRITE) && vp->v_mount != NULL && 364 vp->v_mount->mnt_kern_flag & MNTK_EXTENDED_SHARED) 365 lock_flags = LK_SHARED; 366 else 367 lock_flags = LK_EXCLUSIVE; 368 369 vn_start_write(vp, &mp, V_WAIT); 370 vn_lock(vp, lock_flags | LK_RETRY); 371 if (flags & FWRITE) { 372 VNASSERT(vp->v_writecount > 0, vp, 373 ("vn_close: negative writecount")); 374 VOP_ADD_WRITECOUNT(vp, -1); 375 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d", 376 __func__, vp, vp->v_writecount); 377 } 378 error = VOP_CLOSE(vp, flags, file_cred, td); 379 vput(vp); 380 vn_finished_write(mp); 381 return (error); 382 } 383 384 /* 385 * Heuristic to detect sequential operation. 386 */ 387 static int 388 sequential_heuristic(struct uio *uio, struct file *fp) 389 { 390 391 if (atomic_load_acq_int(&(fp->f_flag)) & FRDAHEAD) 392 return (fp->f_seqcount << IO_SEQSHIFT); 393 394 /* 395 * Offset 0 is handled specially. open() sets f_seqcount to 1 so 396 * that the first I/O is normally considered to be slightly 397 * sequential. Seeking to offset 0 doesn't change sequentiality 398 * unless previous seeks have reduced f_seqcount to 0, in which 399 * case offset 0 is not special. 400 */ 401 if ((uio->uio_offset == 0 && fp->f_seqcount > 0) || 402 uio->uio_offset == fp->f_nextoff) { 403 /* 404 * f_seqcount is in units of fixed-size blocks so that it 405 * depends mainly on the amount of sequential I/O and not 406 * much on the number of sequential I/O's. The fixed size 407 * of 16384 is hard-coded here since it is (not quite) just 408 * a magic size that works well here. This size is more 409 * closely related to the best I/O size for real disks than 410 * to any block size used by software. 411 */ 412 fp->f_seqcount += howmany(uio->uio_resid, 16384); 413 if (fp->f_seqcount > IO_SEQMAX) 414 fp->f_seqcount = IO_SEQMAX; 415 return (fp->f_seqcount << IO_SEQSHIFT); 416 } 417 418 /* Not sequential. Quickly draw-down sequentiality. */ 419 if (fp->f_seqcount > 1) 420 fp->f_seqcount = 1; 421 else 422 fp->f_seqcount = 0; 423 return (0); 424 } 425 426 /* 427 * Package up an I/O request on a vnode into a uio and do it. 428 */ 429 int 430 vn_rdwr(enum uio_rw rw, struct vnode *vp, void *base, int len, off_t offset, 431 enum uio_seg segflg, int ioflg, struct ucred *active_cred, 432 struct ucred *file_cred, ssize_t *aresid, struct thread *td) 433 { 434 struct uio auio; 435 struct iovec aiov; 436 struct mount *mp; 437 struct ucred *cred; 438 void *rl_cookie; 439 int error, lock_flags; 440 441 auio.uio_iov = &aiov; 442 auio.uio_iovcnt = 1; 443 aiov.iov_base = base; 444 aiov.iov_len = len; 445 auio.uio_resid = len; 446 auio.uio_offset = offset; 447 auio.uio_segflg = segflg; 448 auio.uio_rw = rw; 449 auio.uio_td = td; 450 error = 0; 451 452 if ((ioflg & IO_NODELOCKED) == 0) { 453 if (rw == UIO_READ) { 454 rl_cookie = vn_rangelock_rlock(vp, offset, 455 offset + len); 456 } else { 457 rl_cookie = vn_rangelock_wlock(vp, offset, 458 offset + len); 459 } 460 mp = NULL; 461 if (rw == UIO_WRITE) { 462 if (vp->v_type != VCHR && 463 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) 464 != 0) 465 goto out; 466 if (MNT_SHARED_WRITES(mp) || 467 ((mp == NULL) && MNT_SHARED_WRITES(vp->v_mount))) 468 lock_flags = LK_SHARED; 469 else 470 lock_flags = LK_EXCLUSIVE; 471 } else 472 lock_flags = LK_SHARED; 473 vn_lock(vp, lock_flags | LK_RETRY); 474 } else 475 rl_cookie = NULL; 476 477 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 478 #ifdef MAC 479 if ((ioflg & IO_NOMACCHECK) == 0) { 480 if (rw == UIO_READ) 481 error = mac_vnode_check_read(active_cred, file_cred, 482 vp); 483 else 484 error = mac_vnode_check_write(active_cred, file_cred, 485 vp); 486 } 487 #endif 488 if (error == 0) { 489 if (file_cred != NULL) 490 cred = file_cred; 491 else 492 cred = active_cred; 493 if (rw == UIO_READ) 494 error = VOP_READ(vp, &auio, ioflg, cred); 495 else 496 error = VOP_WRITE(vp, &auio, ioflg, cred); 497 } 498 if (aresid) 499 *aresid = auio.uio_resid; 500 else 501 if (auio.uio_resid && error == 0) 502 error = EIO; 503 if ((ioflg & IO_NODELOCKED) == 0) { 504 VOP_UNLOCK(vp, 0); 505 if (mp != NULL) 506 vn_finished_write(mp); 507 } 508 out: 509 if (rl_cookie != NULL) 510 vn_rangelock_unlock(vp, rl_cookie); 511 return (error); 512 } 513 514 /* 515 * Package up an I/O request on a vnode into a uio and do it. The I/O 516 * request is split up into smaller chunks and we try to avoid saturating 517 * the buffer cache while potentially holding a vnode locked, so we 518 * check bwillwrite() before calling vn_rdwr(). We also call kern_yield() 519 * to give other processes a chance to lock the vnode (either other processes 520 * core'ing the same binary, or unrelated processes scanning the directory). 521 */ 522 int 523 vn_rdwr_inchunks(rw, vp, base, len, offset, segflg, ioflg, active_cred, 524 file_cred, aresid, td) 525 enum uio_rw rw; 526 struct vnode *vp; 527 void *base; 528 size_t len; 529 off_t offset; 530 enum uio_seg segflg; 531 int ioflg; 532 struct ucred *active_cred; 533 struct ucred *file_cred; 534 size_t *aresid; 535 struct thread *td; 536 { 537 int error = 0; 538 ssize_t iaresid; 539 540 do { 541 int chunk; 542 543 /* 544 * Force `offset' to a multiple of MAXBSIZE except possibly 545 * for the first chunk, so that filesystems only need to 546 * write full blocks except possibly for the first and last 547 * chunks. 548 */ 549 chunk = MAXBSIZE - (uoff_t)offset % MAXBSIZE; 550 551 if (chunk > len) 552 chunk = len; 553 if (rw != UIO_READ && vp->v_type == VREG) 554 bwillwrite(); 555 iaresid = 0; 556 error = vn_rdwr(rw, vp, base, chunk, offset, segflg, 557 ioflg, active_cred, file_cred, &iaresid, td); 558 len -= chunk; /* aresid calc already includes length */ 559 if (error) 560 break; 561 offset += chunk; 562 base = (char *)base + chunk; 563 kern_yield(PRI_USER); 564 } while (len); 565 if (aresid) 566 *aresid = len + iaresid; 567 return (error); 568 } 569 570 off_t 571 foffset_lock(struct file *fp, int flags) 572 { 573 struct mtx *mtxp; 574 off_t res; 575 576 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed")); 577 578 #if OFF_MAX <= LONG_MAX 579 /* 580 * Caller only wants the current f_offset value. Assume that 581 * the long and shorter integer types reads are atomic. 582 */ 583 if ((flags & FOF_NOLOCK) != 0) 584 return (fp->f_offset); 585 #endif 586 587 /* 588 * According to McKusick the vn lock was protecting f_offset here. 589 * It is now protected by the FOFFSET_LOCKED flag. 590 */ 591 mtxp = mtx_pool_find(mtxpool_sleep, fp); 592 mtx_lock(mtxp); 593 if ((flags & FOF_NOLOCK) == 0) { 594 while (fp->f_vnread_flags & FOFFSET_LOCKED) { 595 fp->f_vnread_flags |= FOFFSET_LOCK_WAITING; 596 msleep(&fp->f_vnread_flags, mtxp, PUSER -1, 597 "vofflock", 0); 598 } 599 fp->f_vnread_flags |= FOFFSET_LOCKED; 600 } 601 res = fp->f_offset; 602 mtx_unlock(mtxp); 603 return (res); 604 } 605 606 void 607 foffset_unlock(struct file *fp, off_t val, int flags) 608 { 609 struct mtx *mtxp; 610 611 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed")); 612 613 #if OFF_MAX <= LONG_MAX 614 if ((flags & FOF_NOLOCK) != 0) { 615 if ((flags & FOF_NOUPDATE) == 0) 616 fp->f_offset = val; 617 if ((flags & FOF_NEXTOFF) != 0) 618 fp->f_nextoff = val; 619 return; 620 } 621 #endif 622 623 mtxp = mtx_pool_find(mtxpool_sleep, fp); 624 mtx_lock(mtxp); 625 if ((flags & FOF_NOUPDATE) == 0) 626 fp->f_offset = val; 627 if ((flags & FOF_NEXTOFF) != 0) 628 fp->f_nextoff = val; 629 if ((flags & FOF_NOLOCK) == 0) { 630 KASSERT((fp->f_vnread_flags & FOFFSET_LOCKED) != 0, 631 ("Lost FOFFSET_LOCKED")); 632 if (fp->f_vnread_flags & FOFFSET_LOCK_WAITING) 633 wakeup(&fp->f_vnread_flags); 634 fp->f_vnread_flags = 0; 635 } 636 mtx_unlock(mtxp); 637 } 638 639 void 640 foffset_lock_uio(struct file *fp, struct uio *uio, int flags) 641 { 642 643 if ((flags & FOF_OFFSET) == 0) 644 uio->uio_offset = foffset_lock(fp, flags); 645 } 646 647 void 648 foffset_unlock_uio(struct file *fp, struct uio *uio, int flags) 649 { 650 651 if ((flags & FOF_OFFSET) == 0) 652 foffset_unlock(fp, uio->uio_offset, flags); 653 } 654 655 static int 656 get_advice(struct file *fp, struct uio *uio) 657 { 658 struct mtx *mtxp; 659 int ret; 660 661 ret = POSIX_FADV_NORMAL; 662 if (fp->f_advice == NULL) 663 return (ret); 664 665 mtxp = mtx_pool_find(mtxpool_sleep, fp); 666 mtx_lock(mtxp); 667 if (uio->uio_offset >= fp->f_advice->fa_start && 668 uio->uio_offset + uio->uio_resid <= fp->f_advice->fa_end) 669 ret = fp->f_advice->fa_advice; 670 mtx_unlock(mtxp); 671 return (ret); 672 } 673 674 /* 675 * File table vnode read routine. 676 */ 677 static int 678 vn_read(fp, uio, active_cred, flags, td) 679 struct file *fp; 680 struct uio *uio; 681 struct ucred *active_cred; 682 int flags; 683 struct thread *td; 684 { 685 struct vnode *vp; 686 struct mtx *mtxp; 687 int error, ioflag; 688 int advice; 689 off_t offset, start, end; 690 691 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", 692 uio->uio_td, td)); 693 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET")); 694 vp = fp->f_vnode; 695 ioflag = 0; 696 if (fp->f_flag & FNONBLOCK) 697 ioflag |= IO_NDELAY; 698 if (fp->f_flag & O_DIRECT) 699 ioflag |= IO_DIRECT; 700 advice = get_advice(fp, uio); 701 vn_lock(vp, LK_SHARED | LK_RETRY); 702 703 switch (advice) { 704 case POSIX_FADV_NORMAL: 705 case POSIX_FADV_SEQUENTIAL: 706 case POSIX_FADV_NOREUSE: 707 ioflag |= sequential_heuristic(uio, fp); 708 break; 709 case POSIX_FADV_RANDOM: 710 /* Disable read-ahead for random I/O. */ 711 break; 712 } 713 offset = uio->uio_offset; 714 715 #ifdef MAC 716 error = mac_vnode_check_read(active_cred, fp->f_cred, vp); 717 if (error == 0) 718 #endif 719 error = VOP_READ(vp, uio, ioflag, fp->f_cred); 720 fp->f_nextoff = uio->uio_offset; 721 VOP_UNLOCK(vp, 0); 722 if (error == 0 && advice == POSIX_FADV_NOREUSE && 723 offset != uio->uio_offset) { 724 /* 725 * Use POSIX_FADV_DONTNEED to flush clean pages and 726 * buffers for the backing file after a 727 * POSIX_FADV_NOREUSE read(2). To optimize the common 728 * case of using POSIX_FADV_NOREUSE with sequential 729 * access, track the previous implicit DONTNEED 730 * request and grow this request to include the 731 * current read(2) in addition to the previous 732 * DONTNEED. With purely sequential access this will 733 * cause the DONTNEED requests to continously grow to 734 * cover all of the previously read regions of the 735 * file. This allows filesystem blocks that are 736 * accessed by multiple calls to read(2) to be flushed 737 * once the last read(2) finishes. 738 */ 739 start = offset; 740 end = uio->uio_offset - 1; 741 mtxp = mtx_pool_find(mtxpool_sleep, fp); 742 mtx_lock(mtxp); 743 if (fp->f_advice != NULL && 744 fp->f_advice->fa_advice == POSIX_FADV_NOREUSE) { 745 if (start != 0 && fp->f_advice->fa_prevend + 1 == start) 746 start = fp->f_advice->fa_prevstart; 747 else if (fp->f_advice->fa_prevstart != 0 && 748 fp->f_advice->fa_prevstart == end + 1) 749 end = fp->f_advice->fa_prevend; 750 fp->f_advice->fa_prevstart = start; 751 fp->f_advice->fa_prevend = end; 752 } 753 mtx_unlock(mtxp); 754 error = VOP_ADVISE(vp, start, end, POSIX_FADV_DONTNEED); 755 } 756 return (error); 757 } 758 759 /* 760 * File table vnode write routine. 761 */ 762 static int 763 vn_write(fp, uio, active_cred, flags, td) 764 struct file *fp; 765 struct uio *uio; 766 struct ucred *active_cred; 767 int flags; 768 struct thread *td; 769 { 770 struct vnode *vp; 771 struct mount *mp; 772 struct mtx *mtxp; 773 int error, ioflag, lock_flags; 774 int advice; 775 off_t offset, start, end; 776 777 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", 778 uio->uio_td, td)); 779 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET")); 780 vp = fp->f_vnode; 781 if (vp->v_type == VREG) 782 bwillwrite(); 783 ioflag = IO_UNIT; 784 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 785 ioflag |= IO_APPEND; 786 if (fp->f_flag & FNONBLOCK) 787 ioflag |= IO_NDELAY; 788 if (fp->f_flag & O_DIRECT) 789 ioflag |= IO_DIRECT; 790 if ((fp->f_flag & O_FSYNC) || 791 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS))) 792 ioflag |= IO_SYNC; 793 mp = NULL; 794 if (vp->v_type != VCHR && 795 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0) 796 goto unlock; 797 798 advice = get_advice(fp, uio); 799 800 if (MNT_SHARED_WRITES(mp) || 801 (mp == NULL && MNT_SHARED_WRITES(vp->v_mount))) { 802 lock_flags = LK_SHARED; 803 } else { 804 lock_flags = LK_EXCLUSIVE; 805 } 806 807 vn_lock(vp, lock_flags | LK_RETRY); 808 switch (advice) { 809 case POSIX_FADV_NORMAL: 810 case POSIX_FADV_SEQUENTIAL: 811 case POSIX_FADV_NOREUSE: 812 ioflag |= sequential_heuristic(uio, fp); 813 break; 814 case POSIX_FADV_RANDOM: 815 /* XXX: Is this correct? */ 816 break; 817 } 818 offset = uio->uio_offset; 819 820 #ifdef MAC 821 error = mac_vnode_check_write(active_cred, fp->f_cred, vp); 822 if (error == 0) 823 #endif 824 error = VOP_WRITE(vp, uio, ioflag, fp->f_cred); 825 fp->f_nextoff = uio->uio_offset; 826 VOP_UNLOCK(vp, 0); 827 if (vp->v_type != VCHR) 828 vn_finished_write(mp); 829 if (error == 0 && advice == POSIX_FADV_NOREUSE && 830 offset != uio->uio_offset) { 831 /* 832 * Use POSIX_FADV_DONTNEED to flush clean pages and 833 * buffers for the backing file after a 834 * POSIX_FADV_NOREUSE write(2). To optimize the 835 * common case of using POSIX_FADV_NOREUSE with 836 * sequential access, track the previous implicit 837 * DONTNEED request and grow this request to include 838 * the current write(2) in addition to the previous 839 * DONTNEED. With purely sequential access this will 840 * cause the DONTNEED requests to continously grow to 841 * cover all of the previously written regions of the 842 * file. 843 * 844 * Note that the blocks just written are almost 845 * certainly still dirty, so this only works when 846 * VOP_ADVISE() calls from subsequent writes push out 847 * the data written by this write(2) once the backing 848 * buffers are clean. However, as compared to forcing 849 * IO_DIRECT, this gives much saner behavior. Write 850 * clustering is still allowed, and clean pages are 851 * merely moved to the cache page queue rather than 852 * outright thrown away. This means a subsequent 853 * read(2) can still avoid hitting the disk if the 854 * pages have not been reclaimed. 855 * 856 * This does make POSIX_FADV_NOREUSE largely useless 857 * with non-sequential access. However, sequential 858 * access is the more common use case and the flag is 859 * merely advisory. 860 */ 861 start = offset; 862 end = uio->uio_offset - 1; 863 mtxp = mtx_pool_find(mtxpool_sleep, fp); 864 mtx_lock(mtxp); 865 if (fp->f_advice != NULL && 866 fp->f_advice->fa_advice == POSIX_FADV_NOREUSE) { 867 if (start != 0 && fp->f_advice->fa_prevend + 1 == start) 868 start = fp->f_advice->fa_prevstart; 869 else if (fp->f_advice->fa_prevstart != 0 && 870 fp->f_advice->fa_prevstart == end + 1) 871 end = fp->f_advice->fa_prevend; 872 fp->f_advice->fa_prevstart = start; 873 fp->f_advice->fa_prevend = end; 874 } 875 mtx_unlock(mtxp); 876 error = VOP_ADVISE(vp, start, end, POSIX_FADV_DONTNEED); 877 } 878 879 unlock: 880 return (error); 881 } 882 883 static const int io_hold_cnt = 16; 884 static int vn_io_fault_enable = 1; 885 SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_enable, CTLFLAG_RW, 886 &vn_io_fault_enable, 0, "Enable vn_io_fault lock avoidance"); 887 static u_long vn_io_faults_cnt; 888 SYSCTL_ULONG(_debug, OID_AUTO, vn_io_faults, CTLFLAG_RD, 889 &vn_io_faults_cnt, 0, "Count of vn_io_fault lock avoidance triggers"); 890 891 /* 892 * The vn_io_fault() is a wrapper around vn_read() and vn_write() to 893 * prevent the following deadlock: 894 * 895 * Assume that the thread A reads from the vnode vp1 into userspace 896 * buffer buf1 backed by the pages of vnode vp2. If a page in buf1 is 897 * currently not resident, then system ends up with the call chain 898 * vn_read() -> VOP_READ(vp1) -> uiomove() -> [Page Fault] -> 899 * vm_fault(buf1) -> vnode_pager_getpages(vp2) -> VOP_GETPAGES(vp2) 900 * which establishes lock order vp1->vn_lock, then vp2->vn_lock. 901 * If, at the same time, thread B reads from vnode vp2 into buffer buf2 902 * backed by the pages of vnode vp1, and some page in buf2 is not 903 * resident, we get a reversed order vp2->vn_lock, then vp1->vn_lock. 904 * 905 * To prevent the lock order reversal and deadlock, vn_io_fault() does 906 * not allow page faults to happen during VOP_READ() or VOP_WRITE(). 907 * Instead, it first tries to do the whole range i/o with pagefaults 908 * disabled. If all pages in the i/o buffer are resident and mapped, 909 * VOP will succeed (ignoring the genuine filesystem errors). 910 * Otherwise, we get back EFAULT, and vn_io_fault() falls back to do 911 * i/o in chunks, with all pages in the chunk prefaulted and held 912 * using vm_fault_quick_hold_pages(). 913 * 914 * Filesystems using this deadlock avoidance scheme should use the 915 * array of the held pages from uio, saved in the curthread->td_ma, 916 * instead of doing uiomove(). A helper function 917 * vn_io_fault_uiomove() converts uiomove request into 918 * uiomove_fromphys() over td_ma array. 919 * 920 * Since vnode locks do not cover the whole i/o anymore, rangelocks 921 * make the current i/o request atomic with respect to other i/os and 922 * truncations. 923 */ 924 static int 925 vn_io_fault(struct file *fp, struct uio *uio, struct ucred *active_cred, 926 int flags, struct thread *td) 927 { 928 vm_page_t ma[io_hold_cnt + 2]; 929 struct uio *uio_clone, short_uio; 930 struct iovec short_iovec[1]; 931 fo_rdwr_t *doio; 932 struct vnode *vp; 933 void *rl_cookie; 934 struct mount *mp; 935 vm_page_t *prev_td_ma; 936 int cnt, error, save, saveheld, prev_td_ma_cnt; 937 vm_offset_t addr, end; 938 vm_prot_t prot; 939 size_t len, resid; 940 ssize_t adv; 941 942 if (uio->uio_rw == UIO_READ) 943 doio = vn_read; 944 else 945 doio = vn_write; 946 vp = fp->f_vnode; 947 foffset_lock_uio(fp, uio, flags); 948 949 if (uio->uio_segflg != UIO_USERSPACE || vp->v_type != VREG || 950 ((mp = vp->v_mount) != NULL && 951 (mp->mnt_kern_flag & MNTK_NO_IOPF) == 0) || 952 !vn_io_fault_enable) { 953 error = doio(fp, uio, active_cred, flags | FOF_OFFSET, td); 954 goto out_last; 955 } 956 957 /* 958 * The UFS follows IO_UNIT directive and replays back both 959 * uio_offset and uio_resid if an error is encountered during the 960 * operation. But, since the iovec may be already advanced, 961 * uio is still in an inconsistent state. 962 * 963 * Cache a copy of the original uio, which is advanced to the redo 964 * point using UIO_NOCOPY below. 965 */ 966 uio_clone = cloneuio(uio); 967 resid = uio->uio_resid; 968 969 short_uio.uio_segflg = UIO_USERSPACE; 970 short_uio.uio_rw = uio->uio_rw; 971 short_uio.uio_td = uio->uio_td; 972 973 if (uio->uio_rw == UIO_READ) { 974 prot = VM_PROT_WRITE; 975 rl_cookie = vn_rangelock_rlock(vp, uio->uio_offset, 976 uio->uio_offset + uio->uio_resid); 977 } else { 978 prot = VM_PROT_READ; 979 if ((fp->f_flag & O_APPEND) != 0 || (flags & FOF_OFFSET) == 0) 980 /* For appenders, punt and lock the whole range. */ 981 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 982 else 983 rl_cookie = vn_rangelock_wlock(vp, uio->uio_offset, 984 uio->uio_offset + uio->uio_resid); 985 } 986 987 save = vm_fault_disable_pagefaults(); 988 error = doio(fp, uio, active_cred, flags | FOF_OFFSET, td); 989 if (error != EFAULT) 990 goto out; 991 992 atomic_add_long(&vn_io_faults_cnt, 1); 993 uio_clone->uio_segflg = UIO_NOCOPY; 994 uiomove(NULL, resid - uio->uio_resid, uio_clone); 995 uio_clone->uio_segflg = uio->uio_segflg; 996 997 saveheld = curthread_pflags_set(TDP_UIOHELD); 998 prev_td_ma = td->td_ma; 999 prev_td_ma_cnt = td->td_ma_cnt; 1000 1001 while (uio_clone->uio_resid != 0) { 1002 len = uio_clone->uio_iov->iov_len; 1003 if (len == 0) { 1004 KASSERT(uio_clone->uio_iovcnt >= 1, 1005 ("iovcnt underflow")); 1006 uio_clone->uio_iov++; 1007 uio_clone->uio_iovcnt--; 1008 continue; 1009 } 1010 1011 addr = (vm_offset_t)uio_clone->uio_iov->iov_base; 1012 end = round_page(addr + len); 1013 cnt = howmany(end - trunc_page(addr), PAGE_SIZE); 1014 /* 1015 * A perfectly misaligned address and length could cause 1016 * both the start and the end of the chunk to use partial 1017 * page. +2 accounts for such a situation. 1018 */ 1019 if (cnt > io_hold_cnt + 2) { 1020 len = io_hold_cnt * PAGE_SIZE; 1021 KASSERT(howmany(round_page(addr + len) - 1022 trunc_page(addr), PAGE_SIZE) <= io_hold_cnt + 2, 1023 ("cnt overflow")); 1024 } 1025 cnt = vm_fault_quick_hold_pages(&td->td_proc->p_vmspace->vm_map, 1026 addr, len, prot, ma, io_hold_cnt + 2); 1027 if (cnt == -1) { 1028 error = EFAULT; 1029 break; 1030 } 1031 short_uio.uio_iov = &short_iovec[0]; 1032 short_iovec[0].iov_base = (void *)addr; 1033 short_uio.uio_iovcnt = 1; 1034 short_uio.uio_resid = short_iovec[0].iov_len = len; 1035 short_uio.uio_offset = uio_clone->uio_offset; 1036 td->td_ma = ma; 1037 td->td_ma_cnt = cnt; 1038 1039 error = doio(fp, &short_uio, active_cred, flags | FOF_OFFSET, 1040 td); 1041 vm_page_unhold_pages(ma, cnt); 1042 adv = len - short_uio.uio_resid; 1043 1044 uio_clone->uio_iov->iov_base = 1045 (char *)uio_clone->uio_iov->iov_base + adv; 1046 uio_clone->uio_iov->iov_len -= adv; 1047 uio_clone->uio_resid -= adv; 1048 uio_clone->uio_offset += adv; 1049 1050 uio->uio_resid -= adv; 1051 uio->uio_offset += adv; 1052 1053 if (error != 0 || adv == 0) 1054 break; 1055 } 1056 td->td_ma = prev_td_ma; 1057 td->td_ma_cnt = prev_td_ma_cnt; 1058 curthread_pflags_restore(saveheld); 1059 out: 1060 vm_fault_enable_pagefaults(save); 1061 vn_rangelock_unlock(vp, rl_cookie); 1062 free(uio_clone, M_IOV); 1063 out_last: 1064 foffset_unlock_uio(fp, uio, flags); 1065 return (error); 1066 } 1067 1068 /* 1069 * Helper function to perform the requested uiomove operation using 1070 * the held pages for io->uio_iov[0].iov_base buffer instead of 1071 * copyin/copyout. Access to the pages with uiomove_fromphys() 1072 * instead of iov_base prevents page faults that could occur due to 1073 * pmap_collect() invalidating the mapping created by 1074 * vm_fault_quick_hold_pages(), or pageout daemon, page laundry or 1075 * object cleanup revoking the write access from page mappings. 1076 * 1077 * Filesystems specified MNTK_NO_IOPF shall use vn_io_fault_uiomove() 1078 * instead of plain uiomove(). 1079 */ 1080 int 1081 vn_io_fault_uiomove(char *data, int xfersize, struct uio *uio) 1082 { 1083 struct uio transp_uio; 1084 struct iovec transp_iov[1]; 1085 struct thread *td; 1086 size_t adv; 1087 int error, pgadv; 1088 1089 td = curthread; 1090 if ((td->td_pflags & TDP_UIOHELD) == 0 || 1091 uio->uio_segflg != UIO_USERSPACE) 1092 return (uiomove(data, xfersize, uio)); 1093 1094 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt)); 1095 transp_iov[0].iov_base = data; 1096 transp_uio.uio_iov = &transp_iov[0]; 1097 transp_uio.uio_iovcnt = 1; 1098 if (xfersize > uio->uio_resid) 1099 xfersize = uio->uio_resid; 1100 transp_uio.uio_resid = transp_iov[0].iov_len = xfersize; 1101 transp_uio.uio_offset = 0; 1102 transp_uio.uio_segflg = UIO_SYSSPACE; 1103 /* 1104 * Since transp_iov points to data, and td_ma page array 1105 * corresponds to original uio->uio_iov, we need to invert the 1106 * direction of the i/o operation as passed to 1107 * uiomove_fromphys(). 1108 */ 1109 switch (uio->uio_rw) { 1110 case UIO_WRITE: 1111 transp_uio.uio_rw = UIO_READ; 1112 break; 1113 case UIO_READ: 1114 transp_uio.uio_rw = UIO_WRITE; 1115 break; 1116 } 1117 transp_uio.uio_td = uio->uio_td; 1118 error = uiomove_fromphys(td->td_ma, 1119 ((vm_offset_t)uio->uio_iov->iov_base) & PAGE_MASK, 1120 xfersize, &transp_uio); 1121 adv = xfersize - transp_uio.uio_resid; 1122 pgadv = 1123 (((vm_offset_t)uio->uio_iov->iov_base + adv) >> PAGE_SHIFT) - 1124 (((vm_offset_t)uio->uio_iov->iov_base) >> PAGE_SHIFT); 1125 td->td_ma += pgadv; 1126 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt, 1127 pgadv)); 1128 td->td_ma_cnt -= pgadv; 1129 uio->uio_iov->iov_base = (char *)uio->uio_iov->iov_base + adv; 1130 uio->uio_iov->iov_len -= adv; 1131 uio->uio_resid -= adv; 1132 uio->uio_offset += adv; 1133 return (error); 1134 } 1135 1136 int 1137 vn_io_fault_pgmove(vm_page_t ma[], vm_offset_t offset, int xfersize, 1138 struct uio *uio) 1139 { 1140 struct thread *td; 1141 vm_offset_t iov_base; 1142 int cnt, pgadv; 1143 1144 td = curthread; 1145 if ((td->td_pflags & TDP_UIOHELD) == 0 || 1146 uio->uio_segflg != UIO_USERSPACE) 1147 return (uiomove_fromphys(ma, offset, xfersize, uio)); 1148 1149 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt)); 1150 cnt = xfersize > uio->uio_resid ? uio->uio_resid : xfersize; 1151 iov_base = (vm_offset_t)uio->uio_iov->iov_base; 1152 switch (uio->uio_rw) { 1153 case UIO_WRITE: 1154 pmap_copy_pages(td->td_ma, iov_base & PAGE_MASK, ma, 1155 offset, cnt); 1156 break; 1157 case UIO_READ: 1158 pmap_copy_pages(ma, offset, td->td_ma, iov_base & PAGE_MASK, 1159 cnt); 1160 break; 1161 } 1162 pgadv = ((iov_base + cnt) >> PAGE_SHIFT) - (iov_base >> PAGE_SHIFT); 1163 td->td_ma += pgadv; 1164 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt, 1165 pgadv)); 1166 td->td_ma_cnt -= pgadv; 1167 uio->uio_iov->iov_base = (char *)(iov_base + cnt); 1168 uio->uio_iov->iov_len -= cnt; 1169 uio->uio_resid -= cnt; 1170 uio->uio_offset += cnt; 1171 return (0); 1172 } 1173 1174 1175 /* 1176 * File table truncate routine. 1177 */ 1178 static int 1179 vn_truncate(struct file *fp, off_t length, struct ucred *active_cred, 1180 struct thread *td) 1181 { 1182 struct vattr vattr; 1183 struct mount *mp; 1184 struct vnode *vp; 1185 void *rl_cookie; 1186 int error; 1187 1188 vp = fp->f_vnode; 1189 1190 /* 1191 * Lock the whole range for truncation. Otherwise split i/o 1192 * might happen partly before and partly after the truncation. 1193 */ 1194 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 1195 error = vn_start_write(vp, &mp, V_WAIT | PCATCH); 1196 if (error) 1197 goto out1; 1198 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1199 if (vp->v_type == VDIR) { 1200 error = EISDIR; 1201 goto out; 1202 } 1203 #ifdef MAC 1204 error = mac_vnode_check_write(active_cred, fp->f_cred, vp); 1205 if (error) 1206 goto out; 1207 #endif 1208 error = vn_writechk(vp); 1209 if (error == 0) { 1210 VATTR_NULL(&vattr); 1211 vattr.va_size = length; 1212 error = VOP_SETATTR(vp, &vattr, fp->f_cred); 1213 } 1214 out: 1215 VOP_UNLOCK(vp, 0); 1216 vn_finished_write(mp); 1217 out1: 1218 vn_rangelock_unlock(vp, rl_cookie); 1219 return (error); 1220 } 1221 1222 /* 1223 * File table vnode stat routine. 1224 */ 1225 static int 1226 vn_statfile(fp, sb, active_cred, td) 1227 struct file *fp; 1228 struct stat *sb; 1229 struct ucred *active_cred; 1230 struct thread *td; 1231 { 1232 struct vnode *vp = fp->f_vnode; 1233 int error; 1234 1235 vn_lock(vp, LK_SHARED | LK_RETRY); 1236 error = vn_stat(vp, sb, active_cred, fp->f_cred, td); 1237 VOP_UNLOCK(vp, 0); 1238 1239 return (error); 1240 } 1241 1242 /* 1243 * Stat a vnode; implementation for the stat syscall 1244 */ 1245 int 1246 vn_stat(vp, sb, active_cred, file_cred, td) 1247 struct vnode *vp; 1248 register struct stat *sb; 1249 struct ucred *active_cred; 1250 struct ucred *file_cred; 1251 struct thread *td; 1252 { 1253 struct vattr vattr; 1254 register struct vattr *vap; 1255 int error; 1256 u_short mode; 1257 1258 #ifdef MAC 1259 error = mac_vnode_check_stat(active_cred, file_cred, vp); 1260 if (error) 1261 return (error); 1262 #endif 1263 1264 vap = &vattr; 1265 1266 /* 1267 * Initialize defaults for new and unusual fields, so that file 1268 * systems which don't support these fields don't need to know 1269 * about them. 1270 */ 1271 vap->va_birthtime.tv_sec = -1; 1272 vap->va_birthtime.tv_nsec = 0; 1273 vap->va_fsid = VNOVAL; 1274 vap->va_rdev = NODEV; 1275 1276 error = VOP_GETATTR(vp, vap, active_cred); 1277 if (error) 1278 return (error); 1279 1280 /* 1281 * Zero the spare stat fields 1282 */ 1283 bzero(sb, sizeof *sb); 1284 1285 /* 1286 * Copy from vattr table 1287 */ 1288 if (vap->va_fsid != VNOVAL) 1289 sb->st_dev = vap->va_fsid; 1290 else 1291 sb->st_dev = vp->v_mount->mnt_stat.f_fsid.val[0]; 1292 sb->st_ino = vap->va_fileid; 1293 mode = vap->va_mode; 1294 switch (vap->va_type) { 1295 case VREG: 1296 mode |= S_IFREG; 1297 break; 1298 case VDIR: 1299 mode |= S_IFDIR; 1300 break; 1301 case VBLK: 1302 mode |= S_IFBLK; 1303 break; 1304 case VCHR: 1305 mode |= S_IFCHR; 1306 break; 1307 case VLNK: 1308 mode |= S_IFLNK; 1309 break; 1310 case VSOCK: 1311 mode |= S_IFSOCK; 1312 break; 1313 case VFIFO: 1314 mode |= S_IFIFO; 1315 break; 1316 default: 1317 return (EBADF); 1318 }; 1319 sb->st_mode = mode; 1320 sb->st_nlink = vap->va_nlink; 1321 sb->st_uid = vap->va_uid; 1322 sb->st_gid = vap->va_gid; 1323 sb->st_rdev = vap->va_rdev; 1324 if (vap->va_size > OFF_MAX) 1325 return (EOVERFLOW); 1326 sb->st_size = vap->va_size; 1327 sb->st_atim = vap->va_atime; 1328 sb->st_mtim = vap->va_mtime; 1329 sb->st_ctim = vap->va_ctime; 1330 sb->st_birthtim = vap->va_birthtime; 1331 1332 /* 1333 * According to www.opengroup.org, the meaning of st_blksize is 1334 * "a filesystem-specific preferred I/O block size for this 1335 * object. In some filesystem types, this may vary from file 1336 * to file" 1337 * Use miminum/default of PAGE_SIZE (e.g. for VCHR). 1338 */ 1339 1340 sb->st_blksize = max(PAGE_SIZE, vap->va_blocksize); 1341 1342 sb->st_flags = vap->va_flags; 1343 if (priv_check(td, PRIV_VFS_GENERATION)) 1344 sb->st_gen = 0; 1345 else 1346 sb->st_gen = vap->va_gen; 1347 1348 sb->st_blocks = vap->va_bytes / S_BLKSIZE; 1349 return (0); 1350 } 1351 1352 /* 1353 * File table vnode ioctl routine. 1354 */ 1355 static int 1356 vn_ioctl(fp, com, data, active_cred, td) 1357 struct file *fp; 1358 u_long com; 1359 void *data; 1360 struct ucred *active_cred; 1361 struct thread *td; 1362 { 1363 struct vattr vattr; 1364 struct vnode *vp; 1365 int error; 1366 1367 vp = fp->f_vnode; 1368 switch (vp->v_type) { 1369 case VDIR: 1370 case VREG: 1371 switch (com) { 1372 case FIONREAD: 1373 vn_lock(vp, LK_SHARED | LK_RETRY); 1374 error = VOP_GETATTR(vp, &vattr, active_cred); 1375 VOP_UNLOCK(vp, 0); 1376 if (error == 0) 1377 *(int *)data = vattr.va_size - fp->f_offset; 1378 return (error); 1379 case FIONBIO: 1380 case FIOASYNC: 1381 return (0); 1382 default: 1383 return (VOP_IOCTL(vp, com, data, fp->f_flag, 1384 active_cred, td)); 1385 } 1386 default: 1387 return (ENOTTY); 1388 } 1389 } 1390 1391 /* 1392 * File table vnode poll routine. 1393 */ 1394 static int 1395 vn_poll(fp, events, active_cred, td) 1396 struct file *fp; 1397 int events; 1398 struct ucred *active_cred; 1399 struct thread *td; 1400 { 1401 struct vnode *vp; 1402 int error; 1403 1404 vp = fp->f_vnode; 1405 #ifdef MAC 1406 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1407 error = mac_vnode_check_poll(active_cred, fp->f_cred, vp); 1408 VOP_UNLOCK(vp, 0); 1409 if (!error) 1410 #endif 1411 1412 error = VOP_POLL(vp, events, fp->f_cred, td); 1413 return (error); 1414 } 1415 1416 /* 1417 * Acquire the requested lock and then check for validity. LK_RETRY 1418 * permits vn_lock to return doomed vnodes. 1419 */ 1420 int 1421 _vn_lock(struct vnode *vp, int flags, char *file, int line) 1422 { 1423 int error; 1424 1425 VNASSERT((flags & LK_TYPE_MASK) != 0, vp, 1426 ("vn_lock called with no locktype.")); 1427 do { 1428 #ifdef DEBUG_VFS_LOCKS 1429 KASSERT(vp->v_holdcnt != 0, 1430 ("vn_lock %p: zero hold count", vp)); 1431 #endif 1432 error = VOP_LOCK1(vp, flags, file, line); 1433 flags &= ~LK_INTERLOCK; /* Interlock is always dropped. */ 1434 KASSERT((flags & LK_RETRY) == 0 || error == 0, 1435 ("LK_RETRY set with incompatible flags (0x%x) or an error occured (%d)", 1436 flags, error)); 1437 /* 1438 * Callers specify LK_RETRY if they wish to get dead vnodes. 1439 * If RETRY is not set, we return ENOENT instead. 1440 */ 1441 if (error == 0 && vp->v_iflag & VI_DOOMED && 1442 (flags & LK_RETRY) == 0) { 1443 VOP_UNLOCK(vp, 0); 1444 error = ENOENT; 1445 break; 1446 } 1447 } while (flags & LK_RETRY && error != 0); 1448 return (error); 1449 } 1450 1451 /* 1452 * File table vnode close routine. 1453 */ 1454 static int 1455 vn_closefile(fp, td) 1456 struct file *fp; 1457 struct thread *td; 1458 { 1459 struct vnode *vp; 1460 struct flock lf; 1461 int error; 1462 1463 vp = fp->f_vnode; 1464 fp->f_ops = &badfileops; 1465 1466 if (fp->f_type == DTYPE_VNODE && fp->f_flag & FHASLOCK) 1467 vref(vp); 1468 1469 error = vn_close(vp, fp->f_flag, fp->f_cred, td); 1470 1471 if (fp->f_type == DTYPE_VNODE && fp->f_flag & FHASLOCK) { 1472 lf.l_whence = SEEK_SET; 1473 lf.l_start = 0; 1474 lf.l_len = 0; 1475 lf.l_type = F_UNLCK; 1476 (void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, F_FLOCK); 1477 vrele(vp); 1478 } 1479 return (error); 1480 } 1481 1482 /* 1483 * Preparing to start a filesystem write operation. If the operation is 1484 * permitted, then we bump the count of operations in progress and 1485 * proceed. If a suspend request is in progress, we wait until the 1486 * suspension is over, and then proceed. 1487 */ 1488 static int 1489 vn_start_write_locked(struct mount *mp, int flags) 1490 { 1491 int error; 1492 1493 mtx_assert(MNT_MTX(mp), MA_OWNED); 1494 error = 0; 1495 1496 /* 1497 * Check on status of suspension. 1498 */ 1499 if ((curthread->td_pflags & TDP_IGNSUSP) == 0 || 1500 mp->mnt_susp_owner != curthread) { 1501 while ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { 1502 if (flags & V_NOWAIT) { 1503 error = EWOULDBLOCK; 1504 goto unlock; 1505 } 1506 error = msleep(&mp->mnt_flag, MNT_MTX(mp), 1507 (PUSER - 1) | (flags & PCATCH), "suspfs", 0); 1508 if (error) 1509 goto unlock; 1510 } 1511 } 1512 if (flags & V_XSLEEP) 1513 goto unlock; 1514 mp->mnt_writeopcount++; 1515 unlock: 1516 if (error != 0 || (flags & V_XSLEEP) != 0) 1517 MNT_REL(mp); 1518 MNT_IUNLOCK(mp); 1519 return (error); 1520 } 1521 1522 int 1523 vn_start_write(vp, mpp, flags) 1524 struct vnode *vp; 1525 struct mount **mpp; 1526 int flags; 1527 { 1528 struct mount *mp; 1529 int error; 1530 1531 error = 0; 1532 /* 1533 * If a vnode is provided, get and return the mount point that 1534 * to which it will write. 1535 */ 1536 if (vp != NULL) { 1537 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) { 1538 *mpp = NULL; 1539 if (error != EOPNOTSUPP) 1540 return (error); 1541 return (0); 1542 } 1543 } 1544 if ((mp = *mpp) == NULL) 1545 return (0); 1546 1547 /* 1548 * VOP_GETWRITEMOUNT() returns with the mp refcount held through 1549 * a vfs_ref(). 1550 * As long as a vnode is not provided we need to acquire a 1551 * refcount for the provided mountpoint too, in order to 1552 * emulate a vfs_ref(). 1553 */ 1554 MNT_ILOCK(mp); 1555 if (vp == NULL) 1556 MNT_REF(mp); 1557 1558 return (vn_start_write_locked(mp, flags)); 1559 } 1560 1561 /* 1562 * Secondary suspension. Used by operations such as vop_inactive 1563 * routines that are needed by the higher level functions. These 1564 * are allowed to proceed until all the higher level functions have 1565 * completed (indicated by mnt_writeopcount dropping to zero). At that 1566 * time, these operations are halted until the suspension is over. 1567 */ 1568 int 1569 vn_start_secondary_write(vp, mpp, flags) 1570 struct vnode *vp; 1571 struct mount **mpp; 1572 int flags; 1573 { 1574 struct mount *mp; 1575 int error; 1576 1577 retry: 1578 if (vp != NULL) { 1579 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) { 1580 *mpp = NULL; 1581 if (error != EOPNOTSUPP) 1582 return (error); 1583 return (0); 1584 } 1585 } 1586 /* 1587 * If we are not suspended or have not yet reached suspended 1588 * mode, then let the operation proceed. 1589 */ 1590 if ((mp = *mpp) == NULL) 1591 return (0); 1592 1593 /* 1594 * VOP_GETWRITEMOUNT() returns with the mp refcount held through 1595 * a vfs_ref(). 1596 * As long as a vnode is not provided we need to acquire a 1597 * refcount for the provided mountpoint too, in order to 1598 * emulate a vfs_ref(). 1599 */ 1600 MNT_ILOCK(mp); 1601 if (vp == NULL) 1602 MNT_REF(mp); 1603 if ((mp->mnt_kern_flag & (MNTK_SUSPENDED | MNTK_SUSPEND2)) == 0) { 1604 mp->mnt_secondary_writes++; 1605 mp->mnt_secondary_accwrites++; 1606 MNT_IUNLOCK(mp); 1607 return (0); 1608 } 1609 if (flags & V_NOWAIT) { 1610 MNT_REL(mp); 1611 MNT_IUNLOCK(mp); 1612 return (EWOULDBLOCK); 1613 } 1614 /* 1615 * Wait for the suspension to finish. 1616 */ 1617 error = msleep(&mp->mnt_flag, MNT_MTX(mp), 1618 (PUSER - 1) | (flags & PCATCH) | PDROP, "suspfs", 0); 1619 vfs_rel(mp); 1620 if (error == 0) 1621 goto retry; 1622 return (error); 1623 } 1624 1625 /* 1626 * Filesystem write operation has completed. If we are suspending and this 1627 * operation is the last one, notify the suspender that the suspension is 1628 * now in effect. 1629 */ 1630 void 1631 vn_finished_write(mp) 1632 struct mount *mp; 1633 { 1634 if (mp == NULL) 1635 return; 1636 MNT_ILOCK(mp); 1637 MNT_REL(mp); 1638 mp->mnt_writeopcount--; 1639 if (mp->mnt_writeopcount < 0) 1640 panic("vn_finished_write: neg cnt"); 1641 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && 1642 mp->mnt_writeopcount <= 0) 1643 wakeup(&mp->mnt_writeopcount); 1644 MNT_IUNLOCK(mp); 1645 } 1646 1647 1648 /* 1649 * Filesystem secondary write operation has completed. If we are 1650 * suspending and this operation is the last one, notify the suspender 1651 * that the suspension is now in effect. 1652 */ 1653 void 1654 vn_finished_secondary_write(mp) 1655 struct mount *mp; 1656 { 1657 if (mp == NULL) 1658 return; 1659 MNT_ILOCK(mp); 1660 MNT_REL(mp); 1661 mp->mnt_secondary_writes--; 1662 if (mp->mnt_secondary_writes < 0) 1663 panic("vn_finished_secondary_write: neg cnt"); 1664 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && 1665 mp->mnt_secondary_writes <= 0) 1666 wakeup(&mp->mnt_secondary_writes); 1667 MNT_IUNLOCK(mp); 1668 } 1669 1670 1671 1672 /* 1673 * Request a filesystem to suspend write operations. 1674 */ 1675 int 1676 vfs_write_suspend(struct mount *mp, int flags) 1677 { 1678 int error; 1679 1680 MNT_ILOCK(mp); 1681 if (mp->mnt_susp_owner == curthread) { 1682 MNT_IUNLOCK(mp); 1683 return (EALREADY); 1684 } 1685 while (mp->mnt_kern_flag & MNTK_SUSPEND) 1686 msleep(&mp->mnt_flag, MNT_MTX(mp), PUSER - 1, "wsuspfs", 0); 1687 1688 /* 1689 * Unmount holds a write reference on the mount point. If we 1690 * own busy reference and drain for writers, we deadlock with 1691 * the reference draining in the unmount path. Callers of 1692 * vfs_write_suspend() must specify VS_SKIP_UNMOUNT if 1693 * vfs_busy() reference is owned and caller is not in the 1694 * unmount context. 1695 */ 1696 if ((flags & VS_SKIP_UNMOUNT) != 0 && 1697 (mp->mnt_kern_flag & MNTK_UNMOUNT) != 0) { 1698 MNT_IUNLOCK(mp); 1699 return (EBUSY); 1700 } 1701 1702 mp->mnt_kern_flag |= MNTK_SUSPEND; 1703 mp->mnt_susp_owner = curthread; 1704 if (mp->mnt_writeopcount > 0) 1705 (void) msleep(&mp->mnt_writeopcount, 1706 MNT_MTX(mp), (PUSER - 1)|PDROP, "suspwt", 0); 1707 else 1708 MNT_IUNLOCK(mp); 1709 if ((error = VFS_SYNC(mp, MNT_SUSPEND)) != 0) 1710 vfs_write_resume(mp, 0); 1711 return (error); 1712 } 1713 1714 /* 1715 * Request a filesystem to resume write operations. 1716 */ 1717 void 1718 vfs_write_resume(struct mount *mp, int flags) 1719 { 1720 1721 MNT_ILOCK(mp); 1722 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { 1723 KASSERT(mp->mnt_susp_owner == curthread, ("mnt_susp_owner")); 1724 mp->mnt_kern_flag &= ~(MNTK_SUSPEND | MNTK_SUSPEND2 | 1725 MNTK_SUSPENDED); 1726 mp->mnt_susp_owner = NULL; 1727 wakeup(&mp->mnt_writeopcount); 1728 wakeup(&mp->mnt_flag); 1729 curthread->td_pflags &= ~TDP_IGNSUSP; 1730 if ((flags & VR_START_WRITE) != 0) { 1731 MNT_REF(mp); 1732 mp->mnt_writeopcount++; 1733 } 1734 MNT_IUNLOCK(mp); 1735 if ((flags & VR_NO_SUSPCLR) == 0) 1736 VFS_SUSP_CLEAN(mp); 1737 } else if ((flags & VR_START_WRITE) != 0) { 1738 MNT_REF(mp); 1739 vn_start_write_locked(mp, 0); 1740 } else { 1741 MNT_IUNLOCK(mp); 1742 } 1743 } 1744 1745 /* 1746 * Implement kqueues for files by translating it to vnode operation. 1747 */ 1748 static int 1749 vn_kqfilter(struct file *fp, struct knote *kn) 1750 { 1751 1752 return (VOP_KQFILTER(fp->f_vnode, kn)); 1753 } 1754 1755 /* 1756 * Simplified in-kernel wrapper calls for extended attribute access. 1757 * Both calls pass in a NULL credential, authorizing as "kernel" access. 1758 * Set IO_NODELOCKED in ioflg if the vnode is already locked. 1759 */ 1760 int 1761 vn_extattr_get(struct vnode *vp, int ioflg, int attrnamespace, 1762 const char *attrname, int *buflen, char *buf, struct thread *td) 1763 { 1764 struct uio auio; 1765 struct iovec iov; 1766 int error; 1767 1768 iov.iov_len = *buflen; 1769 iov.iov_base = buf; 1770 1771 auio.uio_iov = &iov; 1772 auio.uio_iovcnt = 1; 1773 auio.uio_rw = UIO_READ; 1774 auio.uio_segflg = UIO_SYSSPACE; 1775 auio.uio_td = td; 1776 auio.uio_offset = 0; 1777 auio.uio_resid = *buflen; 1778 1779 if ((ioflg & IO_NODELOCKED) == 0) 1780 vn_lock(vp, LK_SHARED | LK_RETRY); 1781 1782 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 1783 1784 /* authorize attribute retrieval as kernel */ 1785 error = VOP_GETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, NULL, 1786 td); 1787 1788 if ((ioflg & IO_NODELOCKED) == 0) 1789 VOP_UNLOCK(vp, 0); 1790 1791 if (error == 0) { 1792 *buflen = *buflen - auio.uio_resid; 1793 } 1794 1795 return (error); 1796 } 1797 1798 /* 1799 * XXX failure mode if partially written? 1800 */ 1801 int 1802 vn_extattr_set(struct vnode *vp, int ioflg, int attrnamespace, 1803 const char *attrname, int buflen, char *buf, struct thread *td) 1804 { 1805 struct uio auio; 1806 struct iovec iov; 1807 struct mount *mp; 1808 int error; 1809 1810 iov.iov_len = buflen; 1811 iov.iov_base = buf; 1812 1813 auio.uio_iov = &iov; 1814 auio.uio_iovcnt = 1; 1815 auio.uio_rw = UIO_WRITE; 1816 auio.uio_segflg = UIO_SYSSPACE; 1817 auio.uio_td = td; 1818 auio.uio_offset = 0; 1819 auio.uio_resid = buflen; 1820 1821 if ((ioflg & IO_NODELOCKED) == 0) { 1822 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) 1823 return (error); 1824 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1825 } 1826 1827 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 1828 1829 /* authorize attribute setting as kernel */ 1830 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, td); 1831 1832 if ((ioflg & IO_NODELOCKED) == 0) { 1833 vn_finished_write(mp); 1834 VOP_UNLOCK(vp, 0); 1835 } 1836 1837 return (error); 1838 } 1839 1840 int 1841 vn_extattr_rm(struct vnode *vp, int ioflg, int attrnamespace, 1842 const char *attrname, struct thread *td) 1843 { 1844 struct mount *mp; 1845 int error; 1846 1847 if ((ioflg & IO_NODELOCKED) == 0) { 1848 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) 1849 return (error); 1850 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1851 } 1852 1853 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 1854 1855 /* authorize attribute removal as kernel */ 1856 error = VOP_DELETEEXTATTR(vp, attrnamespace, attrname, NULL, td); 1857 if (error == EOPNOTSUPP) 1858 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, NULL, 1859 NULL, td); 1860 1861 if ((ioflg & IO_NODELOCKED) == 0) { 1862 vn_finished_write(mp); 1863 VOP_UNLOCK(vp, 0); 1864 } 1865 1866 return (error); 1867 } 1868 1869 int 1870 vn_vget_ino(struct vnode *vp, ino_t ino, int lkflags, struct vnode **rvp) 1871 { 1872 struct mount *mp; 1873 int ltype, error; 1874 1875 mp = vp->v_mount; 1876 ltype = VOP_ISLOCKED(vp); 1877 KASSERT(ltype == LK_EXCLUSIVE || ltype == LK_SHARED, 1878 ("vn_vget_ino: vp not locked")); 1879 error = vfs_busy(mp, MBF_NOWAIT); 1880 if (error != 0) { 1881 vfs_ref(mp); 1882 VOP_UNLOCK(vp, 0); 1883 error = vfs_busy(mp, 0); 1884 vn_lock(vp, ltype | LK_RETRY); 1885 vfs_rel(mp); 1886 if (error != 0) 1887 return (ENOENT); 1888 if (vp->v_iflag & VI_DOOMED) { 1889 vfs_unbusy(mp); 1890 return (ENOENT); 1891 } 1892 } 1893 VOP_UNLOCK(vp, 0); 1894 error = VFS_VGET(mp, ino, lkflags, rvp); 1895 vfs_unbusy(mp); 1896 vn_lock(vp, ltype | LK_RETRY); 1897 if (vp->v_iflag & VI_DOOMED) { 1898 if (error == 0) 1899 vput(*rvp); 1900 error = ENOENT; 1901 } 1902 return (error); 1903 } 1904 1905 int 1906 vn_rlimit_fsize(const struct vnode *vp, const struct uio *uio, 1907 const struct thread *td) 1908 { 1909 1910 if (vp->v_type != VREG || td == NULL) 1911 return (0); 1912 PROC_LOCK(td->td_proc); 1913 if ((uoff_t)uio->uio_offset + uio->uio_resid > 1914 lim_cur(td->td_proc, RLIMIT_FSIZE)) { 1915 kern_psignal(td->td_proc, SIGXFSZ); 1916 PROC_UNLOCK(td->td_proc); 1917 return (EFBIG); 1918 } 1919 PROC_UNLOCK(td->td_proc); 1920 return (0); 1921 } 1922 1923 int 1924 vn_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 1925 struct thread *td) 1926 { 1927 struct vnode *vp; 1928 1929 vp = fp->f_vnode; 1930 #ifdef AUDIT 1931 vn_lock(vp, LK_SHARED | LK_RETRY); 1932 AUDIT_ARG_VNODE1(vp); 1933 VOP_UNLOCK(vp, 0); 1934 #endif 1935 return (setfmode(td, active_cred, vp, mode)); 1936 } 1937 1938 int 1939 vn_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 1940 struct thread *td) 1941 { 1942 struct vnode *vp; 1943 1944 vp = fp->f_vnode; 1945 #ifdef AUDIT 1946 vn_lock(vp, LK_SHARED | LK_RETRY); 1947 AUDIT_ARG_VNODE1(vp); 1948 VOP_UNLOCK(vp, 0); 1949 #endif 1950 return (setfown(td, active_cred, vp, uid, gid)); 1951 } 1952 1953 void 1954 vn_pages_remove(struct vnode *vp, vm_pindex_t start, vm_pindex_t end) 1955 { 1956 vm_object_t object; 1957 1958 if ((object = vp->v_object) == NULL) 1959 return; 1960 VM_OBJECT_WLOCK(object); 1961 vm_object_page_remove(object, start, end, 0); 1962 VM_OBJECT_WUNLOCK(object); 1963 } 1964 1965 int 1966 vn_bmap_seekhole(struct vnode *vp, u_long cmd, off_t *off, struct ucred *cred) 1967 { 1968 struct vattr va; 1969 daddr_t bn, bnp; 1970 uint64_t bsize; 1971 off_t noff; 1972 int error; 1973 1974 KASSERT(cmd == FIOSEEKHOLE || cmd == FIOSEEKDATA, 1975 ("Wrong command %lu", cmd)); 1976 1977 if (vn_lock(vp, LK_SHARED) != 0) 1978 return (EBADF); 1979 if (vp->v_type != VREG) { 1980 error = ENOTTY; 1981 goto unlock; 1982 } 1983 error = VOP_GETATTR(vp, &va, cred); 1984 if (error != 0) 1985 goto unlock; 1986 noff = *off; 1987 if (noff >= va.va_size) { 1988 error = ENXIO; 1989 goto unlock; 1990 } 1991 bsize = vp->v_mount->mnt_stat.f_iosize; 1992 for (bn = noff / bsize; noff < va.va_size; bn++, noff += bsize) { 1993 error = VOP_BMAP(vp, bn, NULL, &bnp, NULL, NULL); 1994 if (error == EOPNOTSUPP) { 1995 error = ENOTTY; 1996 goto unlock; 1997 } 1998 if ((bnp == -1 && cmd == FIOSEEKHOLE) || 1999 (bnp != -1 && cmd == FIOSEEKDATA)) { 2000 noff = bn * bsize; 2001 if (noff < *off) 2002 noff = *off; 2003 goto unlock; 2004 } 2005 } 2006 if (noff > va.va_size) 2007 noff = va.va_size; 2008 /* noff == va.va_size. There is an implicit hole at the end of file. */ 2009 if (cmd == FIOSEEKDATA) 2010 error = ENXIO; 2011 unlock: 2012 VOP_UNLOCK(vp, 0); 2013 if (error == 0) 2014 *off = noff; 2015 return (error); 2016 } 2017 2018 int 2019 vn_seek(struct file *fp, off_t offset, int whence, struct thread *td) 2020 { 2021 struct ucred *cred; 2022 struct vnode *vp; 2023 struct vattr vattr; 2024 off_t foffset, size; 2025 int error, noneg; 2026 2027 cred = td->td_ucred; 2028 vp = fp->f_vnode; 2029 foffset = foffset_lock(fp, 0); 2030 noneg = (vp->v_type != VCHR); 2031 error = 0; 2032 switch (whence) { 2033 case L_INCR: 2034 if (noneg && 2035 (foffset < 0 || 2036 (offset > 0 && foffset > OFF_MAX - offset))) { 2037 error = EOVERFLOW; 2038 break; 2039 } 2040 offset += foffset; 2041 break; 2042 case L_XTND: 2043 vn_lock(vp, LK_SHARED | LK_RETRY); 2044 error = VOP_GETATTR(vp, &vattr, cred); 2045 VOP_UNLOCK(vp, 0); 2046 if (error) 2047 break; 2048 2049 /* 2050 * If the file references a disk device, then fetch 2051 * the media size and use that to determine the ending 2052 * offset. 2053 */ 2054 if (vattr.va_size == 0 && vp->v_type == VCHR && 2055 fo_ioctl(fp, DIOCGMEDIASIZE, &size, cred, td) == 0) 2056 vattr.va_size = size; 2057 if (noneg && 2058 (vattr.va_size > OFF_MAX || 2059 (offset > 0 && vattr.va_size > OFF_MAX - offset))) { 2060 error = EOVERFLOW; 2061 break; 2062 } 2063 offset += vattr.va_size; 2064 break; 2065 case L_SET: 2066 break; 2067 case SEEK_DATA: 2068 error = fo_ioctl(fp, FIOSEEKDATA, &offset, cred, td); 2069 break; 2070 case SEEK_HOLE: 2071 error = fo_ioctl(fp, FIOSEEKHOLE, &offset, cred, td); 2072 break; 2073 default: 2074 error = EINVAL; 2075 } 2076 if (error == 0 && noneg && offset < 0) 2077 error = EINVAL; 2078 if (error != 0) 2079 goto drop; 2080 VFS_KNOTE_UNLOCKED(vp, 0); 2081 *(off_t *)(td->td_retval) = offset; 2082 drop: 2083 foffset_unlock(fp, offset, error != 0 ? FOF_NOUPDATE : 0); 2084 return (error); 2085 }
Cache object: 888a7f15b1ed0f86a9d1aa837ac7d73b
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