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 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)vfs_vnops.c 8.2 (Berkeley) 1/21/94 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 #include "opt_mac.h" 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/fcntl.h> 45 #include <sys/file.h> 46 #include <sys/kdb.h> 47 #include <sys/stat.h> 48 #include <sys/priv.h> 49 #include <sys/proc.h> 50 #include <sys/limits.h> 51 #include <sys/lock.h> 52 #include <sys/mount.h> 53 #include <sys/mutex.h> 54 #include <sys/namei.h> 55 #include <sys/vnode.h> 56 #include <sys/bio.h> 57 #include <sys/buf.h> 58 #include <sys/filio.h> 59 #include <sys/sx.h> 60 #include <sys/ttycom.h> 61 #include <sys/conf.h> 62 #include <sys/syslog.h> 63 #include <sys/unistd.h> 64 65 #include <security/mac/mac_framework.h> 66 67 static fo_rdwr_t vn_read; 68 static fo_rdwr_t vn_write; 69 static fo_truncate_t vn_truncate; 70 static fo_ioctl_t vn_ioctl; 71 static fo_poll_t vn_poll; 72 static fo_kqfilter_t vn_kqfilter; 73 static fo_stat_t vn_statfile; 74 static fo_close_t vn_closefile; 75 76 struct fileops vnops = { 77 .fo_read = vn_read, 78 .fo_write = vn_write, 79 .fo_truncate = vn_truncate, 80 .fo_ioctl = vn_ioctl, 81 .fo_poll = vn_poll, 82 .fo_kqfilter = vn_kqfilter, 83 .fo_stat = vn_statfile, 84 .fo_close = vn_closefile, 85 .fo_flags = DFLAG_PASSABLE | DFLAG_SEEKABLE 86 }; 87 88 int 89 vn_open(ndp, flagp, cmode, fp) 90 struct nameidata *ndp; 91 int *flagp, cmode; 92 struct file *fp; 93 { 94 struct thread *td = ndp->ni_cnd.cn_thread; 95 96 return (vn_open_cred(ndp, flagp, cmode, td->td_ucred, fp)); 97 } 98 99 /* 100 * Common code for vnode open operations. 101 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine. 102 * 103 * Note that this does NOT free nameidata for the successful case, 104 * due to the NDINIT being done elsewhere. 105 */ 106 int 107 vn_open_cred(ndp, flagp, cmode, cred, fp) 108 struct nameidata *ndp; 109 int *flagp, cmode; 110 struct ucred *cred; 111 struct file *fp; 112 { 113 struct vnode *vp; 114 struct mount *mp; 115 struct thread *td = ndp->ni_cnd.cn_thread; 116 struct vattr vat; 117 struct vattr *vap = &vat; 118 int mode, fmode, error; 119 int vfslocked, mpsafe; 120 121 mpsafe = ndp->ni_cnd.cn_flags & MPSAFE; 122 restart: 123 vfslocked = 0; 124 fmode = *flagp; 125 if (fmode & O_CREAT) { 126 ndp->ni_cnd.cn_nameiop = CREATE; 127 ndp->ni_cnd.cn_flags = ISOPEN | LOCKPARENT | LOCKLEAF | 128 MPSAFE | AUDITVNODE1; 129 if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0) 130 ndp->ni_cnd.cn_flags |= FOLLOW; 131 bwillwrite(); 132 if ((error = namei(ndp)) != 0) 133 return (error); 134 vfslocked = NDHASGIANT(ndp); 135 if (!mpsafe) 136 ndp->ni_cnd.cn_flags &= ~MPSAFE; 137 if (ndp->ni_vp == NULL) { 138 VATTR_NULL(vap); 139 vap->va_type = VREG; 140 vap->va_mode = cmode; 141 if (fmode & O_EXCL) 142 vap->va_vaflags |= VA_EXCLUSIVE; 143 if (vn_start_write(ndp->ni_dvp, &mp, V_NOWAIT) != 0) { 144 NDFREE(ndp, NDF_ONLY_PNBUF); 145 vput(ndp->ni_dvp); 146 VFS_UNLOCK_GIANT(vfslocked); 147 if ((error = vn_start_write(NULL, &mp, 148 V_XSLEEP | PCATCH)) != 0) 149 return (error); 150 goto restart; 151 } 152 #ifdef MAC 153 error = mac_vnode_check_create(cred, ndp->ni_dvp, 154 &ndp->ni_cnd, vap); 155 if (error == 0) { 156 #endif 157 VOP_LEASE(ndp->ni_dvp, td, cred, LEASE_WRITE); 158 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp, 159 &ndp->ni_cnd, vap); 160 #ifdef MAC 161 } 162 #endif 163 vput(ndp->ni_dvp); 164 vn_finished_write(mp); 165 if (error) { 166 VFS_UNLOCK_GIANT(vfslocked); 167 NDFREE(ndp, NDF_ONLY_PNBUF); 168 return (error); 169 } 170 fmode &= ~O_TRUNC; 171 vp = ndp->ni_vp; 172 } else { 173 if (ndp->ni_dvp == ndp->ni_vp) 174 vrele(ndp->ni_dvp); 175 else 176 vput(ndp->ni_dvp); 177 ndp->ni_dvp = NULL; 178 vp = ndp->ni_vp; 179 if (fmode & O_EXCL) { 180 error = EEXIST; 181 goto bad; 182 } 183 fmode &= ~O_CREAT; 184 } 185 } else { 186 ndp->ni_cnd.cn_nameiop = LOOKUP; 187 ndp->ni_cnd.cn_flags = ISOPEN | 188 ((fmode & O_NOFOLLOW) ? NOFOLLOW : FOLLOW) | 189 LOCKLEAF | MPSAFE | AUDITVNODE1; 190 if ((error = namei(ndp)) != 0) 191 return (error); 192 if (!mpsafe) 193 ndp->ni_cnd.cn_flags &= ~MPSAFE; 194 vfslocked = NDHASGIANT(ndp); 195 vp = ndp->ni_vp; 196 } 197 if (vp->v_type == VLNK) { 198 error = EMLINK; 199 goto bad; 200 } 201 if (vp->v_type == VSOCK) { 202 error = EOPNOTSUPP; 203 goto bad; 204 } 205 mode = 0; 206 if (fmode & (FWRITE | O_TRUNC)) { 207 if (vp->v_type == VDIR) { 208 error = EISDIR; 209 goto bad; 210 } 211 mode |= VWRITE; 212 } 213 if (fmode & FREAD) 214 mode |= VREAD; 215 if (fmode & O_APPEND) 216 mode |= VAPPEND; 217 #ifdef MAC 218 error = mac_vnode_check_open(cred, vp, mode); 219 if (error) 220 goto bad; 221 #endif 222 if ((fmode & O_CREAT) == 0) { 223 if (mode & VWRITE) { 224 error = vn_writechk(vp); 225 if (error) 226 goto bad; 227 } 228 if (mode) { 229 error = VOP_ACCESS(vp, mode, cred, td); 230 if (error) 231 goto bad; 232 } 233 } 234 if ((error = VOP_OPEN(vp, fmode, cred, td, fp)) != 0) 235 goto bad; 236 237 if (fmode & FWRITE) 238 vp->v_writecount++; 239 *flagp = fmode; 240 ASSERT_VOP_ELOCKED(vp, "vn_open_cred"); 241 if (!mpsafe) 242 VFS_UNLOCK_GIANT(vfslocked); 243 return (0); 244 bad: 245 NDFREE(ndp, NDF_ONLY_PNBUF); 246 vput(vp); 247 VFS_UNLOCK_GIANT(vfslocked); 248 *flagp = fmode; 249 ndp->ni_vp = NULL; 250 return (error); 251 } 252 253 /* 254 * Check for write permissions on the specified vnode. 255 * Prototype text segments cannot be written. 256 */ 257 int 258 vn_writechk(vp) 259 register struct vnode *vp; 260 { 261 262 ASSERT_VOP_LOCKED(vp, "vn_writechk"); 263 /* 264 * If there's shared text associated with 265 * the vnode, try to free it up once. If 266 * we fail, we can't allow writing. 267 */ 268 if (vp->v_vflag & VV_TEXT) 269 return (ETXTBSY); 270 271 return (0); 272 } 273 274 /* 275 * Vnode close call 276 */ 277 int 278 vn_close(vp, flags, file_cred, td) 279 register struct vnode *vp; 280 int flags; 281 struct ucred *file_cred; 282 struct thread *td; 283 { 284 struct mount *mp; 285 int error; 286 287 VFS_ASSERT_GIANT(vp->v_mount); 288 289 vn_start_write(vp, &mp, V_WAIT); 290 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 291 if (flags & FWRITE) { 292 VNASSERT(vp->v_writecount > 0, vp, 293 ("vn_close: negative writecount")); 294 vp->v_writecount--; 295 } 296 error = VOP_CLOSE(vp, flags, file_cred, td); 297 vput(vp); 298 vn_finished_write(mp); 299 return (error); 300 } 301 302 /* 303 * Heuristic to detect sequential operation. 304 */ 305 static int 306 sequential_heuristic(struct uio *uio, struct file *fp) 307 { 308 309 /* 310 * Offset 0 is handled specially. open() sets f_seqcount to 1 so 311 * that the first I/O is normally considered to be slightly 312 * sequential. Seeking to offset 0 doesn't change sequentiality 313 * unless previous seeks have reduced f_seqcount to 0, in which 314 * case offset 0 is not special. 315 */ 316 if ((uio->uio_offset == 0 && fp->f_seqcount > 0) || 317 uio->uio_offset == fp->f_nextoff) { 318 /* 319 * f_seqcount is in units of fixed-size blocks so that it 320 * depends mainly on the amount of sequential I/O and not 321 * much on the number of sequential I/O's. The fixed size 322 * of 16384 is hard-coded here since it is (not quite) just 323 * a magic size that works well here. This size is more 324 * closely related to the best I/O size for real disks than 325 * to any block size used by software. 326 */ 327 fp->f_seqcount += howmany(uio->uio_resid, 16384); 328 if (fp->f_seqcount > IO_SEQMAX) 329 fp->f_seqcount = IO_SEQMAX; 330 return (fp->f_seqcount << IO_SEQSHIFT); 331 } 332 333 /* Not sequential. Quickly draw-down sequentiality. */ 334 if (fp->f_seqcount > 1) 335 fp->f_seqcount = 1; 336 else 337 fp->f_seqcount = 0; 338 return (0); 339 } 340 341 /* 342 * Package up an I/O request on a vnode into a uio and do it. 343 */ 344 int 345 vn_rdwr(rw, vp, base, len, offset, segflg, ioflg, active_cred, file_cred, 346 aresid, td) 347 enum uio_rw rw; 348 struct vnode *vp; 349 void *base; 350 int len; 351 off_t offset; 352 enum uio_seg segflg; 353 int ioflg; 354 struct ucred *active_cred; 355 struct ucred *file_cred; 356 int *aresid; 357 struct thread *td; 358 { 359 struct uio auio; 360 struct iovec aiov; 361 struct mount *mp; 362 struct ucred *cred; 363 int error; 364 365 VFS_ASSERT_GIANT(vp->v_mount); 366 367 if ((ioflg & IO_NODELOCKED) == 0) { 368 mp = NULL; 369 if (rw == UIO_WRITE) { 370 if (vp->v_type != VCHR && 371 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) 372 != 0) 373 return (error); 374 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 375 } else { 376 /* 377 * XXX This should be LK_SHARED but I don't trust VFS 378 * enough to leave it like that until it has been 379 * reviewed further. 380 */ 381 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 382 } 383 384 } 385 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 386 auio.uio_iov = &aiov; 387 auio.uio_iovcnt = 1; 388 aiov.iov_base = base; 389 aiov.iov_len = len; 390 auio.uio_resid = len; 391 auio.uio_offset = offset; 392 auio.uio_segflg = segflg; 393 auio.uio_rw = rw; 394 auio.uio_td = td; 395 error = 0; 396 #ifdef MAC 397 if ((ioflg & IO_NOMACCHECK) == 0) { 398 if (rw == UIO_READ) 399 error = mac_vnode_check_read(active_cred, file_cred, 400 vp); 401 else 402 error = mac_vnode_check_write(active_cred, file_cred, 403 vp); 404 } 405 #endif 406 if (error == 0) { 407 if (file_cred) 408 cred = file_cred; 409 else 410 cred = active_cred; 411 if (rw == UIO_READ) 412 error = VOP_READ(vp, &auio, ioflg, cred); 413 else 414 error = VOP_WRITE(vp, &auio, ioflg, cred); 415 } 416 if (aresid) 417 *aresid = auio.uio_resid; 418 else 419 if (auio.uio_resid && error == 0) 420 error = EIO; 421 if ((ioflg & IO_NODELOCKED) == 0) { 422 if (rw == UIO_WRITE && vp->v_type != VCHR) 423 vn_finished_write(mp); 424 VOP_UNLOCK(vp, 0); 425 } 426 return (error); 427 } 428 429 /* 430 * Package up an I/O request on a vnode into a uio and do it. The I/O 431 * request is split up into smaller chunks and we try to avoid saturating 432 * the buffer cache while potentially holding a vnode locked, so we 433 * check bwillwrite() before calling vn_rdwr(). We also call uio_yield() 434 * to give other processes a chance to lock the vnode (either other processes 435 * core'ing the same binary, or unrelated processes scanning the directory). 436 */ 437 int 438 vn_rdwr_inchunks(rw, vp, base, len, offset, segflg, ioflg, active_cred, 439 file_cred, aresid, td) 440 enum uio_rw rw; 441 struct vnode *vp; 442 void *base; 443 size_t len; 444 off_t offset; 445 enum uio_seg segflg; 446 int ioflg; 447 struct ucred *active_cred; 448 struct ucred *file_cred; 449 size_t *aresid; 450 struct thread *td; 451 { 452 int error = 0; 453 int iaresid; 454 455 VFS_ASSERT_GIANT(vp->v_mount); 456 457 do { 458 int chunk; 459 460 /* 461 * Force `offset' to a multiple of MAXBSIZE except possibly 462 * for the first chunk, so that filesystems only need to 463 * write full blocks except possibly for the first and last 464 * chunks. 465 */ 466 chunk = MAXBSIZE - (uoff_t)offset % MAXBSIZE; 467 468 if (chunk > len) 469 chunk = len; 470 if (rw != UIO_READ && vp->v_type == VREG) 471 bwillwrite(); 472 iaresid = 0; 473 error = vn_rdwr(rw, vp, base, chunk, offset, segflg, 474 ioflg, active_cred, file_cred, &iaresid, td); 475 len -= chunk; /* aresid calc already includes length */ 476 if (error) 477 break; 478 offset += chunk; 479 base = (char *)base + chunk; 480 uio_yield(); 481 } while (len); 482 if (aresid) 483 *aresid = len + iaresid; 484 return (error); 485 } 486 487 /* 488 * File table vnode read routine. 489 */ 490 static int 491 vn_read(fp, uio, active_cred, flags, td) 492 struct file *fp; 493 struct uio *uio; 494 struct ucred *active_cred; 495 struct thread *td; 496 int flags; 497 { 498 struct vnode *vp; 499 int error, ioflag; 500 struct mtx *mtxp; 501 int vfslocked; 502 503 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", 504 uio->uio_td, td)); 505 mtxp = NULL; 506 vp = fp->f_vnode; 507 ioflag = 0; 508 if (fp->f_flag & FNONBLOCK) 509 ioflag |= IO_NDELAY; 510 if (fp->f_flag & O_DIRECT) 511 ioflag |= IO_DIRECT; 512 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 513 VOP_LEASE(vp, td, fp->f_cred, LEASE_READ); 514 /* 515 * According to McKusick the vn lock was protecting f_offset here. 516 * It is now protected by the FOFFSET_LOCKED flag. 517 */ 518 if ((flags & FOF_OFFSET) == 0) { 519 mtxp = mtx_pool_find(mtxpool_sleep, fp); 520 mtx_lock(mtxp); 521 while(fp->f_vnread_flags & FOFFSET_LOCKED) { 522 fp->f_vnread_flags |= FOFFSET_LOCK_WAITING; 523 msleep(&fp->f_vnread_flags, mtxp, PUSER -1, 524 "vnread offlock", 0); 525 } 526 fp->f_vnread_flags |= FOFFSET_LOCKED; 527 mtx_unlock(mtxp); 528 vn_lock(vp, LK_SHARED | LK_RETRY); 529 uio->uio_offset = fp->f_offset; 530 } else 531 vn_lock(vp, LK_SHARED | LK_RETRY); 532 533 ioflag |= sequential_heuristic(uio, fp); 534 535 #ifdef MAC 536 error = mac_vnode_check_read(active_cred, fp->f_cred, vp); 537 if (error == 0) 538 #endif 539 error = VOP_READ(vp, uio, ioflag, fp->f_cred); 540 if ((flags & FOF_OFFSET) == 0) { 541 fp->f_offset = uio->uio_offset; 542 mtx_lock(mtxp); 543 if (fp->f_vnread_flags & FOFFSET_LOCK_WAITING) 544 wakeup(&fp->f_vnread_flags); 545 fp->f_vnread_flags = 0; 546 mtx_unlock(mtxp); 547 } 548 fp->f_nextoff = uio->uio_offset; 549 VOP_UNLOCK(vp, 0); 550 VFS_UNLOCK_GIANT(vfslocked); 551 return (error); 552 } 553 554 /* 555 * File table vnode write routine. 556 */ 557 static int 558 vn_write(fp, uio, active_cred, flags, td) 559 struct file *fp; 560 struct uio *uio; 561 struct ucred *active_cred; 562 struct thread *td; 563 int flags; 564 { 565 struct vnode *vp; 566 struct mount *mp; 567 int error, ioflag; 568 int vfslocked; 569 570 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", 571 uio->uio_td, td)); 572 vp = fp->f_vnode; 573 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 574 if (vp->v_type == VREG) 575 bwillwrite(); 576 ioflag = IO_UNIT; 577 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 578 ioflag |= IO_APPEND; 579 if (fp->f_flag & FNONBLOCK) 580 ioflag |= IO_NDELAY; 581 if (fp->f_flag & O_DIRECT) 582 ioflag |= IO_DIRECT; 583 if ((fp->f_flag & O_FSYNC) || 584 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS))) 585 ioflag |= IO_SYNC; 586 mp = NULL; 587 if (vp->v_type != VCHR && 588 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0) 589 goto unlock; 590 VOP_LEASE(vp, td, fp->f_cred, LEASE_WRITE); 591 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 592 if ((flags & FOF_OFFSET) == 0) 593 uio->uio_offset = fp->f_offset; 594 ioflag |= sequential_heuristic(uio, fp); 595 #ifdef MAC 596 error = mac_vnode_check_write(active_cred, fp->f_cred, vp); 597 if (error == 0) 598 #endif 599 error = VOP_WRITE(vp, uio, ioflag, fp->f_cred); 600 if ((flags & FOF_OFFSET) == 0) 601 fp->f_offset = uio->uio_offset; 602 fp->f_nextoff = uio->uio_offset; 603 VOP_UNLOCK(vp, 0); 604 if (vp->v_type != VCHR) 605 vn_finished_write(mp); 606 unlock: 607 VFS_UNLOCK_GIANT(vfslocked); 608 return (error); 609 } 610 611 /* 612 * File table truncate routine. 613 */ 614 static int 615 vn_truncate(fp, length, active_cred, td) 616 struct file *fp; 617 off_t length; 618 struct ucred *active_cred; 619 struct thread *td; 620 { 621 struct vattr vattr; 622 struct mount *mp; 623 struct vnode *vp; 624 int vfslocked; 625 int error; 626 627 vp = fp->f_vnode; 628 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 629 error = vn_start_write(vp, &mp, V_WAIT | PCATCH); 630 if (error) { 631 VFS_UNLOCK_GIANT(vfslocked); 632 return (error); 633 } 634 VOP_LEASE(vp, td, active_cred, LEASE_WRITE); 635 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 636 if (vp->v_type == VDIR) { 637 error = EISDIR; 638 goto out; 639 } 640 #ifdef MAC 641 error = mac_vnode_check_write(active_cred, fp->f_cred, vp); 642 if (error) 643 goto out; 644 #endif 645 error = vn_writechk(vp); 646 if (error == 0) { 647 VATTR_NULL(&vattr); 648 vattr.va_size = length; 649 error = VOP_SETATTR(vp, &vattr, fp->f_cred, td); 650 } 651 out: 652 VOP_UNLOCK(vp, 0); 653 vn_finished_write(mp); 654 VFS_UNLOCK_GIANT(vfslocked); 655 return (error); 656 } 657 658 /* 659 * File table vnode stat routine. 660 */ 661 static int 662 vn_statfile(fp, sb, active_cred, td) 663 struct file *fp; 664 struct stat *sb; 665 struct ucred *active_cred; 666 struct thread *td; 667 { 668 struct vnode *vp = fp->f_vnode; 669 int vfslocked; 670 int error; 671 672 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 673 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 674 error = vn_stat(vp, sb, active_cred, fp->f_cred, td); 675 VOP_UNLOCK(vp, 0); 676 VFS_UNLOCK_GIANT(vfslocked); 677 678 return (error); 679 } 680 681 /* 682 * Stat a vnode; implementation for the stat syscall 683 */ 684 int 685 vn_stat(vp, sb, active_cred, file_cred, td) 686 struct vnode *vp; 687 register struct stat *sb; 688 struct ucred *active_cred; 689 struct ucred *file_cred; 690 struct thread *td; 691 { 692 struct vattr vattr; 693 register struct vattr *vap; 694 int error; 695 u_short mode; 696 697 #ifdef MAC 698 error = mac_vnode_check_stat(active_cred, file_cred, vp); 699 if (error) 700 return (error); 701 #endif 702 703 vap = &vattr; 704 error = VOP_GETATTR(vp, vap, active_cred, td); 705 if (error) 706 return (error); 707 708 /* 709 * Zero the spare stat fields 710 */ 711 bzero(sb, sizeof *sb); 712 713 /* 714 * Copy from vattr table 715 */ 716 if (vap->va_fsid != VNOVAL) 717 sb->st_dev = vap->va_fsid; 718 else 719 sb->st_dev = vp->v_mount->mnt_stat.f_fsid.val[0]; 720 sb->st_ino = vap->va_fileid; 721 mode = vap->va_mode; 722 switch (vap->va_type) { 723 case VREG: 724 mode |= S_IFREG; 725 break; 726 case VDIR: 727 mode |= S_IFDIR; 728 break; 729 case VBLK: 730 mode |= S_IFBLK; 731 break; 732 case VCHR: 733 mode |= S_IFCHR; 734 break; 735 case VLNK: 736 mode |= S_IFLNK; 737 /* This is a cosmetic change, symlinks do not have a mode. */ 738 if (vp->v_mount->mnt_flag & MNT_NOSYMFOLLOW) 739 sb->st_mode &= ~ACCESSPERMS; /* 0000 */ 740 else 741 sb->st_mode |= ACCESSPERMS; /* 0777 */ 742 break; 743 case VSOCK: 744 mode |= S_IFSOCK; 745 break; 746 case VFIFO: 747 mode |= S_IFIFO; 748 break; 749 default: 750 return (EBADF); 751 }; 752 sb->st_mode = mode; 753 sb->st_nlink = vap->va_nlink; 754 sb->st_uid = vap->va_uid; 755 sb->st_gid = vap->va_gid; 756 sb->st_rdev = vap->va_rdev; 757 if (vap->va_size > OFF_MAX) 758 return (EOVERFLOW); 759 sb->st_size = vap->va_size; 760 sb->st_atimespec = vap->va_atime; 761 sb->st_mtimespec = vap->va_mtime; 762 sb->st_ctimespec = vap->va_ctime; 763 sb->st_birthtimespec = vap->va_birthtime; 764 765 /* 766 * According to www.opengroup.org, the meaning of st_blksize is 767 * "a filesystem-specific preferred I/O block size for this 768 * object. In some filesystem types, this may vary from file 769 * to file" 770 * Default to PAGE_SIZE after much discussion. 771 * XXX: min(PAGE_SIZE, vp->v_bufobj.bo_bsize) may be more correct. 772 */ 773 774 sb->st_blksize = PAGE_SIZE; 775 776 sb->st_flags = vap->va_flags; 777 if (priv_check(td, PRIV_VFS_GENERATION)) 778 sb->st_gen = 0; 779 else 780 sb->st_gen = vap->va_gen; 781 782 sb->st_blocks = vap->va_bytes / S_BLKSIZE; 783 return (0); 784 } 785 786 /* 787 * File table vnode ioctl routine. 788 */ 789 static int 790 vn_ioctl(fp, com, data, active_cred, td) 791 struct file *fp; 792 u_long com; 793 void *data; 794 struct ucred *active_cred; 795 struct thread *td; 796 { 797 struct vnode *vp = fp->f_vnode; 798 struct vattr vattr; 799 int vfslocked; 800 int error; 801 802 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 803 error = ENOTTY; 804 switch (vp->v_type) { 805 case VREG: 806 case VDIR: 807 if (com == FIONREAD) { 808 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 809 error = VOP_GETATTR(vp, &vattr, active_cred, td); 810 VOP_UNLOCK(vp, 0); 811 if (!error) 812 *(int *)data = vattr.va_size - fp->f_offset; 813 } 814 if (com == FIONBIO || com == FIOASYNC) /* XXX */ 815 error = 0; 816 else 817 error = VOP_IOCTL(vp, com, data, fp->f_flag, 818 active_cred, td); 819 break; 820 821 default: 822 break; 823 } 824 VFS_UNLOCK_GIANT(vfslocked); 825 return (error); 826 } 827 828 /* 829 * File table vnode poll routine. 830 */ 831 static int 832 vn_poll(fp, events, active_cred, td) 833 struct file *fp; 834 int events; 835 struct ucred *active_cred; 836 struct thread *td; 837 { 838 struct vnode *vp; 839 int vfslocked; 840 int error; 841 842 vp = fp->f_vnode; 843 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 844 #ifdef MAC 845 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 846 error = mac_vnode_check_poll(active_cred, fp->f_cred, vp); 847 VOP_UNLOCK(vp, 0); 848 if (!error) 849 #endif 850 851 error = VOP_POLL(vp, events, fp->f_cred, td); 852 VFS_UNLOCK_GIANT(vfslocked); 853 return (error); 854 } 855 856 /* 857 * Check that the vnode is still valid, and if so 858 * acquire requested lock. 859 */ 860 int 861 _vn_lock(struct vnode *vp, int flags, char *file, int line) 862 { 863 int error; 864 865 /* 866 * With no lock type requested we're just polling for validity. 867 */ 868 if ((flags & LK_TYPE_MASK) == 0) { 869 error = 0; 870 if ((flags & LK_INTERLOCK) == 0) 871 VI_LOCK(vp); 872 if (vp->v_iflag & VI_DOOMED) 873 error = ENOENT; 874 VI_UNLOCK(vp); 875 return (error); 876 } 877 do { 878 error = VOP_LOCK1(vp, flags, file, line); 879 flags &= ~LK_INTERLOCK; /* Interlock is always dropped. */ 880 KASSERT((flags & LK_RETRY) == 0 || error == 0, 881 ("LK_RETRY set with incompatible flags %d\n", flags)); 882 /* 883 * Callers specify LK_RETRY if they wish to get dead vnodes. 884 * If RETRY is not set, we return ENOENT instead. 885 */ 886 if (error == 0 && vp->v_iflag & VI_DOOMED && 887 (flags & LK_RETRY) == 0) { 888 VOP_UNLOCK(vp, 0); 889 error = ENOENT; 890 break; 891 } 892 } while (flags & LK_RETRY && error != 0); 893 return (error); 894 } 895 896 /* 897 * File table vnode close routine. 898 */ 899 static int 900 vn_closefile(fp, td) 901 struct file *fp; 902 struct thread *td; 903 { 904 struct vnode *vp; 905 struct flock lf; 906 int vfslocked; 907 int error; 908 909 vp = fp->f_vnode; 910 911 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 912 if (fp->f_type == DTYPE_VNODE && fp->f_flag & FHASLOCK) { 913 lf.l_whence = SEEK_SET; 914 lf.l_start = 0; 915 lf.l_len = 0; 916 lf.l_type = F_UNLCK; 917 (void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, F_FLOCK); 918 } 919 920 fp->f_ops = &badfileops; 921 922 error = vn_close(vp, fp->f_flag, fp->f_cred, td); 923 VFS_UNLOCK_GIANT(vfslocked); 924 return (error); 925 } 926 927 /* 928 * Preparing to start a filesystem write operation. If the operation is 929 * permitted, then we bump the count of operations in progress and 930 * proceed. If a suspend request is in progress, we wait until the 931 * suspension is over, and then proceed. 932 */ 933 int 934 vn_start_write(vp, mpp, flags) 935 struct vnode *vp; 936 struct mount **mpp; 937 int flags; 938 { 939 struct mount *mp; 940 int error; 941 942 error = 0; 943 /* 944 * If a vnode is provided, get and return the mount point that 945 * to which it will write. 946 */ 947 if (vp != NULL) { 948 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) { 949 *mpp = NULL; 950 if (error != EOPNOTSUPP) 951 return (error); 952 return (0); 953 } 954 } 955 if ((mp = *mpp) == NULL) 956 return (0); 957 MNT_ILOCK(mp); 958 if (vp == NULL) 959 MNT_REF(mp); 960 /* 961 * Check on status of suspension. 962 */ 963 while ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { 964 if (flags & V_NOWAIT) { 965 error = EWOULDBLOCK; 966 goto unlock; 967 } 968 error = msleep(&mp->mnt_flag, MNT_MTX(mp), 969 (PUSER - 1) | (flags & PCATCH), "suspfs", 0); 970 if (error) 971 goto unlock; 972 } 973 if (flags & V_XSLEEP) 974 goto unlock; 975 mp->mnt_writeopcount++; 976 unlock: 977 MNT_REL(mp); 978 MNT_IUNLOCK(mp); 979 return (error); 980 } 981 982 /* 983 * Secondary suspension. Used by operations such as vop_inactive 984 * routines that are needed by the higher level functions. These 985 * are allowed to proceed until all the higher level functions have 986 * completed (indicated by mnt_writeopcount dropping to zero). At that 987 * time, these operations are halted until the suspension is over. 988 */ 989 int 990 vn_write_suspend_wait(vp, mp, flags) 991 struct vnode *vp; 992 struct mount *mp; 993 int flags; 994 { 995 int error; 996 997 if (vp != NULL) { 998 if ((error = VOP_GETWRITEMOUNT(vp, &mp)) != 0) { 999 if (error != EOPNOTSUPP) 1000 return (error); 1001 return (0); 1002 } 1003 } 1004 /* 1005 * If we are not suspended or have not yet reached suspended 1006 * mode, then let the operation proceed. 1007 */ 1008 if (mp == NULL) 1009 return (0); 1010 MNT_ILOCK(mp); 1011 if (vp == NULL) 1012 MNT_REF(mp); 1013 if ((mp->mnt_kern_flag & MNTK_SUSPENDED) == 0) { 1014 MNT_REL(mp); 1015 MNT_IUNLOCK(mp); 1016 return (0); 1017 } 1018 if (flags & V_NOWAIT) { 1019 MNT_REL(mp); 1020 MNT_IUNLOCK(mp); 1021 return (EWOULDBLOCK); 1022 } 1023 /* 1024 * Wait for the suspension to finish. 1025 */ 1026 error = msleep(&mp->mnt_flag, MNT_MTX(mp), 1027 (PUSER - 1) | (flags & PCATCH) | PDROP, "suspfs", 0); 1028 vfs_rel(mp); 1029 return (error); 1030 } 1031 1032 /* 1033 * Secondary suspension. Used by operations such as vop_inactive 1034 * routines that are needed by the higher level functions. These 1035 * are allowed to proceed until all the higher level functions have 1036 * completed (indicated by mnt_writeopcount dropping to zero). At that 1037 * time, these operations are halted until the suspension is over. 1038 */ 1039 int 1040 vn_start_secondary_write(vp, mpp, flags) 1041 struct vnode *vp; 1042 struct mount **mpp; 1043 int flags; 1044 { 1045 struct mount *mp; 1046 int error; 1047 1048 retry: 1049 if (vp != NULL) { 1050 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) { 1051 *mpp = NULL; 1052 if (error != EOPNOTSUPP) 1053 return (error); 1054 return (0); 1055 } 1056 } 1057 /* 1058 * If we are not suspended or have not yet reached suspended 1059 * mode, then let the operation proceed. 1060 */ 1061 if ((mp = *mpp) == NULL) 1062 return (0); 1063 MNT_ILOCK(mp); 1064 if (vp == NULL) 1065 MNT_REF(mp); 1066 if ((mp->mnt_kern_flag & (MNTK_SUSPENDED | MNTK_SUSPEND2)) == 0) { 1067 mp->mnt_secondary_writes++; 1068 mp->mnt_secondary_accwrites++; 1069 MNT_REL(mp); 1070 MNT_IUNLOCK(mp); 1071 return (0); 1072 } 1073 if (flags & V_NOWAIT) { 1074 MNT_REL(mp); 1075 MNT_IUNLOCK(mp); 1076 return (EWOULDBLOCK); 1077 } 1078 /* 1079 * Wait for the suspension to finish. 1080 */ 1081 error = msleep(&mp->mnt_flag, MNT_MTX(mp), 1082 (PUSER - 1) | (flags & PCATCH) | PDROP, "suspfs", 0); 1083 vfs_rel(mp); 1084 if (error == 0) 1085 goto retry; 1086 return (error); 1087 } 1088 1089 /* 1090 * Filesystem write operation has completed. If we are suspending and this 1091 * operation is the last one, notify the suspender that the suspension is 1092 * now in effect. 1093 */ 1094 void 1095 vn_finished_write(mp) 1096 struct mount *mp; 1097 { 1098 if (mp == NULL) 1099 return; 1100 MNT_ILOCK(mp); 1101 mp->mnt_writeopcount--; 1102 if (mp->mnt_writeopcount < 0) 1103 panic("vn_finished_write: neg cnt"); 1104 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && 1105 mp->mnt_writeopcount <= 0) 1106 wakeup(&mp->mnt_writeopcount); 1107 MNT_IUNLOCK(mp); 1108 } 1109 1110 1111 /* 1112 * Filesystem secondary write operation has completed. If we are 1113 * suspending and this operation is the last one, notify the suspender 1114 * that the suspension is now in effect. 1115 */ 1116 void 1117 vn_finished_secondary_write(mp) 1118 struct mount *mp; 1119 { 1120 if (mp == NULL) 1121 return; 1122 MNT_ILOCK(mp); 1123 mp->mnt_secondary_writes--; 1124 if (mp->mnt_secondary_writes < 0) 1125 panic("vn_finished_secondary_write: neg cnt"); 1126 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && 1127 mp->mnt_secondary_writes <= 0) 1128 wakeup(&mp->mnt_secondary_writes); 1129 MNT_IUNLOCK(mp); 1130 } 1131 1132 1133 1134 /* 1135 * Request a filesystem to suspend write operations. 1136 */ 1137 int 1138 vfs_write_suspend(mp) 1139 struct mount *mp; 1140 { 1141 struct thread *td = curthread; 1142 int error; 1143 1144 MNT_ILOCK(mp); 1145 if (mp->mnt_kern_flag & MNTK_SUSPEND) { 1146 MNT_IUNLOCK(mp); 1147 return (0); 1148 } 1149 mp->mnt_kern_flag |= MNTK_SUSPEND; 1150 if (mp->mnt_writeopcount > 0) 1151 (void) msleep(&mp->mnt_writeopcount, 1152 MNT_MTX(mp), (PUSER - 1)|PDROP, "suspwt", 0); 1153 else 1154 MNT_IUNLOCK(mp); 1155 if ((error = VFS_SYNC(mp, MNT_SUSPEND, td)) != 0) 1156 vfs_write_resume(mp); 1157 return (error); 1158 } 1159 1160 /* 1161 * Request a filesystem to resume write operations. 1162 */ 1163 void 1164 vfs_write_resume(mp) 1165 struct mount *mp; 1166 { 1167 1168 MNT_ILOCK(mp); 1169 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { 1170 mp->mnt_kern_flag &= ~(MNTK_SUSPEND | MNTK_SUSPEND2 | 1171 MNTK_SUSPENDED); 1172 wakeup(&mp->mnt_writeopcount); 1173 wakeup(&mp->mnt_flag); 1174 } 1175 MNT_IUNLOCK(mp); 1176 } 1177 1178 /* 1179 * Implement kqueues for files by translating it to vnode operation. 1180 */ 1181 static int 1182 vn_kqfilter(struct file *fp, struct knote *kn) 1183 { 1184 int vfslocked; 1185 int error; 1186 1187 vfslocked = VFS_LOCK_GIANT(fp->f_vnode->v_mount); 1188 error = VOP_KQFILTER(fp->f_vnode, kn); 1189 VFS_UNLOCK_GIANT(vfslocked); 1190 1191 return error; 1192 } 1193 1194 /* 1195 * Simplified in-kernel wrapper calls for extended attribute access. 1196 * Both calls pass in a NULL credential, authorizing as "kernel" access. 1197 * Set IO_NODELOCKED in ioflg if the vnode is already locked. 1198 */ 1199 int 1200 vn_extattr_get(struct vnode *vp, int ioflg, int attrnamespace, 1201 const char *attrname, int *buflen, char *buf, struct thread *td) 1202 { 1203 struct uio auio; 1204 struct iovec iov; 1205 int error; 1206 1207 iov.iov_len = *buflen; 1208 iov.iov_base = buf; 1209 1210 auio.uio_iov = &iov; 1211 auio.uio_iovcnt = 1; 1212 auio.uio_rw = UIO_READ; 1213 auio.uio_segflg = UIO_SYSSPACE; 1214 auio.uio_td = td; 1215 auio.uio_offset = 0; 1216 auio.uio_resid = *buflen; 1217 1218 if ((ioflg & IO_NODELOCKED) == 0) 1219 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1220 1221 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 1222 1223 /* authorize attribute retrieval as kernel */ 1224 error = VOP_GETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, NULL, 1225 td); 1226 1227 if ((ioflg & IO_NODELOCKED) == 0) 1228 VOP_UNLOCK(vp, 0); 1229 1230 if (error == 0) { 1231 *buflen = *buflen - auio.uio_resid; 1232 } 1233 1234 return (error); 1235 } 1236 1237 /* 1238 * XXX failure mode if partially written? 1239 */ 1240 int 1241 vn_extattr_set(struct vnode *vp, int ioflg, int attrnamespace, 1242 const char *attrname, int buflen, char *buf, struct thread *td) 1243 { 1244 struct uio auio; 1245 struct iovec iov; 1246 struct mount *mp; 1247 int error; 1248 1249 iov.iov_len = buflen; 1250 iov.iov_base = buf; 1251 1252 auio.uio_iov = &iov; 1253 auio.uio_iovcnt = 1; 1254 auio.uio_rw = UIO_WRITE; 1255 auio.uio_segflg = UIO_SYSSPACE; 1256 auio.uio_td = td; 1257 auio.uio_offset = 0; 1258 auio.uio_resid = buflen; 1259 1260 if ((ioflg & IO_NODELOCKED) == 0) { 1261 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) 1262 return (error); 1263 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1264 } 1265 1266 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 1267 1268 /* authorize attribute setting as kernel */ 1269 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, td); 1270 1271 if ((ioflg & IO_NODELOCKED) == 0) { 1272 vn_finished_write(mp); 1273 VOP_UNLOCK(vp, 0); 1274 } 1275 1276 return (error); 1277 } 1278 1279 int 1280 vn_extattr_rm(struct vnode *vp, int ioflg, int attrnamespace, 1281 const char *attrname, struct thread *td) 1282 { 1283 struct mount *mp; 1284 int error; 1285 1286 if ((ioflg & IO_NODELOCKED) == 0) { 1287 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) 1288 return (error); 1289 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1290 } 1291 1292 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 1293 1294 /* authorize attribute removal as kernel */ 1295 error = VOP_DELETEEXTATTR(vp, attrnamespace, attrname, NULL, td); 1296 if (error == EOPNOTSUPP) 1297 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, NULL, 1298 NULL, td); 1299 1300 if ((ioflg & IO_NODELOCKED) == 0) { 1301 vn_finished_write(mp); 1302 VOP_UNLOCK(vp, 0); 1303 } 1304 1305 return (error); 1306 } 1307