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 * 3. 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 * $FreeBSD: src/sys/kern/vfs_vnops.c,v 1.87.2.13 2002/12/29 18:19:53 dillon Exp $ 36 */ 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/uio.h> 41 #include <sys/fcntl.h> 42 #include <sys/file.h> 43 #include <sys/stat.h> 44 #include <sys/proc.h> 45 #include <sys/caps.h> 46 #include <sys/mount.h> 47 #include <sys/nlookup.h> 48 #include <sys/vnode.h> 49 #include <sys/buf.h> 50 #include <sys/filio.h> 51 #include <sys/ttycom.h> 52 #include <sys/conf.h> 53 #include <sys/sysctl.h> 54 #include <sys/syslog.h> 55 #include <sys/spinlock.h> 56 #include <sys/spinlock2.h> 57 58 #include <sys/mplock2.h> 59 60 static int vn_closefile (struct file *fp); 61 static int vn_ioctl (struct file *fp, u_long com, caddr_t data, 62 struct ucred *cred, struct sysmsg *msg); 63 static int vn_read (struct file *fp, struct uio *uio, 64 struct ucred *cred, int flags); 65 static int vn_kqfilter (struct file *fp, struct knote *kn); 66 static int vn_statfile (struct file *fp, struct stat *sb, struct ucred *cred); 67 static int vn_write (struct file *fp, struct uio *uio, 68 struct ucred *cred, int flags); 69 static int vn_seek (struct file *fp, off_t offset, int whence, off_t *res); 70 71 struct fileops vnode_fileops = { 72 .fo_read = vn_read, 73 .fo_write = vn_write, 74 .fo_ioctl = vn_ioctl, 75 .fo_kqfilter = vn_kqfilter, 76 .fo_stat = vn_statfile, 77 .fo_close = vn_closefile, 78 .fo_shutdown = nofo_shutdown, 79 .fo_seek = vn_seek 80 }; 81 82 /* 83 * Common code for vnode open operations. Check permissions, and call 84 * the VOP_NOPEN or VOP_NCREATE routine. 85 * 86 * The caller is responsible for setting up nd with nlookup_init() and 87 * for cleaning it up with nlookup_done(), whether we return an error 88 * or not. 89 * 90 * On success nd->nl_open_vp will hold a referenced and, if requested, 91 * locked vnode. A locked vnode is requested via NLC_LOCKVP. If fp 92 * is non-NULL the vnode will be installed in the file pointer. 93 * 94 * NOTE: If the caller wishes the namecache entry to be operated with 95 * a shared lock it must use NLC_SHAREDLOCK. If NLC_LOCKVP is set 96 * then the vnode lock will also be shared. 97 * 98 * NOTE: The vnode is referenced just once on return whether or not it 99 * is also installed in the file pointer. 100 */ 101 int 102 vn_open(struct nlookupdata *nd, struct file **fpp, int fmode, int cmode) 103 { 104 struct file *fp = fpp ? *fpp : NULL; 105 struct vnode *vp; 106 struct ucred *cred = nd->nl_cred; 107 struct vattr vat; 108 struct vattr *vap = &vat; 109 int error; 110 int vpexcl; 111 u_int flags; 112 uint64_t osize; 113 struct mount *mp; 114 115 /* 116 * Certain combinations are illegal 117 */ 118 if ((fmode & (FWRITE | O_TRUNC)) == O_TRUNC) 119 return(EACCES); 120 121 /* 122 * Lookup the path and create or obtain the vnode. After a 123 * successful lookup a locked nd->nl_nch will be returned. 124 * 125 * The result of this section should be a locked vnode. 126 * 127 * XXX with only a little work we should be able to avoid locking 128 * the vnode if FWRITE, O_CREAT, and O_TRUNC are *not* set. 129 */ 130 nd->nl_flags |= NLC_OPEN; 131 if (fmode & O_APPEND) 132 nd->nl_flags |= NLC_APPEND; 133 if (fmode & O_TRUNC) 134 nd->nl_flags |= NLC_TRUNCATE; 135 if (fmode & FREAD) 136 nd->nl_flags |= NLC_READ; 137 if (fmode & FWRITE) 138 nd->nl_flags |= NLC_WRITE; 139 if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0) 140 nd->nl_flags |= NLC_FOLLOW; 141 142 if (fmode & O_CREAT) { 143 /* 144 * CONDITIONAL CREATE FILE CASE 145 * 146 * Setting NLC_CREATE causes a negative hit to store 147 * the negative hit ncp and not return an error. Then 148 * nc_error or nc_vp may be checked to see if the ncp 149 * represents a negative hit. NLC_CREATE also requires 150 * write permission on the governing directory or EPERM 151 * is returned. 152 * 153 * If the file exists but is missing write permission, 154 * nlookup() returns EACCES. This has to be handled specially 155 * when combined with O_EXCL. 156 */ 157 nd->nl_flags |= NLC_CREATE; 158 nd->nl_flags |= NLC_REFDVP; 159 bwillinode(1); 160 error = nlookup(nd); 161 if (error == EACCES && nd->nl_nch.ncp->nc_vp != NULL && 162 (fmode & O_EXCL) && !nd->nl_dir_error) 163 { 164 error = EEXIST; 165 } 166 167 /* 168 * If no error and nd->nl_dvp is NULL, the nlookup represents 169 * a mount-point or cross-mount situation. e.g. 170 * open("/var/cache", O_CREAT), where /var/cache is a 171 * mount point or a null-mount point. 172 */ 173 if (error == 0 && nd->nl_dvp == NULL) 174 error = EINVAL; 175 } else { 176 /* 177 * NORMAL OPEN FILE CASE 178 */ 179 error = nlookup(nd); 180 } 181 182 if (error) 183 return (error); 184 185 /* 186 * split case to allow us to re-resolve and retry the ncp in case 187 * we get ESTALE. 188 * 189 * (error is 0 on entry / retry) 190 */ 191 again: 192 /* 193 * Checks for (likely) filesystem-modifying cases and allows 194 * the filesystem to stall the front-end. 195 */ 196 if ((fmode & (FWRITE | O_TRUNC)) || 197 ((fmode & O_CREAT) && nd->nl_nch.ncp->nc_vp == NULL)) { 198 error = ncp_writechk(&nd->nl_nch); 199 if (error) 200 return error; 201 } 202 203 vpexcl = 1; 204 if (fmode & O_CREAT) { 205 if (nd->nl_nch.ncp->nc_vp == NULL) { 206 VATTR_NULL(vap); 207 vap->va_type = VREG; 208 vap->va_mode = cmode; 209 vap->va_fuseflags = fmode; /* FUSE */ 210 if (fmode & O_EXCL) 211 vap->va_vaflags |= VA_EXCLUSIVE; 212 error = VOP_NCREATE(&nd->nl_nch, nd->nl_dvp, &vp, 213 nd->nl_cred, vap); 214 if (error) 215 return (error); 216 fmode &= ~O_TRUNC; 217 /* locked vnode is returned */ 218 } else { 219 if (fmode & O_EXCL) { 220 error = EEXIST; 221 } else { 222 error = cache_vget(&nd->nl_nch, cred, 223 LK_EXCLUSIVE, &vp); 224 } 225 if (error) 226 return (error); 227 fmode &= ~O_CREAT; 228 } 229 } else { 230 /* 231 * In most other cases a shared lock on the vnode is 232 * sufficient. However, the O_RDWR case needs an 233 * exclusive lock if the vnode is executable. The 234 * NLC_EXCLLOCK_IFEXEC and NCF_NOTX flags help resolve 235 * this. 236 * 237 * NOTE: If NCF_NOTX is not set, we do not know the 238 * the state of the 'x' bits and have to get 239 * an exclusive lock for the EXCLLOCK_IFEXEC case. 240 */ 241 if ((nd->nl_flags & NLC_SHAREDLOCK) && 242 ((nd->nl_flags & NLC_EXCLLOCK_IFEXEC) == 0 || 243 nd->nl_nch.ncp->nc_flag & NCF_NOTX)) { 244 error = cache_vget(&nd->nl_nch, cred, LK_SHARED, &vp); 245 vpexcl = 0; 246 } else { 247 error = cache_vget(&nd->nl_nch, cred, 248 LK_EXCLUSIVE, &vp); 249 } 250 if (error) 251 return (error); 252 } 253 254 /* 255 * We have a locked vnode and ncp now. Note that the ncp will 256 * be cleaned up by the caller if nd->nl_nch is left intact. 257 */ 258 if (vp->v_type == VLNK) { 259 error = EMLINK; 260 goto bad; 261 } 262 if (vp->v_type == VSOCK) { 263 error = EOPNOTSUPP; 264 goto bad; 265 } 266 if (vp->v_type != VDIR && (fmode & O_DIRECTORY)) { 267 error = ENOTDIR; 268 goto bad; 269 } 270 if ((fmode & O_CREAT) == 0) { 271 if (fmode & (FWRITE | O_TRUNC)) { 272 if (vp->v_type == VDIR) { 273 error = EISDIR; 274 goto bad; 275 } 276 277 /* 278 * Additional checks on vnode (does not substitute 279 * for ncp_writechk()). 280 */ 281 error = vn_writechk(vp); 282 if (error) { 283 /* 284 * Special stale handling, re-resolve the 285 * vnode. 286 */ 287 if (error == ESTALE) { 288 u_int dummy_gen = 0; 289 290 vput(vp); 291 vp = NULL; 292 if (vpexcl == 0) { 293 cache_unlock(&nd->nl_nch); 294 cache_lock(&nd->nl_nch); 295 } 296 cache_setunresolved(&nd->nl_nch); 297 error = cache_resolve(&nd->nl_nch, 298 &dummy_gen, 299 cred); 300 if (error == 0) 301 goto again; 302 } 303 goto bad; 304 } 305 } 306 } 307 if (fmode & O_TRUNC) { 308 vn_unlock(vp); /* XXX */ 309 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); /* XXX */ 310 osize = vp->v_filesize; 311 VATTR_NULL(vap); 312 vap->va_size = 0; 313 error = VOP_SETATTR_FP(vp, vap, cred, fp); 314 if (error) 315 goto bad; 316 error = VOP_GETATTR(vp, vap); 317 if (error) 318 goto bad; 319 mp = vq_vptomp(vp); 320 VFS_ACCOUNT(mp, vap->va_uid, vap->va_gid, -osize); 321 } 322 323 /* 324 * Set or clear VNSWAPCACHE on the vp based on nd->nl_nch.ncp->nc_flag. 325 * These particular bits a tracked all the way from the root. 326 * 327 * NOTE: Might not work properly on NFS servers due to the 328 * disconnected namecache. 329 */ 330 flags = nd->nl_nch.ncp->nc_flag; 331 if ((flags & (NCF_UF_CACHE | NCF_UF_PCACHE)) && 332 (flags & (NCF_SF_NOCACHE | NCF_SF_PNOCACHE)) == 0) { 333 vsetflags(vp, VSWAPCACHE); 334 } else { 335 vclrflags(vp, VSWAPCACHE); 336 } 337 338 /* 339 * Setup the fp so VOP_OPEN can override it. No descriptor has been 340 * associated with the fp yet so we own it clean. 341 * 342 * f_nchandle inherits nl_nch. This used to be necessary only for 343 * directories but now we do it unconditionally so f*() ops 344 * such as fchmod() can access the actual namespace that was 345 * used to open the file. 346 */ 347 if (fp) { 348 if (nd->nl_flags & NLC_APPENDONLY) 349 fmode |= FAPPENDONLY; 350 fp->f_nchandle = nd->nl_nch; 351 cache_zero(&nd->nl_nch); 352 cache_unlock(&fp->f_nchandle); 353 } 354 355 /* 356 * Get rid of nl_nch. vn_open does not return it (it returns the 357 * vnode or the file pointer). 358 * 359 * NOTE: We can't leave nl_nch locked through the VOP_OPEN anyway 360 * since the VOP_OPEN may block, e.g. on /dev/ttyd0 361 * 362 * NOTE: The VOP_OPEN() can replace the *fpp we supply with its own 363 * (it will fdrop/fhold), and can also set the *fpp up however 364 * it wants, not necessarily using DTYPE_VNODE. 365 */ 366 if (nd->nl_nch.ncp) 367 cache_put(&nd->nl_nch); 368 369 error = VOP_OPEN(vp, fmode, cred, fpp); 370 fp = fpp ? *fpp : NULL; 371 372 if (error) { 373 /* 374 * setting f_ops to &badfileops will prevent the descriptor 375 * code from trying to close and release the vnode, since 376 * the open failed we do not want to call close. 377 */ 378 if (fp) { 379 fp->f_data = NULL; 380 fp->f_ops = &badfileops; 381 } 382 goto bad; 383 } 384 385 #if 0 386 /* 387 * Assert that VREG files have been setup for vmio. 388 */ 389 KASSERT(vp->v_type != VREG || vp->v_object != NULL, 390 ("vn_open: regular file was not VMIO enabled!")); 391 #endif 392 393 /* 394 * Return the vnode. XXX needs some cleaning up. The vnode is 395 * only returned in the fp == NULL case. 396 * 397 * NOTE: vnode stored in fp may be different 398 */ 399 if (fp == NULL) { 400 nd->nl_open_vp = vp; 401 nd->nl_vp_fmode = fmode; 402 if ((nd->nl_flags & NLC_LOCKVP) == 0) 403 vn_unlock(vp); 404 } else { 405 vput(vp); 406 } 407 return (0); 408 bad: 409 if (vp) 410 vput(vp); 411 return (error); 412 } 413 414 int 415 vn_opendisk(const char *devname, int fmode, struct vnode **vpp) 416 { 417 struct vnode *vp; 418 int error; 419 420 if (strncmp(devname, "/dev/", 5) == 0) 421 devname += 5; 422 if ((vp = getsynthvnode(devname)) == NULL) { 423 error = ENODEV; 424 } else { 425 error = VOP_OPEN(vp, fmode, proc0.p_ucred, NULL); 426 vn_unlock(vp); 427 if (error) { 428 vrele(vp); 429 vp = NULL; 430 } 431 } 432 *vpp = vp; 433 return (error); 434 } 435 436 /* 437 * Checks for special conditions on the vnode which might prevent writing 438 * after the vnode has (likely) been locked. The vnode might or might not 439 * be locked as of this call, but will be at least referenced. 440 * 441 * Also re-checks the mount RDONLY flag that ncp_writechk() checked prior 442 * to the vnode being locked. 443 */ 444 int 445 vn_writechk(struct vnode *vp) 446 { 447 /* 448 * If there's shared text associated with 449 * the vnode, try to free it up once. If 450 * we fail, we can't allow writing. 451 */ 452 if (vp->v_flag & VTEXT) 453 return (ETXTBSY); 454 if (vp->v_mount && (vp->v_mount->mnt_flag & MNT_RDONLY)) 455 return (EROFS); 456 return 0; 457 } 458 459 /* 460 * Check whether the underlying mount is read-only. The mount point 461 * referenced by the namecache may be different from the mount point 462 * used by the underlying vnode in the case of NULLFS, so a separate 463 * check is needed. 464 * 465 * Must be called PRIOR to any vnodes being locked. 466 */ 467 int 468 ncp_writechk(struct nchandle *nch) 469 { 470 struct mount *mp; 471 472 if ((mp = nch->mount) != NULL) { 473 if (mp->mnt_flag & MNT_RDONLY) 474 return (EROFS); 475 if (mp->mnt_op->vfs_modifying != vfs_stdmodifying) 476 VFS_MODIFYING(mp); 477 } 478 return(0); 479 } 480 481 /* 482 * Vnode close call 483 * 484 * MPSAFE 485 */ 486 int 487 vn_close(struct vnode *vp, int flags, struct file *fp) 488 { 489 int error; 490 491 error = vn_lock(vp, LK_SHARED | LK_RETRY | LK_FAILRECLAIM); 492 if (error == 0) { 493 error = VOP_CLOSE(vp, flags, fp); 494 vn_unlock(vp); 495 } 496 vrele(vp); 497 return (error); 498 } 499 500 /* 501 * Sequential heuristic. 502 * 503 * MPSAFE (f_seqcount and f_nextoff are allowed to race) 504 */ 505 static __inline 506 int 507 sequential_heuristic(struct uio *uio, struct file *fp) 508 { 509 /* 510 * Sequential heuristic - detect sequential operation 511 * 512 * NOTE: SMP: We allow f_seqcount updates to race. 513 */ 514 if ((uio->uio_offset == 0 && fp->f_seqcount > 0) || 515 uio->uio_offset == fp->f_nextoff) { 516 int tmpseq = fp->f_seqcount; 517 518 tmpseq += howmany(uio->uio_resid, MAXBSIZE); 519 if (tmpseq > IO_SEQMAX) 520 tmpseq = IO_SEQMAX; 521 fp->f_seqcount = tmpseq; 522 return(fp->f_seqcount << IO_SEQSHIFT); 523 } 524 525 /* 526 * Not sequential, quick draw-down of seqcount 527 * 528 * NOTE: SMP: We allow f_seqcount updates to race. 529 */ 530 if (fp->f_seqcount > 1) 531 fp->f_seqcount = 1; 532 else 533 fp->f_seqcount = 0; 534 return(0); 535 } 536 537 /* 538 * get - lock and return the f_offset field. 539 * set - set and unlock the f_offset field. 540 * 541 * These routines serve the dual purpose of serializing access to the 542 * f_offset field (at least on x86) and guaranteeing operational integrity 543 * when multiple read()ers and write()ers are present on the same fp. 544 * 545 * MPSAFE 546 */ 547 static __inline off_t 548 vn_get_fpf_offset(struct file *fp) 549 { 550 u_int flags; 551 u_int nflags; 552 553 /* 554 * Shortcut critical path. 555 */ 556 flags = fp->f_flag & ~FOFFSETLOCK; 557 if (atomic_cmpset_int(&fp->f_flag, flags, flags | FOFFSETLOCK)) 558 return(fp->f_offset); 559 560 /* 561 * The hard way 562 */ 563 for (;;) { 564 flags = fp->f_flag; 565 if (flags & FOFFSETLOCK) { 566 nflags = flags | FOFFSETWAKE; 567 tsleep_interlock(&fp->f_flag, 0); 568 if (atomic_cmpset_int(&fp->f_flag, flags, nflags)) 569 tsleep(&fp->f_flag, PINTERLOCKED, "fpoff", 0); 570 } else { 571 nflags = flags | FOFFSETLOCK; 572 if (atomic_cmpset_int(&fp->f_flag, flags, nflags)) 573 break; 574 } 575 } 576 return(fp->f_offset); 577 } 578 579 /* 580 * MPSAFE 581 */ 582 static __inline void 583 vn_set_fpf_offset(struct file *fp, off_t offset) 584 { 585 u_int flags; 586 u_int nflags; 587 588 /* 589 * We hold the lock so we can set the offset without interference. 590 */ 591 fp->f_offset = offset; 592 593 /* 594 * Normal release is already a reasonably critical path. 595 */ 596 for (;;) { 597 flags = fp->f_flag; 598 nflags = flags & ~(FOFFSETLOCK | FOFFSETWAKE); 599 if (atomic_cmpset_int(&fp->f_flag, flags, nflags)) { 600 if (flags & FOFFSETWAKE) 601 wakeup(&fp->f_flag); 602 break; 603 } 604 } 605 } 606 607 /* 608 * MPSAFE 609 */ 610 static __inline off_t 611 vn_poll_fpf_offset(struct file *fp) 612 { 613 #if defined(__x86_64__) 614 return(fp->f_offset); 615 #else 616 off_t off = vn_get_fpf_offset(fp); 617 vn_set_fpf_offset(fp, off); 618 return(off); 619 #endif 620 } 621 622 /* 623 * Package up an I/O request on a vnode into a uio and do it. 624 * 625 * MPSAFE 626 */ 627 int 628 vn_rdwr(enum uio_rw rw, struct vnode *vp, caddr_t base, int len, 629 off_t offset, enum uio_seg segflg, int ioflg, 630 struct ucred *cred, int *aresid) 631 { 632 struct uio auio; 633 struct iovec aiov; 634 int error; 635 636 if ((ioflg & IO_NODELOCKED) == 0) 637 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 638 auio.uio_iov = &aiov; 639 auio.uio_iovcnt = 1; 640 aiov.iov_base = base; 641 aiov.iov_len = len; 642 auio.uio_resid = len; 643 auio.uio_offset = offset; 644 auio.uio_segflg = segflg; 645 auio.uio_rw = rw; 646 auio.uio_td = curthread; 647 if (rw == UIO_READ) { 648 error = VOP_READ(vp, &auio, ioflg, cred); 649 } else { 650 error = VOP_WRITE(vp, &auio, ioflg, cred); 651 } 652 if (aresid) 653 *aresid = auio.uio_resid; 654 else 655 if (auio.uio_resid && error == 0) 656 error = EIO; 657 if ((ioflg & IO_NODELOCKED) == 0) 658 vn_unlock(vp); 659 return (error); 660 } 661 662 /* 663 * Package up an I/O request on a vnode into a uio and do it. The I/O 664 * request is split up into smaller chunks and we try to avoid saturating 665 * the buffer cache while potentially holding a vnode locked, so we 666 * check bwillwrite() before calling vn_rdwr(). We also call lwkt_user_yield() 667 * to give other processes a chance to lock the vnode (either other processes 668 * core'ing the same binary, or unrelated processes scanning the directory). 669 * 670 * MPSAFE 671 */ 672 int 673 vn_rdwr_inchunks(enum uio_rw rw, struct vnode *vp, caddr_t base, int len, 674 off_t offset, enum uio_seg segflg, int ioflg, 675 struct ucred *cred, int *aresid) 676 { 677 int error = 0; 678 679 do { 680 int chunk; 681 682 /* 683 * Force `offset' to a multiple of MAXBSIZE except possibly 684 * for the first chunk, so that filesystems only need to 685 * write full blocks except possibly for the first and last 686 * chunks. 687 */ 688 chunk = MAXBSIZE - (uoff_t)offset % MAXBSIZE; 689 690 if (chunk > len) 691 chunk = len; 692 if (vp->v_type == VREG && (ioflg & IO_RECURSE) == 0) { 693 switch(rw) { 694 case UIO_READ: 695 bwillread(chunk); 696 break; 697 case UIO_WRITE: 698 bwillwrite(chunk); 699 break; 700 } 701 } 702 error = vn_rdwr(rw, vp, base, chunk, offset, segflg, 703 ioflg, cred, aresid); 704 len -= chunk; /* aresid calc already includes length */ 705 if (error) 706 break; 707 offset += chunk; 708 base += chunk; 709 lwkt_user_yield(); 710 } while (len); 711 if (aresid) 712 *aresid += len; 713 return (error); 714 } 715 716 /* 717 * File pointers can no longer get ripped up by revoke so 718 * we don't need to lock access to the vp. 719 * 720 * f_offset updates are not guaranteed against multiple readers 721 */ 722 static int 723 vn_read(struct file *fp, struct uio *uio, struct ucred *cred, int flags) 724 { 725 struct vnode *vp; 726 int error, ioflag; 727 728 KASSERT(uio->uio_td == curthread, 729 ("uio_td %p is not td %p", uio->uio_td, curthread)); 730 vp = (struct vnode *)fp->f_data; 731 732 ioflag = 0; 733 if (flags & O_FBLOCKING) { 734 /* ioflag &= ~IO_NDELAY; */ 735 } else if (flags & O_FNONBLOCKING) { 736 ioflag |= IO_NDELAY; 737 } else if (fp->f_flag & FNONBLOCK) { 738 ioflag |= IO_NDELAY; 739 } 740 if (fp->f_flag & O_DIRECT) { 741 ioflag |= IO_DIRECT; 742 } 743 if ((flags & O_FOFFSET) == 0 && (vp->v_flag & VNOTSEEKABLE) == 0) 744 uio->uio_offset = vn_get_fpf_offset(fp); 745 vn_lock(vp, LK_SHARED | LK_RETRY); 746 ioflag |= sequential_heuristic(uio, fp); 747 748 error = VOP_READ_FP(vp, uio, ioflag, cred, fp); 749 fp->f_nextoff = uio->uio_offset; 750 vn_unlock(vp); 751 if ((flags & O_FOFFSET) == 0 && (vp->v_flag & VNOTSEEKABLE) == 0) 752 vn_set_fpf_offset(fp, uio->uio_offset); 753 return (error); 754 } 755 756 /* 757 * MPSAFE 758 */ 759 static int 760 vn_write(struct file *fp, struct uio *uio, struct ucred *cred, int flags) 761 { 762 struct vnode *vp; 763 int error, ioflag; 764 765 KASSERT(uio->uio_td == curthread, 766 ("uio_td %p is not p %p", uio->uio_td, curthread)); 767 vp = (struct vnode *)fp->f_data; 768 769 ioflag = IO_UNIT; 770 if (vp->v_type == VREG && 771 ((fp->f_flag & O_APPEND) || (flags & O_FAPPEND))) { 772 ioflag |= IO_APPEND; 773 } 774 775 if (flags & O_FBLOCKING) { 776 /* ioflag &= ~IO_NDELAY; */ 777 } else if (flags & O_FNONBLOCKING) { 778 ioflag |= IO_NDELAY; 779 } else if (fp->f_flag & FNONBLOCK) { 780 ioflag |= IO_NDELAY; 781 } 782 if (fp->f_flag & O_DIRECT) { 783 ioflag |= IO_DIRECT; 784 } 785 if (flags & O_FASYNCWRITE) { 786 /* ioflag &= ~IO_SYNC; */ 787 } else if (flags & O_FSYNCWRITE) { 788 ioflag |= IO_SYNC; 789 } else if (fp->f_flag & O_FSYNC) { 790 ioflag |= IO_SYNC; 791 } 792 793 if (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS)) 794 ioflag |= IO_SYNC; 795 if ((flags & O_FOFFSET) == 0) 796 uio->uio_offset = vn_get_fpf_offset(fp); 797 if (vp->v_mount) 798 VFS_MODIFYING(vp->v_mount); 799 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 800 ioflag |= sequential_heuristic(uio, fp); 801 error = VOP_WRITE_FP(vp, uio, ioflag, cred, fp); 802 fp->f_nextoff = uio->uio_offset; 803 vn_unlock(vp); 804 if ((flags & O_FOFFSET) == 0) 805 vn_set_fpf_offset(fp, uio->uio_offset); 806 return (error); 807 } 808 809 /* 810 * MPSAFE 811 */ 812 static int 813 vn_statfile(struct file *fp, struct stat *sb, struct ucred *cred) 814 { 815 struct vnode *vp; 816 int error; 817 818 vp = (struct vnode *)fp->f_data; 819 error = vn_stat(vp, sb, cred); 820 return (error); 821 } 822 823 /* 824 * MPSAFE 825 */ 826 int 827 vn_stat(struct vnode *vp, struct stat *sb, struct ucred *cred) 828 { 829 struct vattr vattr; 830 struct vattr *vap; 831 int error; 832 u_short mode; 833 cdev_t dev; 834 835 /* 836 * vp already has a ref and is validated, can call unlocked. 837 */ 838 vap = &vattr; 839 error = VOP_GETATTR(vp, vap); 840 if (error) 841 return (error); 842 843 /* 844 * Zero the spare stat fields 845 */ 846 sb->st_lspare = 0; 847 sb->st_qspare2 = 0; 848 849 /* 850 * Copy from vattr table 851 */ 852 if (vap->va_fsid != VNOVAL) 853 sb->st_dev = vap->va_fsid; 854 else 855 sb->st_dev = vp->v_mount->mnt_stat.f_fsid.val[0]; 856 sb->st_ino = vap->va_fileid; 857 mode = vap->va_mode; 858 switch (vap->va_type) { 859 case VREG: 860 mode |= S_IFREG; 861 break; 862 case VDATABASE: 863 mode |= S_IFDB; 864 break; 865 case VDIR: 866 mode |= S_IFDIR; 867 break; 868 case VBLK: 869 mode |= S_IFBLK; 870 break; 871 case VCHR: 872 mode |= S_IFCHR; 873 break; 874 case VLNK: 875 mode |= S_IFLNK; 876 /* This is a cosmetic change, symlinks do not have a mode. */ 877 if (vp->v_mount->mnt_flag & MNT_NOSYMFOLLOW) 878 sb->st_mode &= ~ACCESSPERMS; /* 0000 */ 879 else 880 sb->st_mode |= ACCESSPERMS; /* 0777 */ 881 break; 882 case VSOCK: 883 mode |= S_IFSOCK; 884 break; 885 case VFIFO: 886 mode |= S_IFIFO; 887 break; 888 default: 889 return (EBADF); 890 } 891 sb->st_mode = mode; 892 if (vap->va_nlink > (nlink_t)-1) 893 sb->st_nlink = (nlink_t)-1; 894 else 895 sb->st_nlink = vap->va_nlink; 896 sb->st_uid = vap->va_uid; 897 sb->st_gid = vap->va_gid; 898 sb->st_rdev = devid_from_dev(vp->v_rdev); 899 sb->st_size = vap->va_size; 900 sb->st_atimespec = vap->va_atime; 901 sb->st_mtimespec = vap->va_mtime; 902 sb->st_ctimespec = vap->va_ctime; 903 904 /* 905 * A VCHR and VBLK device may track the last access and last modified 906 * time independantly of the filesystem. This is particularly true 907 * because device read and write calls may bypass the filesystem. 908 */ 909 if (vp->v_type == VCHR || vp->v_type == VBLK) { 910 dev = vp->v_rdev; 911 if (dev != NULL) { 912 if (dev->si_lastread) { 913 sb->st_atimespec.tv_sec = time_second + 914 (dev->si_lastread - 915 time_uptime); 916 sb->st_atimespec.tv_nsec = 0; 917 } 918 if (dev->si_lastwrite) { 919 sb->st_mtimespec.tv_sec = time_second + 920 (dev->si_lastwrite - 921 time_uptime); 922 sb->st_mtimespec.tv_nsec = 0; 923 } 924 } 925 } 926 927 /* 928 * According to www.opengroup.org, the meaning of st_blksize is 929 * "a filesystem-specific preferred I/O block size for this 930 * object. In some filesystem types, this may vary from file 931 * to file" 932 * Default to PAGE_SIZE after much discussion. 933 */ 934 935 if (vap->va_type == VREG) { 936 sb->st_blksize = vap->va_blocksize; 937 } else if (vn_isdisk(vp, NULL)) { 938 /* 939 * XXX this is broken. If the device is not yet open (aka 940 * stat() call, aka v_rdev == NULL), how are we supposed 941 * to get a valid block size out of it? 942 */ 943 dev = vp->v_rdev; 944 945 sb->st_blksize = dev->si_bsize_best; 946 if (sb->st_blksize < dev->si_bsize_phys) 947 sb->st_blksize = dev->si_bsize_phys; 948 if (sb->st_blksize < BLKDEV_IOSIZE) 949 sb->st_blksize = BLKDEV_IOSIZE; 950 } else { 951 sb->st_blksize = PAGE_SIZE; 952 } 953 954 sb->st_flags = vap->va_flags; 955 956 error = caps_priv_check(cred, SYSCAP_NOVFS_GENERATION); 957 if (error) 958 sb->st_gen = 0; 959 else 960 sb->st_gen = (u_int32_t)vap->va_gen; 961 962 sb->st_blocks = vap->va_bytes / S_BLKSIZE; 963 964 /* 965 * This is for ABI compatibility <= 5.7 (for ABI change made in 966 * 5.7 master). 967 */ 968 sb->__old_st_blksize = sb->st_blksize; 969 970 return (0); 971 } 972 973 /* 974 * MPALMOSTSAFE - acquires mplock 975 */ 976 static int 977 vn_ioctl(struct file *fp, u_long com, caddr_t data, struct ucred *ucred, 978 struct sysmsg *msg) 979 { 980 struct vnode *vp = ((struct vnode *)fp->f_data); 981 struct vnode *ovp; 982 struct vattr vattr; 983 int error; 984 off_t size; 985 986 switch (vp->v_type) { 987 case VREG: 988 case VDIR: 989 if (com == FIONREAD) { 990 error = VOP_GETATTR(vp, &vattr); 991 if (error) 992 break; 993 size = vattr.va_size; 994 if ((vp->v_flag & VNOTSEEKABLE) == 0) 995 size -= vn_poll_fpf_offset(fp); 996 if (size > 0x7FFFFFFF) 997 size = 0x7FFFFFFF; 998 *(int *)data = size; 999 error = 0; 1000 break; 1001 } 1002 if (com == FIOASYNC) { /* XXX */ 1003 error = 0; /* XXX */ 1004 break; 1005 } 1006 /* fall into ... */ 1007 default: 1008 #if 0 1009 return (ENOTTY); 1010 #endif 1011 case VFIFO: 1012 case VCHR: 1013 case VBLK: 1014 if (com == FIODTYPE) { 1015 if (vp->v_type != VCHR && vp->v_type != VBLK) { 1016 error = ENOTTY; 1017 break; 1018 } 1019 *(int *)data = dev_dflags(vp->v_rdev) & D_TYPEMASK; 1020 error = 0; 1021 break; 1022 } 1023 error = VOP_IOCTL(vp, com, data, fp->f_flag, ucred, msg); 1024 if (error == 0 && com == TIOCSCTTY) { 1025 struct proc *p = curthread->td_proc; 1026 struct session *sess; 1027 1028 if (p == NULL) { 1029 error = ENOTTY; 1030 break; 1031 } 1032 1033 get_mplock(); 1034 sess = p->p_session; 1035 /* Do nothing if reassigning same control tty */ 1036 if (sess->s_ttyvp == vp) { 1037 error = 0; 1038 rel_mplock(); 1039 break; 1040 } 1041 1042 /* Get rid of reference to old control tty */ 1043 ovp = sess->s_ttyvp; 1044 vref(vp); 1045 sess->s_ttyvp = vp; 1046 if (ovp) 1047 vrele(ovp); 1048 rel_mplock(); 1049 } 1050 break; 1051 } 1052 return (error); 1053 } 1054 1055 /* 1056 * Obtain the requested vnode lock 1057 * 1058 * LK_RETRY Automatically retry on timeout 1059 * LK_FAILRECLAIM Fail if the vnode is being reclaimed 1060 * 1061 * Failures will occur if the vnode is undergoing recyclement, but not 1062 * all callers expect that the function will fail so the caller must pass 1063 * LK_FAILOK if it wants to process an error code. 1064 * 1065 * Errors can occur for other reasons if you pass in other LK_ flags, 1066 * regardless of whether you pass in LK_FAILRECLAIM 1067 */ 1068 int 1069 vn_lock(struct vnode *vp, int flags) 1070 { 1071 int error; 1072 1073 do { 1074 error = lockmgr(&vp->v_lock, flags); 1075 if (error == 0) 1076 break; 1077 } while (flags & LK_RETRY); 1078 1079 /* 1080 * Because we (had better!) have a ref on the vnode, once it 1081 * goes to VRECLAIMED state it will not be recycled until all 1082 * refs go away. So we can just check the flag. 1083 */ 1084 if (error == 0 && (vp->v_flag & VRECLAIMED)) { 1085 if (flags & LK_FAILRECLAIM) { 1086 lockmgr(&vp->v_lock, LK_RELEASE); 1087 error = ENOENT; 1088 } 1089 } 1090 return (error); 1091 } 1092 1093 int 1094 vn_relock(struct vnode *vp, int flags) 1095 { 1096 int error; 1097 1098 do { 1099 error = lockmgr(&vp->v_lock, flags); 1100 if (error == 0) 1101 break; 1102 } while (flags & LK_RETRY); 1103 1104 return error; 1105 } 1106 1107 #ifdef DEBUG_VN_UNLOCK 1108 1109 void 1110 debug_vn_unlock(struct vnode *vp, const char *filename, int line) 1111 { 1112 kprintf("vn_unlock from %s:%d\n", filename, line); 1113 lockmgr(&vp->v_lock, LK_RELEASE); 1114 } 1115 1116 #else 1117 1118 void 1119 vn_unlock(struct vnode *vp) 1120 { 1121 lockmgr(&vp->v_lock, LK_RELEASE); 1122 } 1123 1124 #endif 1125 1126 /* 1127 * MPSAFE 1128 */ 1129 int 1130 vn_islocked(struct vnode *vp) 1131 { 1132 return (lockstatus(&vp->v_lock, curthread)); 1133 } 1134 1135 /* 1136 * Return the lock status of a vnode and unlock the vnode 1137 * if we owned the lock. This is not a boolean, if the 1138 * caller cares what the lock status is the caller must 1139 * check the various possible values. 1140 * 1141 * This only unlocks exclusive locks held by the caller, 1142 * it will NOT unlock shared locks (there is no way to 1143 * tell who the shared lock belongs to). 1144 * 1145 * MPSAFE 1146 */ 1147 int 1148 vn_islocked_unlock(struct vnode *vp) 1149 { 1150 int vpls; 1151 1152 vpls = lockstatus(&vp->v_lock, curthread); 1153 if (vpls == LK_EXCLUSIVE) 1154 lockmgr(&vp->v_lock, LK_RELEASE); 1155 return(vpls); 1156 } 1157 1158 /* 1159 * Restore a vnode lock that we previously released via 1160 * vn_islocked_unlock(). This is a NOP if we did not 1161 * own the original lock. 1162 * 1163 * MPSAFE 1164 */ 1165 void 1166 vn_islocked_relock(struct vnode *vp, int vpls) 1167 { 1168 int error; 1169 1170 if (vpls == LK_EXCLUSIVE) 1171 error = lockmgr(&vp->v_lock, vpls); 1172 } 1173 1174 /* 1175 * MPSAFE 1176 */ 1177 static int 1178 vn_closefile(struct file *fp) 1179 { 1180 int error; 1181 1182 fp->f_ops = &badfileops; 1183 error = vn_close(((struct vnode *)fp->f_data), fp->f_flag, fp); 1184 return (error); 1185 } 1186 1187 /* 1188 * MPSAFE 1189 */ 1190 static int 1191 vn_kqfilter(struct file *fp, struct knote *kn) 1192 { 1193 int error; 1194 1195 error = VOP_KQFILTER(((struct vnode *)fp->f_data), kn); 1196 return (error); 1197 } 1198 1199 int 1200 vn_seek(struct file *fp, off_t offset, int whence, off_t *res) 1201 { 1202 /* 1203 * NOTE: devfs_dev_fileops uses exact same code 1204 */ 1205 struct vnode *vp; 1206 struct vattr_lite lva; 1207 off_t new_offset; 1208 int error; 1209 1210 vp = (struct vnode *)fp->f_data; 1211 1212 switch (whence) { 1213 case L_INCR: 1214 spin_lock(&fp->f_spin); 1215 new_offset = fp->f_offset + offset; 1216 error = 0; 1217 break; 1218 case L_XTND: 1219 error = VOP_GETATTR_LITE(vp, &lva); 1220 spin_lock(&fp->f_spin); 1221 new_offset = offset + lva.va_size; 1222 break; 1223 case L_SET: 1224 new_offset = offset; 1225 error = 0; 1226 spin_lock(&fp->f_spin); 1227 break; 1228 default: 1229 new_offset = 0; 1230 error = EINVAL; 1231 spin_lock(&fp->f_spin); 1232 break; 1233 } 1234 1235 /* 1236 * Validate the seek position. Negative offsets are not allowed 1237 * for regular files or directories. 1238 * 1239 * Normally we would also not want to allow negative offsets for 1240 * character and block-special devices. However kvm addresses 1241 * on 64 bit architectures might appear to be negative and must 1242 * be allowed. 1243 */ 1244 if (error == 0) { 1245 if (new_offset < 0 && 1246 (vp->v_type == VREG || vp->v_type == VDIR)) { 1247 error = EINVAL; 1248 } else { 1249 fp->f_offset = new_offset; 1250 } 1251 } 1252 *res = fp->f_offset; 1253 spin_unlock(&fp->f_spin); 1254 1255 return (error); 1256 } 1257