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FreeBSD/Linux Kernel Cross Reference
sys/kern/vfs_vnops.c
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1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Copyright (c) 2012 Konstantin Belousov <kib@FreeBSD.org> 13 * Copyright (c) 2013, 2014 The FreeBSD Foundation 14 * 15 * Portions of this software were developed by Konstantin Belousov 16 * under sponsorship from the FreeBSD Foundation. 17 * 18 * Redistribution and use in source and binary forms, with or without 19 * modification, are permitted provided that the following conditions 20 * are met: 21 * 1. Redistributions of source code must retain the above copyright 22 * notice, this list of conditions and the following disclaimer. 23 * 2. Redistributions in binary form must reproduce the above copyright 24 * notice, this list of conditions and the following disclaimer in the 25 * documentation and/or other materials provided with the distribution. 26 * 3. Neither the name of the University nor the names of its contributors 27 * may be used to endorse or promote products derived from this software 28 * without specific prior written permission. 29 * 30 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 31 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 32 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 33 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 34 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 35 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 36 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 37 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 38 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 39 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 40 * SUCH DAMAGE. 41 * 42 * @(#)vfs_vnops.c 8.2 (Berkeley) 1/21/94 43 */ 44 45 #include <sys/cdefs.h> 46 __FBSDID("$FreeBSD$"); 47 48 #include "opt_hwpmc_hooks.h" 49 50 #include <sys/param.h> 51 #include <sys/systm.h> 52 #include <sys/disk.h> 53 #include <sys/fail.h> 54 #include <sys/fcntl.h> 55 #include <sys/file.h> 56 #include <sys/kdb.h> 57 #include <sys/stat.h> 58 #include <sys/priv.h> 59 #include <sys/proc.h> 60 #include <sys/limits.h> 61 #include <sys/lock.h> 62 #include <sys/mman.h> 63 #include <sys/mount.h> 64 #include <sys/mutex.h> 65 #include <sys/namei.h> 66 #include <sys/vnode.h> 67 #include <sys/bio.h> 68 #include <sys/buf.h> 69 #include <sys/filio.h> 70 #include <sys/resourcevar.h> 71 #include <sys/rwlock.h> 72 #include <sys/sx.h> 73 #include <sys/sysctl.h> 74 #include <sys/ttycom.h> 75 #include <sys/conf.h> 76 #include <sys/syslog.h> 77 #include <sys/unistd.h> 78 #include <sys/user.h> 79 80 #include <security/audit/audit.h> 81 #include <security/mac/mac_framework.h> 82 83 #include <vm/vm.h> 84 #include <vm/vm_extern.h> 85 #include <vm/pmap.h> 86 #include <vm/vm_map.h> 87 #include <vm/vm_object.h> 88 #include <vm/vm_page.h> 89 #include <vm/vm_pager.h> 90 91 #ifdef HWPMC_HOOKS 92 #include <sys/pmckern.h> 93 #endif 94 95 static fo_rdwr_t vn_read; 96 static fo_rdwr_t vn_write; 97 static fo_rdwr_t vn_io_fault; 98 static fo_truncate_t vn_truncate; 99 static fo_ioctl_t vn_ioctl; 100 static fo_poll_t vn_poll; 101 static fo_kqfilter_t vn_kqfilter; 102 static fo_stat_t vn_statfile; 103 static fo_close_t vn_closefile; 104 static fo_mmap_t vn_mmap; 105 106 struct fileops vnops = { 107 .fo_read = vn_io_fault, 108 .fo_write = vn_io_fault, 109 .fo_truncate = vn_truncate, 110 .fo_ioctl = vn_ioctl, 111 .fo_poll = vn_poll, 112 .fo_kqfilter = vn_kqfilter, 113 .fo_stat = vn_statfile, 114 .fo_close = vn_closefile, 115 .fo_chmod = vn_chmod, 116 .fo_chown = vn_chown, 117 .fo_sendfile = vn_sendfile, 118 .fo_seek = vn_seek, 119 .fo_fill_kinfo = vn_fill_kinfo, 120 .fo_mmap = vn_mmap, 121 .fo_flags = DFLAG_PASSABLE | DFLAG_SEEKABLE 122 }; 123 124 static const int io_hold_cnt = 16; 125 static int vn_io_fault_enable = 1; 126 SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_enable, CTLFLAG_RW, 127 &vn_io_fault_enable, 0, "Enable vn_io_fault lock avoidance"); 128 static int vn_io_fault_prefault = 0; 129 SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_prefault, CTLFLAG_RW, 130 &vn_io_fault_prefault, 0, "Enable vn_io_fault prefaulting"); 131 static u_long vn_io_faults_cnt; 132 SYSCTL_ULONG(_debug, OID_AUTO, vn_io_faults, CTLFLAG_RD, 133 &vn_io_faults_cnt, 0, "Count of vn_io_fault lock avoidance triggers"); 134 135 static int vfs_allow_read_dir = 0; 136 SYSCTL_INT(_security_bsd, OID_AUTO, allow_read_dir, CTLFLAG_RW, 137 &vfs_allow_read_dir, 0, 138 "Enable read(2) of directory for filesystems that support it"); 139 140 /* 141 * Returns true if vn_io_fault mode of handling the i/o request should 142 * be used. 143 */ 144 static bool 145 do_vn_io_fault(struct vnode *vp, struct uio *uio) 146 { 147 struct mount *mp; 148 149 return (uio->uio_segflg == UIO_USERSPACE && vp->v_type == VREG && 150 (mp = vp->v_mount) != NULL && 151 (mp->mnt_kern_flag & MNTK_NO_IOPF) != 0 && vn_io_fault_enable); 152 } 153 154 /* 155 * Structure used to pass arguments to vn_io_fault1(), to do either 156 * file- or vnode-based I/O calls. 157 */ 158 struct vn_io_fault_args { 159 enum { 160 VN_IO_FAULT_FOP, 161 VN_IO_FAULT_VOP 162 } kind; 163 struct ucred *cred; 164 int flags; 165 union { 166 struct fop_args_tag { 167 struct file *fp; 168 fo_rdwr_t *doio; 169 } fop_args; 170 struct vop_args_tag { 171 struct vnode *vp; 172 } vop_args; 173 } args; 174 }; 175 176 static int vn_io_fault1(struct vnode *vp, struct uio *uio, 177 struct vn_io_fault_args *args, struct thread *td); 178 179 int 180 vn_open(struct nameidata *ndp, int *flagp, int cmode, struct file *fp) 181 { 182 struct thread *td = ndp->ni_cnd.cn_thread; 183 184 return (vn_open_cred(ndp, flagp, cmode, 0, td->td_ucred, fp)); 185 } 186 187 static uint64_t 188 open2nameif(int fmode, u_int vn_open_flags) 189 { 190 uint64_t res; 191 192 res = ISOPEN | LOCKLEAF; 193 if ((fmode & O_RESOLVE_BENEATH) != 0) 194 res |= RBENEATH; 195 if ((vn_open_flags & VN_OPEN_NOAUDIT) == 0) 196 res |= AUDITVNODE1; 197 if ((vn_open_flags & VN_OPEN_NOCAPCHECK) != 0) 198 res |= NOCAPCHECK; 199 return (res); 200 } 201 202 /* 203 * Common code for vnode open operations via a name lookup. 204 * Lookup the vnode and invoke VOP_CREATE if needed. 205 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine. 206 * 207 * Note that this does NOT free nameidata for the successful case, 208 * due to the NDINIT being done elsewhere. 209 */ 210 int 211 vn_open_cred(struct nameidata *ndp, int *flagp, int cmode, u_int vn_open_flags, 212 struct ucred *cred, struct file *fp) 213 { 214 struct vnode *vp; 215 struct mount *mp; 216 struct thread *td = ndp->ni_cnd.cn_thread; 217 struct vattr vat; 218 struct vattr *vap = &vat; 219 int fmode, error; 220 221 restart: 222 fmode = *flagp; 223 if ((fmode & (O_CREAT | O_EXCL | O_DIRECTORY)) == (O_CREAT | 224 O_EXCL | O_DIRECTORY)) 225 return (EINVAL); 226 else if ((fmode & (O_CREAT | O_DIRECTORY)) == O_CREAT) { 227 ndp->ni_cnd.cn_nameiop = CREATE; 228 ndp->ni_cnd.cn_flags = open2nameif(fmode, vn_open_flags); 229 /* 230 * Set NOCACHE to avoid flushing the cache when 231 * rolling in many files at once. 232 */ 233 ndp->ni_cnd.cn_flags |= LOCKPARENT | NOCACHE; 234 if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0) 235 ndp->ni_cnd.cn_flags |= FOLLOW; 236 if ((vn_open_flags & VN_OPEN_INVFS) == 0) 237 bwillwrite(); 238 if ((error = namei(ndp)) != 0) 239 return (error); 240 if (ndp->ni_vp == NULL) { 241 VATTR_NULL(vap); 242 vap->va_type = VREG; 243 vap->va_mode = cmode; 244 if (fmode & O_EXCL) 245 vap->va_vaflags |= VA_EXCLUSIVE; 246 if (vn_start_write(ndp->ni_dvp, &mp, V_NOWAIT) != 0) { 247 NDFREE(ndp, NDF_ONLY_PNBUF); 248 vput(ndp->ni_dvp); 249 if ((error = vn_start_write(NULL, &mp, 250 V_XSLEEP | PCATCH)) != 0) 251 return (error); 252 goto restart; 253 } 254 if ((vn_open_flags & VN_OPEN_NAMECACHE) != 0) 255 ndp->ni_cnd.cn_flags |= MAKEENTRY; 256 #ifdef MAC 257 error = mac_vnode_check_create(cred, ndp->ni_dvp, 258 &ndp->ni_cnd, vap); 259 if (error == 0) 260 #endif 261 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp, 262 &ndp->ni_cnd, vap); 263 vput(ndp->ni_dvp); 264 vn_finished_write(mp); 265 if (error) { 266 NDFREE(ndp, NDF_ONLY_PNBUF); 267 return (error); 268 } 269 fmode &= ~O_TRUNC; 270 vp = ndp->ni_vp; 271 } else { 272 if (ndp->ni_dvp == ndp->ni_vp) 273 vrele(ndp->ni_dvp); 274 else 275 vput(ndp->ni_dvp); 276 ndp->ni_dvp = NULL; 277 vp = ndp->ni_vp; 278 if (fmode & O_EXCL) { 279 error = EEXIST; 280 goto bad; 281 } 282 if (vp->v_type == VDIR) { 283 error = EISDIR; 284 goto bad; 285 } 286 fmode &= ~O_CREAT; 287 } 288 } else { 289 ndp->ni_cnd.cn_nameiop = LOOKUP; 290 ndp->ni_cnd.cn_flags = open2nameif(fmode, vn_open_flags); 291 ndp->ni_cnd.cn_flags |= (fmode & O_NOFOLLOW) != 0 ? NOFOLLOW : 292 FOLLOW; 293 if ((fmode & FWRITE) == 0) 294 ndp->ni_cnd.cn_flags |= LOCKSHARED; 295 if ((error = namei(ndp)) != 0) 296 return (error); 297 vp = ndp->ni_vp; 298 } 299 error = vn_open_vnode(vp, fmode, cred, td, fp); 300 if (error) 301 goto bad; 302 *flagp = fmode; 303 return (0); 304 bad: 305 NDFREE(ndp, NDF_ONLY_PNBUF); 306 vput(vp); 307 *flagp = fmode; 308 ndp->ni_vp = NULL; 309 return (error); 310 } 311 312 static int 313 vn_open_vnode_advlock(struct vnode *vp, int fmode, struct file *fp) 314 { 315 struct flock lf; 316 int error, lock_flags, type; 317 318 ASSERT_VOP_LOCKED(vp, "vn_open_vnode_advlock"); 319 if ((fmode & (O_EXLOCK | O_SHLOCK)) == 0) 320 return (0); 321 KASSERT(fp != NULL, ("open with flock requires fp")); 322 if (fp->f_type != DTYPE_NONE && fp->f_type != DTYPE_VNODE) 323 return (EOPNOTSUPP); 324 325 lock_flags = VOP_ISLOCKED(vp); 326 VOP_UNLOCK(vp, 0); 327 328 lf.l_whence = SEEK_SET; 329 lf.l_start = 0; 330 lf.l_len = 0; 331 lf.l_type = (fmode & O_EXLOCK) != 0 ? F_WRLCK : F_RDLCK; 332 type = F_FLOCK; 333 if ((fmode & FNONBLOCK) == 0) 334 type |= F_WAIT; 335 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, type); 336 if (error == 0) 337 fp->f_flag |= FHASLOCK; 338 339 vn_lock(vp, lock_flags | LK_RETRY); 340 if (error == 0 && (vp->v_iflag & VI_DOOMED) != 0) 341 error = ENOENT; 342 return (error); 343 } 344 345 /* 346 * Common code for vnode open operations once a vnode is located. 347 * Check permissions, and call the VOP_OPEN routine. 348 */ 349 int 350 vn_open_vnode(struct vnode *vp, int fmode, struct ucred *cred, 351 struct thread *td, struct file *fp) 352 { 353 accmode_t accmode; 354 int error; 355 356 if (vp->v_type == VLNK) 357 return (EMLINK); 358 if (vp->v_type == VSOCK) 359 return (EOPNOTSUPP); 360 if (vp->v_type != VDIR && fmode & O_DIRECTORY) 361 return (ENOTDIR); 362 accmode = 0; 363 if (fmode & (FWRITE | O_TRUNC)) { 364 if (vp->v_type == VDIR) 365 return (EISDIR); 366 accmode |= VWRITE; 367 } 368 if (fmode & FREAD) 369 accmode |= VREAD; 370 if (fmode & FEXEC) 371 accmode |= VEXEC; 372 if ((fmode & O_APPEND) && (fmode & FWRITE)) 373 accmode |= VAPPEND; 374 #ifdef MAC 375 if (fmode & O_CREAT) 376 accmode |= VCREAT; 377 if (fmode & O_VERIFY) 378 accmode |= VVERIFY; 379 error = mac_vnode_check_open(cred, vp, accmode); 380 if (error) 381 return (error); 382 383 accmode &= ~(VCREAT | VVERIFY); 384 #endif 385 if ((fmode & O_CREAT) == 0 && accmode != 0) { 386 error = VOP_ACCESS(vp, accmode, cred, td); 387 if (error != 0) 388 return (error); 389 } 390 if (vp->v_type == VFIFO && VOP_ISLOCKED(vp) != LK_EXCLUSIVE) 391 vn_lock(vp, LK_UPGRADE | LK_RETRY); 392 error = VOP_OPEN(vp, fmode, cred, td, fp); 393 if (error != 0) 394 return (error); 395 396 error = vn_open_vnode_advlock(vp, fmode, fp); 397 if (error == 0 && (fmode & FWRITE) != 0) { 398 error = VOP_ADD_WRITECOUNT(vp, 1); 399 if (error == 0) { 400 CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d", 401 __func__, vp, vp->v_writecount); 402 } 403 } 404 405 /* 406 * Error from advlock or VOP_ADD_WRITECOUNT() still requires 407 * calling VOP_CLOSE() to pair with earlier VOP_OPEN(). 408 */ 409 if (error != 0) { 410 if (fp != NULL) { 411 /* 412 * Arrange the call by having fdrop() to use 413 * vn_closefile(). This is to satisfy 414 * filesystems like devfs or tmpfs, which 415 * override fo_close(). 416 */ 417 fp->f_flag |= FOPENFAILED; 418 fp->f_vnode = vp; 419 if (fp->f_ops == &badfileops) { 420 fp->f_type = DTYPE_VNODE; 421 fp->f_ops = &vnops; 422 } 423 vref(vp); 424 } else { 425 /* 426 * If there is no fp, due to kernel-mode open, 427 * we can call VOP_CLOSE() now. 428 */ 429 if (vp->v_type != VFIFO && (fmode & FWRITE) != 0 && 430 !MNT_EXTENDED_SHARED(vp->v_mount) && 431 VOP_ISLOCKED(vp) != LK_EXCLUSIVE) 432 vn_lock(vp, LK_UPGRADE | LK_RETRY); 433 (void)VOP_CLOSE(vp, fmode & (FREAD | FWRITE | FEXEC), 434 cred, td); 435 } 436 } 437 438 ASSERT_VOP_LOCKED(vp, "vn_open_vnode"); 439 return (error); 440 441 } 442 443 /* 444 * Check for write permissions on the specified vnode. 445 * Prototype text segments cannot be written. 446 * It is racy. 447 */ 448 int 449 vn_writechk(struct vnode *vp) 450 { 451 452 ASSERT_VOP_LOCKED(vp, "vn_writechk"); 453 /* 454 * If there's shared text associated with 455 * the vnode, try to free it up once. If 456 * we fail, we can't allow writing. 457 */ 458 if (VOP_IS_TEXT(vp)) 459 return (ETXTBSY); 460 461 return (0); 462 } 463 464 /* 465 * Vnode close call 466 */ 467 static int 468 vn_close1(struct vnode *vp, int flags, struct ucred *file_cred, 469 struct thread *td, bool keep_ref) 470 { 471 struct mount *mp; 472 int error, lock_flags; 473 474 if (vp->v_type != VFIFO && (flags & FWRITE) == 0 && 475 MNT_EXTENDED_SHARED(vp->v_mount)) 476 lock_flags = LK_SHARED; 477 else 478 lock_flags = LK_EXCLUSIVE; 479 480 vn_start_write(vp, &mp, V_WAIT); 481 vn_lock(vp, lock_flags | LK_RETRY); 482 AUDIT_ARG_VNODE1(vp); 483 if ((flags & (FWRITE | FOPENFAILED)) == FWRITE) { 484 VOP_ADD_WRITECOUNT_CHECKED(vp, -1); 485 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d", 486 __func__, vp, vp->v_writecount); 487 } 488 error = VOP_CLOSE(vp, flags, file_cred, td); 489 if (keep_ref) 490 VOP_UNLOCK(vp, 0); 491 else 492 vput(vp); 493 vn_finished_write(mp); 494 return (error); 495 } 496 497 int 498 vn_close(struct vnode *vp, int flags, struct ucred *file_cred, 499 struct thread *td) 500 { 501 502 return (vn_close1(vp, flags, file_cred, td, false)); 503 } 504 505 /* 506 * Heuristic to detect sequential operation. 507 */ 508 static int 509 sequential_heuristic(struct uio *uio, struct file *fp) 510 { 511 512 ASSERT_VOP_LOCKED(fp->f_vnode, __func__); 513 if (fp->f_flag & FRDAHEAD) 514 return (fp->f_seqcount << IO_SEQSHIFT); 515 516 /* 517 * Offset 0 is handled specially. open() sets f_seqcount to 1 so 518 * that the first I/O is normally considered to be slightly 519 * sequential. Seeking to offset 0 doesn't change sequentiality 520 * unless previous seeks have reduced f_seqcount to 0, in which 521 * case offset 0 is not special. 522 */ 523 if ((uio->uio_offset == 0 && fp->f_seqcount > 0) || 524 uio->uio_offset == fp->f_nextoff) { 525 /* 526 * f_seqcount is in units of fixed-size blocks so that it 527 * depends mainly on the amount of sequential I/O and not 528 * much on the number of sequential I/O's. The fixed size 529 * of 16384 is hard-coded here since it is (not quite) just 530 * a magic size that works well here. This size is more 531 * closely related to the best I/O size for real disks than 532 * to any block size used by software. 533 */ 534 if (uio->uio_resid >= IO_SEQMAX * 16384) 535 fp->f_seqcount = IO_SEQMAX; 536 else { 537 fp->f_seqcount += howmany(uio->uio_resid, 16384); 538 if (fp->f_seqcount > IO_SEQMAX) 539 fp->f_seqcount = IO_SEQMAX; 540 } 541 return (fp->f_seqcount << IO_SEQSHIFT); 542 } 543 544 /* Not sequential. Quickly draw-down sequentiality. */ 545 if (fp->f_seqcount > 1) 546 fp->f_seqcount = 1; 547 else 548 fp->f_seqcount = 0; 549 return (0); 550 } 551 552 /* 553 * Package up an I/O request on a vnode into a uio and do it. 554 */ 555 int 556 vn_rdwr(enum uio_rw rw, struct vnode *vp, void *base, int len, off_t offset, 557 enum uio_seg segflg, int ioflg, struct ucred *active_cred, 558 struct ucred *file_cred, ssize_t *aresid, struct thread *td) 559 { 560 struct uio auio; 561 struct iovec aiov; 562 struct mount *mp; 563 struct ucred *cred; 564 void *rl_cookie; 565 struct vn_io_fault_args args; 566 int error, lock_flags; 567 568 if (offset < 0 && vp->v_type != VCHR) 569 return (EINVAL); 570 auio.uio_iov = &aiov; 571 auio.uio_iovcnt = 1; 572 aiov.iov_base = base; 573 aiov.iov_len = len; 574 auio.uio_resid = len; 575 auio.uio_offset = offset; 576 auio.uio_segflg = segflg; 577 auio.uio_rw = rw; 578 auio.uio_td = td; 579 error = 0; 580 581 if ((ioflg & IO_NODELOCKED) == 0) { 582 if ((ioflg & IO_RANGELOCKED) == 0) { 583 if (rw == UIO_READ) { 584 rl_cookie = vn_rangelock_rlock(vp, offset, 585 offset + len); 586 } else { 587 rl_cookie = vn_rangelock_wlock(vp, offset, 588 offset + len); 589 } 590 } else 591 rl_cookie = NULL; 592 mp = NULL; 593 if (rw == UIO_WRITE) { 594 if (vp->v_type != VCHR && 595 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) 596 != 0) 597 goto out; 598 if (MNT_SHARED_WRITES(mp) || 599 ((mp == NULL) && MNT_SHARED_WRITES(vp->v_mount))) 600 lock_flags = LK_SHARED; 601 else 602 lock_flags = LK_EXCLUSIVE; 603 } else 604 lock_flags = LK_SHARED; 605 vn_lock(vp, lock_flags | LK_RETRY); 606 } else 607 rl_cookie = NULL; 608 609 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 610 #ifdef MAC 611 if ((ioflg & IO_NOMACCHECK) == 0) { 612 if (rw == UIO_READ) 613 error = mac_vnode_check_read(active_cred, file_cred, 614 vp); 615 else 616 error = mac_vnode_check_write(active_cred, file_cred, 617 vp); 618 } 619 #endif 620 if (error == 0) { 621 if (file_cred != NULL) 622 cred = file_cred; 623 else 624 cred = active_cred; 625 if (do_vn_io_fault(vp, &auio)) { 626 args.kind = VN_IO_FAULT_VOP; 627 args.cred = cred; 628 args.flags = ioflg; 629 args.args.vop_args.vp = vp; 630 error = vn_io_fault1(vp, &auio, &args, td); 631 } else if (rw == UIO_READ) { 632 error = VOP_READ(vp, &auio, ioflg, cred); 633 } else /* if (rw == UIO_WRITE) */ { 634 error = VOP_WRITE(vp, &auio, ioflg, cred); 635 } 636 } 637 if (aresid) 638 *aresid = auio.uio_resid; 639 else 640 if (auio.uio_resid && error == 0) 641 error = EIO; 642 if ((ioflg & IO_NODELOCKED) == 0) { 643 VOP_UNLOCK(vp, 0); 644 if (mp != NULL) 645 vn_finished_write(mp); 646 } 647 out: 648 if (rl_cookie != NULL) 649 vn_rangelock_unlock(vp, rl_cookie); 650 return (error); 651 } 652 653 /* 654 * Package up an I/O request on a vnode into a uio and do it. The I/O 655 * request is split up into smaller chunks and we try to avoid saturating 656 * the buffer cache while potentially holding a vnode locked, so we 657 * check bwillwrite() before calling vn_rdwr(). We also call kern_yield() 658 * to give other processes a chance to lock the vnode (either other processes 659 * core'ing the same binary, or unrelated processes scanning the directory). 660 */ 661 int 662 vn_rdwr_inchunks(enum uio_rw rw, struct vnode *vp, void *base, size_t len, 663 off_t offset, enum uio_seg segflg, int ioflg, struct ucred *active_cred, 664 struct ucred *file_cred, size_t *aresid, struct thread *td) 665 { 666 int error = 0; 667 ssize_t iaresid; 668 669 do { 670 int chunk; 671 672 /* 673 * Force `offset' to a multiple of MAXBSIZE except possibly 674 * for the first chunk, so that filesystems only need to 675 * write full blocks except possibly for the first and last 676 * chunks. 677 */ 678 chunk = MAXBSIZE - (uoff_t)offset % MAXBSIZE; 679 680 if (chunk > len) 681 chunk = len; 682 if (rw != UIO_READ && vp->v_type == VREG) 683 bwillwrite(); 684 iaresid = 0; 685 error = vn_rdwr(rw, vp, base, chunk, offset, segflg, 686 ioflg, active_cred, file_cred, &iaresid, td); 687 len -= chunk; /* aresid calc already includes length */ 688 if (error) 689 break; 690 offset += chunk; 691 base = (char *)base + chunk; 692 kern_yield(PRI_USER); 693 } while (len); 694 if (aresid) 695 *aresid = len + iaresid; 696 return (error); 697 } 698 699 off_t 700 foffset_lock(struct file *fp, int flags) 701 { 702 struct mtx *mtxp; 703 off_t res; 704 705 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed")); 706 707 #if OFF_MAX <= LONG_MAX 708 /* 709 * Caller only wants the current f_offset value. Assume that 710 * the long and shorter integer types reads are atomic. 711 */ 712 if ((flags & FOF_NOLOCK) != 0) 713 return (fp->f_offset); 714 #endif 715 716 /* 717 * According to McKusick the vn lock was protecting f_offset here. 718 * It is now protected by the FOFFSET_LOCKED flag. 719 */ 720 mtxp = mtx_pool_find(mtxpool_sleep, fp); 721 mtx_lock(mtxp); 722 if ((flags & FOF_NOLOCK) == 0) { 723 while (fp->f_vnread_flags & FOFFSET_LOCKED) { 724 fp->f_vnread_flags |= FOFFSET_LOCK_WAITING; 725 msleep(&fp->f_vnread_flags, mtxp, PUSER -1, 726 "vofflock", 0); 727 } 728 fp->f_vnread_flags |= FOFFSET_LOCKED; 729 } 730 res = fp->f_offset; 731 mtx_unlock(mtxp); 732 return (res); 733 } 734 735 void 736 foffset_unlock(struct file *fp, off_t val, int flags) 737 { 738 struct mtx *mtxp; 739 740 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed")); 741 742 #if OFF_MAX <= LONG_MAX 743 if ((flags & FOF_NOLOCK) != 0) { 744 if ((flags & FOF_NOUPDATE) == 0) 745 fp->f_offset = val; 746 if ((flags & FOF_NEXTOFF) != 0) 747 fp->f_nextoff = val; 748 return; 749 } 750 #endif 751 752 mtxp = mtx_pool_find(mtxpool_sleep, fp); 753 mtx_lock(mtxp); 754 if ((flags & FOF_NOUPDATE) == 0) 755 fp->f_offset = val; 756 if ((flags & FOF_NEXTOFF) != 0) 757 fp->f_nextoff = val; 758 if ((flags & FOF_NOLOCK) == 0) { 759 KASSERT((fp->f_vnread_flags & FOFFSET_LOCKED) != 0, 760 ("Lost FOFFSET_LOCKED")); 761 if (fp->f_vnread_flags & FOFFSET_LOCK_WAITING) 762 wakeup(&fp->f_vnread_flags); 763 fp->f_vnread_flags = 0; 764 } 765 mtx_unlock(mtxp); 766 } 767 768 void 769 foffset_lock_uio(struct file *fp, struct uio *uio, int flags) 770 { 771 772 if ((flags & FOF_OFFSET) == 0) 773 uio->uio_offset = foffset_lock(fp, flags); 774 } 775 776 void 777 foffset_unlock_uio(struct file *fp, struct uio *uio, int flags) 778 { 779 780 if ((flags & FOF_OFFSET) == 0) 781 foffset_unlock(fp, uio->uio_offset, flags); 782 } 783 784 static int 785 get_advice(struct file *fp, struct uio *uio) 786 { 787 struct mtx *mtxp; 788 int ret; 789 790 ret = POSIX_FADV_NORMAL; 791 if (fp->f_advice == NULL || fp->f_vnode->v_type != VREG) 792 return (ret); 793 794 mtxp = mtx_pool_find(mtxpool_sleep, fp); 795 mtx_lock(mtxp); 796 if (fp->f_advice != NULL && 797 uio->uio_offset >= fp->f_advice->fa_start && 798 uio->uio_offset + uio->uio_resid <= fp->f_advice->fa_end) 799 ret = fp->f_advice->fa_advice; 800 mtx_unlock(mtxp); 801 return (ret); 802 } 803 804 /* 805 * File table vnode read routine. 806 */ 807 static int 808 vn_read(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags, 809 struct thread *td) 810 { 811 struct vnode *vp; 812 off_t orig_offset; 813 int error, ioflag; 814 int advice; 815 816 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", 817 uio->uio_td, td)); 818 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET")); 819 vp = fp->f_vnode; 820 ioflag = 0; 821 if (fp->f_flag & FNONBLOCK) 822 ioflag |= IO_NDELAY; 823 if (fp->f_flag & O_DIRECT) 824 ioflag |= IO_DIRECT; 825 advice = get_advice(fp, uio); 826 vn_lock(vp, LK_SHARED | LK_RETRY); 827 828 switch (advice) { 829 case POSIX_FADV_NORMAL: 830 case POSIX_FADV_SEQUENTIAL: 831 case POSIX_FADV_NOREUSE: 832 ioflag |= sequential_heuristic(uio, fp); 833 break; 834 case POSIX_FADV_RANDOM: 835 /* Disable read-ahead for random I/O. */ 836 break; 837 } 838 orig_offset = uio->uio_offset; 839 840 #ifdef MAC 841 error = mac_vnode_check_read(active_cred, fp->f_cred, vp); 842 if (error == 0) 843 #endif 844 error = VOP_READ(vp, uio, ioflag, fp->f_cred); 845 fp->f_nextoff = uio->uio_offset; 846 VOP_UNLOCK(vp, 0); 847 if (error == 0 && advice == POSIX_FADV_NOREUSE && 848 orig_offset != uio->uio_offset) 849 /* 850 * Use POSIX_FADV_DONTNEED to flush pages and buffers 851 * for the backing file after a POSIX_FADV_NOREUSE 852 * read(2). 853 */ 854 error = VOP_ADVISE(vp, orig_offset, uio->uio_offset - 1, 855 POSIX_FADV_DONTNEED); 856 return (error); 857 } 858 859 /* 860 * File table vnode write routine. 861 */ 862 static int 863 vn_write(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags, 864 struct thread *td) 865 { 866 struct vnode *vp; 867 struct mount *mp; 868 off_t orig_offset; 869 int error, ioflag, lock_flags; 870 int advice; 871 872 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", 873 uio->uio_td, td)); 874 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET")); 875 vp = fp->f_vnode; 876 if (vp->v_type == VREG) 877 bwillwrite(); 878 ioflag = IO_UNIT; 879 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 880 ioflag |= IO_APPEND; 881 if (fp->f_flag & FNONBLOCK) 882 ioflag |= IO_NDELAY; 883 if (fp->f_flag & O_DIRECT) 884 ioflag |= IO_DIRECT; 885 if ((fp->f_flag & O_FSYNC) || 886 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS))) 887 ioflag |= IO_SYNC; 888 mp = NULL; 889 if (vp->v_type != VCHR && 890 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0) 891 goto unlock; 892 893 advice = get_advice(fp, uio); 894 895 if (MNT_SHARED_WRITES(mp) || 896 (mp == NULL && MNT_SHARED_WRITES(vp->v_mount))) { 897 lock_flags = LK_SHARED; 898 } else { 899 lock_flags = LK_EXCLUSIVE; 900 } 901 902 vn_lock(vp, lock_flags | LK_RETRY); 903 switch (advice) { 904 case POSIX_FADV_NORMAL: 905 case POSIX_FADV_SEQUENTIAL: 906 case POSIX_FADV_NOREUSE: 907 ioflag |= sequential_heuristic(uio, fp); 908 break; 909 case POSIX_FADV_RANDOM: 910 /* XXX: Is this correct? */ 911 break; 912 } 913 orig_offset = uio->uio_offset; 914 915 #ifdef MAC 916 error = mac_vnode_check_write(active_cred, fp->f_cred, vp); 917 if (error == 0) 918 #endif 919 error = VOP_WRITE(vp, uio, ioflag, fp->f_cred); 920 fp->f_nextoff = uio->uio_offset; 921 VOP_UNLOCK(vp, 0); 922 if (vp->v_type != VCHR) 923 vn_finished_write(mp); 924 if (error == 0 && advice == POSIX_FADV_NOREUSE && 925 orig_offset != uio->uio_offset) 926 /* 927 * Use POSIX_FADV_DONTNEED to flush pages and buffers 928 * for the backing file after a POSIX_FADV_NOREUSE 929 * write(2). 930 */ 931 error = VOP_ADVISE(vp, orig_offset, uio->uio_offset - 1, 932 POSIX_FADV_DONTNEED); 933 unlock: 934 return (error); 935 } 936 937 /* 938 * The vn_io_fault() is a wrapper around vn_read() and vn_write() to 939 * prevent the following deadlock: 940 * 941 * Assume that the thread A reads from the vnode vp1 into userspace 942 * buffer buf1 backed by the pages of vnode vp2. If a page in buf1 is 943 * currently not resident, then system ends up with the call chain 944 * vn_read() -> VOP_READ(vp1) -> uiomove() -> [Page Fault] -> 945 * vm_fault(buf1) -> vnode_pager_getpages(vp2) -> VOP_GETPAGES(vp2) 946 * which establishes lock order vp1->vn_lock, then vp2->vn_lock. 947 * If, at the same time, thread B reads from vnode vp2 into buffer buf2 948 * backed by the pages of vnode vp1, and some page in buf2 is not 949 * resident, we get a reversed order vp2->vn_lock, then vp1->vn_lock. 950 * 951 * To prevent the lock order reversal and deadlock, vn_io_fault() does 952 * not allow page faults to happen during VOP_READ() or VOP_WRITE(). 953 * Instead, it first tries to do the whole range i/o with pagefaults 954 * disabled. If all pages in the i/o buffer are resident and mapped, 955 * VOP will succeed (ignoring the genuine filesystem errors). 956 * Otherwise, we get back EFAULT, and vn_io_fault() falls back to do 957 * i/o in chunks, with all pages in the chunk prefaulted and held 958 * using vm_fault_quick_hold_pages(). 959 * 960 * Filesystems using this deadlock avoidance scheme should use the 961 * array of the held pages from uio, saved in the curthread->td_ma, 962 * instead of doing uiomove(). A helper function 963 * vn_io_fault_uiomove() converts uiomove request into 964 * uiomove_fromphys() over td_ma array. 965 * 966 * Since vnode locks do not cover the whole i/o anymore, rangelocks 967 * make the current i/o request atomic with respect to other i/os and 968 * truncations. 969 */ 970 971 /* 972 * Decode vn_io_fault_args and perform the corresponding i/o. 973 */ 974 static int 975 vn_io_fault_doio(struct vn_io_fault_args *args, struct uio *uio, 976 struct thread *td) 977 { 978 int error, save; 979 980 error = 0; 981 save = vm_fault_disable_pagefaults(); 982 switch (args->kind) { 983 case VN_IO_FAULT_FOP: 984 error = (args->args.fop_args.doio)(args->args.fop_args.fp, 985 uio, args->cred, args->flags, td); 986 break; 987 case VN_IO_FAULT_VOP: 988 if (uio->uio_rw == UIO_READ) { 989 error = VOP_READ(args->args.vop_args.vp, uio, 990 args->flags, args->cred); 991 } else if (uio->uio_rw == UIO_WRITE) { 992 error = VOP_WRITE(args->args.vop_args.vp, uio, 993 args->flags, args->cred); 994 } 995 break; 996 default: 997 panic("vn_io_fault_doio: unknown kind of io %d %d", 998 args->kind, uio->uio_rw); 999 } 1000 vm_fault_enable_pagefaults(save); 1001 return (error); 1002 } 1003 1004 static int 1005 vn_io_fault_touch(char *base, const struct uio *uio) 1006 { 1007 int r; 1008 1009 r = fubyte(base); 1010 if (r == -1 || (uio->uio_rw == UIO_READ && subyte(base, r) == -1)) 1011 return (EFAULT); 1012 return (0); 1013 } 1014 1015 static int 1016 vn_io_fault_prefault_user(const struct uio *uio) 1017 { 1018 char *base; 1019 const struct iovec *iov; 1020 size_t len; 1021 ssize_t resid; 1022 int error, i; 1023 1024 KASSERT(uio->uio_segflg == UIO_USERSPACE, 1025 ("vn_io_fault_prefault userspace")); 1026 1027 error = i = 0; 1028 iov = uio->uio_iov; 1029 resid = uio->uio_resid; 1030 base = iov->iov_base; 1031 len = iov->iov_len; 1032 while (resid > 0) { 1033 error = vn_io_fault_touch(base, uio); 1034 if (error != 0) 1035 break; 1036 if (len < PAGE_SIZE) { 1037 if (len != 0) { 1038 error = vn_io_fault_touch(base + len - 1, uio); 1039 if (error != 0) 1040 break; 1041 resid -= len; 1042 } 1043 if (++i >= uio->uio_iovcnt) 1044 break; 1045 iov = uio->uio_iov + i; 1046 base = iov->iov_base; 1047 len = iov->iov_len; 1048 } else { 1049 len -= PAGE_SIZE; 1050 base += PAGE_SIZE; 1051 resid -= PAGE_SIZE; 1052 } 1053 } 1054 return (error); 1055 } 1056 1057 /* 1058 * Common code for vn_io_fault(), agnostic to the kind of i/o request. 1059 * Uses vn_io_fault_doio() to make the call to an actual i/o function. 1060 * Used from vn_rdwr() and vn_io_fault(), which encode the i/o request 1061 * into args and call vn_io_fault1() to handle faults during the user 1062 * mode buffer accesses. 1063 */ 1064 static int 1065 vn_io_fault1(struct vnode *vp, struct uio *uio, struct vn_io_fault_args *args, 1066 struct thread *td) 1067 { 1068 vm_page_t ma[io_hold_cnt + 2]; 1069 struct uio *uio_clone, short_uio; 1070 struct iovec short_iovec[1]; 1071 vm_page_t *prev_td_ma; 1072 vm_prot_t prot; 1073 vm_offset_t addr, end; 1074 size_t len, resid; 1075 ssize_t adv; 1076 int error, cnt, saveheld, prev_td_ma_cnt; 1077 1078 if (vn_io_fault_prefault) { 1079 error = vn_io_fault_prefault_user(uio); 1080 if (error != 0) 1081 return (error); /* Or ignore ? */ 1082 } 1083 1084 prot = uio->uio_rw == UIO_READ ? VM_PROT_WRITE : VM_PROT_READ; 1085 1086 /* 1087 * The UFS follows IO_UNIT directive and replays back both 1088 * uio_offset and uio_resid if an error is encountered during the 1089 * operation. But, since the iovec may be already advanced, 1090 * uio is still in an inconsistent state. 1091 * 1092 * Cache a copy of the original uio, which is advanced to the redo 1093 * point using UIO_NOCOPY below. 1094 */ 1095 uio_clone = cloneuio(uio); 1096 resid = uio->uio_resid; 1097 1098 short_uio.uio_segflg = UIO_USERSPACE; 1099 short_uio.uio_rw = uio->uio_rw; 1100 short_uio.uio_td = uio->uio_td; 1101 1102 error = vn_io_fault_doio(args, uio, td); 1103 if (error != EFAULT) 1104 goto out; 1105 1106 atomic_add_long(&vn_io_faults_cnt, 1); 1107 uio_clone->uio_segflg = UIO_NOCOPY; 1108 uiomove(NULL, resid - uio->uio_resid, uio_clone); 1109 uio_clone->uio_segflg = uio->uio_segflg; 1110 1111 saveheld = curthread_pflags_set(TDP_UIOHELD); 1112 prev_td_ma = td->td_ma; 1113 prev_td_ma_cnt = td->td_ma_cnt; 1114 1115 while (uio_clone->uio_resid != 0) { 1116 len = uio_clone->uio_iov->iov_len; 1117 if (len == 0) { 1118 KASSERT(uio_clone->uio_iovcnt >= 1, 1119 ("iovcnt underflow")); 1120 uio_clone->uio_iov++; 1121 uio_clone->uio_iovcnt--; 1122 continue; 1123 } 1124 if (len > io_hold_cnt * PAGE_SIZE) 1125 len = io_hold_cnt * PAGE_SIZE; 1126 addr = (uintptr_t)uio_clone->uio_iov->iov_base; 1127 end = round_page(addr + len); 1128 if (end < addr) { 1129 error = EFAULT; 1130 break; 1131 } 1132 cnt = atop(end - trunc_page(addr)); 1133 /* 1134 * A perfectly misaligned address and length could cause 1135 * both the start and the end of the chunk to use partial 1136 * page. +2 accounts for such a situation. 1137 */ 1138 cnt = vm_fault_quick_hold_pages(&td->td_proc->p_vmspace->vm_map, 1139 addr, len, prot, ma, io_hold_cnt + 2); 1140 if (cnt == -1) { 1141 error = EFAULT; 1142 break; 1143 } 1144 short_uio.uio_iov = &short_iovec[0]; 1145 short_iovec[0].iov_base = (void *)addr; 1146 short_uio.uio_iovcnt = 1; 1147 short_uio.uio_resid = short_iovec[0].iov_len = len; 1148 short_uio.uio_offset = uio_clone->uio_offset; 1149 td->td_ma = ma; 1150 td->td_ma_cnt = cnt; 1151 1152 error = vn_io_fault_doio(args, &short_uio, td); 1153 vm_page_unhold_pages(ma, cnt); 1154 adv = len - short_uio.uio_resid; 1155 1156 uio_clone->uio_iov->iov_base = 1157 (char *)uio_clone->uio_iov->iov_base + adv; 1158 uio_clone->uio_iov->iov_len -= adv; 1159 uio_clone->uio_resid -= adv; 1160 uio_clone->uio_offset += adv; 1161 1162 uio->uio_resid -= adv; 1163 uio->uio_offset += adv; 1164 1165 if (error != 0 || adv == 0) 1166 break; 1167 } 1168 td->td_ma = prev_td_ma; 1169 td->td_ma_cnt = prev_td_ma_cnt; 1170 curthread_pflags_restore(saveheld); 1171 out: 1172 free(uio_clone, M_IOV); 1173 return (error); 1174 } 1175 1176 static int 1177 vn_io_fault(struct file *fp, struct uio *uio, struct ucred *active_cred, 1178 int flags, struct thread *td) 1179 { 1180 fo_rdwr_t *doio; 1181 struct vnode *vp; 1182 void *rl_cookie; 1183 struct vn_io_fault_args args; 1184 int error; 1185 1186 doio = uio->uio_rw == UIO_READ ? vn_read : vn_write; 1187 vp = fp->f_vnode; 1188 1189 /* 1190 * The ability to read(2) on a directory has historically been 1191 * allowed for all users, but this can and has been the source of 1192 * at least one security issue in the past. As such, it is now hidden 1193 * away behind a sysctl for those that actually need it to use it. 1194 */ 1195 if (vp->v_type == VDIR) { 1196 KASSERT(uio->uio_rw == UIO_READ, 1197 ("illegal write attempted on a directory")); 1198 if (!vfs_allow_read_dir) 1199 return (EISDIR); 1200 } 1201 1202 foffset_lock_uio(fp, uio, flags); 1203 if (do_vn_io_fault(vp, uio)) { 1204 args.kind = VN_IO_FAULT_FOP; 1205 args.args.fop_args.fp = fp; 1206 args.args.fop_args.doio = doio; 1207 args.cred = active_cred; 1208 args.flags = flags | FOF_OFFSET; 1209 if (uio->uio_rw == UIO_READ) { 1210 rl_cookie = vn_rangelock_rlock(vp, uio->uio_offset, 1211 uio->uio_offset + uio->uio_resid); 1212 } else if ((fp->f_flag & O_APPEND) != 0 || 1213 (flags & FOF_OFFSET) == 0) { 1214 /* For appenders, punt and lock the whole range. */ 1215 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 1216 } else { 1217 rl_cookie = vn_rangelock_wlock(vp, uio->uio_offset, 1218 uio->uio_offset + uio->uio_resid); 1219 } 1220 error = vn_io_fault1(vp, uio, &args, td); 1221 vn_rangelock_unlock(vp, rl_cookie); 1222 } else { 1223 error = doio(fp, uio, active_cred, flags | FOF_OFFSET, td); 1224 } 1225 foffset_unlock_uio(fp, uio, flags); 1226 return (error); 1227 } 1228 1229 /* 1230 * Helper function to perform the requested uiomove operation using 1231 * the held pages for io->uio_iov[0].iov_base buffer instead of 1232 * copyin/copyout. Access to the pages with uiomove_fromphys() 1233 * instead of iov_base prevents page faults that could occur due to 1234 * pmap_collect() invalidating the mapping created by 1235 * vm_fault_quick_hold_pages(), or pageout daemon, page laundry or 1236 * object cleanup revoking the write access from page mappings. 1237 * 1238 * Filesystems specified MNTK_NO_IOPF shall use vn_io_fault_uiomove() 1239 * instead of plain uiomove(). 1240 */ 1241 int 1242 vn_io_fault_uiomove(char *data, int xfersize, struct uio *uio) 1243 { 1244 struct uio transp_uio; 1245 struct iovec transp_iov[1]; 1246 struct thread *td; 1247 size_t adv; 1248 int error, pgadv; 1249 1250 td = curthread; 1251 if ((td->td_pflags & TDP_UIOHELD) == 0 || 1252 uio->uio_segflg != UIO_USERSPACE) 1253 return (uiomove(data, xfersize, uio)); 1254 1255 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt)); 1256 transp_iov[0].iov_base = data; 1257 transp_uio.uio_iov = &transp_iov[0]; 1258 transp_uio.uio_iovcnt = 1; 1259 if (xfersize > uio->uio_resid) 1260 xfersize = uio->uio_resid; 1261 transp_uio.uio_resid = transp_iov[0].iov_len = xfersize; 1262 transp_uio.uio_offset = 0; 1263 transp_uio.uio_segflg = UIO_SYSSPACE; 1264 /* 1265 * Since transp_iov points to data, and td_ma page array 1266 * corresponds to original uio->uio_iov, we need to invert the 1267 * direction of the i/o operation as passed to 1268 * uiomove_fromphys(). 1269 */ 1270 switch (uio->uio_rw) { 1271 case UIO_WRITE: 1272 transp_uio.uio_rw = UIO_READ; 1273 break; 1274 case UIO_READ: 1275 transp_uio.uio_rw = UIO_WRITE; 1276 break; 1277 } 1278 transp_uio.uio_td = uio->uio_td; 1279 error = uiomove_fromphys(td->td_ma, 1280 ((vm_offset_t)uio->uio_iov->iov_base) & PAGE_MASK, 1281 xfersize, &transp_uio); 1282 adv = xfersize - transp_uio.uio_resid; 1283 pgadv = 1284 (((vm_offset_t)uio->uio_iov->iov_base + adv) >> PAGE_SHIFT) - 1285 (((vm_offset_t)uio->uio_iov->iov_base) >> PAGE_SHIFT); 1286 td->td_ma += pgadv; 1287 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt, 1288 pgadv)); 1289 td->td_ma_cnt -= pgadv; 1290 uio->uio_iov->iov_base = (char *)uio->uio_iov->iov_base + adv; 1291 uio->uio_iov->iov_len -= adv; 1292 uio->uio_resid -= adv; 1293 uio->uio_offset += adv; 1294 return (error); 1295 } 1296 1297 int 1298 vn_io_fault_pgmove(vm_page_t ma[], vm_offset_t offset, int xfersize, 1299 struct uio *uio) 1300 { 1301 struct thread *td; 1302 vm_offset_t iov_base; 1303 int cnt, pgadv; 1304 1305 td = curthread; 1306 if ((td->td_pflags & TDP_UIOHELD) == 0 || 1307 uio->uio_segflg != UIO_USERSPACE) 1308 return (uiomove_fromphys(ma, offset, xfersize, uio)); 1309 1310 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt)); 1311 cnt = xfersize > uio->uio_resid ? uio->uio_resid : xfersize; 1312 iov_base = (vm_offset_t)uio->uio_iov->iov_base; 1313 switch (uio->uio_rw) { 1314 case UIO_WRITE: 1315 pmap_copy_pages(td->td_ma, iov_base & PAGE_MASK, ma, 1316 offset, cnt); 1317 break; 1318 case UIO_READ: 1319 pmap_copy_pages(ma, offset, td->td_ma, iov_base & PAGE_MASK, 1320 cnt); 1321 break; 1322 } 1323 pgadv = ((iov_base + cnt) >> PAGE_SHIFT) - (iov_base >> PAGE_SHIFT); 1324 td->td_ma += pgadv; 1325 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt, 1326 pgadv)); 1327 td->td_ma_cnt -= pgadv; 1328 uio->uio_iov->iov_base = (char *)(iov_base + cnt); 1329 uio->uio_iov->iov_len -= cnt; 1330 uio->uio_resid -= cnt; 1331 uio->uio_offset += cnt; 1332 return (0); 1333 } 1334 1335 1336 /* 1337 * File table truncate routine. 1338 */ 1339 static int 1340 vn_truncate(struct file *fp, off_t length, struct ucred *active_cred, 1341 struct thread *td) 1342 { 1343 struct vattr vattr; 1344 struct mount *mp; 1345 struct vnode *vp; 1346 void *rl_cookie; 1347 int error; 1348 1349 vp = fp->f_vnode; 1350 1351 /* 1352 * Lock the whole range for truncation. Otherwise split i/o 1353 * might happen partly before and partly after the truncation. 1354 */ 1355 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 1356 error = vn_start_write(vp, &mp, V_WAIT | PCATCH); 1357 if (error) 1358 goto out1; 1359 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1360 AUDIT_ARG_VNODE1(vp); 1361 if (vp->v_type == VDIR) { 1362 error = EISDIR; 1363 goto out; 1364 } 1365 #ifdef MAC 1366 error = mac_vnode_check_write(active_cred, fp->f_cred, vp); 1367 if (error) 1368 goto out; 1369 #endif 1370 error = VOP_ADD_WRITECOUNT(vp, 1); 1371 if (error == 0) { 1372 VATTR_NULL(&vattr); 1373 vattr.va_size = length; 1374 if ((fp->f_flag & O_FSYNC) != 0) 1375 vattr.va_vaflags |= VA_SYNC; 1376 error = VOP_SETATTR(vp, &vattr, fp->f_cred); 1377 VOP_ADD_WRITECOUNT_CHECKED(vp, -1); 1378 } 1379 out: 1380 VOP_UNLOCK(vp, 0); 1381 vn_finished_write(mp); 1382 out1: 1383 vn_rangelock_unlock(vp, rl_cookie); 1384 return (error); 1385 } 1386 1387 /* 1388 * File table vnode stat routine. 1389 */ 1390 static int 1391 vn_statfile(struct file *fp, struct stat *sb, struct ucred *active_cred, 1392 struct thread *td) 1393 { 1394 struct vnode *vp = fp->f_vnode; 1395 int error; 1396 1397 vn_lock(vp, LK_SHARED | LK_RETRY); 1398 error = vn_stat(vp, sb, active_cred, fp->f_cred, td); 1399 VOP_UNLOCK(vp, 0); 1400 1401 return (error); 1402 } 1403 1404 /* 1405 * Stat a vnode; implementation for the stat syscall 1406 */ 1407 int 1408 vn_stat(struct vnode *vp, struct stat *sb, struct ucred *active_cred, 1409 struct ucred *file_cred, struct thread *td) 1410 { 1411 struct vattr vattr; 1412 struct vattr *vap; 1413 int error; 1414 u_short mode; 1415 1416 AUDIT_ARG_VNODE1(vp); 1417 #ifdef MAC 1418 error = mac_vnode_check_stat(active_cred, file_cred, vp); 1419 if (error) 1420 return (error); 1421 #endif 1422 1423 vap = &vattr; 1424 1425 /* 1426 * Initialize defaults for new and unusual fields, so that file 1427 * systems which don't support these fields don't need to know 1428 * about them. 1429 */ 1430 vap->va_birthtime.tv_sec = -1; 1431 vap->va_birthtime.tv_nsec = 0; 1432 vap->va_fsid = VNOVAL; 1433 vap->va_rdev = NODEV; 1434 1435 error = VOP_GETATTR(vp, vap, active_cred); 1436 if (error) 1437 return (error); 1438 1439 /* 1440 * Zero the spare stat fields 1441 */ 1442 bzero(sb, sizeof *sb); 1443 1444 /* 1445 * Copy from vattr table 1446 */ 1447 if (vap->va_fsid != VNOVAL) 1448 sb->st_dev = vap->va_fsid; 1449 else 1450 sb->st_dev = vp->v_mount->mnt_stat.f_fsid.val[0]; 1451 sb->st_ino = vap->va_fileid; 1452 mode = vap->va_mode; 1453 switch (vap->va_type) { 1454 case VREG: 1455 mode |= S_IFREG; 1456 break; 1457 case VDIR: 1458 mode |= S_IFDIR; 1459 break; 1460 case VBLK: 1461 mode |= S_IFBLK; 1462 break; 1463 case VCHR: 1464 mode |= S_IFCHR; 1465 break; 1466 case VLNK: 1467 mode |= S_IFLNK; 1468 break; 1469 case VSOCK: 1470 mode |= S_IFSOCK; 1471 break; 1472 case VFIFO: 1473 mode |= S_IFIFO; 1474 break; 1475 default: 1476 return (EBADF); 1477 } 1478 sb->st_mode = mode; 1479 sb->st_nlink = vap->va_nlink; 1480 sb->st_uid = vap->va_uid; 1481 sb->st_gid = vap->va_gid; 1482 sb->st_rdev = vap->va_rdev; 1483 if (vap->va_size > OFF_MAX) 1484 return (EOVERFLOW); 1485 sb->st_size = vap->va_size; 1486 sb->st_atim = vap->va_atime; 1487 sb->st_mtim = vap->va_mtime; 1488 sb->st_ctim = vap->va_ctime; 1489 sb->st_birthtim = vap->va_birthtime; 1490 1491 /* 1492 * According to www.opengroup.org, the meaning of st_blksize is 1493 * "a filesystem-specific preferred I/O block size for this 1494 * object. In some filesystem types, this may vary from file 1495 * to file" 1496 * Use minimum/default of PAGE_SIZE (e.g. for VCHR). 1497 */ 1498 1499 sb->st_blksize = max(PAGE_SIZE, vap->va_blocksize); 1500 1501 sb->st_flags = vap->va_flags; 1502 if (priv_check(td, PRIV_VFS_GENERATION)) 1503 sb->st_gen = 0; 1504 else 1505 sb->st_gen = vap->va_gen; 1506 1507 sb->st_blocks = vap->va_bytes / S_BLKSIZE; 1508 return (0); 1509 } 1510 1511 /* 1512 * File table vnode ioctl routine. 1513 */ 1514 static int 1515 vn_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 1516 struct thread *td) 1517 { 1518 struct vattr vattr; 1519 struct vnode *vp; 1520 struct fiobmap2_arg *bmarg; 1521 int error; 1522 1523 vp = fp->f_vnode; 1524 switch (vp->v_type) { 1525 case VDIR: 1526 case VREG: 1527 switch (com) { 1528 case FIONREAD: 1529 vn_lock(vp, LK_SHARED | LK_RETRY); 1530 error = VOP_GETATTR(vp, &vattr, active_cred); 1531 VOP_UNLOCK(vp, 0); 1532 if (error == 0) 1533 *(int *)data = vattr.va_size - fp->f_offset; 1534 return (error); 1535 case FIOBMAP2: 1536 bmarg = (struct fiobmap2_arg *)data; 1537 vn_lock(vp, LK_SHARED | LK_RETRY); 1538 #ifdef MAC 1539 error = mac_vnode_check_read(active_cred, fp->f_cred, 1540 vp); 1541 if (error == 0) 1542 #endif 1543 error = VOP_BMAP(vp, bmarg->bn, NULL, 1544 &bmarg->bn, &bmarg->runp, &bmarg->runb); 1545 VOP_UNLOCK(vp, 0); 1546 return (error); 1547 case FIONBIO: 1548 case FIOASYNC: 1549 return (0); 1550 default: 1551 return (VOP_IOCTL(vp, com, data, fp->f_flag, 1552 active_cred, td)); 1553 } 1554 break; 1555 case VCHR: 1556 return (VOP_IOCTL(vp, com, data, fp->f_flag, 1557 active_cred, td)); 1558 default: 1559 return (ENOTTY); 1560 } 1561 } 1562 1563 /* 1564 * File table vnode poll routine. 1565 */ 1566 static int 1567 vn_poll(struct file *fp, int events, struct ucred *active_cred, 1568 struct thread *td) 1569 { 1570 struct vnode *vp; 1571 int error; 1572 1573 vp = fp->f_vnode; 1574 #ifdef MAC 1575 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1576 AUDIT_ARG_VNODE1(vp); 1577 error = mac_vnode_check_poll(active_cred, fp->f_cred, vp); 1578 VOP_UNLOCK(vp, 0); 1579 if (!error) 1580 #endif 1581 1582 error = VOP_POLL(vp, events, fp->f_cred, td); 1583 return (error); 1584 } 1585 1586 /* 1587 * Acquire the requested lock and then check for validity. LK_RETRY 1588 * permits vn_lock to return doomed vnodes. 1589 */ 1590 int 1591 _vn_lock(struct vnode *vp, int flags, char *file, int line) 1592 { 1593 int error; 1594 1595 VNASSERT((flags & LK_TYPE_MASK) != 0, vp, 1596 ("vn_lock: no locktype")); 1597 VNASSERT(vp->v_holdcnt != 0, vp, ("vn_lock: zero hold count")); 1598 retry: 1599 error = VOP_LOCK1(vp, flags, file, line); 1600 flags &= ~LK_INTERLOCK; /* Interlock is always dropped. */ 1601 KASSERT((flags & LK_RETRY) == 0 || error == 0, 1602 ("vn_lock: error %d incompatible with flags %#x", error, flags)); 1603 1604 if ((flags & LK_RETRY) == 0) { 1605 if (error == 0 && (vp->v_iflag & VI_DOOMED) != 0) { 1606 VOP_UNLOCK(vp, 0); 1607 error = ENOENT; 1608 } 1609 } else if (error != 0) 1610 goto retry; 1611 return (error); 1612 } 1613 1614 /* 1615 * File table vnode close routine. 1616 */ 1617 static int 1618 vn_closefile(struct file *fp, struct thread *td) 1619 { 1620 struct vnode *vp; 1621 struct flock lf; 1622 int error; 1623 bool ref; 1624 1625 vp = fp->f_vnode; 1626 fp->f_ops = &badfileops; 1627 ref = (fp->f_flag & FHASLOCK) != 0 && fp->f_type == DTYPE_VNODE; 1628 1629 error = vn_close1(vp, fp->f_flag, fp->f_cred, td, ref); 1630 1631 if (__predict_false(ref)) { 1632 lf.l_whence = SEEK_SET; 1633 lf.l_start = 0; 1634 lf.l_len = 0; 1635 lf.l_type = F_UNLCK; 1636 (void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, F_FLOCK); 1637 vrele(vp); 1638 } 1639 return (error); 1640 } 1641 1642 static bool 1643 vn_suspendable(struct mount *mp) 1644 { 1645 1646 return (mp->mnt_op->vfs_susp_clean != NULL); 1647 } 1648 1649 /* 1650 * Preparing to start a filesystem write operation. If the operation is 1651 * permitted, then we bump the count of operations in progress and 1652 * proceed. If a suspend request is in progress, we wait until the 1653 * suspension is over, and then proceed. 1654 */ 1655 static int 1656 vn_start_write_locked(struct mount *mp, int flags) 1657 { 1658 int error, mflags; 1659 1660 mtx_assert(MNT_MTX(mp), MA_OWNED); 1661 error = 0; 1662 1663 /* 1664 * Check on status of suspension. 1665 */ 1666 if ((curthread->td_pflags & TDP_IGNSUSP) == 0 || 1667 mp->mnt_susp_owner != curthread) { 1668 mflags = ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0 ? 1669 (flags & PCATCH) : 0) | (PUSER - 1); 1670 while ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { 1671 if (flags & V_NOWAIT) { 1672 error = EWOULDBLOCK; 1673 goto unlock; 1674 } 1675 error = msleep(&mp->mnt_flag, MNT_MTX(mp), mflags, 1676 "suspfs", 0); 1677 if (error) 1678 goto unlock; 1679 } 1680 } 1681 if (flags & V_XSLEEP) 1682 goto unlock; 1683 mp->mnt_writeopcount++; 1684 unlock: 1685 if (error != 0 || (flags & V_XSLEEP) != 0) 1686 MNT_REL(mp); 1687 MNT_IUNLOCK(mp); 1688 return (error); 1689 } 1690 1691 int 1692 vn_start_write(struct vnode *vp, struct mount **mpp, int flags) 1693 { 1694 struct mount *mp; 1695 int error; 1696 1697 KASSERT((flags & V_MNTREF) == 0 || (*mpp != NULL && vp == NULL), 1698 ("V_MNTREF requires mp")); 1699 1700 error = 0; 1701 /* 1702 * If a vnode is provided, get and return the mount point that 1703 * to which it will write. 1704 */ 1705 if (vp != NULL) { 1706 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) { 1707 *mpp = NULL; 1708 if (error != EOPNOTSUPP) 1709 return (error); 1710 return (0); 1711 } 1712 } 1713 if ((mp = *mpp) == NULL) 1714 return (0); 1715 1716 if (!vn_suspendable(mp)) { 1717 if (vp != NULL || (flags & V_MNTREF) != 0) 1718 vfs_rel(mp); 1719 return (0); 1720 } 1721 1722 /* 1723 * VOP_GETWRITEMOUNT() returns with the mp refcount held through 1724 * a vfs_ref(). 1725 * As long as a vnode is not provided we need to acquire a 1726 * refcount for the provided mountpoint too, in order to 1727 * emulate a vfs_ref(). 1728 */ 1729 MNT_ILOCK(mp); 1730 if (vp == NULL && (flags & V_MNTREF) == 0) 1731 MNT_REF(mp); 1732 1733 return (vn_start_write_locked(mp, flags)); 1734 } 1735 1736 /* 1737 * Secondary suspension. Used by operations such as vop_inactive 1738 * routines that are needed by the higher level functions. These 1739 * are allowed to proceed until all the higher level functions have 1740 * completed (indicated by mnt_writeopcount dropping to zero). At that 1741 * time, these operations are halted until the suspension is over. 1742 */ 1743 int 1744 vn_start_secondary_write(struct vnode *vp, struct mount **mpp, int flags) 1745 { 1746 struct mount *mp; 1747 int error; 1748 1749 KASSERT((flags & V_MNTREF) == 0 || (*mpp != NULL && vp == NULL), 1750 ("V_MNTREF requires mp")); 1751 1752 retry: 1753 if (vp != NULL) { 1754 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) { 1755 *mpp = NULL; 1756 if (error != EOPNOTSUPP) 1757 return (error); 1758 return (0); 1759 } 1760 } 1761 /* 1762 * If we are not suspended or have not yet reached suspended 1763 * mode, then let the operation proceed. 1764 */ 1765 if ((mp = *mpp) == NULL) 1766 return (0); 1767 1768 if (!vn_suspendable(mp)) { 1769 if (vp != NULL || (flags & V_MNTREF) != 0) 1770 vfs_rel(mp); 1771 return (0); 1772 } 1773 1774 /* 1775 * VOP_GETWRITEMOUNT() returns with the mp refcount held through 1776 * a vfs_ref(). 1777 * As long as a vnode is not provided we need to acquire a 1778 * refcount for the provided mountpoint too, in order to 1779 * emulate a vfs_ref(). 1780 */ 1781 MNT_ILOCK(mp); 1782 if (vp == NULL && (flags & V_MNTREF) == 0) 1783 MNT_REF(mp); 1784 if ((mp->mnt_kern_flag & (MNTK_SUSPENDED | MNTK_SUSPEND2)) == 0) { 1785 mp->mnt_secondary_writes++; 1786 mp->mnt_secondary_accwrites++; 1787 MNT_IUNLOCK(mp); 1788 return (0); 1789 } 1790 if (flags & V_NOWAIT) { 1791 MNT_REL(mp); 1792 MNT_IUNLOCK(mp); 1793 return (EWOULDBLOCK); 1794 } 1795 /* 1796 * Wait for the suspension to finish. 1797 */ 1798 error = msleep(&mp->mnt_flag, MNT_MTX(mp), (PUSER - 1) | PDROP | 1799 ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0 ? (flags & PCATCH) : 0), 1800 "suspfs", 0); 1801 vfs_rel(mp); 1802 if (error == 0) 1803 goto retry; 1804 return (error); 1805 } 1806 1807 /* 1808 * Filesystem write operation has completed. If we are suspending and this 1809 * operation is the last one, notify the suspender that the suspension is 1810 * now in effect. 1811 */ 1812 void 1813 vn_finished_write(struct mount *mp) 1814 { 1815 if (mp == NULL || !vn_suspendable(mp)) 1816 return; 1817 MNT_ILOCK(mp); 1818 MNT_REL(mp); 1819 mp->mnt_writeopcount--; 1820 if (mp->mnt_writeopcount < 0) 1821 panic("vn_finished_write: neg cnt"); 1822 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && 1823 mp->mnt_writeopcount <= 0) 1824 wakeup(&mp->mnt_writeopcount); 1825 MNT_IUNLOCK(mp); 1826 } 1827 1828 1829 /* 1830 * Filesystem secondary write operation has completed. If we are 1831 * suspending and this operation is the last one, notify the suspender 1832 * that the suspension is now in effect. 1833 */ 1834 void 1835 vn_finished_secondary_write(struct mount *mp) 1836 { 1837 if (mp == NULL || !vn_suspendable(mp)) 1838 return; 1839 MNT_ILOCK(mp); 1840 MNT_REL(mp); 1841 mp->mnt_secondary_writes--; 1842 if (mp->mnt_secondary_writes < 0) 1843 panic("vn_finished_secondary_write: neg cnt"); 1844 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && 1845 mp->mnt_secondary_writes <= 0) 1846 wakeup(&mp->mnt_secondary_writes); 1847 MNT_IUNLOCK(mp); 1848 } 1849 1850 1851 1852 /* 1853 * Request a filesystem to suspend write operations. 1854 */ 1855 int 1856 vfs_write_suspend(struct mount *mp, int flags) 1857 { 1858 int error; 1859 1860 MPASS(vn_suspendable(mp)); 1861 1862 MNT_ILOCK(mp); 1863 if (mp->mnt_susp_owner == curthread) { 1864 MNT_IUNLOCK(mp); 1865 return (EALREADY); 1866 } 1867 while (mp->mnt_kern_flag & MNTK_SUSPEND) 1868 msleep(&mp->mnt_flag, MNT_MTX(mp), PUSER - 1, "wsuspfs", 0); 1869 1870 /* 1871 * Unmount holds a write reference on the mount point. If we 1872 * own busy reference and drain for writers, we deadlock with 1873 * the reference draining in the unmount path. Callers of 1874 * vfs_write_suspend() must specify VS_SKIP_UNMOUNT if 1875 * vfs_busy() reference is owned and caller is not in the 1876 * unmount context. 1877 */ 1878 if ((flags & VS_SKIP_UNMOUNT) != 0 && 1879 (mp->mnt_kern_flag & MNTK_UNMOUNT) != 0) { 1880 MNT_IUNLOCK(mp); 1881 return (EBUSY); 1882 } 1883 1884 mp->mnt_kern_flag |= MNTK_SUSPEND; 1885 mp->mnt_susp_owner = curthread; 1886 if (mp->mnt_writeopcount > 0) 1887 (void) msleep(&mp->mnt_writeopcount, 1888 MNT_MTX(mp), (PUSER - 1)|PDROP, "suspwt", 0); 1889 else 1890 MNT_IUNLOCK(mp); 1891 if ((error = VFS_SYNC(mp, MNT_SUSPEND)) != 0) 1892 vfs_write_resume(mp, 0); 1893 return (error); 1894 } 1895 1896 /* 1897 * Request a filesystem to resume write operations. 1898 */ 1899 void 1900 vfs_write_resume(struct mount *mp, int flags) 1901 { 1902 1903 MPASS(vn_suspendable(mp)); 1904 1905 MNT_ILOCK(mp); 1906 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { 1907 KASSERT(mp->mnt_susp_owner == curthread, ("mnt_susp_owner")); 1908 mp->mnt_kern_flag &= ~(MNTK_SUSPEND | MNTK_SUSPEND2 | 1909 MNTK_SUSPENDED); 1910 mp->mnt_susp_owner = NULL; 1911 wakeup(&mp->mnt_writeopcount); 1912 wakeup(&mp->mnt_flag); 1913 curthread->td_pflags &= ~TDP_IGNSUSP; 1914 if ((flags & VR_START_WRITE) != 0) { 1915 MNT_REF(mp); 1916 mp->mnt_writeopcount++; 1917 } 1918 MNT_IUNLOCK(mp); 1919 if ((flags & VR_NO_SUSPCLR) == 0) 1920 VFS_SUSP_CLEAN(mp); 1921 } else if ((flags & VR_START_WRITE) != 0) { 1922 MNT_REF(mp); 1923 vn_start_write_locked(mp, 0); 1924 } else { 1925 MNT_IUNLOCK(mp); 1926 } 1927 } 1928 1929 /* 1930 * Helper loop around vfs_write_suspend() for filesystem unmount VFS 1931 * methods. 1932 */ 1933 int 1934 vfs_write_suspend_umnt(struct mount *mp) 1935 { 1936 int error; 1937 1938 MPASS(vn_suspendable(mp)); 1939 KASSERT((curthread->td_pflags & TDP_IGNSUSP) == 0, 1940 ("vfs_write_suspend_umnt: recursed")); 1941 1942 /* dounmount() already called vn_start_write(). */ 1943 for (;;) { 1944 vn_finished_write(mp); 1945 error = vfs_write_suspend(mp, 0); 1946 if (error != 0) { 1947 vn_start_write(NULL, &mp, V_WAIT); 1948 return (error); 1949 } 1950 MNT_ILOCK(mp); 1951 if ((mp->mnt_kern_flag & MNTK_SUSPENDED) != 0) 1952 break; 1953 MNT_IUNLOCK(mp); 1954 vn_start_write(NULL, &mp, V_WAIT); 1955 } 1956 mp->mnt_kern_flag &= ~(MNTK_SUSPENDED | MNTK_SUSPEND2); 1957 wakeup(&mp->mnt_flag); 1958 MNT_IUNLOCK(mp); 1959 curthread->td_pflags |= TDP_IGNSUSP; 1960 return (0); 1961 } 1962 1963 /* 1964 * Implement kqueues for files by translating it to vnode operation. 1965 */ 1966 static int 1967 vn_kqfilter(struct file *fp, struct knote *kn) 1968 { 1969 1970 return (VOP_KQFILTER(fp->f_vnode, kn)); 1971 } 1972 1973 /* 1974 * Simplified in-kernel wrapper calls for extended attribute access. 1975 * Both calls pass in a NULL credential, authorizing as "kernel" access. 1976 * Set IO_NODELOCKED in ioflg if the vnode is already locked. 1977 */ 1978 int 1979 vn_extattr_get(struct vnode *vp, int ioflg, int attrnamespace, 1980 const char *attrname, int *buflen, char *buf, struct thread *td) 1981 { 1982 struct uio auio; 1983 struct iovec iov; 1984 int error; 1985 1986 iov.iov_len = *buflen; 1987 iov.iov_base = buf; 1988 1989 auio.uio_iov = &iov; 1990 auio.uio_iovcnt = 1; 1991 auio.uio_rw = UIO_READ; 1992 auio.uio_segflg = UIO_SYSSPACE; 1993 auio.uio_td = td; 1994 auio.uio_offset = 0; 1995 auio.uio_resid = *buflen; 1996 1997 if ((ioflg & IO_NODELOCKED) == 0) 1998 vn_lock(vp, LK_SHARED | LK_RETRY); 1999 2000 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 2001 2002 /* authorize attribute retrieval as kernel */ 2003 error = VOP_GETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, NULL, 2004 td); 2005 2006 if ((ioflg & IO_NODELOCKED) == 0) 2007 VOP_UNLOCK(vp, 0); 2008 2009 if (error == 0) { 2010 *buflen = *buflen - auio.uio_resid; 2011 } 2012 2013 return (error); 2014 } 2015 2016 /* 2017 * XXX failure mode if partially written? 2018 */ 2019 int 2020 vn_extattr_set(struct vnode *vp, int ioflg, int attrnamespace, 2021 const char *attrname, int buflen, char *buf, struct thread *td) 2022 { 2023 struct uio auio; 2024 struct iovec iov; 2025 struct mount *mp; 2026 int error; 2027 2028 iov.iov_len = buflen; 2029 iov.iov_base = buf; 2030 2031 auio.uio_iov = &iov; 2032 auio.uio_iovcnt = 1; 2033 auio.uio_rw = UIO_WRITE; 2034 auio.uio_segflg = UIO_SYSSPACE; 2035 auio.uio_td = td; 2036 auio.uio_offset = 0; 2037 auio.uio_resid = buflen; 2038 2039 if ((ioflg & IO_NODELOCKED) == 0) { 2040 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) 2041 return (error); 2042 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2043 } 2044 2045 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 2046 2047 /* authorize attribute setting as kernel */ 2048 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, td); 2049 2050 if ((ioflg & IO_NODELOCKED) == 0) { 2051 vn_finished_write(mp); 2052 VOP_UNLOCK(vp, 0); 2053 } 2054 2055 return (error); 2056 } 2057 2058 int 2059 vn_extattr_rm(struct vnode *vp, int ioflg, int attrnamespace, 2060 const char *attrname, struct thread *td) 2061 { 2062 struct mount *mp; 2063 int error; 2064 2065 if ((ioflg & IO_NODELOCKED) == 0) { 2066 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) 2067 return (error); 2068 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2069 } 2070 2071 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 2072 2073 /* authorize attribute removal as kernel */ 2074 error = VOP_DELETEEXTATTR(vp, attrnamespace, attrname, NULL, td); 2075 if (error == EOPNOTSUPP) 2076 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, NULL, 2077 NULL, td); 2078 2079 if ((ioflg & IO_NODELOCKED) == 0) { 2080 vn_finished_write(mp); 2081 VOP_UNLOCK(vp, 0); 2082 } 2083 2084 return (error); 2085 } 2086 2087 static int 2088 vn_get_ino_alloc_vget(struct mount *mp, void *arg, int lkflags, 2089 struct vnode **rvp) 2090 { 2091 2092 return (VFS_VGET(mp, *(ino_t *)arg, lkflags, rvp)); 2093 } 2094 2095 int 2096 vn_vget_ino(struct vnode *vp, ino_t ino, int lkflags, struct vnode **rvp) 2097 { 2098 2099 return (vn_vget_ino_gen(vp, vn_get_ino_alloc_vget, &ino, 2100 lkflags, rvp)); 2101 } 2102 2103 int 2104 vn_vget_ino_gen(struct vnode *vp, vn_get_ino_t alloc, void *alloc_arg, 2105 int lkflags, struct vnode **rvp) 2106 { 2107 struct mount *mp; 2108 int ltype, error; 2109 2110 ASSERT_VOP_LOCKED(vp, "vn_vget_ino_get"); 2111 mp = vp->v_mount; 2112 ltype = VOP_ISLOCKED(vp); 2113 KASSERT(ltype == LK_EXCLUSIVE || ltype == LK_SHARED, 2114 ("vn_vget_ino: vp not locked")); 2115 error = vfs_busy(mp, MBF_NOWAIT); 2116 if (error != 0) { 2117 vfs_ref(mp); 2118 VOP_UNLOCK(vp, 0); 2119 error = vfs_busy(mp, 0); 2120 vn_lock(vp, ltype | LK_RETRY); 2121 vfs_rel(mp); 2122 if (error != 0) 2123 return (ENOENT); 2124 if (vp->v_iflag & VI_DOOMED) { 2125 vfs_unbusy(mp); 2126 return (ENOENT); 2127 } 2128 } 2129 VOP_UNLOCK(vp, 0); 2130 error = alloc(mp, alloc_arg, lkflags, rvp); 2131 vfs_unbusy(mp); 2132 if (error != 0 || *rvp != vp) 2133 vn_lock(vp, ltype | LK_RETRY); 2134 if (vp->v_iflag & VI_DOOMED) { 2135 if (error == 0) { 2136 if (*rvp == vp) 2137 vunref(vp); 2138 else 2139 vput(*rvp); 2140 } 2141 error = ENOENT; 2142 } 2143 return (error); 2144 } 2145 2146 int 2147 vn_rlimit_fsize(const struct vnode *vp, const struct uio *uio, 2148 struct thread *td) 2149 { 2150 2151 if (vp->v_type != VREG || td == NULL) 2152 return (0); 2153 if ((uoff_t)uio->uio_offset + uio->uio_resid > 2154 lim_cur(td, RLIMIT_FSIZE)) { 2155 PROC_LOCK(td->td_proc); 2156 kern_psignal(td->td_proc, SIGXFSZ); 2157 PROC_UNLOCK(td->td_proc); 2158 return (EFBIG); 2159 } 2160 return (0); 2161 } 2162 2163 int 2164 vn_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 2165 struct thread *td) 2166 { 2167 struct vnode *vp; 2168 2169 vp = fp->f_vnode; 2170 #ifdef AUDIT 2171 vn_lock(vp, LK_SHARED | LK_RETRY); 2172 AUDIT_ARG_VNODE1(vp); 2173 VOP_UNLOCK(vp, 0); 2174 #endif 2175 return (setfmode(td, active_cred, vp, mode)); 2176 } 2177 2178 int 2179 vn_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 2180 struct thread *td) 2181 { 2182 struct vnode *vp; 2183 2184 vp = fp->f_vnode; 2185 #ifdef AUDIT 2186 vn_lock(vp, LK_SHARED | LK_RETRY); 2187 AUDIT_ARG_VNODE1(vp); 2188 VOP_UNLOCK(vp, 0); 2189 #endif 2190 return (setfown(td, active_cred, vp, uid, gid)); 2191 } 2192 2193 void 2194 vn_pages_remove(struct vnode *vp, vm_pindex_t start, vm_pindex_t end) 2195 { 2196 vm_object_t object; 2197 2198 if ((object = vp->v_object) == NULL) 2199 return; 2200 VM_OBJECT_WLOCK(object); 2201 vm_object_page_remove(object, start, end, 0); 2202 VM_OBJECT_WUNLOCK(object); 2203 } 2204 2205 int 2206 vn_bmap_seekhole(struct vnode *vp, u_long cmd, off_t *off, struct ucred *cred) 2207 { 2208 struct vattr va; 2209 daddr_t bn, bnp; 2210 uint64_t bsize; 2211 off_t noff; 2212 int error; 2213 2214 KASSERT(cmd == FIOSEEKHOLE || cmd == FIOSEEKDATA, 2215 ("Wrong command %lu", cmd)); 2216 2217 if (vn_lock(vp, LK_SHARED) != 0) 2218 return (EBADF); 2219 if (vp->v_type != VREG) { 2220 error = ENOTTY; 2221 goto unlock; 2222 } 2223 error = VOP_GETATTR(vp, &va, cred); 2224 if (error != 0) 2225 goto unlock; 2226 noff = *off; 2227 if (noff >= va.va_size) { 2228 error = ENXIO; 2229 goto unlock; 2230 } 2231 bsize = vp->v_mount->mnt_stat.f_iosize; 2232 for (bn = noff / bsize; noff < va.va_size; bn++, noff += bsize - 2233 noff % bsize) { 2234 error = VOP_BMAP(vp, bn, NULL, &bnp, NULL, NULL); 2235 if (error == EOPNOTSUPP) { 2236 error = ENOTTY; 2237 goto unlock; 2238 } 2239 if ((bnp == -1 && cmd == FIOSEEKHOLE) || 2240 (bnp != -1 && cmd == FIOSEEKDATA)) { 2241 noff = bn * bsize; 2242 if (noff < *off) 2243 noff = *off; 2244 goto unlock; 2245 } 2246 } 2247 if (noff > va.va_size) 2248 noff = va.va_size; 2249 /* noff == va.va_size. There is an implicit hole at the end of file. */ 2250 if (cmd == FIOSEEKDATA) 2251 error = ENXIO; 2252 unlock: 2253 VOP_UNLOCK(vp, 0); 2254 if (error == 0) 2255 *off = noff; 2256 return (error); 2257 } 2258 2259 int 2260 vn_seek(struct file *fp, off_t offset, int whence, struct thread *td) 2261 { 2262 struct ucred *cred; 2263 struct vnode *vp; 2264 struct vattr vattr; 2265 off_t foffset, size; 2266 int error, noneg; 2267 2268 cred = td->td_ucred; 2269 vp = fp->f_vnode; 2270 foffset = foffset_lock(fp, 0); 2271 noneg = (vp->v_type != VCHR); 2272 error = 0; 2273 switch (whence) { 2274 case L_INCR: 2275 if (noneg && 2276 (foffset < 0 || 2277 (offset > 0 && foffset > OFF_MAX - offset))) { 2278 error = EOVERFLOW; 2279 break; 2280 } 2281 offset += foffset; 2282 break; 2283 case L_XTND: 2284 vn_lock(vp, LK_SHARED | LK_RETRY); 2285 error = VOP_GETATTR(vp, &vattr, cred); 2286 VOP_UNLOCK(vp, 0); 2287 if (error) 2288 break; 2289 2290 /* 2291 * If the file references a disk device, then fetch 2292 * the media size and use that to determine the ending 2293 * offset. 2294 */ 2295 if (vattr.va_size == 0 && vp->v_type == VCHR && 2296 fo_ioctl(fp, DIOCGMEDIASIZE, &size, cred, td) == 0) 2297 vattr.va_size = size; 2298 if (noneg && 2299 (vattr.va_size > OFF_MAX || 2300 (offset > 0 && vattr.va_size > OFF_MAX - offset))) { 2301 error = EOVERFLOW; 2302 break; 2303 } 2304 offset += vattr.va_size; 2305 break; 2306 case L_SET: 2307 break; 2308 case SEEK_DATA: 2309 error = fo_ioctl(fp, FIOSEEKDATA, &offset, cred, td); 2310 break; 2311 case SEEK_HOLE: 2312 error = fo_ioctl(fp, FIOSEEKHOLE, &offset, cred, td); 2313 break; 2314 default: 2315 error = EINVAL; 2316 } 2317 if (error == 0 && noneg && offset < 0) 2318 error = EINVAL; 2319 if (error != 0) 2320 goto drop; 2321 VFS_KNOTE_UNLOCKED(vp, 0); 2322 td->td_uretoff.tdu_off = offset; 2323 drop: 2324 foffset_unlock(fp, offset, error != 0 ? FOF_NOUPDATE : 0); 2325 return (error); 2326 } 2327 2328 int 2329 vn_utimes_perm(struct vnode *vp, struct vattr *vap, struct ucred *cred, 2330 struct thread *td) 2331 { 2332 int error; 2333 2334 /* 2335 * Grant permission if the caller is the owner of the file, or 2336 * the super-user, or has ACL_WRITE_ATTRIBUTES permission on 2337 * on the file. If the time pointer is null, then write 2338 * permission on the file is also sufficient. 2339 * 2340 * From NFSv4.1, draft 21, 6.2.1.3.1, Discussion of Mask Attributes: 2341 * A user having ACL_WRITE_DATA or ACL_WRITE_ATTRIBUTES 2342 * will be allowed to set the times [..] to the current 2343 * server time. 2344 */ 2345 error = VOP_ACCESSX(vp, VWRITE_ATTRIBUTES, cred, td); 2346 if (error != 0 && (vap->va_vaflags & VA_UTIMES_NULL) != 0) 2347 error = VOP_ACCESS(vp, VWRITE, cred, td); 2348 return (error); 2349 } 2350 2351 int 2352 vn_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 2353 { 2354 struct vnode *vp; 2355 int error; 2356 2357 if (fp->f_type == DTYPE_FIFO) 2358 kif->kf_type = KF_TYPE_FIFO; 2359 else 2360 kif->kf_type = KF_TYPE_VNODE; 2361 vp = fp->f_vnode; 2362 vref(vp); 2363 FILEDESC_SUNLOCK(fdp); 2364 error = vn_fill_kinfo_vnode(vp, kif); 2365 vrele(vp); 2366 FILEDESC_SLOCK(fdp); 2367 return (error); 2368 } 2369 2370 static inline void 2371 vn_fill_junk(struct kinfo_file *kif) 2372 { 2373 size_t len, olen; 2374 2375 /* 2376 * Simulate vn_fullpath returning changing values for a given 2377 * vp during e.g. coredump. 2378 */ 2379 len = (arc4random() % (sizeof(kif->kf_path) - 2)) + 1; 2380 olen = strlen(kif->kf_path); 2381 if (len < olen) 2382 strcpy(&kif->kf_path[len - 1], "$"); 2383 else 2384 for (; olen < len; olen++) 2385 strcpy(&kif->kf_path[olen], "A"); 2386 } 2387 2388 int 2389 vn_fill_kinfo_vnode(struct vnode *vp, struct kinfo_file *kif) 2390 { 2391 struct vattr va; 2392 char *fullpath, *freepath; 2393 int error; 2394 2395 kif->kf_un.kf_file.kf_file_type = vntype_to_kinfo(vp->v_type); 2396 freepath = NULL; 2397 fullpath = "-"; 2398 error = vn_fullpath(curthread, vp, &fullpath, &freepath); 2399 if (error == 0) { 2400 strlcpy(kif->kf_path, fullpath, sizeof(kif->kf_path)); 2401 } 2402 if (freepath != NULL) 2403 free(freepath, M_TEMP); 2404 2405 KFAIL_POINT_CODE(DEBUG_FP, fill_kinfo_vnode__random_path, 2406 vn_fill_junk(kif); 2407 ); 2408 2409 /* 2410 * Retrieve vnode attributes. 2411 */ 2412 va.va_fsid = VNOVAL; 2413 va.va_rdev = NODEV; 2414 vn_lock(vp, LK_SHARED | LK_RETRY); 2415 error = VOP_GETATTR(vp, &va, curthread->td_ucred); 2416 VOP_UNLOCK(vp, 0); 2417 if (error != 0) 2418 return (error); 2419 if (va.va_fsid != VNOVAL) 2420 kif->kf_un.kf_file.kf_file_fsid = va.va_fsid; 2421 else 2422 kif->kf_un.kf_file.kf_file_fsid = 2423 vp->v_mount->mnt_stat.f_fsid.val[0]; 2424 kif->kf_un.kf_file.kf_file_fsid_freebsd11 = 2425 kif->kf_un.kf_file.kf_file_fsid; /* truncate */ 2426 kif->kf_un.kf_file.kf_file_fileid = va.va_fileid; 2427 kif->kf_un.kf_file.kf_file_mode = MAKEIMODE(va.va_type, va.va_mode); 2428 kif->kf_un.kf_file.kf_file_size = va.va_size; 2429 kif->kf_un.kf_file.kf_file_rdev = va.va_rdev; 2430 kif->kf_un.kf_file.kf_file_rdev_freebsd11 = 2431 kif->kf_un.kf_file.kf_file_rdev; /* truncate */ 2432 return (0); 2433 } 2434 2435 int 2436 vn_mmap(struct file *fp, vm_map_t map, vm_offset_t *addr, vm_size_t size, 2437 vm_prot_t prot, vm_prot_t cap_maxprot, int flags, vm_ooffset_t foff, 2438 struct thread *td) 2439 { 2440 #ifdef HWPMC_HOOKS 2441 struct pmckern_map_in pkm; 2442 #endif 2443 struct mount *mp; 2444 struct vnode *vp; 2445 vm_object_t object; 2446 vm_prot_t maxprot; 2447 boolean_t writecounted; 2448 int error; 2449 2450 #if defined(COMPAT_FREEBSD7) || defined(COMPAT_FREEBSD6) || \ 2451 defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4) 2452 /* 2453 * POSIX shared-memory objects are defined to have 2454 * kernel persistence, and are not defined to support 2455 * read(2)/write(2) -- or even open(2). Thus, we can 2456 * use MAP_ASYNC to trade on-disk coherence for speed. 2457 * The shm_open(3) library routine turns on the FPOSIXSHM 2458 * flag to request this behavior. 2459 */ 2460 if ((fp->f_flag & FPOSIXSHM) != 0) 2461 flags |= MAP_NOSYNC; 2462 #endif 2463 vp = fp->f_vnode; 2464 2465 /* 2466 * Ensure that file and memory protections are 2467 * compatible. Note that we only worry about 2468 * writability if mapping is shared; in this case, 2469 * current and max prot are dictated by the open file. 2470 * XXX use the vnode instead? Problem is: what 2471 * credentials do we use for determination? What if 2472 * proc does a setuid? 2473 */ 2474 mp = vp->v_mount; 2475 if (mp != NULL && (mp->mnt_flag & MNT_NOEXEC) != 0) { 2476 maxprot = VM_PROT_NONE; 2477 if ((prot & VM_PROT_EXECUTE) != 0) 2478 return (EACCES); 2479 } else 2480 maxprot = VM_PROT_EXECUTE; 2481 if ((fp->f_flag & FREAD) != 0) 2482 maxprot |= VM_PROT_READ; 2483 else if ((prot & VM_PROT_READ) != 0) 2484 return (EACCES); 2485 2486 /* 2487 * If we are sharing potential changes via MAP_SHARED and we 2488 * are trying to get write permission although we opened it 2489 * without asking for it, bail out. 2490 */ 2491 if ((flags & MAP_SHARED) != 0) { 2492 if ((fp->f_flag & FWRITE) != 0) 2493 maxprot |= VM_PROT_WRITE; 2494 else if ((prot & VM_PROT_WRITE) != 0) 2495 return (EACCES); 2496 } else { 2497 maxprot |= VM_PROT_WRITE; 2498 cap_maxprot |= VM_PROT_WRITE; 2499 } 2500 maxprot &= cap_maxprot; 2501 2502 /* 2503 * For regular files and shared memory, POSIX requires that 2504 * the value of foff be a legitimate offset within the data 2505 * object. In particular, negative offsets are invalid. 2506 * Blocking negative offsets and overflows here avoids 2507 * possible wraparound or user-level access into reserved 2508 * ranges of the data object later. In contrast, POSIX does 2509 * not dictate how offsets are used by device drivers, so in 2510 * the case of a device mapping a negative offset is passed 2511 * on. 2512 */ 2513 if ( 2514 #ifdef _LP64 2515 size > OFF_MAX || 2516 #endif 2517 foff < 0 || foff > OFF_MAX - size) 2518 return (EINVAL); 2519 2520 writecounted = FALSE; 2521 error = vm_mmap_vnode(td, size, prot, &maxprot, &flags, vp, 2522 &foff, &object, &writecounted); 2523 if (error != 0) 2524 return (error); 2525 error = vm_mmap_object(map, addr, size, prot, maxprot, flags, object, 2526 foff, writecounted, td); 2527 if (error != 0) { 2528 /* 2529 * If this mapping was accounted for in the vnode's 2530 * writecount, then undo that now. 2531 */ 2532 if (writecounted) 2533 vm_pager_release_writecount(object, 0, size); 2534 vm_object_deallocate(object); 2535 } 2536 #ifdef HWPMC_HOOKS 2537 /* Inform hwpmc(4) if an executable is being mapped. */ 2538 if (PMC_HOOK_INSTALLED(PMC_FN_MMAP)) { 2539 if ((prot & VM_PROT_EXECUTE) != 0 && error == 0) { 2540 pkm.pm_file = vp; 2541 pkm.pm_address = (uintptr_t) *addr; 2542 PMC_CALL_HOOK_UNLOCKED(td, PMC_FN_MMAP, (void *) &pkm); 2543 } 2544 } 2545 #endif 2546 return (error); 2547 } 2548 2549 void 2550 vn_fsid(struct vnode *vp, struct vattr *va) 2551 { 2552 fsid_t *f; 2553 2554 f = &vp->v_mount->mnt_stat.f_fsid; 2555 va->va_fsid = (uint32_t)f->val[1]; 2556 va->va_fsid <<= sizeof(f->val[1]) * NBBY; 2557 va->va_fsid += (uint32_t)f->val[0]; 2558 } 2559 2560 int 2561 vn_fsync_buf(struct vnode *vp, int waitfor) 2562 { 2563 struct buf *bp, *nbp; 2564 struct bufobj *bo; 2565 struct mount *mp; 2566 int error, maxretry; 2567 2568 error = 0; 2569 maxretry = 10000; /* large, arbitrarily chosen */ 2570 mp = NULL; 2571 if (vp->v_type == VCHR) { 2572 VI_LOCK(vp); 2573 mp = vp->v_rdev->si_mountpt; 2574 VI_UNLOCK(vp); 2575 } 2576 bo = &vp->v_bufobj; 2577 BO_LOCK(bo); 2578 loop1: 2579 /* 2580 * MARK/SCAN initialization to avoid infinite loops. 2581 */ 2582 TAILQ_FOREACH(bp, &bo->bo_dirty.bv_hd, b_bobufs) { 2583 bp->b_vflags &= ~BV_SCANNED; 2584 bp->b_error = 0; 2585 } 2586 2587 /* 2588 * Flush all dirty buffers associated with a vnode. 2589 */ 2590 loop2: 2591 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 2592 if ((bp->b_vflags & BV_SCANNED) != 0) 2593 continue; 2594 bp->b_vflags |= BV_SCANNED; 2595 if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT, NULL)) { 2596 if (waitfor != MNT_WAIT) 2597 continue; 2598 if (BUF_LOCK(bp, 2599 LK_EXCLUSIVE | LK_INTERLOCK | LK_SLEEPFAIL, 2600 BO_LOCKPTR(bo)) != 0) { 2601 BO_LOCK(bo); 2602 goto loop1; 2603 } 2604 BO_LOCK(bo); 2605 } 2606 BO_UNLOCK(bo); 2607 KASSERT(bp->b_bufobj == bo, 2608 ("bp %p wrong b_bufobj %p should be %p", 2609 bp, bp->b_bufobj, bo)); 2610 if ((bp->b_flags & B_DELWRI) == 0) 2611 panic("fsync: not dirty"); 2612 if ((vp->v_object != NULL) && (bp->b_flags & B_CLUSTEROK)) { 2613 vfs_bio_awrite(bp); 2614 } else { 2615 bremfree(bp); 2616 bawrite(bp); 2617 } 2618 if (maxretry < 1000) 2619 pause("dirty", hz < 1000 ? 1 : hz / 1000); 2620 BO_LOCK(bo); 2621 goto loop2; 2622 } 2623 2624 /* 2625 * If synchronous the caller expects us to completely resolve all 2626 * dirty buffers in the system. Wait for in-progress I/O to 2627 * complete (which could include background bitmap writes), then 2628 * retry if dirty blocks still exist. 2629 */ 2630 if (waitfor == MNT_WAIT) { 2631 bufobj_wwait(bo, 0, 0); 2632 if (bo->bo_dirty.bv_cnt > 0) { 2633 /* 2634 * If we are unable to write any of these buffers 2635 * then we fail now rather than trying endlessly 2636 * to write them out. 2637 */ 2638 TAILQ_FOREACH(bp, &bo->bo_dirty.bv_hd, b_bobufs) 2639 if ((error = bp->b_error) != 0) 2640 break; 2641 if ((mp != NULL && mp->mnt_secondary_writes > 0) || 2642 (error == 0 && --maxretry >= 0)) 2643 goto loop1; 2644 if (error == 0) 2645 error = EAGAIN; 2646 } 2647 } 2648 BO_UNLOCK(bo); 2649 if (error != 0) 2650 vn_printf(vp, "fsync: giving up on dirty (error = %d) ", error); 2651 2652 return (error); 2653 }
Cache object: 9b2cd3a53db1117202b9083e31d60f58
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