vfs_vnops.c revision 269171
1/*- 2 * Copyright (c) 1982, 1986, 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Copyright (c) 2012 Konstantin Belousov <kib@FreeBSD.org> 11 * Copyright (c) 2013, 2014 The FreeBSD Foundation 12 * 13 * Portions of this software were developed by Konstantin Belousov 14 * under sponsorship from the FreeBSD Foundation. 15 * 16 * Redistribution and use in source and binary forms, with or without 17 * modification, are permitted provided that the following conditions 18 * are met: 19 * 1. Redistributions of source code must retain the above copyright 20 * notice, this list of conditions and the following disclaimer. 21 * 2. Redistributions in binary form must reproduce the above copyright 22 * notice, this list of conditions and the following disclaimer in the 23 * documentation and/or other materials provided with the distribution. 24 * 4. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 * 40 * @(#)vfs_vnops.c 8.2 (Berkeley) 1/21/94 41 */ 42 43#include <sys/cdefs.h> 44__FBSDID("$FreeBSD: stable/10/sys/kern/vfs_vnops.c 269171 2014-07-28 01:11:29Z kib $"); 45 46#include <sys/param.h> 47#include <sys/systm.h> 48#include <sys/disk.h> 49#include <sys/fcntl.h> 50#include <sys/file.h> 51#include <sys/kdb.h> 52#include <sys/stat.h> 53#include <sys/priv.h> 54#include <sys/proc.h> 55#include <sys/limits.h> 56#include <sys/lock.h> 57#include <sys/mount.h> 58#include <sys/mutex.h> 59#include <sys/namei.h> 60#include <sys/vnode.h> 61#include <sys/bio.h> 62#include <sys/buf.h> 63#include <sys/filio.h> 64#include <sys/resourcevar.h> 65#include <sys/rwlock.h> 66#include <sys/sx.h> 67#include <sys/sysctl.h> 68#include <sys/ttycom.h> 69#include <sys/conf.h> 70#include <sys/syslog.h> 71#include <sys/unistd.h> 72 73#include <security/audit/audit.h> 74#include <security/mac/mac_framework.h> 75 76#include <vm/vm.h> 77#include <vm/vm_extern.h> 78#include <vm/pmap.h> 79#include <vm/vm_map.h> 80#include <vm/vm_object.h> 81#include <vm/vm_page.h> 82 83static fo_rdwr_t vn_read; 84static fo_rdwr_t vn_write; 85static fo_rdwr_t vn_io_fault; 86static fo_truncate_t vn_truncate; 87static fo_ioctl_t vn_ioctl; 88static fo_poll_t vn_poll; 89static fo_kqfilter_t vn_kqfilter; 90static fo_stat_t vn_statfile; 91static fo_close_t vn_closefile; 92 93struct fileops vnops = { 94 .fo_read = vn_io_fault, 95 .fo_write = vn_io_fault, 96 .fo_truncate = vn_truncate, 97 .fo_ioctl = vn_ioctl, 98 .fo_poll = vn_poll, 99 .fo_kqfilter = vn_kqfilter, 100 .fo_stat = vn_statfile, 101 .fo_close = vn_closefile, 102 .fo_chmod = vn_chmod, 103 .fo_chown = vn_chown, 104 .fo_sendfile = vn_sendfile, 105 .fo_seek = vn_seek, 106 .fo_flags = DFLAG_PASSABLE | DFLAG_SEEKABLE 107}; 108 109static const int io_hold_cnt = 16; 110static int vn_io_fault_enable = 1; 111SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_enable, CTLFLAG_RW, 112 &vn_io_fault_enable, 0, "Enable vn_io_fault lock avoidance"); 113static u_long vn_io_faults_cnt; 114SYSCTL_ULONG(_debug, OID_AUTO, vn_io_faults, CTLFLAG_RD, 115 &vn_io_faults_cnt, 0, "Count of vn_io_fault lock avoidance triggers"); 116 117/* 118 * Returns true if vn_io_fault mode of handling the i/o request should 119 * be used. 120 */ 121static bool 122do_vn_io_fault(struct vnode *vp, struct uio *uio) 123{ 124 struct mount *mp; 125 126 return (uio->uio_segflg == UIO_USERSPACE && vp->v_type == VREG && 127 (mp = vp->v_mount) != NULL && 128 (mp->mnt_kern_flag & MNTK_NO_IOPF) != 0 && vn_io_fault_enable); 129} 130 131/* 132 * Structure used to pass arguments to vn_io_fault1(), to do either 133 * file- or vnode-based I/O calls. 134 */ 135struct vn_io_fault_args { 136 enum { 137 VN_IO_FAULT_FOP, 138 VN_IO_FAULT_VOP 139 } kind; 140 struct ucred *cred; 141 int flags; 142 union { 143 struct fop_args_tag { 144 struct file *fp; 145 fo_rdwr_t *doio; 146 } fop_args; 147 struct vop_args_tag { 148 struct vnode *vp; 149 } vop_args; 150 } args; 151}; 152 153static int vn_io_fault1(struct vnode *vp, struct uio *uio, 154 struct vn_io_fault_args *args, struct thread *td); 155 156int 157vn_open(ndp, flagp, cmode, fp) 158 struct nameidata *ndp; 159 int *flagp, cmode; 160 struct file *fp; 161{ 162 struct thread *td = ndp->ni_cnd.cn_thread; 163 164 return (vn_open_cred(ndp, flagp, cmode, 0, td->td_ucred, fp)); 165} 166 167/* 168 * Common code for vnode open operations via a name lookup. 169 * Lookup the vnode and invoke VOP_CREATE if needed. 170 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine. 171 * 172 * Note that this does NOT free nameidata for the successful case, 173 * due to the NDINIT being done elsewhere. 174 */ 175int 176vn_open_cred(struct nameidata *ndp, int *flagp, int cmode, u_int vn_open_flags, 177 struct ucred *cred, struct file *fp) 178{ 179 struct vnode *vp; 180 struct mount *mp; 181 struct thread *td = ndp->ni_cnd.cn_thread; 182 struct vattr vat; 183 struct vattr *vap = &vat; 184 int fmode, error; 185 186restart: 187 fmode = *flagp; 188 if (fmode & O_CREAT) { 189 ndp->ni_cnd.cn_nameiop = CREATE; 190 ndp->ni_cnd.cn_flags = ISOPEN | LOCKPARENT | LOCKLEAF; 191 if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0) 192 ndp->ni_cnd.cn_flags |= FOLLOW; 193 if (!(vn_open_flags & VN_OPEN_NOAUDIT)) 194 ndp->ni_cnd.cn_flags |= AUDITVNODE1; 195 if (vn_open_flags & VN_OPEN_NOCAPCHECK) 196 ndp->ni_cnd.cn_flags |= NOCAPCHECK; 197 bwillwrite(); 198 if ((error = namei(ndp)) != 0) 199 return (error); 200 if (ndp->ni_vp == NULL) { 201 VATTR_NULL(vap); 202 vap->va_type = VREG; 203 vap->va_mode = cmode; 204 if (fmode & O_EXCL) 205 vap->va_vaflags |= VA_EXCLUSIVE; 206 if (vn_start_write(ndp->ni_dvp, &mp, V_NOWAIT) != 0) { 207 NDFREE(ndp, NDF_ONLY_PNBUF); 208 vput(ndp->ni_dvp); 209 if ((error = vn_start_write(NULL, &mp, 210 V_XSLEEP | PCATCH)) != 0) 211 return (error); 212 goto restart; 213 } 214#ifdef MAC 215 error = mac_vnode_check_create(cred, ndp->ni_dvp, 216 &ndp->ni_cnd, vap); 217 if (error == 0) 218#endif 219 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp, 220 &ndp->ni_cnd, vap); 221 vput(ndp->ni_dvp); 222 vn_finished_write(mp); 223 if (error) { 224 NDFREE(ndp, NDF_ONLY_PNBUF); 225 return (error); 226 } 227 fmode &= ~O_TRUNC; 228 vp = ndp->ni_vp; 229 } else { 230 if (ndp->ni_dvp == ndp->ni_vp) 231 vrele(ndp->ni_dvp); 232 else 233 vput(ndp->ni_dvp); 234 ndp->ni_dvp = NULL; 235 vp = ndp->ni_vp; 236 if (fmode & O_EXCL) { 237 error = EEXIST; 238 goto bad; 239 } 240 fmode &= ~O_CREAT; 241 } 242 } else { 243 ndp->ni_cnd.cn_nameiop = LOOKUP; 244 ndp->ni_cnd.cn_flags = ISOPEN | 245 ((fmode & O_NOFOLLOW) ? NOFOLLOW : FOLLOW) | LOCKLEAF; 246 if (!(fmode & FWRITE)) 247 ndp->ni_cnd.cn_flags |= LOCKSHARED; 248 if (!(vn_open_flags & VN_OPEN_NOAUDIT)) 249 ndp->ni_cnd.cn_flags |= AUDITVNODE1; 250 if (vn_open_flags & VN_OPEN_NOCAPCHECK) 251 ndp->ni_cnd.cn_flags |= NOCAPCHECK; 252 if ((error = namei(ndp)) != 0) 253 return (error); 254 vp = ndp->ni_vp; 255 } 256 error = vn_open_vnode(vp, fmode, cred, td, fp); 257 if (error) 258 goto bad; 259 *flagp = fmode; 260 return (0); 261bad: 262 NDFREE(ndp, NDF_ONLY_PNBUF); 263 vput(vp); 264 *flagp = fmode; 265 ndp->ni_vp = NULL; 266 return (error); 267} 268 269/* 270 * Common code for vnode open operations once a vnode is located. 271 * Check permissions, and call the VOP_OPEN routine. 272 */ 273int 274vn_open_vnode(struct vnode *vp, int fmode, struct ucred *cred, 275 struct thread *td, struct file *fp) 276{ 277 struct mount *mp; 278 accmode_t accmode; 279 struct flock lf; 280 int error, have_flock, lock_flags, type; 281 282 if (vp->v_type == VLNK) 283 return (EMLINK); 284 if (vp->v_type == VSOCK) 285 return (EOPNOTSUPP); 286 if (vp->v_type != VDIR && fmode & O_DIRECTORY) 287 return (ENOTDIR); 288 accmode = 0; 289 if (fmode & (FWRITE | O_TRUNC)) { 290 if (vp->v_type == VDIR) 291 return (EISDIR); 292 accmode |= VWRITE; 293 } 294 if (fmode & FREAD) 295 accmode |= VREAD; 296 if (fmode & FEXEC) 297 accmode |= VEXEC; 298 if ((fmode & O_APPEND) && (fmode & FWRITE)) 299 accmode |= VAPPEND; 300#ifdef MAC 301 error = mac_vnode_check_open(cred, vp, accmode); 302 if (error) 303 return (error); 304#endif 305 if ((fmode & O_CREAT) == 0) { 306 if (accmode & VWRITE) { 307 error = vn_writechk(vp); 308 if (error) 309 return (error); 310 } 311 if (accmode) { 312 error = VOP_ACCESS(vp, accmode, cred, td); 313 if (error) 314 return (error); 315 } 316 } 317 if (vp->v_type == VFIFO && VOP_ISLOCKED(vp) != LK_EXCLUSIVE) 318 vn_lock(vp, LK_UPGRADE | LK_RETRY); 319 if ((error = VOP_OPEN(vp, fmode, cred, td, fp)) != 0) 320 return (error); 321 322 if (fmode & (O_EXLOCK | O_SHLOCK)) { 323 KASSERT(fp != NULL, ("open with flock requires fp")); 324 lock_flags = VOP_ISLOCKED(vp); 325 VOP_UNLOCK(vp, 0); 326 lf.l_whence = SEEK_SET; 327 lf.l_start = 0; 328 lf.l_len = 0; 329 if (fmode & O_EXLOCK) 330 lf.l_type = F_WRLCK; 331 else 332 lf.l_type = F_RDLCK; 333 type = F_FLOCK; 334 if ((fmode & FNONBLOCK) == 0) 335 type |= F_WAIT; 336 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, type); 337 have_flock = (error == 0); 338 vn_lock(vp, lock_flags | LK_RETRY); 339 if (error == 0 && vp->v_iflag & VI_DOOMED) 340 error = ENOENT; 341 /* 342 * Another thread might have used this vnode as an 343 * executable while the vnode lock was dropped. 344 * Ensure the vnode is still able to be opened for 345 * writing after the lock has been obtained. 346 */ 347 if (error == 0 && accmode & VWRITE) 348 error = vn_writechk(vp); 349 if (error) { 350 VOP_UNLOCK(vp, 0); 351 if (have_flock) { 352 lf.l_whence = SEEK_SET; 353 lf.l_start = 0; 354 lf.l_len = 0; 355 lf.l_type = F_UNLCK; 356 (void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, 357 F_FLOCK); 358 } 359 vn_start_write(vp, &mp, V_WAIT); 360 vn_lock(vp, lock_flags | LK_RETRY); 361 (void)VOP_CLOSE(vp, fmode, cred, td); 362 vn_finished_write(mp); 363 /* Prevent second close from fdrop()->vn_close(). */ 364 if (fp != NULL) 365 fp->f_ops= &badfileops; 366 return (error); 367 } 368 fp->f_flag |= FHASLOCK; 369 } 370 if (fmode & FWRITE) { 371 VOP_ADD_WRITECOUNT(vp, 1); 372 CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d", 373 __func__, vp, vp->v_writecount); 374 } 375 ASSERT_VOP_LOCKED(vp, "vn_open_vnode"); 376 return (0); 377} 378 379/* 380 * Check for write permissions on the specified vnode. 381 * Prototype text segments cannot be written. 382 */ 383int 384vn_writechk(vp) 385 register struct vnode *vp; 386{ 387 388 ASSERT_VOP_LOCKED(vp, "vn_writechk"); 389 /* 390 * If there's shared text associated with 391 * the vnode, try to free it up once. If 392 * we fail, we can't allow writing. 393 */ 394 if (VOP_IS_TEXT(vp)) 395 return (ETXTBSY); 396 397 return (0); 398} 399 400/* 401 * Vnode close call 402 */ 403int 404vn_close(vp, flags, file_cred, td) 405 register struct vnode *vp; 406 int flags; 407 struct ucred *file_cred; 408 struct thread *td; 409{ 410 struct mount *mp; 411 int error, lock_flags; 412 413 if (vp->v_type != VFIFO && (flags & FWRITE) == 0 && 414 MNT_EXTENDED_SHARED(vp->v_mount)) 415 lock_flags = LK_SHARED; 416 else 417 lock_flags = LK_EXCLUSIVE; 418 419 vn_start_write(vp, &mp, V_WAIT); 420 vn_lock(vp, lock_flags | LK_RETRY); 421 if (flags & FWRITE) { 422 VNASSERT(vp->v_writecount > 0, vp, 423 ("vn_close: negative writecount")); 424 VOP_ADD_WRITECOUNT(vp, -1); 425 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d", 426 __func__, vp, vp->v_writecount); 427 } 428 error = VOP_CLOSE(vp, flags, file_cred, td); 429 vput(vp); 430 vn_finished_write(mp); 431 return (error); 432} 433 434/* 435 * Heuristic to detect sequential operation. 436 */ 437static int 438sequential_heuristic(struct uio *uio, struct file *fp) 439{ 440 441 if (atomic_load_acq_int(&(fp->f_flag)) & FRDAHEAD) 442 return (fp->f_seqcount << IO_SEQSHIFT); 443 444 /* 445 * Offset 0 is handled specially. open() sets f_seqcount to 1 so 446 * that the first I/O is normally considered to be slightly 447 * sequential. Seeking to offset 0 doesn't change sequentiality 448 * unless previous seeks have reduced f_seqcount to 0, in which 449 * case offset 0 is not special. 450 */ 451 if ((uio->uio_offset == 0 && fp->f_seqcount > 0) || 452 uio->uio_offset == fp->f_nextoff) { 453 /* 454 * f_seqcount is in units of fixed-size blocks so that it 455 * depends mainly on the amount of sequential I/O and not 456 * much on the number of sequential I/O's. The fixed size 457 * of 16384 is hard-coded here since it is (not quite) just 458 * a magic size that works well here. This size is more 459 * closely related to the best I/O size for real disks than 460 * to any block size used by software. 461 */ 462 fp->f_seqcount += howmany(uio->uio_resid, 16384); 463 if (fp->f_seqcount > IO_SEQMAX) 464 fp->f_seqcount = IO_SEQMAX; 465 return (fp->f_seqcount << IO_SEQSHIFT); 466 } 467 468 /* Not sequential. Quickly draw-down sequentiality. */ 469 if (fp->f_seqcount > 1) 470 fp->f_seqcount = 1; 471 else 472 fp->f_seqcount = 0; 473 return (0); 474} 475 476/* 477 * Package up an I/O request on a vnode into a uio and do it. 478 */ 479int 480vn_rdwr(enum uio_rw rw, struct vnode *vp, void *base, int len, off_t offset, 481 enum uio_seg segflg, int ioflg, struct ucred *active_cred, 482 struct ucred *file_cred, ssize_t *aresid, struct thread *td) 483{ 484 struct uio auio; 485 struct iovec aiov; 486 struct mount *mp; 487 struct ucred *cred; 488 void *rl_cookie; 489 struct vn_io_fault_args args; 490 int error, lock_flags; 491 492 auio.uio_iov = &aiov; 493 auio.uio_iovcnt = 1; 494 aiov.iov_base = base; 495 aiov.iov_len = len; 496 auio.uio_resid = len; 497 auio.uio_offset = offset; 498 auio.uio_segflg = segflg; 499 auio.uio_rw = rw; 500 auio.uio_td = td; 501 error = 0; 502 503 if ((ioflg & IO_NODELOCKED) == 0) { 504 if (rw == UIO_READ) { 505 rl_cookie = vn_rangelock_rlock(vp, offset, 506 offset + len); 507 } else { 508 rl_cookie = vn_rangelock_wlock(vp, offset, 509 offset + len); 510 } 511 mp = NULL; 512 if (rw == UIO_WRITE) { 513 if (vp->v_type != VCHR && 514 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) 515 != 0) 516 goto out; 517 if (MNT_SHARED_WRITES(mp) || 518 ((mp == NULL) && MNT_SHARED_WRITES(vp->v_mount))) 519 lock_flags = LK_SHARED; 520 else 521 lock_flags = LK_EXCLUSIVE; 522 } else 523 lock_flags = LK_SHARED; 524 vn_lock(vp, lock_flags | LK_RETRY); 525 } else 526 rl_cookie = NULL; 527 528 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 529#ifdef MAC 530 if ((ioflg & IO_NOMACCHECK) == 0) { 531 if (rw == UIO_READ) 532 error = mac_vnode_check_read(active_cred, file_cred, 533 vp); 534 else 535 error = mac_vnode_check_write(active_cred, file_cred, 536 vp); 537 } 538#endif 539 if (error == 0) { 540 if (file_cred != NULL) 541 cred = file_cred; 542 else 543 cred = active_cred; 544 if (do_vn_io_fault(vp, &auio)) { 545 args.kind = VN_IO_FAULT_VOP; 546 args.cred = cred; 547 args.flags = ioflg; 548 args.args.vop_args.vp = vp; 549 error = vn_io_fault1(vp, &auio, &args, td); 550 } else if (rw == UIO_READ) { 551 error = VOP_READ(vp, &auio, ioflg, cred); 552 } else /* if (rw == UIO_WRITE) */ { 553 error = VOP_WRITE(vp, &auio, ioflg, cred); 554 } 555 } 556 if (aresid) 557 *aresid = auio.uio_resid; 558 else 559 if (auio.uio_resid && error == 0) 560 error = EIO; 561 if ((ioflg & IO_NODELOCKED) == 0) { 562 VOP_UNLOCK(vp, 0); 563 if (mp != NULL) 564 vn_finished_write(mp); 565 } 566 out: 567 if (rl_cookie != NULL) 568 vn_rangelock_unlock(vp, rl_cookie); 569 return (error); 570} 571 572/* 573 * Package up an I/O request on a vnode into a uio and do it. The I/O 574 * request is split up into smaller chunks and we try to avoid saturating 575 * the buffer cache while potentially holding a vnode locked, so we 576 * check bwillwrite() before calling vn_rdwr(). We also call kern_yield() 577 * to give other processes a chance to lock the vnode (either other processes 578 * core'ing the same binary, or unrelated processes scanning the directory). 579 */ 580int 581vn_rdwr_inchunks(rw, vp, base, len, offset, segflg, ioflg, active_cred, 582 file_cred, aresid, td) 583 enum uio_rw rw; 584 struct vnode *vp; 585 void *base; 586 size_t len; 587 off_t offset; 588 enum uio_seg segflg; 589 int ioflg; 590 struct ucred *active_cred; 591 struct ucred *file_cred; 592 size_t *aresid; 593 struct thread *td; 594{ 595 int error = 0; 596 ssize_t iaresid; 597 598 do { 599 int chunk; 600 601 /* 602 * Force `offset' to a multiple of MAXBSIZE except possibly 603 * for the first chunk, so that filesystems only need to 604 * write full blocks except possibly for the first and last 605 * chunks. 606 */ 607 chunk = MAXBSIZE - (uoff_t)offset % MAXBSIZE; 608 609 if (chunk > len) 610 chunk = len; 611 if (rw != UIO_READ && vp->v_type == VREG) 612 bwillwrite(); 613 iaresid = 0; 614 error = vn_rdwr(rw, vp, base, chunk, offset, segflg, 615 ioflg, active_cred, file_cred, &iaresid, td); 616 len -= chunk; /* aresid calc already includes length */ 617 if (error) 618 break; 619 offset += chunk; 620 base = (char *)base + chunk; 621 kern_yield(PRI_USER); 622 } while (len); 623 if (aresid) 624 *aresid = len + iaresid; 625 return (error); 626} 627 628off_t 629foffset_lock(struct file *fp, int flags) 630{ 631 struct mtx *mtxp; 632 off_t res; 633 634 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed")); 635 636#if OFF_MAX <= LONG_MAX 637 /* 638 * Caller only wants the current f_offset value. Assume that 639 * the long and shorter integer types reads are atomic. 640 */ 641 if ((flags & FOF_NOLOCK) != 0) 642 return (fp->f_offset); 643#endif 644 645 /* 646 * According to McKusick the vn lock was protecting f_offset here. 647 * It is now protected by the FOFFSET_LOCKED flag. 648 */ 649 mtxp = mtx_pool_find(mtxpool_sleep, fp); 650 mtx_lock(mtxp); 651 if ((flags & FOF_NOLOCK) == 0) { 652 while (fp->f_vnread_flags & FOFFSET_LOCKED) { 653 fp->f_vnread_flags |= FOFFSET_LOCK_WAITING; 654 msleep(&fp->f_vnread_flags, mtxp, PUSER -1, 655 "vofflock", 0); 656 } 657 fp->f_vnread_flags |= FOFFSET_LOCKED; 658 } 659 res = fp->f_offset; 660 mtx_unlock(mtxp); 661 return (res); 662} 663 664void 665foffset_unlock(struct file *fp, off_t val, int flags) 666{ 667 struct mtx *mtxp; 668 669 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed")); 670 671#if OFF_MAX <= LONG_MAX 672 if ((flags & FOF_NOLOCK) != 0) { 673 if ((flags & FOF_NOUPDATE) == 0) 674 fp->f_offset = val; 675 if ((flags & FOF_NEXTOFF) != 0) 676 fp->f_nextoff = val; 677 return; 678 } 679#endif 680 681 mtxp = mtx_pool_find(mtxpool_sleep, fp); 682 mtx_lock(mtxp); 683 if ((flags & FOF_NOUPDATE) == 0) 684 fp->f_offset = val; 685 if ((flags & FOF_NEXTOFF) != 0) 686 fp->f_nextoff = val; 687 if ((flags & FOF_NOLOCK) == 0) { 688 KASSERT((fp->f_vnread_flags & FOFFSET_LOCKED) != 0, 689 ("Lost FOFFSET_LOCKED")); 690 if (fp->f_vnread_flags & FOFFSET_LOCK_WAITING) 691 wakeup(&fp->f_vnread_flags); 692 fp->f_vnread_flags = 0; 693 } 694 mtx_unlock(mtxp); 695} 696 697void 698foffset_lock_uio(struct file *fp, struct uio *uio, int flags) 699{ 700 701 if ((flags & FOF_OFFSET) == 0) 702 uio->uio_offset = foffset_lock(fp, flags); 703} 704 705void 706foffset_unlock_uio(struct file *fp, struct uio *uio, int flags) 707{ 708 709 if ((flags & FOF_OFFSET) == 0) 710 foffset_unlock(fp, uio->uio_offset, flags); 711} 712 713static int 714get_advice(struct file *fp, struct uio *uio) 715{ 716 struct mtx *mtxp; 717 int ret; 718 719 ret = POSIX_FADV_NORMAL; 720 if (fp->f_advice == NULL) 721 return (ret); 722 723 mtxp = mtx_pool_find(mtxpool_sleep, fp); 724 mtx_lock(mtxp); 725 if (uio->uio_offset >= fp->f_advice->fa_start && 726 uio->uio_offset + uio->uio_resid <= fp->f_advice->fa_end) 727 ret = fp->f_advice->fa_advice; 728 mtx_unlock(mtxp); 729 return (ret); 730} 731 732/* 733 * File table vnode read routine. 734 */ 735static int 736vn_read(fp, uio, active_cred, flags, td) 737 struct file *fp; 738 struct uio *uio; 739 struct ucred *active_cred; 740 int flags; 741 struct thread *td; 742{ 743 struct vnode *vp; 744 struct mtx *mtxp; 745 int error, ioflag; 746 int advice; 747 off_t offset, start, end; 748 749 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", 750 uio->uio_td, td)); 751 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET")); 752 vp = fp->f_vnode; 753 ioflag = 0; 754 if (fp->f_flag & FNONBLOCK) 755 ioflag |= IO_NDELAY; 756 if (fp->f_flag & O_DIRECT) 757 ioflag |= IO_DIRECT; 758 advice = get_advice(fp, uio); 759 vn_lock(vp, LK_SHARED | LK_RETRY); 760 761 switch (advice) { 762 case POSIX_FADV_NORMAL: 763 case POSIX_FADV_SEQUENTIAL: 764 case POSIX_FADV_NOREUSE: 765 ioflag |= sequential_heuristic(uio, fp); 766 break; 767 case POSIX_FADV_RANDOM: 768 /* Disable read-ahead for random I/O. */ 769 break; 770 } 771 offset = uio->uio_offset; 772 773#ifdef MAC 774 error = mac_vnode_check_read(active_cred, fp->f_cred, vp); 775 if (error == 0) 776#endif 777 error = VOP_READ(vp, uio, ioflag, fp->f_cred); 778 fp->f_nextoff = uio->uio_offset; 779 VOP_UNLOCK(vp, 0); 780 if (error == 0 && advice == POSIX_FADV_NOREUSE && 781 offset != uio->uio_offset) { 782 /* 783 * Use POSIX_FADV_DONTNEED to flush clean pages and 784 * buffers for the backing file after a 785 * POSIX_FADV_NOREUSE read(2). To optimize the common 786 * case of using POSIX_FADV_NOREUSE with sequential 787 * access, track the previous implicit DONTNEED 788 * request and grow this request to include the 789 * current read(2) in addition to the previous 790 * DONTNEED. With purely sequential access this will 791 * cause the DONTNEED requests to continously grow to 792 * cover all of the previously read regions of the 793 * file. This allows filesystem blocks that are 794 * accessed by multiple calls to read(2) to be flushed 795 * once the last read(2) finishes. 796 */ 797 start = offset; 798 end = uio->uio_offset - 1; 799 mtxp = mtx_pool_find(mtxpool_sleep, fp); 800 mtx_lock(mtxp); 801 if (fp->f_advice != NULL && 802 fp->f_advice->fa_advice == POSIX_FADV_NOREUSE) { 803 if (start != 0 && fp->f_advice->fa_prevend + 1 == start) 804 start = fp->f_advice->fa_prevstart; 805 else if (fp->f_advice->fa_prevstart != 0 && 806 fp->f_advice->fa_prevstart == end + 1) 807 end = fp->f_advice->fa_prevend; 808 fp->f_advice->fa_prevstart = start; 809 fp->f_advice->fa_prevend = end; 810 } 811 mtx_unlock(mtxp); 812 error = VOP_ADVISE(vp, start, end, POSIX_FADV_DONTNEED); 813 } 814 return (error); 815} 816 817/* 818 * File table vnode write routine. 819 */ 820static int 821vn_write(fp, uio, active_cred, flags, td) 822 struct file *fp; 823 struct uio *uio; 824 struct ucred *active_cred; 825 int flags; 826 struct thread *td; 827{ 828 struct vnode *vp; 829 struct mount *mp; 830 struct mtx *mtxp; 831 int error, ioflag, lock_flags; 832 int advice; 833 off_t offset, start, end; 834 835 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", 836 uio->uio_td, td)); 837 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET")); 838 vp = fp->f_vnode; 839 if (vp->v_type == VREG) 840 bwillwrite(); 841 ioflag = IO_UNIT; 842 if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) 843 ioflag |= IO_APPEND; 844 if (fp->f_flag & FNONBLOCK) 845 ioflag |= IO_NDELAY; 846 if (fp->f_flag & O_DIRECT) 847 ioflag |= IO_DIRECT; 848 if ((fp->f_flag & O_FSYNC) || 849 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS))) 850 ioflag |= IO_SYNC; 851 mp = NULL; 852 if (vp->v_type != VCHR && 853 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0) 854 goto unlock; 855 856 advice = get_advice(fp, uio); 857 858 if (MNT_SHARED_WRITES(mp) || 859 (mp == NULL && MNT_SHARED_WRITES(vp->v_mount))) { 860 lock_flags = LK_SHARED; 861 } else { 862 lock_flags = LK_EXCLUSIVE; 863 } 864 865 vn_lock(vp, lock_flags | LK_RETRY); 866 switch (advice) { 867 case POSIX_FADV_NORMAL: 868 case POSIX_FADV_SEQUENTIAL: 869 case POSIX_FADV_NOREUSE: 870 ioflag |= sequential_heuristic(uio, fp); 871 break; 872 case POSIX_FADV_RANDOM: 873 /* XXX: Is this correct? */ 874 break; 875 } 876 offset = uio->uio_offset; 877 878#ifdef MAC 879 error = mac_vnode_check_write(active_cred, fp->f_cred, vp); 880 if (error == 0) 881#endif 882 error = VOP_WRITE(vp, uio, ioflag, fp->f_cred); 883 fp->f_nextoff = uio->uio_offset; 884 VOP_UNLOCK(vp, 0); 885 if (vp->v_type != VCHR) 886 vn_finished_write(mp); 887 if (error == 0 && advice == POSIX_FADV_NOREUSE && 888 offset != uio->uio_offset) { 889 /* 890 * Use POSIX_FADV_DONTNEED to flush clean pages and 891 * buffers for the backing file after a 892 * POSIX_FADV_NOREUSE write(2). To optimize the 893 * common case of using POSIX_FADV_NOREUSE with 894 * sequential access, track the previous implicit 895 * DONTNEED request and grow this request to include 896 * the current write(2) in addition to the previous 897 * DONTNEED. With purely sequential access this will 898 * cause the DONTNEED requests to continously grow to 899 * cover all of the previously written regions of the 900 * file. 901 * 902 * Note that the blocks just written are almost 903 * certainly still dirty, so this only works when 904 * VOP_ADVISE() calls from subsequent writes push out 905 * the data written by this write(2) once the backing 906 * buffers are clean. However, as compared to forcing 907 * IO_DIRECT, this gives much saner behavior. Write 908 * clustering is still allowed, and clean pages are 909 * merely moved to the cache page queue rather than 910 * outright thrown away. This means a subsequent 911 * read(2) can still avoid hitting the disk if the 912 * pages have not been reclaimed. 913 * 914 * This does make POSIX_FADV_NOREUSE largely useless 915 * with non-sequential access. However, sequential 916 * access is the more common use case and the flag is 917 * merely advisory. 918 */ 919 start = offset; 920 end = uio->uio_offset - 1; 921 mtxp = mtx_pool_find(mtxpool_sleep, fp); 922 mtx_lock(mtxp); 923 if (fp->f_advice != NULL && 924 fp->f_advice->fa_advice == POSIX_FADV_NOREUSE) { 925 if (start != 0 && fp->f_advice->fa_prevend + 1 == start) 926 start = fp->f_advice->fa_prevstart; 927 else if (fp->f_advice->fa_prevstart != 0 && 928 fp->f_advice->fa_prevstart == end + 1) 929 end = fp->f_advice->fa_prevend; 930 fp->f_advice->fa_prevstart = start; 931 fp->f_advice->fa_prevend = end; 932 } 933 mtx_unlock(mtxp); 934 error = VOP_ADVISE(vp, start, end, POSIX_FADV_DONTNEED); 935 } 936 937unlock: 938 return (error); 939} 940 941/* 942 * The vn_io_fault() is a wrapper around vn_read() and vn_write() to 943 * prevent the following deadlock: 944 * 945 * Assume that the thread A reads from the vnode vp1 into userspace 946 * buffer buf1 backed by the pages of vnode vp2. If a page in buf1 is 947 * currently not resident, then system ends up with the call chain 948 * vn_read() -> VOP_READ(vp1) -> uiomove() -> [Page Fault] -> 949 * vm_fault(buf1) -> vnode_pager_getpages(vp2) -> VOP_GETPAGES(vp2) 950 * which establishes lock order vp1->vn_lock, then vp2->vn_lock. 951 * If, at the same time, thread B reads from vnode vp2 into buffer buf2 952 * backed by the pages of vnode vp1, and some page in buf2 is not 953 * resident, we get a reversed order vp2->vn_lock, then vp1->vn_lock. 954 * 955 * To prevent the lock order reversal and deadlock, vn_io_fault() does 956 * not allow page faults to happen during VOP_READ() or VOP_WRITE(). 957 * Instead, it first tries to do the whole range i/o with pagefaults 958 * disabled. If all pages in the i/o buffer are resident and mapped, 959 * VOP will succeed (ignoring the genuine filesystem errors). 960 * Otherwise, we get back EFAULT, and vn_io_fault() falls back to do 961 * i/o in chunks, with all pages in the chunk prefaulted and held 962 * using vm_fault_quick_hold_pages(). 963 * 964 * Filesystems using this deadlock avoidance scheme should use the 965 * array of the held pages from uio, saved in the curthread->td_ma, 966 * instead of doing uiomove(). A helper function 967 * vn_io_fault_uiomove() converts uiomove request into 968 * uiomove_fromphys() over td_ma array. 969 * 970 * Since vnode locks do not cover the whole i/o anymore, rangelocks 971 * make the current i/o request atomic with respect to other i/os and 972 * truncations. 973 */ 974 975/* 976 * Decode vn_io_fault_args and perform the corresponding i/o. 977 */ 978static int 979vn_io_fault_doio(struct vn_io_fault_args *args, struct uio *uio, 980 struct thread *td) 981{ 982 983 switch (args->kind) { 984 case VN_IO_FAULT_FOP: 985 return ((args->args.fop_args.doio)(args->args.fop_args.fp, 986 uio, args->cred, args->flags, td)); 987 case VN_IO_FAULT_VOP: 988 if (uio->uio_rw == UIO_READ) { 989 return (VOP_READ(args->args.vop_args.vp, uio, 990 args->flags, args->cred)); 991 } else if (uio->uio_rw == UIO_WRITE) { 992 return (VOP_WRITE(args->args.vop_args.vp, uio, 993 args->flags, args->cred)); 994 } 995 break; 996 } 997 panic("vn_io_fault_doio: unknown kind of io %d %d", args->kind, 998 uio->uio_rw); 999} 1000 1001/* 1002 * Common code for vn_io_fault(), agnostic to the kind of i/o request. 1003 * Uses vn_io_fault_doio() to make the call to an actual i/o function. 1004 * Used from vn_rdwr() and vn_io_fault(), which encode the i/o request 1005 * into args and call vn_io_fault1() to handle faults during the user 1006 * mode buffer accesses. 1007 */ 1008static int 1009vn_io_fault1(struct vnode *vp, struct uio *uio, struct vn_io_fault_args *args, 1010 struct thread *td) 1011{ 1012 vm_page_t ma[io_hold_cnt + 2]; 1013 struct uio *uio_clone, short_uio; 1014 struct iovec short_iovec[1]; 1015 vm_page_t *prev_td_ma; 1016 vm_prot_t prot; 1017 vm_offset_t addr, end; 1018 size_t len, resid; 1019 ssize_t adv; 1020 int error, cnt, save, saveheld, prev_td_ma_cnt; 1021 1022 prot = uio->uio_rw == UIO_READ ? VM_PROT_WRITE : VM_PROT_READ; 1023 1024 /* 1025 * The UFS follows IO_UNIT directive and replays back both 1026 * uio_offset and uio_resid if an error is encountered during the 1027 * operation. But, since the iovec may be already advanced, 1028 * uio is still in an inconsistent state. 1029 * 1030 * Cache a copy of the original uio, which is advanced to the redo 1031 * point using UIO_NOCOPY below. 1032 */ 1033 uio_clone = cloneuio(uio); 1034 resid = uio->uio_resid; 1035 1036 short_uio.uio_segflg = UIO_USERSPACE; 1037 short_uio.uio_rw = uio->uio_rw; 1038 short_uio.uio_td = uio->uio_td; 1039 1040 save = vm_fault_disable_pagefaults(); 1041 error = vn_io_fault_doio(args, uio, td); 1042 if (error != EFAULT) 1043 goto out; 1044 1045 atomic_add_long(&vn_io_faults_cnt, 1); 1046 uio_clone->uio_segflg = UIO_NOCOPY; 1047 uiomove(NULL, resid - uio->uio_resid, uio_clone); 1048 uio_clone->uio_segflg = uio->uio_segflg; 1049 1050 saveheld = curthread_pflags_set(TDP_UIOHELD); 1051 prev_td_ma = td->td_ma; 1052 prev_td_ma_cnt = td->td_ma_cnt; 1053 1054 while (uio_clone->uio_resid != 0) { 1055 len = uio_clone->uio_iov->iov_len; 1056 if (len == 0) { 1057 KASSERT(uio_clone->uio_iovcnt >= 1, 1058 ("iovcnt underflow")); 1059 uio_clone->uio_iov++; 1060 uio_clone->uio_iovcnt--; 1061 continue; 1062 } 1063 if (len > io_hold_cnt * PAGE_SIZE) 1064 len = io_hold_cnt * PAGE_SIZE; 1065 addr = (uintptr_t)uio_clone->uio_iov->iov_base; 1066 end = round_page(addr + len); 1067 if (end < addr) { 1068 error = EFAULT; 1069 break; 1070 } 1071 cnt = atop(end - trunc_page(addr)); 1072 /* 1073 * A perfectly misaligned address and length could cause 1074 * both the start and the end of the chunk to use partial 1075 * page. +2 accounts for such a situation. 1076 */ 1077 cnt = vm_fault_quick_hold_pages(&td->td_proc->p_vmspace->vm_map, 1078 addr, len, prot, ma, io_hold_cnt + 2); 1079 if (cnt == -1) { 1080 error = EFAULT; 1081 break; 1082 } 1083 short_uio.uio_iov = &short_iovec[0]; 1084 short_iovec[0].iov_base = (void *)addr; 1085 short_uio.uio_iovcnt = 1; 1086 short_uio.uio_resid = short_iovec[0].iov_len = len; 1087 short_uio.uio_offset = uio_clone->uio_offset; 1088 td->td_ma = ma; 1089 td->td_ma_cnt = cnt; 1090 1091 error = vn_io_fault_doio(args, &short_uio, td); 1092 vm_page_unhold_pages(ma, cnt); 1093 adv = len - short_uio.uio_resid; 1094 1095 uio_clone->uio_iov->iov_base = 1096 (char *)uio_clone->uio_iov->iov_base + adv; 1097 uio_clone->uio_iov->iov_len -= adv; 1098 uio_clone->uio_resid -= adv; 1099 uio_clone->uio_offset += adv; 1100 1101 uio->uio_resid -= adv; 1102 uio->uio_offset += adv; 1103 1104 if (error != 0 || adv == 0) 1105 break; 1106 } 1107 td->td_ma = prev_td_ma; 1108 td->td_ma_cnt = prev_td_ma_cnt; 1109 curthread_pflags_restore(saveheld); 1110out: 1111 vm_fault_enable_pagefaults(save); 1112 free(uio_clone, M_IOV); 1113 return (error); 1114} 1115 1116static int 1117vn_io_fault(struct file *fp, struct uio *uio, struct ucred *active_cred, 1118 int flags, struct thread *td) 1119{ 1120 fo_rdwr_t *doio; 1121 struct vnode *vp; 1122 void *rl_cookie; 1123 struct vn_io_fault_args args; 1124 int error; 1125 1126 doio = uio->uio_rw == UIO_READ ? vn_read : vn_write; 1127 vp = fp->f_vnode; 1128 foffset_lock_uio(fp, uio, flags); 1129 if (do_vn_io_fault(vp, uio)) { 1130 args.kind = VN_IO_FAULT_FOP; 1131 args.args.fop_args.fp = fp; 1132 args.args.fop_args.doio = doio; 1133 args.cred = active_cred; 1134 args.flags = flags | FOF_OFFSET; 1135 if (uio->uio_rw == UIO_READ) { 1136 rl_cookie = vn_rangelock_rlock(vp, uio->uio_offset, 1137 uio->uio_offset + uio->uio_resid); 1138 } else if ((fp->f_flag & O_APPEND) != 0 || 1139 (flags & FOF_OFFSET) == 0) { 1140 /* For appenders, punt and lock the whole range. */ 1141 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 1142 } else { 1143 rl_cookie = vn_rangelock_wlock(vp, uio->uio_offset, 1144 uio->uio_offset + uio->uio_resid); 1145 } 1146 error = vn_io_fault1(vp, uio, &args, td); 1147 vn_rangelock_unlock(vp, rl_cookie); 1148 } else { 1149 error = doio(fp, uio, active_cred, flags | FOF_OFFSET, td); 1150 } 1151 foffset_unlock_uio(fp, uio, flags); 1152 return (error); 1153} 1154 1155/* 1156 * Helper function to perform the requested uiomove operation using 1157 * the held pages for io->uio_iov[0].iov_base buffer instead of 1158 * copyin/copyout. Access to the pages with uiomove_fromphys() 1159 * instead of iov_base prevents page faults that could occur due to 1160 * pmap_collect() invalidating the mapping created by 1161 * vm_fault_quick_hold_pages(), or pageout daemon, page laundry or 1162 * object cleanup revoking the write access from page mappings. 1163 * 1164 * Filesystems specified MNTK_NO_IOPF shall use vn_io_fault_uiomove() 1165 * instead of plain uiomove(). 1166 */ 1167int 1168vn_io_fault_uiomove(char *data, int xfersize, struct uio *uio) 1169{ 1170 struct uio transp_uio; 1171 struct iovec transp_iov[1]; 1172 struct thread *td; 1173 size_t adv; 1174 int error, pgadv; 1175 1176 td = curthread; 1177 if ((td->td_pflags & TDP_UIOHELD) == 0 || 1178 uio->uio_segflg != UIO_USERSPACE) 1179 return (uiomove(data, xfersize, uio)); 1180 1181 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt)); 1182 transp_iov[0].iov_base = data; 1183 transp_uio.uio_iov = &transp_iov[0]; 1184 transp_uio.uio_iovcnt = 1; 1185 if (xfersize > uio->uio_resid) 1186 xfersize = uio->uio_resid; 1187 transp_uio.uio_resid = transp_iov[0].iov_len = xfersize; 1188 transp_uio.uio_offset = 0; 1189 transp_uio.uio_segflg = UIO_SYSSPACE; 1190 /* 1191 * Since transp_iov points to data, and td_ma page array 1192 * corresponds to original uio->uio_iov, we need to invert the 1193 * direction of the i/o operation as passed to 1194 * uiomove_fromphys(). 1195 */ 1196 switch (uio->uio_rw) { 1197 case UIO_WRITE: 1198 transp_uio.uio_rw = UIO_READ; 1199 break; 1200 case UIO_READ: 1201 transp_uio.uio_rw = UIO_WRITE; 1202 break; 1203 } 1204 transp_uio.uio_td = uio->uio_td; 1205 error = uiomove_fromphys(td->td_ma, 1206 ((vm_offset_t)uio->uio_iov->iov_base) & PAGE_MASK, 1207 xfersize, &transp_uio); 1208 adv = xfersize - transp_uio.uio_resid; 1209 pgadv = 1210 (((vm_offset_t)uio->uio_iov->iov_base + adv) >> PAGE_SHIFT) - 1211 (((vm_offset_t)uio->uio_iov->iov_base) >> PAGE_SHIFT); 1212 td->td_ma += pgadv; 1213 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt, 1214 pgadv)); 1215 td->td_ma_cnt -= pgadv; 1216 uio->uio_iov->iov_base = (char *)uio->uio_iov->iov_base + adv; 1217 uio->uio_iov->iov_len -= adv; 1218 uio->uio_resid -= adv; 1219 uio->uio_offset += adv; 1220 return (error); 1221} 1222 1223int 1224vn_io_fault_pgmove(vm_page_t ma[], vm_offset_t offset, int xfersize, 1225 struct uio *uio) 1226{ 1227 struct thread *td; 1228 vm_offset_t iov_base; 1229 int cnt, pgadv; 1230 1231 td = curthread; 1232 if ((td->td_pflags & TDP_UIOHELD) == 0 || 1233 uio->uio_segflg != UIO_USERSPACE) 1234 return (uiomove_fromphys(ma, offset, xfersize, uio)); 1235 1236 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt)); 1237 cnt = xfersize > uio->uio_resid ? uio->uio_resid : xfersize; 1238 iov_base = (vm_offset_t)uio->uio_iov->iov_base; 1239 switch (uio->uio_rw) { 1240 case UIO_WRITE: 1241 pmap_copy_pages(td->td_ma, iov_base & PAGE_MASK, ma, 1242 offset, cnt); 1243 break; 1244 case UIO_READ: 1245 pmap_copy_pages(ma, offset, td->td_ma, iov_base & PAGE_MASK, 1246 cnt); 1247 break; 1248 } 1249 pgadv = ((iov_base + cnt) >> PAGE_SHIFT) - (iov_base >> PAGE_SHIFT); 1250 td->td_ma += pgadv; 1251 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt, 1252 pgadv)); 1253 td->td_ma_cnt -= pgadv; 1254 uio->uio_iov->iov_base = (char *)(iov_base + cnt); 1255 uio->uio_iov->iov_len -= cnt; 1256 uio->uio_resid -= cnt; 1257 uio->uio_offset += cnt; 1258 return (0); 1259} 1260 1261 1262/* 1263 * File table truncate routine. 1264 */ 1265static int 1266vn_truncate(struct file *fp, off_t length, struct ucred *active_cred, 1267 struct thread *td) 1268{ 1269 struct vattr vattr; 1270 struct mount *mp; 1271 struct vnode *vp; 1272 void *rl_cookie; 1273 int error; 1274 1275 vp = fp->f_vnode; 1276 1277 /* 1278 * Lock the whole range for truncation. Otherwise split i/o 1279 * might happen partly before and partly after the truncation. 1280 */ 1281 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 1282 error = vn_start_write(vp, &mp, V_WAIT | PCATCH); 1283 if (error) 1284 goto out1; 1285 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1286 if (vp->v_type == VDIR) { 1287 error = EISDIR; 1288 goto out; 1289 } 1290#ifdef MAC 1291 error = mac_vnode_check_write(active_cred, fp->f_cred, vp); 1292 if (error) 1293 goto out; 1294#endif 1295 error = vn_writechk(vp); 1296 if (error == 0) { 1297 VATTR_NULL(&vattr); 1298 vattr.va_size = length; 1299 error = VOP_SETATTR(vp, &vattr, fp->f_cred); 1300 } 1301out: 1302 VOP_UNLOCK(vp, 0); 1303 vn_finished_write(mp); 1304out1: 1305 vn_rangelock_unlock(vp, rl_cookie); 1306 return (error); 1307} 1308 1309/* 1310 * File table vnode stat routine. 1311 */ 1312static int 1313vn_statfile(fp, sb, active_cred, td) 1314 struct file *fp; 1315 struct stat *sb; 1316 struct ucred *active_cred; 1317 struct thread *td; 1318{ 1319 struct vnode *vp = fp->f_vnode; 1320 int error; 1321 1322 vn_lock(vp, LK_SHARED | LK_RETRY); 1323 error = vn_stat(vp, sb, active_cred, fp->f_cred, td); 1324 VOP_UNLOCK(vp, 0); 1325 1326 return (error); 1327} 1328 1329/* 1330 * Stat a vnode; implementation for the stat syscall 1331 */ 1332int 1333vn_stat(vp, sb, active_cred, file_cred, td) 1334 struct vnode *vp; 1335 register struct stat *sb; 1336 struct ucred *active_cred; 1337 struct ucred *file_cred; 1338 struct thread *td; 1339{ 1340 struct vattr vattr; 1341 register struct vattr *vap; 1342 int error; 1343 u_short mode; 1344 1345#ifdef MAC 1346 error = mac_vnode_check_stat(active_cred, file_cred, vp); 1347 if (error) 1348 return (error); 1349#endif 1350 1351 vap = &vattr; 1352 1353 /* 1354 * Initialize defaults for new and unusual fields, so that file 1355 * systems which don't support these fields don't need to know 1356 * about them. 1357 */ 1358 vap->va_birthtime.tv_sec = -1; 1359 vap->va_birthtime.tv_nsec = 0; 1360 vap->va_fsid = VNOVAL; 1361 vap->va_rdev = NODEV; 1362 1363 error = VOP_GETATTR(vp, vap, active_cred); 1364 if (error) 1365 return (error); 1366 1367 /* 1368 * Zero the spare stat fields 1369 */ 1370 bzero(sb, sizeof *sb); 1371 1372 /* 1373 * Copy from vattr table 1374 */ 1375 if (vap->va_fsid != VNOVAL) 1376 sb->st_dev = vap->va_fsid; 1377 else 1378 sb->st_dev = vp->v_mount->mnt_stat.f_fsid.val[0]; 1379 sb->st_ino = vap->va_fileid; 1380 mode = vap->va_mode; 1381 switch (vap->va_type) { 1382 case VREG: 1383 mode |= S_IFREG; 1384 break; 1385 case VDIR: 1386 mode |= S_IFDIR; 1387 break; 1388 case VBLK: 1389 mode |= S_IFBLK; 1390 break; 1391 case VCHR: 1392 mode |= S_IFCHR; 1393 break; 1394 case VLNK: 1395 mode |= S_IFLNK; 1396 break; 1397 case VSOCK: 1398 mode |= S_IFSOCK; 1399 break; 1400 case VFIFO: 1401 mode |= S_IFIFO; 1402 break; 1403 default: 1404 return (EBADF); 1405 }; 1406 sb->st_mode = mode; 1407 sb->st_nlink = vap->va_nlink; 1408 sb->st_uid = vap->va_uid; 1409 sb->st_gid = vap->va_gid; 1410 sb->st_rdev = vap->va_rdev; 1411 if (vap->va_size > OFF_MAX) 1412 return (EOVERFLOW); 1413 sb->st_size = vap->va_size; 1414 sb->st_atim = vap->va_atime; 1415 sb->st_mtim = vap->va_mtime; 1416 sb->st_ctim = vap->va_ctime; 1417 sb->st_birthtim = vap->va_birthtime; 1418 1419 /* 1420 * According to www.opengroup.org, the meaning of st_blksize is 1421 * "a filesystem-specific preferred I/O block size for this 1422 * object. In some filesystem types, this may vary from file 1423 * to file" 1424 * Use miminum/default of PAGE_SIZE (e.g. for VCHR). 1425 */ 1426 1427 sb->st_blksize = max(PAGE_SIZE, vap->va_blocksize); 1428 1429 sb->st_flags = vap->va_flags; 1430 if (priv_check(td, PRIV_VFS_GENERATION)) 1431 sb->st_gen = 0; 1432 else 1433 sb->st_gen = vap->va_gen; 1434 1435 sb->st_blocks = vap->va_bytes / S_BLKSIZE; 1436 return (0); 1437} 1438 1439/* 1440 * File table vnode ioctl routine. 1441 */ 1442static int 1443vn_ioctl(fp, com, data, active_cred, td) 1444 struct file *fp; 1445 u_long com; 1446 void *data; 1447 struct ucred *active_cred; 1448 struct thread *td; 1449{ 1450 struct vattr vattr; 1451 struct vnode *vp; 1452 int error; 1453 1454 vp = fp->f_vnode; 1455 switch (vp->v_type) { 1456 case VDIR: 1457 case VREG: 1458 switch (com) { 1459 case FIONREAD: 1460 vn_lock(vp, LK_SHARED | LK_RETRY); 1461 error = VOP_GETATTR(vp, &vattr, active_cred); 1462 VOP_UNLOCK(vp, 0); 1463 if (error == 0) 1464 *(int *)data = vattr.va_size - fp->f_offset; 1465 return (error); 1466 case FIONBIO: 1467 case FIOASYNC: 1468 return (0); 1469 default: 1470 return (VOP_IOCTL(vp, com, data, fp->f_flag, 1471 active_cred, td)); 1472 } 1473 default: 1474 return (ENOTTY); 1475 } 1476} 1477 1478/* 1479 * File table vnode poll routine. 1480 */ 1481static int 1482vn_poll(fp, events, active_cred, td) 1483 struct file *fp; 1484 int events; 1485 struct ucred *active_cred; 1486 struct thread *td; 1487{ 1488 struct vnode *vp; 1489 int error; 1490 1491 vp = fp->f_vnode; 1492#ifdef MAC 1493 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1494 error = mac_vnode_check_poll(active_cred, fp->f_cred, vp); 1495 VOP_UNLOCK(vp, 0); 1496 if (!error) 1497#endif 1498 1499 error = VOP_POLL(vp, events, fp->f_cred, td); 1500 return (error); 1501} 1502 1503/* 1504 * Acquire the requested lock and then check for validity. LK_RETRY 1505 * permits vn_lock to return doomed vnodes. 1506 */ 1507int 1508_vn_lock(struct vnode *vp, int flags, char *file, int line) 1509{ 1510 int error; 1511 1512 VNASSERT((flags & LK_TYPE_MASK) != 0, vp, 1513 ("vn_lock called with no locktype.")); 1514 do { 1515#ifdef DEBUG_VFS_LOCKS 1516 KASSERT(vp->v_holdcnt != 0, 1517 ("vn_lock %p: zero hold count", vp)); 1518#endif 1519 error = VOP_LOCK1(vp, flags, file, line); 1520 flags &= ~LK_INTERLOCK; /* Interlock is always dropped. */ 1521 KASSERT((flags & LK_RETRY) == 0 || error == 0, 1522 ("LK_RETRY set with incompatible flags (0x%x) or an error occured (%d)", 1523 flags, error)); 1524 /* 1525 * Callers specify LK_RETRY if they wish to get dead vnodes. 1526 * If RETRY is not set, we return ENOENT instead. 1527 */ 1528 if (error == 0 && vp->v_iflag & VI_DOOMED && 1529 (flags & LK_RETRY) == 0) { 1530 VOP_UNLOCK(vp, 0); 1531 error = ENOENT; 1532 break; 1533 } 1534 } while (flags & LK_RETRY && error != 0); 1535 return (error); 1536} 1537 1538/* 1539 * File table vnode close routine. 1540 */ 1541static int 1542vn_closefile(fp, td) 1543 struct file *fp; 1544 struct thread *td; 1545{ 1546 struct vnode *vp; 1547 struct flock lf; 1548 int error; 1549 1550 vp = fp->f_vnode; 1551 fp->f_ops = &badfileops; 1552 1553 if (fp->f_type == DTYPE_VNODE && fp->f_flag & FHASLOCK) 1554 vref(vp); 1555 1556 error = vn_close(vp, fp->f_flag, fp->f_cred, td); 1557 1558 if (fp->f_type == DTYPE_VNODE && fp->f_flag & FHASLOCK) { 1559 lf.l_whence = SEEK_SET; 1560 lf.l_start = 0; 1561 lf.l_len = 0; 1562 lf.l_type = F_UNLCK; 1563 (void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, F_FLOCK); 1564 vrele(vp); 1565 } 1566 return (error); 1567} 1568 1569/* 1570 * Preparing to start a filesystem write operation. If the operation is 1571 * permitted, then we bump the count of operations in progress and 1572 * proceed. If a suspend request is in progress, we wait until the 1573 * suspension is over, and then proceed. 1574 */ 1575static int 1576vn_start_write_locked(struct mount *mp, int flags) 1577{ 1578 int error; 1579 1580 mtx_assert(MNT_MTX(mp), MA_OWNED); 1581 error = 0; 1582 1583 /* 1584 * Check on status of suspension. 1585 */ 1586 if ((curthread->td_pflags & TDP_IGNSUSP) == 0 || 1587 mp->mnt_susp_owner != curthread) { 1588 while ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { 1589 if (flags & V_NOWAIT) { 1590 error = EWOULDBLOCK; 1591 goto unlock; 1592 } 1593 error = msleep(&mp->mnt_flag, MNT_MTX(mp), 1594 (PUSER - 1) | (flags & PCATCH), "suspfs", 0); 1595 if (error) 1596 goto unlock; 1597 } 1598 } 1599 if (flags & V_XSLEEP) 1600 goto unlock; 1601 mp->mnt_writeopcount++; 1602unlock: 1603 if (error != 0 || (flags & V_XSLEEP) != 0) 1604 MNT_REL(mp); 1605 MNT_IUNLOCK(mp); 1606 return (error); 1607} 1608 1609int 1610vn_start_write(vp, mpp, flags) 1611 struct vnode *vp; 1612 struct mount **mpp; 1613 int flags; 1614{ 1615 struct mount *mp; 1616 int error; 1617 1618 error = 0; 1619 /* 1620 * If a vnode is provided, get and return the mount point that 1621 * to which it will write. 1622 */ 1623 if (vp != NULL) { 1624 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) { 1625 *mpp = NULL; 1626 if (error != EOPNOTSUPP) 1627 return (error); 1628 return (0); 1629 } 1630 } 1631 if ((mp = *mpp) == NULL) 1632 return (0); 1633 1634 /* 1635 * VOP_GETWRITEMOUNT() returns with the mp refcount held through 1636 * a vfs_ref(). 1637 * As long as a vnode is not provided we need to acquire a 1638 * refcount for the provided mountpoint too, in order to 1639 * emulate a vfs_ref(). 1640 */ 1641 MNT_ILOCK(mp); 1642 if (vp == NULL) 1643 MNT_REF(mp); 1644 1645 return (vn_start_write_locked(mp, flags)); 1646} 1647 1648/* 1649 * Secondary suspension. Used by operations such as vop_inactive 1650 * routines that are needed by the higher level functions. These 1651 * are allowed to proceed until all the higher level functions have 1652 * completed (indicated by mnt_writeopcount dropping to zero). At that 1653 * time, these operations are halted until the suspension is over. 1654 */ 1655int 1656vn_start_secondary_write(vp, mpp, flags) 1657 struct vnode *vp; 1658 struct mount **mpp; 1659 int flags; 1660{ 1661 struct mount *mp; 1662 int error; 1663 1664 retry: 1665 if (vp != NULL) { 1666 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) { 1667 *mpp = NULL; 1668 if (error != EOPNOTSUPP) 1669 return (error); 1670 return (0); 1671 } 1672 } 1673 /* 1674 * If we are not suspended or have not yet reached suspended 1675 * mode, then let the operation proceed. 1676 */ 1677 if ((mp = *mpp) == NULL) 1678 return (0); 1679 1680 /* 1681 * VOP_GETWRITEMOUNT() returns with the mp refcount held through 1682 * a vfs_ref(). 1683 * As long as a vnode is not provided we need to acquire a 1684 * refcount for the provided mountpoint too, in order to 1685 * emulate a vfs_ref(). 1686 */ 1687 MNT_ILOCK(mp); 1688 if (vp == NULL) 1689 MNT_REF(mp); 1690 if ((mp->mnt_kern_flag & (MNTK_SUSPENDED | MNTK_SUSPEND2)) == 0) { 1691 mp->mnt_secondary_writes++; 1692 mp->mnt_secondary_accwrites++; 1693 MNT_IUNLOCK(mp); 1694 return (0); 1695 } 1696 if (flags & V_NOWAIT) { 1697 MNT_REL(mp); 1698 MNT_IUNLOCK(mp); 1699 return (EWOULDBLOCK); 1700 } 1701 /* 1702 * Wait for the suspension to finish. 1703 */ 1704 error = msleep(&mp->mnt_flag, MNT_MTX(mp), 1705 (PUSER - 1) | (flags & PCATCH) | PDROP, "suspfs", 0); 1706 vfs_rel(mp); 1707 if (error == 0) 1708 goto retry; 1709 return (error); 1710} 1711 1712/* 1713 * Filesystem write operation has completed. If we are suspending and this 1714 * operation is the last one, notify the suspender that the suspension is 1715 * now in effect. 1716 */ 1717void 1718vn_finished_write(mp) 1719 struct mount *mp; 1720{ 1721 if (mp == NULL) 1722 return; 1723 MNT_ILOCK(mp); 1724 MNT_REL(mp); 1725 mp->mnt_writeopcount--; 1726 if (mp->mnt_writeopcount < 0) 1727 panic("vn_finished_write: neg cnt"); 1728 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && 1729 mp->mnt_writeopcount <= 0) 1730 wakeup(&mp->mnt_writeopcount); 1731 MNT_IUNLOCK(mp); 1732} 1733 1734 1735/* 1736 * Filesystem secondary write operation has completed. If we are 1737 * suspending and this operation is the last one, notify the suspender 1738 * that the suspension is now in effect. 1739 */ 1740void 1741vn_finished_secondary_write(mp) 1742 struct mount *mp; 1743{ 1744 if (mp == NULL) 1745 return; 1746 MNT_ILOCK(mp); 1747 MNT_REL(mp); 1748 mp->mnt_secondary_writes--; 1749 if (mp->mnt_secondary_writes < 0) 1750 panic("vn_finished_secondary_write: neg cnt"); 1751 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && 1752 mp->mnt_secondary_writes <= 0) 1753 wakeup(&mp->mnt_secondary_writes); 1754 MNT_IUNLOCK(mp); 1755} 1756 1757 1758 1759/* 1760 * Request a filesystem to suspend write operations. 1761 */ 1762int 1763vfs_write_suspend(struct mount *mp, int flags) 1764{ 1765 int error; 1766 1767 MNT_ILOCK(mp); 1768 if (mp->mnt_susp_owner == curthread) { 1769 MNT_IUNLOCK(mp); 1770 return (EALREADY); 1771 } 1772 while (mp->mnt_kern_flag & MNTK_SUSPEND) 1773 msleep(&mp->mnt_flag, MNT_MTX(mp), PUSER - 1, "wsuspfs", 0); 1774 1775 /* 1776 * Unmount holds a write reference on the mount point. If we 1777 * own busy reference and drain for writers, we deadlock with 1778 * the reference draining in the unmount path. Callers of 1779 * vfs_write_suspend() must specify VS_SKIP_UNMOUNT if 1780 * vfs_busy() reference is owned and caller is not in the 1781 * unmount context. 1782 */ 1783 if ((flags & VS_SKIP_UNMOUNT) != 0 && 1784 (mp->mnt_kern_flag & MNTK_UNMOUNT) != 0) { 1785 MNT_IUNLOCK(mp); 1786 return (EBUSY); 1787 } 1788 1789 mp->mnt_kern_flag |= MNTK_SUSPEND; 1790 mp->mnt_susp_owner = curthread; 1791 if (mp->mnt_writeopcount > 0) 1792 (void) msleep(&mp->mnt_writeopcount, 1793 MNT_MTX(mp), (PUSER - 1)|PDROP, "suspwt", 0); 1794 else 1795 MNT_IUNLOCK(mp); 1796 if ((error = VFS_SYNC(mp, MNT_SUSPEND)) != 0) 1797 vfs_write_resume(mp, 0); 1798 return (error); 1799} 1800 1801/* 1802 * Request a filesystem to resume write operations. 1803 */ 1804void 1805vfs_write_resume(struct mount *mp, int flags) 1806{ 1807 1808 MNT_ILOCK(mp); 1809 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { 1810 KASSERT(mp->mnt_susp_owner == curthread, ("mnt_susp_owner")); 1811 mp->mnt_kern_flag &= ~(MNTK_SUSPEND | MNTK_SUSPEND2 | 1812 MNTK_SUSPENDED); 1813 mp->mnt_susp_owner = NULL; 1814 wakeup(&mp->mnt_writeopcount); 1815 wakeup(&mp->mnt_flag); 1816 curthread->td_pflags &= ~TDP_IGNSUSP; 1817 if ((flags & VR_START_WRITE) != 0) { 1818 MNT_REF(mp); 1819 mp->mnt_writeopcount++; 1820 } 1821 MNT_IUNLOCK(mp); 1822 if ((flags & VR_NO_SUSPCLR) == 0) 1823 VFS_SUSP_CLEAN(mp); 1824 } else if ((flags & VR_START_WRITE) != 0) { 1825 MNT_REF(mp); 1826 vn_start_write_locked(mp, 0); 1827 } else { 1828 MNT_IUNLOCK(mp); 1829 } 1830} 1831 1832/* 1833 * Helper loop around vfs_write_suspend() for filesystem unmount VFS 1834 * methods. 1835 */ 1836int 1837vfs_write_suspend_umnt(struct mount *mp) 1838{ 1839 int error; 1840 1841 KASSERT((curthread->td_pflags & TDP_IGNSUSP) == 0, 1842 ("vfs_write_suspend_umnt: recursed")); 1843 1844 /* dounmount() already called vn_start_write(). */ 1845 for (;;) { 1846 vn_finished_write(mp); 1847 error = vfs_write_suspend(mp, 0); 1848 if (error != 0) 1849 return (error); 1850 MNT_ILOCK(mp); 1851 if ((mp->mnt_kern_flag & MNTK_SUSPENDED) != 0) 1852 break; 1853 MNT_IUNLOCK(mp); 1854 vn_start_write(NULL, &mp, V_WAIT); 1855 } 1856 mp->mnt_kern_flag &= ~(MNTK_SUSPENDED | MNTK_SUSPEND2); 1857 wakeup(&mp->mnt_flag); 1858 MNT_IUNLOCK(mp); 1859 curthread->td_pflags |= TDP_IGNSUSP; 1860 return (0); 1861} 1862 1863/* 1864 * Implement kqueues for files by translating it to vnode operation. 1865 */ 1866static int 1867vn_kqfilter(struct file *fp, struct knote *kn) 1868{ 1869 1870 return (VOP_KQFILTER(fp->f_vnode, kn)); 1871} 1872 1873/* 1874 * Simplified in-kernel wrapper calls for extended attribute access. 1875 * Both calls pass in a NULL credential, authorizing as "kernel" access. 1876 * Set IO_NODELOCKED in ioflg if the vnode is already locked. 1877 */ 1878int 1879vn_extattr_get(struct vnode *vp, int ioflg, int attrnamespace, 1880 const char *attrname, int *buflen, char *buf, struct thread *td) 1881{ 1882 struct uio auio; 1883 struct iovec iov; 1884 int error; 1885 1886 iov.iov_len = *buflen; 1887 iov.iov_base = buf; 1888 1889 auio.uio_iov = &iov; 1890 auio.uio_iovcnt = 1; 1891 auio.uio_rw = UIO_READ; 1892 auio.uio_segflg = UIO_SYSSPACE; 1893 auio.uio_td = td; 1894 auio.uio_offset = 0; 1895 auio.uio_resid = *buflen; 1896 1897 if ((ioflg & IO_NODELOCKED) == 0) 1898 vn_lock(vp, LK_SHARED | LK_RETRY); 1899 1900 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 1901 1902 /* authorize attribute retrieval as kernel */ 1903 error = VOP_GETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, NULL, 1904 td); 1905 1906 if ((ioflg & IO_NODELOCKED) == 0) 1907 VOP_UNLOCK(vp, 0); 1908 1909 if (error == 0) { 1910 *buflen = *buflen - auio.uio_resid; 1911 } 1912 1913 return (error); 1914} 1915 1916/* 1917 * XXX failure mode if partially written? 1918 */ 1919int 1920vn_extattr_set(struct vnode *vp, int ioflg, int attrnamespace, 1921 const char *attrname, int buflen, char *buf, struct thread *td) 1922{ 1923 struct uio auio; 1924 struct iovec iov; 1925 struct mount *mp; 1926 int error; 1927 1928 iov.iov_len = buflen; 1929 iov.iov_base = buf; 1930 1931 auio.uio_iov = &iov; 1932 auio.uio_iovcnt = 1; 1933 auio.uio_rw = UIO_WRITE; 1934 auio.uio_segflg = UIO_SYSSPACE; 1935 auio.uio_td = td; 1936 auio.uio_offset = 0; 1937 auio.uio_resid = buflen; 1938 1939 if ((ioflg & IO_NODELOCKED) == 0) { 1940 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) 1941 return (error); 1942 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1943 } 1944 1945 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 1946 1947 /* authorize attribute setting as kernel */ 1948 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, td); 1949 1950 if ((ioflg & IO_NODELOCKED) == 0) { 1951 vn_finished_write(mp); 1952 VOP_UNLOCK(vp, 0); 1953 } 1954 1955 return (error); 1956} 1957 1958int 1959vn_extattr_rm(struct vnode *vp, int ioflg, int attrnamespace, 1960 const char *attrname, struct thread *td) 1961{ 1962 struct mount *mp; 1963 int error; 1964 1965 if ((ioflg & IO_NODELOCKED) == 0) { 1966 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) 1967 return (error); 1968 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1969 } 1970 1971 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); 1972 1973 /* authorize attribute removal as kernel */ 1974 error = VOP_DELETEEXTATTR(vp, attrnamespace, attrname, NULL, td); 1975 if (error == EOPNOTSUPP) 1976 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, NULL, 1977 NULL, td); 1978 1979 if ((ioflg & IO_NODELOCKED) == 0) { 1980 vn_finished_write(mp); 1981 VOP_UNLOCK(vp, 0); 1982 } 1983 1984 return (error); 1985} 1986 1987static int 1988vn_get_ino_alloc_vget(struct mount *mp, void *arg, int lkflags, 1989 struct vnode **rvp) 1990{ 1991 1992 return (VFS_VGET(mp, *(ino_t *)arg, lkflags, rvp)); 1993} 1994 1995int 1996vn_vget_ino(struct vnode *vp, ino_t ino, int lkflags, struct vnode **rvp) 1997{ 1998 1999 return (vn_vget_ino_gen(vp, vn_get_ino_alloc_vget, &ino, 2000 lkflags, rvp)); 2001} 2002 2003int 2004vn_vget_ino_gen(struct vnode *vp, vn_get_ino_t alloc, void *alloc_arg, 2005 int lkflags, struct vnode **rvp) 2006{ 2007 struct mount *mp; 2008 int ltype, error; 2009 2010 ASSERT_VOP_LOCKED(vp, "vn_vget_ino_get"); 2011 mp = vp->v_mount; 2012 ltype = VOP_ISLOCKED(vp); 2013 KASSERT(ltype == LK_EXCLUSIVE || ltype == LK_SHARED, 2014 ("vn_vget_ino: vp not locked")); 2015 error = vfs_busy(mp, MBF_NOWAIT); 2016 if (error != 0) { 2017 vfs_ref(mp); 2018 VOP_UNLOCK(vp, 0); 2019 error = vfs_busy(mp, 0); 2020 vn_lock(vp, ltype | LK_RETRY); 2021 vfs_rel(mp); 2022 if (error != 0) 2023 return (ENOENT); 2024 if (vp->v_iflag & VI_DOOMED) { 2025 vfs_unbusy(mp); 2026 return (ENOENT); 2027 } 2028 } 2029 VOP_UNLOCK(vp, 0); 2030 error = alloc(mp, alloc_arg, lkflags, rvp); 2031 vfs_unbusy(mp); 2032 if (*rvp != vp) 2033 vn_lock(vp, ltype | LK_RETRY); 2034 if (vp->v_iflag & VI_DOOMED) { 2035 if (error == 0) { 2036 if (*rvp == vp) 2037 vunref(vp); 2038 else 2039 vput(*rvp); 2040 } 2041 error = ENOENT; 2042 } 2043 return (error); 2044} 2045 2046int 2047vn_rlimit_fsize(const struct vnode *vp, const struct uio *uio, 2048 const struct thread *td) 2049{ 2050 2051 if (vp->v_type != VREG || td == NULL) 2052 return (0); 2053 PROC_LOCK(td->td_proc); 2054 if ((uoff_t)uio->uio_offset + uio->uio_resid > 2055 lim_cur(td->td_proc, RLIMIT_FSIZE)) { 2056 kern_psignal(td->td_proc, SIGXFSZ); 2057 PROC_UNLOCK(td->td_proc); 2058 return (EFBIG); 2059 } 2060 PROC_UNLOCK(td->td_proc); 2061 return (0); 2062} 2063 2064int 2065vn_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 2066 struct thread *td) 2067{ 2068 struct vnode *vp; 2069 2070 vp = fp->f_vnode; 2071#ifdef AUDIT 2072 vn_lock(vp, LK_SHARED | LK_RETRY); 2073 AUDIT_ARG_VNODE1(vp); 2074 VOP_UNLOCK(vp, 0); 2075#endif 2076 return (setfmode(td, active_cred, vp, mode)); 2077} 2078 2079int 2080vn_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 2081 struct thread *td) 2082{ 2083 struct vnode *vp; 2084 2085 vp = fp->f_vnode; 2086#ifdef AUDIT 2087 vn_lock(vp, LK_SHARED | LK_RETRY); 2088 AUDIT_ARG_VNODE1(vp); 2089 VOP_UNLOCK(vp, 0); 2090#endif 2091 return (setfown(td, active_cred, vp, uid, gid)); 2092} 2093 2094void 2095vn_pages_remove(struct vnode *vp, vm_pindex_t start, vm_pindex_t end) 2096{ 2097 vm_object_t object; 2098 2099 if ((object = vp->v_object) == NULL) 2100 return; 2101 VM_OBJECT_WLOCK(object); 2102 vm_object_page_remove(object, start, end, 0); 2103 VM_OBJECT_WUNLOCK(object); 2104} 2105 2106int 2107vn_bmap_seekhole(struct vnode *vp, u_long cmd, off_t *off, struct ucred *cred) 2108{ 2109 struct vattr va; 2110 daddr_t bn, bnp; 2111 uint64_t bsize; 2112 off_t noff; 2113 int error; 2114 2115 KASSERT(cmd == FIOSEEKHOLE || cmd == FIOSEEKDATA, 2116 ("Wrong command %lu", cmd)); 2117 2118 if (vn_lock(vp, LK_SHARED) != 0) 2119 return (EBADF); 2120 if (vp->v_type != VREG) { 2121 error = ENOTTY; 2122 goto unlock; 2123 } 2124 error = VOP_GETATTR(vp, &va, cred); 2125 if (error != 0) 2126 goto unlock; 2127 noff = *off; 2128 if (noff >= va.va_size) { 2129 error = ENXIO; 2130 goto unlock; 2131 } 2132 bsize = vp->v_mount->mnt_stat.f_iosize; 2133 for (bn = noff / bsize; noff < va.va_size; bn++, noff += bsize) { 2134 error = VOP_BMAP(vp, bn, NULL, &bnp, NULL, NULL); 2135 if (error == EOPNOTSUPP) { 2136 error = ENOTTY; 2137 goto unlock; 2138 } 2139 if ((bnp == -1 && cmd == FIOSEEKHOLE) || 2140 (bnp != -1 && cmd == FIOSEEKDATA)) { 2141 noff = bn * bsize; 2142 if (noff < *off) 2143 noff = *off; 2144 goto unlock; 2145 } 2146 } 2147 if (noff > va.va_size) 2148 noff = va.va_size; 2149 /* noff == va.va_size. There is an implicit hole at the end of file. */ 2150 if (cmd == FIOSEEKDATA) 2151 error = ENXIO; 2152unlock: 2153 VOP_UNLOCK(vp, 0); 2154 if (error == 0) 2155 *off = noff; 2156 return (error); 2157} 2158 2159int 2160vn_seek(struct file *fp, off_t offset, int whence, struct thread *td) 2161{ 2162 struct ucred *cred; 2163 struct vnode *vp; 2164 struct vattr vattr; 2165 off_t foffset, size; 2166 int error, noneg; 2167 2168 cred = td->td_ucred; 2169 vp = fp->f_vnode; 2170 foffset = foffset_lock(fp, 0); 2171 noneg = (vp->v_type != VCHR); 2172 error = 0; 2173 switch (whence) { 2174 case L_INCR: 2175 if (noneg && 2176 (foffset < 0 || 2177 (offset > 0 && foffset > OFF_MAX - offset))) { 2178 error = EOVERFLOW; 2179 break; 2180 } 2181 offset += foffset; 2182 break; 2183 case L_XTND: 2184 vn_lock(vp, LK_SHARED | LK_RETRY); 2185 error = VOP_GETATTR(vp, &vattr, cred); 2186 VOP_UNLOCK(vp, 0); 2187 if (error) 2188 break; 2189 2190 /* 2191 * If the file references a disk device, then fetch 2192 * the media size and use that to determine the ending 2193 * offset. 2194 */ 2195 if (vattr.va_size == 0 && vp->v_type == VCHR && 2196 fo_ioctl(fp, DIOCGMEDIASIZE, &size, cred, td) == 0) 2197 vattr.va_size = size; 2198 if (noneg && 2199 (vattr.va_size > OFF_MAX || 2200 (offset > 0 && vattr.va_size > OFF_MAX - offset))) { 2201 error = EOVERFLOW; 2202 break; 2203 } 2204 offset += vattr.va_size; 2205 break; 2206 case L_SET: 2207 break; 2208 case SEEK_DATA: 2209 error = fo_ioctl(fp, FIOSEEKDATA, &offset, cred, td); 2210 break; 2211 case SEEK_HOLE: 2212 error = fo_ioctl(fp, FIOSEEKHOLE, &offset, cred, td); 2213 break; 2214 default: 2215 error = EINVAL; 2216 } 2217 if (error == 0 && noneg && offset < 0) 2218 error = EINVAL; 2219 if (error != 0) 2220 goto drop; 2221 VFS_KNOTE_UNLOCKED(vp, 0); 2222 *(off_t *)(td->td_retval) = offset; 2223drop: 2224 foffset_unlock(fp, offset, error != 0 ? FOF_NOUPDATE : 0); 2225 return (error); 2226} 2227 2228int 2229vn_utimes_perm(struct vnode *vp, struct vattr *vap, struct ucred *cred, 2230 struct thread *td) 2231{ 2232 int error; 2233 2234 error = VOP_ACCESSX(vp, VWRITE_ATTRIBUTES, cred, td); 2235 2236 /* 2237 * From utimes(2): 2238 * Grant permission if the caller is the owner of the file or 2239 * the super-user. If the time pointer is null, then write 2240 * permission on the file is also sufficient. 2241 * 2242 * From NFSv4.1, draft 21, 6.2.1.3.1, Discussion of Mask Attributes: 2243 * A user having ACL_WRITE_DATA or ACL_WRITE_ATTRIBUTES 2244 * will be allowed to set the times [..] to the current 2245 * server time. 2246 */ 2247 if (error != 0 && (vap->va_vaflags & VA_UTIMES_NULL) != 0) 2248 error = VOP_ACCESS(vp, VWRITE, cred, td); 2249 return (error); 2250} 2251