1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 2007-2009 Google Inc. and Amit Singh 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions are 9 * met: 10 * 11 * * Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * * Redistributions in binary form must reproduce the above 14 * copyright notice, this list of conditions and the following disclaimer 15 * in the documentation and/or other materials provided with the 16 * distribution. 17 * * Neither the name of Google Inc. nor the names of its 18 * contributors may be used to endorse or promote products derived from 19 * this software without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 24 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 25 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 26 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 27 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 31 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 * 33 * Copyright (C) 2005 Csaba Henk. 34 * All rights reserved. 35 * 36 * Copyright (c) 2019 The FreeBSD Foundation 37 * 38 * Portions of this software were developed by BFF Storage Systems, LLC under 39 * sponsorship from the FreeBSD Foundation. 40 * 41 * Redistribution and use in source and binary forms, with or without 42 * modification, are permitted provided that the following conditions 43 * are met: 44 * 1. Redistributions of source code must retain the above copyright 45 * notice, this list of conditions and the following disclaimer. 46 * 2. Redistributions in binary form must reproduce the above copyright 47 * notice, this list of conditions and the following disclaimer in the 48 * documentation and/or other materials provided with the distribution. 49 * 50 * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND 51 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 52 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 53 * ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE 54 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 55 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 56 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 57 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 58 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 59 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 60 * SUCH DAMAGE. 61 */ 62 63 #include <sys/cdefs.h> 64 __FBSDID("$FreeBSD$"); 65 66 #include <sys/param.h> 67 #include <sys/buf.h> 68 #include <sys/module.h> 69 #include <sys/systm.h> 70 #include <sys/errno.h> 71 #include <sys/kernel.h> 72 #include <sys/capsicum.h> 73 #include <sys/conf.h> 74 #include <sys/filedesc.h> 75 #include <sys/uio.h> 76 #include <sys/malloc.h> 77 #include <sys/queue.h> 78 #include <sys/lock.h> 79 #include <sys/sx.h> 80 #include <sys/mutex.h> 81 #include <sys/proc.h> 82 #include <sys/vnode.h> 83 #include <sys/namei.h> 84 #include <sys/mount.h> 85 #include <sys/sysctl.h> 86 #include <sys/fcntl.h> 87 88 #include "fuse.h" 89 #include "fuse_node.h" 90 #include "fuse_ipc.h" 91 #include "fuse_internal.h" 92 93 #include <sys/priv.h> 94 #include <security/mac/mac_framework.h> 95 96 SDT_PROVIDER_DECLARE(fusefs); 97 /* 98 * Fuse trace probe: 99 * arg0: verbosity. Higher numbers give more verbose messages 100 * arg1: Textual message 101 */ 102 SDT_PROBE_DEFINE2(fusefs, , vfsops, trace, "int", "char*"); 103 104 /* This will do for privilege types for now */ 105 #ifndef PRIV_VFS_FUSE_ALLOWOTHER 106 #define PRIV_VFS_FUSE_ALLOWOTHER PRIV_VFS_MOUNT_NONUSER 107 #endif 108 #ifndef PRIV_VFS_FUSE_MOUNT_NONUSER 109 #define PRIV_VFS_FUSE_MOUNT_NONUSER PRIV_VFS_MOUNT_NONUSER 110 #endif 111 #ifndef PRIV_VFS_FUSE_SYNC_UNMOUNT 112 #define PRIV_VFS_FUSE_SYNC_UNMOUNT PRIV_VFS_MOUNT_NONUSER 113 #endif 114 115 static vfs_fhtovp_t fuse_vfsop_fhtovp; 116 static vfs_mount_t fuse_vfsop_mount; 117 static vfs_unmount_t fuse_vfsop_unmount; 118 static vfs_root_t fuse_vfsop_root; 119 static vfs_statfs_t fuse_vfsop_statfs; 120 static vfs_vget_t fuse_vfsop_vget; 121 122 struct vfsops fuse_vfsops = { 123 .vfs_fhtovp = fuse_vfsop_fhtovp, 124 .vfs_mount = fuse_vfsop_mount, 125 .vfs_unmount = fuse_vfsop_unmount, 126 .vfs_root = fuse_vfsop_root, 127 .vfs_statfs = fuse_vfsop_statfs, 128 .vfs_vget = fuse_vfsop_vget, 129 }; 130 131 static int fuse_enforce_dev_perms = 0; 132 133 SYSCTL_INT(_vfs_fusefs, OID_AUTO, enforce_dev_perms, CTLFLAG_RW, 134 &fuse_enforce_dev_perms, 0, 135 "enforce fuse device permissions for secondary mounts"); 136 137 MALLOC_DEFINE(M_FUSEVFS, "fuse_filesystem", "buffer for fuse vfs layer"); 138 139 static int 140 fuse_getdevice(const char *fspec, struct thread *td, struct cdev **fdevp) 141 { 142 struct nameidata nd, *ndp = &nd; 143 struct vnode *devvp; 144 struct cdev *fdev; 145 int err; 146 147 /* 148 * Not an update, or updating the name: look up the name 149 * and verify that it refers to a sensible disk device. 150 */ 151 152 NDINIT(ndp, LOOKUP, FOLLOW, UIO_SYSSPACE, fspec, td); 153 if ((err = namei(ndp)) != 0) 154 return err; 155 NDFREE(ndp, NDF_ONLY_PNBUF); 156 devvp = ndp->ni_vp; 157 158 if (devvp->v_type != VCHR) { 159 vrele(devvp); 160 return ENXIO; 161 } 162 fdev = devvp->v_rdev; 163 dev_ref(fdev); 164 165 if (fuse_enforce_dev_perms) { 166 /* 167 * Check if mounter can open the fuse device. 168 * 169 * This has significance only if we are doing a secondary mount 170 * which doesn't involve actually opening fuse devices, but we 171 * still want to enforce the permissions of the device (in 172 * order to keep control over the circle of fuse users). 173 * 174 * (In case of primary mounts, we are either the superuser so 175 * we can do anything anyway, or we can mount only if the 176 * device is already opened by us, ie. we are permitted to open 177 * the device.) 178 */ 179 #if 0 180 #ifdef MAC 181 err = mac_check_vnode_open(td->td_ucred, devvp, VREAD | VWRITE); 182 if (!err) 183 #endif 184 #endif /* 0 */ 185 err = VOP_ACCESS(devvp, VREAD | VWRITE, td->td_ucred, td); 186 if (err) { 187 vrele(devvp); 188 dev_rel(fdev); 189 return err; 190 } 191 } 192 /* 193 * according to coda code, no extra lock is needed -- 194 * although in sys/vnode.h this field is marked "v" 195 */ 196 vrele(devvp); 197 198 if (!fdev->si_devsw || 199 strcmp("fuse", fdev->si_devsw->d_name)) { 200 dev_rel(fdev); 201 return ENXIO; 202 } 203 *fdevp = fdev; 204 205 return 0; 206 } 207 208 #define FUSE_FLAGOPT(fnam, fval) do { \ 209 vfs_flagopt(opts, #fnam, &mntopts, fval); \ 210 vfs_flagopt(opts, "__" #fnam, &__mntopts, fval); \ 211 } while (0) 212 213 SDT_PROBE_DEFINE1(fusefs, , vfsops, mntopts, "uint64_t"); 214 SDT_PROBE_DEFINE4(fusefs, , vfsops, mount_err, "char*", "struct fuse_data*", 215 "struct mount*", "int"); 216 217 static int 218 fuse_vfs_remount(struct mount *mp, struct thread *td, uint64_t mntopts, 219 uint32_t max_read, int daemon_timeout) 220 { 221 int err = 0; 222 struct fuse_data *data = fuse_get_mpdata(mp); 223 /* Don't allow these options to be changed */ 224 const static unsigned long long cant_update_opts = 225 MNT_USER; /* Mount owner must be the user running the daemon */ 226 227 FUSE_LOCK(); 228 229 if ((mp->mnt_flag ^ data->mnt_flag) & cant_update_opts) { 230 err = EOPNOTSUPP; 231 SDT_PROBE4(fusefs, , vfsops, mount_err, 232 "Can't change these mount options during remount", 233 data, mp, err); 234 goto out; 235 } 236 if (((data->dataflags ^ mntopts) & FSESS_MNTOPTS_MASK) || 237 (data->max_read != max_read) || 238 (data->daemon_timeout != daemon_timeout)) { 239 // TODO: allow changing options where it makes sense 240 err = EOPNOTSUPP; 241 SDT_PROBE4(fusefs, , vfsops, mount_err, 242 "Can't change fuse mount options during remount", 243 data, mp, err); 244 goto out; 245 } 246 247 if (fdata_get_dead(data)) { 248 err = ENOTCONN; 249 SDT_PROBE4(fusefs, , vfsops, mount_err, 250 "device is dead during mount", data, mp, err); 251 goto out; 252 } 253 254 /* Sanity + permission checks */ 255 if (!data->daemoncred) 256 panic("fuse daemon found, but identity unknown"); 257 if (mntopts & FSESS_DAEMON_CAN_SPY) 258 err = priv_check(td, PRIV_VFS_FUSE_ALLOWOTHER); 259 if (err == 0 && td->td_ucred->cr_uid != data->daemoncred->cr_uid) 260 /* are we allowed to do the first mount? */ 261 err = priv_check(td, PRIV_VFS_FUSE_MOUNT_NONUSER); 262 263 out: 264 FUSE_UNLOCK(); 265 return err; 266 } 267 268 static int 269 fuse_vfsop_fhtovp(struct mount *mp, struct fid *fhp, int flags, 270 struct vnode **vpp) 271 { 272 struct fuse_fid *ffhp = (struct fuse_fid *)fhp; 273 struct fuse_vnode_data *fvdat; 274 struct vnode *nvp; 275 int error; 276 277 if (!(fuse_get_mpdata(mp)->dataflags & FSESS_EXPORT_SUPPORT)) 278 return EOPNOTSUPP; 279 280 error = VFS_VGET(mp, ffhp->nid, LK_EXCLUSIVE, &nvp); 281 if (error) { 282 *vpp = NULLVP; 283 return (error); 284 } 285 fvdat = VTOFUD(nvp); 286 if (fvdat->generation != ffhp->gen ) { 287 vput(nvp); 288 *vpp = NULLVP; 289 return (ESTALE); 290 } 291 *vpp = nvp; 292 vnode_create_vobject(*vpp, 0, curthread); 293 return (0); 294 } 295 296 static int 297 fuse_vfsop_mount(struct mount *mp) 298 { 299 int err; 300 301 uint64_t mntopts, __mntopts; 302 uint32_t max_read; 303 int daemon_timeout; 304 int fd; 305 306 struct cdev *fdev; 307 struct fuse_data *data = NULL; 308 struct thread *td; 309 struct file *fp, *fptmp; 310 char *fspec, *subtype; 311 struct vfsoptlist *opts; 312 313 subtype = NULL; 314 max_read = ~0; 315 err = 0; 316 mntopts = 0; 317 __mntopts = 0; 318 td = curthread; 319 320 /* Get the new options passed to mount */ 321 opts = mp->mnt_optnew; 322 323 if (!opts) 324 return EINVAL; 325 326 /* `fspath' contains the mount point (eg. /mnt/fuse/sshfs); REQUIRED */ 327 if (!vfs_getopts(opts, "fspath", &err)) 328 return err; 329 330 /* 331 * With the help of underscored options the mount program 332 * can inform us from the flags it sets by default 333 */ 334 FUSE_FLAGOPT(allow_other, FSESS_DAEMON_CAN_SPY); 335 FUSE_FLAGOPT(push_symlinks_in, FSESS_PUSH_SYMLINKS_IN); 336 FUSE_FLAGOPT(default_permissions, FSESS_DEFAULT_PERMISSIONS); 337 FUSE_FLAGOPT(intr, FSESS_INTR); 338 339 (void)vfs_scanopt(opts, "max_read=", "%u", &max_read); 340 if (vfs_scanopt(opts, "timeout=", "%u", &daemon_timeout) == 1) { 341 if (daemon_timeout < FUSE_MIN_DAEMON_TIMEOUT) 342 daemon_timeout = FUSE_MIN_DAEMON_TIMEOUT; 343 else if (daemon_timeout > FUSE_MAX_DAEMON_TIMEOUT) 344 daemon_timeout = FUSE_MAX_DAEMON_TIMEOUT; 345 } else { 346 daemon_timeout = FUSE_DEFAULT_DAEMON_TIMEOUT; 347 } 348 subtype = vfs_getopts(opts, "subtype=", &err); 349 350 SDT_PROBE1(fusefs, , vfsops, mntopts, mntopts); 351 352 if (mp->mnt_flag & MNT_UPDATE) { 353 return fuse_vfs_remount(mp, td, mntopts, max_read, 354 daemon_timeout); 355 } 356 357 /* `from' contains the device name (eg. /dev/fuse0); REQUIRED */ 358 fspec = vfs_getopts(opts, "from", &err); 359 if (!fspec) 360 return err; 361 362 /* `fd' contains the filedescriptor for this session; REQUIRED */ 363 if (vfs_scanopt(opts, "fd", "%d", &fd) != 1) 364 return EINVAL; 365 366 err = fuse_getdevice(fspec, td, &fdev); 367 if (err != 0) 368 return err; 369 370 err = fget(td, fd, &cap_read_rights, &fp); 371 if (err != 0) { 372 SDT_PROBE2(fusefs, , vfsops, trace, 1, 373 "invalid or not opened device"); 374 goto out; 375 } 376 fptmp = td->td_fpop; 377 td->td_fpop = fp; 378 err = devfs_get_cdevpriv((void **)&data); 379 td->td_fpop = fptmp; 380 fdrop(fp, td); 381 FUSE_LOCK(); 382 383 if (err != 0 || data == NULL) { 384 err = ENXIO; 385 SDT_PROBE4(fusefs, , vfsops, mount_err, 386 "invalid or not opened device", data, mp, err); 387 FUSE_UNLOCK(); 388 goto out; 389 } 390 if (fdata_get_dead(data)) { 391 err = ENOTCONN; 392 SDT_PROBE4(fusefs, , vfsops, mount_err, 393 "device is dead during mount", data, mp, err); 394 FUSE_UNLOCK(); 395 goto out; 396 } 397 /* Sanity + permission checks */ 398 if (!data->daemoncred) 399 panic("fuse daemon found, but identity unknown"); 400 if (mntopts & FSESS_DAEMON_CAN_SPY) 401 err = priv_check(td, PRIV_VFS_FUSE_ALLOWOTHER); 402 if (err == 0 && td->td_ucred->cr_uid != data->daemoncred->cr_uid) 403 /* are we allowed to do the first mount? */ 404 err = priv_check(td, PRIV_VFS_FUSE_MOUNT_NONUSER); 405 if (err) { 406 FUSE_UNLOCK(); 407 goto out; 408 } 409 data->ref++; 410 data->mp = mp; 411 data->dataflags |= mntopts; 412 data->max_read = max_read; 413 data->daemon_timeout = daemon_timeout; 414 data->mnt_flag = mp->mnt_flag & MNT_UPDATEMASK; 415 FUSE_UNLOCK(); 416 417 vfs_getnewfsid(mp); 418 MNT_ILOCK(mp); 419 mp->mnt_data = data; 420 /* 421 * FUSE file systems can be either local or remote, but the kernel 422 * can't tell the difference. 423 */ 424 mp->mnt_flag &= ~MNT_LOCAL; 425 mp->mnt_kern_flag |= MNTK_USES_BCACHE; 426 /* 427 * Disable nullfs cacheing because it can consume too many resources in 428 * the FUSE server. 429 */ 430 mp->mnt_kern_flag |= MNTK_NULL_NOCACHE; 431 MNT_IUNLOCK(mp); 432 /* We need this here as this slot is used by getnewvnode() */ 433 mp->mnt_stat.f_iosize = maxbcachebuf; 434 if (subtype) { 435 strlcat(mp->mnt_stat.f_fstypename, ".", MFSNAMELEN); 436 strlcat(mp->mnt_stat.f_fstypename, subtype, MFSNAMELEN); 437 } 438 memset(mp->mnt_stat.f_mntfromname, 0, MNAMELEN); 439 strlcpy(mp->mnt_stat.f_mntfromname, fspec, MNAMELEN); 440 mp->mnt_iosize_max = MAXPHYS; 441 442 /* Now handshaking with daemon */ 443 fuse_internal_send_init(data, td); 444 445 out: 446 if (err) { 447 FUSE_LOCK(); 448 if (data != NULL && data->mp == mp) { 449 /* 450 * Destroy device only if we acquired reference to 451 * it 452 */ 453 SDT_PROBE4(fusefs, , vfsops, mount_err, 454 "mount failed, destroy device", data, mp, err); 455 data->mp = NULL; 456 mp->mnt_data = NULL; 457 fdata_trydestroy(data); 458 } 459 FUSE_UNLOCK(); 460 dev_rel(fdev); 461 } 462 return err; 463 } 464 465 static int 466 fuse_vfsop_unmount(struct mount *mp, int mntflags) 467 { 468 int err = 0; 469 int flags = 0; 470 471 struct cdev *fdev; 472 struct fuse_data *data; 473 struct fuse_dispatcher fdi; 474 struct thread *td = curthread; 475 476 if (mntflags & MNT_FORCE) { 477 flags |= FORCECLOSE; 478 } 479 data = fuse_get_mpdata(mp); 480 if (!data) { 481 panic("no private data for mount point?"); 482 } 483 /* There is 1 extra root vnode reference (mp->mnt_data). */ 484 FUSE_LOCK(); 485 if (data->vroot != NULL) { 486 struct vnode *vroot = data->vroot; 487 488 data->vroot = NULL; 489 FUSE_UNLOCK(); 490 vrele(vroot); 491 } else 492 FUSE_UNLOCK(); 493 err = vflush(mp, 0, flags, td); 494 if (err) { 495 return err; 496 } 497 if (fdata_get_dead(data)) { 498 goto alreadydead; 499 } 500 if (fsess_isimpl(mp, FUSE_DESTROY)) { 501 fdisp_init(&fdi, 0); 502 fdisp_make(&fdi, FUSE_DESTROY, mp, 0, td, NULL); 503 504 (void)fdisp_wait_answ(&fdi); 505 fdisp_destroy(&fdi); 506 } 507 508 fdata_set_dead(data); 509 510 alreadydead: 511 FUSE_LOCK(); 512 data->mp = NULL; 513 fdev = data->fdev; 514 fdata_trydestroy(data); 515 FUSE_UNLOCK(); 516 517 MNT_ILOCK(mp); 518 mp->mnt_data = NULL; 519 MNT_IUNLOCK(mp); 520 521 dev_rel(fdev); 522 523 return 0; 524 } 525 526 SDT_PROBE_DEFINE1(fusefs, , vfsops, invalidate_without_export, 527 "struct mount*"); 528 static int 529 fuse_vfsop_vget(struct mount *mp, ino_t ino, int flags, struct vnode **vpp) 530 { 531 struct fuse_data *data = fuse_get_mpdata(mp); 532 uint64_t nodeid = ino; 533 struct thread *td = curthread; 534 struct fuse_dispatcher fdi; 535 struct fuse_entry_out *feo; 536 struct fuse_vnode_data *fvdat; 537 const char dot[] = "."; 538 off_t filesize; 539 enum vtype vtyp; 540 int error; 541 542 if (!(data->dataflags & FSESS_EXPORT_SUPPORT)) { 543 /* 544 * Unreachable unless you do something stupid, like export a 545 * nullfs mount of a fusefs file system. 546 */ 547 SDT_PROBE1(fusefs, , vfsops, invalidate_without_export, mp); 548 return (EOPNOTSUPP); 549 } 550 551 error = fuse_internal_get_cached_vnode(mp, ino, flags, vpp); 552 if (error || *vpp != NULL) 553 return error; 554 555 /* Do a LOOKUP, using nodeid as the parent and "." as filename */ 556 fdisp_init(&fdi, sizeof(dot)); 557 fdisp_make(&fdi, FUSE_LOOKUP, mp, nodeid, td, td->td_ucred); 558 memcpy(fdi.indata, dot, sizeof(dot)); 559 error = fdisp_wait_answ(&fdi); 560 561 if (error) 562 return error; 563 564 feo = (struct fuse_entry_out *)fdi.answ; 565 if (feo->nodeid == 0) { 566 /* zero nodeid means ENOENT and cache it */ 567 error = ENOENT; 568 goto out; 569 } 570 571 vtyp = IFTOVT(feo->attr.mode); 572 error = fuse_vnode_get(mp, feo, nodeid, NULL, vpp, NULL, vtyp); 573 if (error) 574 goto out; 575 filesize = feo->attr.size; 576 577 /* 578 * In the case where we are looking up a FUSE node represented by an 579 * existing cached vnode, and the true size reported by FUSE_LOOKUP 580 * doesn't match the vnode's cached size, then any cached writes beyond 581 * the file's current size are lost. 582 * 583 * We can get here: 584 * * following attribute cache expiration, or 585 * * due a bug in the daemon, or 586 */ 587 fvdat = VTOFUD(*vpp); 588 if (vnode_isreg(*vpp) && 589 filesize != fvdat->cached_attrs.va_size && 590 fvdat->flag & FN_SIZECHANGE) { 591 printf("%s: WB cache incoherent on %s!\n", __func__, 592 vnode_mount(*vpp)->mnt_stat.f_mntonname); 593 594 fvdat->flag &= ~FN_SIZECHANGE; 595 } 596 597 fuse_internal_cache_attrs(*vpp, &feo->attr, feo->attr_valid, 598 feo->attr_valid_nsec, NULL); 599 fuse_validity_2_bintime(feo->entry_valid, feo->entry_valid_nsec, 600 &fvdat->entry_cache_timeout); 601 out: 602 fdisp_destroy(&fdi); 603 return error; 604 } 605 606 static int 607 fuse_vfsop_root(struct mount *mp, int lkflags, struct vnode **vpp) 608 { 609 struct fuse_data *data = fuse_get_mpdata(mp); 610 int err = 0; 611 612 if (data->vroot != NULL) { 613 err = vget(data->vroot, lkflags); 614 if (err == 0) 615 *vpp = data->vroot; 616 } else { 617 err = fuse_vnode_get(mp, NULL, FUSE_ROOT_ID, NULL, vpp, NULL, 618 VDIR); 619 if (err == 0) { 620 FUSE_LOCK(); 621 MPASS(data->vroot == NULL || data->vroot == *vpp); 622 if (data->vroot == NULL) { 623 SDT_PROBE2(fusefs, , vfsops, trace, 1, 624 "new root vnode"); 625 data->vroot = *vpp; 626 FUSE_UNLOCK(); 627 vref(*vpp); 628 } else if (data->vroot != *vpp) { 629 SDT_PROBE2(fusefs, , vfsops, trace, 1, 630 "root vnode race"); 631 FUSE_UNLOCK(); 632 VOP_UNLOCK(*vpp); 633 vrele(*vpp); 634 vrecycle(*vpp); 635 *vpp = data->vroot; 636 } else 637 FUSE_UNLOCK(); 638 } 639 } 640 return err; 641 } 642 643 static int 644 fuse_vfsop_statfs(struct mount *mp, struct statfs *sbp) 645 { 646 struct fuse_dispatcher fdi; 647 int err = 0; 648 649 struct fuse_statfs_out *fsfo; 650 struct fuse_data *data; 651 652 data = fuse_get_mpdata(mp); 653 654 if (!(data->dataflags & FSESS_INITED)) 655 goto fake; 656 657 fdisp_init(&fdi, 0); 658 fdisp_make(&fdi, FUSE_STATFS, mp, FUSE_ROOT_ID, NULL, NULL); 659 err = fdisp_wait_answ(&fdi); 660 if (err) { 661 fdisp_destroy(&fdi); 662 if (err == ENOTCONN) { 663 /* 664 * We want to seem a legitimate fs even if the daemon 665 * is stiff dead... (so that, eg., we can still do path 666 * based unmounting after the daemon dies). 667 */ 668 goto fake; 669 } 670 return err; 671 } 672 fsfo = fdi.answ; 673 674 sbp->f_blocks = fsfo->st.blocks; 675 sbp->f_bfree = fsfo->st.bfree; 676 sbp->f_bavail = fsfo->st.bavail; 677 sbp->f_files = fsfo->st.files; 678 sbp->f_ffree = fsfo->st.ffree; /* cast from uint64_t to int64_t */ 679 sbp->f_namemax = fsfo->st.namelen; 680 sbp->f_bsize = fsfo->st.frsize; /* cast from uint32_t to uint64_t */ 681 682 fdisp_destroy(&fdi); 683 return 0; 684 685 fake: 686 sbp->f_blocks = 0; 687 sbp->f_bfree = 0; 688 sbp->f_bavail = 0; 689 sbp->f_files = 0; 690 sbp->f_ffree = 0; 691 sbp->f_namemax = 0; 692 sbp->f_bsize = S_BLKSIZE; 693 694 return 0; 695 } 696