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
fuse_getdevice(const char * fspec,struct thread * td,struct cdev ** fdevp)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
fuse_vfs_remount(struct mount * mp,struct thread * td,uint64_t mntopts,uint32_t max_read,int daemon_timeout)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
fuse_vfsop_fhtovp(struct mount * mp,struct fid * fhp,int flags,struct vnode ** vpp)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
fuse_vfsop_mount(struct mount * mp)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 size_t len;
307
308 struct cdev *fdev;
309 struct fuse_data *data = NULL;
310 struct thread *td;
311 struct file *fp, *fptmp;
312 char *fspec, *subtype;
313 struct vfsoptlist *opts;
314
315 subtype = NULL;
316 max_read = ~0;
317 err = 0;
318 mntopts = 0;
319 __mntopts = 0;
320 td = curthread;
321
322 /* Get the new options passed to mount */
323 opts = mp->mnt_optnew;
324
325 if (!opts)
326 return EINVAL;
327
328 /* `fspath' contains the mount point (eg. /mnt/fuse/sshfs); REQUIRED */
329 if (!vfs_getopts(opts, "fspath", &err))
330 return err;
331
332 /*
333 * With the help of underscored options the mount program
334 * can inform us from the flags it sets by default
335 */
336 FUSE_FLAGOPT(allow_other, FSESS_DAEMON_CAN_SPY);
337 FUSE_FLAGOPT(push_symlinks_in, FSESS_PUSH_SYMLINKS_IN);
338 FUSE_FLAGOPT(default_permissions, FSESS_DEFAULT_PERMISSIONS);
339 FUSE_FLAGOPT(intr, FSESS_INTR);
340
341 (void)vfs_scanopt(opts, "max_read=", "%u", &max_read);
342 if (vfs_scanopt(opts, "timeout=", "%u", &daemon_timeout) == 1) {
343 if (daemon_timeout < FUSE_MIN_DAEMON_TIMEOUT)
344 daemon_timeout = FUSE_MIN_DAEMON_TIMEOUT;
345 else if (daemon_timeout > FUSE_MAX_DAEMON_TIMEOUT)
346 daemon_timeout = FUSE_MAX_DAEMON_TIMEOUT;
347 } else {
348 daemon_timeout = FUSE_DEFAULT_DAEMON_TIMEOUT;
349 }
350 subtype = vfs_getopts(opts, "subtype=", &err);
351
352 SDT_PROBE1(fusefs, , vfsops, mntopts, mntopts);
353
354 if (mp->mnt_flag & MNT_UPDATE) {
355 return fuse_vfs_remount(mp, td, mntopts, max_read,
356 daemon_timeout);
357 }
358
359 /* `from' contains the device name (eg. /dev/fuse0); REQUIRED */
360 fspec = vfs_getopts(opts, "from", &err);
361 if (!fspec)
362 return err;
363
364 /* `fd' contains the filedescriptor for this session; REQUIRED */
365 if (vfs_scanopt(opts, "fd", "%d", &fd) != 1)
366 return EINVAL;
367
368 err = fuse_getdevice(fspec, td, &fdev);
369 if (err != 0)
370 return err;
371
372 err = fget(td, fd, &cap_read_rights, &fp);
373 if (err != 0) {
374 SDT_PROBE2(fusefs, , vfsops, trace, 1,
375 "invalid or not opened device");
376 goto out;
377 }
378 fptmp = td->td_fpop;
379 td->td_fpop = fp;
380 err = devfs_get_cdevpriv((void **)&data);
381 td->td_fpop = fptmp;
382 fdrop(fp, td);
383 FUSE_LOCK();
384
385 if (err != 0 || data == NULL) {
386 err = ENXIO;
387 SDT_PROBE4(fusefs, , vfsops, mount_err,
388 "invalid or not opened device", data, mp, err);
389 FUSE_UNLOCK();
390 goto out;
391 }
392 if (fdata_get_dead(data)) {
393 err = ENOTCONN;
394 SDT_PROBE4(fusefs, , vfsops, mount_err,
395 "device is dead during mount", data, mp, err);
396 FUSE_UNLOCK();
397 goto out;
398 }
399 /* Sanity + permission checks */
400 if (!data->daemoncred)
401 panic("fuse daemon found, but identity unknown");
402 if (mntopts & FSESS_DAEMON_CAN_SPY)
403 err = priv_check(td, PRIV_VFS_FUSE_ALLOWOTHER);
404 if (err == 0 && td->td_ucred->cr_uid != data->daemoncred->cr_uid)
405 /* are we allowed to do the first mount? */
406 err = priv_check(td, PRIV_VFS_FUSE_MOUNT_NONUSER);
407 if (err) {
408 FUSE_UNLOCK();
409 goto out;
410 }
411 data->ref++;
412 data->mp = mp;
413 data->dataflags |= mntopts;
414 data->max_read = max_read;
415 data->daemon_timeout = daemon_timeout;
416 data->mnt_flag = mp->mnt_flag & MNT_UPDATEMASK;
417 FUSE_UNLOCK();
418
419 vfs_getnewfsid(mp);
420 MNT_ILOCK(mp);
421 mp->mnt_data = data;
422 /*
423 * FUSE file systems can be either local or remote, but the kernel
424 * can't tell the difference.
425 */
426 mp->mnt_flag &= ~MNT_LOCAL;
427 mp->mnt_kern_flag |= MNTK_USES_BCACHE;
428 MNT_IUNLOCK(mp);
429 /* We need this here as this slot is used by getnewvnode() */
430 mp->mnt_stat.f_iosize = maxbcachebuf;
431 if (subtype) {
432 strlcat(mp->mnt_stat.f_fstypename, ".", MFSNAMELEN);
433 strlcat(mp->mnt_stat.f_fstypename, subtype, MFSNAMELEN);
434 }
435 copystr(fspec, mp->mnt_stat.f_mntfromname, MNAMELEN - 1, &len);
436 bzero(mp->mnt_stat.f_mntfromname + len, MNAMELEN - len);
437 mp->mnt_iosize_max = MAXPHYS;
438
439 /* Now handshaking with daemon */
440 fuse_internal_send_init(data, td);
441
442 out:
443 if (err) {
444 FUSE_LOCK();
445 if (data != NULL && data->mp == mp) {
446 /*
447 * Destroy device only if we acquired reference to
448 * it
449 */
450 SDT_PROBE4(fusefs, , vfsops, mount_err,
451 "mount failed, destroy device", data, mp, err);
452 data->mp = NULL;
453 mp->mnt_data = NULL;
454 fdata_trydestroy(data);
455 }
456 FUSE_UNLOCK();
457 dev_rel(fdev);
458 }
459 return err;
460 }
461
462 static int
fuse_vfsop_unmount(struct mount * mp,int mntflags)463 fuse_vfsop_unmount(struct mount *mp, int mntflags)
464 {
465 int err = 0;
466 int flags = 0;
467
468 struct cdev *fdev;
469 struct fuse_data *data;
470 struct fuse_dispatcher fdi;
471 struct thread *td = curthread;
472
473 if (mntflags & MNT_FORCE) {
474 flags |= FORCECLOSE;
475 }
476 data = fuse_get_mpdata(mp);
477 if (!data) {
478 panic("no private data for mount point?");
479 }
480 /* There is 1 extra root vnode reference (mp->mnt_data). */
481 FUSE_LOCK();
482 if (data->vroot != NULL) {
483 struct vnode *vroot = data->vroot;
484
485 data->vroot = NULL;
486 FUSE_UNLOCK();
487 vrele(vroot);
488 } else
489 FUSE_UNLOCK();
490 err = vflush(mp, 0, flags, td);
491 if (err) {
492 return err;
493 }
494 if (fdata_get_dead(data)) {
495 goto alreadydead;
496 }
497 if (fsess_isimpl(mp, FUSE_DESTROY)) {
498 fdisp_init(&fdi, 0);
499 fdisp_make(&fdi, FUSE_DESTROY, mp, 0, td, NULL);
500
501 (void)fdisp_wait_answ(&fdi);
502 fdisp_destroy(&fdi);
503 }
504
505 fdata_set_dead(data);
506
507 alreadydead:
508 FUSE_LOCK();
509 data->mp = NULL;
510 fdev = data->fdev;
511 fdata_trydestroy(data);
512 FUSE_UNLOCK();
513
514 MNT_ILOCK(mp);
515 mp->mnt_data = NULL;
516 MNT_IUNLOCK(mp);
517
518 dev_rel(fdev);
519
520 return 0;
521 }
522
523 SDT_PROBE_DEFINE1(fusefs, , vfsops, invalidate_without_export,
524 "struct mount*");
525 static int
fuse_vfsop_vget(struct mount * mp,ino_t ino,int flags,struct vnode ** vpp)526 fuse_vfsop_vget(struct mount *mp, ino_t ino, int flags, struct vnode **vpp)
527 {
528 struct fuse_data *data = fuse_get_mpdata(mp);
529 uint64_t nodeid = ino;
530 struct thread *td = curthread;
531 struct fuse_dispatcher fdi;
532 struct fuse_entry_out *feo;
533 struct fuse_vnode_data *fvdat;
534 const char dot[] = ".";
535 off_t filesize;
536 enum vtype vtyp;
537 int error;
538
539 if (!(data->dataflags & FSESS_EXPORT_SUPPORT)) {
540 /*
541 * Unreachable unless you do something stupid, like export a
542 * nullfs mount of a fusefs file system.
543 */
544 SDT_PROBE1(fusefs, , vfsops, invalidate_without_export, mp);
545 return (EOPNOTSUPP);
546 }
547
548 error = fuse_internal_get_cached_vnode(mp, ino, flags, vpp);
549 if (error || *vpp != NULL)
550 return error;
551
552 /* Do a LOOKUP, using nodeid as the parent and "." as filename */
553 fdisp_init(&fdi, sizeof(dot));
554 fdisp_make(&fdi, FUSE_LOOKUP, mp, nodeid, td, td->td_ucred);
555 memcpy(fdi.indata, dot, sizeof(dot));
556 error = fdisp_wait_answ(&fdi);
557
558 if (error)
559 return error;
560
561 feo = (struct fuse_entry_out *)fdi.answ;
562 if (feo->nodeid == 0) {
563 /* zero nodeid means ENOENT and cache it */
564 error = ENOENT;
565 goto out;
566 }
567
568 vtyp = IFTOVT(feo->attr.mode);
569 error = fuse_vnode_get(mp, feo, nodeid, NULL, vpp, NULL, vtyp);
570 if (error)
571 goto out;
572 filesize = feo->attr.size;
573
574 /*
575 * In the case where we are looking up a FUSE node represented by an
576 * existing cached vnode, and the true size reported by FUSE_LOOKUP
577 * doesn't match the vnode's cached size, then any cached writes beyond
578 * the file's current size are lost.
579 *
580 * We can get here:
581 * * following attribute cache expiration, or
582 * * due a bug in the daemon, or
583 */
584 fvdat = VTOFUD(*vpp);
585 if (vnode_isreg(*vpp) &&
586 filesize != fvdat->cached_attrs.va_size &&
587 fvdat->flag & FN_SIZECHANGE) {
588 printf("%s: WB cache incoherent on %s!\n", __func__,
589 vnode_mount(*vpp)->mnt_stat.f_mntonname);
590
591 fvdat->flag &= ~FN_SIZECHANGE;
592 }
593
594 fuse_internal_cache_attrs(*vpp, &feo->attr, feo->attr_valid,
595 feo->attr_valid_nsec, NULL);
596 fuse_validity_2_bintime(feo->entry_valid, feo->entry_valid_nsec,
597 &fvdat->entry_cache_timeout);
598 out:
599 fdisp_destroy(&fdi);
600 return error;
601 }
602
603 static int
fuse_vfsop_root(struct mount * mp,int lkflags,struct vnode ** vpp)604 fuse_vfsop_root(struct mount *mp, int lkflags, struct vnode **vpp)
605 {
606 struct fuse_data *data = fuse_get_mpdata(mp);
607 int err = 0;
608
609 if (data->vroot != NULL) {
610 err = vget(data->vroot, lkflags, curthread);
611 if (err == 0)
612 *vpp = data->vroot;
613 } else {
614 err = fuse_vnode_get(mp, NULL, FUSE_ROOT_ID, NULL, vpp, NULL,
615 VDIR);
616 if (err == 0) {
617 FUSE_LOCK();
618 MPASS(data->vroot == NULL || data->vroot == *vpp);
619 if (data->vroot == NULL) {
620 SDT_PROBE2(fusefs, , vfsops, trace, 1,
621 "new root vnode");
622 data->vroot = *vpp;
623 FUSE_UNLOCK();
624 vref(*vpp);
625 } else if (data->vroot != *vpp) {
626 SDT_PROBE2(fusefs, , vfsops, trace, 1,
627 "root vnode race");
628 FUSE_UNLOCK();
629 VOP_UNLOCK(*vpp, 0);
630 vrele(*vpp);
631 vrecycle(*vpp);
632 *vpp = data->vroot;
633 } else
634 FUSE_UNLOCK();
635 }
636 }
637 return err;
638 }
639
640 static int
fuse_vfsop_statfs(struct mount * mp,struct statfs * sbp)641 fuse_vfsop_statfs(struct mount *mp, struct statfs *sbp)
642 {
643 struct fuse_dispatcher fdi;
644 int err = 0;
645
646 struct fuse_statfs_out *fsfo;
647 struct fuse_data *data;
648
649 data = fuse_get_mpdata(mp);
650
651 if (!(data->dataflags & FSESS_INITED))
652 goto fake;
653
654 fdisp_init(&fdi, 0);
655 fdisp_make(&fdi, FUSE_STATFS, mp, FUSE_ROOT_ID, NULL, NULL);
656 err = fdisp_wait_answ(&fdi);
657 if (err) {
658 fdisp_destroy(&fdi);
659 if (err == ENOTCONN) {
660 /*
661 * We want to seem a legitimate fs even if the daemon
662 * is stiff dead... (so that, eg., we can still do path
663 * based unmounting after the daemon dies).
664 */
665 goto fake;
666 }
667 return err;
668 }
669 fsfo = fdi.answ;
670
671 sbp->f_blocks = fsfo->st.blocks;
672 sbp->f_bfree = fsfo->st.bfree;
673 sbp->f_bavail = fsfo->st.bavail;
674 sbp->f_files = fsfo->st.files;
675 sbp->f_ffree = fsfo->st.ffree; /* cast from uint64_t to int64_t */
676 sbp->f_namemax = fsfo->st.namelen;
677 sbp->f_bsize = fsfo->st.frsize; /* cast from uint32_t to uint64_t */
678
679 fdisp_destroy(&fdi);
680 return 0;
681
682 fake:
683 sbp->f_blocks = 0;
684 sbp->f_bfree = 0;
685 sbp->f_bavail = 0;
686 sbp->f_files = 0;
687 sbp->f_ffree = 0;
688 sbp->f_namemax = 0;
689 sbp->f_bsize = S_BLKSIZE;
690
691 return 0;
692 }
693