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/types.h>
67 #include <sys/systm.h>
68 #include <sys/counter.h>
69 #include <sys/module.h>
70 #include <sys/errno.h>
71 #include <sys/param.h>
72 #include <sys/kernel.h>
73 #include <sys/conf.h>
74 #include <sys/uio.h>
75 #include <sys/malloc.h>
76 #include <sys/queue.h>
77 #include <sys/lock.h>
78 #include <sys/sx.h>
79 #include <sys/mutex.h>
80 #include <sys/proc.h>
81 #include <sys/vnode.h>
82 #include <sys/namei.h>
83 #include <sys/mount.h>
84 #include <sys/sysctl.h>
85 #include <sys/fcntl.h>
86 #include <sys/priv.h>
87 #include <sys/buf.h>
88 #include <security/mac/mac_framework.h>
89 #include <vm/vm.h>
90 #include <vm/vm_extern.h>
91
92 #include "fuse.h"
93 #include "fuse_node.h"
94 #include "fuse_internal.h"
95 #include "fuse_io.h"
96 #include "fuse_ipc.h"
97
98 SDT_PROVIDER_DECLARE(fusefs);
99 /*
100 * Fuse trace probe:
101 * arg0: verbosity. Higher numbers give more verbose messages
102 * arg1: Textual message
103 */
104 SDT_PROBE_DEFINE2(fusefs, , node, trace, "int", "char*");
105
106 MALLOC_DEFINE(M_FUSEVN, "fuse_vnode", "fuse vnode private data");
107
108 static int sysctl_fuse_cache_mode(SYSCTL_HANDLER_ARGS);
109
110 static counter_u64_t fuse_node_count;
111
112 SYSCTL_COUNTER_U64(_vfs_fusefs_stats, OID_AUTO, node_count, CTLFLAG_RD,
113 &fuse_node_count, "Count of FUSE vnodes");
114
115 int fuse_data_cache_mode = FUSE_CACHE_WT;
116
117 /*
118 * DEPRECATED
119 * This sysctl is no longer needed as of fuse protocol 7.23. Individual
120 * servers can select the cache behavior they need for each mountpoint:
121 * - writethrough: the default
122 * - writeback: set FUSE_WRITEBACK_CACHE in fuse_init_out.flags
123 * - uncached: set FOPEN_DIRECT_IO for every file
124 * The sysctl is retained primarily for use by jails supporting older FUSE
125 * protocols. It may be removed entirely once FreeBSD 11.3 and 12.0 are EOL.
126 */
127 SYSCTL_PROC(_vfs_fusefs, OID_AUTO, data_cache_mode, CTLTYPE_INT|CTLFLAG_RW,
128 &fuse_data_cache_mode, 0, sysctl_fuse_cache_mode, "I",
129 "Zero: disable caching of FUSE file data; One: write-through caching "
130 "(default); Two: write-back caching (generally unsafe)");
131
132 static int
sysctl_fuse_cache_mode(SYSCTL_HANDLER_ARGS)133 sysctl_fuse_cache_mode(SYSCTL_HANDLER_ARGS)
134 {
135 int val, error;
136
137 val = *(int *)arg1;
138 error = sysctl_handle_int(oidp, &val, 0, req);
139 if (error || !req->newptr)
140 return (error);
141
142 switch (val) {
143 case FUSE_CACHE_UC:
144 case FUSE_CACHE_WT:
145 case FUSE_CACHE_WB:
146 *(int *)arg1 = val;
147 break;
148 default:
149 return (EDOM);
150 }
151 return (0);
152 }
153
154 static void
fuse_vnode_init(struct vnode * vp,struct fuse_vnode_data * fvdat,uint64_t nodeid,enum vtype vtyp)155 fuse_vnode_init(struct vnode *vp, struct fuse_vnode_data *fvdat,
156 uint64_t nodeid, enum vtype vtyp)
157 {
158 fvdat->nid = nodeid;
159 LIST_INIT(&fvdat->handles);
160 vattr_null(&fvdat->cached_attrs);
161 if (nodeid == FUSE_ROOT_ID) {
162 vp->v_vflag |= VV_ROOT;
163 }
164 vp->v_type = vtyp;
165 vp->v_data = fvdat;
166
167 counter_u64_add(fuse_node_count, 1);
168 }
169
170 void
fuse_vnode_destroy(struct vnode * vp)171 fuse_vnode_destroy(struct vnode *vp)
172 {
173 struct fuse_vnode_data *fvdat = vp->v_data;
174
175 vp->v_data = NULL;
176 KASSERT(LIST_EMPTY(&fvdat->handles),
177 ("Destroying fuse vnode with open files!"));
178 free(fvdat, M_FUSEVN);
179
180 counter_u64_add(fuse_node_count, -1);
181 }
182
183 int
fuse_vnode_cmp(struct vnode * vp,void * nidp)184 fuse_vnode_cmp(struct vnode *vp, void *nidp)
185 {
186 return (VTOI(vp) != *((uint64_t *)nidp));
187 }
188
189 SDT_PROBE_DEFINE3(fusefs, , node, stale_vnode, "struct vnode*", "enum vtype",
190 "uint64_t");
191 static int
fuse_vnode_alloc(struct mount * mp,struct thread * td,uint64_t nodeid,enum vtype vtyp,struct vnode ** vpp)192 fuse_vnode_alloc(struct mount *mp,
193 struct thread *td,
194 uint64_t nodeid,
195 enum vtype vtyp,
196 struct vnode **vpp)
197 {
198 struct fuse_data *data;
199 struct fuse_vnode_data *fvdat;
200 struct vnode *vp2;
201 int err = 0;
202
203 data = fuse_get_mpdata(mp);
204 if (vtyp == VNON) {
205 return EINVAL;
206 }
207 *vpp = NULL;
208 err = vfs_hash_get(mp, fuse_vnode_hash(nodeid), LK_EXCLUSIVE, td, vpp,
209 fuse_vnode_cmp, &nodeid);
210 if (err)
211 return (err);
212
213 if (*vpp) {
214 if ((*vpp)->v_type != vtyp) {
215 /*
216 * STALE vnode! This probably indicates a buggy
217 * server, but it could also be the result of a race
218 * between FUSE_LOOKUP and another client's
219 * FUSE_UNLINK/FUSE_CREATE
220 */
221 SDT_PROBE3(fusefs, , node, stale_vnode, *vpp, vtyp,
222 nodeid);
223 fuse_internal_vnode_disappear(*vpp);
224 lockmgr((*vpp)->v_vnlock, LK_RELEASE, NULL);
225 *vpp = NULL;
226 return (EAGAIN);
227 }
228 MPASS((*vpp)->v_data != NULL);
229 MPASS(VTOFUD(*vpp)->nid == nodeid);
230 SDT_PROBE2(fusefs, , node, trace, 1, "vnode taken from hash");
231 return (0);
232 }
233 fvdat = malloc(sizeof(*fvdat), M_FUSEVN, M_WAITOK | M_ZERO);
234 switch (vtyp) {
235 case VFIFO:
236 err = getnewvnode("fuse", mp, &fuse_fifoops, vpp);
237 break;
238 default:
239 err = getnewvnode("fuse", mp, &fuse_vnops, vpp);
240 break;
241 }
242 if (err) {
243 free(fvdat, M_FUSEVN);
244 return (err);
245 }
246 lockmgr((*vpp)->v_vnlock, LK_EXCLUSIVE, NULL);
247 fuse_vnode_init(*vpp, fvdat, nodeid, vtyp);
248 err = insmntque(*vpp, mp);
249 ASSERT_VOP_ELOCKED(*vpp, "fuse_vnode_alloc");
250 if (err) {
251 lockmgr((*vpp)->v_vnlock, LK_RELEASE, NULL);
252 free(fvdat, M_FUSEVN);
253 *vpp = NULL;
254 return (err);
255 }
256 /* Disallow async reads for fifos because UFS does. I don't know why */
257 if (data->dataflags & FSESS_ASYNC_READ && vtyp != VFIFO)
258 VN_LOCK_ASHARE(*vpp);
259
260 err = vfs_hash_insert(*vpp, fuse_vnode_hash(nodeid), LK_EXCLUSIVE,
261 td, &vp2, fuse_vnode_cmp, &nodeid);
262 if (err) {
263 lockmgr((*vpp)->v_vnlock, LK_RELEASE, NULL);
264 free(fvdat, M_FUSEVN);
265 *vpp = NULL;
266 return (err);
267 }
268 if (vp2 != NULL) {
269 *vpp = vp2;
270 return (0);
271 }
272
273 ASSERT_VOP_ELOCKED(*vpp, "fuse_vnode_alloc");
274
275 return (0);
276 }
277
278 int
fuse_vnode_get(struct mount * mp,struct fuse_entry_out * feo,uint64_t nodeid,struct vnode * dvp,struct vnode ** vpp,struct componentname * cnp,enum vtype vtyp)279 fuse_vnode_get(struct mount *mp,
280 struct fuse_entry_out *feo,
281 uint64_t nodeid,
282 struct vnode *dvp,
283 struct vnode **vpp,
284 struct componentname *cnp,
285 enum vtype vtyp)
286 {
287 struct thread *td = (cnp != NULL ? cnp->cn_thread : curthread);
288 /*
289 * feo should only be NULL for the root directory, which (when libfuse
290 * is used) always has generation 0
291 */
292 uint64_t generation = feo ? feo->generation : 0;
293 int err = 0;
294
295 err = fuse_vnode_alloc(mp, td, nodeid, vtyp, vpp);
296 if (err) {
297 return err;
298 }
299 if (dvp != NULL) {
300 MPASS(cnp && (cnp->cn_flags & ISDOTDOT) == 0);
301 MPASS(cnp &&
302 !(cnp->cn_namelen == 1 && cnp->cn_nameptr[0] == '.'));
303 fuse_vnode_setparent(*vpp, dvp);
304 }
305 if (dvp != NULL && cnp != NULL && (cnp->cn_flags & MAKEENTRY) != 0 &&
306 feo != NULL &&
307 (feo->entry_valid != 0 || feo->entry_valid_nsec != 0)) {
308 struct timespec timeout;
309
310 ASSERT_VOP_LOCKED(*vpp, "fuse_vnode_get");
311 ASSERT_VOP_LOCKED(dvp, "fuse_vnode_get");
312
313 fuse_validity_2_timespec(feo, &timeout);
314 cache_enter_time(dvp, *vpp, cnp, &timeout, NULL);
315 }
316
317 VTOFUD(*vpp)->generation = generation;
318 /*
319 * In userland, libfuse uses cached lookups for dot and dotdot entries,
320 * thus it does not really bump the nlookup counter for forget.
321 * Follow the same semantic and avoid the bump in order to keep
322 * nlookup counters consistent.
323 */
324 if (cnp == NULL || ((cnp->cn_flags & ISDOTDOT) == 0 &&
325 (cnp->cn_namelen != 1 || cnp->cn_nameptr[0] != '.')))
326 VTOFUD(*vpp)->nlookup++;
327
328 return 0;
329 }
330
331 /*
332 * Called for every fusefs vnode open to initialize the vnode (not
333 * fuse_filehandle) for use
334 */
335 void
fuse_vnode_open(struct vnode * vp,int32_t fuse_open_flags,struct thread * td)336 fuse_vnode_open(struct vnode *vp, int32_t fuse_open_flags, struct thread *td)
337 {
338 if (vnode_vtype(vp) == VREG)
339 vnode_create_vobject(vp, 0, td);
340 }
341
342 int
fuse_vnode_savesize(struct vnode * vp,struct ucred * cred,pid_t pid)343 fuse_vnode_savesize(struct vnode *vp, struct ucred *cred, pid_t pid)
344 {
345 struct fuse_vnode_data *fvdat = VTOFUD(vp);
346 struct thread *td = curthread;
347 struct fuse_filehandle *fufh = NULL;
348 struct fuse_dispatcher fdi;
349 struct fuse_setattr_in *fsai;
350 int err = 0;
351
352 ASSERT_VOP_ELOCKED(vp, "fuse_io_extend");
353
354 if (fuse_isdeadfs(vp)) {
355 return EBADF;
356 }
357 if (vnode_vtype(vp) == VDIR) {
358 return EISDIR;
359 }
360 if (vfs_isrdonly(vnode_mount(vp))) {
361 return EROFS;
362 }
363 if (cred == NULL) {
364 cred = td->td_ucred;
365 }
366 fdisp_init(&fdi, sizeof(*fsai));
367 fdisp_make_vp(&fdi, FUSE_SETATTR, vp, td, cred);
368 fsai = fdi.indata;
369 fsai->valid = 0;
370
371 /* Truncate to a new value. */
372 MPASS((fvdat->flag & FN_SIZECHANGE) != 0);
373 fsai->size = fvdat->cached_attrs.va_size;
374 fsai->valid |= FATTR_SIZE;
375
376 fuse_filehandle_getrw(vp, FWRITE, &fufh, cred, pid);
377 if (fufh) {
378 fsai->fh = fufh->fh_id;
379 fsai->valid |= FATTR_FH;
380 }
381 err = fdisp_wait_answ(&fdi);
382 fdisp_destroy(&fdi);
383 if (err == 0)
384 fvdat->flag &= ~FN_SIZECHANGE;
385
386 return err;
387 }
388
389 /*
390 * Adjust the vnode's size to a new value, such as that provided by
391 * FUSE_GETATTR.
392 */
393 int
fuse_vnode_setsize(struct vnode * vp,off_t newsize)394 fuse_vnode_setsize(struct vnode *vp, off_t newsize)
395 {
396 struct fuse_vnode_data *fvdat = VTOFUD(vp);
397 struct vattr *attrs;
398 off_t oldsize;
399 size_t iosize;
400 struct buf *bp = NULL;
401 int err = 0;
402
403 ASSERT_VOP_ELOCKED(vp, "fuse_vnode_setsize");
404
405 iosize = fuse_iosize(vp);
406 oldsize = fvdat->cached_attrs.va_size;
407 fvdat->cached_attrs.va_size = newsize;
408 if ((attrs = VTOVA(vp)) != NULL)
409 attrs->va_size = newsize;
410
411 if (newsize < oldsize) {
412 daddr_t lbn;
413
414 err = vtruncbuf(vp, newsize, fuse_iosize(vp));
415 if (err)
416 goto out;
417 if (newsize % iosize == 0)
418 goto out;
419 /*
420 * Zero the contents of the last partial block.
421 * Sure seems like vtruncbuf should do this for us.
422 */
423
424 lbn = newsize / iosize;
425 bp = getblk(vp, lbn, iosize, PCATCH, 0, 0);
426 if (!bp) {
427 err = EINTR;
428 goto out;
429 }
430 if (!(bp->b_flags & B_CACHE))
431 goto out; /* Nothing to do */
432 MPASS(bp->b_flags & B_VMIO);
433 vfs_bio_clrbuf(bp);
434 bp->b_dirtyend = MIN(bp->b_dirtyend, newsize - lbn * iosize);
435 }
436 out:
437 if (bp)
438 brelse(bp);
439 vnode_pager_setsize(vp, newsize);
440 return err;
441 }
442
443 /* Get the current, possibly dirty, size of the file */
444 int
fuse_vnode_size(struct vnode * vp,off_t * filesize,struct ucred * cred,struct thread * td)445 fuse_vnode_size(struct vnode *vp, off_t *filesize, struct ucred *cred,
446 struct thread *td)
447 {
448 struct fuse_vnode_data *fvdat = VTOFUD(vp);
449 int error = 0;
450
451 if (!(fvdat->flag & FN_SIZECHANGE) &&
452 (VTOVA(vp) == NULL || fvdat->cached_attrs.va_size == VNOVAL))
453 error = fuse_internal_do_getattr(vp, NULL, cred, td);
454
455 if (!error)
456 *filesize = fvdat->cached_attrs.va_size;
457
458 return error;
459 }
460
461 void
fuse_vnode_undirty_cached_timestamps(struct vnode * vp)462 fuse_vnode_undirty_cached_timestamps(struct vnode *vp)
463 {
464 struct fuse_vnode_data *fvdat = VTOFUD(vp);
465
466 fvdat->flag &= ~(FN_MTIMECHANGE | FN_CTIMECHANGE);
467 }
468
469 /* Update a fuse file's cached timestamps */
470 void
fuse_vnode_update(struct vnode * vp,int flags)471 fuse_vnode_update(struct vnode *vp, int flags)
472 {
473 struct fuse_vnode_data *fvdat = VTOFUD(vp);
474 struct fuse_data *data = fuse_get_mpdata(vnode_mount(vp));
475 struct timespec ts;
476
477 vfs_timestamp(&ts);
478
479 if (data->time_gran > 1)
480 ts.tv_nsec = rounddown(ts.tv_nsec, data->time_gran);
481
482 if (flags & FN_MTIMECHANGE)
483 fvdat->cached_attrs.va_mtime = ts;
484 if (flags & FN_CTIMECHANGE)
485 fvdat->cached_attrs.va_ctime = ts;
486
487 fvdat->flag |= flags;
488 }
489
490 void
fuse_node_init(void)491 fuse_node_init(void)
492 {
493 fuse_node_count = counter_u64_alloc(M_WAITOK);
494 }
495
496 void
fuse_node_destroy(void)497 fuse_node_destroy(void)
498 {
499 counter_u64_free(fuse_node_count);
500 }
501