xref: /freebsd/sys/fs/fuse/fuse_node.c (revision 85732ac8)
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  * Redistribution and use in source and binary forms, with or without
37  * modification, are permitted provided that the following conditions
38  * are met:
39  * 1. Redistributions of source code must retain the above copyright
40  *    notice, this list of conditions and the following disclaimer.
41  * 2. Redistributions in binary form must reproduce the above copyright
42  *    notice, this list of conditions and the following disclaimer in the
43  *    documentation and/or other materials provided with the distribution.
44  *
45  * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
46  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
47  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
48  * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
49  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
50  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
51  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
52  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
53  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
54  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
55  * SUCH DAMAGE.
56  */
57 
58 #include <sys/cdefs.h>
59 __FBSDID("$FreeBSD$");
60 
61 #include <sys/types.h>
62 #include <sys/module.h>
63 #include <sys/systm.h>
64 #include <sys/errno.h>
65 #include <sys/param.h>
66 #include <sys/kernel.h>
67 #include <sys/conf.h>
68 #include <sys/uio.h>
69 #include <sys/malloc.h>
70 #include <sys/queue.h>
71 #include <sys/lock.h>
72 #include <sys/sx.h>
73 #include <sys/mutex.h>
74 #include <sys/proc.h>
75 #include <sys/vnode.h>
76 #include <sys/namei.h>
77 #include <sys/mount.h>
78 #include <sys/sysctl.h>
79 #include <sys/fcntl.h>
80 #include <sys/fnv_hash.h>
81 #include <sys/priv.h>
82 #include <security/mac/mac_framework.h>
83 #include <vm/vm.h>
84 #include <vm/vm_extern.h>
85 
86 #include "fuse.h"
87 #include "fuse_node.h"
88 #include "fuse_internal.h"
89 #include "fuse_io.h"
90 #include "fuse_ipc.h"
91 
92 #define FUSE_DEBUG_MODULE VNOPS
93 #include "fuse_debug.h"
94 
95 MALLOC_DEFINE(M_FUSEVN, "fuse_vnode", "fuse vnode private data");
96 
97 static int fuse_node_count = 0;
98 
99 SYSCTL_INT(_vfs_fuse, OID_AUTO, node_count, CTLFLAG_RD,
100     &fuse_node_count, 0, "Count of FUSE vnodes");
101 
102 int	fuse_data_cache_enable = 1;
103 
104 SYSCTL_INT(_vfs_fuse, OID_AUTO, data_cache_enable, CTLFLAG_RW,
105     &fuse_data_cache_enable, 0,
106     "enable caching of FUSE file data (including dirty data)");
107 
108 int	fuse_data_cache_invalidate = 0;
109 
110 SYSCTL_INT(_vfs_fuse, OID_AUTO, data_cache_invalidate, CTLFLAG_RW,
111     &fuse_data_cache_invalidate, 0,
112     "If non-zero, discard cached clean file data when there are no active file"
113     " users");
114 
115 int	fuse_mmap_enable = 1;
116 
117 SYSCTL_INT(_vfs_fuse, OID_AUTO, mmap_enable, CTLFLAG_RW,
118     &fuse_mmap_enable, 0,
119     "If non-zero, and data_cache_enable is also non-zero, enable mmap(2) of "
120     "FUSE files");
121 
122 int	fuse_refresh_size = 0;
123 
124 SYSCTL_INT(_vfs_fuse, OID_AUTO, refresh_size, CTLFLAG_RW,
125     &fuse_refresh_size, 0,
126     "If non-zero, and no dirty file extension data is buffered, fetch file "
127     "size before write operations");
128 
129 int	fuse_sync_resize = 1;
130 
131 SYSCTL_INT(_vfs_fuse, OID_AUTO, sync_resize, CTLFLAG_RW,
132     &fuse_sync_resize, 0,
133     "If a cached write extended a file, inform FUSE filesystem of the changed"
134     "size immediately subsequent to the issued writes");
135 
136 int	fuse_fix_broken_io = 0;
137 
138 SYSCTL_INT(_vfs_fuse, OID_AUTO, fix_broken_io, CTLFLAG_RW,
139     &fuse_fix_broken_io, 0,
140     "If non-zero, print a diagnostic warning if a userspace filesystem returns"
141     " EIO on reads of recently extended portions of files");
142 
143 static void
144 fuse_vnode_init(struct vnode *vp, struct fuse_vnode_data *fvdat,
145     uint64_t nodeid, enum vtype vtyp)
146 {
147 	int i;
148 
149 	fvdat->nid = nodeid;
150 	if (nodeid == FUSE_ROOT_ID) {
151 		vp->v_vflag |= VV_ROOT;
152 	}
153 	vp->v_type = vtyp;
154 	vp->v_data = fvdat;
155 
156 	for (i = 0; i < FUFH_MAXTYPE; i++)
157 		fvdat->fufh[i].fh_type = FUFH_INVALID;
158 
159 	atomic_add_acq_int(&fuse_node_count, 1);
160 }
161 
162 void
163 fuse_vnode_destroy(struct vnode *vp)
164 {
165 	struct fuse_vnode_data *fvdat = vp->v_data;
166 
167 	vp->v_data = NULL;
168 	free(fvdat, M_FUSEVN);
169 
170 	atomic_subtract_acq_int(&fuse_node_count, 1);
171 }
172 
173 static int
174 fuse_vnode_cmp(struct vnode *vp, void *nidp)
175 {
176 	return (VTOI(vp) != *((uint64_t *)nidp));
177 }
178 
179 static uint32_t __inline
180 fuse_vnode_hash(uint64_t id)
181 {
182 	return (fnv_32_buf(&id, sizeof(id), FNV1_32_INIT));
183 }
184 
185 static int
186 fuse_vnode_alloc(struct mount *mp,
187     struct thread *td,
188     uint64_t nodeid,
189     enum vtype vtyp,
190     struct vnode **vpp)
191 {
192 	struct fuse_vnode_data *fvdat;
193 	struct vnode *vp2;
194 	int err = 0;
195 
196 	FS_DEBUG("been asked for vno #%ju\n", (uintmax_t)nodeid);
197 
198 	if (vtyp == VNON) {
199 		return EINVAL;
200 	}
201 	*vpp = NULL;
202 	err = vfs_hash_get(mp, fuse_vnode_hash(nodeid), LK_EXCLUSIVE, td, vpp,
203 	    fuse_vnode_cmp, &nodeid);
204 	if (err)
205 		return (err);
206 
207 	if (*vpp) {
208 		MPASS((*vpp)->v_type == vtyp && (*vpp)->v_data != NULL);
209 		FS_DEBUG("vnode taken from hash\n");
210 		return (0);
211 	}
212 	fvdat = malloc(sizeof(*fvdat), M_FUSEVN, M_WAITOK | M_ZERO);
213 	err = getnewvnode("fuse", mp, &fuse_vnops, vpp);
214 	if (err) {
215 		free(fvdat, M_FUSEVN);
216 		return (err);
217 	}
218 	lockmgr((*vpp)->v_vnlock, LK_EXCLUSIVE, NULL);
219 	fuse_vnode_init(*vpp, fvdat, nodeid, vtyp);
220 	err = insmntque(*vpp, mp);
221 	ASSERT_VOP_ELOCKED(*vpp, "fuse_vnode_alloc");
222 	if (err) {
223 		free(fvdat, M_FUSEVN);
224 		*vpp = NULL;
225 		return (err);
226 	}
227 	err = vfs_hash_insert(*vpp, fuse_vnode_hash(nodeid), LK_EXCLUSIVE,
228 	    td, &vp2, fuse_vnode_cmp, &nodeid);
229 	if (err)
230 		return (err);
231 	if (vp2 != NULL) {
232 		*vpp = vp2;
233 		return (0);
234 	}
235 
236 	ASSERT_VOP_ELOCKED(*vpp, "fuse_vnode_alloc");
237 
238 	return (0);
239 }
240 
241 int
242 fuse_vnode_get(struct mount *mp,
243     uint64_t nodeid,
244     struct vnode *dvp,
245     struct vnode **vpp,
246     struct componentname *cnp,
247     enum vtype vtyp)
248 {
249 	struct thread *td = (cnp != NULL ? cnp->cn_thread : curthread);
250 	int err = 0;
251 
252 	debug_printf("dvp=%p\n", dvp);
253 
254 	err = fuse_vnode_alloc(mp, td, nodeid, vtyp, vpp);
255 	if (err) {
256 		return err;
257 	}
258 	if (dvp != NULL) {
259 		MPASS((cnp->cn_flags & ISDOTDOT) == 0);
260 		MPASS(!(cnp->cn_namelen == 1 && cnp->cn_nameptr[0] == '.'));
261 		fuse_vnode_setparent(*vpp, dvp);
262 	}
263 	if (dvp != NULL && cnp != NULL && (cnp->cn_flags & MAKEENTRY) != 0) {
264 		ASSERT_VOP_LOCKED(*vpp, "fuse_vnode_get");
265 		ASSERT_VOP_LOCKED(dvp, "fuse_vnode_get");
266 		cache_enter(dvp, *vpp, cnp);
267 	}
268 
269 	/*
270 	 * In userland, libfuse uses cached lookups for dot and dotdot entries,
271 	 * thus it does not really bump the nlookup counter for forget.
272 	 * Follow the same semantic and avoid tu bump it in order to keep
273 	 * nlookup counters consistent.
274 	 */
275 	if (cnp == NULL || ((cnp->cn_flags & ISDOTDOT) == 0 &&
276 	    (cnp->cn_namelen != 1 || cnp->cn_nameptr[0] != '.')))
277 		VTOFUD(*vpp)->nlookup++;
278 
279 	return 0;
280 }
281 
282 void
283 fuse_vnode_open(struct vnode *vp, int32_t fuse_open_flags, struct thread *td)
284 {
285 	/*
286 	 * Funcation is called for every vnode open.
287 	 * Merge fuse_open_flags it may be 0
288 	 */
289 	/*
290 	 * Ideally speaking, direct io should be enabled on
291 	 * fd's but do not see of any way of providing that
292 	 * this implementation.
293 	 *
294 	 * Also cannot think of a reason why would two
295 	 * different fd's on same vnode would like
296 	 * have DIRECT_IO turned on and off. But linux
297 	 * based implementation works on an fd not an
298 	 * inode and provides such a feature.
299 	 *
300 	 * XXXIP: Handle fd based DIRECT_IO
301 	 */
302 	if (fuse_open_flags & FOPEN_DIRECT_IO) {
303 		ASSERT_VOP_ELOCKED(vp, __func__);
304 		VTOFUD(vp)->flag |= FN_DIRECTIO;
305 		fuse_io_invalbuf(vp, td);
306 	} else {
307 		if ((fuse_open_flags & FOPEN_KEEP_CACHE) == 0)
308 			fuse_io_invalbuf(vp, td);
309 	        VTOFUD(vp)->flag &= ~FN_DIRECTIO;
310 	}
311 
312 	if (vnode_vtype(vp) == VREG) {
313 		/* XXXIP prevent getattr, by using cached node size */
314 		vnode_create_vobject(vp, 0, td);
315 	}
316 }
317 
318 int
319 fuse_vnode_savesize(struct vnode *vp, struct ucred *cred)
320 {
321 	struct fuse_vnode_data *fvdat = VTOFUD(vp);
322 	struct thread *td = curthread;
323 	struct fuse_filehandle *fufh = NULL;
324 	struct fuse_dispatcher fdi;
325 	struct fuse_setattr_in *fsai;
326 	int err = 0;
327 
328 	FS_DEBUG("inode=%ju size=%ju\n", (uintmax_t)VTOI(vp),
329 	    (uintmax_t)fvdat->filesize);
330 	ASSERT_VOP_ELOCKED(vp, "fuse_io_extend");
331 
332 	if (fuse_isdeadfs(vp)) {
333 		return EBADF;
334 	}
335 	if (vnode_vtype(vp) == VDIR) {
336 		return EISDIR;
337 	}
338 	if (vfs_isrdonly(vnode_mount(vp))) {
339 		return EROFS;
340 	}
341 	if (cred == NULL) {
342 		cred = td->td_ucred;
343 	}
344 	fdisp_init(&fdi, sizeof(*fsai));
345 	fdisp_make_vp(&fdi, FUSE_SETATTR, vp, td, cred);
346 	fsai = fdi.indata;
347 	fsai->valid = 0;
348 
349 	/* Truncate to a new value. */
350 	fsai->size = fvdat->filesize;
351 	fsai->valid |= FATTR_SIZE;
352 
353 	fuse_filehandle_getrw(vp, FUFH_WRONLY, &fufh);
354 	if (fufh) {
355 		fsai->fh = fufh->fh_id;
356 		fsai->valid |= FATTR_FH;
357 	}
358 	err = fdisp_wait_answ(&fdi);
359 	fdisp_destroy(&fdi);
360 	if (err == 0)
361 		fvdat->flag &= ~FN_SIZECHANGE;
362 
363 	return err;
364 }
365 
366 void
367 fuse_vnode_refreshsize(struct vnode *vp, struct ucred *cred)
368 {
369 
370 	struct fuse_vnode_data *fvdat = VTOFUD(vp);
371 	struct vattr va;
372 
373 	if ((fvdat->flag & FN_SIZECHANGE) != 0 ||
374 	    (fuse_refresh_size == 0 && fvdat->filesize != 0))
375 		return;
376 
377 	VOP_GETATTR(vp, &va, cred);
378 	FS_DEBUG("refreshed file size: %jd\n", (intmax_t)VTOFUD(vp)->filesize);
379 }
380 
381 int
382 fuse_vnode_setsize(struct vnode *vp, struct ucred *cred, off_t newsize)
383 {
384 	struct fuse_vnode_data *fvdat = VTOFUD(vp);
385 	off_t oldsize;
386 	int err = 0;
387 
388 	FS_DEBUG("inode=%ju oldsize=%ju newsize=%ju\n",
389 	    (uintmax_t)VTOI(vp), (uintmax_t)fvdat->filesize,
390 	    (uintmax_t)newsize);
391 	ASSERT_VOP_ELOCKED(vp, "fuse_vnode_setsize");
392 
393 	oldsize = fvdat->filesize;
394 	fvdat->filesize = newsize;
395 	fvdat->flag |= FN_SIZECHANGE;
396 
397 	if (newsize < oldsize) {
398 		err = vtruncbuf(vp, cred, newsize, fuse_iosize(vp));
399 	}
400 	vnode_pager_setsize(vp, newsize);
401 	return err;
402 }
403