xref: /freebsd/sys/fs/fuse/fuse_file.c (revision 43d1e6ee299ad4e143d90d3ad374d1c24bd3306f)
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/param.h>
62 #include <sys/module.h>
63 #include <sys/systm.h>
64 #include <sys/errno.h>
65 #include <sys/kernel.h>
66 #include <sys/conf.h>
67 #include <sys/uio.h>
68 #include <sys/malloc.h>
69 #include <sys/queue.h>
70 #include <sys/lock.h>
71 #include <sys/sx.h>
72 #include <sys/mutex.h>
73 #include <sys/proc.h>
74 #include <sys/mount.h>
75 #include <sys/vnode.h>
76 #include <sys/sdt.h>
77 #include <sys/sysctl.h>
78 
79 #include "fuse.h"
80 #include "fuse_file.h"
81 #include "fuse_internal.h"
82 #include "fuse_ipc.h"
83 #include "fuse_node.h"
84 
85 SDT_PROVIDER_DECLARE(fuse);
86 /*
87  * Fuse trace probe:
88  * arg0: verbosity.  Higher numbers give more verbose messages
89  * arg1: Textual message
90  */
91 SDT_PROBE_DEFINE2(fuse, , file, trace, "int", "char*");
92 
93 static int fuse_fh_count = 0;
94 
95 SYSCTL_INT(_vfs_fusefs, OID_AUTO, filehandle_count, CTLFLAG_RD,
96     &fuse_fh_count, 0, "number of open FUSE filehandles");
97 
98 int
99 fuse_filehandle_open(struct vnode *vp, fufh_type_t fufh_type,
100     struct fuse_filehandle **fufhp, struct thread *td, struct ucred *cred)
101 {
102 	struct fuse_dispatcher fdi;
103 	struct fuse_open_in *foi;
104 	struct fuse_open_out *foo;
105 
106 	int err = 0;
107 	int oflags = 0;
108 	int op = FUSE_OPEN;
109 
110 	if (fuse_filehandle_valid(vp, fufh_type)) {
111 		panic("FUSE: filehandle_open called despite valid fufh (type=%d)",
112 		    fufh_type);
113 		/* NOTREACHED */
114 	}
115 	/*
116 	 * Note that this means we are effectively FILTERING OUT open() flags.
117 	 */
118 	oflags = fuse_filehandle_xlate_to_oflags(fufh_type);
119 
120 	if (vnode_isdir(vp)) {
121 		op = FUSE_OPENDIR;
122 		if (fufh_type != FUFH_RDONLY) {
123 			SDT_PROBE2(fuse, , file, trace, 1,
124 				"non-rdonly fh requested for a directory?");
125 			printf("FUSE:non-rdonly fh requested for a directory?\n");
126 			fufh_type = FUFH_RDONLY;
127 		}
128 	}
129 	fdisp_init(&fdi, sizeof(*foi));
130 	fdisp_make_vp(&fdi, op, vp, td, cred);
131 
132 	foi = fdi.indata;
133 	foi->flags = oflags;
134 
135 	if ((err = fdisp_wait_answ(&fdi))) {
136 		SDT_PROBE2(fuse, , file, trace, 1,
137 			"OUCH ... daemon didn't give fh");
138 		if (err == ENOENT) {
139 			fuse_internal_vnode_disappear(vp);
140 		}
141 		goto out;
142 	}
143 	foo = fdi.answ;
144 
145 	fuse_filehandle_init(vp, fufh_type, fufhp, foo->fh);
146 
147 	/*
148 	 * For WRONLY opens, force DIRECT_IO.  This is necessary
149 	 * since writing a partial block through the buffer cache
150 	 * will result in a read of the block and that read won't
151 	 * be allowed by the WRONLY open.
152 	 */
153 	if (fufh_type == FUFH_WRONLY)
154 		fuse_vnode_open(vp, foo->open_flags | FOPEN_DIRECT_IO, td);
155 	else
156 		fuse_vnode_open(vp, foo->open_flags, td);
157 
158 out:
159 	fdisp_destroy(&fdi);
160 	return err;
161 }
162 
163 int
164 fuse_filehandle_close(struct vnode *vp, fufh_type_t fufh_type,
165     struct thread *td, struct ucred *cred)
166 {
167 	struct fuse_dispatcher fdi;
168 	struct fuse_release_in *fri;
169 	struct fuse_vnode_data *fvdat = VTOFUD(vp);
170 	struct fuse_filehandle *fufh = NULL;
171 
172 	int err = 0;
173 	int op = FUSE_RELEASE;
174 
175 	fufh = &(fvdat->fufh[fufh_type]);
176 	if (!FUFH_IS_VALID(fufh)) {
177 		panic("FUSE: filehandle_put called on invalid fufh (type=%d)",
178 		    fufh_type);
179 		/* NOTREACHED */
180 	}
181 	if (fuse_isdeadfs(vp)) {
182 		goto out;
183 	}
184 	if (vnode_isdir(vp))
185 		op = FUSE_RELEASEDIR;
186 	fdisp_init(&fdi, sizeof(*fri));
187 	fdisp_make_vp(&fdi, op, vp, td, cred);
188 	fri = fdi.indata;
189 	fri->fh = fufh->fh_id;
190 	fri->flags = fuse_filehandle_xlate_to_oflags(fufh_type);
191 
192 	err = fdisp_wait_answ(&fdi);
193 	fdisp_destroy(&fdi);
194 
195 out:
196 	atomic_subtract_acq_int(&fuse_fh_count, 1);
197 	fufh->fh_id = (uint64_t)-1;
198 	fufh->fh_type = FUFH_INVALID;
199 
200 	return err;
201 }
202 
203 int
204 fuse_filehandle_valid(struct vnode *vp, fufh_type_t fufh_type)
205 {
206 	struct fuse_vnode_data *fvdat = VTOFUD(vp);
207 	struct fuse_filehandle *fufh;
208 
209 	fufh = &(fvdat->fufh[fufh_type]);
210 	return FUFH_IS_VALID(fufh);
211 }
212 
213 /*
214  * Check for a valid file handle, first the type requested, but if that
215  * isn't valid, try for FUFH_RDWR.
216  * Return the FUFH type that is valid or FUFH_INVALID if there are none.
217  * This is a variant of fuse_filehandle_vaild() analogous to
218  * fuse_filehandle_getrw().
219  */
220 fufh_type_t
221 fuse_filehandle_validrw(struct vnode *vp, fufh_type_t fufh_type)
222 {
223 	struct fuse_vnode_data *fvdat = VTOFUD(vp);
224 	struct fuse_filehandle *fufh;
225 
226 	fufh = &fvdat->fufh[fufh_type];
227 	if (FUFH_IS_VALID(fufh) != 0)
228 		return (fufh_type);
229 	fufh = &fvdat->fufh[FUFH_RDWR];
230 	if (FUFH_IS_VALID(fufh) != 0)
231 		return (FUFH_RDWR);
232 	return (FUFH_INVALID);
233 }
234 
235 int
236 fuse_filehandle_get(struct vnode *vp, fufh_type_t fufh_type,
237     struct fuse_filehandle **fufhp)
238 {
239 	struct fuse_vnode_data *fvdat = VTOFUD(vp);
240 	struct fuse_filehandle *fufh;
241 
242 	fufh = &(fvdat->fufh[fufh_type]);
243 	if (!FUFH_IS_VALID(fufh))
244 		return EBADF;
245 	if (fufhp != NULL)
246 		*fufhp = fufh;
247 	return 0;
248 }
249 
250 int
251 fuse_filehandle_getrw(struct vnode *vp, fufh_type_t fufh_type,
252     struct fuse_filehandle **fufhp)
253 {
254 	struct fuse_vnode_data *fvdat = VTOFUD(vp);
255 	struct fuse_filehandle *fufh;
256 
257 	fufh = &(fvdat->fufh[fufh_type]);
258 	if (!FUFH_IS_VALID(fufh)) {
259 		fufh_type = FUFH_RDWR;
260 	}
261 	return fuse_filehandle_get(vp, fufh_type, fufhp);
262 }
263 
264 void
265 fuse_filehandle_init(struct vnode *vp, fufh_type_t fufh_type,
266     struct fuse_filehandle **fufhp, uint64_t fh_id)
267 {
268 	struct fuse_vnode_data *fvdat = VTOFUD(vp);
269 	struct fuse_filehandle *fufh;
270 
271 	fufh = &(fvdat->fufh[fufh_type]);
272 	MPASS(!FUFH_IS_VALID(fufh));
273 	fufh->fh_id = fh_id;
274 	fufh->fh_type = fufh_type;
275 	if (!FUFH_IS_VALID(fufh)) {
276 		panic("FUSE: init: invalid filehandle id (type=%d)", fufh_type);
277 	}
278 	if (fufhp != NULL)
279 		*fufhp = fufh;
280 
281 	atomic_add_acq_int(&fuse_fh_count, 1);
282 }
283