xref: /freebsd/sys/fs/fuse/fuse_file.c (revision ca987d4641cdcd7f27e153db17c5bf064934faf5)
1 /*
2  * Copyright (c) 2007-2009 Google Inc. and Amit Singh
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions are
7  * met:
8  *
9  * * Redistributions of source code must retain the above copyright
10  *   notice, this list of conditions and the following disclaimer.
11  * * Redistributions in binary form must reproduce the above
12  *   copyright notice, this list of conditions and the following disclaimer
13  *   in the documentation and/or other materials provided with the
14  *   distribution.
15  * * Neither the name of Google Inc. nor the names of its
16  *   contributors may be used to endorse or promote products derived from
17  *   this software without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
23  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
25  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30  *
31  * Copyright (C) 2005 Csaba Henk.
32  * All rights reserved.
33  *
34  * Redistribution and use in source and binary forms, with or without
35  * modification, are permitted provided that the following conditions
36  * are met:
37  * 1. Redistributions of source code must retain the above copyright
38  *    notice, this list of conditions and the following disclaimer.
39  * 2. Redistributions in binary form must reproduce the above copyright
40  *    notice, this list of conditions and the following disclaimer in the
41  *    documentation and/or other materials provided with the distribution.
42  *
43  * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
44  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
45  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
46  * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
47  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
48  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
49  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
50  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
51  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
52  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
53  * SUCH DAMAGE.
54  */
55 
56 #include <sys/cdefs.h>
57 __FBSDID("$FreeBSD$");
58 
59 #include <sys/types.h>
60 #include <sys/module.h>
61 #include <sys/systm.h>
62 #include <sys/errno.h>
63 #include <sys/param.h>
64 #include <sys/kernel.h>
65 #include <sys/conf.h>
66 #include <sys/uio.h>
67 #include <sys/malloc.h>
68 #include <sys/queue.h>
69 #include <sys/lock.h>
70 #include <sys/sx.h>
71 #include <sys/mutex.h>
72 #include <sys/proc.h>
73 #include <sys/mount.h>
74 #include <sys/vnode.h>
75 #include <sys/sysctl.h>
76 
77 #include "fuse.h"
78 #include "fuse_file.h"
79 #include "fuse_internal.h"
80 #include "fuse_ipc.h"
81 #include "fuse_node.h"
82 
83 #define FUSE_DEBUG_MODULE FILE
84 #include "fuse_debug.h"
85 
86 static int fuse_fh_count = 0;
87 
88 SYSCTL_INT(_vfs_fuse, OID_AUTO, filehandle_count, CTLFLAG_RD,
89     &fuse_fh_count, 0, "");
90 
91 int
92 fuse_filehandle_open(struct vnode *vp,
93     fufh_type_t fufh_type,
94     struct fuse_filehandle **fufhp,
95     struct thread *td,
96     struct ucred *cred)
97 {
98 	struct fuse_dispatcher fdi;
99 	struct fuse_open_in *foi;
100 	struct fuse_open_out *foo;
101 
102 	int err = 0;
103 	int isdir = 0;
104 	int oflags = 0;
105 	int op = FUSE_OPEN;
106 
107 	fuse_trace_printf("fuse_filehandle_open(vp=%p, fufh_type=%d)\n",
108 	    vp, fufh_type);
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 		isdir = 1;
122 		op = FUSE_OPENDIR;
123 		if (fufh_type != FUFH_RDONLY) {
124 			printf("FUSE:non-rdonly fh requested for a directory?\n");
125 			fufh_type = FUFH_RDONLY;
126 		}
127 	}
128 	fdisp_init(&fdi, sizeof(*foi));
129 	fdisp_make_vp(&fdi, op, vp, td, cred);
130 
131 	foi = fdi.indata;
132 	foi->flags = oflags;
133 
134 	if ((err = fdisp_wait_answ(&fdi))) {
135 		debug_printf("OUCH ... daemon didn't give fh (err = %d)\n", err);
136 		if (err == ENOENT) {
137 			fuse_internal_vnode_disappear(vp);
138 		}
139 		goto out;
140 	}
141 	foo = fdi.answ;
142 
143 	fuse_filehandle_init(vp, fufh_type, fufhp, foo->fh);
144 
145 	/*
146 	 * For WRONLY opens, force DIRECT_IO.  This is necessary
147 	 * since writing a partial block through the buffer cache
148 	 * will result in a read of the block and that read won't
149 	 * be allowed by the WRONLY open.
150 	 */
151 	if (fufh_type == FUFH_WRONLY)
152 		fuse_vnode_open(vp, foo->open_flags | FOPEN_DIRECT_IO, td);
153 	else
154 		fuse_vnode_open(vp, foo->open_flags, td);
155 
156 out:
157 	fdisp_destroy(&fdi);
158 	return err;
159 }
160 
161 int
162 fuse_filehandle_close(struct vnode *vp,
163     fufh_type_t fufh_type,
164     struct thread *td,
165     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 isdir = 0;
174 	int op = FUSE_RELEASE;
175 
176 	fuse_trace_printf("fuse_filehandle_put(vp=%p, fufh_type=%d)\n",
177 	    vp, fufh_type);
178 
179 	fufh = &(fvdat->fufh[fufh_type]);
180 	if (!FUFH_IS_VALID(fufh)) {
181 		panic("FUSE: filehandle_put called on invalid fufh (type=%d)",
182 		    fufh_type);
183 		/* NOTREACHED */
184 	}
185 	if (fuse_isdeadfs(vp)) {
186 		goto out;
187 	}
188 	if (vnode_isdir(vp)) {
189 		op = FUSE_RELEASEDIR;
190 		isdir = 1;
191 	}
192 	fdisp_init(&fdi, sizeof(*fri));
193 	fdisp_make_vp(&fdi, op, vp, td, cred);
194 	fri = fdi.indata;
195 	fri->fh = fufh->fh_id;
196 	fri->flags = fuse_filehandle_xlate_to_oflags(fufh_type);
197 
198 	err = fdisp_wait_answ(&fdi);
199 	fdisp_destroy(&fdi);
200 
201 out:
202 	atomic_subtract_acq_int(&fuse_fh_count, 1);
203 	fufh->fh_id = (uint64_t)-1;
204 	fufh->fh_type = FUFH_INVALID;
205 
206 	return err;
207 }
208 
209 int
210 fuse_filehandle_valid(struct vnode *vp, fufh_type_t fufh_type)
211 {
212 	struct fuse_vnode_data *fvdat = VTOFUD(vp);
213 	struct fuse_filehandle *fufh;
214 
215 	fufh = &(fvdat->fufh[fufh_type]);
216 	return FUFH_IS_VALID(fufh);
217 }
218 
219 /*
220  * Check for a valid file handle, first the type requested, but if that
221  * isn't valid, try for FUFH_RDWR.
222  * Return the FUFH type that is valid or FUFH_INVALID if there are none.
223  * This is a variant of fuse_filehandle_vaild() analogous to
224  * fuse_filehandle_getrw().
225  */
226 fufh_type_t
227 fuse_filehandle_validrw(struct vnode *vp, fufh_type_t fufh_type)
228 {
229 	struct fuse_vnode_data *fvdat = VTOFUD(vp);
230 	struct fuse_filehandle *fufh;
231 
232 	fufh = &fvdat->fufh[fufh_type];
233 	if (FUFH_IS_VALID(fufh) != 0)
234 		return (fufh_type);
235 	fufh = &fvdat->fufh[FUFH_RDWR];
236 	if (FUFH_IS_VALID(fufh) != 0)
237 		return (FUFH_RDWR);
238 	return (FUFH_INVALID);
239 }
240 
241 int
242 fuse_filehandle_get(struct vnode *vp, fufh_type_t fufh_type,
243     struct fuse_filehandle **fufhp)
244 {
245 	struct fuse_vnode_data *fvdat = VTOFUD(vp);
246 	struct fuse_filehandle *fufh;
247 
248 	fufh = &(fvdat->fufh[fufh_type]);
249 	if (!FUFH_IS_VALID(fufh))
250 		return EBADF;
251 	if (fufhp != NULL)
252 		*fufhp = fufh;
253 	return 0;
254 }
255 
256 int
257 fuse_filehandle_getrw(struct vnode *vp, fufh_type_t fufh_type,
258     struct fuse_filehandle **fufhp)
259 {
260 	struct fuse_vnode_data *fvdat = VTOFUD(vp);
261 	struct fuse_filehandle *fufh;
262 
263 	fufh = &(fvdat->fufh[fufh_type]);
264 	if (!FUFH_IS_VALID(fufh)) {
265 		fufh_type = FUFH_RDWR;
266 	}
267 	return fuse_filehandle_get(vp, fufh_type, fufhp);
268 }
269 
270 void
271 fuse_filehandle_init(struct vnode *vp,
272     fufh_type_t fufh_type,
273     struct fuse_filehandle **fufhp,
274     uint64_t fh_id)
275 {
276 	struct fuse_vnode_data *fvdat = VTOFUD(vp);
277 	struct fuse_filehandle *fufh;
278 
279 	FS_DEBUG("id=%jd type=%d\n", (intmax_t)fh_id, fufh_type);
280 	fufh = &(fvdat->fufh[fufh_type]);
281 	MPASS(!FUFH_IS_VALID(fufh));
282 	fufh->fh_id = fh_id;
283 	fufh->fh_type = fufh_type;
284 	if (!FUFH_IS_VALID(fufh)) {
285 		panic("FUSE: init: invalid filehandle id (type=%d)", fufh_type);
286 	}
287 	if (fufhp != NULL)
288 		*fufhp = fufh;
289 
290 	atomic_add_acq_int(&fuse_fh_count, 1);
291 }
292