xref: /dragonfly/sys/vfs/autofs/autofs_vfsops.c (revision da0d35cf)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2016 Tomohiro Kusumi <tkusumi@netbsd.org>
5  * Copyright (c) 2016 The DragonFly Project
6  * Copyright (c) 2014 The FreeBSD Foundation
7  * All rights reserved.
8  *
9  * This software was developed by Edward Tomasz Napierala under sponsorship
10  * from the FreeBSD Foundation.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  */
34 
35 #include <sys/kernel.h>
36 #include <sys/module.h>
37 #include <sys/stat.h>
38 
39 #include "autofs.h"
40 #include "autofs_mount.h"
41 
42 static int	autofs_statfs(struct mount *mp, struct statfs *sbp,
43 		    struct ucred *cred);
44 
45 static struct objcache_malloc_args autofs_request_args = {
46 	sizeof(struct autofs_request), M_AUTOFS,
47 };
48 static struct objcache_malloc_args autofs_node_args = {
49 	sizeof(struct autofs_node), M_AUTOFS,
50 };
51 
52 static int
53 autofs_init(struct vfsconf *vfsp)
54 {
55 	KASSERT(autofs_softc == NULL,
56 	    ("softc %p, should be NULL", autofs_softc));
57 
58 	autofs_softc = kmalloc(sizeof(*autofs_softc), M_AUTOFS,
59 	    M_WAITOK | M_ZERO);
60 
61 	autofs_request_objcache = objcache_create("autofs_request", 0, 0,
62 		NULL, NULL, NULL,
63 		objcache_malloc_alloc_zero, objcache_malloc_free,
64 		&autofs_request_args);
65 
66 	autofs_node_objcache = objcache_create("autofs_node", 0, 0,
67 		NULL, NULL, NULL,
68 		objcache_malloc_alloc_zero, objcache_malloc_free,
69 		&autofs_node_args);
70 
71 	TAILQ_INIT(&autofs_softc->sc_requests);
72 	cv_init(&autofs_softc->sc_cv, "autofscv");
73 	mtx_init(&autofs_softc->sc_lock, "autofssclk");
74 	autofs_softc->sc_dev_opened = false;
75 
76 	autofs_softc->sc_cdev = make_dev(&autofs_ops, 0, UID_ROOT, GID_OPERATOR,
77 	    0640, "autofs");
78 	if (autofs_softc->sc_cdev == NULL) {
79 		AUTOFS_WARN("failed to create device node");
80 		objcache_destroy(autofs_request_objcache);
81 		objcache_destroy(autofs_node_objcache);
82 		kfree(autofs_softc, M_AUTOFS);
83 		return (ENODEV);
84 	}
85 	autofs_softc->sc_cdev->si_drv1 = autofs_softc;
86 
87 	return (0);
88 }
89 
90 static int
91 autofs_uninit(struct vfsconf *vfsp)
92 {
93 	mtx_lock_ex_quick(&autofs_softc->sc_lock);
94 	if (autofs_softc->sc_dev_opened) {
95 		mtx_unlock_ex(&autofs_softc->sc_lock);
96 		return (EBUSY);
97 	}
98 
99 	if (autofs_softc->sc_cdev != NULL)
100 		destroy_dev(autofs_softc->sc_cdev);
101 
102 	objcache_destroy(autofs_request_objcache);
103 	objcache_destroy(autofs_node_objcache);
104 
105 	mtx_unlock_ex(&autofs_softc->sc_lock);
106 
107 	kfree(autofs_softc, M_AUTOFS); /* race with open */
108 	autofs_softc = NULL;
109 
110 	return (0);
111 }
112 
113 static int
114 autofs_mount(struct mount *mp, char *mntpt, caddr_t data, struct ucred *cred)
115 {
116 	struct autofs_mount_info info;
117 	struct autofs_mount *amp;
118 	struct statfs *sbp = &mp->mnt_stat;
119 	int error;
120 
121 	if (mp->mnt_flag & MNT_UPDATE) {
122 		autofs_flush(VFSTOAUTOFS(mp));
123 		return (0);
124 	}
125 
126 	error = copyin(data, &info, sizeof(info));
127 	if (error)
128 		return (error);
129 
130 	/*
131 	 * Copy-in ->f_mntfromname string.
132 	 */
133 	memset(sbp->f_mntfromname, 0, sizeof(sbp->f_mntfromname));
134 	error = copyinstr(info.from, sbp->f_mntfromname,
135 	    sizeof(sbp->f_mntfromname), NULL);
136 	if (error)
137 		return (error);
138 	/*
139 	 * Copy-in ->f_mntonname string.
140 	 */
141 	memset(sbp->f_mntonname, 0, sizeof(sbp->f_mntonname));
142 	error = copyinstr(mntpt, sbp->f_mntonname, sizeof(sbp->f_mntonname),
143 	    NULL);
144 	if (error)
145 		return (error);
146 
147 	/*
148 	 * Allocate the autofs mount.
149 	 */
150 	amp = kmalloc(sizeof(*amp), M_AUTOFS, M_WAITOK | M_ZERO);
151 	mp->mnt_data = (qaddr_t)amp;
152 	strlcpy(amp->am_from, sbp->f_mntfromname, sizeof(amp->am_from));
153 	strlcpy(amp->am_on, sbp->f_mntonname, sizeof(amp->am_on));
154 
155 	/*
156 	 * Copy-in master_options string.
157 	 */
158 	error = copyinstr(info.master_options, amp->am_options,
159 	    sizeof(amp->am_options), NULL);
160 	if (error)
161 		goto fail;
162 	/*
163 	 * Copy-in master_prefix string.
164 	 */
165 	error = copyinstr(info.master_prefix, amp->am_prefix,
166 	    sizeof(amp->am_prefix), NULL);
167 	if (error)
168 		goto fail;
169 
170 	/*
171 	 * Initialize the autofs mount.
172 	 */
173 	mtx_init(&amp->am_lock, "autofsmnlk");
174 	amp->am_last_ino = AUTOFS_ROOTINO;
175 
176 	mtx_lock_ex_quick(&amp->am_lock);
177 	error = autofs_node_new(NULL, amp, ".", -1, &amp->am_root);
178 	mtx_unlock_ex(&amp->am_lock);
179 	KKASSERT(error == 0);
180 	KKASSERT(amp->am_root->an_ino == AUTOFS_ROOTINO);
181 
182 	vfs_getnewfsid(mp);
183 	vfs_add_vnodeops(mp, &autofs_vnode_vops, &mp->mnt_vn_norm_ops);
184 
185 	VFS_STATFS(mp, &mp->mnt_stat, cred);
186 
187 	return (0);
188 
189 fail:
190 	kfree(amp, M_AUTOFS);
191 	return (error);
192 }
193 
194 static int
195 autofs_unmount(struct mount *mp, int mntflags)
196 {
197 	struct autofs_mount *amp = VFSTOAUTOFS(mp);
198 	int error, flags;
199 
200 	flags = 0;
201 	if (mntflags & MNT_FORCE)
202 		flags |= FORCECLOSE;
203 	error = vflush(mp, 0, flags);
204 	if (error) {
205 		AUTOFS_DEBUG("vflush failed with error %d", error);
206 		return (error);
207 	}
208 
209 	/*
210 	 * All vnodes are gone, and new one will not appear - so,
211 	 * no new triggerings.
212 	 */
213 	for (;;) {
214 		struct autofs_request *ar;
215 		int dummy;
216 		bool found;
217 
218 		found = false;
219 		mtx_lock_ex_quick(&autofs_softc->sc_lock);
220 		TAILQ_FOREACH(ar, &autofs_softc->sc_requests, ar_next) {
221 			if (ar->ar_mount != amp)
222 				continue;
223 			ar->ar_error = ENXIO;
224 			ar->ar_done = true;
225 			ar->ar_in_progress = false;
226 			found = true;
227 		}
228 		if (found == false) {
229 			mtx_unlock_ex(&autofs_softc->sc_lock);
230 			break;
231 		}
232 
233 		cv_broadcast(&autofs_softc->sc_cv);
234 		mtx_unlock_ex(&autofs_softc->sc_lock);
235 
236 		tsleep(&dummy, 0, "autofs_umount", hz);
237 	}
238 
239 	mtx_lock_ex_quick(&amp->am_lock);
240 	while (!RB_EMPTY(&amp->am_root->an_children)) {
241 		struct autofs_node *anp;
242 		/*
243 		 * Force delete all nodes when more than one level of
244 		 * directories are created via indirect map. Autofs doesn't
245 		 * support rmdir(2), thus this is the only way to get out.
246 		 */
247 		anp = RB_MIN(autofs_node_tree, &amp->am_root->an_children);
248 		while (!RB_EMPTY(&anp->an_children))
249 			anp = RB_MIN(autofs_node_tree, &anp->an_children);
250 		autofs_node_delete(anp);
251 	}
252 	autofs_node_delete(amp->am_root);
253 	mp->mnt_data = NULL;
254 	mtx_unlock_ex(&amp->am_lock);
255 
256 	mtx_uninit(&amp->am_lock);
257 
258 	kfree(amp, M_AUTOFS);
259 
260 	return (0);
261 }
262 
263 static int
264 autofs_root(struct mount *mp, struct vnode **vpp)
265 {
266 	struct autofs_mount *amp = VFSTOAUTOFS(mp);
267 	int error;
268 
269 	KASSERT(amp->am_root, ("no root node"));
270 
271 	error = autofs_node_vn(amp->am_root, mp, LK_EXCLUSIVE, vpp);
272 	if (error == 0) {
273 		struct vnode *vp = *vpp;
274 		vp->v_flag |= VROOT;
275 		KKASSERT(vp->v_type == VDIR);
276 	}
277 
278 	return (error);
279 }
280 
281 static int
282 autofs_statfs(struct mount *mp, struct statfs *sbp, struct ucred *cred)
283 {
284 	sbp->f_bsize = S_BLKSIZE;
285 	sbp->f_iosize = 0;
286 	sbp->f_blocks = 0;
287 	sbp->f_bfree = 0;
288 	sbp->f_bavail = 0;
289 	sbp->f_files = 0;
290 	sbp->f_ffree = 0;
291 
292 	return (0);
293 }
294 
295 static int
296 autofs_statvfs(struct mount *mp, struct statvfs *sbp, struct ucred *cred)
297 {
298 	sbp->f_bsize = S_BLKSIZE;
299 	sbp->f_frsize = 0;
300 	sbp->f_blocks = 0;
301 	sbp->f_bfree = 0;
302 	sbp->f_bavail = 0;
303 	sbp->f_files = 0;
304 	sbp->f_ffree = 0;
305 
306 	return (0);
307 }
308 
309 static struct vfsops autofs_vfsops = {
310 	.vfs_flags =		0,
311 	.vfs_mount =		autofs_mount,
312 	.vfs_unmount =		autofs_unmount,
313 	.vfs_root =		autofs_root,
314 	.vfs_statfs =		autofs_statfs,
315 	.vfs_statvfs =		autofs_statvfs,
316 	.vfs_init =		autofs_init,
317 	.vfs_uninit =		autofs_uninit,
318 };
319 
320 VFS_SET(autofs_vfsops, autofs, VFCF_SYNTHETIC | VFCF_MPSAFE);
321 MODULE_VERSION(autofs, 1);
322