xref: /titanic_41/usr/src/uts/common/fs/cachefs/cachefs_module.c (revision db0d7085f45406af6c45f0b36804a0a97f078084)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  * Copyright (c) 2011 Bayard G. Bell. All rights reserved.
26  */
27 
28 #include <sys/errno.h>
29 #include <sys/param.h>
30 #include <sys/types.h>
31 #include <sys/user.h>
32 #include <sys/stat.h>
33 #include <sys/time.h>
34 #include <sys/vfs.h>
35 #include <sys/vnode.h>
36 #include <rpc/types.h>
37 #include <sys/mode.h>
38 #include <sys/cmn_err.h>
39 #include <sys/debug.h>
40 #include <sys/fs/cachefs_fs.h>
41 
42 /*
43  * This is the loadable module wrapper.
44  */
45 #include <sys/systm.h>
46 #include <sys/modctl.h>
47 #include <sys/syscall.h>
48 
49 extern time_t time;
50 
51 static int cachefs_init(int, char *);
52 static void cachefs_fini();
53 
54 static int cachefs_unloadable = 0; /* tunable */
55 static boolean_t cachefs_up = B_FALSE;
56 
57 uint_t cachefs_max_apop_inqueue = CACHEFS_MAX_APOP_INQUEUE;
58 
59 /*
60  * this is a list of possible hash table sizes, for the `double
61  * hashing' algorithm described in rosen's `elementary number theory
62  * and its applications'.  minimally, this needs to be a list of
63  * increasing prime integers, terminated by a 0.  ideally, they should
64  * be the larger of twin primes; i.e. P and P-2 are both prime.
65  */
66 
67 int cachefs_hash_sizes[] = {5, 2029, 4093, 8089, 16363, 32719, 0};
68 
69 /*
70  * Module linkage information for the kernel.
71  */
72 
73 static vfsdef_t vfs_z = {
74 	VFSDEF_VERSION,
75 	CACHEFS_BASETYPE,
76 	cachefs_init,
77 	VSW_CANREMOUNT,
78 	NULL
79 };
80 
81 static struct modlfs modlfs = {
82 	&mod_fsops,
83 	"cache filesystem",
84 	&vfs_z
85 };
86 
87 static struct modlinkage modlinkage = {
88 	MODREV_1, (void *)&modlfs, NULL
89 };
90 
91 int
92 _init(void)
93 {
94 	int status;
95 
96 	status = mod_install(&modlinkage);
97 	if (status != 0) {
98 		/*
99 		 * Could not load module, clean up the work performed
100 		 * by cachefs_init() which was indirectly called by
101 		 * mod_installfs() which in turn was called by mod_install().
102 		 */
103 		cachefs_fini();
104 	}
105 
106 	return (status);
107 }
108 
109 int
110 _info(struct modinfo *modinfop)
111 {
112 	return (mod_info(&modlinkage, modinfop));
113 }
114 
115 int
116 _fini(void)
117 {
118 	int status;
119 
120 	if (!cachefs_unloadable)
121 		return (EBUSY);
122 
123 	if ((status = mod_remove(&modlinkage)) == 0) {
124 		/*
125 		 * Module has been unloaded, now clean up
126 		 */
127 		cachefs_fini();
128 	}
129 
130 	return (status);
131 }
132 
133 extern kmutex_t cachefs_cachelock;		/* Cache list mutex */
134 extern kmutex_t cachefs_newnum_lock;
135 extern kmutex_t cachefs_kstat_key_lock;
136 extern kmutex_t cachefs_rename_lock;
137 extern kmutex_t cachefs_minor_lock;	/* Lock for minor device map */
138 extern kmutex_t cachefs_kmem_lock;
139 extern kmutex_t cachefs_async_lock;	/* global async work count */
140 extern major_t cachefs_major;
141 
142 /*
143  * Cache initialization routine.  This routine should only be called
144  * once.  It performs the following tasks:
145  *	- Initalize all global locks
146  * 	- Call sub-initialization routines (localize access to variables)
147  */
148 static int
149 cachefs_init(int fstyp, char *name)
150 {
151 	kstat_t *ksp;
152 	int error;
153 
154 	ASSERT(cachefs_up == B_FALSE);
155 
156 	error = cachefs_init_vfsops(fstyp);
157 	if (error != 0)
158 		return (error);
159 
160 	error = cachefs_init_vnops(name);
161 	if (error != 0)
162 		return (error);
163 
164 	mutex_init(&cachefs_cachelock, NULL, MUTEX_DEFAULT, NULL);
165 	mutex_init(&cachefs_newnum_lock, NULL, MUTEX_DEFAULT, NULL);
166 	mutex_init(&cachefs_kstat_key_lock, NULL, MUTEX_DEFAULT, NULL);
167 	mutex_init(&cachefs_kmem_lock, NULL, MUTEX_DEFAULT, NULL);
168 	mutex_init(&cachefs_rename_lock, NULL, MUTEX_DEFAULT, NULL);
169 	mutex_init(&cachefs_minor_lock, NULL, MUTEX_DEFAULT, NULL);
170 	mutex_init(&cachefs_async_lock, NULL, MUTEX_DEFAULT, NULL);
171 #ifdef CFSRLDEBUG
172 	mutex_init(&cachefs_rl_debug_mutex, NULL, MUTEX_DEFAULT, NULL);
173 #endif /* CFSRLDEBUG */
174 
175 	/*
176 	 * set up kmem_cache entities
177 	 */
178 
179 	cachefs_cnode_cache = kmem_cache_create("cachefs_cnode_cache",
180 	    sizeof (struct cnode), 0, NULL, NULL, NULL, NULL, NULL, 0);
181 	cachefs_req_cache = kmem_cache_create("cachefs_async_request",
182 	    sizeof (struct cachefs_req), 0,
183 	    cachefs_req_create, cachefs_req_destroy, NULL, NULL, NULL, 0);
184 	cachefs_fscache_cache = kmem_cache_create("cachefs_fscache",
185 	    sizeof (fscache_t), 0, NULL, NULL, NULL, NULL, NULL, 0);
186 	cachefs_filegrp_cache = kmem_cache_create("cachefs_filegrp",
187 	    sizeof (filegrp_t), 0,
188 	    filegrp_cache_create, filegrp_cache_destroy, NULL, NULL, NULL, 0);
189 	cachefs_cache_kmcache = kmem_cache_create("cachefs_cache_t",
190 	    sizeof (cachefscache_t), 0, NULL, NULL, NULL, NULL, NULL, 0);
191 
192 	/*
193 	 * set up the cachefs.0.key kstat
194 	 */
195 
196 	cachefs_kstat_key = NULL;
197 	cachefs_kstat_key_n = 0;
198 	ksp = kstat_create("cachefs", 0, "key", "misc", KSTAT_TYPE_RAW, 1,
199 	    KSTAT_FLAG_VIRTUAL | KSTAT_FLAG_VAR_SIZE);
200 	if (ksp != NULL) {
201 		ksp->ks_data = &cachefs_kstat_key;
202 		ksp->ks_update = cachefs_kstat_key_update;
203 		ksp->ks_snapshot = cachefs_kstat_key_snapshot;
204 		ksp->ks_lock = &cachefs_kstat_key_lock;
205 		kstat_install(ksp);
206 	}
207 
208 	/*
209 	 * Assign unique major number for all nfs mounts
210 	 */
211 
212 	if ((cachefs_major = getudev()) == -1) {
213 		cmn_err(CE_WARN,
214 			"cachefs: init: can't get unique device number");
215 		cachefs_major = 0;
216 	}
217 	cachefs_up = B_TRUE;
218 #ifdef CFSRLDEBUG
219 	cachefs_dbvalid = time;
220 #endif /* CFSRLDEBUG */
221 
222 	return (0);
223 }
224 
225 /*
226  * Cache clean up routine. This routine is called if mod_install() failed
227  * and we have to clean up because the module could not be installed,
228  * or by _fini() when we're unloading the module.
229  */
230 static void
231 cachefs_fini()
232 {
233 	extern int cachefsfstyp;
234 	extern struct vnodeops *cachefs_vnodeops;
235 
236 	if (cachefs_up == B_FALSE) {
237 		/*
238 		 * cachefs_init() was not called on _init(),
239 		 * nothing to deallocate.
240 		 */
241 		return;
242 	}
243 
244 	/*
245 	 * Clean up cachefs.0.key kstat.
246 	 * Currently, you can only do a
247 	 * modunload if cachefs_unloadable is nonzero, and that's
248 	 * pretty much just for debugging.  however, if there ever
249 	 * comes a day when cachefs is more freely unloadable
250 	 * (e.g. the modunload daemon can do it normally), then we'll
251 	 * have to make changes in the stats_ API.  this is because a
252 	 * stats_cookie_t holds the id # derived from here, and it
253 	 * will all go away at modunload time.  thus, the API will
254 	 * need to somehow be more robust than is currently necessary.
255 	 */
256 	kstat_delete_byname("cachefs", 0, "key");
257 
258 	if (cachefs_kstat_key != NULL) {
259 		cachefs_kstat_key_t *key;
260 		int i;
261 
262 		for (i = 0; i < cachefs_kstat_key_n; i++) {
263 			key = cachefs_kstat_key + i;
264 
265 			cachefs_kmem_free((void *)(uintptr_t)key->ks_mountpoint,
266 			    strlen((char *)(uintptr_t)key->ks_mountpoint) + 1);
267 			cachefs_kmem_free((void *)(uintptr_t)key->ks_backfs,
268 			    strlen((char *)(uintptr_t)key->ks_backfs) + 1);
269 			cachefs_kmem_free((void *)(uintptr_t)key->ks_cachedir,
270 			    strlen((char *)(uintptr_t)key->ks_cachedir) + 1);
271 			cachefs_kmem_free((void *)(uintptr_t)key->ks_cacheid,
272 			    strlen((char *)(uintptr_t)key->ks_cacheid) + 1);
273 		}
274 
275 		cachefs_kmem_free(cachefs_kstat_key,
276 		    cachefs_kstat_key_n * sizeof (*cachefs_kstat_key));
277 	}
278 
279 	/*
280 	 * Clean up kmem_cache entities
281 	 */
282 	kmem_cache_destroy(cachefs_cache_kmcache);
283 	kmem_cache_destroy(cachefs_filegrp_cache);
284 	kmem_cache_destroy(cachefs_fscache_cache);
285 	kmem_cache_destroy(cachefs_req_cache);
286 	kmem_cache_destroy(cachefs_cnode_cache);
287 #ifdef CFSRLDEBUG
288 	if (cachefs_rl_debug_cache != NULL)
289 		kmem_cache_destroy(cachefs_rl_debug_cache);
290 #endif /* CFSRLDEBUG */
291 
292 	/*
293 	 * Clean up the operations structures
294 	 */
295 	(void) vfs_freevfsops_by_type(cachefsfstyp);
296 	vn_freevnodeops(cachefs_vnodeops);
297 
298 	/*
299 	 * Destroy mutexes
300 	 */
301 #ifdef CFSRLDEBUG
302 	mutex_destroy(&cachefs_rl_debug_mutex);
303 #endif /* CFSRLDEBUG */
304 	mutex_destroy(&cachefs_async_lock);
305 	mutex_destroy(&cachefs_minor_lock);
306 	mutex_destroy(&cachefs_rename_lock);
307 	mutex_destroy(&cachefs_kmem_lock);
308 	mutex_destroy(&cachefs_kstat_key_lock);
309 	mutex_destroy(&cachefs_newnum_lock);
310 	mutex_destroy(&cachefs_cachelock);
311 }
312