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[fs/lustre-release.git] / lustre / obdclass / genops.c
1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
2  * vim:expandtab:shiftwidth=8:tabstop=8:
3 *
4  *  linux/fs/ext2_obd/sim_obd.c
5  * Copyright (C) 2001  Cluster File Systems, Inc.
6  *
7  * This code is issued under the GNU General Public License.
8  * See the file COPYING in this distribution
9  *
10  * These are the only exported functions, they provide some generic
11  * infrastructure for managing object devices
12  *
13  */
14
15 #define DEBUG_SUBSYSTEM S_CLASS
16 #include <linux/kmod.h>   /* for request_module() */
17 #include <linux/module.h>
18 #include <linux/obd_class.h>
19 #include <linux/random.h>
20 #include <linux/slab.h>
21
22 extern struct list_head obd_types;
23 extern struct obd_device obd_dev[MAX_OBD_DEVICES];
24 kmem_cache_t *obdo_cachep = NULL;
25 kmem_cache_t *export_cachep = NULL;
26 kmem_cache_t *import_cachep = NULL;
27
28 /*
29  * support functions: we could use inter-module communication, but this
30  * is more portable to other OS's
31  */
32 static struct obd_type *class_search_type(char *nm)
33 {
34         struct list_head *tmp;
35         struct obd_type *type;
36         CDEBUG(D_INFO, "SEARCH %s\n", nm);
37
38         tmp = &obd_types;
39         while ( (tmp = tmp->next) != &obd_types ) {
40                 type = list_entry(tmp, struct obd_type, typ_chain);
41                 CDEBUG(D_INFO, "TYP %s\n", type->typ_name);
42                 if (strlen(type->typ_name) == strlen(nm) &&
43                     strcmp(type->typ_name, nm) == 0 ) {
44                         return type;
45                 }
46         }
47         return NULL;
48 }
49
50 struct obd_type *class_nm_to_type(char *nm)
51 {
52         struct obd_type *type = class_search_type(nm);
53
54 #ifdef CONFIG_KMOD
55         if ( !type ) {
56                 if ( !request_module(nm) ) {
57                         CDEBUG(D_INFO, "Loaded module '%s'\n", nm);
58                         type = class_search_type(nm);
59                 } else {
60                         CDEBUG(D_INFO, "Can't load module '%s'\n", nm);
61                 }
62         }
63 #endif
64         return type;
65 }
66
67 int class_register_type(struct obd_ops *ops, char *nm)
68 {
69         struct obd_type *type;
70
71         ENTRY;
72
73         if (class_search_type(nm)) {
74                 CDEBUG(D_IOCTL, "Type %s already registered\n", nm);
75                 RETURN(-EEXIST);
76         }
77
78         OBD_ALLOC(type, sizeof(*type));
79         if (!type)
80                 RETURN(-ENOMEM);
81         INIT_LIST_HEAD(&type->typ_chain);
82         MOD_INC_USE_COUNT;
83         list_add(&type->typ_chain, obd_types.next);
84         type->typ_ops = ops;
85         type->typ_name = nm;
86         RETURN(0);
87 }
88
89 int class_unregister_type(char *nm)
90 {
91         struct obd_type *type = class_nm_to_type(nm);
92
93         ENTRY;
94
95         if ( !type ) {
96                 CERROR("unknown obd type\n");
97                 RETURN(-EINVAL);
98         }
99
100         if ( type->typ_refcnt ) {
101                 CERROR("type %s has refcount (%d)\n", nm, type->typ_refcnt);
102                 RETURN(-EBUSY);
103         }
104
105         list_del(&type->typ_chain);
106         OBD_FREE(type, sizeof(*type));
107         MOD_DEC_USE_COUNT;
108         RETURN(0);
109 } /* class_unregister_type */
110
111 int class_name2dev(char *name)
112 {
113         int res = -1;
114         int i;
115
116         if (!name)
117                 return -1;
118
119         for (i=0; i < MAX_OBD_DEVICES; i++) {
120                 struct obd_device *obd = &obd_dev[i];
121                 if (obd->obd_name && strcmp(name, obd->obd_name) == 0) {
122                         res = i;
123                         return res;
124                 }
125         }
126
127         return res;
128 }
129
130 int class_uuid2dev(char *name)
131 {
132         int res = -1;
133         int i;
134
135         for (i=0; i < MAX_OBD_DEVICES; i++) {
136                 struct obd_device *obd = &obd_dev[i];
137                 if (obd->obd_name && strncmp(name, obd->obd_uuid, 37) == 0) {
138                         res = i;
139                         return res;
140                 }
141         }
142
143         return res;
144 }
145
146
147 struct obd_device *class_uuid2obd(char *name)
148 {
149         int i;
150
151         for (i=0; i < MAX_OBD_DEVICES; i++) {
152                 struct obd_device *obd = &obd_dev[i];
153                 if (obd->obd_name && strncmp(name, obd->obd_uuid, 37) == 0) {
154                         return obd;
155                 }
156         }
157
158         return NULL;
159 }
160
161 void obd_cleanup_caches(void)
162 {
163         int rc;
164         ENTRY;
165         if (obdo_cachep) {
166                 rc = kmem_cache_destroy(obdo_cachep);
167                 if (rc)
168                         CERROR("Cannot destory obdo_cachep\n");
169                 obdo_cachep = NULL;
170         }
171         if (import_cachep) {
172                 rc = kmem_cache_destroy(import_cachep);
173                 if (rc)
174                         CERROR("Cannot destory import_cachep\n");
175                 import_cachep = NULL;
176         }
177         if (export_cachep) {
178                 rc = kmem_cache_destroy(export_cachep);
179                 if (rc)
180                         CERROR("Cannot destory import_cachep\n");
181                 export_cachep = NULL;
182         }
183         EXIT;
184 }
185
186 int obd_init_caches(void)
187 {
188         ENTRY;
189         if (obdo_cachep == NULL) {
190                 obdo_cachep = kmem_cache_create("obdo_cache",
191                                                 sizeof(struct obdo),
192                                                 0, SLAB_HWCACHE_ALIGN,
193                                                 NULL, NULL);
194                 if (obdo_cachep == NULL)
195                         GOTO(out, -ENOMEM);
196         }
197
198         if (export_cachep == NULL) {
199                 export_cachep = kmem_cache_create("export_cache",
200                                                 sizeof(struct obd_export),
201                                                 0, SLAB_HWCACHE_ALIGN,
202                                                 NULL, NULL);
203                 if (export_cachep == NULL)
204                         GOTO(out, -ENOMEM);
205         }
206
207         if (import_cachep == NULL) {
208                 import_cachep = kmem_cache_create("import_cache",
209                                                 sizeof(struct obd_import),
210                                                 0, SLAB_HWCACHE_ALIGN,
211                                                 NULL, NULL);
212                 if (import_cachep == NULL)
213                         GOTO(out, -ENOMEM);
214         }
215         RETURN(0);
216  out:
217         obd_cleanup_caches();
218         RETURN(-ENOMEM);
219
220 }
221
222 /* map connection to client */
223 struct obd_export *class_conn2export(struct lustre_handle *conn)
224 {
225         struct obd_export *export;
226
227         if (!conn) {
228                 CDEBUG(D_CACHE, "looking for null handle\n");
229                 RETURN(NULL);
230         }
231
232         if (conn->addr == -1) {  /* this means assign a new connection */
233                 CDEBUG(D_CACHE, "want a new connection\n");
234                 RETURN(NULL);
235         }
236
237         if (!conn->addr) {
238                 CDEBUG(D_CACHE, "looking for null addr\n");
239                 fixme();
240                 RETURN(NULL);
241         }
242
243         CDEBUG(D_IOCTL, "looking for export addr %Lx cookie %Lx\n",
244                conn->addr, conn->cookie);
245         export = (struct obd_export *) (unsigned long)conn->addr;
246         if (!kmem_cache_validate(export_cachep, (void *)export))
247                 RETURN(NULL);
248
249         if (export->exp_cookie != conn->cookie)
250                 return NULL;
251         return export;
252 } /* class_conn2export */
253
254 struct obd_device *class_conn2obd(struct lustre_handle *conn)
255 {
256         struct obd_export *export;
257         export = class_conn2export(conn);
258         if (export)
259                 return export->exp_obd;
260         fixme();
261         return NULL;
262 }
263
264 /* a connection defines an export context in which preallocation can
265    be managed. */
266 int class_connect (struct lustre_handle *conn, struct obd_device *obd)
267 {
268         struct obd_export * export;
269
270         if (conn == NULL) {
271                 LBUG();
272                 return -EINVAL;
273         }
274
275         if (obd == NULL) {
276                 LBUG();
277                 return -EINVAL;
278         }
279
280         export = kmem_cache_alloc(export_cachep, GFP_KERNEL);
281         if ( !export ) {
282                 CERROR("no memory! (minor %d)\n", obd->obd_minor);
283                 return -ENOMEM;
284         }
285
286         memset(export, 0, sizeof(*export));
287         get_random_bytes(&export->exp_cookie, sizeof(export->exp_cookie));
288         export->exp_obd = obd;
289         export->exp_rconnh.addr = conn->addr;
290         export->exp_rconnh.cookie = conn->cookie;
291
292         list_add(&(export->exp_chain), export->exp_obd->obd_exports.prev);
293         conn->addr = (__u64) (unsigned long)export;
294         conn->cookie = export->exp_cookie;
295         CDEBUG(D_IOCTL, "connect: addr %Lx cookie %Lx\n",
296                (long long)conn->addr, (long long)conn->cookie);
297         return 0;
298 }
299
300 int class_rconn2export(struct lustre_handle *conn, struct lustre_handle *rconn)
301 {
302         struct obd_export *export = class_conn2export(conn);
303
304         if (!export)
305                 return -EINVAL;
306
307         export->exp_rconnh.addr = rconn->addr;
308         export->exp_rconnh.cookie = rconn->cookie;
309
310         return 0;
311 }
312
313 int class_disconnect(struct lustre_handle *conn)
314 {
315         struct obd_export *export;
316         ENTRY;
317
318         if (!(export = class_conn2export(conn))) {
319                 fixme();
320                 CDEBUG(D_IOCTL, "disconnect: attempting to free "
321                        "nonexistent client %Lx\n", conn->addr);
322                 RETURN(-EINVAL);
323         } else
324                 CDEBUG(D_IOCTL, "disconnect: addr %Lx cookie %Lx\n",
325                        (long long)conn->addr, (long long)conn->cookie);
326         list_del(&export->exp_chain);
327         kmem_cache_free(export_cachep, export);
328
329         RETURN(0);
330 }
331
332 #if 0
333
334 /* FIXME: Data is a space- or comma-separated list of device IDs.  This will
335  * have to change. */
336 int class_multi_setup(struct obd_device *obddev, uint32_t len, void *data)
337 {
338         int count, rc;
339         char *p;
340         ENTRY;
341
342         for (p = data, count = 0; p < (char *)data + len; count++) {
343                 char *end;
344                 int tmp = simple_strtoul(p, &end, 0);
345
346                 if (p == end) {
347                         CERROR("invalid device ID starting at: %s\n", p);
348                         GOTO(err_disconnect, rc = -EINVAL);
349                 }
350
351                 if (tmp < 0 || tmp >= MAX_OBD_DEVICES) {
352                         CERROR("Trying to sub dev %d  - dev no too large\n",
353                                tmp);
354                         GOTO(err_disconnect, rc  = -EINVAL);
355                 }
356
357                 rc = obd_connect(&obddev->obd_multi_conn[count], &obd_dev[tmp]);
358                 if (rc) {
359                         CERROR("cannot connect to device %d: rc = %d\n", tmp,
360                                rc);
361                         GOTO(err_disconnect, rc);
362                 }
363
364                 CDEBUG(D_INFO, "target OBD %d is of type %s\n", count,
365                        obd_dev[tmp].obd_type->typ_name);
366
367                 p = end + 1;
368         }
369
370         obddev->obd_multi_count = count;
371
372         RETURN(0);
373
374  err_disconnect:
375         for (count--; count >= 0; count--)
376                 obd_disconnect(&obddev->obd_multi_conn[count]);
377         return rc;
378 }
379
380 /*
381  *    remove all connections to this device
382  *    close all connections to lower devices
383  *    needed for forced unloads of OBD client drivers
384  */
385 int class_multi_cleanup(struct obd_device *obddev)
386 {
387         int i;
388
389         for (i = 0; i < obddev->obd_multi_count; i++) {
390                 int rc;
391                 struct obd_device *obd = class_conn2obd(&obddev->obd_multi_conn[i]);
392
393                 if (!obd) {
394                         CERROR("no such device [i %d]\n", i);
395                         RETURN(-EINVAL);
396                 }
397
398                 rc = obd_disconnect(&obddev->obd_multi_conn[i]);
399                 if (rc)
400                         CERROR("disconnect failure %d\n", obd->obd_minor);
401         }
402         return 0;
403 }
404 #endif