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 (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
24 */
25
26 #include <sys/types.h>
27 #include <sys/errno.h>
28 #include <sys/cmn_err.h>
29 #include <sys/ksynch.h>
30 #include <sys/kmem.h>
31 #include <sys/ddi.h>
32
33 #define __NSC_GEN__
34 #include "nsc_dev.h"
35 #include "../nsctl.h"
36
37 /*
38 * (Un)Freeze Module
39 *
40 * This module provides a means to 'freeze' a device and ensure
41 * that no SP software has an open reference to that device. Later
42 * the device can be 'unfrozen' and the SP software can resume
43 * normal operations.
44 *
45 * This module is required because it is possible to place a virtual
46 * volume driver (RAID-0, 1 or 5) into a state whereby it needs to be
47 * disabled for corrective action. The (un)freeze facility provides a
48 * method of doing this without downtime.
49 *
50 * A device that is frozen should be frozen on all nodes. It is the
51 * responsibility of the management software or the user to perform
52 * the freeze and unfreeze on the required nodes.
53 */
54
55 extern nsc_mem_t *_nsc_local_mem;
56
57 typedef struct _nsc_frz_s {
58 struct _nsc_frz_s *next;
59 nsc_path_t *token;
60 char path[NSC_MAXPATH];
61 } _nsc_frz_t;
62
63
64 extern int _nsc_frz_stop(char *, int *); /* forward decl */
65
66 static _nsc_frz_t *_nsc_frz_top;
67 static nsc_def_t _nsc_frz_def[];
68 static kmutex_t _nsc_frz_sleep;
69 static nsc_io_t *_nsc_frz_io;
70
71
72 void
73 _nsc_init_frz(void)
74 {
75 mutex_init(&_nsc_frz_sleep, NULL, MUTEX_DRIVER, NULL);
76
77 _nsc_frz_io = nsc_register_io("frz",
78 NSC_FREEZE_ID | NSC_FILTER, _nsc_frz_def);
79
80 if (!_nsc_frz_io)
81 cmn_err(CE_WARN, "nsctl: _nsc_init_frz: register failed");
82 }
83
84
85 void
86 _nsc_deinit_frz(void)
87 {
88 if (_nsc_frz_io)
89 (void) nsc_unregister_io(_nsc_frz_io, 0);
90
91 _nsc_frz_io = NULL;
92
93 mutex_destroy(&_nsc_frz_sleep);
94 }
95
96
97 /*
98 * int _nsc_frz_start(char *path, int *rvp)
99 * Freeze a device
100 *
101 * Calling/Exit State:
102 * Must be called from a context that can block.
103 * Returns 0 for success, or one of the following error codes:
104 * EINVAL - invalid 'path' argument
105 * ENOMEM - failed to allocate memory
106 * EALREADY - 'path' is already frozen
107 *
108 * Description:
109 * Registers 'path' to be accessed through the NSC_FREEZE_ID
110 * io module, and forces any open file descriptors for 'path'
111 * to be re-opened as appropriate.
112 */
113 int
114 _nsc_frz_start(path, rvp)
115 char *path;
116 int *rvp;
117 {
118 _nsc_frz_t *frz, *xfrz;
119 int rc;
120
121 *rvp = 0;
122
123 if (strlen(path) >= NSC_MAXPATH)
124 return (EINVAL);
125
126 frz = nsc_kmem_zalloc(sizeof (*frz), KM_SLEEP, _nsc_local_mem);
127 if (!frz)
128 return (ENOMEM);
129
130 (void) strcpy(frz->path, path);
131
132 mutex_enter(&_nsc_frz_sleep);
133
134 for (xfrz = _nsc_frz_top; xfrz; xfrz = xfrz->next)
135 if (strcmp(frz->path, xfrz->path) == 0)
136 break;
137
138 if (!xfrz) {
139 frz->next = _nsc_frz_top;
140 _nsc_frz_top = frz;
141 }
142
143 mutex_exit(&_nsc_frz_sleep);
144
145 if (xfrz) {
146 nsc_kmem_free(frz, sizeof (*frz));
147 return (EALREADY);
148 }
149
150 frz->token = nsc_register_path(path, NSC_DEVICE, _nsc_frz_io);
151
152 if (!frz->token) {
153 (void) _nsc_frz_stop(path, &rc);
154 return (EINVAL);
155 }
156
157 return (0);
158 }
159
160
161 /*
162 * int _nsc_frz_stop(char *path, int *rvp)
163 * Unfreeze a device
164 *
165 * Calling/Exit State:
166 * Must be called from a context that can block.
167 * Returns 0 or an error code.
168 *
169 * Description:
170 * Removes the path registration for the NSC_FREEZE_ID io module
171 * and forces any re-opens as appropriate.
172 */
173 int
174 _nsc_frz_stop(path, rvp)
175 char *path;
176 int *rvp;
177 {
178 _nsc_frz_t **xfrz, *frz = NULL;
179 int rc = 0;
180
181 *rvp = 0;
182
183 mutex_enter(&_nsc_frz_sleep);
184
185 for (xfrz = &_nsc_frz_top; *xfrz; xfrz = &(*xfrz)->next)
186 if (strcmp(path, (*xfrz)->path) == 0) {
187 frz = *xfrz;
188 break;
189 }
190
191 if (!frz) {
192 mutex_exit(&_nsc_frz_sleep);
193 return (EINVAL);
194 }
195
196 if (frz->token)
197 rc = nsc_unregister_path(frz->token, NSC_PCATCH);
198
199 if (rc) {
200 mutex_exit(&_nsc_frz_sleep);
201 return (rc);
202 }
203
204 (*xfrz) = frz->next;
205
206 mutex_exit(&_nsc_frz_sleep);
207
208 nsc_kmem_free(frz, sizeof (*frz));
209
210 return (0);
211 }
212
213
214 /*
215 * int _nsc_frz_isfrozen(char *path, int *rvp)
216 * Tests whether a device is frozen.
217 *
218 * Calling/Exit State:
219 * Returns 0 or EINVAL.
220 * Sets *rvp to 1 if the device was not frozen, and 0 otherwise.
221 * This function returns historical information.
222 */
223 int
224 _nsc_frz_isfrozen(path, rvp)
225 char *path;
226 int *rvp;
227 {
228 _nsc_frz_t *frz;
229
230 *rvp = 1;
231
232 if (! _nsc_frz_io)
233 return (EINVAL);
234
235 mutex_enter(&_nsc_frz_sleep);
236
237 for (frz = _nsc_frz_top; frz; frz = frz->next)
238 if (strcmp(frz->path, path) == 0) {
239 *rvp = 0;
240 break;
241 }
242
243 mutex_exit(&_nsc_frz_sleep);
244
245 return (0);
246 }
247
248
249 /*
250 * static int
251 * _nsc_frz_open(char *path, int flag, blind_t *cdp)
252 * Dummy open function.
253 *
254 * Description:
255 * This is the "Open" function for the I/O module.
256 * It is just a dummy.
257 */
258
259 /* ARGSUSED */
260
261 static int
262 _nsc_frz_open(path, flag, cdp)
263 char *path;
264 int flag;
265 blind_t *cdp;
266 {
267 *cdp = 0;
268 return (0);
269 }
270
271
272 /*
273 * static int
274 * _nsc_frz_close()
275 * Dummy close function.
276 *
277 * Description:
278 * This is the "Close" function for the I/O module.
279 * It is just a dummy.
280 */
281 static int
282 _nsc_frz_close() { return (0); }
283
284
285 /*
286 * static int
287 * _nsc_frz_attach()
288 * Attach a device to this i/o module.
289 *
290 * Calling/Exit State:
291 * Returns EACCES in all cricumstances.
292 *
293 * Description:
294 * This function is called by the nsctl module when it wishes
295 * to attach the device to this I/O module (ie. as part of
296 * nsc_reserve() processing). This function unconditionally
297 * returns an error which forces the nsc_reserve() to fail, and
298 * so no access to possible to the underlying device.
299 */
300 static int
301 _nsc_frz_attach() { return (EACCES); }
302
303
304 static nsc_def_t _nsc_frz_def[] = {
305 "Open", (uintptr_t)_nsc_frz_open, 0,
306 "Close", (uintptr_t)_nsc_frz_close, 0,
307 "Attach", (uintptr_t)_nsc_frz_attach, 0,
308 "Provide", 0, 0,
309 0, 0, 0
310 };