1 /*******************************************************************************
2 * Filename: target_core_ua.c
3 *
4 * This file contains logic for SPC-3 Unit Attention emulation
5 *
6 * Copyright (c) 2009,2010 Rising Tide Systems
7 * Copyright (c) 2009,2010 Linux-iSCSI.org
8 *
9 * Nicholas A. Bellinger <nab@kernel.org>
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
15 *
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
20 *
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
24 *
25 ******************************************************************************/
26
27 #include <linux/slab.h>
28 #include <linux/spinlock.h>
29 #include <scsi/scsi.h>
30 #include <scsi/scsi_cmnd.h>
31
32 #include <target/target_core_base.h>
33 #include <target/target_core_fabric.h>
34 #include <target/target_core_configfs.h>
35
36 #include "target_core_internal.h"
37 #include "target_core_alua.h"
38 #include "target_core_pr.h"
39 #include "target_core_ua.h"
40
core_scsi3_ua_check(struct se_cmd * cmd,unsigned char * cdb)41 int core_scsi3_ua_check(
42 struct se_cmd *cmd,
43 unsigned char *cdb)
44 {
45 struct se_dev_entry *deve;
46 struct se_session *sess = cmd->se_sess;
47 struct se_node_acl *nacl;
48
49 if (!sess)
50 return 0;
51
52 nacl = sess->se_node_acl;
53 if (!nacl)
54 return 0;
55
56 deve = nacl->device_list[cmd->orig_fe_lun];
57 if (!atomic_read(&deve->ua_count))
58 return 0;
59 /*
60 * From sam4r14, section 5.14 Unit attention condition:
61 *
62 * a) if an INQUIRY command enters the enabled command state, the
63 * device server shall process the INQUIRY command and shall neither
64 * report nor clear any unit attention condition;
65 * b) if a REPORT LUNS command enters the enabled command state, the
66 * device server shall process the REPORT LUNS command and shall not
67 * report any unit attention condition;
68 * e) if a REQUEST SENSE command enters the enabled command state while
69 * a unit attention condition exists for the SCSI initiator port
70 * associated with the I_T nexus on which the REQUEST SENSE command
71 * was received, then the device server shall process the command
72 * and either:
73 */
74 switch (cdb[0]) {
75 case INQUIRY:
76 case REPORT_LUNS:
77 case REQUEST_SENSE:
78 return 0;
79 default:
80 return -EINVAL;
81 }
82
83 return -EINVAL;
84 }
85
core_scsi3_ua_allocate(struct se_node_acl * nacl,u32 unpacked_lun,u8 asc,u8 ascq)86 int core_scsi3_ua_allocate(
87 struct se_node_acl *nacl,
88 u32 unpacked_lun,
89 u8 asc,
90 u8 ascq)
91 {
92 struct se_dev_entry *deve;
93 struct se_ua *ua, *ua_p, *ua_tmp;
94 /*
95 * PASSTHROUGH OPS
96 */
97 if (!nacl)
98 return -EINVAL;
99
100 ua = kmem_cache_zalloc(se_ua_cache, GFP_ATOMIC);
101 if (!ua) {
102 pr_err("Unable to allocate struct se_ua\n");
103 return -ENOMEM;
104 }
105 INIT_LIST_HEAD(&ua->ua_dev_list);
106 INIT_LIST_HEAD(&ua->ua_nacl_list);
107
108 ua->ua_nacl = nacl;
109 ua->ua_asc = asc;
110 ua->ua_ascq = ascq;
111
112 spin_lock_irq(&nacl->device_list_lock);
113 deve = nacl->device_list[unpacked_lun];
114
115 spin_lock(&deve->ua_lock);
116 list_for_each_entry_safe(ua_p, ua_tmp, &deve->ua_list, ua_nacl_list) {
117 /*
118 * Do not report the same UNIT ATTENTION twice..
119 */
120 if ((ua_p->ua_asc == asc) && (ua_p->ua_ascq == ascq)) {
121 spin_unlock(&deve->ua_lock);
122 spin_unlock_irq(&nacl->device_list_lock);
123 kmem_cache_free(se_ua_cache, ua);
124 return 0;
125 }
126 /*
127 * Attach the highest priority Unit Attention to
128 * the head of the list following sam4r14,
129 * Section 5.14 Unit Attention Condition:
130 *
131 * POWER ON, RESET, OR BUS DEVICE RESET OCCURRED highest
132 * POWER ON OCCURRED or
133 * DEVICE INTERNAL RESET
134 * SCSI BUS RESET OCCURRED or
135 * MICROCODE HAS BEEN CHANGED or
136 * protocol specific
137 * BUS DEVICE RESET FUNCTION OCCURRED
138 * I_T NEXUS LOSS OCCURRED
139 * COMMANDS CLEARED BY POWER LOSS NOTIFICATION
140 * all others Lowest
141 *
142 * Each of the ASCQ codes listed above are defined in
143 * the 29h ASC family, see spc4r17 Table D.1
144 */
145 if (ua_p->ua_asc == 0x29) {
146 if ((asc == 0x29) && (ascq > ua_p->ua_ascq))
147 list_add(&ua->ua_nacl_list,
148 &deve->ua_list);
149 else
150 list_add_tail(&ua->ua_nacl_list,
151 &deve->ua_list);
152 } else if (ua_p->ua_asc == 0x2a) {
153 /*
154 * Incoming Family 29h ASCQ codes will override
155 * Family 2AHh ASCQ codes for Unit Attention condition.
156 */
157 if ((asc == 0x29) || (ascq > ua_p->ua_asc))
158 list_add(&ua->ua_nacl_list,
159 &deve->ua_list);
160 else
161 list_add_tail(&ua->ua_nacl_list,
162 &deve->ua_list);
163 } else
164 list_add_tail(&ua->ua_nacl_list,
165 &deve->ua_list);
166 spin_unlock(&deve->ua_lock);
167 spin_unlock_irq(&nacl->device_list_lock);
168
169 atomic_inc(&deve->ua_count);
170 smp_mb__after_atomic_inc();
171 return 0;
172 }
173 list_add_tail(&ua->ua_nacl_list, &deve->ua_list);
174 spin_unlock(&deve->ua_lock);
175 spin_unlock_irq(&nacl->device_list_lock);
176
177 pr_debug("[%s]: Allocated UNIT ATTENTION, mapped LUN: %u, ASC:"
178 " 0x%02x, ASCQ: 0x%02x\n",
179 nacl->se_tpg->se_tpg_tfo->get_fabric_name(), unpacked_lun,
180 asc, ascq);
181
182 atomic_inc(&deve->ua_count);
183 smp_mb__after_atomic_inc();
184 return 0;
185 }
186
core_scsi3_ua_release_all(struct se_dev_entry * deve)187 void core_scsi3_ua_release_all(
188 struct se_dev_entry *deve)
189 {
190 struct se_ua *ua, *ua_p;
191
192 spin_lock(&deve->ua_lock);
193 list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) {
194 list_del(&ua->ua_nacl_list);
195 kmem_cache_free(se_ua_cache, ua);
196
197 atomic_dec(&deve->ua_count);
198 smp_mb__after_atomic_dec();
199 }
200 spin_unlock(&deve->ua_lock);
201 }
202
core_scsi3_ua_for_check_condition(struct se_cmd * cmd,u8 * asc,u8 * ascq)203 void core_scsi3_ua_for_check_condition(
204 struct se_cmd *cmd,
205 u8 *asc,
206 u8 *ascq)
207 {
208 struct se_device *dev = cmd->se_dev;
209 struct se_dev_entry *deve;
210 struct se_session *sess = cmd->se_sess;
211 struct se_node_acl *nacl;
212 struct se_ua *ua = NULL, *ua_p;
213 int head = 1;
214
215 if (!sess)
216 return;
217
218 nacl = sess->se_node_acl;
219 if (!nacl)
220 return;
221
222 spin_lock_irq(&nacl->device_list_lock);
223 deve = nacl->device_list[cmd->orig_fe_lun];
224 if (!atomic_read(&deve->ua_count)) {
225 spin_unlock_irq(&nacl->device_list_lock);
226 return;
227 }
228 /*
229 * The highest priority Unit Attentions are placed at the head of the
230 * struct se_dev_entry->ua_list, and will be returned in CHECK_CONDITION +
231 * sense data for the received CDB.
232 */
233 spin_lock(&deve->ua_lock);
234 list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) {
235 /*
236 * For ua_intlck_ctrl code not equal to 00b, only report the
237 * highest priority UNIT_ATTENTION and ASC/ASCQ without
238 * clearing it.
239 */
240 if (dev->se_sub_dev->se_dev_attrib.emulate_ua_intlck_ctrl != 0) {
241 *asc = ua->ua_asc;
242 *ascq = ua->ua_ascq;
243 break;
244 }
245 /*
246 * Otherwise for the default 00b, release the UNIT ATTENTION
247 * condition. Return the ASC/ASCQ of the highest priority UA
248 * (head of the list) in the outgoing CHECK_CONDITION + sense.
249 */
250 if (head) {
251 *asc = ua->ua_asc;
252 *ascq = ua->ua_ascq;
253 head = 0;
254 }
255 list_del(&ua->ua_nacl_list);
256 kmem_cache_free(se_ua_cache, ua);
257
258 atomic_dec(&deve->ua_count);
259 smp_mb__after_atomic_dec();
260 }
261 spin_unlock(&deve->ua_lock);
262 spin_unlock_irq(&nacl->device_list_lock);
263
264 pr_debug("[%s]: %s UNIT ATTENTION condition with"
265 " INTLCK_CTRL: %d, mapped LUN: %u, got CDB: 0x%02x"
266 " reported ASC: 0x%02x, ASCQ: 0x%02x\n",
267 nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
268 (dev->se_sub_dev->se_dev_attrib.emulate_ua_intlck_ctrl != 0) ? "Reporting" :
269 "Releasing", dev->se_sub_dev->se_dev_attrib.emulate_ua_intlck_ctrl,
270 cmd->orig_fe_lun, cmd->t_task_cdb[0], *asc, *ascq);
271 }
272
core_scsi3_ua_clear_for_request_sense(struct se_cmd * cmd,u8 * asc,u8 * ascq)273 int core_scsi3_ua_clear_for_request_sense(
274 struct se_cmd *cmd,
275 u8 *asc,
276 u8 *ascq)
277 {
278 struct se_dev_entry *deve;
279 struct se_session *sess = cmd->se_sess;
280 struct se_node_acl *nacl;
281 struct se_ua *ua = NULL, *ua_p;
282 int head = 1;
283
284 if (!sess)
285 return -EINVAL;
286
287 nacl = sess->se_node_acl;
288 if (!nacl)
289 return -EINVAL;
290
291 spin_lock_irq(&nacl->device_list_lock);
292 deve = nacl->device_list[cmd->orig_fe_lun];
293 if (!atomic_read(&deve->ua_count)) {
294 spin_unlock_irq(&nacl->device_list_lock);
295 return -EPERM;
296 }
297 /*
298 * The highest priority Unit Attentions are placed at the head of the
299 * struct se_dev_entry->ua_list. The First (and hence highest priority)
300 * ASC/ASCQ will be returned in REQUEST_SENSE payload data for the
301 * matching struct se_lun.
302 *
303 * Once the returning ASC/ASCQ values are set, we go ahead and
304 * release all of the Unit Attention conditions for the associated
305 * struct se_lun.
306 */
307 spin_lock(&deve->ua_lock);
308 list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) {
309 if (head) {
310 *asc = ua->ua_asc;
311 *ascq = ua->ua_ascq;
312 head = 0;
313 }
314 list_del(&ua->ua_nacl_list);
315 kmem_cache_free(se_ua_cache, ua);
316
317 atomic_dec(&deve->ua_count);
318 smp_mb__after_atomic_dec();
319 }
320 spin_unlock(&deve->ua_lock);
321 spin_unlock_irq(&nacl->device_list_lock);
322
323 pr_debug("[%s]: Released UNIT ATTENTION condition, mapped"
324 " LUN: %u, got REQUEST_SENSE reported ASC: 0x%02x,"
325 " ASCQ: 0x%02x\n", nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
326 cmd->orig_fe_lun, *asc, *ascq);
327
328 return (head) ? -EPERM : 0;
329 }
330