1 /*******************************************************************************
2 * Filename: target_core_ua.c
3 *
4 * This file contains logic for SPC-3 Unit Attention emulation
5 *
6 * (c) Copyright 2009-2013 Datera, Inc.
7 *
8 * Nicholas A. Bellinger <nab@kernel.org>
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
23 *
24 ******************************************************************************/
25
26 #include <linux/slab.h>
27 #include <linux/spinlock.h>
28 #include <scsi/scsi.h>
29 #include <scsi/scsi_cmnd.h>
30
31 #include <target/target_core_base.h>
32 #include <target/target_core_fabric.h>
33 #include <target/target_core_configfs.h>
34
35 #include "target_core_internal.h"
36 #include "target_core_alua.h"
37 #include "target_core_pr.h"
38 #include "target_core_ua.h"
39
40 sense_reason_t
target_scsi3_ua_check(struct se_cmd * cmd)41 target_scsi3_ua_check(struct se_cmd *cmd)
42 {
43 struct se_dev_entry *deve;
44 struct se_session *sess = cmd->se_sess;
45 struct se_node_acl *nacl;
46
47 if (!sess)
48 return 0;
49
50 nacl = sess->se_node_acl;
51 if (!nacl)
52 return 0;
53
54 deve = nacl->device_list[cmd->orig_fe_lun];
55 if (!atomic_read(&deve->ua_count))
56 return 0;
57 /*
58 * From sam4r14, section 5.14 Unit attention condition:
59 *
60 * a) if an INQUIRY command enters the enabled command state, the
61 * device server shall process the INQUIRY command and shall neither
62 * report nor clear any unit attention condition;
63 * b) if a REPORT LUNS command enters the enabled command state, the
64 * device server shall process the REPORT LUNS command and shall not
65 * report any unit attention condition;
66 * e) if a REQUEST SENSE command enters the enabled command state while
67 * a unit attention condition exists for the SCSI initiator port
68 * associated with the I_T nexus on which the REQUEST SENSE command
69 * was received, then the device server shall process the command
70 * and either:
71 */
72 switch (cmd->t_task_cdb[0]) {
73 case INQUIRY:
74 case REPORT_LUNS:
75 case REQUEST_SENSE:
76 return 0;
77 default:
78 return TCM_CHECK_CONDITION_UNIT_ATTENTION;
79 }
80 }
81
core_scsi3_ua_allocate(struct se_node_acl * nacl,u32 unpacked_lun,u8 asc,u8 ascq)82 int core_scsi3_ua_allocate(
83 struct se_node_acl *nacl,
84 u32 unpacked_lun,
85 u8 asc,
86 u8 ascq)
87 {
88 struct se_dev_entry *deve;
89 struct se_ua *ua, *ua_p, *ua_tmp;
90 /*
91 * PASSTHROUGH OPS
92 */
93 if (!nacl)
94 return -EINVAL;
95
96 ua = kmem_cache_zalloc(se_ua_cache, GFP_ATOMIC);
97 if (!ua) {
98 pr_err("Unable to allocate struct se_ua\n");
99 return -ENOMEM;
100 }
101 INIT_LIST_HEAD(&ua->ua_nacl_list);
102
103 ua->ua_nacl = nacl;
104 ua->ua_asc = asc;
105 ua->ua_ascq = ascq;
106
107 spin_lock_irq(&nacl->device_list_lock);
108 deve = nacl->device_list[unpacked_lun];
109
110 spin_lock(&deve->ua_lock);
111 list_for_each_entry_safe(ua_p, ua_tmp, &deve->ua_list, ua_nacl_list) {
112 /*
113 * Do not report the same UNIT ATTENTION twice..
114 */
115 if ((ua_p->ua_asc == asc) && (ua_p->ua_ascq == ascq)) {
116 spin_unlock(&deve->ua_lock);
117 spin_unlock_irq(&nacl->device_list_lock);
118 kmem_cache_free(se_ua_cache, ua);
119 return 0;
120 }
121 /*
122 * Attach the highest priority Unit Attention to
123 * the head of the list following sam4r14,
124 * Section 5.14 Unit Attention Condition:
125 *
126 * POWER ON, RESET, OR BUS DEVICE RESET OCCURRED highest
127 * POWER ON OCCURRED or
128 * DEVICE INTERNAL RESET
129 * SCSI BUS RESET OCCURRED or
130 * MICROCODE HAS BEEN CHANGED or
131 * protocol specific
132 * BUS DEVICE RESET FUNCTION OCCURRED
133 * I_T NEXUS LOSS OCCURRED
134 * COMMANDS CLEARED BY POWER LOSS NOTIFICATION
135 * all others Lowest
136 *
137 * Each of the ASCQ codes listed above are defined in
138 * the 29h ASC family, see spc4r17 Table D.1
139 */
140 if (ua_p->ua_asc == 0x29) {
141 if ((asc == 0x29) && (ascq > ua_p->ua_ascq))
142 list_add(&ua->ua_nacl_list,
143 &deve->ua_list);
144 else
145 list_add_tail(&ua->ua_nacl_list,
146 &deve->ua_list);
147 } else if (ua_p->ua_asc == 0x2a) {
148 /*
149 * Incoming Family 29h ASCQ codes will override
150 * Family 2AHh ASCQ codes for Unit Attention condition.
151 */
152 if ((asc == 0x29) || (ascq > ua_p->ua_asc))
153 list_add(&ua->ua_nacl_list,
154 &deve->ua_list);
155 else
156 list_add_tail(&ua->ua_nacl_list,
157 &deve->ua_list);
158 } else
159 list_add_tail(&ua->ua_nacl_list,
160 &deve->ua_list);
161 spin_unlock(&deve->ua_lock);
162 spin_unlock_irq(&nacl->device_list_lock);
163
164 atomic_inc_mb(&deve->ua_count);
165 return 0;
166 }
167 list_add_tail(&ua->ua_nacl_list, &deve->ua_list);
168 spin_unlock(&deve->ua_lock);
169 spin_unlock_irq(&nacl->device_list_lock);
170
171 pr_debug("[%s]: Allocated UNIT ATTENTION, mapped LUN: %u, ASC:"
172 " 0x%02x, ASCQ: 0x%02x\n",
173 nacl->se_tpg->se_tpg_tfo->get_fabric_name(), unpacked_lun,
174 asc, ascq);
175
176 atomic_inc_mb(&deve->ua_count);
177 return 0;
178 }
179
core_scsi3_ua_release_all(struct se_dev_entry * deve)180 void core_scsi3_ua_release_all(
181 struct se_dev_entry *deve)
182 {
183 struct se_ua *ua, *ua_p;
184
185 spin_lock(&deve->ua_lock);
186 list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) {
187 list_del(&ua->ua_nacl_list);
188 kmem_cache_free(se_ua_cache, ua);
189
190 atomic_dec_mb(&deve->ua_count);
191 }
192 spin_unlock(&deve->ua_lock);
193 }
194
core_scsi3_ua_for_check_condition(struct se_cmd * cmd,u8 * asc,u8 * ascq)195 void core_scsi3_ua_for_check_condition(
196 struct se_cmd *cmd,
197 u8 *asc,
198 u8 *ascq)
199 {
200 struct se_device *dev = cmd->se_dev;
201 struct se_dev_entry *deve;
202 struct se_session *sess = cmd->se_sess;
203 struct se_node_acl *nacl;
204 struct se_ua *ua = NULL, *ua_p;
205 int head = 1;
206
207 if (!sess)
208 return;
209
210 nacl = sess->se_node_acl;
211 if (!nacl)
212 return;
213
214 spin_lock_irq(&nacl->device_list_lock);
215 deve = nacl->device_list[cmd->orig_fe_lun];
216 if (!atomic_read(&deve->ua_count)) {
217 spin_unlock_irq(&nacl->device_list_lock);
218 return;
219 }
220 /*
221 * The highest priority Unit Attentions are placed at the head of the
222 * struct se_dev_entry->ua_list, and will be returned in CHECK_CONDITION +
223 * sense data for the received CDB.
224 */
225 spin_lock(&deve->ua_lock);
226 list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) {
227 /*
228 * For ua_intlck_ctrl code not equal to 00b, only report the
229 * highest priority UNIT_ATTENTION and ASC/ASCQ without
230 * clearing it.
231 */
232 if (dev->dev_attrib.emulate_ua_intlck_ctrl != 0) {
233 *asc = ua->ua_asc;
234 *ascq = ua->ua_ascq;
235 break;
236 }
237 /*
238 * Otherwise for the default 00b, release the UNIT ATTENTION
239 * condition. Return the ASC/ASCQ of the highest priority UA
240 * (head of the list) in the outgoing CHECK_CONDITION + sense.
241 */
242 if (head) {
243 *asc = ua->ua_asc;
244 *ascq = ua->ua_ascq;
245 head = 0;
246 }
247 list_del(&ua->ua_nacl_list);
248 kmem_cache_free(se_ua_cache, ua);
249
250 atomic_dec_mb(&deve->ua_count);
251 }
252 spin_unlock(&deve->ua_lock);
253 spin_unlock_irq(&nacl->device_list_lock);
254
255 pr_debug("[%s]: %s UNIT ATTENTION condition with"
256 " INTLCK_CTRL: %d, mapped LUN: %u, got CDB: 0x%02x"
257 " reported ASC: 0x%02x, ASCQ: 0x%02x\n",
258 nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
259 (dev->dev_attrib.emulate_ua_intlck_ctrl != 0) ? "Reporting" :
260 "Releasing", dev->dev_attrib.emulate_ua_intlck_ctrl,
261 cmd->orig_fe_lun, cmd->t_task_cdb[0], *asc, *ascq);
262 }
263
core_scsi3_ua_clear_for_request_sense(struct se_cmd * cmd,u8 * asc,u8 * ascq)264 int core_scsi3_ua_clear_for_request_sense(
265 struct se_cmd *cmd,
266 u8 *asc,
267 u8 *ascq)
268 {
269 struct se_dev_entry *deve;
270 struct se_session *sess = cmd->se_sess;
271 struct se_node_acl *nacl;
272 struct se_ua *ua = NULL, *ua_p;
273 int head = 1;
274
275 if (!sess)
276 return -EINVAL;
277
278 nacl = sess->se_node_acl;
279 if (!nacl)
280 return -EINVAL;
281
282 spin_lock_irq(&nacl->device_list_lock);
283 deve = nacl->device_list[cmd->orig_fe_lun];
284 if (!atomic_read(&deve->ua_count)) {
285 spin_unlock_irq(&nacl->device_list_lock);
286 return -EPERM;
287 }
288 /*
289 * The highest priority Unit Attentions are placed at the head of the
290 * struct se_dev_entry->ua_list. The First (and hence highest priority)
291 * ASC/ASCQ will be returned in REQUEST_SENSE payload data for the
292 * matching struct se_lun.
293 *
294 * Once the returning ASC/ASCQ values are set, we go ahead and
295 * release all of the Unit Attention conditions for the associated
296 * struct se_lun.
297 */
298 spin_lock(&deve->ua_lock);
299 list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) {
300 if (head) {
301 *asc = ua->ua_asc;
302 *ascq = ua->ua_ascq;
303 head = 0;
304 }
305 list_del(&ua->ua_nacl_list);
306 kmem_cache_free(se_ua_cache, ua);
307
308 atomic_dec_mb(&deve->ua_count);
309 }
310 spin_unlock(&deve->ua_lock);
311 spin_unlock_irq(&nacl->device_list_lock);
312
313 pr_debug("[%s]: Released UNIT ATTENTION condition, mapped"
314 " LUN: %u, got REQUEST_SENSE reported ASC: 0x%02x,"
315 " ASCQ: 0x%02x\n", nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
316 cmd->orig_fe_lun, *asc, *ascq);
317
318 return (head) ? -EPERM : 0;
319 }
320