Root/drivers/target/target_core_ua.c

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
41int 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
86int 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
187void 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
203void 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
273int 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

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