Merge tag 'vfio-ccw-20170724' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms39...
[sfrench/cifs-2.6.git] / drivers / target / target_core_alua.c
1 /*******************************************************************************
2  * Filename:  target_core_alua.c
3  *
4  * This file contains SPC-3 compliant asymmetric logical unit assigntment (ALUA)
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 <linux/configfs.h>
29 #include <linux/delay.h>
30 #include <linux/export.h>
31 #include <linux/fcntl.h>
32 #include <linux/file.h>
33 #include <linux/fs.h>
34 #include <scsi/scsi_proto.h>
35 #include <asm/unaligned.h>
36
37 #include <target/target_core_base.h>
38 #include <target/target_core_backend.h>
39 #include <target/target_core_fabric.h>
40
41 #include "target_core_internal.h"
42 #include "target_core_alua.h"
43 #include "target_core_ua.h"
44
45 static sense_reason_t core_alua_check_transition(int state, int valid,
46                                                  int *primary, int explicit);
47 static int core_alua_set_tg_pt_secondary_state(
48                 struct se_lun *lun, int explicit, int offline);
49
50 static char *core_alua_dump_state(int state);
51
52 static void __target_attach_tg_pt_gp(struct se_lun *lun,
53                 struct t10_alua_tg_pt_gp *tg_pt_gp);
54
55 static u16 alua_lu_gps_counter;
56 static u32 alua_lu_gps_count;
57
58 static DEFINE_SPINLOCK(lu_gps_lock);
59 static LIST_HEAD(lu_gps_list);
60
61 struct t10_alua_lu_gp *default_lu_gp;
62
63 /*
64  * REPORT REFERRALS
65  *
66  * See sbc3r35 section 5.23
67  */
68 sense_reason_t
69 target_emulate_report_referrals(struct se_cmd *cmd)
70 {
71         struct se_device *dev = cmd->se_dev;
72         struct t10_alua_lba_map *map;
73         struct t10_alua_lba_map_member *map_mem;
74         unsigned char *buf;
75         u32 rd_len = 0, off;
76
77         if (cmd->data_length < 4) {
78                 pr_warn("REPORT REFERRALS allocation length %u too"
79                         " small\n", cmd->data_length);
80                 return TCM_INVALID_CDB_FIELD;
81         }
82
83         buf = transport_kmap_data_sg(cmd);
84         if (!buf)
85                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
86
87         off = 4;
88         spin_lock(&dev->t10_alua.lba_map_lock);
89         if (list_empty(&dev->t10_alua.lba_map_list)) {
90                 spin_unlock(&dev->t10_alua.lba_map_lock);
91                 transport_kunmap_data_sg(cmd);
92
93                 return TCM_UNSUPPORTED_SCSI_OPCODE;
94         }
95
96         list_for_each_entry(map, &dev->t10_alua.lba_map_list,
97                             lba_map_list) {
98                 int desc_num = off + 3;
99                 int pg_num;
100
101                 off += 4;
102                 if (cmd->data_length > off)
103                         put_unaligned_be64(map->lba_map_first_lba, &buf[off]);
104                 off += 8;
105                 if (cmd->data_length > off)
106                         put_unaligned_be64(map->lba_map_last_lba, &buf[off]);
107                 off += 8;
108                 rd_len += 20;
109                 pg_num = 0;
110                 list_for_each_entry(map_mem, &map->lba_map_mem_list,
111                                     lba_map_mem_list) {
112                         int alua_state = map_mem->lba_map_mem_alua_state;
113                         int alua_pg_id = map_mem->lba_map_mem_alua_pg_id;
114
115                         if (cmd->data_length > off)
116                                 buf[off] = alua_state & 0x0f;
117                         off += 2;
118                         if (cmd->data_length > off)
119                                 buf[off] = (alua_pg_id >> 8) & 0xff;
120                         off++;
121                         if (cmd->data_length > off)
122                                 buf[off] = (alua_pg_id & 0xff);
123                         off++;
124                         rd_len += 4;
125                         pg_num++;
126                 }
127                 if (cmd->data_length > desc_num)
128                         buf[desc_num] = pg_num;
129         }
130         spin_unlock(&dev->t10_alua.lba_map_lock);
131
132         /*
133          * Set the RETURN DATA LENGTH set in the header of the DataIN Payload
134          */
135         put_unaligned_be16(rd_len, &buf[2]);
136
137         transport_kunmap_data_sg(cmd);
138
139         target_complete_cmd(cmd, GOOD);
140         return 0;
141 }
142
143 /*
144  * REPORT_TARGET_PORT_GROUPS
145  *
146  * See spc4r17 section 6.27
147  */
148 sense_reason_t
149 target_emulate_report_target_port_groups(struct se_cmd *cmd)
150 {
151         struct se_device *dev = cmd->se_dev;
152         struct t10_alua_tg_pt_gp *tg_pt_gp;
153         struct se_lun *lun;
154         unsigned char *buf;
155         u32 rd_len = 0, off;
156         int ext_hdr = (cmd->t_task_cdb[1] & 0x20);
157
158         /*
159          * Skip over RESERVED area to first Target port group descriptor
160          * depending on the PARAMETER DATA FORMAT type..
161          */
162         if (ext_hdr != 0)
163                 off = 8;
164         else
165                 off = 4;
166
167         if (cmd->data_length < off) {
168                 pr_warn("REPORT TARGET PORT GROUPS allocation length %u too"
169                         " small for %s header\n", cmd->data_length,
170                         (ext_hdr) ? "extended" : "normal");
171                 return TCM_INVALID_CDB_FIELD;
172         }
173         buf = transport_kmap_data_sg(cmd);
174         if (!buf)
175                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
176
177         spin_lock(&dev->t10_alua.tg_pt_gps_lock);
178         list_for_each_entry(tg_pt_gp, &dev->t10_alua.tg_pt_gps_list,
179                         tg_pt_gp_list) {
180                 /*
181                  * Check if the Target port group and Target port descriptor list
182                  * based on tg_pt_gp_members count will fit into the response payload.
183                  * Otherwise, bump rd_len to let the initiator know we have exceeded
184                  * the allocation length and the response is truncated.
185                  */
186                 if ((off + 8 + (tg_pt_gp->tg_pt_gp_members * 4)) >
187                      cmd->data_length) {
188                         rd_len += 8 + (tg_pt_gp->tg_pt_gp_members * 4);
189                         continue;
190                 }
191                 /*
192                  * PREF: Preferred target port bit, determine if this
193                  * bit should be set for port group.
194                  */
195                 if (tg_pt_gp->tg_pt_gp_pref)
196                         buf[off] = 0x80;
197                 /*
198                  * Set the ASYMMETRIC ACCESS State
199                  */
200                 buf[off++] |= tg_pt_gp->tg_pt_gp_alua_access_state & 0xff;
201                 /*
202                  * Set supported ASYMMETRIC ACCESS State bits
203                  */
204                 buf[off++] |= tg_pt_gp->tg_pt_gp_alua_supported_states;
205                 /*
206                  * TARGET PORT GROUP
207                  */
208                 put_unaligned_be16(tg_pt_gp->tg_pt_gp_id, &buf[off]);
209                 off += 2;
210
211                 off++; /* Skip over Reserved */
212                 /*
213                  * STATUS CODE
214                  */
215                 buf[off++] = (tg_pt_gp->tg_pt_gp_alua_access_status & 0xff);
216                 /*
217                  * Vendor Specific field
218                  */
219                 buf[off++] = 0x00;
220                 /*
221                  * TARGET PORT COUNT
222                  */
223                 buf[off++] = (tg_pt_gp->tg_pt_gp_members & 0xff);
224                 rd_len += 8;
225
226                 spin_lock(&tg_pt_gp->tg_pt_gp_lock);
227                 list_for_each_entry(lun, &tg_pt_gp->tg_pt_gp_lun_list,
228                                 lun_tg_pt_gp_link) {
229                         /*
230                          * Start Target Port descriptor format
231                          *
232                          * See spc4r17 section 6.2.7 Table 247
233                          */
234                         off += 2; /* Skip over Obsolete */
235                         /*
236                          * Set RELATIVE TARGET PORT IDENTIFIER
237                          */
238                         put_unaligned_be16(lun->lun_rtpi, &buf[off]);
239                         off += 2;
240                         rd_len += 4;
241                 }
242                 spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
243         }
244         spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
245         /*
246          * Set the RETURN DATA LENGTH set in the header of the DataIN Payload
247          */
248         put_unaligned_be32(rd_len, &buf[0]);
249
250         /*
251          * Fill in the Extended header parameter data format if requested
252          */
253         if (ext_hdr != 0) {
254                 buf[4] = 0x10;
255                 /*
256                  * Set the implicit transition time (in seconds) for the application
257                  * client to use as a base for it's transition timeout value.
258                  *
259                  * Use the current tg_pt_gp_mem -> tg_pt_gp membership from the LUN
260                  * this CDB was received upon to determine this value individually
261                  * for ALUA target port group.
262                  */
263                 spin_lock(&cmd->se_lun->lun_tg_pt_gp_lock);
264                 tg_pt_gp = cmd->se_lun->lun_tg_pt_gp;
265                 if (tg_pt_gp)
266                         buf[5] = tg_pt_gp->tg_pt_gp_implicit_trans_secs;
267                 spin_unlock(&cmd->se_lun->lun_tg_pt_gp_lock);
268         }
269         transport_kunmap_data_sg(cmd);
270
271         target_complete_cmd(cmd, GOOD);
272         return 0;
273 }
274
275 /*
276  * SET_TARGET_PORT_GROUPS for explicit ALUA operation.
277  *
278  * See spc4r17 section 6.35
279  */
280 sense_reason_t
281 target_emulate_set_target_port_groups(struct se_cmd *cmd)
282 {
283         struct se_device *dev = cmd->se_dev;
284         struct se_lun *l_lun = cmd->se_lun;
285         struct se_node_acl *nacl = cmd->se_sess->se_node_acl;
286         struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *l_tg_pt_gp;
287         unsigned char *buf;
288         unsigned char *ptr;
289         sense_reason_t rc = TCM_NO_SENSE;
290         u32 len = 4; /* Skip over RESERVED area in header */
291         int alua_access_state, primary = 0, valid_states;
292         u16 tg_pt_id, rtpi;
293
294         if (cmd->data_length < 4) {
295                 pr_warn("SET TARGET PORT GROUPS parameter list length %u too"
296                         " small\n", cmd->data_length);
297                 return TCM_INVALID_PARAMETER_LIST;
298         }
299
300         buf = transport_kmap_data_sg(cmd);
301         if (!buf)
302                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
303
304         /*
305          * Determine if explicit ALUA via SET_TARGET_PORT_GROUPS is allowed
306          * for the local tg_pt_gp.
307          */
308         spin_lock(&l_lun->lun_tg_pt_gp_lock);
309         l_tg_pt_gp = l_lun->lun_tg_pt_gp;
310         if (!l_tg_pt_gp) {
311                 spin_unlock(&l_lun->lun_tg_pt_gp_lock);
312                 pr_err("Unable to access l_lun->tg_pt_gp\n");
313                 rc = TCM_UNSUPPORTED_SCSI_OPCODE;
314                 goto out;
315         }
316
317         if (!(l_tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICIT_ALUA)) {
318                 spin_unlock(&l_lun->lun_tg_pt_gp_lock);
319                 pr_debug("Unable to process SET_TARGET_PORT_GROUPS"
320                                 " while TPGS_EXPLICIT_ALUA is disabled\n");
321                 rc = TCM_UNSUPPORTED_SCSI_OPCODE;
322                 goto out;
323         }
324         valid_states = l_tg_pt_gp->tg_pt_gp_alua_supported_states;
325         spin_unlock(&l_lun->lun_tg_pt_gp_lock);
326
327         ptr = &buf[4]; /* Skip over RESERVED area in header */
328
329         while (len < cmd->data_length) {
330                 bool found = false;
331                 alua_access_state = (ptr[0] & 0x0f);
332                 /*
333                  * Check the received ALUA access state, and determine if
334                  * the state is a primary or secondary target port asymmetric
335                  * access state.
336                  */
337                 rc = core_alua_check_transition(alua_access_state, valid_states,
338                                                 &primary, 1);
339                 if (rc) {
340                         /*
341                          * If the SET TARGET PORT GROUPS attempts to establish
342                          * an invalid combination of target port asymmetric
343                          * access states or attempts to establish an
344                          * unsupported target port asymmetric access state,
345                          * then the command shall be terminated with CHECK
346                          * CONDITION status, with the sense key set to ILLEGAL
347                          * REQUEST, and the additional sense code set to INVALID
348                          * FIELD IN PARAMETER LIST.
349                          */
350                         goto out;
351                 }
352
353                 /*
354                  * If the ASYMMETRIC ACCESS STATE field (see table 267)
355                  * specifies a primary target port asymmetric access state,
356                  * then the TARGET PORT GROUP OR TARGET PORT field specifies
357                  * a primary target port group for which the primary target
358                  * port asymmetric access state shall be changed. If the
359                  * ASYMMETRIC ACCESS STATE field specifies a secondary target
360                  * port asymmetric access state, then the TARGET PORT GROUP OR
361                  * TARGET PORT field specifies the relative target port
362                  * identifier (see 3.1.120) of the target port for which the
363                  * secondary target port asymmetric access state shall be
364                  * changed.
365                  */
366                 if (primary) {
367                         tg_pt_id = get_unaligned_be16(ptr + 2);
368                         /*
369                          * Locate the matching target port group ID from
370                          * the global tg_pt_gp list
371                          */
372                         spin_lock(&dev->t10_alua.tg_pt_gps_lock);
373                         list_for_each_entry(tg_pt_gp,
374                                         &dev->t10_alua.tg_pt_gps_list,
375                                         tg_pt_gp_list) {
376                                 if (!tg_pt_gp->tg_pt_gp_valid_id)
377                                         continue;
378
379                                 if (tg_pt_id != tg_pt_gp->tg_pt_gp_id)
380                                         continue;
381
382                                 atomic_inc_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);
383
384                                 spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
385
386                                 if (!core_alua_do_port_transition(tg_pt_gp,
387                                                 dev, l_lun, nacl,
388                                                 alua_access_state, 1))
389                                         found = true;
390
391                                 spin_lock(&dev->t10_alua.tg_pt_gps_lock);
392                                 atomic_dec_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);
393                                 break;
394                         }
395                         spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
396                 } else {
397                         struct se_lun *lun;
398
399                         /*
400                          * Extract the RELATIVE TARGET PORT IDENTIFIER to identify
401                          * the Target Port in question for the the incoming
402                          * SET_TARGET_PORT_GROUPS op.
403                          */
404                         rtpi = get_unaligned_be16(ptr + 2);
405                         /*
406                          * Locate the matching relative target port identifier
407                          * for the struct se_device storage object.
408                          */
409                         spin_lock(&dev->se_port_lock);
410                         list_for_each_entry(lun, &dev->dev_sep_list,
411                                                         lun_dev_link) {
412                                 if (lun->lun_rtpi != rtpi)
413                                         continue;
414
415                                 // XXX: racy unlock
416                                 spin_unlock(&dev->se_port_lock);
417
418                                 if (!core_alua_set_tg_pt_secondary_state(
419                                                 lun, 1, 1))
420                                         found = true;
421
422                                 spin_lock(&dev->se_port_lock);
423                                 break;
424                         }
425                         spin_unlock(&dev->se_port_lock);
426                 }
427
428                 if (!found) {
429                         rc = TCM_INVALID_PARAMETER_LIST;
430                         goto out;
431                 }
432
433                 ptr += 4;
434                 len += 4;
435         }
436
437 out:
438         transport_kunmap_data_sg(cmd);
439         if (!rc)
440                 target_complete_cmd(cmd, GOOD);
441         return rc;
442 }
443
444 static inline void set_ascq(struct se_cmd *cmd, u8 alua_ascq)
445 {
446         /*
447          * Set SCSI additional sense code (ASC) to 'LUN Not Accessible';
448          * The ALUA additional sense code qualifier (ASCQ) is determined
449          * by the ALUA primary or secondary access state..
450          */
451         pr_debug("[%s]: ALUA TG Port not available, "
452                 "SenseKey: NOT_READY, ASC/ASCQ: "
453                 "0x04/0x%02x\n",
454                 cmd->se_tfo->get_fabric_name(), alua_ascq);
455
456         cmd->scsi_asc = 0x04;
457         cmd->scsi_ascq = alua_ascq;
458 }
459
460 static inline void core_alua_state_nonoptimized(
461         struct se_cmd *cmd,
462         unsigned char *cdb,
463         int nonop_delay_msecs)
464 {
465         /*
466          * Set SCF_ALUA_NON_OPTIMIZED here, this value will be checked
467          * later to determine if processing of this cmd needs to be
468          * temporarily delayed for the Active/NonOptimized primary access state.
469          */
470         cmd->se_cmd_flags |= SCF_ALUA_NON_OPTIMIZED;
471         cmd->alua_nonop_delay = nonop_delay_msecs;
472 }
473
474 static inline int core_alua_state_lba_dependent(
475         struct se_cmd *cmd,
476         struct t10_alua_tg_pt_gp *tg_pt_gp)
477 {
478         struct se_device *dev = cmd->se_dev;
479         u64 segment_size, segment_mult, sectors, lba;
480
481         /* Only need to check for cdb actually containing LBAs */
482         if (!(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB))
483                 return 0;
484
485         spin_lock(&dev->t10_alua.lba_map_lock);
486         segment_size = dev->t10_alua.lba_map_segment_size;
487         segment_mult = dev->t10_alua.lba_map_segment_multiplier;
488         sectors = cmd->data_length / dev->dev_attrib.block_size;
489
490         lba = cmd->t_task_lba;
491         while (lba < cmd->t_task_lba + sectors) {
492                 struct t10_alua_lba_map *cur_map = NULL, *map;
493                 struct t10_alua_lba_map_member *map_mem;
494
495                 list_for_each_entry(map, &dev->t10_alua.lba_map_list,
496                                     lba_map_list) {
497                         u64 start_lba, last_lba;
498                         u64 first_lba = map->lba_map_first_lba;
499
500                         if (segment_mult) {
501                                 u64 tmp = lba;
502                                 start_lba = do_div(tmp, segment_size * segment_mult);
503
504                                 last_lba = first_lba + segment_size - 1;
505                                 if (start_lba >= first_lba &&
506                                     start_lba <= last_lba) {
507                                         lba += segment_size;
508                                         cur_map = map;
509                                         break;
510                                 }
511                         } else {
512                                 last_lba = map->lba_map_last_lba;
513                                 if (lba >= first_lba && lba <= last_lba) {
514                                         lba = last_lba + 1;
515                                         cur_map = map;
516                                         break;
517                                 }
518                         }
519                 }
520                 if (!cur_map) {
521                         spin_unlock(&dev->t10_alua.lba_map_lock);
522                         set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_UNAVAILABLE);
523                         return 1;
524                 }
525                 list_for_each_entry(map_mem, &cur_map->lba_map_mem_list,
526                                     lba_map_mem_list) {
527                         if (map_mem->lba_map_mem_alua_pg_id !=
528                             tg_pt_gp->tg_pt_gp_id)
529                                 continue;
530                         switch(map_mem->lba_map_mem_alua_state) {
531                         case ALUA_ACCESS_STATE_STANDBY:
532                                 spin_unlock(&dev->t10_alua.lba_map_lock);
533                                 set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_STANDBY);
534                                 return 1;
535                         case ALUA_ACCESS_STATE_UNAVAILABLE:
536                                 spin_unlock(&dev->t10_alua.lba_map_lock);
537                                 set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_UNAVAILABLE);
538                                 return 1;
539                         default:
540                                 break;
541                         }
542                 }
543         }
544         spin_unlock(&dev->t10_alua.lba_map_lock);
545         return 0;
546 }
547
548 static inline int core_alua_state_standby(
549         struct se_cmd *cmd,
550         unsigned char *cdb)
551 {
552         /*
553          * Allowed CDBs for ALUA_ACCESS_STATE_STANDBY as defined by
554          * spc4r17 section 5.9.2.4.4
555          */
556         switch (cdb[0]) {
557         case INQUIRY:
558         case LOG_SELECT:
559         case LOG_SENSE:
560         case MODE_SELECT:
561         case MODE_SENSE:
562         case REPORT_LUNS:
563         case RECEIVE_DIAGNOSTIC:
564         case SEND_DIAGNOSTIC:
565         case READ_CAPACITY:
566                 return 0;
567         case SERVICE_ACTION_IN_16:
568                 switch (cdb[1] & 0x1f) {
569                 case SAI_READ_CAPACITY_16:
570                         return 0;
571                 default:
572                         set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_STANDBY);
573                         return 1;
574                 }
575         case MAINTENANCE_IN:
576                 switch (cdb[1] & 0x1f) {
577                 case MI_REPORT_TARGET_PGS:
578                         return 0;
579                 default:
580                         set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_STANDBY);
581                         return 1;
582                 }
583         case MAINTENANCE_OUT:
584                 switch (cdb[1]) {
585                 case MO_SET_TARGET_PGS:
586                         return 0;
587                 default:
588                         set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_STANDBY);
589                         return 1;
590                 }
591         case REQUEST_SENSE:
592         case PERSISTENT_RESERVE_IN:
593         case PERSISTENT_RESERVE_OUT:
594         case READ_BUFFER:
595         case WRITE_BUFFER:
596                 return 0;
597         default:
598                 set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_STANDBY);
599                 return 1;
600         }
601
602         return 0;
603 }
604
605 static inline int core_alua_state_unavailable(
606         struct se_cmd *cmd,
607         unsigned char *cdb)
608 {
609         /*
610          * Allowed CDBs for ALUA_ACCESS_STATE_UNAVAILABLE as defined by
611          * spc4r17 section 5.9.2.4.5
612          */
613         switch (cdb[0]) {
614         case INQUIRY:
615         case REPORT_LUNS:
616                 return 0;
617         case MAINTENANCE_IN:
618                 switch (cdb[1] & 0x1f) {
619                 case MI_REPORT_TARGET_PGS:
620                         return 0;
621                 default:
622                         set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_UNAVAILABLE);
623                         return 1;
624                 }
625         case MAINTENANCE_OUT:
626                 switch (cdb[1]) {
627                 case MO_SET_TARGET_PGS:
628                         return 0;
629                 default:
630                         set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_UNAVAILABLE);
631                         return 1;
632                 }
633         case REQUEST_SENSE:
634         case READ_BUFFER:
635         case WRITE_BUFFER:
636                 return 0;
637         default:
638                 set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_UNAVAILABLE);
639                 return 1;
640         }
641
642         return 0;
643 }
644
645 static inline int core_alua_state_transition(
646         struct se_cmd *cmd,
647         unsigned char *cdb)
648 {
649         /*
650          * Allowed CDBs for ALUA_ACCESS_STATE_TRANSITION as defined by
651          * spc4r17 section 5.9.2.5
652          */
653         switch (cdb[0]) {
654         case INQUIRY:
655         case REPORT_LUNS:
656                 return 0;
657         case MAINTENANCE_IN:
658                 switch (cdb[1] & 0x1f) {
659                 case MI_REPORT_TARGET_PGS:
660                         return 0;
661                 default:
662                         set_ascq(cmd, ASCQ_04H_ALUA_STATE_TRANSITION);
663                         return 1;
664                 }
665         case REQUEST_SENSE:
666         case READ_BUFFER:
667         case WRITE_BUFFER:
668                 return 0;
669         default:
670                 set_ascq(cmd, ASCQ_04H_ALUA_STATE_TRANSITION);
671                 return 1;
672         }
673
674         return 0;
675 }
676
677 /*
678  * return 1: Is used to signal LUN not accessible, and check condition/not ready
679  * return 0: Used to signal success
680  * return -1: Used to signal failure, and invalid cdb field
681  */
682 sense_reason_t
683 target_alua_state_check(struct se_cmd *cmd)
684 {
685         struct se_device *dev = cmd->se_dev;
686         unsigned char *cdb = cmd->t_task_cdb;
687         struct se_lun *lun = cmd->se_lun;
688         struct t10_alua_tg_pt_gp *tg_pt_gp;
689         int out_alua_state, nonop_delay_msecs;
690
691         if (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)
692                 return 0;
693         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA)
694                 return 0;
695
696         /*
697          * First, check for a struct se_port specific secondary ALUA target port
698          * access state: OFFLINE
699          */
700         if (atomic_read(&lun->lun_tg_pt_secondary_offline)) {
701                 pr_debug("ALUA: Got secondary offline status for local"
702                                 " target port\n");
703                 set_ascq(cmd, ASCQ_04H_ALUA_OFFLINE);
704                 return TCM_CHECK_CONDITION_NOT_READY;
705         }
706
707         if (!lun->lun_tg_pt_gp)
708                 return 0;
709
710         spin_lock(&lun->lun_tg_pt_gp_lock);
711         tg_pt_gp = lun->lun_tg_pt_gp;
712         out_alua_state = tg_pt_gp->tg_pt_gp_alua_access_state;
713         nonop_delay_msecs = tg_pt_gp->tg_pt_gp_nonop_delay_msecs;
714
715         // XXX: keeps using tg_pt_gp witout reference after unlock
716         spin_unlock(&lun->lun_tg_pt_gp_lock);
717         /*
718          * Process ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED in a separate conditional
719          * statement so the compiler knows explicitly to check this case first.
720          * For the Optimized ALUA access state case, we want to process the
721          * incoming fabric cmd ASAP..
722          */
723         if (out_alua_state == ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED)
724                 return 0;
725
726         switch (out_alua_state) {
727         case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
728                 core_alua_state_nonoptimized(cmd, cdb, nonop_delay_msecs);
729                 break;
730         case ALUA_ACCESS_STATE_STANDBY:
731                 if (core_alua_state_standby(cmd, cdb))
732                         return TCM_CHECK_CONDITION_NOT_READY;
733                 break;
734         case ALUA_ACCESS_STATE_UNAVAILABLE:
735                 if (core_alua_state_unavailable(cmd, cdb))
736                         return TCM_CHECK_CONDITION_NOT_READY;
737                 break;
738         case ALUA_ACCESS_STATE_TRANSITION:
739                 if (core_alua_state_transition(cmd, cdb))
740                         return TCM_CHECK_CONDITION_NOT_READY;
741                 break;
742         case ALUA_ACCESS_STATE_LBA_DEPENDENT:
743                 if (core_alua_state_lba_dependent(cmd, tg_pt_gp))
744                         return TCM_CHECK_CONDITION_NOT_READY;
745                 break;
746         /*
747          * OFFLINE is a secondary ALUA target port group access state, that is
748          * handled above with struct se_lun->lun_tg_pt_secondary_offline=1
749          */
750         case ALUA_ACCESS_STATE_OFFLINE:
751         default:
752                 pr_err("Unknown ALUA access state: 0x%02x\n",
753                                 out_alua_state);
754                 return TCM_INVALID_CDB_FIELD;
755         }
756
757         return 0;
758 }
759
760 /*
761  * Check implicit and explicit ALUA state change request.
762  */
763 static sense_reason_t
764 core_alua_check_transition(int state, int valid, int *primary, int explicit)
765 {
766         /*
767          * OPTIMIZED, NON-OPTIMIZED, STANDBY and UNAVAILABLE are
768          * defined as primary target port asymmetric access states.
769          */
770         switch (state) {
771         case ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED:
772                 if (!(valid & ALUA_AO_SUP))
773                         goto not_supported;
774                 *primary = 1;
775                 break;
776         case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
777                 if (!(valid & ALUA_AN_SUP))
778                         goto not_supported;
779                 *primary = 1;
780                 break;
781         case ALUA_ACCESS_STATE_STANDBY:
782                 if (!(valid & ALUA_S_SUP))
783                         goto not_supported;
784                 *primary = 1;
785                 break;
786         case ALUA_ACCESS_STATE_UNAVAILABLE:
787                 if (!(valid & ALUA_U_SUP))
788                         goto not_supported;
789                 *primary = 1;
790                 break;
791         case ALUA_ACCESS_STATE_LBA_DEPENDENT:
792                 if (!(valid & ALUA_LBD_SUP))
793                         goto not_supported;
794                 *primary = 1;
795                 break;
796         case ALUA_ACCESS_STATE_OFFLINE:
797                 /*
798                  * OFFLINE state is defined as a secondary target port
799                  * asymmetric access state.
800                  */
801                 if (!(valid & ALUA_O_SUP))
802                         goto not_supported;
803                 *primary = 0;
804                 break;
805         case ALUA_ACCESS_STATE_TRANSITION:
806                 if (!(valid & ALUA_T_SUP) || explicit)
807                         /*
808                          * Transitioning is set internally and by tcmu daemon,
809                          * and cannot be selected through a STPG.
810                          */
811                         goto not_supported;
812                 *primary = 0;
813                 break;
814         default:
815                 pr_err("Unknown ALUA access state: 0x%02x\n", state);
816                 return TCM_INVALID_PARAMETER_LIST;
817         }
818
819         return 0;
820
821 not_supported:
822         pr_err("ALUA access state %s not supported",
823                core_alua_dump_state(state));
824         return TCM_INVALID_PARAMETER_LIST;
825 }
826
827 static char *core_alua_dump_state(int state)
828 {
829         switch (state) {
830         case ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED:
831                 return "Active/Optimized";
832         case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
833                 return "Active/NonOptimized";
834         case ALUA_ACCESS_STATE_LBA_DEPENDENT:
835                 return "LBA Dependent";
836         case ALUA_ACCESS_STATE_STANDBY:
837                 return "Standby";
838         case ALUA_ACCESS_STATE_UNAVAILABLE:
839                 return "Unavailable";
840         case ALUA_ACCESS_STATE_OFFLINE:
841                 return "Offline";
842         case ALUA_ACCESS_STATE_TRANSITION:
843                 return "Transitioning";
844         default:
845                 return "Unknown";
846         }
847
848         return NULL;
849 }
850
851 char *core_alua_dump_status(int status)
852 {
853         switch (status) {
854         case ALUA_STATUS_NONE:
855                 return "None";
856         case ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG:
857                 return "Altered by Explicit STPG";
858         case ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA:
859                 return "Altered by Implicit ALUA";
860         default:
861                 return "Unknown";
862         }
863
864         return NULL;
865 }
866
867 /*
868  * Used by fabric modules to determine when we need to delay processing
869  * for the Active/NonOptimized paths..
870  */
871 int core_alua_check_nonop_delay(
872         struct se_cmd *cmd)
873 {
874         if (!(cmd->se_cmd_flags & SCF_ALUA_NON_OPTIMIZED))
875                 return 0;
876         if (in_interrupt())
877                 return 0;
878         /*
879          * The ALUA Active/NonOptimized access state delay can be disabled
880          * in via configfs with a value of zero
881          */
882         if (!cmd->alua_nonop_delay)
883                 return 0;
884         /*
885          * struct se_cmd->alua_nonop_delay gets set by a target port group
886          * defined interval in core_alua_state_nonoptimized()
887          */
888         msleep_interruptible(cmd->alua_nonop_delay);
889         return 0;
890 }
891 EXPORT_SYMBOL(core_alua_check_nonop_delay);
892
893 static int core_alua_write_tpg_metadata(
894         const char *path,
895         unsigned char *md_buf,
896         u32 md_buf_len)
897 {
898         struct file *file = filp_open(path, O_RDWR | O_CREAT | O_TRUNC, 0600);
899         int ret;
900
901         if (IS_ERR(file)) {
902                 pr_err("filp_open(%s) for ALUA metadata failed\n", path);
903                 return -ENODEV;
904         }
905         ret = kernel_write(file, md_buf, md_buf_len, 0);
906         if (ret < 0)
907                 pr_err("Error writing ALUA metadata file: %s\n", path);
908         fput(file);
909         return (ret < 0) ? -EIO : 0;
910 }
911
912 /*
913  * Called with tg_pt_gp->tg_pt_gp_transition_mutex held
914  */
915 static int core_alua_update_tpg_primary_metadata(
916         struct t10_alua_tg_pt_gp *tg_pt_gp)
917 {
918         unsigned char *md_buf;
919         struct t10_wwn *wwn = &tg_pt_gp->tg_pt_gp_dev->t10_wwn;
920         char path[ALUA_METADATA_PATH_LEN];
921         int len, rc;
922
923         md_buf = kzalloc(ALUA_MD_BUF_LEN, GFP_KERNEL);
924         if (!md_buf) {
925                 pr_err("Unable to allocate buf for ALUA metadata\n");
926                 return -ENOMEM;
927         }
928
929         memset(path, 0, ALUA_METADATA_PATH_LEN);
930
931         len = snprintf(md_buf, ALUA_MD_BUF_LEN,
932                         "tg_pt_gp_id=%hu\n"
933                         "alua_access_state=0x%02x\n"
934                         "alua_access_status=0x%02x\n",
935                         tg_pt_gp->tg_pt_gp_id,
936                         tg_pt_gp->tg_pt_gp_alua_access_state,
937                         tg_pt_gp->tg_pt_gp_alua_access_status);
938
939         snprintf(path, ALUA_METADATA_PATH_LEN,
940                 "%s/alua/tpgs_%s/%s", db_root, &wwn->unit_serial[0],
941                 config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item));
942
943         rc = core_alua_write_tpg_metadata(path, md_buf, len);
944         kfree(md_buf);
945         return rc;
946 }
947
948 static void core_alua_queue_state_change_ua(struct t10_alua_tg_pt_gp *tg_pt_gp)
949 {
950         struct se_dev_entry *se_deve;
951         struct se_lun *lun;
952         struct se_lun_acl *lacl;
953
954         spin_lock(&tg_pt_gp->tg_pt_gp_lock);
955         list_for_each_entry(lun, &tg_pt_gp->tg_pt_gp_lun_list,
956                                 lun_tg_pt_gp_link) {
957                 /*
958                  * After an implicit target port asymmetric access state
959                  * change, a device server shall establish a unit attention
960                  * condition for the initiator port associated with every I_T
961                  * nexus with the additional sense code set to ASYMMETRIC
962                  * ACCESS STATE CHANGED.
963                  *
964                  * After an explicit target port asymmetric access state
965                  * change, a device server shall establish a unit attention
966                  * condition with the additional sense code set to ASYMMETRIC
967                  * ACCESS STATE CHANGED for the initiator port associated with
968                  * every I_T nexus other than the I_T nexus on which the SET
969                  * TARGET PORT GROUPS command
970                  */
971                 if (!percpu_ref_tryget_live(&lun->lun_ref))
972                         continue;
973                 spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
974
975                 spin_lock(&lun->lun_deve_lock);
976                 list_for_each_entry(se_deve, &lun->lun_deve_list, lun_link) {
977                         lacl = rcu_dereference_check(se_deve->se_lun_acl,
978                                         lockdep_is_held(&lun->lun_deve_lock));
979
980                         /*
981                          * spc4r37 p.242:
982                          * After an explicit target port asymmetric access
983                          * state change, a device server shall establish a
984                          * unit attention condition with the additional sense
985                          * code set to ASYMMETRIC ACCESS STATE CHANGED for
986                          * the initiator port associated with every I_T nexus
987                          * other than the I_T nexus on which the SET TARGET
988                          * PORT GROUPS command was received.
989                          */
990                         if ((tg_pt_gp->tg_pt_gp_alua_access_status ==
991                              ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG) &&
992                            (tg_pt_gp->tg_pt_gp_alua_lun != NULL) &&
993                             (tg_pt_gp->tg_pt_gp_alua_lun == lun))
994                                 continue;
995
996                         /*
997                          * se_deve->se_lun_acl pointer may be NULL for a
998                          * entry created without explicit Node+MappedLUN ACLs
999                          */
1000                         if (lacl && (tg_pt_gp->tg_pt_gp_alua_nacl != NULL) &&
1001                             (tg_pt_gp->tg_pt_gp_alua_nacl == lacl->se_lun_nacl))
1002                                 continue;
1003
1004                         core_scsi3_ua_allocate(se_deve, 0x2A,
1005                                 ASCQ_2AH_ASYMMETRIC_ACCESS_STATE_CHANGED);
1006                 }
1007                 spin_unlock(&lun->lun_deve_lock);
1008
1009                 spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1010                 percpu_ref_put(&lun->lun_ref);
1011         }
1012         spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1013 }
1014
1015 static int core_alua_do_transition_tg_pt(
1016         struct t10_alua_tg_pt_gp *tg_pt_gp,
1017         int new_state,
1018         int explicit)
1019 {
1020         int prev_state;
1021
1022         mutex_lock(&tg_pt_gp->tg_pt_gp_transition_mutex);
1023         /* Nothing to be done here */
1024         if (tg_pt_gp->tg_pt_gp_alua_access_state == new_state) {
1025                 mutex_unlock(&tg_pt_gp->tg_pt_gp_transition_mutex);
1026                 return 0;
1027         }
1028
1029         if (explicit && new_state == ALUA_ACCESS_STATE_TRANSITION) {
1030                 mutex_unlock(&tg_pt_gp->tg_pt_gp_transition_mutex);
1031                 return -EAGAIN;
1032         }
1033
1034         /*
1035          * Save the old primary ALUA access state, and set the current state
1036          * to ALUA_ACCESS_STATE_TRANSITION.
1037          */
1038         prev_state = tg_pt_gp->tg_pt_gp_alua_access_state;
1039         tg_pt_gp->tg_pt_gp_alua_access_state = ALUA_ACCESS_STATE_TRANSITION;
1040         tg_pt_gp->tg_pt_gp_alua_access_status = (explicit) ?
1041                                 ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG :
1042                                 ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA;
1043
1044         core_alua_queue_state_change_ua(tg_pt_gp);
1045
1046         if (new_state == ALUA_ACCESS_STATE_TRANSITION) {
1047                 mutex_unlock(&tg_pt_gp->tg_pt_gp_transition_mutex);
1048                 return 0;
1049         }
1050
1051         /*
1052          * Check for the optional ALUA primary state transition delay
1053          */
1054         if (tg_pt_gp->tg_pt_gp_trans_delay_msecs != 0)
1055                 msleep_interruptible(tg_pt_gp->tg_pt_gp_trans_delay_msecs);
1056
1057         /*
1058          * Set the current primary ALUA access state to the requested new state
1059          */
1060         tg_pt_gp->tg_pt_gp_alua_access_state = new_state;
1061
1062         /*
1063          * Update the ALUA metadata buf that has been allocated in
1064          * core_alua_do_port_transition(), this metadata will be written
1065          * to struct file.
1066          *
1067          * Note that there is the case where we do not want to update the
1068          * metadata when the saved metadata is being parsed in userspace
1069          * when setting the existing port access state and access status.
1070          *
1071          * Also note that the failure to write out the ALUA metadata to
1072          * struct file does NOT affect the actual ALUA transition.
1073          */
1074         if (tg_pt_gp->tg_pt_gp_write_metadata) {
1075                 core_alua_update_tpg_primary_metadata(tg_pt_gp);
1076         }
1077
1078         pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
1079                 " from primary access state %s to %s\n", (explicit) ? "explicit" :
1080                 "implicit", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
1081                 tg_pt_gp->tg_pt_gp_id,
1082                 core_alua_dump_state(prev_state),
1083                 core_alua_dump_state(new_state));
1084
1085         core_alua_queue_state_change_ua(tg_pt_gp);
1086
1087         mutex_unlock(&tg_pt_gp->tg_pt_gp_transition_mutex);
1088         return 0;
1089 }
1090
1091 int core_alua_do_port_transition(
1092         struct t10_alua_tg_pt_gp *l_tg_pt_gp,
1093         struct se_device *l_dev,
1094         struct se_lun *l_lun,
1095         struct se_node_acl *l_nacl,
1096         int new_state,
1097         int explicit)
1098 {
1099         struct se_device *dev;
1100         struct t10_alua_lu_gp *lu_gp;
1101         struct t10_alua_lu_gp_member *lu_gp_mem, *local_lu_gp_mem;
1102         struct t10_alua_tg_pt_gp *tg_pt_gp;
1103         int primary, valid_states, rc = 0;
1104
1105         if (l_dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA)
1106                 return -ENODEV;
1107
1108         valid_states = l_tg_pt_gp->tg_pt_gp_alua_supported_states;
1109         if (core_alua_check_transition(new_state, valid_states, &primary,
1110                                        explicit) != 0)
1111                 return -EINVAL;
1112
1113         local_lu_gp_mem = l_dev->dev_alua_lu_gp_mem;
1114         spin_lock(&local_lu_gp_mem->lu_gp_mem_lock);
1115         lu_gp = local_lu_gp_mem->lu_gp;
1116         atomic_inc(&lu_gp->lu_gp_ref_cnt);
1117         spin_unlock(&local_lu_gp_mem->lu_gp_mem_lock);
1118         /*
1119          * For storage objects that are members of the 'default_lu_gp',
1120          * we only do transition on the passed *l_tp_pt_gp, and not
1121          * on all of the matching target port groups IDs in default_lu_gp.
1122          */
1123         if (!lu_gp->lu_gp_id) {
1124                 /*
1125                  * core_alua_do_transition_tg_pt() will always return
1126                  * success.
1127                  */
1128                 l_tg_pt_gp->tg_pt_gp_alua_lun = l_lun;
1129                 l_tg_pt_gp->tg_pt_gp_alua_nacl = l_nacl;
1130                 rc = core_alua_do_transition_tg_pt(l_tg_pt_gp,
1131                                                    new_state, explicit);
1132                 atomic_dec_mb(&lu_gp->lu_gp_ref_cnt);
1133                 return rc;
1134         }
1135         /*
1136          * For all other LU groups aside from 'default_lu_gp', walk all of
1137          * the associated storage objects looking for a matching target port
1138          * group ID from the local target port group.
1139          */
1140         spin_lock(&lu_gp->lu_gp_lock);
1141         list_for_each_entry(lu_gp_mem, &lu_gp->lu_gp_mem_list,
1142                                 lu_gp_mem_list) {
1143
1144                 dev = lu_gp_mem->lu_gp_mem_dev;
1145                 atomic_inc_mb(&lu_gp_mem->lu_gp_mem_ref_cnt);
1146                 spin_unlock(&lu_gp->lu_gp_lock);
1147
1148                 spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1149                 list_for_each_entry(tg_pt_gp,
1150                                 &dev->t10_alua.tg_pt_gps_list,
1151                                 tg_pt_gp_list) {
1152
1153                         if (!tg_pt_gp->tg_pt_gp_valid_id)
1154                                 continue;
1155                         /*
1156                          * If the target behavior port asymmetric access state
1157                          * is changed for any target port group accessible via
1158                          * a logical unit within a LU group, the target port
1159                          * behavior group asymmetric access states for the same
1160                          * target port group accessible via other logical units
1161                          * in that LU group will also change.
1162                          */
1163                         if (l_tg_pt_gp->tg_pt_gp_id != tg_pt_gp->tg_pt_gp_id)
1164                                 continue;
1165
1166                         if (l_tg_pt_gp == tg_pt_gp) {
1167                                 tg_pt_gp->tg_pt_gp_alua_lun = l_lun;
1168                                 tg_pt_gp->tg_pt_gp_alua_nacl = l_nacl;
1169                         } else {
1170                                 tg_pt_gp->tg_pt_gp_alua_lun = NULL;
1171                                 tg_pt_gp->tg_pt_gp_alua_nacl = NULL;
1172                         }
1173                         atomic_inc_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);
1174                         spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1175                         /*
1176                          * core_alua_do_transition_tg_pt() will always return
1177                          * success.
1178                          */
1179                         rc = core_alua_do_transition_tg_pt(tg_pt_gp,
1180                                         new_state, explicit);
1181
1182                         spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1183                         atomic_dec_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);
1184                         if (rc)
1185                                 break;
1186                 }
1187                 spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1188
1189                 spin_lock(&lu_gp->lu_gp_lock);
1190                 atomic_dec_mb(&lu_gp_mem->lu_gp_mem_ref_cnt);
1191         }
1192         spin_unlock(&lu_gp->lu_gp_lock);
1193
1194         if (!rc) {
1195                 pr_debug("Successfully processed LU Group: %s all ALUA TG PT"
1196                          " Group IDs: %hu %s transition to primary state: %s\n",
1197                          config_item_name(&lu_gp->lu_gp_group.cg_item),
1198                          l_tg_pt_gp->tg_pt_gp_id,
1199                          (explicit) ? "explicit" : "implicit",
1200                          core_alua_dump_state(new_state));
1201         }
1202
1203         atomic_dec_mb(&lu_gp->lu_gp_ref_cnt);
1204         return rc;
1205 }
1206
1207 static int core_alua_update_tpg_secondary_metadata(struct se_lun *lun)
1208 {
1209         struct se_portal_group *se_tpg = lun->lun_tpg;
1210         unsigned char *md_buf;
1211         char path[ALUA_METADATA_PATH_LEN], wwn[ALUA_SECONDARY_METADATA_WWN_LEN];
1212         int len, rc;
1213
1214         mutex_lock(&lun->lun_tg_pt_md_mutex);
1215
1216         md_buf = kzalloc(ALUA_MD_BUF_LEN, GFP_KERNEL);
1217         if (!md_buf) {
1218                 pr_err("Unable to allocate buf for ALUA metadata\n");
1219                 rc = -ENOMEM;
1220                 goto out_unlock;
1221         }
1222
1223         memset(path, 0, ALUA_METADATA_PATH_LEN);
1224         memset(wwn, 0, ALUA_SECONDARY_METADATA_WWN_LEN);
1225
1226         len = snprintf(wwn, ALUA_SECONDARY_METADATA_WWN_LEN, "%s",
1227                         se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg));
1228
1229         if (se_tpg->se_tpg_tfo->tpg_get_tag != NULL)
1230                 snprintf(wwn+len, ALUA_SECONDARY_METADATA_WWN_LEN-len, "+%hu",
1231                                 se_tpg->se_tpg_tfo->tpg_get_tag(se_tpg));
1232
1233         len = snprintf(md_buf, ALUA_MD_BUF_LEN, "alua_tg_pt_offline=%d\n"
1234                         "alua_tg_pt_status=0x%02x\n",
1235                         atomic_read(&lun->lun_tg_pt_secondary_offline),
1236                         lun->lun_tg_pt_secondary_stat);
1237
1238         snprintf(path, ALUA_METADATA_PATH_LEN, "%s/alua/%s/%s/lun_%llu",
1239                         db_root, se_tpg->se_tpg_tfo->get_fabric_name(), wwn,
1240                         lun->unpacked_lun);
1241
1242         rc = core_alua_write_tpg_metadata(path, md_buf, len);
1243         kfree(md_buf);
1244
1245 out_unlock:
1246         mutex_unlock(&lun->lun_tg_pt_md_mutex);
1247         return rc;
1248 }
1249
1250 static int core_alua_set_tg_pt_secondary_state(
1251         struct se_lun *lun,
1252         int explicit,
1253         int offline)
1254 {
1255         struct t10_alua_tg_pt_gp *tg_pt_gp;
1256         int trans_delay_msecs;
1257
1258         spin_lock(&lun->lun_tg_pt_gp_lock);
1259         tg_pt_gp = lun->lun_tg_pt_gp;
1260         if (!tg_pt_gp) {
1261                 spin_unlock(&lun->lun_tg_pt_gp_lock);
1262                 pr_err("Unable to complete secondary state"
1263                                 " transition\n");
1264                 return -EINVAL;
1265         }
1266         trans_delay_msecs = tg_pt_gp->tg_pt_gp_trans_delay_msecs;
1267         /*
1268          * Set the secondary ALUA target port access state to OFFLINE
1269          * or release the previously secondary state for struct se_lun
1270          */
1271         if (offline)
1272                 atomic_set(&lun->lun_tg_pt_secondary_offline, 1);
1273         else
1274                 atomic_set(&lun->lun_tg_pt_secondary_offline, 0);
1275
1276         lun->lun_tg_pt_secondary_stat = (explicit) ?
1277                         ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG :
1278                         ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA;
1279
1280         pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
1281                 " to secondary access state: %s\n", (explicit) ? "explicit" :
1282                 "implicit", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
1283                 tg_pt_gp->tg_pt_gp_id, (offline) ? "OFFLINE" : "ONLINE");
1284
1285         spin_unlock(&lun->lun_tg_pt_gp_lock);
1286         /*
1287          * Do the optional transition delay after we set the secondary
1288          * ALUA access state.
1289          */
1290         if (trans_delay_msecs != 0)
1291                 msleep_interruptible(trans_delay_msecs);
1292         /*
1293          * See if we need to update the ALUA fabric port metadata for
1294          * secondary state and status
1295          */
1296         if (lun->lun_tg_pt_secondary_write_md)
1297                 core_alua_update_tpg_secondary_metadata(lun);
1298
1299         return 0;
1300 }
1301
1302 struct t10_alua_lba_map *
1303 core_alua_allocate_lba_map(struct list_head *list,
1304                            u64 first_lba, u64 last_lba)
1305 {
1306         struct t10_alua_lba_map *lba_map;
1307
1308         lba_map = kmem_cache_zalloc(t10_alua_lba_map_cache, GFP_KERNEL);
1309         if (!lba_map) {
1310                 pr_err("Unable to allocate struct t10_alua_lba_map\n");
1311                 return ERR_PTR(-ENOMEM);
1312         }
1313         INIT_LIST_HEAD(&lba_map->lba_map_mem_list);
1314         lba_map->lba_map_first_lba = first_lba;
1315         lba_map->lba_map_last_lba = last_lba;
1316
1317         list_add_tail(&lba_map->lba_map_list, list);
1318         return lba_map;
1319 }
1320
1321 int
1322 core_alua_allocate_lba_map_mem(struct t10_alua_lba_map *lba_map,
1323                                int pg_id, int state)
1324 {
1325         struct t10_alua_lba_map_member *lba_map_mem;
1326
1327         list_for_each_entry(lba_map_mem, &lba_map->lba_map_mem_list,
1328                             lba_map_mem_list) {
1329                 if (lba_map_mem->lba_map_mem_alua_pg_id == pg_id) {
1330                         pr_err("Duplicate pg_id %d in lba_map\n", pg_id);
1331                         return -EINVAL;
1332                 }
1333         }
1334
1335         lba_map_mem = kmem_cache_zalloc(t10_alua_lba_map_mem_cache, GFP_KERNEL);
1336         if (!lba_map_mem) {
1337                 pr_err("Unable to allocate struct t10_alua_lba_map_mem\n");
1338                 return -ENOMEM;
1339         }
1340         lba_map_mem->lba_map_mem_alua_state = state;
1341         lba_map_mem->lba_map_mem_alua_pg_id = pg_id;
1342
1343         list_add_tail(&lba_map_mem->lba_map_mem_list,
1344                       &lba_map->lba_map_mem_list);
1345         return 0;
1346 }
1347
1348 void
1349 core_alua_free_lba_map(struct list_head *lba_list)
1350 {
1351         struct t10_alua_lba_map *lba_map, *lba_map_tmp;
1352         struct t10_alua_lba_map_member *lba_map_mem, *lba_map_mem_tmp;
1353
1354         list_for_each_entry_safe(lba_map, lba_map_tmp, lba_list,
1355                                  lba_map_list) {
1356                 list_for_each_entry_safe(lba_map_mem, lba_map_mem_tmp,
1357                                          &lba_map->lba_map_mem_list,
1358                                          lba_map_mem_list) {
1359                         list_del(&lba_map_mem->lba_map_mem_list);
1360                         kmem_cache_free(t10_alua_lba_map_mem_cache,
1361                                         lba_map_mem);
1362                 }
1363                 list_del(&lba_map->lba_map_list);
1364                 kmem_cache_free(t10_alua_lba_map_cache, lba_map);
1365         }
1366 }
1367
1368 void
1369 core_alua_set_lba_map(struct se_device *dev, struct list_head *lba_map_list,
1370                       int segment_size, int segment_mult)
1371 {
1372         struct list_head old_lba_map_list;
1373         struct t10_alua_tg_pt_gp *tg_pt_gp;
1374         int activate = 0, supported;
1375
1376         INIT_LIST_HEAD(&old_lba_map_list);
1377         spin_lock(&dev->t10_alua.lba_map_lock);
1378         dev->t10_alua.lba_map_segment_size = segment_size;
1379         dev->t10_alua.lba_map_segment_multiplier = segment_mult;
1380         list_splice_init(&dev->t10_alua.lba_map_list, &old_lba_map_list);
1381         if (lba_map_list) {
1382                 list_splice_init(lba_map_list, &dev->t10_alua.lba_map_list);
1383                 activate = 1;
1384         }
1385         spin_unlock(&dev->t10_alua.lba_map_lock);
1386         spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1387         list_for_each_entry(tg_pt_gp, &dev->t10_alua.tg_pt_gps_list,
1388                             tg_pt_gp_list) {
1389
1390                 if (!tg_pt_gp->tg_pt_gp_valid_id)
1391                         continue;
1392                 supported = tg_pt_gp->tg_pt_gp_alua_supported_states;
1393                 if (activate)
1394                         supported |= ALUA_LBD_SUP;
1395                 else
1396                         supported &= ~ALUA_LBD_SUP;
1397                 tg_pt_gp->tg_pt_gp_alua_supported_states = supported;
1398         }
1399         spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1400         core_alua_free_lba_map(&old_lba_map_list);
1401 }
1402
1403 struct t10_alua_lu_gp *
1404 core_alua_allocate_lu_gp(const char *name, int def_group)
1405 {
1406         struct t10_alua_lu_gp *lu_gp;
1407
1408         lu_gp = kmem_cache_zalloc(t10_alua_lu_gp_cache, GFP_KERNEL);
1409         if (!lu_gp) {
1410                 pr_err("Unable to allocate struct t10_alua_lu_gp\n");
1411                 return ERR_PTR(-ENOMEM);
1412         }
1413         INIT_LIST_HEAD(&lu_gp->lu_gp_node);
1414         INIT_LIST_HEAD(&lu_gp->lu_gp_mem_list);
1415         spin_lock_init(&lu_gp->lu_gp_lock);
1416         atomic_set(&lu_gp->lu_gp_ref_cnt, 0);
1417
1418         if (def_group) {
1419                 lu_gp->lu_gp_id = alua_lu_gps_counter++;
1420                 lu_gp->lu_gp_valid_id = 1;
1421                 alua_lu_gps_count++;
1422         }
1423
1424         return lu_gp;
1425 }
1426
1427 int core_alua_set_lu_gp_id(struct t10_alua_lu_gp *lu_gp, u16 lu_gp_id)
1428 {
1429         struct t10_alua_lu_gp *lu_gp_tmp;
1430         u16 lu_gp_id_tmp;
1431         /*
1432          * The lu_gp->lu_gp_id may only be set once..
1433          */
1434         if (lu_gp->lu_gp_valid_id) {
1435                 pr_warn("ALUA LU Group already has a valid ID,"
1436                         " ignoring request\n");
1437                 return -EINVAL;
1438         }
1439
1440         spin_lock(&lu_gps_lock);
1441         if (alua_lu_gps_count == 0x0000ffff) {
1442                 pr_err("Maximum ALUA alua_lu_gps_count:"
1443                                 " 0x0000ffff reached\n");
1444                 spin_unlock(&lu_gps_lock);
1445                 kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1446                 return -ENOSPC;
1447         }
1448 again:
1449         lu_gp_id_tmp = (lu_gp_id != 0) ? lu_gp_id :
1450                                 alua_lu_gps_counter++;
1451
1452         list_for_each_entry(lu_gp_tmp, &lu_gps_list, lu_gp_node) {
1453                 if (lu_gp_tmp->lu_gp_id == lu_gp_id_tmp) {
1454                         if (!lu_gp_id)
1455                                 goto again;
1456
1457                         pr_warn("ALUA Logical Unit Group ID: %hu"
1458                                 " already exists, ignoring request\n",
1459                                 lu_gp_id);
1460                         spin_unlock(&lu_gps_lock);
1461                         return -EINVAL;
1462                 }
1463         }
1464
1465         lu_gp->lu_gp_id = lu_gp_id_tmp;
1466         lu_gp->lu_gp_valid_id = 1;
1467         list_add_tail(&lu_gp->lu_gp_node, &lu_gps_list);
1468         alua_lu_gps_count++;
1469         spin_unlock(&lu_gps_lock);
1470
1471         return 0;
1472 }
1473
1474 static struct t10_alua_lu_gp_member *
1475 core_alua_allocate_lu_gp_mem(struct se_device *dev)
1476 {
1477         struct t10_alua_lu_gp_member *lu_gp_mem;
1478
1479         lu_gp_mem = kmem_cache_zalloc(t10_alua_lu_gp_mem_cache, GFP_KERNEL);
1480         if (!lu_gp_mem) {
1481                 pr_err("Unable to allocate struct t10_alua_lu_gp_member\n");
1482                 return ERR_PTR(-ENOMEM);
1483         }
1484         INIT_LIST_HEAD(&lu_gp_mem->lu_gp_mem_list);
1485         spin_lock_init(&lu_gp_mem->lu_gp_mem_lock);
1486         atomic_set(&lu_gp_mem->lu_gp_mem_ref_cnt, 0);
1487
1488         lu_gp_mem->lu_gp_mem_dev = dev;
1489         dev->dev_alua_lu_gp_mem = lu_gp_mem;
1490
1491         return lu_gp_mem;
1492 }
1493
1494 void core_alua_free_lu_gp(struct t10_alua_lu_gp *lu_gp)
1495 {
1496         struct t10_alua_lu_gp_member *lu_gp_mem, *lu_gp_mem_tmp;
1497         /*
1498          * Once we have reached this point, config_item_put() has
1499          * already been called from target_core_alua_drop_lu_gp().
1500          *
1501          * Here, we remove the *lu_gp from the global list so that
1502          * no associations can be made while we are releasing
1503          * struct t10_alua_lu_gp.
1504          */
1505         spin_lock(&lu_gps_lock);
1506         list_del(&lu_gp->lu_gp_node);
1507         alua_lu_gps_count--;
1508         spin_unlock(&lu_gps_lock);
1509         /*
1510          * Allow struct t10_alua_lu_gp * referenced by core_alua_get_lu_gp_by_name()
1511          * in target_core_configfs.c:target_core_store_alua_lu_gp() to be
1512          * released with core_alua_put_lu_gp_from_name()
1513          */
1514         while (atomic_read(&lu_gp->lu_gp_ref_cnt))
1515                 cpu_relax();
1516         /*
1517          * Release reference to struct t10_alua_lu_gp * from all associated
1518          * struct se_device.
1519          */
1520         spin_lock(&lu_gp->lu_gp_lock);
1521         list_for_each_entry_safe(lu_gp_mem, lu_gp_mem_tmp,
1522                                 &lu_gp->lu_gp_mem_list, lu_gp_mem_list) {
1523                 if (lu_gp_mem->lu_gp_assoc) {
1524                         list_del(&lu_gp_mem->lu_gp_mem_list);
1525                         lu_gp->lu_gp_members--;
1526                         lu_gp_mem->lu_gp_assoc = 0;
1527                 }
1528                 spin_unlock(&lu_gp->lu_gp_lock);
1529                 /*
1530                  *
1531                  * lu_gp_mem is associated with a single
1532                  * struct se_device->dev_alua_lu_gp_mem, and is released when
1533                  * struct se_device is released via core_alua_free_lu_gp_mem().
1534                  *
1535                  * If the passed lu_gp does NOT match the default_lu_gp, assume
1536                  * we want to re-associate a given lu_gp_mem with default_lu_gp.
1537                  */
1538                 spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1539                 if (lu_gp != default_lu_gp)
1540                         __core_alua_attach_lu_gp_mem(lu_gp_mem,
1541                                         default_lu_gp);
1542                 else
1543                         lu_gp_mem->lu_gp = NULL;
1544                 spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1545
1546                 spin_lock(&lu_gp->lu_gp_lock);
1547         }
1548         spin_unlock(&lu_gp->lu_gp_lock);
1549
1550         kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1551 }
1552
1553 void core_alua_free_lu_gp_mem(struct se_device *dev)
1554 {
1555         struct t10_alua_lu_gp *lu_gp;
1556         struct t10_alua_lu_gp_member *lu_gp_mem;
1557
1558         lu_gp_mem = dev->dev_alua_lu_gp_mem;
1559         if (!lu_gp_mem)
1560                 return;
1561
1562         while (atomic_read(&lu_gp_mem->lu_gp_mem_ref_cnt))
1563                 cpu_relax();
1564
1565         spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1566         lu_gp = lu_gp_mem->lu_gp;
1567         if (lu_gp) {
1568                 spin_lock(&lu_gp->lu_gp_lock);
1569                 if (lu_gp_mem->lu_gp_assoc) {
1570                         list_del(&lu_gp_mem->lu_gp_mem_list);
1571                         lu_gp->lu_gp_members--;
1572                         lu_gp_mem->lu_gp_assoc = 0;
1573                 }
1574                 spin_unlock(&lu_gp->lu_gp_lock);
1575                 lu_gp_mem->lu_gp = NULL;
1576         }
1577         spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1578
1579         kmem_cache_free(t10_alua_lu_gp_mem_cache, lu_gp_mem);
1580 }
1581
1582 struct t10_alua_lu_gp *core_alua_get_lu_gp_by_name(const char *name)
1583 {
1584         struct t10_alua_lu_gp *lu_gp;
1585         struct config_item *ci;
1586
1587         spin_lock(&lu_gps_lock);
1588         list_for_each_entry(lu_gp, &lu_gps_list, lu_gp_node) {
1589                 if (!lu_gp->lu_gp_valid_id)
1590                         continue;
1591                 ci = &lu_gp->lu_gp_group.cg_item;
1592                 if (!strcmp(config_item_name(ci), name)) {
1593                         atomic_inc(&lu_gp->lu_gp_ref_cnt);
1594                         spin_unlock(&lu_gps_lock);
1595                         return lu_gp;
1596                 }
1597         }
1598         spin_unlock(&lu_gps_lock);
1599
1600         return NULL;
1601 }
1602
1603 void core_alua_put_lu_gp_from_name(struct t10_alua_lu_gp *lu_gp)
1604 {
1605         spin_lock(&lu_gps_lock);
1606         atomic_dec(&lu_gp->lu_gp_ref_cnt);
1607         spin_unlock(&lu_gps_lock);
1608 }
1609
1610 /*
1611  * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1612  */
1613 void __core_alua_attach_lu_gp_mem(
1614         struct t10_alua_lu_gp_member *lu_gp_mem,
1615         struct t10_alua_lu_gp *lu_gp)
1616 {
1617         spin_lock(&lu_gp->lu_gp_lock);
1618         lu_gp_mem->lu_gp = lu_gp;
1619         lu_gp_mem->lu_gp_assoc = 1;
1620         list_add_tail(&lu_gp_mem->lu_gp_mem_list, &lu_gp->lu_gp_mem_list);
1621         lu_gp->lu_gp_members++;
1622         spin_unlock(&lu_gp->lu_gp_lock);
1623 }
1624
1625 /*
1626  * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1627  */
1628 void __core_alua_drop_lu_gp_mem(
1629         struct t10_alua_lu_gp_member *lu_gp_mem,
1630         struct t10_alua_lu_gp *lu_gp)
1631 {
1632         spin_lock(&lu_gp->lu_gp_lock);
1633         list_del(&lu_gp_mem->lu_gp_mem_list);
1634         lu_gp_mem->lu_gp = NULL;
1635         lu_gp_mem->lu_gp_assoc = 0;
1636         lu_gp->lu_gp_members--;
1637         spin_unlock(&lu_gp->lu_gp_lock);
1638 }
1639
1640 struct t10_alua_tg_pt_gp *core_alua_allocate_tg_pt_gp(struct se_device *dev,
1641                 const char *name, int def_group)
1642 {
1643         struct t10_alua_tg_pt_gp *tg_pt_gp;
1644
1645         tg_pt_gp = kmem_cache_zalloc(t10_alua_tg_pt_gp_cache, GFP_KERNEL);
1646         if (!tg_pt_gp) {
1647                 pr_err("Unable to allocate struct t10_alua_tg_pt_gp\n");
1648                 return NULL;
1649         }
1650         INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_list);
1651         INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_lun_list);
1652         mutex_init(&tg_pt_gp->tg_pt_gp_transition_mutex);
1653         spin_lock_init(&tg_pt_gp->tg_pt_gp_lock);
1654         atomic_set(&tg_pt_gp->tg_pt_gp_ref_cnt, 0);
1655         tg_pt_gp->tg_pt_gp_dev = dev;
1656         tg_pt_gp->tg_pt_gp_alua_access_state =
1657                         ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED;
1658         /*
1659          * Enable both explicit and implicit ALUA support by default
1660          */
1661         tg_pt_gp->tg_pt_gp_alua_access_type =
1662                         TPGS_EXPLICIT_ALUA | TPGS_IMPLICIT_ALUA;
1663         /*
1664          * Set the default Active/NonOptimized Delay in milliseconds
1665          */
1666         tg_pt_gp->tg_pt_gp_nonop_delay_msecs = ALUA_DEFAULT_NONOP_DELAY_MSECS;
1667         tg_pt_gp->tg_pt_gp_trans_delay_msecs = ALUA_DEFAULT_TRANS_DELAY_MSECS;
1668         tg_pt_gp->tg_pt_gp_implicit_trans_secs = ALUA_DEFAULT_IMPLICIT_TRANS_SECS;
1669
1670         /*
1671          * Enable all supported states
1672          */
1673         tg_pt_gp->tg_pt_gp_alua_supported_states =
1674             ALUA_T_SUP | ALUA_O_SUP |
1675             ALUA_U_SUP | ALUA_S_SUP | ALUA_AN_SUP | ALUA_AO_SUP;
1676
1677         if (def_group) {
1678                 spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1679                 tg_pt_gp->tg_pt_gp_id =
1680                                 dev->t10_alua.alua_tg_pt_gps_counter++;
1681                 tg_pt_gp->tg_pt_gp_valid_id = 1;
1682                 dev->t10_alua.alua_tg_pt_gps_count++;
1683                 list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1684                               &dev->t10_alua.tg_pt_gps_list);
1685                 spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1686         }
1687
1688         return tg_pt_gp;
1689 }
1690
1691 int core_alua_set_tg_pt_gp_id(
1692         struct t10_alua_tg_pt_gp *tg_pt_gp,
1693         u16 tg_pt_gp_id)
1694 {
1695         struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
1696         struct t10_alua_tg_pt_gp *tg_pt_gp_tmp;
1697         u16 tg_pt_gp_id_tmp;
1698
1699         /*
1700          * The tg_pt_gp->tg_pt_gp_id may only be set once..
1701          */
1702         if (tg_pt_gp->tg_pt_gp_valid_id) {
1703                 pr_warn("ALUA TG PT Group already has a valid ID,"
1704                         " ignoring request\n");
1705                 return -EINVAL;
1706         }
1707
1708         spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1709         if (dev->t10_alua.alua_tg_pt_gps_count == 0x0000ffff) {
1710                 pr_err("Maximum ALUA alua_tg_pt_gps_count:"
1711                         " 0x0000ffff reached\n");
1712                 spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1713                 kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
1714                 return -ENOSPC;
1715         }
1716 again:
1717         tg_pt_gp_id_tmp = (tg_pt_gp_id != 0) ? tg_pt_gp_id :
1718                         dev->t10_alua.alua_tg_pt_gps_counter++;
1719
1720         list_for_each_entry(tg_pt_gp_tmp, &dev->t10_alua.tg_pt_gps_list,
1721                         tg_pt_gp_list) {
1722                 if (tg_pt_gp_tmp->tg_pt_gp_id == tg_pt_gp_id_tmp) {
1723                         if (!tg_pt_gp_id)
1724                                 goto again;
1725
1726                         pr_err("ALUA Target Port Group ID: %hu already"
1727                                 " exists, ignoring request\n", tg_pt_gp_id);
1728                         spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1729                         return -EINVAL;
1730                 }
1731         }
1732
1733         tg_pt_gp->tg_pt_gp_id = tg_pt_gp_id_tmp;
1734         tg_pt_gp->tg_pt_gp_valid_id = 1;
1735         list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1736                         &dev->t10_alua.tg_pt_gps_list);
1737         dev->t10_alua.alua_tg_pt_gps_count++;
1738         spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1739
1740         return 0;
1741 }
1742
1743 void core_alua_free_tg_pt_gp(
1744         struct t10_alua_tg_pt_gp *tg_pt_gp)
1745 {
1746         struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
1747         struct se_lun *lun, *next;
1748
1749         /*
1750          * Once we have reached this point, config_item_put() has already
1751          * been called from target_core_alua_drop_tg_pt_gp().
1752          *
1753          * Here we remove *tg_pt_gp from the global list so that
1754          * no associations *OR* explicit ALUA via SET_TARGET_PORT_GROUPS
1755          * can be made while we are releasing struct t10_alua_tg_pt_gp.
1756          */
1757         spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1758         list_del(&tg_pt_gp->tg_pt_gp_list);
1759         dev->t10_alua.alua_tg_pt_gps_counter--;
1760         spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1761
1762         /*
1763          * Allow a struct t10_alua_tg_pt_gp_member * referenced by
1764          * core_alua_get_tg_pt_gp_by_name() in
1765          * target_core_configfs.c:target_core_store_alua_tg_pt_gp()
1766          * to be released with core_alua_put_tg_pt_gp_from_name().
1767          */
1768         while (atomic_read(&tg_pt_gp->tg_pt_gp_ref_cnt))
1769                 cpu_relax();
1770
1771         /*
1772          * Release reference to struct t10_alua_tg_pt_gp from all associated
1773          * struct se_port.
1774          */
1775         spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1776         list_for_each_entry_safe(lun, next,
1777                         &tg_pt_gp->tg_pt_gp_lun_list, lun_tg_pt_gp_link) {
1778                 list_del_init(&lun->lun_tg_pt_gp_link);
1779                 tg_pt_gp->tg_pt_gp_members--;
1780
1781                 spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1782                 /*
1783                  * If the passed tg_pt_gp does NOT match the default_tg_pt_gp,
1784                  * assume we want to re-associate a given tg_pt_gp_mem with
1785                  * default_tg_pt_gp.
1786                  */
1787                 spin_lock(&lun->lun_tg_pt_gp_lock);
1788                 if (tg_pt_gp != dev->t10_alua.default_tg_pt_gp) {
1789                         __target_attach_tg_pt_gp(lun,
1790                                         dev->t10_alua.default_tg_pt_gp);
1791                 } else
1792                         lun->lun_tg_pt_gp = NULL;
1793                 spin_unlock(&lun->lun_tg_pt_gp_lock);
1794
1795                 spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1796         }
1797         spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1798
1799         kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
1800 }
1801
1802 static struct t10_alua_tg_pt_gp *core_alua_get_tg_pt_gp_by_name(
1803                 struct se_device *dev, const char *name)
1804 {
1805         struct t10_alua_tg_pt_gp *tg_pt_gp;
1806         struct config_item *ci;
1807
1808         spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1809         list_for_each_entry(tg_pt_gp, &dev->t10_alua.tg_pt_gps_list,
1810                         tg_pt_gp_list) {
1811                 if (!tg_pt_gp->tg_pt_gp_valid_id)
1812                         continue;
1813                 ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1814                 if (!strcmp(config_item_name(ci), name)) {
1815                         atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
1816                         spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1817                         return tg_pt_gp;
1818                 }
1819         }
1820         spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1821
1822         return NULL;
1823 }
1824
1825 static void core_alua_put_tg_pt_gp_from_name(
1826         struct t10_alua_tg_pt_gp *tg_pt_gp)
1827 {
1828         struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
1829
1830         spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1831         atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
1832         spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1833 }
1834
1835 static void __target_attach_tg_pt_gp(struct se_lun *lun,
1836                 struct t10_alua_tg_pt_gp *tg_pt_gp)
1837 {
1838         struct se_dev_entry *se_deve;
1839
1840         assert_spin_locked(&lun->lun_tg_pt_gp_lock);
1841
1842         spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1843         lun->lun_tg_pt_gp = tg_pt_gp;
1844         list_add_tail(&lun->lun_tg_pt_gp_link, &tg_pt_gp->tg_pt_gp_lun_list);
1845         tg_pt_gp->tg_pt_gp_members++;
1846         spin_lock(&lun->lun_deve_lock);
1847         list_for_each_entry(se_deve, &lun->lun_deve_list, lun_link)
1848                 core_scsi3_ua_allocate(se_deve, 0x3f,
1849                                        ASCQ_3FH_INQUIRY_DATA_HAS_CHANGED);
1850         spin_unlock(&lun->lun_deve_lock);
1851         spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1852 }
1853
1854 void target_attach_tg_pt_gp(struct se_lun *lun,
1855                 struct t10_alua_tg_pt_gp *tg_pt_gp)
1856 {
1857         spin_lock(&lun->lun_tg_pt_gp_lock);
1858         __target_attach_tg_pt_gp(lun, tg_pt_gp);
1859         spin_unlock(&lun->lun_tg_pt_gp_lock);
1860 }
1861
1862 static void __target_detach_tg_pt_gp(struct se_lun *lun,
1863                 struct t10_alua_tg_pt_gp *tg_pt_gp)
1864 {
1865         assert_spin_locked(&lun->lun_tg_pt_gp_lock);
1866
1867         spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1868         list_del_init(&lun->lun_tg_pt_gp_link);
1869         tg_pt_gp->tg_pt_gp_members--;
1870         spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1871
1872         lun->lun_tg_pt_gp = NULL;
1873 }
1874
1875 void target_detach_tg_pt_gp(struct se_lun *lun)
1876 {
1877         struct t10_alua_tg_pt_gp *tg_pt_gp;
1878
1879         spin_lock(&lun->lun_tg_pt_gp_lock);
1880         tg_pt_gp = lun->lun_tg_pt_gp;
1881         if (tg_pt_gp)
1882                 __target_detach_tg_pt_gp(lun, tg_pt_gp);
1883         spin_unlock(&lun->lun_tg_pt_gp_lock);
1884 }
1885
1886 ssize_t core_alua_show_tg_pt_gp_info(struct se_lun *lun, char *page)
1887 {
1888         struct config_item *tg_pt_ci;
1889         struct t10_alua_tg_pt_gp *tg_pt_gp;
1890         ssize_t len = 0;
1891
1892         spin_lock(&lun->lun_tg_pt_gp_lock);
1893         tg_pt_gp = lun->lun_tg_pt_gp;
1894         if (tg_pt_gp) {
1895                 tg_pt_ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1896                 len += sprintf(page, "TG Port Alias: %s\nTG Port Group ID:"
1897                         " %hu\nTG Port Primary Access State: %s\nTG Port "
1898                         "Primary Access Status: %s\nTG Port Secondary Access"
1899                         " State: %s\nTG Port Secondary Access Status: %s\n",
1900                         config_item_name(tg_pt_ci), tg_pt_gp->tg_pt_gp_id,
1901                         core_alua_dump_state(
1902                                 tg_pt_gp->tg_pt_gp_alua_access_state),
1903                         core_alua_dump_status(
1904                                 tg_pt_gp->tg_pt_gp_alua_access_status),
1905                         atomic_read(&lun->lun_tg_pt_secondary_offline) ?
1906                         "Offline" : "None",
1907                         core_alua_dump_status(lun->lun_tg_pt_secondary_stat));
1908         }
1909         spin_unlock(&lun->lun_tg_pt_gp_lock);
1910
1911         return len;
1912 }
1913
1914 ssize_t core_alua_store_tg_pt_gp_info(
1915         struct se_lun *lun,
1916         const char *page,
1917         size_t count)
1918 {
1919         struct se_portal_group *tpg = lun->lun_tpg;
1920         /*
1921          * rcu_dereference_raw protected by se_lun->lun_group symlink
1922          * reference to se_device->dev_group.
1923          */
1924         struct se_device *dev = rcu_dereference_raw(lun->lun_se_dev);
1925         struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *tg_pt_gp_new = NULL;
1926         unsigned char buf[TG_PT_GROUP_NAME_BUF];
1927         int move = 0;
1928
1929         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA ||
1930             (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
1931                 return -ENODEV;
1932
1933         if (count > TG_PT_GROUP_NAME_BUF) {
1934                 pr_err("ALUA Target Port Group alias too large!\n");
1935                 return -EINVAL;
1936         }
1937         memset(buf, 0, TG_PT_GROUP_NAME_BUF);
1938         memcpy(buf, page, count);
1939         /*
1940          * Any ALUA target port group alias besides "NULL" means we will be
1941          * making a new group association.
1942          */
1943         if (strcmp(strstrip(buf), "NULL")) {
1944                 /*
1945                  * core_alua_get_tg_pt_gp_by_name() will increment reference to
1946                  * struct t10_alua_tg_pt_gp.  This reference is released with
1947                  * core_alua_put_tg_pt_gp_from_name() below.
1948                  */
1949                 tg_pt_gp_new = core_alua_get_tg_pt_gp_by_name(dev,
1950                                         strstrip(buf));
1951                 if (!tg_pt_gp_new)
1952                         return -ENODEV;
1953         }
1954
1955         spin_lock(&lun->lun_tg_pt_gp_lock);
1956         tg_pt_gp = lun->lun_tg_pt_gp;
1957         if (tg_pt_gp) {
1958                 /*
1959                  * Clearing an existing tg_pt_gp association, and replacing
1960                  * with the default_tg_pt_gp.
1961                  */
1962                 if (!tg_pt_gp_new) {
1963                         pr_debug("Target_Core_ConfigFS: Moving"
1964                                 " %s/tpgt_%hu/%s from ALUA Target Port Group:"
1965                                 " alua/%s, ID: %hu back to"
1966                                 " default_tg_pt_gp\n",
1967                                 tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1968                                 tpg->se_tpg_tfo->tpg_get_tag(tpg),
1969                                 config_item_name(&lun->lun_group.cg_item),
1970                                 config_item_name(
1971                                         &tg_pt_gp->tg_pt_gp_group.cg_item),
1972                                 tg_pt_gp->tg_pt_gp_id);
1973
1974                         __target_detach_tg_pt_gp(lun, tg_pt_gp);
1975                         __target_attach_tg_pt_gp(lun,
1976                                         dev->t10_alua.default_tg_pt_gp);
1977                         spin_unlock(&lun->lun_tg_pt_gp_lock);
1978
1979                         return count;
1980                 }
1981                 __target_detach_tg_pt_gp(lun, tg_pt_gp);
1982                 move = 1;
1983         }
1984
1985         __target_attach_tg_pt_gp(lun, tg_pt_gp_new);
1986         spin_unlock(&lun->lun_tg_pt_gp_lock);
1987         pr_debug("Target_Core_ConfigFS: %s %s/tpgt_%hu/%s to ALUA"
1988                 " Target Port Group: alua/%s, ID: %hu\n", (move) ?
1989                 "Moving" : "Adding", tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1990                 tpg->se_tpg_tfo->tpg_get_tag(tpg),
1991                 config_item_name(&lun->lun_group.cg_item),
1992                 config_item_name(&tg_pt_gp_new->tg_pt_gp_group.cg_item),
1993                 tg_pt_gp_new->tg_pt_gp_id);
1994
1995         core_alua_put_tg_pt_gp_from_name(tg_pt_gp_new);
1996         return count;
1997 }
1998
1999 ssize_t core_alua_show_access_type(
2000         struct t10_alua_tg_pt_gp *tg_pt_gp,
2001         char *page)
2002 {
2003         if ((tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICIT_ALUA) &&
2004             (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICIT_ALUA))
2005                 return sprintf(page, "Implicit and Explicit\n");
2006         else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICIT_ALUA)
2007                 return sprintf(page, "Implicit\n");
2008         else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICIT_ALUA)
2009                 return sprintf(page, "Explicit\n");
2010         else
2011                 return sprintf(page, "None\n");
2012 }
2013
2014 ssize_t core_alua_store_access_type(
2015         struct t10_alua_tg_pt_gp *tg_pt_gp,
2016         const char *page,
2017         size_t count)
2018 {
2019         unsigned long tmp;
2020         int ret;
2021
2022         ret = kstrtoul(page, 0, &tmp);
2023         if (ret < 0) {
2024                 pr_err("Unable to extract alua_access_type\n");
2025                 return ret;
2026         }
2027         if ((tmp != 0) && (tmp != 1) && (tmp != 2) && (tmp != 3)) {
2028                 pr_err("Illegal value for alua_access_type:"
2029                                 " %lu\n", tmp);
2030                 return -EINVAL;
2031         }
2032         if (tmp == 3)
2033                 tg_pt_gp->tg_pt_gp_alua_access_type =
2034                         TPGS_IMPLICIT_ALUA | TPGS_EXPLICIT_ALUA;
2035         else if (tmp == 2)
2036                 tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_EXPLICIT_ALUA;
2037         else if (tmp == 1)
2038                 tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_IMPLICIT_ALUA;
2039         else
2040                 tg_pt_gp->tg_pt_gp_alua_access_type = 0;
2041
2042         return count;
2043 }
2044
2045 ssize_t core_alua_show_nonop_delay_msecs(
2046         struct t10_alua_tg_pt_gp *tg_pt_gp,
2047         char *page)
2048 {
2049         return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_nonop_delay_msecs);
2050 }
2051
2052 ssize_t core_alua_store_nonop_delay_msecs(
2053         struct t10_alua_tg_pt_gp *tg_pt_gp,
2054         const char *page,
2055         size_t count)
2056 {
2057         unsigned long tmp;
2058         int ret;
2059
2060         ret = kstrtoul(page, 0, &tmp);
2061         if (ret < 0) {
2062                 pr_err("Unable to extract nonop_delay_msecs\n");
2063                 return ret;
2064         }
2065         if (tmp > ALUA_MAX_NONOP_DELAY_MSECS) {
2066                 pr_err("Passed nonop_delay_msecs: %lu, exceeds"
2067                         " ALUA_MAX_NONOP_DELAY_MSECS: %d\n", tmp,
2068                         ALUA_MAX_NONOP_DELAY_MSECS);
2069                 return -EINVAL;
2070         }
2071         tg_pt_gp->tg_pt_gp_nonop_delay_msecs = (int)tmp;
2072
2073         return count;
2074 }
2075
2076 ssize_t core_alua_show_trans_delay_msecs(
2077         struct t10_alua_tg_pt_gp *tg_pt_gp,
2078         char *page)
2079 {
2080         return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_trans_delay_msecs);
2081 }
2082
2083 ssize_t core_alua_store_trans_delay_msecs(
2084         struct t10_alua_tg_pt_gp *tg_pt_gp,
2085         const char *page,
2086         size_t count)
2087 {
2088         unsigned long tmp;
2089         int ret;
2090
2091         ret = kstrtoul(page, 0, &tmp);
2092         if (ret < 0) {
2093                 pr_err("Unable to extract trans_delay_msecs\n");
2094                 return ret;
2095         }
2096         if (tmp > ALUA_MAX_TRANS_DELAY_MSECS) {
2097                 pr_err("Passed trans_delay_msecs: %lu, exceeds"
2098                         " ALUA_MAX_TRANS_DELAY_MSECS: %d\n", tmp,
2099                         ALUA_MAX_TRANS_DELAY_MSECS);
2100                 return -EINVAL;
2101         }
2102         tg_pt_gp->tg_pt_gp_trans_delay_msecs = (int)tmp;
2103
2104         return count;
2105 }
2106
2107 ssize_t core_alua_show_implicit_trans_secs(
2108         struct t10_alua_tg_pt_gp *tg_pt_gp,
2109         char *page)
2110 {
2111         return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_implicit_trans_secs);
2112 }
2113
2114 ssize_t core_alua_store_implicit_trans_secs(
2115         struct t10_alua_tg_pt_gp *tg_pt_gp,
2116         const char *page,
2117         size_t count)
2118 {
2119         unsigned long tmp;
2120         int ret;
2121
2122         ret = kstrtoul(page, 0, &tmp);
2123         if (ret < 0) {
2124                 pr_err("Unable to extract implicit_trans_secs\n");
2125                 return ret;
2126         }
2127         if (tmp > ALUA_MAX_IMPLICIT_TRANS_SECS) {
2128                 pr_err("Passed implicit_trans_secs: %lu, exceeds"
2129                         " ALUA_MAX_IMPLICIT_TRANS_SECS: %d\n", tmp,
2130                         ALUA_MAX_IMPLICIT_TRANS_SECS);
2131                 return  -EINVAL;
2132         }
2133         tg_pt_gp->tg_pt_gp_implicit_trans_secs = (int)tmp;
2134
2135         return count;
2136 }
2137
2138 ssize_t core_alua_show_preferred_bit(
2139         struct t10_alua_tg_pt_gp *tg_pt_gp,
2140         char *page)
2141 {
2142         return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_pref);
2143 }
2144
2145 ssize_t core_alua_store_preferred_bit(
2146         struct t10_alua_tg_pt_gp *tg_pt_gp,
2147         const char *page,
2148         size_t count)
2149 {
2150         unsigned long tmp;
2151         int ret;
2152
2153         ret = kstrtoul(page, 0, &tmp);
2154         if (ret < 0) {
2155                 pr_err("Unable to extract preferred ALUA value\n");
2156                 return ret;
2157         }
2158         if ((tmp != 0) && (tmp != 1)) {
2159                 pr_err("Illegal value for preferred ALUA: %lu\n", tmp);
2160                 return -EINVAL;
2161         }
2162         tg_pt_gp->tg_pt_gp_pref = (int)tmp;
2163
2164         return count;
2165 }
2166
2167 ssize_t core_alua_show_offline_bit(struct se_lun *lun, char *page)
2168 {
2169         return sprintf(page, "%d\n",
2170                 atomic_read(&lun->lun_tg_pt_secondary_offline));
2171 }
2172
2173 ssize_t core_alua_store_offline_bit(
2174         struct se_lun *lun,
2175         const char *page,
2176         size_t count)
2177 {
2178         /*
2179          * rcu_dereference_raw protected by se_lun->lun_group symlink
2180          * reference to se_device->dev_group.
2181          */
2182         struct se_device *dev = rcu_dereference_raw(lun->lun_se_dev);
2183         unsigned long tmp;
2184         int ret;
2185
2186         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA ||
2187             (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
2188                 return -ENODEV;
2189
2190         ret = kstrtoul(page, 0, &tmp);
2191         if (ret < 0) {
2192                 pr_err("Unable to extract alua_tg_pt_offline value\n");
2193                 return ret;
2194         }
2195         if ((tmp != 0) && (tmp != 1)) {
2196                 pr_err("Illegal value for alua_tg_pt_offline: %lu\n",
2197                                 tmp);
2198                 return -EINVAL;
2199         }
2200
2201         ret = core_alua_set_tg_pt_secondary_state(lun, 0, (int)tmp);
2202         if (ret < 0)
2203                 return -EINVAL;
2204
2205         return count;
2206 }
2207
2208 ssize_t core_alua_show_secondary_status(
2209         struct se_lun *lun,
2210         char *page)
2211 {
2212         return sprintf(page, "%d\n", lun->lun_tg_pt_secondary_stat);
2213 }
2214
2215 ssize_t core_alua_store_secondary_status(
2216         struct se_lun *lun,
2217         const char *page,
2218         size_t count)
2219 {
2220         unsigned long tmp;
2221         int ret;
2222
2223         ret = kstrtoul(page, 0, &tmp);
2224         if (ret < 0) {
2225                 pr_err("Unable to extract alua_tg_pt_status\n");
2226                 return ret;
2227         }
2228         if ((tmp != ALUA_STATUS_NONE) &&
2229             (tmp != ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG) &&
2230             (tmp != ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA)) {
2231                 pr_err("Illegal value for alua_tg_pt_status: %lu\n",
2232                                 tmp);
2233                 return -EINVAL;
2234         }
2235         lun->lun_tg_pt_secondary_stat = (int)tmp;
2236
2237         return count;
2238 }
2239
2240 ssize_t core_alua_show_secondary_write_metadata(
2241         struct se_lun *lun,
2242         char *page)
2243 {
2244         return sprintf(page, "%d\n", lun->lun_tg_pt_secondary_write_md);
2245 }
2246
2247 ssize_t core_alua_store_secondary_write_metadata(
2248         struct se_lun *lun,
2249         const char *page,
2250         size_t count)
2251 {
2252         unsigned long tmp;
2253         int ret;
2254
2255         ret = kstrtoul(page, 0, &tmp);
2256         if (ret < 0) {
2257                 pr_err("Unable to extract alua_tg_pt_write_md\n");
2258                 return ret;
2259         }
2260         if ((tmp != 0) && (tmp != 1)) {
2261                 pr_err("Illegal value for alua_tg_pt_write_md:"
2262                                 " %lu\n", tmp);
2263                 return -EINVAL;
2264         }
2265         lun->lun_tg_pt_secondary_write_md = (int)tmp;
2266
2267         return count;
2268 }
2269
2270 int core_setup_alua(struct se_device *dev)
2271 {
2272         if (!(dev->transport->transport_flags &
2273              TRANSPORT_FLAG_PASSTHROUGH_ALUA) &&
2274             !(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)) {
2275                 struct t10_alua_lu_gp_member *lu_gp_mem;
2276
2277                 /*
2278                  * Associate this struct se_device with the default ALUA
2279                  * LUN Group.
2280                  */
2281                 lu_gp_mem = core_alua_allocate_lu_gp_mem(dev);
2282                 if (IS_ERR(lu_gp_mem))
2283                         return PTR_ERR(lu_gp_mem);
2284
2285                 spin_lock(&lu_gp_mem->lu_gp_mem_lock);
2286                 __core_alua_attach_lu_gp_mem(lu_gp_mem,
2287                                 default_lu_gp);
2288                 spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
2289
2290                 pr_debug("%s: Adding to default ALUA LU Group:"
2291                         " core/alua/lu_gps/default_lu_gp\n",
2292                         dev->transport->name);
2293         }
2294
2295         return 0;
2296 }