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Hannes Reinecke057ea7c2008-07-17 16:53:21 -07001/*
2 * Generic SCSI-3 ALUA SCSI Device Handler
3 *
Hannes Reinecke69723d12010-09-24 15:57:04 +02004 * Copyright (C) 2007-2010 Hannes Reinecke, SUSE Linux Products GmbH.
Hannes Reinecke057ea7c2008-07-17 16:53:21 -07005 * All rights reserved.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
20 *
21 */
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090022#include <linux/slab.h>
Hannes Reinecke69723d12010-09-24 15:57:04 +020023#include <linux/delay.h>
Paul Gortmakeracf3368f2011-05-27 09:47:43 -040024#include <linux/module.h>
Hannes Reineckea7089772015-12-01 10:16:52 +010025#include <asm/unaligned.h>
Hannes Reinecke057ea7c2008-07-17 16:53:21 -070026#include <scsi/scsi.h>
Hannes Reineckecb0a1682016-03-03 07:54:09 +010027#include <scsi/scsi_proto.h>
Hannes Reinecke80bd68d2015-12-01 10:16:47 +010028#include <scsi/scsi_dbg.h>
Hannes Reinecke057ea7c2008-07-17 16:53:21 -070029#include <scsi/scsi_eh.h>
30#include <scsi/scsi_dh.h>
31
32#define ALUA_DH_NAME "alua"
Hannes Reineckee79c82c2016-02-19 09:17:20 +010033#define ALUA_DH_VER "2.0"
Hannes Reinecke057ea7c2008-07-17 16:53:21 -070034
Hannes Reinecke057ea7c2008-07-17 16:53:21 -070035#define TPGS_SUPPORT_NONE 0x00
36#define TPGS_SUPPORT_OPTIMIZED 0x01
37#define TPGS_SUPPORT_NONOPTIMIZED 0x02
38#define TPGS_SUPPORT_STANDBY 0x04
39#define TPGS_SUPPORT_UNAVAILABLE 0x08
Hannes Reinecke69723d12010-09-24 15:57:04 +020040#define TPGS_SUPPORT_LBA_DEPENDENT 0x10
Hannes Reinecke057ea7c2008-07-17 16:53:21 -070041#define TPGS_SUPPORT_OFFLINE 0x40
42#define TPGS_SUPPORT_TRANSITION 0x80
43
Rob Evers3588c5a2012-05-18 14:08:54 -040044#define RTPG_FMT_MASK 0x70
45#define RTPG_FMT_EXT_HDR 0x10
46
Hannes Reinecke057ea7c2008-07-17 16:53:21 -070047#define TPGS_MODE_UNINITIALIZED -1
48#define TPGS_MODE_NONE 0x0
49#define TPGS_MODE_IMPLICIT 0x1
50#define TPGS_MODE_EXPLICIT 0x2
51
Hannes Reineckec49c8342016-02-19 09:17:03 +010052#define ALUA_RTPG_SIZE 128
Rob Evers3588c5a2012-05-18 14:08:54 -040053#define ALUA_FAILOVER_TIMEOUT 60
Hannes Reinecke057ea7c2008-07-17 16:53:21 -070054#define ALUA_FAILOVER_RETRIES 5
Hannes Reinecke03197b62016-02-19 09:17:10 +010055#define ALUA_RTPG_DELAY_MSECS 5
Hannes Reinecke057ea7c2008-07-17 16:53:21 -070056
Hannes Reinecke6c4fc042015-12-01 10:16:51 +010057/* device handler flags */
Hannes Reinecke03197b62016-02-19 09:17:10 +010058#define ALUA_OPTIMIZE_STPG 0x01
59#define ALUA_RTPG_EXT_HDR_UNSUPP 0x02
Hannes Reinecke00642a12016-02-19 09:17:11 +010060#define ALUA_SYNC_STPG 0x04
Hannes Reinecke03197b62016-02-19 09:17:10 +010061/* State machine flags */
62#define ALUA_PG_RUN_RTPG 0x10
63#define ALUA_PG_RUN_STPG 0x20
64#define ALUA_PG_RUNNING 0x40
Moger, Babu4335d092012-03-27 20:55:49 +000065
Hannes Reineckeaa90f492016-02-19 09:17:08 +010066static uint optimize_stpg;
67module_param(optimize_stpg, uint, S_IRUGO|S_IWUSR);
68MODULE_PARM_DESC(optimize_stpg, "Allow use of a non-optimized path, rather than sending a STPG, when implicit TPGS is supported (0=No,1=Yes). Default is 0.");
69
Hannes Reinecke43394c62016-02-19 09:17:04 +010070static LIST_HEAD(port_group_list);
71static DEFINE_SPINLOCK(port_group_lock);
Hannes Reinecke03197b62016-02-19 09:17:10 +010072static struct workqueue_struct *kaluad_wq;
Hannes Reinecke00642a12016-02-19 09:17:11 +010073static struct workqueue_struct *kaluad_sync_wq;
Hannes Reinecke43394c62016-02-19 09:17:04 +010074
75struct alua_port_group {
76 struct kref kref;
Hannes Reinecke03197b62016-02-19 09:17:10 +010077 struct rcu_head rcu;
Hannes Reinecke43394c62016-02-19 09:17:04 +010078 struct list_head node;
Hannes Reineckecb0a1682016-03-03 07:54:09 +010079 struct list_head dh_list;
Hannes Reinecke00472202016-02-19 09:17:05 +010080 unsigned char device_id_str[256];
81 int device_id_len;
Hannes Reinecke057ea7c2008-07-17 16:53:21 -070082 int group_id;
Hannes Reinecke057ea7c2008-07-17 16:53:21 -070083 int tpgs;
84 int state;
Moger, Babudcd3a752012-03-27 20:56:08 +000085 int pref;
Moger, Babu4335d092012-03-27 20:55:49 +000086 unsigned flags; /* used for optimizing STPG */
Rob Evers3588c5a2012-05-18 14:08:54 -040087 unsigned char transition_tmo;
Hannes Reinecke03197b62016-02-19 09:17:10 +010088 unsigned long expiry;
89 unsigned long interval;
90 struct delayed_work rtpg_work;
91 spinlock_t lock;
92 struct list_head rtpg_list;
93 struct scsi_device *rtpg_sdev;
Hannes Reinecke43394c62016-02-19 09:17:04 +010094};
95
96struct alua_dh_data {
Hannes Reineckecb0a1682016-03-03 07:54:09 +010097 struct list_head node;
Hannes Reinecke43394c62016-02-19 09:17:04 +010098 struct alua_port_group *pg;
99 int group_id;
Hannes Reinecke03197b62016-02-19 09:17:10 +0100100 spinlock_t pg_lock;
Chandra Seetharaman96e65862009-10-21 09:23:04 -0700101 struct scsi_device *sdev;
Hannes Reinecke03197b62016-02-19 09:17:10 +0100102 int init_error;
103 struct mutex init_mutex;
104};
105
106struct alua_queue_data {
107 struct list_head entry;
Chandra Seetharaman96e65862009-10-21 09:23:04 -0700108 activate_complete callback_fn;
109 void *callback_data;
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700110};
111
112#define ALUA_POLICY_SWITCH_CURRENT 0
113#define ALUA_POLICY_SWITCH_ALL 1
114
Hannes Reinecke03197b62016-02-19 09:17:10 +0100115static void alua_rtpg_work(struct work_struct *work);
116static void alua_rtpg_queue(struct alua_port_group *pg,
117 struct scsi_device *sdev,
Hannes Reinecke2b358652016-02-19 09:17:13 +0100118 struct alua_queue_data *qdata, bool force);
119static void alua_check(struct scsi_device *sdev, bool force);
Chandra Seetharaman96e65862009-10-21 09:23:04 -0700120
Hannes Reinecke43394c62016-02-19 09:17:04 +0100121static void release_port_group(struct kref *kref)
122{
123 struct alua_port_group *pg;
124
125 pg = container_of(kref, struct alua_port_group, kref);
Hannes Reinecke03197b62016-02-19 09:17:10 +0100126 if (pg->rtpg_sdev)
127 flush_delayed_work(&pg->rtpg_work);
Hannes Reinecke43394c62016-02-19 09:17:04 +0100128 spin_lock(&port_group_lock);
129 list_del(&pg->node);
130 spin_unlock(&port_group_lock);
Hannes Reinecke03197b62016-02-19 09:17:10 +0100131 kfree_rcu(pg, rcu);
Hannes Reinecke43394c62016-02-19 09:17:04 +0100132}
133
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700134/*
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700135 * submit_rtpg - Issue a REPORT TARGET GROUP STATES command
136 * @sdev: sdev the command should be sent to
137 */
Hannes Reinecke40bb61a2016-02-19 09:17:02 +0100138static int submit_rtpg(struct scsi_device *sdev, unsigned char *buff,
139 int bufflen, struct scsi_sense_hdr *sshdr, int flags)
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700140{
Hannes Reinecke40bb61a2016-02-19 09:17:02 +0100141 u8 cdb[COMMAND_SIZE(MAINTENANCE_IN)];
142 int req_flags = REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT |
143 REQ_FAILFAST_DRIVER;
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700144
145 /* Prepare the command. */
Hannes Reinecke40bb61a2016-02-19 09:17:02 +0100146 memset(cdb, 0x0, COMMAND_SIZE(MAINTENANCE_IN));
147 cdb[0] = MAINTENANCE_IN;
Hannes Reinecked42ae5f2016-02-19 09:16:58 +0100148 if (!(flags & ALUA_RTPG_EXT_HDR_UNSUPP))
Hannes Reinecke40bb61a2016-02-19 09:17:02 +0100149 cdb[1] = MI_REPORT_TARGET_PGS | MI_EXT_HDR_PARAM_FMT;
Rob Evers8e67ce62012-05-18 14:08:55 -0400150 else
Hannes Reinecke40bb61a2016-02-19 09:17:02 +0100151 cdb[1] = MI_REPORT_TARGET_PGS;
152 put_unaligned_be32(bufflen, &cdb[6]);
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700153
Hannes Reinecke40bb61a2016-02-19 09:17:02 +0100154 return scsi_execute_req_flags(sdev, cdb, DMA_FROM_DEVICE,
155 buff, bufflen, sshdr,
156 ALUA_FAILOVER_TIMEOUT * HZ,
Christoph Hellwige8064022016-10-20 15:12:13 +0200157 ALUA_FAILOVER_RETRIES, NULL,
158 req_flags, 0);
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700159}
160
161/*
Hannes Reineckeb2460752016-02-19 09:17:00 +0100162 * submit_stpg - Issue a SET TARGET PORT GROUP command
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700163 *
164 * Currently we're only setting the current target port group state
165 * to 'active/optimized' and let the array firmware figure out
166 * the states of the remaining groups.
167 */
Hannes Reinecke40bb61a2016-02-19 09:17:02 +0100168static int submit_stpg(struct scsi_device *sdev, int group_id,
169 struct scsi_sense_hdr *sshdr)
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700170{
Hannes Reinecke40bb61a2016-02-19 09:17:02 +0100171 u8 cdb[COMMAND_SIZE(MAINTENANCE_OUT)];
Hannes Reineckeb2460752016-02-19 09:17:00 +0100172 unsigned char stpg_data[8];
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700173 int stpg_len = 8;
Hannes Reinecke40bb61a2016-02-19 09:17:02 +0100174 int req_flags = REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT |
175 REQ_FAILFAST_DRIVER;
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700176
177 /* Prepare the data buffer */
Hannes Reineckeb2460752016-02-19 09:17:00 +0100178 memset(stpg_data, 0, stpg_len);
Hannes Reinecke5115fc72016-03-03 07:54:08 +0100179 stpg_data[4] = SCSI_ACCESS_STATE_OPTIMAL;
Hannes Reineckeb2460752016-02-19 09:17:00 +0100180 put_unaligned_be16(group_id, &stpg_data[6]);
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700181
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700182 /* Prepare the command. */
Hannes Reinecke40bb61a2016-02-19 09:17:02 +0100183 memset(cdb, 0x0, COMMAND_SIZE(MAINTENANCE_OUT));
184 cdb[0] = MAINTENANCE_OUT;
185 cdb[1] = MO_SET_TARGET_PGS;
186 put_unaligned_be32(stpg_len, &cdb[6]);
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700187
Hannes Reinecke40bb61a2016-02-19 09:17:02 +0100188 return scsi_execute_req_flags(sdev, cdb, DMA_TO_DEVICE,
189 stpg_data, stpg_len,
190 sshdr, ALUA_FAILOVER_TIMEOUT * HZ,
Christoph Hellwige8064022016-10-20 15:12:13 +0200191 ALUA_FAILOVER_RETRIES, NULL,
192 req_flags, 0);
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700193}
194
Bart Van Assche1f275f92016-04-14 10:27:14 -0700195static struct alua_port_group *alua_find_get_pg(char *id_str, size_t id_size,
196 int group_id)
Hannes Reinecke00472202016-02-19 09:17:05 +0100197{
198 struct alua_port_group *pg;
199
Hannes Reineckefe8b9532016-05-06 10:34:35 +0200200 if (!id_str || !id_size || !strlen(id_str))
201 return NULL;
202
Hannes Reinecke00472202016-02-19 09:17:05 +0100203 list_for_each_entry(pg, &port_group_list, node) {
204 if (pg->group_id != group_id)
205 continue;
Hannes Reineckefe8b9532016-05-06 10:34:35 +0200206 if (!pg->device_id_len || pg->device_id_len != id_size)
Hannes Reinecke00472202016-02-19 09:17:05 +0100207 continue;
208 if (strncmp(pg->device_id_str, id_str, id_size))
209 continue;
210 if (!kref_get_unless_zero(&pg->kref))
211 continue;
212 return pg;
213 }
214
215 return NULL;
216}
217
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700218/*
Hannes Reinecke43394c62016-02-19 09:17:04 +0100219 * alua_alloc_pg - Allocate a new port_group structure
220 * @sdev: scsi device
221 * @h: alua device_handler data
222 * @group_id: port group id
223 *
224 * Allocate a new port_group structure for a given
225 * device.
226 */
Bart Van Assche1f275f92016-04-14 10:27:14 -0700227static struct alua_port_group *alua_alloc_pg(struct scsi_device *sdev,
228 int group_id, int tpgs)
Hannes Reinecke43394c62016-02-19 09:17:04 +0100229{
Hannes Reinecke00472202016-02-19 09:17:05 +0100230 struct alua_port_group *pg, *tmp_pg;
Hannes Reinecke43394c62016-02-19 09:17:04 +0100231
232 pg = kzalloc(sizeof(struct alua_port_group), GFP_KERNEL);
233 if (!pg)
Hannes Reinecke00472202016-02-19 09:17:05 +0100234 return ERR_PTR(-ENOMEM);
Hannes Reinecke43394c62016-02-19 09:17:04 +0100235
Hannes Reinecke00472202016-02-19 09:17:05 +0100236 pg->device_id_len = scsi_vpd_lun_id(sdev, pg->device_id_str,
237 sizeof(pg->device_id_str));
238 if (pg->device_id_len <= 0) {
239 /*
Hannes Reineckefe8b9532016-05-06 10:34:35 +0200240 * TPGS supported but no device identification found.
241 * Generate private device identification.
Hannes Reinecke00472202016-02-19 09:17:05 +0100242 */
Hannes Reinecke00472202016-02-19 09:17:05 +0100243 sdev_printk(KERN_INFO, sdev,
244 "%s: No device descriptors found\n",
245 ALUA_DH_NAME);
Hannes Reineckefe8b9532016-05-06 10:34:35 +0200246 pg->device_id_str[0] = '\0';
247 pg->device_id_len = 0;
Hannes Reinecke00472202016-02-19 09:17:05 +0100248 }
Hannes Reinecke43394c62016-02-19 09:17:04 +0100249 pg->group_id = group_id;
250 pg->tpgs = tpgs;
Hannes Reinecke5115fc72016-03-03 07:54:08 +0100251 pg->state = SCSI_ACCESS_STATE_OPTIMAL;
Hannes Reineckeaa90f492016-02-19 09:17:08 +0100252 if (optimize_stpg)
253 pg->flags |= ALUA_OPTIMIZE_STPG;
Hannes Reinecke43394c62016-02-19 09:17:04 +0100254 kref_init(&pg->kref);
Hannes Reinecke03197b62016-02-19 09:17:10 +0100255 INIT_DELAYED_WORK(&pg->rtpg_work, alua_rtpg_work);
256 INIT_LIST_HEAD(&pg->rtpg_list);
257 INIT_LIST_HEAD(&pg->node);
Hannes Reineckecb0a1682016-03-03 07:54:09 +0100258 INIT_LIST_HEAD(&pg->dh_list);
Hannes Reinecke03197b62016-02-19 09:17:10 +0100259 spin_lock_init(&pg->lock);
Hannes Reinecke00472202016-02-19 09:17:05 +0100260
Hannes Reinecke43394c62016-02-19 09:17:04 +0100261 spin_lock(&port_group_lock);
Hannes Reinecke00472202016-02-19 09:17:05 +0100262 tmp_pg = alua_find_get_pg(pg->device_id_str, pg->device_id_len,
263 group_id);
264 if (tmp_pg) {
265 spin_unlock(&port_group_lock);
266 kfree(pg);
267 return tmp_pg;
268 }
269
Hannes Reinecke43394c62016-02-19 09:17:04 +0100270 list_add(&pg->node, &port_group_list);
271 spin_unlock(&port_group_lock);
272
273 return pg;
274}
275
276/*
Hannes Reinecked7c48fe2011-08-24 10:51:13 +0200277 * alua_check_tpgs - Evaluate TPGS setting
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700278 * @sdev: device to be checked
279 *
Hannes Reinecked7c48fe2011-08-24 10:51:13 +0200280 * Examine the TPGS setting of the sdev to find out if ALUA
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700281 * is supported.
282 */
Hannes Reineckead0ea642015-12-01 10:16:53 +0100283static int alua_check_tpgs(struct scsi_device *sdev)
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700284{
Hannes Reineckead0ea642015-12-01 10:16:53 +0100285 int tpgs = TPGS_MODE_NONE;
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700286
Hannes Reineckedb5a6a62015-12-01 10:16:43 +0100287 /*
288 * ALUA support for non-disk devices is fraught with
289 * difficulties, so disable it for now.
290 */
291 if (sdev->type != TYPE_DISK) {
Hannes Reineckedb5a6a62015-12-01 10:16:43 +0100292 sdev_printk(KERN_INFO, sdev,
293 "%s: disable for non-disk devices\n",
294 ALUA_DH_NAME);
Hannes Reineckead0ea642015-12-01 10:16:53 +0100295 return tpgs;
Hannes Reineckedb5a6a62015-12-01 10:16:43 +0100296 }
297
Hannes Reineckead0ea642015-12-01 10:16:53 +0100298 tpgs = scsi_device_tpgs(sdev);
299 switch (tpgs) {
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700300 case TPGS_MODE_EXPLICIT|TPGS_MODE_IMPLICIT:
301 sdev_printk(KERN_INFO, sdev,
302 "%s: supports implicit and explicit TPGS\n",
303 ALUA_DH_NAME);
304 break;
305 case TPGS_MODE_EXPLICIT:
306 sdev_printk(KERN_INFO, sdev, "%s: supports explicit TPGS\n",
307 ALUA_DH_NAME);
308 break;
309 case TPGS_MODE_IMPLICIT:
310 sdev_printk(KERN_INFO, sdev, "%s: supports implicit TPGS\n",
311 ALUA_DH_NAME);
312 break;
Hannes Reinecke6cc05d42015-12-01 10:16:45 +0100313 case TPGS_MODE_NONE:
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700314 sdev_printk(KERN_INFO, sdev, "%s: not supported\n",
315 ALUA_DH_NAME);
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700316 break;
Hannes Reinecke6cc05d42015-12-01 10:16:45 +0100317 default:
318 sdev_printk(KERN_INFO, sdev,
319 "%s: unsupported TPGS setting %d\n",
Hannes Reineckead0ea642015-12-01 10:16:53 +0100320 ALUA_DH_NAME, tpgs);
321 tpgs = TPGS_MODE_NONE;
Hannes Reinecke6cc05d42015-12-01 10:16:45 +0100322 break;
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700323 }
324
Hannes Reineckead0ea642015-12-01 10:16:53 +0100325 return tpgs;
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700326}
327
328/*
Hannes Reinecke9b80dce2015-12-01 10:16:44 +0100329 * alua_check_vpd - Evaluate INQUIRY vpd page 0x83
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700330 * @sdev: device to be checked
331 *
332 * Extract the relative target port and the target port group
333 * descriptor from the list of identificators.
334 */
Hannes Reineckea4253fd2016-02-19 09:17:06 +0100335static int alua_check_vpd(struct scsi_device *sdev, struct alua_dh_data *h,
336 int tpgs)
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700337{
Hannes Reinecke83ea0e52015-12-01 10:16:58 +0100338 int rel_port = -1, group_id;
Hannes Reinecke03197b62016-02-19 09:17:10 +0100339 struct alua_port_group *pg, *old_pg = NULL;
Dan Carpenter100bcb82016-03-11 14:19:03 +0300340 bool pg_updated = false;
Hannes Reineckecb0a1682016-03-03 07:54:09 +0100341 unsigned long flags;
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700342
Hannes Reinecke83ea0e52015-12-01 10:16:58 +0100343 group_id = scsi_vpd_tpg_id(sdev, &rel_port);
344 if (group_id < 0) {
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700345 /*
346 * Internal error; TPGS supported but required
347 * VPD identification descriptors not present.
348 * Disable ALUA support
349 */
350 sdev_printk(KERN_INFO, sdev,
351 "%s: No target port descriptors found\n",
352 ALUA_DH_NAME);
Hannes Reinecke9b80dce2015-12-01 10:16:44 +0100353 return SCSI_DH_DEV_UNSUPP;
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700354 }
Hannes Reineckea4253fd2016-02-19 09:17:06 +0100355
Hannes Reinecke03197b62016-02-19 09:17:10 +0100356 pg = alua_alloc_pg(sdev, group_id, tpgs);
357 if (IS_ERR(pg)) {
358 if (PTR_ERR(pg) == -ENOMEM)
Hannes Reineckea4253fd2016-02-19 09:17:06 +0100359 return SCSI_DH_NOMEM;
360 return SCSI_DH_DEV_UNSUPP;
361 }
Hannes Reineckefe8b9532016-05-06 10:34:35 +0200362 if (pg->device_id_len)
363 sdev_printk(KERN_INFO, sdev,
364 "%s: device %s port group %x rel port %x\n",
365 ALUA_DH_NAME, pg->device_id_str,
366 group_id, rel_port);
367 else
368 sdev_printk(KERN_INFO, sdev,
369 "%s: port group %x rel port %x\n",
370 ALUA_DH_NAME, group_id, rel_port);
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700371
Hannes Reinecke03197b62016-02-19 09:17:10 +0100372 /* Check for existing port group references */
373 spin_lock(&h->pg_lock);
374 old_pg = h->pg;
375 if (old_pg != pg) {
376 /* port group has changed. Update to new port group */
Hannes Reineckecb0a1682016-03-03 07:54:09 +0100377 if (h->pg) {
378 spin_lock_irqsave(&old_pg->lock, flags);
379 list_del_rcu(&h->node);
380 spin_unlock_irqrestore(&old_pg->lock, flags);
381 }
Hannes Reinecke03197b62016-02-19 09:17:10 +0100382 rcu_assign_pointer(h->pg, pg);
Hannes Reineckecb0a1682016-03-03 07:54:09 +0100383 pg_updated = true;
Hannes Reinecke03197b62016-02-19 09:17:10 +0100384 }
Hannes Reineckecb0a1682016-03-03 07:54:09 +0100385
386 spin_lock_irqsave(&pg->lock, flags);
Hannes Reinecke851cde92016-02-19 09:17:12 +0100387 if (sdev->synchronous_alua)
388 pg->flags |= ALUA_SYNC_STPG;
Hannes Reineckecb0a1682016-03-03 07:54:09 +0100389 if (pg_updated)
390 list_add_rcu(&h->node, &pg->dh_list);
391 spin_unlock_irqrestore(&pg->lock, flags);
392
Hannes Reinecke2b358652016-02-19 09:17:13 +0100393 alua_rtpg_queue(h->pg, sdev, NULL, true);
Hannes Reinecke03197b62016-02-19 09:17:10 +0100394 spin_unlock(&h->pg_lock);
395
396 if (old_pg)
397 kref_put(&old_pg->kref, release_port_group);
398
399 return SCSI_DH_OK;
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700400}
401
Hannes Reinecke5115fc72016-03-03 07:54:08 +0100402static char print_alua_state(unsigned char state)
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700403{
404 switch (state) {
Hannes Reinecke5115fc72016-03-03 07:54:08 +0100405 case SCSI_ACCESS_STATE_OPTIMAL:
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700406 return 'A';
Hannes Reinecke5115fc72016-03-03 07:54:08 +0100407 case SCSI_ACCESS_STATE_ACTIVE:
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700408 return 'N';
Hannes Reinecke5115fc72016-03-03 07:54:08 +0100409 case SCSI_ACCESS_STATE_STANDBY:
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700410 return 'S';
Hannes Reinecke5115fc72016-03-03 07:54:08 +0100411 case SCSI_ACCESS_STATE_UNAVAILABLE:
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700412 return 'U';
Hannes Reinecke5115fc72016-03-03 07:54:08 +0100413 case SCSI_ACCESS_STATE_LBA:
Hannes Reinecke69723d12010-09-24 15:57:04 +0200414 return 'L';
Hannes Reinecke5115fc72016-03-03 07:54:08 +0100415 case SCSI_ACCESS_STATE_OFFLINE:
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700416 return 'O';
Hannes Reinecke5115fc72016-03-03 07:54:08 +0100417 case SCSI_ACCESS_STATE_TRANSITIONING:
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700418 return 'T';
419 default:
420 return 'X';
421 }
422}
423
424static int alua_check_sense(struct scsi_device *sdev,
425 struct scsi_sense_hdr *sense_hdr)
426{
427 switch (sense_hdr->sense_key) {
428 case NOT_READY:
Hannes Reinecke2b358652016-02-19 09:17:13 +0100429 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0a) {
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700430 /*
431 * LUN Not Accessible - ALUA state transition
432 */
Hannes Reinecke2b358652016-02-19 09:17:13 +0100433 alua_check(sdev, false);
434 return NEEDS_RETRY;
435 }
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700436 break;
437 case UNIT_ATTENTION:
Hannes Reinecke2b358652016-02-19 09:17:13 +0100438 if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00) {
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700439 /*
Hannes Reinecke2b358652016-02-19 09:17:13 +0100440 * Power On, Reset, or Bus Device Reset.
441 * Might have obscured a state transition,
442 * so schedule a recheck.
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700443 */
Hannes Reinecke2b358652016-02-19 09:17:13 +0100444 alua_check(sdev, true);
Mike Andersonc7dbb622008-08-12 12:11:57 -0700445 return ADD_TO_MLQUEUE;
Hannes Reinecke2b358652016-02-19 09:17:13 +0100446 }
Stewart, Seanc20ee7b2013-10-15 15:52:39 +0000447 if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x04)
448 /*
449 * Device internal reset
450 */
451 return ADD_TO_MLQUEUE;
Moger, Babu410f02d2011-12-21 18:01:37 -0500452 if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x01)
453 /*
454 * Mode Parameters Changed
455 */
456 return ADD_TO_MLQUEUE;
Hannes Reinecke2b358652016-02-19 09:17:13 +0100457 if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x06) {
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700458 /*
459 * ALUA state changed
460 */
Hannes Reinecke2b358652016-02-19 09:17:13 +0100461 alua_check(sdev, true);
Mike Andersonc7dbb622008-08-12 12:11:57 -0700462 return ADD_TO_MLQUEUE;
Hannes Reinecke2b358652016-02-19 09:17:13 +0100463 }
464 if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x07) {
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700465 /*
466 * Implicit ALUA state transition failed
467 */
Hannes Reinecke2b358652016-02-19 09:17:13 +0100468 alua_check(sdev, true);
Mike Andersonc7dbb622008-08-12 12:11:57 -0700469 return ADD_TO_MLQUEUE;
Hannes Reinecke2b358652016-02-19 09:17:13 +0100470 }
Moger, Babubf819732011-10-06 13:22:07 -0400471 if (sense_hdr->asc == 0x3f && sense_hdr->ascq == 0x03)
472 /*
473 * Inquiry data has changed
474 */
475 return ADD_TO_MLQUEUE;
476 if (sense_hdr->asc == 0x3f && sense_hdr->ascq == 0x0e)
Ilgu Hong4d086f62009-01-30 17:00:11 -0600477 /*
478 * REPORTED_LUNS_DATA_HAS_CHANGED is reported
479 * when switching controllers on targets like
480 * Intel Multi-Flex. We can just retry.
481 */
482 return ADD_TO_MLQUEUE;
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700483 break;
484 }
485
486 return SCSI_RETURN_NOT_HANDLED;
487}
488
489/*
Hannes Reinecke9d2c3032016-02-19 09:17:15 +0100490 * alua_tur - Send a TEST UNIT READY
491 * @sdev: device to which the TEST UNIT READY command should be send
492 *
493 * Send a TEST UNIT READY to @sdev to figure out the device state
494 * Returns SCSI_DH_RETRY if the sense code is NOT READY/ALUA TRANSITIONING,
495 * SCSI_DH_OK if no error occurred, and SCSI_DH_IO otherwise.
496 */
497static int alua_tur(struct scsi_device *sdev)
498{
499 struct scsi_sense_hdr sense_hdr;
500 int retval;
501
502 retval = scsi_test_unit_ready(sdev, ALUA_FAILOVER_TIMEOUT * HZ,
503 ALUA_FAILOVER_RETRIES, &sense_hdr);
504 if (sense_hdr.sense_key == NOT_READY &&
505 sense_hdr.asc == 0x04 && sense_hdr.ascq == 0x0a)
506 return SCSI_DH_RETRY;
507 else if (retval)
508 return SCSI_DH_IO;
509 else
510 return SCSI_DH_OK;
511}
512
513/*
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700514 * alua_rtpg - Evaluate REPORT TARGET GROUP STATES
515 * @sdev: the device to be evaluated.
516 *
517 * Evaluate the Target Port Group State.
518 * Returns SCSI_DH_DEV_OFFLINED if the path is
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300519 * found to be unusable.
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700520 */
Hannes Reinecke28261402016-02-19 09:17:07 +0100521static int alua_rtpg(struct scsi_device *sdev, struct alua_port_group *pg)
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700522{
523 struct scsi_sense_hdr sense_hdr;
Hannes Reineckec57168a2016-02-19 09:17:14 +0100524 struct alua_port_group *tmp_pg;
Hannes Reineckec49c8342016-02-19 09:17:03 +0100525 int len, k, off, valid_states = 0, bufflen = ALUA_RTPG_SIZE;
Hannes Reineckec57168a2016-02-19 09:17:14 +0100526 unsigned char *desc, *buff;
Hannes Reinecke5597caf2015-12-01 10:16:48 +0100527 unsigned err, retval;
Rob Evers3588c5a2012-05-18 14:08:54 -0400528 unsigned int tpg_desc_tbl_off;
529 unsigned char orig_transition_tmo;
Hannes Reineckec57168a2016-02-19 09:17:14 +0100530 unsigned long flags;
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700531
Hannes Reinecke03197b62016-02-19 09:17:10 +0100532 if (!pg->expiry) {
533 unsigned long transition_tmo = ALUA_FAILOVER_TIMEOUT * HZ;
534
535 if (pg->transition_tmo)
536 transition_tmo = pg->transition_tmo * HZ;
537
538 pg->expiry = round_jiffies_up(jiffies + transition_tmo);
539 }
Rob Evers3588c5a2012-05-18 14:08:54 -0400540
Hannes Reineckec49c8342016-02-19 09:17:03 +0100541 buff = kzalloc(bufflen, GFP_KERNEL);
542 if (!buff)
543 return SCSI_DH_DEV_TEMP_BUSY;
544
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700545 retry:
Dan Carpentera4bd8522016-04-14 21:20:34 +0300546 err = 0;
Hannes Reinecke43394c62016-02-19 09:17:04 +0100547 retval = submit_rtpg(sdev, buff, bufflen, &sense_hdr, pg->flags);
Hannes Reinecke40bb61a2016-02-19 09:17:02 +0100548
Hannes Reinecke5597caf2015-12-01 10:16:48 +0100549 if (retval) {
Hannes Reinecke40bb61a2016-02-19 09:17:02 +0100550 if (!scsi_sense_valid(&sense_hdr)) {
Hannes Reinecke5597caf2015-12-01 10:16:48 +0100551 sdev_printk(KERN_INFO, sdev,
552 "%s: rtpg failed, result %d\n",
553 ALUA_DH_NAME, retval);
Hannes Reineckec49c8342016-02-19 09:17:03 +0100554 kfree(buff);
Hannes Reinecke40bb61a2016-02-19 09:17:02 +0100555 if (driver_byte(retval) == DRIVER_ERROR)
Hannes Reinecke5597caf2015-12-01 10:16:48 +0100556 return SCSI_DH_DEV_TEMP_BUSY;
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700557 return SCSI_DH_IO;
Hannes Reinecke5597caf2015-12-01 10:16:48 +0100558 }
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700559
Rob Evers8e67ce62012-05-18 14:08:55 -0400560 /*
561 * submit_rtpg() has failed on existing arrays
562 * when requesting extended header info, and
563 * the array doesn't support extended headers,
564 * even though it shouldn't according to T10.
565 * The retry without rtpg_ext_hdr_req set
566 * handles this.
567 */
Hannes Reinecke43394c62016-02-19 09:17:04 +0100568 if (!(pg->flags & ALUA_RTPG_EXT_HDR_UNSUPP) &&
Rob Evers8e67ce62012-05-18 14:08:55 -0400569 sense_hdr.sense_key == ILLEGAL_REQUEST &&
570 sense_hdr.asc == 0x24 && sense_hdr.ascq == 0) {
Hannes Reinecke43394c62016-02-19 09:17:04 +0100571 pg->flags |= ALUA_RTPG_EXT_HDR_UNSUPP;
Rob Evers8e67ce62012-05-18 14:08:55 -0400572 goto retry;
573 }
Hannes Reineckee2d817d2015-12-01 10:16:54 +0100574 /*
575 * Retry on ALUA state transition or if any
576 * UNIT ATTENTION occurred.
577 */
578 if (sense_hdr.sense_key == NOT_READY &&
579 sense_hdr.asc == 0x04 && sense_hdr.ascq == 0x0a)
580 err = SCSI_DH_RETRY;
581 else if (sense_hdr.sense_key == UNIT_ATTENTION)
582 err = SCSI_DH_RETRY;
Hannes Reinecke03197b62016-02-19 09:17:10 +0100583 if (err == SCSI_DH_RETRY &&
584 pg->expiry != 0 && time_before(jiffies, pg->expiry)) {
Hannes Reinecke80bd68d2015-12-01 10:16:47 +0100585 sdev_printk(KERN_ERR, sdev, "%s: rtpg retry\n",
586 ALUA_DH_NAME);
587 scsi_print_sense_hdr(sdev, ALUA_DH_NAME, &sense_hdr);
tang.junhui086acff2016-09-18 18:05:11 +0800588 kfree(buff);
Hannes Reinecke03197b62016-02-19 09:17:10 +0100589 return err;
Hannes Reinecke80bd68d2015-12-01 10:16:47 +0100590 }
591 sdev_printk(KERN_ERR, sdev, "%s: rtpg failed\n",
592 ALUA_DH_NAME);
593 scsi_print_sense_hdr(sdev, ALUA_DH_NAME, &sense_hdr);
Hannes Reineckec49c8342016-02-19 09:17:03 +0100594 kfree(buff);
Hannes Reinecke03197b62016-02-19 09:17:10 +0100595 pg->expiry = 0;
Hannes Reinecke80bd68d2015-12-01 10:16:47 +0100596 return SCSI_DH_IO;
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700597 }
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700598
Hannes Reineckec49c8342016-02-19 09:17:03 +0100599 len = get_unaligned_be32(&buff[0]) + 4;
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700600
Hannes Reineckec49c8342016-02-19 09:17:03 +0100601 if (len > bufflen) {
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700602 /* Resubmit with the correct length */
Hannes Reineckec49c8342016-02-19 09:17:03 +0100603 kfree(buff);
604 bufflen = len;
605 buff = kmalloc(bufflen, GFP_KERNEL);
606 if (!buff) {
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700607 sdev_printk(KERN_WARNING, sdev,
Harvey Harrisoncadbd4a2008-07-03 23:47:27 -0700608 "%s: kmalloc buffer failed\n",__func__);
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700609 /* Temporary failure, bypass */
Hannes Reinecke03197b62016-02-19 09:17:10 +0100610 pg->expiry = 0;
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700611 return SCSI_DH_DEV_TEMP_BUSY;
612 }
613 goto retry;
614 }
615
Hannes Reinecke43394c62016-02-19 09:17:04 +0100616 orig_transition_tmo = pg->transition_tmo;
Hannes Reineckec49c8342016-02-19 09:17:03 +0100617 if ((buff[4] & RTPG_FMT_MASK) == RTPG_FMT_EXT_HDR && buff[5] != 0)
Hannes Reinecke43394c62016-02-19 09:17:04 +0100618 pg->transition_tmo = buff[5];
Rob Evers3588c5a2012-05-18 14:08:54 -0400619 else
Hannes Reinecke43394c62016-02-19 09:17:04 +0100620 pg->transition_tmo = ALUA_FAILOVER_TIMEOUT;
Rob Evers3588c5a2012-05-18 14:08:54 -0400621
Hannes Reinecke28261402016-02-19 09:17:07 +0100622 if (orig_transition_tmo != pg->transition_tmo) {
Rob Evers3588c5a2012-05-18 14:08:54 -0400623 sdev_printk(KERN_INFO, sdev,
624 "%s: transition timeout set to %d seconds\n",
Hannes Reinecke43394c62016-02-19 09:17:04 +0100625 ALUA_DH_NAME, pg->transition_tmo);
Hannes Reinecke03197b62016-02-19 09:17:10 +0100626 pg->expiry = jiffies + pg->transition_tmo * HZ;
Rob Evers3588c5a2012-05-18 14:08:54 -0400627 }
628
Hannes Reineckec49c8342016-02-19 09:17:03 +0100629 if ((buff[4] & RTPG_FMT_MASK) == RTPG_FMT_EXT_HDR)
Rob Evers3588c5a2012-05-18 14:08:54 -0400630 tpg_desc_tbl_off = 8;
631 else
632 tpg_desc_tbl_off = 4;
633
Hannes Reineckec57168a2016-02-19 09:17:14 +0100634 for (k = tpg_desc_tbl_off, desc = buff + tpg_desc_tbl_off;
Rob Evers3588c5a2012-05-18 14:08:54 -0400635 k < len;
Hannes Reineckec57168a2016-02-19 09:17:14 +0100636 k += off, desc += off) {
637 u16 group_id = get_unaligned_be16(&desc[2]);
Rob Evers3588c5a2012-05-18 14:08:54 -0400638
Hannes Reineckec57168a2016-02-19 09:17:14 +0100639 spin_lock_irqsave(&port_group_lock, flags);
640 tmp_pg = alua_find_get_pg(pg->device_id_str, pg->device_id_len,
641 group_id);
642 spin_unlock_irqrestore(&port_group_lock, flags);
643 if (tmp_pg) {
644 if (spin_trylock_irqsave(&tmp_pg->lock, flags)) {
645 if ((tmp_pg == pg) ||
646 !(tmp_pg->flags & ALUA_PG_RUNNING)) {
Hannes Reineckecb0a1682016-03-03 07:54:09 +0100647 struct alua_dh_data *h;
648
Hannes Reineckec57168a2016-02-19 09:17:14 +0100649 tmp_pg->state = desc[0] & 0x0f;
650 tmp_pg->pref = desc[0] >> 7;
Hannes Reineckecb0a1682016-03-03 07:54:09 +0100651 rcu_read_lock();
652 list_for_each_entry_rcu(h,
653 &tmp_pg->dh_list, node) {
654 /* h->sdev should always be valid */
655 BUG_ON(!h->sdev);
656 h->sdev->access_state = desc[0];
657 }
658 rcu_read_unlock();
Hannes Reineckec57168a2016-02-19 09:17:14 +0100659 }
660 if (tmp_pg == pg)
661 valid_states = desc[1];
662 spin_unlock_irqrestore(&tmp_pg->lock, flags);
663 }
664 kref_put(&tmp_pg->kref, release_port_group);
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700665 }
Hannes Reineckec57168a2016-02-19 09:17:14 +0100666 off = 8 + (desc[7] * 4);
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700667 }
668
Hannes Reineckec57168a2016-02-19 09:17:14 +0100669 spin_lock_irqsave(&pg->lock, flags);
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700670 sdev_printk(KERN_INFO, sdev,
Moger, Babudcd3a752012-03-27 20:56:08 +0000671 "%s: port group %02x state %c %s supports %c%c%c%c%c%c%c\n",
Hannes Reinecke43394c62016-02-19 09:17:04 +0100672 ALUA_DH_NAME, pg->group_id, print_alua_state(pg->state),
673 pg->pref ? "preferred" : "non-preferred",
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700674 valid_states&TPGS_SUPPORT_TRANSITION?'T':'t',
675 valid_states&TPGS_SUPPORT_OFFLINE?'O':'o',
Hannes Reinecke69723d12010-09-24 15:57:04 +0200676 valid_states&TPGS_SUPPORT_LBA_DEPENDENT?'L':'l',
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700677 valid_states&TPGS_SUPPORT_UNAVAILABLE?'U':'u',
678 valid_states&TPGS_SUPPORT_STANDBY?'S':'s',
679 valid_states&TPGS_SUPPORT_NONOPTIMIZED?'N':'n',
680 valid_states&TPGS_SUPPORT_OPTIMIZED?'A':'a');
681
Hannes Reinecke43394c62016-02-19 09:17:04 +0100682 switch (pg->state) {
Hannes Reinecke5115fc72016-03-03 07:54:08 +0100683 case SCSI_ACCESS_STATE_TRANSITIONING:
Hannes Reinecke03197b62016-02-19 09:17:10 +0100684 if (time_before(jiffies, pg->expiry)) {
Hannes Reinecke28261402016-02-19 09:17:07 +0100685 /* State transition, retry */
Hannes Reinecke03197b62016-02-19 09:17:10 +0100686 pg->interval = 2;
687 err = SCSI_DH_RETRY;
688 } else {
Hannes Reineckecb0a1682016-03-03 07:54:09 +0100689 struct alua_dh_data *h;
690
Hannes Reinecke03197b62016-02-19 09:17:10 +0100691 /* Transitioning time exceeded, set port to standby */
692 err = SCSI_DH_IO;
Hannes Reinecke5115fc72016-03-03 07:54:08 +0100693 pg->state = SCSI_ACCESS_STATE_STANDBY;
Hannes Reinecke03197b62016-02-19 09:17:10 +0100694 pg->expiry = 0;
Hannes Reineckecb0a1682016-03-03 07:54:09 +0100695 rcu_read_lock();
696 list_for_each_entry_rcu(h, &pg->dh_list, node) {
697 BUG_ON(!h->sdev);
698 h->sdev->access_state =
699 (pg->state & SCSI_ACCESS_STATE_MASK);
700 if (pg->pref)
701 h->sdev->access_state |=
702 SCSI_ACCESS_STATE_PREFERRED;
703 }
704 rcu_read_unlock();
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700705 }
Hannes Reinecke69723d12010-09-24 15:57:04 +0200706 break;
Hannes Reinecke5115fc72016-03-03 07:54:08 +0100707 case SCSI_ACCESS_STATE_OFFLINE:
Bart Van Asschee47f8972012-08-24 09:08:41 +0000708 /* Path unusable */
Hannes Reinecke69723d12010-09-24 15:57:04 +0200709 err = SCSI_DH_DEV_OFFLINED;
Hannes Reinecke03197b62016-02-19 09:17:10 +0100710 pg->expiry = 0;
Hannes Reinecke69723d12010-09-24 15:57:04 +0200711 break;
712 default:
713 /* Useable path if active */
714 err = SCSI_DH_OK;
Hannes Reinecke03197b62016-02-19 09:17:10 +0100715 pg->expiry = 0;
Hannes Reinecke69723d12010-09-24 15:57:04 +0200716 break;
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700717 }
Hannes Reineckec57168a2016-02-19 09:17:14 +0100718 spin_unlock_irqrestore(&pg->lock, flags);
Hannes Reineckec49c8342016-02-19 09:17:03 +0100719 kfree(buff);
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700720 return err;
721}
722
723/*
Hannes Reineckef2ecf132016-02-19 09:16:59 +0100724 * alua_stpg - Issue a SET TARGET PORT GROUP command
725 *
726 * Issue a SET TARGET PORT GROUP command and evaluate the
Hannes Reineckeb2460752016-02-19 09:17:00 +0100727 * response. Returns SCSI_DH_RETRY per default to trigger
728 * a re-evaluation of the target group state or SCSI_DH_OK
729 * if no further action needs to be taken.
Hannes Reineckef2ecf132016-02-19 09:16:59 +0100730 */
Hannes Reinecke43394c62016-02-19 09:17:04 +0100731static unsigned alua_stpg(struct scsi_device *sdev, struct alua_port_group *pg)
Hannes Reineckef2ecf132016-02-19 09:16:59 +0100732{
Hannes Reineckeb2460752016-02-19 09:17:00 +0100733 int retval;
734 struct scsi_sense_hdr sense_hdr;
Hannes Reineckef2ecf132016-02-19 09:16:59 +0100735
Hannes Reinecke43394c62016-02-19 09:17:04 +0100736 if (!(pg->tpgs & TPGS_MODE_EXPLICIT)) {
Hannes Reineckeb2460752016-02-19 09:17:00 +0100737 /* Only implicit ALUA supported, retry */
738 return SCSI_DH_RETRY;
739 }
Hannes Reinecke43394c62016-02-19 09:17:04 +0100740 switch (pg->state) {
Hannes Reinecke5115fc72016-03-03 07:54:08 +0100741 case SCSI_ACCESS_STATE_OPTIMAL:
Hannes Reineckeb2460752016-02-19 09:17:00 +0100742 return SCSI_DH_OK;
Hannes Reinecke5115fc72016-03-03 07:54:08 +0100743 case SCSI_ACCESS_STATE_ACTIVE:
Hannes Reinecke43394c62016-02-19 09:17:04 +0100744 if ((pg->flags & ALUA_OPTIMIZE_STPG) &&
745 !pg->pref &&
746 (pg->tpgs & TPGS_MODE_IMPLICIT))
Hannes Reineckeb2460752016-02-19 09:17:00 +0100747 return SCSI_DH_OK;
Hannes Reineckef2ecf132016-02-19 09:16:59 +0100748 break;
Hannes Reinecke5115fc72016-03-03 07:54:08 +0100749 case SCSI_ACCESS_STATE_STANDBY:
750 case SCSI_ACCESS_STATE_UNAVAILABLE:
Hannes Reineckef2ecf132016-02-19 09:16:59 +0100751 break;
Hannes Reinecke5115fc72016-03-03 07:54:08 +0100752 case SCSI_ACCESS_STATE_OFFLINE:
Hannes Reineckeb2460752016-02-19 09:17:00 +0100753 return SCSI_DH_IO;
Hannes Reinecke5115fc72016-03-03 07:54:08 +0100754 case SCSI_ACCESS_STATE_TRANSITIONING:
Hannes Reineckef2ecf132016-02-19 09:16:59 +0100755 break;
756 default:
Hannes Reineckeb2460752016-02-19 09:17:00 +0100757 sdev_printk(KERN_INFO, sdev,
758 "%s: stpg failed, unhandled TPGS state %d",
Hannes Reinecke43394c62016-02-19 09:17:04 +0100759 ALUA_DH_NAME, pg->state);
Hannes Reineckeb2460752016-02-19 09:17:00 +0100760 return SCSI_DH_NOSYS;
Hannes Reineckef2ecf132016-02-19 09:16:59 +0100761 }
Hannes Reinecke43394c62016-02-19 09:17:04 +0100762 retval = submit_stpg(sdev, pg->group_id, &sense_hdr);
Hannes Reineckef2ecf132016-02-19 09:16:59 +0100763
Hannes Reineckeb2460752016-02-19 09:17:00 +0100764 if (retval) {
Hannes Reinecke40bb61a2016-02-19 09:17:02 +0100765 if (!scsi_sense_valid(&sense_hdr)) {
Hannes Reineckeb2460752016-02-19 09:17:00 +0100766 sdev_printk(KERN_INFO, sdev,
767 "%s: stpg failed, result %d",
768 ALUA_DH_NAME, retval);
Hannes Reinecke40bb61a2016-02-19 09:17:02 +0100769 if (driver_byte(retval) == DRIVER_ERROR)
Hannes Reineckeb2460752016-02-19 09:17:00 +0100770 return SCSI_DH_DEV_TEMP_BUSY;
771 } else {
Hannes Reinecke43394c62016-02-19 09:17:04 +0100772 sdev_printk(KERN_INFO, sdev, "%s: stpg failed\n",
Hannes Reineckeb2460752016-02-19 09:17:00 +0100773 ALUA_DH_NAME);
774 scsi_print_sense_hdr(sdev, ALUA_DH_NAME, &sense_hdr);
775 }
Hannes Reineckef2ecf132016-02-19 09:16:59 +0100776 }
Hannes Reineckeb2460752016-02-19 09:17:00 +0100777 /* Retry RTPG */
778 return SCSI_DH_RETRY;
Hannes Reineckef2ecf132016-02-19 09:16:59 +0100779}
780
Hannes Reinecke03197b62016-02-19 09:17:10 +0100781static void alua_rtpg_work(struct work_struct *work)
782{
783 struct alua_port_group *pg =
784 container_of(work, struct alua_port_group, rtpg_work.work);
785 struct scsi_device *sdev;
786 LIST_HEAD(qdata_list);
787 int err = SCSI_DH_OK;
788 struct alua_queue_data *qdata, *tmp;
789 unsigned long flags;
Hannes Reinecke00642a12016-02-19 09:17:11 +0100790 struct workqueue_struct *alua_wq = kaluad_wq;
Hannes Reinecke03197b62016-02-19 09:17:10 +0100791
792 spin_lock_irqsave(&pg->lock, flags);
793 sdev = pg->rtpg_sdev;
794 if (!sdev) {
795 WARN_ON(pg->flags & ALUA_PG_RUN_RTPG);
796 WARN_ON(pg->flags & ALUA_PG_RUN_STPG);
797 spin_unlock_irqrestore(&pg->lock, flags);
798 return;
799 }
Hannes Reinecke00642a12016-02-19 09:17:11 +0100800 if (pg->flags & ALUA_SYNC_STPG)
801 alua_wq = kaluad_sync_wq;
Hannes Reinecke03197b62016-02-19 09:17:10 +0100802 pg->flags |= ALUA_PG_RUNNING;
803 if (pg->flags & ALUA_PG_RUN_RTPG) {
Hannes Reinecke9d2c3032016-02-19 09:17:15 +0100804 int state = pg->state;
805
Hannes Reinecke03197b62016-02-19 09:17:10 +0100806 pg->flags &= ~ALUA_PG_RUN_RTPG;
807 spin_unlock_irqrestore(&pg->lock, flags);
Hannes Reinecke5115fc72016-03-03 07:54:08 +0100808 if (state == SCSI_ACCESS_STATE_TRANSITIONING) {
Hannes Reinecke9d2c3032016-02-19 09:17:15 +0100809 if (alua_tur(sdev) == SCSI_DH_RETRY) {
810 spin_lock_irqsave(&pg->lock, flags);
811 pg->flags &= ~ALUA_PG_RUNNING;
812 pg->flags |= ALUA_PG_RUN_RTPG;
813 spin_unlock_irqrestore(&pg->lock, flags);
814 queue_delayed_work(alua_wq, &pg->rtpg_work,
815 pg->interval * HZ);
816 return;
817 }
818 /* Send RTPG on failure or if TUR indicates SUCCESS */
819 }
Hannes Reinecke03197b62016-02-19 09:17:10 +0100820 err = alua_rtpg(sdev, pg);
821 spin_lock_irqsave(&pg->lock, flags);
Hannes Reinecke2b358652016-02-19 09:17:13 +0100822 if (err == SCSI_DH_RETRY || pg->flags & ALUA_PG_RUN_RTPG) {
Hannes Reinecke03197b62016-02-19 09:17:10 +0100823 pg->flags &= ~ALUA_PG_RUNNING;
824 pg->flags |= ALUA_PG_RUN_RTPG;
825 spin_unlock_irqrestore(&pg->lock, flags);
Hannes Reinecke00642a12016-02-19 09:17:11 +0100826 queue_delayed_work(alua_wq, &pg->rtpg_work,
Hannes Reinecke03197b62016-02-19 09:17:10 +0100827 pg->interval * HZ);
828 return;
829 }
830 if (err != SCSI_DH_OK)
831 pg->flags &= ~ALUA_PG_RUN_STPG;
832 }
833 if (pg->flags & ALUA_PG_RUN_STPG) {
834 pg->flags &= ~ALUA_PG_RUN_STPG;
835 spin_unlock_irqrestore(&pg->lock, flags);
836 err = alua_stpg(sdev, pg);
837 spin_lock_irqsave(&pg->lock, flags);
Hannes Reinecke2b358652016-02-19 09:17:13 +0100838 if (err == SCSI_DH_RETRY || pg->flags & ALUA_PG_RUN_RTPG) {
Hannes Reinecke03197b62016-02-19 09:17:10 +0100839 pg->flags |= ALUA_PG_RUN_RTPG;
840 pg->interval = 0;
841 pg->flags &= ~ALUA_PG_RUNNING;
842 spin_unlock_irqrestore(&pg->lock, flags);
Hannes Reinecke00642a12016-02-19 09:17:11 +0100843 queue_delayed_work(alua_wq, &pg->rtpg_work,
Hannes Reinecke03197b62016-02-19 09:17:10 +0100844 pg->interval * HZ);
845 return;
846 }
847 }
848
849 list_splice_init(&pg->rtpg_list, &qdata_list);
850 pg->rtpg_sdev = NULL;
851 spin_unlock_irqrestore(&pg->lock, flags);
852
853 list_for_each_entry_safe(qdata, tmp, &qdata_list, entry) {
854 list_del(&qdata->entry);
855 if (qdata->callback_fn)
856 qdata->callback_fn(qdata->callback_data, err);
857 kfree(qdata);
858 }
859 spin_lock_irqsave(&pg->lock, flags);
860 pg->flags &= ~ALUA_PG_RUNNING;
861 spin_unlock_irqrestore(&pg->lock, flags);
862 scsi_device_put(sdev);
863 kref_put(&pg->kref, release_port_group);
864}
865
866static void alua_rtpg_queue(struct alua_port_group *pg,
867 struct scsi_device *sdev,
Hannes Reinecke2b358652016-02-19 09:17:13 +0100868 struct alua_queue_data *qdata, bool force)
Hannes Reinecke03197b62016-02-19 09:17:10 +0100869{
870 int start_queue = 0;
871 unsigned long flags;
Hannes Reinecke00642a12016-02-19 09:17:11 +0100872 struct workqueue_struct *alua_wq = kaluad_wq;
Hannes Reinecke03197b62016-02-19 09:17:10 +0100873
874 if (!pg)
875 return;
876
877 spin_lock_irqsave(&pg->lock, flags);
878 if (qdata) {
879 list_add_tail(&qdata->entry, &pg->rtpg_list);
880 pg->flags |= ALUA_PG_RUN_STPG;
Hannes Reinecke2b358652016-02-19 09:17:13 +0100881 force = true;
Hannes Reinecke03197b62016-02-19 09:17:10 +0100882 }
883 if (pg->rtpg_sdev == NULL) {
884 pg->interval = 0;
885 pg->flags |= ALUA_PG_RUN_RTPG;
886 kref_get(&pg->kref);
887 pg->rtpg_sdev = sdev;
888 scsi_device_get(sdev);
889 start_queue = 1;
Hannes Reinecke2b358652016-02-19 09:17:13 +0100890 } else if (!(pg->flags & ALUA_PG_RUN_RTPG) && force) {
891 pg->flags |= ALUA_PG_RUN_RTPG;
892 /* Do not queue if the worker is already running */
893 if (!(pg->flags & ALUA_PG_RUNNING)) {
894 kref_get(&pg->kref);
895 start_queue = 1;
896 }
Hannes Reinecke03197b62016-02-19 09:17:10 +0100897 }
Hannes Reinecke2b358652016-02-19 09:17:13 +0100898
Hannes Reinecke00642a12016-02-19 09:17:11 +0100899 if (pg->flags & ALUA_SYNC_STPG)
900 alua_wq = kaluad_sync_wq;
Hannes Reinecke03197b62016-02-19 09:17:10 +0100901 spin_unlock_irqrestore(&pg->lock, flags);
902
903 if (start_queue &&
Hannes Reinecke00642a12016-02-19 09:17:11 +0100904 !queue_delayed_work(alua_wq, &pg->rtpg_work,
Hannes Reinecke03197b62016-02-19 09:17:10 +0100905 msecs_to_jiffies(ALUA_RTPG_DELAY_MSECS))) {
906 scsi_device_put(sdev);
907 kref_put(&pg->kref, release_port_group);
908 }
909}
910
Hannes Reineckef2ecf132016-02-19 09:16:59 +0100911/*
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700912 * alua_initialize - Initialize ALUA state
913 * @sdev: the device to be initialized
914 *
915 * For the prep_fn to work correctly we have
916 * to initialize the ALUA state for the device.
917 */
918static int alua_initialize(struct scsi_device *sdev, struct alua_dh_data *h)
919{
Hannes Reinecke43394c62016-02-19 09:17:04 +0100920 int err = SCSI_DH_DEV_UNSUPP, tpgs;
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700921
Hannes Reinecke03197b62016-02-19 09:17:10 +0100922 mutex_lock(&h->init_mutex);
Hannes Reinecke43394c62016-02-19 09:17:04 +0100923 tpgs = alua_check_tpgs(sdev);
Hannes Reineckea4253fd2016-02-19 09:17:06 +0100924 if (tpgs != TPGS_MODE_NONE)
925 err = alua_check_vpd(sdev, h, tpgs);
Hannes Reinecke03197b62016-02-19 09:17:10 +0100926 h->init_error = err;
927 mutex_unlock(&h->init_mutex);
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700928 return err;
929}
Moger, Babu4335d092012-03-27 20:55:49 +0000930/*
931 * alua_set_params - set/unset the optimize flag
932 * @sdev: device on the path to be activated
933 * params - parameters in the following format
934 * "no_of_params\0param1\0param2\0param3\0...\0"
935 * For example, to set the flag pass the following parameters
936 * from multipath.conf
937 * hardware_handler "2 alua 1"
938 */
939static int alua_set_params(struct scsi_device *sdev, const char *params)
940{
Christoph Hellwigee14c672015-08-27 14:16:59 +0200941 struct alua_dh_data *h = sdev->handler_data;
Hannes Reinecke03197b62016-02-19 09:17:10 +0100942 struct alua_port_group __rcu *pg = NULL;
Moger, Babu4335d092012-03-27 20:55:49 +0000943 unsigned int optimize = 0, argc;
944 const char *p = params;
945 int result = SCSI_DH_OK;
Hannes Reinecke03197b62016-02-19 09:17:10 +0100946 unsigned long flags;
Moger, Babu4335d092012-03-27 20:55:49 +0000947
948 if ((sscanf(params, "%u", &argc) != 1) || (argc != 1))
949 return -EINVAL;
950
951 while (*p++)
952 ;
953 if ((sscanf(p, "%u", &optimize) != 1) || (optimize > 1))
954 return -EINVAL;
955
Hannes Reinecke03197b62016-02-19 09:17:10 +0100956 rcu_read_lock();
957 pg = rcu_dereference(h->pg);
958 if (!pg) {
959 rcu_read_unlock();
Hannes Reinecke43394c62016-02-19 09:17:04 +0100960 return -ENXIO;
Hannes Reinecke03197b62016-02-19 09:17:10 +0100961 }
962 spin_lock_irqsave(&pg->lock, flags);
Moger, Babu4335d092012-03-27 20:55:49 +0000963 if (optimize)
Hannes Reinecke43394c62016-02-19 09:17:04 +0100964 pg->flags |= ALUA_OPTIMIZE_STPG;
Moger, Babu4335d092012-03-27 20:55:49 +0000965 else
Hannes Reinecke43394c62016-02-19 09:17:04 +0100966 pg->flags &= ~ALUA_OPTIMIZE_STPG;
Hannes Reinecke03197b62016-02-19 09:17:10 +0100967 spin_unlock_irqrestore(&pg->lock, flags);
968 rcu_read_unlock();
Moger, Babu4335d092012-03-27 20:55:49 +0000969
970 return result;
971}
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700972
973/*
974 * alua_activate - activate a path
975 * @sdev: device on the path to be activated
976 *
977 * We're currently switching the port group to be activated only and
978 * let the array figure out the rest.
979 * There may be other arrays which require us to switch all port groups
980 * based on a certain policy. But until we actually encounter them it
981 * should be okay.
982 */
Chandra Seetharaman3ae31f62009-10-21 09:22:46 -0700983static int alua_activate(struct scsi_device *sdev,
984 activate_complete fn, void *data)
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700985{
Christoph Hellwigee14c672015-08-27 14:16:59 +0200986 struct alua_dh_data *h = sdev->handler_data;
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700987 int err = SCSI_DH_OK;
Hannes Reinecke03197b62016-02-19 09:17:10 +0100988 struct alua_queue_data *qdata;
989 struct alua_port_group __rcu *pg;
Hannes Reinecke057ea7c2008-07-17 16:53:21 -0700990
Hannes Reinecke03197b62016-02-19 09:17:10 +0100991 qdata = kzalloc(sizeof(*qdata), GFP_KERNEL);
992 if (!qdata) {
993 err = SCSI_DH_RES_TEMP_UNAVAIL;
Hannes Reinecke43394c62016-02-19 09:17:04 +0100994 goto out;
995 }
Hannes Reinecke03197b62016-02-19 09:17:10 +0100996 qdata->callback_fn = fn;
997 qdata->callback_data = data;
998
999 mutex_lock(&h->init_mutex);
1000 rcu_read_lock();
1001 pg = rcu_dereference(h->pg);
1002 if (!pg || !kref_get_unless_zero(&pg->kref)) {
1003 rcu_read_unlock();
1004 kfree(qdata);
1005 err = h->init_error;
1006 mutex_unlock(&h->init_mutex);
1007 goto out;
1008 }
1009 fn = NULL;
1010 rcu_read_unlock();
1011 mutex_unlock(&h->init_mutex);
1012
Hannes Reinecke2b358652016-02-19 09:17:13 +01001013 alua_rtpg_queue(pg, sdev, qdata, true);
Hannes Reinecke03197b62016-02-19 09:17:10 +01001014 kref_put(&pg->kref, release_port_group);
Hannes Reinecke057ea7c2008-07-17 16:53:21 -07001015out:
Hannes Reineckeb2460752016-02-19 09:17:00 +01001016 if (fn)
Chandra Seetharaman3ae31f62009-10-21 09:22:46 -07001017 fn(data, err);
1018 return 0;
Hannes Reinecke057ea7c2008-07-17 16:53:21 -07001019}
1020
1021/*
Hannes Reinecke2b358652016-02-19 09:17:13 +01001022 * alua_check - check path status
1023 * @sdev: device on the path to be checked
1024 *
1025 * Check the device status
1026 */
1027static void alua_check(struct scsi_device *sdev, bool force)
1028{
1029 struct alua_dh_data *h = sdev->handler_data;
1030 struct alua_port_group *pg;
1031
1032 rcu_read_lock();
1033 pg = rcu_dereference(h->pg);
1034 if (!pg || !kref_get_unless_zero(&pg->kref)) {
1035 rcu_read_unlock();
1036 return;
1037 }
1038 rcu_read_unlock();
1039
1040 alua_rtpg_queue(pg, sdev, NULL, force);
1041 kref_put(&pg->kref, release_port_group);
1042}
1043
1044/*
Hannes Reinecke057ea7c2008-07-17 16:53:21 -07001045 * alua_prep_fn - request callback
1046 *
1047 * Fail I/O to all paths not in state
1048 * active/optimized or active/non-optimized.
1049 */
1050static int alua_prep_fn(struct scsi_device *sdev, struct request *req)
1051{
Christoph Hellwigee14c672015-08-27 14:16:59 +02001052 struct alua_dh_data *h = sdev->handler_data;
Hannes Reinecke03197b62016-02-19 09:17:10 +01001053 struct alua_port_group __rcu *pg;
Hannes Reinecke5115fc72016-03-03 07:54:08 +01001054 unsigned char state = SCSI_ACCESS_STATE_OPTIMAL;
Hannes Reinecke057ea7c2008-07-17 16:53:21 -07001055 int ret = BLKPREP_OK;
1056
Hannes Reinecke03197b62016-02-19 09:17:10 +01001057 rcu_read_lock();
1058 pg = rcu_dereference(h->pg);
1059 if (pg)
1060 state = pg->state;
1061 rcu_read_unlock();
Hannes Reinecke5115fc72016-03-03 07:54:08 +01001062 if (state == SCSI_ACCESS_STATE_TRANSITIONING)
Hannes Reinecke69723d12010-09-24 15:57:04 +02001063 ret = BLKPREP_DEFER;
Hannes Reinecke5115fc72016-03-03 07:54:08 +01001064 else if (state != SCSI_ACCESS_STATE_OPTIMAL &&
1065 state != SCSI_ACCESS_STATE_ACTIVE &&
1066 state != SCSI_ACCESS_STATE_LBA) {
Hannes Reinecke057ea7c2008-07-17 16:53:21 -07001067 ret = BLKPREP_KILL;
Christoph Hellwige8064022016-10-20 15:12:13 +02001068 req->rq_flags |= RQF_QUIET;
Hannes Reinecke057ea7c2008-07-17 16:53:21 -07001069 }
1070 return ret;
1071
1072}
1073
Hannes Reinecked3d32892016-02-19 09:17:16 +01001074static void alua_rescan(struct scsi_device *sdev)
1075{
1076 struct alua_dh_data *h = sdev->handler_data;
1077
1078 alua_initialize(sdev, h);
1079}
1080
Christoph Hellwig1d520322014-09-14 11:08:21 -07001081/*
1082 * alua_bus_attach - Attach device handler
1083 * @sdev: device to be attached to
1084 */
Christoph Hellwigee14c672015-08-27 14:16:59 +02001085static int alua_bus_attach(struct scsi_device *sdev)
Christoph Hellwig1d520322014-09-14 11:08:21 -07001086{
1087 struct alua_dh_data *h;
Hannes Reinecke43394c62016-02-19 09:17:04 +01001088 int err, ret = -EINVAL;
Christoph Hellwig1d520322014-09-14 11:08:21 -07001089
1090 h = kzalloc(sizeof(*h) , GFP_KERNEL);
1091 if (!h)
Christoph Hellwigee14c672015-08-27 14:16:59 +02001092 return -ENOMEM;
Hannes Reinecke03197b62016-02-19 09:17:10 +01001093 spin_lock_init(&h->pg_lock);
1094 rcu_assign_pointer(h->pg, NULL);
1095 h->init_error = SCSI_DH_OK;
Christoph Hellwig1d520322014-09-14 11:08:21 -07001096 h->sdev = sdev;
Hannes Reineckecb0a1682016-03-03 07:54:09 +01001097 INIT_LIST_HEAD(&h->node);
Christoph Hellwig1d520322014-09-14 11:08:21 -07001098
Hannes Reinecke03197b62016-02-19 09:17:10 +01001099 mutex_init(&h->init_mutex);
Christoph Hellwig1d520322014-09-14 11:08:21 -07001100 err = alua_initialize(sdev, h);
Hannes Reinecke43394c62016-02-19 09:17:04 +01001101 if (err == SCSI_DH_NOMEM)
1102 ret = -ENOMEM;
Christoph Hellwig1d520322014-09-14 11:08:21 -07001103 if (err != SCSI_DH_OK && err != SCSI_DH_DEV_OFFLINED)
1104 goto failed;
1105
Christoph Hellwigee14c672015-08-27 14:16:59 +02001106 sdev->handler_data = h;
1107 return 0;
Christoph Hellwig1d520322014-09-14 11:08:21 -07001108failed:
1109 kfree(h);
Hannes Reinecke43394c62016-02-19 09:17:04 +01001110 return ret;
Christoph Hellwig1d520322014-09-14 11:08:21 -07001111}
1112
1113/*
1114 * alua_bus_detach - Detach device handler
1115 * @sdev: device to be detached from
1116 */
1117static void alua_bus_detach(struct scsi_device *sdev)
1118{
Christoph Hellwigee14c672015-08-27 14:16:59 +02001119 struct alua_dh_data *h = sdev->handler_data;
Hannes Reinecke03197b62016-02-19 09:17:10 +01001120 struct alua_port_group *pg;
Christoph Hellwig1d520322014-09-14 11:08:21 -07001121
Hannes Reinecke03197b62016-02-19 09:17:10 +01001122 spin_lock(&h->pg_lock);
1123 pg = h->pg;
1124 rcu_assign_pointer(h->pg, NULL);
1125 h->sdev = NULL;
1126 spin_unlock(&h->pg_lock);
Hannes Reineckecb0a1682016-03-03 07:54:09 +01001127 if (pg) {
Bart Van Assche38c31592016-03-28 11:14:04 -07001128 spin_lock_irq(&pg->lock);
Hannes Reineckecb0a1682016-03-03 07:54:09 +01001129 list_del_rcu(&h->node);
Bart Van Assche38c31592016-03-28 11:14:04 -07001130 spin_unlock_irq(&pg->lock);
Hannes Reinecke03197b62016-02-19 09:17:10 +01001131 kref_put(&pg->kref, release_port_group);
Hannes Reineckecb0a1682016-03-03 07:54:09 +01001132 }
Christoph Hellwigee14c672015-08-27 14:16:59 +02001133 sdev->handler_data = NULL;
Christoph Hellwig1d520322014-09-14 11:08:21 -07001134 kfree(h);
1135}
Hannes Reinecke057ea7c2008-07-17 16:53:21 -07001136
1137static struct scsi_device_handler alua_dh = {
1138 .name = ALUA_DH_NAME,
1139 .module = THIS_MODULE,
Hannes Reinecke057ea7c2008-07-17 16:53:21 -07001140 .attach = alua_bus_attach,
1141 .detach = alua_bus_detach,
1142 .prep_fn = alua_prep_fn,
1143 .check_sense = alua_check_sense,
1144 .activate = alua_activate,
Hannes Reinecked3d32892016-02-19 09:17:16 +01001145 .rescan = alua_rescan,
Moger, Babu4335d092012-03-27 20:55:49 +00001146 .set_params = alua_set_params,
Hannes Reinecke057ea7c2008-07-17 16:53:21 -07001147};
1148
Hannes Reinecke057ea7c2008-07-17 16:53:21 -07001149static int __init alua_init(void)
1150{
1151 int r;
1152
Hannes Reinecke03197b62016-02-19 09:17:10 +01001153 kaluad_wq = alloc_workqueue("kaluad", WQ_MEM_RECLAIM, 0);
1154 if (!kaluad_wq) {
1155 /* Temporary failure, bypass */
1156 return SCSI_DH_DEV_TEMP_BUSY;
1157 }
Hannes Reinecke00642a12016-02-19 09:17:11 +01001158 kaluad_sync_wq = create_workqueue("kaluad_sync");
1159 if (!kaluad_sync_wq) {
1160 destroy_workqueue(kaluad_wq);
1161 return SCSI_DH_DEV_TEMP_BUSY;
1162 }
Hannes Reinecke057ea7c2008-07-17 16:53:21 -07001163 r = scsi_register_device_handler(&alua_dh);
Hannes Reinecke03197b62016-02-19 09:17:10 +01001164 if (r != 0) {
Hannes Reinecke057ea7c2008-07-17 16:53:21 -07001165 printk(KERN_ERR "%s: Failed to register scsi device handler",
1166 ALUA_DH_NAME);
Hannes Reinecke00642a12016-02-19 09:17:11 +01001167 destroy_workqueue(kaluad_sync_wq);
Hannes Reinecke03197b62016-02-19 09:17:10 +01001168 destroy_workqueue(kaluad_wq);
1169 }
Hannes Reinecke057ea7c2008-07-17 16:53:21 -07001170 return r;
1171}
1172
1173static void __exit alua_exit(void)
1174{
1175 scsi_unregister_device_handler(&alua_dh);
Hannes Reinecke00642a12016-02-19 09:17:11 +01001176 destroy_workqueue(kaluad_sync_wq);
Hannes Reinecke03197b62016-02-19 09:17:10 +01001177 destroy_workqueue(kaluad_wq);
Hannes Reinecke057ea7c2008-07-17 16:53:21 -07001178}
1179
1180module_init(alua_init);
1181module_exit(alua_exit);
1182
1183MODULE_DESCRIPTION("DM Multipath ALUA support");
1184MODULE_AUTHOR("Hannes Reinecke <hare@suse.de>");
1185MODULE_LICENSE("GPL");
1186MODULE_VERSION(ALUA_DH_VER);