1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
|
/*
* Basic HP/COMPAQ MSA 1000 support. This is only needed if your HW cannot be
* upgraded.
*
* Copyright (C) 2006 Red Hat, Inc. All rights reserved.
* Copyright (C) 2006 Mike Christie
* Copyright (C) 2008 Hannes Reinecke <hare@suse.de>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; see the file COPYING. If not, write to
* the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/slab.h>
#include <linux/module.h>
#include <scsi/scsi.h>
#include <scsi/scsi_dbg.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_dh.h>
#define HP_SW_NAME "hp_sw"
#define HP_SW_TIMEOUT (60 * HZ)
#define HP_SW_RETRIES 3
#define HP_SW_PATH_UNINITIALIZED -1
#define HP_SW_PATH_ACTIVE 0
#define HP_SW_PATH_PASSIVE 1
struct hp_sw_dh_data {
int path_state;
int retries;
int retry_cnt;
struct scsi_device *sdev;
};
static int hp_sw_start_stop(struct hp_sw_dh_data *);
/*
* tur_done - Handle TEST UNIT READY return status
* @sdev: sdev the command has been sent to
* @errors: blk error code
*
* Returns SCSI_DH_DEV_OFFLINED if the sdev is on the passive path
*/
static int tur_done(struct scsi_device *sdev, struct hp_sw_dh_data *h,
struct scsi_sense_hdr *sshdr)
{
int ret = SCSI_DH_IO;
switch (sshdr->sense_key) {
case UNIT_ATTENTION:
ret = SCSI_DH_IMM_RETRY;
break;
case NOT_READY:
if (sshdr->asc == 0x04 && sshdr->ascq == 2) {
/*
* LUN not ready - Initialization command required
*
* This is the passive path
*/
h->path_state = HP_SW_PATH_PASSIVE;
ret = SCSI_DH_OK;
break;
}
/* Fallthrough */
default:
sdev_printk(KERN_WARNING, sdev,
"%s: sending tur failed, sense %x/%x/%x\n",
HP_SW_NAME, sshdr->sense_key, sshdr->asc,
sshdr->ascq);
break;
}
return ret;
}
/*
* hp_sw_tur - Send TEST UNIT READY
* @sdev: sdev command should be sent to
*
* Use the TEST UNIT READY command to determine
* the path state.
*/
static int hp_sw_tur(struct scsi_device *sdev, struct hp_sw_dh_data *h)
{
unsigned char cmd[6] = { TEST_UNIT_READY };
struct scsi_sense_hdr sshdr;
int ret = SCSI_DH_OK, res;
u64 req_flags = REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT |
REQ_FAILFAST_DRIVER;
retry:
res = scsi_execute(sdev, cmd, DMA_NONE, NULL, 0, NULL, &sshdr,
HP_SW_TIMEOUT, HP_SW_RETRIES, req_flags, 0, NULL);
if (res) {
if (scsi_sense_valid(&sshdr))
ret = tur_done(sdev, h, &sshdr);
else {
sdev_printk(KERN_WARNING, sdev,
"%s: sending tur failed with %x\n",
HP_SW_NAME, res);
ret = SCSI_DH_IO;
}
} else {
h->path_state = HP_SW_PATH_ACTIVE;
ret = SCSI_DH_OK;
}
if (ret == SCSI_DH_IMM_RETRY)
goto retry;
return ret;
}
/*
* hp_sw_start_stop - Send START STOP UNIT command
* @sdev: sdev command should be sent to
*
* Sending START STOP UNIT activates the SP.
*/
static int hp_sw_start_stop(struct hp_sw_dh_data *h)
{
unsigned char cmd[6] = { START_STOP, 0, 0, 0, 1, 0 };
struct scsi_sense_hdr sshdr;
struct scsi_device *sdev = h->sdev;
int res, rc = SCSI_DH_OK;
int retry_cnt = HP_SW_RETRIES;
u64 req_flags = REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT |
REQ_FAILFAST_DRIVER;
retry:
res = scsi_execute(sdev, cmd, DMA_NONE, NULL, 0, NULL, &sshdr,
HP_SW_TIMEOUT, HP_SW_RETRIES, req_flags, 0, NULL);
if (res) {
if (!scsi_sense_valid(&sshdr)) {
sdev_printk(KERN_WARNING, sdev,
"%s: sending start_stop_unit failed, "
"no sense available\n", HP_SW_NAME);
return SCSI_DH_IO;
}
switch (sshdr.sense_key) {
case NOT_READY:
if (sshdr.asc == 0x04 && sshdr.ascq == 3) {
/*
* LUN not ready - manual intervention required
*
* Switch-over in progress, retry.
*/
if (--retry_cnt)
goto retry;
rc = SCSI_DH_RETRY;
break;
}
/* fall through */
default:
sdev_printk(KERN_WARNING, sdev,
"%s: sending start_stop_unit failed, "
"sense %x/%x/%x\n", HP_SW_NAME,
sshdr.sense_key, sshdr.asc, sshdr.ascq);
rc = SCSI_DH_IO;
}
}
return rc;
}
static int hp_sw_prep_fn(struct scsi_device *sdev, struct request *req)
{
struct hp_sw_dh_data *h = sdev->handler_data;
int ret = BLKPREP_OK;
if (h->path_state != HP_SW_PATH_ACTIVE) {
ret = BLKPREP_KILL;
req->rq_flags |= RQF_QUIET;
}
return ret;
}
/*
* hp_sw_activate - Activate a path
* @sdev: sdev on the path to be activated
*
* The HP Active/Passive firmware is pretty simple;
* the passive path reports NOT READY with sense codes
* 0x04/0x02; a START STOP UNIT command will then
* activate the passive path (and deactivate the
* previously active one).
*/
static int hp_sw_activate(struct scsi_device *sdev,
activate_complete fn, void *data)
{
int ret = SCSI_DH_OK;
struct hp_sw_dh_data *h = sdev->handler_data;
ret = hp_sw_tur(sdev, h);
if (ret == SCSI_DH_OK && h->path_state == HP_SW_PATH_PASSIVE)
ret = hp_sw_start_stop(h);
if (fn)
fn(data, ret);
return 0;
}
static int hp_sw_bus_attach(struct scsi_device *sdev)
{
struct hp_sw_dh_data *h;
int ret;
h = kzalloc(sizeof(*h), GFP_KERNEL);
if (!h)
return -ENOMEM;
h->path_state = HP_SW_PATH_UNINITIALIZED;
h->retries = HP_SW_RETRIES;
h->sdev = sdev;
ret = hp_sw_tur(sdev, h);
if (ret != SCSI_DH_OK || h->path_state == HP_SW_PATH_UNINITIALIZED)
goto failed;
sdev_printk(KERN_INFO, sdev, "%s: attached to %s path\n",
HP_SW_NAME, h->path_state == HP_SW_PATH_ACTIVE?
"active":"passive");
sdev->handler_data = h;
return 0;
failed:
kfree(h);
return -EINVAL;
}
static void hp_sw_bus_detach( struct scsi_device *sdev )
{
kfree(sdev->handler_data);
sdev->handler_data = NULL;
}
static struct scsi_device_handler hp_sw_dh = {
.name = HP_SW_NAME,
.module = THIS_MODULE,
.attach = hp_sw_bus_attach,
.detach = hp_sw_bus_detach,
.activate = hp_sw_activate,
.prep_fn = hp_sw_prep_fn,
};
static int __init hp_sw_init(void)
{
return scsi_register_device_handler(&hp_sw_dh);
}
static void __exit hp_sw_exit(void)
{
scsi_unregister_device_handler(&hp_sw_dh);
}
module_init(hp_sw_init);
module_exit(hp_sw_exit);
MODULE_DESCRIPTION("HP Active/Passive driver");
MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu");
MODULE_LICENSE("GPL");
|
