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1/*
2 * SCSI RDMA (SRP) transport class
3 *
4 * Copyright (C) 2007 FUJITA Tomonori <tomof@acm.org>
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License as
8 * published by the Free Software Foundation, version 2 of the
9 * License.
10 *
11 * This program is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
19 * 02110-1301 USA
20 */
21#include <linux/init.h>
22#include <linux/module.h>
23#include <linux/jiffies.h>
24#include <linux/err.h>
25#include <linux/slab.h>
26#include <linux/string.h>
27
28#include <scsi/scsi.h>
29#include <scsi/scsi_device.h>
30#include <scsi/scsi_host.h>
31#include <scsi/scsi_transport.h>
32#include <scsi/scsi_transport_srp.h>
33#include "scsi_transport_srp_internal.h"
34
35struct srp_host_attrs {
36 atomic_t next_port_id;
37};
38#define to_srp_host_attrs(host) ((struct srp_host_attrs *)(host)->shost_data)
39
40#define SRP_HOST_ATTRS 0
41#define SRP_RPORT_ATTRS 2
42
43struct srp_internal {
44 struct scsi_transport_template t;
45 struct srp_function_template *f;
46
47 struct device_attribute *host_attrs[SRP_HOST_ATTRS + 1];
48
49 struct device_attribute *rport_attrs[SRP_RPORT_ATTRS + 1];
50 struct device_attribute private_rport_attrs[SRP_RPORT_ATTRS];
51 struct transport_container rport_attr_cont;
52};
53
54#define to_srp_internal(tmpl) container_of(tmpl, struct srp_internal, t)
55
56#define dev_to_rport(d) container_of(d, struct srp_rport, dev)
57#define transport_class_to_srp_rport(dev) dev_to_rport((dev)->parent)
58
59static int srp_host_setup(struct transport_container *tc, struct device *dev,
60 struct device *cdev)
61{
62 struct Scsi_Host *shost = dev_to_shost(dev);
63 struct srp_host_attrs *srp_host = to_srp_host_attrs(shost);
64
65 atomic_set(&srp_host->next_port_id, 0);
66 return 0;
67}
68
69static DECLARE_TRANSPORT_CLASS(srp_host_class, "srp_host", srp_host_setup,
70 NULL, NULL);
71
72static DECLARE_TRANSPORT_CLASS(srp_rport_class, "srp_remote_ports",
73 NULL, NULL, NULL);
74
75#define SETUP_TEMPLATE(attrb, field, perm, test, ro_test, ro_perm) \
76 i->private_##attrb[count] = dev_attr_##field; \
77 i->private_##attrb[count].attr.mode = perm; \
78 if (ro_test) { \
79 i->private_##attrb[count].attr.mode = ro_perm; \
80 i->private_##attrb[count].store = NULL; \
81 } \
82 i->attrb[count] = &i->private_##attrb[count]; \
83 if (test) \
84 count++
85
86#define SETUP_RPORT_ATTRIBUTE_RD(field) \
87 SETUP_TEMPLATE(rport_attrs, field, S_IRUGO, 1, 0, 0)
88
89#define SETUP_RPORT_ATTRIBUTE_RW(field) \
90 SETUP_TEMPLATE(rport_attrs, field, S_IRUGO | S_IWUSR, \
91 1, 1, S_IRUGO)
92
93#define SRP_PID(p) \
94 (p)->port_id[0], (p)->port_id[1], (p)->port_id[2], (p)->port_id[3], \
95 (p)->port_id[4], (p)->port_id[5], (p)->port_id[6], (p)->port_id[7], \
96 (p)->port_id[8], (p)->port_id[9], (p)->port_id[10], (p)->port_id[11], \
97 (p)->port_id[12], (p)->port_id[13], (p)->port_id[14], (p)->port_id[15]
98
99#define SRP_PID_FMT "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:" \
100 "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x"
101
102static ssize_t
103show_srp_rport_id(struct device *dev, struct device_attribute *attr,
104 char *buf)
105{
106 struct srp_rport *rport = transport_class_to_srp_rport(dev);
107 return sprintf(buf, SRP_PID_FMT "\n", SRP_PID(rport));
108}
109
110static DEVICE_ATTR(port_id, S_IRUGO, show_srp_rport_id, NULL);
111
112static const struct {
113 u32 value;
114 char *name;
115} srp_rport_role_names[] = {
116 {SRP_RPORT_ROLE_INITIATOR, "SRP Initiator"},
117 {SRP_RPORT_ROLE_TARGET, "SRP Target"},
118};
119
120static ssize_t
121show_srp_rport_roles(struct device *dev, struct device_attribute *attr,
122 char *buf)
123{
124 struct srp_rport *rport = transport_class_to_srp_rport(dev);
125 int i;
126 char *name = NULL;
127
128 for (i = 0; i < ARRAY_SIZE(srp_rport_role_names); i++)
129 if (srp_rport_role_names[i].value == rport->roles) {
130 name = srp_rport_role_names[i].name;
131 break;
132 }
133 return sprintf(buf, "%s\n", name ? : "unknown");
134}
135
136static DEVICE_ATTR(roles, S_IRUGO, show_srp_rport_roles, NULL);
137
138static void srp_rport_release(struct device *dev)
139{
140 struct srp_rport *rport = dev_to_rport(dev);
141
142 put_device(dev->parent);
143 kfree(rport);
144}
145
146static int scsi_is_srp_rport(const struct device *dev)
147{
148 return dev->release == srp_rport_release;
149}
150
151static int srp_rport_match(struct attribute_container *cont,
152 struct device *dev)
153{
154 struct Scsi_Host *shost;
155 struct srp_internal *i;
156
157 if (!scsi_is_srp_rport(dev))
158 return 0;
159
160 shost = dev_to_shost(dev->parent);
161 if (!shost->transportt)
162 return 0;
163 if (shost->transportt->host_attrs.ac.class != &srp_host_class.class)
164 return 0;
165
166 i = to_srp_internal(shost->transportt);
167 return &i->rport_attr_cont.ac == cont;
168}
169
170static int srp_host_match(struct attribute_container *cont, struct device *dev)
171{
172 struct Scsi_Host *shost;
173 struct srp_internal *i;
174
175 if (!scsi_is_host_device(dev))
176 return 0;
177
178 shost = dev_to_shost(dev);
179 if (!shost->transportt)
180 return 0;
181 if (shost->transportt->host_attrs.ac.class != &srp_host_class.class)
182 return 0;
183
184 i = to_srp_internal(shost->transportt);
185 return &i->t.host_attrs.ac == cont;
186}
187
188/**
189 * srp_rport_add - add a SRP remote port to the device hierarchy
190 * @shost: scsi host the remote port is connected to.
191 * @ids: The port id for the remote port.
192 *
193 * Publishes a port to the rest of the system.
194 */
195struct srp_rport *srp_rport_add(struct Scsi_Host *shost,
196 struct srp_rport_identifiers *ids)
197{
198 struct srp_rport *rport;
199 struct device *parent = &shost->shost_gendev;
200 int id, ret;
201
202 rport = kzalloc(sizeof(*rport), GFP_KERNEL);
203 if (!rport)
204 return ERR_PTR(-ENOMEM);
205
206 device_initialize(&rport->dev);
207
208 rport->dev.parent = get_device(parent);
209 rport->dev.release = srp_rport_release;
210
211 memcpy(rport->port_id, ids->port_id, sizeof(rport->port_id));
212 rport->roles = ids->roles;
213
214 id = atomic_inc_return(&to_srp_host_attrs(shost)->next_port_id);
215 dev_set_name(&rport->dev, "port-%d:%d", shost->host_no, id);
216
217 transport_setup_device(&rport->dev);
218
219 ret = device_add(&rport->dev);
220 if (ret) {
221 transport_destroy_device(&rport->dev);
222 put_device(&rport->dev);
223 return ERR_PTR(ret);
224 }
225
226 if (shost->active_mode & MODE_TARGET &&
227 ids->roles == SRP_RPORT_ROLE_INITIATOR) {
228 ret = srp_tgt_it_nexus_create(shost, (unsigned long)rport,
229 rport->port_id);
230 if (ret) {
231 device_del(&rport->dev);
232 transport_destroy_device(&rport->dev);
233 put_device(&rport->dev);
234 return ERR_PTR(ret);
235 }
236 }
237
238 transport_add_device(&rport->dev);
239 transport_configure_device(&rport->dev);
240
241 return rport;
242}
243EXPORT_SYMBOL_GPL(srp_rport_add);
244
245/**
246 * srp_rport_del - remove a SRP remote port
247 * @rport: SRP remote port to remove
248 *
249 * Removes the specified SRP remote port.
250 */
251void srp_rport_del(struct srp_rport *rport)
252{
253 struct device *dev = &rport->dev;
254 struct Scsi_Host *shost = dev_to_shost(dev->parent);
255
256 if (shost->active_mode & MODE_TARGET &&
257 rport->roles == SRP_RPORT_ROLE_INITIATOR)
258 srp_tgt_it_nexus_destroy(shost, (unsigned long)rport);
259
260 transport_remove_device(dev);
261 device_del(dev);
262 transport_destroy_device(dev);
263 put_device(dev);
264}
265EXPORT_SYMBOL_GPL(srp_rport_del);
266
267static int do_srp_rport_del(struct device *dev, void *data)
268{
269 if (scsi_is_srp_rport(dev))
270 srp_rport_del(dev_to_rport(dev));
271 return 0;
272}
273
274/**
275 * srp_remove_host - tear down a Scsi_Host's SRP data structures
276 * @shost: Scsi Host that is torn down
277 *
278 * Removes all SRP remote ports for a given Scsi_Host.
279 * Must be called just before scsi_remove_host for SRP HBAs.
280 */
281void srp_remove_host(struct Scsi_Host *shost)
282{
283 device_for_each_child(&shost->shost_gendev, NULL, do_srp_rport_del);
284}
285EXPORT_SYMBOL_GPL(srp_remove_host);
286
287static int srp_tsk_mgmt_response(struct Scsi_Host *shost, u64 nexus, u64 tm_id,
288 int result)
289{
290 struct srp_internal *i = to_srp_internal(shost->transportt);
291 return i->f->tsk_mgmt_response(shost, nexus, tm_id, result);
292}
293
294static int srp_it_nexus_response(struct Scsi_Host *shost, u64 nexus, int result)
295{
296 struct srp_internal *i = to_srp_internal(shost->transportt);
297 return i->f->it_nexus_response(shost, nexus, result);
298}
299
300/**
301 * srp_attach_transport - instantiate SRP transport template
302 * @ft: SRP transport class function template
303 */
304struct scsi_transport_template *
305srp_attach_transport(struct srp_function_template *ft)
306{
307 int count;
308 struct srp_internal *i;
309
310 i = kzalloc(sizeof(*i), GFP_KERNEL);
311 if (!i)
312 return NULL;
313
314 i->t.tsk_mgmt_response = srp_tsk_mgmt_response;
315 i->t.it_nexus_response = srp_it_nexus_response;
316
317 i->t.host_size = sizeof(struct srp_host_attrs);
318 i->t.host_attrs.ac.attrs = &i->host_attrs[0];
319 i->t.host_attrs.ac.class = &srp_host_class.class;
320 i->t.host_attrs.ac.match = srp_host_match;
321 i->host_attrs[0] = NULL;
322 transport_container_register(&i->t.host_attrs);
323
324 i->rport_attr_cont.ac.attrs = &i->rport_attrs[0];
325 i->rport_attr_cont.ac.class = &srp_rport_class.class;
326 i->rport_attr_cont.ac.match = srp_rport_match;
327 transport_container_register(&i->rport_attr_cont);
328
329 count = 0;
330 SETUP_RPORT_ATTRIBUTE_RD(port_id);
331 SETUP_RPORT_ATTRIBUTE_RD(roles);
332 i->rport_attrs[count] = NULL;
333
334 i->f = ft;
335
336 return &i->t;
337}
338EXPORT_SYMBOL_GPL(srp_attach_transport);
339
340/**
341 * srp_release_transport - release SRP transport template instance
342 * @t: transport template instance
343 */
344void srp_release_transport(struct scsi_transport_template *t)
345{
346 struct srp_internal *i = to_srp_internal(t);
347
348 transport_container_unregister(&i->t.host_attrs);
349 transport_container_unregister(&i->rport_attr_cont);
350
351 kfree(i);
352}
353EXPORT_SYMBOL_GPL(srp_release_transport);
354
355static __init int srp_transport_init(void)
356{
357 int ret;
358
359 ret = transport_class_register(&srp_host_class);
360 if (ret)
361 return ret;
362 ret = transport_class_register(&srp_rport_class);
363 if (ret)
364 goto unregister_host_class;
365
366 return 0;
367unregister_host_class:
368 transport_class_unregister(&srp_host_class);
369 return ret;
370}
371
372static void __exit srp_transport_exit(void)
373{
374 transport_class_unregister(&srp_host_class);
375 transport_class_unregister(&srp_rport_class);
376}
377
378MODULE_AUTHOR("FUJITA Tomonori");
379MODULE_DESCRIPTION("SRP Transport Attributes");
380MODULE_LICENSE("GPL");
381
382module_init(srp_transport_init);
383module_exit(srp_transport_exit);
1/*
2 * SCSI RDMA (SRP) transport class
3 *
4 * Copyright (C) 2007 FUJITA Tomonori <tomof@acm.org>
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License as
8 * published by the Free Software Foundation, version 2 of the
9 * License.
10 *
11 * This program is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
19 * 02110-1301 USA
20 */
21#include <linux/init.h>
22#include <linux/module.h>
23#include <linux/jiffies.h>
24#include <linux/err.h>
25#include <linux/slab.h>
26#include <linux/string.h>
27
28#include <scsi/scsi.h>
29#include <scsi/scsi_cmnd.h>
30#include <scsi/scsi_device.h>
31#include <scsi/scsi_host.h>
32#include <scsi/scsi_transport.h>
33#include <scsi/scsi_transport_srp.h>
34#include "scsi_priv.h"
35
36struct srp_host_attrs {
37 atomic_t next_port_id;
38};
39#define to_srp_host_attrs(host) ((struct srp_host_attrs *)(host)->shost_data)
40
41#define SRP_HOST_ATTRS 0
42#define SRP_RPORT_ATTRS 8
43
44struct srp_internal {
45 struct scsi_transport_template t;
46 struct srp_function_template *f;
47
48 struct device_attribute *host_attrs[SRP_HOST_ATTRS + 1];
49
50 struct device_attribute *rport_attrs[SRP_RPORT_ATTRS + 1];
51 struct transport_container rport_attr_cont;
52};
53
54#define to_srp_internal(tmpl) container_of(tmpl, struct srp_internal, t)
55
56#define dev_to_rport(d) container_of(d, struct srp_rport, dev)
57#define transport_class_to_srp_rport(dev) dev_to_rport((dev)->parent)
58static inline struct Scsi_Host *rport_to_shost(struct srp_rport *r)
59{
60 return dev_to_shost(r->dev.parent);
61}
62
63static inline struct srp_rport *shost_to_rport(struct Scsi_Host *shost)
64{
65 return transport_class_to_srp_rport(&shost->shost_gendev);
66}
67
68/**
69 * srp_tmo_valid() - check timeout combination validity
70 * @reconnect_delay: Reconnect delay in seconds.
71 * @fast_io_fail_tmo: Fast I/O fail timeout in seconds.
72 * @dev_loss_tmo: Device loss timeout in seconds.
73 *
74 * The combination of the timeout parameters must be such that SCSI commands
75 * are finished in a reasonable time. Hence do not allow the fast I/O fail
76 * timeout to exceed SCSI_DEVICE_BLOCK_MAX_TIMEOUT nor allow dev_loss_tmo to
77 * exceed that limit if failing I/O fast has been disabled. Furthermore, these
78 * parameters must be such that multipath can detect failed paths timely.
79 * Hence do not allow all three parameters to be disabled simultaneously.
80 */
81int srp_tmo_valid(int reconnect_delay, int fast_io_fail_tmo, int dev_loss_tmo)
82{
83 if (reconnect_delay < 0 && fast_io_fail_tmo < 0 && dev_loss_tmo < 0)
84 return -EINVAL;
85 if (reconnect_delay == 0)
86 return -EINVAL;
87 if (fast_io_fail_tmo > SCSI_DEVICE_BLOCK_MAX_TIMEOUT)
88 return -EINVAL;
89 if (fast_io_fail_tmo < 0 &&
90 dev_loss_tmo > SCSI_DEVICE_BLOCK_MAX_TIMEOUT)
91 return -EINVAL;
92 if (dev_loss_tmo >= LONG_MAX / HZ)
93 return -EINVAL;
94 if (fast_io_fail_tmo >= 0 && dev_loss_tmo >= 0 &&
95 fast_io_fail_tmo >= dev_loss_tmo)
96 return -EINVAL;
97 return 0;
98}
99EXPORT_SYMBOL_GPL(srp_tmo_valid);
100
101static int srp_host_setup(struct transport_container *tc, struct device *dev,
102 struct device *cdev)
103{
104 struct Scsi_Host *shost = dev_to_shost(dev);
105 struct srp_host_attrs *srp_host = to_srp_host_attrs(shost);
106
107 atomic_set(&srp_host->next_port_id, 0);
108 return 0;
109}
110
111static DECLARE_TRANSPORT_CLASS(srp_host_class, "srp_host", srp_host_setup,
112 NULL, NULL);
113
114static DECLARE_TRANSPORT_CLASS(srp_rport_class, "srp_remote_ports",
115 NULL, NULL, NULL);
116
117static ssize_t
118show_srp_rport_id(struct device *dev, struct device_attribute *attr,
119 char *buf)
120{
121 struct srp_rport *rport = transport_class_to_srp_rport(dev);
122 return sprintf(buf, "%16phC\n", rport->port_id);
123}
124
125static DEVICE_ATTR(port_id, S_IRUGO, show_srp_rport_id, NULL);
126
127static const struct {
128 u32 value;
129 char *name;
130} srp_rport_role_names[] = {
131 {SRP_RPORT_ROLE_INITIATOR, "SRP Initiator"},
132 {SRP_RPORT_ROLE_TARGET, "SRP Target"},
133};
134
135static ssize_t
136show_srp_rport_roles(struct device *dev, struct device_attribute *attr,
137 char *buf)
138{
139 struct srp_rport *rport = transport_class_to_srp_rport(dev);
140 int i;
141 char *name = NULL;
142
143 for (i = 0; i < ARRAY_SIZE(srp_rport_role_names); i++)
144 if (srp_rport_role_names[i].value == rport->roles) {
145 name = srp_rport_role_names[i].name;
146 break;
147 }
148 return sprintf(buf, "%s\n", name ? : "unknown");
149}
150
151static DEVICE_ATTR(roles, S_IRUGO, show_srp_rport_roles, NULL);
152
153static ssize_t store_srp_rport_delete(struct device *dev,
154 struct device_attribute *attr,
155 const char *buf, size_t count)
156{
157 struct srp_rport *rport = transport_class_to_srp_rport(dev);
158 struct Scsi_Host *shost = dev_to_shost(dev);
159 struct srp_internal *i = to_srp_internal(shost->transportt);
160
161 if (i->f->rport_delete) {
162 i->f->rport_delete(rport);
163 return count;
164 } else {
165 return -ENOSYS;
166 }
167}
168
169static DEVICE_ATTR(delete, S_IWUSR, NULL, store_srp_rport_delete);
170
171static ssize_t show_srp_rport_state(struct device *dev,
172 struct device_attribute *attr,
173 char *buf)
174{
175 static const char *const state_name[] = {
176 [SRP_RPORT_RUNNING] = "running",
177 [SRP_RPORT_BLOCKED] = "blocked",
178 [SRP_RPORT_FAIL_FAST] = "fail-fast",
179 [SRP_RPORT_LOST] = "lost",
180 };
181 struct srp_rport *rport = transport_class_to_srp_rport(dev);
182 enum srp_rport_state state = rport->state;
183
184 return sprintf(buf, "%s\n",
185 (unsigned)state < ARRAY_SIZE(state_name) ?
186 state_name[state] : "???");
187}
188
189static DEVICE_ATTR(state, S_IRUGO, show_srp_rport_state, NULL);
190
191static ssize_t srp_show_tmo(char *buf, int tmo)
192{
193 return tmo >= 0 ? sprintf(buf, "%d\n", tmo) : sprintf(buf, "off\n");
194}
195
196int srp_parse_tmo(int *tmo, const char *buf)
197{
198 int res = 0;
199
200 if (strncmp(buf, "off", 3) != 0)
201 res = kstrtoint(buf, 0, tmo);
202 else
203 *tmo = -1;
204
205 return res;
206}
207EXPORT_SYMBOL(srp_parse_tmo);
208
209static ssize_t show_reconnect_delay(struct device *dev,
210 struct device_attribute *attr, char *buf)
211{
212 struct srp_rport *rport = transport_class_to_srp_rport(dev);
213
214 return srp_show_tmo(buf, rport->reconnect_delay);
215}
216
217static ssize_t store_reconnect_delay(struct device *dev,
218 struct device_attribute *attr,
219 const char *buf, const size_t count)
220{
221 struct srp_rport *rport = transport_class_to_srp_rport(dev);
222 int res, delay;
223
224 res = srp_parse_tmo(&delay, buf);
225 if (res)
226 goto out;
227 res = srp_tmo_valid(delay, rport->fast_io_fail_tmo,
228 rport->dev_loss_tmo);
229 if (res)
230 goto out;
231
232 if (rport->reconnect_delay <= 0 && delay > 0 &&
233 rport->state != SRP_RPORT_RUNNING) {
234 queue_delayed_work(system_long_wq, &rport->reconnect_work,
235 delay * HZ);
236 } else if (delay <= 0) {
237 cancel_delayed_work(&rport->reconnect_work);
238 }
239 rport->reconnect_delay = delay;
240 res = count;
241
242out:
243 return res;
244}
245
246static DEVICE_ATTR(reconnect_delay, S_IRUGO | S_IWUSR, show_reconnect_delay,
247 store_reconnect_delay);
248
249static ssize_t show_failed_reconnects(struct device *dev,
250 struct device_attribute *attr, char *buf)
251{
252 struct srp_rport *rport = transport_class_to_srp_rport(dev);
253
254 return sprintf(buf, "%d\n", rport->failed_reconnects);
255}
256
257static DEVICE_ATTR(failed_reconnects, S_IRUGO, show_failed_reconnects, NULL);
258
259static ssize_t show_srp_rport_fast_io_fail_tmo(struct device *dev,
260 struct device_attribute *attr,
261 char *buf)
262{
263 struct srp_rport *rport = transport_class_to_srp_rport(dev);
264
265 return srp_show_tmo(buf, rport->fast_io_fail_tmo);
266}
267
268static ssize_t store_srp_rport_fast_io_fail_tmo(struct device *dev,
269 struct device_attribute *attr,
270 const char *buf, size_t count)
271{
272 struct srp_rport *rport = transport_class_to_srp_rport(dev);
273 int res;
274 int fast_io_fail_tmo;
275
276 res = srp_parse_tmo(&fast_io_fail_tmo, buf);
277 if (res)
278 goto out;
279 res = srp_tmo_valid(rport->reconnect_delay, fast_io_fail_tmo,
280 rport->dev_loss_tmo);
281 if (res)
282 goto out;
283 rport->fast_io_fail_tmo = fast_io_fail_tmo;
284 res = count;
285
286out:
287 return res;
288}
289
290static DEVICE_ATTR(fast_io_fail_tmo, S_IRUGO | S_IWUSR,
291 show_srp_rport_fast_io_fail_tmo,
292 store_srp_rport_fast_io_fail_tmo);
293
294static ssize_t show_srp_rport_dev_loss_tmo(struct device *dev,
295 struct device_attribute *attr,
296 char *buf)
297{
298 struct srp_rport *rport = transport_class_to_srp_rport(dev);
299
300 return srp_show_tmo(buf, rport->dev_loss_tmo);
301}
302
303static ssize_t store_srp_rport_dev_loss_tmo(struct device *dev,
304 struct device_attribute *attr,
305 const char *buf, size_t count)
306{
307 struct srp_rport *rport = transport_class_to_srp_rport(dev);
308 int res;
309 int dev_loss_tmo;
310
311 res = srp_parse_tmo(&dev_loss_tmo, buf);
312 if (res)
313 goto out;
314 res = srp_tmo_valid(rport->reconnect_delay, rport->fast_io_fail_tmo,
315 dev_loss_tmo);
316 if (res)
317 goto out;
318 rport->dev_loss_tmo = dev_loss_tmo;
319 res = count;
320
321out:
322 return res;
323}
324
325static DEVICE_ATTR(dev_loss_tmo, S_IRUGO | S_IWUSR,
326 show_srp_rport_dev_loss_tmo,
327 store_srp_rport_dev_loss_tmo);
328
329static int srp_rport_set_state(struct srp_rport *rport,
330 enum srp_rport_state new_state)
331{
332 enum srp_rport_state old_state = rport->state;
333
334 lockdep_assert_held(&rport->mutex);
335
336 switch (new_state) {
337 case SRP_RPORT_RUNNING:
338 switch (old_state) {
339 case SRP_RPORT_LOST:
340 goto invalid;
341 default:
342 break;
343 }
344 break;
345 case SRP_RPORT_BLOCKED:
346 switch (old_state) {
347 case SRP_RPORT_RUNNING:
348 break;
349 default:
350 goto invalid;
351 }
352 break;
353 case SRP_RPORT_FAIL_FAST:
354 switch (old_state) {
355 case SRP_RPORT_LOST:
356 goto invalid;
357 default:
358 break;
359 }
360 break;
361 case SRP_RPORT_LOST:
362 break;
363 }
364 rport->state = new_state;
365 return 0;
366
367invalid:
368 return -EINVAL;
369}
370
371/**
372 * srp_reconnect_work() - reconnect and schedule a new attempt if necessary
373 * @work: Work structure used for scheduling this operation.
374 */
375static void srp_reconnect_work(struct work_struct *work)
376{
377 struct srp_rport *rport = container_of(to_delayed_work(work),
378 struct srp_rport, reconnect_work);
379 struct Scsi_Host *shost = rport_to_shost(rport);
380 int delay, res;
381
382 res = srp_reconnect_rport(rport);
383 if (res != 0) {
384 shost_printk(KERN_ERR, shost,
385 "reconnect attempt %d failed (%d)\n",
386 ++rport->failed_reconnects, res);
387 delay = rport->reconnect_delay *
388 min(100, max(1, rport->failed_reconnects - 10));
389 if (delay > 0)
390 queue_delayed_work(system_long_wq,
391 &rport->reconnect_work, delay * HZ);
392 }
393}
394
395static void __rport_fail_io_fast(struct srp_rport *rport)
396{
397 struct Scsi_Host *shost = rport_to_shost(rport);
398 struct srp_internal *i;
399
400 lockdep_assert_held(&rport->mutex);
401
402 if (srp_rport_set_state(rport, SRP_RPORT_FAIL_FAST))
403 return;
404 /*
405 * Call scsi_target_block() to wait for ongoing shost->queuecommand()
406 * calls before invoking i->f->terminate_rport_io().
407 */
408 scsi_target_block(rport->dev.parent);
409 scsi_target_unblock(rport->dev.parent, SDEV_TRANSPORT_OFFLINE);
410
411 /* Involve the LLD if possible to terminate all I/O on the rport. */
412 i = to_srp_internal(shost->transportt);
413 if (i->f->terminate_rport_io)
414 i->f->terminate_rport_io(rport);
415}
416
417/**
418 * rport_fast_io_fail_timedout() - fast I/O failure timeout handler
419 * @work: Work structure used for scheduling this operation.
420 */
421static void rport_fast_io_fail_timedout(struct work_struct *work)
422{
423 struct srp_rport *rport = container_of(to_delayed_work(work),
424 struct srp_rport, fast_io_fail_work);
425 struct Scsi_Host *shost = rport_to_shost(rport);
426
427 pr_info("fast_io_fail_tmo expired for SRP %s / %s.\n",
428 dev_name(&rport->dev), dev_name(&shost->shost_gendev));
429
430 mutex_lock(&rport->mutex);
431 if (rport->state == SRP_RPORT_BLOCKED)
432 __rport_fail_io_fast(rport);
433 mutex_unlock(&rport->mutex);
434}
435
436/**
437 * rport_dev_loss_timedout() - device loss timeout handler
438 * @work: Work structure used for scheduling this operation.
439 */
440static void rport_dev_loss_timedout(struct work_struct *work)
441{
442 struct srp_rport *rport = container_of(to_delayed_work(work),
443 struct srp_rport, dev_loss_work);
444 struct Scsi_Host *shost = rport_to_shost(rport);
445 struct srp_internal *i = to_srp_internal(shost->transportt);
446
447 pr_info("dev_loss_tmo expired for SRP %s / %s.\n",
448 dev_name(&rport->dev), dev_name(&shost->shost_gendev));
449
450 mutex_lock(&rport->mutex);
451 WARN_ON(srp_rport_set_state(rport, SRP_RPORT_LOST) != 0);
452 scsi_target_unblock(rport->dev.parent, SDEV_TRANSPORT_OFFLINE);
453 mutex_unlock(&rport->mutex);
454
455 i->f->rport_delete(rport);
456}
457
458static void __srp_start_tl_fail_timers(struct srp_rport *rport)
459{
460 struct Scsi_Host *shost = rport_to_shost(rport);
461 int delay, fast_io_fail_tmo, dev_loss_tmo;
462
463 lockdep_assert_held(&rport->mutex);
464
465 delay = rport->reconnect_delay;
466 fast_io_fail_tmo = rport->fast_io_fail_tmo;
467 dev_loss_tmo = rport->dev_loss_tmo;
468 pr_debug("%s current state: %d\n", dev_name(&shost->shost_gendev),
469 rport->state);
470
471 if (rport->state == SRP_RPORT_LOST)
472 return;
473 if (delay > 0)
474 queue_delayed_work(system_long_wq, &rport->reconnect_work,
475 1UL * delay * HZ);
476 if ((fast_io_fail_tmo >= 0 || dev_loss_tmo >= 0) &&
477 srp_rport_set_state(rport, SRP_RPORT_BLOCKED) == 0) {
478 pr_debug("%s new state: %d\n", dev_name(&shost->shost_gendev),
479 rport->state);
480 scsi_target_block(&shost->shost_gendev);
481 if (fast_io_fail_tmo >= 0)
482 queue_delayed_work(system_long_wq,
483 &rport->fast_io_fail_work,
484 1UL * fast_io_fail_tmo * HZ);
485 if (dev_loss_tmo >= 0)
486 queue_delayed_work(system_long_wq,
487 &rport->dev_loss_work,
488 1UL * dev_loss_tmo * HZ);
489 }
490}
491
492/**
493 * srp_start_tl_fail_timers() - start the transport layer failure timers
494 * @rport: SRP target port.
495 *
496 * Start the transport layer fast I/O failure and device loss timers. Do not
497 * modify a timer that was already started.
498 */
499void srp_start_tl_fail_timers(struct srp_rport *rport)
500{
501 mutex_lock(&rport->mutex);
502 __srp_start_tl_fail_timers(rport);
503 mutex_unlock(&rport->mutex);
504}
505EXPORT_SYMBOL(srp_start_tl_fail_timers);
506
507/**
508 * srp_reconnect_rport() - reconnect to an SRP target port
509 * @rport: SRP target port.
510 *
511 * Blocks SCSI command queueing before invoking reconnect() such that
512 * queuecommand() won't be invoked concurrently with reconnect() from outside
513 * the SCSI EH. This is important since a reconnect() implementation may
514 * reallocate resources needed by queuecommand().
515 *
516 * Notes:
517 * - This function neither waits until outstanding requests have finished nor
518 * tries to abort these. It is the responsibility of the reconnect()
519 * function to finish outstanding commands before reconnecting to the target
520 * port.
521 * - It is the responsibility of the caller to ensure that the resources
522 * reallocated by the reconnect() function won't be used while this function
523 * is in progress. One possible strategy is to invoke this function from
524 * the context of the SCSI EH thread only. Another possible strategy is to
525 * lock the rport mutex inside each SCSI LLD callback that can be invoked by
526 * the SCSI EH (the scsi_host_template.eh_*() functions and also the
527 * scsi_host_template.queuecommand() function).
528 */
529int srp_reconnect_rport(struct srp_rport *rport)
530{
531 struct Scsi_Host *shost = rport_to_shost(rport);
532 struct srp_internal *i = to_srp_internal(shost->transportt);
533 struct scsi_device *sdev;
534 int res;
535
536 pr_debug("SCSI host %s\n", dev_name(&shost->shost_gendev));
537
538 res = mutex_lock_interruptible(&rport->mutex);
539 if (res)
540 goto out;
541 scsi_target_block(&shost->shost_gendev);
542 res = rport->state != SRP_RPORT_LOST ? i->f->reconnect(rport) : -ENODEV;
543 pr_debug("%s (state %d): transport.reconnect() returned %d\n",
544 dev_name(&shost->shost_gendev), rport->state, res);
545 if (res == 0) {
546 cancel_delayed_work(&rport->fast_io_fail_work);
547 cancel_delayed_work(&rport->dev_loss_work);
548
549 rport->failed_reconnects = 0;
550 srp_rport_set_state(rport, SRP_RPORT_RUNNING);
551 scsi_target_unblock(&shost->shost_gendev, SDEV_RUNNING);
552 /*
553 * If the SCSI error handler has offlined one or more devices,
554 * invoking scsi_target_unblock() won't change the state of
555 * these devices into running so do that explicitly.
556 */
557 spin_lock_irq(shost->host_lock);
558 __shost_for_each_device(sdev, shost)
559 if (sdev->sdev_state == SDEV_OFFLINE)
560 sdev->sdev_state = SDEV_RUNNING;
561 spin_unlock_irq(shost->host_lock);
562 } else if (rport->state == SRP_RPORT_RUNNING) {
563 /*
564 * srp_reconnect_rport() has been invoked with fast_io_fail
565 * and dev_loss off. Mark the port as failed and start the TL
566 * failure timers if these had not yet been started.
567 */
568 __rport_fail_io_fast(rport);
569 scsi_target_unblock(&shost->shost_gendev,
570 SDEV_TRANSPORT_OFFLINE);
571 __srp_start_tl_fail_timers(rport);
572 } else if (rport->state != SRP_RPORT_BLOCKED) {
573 scsi_target_unblock(&shost->shost_gendev,
574 SDEV_TRANSPORT_OFFLINE);
575 }
576 mutex_unlock(&rport->mutex);
577
578out:
579 return res;
580}
581EXPORT_SYMBOL(srp_reconnect_rport);
582
583/**
584 * srp_timed_out() - SRP transport intercept of the SCSI timeout EH
585 * @scmd: SCSI command.
586 *
587 * If a timeout occurs while an rport is in the blocked state, ask the SCSI
588 * EH to continue waiting (BLK_EH_RESET_TIMER). Otherwise let the SCSI core
589 * handle the timeout (BLK_EH_NOT_HANDLED).
590 *
591 * Note: This function is called from soft-IRQ context and with the request
592 * queue lock held.
593 */
594static enum blk_eh_timer_return srp_timed_out(struct scsi_cmnd *scmd)
595{
596 struct scsi_device *sdev = scmd->device;
597 struct Scsi_Host *shost = sdev->host;
598 struct srp_internal *i = to_srp_internal(shost->transportt);
599 struct srp_rport *rport = shost_to_rport(shost);
600
601 pr_debug("timeout for sdev %s\n", dev_name(&sdev->sdev_gendev));
602 return rport->fast_io_fail_tmo < 0 && rport->dev_loss_tmo < 0 &&
603 i->f->reset_timer_if_blocked && scsi_device_blocked(sdev) ?
604 BLK_EH_RESET_TIMER : BLK_EH_NOT_HANDLED;
605}
606
607static void srp_rport_release(struct device *dev)
608{
609 struct srp_rport *rport = dev_to_rport(dev);
610
611 put_device(dev->parent);
612 kfree(rport);
613}
614
615static int scsi_is_srp_rport(const struct device *dev)
616{
617 return dev->release == srp_rport_release;
618}
619
620static int srp_rport_match(struct attribute_container *cont,
621 struct device *dev)
622{
623 struct Scsi_Host *shost;
624 struct srp_internal *i;
625
626 if (!scsi_is_srp_rport(dev))
627 return 0;
628
629 shost = dev_to_shost(dev->parent);
630 if (!shost->transportt)
631 return 0;
632 if (shost->transportt->host_attrs.ac.class != &srp_host_class.class)
633 return 0;
634
635 i = to_srp_internal(shost->transportt);
636 return &i->rport_attr_cont.ac == cont;
637}
638
639static int srp_host_match(struct attribute_container *cont, struct device *dev)
640{
641 struct Scsi_Host *shost;
642 struct srp_internal *i;
643
644 if (!scsi_is_host_device(dev))
645 return 0;
646
647 shost = dev_to_shost(dev);
648 if (!shost->transportt)
649 return 0;
650 if (shost->transportt->host_attrs.ac.class != &srp_host_class.class)
651 return 0;
652
653 i = to_srp_internal(shost->transportt);
654 return &i->t.host_attrs.ac == cont;
655}
656
657/**
658 * srp_rport_get() - increment rport reference count
659 * @rport: SRP target port.
660 */
661void srp_rport_get(struct srp_rport *rport)
662{
663 get_device(&rport->dev);
664}
665EXPORT_SYMBOL(srp_rport_get);
666
667/**
668 * srp_rport_put() - decrement rport reference count
669 * @rport: SRP target port.
670 */
671void srp_rport_put(struct srp_rport *rport)
672{
673 put_device(&rport->dev);
674}
675EXPORT_SYMBOL(srp_rport_put);
676
677/**
678 * srp_rport_add - add a SRP remote port to the device hierarchy
679 * @shost: scsi host the remote port is connected to.
680 * @ids: The port id for the remote port.
681 *
682 * Publishes a port to the rest of the system.
683 */
684struct srp_rport *srp_rport_add(struct Scsi_Host *shost,
685 struct srp_rport_identifiers *ids)
686{
687 struct srp_rport *rport;
688 struct device *parent = &shost->shost_gendev;
689 struct srp_internal *i = to_srp_internal(shost->transportt);
690 int id, ret;
691
692 rport = kzalloc(sizeof(*rport), GFP_KERNEL);
693 if (!rport)
694 return ERR_PTR(-ENOMEM);
695
696 mutex_init(&rport->mutex);
697
698 device_initialize(&rport->dev);
699
700 rport->dev.parent = get_device(parent);
701 rport->dev.release = srp_rport_release;
702
703 memcpy(rport->port_id, ids->port_id, sizeof(rport->port_id));
704 rport->roles = ids->roles;
705
706 if (i->f->reconnect)
707 rport->reconnect_delay = i->f->reconnect_delay ?
708 *i->f->reconnect_delay : 10;
709 INIT_DELAYED_WORK(&rport->reconnect_work, srp_reconnect_work);
710 rport->fast_io_fail_tmo = i->f->fast_io_fail_tmo ?
711 *i->f->fast_io_fail_tmo : 15;
712 rport->dev_loss_tmo = i->f->dev_loss_tmo ? *i->f->dev_loss_tmo : 60;
713 INIT_DELAYED_WORK(&rport->fast_io_fail_work,
714 rport_fast_io_fail_timedout);
715 INIT_DELAYED_WORK(&rport->dev_loss_work, rport_dev_loss_timedout);
716
717 id = atomic_inc_return(&to_srp_host_attrs(shost)->next_port_id);
718 dev_set_name(&rport->dev, "port-%d:%d", shost->host_no, id);
719
720 transport_setup_device(&rport->dev);
721
722 ret = device_add(&rport->dev);
723 if (ret) {
724 transport_destroy_device(&rport->dev);
725 put_device(&rport->dev);
726 return ERR_PTR(ret);
727 }
728
729 transport_add_device(&rport->dev);
730 transport_configure_device(&rport->dev);
731
732 return rport;
733}
734EXPORT_SYMBOL_GPL(srp_rport_add);
735
736/**
737 * srp_rport_del - remove a SRP remote port
738 * @rport: SRP remote port to remove
739 *
740 * Removes the specified SRP remote port.
741 */
742void srp_rport_del(struct srp_rport *rport)
743{
744 struct device *dev = &rport->dev;
745
746 transport_remove_device(dev);
747 device_del(dev);
748 transport_destroy_device(dev);
749
750 put_device(dev);
751}
752EXPORT_SYMBOL_GPL(srp_rport_del);
753
754static int do_srp_rport_del(struct device *dev, void *data)
755{
756 if (scsi_is_srp_rport(dev))
757 srp_rport_del(dev_to_rport(dev));
758 return 0;
759}
760
761/**
762 * srp_remove_host - tear down a Scsi_Host's SRP data structures
763 * @shost: Scsi Host that is torn down
764 *
765 * Removes all SRP remote ports for a given Scsi_Host.
766 * Must be called just before scsi_remove_host for SRP HBAs.
767 */
768void srp_remove_host(struct Scsi_Host *shost)
769{
770 device_for_each_child(&shost->shost_gendev, NULL, do_srp_rport_del);
771}
772EXPORT_SYMBOL_GPL(srp_remove_host);
773
774/**
775 * srp_stop_rport_timers - stop the transport layer recovery timers
776 * @rport: SRP remote port for which to stop the timers.
777 *
778 * Must be called after srp_remove_host() and scsi_remove_host(). The caller
779 * must hold a reference on the rport (rport->dev) and on the SCSI host
780 * (rport->dev.parent).
781 */
782void srp_stop_rport_timers(struct srp_rport *rport)
783{
784 mutex_lock(&rport->mutex);
785 if (rport->state == SRP_RPORT_BLOCKED)
786 __rport_fail_io_fast(rport);
787 srp_rport_set_state(rport, SRP_RPORT_LOST);
788 mutex_unlock(&rport->mutex);
789
790 cancel_delayed_work_sync(&rport->reconnect_work);
791 cancel_delayed_work_sync(&rport->fast_io_fail_work);
792 cancel_delayed_work_sync(&rport->dev_loss_work);
793}
794EXPORT_SYMBOL_GPL(srp_stop_rport_timers);
795
796static int srp_tsk_mgmt_response(struct Scsi_Host *shost, u64 nexus, u64 tm_id,
797 int result)
798{
799 struct srp_internal *i = to_srp_internal(shost->transportt);
800 return i->f->tsk_mgmt_response(shost, nexus, tm_id, result);
801}
802
803static int srp_it_nexus_response(struct Scsi_Host *shost, u64 nexus, int result)
804{
805 struct srp_internal *i = to_srp_internal(shost->transportt);
806 return i->f->it_nexus_response(shost, nexus, result);
807}
808
809/**
810 * srp_attach_transport - instantiate SRP transport template
811 * @ft: SRP transport class function template
812 */
813struct scsi_transport_template *
814srp_attach_transport(struct srp_function_template *ft)
815{
816 int count;
817 struct srp_internal *i;
818
819 i = kzalloc(sizeof(*i), GFP_KERNEL);
820 if (!i)
821 return NULL;
822
823 i->t.eh_timed_out = srp_timed_out;
824
825 i->t.tsk_mgmt_response = srp_tsk_mgmt_response;
826 i->t.it_nexus_response = srp_it_nexus_response;
827
828 i->t.host_size = sizeof(struct srp_host_attrs);
829 i->t.host_attrs.ac.attrs = &i->host_attrs[0];
830 i->t.host_attrs.ac.class = &srp_host_class.class;
831 i->t.host_attrs.ac.match = srp_host_match;
832 i->host_attrs[0] = NULL;
833 transport_container_register(&i->t.host_attrs);
834
835 i->rport_attr_cont.ac.attrs = &i->rport_attrs[0];
836 i->rport_attr_cont.ac.class = &srp_rport_class.class;
837 i->rport_attr_cont.ac.match = srp_rport_match;
838
839 count = 0;
840 i->rport_attrs[count++] = &dev_attr_port_id;
841 i->rport_attrs[count++] = &dev_attr_roles;
842 if (ft->has_rport_state) {
843 i->rport_attrs[count++] = &dev_attr_state;
844 i->rport_attrs[count++] = &dev_attr_fast_io_fail_tmo;
845 i->rport_attrs[count++] = &dev_attr_dev_loss_tmo;
846 }
847 if (ft->reconnect) {
848 i->rport_attrs[count++] = &dev_attr_reconnect_delay;
849 i->rport_attrs[count++] = &dev_attr_failed_reconnects;
850 }
851 if (ft->rport_delete)
852 i->rport_attrs[count++] = &dev_attr_delete;
853 i->rport_attrs[count++] = NULL;
854 BUG_ON(count > ARRAY_SIZE(i->rport_attrs));
855
856 transport_container_register(&i->rport_attr_cont);
857
858 i->f = ft;
859
860 return &i->t;
861}
862EXPORT_SYMBOL_GPL(srp_attach_transport);
863
864/**
865 * srp_release_transport - release SRP transport template instance
866 * @t: transport template instance
867 */
868void srp_release_transport(struct scsi_transport_template *t)
869{
870 struct srp_internal *i = to_srp_internal(t);
871
872 transport_container_unregister(&i->t.host_attrs);
873 transport_container_unregister(&i->rport_attr_cont);
874
875 kfree(i);
876}
877EXPORT_SYMBOL_GPL(srp_release_transport);
878
879static __init int srp_transport_init(void)
880{
881 int ret;
882
883 ret = transport_class_register(&srp_host_class);
884 if (ret)
885 return ret;
886 ret = transport_class_register(&srp_rport_class);
887 if (ret)
888 goto unregister_host_class;
889
890 return 0;
891unregister_host_class:
892 transport_class_unregister(&srp_host_class);
893 return ret;
894}
895
896static void __exit srp_transport_exit(void)
897{
898 transport_class_unregister(&srp_host_class);
899 transport_class_unregister(&srp_rport_class);
900}
901
902MODULE_AUTHOR("FUJITA Tomonori");
903MODULE_DESCRIPTION("SRP Transport Attributes");
904MODULE_LICENSE("GPL");
905
906module_init(srp_transport_init);
907module_exit(srp_transport_exit);