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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// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * SCSI RDMA (SRP) transport class
4 *
5 * Copyright (C) 2007 FUJITA Tomonori <tomof@acm.org>
6 */
7#include <linux/init.h>
8#include <linux/module.h>
9#include <linux/jiffies.h>
10#include <linux/err.h>
11#include <linux/slab.h>
12#include <linux/string.h>
13
14#include <scsi/scsi.h>
15#include <scsi/scsi_cmnd.h>
16#include <scsi/scsi_device.h>
17#include <scsi/scsi_host.h>
18#include <scsi/scsi_transport.h>
19#include <scsi/scsi_transport_srp.h>
20#include "scsi_priv.h"
21
22struct srp_host_attrs {
23 atomic_t next_port_id;
24};
25#define to_srp_host_attrs(host) ((struct srp_host_attrs *)(host)->shost_data)
26
27#define SRP_HOST_ATTRS 0
28#define SRP_RPORT_ATTRS 8
29
30struct srp_internal {
31 struct scsi_transport_template t;
32 struct srp_function_template *f;
33
34 struct device_attribute *host_attrs[SRP_HOST_ATTRS + 1];
35
36 struct device_attribute *rport_attrs[SRP_RPORT_ATTRS + 1];
37 struct transport_container rport_attr_cont;
38};
39
40static int scsi_is_srp_rport(const struct device *dev);
41
42#define to_srp_internal(tmpl) container_of(tmpl, struct srp_internal, t)
43
44#define dev_to_rport(d) container_of(d, struct srp_rport, dev)
45#define transport_class_to_srp_rport(dev) dev_to_rport((dev)->parent)
46static inline struct Scsi_Host *rport_to_shost(struct srp_rport *r)
47{
48 return dev_to_shost(r->dev.parent);
49}
50
51static int find_child_rport(struct device *dev, void *data)
52{
53 struct device **child = data;
54
55 if (scsi_is_srp_rport(dev)) {
56 WARN_ON_ONCE(*child);
57 *child = dev;
58 }
59 return 0;
60}
61
62static inline struct srp_rport *shost_to_rport(struct Scsi_Host *shost)
63{
64 struct device *child = NULL;
65
66 WARN_ON_ONCE(device_for_each_child(&shost->shost_gendev, &child,
67 find_child_rport) < 0);
68 return child ? dev_to_rport(child) : NULL;
69}
70
71/**
72 * srp_tmo_valid() - check timeout combination validity
73 * @reconnect_delay: Reconnect delay in seconds.
74 * @fast_io_fail_tmo: Fast I/O fail timeout in seconds.
75 * @dev_loss_tmo: Device loss timeout in seconds.
76 *
77 * The combination of the timeout parameters must be such that SCSI commands
78 * are finished in a reasonable time. Hence do not allow the fast I/O fail
79 * timeout to exceed SCSI_DEVICE_BLOCK_MAX_TIMEOUT nor allow dev_loss_tmo to
80 * exceed that limit if failing I/O fast has been disabled. Furthermore, these
81 * parameters must be such that multipath can detect failed paths timely.
82 * Hence do not allow all three parameters to be disabled simultaneously.
83 */
84int srp_tmo_valid(int reconnect_delay, int fast_io_fail_tmo, long dev_loss_tmo)
85{
86 if (reconnect_delay < 0 && fast_io_fail_tmo < 0 && dev_loss_tmo < 0)
87 return -EINVAL;
88 if (reconnect_delay == 0)
89 return -EINVAL;
90 if (fast_io_fail_tmo > SCSI_DEVICE_BLOCK_MAX_TIMEOUT)
91 return -EINVAL;
92 if (fast_io_fail_tmo < 0 &&
93 dev_loss_tmo > SCSI_DEVICE_BLOCK_MAX_TIMEOUT)
94 return -EINVAL;
95 if (dev_loss_tmo >= LONG_MAX / HZ)
96 return -EINVAL;
97 if (fast_io_fail_tmo >= 0 && dev_loss_tmo >= 0 &&
98 fast_io_fail_tmo >= dev_loss_tmo)
99 return -EINVAL;
100 return 0;
101}
102EXPORT_SYMBOL_GPL(srp_tmo_valid);
103
104static int srp_host_setup(struct transport_container *tc, struct device *dev,
105 struct device *cdev)
106{
107 struct Scsi_Host *shost = dev_to_shost(dev);
108 struct srp_host_attrs *srp_host = to_srp_host_attrs(shost);
109
110 atomic_set(&srp_host->next_port_id, 0);
111 return 0;
112}
113
114static DECLARE_TRANSPORT_CLASS(srp_host_class, "srp_host", srp_host_setup,
115 NULL, NULL);
116
117static DECLARE_TRANSPORT_CLASS(srp_rport_class, "srp_remote_ports",
118 NULL, NULL, NULL);
119
120static ssize_t
121show_srp_rport_id(struct device *dev, struct device_attribute *attr,
122 char *buf)
123{
124 struct srp_rport *rport = transport_class_to_srp_rport(dev);
125 return sprintf(buf, "%16phC\n", rport->port_id);
126}
127
128static DEVICE_ATTR(port_id, S_IRUGO, show_srp_rport_id, NULL);
129
130static const struct {
131 u32 value;
132 char *name;
133} srp_rport_role_names[] = {
134 {SRP_RPORT_ROLE_INITIATOR, "SRP Initiator"},
135 {SRP_RPORT_ROLE_TARGET, "SRP Target"},
136};
137
138static ssize_t
139show_srp_rport_roles(struct device *dev, struct device_attribute *attr,
140 char *buf)
141{
142 struct srp_rport *rport = transport_class_to_srp_rport(dev);
143 int i;
144 char *name = NULL;
145
146 for (i = 0; i < ARRAY_SIZE(srp_rport_role_names); i++)
147 if (srp_rport_role_names[i].value == rport->roles) {
148 name = srp_rport_role_names[i].name;
149 break;
150 }
151 return sprintf(buf, "%s\n", name ? : "unknown");
152}
153
154static DEVICE_ATTR(roles, S_IRUGO, show_srp_rport_roles, NULL);
155
156static ssize_t store_srp_rport_delete(struct device *dev,
157 struct device_attribute *attr,
158 const char *buf, size_t count)
159{
160 struct srp_rport *rport = transport_class_to_srp_rport(dev);
161 struct Scsi_Host *shost = dev_to_shost(dev);
162 struct srp_internal *i = to_srp_internal(shost->transportt);
163
164 if (i->f->rport_delete) {
165 i->f->rport_delete(rport);
166 return count;
167 } else {
168 return -ENOSYS;
169 }
170}
171
172static DEVICE_ATTR(delete, S_IWUSR, NULL, store_srp_rport_delete);
173
174static ssize_t show_srp_rport_state(struct device *dev,
175 struct device_attribute *attr,
176 char *buf)
177{
178 static const char *const state_name[] = {
179 [SRP_RPORT_RUNNING] = "running",
180 [SRP_RPORT_BLOCKED] = "blocked",
181 [SRP_RPORT_FAIL_FAST] = "fail-fast",
182 [SRP_RPORT_LOST] = "lost",
183 };
184 struct srp_rport *rport = transport_class_to_srp_rport(dev);
185 enum srp_rport_state state = rport->state;
186
187 return sprintf(buf, "%s\n",
188 (unsigned)state < ARRAY_SIZE(state_name) ?
189 state_name[state] : "???");
190}
191
192static DEVICE_ATTR(state, S_IRUGO, show_srp_rport_state, NULL);
193
194static ssize_t srp_show_tmo(char *buf, int tmo)
195{
196 return tmo >= 0 ? sprintf(buf, "%d\n", tmo) : sprintf(buf, "off\n");
197}
198
199int srp_parse_tmo(int *tmo, const char *buf)
200{
201 int res = 0;
202
203 if (strncmp(buf, "off", 3) != 0)
204 res = kstrtoint(buf, 0, tmo);
205 else
206 *tmo = -1;
207
208 return res;
209}
210EXPORT_SYMBOL(srp_parse_tmo);
211
212static ssize_t show_reconnect_delay(struct device *dev,
213 struct device_attribute *attr, char *buf)
214{
215 struct srp_rport *rport = transport_class_to_srp_rport(dev);
216
217 return srp_show_tmo(buf, rport->reconnect_delay);
218}
219
220static ssize_t store_reconnect_delay(struct device *dev,
221 struct device_attribute *attr,
222 const char *buf, const size_t count)
223{
224 struct srp_rport *rport = transport_class_to_srp_rport(dev);
225 int res, delay;
226
227 res = srp_parse_tmo(&delay, buf);
228 if (res)
229 goto out;
230 res = srp_tmo_valid(delay, rport->fast_io_fail_tmo,
231 rport->dev_loss_tmo);
232 if (res)
233 goto out;
234
235 if (rport->reconnect_delay <= 0 && delay > 0 &&
236 rport->state != SRP_RPORT_RUNNING) {
237 queue_delayed_work(system_long_wq, &rport->reconnect_work,
238 delay * HZ);
239 } else if (delay <= 0) {
240 cancel_delayed_work(&rport->reconnect_work);
241 }
242 rport->reconnect_delay = delay;
243 res = count;
244
245out:
246 return res;
247}
248
249static DEVICE_ATTR(reconnect_delay, S_IRUGO | S_IWUSR, show_reconnect_delay,
250 store_reconnect_delay);
251
252static ssize_t show_failed_reconnects(struct device *dev,
253 struct device_attribute *attr, char *buf)
254{
255 struct srp_rport *rport = transport_class_to_srp_rport(dev);
256
257 return sprintf(buf, "%d\n", rport->failed_reconnects);
258}
259
260static DEVICE_ATTR(failed_reconnects, S_IRUGO, show_failed_reconnects, NULL);
261
262static ssize_t show_srp_rport_fast_io_fail_tmo(struct device *dev,
263 struct device_attribute *attr,
264 char *buf)
265{
266 struct srp_rport *rport = transport_class_to_srp_rport(dev);
267
268 return srp_show_tmo(buf, rport->fast_io_fail_tmo);
269}
270
271static ssize_t store_srp_rport_fast_io_fail_tmo(struct device *dev,
272 struct device_attribute *attr,
273 const char *buf, size_t count)
274{
275 struct srp_rport *rport = transport_class_to_srp_rport(dev);
276 int res;
277 int fast_io_fail_tmo;
278
279 res = srp_parse_tmo(&fast_io_fail_tmo, buf);
280 if (res)
281 goto out;
282 res = srp_tmo_valid(rport->reconnect_delay, fast_io_fail_tmo,
283 rport->dev_loss_tmo);
284 if (res)
285 goto out;
286 rport->fast_io_fail_tmo = fast_io_fail_tmo;
287 res = count;
288
289out:
290 return res;
291}
292
293static DEVICE_ATTR(fast_io_fail_tmo, S_IRUGO | S_IWUSR,
294 show_srp_rport_fast_io_fail_tmo,
295 store_srp_rport_fast_io_fail_tmo);
296
297static ssize_t show_srp_rport_dev_loss_tmo(struct device *dev,
298 struct device_attribute *attr,
299 char *buf)
300{
301 struct srp_rport *rport = transport_class_to_srp_rport(dev);
302
303 return srp_show_tmo(buf, rport->dev_loss_tmo);
304}
305
306static ssize_t store_srp_rport_dev_loss_tmo(struct device *dev,
307 struct device_attribute *attr,
308 const char *buf, size_t count)
309{
310 struct srp_rport *rport = transport_class_to_srp_rport(dev);
311 int res;
312 int dev_loss_tmo;
313
314 res = srp_parse_tmo(&dev_loss_tmo, buf);
315 if (res)
316 goto out;
317 res = srp_tmo_valid(rport->reconnect_delay, rport->fast_io_fail_tmo,
318 dev_loss_tmo);
319 if (res)
320 goto out;
321 rport->dev_loss_tmo = dev_loss_tmo;
322 res = count;
323
324out:
325 return res;
326}
327
328static DEVICE_ATTR(dev_loss_tmo, S_IRUGO | S_IWUSR,
329 show_srp_rport_dev_loss_tmo,
330 store_srp_rport_dev_loss_tmo);
331
332static int srp_rport_set_state(struct srp_rport *rport,
333 enum srp_rport_state new_state)
334{
335 enum srp_rport_state old_state = rport->state;
336
337 lockdep_assert_held(&rport->mutex);
338
339 switch (new_state) {
340 case SRP_RPORT_RUNNING:
341 switch (old_state) {
342 case SRP_RPORT_LOST:
343 goto invalid;
344 default:
345 break;
346 }
347 break;
348 case SRP_RPORT_BLOCKED:
349 switch (old_state) {
350 case SRP_RPORT_RUNNING:
351 break;
352 default:
353 goto invalid;
354 }
355 break;
356 case SRP_RPORT_FAIL_FAST:
357 switch (old_state) {
358 case SRP_RPORT_LOST:
359 goto invalid;
360 default:
361 break;
362 }
363 break;
364 case SRP_RPORT_LOST:
365 break;
366 }
367 rport->state = new_state;
368 return 0;
369
370invalid:
371 return -EINVAL;
372}
373
374/**
375 * srp_reconnect_work() - reconnect and schedule a new attempt if necessary
376 * @work: Work structure used for scheduling this operation.
377 */
378static void srp_reconnect_work(struct work_struct *work)
379{
380 struct srp_rport *rport = container_of(to_delayed_work(work),
381 struct srp_rport, reconnect_work);
382 struct Scsi_Host *shost = rport_to_shost(rport);
383 int delay, res;
384
385 res = srp_reconnect_rport(rport);
386 if (res != 0) {
387 shost_printk(KERN_ERR, shost,
388 "reconnect attempt %d failed (%d)\n",
389 ++rport->failed_reconnects, res);
390 delay = rport->reconnect_delay *
391 min(100, max(1, rport->failed_reconnects - 10));
392 if (delay > 0)
393 queue_delayed_work(system_long_wq,
394 &rport->reconnect_work, delay * HZ);
395 }
396}
397
398static void __rport_fail_io_fast(struct srp_rport *rport)
399{
400 struct Scsi_Host *shost = rport_to_shost(rport);
401 struct srp_internal *i;
402
403 lockdep_assert_held(&rport->mutex);
404
405 if (srp_rport_set_state(rport, SRP_RPORT_FAIL_FAST))
406 return;
407 /*
408 * Call scsi_target_block() to wait for ongoing shost->queuecommand()
409 * calls before invoking i->f->terminate_rport_io().
410 */
411 scsi_target_block(rport->dev.parent);
412 scsi_target_unblock(rport->dev.parent, SDEV_TRANSPORT_OFFLINE);
413
414 /* Involve the LLD if possible to terminate all I/O on the rport. */
415 i = to_srp_internal(shost->transportt);
416 if (i->f->terminate_rport_io)
417 i->f->terminate_rport_io(rport);
418}
419
420/**
421 * rport_fast_io_fail_timedout() - fast I/O failure timeout handler
422 * @work: Work structure used for scheduling this operation.
423 */
424static void rport_fast_io_fail_timedout(struct work_struct *work)
425{
426 struct srp_rport *rport = container_of(to_delayed_work(work),
427 struct srp_rport, fast_io_fail_work);
428 struct Scsi_Host *shost = rport_to_shost(rport);
429
430 pr_info("fast_io_fail_tmo expired for SRP %s / %s.\n",
431 dev_name(&rport->dev), dev_name(&shost->shost_gendev));
432
433 mutex_lock(&rport->mutex);
434 if (rport->state == SRP_RPORT_BLOCKED)
435 __rport_fail_io_fast(rport);
436 mutex_unlock(&rport->mutex);
437}
438
439/**
440 * rport_dev_loss_timedout() - device loss timeout handler
441 * @work: Work structure used for scheduling this operation.
442 */
443static void rport_dev_loss_timedout(struct work_struct *work)
444{
445 struct srp_rport *rport = container_of(to_delayed_work(work),
446 struct srp_rport, dev_loss_work);
447 struct Scsi_Host *shost = rport_to_shost(rport);
448 struct srp_internal *i = to_srp_internal(shost->transportt);
449
450 pr_info("dev_loss_tmo expired for SRP %s / %s.\n",
451 dev_name(&rport->dev), dev_name(&shost->shost_gendev));
452
453 mutex_lock(&rport->mutex);
454 WARN_ON(srp_rport_set_state(rport, SRP_RPORT_LOST) != 0);
455 scsi_target_unblock(rport->dev.parent, SDEV_TRANSPORT_OFFLINE);
456 mutex_unlock(&rport->mutex);
457
458 i->f->rport_delete(rport);
459}
460
461static void __srp_start_tl_fail_timers(struct srp_rport *rport)
462{
463 struct Scsi_Host *shost = rport_to_shost(rport);
464 int delay, fast_io_fail_tmo, dev_loss_tmo;
465
466 lockdep_assert_held(&rport->mutex);
467
468 delay = rport->reconnect_delay;
469 fast_io_fail_tmo = rport->fast_io_fail_tmo;
470 dev_loss_tmo = rport->dev_loss_tmo;
471 pr_debug("%s current state: %d\n", dev_name(&shost->shost_gendev),
472 rport->state);
473
474 if (rport->state == SRP_RPORT_LOST)
475 return;
476 if (delay > 0)
477 queue_delayed_work(system_long_wq, &rport->reconnect_work,
478 1UL * delay * HZ);
479 if ((fast_io_fail_tmo >= 0 || dev_loss_tmo >= 0) &&
480 srp_rport_set_state(rport, SRP_RPORT_BLOCKED) == 0) {
481 pr_debug("%s new state: %d\n", dev_name(&shost->shost_gendev),
482 rport->state);
483 scsi_target_block(&shost->shost_gendev);
484 if (fast_io_fail_tmo >= 0)
485 queue_delayed_work(system_long_wq,
486 &rport->fast_io_fail_work,
487 1UL * fast_io_fail_tmo * HZ);
488 if (dev_loss_tmo >= 0)
489 queue_delayed_work(system_long_wq,
490 &rport->dev_loss_work,
491 1UL * dev_loss_tmo * HZ);
492 }
493}
494
495/**
496 * srp_start_tl_fail_timers() - start the transport layer failure timers
497 * @rport: SRP target port.
498 *
499 * Start the transport layer fast I/O failure and device loss timers. Do not
500 * modify a timer that was already started.
501 */
502void srp_start_tl_fail_timers(struct srp_rport *rport)
503{
504 mutex_lock(&rport->mutex);
505 __srp_start_tl_fail_timers(rport);
506 mutex_unlock(&rport->mutex);
507}
508EXPORT_SYMBOL(srp_start_tl_fail_timers);
509
510/**
511 * srp_reconnect_rport() - reconnect to an SRP target port
512 * @rport: SRP target port.
513 *
514 * Blocks SCSI command queueing before invoking reconnect() such that
515 * queuecommand() won't be invoked concurrently with reconnect() from outside
516 * the SCSI EH. This is important since a reconnect() implementation may
517 * reallocate resources needed by queuecommand().
518 *
519 * Notes:
520 * - This function neither waits until outstanding requests have finished nor
521 * tries to abort these. It is the responsibility of the reconnect()
522 * function to finish outstanding commands before reconnecting to the target
523 * port.
524 * - It is the responsibility of the caller to ensure that the resources
525 * reallocated by the reconnect() function won't be used while this function
526 * is in progress. One possible strategy is to invoke this function from
527 * the context of the SCSI EH thread only. Another possible strategy is to
528 * lock the rport mutex inside each SCSI LLD callback that can be invoked by
529 * the SCSI EH (the scsi_host_template.eh_*() functions and also the
530 * scsi_host_template.queuecommand() function).
531 */
532int srp_reconnect_rport(struct srp_rport *rport)
533{
534 struct Scsi_Host *shost = rport_to_shost(rport);
535 struct srp_internal *i = to_srp_internal(shost->transportt);
536 struct scsi_device *sdev;
537 int res;
538
539 pr_debug("SCSI host %s\n", dev_name(&shost->shost_gendev));
540
541 res = mutex_lock_interruptible(&rport->mutex);
542 if (res)
543 goto out;
544 scsi_target_block(&shost->shost_gendev);
545 res = rport->state != SRP_RPORT_LOST ? i->f->reconnect(rport) : -ENODEV;
546 pr_debug("%s (state %d): transport.reconnect() returned %d\n",
547 dev_name(&shost->shost_gendev), rport->state, res);
548 if (res == 0) {
549 cancel_delayed_work(&rport->fast_io_fail_work);
550 cancel_delayed_work(&rport->dev_loss_work);
551
552 rport->failed_reconnects = 0;
553 srp_rport_set_state(rport, SRP_RPORT_RUNNING);
554 scsi_target_unblock(&shost->shost_gendev, SDEV_RUNNING);
555 /*
556 * If the SCSI error handler has offlined one or more devices,
557 * invoking scsi_target_unblock() won't change the state of
558 * these devices into running so do that explicitly.
559 */
560 shost_for_each_device(sdev, shost) {
561 mutex_lock(&sdev->state_mutex);
562 if (sdev->sdev_state == SDEV_OFFLINE)
563 sdev->sdev_state = SDEV_RUNNING;
564 mutex_unlock(&sdev->state_mutex);
565 }
566 } else if (rport->state == SRP_RPORT_RUNNING) {
567 /*
568 * srp_reconnect_rport() has been invoked with fast_io_fail
569 * and dev_loss off. Mark the port as failed and start the TL
570 * failure timers if these had not yet been started.
571 */
572 __rport_fail_io_fast(rport);
573 scsi_target_unblock(&shost->shost_gendev,
574 SDEV_TRANSPORT_OFFLINE);
575 __srp_start_tl_fail_timers(rport);
576 } else if (rport->state != SRP_RPORT_BLOCKED) {
577 scsi_target_unblock(&shost->shost_gendev,
578 SDEV_TRANSPORT_OFFLINE);
579 }
580 mutex_unlock(&rport->mutex);
581
582out:
583 return res;
584}
585EXPORT_SYMBOL(srp_reconnect_rport);
586
587/**
588 * srp_timed_out() - SRP transport intercept of the SCSI timeout EH
589 * @scmd: SCSI command.
590 *
591 * If a timeout occurs while an rport is in the blocked state, ask the SCSI
592 * EH to continue waiting (BLK_EH_RESET_TIMER). Otherwise let the SCSI core
593 * handle the timeout (BLK_EH_DONE).
594 *
595 * Note: This function is called from soft-IRQ context and with the request
596 * queue lock held.
597 */
598enum blk_eh_timer_return srp_timed_out(struct scsi_cmnd *scmd)
599{
600 struct scsi_device *sdev = scmd->device;
601 struct Scsi_Host *shost = sdev->host;
602 struct srp_internal *i = to_srp_internal(shost->transportt);
603 struct srp_rport *rport = shost_to_rport(shost);
604
605 pr_debug("timeout for sdev %s\n", dev_name(&sdev->sdev_gendev));
606 return rport && rport->fast_io_fail_tmo < 0 &&
607 rport->dev_loss_tmo < 0 &&
608 i->f->reset_timer_if_blocked && scsi_device_blocked(sdev) ?
609 BLK_EH_RESET_TIMER : BLK_EH_DONE;
610}
611EXPORT_SYMBOL(srp_timed_out);
612
613static void srp_rport_release(struct device *dev)
614{
615 struct srp_rport *rport = dev_to_rport(dev);
616
617 put_device(dev->parent);
618 kfree(rport);
619}
620
621static int scsi_is_srp_rport(const struct device *dev)
622{
623 return dev->release == srp_rport_release;
624}
625
626static int srp_rport_match(struct attribute_container *cont,
627 struct device *dev)
628{
629 struct Scsi_Host *shost;
630 struct srp_internal *i;
631
632 if (!scsi_is_srp_rport(dev))
633 return 0;
634
635 shost = dev_to_shost(dev->parent);
636 if (!shost->transportt)
637 return 0;
638 if (shost->transportt->host_attrs.ac.class != &srp_host_class.class)
639 return 0;
640
641 i = to_srp_internal(shost->transportt);
642 return &i->rport_attr_cont.ac == cont;
643}
644
645static int srp_host_match(struct attribute_container *cont, struct device *dev)
646{
647 struct Scsi_Host *shost;
648 struct srp_internal *i;
649
650 if (!scsi_is_host_device(dev))
651 return 0;
652
653 shost = dev_to_shost(dev);
654 if (!shost->transportt)
655 return 0;
656 if (shost->transportt->host_attrs.ac.class != &srp_host_class.class)
657 return 0;
658
659 i = to_srp_internal(shost->transportt);
660 return &i->t.host_attrs.ac == cont;
661}
662
663/**
664 * srp_rport_get() - increment rport reference count
665 * @rport: SRP target port.
666 */
667void srp_rport_get(struct srp_rport *rport)
668{
669 get_device(&rport->dev);
670}
671EXPORT_SYMBOL(srp_rport_get);
672
673/**
674 * srp_rport_put() - decrement rport reference count
675 * @rport: SRP target port.
676 */
677void srp_rport_put(struct srp_rport *rport)
678{
679 put_device(&rport->dev);
680}
681EXPORT_SYMBOL(srp_rport_put);
682
683/**
684 * srp_rport_add - add a SRP remote port to the device hierarchy
685 * @shost: scsi host the remote port is connected to.
686 * @ids: The port id for the remote port.
687 *
688 * Publishes a port to the rest of the system.
689 */
690struct srp_rport *srp_rport_add(struct Scsi_Host *shost,
691 struct srp_rport_identifiers *ids)
692{
693 struct srp_rport *rport;
694 struct device *parent = &shost->shost_gendev;
695 struct srp_internal *i = to_srp_internal(shost->transportt);
696 int id, ret;
697
698 rport = kzalloc(sizeof(*rport), GFP_KERNEL);
699 if (!rport)
700 return ERR_PTR(-ENOMEM);
701
702 mutex_init(&rport->mutex);
703
704 device_initialize(&rport->dev);
705
706 rport->dev.parent = get_device(parent);
707 rport->dev.release = srp_rport_release;
708
709 memcpy(rport->port_id, ids->port_id, sizeof(rport->port_id));
710 rport->roles = ids->roles;
711
712 if (i->f->reconnect)
713 rport->reconnect_delay = i->f->reconnect_delay ?
714 *i->f->reconnect_delay : 10;
715 INIT_DELAYED_WORK(&rport->reconnect_work, srp_reconnect_work);
716 rport->fast_io_fail_tmo = i->f->fast_io_fail_tmo ?
717 *i->f->fast_io_fail_tmo : 15;
718 rport->dev_loss_tmo = i->f->dev_loss_tmo ? *i->f->dev_loss_tmo : 60;
719 INIT_DELAYED_WORK(&rport->fast_io_fail_work,
720 rport_fast_io_fail_timedout);
721 INIT_DELAYED_WORK(&rport->dev_loss_work, rport_dev_loss_timedout);
722
723 id = atomic_inc_return(&to_srp_host_attrs(shost)->next_port_id);
724 dev_set_name(&rport->dev, "port-%d:%d", shost->host_no, id);
725
726 transport_setup_device(&rport->dev);
727
728 ret = device_add(&rport->dev);
729 if (ret) {
730 transport_destroy_device(&rport->dev);
731 put_device(&rport->dev);
732 return ERR_PTR(ret);
733 }
734
735 transport_add_device(&rport->dev);
736 transport_configure_device(&rport->dev);
737
738 return rport;
739}
740EXPORT_SYMBOL_GPL(srp_rport_add);
741
742/**
743 * srp_rport_del - remove a SRP remote port
744 * @rport: SRP remote port to remove
745 *
746 * Removes the specified SRP remote port.
747 */
748void srp_rport_del(struct srp_rport *rport)
749{
750 struct device *dev = &rport->dev;
751
752 transport_remove_device(dev);
753 device_del(dev);
754 transport_destroy_device(dev);
755
756 put_device(dev);
757}
758EXPORT_SYMBOL_GPL(srp_rport_del);
759
760static int do_srp_rport_del(struct device *dev, void *data)
761{
762 if (scsi_is_srp_rport(dev))
763 srp_rport_del(dev_to_rport(dev));
764 return 0;
765}
766
767/**
768 * srp_remove_host - tear down a Scsi_Host's SRP data structures
769 * @shost: Scsi Host that is torn down
770 *
771 * Removes all SRP remote ports for a given Scsi_Host.
772 * Must be called just before scsi_remove_host for SRP HBAs.
773 */
774void srp_remove_host(struct Scsi_Host *shost)
775{
776 device_for_each_child(&shost->shost_gendev, NULL, do_srp_rport_del);
777}
778EXPORT_SYMBOL_GPL(srp_remove_host);
779
780/**
781 * srp_stop_rport_timers - stop the transport layer recovery timers
782 * @rport: SRP remote port for which to stop the timers.
783 *
784 * Must be called after srp_remove_host() and scsi_remove_host(). The caller
785 * must hold a reference on the rport (rport->dev) and on the SCSI host
786 * (rport->dev.parent).
787 */
788void srp_stop_rport_timers(struct srp_rport *rport)
789{
790 mutex_lock(&rport->mutex);
791 if (rport->state == SRP_RPORT_BLOCKED)
792 __rport_fail_io_fast(rport);
793 srp_rport_set_state(rport, SRP_RPORT_LOST);
794 mutex_unlock(&rport->mutex);
795
796 cancel_delayed_work_sync(&rport->reconnect_work);
797 cancel_delayed_work_sync(&rport->fast_io_fail_work);
798 cancel_delayed_work_sync(&rport->dev_loss_work);
799}
800EXPORT_SYMBOL_GPL(srp_stop_rport_timers);
801
802/**
803 * srp_attach_transport - instantiate SRP transport template
804 * @ft: SRP transport class function template
805 */
806struct scsi_transport_template *
807srp_attach_transport(struct srp_function_template *ft)
808{
809 int count;
810 struct srp_internal *i;
811
812 i = kzalloc(sizeof(*i), GFP_KERNEL);
813 if (!i)
814 return NULL;
815
816 i->t.host_size = sizeof(struct srp_host_attrs);
817 i->t.host_attrs.ac.attrs = &i->host_attrs[0];
818 i->t.host_attrs.ac.class = &srp_host_class.class;
819 i->t.host_attrs.ac.match = srp_host_match;
820 i->host_attrs[0] = NULL;
821 transport_container_register(&i->t.host_attrs);
822
823 i->rport_attr_cont.ac.attrs = &i->rport_attrs[0];
824 i->rport_attr_cont.ac.class = &srp_rport_class.class;
825 i->rport_attr_cont.ac.match = srp_rport_match;
826
827 count = 0;
828 i->rport_attrs[count++] = &dev_attr_port_id;
829 i->rport_attrs[count++] = &dev_attr_roles;
830 if (ft->has_rport_state) {
831 i->rport_attrs[count++] = &dev_attr_state;
832 i->rport_attrs[count++] = &dev_attr_fast_io_fail_tmo;
833 i->rport_attrs[count++] = &dev_attr_dev_loss_tmo;
834 }
835 if (ft->reconnect) {
836 i->rport_attrs[count++] = &dev_attr_reconnect_delay;
837 i->rport_attrs[count++] = &dev_attr_failed_reconnects;
838 }
839 if (ft->rport_delete)
840 i->rport_attrs[count++] = &dev_attr_delete;
841 i->rport_attrs[count++] = NULL;
842 BUG_ON(count > ARRAY_SIZE(i->rport_attrs));
843
844 transport_container_register(&i->rport_attr_cont);
845
846 i->f = ft;
847
848 return &i->t;
849}
850EXPORT_SYMBOL_GPL(srp_attach_transport);
851
852/**
853 * srp_release_transport - release SRP transport template instance
854 * @t: transport template instance
855 */
856void srp_release_transport(struct scsi_transport_template *t)
857{
858 struct srp_internal *i = to_srp_internal(t);
859
860 transport_container_unregister(&i->t.host_attrs);
861 transport_container_unregister(&i->rport_attr_cont);
862
863 kfree(i);
864}
865EXPORT_SYMBOL_GPL(srp_release_transport);
866
867static __init int srp_transport_init(void)
868{
869 int ret;
870
871 ret = transport_class_register(&srp_host_class);
872 if (ret)
873 return ret;
874 ret = transport_class_register(&srp_rport_class);
875 if (ret)
876 goto unregister_host_class;
877
878 return 0;
879unregister_host_class:
880 transport_class_unregister(&srp_host_class);
881 return ret;
882}
883
884static void __exit srp_transport_exit(void)
885{
886 transport_class_unregister(&srp_host_class);
887 transport_class_unregister(&srp_rport_class);
888}
889
890MODULE_AUTHOR("FUJITA Tomonori");
891MODULE_DESCRIPTION("SRP Transport Attributes");
892MODULE_LICENSE("GPL");
893
894module_init(srp_transport_init);
895module_exit(srp_transport_exit);