Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
[deliverable/linux.git] / drivers / target / tcm_fc / tfc_sess.c
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1/*
2 * Copyright (c) 2010 Cisco Systems, Inc.
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms and conditions of the GNU General Public License,
6 * version 2, as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
11 * more details.
12 *
13 * You should have received a copy of the GNU General Public License along with
14 * this program; if not, write to the Free Software Foundation, Inc.,
15 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
16 */
17
18/* XXX TBD some includes may be extraneous */
19
20#include <linux/module.h>
21#include <linux/moduleparam.h>
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22#include <linux/utsname.h>
23#include <linux/init.h>
24#include <linux/slab.h>
25#include <linux/kthread.h>
26#include <linux/types.h>
27#include <linux/string.h>
28#include <linux/configfs.h>
29#include <linux/ctype.h>
30#include <linux/hash.h>
31#include <linux/rcupdate.h>
32#include <linux/rculist.h>
33#include <linux/kref.h>
34#include <asm/unaligned.h>
35#include <scsi/scsi.h>
36#include <scsi/scsi_host.h>
37#include <scsi/scsi_device.h>
38#include <scsi/scsi_cmnd.h>
39#include <scsi/libfc.h>
40
41#include <target/target_core_base.h>
c4795fb2 42#include <target/target_core_fabric.h>
3699d92a 43#include <target/target_core_configfs.h>
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44#include <target/configfs_macros.h>
45
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46#include "tcm_fc.h"
47
48static void ft_sess_delete_all(struct ft_tport *);
49
50/*
51 * Lookup or allocate target local port.
52 * Caller holds ft_lport_lock.
53 */
54static struct ft_tport *ft_tport_create(struct fc_lport *lport)
55{
56 struct ft_tpg *tpg;
57 struct ft_tport *tport;
58 int i;
59
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60 tport = rcu_dereference_protected(lport->prov[FC_TYPE_FCP],
61 lockdep_is_held(&ft_lport_lock));
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62 if (tport && tport->tpg)
63 return tport;
64
65 tpg = ft_lport_find_tpg(lport);
66 if (!tpg)
67 return NULL;
68
69 if (tport) {
70 tport->tpg = tpg;
71 return tport;
72 }
73
74 tport = kzalloc(sizeof(*tport), GFP_KERNEL);
75 if (!tport)
76 return NULL;
77
78 tport->lport = lport;
79 tport->tpg = tpg;
80 tpg->tport = tport;
81 for (i = 0; i < FT_SESS_HASH_SIZE; i++)
82 INIT_HLIST_HEAD(&tport->hash[i]);
83
84 rcu_assign_pointer(lport->prov[FC_TYPE_FCP], tport);
85 return tport;
86}
87
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88/*
89 * Delete a target local port.
90 * Caller holds ft_lport_lock.
91 */
92static void ft_tport_delete(struct ft_tport *tport)
93{
94 struct fc_lport *lport;
95 struct ft_tpg *tpg;
96
97 ft_sess_delete_all(tport);
98 lport = tport->lport;
99 BUG_ON(tport != lport->prov[FC_TYPE_FCP]);
100 rcu_assign_pointer(lport->prov[FC_TYPE_FCP], NULL);
101
102 tpg = tport->tpg;
103 if (tpg) {
104 tpg->tport = NULL;
105 tport->tpg = NULL;
106 }
a6c76da8 107 kfree_rcu(tport, rcu);
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108}
109
110/*
111 * Add local port.
112 * Called thru fc_lport_iterate().
113 */
114void ft_lport_add(struct fc_lport *lport, void *arg)
115{
116 mutex_lock(&ft_lport_lock);
117 ft_tport_create(lport);
118 mutex_unlock(&ft_lport_lock);
119}
120
121/*
122 * Delete local port.
123 * Called thru fc_lport_iterate().
124 */
125void ft_lport_del(struct fc_lport *lport, void *arg)
126{
127 struct ft_tport *tport;
128
129 mutex_lock(&ft_lport_lock);
130 tport = lport->prov[FC_TYPE_FCP];
131 if (tport)
132 ft_tport_delete(tport);
133 mutex_unlock(&ft_lport_lock);
134}
135
136/*
137 * Notification of local port change from libfc.
138 * Create or delete local port and associated tport.
139 */
140int ft_lport_notify(struct notifier_block *nb, unsigned long event, void *arg)
141{
142 struct fc_lport *lport = arg;
143
144 switch (event) {
145 case FC_LPORT_EV_ADD:
146 ft_lport_add(lport, NULL);
147 break;
148 case FC_LPORT_EV_DEL:
149 ft_lport_del(lport, NULL);
150 break;
151 }
152 return NOTIFY_DONE;
153}
154
155/*
156 * Hash function for FC_IDs.
157 */
158static u32 ft_sess_hash(u32 port_id)
159{
160 return hash_32(port_id, FT_SESS_HASH_BITS);
161}
162
163/*
164 * Find session in local port.
165 * Sessions and hash lists are RCU-protected.
166 * A reference is taken which must be eventually freed.
167 */
168static struct ft_sess *ft_sess_get(struct fc_lport *lport, u32 port_id)
169{
170 struct ft_tport *tport;
171 struct hlist_head *head;
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172 struct ft_sess *sess;
173
174 rcu_read_lock();
175 tport = rcu_dereference(lport->prov[FC_TYPE_FCP]);
176 if (!tport)
177 goto out;
178
179 head = &tport->hash[ft_sess_hash(port_id)];
b67bfe0d 180 hlist_for_each_entry_rcu(sess, head, hash) {
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181 if (sess->port_id == port_id) {
182 kref_get(&sess->kref);
183 rcu_read_unlock();
6708bb27 184 pr_debug("port_id %x found %p\n", port_id, sess);
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185 return sess;
186 }
187 }
188out:
189 rcu_read_unlock();
6708bb27 190 pr_debug("port_id %x not found\n", port_id);
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191 return NULL;
192}
193
194/*
195 * Allocate session and enter it in the hash for the local port.
196 * Caller holds ft_lport_lock.
197 */
198static struct ft_sess *ft_sess_create(struct ft_tport *tport, u32 port_id,
199 struct ft_node_acl *acl)
200{
201 struct ft_sess *sess;
202 struct hlist_head *head;
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203
204 head = &tport->hash[ft_sess_hash(port_id)];
b67bfe0d 205 hlist_for_each_entry_rcu(sess, head, hash)
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206 if (sess->port_id == port_id)
207 return sess;
208
209 sess = kzalloc(sizeof(*sess), GFP_KERNEL);
210 if (!sess)
211 return NULL;
212
213 sess->se_sess = transport_init_session();
552523dc 214 if (IS_ERR(sess->se_sess)) {
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215 kfree(sess);
216 return NULL;
217 }
218 sess->se_sess->se_node_acl = &acl->se_node_acl;
219 sess->tport = tport;
220 sess->port_id = port_id;
221 kref_init(&sess->kref); /* ref for table entry */
222 hlist_add_head_rcu(&sess->hash, head);
223 tport->sess_count++;
224
6708bb27 225 pr_debug("port_id %x sess %p\n", port_id, sess);
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226
227 transport_register_session(&tport->tpg->se_tpg, &acl->se_node_acl,
228 sess->se_sess, sess);
229 return sess;
230}
231
232/*
233 * Unhash the session.
234 * Caller holds ft_lport_lock.
235 */
236static void ft_sess_unhash(struct ft_sess *sess)
237{
238 struct ft_tport *tport = sess->tport;
239
240 hlist_del_rcu(&sess->hash);
241 BUG_ON(!tport->sess_count);
242 tport->sess_count--;
243 sess->port_id = -1;
244 sess->params = 0;
245}
246
247/*
248 * Delete session from hash.
249 * Caller holds ft_lport_lock.
250 */
251static struct ft_sess *ft_sess_delete(struct ft_tport *tport, u32 port_id)
252{
253 struct hlist_head *head;
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254 struct ft_sess *sess;
255
256 head = &tport->hash[ft_sess_hash(port_id)];
b67bfe0d 257 hlist_for_each_entry_rcu(sess, head, hash) {
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258 if (sess->port_id == port_id) {
259 ft_sess_unhash(sess);
260 return sess;
261 }
262 }
263 return NULL;
264}
265
266/*
267 * Delete all sessions from tport.
268 * Caller holds ft_lport_lock.
269 */
270static void ft_sess_delete_all(struct ft_tport *tport)
271{
272 struct hlist_head *head;
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273 struct ft_sess *sess;
274
275 for (head = tport->hash;
276 head < &tport->hash[FT_SESS_HASH_SIZE]; head++) {
b67bfe0d 277 hlist_for_each_entry_rcu(sess, head, hash) {
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278 ft_sess_unhash(sess);
279 transport_deregister_session_configfs(sess->se_sess);
280 ft_sess_put(sess); /* release from table */
281 }
282 }
283}
284
285/*
286 * TCM ops for sessions.
287 */
288
289/*
290 * Determine whether session is allowed to be shutdown in the current context.
291 * Returns non-zero if the session should be shutdown.
292 */
293int ft_sess_shutdown(struct se_session *se_sess)
294{
295 struct ft_sess *sess = se_sess->fabric_sess_ptr;
296
6708bb27 297 pr_debug("port_id %x\n", sess->port_id);
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298 return 1;
299}
300
301/*
302 * Remove session and send PRLO.
303 * This is called when the ACL is being deleted or queue depth is changing.
304 */
305void ft_sess_close(struct se_session *se_sess)
306{
307 struct ft_sess *sess = se_sess->fabric_sess_ptr;
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308 u32 port_id;
309
310 mutex_lock(&ft_lport_lock);
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311 port_id = sess->port_id;
312 if (port_id == -1) {
7c7cf3b9 313 mutex_unlock(&ft_lport_lock);
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314 return;
315 }
6708bb27 316 pr_debug("port_id %x\n", port_id);
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317 ft_sess_unhash(sess);
318 mutex_unlock(&ft_lport_lock);
319 transport_deregister_session_configfs(se_sess);
320 ft_sess_put(sess);
321 /* XXX Send LOGO or PRLO */
322 synchronize_rcu(); /* let transport deregister happen */
323}
324
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325u32 ft_sess_get_index(struct se_session *se_sess)
326{
327 struct ft_sess *sess = se_sess->fabric_sess_ptr;
328
329 return sess->port_id; /* XXX TBD probably not what is needed */
330}
331
332u32 ft_sess_get_port_name(struct se_session *se_sess,
333 unsigned char *buf, u32 len)
334{
335 struct ft_sess *sess = se_sess->fabric_sess_ptr;
336
337 return ft_format_wwn(buf, len, sess->port_name);
338}
339
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340/*
341 * libfc ops involving sessions.
342 */
343
344static int ft_prli_locked(struct fc_rport_priv *rdata, u32 spp_len,
345 const struct fc_els_spp *rspp, struct fc_els_spp *spp)
346{
347 struct ft_tport *tport;
348 struct ft_sess *sess;
349 struct ft_node_acl *acl;
350 u32 fcp_parm;
351
352 tport = ft_tport_create(rdata->local_port);
353 if (!tport)
edec8dfe 354 goto not_target; /* not a target for this local port */
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355
356 acl = ft_acl_get(tport->tpg, rdata);
357 if (!acl)
edec8dfe 358 goto not_target; /* no target for this remote */
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359
360 if (!rspp)
361 goto fill;
362
363 if (rspp->spp_flags & (FC_SPP_OPA_VAL | FC_SPP_RPA_VAL))
364 return FC_SPP_RESP_NO_PA;
365
366 /*
367 * If both target and initiator bits are off, the SPP is invalid.
368 */
369 fcp_parm = ntohl(rspp->spp_params);
370 if (!(fcp_parm & (FCP_SPPF_INIT_FCN | FCP_SPPF_TARG_FCN)))
371 return FC_SPP_RESP_INVL;
372
373 /*
374 * Create session (image pair) only if requested by
375 * EST_IMG_PAIR flag and if the requestor is an initiator.
376 */
377 if (rspp->spp_flags & FC_SPP_EST_IMG_PAIR) {
378 spp->spp_flags |= FC_SPP_EST_IMG_PAIR;
379 if (!(fcp_parm & FCP_SPPF_INIT_FCN))
380 return FC_SPP_RESP_CONF;
381 sess = ft_sess_create(tport, rdata->ids.port_id, acl);
382 if (!sess)
383 return FC_SPP_RESP_RES;
384 if (!sess->params)
385 rdata->prli_count++;
386 sess->params = fcp_parm;
387 sess->port_name = rdata->ids.port_name;
388 sess->max_frame = rdata->maxframe_size;
389
390 /* XXX TBD - clearing actions. unit attn, see 4.10 */
391 }
392
393 /*
394 * OR in our service parameters with other provider (initiator), if any.
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395 */
396fill:
397 fcp_parm = ntohl(spp->spp_params);
f2eeba21 398 fcp_parm &= ~FCP_SPPF_RETRY;
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399 spp->spp_params = htonl(fcp_parm | FCP_SPPF_TARG_FCN);
400 return FC_SPP_RESP_ACK;
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401
402not_target:
403 fcp_parm = ntohl(spp->spp_params);
404 fcp_parm &= ~FCP_SPPF_TARG_FCN;
405 spp->spp_params = htonl(fcp_parm);
406 return 0;
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407}
408
409/**
410 * tcm_fcp_prli() - Handle incoming or outgoing PRLI for the FCP target
411 * @rdata: remote port private
412 * @spp_len: service parameter page length
413 * @rspp: received service parameter page (NULL for outgoing PRLI)
414 * @spp: response service parameter page
415 *
416 * Returns spp response code.
417 */
418static int ft_prli(struct fc_rport_priv *rdata, u32 spp_len,
419 const struct fc_els_spp *rspp, struct fc_els_spp *spp)
420{
421 int ret;
422
423 mutex_lock(&ft_lport_lock);
424 ret = ft_prli_locked(rdata, spp_len, rspp, spp);
425 mutex_unlock(&ft_lport_lock);
6708bb27 426 pr_debug("port_id %x flags %x ret %x\n",
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427 rdata->ids.port_id, rspp ? rspp->spp_flags : 0, ret);
428 return ret;
429}
430
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431static void ft_sess_free(struct kref *kref)
432{
433 struct ft_sess *sess = container_of(kref, struct ft_sess, kref);
434
9f4ad44b 435 transport_deregister_session(sess->se_sess);
a6ad57ef 436 kfree_rcu(sess, rcu);
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437}
438
439void ft_sess_put(struct ft_sess *sess)
440{
441 int sess_held = atomic_read(&sess->kref.refcount);
442
443 BUG_ON(!sess_held);
444 kref_put(&sess->kref, ft_sess_free);
445}
446
447static void ft_prlo(struct fc_rport_priv *rdata)
448{
449 struct ft_sess *sess;
450 struct ft_tport *tport;
451
452 mutex_lock(&ft_lport_lock);
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453 tport = rcu_dereference_protected(rdata->local_port->prov[FC_TYPE_FCP],
454 lockdep_is_held(&ft_lport_lock));
455
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456 if (!tport) {
457 mutex_unlock(&ft_lport_lock);
458 return;
459 }
460 sess = ft_sess_delete(tport, rdata->ids.port_id);
461 if (!sess) {
462 mutex_unlock(&ft_lport_lock);
463 return;
464 }
465 mutex_unlock(&ft_lport_lock);
466 transport_deregister_session_configfs(sess->se_sess);
467 ft_sess_put(sess); /* release from table */
468 rdata->prli_count--;
469 /* XXX TBD - clearing actions. unit attn, see 4.10 */
470}
471
472/*
473 * Handle incoming FCP request.
474 * Caller has verified that the frame is type FCP.
475 */
476static void ft_recv(struct fc_lport *lport, struct fc_frame *fp)
477{
478 struct ft_sess *sess;
479 u32 sid = fc_frame_sid(fp);
480
6708bb27 481 pr_debug("sid %x\n", sid);
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482
483 sess = ft_sess_get(lport, sid);
484 if (!sess) {
6708bb27 485 pr_debug("sid %x sess lookup failed\n", sid);
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486 /* TBD XXX - if FCP_CMND, send PRLO */
487 fc_frame_free(fp);
488 return;
489 }
490 ft_recv_req(sess, fp); /* must do ft_sess_put() */
491}
492
493/*
494 * Provider ops for libfc.
495 */
496struct fc4_prov ft_prov = {
497 .prli = ft_prli,
498 .prlo = ft_prlo,
499 .recv = ft_recv,
500 .module = THIS_MODULE,
501};
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