217e29df62977559d1886320ea54c6dbe7d04fab
[linux-2.6.git] / drivers / target / target_core_tmr.c
1 /*******************************************************************************
2  * Filename:  target_core_tmr.c
3  *
4  * This file contains SPC-3 task management infrastructure
5  *
6  * Copyright (c) 2009,2010 Rising Tide Systems
7  * Copyright (c) 2009,2010 Linux-iSCSI.org
8  *
9  * Nicholas A. Bellinger <nab@kernel.org>
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation; either version 2 of the License, or
14  * (at your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19  * GNU General Public License for more details.
20  *
21  * You should have received a copy of the GNU General Public License
22  * along with this program; if not, write to the Free Software
23  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
24  *
25  ******************************************************************************/
26
27 #include <linux/slab.h>
28 #include <linux/spinlock.h>
29 #include <linux/list.h>
30 #include <linux/export.h>
31 #include <scsi/scsi.h>
32 #include <scsi/scsi_cmnd.h>
33
34 #include <target/target_core_base.h>
35 #include <target/target_core_device.h>
36 #include <target/target_core_tmr.h>
37 #include <target/target_core_transport.h>
38 #include <target/target_core_fabric_ops.h>
39 #include <target/target_core_configfs.h>
40
41 #include "target_core_alua.h"
42 #include "target_core_pr.h"
43
44 struct se_tmr_req *core_tmr_alloc_req(
45         struct se_cmd *se_cmd,
46         void *fabric_tmr_ptr,
47         u8 function,
48         gfp_t gfp_flags)
49 {
50         struct se_tmr_req *tmr;
51
52         tmr = kmem_cache_zalloc(se_tmr_req_cache, gfp_flags);
53         if (!tmr) {
54                 pr_err("Unable to allocate struct se_tmr_req\n");
55                 return ERR_PTR(-ENOMEM);
56         }
57         tmr->task_cmd = se_cmd;
58         tmr->fabric_tmr_ptr = fabric_tmr_ptr;
59         tmr->function = function;
60         INIT_LIST_HEAD(&tmr->tmr_list);
61
62         return tmr;
63 }
64 EXPORT_SYMBOL(core_tmr_alloc_req);
65
66 void core_tmr_release_req(
67         struct se_tmr_req *tmr)
68 {
69         struct se_device *dev = tmr->tmr_dev;
70         unsigned long flags;
71
72         if (!dev) {
73                 kmem_cache_free(se_tmr_req_cache, tmr);
74                 return;
75         }
76
77         spin_lock_irqsave(&dev->se_tmr_lock, flags);
78         list_del(&tmr->tmr_list);
79         spin_unlock_irqrestore(&dev->se_tmr_lock, flags);
80
81         kmem_cache_free(se_tmr_req_cache, tmr);
82 }
83
84 static void core_tmr_handle_tas_abort(
85         struct se_node_acl *tmr_nacl,
86         struct se_cmd *cmd,
87         int tas,
88         int fe_count)
89 {
90         if (!fe_count) {
91                 transport_cmd_finish_abort(cmd, 1);
92                 return;
93         }
94         /*
95          * TASK ABORTED status (TAS) bit support
96         */
97         if ((tmr_nacl &&
98              (tmr_nacl == cmd->se_sess->se_node_acl)) || tas)
99                 transport_send_task_abort(cmd);
100
101         transport_cmd_finish_abort(cmd, 0);
102 }
103
104 static void core_tmr_drain_tmr_list(
105         struct se_device *dev,
106         struct se_tmr_req *tmr,
107         struct list_head *preempt_and_abort_list)
108 {
109         LIST_HEAD(drain_tmr_list);
110         struct se_tmr_req *tmr_p, *tmr_pp;
111         struct se_cmd *cmd;
112         unsigned long flags;
113         /*
114          * Release all pending and outgoing TMRs aside from the received
115          * LUN_RESET tmr..
116          */
117         spin_lock_irqsave(&dev->se_tmr_lock, flags);
118         list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) {
119                 /*
120                  * Allow the received TMR to return with FUNCTION_COMPLETE.
121                  */
122                 if (tmr_p == tmr)
123                         continue;
124
125                 cmd = tmr_p->task_cmd;
126                 if (!cmd) {
127                         pr_err("Unable to locate struct se_cmd for TMR\n");
128                         continue;
129                 }
130                 /*
131                  * If this function was called with a valid pr_res_key
132                  * parameter (eg: for PROUT PREEMPT_AND_ABORT service action
133                  * skip non regisration key matching TMRs.
134                  */
135                 if (preempt_and_abort_list &&
136                     (core_scsi3_check_cdb_abort_and_preempt(
137                                         preempt_and_abort_list, cmd) != 0))
138                         continue;
139
140                 spin_lock(&cmd->t_state_lock);
141                 if (!atomic_read(&cmd->t_transport_active)) {
142                         spin_unlock(&cmd->t_state_lock);
143                         continue;
144                 }
145                 if (cmd->t_state == TRANSPORT_ISTATE_PROCESSING) {
146                         spin_unlock(&cmd->t_state_lock);
147                         continue;
148                 }
149                 spin_unlock(&cmd->t_state_lock);
150
151                 list_move_tail(&tmr_p->tmr_list, &drain_tmr_list);
152         }
153         spin_unlock_irqrestore(&dev->se_tmr_lock, flags);
154
155         list_for_each_entry_safe(tmr_p, tmr_pp, &drain_tmr_list, tmr_list) {
156                 list_del_init(&tmr_p->tmr_list);
157                 cmd = tmr_p->task_cmd;
158
159                 pr_debug("LUN_RESET: %s releasing TMR %p Function: 0x%02x,"
160                         " Response: 0x%02x, t_state: %d\n",
161                         (preempt_and_abort_list) ? "Preempt" : "", tmr_p,
162                         tmr_p->function, tmr_p->response, cmd->t_state);
163
164                 transport_cmd_finish_abort(cmd, 1);
165         }
166 }
167
168 static void core_tmr_drain_task_list(
169         struct se_device *dev,
170         struct se_cmd *prout_cmd,
171         struct se_node_acl *tmr_nacl,
172         int tas,
173         struct list_head *preempt_and_abort_list)
174 {
175         LIST_HEAD(drain_task_list);
176         struct se_cmd *cmd;
177         struct se_task *task, *task_tmp;
178         unsigned long flags;
179         int fe_count;
180         /*
181          * Complete outstanding struct se_task CDBs with TASK_ABORTED SAM status.
182          * This is following sam4r17, section 5.6 Aborting commands, Table 38
183          * for TMR LUN_RESET:
184          *
185          * a) "Yes" indicates that each command that is aborted on an I_T nexus
186          * other than the one that caused the SCSI device condition is
187          * completed with TASK ABORTED status, if the TAS bit is set to one in
188          * the Control mode page (see SPC-4). "No" indicates that no status is
189          * returned for aborted commands.
190          *
191          * d) If the logical unit reset is caused by a particular I_T nexus
192          * (e.g., by a LOGICAL UNIT RESET task management function), then "yes"
193          * (TASK_ABORTED status) applies.
194          *
195          * Otherwise (e.g., if triggered by a hard reset), "no"
196          * (no TASK_ABORTED SAM status) applies.
197          *
198          * Note that this seems to be independent of TAS (Task Aborted Status)
199          * in the Control Mode Page.
200          */
201         spin_lock_irqsave(&dev->execute_task_lock, flags);
202         list_for_each_entry_safe(task, task_tmp, &dev->state_task_list,
203                                 t_state_list) {
204                 if (!task->task_se_cmd) {
205                         pr_err("task->task_se_cmd is NULL!\n");
206                         continue;
207                 }
208                 cmd = task->task_se_cmd;
209
210                 /*
211                  * For PREEMPT_AND_ABORT usage, only process commands
212                  * with a matching reservation key.
213                  */
214                 if (preempt_and_abort_list &&
215                     (core_scsi3_check_cdb_abort_and_preempt(
216                                         preempt_and_abort_list, cmd) != 0))
217                         continue;
218                 /*
219                  * Not aborting PROUT PREEMPT_AND_ABORT CDB..
220                  */
221                 if (prout_cmd == cmd)
222                         continue;
223
224                 list_move_tail(&task->t_state_list, &drain_task_list);
225                 atomic_set(&task->task_state_active, 0);
226                 /*
227                  * Remove from task execute list before processing drain_task_list
228                  */
229                 if (!list_empty(&task->t_execute_list))
230                         __transport_remove_task_from_execute_queue(task, dev);
231         }
232         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
233
234         while (!list_empty(&drain_task_list)) {
235                 task = list_entry(drain_task_list.next, struct se_task, t_state_list);
236                 list_del(&task->t_state_list);
237                 cmd = task->task_se_cmd;
238
239                 pr_debug("LUN_RESET: %s cmd: %p task: %p"
240                         " ITT/CmdSN: 0x%08x/0x%08x, i_state: %d, t_state: %d"
241                         "cdb: 0x%02x\n",
242                         (preempt_and_abort_list) ? "Preempt" : "", cmd, task,
243                         cmd->se_tfo->get_task_tag(cmd), 0,
244                         cmd->se_tfo->get_cmd_state(cmd), cmd->t_state,
245                         cmd->t_task_cdb[0]);
246                 pr_debug("LUN_RESET: ITT[0x%08x] - pr_res_key: 0x%016Lx"
247                         " t_task_cdbs: %d t_task_cdbs_left: %d"
248                         " t_task_cdbs_sent: %d -- t_transport_active: %d"
249                         " t_transport_stop: %d t_transport_sent: %d\n",
250                         cmd->se_tfo->get_task_tag(cmd), cmd->pr_res_key,
251                         cmd->t_task_list_num,
252                         atomic_read(&cmd->t_task_cdbs_left),
253                         atomic_read(&cmd->t_task_cdbs_sent),
254                         atomic_read(&cmd->t_transport_active),
255                         atomic_read(&cmd->t_transport_stop),
256                         atomic_read(&cmd->t_transport_sent));
257
258                 /*
259                  * If the command may be queued onto a workqueue cancel it now.
260                  *
261                  * This is equivalent to removal from the execute queue in the
262                  * loop above, but we do it down here given that
263                  * cancel_work_sync may block.
264                  */
265                 if (cmd->t_state == TRANSPORT_COMPLETE)
266                         cancel_work_sync(&cmd->work);
267
268                 spin_lock_irqsave(&cmd->t_state_lock, flags);
269                 target_stop_task(task, &flags);
270
271                 if (!atomic_dec_and_test(&cmd->t_task_cdbs_ex_left)) {
272                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
273                         pr_debug("LUN_RESET: Skipping task: %p, dev: %p for"
274                                 " t_task_cdbs_ex_left: %d\n", task, dev,
275                                 atomic_read(&cmd->t_task_cdbs_ex_left));
276                         continue;
277                 }
278                 fe_count = atomic_read(&cmd->t_fe_count);
279
280                 if (atomic_read(&cmd->t_transport_active)) {
281                         pr_debug("LUN_RESET: got t_transport_active = 1 for"
282                                 " task: %p, t_fe_count: %d dev: %p\n", task,
283                                 fe_count, dev);
284                         atomic_set(&cmd->t_transport_aborted, 1);
285                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
286
287                         core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
288                         continue;
289                 }
290                 pr_debug("LUN_RESET: Got t_transport_active = 0 for task: %p,"
291                         " t_fe_count: %d dev: %p\n", task, fe_count, dev);
292                 atomic_set(&cmd->t_transport_aborted, 1);
293                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
294
295                 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
296         }
297 }
298
299 static void core_tmr_drain_cmd_list(
300         struct se_device *dev,
301         struct se_cmd *prout_cmd,
302         struct se_node_acl *tmr_nacl,
303         int tas,
304         struct list_head *preempt_and_abort_list)
305 {
306         LIST_HEAD(drain_cmd_list);
307         struct se_queue_obj *qobj = &dev->dev_queue_obj;
308         struct se_cmd *cmd, *tcmd;
309         unsigned long flags;
310         /*
311          * Release all commands remaining in the struct se_device cmd queue.
312          *
313          * This follows the same logic as above for the struct se_device
314          * struct se_task state list, where commands are returned with
315          * TASK_ABORTED status, if there is an outstanding $FABRIC_MOD
316          * reference, otherwise the struct se_cmd is released.
317          */
318         spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
319         list_for_each_entry_safe(cmd, tcmd, &qobj->qobj_list, se_queue_node) {
320                 /*
321                  * For PREEMPT_AND_ABORT usage, only process commands
322                  * with a matching reservation key.
323                  */
324                 if (preempt_and_abort_list &&
325                     (core_scsi3_check_cdb_abort_and_preempt(
326                                         preempt_and_abort_list, cmd) != 0))
327                         continue;
328                 /*
329                  * Not aborting PROUT PREEMPT_AND_ABORT CDB..
330                  */
331                 if (prout_cmd == cmd)
332                         continue;
333
334                 atomic_set(&cmd->t_transport_queue_active, 0);
335                 atomic_dec(&qobj->queue_cnt);
336                 list_move_tail(&cmd->se_queue_node, &drain_cmd_list);
337         }
338         spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
339
340         while (!list_empty(&drain_cmd_list)) {
341                 cmd = list_entry(drain_cmd_list.next, struct se_cmd, se_queue_node);
342                 list_del_init(&cmd->se_queue_node);
343
344                 pr_debug("LUN_RESET: %s from Device Queue: cmd: %p t_state:"
345                         " %d t_fe_count: %d\n", (preempt_and_abort_list) ?
346                         "Preempt" : "", cmd, cmd->t_state,
347                         atomic_read(&cmd->t_fe_count));
348                 /*
349                  * Signal that the command has failed via cmd->se_cmd_flags,
350                  */
351                 transport_new_cmd_failure(cmd);
352
353                 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas,
354                                 atomic_read(&cmd->t_fe_count));
355         }
356 }
357
358 int core_tmr_lun_reset(
359         struct se_device *dev,
360         struct se_tmr_req *tmr,
361         struct list_head *preempt_and_abort_list,
362         struct se_cmd *prout_cmd)
363 {
364         struct se_node_acl *tmr_nacl = NULL;
365         struct se_portal_group *tmr_tpg = NULL;
366         int tas;
367         /*
368          * TASK_ABORTED status bit, this is configurable via ConfigFS
369          * struct se_device attributes.  spc4r17 section 7.4.6 Control mode page
370          *
371          * A task aborted status (TAS) bit set to zero specifies that aborted
372          * tasks shall be terminated by the device server without any response
373          * to the application client. A TAS bit set to one specifies that tasks
374          * aborted by the actions of an I_T nexus other than the I_T nexus on
375          * which the command was received shall be completed with TASK ABORTED
376          * status (see SAM-4).
377          */
378         tas = dev->se_sub_dev->se_dev_attrib.emulate_tas;
379         /*
380          * Determine if this se_tmr is coming from a $FABRIC_MOD
381          * or struct se_device passthrough..
382          */
383         if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) {
384                 tmr_nacl = tmr->task_cmd->se_sess->se_node_acl;
385                 tmr_tpg = tmr->task_cmd->se_sess->se_tpg;
386                 if (tmr_nacl && tmr_tpg) {
387                         pr_debug("LUN_RESET: TMR caller fabric: %s"
388                                 " initiator port %s\n",
389                                 tmr_tpg->se_tpg_tfo->get_fabric_name(),
390                                 tmr_nacl->initiatorname);
391                 }
392         }
393         pr_debug("LUN_RESET: %s starting for [%s], tas: %d\n",
394                 (preempt_and_abort_list) ? "Preempt" : "TMR",
395                 dev->transport->name, tas);
396
397         core_tmr_drain_tmr_list(dev, tmr, preempt_and_abort_list);
398         core_tmr_drain_task_list(dev, prout_cmd, tmr_nacl, tas,
399                                 preempt_and_abort_list);
400         core_tmr_drain_cmd_list(dev, prout_cmd, tmr_nacl, tas,
401                                 preempt_and_abort_list);
402         /*
403          * Clear any legacy SPC-2 reservation when called during
404          * LOGICAL UNIT RESET
405          */
406         if (!preempt_and_abort_list &&
407              (dev->dev_flags & DF_SPC2_RESERVATIONS)) {
408                 spin_lock(&dev->dev_reservation_lock);
409                 dev->dev_reserved_node_acl = NULL;
410                 dev->dev_flags &= ~DF_SPC2_RESERVATIONS;
411                 spin_unlock(&dev->dev_reservation_lock);
412                 pr_debug("LUN_RESET: SCSI-2 Released reservation\n");
413         }
414
415         spin_lock_irq(&dev->stats_lock);
416         dev->num_resets++;
417         spin_unlock_irq(&dev->stats_lock);
418
419         pr_debug("LUN_RESET: %s for [%s] Complete\n",
420                         (preempt_and_abort_list) ? "Preempt" : "TMR",
421                         dev->transport->name);
422         return 0;
423 }
424