target: Fix wrong se_tmr being added to drain_tmr_list
[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/version.h>
28 #include <linux/slab.h>
29 #include <linux/spinlock.h>
30 #include <linux/list.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 {
49         struct se_tmr_req *tmr;
50
51         tmr = kmem_cache_zalloc(se_tmr_req_cache, (in_interrupt()) ?
52                                         GFP_ATOMIC : GFP_KERNEL);
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 && (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         while (!list_empty(&drain_tmr_list)) {
156                 tmr = list_entry(drain_tmr_list.next, struct se_tmr_req, tmr_list);
157                 list_del(&tmr->tmr_list);
158                 cmd = tmr->task_cmd;
159
160                 pr_debug("LUN_RESET: %s releasing TMR %p Function: 0x%02x,"
161                         " Response: 0x%02x, t_state: %d\n",
162                         (preempt_and_abort_list) ? "Preempt" : "", tmr,
163                         tmr->function, tmr->response, cmd->t_state);
164
165                 transport_cmd_finish_abort_tmr(cmd);
166         }
167 }
168
169 static void core_tmr_drain_task_list(
170         struct se_device *dev,
171         struct se_cmd *prout_cmd,
172         struct se_node_acl *tmr_nacl,
173         int tas,
174         struct list_head *preempt_and_abort_list)
175 {
176         LIST_HEAD(drain_task_list);
177         struct se_cmd *cmd;
178         struct se_task *task, *task_tmp;
179         unsigned long flags;
180         int fe_count;
181         /*
182          * Complete outstanding struct se_task CDBs with TASK_ABORTED SAM status.
183          * This is following sam4r17, section 5.6 Aborting commands, Table 38
184          * for TMR LUN_RESET:
185          *
186          * a) "Yes" indicates that each command that is aborted on an I_T nexus
187          * other than the one that caused the SCSI device condition is
188          * completed with TASK ABORTED status, if the TAS bit is set to one in
189          * the Control mode page (see SPC-4). "No" indicates that no status is
190          * returned for aborted commands.
191          *
192          * d) If the logical unit reset is caused by a particular I_T nexus
193          * (e.g., by a LOGICAL UNIT RESET task management function), then "yes"
194          * (TASK_ABORTED status) applies.
195          *
196          * Otherwise (e.g., if triggered by a hard reset), "no"
197          * (no TASK_ABORTED SAM status) applies.
198          *
199          * Note that this seems to be independent of TAS (Task Aborted Status)
200          * in the Control Mode Page.
201          */
202         spin_lock_irqsave(&dev->execute_task_lock, flags);
203         list_for_each_entry_safe(task, task_tmp, &dev->state_task_list,
204                                 t_state_list) {
205                 if (!task->task_se_cmd) {
206                         pr_err("task->task_se_cmd is NULL!\n");
207                         continue;
208                 }
209                 cmd = task->task_se_cmd;
210
211                 /*
212                  * For PREEMPT_AND_ABORT usage, only process commands
213                  * with a matching reservation key.
214                  */
215                 if (preempt_and_abort_list &&
216                     (core_scsi3_check_cdb_abort_and_preempt(
217                                         preempt_and_abort_list, cmd) != 0))
218                         continue;
219                 /*
220                  * Not aborting PROUT PREEMPT_AND_ABORT CDB..
221                  */
222                 if (prout_cmd == cmd)
223                         continue;
224
225                 list_move_tail(&task->t_state_list, &drain_task_list);
226                 atomic_set(&task->task_state_active, 0);
227                 /*
228                  * Remove from task execute list before processing drain_task_list
229                  */
230                 if (atomic_read(&task->task_execute_queue) != 0) {
231                         list_del(&task->t_execute_list);
232                         atomic_set(&task->task_execute_queue, 0);
233                         atomic_dec(&dev->execute_tasks);
234                 }
235         }
236         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
237
238         while (!list_empty(&drain_task_list)) {
239                 task = list_entry(drain_task_list.next, struct se_task, t_state_list);
240                 list_del(&task->t_state_list);
241                 cmd = task->task_se_cmd;
242
243                 spin_lock_irqsave(&cmd->t_state_lock, flags);
244                 pr_debug("LUN_RESET: %s cmd: %p task: %p"
245                         " ITT/CmdSN: 0x%08x/0x%08x, i_state: %d, t_state/"
246                         "def_t_state: %d/%d cdb: 0x%02x\n",
247                         (preempt_and_abort_list) ? "Preempt" : "", cmd, task,
248                         cmd->se_tfo->get_task_tag(cmd), 0,
249                         cmd->se_tfo->get_cmd_state(cmd), cmd->t_state,
250                         cmd->deferred_t_state, cmd->t_task_cdb[0]);
251                 pr_debug("LUN_RESET: ITT[0x%08x] - pr_res_key: 0x%016Lx"
252                         " t_task_cdbs: %d t_task_cdbs_left: %d"
253                         " t_task_cdbs_sent: %d -- t_transport_active: %d"
254                         " t_transport_stop: %d t_transport_sent: %d\n",
255                         cmd->se_tfo->get_task_tag(cmd), cmd->pr_res_key,
256                         cmd->t_task_list_num,
257                         atomic_read(&cmd->t_task_cdbs_left),
258                         atomic_read(&cmd->t_task_cdbs_sent),
259                         atomic_read(&cmd->t_transport_active),
260                         atomic_read(&cmd->t_transport_stop),
261                         atomic_read(&cmd->t_transport_sent));
262
263                 if (atomic_read(&task->task_active)) {
264                         atomic_set(&task->task_stop, 1);
265                         spin_unlock_irqrestore(
266                                 &cmd->t_state_lock, flags);
267
268                         pr_debug("LUN_RESET: Waiting for task: %p to shutdown"
269                                 " for dev: %p\n", task, dev);
270                         wait_for_completion(&task->task_stop_comp);
271                         pr_debug("LUN_RESET Completed task: %p shutdown for"
272                                 " dev: %p\n", task, dev);
273                         spin_lock_irqsave(&cmd->t_state_lock, flags);
274                         atomic_dec(&cmd->t_task_cdbs_left);
275
276                         atomic_set(&task->task_active, 0);
277                         atomic_set(&task->task_stop, 0);
278                 }
279                 __transport_stop_task_timer(task, &flags);
280
281                 if (!atomic_dec_and_test(&cmd->t_task_cdbs_ex_left)) {
282                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
283                         pr_debug("LUN_RESET: Skipping task: %p, dev: %p for"
284                                 " t_task_cdbs_ex_left: %d\n", task, dev,
285                                 atomic_read(&cmd->t_task_cdbs_ex_left));
286                         continue;
287                 }
288                 fe_count = atomic_read(&cmd->t_fe_count);
289
290                 if (atomic_read(&cmd->t_transport_active)) {
291                         pr_debug("LUN_RESET: got t_transport_active = 1 for"
292                                 " task: %p, t_fe_count: %d dev: %p\n", task,
293                                 fe_count, dev);
294                         atomic_set(&cmd->t_transport_aborted, 1);
295                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
296
297                         core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
298                         continue;
299                 }
300                 pr_debug("LUN_RESET: Got t_transport_active = 0 for task: %p,"
301                         " t_fe_count: %d dev: %p\n", task, fe_count, dev);
302                 atomic_set(&cmd->t_transport_aborted, 1);
303                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
304
305                 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
306         }
307 }
308
309 static void core_tmr_drain_cmd_list(
310         struct se_device *dev,
311         struct se_cmd *prout_cmd,
312         struct se_node_acl *tmr_nacl,
313         int tas,
314         struct list_head *preempt_and_abort_list)
315 {
316         LIST_HEAD(drain_cmd_list);
317         struct se_queue_obj *qobj = &dev->dev_queue_obj;
318         struct se_cmd *cmd, *tcmd;
319         unsigned long flags;
320         /*
321          * Release all commands remaining in the struct se_device cmd queue.
322          *
323          * This follows the same logic as above for the struct se_device
324          * struct se_task state list, where commands are returned with
325          * TASK_ABORTED status, if there is an outstanding $FABRIC_MOD
326          * reference, otherwise the struct se_cmd is released.
327          */
328         spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
329         list_for_each_entry_safe(cmd, tcmd, &qobj->qobj_list, se_queue_node) {
330                 /*
331                  * For PREEMPT_AND_ABORT usage, only process commands
332                  * with a matching reservation key.
333                  */
334                 if (preempt_and_abort_list &&
335                     (core_scsi3_check_cdb_abort_and_preempt(
336                                         preempt_and_abort_list, cmd) != 0))
337                         continue;
338                 /*
339                  * Not aborting PROUT PREEMPT_AND_ABORT CDB..
340                  */
341                 if (prout_cmd == cmd)
342                         continue;
343                 /*
344                  * Skip direct processing of TRANSPORT_FREE_CMD_INTR for
345                  * HW target mode fabrics.
346                  */
347                 spin_lock(&cmd->t_state_lock);
348                 if (cmd->t_state == TRANSPORT_FREE_CMD_INTR) {
349                         spin_unlock(&cmd->t_state_lock);
350                         continue;
351                 }
352                 spin_unlock(&cmd->t_state_lock);
353
354                 atomic_set(&cmd->t_transport_queue_active, 0);
355                 atomic_dec(&qobj->queue_cnt);
356                 list_move_tail(&cmd->se_queue_node, &drain_cmd_list);
357         }
358         spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
359
360         while (!list_empty(&drain_cmd_list)) {
361                 cmd = list_entry(drain_cmd_list.next, struct se_cmd, se_queue_node);
362                 list_del_init(&cmd->se_queue_node);
363
364                 pr_debug("LUN_RESET: %s from Device Queue: cmd: %p t_state:"
365                         " %d t_fe_count: %d\n", (preempt_and_abort_list) ?
366                         "Preempt" : "", cmd, cmd->t_state,
367                         atomic_read(&cmd->t_fe_count));
368                 /*
369                  * Signal that the command has failed via cmd->se_cmd_flags,
370                  */
371                 transport_new_cmd_failure(cmd);
372
373                 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas,
374                                 atomic_read(&cmd->t_fe_count));
375         }
376 }
377
378 int core_tmr_lun_reset(
379         struct se_device *dev,
380         struct se_tmr_req *tmr,
381         struct list_head *preempt_and_abort_list,
382         struct se_cmd *prout_cmd)
383 {
384         struct se_node_acl *tmr_nacl = NULL;
385         struct se_portal_group *tmr_tpg = NULL;
386         int tas;
387         /*
388          * TASK_ABORTED status bit, this is configurable via ConfigFS
389          * struct se_device attributes.  spc4r17 section 7.4.6 Control mode page
390          *
391          * A task aborted status (TAS) bit set to zero specifies that aborted
392          * tasks shall be terminated by the device server without any response
393          * to the application client. A TAS bit set to one specifies that tasks
394          * aborted by the actions of an I_T nexus other than the I_T nexus on
395          * which the command was received shall be completed with TASK ABORTED
396          * status (see SAM-4).
397          */
398         tas = dev->se_sub_dev->se_dev_attrib.emulate_tas;
399         /*
400          * Determine if this se_tmr is coming from a $FABRIC_MOD
401          * or struct se_device passthrough..
402          */
403         if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) {
404                 tmr_nacl = tmr->task_cmd->se_sess->se_node_acl;
405                 tmr_tpg = tmr->task_cmd->se_sess->se_tpg;
406                 if (tmr_nacl && tmr_tpg) {
407                         pr_debug("LUN_RESET: TMR caller fabric: %s"
408                                 " initiator port %s\n",
409                                 tmr_tpg->se_tpg_tfo->get_fabric_name(),
410                                 tmr_nacl->initiatorname);
411                 }
412         }
413         pr_debug("LUN_RESET: %s starting for [%s], tas: %d\n",
414                 (preempt_and_abort_list) ? "Preempt" : "TMR",
415                 dev->transport->name, tas);
416
417         core_tmr_drain_tmr_list(dev, tmr, preempt_and_abort_list);
418         core_tmr_drain_task_list(dev, prout_cmd, tmr_nacl, tas,
419                                 preempt_and_abort_list);
420         core_tmr_drain_cmd_list(dev, prout_cmd, tmr_nacl, tas,
421                                 preempt_and_abort_list);
422         /*
423          * Clear any legacy SPC-2 reservation when called during
424          * LOGICAL UNIT RESET
425          */
426         if (!preempt_and_abort_list &&
427              (dev->dev_flags & DF_SPC2_RESERVATIONS)) {
428                 spin_lock(&dev->dev_reservation_lock);
429                 dev->dev_reserved_node_acl = NULL;
430                 dev->dev_flags &= ~DF_SPC2_RESERVATIONS;
431                 spin_unlock(&dev->dev_reservation_lock);
432                 pr_debug("LUN_RESET: SCSI-2 Released reservation\n");
433         }
434
435         spin_lock_irq(&dev->stats_lock);
436         dev->num_resets++;
437         spin_unlock_irq(&dev->stats_lock);
438
439         pr_debug("LUN_RESET: %s for [%s] Complete\n",
440                         (preempt_and_abort_list) ? "Preempt" : "TMR",
441                         dev->transport->name);
442         return 0;
443 }
444