asus-nb-wmi: Asus Notebooks WMI Driver
[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 #define DEBUG_LUN_RESET
45 #ifdef DEBUG_LUN_RESET
46 #define DEBUG_LR(x...) printk(KERN_INFO x)
47 #else
48 #define DEBUG_LR(x...)
49 #endif
50
51 struct se_tmr_req *core_tmr_alloc_req(
52         struct se_cmd *se_cmd,
53         void *fabric_tmr_ptr,
54         u8 function)
55 {
56         struct se_tmr_req *tmr;
57
58         tmr = kmem_cache_zalloc(se_tmr_req_cache, GFP_KERNEL);
59         if (!(tmr)) {
60                 printk(KERN_ERR "Unable to allocate struct se_tmr_req\n");
61                 return ERR_PTR(-ENOMEM);
62         }
63         tmr->task_cmd = se_cmd;
64         tmr->fabric_tmr_ptr = fabric_tmr_ptr;
65         tmr->function = function;
66         INIT_LIST_HEAD(&tmr->tmr_list);
67
68         return tmr;
69 }
70 EXPORT_SYMBOL(core_tmr_alloc_req);
71
72 void core_tmr_release_req(
73         struct se_tmr_req *tmr)
74 {
75         struct se_device *dev = tmr->tmr_dev;
76
77         spin_lock(&dev->se_tmr_lock);
78         list_del(&tmr->tmr_list);
79         kmem_cache_free(se_tmr_req_cache, tmr);
80         spin_unlock(&dev->se_tmr_lock);
81 }
82
83 static void core_tmr_handle_tas_abort(
84         struct se_node_acl *tmr_nacl,
85         struct se_cmd *cmd,
86         int tas,
87         int fe_count)
88 {
89         if (!(fe_count)) {
90                 transport_cmd_finish_abort(cmd, 1);
91                 return;
92         }
93         /*
94          * TASK ABORTED status (TAS) bit support
95         */
96         if (((tmr_nacl != NULL) &&
97              (tmr_nacl == cmd->se_sess->se_node_acl)) || tas)
98                 transport_send_task_abort(cmd);
99
100         transport_cmd_finish_abort(cmd, 0);
101 }
102
103 int core_tmr_lun_reset(
104         struct se_device *dev,
105         struct se_tmr_req *tmr,
106         struct list_head *preempt_and_abort_list,
107         struct se_cmd *prout_cmd)
108 {
109         struct se_cmd *cmd;
110         struct se_queue_req *qr, *qr_tmp;
111         struct se_node_acl *tmr_nacl = NULL;
112         struct se_portal_group *tmr_tpg = NULL;
113         struct se_queue_obj *qobj = dev->dev_queue_obj;
114         struct se_tmr_req *tmr_p, *tmr_pp;
115         struct se_task *task, *task_tmp;
116         unsigned long flags;
117         int fe_count, state, tas;
118         /*
119          * TASK_ABORTED status bit, this is configurable via ConfigFS
120          * struct se_device attributes.  spc4r17 section 7.4.6 Control mode page
121          *
122          * A task aborted status (TAS) bit set to zero specifies that aborted
123          * tasks shall be terminated by the device server without any response
124          * to the application client. A TAS bit set to one specifies that tasks
125          * aborted by the actions of an I_T nexus other than the I_T nexus on
126          * which the command was received shall be completed with TASK ABORTED
127          * status (see SAM-4).
128          */
129         tas = DEV_ATTRIB(dev)->emulate_tas;
130         /*
131          * Determine if this se_tmr is coming from a $FABRIC_MOD
132          * or struct se_device passthrough..
133          */
134         if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) {
135                 tmr_nacl = tmr->task_cmd->se_sess->se_node_acl;
136                 tmr_tpg = tmr->task_cmd->se_sess->se_tpg;
137                 if (tmr_nacl && tmr_tpg) {
138                         DEBUG_LR("LUN_RESET: TMR caller fabric: %s"
139                                 " initiator port %s\n",
140                                 TPG_TFO(tmr_tpg)->get_fabric_name(),
141                                 tmr_nacl->initiatorname);
142                 }
143         }
144         DEBUG_LR("LUN_RESET: %s starting for [%s], tas: %d\n",
145                 (preempt_and_abort_list) ? "Preempt" : "TMR",
146                 TRANSPORT(dev)->name, tas);
147         /*
148          * Release all pending and outgoing TMRs aside from the received
149          * LUN_RESET tmr..
150          */
151         spin_lock(&dev->se_tmr_lock);
152         list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) {
153                 /*
154                  * Allow the received TMR to return with FUNCTION_COMPLETE.
155                  */
156                 if (tmr && (tmr_p == tmr))
157                         continue;
158
159                 cmd = tmr_p->task_cmd;
160                 if (!(cmd)) {
161                         printk(KERN_ERR "Unable to locate struct se_cmd for TMR\n");
162                         continue;
163                 }
164                 /*
165                  * If this function was called with a valid pr_res_key
166                  * parameter (eg: for PROUT PREEMPT_AND_ABORT service action
167                  * skip non regisration key matching TMRs.
168                  */
169                 if ((preempt_and_abort_list != NULL) &&
170                     (core_scsi3_check_cdb_abort_and_preempt(
171                                         preempt_and_abort_list, cmd) != 0))
172                         continue;
173                 spin_unlock(&dev->se_tmr_lock);
174
175                 spin_lock_irqsave(&T_TASK(cmd)->t_state_lock, flags);
176                 if (!(atomic_read(&T_TASK(cmd)->t_transport_active))) {
177                         spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock, flags);
178                         spin_lock(&dev->se_tmr_lock);
179                         continue;
180                 }
181                 if (cmd->t_state == TRANSPORT_ISTATE_PROCESSING) {
182                         spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock, flags);
183                         spin_lock(&dev->se_tmr_lock);
184                         continue;
185                 }
186                 DEBUG_LR("LUN_RESET: %s releasing TMR %p Function: 0x%02x,"
187                         " Response: 0x%02x, t_state: %d\n",
188                         (preempt_and_abort_list) ? "Preempt" : "", tmr_p,
189                         tmr_p->function, tmr_p->response, cmd->t_state);
190                 spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock, flags);
191
192                 transport_cmd_finish_abort_tmr(cmd);
193                 spin_lock(&dev->se_tmr_lock);
194         }
195         spin_unlock(&dev->se_tmr_lock);
196         /*
197          * Complete outstanding struct se_task CDBs with TASK_ABORTED SAM status.
198          * This is following sam4r17, section 5.6 Aborting commands, Table 38
199          * for TMR LUN_RESET:
200          *
201          * a) "Yes" indicates that each command that is aborted on an I_T nexus
202          * other than the one that caused the SCSI device condition is
203          * completed with TASK ABORTED status, if the TAS bit is set to one in
204          * the Control mode page (see SPC-4). "No" indicates that no status is
205          * returned for aborted commands.
206          *
207          * d) If the logical unit reset is caused by a particular I_T nexus
208          * (e.g., by a LOGICAL UNIT RESET task management function), then "yes"
209          * (TASK_ABORTED status) applies.
210          *
211          * Otherwise (e.g., if triggered by a hard reset), "no"
212          * (no TASK_ABORTED SAM status) applies.
213          *
214          * Note that this seems to be independent of TAS (Task Aborted Status)
215          * in the Control Mode Page.
216          */
217         spin_lock_irqsave(&dev->execute_task_lock, flags);
218         list_for_each_entry_safe(task, task_tmp, &dev->state_task_list,
219                                 t_state_list) {
220                 if (!(TASK_CMD(task))) {
221                         printk(KERN_ERR "TASK_CMD(task) is NULL!\n");
222                         continue;
223                 }
224                 cmd = TASK_CMD(task);
225
226                 if (!T_TASK(cmd)) {
227                         printk(KERN_ERR "T_TASK(cmd) is NULL for task: %p cmd:"
228                                 " %p ITT: 0x%08x\n", task, cmd,
229                                 CMD_TFO(cmd)->get_task_tag(cmd));
230                         continue;
231                 }
232                 /*
233                  * For PREEMPT_AND_ABORT usage, only process commands
234                  * with a matching reservation key.
235                  */
236                 if ((preempt_and_abort_list != NULL) &&
237                     (core_scsi3_check_cdb_abort_and_preempt(
238                                         preempt_and_abort_list, cmd) != 0))
239                         continue;
240                 /*
241                  * Not aborting PROUT PREEMPT_AND_ABORT CDB..
242                  */
243                 if (prout_cmd == cmd)
244                         continue;
245
246                 list_del(&task->t_state_list);
247                 atomic_set(&task->task_state_active, 0);
248                 spin_unlock_irqrestore(&dev->execute_task_lock, flags);
249
250                 spin_lock_irqsave(&T_TASK(cmd)->t_state_lock, flags);
251                 DEBUG_LR("LUN_RESET: %s cmd: %p task: %p"
252                         " ITT/CmdSN: 0x%08x/0x%08x, i_state: %d, t_state/"
253                         "def_t_state: %d/%d cdb: 0x%02x\n",
254                         (preempt_and_abort_list) ? "Preempt" : "", cmd, task,
255                         CMD_TFO(cmd)->get_task_tag(cmd), 0,
256                         CMD_TFO(cmd)->get_cmd_state(cmd), cmd->t_state,
257                         cmd->deferred_t_state, T_TASK(cmd)->t_task_cdb[0]);
258                 DEBUG_LR("LUN_RESET: ITT[0x%08x] - pr_res_key: 0x%016Lx"
259                         " t_task_cdbs: %d t_task_cdbs_left: %d"
260                         " t_task_cdbs_sent: %d -- t_transport_active: %d"
261                         " t_transport_stop: %d t_transport_sent: %d\n",
262                         CMD_TFO(cmd)->get_task_tag(cmd), cmd->pr_res_key,
263                         T_TASK(cmd)->t_task_cdbs,
264                         atomic_read(&T_TASK(cmd)->t_task_cdbs_left),
265                         atomic_read(&T_TASK(cmd)->t_task_cdbs_sent),
266                         atomic_read(&T_TASK(cmd)->t_transport_active),
267                         atomic_read(&T_TASK(cmd)->t_transport_stop),
268                         atomic_read(&T_TASK(cmd)->t_transport_sent));
269
270                 if (atomic_read(&task->task_active)) {
271                         atomic_set(&task->task_stop, 1);
272                         spin_unlock_irqrestore(
273                                 &T_TASK(cmd)->t_state_lock, flags);
274
275                         DEBUG_LR("LUN_RESET: Waiting for task: %p to shutdown"
276                                 " for dev: %p\n", task, dev);
277                         wait_for_completion(&task->task_stop_comp);
278                         DEBUG_LR("LUN_RESET Completed task: %p shutdown for"
279                                 " dev: %p\n", task, dev);
280                         spin_lock_irqsave(&T_TASK(cmd)->t_state_lock, flags);
281                         atomic_dec(&T_TASK(cmd)->t_task_cdbs_left);
282
283                         atomic_set(&task->task_active, 0);
284                         atomic_set(&task->task_stop, 0);
285                 } else {
286                         if (atomic_read(&task->task_execute_queue) != 0)
287                                 transport_remove_task_from_execute_queue(task, dev);
288                 }
289                 __transport_stop_task_timer(task, &flags);
290
291                 if (!(atomic_dec_and_test(&T_TASK(cmd)->t_task_cdbs_ex_left))) {
292                         spin_unlock_irqrestore(
293                                         &T_TASK(cmd)->t_state_lock, flags);
294                         DEBUG_LR("LUN_RESET: Skipping task: %p, dev: %p for"
295                                 " t_task_cdbs_ex_left: %d\n", task, dev,
296                                 atomic_read(&T_TASK(cmd)->t_task_cdbs_ex_left));
297
298                         spin_lock_irqsave(&dev->execute_task_lock, flags);
299                         continue;
300                 }
301                 fe_count = atomic_read(&T_TASK(cmd)->t_fe_count);
302
303                 if (atomic_read(&T_TASK(cmd)->t_transport_active)) {
304                         DEBUG_LR("LUN_RESET: got t_transport_active = 1 for"
305                                 " task: %p, t_fe_count: %d dev: %p\n", task,
306                                 fe_count, dev);
307                         atomic_set(&T_TASK(cmd)->t_transport_aborted, 1);
308                         spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock,
309                                                 flags);
310                         core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
311
312                         spin_lock_irqsave(&dev->execute_task_lock, flags);
313                         continue;
314                 }
315                 DEBUG_LR("LUN_RESET: Got t_transport_active = 0 for task: %p,"
316                         " t_fe_count: %d dev: %p\n", task, fe_count, dev);
317                 atomic_set(&T_TASK(cmd)->t_transport_aborted, 1);
318                 spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock, flags);
319                 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
320
321                 spin_lock_irqsave(&dev->execute_task_lock, flags);
322         }
323         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
324         /*
325          * Release all commands remaining in the struct se_device cmd queue.
326          *
327          * This follows the same logic as above for the struct se_device
328          * struct se_task state list, where commands are returned with
329          * TASK_ABORTED status, if there is an outstanding $FABRIC_MOD
330          * reference, otherwise the struct se_cmd is released.
331          */
332         spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
333         list_for_each_entry_safe(qr, qr_tmp, &qobj->qobj_list, qr_list) {
334                 cmd = (struct se_cmd *)qr->cmd;
335                 if (!(cmd)) {
336                         /*
337                          * Skip these for non PREEMPT_AND_ABORT usage..
338                          */
339                         if (preempt_and_abort_list != NULL)
340                                 continue;
341
342                         atomic_dec(&qobj->queue_cnt);
343                         list_del(&qr->qr_list);
344                         kfree(qr);
345                         continue;
346                 }
347                 /*
348                  * For PREEMPT_AND_ABORT usage, only process commands
349                  * with a matching reservation key.
350                  */
351                 if ((preempt_and_abort_list != NULL) &&
352                     (core_scsi3_check_cdb_abort_and_preempt(
353                                         preempt_and_abort_list, cmd) != 0))
354                         continue;
355                 /*
356                  * Not aborting PROUT PREEMPT_AND_ABORT CDB..
357                  */
358                 if (prout_cmd == cmd)
359                         continue;
360
361                 atomic_dec(&T_TASK(cmd)->t_transport_queue_active);
362                 atomic_dec(&qobj->queue_cnt);
363                 list_del(&qr->qr_list);
364                 spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
365
366                 state = qr->state;
367                 kfree(qr);
368
369                 DEBUG_LR("LUN_RESET: %s from Device Queue: cmd: %p t_state:"
370                         " %d t_fe_count: %d\n", (preempt_and_abort_list) ?
371                         "Preempt" : "", cmd, state,
372                         atomic_read(&T_TASK(cmd)->t_fe_count));
373                 /*
374                  * Signal that the command has failed via cmd->se_cmd_flags,
375                  * and call TFO->new_cmd_failure() to wakeup any fabric
376                  * dependent code used to wait for unsolicited data out
377                  * allocation to complete.  The fabric module is expected
378                  * to dump any remaining unsolicited data out for the aborted
379                  * command at this point.
380                  */
381                 transport_new_cmd_failure(cmd);
382
383                 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas,
384                                 atomic_read(&T_TASK(cmd)->t_fe_count));
385                 spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
386         }
387         spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
388         /*
389          * Clear any legacy SPC-2 reservation when called during
390          * LOGICAL UNIT RESET
391          */
392         if (!(preempt_and_abort_list) &&
393              (dev->dev_flags & DF_SPC2_RESERVATIONS)) {
394                 spin_lock(&dev->dev_reservation_lock);
395                 dev->dev_reserved_node_acl = NULL;
396                 dev->dev_flags &= ~DF_SPC2_RESERVATIONS;
397                 spin_unlock(&dev->dev_reservation_lock);
398                 printk(KERN_INFO "LUN_RESET: SCSI-2 Released reservation\n");
399         }
400
401         spin_lock(&dev->stats_lock);
402         dev->num_resets++;
403         spin_unlock(&dev->stats_lock);
404
405         DEBUG_LR("LUN_RESET: %s for [%s] Complete\n",
406                         (preempt_and_abort_list) ? "Preempt" : "TMR",
407                         TRANSPORT(dev)->name);
408         return 0;
409 }