target: Fix transport_get_lun_for_tmr failure cases
[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, (in_interrupt()) ?
59                                         GFP_ATOMIC : GFP_KERNEL);
60         if (!(tmr)) {
61                 printk(KERN_ERR "Unable to allocate struct se_tmr_req\n");
62                 return ERR_PTR(-ENOMEM);
63         }
64         tmr->task_cmd = se_cmd;
65         tmr->fabric_tmr_ptr = fabric_tmr_ptr;
66         tmr->function = function;
67         INIT_LIST_HEAD(&tmr->tmr_list);
68
69         return tmr;
70 }
71 EXPORT_SYMBOL(core_tmr_alloc_req);
72
73 void core_tmr_release_req(
74         struct se_tmr_req *tmr)
75 {
76         struct se_device *dev = tmr->tmr_dev;
77
78         if (!dev) {
79                 kmem_cache_free(se_tmr_req_cache, tmr);
80                 return;
81         }
82
83         spin_lock(&dev->se_tmr_lock);
84         list_del(&tmr->tmr_list);
85         spin_unlock(&dev->se_tmr_lock);
86
87         kmem_cache_free(se_tmr_req_cache, tmr);
88 }
89
90 static void core_tmr_handle_tas_abort(
91         struct se_node_acl *tmr_nacl,
92         struct se_cmd *cmd,
93         int tas,
94         int fe_count)
95 {
96         if (!(fe_count)) {
97                 transport_cmd_finish_abort(cmd, 1);
98                 return;
99         }
100         /*
101          * TASK ABORTED status (TAS) bit support
102         */
103         if (((tmr_nacl != NULL) &&
104              (tmr_nacl == cmd->se_sess->se_node_acl)) || tas)
105                 transport_send_task_abort(cmd);
106
107         transport_cmd_finish_abort(cmd, 0);
108 }
109
110 int core_tmr_lun_reset(
111         struct se_device *dev,
112         struct se_tmr_req *tmr,
113         struct list_head *preempt_and_abort_list,
114         struct se_cmd *prout_cmd)
115 {
116         struct se_cmd *cmd;
117         struct se_queue_req *qr, *qr_tmp;
118         struct se_node_acl *tmr_nacl = NULL;
119         struct se_portal_group *tmr_tpg = NULL;
120         struct se_queue_obj *qobj = dev->dev_queue_obj;
121         struct se_tmr_req *tmr_p, *tmr_pp;
122         struct se_task *task, *task_tmp;
123         unsigned long flags;
124         int fe_count, state, tas;
125         /*
126          * TASK_ABORTED status bit, this is configurable via ConfigFS
127          * struct se_device attributes.  spc4r17 section 7.4.6 Control mode page
128          *
129          * A task aborted status (TAS) bit set to zero specifies that aborted
130          * tasks shall be terminated by the device server without any response
131          * to the application client. A TAS bit set to one specifies that tasks
132          * aborted by the actions of an I_T nexus other than the I_T nexus on
133          * which the command was received shall be completed with TASK ABORTED
134          * status (see SAM-4).
135          */
136         tas = DEV_ATTRIB(dev)->emulate_tas;
137         /*
138          * Determine if this se_tmr is coming from a $FABRIC_MOD
139          * or struct se_device passthrough..
140          */
141         if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) {
142                 tmr_nacl = tmr->task_cmd->se_sess->se_node_acl;
143                 tmr_tpg = tmr->task_cmd->se_sess->se_tpg;
144                 if (tmr_nacl && tmr_tpg) {
145                         DEBUG_LR("LUN_RESET: TMR caller fabric: %s"
146                                 " initiator port %s\n",
147                                 TPG_TFO(tmr_tpg)->get_fabric_name(),
148                                 tmr_nacl->initiatorname);
149                 }
150         }
151         DEBUG_LR("LUN_RESET: %s starting for [%s], tas: %d\n",
152                 (preempt_and_abort_list) ? "Preempt" : "TMR",
153                 TRANSPORT(dev)->name, tas);
154         /*
155          * Release all pending and outgoing TMRs aside from the received
156          * LUN_RESET tmr..
157          */
158         spin_lock(&dev->se_tmr_lock);
159         list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) {
160                 /*
161                  * Allow the received TMR to return with FUNCTION_COMPLETE.
162                  */
163                 if (tmr && (tmr_p == tmr))
164                         continue;
165
166                 cmd = tmr_p->task_cmd;
167                 if (!(cmd)) {
168                         printk(KERN_ERR "Unable to locate struct se_cmd for TMR\n");
169                         continue;
170                 }
171                 /*
172                  * If this function was called with a valid pr_res_key
173                  * parameter (eg: for PROUT PREEMPT_AND_ABORT service action
174                  * skip non regisration key matching TMRs.
175                  */
176                 if ((preempt_and_abort_list != NULL) &&
177                     (core_scsi3_check_cdb_abort_and_preempt(
178                                         preempt_and_abort_list, cmd) != 0))
179                         continue;
180                 spin_unlock(&dev->se_tmr_lock);
181
182                 spin_lock_irqsave(&T_TASK(cmd)->t_state_lock, flags);
183                 if (!(atomic_read(&T_TASK(cmd)->t_transport_active))) {
184                         spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock, flags);
185                         spin_lock(&dev->se_tmr_lock);
186                         continue;
187                 }
188                 if (cmd->t_state == TRANSPORT_ISTATE_PROCESSING) {
189                         spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock, flags);
190                         spin_lock(&dev->se_tmr_lock);
191                         continue;
192                 }
193                 DEBUG_LR("LUN_RESET: %s releasing TMR %p Function: 0x%02x,"
194                         " Response: 0x%02x, t_state: %d\n",
195                         (preempt_and_abort_list) ? "Preempt" : "", tmr_p,
196                         tmr_p->function, tmr_p->response, cmd->t_state);
197                 spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock, flags);
198
199                 transport_cmd_finish_abort_tmr(cmd);
200                 spin_lock(&dev->se_tmr_lock);
201         }
202         spin_unlock(&dev->se_tmr_lock);
203         /*
204          * Complete outstanding struct se_task CDBs with TASK_ABORTED SAM status.
205          * This is following sam4r17, section 5.6 Aborting commands, Table 38
206          * for TMR LUN_RESET:
207          *
208          * a) "Yes" indicates that each command that is aborted on an I_T nexus
209          * other than the one that caused the SCSI device condition is
210          * completed with TASK ABORTED status, if the TAS bit is set to one in
211          * the Control mode page (see SPC-4). "No" indicates that no status is
212          * returned for aborted commands.
213          *
214          * d) If the logical unit reset is caused by a particular I_T nexus
215          * (e.g., by a LOGICAL UNIT RESET task management function), then "yes"
216          * (TASK_ABORTED status) applies.
217          *
218          * Otherwise (e.g., if triggered by a hard reset), "no"
219          * (no TASK_ABORTED SAM status) applies.
220          *
221          * Note that this seems to be independent of TAS (Task Aborted Status)
222          * in the Control Mode Page.
223          */
224         spin_lock_irqsave(&dev->execute_task_lock, flags);
225         list_for_each_entry_safe(task, task_tmp, &dev->state_task_list,
226                                 t_state_list) {
227                 if (!(TASK_CMD(task))) {
228                         printk(KERN_ERR "TASK_CMD(task) is NULL!\n");
229                         continue;
230                 }
231                 cmd = TASK_CMD(task);
232
233                 if (!T_TASK(cmd)) {
234                         printk(KERN_ERR "T_TASK(cmd) is NULL for task: %p cmd:"
235                                 " %p ITT: 0x%08x\n", task, cmd,
236                                 CMD_TFO(cmd)->get_task_tag(cmd));
237                         continue;
238                 }
239                 /*
240                  * For PREEMPT_AND_ABORT usage, only process commands
241                  * with a matching reservation key.
242                  */
243                 if ((preempt_and_abort_list != NULL) &&
244                     (core_scsi3_check_cdb_abort_and_preempt(
245                                         preempt_and_abort_list, cmd) != 0))
246                         continue;
247                 /*
248                  * Not aborting PROUT PREEMPT_AND_ABORT CDB..
249                  */
250                 if (prout_cmd == cmd)
251                         continue;
252
253                 list_del(&task->t_state_list);
254                 atomic_set(&task->task_state_active, 0);
255                 spin_unlock_irqrestore(&dev->execute_task_lock, flags);
256
257                 spin_lock_irqsave(&T_TASK(cmd)->t_state_lock, flags);
258                 DEBUG_LR("LUN_RESET: %s cmd: %p task: %p"
259                         " ITT/CmdSN: 0x%08x/0x%08x, i_state: %d, t_state/"
260                         "def_t_state: %d/%d cdb: 0x%02x\n",
261                         (preempt_and_abort_list) ? "Preempt" : "", cmd, task,
262                         CMD_TFO(cmd)->get_task_tag(cmd), 0,
263                         CMD_TFO(cmd)->get_cmd_state(cmd), cmd->t_state,
264                         cmd->deferred_t_state, T_TASK(cmd)->t_task_cdb[0]);
265                 DEBUG_LR("LUN_RESET: ITT[0x%08x] - pr_res_key: 0x%016Lx"
266                         " t_task_cdbs: %d t_task_cdbs_left: %d"
267                         " t_task_cdbs_sent: %d -- t_transport_active: %d"
268                         " t_transport_stop: %d t_transport_sent: %d\n",
269                         CMD_TFO(cmd)->get_task_tag(cmd), cmd->pr_res_key,
270                         T_TASK(cmd)->t_task_cdbs,
271                         atomic_read(&T_TASK(cmd)->t_task_cdbs_left),
272                         atomic_read(&T_TASK(cmd)->t_task_cdbs_sent),
273                         atomic_read(&T_TASK(cmd)->t_transport_active),
274                         atomic_read(&T_TASK(cmd)->t_transport_stop),
275                         atomic_read(&T_TASK(cmd)->t_transport_sent));
276
277                 if (atomic_read(&task->task_active)) {
278                         atomic_set(&task->task_stop, 1);
279                         spin_unlock_irqrestore(
280                                 &T_TASK(cmd)->t_state_lock, flags);
281
282                         DEBUG_LR("LUN_RESET: Waiting for task: %p to shutdown"
283                                 " for dev: %p\n", task, dev);
284                         wait_for_completion(&task->task_stop_comp);
285                         DEBUG_LR("LUN_RESET Completed task: %p shutdown for"
286                                 " dev: %p\n", task, dev);
287                         spin_lock_irqsave(&T_TASK(cmd)->t_state_lock, flags);
288                         atomic_dec(&T_TASK(cmd)->t_task_cdbs_left);
289
290                         atomic_set(&task->task_active, 0);
291                         atomic_set(&task->task_stop, 0);
292                 } else {
293                         if (atomic_read(&task->task_execute_queue) != 0)
294                                 transport_remove_task_from_execute_queue(task, dev);
295                 }
296                 __transport_stop_task_timer(task, &flags);
297
298                 if (!(atomic_dec_and_test(&T_TASK(cmd)->t_task_cdbs_ex_left))) {
299                         spin_unlock_irqrestore(
300                                         &T_TASK(cmd)->t_state_lock, flags);
301                         DEBUG_LR("LUN_RESET: Skipping task: %p, dev: %p for"
302                                 " t_task_cdbs_ex_left: %d\n", task, dev,
303                                 atomic_read(&T_TASK(cmd)->t_task_cdbs_ex_left));
304
305                         spin_lock_irqsave(&dev->execute_task_lock, flags);
306                         continue;
307                 }
308                 fe_count = atomic_read(&T_TASK(cmd)->t_fe_count);
309
310                 if (atomic_read(&T_TASK(cmd)->t_transport_active)) {
311                         DEBUG_LR("LUN_RESET: got t_transport_active = 1 for"
312                                 " task: %p, t_fe_count: %d dev: %p\n", task,
313                                 fe_count, dev);
314                         atomic_set(&T_TASK(cmd)->t_transport_aborted, 1);
315                         spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock,
316                                                 flags);
317                         core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
318
319                         spin_lock_irqsave(&dev->execute_task_lock, flags);
320                         continue;
321                 }
322                 DEBUG_LR("LUN_RESET: Got t_transport_active = 0 for task: %p,"
323                         " t_fe_count: %d dev: %p\n", task, fe_count, dev);
324                 atomic_set(&T_TASK(cmd)->t_transport_aborted, 1);
325                 spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock, flags);
326                 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
327
328                 spin_lock_irqsave(&dev->execute_task_lock, flags);
329         }
330         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
331         /*
332          * Release all commands remaining in the struct se_device cmd queue.
333          *
334          * This follows the same logic as above for the struct se_device
335          * struct se_task state list, where commands are returned with
336          * TASK_ABORTED status, if there is an outstanding $FABRIC_MOD
337          * reference, otherwise the struct se_cmd is released.
338          */
339         spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
340         list_for_each_entry_safe(qr, qr_tmp, &qobj->qobj_list, qr_list) {
341                 cmd = (struct se_cmd *)qr->cmd;
342                 if (!(cmd)) {
343                         /*
344                          * Skip these for non PREEMPT_AND_ABORT usage..
345                          */
346                         if (preempt_and_abort_list != NULL)
347                                 continue;
348
349                         atomic_dec(&qobj->queue_cnt);
350                         list_del(&qr->qr_list);
351                         kfree(qr);
352                         continue;
353                 }
354                 /*
355                  * For PREEMPT_AND_ABORT usage, only process commands
356                  * with a matching reservation key.
357                  */
358                 if ((preempt_and_abort_list != NULL) &&
359                     (core_scsi3_check_cdb_abort_and_preempt(
360                                         preempt_and_abort_list, cmd) != 0))
361                         continue;
362                 /*
363                  * Not aborting PROUT PREEMPT_AND_ABORT CDB..
364                  */
365                 if (prout_cmd == cmd)
366                         continue;
367
368                 atomic_dec(&T_TASK(cmd)->t_transport_queue_active);
369                 atomic_dec(&qobj->queue_cnt);
370                 list_del(&qr->qr_list);
371                 spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
372
373                 state = qr->state;
374                 kfree(qr);
375
376                 DEBUG_LR("LUN_RESET: %s from Device Queue: cmd: %p t_state:"
377                         " %d t_fe_count: %d\n", (preempt_and_abort_list) ?
378                         "Preempt" : "", cmd, state,
379                         atomic_read(&T_TASK(cmd)->t_fe_count));
380                 /*
381                  * Signal that the command has failed via cmd->se_cmd_flags,
382                  * and call TFO->new_cmd_failure() to wakeup any fabric
383                  * dependent code used to wait for unsolicited data out
384                  * allocation to complete.  The fabric module is expected
385                  * to dump any remaining unsolicited data out for the aborted
386                  * command at this point.
387                  */
388                 transport_new_cmd_failure(cmd);
389
390                 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas,
391                                 atomic_read(&T_TASK(cmd)->t_fe_count));
392                 spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
393         }
394         spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
395         /*
396          * Clear any legacy SPC-2 reservation when called during
397          * LOGICAL UNIT RESET
398          */
399         if (!(preempt_and_abort_list) &&
400              (dev->dev_flags & DF_SPC2_RESERVATIONS)) {
401                 spin_lock(&dev->dev_reservation_lock);
402                 dev->dev_reserved_node_acl = NULL;
403                 dev->dev_flags &= ~DF_SPC2_RESERVATIONS;
404                 spin_unlock(&dev->dev_reservation_lock);
405                 printk(KERN_INFO "LUN_RESET: SCSI-2 Released reservation\n");
406         }
407
408         spin_lock_irq(&dev->stats_lock);
409         dev->num_resets++;
410         spin_unlock_irq(&dev->stats_lock);
411
412         DEBUG_LR("LUN_RESET: %s for [%s] Complete\n",
413                         (preempt_and_abort_list) ? "Preempt" : "TMR",
414                         TRANSPORT(dev)->name);
415         return 0;
416 }