xref: /linux/drivers/target/target_core_tmr.c (revision 98f4a2c27c76e7eaf75c2f3f25487fabca62ef3d)
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 }
417