xref: /linux/drivers/target/target_core_tmr.c (revision 12871a0bd67dd4db4418e1daafcd46e9d329ef10)
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 	spin_lock(&dev->se_tmr_lock);
79 	list_del(&tmr->tmr_list);
80 	kmem_cache_free(se_tmr_req_cache, tmr);
81 	spin_unlock(&dev->se_tmr_lock);
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 != NULL) &&
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 int core_tmr_lun_reset(
105 	struct se_device *dev,
106 	struct se_tmr_req *tmr,
107 	struct list_head *preempt_and_abort_list,
108 	struct se_cmd *prout_cmd)
109 {
110 	struct se_cmd *cmd;
111 	struct se_queue_req *qr, *qr_tmp;
112 	struct se_node_acl *tmr_nacl = NULL;
113 	struct se_portal_group *tmr_tpg = NULL;
114 	struct se_queue_obj *qobj = dev->dev_queue_obj;
115 	struct se_tmr_req *tmr_p, *tmr_pp;
116 	struct se_task *task, *task_tmp;
117 	unsigned long flags;
118 	int fe_count, state, tas;
119 	/*
120 	 * TASK_ABORTED status bit, this is configurable via ConfigFS
121 	 * struct se_device attributes.  spc4r17 section 7.4.6 Control mode page
122 	 *
123 	 * A task aborted status (TAS) bit set to zero specifies that aborted
124 	 * tasks shall be terminated by the device server without any response
125 	 * to the application client. A TAS bit set to one specifies that tasks
126 	 * aborted by the actions of an I_T nexus other than the I_T nexus on
127 	 * which the command was received shall be completed with TASK ABORTED
128 	 * status (see SAM-4).
129 	 */
130 	tas = DEV_ATTRIB(dev)->emulate_tas;
131 	/*
132 	 * Determine if this se_tmr is coming from a $FABRIC_MOD
133 	 * or struct se_device passthrough..
134 	 */
135 	if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) {
136 		tmr_nacl = tmr->task_cmd->se_sess->se_node_acl;
137 		tmr_tpg = tmr->task_cmd->se_sess->se_tpg;
138 		if (tmr_nacl && tmr_tpg) {
139 			DEBUG_LR("LUN_RESET: TMR caller fabric: %s"
140 				" initiator port %s\n",
141 				TPG_TFO(tmr_tpg)->get_fabric_name(),
142 				tmr_nacl->initiatorname);
143 		}
144 	}
145 	DEBUG_LR("LUN_RESET: %s starting for [%s], tas: %d\n",
146 		(preempt_and_abort_list) ? "Preempt" : "TMR",
147 		TRANSPORT(dev)->name, tas);
148 	/*
149 	 * Release all pending and outgoing TMRs aside from the received
150 	 * LUN_RESET tmr..
151 	 */
152 	spin_lock(&dev->se_tmr_lock);
153 	list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) {
154 		/*
155 		 * Allow the received TMR to return with FUNCTION_COMPLETE.
156 		 */
157 		if (tmr && (tmr_p == tmr))
158 			continue;
159 
160 		cmd = tmr_p->task_cmd;
161 		if (!(cmd)) {
162 			printk(KERN_ERR "Unable to locate struct se_cmd for TMR\n");
163 			continue;
164 		}
165 		/*
166 		 * If this function was called with a valid pr_res_key
167 		 * parameter (eg: for PROUT PREEMPT_AND_ABORT service action
168 		 * skip non regisration key matching TMRs.
169 		 */
170 		if ((preempt_and_abort_list != NULL) &&
171 		    (core_scsi3_check_cdb_abort_and_preempt(
172 					preempt_and_abort_list, cmd) != 0))
173 			continue;
174 		spin_unlock(&dev->se_tmr_lock);
175 
176 		spin_lock_irqsave(&T_TASK(cmd)->t_state_lock, flags);
177 		if (!(atomic_read(&T_TASK(cmd)->t_transport_active))) {
178 			spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock, flags);
179 			spin_lock(&dev->se_tmr_lock);
180 			continue;
181 		}
182 		if (cmd->t_state == TRANSPORT_ISTATE_PROCESSING) {
183 			spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock, flags);
184 			spin_lock(&dev->se_tmr_lock);
185 			continue;
186 		}
187 		DEBUG_LR("LUN_RESET: %s releasing TMR %p Function: 0x%02x,"
188 			" Response: 0x%02x, t_state: %d\n",
189 			(preempt_and_abort_list) ? "Preempt" : "", tmr_p,
190 			tmr_p->function, tmr_p->response, cmd->t_state);
191 		spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock, flags);
192 
193 		transport_cmd_finish_abort_tmr(cmd);
194 		spin_lock(&dev->se_tmr_lock);
195 	}
196 	spin_unlock(&dev->se_tmr_lock);
197 	/*
198 	 * Complete outstanding struct se_task CDBs with TASK_ABORTED SAM status.
199 	 * This is following sam4r17, section 5.6 Aborting commands, Table 38
200 	 * for TMR LUN_RESET:
201 	 *
202 	 * a) "Yes" indicates that each command that is aborted on an I_T nexus
203 	 * other than the one that caused the SCSI device condition is
204 	 * completed with TASK ABORTED status, if the TAS bit is set to one in
205 	 * the Control mode page (see SPC-4). "No" indicates that no status is
206 	 * returned for aborted commands.
207 	 *
208 	 * d) If the logical unit reset is caused by a particular I_T nexus
209 	 * (e.g., by a LOGICAL UNIT RESET task management function), then "yes"
210 	 * (TASK_ABORTED status) applies.
211 	 *
212 	 * Otherwise (e.g., if triggered by a hard reset), "no"
213 	 * (no TASK_ABORTED SAM status) applies.
214 	 *
215 	 * Note that this seems to be independent of TAS (Task Aborted Status)
216 	 * in the Control Mode Page.
217 	 */
218 	spin_lock_irqsave(&dev->execute_task_lock, flags);
219 	list_for_each_entry_safe(task, task_tmp, &dev->state_task_list,
220 				t_state_list) {
221 		if (!(TASK_CMD(task))) {
222 			printk(KERN_ERR "TASK_CMD(task) is NULL!\n");
223 			continue;
224 		}
225 		cmd = TASK_CMD(task);
226 
227 		if (!T_TASK(cmd)) {
228 			printk(KERN_ERR "T_TASK(cmd) is NULL for task: %p cmd:"
229 				" %p ITT: 0x%08x\n", task, cmd,
230 				CMD_TFO(cmd)->get_task_tag(cmd));
231 			continue;
232 		}
233 		/*
234 		 * For PREEMPT_AND_ABORT usage, only process commands
235 		 * with a matching reservation key.
236 		 */
237 		if ((preempt_and_abort_list != NULL) &&
238 		    (core_scsi3_check_cdb_abort_and_preempt(
239 					preempt_and_abort_list, cmd) != 0))
240 			continue;
241 		/*
242 		 * Not aborting PROUT PREEMPT_AND_ABORT CDB..
243 		 */
244 		if (prout_cmd == cmd)
245 			continue;
246 
247 		list_del(&task->t_state_list);
248 		atomic_set(&task->task_state_active, 0);
249 		spin_unlock_irqrestore(&dev->execute_task_lock, flags);
250 
251 		spin_lock_irqsave(&T_TASK(cmd)->t_state_lock, flags);
252 		DEBUG_LR("LUN_RESET: %s cmd: %p task: %p"
253 			" ITT/CmdSN: 0x%08x/0x%08x, i_state: %d, t_state/"
254 			"def_t_state: %d/%d cdb: 0x%02x\n",
255 			(preempt_and_abort_list) ? "Preempt" : "", cmd, task,
256 			CMD_TFO(cmd)->get_task_tag(cmd), 0,
257 			CMD_TFO(cmd)->get_cmd_state(cmd), cmd->t_state,
258 			cmd->deferred_t_state, T_TASK(cmd)->t_task_cdb[0]);
259 		DEBUG_LR("LUN_RESET: ITT[0x%08x] - pr_res_key: 0x%016Lx"
260 			" t_task_cdbs: %d t_task_cdbs_left: %d"
261 			" t_task_cdbs_sent: %d -- t_transport_active: %d"
262 			" t_transport_stop: %d t_transport_sent: %d\n",
263 			CMD_TFO(cmd)->get_task_tag(cmd), cmd->pr_res_key,
264 			T_TASK(cmd)->t_task_cdbs,
265 			atomic_read(&T_TASK(cmd)->t_task_cdbs_left),
266 			atomic_read(&T_TASK(cmd)->t_task_cdbs_sent),
267 			atomic_read(&T_TASK(cmd)->t_transport_active),
268 			atomic_read(&T_TASK(cmd)->t_transport_stop),
269 			atomic_read(&T_TASK(cmd)->t_transport_sent));
270 
271 		if (atomic_read(&task->task_active)) {
272 			atomic_set(&task->task_stop, 1);
273 			spin_unlock_irqrestore(
274 				&T_TASK(cmd)->t_state_lock, flags);
275 
276 			DEBUG_LR("LUN_RESET: Waiting for task: %p to shutdown"
277 				" for dev: %p\n", task, dev);
278 			wait_for_completion(&task->task_stop_comp);
279 			DEBUG_LR("LUN_RESET Completed task: %p shutdown for"
280 				" dev: %p\n", task, dev);
281 			spin_lock_irqsave(&T_TASK(cmd)->t_state_lock, flags);
282 			atomic_dec(&T_TASK(cmd)->t_task_cdbs_left);
283 
284 			atomic_set(&task->task_active, 0);
285 			atomic_set(&task->task_stop, 0);
286 		} else {
287 			if (atomic_read(&task->task_execute_queue) != 0)
288 				transport_remove_task_from_execute_queue(task, dev);
289 		}
290 		__transport_stop_task_timer(task, &flags);
291 
292 		if (!(atomic_dec_and_test(&T_TASK(cmd)->t_task_cdbs_ex_left))) {
293 			spin_unlock_irqrestore(
294 					&T_TASK(cmd)->t_state_lock, flags);
295 			DEBUG_LR("LUN_RESET: Skipping task: %p, dev: %p for"
296 				" t_task_cdbs_ex_left: %d\n", task, dev,
297 				atomic_read(&T_TASK(cmd)->t_task_cdbs_ex_left));
298 
299 			spin_lock_irqsave(&dev->execute_task_lock, flags);
300 			continue;
301 		}
302 		fe_count = atomic_read(&T_TASK(cmd)->t_fe_count);
303 
304 		if (atomic_read(&T_TASK(cmd)->t_transport_active)) {
305 			DEBUG_LR("LUN_RESET: got t_transport_active = 1 for"
306 				" task: %p, t_fe_count: %d dev: %p\n", task,
307 				fe_count, dev);
308 			atomic_set(&T_TASK(cmd)->t_transport_aborted, 1);
309 			spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock,
310 						flags);
311 			core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
312 
313 			spin_lock_irqsave(&dev->execute_task_lock, flags);
314 			continue;
315 		}
316 		DEBUG_LR("LUN_RESET: Got t_transport_active = 0 for task: %p,"
317 			" t_fe_count: %d dev: %p\n", task, fe_count, dev);
318 		atomic_set(&T_TASK(cmd)->t_transport_aborted, 1);
319 		spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock, flags);
320 		core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
321 
322 		spin_lock_irqsave(&dev->execute_task_lock, flags);
323 	}
324 	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
325 	/*
326 	 * Release all commands remaining in the struct se_device cmd queue.
327 	 *
328 	 * This follows the same logic as above for the struct se_device
329 	 * struct se_task state list, where commands are returned with
330 	 * TASK_ABORTED status, if there is an outstanding $FABRIC_MOD
331 	 * reference, otherwise the struct se_cmd is released.
332 	 */
333 	spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
334 	list_for_each_entry_safe(qr, qr_tmp, &qobj->qobj_list, qr_list) {
335 		cmd = (struct se_cmd *)qr->cmd;
336 		if (!(cmd)) {
337 			/*
338 			 * Skip these for non PREEMPT_AND_ABORT usage..
339 			 */
340 			if (preempt_and_abort_list != NULL)
341 				continue;
342 
343 			atomic_dec(&qobj->queue_cnt);
344 			list_del(&qr->qr_list);
345 			kfree(qr);
346 			continue;
347 		}
348 		/*
349 		 * For PREEMPT_AND_ABORT usage, only process commands
350 		 * with a matching reservation key.
351 		 */
352 		if ((preempt_and_abort_list != NULL) &&
353 		    (core_scsi3_check_cdb_abort_and_preempt(
354 					preempt_and_abort_list, cmd) != 0))
355 			continue;
356 		/*
357 		 * Not aborting PROUT PREEMPT_AND_ABORT CDB..
358 		 */
359 		if (prout_cmd == cmd)
360 			continue;
361 
362 		atomic_dec(&T_TASK(cmd)->t_transport_queue_active);
363 		atomic_dec(&qobj->queue_cnt);
364 		list_del(&qr->qr_list);
365 		spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
366 
367 		state = qr->state;
368 		kfree(qr);
369 
370 		DEBUG_LR("LUN_RESET: %s from Device Queue: cmd: %p t_state:"
371 			" %d t_fe_count: %d\n", (preempt_and_abort_list) ?
372 			"Preempt" : "", cmd, state,
373 			atomic_read(&T_TASK(cmd)->t_fe_count));
374 		/*
375 		 * Signal that the command has failed via cmd->se_cmd_flags,
376 		 * and call TFO->new_cmd_failure() to wakeup any fabric
377 		 * dependent code used to wait for unsolicited data out
378 		 * allocation to complete.  The fabric module is expected
379 		 * to dump any remaining unsolicited data out for the aborted
380 		 * command at this point.
381 		 */
382 		transport_new_cmd_failure(cmd);
383 
384 		core_tmr_handle_tas_abort(tmr_nacl, cmd, tas,
385 				atomic_read(&T_TASK(cmd)->t_fe_count));
386 		spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
387 	}
388 	spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
389 	/*
390 	 * Clear any legacy SPC-2 reservation when called during
391 	 * LOGICAL UNIT RESET
392 	 */
393 	if (!(preempt_and_abort_list) &&
394 	     (dev->dev_flags & DF_SPC2_RESERVATIONS)) {
395 		spin_lock(&dev->dev_reservation_lock);
396 		dev->dev_reserved_node_acl = NULL;
397 		dev->dev_flags &= ~DF_SPC2_RESERVATIONS;
398 		spin_unlock(&dev->dev_reservation_lock);
399 		printk(KERN_INFO "LUN_RESET: SCSI-2 Released reservation\n");
400 	}
401 
402 	spin_lock_irq(&dev->stats_lock);
403 	dev->num_resets++;
404 	spin_unlock_irq(&dev->stats_lock);
405 
406 	DEBUG_LR("LUN_RESET: %s for [%s] Complete\n",
407 			(preempt_and_abort_list) ? "Preempt" : "TMR",
408 			TRANSPORT(dev)->name);
409 	return 0;
410 }
411