xref: /openbmc/linux/drivers/target/target_core_tmr.c (revision df2634f43f5106947f3735a0b61a6527a4b278cd)
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 		}
286 		__transport_stop_task_timer(task, &flags);
287 
288 		if (!(atomic_dec_and_test(&T_TASK(cmd)->t_task_cdbs_ex_left))) {
289 			spin_unlock_irqrestore(
290 					&T_TASK(cmd)->t_state_lock, flags);
291 			DEBUG_LR("LUN_RESET: Skipping task: %p, dev: %p for"
292 				" t_task_cdbs_ex_left: %d\n", task, dev,
293 				atomic_read(&T_TASK(cmd)->t_task_cdbs_ex_left));
294 
295 			spin_lock_irqsave(&dev->execute_task_lock, flags);
296 			continue;
297 		}
298 		fe_count = atomic_read(&T_TASK(cmd)->t_fe_count);
299 
300 		if (atomic_read(&T_TASK(cmd)->t_transport_active)) {
301 			DEBUG_LR("LUN_RESET: got t_transport_active = 1 for"
302 				" task: %p, t_fe_count: %d dev: %p\n", task,
303 				fe_count, dev);
304 			spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock,
305 						flags);
306 			core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
307 
308 			spin_lock_irqsave(&dev->execute_task_lock, flags);
309 			continue;
310 		}
311 		DEBUG_LR("LUN_RESET: Got t_transport_active = 0 for task: %p,"
312 			" t_fe_count: %d dev: %p\n", task, fe_count, dev);
313 		spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock, flags);
314 		core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
315 
316 		spin_lock_irqsave(&dev->execute_task_lock, flags);
317 	}
318 	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
319 	/*
320 	 * Release all commands remaining in the struct se_device cmd queue.
321 	 *
322 	 * This follows the same logic as above for the struct se_device
323 	 * struct se_task state list, where commands are returned with
324 	 * TASK_ABORTED status, if there is an outstanding $FABRIC_MOD
325 	 * reference, otherwise the struct se_cmd is released.
326 	 */
327 	spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
328 	list_for_each_entry_safe(qr, qr_tmp, &qobj->qobj_list, qr_list) {
329 		cmd = (struct se_cmd *)qr->cmd;
330 		if (!(cmd)) {
331 			/*
332 			 * Skip these for non PREEMPT_AND_ABORT usage..
333 			 */
334 			if (preempt_and_abort_list != NULL)
335 				continue;
336 
337 			atomic_dec(&qobj->queue_cnt);
338 			list_del(&qr->qr_list);
339 			kfree(qr);
340 			continue;
341 		}
342 		/*
343 		 * For PREEMPT_AND_ABORT usage, only process commands
344 		 * with a matching reservation key.
345 		 */
346 		if ((preempt_and_abort_list != NULL) &&
347 		    (core_scsi3_check_cdb_abort_and_preempt(
348 					preempt_and_abort_list, cmd) != 0))
349 			continue;
350 		/*
351 		 * Not aborting PROUT PREEMPT_AND_ABORT CDB..
352 		 */
353 		if (prout_cmd == cmd)
354 			continue;
355 
356 		atomic_dec(&T_TASK(cmd)->t_transport_queue_active);
357 		atomic_dec(&qobj->queue_cnt);
358 		list_del(&qr->qr_list);
359 		spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
360 
361 		state = qr->state;
362 		kfree(qr);
363 
364 		DEBUG_LR("LUN_RESET: %s from Device Queue: cmd: %p t_state:"
365 			" %d t_fe_count: %d\n", (preempt_and_abort_list) ?
366 			"Preempt" : "", cmd, state,
367 			atomic_read(&T_TASK(cmd)->t_fe_count));
368 		/*
369 		 * Signal that the command has failed via cmd->se_cmd_flags,
370 		 * and call TFO->new_cmd_failure() to wakeup any fabric
371 		 * dependent code used to wait for unsolicited data out
372 		 * allocation to complete.  The fabric module is expected
373 		 * to dump any remaining unsolicited data out for the aborted
374 		 * command at this point.
375 		 */
376 		transport_new_cmd_failure(cmd);
377 
378 		core_tmr_handle_tas_abort(tmr_nacl, cmd, tas,
379 				atomic_read(&T_TASK(cmd)->t_fe_count));
380 		spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
381 	}
382 	spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
383 	/*
384 	 * Clear any legacy SPC-2 reservation when called during
385 	 * LOGICAL UNIT RESET
386 	 */
387 	if (!(preempt_and_abort_list) &&
388 	     (dev->dev_flags & DF_SPC2_RESERVATIONS)) {
389 		spin_lock(&dev->dev_reservation_lock);
390 		dev->dev_reserved_node_acl = NULL;
391 		dev->dev_flags &= ~DF_SPC2_RESERVATIONS;
392 		spin_unlock(&dev->dev_reservation_lock);
393 		printk(KERN_INFO "LUN_RESET: SCSI-2 Released reservation\n");
394 	}
395 
396 	spin_lock(&dev->stats_lock);
397 	dev->num_resets++;
398 	spin_unlock(&dev->stats_lock);
399 
400 	DEBUG_LR("LUN_RESET: %s for [%s] Complete\n",
401 			(preempt_and_abort_list) ? "Preempt" : "TMR",
402 			TRANSPORT(dev)->name);
403 	return 0;
404 }
405