xref: /linux/drivers/target/target_core_tmr.c (revision 1ccd4b7bfdcfcc8cc7ffc4a9c11d3ac5b6da8ca0)
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 struct se_tmr_req *core_tmr_alloc_req(
45 	struct se_cmd *se_cmd,
46 	void *fabric_tmr_ptr,
47 	u8 function)
48 {
49 	struct se_tmr_req *tmr;
50 
51 	tmr = kmem_cache_zalloc(se_tmr_req_cache, (in_interrupt()) ?
52 					GFP_ATOMIC : GFP_KERNEL);
53 	if (!tmr) {
54 		pr_err("Unable to allocate struct se_tmr_req\n");
55 		return ERR_PTR(-ENOMEM);
56 	}
57 	tmr->task_cmd = se_cmd;
58 	tmr->fabric_tmr_ptr = fabric_tmr_ptr;
59 	tmr->function = function;
60 	INIT_LIST_HEAD(&tmr->tmr_list);
61 
62 	return tmr;
63 }
64 EXPORT_SYMBOL(core_tmr_alloc_req);
65 
66 void core_tmr_release_req(
67 	struct se_tmr_req *tmr)
68 {
69 	struct se_device *dev = tmr->tmr_dev;
70 
71 	if (!dev) {
72 		kmem_cache_free(se_tmr_req_cache, tmr);
73 		return;
74 	}
75 
76 	spin_lock_irq(&dev->se_tmr_lock);
77 	list_del(&tmr->tmr_list);
78 	spin_unlock_irq(&dev->se_tmr_lock);
79 
80 	kmem_cache_free(se_tmr_req_cache, tmr);
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 &&
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, *tcmd;
110 	struct se_node_acl *tmr_nacl = NULL;
111 	struct se_portal_group *tmr_tpg = NULL;
112 	struct se_queue_obj *qobj = &dev->dev_queue_obj;
113 	struct se_tmr_req *tmr_p, *tmr_pp;
114 	struct se_task *task, *task_tmp;
115 	unsigned long flags;
116 	int fe_count, tas;
117 	/*
118 	 * TASK_ABORTED status bit, this is configurable via ConfigFS
119 	 * struct se_device attributes.  spc4r17 section 7.4.6 Control mode page
120 	 *
121 	 * A task aborted status (TAS) bit set to zero specifies that aborted
122 	 * tasks shall be terminated by the device server without any response
123 	 * to the application client. A TAS bit set to one specifies that tasks
124 	 * aborted by the actions of an I_T nexus other than the I_T nexus on
125 	 * which the command was received shall be completed with TASK ABORTED
126 	 * status (see SAM-4).
127 	 */
128 	tas = dev->se_sub_dev->se_dev_attrib.emulate_tas;
129 	/*
130 	 * Determine if this se_tmr is coming from a $FABRIC_MOD
131 	 * or struct se_device passthrough..
132 	 */
133 	if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) {
134 		tmr_nacl = tmr->task_cmd->se_sess->se_node_acl;
135 		tmr_tpg = tmr->task_cmd->se_sess->se_tpg;
136 		if (tmr_nacl && tmr_tpg) {
137 			pr_debug("LUN_RESET: TMR caller fabric: %s"
138 				" initiator port %s\n",
139 				tmr_tpg->se_tpg_tfo->get_fabric_name(),
140 				tmr_nacl->initiatorname);
141 		}
142 	}
143 	pr_debug("LUN_RESET: %s starting for [%s], tas: %d\n",
144 		(preempt_and_abort_list) ? "Preempt" : "TMR",
145 		dev->transport->name, tas);
146 	/*
147 	 * Release all pending and outgoing TMRs aside from the received
148 	 * LUN_RESET tmr..
149 	 */
150 	spin_lock_irq(&dev->se_tmr_lock);
151 	list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) {
152 		/*
153 		 * Allow the received TMR to return with FUNCTION_COMPLETE.
154 		 */
155 		if (tmr && (tmr_p == tmr))
156 			continue;
157 
158 		cmd = tmr_p->task_cmd;
159 		if (!cmd) {
160 			pr_err("Unable to locate struct se_cmd for TMR\n");
161 			continue;
162 		}
163 		/*
164 		 * If this function was called with a valid pr_res_key
165 		 * parameter (eg: for PROUT PREEMPT_AND_ABORT service action
166 		 * skip non regisration key matching TMRs.
167 		 */
168 		if (preempt_and_abort_list &&
169 		    (core_scsi3_check_cdb_abort_and_preempt(
170 					preempt_and_abort_list, cmd) != 0))
171 			continue;
172 		spin_unlock_irq(&dev->se_tmr_lock);
173 
174 		spin_lock_irqsave(&cmd->t_state_lock, flags);
175 		if (!atomic_read(&cmd->t_transport_active)) {
176 			spin_unlock_irqrestore(&cmd->t_state_lock, flags);
177 			spin_lock_irq(&dev->se_tmr_lock);
178 			continue;
179 		}
180 		if (cmd->t_state == TRANSPORT_ISTATE_PROCESSING) {
181 			spin_unlock_irqrestore(&cmd->t_state_lock, flags);
182 			spin_lock_irq(&dev->se_tmr_lock);
183 			continue;
184 		}
185 		pr_debug("LUN_RESET: %s releasing TMR %p Function: 0x%02x,"
186 			" Response: 0x%02x, t_state: %d\n",
187 			(preempt_and_abort_list) ? "Preempt" : "", tmr_p,
188 			tmr_p->function, tmr_p->response, cmd->t_state);
189 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
190 
191 		transport_cmd_finish_abort_tmr(cmd);
192 		spin_lock_irq(&dev->se_tmr_lock);
193 	}
194 	spin_unlock_irq(&dev->se_tmr_lock);
195 	/*
196 	 * Complete outstanding struct se_task CDBs with TASK_ABORTED SAM status.
197 	 * This is following sam4r17, section 5.6 Aborting commands, Table 38
198 	 * for TMR LUN_RESET:
199 	 *
200 	 * a) "Yes" indicates that each command that is aborted on an I_T nexus
201 	 * other than the one that caused the SCSI device condition is
202 	 * completed with TASK ABORTED status, if the TAS bit is set to one in
203 	 * the Control mode page (see SPC-4). "No" indicates that no status is
204 	 * returned for aborted commands.
205 	 *
206 	 * d) If the logical unit reset is caused by a particular I_T nexus
207 	 * (e.g., by a LOGICAL UNIT RESET task management function), then "yes"
208 	 * (TASK_ABORTED status) applies.
209 	 *
210 	 * Otherwise (e.g., if triggered by a hard reset), "no"
211 	 * (no TASK_ABORTED SAM status) applies.
212 	 *
213 	 * Note that this seems to be independent of TAS (Task Aborted Status)
214 	 * in the Control Mode Page.
215 	 */
216 	spin_lock_irqsave(&dev->execute_task_lock, flags);
217 	list_for_each_entry_safe(task, task_tmp, &dev->state_task_list,
218 				t_state_list) {
219 		if (!task->task_se_cmd) {
220 			pr_err("task->task_se_cmd is NULL!\n");
221 			continue;
222 		}
223 		cmd = task->task_se_cmd;
224 
225 		/*
226 		 * For PREEMPT_AND_ABORT usage, only process commands
227 		 * with a matching reservation key.
228 		 */
229 		if (preempt_and_abort_list &&
230 		    (core_scsi3_check_cdb_abort_and_preempt(
231 					preempt_and_abort_list, cmd) != 0))
232 			continue;
233 		/*
234 		 * Not aborting PROUT PREEMPT_AND_ABORT CDB..
235 		 */
236 		if (prout_cmd == cmd)
237 			continue;
238 
239 		list_del(&task->t_state_list);
240 		atomic_set(&task->task_state_active, 0);
241 		spin_unlock_irqrestore(&dev->execute_task_lock, flags);
242 
243 		spin_lock_irqsave(&cmd->t_state_lock, flags);
244 		pr_debug("LUN_RESET: %s cmd: %p task: %p"
245 			" ITT/CmdSN: 0x%08x/0x%08x, i_state: %d, t_state/"
246 			"def_t_state: %d/%d cdb: 0x%02x\n",
247 			(preempt_and_abort_list) ? "Preempt" : "", cmd, task,
248 			cmd->se_tfo->get_task_tag(cmd), 0,
249 			cmd->se_tfo->get_cmd_state(cmd), cmd->t_state,
250 			cmd->deferred_t_state, cmd->t_task_cdb[0]);
251 		pr_debug("LUN_RESET: ITT[0x%08x] - pr_res_key: 0x%016Lx"
252 			" t_task_cdbs: %d t_task_cdbs_left: %d"
253 			" t_task_cdbs_sent: %d -- t_transport_active: %d"
254 			" t_transport_stop: %d t_transport_sent: %d\n",
255 			cmd->se_tfo->get_task_tag(cmd), cmd->pr_res_key,
256 			cmd->t_task_list_num,
257 			atomic_read(&cmd->t_task_cdbs_left),
258 			atomic_read(&cmd->t_task_cdbs_sent),
259 			atomic_read(&cmd->t_transport_active),
260 			atomic_read(&cmd->t_transport_stop),
261 			atomic_read(&cmd->t_transport_sent));
262 
263 		if (atomic_read(&task->task_active)) {
264 			atomic_set(&task->task_stop, 1);
265 			spin_unlock_irqrestore(
266 				&cmd->t_state_lock, flags);
267 
268 			pr_debug("LUN_RESET: Waiting for task: %p to shutdown"
269 				" for dev: %p\n", task, dev);
270 			wait_for_completion(&task->task_stop_comp);
271 			pr_debug("LUN_RESET Completed task: %p shutdown for"
272 				" dev: %p\n", task, dev);
273 			spin_lock_irqsave(&cmd->t_state_lock, flags);
274 			atomic_dec(&cmd->t_task_cdbs_left);
275 
276 			atomic_set(&task->task_active, 0);
277 			atomic_set(&task->task_stop, 0);
278 		} else {
279 			if (atomic_read(&task->task_execute_queue) != 0)
280 				transport_remove_task_from_execute_queue(task, dev);
281 		}
282 		__transport_stop_task_timer(task, &flags);
283 
284 		if (!atomic_dec_and_test(&cmd->t_task_cdbs_ex_left)) {
285 			spin_unlock_irqrestore(
286 					&cmd->t_state_lock, flags);
287 			pr_debug("LUN_RESET: Skipping task: %p, dev: %p for"
288 				" t_task_cdbs_ex_left: %d\n", task, dev,
289 				atomic_read(&cmd->t_task_cdbs_ex_left));
290 
291 			spin_lock_irqsave(&dev->execute_task_lock, flags);
292 			continue;
293 		}
294 		fe_count = atomic_read(&cmd->t_fe_count);
295 
296 		if (atomic_read(&cmd->t_transport_active)) {
297 			pr_debug("LUN_RESET: got t_transport_active = 1 for"
298 				" task: %p, t_fe_count: %d dev: %p\n", task,
299 				fe_count, dev);
300 			atomic_set(&cmd->t_transport_aborted, 1);
301 			spin_unlock_irqrestore(&cmd->t_state_lock,
302 						flags);
303 			core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
304 
305 			spin_lock_irqsave(&dev->execute_task_lock, flags);
306 			continue;
307 		}
308 		pr_debug("LUN_RESET: Got t_transport_active = 0 for task: %p,"
309 			" t_fe_count: %d dev: %p\n", task, fe_count, dev);
310 		atomic_set(&cmd->t_transport_aborted, 1);
311 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
312 		core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
313 
314 		spin_lock_irqsave(&dev->execute_task_lock, flags);
315 	}
316 	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
317 	/*
318 	 * Release all commands remaining in the struct se_device cmd queue.
319 	 *
320 	 * This follows the same logic as above for the struct se_device
321 	 * struct se_task state list, where commands are returned with
322 	 * TASK_ABORTED status, if there is an outstanding $FABRIC_MOD
323 	 * reference, otherwise the struct se_cmd is released.
324 	 */
325 	spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
326 	list_for_each_entry_safe(cmd, tcmd, &qobj->qobj_list, se_queue_node) {
327 		/*
328 		 * For PREEMPT_AND_ABORT usage, only process commands
329 		 * with a matching reservation key.
330 		 */
331 		if (preempt_and_abort_list &&
332 		    (core_scsi3_check_cdb_abort_and_preempt(
333 					preempt_and_abort_list, cmd) != 0))
334 			continue;
335 		/*
336 		 * Not aborting PROUT PREEMPT_AND_ABORT CDB..
337 		 */
338 		if (prout_cmd == cmd)
339 			continue;
340 
341 		atomic_dec(&cmd->t_transport_queue_active);
342 		atomic_dec(&qobj->queue_cnt);
343 		list_del(&cmd->se_queue_node);
344 		spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
345 
346 		pr_debug("LUN_RESET: %s from Device Queue: cmd: %p t_state:"
347 			" %d t_fe_count: %d\n", (preempt_and_abort_list) ?
348 			"Preempt" : "", cmd, cmd->t_state,
349 			atomic_read(&cmd->t_fe_count));
350 		/*
351 		 * Signal that the command has failed via cmd->se_cmd_flags,
352 		 */
353 		transport_new_cmd_failure(cmd);
354 
355 		core_tmr_handle_tas_abort(tmr_nacl, cmd, tas,
356 				atomic_read(&cmd->t_fe_count));
357 		spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
358 	}
359 	spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
360 	/*
361 	 * Clear any legacy SPC-2 reservation when called during
362 	 * LOGICAL UNIT RESET
363 	 */
364 	if (!preempt_and_abort_list &&
365 	     (dev->dev_flags & DF_SPC2_RESERVATIONS)) {
366 		spin_lock(&dev->dev_reservation_lock);
367 		dev->dev_reserved_node_acl = NULL;
368 		dev->dev_flags &= ~DF_SPC2_RESERVATIONS;
369 		spin_unlock(&dev->dev_reservation_lock);
370 		pr_debug("LUN_RESET: SCSI-2 Released reservation\n");
371 	}
372 
373 	spin_lock_irq(&dev->stats_lock);
374 	dev->num_resets++;
375 	spin_unlock_irq(&dev->stats_lock);
376 
377 	pr_debug("LUN_RESET: %s for [%s] Complete\n",
378 			(preempt_and_abort_list) ? "Preempt" : "TMR",
379 			dev->transport->name);
380 	return 0;
381 }
382