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1 | // SPDX-License-Identifier: GPL-2.0-or-later | |
2 | /******************************************************************************* | |
3 | * Filename: target_core_tmr.c | |
4 | * | |
5 | * This file contains SPC-3 task management infrastructure | |
6 | * | |
7 | * (c) Copyright 2009-2013 Datera, Inc. | |
8 | * | |
9 | * Nicholas A. Bellinger <nab@kernel.org> | |
10 | * | |
11 | ******************************************************************************/ | |
12 | ||
13 | #include <linux/slab.h> | |
14 | #include <linux/spinlock.h> | |
15 | #include <linux/list.h> | |
16 | #include <linux/export.h> | |
17 | ||
18 | #include <target/target_core_base.h> | |
19 | #include <target/target_core_backend.h> | |
20 | #include <target/target_core_fabric.h> | |
21 | ||
22 | #include "target_core_internal.h" | |
23 | #include "target_core_alua.h" | |
24 | #include "target_core_pr.h" | |
25 | ||
26 | int core_tmr_alloc_req( | |
27 | struct se_cmd *se_cmd, | |
28 | void *fabric_tmr_ptr, | |
29 | u8 function, | |
30 | gfp_t gfp_flags) | |
31 | { | |
32 | struct se_tmr_req *tmr; | |
33 | ||
34 | tmr = kzalloc(sizeof(struct se_tmr_req), gfp_flags); | |
35 | if (!tmr) { | |
36 | pr_err("Unable to allocate struct se_tmr_req\n"); | |
37 | return -ENOMEM; | |
38 | } | |
39 | ||
40 | se_cmd->se_cmd_flags |= SCF_SCSI_TMR_CDB; | |
41 | se_cmd->se_tmr_req = tmr; | |
42 | tmr->task_cmd = se_cmd; | |
43 | tmr->fabric_tmr_ptr = fabric_tmr_ptr; | |
44 | tmr->function = function; | |
45 | INIT_LIST_HEAD(&tmr->tmr_list); | |
46 | ||
47 | return 0; | |
48 | } | |
49 | EXPORT_SYMBOL(core_tmr_alloc_req); | |
50 | ||
51 | void core_tmr_release_req(struct se_tmr_req *tmr) | |
52 | { | |
53 | kfree(tmr); | |
54 | } | |
55 | ||
56 | static int target_check_cdb_and_preempt(struct list_head *list, | |
57 | struct se_cmd *cmd) | |
58 | { | |
59 | struct t10_pr_registration *reg; | |
60 | ||
61 | if (!list) | |
62 | return 0; | |
63 | list_for_each_entry(reg, list, pr_reg_abort_list) { | |
64 | if (reg->pr_res_key == cmd->pr_res_key) | |
65 | return 0; | |
66 | } | |
67 | ||
68 | return 1; | |
69 | } | |
70 | ||
71 | static bool __target_check_io_state(struct se_cmd *se_cmd, | |
72 | struct se_session *tmr_sess, bool tas) | |
73 | { | |
74 | struct se_session *sess = se_cmd->se_sess; | |
75 | ||
76 | assert_spin_locked(&sess->sess_cmd_lock); | |
77 | WARN_ON_ONCE(!irqs_disabled()); | |
78 | /* | |
79 | * If command already reached CMD_T_COMPLETE state within | |
80 | * target_complete_cmd() or CMD_T_FABRIC_STOP due to shutdown, | |
81 | * this se_cmd has been passed to fabric driver and will | |
82 | * not be aborted. | |
83 | * | |
84 | * Otherwise, obtain a local se_cmd->cmd_kref now for TMR | |
85 | * ABORT_TASK + LUN_RESET for CMD_T_ABORTED processing as | |
86 | * long as se_cmd->cmd_kref is still active unless zero. | |
87 | */ | |
88 | spin_lock(&se_cmd->t_state_lock); | |
89 | if (se_cmd->transport_state & (CMD_T_COMPLETE | CMD_T_FABRIC_STOP)) { | |
90 | pr_debug("Attempted to abort io tag: %llu already complete or" | |
91 | " fabric stop, skipping\n", se_cmd->tag); | |
92 | spin_unlock(&se_cmd->t_state_lock); | |
93 | return false; | |
94 | } | |
95 | se_cmd->transport_state |= CMD_T_ABORTED; | |
96 | ||
97 | if ((tmr_sess != se_cmd->se_sess) && tas) | |
98 | se_cmd->transport_state |= CMD_T_TAS; | |
99 | ||
100 | spin_unlock(&se_cmd->t_state_lock); | |
101 | ||
102 | return kref_get_unless_zero(&se_cmd->cmd_kref); | |
103 | } | |
104 | ||
105 | void core_tmr_abort_task( | |
106 | struct se_device *dev, | |
107 | struct se_tmr_req *tmr, | |
108 | struct se_session *se_sess) | |
109 | { | |
110 | LIST_HEAD(aborted_list); | |
111 | struct se_cmd *se_cmd, *next; | |
112 | unsigned long flags; | |
113 | bool rc; | |
114 | u64 ref_tag; | |
115 | int i; | |
116 | ||
117 | for (i = 0; i < dev->queue_cnt; i++) { | |
118 | flush_work(&dev->queues[i].sq.work); | |
119 | ||
120 | spin_lock_irqsave(&dev->queues[i].lock, flags); | |
121 | list_for_each_entry_safe(se_cmd, next, &dev->queues[i].state_list, | |
122 | state_list) { | |
123 | if (se_sess != se_cmd->se_sess) | |
124 | continue; | |
125 | ||
126 | /* | |
127 | * skip task management functions, including | |
128 | * tmr->task_cmd | |
129 | */ | |
130 | if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB) | |
131 | continue; | |
132 | ||
133 | ref_tag = se_cmd->tag; | |
134 | if (tmr->ref_task_tag != ref_tag) | |
135 | continue; | |
136 | ||
137 | pr_err("ABORT_TASK: Found referenced %s task_tag: %llu\n", | |
138 | se_cmd->se_tfo->fabric_name, ref_tag); | |
139 | ||
140 | spin_lock(&se_sess->sess_cmd_lock); | |
141 | rc = __target_check_io_state(se_cmd, se_sess, 0); | |
142 | spin_unlock(&se_sess->sess_cmd_lock); | |
143 | if (!rc) | |
144 | continue; | |
145 | ||
146 | list_move_tail(&se_cmd->state_list, &aborted_list); | |
147 | se_cmd->state_active = false; | |
148 | spin_unlock_irqrestore(&dev->queues[i].lock, flags); | |
149 | ||
150 | if (dev->transport->tmr_notify) | |
151 | dev->transport->tmr_notify(dev, TMR_ABORT_TASK, | |
152 | &aborted_list); | |
153 | ||
154 | list_del_init(&se_cmd->state_list); | |
155 | target_put_cmd_and_wait(se_cmd); | |
156 | ||
157 | pr_err("ABORT_TASK: Sending TMR_FUNCTION_COMPLETE for ref_tag: %llu\n", | |
158 | ref_tag); | |
159 | tmr->response = TMR_FUNCTION_COMPLETE; | |
160 | atomic_long_inc(&dev->aborts_complete); | |
161 | return; | |
162 | } | |
163 | spin_unlock_irqrestore(&dev->queues[i].lock, flags); | |
164 | } | |
165 | ||
166 | if (dev->transport->tmr_notify) | |
167 | dev->transport->tmr_notify(dev, TMR_ABORT_TASK, &aborted_list); | |
168 | ||
169 | printk("ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: %lld\n", | |
170 | tmr->ref_task_tag); | |
171 | tmr->response = TMR_TASK_DOES_NOT_EXIST; | |
172 | atomic_long_inc(&dev->aborts_no_task); | |
173 | } | |
174 | ||
175 | static void core_tmr_drain_tmr_list( | |
176 | struct se_device *dev, | |
177 | struct se_tmr_req *tmr, | |
178 | struct list_head *preempt_and_abort_list) | |
179 | { | |
180 | LIST_HEAD(drain_tmr_list); | |
181 | struct se_session *sess; | |
182 | struct se_tmr_req *tmr_p, *tmr_pp; | |
183 | struct se_cmd *cmd; | |
184 | unsigned long flags; | |
185 | bool rc; | |
186 | /* | |
187 | * Release all pending and outgoing TMRs aside from the received | |
188 | * LUN_RESET tmr.. | |
189 | */ | |
190 | spin_lock_irqsave(&dev->se_tmr_lock, flags); | |
191 | if (tmr) | |
192 | list_del_init(&tmr->tmr_list); | |
193 | list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) { | |
194 | cmd = tmr_p->task_cmd; | |
195 | if (!cmd) { | |
196 | pr_err("Unable to locate struct se_cmd for TMR\n"); | |
197 | continue; | |
198 | } | |
199 | /* | |
200 | * If this function was called with a valid pr_res_key | |
201 | * parameter (eg: for PROUT PREEMPT_AND_ABORT service action | |
202 | * skip non registration key matching TMRs. | |
203 | */ | |
204 | if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd)) | |
205 | continue; | |
206 | ||
207 | sess = cmd->se_sess; | |
208 | if (WARN_ON_ONCE(!sess)) | |
209 | continue; | |
210 | ||
211 | spin_lock(&sess->sess_cmd_lock); | |
212 | rc = __target_check_io_state(cmd, sess, 0); | |
213 | spin_unlock(&sess->sess_cmd_lock); | |
214 | ||
215 | if (!rc) { | |
216 | printk("LUN_RESET TMR: non-zero kref_get_unless_zero\n"); | |
217 | continue; | |
218 | } | |
219 | ||
220 | list_move_tail(&tmr_p->tmr_list, &drain_tmr_list); | |
221 | tmr_p->tmr_dev = NULL; | |
222 | } | |
223 | spin_unlock_irqrestore(&dev->se_tmr_lock, flags); | |
224 | ||
225 | list_for_each_entry_safe(tmr_p, tmr_pp, &drain_tmr_list, tmr_list) { | |
226 | list_del_init(&tmr_p->tmr_list); | |
227 | cmd = tmr_p->task_cmd; | |
228 | ||
229 | pr_debug("LUN_RESET: %s releasing TMR %p Function: 0x%02x," | |
230 | " Response: 0x%02x, t_state: %d\n", | |
231 | (preempt_and_abort_list) ? "Preempt" : "", tmr_p, | |
232 | tmr_p->function, tmr_p->response, cmd->t_state); | |
233 | ||
234 | target_put_cmd_and_wait(cmd); | |
235 | } | |
236 | } | |
237 | ||
238 | /** | |
239 | * core_tmr_drain_state_list() - abort SCSI commands associated with a device | |
240 | * | |
241 | * @dev: Device for which to abort outstanding SCSI commands. | |
242 | * @prout_cmd: Pointer to the SCSI PREEMPT AND ABORT if this function is called | |
243 | * to realize the PREEMPT AND ABORT functionality. | |
244 | * @tmr_sess: Session through which the LUN RESET has been received. | |
245 | * @tas: Task Aborted Status (TAS) bit from the SCSI control mode page. | |
246 | * A quote from SPC-4, paragraph "7.5.10 Control mode page": | |
247 | * "A task aborted status (TAS) bit set to zero specifies that | |
248 | * aborted commands shall be terminated by the device server | |
249 | * without any response to the application client. A TAS bit set | |
250 | * to one specifies that commands aborted by the actions of an I_T | |
251 | * nexus other than the I_T nexus on which the command was | |
252 | * received shall be completed with TASK ABORTED status." | |
253 | * @preempt_and_abort_list: For the PREEMPT AND ABORT functionality, a list | |
254 | * with registrations that will be preempted. | |
255 | */ | |
256 | static void core_tmr_drain_state_list( | |
257 | struct se_device *dev, | |
258 | struct se_cmd *prout_cmd, | |
259 | struct se_session *tmr_sess, | |
260 | bool tas, | |
261 | struct list_head *preempt_and_abort_list) | |
262 | { | |
263 | LIST_HEAD(drain_task_list); | |
264 | struct se_session *sess; | |
265 | struct se_cmd *cmd, *next; | |
266 | unsigned long flags; | |
267 | int rc, i; | |
268 | ||
269 | /* | |
270 | * Complete outstanding commands with TASK_ABORTED SAM status. | |
271 | * | |
272 | * This is following sam4r17, section 5.6 Aborting commands, Table 38 | |
273 | * for TMR LUN_RESET: | |
274 | * | |
275 | * a) "Yes" indicates that each command that is aborted on an I_T nexus | |
276 | * other than the one that caused the SCSI device condition is | |
277 | * completed with TASK ABORTED status, if the TAS bit is set to one in | |
278 | * the Control mode page (see SPC-4). "No" indicates that no status is | |
279 | * returned for aborted commands. | |
280 | * | |
281 | * d) If the logical unit reset is caused by a particular I_T nexus | |
282 | * (e.g., by a LOGICAL UNIT RESET task management function), then "yes" | |
283 | * (TASK_ABORTED status) applies. | |
284 | * | |
285 | * Otherwise (e.g., if triggered by a hard reset), "no" | |
286 | * (no TASK_ABORTED SAM status) applies. | |
287 | * | |
288 | * Note that this seems to be independent of TAS (Task Aborted Status) | |
289 | * in the Control Mode Page. | |
290 | */ | |
291 | for (i = 0; i < dev->queue_cnt; i++) { | |
292 | flush_work(&dev->queues[i].sq.work); | |
293 | ||
294 | spin_lock_irqsave(&dev->queues[i].lock, flags); | |
295 | list_for_each_entry_safe(cmd, next, &dev->queues[i].state_list, | |
296 | state_list) { | |
297 | /* | |
298 | * For PREEMPT_AND_ABORT usage, only process commands | |
299 | * with a matching reservation key. | |
300 | */ | |
301 | if (target_check_cdb_and_preempt(preempt_and_abort_list, | |
302 | cmd)) | |
303 | continue; | |
304 | ||
305 | /* | |
306 | * Not aborting PROUT PREEMPT_AND_ABORT CDB.. | |
307 | */ | |
308 | if (prout_cmd == cmd) | |
309 | continue; | |
310 | ||
311 | sess = cmd->se_sess; | |
312 | if (WARN_ON_ONCE(!sess)) | |
313 | continue; | |
314 | ||
315 | spin_lock(&sess->sess_cmd_lock); | |
316 | rc = __target_check_io_state(cmd, tmr_sess, tas); | |
317 | spin_unlock(&sess->sess_cmd_lock); | |
318 | if (!rc) | |
319 | continue; | |
320 | ||
321 | list_move_tail(&cmd->state_list, &drain_task_list); | |
322 | cmd->state_active = false; | |
323 | } | |
324 | spin_unlock_irqrestore(&dev->queues[i].lock, flags); | |
325 | } | |
326 | ||
327 | if (dev->transport->tmr_notify) | |
328 | dev->transport->tmr_notify(dev, preempt_and_abort_list ? | |
329 | TMR_LUN_RESET_PRO : TMR_LUN_RESET, | |
330 | &drain_task_list); | |
331 | ||
332 | while (!list_empty(&drain_task_list)) { | |
333 | cmd = list_entry(drain_task_list.next, struct se_cmd, state_list); | |
334 | list_del_init(&cmd->state_list); | |
335 | ||
336 | target_show_cmd("LUN_RESET: ", cmd); | |
337 | pr_debug("LUN_RESET: ITT[0x%08llx] - %s pr_res_key: 0x%016Lx\n", | |
338 | cmd->tag, (preempt_and_abort_list) ? "preempt" : "", | |
339 | cmd->pr_res_key); | |
340 | ||
341 | target_put_cmd_and_wait(cmd); | |
342 | } | |
343 | } | |
344 | ||
345 | int core_tmr_lun_reset( | |
346 | struct se_device *dev, | |
347 | struct se_tmr_req *tmr, | |
348 | struct list_head *preempt_and_abort_list, | |
349 | struct se_cmd *prout_cmd) | |
350 | { | |
351 | struct se_node_acl *tmr_nacl = NULL; | |
352 | struct se_portal_group *tmr_tpg = NULL; | |
353 | struct se_session *tmr_sess = NULL; | |
354 | bool tas; | |
355 | /* | |
356 | * TASK_ABORTED status bit, this is configurable via ConfigFS | |
357 | * struct se_device attributes. spc4r17 section 7.4.6 Control mode page | |
358 | * | |
359 | * A task aborted status (TAS) bit set to zero specifies that aborted | |
360 | * tasks shall be terminated by the device server without any response | |
361 | * to the application client. A TAS bit set to one specifies that tasks | |
362 | * aborted by the actions of an I_T nexus other than the I_T nexus on | |
363 | * which the command was received shall be completed with TASK ABORTED | |
364 | * status (see SAM-4). | |
365 | */ | |
366 | tas = dev->dev_attrib.emulate_tas; | |
367 | /* | |
368 | * Determine if this se_tmr is coming from a $FABRIC_MOD | |
369 | * or struct se_device passthrough.. | |
370 | */ | |
371 | if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) { | |
372 | tmr_sess = tmr->task_cmd->se_sess; | |
373 | tmr_nacl = tmr_sess->se_node_acl; | |
374 | tmr_tpg = tmr_sess->se_tpg; | |
375 | if (tmr_nacl && tmr_tpg) { | |
376 | pr_debug("LUN_RESET: TMR caller fabric: %s" | |
377 | " initiator port %s\n", | |
378 | tmr_tpg->se_tpg_tfo->fabric_name, | |
379 | tmr_nacl->initiatorname); | |
380 | } | |
381 | } | |
382 | pr_debug("LUN_RESET: %s starting for [%s], tas: %d\n", | |
383 | (preempt_and_abort_list) ? "Preempt" : "TMR", | |
384 | dev->transport->name, tas); | |
385 | ||
386 | core_tmr_drain_tmr_list(dev, tmr, preempt_and_abort_list); | |
387 | core_tmr_drain_state_list(dev, prout_cmd, tmr_sess, tas, | |
388 | preempt_and_abort_list); | |
389 | ||
390 | /* | |
391 | * Clear any legacy SPC-2 reservation when called during | |
392 | * LOGICAL UNIT RESET | |
393 | */ | |
394 | if (!preempt_and_abort_list && | |
395 | (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)) { | |
396 | spin_lock(&dev->dev_reservation_lock); | |
397 | dev->reservation_holder = NULL; | |
398 | dev->dev_reservation_flags &= ~DRF_SPC2_RESERVATIONS; | |
399 | spin_unlock(&dev->dev_reservation_lock); | |
400 | pr_debug("LUN_RESET: SCSI-2 Released reservation\n"); | |
401 | } | |
402 | ||
403 | atomic_long_inc(&dev->num_resets); | |
404 | ||
405 | pr_debug("LUN_RESET: %s for [%s] Complete\n", | |
406 | (preempt_and_abort_list) ? "Preempt" : "TMR", | |
407 | dev->transport->name); | |
408 | return 0; | |
409 | } | |
410 |