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(size: sizeof(struct se_tmr_req), flags: 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(list: &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(objp: 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 | lockdep_assert_held(&sess->sess_cmd_lock); |
77 | |
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(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(lock: &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(lock: &se_cmd->t_state_lock); |
101 | |
102 | return kref_get_unless_zero(kref: &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(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(lock: &se_sess->sess_cmd_lock); |
141 | rc = __target_check_io_state(se_cmd, tmr_sess: se_sess, tas: 0); |
142 | spin_unlock(lock: &se_sess->sess_cmd_lock); |
143 | if (!rc) |
144 | continue; |
145 | |
146 | list_move_tail(list: &se_cmd->state_list, head: &aborted_list); |
147 | se_cmd->state_active = false; |
148 | spin_unlock_irqrestore(lock: &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(entry: &se_cmd->state_list); |
155 | target_put_cmd_and_wait(cmd: 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(v: &dev->aborts_complete); |
161 | return; |
162 | } |
163 | spin_unlock_irqrestore(lock: &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(v: &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 | list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) { |
192 | if (tmr_p == tmr) |
193 | continue; |
194 | |
195 | cmd = tmr_p->task_cmd; |
196 | if (!cmd) { |
197 | pr_err("Unable to locate struct se_cmd for TMR\n" ); |
198 | continue; |
199 | } |
200 | |
201 | /* |
202 | * We only execute one LUN_RESET at a time so we can't wait |
203 | * on them below. |
204 | */ |
205 | if (tmr_p->function == TMR_LUN_RESET) |
206 | continue; |
207 | |
208 | /* |
209 | * If this function was called with a valid pr_res_key |
210 | * parameter (eg: for PROUT PREEMPT_AND_ABORT service action |
211 | * skip non registration key matching TMRs. |
212 | */ |
213 | if (target_check_cdb_and_preempt(list: preempt_and_abort_list, cmd)) |
214 | continue; |
215 | |
216 | sess = cmd->se_sess; |
217 | if (WARN_ON_ONCE(!sess)) |
218 | continue; |
219 | |
220 | spin_lock(lock: &sess->sess_cmd_lock); |
221 | rc = __target_check_io_state(se_cmd: cmd, tmr_sess: sess, tas: 0); |
222 | spin_unlock(lock: &sess->sess_cmd_lock); |
223 | |
224 | if (!rc) { |
225 | printk("LUN_RESET TMR: non-zero kref_get_unless_zero\n" ); |
226 | continue; |
227 | } |
228 | |
229 | list_move_tail(list: &tmr_p->tmr_list, head: &drain_tmr_list); |
230 | tmr_p->tmr_dev = NULL; |
231 | } |
232 | spin_unlock_irqrestore(lock: &dev->se_tmr_lock, flags); |
233 | |
234 | list_for_each_entry_safe(tmr_p, tmr_pp, &drain_tmr_list, tmr_list) { |
235 | list_del_init(entry: &tmr_p->tmr_list); |
236 | cmd = tmr_p->task_cmd; |
237 | |
238 | pr_debug("LUN_RESET: %s releasing TMR %p Function: 0x%02x," |
239 | " Response: 0x%02x, t_state: %d\n" , |
240 | (preempt_and_abort_list) ? "Preempt" : "" , tmr_p, |
241 | tmr_p->function, tmr_p->response, cmd->t_state); |
242 | |
243 | target_put_cmd_and_wait(cmd); |
244 | } |
245 | } |
246 | |
247 | /** |
248 | * core_tmr_drain_state_list() - abort SCSI commands associated with a device |
249 | * |
250 | * @dev: Device for which to abort outstanding SCSI commands. |
251 | * @prout_cmd: Pointer to the SCSI PREEMPT AND ABORT if this function is called |
252 | * to realize the PREEMPT AND ABORT functionality. |
253 | * @tmr_sess: Session through which the LUN RESET has been received. |
254 | * @tas: Task Aborted Status (TAS) bit from the SCSI control mode page. |
255 | * A quote from SPC-4, paragraph "7.5.10 Control mode page": |
256 | * "A task aborted status (TAS) bit set to zero specifies that |
257 | * aborted commands shall be terminated by the device server |
258 | * without any response to the application client. A TAS bit set |
259 | * to one specifies that commands aborted by the actions of an I_T |
260 | * nexus other than the I_T nexus on which the command was |
261 | * received shall be completed with TASK ABORTED status." |
262 | * @preempt_and_abort_list: For the PREEMPT AND ABORT functionality, a list |
263 | * with registrations that will be preempted. |
264 | */ |
265 | static void core_tmr_drain_state_list( |
266 | struct se_device *dev, |
267 | struct se_cmd *prout_cmd, |
268 | struct se_session *tmr_sess, |
269 | bool tas, |
270 | struct list_head *preempt_and_abort_list) |
271 | { |
272 | LIST_HEAD(drain_task_list); |
273 | struct se_session *sess; |
274 | struct se_cmd *cmd, *next; |
275 | unsigned long flags; |
276 | int rc, i; |
277 | |
278 | /* |
279 | * Complete outstanding commands with TASK_ABORTED SAM status. |
280 | * |
281 | * This is following sam4r17, section 5.6 Aborting commands, Table 38 |
282 | * for TMR LUN_RESET: |
283 | * |
284 | * a) "Yes" indicates that each command that is aborted on an I_T nexus |
285 | * other than the one that caused the SCSI device condition is |
286 | * completed with TASK ABORTED status, if the TAS bit is set to one in |
287 | * the Control mode page (see SPC-4). "No" indicates that no status is |
288 | * returned for aborted commands. |
289 | * |
290 | * d) If the logical unit reset is caused by a particular I_T nexus |
291 | * (e.g., by a LOGICAL UNIT RESET task management function), then "yes" |
292 | * (TASK_ABORTED status) applies. |
293 | * |
294 | * Otherwise (e.g., if triggered by a hard reset), "no" |
295 | * (no TASK_ABORTED SAM status) applies. |
296 | * |
297 | * Note that this seems to be independent of TAS (Task Aborted Status) |
298 | * in the Control Mode Page. |
299 | */ |
300 | for (i = 0; i < dev->queue_cnt; i++) { |
301 | flush_work(work: &dev->queues[i].sq.work); |
302 | |
303 | spin_lock_irqsave(&dev->queues[i].lock, flags); |
304 | list_for_each_entry_safe(cmd, next, &dev->queues[i].state_list, |
305 | state_list) { |
306 | /* |
307 | * For PREEMPT_AND_ABORT usage, only process commands |
308 | * with a matching reservation key. |
309 | */ |
310 | if (target_check_cdb_and_preempt(list: preempt_and_abort_list, |
311 | cmd)) |
312 | continue; |
313 | |
314 | /* |
315 | * Not aborting PROUT PREEMPT_AND_ABORT CDB.. |
316 | */ |
317 | if (prout_cmd == cmd) |
318 | continue; |
319 | |
320 | sess = cmd->se_sess; |
321 | if (WARN_ON_ONCE(!sess)) |
322 | continue; |
323 | |
324 | spin_lock(lock: &sess->sess_cmd_lock); |
325 | rc = __target_check_io_state(se_cmd: cmd, tmr_sess, tas); |
326 | spin_unlock(lock: &sess->sess_cmd_lock); |
327 | if (!rc) |
328 | continue; |
329 | |
330 | list_move_tail(list: &cmd->state_list, head: &drain_task_list); |
331 | cmd->state_active = false; |
332 | } |
333 | spin_unlock_irqrestore(lock: &dev->queues[i].lock, flags); |
334 | } |
335 | |
336 | if (dev->transport->tmr_notify) |
337 | dev->transport->tmr_notify(dev, preempt_and_abort_list ? |
338 | TMR_LUN_RESET_PRO : TMR_LUN_RESET, |
339 | &drain_task_list); |
340 | |
341 | while (!list_empty(head: &drain_task_list)) { |
342 | cmd = list_entry(drain_task_list.next, struct se_cmd, state_list); |
343 | list_del_init(entry: &cmd->state_list); |
344 | |
345 | target_show_cmd(pfx: "LUN_RESET: " , cmd); |
346 | pr_debug("LUN_RESET: ITT[0x%08llx] - %s pr_res_key: 0x%016Lx\n" , |
347 | cmd->tag, (preempt_and_abort_list) ? "preempt" : "" , |
348 | cmd->pr_res_key); |
349 | |
350 | target_put_cmd_and_wait(cmd); |
351 | } |
352 | } |
353 | |
354 | int core_tmr_lun_reset( |
355 | struct se_device *dev, |
356 | struct se_tmr_req *tmr, |
357 | struct list_head *preempt_and_abort_list, |
358 | struct se_cmd *prout_cmd) |
359 | { |
360 | struct se_node_acl *tmr_nacl = NULL; |
361 | struct se_portal_group *tmr_tpg = NULL; |
362 | struct se_session *tmr_sess = NULL; |
363 | bool tas; |
364 | /* |
365 | * TASK_ABORTED status bit, this is configurable via ConfigFS |
366 | * struct se_device attributes. spc4r17 section 7.4.6 Control mode page |
367 | * |
368 | * A task aborted status (TAS) bit set to zero specifies that aborted |
369 | * tasks shall be terminated by the device server without any response |
370 | * to the application client. A TAS bit set to one specifies that tasks |
371 | * aborted by the actions of an I_T nexus other than the I_T nexus on |
372 | * which the command was received shall be completed with TASK ABORTED |
373 | * status (see SAM-4). |
374 | */ |
375 | tas = dev->dev_attrib.emulate_tas; |
376 | /* |
377 | * Determine if this se_tmr is coming from a $FABRIC_MOD |
378 | * or struct se_device passthrough.. |
379 | */ |
380 | if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) { |
381 | tmr_sess = tmr->task_cmd->se_sess; |
382 | tmr_nacl = tmr_sess->se_node_acl; |
383 | tmr_tpg = tmr_sess->se_tpg; |
384 | if (tmr_nacl && tmr_tpg) { |
385 | pr_debug("LUN_RESET: TMR caller fabric: %s" |
386 | " initiator port %s\n" , |
387 | tmr_tpg->se_tpg_tfo->fabric_name, |
388 | tmr_nacl->initiatorname); |
389 | } |
390 | } |
391 | |
392 | |
393 | /* |
394 | * We only allow one reset or preempt and abort to execute at a time |
395 | * to prevent one call from claiming all the cmds causing a second |
396 | * call from returning while cmds it should have waited on are still |
397 | * running. |
398 | */ |
399 | mutex_lock(&dev->lun_reset_mutex); |
400 | |
401 | pr_debug("LUN_RESET: %s starting for [%s], tas: %d\n" , |
402 | (preempt_and_abort_list) ? "Preempt" : "TMR" , |
403 | dev->transport->name, tas); |
404 | core_tmr_drain_tmr_list(dev, tmr, preempt_and_abort_list); |
405 | core_tmr_drain_state_list(dev, prout_cmd, tmr_sess, tas, |
406 | preempt_and_abort_list); |
407 | |
408 | mutex_unlock(lock: &dev->lun_reset_mutex); |
409 | |
410 | /* |
411 | * Clear any legacy SPC-2 reservation when called during |
412 | * LOGICAL UNIT RESET |
413 | */ |
414 | if (!preempt_and_abort_list && |
415 | (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)) { |
416 | spin_lock(lock: &dev->dev_reservation_lock); |
417 | dev->reservation_holder = NULL; |
418 | dev->dev_reservation_flags &= ~DRF_SPC2_RESERVATIONS; |
419 | spin_unlock(lock: &dev->dev_reservation_lock); |
420 | pr_debug("LUN_RESET: SCSI-2 Released reservation\n" ); |
421 | } |
422 | |
423 | atomic_long_inc(v: &dev->num_resets); |
424 | |
425 | pr_debug("LUN_RESET: %s for [%s] Complete\n" , |
426 | (preempt_and_abort_list) ? "Preempt" : "TMR" , |
427 | dev->transport->name); |
428 | return 0; |
429 | } |
430 | |
431 | |