1 /*******************************************************************************
2 * Filename: target_core_tmr.c
4 * This file contains SPC-3 task management infrastructure
6 * (c) Copyright 2009-2013 Datera, Inc.
8 * Nicholas A. Bellinger <nab@kernel.org>
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
24 ******************************************************************************/
26 #include <linux/slab.h>
27 #include <linux/spinlock.h>
28 #include <linux/list.h>
29 #include <linux/export.h>
31 #include <target/target_core_base.h>
32 #include <target/target_core_backend.h>
33 #include <target/target_core_fabric.h>
35 #include "target_core_internal.h"
36 #include "target_core_alua.h"
37 #include "target_core_pr.h"
39 int core_tmr_alloc_req(
40 struct se_cmd *se_cmd,
45 struct se_tmr_req *tmr;
47 tmr = kzalloc(sizeof(struct se_tmr_req), gfp_flags);
49 pr_err("Unable to allocate struct se_tmr_req\n");
53 se_cmd->se_cmd_flags |= SCF_SCSI_TMR_CDB;
54 se_cmd->se_tmr_req = tmr;
55 tmr->task_cmd = se_cmd;
56 tmr->fabric_tmr_ptr = fabric_tmr_ptr;
57 tmr->function = function;
58 INIT_LIST_HEAD(&tmr->tmr_list);
62 EXPORT_SYMBOL(core_tmr_alloc_req);
64 void core_tmr_release_req(struct se_tmr_req *tmr)
66 struct se_device *dev = tmr->tmr_dev;
70 spin_lock_irqsave(&dev->se_tmr_lock, flags);
71 list_del_init(&tmr->tmr_list);
72 spin_unlock_irqrestore(&dev->se_tmr_lock, flags);
78 static int target_check_cdb_and_preempt(struct list_head *list,
81 struct t10_pr_registration *reg;
85 list_for_each_entry(reg, list, pr_reg_abort_list) {
86 if (reg->pr_res_key == cmd->pr_res_key)
93 static bool __target_check_io_state(struct se_cmd *se_cmd,
94 struct se_session *tmr_sess, int tas)
96 struct se_session *sess = se_cmd->se_sess;
98 assert_spin_locked(&sess->sess_cmd_lock);
99 WARN_ON_ONCE(!irqs_disabled());
101 * If command already reached CMD_T_COMPLETE state within
102 * target_complete_cmd() or CMD_T_FABRIC_STOP due to shutdown,
103 * this se_cmd has been passed to fabric driver and will
106 * Otherwise, obtain a local se_cmd->cmd_kref now for TMR
107 * ABORT_TASK + LUN_RESET for CMD_T_ABORTED processing as
108 * long as se_cmd->cmd_kref is still active unless zero.
110 spin_lock(&se_cmd->t_state_lock);
111 if (se_cmd->transport_state & (CMD_T_COMPLETE | CMD_T_FABRIC_STOP)) {
112 pr_debug("Attempted to abort io tag: %llu already complete or"
113 " fabric stop, skipping\n", se_cmd->tag);
114 spin_unlock(&se_cmd->t_state_lock);
117 if (se_cmd->transport_state & CMD_T_PRE_EXECUTE) {
118 if (se_cmd->scsi_status) {
119 pr_debug("Attempted to abort io tag: %llu early failure"
120 " status: 0x%02x\n", se_cmd->tag,
121 se_cmd->scsi_status);
122 spin_unlock(&se_cmd->t_state_lock);
126 if (sess->sess_tearing_down) {
127 pr_debug("Attempted to abort io tag: %llu already shutdown,"
128 " skipping\n", se_cmd->tag);
129 spin_unlock(&se_cmd->t_state_lock);
132 se_cmd->transport_state |= CMD_T_ABORTED;
134 if ((tmr_sess != se_cmd->se_sess) && tas)
135 se_cmd->transport_state |= CMD_T_TAS;
137 spin_unlock(&se_cmd->t_state_lock);
139 return kref_get_unless_zero(&se_cmd->cmd_kref);
142 void core_tmr_abort_task(
143 struct se_device *dev,
144 struct se_tmr_req *tmr,
145 struct se_session *se_sess)
147 struct se_cmd *se_cmd;
151 spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
152 list_for_each_entry(se_cmd, &se_sess->sess_cmd_list, se_cmd_list) {
154 if (dev != se_cmd->se_dev)
157 /* skip task management functions, including tmr->task_cmd */
158 if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
161 ref_tag = se_cmd->tag;
162 if (tmr->ref_task_tag != ref_tag)
165 printk("ABORT_TASK: Found referenced %s task_tag: %llu\n",
166 se_cmd->se_tfo->fabric_name, ref_tag);
168 if (!__target_check_io_state(se_cmd, se_sess,
169 dev->dev_attrib.emulate_tas))
172 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
175 * Ensure that this ABORT request is visible to the LU RESET
179 WARN_ON_ONCE(transport_lookup_tmr_lun(tmr->task_cmd,
180 se_cmd->orig_fe_lun) < 0);
182 target_put_cmd_and_wait(se_cmd);
184 printk("ABORT_TASK: Sending TMR_FUNCTION_COMPLETE for"
185 " ref_tag: %llu\n", ref_tag);
186 tmr->response = TMR_FUNCTION_COMPLETE;
187 atomic_long_inc(&dev->aborts_complete);
190 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
192 printk("ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: %lld\n",
194 tmr->response = TMR_TASK_DOES_NOT_EXIST;
195 atomic_long_inc(&dev->aborts_no_task);
198 static void core_tmr_drain_tmr_list(
199 struct se_device *dev,
200 struct se_tmr_req *tmr,
201 struct list_head *preempt_and_abort_list)
203 LIST_HEAD(drain_tmr_list);
204 struct se_session *sess;
205 struct se_tmr_req *tmr_p, *tmr_pp;
210 * Release all pending and outgoing TMRs aside from the received
213 spin_lock_irqsave(&dev->se_tmr_lock, flags);
215 list_del_init(&tmr->tmr_list);
216 list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) {
217 cmd = tmr_p->task_cmd;
219 pr_err("Unable to locate struct se_cmd for TMR\n");
223 * If this function was called with a valid pr_res_key
224 * parameter (eg: for PROUT PREEMPT_AND_ABORT service action
225 * skip non registration key matching TMRs.
227 if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd))
231 if (WARN_ON_ONCE(!sess))
234 spin_lock(&sess->sess_cmd_lock);
235 spin_lock(&cmd->t_state_lock);
236 if (!(cmd->transport_state & CMD_T_ACTIVE) ||
237 (cmd->transport_state & CMD_T_FABRIC_STOP)) {
238 spin_unlock(&cmd->t_state_lock);
239 spin_unlock(&sess->sess_cmd_lock);
242 if (cmd->t_state == TRANSPORT_ISTATE_PROCESSING) {
243 spin_unlock(&cmd->t_state_lock);
244 spin_unlock(&sess->sess_cmd_lock);
247 if (sess->sess_tearing_down) {
248 spin_unlock(&cmd->t_state_lock);
249 spin_unlock(&sess->sess_cmd_lock);
252 cmd->transport_state |= CMD_T_ABORTED;
253 spin_unlock(&cmd->t_state_lock);
255 rc = kref_get_unless_zero(&cmd->cmd_kref);
257 printk("LUN_RESET TMR: non-zero kref_get_unless_zero\n");
258 spin_unlock(&sess->sess_cmd_lock);
261 spin_unlock(&sess->sess_cmd_lock);
263 list_move_tail(&tmr_p->tmr_list, &drain_tmr_list);
265 spin_unlock_irqrestore(&dev->se_tmr_lock, flags);
267 list_for_each_entry_safe(tmr_p, tmr_pp, &drain_tmr_list, tmr_list) {
268 list_del_init(&tmr_p->tmr_list);
269 cmd = tmr_p->task_cmd;
271 pr_debug("LUN_RESET: %s releasing TMR %p Function: 0x%02x,"
272 " Response: 0x%02x, t_state: %d\n",
273 (preempt_and_abort_list) ? "Preempt" : "", tmr_p,
274 tmr_p->function, tmr_p->response, cmd->t_state);
276 target_put_cmd_and_wait(cmd);
281 * core_tmr_drain_state_list() - abort SCSI commands associated with a device
283 * @dev: Device for which to abort outstanding SCSI commands.
284 * @prout_cmd: Pointer to the SCSI PREEMPT AND ABORT if this function is called
285 * to realize the PREEMPT AND ABORT functionality.
286 * @tmr_sess: Session through which the LUN RESET has been received.
287 * @tas: Task Aborted Status (TAS) bit from the SCSI control mode page.
288 * A quote from SPC-4, paragraph "7.5.10 Control mode page":
289 * "A task aborted status (TAS) bit set to zero specifies that
290 * aborted commands shall be terminated by the device server
291 * without any response to the application client. A TAS bit set
292 * to one specifies that commands aborted by the actions of an I_T
293 * nexus other than the I_T nexus on which the command was
294 * received shall be completed with TASK ABORTED status."
295 * @preempt_and_abort_list: For the PREEMPT AND ABORT functionality, a list
296 * with registrations that will be preempted.
298 static void core_tmr_drain_state_list(
299 struct se_device *dev,
300 struct se_cmd *prout_cmd,
301 struct se_session *tmr_sess,
303 struct list_head *preempt_and_abort_list)
305 LIST_HEAD(drain_task_list);
306 struct se_session *sess;
307 struct se_cmd *cmd, *next;
312 * Complete outstanding commands with TASK_ABORTED SAM status.
314 * This is following sam4r17, section 5.6 Aborting commands, Table 38
317 * a) "Yes" indicates that each command that is aborted on an I_T nexus
318 * other than the one that caused the SCSI device condition is
319 * completed with TASK ABORTED status, if the TAS bit is set to one in
320 * the Control mode page (see SPC-4). "No" indicates that no status is
321 * returned for aborted commands.
323 * d) If the logical unit reset is caused by a particular I_T nexus
324 * (e.g., by a LOGICAL UNIT RESET task management function), then "yes"
325 * (TASK_ABORTED status) applies.
327 * Otherwise (e.g., if triggered by a hard reset), "no"
328 * (no TASK_ABORTED SAM status) applies.
330 * Note that this seems to be independent of TAS (Task Aborted Status)
331 * in the Control Mode Page.
333 spin_lock_irqsave(&dev->execute_task_lock, flags);
334 list_for_each_entry_safe(cmd, next, &dev->state_list, state_list) {
336 * For PREEMPT_AND_ABORT usage, only process commands
337 * with a matching reservation key.
339 if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd))
343 * Not aborting PROUT PREEMPT_AND_ABORT CDB..
345 if (prout_cmd == cmd)
349 if (WARN_ON_ONCE(!sess))
352 spin_lock(&sess->sess_cmd_lock);
353 rc = __target_check_io_state(cmd, tmr_sess, tas);
354 spin_unlock(&sess->sess_cmd_lock);
358 list_move_tail(&cmd->state_list, &drain_task_list);
359 cmd->state_active = false;
361 spin_unlock_irqrestore(&dev->execute_task_lock, flags);
363 while (!list_empty(&drain_task_list)) {
364 cmd = list_entry(drain_task_list.next, struct se_cmd, state_list);
365 list_del_init(&cmd->state_list);
367 target_show_cmd("LUN_RESET: ", cmd);
368 pr_debug("LUN_RESET: ITT[0x%08llx] - %s pr_res_key: 0x%016Lx\n",
369 cmd->tag, (preempt_and_abort_list) ? "preempt" : "",
372 target_put_cmd_and_wait(cmd);
376 int core_tmr_lun_reset(
377 struct se_device *dev,
378 struct se_tmr_req *tmr,
379 struct list_head *preempt_and_abort_list,
380 struct se_cmd *prout_cmd)
382 struct se_node_acl *tmr_nacl = NULL;
383 struct se_portal_group *tmr_tpg = NULL;
384 struct se_session *tmr_sess = NULL;
387 * TASK_ABORTED status bit, this is configurable via ConfigFS
388 * struct se_device attributes. spc4r17 section 7.4.6 Control mode page
390 * A task aborted status (TAS) bit set to zero specifies that aborted
391 * tasks shall be terminated by the device server without any response
392 * to the application client. A TAS bit set to one specifies that tasks
393 * aborted by the actions of an I_T nexus other than the I_T nexus on
394 * which the command was received shall be completed with TASK ABORTED
395 * status (see SAM-4).
397 tas = dev->dev_attrib.emulate_tas;
399 * Determine if this se_tmr is coming from a $FABRIC_MOD
400 * or struct se_device passthrough..
402 if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) {
403 tmr_sess = tmr->task_cmd->se_sess;
404 tmr_nacl = tmr_sess->se_node_acl;
405 tmr_tpg = tmr_sess->se_tpg;
406 if (tmr_nacl && tmr_tpg) {
407 pr_debug("LUN_RESET: TMR caller fabric: %s"
408 " initiator port %s\n",
409 tmr_tpg->se_tpg_tfo->fabric_name,
410 tmr_nacl->initiatorname);
413 pr_debug("LUN_RESET: %s starting for [%s], tas: %d\n",
414 (preempt_and_abort_list) ? "Preempt" : "TMR",
415 dev->transport->name, tas);
417 core_tmr_drain_tmr_list(dev, tmr, preempt_and_abort_list);
418 core_tmr_drain_state_list(dev, prout_cmd, tmr_sess, tas,
419 preempt_and_abort_list);
422 * Clear any legacy SPC-2 reservation when called during
425 if (!preempt_and_abort_list &&
426 (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)) {
427 spin_lock(&dev->dev_reservation_lock);
428 dev->dev_reserved_node_acl = NULL;
429 dev->dev_reservation_flags &= ~DRF_SPC2_RESERVATIONS;
430 spin_unlock(&dev->dev_reservation_lock);
431 pr_debug("LUN_RESET: SCSI-2 Released reservation\n");
434 atomic_long_inc(&dev->num_resets);
436 pr_debug("LUN_RESET: %s for [%s] Complete\n",
437 (preempt_and_abort_list) ? "Preempt" : "TMR",
438 dev->transport->name);