releases/3.1.1/target-re-org-of-core_tmr_lun_reset.patch

   1 From d050ffb922c782f092234611b9019e95024481ab Mon Sep 17 00:00:00 2001
   2 From: Nicholas Bellinger <nab@linux-iscsi.org>
   3 Date: Wed, 28 Sep 2011 21:37:29 -0700
   4 Subject: target: Re-org of core_tmr_lun_reset
   5
   6 From: Nicholas Bellinger <nab@linux-iscsi.org>
   7
   8 commit d050ffb922c782f092234611b9019e95024481ab upstream.
   9
  10 This patch is a re-orginzation of core_tmr_lun_reset() logic to properly
  11 scan the active tmr_list, dev->state_task_list and qobj->qobj_list w/ the
  12 relivent locks held, and performing a list_move_tail onto seperate local
  13 scope lists before performing the full drain.
  14
  15 This involves breaking out the code into three seperate list specific
  16 functions: core_tmr_drain_tmr_list(), core_tmr_drain_task_list() and
  17 core_tmr_drain_cmd_list().
  18
  19 (nab: Include target: Remove non-active tasks from execute list during
  20       LUN_RESET patch to address original breakage)
  21
  22 Reported-by: Roland Dreier <roland@purestorage.com>
  23 Cc: Roland Dreier <roland@purestorage.com>
  24 Cc: Christoph Hellwig <hch@lst.de>
  25 Signed-off-by: Nicholas Bellinger <nab@risingtidesystems.com>
  26 Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
  27
  28 ---
  29  drivers/target/target_core_tmr.c |  197 ++++++++++++++++++++++++---------------
  30  1 file changed, 125 insertions(+), 72 deletions(-)
  31
  32 --- a/drivers/target/target_core_tmr.c
  33 +++ b/drivers/target/target_core_tmr.c
  34 @@ -67,15 +67,16 @@ void core_tmr_release_req(
  35         struct se_tmr_req *tmr)
  36  {
  37         struct se_device *dev = tmr->tmr_dev;
  38 +       unsigned long flags;
  39
  40         if (!dev) {
  41                 kmem_cache_free(se_tmr_req_cache, tmr);
  42                 return;
  43         }
  44
  45 -       spin_lock_irq(&dev->se_tmr_lock);
  46 +       spin_lock_irqsave(&dev->se_tmr_lock, flags);
  47         list_del(&tmr->tmr_list);
  48 -       spin_unlock_irq(&dev->se_tmr_lock);
  49 +       spin_unlock_irqrestore(&dev->se_tmr_lock, flags);
  50
  51         kmem_cache_free(se_tmr_req_cache, tmr);
  52  }
  53 @@ -100,54 +101,20 @@ static void core_tmr_handle_tas_abort(
  54         transport_cmd_finish_abort(cmd, 0);
  55  }
  56
  57 -int core_tmr_lun_reset(
  58 +static void core_tmr_drain_tmr_list(
  59         struct se_device *dev,
  60         struct se_tmr_req *tmr,
  61 -       struct list_head *preempt_and_abort_list,
  62 -       struct se_cmd *prout_cmd)
  63 +       struct list_head *preempt_and_abort_list)
  64  {
  65 -       struct se_cmd *cmd, *tcmd;
  66 -       struct se_node_acl *tmr_nacl = NULL;
  67 -       struct se_portal_group *tmr_tpg = NULL;
  68 -       struct se_queue_obj *qobj = &dev->dev_queue_obj;
  69 +       LIST_HEAD(drain_tmr_list);
  70         struct se_tmr_req *tmr_p, *tmr_pp;
  71 -       struct se_task *task, *task_tmp;
  72 +       struct se_cmd *cmd;
  73         unsigned long flags;
  74 -       int fe_count, tas;
  75 -       /*
  76 -        * TASK_ABORTED status bit, this is configurable via ConfigFS
  77 -        * struct se_device attributes.  spc4r17 section 7.4.6 Control mode page
  78 -        *
  79 -        * A task aborted status (TAS) bit set to zero specifies that aborted
  80 -        * tasks shall be terminated by the device server without any response
  81 -        * to the application client. A TAS bit set to one specifies that tasks
  82 -        * aborted by the actions of an I_T nexus other than the I_T nexus on
  83 -        * which the command was received shall be completed with TASK ABORTED
  84 -        * status (see SAM-4).
  85 -        */
  86 -       tas = dev->se_sub_dev->se_dev_attrib.emulate_tas;
  87 -       /*
  88 -        * Determine if this se_tmr is coming from a $FABRIC_MOD
  89 -        * or struct se_device passthrough..
  90 -        */
  91 -       if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) {
  92 -               tmr_nacl = tmr->task_cmd->se_sess->se_node_acl;
  93 -               tmr_tpg = tmr->task_cmd->se_sess->se_tpg;
  94 -               if (tmr_nacl && tmr_tpg) {
  95 -                       pr_debug("LUN_RESET: TMR caller fabric: %s"
  96 -                               " initiator port %s\n",
  97 -                               tmr_tpg->se_tpg_tfo->get_fabric_name(),
  98 -                               tmr_nacl->initiatorname);
  99 -               }
 100 -       }
 101 -       pr_debug("LUN_RESET: %s starting for [%s], tas: %d\n",
 102 -               (preempt_and_abort_list) ? "Preempt" : "TMR",
 103 -               dev->transport->name, tas);
 104         /*
 105          * Release all pending and outgoing TMRs aside from the received
 106          * LUN_RESET tmr..
 107          */
 108 -       spin_lock_irq(&dev->se_tmr_lock);
 109 +       spin_lock_irqsave(&dev->se_tmr_lock, flags);
 110         list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) {
 111                 /*
 112                  * Allow the received TMR to return with FUNCTION_COMPLETE.
 113 @@ -169,29 +136,48 @@ int core_tmr_lun_reset(
 114                     (core_scsi3_check_cdb_abort_and_preempt(
 115                                         preempt_and_abort_list, cmd) != 0))
 116                         continue;
 117 -               spin_unlock_irq(&dev->se_tmr_lock);
 118
 119 -               spin_lock_irqsave(&cmd->t_state_lock, flags);
 120 +               spin_lock(&cmd->t_state_lock);
 121                 if (!atomic_read(&cmd->t_transport_active)) {
 122 -                       spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 123 -                       spin_lock_irq(&dev->se_tmr_lock);
 124 +                       spin_unlock(&cmd->t_state_lock);
 125                         continue;
 126                 }
 127                 if (cmd->t_state == TRANSPORT_ISTATE_PROCESSING) {
 128 -                       spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 129 -                       spin_lock_irq(&dev->se_tmr_lock);
 130 +                       spin_unlock(&cmd->t_state_lock);
 131                         continue;
 132                 }
 133 +               spin_unlock(&cmd->t_state_lock);
 134 +
 135 +               list_move_tail(&tmr->tmr_list, &drain_tmr_list);
 136 +       }
 137 +       spin_unlock_irqrestore(&dev->se_tmr_lock, flags);
 138 +
 139 +       while (!list_empty(&drain_tmr_list)) {
 140 +               tmr = list_entry(drain_tmr_list.next, struct se_tmr_req, tmr_list);
 141 +               list_del(&tmr->tmr_list);
 142 +               cmd = tmr_p->task_cmd;
 143 +
 144                 pr_debug("LUN_RESET: %s releasing TMR %p Function: 0x%02x,"
 145                         " Response: 0x%02x, t_state: %d\n",
 146 -                       (preempt_and_abort_list) ? "Preempt" : "", tmr_p,
 147 -                       tmr_p->function, tmr_p->response, cmd->t_state);
 148 -               spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 149 +                       (preempt_and_abort_list) ? "Preempt" : "", tmr,
 150 +                       tmr->function, tmr->response, cmd->t_state);
 151
 152                 transport_cmd_finish_abort_tmr(cmd);
 153 -               spin_lock_irq(&dev->se_tmr_lock);
 154         }
 155 -       spin_unlock_irq(&dev->se_tmr_lock);
 156 +}
 157 +
 158 +static void core_tmr_drain_task_list(
 159 +       struct se_device *dev,
 160 +       struct se_cmd *prout_cmd,
 161 +       struct se_node_acl *tmr_nacl,
 162 +       int tas,
 163 +       struct list_head *preempt_and_abort_list)
 164 +{
 165 +       LIST_HEAD(drain_task_list);
 166 +       struct se_cmd *cmd;
 167 +       struct se_task *task, *task_tmp;
 168 +       unsigned long flags;
 169 +       int fe_count;
 170         /*
 171          * Complete outstanding struct se_task CDBs with TASK_ABORTED SAM status.
 172          * This is following sam4r17, section 5.6 Aborting commands, Table 38
 173 @@ -236,9 +222,23 @@ int core_tmr_lun_reset(
 174                 if (prout_cmd == cmd)
 175                         continue;
 176
 177 -               list_del(&task->t_state_list);
 178 +               list_move_tail(&task->t_state_list, &drain_task_list);
 179                 atomic_set(&task->task_state_active, 0);
 180 -               spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 181 +               /*
 182 +                * Remove from task execute list before processing drain_task_list
 183 +                */
 184 +               if (atomic_read(&task->task_execute_queue) != 0) {
 185 +                       list_del(&task->t_execute_list);
 186 +                       atomic_set(&task->task_execute_queue, 0);
 187 +                       atomic_dec(&dev->execute_tasks);
 188 +               }
 189 +       }
 190 +       spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 191 +
 192 +       while (!list_empty(&drain_task_list)) {
 193 +               task = list_entry(drain_task_list.next, struct se_task, t_state_list);
 194 +               list_del(&task->t_state_list);
 195 +               cmd = task->task_se_cmd;
 196
 197                 spin_lock_irqsave(&cmd->t_state_lock, flags);
 198                 pr_debug("LUN_RESET: %s cmd: %p task: %p"
 199 @@ -275,20 +275,14 @@ int core_tmr_lun_reset(
 200
 201                         atomic_set(&task->task_active, 0);
 202                         atomic_set(&task->task_stop, 0);
 203 -               } else {
 204 -                       if (atomic_read(&task->task_execute_queue) != 0)
 205 -                               transport_remove_task_from_execute_queue(task, dev);
 206                 }
 207                 __transport_stop_task_timer(task, &flags);
 208
 209                 if (!atomic_dec_and_test(&cmd->t_task_cdbs_ex_left)) {
 210 -                       spin_unlock_irqrestore(
 211 -                                       &cmd->t_state_lock, flags);
 212 +                       spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 213                         pr_debug("LUN_RESET: Skipping task: %p, dev: %p for"
 214                                 " t_task_cdbs_ex_left: %d\n", task, dev,
 215                                 atomic_read(&cmd->t_task_cdbs_ex_left));
 216 -
 217 -                       spin_lock_irqsave(&dev->execute_task_lock, flags);
 218                         continue;
 219                 }
 220                 fe_count = atomic_read(&cmd->t_fe_count);
 221 @@ -298,22 +292,31 @@ int core_tmr_lun_reset(
 222                                 " task: %p, t_fe_count: %d dev: %p\n", task,
 223                                 fe_count, dev);
 224                         atomic_set(&cmd->t_transport_aborted, 1);
 225 -                       spin_unlock_irqrestore(&cmd->t_state_lock,
 226 -                                               flags);
 227 -                       core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
 228 +                       spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 229
 230 -                       spin_lock_irqsave(&dev->execute_task_lock, flags);
 231 +                       core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
 232                         continue;
 233                 }
 234                 pr_debug("LUN_RESET: Got t_transport_active = 0 for task: %p,"
 235                         " t_fe_count: %d dev: %p\n", task, fe_count, dev);
 236                 atomic_set(&cmd->t_transport_aborted, 1);
 237                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 238 -               core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
 239
 240 -               spin_lock_irqsave(&dev->execute_task_lock, flags);
 241 +               core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
 242         }
 243 -       spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 244 +}
 245 +
 246 +static void core_tmr_drain_cmd_list(
 247 +       struct se_device *dev,
 248 +       struct se_cmd *prout_cmd,
 249 +       struct se_node_acl *tmr_nacl,
 250 +       int tas,
 251 +       struct list_head *preempt_and_abort_list)
 252 +{
 253 +       LIST_HEAD(drain_cmd_list);
 254 +       struct se_queue_obj *qobj = &dev->dev_queue_obj;
 255 +       struct se_cmd *cmd, *tcmd;
 256 +       unsigned long flags;
 257         /*
 258          * Release all commands remaining in the struct se_device cmd queue.
 259          *
 260 @@ -348,10 +351,15 @@ int core_tmr_lun_reset(
 261                 }
 262                 spin_unlock(&cmd->t_state_lock);
 263
 264 -               atomic_dec(&cmd->t_transport_queue_active);
 265 +               atomic_set(&cmd->t_transport_queue_active, 0);
 266                 atomic_dec(&qobj->queue_cnt);
 267 +               list_move_tail(&cmd->se_queue_node, &drain_cmd_list);
 268 +       }
 269 +       spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
 270 +
 271 +       while (!list_empty(&drain_cmd_list)) {
 272 +               cmd = list_entry(drain_cmd_list.next, struct se_cmd, se_queue_node);
 273                 list_del_init(&cmd->se_queue_node);
 274 -               spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
 275
 276                 pr_debug("LUN_RESET: %s from Device Queue: cmd: %p t_state:"
 277                         " %d t_fe_count: %d\n", (preempt_and_abort_list) ?
 278 @@ -364,9 +372,53 @@ int core_tmr_lun_reset(
 279
 280                 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas,
 281                                 atomic_read(&cmd->t_fe_count));
 282 -               spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
 283         }
 284 -       spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
 285 +}
 286 +
 287 +int core_tmr_lun_reset(
 288 +        struct se_device *dev,
 289 +        struct se_tmr_req *tmr,
 290 +        struct list_head *preempt_and_abort_list,
 291 +        struct se_cmd *prout_cmd)
 292 +{
 293 +       struct se_node_acl *tmr_nacl = NULL;
 294 +       struct se_portal_group *tmr_tpg = NULL;
 295 +       int tas;
 296 +        /*
 297 +        * TASK_ABORTED status bit, this is configurable via ConfigFS
 298 +        * struct se_device attributes.  spc4r17 section 7.4.6 Control mode page
 299 +        *
 300 +        * A task aborted status (TAS) bit set to zero specifies that aborted
 301 +        * tasks shall be terminated by the device server without any response
 302 +        * to the application client. A TAS bit set to one specifies that tasks
 303 +        * aborted by the actions of an I_T nexus other than the I_T nexus on
 304 +        * which the command was received shall be completed with TASK ABORTED
 305 +        * status (see SAM-4).
 306 +        */
 307 +       tas = dev->se_sub_dev->se_dev_attrib.emulate_tas;
 308 +       /*
 309 +        * Determine if this se_tmr is coming from a $FABRIC_MOD
 310 +        * or struct se_device passthrough..
 311 +        */
 312 +       if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) {
 313 +               tmr_nacl = tmr->task_cmd->se_sess->se_node_acl;
 314 +               tmr_tpg = tmr->task_cmd->se_sess->se_tpg;
 315 +               if (tmr_nacl && tmr_tpg) {
 316 +                       pr_debug("LUN_RESET: TMR caller fabric: %s"
 317 +                               " initiator port %s\n",
 318 +                               tmr_tpg->se_tpg_tfo->get_fabric_name(),
 319 +                               tmr_nacl->initiatorname);
 320 +               }
 321 +       }
 322 +       pr_debug("LUN_RESET: %s starting for [%s], tas: %d\n",
 323 +               (preempt_and_abort_list) ? "Preempt" : "TMR",
 324 +               dev->transport->name, tas);
 325 +
 326 +       core_tmr_drain_tmr_list(dev, tmr, preempt_and_abort_list);
 327 +       core_tmr_drain_task_list(dev, prout_cmd, tmr_nacl, tas,
 328 +                               preempt_and_abort_list);
 329 +       core_tmr_drain_cmd_list(dev, prout_cmd, tmr_nacl, tas,
 330 +                               preempt_and_abort_list);
 331         /*
 332          * Clear any legacy SPC-2 reservation when called during
 333          * LOGICAL UNIT RESET
 334 @@ -389,3 +441,4 @@ int core_tmr_lun_reset(
 335                         dev->transport->name);
 336         return 0;
 337  }
 338 +