1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * SCSI RDMA (SRP) transport class 4 * 5 * Copyright (C) 2007 FUJITA Tomonori <tomof@acm.org> 6 */ 7 #include <linux/init.h> 8 #include <linux/module.h> 9 #include <linux/jiffies.h> 10 #include <linux/err.h> 11 #include <linux/slab.h> 12 #include <linux/string.h> 13 14 #include <scsi/scsi.h> 15 #include <scsi/scsi_cmnd.h> 16 #include <scsi/scsi_device.h> 17 #include <scsi/scsi_host.h> 18 #include <scsi/scsi_transport.h> 19 #include <scsi/scsi_transport_srp.h> 20 #include "scsi_priv.h" 21 22 struct srp_host_attrs { 23 atomic_t next_port_id; 24 }; 25 #define to_srp_host_attrs(host) ((struct srp_host_attrs *)(host)->shost_data) 26 27 #define SRP_HOST_ATTRS 0 28 #define SRP_RPORT_ATTRS 8 29 30 struct srp_internal { 31 struct scsi_transport_template t; 32 struct srp_function_template *f; 33 34 struct device_attribute *host_attrs[SRP_HOST_ATTRS + 1]; 35 36 struct device_attribute *rport_attrs[SRP_RPORT_ATTRS + 1]; 37 struct transport_container rport_attr_cont; 38 }; 39 40 static int scsi_is_srp_rport(const struct device *dev); 41 42 #define to_srp_internal(tmpl) container_of(tmpl, struct srp_internal, t) 43 44 #define dev_to_rport(d) container_of(d, struct srp_rport, dev) 45 #define transport_class_to_srp_rport(dev) dev_to_rport((dev)->parent) 46 static inline struct Scsi_Host *rport_to_shost(struct srp_rport *r) 47 { 48 return dev_to_shost(r->dev.parent); 49 } 50 51 static int find_child_rport(struct device *dev, void *data) 52 { 53 struct device **child = data; 54 55 if (scsi_is_srp_rport(dev)) { 56 WARN_ON_ONCE(*child); 57 *child = dev; 58 } 59 return 0; 60 } 61 62 static inline struct srp_rport *shost_to_rport(struct Scsi_Host *shost) 63 { 64 struct device *child = NULL; 65 66 WARN_ON_ONCE(device_for_each_child(&shost->shost_gendev, &child, 67 find_child_rport) < 0); 68 return child ? dev_to_rport(child) : NULL; 69 } 70 71 /** 72 * srp_tmo_valid() - check timeout combination validity 73 * @reconnect_delay: Reconnect delay in seconds. 74 * @fast_io_fail_tmo: Fast I/O fail timeout in seconds. 75 * @dev_loss_tmo: Device loss timeout in seconds. 76 * 77 * The combination of the timeout parameters must be such that SCSI commands 78 * are finished in a reasonable time. Hence do not allow the fast I/O fail 79 * timeout to exceed SCSI_DEVICE_BLOCK_MAX_TIMEOUT nor allow dev_loss_tmo to 80 * exceed that limit if failing I/O fast has been disabled. Furthermore, these 81 * parameters must be such that multipath can detect failed paths timely. 82 * Hence do not allow all three parameters to be disabled simultaneously. 83 */ 84 int srp_tmo_valid(int reconnect_delay, int fast_io_fail_tmo, long dev_loss_tmo) 85 { 86 if (reconnect_delay < 0 && fast_io_fail_tmo < 0 && dev_loss_tmo < 0) 87 return -EINVAL; 88 if (reconnect_delay == 0) 89 return -EINVAL; 90 if (fast_io_fail_tmo > SCSI_DEVICE_BLOCK_MAX_TIMEOUT) 91 return -EINVAL; 92 if (fast_io_fail_tmo < 0 && 93 dev_loss_tmo > SCSI_DEVICE_BLOCK_MAX_TIMEOUT) 94 return -EINVAL; 95 if (dev_loss_tmo >= LONG_MAX / HZ) 96 return -EINVAL; 97 if (fast_io_fail_tmo >= 0 && dev_loss_tmo >= 0 && 98 fast_io_fail_tmo >= dev_loss_tmo) 99 return -EINVAL; 100 return 0; 101 } 102 EXPORT_SYMBOL_GPL(srp_tmo_valid); 103 104 static int srp_host_setup(struct transport_container *tc, struct device *dev, 105 struct device *cdev) 106 { 107 struct Scsi_Host *shost = dev_to_shost(dev); 108 struct srp_host_attrs *srp_host = to_srp_host_attrs(shost); 109 110 atomic_set(&srp_host->next_port_id, 0); 111 return 0; 112 } 113 114 static DECLARE_TRANSPORT_CLASS(srp_host_class, "srp_host", srp_host_setup, 115 NULL, NULL); 116 117 static DECLARE_TRANSPORT_CLASS(srp_rport_class, "srp_remote_ports", 118 NULL, NULL, NULL); 119 120 static ssize_t 121 show_srp_rport_id(struct device *dev, struct device_attribute *attr, 122 char *buf) 123 { 124 struct srp_rport *rport = transport_class_to_srp_rport(dev); 125 return sprintf(buf, "%16phC\n", rport->port_id); 126 } 127 128 static DEVICE_ATTR(port_id, S_IRUGO, show_srp_rport_id, NULL); 129 130 static const struct { 131 u32 value; 132 char *name; 133 } srp_rport_role_names[] = { 134 {SRP_RPORT_ROLE_INITIATOR, "SRP Initiator"}, 135 {SRP_RPORT_ROLE_TARGET, "SRP Target"}, 136 }; 137 138 static ssize_t 139 show_srp_rport_roles(struct device *dev, struct device_attribute *attr, 140 char *buf) 141 { 142 struct srp_rport *rport = transport_class_to_srp_rport(dev); 143 int i; 144 char *name = NULL; 145 146 for (i = 0; i < ARRAY_SIZE(srp_rport_role_names); i++) 147 if (srp_rport_role_names[i].value == rport->roles) { 148 name = srp_rport_role_names[i].name; 149 break; 150 } 151 return sprintf(buf, "%s\n", name ? : "unknown"); 152 } 153 154 static DEVICE_ATTR(roles, S_IRUGO, show_srp_rport_roles, NULL); 155 156 static ssize_t store_srp_rport_delete(struct device *dev, 157 struct device_attribute *attr, 158 const char *buf, size_t count) 159 { 160 struct srp_rport *rport = transport_class_to_srp_rport(dev); 161 struct Scsi_Host *shost = dev_to_shost(dev); 162 struct srp_internal *i = to_srp_internal(shost->transportt); 163 164 if (i->f->rport_delete) { 165 i->f->rport_delete(rport); 166 return count; 167 } else { 168 return -ENOSYS; 169 } 170 } 171 172 static DEVICE_ATTR(delete, S_IWUSR, NULL, store_srp_rport_delete); 173 174 static ssize_t show_srp_rport_state(struct device *dev, 175 struct device_attribute *attr, 176 char *buf) 177 { 178 static const char *const state_name[] = { 179 [SRP_RPORT_RUNNING] = "running", 180 [SRP_RPORT_BLOCKED] = "blocked", 181 [SRP_RPORT_FAIL_FAST] = "fail-fast", 182 [SRP_RPORT_LOST] = "lost", 183 }; 184 struct srp_rport *rport = transport_class_to_srp_rport(dev); 185 enum srp_rport_state state = rport->state; 186 187 return sprintf(buf, "%s\n", 188 (unsigned)state < ARRAY_SIZE(state_name) ? 189 state_name[state] : "???"); 190 } 191 192 static DEVICE_ATTR(state, S_IRUGO, show_srp_rport_state, NULL); 193 194 static ssize_t srp_show_tmo(char *buf, int tmo) 195 { 196 return tmo >= 0 ? sprintf(buf, "%d\n", tmo) : sprintf(buf, "off\n"); 197 } 198 199 int srp_parse_tmo(int *tmo, const char *buf) 200 { 201 int res = 0; 202 203 if (strncmp(buf, "off", 3) != 0) 204 res = kstrtoint(buf, 0, tmo); 205 else 206 *tmo = -1; 207 208 return res; 209 } 210 EXPORT_SYMBOL(srp_parse_tmo); 211 212 static ssize_t show_reconnect_delay(struct device *dev, 213 struct device_attribute *attr, char *buf) 214 { 215 struct srp_rport *rport = transport_class_to_srp_rport(dev); 216 217 return srp_show_tmo(buf, rport->reconnect_delay); 218 } 219 220 static ssize_t store_reconnect_delay(struct device *dev, 221 struct device_attribute *attr, 222 const char *buf, const size_t count) 223 { 224 struct srp_rport *rport = transport_class_to_srp_rport(dev); 225 int res, delay; 226 227 res = srp_parse_tmo(&delay, buf); 228 if (res) 229 goto out; 230 res = srp_tmo_valid(delay, rport->fast_io_fail_tmo, 231 rport->dev_loss_tmo); 232 if (res) 233 goto out; 234 235 if (rport->reconnect_delay <= 0 && delay > 0 && 236 rport->state != SRP_RPORT_RUNNING) { 237 queue_delayed_work(system_long_wq, &rport->reconnect_work, 238 delay * HZ); 239 } else if (delay <= 0) { 240 cancel_delayed_work(&rport->reconnect_work); 241 } 242 rport->reconnect_delay = delay; 243 res = count; 244 245 out: 246 return res; 247 } 248 249 static DEVICE_ATTR(reconnect_delay, S_IRUGO | S_IWUSR, show_reconnect_delay, 250 store_reconnect_delay); 251 252 static ssize_t show_failed_reconnects(struct device *dev, 253 struct device_attribute *attr, char *buf) 254 { 255 struct srp_rport *rport = transport_class_to_srp_rport(dev); 256 257 return sprintf(buf, "%d\n", rport->failed_reconnects); 258 } 259 260 static DEVICE_ATTR(failed_reconnects, S_IRUGO, show_failed_reconnects, NULL); 261 262 static ssize_t show_srp_rport_fast_io_fail_tmo(struct device *dev, 263 struct device_attribute *attr, 264 char *buf) 265 { 266 struct srp_rport *rport = transport_class_to_srp_rport(dev); 267 268 return srp_show_tmo(buf, rport->fast_io_fail_tmo); 269 } 270 271 static ssize_t store_srp_rport_fast_io_fail_tmo(struct device *dev, 272 struct device_attribute *attr, 273 const char *buf, size_t count) 274 { 275 struct srp_rport *rport = transport_class_to_srp_rport(dev); 276 int res; 277 int fast_io_fail_tmo; 278 279 res = srp_parse_tmo(&fast_io_fail_tmo, buf); 280 if (res) 281 goto out; 282 res = srp_tmo_valid(rport->reconnect_delay, fast_io_fail_tmo, 283 rport->dev_loss_tmo); 284 if (res) 285 goto out; 286 rport->fast_io_fail_tmo = fast_io_fail_tmo; 287 res = count; 288 289 out: 290 return res; 291 } 292 293 static DEVICE_ATTR(fast_io_fail_tmo, S_IRUGO | S_IWUSR, 294 show_srp_rport_fast_io_fail_tmo, 295 store_srp_rport_fast_io_fail_tmo); 296 297 static ssize_t show_srp_rport_dev_loss_tmo(struct device *dev, 298 struct device_attribute *attr, 299 char *buf) 300 { 301 struct srp_rport *rport = transport_class_to_srp_rport(dev); 302 303 return srp_show_tmo(buf, rport->dev_loss_tmo); 304 } 305 306 static ssize_t store_srp_rport_dev_loss_tmo(struct device *dev, 307 struct device_attribute *attr, 308 const char *buf, size_t count) 309 { 310 struct srp_rport *rport = transport_class_to_srp_rport(dev); 311 int res; 312 int dev_loss_tmo; 313 314 res = srp_parse_tmo(&dev_loss_tmo, buf); 315 if (res) 316 goto out; 317 res = srp_tmo_valid(rport->reconnect_delay, rport->fast_io_fail_tmo, 318 dev_loss_tmo); 319 if (res) 320 goto out; 321 rport->dev_loss_tmo = dev_loss_tmo; 322 res = count; 323 324 out: 325 return res; 326 } 327 328 static DEVICE_ATTR(dev_loss_tmo, S_IRUGO | S_IWUSR, 329 show_srp_rport_dev_loss_tmo, 330 store_srp_rport_dev_loss_tmo); 331 332 static int srp_rport_set_state(struct srp_rport *rport, 333 enum srp_rport_state new_state) 334 { 335 enum srp_rport_state old_state = rport->state; 336 337 lockdep_assert_held(&rport->mutex); 338 339 switch (new_state) { 340 case SRP_RPORT_RUNNING: 341 switch (old_state) { 342 case SRP_RPORT_LOST: 343 goto invalid; 344 default: 345 break; 346 } 347 break; 348 case SRP_RPORT_BLOCKED: 349 switch (old_state) { 350 case SRP_RPORT_RUNNING: 351 break; 352 default: 353 goto invalid; 354 } 355 break; 356 case SRP_RPORT_FAIL_FAST: 357 switch (old_state) { 358 case SRP_RPORT_LOST: 359 goto invalid; 360 default: 361 break; 362 } 363 break; 364 case SRP_RPORT_LOST: 365 break; 366 } 367 rport->state = new_state; 368 return 0; 369 370 invalid: 371 return -EINVAL; 372 } 373 374 /** 375 * srp_reconnect_work() - reconnect and schedule a new attempt if necessary 376 * @work: Work structure used for scheduling this operation. 377 */ 378 static void srp_reconnect_work(struct work_struct *work) 379 { 380 struct srp_rport *rport = container_of(to_delayed_work(work), 381 struct srp_rport, reconnect_work); 382 struct Scsi_Host *shost = rport_to_shost(rport); 383 int delay, res; 384 385 res = srp_reconnect_rport(rport); 386 if (res != 0) { 387 shost_printk(KERN_ERR, shost, 388 "reconnect attempt %d failed (%d)\n", 389 ++rport->failed_reconnects, res); 390 delay = rport->reconnect_delay * 391 min(100, max(1, rport->failed_reconnects - 10)); 392 if (delay > 0) 393 queue_delayed_work(system_long_wq, 394 &rport->reconnect_work, delay * HZ); 395 } 396 } 397 398 static void __rport_fail_io_fast(struct srp_rport *rport) 399 { 400 struct Scsi_Host *shost = rport_to_shost(rport); 401 struct srp_internal *i; 402 403 lockdep_assert_held(&rport->mutex); 404 405 if (srp_rport_set_state(rport, SRP_RPORT_FAIL_FAST)) 406 return; 407 /* 408 * Call scsi_target_block() to wait for ongoing shost->queuecommand() 409 * calls before invoking i->f->terminate_rport_io(). 410 */ 411 scsi_target_block(rport->dev.parent); 412 scsi_target_unblock(rport->dev.parent, SDEV_TRANSPORT_OFFLINE); 413 414 /* Involve the LLD if possible to terminate all I/O on the rport. */ 415 i = to_srp_internal(shost->transportt); 416 if (i->f->terminate_rport_io) 417 i->f->terminate_rport_io(rport); 418 } 419 420 /** 421 * rport_fast_io_fail_timedout() - fast I/O failure timeout handler 422 * @work: Work structure used for scheduling this operation. 423 */ 424 static void rport_fast_io_fail_timedout(struct work_struct *work) 425 { 426 struct srp_rport *rport = container_of(to_delayed_work(work), 427 struct srp_rport, fast_io_fail_work); 428 struct Scsi_Host *shost = rport_to_shost(rport); 429 430 pr_info("fast_io_fail_tmo expired for SRP %s / %s.\n", 431 dev_name(&rport->dev), dev_name(&shost->shost_gendev)); 432 433 mutex_lock(&rport->mutex); 434 if (rport->state == SRP_RPORT_BLOCKED) 435 __rport_fail_io_fast(rport); 436 mutex_unlock(&rport->mutex); 437 } 438 439 /** 440 * rport_dev_loss_timedout() - device loss timeout handler 441 * @work: Work structure used for scheduling this operation. 442 */ 443 static void rport_dev_loss_timedout(struct work_struct *work) 444 { 445 struct srp_rport *rport = container_of(to_delayed_work(work), 446 struct srp_rport, dev_loss_work); 447 struct Scsi_Host *shost = rport_to_shost(rport); 448 struct srp_internal *i = to_srp_internal(shost->transportt); 449 450 pr_info("dev_loss_tmo expired for SRP %s / %s.\n", 451 dev_name(&rport->dev), dev_name(&shost->shost_gendev)); 452 453 mutex_lock(&rport->mutex); 454 WARN_ON(srp_rport_set_state(rport, SRP_RPORT_LOST) != 0); 455 scsi_target_unblock(rport->dev.parent, SDEV_TRANSPORT_OFFLINE); 456 mutex_unlock(&rport->mutex); 457 458 i->f->rport_delete(rport); 459 } 460 461 static void __srp_start_tl_fail_timers(struct srp_rport *rport) 462 { 463 struct Scsi_Host *shost = rport_to_shost(rport); 464 int delay, fast_io_fail_tmo, dev_loss_tmo; 465 466 lockdep_assert_held(&rport->mutex); 467 468 delay = rport->reconnect_delay; 469 fast_io_fail_tmo = rport->fast_io_fail_tmo; 470 dev_loss_tmo = rport->dev_loss_tmo; 471 pr_debug("%s current state: %d\n", dev_name(&shost->shost_gendev), 472 rport->state); 473 474 if (rport->state == SRP_RPORT_LOST) 475 return; 476 if (delay > 0) 477 queue_delayed_work(system_long_wq, &rport->reconnect_work, 478 1UL * delay * HZ); 479 if ((fast_io_fail_tmo >= 0 || dev_loss_tmo >= 0) && 480 srp_rport_set_state(rport, SRP_RPORT_BLOCKED) == 0) { 481 pr_debug("%s new state: %d\n", dev_name(&shost->shost_gendev), 482 rport->state); 483 scsi_target_block(&shost->shost_gendev); 484 if (fast_io_fail_tmo >= 0) 485 queue_delayed_work(system_long_wq, 486 &rport->fast_io_fail_work, 487 1UL * fast_io_fail_tmo * HZ); 488 if (dev_loss_tmo >= 0) 489 queue_delayed_work(system_long_wq, 490 &rport->dev_loss_work, 491 1UL * dev_loss_tmo * HZ); 492 } 493 } 494 495 /** 496 * srp_start_tl_fail_timers() - start the transport layer failure timers 497 * @rport: SRP target port. 498 * 499 * Start the transport layer fast I/O failure and device loss timers. Do not 500 * modify a timer that was already started. 501 */ 502 void srp_start_tl_fail_timers(struct srp_rport *rport) 503 { 504 mutex_lock(&rport->mutex); 505 __srp_start_tl_fail_timers(rport); 506 mutex_unlock(&rport->mutex); 507 } 508 EXPORT_SYMBOL(srp_start_tl_fail_timers); 509 510 /** 511 * srp_reconnect_rport() - reconnect to an SRP target port 512 * @rport: SRP target port. 513 * 514 * Blocks SCSI command queueing before invoking reconnect() such that 515 * queuecommand() won't be invoked concurrently with reconnect() from outside 516 * the SCSI EH. This is important since a reconnect() implementation may 517 * reallocate resources needed by queuecommand(). 518 * 519 * Notes: 520 * - This function neither waits until outstanding requests have finished nor 521 * tries to abort these. It is the responsibility of the reconnect() 522 * function to finish outstanding commands before reconnecting to the target 523 * port. 524 * - It is the responsibility of the caller to ensure that the resources 525 * reallocated by the reconnect() function won't be used while this function 526 * is in progress. One possible strategy is to invoke this function from 527 * the context of the SCSI EH thread only. Another possible strategy is to 528 * lock the rport mutex inside each SCSI LLD callback that can be invoked by 529 * the SCSI EH (the scsi_host_template.eh_*() functions and also the 530 * scsi_host_template.queuecommand() function). 531 */ 532 int srp_reconnect_rport(struct srp_rport *rport) 533 { 534 struct Scsi_Host *shost = rport_to_shost(rport); 535 struct srp_internal *i = to_srp_internal(shost->transportt); 536 struct scsi_device *sdev; 537 int res; 538 539 pr_debug("SCSI host %s\n", dev_name(&shost->shost_gendev)); 540 541 res = mutex_lock_interruptible(&rport->mutex); 542 if (res) 543 goto out; 544 scsi_target_block(&shost->shost_gendev); 545 res = rport->state != SRP_RPORT_LOST ? i->f->reconnect(rport) : -ENODEV; 546 pr_debug("%s (state %d): transport.reconnect() returned %d\n", 547 dev_name(&shost->shost_gendev), rport->state, res); 548 if (res == 0) { 549 cancel_delayed_work(&rport->fast_io_fail_work); 550 cancel_delayed_work(&rport->dev_loss_work); 551 552 rport->failed_reconnects = 0; 553 srp_rport_set_state(rport, SRP_RPORT_RUNNING); 554 scsi_target_unblock(&shost->shost_gendev, SDEV_RUNNING); 555 /* 556 * If the SCSI error handler has offlined one or more devices, 557 * invoking scsi_target_unblock() won't change the state of 558 * these devices into running so do that explicitly. 559 */ 560 shost_for_each_device(sdev, shost) { 561 mutex_lock(&sdev->state_mutex); 562 if (sdev->sdev_state == SDEV_OFFLINE) 563 sdev->sdev_state = SDEV_RUNNING; 564 mutex_unlock(&sdev->state_mutex); 565 } 566 } else if (rport->state == SRP_RPORT_RUNNING) { 567 /* 568 * srp_reconnect_rport() has been invoked with fast_io_fail 569 * and dev_loss off. Mark the port as failed and start the TL 570 * failure timers if these had not yet been started. 571 */ 572 __rport_fail_io_fast(rport); 573 scsi_target_unblock(&shost->shost_gendev, 574 SDEV_TRANSPORT_OFFLINE); 575 __srp_start_tl_fail_timers(rport); 576 } else if (rport->state != SRP_RPORT_BLOCKED) { 577 scsi_target_unblock(&shost->shost_gendev, 578 SDEV_TRANSPORT_OFFLINE); 579 } 580 mutex_unlock(&rport->mutex); 581 582 out: 583 return res; 584 } 585 EXPORT_SYMBOL(srp_reconnect_rport); 586 587 /** 588 * srp_timed_out() - SRP transport intercept of the SCSI timeout EH 589 * @scmd: SCSI command. 590 * 591 * If a timeout occurs while an rport is in the blocked state, ask the SCSI 592 * EH to continue waiting (BLK_EH_RESET_TIMER). Otherwise let the SCSI core 593 * handle the timeout (BLK_EH_DONE). 594 * 595 * Note: This function is called from soft-IRQ context and with the request 596 * queue lock held. 597 */ 598 enum blk_eh_timer_return srp_timed_out(struct scsi_cmnd *scmd) 599 { 600 struct scsi_device *sdev = scmd->device; 601 struct Scsi_Host *shost = sdev->host; 602 struct srp_internal *i = to_srp_internal(shost->transportt); 603 struct srp_rport *rport = shost_to_rport(shost); 604 605 pr_debug("timeout for sdev %s\n", dev_name(&sdev->sdev_gendev)); 606 return rport && rport->fast_io_fail_tmo < 0 && 607 rport->dev_loss_tmo < 0 && 608 i->f->reset_timer_if_blocked && scsi_device_blocked(sdev) ? 609 BLK_EH_RESET_TIMER : BLK_EH_DONE; 610 } 611 EXPORT_SYMBOL(srp_timed_out); 612 613 static void srp_rport_release(struct device *dev) 614 { 615 struct srp_rport *rport = dev_to_rport(dev); 616 617 put_device(dev->parent); 618 kfree(rport); 619 } 620 621 static int scsi_is_srp_rport(const struct device *dev) 622 { 623 return dev->release == srp_rport_release; 624 } 625 626 static int srp_rport_match(struct attribute_container *cont, 627 struct device *dev) 628 { 629 struct Scsi_Host *shost; 630 struct srp_internal *i; 631 632 if (!scsi_is_srp_rport(dev)) 633 return 0; 634 635 shost = dev_to_shost(dev->parent); 636 if (!shost->transportt) 637 return 0; 638 if (shost->transportt->host_attrs.ac.class != &srp_host_class.class) 639 return 0; 640 641 i = to_srp_internal(shost->transportt); 642 return &i->rport_attr_cont.ac == cont; 643 } 644 645 static int srp_host_match(struct attribute_container *cont, struct device *dev) 646 { 647 struct Scsi_Host *shost; 648 struct srp_internal *i; 649 650 if (!scsi_is_host_device(dev)) 651 return 0; 652 653 shost = dev_to_shost(dev); 654 if (!shost->transportt) 655 return 0; 656 if (shost->transportt->host_attrs.ac.class != &srp_host_class.class) 657 return 0; 658 659 i = to_srp_internal(shost->transportt); 660 return &i->t.host_attrs.ac == cont; 661 } 662 663 /** 664 * srp_rport_get() - increment rport reference count 665 * @rport: SRP target port. 666 */ 667 void srp_rport_get(struct srp_rport *rport) 668 { 669 get_device(&rport->dev); 670 } 671 EXPORT_SYMBOL(srp_rport_get); 672 673 /** 674 * srp_rport_put() - decrement rport reference count 675 * @rport: SRP target port. 676 */ 677 void srp_rport_put(struct srp_rport *rport) 678 { 679 put_device(&rport->dev); 680 } 681 EXPORT_SYMBOL(srp_rport_put); 682 683 /** 684 * srp_rport_add - add a SRP remote port to the device hierarchy 685 * @shost: scsi host the remote port is connected to. 686 * @ids: The port id for the remote port. 687 * 688 * Publishes a port to the rest of the system. 689 */ 690 struct srp_rport *srp_rport_add(struct Scsi_Host *shost, 691 struct srp_rport_identifiers *ids) 692 { 693 struct srp_rport *rport; 694 struct device *parent = &shost->shost_gendev; 695 struct srp_internal *i = to_srp_internal(shost->transportt); 696 int id, ret; 697 698 rport = kzalloc(sizeof(*rport), GFP_KERNEL); 699 if (!rport) 700 return ERR_PTR(-ENOMEM); 701 702 mutex_init(&rport->mutex); 703 704 device_initialize(&rport->dev); 705 706 rport->dev.parent = get_device(parent); 707 rport->dev.release = srp_rport_release; 708 709 memcpy(rport->port_id, ids->port_id, sizeof(rport->port_id)); 710 rport->roles = ids->roles; 711 712 if (i->f->reconnect) 713 rport->reconnect_delay = i->f->reconnect_delay ? 714 *i->f->reconnect_delay : 10; 715 INIT_DELAYED_WORK(&rport->reconnect_work, srp_reconnect_work); 716 rport->fast_io_fail_tmo = i->f->fast_io_fail_tmo ? 717 *i->f->fast_io_fail_tmo : 15; 718 rport->dev_loss_tmo = i->f->dev_loss_tmo ? *i->f->dev_loss_tmo : 60; 719 INIT_DELAYED_WORK(&rport->fast_io_fail_work, 720 rport_fast_io_fail_timedout); 721 INIT_DELAYED_WORK(&rport->dev_loss_work, rport_dev_loss_timedout); 722 723 id = atomic_inc_return(&to_srp_host_attrs(shost)->next_port_id); 724 dev_set_name(&rport->dev, "port-%d:%d", shost->host_no, id); 725 726 transport_setup_device(&rport->dev); 727 728 ret = device_add(&rport->dev); 729 if (ret) { 730 transport_destroy_device(&rport->dev); 731 put_device(&rport->dev); 732 return ERR_PTR(ret); 733 } 734 735 transport_add_device(&rport->dev); 736 transport_configure_device(&rport->dev); 737 738 return rport; 739 } 740 EXPORT_SYMBOL_GPL(srp_rport_add); 741 742 /** 743 * srp_rport_del - remove a SRP remote port 744 * @rport: SRP remote port to remove 745 * 746 * Removes the specified SRP remote port. 747 */ 748 void srp_rport_del(struct srp_rport *rport) 749 { 750 struct device *dev = &rport->dev; 751 752 transport_remove_device(dev); 753 device_del(dev); 754 transport_destroy_device(dev); 755 756 put_device(dev); 757 } 758 EXPORT_SYMBOL_GPL(srp_rport_del); 759 760 static int do_srp_rport_del(struct device *dev, void *data) 761 { 762 if (scsi_is_srp_rport(dev)) 763 srp_rport_del(dev_to_rport(dev)); 764 return 0; 765 } 766 767 /** 768 * srp_remove_host - tear down a Scsi_Host's SRP data structures 769 * @shost: Scsi Host that is torn down 770 * 771 * Removes all SRP remote ports for a given Scsi_Host. 772 * Must be called just before scsi_remove_host for SRP HBAs. 773 */ 774 void srp_remove_host(struct Scsi_Host *shost) 775 { 776 device_for_each_child(&shost->shost_gendev, NULL, do_srp_rport_del); 777 } 778 EXPORT_SYMBOL_GPL(srp_remove_host); 779 780 /** 781 * srp_stop_rport_timers - stop the transport layer recovery timers 782 * @rport: SRP remote port for which to stop the timers. 783 * 784 * Must be called after srp_remove_host() and scsi_remove_host(). The caller 785 * must hold a reference on the rport (rport->dev) and on the SCSI host 786 * (rport->dev.parent). 787 */ 788 void srp_stop_rport_timers(struct srp_rport *rport) 789 { 790 mutex_lock(&rport->mutex); 791 if (rport->state == SRP_RPORT_BLOCKED) 792 __rport_fail_io_fast(rport); 793 srp_rport_set_state(rport, SRP_RPORT_LOST); 794 mutex_unlock(&rport->mutex); 795 796 cancel_delayed_work_sync(&rport->reconnect_work); 797 cancel_delayed_work_sync(&rport->fast_io_fail_work); 798 cancel_delayed_work_sync(&rport->dev_loss_work); 799 } 800 EXPORT_SYMBOL_GPL(srp_stop_rport_timers); 801 802 /** 803 * srp_attach_transport - instantiate SRP transport template 804 * @ft: SRP transport class function template 805 */ 806 struct scsi_transport_template * 807 srp_attach_transport(struct srp_function_template *ft) 808 { 809 int count; 810 struct srp_internal *i; 811 812 i = kzalloc(sizeof(*i), GFP_KERNEL); 813 if (!i) 814 return NULL; 815 816 i->t.host_size = sizeof(struct srp_host_attrs); 817 i->t.host_attrs.ac.attrs = &i->host_attrs[0]; 818 i->t.host_attrs.ac.class = &srp_host_class.class; 819 i->t.host_attrs.ac.match = srp_host_match; 820 i->host_attrs[0] = NULL; 821 transport_container_register(&i->t.host_attrs); 822 823 i->rport_attr_cont.ac.attrs = &i->rport_attrs[0]; 824 i->rport_attr_cont.ac.class = &srp_rport_class.class; 825 i->rport_attr_cont.ac.match = srp_rport_match; 826 827 count = 0; 828 i->rport_attrs[count++] = &dev_attr_port_id; 829 i->rport_attrs[count++] = &dev_attr_roles; 830 if (ft->has_rport_state) { 831 i->rport_attrs[count++] = &dev_attr_state; 832 i->rport_attrs[count++] = &dev_attr_fast_io_fail_tmo; 833 i->rport_attrs[count++] = &dev_attr_dev_loss_tmo; 834 } 835 if (ft->reconnect) { 836 i->rport_attrs[count++] = &dev_attr_reconnect_delay; 837 i->rport_attrs[count++] = &dev_attr_failed_reconnects; 838 } 839 if (ft->rport_delete) 840 i->rport_attrs[count++] = &dev_attr_delete; 841 i->rport_attrs[count++] = NULL; 842 BUG_ON(count > ARRAY_SIZE(i->rport_attrs)); 843 844 transport_container_register(&i->rport_attr_cont); 845 846 i->f = ft; 847 848 return &i->t; 849 } 850 EXPORT_SYMBOL_GPL(srp_attach_transport); 851 852 /** 853 * srp_release_transport - release SRP transport template instance 854 * @t: transport template instance 855 */ 856 void srp_release_transport(struct scsi_transport_template *t) 857 { 858 struct srp_internal *i = to_srp_internal(t); 859 860 transport_container_unregister(&i->t.host_attrs); 861 transport_container_unregister(&i->rport_attr_cont); 862 863 kfree(i); 864 } 865 EXPORT_SYMBOL_GPL(srp_release_transport); 866 867 static __init int srp_transport_init(void) 868 { 869 int ret; 870 871 ret = transport_class_register(&srp_host_class); 872 if (ret) 873 return ret; 874 ret = transport_class_register(&srp_rport_class); 875 if (ret) 876 goto unregister_host_class; 877 878 return 0; 879 unregister_host_class: 880 transport_class_unregister(&srp_host_class); 881 return ret; 882 } 883 884 static void __exit srp_transport_exit(void) 885 { 886 transport_class_unregister(&srp_host_class); 887 transport_class_unregister(&srp_rport_class); 888 } 889 890 MODULE_AUTHOR("FUJITA Tomonori"); 891 MODULE_DESCRIPTION("SRP Transport Attributes"); 892 MODULE_LICENSE("GPL"); 893 894 module_init(srp_transport_init); 895 module_exit(srp_transport_exit); 896