1/* 2 * SCSI RDMA (SRP) transport class 3 * 4 * Copyright (C) 2007 FUJITA Tomonori <tomof@acm.org> 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License as 8 * published by the Free Software Foundation, version 2 of the 9 * License. 10 * 11 * This program is distributed in the hope that it will be useful, but 12 * WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 * General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software 18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 19 * 02110-1301 USA 20 */ 21#include <linux/init.h> 22#include <linux/module.h> 23#include <linux/jiffies.h> 24#include <linux/err.h> 25#include <linux/slab.h> 26#include <linux/string.h> 27#include <linux/delay.h> 28 29#include <scsi/scsi.h> 30#include <scsi/scsi_cmnd.h> 31#include <scsi/scsi_device.h> 32#include <scsi/scsi_host.h> 33#include <scsi/scsi_transport.h> 34#include <scsi/scsi_transport_srp.h> 35#include "scsi_priv.h" 36 37struct srp_host_attrs { 38 atomic_t next_port_id; 39}; 40#define to_srp_host_attrs(host) ((struct srp_host_attrs *)(host)->shost_data) 41 42#define SRP_HOST_ATTRS 0 43#define SRP_RPORT_ATTRS 8 44 45struct srp_internal { 46 struct scsi_transport_template t; 47 struct srp_function_template *f; 48 49 struct device_attribute *host_attrs[SRP_HOST_ATTRS + 1]; 50 51 struct device_attribute *rport_attrs[SRP_RPORT_ATTRS + 1]; 52 struct transport_container rport_attr_cont; 53}; 54 55#define to_srp_internal(tmpl) container_of(tmpl, struct srp_internal, t) 56 57#define dev_to_rport(d) container_of(d, struct srp_rport, dev) 58#define transport_class_to_srp_rport(dev) dev_to_rport((dev)->parent) 59static inline struct Scsi_Host *rport_to_shost(struct srp_rport *r) 60{ 61 return dev_to_shost(r->dev.parent); 62} 63 64static inline struct srp_rport *shost_to_rport(struct Scsi_Host *shost) 65{ 66 return transport_class_to_srp_rport(&shost->shost_gendev); 67} 68 69/** 70 * srp_tmo_valid() - check timeout combination validity 71 * @reconnect_delay: Reconnect delay in seconds. 72 * @fast_io_fail_tmo: Fast I/O fail timeout in seconds. 73 * @dev_loss_tmo: Device loss timeout in seconds. 74 * 75 * The combination of the timeout parameters must be such that SCSI commands 76 * are finished in a reasonable time. Hence do not allow the fast I/O fail 77 * timeout to exceed SCSI_DEVICE_BLOCK_MAX_TIMEOUT nor allow dev_loss_tmo to 78 * exceed that limit if failing I/O fast has been disabled. Furthermore, these 79 * parameters must be such that multipath can detect failed paths timely. 80 * Hence do not allow all three parameters to be disabled simultaneously. 81 */ 82int srp_tmo_valid(int reconnect_delay, int fast_io_fail_tmo, int dev_loss_tmo) 83{ 84 if (reconnect_delay < 0 && fast_io_fail_tmo < 0 && dev_loss_tmo < 0) 85 return -EINVAL; 86 if (reconnect_delay == 0) 87 return -EINVAL; 88 if (fast_io_fail_tmo > SCSI_DEVICE_BLOCK_MAX_TIMEOUT) 89 return -EINVAL; 90 if (fast_io_fail_tmo < 0 && 91 dev_loss_tmo > SCSI_DEVICE_BLOCK_MAX_TIMEOUT) 92 return -EINVAL; 93 if (dev_loss_tmo >= LONG_MAX / HZ) 94 return -EINVAL; 95 if (fast_io_fail_tmo >= 0 && dev_loss_tmo >= 0 && 96 fast_io_fail_tmo >= dev_loss_tmo) 97 return -EINVAL; 98 return 0; 99} 100EXPORT_SYMBOL_GPL(srp_tmo_valid); 101 102static int srp_host_setup(struct transport_container *tc, struct device *dev, 103 struct device *cdev) 104{ 105 struct Scsi_Host *shost = dev_to_shost(dev); 106 struct srp_host_attrs *srp_host = to_srp_host_attrs(shost); 107 108 atomic_set(&srp_host->next_port_id, 0); 109 return 0; 110} 111 112static DECLARE_TRANSPORT_CLASS(srp_host_class, "srp_host", srp_host_setup, 113 NULL, NULL); 114 115static DECLARE_TRANSPORT_CLASS(srp_rport_class, "srp_remote_ports", 116 NULL, NULL, NULL); 117 118#define SRP_PID(p) \ 119 (p)->port_id[0], (p)->port_id[1], (p)->port_id[2], (p)->port_id[3], \ 120 (p)->port_id[4], (p)->port_id[5], (p)->port_id[6], (p)->port_id[7], \ 121 (p)->port_id[8], (p)->port_id[9], (p)->port_id[10], (p)->port_id[11], \ 122 (p)->port_id[12], (p)->port_id[13], (p)->port_id[14], (p)->port_id[15] 123 124#define SRP_PID_FMT "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:" \ 125 "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x" 126 127static ssize_t 128show_srp_rport_id(struct device *dev, struct device_attribute *attr, 129 char *buf) 130{ 131 struct srp_rport *rport = transport_class_to_srp_rport(dev); 132 return sprintf(buf, SRP_PID_FMT "\n", SRP_PID(rport)); 133} 134 135static DEVICE_ATTR(port_id, S_IRUGO, show_srp_rport_id, NULL); 136 137static const struct { 138 u32 value; 139 char *name; 140} srp_rport_role_names[] = { 141 {SRP_RPORT_ROLE_INITIATOR, "SRP Initiator"}, 142 {SRP_RPORT_ROLE_TARGET, "SRP Target"}, 143}; 144 145static ssize_t 146show_srp_rport_roles(struct device *dev, struct device_attribute *attr, 147 char *buf) 148{ 149 struct srp_rport *rport = transport_class_to_srp_rport(dev); 150 int i; 151 char *name = NULL; 152 153 for (i = 0; i < ARRAY_SIZE(srp_rport_role_names); i++) 154 if (srp_rport_role_names[i].value == rport->roles) { 155 name = srp_rport_role_names[i].name; 156 break; 157 } 158 return sprintf(buf, "%s\n", name ? : "unknown"); 159} 160 161static DEVICE_ATTR(roles, S_IRUGO, show_srp_rport_roles, NULL); 162 163static ssize_t store_srp_rport_delete(struct device *dev, 164 struct device_attribute *attr, 165 const char *buf, size_t count) 166{ 167 struct srp_rport *rport = transport_class_to_srp_rport(dev); 168 struct Scsi_Host *shost = dev_to_shost(dev); 169 struct srp_internal *i = to_srp_internal(shost->transportt); 170 171 if (i->f->rport_delete) { 172 i->f->rport_delete(rport); 173 return count; 174 } else { 175 return -ENOSYS; 176 } 177} 178 179static DEVICE_ATTR(delete, S_IWUSR, NULL, store_srp_rport_delete); 180 181static ssize_t show_srp_rport_state(struct device *dev, 182 struct device_attribute *attr, 183 char *buf) 184{ 185 static const char *const state_name[] = { 186 [SRP_RPORT_RUNNING] = "running", 187 [SRP_RPORT_BLOCKED] = "blocked", 188 [SRP_RPORT_FAIL_FAST] = "fail-fast", 189 [SRP_RPORT_LOST] = "lost", 190 }; 191 struct srp_rport *rport = transport_class_to_srp_rport(dev); 192 enum srp_rport_state state = rport->state; 193 194 return sprintf(buf, "%s\n", 195 (unsigned)state < ARRAY_SIZE(state_name) ? 196 state_name[state] : "???"); 197} 198 199static DEVICE_ATTR(state, S_IRUGO, show_srp_rport_state, NULL); 200 201static ssize_t srp_show_tmo(char *buf, int tmo) 202{ 203 return tmo >= 0 ? sprintf(buf, "%d\n", tmo) : sprintf(buf, "off\n"); 204} 205 206int srp_parse_tmo(int *tmo, const char *buf) 207{ 208 int res = 0; 209 210 if (strncmp(buf, "off", 3) != 0) 211 res = kstrtoint(buf, 0, tmo); 212 else 213 *tmo = -1; 214 215 return res; 216} 217EXPORT_SYMBOL(srp_parse_tmo); 218 219static ssize_t show_reconnect_delay(struct device *dev, 220 struct device_attribute *attr, char *buf) 221{ 222 struct srp_rport *rport = transport_class_to_srp_rport(dev); 223 224 return srp_show_tmo(buf, rport->reconnect_delay); 225} 226 227static ssize_t store_reconnect_delay(struct device *dev, 228 struct device_attribute *attr, 229 const char *buf, const size_t count) 230{ 231 struct srp_rport *rport = transport_class_to_srp_rport(dev); 232 int res, delay; 233 234 res = srp_parse_tmo(&delay, buf); 235 if (res) 236 goto out; 237 res = srp_tmo_valid(delay, rport->fast_io_fail_tmo, 238 rport->dev_loss_tmo); 239 if (res) 240 goto out; 241 242 if (rport->reconnect_delay <= 0 && delay > 0 && 243 rport->state != SRP_RPORT_RUNNING) { 244 queue_delayed_work(system_long_wq, &rport->reconnect_work, 245 delay * HZ); 246 } else if (delay <= 0) { 247 cancel_delayed_work(&rport->reconnect_work); 248 } 249 rport->reconnect_delay = delay; 250 res = count; 251 252out: 253 return res; 254} 255 256static DEVICE_ATTR(reconnect_delay, S_IRUGO | S_IWUSR, show_reconnect_delay, 257 store_reconnect_delay); 258 259static ssize_t show_failed_reconnects(struct device *dev, 260 struct device_attribute *attr, char *buf) 261{ 262 struct srp_rport *rport = transport_class_to_srp_rport(dev); 263 264 return sprintf(buf, "%d\n", rport->failed_reconnects); 265} 266 267static DEVICE_ATTR(failed_reconnects, S_IRUGO, show_failed_reconnects, NULL); 268 269static ssize_t show_srp_rport_fast_io_fail_tmo(struct device *dev, 270 struct device_attribute *attr, 271 char *buf) 272{ 273 struct srp_rport *rport = transport_class_to_srp_rport(dev); 274 275 return srp_show_tmo(buf, rport->fast_io_fail_tmo); 276} 277 278static ssize_t store_srp_rport_fast_io_fail_tmo(struct device *dev, 279 struct device_attribute *attr, 280 const char *buf, size_t count) 281{ 282 struct srp_rport *rport = transport_class_to_srp_rport(dev); 283 int res; 284 int fast_io_fail_tmo; 285 286 res = srp_parse_tmo(&fast_io_fail_tmo, buf); 287 if (res) 288 goto out; 289 res = srp_tmo_valid(rport->reconnect_delay, fast_io_fail_tmo, 290 rport->dev_loss_tmo); 291 if (res) 292 goto out; 293 rport->fast_io_fail_tmo = fast_io_fail_tmo; 294 res = count; 295 296out: 297 return res; 298} 299 300static DEVICE_ATTR(fast_io_fail_tmo, S_IRUGO | S_IWUSR, 301 show_srp_rport_fast_io_fail_tmo, 302 store_srp_rport_fast_io_fail_tmo); 303 304static ssize_t show_srp_rport_dev_loss_tmo(struct device *dev, 305 struct device_attribute *attr, 306 char *buf) 307{ 308 struct srp_rport *rport = transport_class_to_srp_rport(dev); 309 310 return srp_show_tmo(buf, rport->dev_loss_tmo); 311} 312 313static ssize_t store_srp_rport_dev_loss_tmo(struct device *dev, 314 struct device_attribute *attr, 315 const char *buf, size_t count) 316{ 317 struct srp_rport *rport = transport_class_to_srp_rport(dev); 318 int res; 319 int dev_loss_tmo; 320 321 res = srp_parse_tmo(&dev_loss_tmo, buf); 322 if (res) 323 goto out; 324 res = srp_tmo_valid(rport->reconnect_delay, rport->fast_io_fail_tmo, 325 dev_loss_tmo); 326 if (res) 327 goto out; 328 rport->dev_loss_tmo = dev_loss_tmo; 329 res = count; 330 331out: 332 return res; 333} 334 335static DEVICE_ATTR(dev_loss_tmo, S_IRUGO | S_IWUSR, 336 show_srp_rport_dev_loss_tmo, 337 store_srp_rport_dev_loss_tmo); 338 339static int srp_rport_set_state(struct srp_rport *rport, 340 enum srp_rport_state new_state) 341{ 342 enum srp_rport_state old_state = rport->state; 343 344 lockdep_assert_held(&rport->mutex); 345 346 switch (new_state) { 347 case SRP_RPORT_RUNNING: 348 switch (old_state) { 349 case SRP_RPORT_LOST: 350 goto invalid; 351 default: 352 break; 353 } 354 break; 355 case SRP_RPORT_BLOCKED: 356 switch (old_state) { 357 case SRP_RPORT_RUNNING: 358 break; 359 default: 360 goto invalid; 361 } 362 break; 363 case SRP_RPORT_FAIL_FAST: 364 switch (old_state) { 365 case SRP_RPORT_LOST: 366 goto invalid; 367 default: 368 break; 369 } 370 break; 371 case SRP_RPORT_LOST: 372 break; 373 } 374 rport->state = new_state; 375 return 0; 376 377invalid: 378 return -EINVAL; 379} 380 381/** 382 * srp_reconnect_work() - reconnect and schedule a new attempt if necessary 383 * @work: Work structure used for scheduling this operation. 384 */ 385static void srp_reconnect_work(struct work_struct *work) 386{ 387 struct srp_rport *rport = container_of(to_delayed_work(work), 388 struct srp_rport, reconnect_work); 389 struct Scsi_Host *shost = rport_to_shost(rport); 390 int delay, res; 391 392 res = srp_reconnect_rport(rport); 393 if (res != 0) { 394 shost_printk(KERN_ERR, shost, 395 "reconnect attempt %d failed (%d)\n", 396 ++rport->failed_reconnects, res); 397 delay = rport->reconnect_delay * 398 min(100, max(1, rport->failed_reconnects - 10)); 399 if (delay > 0) 400 queue_delayed_work(system_long_wq, 401 &rport->reconnect_work, delay * HZ); 402 } 403} 404 405/** 406 * scsi_request_fn_active() - number of kernel threads inside scsi_request_fn() 407 * @shost: SCSI host for which to count the number of scsi_request_fn() callers. 408 * 409 * To do: add support for scsi-mq in this function. 410 */ 411static int scsi_request_fn_active(struct Scsi_Host *shost) 412{ 413 struct scsi_device *sdev; 414 struct request_queue *q; 415 int request_fn_active = 0; 416 417 shost_for_each_device(sdev, shost) { 418 q = sdev->request_queue; 419 420 spin_lock_irq(q->queue_lock); 421 request_fn_active += q->request_fn_active; 422 spin_unlock_irq(q->queue_lock); 423 } 424 425 return request_fn_active; 426} 427 428/* Wait until ongoing shost->hostt->queuecommand() calls have finished. */ 429static void srp_wait_for_queuecommand(struct Scsi_Host *shost) 430{ 431 while (scsi_request_fn_active(shost)) 432 msleep(20); 433} 434 435static void __rport_fail_io_fast(struct srp_rport *rport) 436{ 437 struct Scsi_Host *shost = rport_to_shost(rport); 438 struct srp_internal *i; 439 440 lockdep_assert_held(&rport->mutex); 441 442 if (srp_rport_set_state(rport, SRP_RPORT_FAIL_FAST)) 443 return; 444 scsi_target_unblock(rport->dev.parent, SDEV_TRANSPORT_OFFLINE); 445 446 /* Involve the LLD if possible to terminate all I/O on the rport. */ 447 i = to_srp_internal(shost->transportt); 448 if (i->f->terminate_rport_io) { 449 srp_wait_for_queuecommand(shost); 450 i->f->terminate_rport_io(rport); 451 } 452} 453 454/** 455 * rport_fast_io_fail_timedout() - fast I/O failure timeout handler 456 * @work: Work structure used for scheduling this operation. 457 */ 458static void rport_fast_io_fail_timedout(struct work_struct *work) 459{ 460 struct srp_rport *rport = container_of(to_delayed_work(work), 461 struct srp_rport, fast_io_fail_work); 462 struct Scsi_Host *shost = rport_to_shost(rport); 463 464 pr_info("fast_io_fail_tmo expired for SRP %s / %s.\n", 465 dev_name(&rport->dev), dev_name(&shost->shost_gendev)); 466 467 mutex_lock(&rport->mutex); 468 if (rport->state == SRP_RPORT_BLOCKED) 469 __rport_fail_io_fast(rport); 470 mutex_unlock(&rport->mutex); 471} 472 473/** 474 * rport_dev_loss_timedout() - device loss timeout handler 475 * @work: Work structure used for scheduling this operation. 476 */ 477static void rport_dev_loss_timedout(struct work_struct *work) 478{ 479 struct srp_rport *rport = container_of(to_delayed_work(work), 480 struct srp_rport, dev_loss_work); 481 struct Scsi_Host *shost = rport_to_shost(rport); 482 struct srp_internal *i = to_srp_internal(shost->transportt); 483 484 pr_info("dev_loss_tmo expired for SRP %s / %s.\n", 485 dev_name(&rport->dev), dev_name(&shost->shost_gendev)); 486 487 mutex_lock(&rport->mutex); 488 WARN_ON(srp_rport_set_state(rport, SRP_RPORT_LOST) != 0); 489 scsi_target_unblock(rport->dev.parent, SDEV_TRANSPORT_OFFLINE); 490 mutex_unlock(&rport->mutex); 491 492 i->f->rport_delete(rport); 493} 494 495static void __srp_start_tl_fail_timers(struct srp_rport *rport) 496{ 497 struct Scsi_Host *shost = rport_to_shost(rport); 498 int delay, fast_io_fail_tmo, dev_loss_tmo; 499 500 lockdep_assert_held(&rport->mutex); 501 502 delay = rport->reconnect_delay; 503 fast_io_fail_tmo = rport->fast_io_fail_tmo; 504 dev_loss_tmo = rport->dev_loss_tmo; 505 pr_debug("%s current state: %d\n", dev_name(&shost->shost_gendev), 506 rport->state); 507 508 if (rport->state == SRP_RPORT_LOST) 509 return; 510 if (delay > 0) 511 queue_delayed_work(system_long_wq, &rport->reconnect_work, 512 1UL * delay * HZ); 513 if ((fast_io_fail_tmo >= 0 || dev_loss_tmo >= 0) && 514 srp_rport_set_state(rport, SRP_RPORT_BLOCKED) == 0) { 515 pr_debug("%s new state: %d\n", dev_name(&shost->shost_gendev), 516 rport->state); 517 scsi_target_block(&shost->shost_gendev); 518 if (fast_io_fail_tmo >= 0) 519 queue_delayed_work(system_long_wq, 520 &rport->fast_io_fail_work, 521 1UL * fast_io_fail_tmo * HZ); 522 if (dev_loss_tmo >= 0) 523 queue_delayed_work(system_long_wq, 524 &rport->dev_loss_work, 525 1UL * dev_loss_tmo * HZ); 526 } 527} 528 529/** 530 * srp_start_tl_fail_timers() - start the transport layer failure timers 531 * @rport: SRP target port. 532 * 533 * Start the transport layer fast I/O failure and device loss timers. Do not 534 * modify a timer that was already started. 535 */ 536void srp_start_tl_fail_timers(struct srp_rport *rport) 537{ 538 mutex_lock(&rport->mutex); 539 __srp_start_tl_fail_timers(rport); 540 mutex_unlock(&rport->mutex); 541} 542EXPORT_SYMBOL(srp_start_tl_fail_timers); 543 544/** 545 * srp_reconnect_rport() - reconnect to an SRP target port 546 * @rport: SRP target port. 547 * 548 * Blocks SCSI command queueing before invoking reconnect() such that 549 * queuecommand() won't be invoked concurrently with reconnect() from outside 550 * the SCSI EH. This is important since a reconnect() implementation may 551 * reallocate resources needed by queuecommand(). 552 * 553 * Notes: 554 * - This function neither waits until outstanding requests have finished nor 555 * tries to abort these. It is the responsibility of the reconnect() 556 * function to finish outstanding commands before reconnecting to the target 557 * port. 558 * - It is the responsibility of the caller to ensure that the resources 559 * reallocated by the reconnect() function won't be used while this function 560 * is in progress. One possible strategy is to invoke this function from 561 * the context of the SCSI EH thread only. Another possible strategy is to 562 * lock the rport mutex inside each SCSI LLD callback that can be invoked by 563 * the SCSI EH (the scsi_host_template.eh_*() functions and also the 564 * scsi_host_template.queuecommand() function). 565 */ 566int srp_reconnect_rport(struct srp_rport *rport) 567{ 568 struct Scsi_Host *shost = rport_to_shost(rport); 569 struct srp_internal *i = to_srp_internal(shost->transportt); 570 struct scsi_device *sdev; 571 int res; 572 573 pr_debug("SCSI host %s\n", dev_name(&shost->shost_gendev)); 574 575 res = mutex_lock_interruptible(&rport->mutex); 576 if (res) 577 goto out; 578 scsi_target_block(&shost->shost_gendev); 579 srp_wait_for_queuecommand(shost); 580 res = rport->state != SRP_RPORT_LOST ? i->f->reconnect(rport) : -ENODEV; 581 pr_debug("%s (state %d): transport.reconnect() returned %d\n", 582 dev_name(&shost->shost_gendev), rport->state, res); 583 if (res == 0) { 584 cancel_delayed_work(&rport->fast_io_fail_work); 585 cancel_delayed_work(&rport->dev_loss_work); 586 587 rport->failed_reconnects = 0; 588 srp_rport_set_state(rport, SRP_RPORT_RUNNING); 589 scsi_target_unblock(&shost->shost_gendev, SDEV_RUNNING); 590 /* 591 * If the SCSI error handler has offlined one or more devices, 592 * invoking scsi_target_unblock() won't change the state of 593 * these devices into running so do that explicitly. 594 */ 595 spin_lock_irq(shost->host_lock); 596 __shost_for_each_device(sdev, shost) 597 if (sdev->sdev_state == SDEV_OFFLINE) 598 sdev->sdev_state = SDEV_RUNNING; 599 spin_unlock_irq(shost->host_lock); 600 } else if (rport->state == SRP_RPORT_RUNNING) { 601 /* 602 * srp_reconnect_rport() has been invoked with fast_io_fail 603 * and dev_loss off. Mark the port as failed and start the TL 604 * failure timers if these had not yet been started. 605 */ 606 __rport_fail_io_fast(rport); 607 scsi_target_unblock(&shost->shost_gendev, 608 SDEV_TRANSPORT_OFFLINE); 609 __srp_start_tl_fail_timers(rport); 610 } else if (rport->state != SRP_RPORT_BLOCKED) { 611 scsi_target_unblock(&shost->shost_gendev, 612 SDEV_TRANSPORT_OFFLINE); 613 } 614 mutex_unlock(&rport->mutex); 615 616out: 617 return res; 618} 619EXPORT_SYMBOL(srp_reconnect_rport); 620 621/** 622 * srp_timed_out() - SRP transport intercept of the SCSI timeout EH 623 * @scmd: SCSI command. 624 * 625 * If a timeout occurs while an rport is in the blocked state, ask the SCSI 626 * EH to continue waiting (BLK_EH_RESET_TIMER). Otherwise let the SCSI core 627 * handle the timeout (BLK_EH_NOT_HANDLED). 628 * 629 * Note: This function is called from soft-IRQ context and with the request 630 * queue lock held. 631 */ 632static enum blk_eh_timer_return srp_timed_out(struct scsi_cmnd *scmd) 633{ 634 struct scsi_device *sdev = scmd->device; 635 struct Scsi_Host *shost = sdev->host; 636 struct srp_internal *i = to_srp_internal(shost->transportt); 637 struct srp_rport *rport = shost_to_rport(shost); 638 639 pr_debug("timeout for sdev %s\n", dev_name(&sdev->sdev_gendev)); 640 return rport->fast_io_fail_tmo < 0 && rport->dev_loss_tmo < 0 && 641 i->f->reset_timer_if_blocked && scsi_device_blocked(sdev) ? 642 BLK_EH_RESET_TIMER : BLK_EH_NOT_HANDLED; 643} 644 645static void srp_rport_release(struct device *dev) 646{ 647 struct srp_rport *rport = dev_to_rport(dev); 648 649 put_device(dev->parent); 650 kfree(rport); 651} 652 653static int scsi_is_srp_rport(const struct device *dev) 654{ 655 return dev->release == srp_rport_release; 656} 657 658static int srp_rport_match(struct attribute_container *cont, 659 struct device *dev) 660{ 661 struct Scsi_Host *shost; 662 struct srp_internal *i; 663 664 if (!scsi_is_srp_rport(dev)) 665 return 0; 666 667 shost = dev_to_shost(dev->parent); 668 if (!shost->transportt) 669 return 0; 670 if (shost->transportt->host_attrs.ac.class != &srp_host_class.class) 671 return 0; 672 673 i = to_srp_internal(shost->transportt); 674 return &i->rport_attr_cont.ac == cont; 675} 676 677static int srp_host_match(struct attribute_container *cont, struct device *dev) 678{ 679 struct Scsi_Host *shost; 680 struct srp_internal *i; 681 682 if (!scsi_is_host_device(dev)) 683 return 0; 684 685 shost = dev_to_shost(dev); 686 if (!shost->transportt) 687 return 0; 688 if (shost->transportt->host_attrs.ac.class != &srp_host_class.class) 689 return 0; 690 691 i = to_srp_internal(shost->transportt); 692 return &i->t.host_attrs.ac == cont; 693} 694 695/** 696 * srp_rport_get() - increment rport reference count 697 * @rport: SRP target port. 698 */ 699void srp_rport_get(struct srp_rport *rport) 700{ 701 get_device(&rport->dev); 702} 703EXPORT_SYMBOL(srp_rport_get); 704 705/** 706 * srp_rport_put() - decrement rport reference count 707 * @rport: SRP target port. 708 */ 709void srp_rport_put(struct srp_rport *rport) 710{ 711 put_device(&rport->dev); 712} 713EXPORT_SYMBOL(srp_rport_put); 714 715/** 716 * srp_rport_add - add a SRP remote port to the device hierarchy 717 * @shost: scsi host the remote port is connected to. 718 * @ids: The port id for the remote port. 719 * 720 * Publishes a port to the rest of the system. 721 */ 722struct srp_rport *srp_rport_add(struct Scsi_Host *shost, 723 struct srp_rport_identifiers *ids) 724{ 725 struct srp_rport *rport; 726 struct device *parent = &shost->shost_gendev; 727 struct srp_internal *i = to_srp_internal(shost->transportt); 728 int id, ret; 729 730 rport = kzalloc(sizeof(*rport), GFP_KERNEL); 731 if (!rport) 732 return ERR_PTR(-ENOMEM); 733 734 mutex_init(&rport->mutex); 735 736 device_initialize(&rport->dev); 737 738 rport->dev.parent = get_device(parent); 739 rport->dev.release = srp_rport_release; 740 741 memcpy(rport->port_id, ids->port_id, sizeof(rport->port_id)); 742 rport->roles = ids->roles; 743 744 if (i->f->reconnect) 745 rport->reconnect_delay = i->f->reconnect_delay ? 746 *i->f->reconnect_delay : 10; 747 INIT_DELAYED_WORK(&rport->reconnect_work, srp_reconnect_work); 748 rport->fast_io_fail_tmo = i->f->fast_io_fail_tmo ? 749 *i->f->fast_io_fail_tmo : 15; 750 rport->dev_loss_tmo = i->f->dev_loss_tmo ? *i->f->dev_loss_tmo : 60; 751 INIT_DELAYED_WORK(&rport->fast_io_fail_work, 752 rport_fast_io_fail_timedout); 753 INIT_DELAYED_WORK(&rport->dev_loss_work, rport_dev_loss_timedout); 754 755 id = atomic_inc_return(&to_srp_host_attrs(shost)->next_port_id); 756 dev_set_name(&rport->dev, "port-%d:%d", shost->host_no, id); 757 758 transport_setup_device(&rport->dev); 759 760 ret = device_add(&rport->dev); 761 if (ret) { 762 transport_destroy_device(&rport->dev); 763 put_device(&rport->dev); 764 return ERR_PTR(ret); 765 } 766 767 transport_add_device(&rport->dev); 768 transport_configure_device(&rport->dev); 769 770 return rport; 771} 772EXPORT_SYMBOL_GPL(srp_rport_add); 773 774/** 775 * srp_rport_del - remove a SRP remote port 776 * @rport: SRP remote port to remove 777 * 778 * Removes the specified SRP remote port. 779 */ 780void srp_rport_del(struct srp_rport *rport) 781{ 782 struct device *dev = &rport->dev; 783 784 transport_remove_device(dev); 785 device_del(dev); 786 transport_destroy_device(dev); 787 788 put_device(dev); 789} 790EXPORT_SYMBOL_GPL(srp_rport_del); 791 792static int do_srp_rport_del(struct device *dev, void *data) 793{ 794 if (scsi_is_srp_rport(dev)) 795 srp_rport_del(dev_to_rport(dev)); 796 return 0; 797} 798 799/** 800 * srp_remove_host - tear down a Scsi_Host's SRP data structures 801 * @shost: Scsi Host that is torn down 802 * 803 * Removes all SRP remote ports for a given Scsi_Host. 804 * Must be called just before scsi_remove_host for SRP HBAs. 805 */ 806void srp_remove_host(struct Scsi_Host *shost) 807{ 808 device_for_each_child(&shost->shost_gendev, NULL, do_srp_rport_del); 809} 810EXPORT_SYMBOL_GPL(srp_remove_host); 811 812/** 813 * srp_stop_rport_timers - stop the transport layer recovery timers 814 * @rport: SRP remote port for which to stop the timers. 815 * 816 * Must be called after srp_remove_host() and scsi_remove_host(). The caller 817 * must hold a reference on the rport (rport->dev) and on the SCSI host 818 * (rport->dev.parent). 819 */ 820void srp_stop_rport_timers(struct srp_rport *rport) 821{ 822 mutex_lock(&rport->mutex); 823 if (rport->state == SRP_RPORT_BLOCKED) 824 __rport_fail_io_fast(rport); 825 srp_rport_set_state(rport, SRP_RPORT_LOST); 826 mutex_unlock(&rport->mutex); 827 828 cancel_delayed_work_sync(&rport->reconnect_work); 829 cancel_delayed_work_sync(&rport->fast_io_fail_work); 830 cancel_delayed_work_sync(&rport->dev_loss_work); 831} 832EXPORT_SYMBOL_GPL(srp_stop_rport_timers); 833 834static int srp_tsk_mgmt_response(struct Scsi_Host *shost, u64 nexus, u64 tm_id, 835 int result) 836{ 837 struct srp_internal *i = to_srp_internal(shost->transportt); 838 return i->f->tsk_mgmt_response(shost, nexus, tm_id, result); 839} 840 841static int srp_it_nexus_response(struct Scsi_Host *shost, u64 nexus, int result) 842{ 843 struct srp_internal *i = to_srp_internal(shost->transportt); 844 return i->f->it_nexus_response(shost, nexus, result); 845} 846 847/** 848 * srp_attach_transport - instantiate SRP transport template 849 * @ft: SRP transport class function template 850 */ 851struct scsi_transport_template * 852srp_attach_transport(struct srp_function_template *ft) 853{ 854 int count; 855 struct srp_internal *i; 856 857 i = kzalloc(sizeof(*i), GFP_KERNEL); 858 if (!i) 859 return NULL; 860 861 i->t.eh_timed_out = srp_timed_out; 862 863 i->t.tsk_mgmt_response = srp_tsk_mgmt_response; 864 i->t.it_nexus_response = srp_it_nexus_response; 865 866 i->t.host_size = sizeof(struct srp_host_attrs); 867 i->t.host_attrs.ac.attrs = &i->host_attrs[0]; 868 i->t.host_attrs.ac.class = &srp_host_class.class; 869 i->t.host_attrs.ac.match = srp_host_match; 870 i->host_attrs[0] = NULL; 871 transport_container_register(&i->t.host_attrs); 872 873 i->rport_attr_cont.ac.attrs = &i->rport_attrs[0]; 874 i->rport_attr_cont.ac.class = &srp_rport_class.class; 875 i->rport_attr_cont.ac.match = srp_rport_match; 876 877 count = 0; 878 i->rport_attrs[count++] = &dev_attr_port_id; 879 i->rport_attrs[count++] = &dev_attr_roles; 880 if (ft->has_rport_state) { 881 i->rport_attrs[count++] = &dev_attr_state; 882 i->rport_attrs[count++] = &dev_attr_fast_io_fail_tmo; 883 i->rport_attrs[count++] = &dev_attr_dev_loss_tmo; 884 } 885 if (ft->reconnect) { 886 i->rport_attrs[count++] = &dev_attr_reconnect_delay; 887 i->rport_attrs[count++] = &dev_attr_failed_reconnects; 888 } 889 if (ft->rport_delete) 890 i->rport_attrs[count++] = &dev_attr_delete; 891 i->rport_attrs[count++] = NULL; 892 BUG_ON(count > ARRAY_SIZE(i->rport_attrs)); 893 894 transport_container_register(&i->rport_attr_cont); 895 896 i->f = ft; 897 898 return &i->t; 899} 900EXPORT_SYMBOL_GPL(srp_attach_transport); 901 902/** 903 * srp_release_transport - release SRP transport template instance 904 * @t: transport template instance 905 */ 906void srp_release_transport(struct scsi_transport_template *t) 907{ 908 struct srp_internal *i = to_srp_internal(t); 909 910 transport_container_unregister(&i->t.host_attrs); 911 transport_container_unregister(&i->rport_attr_cont); 912 913 kfree(i); 914} 915EXPORT_SYMBOL_GPL(srp_release_transport); 916 917static __init int srp_transport_init(void) 918{ 919 int ret; 920 921 ret = transport_class_register(&srp_host_class); 922 if (ret) 923 return ret; 924 ret = transport_class_register(&srp_rport_class); 925 if (ret) 926 goto unregister_host_class; 927 928 return 0; 929unregister_host_class: 930 transport_class_unregister(&srp_host_class); 931 return ret; 932} 933 934static void __exit srp_transport_exit(void) 935{ 936 transport_class_unregister(&srp_host_class); 937 transport_class_unregister(&srp_rport_class); 938} 939 940MODULE_AUTHOR("FUJITA Tomonori"); 941MODULE_DESCRIPTION("SRP Transport Attributes"); 942MODULE_LICENSE("GPL"); 943 944module_init(srp_transport_init); 945module_exit(srp_transport_exit); 946