1 /* 2 * Generic SCSI-3 ALUA SCSI Device Handler 3 * 4 * Copyright (C) 2007, 2008 Hannes Reinecke, SUSE Linux Products GmbH. 5 * All rights reserved. 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License as published by 9 * the Free Software Foundation; either version 2 of the License, or 10 * (at your option) any later version. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program; if not, write to the Free Software 19 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 20 * 21 */ 22 #include <scsi/scsi.h> 23 #include <scsi/scsi_eh.h> 24 #include <scsi/scsi_dh.h> 25 26 #define ALUA_DH_NAME "alua" 27 #define ALUA_DH_VER "1.2" 28 29 #define TPGS_STATE_OPTIMIZED 0x0 30 #define TPGS_STATE_NONOPTIMIZED 0x1 31 #define TPGS_STATE_STANDBY 0x2 32 #define TPGS_STATE_UNAVAILABLE 0x3 33 #define TPGS_STATE_OFFLINE 0xe 34 #define TPGS_STATE_TRANSITIONING 0xf 35 36 #define TPGS_SUPPORT_NONE 0x00 37 #define TPGS_SUPPORT_OPTIMIZED 0x01 38 #define TPGS_SUPPORT_NONOPTIMIZED 0x02 39 #define TPGS_SUPPORT_STANDBY 0x04 40 #define TPGS_SUPPORT_UNAVAILABLE 0x08 41 #define TPGS_SUPPORT_OFFLINE 0x40 42 #define TPGS_SUPPORT_TRANSITION 0x80 43 44 #define TPGS_MODE_UNINITIALIZED -1 45 #define TPGS_MODE_NONE 0x0 46 #define TPGS_MODE_IMPLICIT 0x1 47 #define TPGS_MODE_EXPLICIT 0x2 48 49 #define ALUA_INQUIRY_SIZE 36 50 #define ALUA_FAILOVER_TIMEOUT (60 * HZ) 51 #define ALUA_FAILOVER_RETRIES 5 52 53 struct alua_dh_data { 54 int group_id; 55 int rel_port; 56 int tpgs; 57 int state; 58 unsigned char inq[ALUA_INQUIRY_SIZE]; 59 unsigned char *buff; 60 int bufflen; 61 unsigned char sense[SCSI_SENSE_BUFFERSIZE]; 62 int senselen; 63 struct scsi_device *sdev; 64 activate_complete callback_fn; 65 void *callback_data; 66 }; 67 68 #define ALUA_POLICY_SWITCH_CURRENT 0 69 #define ALUA_POLICY_SWITCH_ALL 1 70 71 static char print_alua_state(int); 72 static int alua_check_sense(struct scsi_device *, struct scsi_sense_hdr *); 73 74 static inline struct alua_dh_data *get_alua_data(struct scsi_device *sdev) 75 { 76 struct scsi_dh_data *scsi_dh_data = sdev->scsi_dh_data; 77 BUG_ON(scsi_dh_data == NULL); 78 return ((struct alua_dh_data *) scsi_dh_data->buf); 79 } 80 81 static int realloc_buffer(struct alua_dh_data *h, unsigned len) 82 { 83 if (h->buff && h->buff != h->inq) 84 kfree(h->buff); 85 86 h->buff = kmalloc(len, GFP_NOIO); 87 if (!h->buff) { 88 h->buff = h->inq; 89 h->bufflen = ALUA_INQUIRY_SIZE; 90 return 1; 91 } 92 h->bufflen = len; 93 return 0; 94 } 95 96 static struct request *get_alua_req(struct scsi_device *sdev, 97 void *buffer, unsigned buflen, int rw) 98 { 99 struct request *rq; 100 struct request_queue *q = sdev->request_queue; 101 102 rq = blk_get_request(q, rw, GFP_NOIO); 103 104 if (!rq) { 105 sdev_printk(KERN_INFO, sdev, 106 "%s: blk_get_request failed\n", __func__); 107 return NULL; 108 } 109 110 if (buflen && blk_rq_map_kern(q, rq, buffer, buflen, GFP_NOIO)) { 111 blk_put_request(rq); 112 sdev_printk(KERN_INFO, sdev, 113 "%s: blk_rq_map_kern failed\n", __func__); 114 return NULL; 115 } 116 117 rq->cmd_type = REQ_TYPE_BLOCK_PC; 118 rq->cmd_flags |= REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | 119 REQ_FAILFAST_DRIVER; 120 rq->retries = ALUA_FAILOVER_RETRIES; 121 rq->timeout = ALUA_FAILOVER_TIMEOUT; 122 123 return rq; 124 } 125 126 /* 127 * submit_std_inquiry - Issue a standard INQUIRY command 128 * @sdev: sdev the command should be send to 129 */ 130 static int submit_std_inquiry(struct scsi_device *sdev, struct alua_dh_data *h) 131 { 132 struct request *rq; 133 int err = SCSI_DH_RES_TEMP_UNAVAIL; 134 135 rq = get_alua_req(sdev, h->inq, ALUA_INQUIRY_SIZE, READ); 136 if (!rq) 137 goto done; 138 139 /* Prepare the command. */ 140 rq->cmd[0] = INQUIRY; 141 rq->cmd[1] = 0; 142 rq->cmd[2] = 0; 143 rq->cmd[4] = ALUA_INQUIRY_SIZE; 144 rq->cmd_len = COMMAND_SIZE(INQUIRY); 145 146 rq->sense = h->sense; 147 memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE); 148 rq->sense_len = h->senselen = 0; 149 150 err = blk_execute_rq(rq->q, NULL, rq, 1); 151 if (err == -EIO) { 152 sdev_printk(KERN_INFO, sdev, 153 "%s: std inquiry failed with %x\n", 154 ALUA_DH_NAME, rq->errors); 155 h->senselen = rq->sense_len; 156 err = SCSI_DH_IO; 157 } 158 blk_put_request(rq); 159 done: 160 return err; 161 } 162 163 /* 164 * submit_vpd_inquiry - Issue an INQUIRY VPD page 0x83 command 165 * @sdev: sdev the command should be sent to 166 */ 167 static int submit_vpd_inquiry(struct scsi_device *sdev, struct alua_dh_data *h) 168 { 169 struct request *rq; 170 int err = SCSI_DH_RES_TEMP_UNAVAIL; 171 172 rq = get_alua_req(sdev, h->buff, h->bufflen, READ); 173 if (!rq) 174 goto done; 175 176 /* Prepare the command. */ 177 rq->cmd[0] = INQUIRY; 178 rq->cmd[1] = 1; 179 rq->cmd[2] = 0x83; 180 rq->cmd[4] = h->bufflen; 181 rq->cmd_len = COMMAND_SIZE(INQUIRY); 182 183 rq->sense = h->sense; 184 memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE); 185 rq->sense_len = h->senselen = 0; 186 187 err = blk_execute_rq(rq->q, NULL, rq, 1); 188 if (err == -EIO) { 189 sdev_printk(KERN_INFO, sdev, 190 "%s: evpd inquiry failed with %x\n", 191 ALUA_DH_NAME, rq->errors); 192 h->senselen = rq->sense_len; 193 err = SCSI_DH_IO; 194 } 195 blk_put_request(rq); 196 done: 197 return err; 198 } 199 200 /* 201 * submit_rtpg - Issue a REPORT TARGET GROUP STATES command 202 * @sdev: sdev the command should be sent to 203 */ 204 static unsigned submit_rtpg(struct scsi_device *sdev, struct alua_dh_data *h) 205 { 206 struct request *rq; 207 int err = SCSI_DH_RES_TEMP_UNAVAIL; 208 209 rq = get_alua_req(sdev, h->buff, h->bufflen, READ); 210 if (!rq) 211 goto done; 212 213 /* Prepare the command. */ 214 rq->cmd[0] = MAINTENANCE_IN; 215 rq->cmd[1] = MI_REPORT_TARGET_PGS; 216 rq->cmd[6] = (h->bufflen >> 24) & 0xff; 217 rq->cmd[7] = (h->bufflen >> 16) & 0xff; 218 rq->cmd[8] = (h->bufflen >> 8) & 0xff; 219 rq->cmd[9] = h->bufflen & 0xff; 220 rq->cmd_len = COMMAND_SIZE(MAINTENANCE_IN); 221 222 rq->sense = h->sense; 223 memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE); 224 rq->sense_len = h->senselen = 0; 225 226 err = blk_execute_rq(rq->q, NULL, rq, 1); 227 if (err == -EIO) { 228 sdev_printk(KERN_INFO, sdev, 229 "%s: rtpg failed with %x\n", 230 ALUA_DH_NAME, rq->errors); 231 h->senselen = rq->sense_len; 232 err = SCSI_DH_IO; 233 } 234 blk_put_request(rq); 235 done: 236 return err; 237 } 238 239 /* 240 * alua_stpg - Evaluate SET TARGET GROUP STATES 241 * @sdev: the device to be evaluated 242 * @state: the new target group state 243 * 244 * Send a SET TARGET GROUP STATES command to the device. 245 * We only have to test here if we should resubmit the command; 246 * any other error is assumed as a failure. 247 */ 248 static void stpg_endio(struct request *req, int error) 249 { 250 struct alua_dh_data *h = req->end_io_data; 251 struct scsi_sense_hdr sense_hdr; 252 unsigned err = SCSI_DH_IO; 253 254 if (error || host_byte(req->errors) != DID_OK || 255 msg_byte(req->errors) != COMMAND_COMPLETE) 256 goto done; 257 258 if (err == SCSI_DH_IO && h->senselen > 0) { 259 err = scsi_normalize_sense(h->sense, SCSI_SENSE_BUFFERSIZE, 260 &sense_hdr); 261 if (!err) { 262 err = SCSI_DH_IO; 263 goto done; 264 } 265 err = alua_check_sense(h->sdev, &sense_hdr); 266 if (err == ADD_TO_MLQUEUE) { 267 err = SCSI_DH_RETRY; 268 goto done; 269 } 270 sdev_printk(KERN_INFO, h->sdev, 271 "%s: stpg sense code: %02x/%02x/%02x\n", 272 ALUA_DH_NAME, sense_hdr.sense_key, 273 sense_hdr.asc, sense_hdr.ascq); 274 err = SCSI_DH_IO; 275 } 276 if (err == SCSI_DH_OK) { 277 h->state = TPGS_STATE_OPTIMIZED; 278 sdev_printk(KERN_INFO, h->sdev, 279 "%s: port group %02x switched to state %c\n", 280 ALUA_DH_NAME, h->group_id, 281 print_alua_state(h->state)); 282 } 283 done: 284 blk_put_request(req); 285 if (h->callback_fn) { 286 h->callback_fn(h->callback_data, err); 287 h->callback_fn = h->callback_data = NULL; 288 } 289 return; 290 } 291 292 /* 293 * submit_stpg - Issue a SET TARGET GROUP STATES command 294 * 295 * Currently we're only setting the current target port group state 296 * to 'active/optimized' and let the array firmware figure out 297 * the states of the remaining groups. 298 */ 299 static unsigned submit_stpg(struct alua_dh_data *h) 300 { 301 struct request *rq; 302 int err = SCSI_DH_RES_TEMP_UNAVAIL; 303 int stpg_len = 8; 304 struct scsi_device *sdev = h->sdev; 305 306 /* Prepare the data buffer */ 307 memset(h->buff, 0, stpg_len); 308 h->buff[4] = TPGS_STATE_OPTIMIZED & 0x0f; 309 h->buff[6] = (h->group_id >> 8) & 0xff; 310 h->buff[7] = h->group_id & 0xff; 311 312 rq = get_alua_req(sdev, h->buff, stpg_len, WRITE); 313 if (!rq) 314 return SCSI_DH_RES_TEMP_UNAVAIL; 315 316 /* Prepare the command. */ 317 rq->cmd[0] = MAINTENANCE_OUT; 318 rq->cmd[1] = MO_SET_TARGET_PGS; 319 rq->cmd[6] = (stpg_len >> 24) & 0xff; 320 rq->cmd[7] = (stpg_len >> 16) & 0xff; 321 rq->cmd[8] = (stpg_len >> 8) & 0xff; 322 rq->cmd[9] = stpg_len & 0xff; 323 rq->cmd_len = COMMAND_SIZE(MAINTENANCE_OUT); 324 325 rq->sense = h->sense; 326 memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE); 327 rq->sense_len = h->senselen = 0; 328 rq->end_io_data = h; 329 330 blk_execute_rq_nowait(rq->q, NULL, rq, 1, stpg_endio); 331 return err; 332 } 333 334 /* 335 * alua_std_inquiry - Evaluate standard INQUIRY command 336 * @sdev: device to be checked 337 * 338 * Just extract the TPGS setting to find out if ALUA 339 * is supported. 340 */ 341 static int alua_std_inquiry(struct scsi_device *sdev, struct alua_dh_data *h) 342 { 343 int err; 344 345 err = submit_std_inquiry(sdev, h); 346 347 if (err != SCSI_DH_OK) 348 return err; 349 350 /* Check TPGS setting */ 351 h->tpgs = (h->inq[5] >> 4) & 0x3; 352 switch (h->tpgs) { 353 case TPGS_MODE_EXPLICIT|TPGS_MODE_IMPLICIT: 354 sdev_printk(KERN_INFO, sdev, 355 "%s: supports implicit and explicit TPGS\n", 356 ALUA_DH_NAME); 357 break; 358 case TPGS_MODE_EXPLICIT: 359 sdev_printk(KERN_INFO, sdev, "%s: supports explicit TPGS\n", 360 ALUA_DH_NAME); 361 break; 362 case TPGS_MODE_IMPLICIT: 363 sdev_printk(KERN_INFO, sdev, "%s: supports implicit TPGS\n", 364 ALUA_DH_NAME); 365 break; 366 default: 367 h->tpgs = TPGS_MODE_NONE; 368 sdev_printk(KERN_INFO, sdev, "%s: not supported\n", 369 ALUA_DH_NAME); 370 err = SCSI_DH_DEV_UNSUPP; 371 break; 372 } 373 374 return err; 375 } 376 377 /* 378 * alua_vpd_inquiry - Evaluate INQUIRY vpd page 0x83 379 * @sdev: device to be checked 380 * 381 * Extract the relative target port and the target port group 382 * descriptor from the list of identificators. 383 */ 384 static int alua_vpd_inquiry(struct scsi_device *sdev, struct alua_dh_data *h) 385 { 386 int len; 387 unsigned err; 388 unsigned char *d; 389 390 retry: 391 err = submit_vpd_inquiry(sdev, h); 392 393 if (err != SCSI_DH_OK) 394 return err; 395 396 /* Check if vpd page exceeds initial buffer */ 397 len = (h->buff[2] << 8) + h->buff[3] + 4; 398 if (len > h->bufflen) { 399 /* Resubmit with the correct length */ 400 if (realloc_buffer(h, len)) { 401 sdev_printk(KERN_WARNING, sdev, 402 "%s: kmalloc buffer failed\n", 403 ALUA_DH_NAME); 404 /* Temporary failure, bypass */ 405 return SCSI_DH_DEV_TEMP_BUSY; 406 } 407 goto retry; 408 } 409 410 /* 411 * Now look for the correct descriptor. 412 */ 413 d = h->buff + 4; 414 while (d < h->buff + len) { 415 switch (d[1] & 0xf) { 416 case 0x4: 417 /* Relative target port */ 418 h->rel_port = (d[6] << 8) + d[7]; 419 break; 420 case 0x5: 421 /* Target port group */ 422 h->group_id = (d[6] << 8) + d[7]; 423 break; 424 default: 425 break; 426 } 427 d += d[3] + 4; 428 } 429 430 if (h->group_id == -1) { 431 /* 432 * Internal error; TPGS supported but required 433 * VPD identification descriptors not present. 434 * Disable ALUA support 435 */ 436 sdev_printk(KERN_INFO, sdev, 437 "%s: No target port descriptors found\n", 438 ALUA_DH_NAME); 439 h->state = TPGS_STATE_OPTIMIZED; 440 h->tpgs = TPGS_MODE_NONE; 441 err = SCSI_DH_DEV_UNSUPP; 442 } else { 443 sdev_printk(KERN_INFO, sdev, 444 "%s: port group %02x rel port %02x\n", 445 ALUA_DH_NAME, h->group_id, h->rel_port); 446 } 447 448 return err; 449 } 450 451 static char print_alua_state(int state) 452 { 453 switch (state) { 454 case TPGS_STATE_OPTIMIZED: 455 return 'A'; 456 case TPGS_STATE_NONOPTIMIZED: 457 return 'N'; 458 case TPGS_STATE_STANDBY: 459 return 'S'; 460 case TPGS_STATE_UNAVAILABLE: 461 return 'U'; 462 case TPGS_STATE_OFFLINE: 463 return 'O'; 464 case TPGS_STATE_TRANSITIONING: 465 return 'T'; 466 default: 467 return 'X'; 468 } 469 } 470 471 static int alua_check_sense(struct scsi_device *sdev, 472 struct scsi_sense_hdr *sense_hdr) 473 { 474 switch (sense_hdr->sense_key) { 475 case NOT_READY: 476 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0a) 477 /* 478 * LUN Not Accessible - ALUA state transition 479 */ 480 return ADD_TO_MLQUEUE; 481 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0b) 482 /* 483 * LUN Not Accessible -- Target port in standby state 484 */ 485 return SUCCESS; 486 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0c) 487 /* 488 * LUN Not Accessible -- Target port in unavailable state 489 */ 490 return SUCCESS; 491 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x12) 492 /* 493 * LUN Not Ready -- Offline 494 */ 495 return SUCCESS; 496 break; 497 case UNIT_ATTENTION: 498 if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00) 499 /* 500 * Power On, Reset, or Bus Device Reset, just retry. 501 */ 502 return ADD_TO_MLQUEUE; 503 if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x06) { 504 /* 505 * ALUA state changed 506 */ 507 return ADD_TO_MLQUEUE; 508 } 509 if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x07) { 510 /* 511 * Implicit ALUA state transition failed 512 */ 513 return ADD_TO_MLQUEUE; 514 } 515 if (sense_hdr->asc == 0x3f && sense_hdr->ascq == 0x0e) { 516 /* 517 * REPORTED_LUNS_DATA_HAS_CHANGED is reported 518 * when switching controllers on targets like 519 * Intel Multi-Flex. We can just retry. 520 */ 521 return ADD_TO_MLQUEUE; 522 } 523 524 break; 525 } 526 527 return SCSI_RETURN_NOT_HANDLED; 528 } 529 530 /* 531 * alua_rtpg - Evaluate REPORT TARGET GROUP STATES 532 * @sdev: the device to be evaluated. 533 * 534 * Evaluate the Target Port Group State. 535 * Returns SCSI_DH_DEV_OFFLINED if the path is 536 * found to be unuseable. 537 */ 538 static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h) 539 { 540 struct scsi_sense_hdr sense_hdr; 541 int len, k, off, valid_states = 0; 542 char *ucp; 543 unsigned err; 544 545 retry: 546 err = submit_rtpg(sdev, h); 547 548 if (err == SCSI_DH_IO && h->senselen > 0) { 549 err = scsi_normalize_sense(h->sense, SCSI_SENSE_BUFFERSIZE, 550 &sense_hdr); 551 if (!err) 552 return SCSI_DH_IO; 553 554 err = alua_check_sense(sdev, &sense_hdr); 555 if (err == ADD_TO_MLQUEUE) 556 goto retry; 557 sdev_printk(KERN_INFO, sdev, 558 "%s: rtpg sense code %02x/%02x/%02x\n", 559 ALUA_DH_NAME, sense_hdr.sense_key, 560 sense_hdr.asc, sense_hdr.ascq); 561 err = SCSI_DH_IO; 562 } 563 if (err != SCSI_DH_OK) 564 return err; 565 566 len = (h->buff[0] << 24) + (h->buff[1] << 16) + 567 (h->buff[2] << 8) + h->buff[3] + 4; 568 569 if (len > h->bufflen) { 570 /* Resubmit with the correct length */ 571 if (realloc_buffer(h, len)) { 572 sdev_printk(KERN_WARNING, sdev, 573 "%s: kmalloc buffer failed\n",__func__); 574 /* Temporary failure, bypass */ 575 return SCSI_DH_DEV_TEMP_BUSY; 576 } 577 goto retry; 578 } 579 580 for (k = 4, ucp = h->buff + 4; k < len; k += off, ucp += off) { 581 if (h->group_id == (ucp[2] << 8) + ucp[3]) { 582 h->state = ucp[0] & 0x0f; 583 valid_states = ucp[1]; 584 } 585 off = 8 + (ucp[7] * 4); 586 } 587 588 sdev_printk(KERN_INFO, sdev, 589 "%s: port group %02x state %c supports %c%c%c%c%c%c\n", 590 ALUA_DH_NAME, h->group_id, print_alua_state(h->state), 591 valid_states&TPGS_SUPPORT_TRANSITION?'T':'t', 592 valid_states&TPGS_SUPPORT_OFFLINE?'O':'o', 593 valid_states&TPGS_SUPPORT_UNAVAILABLE?'U':'u', 594 valid_states&TPGS_SUPPORT_STANDBY?'S':'s', 595 valid_states&TPGS_SUPPORT_NONOPTIMIZED?'N':'n', 596 valid_states&TPGS_SUPPORT_OPTIMIZED?'A':'a'); 597 598 if (h->tpgs & TPGS_MODE_EXPLICIT) { 599 switch (h->state) { 600 case TPGS_STATE_TRANSITIONING: 601 /* State transition, retry */ 602 goto retry; 603 break; 604 case TPGS_STATE_OFFLINE: 605 /* Path is offline, fail */ 606 err = SCSI_DH_DEV_OFFLINED; 607 break; 608 default: 609 break; 610 } 611 } else { 612 /* Only Implicit ALUA support */ 613 if (h->state == TPGS_STATE_OPTIMIZED || 614 h->state == TPGS_STATE_NONOPTIMIZED || 615 h->state == TPGS_STATE_STANDBY) 616 /* Useable path if active */ 617 err = SCSI_DH_OK; 618 else 619 /* Path unuseable for unavailable/offline */ 620 err = SCSI_DH_DEV_OFFLINED; 621 } 622 return err; 623 } 624 625 /* 626 * alua_initialize - Initialize ALUA state 627 * @sdev: the device to be initialized 628 * 629 * For the prep_fn to work correctly we have 630 * to initialize the ALUA state for the device. 631 */ 632 static int alua_initialize(struct scsi_device *sdev, struct alua_dh_data *h) 633 { 634 int err; 635 636 err = alua_std_inquiry(sdev, h); 637 if (err != SCSI_DH_OK) 638 goto out; 639 640 err = alua_vpd_inquiry(sdev, h); 641 if (err != SCSI_DH_OK) 642 goto out; 643 644 err = alua_rtpg(sdev, h); 645 if (err != SCSI_DH_OK) 646 goto out; 647 648 out: 649 return err; 650 } 651 652 /* 653 * alua_activate - activate a path 654 * @sdev: device on the path to be activated 655 * 656 * We're currently switching the port group to be activated only and 657 * let the array figure out the rest. 658 * There may be other arrays which require us to switch all port groups 659 * based on a certain policy. But until we actually encounter them it 660 * should be okay. 661 */ 662 static int alua_activate(struct scsi_device *sdev, 663 activate_complete fn, void *data) 664 { 665 struct alua_dh_data *h = get_alua_data(sdev); 666 int err = SCSI_DH_OK; 667 668 if (h->group_id != -1) { 669 err = alua_rtpg(sdev, h); 670 if (err != SCSI_DH_OK) 671 goto out; 672 } 673 674 if (h->tpgs & TPGS_MODE_EXPLICIT && h->state != TPGS_STATE_OPTIMIZED) { 675 h->callback_fn = fn; 676 h->callback_data = data; 677 err = submit_stpg(h); 678 if (err == SCSI_DH_OK) 679 return 0; 680 h->callback_fn = h->callback_data = NULL; 681 } 682 683 out: 684 if (fn) 685 fn(data, err); 686 return 0; 687 } 688 689 /* 690 * alua_prep_fn - request callback 691 * 692 * Fail I/O to all paths not in state 693 * active/optimized or active/non-optimized. 694 */ 695 static int alua_prep_fn(struct scsi_device *sdev, struct request *req) 696 { 697 struct alua_dh_data *h = get_alua_data(sdev); 698 int ret = BLKPREP_OK; 699 700 if (h->state != TPGS_STATE_OPTIMIZED && 701 h->state != TPGS_STATE_NONOPTIMIZED) { 702 ret = BLKPREP_KILL; 703 req->cmd_flags |= REQ_QUIET; 704 } 705 return ret; 706 707 } 708 709 static const struct scsi_dh_devlist alua_dev_list[] = { 710 {"HP", "MSA VOLUME" }, 711 {"HP", "HSV101" }, 712 {"HP", "HSV111" }, 713 {"HP", "HSV200" }, 714 {"HP", "HSV210" }, 715 {"HP", "HSV300" }, 716 {"IBM", "2107900" }, 717 {"IBM", "2145" }, 718 {"Pillar", "Axiom" }, 719 {"Intel", "Multi-Flex"}, 720 {NULL, NULL} 721 }; 722 723 static int alua_bus_attach(struct scsi_device *sdev); 724 static void alua_bus_detach(struct scsi_device *sdev); 725 726 static struct scsi_device_handler alua_dh = { 727 .name = ALUA_DH_NAME, 728 .module = THIS_MODULE, 729 .devlist = alua_dev_list, 730 .attach = alua_bus_attach, 731 .detach = alua_bus_detach, 732 .prep_fn = alua_prep_fn, 733 .check_sense = alua_check_sense, 734 .activate = alua_activate, 735 }; 736 737 /* 738 * alua_bus_attach - Attach device handler 739 * @sdev: device to be attached to 740 */ 741 static int alua_bus_attach(struct scsi_device *sdev) 742 { 743 struct scsi_dh_data *scsi_dh_data; 744 struct alua_dh_data *h; 745 unsigned long flags; 746 int err = SCSI_DH_OK; 747 748 scsi_dh_data = kzalloc(sizeof(struct scsi_device_handler *) 749 + sizeof(*h) , GFP_KERNEL); 750 if (!scsi_dh_data) { 751 sdev_printk(KERN_ERR, sdev, "%s: Attach failed\n", 752 ALUA_DH_NAME); 753 return -ENOMEM; 754 } 755 756 scsi_dh_data->scsi_dh = &alua_dh; 757 h = (struct alua_dh_data *) scsi_dh_data->buf; 758 h->tpgs = TPGS_MODE_UNINITIALIZED; 759 h->state = TPGS_STATE_OPTIMIZED; 760 h->group_id = -1; 761 h->rel_port = -1; 762 h->buff = h->inq; 763 h->bufflen = ALUA_INQUIRY_SIZE; 764 h->sdev = sdev; 765 766 err = alua_initialize(sdev, h); 767 if (err != SCSI_DH_OK) 768 goto failed; 769 770 if (!try_module_get(THIS_MODULE)) 771 goto failed; 772 773 spin_lock_irqsave(sdev->request_queue->queue_lock, flags); 774 sdev->scsi_dh_data = scsi_dh_data; 775 spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags); 776 777 return 0; 778 779 failed: 780 kfree(scsi_dh_data); 781 sdev_printk(KERN_ERR, sdev, "%s: not attached\n", ALUA_DH_NAME); 782 return -EINVAL; 783 } 784 785 /* 786 * alua_bus_detach - Detach device handler 787 * @sdev: device to be detached from 788 */ 789 static void alua_bus_detach(struct scsi_device *sdev) 790 { 791 struct scsi_dh_data *scsi_dh_data; 792 struct alua_dh_data *h; 793 unsigned long flags; 794 795 spin_lock_irqsave(sdev->request_queue->queue_lock, flags); 796 scsi_dh_data = sdev->scsi_dh_data; 797 sdev->scsi_dh_data = NULL; 798 spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags); 799 800 h = (struct alua_dh_data *) scsi_dh_data->buf; 801 if (h->buff && h->inq != h->buff) 802 kfree(h->buff); 803 kfree(scsi_dh_data); 804 module_put(THIS_MODULE); 805 sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", ALUA_DH_NAME); 806 } 807 808 static int __init alua_init(void) 809 { 810 int r; 811 812 r = scsi_register_device_handler(&alua_dh); 813 if (r != 0) 814 printk(KERN_ERR "%s: Failed to register scsi device handler", 815 ALUA_DH_NAME); 816 return r; 817 } 818 819 static void __exit alua_exit(void) 820 { 821 scsi_unregister_device_handler(&alua_dh); 822 } 823 824 module_init(alua_init); 825 module_exit(alua_exit); 826 827 MODULE_DESCRIPTION("DM Multipath ALUA support"); 828 MODULE_AUTHOR("Hannes Reinecke <hare@suse.de>"); 829 MODULE_LICENSE("GPL"); 830 MODULE_VERSION(ALUA_DH_VER); 831