1 /* 2 * Generic SCSI-3 ALUA SCSI Device Handler 3 * 4 * Copyright (C) 2007-2010 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 <linux/slab.h> 23 #include <linux/delay.h> 24 #include <scsi/scsi.h> 25 #include <scsi/scsi_eh.h> 26 #include <scsi/scsi_dh.h> 27 28 #define ALUA_DH_NAME "alua" 29 #define ALUA_DH_VER "1.3" 30 31 #define TPGS_STATE_OPTIMIZED 0x0 32 #define TPGS_STATE_NONOPTIMIZED 0x1 33 #define TPGS_STATE_STANDBY 0x2 34 #define TPGS_STATE_UNAVAILABLE 0x3 35 #define TPGS_STATE_LBA_DEPENDENT 0x4 36 #define TPGS_STATE_OFFLINE 0xe 37 #define TPGS_STATE_TRANSITIONING 0xf 38 39 #define TPGS_SUPPORT_NONE 0x00 40 #define TPGS_SUPPORT_OPTIMIZED 0x01 41 #define TPGS_SUPPORT_NONOPTIMIZED 0x02 42 #define TPGS_SUPPORT_STANDBY 0x04 43 #define TPGS_SUPPORT_UNAVAILABLE 0x08 44 #define TPGS_SUPPORT_LBA_DEPENDENT 0x10 45 #define TPGS_SUPPORT_OFFLINE 0x40 46 #define TPGS_SUPPORT_TRANSITION 0x80 47 48 #define TPGS_MODE_UNINITIALIZED -1 49 #define TPGS_MODE_NONE 0x0 50 #define TPGS_MODE_IMPLICIT 0x1 51 #define TPGS_MODE_EXPLICIT 0x2 52 53 #define ALUA_INQUIRY_SIZE 36 54 #define ALUA_FAILOVER_TIMEOUT (60 * HZ) 55 #define ALUA_FAILOVER_RETRIES 5 56 57 struct alua_dh_data { 58 int group_id; 59 int rel_port; 60 int tpgs; 61 int state; 62 unsigned char inq[ALUA_INQUIRY_SIZE]; 63 unsigned char *buff; 64 int bufflen; 65 unsigned char sense[SCSI_SENSE_BUFFERSIZE]; 66 int senselen; 67 struct scsi_device *sdev; 68 activate_complete callback_fn; 69 void *callback_data; 70 }; 71 72 #define ALUA_POLICY_SWITCH_CURRENT 0 73 #define ALUA_POLICY_SWITCH_ALL 1 74 75 static char print_alua_state(int); 76 static int alua_check_sense(struct scsi_device *, struct scsi_sense_hdr *); 77 78 static inline struct alua_dh_data *get_alua_data(struct scsi_device *sdev) 79 { 80 struct scsi_dh_data *scsi_dh_data = sdev->scsi_dh_data; 81 BUG_ON(scsi_dh_data == NULL); 82 return ((struct alua_dh_data *) scsi_dh_data->buf); 83 } 84 85 static int realloc_buffer(struct alua_dh_data *h, unsigned len) 86 { 87 if (h->buff && h->buff != h->inq) 88 kfree(h->buff); 89 90 h->buff = kmalloc(len, GFP_NOIO); 91 if (!h->buff) { 92 h->buff = h->inq; 93 h->bufflen = ALUA_INQUIRY_SIZE; 94 return 1; 95 } 96 h->bufflen = len; 97 return 0; 98 } 99 100 static struct request *get_alua_req(struct scsi_device *sdev, 101 void *buffer, unsigned buflen, int rw) 102 { 103 struct request *rq; 104 struct request_queue *q = sdev->request_queue; 105 106 rq = blk_get_request(q, rw, GFP_NOIO); 107 108 if (!rq) { 109 sdev_printk(KERN_INFO, sdev, 110 "%s: blk_get_request failed\n", __func__); 111 return NULL; 112 } 113 114 if (buflen && blk_rq_map_kern(q, rq, buffer, buflen, GFP_NOIO)) { 115 blk_put_request(rq); 116 sdev_printk(KERN_INFO, sdev, 117 "%s: blk_rq_map_kern failed\n", __func__); 118 return NULL; 119 } 120 121 rq->cmd_type = REQ_TYPE_BLOCK_PC; 122 rq->cmd_flags |= REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | 123 REQ_FAILFAST_DRIVER; 124 rq->retries = ALUA_FAILOVER_RETRIES; 125 rq->timeout = ALUA_FAILOVER_TIMEOUT; 126 127 return rq; 128 } 129 130 /* 131 * submit_std_inquiry - Issue a standard INQUIRY command 132 * @sdev: sdev the command should be send to 133 */ 134 static int submit_std_inquiry(struct scsi_device *sdev, struct alua_dh_data *h) 135 { 136 struct request *rq; 137 int err = SCSI_DH_RES_TEMP_UNAVAIL; 138 139 rq = get_alua_req(sdev, h->inq, ALUA_INQUIRY_SIZE, READ); 140 if (!rq) 141 goto done; 142 143 /* Prepare the command. */ 144 rq->cmd[0] = INQUIRY; 145 rq->cmd[1] = 0; 146 rq->cmd[2] = 0; 147 rq->cmd[4] = ALUA_INQUIRY_SIZE; 148 rq->cmd_len = COMMAND_SIZE(INQUIRY); 149 150 rq->sense = h->sense; 151 memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE); 152 rq->sense_len = h->senselen = 0; 153 154 err = blk_execute_rq(rq->q, NULL, rq, 1); 155 if (err == -EIO) { 156 sdev_printk(KERN_INFO, sdev, 157 "%s: std inquiry failed with %x\n", 158 ALUA_DH_NAME, rq->errors); 159 h->senselen = rq->sense_len; 160 err = SCSI_DH_IO; 161 } 162 blk_put_request(rq); 163 done: 164 return err; 165 } 166 167 /* 168 * submit_vpd_inquiry - Issue an INQUIRY VPD page 0x83 command 169 * @sdev: sdev the command should be sent to 170 */ 171 static int submit_vpd_inquiry(struct scsi_device *sdev, struct alua_dh_data *h) 172 { 173 struct request *rq; 174 int err = SCSI_DH_RES_TEMP_UNAVAIL; 175 176 rq = get_alua_req(sdev, h->buff, h->bufflen, READ); 177 if (!rq) 178 goto done; 179 180 /* Prepare the command. */ 181 rq->cmd[0] = INQUIRY; 182 rq->cmd[1] = 1; 183 rq->cmd[2] = 0x83; 184 rq->cmd[4] = h->bufflen; 185 rq->cmd_len = COMMAND_SIZE(INQUIRY); 186 187 rq->sense = h->sense; 188 memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE); 189 rq->sense_len = h->senselen = 0; 190 191 err = blk_execute_rq(rq->q, NULL, rq, 1); 192 if (err == -EIO) { 193 sdev_printk(KERN_INFO, sdev, 194 "%s: evpd inquiry failed with %x\n", 195 ALUA_DH_NAME, rq->errors); 196 h->senselen = rq->sense_len; 197 err = SCSI_DH_IO; 198 } 199 blk_put_request(rq); 200 done: 201 return err; 202 } 203 204 /* 205 * submit_rtpg - Issue a REPORT TARGET GROUP STATES command 206 * @sdev: sdev the command should be sent to 207 */ 208 static unsigned submit_rtpg(struct scsi_device *sdev, struct alua_dh_data *h) 209 { 210 struct request *rq; 211 int err = SCSI_DH_RES_TEMP_UNAVAIL; 212 213 rq = get_alua_req(sdev, h->buff, h->bufflen, READ); 214 if (!rq) 215 goto done; 216 217 /* Prepare the command. */ 218 rq->cmd[0] = MAINTENANCE_IN; 219 rq->cmd[1] = MI_REPORT_TARGET_PGS; 220 rq->cmd[6] = (h->bufflen >> 24) & 0xff; 221 rq->cmd[7] = (h->bufflen >> 16) & 0xff; 222 rq->cmd[8] = (h->bufflen >> 8) & 0xff; 223 rq->cmd[9] = h->bufflen & 0xff; 224 rq->cmd_len = COMMAND_SIZE(MAINTENANCE_IN); 225 226 rq->sense = h->sense; 227 memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE); 228 rq->sense_len = h->senselen = 0; 229 230 err = blk_execute_rq(rq->q, NULL, rq, 1); 231 if (err == -EIO) { 232 sdev_printk(KERN_INFO, sdev, 233 "%s: rtpg failed with %x\n", 234 ALUA_DH_NAME, rq->errors); 235 h->senselen = rq->sense_len; 236 err = SCSI_DH_IO; 237 } 238 blk_put_request(rq); 239 done: 240 return err; 241 } 242 243 /* 244 * alua_stpg - Evaluate SET TARGET GROUP STATES 245 * @sdev: the device to be evaluated 246 * @state: the new target group state 247 * 248 * Send a SET TARGET GROUP STATES command to the device. 249 * We only have to test here if we should resubmit the command; 250 * any other error is assumed as a failure. 251 */ 252 static void stpg_endio(struct request *req, int error) 253 { 254 struct alua_dh_data *h = req->end_io_data; 255 struct scsi_sense_hdr sense_hdr; 256 unsigned err = SCSI_DH_OK; 257 258 if (error || host_byte(req->errors) != DID_OK || 259 msg_byte(req->errors) != COMMAND_COMPLETE) { 260 err = SCSI_DH_IO; 261 goto done; 262 } 263 264 if (h->senselen > 0) { 265 err = scsi_normalize_sense(h->sense, SCSI_SENSE_BUFFERSIZE, 266 &sense_hdr); 267 if (!err) { 268 err = SCSI_DH_IO; 269 goto done; 270 } 271 err = alua_check_sense(h->sdev, &sense_hdr); 272 if (err == ADD_TO_MLQUEUE) { 273 err = SCSI_DH_RETRY; 274 goto done; 275 } 276 sdev_printk(KERN_INFO, h->sdev, 277 "%s: stpg sense code: %02x/%02x/%02x\n", 278 ALUA_DH_NAME, sense_hdr.sense_key, 279 sense_hdr.asc, sense_hdr.ascq); 280 err = SCSI_DH_IO; 281 } 282 if (err == SCSI_DH_OK) { 283 h->state = TPGS_STATE_OPTIMIZED; 284 sdev_printk(KERN_INFO, h->sdev, 285 "%s: port group %02x switched to state %c\n", 286 ALUA_DH_NAME, h->group_id, 287 print_alua_state(h->state)); 288 } 289 done: 290 req->end_io_data = NULL; 291 __blk_put_request(req->q, req); 292 if (h->callback_fn) { 293 h->callback_fn(h->callback_data, err); 294 h->callback_fn = h->callback_data = NULL; 295 } 296 return; 297 } 298 299 /* 300 * submit_stpg - Issue a SET TARGET GROUP STATES command 301 * 302 * Currently we're only setting the current target port group state 303 * to 'active/optimized' and let the array firmware figure out 304 * the states of the remaining groups. 305 */ 306 static unsigned submit_stpg(struct alua_dh_data *h) 307 { 308 struct request *rq; 309 int stpg_len = 8; 310 struct scsi_device *sdev = h->sdev; 311 312 /* Prepare the data buffer */ 313 memset(h->buff, 0, stpg_len); 314 h->buff[4] = TPGS_STATE_OPTIMIZED & 0x0f; 315 h->buff[6] = (h->group_id >> 8) & 0xff; 316 h->buff[7] = h->group_id & 0xff; 317 318 rq = get_alua_req(sdev, h->buff, stpg_len, WRITE); 319 if (!rq) 320 return SCSI_DH_RES_TEMP_UNAVAIL; 321 322 /* Prepare the command. */ 323 rq->cmd[0] = MAINTENANCE_OUT; 324 rq->cmd[1] = MO_SET_TARGET_PGS; 325 rq->cmd[6] = (stpg_len >> 24) & 0xff; 326 rq->cmd[7] = (stpg_len >> 16) & 0xff; 327 rq->cmd[8] = (stpg_len >> 8) & 0xff; 328 rq->cmd[9] = stpg_len & 0xff; 329 rq->cmd_len = COMMAND_SIZE(MAINTENANCE_OUT); 330 331 rq->sense = h->sense; 332 memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE); 333 rq->sense_len = h->senselen = 0; 334 rq->end_io_data = h; 335 336 blk_execute_rq_nowait(rq->q, NULL, rq, 1, stpg_endio); 337 return SCSI_DH_OK; 338 } 339 340 /* 341 * alua_std_inquiry - Evaluate standard INQUIRY command 342 * @sdev: device to be checked 343 * 344 * Just extract the TPGS setting to find out if ALUA 345 * is supported. 346 */ 347 static int alua_std_inquiry(struct scsi_device *sdev, struct alua_dh_data *h) 348 { 349 int err; 350 351 err = submit_std_inquiry(sdev, h); 352 353 if (err != SCSI_DH_OK) 354 return err; 355 356 /* Check TPGS setting */ 357 h->tpgs = (h->inq[5] >> 4) & 0x3; 358 switch (h->tpgs) { 359 case TPGS_MODE_EXPLICIT|TPGS_MODE_IMPLICIT: 360 sdev_printk(KERN_INFO, sdev, 361 "%s: supports implicit and explicit TPGS\n", 362 ALUA_DH_NAME); 363 break; 364 case TPGS_MODE_EXPLICIT: 365 sdev_printk(KERN_INFO, sdev, "%s: supports explicit TPGS\n", 366 ALUA_DH_NAME); 367 break; 368 case TPGS_MODE_IMPLICIT: 369 sdev_printk(KERN_INFO, sdev, "%s: supports implicit TPGS\n", 370 ALUA_DH_NAME); 371 break; 372 default: 373 h->tpgs = TPGS_MODE_NONE; 374 sdev_printk(KERN_INFO, sdev, "%s: not supported\n", 375 ALUA_DH_NAME); 376 err = SCSI_DH_DEV_UNSUPP; 377 break; 378 } 379 380 return err; 381 } 382 383 /* 384 * alua_vpd_inquiry - Evaluate INQUIRY vpd page 0x83 385 * @sdev: device to be checked 386 * 387 * Extract the relative target port and the target port group 388 * descriptor from the list of identificators. 389 */ 390 static int alua_vpd_inquiry(struct scsi_device *sdev, struct alua_dh_data *h) 391 { 392 int len; 393 unsigned err; 394 unsigned char *d; 395 396 retry: 397 err = submit_vpd_inquiry(sdev, h); 398 399 if (err != SCSI_DH_OK) 400 return err; 401 402 /* Check if vpd page exceeds initial buffer */ 403 len = (h->buff[2] << 8) + h->buff[3] + 4; 404 if (len > h->bufflen) { 405 /* Resubmit with the correct length */ 406 if (realloc_buffer(h, len)) { 407 sdev_printk(KERN_WARNING, sdev, 408 "%s: kmalloc buffer failed\n", 409 ALUA_DH_NAME); 410 /* Temporary failure, bypass */ 411 return SCSI_DH_DEV_TEMP_BUSY; 412 } 413 goto retry; 414 } 415 416 /* 417 * Now look for the correct descriptor. 418 */ 419 d = h->buff + 4; 420 while (d < h->buff + len) { 421 switch (d[1] & 0xf) { 422 case 0x4: 423 /* Relative target port */ 424 h->rel_port = (d[6] << 8) + d[7]; 425 break; 426 case 0x5: 427 /* Target port group */ 428 h->group_id = (d[6] << 8) + d[7]; 429 break; 430 default: 431 break; 432 } 433 d += d[3] + 4; 434 } 435 436 if (h->group_id == -1) { 437 /* 438 * Internal error; TPGS supported but required 439 * VPD identification descriptors not present. 440 * Disable ALUA support 441 */ 442 sdev_printk(KERN_INFO, sdev, 443 "%s: No target port descriptors found\n", 444 ALUA_DH_NAME); 445 h->state = TPGS_STATE_OPTIMIZED; 446 h->tpgs = TPGS_MODE_NONE; 447 err = SCSI_DH_DEV_UNSUPP; 448 } else { 449 sdev_printk(KERN_INFO, sdev, 450 "%s: port group %02x rel port %02x\n", 451 ALUA_DH_NAME, h->group_id, h->rel_port); 452 } 453 454 return err; 455 } 456 457 static char print_alua_state(int state) 458 { 459 switch (state) { 460 case TPGS_STATE_OPTIMIZED: 461 return 'A'; 462 case TPGS_STATE_NONOPTIMIZED: 463 return 'N'; 464 case TPGS_STATE_STANDBY: 465 return 'S'; 466 case TPGS_STATE_UNAVAILABLE: 467 return 'U'; 468 case TPGS_STATE_LBA_DEPENDENT: 469 return 'L'; 470 case TPGS_STATE_OFFLINE: 471 return 'O'; 472 case TPGS_STATE_TRANSITIONING: 473 return 'T'; 474 default: 475 return 'X'; 476 } 477 } 478 479 static int alua_check_sense(struct scsi_device *sdev, 480 struct scsi_sense_hdr *sense_hdr) 481 { 482 switch (sense_hdr->sense_key) { 483 case NOT_READY: 484 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0a) 485 /* 486 * LUN Not Accessible - ALUA state transition 487 */ 488 return ADD_TO_MLQUEUE; 489 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0b) 490 /* 491 * LUN Not Accessible -- Target port in standby state 492 */ 493 return SUCCESS; 494 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0c) 495 /* 496 * LUN Not Accessible -- Target port in unavailable state 497 */ 498 return SUCCESS; 499 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x12) 500 /* 501 * LUN Not Ready -- Offline 502 */ 503 return SUCCESS; 504 break; 505 case UNIT_ATTENTION: 506 if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00) 507 /* 508 * Power On, Reset, or Bus Device Reset, just retry. 509 */ 510 return ADD_TO_MLQUEUE; 511 if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x06) { 512 /* 513 * ALUA state changed 514 */ 515 return ADD_TO_MLQUEUE; 516 } 517 if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x07) { 518 /* 519 * Implicit ALUA state transition failed 520 */ 521 return ADD_TO_MLQUEUE; 522 } 523 if (sense_hdr->asc == 0x3f && sense_hdr->ascq == 0x0e) { 524 /* 525 * REPORTED_LUNS_DATA_HAS_CHANGED is reported 526 * when switching controllers on targets like 527 * Intel Multi-Flex. We can just retry. 528 */ 529 return ADD_TO_MLQUEUE; 530 } 531 532 break; 533 } 534 535 return SCSI_RETURN_NOT_HANDLED; 536 } 537 538 /* 539 * alua_rtpg - Evaluate REPORT TARGET GROUP STATES 540 * @sdev: the device to be evaluated. 541 * 542 * Evaluate the Target Port Group State. 543 * Returns SCSI_DH_DEV_OFFLINED if the path is 544 * found to be unuseable. 545 */ 546 static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h) 547 { 548 struct scsi_sense_hdr sense_hdr; 549 int len, k, off, valid_states = 0; 550 char *ucp; 551 unsigned err; 552 unsigned long expiry, interval = 10; 553 554 expiry = round_jiffies_up(jiffies + ALUA_FAILOVER_TIMEOUT); 555 retry: 556 err = submit_rtpg(sdev, h); 557 558 if (err == SCSI_DH_IO && h->senselen > 0) { 559 err = scsi_normalize_sense(h->sense, SCSI_SENSE_BUFFERSIZE, 560 &sense_hdr); 561 if (!err) 562 return SCSI_DH_IO; 563 564 err = alua_check_sense(sdev, &sense_hdr); 565 if (err == ADD_TO_MLQUEUE && time_before(jiffies, expiry)) 566 goto retry; 567 sdev_printk(KERN_INFO, sdev, 568 "%s: rtpg sense code %02x/%02x/%02x\n", 569 ALUA_DH_NAME, sense_hdr.sense_key, 570 sense_hdr.asc, sense_hdr.ascq); 571 err = SCSI_DH_IO; 572 } 573 if (err != SCSI_DH_OK) 574 return err; 575 576 len = (h->buff[0] << 24) + (h->buff[1] << 16) + 577 (h->buff[2] << 8) + h->buff[3] + 4; 578 579 if (len > h->bufflen) { 580 /* Resubmit with the correct length */ 581 if (realloc_buffer(h, len)) { 582 sdev_printk(KERN_WARNING, sdev, 583 "%s: kmalloc buffer failed\n",__func__); 584 /* Temporary failure, bypass */ 585 return SCSI_DH_DEV_TEMP_BUSY; 586 } 587 goto retry; 588 } 589 590 for (k = 4, ucp = h->buff + 4; k < len; k += off, ucp += off) { 591 if (h->group_id == (ucp[2] << 8) + ucp[3]) { 592 h->state = ucp[0] & 0x0f; 593 valid_states = ucp[1]; 594 } 595 off = 8 + (ucp[7] * 4); 596 } 597 598 sdev_printk(KERN_INFO, sdev, 599 "%s: port group %02x state %c supports %c%c%c%c%c%c%c\n", 600 ALUA_DH_NAME, h->group_id, print_alua_state(h->state), 601 valid_states&TPGS_SUPPORT_TRANSITION?'T':'t', 602 valid_states&TPGS_SUPPORT_OFFLINE?'O':'o', 603 valid_states&TPGS_SUPPORT_LBA_DEPENDENT?'L':'l', 604 valid_states&TPGS_SUPPORT_UNAVAILABLE?'U':'u', 605 valid_states&TPGS_SUPPORT_STANDBY?'S':'s', 606 valid_states&TPGS_SUPPORT_NONOPTIMIZED?'N':'n', 607 valid_states&TPGS_SUPPORT_OPTIMIZED?'A':'a'); 608 609 switch (h->state) { 610 case TPGS_STATE_TRANSITIONING: 611 if (time_before(jiffies, expiry)) { 612 /* State transition, retry */ 613 interval *= 10; 614 msleep(interval); 615 goto retry; 616 } 617 /* Transitioning time exceeded, set port to standby */ 618 err = SCSI_DH_RETRY; 619 h->state = TPGS_STATE_STANDBY; 620 break; 621 case TPGS_STATE_OFFLINE: 622 case TPGS_STATE_UNAVAILABLE: 623 /* Path unuseable for unavailable/offline */ 624 err = SCSI_DH_DEV_OFFLINED; 625 break; 626 default: 627 /* Useable path if active */ 628 err = SCSI_DH_OK; 629 break; 630 } 631 return err; 632 } 633 634 /* 635 * alua_initialize - Initialize ALUA state 636 * @sdev: the device to be initialized 637 * 638 * For the prep_fn to work correctly we have 639 * to initialize the ALUA state for the device. 640 */ 641 static int alua_initialize(struct scsi_device *sdev, struct alua_dh_data *h) 642 { 643 int err; 644 645 err = alua_std_inquiry(sdev, h); 646 if (err != SCSI_DH_OK) 647 goto out; 648 649 err = alua_vpd_inquiry(sdev, h); 650 if (err != SCSI_DH_OK) 651 goto out; 652 653 err = alua_rtpg(sdev, h); 654 if (err != SCSI_DH_OK) 655 goto out; 656 657 out: 658 return err; 659 } 660 661 /* 662 * alua_activate - activate a path 663 * @sdev: device on the path to be activated 664 * 665 * We're currently switching the port group to be activated only and 666 * let the array figure out the rest. 667 * There may be other arrays which require us to switch all port groups 668 * based on a certain policy. But until we actually encounter them it 669 * should be okay. 670 */ 671 static int alua_activate(struct scsi_device *sdev, 672 activate_complete fn, void *data) 673 { 674 struct alua_dh_data *h = get_alua_data(sdev); 675 int err = SCSI_DH_OK; 676 677 if (h->group_id != -1) { 678 err = alua_rtpg(sdev, h); 679 if (err != SCSI_DH_OK) 680 goto out; 681 } 682 683 if (h->tpgs & TPGS_MODE_EXPLICIT && 684 h->state != TPGS_STATE_OPTIMIZED && 685 h->state != TPGS_STATE_LBA_DEPENDENT) { 686 h->callback_fn = fn; 687 h->callback_data = data; 688 err = submit_stpg(h); 689 if (err == SCSI_DH_OK) 690 return 0; 691 h->callback_fn = h->callback_data = NULL; 692 } 693 694 out: 695 if (fn) 696 fn(data, err); 697 return 0; 698 } 699 700 /* 701 * alua_prep_fn - request callback 702 * 703 * Fail I/O to all paths not in state 704 * active/optimized or active/non-optimized. 705 */ 706 static int alua_prep_fn(struct scsi_device *sdev, struct request *req) 707 { 708 struct alua_dh_data *h = get_alua_data(sdev); 709 int ret = BLKPREP_OK; 710 711 if (h->state == TPGS_STATE_TRANSITIONING) 712 ret = BLKPREP_DEFER; 713 else if (h->state != TPGS_STATE_OPTIMIZED && 714 h->state != TPGS_STATE_NONOPTIMIZED && 715 h->state != TPGS_STATE_LBA_DEPENDENT) { 716 ret = BLKPREP_KILL; 717 req->cmd_flags |= REQ_QUIET; 718 } 719 return ret; 720 721 } 722 723 static const struct scsi_dh_devlist alua_dev_list[] = { 724 {"HP", "MSA VOLUME" }, 725 {"HP", "HSV101" }, 726 {"HP", "HSV111" }, 727 {"HP", "HSV200" }, 728 {"HP", "HSV210" }, 729 {"HP", "HSV300" }, 730 {"IBM", "2107900" }, 731 {"IBM", "2145" }, 732 {"Pillar", "Axiom" }, 733 {"Intel", "Multi-Flex"}, 734 {"NETAPP", "LUN"}, 735 {"NETAPP", "LUN C-Mode"}, 736 {"AIX", "NVDISK"}, 737 {"Promise", "VTrak"}, 738 {NULL, NULL} 739 }; 740 741 static int alua_bus_attach(struct scsi_device *sdev); 742 static void alua_bus_detach(struct scsi_device *sdev); 743 744 static struct scsi_device_handler alua_dh = { 745 .name = ALUA_DH_NAME, 746 .module = THIS_MODULE, 747 .devlist = alua_dev_list, 748 .attach = alua_bus_attach, 749 .detach = alua_bus_detach, 750 .prep_fn = alua_prep_fn, 751 .check_sense = alua_check_sense, 752 .activate = alua_activate, 753 }; 754 755 /* 756 * alua_bus_attach - Attach device handler 757 * @sdev: device to be attached to 758 */ 759 static int alua_bus_attach(struct scsi_device *sdev) 760 { 761 struct scsi_dh_data *scsi_dh_data; 762 struct alua_dh_data *h; 763 unsigned long flags; 764 int err = SCSI_DH_OK; 765 766 scsi_dh_data = kzalloc(sizeof(*scsi_dh_data) 767 + sizeof(*h) , GFP_KERNEL); 768 if (!scsi_dh_data) { 769 sdev_printk(KERN_ERR, sdev, "%s: Attach failed\n", 770 ALUA_DH_NAME); 771 return -ENOMEM; 772 } 773 774 scsi_dh_data->scsi_dh = &alua_dh; 775 h = (struct alua_dh_data *) scsi_dh_data->buf; 776 h->tpgs = TPGS_MODE_UNINITIALIZED; 777 h->state = TPGS_STATE_OPTIMIZED; 778 h->group_id = -1; 779 h->rel_port = -1; 780 h->buff = h->inq; 781 h->bufflen = ALUA_INQUIRY_SIZE; 782 h->sdev = sdev; 783 784 err = alua_initialize(sdev, h); 785 if (err != SCSI_DH_OK) 786 goto failed; 787 788 if (!try_module_get(THIS_MODULE)) 789 goto failed; 790 791 spin_lock_irqsave(sdev->request_queue->queue_lock, flags); 792 sdev->scsi_dh_data = scsi_dh_data; 793 spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags); 794 795 return 0; 796 797 failed: 798 kfree(scsi_dh_data); 799 sdev_printk(KERN_ERR, sdev, "%s: not attached\n", ALUA_DH_NAME); 800 return -EINVAL; 801 } 802 803 /* 804 * alua_bus_detach - Detach device handler 805 * @sdev: device to be detached from 806 */ 807 static void alua_bus_detach(struct scsi_device *sdev) 808 { 809 struct scsi_dh_data *scsi_dh_data; 810 struct alua_dh_data *h; 811 unsigned long flags; 812 813 spin_lock_irqsave(sdev->request_queue->queue_lock, flags); 814 scsi_dh_data = sdev->scsi_dh_data; 815 sdev->scsi_dh_data = NULL; 816 spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags); 817 818 h = (struct alua_dh_data *) scsi_dh_data->buf; 819 if (h->buff && h->inq != h->buff) 820 kfree(h->buff); 821 kfree(scsi_dh_data); 822 module_put(THIS_MODULE); 823 sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", ALUA_DH_NAME); 824 } 825 826 static int __init alua_init(void) 827 { 828 int r; 829 830 r = scsi_register_device_handler(&alua_dh); 831 if (r != 0) 832 printk(KERN_ERR "%s: Failed to register scsi device handler", 833 ALUA_DH_NAME); 834 return r; 835 } 836 837 static void __exit alua_exit(void) 838 { 839 scsi_unregister_device_handler(&alua_dh); 840 } 841 842 module_init(alua_init); 843 module_exit(alua_exit); 844 845 MODULE_DESCRIPTION("DM Multipath ALUA support"); 846 MODULE_AUTHOR("Hannes Reinecke <hare@suse.de>"); 847 MODULE_LICENSE("GPL"); 848 MODULE_VERSION(ALUA_DH_VER); 849