1 /* 2 * Copyright (C) 2013 Shaohua Li <shli@kernel.org> 3 * Copyright (C) 2014 Red Hat, Inc. 4 * Copyright (C) 2015 Arrikto, Inc. 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms and conditions of the GNU General Public License, 8 * version 2, as published by the Free Software Foundation. 9 * 10 * This program is distributed in the hope it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 13 * more details. 14 * 15 * You should have received a copy of the GNU General Public License along with 16 * this program; if not, write to the Free Software Foundation, Inc., 17 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. 18 */ 19 20 #include <linux/spinlock.h> 21 #include <linux/module.h> 22 #include <linux/idr.h> 23 #include <linux/kernel.h> 24 #include <linux/timer.h> 25 #include <linux/parser.h> 26 #include <linux/vmalloc.h> 27 #include <linux/uio_driver.h> 28 #include <linux/stringify.h> 29 #include <linux/bitops.h> 30 #include <linux/highmem.h> 31 #include <linux/configfs.h> 32 #include <net/genetlink.h> 33 #include <scsi/scsi_common.h> 34 #include <scsi/scsi_proto.h> 35 #include <target/target_core_base.h> 36 #include <target/target_core_fabric.h> 37 #include <target/target_core_backend.h> 38 39 #include <linux/target_core_user.h> 40 41 /* 42 * Define a shared-memory interface for LIO to pass SCSI commands and 43 * data to userspace for processing. This is to allow backends that 44 * are too complex for in-kernel support to be possible. 45 * 46 * It uses the UIO framework to do a lot of the device-creation and 47 * introspection work for us. 48 * 49 * See the .h file for how the ring is laid out. Note that while the 50 * command ring is defined, the particulars of the data area are 51 * not. Offset values in the command entry point to other locations 52 * internal to the mmap()ed area. There is separate space outside the 53 * command ring for data buffers. This leaves maximum flexibility for 54 * moving buffer allocations, or even page flipping or other 55 * allocation techniques, without altering the command ring layout. 56 * 57 * SECURITY: 58 * The user process must be assumed to be malicious. There's no way to 59 * prevent it breaking the command ring protocol if it wants, but in 60 * order to prevent other issues we must only ever read *data* from 61 * the shared memory area, not offsets or sizes. This applies to 62 * command ring entries as well as the mailbox. Extra code needed for 63 * this may have a 'UAM' comment. 64 */ 65 66 67 #define TCMU_TIME_OUT (30 * MSEC_PER_SEC) 68 69 #define DATA_BLOCK_BITS 256 70 #define DATA_BLOCK_SIZE 4096 71 72 #define CMDR_SIZE (16 * 4096) 73 #define DATA_SIZE (DATA_BLOCK_BITS * DATA_BLOCK_SIZE) 74 75 #define TCMU_RING_SIZE (CMDR_SIZE + DATA_SIZE) 76 77 static struct device *tcmu_root_device; 78 79 struct tcmu_hba { 80 u32 host_id; 81 }; 82 83 #define TCMU_CONFIG_LEN 256 84 85 struct tcmu_dev { 86 struct se_device se_dev; 87 88 char *name; 89 struct se_hba *hba; 90 91 #define TCMU_DEV_BIT_OPEN 0 92 #define TCMU_DEV_BIT_BROKEN 1 93 unsigned long flags; 94 95 struct uio_info uio_info; 96 97 struct tcmu_mailbox *mb_addr; 98 size_t dev_size; 99 u32 cmdr_size; 100 u32 cmdr_last_cleaned; 101 /* Offset of data area from start of mb */ 102 /* Must add data_off and mb_addr to get the address */ 103 size_t data_off; 104 size_t data_size; 105 106 DECLARE_BITMAP(data_bitmap, DATA_BLOCK_BITS); 107 108 wait_queue_head_t wait_cmdr; 109 /* TODO should this be a mutex? */ 110 spinlock_t cmdr_lock; 111 112 struct idr commands; 113 spinlock_t commands_lock; 114 115 struct timer_list timeout; 116 unsigned int cmd_time_out; 117 118 char dev_config[TCMU_CONFIG_LEN]; 119 }; 120 121 #define TCMU_DEV(_se_dev) container_of(_se_dev, struct tcmu_dev, se_dev) 122 123 #define CMDR_OFF sizeof(struct tcmu_mailbox) 124 125 struct tcmu_cmd { 126 struct se_cmd *se_cmd; 127 struct tcmu_dev *tcmu_dev; 128 129 uint16_t cmd_id; 130 131 /* Can't use se_cmd when cleaning up expired cmds, because if 132 cmd has been completed then accessing se_cmd is off limits */ 133 DECLARE_BITMAP(data_bitmap, DATA_BLOCK_BITS); 134 135 unsigned long deadline; 136 137 #define TCMU_CMD_BIT_EXPIRED 0 138 unsigned long flags; 139 }; 140 141 static struct kmem_cache *tcmu_cmd_cache; 142 143 /* multicast group */ 144 enum tcmu_multicast_groups { 145 TCMU_MCGRP_CONFIG, 146 }; 147 148 static const struct genl_multicast_group tcmu_mcgrps[] = { 149 [TCMU_MCGRP_CONFIG] = { .name = "config", }, 150 }; 151 152 /* Our generic netlink family */ 153 static struct genl_family tcmu_genl_family __ro_after_init = { 154 .module = THIS_MODULE, 155 .hdrsize = 0, 156 .name = "TCM-USER", 157 .version = 1, 158 .maxattr = TCMU_ATTR_MAX, 159 .mcgrps = tcmu_mcgrps, 160 .n_mcgrps = ARRAY_SIZE(tcmu_mcgrps), 161 .netnsok = true, 162 }; 163 164 static struct tcmu_cmd *tcmu_alloc_cmd(struct se_cmd *se_cmd) 165 { 166 struct se_device *se_dev = se_cmd->se_dev; 167 struct tcmu_dev *udev = TCMU_DEV(se_dev); 168 struct tcmu_cmd *tcmu_cmd; 169 int cmd_id; 170 171 tcmu_cmd = kmem_cache_zalloc(tcmu_cmd_cache, GFP_KERNEL); 172 if (!tcmu_cmd) 173 return NULL; 174 175 tcmu_cmd->se_cmd = se_cmd; 176 tcmu_cmd->tcmu_dev = udev; 177 if (udev->cmd_time_out) 178 tcmu_cmd->deadline = jiffies + 179 msecs_to_jiffies(udev->cmd_time_out); 180 181 idr_preload(GFP_KERNEL); 182 spin_lock_irq(&udev->commands_lock); 183 cmd_id = idr_alloc(&udev->commands, tcmu_cmd, 0, 184 USHRT_MAX, GFP_NOWAIT); 185 spin_unlock_irq(&udev->commands_lock); 186 idr_preload_end(); 187 188 if (cmd_id < 0) { 189 kmem_cache_free(tcmu_cmd_cache, tcmu_cmd); 190 return NULL; 191 } 192 tcmu_cmd->cmd_id = cmd_id; 193 194 return tcmu_cmd; 195 } 196 197 static inline void tcmu_flush_dcache_range(void *vaddr, size_t size) 198 { 199 unsigned long offset = offset_in_page(vaddr); 200 201 size = round_up(size+offset, PAGE_SIZE); 202 vaddr -= offset; 203 204 while (size) { 205 flush_dcache_page(virt_to_page(vaddr)); 206 size -= PAGE_SIZE; 207 } 208 } 209 210 /* 211 * Some ring helper functions. We don't assume size is a power of 2 so 212 * we can't use circ_buf.h. 213 */ 214 static inline size_t spc_used(size_t head, size_t tail, size_t size) 215 { 216 int diff = head - tail; 217 218 if (diff >= 0) 219 return diff; 220 else 221 return size + diff; 222 } 223 224 static inline size_t spc_free(size_t head, size_t tail, size_t size) 225 { 226 /* Keep 1 byte unused or we can't tell full from empty */ 227 return (size - spc_used(head, tail, size) - 1); 228 } 229 230 static inline size_t head_to_end(size_t head, size_t size) 231 { 232 return size - head; 233 } 234 235 static inline void new_iov(struct iovec **iov, int *iov_cnt, 236 struct tcmu_dev *udev) 237 { 238 struct iovec *iovec; 239 240 if (*iov_cnt != 0) 241 (*iov)++; 242 (*iov_cnt)++; 243 244 iovec = *iov; 245 memset(iovec, 0, sizeof(struct iovec)); 246 } 247 248 #define UPDATE_HEAD(head, used, size) smp_store_release(&head, ((head % size) + used) % size) 249 250 /* offset is relative to mb_addr */ 251 static inline size_t get_block_offset(struct tcmu_dev *dev, 252 int block, int remaining) 253 { 254 return dev->data_off + block * DATA_BLOCK_SIZE + 255 DATA_BLOCK_SIZE - remaining; 256 } 257 258 static inline size_t iov_tail(struct tcmu_dev *udev, struct iovec *iov) 259 { 260 return (size_t)iov->iov_base + iov->iov_len; 261 } 262 263 static void alloc_and_scatter_data_area(struct tcmu_dev *udev, 264 struct scatterlist *data_sg, unsigned int data_nents, 265 struct iovec **iov, int *iov_cnt, bool copy_data) 266 { 267 int i, block; 268 int block_remaining = 0; 269 void *from, *to; 270 size_t copy_bytes, to_offset; 271 struct scatterlist *sg; 272 273 for_each_sg(data_sg, sg, data_nents, i) { 274 int sg_remaining = sg->length; 275 from = kmap_atomic(sg_page(sg)) + sg->offset; 276 while (sg_remaining > 0) { 277 if (block_remaining == 0) { 278 block = find_first_zero_bit(udev->data_bitmap, 279 DATA_BLOCK_BITS); 280 block_remaining = DATA_BLOCK_SIZE; 281 set_bit(block, udev->data_bitmap); 282 } 283 copy_bytes = min_t(size_t, sg_remaining, 284 block_remaining); 285 to_offset = get_block_offset(udev, block, 286 block_remaining); 287 to = (void *)udev->mb_addr + to_offset; 288 if (*iov_cnt != 0 && 289 to_offset == iov_tail(udev, *iov)) { 290 (*iov)->iov_len += copy_bytes; 291 } else { 292 new_iov(iov, iov_cnt, udev); 293 (*iov)->iov_base = (void __user *) to_offset; 294 (*iov)->iov_len = copy_bytes; 295 } 296 if (copy_data) { 297 memcpy(to, from + sg->length - sg_remaining, 298 copy_bytes); 299 tcmu_flush_dcache_range(to, copy_bytes); 300 } 301 sg_remaining -= copy_bytes; 302 block_remaining -= copy_bytes; 303 } 304 kunmap_atomic(from - sg->offset); 305 } 306 } 307 308 static void free_data_area(struct tcmu_dev *udev, struct tcmu_cmd *cmd) 309 { 310 bitmap_xor(udev->data_bitmap, udev->data_bitmap, cmd->data_bitmap, 311 DATA_BLOCK_BITS); 312 } 313 314 static void gather_data_area(struct tcmu_dev *udev, struct tcmu_cmd *cmd, 315 bool bidi) 316 { 317 struct se_cmd *se_cmd = cmd->se_cmd; 318 int i, block; 319 int block_remaining = 0; 320 void *from, *to; 321 size_t copy_bytes, from_offset; 322 struct scatterlist *sg, *data_sg; 323 unsigned int data_nents; 324 DECLARE_BITMAP(bitmap, DATA_BLOCK_BITS); 325 326 bitmap_copy(bitmap, cmd->data_bitmap, DATA_BLOCK_BITS); 327 328 if (!bidi) { 329 data_sg = se_cmd->t_data_sg; 330 data_nents = se_cmd->t_data_nents; 331 } else { 332 uint32_t count; 333 334 /* 335 * For bidi case, the first count blocks are for Data-Out 336 * buffer blocks, and before gathering the Data-In buffer 337 * the Data-Out buffer blocks should be discarded. 338 */ 339 count = DIV_ROUND_UP(se_cmd->data_length, DATA_BLOCK_SIZE); 340 while (count--) { 341 block = find_first_bit(bitmap, DATA_BLOCK_BITS); 342 clear_bit(block, bitmap); 343 } 344 345 data_sg = se_cmd->t_bidi_data_sg; 346 data_nents = se_cmd->t_bidi_data_nents; 347 } 348 349 for_each_sg(data_sg, sg, data_nents, i) { 350 int sg_remaining = sg->length; 351 to = kmap_atomic(sg_page(sg)) + sg->offset; 352 while (sg_remaining > 0) { 353 if (block_remaining == 0) { 354 block = find_first_bit(bitmap, 355 DATA_BLOCK_BITS); 356 block_remaining = DATA_BLOCK_SIZE; 357 clear_bit(block, bitmap); 358 } 359 copy_bytes = min_t(size_t, sg_remaining, 360 block_remaining); 361 from_offset = get_block_offset(udev, block, 362 block_remaining); 363 from = (void *) udev->mb_addr + from_offset; 364 tcmu_flush_dcache_range(from, copy_bytes); 365 memcpy(to + sg->length - sg_remaining, from, 366 copy_bytes); 367 368 sg_remaining -= copy_bytes; 369 block_remaining -= copy_bytes; 370 } 371 kunmap_atomic(to - sg->offset); 372 } 373 } 374 375 static inline size_t spc_bitmap_free(unsigned long *bitmap) 376 { 377 return DATA_BLOCK_SIZE * (DATA_BLOCK_BITS - 378 bitmap_weight(bitmap, DATA_BLOCK_BITS)); 379 } 380 381 /* 382 * We can't queue a command until we have space available on the cmd ring *and* 383 * space available on the data area. 384 * 385 * Called with ring lock held. 386 */ 387 static bool is_ring_space_avail(struct tcmu_dev *udev, size_t cmd_size, size_t data_needed) 388 { 389 struct tcmu_mailbox *mb = udev->mb_addr; 390 size_t space, cmd_needed; 391 u32 cmd_head; 392 393 tcmu_flush_dcache_range(mb, sizeof(*mb)); 394 395 cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */ 396 397 /* 398 * If cmd end-of-ring space is too small then we need space for a NOP plus 399 * original cmd - cmds are internally contiguous. 400 */ 401 if (head_to_end(cmd_head, udev->cmdr_size) >= cmd_size) 402 cmd_needed = cmd_size; 403 else 404 cmd_needed = cmd_size + head_to_end(cmd_head, udev->cmdr_size); 405 406 space = spc_free(cmd_head, udev->cmdr_last_cleaned, udev->cmdr_size); 407 if (space < cmd_needed) { 408 pr_debug("no cmd space: %u %u %u\n", cmd_head, 409 udev->cmdr_last_cleaned, udev->cmdr_size); 410 return false; 411 } 412 413 space = spc_bitmap_free(udev->data_bitmap); 414 if (space < data_needed) { 415 pr_debug("no data space: only %zu available, but ask for %zu\n", 416 space, data_needed); 417 return false; 418 } 419 420 return true; 421 } 422 423 static inline size_t tcmu_cmd_get_data_length(struct tcmu_cmd *tcmu_cmd) 424 { 425 struct se_cmd *se_cmd = tcmu_cmd->se_cmd; 426 size_t data_length = round_up(se_cmd->data_length, DATA_BLOCK_SIZE); 427 428 if (se_cmd->se_cmd_flags & SCF_BIDI) { 429 BUG_ON(!(se_cmd->t_bidi_data_sg && se_cmd->t_bidi_data_nents)); 430 data_length += round_up(se_cmd->t_bidi_data_sg->length, 431 DATA_BLOCK_SIZE); 432 } 433 434 return data_length; 435 } 436 437 static inline uint32_t tcmu_cmd_get_block_cnt(struct tcmu_cmd *tcmu_cmd) 438 { 439 size_t data_length = tcmu_cmd_get_data_length(tcmu_cmd); 440 441 return data_length / DATA_BLOCK_SIZE; 442 } 443 444 static sense_reason_t 445 tcmu_queue_cmd_ring(struct tcmu_cmd *tcmu_cmd) 446 { 447 struct tcmu_dev *udev = tcmu_cmd->tcmu_dev; 448 struct se_cmd *se_cmd = tcmu_cmd->se_cmd; 449 size_t base_command_size, command_size; 450 struct tcmu_mailbox *mb; 451 struct tcmu_cmd_entry *entry; 452 struct iovec *iov; 453 int iov_cnt; 454 uint32_t cmd_head; 455 uint64_t cdb_off; 456 bool copy_to_data_area; 457 size_t data_length = tcmu_cmd_get_data_length(tcmu_cmd); 458 DECLARE_BITMAP(old_bitmap, DATA_BLOCK_BITS); 459 460 if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) 461 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 462 463 /* 464 * Must be a certain minimum size for response sense info, but 465 * also may be larger if the iov array is large. 466 * 467 * We prepare way too many iovs for potential uses here, because it's 468 * expensive to tell how many regions are freed in the bitmap 469 */ 470 base_command_size = max(offsetof(struct tcmu_cmd_entry, 471 req.iov[tcmu_cmd_get_block_cnt(tcmu_cmd)]), 472 sizeof(struct tcmu_cmd_entry)); 473 command_size = base_command_size 474 + round_up(scsi_command_size(se_cmd->t_task_cdb), TCMU_OP_ALIGN_SIZE); 475 476 WARN_ON(command_size & (TCMU_OP_ALIGN_SIZE-1)); 477 478 spin_lock_irq(&udev->cmdr_lock); 479 480 mb = udev->mb_addr; 481 cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */ 482 if ((command_size > (udev->cmdr_size / 2)) || 483 data_length > udev->data_size) { 484 pr_warn("TCMU: Request of size %zu/%zu is too big for %u/%zu " 485 "cmd ring/data area\n", command_size, data_length, 486 udev->cmdr_size, udev->data_size); 487 spin_unlock_irq(&udev->cmdr_lock); 488 return TCM_INVALID_CDB_FIELD; 489 } 490 491 while (!is_ring_space_avail(udev, command_size, data_length)) { 492 int ret; 493 DEFINE_WAIT(__wait); 494 495 prepare_to_wait(&udev->wait_cmdr, &__wait, TASK_INTERRUPTIBLE); 496 497 pr_debug("sleeping for ring space\n"); 498 spin_unlock_irq(&udev->cmdr_lock); 499 if (udev->cmd_time_out) 500 ret = schedule_timeout( 501 msecs_to_jiffies(udev->cmd_time_out)); 502 else 503 ret = schedule_timeout(msecs_to_jiffies(TCMU_TIME_OUT)); 504 finish_wait(&udev->wait_cmdr, &__wait); 505 if (!ret) { 506 pr_warn("tcmu: command timed out\n"); 507 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 508 } 509 510 spin_lock_irq(&udev->cmdr_lock); 511 512 /* We dropped cmdr_lock, cmd_head is stale */ 513 cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */ 514 } 515 516 /* Insert a PAD if end-of-ring space is too small */ 517 if (head_to_end(cmd_head, udev->cmdr_size) < command_size) { 518 size_t pad_size = head_to_end(cmd_head, udev->cmdr_size); 519 520 entry = (void *) mb + CMDR_OFF + cmd_head; 521 tcmu_flush_dcache_range(entry, sizeof(*entry)); 522 tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_PAD); 523 tcmu_hdr_set_len(&entry->hdr.len_op, pad_size); 524 entry->hdr.cmd_id = 0; /* not used for PAD */ 525 entry->hdr.kflags = 0; 526 entry->hdr.uflags = 0; 527 528 UPDATE_HEAD(mb->cmd_head, pad_size, udev->cmdr_size); 529 530 cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */ 531 WARN_ON(cmd_head != 0); 532 } 533 534 entry = (void *) mb + CMDR_OFF + cmd_head; 535 tcmu_flush_dcache_range(entry, sizeof(*entry)); 536 tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_CMD); 537 tcmu_hdr_set_len(&entry->hdr.len_op, command_size); 538 entry->hdr.cmd_id = tcmu_cmd->cmd_id; 539 entry->hdr.kflags = 0; 540 entry->hdr.uflags = 0; 541 542 bitmap_copy(old_bitmap, udev->data_bitmap, DATA_BLOCK_BITS); 543 544 /* Handle allocating space from the data area */ 545 iov = &entry->req.iov[0]; 546 iov_cnt = 0; 547 copy_to_data_area = (se_cmd->data_direction == DMA_TO_DEVICE 548 || se_cmd->se_cmd_flags & SCF_BIDI); 549 alloc_and_scatter_data_area(udev, se_cmd->t_data_sg, 550 se_cmd->t_data_nents, &iov, &iov_cnt, copy_to_data_area); 551 entry->req.iov_cnt = iov_cnt; 552 entry->req.iov_dif_cnt = 0; 553 554 /* Handle BIDI commands */ 555 if (se_cmd->se_cmd_flags & SCF_BIDI) { 556 iov_cnt = 0; 557 iov++; 558 alloc_and_scatter_data_area(udev, se_cmd->t_bidi_data_sg, 559 se_cmd->t_bidi_data_nents, &iov, &iov_cnt, 560 false); 561 entry->req.iov_bidi_cnt = iov_cnt; 562 } 563 /* cmd's data_bitmap is what changed in process */ 564 bitmap_xor(tcmu_cmd->data_bitmap, old_bitmap, udev->data_bitmap, 565 DATA_BLOCK_BITS); 566 567 /* All offsets relative to mb_addr, not start of entry! */ 568 cdb_off = CMDR_OFF + cmd_head + base_command_size; 569 memcpy((void *) mb + cdb_off, se_cmd->t_task_cdb, scsi_command_size(se_cmd->t_task_cdb)); 570 entry->req.cdb_off = cdb_off; 571 tcmu_flush_dcache_range(entry, sizeof(*entry)); 572 573 UPDATE_HEAD(mb->cmd_head, command_size, udev->cmdr_size); 574 tcmu_flush_dcache_range(mb, sizeof(*mb)); 575 576 spin_unlock_irq(&udev->cmdr_lock); 577 578 /* TODO: only if FLUSH and FUA? */ 579 uio_event_notify(&udev->uio_info); 580 581 if (udev->cmd_time_out) 582 mod_timer(&udev->timeout, round_jiffies_up(jiffies + 583 msecs_to_jiffies(udev->cmd_time_out))); 584 585 return TCM_NO_SENSE; 586 } 587 588 static sense_reason_t 589 tcmu_queue_cmd(struct se_cmd *se_cmd) 590 { 591 struct se_device *se_dev = se_cmd->se_dev; 592 struct tcmu_dev *udev = TCMU_DEV(se_dev); 593 struct tcmu_cmd *tcmu_cmd; 594 sense_reason_t ret; 595 596 tcmu_cmd = tcmu_alloc_cmd(se_cmd); 597 if (!tcmu_cmd) 598 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 599 600 ret = tcmu_queue_cmd_ring(tcmu_cmd); 601 if (ret != TCM_NO_SENSE) { 602 pr_err("TCMU: Could not queue command\n"); 603 spin_lock_irq(&udev->commands_lock); 604 idr_remove(&udev->commands, tcmu_cmd->cmd_id); 605 spin_unlock_irq(&udev->commands_lock); 606 607 kmem_cache_free(tcmu_cmd_cache, tcmu_cmd); 608 } 609 610 return ret; 611 } 612 613 static void tcmu_handle_completion(struct tcmu_cmd *cmd, struct tcmu_cmd_entry *entry) 614 { 615 struct se_cmd *se_cmd = cmd->se_cmd; 616 struct tcmu_dev *udev = cmd->tcmu_dev; 617 618 if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) { 619 /* 620 * cmd has been completed already from timeout, just reclaim 621 * data area space and free cmd 622 */ 623 free_data_area(udev, cmd); 624 625 kmem_cache_free(tcmu_cmd_cache, cmd); 626 return; 627 } 628 629 if (entry->hdr.uflags & TCMU_UFLAG_UNKNOWN_OP) { 630 free_data_area(udev, cmd); 631 pr_warn("TCMU: Userspace set UNKNOWN_OP flag on se_cmd %p\n", 632 cmd->se_cmd); 633 entry->rsp.scsi_status = SAM_STAT_CHECK_CONDITION; 634 } else if (entry->rsp.scsi_status == SAM_STAT_CHECK_CONDITION) { 635 memcpy(se_cmd->sense_buffer, entry->rsp.sense_buffer, 636 se_cmd->scsi_sense_length); 637 free_data_area(udev, cmd); 638 } else if (se_cmd->se_cmd_flags & SCF_BIDI) { 639 /* Get Data-In buffer before clean up */ 640 gather_data_area(udev, cmd, true); 641 free_data_area(udev, cmd); 642 } else if (se_cmd->data_direction == DMA_FROM_DEVICE) { 643 gather_data_area(udev, cmd, false); 644 free_data_area(udev, cmd); 645 } else if (se_cmd->data_direction == DMA_TO_DEVICE) { 646 free_data_area(udev, cmd); 647 } else if (se_cmd->data_direction != DMA_NONE) { 648 pr_warn("TCMU: data direction was %d!\n", 649 se_cmd->data_direction); 650 } 651 652 target_complete_cmd(cmd->se_cmd, entry->rsp.scsi_status); 653 cmd->se_cmd = NULL; 654 655 kmem_cache_free(tcmu_cmd_cache, cmd); 656 } 657 658 static unsigned int tcmu_handle_completions(struct tcmu_dev *udev) 659 { 660 struct tcmu_mailbox *mb; 661 unsigned long flags; 662 int handled = 0; 663 664 if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) { 665 pr_err("ring broken, not handling completions\n"); 666 return 0; 667 } 668 669 spin_lock_irqsave(&udev->cmdr_lock, flags); 670 671 mb = udev->mb_addr; 672 tcmu_flush_dcache_range(mb, sizeof(*mb)); 673 674 while (udev->cmdr_last_cleaned != ACCESS_ONCE(mb->cmd_tail)) { 675 676 struct tcmu_cmd_entry *entry = (void *) mb + CMDR_OFF + udev->cmdr_last_cleaned; 677 struct tcmu_cmd *cmd; 678 679 tcmu_flush_dcache_range(entry, sizeof(*entry)); 680 681 if (tcmu_hdr_get_op(entry->hdr.len_op) == TCMU_OP_PAD) { 682 UPDATE_HEAD(udev->cmdr_last_cleaned, 683 tcmu_hdr_get_len(entry->hdr.len_op), 684 udev->cmdr_size); 685 continue; 686 } 687 WARN_ON(tcmu_hdr_get_op(entry->hdr.len_op) != TCMU_OP_CMD); 688 689 spin_lock(&udev->commands_lock); 690 cmd = idr_remove(&udev->commands, entry->hdr.cmd_id); 691 spin_unlock(&udev->commands_lock); 692 693 if (!cmd) { 694 pr_err("cmd_id not found, ring is broken\n"); 695 set_bit(TCMU_DEV_BIT_BROKEN, &udev->flags); 696 break; 697 } 698 699 tcmu_handle_completion(cmd, entry); 700 701 UPDATE_HEAD(udev->cmdr_last_cleaned, 702 tcmu_hdr_get_len(entry->hdr.len_op), 703 udev->cmdr_size); 704 705 handled++; 706 } 707 708 if (mb->cmd_tail == mb->cmd_head) 709 del_timer(&udev->timeout); /* no more pending cmds */ 710 711 spin_unlock_irqrestore(&udev->cmdr_lock, flags); 712 713 wake_up(&udev->wait_cmdr); 714 715 return handled; 716 } 717 718 static int tcmu_check_expired_cmd(int id, void *p, void *data) 719 { 720 struct tcmu_cmd *cmd = p; 721 722 if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) 723 return 0; 724 725 if (!time_after(jiffies, cmd->deadline)) 726 return 0; 727 728 set_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags); 729 target_complete_cmd(cmd->se_cmd, SAM_STAT_CHECK_CONDITION); 730 cmd->se_cmd = NULL; 731 732 return 0; 733 } 734 735 static void tcmu_device_timedout(unsigned long data) 736 { 737 struct tcmu_dev *udev = (struct tcmu_dev *)data; 738 unsigned long flags; 739 int handled; 740 741 handled = tcmu_handle_completions(udev); 742 743 pr_warn("%d completions handled from timeout\n", handled); 744 745 spin_lock_irqsave(&udev->commands_lock, flags); 746 idr_for_each(&udev->commands, tcmu_check_expired_cmd, NULL); 747 spin_unlock_irqrestore(&udev->commands_lock, flags); 748 749 /* 750 * We don't need to wakeup threads on wait_cmdr since they have their 751 * own timeout. 752 */ 753 } 754 755 static int tcmu_attach_hba(struct se_hba *hba, u32 host_id) 756 { 757 struct tcmu_hba *tcmu_hba; 758 759 tcmu_hba = kzalloc(sizeof(struct tcmu_hba), GFP_KERNEL); 760 if (!tcmu_hba) 761 return -ENOMEM; 762 763 tcmu_hba->host_id = host_id; 764 hba->hba_ptr = tcmu_hba; 765 766 return 0; 767 } 768 769 static void tcmu_detach_hba(struct se_hba *hba) 770 { 771 kfree(hba->hba_ptr); 772 hba->hba_ptr = NULL; 773 } 774 775 static struct se_device *tcmu_alloc_device(struct se_hba *hba, const char *name) 776 { 777 struct tcmu_dev *udev; 778 779 udev = kzalloc(sizeof(struct tcmu_dev), GFP_KERNEL); 780 if (!udev) 781 return NULL; 782 783 udev->name = kstrdup(name, GFP_KERNEL); 784 if (!udev->name) { 785 kfree(udev); 786 return NULL; 787 } 788 789 udev->hba = hba; 790 udev->cmd_time_out = TCMU_TIME_OUT; 791 792 init_waitqueue_head(&udev->wait_cmdr); 793 spin_lock_init(&udev->cmdr_lock); 794 795 idr_init(&udev->commands); 796 spin_lock_init(&udev->commands_lock); 797 798 setup_timer(&udev->timeout, tcmu_device_timedout, 799 (unsigned long)udev); 800 801 return &udev->se_dev; 802 } 803 804 static int tcmu_irqcontrol(struct uio_info *info, s32 irq_on) 805 { 806 struct tcmu_dev *tcmu_dev = container_of(info, struct tcmu_dev, uio_info); 807 808 tcmu_handle_completions(tcmu_dev); 809 810 return 0; 811 } 812 813 /* 814 * mmap code from uio.c. Copied here because we want to hook mmap() 815 * and this stuff must come along. 816 */ 817 static int tcmu_find_mem_index(struct vm_area_struct *vma) 818 { 819 struct tcmu_dev *udev = vma->vm_private_data; 820 struct uio_info *info = &udev->uio_info; 821 822 if (vma->vm_pgoff < MAX_UIO_MAPS) { 823 if (info->mem[vma->vm_pgoff].size == 0) 824 return -1; 825 return (int)vma->vm_pgoff; 826 } 827 return -1; 828 } 829 830 static int tcmu_vma_fault(struct vm_fault *vmf) 831 { 832 struct tcmu_dev *udev = vmf->vma->vm_private_data; 833 struct uio_info *info = &udev->uio_info; 834 struct page *page; 835 unsigned long offset; 836 void *addr; 837 838 int mi = tcmu_find_mem_index(vmf->vma); 839 if (mi < 0) 840 return VM_FAULT_SIGBUS; 841 842 /* 843 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE 844 * to use mem[N]. 845 */ 846 offset = (vmf->pgoff - mi) << PAGE_SHIFT; 847 848 addr = (void *)(unsigned long)info->mem[mi].addr + offset; 849 if (info->mem[mi].memtype == UIO_MEM_LOGICAL) 850 page = virt_to_page(addr); 851 else 852 page = vmalloc_to_page(addr); 853 get_page(page); 854 vmf->page = page; 855 return 0; 856 } 857 858 static const struct vm_operations_struct tcmu_vm_ops = { 859 .fault = tcmu_vma_fault, 860 }; 861 862 static int tcmu_mmap(struct uio_info *info, struct vm_area_struct *vma) 863 { 864 struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info); 865 866 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; 867 vma->vm_ops = &tcmu_vm_ops; 868 869 vma->vm_private_data = udev; 870 871 /* Ensure the mmap is exactly the right size */ 872 if (vma_pages(vma) != (TCMU_RING_SIZE >> PAGE_SHIFT)) 873 return -EINVAL; 874 875 return 0; 876 } 877 878 static int tcmu_open(struct uio_info *info, struct inode *inode) 879 { 880 struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info); 881 882 /* O_EXCL not supported for char devs, so fake it? */ 883 if (test_and_set_bit(TCMU_DEV_BIT_OPEN, &udev->flags)) 884 return -EBUSY; 885 886 pr_debug("open\n"); 887 888 return 0; 889 } 890 891 static int tcmu_release(struct uio_info *info, struct inode *inode) 892 { 893 struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info); 894 895 clear_bit(TCMU_DEV_BIT_OPEN, &udev->flags); 896 897 pr_debug("close\n"); 898 899 return 0; 900 } 901 902 static int tcmu_netlink_event(enum tcmu_genl_cmd cmd, const char *name, int minor) 903 { 904 struct sk_buff *skb; 905 void *msg_header; 906 int ret = -ENOMEM; 907 908 skb = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL); 909 if (!skb) 910 return ret; 911 912 msg_header = genlmsg_put(skb, 0, 0, &tcmu_genl_family, 0, cmd); 913 if (!msg_header) 914 goto free_skb; 915 916 ret = nla_put_string(skb, TCMU_ATTR_DEVICE, name); 917 if (ret < 0) 918 goto free_skb; 919 920 ret = nla_put_u32(skb, TCMU_ATTR_MINOR, minor); 921 if (ret < 0) 922 goto free_skb; 923 924 genlmsg_end(skb, msg_header); 925 926 ret = genlmsg_multicast_allns(&tcmu_genl_family, skb, 0, 927 TCMU_MCGRP_CONFIG, GFP_KERNEL); 928 929 /* We don't care if no one is listening */ 930 if (ret == -ESRCH) 931 ret = 0; 932 933 return ret; 934 free_skb: 935 nlmsg_free(skb); 936 return ret; 937 } 938 939 static int tcmu_configure_device(struct se_device *dev) 940 { 941 struct tcmu_dev *udev = TCMU_DEV(dev); 942 struct tcmu_hba *hba = udev->hba->hba_ptr; 943 struct uio_info *info; 944 struct tcmu_mailbox *mb; 945 size_t size; 946 size_t used; 947 int ret = 0; 948 char *str; 949 950 info = &udev->uio_info; 951 952 size = snprintf(NULL, 0, "tcm-user/%u/%s/%s", hba->host_id, udev->name, 953 udev->dev_config); 954 size += 1; /* for \0 */ 955 str = kmalloc(size, GFP_KERNEL); 956 if (!str) 957 return -ENOMEM; 958 959 used = snprintf(str, size, "tcm-user/%u/%s", hba->host_id, udev->name); 960 961 if (udev->dev_config[0]) 962 snprintf(str + used, size - used, "/%s", udev->dev_config); 963 964 info->name = str; 965 966 udev->mb_addr = vzalloc(TCMU_RING_SIZE); 967 if (!udev->mb_addr) { 968 ret = -ENOMEM; 969 goto err_vzalloc; 970 } 971 972 /* mailbox fits in first part of CMDR space */ 973 udev->cmdr_size = CMDR_SIZE - CMDR_OFF; 974 udev->data_off = CMDR_SIZE; 975 udev->data_size = TCMU_RING_SIZE - CMDR_SIZE; 976 977 mb = udev->mb_addr; 978 mb->version = TCMU_MAILBOX_VERSION; 979 mb->flags = TCMU_MAILBOX_FLAG_CAP_OOOC; 980 mb->cmdr_off = CMDR_OFF; 981 mb->cmdr_size = udev->cmdr_size; 982 983 WARN_ON(!PAGE_ALIGNED(udev->data_off)); 984 WARN_ON(udev->data_size % PAGE_SIZE); 985 WARN_ON(udev->data_size % DATA_BLOCK_SIZE); 986 987 info->version = __stringify(TCMU_MAILBOX_VERSION); 988 989 info->mem[0].name = "tcm-user command & data buffer"; 990 info->mem[0].addr = (phys_addr_t)(uintptr_t)udev->mb_addr; 991 info->mem[0].size = TCMU_RING_SIZE; 992 info->mem[0].memtype = UIO_MEM_VIRTUAL; 993 994 info->irqcontrol = tcmu_irqcontrol; 995 info->irq = UIO_IRQ_CUSTOM; 996 997 info->mmap = tcmu_mmap; 998 info->open = tcmu_open; 999 info->release = tcmu_release; 1000 1001 ret = uio_register_device(tcmu_root_device, info); 1002 if (ret) 1003 goto err_register; 1004 1005 /* User can set hw_block_size before enable the device */ 1006 if (dev->dev_attrib.hw_block_size == 0) 1007 dev->dev_attrib.hw_block_size = 512; 1008 /* Other attributes can be configured in userspace */ 1009 if (!dev->dev_attrib.hw_max_sectors) 1010 dev->dev_attrib.hw_max_sectors = 128; 1011 dev->dev_attrib.hw_queue_depth = 128; 1012 1013 ret = tcmu_netlink_event(TCMU_CMD_ADDED_DEVICE, udev->uio_info.name, 1014 udev->uio_info.uio_dev->minor); 1015 if (ret) 1016 goto err_netlink; 1017 1018 return 0; 1019 1020 err_netlink: 1021 uio_unregister_device(&udev->uio_info); 1022 err_register: 1023 vfree(udev->mb_addr); 1024 err_vzalloc: 1025 kfree(info->name); 1026 1027 return ret; 1028 } 1029 1030 static int tcmu_check_and_free_pending_cmd(struct tcmu_cmd *cmd) 1031 { 1032 if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) { 1033 kmem_cache_free(tcmu_cmd_cache, cmd); 1034 return 0; 1035 } 1036 return -EINVAL; 1037 } 1038 1039 static void tcmu_dev_call_rcu(struct rcu_head *p) 1040 { 1041 struct se_device *dev = container_of(p, struct se_device, rcu_head); 1042 struct tcmu_dev *udev = TCMU_DEV(dev); 1043 1044 kfree(udev); 1045 } 1046 1047 static bool tcmu_dev_configured(struct tcmu_dev *udev) 1048 { 1049 return udev->uio_info.uio_dev ? true : false; 1050 } 1051 1052 static void tcmu_free_device(struct se_device *dev) 1053 { 1054 struct tcmu_dev *udev = TCMU_DEV(dev); 1055 struct tcmu_cmd *cmd; 1056 bool all_expired = true; 1057 int i; 1058 1059 del_timer_sync(&udev->timeout); 1060 1061 vfree(udev->mb_addr); 1062 1063 /* Upper layer should drain all requests before calling this */ 1064 spin_lock_irq(&udev->commands_lock); 1065 idr_for_each_entry(&udev->commands, cmd, i) { 1066 if (tcmu_check_and_free_pending_cmd(cmd) != 0) 1067 all_expired = false; 1068 } 1069 idr_destroy(&udev->commands); 1070 spin_unlock_irq(&udev->commands_lock); 1071 WARN_ON(!all_expired); 1072 1073 if (tcmu_dev_configured(udev)) { 1074 tcmu_netlink_event(TCMU_CMD_REMOVED_DEVICE, udev->uio_info.name, 1075 udev->uio_info.uio_dev->minor); 1076 1077 uio_unregister_device(&udev->uio_info); 1078 kfree(udev->uio_info.name); 1079 kfree(udev->name); 1080 } 1081 call_rcu(&dev->rcu_head, tcmu_dev_call_rcu); 1082 } 1083 1084 enum { 1085 Opt_dev_config, Opt_dev_size, Opt_hw_block_size, Opt_hw_max_sectors, 1086 Opt_err, 1087 }; 1088 1089 static match_table_t tokens = { 1090 {Opt_dev_config, "dev_config=%s"}, 1091 {Opt_dev_size, "dev_size=%u"}, 1092 {Opt_hw_block_size, "hw_block_size=%u"}, 1093 {Opt_hw_max_sectors, "hw_max_sectors=%u"}, 1094 {Opt_err, NULL} 1095 }; 1096 1097 static int tcmu_set_dev_attrib(substring_t *arg, u32 *dev_attrib) 1098 { 1099 unsigned long tmp_ul; 1100 char *arg_p; 1101 int ret; 1102 1103 arg_p = match_strdup(arg); 1104 if (!arg_p) 1105 return -ENOMEM; 1106 1107 ret = kstrtoul(arg_p, 0, &tmp_ul); 1108 kfree(arg_p); 1109 if (ret < 0) { 1110 pr_err("kstrtoul() failed for dev attrib\n"); 1111 return ret; 1112 } 1113 if (!tmp_ul) { 1114 pr_err("dev attrib must be nonzero\n"); 1115 return -EINVAL; 1116 } 1117 *dev_attrib = tmp_ul; 1118 return 0; 1119 } 1120 1121 static ssize_t tcmu_set_configfs_dev_params(struct se_device *dev, 1122 const char *page, ssize_t count) 1123 { 1124 struct tcmu_dev *udev = TCMU_DEV(dev); 1125 char *orig, *ptr, *opts, *arg_p; 1126 substring_t args[MAX_OPT_ARGS]; 1127 int ret = 0, token; 1128 1129 opts = kstrdup(page, GFP_KERNEL); 1130 if (!opts) 1131 return -ENOMEM; 1132 1133 orig = opts; 1134 1135 while ((ptr = strsep(&opts, ",\n")) != NULL) { 1136 if (!*ptr) 1137 continue; 1138 1139 token = match_token(ptr, tokens, args); 1140 switch (token) { 1141 case Opt_dev_config: 1142 if (match_strlcpy(udev->dev_config, &args[0], 1143 TCMU_CONFIG_LEN) == 0) { 1144 ret = -EINVAL; 1145 break; 1146 } 1147 pr_debug("TCMU: Referencing Path: %s\n", udev->dev_config); 1148 break; 1149 case Opt_dev_size: 1150 arg_p = match_strdup(&args[0]); 1151 if (!arg_p) { 1152 ret = -ENOMEM; 1153 break; 1154 } 1155 ret = kstrtoul(arg_p, 0, (unsigned long *) &udev->dev_size); 1156 kfree(arg_p); 1157 if (ret < 0) 1158 pr_err("kstrtoul() failed for dev_size=\n"); 1159 break; 1160 case Opt_hw_block_size: 1161 ret = tcmu_set_dev_attrib(&args[0], 1162 &(dev->dev_attrib.hw_block_size)); 1163 break; 1164 case Opt_hw_max_sectors: 1165 ret = tcmu_set_dev_attrib(&args[0], 1166 &(dev->dev_attrib.hw_max_sectors)); 1167 break; 1168 default: 1169 break; 1170 } 1171 1172 if (ret) 1173 break; 1174 } 1175 1176 kfree(orig); 1177 return (!ret) ? count : ret; 1178 } 1179 1180 static ssize_t tcmu_show_configfs_dev_params(struct se_device *dev, char *b) 1181 { 1182 struct tcmu_dev *udev = TCMU_DEV(dev); 1183 ssize_t bl = 0; 1184 1185 bl = sprintf(b + bl, "Config: %s ", 1186 udev->dev_config[0] ? udev->dev_config : "NULL"); 1187 bl += sprintf(b + bl, "Size: %zu\n", udev->dev_size); 1188 1189 return bl; 1190 } 1191 1192 static sector_t tcmu_get_blocks(struct se_device *dev) 1193 { 1194 struct tcmu_dev *udev = TCMU_DEV(dev); 1195 1196 return div_u64(udev->dev_size - dev->dev_attrib.block_size, 1197 dev->dev_attrib.block_size); 1198 } 1199 1200 static sense_reason_t 1201 tcmu_parse_cdb(struct se_cmd *cmd) 1202 { 1203 return passthrough_parse_cdb(cmd, tcmu_queue_cmd); 1204 } 1205 1206 static ssize_t tcmu_cmd_time_out_show(struct config_item *item, char *page) 1207 { 1208 struct se_dev_attrib *da = container_of(to_config_group(item), 1209 struct se_dev_attrib, da_group); 1210 struct tcmu_dev *udev = container_of(da->da_dev, 1211 struct tcmu_dev, se_dev); 1212 1213 return snprintf(page, PAGE_SIZE, "%lu\n", udev->cmd_time_out / MSEC_PER_SEC); 1214 } 1215 1216 static ssize_t tcmu_cmd_time_out_store(struct config_item *item, const char *page, 1217 size_t count) 1218 { 1219 struct se_dev_attrib *da = container_of(to_config_group(item), 1220 struct se_dev_attrib, da_group); 1221 struct tcmu_dev *udev = container_of(da->da_dev, 1222 struct tcmu_dev, se_dev); 1223 u32 val; 1224 int ret; 1225 1226 if (da->da_dev->export_count) { 1227 pr_err("Unable to set tcmu cmd_time_out while exports exist\n"); 1228 return -EINVAL; 1229 } 1230 1231 ret = kstrtou32(page, 0, &val); 1232 if (ret < 0) 1233 return ret; 1234 1235 udev->cmd_time_out = val * MSEC_PER_SEC; 1236 return count; 1237 } 1238 CONFIGFS_ATTR(tcmu_, cmd_time_out); 1239 1240 static struct configfs_attribute **tcmu_attrs; 1241 1242 static struct target_backend_ops tcmu_ops = { 1243 .name = "user", 1244 .owner = THIS_MODULE, 1245 .transport_flags = TRANSPORT_FLAG_PASSTHROUGH, 1246 .attach_hba = tcmu_attach_hba, 1247 .detach_hba = tcmu_detach_hba, 1248 .alloc_device = tcmu_alloc_device, 1249 .configure_device = tcmu_configure_device, 1250 .free_device = tcmu_free_device, 1251 .parse_cdb = tcmu_parse_cdb, 1252 .set_configfs_dev_params = tcmu_set_configfs_dev_params, 1253 .show_configfs_dev_params = tcmu_show_configfs_dev_params, 1254 .get_device_type = sbc_get_device_type, 1255 .get_blocks = tcmu_get_blocks, 1256 .tb_dev_attrib_attrs = NULL, 1257 }; 1258 1259 static int __init tcmu_module_init(void) 1260 { 1261 int ret, i, len = 0; 1262 1263 BUILD_BUG_ON((sizeof(struct tcmu_cmd_entry) % TCMU_OP_ALIGN_SIZE) != 0); 1264 1265 tcmu_cmd_cache = kmem_cache_create("tcmu_cmd_cache", 1266 sizeof(struct tcmu_cmd), 1267 __alignof__(struct tcmu_cmd), 1268 0, NULL); 1269 if (!tcmu_cmd_cache) 1270 return -ENOMEM; 1271 1272 tcmu_root_device = root_device_register("tcm_user"); 1273 if (IS_ERR(tcmu_root_device)) { 1274 ret = PTR_ERR(tcmu_root_device); 1275 goto out_free_cache; 1276 } 1277 1278 ret = genl_register_family(&tcmu_genl_family); 1279 if (ret < 0) { 1280 goto out_unreg_device; 1281 } 1282 1283 for (i = 0; passthrough_attrib_attrs[i] != NULL; i++) { 1284 len += sizeof(struct configfs_attribute *); 1285 } 1286 len += sizeof(struct configfs_attribute *) * 2; 1287 1288 tcmu_attrs = kzalloc(len, GFP_KERNEL); 1289 if (!tcmu_attrs) { 1290 ret = -ENOMEM; 1291 goto out_unreg_genl; 1292 } 1293 1294 for (i = 0; passthrough_attrib_attrs[i] != NULL; i++) { 1295 tcmu_attrs[i] = passthrough_attrib_attrs[i]; 1296 } 1297 tcmu_attrs[i] = &tcmu_attr_cmd_time_out; 1298 tcmu_ops.tb_dev_attrib_attrs = tcmu_attrs; 1299 1300 ret = transport_backend_register(&tcmu_ops); 1301 if (ret) 1302 goto out_attrs; 1303 1304 return 0; 1305 1306 out_attrs: 1307 kfree(tcmu_attrs); 1308 out_unreg_genl: 1309 genl_unregister_family(&tcmu_genl_family); 1310 out_unreg_device: 1311 root_device_unregister(tcmu_root_device); 1312 out_free_cache: 1313 kmem_cache_destroy(tcmu_cmd_cache); 1314 1315 return ret; 1316 } 1317 1318 static void __exit tcmu_module_exit(void) 1319 { 1320 target_backend_unregister(&tcmu_ops); 1321 kfree(tcmu_attrs); 1322 genl_unregister_family(&tcmu_genl_family); 1323 root_device_unregister(tcmu_root_device); 1324 kmem_cache_destroy(tcmu_cmd_cache); 1325 } 1326 1327 MODULE_DESCRIPTION("TCM USER subsystem plugin"); 1328 MODULE_AUTHOR("Shaohua Li <shli@kernel.org>"); 1329 MODULE_AUTHOR("Andy Grover <agrover@redhat.com>"); 1330 MODULE_LICENSE("GPL"); 1331 1332 module_init(tcmu_module_init); 1333 module_exit(tcmu_module_exit); 1334