drivers/target/target_core_user.c

   1 /*
   2  * Copyright (C) 2013 Shaohua Li <shli@kernel.org>
   3  * Copyright (C) 2014 Red Hat, Inc.
   4  * Copyright (C) 2015 Arrikto, Inc.
   5  * Copyright (C) 2017 Chinamobile, Inc.
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms and conditions of the GNU General Public License,
   9  * version 2, as published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  14  * more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along with
  17  * this program; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  19  */
  20
  21 #include <linux/spinlock.h>
  22 #include <linux/module.h>
  23 #include <linux/idr.h>
  24 #include <linux/kernel.h>
  25 #include <linux/timer.h>
  26 #include <linux/parser.h>
  27 #include <linux/vmalloc.h>
  28 #include <linux/uio_driver.h>
  29 #include <linux/radix-tree.h>
  30 #include <linux/stringify.h>
  31 #include <linux/bitops.h>
  32 #include <linux/highmem.h>
  33 #include <linux/configfs.h>
  34 #include <linux/mutex.h>
  35 #include <linux/workqueue.h>
  36 #include <net/genetlink.h>
  37 #include <scsi/scsi_common.h>
  38 #include <scsi/scsi_proto.h>
  39 #include <target/target_core_base.h>
  40 #include <target/target_core_fabric.h>
  41 #include <target/target_core_backend.h>
  42
  43 #include <linux/target_core_user.h>
  44
  45 /*
  46  * Define a shared-memory interface for LIO to pass SCSI commands and
  47  * data to userspace for processing. This is to allow backends that
  48  * are too complex for in-kernel support to be possible.
  49  *
  50  * It uses the UIO framework to do a lot of the device-creation and
  51  * introspection work for us.
  52  *
  53  * See the .h file for how the ring is laid out. Note that while the
  54  * command ring is defined, the particulars of the data area are
  55  * not. Offset values in the command entry point to other locations
  56  * internal to the mmap()ed area. There is separate space outside the
  57  * command ring for data buffers. This leaves maximum flexibility for
  58  * moving buffer allocations, or even page flipping or other
  59  * allocation techniques, without altering the command ring layout.
  60  *
  61  * SECURITY:
  62  * The user process must be assumed to be malicious. There's no way to
  63  * prevent it breaking the command ring protocol if it wants, but in
  64  * order to prevent other issues we must only ever read *data* from
  65  * the shared memory area, not offsets or sizes. This applies to
  66  * command ring entries as well as the mailbox. Extra code needed for
  67  * this may have a 'UAM' comment.
  68  */
  69
  70 #define TCMU_TIME_OUT (30 * MSEC_PER_SEC)
  71
  72 /* For cmd area, the size is fixed 8MB */
  73 #define CMDR_SIZE (8 * 1024 * 1024)
  74
  75 /*
  76  * For data area, the block size is PAGE_SIZE and
  77  * the total size is 256K * PAGE_SIZE.
  78  */
  79 #define DATA_BLOCK_SIZE PAGE_SIZE
  80 #define DATA_BLOCK_SHIFT PAGE_SHIFT
  81 #define DATA_BLOCK_BITS_DEF (256 * 1024)
  82 #define DATA_SIZE (DATA_BLOCK_BITS * DATA_BLOCK_SIZE)
  83
  84 #define TCMU_MBS_TO_BLOCKS(_mbs) (_mbs << (20 - DATA_BLOCK_SHIFT))
  85 #define TCMU_BLOCKS_TO_MBS(_blocks) (_blocks >> (20 - DATA_BLOCK_SHIFT))
  86
  87 /* The total size of the ring is 8M + 256K * PAGE_SIZE */
  88 #define TCMU_RING_SIZE (CMDR_SIZE + DATA_SIZE)
  89
  90 /*
  91  * Default number of global data blocks(512K * PAGE_SIZE)
  92  * when the unmap thread will be started.
  93  */
  94 #define TCMU_GLOBAL_MAX_BLOCKS_DEF (512 * 1024)
  95
  96 static u8 tcmu_kern_cmd_reply_supported;
  97
  98 static struct device *tcmu_root_device;
  99
 100 struct tcmu_hba {
 101         u32 host_id;
 102 };
 103
 104 #define TCMU_CONFIG_LEN 256
 105
 106 struct tcmu_nl_cmd {
 107         /* wake up thread waiting for reply */
 108         struct completion complete;
 109         int cmd;
 110         int status;
 111 };
 112
 113 struct tcmu_dev {
 114         struct list_head node;
 115         struct kref kref;
 116
 117         struct se_device se_dev;
 118
 119         char *name;
 120         struct se_hba *hba;
 121
 122 #define TCMU_DEV_BIT_OPEN 0
 123 #define TCMU_DEV_BIT_BROKEN 1
 124 #define TCMU_DEV_BIT_BLOCKED 2
 125         unsigned long flags;
 126
 127         struct uio_info uio_info;
 128
 129         struct inode *inode;
 130
 131         struct tcmu_mailbox *mb_addr;
 132         size_t dev_size;
 133         u32 cmdr_size;
 134         u32 cmdr_last_cleaned;
 135         /* Offset of data area from start of mb */
 136         /* Must add data_off and mb_addr to get the address */
 137         size_t data_off;
 138         size_t data_size;
 139         uint32_t max_blocks;
 140         size_t ring_size;
 141
 142         struct mutex cmdr_lock;
 143         struct list_head cmdr_queue;
 144
 145         uint32_t dbi_max;
 146         uint32_t dbi_thresh;
 147         unsigned long *data_bitmap;
 148         struct radix_tree_root data_blocks;
 149
 150         struct idr commands;
 151
 152         struct timer_list cmd_timer;
 153         unsigned int cmd_time_out;
 154
 155         struct timer_list qfull_timer;
 156         int qfull_time_out;
 157
 158         struct list_head timedout_entry;
 159
 160         spinlock_t nl_cmd_lock;
 161         struct tcmu_nl_cmd curr_nl_cmd;
 162         /* wake up threads waiting on curr_nl_cmd */
 163         wait_queue_head_t nl_cmd_wq;
 164
 165         char dev_config[TCMU_CONFIG_LEN];
 166
 167         int nl_reply_supported;
 168 };
 169
 170 #define TCMU_DEV(_se_dev) container_of(_se_dev, struct tcmu_dev, se_dev)
 171
 172 #define CMDR_OFF sizeof(struct tcmu_mailbox)
 173
 174 struct tcmu_cmd {
 175         struct se_cmd *se_cmd;
 176         struct tcmu_dev *tcmu_dev;
 177         struct list_head cmdr_queue_entry;
 178
 179         uint16_t cmd_id;
 180
 181         /* Can't use se_cmd when cleaning up expired cmds, because if
 182            cmd has been completed then accessing se_cmd is off limits */
 183         uint32_t dbi_cnt;
 184         uint32_t dbi_cur;
 185         uint32_t *dbi;
 186
 187         unsigned long deadline;
 188
 189 #define TCMU_CMD_BIT_EXPIRED 0
 190         unsigned long flags;
 191 };
 192 /*
 193  * To avoid dead lock the mutex lock order should always be:
 194  *
 195  * mutex_lock(&root_udev_mutex);
 196  * ...
 197  * mutex_lock(&tcmu_dev->cmdr_lock);
 198  * mutex_unlock(&tcmu_dev->cmdr_lock);
 199  * ...
 200  * mutex_unlock(&root_udev_mutex);
 201  */
 202 static DEFINE_MUTEX(root_udev_mutex);
 203 static LIST_HEAD(root_udev);
 204
 205 static DEFINE_SPINLOCK(timed_out_udevs_lock);
 206 static LIST_HEAD(timed_out_udevs);
 207
 208 static struct kmem_cache *tcmu_cmd_cache;
 209
 210 static atomic_t global_db_count = ATOMIC_INIT(0);
 211 static struct delayed_work tcmu_unmap_work;
 212 static int tcmu_global_max_blocks = TCMU_GLOBAL_MAX_BLOCKS_DEF;
 213
 214 static int tcmu_set_global_max_data_area(const char *str,
 215                                          const struct kernel_param *kp)
 216 {
 217         int ret, max_area_mb;
 218
 219         ret = kstrtoint(str, 10, &max_area_mb);
 220         if (ret)
 221                 return -EINVAL;
 222
 223         if (max_area_mb <= 0) {
 224                 pr_err("global_max_data_area must be larger than 0.\n");
 225                 return -EINVAL;
 226         }
 227
 228         tcmu_global_max_blocks = TCMU_MBS_TO_BLOCKS(max_area_mb);
 229         if (atomic_read(&global_db_count) > tcmu_global_max_blocks)
 230                 schedule_delayed_work(&tcmu_unmap_work, 0);
 231         else
 232                 cancel_delayed_work_sync(&tcmu_unmap_work);
 233
 234         return 0;
 235 }
 236
 237 static int tcmu_get_global_max_data_area(char *buffer,
 238                                          const struct kernel_param *kp)
 239 {
 240         return sprintf(buffer, "%d", TCMU_BLOCKS_TO_MBS(tcmu_global_max_blocks));
 241 }
 242
 243 static const struct kernel_param_ops tcmu_global_max_data_area_op = {
 244         .set = tcmu_set_global_max_data_area,
 245         .get = tcmu_get_global_max_data_area,
 246 };
 247
 248 module_param_cb(global_max_data_area_mb, &tcmu_global_max_data_area_op, NULL,
 249                 S_IWUSR | S_IRUGO);
 250 MODULE_PARM_DESC(global_max_data_area_mb,
 251                  "Max MBs allowed to be allocated to all the tcmu device's "
 252                  "data areas.");
 253
 254 /* multicast group */
 255 enum tcmu_multicast_groups {
 256         TCMU_MCGRP_CONFIG,
 257 };
 258
 259 static const struct genl_multicast_group tcmu_mcgrps[] = {
 260         [TCMU_MCGRP_CONFIG] = { .name = "config", },
 261 };
 262
 263 static struct nla_policy tcmu_attr_policy[TCMU_ATTR_MAX+1] = {
 264         [TCMU_ATTR_DEVICE]      = { .type = NLA_STRING },
 265         [TCMU_ATTR_MINOR]       = { .type = NLA_U32 },
 266         [TCMU_ATTR_CMD_STATUS]  = { .type = NLA_S32 },
 267         [TCMU_ATTR_DEVICE_ID]   = { .type = NLA_U32 },
 268         [TCMU_ATTR_SUPP_KERN_CMD_REPLY] = { .type = NLA_U8 },
 269 };
 270
 271 static int tcmu_genl_cmd_done(struct genl_info *info, int completed_cmd)
 272 {
 273         struct se_device *dev;
 274         struct tcmu_dev *udev;
 275         struct tcmu_nl_cmd *nl_cmd;
 276         int dev_id, rc, ret = 0;
 277         bool is_removed = (completed_cmd == TCMU_CMD_REMOVED_DEVICE);
 278
 279         if (!info->attrs[TCMU_ATTR_CMD_STATUS] ||
 280             !info->attrs[TCMU_ATTR_DEVICE_ID]) {
 281                 printk(KERN_ERR "TCMU_ATTR_CMD_STATUS or TCMU_ATTR_DEVICE_ID not set, doing nothing\n");
 282                 return -EINVAL;
 283         }
 284
 285         dev_id = nla_get_u32(info->attrs[TCMU_ATTR_DEVICE_ID]);
 286         rc = nla_get_s32(info->attrs[TCMU_ATTR_CMD_STATUS]);
 287
 288         dev = target_find_device(dev_id, !is_removed);
 289         if (!dev) {
 290                 printk(KERN_ERR "tcmu nl cmd %u/%u completion could not find device with dev id %u.\n",
 291                        completed_cmd, rc, dev_id);
 292                 return -ENODEV;
 293         }
 294         udev = TCMU_DEV(dev);
 295
 296         spin_lock(&udev->nl_cmd_lock);
 297         nl_cmd = &udev->curr_nl_cmd;
 298
 299         pr_debug("genl cmd done got id %d curr %d done %d rc %d\n", dev_id,
 300                  nl_cmd->cmd, completed_cmd, rc);
 301
 302         if (nl_cmd->cmd != completed_cmd) {
 303                 printk(KERN_ERR "Mismatched commands (Expecting reply for %d. Current %d).\n",
 304                        completed_cmd, nl_cmd->cmd);
 305                 ret = -EINVAL;
 306         } else {
 307                 nl_cmd->status = rc;
 308         }
 309
 310         spin_unlock(&udev->nl_cmd_lock);
 311         if (!is_removed)
 312                  target_undepend_item(&dev->dev_group.cg_item);
 313         if (!ret)
 314                 complete(&nl_cmd->complete);
 315         return ret;
 316 }
 317
 318 static int tcmu_genl_rm_dev_done(struct sk_buff *skb, struct genl_info *info)
 319 {
 320         return tcmu_genl_cmd_done(info, TCMU_CMD_REMOVED_DEVICE);
 321 }
 322
 323 static int tcmu_genl_add_dev_done(struct sk_buff *skb, struct genl_info *info)
 324 {
 325         return tcmu_genl_cmd_done(info, TCMU_CMD_ADDED_DEVICE);
 326 }
 327
 328 static int tcmu_genl_reconfig_dev_done(struct sk_buff *skb,
 329                                        struct genl_info *info)
 330 {
 331         return tcmu_genl_cmd_done(info, TCMU_CMD_RECONFIG_DEVICE);
 332 }
 333
 334 static int tcmu_genl_set_features(struct sk_buff *skb, struct genl_info *info)
 335 {
 336         if (info->attrs[TCMU_ATTR_SUPP_KERN_CMD_REPLY]) {
 337                 tcmu_kern_cmd_reply_supported  =
 338                         nla_get_u8(info->attrs[TCMU_ATTR_SUPP_KERN_CMD_REPLY]);
 339                 printk(KERN_INFO "tcmu daemon: command reply support %u.\n",
 340                        tcmu_kern_cmd_reply_supported);
 341         }
 342
 343         return 0;
 344 }
 345
 346 static const struct genl_ops tcmu_genl_ops[] = {
 347         {
 348                 .cmd    = TCMU_CMD_SET_FEATURES,
 349                 .flags  = GENL_ADMIN_PERM,
 350                 .policy = tcmu_attr_policy,
 351                 .doit   = tcmu_genl_set_features,
 352         },
 353         {
 354                 .cmd    = TCMU_CMD_ADDED_DEVICE_DONE,
 355                 .flags  = GENL_ADMIN_PERM,
 356                 .policy = tcmu_attr_policy,
 357                 .doit   = tcmu_genl_add_dev_done,
 358         },
 359         {
 360                 .cmd    = TCMU_CMD_REMOVED_DEVICE_DONE,
 361                 .flags  = GENL_ADMIN_PERM,
 362                 .policy = tcmu_attr_policy,
 363                 .doit   = tcmu_genl_rm_dev_done,
 364         },
 365         {
 366                 .cmd    = TCMU_CMD_RECONFIG_DEVICE_DONE,
 367                 .flags  = GENL_ADMIN_PERM,
 368                 .policy = tcmu_attr_policy,
 369                 .doit   = tcmu_genl_reconfig_dev_done,
 370         },
 371 };
 372
 373 /* Our generic netlink family */
 374 static struct genl_family tcmu_genl_family __ro_after_init = {
 375         .module = THIS_MODULE,
 376         .hdrsize = 0,
 377         .name = "TCM-USER",
 378         .version = 2,
 379         .maxattr = TCMU_ATTR_MAX,
 380         .mcgrps = tcmu_mcgrps,
 381         .n_mcgrps = ARRAY_SIZE(tcmu_mcgrps),
 382         .netnsok = true,
 383         .ops = tcmu_genl_ops,
 384         .n_ops = ARRAY_SIZE(tcmu_genl_ops),
 385 };
 386
 387 #define tcmu_cmd_set_dbi_cur(cmd, index) ((cmd)->dbi_cur = (index))
 388 #define tcmu_cmd_reset_dbi_cur(cmd) tcmu_cmd_set_dbi_cur(cmd, 0)
 389 #define tcmu_cmd_set_dbi(cmd, index) ((cmd)->dbi[(cmd)->dbi_cur++] = (index))
 390 #define tcmu_cmd_get_dbi(cmd) ((cmd)->dbi[(cmd)->dbi_cur++])
 391
 392 static void tcmu_cmd_free_data(struct tcmu_cmd *tcmu_cmd, uint32_t len)
 393 {
 394         struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
 395         uint32_t i;
 396
 397         for (i = 0; i < len; i++)
 398                 clear_bit(tcmu_cmd->dbi[i], udev->data_bitmap);
 399 }
 400
 401 static inline bool tcmu_get_empty_block(struct tcmu_dev *udev,
 402                                         struct tcmu_cmd *tcmu_cmd)
 403 {
 404         struct page *page;
 405         int ret, dbi;
 406
 407         dbi = find_first_zero_bit(udev->data_bitmap, udev->dbi_thresh);
 408         if (dbi == udev->dbi_thresh)
 409                 return false;
 410
 411         page = radix_tree_lookup(&udev->data_blocks, dbi);
 412         if (!page) {
 413                 if (atomic_add_return(1, &global_db_count) >
 414                                       tcmu_global_max_blocks)
 415                         schedule_delayed_work(&tcmu_unmap_work, 0);
 416
 417                 /* try to get new page from the mm */
 418                 page = alloc_page(GFP_KERNEL);
 419                 if (!page)
 420                         goto err_alloc;
 421
 422                 ret = radix_tree_insert(&udev->data_blocks, dbi, page);
 423                 if (ret)
 424                         goto err_insert;
 425         }
 426
 427         if (dbi > udev->dbi_max)
 428                 udev->dbi_max = dbi;
 429
 430         set_bit(dbi, udev->data_bitmap);
 431         tcmu_cmd_set_dbi(tcmu_cmd, dbi);
 432
 433         return true;
 434 err_insert:
 435         __free_page(page);
 436 err_alloc:
 437         atomic_dec(&global_db_count);
 438         return false;
 439 }
 440
 441 static bool tcmu_get_empty_blocks(struct tcmu_dev *udev,
 442                                   struct tcmu_cmd *tcmu_cmd)
 443 {
 444         int i;
 445
 446         for (i = tcmu_cmd->dbi_cur; i < tcmu_cmd->dbi_cnt; i++) {
 447                 if (!tcmu_get_empty_block(udev, tcmu_cmd))
 448                         return false;
 449         }
 450         return true;
 451 }
 452
 453 static inline struct page *
 454 tcmu_get_block_page(struct tcmu_dev *udev, uint32_t dbi)
 455 {
 456         return radix_tree_lookup(&udev->data_blocks, dbi);
 457 }
 458
 459 static inline void tcmu_free_cmd(struct tcmu_cmd *tcmu_cmd)
 460 {
 461         kfree(tcmu_cmd->dbi);
 462         kmem_cache_free(tcmu_cmd_cache, tcmu_cmd);
 463 }
 464
 465 static inline size_t tcmu_cmd_get_data_length(struct tcmu_cmd *tcmu_cmd)
 466 {
 467         struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
 468         size_t data_length = round_up(se_cmd->data_length, DATA_BLOCK_SIZE);
 469
 470         if (se_cmd->se_cmd_flags & SCF_BIDI) {
 471                 BUG_ON(!(se_cmd->t_bidi_data_sg && se_cmd->t_bidi_data_nents));
 472                 data_length += round_up(se_cmd->t_bidi_data_sg->length,
 473                                 DATA_BLOCK_SIZE);
 474         }
 475
 476         return data_length;
 477 }
 478
 479 static inline uint32_t tcmu_cmd_get_block_cnt(struct tcmu_cmd *tcmu_cmd)
 480 {
 481         size_t data_length = tcmu_cmd_get_data_length(tcmu_cmd);
 482
 483         return data_length / DATA_BLOCK_SIZE;
 484 }
 485
 486 static struct tcmu_cmd *tcmu_alloc_cmd(struct se_cmd *se_cmd)
 487 {
 488         struct se_device *se_dev = se_cmd->se_dev;
 489         struct tcmu_dev *udev = TCMU_DEV(se_dev);
 490         struct tcmu_cmd *tcmu_cmd;
 491
 492         tcmu_cmd = kmem_cache_zalloc(tcmu_cmd_cache, GFP_KERNEL);
 493         if (!tcmu_cmd)
 494                 return NULL;
 495
 496         INIT_LIST_HEAD(&tcmu_cmd->cmdr_queue_entry);
 497         tcmu_cmd->se_cmd = se_cmd;
 498         tcmu_cmd->tcmu_dev = udev;
 499
 500         tcmu_cmd_reset_dbi_cur(tcmu_cmd);
 501         tcmu_cmd->dbi_cnt = tcmu_cmd_get_block_cnt(tcmu_cmd);
 502         tcmu_cmd->dbi = kcalloc(tcmu_cmd->dbi_cnt, sizeof(uint32_t),
 503                                 GFP_KERNEL);
 504         if (!tcmu_cmd->dbi) {
 505                 kmem_cache_free(tcmu_cmd_cache, tcmu_cmd);
 506                 return NULL;
 507         }
 508
 509         return tcmu_cmd;
 510 }
 511
 512 static inline void tcmu_flush_dcache_range(void *vaddr, size_t size)
 513 {
 514         unsigned long offset = offset_in_page(vaddr);
 515         void *start = vaddr - offset;
 516
 517         size = round_up(size+offset, PAGE_SIZE);
 518
 519         while (size) {
 520                 flush_dcache_page(virt_to_page(start));
 521                 start += PAGE_SIZE;
 522                 size -= PAGE_SIZE;
 523         }
 524 }
 525
 526 /*
 527  * Some ring helper functions. We don't assume size is a power of 2 so
 528  * we can't use circ_buf.h.
 529  */
 530 static inline size_t spc_used(size_t head, size_t tail, size_t size)
 531 {
 532         int diff = head - tail;
 533
 534         if (diff >= 0)
 535                 return diff;
 536         else
 537                 return size + diff;
 538 }
 539
 540 static inline size_t spc_free(size_t head, size_t tail, size_t size)
 541 {
 542         /* Keep 1 byte unused or we can't tell full from empty */
 543         return (size - spc_used(head, tail, size) - 1);
 544 }
 545
 546 static inline size_t head_to_end(size_t head, size_t size)
 547 {
 548         return size - head;
 549 }
 550
 551 static inline void new_iov(struct iovec **iov, int *iov_cnt)
 552 {
 553         struct iovec *iovec;
 554
 555         if (*iov_cnt != 0)
 556                 (*iov)++;
 557         (*iov_cnt)++;
 558
 559         iovec = *iov;
 560         memset(iovec, 0, sizeof(struct iovec));
 561 }
 562
 563 #define UPDATE_HEAD(head, used, size) smp_store_release(&head, ((head % size) + used) % size)
 564
 565 /* offset is relative to mb_addr */
 566 static inline size_t get_block_offset_user(struct tcmu_dev *dev,
 567                 int dbi, int remaining)
 568 {
 569         return dev->data_off + dbi * DATA_BLOCK_SIZE +
 570                 DATA_BLOCK_SIZE - remaining;
 571 }
 572
 573 static inline size_t iov_tail(struct iovec *iov)
 574 {
 575         return (size_t)iov->iov_base + iov->iov_len;
 576 }
 577
 578 static void scatter_data_area(struct tcmu_dev *udev,
 579         struct tcmu_cmd *tcmu_cmd, struct scatterlist *data_sg,
 580         unsigned int data_nents, struct iovec **iov,
 581         int *iov_cnt, bool copy_data)
 582 {
 583         int i, dbi;
 584         int block_remaining = 0;
 585         void *from, *to = NULL;
 586         size_t copy_bytes, to_offset, offset;
 587         struct scatterlist *sg;
 588         struct page *page;
 589
 590         for_each_sg(data_sg, sg, data_nents, i) {
 591                 int sg_remaining = sg->length;
 592                 from = kmap_atomic(sg_page(sg)) + sg->offset;
 593                 while (sg_remaining > 0) {
 594                         if (block_remaining == 0) {
 595                                 if (to)
 596                                         kunmap_atomic(to);
 597
 598                                 block_remaining = DATA_BLOCK_SIZE;
 599                                 dbi = tcmu_cmd_get_dbi(tcmu_cmd);
 600                                 page = tcmu_get_block_page(udev, dbi);
 601                                 to = kmap_atomic(page);
 602                         }
 603
 604                         /*
 605                          * Covert to virtual offset of the ring data area.
 606                          */
 607                         to_offset = get_block_offset_user(udev, dbi,
 608                                         block_remaining);
 609
 610                         /*
 611                          * The following code will gather and map the blocks
 612                          * to the same iovec when the blocks are all next to
 613                          * each other.
 614                          */
 615                         copy_bytes = min_t(size_t, sg_remaining,
 616                                         block_remaining);
 617                         if (*iov_cnt != 0 &&
 618                             to_offset == iov_tail(*iov)) {
 619                                 /*
 620                                  * Will append to the current iovec, because
 621                                  * the current block page is next to the
 622                                  * previous one.
 623                                  */
 624                                 (*iov)->iov_len += copy_bytes;
 625                         } else {
 626                                 /*
 627                                  * Will allocate a new iovec because we are
 628                                  * first time here or the current block page
 629                                  * is not next to the previous one.
 630                                  */
 631                                 new_iov(iov, iov_cnt);
 632                                 (*iov)->iov_base = (void __user *)to_offset;
 633                                 (*iov)->iov_len = copy_bytes;
 634                         }
 635
 636                         if (copy_data) {
 637                                 offset = DATA_BLOCK_SIZE - block_remaining;
 638                                 memcpy(to + offset,
 639                                        from + sg->length - sg_remaining,
 640                                        copy_bytes);
 641                                 tcmu_flush_dcache_range(to, copy_bytes);
 642                         }
 643
 644                         sg_remaining -= copy_bytes;
 645                         block_remaining -= copy_bytes;
 646                 }
 647                 kunmap_atomic(from - sg->offset);
 648         }
 649
 650         if (to)
 651                 kunmap_atomic(to);
 652 }
 653
 654 static void gather_data_area(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
 655                              bool bidi)
 656 {
 657         struct se_cmd *se_cmd = cmd->se_cmd;
 658         int i, dbi;
 659         int block_remaining = 0;
 660         void *from = NULL, *to;
 661         size_t copy_bytes, offset;
 662         struct scatterlist *sg, *data_sg;
 663         struct page *page;
 664         unsigned int data_nents;
 665         uint32_t count = 0;
 666
 667         if (!bidi) {
 668                 data_sg = se_cmd->t_data_sg;
 669                 data_nents = se_cmd->t_data_nents;
 670         } else {
 671
 672                 /*
 673                  * For bidi case, the first count blocks are for Data-Out
 674                  * buffer blocks, and before gathering the Data-In buffer
 675                  * the Data-Out buffer blocks should be discarded.
 676                  */
 677                 count = DIV_ROUND_UP(se_cmd->data_length, DATA_BLOCK_SIZE);
 678
 679                 data_sg = se_cmd->t_bidi_data_sg;
 680                 data_nents = se_cmd->t_bidi_data_nents;
 681         }
 682
 683         tcmu_cmd_set_dbi_cur(cmd, count);
 684
 685         for_each_sg(data_sg, sg, data_nents, i) {
 686                 int sg_remaining = sg->length;
 687                 to = kmap_atomic(sg_page(sg)) + sg->offset;
 688                 while (sg_remaining > 0) {
 689                         if (block_remaining == 0) {
 690                                 if (from)
 691                                         kunmap_atomic(from);
 692
 693                                 block_remaining = DATA_BLOCK_SIZE;
 694                                 dbi = tcmu_cmd_get_dbi(cmd);
 695                                 page = tcmu_get_block_page(udev, dbi);
 696                                 from = kmap_atomic(page);
 697                         }
 698                         copy_bytes = min_t(size_t, sg_remaining,
 699                                         block_remaining);
 700                         offset = DATA_BLOCK_SIZE - block_remaining;
 701                         tcmu_flush_dcache_range(from, copy_bytes);
 702                         memcpy(to + sg->length - sg_remaining, from + offset,
 703                                         copy_bytes);
 704
 705                         sg_remaining -= copy_bytes;
 706                         block_remaining -= copy_bytes;
 707                 }
 708                 kunmap_atomic(to - sg->offset);
 709         }
 710         if (from)
 711                 kunmap_atomic(from);
 712 }
 713
 714 static inline size_t spc_bitmap_free(unsigned long *bitmap, uint32_t thresh)
 715 {
 716         return thresh - bitmap_weight(bitmap, thresh);
 717 }
 718
 719 /*
 720  * We can't queue a command until we have space available on the cmd ring *and*
 721  * space available on the data area.
 722  *
 723  * Called with ring lock held.
 724  */
 725 static bool is_ring_space_avail(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
 726                 size_t cmd_size, size_t data_needed)
 727 {
 728         struct tcmu_mailbox *mb = udev->mb_addr;
 729         uint32_t blocks_needed = (data_needed + DATA_BLOCK_SIZE - 1)
 730                                 / DATA_BLOCK_SIZE;
 731         size_t space, cmd_needed;
 732         u32 cmd_head;
 733
 734         tcmu_flush_dcache_range(mb, sizeof(*mb));
 735
 736         cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
 737
 738         /*
 739          * If cmd end-of-ring space is too small then we need space for a NOP plus
 740          * original cmd - cmds are internally contiguous.
 741          */
 742         if (head_to_end(cmd_head, udev->cmdr_size) >= cmd_size)
 743                 cmd_needed = cmd_size;
 744         else
 745                 cmd_needed = cmd_size + head_to_end(cmd_head, udev->cmdr_size);
 746
 747         space = spc_free(cmd_head, udev->cmdr_last_cleaned, udev->cmdr_size);
 748         if (space < cmd_needed) {
 749                 pr_debug("no cmd space: %u %u %u\n", cmd_head,
 750                        udev->cmdr_last_cleaned, udev->cmdr_size);
 751                 return false;
 752         }
 753
 754         /* try to check and get the data blocks as needed */
 755         space = spc_bitmap_free(udev->data_bitmap, udev->dbi_thresh);
 756         if ((space * DATA_BLOCK_SIZE) < data_needed) {
 757                 unsigned long blocks_left =
 758                                 (udev->max_blocks - udev->dbi_thresh) + space;
 759
 760                 if (blocks_left < blocks_needed) {
 761                         pr_debug("no data space: only %lu available, but ask for %zu\n",
 762                                         blocks_left * DATA_BLOCK_SIZE,
 763                                         data_needed);
 764                         return false;
 765                 }
 766
 767                 udev->dbi_thresh += blocks_needed;
 768                 if (udev->dbi_thresh > udev->max_blocks)
 769                         udev->dbi_thresh = udev->max_blocks;
 770         }
 771
 772         return tcmu_get_empty_blocks(udev, cmd);
 773 }
 774
 775 static inline size_t tcmu_cmd_get_base_cmd_size(size_t iov_cnt)
 776 {
 777         return max(offsetof(struct tcmu_cmd_entry, req.iov[iov_cnt]),
 778                         sizeof(struct tcmu_cmd_entry));
 779 }
 780
 781 static inline size_t tcmu_cmd_get_cmd_size(struct tcmu_cmd *tcmu_cmd,
 782                                            size_t base_command_size)
 783 {
 784         struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
 785         size_t command_size;
 786
 787         command_size = base_command_size +
 788                 round_up(scsi_command_size(se_cmd->t_task_cdb),
 789                                 TCMU_OP_ALIGN_SIZE);
 790
 791         WARN_ON(command_size & (TCMU_OP_ALIGN_SIZE-1));
 792
 793         return command_size;
 794 }
 795
 796 static int tcmu_setup_cmd_timer(struct tcmu_cmd *tcmu_cmd, unsigned int tmo,
 797                                 struct timer_list *timer)
 798 {
 799         struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
 800         int cmd_id;
 801
 802         if (tcmu_cmd->cmd_id)
 803                 goto setup_timer;
 804
 805         cmd_id = idr_alloc(&udev->commands, tcmu_cmd, 1, USHRT_MAX, GFP_NOWAIT);
 806         if (cmd_id < 0) {
 807                 pr_err("tcmu: Could not allocate cmd id.\n");
 808                 return cmd_id;
 809         }
 810         tcmu_cmd->cmd_id = cmd_id;
 811
 812         pr_debug("allocated cmd %u for dev %s tmo %lu\n", tcmu_cmd->cmd_id,
 813                  udev->name, tmo / MSEC_PER_SEC);
 814
 815 setup_timer:
 816         if (!tmo)
 817                 return 0;
 818
 819         tcmu_cmd->deadline = round_jiffies_up(jiffies + msecs_to_jiffies(tmo));
 820         mod_timer(timer, tcmu_cmd->deadline);
 821         return 0;
 822 }
 823
 824 static int add_to_cmdr_queue(struct tcmu_cmd *tcmu_cmd)
 825 {
 826         struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
 827         unsigned int tmo;
 828         int ret;
 829
 830         /*
 831          * For backwards compat if qfull_time_out is not set use
 832          * cmd_time_out and if that's not set use the default time out.
 833          */
 834         if (!udev->qfull_time_out)
 835                 return -ETIMEDOUT;
 836         else if (udev->qfull_time_out > 0)
 837                 tmo = udev->qfull_time_out;
 838         else if (udev->cmd_time_out)
 839                 tmo = udev->cmd_time_out;
 840         else
 841                 tmo = TCMU_TIME_OUT;
 842
 843         ret = tcmu_setup_cmd_timer(tcmu_cmd, tmo, &udev->qfull_timer);
 844         if (ret)
 845                 return ret;
 846
 847         list_add_tail(&tcmu_cmd->cmdr_queue_entry, &udev->cmdr_queue);
 848         pr_debug("adding cmd %u on dev %s to ring space wait queue\n",
 849                  tcmu_cmd->cmd_id, udev->name);
 850         return 0;
 851 }
 852
 853 /**
 854  * queue_cmd_ring - queue cmd to ring or internally
 855  * @tcmu_cmd: cmd to queue
 856  * @scsi_err: TCM error code if failure (-1) returned.
 857  *
 858  * Returns:
 859  * -1 we cannot queue internally or to the ring.
 860  *  0 success
 861  *  1 internally queued to wait for ring memory to free.
 862  */
 863 static sense_reason_t queue_cmd_ring(struct tcmu_cmd *tcmu_cmd, int *scsi_err)
 864 {
 865         struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
 866         struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
 867         size_t base_command_size, command_size;
 868         struct tcmu_mailbox *mb;
 869         struct tcmu_cmd_entry *entry;
 870         struct iovec *iov;
 871         int iov_cnt, ret;
 872         uint32_t cmd_head;
 873         uint64_t cdb_off;
 874         bool copy_to_data_area;
 875         size_t data_length = tcmu_cmd_get_data_length(tcmu_cmd);
 876
 877         *scsi_err = TCM_NO_SENSE;
 878
 879         if (test_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags)) {
 880                 *scsi_err = TCM_LUN_BUSY;
 881                 return -1;
 882         }
 883
 884         if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) {
 885                 *scsi_err = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 886                 return -1;
 887         }
 888
 889         /*
 890          * Must be a certain minimum size for response sense info, but
 891          * also may be larger if the iov array is large.
 892          *
 893          * We prepare as many iovs as possbile for potential uses here,
 894          * because it's expensive to tell how many regions are freed in
 895          * the bitmap & global data pool, as the size calculated here
 896          * will only be used to do the checks.
 897          *
 898          * The size will be recalculated later as actually needed to save
 899          * cmd area memories.
 900          */
 901         base_command_size = tcmu_cmd_get_base_cmd_size(tcmu_cmd->dbi_cnt);
 902         command_size = tcmu_cmd_get_cmd_size(tcmu_cmd, base_command_size);
 903
 904         if (!list_empty(&udev->cmdr_queue))
 905                 goto queue;
 906
 907         mb = udev->mb_addr;
 908         cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
 909         if ((command_size > (udev->cmdr_size / 2)) ||
 910             data_length > udev->data_size) {
 911                 pr_warn("TCMU: Request of size %zu/%zu is too big for %u/%zu "
 912                         "cmd ring/data area\n", command_size, data_length,
 913                         udev->cmdr_size, udev->data_size);
 914                 *scsi_err = TCM_INVALID_CDB_FIELD;
 915                 return -1;
 916         }
 917
 918         if (!is_ring_space_avail(udev, tcmu_cmd, command_size, data_length)) {
 919                 /*
 920                  * Don't leave commands partially setup because the unmap
 921                  * thread might need the blocks to make forward progress.
 922                  */
 923                 tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cur);
 924                 tcmu_cmd_reset_dbi_cur(tcmu_cmd);
 925                 goto queue;
 926         }
 927
 928         /* Insert a PAD if end-of-ring space is too small */
 929         if (head_to_end(cmd_head, udev->cmdr_size) < command_size) {
 930                 size_t pad_size = head_to_end(cmd_head, udev->cmdr_size);
 931
 932                 entry = (void *) mb + CMDR_OFF + cmd_head;
 933                 tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_PAD);
 934                 tcmu_hdr_set_len(&entry->hdr.len_op, pad_size);
 935                 entry->hdr.cmd_id = 0; /* not used for PAD */
 936                 entry->hdr.kflags = 0;
 937                 entry->hdr.uflags = 0;
 938                 tcmu_flush_dcache_range(entry, sizeof(*entry));
 939
 940                 UPDATE_HEAD(mb->cmd_head, pad_size, udev->cmdr_size);
 941                 tcmu_flush_dcache_range(mb, sizeof(*mb));
 942
 943                 cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
 944                 WARN_ON(cmd_head != 0);
 945         }
 946
 947         entry = (void *) mb + CMDR_OFF + cmd_head;
 948         memset(entry, 0, command_size);
 949         tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_CMD);
 950
 951         /* Handle allocating space from the data area */
 952         tcmu_cmd_reset_dbi_cur(tcmu_cmd);
 953         iov = &entry->req.iov[0];
 954         iov_cnt = 0;
 955         copy_to_data_area = (se_cmd->data_direction == DMA_TO_DEVICE
 956                 || se_cmd->se_cmd_flags & SCF_BIDI);
 957         scatter_data_area(udev, tcmu_cmd, se_cmd->t_data_sg,
 958                           se_cmd->t_data_nents, &iov, &iov_cnt,
 959                           copy_to_data_area);
 960         entry->req.iov_cnt = iov_cnt;
 961
 962         /* Handle BIDI commands */
 963         iov_cnt = 0;
 964         if (se_cmd->se_cmd_flags & SCF_BIDI) {
 965                 iov++;
 966                 scatter_data_area(udev, tcmu_cmd, se_cmd->t_bidi_data_sg,
 967                                   se_cmd->t_bidi_data_nents, &iov, &iov_cnt,
 968                                   false);
 969         }
 970         entry->req.iov_bidi_cnt = iov_cnt;
 971
 972         ret = tcmu_setup_cmd_timer(tcmu_cmd, udev->cmd_time_out,
 973                                    &udev->cmd_timer);
 974         if (ret) {
 975                 tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cnt);
 976                 mutex_unlock(&udev->cmdr_lock);
 977
 978                 *scsi_err = TCM_OUT_OF_RESOURCES;
 979                 return -1;
 980         }
 981         entry->hdr.cmd_id = tcmu_cmd->cmd_id;
 982
 983         /*
 984          * Recalaulate the command's base size and size according
 985          * to the actual needs
 986          */
 987         base_command_size = tcmu_cmd_get_base_cmd_size(entry->req.iov_cnt +
 988                                                        entry->req.iov_bidi_cnt);
 989         command_size = tcmu_cmd_get_cmd_size(tcmu_cmd, base_command_size);
 990
 991         tcmu_hdr_set_len(&entry->hdr.len_op, command_size);
 992
 993         /* All offsets relative to mb_addr, not start of entry! */
 994         cdb_off = CMDR_OFF + cmd_head + base_command_size;
 995         memcpy((void *) mb + cdb_off, se_cmd->t_task_cdb, scsi_command_size(se_cmd->t_task_cdb));
 996         entry->req.cdb_off = cdb_off;
 997         tcmu_flush_dcache_range(entry, sizeof(*entry));
 998
 999         UPDATE_HEAD(mb->cmd_head, command_size, udev->cmdr_size);
1000         tcmu_flush_dcache_range(mb, sizeof(*mb));
1001
1002         /* TODO: only if FLUSH and FUA? */
1003         uio_event_notify(&udev->uio_info);
1004
1005         return 0;
1006
1007 queue:
1008         if (add_to_cmdr_queue(tcmu_cmd)) {
1009                 *scsi_err = TCM_OUT_OF_RESOURCES;
1010                 return -1;
1011         }
1012
1013         return 1;
1014 }
1015
1016 static sense_reason_t
1017 tcmu_queue_cmd(struct se_cmd *se_cmd)
1018 {
1019         struct se_device *se_dev = se_cmd->se_dev;
1020         struct tcmu_dev *udev = TCMU_DEV(se_dev);
1021         struct tcmu_cmd *tcmu_cmd;
1022         sense_reason_t scsi_ret;
1023         int ret;
1024
1025         tcmu_cmd = tcmu_alloc_cmd(se_cmd);
1026         if (!tcmu_cmd)
1027                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1028
1029         mutex_lock(&udev->cmdr_lock);
1030         ret = queue_cmd_ring(tcmu_cmd, &scsi_ret);
1031         mutex_unlock(&udev->cmdr_lock);
1032         if (ret < 0)
1033                 tcmu_free_cmd(tcmu_cmd);
1034         return scsi_ret;
1035 }
1036
1037 static void tcmu_handle_completion(struct tcmu_cmd *cmd, struct tcmu_cmd_entry *entry)
1038 {
1039         struct se_cmd *se_cmd = cmd->se_cmd;
1040         struct tcmu_dev *udev = cmd->tcmu_dev;
1041
1042         /*
1043          * cmd has been completed already from timeout, just reclaim
1044          * data area space and free cmd
1045          */
1046         if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags))
1047                 goto out;
1048
1049         tcmu_cmd_reset_dbi_cur(cmd);
1050
1051         if (entry->hdr.uflags & TCMU_UFLAG_UNKNOWN_OP) {
1052                 pr_warn("TCMU: Userspace set UNKNOWN_OP flag on se_cmd %p\n",
1053                         cmd->se_cmd);
1054                 entry->rsp.scsi_status = SAM_STAT_CHECK_CONDITION;
1055         } else if (entry->rsp.scsi_status == SAM_STAT_CHECK_CONDITION) {
1056                 transport_copy_sense_to_cmd(se_cmd, entry->rsp.sense_buffer);
1057         } else if (se_cmd->se_cmd_flags & SCF_BIDI) {
1058                 /* Get Data-In buffer before clean up */
1059                 gather_data_area(udev, cmd, true);
1060         } else if (se_cmd->data_direction == DMA_FROM_DEVICE) {
1061                 gather_data_area(udev, cmd, false);
1062         } else if (se_cmd->data_direction == DMA_TO_DEVICE) {
1063                 /* TODO: */
1064         } else if (se_cmd->data_direction != DMA_NONE) {
1065                 pr_warn("TCMU: data direction was %d!\n",
1066                         se_cmd->data_direction);
1067         }
1068
1069         target_complete_cmd(cmd->se_cmd, entry->rsp.scsi_status);
1070
1071 out:
1072         cmd->se_cmd = NULL;
1073         tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
1074         tcmu_free_cmd(cmd);
1075 }
1076
1077 static unsigned int tcmu_handle_completions(struct tcmu_dev *udev)
1078 {
1079         struct tcmu_mailbox *mb;
1080         int handled = 0;
1081
1082         if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) {
1083                 pr_err("ring broken, not handling completions\n");
1084                 return 0;
1085         }
1086
1087         mb = udev->mb_addr;
1088         tcmu_flush_dcache_range(mb, sizeof(*mb));
1089
1090         while (udev->cmdr_last_cleaned != READ_ONCE(mb->cmd_tail)) {
1091
1092                 struct tcmu_cmd_entry *entry = (void *) mb + CMDR_OFF + udev->cmdr_last_cleaned;
1093                 struct tcmu_cmd *cmd;
1094
1095                 tcmu_flush_dcache_range(entry, sizeof(*entry));
1096
1097                 if (tcmu_hdr_get_op(entry->hdr.len_op) == TCMU_OP_PAD) {
1098                         UPDATE_HEAD(udev->cmdr_last_cleaned,
1099                                     tcmu_hdr_get_len(entry->hdr.len_op),
1100                                     udev->cmdr_size);
1101                         continue;
1102                 }
1103                 WARN_ON(tcmu_hdr_get_op(entry->hdr.len_op) != TCMU_OP_CMD);
1104
1105                 cmd = idr_remove(&udev->commands, entry->hdr.cmd_id);
1106                 if (!cmd) {
1107                         pr_err("cmd_id %u not found, ring is broken\n",
1108                                entry->hdr.cmd_id);
1109                         set_bit(TCMU_DEV_BIT_BROKEN, &udev->flags);
1110                         break;
1111                 }
1112
1113                 tcmu_handle_completion(cmd, entry);
1114
1115                 UPDATE_HEAD(udev->cmdr_last_cleaned,
1116                             tcmu_hdr_get_len(entry->hdr.len_op),
1117                             udev->cmdr_size);
1118
1119                 handled++;
1120         }
1121
1122         if (mb->cmd_tail == mb->cmd_head) {
1123                 /* no more pending commands */
1124                 del_timer(&udev->cmd_timer);
1125
1126                 if (list_empty(&udev->cmdr_queue)) {
1127                         /*
1128                          * no more pending or waiting commands so try to
1129                          * reclaim blocks if needed.
1130                          */
1131                         if (atomic_read(&global_db_count) >
1132                             tcmu_global_max_blocks)
1133                                 schedule_delayed_work(&tcmu_unmap_work, 0);
1134                 }
1135         }
1136
1137         return handled;
1138 }
1139
1140 static int tcmu_check_expired_cmd(int id, void *p, void *data)
1141 {
1142         struct tcmu_cmd *cmd = p;
1143         struct tcmu_dev *udev = cmd->tcmu_dev;
1144         u8 scsi_status;
1145         struct se_cmd *se_cmd;
1146         bool is_running;
1147
1148         if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags))
1149                 return 0;
1150
1151         if (!time_after(jiffies, cmd->deadline))
1152                 return 0;
1153
1154         is_running = list_empty(&cmd->cmdr_queue_entry);
1155         se_cmd = cmd->se_cmd;
1156
1157         if (is_running) {
1158                 /*
1159                  * If cmd_time_out is disabled but qfull is set deadline
1160                  * will only reflect the qfull timeout. Ignore it.
1161                  */
1162                 if (!udev->cmd_time_out)
1163                         return 0;
1164
1165                 set_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags);
1166                 /*
1167                  * target_complete_cmd will translate this to LUN COMM FAILURE
1168                  */
1169                 scsi_status = SAM_STAT_CHECK_CONDITION;
1170         } else {
1171                 list_del_init(&cmd->cmdr_queue_entry);
1172
1173                 idr_remove(&udev->commands, id);
1174                 tcmu_free_cmd(cmd);
1175                 scsi_status = SAM_STAT_TASK_SET_FULL;
1176         }
1177
1178         pr_debug("Timing out cmd %u on dev %s that is %s.\n",
1179                  id, udev->name, is_running ? "inflight" : "queued");
1180
1181         target_complete_cmd(se_cmd, scsi_status);
1182         return 0;
1183 }
1184
1185 static void tcmu_device_timedout(struct tcmu_dev *udev)
1186 {
1187         spin_lock(&timed_out_udevs_lock);
1188         if (list_empty(&udev->timedout_entry))
1189                 list_add_tail(&udev->timedout_entry, &timed_out_udevs);
1190         spin_unlock(&timed_out_udevs_lock);
1191
1192         schedule_delayed_work(&tcmu_unmap_work, 0);
1193 }
1194
1195 static void tcmu_cmd_timedout(struct timer_list *t)
1196 {
1197         struct tcmu_dev *udev = from_timer(udev, t, cmd_timer);
1198
1199         pr_debug("%s cmd timeout has expired\n", udev->name);
1200         tcmu_device_timedout(udev);
1201 }
1202
1203 static void tcmu_qfull_timedout(struct timer_list *t)
1204 {
1205         struct tcmu_dev *udev = from_timer(udev, t, qfull_timer);
1206
1207         pr_debug("%s qfull timeout has expired\n", udev->name);
1208         tcmu_device_timedout(udev);
1209 }
1210
1211 static int tcmu_attach_hba(struct se_hba *hba, u32 host_id)
1212 {
1213         struct tcmu_hba *tcmu_hba;
1214
1215         tcmu_hba = kzalloc(sizeof(struct tcmu_hba), GFP_KERNEL);
1216         if (!tcmu_hba)
1217                 return -ENOMEM;
1218
1219         tcmu_hba->host_id = host_id;
1220         hba->hba_ptr = tcmu_hba;
1221
1222         return 0;
1223 }
1224
1225 static void tcmu_detach_hba(struct se_hba *hba)
1226 {
1227         kfree(hba->hba_ptr);
1228         hba->hba_ptr = NULL;
1229 }
1230
1231 static struct se_device *tcmu_alloc_device(struct se_hba *hba, const char *name)
1232 {
1233         struct tcmu_dev *udev;
1234
1235         udev = kzalloc(sizeof(struct tcmu_dev), GFP_KERNEL);
1236         if (!udev)
1237                 return NULL;
1238         kref_init(&udev->kref);
1239
1240         udev->name = kstrdup(name, GFP_KERNEL);
1241         if (!udev->name) {
1242                 kfree(udev);
1243                 return NULL;
1244         }
1245
1246         udev->hba = hba;
1247         udev->cmd_time_out = TCMU_TIME_OUT;
1248         udev->qfull_time_out = -1;
1249
1250         udev->max_blocks = DATA_BLOCK_BITS_DEF;
1251         mutex_init(&udev->cmdr_lock);
1252
1253         INIT_LIST_HEAD(&udev->timedout_entry);
1254         INIT_LIST_HEAD(&udev->cmdr_queue);
1255         idr_init(&udev->commands);
1256
1257         timer_setup(&udev->qfull_timer, tcmu_qfull_timedout, 0);
1258         timer_setup(&udev->cmd_timer, tcmu_cmd_timedout, 0);
1259
1260         init_waitqueue_head(&udev->nl_cmd_wq);
1261         spin_lock_init(&udev->nl_cmd_lock);
1262
1263         INIT_RADIX_TREE(&udev->data_blocks, GFP_KERNEL);
1264
1265         return &udev->se_dev;
1266 }
1267
1268 static bool run_cmdr_queue(struct tcmu_dev *udev, bool fail)
1269 {
1270         struct tcmu_cmd *tcmu_cmd, *tmp_cmd;
1271         LIST_HEAD(cmds);
1272         bool drained = true;
1273         sense_reason_t scsi_ret;
1274         int ret;
1275
1276         if (list_empty(&udev->cmdr_queue))
1277                 return true;
1278
1279         pr_debug("running %s's cmdr queue forcefail %d\n", udev->name, fail);
1280
1281         list_splice_init(&udev->cmdr_queue, &cmds);
1282
1283         list_for_each_entry_safe(tcmu_cmd, tmp_cmd, &cmds, cmdr_queue_entry) {
1284                 list_del_init(&tcmu_cmd->cmdr_queue_entry);
1285
1286                 pr_debug("removing cmd %u on dev %s from queue\n",
1287                          tcmu_cmd->cmd_id, udev->name);
1288
1289                 if (fail) {
1290                         idr_remove(&udev->commands, tcmu_cmd->cmd_id);
1291                         /*
1292                          * We were not able to even start the command, so
1293                          * fail with busy to allow a retry in case runner
1294                          * was only temporarily down. If the device is being
1295                          * removed then LIO core will do the right thing and
1296                          * fail the retry.
1297                          */
1298                         target_complete_cmd(tcmu_cmd->se_cmd, SAM_STAT_BUSY);
1299                         tcmu_free_cmd(tcmu_cmd);
1300                         continue;
1301                 }
1302
1303                 ret = queue_cmd_ring(tcmu_cmd, &scsi_ret);
1304                 if (ret < 0) {
1305                         pr_debug("cmd %u on dev %s failed with %u\n",
1306                                  tcmu_cmd->cmd_id, udev->name, scsi_ret);
1307
1308                         idr_remove(&udev->commands, tcmu_cmd->cmd_id);
1309                         /*
1310                          * Ignore scsi_ret for now. target_complete_cmd
1311                          * drops it.
1312                          */
1313                         target_complete_cmd(tcmu_cmd->se_cmd,
1314                                             SAM_STAT_CHECK_CONDITION);
1315                         tcmu_free_cmd(tcmu_cmd);
1316                 } else if (ret > 0) {
1317                         pr_debug("ran out of space during cmdr queue run\n");
1318                         /*
1319                          * cmd was requeued, so just put all cmds back in
1320                          * the queue
1321                          */
1322                         list_splice_tail(&cmds, &udev->cmdr_queue);
1323                         drained = false;
1324                         goto done;
1325                 }
1326         }
1327         if (list_empty(&udev->cmdr_queue))
1328                 del_timer(&udev->qfull_timer);
1329 done:
1330         return drained;
1331 }
1332
1333 static int tcmu_irqcontrol(struct uio_info *info, s32 irq_on)
1334 {
1335         struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1336
1337         mutex_lock(&udev->cmdr_lock);
1338         tcmu_handle_completions(udev);
1339         run_cmdr_queue(udev, false);
1340         mutex_unlock(&udev->cmdr_lock);
1341
1342         return 0;
1343 }
1344
1345 /*
1346  * mmap code from uio.c. Copied here because we want to hook mmap()
1347  * and this stuff must come along.
1348  */
1349 static int tcmu_find_mem_index(struct vm_area_struct *vma)
1350 {
1351         struct tcmu_dev *udev = vma->vm_private_data;
1352         struct uio_info *info = &udev->uio_info;
1353
1354         if (vma->vm_pgoff < MAX_UIO_MAPS) {
1355                 if (info->mem[vma->vm_pgoff].size == 0)
1356                         return -1;
1357                 return (int)vma->vm_pgoff;
1358         }
1359         return -1;
1360 }
1361
1362 static struct page *tcmu_try_get_block_page(struct tcmu_dev *udev, uint32_t dbi)
1363 {
1364         struct page *page;
1365
1366         mutex_lock(&udev->cmdr_lock);
1367         page = tcmu_get_block_page(udev, dbi);
1368         if (likely(page)) {
1369                 mutex_unlock(&udev->cmdr_lock);
1370                 return page;
1371         }
1372
1373         /*
1374          * Userspace messed up and passed in a address not in the
1375          * data iov passed to it.
1376          */
1377         pr_err("Invalid addr to data block mapping  (dbi %u) on device %s\n",
1378                dbi, udev->name);
1379         page = NULL;
1380         mutex_unlock(&udev->cmdr_lock);
1381
1382         return page;
1383 }
1384
1385 static int tcmu_vma_fault(struct vm_fault *vmf)
1386 {
1387         struct tcmu_dev *udev = vmf->vma->vm_private_data;
1388         struct uio_info *info = &udev->uio_info;
1389         struct page *page;
1390         unsigned long offset;
1391         void *addr;
1392
1393         int mi = tcmu_find_mem_index(vmf->vma);
1394         if (mi < 0)
1395                 return VM_FAULT_SIGBUS;
1396
1397         /*
1398          * We need to subtract mi because userspace uses offset = N*PAGE_SIZE
1399          * to use mem[N].
1400          */
1401         offset = (vmf->pgoff - mi) << PAGE_SHIFT;
1402
1403         if (offset < udev->data_off) {
1404                 /* For the vmalloc()ed cmd area pages */
1405                 addr = (void *)(unsigned long)info->mem[mi].addr + offset;
1406                 page = vmalloc_to_page(addr);
1407         } else {
1408                 uint32_t dbi;
1409
1410                 /* For the dynamically growing data area pages */
1411                 dbi = (offset - udev->data_off) / DATA_BLOCK_SIZE;
1412                 page = tcmu_try_get_block_page(udev, dbi);
1413                 if (!page)
1414                         return VM_FAULT_SIGBUS;
1415         }
1416
1417         get_page(page);
1418         vmf->page = page;
1419         return 0;
1420 }
1421
1422 static const struct vm_operations_struct tcmu_vm_ops = {
1423         .fault = tcmu_vma_fault,
1424 };
1425
1426 static int tcmu_mmap(struct uio_info *info, struct vm_area_struct *vma)
1427 {
1428         struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1429
1430         vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
1431         vma->vm_ops = &tcmu_vm_ops;
1432
1433         vma->vm_private_data = udev;
1434
1435         /* Ensure the mmap is exactly the right size */
1436         if (vma_pages(vma) != (udev->ring_size >> PAGE_SHIFT))
1437                 return -EINVAL;
1438
1439         return 0;
1440 }
1441
1442 static int tcmu_open(struct uio_info *info, struct inode *inode)
1443 {
1444         struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1445
1446         /* O_EXCL not supported for char devs, so fake it? */
1447         if (test_and_set_bit(TCMU_DEV_BIT_OPEN, &udev->flags))
1448                 return -EBUSY;
1449
1450         udev->inode = inode;
1451         kref_get(&udev->kref);
1452
1453         pr_debug("open\n");
1454
1455         return 0;
1456 }
1457
1458 static void tcmu_dev_call_rcu(struct rcu_head *p)
1459 {
1460         struct se_device *dev = container_of(p, struct se_device, rcu_head);
1461         struct tcmu_dev *udev = TCMU_DEV(dev);
1462
1463         kfree(udev->uio_info.name);
1464         kfree(udev->name);
1465         kfree(udev);
1466 }
1467
1468 static int tcmu_check_and_free_pending_cmd(struct tcmu_cmd *cmd)
1469 {
1470         if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) {
1471                 kmem_cache_free(tcmu_cmd_cache, cmd);
1472                 return 0;
1473         }
1474         return -EINVAL;
1475 }
1476
1477 static void tcmu_blocks_release(struct radix_tree_root *blocks,
1478                                 int start, int end)
1479 {
1480         int i;
1481         struct page *page;
1482
1483         for (i = start; i < end; i++) {
1484                 page = radix_tree_delete(blocks, i);
1485                 if (page) {
1486                         __free_page(page);
1487                         atomic_dec(&global_db_count);
1488                 }
1489         }
1490 }
1491
1492 static void tcmu_dev_kref_release(struct kref *kref)
1493 {
1494         struct tcmu_dev *udev = container_of(kref, struct tcmu_dev, kref);
1495         struct se_device *dev = &udev->se_dev;
1496         struct tcmu_cmd *cmd;
1497         bool all_expired = true;
1498         int i;
1499
1500         vfree(udev->mb_addr);
1501         udev->mb_addr = NULL;
1502
1503         spin_lock_bh(&timed_out_udevs_lock);
1504         if (!list_empty(&udev->timedout_entry))
1505                 list_del(&udev->timedout_entry);
1506         spin_unlock_bh(&timed_out_udevs_lock);
1507
1508         /* Upper layer should drain all requests before calling this */
1509         mutex_lock(&udev->cmdr_lock);
1510         idr_for_each_entry(&udev->commands, cmd, i) {
1511                 if (tcmu_check_and_free_pending_cmd(cmd) != 0)
1512                         all_expired = false;
1513         }
1514         idr_destroy(&udev->commands);
1515         WARN_ON(!all_expired);
1516
1517         tcmu_blocks_release(&udev->data_blocks, 0, udev->dbi_max + 1);
1518         kfree(udev->data_bitmap);
1519         mutex_unlock(&udev->cmdr_lock);
1520
1521         call_rcu(&dev->rcu_head, tcmu_dev_call_rcu);
1522 }
1523
1524 static int tcmu_release(struct uio_info *info, struct inode *inode)
1525 {
1526         struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1527
1528         clear_bit(TCMU_DEV_BIT_OPEN, &udev->flags);
1529
1530         pr_debug("close\n");
1531         /* release ref from open */
1532         kref_put(&udev->kref, tcmu_dev_kref_release);
1533         return 0;
1534 }
1535
1536 static void tcmu_init_genl_cmd_reply(struct tcmu_dev *udev, int cmd)
1537 {
1538         struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
1539
1540         if (!tcmu_kern_cmd_reply_supported)
1541                 return;
1542
1543         if (udev->nl_reply_supported <= 0)
1544                 return;
1545
1546 relock:
1547         spin_lock(&udev->nl_cmd_lock);
1548
1549         if (nl_cmd->cmd != TCMU_CMD_UNSPEC) {
1550                 spin_unlock(&udev->nl_cmd_lock);
1551                 pr_debug("sleeping for open nl cmd\n");
1552                 wait_event(udev->nl_cmd_wq, (nl_cmd->cmd == TCMU_CMD_UNSPEC));
1553                 goto relock;
1554         }
1555
1556         memset(nl_cmd, 0, sizeof(*nl_cmd));
1557         nl_cmd->cmd = cmd;
1558         init_completion(&nl_cmd->complete);
1559
1560         spin_unlock(&udev->nl_cmd_lock);
1561 }
1562
1563 static int tcmu_wait_genl_cmd_reply(struct tcmu_dev *udev)
1564 {
1565         struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
1566         int ret;
1567         DEFINE_WAIT(__wait);
1568
1569         if (!tcmu_kern_cmd_reply_supported)
1570                 return 0;
1571
1572         if (udev->nl_reply_supported <= 0)
1573                 return 0;
1574
1575         pr_debug("sleeping for nl reply\n");
1576         wait_for_completion(&nl_cmd->complete);
1577
1578         spin_lock(&udev->nl_cmd_lock);
1579         nl_cmd->cmd = TCMU_CMD_UNSPEC;
1580         ret = nl_cmd->status;
1581         nl_cmd->status = 0;
1582         spin_unlock(&udev->nl_cmd_lock);
1583
1584         wake_up_all(&udev->nl_cmd_wq);
1585
1586         return ret;
1587 }
1588
1589 static int tcmu_netlink_event(struct tcmu_dev *udev, enum tcmu_genl_cmd cmd,
1590                               int reconfig_attr, const void *reconfig_data)
1591 {
1592         struct sk_buff *skb;
1593         void *msg_header;
1594         int ret = -ENOMEM;
1595
1596         skb = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
1597         if (!skb)
1598                 return ret;
1599
1600         msg_header = genlmsg_put(skb, 0, 0, &tcmu_genl_family, 0, cmd);
1601         if (!msg_header)
1602                 goto free_skb;
1603
1604         ret = nla_put_string(skb, TCMU_ATTR_DEVICE, udev->uio_info.name);
1605         if (ret < 0)
1606                 goto free_skb;
1607
1608         ret = nla_put_u32(skb, TCMU_ATTR_MINOR, udev->uio_info.uio_dev->minor);
1609         if (ret < 0)
1610                 goto free_skb;
1611
1612         ret = nla_put_u32(skb, TCMU_ATTR_DEVICE_ID, udev->se_dev.dev_index);
1613         if (ret < 0)
1614                 goto free_skb;
1615
1616         if (cmd == TCMU_CMD_RECONFIG_DEVICE) {
1617                 switch (reconfig_attr) {
1618                 case TCMU_ATTR_DEV_CFG:
1619                         ret = nla_put_string(skb, reconfig_attr, reconfig_data);
1620                         break;
1621                 case TCMU_ATTR_DEV_SIZE:
1622                         ret = nla_put_u64_64bit(skb, reconfig_attr,
1623                                                 *((u64 *)reconfig_data),
1624                                                 TCMU_ATTR_PAD);
1625                         break;
1626                 case TCMU_ATTR_WRITECACHE:
1627                         ret = nla_put_u8(skb, reconfig_attr,
1628                                           *((u8 *)reconfig_data));
1629                         break;
1630                 default:
1631                         BUG();
1632                 }
1633
1634                 if (ret < 0)
1635                         goto free_skb;
1636         }
1637
1638         genlmsg_end(skb, msg_header);
1639
1640         tcmu_init_genl_cmd_reply(udev, cmd);
1641
1642         ret = genlmsg_multicast_allns(&tcmu_genl_family, skb, 0,
1643                                 TCMU_MCGRP_CONFIG, GFP_KERNEL);
1644         /* We don't care if no one is listening */
1645         if (ret == -ESRCH)
1646                 ret = 0;
1647         if (!ret)
1648                 ret = tcmu_wait_genl_cmd_reply(udev);
1649
1650         return ret;
1651 free_skb:
1652         nlmsg_free(skb);
1653         return ret;
1654 }
1655
1656 static int tcmu_update_uio_info(struct tcmu_dev *udev)
1657 {
1658         struct tcmu_hba *hba = udev->hba->hba_ptr;
1659         struct uio_info *info;
1660         size_t size, used;
1661         char *str;
1662
1663         info = &udev->uio_info;
1664         size = snprintf(NULL, 0, "tcm-user/%u/%s/%s", hba->host_id, udev->name,
1665                         udev->dev_config);
1666         size += 1; /* for \0 */
1667         str = kmalloc(size, GFP_KERNEL);
1668         if (!str)
1669                 return -ENOMEM;
1670
1671         used = snprintf(str, size, "tcm-user/%u/%s", hba->host_id, udev->name);
1672         if (udev->dev_config[0])
1673                 snprintf(str + used, size - used, "/%s", udev->dev_config);
1674
1675         /* If the old string exists, free it */
1676         kfree(info->name);
1677         info->name = str;
1678
1679         return 0;
1680 }
1681
1682 static int tcmu_configure_device(struct se_device *dev)
1683 {
1684         struct tcmu_dev *udev = TCMU_DEV(dev);
1685         struct uio_info *info;
1686         struct tcmu_mailbox *mb;
1687         int ret = 0;
1688
1689         ret = tcmu_update_uio_info(udev);
1690         if (ret)
1691                 return ret;
1692
1693         info = &udev->uio_info;
1694
1695         udev->data_bitmap = kzalloc(BITS_TO_LONGS(udev->max_blocks) *
1696                                     sizeof(unsigned long), GFP_KERNEL);
1697         if (!udev->data_bitmap) {
1698                 ret = -ENOMEM;
1699                 goto err_bitmap_alloc;
1700         }
1701
1702         udev->mb_addr = vzalloc(CMDR_SIZE);
1703         if (!udev->mb_addr) {
1704                 ret = -ENOMEM;
1705                 goto err_vzalloc;
1706         }
1707
1708         /* mailbox fits in first part of CMDR space */
1709         udev->cmdr_size = CMDR_SIZE - CMDR_OFF;
1710         udev->data_off = CMDR_SIZE;
1711         udev->data_size = udev->max_blocks * DATA_BLOCK_SIZE;
1712         udev->dbi_thresh = 0; /* Default in Idle state */
1713
1714         /* Initialise the mailbox of the ring buffer */
1715         mb = udev->mb_addr;
1716         mb->version = TCMU_MAILBOX_VERSION;
1717         mb->flags = TCMU_MAILBOX_FLAG_CAP_OOOC;
1718         mb->cmdr_off = CMDR_OFF;
1719         mb->cmdr_size = udev->cmdr_size;
1720
1721         WARN_ON(!PAGE_ALIGNED(udev->data_off));
1722         WARN_ON(udev->data_size % PAGE_SIZE);
1723         WARN_ON(udev->data_size % DATA_BLOCK_SIZE);
1724
1725         info->version = __stringify(TCMU_MAILBOX_VERSION);
1726
1727         info->mem[0].name = "tcm-user command & data buffer";
1728         info->mem[0].addr = (phys_addr_t)(uintptr_t)udev->mb_addr;
1729         info->mem[0].size = udev->ring_size = udev->data_size + CMDR_SIZE;
1730         info->mem[0].memtype = UIO_MEM_NONE;
1731
1732         info->irqcontrol = tcmu_irqcontrol;
1733         info->irq = UIO_IRQ_CUSTOM;
1734
1735         info->mmap = tcmu_mmap;
1736         info->open = tcmu_open;
1737         info->release = tcmu_release;
1738
1739         ret = uio_register_device(tcmu_root_device, info);
1740         if (ret)
1741                 goto err_register;
1742
1743         /* User can set hw_block_size before enable the device */
1744         if (dev->dev_attrib.hw_block_size == 0)
1745                 dev->dev_attrib.hw_block_size = 512;
1746         /* Other attributes can be configured in userspace */
1747         if (!dev->dev_attrib.hw_max_sectors)
1748                 dev->dev_attrib.hw_max_sectors = 128;
1749         if (!dev->dev_attrib.emulate_write_cache)
1750                 dev->dev_attrib.emulate_write_cache = 0;
1751         dev->dev_attrib.hw_queue_depth = 128;
1752
1753         /* If user didn't explicitly disable netlink reply support, use
1754          * module scope setting.
1755          */
1756         if (udev->nl_reply_supported >= 0)
1757                 udev->nl_reply_supported = tcmu_kern_cmd_reply_supported;
1758
1759         /*
1760          * Get a ref incase userspace does a close on the uio device before
1761          * LIO has initiated tcmu_free_device.
1762          */
1763         kref_get(&udev->kref);
1764
1765         ret = tcmu_netlink_event(udev, TCMU_CMD_ADDED_DEVICE, 0, NULL);
1766         if (ret)
1767                 goto err_netlink;
1768
1769         mutex_lock(&root_udev_mutex);
1770         list_add(&udev->node, &root_udev);
1771         mutex_unlock(&root_udev_mutex);
1772
1773         return 0;
1774
1775 err_netlink:
1776         kref_put(&udev->kref, tcmu_dev_kref_release);
1777         uio_unregister_device(&udev->uio_info);
1778 err_register:
1779         vfree(udev->mb_addr);
1780         udev->mb_addr = NULL;
1781 err_vzalloc:
1782         kfree(udev->data_bitmap);
1783         udev->data_bitmap = NULL;
1784 err_bitmap_alloc:
1785         kfree(info->name);
1786         info->name = NULL;
1787
1788         return ret;
1789 }
1790
1791 static bool tcmu_dev_configured(struct tcmu_dev *udev)
1792 {
1793         return udev->uio_info.uio_dev ? true : false;
1794 }
1795
1796 static void tcmu_free_device(struct se_device *dev)
1797 {
1798         struct tcmu_dev *udev = TCMU_DEV(dev);
1799
1800         /* release ref from init */
1801         kref_put(&udev->kref, tcmu_dev_kref_release);
1802 }
1803
1804 static void tcmu_destroy_device(struct se_device *dev)
1805 {
1806         struct tcmu_dev *udev = TCMU_DEV(dev);
1807
1808         del_timer_sync(&udev->cmd_timer);
1809         del_timer_sync(&udev->qfull_timer);
1810
1811         mutex_lock(&root_udev_mutex);
1812         list_del(&udev->node);
1813         mutex_unlock(&root_udev_mutex);
1814
1815         tcmu_netlink_event(udev, TCMU_CMD_REMOVED_DEVICE, 0, NULL);
1816
1817         uio_unregister_device(&udev->uio_info);
1818
1819         /* release ref from configure */
1820         kref_put(&udev->kref, tcmu_dev_kref_release);
1821 }
1822
1823 static void tcmu_unblock_dev(struct tcmu_dev *udev)
1824 {
1825         mutex_lock(&udev->cmdr_lock);
1826         clear_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags);
1827         mutex_unlock(&udev->cmdr_lock);
1828 }
1829
1830 static void tcmu_block_dev(struct tcmu_dev *udev)
1831 {
1832         mutex_lock(&udev->cmdr_lock);
1833
1834         if (test_and_set_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags))
1835                 goto unlock;
1836
1837         /* complete IO that has executed successfully */
1838         tcmu_handle_completions(udev);
1839         /* fail IO waiting to be queued */
1840         run_cmdr_queue(udev, true);
1841
1842 unlock:
1843         mutex_unlock(&udev->cmdr_lock);
1844 }
1845
1846 static void tcmu_reset_ring(struct tcmu_dev *udev, u8 err_level)
1847 {
1848         struct tcmu_mailbox *mb;
1849         struct tcmu_cmd *cmd;
1850         int i;
1851
1852         mutex_lock(&udev->cmdr_lock);
1853
1854         idr_for_each_entry(&udev->commands, cmd, i) {
1855                 if (!list_empty(&cmd->cmdr_queue_entry))
1856                         continue;
1857
1858                 pr_debug("removing cmd %u on dev %s from ring (is expired %d)\n",
1859                           cmd->cmd_id, udev->name,
1860                           test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags));
1861
1862                 idr_remove(&udev->commands, i);
1863                 if (!test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) {
1864                         if (err_level == 1) {
1865                                 /*
1866                                  * Userspace was not able to start the
1867                                  * command or it is retryable.
1868                                  */
1869                                 target_complete_cmd(cmd->se_cmd, SAM_STAT_BUSY);
1870                         } else {
1871                                 /* hard failure */
1872                                 target_complete_cmd(cmd->se_cmd,
1873                                                     SAM_STAT_CHECK_CONDITION);
1874                         }
1875                 }
1876                 tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
1877                 tcmu_free_cmd(cmd);
1878         }
1879
1880         mb = udev->mb_addr;
1881         tcmu_flush_dcache_range(mb, sizeof(*mb));
1882         pr_debug("mb last %u head %u tail %u\n", udev->cmdr_last_cleaned,
1883                  mb->cmd_tail, mb->cmd_head);
1884
1885         udev->cmdr_last_cleaned = 0;
1886         mb->cmd_tail = 0;
1887         mb->cmd_head = 0;
1888         tcmu_flush_dcache_range(mb, sizeof(*mb));
1889
1890         del_timer(&udev->cmd_timer);
1891
1892         mutex_unlock(&udev->cmdr_lock);
1893 }
1894
1895 enum {
1896         Opt_dev_config, Opt_dev_size, Opt_hw_block_size, Opt_hw_max_sectors,
1897         Opt_nl_reply_supported, Opt_max_data_area_mb, Opt_err,
1898 };
1899
1900 static match_table_t tokens = {
1901         {Opt_dev_config, "dev_config=%s"},
1902         {Opt_dev_size, "dev_size=%u"},
1903         {Opt_hw_block_size, "hw_block_size=%u"},
1904         {Opt_hw_max_sectors, "hw_max_sectors=%u"},
1905         {Opt_nl_reply_supported, "nl_reply_supported=%d"},
1906         {Opt_max_data_area_mb, "max_data_area_mb=%u"},
1907         {Opt_err, NULL}
1908 };
1909
1910 static int tcmu_set_dev_attrib(substring_t *arg, u32 *dev_attrib)
1911 {
1912         unsigned long tmp_ul;
1913         char *arg_p;
1914         int ret;
1915
1916         arg_p = match_strdup(arg);
1917         if (!arg_p)
1918                 return -ENOMEM;
1919
1920         ret = kstrtoul(arg_p, 0, &tmp_ul);
1921         kfree(arg_p);
1922         if (ret < 0) {
1923                 pr_err("kstrtoul() failed for dev attrib\n");
1924                 return ret;
1925         }
1926         if (!tmp_ul) {
1927                 pr_err("dev attrib must be nonzero\n");
1928                 return -EINVAL;
1929         }
1930         *dev_attrib = tmp_ul;
1931         return 0;
1932 }
1933
1934 static ssize_t tcmu_set_configfs_dev_params(struct se_device *dev,
1935                 const char *page, ssize_t count)
1936 {
1937         struct tcmu_dev *udev = TCMU_DEV(dev);
1938         char *orig, *ptr, *opts, *arg_p;
1939         substring_t args[MAX_OPT_ARGS];
1940         int ret = 0, token, tmpval;
1941
1942         opts = kstrdup(page, GFP_KERNEL);
1943         if (!opts)
1944                 return -ENOMEM;
1945
1946         orig = opts;
1947
1948         while ((ptr = strsep(&opts, ",\n")) != NULL) {
1949                 if (!*ptr)
1950                         continue;
1951
1952                 token = match_token(ptr, tokens, args);
1953                 switch (token) {
1954                 case Opt_dev_config:
1955                         if (match_strlcpy(udev->dev_config, &args[0],
1956                                           TCMU_CONFIG_LEN) == 0) {
1957                                 ret = -EINVAL;
1958                                 break;
1959                         }
1960                         pr_debug("TCMU: Referencing Path: %s\n", udev->dev_config);
1961                         break;
1962                 case Opt_dev_size:
1963                         arg_p = match_strdup(&args[0]);
1964                         if (!arg_p) {
1965                                 ret = -ENOMEM;
1966                                 break;
1967                         }
1968                         ret = kstrtoul(arg_p, 0, (unsigned long *) &udev->dev_size);
1969                         kfree(arg_p);
1970                         if (ret < 0)
1971                                 pr_err("kstrtoul() failed for dev_size=\n");
1972                         break;
1973                 case Opt_hw_block_size:
1974                         ret = tcmu_set_dev_attrib(&args[0],
1975                                         &(dev->dev_attrib.hw_block_size));
1976                         break;
1977                 case Opt_hw_max_sectors:
1978                         ret = tcmu_set_dev_attrib(&args[0],
1979                                         &(dev->dev_attrib.hw_max_sectors));
1980                         break;
1981                 case Opt_nl_reply_supported:
1982                         arg_p = match_strdup(&args[0]);
1983                         if (!arg_p) {
1984                                 ret = -ENOMEM;
1985                                 break;
1986                         }
1987                         ret = kstrtoint(arg_p, 0, &udev->nl_reply_supported);
1988                         kfree(arg_p);
1989                         if (ret < 0)
1990                                 pr_err("kstrtoint() failed for nl_reply_supported=\n");
1991                         break;
1992                 case Opt_max_data_area_mb:
1993                         if (dev->export_count) {
1994                                 pr_err("Unable to set max_data_area_mb while exports exist\n");
1995                                 ret = -EINVAL;
1996                                 break;
1997                         }
1998
1999                         arg_p = match_strdup(&args[0]);
2000                         if (!arg_p) {
2001                                 ret = -ENOMEM;
2002                                 break;
2003                         }
2004                         ret = kstrtoint(arg_p, 0, &tmpval);
2005                         kfree(arg_p);
2006                         if (ret < 0) {
2007                                 pr_err("kstrtoint() failed for max_data_area_mb=\n");
2008                                 break;
2009                         }
2010
2011                         if (tmpval <= 0) {
2012                                 pr_err("Invalid max_data_area %d\n", tmpval);
2013                                 ret = -EINVAL;
2014                                 break;
2015                         }
2016
2017                         udev->max_blocks = TCMU_MBS_TO_BLOCKS(tmpval);
2018                         if (udev->max_blocks > tcmu_global_max_blocks) {
2019                                 pr_err("%d is too large. Adjusting max_data_area_mb to global limit of %u\n",
2020                                        tmpval,
2021                                        TCMU_BLOCKS_TO_MBS(tcmu_global_max_blocks));
2022                                 udev->max_blocks = tcmu_global_max_blocks;
2023                         }
2024                         break;
2025                 default:
2026                         break;
2027                 }
2028
2029                 if (ret)
2030                         break;
2031         }
2032
2033         kfree(orig);
2034         return (!ret) ? count : ret;
2035 }
2036
2037 static ssize_t tcmu_show_configfs_dev_params(struct se_device *dev, char *b)
2038 {
2039         struct tcmu_dev *udev = TCMU_DEV(dev);
2040         ssize_t bl = 0;
2041
2042         bl = sprintf(b + bl, "Config: %s ",
2043                      udev->dev_config[0] ? udev->dev_config : "NULL");
2044         bl += sprintf(b + bl, "Size: %zu ", udev->dev_size);
2045         bl += sprintf(b + bl, "MaxDataAreaMB: %u\n",
2046                       TCMU_BLOCKS_TO_MBS(udev->max_blocks));
2047
2048         return bl;
2049 }
2050
2051 static sector_t tcmu_get_blocks(struct se_device *dev)
2052 {
2053         struct tcmu_dev *udev = TCMU_DEV(dev);
2054
2055         return div_u64(udev->dev_size - dev->dev_attrib.block_size,
2056                        dev->dev_attrib.block_size);
2057 }
2058
2059 static sense_reason_t
2060 tcmu_parse_cdb(struct se_cmd *cmd)
2061 {
2062         return passthrough_parse_cdb(cmd, tcmu_queue_cmd);
2063 }
2064
2065 static ssize_t tcmu_cmd_time_out_show(struct config_item *item, char *page)
2066 {
2067         struct se_dev_attrib *da = container_of(to_config_group(item),
2068                                         struct se_dev_attrib, da_group);
2069         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2070
2071         return snprintf(page, PAGE_SIZE, "%lu\n", udev->cmd_time_out / MSEC_PER_SEC);
2072 }
2073
2074 static ssize_t tcmu_cmd_time_out_store(struct config_item *item, const char *page,
2075                                        size_t count)
2076 {
2077         struct se_dev_attrib *da = container_of(to_config_group(item),
2078                                         struct se_dev_attrib, da_group);
2079         struct tcmu_dev *udev = container_of(da->da_dev,
2080                                         struct tcmu_dev, se_dev);
2081         u32 val;
2082         int ret;
2083
2084         if (da->da_dev->export_count) {
2085                 pr_err("Unable to set tcmu cmd_time_out while exports exist\n");
2086                 return -EINVAL;
2087         }
2088
2089         ret = kstrtou32(page, 0, &val);
2090         if (ret < 0)
2091                 return ret;
2092
2093         udev->cmd_time_out = val * MSEC_PER_SEC;
2094         return count;
2095 }
2096 CONFIGFS_ATTR(tcmu_, cmd_time_out);
2097
2098 static ssize_t tcmu_qfull_time_out_show(struct config_item *item, char *page)
2099 {
2100         struct se_dev_attrib *da = container_of(to_config_group(item),
2101                                                 struct se_dev_attrib, da_group);
2102         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2103
2104         return snprintf(page, PAGE_SIZE, "%ld\n", udev->qfull_time_out <= 0 ?
2105                         udev->qfull_time_out :
2106                         udev->qfull_time_out / MSEC_PER_SEC);
2107 }
2108
2109 static ssize_t tcmu_qfull_time_out_store(struct config_item *item,
2110                                          const char *page, size_t count)
2111 {
2112         struct se_dev_attrib *da = container_of(to_config_group(item),
2113                                         struct se_dev_attrib, da_group);
2114         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2115         s32 val;
2116         int ret;
2117
2118         ret = kstrtos32(page, 0, &val);
2119         if (ret < 0)
2120                 return ret;
2121
2122         if (val >= 0) {
2123                 udev->qfull_time_out = val * MSEC_PER_SEC;
2124         } else {
2125                 printk(KERN_ERR "Invalid qfull timeout value %d\n", val);
2126                 return -EINVAL;
2127         }
2128         return count;
2129 }
2130 CONFIGFS_ATTR(tcmu_, qfull_time_out);
2131
2132 static ssize_t tcmu_max_data_area_mb_show(struct config_item *item, char *page)
2133 {
2134         struct se_dev_attrib *da = container_of(to_config_group(item),
2135                                                 struct se_dev_attrib, da_group);
2136         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2137
2138         return snprintf(page, PAGE_SIZE, "%u\n",
2139                         TCMU_BLOCKS_TO_MBS(udev->max_blocks));
2140 }
2141 CONFIGFS_ATTR_RO(tcmu_, max_data_area_mb);
2142
2143 static ssize_t tcmu_dev_config_show(struct config_item *item, char *page)
2144 {
2145         struct se_dev_attrib *da = container_of(to_config_group(item),
2146                                                 struct se_dev_attrib, da_group);
2147         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2148
2149         return snprintf(page, PAGE_SIZE, "%s\n", udev->dev_config);
2150 }
2151
2152 static ssize_t tcmu_dev_config_store(struct config_item *item, const char *page,
2153                                      size_t count)
2154 {
2155         struct se_dev_attrib *da = container_of(to_config_group(item),
2156                                                 struct se_dev_attrib, da_group);
2157         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2158         int ret, len;
2159
2160         len = strlen(page);
2161         if (!len || len > TCMU_CONFIG_LEN - 1)
2162                 return -EINVAL;
2163
2164         /* Check if device has been configured before */
2165         if (tcmu_dev_configured(udev)) {
2166                 ret = tcmu_netlink_event(udev, TCMU_CMD_RECONFIG_DEVICE,
2167                                          TCMU_ATTR_DEV_CFG, page);
2168                 if (ret) {
2169                         pr_err("Unable to reconfigure device\n");
2170                         return ret;
2171                 }
2172                 strlcpy(udev->dev_config, page, TCMU_CONFIG_LEN);
2173
2174                 ret = tcmu_update_uio_info(udev);
2175                 if (ret)
2176                         return ret;
2177                 return count;
2178         }
2179         strlcpy(udev->dev_config, page, TCMU_CONFIG_LEN);
2180
2181         return count;
2182 }
2183 CONFIGFS_ATTR(tcmu_, dev_config);
2184
2185 static ssize_t tcmu_dev_size_show(struct config_item *item, char *page)
2186 {
2187         struct se_dev_attrib *da = container_of(to_config_group(item),
2188                                                 struct se_dev_attrib, da_group);
2189         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2190
2191         return snprintf(page, PAGE_SIZE, "%zu\n", udev->dev_size);
2192 }
2193
2194 static ssize_t tcmu_dev_size_store(struct config_item *item, const char *page,
2195                                    size_t count)
2196 {
2197         struct se_dev_attrib *da = container_of(to_config_group(item),
2198                                                 struct se_dev_attrib, da_group);
2199         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2200         u64 val;
2201         int ret;
2202
2203         ret = kstrtou64(page, 0, &val);
2204         if (ret < 0)
2205                 return ret;
2206
2207         /* Check if device has been configured before */
2208         if (tcmu_dev_configured(udev)) {
2209                 ret = tcmu_netlink_event(udev, TCMU_CMD_RECONFIG_DEVICE,
2210                                          TCMU_ATTR_DEV_SIZE, &val);
2211                 if (ret) {
2212                         pr_err("Unable to reconfigure device\n");
2213                         return ret;
2214                 }
2215         }
2216         udev->dev_size = val;
2217         return count;
2218 }
2219 CONFIGFS_ATTR(tcmu_, dev_size);
2220
2221 static ssize_t tcmu_nl_reply_supported_show(struct config_item *item,
2222                 char *page)
2223 {
2224         struct se_dev_attrib *da = container_of(to_config_group(item),
2225                                                 struct se_dev_attrib, da_group);
2226         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2227
2228         return snprintf(page, PAGE_SIZE, "%d\n", udev->nl_reply_supported);
2229 }
2230
2231 static ssize_t tcmu_nl_reply_supported_store(struct config_item *item,
2232                 const char *page, size_t count)
2233 {
2234         struct se_dev_attrib *da = container_of(to_config_group(item),
2235                                                 struct se_dev_attrib, da_group);
2236         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2237         s8 val;
2238         int ret;
2239
2240         ret = kstrtos8(page, 0, &val);
2241         if (ret < 0)
2242                 return ret;
2243
2244         udev->nl_reply_supported = val;
2245         return count;
2246 }
2247 CONFIGFS_ATTR(tcmu_, nl_reply_supported);
2248
2249 static ssize_t tcmu_emulate_write_cache_show(struct config_item *item,
2250                                              char *page)
2251 {
2252         struct se_dev_attrib *da = container_of(to_config_group(item),
2253                                         struct se_dev_attrib, da_group);
2254
2255         return snprintf(page, PAGE_SIZE, "%i\n", da->emulate_write_cache);
2256 }
2257
2258 static ssize_t tcmu_emulate_write_cache_store(struct config_item *item,
2259                                               const char *page, size_t count)
2260 {
2261         struct se_dev_attrib *da = container_of(to_config_group(item),
2262                                         struct se_dev_attrib, da_group);
2263         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2264         u8 val;
2265         int ret;
2266
2267         ret = kstrtou8(page, 0, &val);
2268         if (ret < 0)
2269                 return ret;
2270
2271         /* Check if device has been configured before */
2272         if (tcmu_dev_configured(udev)) {
2273                 ret = tcmu_netlink_event(udev, TCMU_CMD_RECONFIG_DEVICE,
2274                                          TCMU_ATTR_WRITECACHE, &val);
2275                 if (ret) {
2276                         pr_err("Unable to reconfigure device\n");
2277                         return ret;
2278                 }
2279         }
2280
2281         da->emulate_write_cache = val;
2282         return count;
2283 }
2284 CONFIGFS_ATTR(tcmu_, emulate_write_cache);
2285
2286 static ssize_t tcmu_block_dev_show(struct config_item *item, char *page)
2287 {
2288         struct se_device *se_dev = container_of(to_config_group(item),
2289                                                 struct se_device,
2290                                                 dev_action_group);
2291         struct tcmu_dev *udev = TCMU_DEV(se_dev);
2292
2293         if (test_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags))
2294                 return snprintf(page, PAGE_SIZE, "%s\n", "blocked");
2295         else
2296                 return snprintf(page, PAGE_SIZE, "%s\n", "unblocked");
2297 }
2298
2299 static ssize_t tcmu_block_dev_store(struct config_item *item, const char *page,
2300                                     size_t count)
2301 {
2302         struct se_device *se_dev = container_of(to_config_group(item),
2303                                                 struct se_device,
2304                                                 dev_action_group);
2305         struct tcmu_dev *udev = TCMU_DEV(se_dev);
2306         u8 val;
2307         int ret;
2308
2309         ret = kstrtou8(page, 0, &val);
2310         if (ret < 0)
2311                 return ret;
2312
2313         if (val > 1) {
2314                 pr_err("Invalid block value %d\n", val);
2315                 return -EINVAL;
2316         }
2317
2318         if (!val)
2319                 tcmu_unblock_dev(udev);
2320         else
2321                 tcmu_block_dev(udev);
2322         return count;
2323 }
2324 CONFIGFS_ATTR(tcmu_, block_dev);
2325
2326 static ssize_t tcmu_reset_ring_store(struct config_item *item, const char *page,
2327                                      size_t count)
2328 {
2329         struct se_device *se_dev = container_of(to_config_group(item),
2330                                                 struct se_device,
2331                                                 dev_action_group);
2332         struct tcmu_dev *udev = TCMU_DEV(se_dev);
2333         u8 val;
2334         int ret;
2335
2336         ret = kstrtou8(page, 0, &val);
2337         if (ret < 0)
2338                 return ret;
2339
2340         if (val != 1 && val != 2) {
2341                 pr_err("Invalid reset ring value %d\n", val);
2342                 return -EINVAL;
2343         }
2344
2345         tcmu_reset_ring(udev, val);
2346         return count;
2347 }
2348 CONFIGFS_ATTR_WO(tcmu_, reset_ring);
2349
2350 static struct configfs_attribute *tcmu_attrib_attrs[] = {
2351         &tcmu_attr_cmd_time_out,
2352         &tcmu_attr_qfull_time_out,
2353         &tcmu_attr_max_data_area_mb,
2354         &tcmu_attr_dev_config,
2355         &tcmu_attr_dev_size,
2356         &tcmu_attr_emulate_write_cache,
2357         &tcmu_attr_nl_reply_supported,
2358         NULL,
2359 };
2360
2361 static struct configfs_attribute **tcmu_attrs;
2362
2363 static struct configfs_attribute *tcmu_action_attrs[] = {
2364         &tcmu_attr_block_dev,
2365         &tcmu_attr_reset_ring,
2366         NULL,
2367 };
2368
2369 static struct target_backend_ops tcmu_ops = {
2370         .name                   = "user",
2371         .owner                  = THIS_MODULE,
2372         .transport_flags        = TRANSPORT_FLAG_PASSTHROUGH,
2373         .attach_hba             = tcmu_attach_hba,
2374         .detach_hba             = tcmu_detach_hba,
2375         .alloc_device           = tcmu_alloc_device,
2376         .configure_device       = tcmu_configure_device,
2377         .destroy_device         = tcmu_destroy_device,
2378         .free_device            = tcmu_free_device,
2379         .parse_cdb              = tcmu_parse_cdb,
2380         .set_configfs_dev_params = tcmu_set_configfs_dev_params,
2381         .show_configfs_dev_params = tcmu_show_configfs_dev_params,
2382         .get_device_type        = sbc_get_device_type,
2383         .get_blocks             = tcmu_get_blocks,
2384         .tb_dev_action_attrs    = tcmu_action_attrs,
2385 };
2386
2387 static void find_free_blocks(void)
2388 {
2389         struct tcmu_dev *udev;
2390         loff_t off;
2391         u32 start, end, block, total_freed = 0;
2392
2393         if (atomic_read(&global_db_count) <= tcmu_global_max_blocks)
2394                 return;
2395
2396         mutex_lock(&root_udev_mutex);
2397         list_for_each_entry(udev, &root_udev, node) {
2398                 mutex_lock(&udev->cmdr_lock);
2399
2400                 /* Try to complete the finished commands first */
2401                 tcmu_handle_completions(udev);
2402
2403                 /* Skip the udevs in idle */
2404                 if (!udev->dbi_thresh) {
2405                         mutex_unlock(&udev->cmdr_lock);
2406                         continue;
2407                 }
2408
2409                 end = udev->dbi_max + 1;
2410                 block = find_last_bit(udev->data_bitmap, end);
2411                 if (block == udev->dbi_max) {
2412                         /*
2413                          * The last bit is dbi_max, so it is not possible
2414                          * reclaim any blocks.
2415                          */
2416                         mutex_unlock(&udev->cmdr_lock);
2417                         continue;
2418                 } else if (block == end) {
2419                         /* The current udev will goto idle state */
2420                         udev->dbi_thresh = start = 0;
2421                         udev->dbi_max = 0;
2422                 } else {
2423                         udev->dbi_thresh = start = block + 1;
2424                         udev->dbi_max = block;
2425                 }
2426
2427                 /* Here will truncate the data area from off */
2428                 off = udev->data_off + start * DATA_BLOCK_SIZE;
2429                 unmap_mapping_range(udev->inode->i_mapping, off, 0, 1);
2430
2431                 /* Release the block pages */
2432                 tcmu_blocks_release(&udev->data_blocks, start, end);
2433                 mutex_unlock(&udev->cmdr_lock);
2434
2435                 total_freed += end - start;
2436                 pr_debug("Freed %u blocks (total %u) from %s.\n", end - start,
2437                          total_freed, udev->name);
2438         }
2439         mutex_unlock(&root_udev_mutex);
2440
2441         if (atomic_read(&global_db_count) > tcmu_global_max_blocks)
2442                 schedule_delayed_work(&tcmu_unmap_work, msecs_to_jiffies(5000));
2443 }
2444
2445 static void check_timedout_devices(void)
2446 {
2447         struct tcmu_dev *udev, *tmp_dev;
2448         LIST_HEAD(devs);
2449
2450         spin_lock_bh(&timed_out_udevs_lock);
2451         list_splice_init(&timed_out_udevs, &devs);
2452
2453         list_for_each_entry_safe(udev, tmp_dev, &devs, timedout_entry) {
2454                 list_del_init(&udev->timedout_entry);
2455                 spin_unlock_bh(&timed_out_udevs_lock);
2456
2457                 mutex_lock(&udev->cmdr_lock);
2458                 idr_for_each(&udev->commands, tcmu_check_expired_cmd, NULL);
2459                 mutex_unlock(&udev->cmdr_lock);
2460
2461                 spin_lock_bh(&timed_out_udevs_lock);
2462         }
2463
2464         spin_unlock_bh(&timed_out_udevs_lock);
2465 }
2466
2467 static void tcmu_unmap_work_fn(struct work_struct *work)
2468 {
2469         check_timedout_devices();
2470         find_free_blocks();
2471 }
2472
2473 static int __init tcmu_module_init(void)
2474 {
2475         int ret, i, k, len = 0;
2476
2477         BUILD_BUG_ON((sizeof(struct tcmu_cmd_entry) % TCMU_OP_ALIGN_SIZE) != 0);
2478
2479         INIT_DELAYED_WORK(&tcmu_unmap_work, tcmu_unmap_work_fn);
2480
2481         tcmu_cmd_cache = kmem_cache_create("tcmu_cmd_cache",
2482                                 sizeof(struct tcmu_cmd),
2483                                 __alignof__(struct tcmu_cmd),
2484                                 0, NULL);
2485         if (!tcmu_cmd_cache)
2486                 return -ENOMEM;
2487
2488         tcmu_root_device = root_device_register("tcm_user");
2489         if (IS_ERR(tcmu_root_device)) {
2490                 ret = PTR_ERR(tcmu_root_device);
2491                 goto out_free_cache;
2492         }
2493
2494         ret = genl_register_family(&tcmu_genl_family);
2495         if (ret < 0) {
2496                 goto out_unreg_device;
2497         }
2498
2499         for (i = 0; passthrough_attrib_attrs[i] != NULL; i++) {
2500                 len += sizeof(struct configfs_attribute *);
2501         }
2502         for (i = 0; tcmu_attrib_attrs[i] != NULL; i++) {
2503                 len += sizeof(struct configfs_attribute *);
2504         }
2505         len += sizeof(struct configfs_attribute *);
2506
2507         tcmu_attrs = kzalloc(len, GFP_KERNEL);
2508         if (!tcmu_attrs) {
2509                 ret = -ENOMEM;
2510                 goto out_unreg_genl;
2511         }
2512
2513         for (i = 0; passthrough_attrib_attrs[i] != NULL; i++) {
2514                 tcmu_attrs[i] = passthrough_attrib_attrs[i];
2515         }
2516         for (k = 0; tcmu_attrib_attrs[k] != NULL; k++) {
2517                 tcmu_attrs[i] = tcmu_attrib_attrs[k];
2518                 i++;
2519         }
2520         tcmu_ops.tb_dev_attrib_attrs = tcmu_attrs;
2521
2522         ret = transport_backend_register(&tcmu_ops);
2523         if (ret)
2524                 goto out_attrs;
2525
2526         return 0;
2527
2528 out_attrs:
2529         kfree(tcmu_attrs);
2530 out_unreg_genl:
2531         genl_unregister_family(&tcmu_genl_family);
2532 out_unreg_device:
2533         root_device_unregister(tcmu_root_device);
2534 out_free_cache:
2535         kmem_cache_destroy(tcmu_cmd_cache);
2536
2537         return ret;
2538 }
2539
2540 static void __exit tcmu_module_exit(void)
2541 {
2542         cancel_delayed_work_sync(&tcmu_unmap_work);
2543         target_backend_unregister(&tcmu_ops);
2544         kfree(tcmu_attrs);
2545         genl_unregister_family(&tcmu_genl_family);
2546         root_device_unregister(tcmu_root_device);
2547         kmem_cache_destroy(tcmu_cmd_cache);
2548 }
2549
2550 MODULE_DESCRIPTION("TCM USER subsystem plugin");
2551 MODULE_AUTHOR("Shaohua Li <shli@kernel.org>");
2552 MODULE_AUTHOR("Andy Grover <agrover@redhat.com>");
2553 MODULE_LICENSE("GPL");
2554
2555 module_init(tcmu_module_init);
2556 module_exit(tcmu_module_exit);