drivers/target/target_core_file.c

   1 /*******************************************************************************
   2  * Filename:  target_core_file.c
   3  *
   4  * This file contains the Storage Engine <-> FILEIO transport specific functions
   5  *
   6  * Copyright (c) 2005 PyX Technologies, Inc.
   7  * Copyright (c) 2005-2006 SBE, Inc.  All Rights Reserved.
   8  * Copyright (c) 2007-2010 Rising Tide Systems
   9  * Copyright (c) 2008-2010 Linux-iSCSI.org
  10  *
  11  * Nicholas A. Bellinger <nab@kernel.org>
  12  *
  13  * This program is free software; you can redistribute it and/or modify
  14  * it under the terms of the GNU General Public License as published by
  15  * the Free Software Foundation; either version 2 of the License, or
  16  * (at your option) any later version.
  17  *
  18  * This program is distributed in the hope that it will be useful,
  19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21  * GNU General Public License for more details.
  22  *
  23  * You should have received a copy of the GNU General Public License
  24  * along with this program; if not, write to the Free Software
  25  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  26  *
  27  ******************************************************************************/
  28
  29 #include <linux/string.h>
  30 #include <linux/parser.h>
  31 #include <linux/timer.h>
  32 #include <linux/blkdev.h>
  33 #include <linux/slab.h>
  34 #include <linux/spinlock.h>
  35 #include <linux/module.h>
  36 #include <scsi/scsi.h>
  37 #include <scsi/scsi_host.h>
  38
  39 #include <target/target_core_base.h>
  40 #include <target/target_core_device.h>
  41 #include <target/target_core_transport.h>
  42
  43 #include "target_core_file.h"
  44
  45 static struct se_subsystem_api fileio_template;
  46
  47 /*      fd_attach_hba(): (Part of se_subsystem_api_t template)
  48  *
  49  *
  50  */
  51 static int fd_attach_hba(struct se_hba *hba, u32 host_id)
  52 {
  53         struct fd_host *fd_host;
  54
  55         fd_host = kzalloc(sizeof(struct fd_host), GFP_KERNEL);
  56         if (!fd_host) {
  57                 pr_err("Unable to allocate memory for struct fd_host\n");
  58                 return -ENOMEM;
  59         }
  60
  61         fd_host->fd_host_id = host_id;
  62
  63         hba->hba_ptr = fd_host;
  64
  65         pr_debug("CORE_HBA[%d] - TCM FILEIO HBA Driver %s on Generic"
  66                 " Target Core Stack %s\n", hba->hba_id, FD_VERSION,
  67                 TARGET_CORE_MOD_VERSION);
  68         pr_debug("CORE_HBA[%d] - Attached FILEIO HBA: %u to Generic"
  69                 " MaxSectors: %u\n",
  70                 hba->hba_id, fd_host->fd_host_id, FD_MAX_SECTORS);
  71
  72         return 0;
  73 }
  74
  75 static void fd_detach_hba(struct se_hba *hba)
  76 {
  77         struct fd_host *fd_host = hba->hba_ptr;
  78
  79         pr_debug("CORE_HBA[%d] - Detached FILEIO HBA: %u from Generic"
  80                 " Target Core\n", hba->hba_id, fd_host->fd_host_id);
  81
  82         kfree(fd_host);
  83         hba->hba_ptr = NULL;
  84 }
  85
  86 static void *fd_allocate_virtdevice(struct se_hba *hba, const char *name)
  87 {
  88         struct fd_dev *fd_dev;
  89         struct fd_host *fd_host = (struct fd_host *) hba->hba_ptr;
  90
  91         fd_dev = kzalloc(sizeof(struct fd_dev), GFP_KERNEL);
  92         if (!fd_dev) {
  93                 pr_err("Unable to allocate memory for struct fd_dev\n");
  94                 return NULL;
  95         }
  96
  97         fd_dev->fd_host = fd_host;
  98
  99         pr_debug("FILEIO: Allocated fd_dev for %p\n", name);
 100
 101         return fd_dev;
 102 }
 103
 104 /*      fd_create_virtdevice(): (Part of se_subsystem_api_t template)
 105  *
 106  *
 107  */
 108 static struct se_device *fd_create_virtdevice(
 109         struct se_hba *hba,
 110         struct se_subsystem_dev *se_dev,
 111         void *p)
 112 {
 113         char *dev_p = NULL;
 114         struct se_device *dev;
 115         struct se_dev_limits dev_limits;
 116         struct queue_limits *limits;
 117         struct fd_dev *fd_dev = (struct fd_dev *) p;
 118         struct fd_host *fd_host = (struct fd_host *) hba->hba_ptr;
 119         mm_segment_t old_fs;
 120         struct file *file;
 121         struct inode *inode = NULL;
 122         int dev_flags = 0, flags, ret = -EINVAL;
 123
 124         memset(&dev_limits, 0, sizeof(struct se_dev_limits));
 125
 126         old_fs = get_fs();
 127         set_fs(get_ds());
 128         dev_p = getname(fd_dev->fd_dev_name);
 129         set_fs(old_fs);
 130
 131         if (IS_ERR(dev_p)) {
 132                 pr_err("getname(%s) failed: %lu\n",
 133                         fd_dev->fd_dev_name, IS_ERR(dev_p));
 134                 ret = PTR_ERR(dev_p);
 135                 goto fail;
 136         }
 137         /*
 138          * Use O_DSYNC by default instead of O_SYNC to forgo syncing
 139          * of pure timestamp updates.
 140          */
 141         flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
 142
 143         file = filp_open(dev_p, flags, 0600);
 144         if (IS_ERR(file)) {
 145                 pr_err("filp_open(%s) failed\n", dev_p);
 146                 ret = PTR_ERR(file);
 147                 goto fail;
 148         }
 149         if (!file || !file->f_dentry) {
 150                 pr_err("filp_open(%s) failed\n", dev_p);
 151                 goto fail;
 152         }
 153         fd_dev->fd_file = file;
 154         /*
 155          * If using a block backend with this struct file, we extract
 156          * fd_dev->fd_[block,dev]_size from struct block_device.
 157          *
 158          * Otherwise, we use the passed fd_size= from configfs
 159          */
 160         inode = file->f_mapping->host;
 161         if (S_ISBLK(inode->i_mode)) {
 162                 struct request_queue *q;
 163                 unsigned long long dev_size;
 164                 /*
 165                  * Setup the local scope queue_limits from struct request_queue->limits
 166                  * to pass into transport_add_device_to_core_hba() as struct se_dev_limits.
 167                  */
 168                 q = bdev_get_queue(inode->i_bdev);
 169                 limits = &dev_limits.limits;
 170                 limits->logical_block_size = bdev_logical_block_size(inode->i_bdev);
 171                 limits->max_hw_sectors = queue_max_hw_sectors(q);
 172                 limits->max_sectors = queue_max_sectors(q);
 173                 /*
 174                  * Determine the number of bytes from i_size_read() minus
 175                  * one (1) logical sector from underlying struct block_device
 176                  */
 177                 fd_dev->fd_block_size = bdev_logical_block_size(inode->i_bdev);
 178                 dev_size = (i_size_read(file->f_mapping->host) -
 179                                        fd_dev->fd_block_size);
 180
 181                 pr_debug("FILEIO: Using size: %llu bytes from struct"
 182                         " block_device blocks: %llu logical_block_size: %d\n",
 183                         dev_size, div_u64(dev_size, fd_dev->fd_block_size),
 184                         fd_dev->fd_block_size);
 185         } else {
 186                 if (!(fd_dev->fbd_flags & FBDF_HAS_SIZE)) {
 187                         pr_err("FILEIO: Missing fd_dev_size="
 188                                 " parameter, and no backing struct"
 189                                 " block_device\n");
 190                         goto fail;
 191                 }
 192
 193                 limits = &dev_limits.limits;
 194                 limits->logical_block_size = FD_BLOCKSIZE;
 195                 limits->max_hw_sectors = FD_MAX_SECTORS;
 196                 limits->max_sectors = FD_MAX_SECTORS;
 197                 fd_dev->fd_block_size = FD_BLOCKSIZE;
 198         }
 199
 200         dev_limits.hw_queue_depth = FD_MAX_DEVICE_QUEUE_DEPTH;
 201         dev_limits.queue_depth = FD_DEVICE_QUEUE_DEPTH;
 202
 203         dev = transport_add_device_to_core_hba(hba, &fileio_template,
 204                                 se_dev, dev_flags, fd_dev,
 205                                 &dev_limits, "FILEIO", FD_VERSION);
 206         if (!dev)
 207                 goto fail;
 208
 209         fd_dev->fd_dev_id = fd_host->fd_host_dev_id_count++;
 210         fd_dev->fd_queue_depth = dev->queue_depth;
 211
 212         pr_debug("CORE_FILE[%u] - Added TCM FILEIO Device ID: %u at %s,"
 213                 " %llu total bytes\n", fd_host->fd_host_id, fd_dev->fd_dev_id,
 214                         fd_dev->fd_dev_name, fd_dev->fd_dev_size);
 215
 216         putname(dev_p);
 217         return dev;
 218 fail:
 219         if (fd_dev->fd_file) {
 220                 filp_close(fd_dev->fd_file, NULL);
 221                 fd_dev->fd_file = NULL;
 222         }
 223         putname(dev_p);
 224         return ERR_PTR(ret);
 225 }
 226
 227 /*      fd_free_device(): (Part of se_subsystem_api_t template)
 228  *
 229  *
 230  */
 231 static void fd_free_device(void *p)
 232 {
 233         struct fd_dev *fd_dev = (struct fd_dev *) p;
 234
 235         if (fd_dev->fd_file) {
 236                 filp_close(fd_dev->fd_file, NULL);
 237                 fd_dev->fd_file = NULL;
 238         }
 239
 240         kfree(fd_dev);
 241 }
 242
 243 static inline struct fd_request *FILE_REQ(struct se_task *task)
 244 {
 245         return container_of(task, struct fd_request, fd_task);
 246 }
 247
 248
 249 static struct se_task *
 250 fd_alloc_task(unsigned char *cdb)
 251 {
 252         struct fd_request *fd_req;
 253
 254         fd_req = kzalloc(sizeof(struct fd_request), GFP_KERNEL);
 255         if (!fd_req) {
 256                 pr_err("Unable to allocate struct fd_request\n");
 257                 return NULL;
 258         }
 259
 260         return &fd_req->fd_task;
 261 }
 262
 263 static int fd_do_readv(struct se_task *task)
 264 {
 265         struct fd_request *req = FILE_REQ(task);
 266         struct se_device *se_dev = req->fd_task.task_se_cmd->se_dev;
 267         struct fd_dev *dev = se_dev->dev_ptr;
 268         struct file *fd = dev->fd_file;
 269         struct scatterlist *sg = task->task_sg;
 270         struct iovec *iov;
 271         mm_segment_t old_fs;
 272         loff_t pos = (task->task_lba *
 273                       se_dev->se_sub_dev->se_dev_attrib.block_size);
 274         int ret = 0, i;
 275
 276         iov = kzalloc(sizeof(struct iovec) * task->task_sg_nents, GFP_KERNEL);
 277         if (!iov) {
 278                 pr_err("Unable to allocate fd_do_readv iov[]\n");
 279                 return -ENOMEM;
 280         }
 281
 282         for_each_sg(task->task_sg, sg, task->task_sg_nents, i) {
 283                 iov[i].iov_len = sg->length;
 284                 iov[i].iov_base = sg_virt(sg);
 285         }
 286
 287         old_fs = get_fs();
 288         set_fs(get_ds());
 289         ret = vfs_readv(fd, &iov[0], task->task_sg_nents, &pos);
 290         set_fs(old_fs);
 291
 292         kfree(iov);
 293         /*
 294          * Return zeros and GOOD status even if the READ did not return
 295          * the expected virt_size for struct file w/o a backing struct
 296          * block_device.
 297          */
 298         if (S_ISBLK(fd->f_dentry->d_inode->i_mode)) {
 299                 if (ret < 0 || ret != task->task_size) {
 300                         pr_err("vfs_readv() returned %d,"
 301                                 " expecting %d for S_ISBLK\n", ret,
 302                                 (int)task->task_size);
 303                         return (ret < 0 ? ret : -EINVAL);
 304                 }
 305         } else {
 306                 if (ret < 0) {
 307                         pr_err("vfs_readv() returned %d for non"
 308                                 " S_ISBLK\n", ret);
 309                         return ret;
 310                 }
 311         }
 312
 313         return 1;
 314 }
 315
 316 static int fd_do_writev(struct se_task *task)
 317 {
 318         struct fd_request *req = FILE_REQ(task);
 319         struct se_device *se_dev = req->fd_task.task_se_cmd->se_dev;
 320         struct fd_dev *dev = se_dev->dev_ptr;
 321         struct file *fd = dev->fd_file;
 322         struct scatterlist *sg = task->task_sg;
 323         struct iovec *iov;
 324         mm_segment_t old_fs;
 325         loff_t pos = (task->task_lba *
 326                       se_dev->se_sub_dev->se_dev_attrib.block_size);
 327         int ret, i = 0;
 328
 329         iov = kzalloc(sizeof(struct iovec) * task->task_sg_nents, GFP_KERNEL);
 330         if (!iov) {
 331                 pr_err("Unable to allocate fd_do_writev iov[]\n");
 332                 return -ENOMEM;
 333         }
 334
 335         for_each_sg(task->task_sg, sg, task->task_sg_nents, i) {
 336                 iov[i].iov_len = sg->length;
 337                 iov[i].iov_base = sg_virt(sg);
 338         }
 339
 340         old_fs = get_fs();
 341         set_fs(get_ds());
 342         ret = vfs_writev(fd, &iov[0], task->task_sg_nents, &pos);
 343         set_fs(old_fs);
 344
 345         kfree(iov);
 346
 347         if (ret < 0 || ret != task->task_size) {
 348                 pr_err("vfs_writev() returned %d\n", ret);
 349                 return (ret < 0 ? ret : -EINVAL);
 350         }
 351
 352         return 1;
 353 }
 354
 355 static void fd_emulate_sync_cache(struct se_task *task)
 356 {
 357         struct se_cmd *cmd = task->task_se_cmd;
 358         struct se_device *dev = cmd->se_dev;
 359         struct fd_dev *fd_dev = dev->dev_ptr;
 360         int immed = (cmd->t_task_cdb[1] & 0x2);
 361         loff_t start, end;
 362         int ret;
 363
 364         /*
 365          * If the Immediate bit is set, queue up the GOOD response
 366          * for this SYNCHRONIZE_CACHE op
 367          */
 368         if (immed)
 369                 transport_complete_sync_cache(cmd, 1);
 370
 371         /*
 372          * Determine if we will be flushing the entire device.
 373          */
 374         if (cmd->t_task_lba == 0 && cmd->data_length == 0) {
 375                 start = 0;
 376                 end = LLONG_MAX;
 377         } else {
 378                 start = cmd->t_task_lba * dev->se_sub_dev->se_dev_attrib.block_size;
 379                 if (cmd->data_length)
 380                         end = start + cmd->data_length;
 381                 else
 382                         end = LLONG_MAX;
 383         }
 384
 385         ret = vfs_fsync_range(fd_dev->fd_file, start, end, 1);
 386         if (ret != 0)
 387                 pr_err("FILEIO: vfs_fsync_range() failed: %d\n", ret);
 388
 389         if (!immed)
 390                 transport_complete_sync_cache(cmd, ret == 0);
 391 }
 392
 393 static int fd_do_task(struct se_task *task)
 394 {
 395         struct se_cmd *cmd = task->task_se_cmd;
 396         struct se_device *dev = cmd->se_dev;
 397         int ret = 0;
 398
 399         /*
 400          * Call vectorized fileio functions to map struct scatterlist
 401          * physical memory addresses to struct iovec virtual memory.
 402          */
 403         if (task->task_data_direction == DMA_FROM_DEVICE) {
 404                 ret = fd_do_readv(task);
 405         } else {
 406                 ret = fd_do_writev(task);
 407                 /*
 408                  * Perform implict vfs_fsync_range() for fd_do_writev() ops
 409                  * for SCSI WRITEs with Forced Unit Access (FUA) set.
 410                  * Allow this to happen independent of WCE=0 setting.
 411                  */
 412                 if (ret > 0 &&
 413                     dev->se_sub_dev->se_dev_attrib.emulate_fua_write > 0 &&
 414                     (cmd->se_cmd_flags & SCF_FUA)) {
 415                         struct fd_dev *fd_dev = dev->dev_ptr;
 416                         loff_t start = task->task_lba *
 417                                 dev->se_sub_dev->se_dev_attrib.block_size;
 418                         loff_t end = start + task->task_size;
 419
 420                         vfs_fsync_range(fd_dev->fd_file, start, end, 1);
 421                 }
 422         }
 423
 424         if (ret < 0) {
 425                 cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 426                 return ret;
 427         }
 428         if (ret) {
 429                 task->task_scsi_status = GOOD;
 430                 transport_complete_task(task, 1);
 431         }
 432         return 0;
 433 }
 434
 435 /*      fd_free_task(): (Part of se_subsystem_api_t template)
 436  *
 437  *
 438  */
 439 static void fd_free_task(struct se_task *task)
 440 {
 441         struct fd_request *req = FILE_REQ(task);
 442
 443         kfree(req);
 444 }
 445
 446 enum {
 447         Opt_fd_dev_name, Opt_fd_dev_size, Opt_fd_buffered_io, Opt_err
 448 };
 449
 450 static match_table_t tokens = {
 451         {Opt_fd_dev_name, "fd_dev_name=%s"},
 452         {Opt_fd_dev_size, "fd_dev_size=%s"},
 453         {Opt_err, NULL}
 454 };
 455
 456 static ssize_t fd_set_configfs_dev_params(
 457         struct se_hba *hba,
 458         struct se_subsystem_dev *se_dev,
 459         const char *page, ssize_t count)
 460 {
 461         struct fd_dev *fd_dev = se_dev->se_dev_su_ptr;
 462         char *orig, *ptr, *arg_p, *opts;
 463         substring_t args[MAX_OPT_ARGS];
 464         int ret = 0, token;
 465
 466         opts = kstrdup(page, GFP_KERNEL);
 467         if (!opts)
 468                 return -ENOMEM;
 469
 470         orig = opts;
 471
 472         while ((ptr = strsep(&opts, ",")) != NULL) {
 473                 if (!*ptr)
 474                         continue;
 475
 476                 token = match_token(ptr, tokens, args);
 477                 switch (token) {
 478                 case Opt_fd_dev_name:
 479                         arg_p = match_strdup(&args[0]);
 480                         if (!arg_p) {
 481                                 ret = -ENOMEM;
 482                                 break;
 483                         }
 484                         snprintf(fd_dev->fd_dev_name, FD_MAX_DEV_NAME,
 485                                         "%s", arg_p);
 486                         kfree(arg_p);
 487                         pr_debug("FILEIO: Referencing Path: %s\n",
 488                                         fd_dev->fd_dev_name);
 489                         fd_dev->fbd_flags |= FBDF_HAS_PATH;
 490                         break;
 491                 case Opt_fd_dev_size:
 492                         arg_p = match_strdup(&args[0]);
 493                         if (!arg_p) {
 494                                 ret = -ENOMEM;
 495                                 break;
 496                         }
 497                         ret = strict_strtoull(arg_p, 0, &fd_dev->fd_dev_size);
 498                         kfree(arg_p);
 499                         if (ret < 0) {
 500                                 pr_err("strict_strtoull() failed for"
 501                                                 " fd_dev_size=\n");
 502                                 goto out;
 503                         }
 504                         pr_debug("FILEIO: Referencing Size: %llu"
 505                                         " bytes\n", fd_dev->fd_dev_size);
 506                         fd_dev->fbd_flags |= FBDF_HAS_SIZE;
 507                         break;
 508                 default:
 509                         break;
 510                 }
 511         }
 512
 513 out:
 514         kfree(orig);
 515         return (!ret) ? count : ret;
 516 }
 517
 518 static ssize_t fd_check_configfs_dev_params(struct se_hba *hba, struct se_subsystem_dev *se_dev)
 519 {
 520         struct fd_dev *fd_dev = (struct fd_dev *) se_dev->se_dev_su_ptr;
 521
 522         if (!(fd_dev->fbd_flags & FBDF_HAS_PATH)) {
 523                 pr_err("Missing fd_dev_name=\n");
 524                 return -EINVAL;
 525         }
 526
 527         return 0;
 528 }
 529
 530 static ssize_t fd_show_configfs_dev_params(
 531         struct se_hba *hba,
 532         struct se_subsystem_dev *se_dev,
 533         char *b)
 534 {
 535         struct fd_dev *fd_dev = se_dev->se_dev_su_ptr;
 536         ssize_t bl = 0;
 537
 538         bl = sprintf(b + bl, "TCM FILEIO ID: %u", fd_dev->fd_dev_id);
 539         bl += sprintf(b + bl, "        File: %s  Size: %llu  Mode: O_DSYNC\n",
 540                 fd_dev->fd_dev_name, fd_dev->fd_dev_size);
 541         return bl;
 542 }
 543
 544 /*      fd_get_device_rev(): (Part of se_subsystem_api_t template)
 545  *
 546  *
 547  */
 548 static u32 fd_get_device_rev(struct se_device *dev)
 549 {
 550         return SCSI_SPC_2; /* Returns SPC-3 in Initiator Data */
 551 }
 552
 553 /*      fd_get_device_type(): (Part of se_subsystem_api_t template)
 554  *
 555  *
 556  */
 557 static u32 fd_get_device_type(struct se_device *dev)
 558 {
 559         return TYPE_DISK;
 560 }
 561
 562 static sector_t fd_get_blocks(struct se_device *dev)
 563 {
 564         struct fd_dev *fd_dev = dev->dev_ptr;
 565         struct file *f = fd_dev->fd_file;
 566         struct inode *i = f->f_mapping->host;
 567         unsigned long long dev_size;
 568         /*
 569          * When using a file that references an underlying struct block_device,
 570          * ensure dev_size is always based on the current inode size in order
 571          * to handle underlying block_device resize operations.
 572          */
 573         if (S_ISBLK(i->i_mode))
 574                 dev_size = (i_size_read(i) - fd_dev->fd_block_size);
 575         else
 576                 dev_size = fd_dev->fd_dev_size;
 577
 578         return div_u64(dev_size, dev->se_sub_dev->se_dev_attrib.block_size);
 579 }
 580
 581 static struct se_subsystem_api fileio_template = {
 582         .name                   = "fileio",
 583         .owner                  = THIS_MODULE,
 584         .transport_type         = TRANSPORT_PLUGIN_VHBA_PDEV,
 585         .write_cache_emulated   = 1,
 586         .fua_write_emulated     = 1,
 587         .attach_hba             = fd_attach_hba,
 588         .detach_hba             = fd_detach_hba,
 589         .allocate_virtdevice    = fd_allocate_virtdevice,
 590         .create_virtdevice      = fd_create_virtdevice,
 591         .free_device            = fd_free_device,
 592         .alloc_task             = fd_alloc_task,
 593         .do_task                = fd_do_task,
 594         .do_sync_cache          = fd_emulate_sync_cache,
 595         .free_task              = fd_free_task,
 596         .check_configfs_dev_params = fd_check_configfs_dev_params,
 597         .set_configfs_dev_params = fd_set_configfs_dev_params,
 598         .show_configfs_dev_params = fd_show_configfs_dev_params,
 599         .get_device_rev         = fd_get_device_rev,
 600         .get_device_type        = fd_get_device_type,
 601         .get_blocks             = fd_get_blocks,
 602 };
 603
 604 static int __init fileio_module_init(void)
 605 {
 606         return transport_subsystem_register(&fileio_template);
 607 }
 608
 609 static void fileio_module_exit(void)
 610 {
 611         transport_subsystem_release(&fileio_template);
 612 }
 613
 614 MODULE_DESCRIPTION("TCM FILEIO subsystem plugin");
 615 MODULE_AUTHOR("nab@Linux-iSCSI.org");
 616 MODULE_LICENSE("GPL");
 617
 618 module_init(fileio_module_init);
 619 module_exit(fileio_module_exit);