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