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         char *dev_p = NULL;
 113         struct se_device *dev;
 114         struct se_dev_limits dev_limits;
 115         struct queue_limits *limits;
 116         struct fd_dev *fd_dev = p;
 117         struct fd_host *fd_host = hba->hba_ptr;
 118         mm_segment_t old_fs;
 119         struct file *file;
 120         struct inode *inode = NULL;
 121         int dev_flags = 0, flags, ret = -EINVAL;
 122
 123         memset(&dev_limits, 0, sizeof(struct se_dev_limits));
 124
 125         old_fs = get_fs();
 126         set_fs(get_ds());
 127         dev_p = getname(fd_dev->fd_dev_name);
 128         set_fs(old_fs);
 129
 130         if (IS_ERR(dev_p)) {
 131                 pr_err("getname(%s) failed: %lu\n",
 132                         fd_dev->fd_dev_name, IS_ERR(dev_p));
 133                 ret = PTR_ERR(dev_p);
 134                 goto fail;
 135         }
 136         /*
 137          * Use O_DSYNC by default instead of O_SYNC to forgo syncing
 138          * of pure timestamp updates.
 139          */
 140         flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
 141
 142         file = filp_open(dev_p, flags, 0600);
 143         if (IS_ERR(file)) {
 144                 pr_err("filp_open(%s) failed\n", dev_p);
 145                 ret = PTR_ERR(file);
 146                 goto fail;
 147         }
 148         if (!file || !file->f_dentry) {
 149                 pr_err("filp_open(%s) failed\n", dev_p);
 150                 goto fail;
 151         }
 152         fd_dev->fd_file = file;
 153         /*
 154          * If using a block backend with this struct file, we extract
 155          * fd_dev->fd_[block,dev]_size from struct block_device.
 156          *
 157          * Otherwise, we use the passed fd_size= from configfs
 158          */
 159         inode = file->f_mapping->host;
 160         if (S_ISBLK(inode->i_mode)) {
 161                 struct request_queue *q;
 162                 unsigned long long dev_size;
 163                 /*
 164                  * Setup the local scope queue_limits from struct request_queue->limits
 165                  * to pass into transport_add_device_to_core_hba() as struct se_dev_limits.
 166                  */
 167                 q = bdev_get_queue(inode->i_bdev);
 168                 limits = &dev_limits.limits;
 169                 limits->logical_block_size = bdev_logical_block_size(inode->i_bdev);
 170                 limits->max_hw_sectors = queue_max_hw_sectors(q);
 171                 limits->max_sectors = queue_max_sectors(q);
 172                 /*
 173                  * Determine the number of bytes from i_size_read() minus
 174                  * one (1) logical sector from underlying struct block_device
 175                  */
 176                 fd_dev->fd_block_size = bdev_logical_block_size(inode->i_bdev);
 177                 dev_size = (i_size_read(file->f_mapping->host) -
 178                                        fd_dev->fd_block_size);
 179
 180                 pr_debug("FILEIO: Using size: %llu bytes from struct"
 181                         " block_device blocks: %llu logical_block_size: %d\n",
 182                         dev_size, div_u64(dev_size, fd_dev->fd_block_size),
 183                         fd_dev->fd_block_size);
 184         } else {
 185                 if (!(fd_dev->fbd_flags & FBDF_HAS_SIZE)) {
 186                         pr_err("FILEIO: Missing fd_dev_size="
 187                                 " parameter, and no backing struct"
 188                                 " block_device\n");
 189                         goto fail;
 190                 }
 191
 192                 limits = &dev_limits.limits;
 193                 limits->logical_block_size = FD_BLOCKSIZE;
 194                 limits->max_hw_sectors = FD_MAX_SECTORS;
 195                 limits->max_sectors = FD_MAX_SECTORS;
 196                 fd_dev->fd_block_size = FD_BLOCKSIZE;
 197         }
 198
 199         dev_limits.hw_queue_depth = FD_MAX_DEVICE_QUEUE_DEPTH;
 200         dev_limits.queue_depth = FD_DEVICE_QUEUE_DEPTH;
 201
 202         dev = transport_add_device_to_core_hba(hba, &fileio_template,
 203                                 se_dev, dev_flags, fd_dev,
 204                                 &dev_limits, "FILEIO", FD_VERSION);
 205         if (!dev)
 206                 goto fail;
 207
 208         fd_dev->fd_dev_id = fd_host->fd_host_dev_id_count++;
 209         fd_dev->fd_queue_depth = dev->queue_depth;
 210
 211         pr_debug("CORE_FILE[%u] - Added TCM FILEIO Device ID: %u at %s,"
 212                 " %llu total bytes\n", fd_host->fd_host_id, fd_dev->fd_dev_id,
 213                         fd_dev->fd_dev_name, fd_dev->fd_dev_size);
 214
 215         putname(dev_p);
 216         return dev;
 217 fail:
 218         if (fd_dev->fd_file) {
 219                 filp_close(fd_dev->fd_file, NULL);
 220                 fd_dev->fd_file = NULL;
 221         }
 222         putname(dev_p);
 223         return ERR_PTR(ret);
 224 }
 225
 226 /*      fd_free_device(): (Part of se_subsystem_api_t template)
 227  *
 228  *
 229  */
 230 static void fd_free_device(void *p)
 231 {
 232         struct fd_dev *fd_dev = p;
 233
 234         if (fd_dev->fd_file) {
 235                 filp_close(fd_dev->fd_file, NULL);
 236                 fd_dev->fd_file = NULL;
 237         }
 238
 239         kfree(fd_dev);
 240 }
 241
 242 static int fd_do_readv(struct se_cmd *cmd, struct scatterlist *sgl,
 243                 u32 sgl_nents)
 244 {
 245         struct se_device *se_dev = cmd->se_dev;
 246         struct fd_dev *dev = se_dev->dev_ptr;
 247         struct file *fd = dev->fd_file;
 248         struct scatterlist *sg;
 249         struct iovec *iov;
 250         mm_segment_t old_fs;
 251         loff_t pos = (cmd->t_task_lba *
 252                       se_dev->se_sub_dev->se_dev_attrib.block_size);
 253         int ret = 0, i;
 254
 255         iov = kzalloc(sizeof(struct iovec) * sgl_nents, GFP_KERNEL);
 256         if (!iov) {
 257                 pr_err("Unable to allocate fd_do_readv iov[]\n");
 258                 return -ENOMEM;
 259         }
 260
 261         for_each_sg(sgl, sg, sgl_nents, i) {
 262                 iov[i].iov_len = sg->length;
 263                 iov[i].iov_base = sg_virt(sg);
 264         }
 265
 266         old_fs = get_fs();
 267         set_fs(get_ds());
 268         ret = vfs_readv(fd, &iov[0], sgl_nents, &pos);
 269         set_fs(old_fs);
 270
 271         kfree(iov);
 272         /*
 273          * Return zeros and GOOD status even if the READ did not return
 274          * the expected virt_size for struct file w/o a backing struct
 275          * block_device.
 276          */
 277         if (S_ISBLK(fd->f_dentry->d_inode->i_mode)) {
 278                 if (ret < 0 || ret != cmd->data_length) {
 279                         pr_err("vfs_readv() returned %d,"
 280                                 " expecting %d for S_ISBLK\n", ret,
 281                                 (int)cmd->data_length);
 282                         return (ret < 0 ? ret : -EINVAL);
 283                 }
 284         } else {
 285                 if (ret < 0) {
 286                         pr_err("vfs_readv() returned %d for non"
 287                                 " S_ISBLK\n", ret);
 288                         return ret;
 289                 }
 290         }
 291
 292         return 1;
 293 }
 294
 295 static int fd_do_writev(struct se_cmd *cmd, struct scatterlist *sgl,
 296                 u32 sgl_nents)
 297 {
 298         struct se_device *se_dev = cmd->se_dev;
 299         struct fd_dev *dev = se_dev->dev_ptr;
 300         struct file *fd = dev->fd_file;
 301         struct scatterlist *sg;
 302         struct iovec *iov;
 303         mm_segment_t old_fs;
 304         loff_t pos = (cmd->t_task_lba *
 305                       se_dev->se_sub_dev->se_dev_attrib.block_size);
 306         int ret, i = 0;
 307
 308         iov = kzalloc(sizeof(struct iovec) * sgl_nents, GFP_KERNEL);
 309         if (!iov) {
 310                 pr_err("Unable to allocate fd_do_writev iov[]\n");
 311                 return -ENOMEM;
 312         }
 313
 314         for_each_sg(sgl, sg, sgl_nents, i) {
 315                 iov[i].iov_len = sg->length;
 316                 iov[i].iov_base = sg_virt(sg);
 317         }
 318
 319         old_fs = get_fs();
 320         set_fs(get_ds());
 321         ret = vfs_writev(fd, &iov[0], sgl_nents, &pos);
 322         set_fs(old_fs);
 323
 324         kfree(iov);
 325
 326         if (ret < 0 || ret != cmd->data_length) {
 327                 pr_err("vfs_writev() returned %d\n", ret);
 328                 return (ret < 0 ? ret : -EINVAL);
 329         }
 330
 331         return 1;
 332 }
 333
 334 static void fd_emulate_sync_cache(struct se_cmd *cmd)
 335 {
 336         struct se_device *dev = cmd->se_dev;
 337         struct fd_dev *fd_dev = dev->dev_ptr;
 338         int immed = (cmd->t_task_cdb[1] & 0x2);
 339         loff_t start, end;
 340         int ret;
 341
 342         /*
 343          * If the Immediate bit is set, queue up the GOOD response
 344          * for this SYNCHRONIZE_CACHE op
 345          */
 346         if (immed)
 347                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 348
 349         /*
 350          * Determine if we will be flushing the entire device.
 351          */
 352         if (cmd->t_task_lba == 0 && cmd->data_length == 0) {
 353                 start = 0;
 354                 end = LLONG_MAX;
 355         } else {
 356                 start = cmd->t_task_lba * dev->se_sub_dev->se_dev_attrib.block_size;
 357                 if (cmd->data_length)
 358                         end = start + cmd->data_length;
 359                 else
 360                         end = LLONG_MAX;
 361         }
 362
 363         ret = vfs_fsync_range(fd_dev->fd_file, start, end, 1);
 364         if (ret != 0)
 365                 pr_err("FILEIO: vfs_fsync_range() failed: %d\n", ret);
 366
 367         if (immed)
 368                 return;
 369
 370         if (ret) {
 371                 cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 372                 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
 373         } else {
 374                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 375         }
 376 }
 377
 378 static int fd_execute_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
 379                 u32 sgl_nents, enum dma_data_direction data_direction)
 380 {
 381         struct se_device *dev = cmd->se_dev;
 382         int ret = 0;
 383
 384         /*
 385          * Call vectorized fileio functions to map struct scatterlist
 386          * physical memory addresses to struct iovec virtual memory.
 387          */
 388         if (data_direction == DMA_FROM_DEVICE) {
 389                 ret = fd_do_readv(cmd, sgl, sgl_nents);
 390         } else {
 391                 ret = fd_do_writev(cmd, sgl, sgl_nents);
 392                 /*
 393                  * Perform implict vfs_fsync_range() for fd_do_writev() ops
 394                  * for SCSI WRITEs with Forced Unit Access (FUA) set.
 395                  * Allow this to happen independent of WCE=0 setting.
 396                  */
 397                 if (ret > 0 &&
 398                     dev->se_sub_dev->se_dev_attrib.emulate_fua_write > 0 &&
 399                     (cmd->se_cmd_flags & SCF_FUA)) {
 400                         struct fd_dev *fd_dev = dev->dev_ptr;
 401                         loff_t start = cmd->t_task_lba *
 402                                 dev->se_sub_dev->se_dev_attrib.block_size;
 403                         loff_t end = start + cmd->data_length;
 404
 405                         vfs_fsync_range(fd_dev->fd_file, start, end, 1);
 406                 }
 407         }
 408
 409         if (ret < 0) {
 410                 cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 411                 return ret;
 412         }
 413         if (ret)
 414                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 415         return 0;
 416 }
 417
 418 enum {
 419         Opt_fd_dev_name, Opt_fd_dev_size, Opt_fd_buffered_io, Opt_err
 420 };
 421
 422 static match_table_t tokens = {
 423         {Opt_fd_dev_name, "fd_dev_name=%s"},
 424         {Opt_fd_dev_size, "fd_dev_size=%s"},
 425         {Opt_err, NULL}
 426 };
 427
 428 static ssize_t fd_set_configfs_dev_params(
 429         struct se_hba *hba,
 430         struct se_subsystem_dev *se_dev,
 431         const char *page, ssize_t count)
 432 {
 433         struct fd_dev *fd_dev = se_dev->se_dev_su_ptr;
 434         char *orig, *ptr, *arg_p, *opts;
 435         substring_t args[MAX_OPT_ARGS];
 436         int ret = 0, token;
 437
 438         opts = kstrdup(page, GFP_KERNEL);
 439         if (!opts)
 440                 return -ENOMEM;
 441
 442         orig = opts;
 443
 444         while ((ptr = strsep(&opts, ",\n")) != NULL) {
 445                 if (!*ptr)
 446                         continue;
 447
 448                 token = match_token(ptr, tokens, args);
 449                 switch (token) {
 450                 case Opt_fd_dev_name:
 451                         arg_p = match_strdup(&args[0]);
 452                         if (!arg_p) {
 453                                 ret = -ENOMEM;
 454                                 break;
 455                         }
 456                         snprintf(fd_dev->fd_dev_name, FD_MAX_DEV_NAME,
 457                                         "%s", arg_p);
 458                         kfree(arg_p);
 459                         pr_debug("FILEIO: Referencing Path: %s\n",
 460                                         fd_dev->fd_dev_name);
 461                         fd_dev->fbd_flags |= FBDF_HAS_PATH;
 462                         break;
 463                 case Opt_fd_dev_size:
 464                         arg_p = match_strdup(&args[0]);
 465                         if (!arg_p) {
 466                                 ret = -ENOMEM;
 467                                 break;
 468                         }
 469                         ret = strict_strtoull(arg_p, 0, &fd_dev->fd_dev_size);
 470                         kfree(arg_p);
 471                         if (ret < 0) {
 472                                 pr_err("strict_strtoull() failed for"
 473                                                 " fd_dev_size=\n");
 474                                 goto out;
 475                         }
 476                         pr_debug("FILEIO: Referencing Size: %llu"
 477                                         " bytes\n", fd_dev->fd_dev_size);
 478                         fd_dev->fbd_flags |= FBDF_HAS_SIZE;
 479                         break;
 480                 default:
 481                         break;
 482                 }
 483         }
 484
 485 out:
 486         kfree(orig);
 487         return (!ret) ? count : ret;
 488 }
 489
 490 static ssize_t fd_check_configfs_dev_params(struct se_hba *hba, struct se_subsystem_dev *se_dev)
 491 {
 492         struct fd_dev *fd_dev = se_dev->se_dev_su_ptr;
 493
 494         if (!(fd_dev->fbd_flags & FBDF_HAS_PATH)) {
 495                 pr_err("Missing fd_dev_name=\n");
 496                 return -EINVAL;
 497         }
 498
 499         return 0;
 500 }
 501
 502 static ssize_t fd_show_configfs_dev_params(
 503         struct se_hba *hba,
 504         struct se_subsystem_dev *se_dev,
 505         char *b)
 506 {
 507         struct fd_dev *fd_dev = se_dev->se_dev_su_ptr;
 508         ssize_t bl = 0;
 509
 510         bl = sprintf(b + bl, "TCM FILEIO ID: %u", fd_dev->fd_dev_id);
 511         bl += sprintf(b + bl, "        File: %s  Size: %llu  Mode: O_DSYNC\n",
 512                 fd_dev->fd_dev_name, fd_dev->fd_dev_size);
 513         return bl;
 514 }
 515
 516 /*      fd_get_device_rev(): (Part of se_subsystem_api_t template)
 517  *
 518  *
 519  */
 520 static u32 fd_get_device_rev(struct se_device *dev)
 521 {
 522         return SCSI_SPC_2; /* Returns SPC-3 in Initiator Data */
 523 }
 524
 525 /*      fd_get_device_type(): (Part of se_subsystem_api_t template)
 526  *
 527  *
 528  */
 529 static u32 fd_get_device_type(struct se_device *dev)
 530 {
 531         return TYPE_DISK;
 532 }
 533
 534 static sector_t fd_get_blocks(struct se_device *dev)
 535 {
 536         struct fd_dev *fd_dev = dev->dev_ptr;
 537         struct file *f = fd_dev->fd_file;
 538         struct inode *i = f->f_mapping->host;
 539         unsigned long long dev_size;
 540         /*
 541          * When using a file that references an underlying struct block_device,
 542          * ensure dev_size is always based on the current inode size in order
 543          * to handle underlying block_device resize operations.
 544          */
 545         if (S_ISBLK(i->i_mode))
 546                 dev_size = (i_size_read(i) - fd_dev->fd_block_size);
 547         else
 548                 dev_size = fd_dev->fd_dev_size;
 549
 550         return div_u64(dev_size, dev->se_sub_dev->se_dev_attrib.block_size);
 551 }
 552
 553 static struct se_subsystem_api fileio_template = {
 554         .name                   = "fileio",
 555         .owner                  = THIS_MODULE,
 556         .transport_type         = TRANSPORT_PLUGIN_VHBA_PDEV,
 557         .write_cache_emulated   = 1,
 558         .fua_write_emulated     = 1,
 559         .attach_hba             = fd_attach_hba,
 560         .detach_hba             = fd_detach_hba,
 561         .allocate_virtdevice    = fd_allocate_virtdevice,
 562         .create_virtdevice      = fd_create_virtdevice,
 563         .free_device            = fd_free_device,
 564         .execute_cmd            = fd_execute_cmd,
 565         .do_sync_cache          = fd_emulate_sync_cache,
 566         .check_configfs_dev_params = fd_check_configfs_dev_params,
 567         .set_configfs_dev_params = fd_set_configfs_dev_params,
 568         .show_configfs_dev_params = fd_show_configfs_dev_params,
 569         .get_device_rev         = fd_get_device_rev,
 570         .get_device_type        = fd_get_device_type,
 571         .get_blocks             = fd_get_blocks,
 572 };
 573
 574 static int __init fileio_module_init(void)
 575 {
 576         return transport_subsystem_register(&fileio_template);
 577 }
 578
 579 static void fileio_module_exit(void)
 580 {
 581         transport_subsystem_release(&fileio_template);
 582 }
 583
 584 MODULE_DESCRIPTION("TCM FILEIO subsystem plugin");
 585 MODULE_AUTHOR("nab@Linux-iSCSI.org");
 586 MODULE_LICENSE("GPL");
 587
 588 module_init(fileio_module_init);
 589 module_exit(fileio_module_exit);