linux/drivers/target/target_core_file.c
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   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
  44static struct se_subsystem_api fileio_template;
  45
  46/*      fd_attach_hba(): (Part of se_subsystem_api_t template)
  47 *
  48 *
  49 */
  50static 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
  74static 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
  85static 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 */
 107static 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;
 199fail:
 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 */
 211static 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
 223static 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
 276static 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
 315static 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
 361static 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
 403enum {
 404        Opt_fd_dev_name, Opt_fd_dev_size, Opt_fd_buffered_io, Opt_err
 405};
 406
 407static 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
 413static 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
 467out:
 468        kfree(orig);
 469        return (!ret) ? count : ret;
 470}
 471
 472static 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
 484static 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 */
 502static 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 */
 511static u32 fd_get_device_type(struct se_device *dev)
 512{
 513        return TYPE_DISK;
 514}
 515
 516static 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
 535static struct spc_ops fd_spc_ops = {
 536        .execute_rw             = fd_execute_rw,
 537        .execute_sync_cache     = fd_execute_sync_cache,
 538};
 539
 540static int fd_parse_cdb(struct se_cmd *cmd)
 541{
 542        return sbc_parse_cdb(cmd, &fd_spc_ops);
 543}
 544
 545static 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
 565static int __init fileio_module_init(void)
 566{
 567        return transport_subsystem_register(&fileio_template);
 568}
 569
 570static void fileio_module_exit(void)
 571{
 572        transport_subsystem_release(&fileio_template);
 573}
 574
 575MODULE_DESCRIPTION("TCM FILEIO subsystem plugin");
 576MODULE_AUTHOR("nab@Linux-iSCSI.org");
 577MODULE_LICENSE("GPL");
 578
 579module_init(fileio_module_init);
 580module_exit(fileio_module_exit);
 581
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