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 * (c) Copyright 2005-2012 RisingTide Systems LLC.
   7 *
   8 * Nicholas A. Bellinger <nab@kernel.org>
   9 *
  10 * This program is free software; you can redistribute it and/or modify
  11 * it under the terms of the GNU General Public License as published by
  12 * the Free Software Foundation; either version 2 of the License, or
  13 * (at your option) any later version.
  14 *
  15 * This program is distributed in the hope that it will be useful,
  16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 * GNU General Public License for more details.
  19 *
  20 * You should have received a copy of the GNU General Public License
  21 * along with this program; if not, write to the Free Software
  22 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23 *
  24 ******************************************************************************/
  25
  26#include <linux/string.h>
  27#include <linux/parser.h>
  28#include <linux/timer.h>
  29#include <linux/blkdev.h>
  30#include <linux/slab.h>
  31#include <linux/spinlock.h>
  32#include <linux/module.h>
  33#include <linux/falloc.h>
  34#include <scsi/scsi.h>
  35#include <scsi/scsi_host.h>
  36#include <asm/unaligned.h>
  37
  38#include <target/target_core_base.h>
  39#include <target/target_core_backend.h>
  40
  41#include "target_core_file.h"
  42
  43static inline struct fd_dev *FD_DEV(struct se_device *dev)
  44{
  45        return container_of(dev, struct fd_dev, dev);
  46}
  47
  48/*      fd_attach_hba(): (Part of se_subsystem_api_t template)
  49 *
  50 *
  51 */
  52static int fd_attach_hba(struct se_hba *hba, u32 host_id)
  53{
  54        struct fd_host *fd_host;
  55
  56        fd_host = kzalloc(sizeof(struct fd_host), GFP_KERNEL);
  57        if (!fd_host) {
  58                pr_err("Unable to allocate memory for struct fd_host\n");
  59                return -ENOMEM;
  60        }
  61
  62        fd_host->fd_host_id = host_id;
  63
  64        hba->hba_ptr = fd_host;
  65
  66        pr_debug("CORE_HBA[%d] - TCM FILEIO HBA Driver %s on Generic"
  67                " Target Core Stack %s\n", hba->hba_id, FD_VERSION,
  68                TARGET_CORE_MOD_VERSION);
  69        pr_debug("CORE_HBA[%d] - Attached FILEIO HBA: %u to Generic"
  70                " MaxSectors: %u\n",
  71                hba->hba_id, fd_host->fd_host_id, FD_MAX_SECTORS);
  72
  73        return 0;
  74}
  75
  76static void fd_detach_hba(struct se_hba *hba)
  77{
  78        struct fd_host *fd_host = hba->hba_ptr;
  79
  80        pr_debug("CORE_HBA[%d] - Detached FILEIO HBA: %u from Generic"
  81                " Target Core\n", hba->hba_id, fd_host->fd_host_id);
  82
  83        kfree(fd_host);
  84        hba->hba_ptr = NULL;
  85}
  86
  87static struct se_device *fd_alloc_device(struct se_hba *hba, const char *name)
  88{
  89        struct fd_dev *fd_dev;
  90        struct fd_host *fd_host = hba->hba_ptr;
  91
  92        fd_dev = kzalloc(sizeof(struct fd_dev), GFP_KERNEL);
  93        if (!fd_dev) {
  94                pr_err("Unable to allocate memory for struct fd_dev\n");
  95                return NULL;
  96        }
  97
  98        fd_dev->fd_host = fd_host;
  99
 100        pr_debug("FILEIO: Allocated fd_dev for %p\n", name);
 101
 102        return &fd_dev->dev;
 103}
 104
 105static int fd_configure_device(struct se_device *dev)
 106{
 107        struct fd_dev *fd_dev = FD_DEV(dev);
 108        struct fd_host *fd_host = dev->se_hba->hba_ptr;
 109        struct file *file;
 110        struct inode *inode = NULL;
 111        int flags, ret = -EINVAL;
 112
 113        if (!(fd_dev->fbd_flags & FBDF_HAS_PATH)) {
 114                pr_err("Missing fd_dev_name=\n");
 115                return -EINVAL;
 116        }
 117
 118        /*
 119         * Use O_DSYNC by default instead of O_SYNC to forgo syncing
 120         * of pure timestamp updates.
 121         */
 122        flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
 123
 124        /*
 125         * Optionally allow fd_buffered_io=1 to be enabled for people
 126         * who want use the fs buffer cache as an WriteCache mechanism.
 127         *
 128         * This means that in event of a hard failure, there is a risk
 129         * of silent data-loss if the SCSI client has *not* performed a
 130         * forced unit access (FUA) write, or issued SYNCHRONIZE_CACHE
 131         * to write-out the entire device cache.
 132         */
 133        if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
 134                pr_debug("FILEIO: Disabling O_DSYNC, using buffered FILEIO\n");
 135                flags &= ~O_DSYNC;
 136        }
 137
 138        file = filp_open(fd_dev->fd_dev_name, flags, 0600);
 139        if (IS_ERR(file)) {
 140                pr_err("filp_open(%s) failed\n", fd_dev->fd_dev_name);
 141                ret = PTR_ERR(file);
 142                goto fail;
 143        }
 144        fd_dev->fd_file = file;
 145        /*
 146         * If using a block backend with this struct file, we extract
 147         * fd_dev->fd_[block,dev]_size from struct block_device.
 148         *
 149         * Otherwise, we use the passed fd_size= from configfs
 150         */
 151        inode = file->f_mapping->host;
 152        if (S_ISBLK(inode->i_mode)) {
 153                struct request_queue *q = bdev_get_queue(inode->i_bdev);
 154                unsigned long long dev_size;
 155
 156                fd_dev->fd_block_size = bdev_logical_block_size(inode->i_bdev);
 157                /*
 158                 * Determine the number of bytes from i_size_read() minus
 159                 * one (1) logical sector from underlying struct block_device
 160                 */
 161                dev_size = (i_size_read(file->f_mapping->host) -
 162                                       fd_dev->fd_block_size);
 163
 164                pr_debug("FILEIO: Using size: %llu bytes from struct"
 165                        " block_device blocks: %llu logical_block_size: %d\n",
 166                        dev_size, div_u64(dev_size, fd_dev->fd_block_size),
 167                        fd_dev->fd_block_size);
 168                /*
 169                 * Check if the underlying struct block_device request_queue supports
 170                 * the QUEUE_FLAG_DISCARD bit for UNMAP/WRITE_SAME in SCSI + TRIM
 171                 * in ATA and we need to set TPE=1
 172                 */
 173                if (blk_queue_discard(q)) {
 174                        dev->dev_attrib.max_unmap_lba_count =
 175                                q->limits.max_discard_sectors;
 176                        /*
 177                         * Currently hardcoded to 1 in Linux/SCSI code..
 178                         */
 179                        dev->dev_attrib.max_unmap_block_desc_count = 1;
 180                        dev->dev_attrib.unmap_granularity =
 181                                q->limits.discard_granularity >> 9;
 182                        dev->dev_attrib.unmap_granularity_alignment =
 183                                q->limits.discard_alignment;
 184                        pr_debug("IFILE: BLOCK Discard support available,"
 185                                        " disabled by default\n");
 186                }
 187                /*
 188                 * Enable write same emulation for IBLOCK and use 0xFFFF as
 189                 * the smaller WRITE_SAME(10) only has a two-byte block count.
 190                 */
 191                dev->dev_attrib.max_write_same_len = 0xFFFF;
 192
 193                if (blk_queue_nonrot(q))
 194                        dev->dev_attrib.is_nonrot = 1;
 195        } else {
 196                if (!(fd_dev->fbd_flags & FBDF_HAS_SIZE)) {
 197                        pr_err("FILEIO: Missing fd_dev_size="
 198                                " parameter, and no backing struct"
 199                                " block_device\n");
 200                        goto fail;
 201                }
 202
 203                fd_dev->fd_block_size = FD_BLOCKSIZE;
 204                /*
 205                 * Limit UNMAP emulation to 8k Number of LBAs (NoLB)
 206                 */
 207                dev->dev_attrib.max_unmap_lba_count = 0x2000;
 208                /*
 209                 * Currently hardcoded to 1 in Linux/SCSI code..
 210                 */
 211                dev->dev_attrib.max_unmap_block_desc_count = 1;
 212                dev->dev_attrib.unmap_granularity = 1;
 213                dev->dev_attrib.unmap_granularity_alignment = 0;
 214
 215                /*
 216                 * Limit WRITE_SAME w/ UNMAP=0 emulation to 8k Number of LBAs (NoLB)
 217                 * based upon struct iovec limit for vfs_writev()
 218                 */
 219                dev->dev_attrib.max_write_same_len = 0x1000;
 220        }
 221
 222        dev->dev_attrib.hw_block_size = fd_dev->fd_block_size;
 223        dev->dev_attrib.hw_max_sectors = FD_MAX_SECTORS;
 224        dev->dev_attrib.hw_queue_depth = FD_MAX_DEVICE_QUEUE_DEPTH;
 225
 226        if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
 227                pr_debug("FILEIO: Forcing setting of emulate_write_cache=1"
 228                        " with FDBD_HAS_BUFFERED_IO_WCE\n");
 229                dev->dev_attrib.emulate_write_cache = 1;
 230        }
 231
 232        fd_dev->fd_dev_id = fd_host->fd_host_dev_id_count++;
 233        fd_dev->fd_queue_depth = dev->queue_depth;
 234
 235        pr_debug("CORE_FILE[%u] - Added TCM FILEIO Device ID: %u at %s,"
 236                " %llu total bytes\n", fd_host->fd_host_id, fd_dev->fd_dev_id,
 237                        fd_dev->fd_dev_name, fd_dev->fd_dev_size);
 238
 239        return 0;
 240fail:
 241        if (fd_dev->fd_file) {
 242                filp_close(fd_dev->fd_file, NULL);
 243                fd_dev->fd_file = NULL;
 244        }
 245        return ret;
 246}
 247
 248static void fd_free_device(struct se_device *dev)
 249{
 250        struct fd_dev *fd_dev = FD_DEV(dev);
 251
 252        if (fd_dev->fd_file) {
 253                filp_close(fd_dev->fd_file, NULL);
 254                fd_dev->fd_file = NULL;
 255        }
 256
 257        kfree(fd_dev);
 258}
 259
 260static int fd_do_rw(struct se_cmd *cmd, struct scatterlist *sgl,
 261                u32 sgl_nents, int is_write)
 262{
 263        struct se_device *se_dev = cmd->se_dev;
 264        struct fd_dev *dev = FD_DEV(se_dev);
 265        struct file *fd = dev->fd_file;
 266        struct scatterlist *sg;
 267        struct iovec *iov;
 268        mm_segment_t old_fs;
 269        loff_t pos = (cmd->t_task_lba * se_dev->dev_attrib.block_size);
 270        int ret = 0, i;
 271
 272        iov = kzalloc(sizeof(struct iovec) * sgl_nents, GFP_KERNEL);
 273        if (!iov) {
 274                pr_err("Unable to allocate fd_do_readv iov[]\n");
 275                return -ENOMEM;
 276        }
 277
 278        for_each_sg(sgl, sg, sgl_nents, i) {
 279                iov[i].iov_len = sg->length;
 280                iov[i].iov_base = kmap(sg_page(sg)) + sg->offset;
 281        }
 282
 283        old_fs = get_fs();
 284        set_fs(get_ds());
 285
 286        if (is_write)
 287                ret = vfs_writev(fd, &iov[0], sgl_nents, &pos);
 288        else
 289                ret = vfs_readv(fd, &iov[0], sgl_nents, &pos);
 290
 291        set_fs(old_fs);
 292
 293        for_each_sg(sgl, sg, sgl_nents, i)
 294                kunmap(sg_page(sg));
 295
 296        kfree(iov);
 297
 298        if (is_write) {
 299                if (ret < 0 || ret != cmd->data_length) {
 300                        pr_err("%s() write returned %d\n", __func__, ret);
 301                        return (ret < 0 ? ret : -EINVAL);
 302                }
 303        } else {
 304                /*
 305                 * Return zeros and GOOD status even if the READ did not return
 306                 * the expected virt_size for struct file w/o a backing struct
 307                 * block_device.
 308                 */
 309                if (S_ISBLK(file_inode(fd)->i_mode)) {
 310                        if (ret < 0 || ret != cmd->data_length) {
 311                                pr_err("%s() returned %d, expecting %u for "
 312                                                "S_ISBLK\n", __func__, ret,
 313                                                cmd->data_length);
 314                                return (ret < 0 ? ret : -EINVAL);
 315                        }
 316                } else {
 317                        if (ret < 0) {
 318                                pr_err("%s() returned %d for non S_ISBLK\n",
 319                                                __func__, ret);
 320                                return ret;
 321                        }
 322                }
 323        }
 324        return 1;
 325}
 326
 327static sense_reason_t
 328fd_execute_sync_cache(struct se_cmd *cmd)
 329{
 330        struct se_device *dev = cmd->se_dev;
 331        struct fd_dev *fd_dev = FD_DEV(dev);
 332        int immed = (cmd->t_task_cdb[1] & 0x2);
 333        loff_t start, end;
 334        int ret;
 335
 336        /*
 337         * If the Immediate bit is set, queue up the GOOD response
 338         * for this SYNCHRONIZE_CACHE op
 339         */
 340        if (immed)
 341                target_complete_cmd(cmd, SAM_STAT_GOOD);
 342
 343        /*
 344         * Determine if we will be flushing the entire device.
 345         */
 346        if (cmd->t_task_lba == 0 && cmd->data_length == 0) {
 347                start = 0;
 348                end = LLONG_MAX;
 349        } else {
 350                start = cmd->t_task_lba * dev->dev_attrib.block_size;
 351                if (cmd->data_length)
 352                        end = start + cmd->data_length;
 353                else
 354                        end = LLONG_MAX;
 355        }
 356
 357        ret = vfs_fsync_range(fd_dev->fd_file, start, end, 1);
 358        if (ret != 0)
 359                pr_err("FILEIO: vfs_fsync_range() failed: %d\n", ret);
 360
 361        if (immed)
 362                return 0;
 363
 364        if (ret)
 365                target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
 366        else
 367                target_complete_cmd(cmd, SAM_STAT_GOOD);
 368
 369        return 0;
 370}
 371
 372static unsigned char *
 373fd_setup_write_same_buf(struct se_cmd *cmd, struct scatterlist *sg,
 374                    unsigned int len)
 375{
 376        struct se_device *se_dev = cmd->se_dev;
 377        unsigned int block_size = se_dev->dev_attrib.block_size;
 378        unsigned int i = 0, end;
 379        unsigned char *buf, *p, *kmap_buf;
 380
 381        buf = kzalloc(min_t(unsigned int, len, PAGE_SIZE), GFP_KERNEL);
 382        if (!buf) {
 383                pr_err("Unable to allocate fd_execute_write_same buf\n");
 384                return NULL;
 385        }
 386
 387        kmap_buf = kmap(sg_page(sg)) + sg->offset;
 388        if (!kmap_buf) {
 389                pr_err("kmap() failed in fd_setup_write_same\n");
 390                kfree(buf);
 391                return NULL;
 392        }
 393        /*
 394         * Fill local *buf to contain multiple WRITE_SAME blocks up to
 395         * min(len, PAGE_SIZE)
 396         */
 397        p = buf;
 398        end = min_t(unsigned int, len, PAGE_SIZE);
 399
 400        while (i < end) {
 401                memcpy(p, kmap_buf, block_size);
 402
 403                i += block_size;
 404                p += block_size;
 405        }
 406        kunmap(sg_page(sg));
 407
 408        return buf;
 409}
 410
 411static sense_reason_t
 412fd_execute_write_same(struct se_cmd *cmd)
 413{
 414        struct se_device *se_dev = cmd->se_dev;
 415        struct fd_dev *fd_dev = FD_DEV(se_dev);
 416        struct file *f = fd_dev->fd_file;
 417        struct scatterlist *sg;
 418        struct iovec *iov;
 419        mm_segment_t old_fs;
 420        sector_t nolb = sbc_get_write_same_sectors(cmd);
 421        loff_t pos = cmd->t_task_lba * se_dev->dev_attrib.block_size;
 422        unsigned int len, len_tmp, iov_num;
 423        int i, rc;
 424        unsigned char *buf;
 425
 426        if (!nolb) {
 427                target_complete_cmd(cmd, SAM_STAT_GOOD);
 428                return 0;
 429        }
 430        sg = &cmd->t_data_sg[0];
 431
 432        if (cmd->t_data_nents > 1 ||
 433            sg->length != cmd->se_dev->dev_attrib.block_size) {
 434                pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
 435                        " block_size: %u\n", cmd->t_data_nents, sg->length,
 436                        cmd->se_dev->dev_attrib.block_size);
 437                return TCM_INVALID_CDB_FIELD;
 438        }
 439
 440        len = len_tmp = nolb * se_dev->dev_attrib.block_size;
 441        iov_num = DIV_ROUND_UP(len, PAGE_SIZE);
 442
 443        buf = fd_setup_write_same_buf(cmd, sg, len);
 444        if (!buf)
 445                return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 446
 447        iov = vzalloc(sizeof(struct iovec) * iov_num);
 448        if (!iov) {
 449                pr_err("Unable to allocate fd_execute_write_same iovecs\n");
 450                kfree(buf);
 451                return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 452        }
 453        /*
 454         * Map the single fabric received scatterlist block now populated
 455         * in *buf into each iovec for I/O submission.
 456         */
 457        for (i = 0; i < iov_num; i++) {
 458                iov[i].iov_base = buf;
 459                iov[i].iov_len = min_t(unsigned int, len_tmp, PAGE_SIZE);
 460                len_tmp -= iov[i].iov_len;
 461        }
 462
 463        old_fs = get_fs();
 464        set_fs(get_ds());
 465        rc = vfs_writev(f, &iov[0], iov_num, &pos);
 466        set_fs(old_fs);
 467
 468        vfree(iov);
 469        kfree(buf);
 470
 471        if (rc < 0 || rc != len) {
 472                pr_err("vfs_writev() returned %d for write same\n", rc);
 473                return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 474        }
 475
 476        target_complete_cmd(cmd, SAM_STAT_GOOD);
 477        return 0;
 478}
 479
 480static sense_reason_t
 481fd_do_unmap(struct se_cmd *cmd, void *priv, sector_t lba, sector_t nolb)
 482{
 483        struct file *file = priv;
 484        struct inode *inode = file->f_mapping->host;
 485        int ret;
 486
 487        if (S_ISBLK(inode->i_mode)) {
 488                /* The backend is block device, use discard */
 489                struct block_device *bdev = inode->i_bdev;
 490
 491                ret = blkdev_issue_discard(bdev, lba,
 492                                nolb, GFP_KERNEL, 0);
 493                if (ret < 0) {
 494                        pr_warn("FILEIO: blkdev_issue_discard() failed: %d\n",
 495                                ret);
 496                        return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 497                }
 498        } else {
 499                /* The backend is normal file, use fallocate */
 500                struct se_device *se_dev = cmd->se_dev;
 501                loff_t pos = lba * se_dev->dev_attrib.block_size;
 502                unsigned int len = nolb * se_dev->dev_attrib.block_size;
 503                int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
 504
 505                if (!file->f_op->fallocate)
 506                        return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 507
 508                ret = file->f_op->fallocate(file, mode, pos, len);
 509                if (ret < 0) {
 510                        pr_warn("FILEIO: fallocate() failed: %d\n", ret);
 511                        return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 512                }
 513        }
 514
 515        return 0;
 516}
 517
 518static sense_reason_t
 519fd_execute_write_same_unmap(struct se_cmd *cmd)
 520{
 521        struct se_device *se_dev = cmd->se_dev;
 522        struct fd_dev *fd_dev = FD_DEV(se_dev);
 523        struct file *file = fd_dev->fd_file;
 524        sector_t lba = cmd->t_task_lba;
 525        sector_t nolb = sbc_get_write_same_sectors(cmd);
 526        int ret;
 527
 528        if (!nolb) {
 529                target_complete_cmd(cmd, SAM_STAT_GOOD);
 530                return 0;
 531        }
 532
 533        ret = fd_do_unmap(cmd, file, lba, nolb);
 534        if (ret)
 535                return ret;
 536
 537        target_complete_cmd(cmd, GOOD);
 538        return 0;
 539}
 540
 541static sense_reason_t
 542fd_execute_unmap(struct se_cmd *cmd)
 543{
 544        struct file *file = FD_DEV(cmd->se_dev)->fd_file;
 545
 546        return sbc_execute_unmap(cmd, fd_do_unmap, file);
 547}
 548
 549static sense_reason_t
 550fd_execute_rw(struct se_cmd *cmd)
 551{
 552        struct scatterlist *sgl = cmd->t_data_sg;
 553        u32 sgl_nents = cmd->t_data_nents;
 554        enum dma_data_direction data_direction = cmd->data_direction;
 555        struct se_device *dev = cmd->se_dev;
 556        int ret = 0;
 557
 558        /*
 559         * Call vectorized fileio functions to map struct scatterlist
 560         * physical memory addresses to struct iovec virtual memory.
 561         */
 562        if (data_direction == DMA_FROM_DEVICE) {
 563                ret = fd_do_rw(cmd, sgl, sgl_nents, 0);
 564        } else {
 565                ret = fd_do_rw(cmd, sgl, sgl_nents, 1);
 566                /*
 567                 * Perform implict vfs_fsync_range() for fd_do_writev() ops
 568                 * for SCSI WRITEs with Forced Unit Access (FUA) set.
 569                 * Allow this to happen independent of WCE=0 setting.
 570                 */
 571                if (ret > 0 &&
 572                    dev->dev_attrib.emulate_fua_write > 0 &&
 573                    (cmd->se_cmd_flags & SCF_FUA)) {
 574                        struct fd_dev *fd_dev = FD_DEV(dev);
 575                        loff_t start = cmd->t_task_lba *
 576                                dev->dev_attrib.block_size;
 577                        loff_t end = start + cmd->data_length;
 578
 579                        vfs_fsync_range(fd_dev->fd_file, start, end, 1);
 580                }
 581        }
 582
 583        if (ret < 0)
 584                return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 585
 586        if (ret)
 587                target_complete_cmd(cmd, SAM_STAT_GOOD);
 588        return 0;
 589}
 590
 591enum {
 592        Opt_fd_dev_name, Opt_fd_dev_size, Opt_fd_buffered_io, Opt_err
 593};
 594
 595static match_table_t tokens = {
 596        {Opt_fd_dev_name, "fd_dev_name=%s"},
 597        {Opt_fd_dev_size, "fd_dev_size=%s"},
 598        {Opt_fd_buffered_io, "fd_buffered_io=%d"},
 599        {Opt_err, NULL}
 600};
 601
 602static ssize_t fd_set_configfs_dev_params(struct se_device *dev,
 603                const char *page, ssize_t count)
 604{
 605        struct fd_dev *fd_dev = FD_DEV(dev);
 606        char *orig, *ptr, *arg_p, *opts;
 607        substring_t args[MAX_OPT_ARGS];
 608        int ret = 0, arg, token;
 609
 610        opts = kstrdup(page, GFP_KERNEL);
 611        if (!opts)
 612                return -ENOMEM;
 613
 614        orig = opts;
 615
 616        while ((ptr = strsep(&opts, ",\n")) != NULL) {
 617                if (!*ptr)
 618                        continue;
 619
 620                token = match_token(ptr, tokens, args);
 621                switch (token) {
 622                case Opt_fd_dev_name:
 623                        if (match_strlcpy(fd_dev->fd_dev_name, &args[0],
 624                                FD_MAX_DEV_NAME) == 0) {
 625                                ret = -EINVAL;
 626                                break;
 627                        }
 628                        pr_debug("FILEIO: Referencing Path: %s\n",
 629                                        fd_dev->fd_dev_name);
 630                        fd_dev->fbd_flags |= FBDF_HAS_PATH;
 631                        break;
 632                case Opt_fd_dev_size:
 633                        arg_p = match_strdup(&args[0]);
 634                        if (!arg_p) {
 635                                ret = -ENOMEM;
 636                                break;
 637                        }
 638                        ret = strict_strtoull(arg_p, 0, &fd_dev->fd_dev_size);
 639                        kfree(arg_p);
 640                        if (ret < 0) {
 641                                pr_err("strict_strtoull() failed for"
 642                                                " fd_dev_size=\n");
 643                                goto out;
 644                        }
 645                        pr_debug("FILEIO: Referencing Size: %llu"
 646                                        " bytes\n", fd_dev->fd_dev_size);
 647                        fd_dev->fbd_flags |= FBDF_HAS_SIZE;
 648                        break;
 649                case Opt_fd_buffered_io:
 650                        match_int(args, &arg);
 651                        if (arg != 1) {
 652                                pr_err("bogus fd_buffered_io=%d value\n", arg);
 653                                ret = -EINVAL;
 654                                goto out;
 655                        }
 656
 657                        pr_debug("FILEIO: Using buffered I/O"
 658                                " operations for struct fd_dev\n");
 659
 660                        fd_dev->fbd_flags |= FDBD_HAS_BUFFERED_IO_WCE;
 661                        break;
 662                default:
 663                        break;
 664                }
 665        }
 666
 667out:
 668        kfree(orig);
 669        return (!ret) ? count : ret;
 670}
 671
 672static ssize_t fd_show_configfs_dev_params(struct se_device *dev, char *b)
 673{
 674        struct fd_dev *fd_dev = FD_DEV(dev);
 675        ssize_t bl = 0;
 676
 677        bl = sprintf(b + bl, "TCM FILEIO ID: %u", fd_dev->fd_dev_id);
 678        bl += sprintf(b + bl, "        File: %s  Size: %llu  Mode: %s\n",
 679                fd_dev->fd_dev_name, fd_dev->fd_dev_size,
 680                (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) ?
 681                "Buffered-WCE" : "O_DSYNC");
 682        return bl;
 683}
 684
 685static sector_t fd_get_blocks(struct se_device *dev)
 686{
 687        struct fd_dev *fd_dev = FD_DEV(dev);
 688        struct file *f = fd_dev->fd_file;
 689        struct inode *i = f->f_mapping->host;
 690        unsigned long long dev_size;
 691        /*
 692         * When using a file that references an underlying struct block_device,
 693         * ensure dev_size is always based on the current inode size in order
 694         * to handle underlying block_device resize operations.
 695         */
 696        if (S_ISBLK(i->i_mode))
 697                dev_size = i_size_read(i);
 698        else
 699                dev_size = fd_dev->fd_dev_size;
 700
 701        return div_u64(dev_size - dev->dev_attrib.block_size,
 702                       dev->dev_attrib.block_size);
 703}
 704
 705static struct sbc_ops fd_sbc_ops = {
 706        .execute_rw             = fd_execute_rw,
 707        .execute_sync_cache     = fd_execute_sync_cache,
 708        .execute_write_same     = fd_execute_write_same,
 709        .execute_write_same_unmap = fd_execute_write_same_unmap,
 710        .execute_unmap          = fd_execute_unmap,
 711};
 712
 713static sense_reason_t
 714fd_parse_cdb(struct se_cmd *cmd)
 715{
 716        return sbc_parse_cdb(cmd, &fd_sbc_ops);
 717}
 718
 719static struct se_subsystem_api fileio_template = {
 720        .name                   = "fileio",
 721        .inquiry_prod           = "FILEIO",
 722        .inquiry_rev            = FD_VERSION,
 723        .owner                  = THIS_MODULE,
 724        .transport_type         = TRANSPORT_PLUGIN_VHBA_PDEV,
 725        .attach_hba             = fd_attach_hba,
 726        .detach_hba             = fd_detach_hba,
 727        .alloc_device           = fd_alloc_device,
 728        .configure_device       = fd_configure_device,
 729        .free_device            = fd_free_device,
 730        .parse_cdb              = fd_parse_cdb,
 731        .set_configfs_dev_params = fd_set_configfs_dev_params,
 732        .show_configfs_dev_params = fd_show_configfs_dev_params,
 733        .get_device_type        = sbc_get_device_type,
 734        .get_blocks             = fd_get_blocks,
 735};
 736
 737static int __init fileio_module_init(void)
 738{
 739        return transport_subsystem_register(&fileio_template);
 740}
 741
 742static void __exit fileio_module_exit(void)
 743{
 744        transport_subsystem_release(&fileio_template);
 745}
 746
 747MODULE_DESCRIPTION("TCM FILEIO subsystem plugin");
 748MODULE_AUTHOR("nab@Linux-iSCSI.org");
 749MODULE_LICENSE("GPL");
 750
 751module_init(fileio_module_init);
 752module_exit(fileio_module_exit);
 753
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