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  * (c) Copyright 2005-2013 Datera, Inc.
   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
  43 static 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  */
  52 static 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\n",
  70                 hba->hba_id, fd_host->fd_host_id);
  71
  72         return 0;
  73 }
  74
  75 static void fd_detach_hba(struct se_hba *hba)
  76 {
  77         struct fd_host *fd_host = hba->hba_ptr;
  78
  79         pr_debug("CORE_HBA[%d] - Detached FILEIO HBA: %u from Generic"
  80                 " Target Core\n", hba->hba_id, fd_host->fd_host_id);
  81
  82         kfree(fd_host);
  83         hba->hba_ptr = NULL;
  84 }
  85
  86 static struct se_device *fd_alloc_device(struct se_hba *hba, const char *name)
  87 {
  88         struct fd_dev *fd_dev;
  89         struct fd_host *fd_host = hba->hba_ptr;
  90
  91         fd_dev = kzalloc(sizeof(struct fd_dev), GFP_KERNEL);
  92         if (!fd_dev) {
  93                 pr_err("Unable to allocate memory for struct fd_dev\n");
  94                 return NULL;
  95         }
  96
  97         fd_dev->fd_host = fd_host;
  98
  99         pr_debug("FILEIO: Allocated fd_dev for %p\n", name);
 100
 101         return &fd_dev->dev;
 102 }
 103
 104 static int fd_configure_device(struct se_device *dev)
 105 {
 106         struct fd_dev *fd_dev = FD_DEV(dev);
 107         struct fd_host *fd_host = dev->se_hba->hba_ptr;
 108         struct file *file;
 109         struct inode *inode = NULL;
 110         int flags, ret = -EINVAL;
 111
 112         if (!(fd_dev->fbd_flags & FBDF_HAS_PATH)) {
 113                 pr_err("Missing fd_dev_name=\n");
 114                 return -EINVAL;
 115         }
 116
 117         /*
 118          * Use O_DSYNC by default instead of O_SYNC to forgo syncing
 119          * of pure timestamp updates.
 120          */
 121         flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
 122
 123         /*
 124          * Optionally allow fd_buffered_io=1 to be enabled for people
 125          * who want use the fs buffer cache as an WriteCache mechanism.
 126          *
 127          * This means that in event of a hard failure, there is a risk
 128          * of silent data-loss if the SCSI client has *not* performed a
 129          * forced unit access (FUA) write, or issued SYNCHRONIZE_CACHE
 130          * to write-out the entire device cache.
 131          */
 132         if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
 133                 pr_debug("FILEIO: Disabling O_DSYNC, using buffered FILEIO\n");
 134                 flags &= ~O_DSYNC;
 135         }
 136
 137         file = filp_open(fd_dev->fd_dev_name, flags, 0600);
 138         if (IS_ERR(file)) {
 139                 pr_err("filp_open(%s) failed\n", fd_dev->fd_dev_name);
 140                 ret = PTR_ERR(file);
 141                 goto fail;
 142         }
 143         fd_dev->fd_file = file;
 144         /*
 145          * If using a block backend with this struct file, we extract
 146          * fd_dev->fd_[block,dev]_size from struct block_device.
 147          *
 148          * Otherwise, we use the passed fd_size= from configfs
 149          */
 150         inode = file->f_mapping->host;
 151         if (S_ISBLK(inode->i_mode)) {
 152                 struct request_queue *q = bdev_get_queue(inode->i_bdev);
 153                 unsigned long long dev_size;
 154
 155                 fd_dev->fd_block_size = bdev_logical_block_size(inode->i_bdev);
 156                 /*
 157                  * Determine the number of bytes from i_size_read() minus
 158                  * one (1) logical sector from underlying struct block_device
 159                  */
 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                 /*
 168                  * Check if the underlying struct block_device request_queue supports
 169                  * the QUEUE_FLAG_DISCARD bit for UNMAP/WRITE_SAME in SCSI + TRIM
 170                  * in ATA and we need to set TPE=1
 171                  */
 172                 if (blk_queue_discard(q)) {
 173                         dev->dev_attrib.max_unmap_lba_count =
 174                                 q->limits.max_discard_sectors;
 175                         /*
 176                          * Currently hardcoded to 1 in Linux/SCSI code..
 177                          */
 178                         dev->dev_attrib.max_unmap_block_desc_count = 1;
 179                         dev->dev_attrib.unmap_granularity =
 180                                 q->limits.discard_granularity >> 9;
 181                         dev->dev_attrib.unmap_granularity_alignment =
 182                                 q->limits.discard_alignment;
 183                         pr_debug("IFILE: BLOCK Discard support available,"
 184                                         " disabled by default\n");
 185                 }
 186                 /*
 187                  * Enable write same emulation for IBLOCK and use 0xFFFF as
 188                  * the smaller WRITE_SAME(10) only has a two-byte block count.
 189                  */
 190                 dev->dev_attrib.max_write_same_len = 0xFFFF;
 191
 192                 if (blk_queue_nonrot(q))
 193                         dev->dev_attrib.is_nonrot = 1;
 194         } else {
 195                 if (!(fd_dev->fbd_flags & FBDF_HAS_SIZE)) {
 196                         pr_err("FILEIO: Missing fd_dev_size="
 197                                 " parameter, and no backing struct"
 198                                 " block_device\n");
 199                         goto fail;
 200                 }
 201
 202                 fd_dev->fd_block_size = FD_BLOCKSIZE;
 203                 /*
 204                  * Limit UNMAP emulation to 8k Number of LBAs (NoLB)
 205                  */
 206                 dev->dev_attrib.max_unmap_lba_count = 0x2000;
 207                 /*
 208                  * Currently hardcoded to 1 in Linux/SCSI code..
 209                  */
 210                 dev->dev_attrib.max_unmap_block_desc_count = 1;
 211                 dev->dev_attrib.unmap_granularity = 1;
 212                 dev->dev_attrib.unmap_granularity_alignment = 0;
 213
 214                 /*
 215                  * Limit WRITE_SAME w/ UNMAP=0 emulation to 8k Number of LBAs (NoLB)
 216                  * based upon struct iovec limit for vfs_writev()
 217                  */
 218                 dev->dev_attrib.max_write_same_len = 0x1000;
 219         }
 220
 221         dev->dev_attrib.hw_block_size = fd_dev->fd_block_size;
 222         dev->dev_attrib.max_bytes_per_io = FD_MAX_BYTES;
 223         dev->dev_attrib.hw_max_sectors = FD_MAX_BYTES / fd_dev->fd_block_size;
 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;
 240 fail:
 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
 248 static 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
 260 static 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
 327 static sense_reason_t
 328 fd_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
 372 static unsigned char *
 373 fd_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
 411 static sense_reason_t
 412 fd_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
 480 static sense_reason_t
 481 fd_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
 518 static sense_reason_t
 519 fd_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
 541 static sense_reason_t
 542 fd_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
 549 static sense_reason_t
 550 fd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 551               enum dma_data_direction data_direction)
 552 {
 553         struct se_device *dev = cmd->se_dev;
 554         int ret = 0;
 555
 556         /*
 557          * Call vectorized fileio functions to map struct scatterlist
 558          * physical memory addresses to struct iovec virtual memory.
 559          */
 560         if (data_direction == DMA_FROM_DEVICE) {
 561                 ret = fd_do_rw(cmd, sgl, sgl_nents, 0);
 562         } else {
 563                 ret = fd_do_rw(cmd, sgl, sgl_nents, 1);
 564                 /*
 565                  * Perform implicit vfs_fsync_range() for fd_do_writev() ops
 566                  * for SCSI WRITEs with Forced Unit Access (FUA) set.
 567                  * Allow this to happen independent of WCE=0 setting.
 568                  */
 569                 if (ret > 0 &&
 570                     dev->dev_attrib.emulate_fua_write > 0 &&
 571                     (cmd->se_cmd_flags & SCF_FUA)) {
 572                         struct fd_dev *fd_dev = FD_DEV(dev);
 573                         loff_t start = cmd->t_task_lba *
 574                                 dev->dev_attrib.block_size;
 575                         loff_t end = start + cmd->data_length;
 576
 577                         vfs_fsync_range(fd_dev->fd_file, start, end, 1);
 578                 }
 579         }
 580
 581         if (ret < 0)
 582                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 583
 584         if (ret)
 585                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 586         return 0;
 587 }
 588
 589 enum {
 590         Opt_fd_dev_name, Opt_fd_dev_size, Opt_fd_buffered_io, Opt_err
 591 };
 592
 593 static match_table_t tokens = {
 594         {Opt_fd_dev_name, "fd_dev_name=%s"},
 595         {Opt_fd_dev_size, "fd_dev_size=%s"},
 596         {Opt_fd_buffered_io, "fd_buffered_io=%d"},
 597         {Opt_err, NULL}
 598 };
 599
 600 static ssize_t fd_set_configfs_dev_params(struct se_device *dev,
 601                 const char *page, ssize_t count)
 602 {
 603         struct fd_dev *fd_dev = FD_DEV(dev);
 604         char *orig, *ptr, *arg_p, *opts;
 605         substring_t args[MAX_OPT_ARGS];
 606         int ret = 0, arg, token;
 607
 608         opts = kstrdup(page, GFP_KERNEL);
 609         if (!opts)
 610                 return -ENOMEM;
 611
 612         orig = opts;
 613
 614         while ((ptr = strsep(&opts, ",\n")) != NULL) {
 615                 if (!*ptr)
 616                         continue;
 617
 618                 token = match_token(ptr, tokens, args);
 619                 switch (token) {
 620                 case Opt_fd_dev_name:
 621                         if (match_strlcpy(fd_dev->fd_dev_name, &args[0],
 622                                 FD_MAX_DEV_NAME) == 0) {
 623                                 ret = -EINVAL;
 624                                 break;
 625                         }
 626                         pr_debug("FILEIO: Referencing Path: %s\n",
 627                                         fd_dev->fd_dev_name);
 628                         fd_dev->fbd_flags |= FBDF_HAS_PATH;
 629                         break;
 630                 case Opt_fd_dev_size:
 631                         arg_p = match_strdup(&args[0]);
 632                         if (!arg_p) {
 633                                 ret = -ENOMEM;
 634                                 break;
 635                         }
 636                         ret = kstrtoull(arg_p, 0, &fd_dev->fd_dev_size);
 637                         kfree(arg_p);
 638                         if (ret < 0) {
 639                                 pr_err("kstrtoull() failed for"
 640                                                 " fd_dev_size=\n");
 641                                 goto out;
 642                         }
 643                         pr_debug("FILEIO: Referencing Size: %llu"
 644                                         " bytes\n", fd_dev->fd_dev_size);
 645                         fd_dev->fbd_flags |= FBDF_HAS_SIZE;
 646                         break;
 647                 case Opt_fd_buffered_io:
 648                         match_int(args, &arg);
 649                         if (arg != 1) {
 650                                 pr_err("bogus fd_buffered_io=%d value\n", arg);
 651                                 ret = -EINVAL;
 652                                 goto out;
 653                         }
 654
 655                         pr_debug("FILEIO: Using buffered I/O"
 656                                 " operations for struct fd_dev\n");
 657
 658                         fd_dev->fbd_flags |= FDBD_HAS_BUFFERED_IO_WCE;
 659                         break;
 660                 default:
 661                         break;
 662                 }
 663         }
 664
 665 out:
 666         kfree(orig);
 667         return (!ret) ? count : ret;
 668 }
 669
 670 static ssize_t fd_show_configfs_dev_params(struct se_device *dev, char *b)
 671 {
 672         struct fd_dev *fd_dev = FD_DEV(dev);
 673         ssize_t bl = 0;
 674
 675         bl = sprintf(b + bl, "TCM FILEIO ID: %u", fd_dev->fd_dev_id);
 676         bl += sprintf(b + bl, "        File: %s  Size: %llu  Mode: %s\n",
 677                 fd_dev->fd_dev_name, fd_dev->fd_dev_size,
 678                 (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) ?
 679                 "Buffered-WCE" : "O_DSYNC");
 680         return bl;
 681 }
 682
 683 static sector_t fd_get_blocks(struct se_device *dev)
 684 {
 685         struct fd_dev *fd_dev = FD_DEV(dev);
 686         struct file *f = fd_dev->fd_file;
 687         struct inode *i = f->f_mapping->host;
 688         unsigned long long dev_size;
 689         /*
 690          * When using a file that references an underlying struct block_device,
 691          * ensure dev_size is always based on the current inode size in order
 692          * to handle underlying block_device resize operations.
 693          */
 694         if (S_ISBLK(i->i_mode))
 695                 dev_size = i_size_read(i);
 696         else
 697                 dev_size = fd_dev->fd_dev_size;
 698
 699         return div_u64(dev_size - dev->dev_attrib.block_size,
 700                        dev->dev_attrib.block_size);
 701 }
 702
 703 static struct sbc_ops fd_sbc_ops = {
 704         .execute_rw             = fd_execute_rw,
 705         .execute_sync_cache     = fd_execute_sync_cache,
 706         .execute_write_same     = fd_execute_write_same,
 707         .execute_write_same_unmap = fd_execute_write_same_unmap,
 708         .execute_unmap          = fd_execute_unmap,
 709 };
 710
 711 static sense_reason_t
 712 fd_parse_cdb(struct se_cmd *cmd)
 713 {
 714         return sbc_parse_cdb(cmd, &fd_sbc_ops);
 715 }
 716
 717 static struct se_subsystem_api fileio_template = {
 718         .name                   = "fileio",
 719         .inquiry_prod           = "FILEIO",
 720         .inquiry_rev            = FD_VERSION,
 721         .owner                  = THIS_MODULE,
 722         .transport_type         = TRANSPORT_PLUGIN_VHBA_PDEV,
 723         .attach_hba             = fd_attach_hba,
 724         .detach_hba             = fd_detach_hba,
 725         .alloc_device           = fd_alloc_device,
 726         .configure_device       = fd_configure_device,
 727         .free_device            = fd_free_device,
 728         .parse_cdb              = fd_parse_cdb,
 729         .set_configfs_dev_params = fd_set_configfs_dev_params,
 730         .show_configfs_dev_params = fd_show_configfs_dev_params,
 731         .get_device_type        = sbc_get_device_type,
 732         .get_blocks             = fd_get_blocks,
 733 };
 734
 735 static int __init fileio_module_init(void)
 736 {
 737         return transport_subsystem_register(&fileio_template);
 738 }
 739
 740 static void __exit fileio_module_exit(void)
 741 {
 742         transport_subsystem_release(&fileio_template);
 743 }
 744
 745 MODULE_DESCRIPTION("TCM FILEIO subsystem plugin");
 746 MODULE_AUTHOR("nab@Linux-iSCSI.org");
 747 MODULE_LICENSE("GPL");
 748
 749 module_init(fileio_module_init);
 750 module_exit(fileio_module_exit);