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/vmalloc.h>
  34 #include <linux/falloc.h>
  35 #include <scsi/scsi_proto.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 static int fd_attach_hba(struct se_hba *hba, u32 host_id)
  49 {
  50         struct fd_host *fd_host;
  51
  52         fd_host = kzalloc(sizeof(struct fd_host), GFP_KERNEL);
  53         if (!fd_host) {
  54                 pr_err("Unable to allocate memory for struct fd_host\n");
  55                 return -ENOMEM;
  56         }
  57
  58         fd_host->fd_host_id = host_id;
  59
  60         hba->hba_ptr = fd_host;
  61
  62         pr_debug("CORE_HBA[%d] - TCM FILEIO HBA Driver %s on Generic"
  63                 " Target Core Stack %s\n", hba->hba_id, FD_VERSION,
  64                 TARGET_CORE_VERSION);
  65         pr_debug("CORE_HBA[%d] - Attached FILEIO HBA: %u to Generic\n",
  66                 hba->hba_id, fd_host->fd_host_id);
  67
  68         return 0;
  69 }
  70
  71 static void fd_detach_hba(struct se_hba *hba)
  72 {
  73         struct fd_host *fd_host = hba->hba_ptr;
  74
  75         pr_debug("CORE_HBA[%d] - Detached FILEIO HBA: %u from Generic"
  76                 " Target Core\n", hba->hba_id, fd_host->fd_host_id);
  77
  78         kfree(fd_host);
  79         hba->hba_ptr = NULL;
  80 }
  81
  82 static struct se_device *fd_alloc_device(struct se_hba *hba, const char *name)
  83 {
  84         struct fd_dev *fd_dev;
  85         struct fd_host *fd_host = hba->hba_ptr;
  86
  87         fd_dev = kzalloc(sizeof(struct fd_dev), GFP_KERNEL);
  88         if (!fd_dev) {
  89                 pr_err("Unable to allocate memory for struct fd_dev\n");
  90                 return NULL;
  91         }
  92
  93         fd_dev->fd_host = fd_host;
  94
  95         pr_debug("FILEIO: Allocated fd_dev for %p\n", name);
  96
  97         return &fd_dev->dev;
  98 }
  99
 100 static int fd_configure_device(struct se_device *dev)
 101 {
 102         struct fd_dev *fd_dev = FD_DEV(dev);
 103         struct fd_host *fd_host = dev->se_hba->hba_ptr;
 104         struct file *file;
 105         struct inode *inode = NULL;
 106         int flags, ret = -EINVAL;
 107
 108         if (!(fd_dev->fbd_flags & FBDF_HAS_PATH)) {
 109                 pr_err("Missing fd_dev_name=\n");
 110                 return -EINVAL;
 111         }
 112
 113         /*
 114          * Use O_DSYNC by default instead of O_SYNC to forgo syncing
 115          * of pure timestamp updates.
 116          */
 117         flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
 118
 119         /*
 120          * Optionally allow fd_buffered_io=1 to be enabled for people
 121          * who want use the fs buffer cache as an WriteCache mechanism.
 122          *
 123          * This means that in event of a hard failure, there is a risk
 124          * of silent data-loss if the SCSI client has *not* performed a
 125          * forced unit access (FUA) write, or issued SYNCHRONIZE_CACHE
 126          * to write-out the entire device cache.
 127          */
 128         if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
 129                 pr_debug("FILEIO: Disabling O_DSYNC, using buffered FILEIO\n");
 130                 flags &= ~O_DSYNC;
 131         }
 132
 133         file = filp_open(fd_dev->fd_dev_name, flags, 0600);
 134         if (IS_ERR(file)) {
 135                 pr_err("filp_open(%s) failed\n", fd_dev->fd_dev_name);
 136                 ret = PTR_ERR(file);
 137                 goto fail;
 138         }
 139         fd_dev->fd_file = file;
 140         /*
 141          * If using a block backend with this struct file, we extract
 142          * fd_dev->fd_[block,dev]_size from struct block_device.
 143          *
 144          * Otherwise, we use the passed fd_size= from configfs
 145          */
 146         inode = file->f_mapping->host;
 147         if (S_ISBLK(inode->i_mode)) {
 148                 struct request_queue *q = bdev_get_queue(inode->i_bdev);
 149                 unsigned long long dev_size;
 150
 151                 fd_dev->fd_block_size = bdev_logical_block_size(inode->i_bdev);
 152                 /*
 153                  * Determine the number of bytes from i_size_read() minus
 154                  * one (1) logical sector from underlying struct block_device
 155                  */
 156                 dev_size = (i_size_read(file->f_mapping->host) -
 157                                        fd_dev->fd_block_size);
 158
 159                 pr_debug("FILEIO: Using size: %llu bytes from struct"
 160                         " block_device blocks: %llu logical_block_size: %d\n",
 161                         dev_size, div_u64(dev_size, fd_dev->fd_block_size),
 162                         fd_dev->fd_block_size);
 163
 164                 if (target_configure_unmap_from_queue(&dev->dev_attrib, q))
 165                         pr_debug("IFILE: BLOCK Discard support available,"
 166                                  " disabled by default\n");
 167                 /*
 168                  * Enable write same emulation for IBLOCK and use 0xFFFF as
 169                  * the smaller WRITE_SAME(10) only has a two-byte block count.
 170                  */
 171                 dev->dev_attrib.max_write_same_len = 0xFFFF;
 172
 173                 if (blk_queue_nonrot(q))
 174                         dev->dev_attrib.is_nonrot = 1;
 175         } else {
 176                 if (!(fd_dev->fbd_flags & FBDF_HAS_SIZE)) {
 177                         pr_err("FILEIO: Missing fd_dev_size="
 178                                 " parameter, and no backing struct"
 179                                 " block_device\n");
 180                         goto fail;
 181                 }
 182
 183                 fd_dev->fd_block_size = FD_BLOCKSIZE;
 184                 /*
 185                  * Limit UNMAP emulation to 8k Number of LBAs (NoLB)
 186                  */
 187                 dev->dev_attrib.max_unmap_lba_count = 0x2000;
 188                 /*
 189                  * Currently hardcoded to 1 in Linux/SCSI code..
 190                  */
 191                 dev->dev_attrib.max_unmap_block_desc_count = 1;
 192                 dev->dev_attrib.unmap_granularity = 1;
 193                 dev->dev_attrib.unmap_granularity_alignment = 0;
 194
 195                 /*
 196                  * Limit WRITE_SAME w/ UNMAP=0 emulation to 8k Number of LBAs (NoLB)
 197                  * based upon struct iovec limit for vfs_writev()
 198                  */
 199                 dev->dev_attrib.max_write_same_len = 0x1000;
 200         }
 201
 202         dev->dev_attrib.hw_block_size = fd_dev->fd_block_size;
 203         dev->dev_attrib.max_bytes_per_io = FD_MAX_BYTES;
 204         dev->dev_attrib.hw_max_sectors = FD_MAX_BYTES / fd_dev->fd_block_size;
 205         dev->dev_attrib.hw_queue_depth = FD_MAX_DEVICE_QUEUE_DEPTH;
 206
 207         if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
 208                 pr_debug("FILEIO: Forcing setting of emulate_write_cache=1"
 209                         " with FDBD_HAS_BUFFERED_IO_WCE\n");
 210                 dev->dev_attrib.emulate_write_cache = 1;
 211         }
 212
 213         fd_dev->fd_dev_id = fd_host->fd_host_dev_id_count++;
 214         fd_dev->fd_queue_depth = dev->queue_depth;
 215
 216         pr_debug("CORE_FILE[%u] - Added TCM FILEIO Device ID: %u at %s,"
 217                 " %llu total bytes\n", fd_host->fd_host_id, fd_dev->fd_dev_id,
 218                         fd_dev->fd_dev_name, fd_dev->fd_dev_size);
 219
 220         return 0;
 221 fail:
 222         if (fd_dev->fd_file) {
 223                 filp_close(fd_dev->fd_file, NULL);
 224                 fd_dev->fd_file = NULL;
 225         }
 226         return ret;
 227 }
 228
 229 static void fd_dev_call_rcu(struct rcu_head *p)
 230 {
 231         struct se_device *dev = container_of(p, struct se_device, rcu_head);
 232         struct fd_dev *fd_dev = FD_DEV(dev);
 233
 234         kfree(fd_dev);
 235 }
 236
 237 static void fd_free_device(struct se_device *dev)
 238 {
 239         struct fd_dev *fd_dev = FD_DEV(dev);
 240
 241         if (fd_dev->fd_file) {
 242                 filp_close(fd_dev->fd_file, NULL);
 243                 fd_dev->fd_file = NULL;
 244         }
 245         call_rcu(&dev->rcu_head, fd_dev_call_rcu);
 246 }
 247
 248 static int fd_do_rw(struct se_cmd *cmd, struct file *fd,
 249                     u32 block_size, struct scatterlist *sgl,
 250                     u32 sgl_nents, u32 data_length, int is_write)
 251 {
 252         struct scatterlist *sg;
 253         struct iov_iter iter;
 254         struct bio_vec *bvec;
 255         ssize_t len = 0;
 256         loff_t pos = (cmd->t_task_lba * block_size);
 257         int ret = 0, i;
 258
 259         bvec = kcalloc(sgl_nents, sizeof(struct bio_vec), GFP_KERNEL);
 260         if (!bvec) {
 261                 pr_err("Unable to allocate fd_do_readv iov[]\n");
 262                 return -ENOMEM;
 263         }
 264
 265         for_each_sg(sgl, sg, sgl_nents, i) {
 266                 bvec[i].bv_page = sg_page(sg);
 267                 bvec[i].bv_len = sg->length;
 268                 bvec[i].bv_offset = sg->offset;
 269
 270                 len += sg->length;
 271         }
 272
 273         iov_iter_bvec(&iter, ITER_BVEC, bvec, sgl_nents, len);
 274         if (is_write)
 275                 ret = vfs_iter_write(fd, &iter, &pos);
 276         else
 277                 ret = vfs_iter_read(fd, &iter, &pos);
 278
 279         if (is_write) {
 280                 if (ret < 0 || ret != data_length) {
 281                         pr_err("%s() write returned %d\n", __func__, ret);
 282                         if (ret >= 0)
 283                                 ret = -EINVAL;
 284                 }
 285         } else {
 286                 /*
 287                  * Return zeros and GOOD status even if the READ did not return
 288                  * the expected virt_size for struct file w/o a backing struct
 289                  * block_device.
 290                  */
 291                 if (S_ISBLK(file_inode(fd)->i_mode)) {
 292                         if (ret < 0 || ret != data_length) {
 293                                 pr_err("%s() returned %d, expecting %u for "
 294                                                 "S_ISBLK\n", __func__, ret,
 295                                                 data_length);
 296                                 if (ret >= 0)
 297                                         ret = -EINVAL;
 298                         }
 299                 } else {
 300                         if (ret < 0) {
 301                                 pr_err("%s() returned %d for non S_ISBLK\n",
 302                                                 __func__, ret);
 303                         } else if (ret != data_length) {
 304                                 /*
 305                                  * Short read case:
 306                                  * Probably some one truncate file under us.
 307                                  * We must explicitly zero sg-pages to prevent
 308                                  * expose uninizialized pages to userspace.
 309                                  */
 310                                 if (ret < data_length)
 311                                         ret += iov_iter_zero(data_length - ret, &iter);
 312                                 else
 313                                         ret = -EINVAL;
 314                         }
 315                 }
 316         }
 317         kfree(bvec);
 318         return ret;
 319 }
 320
 321 static sense_reason_t
 322 fd_execute_sync_cache(struct se_cmd *cmd)
 323 {
 324         struct se_device *dev = cmd->se_dev;
 325         struct fd_dev *fd_dev = FD_DEV(dev);
 326         int immed = (cmd->t_task_cdb[1] & 0x2);
 327         loff_t start, end;
 328         int ret;
 329
 330         /*
 331          * If the Immediate bit is set, queue up the GOOD response
 332          * for this SYNCHRONIZE_CACHE op
 333          */
 334         if (immed)
 335                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 336
 337         /*
 338          * Determine if we will be flushing the entire device.
 339          */
 340         if (cmd->t_task_lba == 0 && cmd->data_length == 0) {
 341                 start = 0;
 342                 end = LLONG_MAX;
 343         } else {
 344                 start = cmd->t_task_lba * dev->dev_attrib.block_size;
 345                 if (cmd->data_length)
 346                         end = start + cmd->data_length - 1;
 347                 else
 348                         end = LLONG_MAX;
 349         }
 350
 351         ret = vfs_fsync_range(fd_dev->fd_file, start, end, 1);
 352         if (ret != 0)
 353                 pr_err("FILEIO: vfs_fsync_range() failed: %d\n", ret);
 354
 355         if (immed)
 356                 return 0;
 357
 358         if (ret)
 359                 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
 360         else
 361                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 362
 363         return 0;
 364 }
 365
 366 static sense_reason_t
 367 fd_execute_write_same(struct se_cmd *cmd)
 368 {
 369         struct se_device *se_dev = cmd->se_dev;
 370         struct fd_dev *fd_dev = FD_DEV(se_dev);
 371         loff_t pos = cmd->t_task_lba * se_dev->dev_attrib.block_size;
 372         sector_t nolb = sbc_get_write_same_sectors(cmd);
 373         struct iov_iter iter;
 374         struct bio_vec *bvec;
 375         unsigned int len = 0, i;
 376         ssize_t ret;
 377
 378         if (!nolb) {
 379                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 380                 return 0;
 381         }
 382         if (cmd->prot_op) {
 383                 pr_err("WRITE_SAME: Protection information with FILEIO"
 384                        " backends not supported\n");
 385                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 386         }
 387
 388         if (cmd->t_data_nents > 1 ||
 389             cmd->t_data_sg[0].length != cmd->se_dev->dev_attrib.block_size) {
 390                 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
 391                         " block_size: %u\n",
 392                         cmd->t_data_nents,
 393                         cmd->t_data_sg[0].length,
 394                         cmd->se_dev->dev_attrib.block_size);
 395                 return TCM_INVALID_CDB_FIELD;
 396         }
 397
 398         bvec = kcalloc(nolb, sizeof(struct bio_vec), GFP_KERNEL);
 399         if (!bvec)
 400                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 401
 402         for (i = 0; i < nolb; i++) {
 403                 bvec[i].bv_page = sg_page(&cmd->t_data_sg[0]);
 404                 bvec[i].bv_len = cmd->t_data_sg[0].length;
 405                 bvec[i].bv_offset = cmd->t_data_sg[0].offset;
 406
 407                 len += se_dev->dev_attrib.block_size;
 408         }
 409
 410         iov_iter_bvec(&iter, ITER_BVEC, bvec, nolb, len);
 411         ret = vfs_iter_write(fd_dev->fd_file, &iter, &pos);
 412
 413         kfree(bvec);
 414         if (ret < 0 || ret != len) {
 415                 pr_err("vfs_iter_write() returned %zd for write same\n", ret);
 416                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 417         }
 418
 419         target_complete_cmd(cmd, SAM_STAT_GOOD);
 420         return 0;
 421 }
 422
 423 static int
 424 fd_do_prot_fill(struct se_device *se_dev, sector_t lba, sector_t nolb,
 425                 void *buf, size_t bufsize)
 426 {
 427         struct fd_dev *fd_dev = FD_DEV(se_dev);
 428         struct file *prot_fd = fd_dev->fd_prot_file;
 429         sector_t prot_length, prot;
 430         loff_t pos = lba * se_dev->prot_length;
 431
 432         if (!prot_fd) {
 433                 pr_err("Unable to locate fd_dev->fd_prot_file\n");
 434                 return -ENODEV;
 435         }
 436
 437         prot_length = nolb * se_dev->prot_length;
 438
 439         for (prot = 0; prot < prot_length;) {
 440                 sector_t len = min_t(sector_t, bufsize, prot_length - prot);
 441                 ssize_t ret = kernel_write(prot_fd, buf, len, pos + prot);
 442
 443                 if (ret != len) {
 444                         pr_err("vfs_write to prot file failed: %zd\n", ret);
 445                         return ret < 0 ? ret : -ENODEV;
 446                 }
 447                 prot += ret;
 448         }
 449
 450         return 0;
 451 }
 452
 453 static int
 454 fd_do_prot_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
 455 {
 456         void *buf;
 457         int rc;
 458
 459         buf = (void *)__get_free_page(GFP_KERNEL);
 460         if (!buf) {
 461                 pr_err("Unable to allocate FILEIO prot buf\n");
 462                 return -ENOMEM;
 463         }
 464         memset(buf, 0xff, PAGE_SIZE);
 465
 466         rc = fd_do_prot_fill(cmd->se_dev, lba, nolb, buf, PAGE_SIZE);
 467
 468         free_page((unsigned long)buf);
 469
 470         return rc;
 471 }
 472
 473 static sense_reason_t
 474 fd_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
 475 {
 476         struct file *file = FD_DEV(cmd->se_dev)->fd_file;
 477         struct inode *inode = file->f_mapping->host;
 478         int ret;
 479
 480         if (!nolb) {
 481                 return 0;
 482         }
 483
 484         if (cmd->se_dev->dev_attrib.pi_prot_type) {
 485                 ret = fd_do_prot_unmap(cmd, lba, nolb);
 486                 if (ret)
 487                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 488         }
 489
 490         if (S_ISBLK(inode->i_mode)) {
 491                 /* The backend is block device, use discard */
 492                 struct block_device *bdev = inode->i_bdev;
 493                 struct se_device *dev = cmd->se_dev;
 494
 495                 ret = blkdev_issue_discard(bdev,
 496                                            target_to_linux_sector(dev, lba),
 497                                            target_to_linux_sector(dev,  nolb),
 498                                            GFP_KERNEL, 0);
 499                 if (ret < 0) {
 500                         pr_warn("FILEIO: blkdev_issue_discard() failed: %d\n",
 501                                 ret);
 502                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 503                 }
 504         } else {
 505                 /* The backend is normal file, use fallocate */
 506                 struct se_device *se_dev = cmd->se_dev;
 507                 loff_t pos = lba * se_dev->dev_attrib.block_size;
 508                 unsigned int len = nolb * se_dev->dev_attrib.block_size;
 509                 int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
 510
 511                 if (!file->f_op->fallocate)
 512                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 513
 514                 ret = file->f_op->fallocate(file, mode, pos, len);
 515                 if (ret < 0) {
 516                         pr_warn("FILEIO: fallocate() failed: %d\n", ret);
 517                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 518                 }
 519         }
 520
 521         return 0;
 522 }
 523
 524 static sense_reason_t
 525 fd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 526               enum dma_data_direction data_direction)
 527 {
 528         struct se_device *dev = cmd->se_dev;
 529         struct fd_dev *fd_dev = FD_DEV(dev);
 530         struct file *file = fd_dev->fd_file;
 531         struct file *pfile = fd_dev->fd_prot_file;
 532         sense_reason_t rc;
 533         int ret = 0;
 534         /*
 535          * We are currently limited by the number of iovecs (2048) per
 536          * single vfs_[writev,readv] call.
 537          */
 538         if (cmd->data_length > FD_MAX_BYTES) {
 539                 pr_err("FILEIO: Not able to process I/O of %u bytes due to"
 540                        "FD_MAX_BYTES: %u iovec count limitation\n",
 541                         cmd->data_length, FD_MAX_BYTES);
 542                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 543         }
 544         /*
 545          * Call vectorized fileio functions to map struct scatterlist
 546          * physical memory addresses to struct iovec virtual memory.
 547          */
 548         if (data_direction == DMA_FROM_DEVICE) {
 549                 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 550                         ret = fd_do_rw(cmd, pfile, dev->prot_length,
 551                                        cmd->t_prot_sg, cmd->t_prot_nents,
 552                                        cmd->prot_length, 0);
 553                         if (ret < 0)
 554                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 555                 }
 556
 557                 ret = fd_do_rw(cmd, file, dev->dev_attrib.block_size,
 558                                sgl, sgl_nents, cmd->data_length, 0);
 559
 560                 if (ret > 0 && cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 561                         u32 sectors = cmd->data_length >>
 562                                         ilog2(dev->dev_attrib.block_size);
 563
 564                         rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors,
 565                                             0, cmd->t_prot_sg, 0);
 566                         if (rc)
 567                                 return rc;
 568                 }
 569         } else {
 570                 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 571                         u32 sectors = cmd->data_length >>
 572                                         ilog2(dev->dev_attrib.block_size);
 573
 574                         rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors,
 575                                             0, cmd->t_prot_sg, 0);
 576                         if (rc)
 577                                 return rc;
 578                 }
 579
 580                 ret = fd_do_rw(cmd, file, dev->dev_attrib.block_size,
 581                                sgl, sgl_nents, cmd->data_length, 1);
 582                 /*
 583                  * Perform implicit vfs_fsync_range() for fd_do_writev() ops
 584                  * for SCSI WRITEs with Forced Unit Access (FUA) set.
 585                  * Allow this to happen independent of WCE=0 setting.
 586                  */
 587                 if (ret > 0 && (cmd->se_cmd_flags & SCF_FUA)) {
 588                         loff_t start = cmd->t_task_lba *
 589                                 dev->dev_attrib.block_size;
 590                         loff_t end;
 591
 592                         if (cmd->data_length)
 593                                 end = start + cmd->data_length - 1;
 594                         else
 595                                 end = LLONG_MAX;
 596
 597                         vfs_fsync_range(fd_dev->fd_file, start, end, 1);
 598                 }
 599
 600                 if (ret > 0 && cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 601                         ret = fd_do_rw(cmd, pfile, dev->prot_length,
 602                                        cmd->t_prot_sg, cmd->t_prot_nents,
 603                                        cmd->prot_length, 1);
 604                         if (ret < 0)
 605                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 606                 }
 607         }
 608
 609         if (ret < 0)
 610                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 611
 612         target_complete_cmd(cmd, SAM_STAT_GOOD);
 613         return 0;
 614 }
 615
 616 enum {
 617         Opt_fd_dev_name, Opt_fd_dev_size, Opt_fd_buffered_io, Opt_err
 618 };
 619
 620 static match_table_t tokens = {
 621         {Opt_fd_dev_name, "fd_dev_name=%s"},
 622         {Opt_fd_dev_size, "fd_dev_size=%s"},
 623         {Opt_fd_buffered_io, "fd_buffered_io=%d"},
 624         {Opt_err, NULL}
 625 };
 626
 627 static ssize_t fd_set_configfs_dev_params(struct se_device *dev,
 628                 const char *page, ssize_t count)
 629 {
 630         struct fd_dev *fd_dev = FD_DEV(dev);
 631         char *orig, *ptr, *arg_p, *opts;
 632         substring_t args[MAX_OPT_ARGS];
 633         int ret = 0, arg, token;
 634
 635         opts = kstrdup(page, GFP_KERNEL);
 636         if (!opts)
 637                 return -ENOMEM;
 638
 639         orig = opts;
 640
 641         while ((ptr = strsep(&opts, ",\n")) != NULL) {
 642                 if (!*ptr)
 643                         continue;
 644
 645                 token = match_token(ptr, tokens, args);
 646                 switch (token) {
 647                 case Opt_fd_dev_name:
 648                         if (match_strlcpy(fd_dev->fd_dev_name, &args[0],
 649                                 FD_MAX_DEV_NAME) == 0) {
 650                                 ret = -EINVAL;
 651                                 break;
 652                         }
 653                         pr_debug("FILEIO: Referencing Path: %s\n",
 654                                         fd_dev->fd_dev_name);
 655                         fd_dev->fbd_flags |= FBDF_HAS_PATH;
 656                         break;
 657                 case Opt_fd_dev_size:
 658                         arg_p = match_strdup(&args[0]);
 659                         if (!arg_p) {
 660                                 ret = -ENOMEM;
 661                                 break;
 662                         }
 663                         ret = kstrtoull(arg_p, 0, &fd_dev->fd_dev_size);
 664                         kfree(arg_p);
 665                         if (ret < 0) {
 666                                 pr_err("kstrtoull() failed for"
 667                                                 " fd_dev_size=\n");
 668                                 goto out;
 669                         }
 670                         pr_debug("FILEIO: Referencing Size: %llu"
 671                                         " bytes\n", fd_dev->fd_dev_size);
 672                         fd_dev->fbd_flags |= FBDF_HAS_SIZE;
 673                         break;
 674                 case Opt_fd_buffered_io:
 675                         ret = match_int(args, &arg);
 676                         if (ret)
 677                                 goto out;
 678                         if (arg != 1) {
 679                                 pr_err("bogus fd_buffered_io=%d value\n", arg);
 680                                 ret = -EINVAL;
 681                                 goto out;
 682                         }
 683
 684                         pr_debug("FILEIO: Using buffered I/O"
 685                                 " operations for struct fd_dev\n");
 686
 687                         fd_dev->fbd_flags |= FDBD_HAS_BUFFERED_IO_WCE;
 688                         break;
 689                 default:
 690                         break;
 691                 }
 692         }
 693
 694 out:
 695         kfree(orig);
 696         return (!ret) ? count : ret;
 697 }
 698
 699 static ssize_t fd_show_configfs_dev_params(struct se_device *dev, char *b)
 700 {
 701         struct fd_dev *fd_dev = FD_DEV(dev);
 702         ssize_t bl = 0;
 703
 704         bl = sprintf(b + bl, "TCM FILEIO ID: %u", fd_dev->fd_dev_id);
 705         bl += sprintf(b + bl, "        File: %s  Size: %llu  Mode: %s\n",
 706                 fd_dev->fd_dev_name, fd_dev->fd_dev_size,
 707                 (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) ?
 708                 "Buffered-WCE" : "O_DSYNC");
 709         return bl;
 710 }
 711
 712 static sector_t fd_get_blocks(struct se_device *dev)
 713 {
 714         struct fd_dev *fd_dev = FD_DEV(dev);
 715         struct file *f = fd_dev->fd_file;
 716         struct inode *i = f->f_mapping->host;
 717         unsigned long long dev_size;
 718         /*
 719          * When using a file that references an underlying struct block_device,
 720          * ensure dev_size is always based on the current inode size in order
 721          * to handle underlying block_device resize operations.
 722          */
 723         if (S_ISBLK(i->i_mode))
 724                 dev_size = i_size_read(i);
 725         else
 726                 dev_size = fd_dev->fd_dev_size;
 727
 728         return div_u64(dev_size - dev->dev_attrib.block_size,
 729                        dev->dev_attrib.block_size);
 730 }
 731
 732 static int fd_init_prot(struct se_device *dev)
 733 {
 734         struct fd_dev *fd_dev = FD_DEV(dev);
 735         struct file *prot_file, *file = fd_dev->fd_file;
 736         struct inode *inode;
 737         int ret, flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
 738         char buf[FD_MAX_DEV_PROT_NAME];
 739
 740         if (!file) {
 741                 pr_err("Unable to locate fd_dev->fd_file\n");
 742                 return -ENODEV;
 743         }
 744
 745         inode = file->f_mapping->host;
 746         if (S_ISBLK(inode->i_mode)) {
 747                 pr_err("FILEIO Protection emulation only supported on"
 748                        " !S_ISBLK\n");
 749                 return -ENOSYS;
 750         }
 751
 752         if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE)
 753                 flags &= ~O_DSYNC;
 754
 755         snprintf(buf, FD_MAX_DEV_PROT_NAME, "%s.protection",
 756                  fd_dev->fd_dev_name);
 757
 758         prot_file = filp_open(buf, flags, 0600);
 759         if (IS_ERR(prot_file)) {
 760                 pr_err("filp_open(%s) failed\n", buf);
 761                 ret = PTR_ERR(prot_file);
 762                 return ret;
 763         }
 764         fd_dev->fd_prot_file = prot_file;
 765
 766         return 0;
 767 }
 768
 769 static int fd_format_prot(struct se_device *dev)
 770 {
 771         unsigned char *buf;
 772         int unit_size = FDBD_FORMAT_UNIT_SIZE * dev->dev_attrib.block_size;
 773         int ret;
 774
 775         if (!dev->dev_attrib.pi_prot_type) {
 776                 pr_err("Unable to format_prot while pi_prot_type == 0\n");
 777                 return -ENODEV;
 778         }
 779
 780         buf = vzalloc(unit_size);
 781         if (!buf) {
 782                 pr_err("Unable to allocate FILEIO prot buf\n");
 783                 return -ENOMEM;
 784         }
 785
 786         pr_debug("Using FILEIO prot_length: %llu\n",
 787                  (unsigned long long)(dev->transport->get_blocks(dev) + 1) *
 788                                         dev->prot_length);
 789
 790         memset(buf, 0xff, unit_size);
 791         ret = fd_do_prot_fill(dev, 0, dev->transport->get_blocks(dev) + 1,
 792                               buf, unit_size);
 793         vfree(buf);
 794         return ret;
 795 }
 796
 797 static void fd_free_prot(struct se_device *dev)
 798 {
 799         struct fd_dev *fd_dev = FD_DEV(dev);
 800
 801         if (!fd_dev->fd_prot_file)
 802                 return;
 803
 804         filp_close(fd_dev->fd_prot_file, NULL);
 805         fd_dev->fd_prot_file = NULL;
 806 }
 807
 808 static struct sbc_ops fd_sbc_ops = {
 809         .execute_rw             = fd_execute_rw,
 810         .execute_sync_cache     = fd_execute_sync_cache,
 811         .execute_write_same     = fd_execute_write_same,
 812         .execute_unmap          = fd_execute_unmap,
 813 };
 814
 815 static sense_reason_t
 816 fd_parse_cdb(struct se_cmd *cmd)
 817 {
 818         return sbc_parse_cdb(cmd, &fd_sbc_ops);
 819 }
 820
 821 static const struct target_backend_ops fileio_ops = {
 822         .name                   = "fileio",
 823         .inquiry_prod           = "FILEIO",
 824         .inquiry_rev            = FD_VERSION,
 825         .owner                  = THIS_MODULE,
 826         .attach_hba             = fd_attach_hba,
 827         .detach_hba             = fd_detach_hba,
 828         .alloc_device           = fd_alloc_device,
 829         .configure_device       = fd_configure_device,
 830         .free_device            = fd_free_device,
 831         .parse_cdb              = fd_parse_cdb,
 832         .set_configfs_dev_params = fd_set_configfs_dev_params,
 833         .show_configfs_dev_params = fd_show_configfs_dev_params,
 834         .get_device_type        = sbc_get_device_type,
 835         .get_blocks             = fd_get_blocks,
 836         .init_prot              = fd_init_prot,
 837         .format_prot            = fd_format_prot,
 838         .free_prot              = fd_free_prot,
 839         .tb_dev_attrib_attrs    = sbc_attrib_attrs,
 840 };
 841
 842 static int __init fileio_module_init(void)
 843 {
 844         return transport_backend_register(&fileio_ops);
 845 }
 846
 847 static void __exit fileio_module_exit(void)
 848 {
 849         target_backend_unregister(&fileio_ops);
 850 }
 851
 852 MODULE_DESCRIPTION("TCM FILEIO subsystem plugin");
 853 MODULE_AUTHOR("nab@Linux-iSCSI.org");
 854 MODULE_LICENSE("GPL");
 855
 856 module_init(fileio_module_init);
 857 module_exit(fileio_module_exit);