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                  * Check if the underlying struct block_device request_queue supports
 165                  * the QUEUE_FLAG_DISCARD bit for UNMAP/WRITE_SAME in SCSI + TRIM
 166                  * in ATA and we need to set TPE=1
 167                  */
 168                 if (blk_queue_discard(q)) {
 169                         dev->dev_attrib.max_unmap_lba_count =
 170                                 q->limits.max_discard_sectors;
 171                         /*
 172                          * Currently hardcoded to 1 in Linux/SCSI code..
 173                          */
 174                         dev->dev_attrib.max_unmap_block_desc_count = 1;
 175                         dev->dev_attrib.unmap_granularity =
 176                                 q->limits.discard_granularity >> 9;
 177                         dev->dev_attrib.unmap_granularity_alignment =
 178                                 q->limits.discard_alignment;
 179                         pr_debug("IFILE: BLOCK Discard support available,"
 180                                         " disabled by default\n");
 181                 }
 182                 /*
 183                  * Enable write same emulation for IBLOCK and use 0xFFFF as
 184                  * the smaller WRITE_SAME(10) only has a two-byte block count.
 185                  */
 186                 dev->dev_attrib.max_write_same_len = 0xFFFF;
 187
 188                 if (blk_queue_nonrot(q))
 189                         dev->dev_attrib.is_nonrot = 1;
 190         } else {
 191                 if (!(fd_dev->fbd_flags & FBDF_HAS_SIZE)) {
 192                         pr_err("FILEIO: Missing fd_dev_size="
 193                                 " parameter, and no backing struct"
 194                                 " block_device\n");
 195                         goto fail;
 196                 }
 197
 198                 fd_dev->fd_block_size = FD_BLOCKSIZE;
 199                 /*
 200                  * Limit UNMAP emulation to 8k Number of LBAs (NoLB)
 201                  */
 202                 dev->dev_attrib.max_unmap_lba_count = 0x2000;
 203                 /*
 204                  * Currently hardcoded to 1 in Linux/SCSI code..
 205                  */
 206                 dev->dev_attrib.max_unmap_block_desc_count = 1;
 207                 dev->dev_attrib.unmap_granularity = 1;
 208                 dev->dev_attrib.unmap_granularity_alignment = 0;
 209
 210                 /*
 211                  * Limit WRITE_SAME w/ UNMAP=0 emulation to 8k Number of LBAs (NoLB)
 212                  * based upon struct iovec limit for vfs_writev()
 213                  */
 214                 dev->dev_attrib.max_write_same_len = 0x1000;
 215         }
 216
 217         dev->dev_attrib.hw_block_size = fd_dev->fd_block_size;
 218         dev->dev_attrib.max_bytes_per_io = FD_MAX_BYTES;
 219         dev->dev_attrib.hw_max_sectors = FD_MAX_BYTES / fd_dev->fd_block_size;
 220         dev->dev_attrib.hw_queue_depth = FD_MAX_DEVICE_QUEUE_DEPTH;
 221
 222         if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
 223                 pr_debug("FILEIO: Forcing setting of emulate_write_cache=1"
 224                         " with FDBD_HAS_BUFFERED_IO_WCE\n");
 225                 dev->dev_attrib.emulate_write_cache = 1;
 226         }
 227
 228         fd_dev->fd_dev_id = fd_host->fd_host_dev_id_count++;
 229         fd_dev->fd_queue_depth = dev->queue_depth;
 230
 231         pr_debug("CORE_FILE[%u] - Added TCM FILEIO Device ID: %u at %s,"
 232                 " %llu total bytes\n", fd_host->fd_host_id, fd_dev->fd_dev_id,
 233                         fd_dev->fd_dev_name, fd_dev->fd_dev_size);
 234
 235         return 0;
 236 fail:
 237         if (fd_dev->fd_file) {
 238                 filp_close(fd_dev->fd_file, NULL);
 239                 fd_dev->fd_file = NULL;
 240         }
 241         return ret;
 242 }
 243
 244 static void fd_dev_call_rcu(struct rcu_head *p)
 245 {
 246         struct se_device *dev = container_of(p, struct se_device, rcu_head);
 247         struct fd_dev *fd_dev = FD_DEV(dev);
 248
 249         kfree(fd_dev);
 250 }
 251
 252 static void fd_free_device(struct se_device *dev)
 253 {
 254         struct fd_dev *fd_dev = FD_DEV(dev);
 255
 256         if (fd_dev->fd_file) {
 257                 filp_close(fd_dev->fd_file, NULL);
 258                 fd_dev->fd_file = NULL;
 259         }
 260         call_rcu(&dev->rcu_head, fd_dev_call_rcu);
 261 }
 262
 263 static int fd_do_rw(struct se_cmd *cmd, struct file *fd,
 264                     u32 block_size, struct scatterlist *sgl,
 265                     u32 sgl_nents, u32 data_length, int is_write)
 266 {
 267         struct scatterlist *sg;
 268         struct iov_iter iter;
 269         struct bio_vec *bvec;
 270         ssize_t len = 0;
 271         loff_t pos = (cmd->t_task_lba * block_size);
 272         int ret = 0, i;
 273
 274         bvec = kcalloc(sgl_nents, sizeof(struct bio_vec), GFP_KERNEL);
 275         if (!bvec) {
 276                 pr_err("Unable to allocate fd_do_readv iov[]\n");
 277                 return -ENOMEM;
 278         }
 279
 280         for_each_sg(sgl, sg, sgl_nents, i) {
 281                 bvec[i].bv_page = sg_page(sg);
 282                 bvec[i].bv_len = sg->length;
 283                 bvec[i].bv_offset = sg->offset;
 284
 285                 len += sg->length;
 286         }
 287
 288         iov_iter_bvec(&iter, ITER_BVEC, bvec, sgl_nents, len);
 289         if (is_write)
 290                 ret = vfs_iter_write(fd, &iter, &pos);
 291         else
 292                 ret = vfs_iter_read(fd, &iter, &pos);
 293
 294         kfree(bvec);
 295
 296         if (is_write) {
 297                 if (ret < 0 || ret != data_length) {
 298                         pr_err("%s() write returned %d\n", __func__, ret);
 299                         return (ret < 0 ? ret : -EINVAL);
 300                 }
 301         } else {
 302                 /*
 303                  * Return zeros and GOOD status even if the READ did not return
 304                  * the expected virt_size for struct file w/o a backing struct
 305                  * block_device.
 306                  */
 307                 if (S_ISBLK(file_inode(fd)->i_mode)) {
 308                         if (ret < 0 || ret != data_length) {
 309                                 pr_err("%s() returned %d, expecting %u for "
 310                                                 "S_ISBLK\n", __func__, ret,
 311                                                 data_length);
 312                                 return (ret < 0 ? ret : -EINVAL);
 313                         }
 314                 } else {
 315                         if (ret < 0) {
 316                                 pr_err("%s() returned %d for non S_ISBLK\n",
 317                                                 __func__, ret);
 318                                 return ret;
 319                         }
 320                 }
 321         }
 322         return 1;
 323 }
 324
 325 static sense_reason_t
 326 fd_execute_sync_cache(struct se_cmd *cmd)
 327 {
 328         struct se_device *dev = cmd->se_dev;
 329         struct fd_dev *fd_dev = FD_DEV(dev);
 330         int immed = (cmd->t_task_cdb[1] & 0x2);
 331         loff_t start, end;
 332         int ret;
 333
 334         /*
 335          * If the Immediate bit is set, queue up the GOOD response
 336          * for this SYNCHRONIZE_CACHE op
 337          */
 338         if (immed)
 339                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 340
 341         /*
 342          * Determine if we will be flushing the entire device.
 343          */
 344         if (cmd->t_task_lba == 0 && cmd->data_length == 0) {
 345                 start = 0;
 346                 end = LLONG_MAX;
 347         } else {
 348                 start = cmd->t_task_lba * dev->dev_attrib.block_size;
 349                 if (cmd->data_length)
 350                         end = start + cmd->data_length - 1;
 351                 else
 352                         end = LLONG_MAX;
 353         }
 354
 355         ret = vfs_fsync_range(fd_dev->fd_file, start, end, 1);
 356         if (ret != 0)
 357                 pr_err("FILEIO: vfs_fsync_range() failed: %d\n", ret);
 358
 359         if (immed)
 360                 return 0;
 361
 362         if (ret)
 363                 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
 364         else
 365                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 366
 367         return 0;
 368 }
 369
 370 static sense_reason_t
 371 fd_execute_write_same(struct se_cmd *cmd)
 372 {
 373         struct se_device *se_dev = cmd->se_dev;
 374         struct fd_dev *fd_dev = FD_DEV(se_dev);
 375         loff_t pos = cmd->t_task_lba * se_dev->dev_attrib.block_size;
 376         sector_t nolb = sbc_get_write_same_sectors(cmd);
 377         struct iov_iter iter;
 378         struct bio_vec *bvec;
 379         unsigned int len = 0, i;
 380         ssize_t ret;
 381
 382         if (!nolb) {
 383                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 384                 return 0;
 385         }
 386         if (cmd->prot_op) {
 387                 pr_err("WRITE_SAME: Protection information with FILEIO"
 388                        " backends not supported\n");
 389                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 390         }
 391
 392         if (cmd->t_data_nents > 1 ||
 393             cmd->t_data_sg[0].length != cmd->se_dev->dev_attrib.block_size) {
 394                 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
 395                         " block_size: %u\n",
 396                         cmd->t_data_nents,
 397                         cmd->t_data_sg[0].length,
 398                         cmd->se_dev->dev_attrib.block_size);
 399                 return TCM_INVALID_CDB_FIELD;
 400         }
 401
 402         bvec = kcalloc(nolb, sizeof(struct bio_vec), GFP_KERNEL);
 403         if (!bvec)
 404                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 405
 406         for (i = 0; i < nolb; i++) {
 407                 bvec[i].bv_page = sg_page(&cmd->t_data_sg[0]);
 408                 bvec[i].bv_len = cmd->t_data_sg[0].length;
 409                 bvec[i].bv_offset = cmd->t_data_sg[0].offset;
 410
 411                 len += se_dev->dev_attrib.block_size;
 412         }
 413
 414         iov_iter_bvec(&iter, ITER_BVEC, bvec, nolb, len);
 415         ret = vfs_iter_write(fd_dev->fd_file, &iter, &pos);
 416
 417         kfree(bvec);
 418         if (ret < 0 || ret != len) {
 419                 pr_err("vfs_iter_write() returned %zd for write same\n", ret);
 420                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 421         }
 422
 423         target_complete_cmd(cmd, SAM_STAT_GOOD);
 424         return 0;
 425 }
 426
 427 static int
 428 fd_do_prot_fill(struct se_device *se_dev, sector_t lba, sector_t nolb,
 429                 void *buf, size_t bufsize)
 430 {
 431         struct fd_dev *fd_dev = FD_DEV(se_dev);
 432         struct file *prot_fd = fd_dev->fd_prot_file;
 433         sector_t prot_length, prot;
 434         loff_t pos = lba * se_dev->prot_length;
 435
 436         if (!prot_fd) {
 437                 pr_err("Unable to locate fd_dev->fd_prot_file\n");
 438                 return -ENODEV;
 439         }
 440
 441         prot_length = nolb * se_dev->prot_length;
 442
 443         for (prot = 0; prot < prot_length;) {
 444                 sector_t len = min_t(sector_t, bufsize, prot_length - prot);
 445                 ssize_t ret = kernel_write(prot_fd, buf, len, pos + prot);
 446
 447                 if (ret != len) {
 448                         pr_err("vfs_write to prot file failed: %zd\n", ret);
 449                         return ret < 0 ? ret : -ENODEV;
 450                 }
 451                 prot += ret;
 452         }
 453
 454         return 0;
 455 }
 456
 457 static int
 458 fd_do_prot_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
 459 {
 460         void *buf;
 461         int rc;
 462
 463         buf = (void *)__get_free_page(GFP_KERNEL);
 464         if (!buf) {
 465                 pr_err("Unable to allocate FILEIO prot buf\n");
 466                 return -ENOMEM;
 467         }
 468         memset(buf, 0xff, PAGE_SIZE);
 469
 470         rc = fd_do_prot_fill(cmd->se_dev, lba, nolb, buf, PAGE_SIZE);
 471
 472         free_page((unsigned long)buf);
 473
 474         return rc;
 475 }
 476
 477 static sense_reason_t
 478 fd_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
 479 {
 480         struct file *file = FD_DEV(cmd->se_dev)->fd_file;
 481         struct inode *inode = file->f_mapping->host;
 482         int ret;
 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
 494                 ret = blkdev_issue_discard(bdev, lba,
 495                                 nolb, GFP_KERNEL, 0);
 496                 if (ret < 0) {
 497                         pr_warn("FILEIO: blkdev_issue_discard() failed: %d\n",
 498                                 ret);
 499                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 500                 }
 501         } else {
 502                 /* The backend is normal file, use fallocate */
 503                 struct se_device *se_dev = cmd->se_dev;
 504                 loff_t pos = lba * se_dev->dev_attrib.block_size;
 505                 unsigned int len = nolb * se_dev->dev_attrib.block_size;
 506                 int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
 507
 508                 if (!file->f_op->fallocate)
 509                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 510
 511                 ret = file->f_op->fallocate(file, mode, pos, len);
 512                 if (ret < 0) {
 513                         pr_warn("FILEIO: fallocate() failed: %d\n", ret);
 514                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 515                 }
 516         }
 517
 518         return 0;
 519 }
 520
 521 static sense_reason_t
 522 fd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 523               enum dma_data_direction data_direction)
 524 {
 525         struct se_device *dev = cmd->se_dev;
 526         struct fd_dev *fd_dev = FD_DEV(dev);
 527         struct file *file = fd_dev->fd_file;
 528         struct file *pfile = fd_dev->fd_prot_file;
 529         sense_reason_t rc;
 530         int ret = 0;
 531         /*
 532          * We are currently limited by the number of iovecs (2048) per
 533          * single vfs_[writev,readv] call.
 534          */
 535         if (cmd->data_length > FD_MAX_BYTES) {
 536                 pr_err("FILEIO: Not able to process I/O of %u bytes due to"
 537                        "FD_MAX_BYTES: %u iovec count limitiation\n",
 538                         cmd->data_length, FD_MAX_BYTES);
 539                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 540         }
 541         /*
 542          * Call vectorized fileio functions to map struct scatterlist
 543          * physical memory addresses to struct iovec virtual memory.
 544          */
 545         if (data_direction == DMA_FROM_DEVICE) {
 546                 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 547                         ret = fd_do_rw(cmd, pfile, dev->prot_length,
 548                                        cmd->t_prot_sg, cmd->t_prot_nents,
 549                                        cmd->prot_length, 0);
 550                         if (ret < 0)
 551                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 552                 }
 553
 554                 ret = fd_do_rw(cmd, file, dev->dev_attrib.block_size,
 555                                sgl, sgl_nents, cmd->data_length, 0);
 556
 557                 if (ret > 0 && cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 558                         u32 sectors = cmd->data_length >>
 559                                         ilog2(dev->dev_attrib.block_size);
 560
 561                         rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors,
 562                                             0, cmd->t_prot_sg, 0);
 563                         if (rc)
 564                                 return rc;
 565                 }
 566         } else {
 567                 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 568                         u32 sectors = cmd->data_length >>
 569                                         ilog2(dev->dev_attrib.block_size);
 570
 571                         rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors,
 572                                             0, cmd->t_prot_sg, 0);
 573                         if (rc)
 574                                 return rc;
 575                 }
 576
 577                 ret = fd_do_rw(cmd, file, dev->dev_attrib.block_size,
 578                                sgl, sgl_nents, cmd->data_length, 1);
 579                 /*
 580                  * Perform implicit vfs_fsync_range() for fd_do_writev() ops
 581                  * for SCSI WRITEs with Forced Unit Access (FUA) set.
 582                  * Allow this to happen independent of WCE=0 setting.
 583                  */
 584                 if (ret > 0 && (cmd->se_cmd_flags & SCF_FUA)) {
 585                         loff_t start = cmd->t_task_lba *
 586                                 dev->dev_attrib.block_size;
 587                         loff_t end;
 588
 589                         if (cmd->data_length)
 590                                 end = start + cmd->data_length - 1;
 591                         else
 592                                 end = LLONG_MAX;
 593
 594                         vfs_fsync_range(fd_dev->fd_file, start, end, 1);
 595                 }
 596
 597                 if (ret > 0 && cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 598                         ret = fd_do_rw(cmd, pfile, dev->prot_length,
 599                                        cmd->t_prot_sg, cmd->t_prot_nents,
 600                                        cmd->prot_length, 1);
 601                         if (ret < 0)
 602                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 603                 }
 604         }
 605
 606         if (ret < 0)
 607                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 608
 609         if (ret)
 610                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 611         return 0;
 612 }
 613
 614 enum {
 615         Opt_fd_dev_name, Opt_fd_dev_size, Opt_fd_buffered_io, Opt_err
 616 };
 617
 618 static match_table_t tokens = {
 619         {Opt_fd_dev_name, "fd_dev_name=%s"},
 620         {Opt_fd_dev_size, "fd_dev_size=%s"},
 621         {Opt_fd_buffered_io, "fd_buffered_io=%d"},
 622         {Opt_err, NULL}
 623 };
 624
 625 static ssize_t fd_set_configfs_dev_params(struct se_device *dev,
 626                 const char *page, ssize_t count)
 627 {
 628         struct fd_dev *fd_dev = FD_DEV(dev);
 629         char *orig, *ptr, *arg_p, *opts;
 630         substring_t args[MAX_OPT_ARGS];
 631         int ret = 0, arg, token;
 632
 633         opts = kstrdup(page, GFP_KERNEL);
 634         if (!opts)
 635                 return -ENOMEM;
 636
 637         orig = opts;
 638
 639         while ((ptr = strsep(&opts, ",\n")) != NULL) {
 640                 if (!*ptr)
 641                         continue;
 642
 643                 token = match_token(ptr, tokens, args);
 644                 switch (token) {
 645                 case Opt_fd_dev_name:
 646                         if (match_strlcpy(fd_dev->fd_dev_name, &args[0],
 647                                 FD_MAX_DEV_NAME) == 0) {
 648                                 ret = -EINVAL;
 649                                 break;
 650                         }
 651                         pr_debug("FILEIO: Referencing Path: %s\n",
 652                                         fd_dev->fd_dev_name);
 653                         fd_dev->fbd_flags |= FBDF_HAS_PATH;
 654                         break;
 655                 case Opt_fd_dev_size:
 656                         arg_p = match_strdup(&args[0]);
 657                         if (!arg_p) {
 658                                 ret = -ENOMEM;
 659                                 break;
 660                         }
 661                         ret = kstrtoull(arg_p, 0, &fd_dev->fd_dev_size);
 662                         kfree(arg_p);
 663                         if (ret < 0) {
 664                                 pr_err("kstrtoull() failed for"
 665                                                 " fd_dev_size=\n");
 666                                 goto out;
 667                         }
 668                         pr_debug("FILEIO: Referencing Size: %llu"
 669                                         " bytes\n", fd_dev->fd_dev_size);
 670                         fd_dev->fbd_flags |= FBDF_HAS_SIZE;
 671                         break;
 672                 case Opt_fd_buffered_io:
 673                         ret = match_int(args, &arg);
 674                         if (ret)
 675                                 goto out;
 676                         if (arg != 1) {
 677                                 pr_err("bogus fd_buffered_io=%d value\n", arg);
 678                                 ret = -EINVAL;
 679                                 goto out;
 680                         }
 681
 682                         pr_debug("FILEIO: Using buffered I/O"
 683                                 " operations for struct fd_dev\n");
 684
 685                         fd_dev->fbd_flags |= FDBD_HAS_BUFFERED_IO_WCE;
 686                         break;
 687                 default:
 688                         break;
 689                 }
 690         }
 691
 692 out:
 693         kfree(orig);
 694         return (!ret) ? count : ret;
 695 }
 696
 697 static ssize_t fd_show_configfs_dev_params(struct se_device *dev, char *b)
 698 {
 699         struct fd_dev *fd_dev = FD_DEV(dev);
 700         ssize_t bl = 0;
 701
 702         bl = sprintf(b + bl, "TCM FILEIO ID: %u", fd_dev->fd_dev_id);
 703         bl += sprintf(b + bl, "        File: %s  Size: %llu  Mode: %s\n",
 704                 fd_dev->fd_dev_name, fd_dev->fd_dev_size,
 705                 (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) ?
 706                 "Buffered-WCE" : "O_DSYNC");
 707         return bl;
 708 }
 709
 710 static sector_t fd_get_blocks(struct se_device *dev)
 711 {
 712         struct fd_dev *fd_dev = FD_DEV(dev);
 713         struct file *f = fd_dev->fd_file;
 714         struct inode *i = f->f_mapping->host;
 715         unsigned long long dev_size;
 716         /*
 717          * When using a file that references an underlying struct block_device,
 718          * ensure dev_size is always based on the current inode size in order
 719          * to handle underlying block_device resize operations.
 720          */
 721         if (S_ISBLK(i->i_mode))
 722                 dev_size = i_size_read(i);
 723         else
 724                 dev_size = fd_dev->fd_dev_size;
 725
 726         return div_u64(dev_size - dev->dev_attrib.block_size,
 727                        dev->dev_attrib.block_size);
 728 }
 729
 730 static int fd_init_prot(struct se_device *dev)
 731 {
 732         struct fd_dev *fd_dev = FD_DEV(dev);
 733         struct file *prot_file, *file = fd_dev->fd_file;
 734         struct inode *inode;
 735         int ret, flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
 736         char buf[FD_MAX_DEV_PROT_NAME];
 737
 738         if (!file) {
 739                 pr_err("Unable to locate fd_dev->fd_file\n");
 740                 return -ENODEV;
 741         }
 742
 743         inode = file->f_mapping->host;
 744         if (S_ISBLK(inode->i_mode)) {
 745                 pr_err("FILEIO Protection emulation only supported on"
 746                        " !S_ISBLK\n");
 747                 return -ENOSYS;
 748         }
 749
 750         if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE)
 751                 flags &= ~O_DSYNC;
 752
 753         snprintf(buf, FD_MAX_DEV_PROT_NAME, "%s.protection",
 754                  fd_dev->fd_dev_name);
 755
 756         prot_file = filp_open(buf, flags, 0600);
 757         if (IS_ERR(prot_file)) {
 758                 pr_err("filp_open(%s) failed\n", buf);
 759                 ret = PTR_ERR(prot_file);
 760                 return ret;
 761         }
 762         fd_dev->fd_prot_file = prot_file;
 763
 764         return 0;
 765 }
 766
 767 static int fd_format_prot(struct se_device *dev)
 768 {
 769         unsigned char *buf;
 770         int unit_size = FDBD_FORMAT_UNIT_SIZE * dev->dev_attrib.block_size;
 771         int ret;
 772
 773         if (!dev->dev_attrib.pi_prot_type) {
 774                 pr_err("Unable to format_prot while pi_prot_type == 0\n");
 775                 return -ENODEV;
 776         }
 777
 778         buf = vzalloc(unit_size);
 779         if (!buf) {
 780                 pr_err("Unable to allocate FILEIO prot buf\n");
 781                 return -ENOMEM;
 782         }
 783
 784         pr_debug("Using FILEIO prot_length: %llu\n",
 785                  (unsigned long long)(dev->transport->get_blocks(dev) + 1) *
 786                                         dev->prot_length);
 787
 788         memset(buf, 0xff, unit_size);
 789         ret = fd_do_prot_fill(dev, 0, dev->transport->get_blocks(dev) + 1,
 790                               buf, unit_size);
 791         vfree(buf);
 792         return ret;
 793 }
 794
 795 static void fd_free_prot(struct se_device *dev)
 796 {
 797         struct fd_dev *fd_dev = FD_DEV(dev);
 798
 799         if (!fd_dev->fd_prot_file)
 800                 return;
 801
 802         filp_close(fd_dev->fd_prot_file, NULL);
 803         fd_dev->fd_prot_file = NULL;
 804 }
 805
 806 static struct sbc_ops fd_sbc_ops = {
 807         .execute_rw             = fd_execute_rw,
 808         .execute_sync_cache     = fd_execute_sync_cache,
 809         .execute_write_same     = fd_execute_write_same,
 810         .execute_unmap          = fd_execute_unmap,
 811 };
 812
 813 static sense_reason_t
 814 fd_parse_cdb(struct se_cmd *cmd)
 815 {
 816         return sbc_parse_cdb(cmd, &fd_sbc_ops);
 817 }
 818
 819 static const struct target_backend_ops fileio_ops = {
 820         .name                   = "fileio",
 821         .inquiry_prod           = "FILEIO",
 822         .inquiry_rev            = FD_VERSION,
 823         .owner                  = THIS_MODULE,
 824         .attach_hba             = fd_attach_hba,
 825         .detach_hba             = fd_detach_hba,
 826         .alloc_device           = fd_alloc_device,
 827         .configure_device       = fd_configure_device,
 828         .free_device            = fd_free_device,
 829         .parse_cdb              = fd_parse_cdb,
 830         .set_configfs_dev_params = fd_set_configfs_dev_params,
 831         .show_configfs_dev_params = fd_show_configfs_dev_params,
 832         .get_device_type        = sbc_get_device_type,
 833         .get_blocks             = fd_get_blocks,
 834         .init_prot              = fd_init_prot,
 835         .format_prot            = fd_format_prot,
 836         .free_prot              = fd_free_prot,
 837         .tb_dev_attrib_attrs    = sbc_attrib_attrs,
 838 };
 839
 840 static int __init fileio_module_init(void)
 841 {
 842         return transport_backend_register(&fileio_ops);
 843 }
 844
 845 static void __exit fileio_module_exit(void)
 846 {
 847         target_backend_unregister(&fileio_ops);
 848 }
 849
 850 MODULE_DESCRIPTION("TCM FILEIO subsystem plugin");
 851 MODULE_AUTHOR("nab@Linux-iSCSI.org");
 852 MODULE_LICENSE("GPL");
 853
 854 module_init(fileio_module_init);
 855 module_exit(fileio_module_exit);