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 <linux/uio.h>
  36 #include <scsi/scsi_proto.h>
  37 #include <asm/unaligned.h>
  38
  39 #include <target/target_core_base.h>
  40 #include <target/target_core_backend.h>
  41
  42 #include "target_core_file.h"
  43
  44 static inline struct fd_dev *FD_DEV(struct se_device *dev)
  45 {
  46         return container_of(dev, struct fd_dev, dev);
  47 }
  48
  49 static int fd_attach_hba(struct se_hba *hba, u32 host_id)
  50 {
  51         struct fd_host *fd_host;
  52
  53         fd_host = kzalloc(sizeof(struct fd_host), GFP_KERNEL);
  54         if (!fd_host) {
  55                 pr_err("Unable to allocate memory for struct fd_host\n");
  56                 return -ENOMEM;
  57         }
  58
  59         fd_host->fd_host_id = host_id;
  60
  61         hba->hba_ptr = fd_host;
  62
  63         pr_debug("CORE_HBA[%d] - TCM FILEIO HBA Driver %s on Generic"
  64                 " Target Core Stack %s\n", hba->hba_id, FD_VERSION,
  65                 TARGET_CORE_VERSION);
  66         pr_debug("CORE_HBA[%d] - Attached FILEIO HBA: %u to Generic\n",
  67                 hba->hba_id, fd_host->fd_host_id);
  68
  69         return 0;
  70 }
  71
  72 static void fd_detach_hba(struct se_hba *hba)
  73 {
  74         struct fd_host *fd_host = hba->hba_ptr;
  75
  76         pr_debug("CORE_HBA[%d] - Detached FILEIO HBA: %u from Generic"
  77                 " Target Core\n", hba->hba_id, fd_host->fd_host_id);
  78
  79         kfree(fd_host);
  80         hba->hba_ptr = NULL;
  81 }
  82
  83 static struct se_device *fd_alloc_device(struct se_hba *hba, const char *name)
  84 {
  85         struct fd_dev *fd_dev;
  86         struct fd_host *fd_host = hba->hba_ptr;
  87
  88         fd_dev = kzalloc(sizeof(struct fd_dev), GFP_KERNEL);
  89         if (!fd_dev) {
  90                 pr_err("Unable to allocate memory for struct fd_dev\n");
  91                 return NULL;
  92         }
  93
  94         fd_dev->fd_host = fd_host;
  95
  96         pr_debug("FILEIO: Allocated fd_dev for %p\n", name);
  97
  98         return &fd_dev->dev;
  99 }
 100
 101 static int fd_configure_device(struct se_device *dev)
 102 {
 103         struct fd_dev *fd_dev = FD_DEV(dev);
 104         struct fd_host *fd_host = dev->se_hba->hba_ptr;
 105         struct file *file;
 106         struct inode *inode = NULL;
 107         int flags, ret = -EINVAL;
 108
 109         if (!(fd_dev->fbd_flags & FBDF_HAS_PATH)) {
 110                 pr_err("Missing fd_dev_name=\n");
 111                 return -EINVAL;
 112         }
 113
 114         /*
 115          * Use O_DSYNC by default instead of O_SYNC to forgo syncing
 116          * of pure timestamp updates.
 117          */
 118         flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
 119
 120         /*
 121          * Optionally allow fd_buffered_io=1 to be enabled for people
 122          * who want use the fs buffer cache as an WriteCache mechanism.
 123          *
 124          * This means that in event of a hard failure, there is a risk
 125          * of silent data-loss if the SCSI client has *not* performed a
 126          * forced unit access (FUA) write, or issued SYNCHRONIZE_CACHE
 127          * to write-out the entire device cache.
 128          */
 129         if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
 130                 pr_debug("FILEIO: Disabling O_DSYNC, using buffered FILEIO\n");
 131                 flags &= ~O_DSYNC;
 132         }
 133
 134         file = filp_open(fd_dev->fd_dev_name, flags, 0600);
 135         if (IS_ERR(file)) {
 136                 pr_err("filp_open(%s) failed\n", fd_dev->fd_dev_name);
 137                 ret = PTR_ERR(file);
 138                 goto fail;
 139         }
 140         fd_dev->fd_file = file;
 141         /*
 142          * If using a block backend with this struct file, we extract
 143          * fd_dev->fd_[block,dev]_size from struct block_device.
 144          *
 145          * Otherwise, we use the passed fd_size= from configfs
 146          */
 147         inode = file->f_mapping->host;
 148         if (S_ISBLK(inode->i_mode)) {
 149                 struct request_queue *q = bdev_get_queue(inode->i_bdev);
 150                 unsigned long long dev_size;
 151
 152                 fd_dev->fd_block_size = bdev_logical_block_size(inode->i_bdev);
 153                 /*
 154                  * Determine the number of bytes from i_size_read() minus
 155                  * one (1) logical sector from underlying struct block_device
 156                  */
 157                 dev_size = (i_size_read(file->f_mapping->host) -
 158                                        fd_dev->fd_block_size);
 159
 160                 pr_debug("FILEIO: Using size: %llu bytes from struct"
 161                         " block_device blocks: %llu logical_block_size: %d\n",
 162                         dev_size, div_u64(dev_size, fd_dev->fd_block_size),
 163                         fd_dev->fd_block_size);
 164
 165                 if (target_configure_unmap_from_queue(&dev->dev_attrib, q))
 166                         pr_debug("IFILE: BLOCK Discard support available,"
 167                                  " disabled by default\n");
 168                 /*
 169                  * Enable write same emulation for IBLOCK and use 0xFFFF as
 170                  * the smaller WRITE_SAME(10) only has a two-byte block count.
 171                  */
 172                 dev->dev_attrib.max_write_same_len = 0xFFFF;
 173
 174                 if (blk_queue_nonrot(q))
 175                         dev->dev_attrib.is_nonrot = 1;
 176         } else {
 177                 if (!(fd_dev->fbd_flags & FBDF_HAS_SIZE)) {
 178                         pr_err("FILEIO: Missing fd_dev_size="
 179                                 " parameter, and no backing struct"
 180                                 " block_device\n");
 181                         goto fail;
 182                 }
 183
 184                 fd_dev->fd_block_size = FD_BLOCKSIZE;
 185                 /*
 186                  * Limit UNMAP emulation to 8k Number of LBAs (NoLB)
 187                  */
 188                 dev->dev_attrib.max_unmap_lba_count = 0x2000;
 189                 /*
 190                  * Currently hardcoded to 1 in Linux/SCSI code..
 191                  */
 192                 dev->dev_attrib.max_unmap_block_desc_count = 1;
 193                 dev->dev_attrib.unmap_granularity = 1;
 194                 dev->dev_attrib.unmap_granularity_alignment = 0;
 195
 196                 /*
 197                  * Limit WRITE_SAME w/ UNMAP=0 emulation to 8k Number of LBAs (NoLB)
 198                  * based upon struct iovec limit for vfs_writev()
 199                  */
 200                 dev->dev_attrib.max_write_same_len = 0x1000;
 201         }
 202
 203         dev->dev_attrib.hw_block_size = fd_dev->fd_block_size;
 204         dev->dev_attrib.max_bytes_per_io = FD_MAX_BYTES;
 205         dev->dev_attrib.hw_max_sectors = FD_MAX_BYTES / fd_dev->fd_block_size;
 206         dev->dev_attrib.hw_queue_depth = FD_MAX_DEVICE_QUEUE_DEPTH;
 207
 208         if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
 209                 pr_debug("FILEIO: Forcing setting of emulate_write_cache=1"
 210                         " with FDBD_HAS_BUFFERED_IO_WCE\n");
 211                 dev->dev_attrib.emulate_write_cache = 1;
 212         }
 213
 214         fd_dev->fd_dev_id = fd_host->fd_host_dev_id_count++;
 215         fd_dev->fd_queue_depth = dev->queue_depth;
 216
 217         pr_debug("CORE_FILE[%u] - Added TCM FILEIO Device ID: %u at %s,"
 218                 " %llu total bytes\n", fd_host->fd_host_id, fd_dev->fd_dev_id,
 219                         fd_dev->fd_dev_name, fd_dev->fd_dev_size);
 220
 221         return 0;
 222 fail:
 223         if (fd_dev->fd_file) {
 224                 filp_close(fd_dev->fd_file, NULL);
 225                 fd_dev->fd_file = NULL;
 226         }
 227         return ret;
 228 }
 229
 230 static void fd_dev_call_rcu(struct rcu_head *p)
 231 {
 232         struct se_device *dev = container_of(p, struct se_device, rcu_head);
 233         struct fd_dev *fd_dev = FD_DEV(dev);
 234
 235         kfree(fd_dev);
 236 }
 237
 238 static void fd_free_device(struct se_device *dev)
 239 {
 240         call_rcu(&dev->rcu_head, fd_dev_call_rcu);
 241 }
 242
 243 static void fd_destroy_device(struct se_device *dev)
 244 {
 245         struct fd_dev *fd_dev = FD_DEV(dev);
 246
 247         if (fd_dev->fd_file) {
 248                 filp_close(fd_dev->fd_file, NULL);
 249                 fd_dev->fd_file = NULL;
 250         }
 251 }
 252
 253 static int fd_do_rw(struct se_cmd *cmd, struct file *fd,
 254                     u32 block_size, struct scatterlist *sgl,
 255                     u32 sgl_nents, u32 data_length, int is_write)
 256 {
 257         struct scatterlist *sg;
 258         struct iov_iter iter;
 259         struct bio_vec *bvec;
 260         ssize_t len = 0;
 261         loff_t pos = (cmd->t_task_lba * block_size);
 262         int ret = 0, i;
 263
 264         bvec = kcalloc(sgl_nents, sizeof(struct bio_vec), GFP_KERNEL);
 265         if (!bvec) {
 266                 pr_err("Unable to allocate fd_do_readv iov[]\n");
 267                 return -ENOMEM;
 268         }
 269
 270         for_each_sg(sgl, sg, sgl_nents, i) {
 271                 bvec[i].bv_page = sg_page(sg);
 272                 bvec[i].bv_len = sg->length;
 273                 bvec[i].bv_offset = sg->offset;
 274
 275                 len += sg->length;
 276         }
 277
 278         iov_iter_bvec(&iter, ITER_BVEC, bvec, sgl_nents, len);
 279         if (is_write)
 280                 ret = vfs_iter_write(fd, &iter, &pos, 0);
 281         else
 282                 ret = vfs_iter_read(fd, &iter, &pos, 0);
 283
 284         if (is_write) {
 285                 if (ret < 0 || ret != data_length) {
 286                         pr_err("%s() write returned %d\n", __func__, ret);
 287                         if (ret >= 0)
 288                                 ret = -EINVAL;
 289                 }
 290         } else {
 291                 /*
 292                  * Return zeros and GOOD status even if the READ did not return
 293                  * the expected virt_size for struct file w/o a backing struct
 294                  * block_device.
 295                  */
 296                 if (S_ISBLK(file_inode(fd)->i_mode)) {
 297                         if (ret < 0 || ret != data_length) {
 298                                 pr_err("%s() returned %d, expecting %u for "
 299                                                 "S_ISBLK\n", __func__, ret,
 300                                                 data_length);
 301                                 if (ret >= 0)
 302                                         ret = -EINVAL;
 303                         }
 304                 } else {
 305                         if (ret < 0) {
 306                                 pr_err("%s() returned %d for non S_ISBLK\n",
 307                                                 __func__, ret);
 308                         } else if (ret != data_length) {
 309                                 /*
 310                                  * Short read case:
 311                                  * Probably some one truncate file under us.
 312                                  * We must explicitly zero sg-pages to prevent
 313                                  * expose uninizialized pages to userspace.
 314                                  */
 315                                 if (ret < data_length)
 316                                         ret += iov_iter_zero(data_length - ret, &iter);
 317                                 else
 318                                         ret = -EINVAL;
 319                         }
 320                 }
 321         }
 322         kfree(bvec);
 323         return ret;
 324 }
 325
 326 static sense_reason_t
 327 fd_execute_sync_cache(struct se_cmd *cmd)
 328 {
 329         struct se_device *dev = cmd->se_dev;
 330         struct fd_dev *fd_dev = FD_DEV(dev);
 331         int immed = (cmd->t_task_cdb[1] & 0x2);
 332         loff_t start, end;
 333         int ret;
 334
 335         /*
 336          * If the Immediate bit is set, queue up the GOOD response
 337          * for this SYNCHRONIZE_CACHE op
 338          */
 339         if (immed)
 340                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 341
 342         /*
 343          * Determine if we will be flushing the entire device.
 344          */
 345         if (cmd->t_task_lba == 0 && cmd->data_length == 0) {
 346                 start = 0;
 347                 end = LLONG_MAX;
 348         } else {
 349                 start = cmd->t_task_lba * dev->dev_attrib.block_size;
 350                 if (cmd->data_length)
 351                         end = start + cmd->data_length - 1;
 352                 else
 353                         end = LLONG_MAX;
 354         }
 355
 356         ret = vfs_fsync_range(fd_dev->fd_file, start, end, 1);
 357         if (ret != 0)
 358                 pr_err("FILEIO: vfs_fsync_range() failed: %d\n", ret);
 359
 360         if (immed)
 361                 return 0;
 362
 363         if (ret)
 364                 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
 365         else
 366                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 367
 368         return 0;
 369 }
 370
 371 static sense_reason_t
 372 fd_execute_write_same(struct se_cmd *cmd)
 373 {
 374         struct se_device *se_dev = cmd->se_dev;
 375         struct fd_dev *fd_dev = FD_DEV(se_dev);
 376         loff_t pos = cmd->t_task_lba * se_dev->dev_attrib.block_size;
 377         sector_t nolb = sbc_get_write_same_sectors(cmd);
 378         struct iov_iter iter;
 379         struct bio_vec *bvec;
 380         unsigned int len = 0, i;
 381         ssize_t ret;
 382
 383         if (!nolb) {
 384                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 385                 return 0;
 386         }
 387         if (cmd->prot_op) {
 388                 pr_err("WRITE_SAME: Protection information with FILEIO"
 389                        " backends not supported\n");
 390                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 391         }
 392
 393         if (cmd->t_data_nents > 1 ||
 394             cmd->t_data_sg[0].length != cmd->se_dev->dev_attrib.block_size) {
 395                 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
 396                         " block_size: %u\n",
 397                         cmd->t_data_nents,
 398                         cmd->t_data_sg[0].length,
 399                         cmd->se_dev->dev_attrib.block_size);
 400                 return TCM_INVALID_CDB_FIELD;
 401         }
 402
 403         bvec = kcalloc(nolb, sizeof(struct bio_vec), GFP_KERNEL);
 404         if (!bvec)
 405                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 406
 407         for (i = 0; i < nolb; i++) {
 408                 bvec[i].bv_page = sg_page(&cmd->t_data_sg[0]);
 409                 bvec[i].bv_len = cmd->t_data_sg[0].length;
 410                 bvec[i].bv_offset = cmd->t_data_sg[0].offset;
 411
 412                 len += se_dev->dev_attrib.block_size;
 413         }
 414
 415         iov_iter_bvec(&iter, ITER_BVEC, bvec, nolb, len);
 416         ret = vfs_iter_write(fd_dev->fd_file, &iter, &pos, 0);
 417
 418         kfree(bvec);
 419         if (ret < 0 || ret != len) {
 420                 pr_err("vfs_iter_write() returned %zd for write same\n", ret);
 421                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 422         }
 423
 424         target_complete_cmd(cmd, SAM_STAT_GOOD);
 425         return 0;
 426 }
 427
 428 static int
 429 fd_do_prot_fill(struct se_device *se_dev, sector_t lba, sector_t nolb,
 430                 void *buf, size_t bufsize)
 431 {
 432         struct fd_dev *fd_dev = FD_DEV(se_dev);
 433         struct file *prot_fd = fd_dev->fd_prot_file;
 434         sector_t prot_length, prot;
 435         loff_t pos = lba * se_dev->prot_length;
 436
 437         if (!prot_fd) {
 438                 pr_err("Unable to locate fd_dev->fd_prot_file\n");
 439                 return -ENODEV;
 440         }
 441
 442         prot_length = nolb * se_dev->prot_length;
 443
 444         for (prot = 0; prot < prot_length;) {
 445                 sector_t len = min_t(sector_t, bufsize, prot_length - prot);
 446                 ssize_t ret = kernel_write(prot_fd, buf, len, &pos);
 447
 448                 if (ret != len) {
 449                         pr_err("vfs_write to prot file failed: %zd\n", ret);
 450                         return ret < 0 ? ret : -ENODEV;
 451                 }
 452                 prot += ret;
 453         }
 454
 455         return 0;
 456 }
 457
 458 static int
 459 fd_do_prot_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
 460 {
 461         void *buf;
 462         int rc;
 463
 464         buf = (void *)__get_free_page(GFP_KERNEL);
 465         if (!buf) {
 466                 pr_err("Unable to allocate FILEIO prot buf\n");
 467                 return -ENOMEM;
 468         }
 469         memset(buf, 0xff, PAGE_SIZE);
 470
 471         rc = fd_do_prot_fill(cmd->se_dev, lba, nolb, buf, PAGE_SIZE);
 472
 473         free_page((unsigned long)buf);
 474
 475         return rc;
 476 }
 477
 478 static sense_reason_t
 479 fd_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
 480 {
 481         struct file *file = FD_DEV(cmd->se_dev)->fd_file;
 482         struct inode *inode = file->f_mapping->host;
 483         int ret;
 484
 485         if (!nolb) {
 486                 return 0;
 487         }
 488
 489         if (cmd->se_dev->dev_attrib.pi_prot_type) {
 490                 ret = fd_do_prot_unmap(cmd, lba, nolb);
 491                 if (ret)
 492                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 493         }
 494
 495         if (S_ISBLK(inode->i_mode)) {
 496                 /* The backend is block device, use discard */
 497                 struct block_device *bdev = inode->i_bdev;
 498                 struct se_device *dev = cmd->se_dev;
 499
 500                 ret = blkdev_issue_discard(bdev,
 501                                            target_to_linux_sector(dev, lba),
 502                                            target_to_linux_sector(dev,  nolb),
 503                                            GFP_KERNEL, 0);
 504                 if (ret < 0) {
 505                         pr_warn("FILEIO: blkdev_issue_discard() failed: %d\n",
 506                                 ret);
 507                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 508                 }
 509         } else {
 510                 /* The backend is normal file, use fallocate */
 511                 struct se_device *se_dev = cmd->se_dev;
 512                 loff_t pos = lba * se_dev->dev_attrib.block_size;
 513                 unsigned int len = nolb * se_dev->dev_attrib.block_size;
 514                 int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
 515
 516                 if (!file->f_op->fallocate)
 517                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 518
 519                 ret = file->f_op->fallocate(file, mode, pos, len);
 520                 if (ret < 0) {
 521                         pr_warn("FILEIO: fallocate() failed: %d\n", ret);
 522                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 523                 }
 524         }
 525
 526         return 0;
 527 }
 528
 529 static sense_reason_t
 530 fd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 531               enum dma_data_direction data_direction)
 532 {
 533         struct se_device *dev = cmd->se_dev;
 534         struct fd_dev *fd_dev = FD_DEV(dev);
 535         struct file *file = fd_dev->fd_file;
 536         struct file *pfile = fd_dev->fd_prot_file;
 537         sense_reason_t rc;
 538         int ret = 0;
 539         /*
 540          * We are currently limited by the number of iovecs (2048) per
 541          * single vfs_[writev,readv] call.
 542          */
 543         if (cmd->data_length > FD_MAX_BYTES) {
 544                 pr_err("FILEIO: Not able to process I/O of %u bytes due to"
 545                        "FD_MAX_BYTES: %u iovec count limitation\n",
 546                         cmd->data_length, FD_MAX_BYTES);
 547                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 548         }
 549         /*
 550          * Call vectorized fileio functions to map struct scatterlist
 551          * physical memory addresses to struct iovec virtual memory.
 552          */
 553         if (data_direction == DMA_FROM_DEVICE) {
 554                 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 555                         ret = fd_do_rw(cmd, pfile, dev->prot_length,
 556                                        cmd->t_prot_sg, cmd->t_prot_nents,
 557                                        cmd->prot_length, 0);
 558                         if (ret < 0)
 559                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 560                 }
 561
 562                 ret = fd_do_rw(cmd, file, dev->dev_attrib.block_size,
 563                                sgl, sgl_nents, cmd->data_length, 0);
 564
 565                 if (ret > 0 && cmd->prot_type && dev->dev_attrib.pi_prot_type &&
 566                     dev->dev_attrib.pi_prot_verify) {
 567                         u32 sectors = cmd->data_length >>
 568                                         ilog2(dev->dev_attrib.block_size);
 569
 570                         rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors,
 571                                             0, cmd->t_prot_sg, 0);
 572                         if (rc)
 573                                 return rc;
 574                 }
 575         } else {
 576                 if (cmd->prot_type && dev->dev_attrib.pi_prot_type &&
 577                     dev->dev_attrib.pi_prot_verify) {
 578                         u32 sectors = cmd->data_length >>
 579                                         ilog2(dev->dev_attrib.block_size);
 580
 581                         rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors,
 582                                             0, cmd->t_prot_sg, 0);
 583                         if (rc)
 584                                 return rc;
 585                 }
 586
 587                 ret = fd_do_rw(cmd, file, dev->dev_attrib.block_size,
 588                                sgl, sgl_nents, cmd->data_length, 1);
 589                 /*
 590                  * Perform implicit vfs_fsync_range() for fd_do_writev() ops
 591                  * for SCSI WRITEs with Forced Unit Access (FUA) set.
 592                  * Allow this to happen independent of WCE=0 setting.
 593                  */
 594                 if (ret > 0 && (cmd->se_cmd_flags & SCF_FUA)) {
 595                         loff_t start = cmd->t_task_lba *
 596                                 dev->dev_attrib.block_size;
 597                         loff_t end;
 598
 599                         if (cmd->data_length)
 600                                 end = start + cmd->data_length - 1;
 601                         else
 602                                 end = LLONG_MAX;
 603
 604                         vfs_fsync_range(fd_dev->fd_file, start, end, 1);
 605                 }
 606
 607                 if (ret > 0 && cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 608                         ret = fd_do_rw(cmd, pfile, dev->prot_length,
 609                                        cmd->t_prot_sg, cmd->t_prot_nents,
 610                                        cmd->prot_length, 1);
 611                         if (ret < 0)
 612                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 613                 }
 614         }
 615
 616         if (ret < 0)
 617                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 618
 619         target_complete_cmd(cmd, SAM_STAT_GOOD);
 620         return 0;
 621 }
 622
 623 enum {
 624         Opt_fd_dev_name, Opt_fd_dev_size, Opt_fd_buffered_io, Opt_err
 625 };
 626
 627 static match_table_t tokens = {
 628         {Opt_fd_dev_name, "fd_dev_name=%s"},
 629         {Opt_fd_dev_size, "fd_dev_size=%s"},
 630         {Opt_fd_buffered_io, "fd_buffered_io=%d"},
 631         {Opt_err, NULL}
 632 };
 633
 634 static ssize_t fd_set_configfs_dev_params(struct se_device *dev,
 635                 const char *page, ssize_t count)
 636 {
 637         struct fd_dev *fd_dev = FD_DEV(dev);
 638         char *orig, *ptr, *arg_p, *opts;
 639         substring_t args[MAX_OPT_ARGS];
 640         int ret = 0, arg, token;
 641
 642         opts = kstrdup(page, GFP_KERNEL);
 643         if (!opts)
 644                 return -ENOMEM;
 645
 646         orig = opts;
 647
 648         while ((ptr = strsep(&opts, ",\n")) != NULL) {
 649                 if (!*ptr)
 650                         continue;
 651
 652                 token = match_token(ptr, tokens, args);
 653                 switch (token) {
 654                 case Opt_fd_dev_name:
 655                         if (match_strlcpy(fd_dev->fd_dev_name, &args[0],
 656                                 FD_MAX_DEV_NAME) == 0) {
 657                                 ret = -EINVAL;
 658                                 break;
 659                         }
 660                         pr_debug("FILEIO: Referencing Path: %s\n",
 661                                         fd_dev->fd_dev_name);
 662                         fd_dev->fbd_flags |= FBDF_HAS_PATH;
 663                         break;
 664                 case Opt_fd_dev_size:
 665                         arg_p = match_strdup(&args[0]);
 666                         if (!arg_p) {
 667                                 ret = -ENOMEM;
 668                                 break;
 669                         }
 670                         ret = kstrtoull(arg_p, 0, &fd_dev->fd_dev_size);
 671                         kfree(arg_p);
 672                         if (ret < 0) {
 673                                 pr_err("kstrtoull() failed for"
 674                                                 " fd_dev_size=\n");
 675                                 goto out;
 676                         }
 677                         pr_debug("FILEIO: Referencing Size: %llu"
 678                                         " bytes\n", fd_dev->fd_dev_size);
 679                         fd_dev->fbd_flags |= FBDF_HAS_SIZE;
 680                         break;
 681                 case Opt_fd_buffered_io:
 682                         ret = match_int(args, &arg);
 683                         if (ret)
 684                                 goto out;
 685                         if (arg != 1) {
 686                                 pr_err("bogus fd_buffered_io=%d value\n", arg);
 687                                 ret = -EINVAL;
 688                                 goto out;
 689                         }
 690
 691                         pr_debug("FILEIO: Using buffered I/O"
 692                                 " operations for struct fd_dev\n");
 693
 694                         fd_dev->fbd_flags |= FDBD_HAS_BUFFERED_IO_WCE;
 695                         break;
 696                 default:
 697                         break;
 698                 }
 699         }
 700
 701 out:
 702         kfree(orig);
 703         return (!ret) ? count : ret;
 704 }
 705
 706 static ssize_t fd_show_configfs_dev_params(struct se_device *dev, char *b)
 707 {
 708         struct fd_dev *fd_dev = FD_DEV(dev);
 709         ssize_t bl = 0;
 710
 711         bl = sprintf(b + bl, "TCM FILEIO ID: %u", fd_dev->fd_dev_id);
 712         bl += sprintf(b + bl, "        File: %s  Size: %llu  Mode: %s\n",
 713                 fd_dev->fd_dev_name, fd_dev->fd_dev_size,
 714                 (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) ?
 715                 "Buffered-WCE" : "O_DSYNC");
 716         return bl;
 717 }
 718
 719 static sector_t fd_get_blocks(struct se_device *dev)
 720 {
 721         struct fd_dev *fd_dev = FD_DEV(dev);
 722         struct file *f = fd_dev->fd_file;
 723         struct inode *i = f->f_mapping->host;
 724         unsigned long long dev_size;
 725         /*
 726          * When using a file that references an underlying struct block_device,
 727          * ensure dev_size is always based on the current inode size in order
 728          * to handle underlying block_device resize operations.
 729          */
 730         if (S_ISBLK(i->i_mode))
 731                 dev_size = i_size_read(i);
 732         else
 733                 dev_size = fd_dev->fd_dev_size;
 734
 735         return div_u64(dev_size - dev->dev_attrib.block_size,
 736                        dev->dev_attrib.block_size);
 737 }
 738
 739 static int fd_init_prot(struct se_device *dev)
 740 {
 741         struct fd_dev *fd_dev = FD_DEV(dev);
 742         struct file *prot_file, *file = fd_dev->fd_file;
 743         struct inode *inode;
 744         int ret, flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
 745         char buf[FD_MAX_DEV_PROT_NAME];
 746
 747         if (!file) {
 748                 pr_err("Unable to locate fd_dev->fd_file\n");
 749                 return -ENODEV;
 750         }
 751
 752         inode = file->f_mapping->host;
 753         if (S_ISBLK(inode->i_mode)) {
 754                 pr_err("FILEIO Protection emulation only supported on"
 755                        " !S_ISBLK\n");
 756                 return -ENOSYS;
 757         }
 758
 759         if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE)
 760                 flags &= ~O_DSYNC;
 761
 762         snprintf(buf, FD_MAX_DEV_PROT_NAME, "%s.protection",
 763                  fd_dev->fd_dev_name);
 764
 765         prot_file = filp_open(buf, flags, 0600);
 766         if (IS_ERR(prot_file)) {
 767                 pr_err("filp_open(%s) failed\n", buf);
 768                 ret = PTR_ERR(prot_file);
 769                 return ret;
 770         }
 771         fd_dev->fd_prot_file = prot_file;
 772
 773         return 0;
 774 }
 775
 776 static int fd_format_prot(struct se_device *dev)
 777 {
 778         unsigned char *buf;
 779         int unit_size = FDBD_FORMAT_UNIT_SIZE * dev->dev_attrib.block_size;
 780         int ret;
 781
 782         if (!dev->dev_attrib.pi_prot_type) {
 783                 pr_err("Unable to format_prot while pi_prot_type == 0\n");
 784                 return -ENODEV;
 785         }
 786
 787         buf = vzalloc(unit_size);
 788         if (!buf) {
 789                 pr_err("Unable to allocate FILEIO prot buf\n");
 790                 return -ENOMEM;
 791         }
 792
 793         pr_debug("Using FILEIO prot_length: %llu\n",
 794                  (unsigned long long)(dev->transport->get_blocks(dev) + 1) *
 795                                         dev->prot_length);
 796
 797         memset(buf, 0xff, unit_size);
 798         ret = fd_do_prot_fill(dev, 0, dev->transport->get_blocks(dev) + 1,
 799                               buf, unit_size);
 800         vfree(buf);
 801         return ret;
 802 }
 803
 804 static void fd_free_prot(struct se_device *dev)
 805 {
 806         struct fd_dev *fd_dev = FD_DEV(dev);
 807
 808         if (!fd_dev->fd_prot_file)
 809                 return;
 810
 811         filp_close(fd_dev->fd_prot_file, NULL);
 812         fd_dev->fd_prot_file = NULL;
 813 }
 814
 815 static struct sbc_ops fd_sbc_ops = {
 816         .execute_rw             = fd_execute_rw,
 817         .execute_sync_cache     = fd_execute_sync_cache,
 818         .execute_write_same     = fd_execute_write_same,
 819         .execute_unmap          = fd_execute_unmap,
 820 };
 821
 822 static sense_reason_t
 823 fd_parse_cdb(struct se_cmd *cmd)
 824 {
 825         return sbc_parse_cdb(cmd, &fd_sbc_ops);
 826 }
 827
 828 static const struct target_backend_ops fileio_ops = {
 829         .name                   = "fileio",
 830         .inquiry_prod           = "FILEIO",
 831         .inquiry_rev            = FD_VERSION,
 832         .owner                  = THIS_MODULE,
 833         .attach_hba             = fd_attach_hba,
 834         .detach_hba             = fd_detach_hba,
 835         .alloc_device           = fd_alloc_device,
 836         .configure_device       = fd_configure_device,
 837         .destroy_device         = fd_destroy_device,
 838         .free_device            = fd_free_device,
 839         .parse_cdb              = fd_parse_cdb,
 840         .set_configfs_dev_params = fd_set_configfs_dev_params,
 841         .show_configfs_dev_params = fd_show_configfs_dev_params,
 842         .get_device_type        = sbc_get_device_type,
 843         .get_blocks             = fd_get_blocks,
 844         .init_prot              = fd_init_prot,
 845         .format_prot            = fd_format_prot,
 846         .free_prot              = fd_free_prot,
 847         .tb_dev_attrib_attrs    = sbc_attrib_attrs,
 848 };
 849
 850 static int __init fileio_module_init(void)
 851 {
 852         return transport_backend_register(&fileio_ops);
 853 }
 854
 855 static void __exit fileio_module_exit(void)
 856 {
 857         target_backend_unregister(&fileio_ops);
 858 }
 859
 860 MODULE_DESCRIPTION("TCM FILEIO subsystem plugin");
 861 MODULE_AUTHOR("nab@Linux-iSCSI.org");
 862 MODULE_LICENSE("GPL");
 863
 864 module_init(fileio_module_init);
 865 module_exit(fileio_module_exit);