drivers/target/target_core_file.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*******************************************************************************
   3  * Filename:  target_core_file.c
   4  *
   5  * This file contains the Storage Engine <-> FILEIO transport specific functions
   6  *
   7  * (c) Copyright 2005-2013 Datera, Inc.
   8  *
   9  * Nicholas A. Bellinger <nab@kernel.org>
  10  *
  11  ******************************************************************************/
  12
  13 #include <linux/string.h>
  14 #include <linux/parser.h>
  15 #include <linux/timer.h>
  16 #include <linux/blkdev.h>
  17 #include <linux/slab.h>
  18 #include <linux/spinlock.h>
  19 #include <linux/module.h>
  20 #include <linux/vmalloc.h>
  21 #include <linux/falloc.h>
  22 #include <linux/uio.h>
  23 #include <linux/scatterlist.h>
  24 #include <scsi/scsi_proto.h>
  25 #include <asm/unaligned.h>
  26
  27 #include <target/target_core_base.h>
  28 #include <target/target_core_backend.h>
  29
  30 #include "target_core_file.h"
  31
  32 static inline struct fd_dev *FD_DEV(struct se_device *dev)
  33 {
  34         return container_of(dev, struct fd_dev, dev);
  35 }
  36
  37 static int fd_attach_hba(struct se_hba *hba, u32 host_id)
  38 {
  39         struct fd_host *fd_host;
  40
  41         fd_host = kzalloc(sizeof(struct fd_host), GFP_KERNEL);
  42         if (!fd_host) {
  43                 pr_err("Unable to allocate memory for struct fd_host\n");
  44                 return -ENOMEM;
  45         }
  46
  47         fd_host->fd_host_id = host_id;
  48
  49         hba->hba_ptr = fd_host;
  50
  51         pr_debug("CORE_HBA[%d] - TCM FILEIO HBA Driver %s on Generic"
  52                 " Target Core Stack %s\n", hba->hba_id, FD_VERSION,
  53                 TARGET_CORE_VERSION);
  54         pr_debug("CORE_HBA[%d] - Attached FILEIO HBA: %u to Generic\n",
  55                 hba->hba_id, fd_host->fd_host_id);
  56
  57         return 0;
  58 }
  59
  60 static void fd_detach_hba(struct se_hba *hba)
  61 {
  62         struct fd_host *fd_host = hba->hba_ptr;
  63
  64         pr_debug("CORE_HBA[%d] - Detached FILEIO HBA: %u from Generic"
  65                 " Target Core\n", hba->hba_id, fd_host->fd_host_id);
  66
  67         kfree(fd_host);
  68         hba->hba_ptr = NULL;
  69 }
  70
  71 static struct se_device *fd_alloc_device(struct se_hba *hba, const char *name)
  72 {
  73         struct fd_dev *fd_dev;
  74         struct fd_host *fd_host = hba->hba_ptr;
  75
  76         fd_dev = kzalloc(sizeof(struct fd_dev), GFP_KERNEL);
  77         if (!fd_dev) {
  78                 pr_err("Unable to allocate memory for struct fd_dev\n");
  79                 return NULL;
  80         }
  81
  82         fd_dev->fd_host = fd_host;
  83
  84         pr_debug("FILEIO: Allocated fd_dev for %p\n", name);
  85
  86         return &fd_dev->dev;
  87 }
  88
  89 static bool fd_configure_unmap(struct se_device *dev)
  90 {
  91         struct file *file = FD_DEV(dev)->fd_file;
  92         struct inode *inode = file->f_mapping->host;
  93
  94         if (S_ISBLK(inode->i_mode))
  95                 return target_configure_unmap_from_queue(&dev->dev_attrib,
  96                                                          I_BDEV(inode));
  97
  98         /* Limit UNMAP emulation to 8k Number of LBAs (NoLB) */
  99         dev->dev_attrib.max_unmap_lba_count = 0x2000;
 100         /* Currently hardcoded to 1 in Linux/SCSI code. */
 101         dev->dev_attrib.max_unmap_block_desc_count = 1;
 102         dev->dev_attrib.unmap_granularity = 1;
 103         dev->dev_attrib.unmap_granularity_alignment = 0;
 104         return true;
 105 }
 106
 107 static int fd_configure_device(struct se_device *dev)
 108 {
 109         struct fd_dev *fd_dev = FD_DEV(dev);
 110         struct fd_host *fd_host = dev->se_hba->hba_ptr;
 111         struct file *file;
 112         struct inode *inode = NULL;
 113         int flags, ret = -EINVAL;
 114
 115         if (!(fd_dev->fbd_flags & FBDF_HAS_PATH)) {
 116                 pr_err("Missing fd_dev_name=\n");
 117                 return -EINVAL;
 118         }
 119
 120         /*
 121          * Use O_DSYNC by default instead of O_SYNC to forgo syncing
 122          * of pure timestamp updates.
 123          */
 124         flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
 125
 126         /*
 127          * Optionally allow fd_buffered_io=1 to be enabled for people
 128          * who want use the fs buffer cache as an WriteCache mechanism.
 129          *
 130          * This means that in event of a hard failure, there is a risk
 131          * of silent data-loss if the SCSI client has *not* performed a
 132          * forced unit access (FUA) write, or issued SYNCHRONIZE_CACHE
 133          * to write-out the entire device cache.
 134          */
 135         if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
 136                 pr_debug("FILEIO: Disabling O_DSYNC, using buffered FILEIO\n");
 137                 flags &= ~O_DSYNC;
 138         }
 139
 140         file = filp_open(fd_dev->fd_dev_name, flags, 0600);
 141         if (IS_ERR(file)) {
 142                 pr_err("filp_open(%s) failed\n", fd_dev->fd_dev_name);
 143                 ret = PTR_ERR(file);
 144                 goto fail;
 145         }
 146         fd_dev->fd_file = file;
 147         /*
 148          * If using a block backend with this struct file, we extract
 149          * fd_dev->fd_[block,dev]_size from struct block_device.
 150          *
 151          * Otherwise, we use the passed fd_size= from configfs
 152          */
 153         inode = file->f_mapping->host;
 154         if (S_ISBLK(inode->i_mode)) {
 155                 struct block_device *bdev = I_BDEV(inode);
 156                 unsigned long long dev_size;
 157
 158                 fd_dev->fd_block_size = bdev_logical_block_size(bdev);
 159                 /*
 160                  * Determine the number of bytes from i_size_read() minus
 161                  * one (1) logical sector from underlying struct block_device
 162                  */
 163                 dev_size = (i_size_read(file->f_mapping->host) -
 164                                        fd_dev->fd_block_size);
 165
 166                 pr_debug("FILEIO: Using size: %llu bytes from struct"
 167                         " block_device blocks: %llu logical_block_size: %d\n",
 168                         dev_size, div_u64(dev_size, fd_dev->fd_block_size),
 169                         fd_dev->fd_block_size);
 170                 /*
 171                  * Enable write same emulation for IBLOCK and use 0xFFFF as
 172                  * the smaller WRITE_SAME(10) only has a two-byte block count.
 173                  */
 174                 dev->dev_attrib.max_write_same_len = 0xFFFF;
 175
 176                 if (bdev_nonrot(bdev))
 177                         dev->dev_attrib.is_nonrot = 1;
 178         } else {
 179                 if (!(fd_dev->fbd_flags & FBDF_HAS_SIZE)) {
 180                         pr_err("FILEIO: Missing fd_dev_size="
 181                                 " parameter, and no backing struct"
 182                                 " block_device\n");
 183                         goto fail;
 184                 }
 185
 186                 fd_dev->fd_block_size = FD_BLOCKSIZE;
 187
 188                 /*
 189                  * Limit WRITE_SAME w/ UNMAP=0 emulation to 8k Number of LBAs (NoLB)
 190                  * based upon struct iovec limit for vfs_writev()
 191                  */
 192                 dev->dev_attrib.max_write_same_len = 0x1000;
 193         }
 194
 195         dev->dev_attrib.hw_block_size = fd_dev->fd_block_size;
 196         dev->dev_attrib.hw_max_sectors = FD_MAX_BYTES / fd_dev->fd_block_size;
 197         dev->dev_attrib.hw_queue_depth = FD_MAX_DEVICE_QUEUE_DEPTH;
 198
 199         if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
 200                 pr_debug("FILEIO: Forcing setting of emulate_write_cache=1"
 201                         " with FDBD_HAS_BUFFERED_IO_WCE\n");
 202                 dev->dev_attrib.emulate_write_cache = 1;
 203         }
 204
 205         fd_dev->fd_dev_id = fd_host->fd_host_dev_id_count++;
 206         fd_dev->fd_queue_depth = dev->queue_depth;
 207
 208         pr_debug("CORE_FILE[%u] - Added TCM FILEIO Device ID: %u at %s,"
 209                 " %llu total bytes\n", fd_host->fd_host_id, fd_dev->fd_dev_id,
 210                         fd_dev->fd_dev_name, fd_dev->fd_dev_size);
 211
 212         return 0;
 213 fail:
 214         if (fd_dev->fd_file) {
 215                 filp_close(fd_dev->fd_file, NULL);
 216                 fd_dev->fd_file = NULL;
 217         }
 218         return ret;
 219 }
 220
 221 static void fd_dev_call_rcu(struct rcu_head *p)
 222 {
 223         struct se_device *dev = container_of(p, struct se_device, rcu_head);
 224         struct fd_dev *fd_dev = FD_DEV(dev);
 225
 226         kfree(fd_dev);
 227 }
 228
 229 static void fd_free_device(struct se_device *dev)
 230 {
 231         call_rcu(&dev->rcu_head, fd_dev_call_rcu);
 232 }
 233
 234 static void fd_destroy_device(struct se_device *dev)
 235 {
 236         struct fd_dev *fd_dev = FD_DEV(dev);
 237
 238         if (fd_dev->fd_file) {
 239                 filp_close(fd_dev->fd_file, NULL);
 240                 fd_dev->fd_file = NULL;
 241         }
 242 }
 243
 244 struct target_core_file_cmd {
 245         unsigned long   len;
 246         struct se_cmd   *cmd;
 247         struct kiocb    iocb;
 248         struct bio_vec  bvecs[];
 249 };
 250
 251 static void cmd_rw_aio_complete(struct kiocb *iocb, long ret)
 252 {
 253         struct target_core_file_cmd *cmd;
 254
 255         cmd = container_of(iocb, struct target_core_file_cmd, iocb);
 256
 257         if (ret != cmd->len)
 258                 target_complete_cmd(cmd->cmd, SAM_STAT_CHECK_CONDITION);
 259         else
 260                 target_complete_cmd(cmd->cmd, SAM_STAT_GOOD);
 261
 262         kfree(cmd);
 263 }
 264
 265 static sense_reason_t
 266 fd_execute_rw_aio(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 267               enum dma_data_direction data_direction)
 268 {
 269         int is_write = !(data_direction == DMA_FROM_DEVICE);
 270         struct se_device *dev = cmd->se_dev;
 271         struct fd_dev *fd_dev = FD_DEV(dev);
 272         struct file *file = fd_dev->fd_file;
 273         struct target_core_file_cmd *aio_cmd;
 274         struct iov_iter iter;
 275         struct scatterlist *sg;
 276         ssize_t len = 0;
 277         int ret = 0, i;
 278
 279         aio_cmd = kmalloc(struct_size(aio_cmd, bvecs, sgl_nents), GFP_KERNEL);
 280         if (!aio_cmd)
 281                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 282
 283         for_each_sg(sgl, sg, sgl_nents, i) {
 284                 bvec_set_page(&aio_cmd->bvecs[i], sg_page(sg), sg->length,
 285                               sg->offset);
 286                 len += sg->length;
 287         }
 288
 289         iov_iter_bvec(&iter, is_write, aio_cmd->bvecs, sgl_nents, len);
 290
 291         aio_cmd->cmd = cmd;
 292         aio_cmd->len = len;
 293         aio_cmd->iocb.ki_pos = cmd->t_task_lba * dev->dev_attrib.block_size;
 294         aio_cmd->iocb.ki_filp = file;
 295         aio_cmd->iocb.ki_complete = cmd_rw_aio_complete;
 296         aio_cmd->iocb.ki_flags = IOCB_DIRECT;
 297
 298         if (is_write && (cmd->se_cmd_flags & SCF_FUA))
 299                 aio_cmd->iocb.ki_flags |= IOCB_DSYNC;
 300
 301         if (is_write)
 302                 ret = call_write_iter(file, &aio_cmd->iocb, &iter);
 303         else
 304                 ret = call_read_iter(file, &aio_cmd->iocb, &iter);
 305
 306         if (ret != -EIOCBQUEUED)
 307                 cmd_rw_aio_complete(&aio_cmd->iocb, ret);
 308
 309         return 0;
 310 }
 311
 312 static int fd_do_rw(struct se_cmd *cmd, struct file *fd,
 313                     u32 block_size, struct scatterlist *sgl,
 314                     u32 sgl_nents, u32 data_length, int is_write)
 315 {
 316         struct scatterlist *sg;
 317         struct iov_iter iter;
 318         struct bio_vec *bvec;
 319         ssize_t len = 0;
 320         loff_t pos = (cmd->t_task_lba * block_size);
 321         int ret = 0, i;
 322
 323         bvec = kcalloc(sgl_nents, sizeof(struct bio_vec), GFP_KERNEL);
 324         if (!bvec) {
 325                 pr_err("Unable to allocate fd_do_readv iov[]\n");
 326                 return -ENOMEM;
 327         }
 328
 329         for_each_sg(sgl, sg, sgl_nents, i) {
 330                 bvec_set_page(&bvec[i], sg_page(sg), sg->length, sg->offset);
 331                 len += sg->length;
 332         }
 333
 334         iov_iter_bvec(&iter, is_write, bvec, sgl_nents, len);
 335         if (is_write)
 336                 ret = vfs_iter_write(fd, &iter, &pos, 0);
 337         else
 338                 ret = vfs_iter_read(fd, &iter, &pos, 0);
 339
 340         if (is_write) {
 341                 if (ret < 0 || ret != data_length) {
 342                         pr_err("%s() write returned %d\n", __func__, ret);
 343                         if (ret >= 0)
 344                                 ret = -EINVAL;
 345                 }
 346         } else {
 347                 /*
 348                  * Return zeros and GOOD status even if the READ did not return
 349                  * the expected virt_size for struct file w/o a backing struct
 350                  * block_device.
 351                  */
 352                 if (S_ISBLK(file_inode(fd)->i_mode)) {
 353                         if (ret < 0 || ret != data_length) {
 354                                 pr_err("%s() returned %d, expecting %u for "
 355                                                 "S_ISBLK\n", __func__, ret,
 356                                                 data_length);
 357                                 if (ret >= 0)
 358                                         ret = -EINVAL;
 359                         }
 360                 } else {
 361                         if (ret < 0) {
 362                                 pr_err("%s() returned %d for non S_ISBLK\n",
 363                                                 __func__, ret);
 364                         } else if (ret != data_length) {
 365                                 /*
 366                                  * Short read case:
 367                                  * Probably some one truncate file under us.
 368                                  * We must explicitly zero sg-pages to prevent
 369                                  * expose uninizialized pages to userspace.
 370                                  */
 371                                 if (ret < data_length)
 372                                         ret += iov_iter_zero(data_length - ret, &iter);
 373                                 else
 374                                         ret = -EINVAL;
 375                         }
 376                 }
 377         }
 378         kfree(bvec);
 379         return ret;
 380 }
 381
 382 static sense_reason_t
 383 fd_execute_sync_cache(struct se_cmd *cmd)
 384 {
 385         struct se_device *dev = cmd->se_dev;
 386         struct fd_dev *fd_dev = FD_DEV(dev);
 387         int immed = (cmd->t_task_cdb[1] & 0x2);
 388         loff_t start, end;
 389         int ret;
 390
 391         /*
 392          * If the Immediate bit is set, queue up the GOOD response
 393          * for this SYNCHRONIZE_CACHE op
 394          */
 395         if (immed)
 396                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 397
 398         /*
 399          * Determine if we will be flushing the entire device.
 400          */
 401         if (cmd->t_task_lba == 0 && cmd->data_length == 0) {
 402                 start = 0;
 403                 end = LLONG_MAX;
 404         } else {
 405                 start = cmd->t_task_lba * dev->dev_attrib.block_size;
 406                 if (cmd->data_length)
 407                         end = start + cmd->data_length - 1;
 408                 else
 409                         end = LLONG_MAX;
 410         }
 411
 412         ret = vfs_fsync_range(fd_dev->fd_file, start, end, 1);
 413         if (ret != 0)
 414                 pr_err("FILEIO: vfs_fsync_range() failed: %d\n", ret);
 415
 416         if (immed)
 417                 return 0;
 418
 419         if (ret)
 420                 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
 421         else
 422                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 423
 424         return 0;
 425 }
 426
 427 static sense_reason_t
 428 fd_execute_write_same(struct se_cmd *cmd)
 429 {
 430         struct se_device *se_dev = cmd->se_dev;
 431         struct fd_dev *fd_dev = FD_DEV(se_dev);
 432         loff_t pos = cmd->t_task_lba * se_dev->dev_attrib.block_size;
 433         sector_t nolb = sbc_get_write_same_sectors(cmd);
 434         struct iov_iter iter;
 435         struct bio_vec *bvec;
 436         unsigned int len = 0, i;
 437         ssize_t ret;
 438
 439         if (cmd->prot_op) {
 440                 pr_err("WRITE_SAME: Protection information with FILEIO"
 441                        " backends not supported\n");
 442                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 443         }
 444
 445         if (!cmd->t_data_nents)
 446                 return TCM_INVALID_CDB_FIELD;
 447
 448         if (cmd->t_data_nents > 1 ||
 449             cmd->t_data_sg[0].length != cmd->se_dev->dev_attrib.block_size) {
 450                 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
 451                         " block_size: %u\n",
 452                         cmd->t_data_nents,
 453                         cmd->t_data_sg[0].length,
 454                         cmd->se_dev->dev_attrib.block_size);
 455                 return TCM_INVALID_CDB_FIELD;
 456         }
 457
 458         bvec = kcalloc(nolb, sizeof(struct bio_vec), GFP_KERNEL);
 459         if (!bvec)
 460                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 461
 462         for (i = 0; i < nolb; i++) {
 463                 bvec_set_page(&bvec[i], sg_page(&cmd->t_data_sg[0]),
 464                               cmd->t_data_sg[0].length,
 465                               cmd->t_data_sg[0].offset);
 466                 len += se_dev->dev_attrib.block_size;
 467         }
 468
 469         iov_iter_bvec(&iter, ITER_SOURCE, bvec, nolb, len);
 470         ret = vfs_iter_write(fd_dev->fd_file, &iter, &pos, 0);
 471
 472         kfree(bvec);
 473         if (ret < 0 || ret != len) {
 474                 pr_err("vfs_iter_write() returned %zd for write same\n", ret);
 475                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 476         }
 477
 478         target_complete_cmd(cmd, SAM_STAT_GOOD);
 479         return 0;
 480 }
 481
 482 static int
 483 fd_do_prot_fill(struct se_device *se_dev, sector_t lba, sector_t nolb,
 484                 void *buf, size_t bufsize)
 485 {
 486         struct fd_dev *fd_dev = FD_DEV(se_dev);
 487         struct file *prot_fd = fd_dev->fd_prot_file;
 488         sector_t prot_length, prot;
 489         loff_t pos = lba * se_dev->prot_length;
 490
 491         if (!prot_fd) {
 492                 pr_err("Unable to locate fd_dev->fd_prot_file\n");
 493                 return -ENODEV;
 494         }
 495
 496         prot_length = nolb * se_dev->prot_length;
 497
 498         memset(buf, 0xff, bufsize);
 499         for (prot = 0; prot < prot_length;) {
 500                 sector_t len = min_t(sector_t, bufsize, prot_length - prot);
 501                 ssize_t ret = kernel_write(prot_fd, buf, len, &pos);
 502
 503                 if (ret != len) {
 504                         pr_err("vfs_write to prot file failed: %zd\n", ret);
 505                         return ret < 0 ? ret : -ENODEV;
 506                 }
 507                 prot += ret;
 508         }
 509
 510         return 0;
 511 }
 512
 513 static int
 514 fd_do_prot_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
 515 {
 516         void *buf;
 517         int rc;
 518
 519         buf = (void *)__get_free_page(GFP_KERNEL);
 520         if (!buf) {
 521                 pr_err("Unable to allocate FILEIO prot buf\n");
 522                 return -ENOMEM;
 523         }
 524
 525         rc = fd_do_prot_fill(cmd->se_dev, lba, nolb, buf, PAGE_SIZE);
 526
 527         free_page((unsigned long)buf);
 528
 529         return rc;
 530 }
 531
 532 static sense_reason_t
 533 fd_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
 534 {
 535         struct file *file = FD_DEV(cmd->se_dev)->fd_file;
 536         struct inode *inode = file->f_mapping->host;
 537         int ret;
 538
 539         if (!nolb) {
 540                 return 0;
 541         }
 542
 543         if (cmd->se_dev->dev_attrib.pi_prot_type) {
 544                 ret = fd_do_prot_unmap(cmd, lba, nolb);
 545                 if (ret)
 546                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 547         }
 548
 549         if (S_ISBLK(inode->i_mode)) {
 550                 /* The backend is block device, use discard */
 551                 struct block_device *bdev = I_BDEV(inode);
 552                 struct se_device *dev = cmd->se_dev;
 553
 554                 ret = blkdev_issue_discard(bdev,
 555                                            target_to_linux_sector(dev, lba),
 556                                            target_to_linux_sector(dev,  nolb),
 557                                            GFP_KERNEL);
 558                 if (ret < 0) {
 559                         pr_warn("FILEIO: blkdev_issue_discard() failed: %d\n",
 560                                 ret);
 561                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 562                 }
 563         } else {
 564                 /* The backend is normal file, use fallocate */
 565                 struct se_device *se_dev = cmd->se_dev;
 566                 loff_t pos = lba * se_dev->dev_attrib.block_size;
 567                 unsigned int len = nolb * se_dev->dev_attrib.block_size;
 568                 int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
 569
 570                 if (!file->f_op->fallocate)
 571                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 572
 573                 ret = file->f_op->fallocate(file, mode, pos, len);
 574                 if (ret < 0) {
 575                         pr_warn("FILEIO: fallocate() failed: %d\n", ret);
 576                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 577                 }
 578         }
 579
 580         return 0;
 581 }
 582
 583 static sense_reason_t
 584 fd_execute_rw_buffered(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 585               enum dma_data_direction data_direction)
 586 {
 587         struct se_device *dev = cmd->se_dev;
 588         struct fd_dev *fd_dev = FD_DEV(dev);
 589         struct file *file = fd_dev->fd_file;
 590         struct file *pfile = fd_dev->fd_prot_file;
 591         sense_reason_t rc;
 592         int ret = 0;
 593         /*
 594          * Call vectorized fileio functions to map struct scatterlist
 595          * physical memory addresses to struct iovec virtual memory.
 596          */
 597         if (data_direction == DMA_FROM_DEVICE) {
 598                 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 599                         ret = fd_do_rw(cmd, pfile, dev->prot_length,
 600                                        cmd->t_prot_sg, cmd->t_prot_nents,
 601                                        cmd->prot_length, 0);
 602                         if (ret < 0)
 603                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 604                 }
 605
 606                 ret = fd_do_rw(cmd, file, dev->dev_attrib.block_size,
 607                                sgl, sgl_nents, cmd->data_length, 0);
 608
 609                 if (ret > 0 && cmd->prot_type && dev->dev_attrib.pi_prot_type &&
 610                     dev->dev_attrib.pi_prot_verify) {
 611                         u32 sectors = cmd->data_length >>
 612                                         ilog2(dev->dev_attrib.block_size);
 613
 614                         rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors,
 615                                             0, cmd->t_prot_sg, 0);
 616                         if (rc)
 617                                 return rc;
 618                 }
 619         } else {
 620                 if (cmd->prot_type && dev->dev_attrib.pi_prot_type &&
 621                     dev->dev_attrib.pi_prot_verify) {
 622                         u32 sectors = cmd->data_length >>
 623                                         ilog2(dev->dev_attrib.block_size);
 624
 625                         rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors,
 626                                             0, cmd->t_prot_sg, 0);
 627                         if (rc)
 628                                 return rc;
 629                 }
 630
 631                 ret = fd_do_rw(cmd, file, dev->dev_attrib.block_size,
 632                                sgl, sgl_nents, cmd->data_length, 1);
 633                 /*
 634                  * Perform implicit vfs_fsync_range() for fd_do_writev() ops
 635                  * for SCSI WRITEs with Forced Unit Access (FUA) set.
 636                  * Allow this to happen independent of WCE=0 setting.
 637                  */
 638                 if (ret > 0 && (cmd->se_cmd_flags & SCF_FUA)) {
 639                         loff_t start = cmd->t_task_lba *
 640                                 dev->dev_attrib.block_size;
 641                         loff_t end;
 642
 643                         if (cmd->data_length)
 644                                 end = start + cmd->data_length - 1;
 645                         else
 646                                 end = LLONG_MAX;
 647
 648                         vfs_fsync_range(fd_dev->fd_file, start, end, 1);
 649                 }
 650
 651                 if (ret > 0 && cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 652                         ret = fd_do_rw(cmd, pfile, dev->prot_length,
 653                                        cmd->t_prot_sg, cmd->t_prot_nents,
 654                                        cmd->prot_length, 1);
 655                         if (ret < 0)
 656                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 657                 }
 658         }
 659
 660         if (ret < 0)
 661                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 662
 663         target_complete_cmd(cmd, SAM_STAT_GOOD);
 664         return 0;
 665 }
 666
 667 static sense_reason_t
 668 fd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 669               enum dma_data_direction data_direction)
 670 {
 671         struct se_device *dev = cmd->se_dev;
 672         struct fd_dev *fd_dev = FD_DEV(dev);
 673
 674         /*
 675          * We are currently limited by the number of iovecs (2048) per
 676          * single vfs_[writev,readv] call.
 677          */
 678         if (cmd->data_length > FD_MAX_BYTES) {
 679                 pr_err("FILEIO: Not able to process I/O of %u bytes due to"
 680                        "FD_MAX_BYTES: %u iovec count limitation\n",
 681                         cmd->data_length, FD_MAX_BYTES);
 682                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 683         }
 684
 685         if (fd_dev->fbd_flags & FDBD_HAS_ASYNC_IO)
 686                 return fd_execute_rw_aio(cmd, sgl, sgl_nents, data_direction);
 687         return fd_execute_rw_buffered(cmd, sgl, sgl_nents, data_direction);
 688 }
 689
 690 enum {
 691         Opt_fd_dev_name, Opt_fd_dev_size, Opt_fd_buffered_io,
 692         Opt_fd_async_io, Opt_err
 693 };
 694
 695 static match_table_t tokens = {
 696         {Opt_fd_dev_name, "fd_dev_name=%s"},
 697         {Opt_fd_dev_size, "fd_dev_size=%s"},
 698         {Opt_fd_buffered_io, "fd_buffered_io=%d"},
 699         {Opt_fd_async_io, "fd_async_io=%d"},
 700         {Opt_err, NULL}
 701 };
 702
 703 static ssize_t fd_set_configfs_dev_params(struct se_device *dev,
 704                 const char *page, ssize_t count)
 705 {
 706         struct fd_dev *fd_dev = FD_DEV(dev);
 707         char *orig, *ptr, *arg_p, *opts;
 708         substring_t args[MAX_OPT_ARGS];
 709         int ret = 0, arg, token;
 710
 711         opts = kstrdup(page, GFP_KERNEL);
 712         if (!opts)
 713                 return -ENOMEM;
 714
 715         orig = opts;
 716
 717         while ((ptr = strsep(&opts, ",\n")) != NULL) {
 718                 if (!*ptr)
 719                         continue;
 720
 721                 token = match_token(ptr, tokens, args);
 722                 switch (token) {
 723                 case Opt_fd_dev_name:
 724                         if (match_strlcpy(fd_dev->fd_dev_name, &args[0],
 725                                 FD_MAX_DEV_NAME) == 0) {
 726                                 ret = -EINVAL;
 727                                 break;
 728                         }
 729                         pr_debug("FILEIO: Referencing Path: %s\n",
 730                                         fd_dev->fd_dev_name);
 731                         fd_dev->fbd_flags |= FBDF_HAS_PATH;
 732                         break;
 733                 case Opt_fd_dev_size:
 734                         arg_p = match_strdup(&args[0]);
 735                         if (!arg_p) {
 736                                 ret = -ENOMEM;
 737                                 break;
 738                         }
 739                         ret = kstrtoull(arg_p, 0, &fd_dev->fd_dev_size);
 740                         kfree(arg_p);
 741                         if (ret < 0) {
 742                                 pr_err("kstrtoull() failed for"
 743                                                 " fd_dev_size=\n");
 744                                 goto out;
 745                         }
 746                         pr_debug("FILEIO: Referencing Size: %llu"
 747                                         " bytes\n", fd_dev->fd_dev_size);
 748                         fd_dev->fbd_flags |= FBDF_HAS_SIZE;
 749                         break;
 750                 case Opt_fd_buffered_io:
 751                         ret = match_int(args, &arg);
 752                         if (ret)
 753                                 goto out;
 754                         if (arg != 1) {
 755                                 pr_err("bogus fd_buffered_io=%d value\n", arg);
 756                                 ret = -EINVAL;
 757                                 goto out;
 758                         }
 759
 760                         pr_debug("FILEIO: Using buffered I/O"
 761                                 " operations for struct fd_dev\n");
 762
 763                         fd_dev->fbd_flags |= FDBD_HAS_BUFFERED_IO_WCE;
 764                         break;
 765                 case Opt_fd_async_io:
 766                         ret = match_int(args, &arg);
 767                         if (ret)
 768                                 goto out;
 769                         if (arg != 1) {
 770                                 pr_err("bogus fd_async_io=%d value\n", arg);
 771                                 ret = -EINVAL;
 772                                 goto out;
 773                         }
 774
 775                         pr_debug("FILEIO: Using async I/O"
 776                                 " operations for struct fd_dev\n");
 777
 778                         fd_dev->fbd_flags |= FDBD_HAS_ASYNC_IO;
 779                         break;
 780                 default:
 781                         break;
 782                 }
 783         }
 784
 785 out:
 786         kfree(orig);
 787         return (!ret) ? count : ret;
 788 }
 789
 790 static ssize_t fd_show_configfs_dev_params(struct se_device *dev, char *b)
 791 {
 792         struct fd_dev *fd_dev = FD_DEV(dev);
 793         ssize_t bl = 0;
 794
 795         bl = sprintf(b + bl, "TCM FILEIO ID: %u", fd_dev->fd_dev_id);
 796         bl += sprintf(b + bl, "        File: %s  Size: %llu  Mode: %s Async: %d\n",
 797                 fd_dev->fd_dev_name, fd_dev->fd_dev_size,
 798                 (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) ?
 799                 "Buffered-WCE" : "O_DSYNC",
 800                 !!(fd_dev->fbd_flags & FDBD_HAS_ASYNC_IO));
 801         return bl;
 802 }
 803
 804 static sector_t fd_get_blocks(struct se_device *dev)
 805 {
 806         struct fd_dev *fd_dev = FD_DEV(dev);
 807         struct file *f = fd_dev->fd_file;
 808         struct inode *i = f->f_mapping->host;
 809         unsigned long long dev_size;
 810         /*
 811          * When using a file that references an underlying struct block_device,
 812          * ensure dev_size is always based on the current inode size in order
 813          * to handle underlying block_device resize operations.
 814          */
 815         if (S_ISBLK(i->i_mode))
 816                 dev_size = i_size_read(i);
 817         else
 818                 dev_size = fd_dev->fd_dev_size;
 819
 820         return div_u64(dev_size - dev->dev_attrib.block_size,
 821                        dev->dev_attrib.block_size);
 822 }
 823
 824 static int fd_init_prot(struct se_device *dev)
 825 {
 826         struct fd_dev *fd_dev = FD_DEV(dev);
 827         struct file *prot_file, *file = fd_dev->fd_file;
 828         struct inode *inode;
 829         int ret, flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
 830         char buf[FD_MAX_DEV_PROT_NAME];
 831
 832         if (!file) {
 833                 pr_err("Unable to locate fd_dev->fd_file\n");
 834                 return -ENODEV;
 835         }
 836
 837         inode = file->f_mapping->host;
 838         if (S_ISBLK(inode->i_mode)) {
 839                 pr_err("FILEIO Protection emulation only supported on"
 840                        " !S_ISBLK\n");
 841                 return -ENOSYS;
 842         }
 843
 844         if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE)
 845                 flags &= ~O_DSYNC;
 846
 847         snprintf(buf, FD_MAX_DEV_PROT_NAME, "%s.protection",
 848                  fd_dev->fd_dev_name);
 849
 850         prot_file = filp_open(buf, flags, 0600);
 851         if (IS_ERR(prot_file)) {
 852                 pr_err("filp_open(%s) failed\n", buf);
 853                 ret = PTR_ERR(prot_file);
 854                 return ret;
 855         }
 856         fd_dev->fd_prot_file = prot_file;
 857
 858         return 0;
 859 }
 860
 861 static int fd_format_prot(struct se_device *dev)
 862 {
 863         unsigned char *buf;
 864         int unit_size = FDBD_FORMAT_UNIT_SIZE * dev->dev_attrib.block_size;
 865         int ret;
 866
 867         if (!dev->dev_attrib.pi_prot_type) {
 868                 pr_err("Unable to format_prot while pi_prot_type == 0\n");
 869                 return -ENODEV;
 870         }
 871
 872         buf = vzalloc(unit_size);
 873         if (!buf) {
 874                 pr_err("Unable to allocate FILEIO prot buf\n");
 875                 return -ENOMEM;
 876         }
 877
 878         pr_debug("Using FILEIO prot_length: %llu\n",
 879                  (unsigned long long)(dev->transport->get_blocks(dev) + 1) *
 880                                         dev->prot_length);
 881
 882         ret = fd_do_prot_fill(dev, 0, dev->transport->get_blocks(dev) + 1,
 883                               buf, unit_size);
 884         vfree(buf);
 885         return ret;
 886 }
 887
 888 static void fd_free_prot(struct se_device *dev)
 889 {
 890         struct fd_dev *fd_dev = FD_DEV(dev);
 891
 892         if (!fd_dev->fd_prot_file)
 893                 return;
 894
 895         filp_close(fd_dev->fd_prot_file, NULL);
 896         fd_dev->fd_prot_file = NULL;
 897 }
 898
 899 static struct exec_cmd_ops fd_exec_cmd_ops = {
 900         .execute_rw             = fd_execute_rw,
 901         .execute_sync_cache     = fd_execute_sync_cache,
 902         .execute_write_same     = fd_execute_write_same,
 903         .execute_unmap          = fd_execute_unmap,
 904 };
 905
 906 static sense_reason_t
 907 fd_parse_cdb(struct se_cmd *cmd)
 908 {
 909         return sbc_parse_cdb(cmd, &fd_exec_cmd_ops);
 910 }
 911
 912 static const struct target_backend_ops fileio_ops = {
 913         .name                   = "fileio",
 914         .inquiry_prod           = "FILEIO",
 915         .inquiry_rev            = FD_VERSION,
 916         .owner                  = THIS_MODULE,
 917         .attach_hba             = fd_attach_hba,
 918         .detach_hba             = fd_detach_hba,
 919         .alloc_device           = fd_alloc_device,
 920         .configure_device       = fd_configure_device,
 921         .destroy_device         = fd_destroy_device,
 922         .free_device            = fd_free_device,
 923         .configure_unmap        = fd_configure_unmap,
 924         .parse_cdb              = fd_parse_cdb,
 925         .set_configfs_dev_params = fd_set_configfs_dev_params,
 926         .show_configfs_dev_params = fd_show_configfs_dev_params,
 927         .get_device_type        = sbc_get_device_type,
 928         .get_blocks             = fd_get_blocks,
 929         .init_prot              = fd_init_prot,
 930         .format_prot            = fd_format_prot,
 931         .free_prot              = fd_free_prot,
 932         .tb_dev_attrib_attrs    = sbc_attrib_attrs,
 933 };
 934
 935 static int __init fileio_module_init(void)
 936 {
 937         return transport_backend_register(&fileio_ops);
 938 }
 939
 940 static void __exit fileio_module_exit(void)
 941 {
 942         target_backend_unregister(&fileio_ops);
 943 }
 944
 945 MODULE_DESCRIPTION("TCM FILEIO subsystem plugin");
 946 MODULE_AUTHOR("nab@Linux-iSCSI.org");
 947 MODULE_LICENSE("GPL");
 948
 949 module_init(fileio_module_init);
 950 module_exit(fileio_module_exit);