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 <[email protected]>
  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 int fd_configure_device(struct se_device *dev)
  90 {
  91         struct fd_dev *fd_dev = FD_DEV(dev);
  92         struct fd_host *fd_host = dev->se_hba->hba_ptr;
  93         struct file *file;
  94         struct inode *inode = NULL;
  95         int flags, ret = -EINVAL;
  96
  97         if (!(fd_dev->fbd_flags & FBDF_HAS_PATH)) {
  98                 pr_err("Missing fd_dev_name=\n");
  99                 return -EINVAL;
 100         }
 101
 102         /*
 103          * Use O_DSYNC by default instead of O_SYNC to forgo syncing
 104          * of pure timestamp updates.
 105          */
 106         flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
 107
 108         /*
 109          * Optionally allow fd_buffered_io=1 to be enabled for people
 110          * who want use the fs buffer cache as an WriteCache mechanism.
 111          *
 112          * This means that in event of a hard failure, there is a risk
 113          * of silent data-loss if the SCSI client has *not* performed a
 114          * forced unit access (FUA) write, or issued SYNCHRONIZE_CACHE
 115          * to write-out the entire device cache.
 116          */
 117         if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
 118                 pr_debug("FILEIO: Disabling O_DSYNC, using buffered FILEIO\n");
 119                 flags &= ~O_DSYNC;
 120         }
 121
 122         file = filp_open(fd_dev->fd_dev_name, flags, 0600);
 123         if (IS_ERR(file)) {
 124                 pr_err("filp_open(%s) failed\n", fd_dev->fd_dev_name);
 125                 ret = PTR_ERR(file);
 126                 goto fail;
 127         }
 128         fd_dev->fd_file = file;
 129         /*
 130          * If using a block backend with this struct file, we extract
 131          * fd_dev->fd_[block,dev]_size from struct block_device.
 132          *
 133          * Otherwise, we use the passed fd_size= from configfs
 134          */
 135         inode = file->f_mapping->host;
 136         if (S_ISBLK(inode->i_mode)) {
 137                 struct request_queue *q = bdev_get_queue(I_BDEV(inode));
 138                 unsigned long long dev_size;
 139
 140                 fd_dev->fd_block_size = bdev_logical_block_size(I_BDEV(inode));
 141                 /*
 142                  * Determine the number of bytes from i_size_read() minus
 143                  * one (1) logical sector from underlying struct block_device
 144                  */
 145                 dev_size = (i_size_read(file->f_mapping->host) -
 146                                        fd_dev->fd_block_size);
 147
 148                 pr_debug("FILEIO: Using size: %llu bytes from struct"
 149                         " block_device blocks: %llu logical_block_size: %d\n",
 150                         dev_size, div_u64(dev_size, fd_dev->fd_block_size),
 151                         fd_dev->fd_block_size);
 152
 153                 if (target_configure_unmap_from_queue(&dev->dev_attrib, q))
 154                         pr_debug("IFILE: BLOCK Discard support available,"
 155                                  " disabled by default\n");
 156                 /*
 157                  * Enable write same emulation for IBLOCK and use 0xFFFF as
 158                  * the smaller WRITE_SAME(10) only has a two-byte block count.
 159                  */
 160                 dev->dev_attrib.max_write_same_len = 0xFFFF;
 161
 162                 if (blk_queue_nonrot(q))
 163                         dev->dev_attrib.is_nonrot = 1;
 164         } else {
 165                 if (!(fd_dev->fbd_flags & FBDF_HAS_SIZE)) {
 166                         pr_err("FILEIO: Missing fd_dev_size="
 167                                 " parameter, and no backing struct"
 168                                 " block_device\n");
 169                         goto fail;
 170                 }
 171
 172                 fd_dev->fd_block_size = FD_BLOCKSIZE;
 173                 /*
 174                  * Limit UNMAP emulation to 8k Number of LBAs (NoLB)
 175                  */
 176                 dev->dev_attrib.max_unmap_lba_count = 0x2000;
 177                 /*
 178                  * Currently hardcoded to 1 in Linux/SCSI code..
 179                  */
 180                 dev->dev_attrib.max_unmap_block_desc_count = 1;
 181                 dev->dev_attrib.unmap_granularity = 1;
 182                 dev->dev_attrib.unmap_granularity_alignment = 0;
 183
 184                 /*
 185                  * Limit WRITE_SAME w/ UNMAP=0 emulation to 8k Number of LBAs (NoLB)
 186                  * based upon struct iovec limit for vfs_writev()
 187                  */
 188                 dev->dev_attrib.max_write_same_len = 0x1000;
 189         }
 190
 191         dev->dev_attrib.hw_block_size = fd_dev->fd_block_size;
 192         dev->dev_attrib.max_bytes_per_io = FD_MAX_BYTES;
 193         dev->dev_attrib.hw_max_sectors = FD_MAX_BYTES / fd_dev->fd_block_size;
 194         dev->dev_attrib.hw_queue_depth = FD_MAX_DEVICE_QUEUE_DEPTH;
 195
 196         if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
 197                 pr_debug("FILEIO: Forcing setting of emulate_write_cache=1"
 198                         " with FDBD_HAS_BUFFERED_IO_WCE\n");
 199                 dev->dev_attrib.emulate_write_cache = 1;
 200         }
 201
 202         fd_dev->fd_dev_id = fd_host->fd_host_dev_id_count++;
 203         fd_dev->fd_queue_depth = dev->queue_depth;
 204
 205         pr_debug("CORE_FILE[%u] - Added TCM FILEIO Device ID: %u at %s,"
 206                 " %llu total bytes\n", fd_host->fd_host_id, fd_dev->fd_dev_id,
 207                         fd_dev->fd_dev_name, fd_dev->fd_dev_size);
 208
 209         return 0;
 210 fail:
 211         if (fd_dev->fd_file) {
 212                 filp_close(fd_dev->fd_file, NULL);
 213                 fd_dev->fd_file = NULL;
 214         }
 215         return ret;
 216 }
 217
 218 static void fd_dev_call_rcu(struct rcu_head *p)
 219 {
 220         struct se_device *dev = container_of(p, struct se_device, rcu_head);
 221         struct fd_dev *fd_dev = FD_DEV(dev);
 222
 223         kfree(fd_dev);
 224 }
 225
 226 static void fd_free_device(struct se_device *dev)
 227 {
 228         call_rcu(&dev->rcu_head, fd_dev_call_rcu);
 229 }
 230
 231 static void fd_destroy_device(struct se_device *dev)
 232 {
 233         struct fd_dev *fd_dev = FD_DEV(dev);
 234
 235         if (fd_dev->fd_file) {
 236                 filp_close(fd_dev->fd_file, NULL);
 237                 fd_dev->fd_file = NULL;
 238         }
 239 }
 240
 241 struct target_core_file_cmd {
 242         unsigned long   len;
 243         struct se_cmd   *cmd;
 244         struct kiocb    iocb;
 245         struct bio_vec  bvecs[];
 246 };
 247
 248 static void cmd_rw_aio_complete(struct kiocb *iocb, long ret)
 249 {
 250         struct target_core_file_cmd *cmd;
 251
 252         cmd = container_of(iocb, struct target_core_file_cmd, iocb);
 253
 254         if (ret != cmd->len)
 255                 target_complete_cmd(cmd->cmd, SAM_STAT_CHECK_CONDITION);
 256         else
 257                 target_complete_cmd(cmd->cmd, SAM_STAT_GOOD);
 258
 259         kfree(cmd);
 260 }
 261
 262 static sense_reason_t
 263 fd_execute_rw_aio(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 264               enum dma_data_direction data_direction)
 265 {
 266         int is_write = !(data_direction == DMA_FROM_DEVICE);
 267         struct se_device *dev = cmd->se_dev;
 268         struct fd_dev *fd_dev = FD_DEV(dev);
 269         struct file *file = fd_dev->fd_file;
 270         struct target_core_file_cmd *aio_cmd;
 271         struct iov_iter iter;
 272         struct scatterlist *sg;
 273         ssize_t len = 0;
 274         int ret = 0, i;
 275
 276         aio_cmd = kmalloc(struct_size(aio_cmd, bvecs, sgl_nents), GFP_KERNEL);
 277         if (!aio_cmd)
 278                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 279
 280         for_each_sg(sgl, sg, sgl_nents, i) {
 281                 aio_cmd->bvecs[i].bv_page = sg_page(sg);
 282                 aio_cmd->bvecs[i].bv_len = sg->length;
 283                 aio_cmd->bvecs[i].bv_offset = sg->offset;
 284
 285                 len += sg->length;
 286         }
 287
 288         iov_iter_bvec(&iter, is_write, aio_cmd->bvecs, sgl_nents, len);
 289
 290         aio_cmd->cmd = cmd;
 291         aio_cmd->len = len;
 292         aio_cmd->iocb.ki_pos = cmd->t_task_lba * dev->dev_attrib.block_size;
 293         aio_cmd->iocb.ki_filp = file;
 294         aio_cmd->iocb.ki_complete = cmd_rw_aio_complete;
 295         aio_cmd->iocb.ki_flags = IOCB_DIRECT;
 296
 297         if (is_write && (cmd->se_cmd_flags & SCF_FUA))
 298                 aio_cmd->iocb.ki_flags |= IOCB_DSYNC;
 299
 300         if (is_write)
 301                 ret = call_write_iter(file, &aio_cmd->iocb, &iter);
 302         else
 303                 ret = call_read_iter(file, &aio_cmd->iocb, &iter);
 304
 305         if (ret != -EIOCBQUEUED)
 306                 cmd_rw_aio_complete(&aio_cmd->iocb, ret);
 307
 308         return 0;
 309 }
 310
 311 static int fd_do_rw(struct se_cmd *cmd, struct file *fd,
 312                     u32 block_size, struct scatterlist *sgl,
 313                     u32 sgl_nents, u32 data_length, int is_write)
 314 {
 315         struct scatterlist *sg;
 316         struct iov_iter iter;
 317         struct bio_vec *bvec;
 318         ssize_t len = 0;
 319         loff_t pos = (cmd->t_task_lba * block_size);
 320         int ret = 0, i;
 321
 322         bvec = kcalloc(sgl_nents, sizeof(struct bio_vec), GFP_KERNEL);
 323         if (!bvec) {
 324                 pr_err("Unable to allocate fd_do_readv iov[]\n");
 325                 return -ENOMEM;
 326         }
 327
 328         for_each_sg(sgl, sg, sgl_nents, i) {
 329                 bvec[i].bv_page = sg_page(sg);
 330                 bvec[i].bv_len = sg->length;
 331                 bvec[i].bv_offset = sg->offset;
 332
 333                 len += sg->length;
 334         }
 335
 336         iov_iter_bvec(&iter, READ, bvec, sgl_nents, len);
 337         if (is_write)
 338                 ret = vfs_iter_write(fd, &iter, &pos, 0);
 339         else
 340                 ret = vfs_iter_read(fd, &iter, &pos, 0);
 341
 342         if (is_write) {
 343                 if (ret < 0 || ret != data_length) {
 344                         pr_err("%s() write returned %d\n", __func__, ret);
 345                         if (ret >= 0)
 346                                 ret = -EINVAL;
 347                 }
 348         } else {
 349                 /*
 350                  * Return zeros and GOOD status even if the READ did not return
 351                  * the expected virt_size for struct file w/o a backing struct
 352                  * block_device.
 353                  */
 354                 if (S_ISBLK(file_inode(fd)->i_mode)) {
 355                         if (ret < 0 || ret != data_length) {
 356                                 pr_err("%s() returned %d, expecting %u for "
 357                                                 "S_ISBLK\n", __func__, ret,
 358                                                 data_length);
 359                                 if (ret >= 0)
 360                                         ret = -EINVAL;
 361                         }
 362                 } else {
 363                         if (ret < 0) {
 364                                 pr_err("%s() returned %d for non S_ISBLK\n",
 365                                                 __func__, ret);
 366                         } else if (ret != data_length) {
 367                                 /*
 368                                  * Short read case:
 369                                  * Probably some one truncate file under us.
 370                                  * We must explicitly zero sg-pages to prevent
 371                                  * expose uninizialized pages to userspace.
 372                                  */
 373                                 if (ret < data_length)
 374                                         ret += iov_iter_zero(data_length - ret, &iter);
 375                                 else
 376                                         ret = -EINVAL;
 377                         }
 378                 }
 379         }
 380         kfree(bvec);
 381         return ret;
 382 }
 383
 384 static sense_reason_t
 385 fd_execute_sync_cache(struct se_cmd *cmd)
 386 {
 387         struct se_device *dev = cmd->se_dev;
 388         struct fd_dev *fd_dev = FD_DEV(dev);
 389         int immed = (cmd->t_task_cdb[1] & 0x2);
 390         loff_t start, end;
 391         int ret;
 392
 393         /*
 394          * If the Immediate bit is set, queue up the GOOD response
 395          * for this SYNCHRONIZE_CACHE op
 396          */
 397         if (immed)
 398                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 399
 400         /*
 401          * Determine if we will be flushing the entire device.
 402          */
 403         if (cmd->t_task_lba == 0 && cmd->data_length == 0) {
 404                 start = 0;
 405                 end = LLONG_MAX;
 406         } else {
 407                 start = cmd->t_task_lba * dev->dev_attrib.block_size;
 408                 if (cmd->data_length)
 409                         end = start + cmd->data_length - 1;
 410                 else
 411                         end = LLONG_MAX;
 412         }
 413
 414         ret = vfs_fsync_range(fd_dev->fd_file, start, end, 1);
 415         if (ret != 0)
 416                 pr_err("FILEIO: vfs_fsync_range() failed: %d\n", ret);
 417
 418         if (immed)
 419                 return 0;
 420
 421         if (ret)
 422                 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
 423         else
 424                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 425
 426         return 0;
 427 }
 428
 429 static sense_reason_t
 430 fd_execute_write_same(struct se_cmd *cmd)
 431 {
 432         struct se_device *se_dev = cmd->se_dev;
 433         struct fd_dev *fd_dev = FD_DEV(se_dev);
 434         loff_t pos = cmd->t_task_lba * se_dev->dev_attrib.block_size;
 435         sector_t nolb = sbc_get_write_same_sectors(cmd);
 436         struct iov_iter iter;
 437         struct bio_vec *bvec;
 438         unsigned int len = 0, i;
 439         ssize_t ret;
 440
 441         if (!nolb) {
 442                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 443                 return 0;
 444         }
 445         if (cmd->prot_op) {
 446                 pr_err("WRITE_SAME: Protection information with FILEIO"
 447                        " backends not supported\n");
 448                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 449         }
 450
 451         if (cmd->t_data_nents > 1 ||
 452             cmd->t_data_sg[0].length != cmd->se_dev->dev_attrib.block_size) {
 453                 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
 454                         " block_size: %u\n",
 455                         cmd->t_data_nents,
 456                         cmd->t_data_sg[0].length,
 457                         cmd->se_dev->dev_attrib.block_size);
 458                 return TCM_INVALID_CDB_FIELD;
 459         }
 460
 461         bvec = kcalloc(nolb, sizeof(struct bio_vec), GFP_KERNEL);
 462         if (!bvec)
 463                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 464
 465         for (i = 0; i < nolb; i++) {
 466                 bvec[i].bv_page = sg_page(&cmd->t_data_sg[0]);
 467                 bvec[i].bv_len = cmd->t_data_sg[0].length;
 468                 bvec[i].bv_offset = cmd->t_data_sg[0].offset;
 469
 470                 len += se_dev->dev_attrib.block_size;
 471         }
 472
 473         iov_iter_bvec(&iter, READ, bvec, nolb, len);
 474         ret = vfs_iter_write(fd_dev->fd_file, &iter, &pos, 0);
 475
 476         kfree(bvec);
 477         if (ret < 0 || ret != len) {
 478                 pr_err("vfs_iter_write() returned %zd for write same\n", ret);
 479                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 480         }
 481
 482         target_complete_cmd(cmd, SAM_STAT_GOOD);
 483         return 0;
 484 }
 485
 486 static int
 487 fd_do_prot_fill(struct se_device *se_dev, sector_t lba, sector_t nolb,
 488                 void *buf, size_t bufsize)
 489 {
 490         struct fd_dev *fd_dev = FD_DEV(se_dev);
 491         struct file *prot_fd = fd_dev->fd_prot_file;
 492         sector_t prot_length, prot;
 493         loff_t pos = lba * se_dev->prot_length;
 494
 495         if (!prot_fd) {
 496                 pr_err("Unable to locate fd_dev->fd_prot_file\n");
 497                 return -ENODEV;
 498         }
 499
 500         prot_length = nolb * se_dev->prot_length;
 501
 502         memset(buf, 0xff, bufsize);
 503         for (prot = 0; prot < prot_length;) {
 504                 sector_t len = min_t(sector_t, bufsize, prot_length - prot);
 505                 ssize_t ret = kernel_write(prot_fd, buf, len, &pos);
 506
 507                 if (ret != len) {
 508                         pr_err("vfs_write to prot file failed: %zd\n", ret);
 509                         return ret < 0 ? ret : -ENODEV;
 510                 }
 511                 prot += ret;
 512         }
 513
 514         return 0;
 515 }
 516
 517 static int
 518 fd_do_prot_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
 519 {
 520         void *buf;
 521         int rc;
 522
 523         buf = (void *)__get_free_page(GFP_KERNEL);
 524         if (!buf) {
 525                 pr_err("Unable to allocate FILEIO prot buf\n");
 526                 return -ENOMEM;
 527         }
 528
 529         rc = fd_do_prot_fill(cmd->se_dev, lba, nolb, buf, PAGE_SIZE);
 530
 531         free_page((unsigned long)buf);
 532
 533         return rc;
 534 }
 535
 536 static sense_reason_t
 537 fd_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
 538 {
 539         struct file *file = FD_DEV(cmd->se_dev)->fd_file;
 540         struct inode *inode = file->f_mapping->host;
 541         int ret;
 542
 543         if (!nolb) {
 544                 return 0;
 545         }
 546
 547         if (cmd->se_dev->dev_attrib.pi_prot_type) {
 548                 ret = fd_do_prot_unmap(cmd, lba, nolb);
 549                 if (ret)
 550                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 551         }
 552
 553         if (S_ISBLK(inode->i_mode)) {
 554                 /* The backend is block device, use discard */
 555                 struct block_device *bdev = I_BDEV(inode);
 556                 struct se_device *dev = cmd->se_dev;
 557
 558                 ret = blkdev_issue_discard(bdev,
 559                                            target_to_linux_sector(dev, lba),
 560                                            target_to_linux_sector(dev,  nolb),
 561                                            GFP_KERNEL, 0);
 562                 if (ret < 0) {
 563                         pr_warn("FILEIO: blkdev_issue_discard() failed: %d\n",
 564                                 ret);
 565                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 566                 }
 567         } else {
 568                 /* The backend is normal file, use fallocate */
 569                 struct se_device *se_dev = cmd->se_dev;
 570                 loff_t pos = lba * se_dev->dev_attrib.block_size;
 571                 unsigned int len = nolb * se_dev->dev_attrib.block_size;
 572                 int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
 573
 574                 if (!file->f_op->fallocate)
 575                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 576
 577                 ret = file->f_op->fallocate(file, mode, pos, len);
 578                 if (ret < 0) {
 579                         pr_warn("FILEIO: fallocate() failed: %d\n", ret);
 580                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 581                 }
 582         }
 583
 584         return 0;
 585 }
 586
 587 static sense_reason_t
 588 fd_execute_rw_buffered(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 589               enum dma_data_direction data_direction)
 590 {
 591         struct se_device *dev = cmd->se_dev;
 592         struct fd_dev *fd_dev = FD_DEV(dev);
 593         struct file *file = fd_dev->fd_file;
 594         struct file *pfile = fd_dev->fd_prot_file;
 595         sense_reason_t rc;
 596         int ret = 0;
 597         /*
 598          * Call vectorized fileio functions to map struct scatterlist
 599          * physical memory addresses to struct iovec virtual memory.
 600          */
 601         if (data_direction == DMA_FROM_DEVICE) {
 602                 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 603                         ret = fd_do_rw(cmd, pfile, dev->prot_length,
 604                                        cmd->t_prot_sg, cmd->t_prot_nents,
 605                                        cmd->prot_length, 0);
 606                         if (ret < 0)
 607                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 608                 }
 609
 610                 ret = fd_do_rw(cmd, file, dev->dev_attrib.block_size,
 611                                sgl, sgl_nents, cmd->data_length, 0);
 612
 613                 if (ret > 0 && cmd->prot_type && dev->dev_attrib.pi_prot_type &&
 614                     dev->dev_attrib.pi_prot_verify) {
 615                         u32 sectors = cmd->data_length >>
 616                                         ilog2(dev->dev_attrib.block_size);
 617
 618                         rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors,
 619                                             0, cmd->t_prot_sg, 0);
 620                         if (rc)
 621                                 return rc;
 622                 }
 623         } else {
 624                 if (cmd->prot_type && dev->dev_attrib.pi_prot_type &&
 625                     dev->dev_attrib.pi_prot_verify) {
 626                         u32 sectors = cmd->data_length >>
 627                                         ilog2(dev->dev_attrib.block_size);
 628
 629                         rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors,
 630                                             0, cmd->t_prot_sg, 0);
 631                         if (rc)
 632                                 return rc;
 633                 }
 634
 635                 ret = fd_do_rw(cmd, file, dev->dev_attrib.block_size,
 636                                sgl, sgl_nents, cmd->data_length, 1);
 637                 /*
 638                  * Perform implicit vfs_fsync_range() for fd_do_writev() ops
 639                  * for SCSI WRITEs with Forced Unit Access (FUA) set.
 640                  * Allow this to happen independent of WCE=0 setting.
 641                  */
 642                 if (ret > 0 && (cmd->se_cmd_flags & SCF_FUA)) {
 643                         loff_t start = cmd->t_task_lba *
 644                                 dev->dev_attrib.block_size;
 645                         loff_t end;
 646
 647                         if (cmd->data_length)
 648                                 end = start + cmd->data_length - 1;
 649                         else
 650                                 end = LLONG_MAX;
 651
 652                         vfs_fsync_range(fd_dev->fd_file, start, end, 1);
 653                 }
 654
 655                 if (ret > 0 && cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 656                         ret = fd_do_rw(cmd, pfile, dev->prot_length,
 657                                        cmd->t_prot_sg, cmd->t_prot_nents,
 658                                        cmd->prot_length, 1);
 659                         if (ret < 0)
 660                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 661                 }
 662         }
 663
 664         if (ret < 0)
 665                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 666
 667         target_complete_cmd(cmd, SAM_STAT_GOOD);
 668         return 0;
 669 }
 670
 671 static sense_reason_t
 672 fd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 673               enum dma_data_direction data_direction)
 674 {
 675         struct se_device *dev = cmd->se_dev;
 676         struct fd_dev *fd_dev = FD_DEV(dev);
 677
 678         /*
 679          * We are currently limited by the number of iovecs (2048) per
 680          * single vfs_[writev,readv] call.
 681          */
 682         if (cmd->data_length > FD_MAX_BYTES) {
 683                 pr_err("FILEIO: Not able to process I/O of %u bytes due to"
 684                        "FD_MAX_BYTES: %u iovec count limitation\n",
 685                         cmd->data_length, FD_MAX_BYTES);
 686                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 687         }
 688
 689         if (fd_dev->fbd_flags & FDBD_HAS_ASYNC_IO)
 690                 return fd_execute_rw_aio(cmd, sgl, sgl_nents, data_direction);
 691         return fd_execute_rw_buffered(cmd, sgl, sgl_nents, data_direction);
 692 }
 693
 694 enum {
 695         Opt_fd_dev_name, Opt_fd_dev_size, Opt_fd_buffered_io,
 696         Opt_fd_async_io, Opt_err
 697 };
 698
 699 static match_table_t tokens = {
 700         {Opt_fd_dev_name, "fd_dev_name=%s"},
 701         {Opt_fd_dev_size, "fd_dev_size=%s"},
 702         {Opt_fd_buffered_io, "fd_buffered_io=%d"},
 703         {Opt_fd_async_io, "fd_async_io=%d"},
 704         {Opt_err, NULL}
 705 };
 706
 707 static ssize_t fd_set_configfs_dev_params(struct se_device *dev,
 708                 const char *page, ssize_t count)
 709 {
 710         struct fd_dev *fd_dev = FD_DEV(dev);
 711         char *orig, *ptr, *arg_p, *opts;
 712         substring_t args[MAX_OPT_ARGS];
 713         int ret = 0, arg, token;
 714
 715         opts = kstrdup(page, GFP_KERNEL);
 716         if (!opts)
 717                 return -ENOMEM;
 718
 719         orig = opts;
 720
 721         while ((ptr = strsep(&opts, ",\n")) != NULL) {
 722                 if (!*ptr)
 723                         continue;
 724
 725                 token = match_token(ptr, tokens, args);
 726                 switch (token) {
 727                 case Opt_fd_dev_name:
 728                         if (match_strlcpy(fd_dev->fd_dev_name, &args[0],
 729                                 FD_MAX_DEV_NAME) == 0) {
 730                                 ret = -EINVAL;
 731                                 break;
 732                         }
 733                         pr_debug("FILEIO: Referencing Path: %s\n",
 734                                         fd_dev->fd_dev_name);
 735                         fd_dev->fbd_flags |= FBDF_HAS_PATH;
 736                         break;
 737                 case Opt_fd_dev_size:
 738                         arg_p = match_strdup(&args[0]);
 739                         if (!arg_p) {
 740                                 ret = -ENOMEM;
 741                                 break;
 742                         }
 743                         ret = kstrtoull(arg_p, 0, &fd_dev->fd_dev_size);
 744                         kfree(arg_p);
 745                         if (ret < 0) {
 746                                 pr_err("kstrtoull() failed for"
 747                                                 " fd_dev_size=\n");
 748                                 goto out;
 749                         }
 750                         pr_debug("FILEIO: Referencing Size: %llu"
 751                                         " bytes\n", fd_dev->fd_dev_size);
 752                         fd_dev->fbd_flags |= FBDF_HAS_SIZE;
 753                         break;
 754                 case Opt_fd_buffered_io:
 755                         ret = match_int(args, &arg);
 756                         if (ret)
 757                                 goto out;
 758                         if (arg != 1) {
 759                                 pr_err("bogus fd_buffered_io=%d value\n", arg);
 760                                 ret = -EINVAL;
 761                                 goto out;
 762                         }
 763
 764                         pr_debug("FILEIO: Using buffered I/O"
 765                                 " operations for struct fd_dev\n");
 766
 767                         fd_dev->fbd_flags |= FDBD_HAS_BUFFERED_IO_WCE;
 768                         break;
 769                 case Opt_fd_async_io:
 770                         ret = match_int(args, &arg);
 771                         if (ret)
 772                                 goto out;
 773                         if (arg != 1) {
 774                                 pr_err("bogus fd_async_io=%d value\n", arg);
 775                                 ret = -EINVAL;
 776                                 goto out;
 777                         }
 778
 779                         pr_debug("FILEIO: Using async I/O"
 780                                 " operations for struct fd_dev\n");
 781
 782                         fd_dev->fbd_flags |= FDBD_HAS_ASYNC_IO;
 783                         break;
 784                 default:
 785                         break;
 786                 }
 787         }
 788
 789 out:
 790         kfree(orig);
 791         return (!ret) ? count : ret;
 792 }
 793
 794 static ssize_t fd_show_configfs_dev_params(struct se_device *dev, char *b)
 795 {
 796         struct fd_dev *fd_dev = FD_DEV(dev);
 797         ssize_t bl = 0;
 798
 799         bl = sprintf(b + bl, "TCM FILEIO ID: %u", fd_dev->fd_dev_id);
 800         bl += sprintf(b + bl, "        File: %s  Size: %llu  Mode: %s Async: %d\n",
 801                 fd_dev->fd_dev_name, fd_dev->fd_dev_size,
 802                 (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) ?
 803                 "Buffered-WCE" : "O_DSYNC",
 804                 !!(fd_dev->fbd_flags & FDBD_HAS_ASYNC_IO));
 805         return bl;
 806 }
 807
 808 static sector_t fd_get_blocks(struct se_device *dev)
 809 {
 810         struct fd_dev *fd_dev = FD_DEV(dev);
 811         struct file *f = fd_dev->fd_file;
 812         struct inode *i = f->f_mapping->host;
 813         unsigned long long dev_size;
 814         /*
 815          * When using a file that references an underlying struct block_device,
 816          * ensure dev_size is always based on the current inode size in order
 817          * to handle underlying block_device resize operations.
 818          */
 819         if (S_ISBLK(i->i_mode))
 820                 dev_size = i_size_read(i);
 821         else
 822                 dev_size = fd_dev->fd_dev_size;
 823
 824         return div_u64(dev_size - dev->dev_attrib.block_size,
 825                        dev->dev_attrib.block_size);
 826 }
 827
 828 static int fd_init_prot(struct se_device *dev)
 829 {
 830         struct fd_dev *fd_dev = FD_DEV(dev);
 831         struct file *prot_file, *file = fd_dev->fd_file;
 832         struct inode *inode;
 833         int ret, flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
 834         char buf[FD_MAX_DEV_PROT_NAME];
 835
 836         if (!file) {
 837                 pr_err("Unable to locate fd_dev->fd_file\n");
 838                 return -ENODEV;
 839         }
 840
 841         inode = file->f_mapping->host;
 842         if (S_ISBLK(inode->i_mode)) {
 843                 pr_err("FILEIO Protection emulation only supported on"
 844                        " !S_ISBLK\n");
 845                 return -ENOSYS;
 846         }
 847
 848         if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE)
 849                 flags &= ~O_DSYNC;
 850
 851         snprintf(buf, FD_MAX_DEV_PROT_NAME, "%s.protection",
 852                  fd_dev->fd_dev_name);
 853
 854         prot_file = filp_open(buf, flags, 0600);
 855         if (IS_ERR(prot_file)) {
 856                 pr_err("filp_open(%s) failed\n", buf);
 857                 ret = PTR_ERR(prot_file);
 858                 return ret;
 859         }
 860         fd_dev->fd_prot_file = prot_file;
 861
 862         return 0;
 863 }
 864
 865 static int fd_format_prot(struct se_device *dev)
 866 {
 867         unsigned char *buf;
 868         int unit_size = FDBD_FORMAT_UNIT_SIZE * dev->dev_attrib.block_size;
 869         int ret;
 870
 871         if (!dev->dev_attrib.pi_prot_type) {
 872                 pr_err("Unable to format_prot while pi_prot_type == 0\n");
 873                 return -ENODEV;
 874         }
 875
 876         buf = vzalloc(unit_size);
 877         if (!buf) {
 878                 pr_err("Unable to allocate FILEIO prot buf\n");
 879                 return -ENOMEM;
 880         }
 881
 882         pr_debug("Using FILEIO prot_length: %llu\n",
 883                  (unsigned long long)(dev->transport->get_blocks(dev) + 1) *
 884                                         dev->prot_length);
 885
 886         ret = fd_do_prot_fill(dev, 0, dev->transport->get_blocks(dev) + 1,
 887                               buf, unit_size);
 888         vfree(buf);
 889         return ret;
 890 }
 891
 892 static void fd_free_prot(struct se_device *dev)
 893 {
 894         struct fd_dev *fd_dev = FD_DEV(dev);
 895
 896         if (!fd_dev->fd_prot_file)
 897                 return;
 898
 899         filp_close(fd_dev->fd_prot_file, NULL);
 900         fd_dev->fd_prot_file = NULL;
 901 }
 902
 903 static struct sbc_ops fd_sbc_ops = {
 904         .execute_rw             = fd_execute_rw,
 905         .execute_sync_cache     = fd_execute_sync_cache,
 906         .execute_write_same     = fd_execute_write_same,
 907         .execute_unmap          = fd_execute_unmap,
 908 };
 909
 910 static sense_reason_t
 911 fd_parse_cdb(struct se_cmd *cmd)
 912 {
 913         return sbc_parse_cdb(cmd, &fd_sbc_ops);
 914 }
 915
 916 static const struct target_backend_ops fileio_ops = {
 917         .name                   = "fileio",
 918         .inquiry_prod           = "FILEIO",
 919         .inquiry_rev            = FD_VERSION,
 920         .owner                  = THIS_MODULE,
 921         .attach_hba             = fd_attach_hba,
 922         .detach_hba             = fd_detach_hba,
 923         .alloc_device           = fd_alloc_device,
 924         .configure_device       = fd_configure_device,
 925         .destroy_device         = fd_destroy_device,
 926         .free_device            = fd_free_device,
 927         .parse_cdb              = fd_parse_cdb,
 928         .set_configfs_dev_params = fd_set_configfs_dev_params,
 929         .show_configfs_dev_params = fd_show_configfs_dev_params,
 930         .get_device_type        = sbc_get_device_type,
 931         .get_blocks             = fd_get_blocks,
 932         .init_prot              = fd_init_prot,
 933         .format_prot            = fd_format_prot,
 934         .free_prot              = fd_free_prot,
 935         .tb_dev_attrib_attrs    = sbc_attrib_attrs,
 936 };
 937
 938 static int __init fileio_module_init(void)
 939 {
 940         return transport_backend_register(&fileio_ops);
 941 }
 942
 943 static void __exit fileio_module_exit(void)
 944 {
 945         target_backend_unregister(&fileio_ops);
 946 }
 947
 948 MODULE_DESCRIPTION("TCM FILEIO subsystem plugin");
 949 MODULE_AUTHOR("[email protected]");
 950 MODULE_LICENSE("GPL");
 951
 952 module_init(fileio_module_init);
 953 module_exit(fileio_module_exit);