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 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                 aio_cmd->bvecs[i].bv_page = sg_page(sg);
 285                 aio_cmd->bvecs[i].bv_len = sg->length;
 286                 aio_cmd->bvecs[i].bv_offset = sg->offset;
 287
 288                 len += sg->length;
 289         }
 290
 291         iov_iter_bvec(&iter, is_write, aio_cmd->bvecs, sgl_nents, len);
 292
 293         aio_cmd->cmd = cmd;
 294         aio_cmd->len = len;
 295         aio_cmd->iocb.ki_pos = cmd->t_task_lba * dev->dev_attrib.block_size;
 296         aio_cmd->iocb.ki_filp = file;
 297         aio_cmd->iocb.ki_complete = cmd_rw_aio_complete;
 298         aio_cmd->iocb.ki_flags = IOCB_DIRECT;
 299
 300         if (is_write && (cmd->se_cmd_flags & SCF_FUA))
 301                 aio_cmd->iocb.ki_flags |= IOCB_DSYNC;
 302
 303         if (is_write)
 304                 ret = call_write_iter(file, &aio_cmd->iocb, &iter);
 305         else
 306                 ret = call_read_iter(file, &aio_cmd->iocb, &iter);
 307
 308         if (ret != -EIOCBQUEUED)
 309                 cmd_rw_aio_complete(&aio_cmd->iocb, ret);
 310
 311         return 0;
 312 }
 313
 314 static int fd_do_rw(struct se_cmd *cmd, struct file *fd,
 315                     u32 block_size, struct scatterlist *sgl,
 316                     u32 sgl_nents, u32 data_length, int is_write)
 317 {
 318         struct scatterlist *sg;
 319         struct iov_iter iter;
 320         struct bio_vec *bvec;
 321         ssize_t len = 0;
 322         loff_t pos = (cmd->t_task_lba * block_size);
 323         int ret = 0, i;
 324
 325         bvec = kcalloc(sgl_nents, sizeof(struct bio_vec), GFP_KERNEL);
 326         if (!bvec) {
 327                 pr_err("Unable to allocate fd_do_readv iov[]\n");
 328                 return -ENOMEM;
 329         }
 330
 331         for_each_sg(sgl, sg, sgl_nents, i) {
 332                 bvec[i].bv_page = sg_page(sg);
 333                 bvec[i].bv_len = sg->length;
 334                 bvec[i].bv_offset = sg->offset;
 335
 336                 len += sg->length;
 337         }
 338
 339         iov_iter_bvec(&iter, is_write, bvec, sgl_nents, len);
 340         if (is_write)
 341                 ret = vfs_iter_write(fd, &iter, &pos, 0);
 342         else
 343                 ret = vfs_iter_read(fd, &iter, &pos, 0);
 344
 345         if (is_write) {
 346                 if (ret < 0 || ret != data_length) {
 347                         pr_err("%s() write returned %d\n", __func__, ret);
 348                         if (ret >= 0)
 349                                 ret = -EINVAL;
 350                 }
 351         } else {
 352                 /*
 353                  * Return zeros and GOOD status even if the READ did not return
 354                  * the expected virt_size for struct file w/o a backing struct
 355                  * block_device.
 356                  */
 357                 if (S_ISBLK(file_inode(fd)->i_mode)) {
 358                         if (ret < 0 || ret != data_length) {
 359                                 pr_err("%s() returned %d, expecting %u for "
 360                                                 "S_ISBLK\n", __func__, ret,
 361                                                 data_length);
 362                                 if (ret >= 0)
 363                                         ret = -EINVAL;
 364                         }
 365                 } else {
 366                         if (ret < 0) {
 367                                 pr_err("%s() returned %d for non S_ISBLK\n",
 368                                                 __func__, ret);
 369                         } else if (ret != data_length) {
 370                                 /*
 371                                  * Short read case:
 372                                  * Probably some one truncate file under us.
 373                                  * We must explicitly zero sg-pages to prevent
 374                                  * expose uninizialized pages to userspace.
 375                                  */
 376                                 if (ret < data_length)
 377                                         ret += iov_iter_zero(data_length - ret, &iter);
 378                                 else
 379                                         ret = -EINVAL;
 380                         }
 381                 }
 382         }
 383         kfree(bvec);
 384         return ret;
 385 }
 386
 387 static sense_reason_t
 388 fd_execute_sync_cache(struct se_cmd *cmd)
 389 {
 390         struct se_device *dev = cmd->se_dev;
 391         struct fd_dev *fd_dev = FD_DEV(dev);
 392         int immed = (cmd->t_task_cdb[1] & 0x2);
 393         loff_t start, end;
 394         int ret;
 395
 396         /*
 397          * If the Immediate bit is set, queue up the GOOD response
 398          * for this SYNCHRONIZE_CACHE op
 399          */
 400         if (immed)
 401                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 402
 403         /*
 404          * Determine if we will be flushing the entire device.
 405          */
 406         if (cmd->t_task_lba == 0 && cmd->data_length == 0) {
 407                 start = 0;
 408                 end = LLONG_MAX;
 409         } else {
 410                 start = cmd->t_task_lba * dev->dev_attrib.block_size;
 411                 if (cmd->data_length)
 412                         end = start + cmd->data_length - 1;
 413                 else
 414                         end = LLONG_MAX;
 415         }
 416
 417         ret = vfs_fsync_range(fd_dev->fd_file, start, end, 1);
 418         if (ret != 0)
 419                 pr_err("FILEIO: vfs_fsync_range() failed: %d\n", ret);
 420
 421         if (immed)
 422                 return 0;
 423
 424         if (ret)
 425                 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
 426         else
 427                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 428
 429         return 0;
 430 }
 431
 432 static sense_reason_t
 433 fd_execute_write_same(struct se_cmd *cmd)
 434 {
 435         struct se_device *se_dev = cmd->se_dev;
 436         struct fd_dev *fd_dev = FD_DEV(se_dev);
 437         loff_t pos = cmd->t_task_lba * se_dev->dev_attrib.block_size;
 438         sector_t nolb = sbc_get_write_same_sectors(cmd);
 439         struct iov_iter iter;
 440         struct bio_vec *bvec;
 441         unsigned int len = 0, i;
 442         ssize_t ret;
 443
 444         if (cmd->prot_op) {
 445                 pr_err("WRITE_SAME: Protection information with FILEIO"
 446                        " backends not supported\n");
 447                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 448         }
 449
 450         if (!cmd->t_data_nents)
 451                 return TCM_INVALID_CDB_FIELD;
 452
 453         if (cmd->t_data_nents > 1 ||
 454             cmd->t_data_sg[0].length != cmd->se_dev->dev_attrib.block_size) {
 455                 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
 456                         " block_size: %u\n",
 457                         cmd->t_data_nents,
 458                         cmd->t_data_sg[0].length,
 459                         cmd->se_dev->dev_attrib.block_size);
 460                 return TCM_INVALID_CDB_FIELD;
 461         }
 462
 463         bvec = kcalloc(nolb, sizeof(struct bio_vec), GFP_KERNEL);
 464         if (!bvec)
 465                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 466
 467         for (i = 0; i < nolb; i++) {
 468                 bvec[i].bv_page = sg_page(&cmd->t_data_sg[0]);
 469                 bvec[i].bv_len = cmd->t_data_sg[0].length;
 470                 bvec[i].bv_offset = cmd->t_data_sg[0].offset;
 471
 472                 len += se_dev->dev_attrib.block_size;
 473         }
 474
 475         iov_iter_bvec(&iter, ITER_SOURCE, bvec, nolb, len);
 476         ret = vfs_iter_write(fd_dev->fd_file, &iter, &pos, 0);
 477
 478         kfree(bvec);
 479         if (ret < 0 || ret != len) {
 480                 pr_err("vfs_iter_write() returned %zd for write same\n", ret);
 481                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 482         }
 483
 484         target_complete_cmd(cmd, SAM_STAT_GOOD);
 485         return 0;
 486 }
 487
 488 static int
 489 fd_do_prot_fill(struct se_device *se_dev, sector_t lba, sector_t nolb,
 490                 void *buf, size_t bufsize)
 491 {
 492         struct fd_dev *fd_dev = FD_DEV(se_dev);
 493         struct file *prot_fd = fd_dev->fd_prot_file;
 494         sector_t prot_length, prot;
 495         loff_t pos = lba * se_dev->prot_length;
 496
 497         if (!prot_fd) {
 498                 pr_err("Unable to locate fd_dev->fd_prot_file\n");
 499                 return -ENODEV;
 500         }
 501
 502         prot_length = nolb * se_dev->prot_length;
 503
 504         memset(buf, 0xff, bufsize);
 505         for (prot = 0; prot < prot_length;) {
 506                 sector_t len = min_t(sector_t, bufsize, prot_length - prot);
 507                 ssize_t ret = kernel_write(prot_fd, buf, len, &pos);
 508
 509                 if (ret != len) {
 510                         pr_err("vfs_write to prot file failed: %zd\n", ret);
 511                         return ret < 0 ? ret : -ENODEV;
 512                 }
 513                 prot += ret;
 514         }
 515
 516         return 0;
 517 }
 518
 519 static int
 520 fd_do_prot_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
 521 {
 522         void *buf;
 523         int rc;
 524
 525         buf = (void *)__get_free_page(GFP_KERNEL);
 526         if (!buf) {
 527                 pr_err("Unable to allocate FILEIO prot buf\n");
 528                 return -ENOMEM;
 529         }
 530
 531         rc = fd_do_prot_fill(cmd->se_dev, lba, nolb, buf, PAGE_SIZE);
 532
 533         free_page((unsigned long)buf);
 534
 535         return rc;
 536 }
 537
 538 static sense_reason_t
 539 fd_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
 540 {
 541         struct file *file = FD_DEV(cmd->se_dev)->fd_file;
 542         struct inode *inode = file->f_mapping->host;
 543         int ret;
 544
 545         if (!nolb) {
 546                 return 0;
 547         }
 548
 549         if (cmd->se_dev->dev_attrib.pi_prot_type) {
 550                 ret = fd_do_prot_unmap(cmd, lba, nolb);
 551                 if (ret)
 552                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 553         }
 554
 555         if (S_ISBLK(inode->i_mode)) {
 556                 /* The backend is block device, use discard */
 557                 struct block_device *bdev = I_BDEV(inode);
 558                 struct se_device *dev = cmd->se_dev;
 559
 560                 ret = blkdev_issue_discard(bdev,
 561                                            target_to_linux_sector(dev, lba),
 562                                            target_to_linux_sector(dev,  nolb),
 563                                            GFP_KERNEL);
 564                 if (ret < 0) {
 565                         pr_warn("FILEIO: blkdev_issue_discard() failed: %d\n",
 566                                 ret);
 567                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 568                 }
 569         } else {
 570                 /* The backend is normal file, use fallocate */
 571                 struct se_device *se_dev = cmd->se_dev;
 572                 loff_t pos = lba * se_dev->dev_attrib.block_size;
 573                 unsigned int len = nolb * se_dev->dev_attrib.block_size;
 574                 int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
 575
 576                 if (!file->f_op->fallocate)
 577                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 578
 579                 ret = file->f_op->fallocate(file, mode, pos, len);
 580                 if (ret < 0) {
 581                         pr_warn("FILEIO: fallocate() failed: %d\n", ret);
 582                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 583                 }
 584         }
 585
 586         return 0;
 587 }
 588
 589 static sense_reason_t
 590 fd_execute_rw_buffered(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 591               enum dma_data_direction data_direction)
 592 {
 593         struct se_device *dev = cmd->se_dev;
 594         struct fd_dev *fd_dev = FD_DEV(dev);
 595         struct file *file = fd_dev->fd_file;
 596         struct file *pfile = fd_dev->fd_prot_file;
 597         sense_reason_t rc;
 598         int ret = 0;
 599         /*
 600          * Call vectorized fileio functions to map struct scatterlist
 601          * physical memory addresses to struct iovec virtual memory.
 602          */
 603         if (data_direction == DMA_FROM_DEVICE) {
 604                 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 605                         ret = fd_do_rw(cmd, pfile, dev->prot_length,
 606                                        cmd->t_prot_sg, cmd->t_prot_nents,
 607                                        cmd->prot_length, 0);
 608                         if (ret < 0)
 609                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 610                 }
 611
 612                 ret = fd_do_rw(cmd, file, dev->dev_attrib.block_size,
 613                                sgl, sgl_nents, cmd->data_length, 0);
 614
 615                 if (ret > 0 && cmd->prot_type && dev->dev_attrib.pi_prot_type &&
 616                     dev->dev_attrib.pi_prot_verify) {
 617                         u32 sectors = cmd->data_length >>
 618                                         ilog2(dev->dev_attrib.block_size);
 619
 620                         rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors,
 621                                             0, cmd->t_prot_sg, 0);
 622                         if (rc)
 623                                 return rc;
 624                 }
 625         } else {
 626                 if (cmd->prot_type && dev->dev_attrib.pi_prot_type &&
 627                     dev->dev_attrib.pi_prot_verify) {
 628                         u32 sectors = cmd->data_length >>
 629                                         ilog2(dev->dev_attrib.block_size);
 630
 631                         rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors,
 632                                             0, cmd->t_prot_sg, 0);
 633                         if (rc)
 634                                 return rc;
 635                 }
 636
 637                 ret = fd_do_rw(cmd, file, dev->dev_attrib.block_size,
 638                                sgl, sgl_nents, cmd->data_length, 1);
 639                 /*
 640                  * Perform implicit vfs_fsync_range() for fd_do_writev() ops
 641                  * for SCSI WRITEs with Forced Unit Access (FUA) set.
 642                  * Allow this to happen independent of WCE=0 setting.
 643                  */
 644                 if (ret > 0 && (cmd->se_cmd_flags & SCF_FUA)) {
 645                         loff_t start = cmd->t_task_lba *
 646                                 dev->dev_attrib.block_size;
 647                         loff_t end;
 648
 649                         if (cmd->data_length)
 650                                 end = start + cmd->data_length - 1;
 651                         else
 652                                 end = LLONG_MAX;
 653
 654                         vfs_fsync_range(fd_dev->fd_file, start, end, 1);
 655                 }
 656
 657                 if (ret > 0 && cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 658                         ret = fd_do_rw(cmd, pfile, dev->prot_length,
 659                                        cmd->t_prot_sg, cmd->t_prot_nents,
 660                                        cmd->prot_length, 1);
 661                         if (ret < 0)
 662                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 663                 }
 664         }
 665
 666         if (ret < 0)
 667                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 668
 669         target_complete_cmd(cmd, SAM_STAT_GOOD);
 670         return 0;
 671 }
 672
 673 static sense_reason_t
 674 fd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 675               enum dma_data_direction data_direction)
 676 {
 677         struct se_device *dev = cmd->se_dev;
 678         struct fd_dev *fd_dev = FD_DEV(dev);
 679
 680         /*
 681          * We are currently limited by the number of iovecs (2048) per
 682          * single vfs_[writev,readv] call.
 683          */
 684         if (cmd->data_length > FD_MAX_BYTES) {
 685                 pr_err("FILEIO: Not able to process I/O of %u bytes due to"
 686                        "FD_MAX_BYTES: %u iovec count limitation\n",
 687                         cmd->data_length, FD_MAX_BYTES);
 688                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 689         }
 690
 691         if (fd_dev->fbd_flags & FDBD_HAS_ASYNC_IO)
 692                 return fd_execute_rw_aio(cmd, sgl, sgl_nents, data_direction);
 693         return fd_execute_rw_buffered(cmd, sgl, sgl_nents, data_direction);
 694 }
 695
 696 enum {
 697         Opt_fd_dev_name, Opt_fd_dev_size, Opt_fd_buffered_io,
 698         Opt_fd_async_io, Opt_err
 699 };
 700
 701 static match_table_t tokens = {
 702         {Opt_fd_dev_name, "fd_dev_name=%s"},
 703         {Opt_fd_dev_size, "fd_dev_size=%s"},
 704         {Opt_fd_buffered_io, "fd_buffered_io=%d"},
 705         {Opt_fd_async_io, "fd_async_io=%d"},
 706         {Opt_err, NULL}
 707 };
 708
 709 static ssize_t fd_set_configfs_dev_params(struct se_device *dev,
 710                 const char *page, ssize_t count)
 711 {
 712         struct fd_dev *fd_dev = FD_DEV(dev);
 713         char *orig, *ptr, *arg_p, *opts;
 714         substring_t args[MAX_OPT_ARGS];
 715         int ret = 0, arg, token;
 716
 717         opts = kstrdup(page, GFP_KERNEL);
 718         if (!opts)
 719                 return -ENOMEM;
 720
 721         orig = opts;
 722
 723         while ((ptr = strsep(&opts, ",\n")) != NULL) {
 724                 if (!*ptr)
 725                         continue;
 726
 727                 token = match_token(ptr, tokens, args);
 728                 switch (token) {
 729                 case Opt_fd_dev_name:
 730                         if (match_strlcpy(fd_dev->fd_dev_name, &args[0],
 731                                 FD_MAX_DEV_NAME) == 0) {
 732                                 ret = -EINVAL;
 733                                 break;
 734                         }
 735                         pr_debug("FILEIO: Referencing Path: %s\n",
 736                                         fd_dev->fd_dev_name);
 737                         fd_dev->fbd_flags |= FBDF_HAS_PATH;
 738                         break;
 739                 case Opt_fd_dev_size:
 740                         arg_p = match_strdup(&args[0]);
 741                         if (!arg_p) {
 742                                 ret = -ENOMEM;
 743                                 break;
 744                         }
 745                         ret = kstrtoull(arg_p, 0, &fd_dev->fd_dev_size);
 746                         kfree(arg_p);
 747                         if (ret < 0) {
 748                                 pr_err("kstrtoull() failed for"
 749                                                 " fd_dev_size=\n");
 750                                 goto out;
 751                         }
 752                         pr_debug("FILEIO: Referencing Size: %llu"
 753                                         " bytes\n", fd_dev->fd_dev_size);
 754                         fd_dev->fbd_flags |= FBDF_HAS_SIZE;
 755                         break;
 756                 case Opt_fd_buffered_io:
 757                         ret = match_int(args, &arg);
 758                         if (ret)
 759                                 goto out;
 760                         if (arg != 1) {
 761                                 pr_err("bogus fd_buffered_io=%d value\n", arg);
 762                                 ret = -EINVAL;
 763                                 goto out;
 764                         }
 765
 766                         pr_debug("FILEIO: Using buffered I/O"
 767                                 " operations for struct fd_dev\n");
 768
 769                         fd_dev->fbd_flags |= FDBD_HAS_BUFFERED_IO_WCE;
 770                         break;
 771                 case Opt_fd_async_io:
 772                         ret = match_int(args, &arg);
 773                         if (ret)
 774                                 goto out;
 775                         if (arg != 1) {
 776                                 pr_err("bogus fd_async_io=%d value\n", arg);
 777                                 ret = -EINVAL;
 778                                 goto out;
 779                         }
 780
 781                         pr_debug("FILEIO: Using async I/O"
 782                                 " operations for struct fd_dev\n");
 783
 784                         fd_dev->fbd_flags |= FDBD_HAS_ASYNC_IO;
 785                         break;
 786                 default:
 787                         break;
 788                 }
 789         }
 790
 791 out:
 792         kfree(orig);
 793         return (!ret) ? count : ret;
 794 }
 795
 796 static ssize_t fd_show_configfs_dev_params(struct se_device *dev, char *b)
 797 {
 798         struct fd_dev *fd_dev = FD_DEV(dev);
 799         ssize_t bl = 0;
 800
 801         bl = sprintf(b + bl, "TCM FILEIO ID: %u", fd_dev->fd_dev_id);
 802         bl += sprintf(b + bl, "        File: %s  Size: %llu  Mode: %s Async: %d\n",
 803                 fd_dev->fd_dev_name, fd_dev->fd_dev_size,
 804                 (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) ?
 805                 "Buffered-WCE" : "O_DSYNC",
 806                 !!(fd_dev->fbd_flags & FDBD_HAS_ASYNC_IO));
 807         return bl;
 808 }
 809
 810 static sector_t fd_get_blocks(struct se_device *dev)
 811 {
 812         struct fd_dev *fd_dev = FD_DEV(dev);
 813         struct file *f = fd_dev->fd_file;
 814         struct inode *i = f->f_mapping->host;
 815         unsigned long long dev_size;
 816         /*
 817          * When using a file that references an underlying struct block_device,
 818          * ensure dev_size is always based on the current inode size in order
 819          * to handle underlying block_device resize operations.
 820          */
 821         if (S_ISBLK(i->i_mode))
 822                 dev_size = i_size_read(i);
 823         else
 824                 dev_size = fd_dev->fd_dev_size;
 825
 826         return div_u64(dev_size - dev->dev_attrib.block_size,
 827                        dev->dev_attrib.block_size);
 828 }
 829
 830 static int fd_init_prot(struct se_device *dev)
 831 {
 832         struct fd_dev *fd_dev = FD_DEV(dev);
 833         struct file *prot_file, *file = fd_dev->fd_file;
 834         struct inode *inode;
 835         int ret, flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
 836         char buf[FD_MAX_DEV_PROT_NAME];
 837
 838         if (!file) {
 839                 pr_err("Unable to locate fd_dev->fd_file\n");
 840                 return -ENODEV;
 841         }
 842
 843         inode = file->f_mapping->host;
 844         if (S_ISBLK(inode->i_mode)) {
 845                 pr_err("FILEIO Protection emulation only supported on"
 846                        " !S_ISBLK\n");
 847                 return -ENOSYS;
 848         }
 849
 850         if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE)
 851                 flags &= ~O_DSYNC;
 852
 853         snprintf(buf, FD_MAX_DEV_PROT_NAME, "%s.protection",
 854                  fd_dev->fd_dev_name);
 855
 856         prot_file = filp_open(buf, flags, 0600);
 857         if (IS_ERR(prot_file)) {
 858                 pr_err("filp_open(%s) failed\n", buf);
 859                 ret = PTR_ERR(prot_file);
 860                 return ret;
 861         }
 862         fd_dev->fd_prot_file = prot_file;
 863
 864         return 0;
 865 }
 866
 867 static int fd_format_prot(struct se_device *dev)
 868 {
 869         unsigned char *buf;
 870         int unit_size = FDBD_FORMAT_UNIT_SIZE * dev->dev_attrib.block_size;
 871         int ret;
 872
 873         if (!dev->dev_attrib.pi_prot_type) {
 874                 pr_err("Unable to format_prot while pi_prot_type == 0\n");
 875                 return -ENODEV;
 876         }
 877
 878         buf = vzalloc(unit_size);
 879         if (!buf) {
 880                 pr_err("Unable to allocate FILEIO prot buf\n");
 881                 return -ENOMEM;
 882         }
 883
 884         pr_debug("Using FILEIO prot_length: %llu\n",
 885                  (unsigned long long)(dev->transport->get_blocks(dev) + 1) *
 886                                         dev->prot_length);
 887
 888         ret = fd_do_prot_fill(dev, 0, dev->transport->get_blocks(dev) + 1,
 889                               buf, unit_size);
 890         vfree(buf);
 891         return ret;
 892 }
 893
 894 static void fd_free_prot(struct se_device *dev)
 895 {
 896         struct fd_dev *fd_dev = FD_DEV(dev);
 897
 898         if (!fd_dev->fd_prot_file)
 899                 return;
 900
 901         filp_close(fd_dev->fd_prot_file, NULL);
 902         fd_dev->fd_prot_file = NULL;
 903 }
 904
 905 static struct sbc_ops fd_sbc_ops = {
 906         .execute_rw             = fd_execute_rw,
 907         .execute_sync_cache     = fd_execute_sync_cache,
 908         .execute_write_same     = fd_execute_write_same,
 909         .execute_unmap          = fd_execute_unmap,
 910 };
 911
 912 static sense_reason_t
 913 fd_parse_cdb(struct se_cmd *cmd)
 914 {
 915         return sbc_parse_cdb(cmd, &fd_sbc_ops);
 916 }
 917
 918 static const struct target_backend_ops fileio_ops = {
 919         .name                   = "fileio",
 920         .inquiry_prod           = "FILEIO",
 921         .inquiry_rev            = FD_VERSION,
 922         .owner                  = THIS_MODULE,
 923         .attach_hba             = fd_attach_hba,
 924         .detach_hba             = fd_detach_hba,
 925         .alloc_device           = fd_alloc_device,
 926         .configure_device       = fd_configure_device,
 927         .destroy_device         = fd_destroy_device,
 928         .free_device            = fd_free_device,
 929         .configure_unmap        = fd_configure_unmap,
 930         .parse_cdb              = fd_parse_cdb,
 931         .set_configfs_dev_params = fd_set_configfs_dev_params,
 932         .show_configfs_dev_params = fd_show_configfs_dev_params,
 933         .get_device_type        = sbc_get_device_type,
 934         .get_blocks             = fd_get_blocks,
 935         .init_prot              = fd_init_prot,
 936         .format_prot            = fd_format_prot,
 937         .free_prot              = fd_free_prot,
 938         .tb_dev_attrib_attrs    = sbc_attrib_attrs,
 939 };
 940
 941 static int __init fileio_module_init(void)
 942 {
 943         return transport_backend_register(&fileio_ops);
 944 }
 945
 946 static void __exit fileio_module_exit(void)
 947 {
 948         target_backend_unregister(&fileio_ops);
 949 }
 950
 951 MODULE_DESCRIPTION("TCM FILEIO subsystem plugin");
 952 MODULE_AUTHOR("[email protected]");
 953 MODULE_LICENSE("GPL");
 954
 955 module_init(fileio_module_init);
 956 module_exit(fileio_module_exit);