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 <scsi/scsi_proto.h>
  24 #include <asm/unaligned.h>
  25
  26 #include <target/target_core_base.h>
  27 #include <target/target_core_backend.h>
  28
  29 #include "target_core_file.h"
  30
  31 static inline struct fd_dev *FD_DEV(struct se_device *dev)
  32 {
  33         return container_of(dev, struct fd_dev, dev);
  34 }
  35
  36 static int fd_attach_hba(struct se_hba *hba, u32 host_id)
  37 {
  38         struct fd_host *fd_host;
  39
  40         fd_host = kzalloc(sizeof(struct fd_host), GFP_KERNEL);
  41         if (!fd_host) {
  42                 pr_err("Unable to allocate memory for struct fd_host\n");
  43                 return -ENOMEM;
  44         }
  45
  46         fd_host->fd_host_id = host_id;
  47
  48         hba->hba_ptr = fd_host;
  49
  50         pr_debug("CORE_HBA[%d] - TCM FILEIO HBA Driver %s on Generic"
  51                 " Target Core Stack %s\n", hba->hba_id, FD_VERSION,
  52                 TARGET_CORE_VERSION);
  53         pr_debug("CORE_HBA[%d] - Attached FILEIO HBA: %u to Generic\n",
  54                 hba->hba_id, fd_host->fd_host_id);
  55
  56         return 0;
  57 }
  58
  59 static void fd_detach_hba(struct se_hba *hba)
  60 {
  61         struct fd_host *fd_host = hba->hba_ptr;
  62
  63         pr_debug("CORE_HBA[%d] - Detached FILEIO HBA: %u from Generic"
  64                 " Target Core\n", hba->hba_id, fd_host->fd_host_id);
  65
  66         kfree(fd_host);
  67         hba->hba_ptr = NULL;
  68 }
  69
  70 static struct se_device *fd_alloc_device(struct se_hba *hba, const char *name)
  71 {
  72         struct fd_dev *fd_dev;
  73         struct fd_host *fd_host = hba->hba_ptr;
  74
  75         fd_dev = kzalloc(sizeof(struct fd_dev), GFP_KERNEL);
  76         if (!fd_dev) {
  77                 pr_err("Unable to allocate memory for struct fd_dev\n");
  78                 return NULL;
  79         }
  80
  81         fd_dev->fd_host = fd_host;
  82
  83         pr_debug("FILEIO: Allocated fd_dev for %p\n", name);
  84
  85         return &fd_dev->dev;
  86 }
  87
  88 static int fd_configure_device(struct se_device *dev)
  89 {
  90         struct fd_dev *fd_dev = FD_DEV(dev);
  91         struct fd_host *fd_host = dev->se_hba->hba_ptr;
  92         struct file *file;
  93         struct inode *inode = NULL;
  94         int flags, ret = -EINVAL;
  95
  96         if (!(fd_dev->fbd_flags & FBDF_HAS_PATH)) {
  97                 pr_err("Missing fd_dev_name=\n");
  98                 return -EINVAL;
  99         }
 100
 101         /*
 102          * Use O_DSYNC by default instead of O_SYNC to forgo syncing
 103          * of pure timestamp updates.
 104          */
 105         flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
 106
 107         /*
 108          * Optionally allow fd_buffered_io=1 to be enabled for people
 109          * who want use the fs buffer cache as an WriteCache mechanism.
 110          *
 111          * This means that in event of a hard failure, there is a risk
 112          * of silent data-loss if the SCSI client has *not* performed a
 113          * forced unit access (FUA) write, or issued SYNCHRONIZE_CACHE
 114          * to write-out the entire device cache.
 115          */
 116         if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
 117                 pr_debug("FILEIO: Disabling O_DSYNC, using buffered FILEIO\n");
 118                 flags &= ~O_DSYNC;
 119         }
 120
 121         file = filp_open(fd_dev->fd_dev_name, flags, 0600);
 122         if (IS_ERR(file)) {
 123                 pr_err("filp_open(%s) failed\n", fd_dev->fd_dev_name);
 124                 ret = PTR_ERR(file);
 125                 goto fail;
 126         }
 127         fd_dev->fd_file = file;
 128         /*
 129          * If using a block backend with this struct file, we extract
 130          * fd_dev->fd_[block,dev]_size from struct block_device.
 131          *
 132          * Otherwise, we use the passed fd_size= from configfs
 133          */
 134         inode = file->f_mapping->host;
 135         if (S_ISBLK(inode->i_mode)) {
 136                 struct request_queue *q = bdev_get_queue(I_BDEV(inode));
 137                 unsigned long long dev_size;
 138
 139                 fd_dev->fd_block_size = bdev_logical_block_size(I_BDEV(inode));
 140                 /*
 141                  * Determine the number of bytes from i_size_read() minus
 142                  * one (1) logical sector from underlying struct block_device
 143                  */
 144                 dev_size = (i_size_read(file->f_mapping->host) -
 145                                        fd_dev->fd_block_size);
 146
 147                 pr_debug("FILEIO: Using size: %llu bytes from struct"
 148                         " block_device blocks: %llu logical_block_size: %d\n",
 149                         dev_size, div_u64(dev_size, fd_dev->fd_block_size),
 150                         fd_dev->fd_block_size);
 151
 152                 if (target_configure_unmap_from_queue(&dev->dev_attrib, q))
 153                         pr_debug("IFILE: BLOCK Discard support available,"
 154                                  " disabled by default\n");
 155                 /*
 156                  * Enable write same emulation for IBLOCK and use 0xFFFF as
 157                  * the smaller WRITE_SAME(10) only has a two-byte block count.
 158                  */
 159                 dev->dev_attrib.max_write_same_len = 0xFFFF;
 160
 161                 if (blk_queue_nonrot(q))
 162                         dev->dev_attrib.is_nonrot = 1;
 163         } else {
 164                 if (!(fd_dev->fbd_flags & FBDF_HAS_SIZE)) {
 165                         pr_err("FILEIO: Missing fd_dev_size="
 166                                 " parameter, and no backing struct"
 167                                 " block_device\n");
 168                         goto fail;
 169                 }
 170
 171                 fd_dev->fd_block_size = FD_BLOCKSIZE;
 172                 /*
 173                  * Limit UNMAP emulation to 8k Number of LBAs (NoLB)
 174                  */
 175                 dev->dev_attrib.max_unmap_lba_count = 0x2000;
 176                 /*
 177                  * Currently hardcoded to 1 in Linux/SCSI code..
 178                  */
 179                 dev->dev_attrib.max_unmap_block_desc_count = 1;
 180                 dev->dev_attrib.unmap_granularity = 1;
 181                 dev->dev_attrib.unmap_granularity_alignment = 0;
 182
 183                 /*
 184                  * Limit WRITE_SAME w/ UNMAP=0 emulation to 8k Number of LBAs (NoLB)
 185                  * based upon struct iovec limit for vfs_writev()
 186                  */
 187                 dev->dev_attrib.max_write_same_len = 0x1000;
 188         }
 189
 190         dev->dev_attrib.hw_block_size = fd_dev->fd_block_size;
 191         dev->dev_attrib.max_bytes_per_io = FD_MAX_BYTES;
 192         dev->dev_attrib.hw_max_sectors = FD_MAX_BYTES / fd_dev->fd_block_size;
 193         dev->dev_attrib.hw_queue_depth = FD_MAX_DEVICE_QUEUE_DEPTH;
 194
 195         if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
 196                 pr_debug("FILEIO: Forcing setting of emulate_write_cache=1"
 197                         " with FDBD_HAS_BUFFERED_IO_WCE\n");
 198                 dev->dev_attrib.emulate_write_cache = 1;
 199         }
 200
 201         fd_dev->fd_dev_id = fd_host->fd_host_dev_id_count++;
 202         fd_dev->fd_queue_depth = dev->queue_depth;
 203
 204         pr_debug("CORE_FILE[%u] - Added TCM FILEIO Device ID: %u at %s,"
 205                 " %llu total bytes\n", fd_host->fd_host_id, fd_dev->fd_dev_id,
 206                         fd_dev->fd_dev_name, fd_dev->fd_dev_size);
 207
 208         return 0;
 209 fail:
 210         if (fd_dev->fd_file) {
 211                 filp_close(fd_dev->fd_file, NULL);
 212                 fd_dev->fd_file = NULL;
 213         }
 214         return ret;
 215 }
 216
 217 static void fd_dev_call_rcu(struct rcu_head *p)
 218 {
 219         struct se_device *dev = container_of(p, struct se_device, rcu_head);
 220         struct fd_dev *fd_dev = FD_DEV(dev);
 221
 222         kfree(fd_dev);
 223 }
 224
 225 static void fd_free_device(struct se_device *dev)
 226 {
 227         call_rcu(&dev->rcu_head, fd_dev_call_rcu);
 228 }
 229
 230 static void fd_destroy_device(struct se_device *dev)
 231 {
 232         struct fd_dev *fd_dev = FD_DEV(dev);
 233
 234         if (fd_dev->fd_file) {
 235                 filp_close(fd_dev->fd_file, NULL);
 236                 fd_dev->fd_file = NULL;
 237         }
 238 }
 239
 240 struct target_core_file_cmd {
 241         unsigned long   len;
 242         struct se_cmd   *cmd;
 243         struct kiocb    iocb;
 244         struct bio_vec  bvecs[];
 245 };
 246
 247 static void cmd_rw_aio_complete(struct kiocb *iocb, long ret, long ret2)
 248 {
 249         struct target_core_file_cmd *cmd;
 250
 251         cmd = container_of(iocb, struct target_core_file_cmd, iocb);
 252
 253         if (ret != cmd->len)
 254                 target_complete_cmd(cmd->cmd, SAM_STAT_CHECK_CONDITION);
 255         else
 256                 target_complete_cmd(cmd->cmd, SAM_STAT_GOOD);
 257
 258         kfree(cmd);
 259 }
 260
 261 static sense_reason_t
 262 fd_execute_rw_aio(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 263               enum dma_data_direction data_direction)
 264 {
 265         int is_write = !(data_direction == DMA_FROM_DEVICE);
 266         struct se_device *dev = cmd->se_dev;
 267         struct fd_dev *fd_dev = FD_DEV(dev);
 268         struct file *file = fd_dev->fd_file;
 269         struct target_core_file_cmd *aio_cmd;
 270         struct iov_iter iter;
 271         struct scatterlist *sg;
 272         ssize_t len = 0;
 273         int ret = 0, i;
 274
 275         aio_cmd = kmalloc(struct_size(aio_cmd, bvecs, sgl_nents), GFP_KERNEL);
 276         if (!aio_cmd)
 277                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 278
 279         for_each_sg(sgl, sg, sgl_nents, i) {
 280                 aio_cmd->bvecs[i].bv_page = sg_page(sg);
 281                 aio_cmd->bvecs[i].bv_len = sg->length;
 282                 aio_cmd->bvecs[i].bv_offset = sg->offset;
 283
 284                 len += sg->length;
 285         }
 286
 287         iov_iter_bvec(&iter, is_write, aio_cmd->bvecs, sgl_nents, len);
 288
 289         aio_cmd->cmd = cmd;
 290         aio_cmd->len = len;
 291         aio_cmd->iocb.ki_pos = cmd->t_task_lba * dev->dev_attrib.block_size;
 292         aio_cmd->iocb.ki_filp = file;
 293         aio_cmd->iocb.ki_complete = cmd_rw_aio_complete;
 294         aio_cmd->iocb.ki_flags = IOCB_DIRECT;
 295
 296         if (is_write && (cmd->se_cmd_flags & SCF_FUA))
 297                 aio_cmd->iocb.ki_flags |= IOCB_DSYNC;
 298
 299         if (is_write)
 300                 ret = call_write_iter(file, &aio_cmd->iocb, &iter);
 301         else
 302                 ret = call_read_iter(file, &aio_cmd->iocb, &iter);
 303
 304         if (ret != -EIOCBQUEUED)
 305                 cmd_rw_aio_complete(&aio_cmd->iocb, ret, 0);
 306
 307         return 0;
 308 }
 309
 310 static int fd_do_rw(struct se_cmd *cmd, struct file *fd,
 311                     u32 block_size, struct scatterlist *sgl,
 312                     u32 sgl_nents, u32 data_length, int is_write)
 313 {
 314         struct scatterlist *sg;
 315         struct iov_iter iter;
 316         struct bio_vec *bvec;
 317         ssize_t len = 0;
 318         loff_t pos = (cmd->t_task_lba * block_size);
 319         int ret = 0, i;
 320
 321         bvec = kcalloc(sgl_nents, sizeof(struct bio_vec), GFP_KERNEL);
 322         if (!bvec) {
 323                 pr_err("Unable to allocate fd_do_readv iov[]\n");
 324                 return -ENOMEM;
 325         }
 326
 327         for_each_sg(sgl, sg, sgl_nents, i) {
 328                 bvec[i].bv_page = sg_page(sg);
 329                 bvec[i].bv_len = sg->length;
 330                 bvec[i].bv_offset = sg->offset;
 331
 332                 len += sg->length;
 333         }
 334
 335         iov_iter_bvec(&iter, READ, bvec, sgl_nents, len);
 336         if (is_write)
 337                 ret = vfs_iter_write(fd, &iter, &pos, 0);
 338         else
 339                 ret = vfs_iter_read(fd, &iter, &pos, 0);
 340
 341         if (is_write) {
 342                 if (ret < 0 || ret != data_length) {
 343                         pr_err("%s() write returned %d\n", __func__, ret);
 344                         if (ret >= 0)
 345                                 ret = -EINVAL;
 346                 }
 347         } else {
 348                 /*
 349                  * Return zeros and GOOD status even if the READ did not return
 350                  * the expected virt_size for struct file w/o a backing struct
 351                  * block_device.
 352                  */
 353                 if (S_ISBLK(file_inode(fd)->i_mode)) {
 354                         if (ret < 0 || ret != data_length) {
 355                                 pr_err("%s() returned %d, expecting %u for "
 356                                                 "S_ISBLK\n", __func__, ret,
 357                                                 data_length);
 358                                 if (ret >= 0)
 359                                         ret = -EINVAL;
 360                         }
 361                 } else {
 362                         if (ret < 0) {
 363                                 pr_err("%s() returned %d for non S_ISBLK\n",
 364                                                 __func__, ret);
 365                         } else if (ret != data_length) {
 366                                 /*
 367                                  * Short read case:
 368                                  * Probably some one truncate file under us.
 369                                  * We must explicitly zero sg-pages to prevent
 370                                  * expose uninizialized pages to userspace.
 371                                  */
 372                                 if (ret < data_length)
 373                                         ret += iov_iter_zero(data_length - ret, &iter);
 374                                 else
 375                                         ret = -EINVAL;
 376                         }
 377                 }
 378         }
 379         kfree(bvec);
 380         return ret;
 381 }
 382
 383 static sense_reason_t
 384 fd_execute_sync_cache(struct se_cmd *cmd)
 385 {
 386         struct se_device *dev = cmd->se_dev;
 387         struct fd_dev *fd_dev = FD_DEV(dev);
 388         int immed = (cmd->t_task_cdb[1] & 0x2);
 389         loff_t start, end;
 390         int ret;
 391
 392         /*
 393          * If the Immediate bit is set, queue up the GOOD response
 394          * for this SYNCHRONIZE_CACHE op
 395          */
 396         if (immed)
 397                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 398
 399         /*
 400          * Determine if we will be flushing the entire device.
 401          */
 402         if (cmd->t_task_lba == 0 && cmd->data_length == 0) {
 403                 start = 0;
 404                 end = LLONG_MAX;
 405         } else {
 406                 start = cmd->t_task_lba * dev->dev_attrib.block_size;
 407                 if (cmd->data_length)
 408                         end = start + cmd->data_length - 1;
 409                 else
 410                         end = LLONG_MAX;
 411         }
 412
 413         ret = vfs_fsync_range(fd_dev->fd_file, start, end, 1);
 414         if (ret != 0)
 415                 pr_err("FILEIO: vfs_fsync_range() failed: %d\n", ret);
 416
 417         if (immed)
 418                 return 0;
 419
 420         if (ret)
 421                 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
 422         else
 423                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 424
 425         return 0;
 426 }
 427
 428 static sense_reason_t
 429 fd_execute_write_same(struct se_cmd *cmd)
 430 {
 431         struct se_device *se_dev = cmd->se_dev;
 432         struct fd_dev *fd_dev = FD_DEV(se_dev);
 433         loff_t pos = cmd->t_task_lba * se_dev->dev_attrib.block_size;
 434         sector_t nolb = sbc_get_write_same_sectors(cmd);
 435         struct iov_iter iter;
 436         struct bio_vec *bvec;
 437         unsigned int len = 0, i;
 438         ssize_t ret;
 439
 440         if (!nolb) {
 441                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 442                 return 0;
 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 > 1 ||
 451             cmd->t_data_sg[0].length != cmd->se_dev->dev_attrib.block_size) {
 452                 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
 453                         " block_size: %u\n",
 454                         cmd->t_data_nents,
 455                         cmd->t_data_sg[0].length,
 456                         cmd->se_dev->dev_attrib.block_size);
 457                 return TCM_INVALID_CDB_FIELD;
 458         }
 459
 460         bvec = kcalloc(nolb, sizeof(struct bio_vec), GFP_KERNEL);
 461         if (!bvec)
 462                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 463
 464         for (i = 0; i < nolb; i++) {
 465                 bvec[i].bv_page = sg_page(&cmd->t_data_sg[0]);
 466                 bvec[i].bv_len = cmd->t_data_sg[0].length;
 467                 bvec[i].bv_offset = cmd->t_data_sg[0].offset;
 468
 469                 len += se_dev->dev_attrib.block_size;
 470         }
 471
 472         iov_iter_bvec(&iter, READ, bvec, nolb, len);
 473         ret = vfs_iter_write(fd_dev->fd_file, &iter, &pos, 0);
 474
 475         kfree(bvec);
 476         if (ret < 0 || ret != len) {
 477                 pr_err("vfs_iter_write() returned %zd for write same\n", ret);
 478                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 479         }
 480
 481         target_complete_cmd(cmd, SAM_STAT_GOOD);
 482         return 0;
 483 }
 484
 485 static int
 486 fd_do_prot_fill(struct se_device *se_dev, sector_t lba, sector_t nolb,
 487                 void *buf, size_t bufsize)
 488 {
 489         struct fd_dev *fd_dev = FD_DEV(se_dev);
 490         struct file *prot_fd = fd_dev->fd_prot_file;
 491         sector_t prot_length, prot;
 492         loff_t pos = lba * se_dev->prot_length;
 493
 494         if (!prot_fd) {
 495                 pr_err("Unable to locate fd_dev->fd_prot_file\n");
 496                 return -ENODEV;
 497         }
 498
 499         prot_length = nolb * se_dev->prot_length;
 500
 501         memset(buf, 0xff, bufsize);
 502         for (prot = 0; prot < prot_length;) {
 503                 sector_t len = min_t(sector_t, bufsize, prot_length - prot);
 504                 ssize_t ret = kernel_write(prot_fd, buf, len, &pos);
 505
 506                 if (ret != len) {
 507                         pr_err("vfs_write to prot file failed: %zd\n", ret);
 508                         return ret < 0 ? ret : -ENODEV;
 509                 }
 510                 prot += ret;
 511         }
 512
 513         return 0;
 514 }
 515
 516 static int
 517 fd_do_prot_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
 518 {
 519         void *buf;
 520         int rc;
 521
 522         buf = (void *)__get_free_page(GFP_KERNEL);
 523         if (!buf) {
 524                 pr_err("Unable to allocate FILEIO prot buf\n");
 525                 return -ENOMEM;
 526         }
 527
 528         rc = fd_do_prot_fill(cmd->se_dev, lba, nolb, buf, PAGE_SIZE);
 529
 530         free_page((unsigned long)buf);
 531
 532         return rc;
 533 }
 534
 535 static sense_reason_t
 536 fd_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
 537 {
 538         struct file *file = FD_DEV(cmd->se_dev)->fd_file;
 539         struct inode *inode = file->f_mapping->host;
 540         int ret;
 541
 542         if (!nolb) {
 543                 return 0;
 544         }
 545
 546         if (cmd->se_dev->dev_attrib.pi_prot_type) {
 547                 ret = fd_do_prot_unmap(cmd, lba, nolb);
 548                 if (ret)
 549                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 550         }
 551
 552         if (S_ISBLK(inode->i_mode)) {
 553                 /* The backend is block device, use discard */
 554                 struct block_device *bdev = I_BDEV(inode);
 555                 struct se_device *dev = cmd->se_dev;
 556
 557                 ret = blkdev_issue_discard(bdev,
 558                                            target_to_linux_sector(dev, lba),
 559                                            target_to_linux_sector(dev,  nolb),
 560                                            GFP_KERNEL, 0);
 561                 if (ret < 0) {
 562                         pr_warn("FILEIO: blkdev_issue_discard() failed: %d\n",
 563                                 ret);
 564                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 565                 }
 566         } else {
 567                 /* The backend is normal file, use fallocate */
 568                 struct se_device *se_dev = cmd->se_dev;
 569                 loff_t pos = lba * se_dev->dev_attrib.block_size;
 570                 unsigned int len = nolb * se_dev->dev_attrib.block_size;
 571                 int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
 572
 573                 if (!file->f_op->fallocate)
 574                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 575
 576                 ret = file->f_op->fallocate(file, mode, pos, len);
 577                 if (ret < 0) {
 578                         pr_warn("FILEIO: fallocate() failed: %d\n", ret);
 579                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 580                 }
 581         }
 582
 583         return 0;
 584 }
 585
 586 static sense_reason_t
 587 fd_execute_rw_buffered(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 588               enum dma_data_direction data_direction)
 589 {
 590         struct se_device *dev = cmd->se_dev;
 591         struct fd_dev *fd_dev = FD_DEV(dev);
 592         struct file *file = fd_dev->fd_file;
 593         struct file *pfile = fd_dev->fd_prot_file;
 594         sense_reason_t rc;
 595         int ret = 0;
 596         /*
 597          * Call vectorized fileio functions to map struct scatterlist
 598          * physical memory addresses to struct iovec virtual memory.
 599          */
 600         if (data_direction == DMA_FROM_DEVICE) {
 601                 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 602                         ret = fd_do_rw(cmd, pfile, dev->prot_length,
 603                                        cmd->t_prot_sg, cmd->t_prot_nents,
 604                                        cmd->prot_length, 0);
 605                         if (ret < 0)
 606                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 607                 }
 608
 609                 ret = fd_do_rw(cmd, file, dev->dev_attrib.block_size,
 610                                sgl, sgl_nents, cmd->data_length, 0);
 611
 612                 if (ret > 0 && cmd->prot_type && dev->dev_attrib.pi_prot_type &&
 613                     dev->dev_attrib.pi_prot_verify) {
 614                         u32 sectors = cmd->data_length >>
 615                                         ilog2(dev->dev_attrib.block_size);
 616
 617                         rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors,
 618                                             0, cmd->t_prot_sg, 0);
 619                         if (rc)
 620                                 return rc;
 621                 }
 622         } else {
 623                 if (cmd->prot_type && dev->dev_attrib.pi_prot_type &&
 624                     dev->dev_attrib.pi_prot_verify) {
 625                         u32 sectors = cmd->data_length >>
 626                                         ilog2(dev->dev_attrib.block_size);
 627
 628                         rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors,
 629                                             0, cmd->t_prot_sg, 0);
 630                         if (rc)
 631                                 return rc;
 632                 }
 633
 634                 ret = fd_do_rw(cmd, file, dev->dev_attrib.block_size,
 635                                sgl, sgl_nents, cmd->data_length, 1);
 636                 /*
 637                  * Perform implicit vfs_fsync_range() for fd_do_writev() ops
 638                  * for SCSI WRITEs with Forced Unit Access (FUA) set.
 639                  * Allow this to happen independent of WCE=0 setting.
 640                  */
 641                 if (ret > 0 && (cmd->se_cmd_flags & SCF_FUA)) {
 642                         loff_t start = cmd->t_task_lba *
 643                                 dev->dev_attrib.block_size;
 644                         loff_t end;
 645
 646                         if (cmd->data_length)
 647                                 end = start + cmd->data_length - 1;
 648                         else
 649                                 end = LLONG_MAX;
 650
 651                         vfs_fsync_range(fd_dev->fd_file, start, end, 1);
 652                 }
 653
 654                 if (ret > 0 && cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 655                         ret = fd_do_rw(cmd, pfile, dev->prot_length,
 656                                        cmd->t_prot_sg, cmd->t_prot_nents,
 657                                        cmd->prot_length, 1);
 658                         if (ret < 0)
 659                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 660                 }
 661         }
 662
 663         if (ret < 0)
 664                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 665
 666         target_complete_cmd(cmd, SAM_STAT_GOOD);
 667         return 0;
 668 }
 669
 670 static sense_reason_t
 671 fd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 672               enum dma_data_direction data_direction)
 673 {
 674         struct se_device *dev = cmd->se_dev;
 675         struct fd_dev *fd_dev = FD_DEV(dev);
 676
 677         /*
 678          * We are currently limited by the number of iovecs (2048) per
 679          * single vfs_[writev,readv] call.
 680          */
 681         if (cmd->data_length > FD_MAX_BYTES) {
 682                 pr_err("FILEIO: Not able to process I/O of %u bytes due to"
 683                        "FD_MAX_BYTES: %u iovec count limitation\n",
 684                         cmd->data_length, FD_MAX_BYTES);
 685                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 686         }
 687
 688         if (fd_dev->fbd_flags & FDBD_HAS_ASYNC_IO)
 689                 return fd_execute_rw_aio(cmd, sgl, sgl_nents, data_direction);
 690         return fd_execute_rw_buffered(cmd, sgl, sgl_nents, data_direction);
 691 }
 692
 693 enum {
 694         Opt_fd_dev_name, Opt_fd_dev_size, Opt_fd_buffered_io,
 695         Opt_fd_async_io, Opt_err
 696 };
 697
 698 static match_table_t tokens = {
 699         {Opt_fd_dev_name, "fd_dev_name=%s"},
 700         {Opt_fd_dev_size, "fd_dev_size=%s"},
 701         {Opt_fd_buffered_io, "fd_buffered_io=%d"},
 702         {Opt_fd_async_io, "fd_async_io=%d"},
 703         {Opt_err, NULL}
 704 };
 705
 706 static ssize_t fd_set_configfs_dev_params(struct se_device *dev,
 707                 const char *page, ssize_t count)
 708 {
 709         struct fd_dev *fd_dev = FD_DEV(dev);
 710         char *orig, *ptr, *arg_p, *opts;
 711         substring_t args[MAX_OPT_ARGS];
 712         int ret = 0, arg, token;
 713
 714         opts = kstrdup(page, GFP_KERNEL);
 715         if (!opts)
 716                 return -ENOMEM;
 717
 718         orig = opts;
 719
 720         while ((ptr = strsep(&opts, ",\n")) != NULL) {
 721                 if (!*ptr)
 722                         continue;
 723
 724                 token = match_token(ptr, tokens, args);
 725                 switch (token) {
 726                 case Opt_fd_dev_name:
 727                         if (match_strlcpy(fd_dev->fd_dev_name, &args[0],
 728                                 FD_MAX_DEV_NAME) == 0) {
 729                                 ret = -EINVAL;
 730                                 break;
 731                         }
 732                         pr_debug("FILEIO: Referencing Path: %s\n",
 733                                         fd_dev->fd_dev_name);
 734                         fd_dev->fbd_flags |= FBDF_HAS_PATH;
 735                         break;
 736                 case Opt_fd_dev_size:
 737                         arg_p = match_strdup(&args[0]);
 738                         if (!arg_p) {
 739                                 ret = -ENOMEM;
 740                                 break;
 741                         }
 742                         ret = kstrtoull(arg_p, 0, &fd_dev->fd_dev_size);
 743                         kfree(arg_p);
 744                         if (ret < 0) {
 745                                 pr_err("kstrtoull() failed for"
 746                                                 " fd_dev_size=\n");
 747                                 goto out;
 748                         }
 749                         pr_debug("FILEIO: Referencing Size: %llu"
 750                                         " bytes\n", fd_dev->fd_dev_size);
 751                         fd_dev->fbd_flags |= FBDF_HAS_SIZE;
 752                         break;
 753                 case Opt_fd_buffered_io:
 754                         ret = match_int(args, &arg);
 755                         if (ret)
 756                                 goto out;
 757                         if (arg != 1) {
 758                                 pr_err("bogus fd_buffered_io=%d value\n", arg);
 759                                 ret = -EINVAL;
 760                                 goto out;
 761                         }
 762
 763                         pr_debug("FILEIO: Using buffered I/O"
 764                                 " operations for struct fd_dev\n");
 765
 766                         fd_dev->fbd_flags |= FDBD_HAS_BUFFERED_IO_WCE;
 767                         break;
 768                 case Opt_fd_async_io:
 769                         ret = match_int(args, &arg);
 770                         if (ret)
 771                                 goto out;
 772                         if (arg != 1) {
 773                                 pr_err("bogus fd_async_io=%d value\n", arg);
 774                                 ret = -EINVAL;
 775                                 goto out;
 776                         }
 777
 778                         pr_debug("FILEIO: Using async I/O"
 779                                 " operations for struct fd_dev\n");
 780
 781                         fd_dev->fbd_flags |= FDBD_HAS_ASYNC_IO;
 782                         break;
 783                 default:
 784                         break;
 785                 }
 786         }
 787
 788 out:
 789         kfree(orig);
 790         return (!ret) ? count : ret;
 791 }
 792
 793 static ssize_t fd_show_configfs_dev_params(struct se_device *dev, char *b)
 794 {
 795         struct fd_dev *fd_dev = FD_DEV(dev);
 796         ssize_t bl = 0;
 797
 798         bl = sprintf(b + bl, "TCM FILEIO ID: %u", fd_dev->fd_dev_id);
 799         bl += sprintf(b + bl, "        File: %s  Size: %llu  Mode: %s Async: %d\n",
 800                 fd_dev->fd_dev_name, fd_dev->fd_dev_size,
 801                 (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) ?
 802                 "Buffered-WCE" : "O_DSYNC",
 803                 !!(fd_dev->fbd_flags & FDBD_HAS_ASYNC_IO));
 804         return bl;
 805 }
 806
 807 static sector_t fd_get_blocks(struct se_device *dev)
 808 {
 809         struct fd_dev *fd_dev = FD_DEV(dev);
 810         struct file *f = fd_dev->fd_file;
 811         struct inode *i = f->f_mapping->host;
 812         unsigned long long dev_size;
 813         /*
 814          * When using a file that references an underlying struct block_device,
 815          * ensure dev_size is always based on the current inode size in order
 816          * to handle underlying block_device resize operations.
 817          */
 818         if (S_ISBLK(i->i_mode))
 819                 dev_size = i_size_read(i);
 820         else
 821                 dev_size = fd_dev->fd_dev_size;
 822
 823         return div_u64(dev_size - dev->dev_attrib.block_size,
 824                        dev->dev_attrib.block_size);
 825 }
 826
 827 static int fd_init_prot(struct se_device *dev)
 828 {
 829         struct fd_dev *fd_dev = FD_DEV(dev);
 830         struct file *prot_file, *file = fd_dev->fd_file;
 831         struct inode *inode;
 832         int ret, flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
 833         char buf[FD_MAX_DEV_PROT_NAME];
 834
 835         if (!file) {
 836                 pr_err("Unable to locate fd_dev->fd_file\n");
 837                 return -ENODEV;
 838         }
 839
 840         inode = file->f_mapping->host;
 841         if (S_ISBLK(inode->i_mode)) {
 842                 pr_err("FILEIO Protection emulation only supported on"
 843                        " !S_ISBLK\n");
 844                 return -ENOSYS;
 845         }
 846
 847         if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE)
 848                 flags &= ~O_DSYNC;
 849
 850         snprintf(buf, FD_MAX_DEV_PROT_NAME, "%s.protection",
 851                  fd_dev->fd_dev_name);
 852
 853         prot_file = filp_open(buf, flags, 0600);
 854         if (IS_ERR(prot_file)) {
 855                 pr_err("filp_open(%s) failed\n", buf);
 856                 ret = PTR_ERR(prot_file);
 857                 return ret;
 858         }
 859         fd_dev->fd_prot_file = prot_file;
 860
 861         return 0;
 862 }
 863
 864 static int fd_format_prot(struct se_device *dev)
 865 {
 866         unsigned char *buf;
 867         int unit_size = FDBD_FORMAT_UNIT_SIZE * dev->dev_attrib.block_size;
 868         int ret;
 869
 870         if (!dev->dev_attrib.pi_prot_type) {
 871                 pr_err("Unable to format_prot while pi_prot_type == 0\n");
 872                 return -ENODEV;
 873         }
 874
 875         buf = vzalloc(unit_size);
 876         if (!buf) {
 877                 pr_err("Unable to allocate FILEIO prot buf\n");
 878                 return -ENOMEM;
 879         }
 880
 881         pr_debug("Using FILEIO prot_length: %llu\n",
 882                  (unsigned long long)(dev->transport->get_blocks(dev) + 1) *
 883                                         dev->prot_length);
 884
 885         ret = fd_do_prot_fill(dev, 0, dev->transport->get_blocks(dev) + 1,
 886                               buf, unit_size);
 887         vfree(buf);
 888         return ret;
 889 }
 890
 891 static void fd_free_prot(struct se_device *dev)
 892 {
 893         struct fd_dev *fd_dev = FD_DEV(dev);
 894
 895         if (!fd_dev->fd_prot_file)
 896                 return;
 897
 898         filp_close(fd_dev->fd_prot_file, NULL);
 899         fd_dev->fd_prot_file = NULL;
 900 }
 901
 902 static struct sbc_ops fd_sbc_ops = {
 903         .execute_rw             = fd_execute_rw,
 904         .execute_sync_cache     = fd_execute_sync_cache,
 905         .execute_write_same     = fd_execute_write_same,
 906         .execute_unmap          = fd_execute_unmap,
 907 };
 908
 909 static sense_reason_t
 910 fd_parse_cdb(struct se_cmd *cmd)
 911 {
 912         return sbc_parse_cdb(cmd, &fd_sbc_ops);
 913 }
 914
 915 static const struct target_backend_ops fileio_ops = {
 916         .name                   = "fileio",
 917         .inquiry_prod           = "FILEIO",
 918         .inquiry_rev            = FD_VERSION,
 919         .owner                  = THIS_MODULE,
 920         .attach_hba             = fd_attach_hba,
 921         .detach_hba             = fd_detach_hba,
 922         .alloc_device           = fd_alloc_device,
 923         .configure_device       = fd_configure_device,
 924         .destroy_device         = fd_destroy_device,
 925         .free_device            = fd_free_device,
 926         .parse_cdb              = fd_parse_cdb,
 927         .set_configfs_dev_params = fd_set_configfs_dev_params,
 928         .show_configfs_dev_params = fd_show_configfs_dev_params,
 929         .get_device_type        = sbc_get_device_type,
 930         .get_blocks             = fd_get_blocks,
 931         .init_prot              = fd_init_prot,
 932         .format_prot            = fd_format_prot,
 933         .free_prot              = fd_free_prot,
 934         .tb_dev_attrib_attrs    = sbc_attrib_attrs,
 935 };
 936
 937 static int __init fileio_module_init(void)
 938 {
 939         return transport_backend_register(&fileio_ops);
 940 }
 941
 942 static void __exit fileio_module_exit(void)
 943 {
 944         target_backend_unregister(&fileio_ops);
 945 }
 946
 947 MODULE_DESCRIPTION("TCM FILEIO subsystem plugin");
 948 MODULE_AUTHOR("nab@Linux-iSCSI.org");
 949 MODULE_LICENSE("GPL");
 950
 951 module_init(fileio_module_init);
 952 module_exit(fileio_module_exit);