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.max_bytes_per_io = FD_MAX_BYTES;
 197         dev->dev_attrib.hw_max_sectors = FD_MAX_BYTES / fd_dev->fd_block_size;
 198         dev->dev_attrib.hw_queue_depth = FD_MAX_DEVICE_QUEUE_DEPTH;
 199
 200         if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
 201                 pr_debug("FILEIO: Forcing setting of emulate_write_cache=1"
 202                         " with FDBD_HAS_BUFFERED_IO_WCE\n");
 203                 dev->dev_attrib.emulate_write_cache = 1;
 204         }
 205
 206         fd_dev->fd_dev_id = fd_host->fd_host_dev_id_count++;
 207         fd_dev->fd_queue_depth = dev->queue_depth;
 208
 209         pr_debug("CORE_FILE[%u] - Added TCM FILEIO Device ID: %u at %s,"
 210                 " %llu total bytes\n", fd_host->fd_host_id, fd_dev->fd_dev_id,
 211                         fd_dev->fd_dev_name, fd_dev->fd_dev_size);
 212
 213         return 0;
 214 fail:
 215         if (fd_dev->fd_file) {
 216                 filp_close(fd_dev->fd_file, NULL);
 217                 fd_dev->fd_file = NULL;
 218         }
 219         return ret;
 220 }
 221
 222 static void fd_dev_call_rcu(struct rcu_head *p)
 223 {
 224         struct se_device *dev = container_of(p, struct se_device, rcu_head);
 225         struct fd_dev *fd_dev = FD_DEV(dev);
 226
 227         kfree(fd_dev);
 228 }
 229
 230 static void fd_free_device(struct se_device *dev)
 231 {
 232         call_rcu(&dev->rcu_head, fd_dev_call_rcu);
 233 }
 234
 235 static void fd_destroy_device(struct se_device *dev)
 236 {
 237         struct fd_dev *fd_dev = FD_DEV(dev);
 238
 239         if (fd_dev->fd_file) {
 240                 filp_close(fd_dev->fd_file, NULL);
 241                 fd_dev->fd_file = NULL;
 242         }
 243 }
 244
 245 struct target_core_file_cmd {
 246         unsigned long   len;
 247         struct se_cmd   *cmd;
 248         struct kiocb    iocb;
 249         struct bio_vec  bvecs[];
 250 };
 251
 252 static void cmd_rw_aio_complete(struct kiocb *iocb, long ret)
 253 {
 254         struct target_core_file_cmd *cmd;
 255
 256         cmd = container_of(iocb, struct target_core_file_cmd, iocb);
 257
 258         if (ret != cmd->len)
 259                 target_complete_cmd(cmd->cmd, SAM_STAT_CHECK_CONDITION);
 260         else
 261                 target_complete_cmd(cmd->cmd, SAM_STAT_GOOD);
 262
 263         kfree(cmd);
 264 }
 265
 266 static sense_reason_t
 267 fd_execute_rw_aio(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 268               enum dma_data_direction data_direction)
 269 {
 270         int is_write = !(data_direction == DMA_FROM_DEVICE);
 271         struct se_device *dev = cmd->se_dev;
 272         struct fd_dev *fd_dev = FD_DEV(dev);
 273         struct file *file = fd_dev->fd_file;
 274         struct target_core_file_cmd *aio_cmd;
 275         struct iov_iter iter;
 276         struct scatterlist *sg;
 277         ssize_t len = 0;
 278         int ret = 0, i;
 279
 280         aio_cmd = kmalloc(struct_size(aio_cmd, bvecs, sgl_nents), GFP_KERNEL);
 281         if (!aio_cmd)
 282                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 283
 284         for_each_sg(sgl, sg, sgl_nents, i) {
 285                 aio_cmd->bvecs[i].bv_page = sg_page(sg);
 286                 aio_cmd->bvecs[i].bv_len = sg->length;
 287                 aio_cmd->bvecs[i].bv_offset = sg->offset;
 288
 289                 len += sg->length;
 290         }
 291
 292         iov_iter_bvec(&iter, is_write, aio_cmd->bvecs, sgl_nents, len);
 293
 294         aio_cmd->cmd = cmd;
 295         aio_cmd->len = len;
 296         aio_cmd->iocb.ki_pos = cmd->t_task_lba * dev->dev_attrib.block_size;
 297         aio_cmd->iocb.ki_filp = file;
 298         aio_cmd->iocb.ki_complete = cmd_rw_aio_complete;
 299         aio_cmd->iocb.ki_flags = IOCB_DIRECT;
 300
 301         if (is_write && (cmd->se_cmd_flags & SCF_FUA))
 302                 aio_cmd->iocb.ki_flags |= IOCB_DSYNC;
 303
 304         if (is_write)
 305                 ret = call_write_iter(file, &aio_cmd->iocb, &iter);
 306         else
 307                 ret = call_read_iter(file, &aio_cmd->iocb, &iter);
 308
 309         if (ret != -EIOCBQUEUED)
 310                 cmd_rw_aio_complete(&aio_cmd->iocb, ret);
 311
 312         return 0;
 313 }
 314
 315 static int fd_do_rw(struct se_cmd *cmd, struct file *fd,
 316                     u32 block_size, struct scatterlist *sgl,
 317                     u32 sgl_nents, u32 data_length, int is_write)
 318 {
 319         struct scatterlist *sg;
 320         struct iov_iter iter;
 321         struct bio_vec *bvec;
 322         ssize_t len = 0;
 323         loff_t pos = (cmd->t_task_lba * block_size);
 324         int ret = 0, i;
 325
 326         bvec = kcalloc(sgl_nents, sizeof(struct bio_vec), GFP_KERNEL);
 327         if (!bvec) {
 328                 pr_err("Unable to allocate fd_do_readv iov[]\n");
 329                 return -ENOMEM;
 330         }
 331
 332         for_each_sg(sgl, sg, sgl_nents, i) {
 333                 bvec[i].bv_page = sg_page(sg);
 334                 bvec[i].bv_len = sg->length;
 335                 bvec[i].bv_offset = sg->offset;
 336
 337                 len += sg->length;
 338         }
 339
 340         iov_iter_bvec(&iter, READ, bvec, sgl_nents, len);
 341         if (is_write)
 342                 ret = vfs_iter_write(fd, &iter, &pos, 0);
 343         else
 344                 ret = vfs_iter_read(fd, &iter, &pos, 0);
 345
 346         if (is_write) {
 347                 if (ret < 0 || ret != data_length) {
 348                         pr_err("%s() write returned %d\n", __func__, ret);
 349                         if (ret >= 0)
 350                                 ret = -EINVAL;
 351                 }
 352         } else {
 353                 /*
 354                  * Return zeros and GOOD status even if the READ did not return
 355                  * the expected virt_size for struct file w/o a backing struct
 356                  * block_device.
 357                  */
 358                 if (S_ISBLK(file_inode(fd)->i_mode)) {
 359                         if (ret < 0 || ret != data_length) {
 360                                 pr_err("%s() returned %d, expecting %u for "
 361                                                 "S_ISBLK\n", __func__, ret,
 362                                                 data_length);
 363                                 if (ret >= 0)
 364                                         ret = -EINVAL;
 365                         }
 366                 } else {
 367                         if (ret < 0) {
 368                                 pr_err("%s() returned %d for non S_ISBLK\n",
 369                                                 __func__, ret);
 370                         } else if (ret != data_length) {
 371                                 /*
 372                                  * Short read case:
 373                                  * Probably some one truncate file under us.
 374                                  * We must explicitly zero sg-pages to prevent
 375                                  * expose uninizialized pages to userspace.
 376                                  */
 377                                 if (ret < data_length)
 378                                         ret += iov_iter_zero(data_length - ret, &iter);
 379                                 else
 380                                         ret = -EINVAL;
 381                         }
 382                 }
 383         }
 384         kfree(bvec);
 385         return ret;
 386 }
 387
 388 static sense_reason_t
 389 fd_execute_sync_cache(struct se_cmd *cmd)
 390 {
 391         struct se_device *dev = cmd->se_dev;
 392         struct fd_dev *fd_dev = FD_DEV(dev);
 393         int immed = (cmd->t_task_cdb[1] & 0x2);
 394         loff_t start, end;
 395         int ret;
 396
 397         /*
 398          * If the Immediate bit is set, queue up the GOOD response
 399          * for this SYNCHRONIZE_CACHE op
 400          */
 401         if (immed)
 402                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 403
 404         /*
 405          * Determine if we will be flushing the entire device.
 406          */
 407         if (cmd->t_task_lba == 0 && cmd->data_length == 0) {
 408                 start = 0;
 409                 end = LLONG_MAX;
 410         } else {
 411                 start = cmd->t_task_lba * dev->dev_attrib.block_size;
 412                 if (cmd->data_length)
 413                         end = start + cmd->data_length - 1;
 414                 else
 415                         end = LLONG_MAX;
 416         }
 417
 418         ret = vfs_fsync_range(fd_dev->fd_file, start, end, 1);
 419         if (ret != 0)
 420                 pr_err("FILEIO: vfs_fsync_range() failed: %d\n", ret);
 421
 422         if (immed)
 423                 return 0;
 424
 425         if (ret)
 426                 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
 427         else
 428                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 429
 430         return 0;
 431 }
 432
 433 static sense_reason_t
 434 fd_execute_write_same(struct se_cmd *cmd)
 435 {
 436         struct se_device *se_dev = cmd->se_dev;
 437         struct fd_dev *fd_dev = FD_DEV(se_dev);
 438         loff_t pos = cmd->t_task_lba * se_dev->dev_attrib.block_size;
 439         sector_t nolb = sbc_get_write_same_sectors(cmd);
 440         struct iov_iter iter;
 441         struct bio_vec *bvec;
 442         unsigned int len = 0, i;
 443         ssize_t ret;
 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)
 452                 return TCM_INVALID_CDB_FIELD;
 453
 454         if (cmd->t_data_nents > 1 ||
 455             cmd->t_data_sg[0].length != cmd->se_dev->dev_attrib.block_size) {
 456                 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
 457                         " block_size: %u\n",
 458                         cmd->t_data_nents,
 459                         cmd->t_data_sg[0].length,
 460                         cmd->se_dev->dev_attrib.block_size);
 461                 return TCM_INVALID_CDB_FIELD;
 462         }
 463
 464         bvec = kcalloc(nolb, sizeof(struct bio_vec), GFP_KERNEL);
 465         if (!bvec)
 466                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 467
 468         for (i = 0; i < nolb; i++) {
 469                 bvec[i].bv_page = sg_page(&cmd->t_data_sg[0]);
 470                 bvec[i].bv_len = cmd->t_data_sg[0].length;
 471                 bvec[i].bv_offset = cmd->t_data_sg[0].offset;
 472
 473                 len += se_dev->dev_attrib.block_size;
 474         }
 475
 476         iov_iter_bvec(&iter, READ, bvec, nolb, len);
 477         ret = vfs_iter_write(fd_dev->fd_file, &iter, &pos, 0);
 478
 479         kfree(bvec);
 480         if (ret < 0 || ret != len) {
 481                 pr_err("vfs_iter_write() returned %zd for write same\n", ret);
 482                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 483         }
 484
 485         target_complete_cmd(cmd, SAM_STAT_GOOD);
 486         return 0;
 487 }
 488
 489 static int
 490 fd_do_prot_fill(struct se_device *se_dev, sector_t lba, sector_t nolb,
 491                 void *buf, size_t bufsize)
 492 {
 493         struct fd_dev *fd_dev = FD_DEV(se_dev);
 494         struct file *prot_fd = fd_dev->fd_prot_file;
 495         sector_t prot_length, prot;
 496         loff_t pos = lba * se_dev->prot_length;
 497
 498         if (!prot_fd) {
 499                 pr_err("Unable to locate fd_dev->fd_prot_file\n");
 500                 return -ENODEV;
 501         }
 502
 503         prot_length = nolb * se_dev->prot_length;
 504
 505         memset(buf, 0xff, bufsize);
 506         for (prot = 0; prot < prot_length;) {
 507                 sector_t len = min_t(sector_t, bufsize, prot_length - prot);
 508                 ssize_t ret = kernel_write(prot_fd, buf, len, &pos);
 509
 510                 if (ret != len) {
 511                         pr_err("vfs_write to prot file failed: %zd\n", ret);
 512                         return ret < 0 ? ret : -ENODEV;
 513                 }
 514                 prot += ret;
 515         }
 516
 517         return 0;
 518 }
 519
 520 static int
 521 fd_do_prot_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
 522 {
 523         void *buf;
 524         int rc;
 525
 526         buf = (void *)__get_free_page(GFP_KERNEL);
 527         if (!buf) {
 528                 pr_err("Unable to allocate FILEIO prot buf\n");
 529                 return -ENOMEM;
 530         }
 531
 532         rc = fd_do_prot_fill(cmd->se_dev, lba, nolb, buf, PAGE_SIZE);
 533
 534         free_page((unsigned long)buf);
 535
 536         return rc;
 537 }
 538
 539 static sense_reason_t
 540 fd_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
 541 {
 542         struct file *file = FD_DEV(cmd->se_dev)->fd_file;
 543         struct inode *inode = file->f_mapping->host;
 544         int ret;
 545
 546         if (!nolb) {
 547                 return 0;
 548         }
 549
 550         if (cmd->se_dev->dev_attrib.pi_prot_type) {
 551                 ret = fd_do_prot_unmap(cmd, lba, nolb);
 552                 if (ret)
 553                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 554         }
 555
 556         if (S_ISBLK(inode->i_mode)) {
 557                 /* The backend is block device, use discard */
 558                 struct block_device *bdev = I_BDEV(inode);
 559                 struct se_device *dev = cmd->se_dev;
 560
 561                 ret = blkdev_issue_discard(bdev,
 562                                            target_to_linux_sector(dev, lba),
 563                                            target_to_linux_sector(dev,  nolb),
 564                                            GFP_KERNEL);
 565                 if (ret < 0) {
 566                         pr_warn("FILEIO: blkdev_issue_discard() failed: %d\n",
 567                                 ret);
 568                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 569                 }
 570         } else {
 571                 /* The backend is normal file, use fallocate */
 572                 struct se_device *se_dev = cmd->se_dev;
 573                 loff_t pos = lba * se_dev->dev_attrib.block_size;
 574                 unsigned int len = nolb * se_dev->dev_attrib.block_size;
 575                 int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
 576
 577                 if (!file->f_op->fallocate)
 578                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 579
 580                 ret = file->f_op->fallocate(file, mode, pos, len);
 581                 if (ret < 0) {
 582                         pr_warn("FILEIO: fallocate() failed: %d\n", ret);
 583                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 584                 }
 585         }
 586
 587         return 0;
 588 }
 589
 590 static sense_reason_t
 591 fd_execute_rw_buffered(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 592               enum dma_data_direction data_direction)
 593 {
 594         struct se_device *dev = cmd->se_dev;
 595         struct fd_dev *fd_dev = FD_DEV(dev);
 596         struct file *file = fd_dev->fd_file;
 597         struct file *pfile = fd_dev->fd_prot_file;
 598         sense_reason_t rc;
 599         int ret = 0;
 600         /*
 601          * Call vectorized fileio functions to map struct scatterlist
 602          * physical memory addresses to struct iovec virtual memory.
 603          */
 604         if (data_direction == DMA_FROM_DEVICE) {
 605                 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 606                         ret = fd_do_rw(cmd, pfile, dev->prot_length,
 607                                        cmd->t_prot_sg, cmd->t_prot_nents,
 608                                        cmd->prot_length, 0);
 609                         if (ret < 0)
 610                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 611                 }
 612
 613                 ret = fd_do_rw(cmd, file, dev->dev_attrib.block_size,
 614                                sgl, sgl_nents, cmd->data_length, 0);
 615
 616                 if (ret > 0 && cmd->prot_type && dev->dev_attrib.pi_prot_type &&
 617                     dev->dev_attrib.pi_prot_verify) {
 618                         u32 sectors = cmd->data_length >>
 619                                         ilog2(dev->dev_attrib.block_size);
 620
 621                         rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors,
 622                                             0, cmd->t_prot_sg, 0);
 623                         if (rc)
 624                                 return rc;
 625                 }
 626         } else {
 627                 if (cmd->prot_type && dev->dev_attrib.pi_prot_type &&
 628                     dev->dev_attrib.pi_prot_verify) {
 629                         u32 sectors = cmd->data_length >>
 630                                         ilog2(dev->dev_attrib.block_size);
 631
 632                         rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors,
 633                                             0, cmd->t_prot_sg, 0);
 634                         if (rc)
 635                                 return rc;
 636                 }
 637
 638                 ret = fd_do_rw(cmd, file, dev->dev_attrib.block_size,
 639                                sgl, sgl_nents, cmd->data_length, 1);
 640                 /*
 641                  * Perform implicit vfs_fsync_range() for fd_do_writev() ops
 642                  * for SCSI WRITEs with Forced Unit Access (FUA) set.
 643                  * Allow this to happen independent of WCE=0 setting.
 644                  */
 645                 if (ret > 0 && (cmd->se_cmd_flags & SCF_FUA)) {
 646                         loff_t start = cmd->t_task_lba *
 647                                 dev->dev_attrib.block_size;
 648                         loff_t end;
 649
 650                         if (cmd->data_length)
 651                                 end = start + cmd->data_length - 1;
 652                         else
 653                                 end = LLONG_MAX;
 654
 655                         vfs_fsync_range(fd_dev->fd_file, start, end, 1);
 656                 }
 657
 658                 if (ret > 0 && cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 659                         ret = fd_do_rw(cmd, pfile, dev->prot_length,
 660                                        cmd->t_prot_sg, cmd->t_prot_nents,
 661                                        cmd->prot_length, 1);
 662                         if (ret < 0)
 663                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 664                 }
 665         }
 666
 667         if (ret < 0)
 668                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 669
 670         target_complete_cmd(cmd, SAM_STAT_GOOD);
 671         return 0;
 672 }
 673
 674 static sense_reason_t
 675 fd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 676               enum dma_data_direction data_direction)
 677 {
 678         struct se_device *dev = cmd->se_dev;
 679         struct fd_dev *fd_dev = FD_DEV(dev);
 680
 681         /*
 682          * We are currently limited by the number of iovecs (2048) per
 683          * single vfs_[writev,readv] call.
 684          */
 685         if (cmd->data_length > FD_MAX_BYTES) {
 686                 pr_err("FILEIO: Not able to process I/O of %u bytes due to"
 687                        "FD_MAX_BYTES: %u iovec count limitation\n",
 688                         cmd->data_length, FD_MAX_BYTES);
 689                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 690         }
 691
 692         if (fd_dev->fbd_flags & FDBD_HAS_ASYNC_IO)
 693                 return fd_execute_rw_aio(cmd, sgl, sgl_nents, data_direction);
 694         return fd_execute_rw_buffered(cmd, sgl, sgl_nents, data_direction);
 695 }
 696
 697 enum {
 698         Opt_fd_dev_name, Opt_fd_dev_size, Opt_fd_buffered_io,
 699         Opt_fd_async_io, Opt_err
 700 };
 701
 702 static match_table_t tokens = {
 703         {Opt_fd_dev_name, "fd_dev_name=%s"},
 704         {Opt_fd_dev_size, "fd_dev_size=%s"},
 705         {Opt_fd_buffered_io, "fd_buffered_io=%d"},
 706         {Opt_fd_async_io, "fd_async_io=%d"},
 707         {Opt_err, NULL}
 708 };
 709
 710 static ssize_t fd_set_configfs_dev_params(struct se_device *dev,
 711                 const char *page, ssize_t count)
 712 {
 713         struct fd_dev *fd_dev = FD_DEV(dev);
 714         char *orig, *ptr, *arg_p, *opts;
 715         substring_t args[MAX_OPT_ARGS];
 716         int ret = 0, arg, token;
 717
 718         opts = kstrdup(page, GFP_KERNEL);
 719         if (!opts)
 720                 return -ENOMEM;
 721
 722         orig = opts;
 723
 724         while ((ptr = strsep(&opts, ",\n")) != NULL) {
 725                 if (!*ptr)
 726                         continue;
 727
 728                 token = match_token(ptr, tokens, args);
 729                 switch (token) {
 730                 case Opt_fd_dev_name:
 731                         if (match_strlcpy(fd_dev->fd_dev_name, &args[0],
 732                                 FD_MAX_DEV_NAME) == 0) {
 733                                 ret = -EINVAL;
 734                                 break;
 735                         }
 736                         pr_debug("FILEIO: Referencing Path: %s\n",
 737                                         fd_dev->fd_dev_name);
 738                         fd_dev->fbd_flags |= FBDF_HAS_PATH;
 739                         break;
 740                 case Opt_fd_dev_size:
 741                         arg_p = match_strdup(&args[0]);
 742                         if (!arg_p) {
 743                                 ret = -ENOMEM;
 744                                 break;
 745                         }
 746                         ret = kstrtoull(arg_p, 0, &fd_dev->fd_dev_size);
 747                         kfree(arg_p);
 748                         if (ret < 0) {
 749                                 pr_err("kstrtoull() failed for"
 750                                                 " fd_dev_size=\n");
 751                                 goto out;
 752                         }
 753                         pr_debug("FILEIO: Referencing Size: %llu"
 754                                         " bytes\n", fd_dev->fd_dev_size);
 755                         fd_dev->fbd_flags |= FBDF_HAS_SIZE;
 756                         break;
 757                 case Opt_fd_buffered_io:
 758                         ret = match_int(args, &arg);
 759                         if (ret)
 760                                 goto out;
 761                         if (arg != 1) {
 762                                 pr_err("bogus fd_buffered_io=%d value\n", arg);
 763                                 ret = -EINVAL;
 764                                 goto out;
 765                         }
 766
 767                         pr_debug("FILEIO: Using buffered I/O"
 768                                 " operations for struct fd_dev\n");
 769
 770                         fd_dev->fbd_flags |= FDBD_HAS_BUFFERED_IO_WCE;
 771                         break;
 772                 case Opt_fd_async_io:
 773                         ret = match_int(args, &arg);
 774                         if (ret)
 775                                 goto out;
 776                         if (arg != 1) {
 777                                 pr_err("bogus fd_async_io=%d value\n", arg);
 778                                 ret = -EINVAL;
 779                                 goto out;
 780                         }
 781
 782                         pr_debug("FILEIO: Using async I/O"
 783                                 " operations for struct fd_dev\n");
 784
 785                         fd_dev->fbd_flags |= FDBD_HAS_ASYNC_IO;
 786                         break;
 787                 default:
 788                         break;
 789                 }
 790         }
 791
 792 out:
 793         kfree(orig);
 794         return (!ret) ? count : ret;
 795 }
 796
 797 static ssize_t fd_show_configfs_dev_params(struct se_device *dev, char *b)
 798 {
 799         struct fd_dev *fd_dev = FD_DEV(dev);
 800         ssize_t bl = 0;
 801
 802         bl = sprintf(b + bl, "TCM FILEIO ID: %u", fd_dev->fd_dev_id);
 803         bl += sprintf(b + bl, "        File: %s  Size: %llu  Mode: %s Async: %d\n",
 804                 fd_dev->fd_dev_name, fd_dev->fd_dev_size,
 805                 (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) ?
 806                 "Buffered-WCE" : "O_DSYNC",
 807                 !!(fd_dev->fbd_flags & FDBD_HAS_ASYNC_IO));
 808         return bl;
 809 }
 810
 811 static sector_t fd_get_blocks(struct se_device *dev)
 812 {
 813         struct fd_dev *fd_dev = FD_DEV(dev);
 814         struct file *f = fd_dev->fd_file;
 815         struct inode *i = f->f_mapping->host;
 816         unsigned long long dev_size;
 817         /*
 818          * When using a file that references an underlying struct block_device,
 819          * ensure dev_size is always based on the current inode size in order
 820          * to handle underlying block_device resize operations.
 821          */
 822         if (S_ISBLK(i->i_mode))
 823                 dev_size = i_size_read(i);
 824         else
 825                 dev_size = fd_dev->fd_dev_size;
 826
 827         return div_u64(dev_size - dev->dev_attrib.block_size,
 828                        dev->dev_attrib.block_size);
 829 }
 830
 831 static int fd_init_prot(struct se_device *dev)
 832 {
 833         struct fd_dev *fd_dev = FD_DEV(dev);
 834         struct file *prot_file, *file = fd_dev->fd_file;
 835         struct inode *inode;
 836         int ret, flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
 837         char buf[FD_MAX_DEV_PROT_NAME];
 838
 839         if (!file) {
 840                 pr_err("Unable to locate fd_dev->fd_file\n");
 841                 return -ENODEV;
 842         }
 843
 844         inode = file->f_mapping->host;
 845         if (S_ISBLK(inode->i_mode)) {
 846                 pr_err("FILEIO Protection emulation only supported on"
 847                        " !S_ISBLK\n");
 848                 return -ENOSYS;
 849         }
 850
 851         if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE)
 852                 flags &= ~O_DSYNC;
 853
 854         snprintf(buf, FD_MAX_DEV_PROT_NAME, "%s.protection",
 855                  fd_dev->fd_dev_name);
 856
 857         prot_file = filp_open(buf, flags, 0600);
 858         if (IS_ERR(prot_file)) {
 859                 pr_err("filp_open(%s) failed\n", buf);
 860                 ret = PTR_ERR(prot_file);
 861                 return ret;
 862         }
 863         fd_dev->fd_prot_file = prot_file;
 864
 865         return 0;
 866 }
 867
 868 static int fd_format_prot(struct se_device *dev)
 869 {
 870         unsigned char *buf;
 871         int unit_size = FDBD_FORMAT_UNIT_SIZE * dev->dev_attrib.block_size;
 872         int ret;
 873
 874         if (!dev->dev_attrib.pi_prot_type) {
 875                 pr_err("Unable to format_prot while pi_prot_type == 0\n");
 876                 return -ENODEV;
 877         }
 878
 879         buf = vzalloc(unit_size);
 880         if (!buf) {
 881                 pr_err("Unable to allocate FILEIO prot buf\n");
 882                 return -ENOMEM;
 883         }
 884
 885         pr_debug("Using FILEIO prot_length: %llu\n",
 886                  (unsigned long long)(dev->transport->get_blocks(dev) + 1) *
 887                                         dev->prot_length);
 888
 889         ret = fd_do_prot_fill(dev, 0, dev->transport->get_blocks(dev) + 1,
 890                               buf, unit_size);
 891         vfree(buf);
 892         return ret;
 893 }
 894
 895 static void fd_free_prot(struct se_device *dev)
 896 {
 897         struct fd_dev *fd_dev = FD_DEV(dev);
 898
 899         if (!fd_dev->fd_prot_file)
 900                 return;
 901
 902         filp_close(fd_dev->fd_prot_file, NULL);
 903         fd_dev->fd_prot_file = NULL;
 904 }
 905
 906 static struct sbc_ops fd_sbc_ops = {
 907         .execute_rw             = fd_execute_rw,
 908         .execute_sync_cache     = fd_execute_sync_cache,
 909         .execute_write_same     = fd_execute_write_same,
 910         .execute_unmap          = fd_execute_unmap,
 911 };
 912
 913 static sense_reason_t
 914 fd_parse_cdb(struct se_cmd *cmd)
 915 {
 916         return sbc_parse_cdb(cmd, &fd_sbc_ops);
 917 }
 918
 919 static const struct target_backend_ops fileio_ops = {
 920         .name                   = "fileio",
 921         .inquiry_prod           = "FILEIO",
 922         .inquiry_rev            = FD_VERSION,
 923         .owner                  = THIS_MODULE,
 924         .attach_hba             = fd_attach_hba,
 925         .detach_hba             = fd_detach_hba,
 926         .alloc_device           = fd_alloc_device,
 927         .configure_device       = fd_configure_device,
 928         .destroy_device         = fd_destroy_device,
 929         .free_device            = fd_free_device,
 930         .configure_unmap        = fd_configure_unmap,
 931         .parse_cdb              = fd_parse_cdb,
 932         .set_configfs_dev_params = fd_set_configfs_dev_params,
 933         .show_configfs_dev_params = fd_show_configfs_dev_params,
 934         .get_device_type        = sbc_get_device_type,
 935         .get_blocks             = fd_get_blocks,
 936         .init_prot              = fd_init_prot,
 937         .format_prot            = fd_format_prot,
 938         .free_prot              = fd_free_prot,
 939         .tb_dev_attrib_attrs    = sbc_attrib_attrs,
 940 };
 941
 942 static int __init fileio_module_init(void)
 943 {
 944         return transport_backend_register(&fileio_ops);
 945 }
 946
 947 static void __exit fileio_module_exit(void)
 948 {
 949         target_backend_unregister(&fileio_ops);
 950 }
 951
 952 MODULE_DESCRIPTION("TCM FILEIO subsystem plugin");
 953 MODULE_AUTHOR("[email protected]");
 954 MODULE_LICENSE("GPL");
 955
 956 module_init(fileio_module_init);
 957 module_exit(fileio_module_exit);