drivers/target/target_core_file.c

   1 /*******************************************************************************
   2  * Filename:  target_core_file.c
   3  *
   4  * This file contains the Storage Engine <-> FILEIO transport specific functions
   5  *
   6  * (c) Copyright 2005-2013 Datera, Inc.
   7  *
   8  * Nicholas A. Bellinger <nab@kernel.org>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23  *
  24  ******************************************************************************/
  25
  26 #include <linux/string.h>
  27 #include <linux/parser.h>
  28 #include <linux/timer.h>
  29 #include <linux/blkdev.h>
  30 #include <linux/slab.h>
  31 #include <linux/spinlock.h>
  32 #include <linux/module.h>
  33 #include <linux/vmalloc.h>
  34 #include <linux/falloc.h>
  35 #include <linux/uio.h>
  36 #include <scsi/scsi_proto.h>
  37 #include <asm/unaligned.h>
  38
  39 #include <target/target_core_base.h>
  40 #include <target/target_core_backend.h>
  41
  42 #include "target_core_file.h"
  43
  44 static inline struct fd_dev *FD_DEV(struct se_device *dev)
  45 {
  46         return container_of(dev, struct fd_dev, dev);
  47 }
  48
  49 static int fd_attach_hba(struct se_hba *hba, u32 host_id)
  50 {
  51         struct fd_host *fd_host;
  52
  53         fd_host = kzalloc(sizeof(struct fd_host), GFP_KERNEL);
  54         if (!fd_host) {
  55                 pr_err("Unable to allocate memory for struct fd_host\n");
  56                 return -ENOMEM;
  57         }
  58
  59         fd_host->fd_host_id = host_id;
  60
  61         hba->hba_ptr = fd_host;
  62
  63         pr_debug("CORE_HBA[%d] - TCM FILEIO HBA Driver %s on Generic"
  64                 " Target Core Stack %s\n", hba->hba_id, FD_VERSION,
  65                 TARGET_CORE_VERSION);
  66         pr_debug("CORE_HBA[%d] - Attached FILEIO HBA: %u to Generic\n",
  67                 hba->hba_id, fd_host->fd_host_id);
  68
  69         return 0;
  70 }
  71
  72 static void fd_detach_hba(struct se_hba *hba)
  73 {
  74         struct fd_host *fd_host = hba->hba_ptr;
  75
  76         pr_debug("CORE_HBA[%d] - Detached FILEIO HBA: %u from Generic"
  77                 " Target Core\n", hba->hba_id, fd_host->fd_host_id);
  78
  79         kfree(fd_host);
  80         hba->hba_ptr = NULL;
  81 }
  82
  83 static struct se_device *fd_alloc_device(struct se_hba *hba, const char *name)
  84 {
  85         struct fd_dev *fd_dev;
  86         struct fd_host *fd_host = hba->hba_ptr;
  87
  88         fd_dev = kzalloc(sizeof(struct fd_dev), GFP_KERNEL);
  89         if (!fd_dev) {
  90                 pr_err("Unable to allocate memory for struct fd_dev\n");
  91                 return NULL;
  92         }
  93
  94         fd_dev->fd_host = fd_host;
  95
  96         pr_debug("FILEIO: Allocated fd_dev for %p\n", name);
  97
  98         return &fd_dev->dev;
  99 }
 100
 101 static int fd_configure_device(struct se_device *dev)
 102 {
 103         struct fd_dev *fd_dev = FD_DEV(dev);
 104         struct fd_host *fd_host = dev->se_hba->hba_ptr;
 105         struct file *file;
 106         struct inode *inode = NULL;
 107         int flags, ret = -EINVAL;
 108
 109         if (!(fd_dev->fbd_flags & FBDF_HAS_PATH)) {
 110                 pr_err("Missing fd_dev_name=\n");
 111                 return -EINVAL;
 112         }
 113
 114         /*
 115          * Use O_DSYNC by default instead of O_SYNC to forgo syncing
 116          * of pure timestamp updates.
 117          */
 118         flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
 119
 120         /*
 121          * Optionally allow fd_buffered_io=1 to be enabled for people
 122          * who want use the fs buffer cache as an WriteCache mechanism.
 123          *
 124          * This means that in event of a hard failure, there is a risk
 125          * of silent data-loss if the SCSI client has *not* performed a
 126          * forced unit access (FUA) write, or issued SYNCHRONIZE_CACHE
 127          * to write-out the entire device cache.
 128          */
 129         if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
 130                 pr_debug("FILEIO: Disabling O_DSYNC, using buffered FILEIO\n");
 131                 flags &= ~O_DSYNC;
 132         }
 133
 134         file = filp_open(fd_dev->fd_dev_name, flags, 0600);
 135         if (IS_ERR(file)) {
 136                 pr_err("filp_open(%s) failed\n", fd_dev->fd_dev_name);
 137                 ret = PTR_ERR(file);
 138                 goto fail;
 139         }
 140         fd_dev->fd_file = file;
 141         /*
 142          * If using a block backend with this struct file, we extract
 143          * fd_dev->fd_[block,dev]_size from struct block_device.
 144          *
 145          * Otherwise, we use the passed fd_size= from configfs
 146          */
 147         inode = file->f_mapping->host;
 148         if (S_ISBLK(inode->i_mode)) {
 149                 struct request_queue *q = bdev_get_queue(inode->i_bdev);
 150                 unsigned long long dev_size;
 151
 152                 fd_dev->fd_block_size = bdev_logical_block_size(inode->i_bdev);
 153                 /*
 154                  * Determine the number of bytes from i_size_read() minus
 155                  * one (1) logical sector from underlying struct block_device
 156                  */
 157                 dev_size = (i_size_read(file->f_mapping->host) -
 158                                        fd_dev->fd_block_size);
 159
 160                 pr_debug("FILEIO: Using size: %llu bytes from struct"
 161                         " block_device blocks: %llu logical_block_size: %d\n",
 162                         dev_size, div_u64(dev_size, fd_dev->fd_block_size),
 163                         fd_dev->fd_block_size);
 164
 165                 if (target_configure_unmap_from_queue(&dev->dev_attrib, q))
 166                         pr_debug("IFILE: BLOCK Discard support available,"
 167                                  " disabled by default\n");
 168                 /*
 169                  * Enable write same emulation for IBLOCK and use 0xFFFF as
 170                  * the smaller WRITE_SAME(10) only has a two-byte block count.
 171                  */
 172                 dev->dev_attrib.max_write_same_len = 0xFFFF;
 173
 174                 if (blk_queue_nonrot(q))
 175                         dev->dev_attrib.is_nonrot = 1;
 176         } else {
 177                 if (!(fd_dev->fbd_flags & FBDF_HAS_SIZE)) {
 178                         pr_err("FILEIO: Missing fd_dev_size="
 179                                 " parameter, and no backing struct"
 180                                 " block_device\n");
 181                         goto fail;
 182                 }
 183
 184                 fd_dev->fd_block_size = FD_BLOCKSIZE;
 185                 /*
 186                  * Limit UNMAP emulation to 8k Number of LBAs (NoLB)
 187                  */
 188                 dev->dev_attrib.max_unmap_lba_count = 0x2000;
 189                 /*
 190                  * Currently hardcoded to 1 in Linux/SCSI code..
 191                  */
 192                 dev->dev_attrib.max_unmap_block_desc_count = 1;
 193                 dev->dev_attrib.unmap_granularity = 1;
 194                 dev->dev_attrib.unmap_granularity_alignment = 0;
 195
 196                 /*
 197                  * Limit WRITE_SAME w/ UNMAP=0 emulation to 8k Number of LBAs (NoLB)
 198                  * based upon struct iovec limit for vfs_writev()
 199                  */
 200                 dev->dev_attrib.max_write_same_len = 0x1000;
 201         }
 202
 203         dev->dev_attrib.hw_block_size = fd_dev->fd_block_size;
 204         dev->dev_attrib.max_bytes_per_io = FD_MAX_BYTES;
 205         dev->dev_attrib.hw_max_sectors = FD_MAX_BYTES / fd_dev->fd_block_size;
 206         dev->dev_attrib.hw_queue_depth = FD_MAX_DEVICE_QUEUE_DEPTH;
 207
 208         if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
 209                 pr_debug("FILEIO: Forcing setting of emulate_write_cache=1"
 210                         " with FDBD_HAS_BUFFERED_IO_WCE\n");
 211                 dev->dev_attrib.emulate_write_cache = 1;
 212         }
 213
 214         fd_dev->fd_dev_id = fd_host->fd_host_dev_id_count++;
 215         fd_dev->fd_queue_depth = dev->queue_depth;
 216
 217         pr_debug("CORE_FILE[%u] - Added TCM FILEIO Device ID: %u at %s,"
 218                 " %llu total bytes\n", fd_host->fd_host_id, fd_dev->fd_dev_id,
 219                         fd_dev->fd_dev_name, fd_dev->fd_dev_size);
 220
 221         return 0;
 222 fail:
 223         if (fd_dev->fd_file) {
 224                 filp_close(fd_dev->fd_file, NULL);
 225                 fd_dev->fd_file = NULL;
 226         }
 227         return ret;
 228 }
 229
 230 static void fd_dev_call_rcu(struct rcu_head *p)
 231 {
 232         struct se_device *dev = container_of(p, struct se_device, rcu_head);
 233         struct fd_dev *fd_dev = FD_DEV(dev);
 234
 235         kfree(fd_dev);
 236 }
 237
 238 static void fd_free_device(struct se_device *dev)
 239 {
 240         call_rcu(&dev->rcu_head, fd_dev_call_rcu);
 241 }
 242
 243 static void fd_destroy_device(struct se_device *dev)
 244 {
 245         struct fd_dev *fd_dev = FD_DEV(dev);
 246
 247         if (fd_dev->fd_file) {
 248                 filp_close(fd_dev->fd_file, NULL);
 249                 fd_dev->fd_file = NULL;
 250         }
 251 }
 252
 253 struct target_core_file_cmd {
 254         unsigned long   len;
 255         struct se_cmd   *cmd;
 256         struct kiocb    iocb;
 257 };
 258
 259 static void cmd_rw_aio_complete(struct kiocb *iocb, long ret, long ret2)
 260 {
 261         struct target_core_file_cmd *cmd;
 262
 263         cmd = container_of(iocb, struct target_core_file_cmd, iocb);
 264
 265         if (ret != cmd->len)
 266                 target_complete_cmd(cmd->cmd, SAM_STAT_CHECK_CONDITION);
 267         else
 268                 target_complete_cmd(cmd->cmd, SAM_STAT_GOOD);
 269
 270         kfree(cmd);
 271 }
 272
 273 static sense_reason_t
 274 fd_execute_rw_aio(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 275               enum dma_data_direction data_direction)
 276 {
 277         int is_write = !(data_direction == DMA_FROM_DEVICE);
 278         struct se_device *dev = cmd->se_dev;
 279         struct fd_dev *fd_dev = FD_DEV(dev);
 280         struct file *file = fd_dev->fd_file;
 281         struct target_core_file_cmd *aio_cmd;
 282         struct iov_iter iter = {};
 283         struct scatterlist *sg;
 284         struct bio_vec *bvec;
 285         ssize_t len = 0;
 286         int ret = 0, i;
 287
 288         aio_cmd = kmalloc(sizeof(struct target_core_file_cmd), GFP_KERNEL);
 289         if (!aio_cmd)
 290                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 291
 292         bvec = kcalloc(sgl_nents, sizeof(struct bio_vec), GFP_KERNEL);
 293         if (!bvec) {
 294                 kfree(aio_cmd);
 295                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 296         }
 297
 298         for_each_sg(sgl, sg, sgl_nents, i) {
 299                 bvec[i].bv_page = sg_page(sg);
 300                 bvec[i].bv_len = sg->length;
 301                 bvec[i].bv_offset = sg->offset;
 302
 303                 len += sg->length;
 304         }
 305
 306         iov_iter_bvec(&iter, is_write, bvec, sgl_nents, len);
 307
 308         aio_cmd->cmd = cmd;
 309         aio_cmd->len = len;
 310         aio_cmd->iocb.ki_pos = cmd->t_task_lba * dev->dev_attrib.block_size;
 311         aio_cmd->iocb.ki_filp = file;
 312         aio_cmd->iocb.ki_complete = cmd_rw_aio_complete;
 313         aio_cmd->iocb.ki_flags = IOCB_DIRECT;
 314
 315         if (is_write && (cmd->se_cmd_flags & SCF_FUA))
 316                 aio_cmd->iocb.ki_flags |= IOCB_DSYNC;
 317
 318         if (is_write)
 319                 ret = call_write_iter(file, &aio_cmd->iocb, &iter);
 320         else
 321                 ret = call_read_iter(file, &aio_cmd->iocb, &iter);
 322
 323         kfree(bvec);
 324
 325         if (ret != -EIOCBQUEUED)
 326                 cmd_rw_aio_complete(&aio_cmd->iocb, ret, 0);
 327
 328         return 0;
 329 }
 330
 331 static int fd_do_rw(struct se_cmd *cmd, struct file *fd,
 332                     u32 block_size, struct scatterlist *sgl,
 333                     u32 sgl_nents, u32 data_length, int is_write)
 334 {
 335         struct scatterlist *sg;
 336         struct iov_iter iter;
 337         struct bio_vec *bvec;
 338         ssize_t len = 0;
 339         loff_t pos = (cmd->t_task_lba * block_size);
 340         int ret = 0, i;
 341
 342         bvec = kcalloc(sgl_nents, sizeof(struct bio_vec), GFP_KERNEL);
 343         if (!bvec) {
 344                 pr_err("Unable to allocate fd_do_readv iov[]\n");
 345                 return -ENOMEM;
 346         }
 347
 348         for_each_sg(sgl, sg, sgl_nents, i) {
 349                 bvec[i].bv_page = sg_page(sg);
 350                 bvec[i].bv_len = sg->length;
 351                 bvec[i].bv_offset = sg->offset;
 352
 353                 len += sg->length;
 354         }
 355
 356         iov_iter_bvec(&iter, READ, bvec, sgl_nents, len);
 357         if (is_write)
 358                 ret = vfs_iter_write(fd, &iter, &pos, 0);
 359         else
 360                 ret = vfs_iter_read(fd, &iter, &pos, 0);
 361
 362         if (is_write) {
 363                 if (ret < 0 || ret != data_length) {
 364                         pr_err("%s() write returned %d\n", __func__, ret);
 365                         if (ret >= 0)
 366                                 ret = -EINVAL;
 367                 }
 368         } else {
 369                 /*
 370                  * Return zeros and GOOD status even if the READ did not return
 371                  * the expected virt_size for struct file w/o a backing struct
 372                  * block_device.
 373                  */
 374                 if (S_ISBLK(file_inode(fd)->i_mode)) {
 375                         if (ret < 0 || ret != data_length) {
 376                                 pr_err("%s() returned %d, expecting %u for "
 377                                                 "S_ISBLK\n", __func__, ret,
 378                                                 data_length);
 379                                 if (ret >= 0)
 380                                         ret = -EINVAL;
 381                         }
 382                 } else {
 383                         if (ret < 0) {
 384                                 pr_err("%s() returned %d for non S_ISBLK\n",
 385                                                 __func__, ret);
 386                         } else if (ret != data_length) {
 387                                 /*
 388                                  * Short read case:
 389                                  * Probably some one truncate file under us.
 390                                  * We must explicitly zero sg-pages to prevent
 391                                  * expose uninizialized pages to userspace.
 392                                  */
 393                                 if (ret < data_length)
 394                                         ret += iov_iter_zero(data_length - ret, &iter);
 395                                 else
 396                                         ret = -EINVAL;
 397                         }
 398                 }
 399         }
 400         kfree(bvec);
 401         return ret;
 402 }
 403
 404 static sense_reason_t
 405 fd_execute_sync_cache(struct se_cmd *cmd)
 406 {
 407         struct se_device *dev = cmd->se_dev;
 408         struct fd_dev *fd_dev = FD_DEV(dev);
 409         int immed = (cmd->t_task_cdb[1] & 0x2);
 410         loff_t start, end;
 411         int ret;
 412
 413         /*
 414          * If the Immediate bit is set, queue up the GOOD response
 415          * for this SYNCHRONIZE_CACHE op
 416          */
 417         if (immed)
 418                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 419
 420         /*
 421          * Determine if we will be flushing the entire device.
 422          */
 423         if (cmd->t_task_lba == 0 && cmd->data_length == 0) {
 424                 start = 0;
 425                 end = LLONG_MAX;
 426         } else {
 427                 start = cmd->t_task_lba * dev->dev_attrib.block_size;
 428                 if (cmd->data_length)
 429                         end = start + cmd->data_length - 1;
 430                 else
 431                         end = LLONG_MAX;
 432         }
 433
 434         ret = vfs_fsync_range(fd_dev->fd_file, start, end, 1);
 435         if (ret != 0)
 436                 pr_err("FILEIO: vfs_fsync_range() failed: %d\n", ret);
 437
 438         if (immed)
 439                 return 0;
 440
 441         if (ret)
 442                 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
 443         else
 444                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 445
 446         return 0;
 447 }
 448
 449 static sense_reason_t
 450 fd_execute_write_same(struct se_cmd *cmd)
 451 {
 452         struct se_device *se_dev = cmd->se_dev;
 453         struct fd_dev *fd_dev = FD_DEV(se_dev);
 454         loff_t pos = cmd->t_task_lba * se_dev->dev_attrib.block_size;
 455         sector_t nolb = sbc_get_write_same_sectors(cmd);
 456         struct iov_iter iter;
 457         struct bio_vec *bvec;
 458         unsigned int len = 0, i;
 459         ssize_t ret;
 460
 461         if (!nolb) {
 462                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 463                 return 0;
 464         }
 465         if (cmd->prot_op) {
 466                 pr_err("WRITE_SAME: Protection information with FILEIO"
 467                        " backends not supported\n");
 468                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 469         }
 470
 471         if (cmd->t_data_nents > 1 ||
 472             cmd->t_data_sg[0].length != cmd->se_dev->dev_attrib.block_size) {
 473                 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
 474                         " block_size: %u\n",
 475                         cmd->t_data_nents,
 476                         cmd->t_data_sg[0].length,
 477                         cmd->se_dev->dev_attrib.block_size);
 478                 return TCM_INVALID_CDB_FIELD;
 479         }
 480
 481         bvec = kcalloc(nolb, sizeof(struct bio_vec), GFP_KERNEL);
 482         if (!bvec)
 483                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 484
 485         for (i = 0; i < nolb; i++) {
 486                 bvec[i].bv_page = sg_page(&cmd->t_data_sg[0]);
 487                 bvec[i].bv_len = cmd->t_data_sg[0].length;
 488                 bvec[i].bv_offset = cmd->t_data_sg[0].offset;
 489
 490                 len += se_dev->dev_attrib.block_size;
 491         }
 492
 493         iov_iter_bvec(&iter, READ, bvec, nolb, len);
 494         ret = vfs_iter_write(fd_dev->fd_file, &iter, &pos, 0);
 495
 496         kfree(bvec);
 497         if (ret < 0 || ret != len) {
 498                 pr_err("vfs_iter_write() returned %zd for write same\n", ret);
 499                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 500         }
 501
 502         target_complete_cmd(cmd, SAM_STAT_GOOD);
 503         return 0;
 504 }
 505
 506 static int
 507 fd_do_prot_fill(struct se_device *se_dev, sector_t lba, sector_t nolb,
 508                 void *buf, size_t bufsize)
 509 {
 510         struct fd_dev *fd_dev = FD_DEV(se_dev);
 511         struct file *prot_fd = fd_dev->fd_prot_file;
 512         sector_t prot_length, prot;
 513         loff_t pos = lba * se_dev->prot_length;
 514
 515         if (!prot_fd) {
 516                 pr_err("Unable to locate fd_dev->fd_prot_file\n");
 517                 return -ENODEV;
 518         }
 519
 520         prot_length = nolb * se_dev->prot_length;
 521
 522         for (prot = 0; prot < prot_length;) {
 523                 sector_t len = min_t(sector_t, bufsize, prot_length - prot);
 524                 ssize_t ret = kernel_write(prot_fd, buf, len, &pos);
 525
 526                 if (ret != len) {
 527                         pr_err("vfs_write to prot file failed: %zd\n", ret);
 528                         return ret < 0 ? ret : -ENODEV;
 529                 }
 530                 prot += ret;
 531         }
 532
 533         return 0;
 534 }
 535
 536 static int
 537 fd_do_prot_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
 538 {
 539         void *buf;
 540         int rc;
 541
 542         buf = (void *)__get_free_page(GFP_KERNEL);
 543         if (!buf) {
 544                 pr_err("Unable to allocate FILEIO prot buf\n");
 545                 return -ENOMEM;
 546         }
 547         memset(buf, 0xff, PAGE_SIZE);
 548
 549         rc = fd_do_prot_fill(cmd->se_dev, lba, nolb, buf, PAGE_SIZE);
 550
 551         free_page((unsigned long)buf);
 552
 553         return rc;
 554 }
 555
 556 static sense_reason_t
 557 fd_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
 558 {
 559         struct file *file = FD_DEV(cmd->se_dev)->fd_file;
 560         struct inode *inode = file->f_mapping->host;
 561         int ret;
 562
 563         if (!nolb) {
 564                 return 0;
 565         }
 566
 567         if (cmd->se_dev->dev_attrib.pi_prot_type) {
 568                 ret = fd_do_prot_unmap(cmd, lba, nolb);
 569                 if (ret)
 570                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 571         }
 572
 573         if (S_ISBLK(inode->i_mode)) {
 574                 /* The backend is block device, use discard */
 575                 struct block_device *bdev = inode->i_bdev;
 576                 struct se_device *dev = cmd->se_dev;
 577
 578                 ret = blkdev_issue_discard(bdev,
 579                                            target_to_linux_sector(dev, lba),
 580                                            target_to_linux_sector(dev,  nolb),
 581                                            GFP_KERNEL, 0);
 582                 if (ret < 0) {
 583                         pr_warn("FILEIO: blkdev_issue_discard() failed: %d\n",
 584                                 ret);
 585                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 586                 }
 587         } else {
 588                 /* The backend is normal file, use fallocate */
 589                 struct se_device *se_dev = cmd->se_dev;
 590                 loff_t pos = lba * se_dev->dev_attrib.block_size;
 591                 unsigned int len = nolb * se_dev->dev_attrib.block_size;
 592                 int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
 593
 594                 if (!file->f_op->fallocate)
 595                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 596
 597                 ret = file->f_op->fallocate(file, mode, pos, len);
 598                 if (ret < 0) {
 599                         pr_warn("FILEIO: fallocate() failed: %d\n", ret);
 600                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 601                 }
 602         }
 603
 604         return 0;
 605 }
 606
 607 static sense_reason_t
 608 fd_execute_rw_buffered(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 609               enum dma_data_direction data_direction)
 610 {
 611         struct se_device *dev = cmd->se_dev;
 612         struct fd_dev *fd_dev = FD_DEV(dev);
 613         struct file *file = fd_dev->fd_file;
 614         struct file *pfile = fd_dev->fd_prot_file;
 615         sense_reason_t rc;
 616         int ret = 0;
 617         /*
 618          * Call vectorized fileio functions to map struct scatterlist
 619          * physical memory addresses to struct iovec virtual memory.
 620          */
 621         if (data_direction == DMA_FROM_DEVICE) {
 622                 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 623                         ret = fd_do_rw(cmd, pfile, dev->prot_length,
 624                                        cmd->t_prot_sg, cmd->t_prot_nents,
 625                                        cmd->prot_length, 0);
 626                         if (ret < 0)
 627                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 628                 }
 629
 630                 ret = fd_do_rw(cmd, file, dev->dev_attrib.block_size,
 631                                sgl, sgl_nents, cmd->data_length, 0);
 632
 633                 if (ret > 0 && cmd->prot_type && dev->dev_attrib.pi_prot_type &&
 634                     dev->dev_attrib.pi_prot_verify) {
 635                         u32 sectors = cmd->data_length >>
 636                                         ilog2(dev->dev_attrib.block_size);
 637
 638                         rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors,
 639                                             0, cmd->t_prot_sg, 0);
 640                         if (rc)
 641                                 return rc;
 642                 }
 643         } else {
 644                 if (cmd->prot_type && dev->dev_attrib.pi_prot_type &&
 645                     dev->dev_attrib.pi_prot_verify) {
 646                         u32 sectors = cmd->data_length >>
 647                                         ilog2(dev->dev_attrib.block_size);
 648
 649                         rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors,
 650                                             0, cmd->t_prot_sg, 0);
 651                         if (rc)
 652                                 return rc;
 653                 }
 654
 655                 ret = fd_do_rw(cmd, file, dev->dev_attrib.block_size,
 656                                sgl, sgl_nents, cmd->data_length, 1);
 657                 /*
 658                  * Perform implicit vfs_fsync_range() for fd_do_writev() ops
 659                  * for SCSI WRITEs with Forced Unit Access (FUA) set.
 660                  * Allow this to happen independent of WCE=0 setting.
 661                  */
 662                 if (ret > 0 && (cmd->se_cmd_flags & SCF_FUA)) {
 663                         loff_t start = cmd->t_task_lba *
 664                                 dev->dev_attrib.block_size;
 665                         loff_t end;
 666
 667                         if (cmd->data_length)
 668                                 end = start + cmd->data_length - 1;
 669                         else
 670                                 end = LLONG_MAX;
 671
 672                         vfs_fsync_range(fd_dev->fd_file, start, end, 1);
 673                 }
 674
 675                 if (ret > 0 && cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 676                         ret = fd_do_rw(cmd, pfile, dev->prot_length,
 677                                        cmd->t_prot_sg, cmd->t_prot_nents,
 678                                        cmd->prot_length, 1);
 679                         if (ret < 0)
 680                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 681                 }
 682         }
 683
 684         if (ret < 0)
 685                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 686
 687         target_complete_cmd(cmd, SAM_STAT_GOOD);
 688         return 0;
 689 }
 690
 691 static sense_reason_t
 692 fd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 693               enum dma_data_direction data_direction)
 694 {
 695         struct se_device *dev = cmd->se_dev;
 696         struct fd_dev *fd_dev = FD_DEV(dev);
 697
 698         /*
 699          * We are currently limited by the number of iovecs (2048) per
 700          * single vfs_[writev,readv] call.
 701          */
 702         if (cmd->data_length > FD_MAX_BYTES) {
 703                 pr_err("FILEIO: Not able to process I/O of %u bytes due to"
 704                        "FD_MAX_BYTES: %u iovec count limitation\n",
 705                         cmd->data_length, FD_MAX_BYTES);
 706                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 707         }
 708
 709         if (fd_dev->fbd_flags & FDBD_HAS_ASYNC_IO)
 710                 return fd_execute_rw_aio(cmd, sgl, sgl_nents, data_direction);
 711         return fd_execute_rw_buffered(cmd, sgl, sgl_nents, data_direction);
 712 }
 713
 714 enum {
 715         Opt_fd_dev_name, Opt_fd_dev_size, Opt_fd_buffered_io,
 716         Opt_fd_async_io, Opt_err
 717 };
 718
 719 static match_table_t tokens = {
 720         {Opt_fd_dev_name, "fd_dev_name=%s"},
 721         {Opt_fd_dev_size, "fd_dev_size=%s"},
 722         {Opt_fd_buffered_io, "fd_buffered_io=%d"},
 723         {Opt_fd_async_io, "fd_async_io=%d"},
 724         {Opt_err, NULL}
 725 };
 726
 727 static ssize_t fd_set_configfs_dev_params(struct se_device *dev,
 728                 const char *page, ssize_t count)
 729 {
 730         struct fd_dev *fd_dev = FD_DEV(dev);
 731         char *orig, *ptr, *arg_p, *opts;
 732         substring_t args[MAX_OPT_ARGS];
 733         int ret = 0, arg, token;
 734
 735         opts = kstrdup(page, GFP_KERNEL);
 736         if (!opts)
 737                 return -ENOMEM;
 738
 739         orig = opts;
 740
 741         while ((ptr = strsep(&opts, ",\n")) != NULL) {
 742                 if (!*ptr)
 743                         continue;
 744
 745                 token = match_token(ptr, tokens, args);
 746                 switch (token) {
 747                 case Opt_fd_dev_name:
 748                         if (match_strlcpy(fd_dev->fd_dev_name, &args[0],
 749                                 FD_MAX_DEV_NAME) == 0) {
 750                                 ret = -EINVAL;
 751                                 break;
 752                         }
 753                         pr_debug("FILEIO: Referencing Path: %s\n",
 754                                         fd_dev->fd_dev_name);
 755                         fd_dev->fbd_flags |= FBDF_HAS_PATH;
 756                         break;
 757                 case Opt_fd_dev_size:
 758                         arg_p = match_strdup(&args[0]);
 759                         if (!arg_p) {
 760                                 ret = -ENOMEM;
 761                                 break;
 762                         }
 763                         ret = kstrtoull(arg_p, 0, &fd_dev->fd_dev_size);
 764                         kfree(arg_p);
 765                         if (ret < 0) {
 766                                 pr_err("kstrtoull() failed for"
 767                                                 " fd_dev_size=\n");
 768                                 goto out;
 769                         }
 770                         pr_debug("FILEIO: Referencing Size: %llu"
 771                                         " bytes\n", fd_dev->fd_dev_size);
 772                         fd_dev->fbd_flags |= FBDF_HAS_SIZE;
 773                         break;
 774                 case Opt_fd_buffered_io:
 775                         ret = match_int(args, &arg);
 776                         if (ret)
 777                                 goto out;
 778                         if (arg != 1) {
 779                                 pr_err("bogus fd_buffered_io=%d value\n", arg);
 780                                 ret = -EINVAL;
 781                                 goto out;
 782                         }
 783
 784                         pr_debug("FILEIO: Using buffered I/O"
 785                                 " operations for struct fd_dev\n");
 786
 787                         fd_dev->fbd_flags |= FDBD_HAS_BUFFERED_IO_WCE;
 788                         break;
 789                 case Opt_fd_async_io:
 790                         ret = match_int(args, &arg);
 791                         if (ret)
 792                                 goto out;
 793                         if (arg != 1) {
 794                                 pr_err("bogus fd_async_io=%d value\n", arg);
 795                                 ret = -EINVAL;
 796                                 goto out;
 797                         }
 798
 799                         pr_debug("FILEIO: Using async I/O"
 800                                 " operations for struct fd_dev\n");
 801
 802                         fd_dev->fbd_flags |= FDBD_HAS_ASYNC_IO;
 803                         break;
 804                 default:
 805                         break;
 806                 }
 807         }
 808
 809 out:
 810         kfree(orig);
 811         return (!ret) ? count : ret;
 812 }
 813
 814 static ssize_t fd_show_configfs_dev_params(struct se_device *dev, char *b)
 815 {
 816         struct fd_dev *fd_dev = FD_DEV(dev);
 817         ssize_t bl = 0;
 818
 819         bl = sprintf(b + bl, "TCM FILEIO ID: %u", fd_dev->fd_dev_id);
 820         bl += sprintf(b + bl, "        File: %s  Size: %llu  Mode: %s Async: %d\n",
 821                 fd_dev->fd_dev_name, fd_dev->fd_dev_size,
 822                 (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) ?
 823                 "Buffered-WCE" : "O_DSYNC",
 824                 !!(fd_dev->fbd_flags & FDBD_HAS_ASYNC_IO));
 825         return bl;
 826 }
 827
 828 static sector_t fd_get_blocks(struct se_device *dev)
 829 {
 830         struct fd_dev *fd_dev = FD_DEV(dev);
 831         struct file *f = fd_dev->fd_file;
 832         struct inode *i = f->f_mapping->host;
 833         unsigned long long dev_size;
 834         /*
 835          * When using a file that references an underlying struct block_device,
 836          * ensure dev_size is always based on the current inode size in order
 837          * to handle underlying block_device resize operations.
 838          */
 839         if (S_ISBLK(i->i_mode))
 840                 dev_size = i_size_read(i);
 841         else
 842                 dev_size = fd_dev->fd_dev_size;
 843
 844         return div_u64(dev_size - dev->dev_attrib.block_size,
 845                        dev->dev_attrib.block_size);
 846 }
 847
 848 static int fd_init_prot(struct se_device *dev)
 849 {
 850         struct fd_dev *fd_dev = FD_DEV(dev);
 851         struct file *prot_file, *file = fd_dev->fd_file;
 852         struct inode *inode;
 853         int ret, flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
 854         char buf[FD_MAX_DEV_PROT_NAME];
 855
 856         if (!file) {
 857                 pr_err("Unable to locate fd_dev->fd_file\n");
 858                 return -ENODEV;
 859         }
 860
 861         inode = file->f_mapping->host;
 862         if (S_ISBLK(inode->i_mode)) {
 863                 pr_err("FILEIO Protection emulation only supported on"
 864                        " !S_ISBLK\n");
 865                 return -ENOSYS;
 866         }
 867
 868         if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE)
 869                 flags &= ~O_DSYNC;
 870
 871         snprintf(buf, FD_MAX_DEV_PROT_NAME, "%s.protection",
 872                  fd_dev->fd_dev_name);
 873
 874         prot_file = filp_open(buf, flags, 0600);
 875         if (IS_ERR(prot_file)) {
 876                 pr_err("filp_open(%s) failed\n", buf);
 877                 ret = PTR_ERR(prot_file);
 878                 return ret;
 879         }
 880         fd_dev->fd_prot_file = prot_file;
 881
 882         return 0;
 883 }
 884
 885 static int fd_format_prot(struct se_device *dev)
 886 {
 887         unsigned char *buf;
 888         int unit_size = FDBD_FORMAT_UNIT_SIZE * dev->dev_attrib.block_size;
 889         int ret;
 890
 891         if (!dev->dev_attrib.pi_prot_type) {
 892                 pr_err("Unable to format_prot while pi_prot_type == 0\n");
 893                 return -ENODEV;
 894         }
 895
 896         buf = vzalloc(unit_size);
 897         if (!buf) {
 898                 pr_err("Unable to allocate FILEIO prot buf\n");
 899                 return -ENOMEM;
 900         }
 901
 902         pr_debug("Using FILEIO prot_length: %llu\n",
 903                  (unsigned long long)(dev->transport->get_blocks(dev) + 1) *
 904                                         dev->prot_length);
 905
 906         memset(buf, 0xff, unit_size);
 907         ret = fd_do_prot_fill(dev, 0, dev->transport->get_blocks(dev) + 1,
 908                               buf, unit_size);
 909         vfree(buf);
 910         return ret;
 911 }
 912
 913 static void fd_free_prot(struct se_device *dev)
 914 {
 915         struct fd_dev *fd_dev = FD_DEV(dev);
 916
 917         if (!fd_dev->fd_prot_file)
 918                 return;
 919
 920         filp_close(fd_dev->fd_prot_file, NULL);
 921         fd_dev->fd_prot_file = NULL;
 922 }
 923
 924 static struct sbc_ops fd_sbc_ops = {
 925         .execute_rw             = fd_execute_rw,
 926         .execute_sync_cache     = fd_execute_sync_cache,
 927         .execute_write_same     = fd_execute_write_same,
 928         .execute_unmap          = fd_execute_unmap,
 929 };
 930
 931 static sense_reason_t
 932 fd_parse_cdb(struct se_cmd *cmd)
 933 {
 934         return sbc_parse_cdb(cmd, &fd_sbc_ops);
 935 }
 936
 937 static const struct target_backend_ops fileio_ops = {
 938         .name                   = "fileio",
 939         .inquiry_prod           = "FILEIO",
 940         .inquiry_rev            = FD_VERSION,
 941         .owner                  = THIS_MODULE,
 942         .attach_hba             = fd_attach_hba,
 943         .detach_hba             = fd_detach_hba,
 944         .alloc_device           = fd_alloc_device,
 945         .configure_device       = fd_configure_device,
 946         .destroy_device         = fd_destroy_device,
 947         .free_device            = fd_free_device,
 948         .parse_cdb              = fd_parse_cdb,
 949         .set_configfs_dev_params = fd_set_configfs_dev_params,
 950         .show_configfs_dev_params = fd_show_configfs_dev_params,
 951         .get_device_type        = sbc_get_device_type,
 952         .get_blocks             = fd_get_blocks,
 953         .init_prot              = fd_init_prot,
 954         .format_prot            = fd_format_prot,
 955         .free_prot              = fd_free_prot,
 956         .tb_dev_attrib_attrs    = sbc_attrib_attrs,
 957 };
 958
 959 static int __init fileio_module_init(void)
 960 {
 961         return transport_backend_register(&fileio_ops);
 962 }
 963
 964 static void __exit fileio_module_exit(void)
 965 {
 966         target_backend_unregister(&fileio_ops);
 967 }
 968
 969 MODULE_DESCRIPTION("TCM FILEIO subsystem plugin");
 970 MODULE_AUTHOR("nab@Linux-iSCSI.org");
 971 MODULE_LICENSE("GPL");
 972
 973 module_init(fileio_module_init);
 974 module_exit(fileio_module_exit);