kernel/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 <scsi/scsi_proto.h>
  36 #include <asm/unaligned.h>
  37
  38 #include <target/target_core_base.h>
  39 #include <target/target_core_backend.h>
  40
  41 #include "target_core_file.h"
  42
  43 static inline struct fd_dev *FD_DEV(struct se_device *dev)
  44 {
  45         return container_of(dev, struct fd_dev, dev);
  46 }
  47
  48 static int fd_attach_hba(struct se_hba *hba, u32 host_id)
  49 {
  50         struct fd_host *fd_host;
  51
  52         fd_host = kzalloc(sizeof(struct fd_host), GFP_KERNEL);
  53         if (!fd_host) {
  54                 pr_err("Unable to allocate memory for struct fd_host\n");
  55                 return -ENOMEM;
  56         }
  57
  58         fd_host->fd_host_id = host_id;
  59
  60         hba->hba_ptr = fd_host;
  61
  62         pr_debug("CORE_HBA[%d] - TCM FILEIO HBA Driver %s on Generic"
  63                 " Target Core Stack %s\n", hba->hba_id, FD_VERSION,
  64                 TARGET_CORE_VERSION);
  65         pr_debug("CORE_HBA[%d] - Attached FILEIO HBA: %u to Generic\n",
  66                 hba->hba_id, fd_host->fd_host_id);
  67
  68         return 0;
  69 }
  70
  71 static void fd_detach_hba(struct se_hba *hba)
  72 {
  73         struct fd_host *fd_host = hba->hba_ptr;
  74
  75         pr_debug("CORE_HBA[%d] - Detached FILEIO HBA: %u from Generic"
  76                 " Target Core\n", hba->hba_id, fd_host->fd_host_id);
  77
  78         kfree(fd_host);
  79         hba->hba_ptr = NULL;
  80 }
  81
  82 static struct se_device *fd_alloc_device(struct se_hba *hba, const char *name)
  83 {
  84         struct fd_dev *fd_dev;
  85         struct fd_host *fd_host = hba->hba_ptr;
  86
  87         fd_dev = kzalloc(sizeof(struct fd_dev), GFP_KERNEL);
  88         if (!fd_dev) {
  89                 pr_err("Unable to allocate memory for struct fd_dev\n");
  90                 return NULL;
  91         }
  92
  93         fd_dev->fd_host = fd_host;
  94
  95         pr_debug("FILEIO: Allocated fd_dev for %p\n", name);
  96
  97         return &fd_dev->dev;
  98 }
  99
 100 static int fd_configure_device(struct se_device *dev)
 101 {
 102         struct fd_dev *fd_dev = FD_DEV(dev);
 103         struct fd_host *fd_host = dev->se_hba->hba_ptr;
 104         struct file *file;
 105         struct inode *inode = NULL;
 106         int flags, ret = -EINVAL;
 107
 108         if (!(fd_dev->fbd_flags & FBDF_HAS_PATH)) {
 109                 pr_err("Missing fd_dev_name=\n");
 110                 return -EINVAL;
 111         }
 112
 113         /*
 114          * Use O_DSYNC by default instead of O_SYNC to forgo syncing
 115          * of pure timestamp updates.
 116          */
 117         flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
 118
 119         /*
 120          * Optionally allow fd_buffered_io=1 to be enabled for people
 121          * who want use the fs buffer cache as an WriteCache mechanism.
 122          *
 123          * This means that in event of a hard failure, there is a risk
 124          * of silent data-loss if the SCSI client has *not* performed a
 125          * forced unit access (FUA) write, or issued SYNCHRONIZE_CACHE
 126          * to write-out the entire device cache.
 127          */
 128         if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
 129                 pr_debug("FILEIO: Disabling O_DSYNC, using buffered FILEIO\n");
 130                 flags &= ~O_DSYNC;
 131         }
 132
 133         file = filp_open(fd_dev->fd_dev_name, flags, 0600);
 134         if (IS_ERR(file)) {
 135                 pr_err("filp_open(%s) failed\n", fd_dev->fd_dev_name);
 136                 ret = PTR_ERR(file);
 137                 goto fail;
 138         }
 139         fd_dev->fd_file = file;
 140         /*
 141          * If using a block backend with this struct file, we extract
 142          * fd_dev->fd_[block,dev]_size from struct block_device.
 143          *
 144          * Otherwise, we use the passed fd_size= from configfs
 145          */
 146         inode = file->f_mapping->host;
 147         if (S_ISBLK(inode->i_mode)) {
 148                 struct request_queue *q = bdev_get_queue(inode->i_bdev);
 149                 unsigned long long dev_size;
 150
 151                 fd_dev->fd_block_size = bdev_logical_block_size(inode->i_bdev);
 152                 /*
 153                  * Determine the number of bytes from i_size_read() minus
 154                  * one (1) logical sector from underlying struct block_device
 155                  */
 156                 dev_size = (i_size_read(file->f_mapping->host) -
 157                                        fd_dev->fd_block_size);
 158
 159                 pr_debug("FILEIO: Using size: %llu bytes from struct"
 160                         " block_device blocks: %llu logical_block_size: %d\n",
 161                         dev_size, div_u64(dev_size, fd_dev->fd_block_size),
 162                         fd_dev->fd_block_size);
 163
 164                 if (target_configure_unmap_from_queue(&dev->dev_attrib, q,
 165                                                       fd_dev->fd_block_size))
 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         struct fd_dev *fd_dev = FD_DEV(dev);
 241
 242         if (fd_dev->fd_file) {
 243                 filp_close(fd_dev->fd_file, NULL);
 244                 fd_dev->fd_file = NULL;
 245         }
 246         call_rcu(&dev->rcu_head, fd_dev_call_rcu);
 247 }
 248
 249 static int fd_do_rw(struct se_cmd *cmd, struct file *fd,
 250                     u32 block_size, struct scatterlist *sgl,
 251                     u32 sgl_nents, u32 data_length, int is_write)
 252 {
 253         struct scatterlist *sg;
 254         struct iov_iter iter;
 255         struct bio_vec *bvec;
 256         ssize_t len = 0;
 257         loff_t pos = (cmd->t_task_lba * block_size);
 258         int ret = 0, i;
 259
 260         bvec = kcalloc(sgl_nents, sizeof(struct bio_vec), GFP_KERNEL);
 261         if (!bvec) {
 262                 pr_err("Unable to allocate fd_do_readv iov[]\n");
 263                 return -ENOMEM;
 264         }
 265
 266         for_each_sg(sgl, sg, sgl_nents, i) {
 267                 bvec[i].bv_page = sg_page(sg);
 268                 bvec[i].bv_len = sg->length;
 269                 bvec[i].bv_offset = sg->offset;
 270
 271                 len += sg->length;
 272         }
 273
 274         iov_iter_bvec(&iter, ITER_BVEC, bvec, sgl_nents, len);
 275         if (is_write)
 276                 ret = vfs_iter_write(fd, &iter, &pos);
 277         else
 278                 ret = vfs_iter_read(fd, &iter, &pos);
 279
 280         kfree(bvec);
 281
 282         if (is_write) {
 283                 if (ret < 0 || ret != data_length) {
 284                         pr_err("%s() write returned %d\n", __func__, ret);
 285                         return (ret < 0 ? ret : -EINVAL);
 286                 }
 287         } else {
 288                 /*
 289                  * Return zeros and GOOD status even if the READ did not return
 290                  * the expected virt_size for struct file w/o a backing struct
 291                  * block_device.
 292                  */
 293                 if (S_ISBLK(file_inode(fd)->i_mode)) {
 294                         if (ret < 0 || ret != data_length) {
 295                                 pr_err("%s() returned %d, expecting %u for "
 296                                                 "S_ISBLK\n", __func__, ret,
 297                                                 data_length);
 298                                 return (ret < 0 ? ret : -EINVAL);
 299                         }
 300                 } else {
 301                         if (ret < 0) {
 302                                 pr_err("%s() returned %d for non S_ISBLK\n",
 303                                                 __func__, ret);
 304                                 return ret;
 305                         }
 306                 }
 307         }
 308         return 1;
 309 }
 310
 311 static sense_reason_t
 312 fd_execute_sync_cache(struct se_cmd *cmd)
 313 {
 314         struct se_device *dev = cmd->se_dev;
 315         struct fd_dev *fd_dev = FD_DEV(dev);
 316         int immed = (cmd->t_task_cdb[1] & 0x2);
 317         loff_t start, end;
 318         int ret;
 319
 320         /*
 321          * If the Immediate bit is set, queue up the GOOD response
 322          * for this SYNCHRONIZE_CACHE op
 323          */
 324         if (immed)
 325                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 326
 327         /*
 328          * Determine if we will be flushing the entire device.
 329          */
 330         if (cmd->t_task_lba == 0 && cmd->data_length == 0) {
 331                 start = 0;
 332                 end = LLONG_MAX;
 333         } else {
 334                 start = cmd->t_task_lba * dev->dev_attrib.block_size;
 335                 if (cmd->data_length)
 336                         end = start + cmd->data_length - 1;
 337                 else
 338                         end = LLONG_MAX;
 339         }
 340
 341         ret = vfs_fsync_range(fd_dev->fd_file, start, end, 1);
 342         if (ret != 0)
 343                 pr_err("FILEIO: vfs_fsync_range() failed: %d\n", ret);
 344
 345         if (immed)
 346                 return 0;
 347
 348         if (ret)
 349                 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
 350         else
 351                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 352
 353         return 0;
 354 }
 355
 356 static sense_reason_t
 357 fd_execute_write_same(struct se_cmd *cmd)
 358 {
 359         struct se_device *se_dev = cmd->se_dev;
 360         struct fd_dev *fd_dev = FD_DEV(se_dev);
 361         loff_t pos = cmd->t_task_lba * se_dev->dev_attrib.block_size;
 362         sector_t nolb = sbc_get_write_same_sectors(cmd);
 363         struct iov_iter iter;
 364         struct bio_vec *bvec;
 365         unsigned int len = 0, i;
 366         ssize_t ret;
 367
 368         if (!nolb) {
 369                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 370                 return 0;
 371         }
 372         if (cmd->prot_op) {
 373                 pr_err("WRITE_SAME: Protection information with FILEIO"
 374                        " backends not supported\n");
 375                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 376         }
 377
 378         if (cmd->t_data_nents > 1 ||
 379             cmd->t_data_sg[0].length != cmd->se_dev->dev_attrib.block_size) {
 380                 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
 381                         " block_size: %u\n",
 382                         cmd->t_data_nents,
 383                         cmd->t_data_sg[0].length,
 384                         cmd->se_dev->dev_attrib.block_size);
 385                 return TCM_INVALID_CDB_FIELD;
 386         }
 387
 388         bvec = kcalloc(nolb, sizeof(struct bio_vec), GFP_KERNEL);
 389         if (!bvec)
 390                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 391
 392         for (i = 0; i < nolb; i++) {
 393                 bvec[i].bv_page = sg_page(&cmd->t_data_sg[0]);
 394                 bvec[i].bv_len = cmd->t_data_sg[0].length;
 395                 bvec[i].bv_offset = cmd->t_data_sg[0].offset;
 396
 397                 len += se_dev->dev_attrib.block_size;
 398         }
 399
 400         iov_iter_bvec(&iter, ITER_BVEC, bvec, nolb, len);
 401         ret = vfs_iter_write(fd_dev->fd_file, &iter, &pos);
 402
 403         kfree(bvec);
 404         if (ret < 0 || ret != len) {
 405                 pr_err("vfs_iter_write() returned %zd for write same\n", ret);
 406                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 407         }
 408
 409         target_complete_cmd(cmd, SAM_STAT_GOOD);
 410         return 0;
 411 }
 412
 413 static int
 414 fd_do_prot_fill(struct se_device *se_dev, sector_t lba, sector_t nolb,
 415                 void *buf, size_t bufsize)
 416 {
 417         struct fd_dev *fd_dev = FD_DEV(se_dev);
 418         struct file *prot_fd = fd_dev->fd_prot_file;
 419         sector_t prot_length, prot;
 420         loff_t pos = lba * se_dev->prot_length;
 421
 422         if (!prot_fd) {
 423                 pr_err("Unable to locate fd_dev->fd_prot_file\n");
 424                 return -ENODEV;
 425         }
 426
 427         prot_length = nolb * se_dev->prot_length;
 428
 429         for (prot = 0; prot < prot_length;) {
 430                 sector_t len = min_t(sector_t, bufsize, prot_length - prot);
 431                 ssize_t ret = kernel_write(prot_fd, buf, len, pos + prot);
 432
 433                 if (ret != len) {
 434                         pr_err("vfs_write to prot file failed: %zd\n", ret);
 435                         return ret < 0 ? ret : -ENODEV;
 436                 }
 437                 prot += ret;
 438         }
 439
 440         return 0;
 441 }
 442
 443 static int
 444 fd_do_prot_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
 445 {
 446         void *buf;
 447         int rc;
 448
 449         buf = (void *)__get_free_page(GFP_KERNEL);
 450         if (!buf) {
 451                 pr_err("Unable to allocate FILEIO prot buf\n");
 452                 return -ENOMEM;
 453         }
 454         memset(buf, 0xff, PAGE_SIZE);
 455
 456         rc = fd_do_prot_fill(cmd->se_dev, lba, nolb, buf, PAGE_SIZE);
 457
 458         free_page((unsigned long)buf);
 459
 460         return rc;
 461 }
 462
 463 static sense_reason_t
 464 fd_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
 465 {
 466         struct file *file = FD_DEV(cmd->se_dev)->fd_file;
 467         struct inode *inode = file->f_mapping->host;
 468         int ret;
 469
 470         if (cmd->se_dev->dev_attrib.pi_prot_type) {
 471                 ret = fd_do_prot_unmap(cmd, lba, nolb);
 472                 if (ret)
 473                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 474         }
 475
 476         if (S_ISBLK(inode->i_mode)) {
 477                 /* The backend is block device, use discard */
 478                 struct block_device *bdev = inode->i_bdev;
 479                 struct se_device *dev = cmd->se_dev;
 480
 481                 ret = blkdev_issue_discard(bdev,
 482                                            target_to_linux_sector(dev, lba),
 483                                            target_to_linux_sector(dev,  nolb),
 484                                            GFP_KERNEL, 0);
 485                 if (ret < 0) {
 486                         pr_warn("FILEIO: blkdev_issue_discard() failed: %d\n",
 487                                 ret);
 488                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 489                 }
 490         } else {
 491                 /* The backend is normal file, use fallocate */
 492                 struct se_device *se_dev = cmd->se_dev;
 493                 loff_t pos = lba * se_dev->dev_attrib.block_size;
 494                 unsigned int len = nolb * se_dev->dev_attrib.block_size;
 495                 int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
 496
 497                 if (!file->f_op->fallocate)
 498                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 499
 500                 ret = file->f_op->fallocate(file, mode, pos, len);
 501                 if (ret < 0) {
 502                         pr_warn("FILEIO: fallocate() failed: %d\n", ret);
 503                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 504                 }
 505         }
 506
 507         return 0;
 508 }
 509
 510 static sense_reason_t
 511 fd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 512               enum dma_data_direction data_direction)
 513 {
 514         struct se_device *dev = cmd->se_dev;
 515         struct fd_dev *fd_dev = FD_DEV(dev);
 516         struct file *file = fd_dev->fd_file;
 517         struct file *pfile = fd_dev->fd_prot_file;
 518         sense_reason_t rc;
 519         int ret = 0;
 520         /*
 521          * We are currently limited by the number of iovecs (2048) per
 522          * single vfs_[writev,readv] call.
 523          */
 524         if (cmd->data_length > FD_MAX_BYTES) {
 525                 pr_err("FILEIO: Not able to process I/O of %u bytes due to"
 526                        "FD_MAX_BYTES: %u iovec count limitiation\n",
 527                         cmd->data_length, FD_MAX_BYTES);
 528                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 529         }
 530         /*
 531          * Call vectorized fileio functions to map struct scatterlist
 532          * physical memory addresses to struct iovec virtual memory.
 533          */
 534         if (data_direction == DMA_FROM_DEVICE) {
 535                 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 536                         ret = fd_do_rw(cmd, pfile, dev->prot_length,
 537                                        cmd->t_prot_sg, cmd->t_prot_nents,
 538                                        cmd->prot_length, 0);
 539                         if (ret < 0)
 540                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 541                 }
 542
 543                 ret = fd_do_rw(cmd, file, dev->dev_attrib.block_size,
 544                                sgl, sgl_nents, cmd->data_length, 0);
 545
 546                 if (ret > 0 && cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 547                         u32 sectors = cmd->data_length >>
 548                                         ilog2(dev->dev_attrib.block_size);
 549
 550                         rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors,
 551                                             0, cmd->t_prot_sg, 0);
 552                         if (rc)
 553                                 return rc;
 554                 }
 555         } else {
 556                 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 557                         u32 sectors = cmd->data_length >>
 558                                         ilog2(dev->dev_attrib.block_size);
 559
 560                         rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors,
 561                                             0, cmd->t_prot_sg, 0);
 562                         if (rc)
 563                                 return rc;
 564                 }
 565
 566                 ret = fd_do_rw(cmd, file, dev->dev_attrib.block_size,
 567                                sgl, sgl_nents, cmd->data_length, 1);
 568                 /*
 569                  * Perform implicit vfs_fsync_range() for fd_do_writev() ops
 570                  * for SCSI WRITEs with Forced Unit Access (FUA) set.
 571                  * Allow this to happen independent of WCE=0 setting.
 572                  */
 573                 if (ret > 0 && (cmd->se_cmd_flags & SCF_FUA)) {
 574                         loff_t start = cmd->t_task_lba *
 575                                 dev->dev_attrib.block_size;
 576                         loff_t end;
 577
 578                         if (cmd->data_length)
 579                                 end = start + cmd->data_length - 1;
 580                         else
 581                                 end = LLONG_MAX;
 582
 583                         vfs_fsync_range(fd_dev->fd_file, start, end, 1);
 584                 }
 585
 586                 if (ret > 0 && cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 587                         ret = fd_do_rw(cmd, pfile, dev->prot_length,
 588                                        cmd->t_prot_sg, cmd->t_prot_nents,
 589                                        cmd->prot_length, 1);
 590                         if (ret < 0)
 591                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 592                 }
 593         }
 594
 595         if (ret < 0)
 596                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 597
 598         if (ret)
 599                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 600         return 0;
 601 }
 602
 603 enum {
 604         Opt_fd_dev_name, Opt_fd_dev_size, Opt_fd_buffered_io, Opt_err
 605 };
 606
 607 static match_table_t tokens = {
 608         {Opt_fd_dev_name, "fd_dev_name=%s"},
 609         {Opt_fd_dev_size, "fd_dev_size=%s"},
 610         {Opt_fd_buffered_io, "fd_buffered_io=%d"},
 611         {Opt_err, NULL}
 612 };
 613
 614 static ssize_t fd_set_configfs_dev_params(struct se_device *dev,
 615                 const char *page, ssize_t count)
 616 {
 617         struct fd_dev *fd_dev = FD_DEV(dev);
 618         char *orig, *ptr, *arg_p, *opts;
 619         substring_t args[MAX_OPT_ARGS];
 620         int ret = 0, arg, token;
 621
 622         opts = kstrdup(page, GFP_KERNEL);
 623         if (!opts)
 624                 return -ENOMEM;
 625
 626         orig = opts;
 627
 628         while ((ptr = strsep(&opts, ",\n")) != NULL) {
 629                 if (!*ptr)
 630                         continue;
 631
 632                 token = match_token(ptr, tokens, args);
 633                 switch (token) {
 634                 case Opt_fd_dev_name:
 635                         if (match_strlcpy(fd_dev->fd_dev_name, &args[0],
 636                                 FD_MAX_DEV_NAME) == 0) {
 637                                 ret = -EINVAL;
 638                                 break;
 639                         }
 640                         pr_debug("FILEIO: Referencing Path: %s\n",
 641                                         fd_dev->fd_dev_name);
 642                         fd_dev->fbd_flags |= FBDF_HAS_PATH;
 643                         break;
 644                 case Opt_fd_dev_size:
 645                         arg_p = match_strdup(&args[0]);
 646                         if (!arg_p) {
 647                                 ret = -ENOMEM;
 648                                 break;
 649                         }
 650                         ret = kstrtoull(arg_p, 0, &fd_dev->fd_dev_size);
 651                         kfree(arg_p);
 652                         if (ret < 0) {
 653                                 pr_err("kstrtoull() failed for"
 654                                                 " fd_dev_size=\n");
 655                                 goto out;
 656                         }
 657                         pr_debug("FILEIO: Referencing Size: %llu"
 658                                         " bytes\n", fd_dev->fd_dev_size);
 659                         fd_dev->fbd_flags |= FBDF_HAS_SIZE;
 660                         break;
 661                 case Opt_fd_buffered_io:
 662                         ret = match_int(args, &arg);
 663                         if (ret)
 664                                 goto out;
 665                         if (arg != 1) {
 666                                 pr_err("bogus fd_buffered_io=%d value\n", arg);
 667                                 ret = -EINVAL;
 668                                 goto out;
 669                         }
 670
 671                         pr_debug("FILEIO: Using buffered I/O"
 672                                 " operations for struct fd_dev\n");
 673
 674                         fd_dev->fbd_flags |= FDBD_HAS_BUFFERED_IO_WCE;
 675                         break;
 676                 default:
 677                         break;
 678                 }
 679         }
 680
 681 out:
 682         kfree(orig);
 683         return (!ret) ? count : ret;
 684 }
 685
 686 static ssize_t fd_show_configfs_dev_params(struct se_device *dev, char *b)
 687 {
 688         struct fd_dev *fd_dev = FD_DEV(dev);
 689         ssize_t bl = 0;
 690
 691         bl = sprintf(b + bl, "TCM FILEIO ID: %u", fd_dev->fd_dev_id);
 692         bl += sprintf(b + bl, "        File: %s  Size: %llu  Mode: %s\n",
 693                 fd_dev->fd_dev_name, fd_dev->fd_dev_size,
 694                 (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) ?
 695                 "Buffered-WCE" : "O_DSYNC");
 696         return bl;
 697 }
 698
 699 static sector_t fd_get_blocks(struct se_device *dev)
 700 {
 701         struct fd_dev *fd_dev = FD_DEV(dev);
 702         struct file *f = fd_dev->fd_file;
 703         struct inode *i = f->f_mapping->host;
 704         unsigned long long dev_size;
 705         /*
 706          * When using a file that references an underlying struct block_device,
 707          * ensure dev_size is always based on the current inode size in order
 708          * to handle underlying block_device resize operations.
 709          */
 710         if (S_ISBLK(i->i_mode))
 711                 dev_size = i_size_read(i);
 712         else
 713                 dev_size = fd_dev->fd_dev_size;
 714
 715         return div_u64(dev_size - dev->dev_attrib.block_size,
 716                        dev->dev_attrib.block_size);
 717 }
 718
 719 static int fd_init_prot(struct se_device *dev)
 720 {
 721         struct fd_dev *fd_dev = FD_DEV(dev);
 722         struct file *prot_file, *file = fd_dev->fd_file;
 723         struct inode *inode;
 724         int ret, flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
 725         char buf[FD_MAX_DEV_PROT_NAME];
 726
 727         if (!file) {
 728                 pr_err("Unable to locate fd_dev->fd_file\n");
 729                 return -ENODEV;
 730         }
 731
 732         inode = file->f_mapping->host;
 733         if (S_ISBLK(inode->i_mode)) {
 734                 pr_err("FILEIO Protection emulation only supported on"
 735                        " !S_ISBLK\n");
 736                 return -ENOSYS;
 737         }
 738
 739         if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE)
 740                 flags &= ~O_DSYNC;
 741
 742         snprintf(buf, FD_MAX_DEV_PROT_NAME, "%s.protection",
 743                  fd_dev->fd_dev_name);
 744
 745         prot_file = filp_open(buf, flags, 0600);
 746         if (IS_ERR(prot_file)) {
 747                 pr_err("filp_open(%s) failed\n", buf);
 748                 ret = PTR_ERR(prot_file);
 749                 return ret;
 750         }
 751         fd_dev->fd_prot_file = prot_file;
 752
 753         return 0;
 754 }
 755
 756 static int fd_format_prot(struct se_device *dev)
 757 {
 758         unsigned char *buf;
 759         int unit_size = FDBD_FORMAT_UNIT_SIZE * dev->dev_attrib.block_size;
 760         int ret;
 761
 762         if (!dev->dev_attrib.pi_prot_type) {
 763                 pr_err("Unable to format_prot while pi_prot_type == 0\n");
 764                 return -ENODEV;
 765         }
 766
 767         buf = vzalloc(unit_size);
 768         if (!buf) {
 769                 pr_err("Unable to allocate FILEIO prot buf\n");
 770                 return -ENOMEM;
 771         }
 772
 773         pr_debug("Using FILEIO prot_length: %llu\n",
 774                  (unsigned long long)(dev->transport->get_blocks(dev) + 1) *
 775                                         dev->prot_length);
 776
 777         memset(buf, 0xff, unit_size);
 778         ret = fd_do_prot_fill(dev, 0, dev->transport->get_blocks(dev) + 1,
 779                               buf, unit_size);
 780         vfree(buf);
 781         return ret;
 782 }
 783
 784 static void fd_free_prot(struct se_device *dev)
 785 {
 786         struct fd_dev *fd_dev = FD_DEV(dev);
 787
 788         if (!fd_dev->fd_prot_file)
 789                 return;
 790
 791         filp_close(fd_dev->fd_prot_file, NULL);
 792         fd_dev->fd_prot_file = NULL;
 793 }
 794
 795 static struct sbc_ops fd_sbc_ops = {
 796         .execute_rw             = fd_execute_rw,
 797         .execute_sync_cache     = fd_execute_sync_cache,
 798         .execute_write_same     = fd_execute_write_same,
 799         .execute_unmap          = fd_execute_unmap,
 800 };
 801
 802 static sense_reason_t
 803 fd_parse_cdb(struct se_cmd *cmd)
 804 {
 805         return sbc_parse_cdb(cmd, &fd_sbc_ops);
 806 }
 807
 808 static const struct target_backend_ops fileio_ops = {
 809         .name                   = "fileio",
 810         .inquiry_prod           = "FILEIO",
 811         .inquiry_rev            = FD_VERSION,
 812         .owner                  = THIS_MODULE,
 813         .attach_hba             = fd_attach_hba,
 814         .detach_hba             = fd_detach_hba,
 815         .alloc_device           = fd_alloc_device,
 816         .configure_device       = fd_configure_device,
 817         .free_device            = fd_free_device,
 818         .parse_cdb              = fd_parse_cdb,
 819         .set_configfs_dev_params = fd_set_configfs_dev_params,
 820         .show_configfs_dev_params = fd_show_configfs_dev_params,
 821         .get_device_type        = sbc_get_device_type,
 822         .get_blocks             = fd_get_blocks,
 823         .init_prot              = fd_init_prot,
 824         .format_prot            = fd_format_prot,
 825         .free_prot              = fd_free_prot,
 826         .tb_dev_attrib_attrs    = sbc_attrib_attrs,
 827 };
 828
 829 static int __init fileio_module_init(void)
 830 {
 831         return transport_backend_register(&fileio_ops);
 832 }
 833
 834 static void __exit fileio_module_exit(void)
 835 {
 836         target_backend_unregister(&fileio_ops);
 837 }
 838
 839 MODULE_DESCRIPTION("TCM FILEIO subsystem plugin");
 840 MODULE_AUTHOR("nab@Linux-iSCSI.org");
 841 MODULE_LICENSE("GPL");
 842
 843 module_init(fileio_module_init);
 844 module_exit(fileio_module_exit);