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/falloc.h>
  34 #include <scsi/scsi.h>
  35 #include <scsi/scsi_host.h>
  36 #include <asm/unaligned.h>
  37
  38 #include <target/target_core_base.h>
  39 #include <target/target_core_backend.h>
  40 #include <target/target_core_backend_configfs.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 /*      fd_attach_hba(): (Part of se_subsystem_api_t template)
  50  *
  51  *
  52  */
  53 static int fd_attach_hba(struct se_hba *hba, u32 host_id)
  54 {
  55         struct fd_host *fd_host;
  56
  57         fd_host = kzalloc(sizeof(struct fd_host), GFP_KERNEL);
  58         if (!fd_host) {
  59                 pr_err("Unable to allocate memory for struct fd_host\n");
  60                 return -ENOMEM;
  61         }
  62
  63         fd_host->fd_host_id = host_id;
  64
  65         hba->hba_ptr = fd_host;
  66
  67         pr_debug("CORE_HBA[%d] - TCM FILEIO HBA Driver %s on Generic"
  68                 " Target Core Stack %s\n", hba->hba_id, FD_VERSION,
  69                 TARGET_CORE_MOD_VERSION);
  70         pr_debug("CORE_HBA[%d] - Attached FILEIO HBA: %u to Generic\n",
  71                 hba->hba_id, fd_host->fd_host_id);
  72
  73         return 0;
  74 }
  75
  76 static void fd_detach_hba(struct se_hba *hba)
  77 {
  78         struct fd_host *fd_host = hba->hba_ptr;
  79
  80         pr_debug("CORE_HBA[%d] - Detached FILEIO HBA: %u from Generic"
  81                 " Target Core\n", hba->hba_id, fd_host->fd_host_id);
  82
  83         kfree(fd_host);
  84         hba->hba_ptr = NULL;
  85 }
  86
  87 static struct se_device *fd_alloc_device(struct se_hba *hba, const char *name)
  88 {
  89         struct fd_dev *fd_dev;
  90         struct fd_host *fd_host = hba->hba_ptr;
  91
  92         fd_dev = kzalloc(sizeof(struct fd_dev), GFP_KERNEL);
  93         if (!fd_dev) {
  94                 pr_err("Unable to allocate memory for struct fd_dev\n");
  95                 return NULL;
  96         }
  97
  98         fd_dev->fd_host = fd_host;
  99
 100         pr_debug("FILEIO: Allocated fd_dev for %p\n", name);
 101
 102         return &fd_dev->dev;
 103 }
 104
 105 static int fd_configure_device(struct se_device *dev)
 106 {
 107         struct fd_dev *fd_dev = FD_DEV(dev);
 108         struct fd_host *fd_host = dev->se_hba->hba_ptr;
 109         struct file *file;
 110         struct inode *inode = NULL;
 111         int flags, ret = -EINVAL;
 112
 113         if (!(fd_dev->fbd_flags & FBDF_HAS_PATH)) {
 114                 pr_err("Missing fd_dev_name=\n");
 115                 return -EINVAL;
 116         }
 117
 118         /*
 119          * Use O_DSYNC by default instead of O_SYNC to forgo syncing
 120          * of pure timestamp updates.
 121          */
 122         flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
 123
 124         /*
 125          * Optionally allow fd_buffered_io=1 to be enabled for people
 126          * who want use the fs buffer cache as an WriteCache mechanism.
 127          *
 128          * This means that in event of a hard failure, there is a risk
 129          * of silent data-loss if the SCSI client has *not* performed a
 130          * forced unit access (FUA) write, or issued SYNCHRONIZE_CACHE
 131          * to write-out the entire device cache.
 132          */
 133         if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
 134                 pr_debug("FILEIO: Disabling O_DSYNC, using buffered FILEIO\n");
 135                 flags &= ~O_DSYNC;
 136         }
 137
 138         file = filp_open(fd_dev->fd_dev_name, flags, 0600);
 139         if (IS_ERR(file)) {
 140                 pr_err("filp_open(%s) failed\n", fd_dev->fd_dev_name);
 141                 ret = PTR_ERR(file);
 142                 goto fail;
 143         }
 144         fd_dev->fd_file = file;
 145         /*
 146          * If using a block backend with this struct file, we extract
 147          * fd_dev->fd_[block,dev]_size from struct block_device.
 148          *
 149          * Otherwise, we use the passed fd_size= from configfs
 150          */
 151         inode = file->f_mapping->host;
 152         if (S_ISBLK(inode->i_mode)) {
 153                 struct request_queue *q = bdev_get_queue(inode->i_bdev);
 154                 unsigned long long dev_size;
 155
 156                 fd_dev->fd_block_size = bdev_logical_block_size(inode->i_bdev);
 157                 /*
 158                  * Determine the number of bytes from i_size_read() minus
 159                  * one (1) logical sector from underlying struct block_device
 160                  */
 161                 dev_size = (i_size_read(file->f_mapping->host) -
 162                                        fd_dev->fd_block_size);
 163
 164                 pr_debug("FILEIO: Using size: %llu bytes from struct"
 165                         " block_device blocks: %llu logical_block_size: %d\n",
 166                         dev_size, div_u64(dev_size, fd_dev->fd_block_size),
 167                         fd_dev->fd_block_size);
 168                 /*
 169                  * Check if the underlying struct block_device request_queue supports
 170                  * the QUEUE_FLAG_DISCARD bit for UNMAP/WRITE_SAME in SCSI + TRIM
 171                  * in ATA and we need to set TPE=1
 172                  */
 173                 if (blk_queue_discard(q)) {
 174                         dev->dev_attrib.max_unmap_lba_count =
 175                                 q->limits.max_discard_sectors;
 176                         /*
 177                          * Currently hardcoded to 1 in Linux/SCSI code..
 178                          */
 179                         dev->dev_attrib.max_unmap_block_desc_count = 1;
 180                         dev->dev_attrib.unmap_granularity =
 181                                 q->limits.discard_granularity >> 9;
 182                         dev->dev_attrib.unmap_granularity_alignment =
 183                                 q->limits.discard_alignment;
 184                         pr_debug("IFILE: BLOCK Discard support available,"
 185                                         " disabled by default\n");
 186                 }
 187                 /*
 188                  * Enable write same emulation for IBLOCK and use 0xFFFF as
 189                  * the smaller WRITE_SAME(10) only has a two-byte block count.
 190                  */
 191                 dev->dev_attrib.max_write_same_len = 0xFFFF;
 192
 193                 if (blk_queue_nonrot(q))
 194                         dev->dev_attrib.is_nonrot = 1;
 195         } else {
 196                 if (!(fd_dev->fbd_flags & FBDF_HAS_SIZE)) {
 197                         pr_err("FILEIO: Missing fd_dev_size="
 198                                 " parameter, and no backing struct"
 199                                 " block_device\n");
 200                         goto fail;
 201                 }
 202
 203                 fd_dev->fd_block_size = FD_BLOCKSIZE;
 204                 /*
 205                  * Limit UNMAP emulation to 8k Number of LBAs (NoLB)
 206                  */
 207                 dev->dev_attrib.max_unmap_lba_count = 0x2000;
 208                 /*
 209                  * Currently hardcoded to 1 in Linux/SCSI code..
 210                  */
 211                 dev->dev_attrib.max_unmap_block_desc_count = 1;
 212                 dev->dev_attrib.unmap_granularity = 1;
 213                 dev->dev_attrib.unmap_granularity_alignment = 0;
 214
 215                 /*
 216                  * Limit WRITE_SAME w/ UNMAP=0 emulation to 8k Number of LBAs (NoLB)
 217                  * based upon struct iovec limit for vfs_writev()
 218                  */
 219                 dev->dev_attrib.max_write_same_len = 0x1000;
 220         }
 221
 222         dev->dev_attrib.hw_block_size = fd_dev->fd_block_size;
 223         dev->dev_attrib.max_bytes_per_io = FD_MAX_BYTES;
 224         dev->dev_attrib.hw_max_sectors = FD_MAX_BYTES / fd_dev->fd_block_size;
 225         dev->dev_attrib.hw_queue_depth = FD_MAX_DEVICE_QUEUE_DEPTH;
 226
 227         if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
 228                 pr_debug("FILEIO: Forcing setting of emulate_write_cache=1"
 229                         " with FDBD_HAS_BUFFERED_IO_WCE\n");
 230                 dev->dev_attrib.emulate_write_cache = 1;
 231         }
 232
 233         fd_dev->fd_dev_id = fd_host->fd_host_dev_id_count++;
 234         fd_dev->fd_queue_depth = dev->queue_depth;
 235
 236         pr_debug("CORE_FILE[%u] - Added TCM FILEIO Device ID: %u at %s,"
 237                 " %llu total bytes\n", fd_host->fd_host_id, fd_dev->fd_dev_id,
 238                         fd_dev->fd_dev_name, fd_dev->fd_dev_size);
 239
 240         return 0;
 241 fail:
 242         if (fd_dev->fd_file) {
 243                 filp_close(fd_dev->fd_file, NULL);
 244                 fd_dev->fd_file = NULL;
 245         }
 246         return ret;
 247 }
 248
 249 static void fd_free_device(struct se_device *dev)
 250 {
 251         struct fd_dev *fd_dev = FD_DEV(dev);
 252
 253         if (fd_dev->fd_file) {
 254                 filp_close(fd_dev->fd_file, NULL);
 255                 fd_dev->fd_file = NULL;
 256         }
 257
 258         kfree(fd_dev);
 259 }
 260
 261 static int fd_do_prot_rw(struct se_cmd *cmd, struct fd_prot *fd_prot,
 262                          int is_write)
 263 {
 264         struct se_device *se_dev = cmd->se_dev;
 265         struct fd_dev *dev = FD_DEV(se_dev);
 266         struct file *prot_fd = dev->fd_prot_file;
 267         struct scatterlist *sg;
 268         loff_t pos = (cmd->t_task_lba * se_dev->prot_length);
 269         unsigned char *buf;
 270         u32 prot_size, len, size;
 271         int rc, ret = 1, i;
 272
 273         prot_size = (cmd->data_length / se_dev->dev_attrib.block_size) *
 274                      se_dev->prot_length;
 275
 276         if (!is_write) {
 277                 fd_prot->prot_buf = vzalloc(prot_size);
 278                 if (!fd_prot->prot_buf) {
 279                         pr_err("Unable to allocate fd_prot->prot_buf\n");
 280                         return -ENOMEM;
 281                 }
 282                 buf = fd_prot->prot_buf;
 283
 284                 fd_prot->prot_sg_nents = cmd->t_prot_nents;
 285                 fd_prot->prot_sg = kzalloc(sizeof(struct scatterlist) *
 286                                            fd_prot->prot_sg_nents, GFP_KERNEL);
 287                 if (!fd_prot->prot_sg) {
 288                         pr_err("Unable to allocate fd_prot->prot_sg\n");
 289                         vfree(fd_prot->prot_buf);
 290                         return -ENOMEM;
 291                 }
 292                 size = prot_size;
 293
 294                 for_each_sg(fd_prot->prot_sg, sg, fd_prot->prot_sg_nents, i) {
 295
 296                         len = min_t(u32, PAGE_SIZE, size);
 297                         sg_set_buf(sg, buf, len);
 298                         size -= len;
 299                         buf += len;
 300                 }
 301         }
 302
 303         if (is_write) {
 304                 rc = kernel_write(prot_fd, fd_prot->prot_buf, prot_size, pos);
 305                 if (rc < 0 || prot_size != rc) {
 306                         pr_err("kernel_write() for fd_do_prot_rw failed:"
 307                                " %d\n", rc);
 308                         ret = -EINVAL;
 309                 }
 310         } else {
 311                 rc = kernel_read(prot_fd, pos, fd_prot->prot_buf, prot_size);
 312                 if (rc < 0) {
 313                         pr_err("kernel_read() for fd_do_prot_rw failed:"
 314                                " %d\n", rc);
 315                         ret = -EINVAL;
 316                 }
 317         }
 318
 319         if (is_write || ret < 0) {
 320                 kfree(fd_prot->prot_sg);
 321                 vfree(fd_prot->prot_buf);
 322         }
 323
 324         return ret;
 325 }
 326
 327 static int fd_do_rw(struct se_cmd *cmd, struct scatterlist *sgl,
 328                 u32 sgl_nents, int is_write)
 329 {
 330         struct se_device *se_dev = cmd->se_dev;
 331         struct fd_dev *dev = FD_DEV(se_dev);
 332         struct file *fd = dev->fd_file;
 333         struct scatterlist *sg;
 334         struct iov_iter iter;
 335         struct bio_vec *bvec;
 336         ssize_t len = 0;
 337         loff_t pos = (cmd->t_task_lba * se_dev->dev_attrib.block_size);
 338         int ret = 0, i;
 339
 340         bvec = kcalloc(sgl_nents, sizeof(struct bio_vec), GFP_KERNEL);
 341         if (!bvec) {
 342                 pr_err("Unable to allocate fd_do_readv iov[]\n");
 343                 return -ENOMEM;
 344         }
 345
 346         for_each_sg(sgl, sg, sgl_nents, i) {
 347                 bvec[i].bv_page = sg_page(sg);
 348                 bvec[i].bv_len = sg->length;
 349                 bvec[i].bv_offset = sg->offset;
 350
 351                 len += sg->length;
 352         }
 353
 354         iov_iter_bvec(&iter, ITER_BVEC, bvec, sgl_nents, len);
 355         if (is_write)
 356                 ret = vfs_iter_write(fd, &iter, &pos);
 357         else
 358                 ret = vfs_iter_read(fd, &iter, &pos);
 359
 360         kfree(bvec);
 361
 362         if (is_write) {
 363                 if (ret < 0 || ret != cmd->data_length) {
 364                         pr_err("%s() write returned %d\n", __func__, ret);
 365                         return (ret < 0 ? ret : -EINVAL);
 366                 }
 367         } else {
 368                 /*
 369                  * Return zeros and GOOD status even if the READ did not return
 370                  * the expected virt_size for struct file w/o a backing struct
 371                  * block_device.
 372                  */
 373                 if (S_ISBLK(file_inode(fd)->i_mode)) {
 374                         if (ret < 0 || ret != cmd->data_length) {
 375                                 pr_err("%s() returned %d, expecting %u for "
 376                                                 "S_ISBLK\n", __func__, ret,
 377                                                 cmd->data_length);
 378                                 return (ret < 0 ? ret : -EINVAL);
 379                         }
 380                 } else {
 381                         if (ret < 0) {
 382                                 pr_err("%s() returned %d for non S_ISBLK\n",
 383                                                 __func__, ret);
 384                                 return ret;
 385                         }
 386                 }
 387         }
 388         return 1;
 389 }
 390
 391 static sense_reason_t
 392 fd_execute_sync_cache(struct se_cmd *cmd)
 393 {
 394         struct se_device *dev = cmd->se_dev;
 395         struct fd_dev *fd_dev = FD_DEV(dev);
 396         int immed = (cmd->t_task_cdb[1] & 0x2);
 397         loff_t start, end;
 398         int ret;
 399
 400         /*
 401          * If the Immediate bit is set, queue up the GOOD response
 402          * for this SYNCHRONIZE_CACHE op
 403          */
 404         if (immed)
 405                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 406
 407         /*
 408          * Determine if we will be flushing the entire device.
 409          */
 410         if (cmd->t_task_lba == 0 && cmd->data_length == 0) {
 411                 start = 0;
 412                 end = LLONG_MAX;
 413         } else {
 414                 start = cmd->t_task_lba * dev->dev_attrib.block_size;
 415                 if (cmd->data_length)
 416                         end = start + cmd->data_length - 1;
 417                 else
 418                         end = LLONG_MAX;
 419         }
 420
 421         ret = vfs_fsync_range(fd_dev->fd_file, start, end, 1);
 422         if (ret != 0)
 423                 pr_err("FILEIO: vfs_fsync_range() failed: %d\n", ret);
 424
 425         if (immed)
 426                 return 0;
 427
 428         if (ret)
 429                 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
 430         else
 431                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 432
 433         return 0;
 434 }
 435
 436 static sense_reason_t
 437 fd_execute_write_same(struct se_cmd *cmd)
 438 {
 439         struct se_device *se_dev = cmd->se_dev;
 440         struct fd_dev *fd_dev = FD_DEV(se_dev);
 441         loff_t pos = cmd->t_task_lba * se_dev->dev_attrib.block_size;
 442         sector_t nolb = sbc_get_write_same_sectors(cmd);
 443         struct iov_iter iter;
 444         struct bio_vec *bvec;
 445         unsigned int len = 0, i;
 446         ssize_t ret;
 447
 448         if (!nolb) {
 449                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 450                 return 0;
 451         }
 452         if (cmd->prot_op) {
 453                 pr_err("WRITE_SAME: Protection information with FILEIO"
 454                        " backends not supported\n");
 455                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 456         }
 457
 458         if (cmd->t_data_nents > 1 ||
 459             cmd->t_data_sg[0].length != cmd->se_dev->dev_attrib.block_size) {
 460                 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
 461                         " block_size: %u\n",
 462                         cmd->t_data_nents,
 463                         cmd->t_data_sg[0].length,
 464                         cmd->se_dev->dev_attrib.block_size);
 465                 return TCM_INVALID_CDB_FIELD;
 466         }
 467
 468         bvec = kcalloc(nolb, sizeof(struct bio_vec), GFP_KERNEL);
 469         if (!bvec)
 470                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 471
 472         for (i = 0; i < nolb; i++) {
 473                 bvec[i].bv_page = sg_page(&cmd->t_data_sg[0]);
 474                 bvec[i].bv_len = cmd->t_data_sg[0].length;
 475                 bvec[i].bv_offset = cmd->t_data_sg[0].offset;
 476
 477                 len += se_dev->dev_attrib.block_size;
 478         }
 479
 480         iov_iter_bvec(&iter, ITER_BVEC, bvec, nolb, len);
 481         ret = vfs_iter_write(fd_dev->fd_file, &iter, &pos);
 482
 483         kfree(bvec);
 484         if (ret < 0 || ret != len) {
 485                 pr_err("vfs_iter_write() returned %zd for write same\n", ret);
 486                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 487         }
 488
 489         target_complete_cmd(cmd, SAM_STAT_GOOD);
 490         return 0;
 491 }
 492
 493 static sense_reason_t
 494 fd_do_unmap(struct se_cmd *cmd, void *priv, sector_t lba, sector_t nolb)
 495 {
 496         struct file *file = priv;
 497         struct inode *inode = file->f_mapping->host;
 498         int ret;
 499
 500         if (S_ISBLK(inode->i_mode)) {
 501                 /* The backend is block device, use discard */
 502                 struct block_device *bdev = inode->i_bdev;
 503
 504                 ret = blkdev_issue_discard(bdev, lba,
 505                                 nolb, GFP_KERNEL, 0);
 506                 if (ret < 0) {
 507                         pr_warn("FILEIO: blkdev_issue_discard() failed: %d\n",
 508                                 ret);
 509                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 510                 }
 511         } else {
 512                 /* The backend is normal file, use fallocate */
 513                 struct se_device *se_dev = cmd->se_dev;
 514                 loff_t pos = lba * se_dev->dev_attrib.block_size;
 515                 unsigned int len = nolb * se_dev->dev_attrib.block_size;
 516                 int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
 517
 518                 if (!file->f_op->fallocate)
 519                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 520
 521                 ret = file->f_op->fallocate(file, mode, pos, len);
 522                 if (ret < 0) {
 523                         pr_warn("FILEIO: fallocate() failed: %d\n", ret);
 524                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 525                 }
 526         }
 527
 528         return 0;
 529 }
 530
 531 static sense_reason_t
 532 fd_execute_write_same_unmap(struct se_cmd *cmd)
 533 {
 534         struct se_device *se_dev = cmd->se_dev;
 535         struct fd_dev *fd_dev = FD_DEV(se_dev);
 536         struct file *file = fd_dev->fd_file;
 537         sector_t lba = cmd->t_task_lba;
 538         sector_t nolb = sbc_get_write_same_sectors(cmd);
 539         sense_reason_t ret;
 540
 541         if (!nolb) {
 542                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 543                 return 0;
 544         }
 545
 546         ret = fd_do_unmap(cmd, file, lba, nolb);
 547         if (ret)
 548                 return ret;
 549
 550         target_complete_cmd(cmd, GOOD);
 551         return 0;
 552 }
 553
 554 static sense_reason_t
 555 fd_execute_unmap(struct se_cmd *cmd)
 556 {
 557         struct file *file = FD_DEV(cmd->se_dev)->fd_file;
 558
 559         return sbc_execute_unmap(cmd, fd_do_unmap, file);
 560 }
 561
 562 static sense_reason_t
 563 fd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 564               enum dma_data_direction data_direction)
 565 {
 566         struct se_device *dev = cmd->se_dev;
 567         struct fd_prot fd_prot;
 568         sense_reason_t rc;
 569         int ret = 0;
 570         /*
 571          * We are currently limited by the number of iovecs (2048) per
 572          * single vfs_[writev,readv] call.
 573          */
 574         if (cmd->data_length > FD_MAX_BYTES) {
 575                 pr_err("FILEIO: Not able to process I/O of %u bytes due to"
 576                        "FD_MAX_BYTES: %u iovec count limitiation\n",
 577                         cmd->data_length, FD_MAX_BYTES);
 578                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 579         }
 580         /*
 581          * Call vectorized fileio functions to map struct scatterlist
 582          * physical memory addresses to struct iovec virtual memory.
 583          */
 584         if (data_direction == DMA_FROM_DEVICE) {
 585                 memset(&fd_prot, 0, sizeof(struct fd_prot));
 586
 587                 if (cmd->prot_type) {
 588                         ret = fd_do_prot_rw(cmd, &fd_prot, false);
 589                         if (ret < 0)
 590                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 591                 }
 592
 593                 ret = fd_do_rw(cmd, sgl, sgl_nents, 0);
 594
 595                 if (ret > 0 && cmd->prot_type) {
 596                         u32 sectors = cmd->data_length / dev->dev_attrib.block_size;
 597
 598                         rc = sbc_dif_verify_read(cmd, cmd->t_task_lba, sectors,
 599                                                  0, fd_prot.prot_sg, 0);
 600                         if (rc) {
 601                                 kfree(fd_prot.prot_sg);
 602                                 vfree(fd_prot.prot_buf);
 603                                 return rc;
 604                         }
 605                         kfree(fd_prot.prot_sg);
 606                         vfree(fd_prot.prot_buf);
 607                 }
 608         } else {
 609                 memset(&fd_prot, 0, sizeof(struct fd_prot));
 610
 611                 if (cmd->prot_type) {
 612                         u32 sectors = cmd->data_length / dev->dev_attrib.block_size;
 613
 614                         ret = fd_do_prot_rw(cmd, &fd_prot, false);
 615                         if (ret < 0)
 616                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 617
 618                         rc = sbc_dif_verify_write(cmd, cmd->t_task_lba, sectors,
 619                                                   0, fd_prot.prot_sg, 0);
 620                         if (rc) {
 621                                 kfree(fd_prot.prot_sg);
 622                                 vfree(fd_prot.prot_buf);
 623                                 return rc;
 624                         }
 625                 }
 626
 627                 ret = fd_do_rw(cmd, sgl, sgl_nents, 1);
 628                 /*
 629                  * Perform implicit vfs_fsync_range() for fd_do_writev() ops
 630                  * for SCSI WRITEs with Forced Unit Access (FUA) set.
 631                  * Allow this to happen independent of WCE=0 setting.
 632                  */
 633                 if (ret > 0 &&
 634                     dev->dev_attrib.emulate_fua_write > 0 &&
 635                     (cmd->se_cmd_flags & SCF_FUA)) {
 636                         struct fd_dev *fd_dev = FD_DEV(dev);
 637                         loff_t start = cmd->t_task_lba *
 638                                 dev->dev_attrib.block_size;
 639                         loff_t end;
 640
 641                         if (cmd->data_length)
 642                                 end = start + cmd->data_length - 1;
 643                         else
 644                                 end = LLONG_MAX;
 645
 646                         vfs_fsync_range(fd_dev->fd_file, start, end, 1);
 647                 }
 648
 649                 if (ret > 0 && cmd->prot_type) {
 650                         ret = fd_do_prot_rw(cmd, &fd_prot, true);
 651                         if (ret < 0)
 652                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 653                 }
 654         }
 655
 656         if (ret < 0) {
 657                 kfree(fd_prot.prot_sg);
 658                 vfree(fd_prot.prot_buf);
 659                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 660         }
 661
 662         if (ret)
 663                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 664         return 0;
 665 }
 666
 667 enum {
 668         Opt_fd_dev_name, Opt_fd_dev_size, Opt_fd_buffered_io, Opt_err
 669 };
 670
 671 static match_table_t tokens = {
 672         {Opt_fd_dev_name, "fd_dev_name=%s"},
 673         {Opt_fd_dev_size, "fd_dev_size=%s"},
 674         {Opt_fd_buffered_io, "fd_buffered_io=%d"},
 675         {Opt_err, NULL}
 676 };
 677
 678 static ssize_t fd_set_configfs_dev_params(struct se_device *dev,
 679                 const char *page, ssize_t count)
 680 {
 681         struct fd_dev *fd_dev = FD_DEV(dev);
 682         char *orig, *ptr, *arg_p, *opts;
 683         substring_t args[MAX_OPT_ARGS];
 684         int ret = 0, arg, token;
 685
 686         opts = kstrdup(page, GFP_KERNEL);
 687         if (!opts)
 688                 return -ENOMEM;
 689
 690         orig = opts;
 691
 692         while ((ptr = strsep(&opts, ",\n")) != NULL) {
 693                 if (!*ptr)
 694                         continue;
 695
 696                 token = match_token(ptr, tokens, args);
 697                 switch (token) {
 698                 case Opt_fd_dev_name:
 699                         if (match_strlcpy(fd_dev->fd_dev_name, &args[0],
 700                                 FD_MAX_DEV_NAME) == 0) {
 701                                 ret = -EINVAL;
 702                                 break;
 703                         }
 704                         pr_debug("FILEIO: Referencing Path: %s\n",
 705                                         fd_dev->fd_dev_name);
 706                         fd_dev->fbd_flags |= FBDF_HAS_PATH;
 707                         break;
 708                 case Opt_fd_dev_size:
 709                         arg_p = match_strdup(&args[0]);
 710                         if (!arg_p) {
 711                                 ret = -ENOMEM;
 712                                 break;
 713                         }
 714                         ret = kstrtoull(arg_p, 0, &fd_dev->fd_dev_size);
 715                         kfree(arg_p);
 716                         if (ret < 0) {
 717                                 pr_err("kstrtoull() failed for"
 718                                                 " fd_dev_size=\n");
 719                                 goto out;
 720                         }
 721                         pr_debug("FILEIO: Referencing Size: %llu"
 722                                         " bytes\n", fd_dev->fd_dev_size);
 723                         fd_dev->fbd_flags |= FBDF_HAS_SIZE;
 724                         break;
 725                 case Opt_fd_buffered_io:
 726                         ret = match_int(args, &arg);
 727                         if (ret)
 728                                 goto out;
 729                         if (arg != 1) {
 730                                 pr_err("bogus fd_buffered_io=%d value\n", arg);
 731                                 ret = -EINVAL;
 732                                 goto out;
 733                         }
 734
 735                         pr_debug("FILEIO: Using buffered I/O"
 736                                 " operations for struct fd_dev\n");
 737
 738                         fd_dev->fbd_flags |= FDBD_HAS_BUFFERED_IO_WCE;
 739                         break;
 740                 default:
 741                         break;
 742                 }
 743         }
 744
 745 out:
 746         kfree(orig);
 747         return (!ret) ? count : ret;
 748 }
 749
 750 static ssize_t fd_show_configfs_dev_params(struct se_device *dev, char *b)
 751 {
 752         struct fd_dev *fd_dev = FD_DEV(dev);
 753         ssize_t bl = 0;
 754
 755         bl = sprintf(b + bl, "TCM FILEIO ID: %u", fd_dev->fd_dev_id);
 756         bl += sprintf(b + bl, "        File: %s  Size: %llu  Mode: %s\n",
 757                 fd_dev->fd_dev_name, fd_dev->fd_dev_size,
 758                 (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) ?
 759                 "Buffered-WCE" : "O_DSYNC");
 760         return bl;
 761 }
 762
 763 static sector_t fd_get_blocks(struct se_device *dev)
 764 {
 765         struct fd_dev *fd_dev = FD_DEV(dev);
 766         struct file *f = fd_dev->fd_file;
 767         struct inode *i = f->f_mapping->host;
 768         unsigned long long dev_size;
 769         /*
 770          * When using a file that references an underlying struct block_device,
 771          * ensure dev_size is always based on the current inode size in order
 772          * to handle underlying block_device resize operations.
 773          */
 774         if (S_ISBLK(i->i_mode))
 775                 dev_size = i_size_read(i);
 776         else
 777                 dev_size = fd_dev->fd_dev_size;
 778
 779         return div_u64(dev_size - dev->dev_attrib.block_size,
 780                        dev->dev_attrib.block_size);
 781 }
 782
 783 static int fd_init_prot(struct se_device *dev)
 784 {
 785         struct fd_dev *fd_dev = FD_DEV(dev);
 786         struct file *prot_file, *file = fd_dev->fd_file;
 787         struct inode *inode;
 788         int ret, flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
 789         char buf[FD_MAX_DEV_PROT_NAME];
 790
 791         if (!file) {
 792                 pr_err("Unable to locate fd_dev->fd_file\n");
 793                 return -ENODEV;
 794         }
 795
 796         inode = file->f_mapping->host;
 797         if (S_ISBLK(inode->i_mode)) {
 798                 pr_err("FILEIO Protection emulation only supported on"
 799                        " !S_ISBLK\n");
 800                 return -ENOSYS;
 801         }
 802
 803         if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE)
 804                 flags &= ~O_DSYNC;
 805
 806         snprintf(buf, FD_MAX_DEV_PROT_NAME, "%s.protection",
 807                  fd_dev->fd_dev_name);
 808
 809         prot_file = filp_open(buf, flags, 0600);
 810         if (IS_ERR(prot_file)) {
 811                 pr_err("filp_open(%s) failed\n", buf);
 812                 ret = PTR_ERR(prot_file);
 813                 return ret;
 814         }
 815         fd_dev->fd_prot_file = prot_file;
 816
 817         return 0;
 818 }
 819
 820 static int fd_format_prot(struct se_device *dev)
 821 {
 822         struct fd_dev *fd_dev = FD_DEV(dev);
 823         struct file *prot_fd = fd_dev->fd_prot_file;
 824         sector_t prot_length, prot;
 825         unsigned char *buf;
 826         loff_t pos = 0;
 827         int unit_size = FDBD_FORMAT_UNIT_SIZE * dev->dev_attrib.block_size;
 828         int rc, ret = 0, size, len;
 829
 830         if (!dev->dev_attrib.pi_prot_type) {
 831                 pr_err("Unable to format_prot while pi_prot_type == 0\n");
 832                 return -ENODEV;
 833         }
 834         if (!prot_fd) {
 835                 pr_err("Unable to locate fd_dev->fd_prot_file\n");
 836                 return -ENODEV;
 837         }
 838
 839         buf = vzalloc(unit_size);
 840         if (!buf) {
 841                 pr_err("Unable to allocate FILEIO prot buf\n");
 842                 return -ENOMEM;
 843         }
 844         prot_length = (dev->transport->get_blocks(dev) + 1) * dev->prot_length;
 845         size = prot_length;
 846
 847         pr_debug("Using FILEIO prot_length: %llu\n",
 848                  (unsigned long long)prot_length);
 849
 850         memset(buf, 0xff, unit_size);
 851         for (prot = 0; prot < prot_length; prot += unit_size) {
 852                 len = min(unit_size, size);
 853                 rc = kernel_write(prot_fd, buf, len, pos);
 854                 if (rc != len) {
 855                         pr_err("vfs_write to prot file failed: %d\n", rc);
 856                         ret = -ENODEV;
 857                         goto out;
 858                 }
 859                 pos += len;
 860                 size -= len;
 861         }
 862
 863 out:
 864         vfree(buf);
 865         return ret;
 866 }
 867
 868 static void fd_free_prot(struct se_device *dev)
 869 {
 870         struct fd_dev *fd_dev = FD_DEV(dev);
 871
 872         if (!fd_dev->fd_prot_file)
 873                 return;
 874
 875         filp_close(fd_dev->fd_prot_file, NULL);
 876         fd_dev->fd_prot_file = NULL;
 877 }
 878
 879 static struct sbc_ops fd_sbc_ops = {
 880         .execute_rw             = fd_execute_rw,
 881         .execute_sync_cache     = fd_execute_sync_cache,
 882         .execute_write_same     = fd_execute_write_same,
 883         .execute_write_same_unmap = fd_execute_write_same_unmap,
 884         .execute_unmap          = fd_execute_unmap,
 885 };
 886
 887 static sense_reason_t
 888 fd_parse_cdb(struct se_cmd *cmd)
 889 {
 890         return sbc_parse_cdb(cmd, &fd_sbc_ops);
 891 }
 892
 893 DEF_TB_DEFAULT_ATTRIBS(fileio);
 894
 895 static struct configfs_attribute *fileio_backend_dev_attrs[] = {
 896         &fileio_dev_attrib_emulate_model_alias.attr,
 897         &fileio_dev_attrib_emulate_dpo.attr,
 898         &fileio_dev_attrib_emulate_fua_write.attr,
 899         &fileio_dev_attrib_emulate_fua_read.attr,
 900         &fileio_dev_attrib_emulate_write_cache.attr,
 901         &fileio_dev_attrib_emulate_ua_intlck_ctrl.attr,
 902         &fileio_dev_attrib_emulate_tas.attr,
 903         &fileio_dev_attrib_emulate_tpu.attr,
 904         &fileio_dev_attrib_emulate_tpws.attr,
 905         &fileio_dev_attrib_emulate_caw.attr,
 906         &fileio_dev_attrib_emulate_3pc.attr,
 907         &fileio_dev_attrib_pi_prot_type.attr,
 908         &fileio_dev_attrib_hw_pi_prot_type.attr,
 909         &fileio_dev_attrib_pi_prot_format.attr,
 910         &fileio_dev_attrib_enforce_pr_isids.attr,
 911         &fileio_dev_attrib_is_nonrot.attr,
 912         &fileio_dev_attrib_emulate_rest_reord.attr,
 913         &fileio_dev_attrib_force_pr_aptpl.attr,
 914         &fileio_dev_attrib_hw_block_size.attr,
 915         &fileio_dev_attrib_block_size.attr,
 916         &fileio_dev_attrib_hw_max_sectors.attr,
 917         &fileio_dev_attrib_optimal_sectors.attr,
 918         &fileio_dev_attrib_hw_queue_depth.attr,
 919         &fileio_dev_attrib_queue_depth.attr,
 920         &fileio_dev_attrib_max_unmap_lba_count.attr,
 921         &fileio_dev_attrib_max_unmap_block_desc_count.attr,
 922         &fileio_dev_attrib_unmap_granularity.attr,
 923         &fileio_dev_attrib_unmap_granularity_alignment.attr,
 924         &fileio_dev_attrib_max_write_same_len.attr,
 925         NULL,
 926 };
 927
 928 static struct se_subsystem_api fileio_template = {
 929         .name                   = "fileio",
 930         .inquiry_prod           = "FILEIO",
 931         .inquiry_rev            = FD_VERSION,
 932         .owner                  = THIS_MODULE,
 933         .transport_type         = TRANSPORT_PLUGIN_VHBA_PDEV,
 934         .attach_hba             = fd_attach_hba,
 935         .detach_hba             = fd_detach_hba,
 936         .alloc_device           = fd_alloc_device,
 937         .configure_device       = fd_configure_device,
 938         .free_device            = fd_free_device,
 939         .parse_cdb              = fd_parse_cdb,
 940         .set_configfs_dev_params = fd_set_configfs_dev_params,
 941         .show_configfs_dev_params = fd_show_configfs_dev_params,
 942         .get_device_type        = sbc_get_device_type,
 943         .get_blocks             = fd_get_blocks,
 944         .init_prot              = fd_init_prot,
 945         .format_prot            = fd_format_prot,
 946         .free_prot              = fd_free_prot,
 947 };
 948
 949 static int __init fileio_module_init(void)
 950 {
 951         struct target_backend_cits *tbc = &fileio_template.tb_cits;
 952
 953         target_core_setup_sub_cits(&fileio_template);
 954         tbc->tb_dev_attrib_cit.ct_attrs = fileio_backend_dev_attrs;
 955
 956         return transport_subsystem_register(&fileio_template);
 957 }
 958
 959 static void __exit fileio_module_exit(void)
 960 {
 961         transport_subsystem_release(&fileio_template);
 962 }
 963
 964 MODULE_DESCRIPTION("TCM FILEIO subsystem plugin");
 965 MODULE_AUTHOR("nab@Linux-iSCSI.org");
 966 MODULE_LICENSE("GPL");
 967
 968 module_init(fileio_module_init);
 969 module_exit(fileio_module_exit);