1 /******************************************************************************* 2 * Filename: target_core_file.c 3 * 4 * This file contains the Storage Engine <-> FILEIO transport specific functions 5 * 6 * Copyright (c) 2005 PyX Technologies, Inc. 7 * Copyright (c) 2005-2006 SBE, Inc. All Rights Reserved. 8 * Copyright (c) 2007-2010 Rising Tide Systems 9 * Copyright (c) 2008-2010 Linux-iSCSI.org 10 * 11 * Nicholas A. Bellinger <nab@kernel.org> 12 * 13 * This program is free software; you can redistribute it and/or modify 14 * it under the terms of the GNU General Public License as published by 15 * the Free Software Foundation; either version 2 of the License, or 16 * (at your option) any later version. 17 * 18 * This program is distributed in the hope that it will be useful, 19 * but WITHOUT ANY WARRANTY; without even the implied warranty of 20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 21 * GNU General Public License for more details. 22 * 23 * You should have received a copy of the GNU General Public License 24 * along with this program; if not, write to the Free Software 25 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 26 * 27 ******************************************************************************/ 28 29 #include <linux/string.h> 30 #include <linux/parser.h> 31 #include <linux/timer.h> 32 #include <linux/blkdev.h> 33 #include <linux/slab.h> 34 #include <linux/spinlock.h> 35 #include <linux/module.h> 36 #include <scsi/scsi.h> 37 #include <scsi/scsi_host.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 struct se_subsystem_api fileio_template; 45 46 /* fd_attach_hba(): (Part of se_subsystem_api_t template) 47 * 48 * 49 */ 50 static int fd_attach_hba(struct se_hba *hba, u32 host_id) 51 { 52 struct fd_host *fd_host; 53 54 fd_host = kzalloc(sizeof(struct fd_host), GFP_KERNEL); 55 if (!fd_host) { 56 pr_err("Unable to allocate memory for struct fd_host\n"); 57 return -ENOMEM; 58 } 59 60 fd_host->fd_host_id = host_id; 61 62 hba->hba_ptr = fd_host; 63 64 pr_debug("CORE_HBA[%d] - TCM FILEIO HBA Driver %s on Generic" 65 " Target Core Stack %s\n", hba->hba_id, FD_VERSION, 66 TARGET_CORE_MOD_VERSION); 67 pr_debug("CORE_HBA[%d] - Attached FILEIO HBA: %u to Generic" 68 " MaxSectors: %u\n", 69 hba->hba_id, fd_host->fd_host_id, FD_MAX_SECTORS); 70 71 return 0; 72 } 73 74 static void fd_detach_hba(struct se_hba *hba) 75 { 76 struct fd_host *fd_host = hba->hba_ptr; 77 78 pr_debug("CORE_HBA[%d] - Detached FILEIO HBA: %u from Generic" 79 " Target Core\n", hba->hba_id, fd_host->fd_host_id); 80 81 kfree(fd_host); 82 hba->hba_ptr = NULL; 83 } 84 85 static void *fd_allocate_virtdevice(struct se_hba *hba, const char *name) 86 { 87 struct fd_dev *fd_dev; 88 struct fd_host *fd_host = hba->hba_ptr; 89 90 fd_dev = kzalloc(sizeof(struct fd_dev), GFP_KERNEL); 91 if (!fd_dev) { 92 pr_err("Unable to allocate memory for struct fd_dev\n"); 93 return NULL; 94 } 95 96 fd_dev->fd_host = fd_host; 97 98 pr_debug("FILEIO: Allocated fd_dev for %p\n", name); 99 100 return fd_dev; 101 } 102 103 /* fd_create_virtdevice(): (Part of se_subsystem_api_t template) 104 * 105 * 106 */ 107 static struct se_device *fd_create_virtdevice( 108 struct se_hba *hba, 109 struct se_subsystem_dev *se_dev, 110 void *p) 111 { 112 struct se_device *dev; 113 struct se_dev_limits dev_limits; 114 struct queue_limits *limits; 115 struct fd_dev *fd_dev = p; 116 struct fd_host *fd_host = hba->hba_ptr; 117 struct file *file; 118 struct inode *inode = NULL; 119 int dev_flags = 0, flags, ret = -EINVAL; 120 121 memset(&dev_limits, 0, sizeof(struct se_dev_limits)); 122 123 /* 124 * Use O_DSYNC by default instead of O_SYNC to forgo syncing 125 * of pure timestamp updates. 126 */ 127 flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC; 128 /* 129 * Optionally allow fd_buffered_io=1 to be enabled for people 130 * who want use the fs buffer cache as an WriteCache mechanism. 131 * 132 * This means that in event of a hard failure, there is a risk 133 * of silent data-loss if the SCSI client has *not* performed a 134 * forced unit access (FUA) write, or issued SYNCHRONIZE_CACHE 135 * to write-out the entire device cache. 136 */ 137 if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) { 138 pr_debug("FILEIO: Disabling O_DSYNC, using buffered FILEIO\n"); 139 flags &= ~O_DSYNC; 140 } 141 142 file = filp_open(fd_dev->fd_dev_name, flags, 0600); 143 if (IS_ERR(file)) { 144 pr_err("filp_open(%s) failed\n", fd_dev->fd_dev_name); 145 ret = PTR_ERR(file); 146 goto fail; 147 } 148 fd_dev->fd_file = file; 149 /* 150 * If using a block backend with this struct file, we extract 151 * fd_dev->fd_[block,dev]_size from struct block_device. 152 * 153 * Otherwise, we use the passed fd_size= from configfs 154 */ 155 inode = file->f_mapping->host; 156 if (S_ISBLK(inode->i_mode)) { 157 struct request_queue *q; 158 unsigned long long dev_size; 159 /* 160 * Setup the local scope queue_limits from struct request_queue->limits 161 * to pass into transport_add_device_to_core_hba() as struct se_dev_limits. 162 */ 163 q = bdev_get_queue(inode->i_bdev); 164 limits = &dev_limits.limits; 165 limits->logical_block_size = bdev_logical_block_size(inode->i_bdev); 166 limits->max_hw_sectors = queue_max_hw_sectors(q); 167 limits->max_sectors = queue_max_sectors(q); 168 /* 169 * Determine the number of bytes from i_size_read() minus 170 * one (1) logical sector from underlying struct block_device 171 */ 172 fd_dev->fd_block_size = bdev_logical_block_size(inode->i_bdev); 173 dev_size = (i_size_read(file->f_mapping->host) - 174 fd_dev->fd_block_size); 175 176 pr_debug("FILEIO: Using size: %llu bytes from struct" 177 " block_device blocks: %llu logical_block_size: %d\n", 178 dev_size, div_u64(dev_size, fd_dev->fd_block_size), 179 fd_dev->fd_block_size); 180 } else { 181 if (!(fd_dev->fbd_flags & FBDF_HAS_SIZE)) { 182 pr_err("FILEIO: Missing fd_dev_size=" 183 " parameter, and no backing struct" 184 " block_device\n"); 185 goto fail; 186 } 187 188 limits = &dev_limits.limits; 189 limits->logical_block_size = FD_BLOCKSIZE; 190 limits->max_hw_sectors = FD_MAX_SECTORS; 191 limits->max_sectors = FD_MAX_SECTORS; 192 fd_dev->fd_block_size = FD_BLOCKSIZE; 193 } 194 195 dev_limits.hw_queue_depth = FD_MAX_DEVICE_QUEUE_DEPTH; 196 dev_limits.queue_depth = FD_DEVICE_QUEUE_DEPTH; 197 198 dev = transport_add_device_to_core_hba(hba, &fileio_template, 199 se_dev, dev_flags, fd_dev, 200 &dev_limits, "FILEIO", FD_VERSION); 201 if (!dev) 202 goto fail; 203 204 if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) { 205 pr_debug("FILEIO: Forcing setting of emulate_write_cache=1" 206 " with FDBD_HAS_BUFFERED_IO_WCE\n"); 207 dev->se_sub_dev->se_dev_attrib.emulate_write_cache = 1; 208 } 209 210 fd_dev->fd_dev_id = fd_host->fd_host_dev_id_count++; 211 fd_dev->fd_queue_depth = dev->queue_depth; 212 213 pr_debug("CORE_FILE[%u] - Added TCM FILEIO Device ID: %u at %s," 214 " %llu total bytes\n", fd_host->fd_host_id, fd_dev->fd_dev_id, 215 fd_dev->fd_dev_name, fd_dev->fd_dev_size); 216 217 return dev; 218 fail: 219 if (fd_dev->fd_file) { 220 filp_close(fd_dev->fd_file, NULL); 221 fd_dev->fd_file = NULL; 222 } 223 return ERR_PTR(ret); 224 } 225 226 /* fd_free_device(): (Part of se_subsystem_api_t template) 227 * 228 * 229 */ 230 static void fd_free_device(void *p) 231 { 232 struct fd_dev *fd_dev = p; 233 234 if (fd_dev->fd_file) { 235 filp_close(fd_dev->fd_file, NULL); 236 fd_dev->fd_file = NULL; 237 } 238 239 kfree(fd_dev); 240 } 241 242 static int fd_do_readv(struct se_cmd *cmd, struct scatterlist *sgl, 243 u32 sgl_nents) 244 { 245 struct se_device *se_dev = cmd->se_dev; 246 struct fd_dev *dev = se_dev->dev_ptr; 247 struct file *fd = dev->fd_file; 248 struct scatterlist *sg; 249 struct iovec *iov; 250 mm_segment_t old_fs; 251 loff_t pos = (cmd->t_task_lba * 252 se_dev->se_sub_dev->se_dev_attrib.block_size); 253 int ret = 0, i; 254 255 iov = kzalloc(sizeof(struct iovec) * sgl_nents, GFP_KERNEL); 256 if (!iov) { 257 pr_err("Unable to allocate fd_do_readv iov[]\n"); 258 return -ENOMEM; 259 } 260 261 for_each_sg(sgl, sg, sgl_nents, i) { 262 iov[i].iov_len = sg->length; 263 iov[i].iov_base = sg_virt(sg); 264 } 265 266 old_fs = get_fs(); 267 set_fs(get_ds()); 268 ret = vfs_readv(fd, &iov[0], sgl_nents, &pos); 269 set_fs(old_fs); 270 271 kfree(iov); 272 /* 273 * Return zeros and GOOD status even if the READ did not return 274 * the expected virt_size for struct file w/o a backing struct 275 * block_device. 276 */ 277 if (S_ISBLK(fd->f_dentry->d_inode->i_mode)) { 278 if (ret < 0 || ret != cmd->data_length) { 279 pr_err("vfs_readv() returned %d," 280 " expecting %d for S_ISBLK\n", ret, 281 (int)cmd->data_length); 282 return (ret < 0 ? ret : -EINVAL); 283 } 284 } else { 285 if (ret < 0) { 286 pr_err("vfs_readv() returned %d for non" 287 " S_ISBLK\n", ret); 288 return ret; 289 } 290 } 291 292 return 1; 293 } 294 295 static int fd_do_writev(struct se_cmd *cmd, struct scatterlist *sgl, 296 u32 sgl_nents) 297 { 298 struct se_device *se_dev = cmd->se_dev; 299 struct fd_dev *dev = se_dev->dev_ptr; 300 struct file *fd = dev->fd_file; 301 struct scatterlist *sg; 302 struct iovec *iov; 303 mm_segment_t old_fs; 304 loff_t pos = (cmd->t_task_lba * 305 se_dev->se_sub_dev->se_dev_attrib.block_size); 306 int ret, i = 0; 307 308 iov = kzalloc(sizeof(struct iovec) * sgl_nents, GFP_KERNEL); 309 if (!iov) { 310 pr_err("Unable to allocate fd_do_writev iov[]\n"); 311 return -ENOMEM; 312 } 313 314 for_each_sg(sgl, sg, sgl_nents, i) { 315 iov[i].iov_len = sg->length; 316 iov[i].iov_base = sg_virt(sg); 317 } 318 319 old_fs = get_fs(); 320 set_fs(get_ds()); 321 ret = vfs_writev(fd, &iov[0], sgl_nents, &pos); 322 set_fs(old_fs); 323 324 kfree(iov); 325 326 if (ret < 0 || ret != cmd->data_length) { 327 pr_err("vfs_writev() returned %d\n", ret); 328 return (ret < 0 ? ret : -EINVAL); 329 } 330 331 return 1; 332 } 333 334 static int fd_execute_sync_cache(struct se_cmd *cmd) 335 { 336 struct se_device *dev = cmd->se_dev; 337 struct fd_dev *fd_dev = dev->dev_ptr; 338 int immed = (cmd->t_task_cdb[1] & 0x2); 339 loff_t start, end; 340 int ret; 341 342 /* 343 * If the Immediate bit is set, queue up the GOOD response 344 * for this SYNCHRONIZE_CACHE op 345 */ 346 if (immed) 347 target_complete_cmd(cmd, SAM_STAT_GOOD); 348 349 /* 350 * Determine if we will be flushing the entire device. 351 */ 352 if (cmd->t_task_lba == 0 && cmd->data_length == 0) { 353 start = 0; 354 end = LLONG_MAX; 355 } else { 356 start = cmd->t_task_lba * dev->se_sub_dev->se_dev_attrib.block_size; 357 if (cmd->data_length) 358 end = start + cmd->data_length; 359 else 360 end = LLONG_MAX; 361 } 362 363 ret = vfs_fsync_range(fd_dev->fd_file, start, end, 1); 364 if (ret != 0) 365 pr_err("FILEIO: vfs_fsync_range() failed: %d\n", ret); 366 367 if (immed) 368 return 0; 369 370 if (ret) { 371 cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 372 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION); 373 } else { 374 target_complete_cmd(cmd, SAM_STAT_GOOD); 375 } 376 377 return 0; 378 } 379 380 static int fd_execute_rw(struct se_cmd *cmd) 381 { 382 struct scatterlist *sgl = cmd->t_data_sg; 383 u32 sgl_nents = cmd->t_data_nents; 384 enum dma_data_direction data_direction = cmd->data_direction; 385 struct se_device *dev = cmd->se_dev; 386 int ret = 0; 387 388 /* 389 * Call vectorized fileio functions to map struct scatterlist 390 * physical memory addresses to struct iovec virtual memory. 391 */ 392 if (data_direction == DMA_FROM_DEVICE) { 393 ret = fd_do_readv(cmd, sgl, sgl_nents); 394 } else { 395 ret = fd_do_writev(cmd, sgl, sgl_nents); 396 /* 397 * Perform implict vfs_fsync_range() for fd_do_writev() ops 398 * for SCSI WRITEs with Forced Unit Access (FUA) set. 399 * Allow this to happen independent of WCE=0 setting. 400 */ 401 if (ret > 0 && 402 dev->se_sub_dev->se_dev_attrib.emulate_fua_write > 0 && 403 (cmd->se_cmd_flags & SCF_FUA)) { 404 struct fd_dev *fd_dev = dev->dev_ptr; 405 loff_t start = cmd->t_task_lba * 406 dev->se_sub_dev->se_dev_attrib.block_size; 407 loff_t end = start + cmd->data_length; 408 409 vfs_fsync_range(fd_dev->fd_file, start, end, 1); 410 } 411 } 412 413 if (ret < 0) { 414 cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 415 return ret; 416 } 417 if (ret) 418 target_complete_cmd(cmd, SAM_STAT_GOOD); 419 return 0; 420 } 421 422 enum { 423 Opt_fd_dev_name, Opt_fd_dev_size, Opt_fd_buffered_io, Opt_err 424 }; 425 426 static match_table_t tokens = { 427 {Opt_fd_dev_name, "fd_dev_name=%s"}, 428 {Opt_fd_dev_size, "fd_dev_size=%s"}, 429 {Opt_fd_buffered_io, "fd_buffered_io=%d"}, 430 {Opt_err, NULL} 431 }; 432 433 static ssize_t fd_set_configfs_dev_params( 434 struct se_hba *hba, 435 struct se_subsystem_dev *se_dev, 436 const char *page, ssize_t count) 437 { 438 struct fd_dev *fd_dev = se_dev->se_dev_su_ptr; 439 char *orig, *ptr, *arg_p, *opts; 440 substring_t args[MAX_OPT_ARGS]; 441 int ret = 0, arg, token; 442 443 opts = kstrdup(page, GFP_KERNEL); 444 if (!opts) 445 return -ENOMEM; 446 447 orig = opts; 448 449 while ((ptr = strsep(&opts, ",\n")) != NULL) { 450 if (!*ptr) 451 continue; 452 453 token = match_token(ptr, tokens, args); 454 switch (token) { 455 case Opt_fd_dev_name: 456 if (match_strlcpy(fd_dev->fd_dev_name, &args[0], 457 FD_MAX_DEV_NAME) == 0) { 458 ret = -EINVAL; 459 break; 460 } 461 pr_debug("FILEIO: Referencing Path: %s\n", 462 fd_dev->fd_dev_name); 463 fd_dev->fbd_flags |= FBDF_HAS_PATH; 464 break; 465 case Opt_fd_dev_size: 466 arg_p = match_strdup(&args[0]); 467 if (!arg_p) { 468 ret = -ENOMEM; 469 break; 470 } 471 ret = strict_strtoull(arg_p, 0, &fd_dev->fd_dev_size); 472 kfree(arg_p); 473 if (ret < 0) { 474 pr_err("strict_strtoull() failed for" 475 " fd_dev_size=\n"); 476 goto out; 477 } 478 pr_debug("FILEIO: Referencing Size: %llu" 479 " bytes\n", fd_dev->fd_dev_size); 480 fd_dev->fbd_flags |= FBDF_HAS_SIZE; 481 break; 482 case Opt_fd_buffered_io: 483 match_int(args, &arg); 484 if (arg != 1) { 485 pr_err("bogus fd_buffered_io=%d value\n", arg); 486 ret = -EINVAL; 487 goto out; 488 } 489 490 pr_debug("FILEIO: Using buffered I/O" 491 " operations for struct fd_dev\n"); 492 493 fd_dev->fbd_flags |= FDBD_HAS_BUFFERED_IO_WCE; 494 break; 495 default: 496 break; 497 } 498 } 499 500 out: 501 kfree(orig); 502 return (!ret) ? count : ret; 503 } 504 505 static ssize_t fd_check_configfs_dev_params(struct se_hba *hba, struct se_subsystem_dev *se_dev) 506 { 507 struct fd_dev *fd_dev = se_dev->se_dev_su_ptr; 508 509 if (!(fd_dev->fbd_flags & FBDF_HAS_PATH)) { 510 pr_err("Missing fd_dev_name=\n"); 511 return -EINVAL; 512 } 513 514 return 0; 515 } 516 517 static ssize_t fd_show_configfs_dev_params( 518 struct se_hba *hba, 519 struct se_subsystem_dev *se_dev, 520 char *b) 521 { 522 struct fd_dev *fd_dev = se_dev->se_dev_su_ptr; 523 ssize_t bl = 0; 524 525 bl = sprintf(b + bl, "TCM FILEIO ID: %u", fd_dev->fd_dev_id); 526 bl += sprintf(b + bl, " File: %s Size: %llu Mode: %s\n", 527 fd_dev->fd_dev_name, fd_dev->fd_dev_size, 528 (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) ? 529 "Buffered-WCE" : "O_DSYNC"); 530 return bl; 531 } 532 533 /* fd_get_device_rev(): (Part of se_subsystem_api_t template) 534 * 535 * 536 */ 537 static u32 fd_get_device_rev(struct se_device *dev) 538 { 539 return SCSI_SPC_2; /* Returns SPC-3 in Initiator Data */ 540 } 541 542 /* fd_get_device_type(): (Part of se_subsystem_api_t template) 543 * 544 * 545 */ 546 static u32 fd_get_device_type(struct se_device *dev) 547 { 548 return TYPE_DISK; 549 } 550 551 static sector_t fd_get_blocks(struct se_device *dev) 552 { 553 struct fd_dev *fd_dev = dev->dev_ptr; 554 struct file *f = fd_dev->fd_file; 555 struct inode *i = f->f_mapping->host; 556 unsigned long long dev_size; 557 /* 558 * When using a file that references an underlying struct block_device, 559 * ensure dev_size is always based on the current inode size in order 560 * to handle underlying block_device resize operations. 561 */ 562 if (S_ISBLK(i->i_mode)) 563 dev_size = (i_size_read(i) - fd_dev->fd_block_size); 564 else 565 dev_size = fd_dev->fd_dev_size; 566 567 return div_u64(dev_size, dev->se_sub_dev->se_dev_attrib.block_size); 568 } 569 570 static struct spc_ops fd_spc_ops = { 571 .execute_rw = fd_execute_rw, 572 .execute_sync_cache = fd_execute_sync_cache, 573 }; 574 575 static int fd_parse_cdb(struct se_cmd *cmd) 576 { 577 return sbc_parse_cdb(cmd, &fd_spc_ops); 578 } 579 580 static struct se_subsystem_api fileio_template = { 581 .name = "fileio", 582 .owner = THIS_MODULE, 583 .transport_type = TRANSPORT_PLUGIN_VHBA_PDEV, 584 .attach_hba = fd_attach_hba, 585 .detach_hba = fd_detach_hba, 586 .allocate_virtdevice = fd_allocate_virtdevice, 587 .create_virtdevice = fd_create_virtdevice, 588 .free_device = fd_free_device, 589 .parse_cdb = fd_parse_cdb, 590 .check_configfs_dev_params = fd_check_configfs_dev_params, 591 .set_configfs_dev_params = fd_set_configfs_dev_params, 592 .show_configfs_dev_params = fd_show_configfs_dev_params, 593 .get_device_rev = fd_get_device_rev, 594 .get_device_type = fd_get_device_type, 595 .get_blocks = fd_get_blocks, 596 }; 597 598 static int __init fileio_module_init(void) 599 { 600 return transport_subsystem_register(&fileio_template); 601 } 602 603 static void fileio_module_exit(void) 604 { 605 transport_subsystem_release(&fileio_template); 606 } 607 608 MODULE_DESCRIPTION("TCM FILEIO subsystem plugin"); 609 MODULE_AUTHOR("nab@Linux-iSCSI.org"); 610 MODULE_LICENSE("GPL"); 611 612 module_init(fileio_module_init); 613 module_exit(fileio_module_exit); 614