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 file = filp_open(fd_dev->fd_dev_name, flags, 0600); 130 if (IS_ERR(file)) { 131 pr_err("filp_open(%s) failed\n", fd_dev->fd_dev_name); 132 ret = PTR_ERR(file); 133 goto fail; 134 } 135 fd_dev->fd_file = file; 136 /* 137 * If using a block backend with this struct file, we extract 138 * fd_dev->fd_[block,dev]_size from struct block_device. 139 * 140 * Otherwise, we use the passed fd_size= from configfs 141 */ 142 inode = file->f_mapping->host; 143 if (S_ISBLK(inode->i_mode)) { 144 struct request_queue *q; 145 unsigned long long dev_size; 146 /* 147 * Setup the local scope queue_limits from struct request_queue->limits 148 * to pass into transport_add_device_to_core_hba() as struct se_dev_limits. 149 */ 150 q = bdev_get_queue(inode->i_bdev); 151 limits = &dev_limits.limits; 152 limits->logical_block_size = bdev_logical_block_size(inode->i_bdev); 153 limits->max_hw_sectors = queue_max_hw_sectors(q); 154 limits->max_sectors = queue_max_sectors(q); 155 /* 156 * Determine the number of bytes from i_size_read() minus 157 * one (1) logical sector from underlying struct block_device 158 */ 159 fd_dev->fd_block_size = bdev_logical_block_size(inode->i_bdev); 160 dev_size = (i_size_read(file->f_mapping->host) - 161 fd_dev->fd_block_size); 162 163 pr_debug("FILEIO: Using size: %llu bytes from struct" 164 " block_device blocks: %llu logical_block_size: %d\n", 165 dev_size, div_u64(dev_size, fd_dev->fd_block_size), 166 fd_dev->fd_block_size); 167 } else { 168 if (!(fd_dev->fbd_flags & FBDF_HAS_SIZE)) { 169 pr_err("FILEIO: Missing fd_dev_size=" 170 " parameter, and no backing struct" 171 " block_device\n"); 172 goto fail; 173 } 174 175 limits = &dev_limits.limits; 176 limits->logical_block_size = FD_BLOCKSIZE; 177 limits->max_hw_sectors = FD_MAX_SECTORS; 178 limits->max_sectors = FD_MAX_SECTORS; 179 fd_dev->fd_block_size = FD_BLOCKSIZE; 180 } 181 182 dev_limits.hw_queue_depth = FD_MAX_DEVICE_QUEUE_DEPTH; 183 dev_limits.queue_depth = FD_DEVICE_QUEUE_DEPTH; 184 185 dev = transport_add_device_to_core_hba(hba, &fileio_template, 186 se_dev, dev_flags, fd_dev, 187 &dev_limits, "FILEIO", FD_VERSION); 188 if (!dev) 189 goto fail; 190 191 fd_dev->fd_dev_id = fd_host->fd_host_dev_id_count++; 192 fd_dev->fd_queue_depth = dev->queue_depth; 193 194 pr_debug("CORE_FILE[%u] - Added TCM FILEIO Device ID: %u at %s," 195 " %llu total bytes\n", fd_host->fd_host_id, fd_dev->fd_dev_id, 196 fd_dev->fd_dev_name, fd_dev->fd_dev_size); 197 198 return dev; 199 fail: 200 if (fd_dev->fd_file) { 201 filp_close(fd_dev->fd_file, NULL); 202 fd_dev->fd_file = NULL; 203 } 204 return ERR_PTR(ret); 205 } 206 207 /* fd_free_device(): (Part of se_subsystem_api_t template) 208 * 209 * 210 */ 211 static void fd_free_device(void *p) 212 { 213 struct fd_dev *fd_dev = p; 214 215 if (fd_dev->fd_file) { 216 filp_close(fd_dev->fd_file, NULL); 217 fd_dev->fd_file = NULL; 218 } 219 220 kfree(fd_dev); 221 } 222 223 static int fd_do_readv(struct se_cmd *cmd, struct scatterlist *sgl, 224 u32 sgl_nents) 225 { 226 struct se_device *se_dev = cmd->se_dev; 227 struct fd_dev *dev = se_dev->dev_ptr; 228 struct file *fd = dev->fd_file; 229 struct scatterlist *sg; 230 struct iovec *iov; 231 mm_segment_t old_fs; 232 loff_t pos = (cmd->t_task_lba * 233 se_dev->se_sub_dev->se_dev_attrib.block_size); 234 int ret = 0, i; 235 236 iov = kzalloc(sizeof(struct iovec) * sgl_nents, GFP_KERNEL); 237 if (!iov) { 238 pr_err("Unable to allocate fd_do_readv iov[]\n"); 239 return -ENOMEM; 240 } 241 242 for_each_sg(sgl, sg, sgl_nents, i) { 243 iov[i].iov_len = sg->length; 244 iov[i].iov_base = sg_virt(sg); 245 } 246 247 old_fs = get_fs(); 248 set_fs(get_ds()); 249 ret = vfs_readv(fd, &iov[0], sgl_nents, &pos); 250 set_fs(old_fs); 251 252 kfree(iov); 253 /* 254 * Return zeros and GOOD status even if the READ did not return 255 * the expected virt_size for struct file w/o a backing struct 256 * block_device. 257 */ 258 if (S_ISBLK(fd->f_dentry->d_inode->i_mode)) { 259 if (ret < 0 || ret != cmd->data_length) { 260 pr_err("vfs_readv() returned %d," 261 " expecting %d for S_ISBLK\n", ret, 262 (int)cmd->data_length); 263 return (ret < 0 ? ret : -EINVAL); 264 } 265 } else { 266 if (ret < 0) { 267 pr_err("vfs_readv() returned %d for non" 268 " S_ISBLK\n", ret); 269 return ret; 270 } 271 } 272 273 return 1; 274 } 275 276 static int fd_do_writev(struct se_cmd *cmd, struct scatterlist *sgl, 277 u32 sgl_nents) 278 { 279 struct se_device *se_dev = cmd->se_dev; 280 struct fd_dev *dev = se_dev->dev_ptr; 281 struct file *fd = dev->fd_file; 282 struct scatterlist *sg; 283 struct iovec *iov; 284 mm_segment_t old_fs; 285 loff_t pos = (cmd->t_task_lba * 286 se_dev->se_sub_dev->se_dev_attrib.block_size); 287 int ret, i = 0; 288 289 iov = kzalloc(sizeof(struct iovec) * sgl_nents, GFP_KERNEL); 290 if (!iov) { 291 pr_err("Unable to allocate fd_do_writev iov[]\n"); 292 return -ENOMEM; 293 } 294 295 for_each_sg(sgl, sg, sgl_nents, i) { 296 iov[i].iov_len = sg->length; 297 iov[i].iov_base = sg_virt(sg); 298 } 299 300 old_fs = get_fs(); 301 set_fs(get_ds()); 302 ret = vfs_writev(fd, &iov[0], sgl_nents, &pos); 303 set_fs(old_fs); 304 305 kfree(iov); 306 307 if (ret < 0 || ret != cmd->data_length) { 308 pr_err("vfs_writev() returned %d\n", ret); 309 return (ret < 0 ? ret : -EINVAL); 310 } 311 312 return 1; 313 } 314 315 static int fd_execute_sync_cache(struct se_cmd *cmd) 316 { 317 struct se_device *dev = cmd->se_dev; 318 struct fd_dev *fd_dev = dev->dev_ptr; 319 int immed = (cmd->t_task_cdb[1] & 0x2); 320 loff_t start, end; 321 int ret; 322 323 /* 324 * If the Immediate bit is set, queue up the GOOD response 325 * for this SYNCHRONIZE_CACHE op 326 */ 327 if (immed) 328 target_complete_cmd(cmd, SAM_STAT_GOOD); 329 330 /* 331 * Determine if we will be flushing the entire device. 332 */ 333 if (cmd->t_task_lba == 0 && cmd->data_length == 0) { 334 start = 0; 335 end = LLONG_MAX; 336 } else { 337 start = cmd->t_task_lba * dev->se_sub_dev->se_dev_attrib.block_size; 338 if (cmd->data_length) 339 end = start + cmd->data_length; 340 else 341 end = LLONG_MAX; 342 } 343 344 ret = vfs_fsync_range(fd_dev->fd_file, start, end, 1); 345 if (ret != 0) 346 pr_err("FILEIO: vfs_fsync_range() failed: %d\n", ret); 347 348 if (immed) 349 return 0; 350 351 if (ret) { 352 cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 353 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION); 354 } else { 355 target_complete_cmd(cmd, SAM_STAT_GOOD); 356 } 357 358 return 0; 359 } 360 361 static int fd_execute_rw(struct se_cmd *cmd) 362 { 363 struct scatterlist *sgl = cmd->t_data_sg; 364 u32 sgl_nents = cmd->t_data_nents; 365 enum dma_data_direction data_direction = cmd->data_direction; 366 struct se_device *dev = cmd->se_dev; 367 int ret = 0; 368 369 /* 370 * Call vectorized fileio functions to map struct scatterlist 371 * physical memory addresses to struct iovec virtual memory. 372 */ 373 if (data_direction == DMA_FROM_DEVICE) { 374 ret = fd_do_readv(cmd, sgl, sgl_nents); 375 } else { 376 ret = fd_do_writev(cmd, sgl, sgl_nents); 377 /* 378 * Perform implict vfs_fsync_range() for fd_do_writev() ops 379 * for SCSI WRITEs with Forced Unit Access (FUA) set. 380 * Allow this to happen independent of WCE=0 setting. 381 */ 382 if (ret > 0 && 383 dev->se_sub_dev->se_dev_attrib.emulate_fua_write > 0 && 384 (cmd->se_cmd_flags & SCF_FUA)) { 385 struct fd_dev *fd_dev = dev->dev_ptr; 386 loff_t start = cmd->t_task_lba * 387 dev->se_sub_dev->se_dev_attrib.block_size; 388 loff_t end = start + cmd->data_length; 389 390 vfs_fsync_range(fd_dev->fd_file, start, end, 1); 391 } 392 } 393 394 if (ret < 0) { 395 cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 396 return ret; 397 } 398 if (ret) 399 target_complete_cmd(cmd, SAM_STAT_GOOD); 400 return 0; 401 } 402 403 enum { 404 Opt_fd_dev_name, Opt_fd_dev_size, Opt_fd_buffered_io, Opt_err 405 }; 406 407 static match_table_t tokens = { 408 {Opt_fd_dev_name, "fd_dev_name=%s"}, 409 {Opt_fd_dev_size, "fd_dev_size=%s"}, 410 {Opt_err, NULL} 411 }; 412 413 static ssize_t fd_set_configfs_dev_params( 414 struct se_hba *hba, 415 struct se_subsystem_dev *se_dev, 416 const char *page, ssize_t count) 417 { 418 struct fd_dev *fd_dev = se_dev->se_dev_su_ptr; 419 char *orig, *ptr, *arg_p, *opts; 420 substring_t args[MAX_OPT_ARGS]; 421 int ret = 0, token; 422 423 opts = kstrdup(page, GFP_KERNEL); 424 if (!opts) 425 return -ENOMEM; 426 427 orig = opts; 428 429 while ((ptr = strsep(&opts, ",\n")) != NULL) { 430 if (!*ptr) 431 continue; 432 433 token = match_token(ptr, tokens, args); 434 switch (token) { 435 case Opt_fd_dev_name: 436 if (match_strlcpy(fd_dev->fd_dev_name, &args[0], 437 FD_MAX_DEV_NAME) == 0) { 438 ret = -EINVAL; 439 break; 440 } 441 pr_debug("FILEIO: Referencing Path: %s\n", 442 fd_dev->fd_dev_name); 443 fd_dev->fbd_flags |= FBDF_HAS_PATH; 444 break; 445 case Opt_fd_dev_size: 446 arg_p = match_strdup(&args[0]); 447 if (!arg_p) { 448 ret = -ENOMEM; 449 break; 450 } 451 ret = strict_strtoull(arg_p, 0, &fd_dev->fd_dev_size); 452 kfree(arg_p); 453 if (ret < 0) { 454 pr_err("strict_strtoull() failed for" 455 " fd_dev_size=\n"); 456 goto out; 457 } 458 pr_debug("FILEIO: Referencing Size: %llu" 459 " bytes\n", fd_dev->fd_dev_size); 460 fd_dev->fbd_flags |= FBDF_HAS_SIZE; 461 break; 462 default: 463 break; 464 } 465 } 466 467 out: 468 kfree(orig); 469 return (!ret) ? count : ret; 470 } 471 472 static ssize_t fd_check_configfs_dev_params(struct se_hba *hba, struct se_subsystem_dev *se_dev) 473 { 474 struct fd_dev *fd_dev = se_dev->se_dev_su_ptr; 475 476 if (!(fd_dev->fbd_flags & FBDF_HAS_PATH)) { 477 pr_err("Missing fd_dev_name=\n"); 478 return -EINVAL; 479 } 480 481 return 0; 482 } 483 484 static ssize_t fd_show_configfs_dev_params( 485 struct se_hba *hba, 486 struct se_subsystem_dev *se_dev, 487 char *b) 488 { 489 struct fd_dev *fd_dev = se_dev->se_dev_su_ptr; 490 ssize_t bl = 0; 491 492 bl = sprintf(b + bl, "TCM FILEIO ID: %u", fd_dev->fd_dev_id); 493 bl += sprintf(b + bl, " File: %s Size: %llu Mode: O_DSYNC\n", 494 fd_dev->fd_dev_name, fd_dev->fd_dev_size); 495 return bl; 496 } 497 498 /* fd_get_device_rev(): (Part of se_subsystem_api_t template) 499 * 500 * 501 */ 502 static u32 fd_get_device_rev(struct se_device *dev) 503 { 504 return SCSI_SPC_2; /* Returns SPC-3 in Initiator Data */ 505 } 506 507 /* fd_get_device_type(): (Part of se_subsystem_api_t template) 508 * 509 * 510 */ 511 static u32 fd_get_device_type(struct se_device *dev) 512 { 513 return TYPE_DISK; 514 } 515 516 static sector_t fd_get_blocks(struct se_device *dev) 517 { 518 struct fd_dev *fd_dev = dev->dev_ptr; 519 struct file *f = fd_dev->fd_file; 520 struct inode *i = f->f_mapping->host; 521 unsigned long long dev_size; 522 /* 523 * When using a file that references an underlying struct block_device, 524 * ensure dev_size is always based on the current inode size in order 525 * to handle underlying block_device resize operations. 526 */ 527 if (S_ISBLK(i->i_mode)) 528 dev_size = (i_size_read(i) - fd_dev->fd_block_size); 529 else 530 dev_size = fd_dev->fd_dev_size; 531 532 return div_u64(dev_size, dev->se_sub_dev->se_dev_attrib.block_size); 533 } 534 535 static struct spc_ops fd_spc_ops = { 536 .execute_rw = fd_execute_rw, 537 .execute_sync_cache = fd_execute_sync_cache, 538 }; 539 540 static int fd_parse_cdb(struct se_cmd *cmd) 541 { 542 return sbc_parse_cdb(cmd, &fd_spc_ops); 543 } 544 545 static struct se_subsystem_api fileio_template = { 546 .name = "fileio", 547 .owner = THIS_MODULE, 548 .transport_type = TRANSPORT_PLUGIN_VHBA_PDEV, 549 .write_cache_emulated = 1, 550 .fua_write_emulated = 1, 551 .attach_hba = fd_attach_hba, 552 .detach_hba = fd_detach_hba, 553 .allocate_virtdevice = fd_allocate_virtdevice, 554 .create_virtdevice = fd_create_virtdevice, 555 .free_device = fd_free_device, 556 .parse_cdb = fd_parse_cdb, 557 .check_configfs_dev_params = fd_check_configfs_dev_params, 558 .set_configfs_dev_params = fd_set_configfs_dev_params, 559 .show_configfs_dev_params = fd_show_configfs_dev_params, 560 .get_device_rev = fd_get_device_rev, 561 .get_device_type = fd_get_device_type, 562 .get_blocks = fd_get_blocks, 563 }; 564 565 static int __init fileio_module_init(void) 566 { 567 return transport_subsystem_register(&fileio_template); 568 } 569 570 static void fileio_module_exit(void) 571 { 572 transport_subsystem_release(&fileio_template); 573 } 574 575 MODULE_DESCRIPTION("TCM FILEIO subsystem plugin"); 576 MODULE_AUTHOR("nab@Linux-iSCSI.org"); 577 MODULE_LICENSE("GPL"); 578 579 module_init(fileio_module_init); 580 module_exit(fileio_module_exit); 581