1 /******************************************************************************* 2 * Filename: target_core_file.c 3 * 4 * This file contains the Storage Engine <-> FILEIO transport specific functions 5 * 6 * (c) Copyright 2005-2012 RisingTide Systems LLC. 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 <scsi/scsi.h> 34 #include <scsi/scsi_host.h> 35 36 #include <target/target_core_base.h> 37 #include <target/target_core_backend.h> 38 39 #include "target_core_file.h" 40 41 static inline struct fd_dev *FD_DEV(struct se_device *dev) 42 { 43 return container_of(dev, struct fd_dev, dev); 44 } 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 struct se_device *fd_alloc_device(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->dev; 101 } 102 103 static int fd_configure_device(struct se_device *dev) 104 { 105 struct fd_dev *fd_dev = FD_DEV(dev); 106 struct fd_host *fd_host = dev->se_hba->hba_ptr; 107 struct file *file; 108 struct inode *inode = NULL; 109 int flags, ret = -EINVAL; 110 111 if (!(fd_dev->fbd_flags & FBDF_HAS_PATH)) { 112 pr_err("Missing fd_dev_name=\n"); 113 return -EINVAL; 114 } 115 116 /* 117 * Use O_DSYNC by default instead of O_SYNC to forgo syncing 118 * of pure timestamp updates. 119 */ 120 flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC; 121 122 /* 123 * Optionally allow fd_buffered_io=1 to be enabled for people 124 * who want use the fs buffer cache as an WriteCache mechanism. 125 * 126 * This means that in event of a hard failure, there is a risk 127 * of silent data-loss if the SCSI client has *not* performed a 128 * forced unit access (FUA) write, or issued SYNCHRONIZE_CACHE 129 * to write-out the entire device cache. 130 */ 131 if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) { 132 pr_debug("FILEIO: Disabling O_DSYNC, using buffered FILEIO\n"); 133 flags &= ~O_DSYNC; 134 } 135 136 file = filp_open(fd_dev->fd_dev_name, flags, 0600); 137 if (IS_ERR(file)) { 138 pr_err("filp_open(%s) failed\n", fd_dev->fd_dev_name); 139 ret = PTR_ERR(file); 140 goto fail; 141 } 142 fd_dev->fd_file = file; 143 /* 144 * If using a block backend with this struct file, we extract 145 * fd_dev->fd_[block,dev]_size from struct block_device. 146 * 147 * Otherwise, we use the passed fd_size= from configfs 148 */ 149 inode = file->f_mapping->host; 150 if (S_ISBLK(inode->i_mode)) { 151 struct request_queue *q = bdev_get_queue(inode->i_bdev); 152 unsigned long long dev_size; 153 154 dev->dev_attrib.hw_block_size = 155 bdev_logical_block_size(inode->i_bdev); 156 dev->dev_attrib.hw_max_sectors = queue_max_hw_sectors(q); 157 158 /* 159 * Determine the number of bytes from i_size_read() minus 160 * one (1) logical sector from underlying struct block_device 161 */ 162 dev_size = (i_size_read(file->f_mapping->host) - 163 fd_dev->fd_block_size); 164 165 pr_debug("FILEIO: Using size: %llu bytes from struct" 166 " block_device blocks: %llu logical_block_size: %d\n", 167 dev_size, div_u64(dev_size, fd_dev->fd_block_size), 168 fd_dev->fd_block_size); 169 } else { 170 if (!(fd_dev->fbd_flags & FBDF_HAS_SIZE)) { 171 pr_err("FILEIO: Missing fd_dev_size=" 172 " parameter, and no backing struct" 173 " block_device\n"); 174 goto fail; 175 } 176 177 dev->dev_attrib.hw_block_size = FD_BLOCKSIZE; 178 dev->dev_attrib.hw_max_sectors = FD_MAX_SECTORS; 179 } 180 181 fd_dev->fd_block_size = dev->dev_attrib.hw_block_size; 182 183 dev->dev_attrib.hw_queue_depth = FD_MAX_DEVICE_QUEUE_DEPTH; 184 185 if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) { 186 pr_debug("FILEIO: Forcing setting of emulate_write_cache=1" 187 " with FDBD_HAS_BUFFERED_IO_WCE\n"); 188 dev->dev_attrib.emulate_write_cache = 1; 189 } 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 0; 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 ret; 205 } 206 207 static void fd_free_device(struct se_device *dev) 208 { 209 struct fd_dev *fd_dev = FD_DEV(dev); 210 211 if (fd_dev->fd_file) { 212 filp_close(fd_dev->fd_file, NULL); 213 fd_dev->fd_file = NULL; 214 } 215 216 kfree(fd_dev); 217 } 218 219 static int fd_do_rw(struct se_cmd *cmd, struct scatterlist *sgl, 220 u32 sgl_nents, int is_write) 221 { 222 struct se_device *se_dev = cmd->se_dev; 223 struct fd_dev *dev = FD_DEV(se_dev); 224 struct file *fd = dev->fd_file; 225 struct scatterlist *sg; 226 struct iovec *iov; 227 mm_segment_t old_fs; 228 loff_t pos = (cmd->t_task_lba * se_dev->dev_attrib.block_size); 229 int ret = 0, i; 230 231 iov = kzalloc(sizeof(struct iovec) * sgl_nents, GFP_KERNEL); 232 if (!iov) { 233 pr_err("Unable to allocate fd_do_readv iov[]\n"); 234 return -ENOMEM; 235 } 236 237 for_each_sg(sgl, sg, sgl_nents, i) { 238 iov[i].iov_len = sg->length; 239 iov[i].iov_base = kmap(sg_page(sg)) + sg->offset; 240 } 241 242 old_fs = get_fs(); 243 set_fs(get_ds()); 244 245 if (is_write) 246 ret = vfs_writev(fd, &iov[0], sgl_nents, &pos); 247 else 248 ret = vfs_readv(fd, &iov[0], sgl_nents, &pos); 249 250 set_fs(old_fs); 251 252 for_each_sg(sgl, sg, sgl_nents, i) 253 kunmap(sg_page(sg)); 254 255 kfree(iov); 256 257 if (is_write) { 258 if (ret < 0 || ret != cmd->data_length) { 259 pr_err("%s() write returned %d\n", __func__, ret); 260 return (ret < 0 ? ret : -EINVAL); 261 } 262 } else { 263 /* 264 * Return zeros and GOOD status even if the READ did not return 265 * the expected virt_size for struct file w/o a backing struct 266 * block_device. 267 */ 268 if (S_ISBLK(fd->f_dentry->d_inode->i_mode)) { 269 if (ret < 0 || ret != cmd->data_length) { 270 pr_err("%s() returned %d, expecting %u for " 271 "S_ISBLK\n", __func__, ret, 272 cmd->data_length); 273 return (ret < 0 ? ret : -EINVAL); 274 } 275 } else { 276 if (ret < 0) { 277 pr_err("%s() returned %d for non S_ISBLK\n", 278 __func__, ret); 279 return ret; 280 } 281 } 282 } 283 return 1; 284 } 285 286 static sense_reason_t 287 fd_execute_sync_cache(struct se_cmd *cmd) 288 { 289 struct se_device *dev = cmd->se_dev; 290 struct fd_dev *fd_dev = FD_DEV(dev); 291 int immed = (cmd->t_task_cdb[1] & 0x2); 292 loff_t start, end; 293 int ret; 294 295 /* 296 * If the Immediate bit is set, queue up the GOOD response 297 * for this SYNCHRONIZE_CACHE op 298 */ 299 if (immed) 300 target_complete_cmd(cmd, SAM_STAT_GOOD); 301 302 /* 303 * Determine if we will be flushing the entire device. 304 */ 305 if (cmd->t_task_lba == 0 && cmd->data_length == 0) { 306 start = 0; 307 end = LLONG_MAX; 308 } else { 309 start = cmd->t_task_lba * dev->dev_attrib.block_size; 310 if (cmd->data_length) 311 end = start + cmd->data_length; 312 else 313 end = LLONG_MAX; 314 } 315 316 ret = vfs_fsync_range(fd_dev->fd_file, start, end, 1); 317 if (ret != 0) 318 pr_err("FILEIO: vfs_fsync_range() failed: %d\n", ret); 319 320 if (immed) 321 return 0; 322 323 if (ret) 324 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION); 325 else 326 target_complete_cmd(cmd, SAM_STAT_GOOD); 327 328 return 0; 329 } 330 331 static sense_reason_t 332 fd_execute_rw(struct se_cmd *cmd) 333 { 334 struct scatterlist *sgl = cmd->t_data_sg; 335 u32 sgl_nents = cmd->t_data_nents; 336 enum dma_data_direction data_direction = cmd->data_direction; 337 struct se_device *dev = cmd->se_dev; 338 int ret = 0; 339 340 /* 341 * Call vectorized fileio functions to map struct scatterlist 342 * physical memory addresses to struct iovec virtual memory. 343 */ 344 if (data_direction == DMA_FROM_DEVICE) { 345 ret = fd_do_rw(cmd, sgl, sgl_nents, 0); 346 } else { 347 ret = fd_do_rw(cmd, sgl, sgl_nents, 1); 348 /* 349 * Perform implict vfs_fsync_range() for fd_do_writev() ops 350 * for SCSI WRITEs with Forced Unit Access (FUA) set. 351 * Allow this to happen independent of WCE=0 setting. 352 */ 353 if (ret > 0 && 354 dev->dev_attrib.emulate_fua_write > 0 && 355 (cmd->se_cmd_flags & SCF_FUA)) { 356 struct fd_dev *fd_dev = FD_DEV(dev); 357 loff_t start = cmd->t_task_lba * 358 dev->dev_attrib.block_size; 359 loff_t end = start + cmd->data_length; 360 361 vfs_fsync_range(fd_dev->fd_file, start, end, 1); 362 } 363 } 364 365 if (ret < 0) 366 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 367 368 if (ret) 369 target_complete_cmd(cmd, SAM_STAT_GOOD); 370 return 0; 371 } 372 373 enum { 374 Opt_fd_dev_name, Opt_fd_dev_size, Opt_fd_buffered_io, Opt_err 375 }; 376 377 static match_table_t tokens = { 378 {Opt_fd_dev_name, "fd_dev_name=%s"}, 379 {Opt_fd_dev_size, "fd_dev_size=%s"}, 380 {Opt_fd_buffered_io, "fd_buffered_io=%d"}, 381 {Opt_err, NULL} 382 }; 383 384 static ssize_t fd_set_configfs_dev_params(struct se_device *dev, 385 const char *page, ssize_t count) 386 { 387 struct fd_dev *fd_dev = FD_DEV(dev); 388 char *orig, *ptr, *arg_p, *opts; 389 substring_t args[MAX_OPT_ARGS]; 390 int ret = 0, arg, token; 391 392 opts = kstrdup(page, GFP_KERNEL); 393 if (!opts) 394 return -ENOMEM; 395 396 orig = opts; 397 398 while ((ptr = strsep(&opts, ",\n")) != NULL) { 399 if (!*ptr) 400 continue; 401 402 token = match_token(ptr, tokens, args); 403 switch (token) { 404 case Opt_fd_dev_name: 405 if (match_strlcpy(fd_dev->fd_dev_name, &args[0], 406 FD_MAX_DEV_NAME) == 0) { 407 ret = -EINVAL; 408 break; 409 } 410 pr_debug("FILEIO: Referencing Path: %s\n", 411 fd_dev->fd_dev_name); 412 fd_dev->fbd_flags |= FBDF_HAS_PATH; 413 break; 414 case Opt_fd_dev_size: 415 arg_p = match_strdup(&args[0]); 416 if (!arg_p) { 417 ret = -ENOMEM; 418 break; 419 } 420 ret = strict_strtoull(arg_p, 0, &fd_dev->fd_dev_size); 421 kfree(arg_p); 422 if (ret < 0) { 423 pr_err("strict_strtoull() failed for" 424 " fd_dev_size=\n"); 425 goto out; 426 } 427 pr_debug("FILEIO: Referencing Size: %llu" 428 " bytes\n", fd_dev->fd_dev_size); 429 fd_dev->fbd_flags |= FBDF_HAS_SIZE; 430 break; 431 case Opt_fd_buffered_io: 432 match_int(args, &arg); 433 if (arg != 1) { 434 pr_err("bogus fd_buffered_io=%d value\n", arg); 435 ret = -EINVAL; 436 goto out; 437 } 438 439 pr_debug("FILEIO: Using buffered I/O" 440 " operations for struct fd_dev\n"); 441 442 fd_dev->fbd_flags |= FDBD_HAS_BUFFERED_IO_WCE; 443 break; 444 default: 445 break; 446 } 447 } 448 449 out: 450 kfree(orig); 451 return (!ret) ? count : ret; 452 } 453 454 static ssize_t fd_show_configfs_dev_params(struct se_device *dev, char *b) 455 { 456 struct fd_dev *fd_dev = FD_DEV(dev); 457 ssize_t bl = 0; 458 459 bl = sprintf(b + bl, "TCM FILEIO ID: %u", fd_dev->fd_dev_id); 460 bl += sprintf(b + bl, " File: %s Size: %llu Mode: %s\n", 461 fd_dev->fd_dev_name, fd_dev->fd_dev_size, 462 (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) ? 463 "Buffered-WCE" : "O_DSYNC"); 464 return bl; 465 } 466 467 static sector_t fd_get_blocks(struct se_device *dev) 468 { 469 struct fd_dev *fd_dev = FD_DEV(dev); 470 struct file *f = fd_dev->fd_file; 471 struct inode *i = f->f_mapping->host; 472 unsigned long long dev_size; 473 /* 474 * When using a file that references an underlying struct block_device, 475 * ensure dev_size is always based on the current inode size in order 476 * to handle underlying block_device resize operations. 477 */ 478 if (S_ISBLK(i->i_mode)) 479 dev_size = (i_size_read(i) - fd_dev->fd_block_size); 480 else 481 dev_size = fd_dev->fd_dev_size; 482 483 return div_u64(dev_size, dev->dev_attrib.block_size); 484 } 485 486 static struct sbc_ops fd_sbc_ops = { 487 .execute_rw = fd_execute_rw, 488 .execute_sync_cache = fd_execute_sync_cache, 489 }; 490 491 static sense_reason_t 492 fd_parse_cdb(struct se_cmd *cmd) 493 { 494 return sbc_parse_cdb(cmd, &fd_sbc_ops); 495 } 496 497 static struct se_subsystem_api fileio_template = { 498 .name = "fileio", 499 .inquiry_prod = "FILEIO", 500 .inquiry_rev = FD_VERSION, 501 .owner = THIS_MODULE, 502 .transport_type = TRANSPORT_PLUGIN_VHBA_PDEV, 503 .attach_hba = fd_attach_hba, 504 .detach_hba = fd_detach_hba, 505 .alloc_device = fd_alloc_device, 506 .configure_device = fd_configure_device, 507 .free_device = fd_free_device, 508 .parse_cdb = fd_parse_cdb, 509 .set_configfs_dev_params = fd_set_configfs_dev_params, 510 .show_configfs_dev_params = fd_show_configfs_dev_params, 511 .get_device_type = sbc_get_device_type, 512 .get_blocks = fd_get_blocks, 513 }; 514 515 static int __init fileio_module_init(void) 516 { 517 return transport_subsystem_register(&fileio_template); 518 } 519 520 static void fileio_module_exit(void) 521 { 522 transport_subsystem_release(&fileio_template); 523 } 524 525 MODULE_DESCRIPTION("TCM FILEIO subsystem plugin"); 526 MODULE_AUTHOR("nab@Linux-iSCSI.org"); 527 MODULE_LICENSE("GPL"); 528 529 module_init(fileio_module_init); 530 module_exit(fileio_module_exit); 531