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/version.h>
30 #include <linux/string.h>
31 #include <linux/parser.h>
32 #include <linux/timer.h>
33 #include <linux/blkdev.h>
34 #include <linux/slab.h>
35 #include <linux/spinlock.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_device.h>
41 #include <target/target_core_transport.h>
42 
43 #include "target_core_file.h"
44 
45 #if 1
46 #define DEBUG_FD_CACHE(x...) printk(x)
47 #else
48 #define DEBUG_FD_CACHE(x...)
49 #endif
50 
51 #if 1
52 #define DEBUG_FD_FUA(x...) printk(x)
53 #else
54 #define DEBUG_FD_FUA(x...)
55 #endif
56 
57 static struct se_subsystem_api fileio_template;
58 
59 /*	fd_attach_hba(): (Part of se_subsystem_api_t template)
60  *
61  *
62  */
63 static int fd_attach_hba(struct se_hba *hba, u32 host_id)
64 {
65 	struct fd_host *fd_host;
66 
67 	fd_host = kzalloc(sizeof(struct fd_host), GFP_KERNEL);
68 	if (!(fd_host)) {
69 		printk(KERN_ERR "Unable to allocate memory for struct fd_host\n");
70 		return -1;
71 	}
72 
73 	fd_host->fd_host_id = host_id;
74 
75 	atomic_set(&hba->left_queue_depth, FD_HBA_QUEUE_DEPTH);
76 	atomic_set(&hba->max_queue_depth, FD_HBA_QUEUE_DEPTH);
77 	hba->hba_ptr = (void *) fd_host;
78 
79 	printk(KERN_INFO "CORE_HBA[%d] - TCM FILEIO HBA Driver %s on Generic"
80 		" Target Core Stack %s\n", hba->hba_id, FD_VERSION,
81 		TARGET_CORE_MOD_VERSION);
82 	printk(KERN_INFO "CORE_HBA[%d] - Attached FILEIO HBA: %u to Generic"
83 		" Target Core with TCQ Depth: %d MaxSectors: %u\n",
84 		hba->hba_id, fd_host->fd_host_id,
85 		atomic_read(&hba->max_queue_depth), FD_MAX_SECTORS);
86 
87 	return 0;
88 }
89 
90 static void fd_detach_hba(struct se_hba *hba)
91 {
92 	struct fd_host *fd_host = hba->hba_ptr;
93 
94 	printk(KERN_INFO "CORE_HBA[%d] - Detached FILEIO HBA: %u from Generic"
95 		" Target Core\n", hba->hba_id, fd_host->fd_host_id);
96 
97 	kfree(fd_host);
98 	hba->hba_ptr = NULL;
99 }
100 
101 static void *fd_allocate_virtdevice(struct se_hba *hba, const char *name)
102 {
103 	struct fd_dev *fd_dev;
104 	struct fd_host *fd_host = (struct fd_host *) hba->hba_ptr;
105 
106 	fd_dev = kzalloc(sizeof(struct fd_dev), GFP_KERNEL);
107 	if (!(fd_dev)) {
108 		printk(KERN_ERR "Unable to allocate memory for struct fd_dev\n");
109 		return NULL;
110 	}
111 
112 	fd_dev->fd_host = fd_host;
113 
114 	printk(KERN_INFO "FILEIO: Allocated fd_dev for %p\n", name);
115 
116 	return fd_dev;
117 }
118 
119 /*	fd_create_virtdevice(): (Part of se_subsystem_api_t template)
120  *
121  *
122  */
123 static struct se_device *fd_create_virtdevice(
124 	struct se_hba *hba,
125 	struct se_subsystem_dev *se_dev,
126 	void *p)
127 {
128 	char *dev_p = NULL;
129 	struct se_device *dev;
130 	struct se_dev_limits dev_limits;
131 	struct queue_limits *limits;
132 	struct fd_dev *fd_dev = (struct fd_dev *) p;
133 	struct fd_host *fd_host = (struct fd_host *) hba->hba_ptr;
134 	mm_segment_t old_fs;
135 	struct file *file;
136 	struct inode *inode = NULL;
137 	int dev_flags = 0, flags;
138 
139 	memset(&dev_limits, 0, sizeof(struct se_dev_limits));
140 
141 	old_fs = get_fs();
142 	set_fs(get_ds());
143 	dev_p = getname(fd_dev->fd_dev_name);
144 	set_fs(old_fs);
145 
146 	if (IS_ERR(dev_p)) {
147 		printk(KERN_ERR "getname(%s) failed: %lu\n",
148 			fd_dev->fd_dev_name, IS_ERR(dev_p));
149 		goto fail;
150 	}
151 #if 0
152 	if (di->no_create_file)
153 		flags = O_RDWR | O_LARGEFILE;
154 	else
155 		flags = O_RDWR | O_CREAT | O_LARGEFILE;
156 #else
157 	flags = O_RDWR | O_CREAT | O_LARGEFILE;
158 #endif
159 /*	flags |= O_DIRECT; */
160 	/*
161 	 * If fd_buffered_io=1 has not been set explictly (the default),
162 	 * use O_SYNC to force FILEIO writes to disk.
163 	 */
164 	if (!(fd_dev->fbd_flags & FDBD_USE_BUFFERED_IO))
165 		flags |= O_SYNC;
166 
167 	file = filp_open(dev_p, flags, 0600);
168 
169 	if (IS_ERR(file) || !file || !file->f_dentry) {
170 		printk(KERN_ERR "filp_open(%s) failed\n", dev_p);
171 		goto fail;
172 	}
173 	fd_dev->fd_file = file;
174 	/*
175 	 * If using a block backend with this struct file, we extract
176 	 * fd_dev->fd_[block,dev]_size from struct block_device.
177 	 *
178 	 * Otherwise, we use the passed fd_size= from configfs
179 	 */
180 	inode = file->f_mapping->host;
181 	if (S_ISBLK(inode->i_mode)) {
182 		struct request_queue *q;
183 		/*
184 		 * Setup the local scope queue_limits from struct request_queue->limits
185 		 * to pass into transport_add_device_to_core_hba() as struct se_dev_limits.
186 		 */
187 		q = bdev_get_queue(inode->i_bdev);
188 		limits = &dev_limits.limits;
189 		limits->logical_block_size = bdev_logical_block_size(inode->i_bdev);
190 		limits->max_hw_sectors = queue_max_hw_sectors(q);
191 		limits->max_sectors = queue_max_sectors(q);
192 		/*
193 		 * Determine the number of bytes from i_size_read() minus
194 		 * one (1) logical sector from underlying struct block_device
195 		 */
196 		fd_dev->fd_block_size = bdev_logical_block_size(inode->i_bdev);
197 		fd_dev->fd_dev_size = (i_size_read(file->f_mapping->host) -
198 				       fd_dev->fd_block_size);
199 
200 		printk(KERN_INFO "FILEIO: Using size: %llu bytes from struct"
201 			" block_device blocks: %llu logical_block_size: %d\n",
202 			fd_dev->fd_dev_size,
203 			div_u64(fd_dev->fd_dev_size, fd_dev->fd_block_size),
204 			fd_dev->fd_block_size);
205 	} else {
206 		if (!(fd_dev->fbd_flags & FBDF_HAS_SIZE)) {
207 			printk(KERN_ERR "FILEIO: Missing fd_dev_size="
208 				" parameter, and no backing struct"
209 				" block_device\n");
210 			goto fail;
211 		}
212 
213 		limits = &dev_limits.limits;
214 		limits->logical_block_size = FD_BLOCKSIZE;
215 		limits->max_hw_sectors = FD_MAX_SECTORS;
216 		limits->max_sectors = FD_MAX_SECTORS;
217 		fd_dev->fd_block_size = FD_BLOCKSIZE;
218 	}
219 
220 	dev_limits.hw_queue_depth = FD_MAX_DEVICE_QUEUE_DEPTH;
221 	dev_limits.queue_depth = FD_DEVICE_QUEUE_DEPTH;
222 
223 	dev = transport_add_device_to_core_hba(hba, &fileio_template,
224 				se_dev, dev_flags, (void *)fd_dev,
225 				&dev_limits, "FILEIO", FD_VERSION);
226 	if (!(dev))
227 		goto fail;
228 
229 	fd_dev->fd_dev_id = fd_host->fd_host_dev_id_count++;
230 	fd_dev->fd_queue_depth = dev->queue_depth;
231 
232 	printk(KERN_INFO "CORE_FILE[%u] - Added TCM FILEIO Device ID: %u at %s,"
233 		" %llu total bytes\n", fd_host->fd_host_id, fd_dev->fd_dev_id,
234 			fd_dev->fd_dev_name, fd_dev->fd_dev_size);
235 
236 	putname(dev_p);
237 	return dev;
238 fail:
239 	if (fd_dev->fd_file) {
240 		filp_close(fd_dev->fd_file, NULL);
241 		fd_dev->fd_file = NULL;
242 	}
243 	putname(dev_p);
244 	return NULL;
245 }
246 
247 /*	fd_free_device(): (Part of se_subsystem_api_t template)
248  *
249  *
250  */
251 static void fd_free_device(void *p)
252 {
253 	struct fd_dev *fd_dev = (struct fd_dev *) p;
254 
255 	if (fd_dev->fd_file) {
256 		filp_close(fd_dev->fd_file, NULL);
257 		fd_dev->fd_file = NULL;
258 	}
259 
260 	kfree(fd_dev);
261 }
262 
263 static inline struct fd_request *FILE_REQ(struct se_task *task)
264 {
265 	return container_of(task, struct fd_request, fd_task);
266 }
267 
268 
269 static struct se_task *
270 fd_alloc_task(struct se_cmd *cmd)
271 {
272 	struct fd_request *fd_req;
273 
274 	fd_req = kzalloc(sizeof(struct fd_request), GFP_KERNEL);
275 	if (!(fd_req)) {
276 		printk(KERN_ERR "Unable to allocate struct fd_request\n");
277 		return NULL;
278 	}
279 
280 	fd_req->fd_dev = SE_DEV(cmd)->dev_ptr;
281 
282 	return &fd_req->fd_task;
283 }
284 
285 static int fd_do_readv(struct se_task *task)
286 {
287 	struct fd_request *req = FILE_REQ(task);
288 	struct file *fd = req->fd_dev->fd_file;
289 	struct scatterlist *sg = task->task_sg;
290 	struct iovec *iov;
291 	mm_segment_t old_fs;
292 	loff_t pos = (task->task_lba * DEV_ATTRIB(task->se_dev)->block_size);
293 	int ret = 0, i;
294 
295 	iov = kzalloc(sizeof(struct iovec) * task->task_sg_num, GFP_KERNEL);
296 	if (!(iov)) {
297 		printk(KERN_ERR "Unable to allocate fd_do_readv iov[]\n");
298 		return -1;
299 	}
300 
301 	for (i = 0; i < task->task_sg_num; i++) {
302 		iov[i].iov_len = sg[i].length;
303 		iov[i].iov_base = sg_virt(&sg[i]);
304 	}
305 
306 	old_fs = get_fs();
307 	set_fs(get_ds());
308 	ret = vfs_readv(fd, &iov[0], task->task_sg_num, &pos);
309 	set_fs(old_fs);
310 
311 	kfree(iov);
312 	/*
313 	 * Return zeros and GOOD status even if the READ did not return
314 	 * the expected virt_size for struct file w/o a backing struct
315 	 * block_device.
316 	 */
317 	if (S_ISBLK(fd->f_dentry->d_inode->i_mode)) {
318 		if (ret < 0 || ret != task->task_size) {
319 			printk(KERN_ERR "vfs_readv() returned %d,"
320 				" expecting %d for S_ISBLK\n", ret,
321 				(int)task->task_size);
322 			return -1;
323 		}
324 	} else {
325 		if (ret < 0) {
326 			printk(KERN_ERR "vfs_readv() returned %d for non"
327 				" S_ISBLK\n", ret);
328 			return -1;
329 		}
330 	}
331 
332 	return 1;
333 }
334 
335 static int fd_do_writev(struct se_task *task)
336 {
337 	struct fd_request *req = FILE_REQ(task);
338 	struct file *fd = req->fd_dev->fd_file;
339 	struct scatterlist *sg = task->task_sg;
340 	struct iovec *iov;
341 	mm_segment_t old_fs;
342 	loff_t pos = (task->task_lba * DEV_ATTRIB(task->se_dev)->block_size);
343 	int ret, i = 0;
344 
345 	iov = kzalloc(sizeof(struct iovec) * task->task_sg_num, GFP_KERNEL);
346 	if (!(iov)) {
347 		printk(KERN_ERR "Unable to allocate fd_do_writev iov[]\n");
348 		return -1;
349 	}
350 
351 	for (i = 0; i < task->task_sg_num; i++) {
352 		iov[i].iov_len = sg[i].length;
353 		iov[i].iov_base = sg_virt(&sg[i]);
354 	}
355 
356 	old_fs = get_fs();
357 	set_fs(get_ds());
358 	ret = vfs_writev(fd, &iov[0], task->task_sg_num, &pos);
359 	set_fs(old_fs);
360 
361 	kfree(iov);
362 
363 	if (ret < 0 || ret != task->task_size) {
364 		printk(KERN_ERR "vfs_writev() returned %d\n", ret);
365 		return -1;
366 	}
367 
368 	return 1;
369 }
370 
371 static void fd_emulate_sync_cache(struct se_task *task)
372 {
373 	struct se_cmd *cmd = TASK_CMD(task);
374 	struct se_device *dev = cmd->se_dev;
375 	struct fd_dev *fd_dev = dev->dev_ptr;
376 	int immed = (cmd->t_task->t_task_cdb[1] & 0x2);
377 	loff_t start, end;
378 	int ret;
379 
380 	/*
381 	 * If the Immediate bit is set, queue up the GOOD response
382 	 * for this SYNCHRONIZE_CACHE op
383 	 */
384 	if (immed)
385 		transport_complete_sync_cache(cmd, 1);
386 
387 	/*
388 	 * Determine if we will be flushing the entire device.
389 	 */
390 	if (cmd->t_task->t_task_lba == 0 && cmd->data_length == 0) {
391 		start = 0;
392 		end = LLONG_MAX;
393 	} else {
394 		start = cmd->t_task->t_task_lba * DEV_ATTRIB(dev)->block_size;
395 		if (cmd->data_length)
396 			end = start + cmd->data_length;
397 		else
398 			end = LLONG_MAX;
399 	}
400 
401 	ret = vfs_fsync_range(fd_dev->fd_file, start, end, 1);
402 	if (ret != 0)
403 		printk(KERN_ERR "FILEIO: vfs_fsync_range() failed: %d\n", ret);
404 
405 	if (!immed)
406 		transport_complete_sync_cache(cmd, ret == 0);
407 }
408 
409 /*
410  * Tell TCM Core that we are capable of WriteCache emulation for
411  * an underlying struct se_device.
412  */
413 static int fd_emulated_write_cache(struct se_device *dev)
414 {
415 	return 1;
416 }
417 
418 static int fd_emulated_dpo(struct se_device *dev)
419 {
420 	return 0;
421 }
422 /*
423  * Tell TCM Core that we will be emulating Forced Unit Access (FUA) for WRITEs
424  * for TYPE_DISK.
425  */
426 static int fd_emulated_fua_write(struct se_device *dev)
427 {
428 	return 1;
429 }
430 
431 static int fd_emulated_fua_read(struct se_device *dev)
432 {
433 	return 0;
434 }
435 
436 /*
437  * WRITE Force Unit Access (FUA) emulation on a per struct se_task
438  * LBA range basis..
439  */
440 static void fd_emulate_write_fua(struct se_cmd *cmd, struct se_task *task)
441 {
442 	struct se_device *dev = cmd->se_dev;
443 	struct fd_dev *fd_dev = dev->dev_ptr;
444 	loff_t start = task->task_lba * DEV_ATTRIB(dev)->block_size;
445 	loff_t end = start + task->task_size;
446 	int ret;
447 
448 	DEBUG_FD_CACHE("FILEIO: FUA WRITE LBA: %llu, bytes: %u\n",
449 			task->task_lba, task->task_size);
450 
451 	ret = vfs_fsync_range(fd_dev->fd_file, start, end, 1);
452 	if (ret != 0)
453 		printk(KERN_ERR "FILEIO: vfs_fsync_range() failed: %d\n", ret);
454 }
455 
456 static int fd_do_task(struct se_task *task)
457 {
458 	struct se_cmd *cmd = task->task_se_cmd;
459 	struct se_device *dev = cmd->se_dev;
460 	int ret = 0;
461 
462 	/*
463 	 * Call vectorized fileio functions to map struct scatterlist
464 	 * physical memory addresses to struct iovec virtual memory.
465 	 */
466 	if (task->task_data_direction == DMA_FROM_DEVICE) {
467 		ret = fd_do_readv(task);
468 	} else {
469 		ret = fd_do_writev(task);
470 
471 		if (ret > 0 &&
472 		    DEV_ATTRIB(dev)->emulate_write_cache > 0 &&
473 		    DEV_ATTRIB(dev)->emulate_fua_write > 0 &&
474 		    T_TASK(cmd)->t_tasks_fua) {
475 			/*
476 			 * We might need to be a bit smarter here
477 			 * and return some sense data to let the initiator
478 			 * know the FUA WRITE cache sync failed..?
479 			 */
480 			fd_emulate_write_fua(cmd, task);
481 		}
482 
483 	}
484 
485 	if (ret < 0)
486 		return ret;
487 	if (ret) {
488 		task->task_scsi_status = GOOD;
489 		transport_complete_task(task, 1);
490 	}
491 	return PYX_TRANSPORT_SENT_TO_TRANSPORT;
492 }
493 
494 /*	fd_free_task(): (Part of se_subsystem_api_t template)
495  *
496  *
497  */
498 static void fd_free_task(struct se_task *task)
499 {
500 	struct fd_request *req = FILE_REQ(task);
501 
502 	kfree(req);
503 }
504 
505 enum {
506 	Opt_fd_dev_name, Opt_fd_dev_size, Opt_fd_buffered_io, Opt_err
507 };
508 
509 static match_table_t tokens = {
510 	{Opt_fd_dev_name, "fd_dev_name=%s"},
511 	{Opt_fd_dev_size, "fd_dev_size=%s"},
512 	{Opt_fd_buffered_io, "fd_buffered_id=%d"},
513 	{Opt_err, NULL}
514 };
515 
516 static ssize_t fd_set_configfs_dev_params(
517 	struct se_hba *hba,
518 	struct se_subsystem_dev *se_dev,
519 	const char *page, ssize_t count)
520 {
521 	struct fd_dev *fd_dev = se_dev->se_dev_su_ptr;
522 	char *orig, *ptr, *arg_p, *opts;
523 	substring_t args[MAX_OPT_ARGS];
524 	int ret = 0, arg, token;
525 
526 	opts = kstrdup(page, GFP_KERNEL);
527 	if (!opts)
528 		return -ENOMEM;
529 
530 	orig = opts;
531 
532 	while ((ptr = strsep(&opts, ",")) != NULL) {
533 		if (!*ptr)
534 			continue;
535 
536 		token = match_token(ptr, tokens, args);
537 		switch (token) {
538 		case Opt_fd_dev_name:
539 			snprintf(fd_dev->fd_dev_name, FD_MAX_DEV_NAME,
540 					"%s", match_strdup(&args[0]));
541 			printk(KERN_INFO "FILEIO: Referencing Path: %s\n",
542 					fd_dev->fd_dev_name);
543 			fd_dev->fbd_flags |= FBDF_HAS_PATH;
544 			break;
545 		case Opt_fd_dev_size:
546 			arg_p = match_strdup(&args[0]);
547 			ret = strict_strtoull(arg_p, 0, &fd_dev->fd_dev_size);
548 			if (ret < 0) {
549 				printk(KERN_ERR "strict_strtoull() failed for"
550 						" fd_dev_size=\n");
551 				goto out;
552 			}
553 			printk(KERN_INFO "FILEIO: Referencing Size: %llu"
554 					" bytes\n", fd_dev->fd_dev_size);
555 			fd_dev->fbd_flags |= FBDF_HAS_SIZE;
556 			break;
557 		case Opt_fd_buffered_io:
558 			match_int(args, &arg);
559 			if (arg != 1) {
560 				printk(KERN_ERR "bogus fd_buffered_io=%d value\n", arg);
561 				ret = -EINVAL;
562 				goto out;
563 			}
564 
565 			printk(KERN_INFO "FILEIO: Using buffered I/O"
566 				" operations for struct fd_dev\n");
567 
568 			fd_dev->fbd_flags |= FDBD_USE_BUFFERED_IO;
569 			break;
570 		default:
571 			break;
572 		}
573 	}
574 
575 out:
576 	kfree(orig);
577 	return (!ret) ? count : ret;
578 }
579 
580 static ssize_t fd_check_configfs_dev_params(struct se_hba *hba, struct se_subsystem_dev *se_dev)
581 {
582 	struct fd_dev *fd_dev = (struct fd_dev *) se_dev->se_dev_su_ptr;
583 
584 	if (!(fd_dev->fbd_flags & FBDF_HAS_PATH)) {
585 		printk(KERN_ERR "Missing fd_dev_name=\n");
586 		return -1;
587 	}
588 
589 	return 0;
590 }
591 
592 static ssize_t fd_show_configfs_dev_params(
593 	struct se_hba *hba,
594 	struct se_subsystem_dev *se_dev,
595 	char *b)
596 {
597 	struct fd_dev *fd_dev = se_dev->se_dev_su_ptr;
598 	ssize_t bl = 0;
599 
600 	bl = sprintf(b + bl, "TCM FILEIO ID: %u", fd_dev->fd_dev_id);
601 	bl += sprintf(b + bl, "        File: %s  Size: %llu  Mode: %s\n",
602 		fd_dev->fd_dev_name, fd_dev->fd_dev_size,
603 		(fd_dev->fbd_flags & FDBD_USE_BUFFERED_IO) ?
604 		"Buffered" : "Synchronous");
605 	return bl;
606 }
607 
608 /*	fd_get_cdb(): (Part of se_subsystem_api_t template)
609  *
610  *
611  */
612 static unsigned char *fd_get_cdb(struct se_task *task)
613 {
614 	struct fd_request *req = FILE_REQ(task);
615 
616 	return req->fd_scsi_cdb;
617 }
618 
619 /*	fd_get_device_rev(): (Part of se_subsystem_api_t template)
620  *
621  *
622  */
623 static u32 fd_get_device_rev(struct se_device *dev)
624 {
625 	return SCSI_SPC_2; /* Returns SPC-3 in Initiator Data */
626 }
627 
628 /*	fd_get_device_type(): (Part of se_subsystem_api_t template)
629  *
630  *
631  */
632 static u32 fd_get_device_type(struct se_device *dev)
633 {
634 	return TYPE_DISK;
635 }
636 
637 static sector_t fd_get_blocks(struct se_device *dev)
638 {
639 	struct fd_dev *fd_dev = dev->dev_ptr;
640 	unsigned long long blocks_long = div_u64(fd_dev->fd_dev_size,
641 			DEV_ATTRIB(dev)->block_size);
642 
643 	return blocks_long;
644 }
645 
646 static struct se_subsystem_api fileio_template = {
647 	.name			= "fileio",
648 	.owner			= THIS_MODULE,
649 	.transport_type		= TRANSPORT_PLUGIN_VHBA_PDEV,
650 	.attach_hba		= fd_attach_hba,
651 	.detach_hba		= fd_detach_hba,
652 	.allocate_virtdevice	= fd_allocate_virtdevice,
653 	.create_virtdevice	= fd_create_virtdevice,
654 	.free_device		= fd_free_device,
655 	.dpo_emulated		= fd_emulated_dpo,
656 	.fua_write_emulated	= fd_emulated_fua_write,
657 	.fua_read_emulated	= fd_emulated_fua_read,
658 	.write_cache_emulated	= fd_emulated_write_cache,
659 	.alloc_task		= fd_alloc_task,
660 	.do_task		= fd_do_task,
661 	.do_sync_cache		= fd_emulate_sync_cache,
662 	.free_task		= fd_free_task,
663 	.check_configfs_dev_params = fd_check_configfs_dev_params,
664 	.set_configfs_dev_params = fd_set_configfs_dev_params,
665 	.show_configfs_dev_params = fd_show_configfs_dev_params,
666 	.get_cdb		= fd_get_cdb,
667 	.get_device_rev		= fd_get_device_rev,
668 	.get_device_type	= fd_get_device_type,
669 	.get_blocks		= fd_get_blocks,
670 };
671 
672 static int __init fileio_module_init(void)
673 {
674 	return transport_subsystem_register(&fileio_template);
675 }
676 
677 static void fileio_module_exit(void)
678 {
679 	transport_subsystem_release(&fileio_template);
680 }
681 
682 MODULE_DESCRIPTION("TCM FILEIO subsystem plugin");
683 MODULE_AUTHOR("nab@Linux-iSCSI.org");
684 MODULE_LICENSE("GPL");
685 
686 module_init(fileio_module_init);
687 module_exit(fileio_module_exit);
688