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 <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 
41 #include "target_core_file.h"
42 
43 static inline struct fd_dev *FD_DEV(struct se_device *dev)
44 {
45 	return container_of(dev, struct fd_dev, dev);
46 }
47 
48 /*	fd_attach_hba(): (Part of se_subsystem_api_t template)
49  *
50  *
51  */
52 static int fd_attach_hba(struct se_hba *hba, u32 host_id)
53 {
54 	struct fd_host *fd_host;
55 
56 	fd_host = kzalloc(sizeof(struct fd_host), GFP_KERNEL);
57 	if (!fd_host) {
58 		pr_err("Unable to allocate memory for struct fd_host\n");
59 		return -ENOMEM;
60 	}
61 
62 	fd_host->fd_host_id = host_id;
63 
64 	hba->hba_ptr = fd_host;
65 
66 	pr_debug("CORE_HBA[%d] - TCM FILEIO HBA Driver %s on Generic"
67 		" Target Core Stack %s\n", hba->hba_id, FD_VERSION,
68 		TARGET_CORE_MOD_VERSION);
69 	pr_debug("CORE_HBA[%d] - Attached FILEIO HBA: %u to Generic"
70 		" MaxSectors: %u\n",
71 		hba->hba_id, fd_host->fd_host_id, FD_MAX_SECTORS);
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 		dev->dev_attrib.hw_block_size =
157 			bdev_logical_block_size(inode->i_bdev);
158 		dev->dev_attrib.hw_max_sectors = queue_max_hw_sectors(q);
159 
160 		/*
161 		 * Determine the number of bytes from i_size_read() minus
162 		 * one (1) logical sector from underlying struct block_device
163 		 */
164 		dev_size = (i_size_read(file->f_mapping->host) -
165 				       fd_dev->fd_block_size);
166 
167 		pr_debug("FILEIO: Using size: %llu bytes from struct"
168 			" block_device blocks: %llu logical_block_size: %d\n",
169 			dev_size, div_u64(dev_size, fd_dev->fd_block_size),
170 			fd_dev->fd_block_size);
171 		/*
172 		 * Check if the underlying struct block_device request_queue supports
173 		 * the QUEUE_FLAG_DISCARD bit for UNMAP/WRITE_SAME in SCSI + TRIM
174 		 * in ATA and we need to set TPE=1
175 		 */
176 		if (blk_queue_discard(q)) {
177 			dev->dev_attrib.max_unmap_lba_count =
178 				q->limits.max_discard_sectors;
179 			/*
180 			 * Currently hardcoded to 1 in Linux/SCSI code..
181 			 */
182 			dev->dev_attrib.max_unmap_block_desc_count = 1;
183 			dev->dev_attrib.unmap_granularity =
184 				q->limits.discard_granularity >> 9;
185 			dev->dev_attrib.unmap_granularity_alignment =
186 				q->limits.discard_alignment;
187 			pr_debug("IFILE: BLOCK Discard support available,"
188 					" disabled by default\n");
189 		}
190 		/*
191 		 * Enable write same emulation for IBLOCK and use 0xFFFF as
192 		 * the smaller WRITE_SAME(10) only has a two-byte block count.
193 		 */
194 		dev->dev_attrib.max_write_same_len = 0xFFFF;
195 
196 		if (blk_queue_nonrot(q))
197 			dev->dev_attrib.is_nonrot = 1;
198 	} else {
199 		if (!(fd_dev->fbd_flags & FBDF_HAS_SIZE)) {
200 			pr_err("FILEIO: Missing fd_dev_size="
201 				" parameter, and no backing struct"
202 				" block_device\n");
203 			goto fail;
204 		}
205 
206 		dev->dev_attrib.hw_block_size = FD_BLOCKSIZE;
207 		dev->dev_attrib.hw_max_sectors = FD_MAX_SECTORS;
208 
209 		/*
210 		 * Limit UNMAP emulation to 8k Number of LBAs (NoLB)
211 		 */
212 		dev->dev_attrib.max_unmap_lba_count = 0x2000;
213 		/*
214 		 * Currently hardcoded to 1 in Linux/SCSI code..
215 		 */
216 		dev->dev_attrib.max_unmap_block_desc_count = 1;
217 		dev->dev_attrib.unmap_granularity = 1;
218 		dev->dev_attrib.unmap_granularity_alignment = 0;
219 
220 		/*
221 		 * Limit WRITE_SAME w/ UNMAP=0 emulation to 8k Number of LBAs (NoLB)
222 		 * based upon struct iovec limit for vfs_writev()
223 		 */
224 		dev->dev_attrib.max_write_same_len = 0x1000;
225 	}
226 
227 	fd_dev->fd_block_size = dev->dev_attrib.hw_block_size;
228 
229 	dev->dev_attrib.hw_queue_depth = FD_MAX_DEVICE_QUEUE_DEPTH;
230 
231 	if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
232 		pr_debug("FILEIO: Forcing setting of emulate_write_cache=1"
233 			" with FDBD_HAS_BUFFERED_IO_WCE\n");
234 		dev->dev_attrib.emulate_write_cache = 1;
235 	}
236 
237 	fd_dev->fd_dev_id = fd_host->fd_host_dev_id_count++;
238 	fd_dev->fd_queue_depth = dev->queue_depth;
239 
240 	pr_debug("CORE_FILE[%u] - Added TCM FILEIO Device ID: %u at %s,"
241 		" %llu total bytes\n", fd_host->fd_host_id, fd_dev->fd_dev_id,
242 			fd_dev->fd_dev_name, fd_dev->fd_dev_size);
243 
244 	return 0;
245 fail:
246 	if (fd_dev->fd_file) {
247 		filp_close(fd_dev->fd_file, NULL);
248 		fd_dev->fd_file = NULL;
249 	}
250 	return ret;
251 }
252 
253 static void fd_free_device(struct se_device *dev)
254 {
255 	struct fd_dev *fd_dev = FD_DEV(dev);
256 
257 	if (fd_dev->fd_file) {
258 		filp_close(fd_dev->fd_file, NULL);
259 		fd_dev->fd_file = NULL;
260 	}
261 
262 	kfree(fd_dev);
263 }
264 
265 static int fd_do_rw(struct se_cmd *cmd, struct scatterlist *sgl,
266 		u32 sgl_nents, int is_write)
267 {
268 	struct se_device *se_dev = cmd->se_dev;
269 	struct fd_dev *dev = FD_DEV(se_dev);
270 	struct file *fd = dev->fd_file;
271 	struct scatterlist *sg;
272 	struct iovec *iov;
273 	mm_segment_t old_fs;
274 	loff_t pos = (cmd->t_task_lba * se_dev->dev_attrib.block_size);
275 	int ret = 0, i;
276 
277 	iov = kzalloc(sizeof(struct iovec) * sgl_nents, GFP_KERNEL);
278 	if (!iov) {
279 		pr_err("Unable to allocate fd_do_readv iov[]\n");
280 		return -ENOMEM;
281 	}
282 
283 	for_each_sg(sgl, sg, sgl_nents, i) {
284 		iov[i].iov_len = sg->length;
285 		iov[i].iov_base = kmap(sg_page(sg)) + sg->offset;
286 	}
287 
288 	old_fs = get_fs();
289 	set_fs(get_ds());
290 
291 	if (is_write)
292 		ret = vfs_writev(fd, &iov[0], sgl_nents, &pos);
293 	else
294 		ret = vfs_readv(fd, &iov[0], sgl_nents, &pos);
295 
296 	set_fs(old_fs);
297 
298 	for_each_sg(sgl, sg, sgl_nents, i)
299 		kunmap(sg_page(sg));
300 
301 	kfree(iov);
302 
303 	if (is_write) {
304 		if (ret < 0 || ret != cmd->data_length) {
305 			pr_err("%s() write returned %d\n", __func__, ret);
306 			return (ret < 0 ? ret : -EINVAL);
307 		}
308 	} else {
309 		/*
310 		 * Return zeros and GOOD status even if the READ did not return
311 		 * the expected virt_size for struct file w/o a backing struct
312 		 * block_device.
313 		 */
314 		if (S_ISBLK(file_inode(fd)->i_mode)) {
315 			if (ret < 0 || ret != cmd->data_length) {
316 				pr_err("%s() returned %d, expecting %u for "
317 						"S_ISBLK\n", __func__, ret,
318 						cmd->data_length);
319 				return (ret < 0 ? ret : -EINVAL);
320 			}
321 		} else {
322 			if (ret < 0) {
323 				pr_err("%s() returned %d for non S_ISBLK\n",
324 						__func__, ret);
325 				return ret;
326 			}
327 		}
328 	}
329 	return 1;
330 }
331 
332 static sense_reason_t
333 fd_execute_sync_cache(struct se_cmd *cmd)
334 {
335 	struct se_device *dev = cmd->se_dev;
336 	struct fd_dev *fd_dev = FD_DEV(dev);
337 	int immed = (cmd->t_task_cdb[1] & 0x2);
338 	loff_t start, end;
339 	int ret;
340 
341 	/*
342 	 * If the Immediate bit is set, queue up the GOOD response
343 	 * for this SYNCHRONIZE_CACHE op
344 	 */
345 	if (immed)
346 		target_complete_cmd(cmd, SAM_STAT_GOOD);
347 
348 	/*
349 	 * Determine if we will be flushing the entire device.
350 	 */
351 	if (cmd->t_task_lba == 0 && cmd->data_length == 0) {
352 		start = 0;
353 		end = LLONG_MAX;
354 	} else {
355 		start = cmd->t_task_lba * dev->dev_attrib.block_size;
356 		if (cmd->data_length)
357 			end = start + cmd->data_length;
358 		else
359 			end = LLONG_MAX;
360 	}
361 
362 	ret = vfs_fsync_range(fd_dev->fd_file, start, end, 1);
363 	if (ret != 0)
364 		pr_err("FILEIO: vfs_fsync_range() failed: %d\n", ret);
365 
366 	if (immed)
367 		return 0;
368 
369 	if (ret)
370 		target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
371 	else
372 		target_complete_cmd(cmd, SAM_STAT_GOOD);
373 
374 	return 0;
375 }
376 
377 static unsigned char *
378 fd_setup_write_same_buf(struct se_cmd *cmd, struct scatterlist *sg,
379 		    unsigned int len)
380 {
381 	struct se_device *se_dev = cmd->se_dev;
382 	unsigned int block_size = se_dev->dev_attrib.block_size;
383 	unsigned int i = 0, end;
384 	unsigned char *buf, *p, *kmap_buf;
385 
386 	buf = kzalloc(min_t(unsigned int, len, PAGE_SIZE), GFP_KERNEL);
387 	if (!buf) {
388 		pr_err("Unable to allocate fd_execute_write_same buf\n");
389 		return NULL;
390 	}
391 
392 	kmap_buf = kmap(sg_page(sg)) + sg->offset;
393 	if (!kmap_buf) {
394 		pr_err("kmap() failed in fd_setup_write_same\n");
395 		kfree(buf);
396 		return NULL;
397 	}
398 	/*
399 	 * Fill local *buf to contain multiple WRITE_SAME blocks up to
400 	 * min(len, PAGE_SIZE)
401 	 */
402 	p = buf;
403 	end = min_t(unsigned int, len, PAGE_SIZE);
404 
405 	while (i < end) {
406 		memcpy(p, kmap_buf, block_size);
407 
408 		i += block_size;
409 		p += block_size;
410 	}
411 	kunmap(sg_page(sg));
412 
413 	return buf;
414 }
415 
416 static sense_reason_t
417 fd_execute_write_same(struct se_cmd *cmd)
418 {
419 	struct se_device *se_dev = cmd->se_dev;
420 	struct fd_dev *fd_dev = FD_DEV(se_dev);
421 	struct file *f = fd_dev->fd_file;
422 	struct scatterlist *sg;
423 	struct iovec *iov;
424 	mm_segment_t old_fs;
425 	sector_t nolb = sbc_get_write_same_sectors(cmd);
426 	loff_t pos = cmd->t_task_lba * se_dev->dev_attrib.block_size;
427 	unsigned int len, len_tmp, iov_num;
428 	int i, rc;
429 	unsigned char *buf;
430 
431 	if (!nolb) {
432 		target_complete_cmd(cmd, SAM_STAT_GOOD);
433 		return 0;
434 	}
435 	sg = &cmd->t_data_sg[0];
436 
437 	if (cmd->t_data_nents > 1 ||
438 	    sg->length != cmd->se_dev->dev_attrib.block_size) {
439 		pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
440 			" block_size: %u\n", cmd->t_data_nents, sg->length,
441 			cmd->se_dev->dev_attrib.block_size);
442 		return TCM_INVALID_CDB_FIELD;
443 	}
444 
445 	len = len_tmp = nolb * se_dev->dev_attrib.block_size;
446 	iov_num = DIV_ROUND_UP(len, PAGE_SIZE);
447 
448 	buf = fd_setup_write_same_buf(cmd, sg, len);
449 	if (!buf)
450 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
451 
452 	iov = vzalloc(sizeof(struct iovec) * iov_num);
453 	if (!iov) {
454 		pr_err("Unable to allocate fd_execute_write_same iovecs\n");
455 		kfree(buf);
456 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
457 	}
458 	/*
459 	 * Map the single fabric received scatterlist block now populated
460 	 * in *buf into each iovec for I/O submission.
461 	 */
462 	for (i = 0; i < iov_num; i++) {
463 		iov[i].iov_base = buf;
464 		iov[i].iov_len = min_t(unsigned int, len_tmp, PAGE_SIZE);
465 		len_tmp -= iov[i].iov_len;
466 	}
467 
468 	old_fs = get_fs();
469 	set_fs(get_ds());
470 	rc = vfs_writev(f, &iov[0], iov_num, &pos);
471 	set_fs(old_fs);
472 
473 	vfree(iov);
474 	kfree(buf);
475 
476 	if (rc < 0 || rc != len) {
477 		pr_err("vfs_writev() returned %d for write same\n", rc);
478 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
479 	}
480 
481 	target_complete_cmd(cmd, SAM_STAT_GOOD);
482 	return 0;
483 }
484 
485 static sense_reason_t
486 fd_do_unmap(struct se_cmd *cmd, void *priv, sector_t lba, sector_t nolb)
487 {
488 	struct file *file = priv;
489 	struct inode *inode = file->f_mapping->host;
490 	int ret;
491 
492 	if (S_ISBLK(inode->i_mode)) {
493 		/* The backend is block device, use discard */
494 		struct block_device *bdev = inode->i_bdev;
495 
496 		ret = blkdev_issue_discard(bdev, lba,
497 				nolb, GFP_KERNEL, 0);
498 		if (ret < 0) {
499 			pr_warn("FILEIO: blkdev_issue_discard() failed: %d\n",
500 				ret);
501 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
502 		}
503 	} else {
504 		/* The backend is normal file, use fallocate */
505 		struct se_device *se_dev = cmd->se_dev;
506 		loff_t pos = lba * se_dev->dev_attrib.block_size;
507 		unsigned int len = nolb * se_dev->dev_attrib.block_size;
508 		int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
509 
510 		if (!file->f_op->fallocate)
511 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
512 
513 		ret = file->f_op->fallocate(file, mode, pos, len);
514 		if (ret < 0) {
515 			pr_warn("FILEIO: fallocate() failed: %d\n", ret);
516 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
517 		}
518 	}
519 
520 	return 0;
521 }
522 
523 static sense_reason_t
524 fd_execute_write_same_unmap(struct se_cmd *cmd)
525 {
526 	struct se_device *se_dev = cmd->se_dev;
527 	struct fd_dev *fd_dev = FD_DEV(se_dev);
528 	struct file *file = fd_dev->fd_file;
529 	sector_t lba = cmd->t_task_lba;
530 	sector_t nolb = sbc_get_write_same_sectors(cmd);
531 	int ret;
532 
533 	if (!nolb) {
534 		target_complete_cmd(cmd, SAM_STAT_GOOD);
535 		return 0;
536 	}
537 
538 	ret = fd_do_unmap(cmd, file, lba, nolb);
539 	if (ret)
540 		return ret;
541 
542 	target_complete_cmd(cmd, GOOD);
543 	return 0;
544 }
545 
546 static sense_reason_t
547 fd_execute_unmap(struct se_cmd *cmd)
548 {
549 	struct file *file = FD_DEV(cmd->se_dev)->fd_file;
550 
551 	return sbc_execute_unmap(cmd, fd_do_unmap, file);
552 }
553 
554 static sense_reason_t
555 fd_execute_rw(struct se_cmd *cmd)
556 {
557 	struct scatterlist *sgl = cmd->t_data_sg;
558 	u32 sgl_nents = cmd->t_data_nents;
559 	enum dma_data_direction data_direction = cmd->data_direction;
560 	struct se_device *dev = cmd->se_dev;
561 	int ret = 0;
562 
563 	/*
564 	 * Call vectorized fileio functions to map struct scatterlist
565 	 * physical memory addresses to struct iovec virtual memory.
566 	 */
567 	if (data_direction == DMA_FROM_DEVICE) {
568 		ret = fd_do_rw(cmd, sgl, sgl_nents, 0);
569 	} else {
570 		ret = fd_do_rw(cmd, sgl, sgl_nents, 1);
571 		/*
572 		 * Perform implict vfs_fsync_range() for fd_do_writev() ops
573 		 * for SCSI WRITEs with Forced Unit Access (FUA) set.
574 		 * Allow this to happen independent of WCE=0 setting.
575 		 */
576 		if (ret > 0 &&
577 		    dev->dev_attrib.emulate_fua_write > 0 &&
578 		    (cmd->se_cmd_flags & SCF_FUA)) {
579 			struct fd_dev *fd_dev = FD_DEV(dev);
580 			loff_t start = cmd->t_task_lba *
581 				dev->dev_attrib.block_size;
582 			loff_t end = start + cmd->data_length;
583 
584 			vfs_fsync_range(fd_dev->fd_file, start, end, 1);
585 		}
586 	}
587 
588 	if (ret < 0)
589 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
590 
591 	if (ret)
592 		target_complete_cmd(cmd, SAM_STAT_GOOD);
593 	return 0;
594 }
595 
596 enum {
597 	Opt_fd_dev_name, Opt_fd_dev_size, Opt_fd_buffered_io, Opt_err
598 };
599 
600 static match_table_t tokens = {
601 	{Opt_fd_dev_name, "fd_dev_name=%s"},
602 	{Opt_fd_dev_size, "fd_dev_size=%s"},
603 	{Opt_fd_buffered_io, "fd_buffered_io=%d"},
604 	{Opt_err, NULL}
605 };
606 
607 static ssize_t fd_set_configfs_dev_params(struct se_device *dev,
608 		const char *page, ssize_t count)
609 {
610 	struct fd_dev *fd_dev = FD_DEV(dev);
611 	char *orig, *ptr, *arg_p, *opts;
612 	substring_t args[MAX_OPT_ARGS];
613 	int ret = 0, arg, token;
614 
615 	opts = kstrdup(page, GFP_KERNEL);
616 	if (!opts)
617 		return -ENOMEM;
618 
619 	orig = opts;
620 
621 	while ((ptr = strsep(&opts, ",\n")) != NULL) {
622 		if (!*ptr)
623 			continue;
624 
625 		token = match_token(ptr, tokens, args);
626 		switch (token) {
627 		case Opt_fd_dev_name:
628 			if (match_strlcpy(fd_dev->fd_dev_name, &args[0],
629 				FD_MAX_DEV_NAME) == 0) {
630 				ret = -EINVAL;
631 				break;
632 			}
633 			pr_debug("FILEIO: Referencing Path: %s\n",
634 					fd_dev->fd_dev_name);
635 			fd_dev->fbd_flags |= FBDF_HAS_PATH;
636 			break;
637 		case Opt_fd_dev_size:
638 			arg_p = match_strdup(&args[0]);
639 			if (!arg_p) {
640 				ret = -ENOMEM;
641 				break;
642 			}
643 			ret = strict_strtoull(arg_p, 0, &fd_dev->fd_dev_size);
644 			kfree(arg_p);
645 			if (ret < 0) {
646 				pr_err("strict_strtoull() failed for"
647 						" fd_dev_size=\n");
648 				goto out;
649 			}
650 			pr_debug("FILEIO: Referencing Size: %llu"
651 					" bytes\n", fd_dev->fd_dev_size);
652 			fd_dev->fbd_flags |= FBDF_HAS_SIZE;
653 			break;
654 		case Opt_fd_buffered_io:
655 			match_int(args, &arg);
656 			if (arg != 1) {
657 				pr_err("bogus fd_buffered_io=%d value\n", arg);
658 				ret = -EINVAL;
659 				goto out;
660 			}
661 
662 			pr_debug("FILEIO: Using buffered I/O"
663 				" operations for struct fd_dev\n");
664 
665 			fd_dev->fbd_flags |= FDBD_HAS_BUFFERED_IO_WCE;
666 			break;
667 		default:
668 			break;
669 		}
670 	}
671 
672 out:
673 	kfree(orig);
674 	return (!ret) ? count : ret;
675 }
676 
677 static ssize_t fd_show_configfs_dev_params(struct se_device *dev, char *b)
678 {
679 	struct fd_dev *fd_dev = FD_DEV(dev);
680 	ssize_t bl = 0;
681 
682 	bl = sprintf(b + bl, "TCM FILEIO ID: %u", fd_dev->fd_dev_id);
683 	bl += sprintf(b + bl, "        File: %s  Size: %llu  Mode: %s\n",
684 		fd_dev->fd_dev_name, fd_dev->fd_dev_size,
685 		(fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) ?
686 		"Buffered-WCE" : "O_DSYNC");
687 	return bl;
688 }
689 
690 static sector_t fd_get_blocks(struct se_device *dev)
691 {
692 	struct fd_dev *fd_dev = FD_DEV(dev);
693 	struct file *f = fd_dev->fd_file;
694 	struct inode *i = f->f_mapping->host;
695 	unsigned long long dev_size;
696 	/*
697 	 * When using a file that references an underlying struct block_device,
698 	 * ensure dev_size is always based on the current inode size in order
699 	 * to handle underlying block_device resize operations.
700 	 */
701 	if (S_ISBLK(i->i_mode))
702 		dev_size = (i_size_read(i) - fd_dev->fd_block_size);
703 	else
704 		dev_size = fd_dev->fd_dev_size;
705 
706 	return div_u64(dev_size, dev->dev_attrib.block_size);
707 }
708 
709 static struct sbc_ops fd_sbc_ops = {
710 	.execute_rw		= fd_execute_rw,
711 	.execute_sync_cache	= fd_execute_sync_cache,
712 	.execute_write_same	= fd_execute_write_same,
713 	.execute_write_same_unmap = fd_execute_write_same_unmap,
714 	.execute_unmap		= fd_execute_unmap,
715 };
716 
717 static sense_reason_t
718 fd_parse_cdb(struct se_cmd *cmd)
719 {
720 	return sbc_parse_cdb(cmd, &fd_sbc_ops);
721 }
722 
723 static struct se_subsystem_api fileio_template = {
724 	.name			= "fileio",
725 	.inquiry_prod		= "FILEIO",
726 	.inquiry_rev		= FD_VERSION,
727 	.owner			= THIS_MODULE,
728 	.transport_type		= TRANSPORT_PLUGIN_VHBA_PDEV,
729 	.attach_hba		= fd_attach_hba,
730 	.detach_hba		= fd_detach_hba,
731 	.alloc_device		= fd_alloc_device,
732 	.configure_device	= fd_configure_device,
733 	.free_device		= fd_free_device,
734 	.parse_cdb		= fd_parse_cdb,
735 	.set_configfs_dev_params = fd_set_configfs_dev_params,
736 	.show_configfs_dev_params = fd_show_configfs_dev_params,
737 	.get_device_type	= sbc_get_device_type,
738 	.get_blocks		= fd_get_blocks,
739 };
740 
741 static int __init fileio_module_init(void)
742 {
743 	return transport_subsystem_register(&fileio_template);
744 }
745 
746 static void __exit fileio_module_exit(void)
747 {
748 	transport_subsystem_release(&fileio_template);
749 }
750 
751 MODULE_DESCRIPTION("TCM FILEIO subsystem plugin");
752 MODULE_AUTHOR("nab@Linux-iSCSI.org");
753 MODULE_LICENSE("GPL");
754 
755 module_init(fileio_module_init);
756 module_exit(fileio_module_exit);
757