summaryrefslogtreecommitdiffstats
path: root/drivers/target/target_core_file.c
blob: 0e34cda3271e9bb3291b06a934c1ef7136488811 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
/*******************************************************************************
 * Filename:  target_core_file.c
 *
 * This file contains the Storage Engine <-> FILEIO transport specific functions
 *
 * (c) Copyright 2005-2013 Datera, Inc.
 *
 * Nicholas A. Bellinger <nab@kernel.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 ******************************************************************************/

#include <linux/string.h>
#include <linux/parser.h>
#include <linux/timer.h>
#include <linux/blkdev.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/module.h>
#include <linux/falloc.h>
#include <scsi/scsi.h>
#include <scsi/scsi_host.h>
#include <asm/unaligned.h>

#include <target/target_core_base.h>
#include <target/target_core_backend.h>

#include "target_core_file.h"

static inline struct fd_dev *FD_DEV(struct se_device *dev)
{
	return container_of(dev, struct fd_dev, dev);
}

/*	fd_attach_hba(): (Part of se_subsystem_api_t template)
 *
 *
 */
static int fd_attach_hba(struct se_hba *hba, u32 host_id)
{
	struct fd_host *fd_host;

	fd_host = kzalloc(sizeof(struct fd_host), GFP_KERNEL);
	if (!fd_host) {
		pr_err("Unable to allocate memory for struct fd_host\n");
		return -ENOMEM;
	}

	fd_host->fd_host_id = host_id;

	hba->hba_ptr = fd_host;

	pr_debug("CORE_HBA[%d] - TCM FILEIO HBA Driver %s on Generic"
		" Target Core Stack %s\n", hba->hba_id, FD_VERSION,
		TARGET_CORE_MOD_VERSION);
	pr_debug("CORE_HBA[%d] - Attached FILEIO HBA: %u to Generic"
		" MaxSectors: %u\n",
		hba->hba_id, fd_host->fd_host_id, FD_MAX_SECTORS);

	return 0;
}

static void fd_detach_hba(struct se_hba *hba)
{
	struct fd_host *fd_host = hba->hba_ptr;

	pr_debug("CORE_HBA[%d] - Detached FILEIO HBA: %u from Generic"
		" Target Core\n", hba->hba_id, fd_host->fd_host_id);

	kfree(fd_host);
	hba->hba_ptr = NULL;
}

static struct se_device *fd_alloc_device(struct se_hba *hba, const char *name)
{
	struct fd_dev *fd_dev;
	struct fd_host *fd_host = hba->hba_ptr;

	fd_dev = kzalloc(sizeof(struct fd_dev), GFP_KERNEL);
	if (!fd_dev) {
		pr_err("Unable to allocate memory for struct fd_dev\n");
		return NULL;
	}

	fd_dev->fd_host = fd_host;

	pr_debug("FILEIO: Allocated fd_dev for %p\n", name);

	return &fd_dev->dev;
}

static int fd_configure_device(struct se_device *dev)
{
	struct fd_dev *fd_dev = FD_DEV(dev);
	struct fd_host *fd_host = dev->se_hba->hba_ptr;
	struct file *file;
	struct inode *inode = NULL;
	int flags, ret = -EINVAL;

	if (!(fd_dev->fbd_flags & FBDF_HAS_PATH)) {
		pr_err("Missing fd_dev_name=\n");
		return -EINVAL;
	}

	/*
	 * Use O_DSYNC by default instead of O_SYNC to forgo syncing
	 * of pure timestamp updates.
	 */
	flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;

	/*
	 * Optionally allow fd_buffered_io=1 to be enabled for people
	 * who want use the fs buffer cache as an WriteCache mechanism.
	 *
	 * This means that in event of a hard failure, there is a risk
	 * of silent data-loss if the SCSI client has *not* performed a
	 * forced unit access (FUA) write, or issued SYNCHRONIZE_CACHE
	 * to write-out the entire device cache.
	 */
	if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
		pr_debug("FILEIO: Disabling O_DSYNC, using buffered FILEIO\n");
		flags &= ~O_DSYNC;
	}

	file = filp_open(fd_dev->fd_dev_name, flags, 0600);
	if (IS_ERR(file)) {
		pr_err("filp_open(%s) failed\n", fd_dev->fd_dev_name);
		ret = PTR_ERR(file);
		goto fail;
	}
	fd_dev->fd_file = file;
	/*
	 * If using a block backend with this struct file, we extract
	 * fd_dev->fd_[block,dev]_size from struct block_device.
	 *
	 * Otherwise, we use the passed fd_size= from configfs
	 */
	inode = file->f_mapping->host;
	if (S_ISBLK(inode->i_mode)) {
		struct request_queue *q = bdev_get_queue(inode->i_bdev);
		unsigned long long dev_size;

		fd_dev->fd_block_size = bdev_logical_block_size(inode->i_bdev);
		/*
		 * Determine the number of bytes from i_size_read() minus
		 * one (1) logical sector from underlying struct block_device
		 */
		dev_size = (i_size_read(file->f_mapping->host) -
				       fd_dev->fd_block_size);

		pr_debug("FILEIO: Using size: %llu bytes from struct"
			" block_device blocks: %llu logical_block_size: %d\n",
			dev_size, div_u64(dev_size, fd_dev->fd_block_size),
			fd_dev->fd_block_size);
		/*
		 * Check if the underlying struct block_device request_queue supports
		 * the QUEUE_FLAG_DISCARD bit for UNMAP/WRITE_SAME in SCSI + TRIM
		 * in ATA and we need to set TPE=1
		 */
		if (blk_queue_discard(q)) {
			dev->dev_attrib.max_unmap_lba_count =
				q->limits.max_discard_sectors;
			/*
			 * Currently hardcoded to 1 in Linux/SCSI code..
			 */
			dev->dev_attrib.max_unmap_block_desc_count = 1;
			dev->dev_attrib.unmap_granularity =
				q->limits.discard_granularity >> 9;
			dev->dev_attrib.unmap_granularity_alignment =
				q->limits.discard_alignment;
			pr_debug("IFILE: BLOCK Discard support available,"
					" disabled by default\n");
		}
		/*
		 * Enable write same emulation for IBLOCK and use 0xFFFF as
		 * the smaller WRITE_SAME(10) only has a two-byte block count.
		 */
		dev->dev_attrib.max_write_same_len = 0xFFFF;

		if (blk_queue_nonrot(q))
			dev->dev_attrib.is_nonrot = 1;
	} else {
		if (!(fd_dev->fbd_flags & FBDF_HAS_SIZE)) {
			pr_err("FILEIO: Missing fd_dev_size="
				" parameter, and no backing struct"
				" block_device\n");
			goto fail;
		}

		fd_dev->fd_block_size = FD_BLOCKSIZE;
		/*
		 * Limit UNMAP emulation to 8k Number of LBAs (NoLB)
		 */
		dev->dev_attrib.max_unmap_lba_count = 0x2000;
		/*
		 * Currently hardcoded to 1 in Linux/SCSI code..
		 */
		dev->dev_attrib.max_unmap_block_desc_count = 1;
		dev->dev_attrib.unmap_granularity = 1;
		dev->dev_attrib.unmap_granularity_alignment = 0;

		/*
		 * Limit WRITE_SAME w/ UNMAP=0 emulation to 8k Number of LBAs (NoLB)
		 * based upon struct iovec limit for vfs_writev()
		 */
		dev->dev_attrib.max_write_same_len = 0x1000;
	}

	dev->dev_attrib.hw_block_size = fd_dev->fd_block_size;
	dev->dev_attrib.hw_max_sectors = FD_MAX_SECTORS;
	dev->dev_attrib.hw_queue_depth = FD_MAX_DEVICE_QUEUE_DEPTH;

	if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
		pr_debug("FILEIO: Forcing setting of emulate_write_cache=1"
			" with FDBD_HAS_BUFFERED_IO_WCE\n");
		dev->dev_attrib.emulate_write_cache = 1;
	}

	fd_dev->fd_dev_id = fd_host->fd_host_dev_id_count++;
	fd_dev->fd_queue_depth = dev->queue_depth;

	pr_debug("CORE_FILE[%u] - Added TCM FILEIO Device ID: %u at %s,"
		" %llu total bytes\n", fd_host->fd_host_id, fd_dev->fd_dev_id,
			fd_dev->fd_dev_name, fd_dev->fd_dev_size);

	return 0;
fail:
	if (fd_dev->fd_file) {
		filp_close(fd_dev->fd_file, NULL);
		fd_dev->fd_file = NULL;
	}
	return ret;
}

static void fd_free_device(struct se_device *dev)
{
	struct fd_dev *fd_dev = FD_DEV(dev);

	if (fd_dev->fd_file) {
		filp_close(fd_dev->fd_file, NULL);
		fd_dev->fd_file = NULL;
	}

	kfree(fd_dev);
}

static int fd_do_rw(struct se_cmd *cmd, struct scatterlist *sgl,
		u32 sgl_nents, int is_write)
{
	struct se_device *se_dev = cmd->se_dev;
	struct fd_dev *dev = FD_DEV(se_dev);
	struct file *fd = dev->fd_file;
	struct scatterlist *sg;
	struct iovec *iov;
	mm_segment_t old_fs;
	loff_t pos = (cmd->t_task_lba * se_dev->dev_attrib.block_size);
	int ret = 0, i;

	iov = kzalloc(sizeof(struct iovec) * sgl_nents, GFP_KERNEL);
	if (!iov) {
		pr_err("Unable to allocate fd_do_readv iov[]\n");
		return -ENOMEM;
	}

	for_each_sg(sgl, sg, sgl_nents, i) {
		iov[i].iov_len = sg->length;
		iov[i].iov_base = kmap(sg_page(sg)) + sg->offset;
	}

	old_fs = get_fs();
	set_fs(get_ds());

	if (is_write)
		ret = vfs_writev(fd, &iov[0], sgl_nents, &pos);
	else
		ret = vfs_readv(fd, &iov[0], sgl_nents, &pos);

	set_fs(old_fs);

	for_each_sg(sgl, sg, sgl_nents, i)
		kunmap(sg_page(sg));

	kfree(iov);

	if (is_write) {
		if (ret < 0 || ret != cmd->data_length) {
			pr_err("%s() write returned %d\n", __func__, ret);
			return (ret < 0 ? ret : -EINVAL);
		}
	} else {
		/*
		 * Return zeros and GOOD status even if the READ did not return
		 * the expected virt_size for struct file w/o a backing struct
		 * block_device.
		 */
		if (S_ISBLK(file_inode(fd)->i_mode)) {
			if (ret < 0 || ret != cmd->data_length) {
				pr_err("%s() returned %d, expecting %u for "
						"S_ISBLK\n", __func__, ret,
						cmd->data_length);
				return (ret < 0 ? ret : -EINVAL);
			}
		} else {
			if (ret < 0) {
				pr_err("%s() returned %d for non S_ISBLK\n",
						__func__, ret);
				return ret;
			}
		}
	}
	return 1;
}

static sense_reason_t
fd_execute_sync_cache(struct se_cmd *cmd)
{
	struct se_device *dev = cmd->se_dev;
	struct fd_dev *fd_dev = FD_DEV(dev);
	int immed = (cmd->t_task_cdb[1] & 0x2);
	loff_t start, end;
	int ret;

	/*
	 * If the Immediate bit is set, queue up the GOOD response
	 * for this SYNCHRONIZE_CACHE op
	 */
	if (immed)
		target_complete_cmd(cmd, SAM_STAT_GOOD);

	/*
	 * Determine if we will be flushing the entire device.
	 */
	if (cmd->t_task_lba == 0 && cmd->data_length == 0) {
		start = 0;
		end = LLONG_MAX;
	} else {
		start = cmd->t_task_lba * dev->dev_attrib.block_size;
		if (cmd->data_length)
			end = start + cmd->data_length;
		else
			end = LLONG_MAX;
	}

	ret = vfs_fsync_range(fd_dev->fd_file, start, end, 1);
	if (ret != 0)
		pr_err("FILEIO: vfs_fsync_range() failed: %d\n", ret);

	if (immed)
		return 0;

	if (ret)
		target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
	else
		target_complete_cmd(cmd, SAM_STAT_GOOD);

	return 0;
}

static unsigned char *
fd_setup_write_same_buf(struct se_cmd *cmd, struct scatterlist *sg,
		    unsigned int len)
{
	struct se_device *se_dev = cmd->se_dev;
	unsigned int block_size = se_dev->dev_attrib.block_size;
	unsigned int i = 0, end;
	unsigned char *buf, *p, *kmap_buf;

	buf = kzalloc(min_t(unsigned int, len, PAGE_SIZE), GFP_KERNEL);
	if (!buf) {
		pr_err("Unable to allocate fd_execute_write_same buf\n");
		return NULL;
	}

	kmap_buf = kmap(sg_page(sg)) + sg->offset;
	if (!kmap_buf) {
		pr_err("kmap() failed in fd_setup_write_same\n");
		kfree(buf);
		return NULL;
	}
	/*
	 * Fill local *buf to contain multiple WRITE_SAME blocks up to
	 * min(len, PAGE_SIZE)
	 */
	p = buf;
	end = min_t(unsigned int, len, PAGE_SIZE);

	while (i < end) {
		memcpy(p, kmap_buf, block_size);

		i += block_size;
		p += block_size;
	}
	kunmap(sg_page(sg));

	return buf;
}

static sense_reason_t
fd_execute_write_same(struct se_cmd *cmd)
{
	struct se_device *se_dev = cmd->se_dev;
	struct fd_dev *fd_dev = FD_DEV(se_dev);
	struct file *f = fd_dev->fd_file;
	struct scatterlist *sg;
	struct iovec *iov;
	mm_segment_t old_fs;
	sector_t nolb = sbc_get_write_same_sectors(cmd);
	loff_t pos = cmd->t_task_lba * se_dev->dev_attrib.block_size;
	unsigned int len, len_tmp, iov_num;
	int i, rc;
	unsigned char *buf;

	if (!nolb) {
		target_complete_cmd(cmd, SAM_STAT_GOOD);
		return 0;
	}
	sg = &cmd->t_data_sg[0];

	if (cmd->t_data_nents > 1 ||
	    sg->length != cmd->se_dev->dev_attrib.block_size) {
		pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
			" block_size: %u\n", cmd->t_data_nents, sg->length,
			cmd->se_dev->dev_attrib.block_size);
		return TCM_INVALID_CDB_FIELD;
	}

	len = len_tmp = nolb * se_dev->dev_attrib.block_size;
	iov_num = DIV_ROUND_UP(len, PAGE_SIZE);

	buf = fd_setup_write_same_buf(cmd, sg, len);
	if (!buf)
		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;

	iov = vzalloc(sizeof(struct iovec) * iov_num);
	if (!iov) {
		pr_err("Unable to allocate fd_execute_write_same iovecs\n");
		kfree(buf);
		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
	}
	/*
	 * Map the single fabric received scatterlist block now populated
	 * in *buf into each iovec for I/O submission.
	 */
	for (i = 0; i < iov_num; i++) {
		iov[i].iov_base = buf;
		iov[i].iov_len = min_t(unsigned int, len_tmp, PAGE_SIZE);
		len_tmp -= iov[i].iov_len;
	}

	old_fs = get_fs();
	set_fs(get_ds());
	rc = vfs_writev(f, &iov[0], iov_num, &pos);
	set_fs(old_fs);

	vfree(iov);
	kfree(buf);

	if (rc < 0 || rc != len) {
		pr_err("vfs_writev() returned %d for write same\n", rc);
		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
	}

	target_complete_cmd(cmd, SAM_STAT_GOOD);
	return 0;
}

static sense_reason_t
fd_do_unmap(struct se_cmd *cmd, void *priv, sector_t lba, sector_t nolb)
{
	struct file *file = priv;
	struct inode *inode = file->f_mapping->host;
	int ret;

	if (S_ISBLK(inode->i_mode)) {
		/* The backend is block device, use discard */
		struct block_device *bdev = inode->i_bdev;

		ret = blkdev_issue_discard(bdev, lba,
				nolb, GFP_KERNEL, 0);
		if (ret < 0) {
			pr_warn("FILEIO: blkdev_issue_discard() failed: %d\n",
				ret);
			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
		}
	} else {
		/* The backend is normal file, use fallocate */
		struct se_device *se_dev = cmd->se_dev;
		loff_t pos = lba * se_dev->dev_attrib.block_size;
		unsigned int len = nolb * se_dev->dev_attrib.block_size;
		int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;

		if (!file->f_op->fallocate)
			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;

		ret = file->f_op->fallocate(file, mode, pos, len);
		if (ret < 0) {
			pr_warn("FILEIO: fallocate() failed: %d\n", ret);
			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
		}
	}

	return 0;
}

static sense_reason_t
fd_execute_write_same_unmap(struct se_cmd *cmd)
{
	struct se_device *se_dev = cmd->se_dev;
	struct fd_dev *fd_dev = FD_DEV(se_dev);
	struct file *file = fd_dev->fd_file;
	sector_t lba = cmd->t_task_lba;
	sector_t nolb = sbc_get_write_same_sectors(cmd);
	int ret;

	if (!nolb) {
		target_complete_cmd(cmd, SAM_STAT_GOOD);
		return 0;
	}

	ret = fd_do_unmap(cmd, file, lba, nolb);
	if (ret)
		return ret;

	target_complete_cmd(cmd, GOOD);
	return 0;
}

static sense_reason_t
fd_execute_unmap(struct se_cmd *cmd)
{
	struct file *file = FD_DEV(cmd->se_dev)->fd_file;

	return sbc_execute_unmap(cmd, fd_do_unmap, file);
}

static sense_reason_t
fd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
	      enum dma_data_direction data_direction)
{
	struct se_device *dev = cmd->se_dev;
	int ret = 0;

	/*
	 * Call vectorized fileio functions to map struct scatterlist
	 * physical memory addresses to struct iovec virtual memory.
	 */
	if (data_direction == DMA_FROM_DEVICE) {
		ret = fd_do_rw(cmd, sgl, sgl_nents, 0);
	} else {
		ret = fd_do_rw(cmd, sgl, sgl_nents, 1);
		/*
		 * Perform implicit vfs_fsync_range() for fd_do_writev() ops
		 * for SCSI WRITEs with Forced Unit Access (FUA) set.
		 * Allow this to happen independent of WCE=0 setting.
		 */
		if (ret > 0 &&
		    dev->dev_attrib.emulate_fua_write > 0 &&
		    (cmd->se_cmd_flags & SCF_FUA)) {
			struct fd_dev *fd_dev = FD_DEV(dev);
			loff_t start = cmd->t_task_lba *
				dev->dev_attrib.block_size;
			loff_t end = start + cmd->data_length;

			vfs_fsync_range(fd_dev->fd_file, start, end, 1);
		}
	}

	if (ret < 0)
		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;

	if (ret)
		target_complete_cmd(cmd, SAM_STAT_GOOD);
	return 0;
}

enum {
	Opt_fd_dev_name, Opt_fd_dev_size, Opt_fd_buffered_io, Opt_err
};

static match_table_t tokens = {
	{Opt_fd_dev_name, "fd_dev_name=%s"},
	{Opt_fd_dev_size, "fd_dev_size=%s"},
	{Opt_fd_buffered_io, "fd_buffered_io=%d"},
	{Opt_err, NULL}
};

static ssize_t fd_set_configfs_dev_params(struct se_device *dev,
		const char *page, ssize_t count)
{
	struct fd_dev *fd_dev = FD_DEV(dev);
	char *orig, *ptr, *arg_p, *opts;
	substring_t args[MAX_OPT_ARGS];
	int ret = 0, arg, token;

	opts = kstrdup(page, GFP_KERNEL);
	if (!opts)
		return -ENOMEM;

	orig = opts;

	while ((ptr = strsep(&opts, ",\n")) != NULL) {
		if (!*ptr)
			continue;

		token = match_token(ptr, tokens, args);
		switch (token) {
		case Opt_fd_dev_name:
			if (match_strlcpy(fd_dev->fd_dev_name, &args[0],
				FD_MAX_DEV_NAME) == 0) {
				ret = -EINVAL;
				break;
			}
			pr_debug("FILEIO: Referencing Path: %s\n",
					fd_dev->fd_dev_name);
			fd_dev->fbd_flags |= FBDF_HAS_PATH;
			break;
		case Opt_fd_dev_size:
			arg_p = match_strdup(&args[0]);
			if (!arg_p) {
				ret = -ENOMEM;
				break;
			}
			ret = kstrtoull(arg_p, 0, &fd_dev->fd_dev_size);
			kfree(arg_p);
			if (ret < 0) {
				pr_err("kstrtoull() failed for"
						" fd_dev_size=\n");
				goto out;
			}
			pr_debug("FILEIO: Referencing Size: %llu"
					" bytes\n", fd_dev->fd_dev_size);
			fd_dev->fbd_flags |= FBDF_HAS_SIZE;
			break;
		case Opt_fd_buffered_io:
			match_int(args, &arg);
			if (arg != 1) {
				pr_err("bogus fd_buffered_io=%d value\n", arg);
				ret = -EINVAL;
				goto out;
			}

			pr_debug("FILEIO: Using buffered I/O"
				" operations for struct fd_dev\n");

			fd_dev->fbd_flags |= FDBD_HAS_BUFFERED_IO_WCE;
			break;
		default:
			break;
		}
	}

out:
	kfree(orig);
	return (!ret) ? count : ret;
}

static ssize_t fd_show_configfs_dev_params(struct se_device *dev, char *b)
{
	struct fd_dev *fd_dev = FD_DEV(dev);
	ssize_t bl = 0;

	bl = sprintf(b + bl, "TCM FILEIO ID: %u", fd_dev->fd_dev_id);
	bl += sprintf(b + bl, "        File: %s  Size: %llu  Mode: %s\n",
		fd_dev->fd_dev_name, fd_dev->fd_dev_size,
		(fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) ?
		"Buffered-WCE" : "O_DSYNC");
	return bl;
}

static sector_t fd_get_blocks(struct se_device *dev)
{
	struct fd_dev *fd_dev = FD_DEV(dev);
	struct file *f = fd_dev->fd_file;
	struct inode *i = f->f_mapping->host;
	unsigned long long dev_size;
	/*
	 * When using a file that references an underlying struct block_device,
	 * ensure dev_size is always based on the current inode size in order
	 * to handle underlying block_device resize operations.
	 */
	if (S_ISBLK(i->i_mode))
		dev_size = i_size_read(i);
	else
		dev_size = fd_dev->fd_dev_size;

	return div_u64(dev_size - dev->dev_attrib.block_size,
		       dev->dev_attrib.block_size);
}

static struct sbc_ops fd_sbc_ops = {
	.execute_rw		= fd_execute_rw,
	.execute_sync_cache	= fd_execute_sync_cache,
	.execute_write_same	= fd_execute_write_same,
	.execute_write_same_unmap = fd_execute_write_same_unmap,
	.execute_unmap		= fd_execute_unmap,
};

static sense_reason_t
fd_parse_cdb(struct se_cmd *cmd)
{
	return sbc_parse_cdb(cmd, &fd_sbc_ops);
}

static struct se_subsystem_api fileio_template = {
	.name			= "fileio",
	.inquiry_prod		= "FILEIO",
	.inquiry_rev		= FD_VERSION,
	.owner			= THIS_MODULE,
	.transport_type		= TRANSPORT_PLUGIN_VHBA_PDEV,
	.attach_hba		= fd_attach_hba,
	.detach_hba		= fd_detach_hba,
	.alloc_device		= fd_alloc_device,
	.configure_device	= fd_configure_device,
	.free_device		= fd_free_device,
	.parse_cdb		= fd_parse_cdb,
	.set_configfs_dev_params = fd_set_configfs_dev_params,
	.show_configfs_dev_params = fd_show_configfs_dev_params,
	.get_device_type	= sbc_get_device_type,
	.get_blocks		= fd_get_blocks,
};

static int __init fileio_module_init(void)
{
	return transport_subsystem_register(&fileio_template);
}

static void __exit fileio_module_exit(void)
{
	transport_subsystem_release(&fileio_template);
}

MODULE_DESCRIPTION("TCM FILEIO subsystem plugin");
MODULE_AUTHOR("nab@Linux-iSCSI.org");
MODULE_LICENSE("GPL");

module_init(fileio_module_init);
module_exit(fileio_module_exit);
OpenPOWER on IntegriCloud