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1/*******************************************************************************
2 * Filename:  target_core_file.c
3 *
4 * This file contains the Storage Engine <-> FILEIO transport specific functions
5 *
6 * (c) Copyright 2005-2013 Datera, Inc.
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
43static 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 */
52static 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\n",
70		hba->hba_id, fd_host->fd_host_id);
71
72	return 0;
73}
74
75static void fd_detach_hba(struct se_hba *hba)
76{
77	struct fd_host *fd_host = hba->hba_ptr;
78
79	pr_debug("CORE_HBA[%d] - Detached FILEIO HBA: %u from Generic"
80		" Target Core\n", hba->hba_id, fd_host->fd_host_id);
81
82	kfree(fd_host);
83	hba->hba_ptr = NULL;
84}
85
86static struct se_device *fd_alloc_device(struct se_hba *hba, const char *name)
87{
88	struct fd_dev *fd_dev;
89	struct fd_host *fd_host = hba->hba_ptr;
90
91	fd_dev = kzalloc(sizeof(struct fd_dev), GFP_KERNEL);
92	if (!fd_dev) {
93		pr_err("Unable to allocate memory for struct fd_dev\n");
94		return NULL;
95	}
96
97	fd_dev->fd_host = fd_host;
98
99	pr_debug("FILEIO: Allocated fd_dev for %p\n", name);
100
101	return &fd_dev->dev;
102}
103
104static int fd_configure_device(struct se_device *dev)
105{
106	struct fd_dev *fd_dev = FD_DEV(dev);
107	struct fd_host *fd_host = dev->se_hba->hba_ptr;
108	struct file *file;
109	struct inode *inode = NULL;
110	int flags, ret = -EINVAL;
111
112	if (!(fd_dev->fbd_flags & FBDF_HAS_PATH)) {
113		pr_err("Missing fd_dev_name=\n");
114		return -EINVAL;
115	}
116
117	/*
118	 * Use O_DSYNC by default instead of O_SYNC to forgo syncing
119	 * of pure timestamp updates.
120	 */
121	flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
122
123	/*
124	 * Optionally allow fd_buffered_io=1 to be enabled for people
125	 * who want use the fs buffer cache as an WriteCache mechanism.
126	 *
127	 * This means that in event of a hard failure, there is a risk
128	 * of silent data-loss if the SCSI client has *not* performed a
129	 * forced unit access (FUA) write, or issued SYNCHRONIZE_CACHE
130	 * to write-out the entire device cache.
131	 */
132	if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
133		pr_debug("FILEIO: Disabling O_DSYNC, using buffered FILEIO\n");
134		flags &= ~O_DSYNC;
135	}
136
137	file = filp_open(fd_dev->fd_dev_name, flags, 0600);
138	if (IS_ERR(file)) {
139		pr_err("filp_open(%s) failed\n", fd_dev->fd_dev_name);
140		ret = PTR_ERR(file);
141		goto fail;
142	}
143	fd_dev->fd_file = file;
144	/*
145	 * If using a block backend with this struct file, we extract
146	 * fd_dev->fd_[block,dev]_size from struct block_device.
147	 *
148	 * Otherwise, we use the passed fd_size= from configfs
149	 */
150	inode = file->f_mapping->host;
151	if (S_ISBLK(inode->i_mode)) {
152		struct request_queue *q = bdev_get_queue(inode->i_bdev);
153		unsigned long long dev_size;
154
155		fd_dev->fd_block_size = bdev_logical_block_size(inode->i_bdev);
156		/*
157		 * Determine the number of bytes from i_size_read() minus
158		 * one (1) logical sector from underlying struct block_device
159		 */
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		/*
168		 * Check if the underlying struct block_device request_queue supports
169		 * the QUEUE_FLAG_DISCARD bit for UNMAP/WRITE_SAME in SCSI + TRIM
170		 * in ATA and we need to set TPE=1
171		 */
172		if (blk_queue_discard(q)) {
173			dev->dev_attrib.max_unmap_lba_count =
174				q->limits.max_discard_sectors;
175			/*
176			 * Currently hardcoded to 1 in Linux/SCSI code..
177			 */
178			dev->dev_attrib.max_unmap_block_desc_count = 1;
179			dev->dev_attrib.unmap_granularity =
180				q->limits.discard_granularity >> 9;
181			dev->dev_attrib.unmap_granularity_alignment =
182				q->limits.discard_alignment;
183			pr_debug("IFILE: BLOCK Discard support available,"
184					" disabled by default\n");
185		}
186		/*
187		 * Enable write same emulation for IBLOCK and use 0xFFFF as
188		 * the smaller WRITE_SAME(10) only has a two-byte block count.
189		 */
190		dev->dev_attrib.max_write_same_len = 0xFFFF;
191
192		if (blk_queue_nonrot(q))
193			dev->dev_attrib.is_nonrot = 1;
194	} else {
195		if (!(fd_dev->fbd_flags & FBDF_HAS_SIZE)) {
196			pr_err("FILEIO: Missing fd_dev_size="
197				" parameter, and no backing struct"
198				" block_device\n");
199			goto fail;
200		}
201
202		fd_dev->fd_block_size = FD_BLOCKSIZE;
203		/*
204		 * Limit UNMAP emulation to 8k Number of LBAs (NoLB)
205		 */
206		dev->dev_attrib.max_unmap_lba_count = 0x2000;
207		/*
208		 * Currently hardcoded to 1 in Linux/SCSI code..
209		 */
210		dev->dev_attrib.max_unmap_block_desc_count = 1;
211		dev->dev_attrib.unmap_granularity = 1;
212		dev->dev_attrib.unmap_granularity_alignment = 0;
213
214		/*
215		 * Limit WRITE_SAME w/ UNMAP=0 emulation to 8k Number of LBAs (NoLB)
216		 * based upon struct iovec limit for vfs_writev()
217		 */
218		dev->dev_attrib.max_write_same_len = 0x1000;
219	}
220
221	dev->dev_attrib.hw_block_size = fd_dev->fd_block_size;
222	dev->dev_attrib.max_bytes_per_io = FD_MAX_BYTES;
223	dev->dev_attrib.hw_max_sectors = FD_MAX_BYTES / fd_dev->fd_block_size;
224	dev->dev_attrib.hw_queue_depth = FD_MAX_DEVICE_QUEUE_DEPTH;
225
226	if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
227		pr_debug("FILEIO: Forcing setting of emulate_write_cache=1"
228			" with FDBD_HAS_BUFFERED_IO_WCE\n");
229		dev->dev_attrib.emulate_write_cache = 1;
230	}
231
232	fd_dev->fd_dev_id = fd_host->fd_host_dev_id_count++;
233	fd_dev->fd_queue_depth = dev->queue_depth;
234
235	pr_debug("CORE_FILE[%u] - Added TCM FILEIO Device ID: %u at %s,"
236		" %llu total bytes\n", fd_host->fd_host_id, fd_dev->fd_dev_id,
237			fd_dev->fd_dev_name, fd_dev->fd_dev_size);
238
239	return 0;
240fail:
241	if (fd_dev->fd_file) {
242		filp_close(fd_dev->fd_file, NULL);
243		fd_dev->fd_file = NULL;
244	}
245	return ret;
246}
247
248static void fd_free_device(struct se_device *dev)
249{
250	struct fd_dev *fd_dev = FD_DEV(dev);
251
252	if (fd_dev->fd_file) {
253		filp_close(fd_dev->fd_file, NULL);
254		fd_dev->fd_file = NULL;
255	}
256
257	kfree(fd_dev);
258}
259
260static int fd_do_prot_rw(struct se_cmd *cmd, struct fd_prot *fd_prot,
261			 int is_write)
262{
263	struct se_device *se_dev = cmd->se_dev;
264	struct fd_dev *dev = FD_DEV(se_dev);
265	struct file *prot_fd = dev->fd_prot_file;
266	struct scatterlist *sg;
267	loff_t pos = (cmd->t_task_lba * se_dev->prot_length);
268	unsigned char *buf;
269	u32 prot_size, len, size;
270	int rc, ret = 1, i;
271
272	prot_size = (cmd->data_length / se_dev->dev_attrib.block_size) *
273		     se_dev->prot_length;
274
275	if (!is_write) {
276		fd_prot->prot_buf = vzalloc(prot_size);
277		if (!fd_prot->prot_buf) {
278			pr_err("Unable to allocate fd_prot->prot_buf\n");
279			return -ENOMEM;
280		}
281		buf = fd_prot->prot_buf;
282
283		fd_prot->prot_sg_nents = cmd->t_prot_nents;
284		fd_prot->prot_sg = kzalloc(sizeof(struct scatterlist) *
285					   fd_prot->prot_sg_nents, GFP_KERNEL);
286		if (!fd_prot->prot_sg) {
287			pr_err("Unable to allocate fd_prot->prot_sg\n");
288			vfree(fd_prot->prot_buf);
289			return -ENOMEM;
290		}
291		size = prot_size;
292
293		for_each_sg(fd_prot->prot_sg, sg, fd_prot->prot_sg_nents, i) {
294
295			len = min_t(u32, PAGE_SIZE, size);
296			sg_set_buf(sg, buf, len);
297			size -= len;
298			buf += len;
299		}
300	}
301
302	if (is_write) {
303		rc = kernel_write(prot_fd, fd_prot->prot_buf, prot_size, pos);
304		if (rc < 0 || prot_size != rc) {
305			pr_err("kernel_write() for fd_do_prot_rw failed:"
306			       " %d\n", rc);
307			ret = -EINVAL;
308		}
309	} else {
310		rc = kernel_read(prot_fd, pos, fd_prot->prot_buf, prot_size);
311		if (rc < 0) {
312			pr_err("kernel_read() for fd_do_prot_rw failed:"
313			       " %d\n", rc);
314			ret = -EINVAL;
315		}
316	}
317
318	if (is_write || ret < 0) {
319		kfree(fd_prot->prot_sg);
320		vfree(fd_prot->prot_buf);
321	}
322
323	return ret;
324}
325
326static int fd_do_rw(struct se_cmd *cmd, struct scatterlist *sgl,
327		u32 sgl_nents, int is_write)
328{
329	struct se_device *se_dev = cmd->se_dev;
330	struct fd_dev *dev = FD_DEV(se_dev);
331	struct file *fd = dev->fd_file;
332	struct scatterlist *sg;
333	struct iovec *iov;
334	mm_segment_t old_fs;
335	loff_t pos = (cmd->t_task_lba * se_dev->dev_attrib.block_size);
336	int ret = 0, i;
337
338	iov = kzalloc(sizeof(struct iovec) * sgl_nents, GFP_KERNEL);
339	if (!iov) {
340		pr_err("Unable to allocate fd_do_readv iov[]\n");
341		return -ENOMEM;
342	}
343
344	for_each_sg(sgl, sg, sgl_nents, i) {
345		iov[i].iov_len = sg->length;
346		iov[i].iov_base = kmap(sg_page(sg)) + sg->offset;
347	}
348
349	old_fs = get_fs();
350	set_fs(get_ds());
351
352	if (is_write)
353		ret = vfs_writev(fd, &iov[0], sgl_nents, &pos);
354	else
355		ret = vfs_readv(fd, &iov[0], sgl_nents, &pos);
356
357	set_fs(old_fs);
358
359	for_each_sg(sgl, sg, sgl_nents, i)
360		kunmap(sg_page(sg));
361
362	kfree(iov);
363
364	if (is_write) {
365		if (ret < 0 || ret != cmd->data_length) {
366			pr_err("%s() write returned %d\n", __func__, ret);
367			return (ret < 0 ? ret : -EINVAL);
368		}
369	} else {
370		/*
371		 * Return zeros and GOOD status even if the READ did not return
372		 * the expected virt_size for struct file w/o a backing struct
373		 * block_device.
374		 */
375		if (S_ISBLK(file_inode(fd)->i_mode)) {
376			if (ret < 0 || ret != cmd->data_length) {
377				pr_err("%s() returned %d, expecting %u for "
378						"S_ISBLK\n", __func__, ret,
379						cmd->data_length);
380				return (ret < 0 ? ret : -EINVAL);
381			}
382		} else {
383			if (ret < 0) {
384				pr_err("%s() returned %d for non S_ISBLK\n",
385						__func__, ret);
386				return ret;
387			}
388		}
389	}
390	return 1;
391}
392
393static sense_reason_t
394fd_execute_sync_cache(struct se_cmd *cmd)
395{
396	struct se_device *dev = cmd->se_dev;
397	struct fd_dev *fd_dev = FD_DEV(dev);
398	int immed = (cmd->t_task_cdb[1] & 0x2);
399	loff_t start, end;
400	int ret;
401
402	/*
403	 * If the Immediate bit is set, queue up the GOOD response
404	 * for this SYNCHRONIZE_CACHE op
405	 */
406	if (immed)
407		target_complete_cmd(cmd, SAM_STAT_GOOD);
408
409	/*
410	 * Determine if we will be flushing the entire device.
411	 */
412	if (cmd->t_task_lba == 0 && cmd->data_length == 0) {
413		start = 0;
414		end = LLONG_MAX;
415	} else {
416		start = cmd->t_task_lba * dev->dev_attrib.block_size;
417		if (cmd->data_length)
418			end = start + cmd->data_length - 1;
419		else
420			end = LLONG_MAX;
421	}
422
423	ret = vfs_fsync_range(fd_dev->fd_file, start, end, 1);
424	if (ret != 0)
425		pr_err("FILEIO: vfs_fsync_range() failed: %d\n", ret);
426
427	if (immed)
428		return 0;
429
430	if (ret)
431		target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
432	else
433		target_complete_cmd(cmd, SAM_STAT_GOOD);
434
435	return 0;
436}
437
438static unsigned char *
439fd_setup_write_same_buf(struct se_cmd *cmd, struct scatterlist *sg,
440		    unsigned int len)
441{
442	struct se_device *se_dev = cmd->se_dev;
443	unsigned int block_size = se_dev->dev_attrib.block_size;
444	unsigned int i = 0, end;
445	unsigned char *buf, *p, *kmap_buf;
446
447	buf = kzalloc(min_t(unsigned int, len, PAGE_SIZE), GFP_KERNEL);
448	if (!buf) {
449		pr_err("Unable to allocate fd_execute_write_same buf\n");
450		return NULL;
451	}
452
453	kmap_buf = kmap(sg_page(sg)) + sg->offset;
454	if (!kmap_buf) {
455		pr_err("kmap() failed in fd_setup_write_same\n");
456		kfree(buf);
457		return NULL;
458	}
459	/*
460	 * Fill local *buf to contain multiple WRITE_SAME blocks up to
461	 * min(len, PAGE_SIZE)
462	 */
463	p = buf;
464	end = min_t(unsigned int, len, PAGE_SIZE);
465
466	while (i < end) {
467		memcpy(p, kmap_buf, block_size);
468
469		i += block_size;
470		p += block_size;
471	}
472	kunmap(sg_page(sg));
473
474	return buf;
475}
476
477static sense_reason_t
478fd_execute_write_same(struct se_cmd *cmd)
479{
480	struct se_device *se_dev = cmd->se_dev;
481	struct fd_dev *fd_dev = FD_DEV(se_dev);
482	struct file *f = fd_dev->fd_file;
483	struct scatterlist *sg;
484	struct iovec *iov;
485	mm_segment_t old_fs;
486	sector_t nolb = sbc_get_write_same_sectors(cmd);
487	loff_t pos = cmd->t_task_lba * se_dev->dev_attrib.block_size;
488	unsigned int len, len_tmp, iov_num;
489	int i, rc;
490	unsigned char *buf;
491
492	if (!nolb) {
493		target_complete_cmd(cmd, SAM_STAT_GOOD);
494		return 0;
495	}
496	sg = &cmd->t_data_sg[0];
497
498	if (cmd->t_data_nents > 1 ||
499	    sg->length != cmd->se_dev->dev_attrib.block_size) {
500		pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
501			" block_size: %u\n", cmd->t_data_nents, sg->length,
502			cmd->se_dev->dev_attrib.block_size);
503		return TCM_INVALID_CDB_FIELD;
504	}
505
506	len = len_tmp = nolb * se_dev->dev_attrib.block_size;
507	iov_num = DIV_ROUND_UP(len, PAGE_SIZE);
508
509	buf = fd_setup_write_same_buf(cmd, sg, len);
510	if (!buf)
511		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
512
513	iov = vzalloc(sizeof(struct iovec) * iov_num);
514	if (!iov) {
515		pr_err("Unable to allocate fd_execute_write_same iovecs\n");
516		kfree(buf);
517		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
518	}
519	/*
520	 * Map the single fabric received scatterlist block now populated
521	 * in *buf into each iovec for I/O submission.
522	 */
523	for (i = 0; i < iov_num; i++) {
524		iov[i].iov_base = buf;
525		iov[i].iov_len = min_t(unsigned int, len_tmp, PAGE_SIZE);
526		len_tmp -= iov[i].iov_len;
527	}
528
529	old_fs = get_fs();
530	set_fs(get_ds());
531	rc = vfs_writev(f, &iov[0], iov_num, &pos);
532	set_fs(old_fs);
533
534	vfree(iov);
535	kfree(buf);
536
537	if (rc < 0 || rc != len) {
538		pr_err("vfs_writev() returned %d for write same\n", rc);
539		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
540	}
541
542	target_complete_cmd(cmd, SAM_STAT_GOOD);
543	return 0;
544}
545
546static sense_reason_t
547fd_do_unmap(struct se_cmd *cmd, void *priv, sector_t lba, sector_t nolb)
548{
549	struct file *file = priv;
550	struct inode *inode = file->f_mapping->host;
551	int ret;
552
553	if (S_ISBLK(inode->i_mode)) {
554		/* The backend is block device, use discard */
555		struct block_device *bdev = inode->i_bdev;
556
557		ret = blkdev_issue_discard(bdev, lba,
558				nolb, GFP_KERNEL, 0);
559		if (ret < 0) {
560			pr_warn("FILEIO: blkdev_issue_discard() failed: %d\n",
561				ret);
562			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
563		}
564	} else {
565		/* The backend is normal file, use fallocate */
566		struct se_device *se_dev = cmd->se_dev;
567		loff_t pos = lba * se_dev->dev_attrib.block_size;
568		unsigned int len = nolb * se_dev->dev_attrib.block_size;
569		int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
570
571		if (!file->f_op->fallocate)
572			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
573
574		ret = file->f_op->fallocate(file, mode, pos, len);
575		if (ret < 0) {
576			pr_warn("FILEIO: fallocate() failed: %d\n", ret);
577			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
578		}
579	}
580
581	return 0;
582}
583
584static sense_reason_t
585fd_execute_write_same_unmap(struct se_cmd *cmd)
586{
587	struct se_device *se_dev = cmd->se_dev;
588	struct fd_dev *fd_dev = FD_DEV(se_dev);
589	struct file *file = fd_dev->fd_file;
590	sector_t lba = cmd->t_task_lba;
591	sector_t nolb = sbc_get_write_same_sectors(cmd);
592	int ret;
593
594	if (!nolb) {
595		target_complete_cmd(cmd, SAM_STAT_GOOD);
596		return 0;
597	}
598
599	ret = fd_do_unmap(cmd, file, lba, nolb);
600	if (ret)
601		return ret;
602
603	target_complete_cmd(cmd, GOOD);
604	return 0;
605}
606
607static sense_reason_t
608fd_execute_unmap(struct se_cmd *cmd)
609{
610	struct file *file = FD_DEV(cmd->se_dev)->fd_file;
611
612	return sbc_execute_unmap(cmd, fd_do_unmap, file);
613}
614
615static sense_reason_t
616fd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
617	      enum dma_data_direction data_direction)
618{
619	struct se_device *dev = cmd->se_dev;
620	struct fd_prot fd_prot;
621	sense_reason_t rc;
622	int ret = 0;
623
624	/*
625	 * Call vectorized fileio functions to map struct scatterlist
626	 * physical memory addresses to struct iovec virtual memory.
627	 */
628	if (data_direction == DMA_FROM_DEVICE) {
629		memset(&fd_prot, 0, sizeof(struct fd_prot));
630
631		if (cmd->prot_type) {
632			ret = fd_do_prot_rw(cmd, &fd_prot, false);
633			if (ret < 0)
634				return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
635		}
636
637		ret = fd_do_rw(cmd, sgl, sgl_nents, 0);
638
639		if (ret > 0 && cmd->prot_type) {
640			u32 sectors = cmd->data_length / dev->dev_attrib.block_size;
641
642			rc = sbc_dif_verify_read(cmd, cmd->t_task_lba, sectors,
643						 0, fd_prot.prot_sg, 0);
644			if (rc) {
645				kfree(fd_prot.prot_sg);
646				vfree(fd_prot.prot_buf);
647				return rc;
648			}
649			kfree(fd_prot.prot_sg);
650			vfree(fd_prot.prot_buf);
651		}
652	} else {
653		memset(&fd_prot, 0, sizeof(struct fd_prot));
654
655		if (cmd->prot_type) {
656			u32 sectors = cmd->data_length / dev->dev_attrib.block_size;
657
658			ret = fd_do_prot_rw(cmd, &fd_prot, false);
659			if (ret < 0)
660				return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
661
662			rc = sbc_dif_verify_write(cmd, cmd->t_task_lba, sectors,
663						  0, fd_prot.prot_sg, 0);
664			if (rc) {
665				kfree(fd_prot.prot_sg);
666				vfree(fd_prot.prot_buf);
667				return rc;
668			}
669		}
670
671		ret = fd_do_rw(cmd, sgl, sgl_nents, 1);
672		/*
673		 * Perform implicit vfs_fsync_range() for fd_do_writev() ops
674		 * for SCSI WRITEs with Forced Unit Access (FUA) set.
675		 * Allow this to happen independent of WCE=0 setting.
676		 */
677		if (ret > 0 &&
678		    dev->dev_attrib.emulate_fua_write > 0 &&
679		    (cmd->se_cmd_flags & SCF_FUA)) {
680			struct fd_dev *fd_dev = FD_DEV(dev);
681			loff_t start = cmd->t_task_lba *
682				dev->dev_attrib.block_size;
683			loff_t end;
684
685			if (cmd->data_length)
686				end = start + cmd->data_length - 1;
687			else
688				end = LLONG_MAX;
689
690			vfs_fsync_range(fd_dev->fd_file, start, end, 1);
691		}
692
693		if (ret > 0 && cmd->prot_type) {
694			ret = fd_do_prot_rw(cmd, &fd_prot, true);
695			if (ret < 0)
696				return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
697		}
698	}
699
700	if (ret < 0) {
701		kfree(fd_prot.prot_sg);
702		vfree(fd_prot.prot_buf);
703		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
704	}
705
706	if (ret)
707		target_complete_cmd(cmd, SAM_STAT_GOOD);
708	return 0;
709}
710
711enum {
712	Opt_fd_dev_name, Opt_fd_dev_size, Opt_fd_buffered_io, Opt_err
713};
714
715static match_table_t tokens = {
716	{Opt_fd_dev_name, "fd_dev_name=%s"},
717	{Opt_fd_dev_size, "fd_dev_size=%s"},
718	{Opt_fd_buffered_io, "fd_buffered_io=%d"},
719	{Opt_err, NULL}
720};
721
722static ssize_t fd_set_configfs_dev_params(struct se_device *dev,
723		const char *page, ssize_t count)
724{
725	struct fd_dev *fd_dev = FD_DEV(dev);
726	char *orig, *ptr, *arg_p, *opts;
727	substring_t args[MAX_OPT_ARGS];
728	int ret = 0, arg, token;
729
730	opts = kstrdup(page, GFP_KERNEL);
731	if (!opts)
732		return -ENOMEM;
733
734	orig = opts;
735
736	while ((ptr = strsep(&opts, ",\n")) != NULL) {
737		if (!*ptr)
738			continue;
739
740		token = match_token(ptr, tokens, args);
741		switch (token) {
742		case Opt_fd_dev_name:
743			if (match_strlcpy(fd_dev->fd_dev_name, &args[0],
744				FD_MAX_DEV_NAME) == 0) {
745				ret = -EINVAL;
746				break;
747			}
748			pr_debug("FILEIO: Referencing Path: %s\n",
749					fd_dev->fd_dev_name);
750			fd_dev->fbd_flags |= FBDF_HAS_PATH;
751			break;
752		case Opt_fd_dev_size:
753			arg_p = match_strdup(&args[0]);
754			if (!arg_p) {
755				ret = -ENOMEM;
756				break;
757			}
758			ret = kstrtoull(arg_p, 0, &fd_dev->fd_dev_size);
759			kfree(arg_p);
760			if (ret < 0) {
761				pr_err("kstrtoull() failed for"
762						" fd_dev_size=\n");
763				goto out;
764			}
765			pr_debug("FILEIO: Referencing Size: %llu"
766					" bytes\n", fd_dev->fd_dev_size);
767			fd_dev->fbd_flags |= FBDF_HAS_SIZE;
768			break;
769		case Opt_fd_buffered_io:
770			ret = match_int(args, &arg);
771			if (ret)
772				goto out;
773			if (arg != 1) {
774				pr_err("bogus fd_buffered_io=%d value\n", arg);
775				ret = -EINVAL;
776				goto out;
777			}
778
779			pr_debug("FILEIO: Using buffered I/O"
780				" operations for struct fd_dev\n");
781
782			fd_dev->fbd_flags |= FDBD_HAS_BUFFERED_IO_WCE;
783			break;
784		default:
785			break;
786		}
787	}
788
789out:
790	kfree(orig);
791	return (!ret) ? count : ret;
792}
793
794static ssize_t fd_show_configfs_dev_params(struct se_device *dev, char *b)
795{
796	struct fd_dev *fd_dev = FD_DEV(dev);
797	ssize_t bl = 0;
798
799	bl = sprintf(b + bl, "TCM FILEIO ID: %u", fd_dev->fd_dev_id);
800	bl += sprintf(b + bl, "        File: %s  Size: %llu  Mode: %s\n",
801		fd_dev->fd_dev_name, fd_dev->fd_dev_size,
802		(fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) ?
803		"Buffered-WCE" : "O_DSYNC");
804	return bl;
805}
806
807static sector_t fd_get_blocks(struct se_device *dev)
808{
809	struct fd_dev *fd_dev = FD_DEV(dev);
810	struct file *f = fd_dev->fd_file;
811	struct inode *i = f->f_mapping->host;
812	unsigned long long dev_size;
813	/*
814	 * When using a file that references an underlying struct block_device,
815	 * ensure dev_size is always based on the current inode size in order
816	 * to handle underlying block_device resize operations.
817	 */
818	if (S_ISBLK(i->i_mode))
819		dev_size = i_size_read(i);
820	else
821		dev_size = fd_dev->fd_dev_size;
822
823	return div_u64(dev_size - dev->dev_attrib.block_size,
824		       dev->dev_attrib.block_size);
825}
826
827static int fd_init_prot(struct se_device *dev)
828{
829	struct fd_dev *fd_dev = FD_DEV(dev);
830	struct file *prot_file, *file = fd_dev->fd_file;
831	struct inode *inode;
832	int ret, flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
833	char buf[FD_MAX_DEV_PROT_NAME];
834
835	if (!file) {
836		pr_err("Unable to locate fd_dev->fd_file\n");
837		return -ENODEV;
838	}
839
840	inode = file->f_mapping->host;
841	if (S_ISBLK(inode->i_mode)) {
842		pr_err("FILEIO Protection emulation only supported on"
843		       " !S_ISBLK\n");
844		return -ENOSYS;
845	}
846
847	if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE)
848		flags &= ~O_DSYNC;
849
850	snprintf(buf, FD_MAX_DEV_PROT_NAME, "%s.protection",
851		 fd_dev->fd_dev_name);
852
853	prot_file = filp_open(buf, flags, 0600);
854	if (IS_ERR(prot_file)) {
855		pr_err("filp_open(%s) failed\n", buf);
856		ret = PTR_ERR(prot_file);
857		return ret;
858	}
859	fd_dev->fd_prot_file = prot_file;
860
861	return 0;
862}
863
864static int fd_format_prot(struct se_device *dev)
865{
866	struct fd_dev *fd_dev = FD_DEV(dev);
867	struct file *prot_fd = fd_dev->fd_prot_file;
868	sector_t prot_length, prot;
869	unsigned char *buf;
870	loff_t pos = 0;
871	int unit_size = FDBD_FORMAT_UNIT_SIZE * dev->dev_attrib.block_size;
872	int rc, ret = 0, size, len;
873
874	if (!dev->dev_attrib.pi_prot_type) {
875		pr_err("Unable to format_prot while pi_prot_type == 0\n");
876		return -ENODEV;
877	}
878	if (!prot_fd) {
879		pr_err("Unable to locate fd_dev->fd_prot_file\n");
880		return -ENODEV;
881	}
882
883	buf = vzalloc(unit_size);
884	if (!buf) {
885		pr_err("Unable to allocate FILEIO prot buf\n");
886		return -ENOMEM;
887	}
888	prot_length = (dev->transport->get_blocks(dev) + 1) * dev->prot_length;
889	size = prot_length;
890
891	pr_debug("Using FILEIO prot_length: %llu\n",
892		 (unsigned long long)prot_length);
893
894	memset(buf, 0xff, unit_size);
895	for (prot = 0; prot < prot_length; prot += unit_size) {
896		len = min(unit_size, size);
897		rc = kernel_write(prot_fd, buf, len, pos);
898		if (rc != len) {
899			pr_err("vfs_write to prot file failed: %d\n", rc);
900			ret = -ENODEV;
901			goto out;
902		}
903		pos += len;
904		size -= len;
905	}
906
907out:
908	vfree(buf);
909	return ret;
910}
911
912static void fd_free_prot(struct se_device *dev)
913{
914	struct fd_dev *fd_dev = FD_DEV(dev);
915
916	if (!fd_dev->fd_prot_file)
917		return;
918
919	filp_close(fd_dev->fd_prot_file, NULL);
920	fd_dev->fd_prot_file = NULL;
921}
922
923static struct sbc_ops fd_sbc_ops = {
924	.execute_rw		= fd_execute_rw,
925	.execute_sync_cache	= fd_execute_sync_cache,
926	.execute_write_same	= fd_execute_write_same,
927	.execute_write_same_unmap = fd_execute_write_same_unmap,
928	.execute_unmap		= fd_execute_unmap,
929};
930
931static sense_reason_t
932fd_parse_cdb(struct se_cmd *cmd)
933{
934	return sbc_parse_cdb(cmd, &fd_sbc_ops);
935}
936
937static struct se_subsystem_api fileio_template = {
938	.name			= "fileio",
939	.inquiry_prod		= "FILEIO",
940	.inquiry_rev		= FD_VERSION,
941	.owner			= THIS_MODULE,
942	.transport_type		= TRANSPORT_PLUGIN_VHBA_PDEV,
943	.attach_hba		= fd_attach_hba,
944	.detach_hba		= fd_detach_hba,
945	.alloc_device		= fd_alloc_device,
946	.configure_device	= fd_configure_device,
947	.free_device		= fd_free_device,
948	.parse_cdb		= fd_parse_cdb,
949	.set_configfs_dev_params = fd_set_configfs_dev_params,
950	.show_configfs_dev_params = fd_show_configfs_dev_params,
951	.get_device_type	= sbc_get_device_type,
952	.get_blocks		= fd_get_blocks,
953	.init_prot		= fd_init_prot,
954	.format_prot		= fd_format_prot,
955	.free_prot		= fd_free_prot,
956};
957
958static int __init fileio_module_init(void)
959{
960	return transport_subsystem_register(&fileio_template);
961}
962
963static void __exit fileio_module_exit(void)
964{
965	transport_subsystem_release(&fileio_template);
966}
967
968MODULE_DESCRIPTION("TCM FILEIO subsystem plugin");
969MODULE_AUTHOR("nab@Linux-iSCSI.org");
970MODULE_LICENSE("GPL");
971
972module_init(fileio_module_init);
973module_exit(fileio_module_exit);
974