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/vmalloc.h>
34#include <linux/falloc.h>
35#include <linux/uio.h>
36#include <scsi/scsi_proto.h>
37#include <asm/unaligned.h>
38
39#include <target/target_core_base.h>
40#include <target/target_core_backend.h>
41
42#include "target_core_file.h"
43
44static inline struct fd_dev *FD_DEV(struct se_device *dev)
45{
46 return container_of(dev, struct fd_dev, dev);
47}
48
49static int fd_attach_hba(struct se_hba *hba, u32 host_id)
50{
51 struct fd_host *fd_host;
52
53 fd_host = kzalloc(sizeof(struct fd_host), GFP_KERNEL);
54 if (!fd_host) {
55 pr_err("Unable to allocate memory for struct fd_host\n");
56 return -ENOMEM;
57 }
58
59 fd_host->fd_host_id = host_id;
60
61 hba->hba_ptr = fd_host;
62
63 pr_debug("CORE_HBA[%d] - TCM FILEIO HBA Driver %s on Generic"
64 " Target Core Stack %s\n", hba->hba_id, FD_VERSION,
65 TARGET_CORE_VERSION);
66 pr_debug("CORE_HBA[%d] - Attached FILEIO HBA: %u to Generic\n",
67 hba->hba_id, fd_host->fd_host_id);
68
69 return 0;
70}
71
72static void fd_detach_hba(struct se_hba *hba)
73{
74 struct fd_host *fd_host = hba->hba_ptr;
75
76 pr_debug("CORE_HBA[%d] - Detached FILEIO HBA: %u from Generic"
77 " Target Core\n", hba->hba_id, fd_host->fd_host_id);
78
79 kfree(fd_host);
80 hba->hba_ptr = NULL;
81}
82
83static struct se_device *fd_alloc_device(struct se_hba *hba, const char *name)
84{
85 struct fd_dev *fd_dev;
86 struct fd_host *fd_host = hba->hba_ptr;
87
88 fd_dev = kzalloc(sizeof(struct fd_dev), GFP_KERNEL);
89 if (!fd_dev) {
90 pr_err("Unable to allocate memory for struct fd_dev\n");
91 return NULL;
92 }
93
94 fd_dev->fd_host = fd_host;
95
96 pr_debug("FILEIO: Allocated fd_dev for %p\n", name);
97
98 return &fd_dev->dev;
99}
100
101static int fd_configure_device(struct se_device *dev)
102{
103 struct fd_dev *fd_dev = FD_DEV(dev);
104 struct fd_host *fd_host = dev->se_hba->hba_ptr;
105 struct file *file;
106 struct inode *inode = NULL;
107 int flags, ret = -EINVAL;
108
109 if (!(fd_dev->fbd_flags & FBDF_HAS_PATH)) {
110 pr_err("Missing fd_dev_name=\n");
111 return -EINVAL;
112 }
113
114 /*
115 * Use O_DSYNC by default instead of O_SYNC to forgo syncing
116 * of pure timestamp updates.
117 */
118 flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
119
120 /*
121 * Optionally allow fd_buffered_io=1 to be enabled for people
122 * who want use the fs buffer cache as an WriteCache mechanism.
123 *
124 * This means that in event of a hard failure, there is a risk
125 * of silent data-loss if the SCSI client has *not* performed a
126 * forced unit access (FUA) write, or issued SYNCHRONIZE_CACHE
127 * to write-out the entire device cache.
128 */
129 if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
130 pr_debug("FILEIO: Disabling O_DSYNC, using buffered FILEIO\n");
131 flags &= ~O_DSYNC;
132 }
133
134 file = filp_open(fd_dev->fd_dev_name, flags, 0600);
135 if (IS_ERR(file)) {
136 pr_err("filp_open(%s) failed\n", fd_dev->fd_dev_name);
137 ret = PTR_ERR(file);
138 goto fail;
139 }
140 fd_dev->fd_file = file;
141 /*
142 * If using a block backend with this struct file, we extract
143 * fd_dev->fd_[block,dev]_size from struct block_device.
144 *
145 * Otherwise, we use the passed fd_size= from configfs
146 */
147 inode = file->f_mapping->host;
148 if (S_ISBLK(inode->i_mode)) {
149 struct request_queue *q = bdev_get_queue(inode->i_bdev);
150 unsigned long long dev_size;
151
152 fd_dev->fd_block_size = bdev_logical_block_size(inode->i_bdev);
153 /*
154 * Determine the number of bytes from i_size_read() minus
155 * one (1) logical sector from underlying struct block_device
156 */
157 dev_size = (i_size_read(file->f_mapping->host) -
158 fd_dev->fd_block_size);
159
160 pr_debug("FILEIO: Using size: %llu bytes from struct"
161 " block_device blocks: %llu logical_block_size: %d\n",
162 dev_size, div_u64(dev_size, fd_dev->fd_block_size),
163 fd_dev->fd_block_size);
164
165 if (target_configure_unmap_from_queue(&dev->dev_attrib, q))
166 pr_debug("IFILE: BLOCK Discard support available,"
167 " disabled by default\n");
168 /*
169 * Enable write same emulation for IBLOCK and use 0xFFFF as
170 * the smaller WRITE_SAME(10) only has a two-byte block count.
171 */
172 dev->dev_attrib.max_write_same_len = 0xFFFF;
173
174 if (blk_queue_nonrot(q))
175 dev->dev_attrib.is_nonrot = 1;
176 } else {
177 if (!(fd_dev->fbd_flags & FBDF_HAS_SIZE)) {
178 pr_err("FILEIO: Missing fd_dev_size="
179 " parameter, and no backing struct"
180 " block_device\n");
181 goto fail;
182 }
183
184 fd_dev->fd_block_size = FD_BLOCKSIZE;
185 /*
186 * Limit UNMAP emulation to 8k Number of LBAs (NoLB)
187 */
188 dev->dev_attrib.max_unmap_lba_count = 0x2000;
189 /*
190 * Currently hardcoded to 1 in Linux/SCSI code..
191 */
192 dev->dev_attrib.max_unmap_block_desc_count = 1;
193 dev->dev_attrib.unmap_granularity = 1;
194 dev->dev_attrib.unmap_granularity_alignment = 0;
195
196 /*
197 * Limit WRITE_SAME w/ UNMAP=0 emulation to 8k Number of LBAs (NoLB)
198 * based upon struct iovec limit for vfs_writev()
199 */
200 dev->dev_attrib.max_write_same_len = 0x1000;
201 }
202
203 dev->dev_attrib.hw_block_size = fd_dev->fd_block_size;
204 dev->dev_attrib.max_bytes_per_io = FD_MAX_BYTES;
205 dev->dev_attrib.hw_max_sectors = FD_MAX_BYTES / fd_dev->fd_block_size;
206 dev->dev_attrib.hw_queue_depth = FD_MAX_DEVICE_QUEUE_DEPTH;
207
208 if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
209 pr_debug("FILEIO: Forcing setting of emulate_write_cache=1"
210 " with FDBD_HAS_BUFFERED_IO_WCE\n");
211 dev->dev_attrib.emulate_write_cache = 1;
212 }
213
214 fd_dev->fd_dev_id = fd_host->fd_host_dev_id_count++;
215 fd_dev->fd_queue_depth = dev->queue_depth;
216
217 pr_debug("CORE_FILE[%u] - Added TCM FILEIO Device ID: %u at %s,"
218 " %llu total bytes\n", fd_host->fd_host_id, fd_dev->fd_dev_id,
219 fd_dev->fd_dev_name, fd_dev->fd_dev_size);
220
221 return 0;
222fail:
223 if (fd_dev->fd_file) {
224 filp_close(fd_dev->fd_file, NULL);
225 fd_dev->fd_file = NULL;
226 }
227 return ret;
228}
229
230static void fd_dev_call_rcu(struct rcu_head *p)
231{
232 struct se_device *dev = container_of(p, struct se_device, rcu_head);
233 struct fd_dev *fd_dev = FD_DEV(dev);
234
235 kfree(fd_dev);
236}
237
238static void fd_free_device(struct se_device *dev)
239{
240 call_rcu(&dev->rcu_head, fd_dev_call_rcu);
241}
242
243static void fd_destroy_device(struct se_device *dev)
244{
245 struct fd_dev *fd_dev = FD_DEV(dev);
246
247 if (fd_dev->fd_file) {
248 filp_close(fd_dev->fd_file, NULL);
249 fd_dev->fd_file = NULL;
250 }
251}
252
253struct target_core_file_cmd {
254 unsigned long len;
255 struct se_cmd *cmd;
256 struct kiocb iocb;
257};
258
259static void cmd_rw_aio_complete(struct kiocb *iocb, long ret, long ret2)
260{
261 struct target_core_file_cmd *cmd;
262
263 cmd = container_of(iocb, struct target_core_file_cmd, iocb);
264
265 if (ret != cmd->len)
266 target_complete_cmd(cmd->cmd, SAM_STAT_CHECK_CONDITION);
267 else
268 target_complete_cmd(cmd->cmd, SAM_STAT_GOOD);
269
270 kfree(cmd);
271}
272
273static sense_reason_t
274fd_execute_rw_aio(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
275 enum dma_data_direction data_direction)
276{
277 int is_write = !(data_direction == DMA_FROM_DEVICE);
278 struct se_device *dev = cmd->se_dev;
279 struct fd_dev *fd_dev = FD_DEV(dev);
280 struct file *file = fd_dev->fd_file;
281 struct target_core_file_cmd *aio_cmd;
282 struct iov_iter iter = {};
283 struct scatterlist *sg;
284 struct bio_vec *bvec;
285 ssize_t len = 0;
286 int ret = 0, i;
287
288 aio_cmd = kmalloc(sizeof(struct target_core_file_cmd), GFP_KERNEL);
289 if (!aio_cmd)
290 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
291
292 bvec = kcalloc(sgl_nents, sizeof(struct bio_vec), GFP_KERNEL);
293 if (!bvec) {
294 kfree(aio_cmd);
295 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
296 }
297
298 for_each_sg(sgl, sg, sgl_nents, i) {
299 bvec[i].bv_page = sg_page(sg);
300 bvec[i].bv_len = sg->length;
301 bvec[i].bv_offset = sg->offset;
302
303 len += sg->length;
304 }
305
306 iov_iter_bvec(&iter, is_write, bvec, sgl_nents, len);
307
308 aio_cmd->cmd = cmd;
309 aio_cmd->len = len;
310 aio_cmd->iocb.ki_pos = cmd->t_task_lba * dev->dev_attrib.block_size;
311 aio_cmd->iocb.ki_filp = file;
312 aio_cmd->iocb.ki_complete = cmd_rw_aio_complete;
313 aio_cmd->iocb.ki_flags = IOCB_DIRECT;
314
315 if (is_write && (cmd->se_cmd_flags & SCF_FUA))
316 aio_cmd->iocb.ki_flags |= IOCB_DSYNC;
317
318 if (is_write)
319 ret = call_write_iter(file, &aio_cmd->iocb, &iter);
320 else
321 ret = call_read_iter(file, &aio_cmd->iocb, &iter);
322
323 kfree(bvec);
324
325 if (ret != -EIOCBQUEUED)
326 cmd_rw_aio_complete(&aio_cmd->iocb, ret, 0);
327
328 return 0;
329}
330
331static int fd_do_rw(struct se_cmd *cmd, struct file *fd,
332 u32 block_size, struct scatterlist *sgl,
333 u32 sgl_nents, u32 data_length, int is_write)
334{
335 struct scatterlist *sg;
336 struct iov_iter iter;
337 struct bio_vec *bvec;
338 ssize_t len = 0;
339 loff_t pos = (cmd->t_task_lba * block_size);
340 int ret = 0, i;
341
342 bvec = kcalloc(sgl_nents, sizeof(struct bio_vec), GFP_KERNEL);
343 if (!bvec) {
344 pr_err("Unable to allocate fd_do_readv iov[]\n");
345 return -ENOMEM;
346 }
347
348 for_each_sg(sgl, sg, sgl_nents, i) {
349 bvec[i].bv_page = sg_page(sg);
350 bvec[i].bv_len = sg->length;
351 bvec[i].bv_offset = sg->offset;
352
353 len += sg->length;
354 }
355
356 iov_iter_bvec(&iter, READ, bvec, sgl_nents, len);
357 if (is_write)
358 ret = vfs_iter_write(fd, &iter, &pos, 0);
359 else
360 ret = vfs_iter_read(fd, &iter, &pos, 0);
361
362 if (is_write) {
363 if (ret < 0 || ret != data_length) {
364 pr_err("%s() write returned %d\n", __func__, ret);
365 if (ret >= 0)
366 ret = -EINVAL;
367 }
368 } else {
369 /*
370 * Return zeros and GOOD status even if the READ did not return
371 * the expected virt_size for struct file w/o a backing struct
372 * block_device.
373 */
374 if (S_ISBLK(file_inode(fd)->i_mode)) {
375 if (ret < 0 || ret != data_length) {
376 pr_err("%s() returned %d, expecting %u for "
377 "S_ISBLK\n", __func__, ret,
378 data_length);
379 if (ret >= 0)
380 ret = -EINVAL;
381 }
382 } else {
383 if (ret < 0) {
384 pr_err("%s() returned %d for non S_ISBLK\n",
385 __func__, ret);
386 } else if (ret != data_length) {
387 /*
388 * Short read case:
389 * Probably some one truncate file under us.
390 * We must explicitly zero sg-pages to prevent
391 * expose uninizialized pages to userspace.
392 */
393 if (ret < data_length)
394 ret += iov_iter_zero(data_length - ret, &iter);
395 else
396 ret = -EINVAL;
397 }
398 }
399 }
400 kfree(bvec);
401 return ret;
402}
403
404static sense_reason_t
405fd_execute_sync_cache(struct se_cmd *cmd)
406{
407 struct se_device *dev = cmd->se_dev;
408 struct fd_dev *fd_dev = FD_DEV(dev);
409 int immed = (cmd->t_task_cdb[1] & 0x2);
410 loff_t start, end;
411 int ret;
412
413 /*
414 * If the Immediate bit is set, queue up the GOOD response
415 * for this SYNCHRONIZE_CACHE op
416 */
417 if (immed)
418 target_complete_cmd(cmd, SAM_STAT_GOOD);
419
420 /*
421 * Determine if we will be flushing the entire device.
422 */
423 if (cmd->t_task_lba == 0 && cmd->data_length == 0) {
424 start = 0;
425 end = LLONG_MAX;
426 } else {
427 start = cmd->t_task_lba * dev->dev_attrib.block_size;
428 if (cmd->data_length)
429 end = start + cmd->data_length - 1;
430 else
431 end = LLONG_MAX;
432 }
433
434 ret = vfs_fsync_range(fd_dev->fd_file, start, end, 1);
435 if (ret != 0)
436 pr_err("FILEIO: vfs_fsync_range() failed: %d\n", ret);
437
438 if (immed)
439 return 0;
440
441 if (ret)
442 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
443 else
444 target_complete_cmd(cmd, SAM_STAT_GOOD);
445
446 return 0;
447}
448
449static sense_reason_t
450fd_execute_write_same(struct se_cmd *cmd)
451{
452 struct se_device *se_dev = cmd->se_dev;
453 struct fd_dev *fd_dev = FD_DEV(se_dev);
454 loff_t pos = cmd->t_task_lba * se_dev->dev_attrib.block_size;
455 sector_t nolb = sbc_get_write_same_sectors(cmd);
456 struct iov_iter iter;
457 struct bio_vec *bvec;
458 unsigned int len = 0, i;
459 ssize_t ret;
460
461 if (!nolb) {
462 target_complete_cmd(cmd, SAM_STAT_GOOD);
463 return 0;
464 }
465 if (cmd->prot_op) {
466 pr_err("WRITE_SAME: Protection information with FILEIO"
467 " backends not supported\n");
468 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
469 }
470
471 if (cmd->t_data_nents > 1 ||
472 cmd->t_data_sg[0].length != cmd->se_dev->dev_attrib.block_size) {
473 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
474 " block_size: %u\n",
475 cmd->t_data_nents,
476 cmd->t_data_sg[0].length,
477 cmd->se_dev->dev_attrib.block_size);
478 return TCM_INVALID_CDB_FIELD;
479 }
480
481 bvec = kcalloc(nolb, sizeof(struct bio_vec), GFP_KERNEL);
482 if (!bvec)
483 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
484
485 for (i = 0; i < nolb; i++) {
486 bvec[i].bv_page = sg_page(&cmd->t_data_sg[0]);
487 bvec[i].bv_len = cmd->t_data_sg[0].length;
488 bvec[i].bv_offset = cmd->t_data_sg[0].offset;
489
490 len += se_dev->dev_attrib.block_size;
491 }
492
493 iov_iter_bvec(&iter, READ, bvec, nolb, len);
494 ret = vfs_iter_write(fd_dev->fd_file, &iter, &pos, 0);
495
496 kfree(bvec);
497 if (ret < 0 || ret != len) {
498 pr_err("vfs_iter_write() returned %zd for write same\n", ret);
499 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
500 }
501
502 target_complete_cmd(cmd, SAM_STAT_GOOD);
503 return 0;
504}
505
506static int
507fd_do_prot_fill(struct se_device *se_dev, sector_t lba, sector_t nolb,
508 void *buf, size_t bufsize)
509{
510 struct fd_dev *fd_dev = FD_DEV(se_dev);
511 struct file *prot_fd = fd_dev->fd_prot_file;
512 sector_t prot_length, prot;
513 loff_t pos = lba * se_dev->prot_length;
514
515 if (!prot_fd) {
516 pr_err("Unable to locate fd_dev->fd_prot_file\n");
517 return -ENODEV;
518 }
519
520 prot_length = nolb * se_dev->prot_length;
521
522 for (prot = 0; prot < prot_length;) {
523 sector_t len = min_t(sector_t, bufsize, prot_length - prot);
524 ssize_t ret = kernel_write(prot_fd, buf, len, &pos);
525
526 if (ret != len) {
527 pr_err("vfs_write to prot file failed: %zd\n", ret);
528 return ret < 0 ? ret : -ENODEV;
529 }
530 prot += ret;
531 }
532
533 return 0;
534}
535
536static int
537fd_do_prot_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
538{
539 void *buf;
540 int rc;
541
542 buf = (void *)__get_free_page(GFP_KERNEL);
543 if (!buf) {
544 pr_err("Unable to allocate FILEIO prot buf\n");
545 return -ENOMEM;
546 }
547 memset(buf, 0xff, PAGE_SIZE);
548
549 rc = fd_do_prot_fill(cmd->se_dev, lba, nolb, buf, PAGE_SIZE);
550
551 free_page((unsigned long)buf);
552
553 return rc;
554}
555
556static sense_reason_t
557fd_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
558{
559 struct file *file = FD_DEV(cmd->se_dev)->fd_file;
560 struct inode *inode = file->f_mapping->host;
561 int ret;
562
563 if (!nolb) {
564 return 0;
565 }
566
567 if (cmd->se_dev->dev_attrib.pi_prot_type) {
568 ret = fd_do_prot_unmap(cmd, lba, nolb);
569 if (ret)
570 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
571 }
572
573 if (S_ISBLK(inode->i_mode)) {
574 /* The backend is block device, use discard */
575 struct block_device *bdev = inode->i_bdev;
576 struct se_device *dev = cmd->se_dev;
577
578 ret = blkdev_issue_discard(bdev,
579 target_to_linux_sector(dev, lba),
580 target_to_linux_sector(dev, nolb),
581 GFP_KERNEL, 0);
582 if (ret < 0) {
583 pr_warn("FILEIO: blkdev_issue_discard() failed: %d\n",
584 ret);
585 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
586 }
587 } else {
588 /* The backend is normal file, use fallocate */
589 struct se_device *se_dev = cmd->se_dev;
590 loff_t pos = lba * se_dev->dev_attrib.block_size;
591 unsigned int len = nolb * se_dev->dev_attrib.block_size;
592 int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
593
594 if (!file->f_op->fallocate)
595 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
596
597 ret = file->f_op->fallocate(file, mode, pos, len);
598 if (ret < 0) {
599 pr_warn("FILEIO: fallocate() failed: %d\n", ret);
600 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
601 }
602 }
603
604 return 0;
605}
606
607static sense_reason_t
608fd_execute_rw_buffered(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
609 enum dma_data_direction data_direction)
610{
611 struct se_device *dev = cmd->se_dev;
612 struct fd_dev *fd_dev = FD_DEV(dev);
613 struct file *file = fd_dev->fd_file;
614 struct file *pfile = fd_dev->fd_prot_file;
615 sense_reason_t rc;
616 int ret = 0;
617 /*
618 * Call vectorized fileio functions to map struct scatterlist
619 * physical memory addresses to struct iovec virtual memory.
620 */
621 if (data_direction == DMA_FROM_DEVICE) {
622 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
623 ret = fd_do_rw(cmd, pfile, dev->prot_length,
624 cmd->t_prot_sg, cmd->t_prot_nents,
625 cmd->prot_length, 0);
626 if (ret < 0)
627 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
628 }
629
630 ret = fd_do_rw(cmd, file, dev->dev_attrib.block_size,
631 sgl, sgl_nents, cmd->data_length, 0);
632
633 if (ret > 0 && cmd->prot_type && dev->dev_attrib.pi_prot_type &&
634 dev->dev_attrib.pi_prot_verify) {
635 u32 sectors = cmd->data_length >>
636 ilog2(dev->dev_attrib.block_size);
637
638 rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors,
639 0, cmd->t_prot_sg, 0);
640 if (rc)
641 return rc;
642 }
643 } else {
644 if (cmd->prot_type && dev->dev_attrib.pi_prot_type &&
645 dev->dev_attrib.pi_prot_verify) {
646 u32 sectors = cmd->data_length >>
647 ilog2(dev->dev_attrib.block_size);
648
649 rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors,
650 0, cmd->t_prot_sg, 0);
651 if (rc)
652 return rc;
653 }
654
655 ret = fd_do_rw(cmd, file, dev->dev_attrib.block_size,
656 sgl, sgl_nents, cmd->data_length, 1);
657 /*
658 * Perform implicit vfs_fsync_range() for fd_do_writev() ops
659 * for SCSI WRITEs with Forced Unit Access (FUA) set.
660 * Allow this to happen independent of WCE=0 setting.
661 */
662 if (ret > 0 && (cmd->se_cmd_flags & SCF_FUA)) {
663 loff_t start = cmd->t_task_lba *
664 dev->dev_attrib.block_size;
665 loff_t end;
666
667 if (cmd->data_length)
668 end = start + cmd->data_length - 1;
669 else
670 end = LLONG_MAX;
671
672 vfs_fsync_range(fd_dev->fd_file, start, end, 1);
673 }
674
675 if (ret > 0 && cmd->prot_type && dev->dev_attrib.pi_prot_type) {
676 ret = fd_do_rw(cmd, pfile, dev->prot_length,
677 cmd->t_prot_sg, cmd->t_prot_nents,
678 cmd->prot_length, 1);
679 if (ret < 0)
680 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
681 }
682 }
683
684 if (ret < 0)
685 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
686
687 target_complete_cmd(cmd, SAM_STAT_GOOD);
688 return 0;
689}
690
691static sense_reason_t
692fd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
693 enum dma_data_direction data_direction)
694{
695 struct se_device *dev = cmd->se_dev;
696 struct fd_dev *fd_dev = FD_DEV(dev);
697
698 /*
699 * We are currently limited by the number of iovecs (2048) per
700 * single vfs_[writev,readv] call.
701 */
702 if (cmd->data_length > FD_MAX_BYTES) {
703 pr_err("FILEIO: Not able to process I/O of %u bytes due to"
704 "FD_MAX_BYTES: %u iovec count limitation\n",
705 cmd->data_length, FD_MAX_BYTES);
706 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
707 }
708
709 if (fd_dev->fbd_flags & FDBD_HAS_ASYNC_IO)
710 return fd_execute_rw_aio(cmd, sgl, sgl_nents, data_direction);
711 return fd_execute_rw_buffered(cmd, sgl, sgl_nents, data_direction);
712}
713
714enum {
715 Opt_fd_dev_name, Opt_fd_dev_size, Opt_fd_buffered_io,
716 Opt_fd_async_io, Opt_err
717};
718
719static match_table_t tokens = {
720 {Opt_fd_dev_name, "fd_dev_name=%s"},
721 {Opt_fd_dev_size, "fd_dev_size=%s"},
722 {Opt_fd_buffered_io, "fd_buffered_io=%d"},
723 {Opt_fd_async_io, "fd_async_io=%d"},
724 {Opt_err, NULL}
725};
726
727static ssize_t fd_set_configfs_dev_params(struct se_device *dev,
728 const char *page, ssize_t count)
729{
730 struct fd_dev *fd_dev = FD_DEV(dev);
731 char *orig, *ptr, *arg_p, *opts;
732 substring_t args[MAX_OPT_ARGS];
733 int ret = 0, arg, token;
734
735 opts = kstrdup(page, GFP_KERNEL);
736 if (!opts)
737 return -ENOMEM;
738
739 orig = opts;
740
741 while ((ptr = strsep(&opts, ",\n")) != NULL) {
742 if (!*ptr)
743 continue;
744
745 token = match_token(ptr, tokens, args);
746 switch (token) {
747 case Opt_fd_dev_name:
748 if (match_strlcpy(fd_dev->fd_dev_name, &args[0],
749 FD_MAX_DEV_NAME) == 0) {
750 ret = -EINVAL;
751 break;
752 }
753 pr_debug("FILEIO: Referencing Path: %s\n",
754 fd_dev->fd_dev_name);
755 fd_dev->fbd_flags |= FBDF_HAS_PATH;
756 break;
757 case Opt_fd_dev_size:
758 arg_p = match_strdup(&args[0]);
759 if (!arg_p) {
760 ret = -ENOMEM;
761 break;
762 }
763 ret = kstrtoull(arg_p, 0, &fd_dev->fd_dev_size);
764 kfree(arg_p);
765 if (ret < 0) {
766 pr_err("kstrtoull() failed for"
767 " fd_dev_size=\n");
768 goto out;
769 }
770 pr_debug("FILEIO: Referencing Size: %llu"
771 " bytes\n", fd_dev->fd_dev_size);
772 fd_dev->fbd_flags |= FBDF_HAS_SIZE;
773 break;
774 case Opt_fd_buffered_io:
775 ret = match_int(args, &arg);
776 if (ret)
777 goto out;
778 if (arg != 1) {
779 pr_err("bogus fd_buffered_io=%d value\n", arg);
780 ret = -EINVAL;
781 goto out;
782 }
783
784 pr_debug("FILEIO: Using buffered I/O"
785 " operations for struct fd_dev\n");
786
787 fd_dev->fbd_flags |= FDBD_HAS_BUFFERED_IO_WCE;
788 break;
789 case Opt_fd_async_io:
790 ret = match_int(args, &arg);
791 if (ret)
792 goto out;
793 if (arg != 1) {
794 pr_err("bogus fd_async_io=%d value\n", arg);
795 ret = -EINVAL;
796 goto out;
797 }
798
799 pr_debug("FILEIO: Using async I/O"
800 " operations for struct fd_dev\n");
801
802 fd_dev->fbd_flags |= FDBD_HAS_ASYNC_IO;
803 break;
804 default:
805 break;
806 }
807 }
808
809out:
810 kfree(orig);
811 return (!ret) ? count : ret;
812}
813
814static ssize_t fd_show_configfs_dev_params(struct se_device *dev, char *b)
815{
816 struct fd_dev *fd_dev = FD_DEV(dev);
817 ssize_t bl = 0;
818
819 bl = sprintf(b + bl, "TCM FILEIO ID: %u", fd_dev->fd_dev_id);
820 bl += sprintf(b + bl, " File: %s Size: %llu Mode: %s Async: %d\n",
821 fd_dev->fd_dev_name, fd_dev->fd_dev_size,
822 (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) ?
823 "Buffered-WCE" : "O_DSYNC",
824 !!(fd_dev->fbd_flags & FDBD_HAS_ASYNC_IO));
825 return bl;
826}
827
828static sector_t fd_get_blocks(struct se_device *dev)
829{
830 struct fd_dev *fd_dev = FD_DEV(dev);
831 struct file *f = fd_dev->fd_file;
832 struct inode *i = f->f_mapping->host;
833 unsigned long long dev_size;
834 /*
835 * When using a file that references an underlying struct block_device,
836 * ensure dev_size is always based on the current inode size in order
837 * to handle underlying block_device resize operations.
838 */
839 if (S_ISBLK(i->i_mode))
840 dev_size = i_size_read(i);
841 else
842 dev_size = fd_dev->fd_dev_size;
843
844 return div_u64(dev_size - dev->dev_attrib.block_size,
845 dev->dev_attrib.block_size);
846}
847
848static int fd_init_prot(struct se_device *dev)
849{
850 struct fd_dev *fd_dev = FD_DEV(dev);
851 struct file *prot_file, *file = fd_dev->fd_file;
852 struct inode *inode;
853 int ret, flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
854 char buf[FD_MAX_DEV_PROT_NAME];
855
856 if (!file) {
857 pr_err("Unable to locate fd_dev->fd_file\n");
858 return -ENODEV;
859 }
860
861 inode = file->f_mapping->host;
862 if (S_ISBLK(inode->i_mode)) {
863 pr_err("FILEIO Protection emulation only supported on"
864 " !S_ISBLK\n");
865 return -ENOSYS;
866 }
867
868 if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE)
869 flags &= ~O_DSYNC;
870
871 snprintf(buf, FD_MAX_DEV_PROT_NAME, "%s.protection",
872 fd_dev->fd_dev_name);
873
874 prot_file = filp_open(buf, flags, 0600);
875 if (IS_ERR(prot_file)) {
876 pr_err("filp_open(%s) failed\n", buf);
877 ret = PTR_ERR(prot_file);
878 return ret;
879 }
880 fd_dev->fd_prot_file = prot_file;
881
882 return 0;
883}
884
885static int fd_format_prot(struct se_device *dev)
886{
887 unsigned char *buf;
888 int unit_size = FDBD_FORMAT_UNIT_SIZE * dev->dev_attrib.block_size;
889 int ret;
890
891 if (!dev->dev_attrib.pi_prot_type) {
892 pr_err("Unable to format_prot while pi_prot_type == 0\n");
893 return -ENODEV;
894 }
895
896 buf = vzalloc(unit_size);
897 if (!buf) {
898 pr_err("Unable to allocate FILEIO prot buf\n");
899 return -ENOMEM;
900 }
901
902 pr_debug("Using FILEIO prot_length: %llu\n",
903 (unsigned long long)(dev->transport->get_blocks(dev) + 1) *
904 dev->prot_length);
905
906 memset(buf, 0xff, unit_size);
907 ret = fd_do_prot_fill(dev, 0, dev->transport->get_blocks(dev) + 1,
908 buf, unit_size);
909 vfree(buf);
910 return ret;
911}
912
913static void fd_free_prot(struct se_device *dev)
914{
915 struct fd_dev *fd_dev = FD_DEV(dev);
916
917 if (!fd_dev->fd_prot_file)
918 return;
919
920 filp_close(fd_dev->fd_prot_file, NULL);
921 fd_dev->fd_prot_file = NULL;
922}
923
924static struct sbc_ops fd_sbc_ops = {
925 .execute_rw = fd_execute_rw,
926 .execute_sync_cache = fd_execute_sync_cache,
927 .execute_write_same = fd_execute_write_same,
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 const struct target_backend_ops fileio_ops = {
938 .name = "fileio",
939 .inquiry_prod = "FILEIO",
940 .inquiry_rev = FD_VERSION,
941 .owner = THIS_MODULE,
942 .attach_hba = fd_attach_hba,
943 .detach_hba = fd_detach_hba,
944 .alloc_device = fd_alloc_device,
945 .configure_device = fd_configure_device,
946 .destroy_device = fd_destroy_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 .tb_dev_attrib_attrs = sbc_attrib_attrs,
957};
958
959static int __init fileio_module_init(void)
960{
961 return transport_backend_register(&fileio_ops);
962}
963
964static void __exit fileio_module_exit(void)
965{
966 target_backend_unregister(&fileio_ops);
967}
968
969MODULE_DESCRIPTION("TCM FILEIO subsystem plugin");
970MODULE_AUTHOR("nab@Linux-iSCSI.org");
971MODULE_LICENSE("GPL");
972
973module_init(fileio_module_init);
974module_exit(fileio_module_exit);
975