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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*******************************************************************************
3 * Filename: target_core_file.c
4 *
5 * This file contains the Storage Engine <-> FILEIO transport specific functions
6 *
7 * (c) Copyright 2005-2013 Datera, Inc.
8 *
9 * Nicholas A. Bellinger <nab@kernel.org>
10 *
11 ******************************************************************************/
12
13#include <linux/string.h>
14#include <linux/parser.h>
15#include <linux/timer.h>
16#include <linux/blkdev.h>
17#include <linux/slab.h>
18#include <linux/spinlock.h>
19#include <linux/module.h>
20#include <linux/vmalloc.h>
21#include <linux/falloc.h>
22#include <linux/uio.h>
23#include <linux/scatterlist.h>
24#include <scsi/scsi_proto.h>
25#include <asm/unaligned.h>
26
27#include <target/target_core_base.h>
28#include <target/target_core_backend.h>
29
30#include "target_core_file.h"
31
32static inline struct fd_dev *FD_DEV(struct se_device *dev)
33{
34 return container_of(dev, struct fd_dev, dev);
35}
36
37static int fd_attach_hba(struct se_hba *hba, u32 host_id)
38{
39 struct fd_host *fd_host;
40
41 fd_host = kzalloc(sizeof(struct fd_host), GFP_KERNEL);
42 if (!fd_host) {
43 pr_err("Unable to allocate memory for struct fd_host\n");
44 return -ENOMEM;
45 }
46
47 fd_host->fd_host_id = host_id;
48
49 hba->hba_ptr = fd_host;
50
51 pr_debug("CORE_HBA[%d] - TCM FILEIO HBA Driver %s on Generic"
52 " Target Core Stack %s\n", hba->hba_id, FD_VERSION,
53 TARGET_CORE_VERSION);
54 pr_debug("CORE_HBA[%d] - Attached FILEIO HBA: %u to Generic\n",
55 hba->hba_id, fd_host->fd_host_id);
56
57 return 0;
58}
59
60static void fd_detach_hba(struct se_hba *hba)
61{
62 struct fd_host *fd_host = hba->hba_ptr;
63
64 pr_debug("CORE_HBA[%d] - Detached FILEIO HBA: %u from Generic"
65 " Target Core\n", hba->hba_id, fd_host->fd_host_id);
66
67 kfree(fd_host);
68 hba->hba_ptr = NULL;
69}
70
71static struct se_device *fd_alloc_device(struct se_hba *hba, const char *name)
72{
73 struct fd_dev *fd_dev;
74 struct fd_host *fd_host = hba->hba_ptr;
75
76 fd_dev = kzalloc(sizeof(struct fd_dev), GFP_KERNEL);
77 if (!fd_dev) {
78 pr_err("Unable to allocate memory for struct fd_dev\n");
79 return NULL;
80 }
81
82 fd_dev->fd_host = fd_host;
83
84 pr_debug("FILEIO: Allocated fd_dev for %p\n", name);
85
86 return &fd_dev->dev;
87}
88
89static bool fd_configure_unmap(struct se_device *dev)
90{
91 struct file *file = FD_DEV(dev)->fd_file;
92 struct inode *inode = file->f_mapping->host;
93
94 if (S_ISBLK(inode->i_mode))
95 return target_configure_unmap_from_queue(&dev->dev_attrib,
96 I_BDEV(inode));
97
98 /* Limit UNMAP emulation to 8k Number of LBAs (NoLB) */
99 dev->dev_attrib.max_unmap_lba_count = 0x2000;
100 /* Currently hardcoded to 1 in Linux/SCSI code. */
101 dev->dev_attrib.max_unmap_block_desc_count = 1;
102 dev->dev_attrib.unmap_granularity = 1;
103 dev->dev_attrib.unmap_granularity_alignment = 0;
104 return true;
105}
106
107static int fd_configure_device(struct se_device *dev)
108{
109 struct fd_dev *fd_dev = FD_DEV(dev);
110 struct fd_host *fd_host = dev->se_hba->hba_ptr;
111 struct file *file;
112 struct inode *inode = NULL;
113 int flags, ret = -EINVAL;
114
115 if (!(fd_dev->fbd_flags & FBDF_HAS_PATH)) {
116 pr_err("Missing fd_dev_name=\n");
117 return -EINVAL;
118 }
119
120 /*
121 * Use O_DSYNC by default instead of O_SYNC to forgo syncing
122 * of pure timestamp updates.
123 */
124 flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
125
126 /*
127 * Optionally allow fd_buffered_io=1 to be enabled for people
128 * who want use the fs buffer cache as an WriteCache mechanism.
129 *
130 * This means that in event of a hard failure, there is a risk
131 * of silent data-loss if the SCSI client has *not* performed a
132 * forced unit access (FUA) write, or issued SYNCHRONIZE_CACHE
133 * to write-out the entire device cache.
134 */
135 if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
136 pr_debug("FILEIO: Disabling O_DSYNC, using buffered FILEIO\n");
137 flags &= ~O_DSYNC;
138 }
139
140 file = filp_open(fd_dev->fd_dev_name, flags, 0600);
141 if (IS_ERR(file)) {
142 pr_err("filp_open(%s) failed\n", fd_dev->fd_dev_name);
143 ret = PTR_ERR(file);
144 goto fail;
145 }
146 fd_dev->fd_file = file;
147 /*
148 * If using a block backend with this struct file, we extract
149 * fd_dev->fd_[block,dev]_size from struct block_device.
150 *
151 * Otherwise, we use the passed fd_size= from configfs
152 */
153 inode = file->f_mapping->host;
154 if (S_ISBLK(inode->i_mode)) {
155 struct block_device *bdev = I_BDEV(inode);
156 unsigned long long dev_size;
157
158 fd_dev->fd_block_size = bdev_logical_block_size(bdev);
159 /*
160 * Determine the number of bytes from i_size_read() minus
161 * one (1) logical sector from underlying struct block_device
162 */
163 dev_size = (i_size_read(file->f_mapping->host) -
164 fd_dev->fd_block_size);
165
166 pr_debug("FILEIO: Using size: %llu bytes from struct"
167 " block_device blocks: %llu logical_block_size: %d\n",
168 dev_size, div_u64(dev_size, fd_dev->fd_block_size),
169 fd_dev->fd_block_size);
170 /*
171 * Enable write same emulation for IBLOCK and use 0xFFFF as
172 * the smaller WRITE_SAME(10) only has a two-byte block count.
173 */
174 dev->dev_attrib.max_write_same_len = 0xFFFF;
175
176 if (bdev_nonrot(bdev))
177 dev->dev_attrib.is_nonrot = 1;
178 } else {
179 if (!(fd_dev->fbd_flags & FBDF_HAS_SIZE)) {
180 pr_err("FILEIO: Missing fd_dev_size="
181 " parameter, and no backing struct"
182 " block_device\n");
183 goto fail;
184 }
185
186 fd_dev->fd_block_size = FD_BLOCKSIZE;
187
188 /*
189 * Limit WRITE_SAME w/ UNMAP=0 emulation to 8k Number of LBAs (NoLB)
190 * based upon struct iovec limit for vfs_writev()
191 */
192 dev->dev_attrib.max_write_same_len = 0x1000;
193 }
194
195 dev->dev_attrib.hw_block_size = fd_dev->fd_block_size;
196 dev->dev_attrib.hw_max_sectors = FD_MAX_BYTES / fd_dev->fd_block_size;
197 dev->dev_attrib.hw_queue_depth = FD_MAX_DEVICE_QUEUE_DEPTH;
198
199 if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
200 pr_debug("FILEIO: Forcing setting of emulate_write_cache=1"
201 " with FDBD_HAS_BUFFERED_IO_WCE\n");
202 dev->dev_attrib.emulate_write_cache = 1;
203 }
204
205 fd_dev->fd_dev_id = fd_host->fd_host_dev_id_count++;
206 fd_dev->fd_queue_depth = dev->queue_depth;
207
208 pr_debug("CORE_FILE[%u] - Added TCM FILEIO Device ID: %u at %s,"
209 " %llu total bytes\n", fd_host->fd_host_id, fd_dev->fd_dev_id,
210 fd_dev->fd_dev_name, fd_dev->fd_dev_size);
211
212 return 0;
213fail:
214 if (fd_dev->fd_file) {
215 filp_close(fd_dev->fd_file, NULL);
216 fd_dev->fd_file = NULL;
217 }
218 return ret;
219}
220
221static void fd_dev_call_rcu(struct rcu_head *p)
222{
223 struct se_device *dev = container_of(p, struct se_device, rcu_head);
224 struct fd_dev *fd_dev = FD_DEV(dev);
225
226 kfree(fd_dev);
227}
228
229static void fd_free_device(struct se_device *dev)
230{
231 call_rcu(&dev->rcu_head, fd_dev_call_rcu);
232}
233
234static void fd_destroy_device(struct se_device *dev)
235{
236 struct fd_dev *fd_dev = FD_DEV(dev);
237
238 if (fd_dev->fd_file) {
239 filp_close(fd_dev->fd_file, NULL);
240 fd_dev->fd_file = NULL;
241 }
242}
243
244struct target_core_file_cmd {
245 unsigned long len;
246 struct se_cmd *cmd;
247 struct kiocb iocb;
248 struct bio_vec bvecs[];
249};
250
251static void cmd_rw_aio_complete(struct kiocb *iocb, long ret)
252{
253 struct target_core_file_cmd *cmd;
254
255 cmd = container_of(iocb, struct target_core_file_cmd, iocb);
256
257 if (ret != cmd->len)
258 target_complete_cmd(cmd->cmd, SAM_STAT_CHECK_CONDITION);
259 else
260 target_complete_cmd(cmd->cmd, SAM_STAT_GOOD);
261
262 kfree(cmd);
263}
264
265static sense_reason_t
266fd_execute_rw_aio(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
267 enum dma_data_direction data_direction)
268{
269 int is_write = !(data_direction == DMA_FROM_DEVICE);
270 struct se_device *dev = cmd->se_dev;
271 struct fd_dev *fd_dev = FD_DEV(dev);
272 struct file *file = fd_dev->fd_file;
273 struct target_core_file_cmd *aio_cmd;
274 struct iov_iter iter;
275 struct scatterlist *sg;
276 ssize_t len = 0;
277 int ret = 0, i;
278
279 aio_cmd = kmalloc(struct_size(aio_cmd, bvecs, sgl_nents), GFP_KERNEL);
280 if (!aio_cmd)
281 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
282
283 for_each_sg(sgl, sg, sgl_nents, i) {
284 aio_cmd->bvecs[i].bv_page = sg_page(sg);
285 aio_cmd->bvecs[i].bv_len = sg->length;
286 aio_cmd->bvecs[i].bv_offset = sg->offset;
287
288 len += sg->length;
289 }
290
291 iov_iter_bvec(&iter, is_write, aio_cmd->bvecs, sgl_nents, len);
292
293 aio_cmd->cmd = cmd;
294 aio_cmd->len = len;
295 aio_cmd->iocb.ki_pos = cmd->t_task_lba * dev->dev_attrib.block_size;
296 aio_cmd->iocb.ki_filp = file;
297 aio_cmd->iocb.ki_complete = cmd_rw_aio_complete;
298 aio_cmd->iocb.ki_flags = IOCB_DIRECT;
299
300 if (is_write && (cmd->se_cmd_flags & SCF_FUA))
301 aio_cmd->iocb.ki_flags |= IOCB_DSYNC;
302
303 if (is_write)
304 ret = call_write_iter(file, &aio_cmd->iocb, &iter);
305 else
306 ret = call_read_iter(file, &aio_cmd->iocb, &iter);
307
308 if (ret != -EIOCBQUEUED)
309 cmd_rw_aio_complete(&aio_cmd->iocb, ret);
310
311 return 0;
312}
313
314static int fd_do_rw(struct se_cmd *cmd, struct file *fd,
315 u32 block_size, struct scatterlist *sgl,
316 u32 sgl_nents, u32 data_length, int is_write)
317{
318 struct scatterlist *sg;
319 struct iov_iter iter;
320 struct bio_vec *bvec;
321 ssize_t len = 0;
322 loff_t pos = (cmd->t_task_lba * block_size);
323 int ret = 0, i;
324
325 bvec = kcalloc(sgl_nents, sizeof(struct bio_vec), GFP_KERNEL);
326 if (!bvec) {
327 pr_err("Unable to allocate fd_do_readv iov[]\n");
328 return -ENOMEM;
329 }
330
331 for_each_sg(sgl, sg, sgl_nents, i) {
332 bvec[i].bv_page = sg_page(sg);
333 bvec[i].bv_len = sg->length;
334 bvec[i].bv_offset = sg->offset;
335
336 len += sg->length;
337 }
338
339 iov_iter_bvec(&iter, is_write, bvec, sgl_nents, len);
340 if (is_write)
341 ret = vfs_iter_write(fd, &iter, &pos, 0);
342 else
343 ret = vfs_iter_read(fd, &iter, &pos, 0);
344
345 if (is_write) {
346 if (ret < 0 || ret != data_length) {
347 pr_err("%s() write returned %d\n", __func__, ret);
348 if (ret >= 0)
349 ret = -EINVAL;
350 }
351 } else {
352 /*
353 * Return zeros and GOOD status even if the READ did not return
354 * the expected virt_size for struct file w/o a backing struct
355 * block_device.
356 */
357 if (S_ISBLK(file_inode(fd)->i_mode)) {
358 if (ret < 0 || ret != data_length) {
359 pr_err("%s() returned %d, expecting %u for "
360 "S_ISBLK\n", __func__, ret,
361 data_length);
362 if (ret >= 0)
363 ret = -EINVAL;
364 }
365 } else {
366 if (ret < 0) {
367 pr_err("%s() returned %d for non S_ISBLK\n",
368 __func__, ret);
369 } else if (ret != data_length) {
370 /*
371 * Short read case:
372 * Probably some one truncate file under us.
373 * We must explicitly zero sg-pages to prevent
374 * expose uninizialized pages to userspace.
375 */
376 if (ret < data_length)
377 ret += iov_iter_zero(data_length - ret, &iter);
378 else
379 ret = -EINVAL;
380 }
381 }
382 }
383 kfree(bvec);
384 return ret;
385}
386
387static sense_reason_t
388fd_execute_sync_cache(struct se_cmd *cmd)
389{
390 struct se_device *dev = cmd->se_dev;
391 struct fd_dev *fd_dev = FD_DEV(dev);
392 int immed = (cmd->t_task_cdb[1] & 0x2);
393 loff_t start, end;
394 int ret;
395
396 /*
397 * If the Immediate bit is set, queue up the GOOD response
398 * for this SYNCHRONIZE_CACHE op
399 */
400 if (immed)
401 target_complete_cmd(cmd, SAM_STAT_GOOD);
402
403 /*
404 * Determine if we will be flushing the entire device.
405 */
406 if (cmd->t_task_lba == 0 && cmd->data_length == 0) {
407 start = 0;
408 end = LLONG_MAX;
409 } else {
410 start = cmd->t_task_lba * dev->dev_attrib.block_size;
411 if (cmd->data_length)
412 end = start + cmd->data_length - 1;
413 else
414 end = LLONG_MAX;
415 }
416
417 ret = vfs_fsync_range(fd_dev->fd_file, start, end, 1);
418 if (ret != 0)
419 pr_err("FILEIO: vfs_fsync_range() failed: %d\n", ret);
420
421 if (immed)
422 return 0;
423
424 if (ret)
425 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
426 else
427 target_complete_cmd(cmd, SAM_STAT_GOOD);
428
429 return 0;
430}
431
432static sense_reason_t
433fd_execute_write_same(struct se_cmd *cmd)
434{
435 struct se_device *se_dev = cmd->se_dev;
436 struct fd_dev *fd_dev = FD_DEV(se_dev);
437 loff_t pos = cmd->t_task_lba * se_dev->dev_attrib.block_size;
438 sector_t nolb = sbc_get_write_same_sectors(cmd);
439 struct iov_iter iter;
440 struct bio_vec *bvec;
441 unsigned int len = 0, i;
442 ssize_t ret;
443
444 if (cmd->prot_op) {
445 pr_err("WRITE_SAME: Protection information with FILEIO"
446 " backends not supported\n");
447 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
448 }
449
450 if (!cmd->t_data_nents)
451 return TCM_INVALID_CDB_FIELD;
452
453 if (cmd->t_data_nents > 1 ||
454 cmd->t_data_sg[0].length != cmd->se_dev->dev_attrib.block_size) {
455 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
456 " block_size: %u\n",
457 cmd->t_data_nents,
458 cmd->t_data_sg[0].length,
459 cmd->se_dev->dev_attrib.block_size);
460 return TCM_INVALID_CDB_FIELD;
461 }
462
463 bvec = kcalloc(nolb, sizeof(struct bio_vec), GFP_KERNEL);
464 if (!bvec)
465 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
466
467 for (i = 0; i < nolb; i++) {
468 bvec[i].bv_page = sg_page(&cmd->t_data_sg[0]);
469 bvec[i].bv_len = cmd->t_data_sg[0].length;
470 bvec[i].bv_offset = cmd->t_data_sg[0].offset;
471
472 len += se_dev->dev_attrib.block_size;
473 }
474
475 iov_iter_bvec(&iter, ITER_SOURCE, bvec, nolb, len);
476 ret = vfs_iter_write(fd_dev->fd_file, &iter, &pos, 0);
477
478 kfree(bvec);
479 if (ret < 0 || ret != len) {
480 pr_err("vfs_iter_write() returned %zd for write same\n", ret);
481 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
482 }
483
484 target_complete_cmd(cmd, SAM_STAT_GOOD);
485 return 0;
486}
487
488static int
489fd_do_prot_fill(struct se_device *se_dev, sector_t lba, sector_t nolb,
490 void *buf, size_t bufsize)
491{
492 struct fd_dev *fd_dev = FD_DEV(se_dev);
493 struct file *prot_fd = fd_dev->fd_prot_file;
494 sector_t prot_length, prot;
495 loff_t pos = lba * se_dev->prot_length;
496
497 if (!prot_fd) {
498 pr_err("Unable to locate fd_dev->fd_prot_file\n");
499 return -ENODEV;
500 }
501
502 prot_length = nolb * se_dev->prot_length;
503
504 memset(buf, 0xff, bufsize);
505 for (prot = 0; prot < prot_length;) {
506 sector_t len = min_t(sector_t, bufsize, prot_length - prot);
507 ssize_t ret = kernel_write(prot_fd, buf, len, &pos);
508
509 if (ret != len) {
510 pr_err("vfs_write to prot file failed: %zd\n", ret);
511 return ret < 0 ? ret : -ENODEV;
512 }
513 prot += ret;
514 }
515
516 return 0;
517}
518
519static int
520fd_do_prot_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
521{
522 void *buf;
523 int rc;
524
525 buf = (void *)__get_free_page(GFP_KERNEL);
526 if (!buf) {
527 pr_err("Unable to allocate FILEIO prot buf\n");
528 return -ENOMEM;
529 }
530
531 rc = fd_do_prot_fill(cmd->se_dev, lba, nolb, buf, PAGE_SIZE);
532
533 free_page((unsigned long)buf);
534
535 return rc;
536}
537
538static sense_reason_t
539fd_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
540{
541 struct file *file = FD_DEV(cmd->se_dev)->fd_file;
542 struct inode *inode = file->f_mapping->host;
543 int ret;
544
545 if (!nolb) {
546 return 0;
547 }
548
549 if (cmd->se_dev->dev_attrib.pi_prot_type) {
550 ret = fd_do_prot_unmap(cmd, lba, nolb);
551 if (ret)
552 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
553 }
554
555 if (S_ISBLK(inode->i_mode)) {
556 /* The backend is block device, use discard */
557 struct block_device *bdev = I_BDEV(inode);
558 struct se_device *dev = cmd->se_dev;
559
560 ret = blkdev_issue_discard(bdev,
561 target_to_linux_sector(dev, lba),
562 target_to_linux_sector(dev, nolb),
563 GFP_KERNEL);
564 if (ret < 0) {
565 pr_warn("FILEIO: blkdev_issue_discard() failed: %d\n",
566 ret);
567 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
568 }
569 } else {
570 /* The backend is normal file, use fallocate */
571 struct se_device *se_dev = cmd->se_dev;
572 loff_t pos = lba * se_dev->dev_attrib.block_size;
573 unsigned int len = nolb * se_dev->dev_attrib.block_size;
574 int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
575
576 if (!file->f_op->fallocate)
577 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
578
579 ret = file->f_op->fallocate(file, mode, pos, len);
580 if (ret < 0) {
581 pr_warn("FILEIO: fallocate() failed: %d\n", ret);
582 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
583 }
584 }
585
586 return 0;
587}
588
589static sense_reason_t
590fd_execute_rw_buffered(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
591 enum dma_data_direction data_direction)
592{
593 struct se_device *dev = cmd->se_dev;
594 struct fd_dev *fd_dev = FD_DEV(dev);
595 struct file *file = fd_dev->fd_file;
596 struct file *pfile = fd_dev->fd_prot_file;
597 sense_reason_t rc;
598 int ret = 0;
599 /*
600 * Call vectorized fileio functions to map struct scatterlist
601 * physical memory addresses to struct iovec virtual memory.
602 */
603 if (data_direction == DMA_FROM_DEVICE) {
604 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
605 ret = fd_do_rw(cmd, pfile, dev->prot_length,
606 cmd->t_prot_sg, cmd->t_prot_nents,
607 cmd->prot_length, 0);
608 if (ret < 0)
609 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
610 }
611
612 ret = fd_do_rw(cmd, file, dev->dev_attrib.block_size,
613 sgl, sgl_nents, cmd->data_length, 0);
614
615 if (ret > 0 && cmd->prot_type && dev->dev_attrib.pi_prot_type &&
616 dev->dev_attrib.pi_prot_verify) {
617 u32 sectors = cmd->data_length >>
618 ilog2(dev->dev_attrib.block_size);
619
620 rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors,
621 0, cmd->t_prot_sg, 0);
622 if (rc)
623 return rc;
624 }
625 } else {
626 if (cmd->prot_type && dev->dev_attrib.pi_prot_type &&
627 dev->dev_attrib.pi_prot_verify) {
628 u32 sectors = cmd->data_length >>
629 ilog2(dev->dev_attrib.block_size);
630
631 rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors,
632 0, cmd->t_prot_sg, 0);
633 if (rc)
634 return rc;
635 }
636
637 ret = fd_do_rw(cmd, file, dev->dev_attrib.block_size,
638 sgl, sgl_nents, cmd->data_length, 1);
639 /*
640 * Perform implicit vfs_fsync_range() for fd_do_writev() ops
641 * for SCSI WRITEs with Forced Unit Access (FUA) set.
642 * Allow this to happen independent of WCE=0 setting.
643 */
644 if (ret > 0 && (cmd->se_cmd_flags & SCF_FUA)) {
645 loff_t start = cmd->t_task_lba *
646 dev->dev_attrib.block_size;
647 loff_t end;
648
649 if (cmd->data_length)
650 end = start + cmd->data_length - 1;
651 else
652 end = LLONG_MAX;
653
654 vfs_fsync_range(fd_dev->fd_file, start, end, 1);
655 }
656
657 if (ret > 0 && cmd->prot_type && dev->dev_attrib.pi_prot_type) {
658 ret = fd_do_rw(cmd, pfile, dev->prot_length,
659 cmd->t_prot_sg, cmd->t_prot_nents,
660 cmd->prot_length, 1);
661 if (ret < 0)
662 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
663 }
664 }
665
666 if (ret < 0)
667 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
668
669 target_complete_cmd(cmd, SAM_STAT_GOOD);
670 return 0;
671}
672
673static sense_reason_t
674fd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
675 enum dma_data_direction data_direction)
676{
677 struct se_device *dev = cmd->se_dev;
678 struct fd_dev *fd_dev = FD_DEV(dev);
679
680 /*
681 * We are currently limited by the number of iovecs (2048) per
682 * single vfs_[writev,readv] call.
683 */
684 if (cmd->data_length > FD_MAX_BYTES) {
685 pr_err("FILEIO: Not able to process I/O of %u bytes due to"
686 "FD_MAX_BYTES: %u iovec count limitation\n",
687 cmd->data_length, FD_MAX_BYTES);
688 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
689 }
690
691 if (fd_dev->fbd_flags & FDBD_HAS_ASYNC_IO)
692 return fd_execute_rw_aio(cmd, sgl, sgl_nents, data_direction);
693 return fd_execute_rw_buffered(cmd, sgl, sgl_nents, data_direction);
694}
695
696enum {
697 Opt_fd_dev_name, Opt_fd_dev_size, Opt_fd_buffered_io,
698 Opt_fd_async_io, Opt_err
699};
700
701static match_table_t tokens = {
702 {Opt_fd_dev_name, "fd_dev_name=%s"},
703 {Opt_fd_dev_size, "fd_dev_size=%s"},
704 {Opt_fd_buffered_io, "fd_buffered_io=%d"},
705 {Opt_fd_async_io, "fd_async_io=%d"},
706 {Opt_err, NULL}
707};
708
709static ssize_t fd_set_configfs_dev_params(struct se_device *dev,
710 const char *page, ssize_t count)
711{
712 struct fd_dev *fd_dev = FD_DEV(dev);
713 char *orig, *ptr, *arg_p, *opts;
714 substring_t args[MAX_OPT_ARGS];
715 int ret = 0, arg, token;
716
717 opts = kstrdup(page, GFP_KERNEL);
718 if (!opts)
719 return -ENOMEM;
720
721 orig = opts;
722
723 while ((ptr = strsep(&opts, ",\n")) != NULL) {
724 if (!*ptr)
725 continue;
726
727 token = match_token(ptr, tokens, args);
728 switch (token) {
729 case Opt_fd_dev_name:
730 if (match_strlcpy(fd_dev->fd_dev_name, &args[0],
731 FD_MAX_DEV_NAME) == 0) {
732 ret = -EINVAL;
733 break;
734 }
735 pr_debug("FILEIO: Referencing Path: %s\n",
736 fd_dev->fd_dev_name);
737 fd_dev->fbd_flags |= FBDF_HAS_PATH;
738 break;
739 case Opt_fd_dev_size:
740 arg_p = match_strdup(&args[0]);
741 if (!arg_p) {
742 ret = -ENOMEM;
743 break;
744 }
745 ret = kstrtoull(arg_p, 0, &fd_dev->fd_dev_size);
746 kfree(arg_p);
747 if (ret < 0) {
748 pr_err("kstrtoull() failed for"
749 " fd_dev_size=\n");
750 goto out;
751 }
752 pr_debug("FILEIO: Referencing Size: %llu"
753 " bytes\n", fd_dev->fd_dev_size);
754 fd_dev->fbd_flags |= FBDF_HAS_SIZE;
755 break;
756 case Opt_fd_buffered_io:
757 ret = match_int(args, &arg);
758 if (ret)
759 goto out;
760 if (arg != 1) {
761 pr_err("bogus fd_buffered_io=%d value\n", arg);
762 ret = -EINVAL;
763 goto out;
764 }
765
766 pr_debug("FILEIO: Using buffered I/O"
767 " operations for struct fd_dev\n");
768
769 fd_dev->fbd_flags |= FDBD_HAS_BUFFERED_IO_WCE;
770 break;
771 case Opt_fd_async_io:
772 ret = match_int(args, &arg);
773 if (ret)
774 goto out;
775 if (arg != 1) {
776 pr_err("bogus fd_async_io=%d value\n", arg);
777 ret = -EINVAL;
778 goto out;
779 }
780
781 pr_debug("FILEIO: Using async I/O"
782 " operations for struct fd_dev\n");
783
784 fd_dev->fbd_flags |= FDBD_HAS_ASYNC_IO;
785 break;
786 default:
787 break;
788 }
789 }
790
791out:
792 kfree(orig);
793 return (!ret) ? count : ret;
794}
795
796static ssize_t fd_show_configfs_dev_params(struct se_device *dev, char *b)
797{
798 struct fd_dev *fd_dev = FD_DEV(dev);
799 ssize_t bl = 0;
800
801 bl = sprintf(b + bl, "TCM FILEIO ID: %u", fd_dev->fd_dev_id);
802 bl += sprintf(b + bl, " File: %s Size: %llu Mode: %s Async: %d\n",
803 fd_dev->fd_dev_name, fd_dev->fd_dev_size,
804 (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) ?
805 "Buffered-WCE" : "O_DSYNC",
806 !!(fd_dev->fbd_flags & FDBD_HAS_ASYNC_IO));
807 return bl;
808}
809
810static sector_t fd_get_blocks(struct se_device *dev)
811{
812 struct fd_dev *fd_dev = FD_DEV(dev);
813 struct file *f = fd_dev->fd_file;
814 struct inode *i = f->f_mapping->host;
815 unsigned long long dev_size;
816 /*
817 * When using a file that references an underlying struct block_device,
818 * ensure dev_size is always based on the current inode size in order
819 * to handle underlying block_device resize operations.
820 */
821 if (S_ISBLK(i->i_mode))
822 dev_size = i_size_read(i);
823 else
824 dev_size = fd_dev->fd_dev_size;
825
826 return div_u64(dev_size - dev->dev_attrib.block_size,
827 dev->dev_attrib.block_size);
828}
829
830static int fd_init_prot(struct se_device *dev)
831{
832 struct fd_dev *fd_dev = FD_DEV(dev);
833 struct file *prot_file, *file = fd_dev->fd_file;
834 struct inode *inode;
835 int ret, flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
836 char buf[FD_MAX_DEV_PROT_NAME];
837
838 if (!file) {
839 pr_err("Unable to locate fd_dev->fd_file\n");
840 return -ENODEV;
841 }
842
843 inode = file->f_mapping->host;
844 if (S_ISBLK(inode->i_mode)) {
845 pr_err("FILEIO Protection emulation only supported on"
846 " !S_ISBLK\n");
847 return -ENOSYS;
848 }
849
850 if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE)
851 flags &= ~O_DSYNC;
852
853 snprintf(buf, FD_MAX_DEV_PROT_NAME, "%s.protection",
854 fd_dev->fd_dev_name);
855
856 prot_file = filp_open(buf, flags, 0600);
857 if (IS_ERR(prot_file)) {
858 pr_err("filp_open(%s) failed\n", buf);
859 ret = PTR_ERR(prot_file);
860 return ret;
861 }
862 fd_dev->fd_prot_file = prot_file;
863
864 return 0;
865}
866
867static int fd_format_prot(struct se_device *dev)
868{
869 unsigned char *buf;
870 int unit_size = FDBD_FORMAT_UNIT_SIZE * dev->dev_attrib.block_size;
871 int ret;
872
873 if (!dev->dev_attrib.pi_prot_type) {
874 pr_err("Unable to format_prot while pi_prot_type == 0\n");
875 return -ENODEV;
876 }
877
878 buf = vzalloc(unit_size);
879 if (!buf) {
880 pr_err("Unable to allocate FILEIO prot buf\n");
881 return -ENOMEM;
882 }
883
884 pr_debug("Using FILEIO prot_length: %llu\n",
885 (unsigned long long)(dev->transport->get_blocks(dev) + 1) *
886 dev->prot_length);
887
888 ret = fd_do_prot_fill(dev, 0, dev->transport->get_blocks(dev) + 1,
889 buf, unit_size);
890 vfree(buf);
891 return ret;
892}
893
894static void fd_free_prot(struct se_device *dev)
895{
896 struct fd_dev *fd_dev = FD_DEV(dev);
897
898 if (!fd_dev->fd_prot_file)
899 return;
900
901 filp_close(fd_dev->fd_prot_file, NULL);
902 fd_dev->fd_prot_file = NULL;
903}
904
905static struct sbc_ops fd_sbc_ops = {
906 .execute_rw = fd_execute_rw,
907 .execute_sync_cache = fd_execute_sync_cache,
908 .execute_write_same = fd_execute_write_same,
909 .execute_unmap = fd_execute_unmap,
910};
911
912static sense_reason_t
913fd_parse_cdb(struct se_cmd *cmd)
914{
915 return sbc_parse_cdb(cmd, &fd_sbc_ops);
916}
917
918static const struct target_backend_ops fileio_ops = {
919 .name = "fileio",
920 .inquiry_prod = "FILEIO",
921 .inquiry_rev = FD_VERSION,
922 .owner = THIS_MODULE,
923 .attach_hba = fd_attach_hba,
924 .detach_hba = fd_detach_hba,
925 .alloc_device = fd_alloc_device,
926 .configure_device = fd_configure_device,
927 .destroy_device = fd_destroy_device,
928 .free_device = fd_free_device,
929 .configure_unmap = fd_configure_unmap,
930 .parse_cdb = fd_parse_cdb,
931 .set_configfs_dev_params = fd_set_configfs_dev_params,
932 .show_configfs_dev_params = fd_show_configfs_dev_params,
933 .get_device_type = sbc_get_device_type,
934 .get_blocks = fd_get_blocks,
935 .init_prot = fd_init_prot,
936 .format_prot = fd_format_prot,
937 .free_prot = fd_free_prot,
938 .tb_dev_attrib_attrs = sbc_attrib_attrs,
939};
940
941static int __init fileio_module_init(void)
942{
943 return transport_backend_register(&fileio_ops);
944}
945
946static void __exit fileio_module_exit(void)
947{
948 target_backend_unregister(&fileio_ops);
949}
950
951MODULE_DESCRIPTION("TCM FILEIO subsystem plugin");
952MODULE_AUTHOR("nab@Linux-iSCSI.org");
953MODULE_LICENSE("GPL");
954
955module_init(fileio_module_init);
956module_exit(fileio_module_exit);
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 struct fd_dev *fd_dev = FD_DEV(dev);
241
242 if (fd_dev->fd_file) {
243 filp_close(fd_dev->fd_file, NULL);
244 fd_dev->fd_file = NULL;
245 }
246 call_rcu(&dev->rcu_head, fd_dev_call_rcu);
247}
248
249static int fd_do_rw(struct se_cmd *cmd, struct file *fd,
250 u32 block_size, struct scatterlist *sgl,
251 u32 sgl_nents, u32 data_length, int is_write)
252{
253 struct scatterlist *sg;
254 struct iov_iter iter;
255 struct bio_vec *bvec;
256 ssize_t len = 0;
257 loff_t pos = (cmd->t_task_lba * block_size);
258 int ret = 0, i;
259
260 bvec = kcalloc(sgl_nents, sizeof(struct bio_vec), GFP_KERNEL);
261 if (!bvec) {
262 pr_err("Unable to allocate fd_do_readv iov[]\n");
263 return -ENOMEM;
264 }
265
266 for_each_sg(sgl, sg, sgl_nents, i) {
267 bvec[i].bv_page = sg_page(sg);
268 bvec[i].bv_len = sg->length;
269 bvec[i].bv_offset = sg->offset;
270
271 len += sg->length;
272 }
273
274 iov_iter_bvec(&iter, ITER_BVEC, bvec, sgl_nents, len);
275 if (is_write)
276 ret = vfs_iter_write(fd, &iter, &pos);
277 else
278 ret = vfs_iter_read(fd, &iter, &pos);
279
280 kfree(bvec);
281
282 if (is_write) {
283 if (ret < 0 || ret != data_length) {
284 pr_err("%s() write returned %d\n", __func__, ret);
285 return (ret < 0 ? ret : -EINVAL);
286 }
287 } else {
288 /*
289 * Return zeros and GOOD status even if the READ did not return
290 * the expected virt_size for struct file w/o a backing struct
291 * block_device.
292 */
293 if (S_ISBLK(file_inode(fd)->i_mode)) {
294 if (ret < 0 || ret != data_length) {
295 pr_err("%s() returned %d, expecting %u for "
296 "S_ISBLK\n", __func__, ret,
297 data_length);
298 return (ret < 0 ? ret : -EINVAL);
299 }
300 } else {
301 if (ret < 0) {
302 pr_err("%s() returned %d for non S_ISBLK\n",
303 __func__, ret);
304 return ret;
305 }
306 }
307 }
308 return 1;
309}
310
311static sense_reason_t
312fd_execute_sync_cache(struct se_cmd *cmd)
313{
314 struct se_device *dev = cmd->se_dev;
315 struct fd_dev *fd_dev = FD_DEV(dev);
316 int immed = (cmd->t_task_cdb[1] & 0x2);
317 loff_t start, end;
318 int ret;
319
320 /*
321 * If the Immediate bit is set, queue up the GOOD response
322 * for this SYNCHRONIZE_CACHE op
323 */
324 if (immed)
325 target_complete_cmd(cmd, SAM_STAT_GOOD);
326
327 /*
328 * Determine if we will be flushing the entire device.
329 */
330 if (cmd->t_task_lba == 0 && cmd->data_length == 0) {
331 start = 0;
332 end = LLONG_MAX;
333 } else {
334 start = cmd->t_task_lba * dev->dev_attrib.block_size;
335 if (cmd->data_length)
336 end = start + cmd->data_length - 1;
337 else
338 end = LLONG_MAX;
339 }
340
341 ret = vfs_fsync_range(fd_dev->fd_file, start, end, 1);
342 if (ret != 0)
343 pr_err("FILEIO: vfs_fsync_range() failed: %d\n", ret);
344
345 if (immed)
346 return 0;
347
348 if (ret)
349 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
350 else
351 target_complete_cmd(cmd, SAM_STAT_GOOD);
352
353 return 0;
354}
355
356static sense_reason_t
357fd_execute_write_same(struct se_cmd *cmd)
358{
359 struct se_device *se_dev = cmd->se_dev;
360 struct fd_dev *fd_dev = FD_DEV(se_dev);
361 loff_t pos = cmd->t_task_lba * se_dev->dev_attrib.block_size;
362 sector_t nolb = sbc_get_write_same_sectors(cmd);
363 struct iov_iter iter;
364 struct bio_vec *bvec;
365 unsigned int len = 0, i;
366 ssize_t ret;
367
368 if (!nolb) {
369 target_complete_cmd(cmd, SAM_STAT_GOOD);
370 return 0;
371 }
372 if (cmd->prot_op) {
373 pr_err("WRITE_SAME: Protection information with FILEIO"
374 " backends not supported\n");
375 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
376 }
377
378 if (cmd->t_data_nents > 1 ||
379 cmd->t_data_sg[0].length != cmd->se_dev->dev_attrib.block_size) {
380 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
381 " block_size: %u\n",
382 cmd->t_data_nents,
383 cmd->t_data_sg[0].length,
384 cmd->se_dev->dev_attrib.block_size);
385 return TCM_INVALID_CDB_FIELD;
386 }
387
388 bvec = kcalloc(nolb, sizeof(struct bio_vec), GFP_KERNEL);
389 if (!bvec)
390 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
391
392 for (i = 0; i < nolb; i++) {
393 bvec[i].bv_page = sg_page(&cmd->t_data_sg[0]);
394 bvec[i].bv_len = cmd->t_data_sg[0].length;
395 bvec[i].bv_offset = cmd->t_data_sg[0].offset;
396
397 len += se_dev->dev_attrib.block_size;
398 }
399
400 iov_iter_bvec(&iter, ITER_BVEC, bvec, nolb, len);
401 ret = vfs_iter_write(fd_dev->fd_file, &iter, &pos);
402
403 kfree(bvec);
404 if (ret < 0 || ret != len) {
405 pr_err("vfs_iter_write() returned %zd for write same\n", ret);
406 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
407 }
408
409 target_complete_cmd(cmd, SAM_STAT_GOOD);
410 return 0;
411}
412
413static int
414fd_do_prot_fill(struct se_device *se_dev, sector_t lba, sector_t nolb,
415 void *buf, size_t bufsize)
416{
417 struct fd_dev *fd_dev = FD_DEV(se_dev);
418 struct file *prot_fd = fd_dev->fd_prot_file;
419 sector_t prot_length, prot;
420 loff_t pos = lba * se_dev->prot_length;
421
422 if (!prot_fd) {
423 pr_err("Unable to locate fd_dev->fd_prot_file\n");
424 return -ENODEV;
425 }
426
427 prot_length = nolb * se_dev->prot_length;
428
429 for (prot = 0; prot < prot_length;) {
430 sector_t len = min_t(sector_t, bufsize, prot_length - prot);
431 ssize_t ret = kernel_write(prot_fd, buf, len, pos + prot);
432
433 if (ret != len) {
434 pr_err("vfs_write to prot file failed: %zd\n", ret);
435 return ret < 0 ? ret : -ENODEV;
436 }
437 prot += ret;
438 }
439
440 return 0;
441}
442
443static int
444fd_do_prot_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
445{
446 void *buf;
447 int rc;
448
449 buf = (void *)__get_free_page(GFP_KERNEL);
450 if (!buf) {
451 pr_err("Unable to allocate FILEIO prot buf\n");
452 return -ENOMEM;
453 }
454 memset(buf, 0xff, PAGE_SIZE);
455
456 rc = fd_do_prot_fill(cmd->se_dev, lba, nolb, buf, PAGE_SIZE);
457
458 free_page((unsigned long)buf);
459
460 return rc;
461}
462
463static sense_reason_t
464fd_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
465{
466 struct file *file = FD_DEV(cmd->se_dev)->fd_file;
467 struct inode *inode = file->f_mapping->host;
468 int ret;
469
470 if (cmd->se_dev->dev_attrib.pi_prot_type) {
471 ret = fd_do_prot_unmap(cmd, lba, nolb);
472 if (ret)
473 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
474 }
475
476 if (S_ISBLK(inode->i_mode)) {
477 /* The backend is block device, use discard */
478 struct block_device *bdev = inode->i_bdev;
479 struct se_device *dev = cmd->se_dev;
480
481 ret = blkdev_issue_discard(bdev,
482 target_to_linux_sector(dev, lba),
483 target_to_linux_sector(dev, nolb),
484 GFP_KERNEL, 0);
485 if (ret < 0) {
486 pr_warn("FILEIO: blkdev_issue_discard() failed: %d\n",
487 ret);
488 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
489 }
490 } else {
491 /* The backend is normal file, use fallocate */
492 struct se_device *se_dev = cmd->se_dev;
493 loff_t pos = lba * se_dev->dev_attrib.block_size;
494 unsigned int len = nolb * se_dev->dev_attrib.block_size;
495 int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
496
497 if (!file->f_op->fallocate)
498 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
499
500 ret = file->f_op->fallocate(file, mode, pos, len);
501 if (ret < 0) {
502 pr_warn("FILEIO: fallocate() failed: %d\n", ret);
503 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
504 }
505 }
506
507 return 0;
508}
509
510static sense_reason_t
511fd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
512 enum dma_data_direction data_direction)
513{
514 struct se_device *dev = cmd->se_dev;
515 struct fd_dev *fd_dev = FD_DEV(dev);
516 struct file *file = fd_dev->fd_file;
517 struct file *pfile = fd_dev->fd_prot_file;
518 sense_reason_t rc;
519 int ret = 0;
520 /*
521 * We are currently limited by the number of iovecs (2048) per
522 * single vfs_[writev,readv] call.
523 */
524 if (cmd->data_length > FD_MAX_BYTES) {
525 pr_err("FILEIO: Not able to process I/O of %u bytes due to"
526 "FD_MAX_BYTES: %u iovec count limitation\n",
527 cmd->data_length, FD_MAX_BYTES);
528 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
529 }
530 /*
531 * Call vectorized fileio functions to map struct scatterlist
532 * physical memory addresses to struct iovec virtual memory.
533 */
534 if (data_direction == DMA_FROM_DEVICE) {
535 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
536 ret = fd_do_rw(cmd, pfile, dev->prot_length,
537 cmd->t_prot_sg, cmd->t_prot_nents,
538 cmd->prot_length, 0);
539 if (ret < 0)
540 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
541 }
542
543 ret = fd_do_rw(cmd, file, dev->dev_attrib.block_size,
544 sgl, sgl_nents, cmd->data_length, 0);
545
546 if (ret > 0 && cmd->prot_type && dev->dev_attrib.pi_prot_type) {
547 u32 sectors = cmd->data_length >>
548 ilog2(dev->dev_attrib.block_size);
549
550 rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors,
551 0, cmd->t_prot_sg, 0);
552 if (rc)
553 return rc;
554 }
555 } else {
556 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
557 u32 sectors = cmd->data_length >>
558 ilog2(dev->dev_attrib.block_size);
559
560 rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors,
561 0, cmd->t_prot_sg, 0);
562 if (rc)
563 return rc;
564 }
565
566 ret = fd_do_rw(cmd, file, dev->dev_attrib.block_size,
567 sgl, sgl_nents, cmd->data_length, 1);
568 /*
569 * Perform implicit vfs_fsync_range() for fd_do_writev() ops
570 * for SCSI WRITEs with Forced Unit Access (FUA) set.
571 * Allow this to happen independent of WCE=0 setting.
572 */
573 if (ret > 0 && (cmd->se_cmd_flags & SCF_FUA)) {
574 loff_t start = cmd->t_task_lba *
575 dev->dev_attrib.block_size;
576 loff_t end;
577
578 if (cmd->data_length)
579 end = start + cmd->data_length - 1;
580 else
581 end = LLONG_MAX;
582
583 vfs_fsync_range(fd_dev->fd_file, start, end, 1);
584 }
585
586 if (ret > 0 && cmd->prot_type && dev->dev_attrib.pi_prot_type) {
587 ret = fd_do_rw(cmd, pfile, dev->prot_length,
588 cmd->t_prot_sg, cmd->t_prot_nents,
589 cmd->prot_length, 1);
590 if (ret < 0)
591 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
592 }
593 }
594
595 if (ret < 0)
596 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
597
598 if (ret)
599 target_complete_cmd(cmd, SAM_STAT_GOOD);
600 return 0;
601}
602
603enum {
604 Opt_fd_dev_name, Opt_fd_dev_size, Opt_fd_buffered_io, Opt_err
605};
606
607static match_table_t tokens = {
608 {Opt_fd_dev_name, "fd_dev_name=%s"},
609 {Opt_fd_dev_size, "fd_dev_size=%s"},
610 {Opt_fd_buffered_io, "fd_buffered_io=%d"},
611 {Opt_err, NULL}
612};
613
614static ssize_t fd_set_configfs_dev_params(struct se_device *dev,
615 const char *page, ssize_t count)
616{
617 struct fd_dev *fd_dev = FD_DEV(dev);
618 char *orig, *ptr, *arg_p, *opts;
619 substring_t args[MAX_OPT_ARGS];
620 int ret = 0, arg, token;
621
622 opts = kstrdup(page, GFP_KERNEL);
623 if (!opts)
624 return -ENOMEM;
625
626 orig = opts;
627
628 while ((ptr = strsep(&opts, ",\n")) != NULL) {
629 if (!*ptr)
630 continue;
631
632 token = match_token(ptr, tokens, args);
633 switch (token) {
634 case Opt_fd_dev_name:
635 if (match_strlcpy(fd_dev->fd_dev_name, &args[0],
636 FD_MAX_DEV_NAME) == 0) {
637 ret = -EINVAL;
638 break;
639 }
640 pr_debug("FILEIO: Referencing Path: %s\n",
641 fd_dev->fd_dev_name);
642 fd_dev->fbd_flags |= FBDF_HAS_PATH;
643 break;
644 case Opt_fd_dev_size:
645 arg_p = match_strdup(&args[0]);
646 if (!arg_p) {
647 ret = -ENOMEM;
648 break;
649 }
650 ret = kstrtoull(arg_p, 0, &fd_dev->fd_dev_size);
651 kfree(arg_p);
652 if (ret < 0) {
653 pr_err("kstrtoull() failed for"
654 " fd_dev_size=\n");
655 goto out;
656 }
657 pr_debug("FILEIO: Referencing Size: %llu"
658 " bytes\n", fd_dev->fd_dev_size);
659 fd_dev->fbd_flags |= FBDF_HAS_SIZE;
660 break;
661 case Opt_fd_buffered_io:
662 ret = match_int(args, &arg);
663 if (ret)
664 goto out;
665 if (arg != 1) {
666 pr_err("bogus fd_buffered_io=%d value\n", arg);
667 ret = -EINVAL;
668 goto out;
669 }
670
671 pr_debug("FILEIO: Using buffered I/O"
672 " operations for struct fd_dev\n");
673
674 fd_dev->fbd_flags |= FDBD_HAS_BUFFERED_IO_WCE;
675 break;
676 default:
677 break;
678 }
679 }
680
681out:
682 kfree(orig);
683 return (!ret) ? count : ret;
684}
685
686static ssize_t fd_show_configfs_dev_params(struct se_device *dev, char *b)
687{
688 struct fd_dev *fd_dev = FD_DEV(dev);
689 ssize_t bl = 0;
690
691 bl = sprintf(b + bl, "TCM FILEIO ID: %u", fd_dev->fd_dev_id);
692 bl += sprintf(b + bl, " File: %s Size: %llu Mode: %s\n",
693 fd_dev->fd_dev_name, fd_dev->fd_dev_size,
694 (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) ?
695 "Buffered-WCE" : "O_DSYNC");
696 return bl;
697}
698
699static sector_t fd_get_blocks(struct se_device *dev)
700{
701 struct fd_dev *fd_dev = FD_DEV(dev);
702 struct file *f = fd_dev->fd_file;
703 struct inode *i = f->f_mapping->host;
704 unsigned long long dev_size;
705 /*
706 * When using a file that references an underlying struct block_device,
707 * ensure dev_size is always based on the current inode size in order
708 * to handle underlying block_device resize operations.
709 */
710 if (S_ISBLK(i->i_mode))
711 dev_size = i_size_read(i);
712 else
713 dev_size = fd_dev->fd_dev_size;
714
715 return div_u64(dev_size - dev->dev_attrib.block_size,
716 dev->dev_attrib.block_size);
717}
718
719static int fd_init_prot(struct se_device *dev)
720{
721 struct fd_dev *fd_dev = FD_DEV(dev);
722 struct file *prot_file, *file = fd_dev->fd_file;
723 struct inode *inode;
724 int ret, flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
725 char buf[FD_MAX_DEV_PROT_NAME];
726
727 if (!file) {
728 pr_err("Unable to locate fd_dev->fd_file\n");
729 return -ENODEV;
730 }
731
732 inode = file->f_mapping->host;
733 if (S_ISBLK(inode->i_mode)) {
734 pr_err("FILEIO Protection emulation only supported on"
735 " !S_ISBLK\n");
736 return -ENOSYS;
737 }
738
739 if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE)
740 flags &= ~O_DSYNC;
741
742 snprintf(buf, FD_MAX_DEV_PROT_NAME, "%s.protection",
743 fd_dev->fd_dev_name);
744
745 prot_file = filp_open(buf, flags, 0600);
746 if (IS_ERR(prot_file)) {
747 pr_err("filp_open(%s) failed\n", buf);
748 ret = PTR_ERR(prot_file);
749 return ret;
750 }
751 fd_dev->fd_prot_file = prot_file;
752
753 return 0;
754}
755
756static int fd_format_prot(struct se_device *dev)
757{
758 unsigned char *buf;
759 int unit_size = FDBD_FORMAT_UNIT_SIZE * dev->dev_attrib.block_size;
760 int ret;
761
762 if (!dev->dev_attrib.pi_prot_type) {
763 pr_err("Unable to format_prot while pi_prot_type == 0\n");
764 return -ENODEV;
765 }
766
767 buf = vzalloc(unit_size);
768 if (!buf) {
769 pr_err("Unable to allocate FILEIO prot buf\n");
770 return -ENOMEM;
771 }
772
773 pr_debug("Using FILEIO prot_length: %llu\n",
774 (unsigned long long)(dev->transport->get_blocks(dev) + 1) *
775 dev->prot_length);
776
777 memset(buf, 0xff, unit_size);
778 ret = fd_do_prot_fill(dev, 0, dev->transport->get_blocks(dev) + 1,
779 buf, unit_size);
780 vfree(buf);
781 return ret;
782}
783
784static void fd_free_prot(struct se_device *dev)
785{
786 struct fd_dev *fd_dev = FD_DEV(dev);
787
788 if (!fd_dev->fd_prot_file)
789 return;
790
791 filp_close(fd_dev->fd_prot_file, NULL);
792 fd_dev->fd_prot_file = NULL;
793}
794
795static struct sbc_ops fd_sbc_ops = {
796 .execute_rw = fd_execute_rw,
797 .execute_sync_cache = fd_execute_sync_cache,
798 .execute_write_same = fd_execute_write_same,
799 .execute_unmap = fd_execute_unmap,
800};
801
802static sense_reason_t
803fd_parse_cdb(struct se_cmd *cmd)
804{
805 return sbc_parse_cdb(cmd, &fd_sbc_ops);
806}
807
808static const struct target_backend_ops fileio_ops = {
809 .name = "fileio",
810 .inquiry_prod = "FILEIO",
811 .inquiry_rev = FD_VERSION,
812 .owner = THIS_MODULE,
813 .attach_hba = fd_attach_hba,
814 .detach_hba = fd_detach_hba,
815 .alloc_device = fd_alloc_device,
816 .configure_device = fd_configure_device,
817 .free_device = fd_free_device,
818 .parse_cdb = fd_parse_cdb,
819 .set_configfs_dev_params = fd_set_configfs_dev_params,
820 .show_configfs_dev_params = fd_show_configfs_dev_params,
821 .get_device_type = sbc_get_device_type,
822 .get_blocks = fd_get_blocks,
823 .init_prot = fd_init_prot,
824 .format_prot = fd_format_prot,
825 .free_prot = fd_free_prot,
826 .tb_dev_attrib_attrs = sbc_attrib_attrs,
827};
828
829static int __init fileio_module_init(void)
830{
831 return transport_backend_register(&fileio_ops);
832}
833
834static void __exit fileio_module_exit(void)
835{
836 target_backend_unregister(&fileio_ops);
837}
838
839MODULE_DESCRIPTION("TCM FILEIO subsystem plugin");
840MODULE_AUTHOR("nab@Linux-iSCSI.org");
841MODULE_LICENSE("GPL");
842
843module_init(fileio_module_init);
844module_exit(fileio_module_exit);