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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 bvec_set_page(&aio_cmd->bvecs[i], sg_page(sg), sg->length,
285 sg->offset);
286 len += sg->length;
287 }
288
289 iov_iter_bvec(&iter, is_write, aio_cmd->bvecs, sgl_nents, len);
290
291 aio_cmd->cmd = cmd;
292 aio_cmd->len = len;
293 aio_cmd->iocb.ki_pos = cmd->t_task_lba * dev->dev_attrib.block_size;
294 aio_cmd->iocb.ki_filp = file;
295 aio_cmd->iocb.ki_complete = cmd_rw_aio_complete;
296 aio_cmd->iocb.ki_flags = IOCB_DIRECT;
297
298 if (is_write && (cmd->se_cmd_flags & SCF_FUA))
299 aio_cmd->iocb.ki_flags |= IOCB_DSYNC;
300
301 if (is_write)
302 ret = call_write_iter(file, &aio_cmd->iocb, &iter);
303 else
304 ret = call_read_iter(file, &aio_cmd->iocb, &iter);
305
306 if (ret != -EIOCBQUEUED)
307 cmd_rw_aio_complete(&aio_cmd->iocb, ret);
308
309 return 0;
310}
311
312static int fd_do_rw(struct se_cmd *cmd, struct file *fd,
313 u32 block_size, struct scatterlist *sgl,
314 u32 sgl_nents, u32 data_length, int is_write)
315{
316 struct scatterlist *sg;
317 struct iov_iter iter;
318 struct bio_vec *bvec;
319 ssize_t len = 0;
320 loff_t pos = (cmd->t_task_lba * block_size);
321 int ret = 0, i;
322
323 bvec = kcalloc(sgl_nents, sizeof(struct bio_vec), GFP_KERNEL);
324 if (!bvec) {
325 pr_err("Unable to allocate fd_do_readv iov[]\n");
326 return -ENOMEM;
327 }
328
329 for_each_sg(sgl, sg, sgl_nents, i) {
330 bvec_set_page(&bvec[i], sg_page(sg), sg->length, sg->offset);
331 len += sg->length;
332 }
333
334 iov_iter_bvec(&iter, is_write, bvec, sgl_nents, len);
335 if (is_write)
336 ret = vfs_iter_write(fd, &iter, &pos, 0);
337 else
338 ret = vfs_iter_read(fd, &iter, &pos, 0);
339
340 if (is_write) {
341 if (ret < 0 || ret != data_length) {
342 pr_err("%s() write returned %d\n", __func__, ret);
343 if (ret >= 0)
344 ret = -EINVAL;
345 }
346 } else {
347 /*
348 * Return zeros and GOOD status even if the READ did not return
349 * the expected virt_size for struct file w/o a backing struct
350 * block_device.
351 */
352 if (S_ISBLK(file_inode(fd)->i_mode)) {
353 if (ret < 0 || ret != data_length) {
354 pr_err("%s() returned %d, expecting %u for "
355 "S_ISBLK\n", __func__, ret,
356 data_length);
357 if (ret >= 0)
358 ret = -EINVAL;
359 }
360 } else {
361 if (ret < 0) {
362 pr_err("%s() returned %d for non S_ISBLK\n",
363 __func__, ret);
364 } else if (ret != data_length) {
365 /*
366 * Short read case:
367 * Probably some one truncate file under us.
368 * We must explicitly zero sg-pages to prevent
369 * expose uninizialized pages to userspace.
370 */
371 if (ret < data_length)
372 ret += iov_iter_zero(data_length - ret, &iter);
373 else
374 ret = -EINVAL;
375 }
376 }
377 }
378 kfree(bvec);
379 return ret;
380}
381
382static sense_reason_t
383fd_execute_sync_cache(struct se_cmd *cmd)
384{
385 struct se_device *dev = cmd->se_dev;
386 struct fd_dev *fd_dev = FD_DEV(dev);
387 int immed = (cmd->t_task_cdb[1] & 0x2);
388 loff_t start, end;
389 int ret;
390
391 /*
392 * If the Immediate bit is set, queue up the GOOD response
393 * for this SYNCHRONIZE_CACHE op
394 */
395 if (immed)
396 target_complete_cmd(cmd, SAM_STAT_GOOD);
397
398 /*
399 * Determine if we will be flushing the entire device.
400 */
401 if (cmd->t_task_lba == 0 && cmd->data_length == 0) {
402 start = 0;
403 end = LLONG_MAX;
404 } else {
405 start = cmd->t_task_lba * dev->dev_attrib.block_size;
406 if (cmd->data_length)
407 end = start + cmd->data_length - 1;
408 else
409 end = LLONG_MAX;
410 }
411
412 ret = vfs_fsync_range(fd_dev->fd_file, start, end, 1);
413 if (ret != 0)
414 pr_err("FILEIO: vfs_fsync_range() failed: %d\n", ret);
415
416 if (immed)
417 return 0;
418
419 if (ret)
420 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
421 else
422 target_complete_cmd(cmd, SAM_STAT_GOOD);
423
424 return 0;
425}
426
427static sense_reason_t
428fd_execute_write_same(struct se_cmd *cmd)
429{
430 struct se_device *se_dev = cmd->se_dev;
431 struct fd_dev *fd_dev = FD_DEV(se_dev);
432 loff_t pos = cmd->t_task_lba * se_dev->dev_attrib.block_size;
433 sector_t nolb = sbc_get_write_same_sectors(cmd);
434 struct iov_iter iter;
435 struct bio_vec *bvec;
436 unsigned int len = 0, i;
437 ssize_t ret;
438
439 if (cmd->prot_op) {
440 pr_err("WRITE_SAME: Protection information with FILEIO"
441 " backends not supported\n");
442 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
443 }
444
445 if (!cmd->t_data_nents)
446 return TCM_INVALID_CDB_FIELD;
447
448 if (cmd->t_data_nents > 1 ||
449 cmd->t_data_sg[0].length != cmd->se_dev->dev_attrib.block_size) {
450 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
451 " block_size: %u\n",
452 cmd->t_data_nents,
453 cmd->t_data_sg[0].length,
454 cmd->se_dev->dev_attrib.block_size);
455 return TCM_INVALID_CDB_FIELD;
456 }
457
458 bvec = kcalloc(nolb, sizeof(struct bio_vec), GFP_KERNEL);
459 if (!bvec)
460 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
461
462 for (i = 0; i < nolb; i++) {
463 bvec_set_page(&bvec[i], sg_page(&cmd->t_data_sg[0]),
464 cmd->t_data_sg[0].length,
465 cmd->t_data_sg[0].offset);
466 len += se_dev->dev_attrib.block_size;
467 }
468
469 iov_iter_bvec(&iter, ITER_SOURCE, bvec, nolb, len);
470 ret = vfs_iter_write(fd_dev->fd_file, &iter, &pos, 0);
471
472 kfree(bvec);
473 if (ret < 0 || ret != len) {
474 pr_err("vfs_iter_write() returned %zd for write same\n", ret);
475 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
476 }
477
478 target_complete_cmd(cmd, SAM_STAT_GOOD);
479 return 0;
480}
481
482static int
483fd_do_prot_fill(struct se_device *se_dev, sector_t lba, sector_t nolb,
484 void *buf, size_t bufsize)
485{
486 struct fd_dev *fd_dev = FD_DEV(se_dev);
487 struct file *prot_fd = fd_dev->fd_prot_file;
488 sector_t prot_length, prot;
489 loff_t pos = lba * se_dev->prot_length;
490
491 if (!prot_fd) {
492 pr_err("Unable to locate fd_dev->fd_prot_file\n");
493 return -ENODEV;
494 }
495
496 prot_length = nolb * se_dev->prot_length;
497
498 memset(buf, 0xff, bufsize);
499 for (prot = 0; prot < prot_length;) {
500 sector_t len = min_t(sector_t, bufsize, prot_length - prot);
501 ssize_t ret = kernel_write(prot_fd, buf, len, &pos);
502
503 if (ret != len) {
504 pr_err("vfs_write to prot file failed: %zd\n", ret);
505 return ret < 0 ? ret : -ENODEV;
506 }
507 prot += ret;
508 }
509
510 return 0;
511}
512
513static int
514fd_do_prot_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
515{
516 void *buf;
517 int rc;
518
519 buf = (void *)__get_free_page(GFP_KERNEL);
520 if (!buf) {
521 pr_err("Unable to allocate FILEIO prot buf\n");
522 return -ENOMEM;
523 }
524
525 rc = fd_do_prot_fill(cmd->se_dev, lba, nolb, buf, PAGE_SIZE);
526
527 free_page((unsigned long)buf);
528
529 return rc;
530}
531
532static sense_reason_t
533fd_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
534{
535 struct file *file = FD_DEV(cmd->se_dev)->fd_file;
536 struct inode *inode = file->f_mapping->host;
537 int ret;
538
539 if (!nolb) {
540 return 0;
541 }
542
543 if (cmd->se_dev->dev_attrib.pi_prot_type) {
544 ret = fd_do_prot_unmap(cmd, lba, nolb);
545 if (ret)
546 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
547 }
548
549 if (S_ISBLK(inode->i_mode)) {
550 /* The backend is block device, use discard */
551 struct block_device *bdev = I_BDEV(inode);
552 struct se_device *dev = cmd->se_dev;
553
554 ret = blkdev_issue_discard(bdev,
555 target_to_linux_sector(dev, lba),
556 target_to_linux_sector(dev, nolb),
557 GFP_KERNEL);
558 if (ret < 0) {
559 pr_warn("FILEIO: blkdev_issue_discard() failed: %d\n",
560 ret);
561 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
562 }
563 } else {
564 /* The backend is normal file, use fallocate */
565 struct se_device *se_dev = cmd->se_dev;
566 loff_t pos = lba * se_dev->dev_attrib.block_size;
567 unsigned int len = nolb * se_dev->dev_attrib.block_size;
568 int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
569
570 if (!file->f_op->fallocate)
571 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
572
573 ret = file->f_op->fallocate(file, mode, pos, len);
574 if (ret < 0) {
575 pr_warn("FILEIO: fallocate() failed: %d\n", ret);
576 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
577 }
578 }
579
580 return 0;
581}
582
583static sense_reason_t
584fd_execute_rw_buffered(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
585 enum dma_data_direction data_direction)
586{
587 struct se_device *dev = cmd->se_dev;
588 struct fd_dev *fd_dev = FD_DEV(dev);
589 struct file *file = fd_dev->fd_file;
590 struct file *pfile = fd_dev->fd_prot_file;
591 sense_reason_t rc;
592 int ret = 0;
593 /*
594 * Call vectorized fileio functions to map struct scatterlist
595 * physical memory addresses to struct iovec virtual memory.
596 */
597 if (data_direction == DMA_FROM_DEVICE) {
598 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
599 ret = fd_do_rw(cmd, pfile, dev->prot_length,
600 cmd->t_prot_sg, cmd->t_prot_nents,
601 cmd->prot_length, 0);
602 if (ret < 0)
603 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
604 }
605
606 ret = fd_do_rw(cmd, file, dev->dev_attrib.block_size,
607 sgl, sgl_nents, cmd->data_length, 0);
608
609 if (ret > 0 && cmd->prot_type && dev->dev_attrib.pi_prot_type &&
610 dev->dev_attrib.pi_prot_verify) {
611 u32 sectors = cmd->data_length >>
612 ilog2(dev->dev_attrib.block_size);
613
614 rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors,
615 0, cmd->t_prot_sg, 0);
616 if (rc)
617 return rc;
618 }
619 } else {
620 if (cmd->prot_type && dev->dev_attrib.pi_prot_type &&
621 dev->dev_attrib.pi_prot_verify) {
622 u32 sectors = cmd->data_length >>
623 ilog2(dev->dev_attrib.block_size);
624
625 rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors,
626 0, cmd->t_prot_sg, 0);
627 if (rc)
628 return rc;
629 }
630
631 ret = fd_do_rw(cmd, file, dev->dev_attrib.block_size,
632 sgl, sgl_nents, cmd->data_length, 1);
633 /*
634 * Perform implicit vfs_fsync_range() for fd_do_writev() ops
635 * for SCSI WRITEs with Forced Unit Access (FUA) set.
636 * Allow this to happen independent of WCE=0 setting.
637 */
638 if (ret > 0 && (cmd->se_cmd_flags & SCF_FUA)) {
639 loff_t start = cmd->t_task_lba *
640 dev->dev_attrib.block_size;
641 loff_t end;
642
643 if (cmd->data_length)
644 end = start + cmd->data_length - 1;
645 else
646 end = LLONG_MAX;
647
648 vfs_fsync_range(fd_dev->fd_file, start, end, 1);
649 }
650
651 if (ret > 0 && cmd->prot_type && dev->dev_attrib.pi_prot_type) {
652 ret = fd_do_rw(cmd, pfile, dev->prot_length,
653 cmd->t_prot_sg, cmd->t_prot_nents,
654 cmd->prot_length, 1);
655 if (ret < 0)
656 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
657 }
658 }
659
660 if (ret < 0)
661 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
662
663 target_complete_cmd(cmd, SAM_STAT_GOOD);
664 return 0;
665}
666
667static sense_reason_t
668fd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
669 enum dma_data_direction data_direction)
670{
671 struct se_device *dev = cmd->se_dev;
672 struct fd_dev *fd_dev = FD_DEV(dev);
673
674 /*
675 * We are currently limited by the number of iovecs (2048) per
676 * single vfs_[writev,readv] call.
677 */
678 if (cmd->data_length > FD_MAX_BYTES) {
679 pr_err("FILEIO: Not able to process I/O of %u bytes due to"
680 "FD_MAX_BYTES: %u iovec count limitation\n",
681 cmd->data_length, FD_MAX_BYTES);
682 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
683 }
684
685 if (fd_dev->fbd_flags & FDBD_HAS_ASYNC_IO)
686 return fd_execute_rw_aio(cmd, sgl, sgl_nents, data_direction);
687 return fd_execute_rw_buffered(cmd, sgl, sgl_nents, data_direction);
688}
689
690enum {
691 Opt_fd_dev_name, Opt_fd_dev_size, Opt_fd_buffered_io,
692 Opt_fd_async_io, Opt_err
693};
694
695static match_table_t tokens = {
696 {Opt_fd_dev_name, "fd_dev_name=%s"},
697 {Opt_fd_dev_size, "fd_dev_size=%s"},
698 {Opt_fd_buffered_io, "fd_buffered_io=%d"},
699 {Opt_fd_async_io, "fd_async_io=%d"},
700 {Opt_err, NULL}
701};
702
703static ssize_t fd_set_configfs_dev_params(struct se_device *dev,
704 const char *page, ssize_t count)
705{
706 struct fd_dev *fd_dev = FD_DEV(dev);
707 char *orig, *ptr, *arg_p, *opts;
708 substring_t args[MAX_OPT_ARGS];
709 int ret = 0, arg, token;
710
711 opts = kstrdup(page, GFP_KERNEL);
712 if (!opts)
713 return -ENOMEM;
714
715 orig = opts;
716
717 while ((ptr = strsep(&opts, ",\n")) != NULL) {
718 if (!*ptr)
719 continue;
720
721 token = match_token(ptr, tokens, args);
722 switch (token) {
723 case Opt_fd_dev_name:
724 if (match_strlcpy(fd_dev->fd_dev_name, &args[0],
725 FD_MAX_DEV_NAME) == 0) {
726 ret = -EINVAL;
727 break;
728 }
729 pr_debug("FILEIO: Referencing Path: %s\n",
730 fd_dev->fd_dev_name);
731 fd_dev->fbd_flags |= FBDF_HAS_PATH;
732 break;
733 case Opt_fd_dev_size:
734 arg_p = match_strdup(&args[0]);
735 if (!arg_p) {
736 ret = -ENOMEM;
737 break;
738 }
739 ret = kstrtoull(arg_p, 0, &fd_dev->fd_dev_size);
740 kfree(arg_p);
741 if (ret < 0) {
742 pr_err("kstrtoull() failed for"
743 " fd_dev_size=\n");
744 goto out;
745 }
746 pr_debug("FILEIO: Referencing Size: %llu"
747 " bytes\n", fd_dev->fd_dev_size);
748 fd_dev->fbd_flags |= FBDF_HAS_SIZE;
749 break;
750 case Opt_fd_buffered_io:
751 ret = match_int(args, &arg);
752 if (ret)
753 goto out;
754 if (arg != 1) {
755 pr_err("bogus fd_buffered_io=%d value\n", arg);
756 ret = -EINVAL;
757 goto out;
758 }
759
760 pr_debug("FILEIO: Using buffered I/O"
761 " operations for struct fd_dev\n");
762
763 fd_dev->fbd_flags |= FDBD_HAS_BUFFERED_IO_WCE;
764 break;
765 case Opt_fd_async_io:
766 ret = match_int(args, &arg);
767 if (ret)
768 goto out;
769 if (arg != 1) {
770 pr_err("bogus fd_async_io=%d value\n", arg);
771 ret = -EINVAL;
772 goto out;
773 }
774
775 pr_debug("FILEIO: Using async I/O"
776 " operations for struct fd_dev\n");
777
778 fd_dev->fbd_flags |= FDBD_HAS_ASYNC_IO;
779 break;
780 default:
781 break;
782 }
783 }
784
785out:
786 kfree(orig);
787 return (!ret) ? count : ret;
788}
789
790static ssize_t fd_show_configfs_dev_params(struct se_device *dev, char *b)
791{
792 struct fd_dev *fd_dev = FD_DEV(dev);
793 ssize_t bl = 0;
794
795 bl = sprintf(b + bl, "TCM FILEIO ID: %u", fd_dev->fd_dev_id);
796 bl += sprintf(b + bl, " File: %s Size: %llu Mode: %s Async: %d\n",
797 fd_dev->fd_dev_name, fd_dev->fd_dev_size,
798 (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) ?
799 "Buffered-WCE" : "O_DSYNC",
800 !!(fd_dev->fbd_flags & FDBD_HAS_ASYNC_IO));
801 return bl;
802}
803
804static sector_t fd_get_blocks(struct se_device *dev)
805{
806 struct fd_dev *fd_dev = FD_DEV(dev);
807 struct file *f = fd_dev->fd_file;
808 struct inode *i = f->f_mapping->host;
809 unsigned long long dev_size;
810 /*
811 * When using a file that references an underlying struct block_device,
812 * ensure dev_size is always based on the current inode size in order
813 * to handle underlying block_device resize operations.
814 */
815 if (S_ISBLK(i->i_mode))
816 dev_size = i_size_read(i);
817 else
818 dev_size = fd_dev->fd_dev_size;
819
820 return div_u64(dev_size - dev->dev_attrib.block_size,
821 dev->dev_attrib.block_size);
822}
823
824static int fd_init_prot(struct se_device *dev)
825{
826 struct fd_dev *fd_dev = FD_DEV(dev);
827 struct file *prot_file, *file = fd_dev->fd_file;
828 struct inode *inode;
829 int ret, flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
830 char buf[FD_MAX_DEV_PROT_NAME];
831
832 if (!file) {
833 pr_err("Unable to locate fd_dev->fd_file\n");
834 return -ENODEV;
835 }
836
837 inode = file->f_mapping->host;
838 if (S_ISBLK(inode->i_mode)) {
839 pr_err("FILEIO Protection emulation only supported on"
840 " !S_ISBLK\n");
841 return -ENOSYS;
842 }
843
844 if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE)
845 flags &= ~O_DSYNC;
846
847 snprintf(buf, FD_MAX_DEV_PROT_NAME, "%s.protection",
848 fd_dev->fd_dev_name);
849
850 prot_file = filp_open(buf, flags, 0600);
851 if (IS_ERR(prot_file)) {
852 pr_err("filp_open(%s) failed\n", buf);
853 ret = PTR_ERR(prot_file);
854 return ret;
855 }
856 fd_dev->fd_prot_file = prot_file;
857
858 return 0;
859}
860
861static int fd_format_prot(struct se_device *dev)
862{
863 unsigned char *buf;
864 int unit_size = FDBD_FORMAT_UNIT_SIZE * dev->dev_attrib.block_size;
865 int ret;
866
867 if (!dev->dev_attrib.pi_prot_type) {
868 pr_err("Unable to format_prot while pi_prot_type == 0\n");
869 return -ENODEV;
870 }
871
872 buf = vzalloc(unit_size);
873 if (!buf) {
874 pr_err("Unable to allocate FILEIO prot buf\n");
875 return -ENOMEM;
876 }
877
878 pr_debug("Using FILEIO prot_length: %llu\n",
879 (unsigned long long)(dev->transport->get_blocks(dev) + 1) *
880 dev->prot_length);
881
882 ret = fd_do_prot_fill(dev, 0, dev->transport->get_blocks(dev) + 1,
883 buf, unit_size);
884 vfree(buf);
885 return ret;
886}
887
888static void fd_free_prot(struct se_device *dev)
889{
890 struct fd_dev *fd_dev = FD_DEV(dev);
891
892 if (!fd_dev->fd_prot_file)
893 return;
894
895 filp_close(fd_dev->fd_prot_file, NULL);
896 fd_dev->fd_prot_file = NULL;
897}
898
899static struct exec_cmd_ops fd_exec_cmd_ops = {
900 .execute_rw = fd_execute_rw,
901 .execute_sync_cache = fd_execute_sync_cache,
902 .execute_write_same = fd_execute_write_same,
903 .execute_unmap = fd_execute_unmap,
904};
905
906static sense_reason_t
907fd_parse_cdb(struct se_cmd *cmd)
908{
909 return sbc_parse_cdb(cmd, &fd_exec_cmd_ops);
910}
911
912static const struct target_backend_ops fileio_ops = {
913 .name = "fileio",
914 .inquiry_prod = "FILEIO",
915 .inquiry_rev = FD_VERSION,
916 .owner = THIS_MODULE,
917 .attach_hba = fd_attach_hba,
918 .detach_hba = fd_detach_hba,
919 .alloc_device = fd_alloc_device,
920 .configure_device = fd_configure_device,
921 .destroy_device = fd_destroy_device,
922 .free_device = fd_free_device,
923 .configure_unmap = fd_configure_unmap,
924 .parse_cdb = fd_parse_cdb,
925 .set_configfs_dev_params = fd_set_configfs_dev_params,
926 .show_configfs_dev_params = fd_show_configfs_dev_params,
927 .get_device_type = sbc_get_device_type,
928 .get_blocks = fd_get_blocks,
929 .init_prot = fd_init_prot,
930 .format_prot = fd_format_prot,
931 .free_prot = fd_free_prot,
932 .tb_dev_attrib_attrs = sbc_attrib_attrs,
933};
934
935static int __init fileio_module_init(void)
936{
937 return transport_backend_register(&fileio_ops);
938}
939
940static void __exit fileio_module_exit(void)
941{
942 target_backend_unregister(&fileio_ops);
943}
944
945MODULE_DESCRIPTION("TCM FILEIO subsystem plugin");
946MODULE_AUTHOR("nab@Linux-iSCSI.org");
947MODULE_LICENSE("GPL");
948
949module_init(fileio_module_init);
950module_exit(fileio_module_exit);
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);