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x86/kexec: Make kexec (mostly) work in 5-level paging mode
[linux-2.6/btrfs-unstable.git] / drivers / target / target_core_file.c
blob9b2c0c773022c0013de3bbce849ca78af117b2c5
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
44 static inline struct fd_dev *FD_DEV(struct se_device *dev)
45 {
46 return container_of(dev, struct fd_dev, dev);
47 }
48
49 static 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
72 static 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
83 static 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
101 static 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;
222 fail:
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
230 static 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
238 static void fd_free_device(struct se_device *dev)
239 {
240 call_rcu(&dev->rcu_head, fd_dev_call_rcu);
241 }
242
243 static void fd_destroy_device(struct se_device *dev)
244 {
245 struct fd_dev *fd_dev = FD_DEV(dev);
246
247 if (fd_dev->fd_file) {
248 filp_close(fd_dev->fd_file, NULL);
249 fd_dev->fd_file = NULL;
250 }
251 }
252
253 static int fd_do_rw(struct se_cmd *cmd, struct file *fd,
254 u32 block_size, struct scatterlist *sgl,
255 u32 sgl_nents, u32 data_length, int is_write)
256 {
257 struct scatterlist *sg;
258 struct iov_iter iter;
259 struct bio_vec *bvec;
260 ssize_t len = 0;
261 loff_t pos = (cmd->t_task_lba * block_size);
262 int ret = 0, i;
263
264 bvec = kcalloc(sgl_nents, sizeof(struct bio_vec), GFP_KERNEL);
265 if (!bvec) {
266 pr_err("Unable to allocate fd_do_readv iov[]\n");
267 return -ENOMEM;
268 }
269
270 for_each_sg(sgl, sg, sgl_nents, i) {
271 bvec[i].bv_page = sg_page(sg);
272 bvec[i].bv_len = sg->length;
273 bvec[i].bv_offset = sg->offset;
274
275 len += sg->length;
276 }
277
278 iov_iter_bvec(&iter, ITER_BVEC, bvec, sgl_nents, len);
279 if (is_write)
280 ret = vfs_iter_write(fd, &iter, &pos, 0);
281 else
282 ret = vfs_iter_read(fd, &iter, &pos, 0);
283
284 if (is_write) {
285 if (ret < 0 || ret != data_length) {
286 pr_err("%s() write returned %d\n", __func__, ret);
287 if (ret >= 0)
288 ret = -EINVAL;
289 }
290 } else {
291 /*
292 * Return zeros and GOOD status even if the READ did not return
293 * the expected virt_size for struct file w/o a backing struct
294 * block_device.
295 */
296 if (S_ISBLK(file_inode(fd)->i_mode)) {
297 if (ret < 0 || ret != data_length) {
298 pr_err("%s() returned %d, expecting %u for "
299 "S_ISBLK\n", __func__, ret,
300 data_length);
301 if (ret >= 0)
302 ret = -EINVAL;
303 }
304 } else {
305 if (ret < 0) {
306 pr_err("%s() returned %d for non S_ISBLK\n",
307 __func__, ret);
308 } else if (ret != data_length) {
309 /*
310 * Short read case:
311 * Probably some one truncate file under us.
312 * We must explicitly zero sg-pages to prevent
313 * expose uninizialized pages to userspace.
314 */
315 if (ret < data_length)
316 ret += iov_iter_zero(data_length - ret, &iter);
317 else
318 ret = -EINVAL;
319 }
320 }
321 }
322 kfree(bvec);
323 return ret;
324 }
325
326 static sense_reason_t
327 fd_execute_sync_cache(struct se_cmd *cmd)
328 {
329 struct se_device *dev = cmd->se_dev;
330 struct fd_dev *fd_dev = FD_DEV(dev);
331 int immed = (cmd->t_task_cdb[1] & 0x2);
332 loff_t start, end;
333 int ret;
334
335 /*
336 * If the Immediate bit is set, queue up the GOOD response
337 * for this SYNCHRONIZE_CACHE op
338 */
339 if (immed)
340 target_complete_cmd(cmd, SAM_STAT_GOOD);
341
342 /*
343 * Determine if we will be flushing the entire device.
344 */
345 if (cmd->t_task_lba == 0 && cmd->data_length == 0) {
346 start = 0;
347 end = LLONG_MAX;
348 } else {
349 start = cmd->t_task_lba * dev->dev_attrib.block_size;
350 if (cmd->data_length)
351 end = start + cmd->data_length - 1;
352 else
353 end = LLONG_MAX;
354 }
355
356 ret = vfs_fsync_range(fd_dev->fd_file, start, end, 1);
357 if (ret != 0)
358 pr_err("FILEIO: vfs_fsync_range() failed: %d\n", ret);
359
360 if (immed)
361 return 0;
362
363 if (ret)
364 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
365 else
366 target_complete_cmd(cmd, SAM_STAT_GOOD);
367
368 return 0;
369 }
370
371 static sense_reason_t
372 fd_execute_write_same(struct se_cmd *cmd)
373 {
374 struct se_device *se_dev = cmd->se_dev;
375 struct fd_dev *fd_dev = FD_DEV(se_dev);
376 loff_t pos = cmd->t_task_lba * se_dev->dev_attrib.block_size;
377 sector_t nolb = sbc_get_write_same_sectors(cmd);
378 struct iov_iter iter;
379 struct bio_vec *bvec;
380 unsigned int len = 0, i;
381 ssize_t ret;
382
383 if (!nolb) {
384 target_complete_cmd(cmd, SAM_STAT_GOOD);
385 return 0;
386 }
387 if (cmd->prot_op) {
388 pr_err("WRITE_SAME: Protection information with FILEIO"
389 " backends not supported\n");
390 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
391 }
392
393 if (cmd->t_data_nents > 1 ||
394 cmd->t_data_sg[0].length != cmd->se_dev->dev_attrib.block_size) {
395 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
396 " block_size: %u\n",
397 cmd->t_data_nents,
398 cmd->t_data_sg[0].length,
399 cmd->se_dev->dev_attrib.block_size);
400 return TCM_INVALID_CDB_FIELD;
401 }
402
403 bvec = kcalloc(nolb, sizeof(struct bio_vec), GFP_KERNEL);
404 if (!bvec)
405 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
406
407 for (i = 0; i < nolb; i++) {
408 bvec[i].bv_page = sg_page(&cmd->t_data_sg[0]);
409 bvec[i].bv_len = cmd->t_data_sg[0].length;
410 bvec[i].bv_offset = cmd->t_data_sg[0].offset;
411
412 len += se_dev->dev_attrib.block_size;
413 }
414
415 iov_iter_bvec(&iter, ITER_BVEC, bvec, nolb, len);
416 ret = vfs_iter_write(fd_dev->fd_file, &iter, &pos, 0);
417
418 kfree(bvec);
419 if (ret < 0 || ret != len) {
420 pr_err("vfs_iter_write() returned %zd for write same\n", ret);
421 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
422 }
423
424 target_complete_cmd(cmd, SAM_STAT_GOOD);
425 return 0;
426 }
427
428 static int
429 fd_do_prot_fill(struct se_device *se_dev, sector_t lba, sector_t nolb,
430 void *buf, size_t bufsize)
431 {
432 struct fd_dev *fd_dev = FD_DEV(se_dev);
433 struct file *prot_fd = fd_dev->fd_prot_file;
434 sector_t prot_length, prot;
435 loff_t pos = lba * se_dev->prot_length;
436
437 if (!prot_fd) {
438 pr_err("Unable to locate fd_dev->fd_prot_file\n");
439 return -ENODEV;
440 }
441
442 prot_length = nolb * se_dev->prot_length;
443
444 for (prot = 0; prot < prot_length;) {
445 sector_t len = min_t(sector_t, bufsize, prot_length - prot);
446 ssize_t ret = kernel_write(prot_fd, buf, len, &pos);
447
448 if (ret != len) {
449 pr_err("vfs_write to prot file failed: %zd\n", ret);
450 return ret < 0 ? ret : -ENODEV;
451 }
452 prot += ret;
453 }
454
455 return 0;
456 }
457
458 static int
459 fd_do_prot_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
460 {
461 void *buf;
462 int rc;
463
464 buf = (void *)__get_free_page(GFP_KERNEL);
465 if (!buf) {
466 pr_err("Unable to allocate FILEIO prot buf\n");
467 return -ENOMEM;
468 }
469 memset(buf, 0xff, PAGE_SIZE);
470
471 rc = fd_do_prot_fill(cmd->se_dev, lba, nolb, buf, PAGE_SIZE);
472
473 free_page((unsigned long)buf);
474
475 return rc;
476 }
477
478 static sense_reason_t
479 fd_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
480 {
481 struct file *file = FD_DEV(cmd->se_dev)->fd_file;
482 struct inode *inode = file->f_mapping->host;
483 int ret;
484
485 if (!nolb) {
486 return 0;
487 }
488
489 if (cmd->se_dev->dev_attrib.pi_prot_type) {
490 ret = fd_do_prot_unmap(cmd, lba, nolb);
491 if (ret)
492 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
493 }
494
495 if (S_ISBLK(inode->i_mode)) {
496 /* The backend is block device, use discard */
497 struct block_device *bdev = inode->i_bdev;
498 struct se_device *dev = cmd->se_dev;
499
500 ret = blkdev_issue_discard(bdev,
501 target_to_linux_sector(dev, lba),
502 target_to_linux_sector(dev, nolb),
503 GFP_KERNEL, 0);
504 if (ret < 0) {
505 pr_warn("FILEIO: blkdev_issue_discard() failed: %d\n",
506 ret);
507 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
508 }
509 } else {
510 /* The backend is normal file, use fallocate */
511 struct se_device *se_dev = cmd->se_dev;
512 loff_t pos = lba * se_dev->dev_attrib.block_size;
513 unsigned int len = nolb * se_dev->dev_attrib.block_size;
514 int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
515
516 if (!file->f_op->fallocate)
517 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
518
519 ret = file->f_op->fallocate(file, mode, pos, len);
520 if (ret < 0) {
521 pr_warn("FILEIO: fallocate() failed: %d\n", ret);
522 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
523 }
524 }
525
526 return 0;
527 }
528
529 static sense_reason_t
530 fd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
531 enum dma_data_direction data_direction)
532 {
533 struct se_device *dev = cmd->se_dev;
534 struct fd_dev *fd_dev = FD_DEV(dev);
535 struct file *file = fd_dev->fd_file;
536 struct file *pfile = fd_dev->fd_prot_file;
537 sense_reason_t rc;
538 int ret = 0;
539 /*
540 * We are currently limited by the number of iovecs (2048) per
541 * single vfs_[writev,readv] call.
542 */
543 if (cmd->data_length > FD_MAX_BYTES) {
544 pr_err("FILEIO: Not able to process I/O of %u bytes due to"
545 "FD_MAX_BYTES: %u iovec count limitation\n",
546 cmd->data_length, FD_MAX_BYTES);
547 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
548 }
549 /*
550 * Call vectorized fileio functions to map struct scatterlist
551 * physical memory addresses to struct iovec virtual memory.
552 */
553 if (data_direction == DMA_FROM_DEVICE) {
554 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
555 ret = fd_do_rw(cmd, pfile, dev->prot_length,
556 cmd->t_prot_sg, cmd->t_prot_nents,
557 cmd->prot_length, 0);
558 if (ret < 0)
559 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
560 }
561
562 ret = fd_do_rw(cmd, file, dev->dev_attrib.block_size,
563 sgl, sgl_nents, cmd->data_length, 0);
564
565 if (ret > 0 && cmd->prot_type && dev->dev_attrib.pi_prot_type &&
566 dev->dev_attrib.pi_prot_verify) {
567 u32 sectors = cmd->data_length >>
568 ilog2(dev->dev_attrib.block_size);
569
570 rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors,
571 0, cmd->t_prot_sg, 0);
572 if (rc)
573 return rc;
574 }
575 } else {
576 if (cmd->prot_type && dev->dev_attrib.pi_prot_type &&
577 dev->dev_attrib.pi_prot_verify) {
578 u32 sectors = cmd->data_length >>
579 ilog2(dev->dev_attrib.block_size);
580
581 rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors,
582 0, cmd->t_prot_sg, 0);
583 if (rc)
584 return rc;
585 }
586
587 ret = fd_do_rw(cmd, file, dev->dev_attrib.block_size,
588 sgl, sgl_nents, cmd->data_length, 1);
589 /*
590 * Perform implicit vfs_fsync_range() for fd_do_writev() ops
591 * for SCSI WRITEs with Forced Unit Access (FUA) set.
592 * Allow this to happen independent of WCE=0 setting.
593 */
594 if (ret > 0 && (cmd->se_cmd_flags & SCF_FUA)) {
595 loff_t start = cmd->t_task_lba *
596 dev->dev_attrib.block_size;
597 loff_t end;
598
599 if (cmd->data_length)
600 end = start + cmd->data_length - 1;
601 else
602 end = LLONG_MAX;
603
604 vfs_fsync_range(fd_dev->fd_file, start, end, 1);
605 }
606
607 if (ret > 0 && cmd->prot_type && dev->dev_attrib.pi_prot_type) {
608 ret = fd_do_rw(cmd, pfile, dev->prot_length,
609 cmd->t_prot_sg, cmd->t_prot_nents,
610 cmd->prot_length, 1);
611 if (ret < 0)
612 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
613 }
614 }
615
616 if (ret < 0)
617 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
618
619 target_complete_cmd(cmd, SAM_STAT_GOOD);
620 return 0;
621 }
622
623 enum {
624 Opt_fd_dev_name, Opt_fd_dev_size, Opt_fd_buffered_io, Opt_err
625 };
626
627 static match_table_t tokens = {
628 {Opt_fd_dev_name, "fd_dev_name=%s"},
629 {Opt_fd_dev_size, "fd_dev_size=%s"},
630 {Opt_fd_buffered_io, "fd_buffered_io=%d"},
631 {Opt_err, NULL}
632 };
633
634 static ssize_t fd_set_configfs_dev_params(struct se_device *dev,
635 const char *page, ssize_t count)
636 {
637 struct fd_dev *fd_dev = FD_DEV(dev);
638 char *orig, *ptr, *arg_p, *opts;
639 substring_t args[MAX_OPT_ARGS];
640 int ret = 0, arg, token;
641
642 opts = kstrdup(page, GFP_KERNEL);
643 if (!opts)
644 return -ENOMEM;
645
646 orig = opts;
647
648 while ((ptr = strsep(&opts, ",\n")) != NULL) {
649 if (!*ptr)
650 continue;
651
652 token = match_token(ptr, tokens, args);
653 switch (token) {
654 case Opt_fd_dev_name:
655 if (match_strlcpy(fd_dev->fd_dev_name, &args[0],
656 FD_MAX_DEV_NAME) == 0) {
657 ret = -EINVAL;
658 break;
659 }
660 pr_debug("FILEIO: Referencing Path: %s\n",
661 fd_dev->fd_dev_name);
662 fd_dev->fbd_flags |= FBDF_HAS_PATH;
663 break;
664 case Opt_fd_dev_size:
665 arg_p = match_strdup(&args[0]);
666 if (!arg_p) {
667 ret = -ENOMEM;
668 break;
669 }
670 ret = kstrtoull(arg_p, 0, &fd_dev->fd_dev_size);
671 kfree(arg_p);
672 if (ret < 0) {
673 pr_err("kstrtoull() failed for"
674 " fd_dev_size=\n");
675 goto out;
676 }
677 pr_debug("FILEIO: Referencing Size: %llu"
678 " bytes\n", fd_dev->fd_dev_size);
679 fd_dev->fbd_flags |= FBDF_HAS_SIZE;
680 break;
681 case Opt_fd_buffered_io:
682 ret = match_int(args, &arg);
683 if (ret)
684 goto out;
685 if (arg != 1) {
686 pr_err("bogus fd_buffered_io=%d value\n", arg);
687 ret = -EINVAL;
688 goto out;
689 }
690
691 pr_debug("FILEIO: Using buffered I/O"
692 " operations for struct fd_dev\n");
693
694 fd_dev->fbd_flags |= FDBD_HAS_BUFFERED_IO_WCE;
695 break;
696 default:
697 break;
698 }
699 }
700
701 out:
702 kfree(orig);
703 return (!ret) ? count : ret;
704 }
705
706 static ssize_t fd_show_configfs_dev_params(struct se_device *dev, char *b)
707 {
708 struct fd_dev *fd_dev = FD_DEV(dev);
709 ssize_t bl = 0;
710
711 bl = sprintf(b + bl, "TCM FILEIO ID: %u", fd_dev->fd_dev_id);
712 bl += sprintf(b + bl, " File: %s Size: %llu Mode: %s\n",
713 fd_dev->fd_dev_name, fd_dev->fd_dev_size,
714 (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) ?
715 "Buffered-WCE" : "O_DSYNC");
716 return bl;
717 }
718
719 static sector_t fd_get_blocks(struct se_device *dev)
720 {
721 struct fd_dev *fd_dev = FD_DEV(dev);
722 struct file *f = fd_dev->fd_file;
723 struct inode *i = f->f_mapping->host;
724 unsigned long long dev_size;
725 /*
726 * When using a file that references an underlying struct block_device,
727 * ensure dev_size is always based on the current inode size in order
728 * to handle underlying block_device resize operations.
729 */
730 if (S_ISBLK(i->i_mode))
731 dev_size = i_size_read(i);
732 else
733 dev_size = fd_dev->fd_dev_size;
734
735 return div_u64(dev_size - dev->dev_attrib.block_size,
736 dev->dev_attrib.block_size);
737 }
738
739 static int fd_init_prot(struct se_device *dev)
740 {
741 struct fd_dev *fd_dev = FD_DEV(dev);
742 struct file *prot_file, *file = fd_dev->fd_file;
743 struct inode *inode;
744 int ret, flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
745 char buf[FD_MAX_DEV_PROT_NAME];
746
747 if (!file) {
748 pr_err("Unable to locate fd_dev->fd_file\n");
749 return -ENODEV;
750 }
751
752 inode = file->f_mapping->host;
753 if (S_ISBLK(inode->i_mode)) {
754 pr_err("FILEIO Protection emulation only supported on"
755 " !S_ISBLK\n");
756 return -ENOSYS;
757 }
758
759 if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE)
760 flags &= ~O_DSYNC;
761
762 snprintf(buf, FD_MAX_DEV_PROT_NAME, "%s.protection",
763 fd_dev->fd_dev_name);
764
765 prot_file = filp_open(buf, flags, 0600);
766 if (IS_ERR(prot_file)) {
767 pr_err("filp_open(%s) failed\n", buf);
768 ret = PTR_ERR(prot_file);
769 return ret;
770 }
771 fd_dev->fd_prot_file = prot_file;
772
773 return 0;
774 }
775
776 static int fd_format_prot(struct se_device *dev)
777 {
778 unsigned char *buf;
779 int unit_size = FDBD_FORMAT_UNIT_SIZE * dev->dev_attrib.block_size;
780 int ret;
781
782 if (!dev->dev_attrib.pi_prot_type) {
783 pr_err("Unable to format_prot while pi_prot_type == 0\n");
784 return -ENODEV;
785 }
786
787 buf = vzalloc(unit_size);
788 if (!buf) {
789 pr_err("Unable to allocate FILEIO prot buf\n");
790 return -ENOMEM;
791 }
792
793 pr_debug("Using FILEIO prot_length: %llu\n",
794 (unsigned long long)(dev->transport->get_blocks(dev) + 1) *
795 dev->prot_length);
796
797 memset(buf, 0xff, unit_size);
798 ret = fd_do_prot_fill(dev, 0, dev->transport->get_blocks(dev) + 1,
799 buf, unit_size);
800 vfree(buf);
801 return ret;
802 }
803
804 static void fd_free_prot(struct se_device *dev)
805 {
806 struct fd_dev *fd_dev = FD_DEV(dev);
807
808 if (!fd_dev->fd_prot_file)
809 return;
810
811 filp_close(fd_dev->fd_prot_file, NULL);
812 fd_dev->fd_prot_file = NULL;
813 }
814
815 static struct sbc_ops fd_sbc_ops = {
816 .execute_rw = fd_execute_rw,
817 .execute_sync_cache = fd_execute_sync_cache,
818 .execute_write_same = fd_execute_write_same,
819 .execute_unmap = fd_execute_unmap,
820 };
821
822 static sense_reason_t
823 fd_parse_cdb(struct se_cmd *cmd)
824 {
825 return sbc_parse_cdb(cmd, &fd_sbc_ops);
826 }
827
828 static const struct target_backend_ops fileio_ops = {
829 .name = "fileio",
830 .inquiry_prod = "FILEIO",
831 .inquiry_rev = FD_VERSION,
832 .owner = THIS_MODULE,
833 .attach_hba = fd_attach_hba,
834 .detach_hba = fd_detach_hba,
835 .alloc_device = fd_alloc_device,
836 .configure_device = fd_configure_device,
837 .destroy_device = fd_destroy_device,
838 .free_device = fd_free_device,
839 .parse_cdb = fd_parse_cdb,
840 .set_configfs_dev_params = fd_set_configfs_dev_params,
841 .show_configfs_dev_params = fd_show_configfs_dev_params,
842 .get_device_type = sbc_get_device_type,
843 .get_blocks = fd_get_blocks,
844 .init_prot = fd_init_prot,
845 .format_prot = fd_format_prot,
846 .free_prot = fd_free_prot,
847 .tb_dev_attrib_attrs = sbc_attrib_attrs,
848 };
849
850 static int __init fileio_module_init(void)
851 {
852 return transport_backend_register(&fileio_ops);
853 }
854
855 static void __exit fileio_module_exit(void)
856 {
857 target_backend_unregister(&fileio_ops);
858 }
859
860 MODULE_DESCRIPTION("TCM FILEIO subsystem plugin");
861 MODULE_AUTHOR("nab@Linux-iSCSI.org");
862 MODULE_LICENSE("GPL");
863
864 module_init(fileio_module_init);
865 module_exit(fileio_module_exit);
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