GNU Linux-libre 4.19.263-gnu1
[releases.git] / drivers / target / target_core_file.c
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 struct target_core_file_cmd {
254         unsigned long   len;
255         struct se_cmd   *cmd;
256         struct kiocb    iocb;
257 };
258
259 static void cmd_rw_aio_complete(struct kiocb *iocb, long ret, long ret2)
260 {
261         struct target_core_file_cmd *cmd;
262
263         cmd = container_of(iocb, struct target_core_file_cmd, iocb);
264
265         if (ret != cmd->len)
266                 target_complete_cmd(cmd->cmd, SAM_STAT_CHECK_CONDITION);
267         else
268                 target_complete_cmd(cmd->cmd, SAM_STAT_GOOD);
269
270         kfree(cmd);
271 }
272
273 static sense_reason_t
274 fd_execute_rw_aio(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
275               enum dma_data_direction data_direction)
276 {
277         int is_write = !(data_direction == DMA_FROM_DEVICE);
278         struct se_device *dev = cmd->se_dev;
279         struct fd_dev *fd_dev = FD_DEV(dev);
280         struct file *file = fd_dev->fd_file;
281         struct target_core_file_cmd *aio_cmd;
282         struct iov_iter iter = {};
283         struct scatterlist *sg;
284         struct bio_vec *bvec;
285         ssize_t len = 0;
286         int ret = 0, i;
287
288         aio_cmd = kmalloc(sizeof(struct target_core_file_cmd), GFP_KERNEL);
289         if (!aio_cmd)
290                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
291
292         bvec = kcalloc(sgl_nents, sizeof(struct bio_vec), GFP_KERNEL);
293         if (!bvec) {
294                 kfree(aio_cmd);
295                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
296         }
297
298         for_each_sg(sgl, sg, sgl_nents, i) {
299                 bvec[i].bv_page = sg_page(sg);
300                 bvec[i].bv_len = sg->length;
301                 bvec[i].bv_offset = sg->offset;
302
303                 len += sg->length;
304         }
305
306         iov_iter_bvec(&iter, ITER_BVEC | is_write, bvec, sgl_nents, len);
307
308         aio_cmd->cmd = cmd;
309         aio_cmd->len = len;
310         aio_cmd->iocb.ki_pos = cmd->t_task_lba * dev->dev_attrib.block_size;
311         aio_cmd->iocb.ki_filp = file;
312         aio_cmd->iocb.ki_complete = cmd_rw_aio_complete;
313         aio_cmd->iocb.ki_flags = IOCB_DIRECT;
314
315         if (is_write && (cmd->se_cmd_flags & SCF_FUA))
316                 aio_cmd->iocb.ki_flags |= IOCB_DSYNC;
317
318         if (is_write)
319                 ret = call_write_iter(file, &aio_cmd->iocb, &iter);
320         else
321                 ret = call_read_iter(file, &aio_cmd->iocb, &iter);
322
323         kfree(bvec);
324
325         if (ret != -EIOCBQUEUED)
326                 cmd_rw_aio_complete(&aio_cmd->iocb, ret, 0);
327
328         return 0;
329 }
330
331 static int fd_do_rw(struct se_cmd *cmd, struct file *fd,
332                     u32 block_size, struct scatterlist *sgl,
333                     u32 sgl_nents, u32 data_length, int is_write)
334 {
335         struct scatterlist *sg;
336         struct iov_iter iter;
337         struct bio_vec *bvec;
338         ssize_t len = 0;
339         loff_t pos = (cmd->t_task_lba * block_size);
340         int ret = 0, i;
341
342         bvec = kcalloc(sgl_nents, sizeof(struct bio_vec), GFP_KERNEL);
343         if (!bvec) {
344                 pr_err("Unable to allocate fd_do_readv iov[]\n");
345                 return -ENOMEM;
346         }
347
348         for_each_sg(sgl, sg, sgl_nents, i) {
349                 bvec[i].bv_page = sg_page(sg);
350                 bvec[i].bv_len = sg->length;
351                 bvec[i].bv_offset = sg->offset;
352
353                 len += sg->length;
354         }
355
356         iov_iter_bvec(&iter, ITER_BVEC, bvec, sgl_nents, len);
357         if (is_write)
358                 ret = vfs_iter_write(fd, &iter, &pos, 0);
359         else
360                 ret = vfs_iter_read(fd, &iter, &pos, 0);
361
362         if (is_write) {
363                 if (ret < 0 || ret != data_length) {
364                         pr_err("%s() write returned %d\n", __func__, ret);
365                         if (ret >= 0)
366                                 ret = -EINVAL;
367                 }
368         } else {
369                 /*
370                  * Return zeros and GOOD status even if the READ did not return
371                  * the expected virt_size for struct file w/o a backing struct
372                  * block_device.
373                  */
374                 if (S_ISBLK(file_inode(fd)->i_mode)) {
375                         if (ret < 0 || ret != data_length) {
376                                 pr_err("%s() returned %d, expecting %u for "
377                                                 "S_ISBLK\n", __func__, ret,
378                                                 data_length);
379                                 if (ret >= 0)
380                                         ret = -EINVAL;
381                         }
382                 } else {
383                         if (ret < 0) {
384                                 pr_err("%s() returned %d for non S_ISBLK\n",
385                                                 __func__, ret);
386                         } else if (ret != data_length) {
387                                 /*
388                                  * Short read case:
389                                  * Probably some one truncate file under us.
390                                  * We must explicitly zero sg-pages to prevent
391                                  * expose uninizialized pages to userspace.
392                                  */
393                                 if (ret < data_length)
394                                         ret += iov_iter_zero(data_length - ret, &iter);
395                                 else
396                                         ret = -EINVAL;
397                         }
398                 }
399         }
400         kfree(bvec);
401         return ret;
402 }
403
404 static sense_reason_t
405 fd_execute_sync_cache(struct se_cmd *cmd)
406 {
407         struct se_device *dev = cmd->se_dev;
408         struct fd_dev *fd_dev = FD_DEV(dev);
409         int immed = (cmd->t_task_cdb[1] & 0x2);
410         loff_t start, end;
411         int ret;
412
413         /*
414          * If the Immediate bit is set, queue up the GOOD response
415          * for this SYNCHRONIZE_CACHE op
416          */
417         if (immed)
418                 target_complete_cmd(cmd, SAM_STAT_GOOD);
419
420         /*
421          * Determine if we will be flushing the entire device.
422          */
423         if (cmd->t_task_lba == 0 && cmd->data_length == 0) {
424                 start = 0;
425                 end = LLONG_MAX;
426         } else {
427                 start = cmd->t_task_lba * dev->dev_attrib.block_size;
428                 if (cmd->data_length)
429                         end = start + cmd->data_length - 1;
430                 else
431                         end = LLONG_MAX;
432         }
433
434         ret = vfs_fsync_range(fd_dev->fd_file, start, end, 1);
435         if (ret != 0)
436                 pr_err("FILEIO: vfs_fsync_range() failed: %d\n", ret);
437
438         if (immed)
439                 return 0;
440
441         if (ret)
442                 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
443         else
444                 target_complete_cmd(cmd, SAM_STAT_GOOD);
445
446         return 0;
447 }
448
449 static sense_reason_t
450 fd_execute_write_same(struct se_cmd *cmd)
451 {
452         struct se_device *se_dev = cmd->se_dev;
453         struct fd_dev *fd_dev = FD_DEV(se_dev);
454         loff_t pos = cmd->t_task_lba * se_dev->dev_attrib.block_size;
455         sector_t nolb = sbc_get_write_same_sectors(cmd);
456         struct iov_iter iter;
457         struct bio_vec *bvec;
458         unsigned int len = 0, i;
459         ssize_t ret;
460
461         if (!nolb) {
462                 target_complete_cmd(cmd, SAM_STAT_GOOD);
463                 return 0;
464         }
465         if (cmd->prot_op) {
466                 pr_err("WRITE_SAME: Protection information with FILEIO"
467                        " backends not supported\n");
468                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
469         }
470
471         if (cmd->t_data_nents > 1 ||
472             cmd->t_data_sg[0].length != cmd->se_dev->dev_attrib.block_size) {
473                 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
474                         " block_size: %u\n",
475                         cmd->t_data_nents,
476                         cmd->t_data_sg[0].length,
477                         cmd->se_dev->dev_attrib.block_size);
478                 return TCM_INVALID_CDB_FIELD;
479         }
480
481         bvec = kcalloc(nolb, sizeof(struct bio_vec), GFP_KERNEL);
482         if (!bvec)
483                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
484
485         for (i = 0; i < nolb; i++) {
486                 bvec[i].bv_page = sg_page(&cmd->t_data_sg[0]);
487                 bvec[i].bv_len = cmd->t_data_sg[0].length;
488                 bvec[i].bv_offset = cmd->t_data_sg[0].offset;
489
490                 len += se_dev->dev_attrib.block_size;
491         }
492
493         iov_iter_bvec(&iter, ITER_BVEC, bvec, nolb, len);
494         ret = vfs_iter_write(fd_dev->fd_file, &iter, &pos, 0);
495
496         kfree(bvec);
497         if (ret < 0 || ret != len) {
498                 pr_err("vfs_iter_write() returned %zd for write same\n", ret);
499                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
500         }
501
502         target_complete_cmd(cmd, SAM_STAT_GOOD);
503         return 0;
504 }
505
506 static int
507 fd_do_prot_fill(struct se_device *se_dev, sector_t lba, sector_t nolb,
508                 void *buf, size_t bufsize)
509 {
510         struct fd_dev *fd_dev = FD_DEV(se_dev);
511         struct file *prot_fd = fd_dev->fd_prot_file;
512         sector_t prot_length, prot;
513         loff_t pos = lba * se_dev->prot_length;
514
515         if (!prot_fd) {
516                 pr_err("Unable to locate fd_dev->fd_prot_file\n");
517                 return -ENODEV;
518         }
519
520         prot_length = nolb * se_dev->prot_length;
521
522         for (prot = 0; prot < prot_length;) {
523                 sector_t len = min_t(sector_t, bufsize, prot_length - prot);
524                 ssize_t ret = kernel_write(prot_fd, buf, len, &pos);
525
526                 if (ret != len) {
527                         pr_err("vfs_write to prot file failed: %zd\n", ret);
528                         return ret < 0 ? ret : -ENODEV;
529                 }
530                 prot += ret;
531         }
532
533         return 0;
534 }
535
536 static int
537 fd_do_prot_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
538 {
539         void *buf;
540         int rc;
541
542         buf = (void *)__get_free_page(GFP_KERNEL);
543         if (!buf) {
544                 pr_err("Unable to allocate FILEIO prot buf\n");
545                 return -ENOMEM;
546         }
547         memset(buf, 0xff, PAGE_SIZE);
548
549         rc = fd_do_prot_fill(cmd->se_dev, lba, nolb, buf, PAGE_SIZE);
550
551         free_page((unsigned long)buf);
552
553         return rc;
554 }
555
556 static sense_reason_t
557 fd_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
558 {
559         struct file *file = FD_DEV(cmd->se_dev)->fd_file;
560         struct inode *inode = file->f_mapping->host;
561         int ret;
562
563         if (!nolb) {
564                 return 0;
565         }
566
567         if (cmd->se_dev->dev_attrib.pi_prot_type) {
568                 ret = fd_do_prot_unmap(cmd, lba, nolb);
569                 if (ret)
570                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
571         }
572
573         if (S_ISBLK(inode->i_mode)) {
574                 /* The backend is block device, use discard */
575                 struct block_device *bdev = inode->i_bdev;
576                 struct se_device *dev = cmd->se_dev;
577
578                 ret = blkdev_issue_discard(bdev,
579                                            target_to_linux_sector(dev, lba),
580                                            target_to_linux_sector(dev,  nolb),
581                                            GFP_KERNEL, 0);
582                 if (ret < 0) {
583                         pr_warn("FILEIO: blkdev_issue_discard() failed: %d\n",
584                                 ret);
585                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
586                 }
587         } else {
588                 /* The backend is normal file, use fallocate */
589                 struct se_device *se_dev = cmd->se_dev;
590                 loff_t pos = lba * se_dev->dev_attrib.block_size;
591                 unsigned int len = nolb * se_dev->dev_attrib.block_size;
592                 int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
593
594                 if (!file->f_op->fallocate)
595                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
596
597                 ret = file->f_op->fallocate(file, mode, pos, len);
598                 if (ret < 0) {
599                         pr_warn("FILEIO: fallocate() failed: %d\n", ret);
600                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
601                 }
602         }
603
604         return 0;
605 }
606
607 static sense_reason_t
608 fd_execute_rw_buffered(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
609               enum dma_data_direction data_direction)
610 {
611         struct se_device *dev = cmd->se_dev;
612         struct fd_dev *fd_dev = FD_DEV(dev);
613         struct file *file = fd_dev->fd_file;
614         struct file *pfile = fd_dev->fd_prot_file;
615         sense_reason_t rc;
616         int ret = 0;
617         /*
618          * Call vectorized fileio functions to map struct scatterlist
619          * physical memory addresses to struct iovec virtual memory.
620          */
621         if (data_direction == DMA_FROM_DEVICE) {
622                 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
623                         ret = fd_do_rw(cmd, pfile, dev->prot_length,
624                                        cmd->t_prot_sg, cmd->t_prot_nents,
625                                        cmd->prot_length, 0);
626                         if (ret < 0)
627                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
628                 }
629
630                 ret = fd_do_rw(cmd, file, dev->dev_attrib.block_size,
631                                sgl, sgl_nents, cmd->data_length, 0);
632
633                 if (ret > 0 && cmd->prot_type && dev->dev_attrib.pi_prot_type &&
634                     dev->dev_attrib.pi_prot_verify) {
635                         u32 sectors = cmd->data_length >>
636                                         ilog2(dev->dev_attrib.block_size);
637
638                         rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors,
639                                             0, cmd->t_prot_sg, 0);
640                         if (rc)
641                                 return rc;
642                 }
643         } else {
644                 if (cmd->prot_type && dev->dev_attrib.pi_prot_type &&
645                     dev->dev_attrib.pi_prot_verify) {
646                         u32 sectors = cmd->data_length >>
647                                         ilog2(dev->dev_attrib.block_size);
648
649                         rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors,
650                                             0, cmd->t_prot_sg, 0);
651                         if (rc)
652                                 return rc;
653                 }
654
655                 ret = fd_do_rw(cmd, file, dev->dev_attrib.block_size,
656                                sgl, sgl_nents, cmd->data_length, 1);
657                 /*
658                  * Perform implicit vfs_fsync_range() for fd_do_writev() ops
659                  * for SCSI WRITEs with Forced Unit Access (FUA) set.
660                  * Allow this to happen independent of WCE=0 setting.
661                  */
662                 if (ret > 0 && (cmd->se_cmd_flags & SCF_FUA)) {
663                         loff_t start = cmd->t_task_lba *
664                                 dev->dev_attrib.block_size;
665                         loff_t end;
666
667                         if (cmd->data_length)
668                                 end = start + cmd->data_length - 1;
669                         else
670                                 end = LLONG_MAX;
671
672                         vfs_fsync_range(fd_dev->fd_file, start, end, 1);
673                 }
674
675                 if (ret > 0 && cmd->prot_type && dev->dev_attrib.pi_prot_type) {
676                         ret = fd_do_rw(cmd, pfile, dev->prot_length,
677                                        cmd->t_prot_sg, cmd->t_prot_nents,
678                                        cmd->prot_length, 1);
679                         if (ret < 0)
680                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
681                 }
682         }
683
684         if (ret < 0)
685                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
686
687         target_complete_cmd(cmd, SAM_STAT_GOOD);
688         return 0;
689 }
690
691 static sense_reason_t
692 fd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
693               enum dma_data_direction data_direction)
694 {
695         struct se_device *dev = cmd->se_dev;
696         struct fd_dev *fd_dev = FD_DEV(dev);
697
698         /*
699          * We are currently limited by the number of iovecs (2048) per
700          * single vfs_[writev,readv] call.
701          */
702         if (cmd->data_length > FD_MAX_BYTES) {
703                 pr_err("FILEIO: Not able to process I/O of %u bytes due to"
704                        "FD_MAX_BYTES: %u iovec count limitation\n",
705                         cmd->data_length, FD_MAX_BYTES);
706                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
707         }
708
709         if (fd_dev->fbd_flags & FDBD_HAS_ASYNC_IO)
710                 return fd_execute_rw_aio(cmd, sgl, sgl_nents, data_direction);
711         return fd_execute_rw_buffered(cmd, sgl, sgl_nents, data_direction);
712 }
713
714 enum {
715         Opt_fd_dev_name, Opt_fd_dev_size, Opt_fd_buffered_io,
716         Opt_fd_async_io, Opt_err
717 };
718
719 static match_table_t tokens = {
720         {Opt_fd_dev_name, "fd_dev_name=%s"},
721         {Opt_fd_dev_size, "fd_dev_size=%s"},
722         {Opt_fd_buffered_io, "fd_buffered_io=%d"},
723         {Opt_fd_async_io, "fd_async_io=%d"},
724         {Opt_err, NULL}
725 };
726
727 static ssize_t fd_set_configfs_dev_params(struct se_device *dev,
728                 const char *page, ssize_t count)
729 {
730         struct fd_dev *fd_dev = FD_DEV(dev);
731         char *orig, *ptr, *arg_p, *opts;
732         substring_t args[MAX_OPT_ARGS];
733         int ret = 0, arg, token;
734
735         opts = kstrdup(page, GFP_KERNEL);
736         if (!opts)
737                 return -ENOMEM;
738
739         orig = opts;
740
741         while ((ptr = strsep(&opts, ",\n")) != NULL) {
742                 if (!*ptr)
743                         continue;
744
745                 token = match_token(ptr, tokens, args);
746                 switch (token) {
747                 case Opt_fd_dev_name:
748                         if (match_strlcpy(fd_dev->fd_dev_name, &args[0],
749                                 FD_MAX_DEV_NAME) == 0) {
750                                 ret = -EINVAL;
751                                 break;
752                         }
753                         pr_debug("FILEIO: Referencing Path: %s\n",
754                                         fd_dev->fd_dev_name);
755                         fd_dev->fbd_flags |= FBDF_HAS_PATH;
756                         break;
757                 case Opt_fd_dev_size:
758                         arg_p = match_strdup(&args[0]);
759                         if (!arg_p) {
760                                 ret = -ENOMEM;
761                                 break;
762                         }
763                         ret = kstrtoull(arg_p, 0, &fd_dev->fd_dev_size);
764                         kfree(arg_p);
765                         if (ret < 0) {
766                                 pr_err("kstrtoull() failed for"
767                                                 " fd_dev_size=\n");
768                                 goto out;
769                         }
770                         pr_debug("FILEIO: Referencing Size: %llu"
771                                         " bytes\n", fd_dev->fd_dev_size);
772                         fd_dev->fbd_flags |= FBDF_HAS_SIZE;
773                         break;
774                 case Opt_fd_buffered_io:
775                         ret = match_int(args, &arg);
776                         if (ret)
777                                 goto out;
778                         if (arg != 1) {
779                                 pr_err("bogus fd_buffered_io=%d value\n", arg);
780                                 ret = -EINVAL;
781                                 goto out;
782                         }
783
784                         pr_debug("FILEIO: Using buffered I/O"
785                                 " operations for struct fd_dev\n");
786
787                         fd_dev->fbd_flags |= FDBD_HAS_BUFFERED_IO_WCE;
788                         break;
789                 case Opt_fd_async_io:
790                         ret = match_int(args, &arg);
791                         if (ret)
792                                 goto out;
793                         if (arg != 1) {
794                                 pr_err("bogus fd_async_io=%d value\n", arg);
795                                 ret = -EINVAL;
796                                 goto out;
797                         }
798
799                         pr_debug("FILEIO: Using async I/O"
800                                 " operations for struct fd_dev\n");
801
802                         fd_dev->fbd_flags |= FDBD_HAS_ASYNC_IO;
803                         break;
804                 default:
805                         break;
806                 }
807         }
808
809 out:
810         kfree(orig);
811         return (!ret) ? count : ret;
812 }
813
814 static ssize_t fd_show_configfs_dev_params(struct se_device *dev, char *b)
815 {
816         struct fd_dev *fd_dev = FD_DEV(dev);
817         ssize_t bl = 0;
818
819         bl = sprintf(b + bl, "TCM FILEIO ID: %u", fd_dev->fd_dev_id);
820         bl += sprintf(b + bl, "        File: %s  Size: %llu  Mode: %s Async: %d\n",
821                 fd_dev->fd_dev_name, fd_dev->fd_dev_size,
822                 (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) ?
823                 "Buffered-WCE" : "O_DSYNC",
824                 !!(fd_dev->fbd_flags & FDBD_HAS_ASYNC_IO));
825         return bl;
826 }
827
828 static sector_t fd_get_blocks(struct se_device *dev)
829 {
830         struct fd_dev *fd_dev = FD_DEV(dev);
831         struct file *f = fd_dev->fd_file;
832         struct inode *i = f->f_mapping->host;
833         unsigned long long dev_size;
834         /*
835          * When using a file that references an underlying struct block_device,
836          * ensure dev_size is always based on the current inode size in order
837          * to handle underlying block_device resize operations.
838          */
839         if (S_ISBLK(i->i_mode))
840                 dev_size = i_size_read(i);
841         else
842                 dev_size = fd_dev->fd_dev_size;
843
844         return div_u64(dev_size - dev->dev_attrib.block_size,
845                        dev->dev_attrib.block_size);
846 }
847
848 static int fd_init_prot(struct se_device *dev)
849 {
850         struct fd_dev *fd_dev = FD_DEV(dev);
851         struct file *prot_file, *file = fd_dev->fd_file;
852         struct inode *inode;
853         int ret, flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
854         char buf[FD_MAX_DEV_PROT_NAME];
855
856         if (!file) {
857                 pr_err("Unable to locate fd_dev->fd_file\n");
858                 return -ENODEV;
859         }
860
861         inode = file->f_mapping->host;
862         if (S_ISBLK(inode->i_mode)) {
863                 pr_err("FILEIO Protection emulation only supported on"
864                        " !S_ISBLK\n");
865                 return -ENOSYS;
866         }
867
868         if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE)
869                 flags &= ~O_DSYNC;
870
871         snprintf(buf, FD_MAX_DEV_PROT_NAME, "%s.protection",
872                  fd_dev->fd_dev_name);
873
874         prot_file = filp_open(buf, flags, 0600);
875         if (IS_ERR(prot_file)) {
876                 pr_err("filp_open(%s) failed\n", buf);
877                 ret = PTR_ERR(prot_file);
878                 return ret;
879         }
880         fd_dev->fd_prot_file = prot_file;
881
882         return 0;
883 }
884
885 static int fd_format_prot(struct se_device *dev)
886 {
887         unsigned char *buf;
888         int unit_size = FDBD_FORMAT_UNIT_SIZE * dev->dev_attrib.block_size;
889         int ret;
890
891         if (!dev->dev_attrib.pi_prot_type) {
892                 pr_err("Unable to format_prot while pi_prot_type == 0\n");
893                 return -ENODEV;
894         }
895
896         buf = vzalloc(unit_size);
897         if (!buf) {
898                 pr_err("Unable to allocate FILEIO prot buf\n");
899                 return -ENOMEM;
900         }
901
902         pr_debug("Using FILEIO prot_length: %llu\n",
903                  (unsigned long long)(dev->transport->get_blocks(dev) + 1) *
904                                         dev->prot_length);
905
906         memset(buf, 0xff, unit_size);
907         ret = fd_do_prot_fill(dev, 0, dev->transport->get_blocks(dev) + 1,
908                               buf, unit_size);
909         vfree(buf);
910         return ret;
911 }
912
913 static void fd_free_prot(struct se_device *dev)
914 {
915         struct fd_dev *fd_dev = FD_DEV(dev);
916
917         if (!fd_dev->fd_prot_file)
918                 return;
919
920         filp_close(fd_dev->fd_prot_file, NULL);
921         fd_dev->fd_prot_file = NULL;
922 }
923
924 static struct sbc_ops fd_sbc_ops = {
925         .execute_rw             = fd_execute_rw,
926         .execute_sync_cache     = fd_execute_sync_cache,
927         .execute_write_same     = fd_execute_write_same,
928         .execute_unmap          = fd_execute_unmap,
929 };
930
931 static sense_reason_t
932 fd_parse_cdb(struct se_cmd *cmd)
933 {
934         return sbc_parse_cdb(cmd, &fd_sbc_ops);
935 }
936
937 static const struct target_backend_ops fileio_ops = {
938         .name                   = "fileio",
939         .inquiry_prod           = "FILEIO",
940         .inquiry_rev            = FD_VERSION,
941         .owner                  = THIS_MODULE,
942         .attach_hba             = fd_attach_hba,
943         .detach_hba             = fd_detach_hba,
944         .alloc_device           = fd_alloc_device,
945         .configure_device       = fd_configure_device,
946         .destroy_device         = fd_destroy_device,
947         .free_device            = fd_free_device,
948         .parse_cdb              = fd_parse_cdb,
949         .set_configfs_dev_params = fd_set_configfs_dev_params,
950         .show_configfs_dev_params = fd_show_configfs_dev_params,
951         .get_device_type        = sbc_get_device_type,
952         .get_blocks             = fd_get_blocks,
953         .init_prot              = fd_init_prot,
954         .format_prot            = fd_format_prot,
955         .free_prot              = fd_free_prot,
956         .tb_dev_attrib_attrs    = sbc_attrib_attrs,
957 };
958
959 static int __init fileio_module_init(void)
960 {
961         return transport_backend_register(&fileio_ops);
962 }
963
964 static void __exit fileio_module_exit(void)
965 {
966         target_backend_unregister(&fileio_ops);
967 }
968
969 MODULE_DESCRIPTION("TCM FILEIO subsystem plugin");
970 MODULE_AUTHOR("nab@Linux-iSCSI.org");
971 MODULE_LICENSE("GPL");
972
973 module_init(fileio_module_init);
974 module_exit(fileio_module_exit);