Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
[linux-drm-fsl-dcu.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  * Copyright (c) 2005 PyX Technologies, Inc.
7  * Copyright (c) 2005-2006 SBE, Inc.  All Rights Reserved.
8  * Copyright (c) 2007-2010 Rising Tide Systems
9  * Copyright (c) 2008-2010 Linux-iSCSI.org
10  *
11  * Nicholas A. Bellinger <nab@kernel.org>
12  *
13  * This program is free software; you can redistribute it and/or modify
14  * it under the terms of the GNU General Public License as published by
15  * the Free Software Foundation; either version 2 of the License, or
16  * (at your option) any later version.
17  *
18  * This program is distributed in the hope that it will be useful,
19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
21  * GNU General Public License for more details.
22  *
23  * You should have received a copy of the GNU General Public License
24  * along with this program; if not, write to the Free Software
25  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
26  *
27  ******************************************************************************/
28
29 #include <linux/string.h>
30 #include <linux/parser.h>
31 #include <linux/timer.h>
32 #include <linux/blkdev.h>
33 #include <linux/slab.h>
34 #include <linux/spinlock.h>
35 #include <linux/module.h>
36 #include <scsi/scsi.h>
37 #include <scsi/scsi_host.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 struct se_subsystem_api fileio_template;
45
46 /*      fd_attach_hba(): (Part of se_subsystem_api_t template)
47  *
48  *
49  */
50 static int fd_attach_hba(struct se_hba *hba, u32 host_id)
51 {
52         struct fd_host *fd_host;
53
54         fd_host = kzalloc(sizeof(struct fd_host), GFP_KERNEL);
55         if (!fd_host) {
56                 pr_err("Unable to allocate memory for struct fd_host\n");
57                 return -ENOMEM;
58         }
59
60         fd_host->fd_host_id = host_id;
61
62         hba->hba_ptr = fd_host;
63
64         pr_debug("CORE_HBA[%d] - TCM FILEIO HBA Driver %s on Generic"
65                 " Target Core Stack %s\n", hba->hba_id, FD_VERSION,
66                 TARGET_CORE_MOD_VERSION);
67         pr_debug("CORE_HBA[%d] - Attached FILEIO HBA: %u to Generic"
68                 " MaxSectors: %u\n",
69                 hba->hba_id, fd_host->fd_host_id, FD_MAX_SECTORS);
70
71         return 0;
72 }
73
74 static void fd_detach_hba(struct se_hba *hba)
75 {
76         struct fd_host *fd_host = hba->hba_ptr;
77
78         pr_debug("CORE_HBA[%d] - Detached FILEIO HBA: %u from Generic"
79                 " Target Core\n", hba->hba_id, fd_host->fd_host_id);
80
81         kfree(fd_host);
82         hba->hba_ptr = NULL;
83 }
84
85 static void *fd_allocate_virtdevice(struct se_hba *hba, const char *name)
86 {
87         struct fd_dev *fd_dev;
88         struct fd_host *fd_host = hba->hba_ptr;
89
90         fd_dev = kzalloc(sizeof(struct fd_dev), GFP_KERNEL);
91         if (!fd_dev) {
92                 pr_err("Unable to allocate memory for struct fd_dev\n");
93                 return NULL;
94         }
95
96         fd_dev->fd_host = fd_host;
97
98         pr_debug("FILEIO: Allocated fd_dev for %p\n", name);
99
100         return fd_dev;
101 }
102
103 /*      fd_create_virtdevice(): (Part of se_subsystem_api_t template)
104  *
105  *
106  */
107 static struct se_device *fd_create_virtdevice(
108         struct se_hba *hba,
109         struct se_subsystem_dev *se_dev,
110         void *p)
111 {
112         struct se_device *dev;
113         struct se_dev_limits dev_limits;
114         struct queue_limits *limits;
115         struct fd_dev *fd_dev = p;
116         struct fd_host *fd_host = hba->hba_ptr;
117         struct file *file;
118         struct inode *inode = NULL;
119         int dev_flags = 0, flags, ret = -EINVAL;
120
121         memset(&dev_limits, 0, sizeof(struct se_dev_limits));
122
123         /*
124          * Use O_DSYNC by default instead of O_SYNC to forgo syncing
125          * of pure timestamp updates.
126          */
127         flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
128
129         file = filp_open(fd_dev->fd_dev_name, flags, 0600);
130         if (IS_ERR(file)) {
131                 pr_err("filp_open(%s) failed\n", fd_dev->fd_dev_name);
132                 ret = PTR_ERR(file);
133                 goto fail;
134         }
135         fd_dev->fd_file = file;
136         /*
137          * If using a block backend with this struct file, we extract
138          * fd_dev->fd_[block,dev]_size from struct block_device.
139          *
140          * Otherwise, we use the passed fd_size= from configfs
141          */
142         inode = file->f_mapping->host;
143         if (S_ISBLK(inode->i_mode)) {
144                 struct request_queue *q;
145                 unsigned long long dev_size;
146                 /*
147                  * Setup the local scope queue_limits from struct request_queue->limits
148                  * to pass into transport_add_device_to_core_hba() as struct se_dev_limits.
149                  */
150                 q = bdev_get_queue(inode->i_bdev);
151                 limits = &dev_limits.limits;
152                 limits->logical_block_size = bdev_logical_block_size(inode->i_bdev);
153                 limits->max_hw_sectors = queue_max_hw_sectors(q);
154                 limits->max_sectors = queue_max_sectors(q);
155                 /*
156                  * Determine the number of bytes from i_size_read() minus
157                  * one (1) logical sector from underlying struct block_device
158                  */
159                 fd_dev->fd_block_size = bdev_logical_block_size(inode->i_bdev);
160                 dev_size = (i_size_read(file->f_mapping->host) -
161                                        fd_dev->fd_block_size);
162
163                 pr_debug("FILEIO: Using size: %llu bytes from struct"
164                         " block_device blocks: %llu logical_block_size: %d\n",
165                         dev_size, div_u64(dev_size, fd_dev->fd_block_size),
166                         fd_dev->fd_block_size);
167         } else {
168                 if (!(fd_dev->fbd_flags & FBDF_HAS_SIZE)) {
169                         pr_err("FILEIO: Missing fd_dev_size="
170                                 " parameter, and no backing struct"
171                                 " block_device\n");
172                         goto fail;
173                 }
174
175                 limits = &dev_limits.limits;
176                 limits->logical_block_size = FD_BLOCKSIZE;
177                 limits->max_hw_sectors = FD_MAX_SECTORS;
178                 limits->max_sectors = FD_MAX_SECTORS;
179                 fd_dev->fd_block_size = FD_BLOCKSIZE;
180         }
181
182         dev_limits.hw_queue_depth = FD_MAX_DEVICE_QUEUE_DEPTH;
183         dev_limits.queue_depth = FD_DEVICE_QUEUE_DEPTH;
184
185         dev = transport_add_device_to_core_hba(hba, &fileio_template,
186                                 se_dev, dev_flags, fd_dev,
187                                 &dev_limits, "FILEIO", FD_VERSION);
188         if (!dev)
189                 goto fail;
190
191         fd_dev->fd_dev_id = fd_host->fd_host_dev_id_count++;
192         fd_dev->fd_queue_depth = dev->queue_depth;
193
194         pr_debug("CORE_FILE[%u] - Added TCM FILEIO Device ID: %u at %s,"
195                 " %llu total bytes\n", fd_host->fd_host_id, fd_dev->fd_dev_id,
196                         fd_dev->fd_dev_name, fd_dev->fd_dev_size);
197
198         return dev;
199 fail:
200         if (fd_dev->fd_file) {
201                 filp_close(fd_dev->fd_file, NULL);
202                 fd_dev->fd_file = NULL;
203         }
204         return ERR_PTR(ret);
205 }
206
207 /*      fd_free_device(): (Part of se_subsystem_api_t template)
208  *
209  *
210  */
211 static void fd_free_device(void *p)
212 {
213         struct fd_dev *fd_dev = p;
214
215         if (fd_dev->fd_file) {
216                 filp_close(fd_dev->fd_file, NULL);
217                 fd_dev->fd_file = NULL;
218         }
219
220         kfree(fd_dev);
221 }
222
223 static int fd_do_readv(struct se_cmd *cmd, struct scatterlist *sgl,
224                 u32 sgl_nents)
225 {
226         struct se_device *se_dev = cmd->se_dev;
227         struct fd_dev *dev = se_dev->dev_ptr;
228         struct file *fd = dev->fd_file;
229         struct scatterlist *sg;
230         struct iovec *iov;
231         mm_segment_t old_fs;
232         loff_t pos = (cmd->t_task_lba *
233                       se_dev->se_sub_dev->se_dev_attrib.block_size);
234         int ret = 0, i;
235
236         iov = kzalloc(sizeof(struct iovec) * sgl_nents, GFP_KERNEL);
237         if (!iov) {
238                 pr_err("Unable to allocate fd_do_readv iov[]\n");
239                 return -ENOMEM;
240         }
241
242         for_each_sg(sgl, sg, sgl_nents, i) {
243                 iov[i].iov_len = sg->length;
244                 iov[i].iov_base = sg_virt(sg);
245         }
246
247         old_fs = get_fs();
248         set_fs(get_ds());
249         ret = vfs_readv(fd, &iov[0], sgl_nents, &pos);
250         set_fs(old_fs);
251
252         kfree(iov);
253         /*
254          * Return zeros and GOOD status even if the READ did not return
255          * the expected virt_size for struct file w/o a backing struct
256          * block_device.
257          */
258         if (S_ISBLK(fd->f_dentry->d_inode->i_mode)) {
259                 if (ret < 0 || ret != cmd->data_length) {
260                         pr_err("vfs_readv() returned %d,"
261                                 " expecting %d for S_ISBLK\n", ret,
262                                 (int)cmd->data_length);
263                         return (ret < 0 ? ret : -EINVAL);
264                 }
265         } else {
266                 if (ret < 0) {
267                         pr_err("vfs_readv() returned %d for non"
268                                 " S_ISBLK\n", ret);
269                         return ret;
270                 }
271         }
272
273         return 1;
274 }
275
276 static int fd_do_writev(struct se_cmd *cmd, struct scatterlist *sgl,
277                 u32 sgl_nents)
278 {
279         struct se_device *se_dev = cmd->se_dev;
280         struct fd_dev *dev = se_dev->dev_ptr;
281         struct file *fd = dev->fd_file;
282         struct scatterlist *sg;
283         struct iovec *iov;
284         mm_segment_t old_fs;
285         loff_t pos = (cmd->t_task_lba *
286                       se_dev->se_sub_dev->se_dev_attrib.block_size);
287         int ret, i = 0;
288
289         iov = kzalloc(sizeof(struct iovec) * sgl_nents, GFP_KERNEL);
290         if (!iov) {
291                 pr_err("Unable to allocate fd_do_writev iov[]\n");
292                 return -ENOMEM;
293         }
294
295         for_each_sg(sgl, sg, sgl_nents, i) {
296                 iov[i].iov_len = sg->length;
297                 iov[i].iov_base = sg_virt(sg);
298         }
299
300         old_fs = get_fs();
301         set_fs(get_ds());
302         ret = vfs_writev(fd, &iov[0], sgl_nents, &pos);
303         set_fs(old_fs);
304
305         kfree(iov);
306
307         if (ret < 0 || ret != cmd->data_length) {
308                 pr_err("vfs_writev() returned %d\n", ret);
309                 return (ret < 0 ? ret : -EINVAL);
310         }
311
312         return 1;
313 }
314
315 static int fd_execute_sync_cache(struct se_cmd *cmd)
316 {
317         struct se_device *dev = cmd->se_dev;
318         struct fd_dev *fd_dev = dev->dev_ptr;
319         int immed = (cmd->t_task_cdb[1] & 0x2);
320         loff_t start, end;
321         int ret;
322
323         /*
324          * If the Immediate bit is set, queue up the GOOD response
325          * for this SYNCHRONIZE_CACHE op
326          */
327         if (immed)
328                 target_complete_cmd(cmd, SAM_STAT_GOOD);
329
330         /*
331          * Determine if we will be flushing the entire device.
332          */
333         if (cmd->t_task_lba == 0 && cmd->data_length == 0) {
334                 start = 0;
335                 end = LLONG_MAX;
336         } else {
337                 start = cmd->t_task_lba * dev->se_sub_dev->se_dev_attrib.block_size;
338                 if (cmd->data_length)
339                         end = start + cmd->data_length;
340                 else
341                         end = LLONG_MAX;
342         }
343
344         ret = vfs_fsync_range(fd_dev->fd_file, start, end, 1);
345         if (ret != 0)
346                 pr_err("FILEIO: vfs_fsync_range() failed: %d\n", ret);
347
348         if (immed)
349                 return 0;
350
351         if (ret) {
352                 cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
353                 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
354         } else {
355                 target_complete_cmd(cmd, SAM_STAT_GOOD);
356         }
357
358         return 0;
359 }
360
361 static int fd_execute_rw(struct se_cmd *cmd)
362 {
363         struct scatterlist *sgl = cmd->t_data_sg;
364         u32 sgl_nents = cmd->t_data_nents;
365         enum dma_data_direction data_direction = cmd->data_direction;
366         struct se_device *dev = cmd->se_dev;
367         int ret = 0;
368
369         /*
370          * Call vectorized fileio functions to map struct scatterlist
371          * physical memory addresses to struct iovec virtual memory.
372          */
373         if (data_direction == DMA_FROM_DEVICE) {
374                 ret = fd_do_readv(cmd, sgl, sgl_nents);
375         } else {
376                 ret = fd_do_writev(cmd, sgl, sgl_nents);
377                 /*
378                  * Perform implict vfs_fsync_range() for fd_do_writev() ops
379                  * for SCSI WRITEs with Forced Unit Access (FUA) set.
380                  * Allow this to happen independent of WCE=0 setting.
381                  */
382                 if (ret > 0 &&
383                     dev->se_sub_dev->se_dev_attrib.emulate_fua_write > 0 &&
384                     (cmd->se_cmd_flags & SCF_FUA)) {
385                         struct fd_dev *fd_dev = dev->dev_ptr;
386                         loff_t start = cmd->t_task_lba *
387                                 dev->se_sub_dev->se_dev_attrib.block_size;
388                         loff_t end = start + cmd->data_length;
389
390                         vfs_fsync_range(fd_dev->fd_file, start, end, 1);
391                 }
392         }
393
394         if (ret < 0) {
395                 cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
396                 return ret;
397         }
398         if (ret)
399                 target_complete_cmd(cmd, SAM_STAT_GOOD);
400         return 0;
401 }
402
403 enum {
404         Opt_fd_dev_name, Opt_fd_dev_size, Opt_fd_buffered_io, Opt_err
405 };
406
407 static match_table_t tokens = {
408         {Opt_fd_dev_name, "fd_dev_name=%s"},
409         {Opt_fd_dev_size, "fd_dev_size=%s"},
410         {Opt_err, NULL}
411 };
412
413 static ssize_t fd_set_configfs_dev_params(
414         struct se_hba *hba,
415         struct se_subsystem_dev *se_dev,
416         const char *page, ssize_t count)
417 {
418         struct fd_dev *fd_dev = se_dev->se_dev_su_ptr;
419         char *orig, *ptr, *arg_p, *opts;
420         substring_t args[MAX_OPT_ARGS];
421         int ret = 0, token;
422
423         opts = kstrdup(page, GFP_KERNEL);
424         if (!opts)
425                 return -ENOMEM;
426
427         orig = opts;
428
429         while ((ptr = strsep(&opts, ",\n")) != NULL) {
430                 if (!*ptr)
431                         continue;
432
433                 token = match_token(ptr, tokens, args);
434                 switch (token) {
435                 case Opt_fd_dev_name:
436                         if (match_strlcpy(fd_dev->fd_dev_name, &args[0],
437                                 FD_MAX_DEV_NAME) == 0) {
438                                 ret = -EINVAL;
439                                 break;
440                         }
441                         pr_debug("FILEIO: Referencing Path: %s\n",
442                                         fd_dev->fd_dev_name);
443                         fd_dev->fbd_flags |= FBDF_HAS_PATH;
444                         break;
445                 case Opt_fd_dev_size:
446                         arg_p = match_strdup(&args[0]);
447                         if (!arg_p) {
448                                 ret = -ENOMEM;
449                                 break;
450                         }
451                         ret = strict_strtoull(arg_p, 0, &fd_dev->fd_dev_size);
452                         kfree(arg_p);
453                         if (ret < 0) {
454                                 pr_err("strict_strtoull() failed for"
455                                                 " fd_dev_size=\n");
456                                 goto out;
457                         }
458                         pr_debug("FILEIO: Referencing Size: %llu"
459                                         " bytes\n", fd_dev->fd_dev_size);
460                         fd_dev->fbd_flags |= FBDF_HAS_SIZE;
461                         break;
462                 default:
463                         break;
464                 }
465         }
466
467 out:
468         kfree(orig);
469         return (!ret) ? count : ret;
470 }
471
472 static ssize_t fd_check_configfs_dev_params(struct se_hba *hba, struct se_subsystem_dev *se_dev)
473 {
474         struct fd_dev *fd_dev = se_dev->se_dev_su_ptr;
475
476         if (!(fd_dev->fbd_flags & FBDF_HAS_PATH)) {
477                 pr_err("Missing fd_dev_name=\n");
478                 return -EINVAL;
479         }
480
481         return 0;
482 }
483
484 static ssize_t fd_show_configfs_dev_params(
485         struct se_hba *hba,
486         struct se_subsystem_dev *se_dev,
487         char *b)
488 {
489         struct fd_dev *fd_dev = se_dev->se_dev_su_ptr;
490         ssize_t bl = 0;
491
492         bl = sprintf(b + bl, "TCM FILEIO ID: %u", fd_dev->fd_dev_id);
493         bl += sprintf(b + bl, "        File: %s  Size: %llu  Mode: O_DSYNC\n",
494                 fd_dev->fd_dev_name, fd_dev->fd_dev_size);
495         return bl;
496 }
497
498 /*      fd_get_device_rev(): (Part of se_subsystem_api_t template)
499  *
500  *
501  */
502 static u32 fd_get_device_rev(struct se_device *dev)
503 {
504         return SCSI_SPC_2; /* Returns SPC-3 in Initiator Data */
505 }
506
507 /*      fd_get_device_type(): (Part of se_subsystem_api_t template)
508  *
509  *
510  */
511 static u32 fd_get_device_type(struct se_device *dev)
512 {
513         return TYPE_DISK;
514 }
515
516 static sector_t fd_get_blocks(struct se_device *dev)
517 {
518         struct fd_dev *fd_dev = dev->dev_ptr;
519         struct file *f = fd_dev->fd_file;
520         struct inode *i = f->f_mapping->host;
521         unsigned long long dev_size;
522         /*
523          * When using a file that references an underlying struct block_device,
524          * ensure dev_size is always based on the current inode size in order
525          * to handle underlying block_device resize operations.
526          */
527         if (S_ISBLK(i->i_mode))
528                 dev_size = (i_size_read(i) - fd_dev->fd_block_size);
529         else
530                 dev_size = fd_dev->fd_dev_size;
531
532         return div_u64(dev_size, dev->se_sub_dev->se_dev_attrib.block_size);
533 }
534
535 static struct spc_ops fd_spc_ops = {
536         .execute_rw             = fd_execute_rw,
537         .execute_sync_cache     = fd_execute_sync_cache,
538 };
539
540 static int fd_parse_cdb(struct se_cmd *cmd)
541 {
542         return sbc_parse_cdb(cmd, &fd_spc_ops);
543 }
544
545 static struct se_subsystem_api fileio_template = {
546         .name                   = "fileio",
547         .owner                  = THIS_MODULE,
548         .transport_type         = TRANSPORT_PLUGIN_VHBA_PDEV,
549         .write_cache_emulated   = 1,
550         .fua_write_emulated     = 1,
551         .attach_hba             = fd_attach_hba,
552         .detach_hba             = fd_detach_hba,
553         .allocate_virtdevice    = fd_allocate_virtdevice,
554         .create_virtdevice      = fd_create_virtdevice,
555         .free_device            = fd_free_device,
556         .parse_cdb              = fd_parse_cdb,
557         .check_configfs_dev_params = fd_check_configfs_dev_params,
558         .set_configfs_dev_params = fd_set_configfs_dev_params,
559         .show_configfs_dev_params = fd_show_configfs_dev_params,
560         .get_device_rev         = fd_get_device_rev,
561         .get_device_type        = fd_get_device_type,
562         .get_blocks             = fd_get_blocks,
563 };
564
565 static int __init fileio_module_init(void)
566 {
567         return transport_subsystem_register(&fileio_template);
568 }
569
570 static void fileio_module_exit(void)
571 {
572         transport_subsystem_release(&fileio_template);
573 }
574
575 MODULE_DESCRIPTION("TCM FILEIO subsystem plugin");
576 MODULE_AUTHOR("nab@Linux-iSCSI.org");
577 MODULE_LICENSE("GPL");
578
579 module_init(fileio_module_init);
580 module_exit(fileio_module_exit);