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Merge branch 'for-rmk/virt/kvm/core' of git://git.kernel.org/pub/scm/linux/kernel...
[linux-2.6.git] / drivers / target / target_core_file.c
blobb9c88497e8f0d8c989a633bb23605e1f8e1dcff0
1 /*******************************************************************************
2 * Filename: target_core_file.c
3 *
4 * This file contains the Storage Engine <-> FILEIO transport specific functions
5 *
6 * (c) Copyright 2005-2012 RisingTide Systems LLC.
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 <scsi/scsi.h>
34 #include <scsi/scsi_host.h>
35
36 #include <target/target_core_base.h>
37 #include <target/target_core_backend.h>
38
39 #include "target_core_file.h"
40
41 static inline struct fd_dev *FD_DEV(struct se_device *dev)
42 {
43 return container_of(dev, struct fd_dev, dev);
44 }
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 struct se_device *fd_alloc_device(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->dev;
101 }
102
103 static int fd_configure_device(struct se_device *dev)
104 {
105 struct fd_dev *fd_dev = FD_DEV(dev);
106 struct fd_host *fd_host = dev->se_hba->hba_ptr;
107 struct file *file;
108 struct inode *inode = NULL;
109 int flags, ret = -EINVAL;
110
111 if (!(fd_dev->fbd_flags & FBDF_HAS_PATH)) {
112 pr_err("Missing fd_dev_name=\n");
113 return -EINVAL;
114 }
115
116 /*
117 * Use O_DSYNC by default instead of O_SYNC to forgo syncing
118 * of pure timestamp updates.
119 */
120 flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
121
122 /*
123 * Optionally allow fd_buffered_io=1 to be enabled for people
124 * who want use the fs buffer cache as an WriteCache mechanism.
125 *
126 * This means that in event of a hard failure, there is a risk
127 * of silent data-loss if the SCSI client has *not* performed a
128 * forced unit access (FUA) write, or issued SYNCHRONIZE_CACHE
129 * to write-out the entire device cache.
130 */
131 if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
132 pr_debug("FILEIO: Disabling O_DSYNC, using buffered FILEIO\n");
133 flags &= ~O_DSYNC;
134 }
135
136 file = filp_open(fd_dev->fd_dev_name, flags, 0600);
137 if (IS_ERR(file)) {
138 pr_err("filp_open(%s) failed\n", fd_dev->fd_dev_name);
139 ret = PTR_ERR(file);
140 goto fail;
141 }
142 fd_dev->fd_file = file;
143 /*
144 * If using a block backend with this struct file, we extract
145 * fd_dev->fd_[block,dev]_size from struct block_device.
146 *
147 * Otherwise, we use the passed fd_size= from configfs
148 */
149 inode = file->f_mapping->host;
150 if (S_ISBLK(inode->i_mode)) {
151 struct request_queue *q = bdev_get_queue(inode->i_bdev);
152 unsigned long long dev_size;
153
154 dev->dev_attrib.hw_block_size =
155 bdev_logical_block_size(inode->i_bdev);
156 dev->dev_attrib.hw_max_sectors = queue_max_hw_sectors(q);
157
158 /*
159 * Determine the number of bytes from i_size_read() minus
160 * one (1) logical sector from underlying struct block_device
161 */
162 dev_size = (i_size_read(file->f_mapping->host) -
163 fd_dev->fd_block_size);
164
165 pr_debug("FILEIO: Using size: %llu bytes from struct"
166 " block_device blocks: %llu logical_block_size: %d\n",
167 dev_size, div_u64(dev_size, fd_dev->fd_block_size),
168 fd_dev->fd_block_size);
169 } else {
170 if (!(fd_dev->fbd_flags & FBDF_HAS_SIZE)) {
171 pr_err("FILEIO: Missing fd_dev_size="
172 " parameter, and no backing struct"
173 " block_device\n");
174 goto fail;
175 }
176
177 dev->dev_attrib.hw_block_size = FD_BLOCKSIZE;
178 dev->dev_attrib.hw_max_sectors = FD_MAX_SECTORS;
179 }
180
181 fd_dev->fd_block_size = dev->dev_attrib.hw_block_size;
182
183 dev->dev_attrib.hw_queue_depth = FD_MAX_DEVICE_QUEUE_DEPTH;
184
185 if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
186 pr_debug("FILEIO: Forcing setting of emulate_write_cache=1"
187 " with FDBD_HAS_BUFFERED_IO_WCE\n");
188 dev->dev_attrib.emulate_write_cache = 1;
189 }
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 0;
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 ret;
205 }
206
207 static void fd_free_device(struct se_device *dev)
208 {
209 struct fd_dev *fd_dev = FD_DEV(dev);
210
211 if (fd_dev->fd_file) {
212 filp_close(fd_dev->fd_file, NULL);
213 fd_dev->fd_file = NULL;
214 }
215
216 kfree(fd_dev);
217 }
218
219 static int fd_do_rw(struct se_cmd *cmd, struct scatterlist *sgl,
220 u32 sgl_nents, int is_write)
221 {
222 struct se_device *se_dev = cmd->se_dev;
223 struct fd_dev *dev = FD_DEV(se_dev);
224 struct file *fd = dev->fd_file;
225 struct scatterlist *sg;
226 struct iovec *iov;
227 mm_segment_t old_fs;
228 loff_t pos = (cmd->t_task_lba * se_dev->dev_attrib.block_size);
229 int ret = 0, i;
230
231 iov = kzalloc(sizeof(struct iovec) * sgl_nents, GFP_KERNEL);
232 if (!iov) {
233 pr_err("Unable to allocate fd_do_readv iov[]\n");
234 return -ENOMEM;
235 }
236
237 for_each_sg(sgl, sg, sgl_nents, i) {
238 iov[i].iov_len = sg->length;
239 iov[i].iov_base = kmap(sg_page(sg)) + sg->offset;
240 }
241
242 old_fs = get_fs();
243 set_fs(get_ds());
244
245 if (is_write)
246 ret = vfs_writev(fd, &iov[0], sgl_nents, &pos);
247 else
248 ret = vfs_readv(fd, &iov[0], sgl_nents, &pos);
249
250 set_fs(old_fs);
251
252 for_each_sg(sgl, sg, sgl_nents, i)
253 kunmap(sg_page(sg));
254
255 kfree(iov);
256
257 if (is_write) {
258 if (ret < 0 || ret != cmd->data_length) {
259 pr_err("%s() write returned %d\n", __func__, ret);
260 return (ret < 0 ? ret : -EINVAL);
261 }
262 } else {
263 /*
264 * Return zeros and GOOD status even if the READ did not return
265 * the expected virt_size for struct file w/o a backing struct
266 * block_device.
267 */
268 if (S_ISBLK(fd->f_dentry->d_inode->i_mode)) {
269 if (ret < 0 || ret != cmd->data_length) {
270 pr_err("%s() returned %d, expecting %u for "
271 "S_ISBLK\n", __func__, ret,
272 cmd->data_length);
273 return (ret < 0 ? ret : -EINVAL);
274 }
275 } else {
276 if (ret < 0) {
277 pr_err("%s() returned %d for non S_ISBLK\n",
278 __func__, ret);
279 return ret;
280 }
281 }
282 }
283 return 1;
284 }
285
286 static sense_reason_t
287 fd_execute_sync_cache(struct se_cmd *cmd)
288 {
289 struct se_device *dev = cmd->se_dev;
290 struct fd_dev *fd_dev = FD_DEV(dev);
291 int immed = (cmd->t_task_cdb[1] & 0x2);
292 loff_t start, end;
293 int ret;
294
295 /*
296 * If the Immediate bit is set, queue up the GOOD response
297 * for this SYNCHRONIZE_CACHE op
298 */
299 if (immed)
300 target_complete_cmd(cmd, SAM_STAT_GOOD);
301
302 /*
303 * Determine if we will be flushing the entire device.
304 */
305 if (cmd->t_task_lba == 0 && cmd->data_length == 0) {
306 start = 0;
307 end = LLONG_MAX;
308 } else {
309 start = cmd->t_task_lba * dev->dev_attrib.block_size;
310 if (cmd->data_length)
311 end = start + cmd->data_length;
312 else
313 end = LLONG_MAX;
314 }
315
316 ret = vfs_fsync_range(fd_dev->fd_file, start, end, 1);
317 if (ret != 0)
318 pr_err("FILEIO: vfs_fsync_range() failed: %d\n", ret);
319
320 if (immed)
321 return 0;
322
323 if (ret)
324 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
325 else
326 target_complete_cmd(cmd, SAM_STAT_GOOD);
327
328 return 0;
329 }
330
331 static sense_reason_t
332 fd_execute_rw(struct se_cmd *cmd)
333 {
334 struct scatterlist *sgl = cmd->t_data_sg;
335 u32 sgl_nents = cmd->t_data_nents;
336 enum dma_data_direction data_direction = cmd->data_direction;
337 struct se_device *dev = cmd->se_dev;
338 int ret = 0;
339
340 /*
341 * Call vectorized fileio functions to map struct scatterlist
342 * physical memory addresses to struct iovec virtual memory.
343 */
344 if (data_direction == DMA_FROM_DEVICE) {
345 ret = fd_do_rw(cmd, sgl, sgl_nents, 0);
346 } else {
347 ret = fd_do_rw(cmd, sgl, sgl_nents, 1);
348 /*
349 * Perform implict vfs_fsync_range() for fd_do_writev() ops
350 * for SCSI WRITEs with Forced Unit Access (FUA) set.
351 * Allow this to happen independent of WCE=0 setting.
352 */
353 if (ret > 0 &&
354 dev->dev_attrib.emulate_fua_write > 0 &&
355 (cmd->se_cmd_flags & SCF_FUA)) {
356 struct fd_dev *fd_dev = FD_DEV(dev);
357 loff_t start = cmd->t_task_lba *
358 dev->dev_attrib.block_size;
359 loff_t end = start + cmd->data_length;
360
361 vfs_fsync_range(fd_dev->fd_file, start, end, 1);
362 }
363 }
364
365 if (ret < 0)
366 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
367
368 if (ret)
369 target_complete_cmd(cmd, SAM_STAT_GOOD);
370 return 0;
371 }
372
373 enum {
374 Opt_fd_dev_name, Opt_fd_dev_size, Opt_fd_buffered_io, Opt_err
375 };
376
377 static match_table_t tokens = {
378 {Opt_fd_dev_name, "fd_dev_name=%s"},
379 {Opt_fd_dev_size, "fd_dev_size=%s"},
380 {Opt_fd_buffered_io, "fd_buffered_io=%d"},
381 {Opt_err, NULL}
382 };
383
384 static ssize_t fd_set_configfs_dev_params(struct se_device *dev,
385 const char *page, ssize_t count)
386 {
387 struct fd_dev *fd_dev = FD_DEV(dev);
388 char *orig, *ptr, *arg_p, *opts;
389 substring_t args[MAX_OPT_ARGS];
390 int ret = 0, arg, token;
391
392 opts = kstrdup(page, GFP_KERNEL);
393 if (!opts)
394 return -ENOMEM;
395
396 orig = opts;
397
398 while ((ptr = strsep(&opts, ",\n")) != NULL) {
399 if (!*ptr)
400 continue;
401
402 token = match_token(ptr, tokens, args);
403 switch (token) {
404 case Opt_fd_dev_name:
405 if (match_strlcpy(fd_dev->fd_dev_name, &args[0],
406 FD_MAX_DEV_NAME) == 0) {
407 ret = -EINVAL;
408 break;
409 }
410 pr_debug("FILEIO: Referencing Path: %s\n",
411 fd_dev->fd_dev_name);
412 fd_dev->fbd_flags |= FBDF_HAS_PATH;
413 break;
414 case Opt_fd_dev_size:
415 arg_p = match_strdup(&args[0]);
416 if (!arg_p) {
417 ret = -ENOMEM;
418 break;
419 }
420 ret = strict_strtoull(arg_p, 0, &fd_dev->fd_dev_size);
421 kfree(arg_p);
422 if (ret < 0) {
423 pr_err("strict_strtoull() failed for"
424 " fd_dev_size=\n");
425 goto out;
426 }
427 pr_debug("FILEIO: Referencing Size: %llu"
428 " bytes\n", fd_dev->fd_dev_size);
429 fd_dev->fbd_flags |= FBDF_HAS_SIZE;
430 break;
431 case Opt_fd_buffered_io:
432 match_int(args, &arg);
433 if (arg != 1) {
434 pr_err("bogus fd_buffered_io=%d value\n", arg);
435 ret = -EINVAL;
436 goto out;
437 }
438
439 pr_debug("FILEIO: Using buffered I/O"
440 " operations for struct fd_dev\n");
441
442 fd_dev->fbd_flags |= FDBD_HAS_BUFFERED_IO_WCE;
443 break;
444 default:
445 break;
446 }
447 }
448
449 out:
450 kfree(orig);
451 return (!ret) ? count : ret;
452 }
453
454 static ssize_t fd_show_configfs_dev_params(struct se_device *dev, char *b)
455 {
456 struct fd_dev *fd_dev = FD_DEV(dev);
457 ssize_t bl = 0;
458
459 bl = sprintf(b + bl, "TCM FILEIO ID: %u", fd_dev->fd_dev_id);
460 bl += sprintf(b + bl, " File: %s Size: %llu Mode: %s\n",
461 fd_dev->fd_dev_name, fd_dev->fd_dev_size,
462 (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) ?
463 "Buffered-WCE" : "O_DSYNC");
464 return bl;
465 }
466
467 static sector_t fd_get_blocks(struct se_device *dev)
468 {
469 struct fd_dev *fd_dev = FD_DEV(dev);
470 struct file *f = fd_dev->fd_file;
471 struct inode *i = f->f_mapping->host;
472 unsigned long long dev_size;
473 /*
474 * When using a file that references an underlying struct block_device,
475 * ensure dev_size is always based on the current inode size in order
476 * to handle underlying block_device resize operations.
477 */
478 if (S_ISBLK(i->i_mode))
479 dev_size = (i_size_read(i) - fd_dev->fd_block_size);
480 else
481 dev_size = fd_dev->fd_dev_size;
482
483 return div_u64(dev_size, dev->dev_attrib.block_size);
484 }
485
486 static struct sbc_ops fd_sbc_ops = {
487 .execute_rw = fd_execute_rw,
488 .execute_sync_cache = fd_execute_sync_cache,
489 };
490
491 static sense_reason_t
492 fd_parse_cdb(struct se_cmd *cmd)
493 {
494 return sbc_parse_cdb(cmd, &fd_sbc_ops);
495 }
496
497 static struct se_subsystem_api fileio_template = {
498 .name = "fileio",
499 .inquiry_prod = "FILEIO",
500 .inquiry_rev = FD_VERSION,
501 .owner = THIS_MODULE,
502 .transport_type = TRANSPORT_PLUGIN_VHBA_PDEV,
503 .attach_hba = fd_attach_hba,
504 .detach_hba = fd_detach_hba,
505 .alloc_device = fd_alloc_device,
506 .configure_device = fd_configure_device,
507 .free_device = fd_free_device,
508 .parse_cdb = fd_parse_cdb,
509 .set_configfs_dev_params = fd_set_configfs_dev_params,
510 .show_configfs_dev_params = fd_show_configfs_dev_params,
511 .get_device_type = sbc_get_device_type,
512 .get_blocks = fd_get_blocks,
513 };
514
515 static int __init fileio_module_init(void)
516 {
517 return transport_subsystem_register(&fileio_template);
518 }
519
520 static void fileio_module_exit(void)
521 {
522 transport_subsystem_release(&fileio_template);
523 }
524
525 MODULE_DESCRIPTION("TCM FILEIO subsystem plugin");
526 MODULE_AUTHOR("nab@Linux-iSCSI.org");
527 MODULE_LICENSE("GPL");
528
529 module_init(fileio_module_init);
530 module_exit(fileio_module_exit);
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