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docbook: networking: fix file paths for uapi headers
[linux-2.6/btrfs-unstable.git] / drivers / target / target_core_sbc.c
blob868f8aa04f13d318b1c752d08887703f7a72de21
1 /*
2 * SCSI Block Commands (SBC) parsing and emulation.
3 *
4 * Copyright (c) 2002, 2003, 2004, 2005 PyX Technologies, Inc.
5 * Copyright (c) 2005, 2006, 2007 SBE, Inc.
6 * Copyright (c) 2007-2010 Rising Tide Systems
7 * Copyright (c) 2008-2010 Linux-iSCSI.org
8 *
9 * Nicholas A. Bellinger <nab@kernel.org>
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
15 *
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
20 *
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
24 */
25
26 #include <linux/kernel.h>
27 #include <linux/module.h>
28 #include <linux/ratelimit.h>
29 #include <asm/unaligned.h>
30 #include <scsi/scsi.h>
31
32 #include <target/target_core_base.h>
33 #include <target/target_core_backend.h>
34 #include <target/target_core_fabric.h>
35
36 #include "target_core_internal.h"
37 #include "target_core_ua.h"
38
39
40 static int sbc_emulate_readcapacity(struct se_cmd *cmd)
41 {
42 struct se_device *dev = cmd->se_dev;
43 unsigned long long blocks_long = dev->transport->get_blocks(dev);
44 unsigned char *rbuf;
45 unsigned char buf[8];
46 u32 blocks;
47
48 if (blocks_long >= 0x00000000ffffffff)
49 blocks = 0xffffffff;
50 else
51 blocks = (u32)blocks_long;
52
53 buf[0] = (blocks >> 24) & 0xff;
54 buf[1] = (blocks >> 16) & 0xff;
55 buf[2] = (blocks >> 8) & 0xff;
56 buf[3] = blocks & 0xff;
57 buf[4] = (dev->se_sub_dev->se_dev_attrib.block_size >> 24) & 0xff;
58 buf[5] = (dev->se_sub_dev->se_dev_attrib.block_size >> 16) & 0xff;
59 buf[6] = (dev->se_sub_dev->se_dev_attrib.block_size >> 8) & 0xff;
60 buf[7] = dev->se_sub_dev->se_dev_attrib.block_size & 0xff;
61
62 rbuf = transport_kmap_data_sg(cmd);
63 if (rbuf) {
64 memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
65 transport_kunmap_data_sg(cmd);
66 }
67
68 target_complete_cmd(cmd, GOOD);
69 return 0;
70 }
71
72 static int sbc_emulate_readcapacity_16(struct se_cmd *cmd)
73 {
74 struct se_device *dev = cmd->se_dev;
75 unsigned char *rbuf;
76 unsigned char buf[32];
77 unsigned long long blocks = dev->transport->get_blocks(dev);
78
79 memset(buf, 0, sizeof(buf));
80 buf[0] = (blocks >> 56) & 0xff;
81 buf[1] = (blocks >> 48) & 0xff;
82 buf[2] = (blocks >> 40) & 0xff;
83 buf[3] = (blocks >> 32) & 0xff;
84 buf[4] = (blocks >> 24) & 0xff;
85 buf[5] = (blocks >> 16) & 0xff;
86 buf[6] = (blocks >> 8) & 0xff;
87 buf[7] = blocks & 0xff;
88 buf[8] = (dev->se_sub_dev->se_dev_attrib.block_size >> 24) & 0xff;
89 buf[9] = (dev->se_sub_dev->se_dev_attrib.block_size >> 16) & 0xff;
90 buf[10] = (dev->se_sub_dev->se_dev_attrib.block_size >> 8) & 0xff;
91 buf[11] = dev->se_sub_dev->se_dev_attrib.block_size & 0xff;
92 /*
93 * Set Thin Provisioning Enable bit following sbc3r22 in section
94 * READ CAPACITY (16) byte 14 if emulate_tpu or emulate_tpws is enabled.
95 */
96 if (dev->se_sub_dev->se_dev_attrib.emulate_tpu || dev->se_sub_dev->se_dev_attrib.emulate_tpws)
97 buf[14] = 0x80;
98
99 rbuf = transport_kmap_data_sg(cmd);
100 if (rbuf) {
101 memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
102 transport_kunmap_data_sg(cmd);
103 }
104
105 target_complete_cmd(cmd, GOOD);
106 return 0;
107 }
108
109 int spc_get_write_same_sectors(struct se_cmd *cmd)
110 {
111 u32 num_blocks;
112
113 if (cmd->t_task_cdb[0] == WRITE_SAME)
114 num_blocks = get_unaligned_be16(&cmd->t_task_cdb[7]);
115 else if (cmd->t_task_cdb[0] == WRITE_SAME_16)
116 num_blocks = get_unaligned_be32(&cmd->t_task_cdb[10]);
117 else /* WRITE_SAME_32 via VARIABLE_LENGTH_CMD */
118 num_blocks = get_unaligned_be32(&cmd->t_task_cdb[28]);
119
120 /*
121 * Use the explicit range when non zero is supplied, otherwise calculate
122 * the remaining range based on ->get_blocks() - starting LBA.
123 */
124 if (num_blocks)
125 return num_blocks;
126
127 return cmd->se_dev->transport->get_blocks(cmd->se_dev) -
128 cmd->t_task_lba + 1;
129 }
130 EXPORT_SYMBOL(spc_get_write_same_sectors);
131
132 static int sbc_emulate_verify(struct se_cmd *cmd)
133 {
134 target_complete_cmd(cmd, GOOD);
135 return 0;
136 }
137
138 static inline u32 sbc_get_size(struct se_cmd *cmd, u32 sectors)
139 {
140 return cmd->se_dev->se_sub_dev->se_dev_attrib.block_size * sectors;
141 }
142
143 static int sbc_check_valid_sectors(struct se_cmd *cmd)
144 {
145 struct se_device *dev = cmd->se_dev;
146 unsigned long long end_lba;
147 u32 sectors;
148
149 sectors = cmd->data_length / dev->se_sub_dev->se_dev_attrib.block_size;
150 end_lba = dev->transport->get_blocks(dev) + 1;
151
152 if (cmd->t_task_lba + sectors > end_lba) {
153 pr_err("target: lba %llu, sectors %u exceeds end lba %llu\n",
154 cmd->t_task_lba, sectors, end_lba);
155 return -EINVAL;
156 }
157
158 return 0;
159 }
160
161 static inline u32 transport_get_sectors_6(unsigned char *cdb)
162 {
163 /*
164 * Use 8-bit sector value. SBC-3 says:
165 *
166 * A TRANSFER LENGTH field set to zero specifies that 256
167 * logical blocks shall be written. Any other value
168 * specifies the number of logical blocks that shall be
169 * written.
170 */
171 return cdb[4] ? : 256;
172 }
173
174 static inline u32 transport_get_sectors_10(unsigned char *cdb)
175 {
176 return (u32)(cdb[7] << 8) + cdb[8];
177 }
178
179 static inline u32 transport_get_sectors_12(unsigned char *cdb)
180 {
181 return (u32)(cdb[6] << 24) + (cdb[7] << 16) + (cdb[8] << 8) + cdb[9];
182 }
183
184 static inline u32 transport_get_sectors_16(unsigned char *cdb)
185 {
186 return (u32)(cdb[10] << 24) + (cdb[11] << 16) +
187 (cdb[12] << 8) + cdb[13];
188 }
189
190 /*
191 * Used for VARIABLE_LENGTH_CDB WRITE_32 and READ_32 variants
192 */
193 static inline u32 transport_get_sectors_32(unsigned char *cdb)
194 {
195 return (u32)(cdb[28] << 24) + (cdb[29] << 16) +
196 (cdb[30] << 8) + cdb[31];
197
198 }
199
200 static inline u32 transport_lba_21(unsigned char *cdb)
201 {
202 return ((cdb[1] & 0x1f) << 16) | (cdb[2] << 8) | cdb[3];
203 }
204
205 static inline u32 transport_lba_32(unsigned char *cdb)
206 {
207 return (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
208 }
209
210 static inline unsigned long long transport_lba_64(unsigned char *cdb)
211 {
212 unsigned int __v1, __v2;
213
214 __v1 = (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
215 __v2 = (cdb[6] << 24) | (cdb[7] << 16) | (cdb[8] << 8) | cdb[9];
216
217 return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
218 }
219
220 /*
221 * For VARIABLE_LENGTH_CDB w/ 32 byte extended CDBs
222 */
223 static inline unsigned long long transport_lba_64_ext(unsigned char *cdb)
224 {
225 unsigned int __v1, __v2;
226
227 __v1 = (cdb[12] << 24) | (cdb[13] << 16) | (cdb[14] << 8) | cdb[15];
228 __v2 = (cdb[16] << 24) | (cdb[17] << 16) | (cdb[18] << 8) | cdb[19];
229
230 return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
231 }
232
233 static int sbc_write_same_supported(struct se_device *dev,
234 unsigned char *flags)
235 {
236 if ((flags[0] & 0x04) || (flags[0] & 0x02)) {
237 pr_err("WRITE_SAME PBDATA and LBDATA"
238 " bits not supported for Block Discard"
239 " Emulation\n");
240 return -ENOSYS;
241 }
242
243 /*
244 * Currently for the emulated case we only accept
245 * tpws with the UNMAP=1 bit set.
246 */
247 if (!(flags[0] & 0x08)) {
248 pr_err("WRITE_SAME w/o UNMAP bit not"
249 " supported for Block Discard Emulation\n");
250 return -ENOSYS;
251 }
252
253 return 0;
254 }
255
256 static void xdreadwrite_callback(struct se_cmd *cmd)
257 {
258 unsigned char *buf, *addr;
259 struct scatterlist *sg;
260 unsigned int offset;
261 int i;
262 int count;
263 /*
264 * From sbc3r22.pdf section 5.48 XDWRITEREAD (10) command
265 *
266 * 1) read the specified logical block(s);
267 * 2) transfer logical blocks from the data-out buffer;
268 * 3) XOR the logical blocks transferred from the data-out buffer with
269 * the logical blocks read, storing the resulting XOR data in a buffer;
270 * 4) if the DISABLE WRITE bit is set to zero, then write the logical
271 * blocks transferred from the data-out buffer; and
272 * 5) transfer the resulting XOR data to the data-in buffer.
273 */
274 buf = kmalloc(cmd->data_length, GFP_KERNEL);
275 if (!buf) {
276 pr_err("Unable to allocate xor_callback buf\n");
277 return;
278 }
279 /*
280 * Copy the scatterlist WRITE buffer located at cmd->t_data_sg
281 * into the locally allocated *buf
282 */
283 sg_copy_to_buffer(cmd->t_data_sg,
284 cmd->t_data_nents,
285 buf,
286 cmd->data_length);
287
288 /*
289 * Now perform the XOR against the BIDI read memory located at
290 * cmd->t_mem_bidi_list
291 */
292
293 offset = 0;
294 for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, count) {
295 addr = kmap_atomic(sg_page(sg));
296 if (!addr)
297 goto out;
298
299 for (i = 0; i < sg->length; i++)
300 *(addr + sg->offset + i) ^= *(buf + offset + i);
301
302 offset += sg->length;
303 kunmap_atomic(addr);
304 }
305
306 out:
307 kfree(buf);
308 }
309
310 int sbc_parse_cdb(struct se_cmd *cmd, struct spc_ops *ops)
311 {
312 struct se_subsystem_dev *su_dev = cmd->se_dev->se_sub_dev;
313 struct se_device *dev = cmd->se_dev;
314 unsigned char *cdb = cmd->t_task_cdb;
315 unsigned int size;
316 u32 sectors = 0;
317 int ret;
318
319 switch (cdb[0]) {
320 case READ_6:
321 sectors = transport_get_sectors_6(cdb);
322 cmd->t_task_lba = transport_lba_21(cdb);
323 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
324 cmd->execute_cmd = ops->execute_rw;
325 break;
326 case READ_10:
327 sectors = transport_get_sectors_10(cdb);
328 cmd->t_task_lba = transport_lba_32(cdb);
329 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
330 cmd->execute_cmd = ops->execute_rw;
331 break;
332 case READ_12:
333 sectors = transport_get_sectors_12(cdb);
334 cmd->t_task_lba = transport_lba_32(cdb);
335 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
336 cmd->execute_cmd = ops->execute_rw;
337 break;
338 case READ_16:
339 sectors = transport_get_sectors_16(cdb);
340 cmd->t_task_lba = transport_lba_64(cdb);
341 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
342 cmd->execute_cmd = ops->execute_rw;
343 break;
344 case WRITE_6:
345 sectors = transport_get_sectors_6(cdb);
346 cmd->t_task_lba = transport_lba_21(cdb);
347 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
348 cmd->execute_cmd = ops->execute_rw;
349 break;
350 case WRITE_10:
351 case WRITE_VERIFY:
352 sectors = transport_get_sectors_10(cdb);
353 cmd->t_task_lba = transport_lba_32(cdb);
354 if (cdb[1] & 0x8)
355 cmd->se_cmd_flags |= SCF_FUA;
356 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
357 cmd->execute_cmd = ops->execute_rw;
358 break;
359 case WRITE_12:
360 sectors = transport_get_sectors_12(cdb);
361 cmd->t_task_lba = transport_lba_32(cdb);
362 if (cdb[1] & 0x8)
363 cmd->se_cmd_flags |= SCF_FUA;
364 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
365 cmd->execute_cmd = ops->execute_rw;
366 break;
367 case WRITE_16:
368 sectors = transport_get_sectors_16(cdb);
369 cmd->t_task_lba = transport_lba_64(cdb);
370 if (cdb[1] & 0x8)
371 cmd->se_cmd_flags |= SCF_FUA;
372 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
373 cmd->execute_cmd = ops->execute_rw;
374 break;
375 case XDWRITEREAD_10:
376 if ((cmd->data_direction != DMA_TO_DEVICE) ||
377 !(cmd->se_cmd_flags & SCF_BIDI))
378 goto out_invalid_cdb_field;
379 sectors = transport_get_sectors_10(cdb);
380
381 cmd->t_task_lba = transport_lba_32(cdb);
382 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
383
384 /*
385 * Setup BIDI XOR callback to be run after I/O completion.
386 */
387 cmd->execute_cmd = ops->execute_rw;
388 cmd->transport_complete_callback = &xdreadwrite_callback;
389 if (cdb[1] & 0x8)
390 cmd->se_cmd_flags |= SCF_FUA;
391 break;
392 case VARIABLE_LENGTH_CMD:
393 {
394 u16 service_action = get_unaligned_be16(&cdb[8]);
395 switch (service_action) {
396 case XDWRITEREAD_32:
397 sectors = transport_get_sectors_32(cdb);
398
399 /*
400 * Use WRITE_32 and READ_32 opcodes for the emulated
401 * XDWRITE_READ_32 logic.
402 */
403 cmd->t_task_lba = transport_lba_64_ext(cdb);
404 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
405
406 /*
407 * Setup BIDI XOR callback to be run during after I/O
408 * completion.
409 */
410 cmd->execute_cmd = ops->execute_rw;
411 cmd->transport_complete_callback = &xdreadwrite_callback;
412 if (cdb[1] & 0x8)
413 cmd->se_cmd_flags |= SCF_FUA;
414 break;
415 case WRITE_SAME_32:
416 if (!ops->execute_write_same)
417 goto out_unsupported_cdb;
418
419 sectors = transport_get_sectors_32(cdb);
420 if (!sectors) {
421 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
422 " supported\n");
423 goto out_invalid_cdb_field;
424 }
425
426 size = sbc_get_size(cmd, 1);
427 cmd->t_task_lba = get_unaligned_be64(&cdb[12]);
428
429 if (sbc_write_same_supported(dev, &cdb[10]) < 0)
430 goto out_unsupported_cdb;
431 cmd->execute_cmd = ops->execute_write_same;
432 break;
433 default:
434 pr_err("VARIABLE_LENGTH_CMD service action"
435 " 0x%04x not supported\n", service_action);
436 goto out_unsupported_cdb;
437 }
438 break;
439 }
440 case READ_CAPACITY:
441 size = READ_CAP_LEN;
442 cmd->execute_cmd = sbc_emulate_readcapacity;
443 break;
444 case SERVICE_ACTION_IN:
445 switch (cmd->t_task_cdb[1] & 0x1f) {
446 case SAI_READ_CAPACITY_16:
447 cmd->execute_cmd = sbc_emulate_readcapacity_16;
448 break;
449 default:
450 pr_err("Unsupported SA: 0x%02x\n",
451 cmd->t_task_cdb[1] & 0x1f);
452 goto out_invalid_cdb_field;
453 }
454 size = (cdb[10] << 24) | (cdb[11] << 16) |
455 (cdb[12] << 8) | cdb[13];
456 break;
457 case SYNCHRONIZE_CACHE:
458 case SYNCHRONIZE_CACHE_16:
459 if (!ops->execute_sync_cache)
460 goto out_unsupported_cdb;
461
462 /*
463 * Extract LBA and range to be flushed for emulated SYNCHRONIZE_CACHE
464 */
465 if (cdb[0] == SYNCHRONIZE_CACHE) {
466 sectors = transport_get_sectors_10(cdb);
467 cmd->t_task_lba = transport_lba_32(cdb);
468 } else {
469 sectors = transport_get_sectors_16(cdb);
470 cmd->t_task_lba = transport_lba_64(cdb);
471 }
472
473 size = sbc_get_size(cmd, sectors);
474
475 /*
476 * Check to ensure that LBA + Range does not exceed past end of
477 * device for IBLOCK and FILEIO ->do_sync_cache() backend calls
478 */
479 if (cmd->t_task_lba || sectors) {
480 if (sbc_check_valid_sectors(cmd) < 0)
481 goto out_invalid_cdb_field;
482 }
483 cmd->execute_cmd = ops->execute_sync_cache;
484 break;
485 case UNMAP:
486 if (!ops->execute_unmap)
487 goto out_unsupported_cdb;
488
489 size = get_unaligned_be16(&cdb[7]);
490 cmd->execute_cmd = ops->execute_unmap;
491 break;
492 case WRITE_SAME_16:
493 if (!ops->execute_write_same)
494 goto out_unsupported_cdb;
495
496 sectors = transport_get_sectors_16(cdb);
497 if (!sectors) {
498 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
499 goto out_invalid_cdb_field;
500 }
501
502 size = sbc_get_size(cmd, 1);
503 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
504
505 if (sbc_write_same_supported(dev, &cdb[1]) < 0)
506 goto out_unsupported_cdb;
507 cmd->execute_cmd = ops->execute_write_same;
508 break;
509 case WRITE_SAME:
510 if (!ops->execute_write_same)
511 goto out_unsupported_cdb;
512
513 sectors = transport_get_sectors_10(cdb);
514 if (!sectors) {
515 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
516 goto out_invalid_cdb_field;
517 }
518
519 size = sbc_get_size(cmd, 1);
520 cmd->t_task_lba = get_unaligned_be32(&cdb[2]);
521
522 /*
523 * Follow sbcr26 with WRITE_SAME (10) and check for the existence
524 * of byte 1 bit 3 UNMAP instead of original reserved field
525 */
526 if (sbc_write_same_supported(dev, &cdb[1]) < 0)
527 goto out_unsupported_cdb;
528 cmd->execute_cmd = ops->execute_write_same;
529 break;
530 case VERIFY:
531 size = 0;
532 cmd->execute_cmd = sbc_emulate_verify;
533 break;
534 default:
535 ret = spc_parse_cdb(cmd, &size);
536 if (ret)
537 return ret;
538 }
539
540 /* reject any command that we don't have a handler for */
541 if (!(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) && !cmd->execute_cmd)
542 goto out_unsupported_cdb;
543
544 if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
545 unsigned long long end_lba;
546
547 if (sectors > su_dev->se_dev_attrib.fabric_max_sectors) {
548 printk_ratelimited(KERN_ERR "SCSI OP %02xh with too"
549 " big sectors %u exceeds fabric_max_sectors:"
550 " %u\n", cdb[0], sectors,
551 su_dev->se_dev_attrib.fabric_max_sectors);
552 goto out_invalid_cdb_field;
553 }
554 if (sectors > su_dev->se_dev_attrib.hw_max_sectors) {
555 printk_ratelimited(KERN_ERR "SCSI OP %02xh with too"
556 " big sectors %u exceeds backend hw_max_sectors:"
557 " %u\n", cdb[0], sectors,
558 su_dev->se_dev_attrib.hw_max_sectors);
559 goto out_invalid_cdb_field;
560 }
561
562 end_lba = dev->transport->get_blocks(dev) + 1;
563 if (cmd->t_task_lba + sectors > end_lba) {
564 pr_err("cmd exceeds last lba %llu "
565 "(lba %llu, sectors %u)\n",
566 end_lba, cmd->t_task_lba, sectors);
567 goto out_invalid_cdb_field;
568 }
569
570 size = sbc_get_size(cmd, sectors);
571 }
572
573 ret = target_cmd_size_check(cmd, size);
574 if (ret < 0)
575 return ret;
576
577 return 0;
578
579 out_unsupported_cdb:
580 cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
581 cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
582 return -EINVAL;
583 out_invalid_cdb_field:
584 cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
585 cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
586 return -EINVAL;
587 }
588 EXPORT_SYMBOL(sbc_parse_cdb);
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