2 * SCSI Block Commands (SBC) parsing and emulation.
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
9 * Nicholas A. Bellinger <nab@kernel.org>
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.
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.
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.
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>
32 #include <target/target_core_base.h>
33 #include <target/target_core_backend.h>
34 #include <target/target_core_fabric.h>
36 #include "target_core_internal.h"
37 #include "target_core_ua.h"
40 static int sbc_emulate_readcapacity(struct se_cmd
*cmd
)
42 struct se_device
*dev
= cmd
->se_dev
;
44 unsigned long long blocks_long
= dev
->transport
->get_blocks(dev
);
47 if (blocks_long
>= 0x00000000ffffffff)
50 blocks
= (u32
)blocks_long
;
52 buf
= transport_kmap_data_sg(cmd
);
54 buf
[0] = (blocks
>> 24) & 0xff;
55 buf
[1] = (blocks
>> 16) & 0xff;
56 buf
[2] = (blocks
>> 8) & 0xff;
57 buf
[3] = blocks
& 0xff;
58 buf
[4] = (dev
->se_sub_dev
->se_dev_attrib
.block_size
>> 24) & 0xff;
59 buf
[5] = (dev
->se_sub_dev
->se_dev_attrib
.block_size
>> 16) & 0xff;
60 buf
[6] = (dev
->se_sub_dev
->se_dev_attrib
.block_size
>> 8) & 0xff;
61 buf
[7] = dev
->se_sub_dev
->se_dev_attrib
.block_size
& 0xff;
63 transport_kunmap_data_sg(cmd
);
65 target_complete_cmd(cmd
, GOOD
);
69 static int sbc_emulate_readcapacity_16(struct se_cmd
*cmd
)
71 struct se_device
*dev
= cmd
->se_dev
;
73 unsigned long long blocks
= dev
->transport
->get_blocks(dev
);
75 buf
= transport_kmap_data_sg(cmd
);
77 buf
[0] = (blocks
>> 56) & 0xff;
78 buf
[1] = (blocks
>> 48) & 0xff;
79 buf
[2] = (blocks
>> 40) & 0xff;
80 buf
[3] = (blocks
>> 32) & 0xff;
81 buf
[4] = (blocks
>> 24) & 0xff;
82 buf
[5] = (blocks
>> 16) & 0xff;
83 buf
[6] = (blocks
>> 8) & 0xff;
84 buf
[7] = blocks
& 0xff;
85 buf
[8] = (dev
->se_sub_dev
->se_dev_attrib
.block_size
>> 24) & 0xff;
86 buf
[9] = (dev
->se_sub_dev
->se_dev_attrib
.block_size
>> 16) & 0xff;
87 buf
[10] = (dev
->se_sub_dev
->se_dev_attrib
.block_size
>> 8) & 0xff;
88 buf
[11] = dev
->se_sub_dev
->se_dev_attrib
.block_size
& 0xff;
90 * Set Thin Provisioning Enable bit following sbc3r22 in section
91 * READ CAPACITY (16) byte 14 if emulate_tpu or emulate_tpws is enabled.
93 if (dev
->se_sub_dev
->se_dev_attrib
.emulate_tpu
|| dev
->se_sub_dev
->se_dev_attrib
.emulate_tpws
)
96 transport_kunmap_data_sg(cmd
);
98 target_complete_cmd(cmd
, GOOD
);
103 * Used for TCM/IBLOCK and TCM/FILEIO for block/blk-lib.c level discard support.
104 * Note this is not used for TCM/pSCSI passthrough
106 static int sbc_emulate_unmap(struct se_cmd
*cmd
)
108 struct se_device
*dev
= cmd
->se_dev
;
109 unsigned char *buf
, *ptr
= NULL
;
110 unsigned char *cdb
= &cmd
->t_task_cdb
[0];
112 unsigned int size
= cmd
->data_length
, range
;
114 unsigned short dl
, bd_dl
;
116 if (!dev
->transport
->do_discard
) {
117 pr_err("UNMAP emulation not supported for: %s\n",
118 dev
->transport
->name
);
119 cmd
->scsi_sense_reason
= TCM_UNSUPPORTED_SCSI_OPCODE
;
123 /* First UNMAP block descriptor starts at 8 byte offset */
126 dl
= get_unaligned_be16(&cdb
[0]);
127 bd_dl
= get_unaligned_be16(&cdb
[2]);
129 buf
= transport_kmap_data_sg(cmd
);
132 pr_debug("UNMAP: Sub: %s Using dl: %hu bd_dl: %hu size: %hu"
133 " ptr: %p\n", dev
->transport
->name
, dl
, bd_dl
, size
, ptr
);
136 lba
= get_unaligned_be64(&ptr
[0]);
137 range
= get_unaligned_be32(&ptr
[8]);
138 pr_debug("UNMAP: Using lba: %llu and range: %u\n",
139 (unsigned long long)lba
, range
);
141 ret
= dev
->transport
->do_discard(dev
, lba
, range
);
143 pr_err("blkdev_issue_discard() failed: %d\n",
153 transport_kunmap_data_sg(cmd
);
155 target_complete_cmd(cmd
, GOOD
);
160 * Used for TCM/IBLOCK and TCM/FILEIO for block/blk-lib.c level discard support.
161 * Note this is not used for TCM/pSCSI passthrough
163 static int sbc_emulate_write_same(struct se_cmd
*cmd
)
165 struct se_device
*dev
= cmd
->se_dev
;
167 sector_t lba
= cmd
->t_task_lba
;
171 if (!dev
->transport
->do_discard
) {
172 pr_err("WRITE_SAME emulation not supported"
173 " for: %s\n", dev
->transport
->name
);
174 cmd
->scsi_sense_reason
= TCM_UNSUPPORTED_SCSI_OPCODE
;
178 if (cmd
->t_task_cdb
[0] == WRITE_SAME
)
179 num_blocks
= get_unaligned_be16(&cmd
->t_task_cdb
[7]);
180 else if (cmd
->t_task_cdb
[0] == WRITE_SAME_16
)
181 num_blocks
= get_unaligned_be32(&cmd
->t_task_cdb
[10]);
182 else /* WRITE_SAME_32 via VARIABLE_LENGTH_CMD */
183 num_blocks
= get_unaligned_be32(&cmd
->t_task_cdb
[28]);
186 * Use the explicit range when non zero is supplied, otherwise calculate
187 * the remaining range based on ->get_blocks() - starting LBA.
192 range
= (dev
->transport
->get_blocks(dev
) - lba
) + 1;
194 pr_debug("WRITE_SAME UNMAP: LBA: %llu Range: %llu\n",
195 (unsigned long long)lba
, (unsigned long long)range
);
197 ret
= dev
->transport
->do_discard(dev
, lba
, range
);
199 pr_debug("blkdev_issue_discard() failed for WRITE_SAME\n");
203 target_complete_cmd(cmd
, GOOD
);
207 static int sbc_emulate_verify(struct se_cmd
*cmd
)
209 target_complete_cmd(cmd
, GOOD
);
213 static inline u32
sbc_get_size(struct se_cmd
*cmd
, u32 sectors
)
215 return cmd
->se_dev
->se_sub_dev
->se_dev_attrib
.block_size
* sectors
;
218 static int sbc_check_valid_sectors(struct se_cmd
*cmd
)
220 struct se_device
*dev
= cmd
->se_dev
;
221 unsigned long long end_lba
;
224 sectors
= cmd
->data_length
/ dev
->se_sub_dev
->se_dev_attrib
.block_size
;
225 end_lba
= dev
->transport
->get_blocks(dev
) + 1;
227 if (cmd
->t_task_lba
+ sectors
> end_lba
) {
228 pr_err("target: lba %llu, sectors %u exceeds end lba %llu\n",
229 cmd
->t_task_lba
, sectors
, end_lba
);
236 static inline u32
transport_get_sectors_6(unsigned char *cdb
)
239 * Use 8-bit sector value. SBC-3 says:
241 * A TRANSFER LENGTH field set to zero specifies that 256
242 * logical blocks shall be written. Any other value
243 * specifies the number of logical blocks that shall be
246 return cdb
[4] ? : 256;
249 static inline u32
transport_get_sectors_10(unsigned char *cdb
)
251 return (u32
)(cdb
[7] << 8) + cdb
[8];
254 static inline u32
transport_get_sectors_12(unsigned char *cdb
)
256 return (u32
)(cdb
[6] << 24) + (cdb
[7] << 16) + (cdb
[8] << 8) + cdb
[9];
259 static inline u32
transport_get_sectors_16(unsigned char *cdb
)
261 return (u32
)(cdb
[10] << 24) + (cdb
[11] << 16) +
262 (cdb
[12] << 8) + cdb
[13];
266 * Used for VARIABLE_LENGTH_CDB WRITE_32 and READ_32 variants
268 static inline u32
transport_get_sectors_32(unsigned char *cdb
)
270 return (u32
)(cdb
[28] << 24) + (cdb
[29] << 16) +
271 (cdb
[30] << 8) + cdb
[31];
275 static inline u32
transport_lba_21(unsigned char *cdb
)
277 return ((cdb
[1] & 0x1f) << 16) | (cdb
[2] << 8) | cdb
[3];
280 static inline u32
transport_lba_32(unsigned char *cdb
)
282 return (cdb
[2] << 24) | (cdb
[3] << 16) | (cdb
[4] << 8) | cdb
[5];
285 static inline unsigned long long transport_lba_64(unsigned char *cdb
)
287 unsigned int __v1
, __v2
;
289 __v1
= (cdb
[2] << 24) | (cdb
[3] << 16) | (cdb
[4] << 8) | cdb
[5];
290 __v2
= (cdb
[6] << 24) | (cdb
[7] << 16) | (cdb
[8] << 8) | cdb
[9];
292 return ((unsigned long long)__v2
) | (unsigned long long)__v1
<< 32;
296 * For VARIABLE_LENGTH_CDB w/ 32 byte extended CDBs
298 static inline unsigned long long transport_lba_64_ext(unsigned char *cdb
)
300 unsigned int __v1
, __v2
;
302 __v1
= (cdb
[12] << 24) | (cdb
[13] << 16) | (cdb
[14] << 8) | cdb
[15];
303 __v2
= (cdb
[16] << 24) | (cdb
[17] << 16) | (cdb
[18] << 8) | cdb
[19];
305 return ((unsigned long long)__v2
) | (unsigned long long)__v1
<< 32;
308 static int sbc_write_same_supported(struct se_device
*dev
,
309 unsigned char *flags
)
311 if ((flags
[0] & 0x04) || (flags
[0] & 0x02)) {
312 pr_err("WRITE_SAME PBDATA and LBDATA"
313 " bits not supported for Block Discard"
319 * Currently for the emulated case we only accept
320 * tpws with the UNMAP=1 bit set.
322 if (!(flags
[0] & 0x08)) {
323 pr_err("WRITE_SAME w/o UNMAP bit not"
324 " supported for Block Discard Emulation\n");
331 static void xdreadwrite_callback(struct se_cmd
*cmd
)
333 unsigned char *buf
, *addr
;
334 struct scatterlist
*sg
;
339 * From sbc3r22.pdf section 5.48 XDWRITEREAD (10) command
341 * 1) read the specified logical block(s);
342 * 2) transfer logical blocks from the data-out buffer;
343 * 3) XOR the logical blocks transferred from the data-out buffer with
344 * the logical blocks read, storing the resulting XOR data in a buffer;
345 * 4) if the DISABLE WRITE bit is set to zero, then write the logical
346 * blocks transferred from the data-out buffer; and
347 * 5) transfer the resulting XOR data to the data-in buffer.
349 buf
= kmalloc(cmd
->data_length
, GFP_KERNEL
);
351 pr_err("Unable to allocate xor_callback buf\n");
355 * Copy the scatterlist WRITE buffer located at cmd->t_data_sg
356 * into the locally allocated *buf
358 sg_copy_to_buffer(cmd
->t_data_sg
,
364 * Now perform the XOR against the BIDI read memory located at
365 * cmd->t_mem_bidi_list
369 for_each_sg(cmd
->t_bidi_data_sg
, sg
, cmd
->t_bidi_data_nents
, count
) {
370 addr
= kmap_atomic(sg_page(sg
));
374 for (i
= 0; i
< sg
->length
; i
++)
375 *(addr
+ sg
->offset
+ i
) ^= *(buf
+ offset
+ i
);
377 offset
+= sg
->length
;
385 int sbc_parse_cdb(struct se_cmd
*cmd
, struct spc_ops
*ops
)
387 struct se_subsystem_dev
*su_dev
= cmd
->se_dev
->se_sub_dev
;
388 struct se_device
*dev
= cmd
->se_dev
;
389 unsigned char *cdb
= cmd
->t_task_cdb
;
396 sectors
= transport_get_sectors_6(cdb
);
397 cmd
->t_task_lba
= transport_lba_21(cdb
);
398 cmd
->se_cmd_flags
|= SCF_SCSI_DATA_CDB
;
399 cmd
->execute_cmd
= ops
->execute_rw
;
402 sectors
= transport_get_sectors_10(cdb
);
403 cmd
->t_task_lba
= transport_lba_32(cdb
);
404 cmd
->se_cmd_flags
|= SCF_SCSI_DATA_CDB
;
405 cmd
->execute_cmd
= ops
->execute_rw
;
408 sectors
= transport_get_sectors_12(cdb
);
409 cmd
->t_task_lba
= transport_lba_32(cdb
);
410 cmd
->se_cmd_flags
|= SCF_SCSI_DATA_CDB
;
411 cmd
->execute_cmd
= ops
->execute_rw
;
414 sectors
= transport_get_sectors_16(cdb
);
415 cmd
->t_task_lba
= transport_lba_64(cdb
);
416 cmd
->se_cmd_flags
|= SCF_SCSI_DATA_CDB
;
417 cmd
->execute_cmd
= ops
->execute_rw
;
420 sectors
= transport_get_sectors_6(cdb
);
421 cmd
->t_task_lba
= transport_lba_21(cdb
);
422 cmd
->se_cmd_flags
|= SCF_SCSI_DATA_CDB
;
423 cmd
->execute_cmd
= ops
->execute_rw
;
427 sectors
= transport_get_sectors_10(cdb
);
428 cmd
->t_task_lba
= transport_lba_32(cdb
);
430 cmd
->se_cmd_flags
|= SCF_FUA
;
431 cmd
->se_cmd_flags
|= SCF_SCSI_DATA_CDB
;
432 cmd
->execute_cmd
= ops
->execute_rw
;
435 sectors
= transport_get_sectors_12(cdb
);
436 cmd
->t_task_lba
= transport_lba_32(cdb
);
438 cmd
->se_cmd_flags
|= SCF_FUA
;
439 cmd
->se_cmd_flags
|= SCF_SCSI_DATA_CDB
;
440 cmd
->execute_cmd
= ops
->execute_rw
;
443 sectors
= transport_get_sectors_16(cdb
);
444 cmd
->t_task_lba
= transport_lba_64(cdb
);
446 cmd
->se_cmd_flags
|= SCF_FUA
;
447 cmd
->se_cmd_flags
|= SCF_SCSI_DATA_CDB
;
448 cmd
->execute_cmd
= ops
->execute_rw
;
451 if ((cmd
->data_direction
!= DMA_TO_DEVICE
) ||
452 !(cmd
->se_cmd_flags
& SCF_BIDI
))
453 goto out_invalid_cdb_field
;
454 sectors
= transport_get_sectors_10(cdb
);
456 cmd
->t_task_lba
= transport_lba_32(cdb
);
457 cmd
->se_cmd_flags
|= SCF_SCSI_DATA_CDB
;
460 * Setup BIDI XOR callback to be run after I/O completion.
462 cmd
->execute_cmd
= ops
->execute_rw
;
463 cmd
->transport_complete_callback
= &xdreadwrite_callback
;
465 cmd
->se_cmd_flags
|= SCF_FUA
;
467 case VARIABLE_LENGTH_CMD
:
469 u16 service_action
= get_unaligned_be16(&cdb
[8]);
470 switch (service_action
) {
472 sectors
= transport_get_sectors_32(cdb
);
475 * Use WRITE_32 and READ_32 opcodes for the emulated
476 * XDWRITE_READ_32 logic.
478 cmd
->t_task_lba
= transport_lba_64_ext(cdb
);
479 cmd
->se_cmd_flags
|= SCF_SCSI_DATA_CDB
;
482 * Setup BIDI XOR callback to be run during after I/O
485 cmd
->execute_cmd
= ops
->execute_rw
;
486 cmd
->transport_complete_callback
= &xdreadwrite_callback
;
488 cmd
->se_cmd_flags
|= SCF_FUA
;
491 sectors
= transport_get_sectors_32(cdb
);
493 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
495 goto out_invalid_cdb_field
;
498 size
= sbc_get_size(cmd
, 1);
499 cmd
->t_task_lba
= get_unaligned_be64(&cdb
[12]);
501 if (sbc_write_same_supported(dev
, &cdb
[10]) < 0)
502 goto out_unsupported_cdb
;
503 cmd
->execute_cmd
= sbc_emulate_write_same
;
506 pr_err("VARIABLE_LENGTH_CMD service action"
507 " 0x%04x not supported\n", service_action
);
508 goto out_unsupported_cdb
;
514 cmd
->execute_cmd
= sbc_emulate_readcapacity
;
516 case SERVICE_ACTION_IN
:
517 switch (cmd
->t_task_cdb
[1] & 0x1f) {
518 case SAI_READ_CAPACITY_16
:
519 cmd
->execute_cmd
= sbc_emulate_readcapacity_16
;
522 pr_err("Unsupported SA: 0x%02x\n",
523 cmd
->t_task_cdb
[1] & 0x1f);
524 goto out_invalid_cdb_field
;
526 size
= (cdb
[10] << 24) | (cdb
[11] << 16) |
527 (cdb
[12] << 8) | cdb
[13];
529 case SYNCHRONIZE_CACHE
:
530 case SYNCHRONIZE_CACHE_16
:
531 if (!ops
->execute_sync_cache
)
532 goto out_unsupported_cdb
;
535 * Extract LBA and range to be flushed for emulated SYNCHRONIZE_CACHE
537 if (cdb
[0] == SYNCHRONIZE_CACHE
) {
538 sectors
= transport_get_sectors_10(cdb
);
539 cmd
->t_task_lba
= transport_lba_32(cdb
);
541 sectors
= transport_get_sectors_16(cdb
);
542 cmd
->t_task_lba
= transport_lba_64(cdb
);
545 size
= sbc_get_size(cmd
, sectors
);
548 * Check to ensure that LBA + Range does not exceed past end of
549 * device for IBLOCK and FILEIO ->do_sync_cache() backend calls
551 if (cmd
->t_task_lba
|| sectors
) {
552 if (sbc_check_valid_sectors(cmd
) < 0)
553 goto out_invalid_cdb_field
;
555 cmd
->execute_cmd
= ops
->execute_sync_cache
;
558 size
= get_unaligned_be16(&cdb
[7]);
559 cmd
->execute_cmd
= sbc_emulate_unmap
;
562 sectors
= transport_get_sectors_16(cdb
);
564 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
565 goto out_invalid_cdb_field
;
568 size
= sbc_get_size(cmd
, 1);
569 cmd
->t_task_lba
= get_unaligned_be64(&cdb
[2]);
571 if (sbc_write_same_supported(dev
, &cdb
[1]) < 0)
572 goto out_unsupported_cdb
;
573 cmd
->execute_cmd
= sbc_emulate_write_same
;
576 sectors
= transport_get_sectors_10(cdb
);
578 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
579 goto out_invalid_cdb_field
;
582 size
= sbc_get_size(cmd
, 1);
583 cmd
->t_task_lba
= get_unaligned_be32(&cdb
[2]);
586 * Follow sbcr26 with WRITE_SAME (10) and check for the existence
587 * of byte 1 bit 3 UNMAP instead of original reserved field
589 if (sbc_write_same_supported(dev
, &cdb
[1]) < 0)
590 goto out_unsupported_cdb
;
591 cmd
->execute_cmd
= sbc_emulate_write_same
;
595 cmd
->execute_cmd
= sbc_emulate_verify
;
598 ret
= spc_parse_cdb(cmd
, &size
);
603 /* reject any command that we don't have a handler for */
604 if (!(cmd
->se_cmd_flags
& SCF_SCSI_DATA_CDB
) && !cmd
->execute_cmd
)
605 goto out_unsupported_cdb
;
607 if (cmd
->se_cmd_flags
& SCF_SCSI_DATA_CDB
) {
608 unsigned long long end_lba
;
610 if (sectors
> su_dev
->se_dev_attrib
.fabric_max_sectors
) {
611 printk_ratelimited(KERN_ERR
"SCSI OP %02xh with too"
612 " big sectors %u exceeds fabric_max_sectors:"
613 " %u\n", cdb
[0], sectors
,
614 su_dev
->se_dev_attrib
.fabric_max_sectors
);
615 goto out_invalid_cdb_field
;
617 if (sectors
> su_dev
->se_dev_attrib
.hw_max_sectors
) {
618 printk_ratelimited(KERN_ERR
"SCSI OP %02xh with too"
619 " big sectors %u exceeds backend hw_max_sectors:"
620 " %u\n", cdb
[0], sectors
,
621 su_dev
->se_dev_attrib
.hw_max_sectors
);
622 goto out_invalid_cdb_field
;
625 end_lba
= dev
->transport
->get_blocks(dev
) + 1;
626 if (cmd
->t_task_lba
+ sectors
> end_lba
) {
627 pr_err("cmd exceeds last lba %llu "
628 "(lba %llu, sectors %u)\n",
629 end_lba
, cmd
->t_task_lba
, sectors
);
630 goto out_invalid_cdb_field
;
633 size
= sbc_get_size(cmd
, sectors
);
636 ret
= target_cmd_size_check(cmd
, size
);
643 cmd
->se_cmd_flags
|= SCF_SCSI_CDB_EXCEPTION
;
644 cmd
->scsi_sense_reason
= TCM_UNSUPPORTED_SCSI_OPCODE
;
646 out_invalid_cdb_field
:
647 cmd
->se_cmd_flags
|= SCF_SCSI_CDB_EXCEPTION
;
648 cmd
->scsi_sense_reason
= TCM_INVALID_CDB_FIELD
;
651 EXPORT_SYMBOL(sbc_parse_cdb
);