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
);
102 int spc_get_write_same_sectors(struct se_cmd
*cmd
)
106 if (cmd
->t_task_cdb
[0] == WRITE_SAME
)
107 num_blocks
= get_unaligned_be16(&cmd
->t_task_cdb
[7]);
108 else if (cmd
->t_task_cdb
[0] == WRITE_SAME_16
)
109 num_blocks
= get_unaligned_be32(&cmd
->t_task_cdb
[10]);
110 else /* WRITE_SAME_32 via VARIABLE_LENGTH_CMD */
111 num_blocks
= get_unaligned_be32(&cmd
->t_task_cdb
[28]);
114 * Use the explicit range when non zero is supplied, otherwise calculate
115 * the remaining range based on ->get_blocks() - starting LBA.
120 return cmd
->se_dev
->transport
->get_blocks(cmd
->se_dev
) -
123 EXPORT_SYMBOL(spc_get_write_same_sectors
);
125 static int sbc_emulate_verify(struct se_cmd
*cmd
)
127 target_complete_cmd(cmd
, GOOD
);
131 static inline u32
sbc_get_size(struct se_cmd
*cmd
, u32 sectors
)
133 return cmd
->se_dev
->se_sub_dev
->se_dev_attrib
.block_size
* sectors
;
136 static int sbc_check_valid_sectors(struct se_cmd
*cmd
)
138 struct se_device
*dev
= cmd
->se_dev
;
139 unsigned long long end_lba
;
142 sectors
= cmd
->data_length
/ dev
->se_sub_dev
->se_dev_attrib
.block_size
;
143 end_lba
= dev
->transport
->get_blocks(dev
) + 1;
145 if (cmd
->t_task_lba
+ sectors
> end_lba
) {
146 pr_err("target: lba %llu, sectors %u exceeds end lba %llu\n",
147 cmd
->t_task_lba
, sectors
, end_lba
);
154 static inline u32
transport_get_sectors_6(unsigned char *cdb
)
157 * Use 8-bit sector value. SBC-3 says:
159 * A TRANSFER LENGTH field set to zero specifies that 256
160 * logical blocks shall be written. Any other value
161 * specifies the number of logical blocks that shall be
164 return cdb
[4] ? : 256;
167 static inline u32
transport_get_sectors_10(unsigned char *cdb
)
169 return (u32
)(cdb
[7] << 8) + cdb
[8];
172 static inline u32
transport_get_sectors_12(unsigned char *cdb
)
174 return (u32
)(cdb
[6] << 24) + (cdb
[7] << 16) + (cdb
[8] << 8) + cdb
[9];
177 static inline u32
transport_get_sectors_16(unsigned char *cdb
)
179 return (u32
)(cdb
[10] << 24) + (cdb
[11] << 16) +
180 (cdb
[12] << 8) + cdb
[13];
184 * Used for VARIABLE_LENGTH_CDB WRITE_32 and READ_32 variants
186 static inline u32
transport_get_sectors_32(unsigned char *cdb
)
188 return (u32
)(cdb
[28] << 24) + (cdb
[29] << 16) +
189 (cdb
[30] << 8) + cdb
[31];
193 static inline u32
transport_lba_21(unsigned char *cdb
)
195 return ((cdb
[1] & 0x1f) << 16) | (cdb
[2] << 8) | cdb
[3];
198 static inline u32
transport_lba_32(unsigned char *cdb
)
200 return (cdb
[2] << 24) | (cdb
[3] << 16) | (cdb
[4] << 8) | cdb
[5];
203 static inline unsigned long long transport_lba_64(unsigned char *cdb
)
205 unsigned int __v1
, __v2
;
207 __v1
= (cdb
[2] << 24) | (cdb
[3] << 16) | (cdb
[4] << 8) | cdb
[5];
208 __v2
= (cdb
[6] << 24) | (cdb
[7] << 16) | (cdb
[8] << 8) | cdb
[9];
210 return ((unsigned long long)__v2
) | (unsigned long long)__v1
<< 32;
214 * For VARIABLE_LENGTH_CDB w/ 32 byte extended CDBs
216 static inline unsigned long long transport_lba_64_ext(unsigned char *cdb
)
218 unsigned int __v1
, __v2
;
220 __v1
= (cdb
[12] << 24) | (cdb
[13] << 16) | (cdb
[14] << 8) | cdb
[15];
221 __v2
= (cdb
[16] << 24) | (cdb
[17] << 16) | (cdb
[18] << 8) | cdb
[19];
223 return ((unsigned long long)__v2
) | (unsigned long long)__v1
<< 32;
226 static int sbc_write_same_supported(struct se_device
*dev
,
227 unsigned char *flags
)
229 if ((flags
[0] & 0x04) || (flags
[0] & 0x02)) {
230 pr_err("WRITE_SAME PBDATA and LBDATA"
231 " bits not supported for Block Discard"
237 * Currently for the emulated case we only accept
238 * tpws with the UNMAP=1 bit set.
240 if (!(flags
[0] & 0x08)) {
241 pr_err("WRITE_SAME w/o UNMAP bit not"
242 " supported for Block Discard Emulation\n");
249 static void xdreadwrite_callback(struct se_cmd
*cmd
)
251 unsigned char *buf
, *addr
;
252 struct scatterlist
*sg
;
257 * From sbc3r22.pdf section 5.48 XDWRITEREAD (10) command
259 * 1) read the specified logical block(s);
260 * 2) transfer logical blocks from the data-out buffer;
261 * 3) XOR the logical blocks transferred from the data-out buffer with
262 * the logical blocks read, storing the resulting XOR data in a buffer;
263 * 4) if the DISABLE WRITE bit is set to zero, then write the logical
264 * blocks transferred from the data-out buffer; and
265 * 5) transfer the resulting XOR data to the data-in buffer.
267 buf
= kmalloc(cmd
->data_length
, GFP_KERNEL
);
269 pr_err("Unable to allocate xor_callback buf\n");
273 * Copy the scatterlist WRITE buffer located at cmd->t_data_sg
274 * into the locally allocated *buf
276 sg_copy_to_buffer(cmd
->t_data_sg
,
282 * Now perform the XOR against the BIDI read memory located at
283 * cmd->t_mem_bidi_list
287 for_each_sg(cmd
->t_bidi_data_sg
, sg
, cmd
->t_bidi_data_nents
, count
) {
288 addr
= kmap_atomic(sg_page(sg
));
292 for (i
= 0; i
< sg
->length
; i
++)
293 *(addr
+ sg
->offset
+ i
) ^= *(buf
+ offset
+ i
);
295 offset
+= sg
->length
;
303 int sbc_parse_cdb(struct se_cmd
*cmd
, struct spc_ops
*ops
)
305 struct se_subsystem_dev
*su_dev
= cmd
->se_dev
->se_sub_dev
;
306 struct se_device
*dev
= cmd
->se_dev
;
307 unsigned char *cdb
= cmd
->t_task_cdb
;
314 sectors
= transport_get_sectors_6(cdb
);
315 cmd
->t_task_lba
= transport_lba_21(cdb
);
316 cmd
->se_cmd_flags
|= SCF_SCSI_DATA_CDB
;
317 cmd
->execute_cmd
= ops
->execute_rw
;
320 sectors
= transport_get_sectors_10(cdb
);
321 cmd
->t_task_lba
= transport_lba_32(cdb
);
322 cmd
->se_cmd_flags
|= SCF_SCSI_DATA_CDB
;
323 cmd
->execute_cmd
= ops
->execute_rw
;
326 sectors
= transport_get_sectors_12(cdb
);
327 cmd
->t_task_lba
= transport_lba_32(cdb
);
328 cmd
->se_cmd_flags
|= SCF_SCSI_DATA_CDB
;
329 cmd
->execute_cmd
= ops
->execute_rw
;
332 sectors
= transport_get_sectors_16(cdb
);
333 cmd
->t_task_lba
= transport_lba_64(cdb
);
334 cmd
->se_cmd_flags
|= SCF_SCSI_DATA_CDB
;
335 cmd
->execute_cmd
= ops
->execute_rw
;
338 sectors
= transport_get_sectors_6(cdb
);
339 cmd
->t_task_lba
= transport_lba_21(cdb
);
340 cmd
->se_cmd_flags
|= SCF_SCSI_DATA_CDB
;
341 cmd
->execute_cmd
= ops
->execute_rw
;
345 sectors
= transport_get_sectors_10(cdb
);
346 cmd
->t_task_lba
= transport_lba_32(cdb
);
348 cmd
->se_cmd_flags
|= SCF_FUA
;
349 cmd
->se_cmd_flags
|= SCF_SCSI_DATA_CDB
;
350 cmd
->execute_cmd
= ops
->execute_rw
;
353 sectors
= transport_get_sectors_12(cdb
);
354 cmd
->t_task_lba
= transport_lba_32(cdb
);
356 cmd
->se_cmd_flags
|= SCF_FUA
;
357 cmd
->se_cmd_flags
|= SCF_SCSI_DATA_CDB
;
358 cmd
->execute_cmd
= ops
->execute_rw
;
361 sectors
= transport_get_sectors_16(cdb
);
362 cmd
->t_task_lba
= transport_lba_64(cdb
);
364 cmd
->se_cmd_flags
|= SCF_FUA
;
365 cmd
->se_cmd_flags
|= SCF_SCSI_DATA_CDB
;
366 cmd
->execute_cmd
= ops
->execute_rw
;
369 if ((cmd
->data_direction
!= DMA_TO_DEVICE
) ||
370 !(cmd
->se_cmd_flags
& SCF_BIDI
))
371 goto out_invalid_cdb_field
;
372 sectors
= transport_get_sectors_10(cdb
);
374 cmd
->t_task_lba
= transport_lba_32(cdb
);
375 cmd
->se_cmd_flags
|= SCF_SCSI_DATA_CDB
;
378 * Setup BIDI XOR callback to be run after I/O completion.
380 cmd
->execute_cmd
= ops
->execute_rw
;
381 cmd
->transport_complete_callback
= &xdreadwrite_callback
;
383 cmd
->se_cmd_flags
|= SCF_FUA
;
385 case VARIABLE_LENGTH_CMD
:
387 u16 service_action
= get_unaligned_be16(&cdb
[8]);
388 switch (service_action
) {
390 sectors
= transport_get_sectors_32(cdb
);
393 * Use WRITE_32 and READ_32 opcodes for the emulated
394 * XDWRITE_READ_32 logic.
396 cmd
->t_task_lba
= transport_lba_64_ext(cdb
);
397 cmd
->se_cmd_flags
|= SCF_SCSI_DATA_CDB
;
400 * Setup BIDI XOR callback to be run during after I/O
403 cmd
->execute_cmd
= ops
->execute_rw
;
404 cmd
->transport_complete_callback
= &xdreadwrite_callback
;
406 cmd
->se_cmd_flags
|= SCF_FUA
;
409 if (!ops
->execute_write_same
)
410 goto out_unsupported_cdb
;
412 sectors
= transport_get_sectors_32(cdb
);
414 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
416 goto out_invalid_cdb_field
;
419 size
= sbc_get_size(cmd
, 1);
420 cmd
->t_task_lba
= get_unaligned_be64(&cdb
[12]);
422 if (sbc_write_same_supported(dev
, &cdb
[10]) < 0)
423 goto out_unsupported_cdb
;
424 cmd
->execute_cmd
= ops
->execute_write_same
;
427 pr_err("VARIABLE_LENGTH_CMD service action"
428 " 0x%04x not supported\n", service_action
);
429 goto out_unsupported_cdb
;
435 cmd
->execute_cmd
= sbc_emulate_readcapacity
;
437 case SERVICE_ACTION_IN
:
438 switch (cmd
->t_task_cdb
[1] & 0x1f) {
439 case SAI_READ_CAPACITY_16
:
440 cmd
->execute_cmd
= sbc_emulate_readcapacity_16
;
443 pr_err("Unsupported SA: 0x%02x\n",
444 cmd
->t_task_cdb
[1] & 0x1f);
445 goto out_invalid_cdb_field
;
447 size
= (cdb
[10] << 24) | (cdb
[11] << 16) |
448 (cdb
[12] << 8) | cdb
[13];
450 case SYNCHRONIZE_CACHE
:
451 case SYNCHRONIZE_CACHE_16
:
452 if (!ops
->execute_sync_cache
)
453 goto out_unsupported_cdb
;
456 * Extract LBA and range to be flushed for emulated SYNCHRONIZE_CACHE
458 if (cdb
[0] == SYNCHRONIZE_CACHE
) {
459 sectors
= transport_get_sectors_10(cdb
);
460 cmd
->t_task_lba
= transport_lba_32(cdb
);
462 sectors
= transport_get_sectors_16(cdb
);
463 cmd
->t_task_lba
= transport_lba_64(cdb
);
466 size
= sbc_get_size(cmd
, sectors
);
469 * Check to ensure that LBA + Range does not exceed past end of
470 * device for IBLOCK and FILEIO ->do_sync_cache() backend calls
472 if (cmd
->t_task_lba
|| sectors
) {
473 if (sbc_check_valid_sectors(cmd
) < 0)
474 goto out_invalid_cdb_field
;
476 cmd
->execute_cmd
= ops
->execute_sync_cache
;
479 if (!ops
->execute_unmap
)
480 goto out_unsupported_cdb
;
482 size
= get_unaligned_be16(&cdb
[7]);
483 cmd
->execute_cmd
= ops
->execute_unmap
;
486 if (!ops
->execute_write_same
)
487 goto out_unsupported_cdb
;
489 sectors
= transport_get_sectors_16(cdb
);
491 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
492 goto out_invalid_cdb_field
;
495 size
= sbc_get_size(cmd
, 1);
496 cmd
->t_task_lba
= get_unaligned_be64(&cdb
[2]);
498 if (sbc_write_same_supported(dev
, &cdb
[1]) < 0)
499 goto out_unsupported_cdb
;
500 cmd
->execute_cmd
= ops
->execute_write_same
;
503 if (!ops
->execute_write_same
)
504 goto out_unsupported_cdb
;
506 sectors
= transport_get_sectors_10(cdb
);
508 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
509 goto out_invalid_cdb_field
;
512 size
= sbc_get_size(cmd
, 1);
513 cmd
->t_task_lba
= get_unaligned_be32(&cdb
[2]);
516 * Follow sbcr26 with WRITE_SAME (10) and check for the existence
517 * of byte 1 bit 3 UNMAP instead of original reserved field
519 if (sbc_write_same_supported(dev
, &cdb
[1]) < 0)
520 goto out_unsupported_cdb
;
521 cmd
->execute_cmd
= ops
->execute_write_same
;
525 cmd
->execute_cmd
= sbc_emulate_verify
;
528 ret
= spc_parse_cdb(cmd
, &size
);
533 /* reject any command that we don't have a handler for */
534 if (!(cmd
->se_cmd_flags
& SCF_SCSI_DATA_CDB
) && !cmd
->execute_cmd
)
535 goto out_unsupported_cdb
;
537 if (cmd
->se_cmd_flags
& SCF_SCSI_DATA_CDB
) {
538 unsigned long long end_lba
;
540 if (sectors
> su_dev
->se_dev_attrib
.fabric_max_sectors
) {
541 printk_ratelimited(KERN_ERR
"SCSI OP %02xh with too"
542 " big sectors %u exceeds fabric_max_sectors:"
543 " %u\n", cdb
[0], sectors
,
544 su_dev
->se_dev_attrib
.fabric_max_sectors
);
545 goto out_invalid_cdb_field
;
547 if (sectors
> su_dev
->se_dev_attrib
.hw_max_sectors
) {
548 printk_ratelimited(KERN_ERR
"SCSI OP %02xh with too"
549 " big sectors %u exceeds backend hw_max_sectors:"
550 " %u\n", cdb
[0], sectors
,
551 su_dev
->se_dev_attrib
.hw_max_sectors
);
552 goto out_invalid_cdb_field
;
555 end_lba
= dev
->transport
->get_blocks(dev
) + 1;
556 if (cmd
->t_task_lba
+ sectors
> end_lba
) {
557 pr_err("cmd exceeds last lba %llu "
558 "(lba %llu, sectors %u)\n",
559 end_lba
, cmd
->t_task_lba
, sectors
);
560 goto out_invalid_cdb_field
;
563 size
= sbc_get_size(cmd
, sectors
);
566 ret
= target_cmd_size_check(cmd
, size
);
573 cmd
->se_cmd_flags
|= SCF_SCSI_CDB_EXCEPTION
;
574 cmd
->scsi_sense_reason
= TCM_UNSUPPORTED_SCSI_OPCODE
;
576 out_invalid_cdb_field
:
577 cmd
->se_cmd_flags
|= SCF_SCSI_CDB_EXCEPTION
;
578 cmd
->scsi_sense_reason
= TCM_INVALID_CDB_FIELD
;
581 EXPORT_SYMBOL(sbc_parse_cdb
);