2 * SCSI Block Commands (SBC) parsing and emulation.
4 * (c) Copyright 2002-2012 RisingTide Systems LLC.
6 * Nicholas A. Bellinger <nab@kernel.org>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
23 #include <linux/kernel.h>
24 #include <linux/module.h>
25 #include <linux/ratelimit.h>
26 #include <asm/unaligned.h>
27 #include <scsi/scsi.h>
29 #include <target/target_core_base.h>
30 #include <target/target_core_backend.h>
31 #include <target/target_core_fabric.h>
33 #include "target_core_internal.h"
34 #include "target_core_ua.h"
38 sbc_emulate_readcapacity(struct se_cmd
*cmd
)
40 struct se_device
*dev
= cmd
->se_dev
;
41 unsigned long long blocks_long
= dev
->transport
->get_blocks(dev
);
46 if (blocks_long
>= 0x00000000ffffffff)
49 blocks
= (u32
)blocks_long
;
51 buf
[0] = (blocks
>> 24) & 0xff;
52 buf
[1] = (blocks
>> 16) & 0xff;
53 buf
[2] = (blocks
>> 8) & 0xff;
54 buf
[3] = blocks
& 0xff;
55 buf
[4] = (dev
->dev_attrib
.block_size
>> 24) & 0xff;
56 buf
[5] = (dev
->dev_attrib
.block_size
>> 16) & 0xff;
57 buf
[6] = (dev
->dev_attrib
.block_size
>> 8) & 0xff;
58 buf
[7] = dev
->dev_attrib
.block_size
& 0xff;
60 rbuf
= transport_kmap_data_sg(cmd
);
62 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE
;
64 memcpy(rbuf
, buf
, min_t(u32
, sizeof(buf
), cmd
->data_length
));
65 transport_kunmap_data_sg(cmd
);
67 target_complete_cmd(cmd
, GOOD
);
72 sbc_emulate_readcapacity_16(struct se_cmd
*cmd
)
74 struct se_device
*dev
= cmd
->se_dev
;
76 unsigned char buf
[32];
77 unsigned long long blocks
= dev
->transport
->get_blocks(dev
);
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
->dev_attrib
.block_size
>> 24) & 0xff;
89 buf
[9] = (dev
->dev_attrib
.block_size
>> 16) & 0xff;
90 buf
[10] = (dev
->dev_attrib
.block_size
>> 8) & 0xff;
91 buf
[11] = dev
->dev_attrib
.block_size
& 0xff;
93 * Set Thin Provisioning Enable bit following sbc3r22 in section
94 * READ CAPACITY (16) byte 14 if emulate_tpu or emulate_tpws is enabled.
96 if (dev
->dev_attrib
.emulate_tpu
|| dev
->dev_attrib
.emulate_tpws
)
99 rbuf
= transport_kmap_data_sg(cmd
);
101 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE
;
103 memcpy(rbuf
, buf
, min_t(u32
, sizeof(buf
), cmd
->data_length
));
104 transport_kunmap_data_sg(cmd
);
106 target_complete_cmd(cmd
, GOOD
);
110 sector_t
spc_get_write_same_sectors(struct se_cmd
*cmd
)
114 if (cmd
->t_task_cdb
[0] == WRITE_SAME
)
115 num_blocks
= get_unaligned_be16(&cmd
->t_task_cdb
[7]);
116 else if (cmd
->t_task_cdb
[0] == WRITE_SAME_16
)
117 num_blocks
= get_unaligned_be32(&cmd
->t_task_cdb
[10]);
118 else /* WRITE_SAME_32 via VARIABLE_LENGTH_CMD */
119 num_blocks
= get_unaligned_be32(&cmd
->t_task_cdb
[28]);
122 * Use the explicit range when non zero is supplied, otherwise calculate
123 * the remaining range based on ->get_blocks() - starting LBA.
128 return cmd
->se_dev
->transport
->get_blocks(cmd
->se_dev
) -
131 EXPORT_SYMBOL(spc_get_write_same_sectors
);
133 static sense_reason_t
134 sbc_emulate_noop(struct se_cmd
*cmd
)
136 target_complete_cmd(cmd
, GOOD
);
140 static inline u32
sbc_get_size(struct se_cmd
*cmd
, u32 sectors
)
142 return cmd
->se_dev
->dev_attrib
.block_size
* sectors
;
145 static int sbc_check_valid_sectors(struct se_cmd
*cmd
)
147 struct se_device
*dev
= cmd
->se_dev
;
148 unsigned long long end_lba
;
151 sectors
= cmd
->data_length
/ dev
->dev_attrib
.block_size
;
152 end_lba
= dev
->transport
->get_blocks(dev
) + 1;
154 if (cmd
->t_task_lba
+ sectors
> end_lba
) {
155 pr_err("target: lba %llu, sectors %u exceeds end lba %llu\n",
156 cmd
->t_task_lba
, sectors
, end_lba
);
163 static inline u32
transport_get_sectors_6(unsigned char *cdb
)
166 * Use 8-bit sector value. SBC-3 says:
168 * A TRANSFER LENGTH field set to zero specifies that 256
169 * logical blocks shall be written. Any other value
170 * specifies the number of logical blocks that shall be
173 return cdb
[4] ? : 256;
176 static inline u32
transport_get_sectors_10(unsigned char *cdb
)
178 return (u32
)(cdb
[7] << 8) + cdb
[8];
181 static inline u32
transport_get_sectors_12(unsigned char *cdb
)
183 return (u32
)(cdb
[6] << 24) + (cdb
[7] << 16) + (cdb
[8] << 8) + cdb
[9];
186 static inline u32
transport_get_sectors_16(unsigned char *cdb
)
188 return (u32
)(cdb
[10] << 24) + (cdb
[11] << 16) +
189 (cdb
[12] << 8) + cdb
[13];
193 * Used for VARIABLE_LENGTH_CDB WRITE_32 and READ_32 variants
195 static inline u32
transport_get_sectors_32(unsigned char *cdb
)
197 return (u32
)(cdb
[28] << 24) + (cdb
[29] << 16) +
198 (cdb
[30] << 8) + cdb
[31];
202 static inline u32
transport_lba_21(unsigned char *cdb
)
204 return ((cdb
[1] & 0x1f) << 16) | (cdb
[2] << 8) | cdb
[3];
207 static inline u32
transport_lba_32(unsigned char *cdb
)
209 return (cdb
[2] << 24) | (cdb
[3] << 16) | (cdb
[4] << 8) | cdb
[5];
212 static inline unsigned long long transport_lba_64(unsigned char *cdb
)
214 unsigned int __v1
, __v2
;
216 __v1
= (cdb
[2] << 24) | (cdb
[3] << 16) | (cdb
[4] << 8) | cdb
[5];
217 __v2
= (cdb
[6] << 24) | (cdb
[7] << 16) | (cdb
[8] << 8) | cdb
[9];
219 return ((unsigned long long)__v2
) | (unsigned long long)__v1
<< 32;
223 * For VARIABLE_LENGTH_CDB w/ 32 byte extended CDBs
225 static inline unsigned long long transport_lba_64_ext(unsigned char *cdb
)
227 unsigned int __v1
, __v2
;
229 __v1
= (cdb
[12] << 24) | (cdb
[13] << 16) | (cdb
[14] << 8) | cdb
[15];
230 __v2
= (cdb
[16] << 24) | (cdb
[17] << 16) | (cdb
[18] << 8) | cdb
[19];
232 return ((unsigned long long)__v2
) | (unsigned long long)__v1
<< 32;
235 static sense_reason_t
236 sbc_setup_write_same(struct se_cmd
*cmd
, unsigned char *flags
, struct sbc_ops
*ops
)
238 unsigned int sectors
= spc_get_write_same_sectors(cmd
);
240 if ((flags
[0] & 0x04) || (flags
[0] & 0x02)) {
241 pr_err("WRITE_SAME PBDATA and LBDATA"
242 " bits not supported for Block Discard"
244 return TCM_UNSUPPORTED_SCSI_OPCODE
;
246 if (sectors
> cmd
->se_dev
->dev_attrib
.max_write_same_len
) {
247 pr_warn("WRITE_SAME sectors: %u exceeds max_write_same_len: %u\n",
248 sectors
, cmd
->se_dev
->dev_attrib
.max_write_same_len
);
249 return TCM_INVALID_CDB_FIELD
;
252 * Special case for WRITE_SAME w/ UNMAP=1 that ends up getting
253 * translated into block discard requests within backend code.
255 if (flags
[0] & 0x08) {
256 if (!ops
->execute_write_same_unmap
)
257 return TCM_UNSUPPORTED_SCSI_OPCODE
;
259 cmd
->execute_cmd
= ops
->execute_write_same_unmap
;
262 if (!ops
->execute_write_same
)
263 return TCM_UNSUPPORTED_SCSI_OPCODE
;
265 cmd
->execute_cmd
= ops
->execute_write_same
;
269 static void xdreadwrite_callback(struct se_cmd
*cmd
)
271 unsigned char *buf
, *addr
;
272 struct scatterlist
*sg
;
277 * From sbc3r22.pdf section 5.48 XDWRITEREAD (10) command
279 * 1) read the specified logical block(s);
280 * 2) transfer logical blocks from the data-out buffer;
281 * 3) XOR the logical blocks transferred from the data-out buffer with
282 * the logical blocks read, storing the resulting XOR data in a buffer;
283 * 4) if the DISABLE WRITE bit is set to zero, then write the logical
284 * blocks transferred from the data-out buffer; and
285 * 5) transfer the resulting XOR data to the data-in buffer.
287 buf
= kmalloc(cmd
->data_length
, GFP_KERNEL
);
289 pr_err("Unable to allocate xor_callback buf\n");
293 * Copy the scatterlist WRITE buffer located at cmd->t_data_sg
294 * into the locally allocated *buf
296 sg_copy_to_buffer(cmd
->t_data_sg
,
302 * Now perform the XOR against the BIDI read memory located at
303 * cmd->t_mem_bidi_list
307 for_each_sg(cmd
->t_bidi_data_sg
, sg
, cmd
->t_bidi_data_nents
, count
) {
308 addr
= kmap_atomic(sg_page(sg
));
312 for (i
= 0; i
< sg
->length
; i
++)
313 *(addr
+ sg
->offset
+ i
) ^= *(buf
+ offset
+ i
);
315 offset
+= sg
->length
;
324 sbc_parse_cdb(struct se_cmd
*cmd
, struct sbc_ops
*ops
)
326 struct se_device
*dev
= cmd
->se_dev
;
327 unsigned char *cdb
= cmd
->t_task_cdb
;
334 sectors
= transport_get_sectors_6(cdb
);
335 cmd
->t_task_lba
= transport_lba_21(cdb
);
336 cmd
->se_cmd_flags
|= SCF_SCSI_DATA_CDB
;
337 cmd
->execute_cmd
= ops
->execute_rw
;
340 sectors
= transport_get_sectors_10(cdb
);
341 cmd
->t_task_lba
= transport_lba_32(cdb
);
342 cmd
->se_cmd_flags
|= SCF_SCSI_DATA_CDB
;
343 cmd
->execute_cmd
= ops
->execute_rw
;
346 sectors
= transport_get_sectors_12(cdb
);
347 cmd
->t_task_lba
= transport_lba_32(cdb
);
348 cmd
->se_cmd_flags
|= SCF_SCSI_DATA_CDB
;
349 cmd
->execute_cmd
= ops
->execute_rw
;
352 sectors
= transport_get_sectors_16(cdb
);
353 cmd
->t_task_lba
= transport_lba_64(cdb
);
354 cmd
->se_cmd_flags
|= SCF_SCSI_DATA_CDB
;
355 cmd
->execute_cmd
= ops
->execute_rw
;
358 sectors
= transport_get_sectors_6(cdb
);
359 cmd
->t_task_lba
= transport_lba_21(cdb
);
360 cmd
->se_cmd_flags
|= SCF_SCSI_DATA_CDB
;
361 cmd
->execute_cmd
= ops
->execute_rw
;
365 sectors
= transport_get_sectors_10(cdb
);
366 cmd
->t_task_lba
= transport_lba_32(cdb
);
368 cmd
->se_cmd_flags
|= SCF_FUA
;
369 cmd
->se_cmd_flags
|= SCF_SCSI_DATA_CDB
;
370 cmd
->execute_cmd
= ops
->execute_rw
;
373 sectors
= transport_get_sectors_12(cdb
);
374 cmd
->t_task_lba
= transport_lba_32(cdb
);
376 cmd
->se_cmd_flags
|= SCF_FUA
;
377 cmd
->se_cmd_flags
|= SCF_SCSI_DATA_CDB
;
378 cmd
->execute_cmd
= ops
->execute_rw
;
381 sectors
= transport_get_sectors_16(cdb
);
382 cmd
->t_task_lba
= transport_lba_64(cdb
);
384 cmd
->se_cmd_flags
|= SCF_FUA
;
385 cmd
->se_cmd_flags
|= SCF_SCSI_DATA_CDB
;
386 cmd
->execute_cmd
= ops
->execute_rw
;
389 if (cmd
->data_direction
!= DMA_TO_DEVICE
||
390 !(cmd
->se_cmd_flags
& SCF_BIDI
))
391 return TCM_INVALID_CDB_FIELD
;
392 sectors
= transport_get_sectors_10(cdb
);
394 cmd
->t_task_lba
= transport_lba_32(cdb
);
395 cmd
->se_cmd_flags
|= SCF_SCSI_DATA_CDB
;
398 * Setup BIDI XOR callback to be run after I/O completion.
400 cmd
->execute_cmd
= ops
->execute_rw
;
401 cmd
->transport_complete_callback
= &xdreadwrite_callback
;
403 cmd
->se_cmd_flags
|= SCF_FUA
;
405 case VARIABLE_LENGTH_CMD
:
407 u16 service_action
= get_unaligned_be16(&cdb
[8]);
408 switch (service_action
) {
410 sectors
= transport_get_sectors_32(cdb
);
413 * Use WRITE_32 and READ_32 opcodes for the emulated
414 * XDWRITE_READ_32 logic.
416 cmd
->t_task_lba
= transport_lba_64_ext(cdb
);
417 cmd
->se_cmd_flags
|= SCF_SCSI_DATA_CDB
;
420 * Setup BIDI XOR callback to be run during after I/O
423 cmd
->execute_cmd
= ops
->execute_rw
;
424 cmd
->transport_complete_callback
= &xdreadwrite_callback
;
426 cmd
->se_cmd_flags
|= SCF_FUA
;
429 sectors
= transport_get_sectors_32(cdb
);
431 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
433 return TCM_INVALID_CDB_FIELD
;
436 size
= sbc_get_size(cmd
, 1);
437 cmd
->t_task_lba
= get_unaligned_be64(&cdb
[12]);
439 ret
= sbc_setup_write_same(cmd
, &cdb
[10], ops
);
444 pr_err("VARIABLE_LENGTH_CMD service action"
445 " 0x%04x not supported\n", service_action
);
446 return TCM_UNSUPPORTED_SCSI_OPCODE
;
452 cmd
->execute_cmd
= sbc_emulate_readcapacity
;
454 case SERVICE_ACTION_IN
:
455 switch (cmd
->t_task_cdb
[1] & 0x1f) {
456 case SAI_READ_CAPACITY_16
:
457 cmd
->execute_cmd
= sbc_emulate_readcapacity_16
;
460 pr_err("Unsupported SA: 0x%02x\n",
461 cmd
->t_task_cdb
[1] & 0x1f);
462 return TCM_INVALID_CDB_FIELD
;
464 size
= (cdb
[10] << 24) | (cdb
[11] << 16) |
465 (cdb
[12] << 8) | cdb
[13];
467 case SYNCHRONIZE_CACHE
:
468 case SYNCHRONIZE_CACHE_16
:
469 if (!ops
->execute_sync_cache
)
470 return TCM_UNSUPPORTED_SCSI_OPCODE
;
473 * Extract LBA and range to be flushed for emulated SYNCHRONIZE_CACHE
475 if (cdb
[0] == SYNCHRONIZE_CACHE
) {
476 sectors
= transport_get_sectors_10(cdb
);
477 cmd
->t_task_lba
= transport_lba_32(cdb
);
479 sectors
= transport_get_sectors_16(cdb
);
480 cmd
->t_task_lba
= transport_lba_64(cdb
);
483 size
= sbc_get_size(cmd
, sectors
);
486 * Check to ensure that LBA + Range does not exceed past end of
487 * device for IBLOCK and FILEIO ->do_sync_cache() backend calls
489 if (cmd
->t_task_lba
|| sectors
) {
490 if (sbc_check_valid_sectors(cmd
) < 0)
491 return TCM_INVALID_CDB_FIELD
;
493 cmd
->execute_cmd
= ops
->execute_sync_cache
;
496 if (!ops
->execute_unmap
)
497 return TCM_UNSUPPORTED_SCSI_OPCODE
;
499 size
= get_unaligned_be16(&cdb
[7]);
500 cmd
->execute_cmd
= ops
->execute_unmap
;
503 sectors
= transport_get_sectors_16(cdb
);
505 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
506 return TCM_INVALID_CDB_FIELD
;
509 size
= sbc_get_size(cmd
, 1);
510 cmd
->t_task_lba
= get_unaligned_be64(&cdb
[2]);
512 ret
= sbc_setup_write_same(cmd
, &cdb
[1], ops
);
517 sectors
= transport_get_sectors_10(cdb
);
519 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
520 return TCM_INVALID_CDB_FIELD
;
523 size
= sbc_get_size(cmd
, 1);
524 cmd
->t_task_lba
= get_unaligned_be32(&cdb
[2]);
527 * Follow sbcr26 with WRITE_SAME (10) and check for the existence
528 * of byte 1 bit 3 UNMAP instead of original reserved field
530 ret
= sbc_setup_write_same(cmd
, &cdb
[1], ops
);
536 cmd
->execute_cmd
= sbc_emulate_noop
;
542 * There are still clients out there which use these old SCSI-2
543 * commands. This mainly happens when running VMs with legacy
544 * guest systems, connected via SCSI command pass-through to
545 * iSCSI targets. Make them happy and return status GOOD.
548 cmd
->execute_cmd
= sbc_emulate_noop
;
551 ret
= spc_parse_cdb(cmd
, &size
);
556 /* reject any command that we don't have a handler for */
557 if (!(cmd
->se_cmd_flags
& SCF_SCSI_DATA_CDB
) && !cmd
->execute_cmd
)
558 return TCM_UNSUPPORTED_SCSI_OPCODE
;
560 if (cmd
->se_cmd_flags
& SCF_SCSI_DATA_CDB
) {
561 unsigned long long end_lba
;
563 if (sectors
> dev
->dev_attrib
.fabric_max_sectors
) {
564 printk_ratelimited(KERN_ERR
"SCSI OP %02xh with too"
565 " big sectors %u exceeds fabric_max_sectors:"
566 " %u\n", cdb
[0], sectors
,
567 dev
->dev_attrib
.fabric_max_sectors
);
568 return TCM_INVALID_CDB_FIELD
;
570 if (sectors
> dev
->dev_attrib
.hw_max_sectors
) {
571 printk_ratelimited(KERN_ERR
"SCSI OP %02xh with too"
572 " big sectors %u exceeds backend hw_max_sectors:"
573 " %u\n", cdb
[0], sectors
,
574 dev
->dev_attrib
.hw_max_sectors
);
575 return TCM_INVALID_CDB_FIELD
;
578 end_lba
= dev
->transport
->get_blocks(dev
) + 1;
579 if (cmd
->t_task_lba
+ sectors
> end_lba
) {
580 pr_err("cmd exceeds last lba %llu "
581 "(lba %llu, sectors %u)\n",
582 end_lba
, cmd
->t_task_lba
, sectors
);
583 return TCM_INVALID_CDB_FIELD
;
586 size
= sbc_get_size(cmd
, sectors
);
589 return target_cmd_size_check(cmd
, size
);
591 EXPORT_SYMBOL(sbc_parse_cdb
);
593 u32
sbc_get_device_type(struct se_device
*dev
)
597 EXPORT_SYMBOL(sbc_get_device_type
);