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);