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 memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
63 transport_kunmap_data_sg(cmd);
66 target_complete_cmd(cmd, GOOD);
71 sbc_emulate_readcapacity_16(struct se_cmd *cmd)
73 struct se_device *dev = cmd->se_dev;
75 unsigned char buf[32];
76 unsigned long long blocks = dev->transport->get_blocks(dev);
78 memset(buf, 0, sizeof(buf));
79 buf[0] = (blocks >> 56) & 0xff;
80 buf[1] = (blocks >> 48) & 0xff;
81 buf[2] = (blocks >> 40) & 0xff;
82 buf[3] = (blocks >> 32) & 0xff;
83 buf[4] = (blocks >> 24) & 0xff;
84 buf[5] = (blocks >> 16) & 0xff;
85 buf[6] = (blocks >> 8) & 0xff;
86 buf[7] = blocks & 0xff;
87 buf[8] = (dev->dev_attrib.block_size >> 24) & 0xff;
88 buf[9] = (dev->dev_attrib.block_size >> 16) & 0xff;
89 buf[10] = (dev->dev_attrib.block_size >> 8) & 0xff;
90 buf[11] = dev->dev_attrib.block_size & 0xff;
92 * Set Thin Provisioning Enable bit following sbc3r22 in section
93 * READ CAPACITY (16) byte 14 if emulate_tpu or emulate_tpws is enabled.
95 if (dev->dev_attrib.emulate_tpu || dev->dev_attrib.emulate_tpws)
98 rbuf = transport_kmap_data_sg(cmd);
100 memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
101 transport_kunmap_data_sg(cmd);
104 target_complete_cmd(cmd, GOOD);
108 sector_t sbc_get_write_same_sectors(struct se_cmd *cmd)
112 if (cmd->t_task_cdb[0] == WRITE_SAME)
113 num_blocks = get_unaligned_be16(&cmd->t_task_cdb[7]);
114 else if (cmd->t_task_cdb[0] == WRITE_SAME_16)
115 num_blocks = get_unaligned_be32(&cmd->t_task_cdb[10]);
116 else /* WRITE_SAME_32 via VARIABLE_LENGTH_CMD */
117 num_blocks = get_unaligned_be32(&cmd->t_task_cdb[28]);
120 * Use the explicit range when non zero is supplied, otherwise calculate
121 * the remaining range based on ->get_blocks() - starting LBA.
126 return cmd->se_dev->transport->get_blocks(cmd->se_dev) -
129 EXPORT_SYMBOL(sbc_get_write_same_sectors);
131 static sense_reason_t
132 sbc_emulate_noop(struct se_cmd *cmd)
134 target_complete_cmd(cmd, GOOD);
138 static inline u32 sbc_get_size(struct se_cmd *cmd, u32 sectors)
140 return cmd->se_dev->dev_attrib.block_size * sectors;
143 static int sbc_check_valid_sectors(struct se_cmd *cmd)
145 struct se_device *dev = cmd->se_dev;
146 unsigned long long end_lba;
149 sectors = cmd->data_length / dev->dev_attrib.block_size;
150 end_lba = dev->transport->get_blocks(dev) + 1;
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);
161 static inline u32 transport_get_sectors_6(unsigned char *cdb)
164 * Use 8-bit sector value. SBC-3 says:
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
171 return cdb[4] ? : 256;
174 static inline u32 transport_get_sectors_10(unsigned char *cdb)
176 return (u32)(cdb[7] << 8) + cdb[8];
179 static inline u32 transport_get_sectors_12(unsigned char *cdb)
181 return (u32)(cdb[6] << 24) + (cdb[7] << 16) + (cdb[8] << 8) + cdb[9];
184 static inline u32 transport_get_sectors_16(unsigned char *cdb)
186 return (u32)(cdb[10] << 24) + (cdb[11] << 16) +
187 (cdb[12] << 8) + cdb[13];
191 * Used for VARIABLE_LENGTH_CDB WRITE_32 and READ_32 variants
193 static inline u32 transport_get_sectors_32(unsigned char *cdb)
195 return (u32)(cdb[28] << 24) + (cdb[29] << 16) +
196 (cdb[30] << 8) + cdb[31];
200 static inline u32 transport_lba_21(unsigned char *cdb)
202 return ((cdb[1] & 0x1f) << 16) | (cdb[2] << 8) | cdb[3];
205 static inline u32 transport_lba_32(unsigned char *cdb)
207 return (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
210 static inline unsigned long long transport_lba_64(unsigned char *cdb)
212 unsigned int __v1, __v2;
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];
217 return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
221 * For VARIABLE_LENGTH_CDB w/ 32 byte extended CDBs
223 static inline unsigned long long transport_lba_64_ext(unsigned char *cdb)
225 unsigned int __v1, __v2;
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];
230 return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
233 static sense_reason_t
234 sbc_setup_write_same(struct se_cmd *cmd, unsigned char *flags, struct sbc_ops *ops)
236 unsigned int sectors = sbc_get_write_same_sectors(cmd);
238 if ((flags[0] & 0x04) || (flags[0] & 0x02)) {
239 pr_err("WRITE_SAME PBDATA and LBDATA"
240 " bits not supported for Block Discard"
242 return TCM_UNSUPPORTED_SCSI_OPCODE;
244 if (sectors > cmd->se_dev->dev_attrib.max_write_same_len) {
245 pr_warn("WRITE_SAME sectors: %u exceeds max_write_same_len: %u\n",
246 sectors, cmd->se_dev->dev_attrib.max_write_same_len);
247 return TCM_INVALID_CDB_FIELD;
250 * Special case for WRITE_SAME w/ UNMAP=1 that ends up getting
251 * translated into block discard requests within backend code.
253 if (flags[0] & 0x08) {
254 if (!ops->execute_write_same_unmap)
255 return TCM_UNSUPPORTED_SCSI_OPCODE;
257 cmd->execute_cmd = ops->execute_write_same_unmap;
260 if (!ops->execute_write_same)
261 return TCM_UNSUPPORTED_SCSI_OPCODE;
263 cmd->execute_cmd = ops->execute_write_same;
267 static void xdreadwrite_callback(struct se_cmd *cmd)
269 unsigned char *buf, *addr;
270 struct scatterlist *sg;
275 * From sbc3r22.pdf section 5.48 XDWRITEREAD (10) command
277 * 1) read the specified logical block(s);
278 * 2) transfer logical blocks from the data-out buffer;
279 * 3) XOR the logical blocks transferred from the data-out buffer with
280 * the logical blocks read, storing the resulting XOR data in a buffer;
281 * 4) if the DISABLE WRITE bit is set to zero, then write the logical
282 * blocks transferred from the data-out buffer; and
283 * 5) transfer the resulting XOR data to the data-in buffer.
285 buf = kmalloc(cmd->data_length, GFP_KERNEL);
287 pr_err("Unable to allocate xor_callback buf\n");
291 * Copy the scatterlist WRITE buffer located at cmd->t_data_sg
292 * into the locally allocated *buf
294 sg_copy_to_buffer(cmd->t_data_sg,
300 * Now perform the XOR against the BIDI read memory located at
301 * cmd->t_mem_bidi_list
305 for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, count) {
306 addr = kmap_atomic(sg_page(sg));
310 for (i = 0; i < sg->length; i++)
311 *(addr + sg->offset + i) ^= *(buf + offset + i);
313 offset += sg->length;
322 sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
324 struct se_device *dev = cmd->se_dev;
325 unsigned char *cdb = cmd->t_task_cdb;
332 sectors = transport_get_sectors_6(cdb);
333 cmd->t_task_lba = transport_lba_21(cdb);
334 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
335 cmd->execute_cmd = ops->execute_rw;
338 sectors = transport_get_sectors_10(cdb);
339 cmd->t_task_lba = transport_lba_32(cdb);
340 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
341 cmd->execute_cmd = ops->execute_rw;
344 sectors = transport_get_sectors_12(cdb);
345 cmd->t_task_lba = transport_lba_32(cdb);
346 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
347 cmd->execute_cmd = ops->execute_rw;
350 sectors = transport_get_sectors_16(cdb);
351 cmd->t_task_lba = transport_lba_64(cdb);
352 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
353 cmd->execute_cmd = ops->execute_rw;
356 sectors = transport_get_sectors_6(cdb);
357 cmd->t_task_lba = transport_lba_21(cdb);
358 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
359 cmd->execute_cmd = ops->execute_rw;
363 sectors = transport_get_sectors_10(cdb);
364 cmd->t_task_lba = transport_lba_32(cdb);
366 cmd->se_cmd_flags |= SCF_FUA;
367 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
368 cmd->execute_cmd = ops->execute_rw;
371 sectors = transport_get_sectors_12(cdb);
372 cmd->t_task_lba = transport_lba_32(cdb);
374 cmd->se_cmd_flags |= SCF_FUA;
375 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
376 cmd->execute_cmd = ops->execute_rw;
379 sectors = transport_get_sectors_16(cdb);
380 cmd->t_task_lba = transport_lba_64(cdb);
382 cmd->se_cmd_flags |= SCF_FUA;
383 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
384 cmd->execute_cmd = ops->execute_rw;
387 if (cmd->data_direction != DMA_TO_DEVICE ||
388 !(cmd->se_cmd_flags & SCF_BIDI))
389 return TCM_INVALID_CDB_FIELD;
390 sectors = transport_get_sectors_10(cdb);
392 cmd->t_task_lba = transport_lba_32(cdb);
393 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
396 * Setup BIDI XOR callback to be run after I/O completion.
398 cmd->execute_cmd = ops->execute_rw;
399 cmd->transport_complete_callback = &xdreadwrite_callback;
401 cmd->se_cmd_flags |= SCF_FUA;
403 case VARIABLE_LENGTH_CMD:
405 u16 service_action = get_unaligned_be16(&cdb[8]);
406 switch (service_action) {
408 sectors = transport_get_sectors_32(cdb);
411 * Use WRITE_32 and READ_32 opcodes for the emulated
412 * XDWRITE_READ_32 logic.
414 cmd->t_task_lba = transport_lba_64_ext(cdb);
415 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
418 * Setup BIDI XOR callback to be run during after I/O
421 cmd->execute_cmd = ops->execute_rw;
422 cmd->transport_complete_callback = &xdreadwrite_callback;
424 cmd->se_cmd_flags |= SCF_FUA;
427 sectors = transport_get_sectors_32(cdb);
429 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
431 return TCM_INVALID_CDB_FIELD;
434 size = sbc_get_size(cmd, 1);
435 cmd->t_task_lba = get_unaligned_be64(&cdb[12]);
437 ret = sbc_setup_write_same(cmd, &cdb[10], ops);
442 pr_err("VARIABLE_LENGTH_CMD service action"
443 " 0x%04x not supported\n", service_action);
444 return TCM_UNSUPPORTED_SCSI_OPCODE;
450 cmd->execute_cmd = sbc_emulate_readcapacity;
452 case SERVICE_ACTION_IN:
453 switch (cmd->t_task_cdb[1] & 0x1f) {
454 case SAI_READ_CAPACITY_16:
455 cmd->execute_cmd = sbc_emulate_readcapacity_16;
458 pr_err("Unsupported SA: 0x%02x\n",
459 cmd->t_task_cdb[1] & 0x1f);
460 return TCM_INVALID_CDB_FIELD;
462 size = (cdb[10] << 24) | (cdb[11] << 16) |
463 (cdb[12] << 8) | cdb[13];
465 case SYNCHRONIZE_CACHE:
466 case SYNCHRONIZE_CACHE_16:
467 if (!ops->execute_sync_cache)
468 return TCM_UNSUPPORTED_SCSI_OPCODE;
471 * Extract LBA and range to be flushed for emulated SYNCHRONIZE_CACHE
473 if (cdb[0] == SYNCHRONIZE_CACHE) {
474 sectors = transport_get_sectors_10(cdb);
475 cmd->t_task_lba = transport_lba_32(cdb);
477 sectors = transport_get_sectors_16(cdb);
478 cmd->t_task_lba = transport_lba_64(cdb);
481 size = sbc_get_size(cmd, sectors);
484 * Check to ensure that LBA + Range does not exceed past end of
485 * device for IBLOCK and FILEIO ->do_sync_cache() backend calls
487 if (cmd->t_task_lba || sectors) {
488 if (sbc_check_valid_sectors(cmd) < 0)
489 return TCM_ADDRESS_OUT_OF_RANGE;
491 cmd->execute_cmd = ops->execute_sync_cache;
494 if (!ops->execute_unmap)
495 return TCM_UNSUPPORTED_SCSI_OPCODE;
497 size = get_unaligned_be16(&cdb[7]);
498 cmd->execute_cmd = ops->execute_unmap;
501 sectors = transport_get_sectors_16(cdb);
503 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
504 return TCM_INVALID_CDB_FIELD;
507 size = sbc_get_size(cmd, 1);
508 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
510 ret = sbc_setup_write_same(cmd, &cdb[1], ops);
515 sectors = transport_get_sectors_10(cdb);
517 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
518 return TCM_INVALID_CDB_FIELD;
521 size = sbc_get_size(cmd, 1);
522 cmd->t_task_lba = get_unaligned_be32(&cdb[2]);
525 * Follow sbcr26 with WRITE_SAME (10) and check for the existence
526 * of byte 1 bit 3 UNMAP instead of original reserved field
528 ret = sbc_setup_write_same(cmd, &cdb[1], ops);
534 cmd->execute_cmd = sbc_emulate_noop;
540 * There are still clients out there which use these old SCSI-2
541 * commands. This mainly happens when running VMs with legacy
542 * guest systems, connected via SCSI command pass-through to
543 * iSCSI targets. Make them happy and return status GOOD.
546 cmd->execute_cmd = sbc_emulate_noop;
549 ret = spc_parse_cdb(cmd, &size);
554 /* reject any command that we don't have a handler for */
555 if (!(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) && !cmd->execute_cmd)
556 return TCM_UNSUPPORTED_SCSI_OPCODE;
558 if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
559 unsigned long long end_lba;
561 if (sectors > dev->dev_attrib.fabric_max_sectors) {
562 printk_ratelimited(KERN_ERR "SCSI OP %02xh with too"
563 " big sectors %u exceeds fabric_max_sectors:"
564 " %u\n", cdb[0], sectors,
565 dev->dev_attrib.fabric_max_sectors);
566 return TCM_INVALID_CDB_FIELD;
568 if (sectors > dev->dev_attrib.hw_max_sectors) {
569 printk_ratelimited(KERN_ERR "SCSI OP %02xh with too"
570 " big sectors %u exceeds backend hw_max_sectors:"
571 " %u\n", cdb[0], sectors,
572 dev->dev_attrib.hw_max_sectors);
573 return TCM_INVALID_CDB_FIELD;
576 end_lba = dev->transport->get_blocks(dev) + 1;
577 if (cmd->t_task_lba + sectors > end_lba) {
578 pr_err("cmd exceeds last lba %llu "
579 "(lba %llu, sectors %u)\n",
580 end_lba, cmd->t_task_lba, sectors);
581 return TCM_INVALID_CDB_FIELD;
584 size = sbc_get_size(cmd, sectors);
587 return target_cmd_size_check(cmd, size);
589 EXPORT_SYMBOL(sbc_parse_cdb);
591 u32 sbc_get_device_type(struct se_device *dev)
595 EXPORT_SYMBOL(sbc_get_device_type);