diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/target/target_core_sbc.c | 1394 |
1 files changed, 1394 insertions, 0 deletions
diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c new file mode 100644 index 000000000..1e3216de1 --- /dev/null +++ b/drivers/target/target_core_sbc.c @@ -0,0 +1,1394 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * SCSI Block Commands (SBC) parsing and emulation. + * + * (c) Copyright 2002-2013 Datera, Inc. + * + * Nicholas A. Bellinger <nab@kernel.org> + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/ratelimit.h> +#include <linux/crc-t10dif.h> +#include <linux/t10-pi.h> +#include <asm/unaligned.h> +#include <scsi/scsi_proto.h> +#include <scsi/scsi_tcq.h> + +#include <target/target_core_base.h> +#include <target/target_core_backend.h> +#include <target/target_core_fabric.h> + +#include "target_core_internal.h" +#include "target_core_ua.h" +#include "target_core_alua.h" + +static sense_reason_t +sbc_check_prot(struct se_device *, struct se_cmd *, unsigned char, u32, bool); +static sense_reason_t sbc_execute_unmap(struct se_cmd *cmd); + +static sense_reason_t +sbc_emulate_readcapacity(struct se_cmd *cmd) +{ + struct se_device *dev = cmd->se_dev; + unsigned char *cdb = cmd->t_task_cdb; + unsigned long long blocks_long = dev->transport->get_blocks(dev); + unsigned char *rbuf; + unsigned char buf[8]; + u32 blocks; + + /* + * SBC-2 says: + * If the PMI bit is set to zero and the LOGICAL BLOCK + * ADDRESS field is not set to zero, the device server shall + * terminate the command with CHECK CONDITION status with + * the sense key set to ILLEGAL REQUEST and the additional + * sense code set to INVALID FIELD IN CDB. + * + * In SBC-3, these fields are obsolete, but some SCSI + * compliance tests actually check this, so we might as well + * follow SBC-2. + */ + if (!(cdb[8] & 1) && !!(cdb[2] | cdb[3] | cdb[4] | cdb[5])) + return TCM_INVALID_CDB_FIELD; + + if (blocks_long >= 0x00000000ffffffff) + blocks = 0xffffffff; + else + blocks = (u32)blocks_long; + + put_unaligned_be32(blocks, &buf[0]); + put_unaligned_be32(dev->dev_attrib.block_size, &buf[4]); + + rbuf = transport_kmap_data_sg(cmd); + if (rbuf) { + memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length)); + transport_kunmap_data_sg(cmd); + } + + target_complete_cmd_with_length(cmd, SAM_STAT_GOOD, 8); + return 0; +} + +static sense_reason_t +sbc_emulate_readcapacity_16(struct se_cmd *cmd) +{ + struct se_device *dev = cmd->se_dev; + struct se_session *sess = cmd->se_sess; + int pi_prot_type = dev->dev_attrib.pi_prot_type; + + unsigned char *rbuf; + unsigned char buf[32]; + unsigned long long blocks = dev->transport->get_blocks(dev); + + memset(buf, 0, sizeof(buf)); + put_unaligned_be64(blocks, &buf[0]); + put_unaligned_be32(dev->dev_attrib.block_size, &buf[8]); + /* + * Set P_TYPE and PROT_EN bits for DIF support + */ + if (sess->sup_prot_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS)) { + /* + * Only override a device's pi_prot_type if no T10-PI is + * available, and sess_prot_type has been explicitly enabled. + */ + if (!pi_prot_type) + pi_prot_type = sess->sess_prot_type; + + if (pi_prot_type) + buf[12] = (pi_prot_type - 1) << 1 | 0x1; + } + + if (dev->transport->get_lbppbe) + buf[13] = dev->transport->get_lbppbe(dev) & 0x0f; + + if (dev->transport->get_alignment_offset_lbas) { + u16 lalba = dev->transport->get_alignment_offset_lbas(dev); + + put_unaligned_be16(lalba, &buf[14]); + } + + /* + * Set Thin Provisioning Enable bit following sbc3r22 in section + * READ CAPACITY (16) byte 14 if emulate_tpu or emulate_tpws is enabled. + */ + if (dev->dev_attrib.emulate_tpu || dev->dev_attrib.emulate_tpws) { + buf[14] |= 0x80; + + /* + * LBPRZ signifies that zeroes will be read back from an LBA after + * an UNMAP or WRITE SAME w/ unmap bit (sbc3r36 5.16.2) + */ + if (dev->dev_attrib.unmap_zeroes_data) + buf[14] |= 0x40; + } + + rbuf = transport_kmap_data_sg(cmd); + if (rbuf) { + memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length)); + transport_kunmap_data_sg(cmd); + } + + target_complete_cmd_with_length(cmd, SAM_STAT_GOOD, 32); + return 0; +} + +static sense_reason_t +sbc_emulate_startstop(struct se_cmd *cmd) +{ + unsigned char *cdb = cmd->t_task_cdb; + + /* + * See sbc3r36 section 5.25 + * Immediate bit should be set since there is nothing to complete + * POWER CONDITION MODIFIER 0h + */ + if (!(cdb[1] & 1) || cdb[2] || cdb[3]) + return TCM_INVALID_CDB_FIELD; + + /* + * See sbc3r36 section 5.25 + * POWER CONDITION 0h START_VALID - process START and LOEJ + */ + if (cdb[4] >> 4 & 0xf) + return TCM_INVALID_CDB_FIELD; + + /* + * See sbc3r36 section 5.25 + * LOEJ 0h - nothing to load or unload + * START 1h - we are ready + */ + if (!(cdb[4] & 1) || (cdb[4] & 2) || (cdb[4] & 4)) + return TCM_INVALID_CDB_FIELD; + + target_complete_cmd(cmd, SAM_STAT_GOOD); + return 0; +} + +sector_t sbc_get_write_same_sectors(struct se_cmd *cmd) +{ + u32 num_blocks; + + if (cmd->t_task_cdb[0] == WRITE_SAME) + num_blocks = get_unaligned_be16(&cmd->t_task_cdb[7]); + else if (cmd->t_task_cdb[0] == WRITE_SAME_16) + num_blocks = get_unaligned_be32(&cmd->t_task_cdb[10]); + else /* WRITE_SAME_32 via VARIABLE_LENGTH_CMD */ + num_blocks = get_unaligned_be32(&cmd->t_task_cdb[28]); + + /* + * Use the explicit range when non zero is supplied, otherwise calculate + * the remaining range based on ->get_blocks() - starting LBA. + */ + if (num_blocks) + return num_blocks; + + return cmd->se_dev->transport->get_blocks(cmd->se_dev) - + cmd->t_task_lba + 1; +} +EXPORT_SYMBOL(sbc_get_write_same_sectors); + +static sense_reason_t +sbc_execute_write_same_unmap(struct se_cmd *cmd) +{ + struct sbc_ops *ops = cmd->protocol_data; + sector_t nolb = sbc_get_write_same_sectors(cmd); + sense_reason_t ret; + + if (nolb) { + ret = ops->execute_unmap(cmd, cmd->t_task_lba, nolb); + if (ret) + return ret; + } + + target_complete_cmd(cmd, SAM_STAT_GOOD); + return 0; +} + +static sense_reason_t +sbc_emulate_noop(struct se_cmd *cmd) +{ + target_complete_cmd(cmd, SAM_STAT_GOOD); + return 0; +} + +static inline u32 sbc_get_size(struct se_cmd *cmd, u32 sectors) +{ + return cmd->se_dev->dev_attrib.block_size * sectors; +} + +static inline u32 transport_get_sectors_6(unsigned char *cdb) +{ + /* + * Use 8-bit sector value. SBC-3 says: + * + * A TRANSFER LENGTH field set to zero specifies that 256 + * logical blocks shall be written. Any other value + * specifies the number of logical blocks that shall be + * written. + */ + return cdb[4] ? : 256; +} + +static inline u32 transport_get_sectors_10(unsigned char *cdb) +{ + return get_unaligned_be16(&cdb[7]); +} + +static inline u32 transport_get_sectors_12(unsigned char *cdb) +{ + return get_unaligned_be32(&cdb[6]); +} + +static inline u32 transport_get_sectors_16(unsigned char *cdb) +{ + return get_unaligned_be32(&cdb[10]); +} + +/* + * Used for VARIABLE_LENGTH_CDB WRITE_32 and READ_32 variants + */ +static inline u32 transport_get_sectors_32(unsigned char *cdb) +{ + return get_unaligned_be32(&cdb[28]); + +} + +static inline u32 transport_lba_21(unsigned char *cdb) +{ + return get_unaligned_be24(&cdb[1]) & 0x1fffff; +} + +static inline u32 transport_lba_32(unsigned char *cdb) +{ + return get_unaligned_be32(&cdb[2]); +} + +static inline unsigned long long transport_lba_64(unsigned char *cdb) +{ + return get_unaligned_be64(&cdb[2]); +} + +/* + * For VARIABLE_LENGTH_CDB w/ 32 byte extended CDBs + */ +static inline unsigned long long transport_lba_64_ext(unsigned char *cdb) +{ + return get_unaligned_be64(&cdb[12]); +} + +static sense_reason_t +sbc_setup_write_same(struct se_cmd *cmd, unsigned char flags, struct sbc_ops *ops) +{ + struct se_device *dev = cmd->se_dev; + sector_t end_lba = dev->transport->get_blocks(dev) + 1; + unsigned int sectors = sbc_get_write_same_sectors(cmd); + sense_reason_t ret; + + if ((flags & 0x04) || (flags & 0x02)) { + pr_err("WRITE_SAME PBDATA and LBDATA" + " bits not supported for Block Discard" + " Emulation\n"); + return TCM_UNSUPPORTED_SCSI_OPCODE; + } + if (sectors > cmd->se_dev->dev_attrib.max_write_same_len) { + pr_warn("WRITE_SAME sectors: %u exceeds max_write_same_len: %u\n", + sectors, cmd->se_dev->dev_attrib.max_write_same_len); + return TCM_INVALID_CDB_FIELD; + } + /* + * Sanity check for LBA wrap and request past end of device. + */ + if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) || + ((cmd->t_task_lba + sectors) > end_lba)) { + pr_err("WRITE_SAME exceeds last lba %llu (lba %llu, sectors %u)\n", + (unsigned long long)end_lba, cmd->t_task_lba, sectors); + return TCM_ADDRESS_OUT_OF_RANGE; + } + + /* We always have ANC_SUP == 0 so setting ANCHOR is always an error */ + if (flags & 0x10) { + pr_warn("WRITE SAME with ANCHOR not supported\n"); + return TCM_INVALID_CDB_FIELD; + } + + if (flags & 0x01) { + pr_warn("WRITE SAME with NDOB not supported\n"); + return TCM_INVALID_CDB_FIELD; + } + + /* + * Special case for WRITE_SAME w/ UNMAP=1 that ends up getting + * translated into block discard requests within backend code. + */ + if (flags & 0x08) { + if (!ops->execute_unmap) + return TCM_UNSUPPORTED_SCSI_OPCODE; + + if (!dev->dev_attrib.emulate_tpws) { + pr_err("Got WRITE_SAME w/ UNMAP=1, but backend device" + " has emulate_tpws disabled\n"); + return TCM_UNSUPPORTED_SCSI_OPCODE; + } + cmd->execute_cmd = sbc_execute_write_same_unmap; + return 0; + } + if (!ops->execute_write_same) + return TCM_UNSUPPORTED_SCSI_OPCODE; + + ret = sbc_check_prot(dev, cmd, flags >> 5, sectors, true); + if (ret) + return ret; + + cmd->execute_cmd = ops->execute_write_same; + return 0; +} + +static sense_reason_t +sbc_execute_rw(struct se_cmd *cmd) +{ + struct sbc_ops *ops = cmd->protocol_data; + + return ops->execute_rw(cmd, cmd->t_data_sg, cmd->t_data_nents, + cmd->data_direction); +} + +static sense_reason_t compare_and_write_post(struct se_cmd *cmd, bool success, + int *post_ret) +{ + struct se_device *dev = cmd->se_dev; + sense_reason_t ret = TCM_NO_SENSE; + + spin_lock_irq(&cmd->t_state_lock); + if (success) { + *post_ret = 1; + + if (cmd->scsi_status == SAM_STAT_CHECK_CONDITION) + ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; + } + spin_unlock_irq(&cmd->t_state_lock); + + /* + * Unlock ->caw_sem originally obtained during sbc_compare_and_write() + * before the original READ I/O submission. + */ + up(&dev->caw_sem); + + return ret; +} + +/* + * compare @cmp_len bytes of @read_sgl with @cmp_sgl. On miscompare, fill + * @miscmp_off and return TCM_MISCOMPARE_VERIFY. + */ +static sense_reason_t +compare_and_write_do_cmp(struct scatterlist *read_sgl, unsigned int read_nents, + struct scatterlist *cmp_sgl, unsigned int cmp_nents, + unsigned int cmp_len, unsigned int *miscmp_off) +{ + unsigned char *buf = NULL; + struct scatterlist *sg; + sense_reason_t ret; + unsigned int offset; + size_t rc; + int sg_cnt; + + buf = kzalloc(cmp_len, GFP_KERNEL); + if (!buf) { + ret = TCM_OUT_OF_RESOURCES; + goto out; + } + + rc = sg_copy_to_buffer(cmp_sgl, cmp_nents, buf, cmp_len); + if (!rc) { + pr_err("sg_copy_to_buffer() failed for compare_and_write\n"); + ret = TCM_OUT_OF_RESOURCES; + goto out; + } + /* + * Compare SCSI READ payload against verify payload + */ + offset = 0; + ret = TCM_NO_SENSE; + for_each_sg(read_sgl, sg, read_nents, sg_cnt) { + unsigned int len = min(sg->length, cmp_len); + unsigned char *addr = kmap_atomic(sg_page(sg)); + + if (memcmp(addr, buf + offset, len)) { + unsigned int i; + + for (i = 0; i < len && addr[i] == buf[offset + i]; i++) + ; + *miscmp_off = offset + i; + pr_warn("Detected MISCOMPARE at offset %u\n", + *miscmp_off); + ret = TCM_MISCOMPARE_VERIFY; + } + kunmap_atomic(addr); + if (ret != TCM_NO_SENSE) + goto out; + + offset += len; + cmp_len -= len; + if (!cmp_len) + break; + } + pr_debug("COMPARE AND WRITE read data matches compare data\n"); +out: + kfree(buf); + return ret; +} + +static sense_reason_t compare_and_write_callback(struct se_cmd *cmd, bool success, + int *post_ret) +{ + struct se_device *dev = cmd->se_dev; + struct sg_table write_tbl = { }; + struct scatterlist *write_sg; + struct sg_mapping_iter m; + unsigned int len; + unsigned int block_size = dev->dev_attrib.block_size; + unsigned int compare_len = (cmd->t_task_nolb * block_size); + unsigned int miscmp_off = 0; + sense_reason_t ret = TCM_NO_SENSE; + int i; + + /* + * Handle early failure in transport_generic_request_failure(), + * which will not have taken ->caw_sem yet.. + */ + if (!success && (!cmd->t_data_sg || !cmd->t_bidi_data_sg)) + return TCM_NO_SENSE; + /* + * Handle special case for zero-length COMPARE_AND_WRITE + */ + if (!cmd->data_length) + goto out; + /* + * Immediately exit + release dev->caw_sem if command has already + * been failed with a non-zero SCSI status. + */ + if (cmd->scsi_status) { + pr_debug("compare_and_write_callback: non zero scsi_status:" + " 0x%02x\n", cmd->scsi_status); + *post_ret = 1; + if (cmd->scsi_status == SAM_STAT_CHECK_CONDITION) + ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; + goto out; + } + + ret = compare_and_write_do_cmp(cmd->t_bidi_data_sg, + cmd->t_bidi_data_nents, + cmd->t_data_sg, + cmd->t_data_nents, + compare_len, + &miscmp_off); + if (ret == TCM_MISCOMPARE_VERIFY) { + /* + * SBC-4 r15: 5.3 COMPARE AND WRITE command + * In the sense data (see 4.18 and SPC-5) the offset from the + * start of the Data-Out Buffer to the first byte of data that + * was not equal shall be reported in the INFORMATION field. + */ + cmd->sense_info = miscmp_off; + goto out; + } else if (ret) + goto out; + + if (sg_alloc_table(&write_tbl, cmd->t_data_nents, GFP_KERNEL) < 0) { + pr_err("Unable to allocate compare_and_write sg\n"); + ret = TCM_OUT_OF_RESOURCES; + goto out; + } + write_sg = write_tbl.sgl; + + i = 0; + len = compare_len; + sg_miter_start(&m, cmd->t_data_sg, cmd->t_data_nents, SG_MITER_TO_SG); + /* + * Currently assumes NoLB=1 and SGLs are PAGE_SIZE.. + */ + while (len) { + sg_miter_next(&m); + + if (block_size < PAGE_SIZE) { + sg_set_page(&write_sg[i], m.page, block_size, + m.piter.sg->offset + block_size); + } else { + sg_miter_next(&m); + sg_set_page(&write_sg[i], m.page, block_size, + m.piter.sg->offset); + } + len -= block_size; + i++; + } + sg_miter_stop(&m); + /* + * Save the original SGL + nents values before updating to new + * assignments, to be released in transport_free_pages() -> + * transport_reset_sgl_orig() + */ + cmd->t_data_sg_orig = cmd->t_data_sg; + cmd->t_data_sg = write_sg; + cmd->t_data_nents_orig = cmd->t_data_nents; + cmd->t_data_nents = 1; + + cmd->sam_task_attr = TCM_HEAD_TAG; + cmd->transport_complete_callback = compare_and_write_post; + /* + * Now reset ->execute_cmd() to the normal sbc_execute_rw() handler + * for submitting the adjusted SGL to write instance user-data. + */ + cmd->execute_cmd = sbc_execute_rw; + + spin_lock_irq(&cmd->t_state_lock); + cmd->t_state = TRANSPORT_PROCESSING; + cmd->transport_state |= CMD_T_ACTIVE | CMD_T_SENT; + spin_unlock_irq(&cmd->t_state_lock); + + __target_execute_cmd(cmd, false); + + return ret; + +out: + /* + * In the MISCOMPARE or failure case, unlock ->caw_sem obtained in + * sbc_compare_and_write() before the original READ I/O submission. + */ + up(&dev->caw_sem); + sg_free_table(&write_tbl); + return ret; +} + +static sense_reason_t +sbc_compare_and_write(struct se_cmd *cmd) +{ + struct sbc_ops *ops = cmd->protocol_data; + struct se_device *dev = cmd->se_dev; + sense_reason_t ret; + int rc; + /* + * Submit the READ first for COMPARE_AND_WRITE to perform the + * comparision using SGLs at cmd->t_bidi_data_sg.. + */ + rc = down_interruptible(&dev->caw_sem); + if (rc != 0) { + cmd->transport_complete_callback = NULL; + return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; + } + /* + * Reset cmd->data_length to individual block_size in order to not + * confuse backend drivers that depend on this value matching the + * size of the I/O being submitted. + */ + cmd->data_length = cmd->t_task_nolb * dev->dev_attrib.block_size; + + ret = ops->execute_rw(cmd, cmd->t_bidi_data_sg, cmd->t_bidi_data_nents, + DMA_FROM_DEVICE); + if (ret) { + cmd->transport_complete_callback = NULL; + up(&dev->caw_sem); + return ret; + } + /* + * Unlock of dev->caw_sem to occur in compare_and_write_callback() + * upon MISCOMPARE, or in compare_and_write_done() upon completion + * of WRITE instance user-data. + */ + return TCM_NO_SENSE; +} + +static int +sbc_set_prot_op_checks(u8 protect, bool fabric_prot, enum target_prot_type prot_type, + bool is_write, struct se_cmd *cmd) +{ + if (is_write) { + cmd->prot_op = fabric_prot ? TARGET_PROT_DOUT_STRIP : + protect ? TARGET_PROT_DOUT_PASS : + TARGET_PROT_DOUT_INSERT; + switch (protect) { + case 0x0: + case 0x3: + cmd->prot_checks = 0; + break; + case 0x1: + case 0x5: + cmd->prot_checks = TARGET_DIF_CHECK_GUARD; + if (prot_type == TARGET_DIF_TYPE1_PROT) + cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG; + break; + case 0x2: + if (prot_type == TARGET_DIF_TYPE1_PROT) + cmd->prot_checks = TARGET_DIF_CHECK_REFTAG; + break; + case 0x4: + cmd->prot_checks = TARGET_DIF_CHECK_GUARD; + break; + default: + pr_err("Unsupported protect field %d\n", protect); + return -EINVAL; + } + } else { + cmd->prot_op = fabric_prot ? TARGET_PROT_DIN_INSERT : + protect ? TARGET_PROT_DIN_PASS : + TARGET_PROT_DIN_STRIP; + switch (protect) { + case 0x0: + case 0x1: + case 0x5: + cmd->prot_checks = TARGET_DIF_CHECK_GUARD; + if (prot_type == TARGET_DIF_TYPE1_PROT) + cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG; + break; + case 0x2: + if (prot_type == TARGET_DIF_TYPE1_PROT) + cmd->prot_checks = TARGET_DIF_CHECK_REFTAG; + break; + case 0x3: + cmd->prot_checks = 0; + break; + case 0x4: + cmd->prot_checks = TARGET_DIF_CHECK_GUARD; + break; + default: + pr_err("Unsupported protect field %d\n", protect); + return -EINVAL; + } + } + + return 0; +} + +static sense_reason_t +sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char protect, + u32 sectors, bool is_write) +{ + int sp_ops = cmd->se_sess->sup_prot_ops; + int pi_prot_type = dev->dev_attrib.pi_prot_type; + bool fabric_prot = false; + + if (!cmd->t_prot_sg || !cmd->t_prot_nents) { + if (unlikely(protect && + !dev->dev_attrib.pi_prot_type && !cmd->se_sess->sess_prot_type)) { + pr_err("CDB contains protect bit, but device + fabric does" + " not advertise PROTECT=1 feature bit\n"); + return TCM_INVALID_CDB_FIELD; + } + if (cmd->prot_pto) + return TCM_NO_SENSE; + } + + switch (dev->dev_attrib.pi_prot_type) { + case TARGET_DIF_TYPE3_PROT: + cmd->reftag_seed = 0xffffffff; + break; + case TARGET_DIF_TYPE2_PROT: + if (protect) + return TCM_INVALID_CDB_FIELD; + + cmd->reftag_seed = cmd->t_task_lba; + break; + case TARGET_DIF_TYPE1_PROT: + cmd->reftag_seed = cmd->t_task_lba; + break; + case TARGET_DIF_TYPE0_PROT: + /* + * See if the fabric supports T10-PI, and the session has been + * configured to allow export PROTECT=1 feature bit with backend + * devices that don't support T10-PI. + */ + fabric_prot = is_write ? + !!(sp_ops & (TARGET_PROT_DOUT_PASS | TARGET_PROT_DOUT_STRIP)) : + !!(sp_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DIN_INSERT)); + + if (fabric_prot && cmd->se_sess->sess_prot_type) { + pi_prot_type = cmd->se_sess->sess_prot_type; + break; + } + if (!protect) + return TCM_NO_SENSE; + fallthrough; + default: + pr_err("Unable to determine pi_prot_type for CDB: 0x%02x " + "PROTECT: 0x%02x\n", cmd->t_task_cdb[0], protect); + return TCM_INVALID_CDB_FIELD; + } + + if (sbc_set_prot_op_checks(protect, fabric_prot, pi_prot_type, is_write, cmd)) + return TCM_INVALID_CDB_FIELD; + + cmd->prot_type = pi_prot_type; + cmd->prot_length = dev->prot_length * sectors; + + /** + * In case protection information exists over the wire + * we modify command data length to describe pure data. + * The actual transfer length is data length + protection + * length + **/ + if (protect) + cmd->data_length = sectors * dev->dev_attrib.block_size; + + pr_debug("%s: prot_type=%d, data_length=%d, prot_length=%d " + "prot_op=%d prot_checks=%d\n", + __func__, cmd->prot_type, cmd->data_length, cmd->prot_length, + cmd->prot_op, cmd->prot_checks); + + return TCM_NO_SENSE; +} + +static int +sbc_check_dpofua(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb) +{ + if (cdb[1] & 0x10) { + /* see explanation in spc_emulate_modesense */ + if (!target_check_fua(dev)) { + pr_err("Got CDB: 0x%02x with DPO bit set, but device" + " does not advertise support for DPO\n", cdb[0]); + return -EINVAL; + } + } + if (cdb[1] & 0x8) { + if (!target_check_fua(dev)) { + pr_err("Got CDB: 0x%02x with FUA bit set, but device" + " does not advertise support for FUA write\n", + cdb[0]); + return -EINVAL; + } + cmd->se_cmd_flags |= SCF_FUA; + } + return 0; +} + +sense_reason_t +sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops) +{ + struct se_device *dev = cmd->se_dev; + unsigned char *cdb = cmd->t_task_cdb; + unsigned int size; + u32 sectors = 0; + sense_reason_t ret; + + cmd->protocol_data = ops; + + switch (cdb[0]) { + case READ_6: + sectors = transport_get_sectors_6(cdb); + cmd->t_task_lba = transport_lba_21(cdb); + cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB; + cmd->execute_cmd = sbc_execute_rw; + break; + case READ_10: + sectors = transport_get_sectors_10(cdb); + cmd->t_task_lba = transport_lba_32(cdb); + + if (sbc_check_dpofua(dev, cmd, cdb)) + return TCM_INVALID_CDB_FIELD; + + ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, false); + if (ret) + return ret; + + cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB; + cmd->execute_cmd = sbc_execute_rw; + break; + case READ_12: + sectors = transport_get_sectors_12(cdb); + cmd->t_task_lba = transport_lba_32(cdb); + + if (sbc_check_dpofua(dev, cmd, cdb)) + return TCM_INVALID_CDB_FIELD; + + ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, false); + if (ret) + return ret; + + cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB; + cmd->execute_cmd = sbc_execute_rw; + break; + case READ_16: + sectors = transport_get_sectors_16(cdb); + cmd->t_task_lba = transport_lba_64(cdb); + + if (sbc_check_dpofua(dev, cmd, cdb)) + return TCM_INVALID_CDB_FIELD; + + ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, false); + if (ret) + return ret; + + cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB; + cmd->execute_cmd = sbc_execute_rw; + break; + case WRITE_6: + sectors = transport_get_sectors_6(cdb); + cmd->t_task_lba = transport_lba_21(cdb); + cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB; + cmd->execute_cmd = sbc_execute_rw; + break; + case WRITE_10: + case WRITE_VERIFY: + sectors = transport_get_sectors_10(cdb); + cmd->t_task_lba = transport_lba_32(cdb); + + if (sbc_check_dpofua(dev, cmd, cdb)) + return TCM_INVALID_CDB_FIELD; + + ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, true); + if (ret) + return ret; + + cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB; + cmd->execute_cmd = sbc_execute_rw; + break; + case WRITE_12: + sectors = transport_get_sectors_12(cdb); + cmd->t_task_lba = transport_lba_32(cdb); + + if (sbc_check_dpofua(dev, cmd, cdb)) + return TCM_INVALID_CDB_FIELD; + + ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, true); + if (ret) + return ret; + + cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB; + cmd->execute_cmd = sbc_execute_rw; + break; + case WRITE_16: + case WRITE_VERIFY_16: + sectors = transport_get_sectors_16(cdb); + cmd->t_task_lba = transport_lba_64(cdb); + + if (sbc_check_dpofua(dev, cmd, cdb)) + return TCM_INVALID_CDB_FIELD; + + ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, true); + if (ret) + return ret; + + cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB; + cmd->execute_cmd = sbc_execute_rw; + break; + case VARIABLE_LENGTH_CMD: + { + u16 service_action = get_unaligned_be16(&cdb[8]); + switch (service_action) { + case WRITE_SAME_32: + sectors = transport_get_sectors_32(cdb); + if (!sectors) { + pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not" + " supported\n"); + return TCM_INVALID_CDB_FIELD; + } + + size = sbc_get_size(cmd, 1); + cmd->t_task_lba = get_unaligned_be64(&cdb[12]); + + ret = sbc_setup_write_same(cmd, cdb[10], ops); + if (ret) + return ret; + break; + default: + pr_err("VARIABLE_LENGTH_CMD service action" + " 0x%04x not supported\n", service_action); + return TCM_UNSUPPORTED_SCSI_OPCODE; + } + break; + } + case COMPARE_AND_WRITE: + if (!dev->dev_attrib.emulate_caw) { + pr_err_ratelimited("se_device %s/%s (vpd_unit_serial %s) reject COMPARE_AND_WRITE\n", + dev->se_hba->backend->ops->name, + config_item_name(&dev->dev_group.cg_item), + dev->t10_wwn.unit_serial); + return TCM_UNSUPPORTED_SCSI_OPCODE; + } + sectors = cdb[13]; + /* + * Currently enforce COMPARE_AND_WRITE for a single sector + */ + if (sectors > 1) { + pr_err("COMPARE_AND_WRITE contains NoLB: %u greater" + " than 1\n", sectors); + return TCM_INVALID_CDB_FIELD; + } + if (sbc_check_dpofua(dev, cmd, cdb)) + return TCM_INVALID_CDB_FIELD; + + /* + * Double size because we have two buffers, note that + * zero is not an error.. + */ + size = 2 * sbc_get_size(cmd, sectors); + cmd->t_task_lba = get_unaligned_be64(&cdb[2]); + cmd->t_task_nolb = sectors; + cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB | SCF_COMPARE_AND_WRITE; + cmd->execute_cmd = sbc_compare_and_write; + cmd->transport_complete_callback = compare_and_write_callback; + break; + case READ_CAPACITY: + size = READ_CAP_LEN; + cmd->execute_cmd = sbc_emulate_readcapacity; + break; + case SERVICE_ACTION_IN_16: + switch (cmd->t_task_cdb[1] & 0x1f) { + case SAI_READ_CAPACITY_16: + cmd->execute_cmd = sbc_emulate_readcapacity_16; + break; + case SAI_REPORT_REFERRALS: + cmd->execute_cmd = target_emulate_report_referrals; + break; + default: + pr_err("Unsupported SA: 0x%02x\n", + cmd->t_task_cdb[1] & 0x1f); + return TCM_INVALID_CDB_FIELD; + } + size = get_unaligned_be32(&cdb[10]); + break; + case SYNCHRONIZE_CACHE: + case SYNCHRONIZE_CACHE_16: + if (cdb[0] == SYNCHRONIZE_CACHE) { + sectors = transport_get_sectors_10(cdb); + cmd->t_task_lba = transport_lba_32(cdb); + } else { + sectors = transport_get_sectors_16(cdb); + cmd->t_task_lba = transport_lba_64(cdb); + } + if (ops->execute_sync_cache) { + cmd->execute_cmd = ops->execute_sync_cache; + goto check_lba; + } + size = 0; + cmd->execute_cmd = sbc_emulate_noop; + break; + case UNMAP: + if (!ops->execute_unmap) + return TCM_UNSUPPORTED_SCSI_OPCODE; + + if (!dev->dev_attrib.emulate_tpu) { + pr_err("Got UNMAP, but backend device has" + " emulate_tpu disabled\n"); + return TCM_UNSUPPORTED_SCSI_OPCODE; + } + size = get_unaligned_be16(&cdb[7]); + cmd->execute_cmd = sbc_execute_unmap; + break; + case WRITE_SAME_16: + sectors = transport_get_sectors_16(cdb); + if (!sectors) { + pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n"); + return TCM_INVALID_CDB_FIELD; + } + + size = sbc_get_size(cmd, 1); + cmd->t_task_lba = get_unaligned_be64(&cdb[2]); + + ret = sbc_setup_write_same(cmd, cdb[1], ops); + if (ret) + return ret; + break; + case WRITE_SAME: + sectors = transport_get_sectors_10(cdb); + if (!sectors) { + pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n"); + return TCM_INVALID_CDB_FIELD; + } + + size = sbc_get_size(cmd, 1); + cmd->t_task_lba = get_unaligned_be32(&cdb[2]); + + /* + * Follow sbcr26 with WRITE_SAME (10) and check for the existence + * of byte 1 bit 3 UNMAP instead of original reserved field + */ + ret = sbc_setup_write_same(cmd, cdb[1], ops); + if (ret) + return ret; + break; + case VERIFY: + case VERIFY_16: + size = 0; + if (cdb[0] == VERIFY) { + sectors = transport_get_sectors_10(cdb); + cmd->t_task_lba = transport_lba_32(cdb); + } else { + sectors = transport_get_sectors_16(cdb); + cmd->t_task_lba = transport_lba_64(cdb); + } + cmd->execute_cmd = sbc_emulate_noop; + goto check_lba; + case REZERO_UNIT: + case SEEK_6: + case SEEK_10: + /* + * There are still clients out there which use these old SCSI-2 + * commands. This mainly happens when running VMs with legacy + * guest systems, connected via SCSI command pass-through to + * iSCSI targets. Make them happy and return status GOOD. + */ + size = 0; + cmd->execute_cmd = sbc_emulate_noop; + break; + case START_STOP: + size = 0; + cmd->execute_cmd = sbc_emulate_startstop; + break; + default: + ret = spc_parse_cdb(cmd, &size); + if (ret) + return ret; + } + + /* reject any command that we don't have a handler for */ + if (!cmd->execute_cmd) + return TCM_UNSUPPORTED_SCSI_OPCODE; + + if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) { + unsigned long long end_lba; +check_lba: + end_lba = dev->transport->get_blocks(dev) + 1; + if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) || + ((cmd->t_task_lba + sectors) > end_lba)) { + pr_err("cmd exceeds last lba %llu " + "(lba %llu, sectors %u)\n", + end_lba, cmd->t_task_lba, sectors); + return TCM_ADDRESS_OUT_OF_RANGE; + } + + if (!(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) + size = sbc_get_size(cmd, sectors); + } + + return target_cmd_size_check(cmd, size); +} +EXPORT_SYMBOL(sbc_parse_cdb); + +u32 sbc_get_device_type(struct se_device *dev) +{ + return TYPE_DISK; +} +EXPORT_SYMBOL(sbc_get_device_type); + +static sense_reason_t +sbc_execute_unmap(struct se_cmd *cmd) +{ + struct sbc_ops *ops = cmd->protocol_data; + struct se_device *dev = cmd->se_dev; + unsigned char *buf, *ptr = NULL; + sector_t lba; + int size; + u32 range; + sense_reason_t ret = 0; + int dl, bd_dl; + + /* We never set ANC_SUP */ + if (cmd->t_task_cdb[1]) + return TCM_INVALID_CDB_FIELD; + + if (cmd->data_length == 0) { + target_complete_cmd(cmd, SAM_STAT_GOOD); + return 0; + } + + if (cmd->data_length < 8) { + pr_warn("UNMAP parameter list length %u too small\n", + cmd->data_length); + return TCM_PARAMETER_LIST_LENGTH_ERROR; + } + + buf = transport_kmap_data_sg(cmd); + if (!buf) + return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; + + dl = get_unaligned_be16(&buf[0]); + bd_dl = get_unaligned_be16(&buf[2]); + + size = cmd->data_length - 8; + if (bd_dl > size) + pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n", + cmd->data_length, bd_dl); + else + size = bd_dl; + + if (size / 16 > dev->dev_attrib.max_unmap_block_desc_count) { + ret = TCM_INVALID_PARAMETER_LIST; + goto err; + } + + /* First UNMAP block descriptor starts at 8 byte offset */ + ptr = &buf[8]; + pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u" + " ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr); + + while (size >= 16) { + lba = get_unaligned_be64(&ptr[0]); + range = get_unaligned_be32(&ptr[8]); + pr_debug("UNMAP: Using lba: %llu and range: %u\n", + (unsigned long long)lba, range); + + if (range > dev->dev_attrib.max_unmap_lba_count) { + ret = TCM_INVALID_PARAMETER_LIST; + goto err; + } + + if (lba + range > dev->transport->get_blocks(dev) + 1) { + ret = TCM_ADDRESS_OUT_OF_RANGE; + goto err; + } + + if (range) { + ret = ops->execute_unmap(cmd, lba, range); + if (ret) + goto err; + } + + ptr += 16; + size -= 16; + } + +err: + transport_kunmap_data_sg(cmd); + if (!ret) + target_complete_cmd(cmd, SAM_STAT_GOOD); + return ret; +} + +void +sbc_dif_generate(struct se_cmd *cmd) +{ + struct se_device *dev = cmd->se_dev; + struct t10_pi_tuple *sdt; + struct scatterlist *dsg = cmd->t_data_sg, *psg; + sector_t sector = cmd->t_task_lba; + void *daddr, *paddr; + int i, j, offset = 0; + unsigned int block_size = dev->dev_attrib.block_size; + + for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) { + paddr = kmap_atomic(sg_page(psg)) + psg->offset; + daddr = kmap_atomic(sg_page(dsg)) + dsg->offset; + + for (j = 0; j < psg->length; + j += sizeof(*sdt)) { + __u16 crc; + unsigned int avail; + + if (offset >= dsg->length) { + offset -= dsg->length; + kunmap_atomic(daddr - dsg->offset); + dsg = sg_next(dsg); + if (!dsg) { + kunmap_atomic(paddr - psg->offset); + return; + } + daddr = kmap_atomic(sg_page(dsg)) + dsg->offset; + } + + sdt = paddr + j; + avail = min(block_size, dsg->length - offset); + crc = crc_t10dif(daddr + offset, avail); + if (avail < block_size) { + kunmap_atomic(daddr - dsg->offset); + dsg = sg_next(dsg); + if (!dsg) { + kunmap_atomic(paddr - psg->offset); + return; + } + daddr = kmap_atomic(sg_page(dsg)) + dsg->offset; + offset = block_size - avail; + crc = crc_t10dif_update(crc, daddr, offset); + } else { + offset += block_size; + } + + sdt->guard_tag = cpu_to_be16(crc); + if (cmd->prot_type == TARGET_DIF_TYPE1_PROT) + sdt->ref_tag = cpu_to_be32(sector & 0xffffffff); + sdt->app_tag = 0; + + pr_debug("DIF %s INSERT sector: %llu guard_tag: 0x%04x" + " app_tag: 0x%04x ref_tag: %u\n", + (cmd->data_direction == DMA_TO_DEVICE) ? + "WRITE" : "READ", (unsigned long long)sector, + sdt->guard_tag, sdt->app_tag, + be32_to_cpu(sdt->ref_tag)); + + sector++; + } + + kunmap_atomic(daddr - dsg->offset); + kunmap_atomic(paddr - psg->offset); + } +} + +static sense_reason_t +sbc_dif_v1_verify(struct se_cmd *cmd, struct t10_pi_tuple *sdt, + __u16 crc, sector_t sector, unsigned int ei_lba) +{ + __be16 csum; + + if (!(cmd->prot_checks & TARGET_DIF_CHECK_GUARD)) + goto check_ref; + + csum = cpu_to_be16(crc); + + if (sdt->guard_tag != csum) { + pr_err("DIFv1 checksum failed on sector %llu guard tag 0x%04x" + " csum 0x%04x\n", (unsigned long long)sector, + be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum)); + return TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED; + } + +check_ref: + if (!(cmd->prot_checks & TARGET_DIF_CHECK_REFTAG)) + return 0; + + if (cmd->prot_type == TARGET_DIF_TYPE1_PROT && + be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) { + pr_err("DIFv1 Type 1 reference failed on sector: %llu tag: 0x%08x" + " sector MSB: 0x%08x\n", (unsigned long long)sector, + be32_to_cpu(sdt->ref_tag), (u32)(sector & 0xffffffff)); + return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED; + } + + if (cmd->prot_type == TARGET_DIF_TYPE2_PROT && + be32_to_cpu(sdt->ref_tag) != ei_lba) { + pr_err("DIFv1 Type 2 reference failed on sector: %llu tag: 0x%08x" + " ei_lba: 0x%08x\n", (unsigned long long)sector, + be32_to_cpu(sdt->ref_tag), ei_lba); + return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED; + } + + return 0; +} + +void sbc_dif_copy_prot(struct se_cmd *cmd, unsigned int sectors, bool read, + struct scatterlist *sg, int sg_off) +{ + struct se_device *dev = cmd->se_dev; + struct scatterlist *psg; + void *paddr, *addr; + unsigned int i, len, left; + unsigned int offset = sg_off; + + if (!sg) + return; + + left = sectors * dev->prot_length; + + for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) { + unsigned int psg_len, copied = 0; + + paddr = kmap_atomic(sg_page(psg)) + psg->offset; + psg_len = min(left, psg->length); + while (psg_len) { + len = min(psg_len, sg->length - offset); + addr = kmap_atomic(sg_page(sg)) + sg->offset + offset; + + if (read) + memcpy(paddr + copied, addr, len); + else + memcpy(addr, paddr + copied, len); + + left -= len; + offset += len; + copied += len; + psg_len -= len; + + kunmap_atomic(addr - sg->offset - offset); + + if (offset >= sg->length) { + sg = sg_next(sg); + offset = 0; + } + } + kunmap_atomic(paddr - psg->offset); + } +} +EXPORT_SYMBOL(sbc_dif_copy_prot); + +sense_reason_t +sbc_dif_verify(struct se_cmd *cmd, sector_t start, unsigned int sectors, + unsigned int ei_lba, struct scatterlist *psg, int psg_off) +{ + struct se_device *dev = cmd->se_dev; + struct t10_pi_tuple *sdt; + struct scatterlist *dsg = cmd->t_data_sg; + sector_t sector = start; + void *daddr, *paddr; + int i; + sense_reason_t rc; + int dsg_off = 0; + unsigned int block_size = dev->dev_attrib.block_size; + + for (; psg && sector < start + sectors; psg = sg_next(psg)) { + paddr = kmap_atomic(sg_page(psg)) + psg->offset; + daddr = kmap_atomic(sg_page(dsg)) + dsg->offset; + + for (i = psg_off; i < psg->length && + sector < start + sectors; + i += sizeof(*sdt)) { + __u16 crc; + unsigned int avail; + + if (dsg_off >= dsg->length) { + dsg_off -= dsg->length; + kunmap_atomic(daddr - dsg->offset); + dsg = sg_next(dsg); + if (!dsg) { + kunmap_atomic(paddr - psg->offset); + return 0; + } + daddr = kmap_atomic(sg_page(dsg)) + dsg->offset; + } + + sdt = paddr + i; + + pr_debug("DIF READ sector: %llu guard_tag: 0x%04x" + " app_tag: 0x%04x ref_tag: %u\n", + (unsigned long long)sector, sdt->guard_tag, + sdt->app_tag, be32_to_cpu(sdt->ref_tag)); + + if (sdt->app_tag == T10_PI_APP_ESCAPE) { + dsg_off += block_size; + goto next; + } + + avail = min(block_size, dsg->length - dsg_off); + crc = crc_t10dif(daddr + dsg_off, avail); + if (avail < block_size) { + kunmap_atomic(daddr - dsg->offset); + dsg = sg_next(dsg); + if (!dsg) { + kunmap_atomic(paddr - psg->offset); + return 0; + } + daddr = kmap_atomic(sg_page(dsg)) + dsg->offset; + dsg_off = block_size - avail; + crc = crc_t10dif_update(crc, daddr, dsg_off); + } else { + dsg_off += block_size; + } + + rc = sbc_dif_v1_verify(cmd, sdt, crc, sector, ei_lba); + if (rc) { + kunmap_atomic(daddr - dsg->offset); + kunmap_atomic(paddr - psg->offset); + cmd->sense_info = sector; + return rc; + } +next: + sector++; + ei_lba++; + } + + psg_off = 0; + kunmap_atomic(daddr - dsg->offset); + kunmap_atomic(paddr - psg->offset); + } + + return 0; +} +EXPORT_SYMBOL(sbc_dif_verify); |