diff options
| -rw-r--r-- | drivers/scsi/qla2xxx/tcm_qla2xxx.c | 5 | ||||
| -rw-r--r-- | drivers/target/target_core_spc.c | 13 | ||||
| -rw-r--r-- | drivers/target/target_core_transport.c | 51 | ||||
| -rw-r--r-- | include/target/target_core_fabric.h | 13 |
4 files changed, 78 insertions, 4 deletions
diff --git a/drivers/scsi/qla2xxx/tcm_qla2xxx.c b/drivers/scsi/qla2xxx/tcm_qla2xxx.c index c621623abeed..edeb3aefa6fe 100644 --- a/drivers/scsi/qla2xxx/tcm_qla2xxx.c +++ b/drivers/scsi/qla2xxx/tcm_qla2xxx.c @@ -1808,6 +1808,11 @@ static const struct target_core_fabric_ops tcm_qla2xxx_ops = { .module = THIS_MODULE, .name = "qla2xxx", .node_acl_size = sizeof(struct tcm_qla2xxx_nacl), + /* + * XXX: Limit assumes single page per scatter-gather-list entry. + * Current maximum is ~4.9 MB per se_cmd->t_data_sg with PAGE_SIZE=4096 + */ + .max_data_sg_nents = 1200, .get_fabric_name = tcm_qla2xxx_get_fabric_name, .tpg_get_wwn = tcm_qla2xxx_get_fabric_wwn, .tpg_get_tag = tcm_qla2xxx_get_tag, diff --git a/drivers/target/target_core_spc.c b/drivers/target/target_core_spc.c index a07d455e0dd5..0e0456f6a282 100644 --- a/drivers/target/target_core_spc.c +++ b/drivers/target/target_core_spc.c @@ -477,8 +477,8 @@ static sense_reason_t spc_emulate_evpd_b0(struct se_cmd *cmd, unsigned char *buf) { struct se_device *dev = cmd->se_dev; - int have_tp = 0; - int opt, min; + u32 mtl = 0; + int have_tp = 0, opt, min; /* * Following spc3r22 section 6.5.3 Block Limits VPD page, when @@ -509,8 +509,15 @@ spc_emulate_evpd_b0(struct se_cmd *cmd, unsigned char *buf) /* * Set MAXIMUM TRANSFER LENGTH + * + * XXX: Currently assumes single PAGE_SIZE per scatterlist for fabrics + * enforcing maximum HW scatter-gather-list entry limit */ - put_unaligned_be32(dev->dev_attrib.hw_max_sectors, &buf[8]); + if (cmd->se_tfo->max_data_sg_nents) { + mtl = (cmd->se_tfo->max_data_sg_nents * PAGE_SIZE) / + dev->dev_attrib.block_size; + } + put_unaligned_be32(min_not_zero(mtl, dev->dev_attrib.hw_max_sectors), &buf[8]); /* * Set OPTIMAL TRANSFER LENGTH diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c index 3f0b50082de4..62bafaa670f4 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -1075,6 +1075,55 @@ transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83) } EXPORT_SYMBOL(transport_set_vpd_ident); +static sense_reason_t +target_check_max_data_sg_nents(struct se_cmd *cmd, struct se_device *dev, + unsigned int size) +{ + u32 mtl; + + if (!cmd->se_tfo->max_data_sg_nents) + return TCM_NO_SENSE; + /* + * Check if fabric enforced maximum SGL entries per I/O descriptor + * exceeds se_cmd->data_length. If true, set SCF_UNDERFLOW_BIT + + * residual_count and reduce original cmd->data_length to maximum + * length based on single PAGE_SIZE entry scatter-lists. + */ + mtl = (cmd->se_tfo->max_data_sg_nents * PAGE_SIZE); + if (cmd->data_length > mtl) { + /* + * If an existing CDB overflow is present, calculate new residual + * based on CDB size minus fabric maximum transfer length. + * + * If an existing CDB underflow is present, calculate new residual + * based on original cmd->data_length minus fabric maximum transfer + * length. + * + * Otherwise, set the underflow residual based on cmd->data_length + * minus fabric maximum transfer length. + */ + if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) { + cmd->residual_count = (size - mtl); + } else if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) { + u32 orig_dl = size + cmd->residual_count; + cmd->residual_count = (orig_dl - mtl); + } else { + cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT; + cmd->residual_count = (cmd->data_length - mtl); + } + cmd->data_length = mtl; + /* + * Reset sbc_check_prot() calculated protection payload + * length based upon the new smaller MTL. + */ + if (cmd->prot_length) { + u32 sectors = (mtl / dev->dev_attrib.block_size); + cmd->prot_length = dev->prot_length * sectors; + } + } + return TCM_NO_SENSE; +} + sense_reason_t target_cmd_size_check(struct se_cmd *cmd, unsigned int size) { @@ -1120,7 +1169,7 @@ target_cmd_size_check(struct se_cmd *cmd, unsigned int size) } } - return 0; + return target_check_max_data_sg_nents(cmd, dev, size); } diff --git a/include/target/target_core_fabric.h b/include/target/target_core_fabric.h index 69355feabd1d..7fb2557a760e 100644 --- a/include/target/target_core_fabric.h +++ b/include/target/target_core_fabric.h @@ -5,6 +5,19 @@ struct target_core_fabric_ops { struct module *module; const char *name; size_t node_acl_size; + /* + * Limits number of scatterlist entries per SCF_SCSI_DATA_CDB payload. + * Setting this value tells target-core to enforce this limit, and + * report as INQUIRY EVPD=b0 MAXIMUM TRANSFER LENGTH. + * + * target-core will currently reset se_cmd->data_length to this + * maximum size, and set UNDERFLOW residual count if length exceeds + * this limit. + * + * XXX: Not all initiator hosts honor this block-limit EVPD + * XXX: Currently assumes single PAGE_SIZE per scatterlist entry + */ + u32 max_data_sg_nents; char *(*get_fabric_name)(void); char *(*tpg_get_wwn)(struct se_portal_group *); u16 (*tpg_get_tag)(struct se_portal_group *); |