From 8ee83a747ac2309934c229281dda8f26648ec462 Mon Sep 17 00:00:00 2001 From: Andy Grover Date: Fri, 1 May 2015 10:43:45 -0700 Subject: target/user: Disallow full passthrough (pass_level=0) TCMU requires more work to correctly handle both user handlers that want all SCSI commands (pass_level=0) for a se_device, and also handlers that just want I/O commands and let the others be emulated by the kernel (pass_level=1). Only support the latter for now. For full passthrough, we will need to support a second se_subsystem_api template, due to configfs attributes being different between the two modes. Thus pass_level is extraneous, and we can remove it. The ABI break for TCMU v2 is already applied for this release, so it's best to do this now to avoid another ABI break in the future. Signed-off-by: Andy Grover Reviewed-by: Christoph Hellwig Signed-off-by: Nicholas Bellinger --- Documentation/target/tcmu-design.txt | 18 +++++++----------- 1 file changed, 7 insertions(+), 11 deletions(-) (limited to 'Documentation') diff --git a/Documentation/target/tcmu-design.txt b/Documentation/target/tcmu-design.txt index 43e94ea6d2ca..c80bf1ed8981 100644 --- a/Documentation/target/tcmu-design.txt +++ b/Documentation/target/tcmu-design.txt @@ -15,7 +15,7 @@ Contents: a) Discovering and configuring TCMU uio devices b) Waiting for events on the device(s) c) Managing the command ring -3) Command filtering and pass_level +3) Command filtering 4) A final note @@ -360,17 +360,13 @@ int handle_device_events(int fd, void *map) } -Command filtering and pass_level --------------------------------- +Command filtering +----------------- -TCMU supports a "pass_level" option with valid values of 0 or 1. When -the value is 0 (the default), nearly all SCSI commands received for -the device are passed through to the handler. This allows maximum -flexibility but increases the amount of code required by the handler, -to support all mandatory SCSI commands. If pass_level is set to 1, -then only IO-related commands are presented, and the rest are handled -by LIO's in-kernel command emulation. The commands presented at level -1 include all versions of: +Initial TCMU support is for a filtered commandset. Only IO-related +commands are presented to userspace, and the rest are handled by LIO's +in-kernel command emulation. The commands presented are all versions +of: READ WRITE -- cgit v1.2.3 From cf87edc6022d1fe7efa6b8ce1a99f2ef6a1b27f9 Mon Sep 17 00:00:00 2001 From: Andy Grover Date: Tue, 19 May 2015 14:44:38 -0700 Subject: target/user: Update example code for new ABI requirements We now require that the userspace handler set a bit if the command is not handled. Update calls to tcmu_hdr_get_op for v2. Signed-off-by: Andy Grover Reviewed-by: Ilias Tsitsimpis Signed-off-by: Nicholas Bellinger --- Documentation/target/tcmu-design.txt | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'Documentation') diff --git a/Documentation/target/tcmu-design.txt b/Documentation/target/tcmu-design.txt index c80bf1ed8981..b495108c433c 100644 --- a/Documentation/target/tcmu-design.txt +++ b/Documentation/target/tcmu-design.txt @@ -324,7 +324,7 @@ int handle_device_events(int fd, void *map) /* Process events from cmd ring until we catch up with cmd_head */ while (ent != (void *)mb + mb->cmdr_off + mb->cmd_head) { - if (tcmu_hdr_get_op(&ent->hdr) == TCMU_OP_CMD) { + if (tcmu_hdr_get_op(ent->hdr.len_op) == TCMU_OP_CMD) { uint8_t *cdb = (void *)mb + ent->req.cdb_off; bool success = true; @@ -339,8 +339,12 @@ int handle_device_events(int fd, void *map) ent->rsp.scsi_status = SCSI_CHECK_CONDITION; } } + else if (tcmu_hdr_get_op(ent->hdr.len_op) != TCMU_OP_PAD) { + /* Tell the kernel we didn't handle unknown opcodes */ + ent->hdr.uflags |= TCMU_UFLAG_UNKNOWN_OP; + } else { - /* Do nothing for PAD entries */ + /* Do nothing for PAD entries except update cmd_tail */ } /* update cmd_tail */ -- cgit v1.2.3 From 9c1cd1b68cd15c81d12a0cf2402129475882b620 Mon Sep 17 00:00:00 2001 From: Andy Grover Date: Tue, 19 May 2015 14:44:39 -0700 Subject: target/user: Only support full command pass-through After much discussion, give up on only passing a subset of SCSI commands to userspace and pass them all. Based on what pscsi is doing, make sure to set SCF_SCSI_DATA_CDB for I/O ops, and define attributes identical to pscsi. Make hw_block_size configurable via dev param. Remove mention of command filtering from tcmu-design.txt. Signed-off-by: Andy Grover Reviewed-by: Ilias Tsitsimpis Signed-off-by: Nicholas Bellinger --- Documentation/target/tcmu-design.txt | 21 +----- drivers/target/target_core_user.c | 124 +++++++++++++++++++++-------------- 2 files changed, 75 insertions(+), 70 deletions(-) (limited to 'Documentation') diff --git a/Documentation/target/tcmu-design.txt b/Documentation/target/tcmu-design.txt index b495108c433c..263b907517ac 100644 --- a/Documentation/target/tcmu-design.txt +++ b/Documentation/target/tcmu-design.txt @@ -15,8 +15,7 @@ Contents: a) Discovering and configuring TCMU uio devices b) Waiting for events on the device(s) c) Managing the command ring -3) Command filtering -4) A final note +3) A final note TCM Userspace Design @@ -364,24 +363,6 @@ int handle_device_events(int fd, void *map) } -Command filtering ------------------ - -Initial TCMU support is for a filtered commandset. Only IO-related -commands are presented to userspace, and the rest are handled by LIO's -in-kernel command emulation. The commands presented are all versions -of: - -READ -WRITE -WRITE_VERIFY -XDWRITEREAD -WRITE_SAME -COMPARE_AND_WRITE -SYNCHRONIZE_CACHE -UNMAP - - A final note ------------ diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c index 0e0feeaec39c..90e084ea7b92 100644 --- a/drivers/target/target_core_user.c +++ b/drivers/target/target_core_user.c @@ -938,12 +938,13 @@ static void tcmu_free_device(struct se_device *dev) } enum { - Opt_dev_config, Opt_dev_size, Opt_err, + Opt_dev_config, Opt_dev_size, Opt_hw_block_size, Opt_err, }; static match_table_t tokens = { {Opt_dev_config, "dev_config=%s"}, {Opt_dev_size, "dev_size=%u"}, + {Opt_hw_block_size, "hw_block_size=%u"}, {Opt_err, NULL} }; @@ -954,6 +955,7 @@ static ssize_t tcmu_set_configfs_dev_params(struct se_device *dev, char *orig, *ptr, *opts, *arg_p; substring_t args[MAX_OPT_ARGS]; int ret = 0, token; + unsigned long tmp_ul; opts = kstrdup(page, GFP_KERNEL); if (!opts) @@ -986,6 +988,24 @@ static ssize_t tcmu_set_configfs_dev_params(struct se_device *dev, if (ret < 0) pr_err("kstrtoul() failed for dev_size=\n"); break; + case Opt_hw_block_size: + arg_p = match_strdup(&args[0]); + if (!arg_p) { + ret = -ENOMEM; + break; + } + ret = kstrtoul(arg_p, 0, &tmp_ul); + kfree(arg_p); + if (ret < 0) { + pr_err("kstrtoul() failed for hw_block_size=\n"); + break; + } + if (!tmp_ul) { + pr_err("hw_block_size must be nonzero\n"); + break; + } + dev->dev_attrib.hw_block_size = tmp_ul; + break; default: break; } @@ -1016,12 +1036,9 @@ static sector_t tcmu_get_blocks(struct se_device *dev) } static sense_reason_t -tcmu_execute_rw(struct se_cmd *se_cmd, struct scatterlist *sgl, u32 sgl_nents, - enum dma_data_direction data_direction) +tcmu_pass_op(struct se_cmd *se_cmd) { - int ret; - - ret = tcmu_queue_cmd(se_cmd); + int ret = tcmu_queue_cmd(se_cmd); if (ret != 0) return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; @@ -1030,62 +1047,69 @@ tcmu_execute_rw(struct se_cmd *se_cmd, struct scatterlist *sgl, u32 sgl_nents, } static sense_reason_t -tcmu_pass_op(struct se_cmd *se_cmd) +tcmu_parse_cdb(struct se_cmd *cmd) { - int ret = tcmu_queue_cmd(se_cmd); + unsigned char *cdb = cmd->t_task_cdb; - if (ret != 0) - return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; - else + /* + * For REPORT LUNS we always need to emulate the response, for everything + * else, pass it up. + */ + if (cdb[0] == REPORT_LUNS) { + cmd->execute_cmd = spc_emulate_report_luns; return TCM_NO_SENSE; -} + } -static struct sbc_ops tcmu_sbc_ops = { - .execute_rw = tcmu_execute_rw, - .execute_sync_cache = tcmu_pass_op, - .execute_write_same = tcmu_pass_op, - .execute_write_same_unmap = tcmu_pass_op, - .execute_unmap = tcmu_pass_op, -}; + /* Set DATA_CDB flag for ops that should have it */ + switch (cdb[0]) { + case READ_6: + case READ_10: + case READ_12: + case READ_16: + case WRITE_6: + case WRITE_10: + case WRITE_12: + case WRITE_16: + case WRITE_VERIFY: + case WRITE_VERIFY_12: + case 0x8e: /* WRITE_VERIFY_16 */ + case COMPARE_AND_WRITE: + case XDWRITEREAD_10: + cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB; + break; + case VARIABLE_LENGTH_CMD: + switch (get_unaligned_be16(&cdb[8])) { + case READ_32: + case WRITE_32: + case 0x0c: /* WRITE_VERIFY_32 */ + case XDWRITEREAD_32: + cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB; + break; + } + } -static sense_reason_t -tcmu_parse_cdb(struct se_cmd *cmd) -{ - return sbc_parse_cdb(cmd, &tcmu_sbc_ops); + cmd->execute_cmd = tcmu_pass_op; + + return TCM_NO_SENSE; } -DEF_TB_DEFAULT_ATTRIBS(tcmu); +DEF_TB_DEV_ATTRIB_RO(tcmu, hw_pi_prot_type); +TB_DEV_ATTR_RO(tcmu, hw_pi_prot_type); + +DEF_TB_DEV_ATTRIB_RO(tcmu, hw_block_size); +TB_DEV_ATTR_RO(tcmu, hw_block_size); + +DEF_TB_DEV_ATTRIB_RO(tcmu, hw_max_sectors); +TB_DEV_ATTR_RO(tcmu, hw_max_sectors); + +DEF_TB_DEV_ATTRIB_RO(tcmu, hw_queue_depth); +TB_DEV_ATTR_RO(tcmu, hw_queue_depth); static struct configfs_attribute *tcmu_backend_dev_attrs[] = { - &tcmu_dev_attrib_emulate_model_alias.attr, - &tcmu_dev_attrib_emulate_dpo.attr, - &tcmu_dev_attrib_emulate_fua_write.attr, - &tcmu_dev_attrib_emulate_fua_read.attr, - &tcmu_dev_attrib_emulate_write_cache.attr, - &tcmu_dev_attrib_emulate_ua_intlck_ctrl.attr, - &tcmu_dev_attrib_emulate_tas.attr, - &tcmu_dev_attrib_emulate_tpu.attr, - &tcmu_dev_attrib_emulate_tpws.attr, - &tcmu_dev_attrib_emulate_caw.attr, - &tcmu_dev_attrib_emulate_3pc.attr, - &tcmu_dev_attrib_pi_prot_type.attr, &tcmu_dev_attrib_hw_pi_prot_type.attr, - &tcmu_dev_attrib_pi_prot_format.attr, - &tcmu_dev_attrib_enforce_pr_isids.attr, - &tcmu_dev_attrib_is_nonrot.attr, - &tcmu_dev_attrib_emulate_rest_reord.attr, - &tcmu_dev_attrib_force_pr_aptpl.attr, &tcmu_dev_attrib_hw_block_size.attr, - &tcmu_dev_attrib_block_size.attr, &tcmu_dev_attrib_hw_max_sectors.attr, - &tcmu_dev_attrib_optimal_sectors.attr, &tcmu_dev_attrib_hw_queue_depth.attr, - &tcmu_dev_attrib_queue_depth.attr, - &tcmu_dev_attrib_max_unmap_lba_count.attr, - &tcmu_dev_attrib_max_unmap_block_desc_count.attr, - &tcmu_dev_attrib_unmap_granularity.attr, - &tcmu_dev_attrib_unmap_granularity_alignment.attr, - &tcmu_dev_attrib_max_write_same_len.attr, NULL, }; @@ -1094,7 +1118,7 @@ static struct se_subsystem_api tcmu_template = { .inquiry_prod = "USER", .inquiry_rev = TCMU_VERSION, .owner = THIS_MODULE, - .transport_type = TRANSPORT_PLUGIN_VHBA_PDEV, + .transport_type = TRANSPORT_PLUGIN_PHBA_PDEV, .attach_hba = tcmu_attach_hba, .detach_hba = tcmu_detach_hba, .alloc_device = tcmu_alloc_device, -- cgit v1.2.3