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 <agrover@redhat.com>
Reviewed-by: Ilias Tsitsimpis <iliastsi@arrikto.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

2 files changed, 75 insertions, 70 deletions

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,