On 3/18/21 4:42 AM, Konstantin Shelekhin wrote:
> This commit adds the DUMMY flag to the rd_mcp backend that forces a
> logical unit to report itself as not connected device of an unknown
> type. Essentially this allows users to create devices identical to the
> device for the virtual LUN 0, making it possible to explicitly create a
> LUN 0 device and configure it's WWNs (e.g. vendor or product name).
>
> Signed-off-by: Konstantin Shelekhin <k.shelekhin@xxxxxxxxx>
> Reviewed-by: Roman Bolshakov <r.bolshakov@xxxxxxxxx>
> ---
> drivers/target/target_core_rd.c | 27 +++++++++++++++++++++++----
> drivers/target/target_core_rd.h | 1 +
> 2 files changed, 24 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/target/target_core_rd.c b/drivers/target/target_core_rd.c
> index bf936bbeccfe..cdc5c3bc4b07 100644
> --- a/drivers/target/target_core_rd.c
> +++ b/drivers/target/target_core_rd.c
> @@ -530,12 +530,13 @@ rd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
> }
>
> enum {
> - Opt_rd_pages, Opt_rd_nullio, Opt_err
> + Opt_rd_pages, Opt_rd_nullio, Opt_rd_dummy, Opt_err
> };
>
> static match_table_t tokens = {
> {Opt_rd_pages, "rd_pages=%d"},
> {Opt_rd_nullio, "rd_nullio=%d"},
> + {Opt_rd_dummy, "rd_dummy=%d"},
> {Opt_err, NULL}
> };
>
> @@ -574,6 +575,14 @@ static ssize_t rd_set_configfs_dev_params(struct se_device *dev,
> pr_debug("RAMDISK: Setting NULLIO flag: %d\n", arg);
> rd_dev->rd_flags |= RDF_NULLIO;
> break;
> + case Opt_rd_dummy:
> + match_int(args, &arg);
> + if (arg != 1)
> + break;
> +
> + pr_debug("RAMDISK: Setting DUMMY flag: %d\n", arg);
> + rd_dev->rd_flags |= RDF_DUMMY;
> + break;
> default:
> break;
> }
> @@ -590,12 +599,22 @@ static ssize_t rd_show_configfs_dev_params(struct se_device *dev, char *b)
> ssize_t bl = sprintf(b, "TCM RamDisk ID: %u RamDisk Makeup: rd_mcp\n",
> rd_dev->rd_dev_id);
> bl += sprintf(b + bl, " PAGES/PAGE_SIZE: %u*%lu"
> - " SG_table_count: %u nullio: %d\n", rd_dev->rd_page_count,
> + " SG_table_count: %u nullio: %d dummy: %d\n",
> + rd_dev->rd_page_count,
> PAGE_SIZE, rd_dev->sg_table_count,
> - !!(rd_dev->rd_flags & RDF_NULLIO));
> + !!(rd_dev->rd_flags & RDF_NULLIO),
> + !!(rd_dev->rd_flags & RDF_DUMMY));
> return bl;
> }
>
> +static u32 rd_get_device_type(struct se_device *dev)
> +{
> + if (RD_DEV(dev)->rd_flags & RDF_DUMMY)
> + return 0x3f; /* Unknown device type, not connected */
> + else
> + return TYPE_DISK;
Maybe have this call sbc_get_device_type here so it matches the other drivers
and how this driver calls into lio core for other operations/fields like
parse_cdb or the attrs.
> +}
> +
> static sector_t rd_get_blocks(struct se_device *dev)
> {
> struct rd_dev *rd_dev = RD_DEV(dev);
> @@ -647,7 +666,7 @@ static const struct target_backend_ops rd_mcp_ops = {
> .parse_cdb = rd_parse_cdb,
> .set_configfs_dev_params = rd_set_configfs_dev_params,
> .show_configfs_dev_params = rd_show_configfs_dev_params,
> - .get_device_type = sbc_get_device_type,
> + .get_device_type = rd_get_device_type,
> .get_blocks = rd_get_blocks,
> .init_prot = rd_init_prot,
> .free_prot = rd_free_prot,
> diff --git a/drivers/target/target_core_rd.h b/drivers/target/target_core_rd.h
> index 8b88f9b14c3f..9ffda5c4b584 100644
> --- a/drivers/target/target_core_rd.h
> +++ b/drivers/target/target_core_rd.h
> @@ -28,6 +28,7 @@ struct rd_dev_sg_table {
>
> #define RDF_HAS_PAGE_COUNT 0x01
> #define RDF_NULLIO 0x02
> +#define RDF_DUMMY 0x04
>
> struct rd_dev {
> struct se_device dev;
>
