target: simplify backend attribute implementation

Consolidate the implementation of the backend attributes in a single file
and single function per attribute show/store function instead of splitting
it into multiple functions in multiple files.

Also use the proper strto* helpers for exposed data types, add macros to
implement the store methods for the most common data types and share the
show methods between the two different attribute implementations.

(Fix bogus store_pi_prot_format flag=0 return value - nab)
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

include/target/target_core_backend.h

@@ -94,35 +94,6 @@ sense_reason_t	transport_generic_map_mem_to_cmd(struct se_cmd *,
 		struct scatterlist *, u32, struct scatterlist *, u32);
 
 bool	target_lun_is_rdonly(struct se_cmd *);
-
-/* attribute helpers from target_core_device.c for backend drivers */
-bool	se_dev_check_wce(struct se_device *);
-int	se_dev_set_max_unmap_lba_count(struct se_device *, u32);
-int	se_dev_set_max_unmap_block_desc_count(struct se_device *, u32);
-int	se_dev_set_unmap_granularity(struct se_device *, u32);
-int	se_dev_set_unmap_granularity_alignment(struct se_device *, u32);
-int	se_dev_set_max_write_same_len(struct se_device *, u32);
-int	se_dev_set_emulate_model_alias(struct se_device *, int);
-int	se_dev_set_emulate_dpo(struct se_device *, int);
-int	se_dev_set_emulate_fua_write(struct se_device *, int);
-int	se_dev_set_emulate_fua_read(struct se_device *, int);
-int	se_dev_set_emulate_write_cache(struct se_device *, int);
-int	se_dev_set_emulate_ua_intlck_ctrl(struct se_device *, int);
-int	se_dev_set_emulate_tas(struct se_device *, int);
-int	se_dev_set_emulate_tpu(struct se_device *, int);
-int	se_dev_set_emulate_tpws(struct se_device *, int);
-int	se_dev_set_emulate_caw(struct se_device *, int);
-int	se_dev_set_emulate_3pc(struct se_device *, int);
-int	se_dev_set_pi_prot_type(struct se_device *, int);
-int	se_dev_set_pi_prot_format(struct se_device *, int);
-int	se_dev_set_enforce_pr_isids(struct se_device *, int);
-int	se_dev_set_force_pr_aptpl(struct se_device *, int);
-int	se_dev_set_is_nonrot(struct se_device *, int);
-int	se_dev_set_emulate_rest_reord(struct se_device *dev, int);
-int	se_dev_set_queue_depth(struct se_device *, u32);
-int	se_dev_set_max_sectors(struct se_device *, u32);
-int	se_dev_set_optimal_sectors(struct se_device *, u32);
-int	se_dev_set_block_size(struct se_device *, u32);
 sense_reason_t passthrough_parse_cdb(struct se_cmd *cmd,
 	sense_reason_t (*exec_cmd)(struct se_cmd *cmd));