scst: Propagate read-only inputs through shared helper interfaces

Declare copied CDB/copy-manager inputs, lookup keys, SGV private-data
access and scalar command inspection inputs read-only. Change
declarations and implementations together, then propagate const through
inquiry, page counting and vector-allocation helpers and their dependent
callers.

Carry the same read-only exclusion command through reset handling and
both unit-attention wrappers. These functions inspect identities or copy
input data; buffer acquisition, release, outputs and registered
callbacks retain their mutable contracts. Installed-header version
generation continues to account for the interface changes.

Cppcheck reports constParameterPointer and constVariablePointer,
including:

  Parameter 'cmd' can be declared as pointer to const
  Parameter 'exclude_cmd' can be declared as pointer to const
  Parameter 'exclude' can be declared as pointer to const

scst/include/scst.h

@@ -3828,11 +3828,11 @@ static inline void scst_sess_set_tgt_priv(struct scst_session *sess, void *val)
 	sess->sess_tgt_priv = val;
 }
 
-u16 scst_lookup_tg_id(struct scst_device *dev, struct scst_tgt *tgt);
-enum scst_tg_state scst_get_alua_state(struct scst_device *dev, struct scst_tgt *tgt);
-bool scst_alua_configured(struct scst_device *dev);
+u16 scst_lookup_tg_id(const struct scst_device *dev, const struct scst_tgt *tgt);
+enum scst_tg_state scst_get_alua_state(const struct scst_device *dev, const struct scst_tgt *tgt);
+bool scst_alua_configured(const struct scst_device *dev);
 int scst_tg_get_group_info(void **buf, u32 *length,
-			   struct scst_device *dev, u8 data_format);
+			   const struct scst_device *dev, u8 data_format);
 int scst_tg_set_group_info(struct scst_cmd *cmd);
 const char *scst_alua_state_name(enum scst_tg_state s);
 void scst_stpg_del_unblock_next(struct scst_cmd *cmd);
@@ -4031,7 +4031,7 @@ static inline unsigned int scst_cmd_get_cdb_len(const struct scst_cmd *cmd)
 }
 
 void scst_cmd_set_ext_cdb(struct scst_cmd *cmd,
-	u8 *ext_cdb, unsigned int ext_cdb_len, gfp_t gfp_mask);
+	const u8 *ext_cdb, unsigned int ext_cdb_len, gfp_t gfp_mask);
 
 /* Returns cmd's session */
 static inline struct scst_session *scst_cmd_get_session(const struct scst_cmd *cmd)
@@ -4488,13 +4488,13 @@ static inline bool scst_cmd_aborted_on_xmit(struct scst_cmd *cmd)
 }
 
 /* Returns sense data format for cmd's dev */
-static inline bool scst_get_cmd_dev_d_sense(struct scst_cmd *cmd)
+static inline bool scst_get_cmd_dev_d_sense(const struct scst_cmd *cmd)
 {
 	return cmd->dev ? cmd->dev->d_sense : 0;
 }
 
 /* Returns if command is INQUIRY EVPD=0x83 (device identification) */
-static inline bool scst_cmd_inquired_dev_ident(struct scst_cmd *cmd)
+static inline bool scst_cmd_inquired_dev_ident(const struct scst_cmd *cmd)
 {
 	return (cmd->cdb[0] == INQUIRY) && ((cmd->cdb[1] & 0x01/*EVPD*/) == 0x01) &&
 		(cmd->cdb[2] == 0x83/*device identification*/);
@@ -5106,7 +5106,7 @@ static inline void scst_put_out_sg_page(struct scst_cmd *cmd, struct page *page,
  * Returns approximate higher rounded buffers count that
  * scst_get_buf_[first|next]() return.
  */
-static inline int scst_get_buf_count(struct scst_cmd *cmd)
+static inline int scst_get_buf_count(const struct scst_cmd *cmd)
 {
 	return (cmd->sg_cnt == 0) ? 1 : cmd->sg_cnt;
 }
@@ -5114,7 +5114,7 @@ static inline int scst_get_buf_count(struct scst_cmd *cmd)
 /*
  * Returns approximate higher rounded buffers count in pages
  */
-static inline int scst_get_buf_page_count(struct scst_cmd *cmd)
+static inline int scst_get_buf_page_count(const struct scst_cmd *cmd)
 {
 	struct scatterlist *sg;
 	int page_cnt = 0, i;
@@ -5132,7 +5132,7 @@ static inline int scst_get_buf_page_count(struct scst_cmd *cmd)
  * Returns approximate higher rounded buffers count that
  * scst_get_out_buf_[first|next]() return.
  */
-static inline int scst_get_out_buf_count(struct scst_cmd *cmd)
+static inline int scst_get_out_buf_count(const struct scst_cmd *cmd)
 {
 	return (cmd->out_sg_cnt == 0) ? 1 : cmd->out_sg_cnt;
 }
@@ -5589,7 +5589,7 @@ extern struct lockdep_map scst_dev_dep_map;
 #endif
 
 char *scst_get_next_lexem(char **token_str);
-void scst_restore_token_str(char *prev_lexem, char *token_str);
+void scst_restore_token_str(char *prev_lexem, const char *token_str);
 char *scst_get_next_token_str(char **input_str);
 
 void scst_init_threads(struct scst_cmd_threads *cmd_threads);
@@ -5733,7 +5733,7 @@ struct scst_ext_copy_seg_descr {
 	int tgt_descr_offs;
 };
 
-void scst_ext_copy_remap_done(struct scst_cmd *ec_cmd, struct scst_ext_copy_data_descr *dds,
+void scst_ext_copy_remap_done(struct scst_cmd *ec_cmd, const struct scst_ext_copy_data_descr *dds,
 			      int dds_cnt);
 int scst_ext_copy_get_cur_seg_data_len(struct scst_cmd *ec_cmd);
 

scst/include/scst_sgv.h

@@ -100,7 +100,7 @@ struct scatterlist *sgv_pool_alloc(struct sgv_pool *pool, unsigned int size,
 	struct sgv_pool_obj **sgv, struct scst_mem_lim *mem_lim, void *priv);
 void sgv_pool_free(struct sgv_pool_obj *obj, struct scst_mem_lim *mem_lim);
 
-void *sgv_get_priv(struct sgv_pool_obj *obj);
+void *sgv_get_priv(const struct sgv_pool_obj *obj);
 
 void scst_init_mem_lim(struct scst_mem_lim *mem_lim);
 

scst/src/dev_handlers/scst_disk.c

@@ -460,7 +460,7 @@ out_complete:
 /* Executes command and split CDB, if necessary */
 static enum scst_exec_res disk_exec(struct scst_cmd *cmd)
 {
-	struct scst_tgt *tgt = cmd->tgt;
+	const struct scst_tgt *tgt = cmd->tgt;
 	enum scst_exec_res res;
 	int rc;
 	struct disk_work work;

scst/src/dev_handlers/scst_vdisk_main.c

@@ -2964,7 +2964,7 @@ static void scst_do_verify_work(struct work_struct *work)
  */
 static bool do_fileio_async(const struct vdisk_cmd_params *p)
 {
-	struct scst_cmd *cmd = p->cmd;
+	const struct scst_cmd *cmd = p->cmd;
 	const struct scst_device *dev = cmd->dev;
 	const struct scst_vdisk_dev *virt_dev = dev->dh_priv;
 
@@ -2979,7 +2979,7 @@ static bool do_fileio_async(const struct vdisk_cmd_params *p)
 	}
 }
 
-static bool vdisk_alloc_async_bvec(struct scst_cmd *cmd,
+static bool vdisk_alloc_async_bvec(const struct scst_cmd *cmd,
 				   struct vdisk_cmd_params *p)
 {
 	int n;
@@ -5010,7 +5010,7 @@ static enum compl_status_e vdisk_exec_prevent_allow_medium_removal(struct vdisk_
 	return CMD_SUCCEEDED;
 }
 
-static struct kvec *vdisk_alloc_sync_kvec(struct scst_cmd *cmd,
+static struct kvec *vdisk_alloc_sync_kvec(const struct scst_cmd *cmd,
 					  struct vdisk_cmd_params *p)
 {
 	int kvec_segs;

scst/src/scst_copy_mgr.c

@@ -1411,7 +1411,7 @@ EXPORT_SYMBOL_GPL(scst_ext_copy_get_cur_seg_data_len);
  * If dds is NULL, then all data have been remapped, so SCST core will switch
  * to the next segment descriptor, if any.
  */
-void scst_ext_copy_remap_done(struct scst_cmd *ec_cmd, struct scst_ext_copy_data_descr *dds,
+void scst_ext_copy_remap_done(struct scst_cmd *ec_cmd, const struct scst_ext_copy_data_descr *dds,
 			      int dds_cnt)
 {
 	TRACE_ENTRY();

scst/src/scst_lib.c

@@ -2487,7 +2487,7 @@ out:
 }
 EXPORT_SYMBOL(scst_check_convert_sense);
 
-int scst_set_cmd_error_sense(struct scst_cmd *cmd, u8 *sense,
+int scst_set_cmd_error_sense(struct scst_cmd *cmd, const u8 *sense,
 	unsigned int len)
 {
 	int res;
@@ -7574,7 +7574,7 @@ EXPORT_SYMBOL(scst_cmd_put);
  * scst_cmd_set_ext_cdb() - sets cmd's extended CDB and its length
  */
 void scst_cmd_set_ext_cdb(struct scst_cmd *cmd,
-	u8 *ext_cdb, unsigned int ext_cdb_len,
+			  const u8 *ext_cdb, unsigned int ext_cdb_len,
 	gfp_t gfp_mask)
 {
 	unsigned int len = cmd->cdb_len + ext_cdb_len;
@@ -13114,7 +13114,7 @@ EXPORT_SYMBOL(scst_to_tgt_dma_dir);
  * !! scst_unblock_aborted_cmds() must be called after this function !!
  */
 void scst_process_reset(struct scst_device *dev,
-	struct scst_session *originator, struct scst_cmd *exclude_cmd,
+	const struct scst_session *originator, const struct scst_cmd *exclude_cmd,
 	struct scst_mgmt_cmd *mcmd, bool setUA)
 {
 	struct scst_tgt_dev *tgt_dev;
@@ -13443,7 +13443,7 @@ void scst_check_set_UA(struct scst_tgt_dev *tgt_dev,
 
 /* Called under dev_lock and BH off */
 void scst_dev_check_set_local_UA(struct scst_device *dev,
-	struct scst_cmd *exclude, const u8 *sense, int sense_len)
+				 const struct scst_cmd *exclude, const u8 *sense, int sense_len)
 {
 	struct scst_tgt_dev *tgt_dev;
 	const struct scst_tgt_dev *exclude_tgt_dev = NULL;
@@ -13467,7 +13467,7 @@ void scst_dev_check_set_local_UA(struct scst_device *dev,
  * should be called outside of the dev_lock.
  */
 static bool __scst_dev_check_set_UA(struct scst_device *dev,
-	struct scst_cmd *exclude, const u8 *sense, int sense_len)
+				    const struct scst_cmd *exclude, const u8 *sense, int sense_len)
 {
 	bool res = false;
 
@@ -13491,7 +13491,7 @@ static bool __scst_dev_check_set_UA(struct scst_device *dev,
 }
 
 void scst_dev_check_set_UA(struct scst_device *dev,
-	struct scst_cmd *exclude, const u8 *sense, int sense_len)
+			   const struct scst_cmd *exclude, const u8 *sense, int sense_len)
 {
 	struct scst_lksb lksb;
 	bool rc;
@@ -14502,7 +14502,7 @@ EXPORT_SYMBOL_GPL(scst_get_next_lexem);
  * previous value before scst_get_next_lexem() was called. Prev_lexem is
  * a pointer to lexem returned by scst_get_next_lexem().
  */
-void scst_restore_token_str(char *prev_lexem, char *token_str)
+void scst_restore_token_str(char *prev_lexem, const char *token_str)
 {
 	if (&prev_lexem[strlen(prev_lexem)] != token_str)
 		prev_lexem[strlen(prev_lexem)] = ' ';

scst/src/scst_local_cmd.c

@@ -249,7 +249,7 @@ out_unlock_put_not_completed:
 /* SPC-4 REPORT TARGET PORT GROUPS command */
 static enum scst_exec_res scst_report_tpgs(struct scst_cmd *cmd)
 {
-	struct scst_device *dev;
+	const struct scst_device *dev;
 	u8 *address;
 	void *buf;
 	s32 buf_len;

scst/src/scst_mem.c

@@ -1114,7 +1114,7 @@ EXPORT_SYMBOL_GPL(sgv_pool_alloc);
  * Allows to get the allocation private data for this SGV
  * cache object. The private data supposed to be set by sgv_pool_alloc().
  */
-void *sgv_get_priv(struct sgv_pool_obj *obj)
+void *sgv_get_priv(const struct sgv_pool_obj *obj)
 {
 	return obj->allocator_priv;
 }

scst/src/scst_priv.h

@@ -386,7 +386,7 @@ struct scst_acn *scst_find_acn(struct scst_acg *acg, const char *name);
 int scst_prepare_request_sense(struct scst_cmd *orig_cmd);
 int scst_finish_internal_cmd(struct scst_cmd *cmd);
 
-int scst_set_cmd_error_sense(struct scst_cmd *cmd, u8 *sense, unsigned int len);
+int scst_set_cmd_error_sense(struct scst_cmd *cmd, const u8 *sense, unsigned int len);
 
 int scst_process_check_condition(struct scst_cmd *cmd);
 
@@ -546,9 +546,9 @@ static inline void scst_clear_dev_reservation(struct scst_device *dev)
 
 void scst_tgt_dev_del_free_UA(struct scst_tgt_dev *tgt_dev,
 			      struct scst_tgt_dev_UA *ua);
-void scst_dev_check_set_UA(struct scst_device *dev, struct scst_cmd *exclude,
+void scst_dev_check_set_UA(struct scst_device *dev, const struct scst_cmd *exclude,
 			   const u8 *sense, int sense_len);
-void scst_dev_check_set_local_UA(struct scst_device *dev, struct scst_cmd *exclude,
+void scst_dev_check_set_local_UA(struct scst_device *dev, const struct scst_cmd *exclude,
 				 const u8 *sense, int sense_len);
 
 #define SCST_SET_UA_FLAG_AT_HEAD	1
@@ -562,8 +562,8 @@ void scst_report_luns_changed(struct scst_acg *acg);
 
 void scst_abort_cmd(struct scst_cmd *cmd, struct scst_mgmt_cmd *mcmd, bool other_ini,
 		    bool call_dev_task_mgmt_fn_received);
-void scst_process_reset(struct scst_device *dev, struct scst_session *originator,
-			struct scst_cmd *exclude_cmd, struct scst_mgmt_cmd *mcmd, bool setUA);
+void scst_process_reset(struct scst_device *dev, const struct scst_session *originator,
+			const struct scst_cmd *exclude_cmd, struct scst_mgmt_cmd *mcmd, bool setUA);
 void __scst_unblock_aborted_cmds(const struct scst_tgt *tgt, const struct scst_session *sess,
 				 const struct scst_device *device);
 void scst_unblock_aborted_cmds(const struct scst_tgt *tgt, const struct scst_session *sess,

scst/src/scst_tg.c

@@ -1452,7 +1452,7 @@ void scst_tg_cleanup(void)
  *
  * Returns a non-zero number if the lookup was successful and zero if not.
  */
-u16 scst_lookup_tg_id(struct scst_device *dev, struct scst_tgt *tgt)
+u16 scst_lookup_tg_id(const struct scst_device *dev, const struct scst_tgt *tgt)
 {
 	struct scst_dev_group *dg;
 	const struct scst_target_group *tg;
@@ -1485,7 +1485,7 @@ EXPORT_SYMBOL_GPL(scst_lookup_tg_id);
  *
  * Returns a valid ALUA state (SCST_TG_STATE_OPTIMIZED is no ALUA configured)
  */
-enum scst_tg_state scst_get_alua_state(struct scst_device *dev, struct scst_tgt *tgt)
+enum scst_tg_state scst_get_alua_state(const struct scst_device *dev, const struct scst_tgt *tgt)
 {
 	struct scst_dev_group *dg;
 	const struct scst_target_group *tg;
@@ -1515,7 +1515,7 @@ EXPORT_SYMBOL_GPL(scst_get_alua_state);
  * scst_alua_configured() - Whether implicit ALUA has been configured.
  * @dev: Pointer to the SCST device to verify.
  */
-bool scst_alua_configured(struct scst_device *dev)
+bool scst_alua_configured(const struct scst_device *dev)
 {
 	struct scst_dev_group *dg;
 
@@ -1535,7 +1535,7 @@ EXPORT_SYMBOL_GPL(scst_alua_configured);
  * @data_format: Three-bit response data format specification.
  */
 int scst_tg_get_group_info(void **buf, u32 *length,
-			   struct scst_device *dev, u8 data_format)
+			   const struct scst_device *dev, u8 data_format)
 {
 	struct scst_dev_group *dg;
 	struct scst_target_group *tg;