scst: Replace zero-length arrays with flexible-array members

There is a regular need in the kernel to provide a way to declare
having a dynamically sized set of trailing elements in a structure.
Kernel code should always use “flexible array members”[1] for these
cases. The older style of one-element or zero-length arrays should
no longer be used[2].

This code was transformed with the help of Coccinelle:
($ spatch --jobs $(getconf _NPROCESSORS_ONLN) --sp-file script.cocci --include-headers --dir . > output.patch)

@@
identifier S, member, array;
type T1, T2;
@@

struct S {
  ...
  T1 member;
  T2 array[
- 0
  ];
};

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-length-and-one-element-arrays

Link: https://github.com/KSPP/linux/issues/78

iscsi-scst/usr/iscsid.h

@@ -52,7 +52,7 @@ struct buf_segment {
 	struct __qelem entry;
 
 	unsigned int len;
-	char data[0];
+	char data[];
 };
 
 struct PDU {

iscsi-scst/usr/isns_proto.h

@@ -32,7 +32,7 @@ struct isns_hdr {
 	uint16_t flags;
 	uint16_t transaction;
 	uint16_t sequence;
-	uint32_t pdu[0];
+	uint32_t pdu[];
 } __attribute__ ((packed));
 
 struct isns_tlv {

qla2x00t-32gbit/qla_bsg.h

@@ -157,7 +157,7 @@ struct qla84_msg_mgmt {
 	uint16_t rsrvd;
 	struct qla84_mgmt_param mgmtp;/* parameters for cmd */
 	uint32_t len; /* bytes in payload following this struct */
-	uint8_t payload[0]; /* payload for cmd */
+	uint8_t payload[]; /* payload for cmd */
 };
 
 struct qla_bsg_a84_mgmt {
@@ -216,7 +216,7 @@ struct qla_image_version {
 
 struct qla_image_version_list {
 	uint32_t count;
-	struct qla_image_version version[0];
+	struct qla_image_version version[];
 } __packed;
 
 struct qla_status_reg {

qla2x00t-32gbit/qla_def.h

@@ -5456,7 +5456,7 @@ struct ql_vnd_stat_entry {
 struct ql_vnd_stats {
 	u64 entry_count; /* Num of entries */
 	u64 rservd;
-	struct ql_vnd_stat_entry entry[0]; /* Place holder of entries */
+	struct ql_vnd_stat_entry entry[]; /* Place holder of entries */
 } __packed;
 
 struct ql_vnd_host_stats_resp {

qla2x00t-32gbit/qla_edif_bsg.h

@@ -121,7 +121,7 @@ struct app_pinfo {
 struct app_pinfo_reply {
 	uint8_t		port_count;
 	uint8_t		reserved[VND_CMD_APP_RESERVED_SIZE];
-	struct app_pinfo ports[0];
+	struct app_pinfo ports[];
 } __packed;
 
 struct app_sinfo_req {
@@ -140,7 +140,7 @@ struct app_sinfo {
 
 struct app_stats_reply {
 	uint8_t		elem_count;
-	struct app_sinfo elem[0];
+	struct app_sinfo elem[];
 } __packed;
 
 struct qla_sa_update_frame {

qla2x00t-32gbit/qla_fw.h

@@ -1716,7 +1716,7 @@ struct qla_flt_header {
 	__le16	length;
 	__le16	checksum;
 	__le16	unused;
-	struct qla_flt_region region[0];
+	struct qla_flt_region region[];
 };
 
 #define FLT_REGION_SIZE		16

qla2x00t/qla_bsg.h

@@ -121,7 +121,7 @@ struct qla84_msg_mgmt {
 	uint16_t rsrvd;
 	struct qla84_mgmt_param mgmtp;/* parameters for cmd */
 	uint32_t len; /* bytes in payload following this struct */
-	uint8_t payload[0]; /* payload for cmd */
+	uint8_t payload[]; /* payload for cmd */
 };
 
 struct qla_bsg_a84_mgmt {

scst/include/scst_event.h

@@ -149,7 +149,7 @@ struct scst_event_stpg_payload {
 	aligned_u64 stpg_cmd_tag;
 	uint8_t device_name[64];
 	uint16_t stpg_descriptors_cnt;
-	struct scst_event_stpg_descr stpg_descriptors[0];
+	struct scst_event_stpg_descr stpg_descriptors[];
 };
 
 #define SCST_EVENT_REG_VIRT_DEV		6

scst/include/scst_user.h

@@ -354,7 +354,7 @@ struct scst_user_get_multi {
 	int16_t replies_done; /* out */
 	int16_t cmds_cnt; /* in/out */
 	int16_t pad;
-	struct scst_user_get_cmd cmds[0]; /* out */
+	struct scst_user_get_cmd cmds[]; /* out */
 };
 
 #define SCST_USER_REGISTER_DEVICE	_IOW('u', 1, struct scst_user_dev_desc)

scst/src/scst_mem.h

@@ -50,7 +50,7 @@ struct sgv_pool_obj {
 	void *allocator_priv;
 	struct trans_tbl_ent *trans_tbl;
 	struct scatterlist *sg_entries;
-	struct scatterlist sg_entries_data[0];
+	struct scatterlist sg_entries_data[];
 };
 
 /*