smb: move create_durable_reconn to common/smb2pdu.h

The fields in struct create_durable_reconn_req and struct create_durable
are exactly the same, so remove create_durable_reconn_req from server,
and use typedef to define both create_durable_req_t and
create_durable_reconn_t for a single struct.

Rename the following places:

- struct create_durable -> create_durable_req_t
- struct create_durable_reconn_req -> create_durable_reconn_t

The documentation references are:

- SMB2_CREATE_DURABLE_HANDLE_REQUEST in MS-SMB2 2.2.13.2.3
- SMB2_CREATE_DURABLE_HANDLE_RECONNECT in MS-SMB2 2.2.13.2.4
- SMB2_FILEID in MS-SMB2 2.2.14.1

Descriptions of the struct fields:

- __u8 Reserved[16]: DurableRequest field of SMB2_CREATE_DURABLE_HANDLE_REQUEST.
A 16-byte field that MUST be reserved.
- __u64 PersistentFileId: Persistent field of 2.2.14.1 SMB2_FILEID
- __u64 VolatileFileId: Volatile field of 2.2.14.1 SMB2_FILEID
- struct Fid: Data field of SMB2_CREATE_DURABLE_HANDLE_RECONNECT.
An SMB2_FILEID structure, as specified in section 2.2.14.1.

Suggested-by: Namjae Jeon <[e-mail]>
Signed-off-by: ChenXiaoSong <[e-mail]>
Acked-by: Namjae Jeon <[e-mail]>
Signed-off-by: Steve French <[e-mail]>

fs/smb/client/smb2pdu.c

···
 	return rc;
 }
 
-
-static struct create_durable *
+static create_durable_req_t *
 create_durable_buf(void)
 {
-	struct create_durable *buf;
+	create_durable_req_t *buf;
 
-	buf = kzalloc(sizeof(struct create_durable), GFP_KERNEL);
+	buf = kzalloc(sizeof(create_durable_req_t), GFP_KERNEL);
 	if (!buf)
 		return NULL;
 
 	buf->ccontext.DataOffset = cpu_to_le16(offsetof
-					(struct create_durable, Data));
+					(create_durable_req_t, Data));
 	buf->ccontext.DataLength = cpu_to_le32(16);
 	buf->ccontext.NameOffset = cpu_to_le16(offsetof
-				(struct create_durable, Name));
+				(create_durable_req_t, Name));
 	buf->ccontext.NameLength = cpu_to_le16(4);
 	/* SMB2_CREATE_DURABLE_HANDLE_REQUEST is "DHnQ" */
 	buf->Name[0] = 'D';
···
 	return buf;
 }
 
-static struct create_durable *
+static create_durable_req_t *
 create_reconnect_durable_buf(struct cifs_fid *fid)
 {
-	struct create_durable *buf;
+	create_durable_req_t *buf;
 
-	buf = kzalloc(sizeof(struct create_durable), GFP_KERNEL);
+	buf = kzalloc(sizeof(create_durable_req_t), GFP_KERNEL);
 	if (!buf)
 		return NULL;
 
 	buf->ccontext.DataOffset = cpu_to_le16(offsetof
-					(struct create_durable, Data));
+					(create_durable_req_t, Data));
 	buf->ccontext.DataLength = cpu_to_le32(16);
 	buf->ccontext.NameOffset = cpu_to_le16(offsetof
-				(struct create_durable, Name));
+				(create_durable_req_t, Name));
 	buf->ccontext.NameLength = cpu_to_le16(4);
 	buf->Data.Fid.PersistentFileId = fid->persistent_fid;
 	buf->Data.Fid.VolatileFileId = fid->volatile_fid;
···
 		iov[num].iov_base = create_durable_buf();
 	if (iov[num].iov_base == NULL)
 		return -ENOMEM;
-	iov[num].iov_len = sizeof(struct create_durable);
+	iov[num].iov_len = sizeof(create_durable_req_t);
 	*num_iovec = num + 1;
 	return 0;
 }

fs/smb/common/smb2pdu.h

···
 } __packed;
 
 /* See MS-SMB2 2.2.13.2.3 and MS-SMB2 2.2.13.2.4 */
-struct create_durable {
+typedef struct {
 	struct create_context_hdr ccontext;
 	__u8   Name[8];
 	union {
···
 			__u64 VolatileFileId;
 		} Fid;
 	} Data;
-} __packed;
+} __packed create_durable_req_t, create_durable_reconn_t;
 
 /* See MS-SMB2 2.2.13.2.5 */
 struct create_mxac_req {

fs/smb/server/smb2pdu.c

···
 		}
 		case DURABLE_RECONN:
 		{
-			struct create_durable_reconn_req *recon;
+			create_durable_reconn_t *recon;
 
 			if (dh_info->type == DURABLE_RECONN_V2 ||
 			    dh_info->type == DURABLE_REQ_V2) {
···
 
 			if (le16_to_cpu(context->DataOffset) +
 				le32_to_cpu(context->DataLength) <
-			    sizeof(struct create_durable_reconn_req)) {
+			    sizeof(create_durable_reconn_t)) {
 				err = -EINVAL;
 				goto out;
 			}
 
-			recon = (struct create_durable_reconn_req *)context;
+			recon = (create_durable_reconn_t *)context;
 			persistent_id = recon->Data.Fid.PersistentFileId;
 			dh_info->fp = ksmbd_lookup_durable_fd(persistent_id);
 			if (!dh_info->fp) {

fs/smb/server/smb2pdu.h

···
 
 #define DURABLE_HANDLE_MAX_TIMEOUT	300000
 
-struct create_durable_reconn_req {
-	struct create_context_hdr ccontext;
-	__u8   Name[8];
-	union {
-		__u8  Reserved[16];
-		struct {
-			__u64 PersistentFileId;
-			__u64 VolatileFileId;
-		} Fid;
-	} Data;
-} __packed;
-
 struct create_alloc_size_req {
 	struct create_context_hdr ccontext;
 	__u8   Name[8];