cifs: create a define for how many iovs we need for an SMB2_open()

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/cifs/smb2ops.c

@@ -1582,7 +1582,7 @@ smb2_queryfs(const unsigned int xid, struct cifs_tcon *tcon,
 	struct smb_rqst rqst[3];
 	int resp_buftype[3];
 	struct kvec rsp_iov[3];
-	struct kvec open_iov[5]; /* 4 + potential padding. */
+	struct kvec open_iov[SMB2_CREATE_IOV_SIZE];
 	struct kvec qi_iov[1];
 	struct kvec close_iov[1];
 	struct cifs_ses *ses = tcon->ses;
@@ -1603,7 +1603,7 @@ smb2_queryfs(const unsigned int xid, struct cifs_tcon *tcon,
 
 	memset(&open_iov, 0, sizeof(open_iov));
 	rqst[0].rq_iov = open_iov;
-	rqst[0].rq_nvec = 4;
+	rqst[0].rq_nvec = SMB2_CREATE_IOV_SIZE;
 
 	oparms.tcon = tcon;
 	oparms.desired_access = FILE_READ_ATTRIBUTES;

fs/cifs/smb2pdu.c

@@ -2256,7 +2256,7 @@ SMB2_open(const unsigned int xid, struct cifs_open_parms *oparms, __le16 *path,
 	struct TCP_Server_Info *server;
 	struct cifs_tcon *tcon = oparms->tcon;
 	struct cifs_ses *ses = tcon->ses;
-	struct kvec iov[5]; /* make sure at least one for each open context */
+	struct kvec iov[SMB2_CREATE_IOV_SIZE];
 	struct kvec rsp_iov = {NULL, 0};
 	int resp_buftype;
 	int rc = 0;
@@ -2274,7 +2274,7 @@ SMB2_open(const unsigned int xid, struct cifs_open_parms *oparms, __le16 *path,
 	memset(&rqst, 0, sizeof(struct smb_rqst));
 	memset(&iov, 0, sizeof(iov));
 	rqst.rq_iov = iov;
-	rqst.rq_nvec = 5;
+	rqst.rq_nvec = SMB2_CREATE_IOV_SIZE;
 
 	rc = SMB2_open_init(tcon, &rqst, oplock, oparms, path);
 	if (rc)

fs/cifs/smb2pdu.h

@@ -614,6 +614,18 @@ struct smb2_tree_disconnect_rsp {
 #define SMB2_CREATE_TAG_POSIX		0x93AD25509CB411E7B42383DE968BCD7C
 
 
+/*
+ * Maximum number of iovs we need for an open/create request.
+ * [0] : struct smb2_create_req
+ * [1] : path
+ * [2] : lease context
+ * [3] : durable context
+ * [4] : posix context
+ * [5] : time warp context
+ * [6] : compound padding
+ */
+#define SMB2_CREATE_IOV_SIZE 7
+
 struct smb2_create_req {
 	struct smb2_sync_hdr sync_hdr;
 	__le16 StructureSize;	/* Must be 57 */