cifs: avoid extra calls to strlen() in cifs_get_spnego_key()

Since 'snprintf()' returns the number of characters emitted, an
output position may be advanced with this return value rather
than using an explicit calls to 'strlen()'. Compile tested only.

Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Signed-off-by: Steve French <stfrench@microsoft.com>

diff --git a/fs/smb/client/cifs_spnego.c b/fs/smb/client/cifs_spnego.c
index bc1c1e9b288addb8b01b9192c3d8af3cbb1f53ed..43b86fa4d695ca3455e11bf42945e6b61ba668f8 100644 (file)
--- a/fs/smb/client/cifs_spnego.c
+++ b/fs/smb/client/cifs_spnego.c
@@ -124,55 +124,44 @@ cifs_get_spnego_key(struct cifs_ses *sesInfo,
        dp = description;
        /* start with version and hostname portion of UNC string */
        spnego_key = ERR_PTR(-EINVAL);
-       sprintf(dp, "ver=0x%x;host=%s;", CIFS_SPNEGO_UPCALL_VERSION,
-               hostname);
-       dp = description + strlen(description);
+       dp += sprintf(dp, "ver=0x%x;host=%s;", CIFS_SPNEGO_UPCALL_VERSION,
+                     hostname);
 
        /* add the server address */
        if (server->dstaddr.ss_family == AF_INET)
-               sprintf(dp, "ip4=%pI4", &sa->sin_addr);
+               dp += sprintf(dp, "ip4=%pI4", &sa->sin_addr);
        else if (server->dstaddr.ss_family == AF_INET6)
-               sprintf(dp, "ip6=%pI6", &sa6->sin6_addr);
+               dp += sprintf(dp, "ip6=%pI6", &sa6->sin6_addr);
        else
                goto out;
 
-       dp = description + strlen(description);
-
        /* for now, only sec=krb5 and sec=mskrb5 and iakerb are valid */
        if (server->sec_kerberos)
-               sprintf(dp, ";sec=krb5");
+               dp += sprintf(dp, ";sec=krb5");
        else if (server->sec_mskerberos)
-               sprintf(dp, ";sec=mskrb5");
+               dp += sprintf(dp, ";sec=mskrb5");
        else if (server->sec_iakerb)
-               sprintf(dp, ";sec=iakerb");
+               dp += sprintf(dp, ";sec=iakerb");
        else {
                cifs_dbg(VFS, "unknown or missing server auth type, use krb5\n");
-               sprintf(dp, ";sec=krb5");
+               dp += sprintf(dp, ";sec=krb5");
        }
 
-       dp = description + strlen(description);
-       sprintf(dp, ";uid=0x%x",
-               from_kuid_munged(&init_user_ns, sesInfo->linux_uid));
+       dp += sprintf(dp, ";uid=0x%x",
+                     from_kuid_munged(&init_user_ns, sesInfo->linux_uid));
 
-       dp = description + strlen(description);
-       sprintf(dp, ";creduid=0x%x",
+       dp += sprintf(dp, ";creduid=0x%x",
                from_kuid_munged(&init_user_ns, sesInfo->cred_uid));
 
-       if (sesInfo->user_name) {
-               dp = description + strlen(description);
-               sprintf(dp, ";user=%s", sesInfo->user_name);
-       }
+       if (sesInfo->user_name)
+               dp += sprintf(dp, ";user=%s", sesInfo->user_name);
 
-       dp = description + strlen(description);
-       sprintf(dp, ";pid=0x%x", current->pid);
+       dp += sprintf(dp, ";pid=0x%x", current->pid);
 
-       if (sesInfo->upcall_target == UPTARGET_MOUNT) {
-               dp = description + strlen(description);
-               sprintf(dp, ";upcall_target=mount");
-       } else {
-               dp = description + strlen(description);
-               sprintf(dp, ";upcall_target=app");
-       }
+       if (sesInfo->upcall_target == UPTARGET_MOUNT)
+               dp += sprintf(dp, ";upcall_target=mount");
+       else
+               dp += sprintf(dp, ";upcall_target=app");
 
        cifs_dbg(FYI, "key description = %s\n", description);
        saved_cred = override_creds(spnego_cred);