[Libvir] [PATCH] Rewrite openvzSetUUID.

[Jim Meyering]

Jim Paris <jim at jtan.com> wrote:

> Jim Meyering wrote:
>> +	/* Record failure if any of these fails,
>> +	   and be careful always to close the stream.  */
>> +	if ((fseek(fp, 0, SEEK_END) < 0)
>> +	    + (fprintf(fp, "\n#UUID: %s\n", uuidstr) < 0);
>> +	    + (fclose(fp) == EOF))
>> +	    ret = -1;
>
> I don't think you want to fprintf() if the fseek() fails?

Good catch.  Thanks.
I've fixed it this way.

[Hmm.. normally I would have saved and restored errno around the unchecked
fclose call, but I see that the sole caller of openvzSetUUID always
ignores this function's return value.  Sigh... ]

diff --git a/src/openvz_conf.c b/src/openvz_conf.c
index a274223..f0f579a 100644
--- a/src/openvz_conf.c
+++ b/src/openvz_conf.c
@@ -680,7 +680,6 @@ openvzSetUUID(int vpsid)
     char uuidstr[VIR_UUID_STRING_BUFLEN];
     unsigned char uuid[VIR_UUID_BUFLEN];
     char *conf_dir;
-    int fd, ret;

     conf_dir = openvzLocateConfDir();
     if (conf_dir == NULL)
@@ -688,23 +687,27 @@ openvzSetUUID(int vpsid)
     sprintf(conf_file, "%s/%d.conf", conf_dir, vpsid);
     free(conf_dir);

-    fd = open(conf_file, O_RDWR);
-    if(fd == -1)
+    if (openvzGetVPSUUID(vpsid, uuidstr))
         return -1;

-    ret = openvzGetVPSUUID(vpsid, uuidstr);
-    if(ret == -1)
-        return -1;
+    if (uuidstr[0] == 0) {
+	FILE *fp = fopen(conf_file, "a");
+	if (fp == NULL)
+	  return -1;

-    if(uuidstr[0] == 0) {
         virUUIDGenerate(uuid);
         virUUIDFormat(uuid, uuidstr);

-        lseek(fd, 0, SEEK_END);
-        write(fd, "\n#UUID: ", 8);
-        write(fd, uuidstr, strlen(uuidstr));
-        write(fd, "\n", 1);
-        close(fd);
+	/* Record failure if fseek, fprintf or fclose fails,
+	   and be careful always to close the stream.  */
+	if (fseek(fp, 0, SEEK_END) < 0) {
+	    fclose(fp);
+	    return -1;
+	}
+
+	if ((fprintf(fp, "\n#UUID: %s\n", uuidstr) < 0)
+	    + (fclose(fp) == EOF))
+	    return -1;
     }

     return 0;
--
1.5.4.2.134.g82883