@@ -46,11 +46,11 @@ format_devname(char *name, int id, int len, char *prefix)
memset(name,0, len);
strcpy(name, prefix);
for (pos = len - 1; pos >= prefix_len; pos--) {
+ id--;
name[pos] = 'a' + id % 26;
if (id < 26)
break;
id /= 26;
- id--;
}
memmove(name + prefix_len, name + pos, len - pos);
name[prefix_len + len - pos] = '\0';
@@ -66,13 +66,22 @@ scan_devname(char *alias, char *prefix)
if (!prefix || strncmp(alias, prefix, strlen(prefix)))
return -1;
+ if (strlen(alias) == strlen(prefix))
+ return -1;
+
+ if (strlen(alias) > strlen(prefix) + 7)
+ /* id of 'aaaaaaaa' overflows int */
+ return -1;
+
c = alias + strlen(prefix);
while (*c != '\0' && *c != ' ' && *c != '\t') {
+ if (*c < 'a' || *c > 'z')
+ return -1;
i = *c - 'a';
n = ( n * 26 ) + i;
+ if (n < 0)
+ return -1;
c++;
- if (*c < 'a' || *c > 'z')
- break;
n++;
}
@@ -84,7 +93,9 @@ lookup_binding(FILE *f, char *map_wwid, char **map_alias, char *prefix)
{
char buf[LINE_MAX];
unsigned int line_nr = 0;
- int id = 0;
+ int id = 1;
+ int biggest_id = 1;
+ int smallest_bigger_id = INT_MAX;
*map_alias = NULL;
@@ -100,8 +111,12 @@ lookup_binding(FILE *f, char *map_wwid, char **map_alias, char *prefix)
if (!alias) /* blank line */
continue;
curr_id = scan_devname(alias, prefix);
- if (curr_id >= id)
- id = curr_id + 1;
+ if (curr_id == id)
+ id++;
+ if (curr_id > biggest_id)
+ biggest_id = curr_id;
+ if (curr_id > id && curr_id < smallest_bigger_id)
+ smallest_bigger_id = curr_id;
wwid = strtok(NULL, " \t");
if (!wwid){
condlog(3,
@@ -116,11 +131,17 @@ lookup_binding(FILE *f, char *map_wwid, char **map_alias, char *prefix)
if (*map_alias == NULL)
condlog(0, "Cannot copy alias from bindings "
"file : %s", strerror(errno));
- return id;
+ return 0;
}
}
condlog(3, "No matching wwid [%s] in bindings file.", map_wwid);
- return id;
+ if (id < 0) {
+ condlog(0, "no more available user_friendly_names");
+ return 0;
+ }
+ if (id < smallest_bigger_id)
+ return id;
+ return biggest_id + 1;
}
static int
@@ -254,7 +275,7 @@ get_user_friendly_alias(char *wwid, char *file, char *prefix,
return NULL;
}
- if (!alias && can_write && !bindings_read_only)
+ if (!alias && can_write && !bindings_read_only && id)
alias = allocate_binding(fd, wwid, id, prefix);
fclose(f);
Unfortunately, instead of adding aliases to /etc/multipath.conf like they should, some users add aliases to the bindings file. If they add aliases that look like user_friendly_names, like mpathfoo, they interfere with the code to find the next available user_friendly_name (giving you mpathfop as the next user_friendly_name in this case). This patch will fix this by giving the next name available name after an unbroken string of names starting with the smallest possible name. It order to keep the choice quick, it won't handle situation where the list of names starting at the smallest possible is not in order. There are a number of ways to do a better job finding the smallest possible name, but this will fix most of the cases I've seen, without slowing things down at all. Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> --- libmultipath/alias.c | 39 ++++++++++++++++++++++++++++++--------- 1 file changed, 30 insertions(+), 9 deletions(-)