On Mon, 2017-04-24 at 17:39 -0500, Benjamin Marzinski wrote:
> The do_foreach_partmaps code could incorrectly list a device as a
> partition of another device, because of two issues. First, the check
> to
> compare the dm UUID of two devices would allow two partition devices
> to
> match, or a partition device to match with itself, instead of only
> having a partition device match with the multipath device that it
> belongs to. Second, the code to check if a multipath device's
> major:minor appeared in a partition device's table only used strstr
> to check of the existance of the major:minor string. This meant that
> any device with a minor number that started with the same digits
> would
> match. for instance, checking for "253:10" would also match
> "253:102".
Good catch! I missed that in my kpartx series although I was trying to
be paranoid ;-)
> -/*
> - * returns:
> - * 0 : if both uuids end with same suffix which starts with
> UUID_PREFIX
> - * 1 : otherwise
> - */
> -int
> -dm_compare_uuid(const char* mapname1, const char* mapname2)
> +static int
> +is_mpath_part(const char *part_name, const char *map_name)
> {
> - char *p1, *p2;
> - char uuid1[WWID_SIZE], uuid2[WWID_SIZE];
> + char *p;
> + char part_uuid[WWID_SIZE], map_uuid[WWID_SIZE];
>
> - if (dm_get_prefixed_uuid(mapname1, uuid1))
> - return 1;
> + if (dm_get_prefixed_uuid(part_name, part_uuid))
> + return 0;
>
> - if (dm_get_prefixed_uuid(mapname2, uuid2))
> - return 1;
> + if (dm_get_prefixed_uuid(map_name, map_uuid))
> + return 0;
>
> - p1 = strstr(uuid1, UUID_PREFIX);
> - p2 = strstr(uuid2, UUID_PREFIX);
> - if (p1 && p2 && !strcmp(p1, p2))
> + if (strncmp(part_uuid, "part", 4) != 0)
> return 0;
>
> - return 1;
> + p = strstr(part_uuid, UUID_PREFIX);
> + if (p && !strcmp(p, map_uuid))
> + return 1;
> +
> + return 0;
> }
While we've got this far, we might actually implement proper parsing of
the UUID instead of "strstr" which would also match something like
"partially_recovered-mpath...".
ACK nonetheless, further checks can be added on top of this.
Martin
--
Dr. Martin Wilck <mwilck@xxxxxxxx>, Tel. +49 (0)911 74053 2107
SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton
HRB 21284 (AG Nürnberg)
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