[PATCH 1/3] blkid: add UBI volume support

[Corentin Chary]

On Thu, Sep 24, 2009 at 4:14 PM, Karel Zak <kzak at redhat.com> wrote:
> On Mon, Aug 24, 2009 at 01:11:54PM +0200, Corentin Chary wrote:
>> --- a/shlibs/blkid/src/devname.c
>> +static void
>> +ubi_probe_all(blkid_cache cache, int only_if_new)
>> +{
>> +     const char **dirname;
>> +
>> +     for (dirname = dirlist; *dirname; dirname++) {
>> +             DBG(DEBUG_DEVNAME, printf("probing UBI volumes under %s\n",
>> +                                       *dirname));
>> +
>> +             DIR             *dir;
>> +             struct dirent   *iter;
>> +
>> +             dir = opendir(*dirname);
>> +             if (dir == NULL)
>> +                     continue ;
>> +
>> +             while ((iter = readdir(dir)) != NULL) {
>> +                     char            *name, *device;
>> +                     struct stat     st;
>> +                     dev_t           dev;
>> +
>> +                     name = iter->d_name;
>> +
>> +                     if (!strcmp(name, ".") || !strcmp(name, "..") ||
>> +                         !strstr(name, "ubi"))
>> +                             continue;
>> +                     if (!strcmp(name, "ubi_ctrl"))
>> +                             continue;
>> +                     device = malloc(strlen(*dirname) + strlen(name) + 2);
>> +                     if (!device)
>> +                             break ;
>> +                     sprintf(device, "%s/%s", *dirname, name);
>> +                     if (stat(device, &st))
>> +                             break ;
>> +
>> +                     if (!(st.st_rdev & 0xFF)) { // It's an UBI Device
>> +                             free(device);
>> +                             continue ;
>> +                     }
>
> Wouldn't be better to
>
>  #define is_ubi_device(s)    (S_ISCHR(s->st_mode) && (s->st_rdev & 0xFF))
>
> (or major() instead magic 0xFF constant?) and use it everywhere in
> code? I guess UBI is always a char device.

Maybe something like that:
#define is_ubi_device(s)    (S_ISCHR(s->st_mode) && !minor(s->st_rdev))

>> +++ b/shlibs/blkid/src/probe.c
>> @@ -284,6 +284,8 @@ int blkid_probe_set_device(blkid_probe pr, int fd,
>>
>>               if (S_ISBLK(sb.st_mode))
>>                       blkdev_get_size(fd, (unsigned long long *) &pr->size);
>> +             else if (S_ISCHR(sb.st_mode))
>> +                     pr->size = 1;
>>               else
>>                       pr->size = sb.st_size;
>>       }
>
> this is the same situation, this code will for all char devices, but we
> want to support UBI only.

I don't know if there is a "good" way to detect an ubi device using
only struct stat.

Artem, any idea ?

-- 
Corentin Chary
http://xf.iksaif.net