#21 zfs

[Anonymous]

Would you access a patch to support ZFS? It would have to be like ZFS, a separate module to get the quota, since it doesn't support the same calls as ext4 or xfs.

[Anonymous]

Sorry, that's "accept" not "access"

[Jan Kara]

I guess it depends how much special ZFS is. If it just means hooking up another syscall for ZFS filesystem I guess that would be OK.

[Anonymous]

The best approach for ZFS is to use libzfs. Of course it's only present on systems that have ZFS.

Code looks like

    zh = zfs_open(libh, filesys, ZFS_TYPE_FILESYSTEM);
    if (!zh) {
      fprintf(stderr, "can't open file systen %s\n", filesys);
      return 0;
    }

    // get the actual quotas

    if (type == USRQUOTA) {
      currspace = getquota("userused", propbuf, sizeof(propbuf)-1, name, libh, zh, &failed);
      if (!failed)
        currfiles = getquota("userobjused", propbuf, sizeof(propbuf)-1, name, libh, zh, &failed);
      if (!failed)
        quotaspace= getquota("userquota", propbuf, sizeof(propbuf)-1, name, libh, zh, &failed);
      if (!failed)
        quotafiles= getquota("userobjquota", propbuf, sizeof(propbuf)-1, name, libh, zh, &failed);
    } else {
      currspace = getquota("groupused", propbuf, sizeof(propbuf)-1, name, libh, zh, &failed);
      if (!failed)
        currfiles = getquota("groupobjused", propbuf, sizeof(propbuf)-1, name, libh, zh, &failed);
      if (!failed)
        quotaspace= getquota("groupquota", propbuf, sizeof(propbuf)-1, name, libh, zh, &failed);
      if (!failed)
        quotafiles= getquota("groupobjquota", propbuf, sizeof(propbuf)-1, name, libh, zh, &failed);
    }

    zfs_close(zh);
    libzfs_fini(libh);

getquota is

unsigned long
getquota(char quota, char propbuf, int propbuflen, char user, libzfs_handle_t libh, zfs_handle_t zh, int failed) {
char *attr = NULL;
unsigned long ret;

asprintf(&attr, "%s@%s", quota, user);
if (!attr) {
*failed = 1;
return 0L;
}

strcpy(propbuf, "0"); // in case no quota for this user
if (zfs_prop_get_userquota(zh, attr, propbuf, propbuflen-1, 1) == 0)
ret = atol(propbuf);
else
ret = 0L;

free(attr);
return ret;
}