libbtrfsutil/qgroup.c

   1 /*
   2  * Copyright (C) 2018 Facebook
   3  *
   4  * This file is part of libbtrfsutil.
   5  *
   6  * libbtrfsutil is free software: you can redistribute it and/or modify
   7  * it under the terms of the GNU Lesser General Public License as published by
   8  * the Free Software Foundation, either version 3 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * libbtrfsutil is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public License
  17  * along with libbtrfsutil.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <errno.h>
  21 #include <stdarg.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24
  25 #include "btrfsutil_internal.h"
  26
  27 PUBLIC enum btrfs_util_error btrfs_util_create_qgroup_inherit(int flags,
  28                                                               struct btrfs_util_qgroup_inherit **ret)
  29 {
  30         struct btrfs_qgroup_inherit *inherit;
  31
  32         if (flags) {
  33                 errno = EINVAL;
  34                 return BTRFS_UTIL_ERROR_INVALID_ARGUMENT;
  35         }
  36
  37         inherit = calloc(1, sizeof(*inherit));
  38         if (!inherit)
  39                 return BTRFS_UTIL_ERROR_NO_MEMORY;
  40
  41         /*
  42          * struct btrfs_util_qgroup_inherit is a lie; it's actually struct
  43          * btrfs_qgroup_inherit, but we abstract it away so that users don't
  44          * need to depend on the Btrfs UAPI headers.
  45          */
  46         *ret = (struct btrfs_util_qgroup_inherit *)inherit;
  47
  48         return BTRFS_UTIL_OK;
  49 }
  50
  51 PUBLIC void btrfs_util_destroy_qgroup_inherit(struct btrfs_util_qgroup_inherit *inherit)
  52 {
  53         free(inherit);
  54 }
  55
  56 PUBLIC enum btrfs_util_error btrfs_util_qgroup_inherit_add_group(struct btrfs_util_qgroup_inherit **inherit,
  57                                                                  uint64_t qgroupid)
  58 {
  59         struct btrfs_qgroup_inherit *tmp = (struct btrfs_qgroup_inherit *)*inherit;
  60
  61         tmp = realloc(tmp, sizeof(*tmp) +
  62                       (tmp->num_qgroups + 1) * sizeof(tmp->qgroups[0]));
  63         if (!tmp)
  64                 return BTRFS_UTIL_ERROR_NO_MEMORY;
  65
  66         tmp->qgroups[tmp->num_qgroups++] = qgroupid;
  67
  68         *inherit = (struct btrfs_util_qgroup_inherit *)tmp;
  69
  70         return BTRFS_UTIL_OK;
  71 }
  72
  73 PUBLIC void btrfs_util_qgroup_inherit_get_groups(const struct btrfs_util_qgroup_inherit *inherit,
  74                                                  const uint64_t **groups,
  75                                                  size_t *n)
  76 {
  77         struct btrfs_qgroup_inherit *tmp = (struct btrfs_qgroup_inherit *)inherit;
  78
  79         /* Need to cast because __u64 != uint64_t. */
  80         *groups = (const uint64_t *)&tmp->qgroups[0];
  81         *n = tmp->num_qgroups;
  82 }