external/gpl2/lvm2/dist/lib/zero/zero.c

   1 /*      $NetBSD$        */
   2
   3 /*
   4  * Copyright (C) 2004-2007 Red Hat, Inc. All rights reserved.
   5  *
   6  * This file is part of LVM2.
   7  *
   8  * This copyrighted material is made available to anyone wishing to use,
   9  * modify, copy, or redistribute it subject to the terms and conditions
  10  * of the GNU Lesser General Public License v.2.1.
  11  *
  12  * You should have received a copy of the GNU Lesser General Public License
  13  * along with this program; if not, write to the Free Software Foundation,
  14  * Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  15  */
  16
  17 #include "lib.h"
  18 #include "toolcontext.h"
  19 #include "segtype.h"
  20 #include "display.h"
  21 #include "text_export.h"
  22 #include "text_import.h"
  23 #include "config.h"
  24 #include "str_list.h"
  25 #include "targets.h"
  26 #include "lvm-string.h"
  27 #include "activate.h"
  28 #include "metadata.h"
  29
  30 static const char *_zero_name(const struct lv_segment *seg)
  31 {
  32         return seg->segtype->name;
  33 }
  34
  35 static int _zero_merge_segments(struct lv_segment *seg1, struct lv_segment *seg2)
  36 {
  37         seg1->len += seg2->len;
  38         seg1->area_len += seg2->area_len;
  39
  40         return 1;
  41 }
  42
  43 #ifdef DEVMAPPER_SUPPORT
  44 static int _zero_add_target_line(struct dev_manager *dm __attribute((unused)),
  45                                  struct dm_pool *mem __attribute((unused)),
  46                                  struct cmd_context *cmd __attribute((unused)),
  47                                  void **target_state __attribute((unused)),
  48                                  struct lv_segment *seg __attribute((unused)),
  49                                  struct dm_tree_node *node,uint64_t len,
  50                                  uint32_t *pvmove_mirror_count __attribute((unused)))
  51 {
  52         return dm_tree_node_add_zero_target(node, len);
  53 }
  54
  55 static int _zero_target_present(struct cmd_context *cmd,
  56                                 const struct lv_segment *seg __attribute((unused)),
  57                                 unsigned *attributes __attribute((unused)))
  58 {
  59         static int _zero_checked = 0;
  60         static int _zero_present = 0;
  61
  62         if (!_zero_checked)
  63                 _zero_present = target_present(cmd, "zero", 1);
  64
  65         _zero_checked = 1;
  66
  67         return _zero_present;
  68 }
  69 #endif
  70
  71 static int _zero_modules_needed(struct dm_pool *mem,
  72                                 const struct lv_segment *seg __attribute((unused)),
  73                                 struct dm_list *modules)
  74 {
  75         if (!str_list_add(mem, modules, "zero")) {
  76                 log_error("zero module string list allocation failed");
  77                 return 0;
  78         }
  79
  80         return 1;
  81 }
  82
  83 static void _zero_destroy(const struct segment_type *segtype)
  84 {
  85         dm_free((void *) segtype);
  86 }
  87
  88 static struct segtype_handler _zero_ops = {
  89         .name = _zero_name,
  90         .merge_segments = _zero_merge_segments,
  91 #ifdef DEVMAPPER_SUPPORT
  92         .add_target_line = _zero_add_target_line,
  93         .target_present = _zero_target_present,
  94 #endif
  95         .modules_needed = _zero_modules_needed,
  96         .destroy = _zero_destroy,
  97 };
  98
  99 struct segment_type *init_zero_segtype(struct cmd_context *cmd)
 100 {
 101         struct segment_type *segtype = dm_malloc(sizeof(*segtype));
 102
 103         if (!segtype)
 104                 return_NULL;
 105
 106         segtype->cmd = cmd;
 107         segtype->ops = &_zero_ops;
 108         segtype->name = "zero";
 109         segtype->private = NULL;
 110         segtype->flags = SEG_CAN_SPLIT | SEG_VIRTUAL | SEG_CANNOT_BE_ZEROED;
 111
 112         log_very_verbose("Initialised segtype: %s", segtype->name);
 113
 114         return segtype;
 115 }