lib/zero/zero.c

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