fs/reiser4/plugin/item/blackbox.c

   1 /* Copyright 2003 by Hans Reiser, licensing governed by
   2  * reiser4/README */
   3
   4 /* Black box item implementation */
   5
   6 #include "../../forward.h"
   7 #include "../../debug.h"
   8 #include "../../dformat.h"
   9 #include "../../kassign.h"
  10 #include "../../coord.h"
  11 #include "../../tree.h"
  12 #include "../../lock.h"
  13
  14 #include "blackbox.h"
  15 #include "item.h"
  16 #include "../plugin.h"
  17
  18 int
  19 store_black_box(reiser4_tree * tree,
  20                 const reiser4_key * key, void *data, int length)
  21 {
  22         int result;
  23         reiser4_item_data idata;
  24         coord_t coord;
  25         lock_handle lh;
  26
  27         memset(&idata, 0, sizeof idata);
  28
  29         idata.data = data;
  30         idata.user = 0;
  31         idata.length = length;
  32         idata.iplug = item_plugin_by_id(BLACK_BOX_ID);
  33
  34         init_lh(&lh);
  35         result = insert_by_key(tree, key,
  36                                &idata, &coord, &lh, LEAF_LEVEL, CBK_UNIQUE);
  37
  38         assert("nikita-3413",
  39                ergo(result == 0,
  40                     WITH_COORD(&coord,
  41                                item_length_by_coord(&coord) == length)));
  42
  43         done_lh(&lh);
  44         return result;
  45 }
  46
  47 int
  48 load_black_box(reiser4_tree * tree,
  49                reiser4_key * key, void *data, int length, int exact)
  50 {
  51         int result;
  52         coord_t coord;
  53         lock_handle lh;
  54
  55         init_lh(&lh);
  56         result = coord_by_key(tree, key,
  57                               &coord, &lh, ZNODE_READ_LOCK,
  58                               exact ? FIND_EXACT : FIND_MAX_NOT_MORE_THAN,
  59                               LEAF_LEVEL, LEAF_LEVEL, CBK_UNIQUE, NULL);
  60
  61         if (result == 0) {
  62                 int ilen;
  63
  64                 result = zload(coord.node);
  65                 if (result == 0) {
  66                         ilen = item_length_by_coord(&coord);
  67                         if (ilen <= length) {
  68                                 memcpy(data, item_body_by_coord(&coord), ilen);
  69                                 unit_key_by_coord(&coord, key);
  70                         } else if (exact) {
  71                                 /*
  72                                  * item is larger than buffer provided by the
  73                                  * user. Only issue a warning if @exact is
  74                                  * set. If @exact is false, we are iterating
  75                                  * over all safe-links and here we are reaching
  76                                  * the end of the iteration.
  77                                  */
  78                                 warning("nikita-3415",
  79                                         "Wrong black box length: %i > %i",
  80                                         ilen, length);
  81                                 result = RETERR(-EIO);
  82                         }
  83                         zrelse(coord.node);
  84                 }
  85         }
  86
  87         done_lh(&lh);
  88         return result;
  89
  90 }
  91
  92 int
  93 update_black_box(reiser4_tree * tree,
  94                  const reiser4_key * key, void *data, int length)
  95 {
  96         int result;
  97         coord_t coord;
  98         lock_handle lh;
  99
 100         init_lh(&lh);
 101         result = coord_by_key(tree, key,
 102                               &coord, &lh, ZNODE_READ_LOCK,
 103                               FIND_EXACT,
 104                               LEAF_LEVEL, LEAF_LEVEL, CBK_UNIQUE, NULL);
 105         if (result == 0) {
 106                 int ilen;
 107
 108                 result = zload(coord.node);
 109                 if (result == 0) {
 110                         ilen = item_length_by_coord(&coord);
 111                         if (length <= ilen) {
 112                                 memcpy(item_body_by_coord(&coord), data,
 113                                        length);
 114                         } else {
 115                                 warning("nikita-3437",
 116                                         "Wrong black box length: %i < %i",
 117                                         ilen, length);
 118                                 result = RETERR(-EIO);
 119                         }
 120                         zrelse(coord.node);
 121                 }
 122         }
 123
 124         done_lh(&lh);
 125         return result;
 126
 127 }
 128
 129 int kill_black_box(reiser4_tree * tree, const reiser4_key * key)
 130 {
 131         return reiser4_cut_tree(tree, key, key, NULL, 1);
 132 }
 133
 134 /* Make Linus happy.
 135    Local variables:
 136    c-indentation-style: "K&R"
 137    mode-name: "LC"
 138    c-basic-offset: 8
 139    tab-width: 8
 140    fill-column: 120
 141    End:
 142 */