e2fsck/dx_dirinfo.c

   1 /*
   2  * dirinfo.c --- maintains the directory information table for e2fsck.
   3  *
   4  * Copyright (C) 1993 Theodore Ts'o.  This file may be redistributed
   5  * under the terms of the GNU Public License.
   6  */
   7
   8 #include "config.h"
   9 #include "e2fsck.h"
  10
  11 /*
  12  * This subroutine is called during pass1 to create a directory info
  13  * entry.  During pass1, the passed-in parent is 0; it will get filled
  14  * in during pass2.
  15  */
  16 void e2fsck_add_dx_dir(e2fsck_t ctx, ext2_ino_t ino, int num_blocks)
  17 {
  18         struct dx_dir_info *dir;
  19         int             i, j;
  20         errcode_t       retval;
  21         unsigned long   old_size;
  22
  23 #if 0
  24         printf("add_dx_dir_info for inode %lu...\n", ino);
  25 #endif
  26         if (!ctx->dx_dir_info) {
  27                 ctx->dx_dir_info_count = 0;
  28                 ctx->dx_dir_info_size = 100; /* Guess */
  29                 ctx->dx_dir_info  = (struct dx_dir_info *)
  30                         e2fsck_allocate_memory(ctx, ctx->dx_dir_info_size
  31                                                * sizeof (struct dx_dir_info),
  32                                                "directory map");
  33         }
  34
  35         if (ctx->dx_dir_info_count >= ctx->dx_dir_info_size) {
  36                 old_size = ctx->dx_dir_info_size * sizeof(struct dx_dir_info);
  37                 ctx->dx_dir_info_size += 10;
  38                 retval = ext2fs_resize_mem(old_size, ctx->dx_dir_info_size *
  39                                            sizeof(struct dx_dir_info),
  40                                            &ctx->dx_dir_info);
  41                 if (retval) {
  42                         fprintf(stderr, "Couldn't reallocate dx_dir_info "
  43                                 "structure to %d entries\n",
  44                                 ctx->dx_dir_info_size);
  45                         fatal_error(ctx, 0);
  46                         ctx->dx_dir_info_size -= 10;
  47                         return;
  48                 }
  49         }
  50
  51         /*
  52          * Normally, add_dx_dir_info is called with each inode in
  53          * sequential order; but once in a while (like when pass 3
  54          * needs to recreate the root directory or lost+found
  55          * directory) it is called out of order.  In those cases, we
  56          * need to move the dx_dir_info entries down to make room, since
  57          * the dx_dir_info array needs to be sorted by inode number for
  58          * get_dx_dir_info()'s sake.
  59          */
  60         if (ctx->dx_dir_info_count &&
  61             ctx->dx_dir_info[ctx->dx_dir_info_count-1].ino >= ino) {
  62                 for (i = ctx->dx_dir_info_count-1; i > 0; i--)
  63                         if (ctx->dx_dir_info[i-1].ino < ino)
  64                                 break;
  65                 dir = &ctx->dx_dir_info[i];
  66                 if (dir->ino != ino)
  67                         for (j = ctx->dx_dir_info_count++; j > i; j--)
  68                                 ctx->dx_dir_info[j] = ctx->dx_dir_info[j-1];
  69         } else
  70                 dir = &ctx->dx_dir_info[ctx->dx_dir_info_count++];
  71
  72         dir->ino = ino;
  73         dir->numblocks = num_blocks;
  74         dir->hashversion = 0;
  75         dir->dx_block = e2fsck_allocate_memory(ctx, num_blocks
  76                                        * sizeof (struct dx_dirblock_info),
  77                                        "dx_block info array");
  78
  79 }
  80
  81 /*
  82  * get_dx_dir_info() --- given an inode number, try to find the directory
  83  * information entry for it.
  84  */
  85 struct dx_dir_info *e2fsck_get_dx_dir_info(e2fsck_t ctx, ext2_ino_t ino)
  86 {
  87         int     low, high, mid;
  88
  89         low = 0;
  90         high = ctx->dx_dir_info_count-1;
  91         if (!ctx->dx_dir_info)
  92                 return 0;
  93         if (ino == ctx->dx_dir_info[low].ino)
  94                 return &ctx->dx_dir_info[low];
  95         if  (ino == ctx->dx_dir_info[high].ino)
  96                 return &ctx->dx_dir_info[high];
  97
  98         while (low < high) {
  99                 mid = (low+high)/2;
 100                 if (mid == low || mid == high)
 101                         break;
 102                 if (ino == ctx->dx_dir_info[mid].ino)
 103                         return &ctx->dx_dir_info[mid];
 104                 if (ino < ctx->dx_dir_info[mid].ino)
 105                         high = mid;
 106                 else
 107                         low = mid;
 108         }
 109         return 0;
 110 }
 111
 112 /*
 113  * Free the dx_dir_info structure when it isn't needed any more.
 114  */
 115 void e2fsck_free_dx_dir_info(e2fsck_t ctx)
 116 {
 117         int     i;
 118         struct dx_dir_info *dir;
 119
 120         if (ctx->dx_dir_info) {
 121                 dir = ctx->dx_dir_info;
 122                 for (i=0; i < ctx->dx_dir_info_count; i++,dir++) {
 123                         if (dir->dx_block) {
 124                                 ext2fs_free_mem(&dir->dx_block);
 125                                 dir->dx_block = 0;
 126                         }
 127                 }
 128                 ext2fs_free_mem(&ctx->dx_dir_info);
 129                 ctx->dx_dir_info = 0;
 130         }
 131         ctx->dx_dir_info_size = 0;
 132         ctx->dx_dir_info_count = 0;
 133 }
 134
 135 /*
 136  * Return the count of number of directories in the dx_dir_info structure
 137  */
 138 int e2fsck_get_num_dx_dirinfo(e2fsck_t ctx)
 139 {
 140         return ctx->dx_dir_info_count;
 141 }
 142
 143 /*
 144  * A simple interator function
 145  */
 146 struct dx_dir_info *e2fsck_dx_dir_info_iter(e2fsck_t ctx, int *control)
 147 {
 148         if (*control >= ctx->dx_dir_info_count)
 149                 return 0;
 150
 151         return(ctx->dx_dir_info + (*control)++);
 152 }