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      1 /*
      2  * brel_ma.c
      3  *
      4  * Copyright (C) 1996, 1997 Theodore Ts'o.
      5  *
      6  * TODO: rewrite to not use a direct array!!!  (Fortunately this
      7  * module isn't really used yet.)
      8  *
      9  * %Begin-Header%
     10  * This file may be redistributed under the terms of the GNU Public
     11  * License.
     12  * %End-Header%
     13  */
     14 
     15 #include <fcntl.h>
     16 #include <stdio.h>
     17 #include <string.h>
     18 #if HAVE_UNISTD_H
     19 #include <unistd.h>
     20 #endif
     21 #if HAVE_ERRNO_H
     22 #include <errno.h>
     23 #endif
     24 
     25 #include "ext2_fs.h"
     26 #include "ext2fs.h"
     27 #include "brel.h"
     28 
     29 static errcode_t bma_put(ext2_brel brel, blk_t old,
     30 			struct ext2_block_relocate_entry *ent);
     31 static errcode_t bma_get(ext2_brel brel, blk_t old,
     32 			struct ext2_block_relocate_entry *ent);
     33 static errcode_t bma_start_iter(ext2_brel brel);
     34 static errcode_t bma_next(ext2_brel brel, blk_t *old,
     35 			 struct ext2_block_relocate_entry *ent);
     36 static errcode_t bma_move(ext2_brel brel, blk_t old, blk_t new);
     37 static errcode_t bma_delete(ext2_brel brel, blk_t old);
     38 static errcode_t bma_free(ext2_brel brel);
     39 
     40 struct brel_ma {
     41 	__u32 magic;
     42 	blk_t max_block;
     43 	struct ext2_block_relocate_entry *entries;
     44 };
     45 
     46 errcode_t ext2fs_brel_memarray_create(char *name, blk_t max_block,
     47 				      ext2_brel *new_brel)
     48 {
     49 	ext2_brel		brel = 0;
     50 	errcode_t	retval;
     51 	struct brel_ma 	*ma = 0;
     52 	size_t		size;
     53 
     54 	*new_brel = 0;
     55 
     56 	/*
     57 	 * Allocate memory structures
     58 	 */
     59 	retval = ext2fs_get_mem(sizeof(struct ext2_block_relocation_table),
     60 				&brel);
     61 	if (retval)
     62 		goto errout;
     63 	memset(brel, 0, sizeof(struct ext2_block_relocation_table));
     64 
     65 	retval = ext2fs_get_mem(strlen(name)+1, &brel->name);
     66 	if (retval)
     67 		goto errout;
     68 	strcpy(brel->name, name);
     69 
     70 	retval = ext2fs_get_mem(sizeof(struct brel_ma), &ma);
     71 	if (retval)
     72 		goto errout;
     73 	memset(ma, 0, sizeof(struct brel_ma));
     74 	brel->priv_data = ma;
     75 
     76 	size = (size_t) (sizeof(struct ext2_block_relocate_entry) *
     77 			 (max_block+1));
     78 	retval = ext2fs_get_array(max_block+1,
     79 		sizeof(struct ext2_block_relocate_entry), &ma->entries);
     80 	if (retval)
     81 		goto errout;
     82 	memset(ma->entries, 0, size);
     83 	ma->max_block = max_block;
     84 
     85 	/*
     86 	 * Fill in the brel data structure
     87 	 */
     88 	brel->put = bma_put;
     89 	brel->get = bma_get;
     90 	brel->start_iter = bma_start_iter;
     91 	brel->next = bma_next;
     92 	brel->move = bma_move;
     93 	brel->delete = bma_delete;
     94 	brel->free = bma_free;
     95 
     96 	*new_brel = brel;
     97 	return 0;
     98 
     99 errout:
    100 	bma_free(brel);
    101 	return retval;
    102 }
    103 
    104 static errcode_t bma_put(ext2_brel brel, blk_t old,
    105 			struct ext2_block_relocate_entry *ent)
    106 {
    107 	struct brel_ma 	*ma;
    108 
    109 	ma = brel->priv_data;
    110 	if (old > ma->max_block)
    111 		return EXT2_ET_INVALID_ARGUMENT;
    112 	ma->entries[(unsigned)old] = *ent;
    113 	return 0;
    114 }
    115 
    116 static errcode_t bma_get(ext2_brel brel, blk_t old,
    117 			struct ext2_block_relocate_entry *ent)
    118 {
    119 	struct brel_ma 	*ma;
    120 
    121 	ma = brel->priv_data;
    122 	if (old > ma->max_block)
    123 		return EXT2_ET_INVALID_ARGUMENT;
    124 	if (ma->entries[(unsigned)old].new == 0)
    125 		return ENOENT;
    126 	*ent = ma->entries[old];
    127 	return 0;
    128 }
    129 
    130 static errcode_t bma_start_iter(ext2_brel brel)
    131 {
    132 	brel->current = 0;
    133 	return 0;
    134 }
    135 
    136 static errcode_t bma_next(ext2_brel brel, blk_t *old,
    137 			  struct ext2_block_relocate_entry *ent)
    138 {
    139 	struct brel_ma 	*ma;
    140 
    141 	ma = brel->priv_data;
    142 	while (++brel->current < ma->max_block) {
    143 		if (ma->entries[(unsigned)brel->current].new == 0)
    144 			continue;
    145 		*old = brel->current;
    146 		*ent = ma->entries[(unsigned)brel->current];
    147 		return 0;
    148 	}
    149 	*old = 0;
    150 	return 0;
    151 }
    152 
    153 static errcode_t bma_move(ext2_brel brel, blk_t old, blk_t new)
    154 {
    155 	struct brel_ma 	*ma;
    156 
    157 	ma = brel->priv_data;
    158 	if ((old > ma->max_block) || (new > ma->max_block))
    159 		return EXT2_ET_INVALID_ARGUMENT;
    160 	if (ma->entries[(unsigned)old].new == 0)
    161 		return ENOENT;
    162 	ma->entries[(unsigned)new] = ma->entries[old];
    163 	ma->entries[(unsigned)old].new = 0;
    164 	return 0;
    165 }
    166 
    167 static errcode_t bma_delete(ext2_brel brel, blk_t old)
    168 {
    169 	struct brel_ma 	*ma;
    170 
    171 	ma = brel->priv_data;
    172 	if (old > ma->max_block)
    173 		return EXT2_ET_INVALID_ARGUMENT;
    174 	if (ma->entries[(unsigned)old].new == 0)
    175 		return ENOENT;
    176 	ma->entries[(unsigned)old].new = 0;
    177 	return 0;
    178 }
    179 
    180 static errcode_t bma_free(ext2_brel brel)
    181 {
    182 	struct brel_ma 	*ma;
    183 
    184 	if (!brel)
    185 		return 0;
    186 
    187 	ma = brel->priv_data;
    188 
    189 	if (ma) {
    190 		if (ma->entries)
    191 			ext2fs_free_mem(&ma->entries);
    192 		ext2fs_free_mem(&ma);
    193 	}
    194 	if (brel->name)
    195 		ext2fs_free_mem(&brel->name);
    196 	ext2fs_free_mem(&brel);
    197 	return 0;
    198 }
    199