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      1 /*
      2  * irel_ma.c
      3  *
      4  * Copyright (C) 1996, 1997 Theodore Ts'o.
      5  *
      6  * %Begin-Header%
      7  * This file may be redistributed under the terms of the GNU Public
      8  * License.
      9  * %End-Header%
     10  */
     11 
     12 #include <fcntl.h>
     13 #include <stdio.h>
     14 #include <string.h>
     15 #if HAVE_UNISTD_H
     16 #include <unistd.h>
     17 #endif
     18 #if HAVE_ERRNO_H
     19 #include <errno.h>
     20 #endif
     21 
     22 #include "ext2_fs.h"
     23 #include "ext2fs.h"
     24 #include "irel.h"
     25 
     26 static errcode_t ima_put(ext2_irel irel, ext2_ino_t old,
     27 			 struct ext2_inode_relocate_entry *ent);
     28 static errcode_t ima_get(ext2_irel irel, ext2_ino_t old,
     29 			 struct ext2_inode_relocate_entry *ent);
     30 static errcode_t ima_get_by_orig(ext2_irel irel, ext2_ino_t orig, ext2_ino_t *old,
     31 				 struct ext2_inode_relocate_entry *ent);
     32 static errcode_t ima_start_iter(ext2_irel irel);
     33 static errcode_t ima_next(ext2_irel irel, ext2_ino_t *old,
     34 			  struct ext2_inode_relocate_entry *ent);
     35 static errcode_t ima_add_ref(ext2_irel irel, ext2_ino_t ino,
     36 			     struct ext2_inode_reference *ref);
     37 static errcode_t ima_start_iter_ref(ext2_irel irel, ext2_ino_t ino);
     38 static errcode_t ima_next_ref(ext2_irel irel, struct ext2_inode_reference *ref);
     39 static errcode_t ima_move(ext2_irel irel, ext2_ino_t old, ext2_ino_t new);
     40 static errcode_t ima_delete(ext2_irel irel, ext2_ino_t old);
     41 static errcode_t ima_free(ext2_irel irel);
     42 
     43 /*
     44  * This data structure stores the array of inode references; there is
     45  * a structure for each inode.
     46  */
     47 struct inode_reference_entry {
     48 	__u16 num;
     49 	struct ext2_inode_reference *refs;
     50 };
     51 
     52 struct irel_ma {
     53 	__u32 magic;
     54 	ext2_ino_t max_inode;
     55 	ext2_ino_t ref_current;
     56 	int   ref_iter;
     57 	ext2_ino_t	*orig_map;
     58 	struct ext2_inode_relocate_entry *entries;
     59 	struct inode_reference_entry *ref_entries;
     60 };
     61 
     62 errcode_t ext2fs_irel_memarray_create(char *name, ext2_ino_t max_inode,
     63 				      ext2_irel *new_irel)
     64 {
     65 	ext2_irel		irel = 0;
     66 	errcode_t	retval;
     67 	struct irel_ma 	*ma = 0;
     68 	size_t		size;
     69 
     70 	*new_irel = 0;
     71 
     72 	/*
     73 	 * Allocate memory structures
     74 	 */
     75 	retval = ext2fs_get_mem(sizeof(struct ext2_inode_relocation_table),
     76 				&irel);
     77 	if (retval)
     78 		goto errout;
     79 	memset(irel, 0, sizeof(struct ext2_inode_relocation_table));
     80 
     81 	retval = ext2fs_get_mem(strlen(name)+1, &irel->name);
     82 	if (retval)
     83 		goto errout;
     84 	strcpy(irel->name, name);
     85 
     86 	retval = ext2fs_get_mem(sizeof(struct irel_ma), &ma);
     87 	if (retval)
     88 		goto errout;
     89 	memset(ma, 0, sizeof(struct irel_ma));
     90 	irel->priv_data = ma;
     91 
     92 	size = (size_t) (sizeof(ext2_ino_t) * (max_inode+1));
     93 	retval = ext2fs_get_array(max_inode+1, sizeof(ext2_ino_t),
     94 		&ma->orig_map);
     95 	if (retval)
     96 		goto errout;
     97 	memset(ma->orig_map, 0, size);
     98 
     99 	size = (size_t) (sizeof(struct ext2_inode_relocate_entry) *
    100 			 (max_inode+1));
    101 	retval = ext2fs_get_array((max_inode+1,
    102 		sizeof(struct ext2_inode_relocate_entry), &ma->entries);
    103 	if (retval)
    104 		goto errout;
    105 	memset(ma->entries, 0, size);
    106 
    107 	size = (size_t) (sizeof(struct inode_reference_entry) *
    108 			 (max_inode+1));
    109 	retval = ext2fs_get_mem(max_inode+1,
    110 		sizeof(struct inode_reference_entry), &ma->ref_entries);
    111 	if (retval)
    112 		goto errout;
    113 	memset(ma->ref_entries, 0, size);
    114 	ma->max_inode = max_inode;
    115 
    116 	/*
    117 	 * Fill in the irel data structure
    118 	 */
    119 	irel->put = ima_put;
    120 	irel->get = ima_get;
    121 	irel->get_by_orig = ima_get_by_orig;
    122 	irel->start_iter = ima_start_iter;
    123 	irel->next = ima_next;
    124 	irel->add_ref = ima_add_ref;
    125 	irel->start_iter_ref = ima_start_iter_ref;
    126 	irel->next_ref = ima_next_ref;
    127 	irel->move = ima_move;
    128 	irel->delete = ima_delete;
    129 	irel->free = ima_free;
    130 
    131 	*new_irel = irel;
    132 	return 0;
    133 
    134 errout:
    135 	ima_free(irel);
    136 	return retval;
    137 }
    138 
    139 static errcode_t ima_put(ext2_irel irel, ext2_ino_t old,
    140 			struct ext2_inode_relocate_entry *ent)
    141 {
    142 	struct inode_reference_entry	*ref_ent;
    143 	struct irel_ma 			*ma;
    144 	errcode_t			retval;
    145 	size_t				size, old_size;
    146 
    147 	ma = irel->priv_data;
    148 	if (old > ma->max_inode)
    149 		return EXT2_ET_INVALID_ARGUMENT;
    150 
    151 	/*
    152 	 * Force the orig field to the correct value; the application
    153 	 * program shouldn't be messing with this field.
    154 	 */
    155 	if (ma->entries[(unsigned) old].new == 0)
    156 		ent->orig = old;
    157 	else
    158 		ent->orig = ma->entries[(unsigned) old].orig;
    159 
    160 	/*
    161 	 * If max_refs has changed, reallocate the refs array
    162 	 */
    163 	ref_ent = ma->ref_entries + (unsigned) old;
    164 	if (ref_ent->refs && ent->max_refs !=
    165 	    ma->entries[(unsigned) old].max_refs) {
    166 		size = (sizeof(struct ext2_inode_reference) * ent->max_refs);
    167 		old_size = (sizeof(struct ext2_inode_reference) *
    168 			    ma->entries[(unsigned) old].max_refs);
    169 		retval = ext2fs_resize_mem(old_size, size, &ref_ent->refs);
    170 		if (retval)
    171 			return retval;
    172 	}
    173 
    174 	ma->entries[(unsigned) old] = *ent;
    175 	ma->orig_map[(unsigned) ent->orig] = old;
    176 	return 0;
    177 }
    178 
    179 static errcode_t ima_get(ext2_irel irel, ext2_ino_t old,
    180 			struct ext2_inode_relocate_entry *ent)
    181 {
    182 	struct irel_ma 	*ma;
    183 
    184 	ma = irel->priv_data;
    185 	if (old > ma->max_inode)
    186 		return EXT2_ET_INVALID_ARGUMENT;
    187 	if (ma->entries[(unsigned) old].new == 0)
    188 		return ENOENT;
    189 	*ent = ma->entries[(unsigned) old];
    190 	return 0;
    191 }
    192 
    193 static errcode_t ima_get_by_orig(ext2_irel irel, ext2_ino_t orig, ext2_ino_t *old,
    194 			struct ext2_inode_relocate_entry *ent)
    195 {
    196 	struct irel_ma 	*ma;
    197 	ext2_ino_t	ino;
    198 
    199 	ma = irel->priv_data;
    200 	if (orig > ma->max_inode)
    201 		return EXT2_ET_INVALID_ARGUMENT;
    202 	ino = ma->orig_map[(unsigned) orig];
    203 	if (ino == 0)
    204 		return ENOENT;
    205 	*old = ino;
    206 	*ent = ma->entries[(unsigned) ino];
    207 	return 0;
    208 }
    209 
    210 static errcode_t ima_start_iter(ext2_irel irel)
    211 {
    212 	irel->current = 0;
    213 	return 0;
    214 }
    215 
    216 static errcode_t ima_next(ext2_irel irel, ext2_ino_t *old,
    217 			 struct ext2_inode_relocate_entry *ent)
    218 {
    219 	struct irel_ma 	*ma;
    220 
    221 	ma = irel->priv_data;
    222 	while (++irel->current < ma->max_inode) {
    223 		if (ma->entries[(unsigned) irel->current].new == 0)
    224 			continue;
    225 		*old = irel->current;
    226 		*ent = ma->entries[(unsigned) irel->current];
    227 		return 0;
    228 	}
    229 	*old = 0;
    230 	return 0;
    231 }
    232 
    233 static errcode_t ima_add_ref(ext2_irel irel, ext2_ino_t ino,
    234 			     struct ext2_inode_reference *ref)
    235 {
    236 	struct irel_ma 	*ma;
    237 	size_t		size;
    238 	struct inode_reference_entry *ref_ent;
    239 	struct ext2_inode_relocate_entry *ent;
    240 	errcode_t		retval;
    241 
    242 	ma = irel->priv_data;
    243 	if (ino > ma->max_inode)
    244 		return EXT2_ET_INVALID_ARGUMENT;
    245 
    246 	ref_ent = ma->ref_entries + (unsigned) ino;
    247 	ent = ma->entries + (unsigned) ino;
    248 
    249 	/*
    250 	 * If the inode reference array doesn't exist, create it.
    251 	 */
    252 	if (ref_ent->refs == 0) {
    253 		size = (size_t) ((sizeof(struct ext2_inode_reference) *
    254 				  ent->max_refs));
    255 		retval = ext2fs_get_array(ent->max_refs,
    256 			sizeof(struct ext2_inode_reference), &ref_ent->refs);
    257 		if (retval)
    258 			return retval;
    259 		memset(ref_ent->refs, 0, size);
    260 		ref_ent->num = 0;
    261 	}
    262 
    263 	if (ref_ent->num >= ent->max_refs)
    264 		return EXT2_ET_TOO_MANY_REFS;
    265 
    266 	ref_ent->refs[(unsigned) ref_ent->num++] = *ref;
    267 	return 0;
    268 }
    269 
    270 static errcode_t ima_start_iter_ref(ext2_irel irel, ext2_ino_t ino)
    271 {
    272 	struct irel_ma 	*ma;
    273 
    274 	ma = irel->priv_data;
    275 	if (ino > ma->max_inode)
    276 		return EXT2_ET_INVALID_ARGUMENT;
    277 	if (ma->entries[(unsigned) ino].new == 0)
    278 		return ENOENT;
    279 	ma->ref_current = ino;
    280 	ma->ref_iter = 0;
    281 	return 0;
    282 }
    283 
    284 static errcode_t ima_next_ref(ext2_irel irel,
    285 			      struct ext2_inode_reference *ref)
    286 {
    287 	struct irel_ma 	*ma;
    288 	struct inode_reference_entry *ref_ent;
    289 
    290 	ma = irel->priv_data;
    291 
    292 	ref_ent = ma->ref_entries + ma->ref_current;
    293 
    294 	if ((ref_ent->refs == NULL) ||
    295 	    (ma->ref_iter >= ref_ent->num)) {
    296 		ref->block = 0;
    297 		ref->offset = 0;
    298 		return 0;
    299 	}
    300 	*ref = ref_ent->refs[ma->ref_iter++];
    301 	return 0;
    302 }
    303 
    304 
    305 static errcode_t ima_move(ext2_irel irel, ext2_ino_t old, ext2_ino_t new)
    306 {
    307 	struct irel_ma 	*ma;
    308 
    309 	ma = irel->priv_data;
    310 	if ((old > ma->max_inode) || (new > ma->max_inode))
    311 		return EXT2_ET_INVALID_ARGUMENT;
    312 	if (ma->entries[(unsigned) old].new == 0)
    313 		return ENOENT;
    314 
    315 	ma->entries[(unsigned) new] = ma->entries[(unsigned) old];
    316 	if (ma->ref_entries[(unsigned) new].refs)
    317 		ext2fs_free_mem(&ma->ref_entries[(unsigned) new].refs);
    318 	ma->ref_entries[(unsigned) new] = ma->ref_entries[(unsigned) old];
    319 
    320 	ma->entries[(unsigned) old].new = 0;
    321 	ma->ref_entries[(unsigned) old].num = 0;
    322 	ma->ref_entries[(unsigned) old].refs = 0;
    323 
    324 	ma->orig_map[ma->entries[new].orig] = new;
    325 	return 0;
    326 }
    327 
    328 static errcode_t ima_delete(ext2_irel irel, ext2_ino_t old)
    329 {
    330 	struct irel_ma 	*ma;
    331 
    332 	ma = irel->priv_data;
    333 	if (old > ma->max_inode)
    334 		return EXT2_ET_INVALID_ARGUMENT;
    335 	if (ma->entries[(unsigned) old].new == 0)
    336 		return ENOENT;
    337 
    338 	ma->entries[old].new = 0;
    339 	if (ma->ref_entries[(unsigned) old].refs)
    340 		ext2fs_free_mem(&ma->ref_entries[(unsigned) old].refs);
    341 	ma->orig_map[ma->entries[(unsigned) old].orig] = 0;
    342 
    343 	ma->ref_entries[(unsigned) old].num = 0;
    344 	ma->ref_entries[(unsigned) old].refs = 0;
    345 	return 0;
    346 }
    347 
    348 static errcode_t ima_free(ext2_irel irel)
    349 {
    350 	struct irel_ma 	*ma;
    351 	ext2_ino_t	ino;
    352 
    353 	if (!irel)
    354 		return 0;
    355 
    356 	ma = irel->priv_data;
    357 
    358 	if (ma) {
    359 		if (ma->orig_map)
    360 			ext2fs_free_mem(&ma->orig_map);
    361 		if (ma->entries)
    362 			ext2fs_free_mem(&ma->entries);
    363 		if (ma->ref_entries) {
    364 			for (ino = 0; ino <= ma->max_inode; ino++) {
    365 				if (ma->ref_entries[(unsigned) ino].refs)
    366 					ext2fs_free_mem(&ma->ref_entries[(unsigned) ino].refs);
    367 			}
    368 			ext2fs_free_mem(&ma->ref_entries);
    369 		}
    370 		ext2fs_free_mem(&ma);
    371 	}
    372 	if (irel->name)
    373 		ext2fs_free_mem(&irel->name);
    374 	ext2fs_free_mem(&irel);
    375 	return 0;
    376 }
    377