source: MondoRescue/branches/stable/mindi-busybox/e2fsprogs/ext2fs/irel_ma.c@ 821

/*
 * irel_ma.c
 *
 * Copyright (C) 1996, 1997 Theodore Ts'o.
 *
 * %Begin-Header%
 * This file may be redistributed under the terms of the GNU Public
 * License.
 * %End-Header%
 */

#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#if HAVE_ERRNO_H
#include <errno.h>
#endif

#include "ext2_fs.h"
#include "ext2fs.h"
#include "irel.h"

static errcode_t ima_put(ext2_irel irel, ext2_ino_t old,
             struct ext2_inode_relocate_entry *ent);
static errcode_t ima_get(ext2_irel irel, ext2_ino_t old,
             struct ext2_inode_relocate_entry *ent);
static errcode_t ima_get_by_orig(ext2_irel irel, ext2_ino_t orig, ext2_ino_t *old,
                 struct ext2_inode_relocate_entry *ent);
static errcode_t ima_start_iter(ext2_irel irel);
static errcode_t ima_next(ext2_irel irel, ext2_ino_t *old,
              struct ext2_inode_relocate_entry *ent);
static errcode_t ima_add_ref(ext2_irel irel, ext2_ino_t ino,
                 struct ext2_inode_reference *ref);
static errcode_t ima_start_iter_ref(ext2_irel irel, ext2_ino_t ino);
static errcode_t ima_next_ref(ext2_irel irel, struct ext2_inode_reference *ref);
static errcode_t ima_move(ext2_irel irel, ext2_ino_t old, ext2_ino_t new);
static errcode_t ima_delete(ext2_irel irel, ext2_ino_t old);
static errcode_t ima_free(ext2_irel irel);

/*
 * This data structure stores the array of inode references; there is
 * a structure for each inode.
 */
struct inode_reference_entry {
    __u16 num;
    struct ext2_inode_reference *refs;
};

struct irel_ma {
    __u32 magic;
    ext2_ino_t max_inode;
    ext2_ino_t ref_current;
    int   ref_iter;
    ext2_ino_t  *orig_map;
    struct ext2_inode_relocate_entry *entries;
    struct inode_reference_entry *ref_entries;
};

errcode_t ext2fs_irel_memarray_create(char *name, ext2_ino_t max_inode,
                      ext2_irel *new_irel)
{
    ext2_irel       irel = 0;
    errcode_t   retval;
    struct irel_ma  *ma = 0;
    size_t      size;

    *new_irel = 0;

    /*
     * Allocate memory structures
     */
    retval = ext2fs_get_mem(sizeof(struct ext2_inode_relocation_table),
                &irel);
    if (retval)
        goto errout;
    memset(irel, 0, sizeof(struct ext2_inode_relocation_table));

    retval = ext2fs_get_mem(strlen(name)+1, &irel->name);
    if (retval)
        goto errout;
    strcpy(irel->name, name);

    retval = ext2fs_get_mem(sizeof(struct irel_ma), &ma);
    if (retval)
        goto errout;
    memset(ma, 0, sizeof(struct irel_ma));
    irel->priv_data = ma;

    size = (size_t) (sizeof(ext2_ino_t) * (max_inode+1));
    retval = ext2fs_get_mem(size, &ma->orig_map);
    if (retval)
        goto errout;
    memset(ma->orig_map, 0, size);

    size = (size_t) (sizeof(struct ext2_inode_relocate_entry) *
             (max_inode+1));
    retval = ext2fs_get_mem(size, &ma->entries);
    if (retval)
        goto errout;
    memset(ma->entries, 0, size);

    size = (size_t) (sizeof(struct inode_reference_entry) *
             (max_inode+1));
    retval = ext2fs_get_mem(size, &ma->ref_entries);
    if (retval)
        goto errout;
    memset(ma->ref_entries, 0, size);
    ma->max_inode = max_inode;

    /*
     * Fill in the irel data structure
     */
    irel->put = ima_put;
    irel->get = ima_get;
    irel->get_by_orig = ima_get_by_orig;
    irel->start_iter = ima_start_iter;
    irel->next = ima_next;
    irel->add_ref = ima_add_ref;
    irel->start_iter_ref = ima_start_iter_ref;
    irel->next_ref = ima_next_ref;
    irel->move = ima_move;
    irel->delete = ima_delete;
    irel->free = ima_free;

    *new_irel = irel;
    return 0;

errout:
    ima_free(irel);
    return retval;
}

static errcode_t ima_put(ext2_irel irel, ext2_ino_t old,
            struct ext2_inode_relocate_entry *ent)
{
    struct inode_reference_entry    *ref_ent;
    struct irel_ma          *ma;
    errcode_t           retval;
    size_t              size, old_size;

    ma = irel->priv_data;
    if (old > ma->max_inode)
        return EXT2_ET_INVALID_ARGUMENT;

    /*
     * Force the orig field to the correct value; the application
     * program shouldn't be messing with this field.
     */
    if (ma->entries[(unsigned) old].new == 0)
        ent->orig = old;
    else
        ent->orig = ma->entries[(unsigned) old].orig;

    /*
     * If max_refs has changed, reallocate the refs array
     */
    ref_ent = ma->ref_entries + (unsigned) old;
    if (ref_ent->refs && ent->max_refs !=
        ma->entries[(unsigned) old].max_refs) {
        size = (sizeof(struct ext2_inode_reference) * ent->max_refs);
        old_size = (sizeof(struct ext2_inode_reference) *
                ma->entries[(unsigned) old].max_refs);
        retval = ext2fs_resize_mem(old_size, size, &ref_ent->refs);
        if (retval)
            return retval;
    }

    ma->entries[(unsigned) old] = *ent;
    ma->orig_map[(unsigned) ent->orig] = old;
    return 0;
}

static errcode_t ima_get(ext2_irel irel, ext2_ino_t old,
            struct ext2_inode_relocate_entry *ent)
{
    struct irel_ma  *ma;

    ma = irel->priv_data;
    if (old > ma->max_inode)
        return EXT2_ET_INVALID_ARGUMENT;
    if (ma->entries[(unsigned) old].new == 0)
        return ENOENT;
    *ent = ma->entries[(unsigned) old];
    return 0;
}

static errcode_t ima_get_by_orig(ext2_irel irel, ext2_ino_t orig, ext2_ino_t *old,
            struct ext2_inode_relocate_entry *ent)
{
    struct irel_ma  *ma;
    ext2_ino_t  ino;

    ma = irel->priv_data;
    if (orig > ma->max_inode)
        return EXT2_ET_INVALID_ARGUMENT;
    ino = ma->orig_map[(unsigned) orig];
    if (ino == 0)
        return ENOENT;
    *old = ino;
    *ent = ma->entries[(unsigned) ino];
    return 0;
}

static errcode_t ima_start_iter(ext2_irel irel)
{
    irel->current = 0;
    return 0;
}

static errcode_t ima_next(ext2_irel irel, ext2_ino_t *old,
             struct ext2_inode_relocate_entry *ent)
{
    struct irel_ma  *ma;

    ma = irel->priv_data;
    while (++irel->current < ma->max_inode) {
        if (ma->entries[(unsigned) irel->current].new == 0)
            continue;
        *old = irel->current;
        *ent = ma->entries[(unsigned) irel->current];
        return 0;
    }
    *old = 0;
    return 0;
}

static errcode_t ima_add_ref(ext2_irel irel, ext2_ino_t ino,
                 struct ext2_inode_reference *ref)
{
    struct irel_ma  *ma;
    size_t      size;
    struct inode_reference_entry *ref_ent;
    struct ext2_inode_relocate_entry *ent;
    errcode_t       retval;

    ma = irel->priv_data;
    if (ino > ma->max_inode)
        return EXT2_ET_INVALID_ARGUMENT;

    ref_ent = ma->ref_entries + (unsigned) ino;
    ent = ma->entries + (unsigned) ino;

    /*
     * If the inode reference array doesn't exist, create it.
     */
    if (ref_ent->refs == 0) {
        size = (size_t) ((sizeof(struct ext2_inode_reference) *
                  ent->max_refs));
        retval = ext2fs_get_mem(size, &ref_ent->refs);
        if (retval)
            return retval;
        memset(ref_ent->refs, 0, size);
        ref_ent->num = 0;
    }

    if (ref_ent->num >= ent->max_refs)
        return EXT2_ET_TOO_MANY_REFS;

    ref_ent->refs[(unsigned) ref_ent->num++] = *ref;
    return 0;
}

static errcode_t ima_start_iter_ref(ext2_irel irel, ext2_ino_t ino)
{
    struct irel_ma  *ma;

    ma = irel->priv_data;
    if (ino > ma->max_inode)
        return EXT2_ET_INVALID_ARGUMENT;
    if (ma->entries[(unsigned) ino].new == 0)
        return ENOENT;
    ma->ref_current = ino;
    ma->ref_iter = 0;
    return 0;
}

static errcode_t ima_next_ref(ext2_irel irel,
                  struct ext2_inode_reference *ref)
{
    struct irel_ma  *ma;
    struct inode_reference_entry *ref_ent;

    ma = irel->priv_data;

    ref_ent = ma->ref_entries + ma->ref_current;

    if ((ref_ent->refs == NULL) ||
        (ma->ref_iter >= ref_ent->num)) {
        ref->block = 0;
        ref->offset = 0;
        return 0;
    }
    *ref = ref_ent->refs[ma->ref_iter++];
    return 0;
}


static errcode_t ima_move(ext2_irel irel, ext2_ino_t old, ext2_ino_t new)
{
    struct irel_ma  *ma;

    ma = irel->priv_data;
    if ((old > ma->max_inode) || (new > ma->max_inode))
        return EXT2_ET_INVALID_ARGUMENT;
    if (ma->entries[(unsigned) old].new == 0)
        return ENOENT;

    ma->entries[(unsigned) new] = ma->entries[(unsigned) old];
    ext2fs_free_mem(&ma->ref_entries[(unsigned) new].refs);
    ma->ref_entries[(unsigned) new] = ma->ref_entries[(unsigned) old];

    ma->entries[(unsigned) old].new = 0;
    ma->ref_entries[(unsigned) old].num = 0;
    ma->ref_entries[(unsigned) old].refs = 0;

    ma->orig_map[ma->entries[new].orig] = new;
    return 0;
}

static errcode_t ima_delete(ext2_irel irel, ext2_ino_t old)
{
    struct irel_ma  *ma;

    ma = irel->priv_data;
    if (old > ma->max_inode)
        return EXT2_ET_INVALID_ARGUMENT;
    if (ma->entries[(unsigned) old].new == 0)
        return ENOENT;

    ma->entries[old].new = 0;
    ext2fs_free_mem(&ma->ref_entries[(unsigned) old].refs);
    ma->orig_map[ma->entries[(unsigned) old].orig] = 0;

    ma->ref_entries[(unsigned) old].num = 0;
    ma->ref_entries[(unsigned) old].refs = 0;
    return 0;
}

static errcode_t ima_free(ext2_irel irel)
{
    struct irel_ma  *ma;
    ext2_ino_t  ino;

    if (!irel)
        return 0;

    ma = irel->priv_data;

    if (ma) {
        ext2fs_free_mem(&ma->orig_map);
        ext2fs_free_mem(&ma->entries);
        if (ma->ref_entries) {
            for (ino = 0; ino <= ma->max_inode; ino++) {
                ext2fs_free_mem(&ma->ref_entries[(unsigned) ino].refs);
            }
            ext2fs_free_mem(&ma->ref_entries);
        }
        ext2fs_free_mem(&ma);
    }
    ext2fs_free_mem(&irel->name);
    ext2fs_free_mem(&irel);
    return 0;
}