source: mainline/uspace/srv/fs/exfat/exfat_directory.c

/*
 * Copyright (c) 2011 Oleg Romanenko
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup exfat
 * @{
 */

/**
 * @file        exfat_directory.c
 * @brief       Functions that work with FAT directory.
 */

#include "exfat.h"
#include "exfat_directory.h"
#include "exfat_fat.h"
#include <block.h>
#include <errno.h>
#include <byteorder.h>
#include <mem.h>
#include <stdlib.h>
#include <str.h>
#include <align.h>

void exfat_directory_init(exfat_directory_t *di)
{
        di->b = NULL;
        di->nodep = NULL;
        di->bs = NULL;
        di->blocks = 0;
        di->pos = 0;
        di->bnum = 0;
        di->last = false;
        di->fragmented = false;
        di->firstc = 0;
}

errno_t exfat_directory_open(exfat_node_t *nodep, exfat_directory_t *di)
{
        exfat_directory_init(di);
        di->nodep = nodep;
        if (di->nodep->type != EXFAT_DIRECTORY)
                return EINVAL;
        di->service_id = nodep->idx->service_id;
        di->fragmented = nodep->fragmented;
        di->firstc = nodep->firstc;

        di->bs = block_bb_get(di->service_id);
        di->blocks = ROUND_UP(nodep->size, BPS(di->bs)) / BPS(di->bs);
        return EOK;
}

errno_t exfat_directory_open_parent(exfat_directory_t *di,
    service_id_t service_id, exfat_cluster_t firstc, bool fragmented)
{
        exfat_directory_init(di);
        di->service_id = service_id;
        di->fragmented = fragmented;
        di->firstc = firstc;
        di->bs = block_bb_get(service_id);
        di->blocks = 0;
        return EOK;
}

errno_t exfat_directory_close(exfat_directory_t *di)
{
        errno_t rc = EOK;

        if (di->b) {
                rc = block_put(di->b);
                di->b = NULL;
        }

        return rc;
}

static errno_t exfat_directory_block_load(exfat_directory_t *di)
{
        uint32_t i;
        errno_t rc = EOK;

        i = (di->pos * sizeof(exfat_dentry_t)) / BPS(di->bs);
        if (di->nodep && (i >= di->blocks))
                return ENOENT;

        if (di->b && di->bnum != i) {
                rc = block_put(di->b);
                di->b = NULL;
                if (rc != EOK)
                        return rc;
        }
        if (!di->b) {
                if (di->nodep) {
                        rc = exfat_block_get(&di->b, di->bs, di->nodep, i,
                            BLOCK_FLAGS_NONE);
                } else {
                        rc = exfat_block_get_by_clst(&di->b, di->bs,
                            di->service_id, di->fragmented, di->firstc, NULL, i,
                            BLOCK_FLAGS_NONE);
                }
                if (rc != EOK) {
                        di->b = NULL;
                        return rc;
                }
                di->bnum = i;
        }
        return rc;
}

errno_t exfat_directory_next(exfat_directory_t *di)
{
        errno_t rc;

        di->pos += 1;
        rc = exfat_directory_block_load(di);
        if (rc != EOK)
                di->pos -= 1;

        return rc;
}

errno_t exfat_directory_prev(exfat_directory_t *di)
{
        errno_t rc = EOK;

        if (di->pos > 0) {
                di->pos -= 1;
                rc = exfat_directory_block_load(di);
        } else
                return ENOENT;

        if (rc != EOK)
                di->pos += 1;

        return rc;
}

errno_t exfat_directory_seek(exfat_directory_t *di, aoff64_t pos)
{
        aoff64_t _pos = di->pos;
        errno_t rc;

        di->pos = pos;
        rc = exfat_directory_block_load(di);
        if (rc != EOK)
                di->pos = _pos;

        return rc;
}

errno_t exfat_directory_get(exfat_directory_t *di, exfat_dentry_t **d)
{
        errno_t rc;

        rc = exfat_directory_block_load(di);
        if (rc == EOK) {
                aoff64_t o = di->pos % (BPS(di->bs) / sizeof(exfat_dentry_t));
                *d = ((exfat_dentry_t *)di->b->data) + o;
        }

        return rc;
}

errno_t exfat_directory_find(exfat_directory_t *di, exfat_dentry_clsf_t type,
    exfat_dentry_t **d)
{
        do {
                if (exfat_directory_get(di, d) == EOK) {
                        if (exfat_classify_dentry(*d) == type)
                                return EOK;
                } else
                        return ENOENT;
        } while (exfat_directory_next(di) == EOK);

        return ENOENT;
}

errno_t
exfat_directory_find_continue(exfat_directory_t *di, exfat_dentry_clsf_t type,
    exfat_dentry_t **d)
{
        errno_t rc;
        rc = exfat_directory_next(di);
        if (rc != EOK)
                return rc;
        return exfat_directory_find(di, type, d);
}

errno_t exfat_directory_read_file(exfat_directory_t *di, char *name, size_t size,
    exfat_file_dentry_t *df, exfat_stream_dentry_t *ds)
{
        uint16_t wname[EXFAT_FILENAME_LEN + 1];
        exfat_dentry_t *d = NULL;
        errno_t rc;
        int i;
        size_t offset = 0;
        aoff64_t start_pos = 0;

        rc = exfat_directory_find(di, EXFAT_DENTRY_FILE, &d);
        if (rc != EOK)
                return rc;
        start_pos = di->pos;
        *df = d->file;

        rc = exfat_directory_next(di);
        if (rc != EOK)
                return rc;
        rc = exfat_directory_get(di, &d);
        if (rc != EOK)
                return rc;
        if (exfat_classify_dentry(d) != EXFAT_DENTRY_STREAM)
                return ENOENT;
        *ds  = d->stream;

        if (ds->name_size > size)
                return EOVERFLOW;

        for (i = 0; i < df->count - 1; i++) {
                rc = exfat_directory_next(di);
                if (rc != EOK)
                        return rc;
                rc = exfat_directory_get(di, &d);
                if (rc != EOK)
                        return rc;
                if (exfat_classify_dentry(d) != EXFAT_DENTRY_NAME)
                        return ENOENT;
                exfat_dentry_get_name(&d->name, ds->name_size, wname, &offset);
        }
        rc = utf16_to_str(name, size, wname);
        if (rc != EOK)
                return rc;

        exfat_directory_seek(di, start_pos);
        return EOK;
}

errno_t exfat_directory_read_vollabel(exfat_directory_t *di, char *label,
    size_t size)
{
        uint16_t wlabel[EXFAT_VOLLABEL_LEN + 1];
        exfat_dentry_t *d = NULL;
        errno_t rc;
        aoff64_t start_pos = 0;

        start_pos = di->pos;

        rc = exfat_directory_seek(di, 0);
        if (rc != EOK)
                return rc;

        rc = exfat_directory_find(di, EXFAT_DENTRY_VOLLABEL, &d);
        if (rc != EOK)
                return rc;

        exfat_dentry_get_vollabel(&d->vollabel, EXFAT_VOLLABEL_LEN, wlabel);

        rc = utf16_to_str(label, size, wlabel);
        if (rc != EOK)
                return rc;

        exfat_directory_seek(di, start_pos);
        return EOK;
}

static uint16_t exfat_directory_set_checksum(const uint8_t *bytes, size_t count)
{
        uint16_t checksum = 0;
        size_t idx;

        for (idx = 0; idx < count; idx++) {
                if (idx == 2 || idx == 3)
                        continue;
                checksum = ((checksum << 15) | (checksum >> 1)) +
                    (uint16_t)bytes[idx];
        }
        return checksum;
}

errno_t exfat_directory_sync_file(exfat_directory_t *di, exfat_file_dentry_t *df,
    exfat_stream_dentry_t *ds)
{
        errno_t rc;
        int i, count;
        exfat_dentry_t *array = NULL, *de;
        aoff64_t pos = di->pos;

        rc = exfat_directory_get(di, &de);
        if (rc != EOK)
                return rc;
        count = de->file.count + 1;
        array = (exfat_dentry_t *) malloc(count * sizeof(exfat_dentry_t));
        if (!array)
                return ENOMEM;
        for (i = 0; i < count; i++) {
                rc = exfat_directory_get(di, &de);
                if (rc != EOK) {
                        free(array);
                        return rc;
                }
                array[i] = *de;
                rc = exfat_directory_next(di);
                if (rc != EOK) {
                        free(array);
                        return rc;
                }
        }
        rc = exfat_directory_seek(di, pos);
        if (rc != EOK) {
                free(array);
                return rc;
        }

        /* Sync */
        array[0].file.attr = host2uint16_t_le(df->attr);
        array[1].stream.firstc = host2uint32_t_le(ds->firstc);
        array[1].stream.flags = ds->flags;
        array[1].stream.valid_data_size = host2uint64_t_le(ds->valid_data_size);
        array[1].stream.data_size = host2uint64_t_le(ds->data_size);
        array[0].file.checksum =
            host2uint16_t_le(exfat_directory_set_checksum((uint8_t *)array,
            count * sizeof(exfat_dentry_t)));

        /* Store */
        for (i = 0; i < count; i++) {
                rc = exfat_directory_get(di, &de);
                if (rc != EOK) {
                        free(array);
                        return rc;
                }
                *de = array[i];
                di->b->dirty = true;
                rc = exfat_directory_next(di);
                if (rc != EOK) {
                        free(array);
                        return rc;
                }
        }
        free(array);

        return EOK;
}

errno_t exfat_directory_write_file(exfat_directory_t *di, const char *name)
{
        fs_node_t *fn;
        exfat_node_t *uctablep;
        uint16_t *uctable;
        exfat_dentry_t df, ds, *de;
        uint16_t wname[EXFAT_FILENAME_LEN + 1];
        errno_t rc;
        int i;
        size_t uctable_chars, j;
        aoff64_t pos;

        rc = str_to_utf16(wname, EXFAT_FILENAME_LEN, name);
        if (rc != EOK)
                return rc;
        rc = exfat_uctable_get(&fn, di->service_id);
        if (rc != EOK)
                return rc;
        uctablep = EXFAT_NODE(fn);

        uctable_chars = ALIGN_DOWN(uctablep->size,
            sizeof(uint16_t)) / sizeof(uint16_t);
        uctable = (uint16_t *) malloc(uctable_chars * sizeof(uint16_t));
        rc = exfat_read_uctable(di->bs, uctablep, (uint8_t *)uctable);
        if (rc != EOK) {
                (void) exfat_node_put(fn);
                free(uctable);
                return rc;
        }

        /* Fill stream entry */
        ds.type = EXFAT_TYPE_STREAM;
        ds.stream.flags = 0;
        ds.stream.valid_data_size = 0;
        ds.stream.data_size = 0;
        ds.stream.name_size = utf16_wsize(wname);
        ds.stream.hash = host2uint16_t_le(exfat_name_hash(wname, uctable,
            uctable_chars));

        /* Fill file entry */
        df.type = EXFAT_TYPE_FILE;
        df.file.attr = 0;
        df.file.count = ROUND_UP(ds.stream.name_size, EXFAT_NAME_PART_LEN) /
            EXFAT_NAME_PART_LEN + 1;
        df.file.checksum = 0;

        free(uctable);
        rc = exfat_node_put(fn);
        if (rc != EOK)
                return rc;

        /* Looking for set of free entries */
        rc = exfat_directory_lookup_free(di, df.file.count + 1);
        if (rc != EOK)
                return rc;
        pos = di->pos;

        /* Write file entry */
        rc = exfat_directory_get(di, &de);
        if (rc != EOK)
                return rc;
        *de = df;
        di->b->dirty = true;
        rc = exfat_directory_next(di);
        if (rc != EOK)
                return rc;

        /* Write stream entry */
        rc = exfat_directory_get(di, &de);
        if (rc != EOK)
                return rc;
        *de = ds;
        di->b->dirty = true;

        /* Write file name */
        size_t chars = EXFAT_NAME_PART_LEN;
        uint16_t *sname = wname;

        for (i = 0; i < ds.stream.name_size; i++)
                wname[i] = host2uint16_t_le(wname[i]);

        for (i = 0; i < df.file.count - 1; i++) {
                rc = exfat_directory_next(di);
                if (rc != EOK)
                        return rc;

                if (i == df.file.count - 2) {
                        chars = ds.stream.name_size -
                            EXFAT_NAME_PART_LEN * (df.file.count - 2);
                }

                rc = exfat_directory_get(di, &de);
                if (rc != EOK)
                        return rc;
                de->type = EXFAT_TYPE_NAME;
                /* test */
                for (j = 0; j < chars; j++) {
                        de->name.name[j] = *sname;
                        sname++;
                }

                di->b->dirty = true;
        }

        return exfat_directory_seek(di, pos);
}

errno_t exfat_directory_erase_file(exfat_directory_t *di, aoff64_t pos)
{
        errno_t rc;
        int count;
        exfat_dentry_t *de;

        di->pos = pos;

        rc = exfat_directory_get(di, &de);
        if (rc != EOK)
                return rc;
        count = de->file.count + 1;

        while (count) {
                rc = exfat_directory_get(di, &de);
                if (rc != EOK)
                        return rc;
                de->type &= ~EXFAT_TYPE_USED;
                di->b->dirty = true;

                rc = exfat_directory_next(di);
                if (rc != EOK)
                        return rc;
                count--;
        }
        return EOK;
}

errno_t exfat_directory_expand(exfat_directory_t *di)
{
        errno_t rc;

        if (!di->nodep)
                return ENOSPC;

        rc = exfat_node_expand(di->nodep->idx->service_id, di->nodep, 1);
        if (rc != EOK)
                return rc;

        di->fragmented = di->nodep->fragmented;
        di->nodep->size += BPC(di->bs);
        di->nodep->dirty = true;                /* need to sync node */
        di->blocks = di->nodep->size / BPS(di->bs);

        return EOK;
}

errno_t exfat_directory_lookup_free(exfat_directory_t *di, size_t count)
{
        errno_t rc;
        exfat_dentry_t *d;
        size_t found;
        aoff64_t pos;

        rc = exfat_directory_seek(di, 0);
        if (rc != EOK)
                return rc;

        do {
                found = 0;
                pos = 0;
                do {
                        if (exfat_directory_get(di, &d) == EOK) {
                                switch (exfat_classify_dentry(d)) {
                                case EXFAT_DENTRY_LAST:
                                case EXFAT_DENTRY_FREE:
                                        if (found == 0)
                                                pos = di->pos;
                                        found++;
                                        if (found == count) {
                                                exfat_directory_seek(di, pos);
                                                return EOK;
                                        }
                                        break;
                                default:
                                        found = 0;
                                        break;
                                }
                        }
                } while (exfat_directory_next(di) == EOK);
        } while (exfat_directory_expand(di) == EOK);
        return ENOSPC;
}

/**
 * @}
 */