/*
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* YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
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*
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* Copyright (C) 2002-2011 Aleph One Ltd.
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* for Toby Churchill Ltd and Brightstar Engineering
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*
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* Created by Charles Manning <charles@aleph1.co.uk>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include "yaffs_packedtags2.h"
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#include "yportenv.h"
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#include "yaffs_trace.h"
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/* This code packs a set of extended tags into a binary structure for
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* NAND storage
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*/
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/* Some of the information is "extra" struff which can be packed in to
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* speed scanning
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* This is defined by having the EXTRA_HEADER_INFO_FLAG set.
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*/
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/* Extra flags applied to chunk_id */
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#define EXTRA_HEADER_INFO_FLAG 0x80000000
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#define EXTRA_SHRINK_FLAG 0x40000000
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#define EXTRA_SHADOWS_FLAG 0x20000000
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#define EXTRA_SPARE_FLAGS 0x10000000
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#define ALL_EXTRA_FLAGS 0xf0000000
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/* Also, the top 4 bits of the object Id are set to the object type. */
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#define EXTRA_OBJECT_TYPE_SHIFT (28)
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#define EXTRA_OBJECT_TYPE_MASK ((0x0f) << EXTRA_OBJECT_TYPE_SHIFT)
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static void yaffs_dump_packed_tags2_tags_only(
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const struct yaffs_packed_tags2_tags_only *ptt)
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{
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yaffs_trace(YAFFS_TRACE_MTD,
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"packed tags obj %d chunk %d byte %d seq %d",
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ptt->obj_id, ptt->chunk_id, ptt->n_bytes, ptt->seq_number);
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}
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static void yaffs_dump_packed_tags2(const struct yaffs_packed_tags2 *pt)
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{
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yaffs_dump_packed_tags2_tags_only(&pt->t);
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}
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static void yaffs_dump_tags2(const struct yaffs_ext_tags *t)
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{
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yaffs_trace(YAFFS_TRACE_MTD,
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"ext.tags eccres %d blkbad %d chused %d obj %d chunk%d byte %d del %d ser %d seq %d",
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t->ecc_result, t->block_bad, t->chunk_used, t->obj_id,
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t->chunk_id, t->n_bytes, t->is_deleted, t->serial_number,
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t->seq_number);
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}
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static int yaffs_check_tags_extra_packable(const struct yaffs_ext_tags *t)
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{
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if (t->chunk_id != 0 || !t->extra_available)
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return 0;
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/* Check if the file size is too long to store */
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if (t->extra_obj_type == YAFFS_OBJECT_TYPE_FILE &&
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(t->extra_file_size >> 31) != 0)
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return 0;
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return 1;
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}
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void yaffs_pack_tags2_tags_only(struct yaffs_packed_tags2_tags_only *ptt,
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const struct yaffs_ext_tags *t)
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{
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ptt->chunk_id = t->chunk_id;
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ptt->seq_number = t->seq_number;
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ptt->n_bytes = t->n_bytes;
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ptt->obj_id = t->obj_id;
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/* Only store extra tags for object headers.
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* If it is a file then only store if the file size is short\
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* enough to fit.
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*/
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if (yaffs_check_tags_extra_packable(t)) {
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/* Store the extra header info instead */
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/* We save the parent object in the chunk_id */
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ptt->chunk_id = EXTRA_HEADER_INFO_FLAG | t->extra_parent_id;
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if (t->extra_is_shrink)
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ptt->chunk_id |= EXTRA_SHRINK_FLAG;
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if (t->extra_shadows)
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ptt->chunk_id |= EXTRA_SHADOWS_FLAG;
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ptt->obj_id &= ~EXTRA_OBJECT_TYPE_MASK;
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ptt->obj_id |= (t->extra_obj_type << EXTRA_OBJECT_TYPE_SHIFT);
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if (t->extra_obj_type == YAFFS_OBJECT_TYPE_HARDLINK)
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ptt->n_bytes = t->extra_equiv_id;
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else if (t->extra_obj_type == YAFFS_OBJECT_TYPE_FILE)
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ptt->n_bytes = (unsigned) t->extra_file_size;
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else
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ptt->n_bytes = 0;
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}
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yaffs_dump_packed_tags2_tags_only(ptt);
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yaffs_dump_tags2(t);
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}
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void yaffs_pack_tags2(struct yaffs_packed_tags2 *pt,
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const struct yaffs_ext_tags *t, int tags_ecc)
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{
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yaffs_pack_tags2_tags_only(&pt->t, t);
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if (tags_ecc)
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yaffs_ecc_calc_other((unsigned char *)&pt->t,
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sizeof(struct yaffs_packed_tags2_tags_only),
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&pt->ecc);
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}
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void yaffs_unpack_tags2_tags_only(struct yaffs_ext_tags *t,
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struct yaffs_packed_tags2_tags_only *ptt)
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{
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memset(t, 0, sizeof(struct yaffs_ext_tags));
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if (ptt->seq_number == 0xffffffff)
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return;
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t->block_bad = 0;
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t->chunk_used = 1;
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t->obj_id = ptt->obj_id;
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t->chunk_id = ptt->chunk_id;
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t->n_bytes = ptt->n_bytes;
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t->is_deleted = 0;
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t->serial_number = 0;
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t->seq_number = ptt->seq_number;
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/* Do extra header info stuff */
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if (ptt->chunk_id & EXTRA_HEADER_INFO_FLAG) {
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t->chunk_id = 0;
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t->n_bytes = 0;
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t->extra_available = 1;
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t->extra_parent_id = ptt->chunk_id & (~(ALL_EXTRA_FLAGS));
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t->extra_is_shrink = ptt->chunk_id & EXTRA_SHRINK_FLAG ? 1 : 0;
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t->extra_shadows = ptt->chunk_id & EXTRA_SHADOWS_FLAG ? 1 : 0;
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t->extra_obj_type = ptt->obj_id >> EXTRA_OBJECT_TYPE_SHIFT;
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t->obj_id &= ~EXTRA_OBJECT_TYPE_MASK;
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if (t->extra_obj_type == YAFFS_OBJECT_TYPE_HARDLINK)
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t->extra_equiv_id = ptt->n_bytes;
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else
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t->extra_file_size = ptt->n_bytes;
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}
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yaffs_dump_packed_tags2_tags_only(ptt);
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yaffs_dump_tags2(t);
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}
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void yaffs_unpack_tags2(struct yaffs_ext_tags *t, struct yaffs_packed_tags2 *pt,
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int tags_ecc)
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{
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enum yaffs_ecc_result ecc_result = YAFFS_ECC_RESULT_NO_ERROR;
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if (pt->t.seq_number != 0xffffffff && tags_ecc) {
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/* Chunk is in use and we need to do ECC */
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struct yaffs_ecc_other ecc;
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int result;
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yaffs_ecc_calc_other((unsigned char *)&pt->t,
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sizeof(struct yaffs_packed_tags2_tags_only),
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&ecc);
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result =
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yaffs_ecc_correct_other((unsigned char *)&pt->t,
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sizeof(struct yaffs_packed_tags2_tags_only),
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&pt->ecc, &ecc);
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switch (result) {
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case 0:
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ecc_result = YAFFS_ECC_RESULT_NO_ERROR;
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break;
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case 1:
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ecc_result = YAFFS_ECC_RESULT_FIXED;
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break;
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case -1:
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ecc_result = YAFFS_ECC_RESULT_UNFIXED;
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break;
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default:
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ecc_result = YAFFS_ECC_RESULT_UNKNOWN;
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}
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}
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yaffs_unpack_tags2_tags_only(t, &pt->t);
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t->ecc_result = ecc_result;
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yaffs_dump_packed_tags2(pt);
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yaffs_dump_tags2(t);
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}
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