2 * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
4 * Copyright (C) 2002-2011 Aleph One Ltd.
5 * for Toby Churchill Ltd and Brightstar Engineering
7 * Created by Charles Manning <charles@aleph1.co.uk>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
14 #include "yaffs_packedtags2.h"
16 #include "yaffs_trace.h"
17 #include "yaffs_endian.h"
19 /* This code packs a set of extended tags into a binary structure for
23 /* Some of the information is "extra" struff which can be packed in to
25 * This is defined by having the EXTRA_HEADER_INFO_FLAG set.
28 /* Extra flags applied to chunk_id */
30 #define EXTRA_HEADER_INFO_FLAG 0x80000000
31 #define EXTRA_SHRINK_FLAG 0x40000000
32 #define EXTRA_SHADOWS_FLAG 0x20000000
33 #define EXTRA_SPARE_FLAGS 0x10000000
35 #define ALL_EXTRA_FLAGS 0xf0000000
37 /* Also, the top 4 bits of the object Id are set to the object type. */
38 #define EXTRA_OBJECT_TYPE_SHIFT (28)
39 #define EXTRA_OBJECT_TYPE_MASK ((0x0f) << EXTRA_OBJECT_TYPE_SHIFT)
41 static void yaffs_dump_packed_tags2_tags_only(
42 const struct yaffs_packed_tags2_tags_only *ptt)
44 yaffs_trace(YAFFS_TRACE_MTD,
45 "packed tags obj %d chunk %d byte %d seq %d",
46 ptt->obj_id, ptt->chunk_id, ptt->n_bytes, ptt->seq_number);
49 static void yaffs_dump_packed_tags2(const struct yaffs_packed_tags2 *pt)
51 yaffs_dump_packed_tags2_tags_only(&pt->t);
54 static void yaffs_dump_tags2(const struct yaffs_ext_tags *t)
56 yaffs_trace(YAFFS_TRACE_MTD,
57 "ext.tags eccres %d blkbad %d chused %d obj %d chunk%d byte %d del %d ser %d seq %d",
58 t->ecc_result, t->block_bad, t->chunk_used, t->obj_id,
59 t->chunk_id, t->n_bytes, t->is_deleted, t->serial_number,
64 static int yaffs_check_tags_extra_packable(const struct yaffs_ext_tags *t)
66 if (t->chunk_id != 0 || !t->extra_available)
69 /* Check if the file size is too long to store */
70 if (t->extra_obj_type == YAFFS_OBJECT_TYPE_FILE &&
71 (t->extra_file_size >> 31) != 0)
76 void yaffs_pack_tags2_tags_only(struct yaffs_dev *dev,
77 struct yaffs_packed_tags2_tags_only *ptt,
78 const struct yaffs_ext_tags *t)
80 ptt->chunk_id = t->chunk_id;
81 ptt->seq_number = t->seq_number;
82 ptt->n_bytes = t->n_bytes;
83 ptt->obj_id = t->obj_id;
85 /* Only store extra tags for object headers.
86 * If it is a file then only store if the file size is short\
89 if (yaffs_check_tags_extra_packable(t)) {
90 /* Store the extra header info instead */
91 /* We save the parent object in the chunk_id */
92 ptt->chunk_id = EXTRA_HEADER_INFO_FLAG | t->extra_parent_id;
93 if (t->extra_is_shrink)
94 ptt->chunk_id |= EXTRA_SHRINK_FLAG;
96 ptt->chunk_id |= EXTRA_SHADOWS_FLAG;
98 ptt->obj_id &= ~EXTRA_OBJECT_TYPE_MASK;
99 ptt->obj_id |= (t->extra_obj_type << EXTRA_OBJECT_TYPE_SHIFT);
101 if (t->extra_obj_type == YAFFS_OBJECT_TYPE_HARDLINK)
102 ptt->n_bytes = t->extra_equiv_id;
103 else if (t->extra_obj_type == YAFFS_OBJECT_TYPE_FILE)
104 ptt->n_bytes = (unsigned) t->extra_file_size;
109 yaffs_dump_packed_tags2_tags_only(ptt);
111 yaffs_do_endian_packed_tags2(dev, ptt);
114 void yaffs_pack_tags2(struct yaffs_dev *dev,
115 struct yaffs_packed_tags2 *pt,
116 const struct yaffs_ext_tags *t, int tags_ecc)
118 yaffs_pack_tags2_tags_only(dev, &pt->t, t);
121 yaffs_ecc_calc_other((unsigned char *)&pt->t,
122 sizeof(struct yaffs_packed_tags2_tags_only),
126 void yaffs_unpack_tags2_tags_only(struct yaffs_dev *dev,
127 struct yaffs_ext_tags *t,
128 struct yaffs_packed_tags2_tags_only *ptt_ptr)
130 struct yaffs_packed_tags2_tags_only ptt_copy = *ptt_ptr;
132 memset(t, 0, sizeof(struct yaffs_ext_tags));
134 if (ptt_copy.seq_number == 0xffffffff)
137 yaffs_do_endian_packed_tags2(dev, &ptt_copy);
141 t->obj_id = ptt_copy.obj_id;
142 t->chunk_id = ptt_copy.chunk_id;
143 t->n_bytes = ptt_copy.n_bytes;
145 t->serial_number = 0;
146 t->seq_number = ptt_copy.seq_number;
148 /* Do extra header info stuff */
149 if (ptt_copy.chunk_id & EXTRA_HEADER_INFO_FLAG) {
153 t->extra_available = 1;
154 t->extra_parent_id = ptt_copy.chunk_id & (~(ALL_EXTRA_FLAGS));
155 t->extra_is_shrink = ptt_copy.chunk_id & EXTRA_SHRINK_FLAG ? 1 : 0;
156 t->extra_shadows = ptt_copy.chunk_id & EXTRA_SHADOWS_FLAG ? 1 : 0;
157 t->extra_obj_type = ptt_copy.obj_id >> EXTRA_OBJECT_TYPE_SHIFT;
158 t->obj_id &= ~EXTRA_OBJECT_TYPE_MASK;
160 if (t->extra_obj_type == YAFFS_OBJECT_TYPE_HARDLINK)
161 t->extra_equiv_id = ptt_copy.n_bytes;
163 t->extra_file_size = ptt_copy.n_bytes;
165 yaffs_dump_packed_tags2_tags_only(ptt_ptr);
169 void yaffs_unpack_tags2(struct yaffs_dev *dev,
170 struct yaffs_ext_tags *t,
171 struct yaffs_packed_tags2 *pt,
174 enum yaffs_ecc_result ecc_result = YAFFS_ECC_RESULT_NO_ERROR;
176 if (pt->t.seq_number != 0xffffffff && tags_ecc) {
177 /* Chunk is in use and we need to do ECC */
179 struct yaffs_ecc_other ecc;
181 yaffs_ecc_calc_other((unsigned char *)&pt->t,
182 sizeof(struct yaffs_packed_tags2_tags_only),
185 yaffs_ecc_correct_other((unsigned char *)&pt->t,
186 sizeof(struct yaffs_packed_tags2_tags_only),
190 ecc_result = YAFFS_ECC_RESULT_NO_ERROR;
193 ecc_result = YAFFS_ECC_RESULT_FIXED;
196 ecc_result = YAFFS_ECC_RESULT_UNFIXED;
199 ecc_result = YAFFS_ECC_RESULT_UNKNOWN;
202 yaffs_unpack_tags2_tags_only(dev, t, &pt->t);
204 t->ecc_result = ecc_result;
206 yaffs_dump_packed_tags2(pt);