[linux-2.6-block.git] / fs / udf / partition.c

/*
 * partition.c
 *
 * PURPOSE
 *      Partition handling routines for the OSTA-UDF(tm) filesystem.
 *
 * COPYRIGHT
 *      This file is distributed under the terms of the GNU General Public
 *      License (GPL). Copies of the GPL can be obtained from:
 *              ftp://prep.ai.mit.edu/pub/gnu/GPL
 *      Each contributing author retains all rights to their own work.
 *
 *  (C) 1998-2001 Ben Fennema
 *
 * HISTORY
 *
 * 12/06/98 blf  Created file.
 *
 */

#include "udfdecl.h"
#include "udf_sb.h"
#include "udf_i.h"

#include <linux/fs.h>
#include <linux/string.h>
#include <linux/buffer_head.h>
#include <linux/mutex.h>

uint32_t udf_get_pblock(struct super_block *sb, uint32_t block,
			uint16_t partition, uint32_t offset)
{
	struct udf_sb_info *sbi = UDF_SB(sb);
	struct udf_part_map *map;
	if (partition >= sbi->s_partitions) {
		udf_debug("block=%d, partition=%d, offset=%d: invalid partition\n",
			  block, partition, offset);
		return 0xFFFFFFFF;
	}
	map = &sbi->s_partmaps[partition];
	if (map->s_partition_func)
		return map->s_partition_func(sb, block, partition, offset);
	else
		return map->s_partition_root + block + offset;
}

uint32_t udf_get_pblock_virt15(struct super_block *sb, uint32_t block,
			       uint16_t partition, uint32_t offset)
{
	struct buffer_head *bh = NULL;
	uint32_t newblock;
	uint32_t index;
	uint32_t loc;
	struct udf_sb_info *sbi = UDF_SB(sb);
	struct udf_part_map *map;
	struct udf_virtual_data *vdata;
	struct udf_inode_info *iinfo = UDF_I(sbi->s_vat_inode);

	map = &sbi->s_partmaps[partition];
	vdata = &map->s_type_specific.s_virtual;

	if (block > vdata->s_num_entries) {
		udf_debug("Trying to access block beyond end of VAT (%d max %d)\n",
			  block, vdata->s_num_entries);
		return 0xFFFFFFFF;
	}

	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
		loc = le32_to_cpu(((__le32 *)(iinfo->i_ext.i_data +
			vdata->s_start_offset))[block]);
		goto translate;
	}
	index = (sb->s_blocksize - vdata->s_start_offset) / sizeof(uint32_t);
	if (block >= index) {
		block -= index;
		newblock = 1 + (block / (sb->s_blocksize / sizeof(uint32_t)));
		index = block % (sb->s_blocksize / sizeof(uint32_t));
	} else {
		newblock = 0;
		index = vdata->s_start_offset / sizeof(uint32_t) + block;
	}

	loc = udf_block_map(sbi->s_vat_inode, newblock);

	bh = sb_bread(sb, loc);
	if (!bh) {
		udf_debug("get_pblock(UDF_VIRTUAL_MAP:%p,%d,%d) VAT: %d[%d]\n",
			  sb, block, partition, loc, index);
		return 0xFFFFFFFF;
	}

	loc = le32_to_cpu(((__le32 *)bh->b_data)[index]);

	brelse(bh);

translate:
	if (iinfo->i_location.partitionReferenceNum == partition) {
		udf_debug("recursive call to udf_get_pblock!\n");
		return 0xFFFFFFFF;
	}

	return udf_get_pblock(sb, loc,
			      iinfo->i_location.partitionReferenceNum,
			      offset);
}

inline uint32_t udf_get_pblock_virt20(struct super_block *sb, uint32_t block,
				      uint16_t partition, uint32_t offset)
{
	return udf_get_pblock_virt15(sb, block, partition, offset);
}

uint32_t udf_get_pblock_spar15(struct super_block *sb, uint32_t block,
			       uint16_t partition, uint32_t offset)
{
	int i;
	struct sparingTable *st = NULL;
	struct udf_sb_info *sbi = UDF_SB(sb);
	struct udf_part_map *map;
	uint32_t packet;
	struct udf_sparing_data *sdata;

	map = &sbi->s_partmaps[partition];
	sdata = &map->s_type_specific.s_sparing;
	packet = (block + offset) & ~(sdata->s_packet_len - 1);

	for (i = 0; i < 4; i++) {
		if (sdata->s_spar_map[i] != NULL) {
			st = (struct sparingTable *)
					sdata->s_spar_map[i]->b_data;
			break;
		}
	}

	if (st) {
		for (i = 0; i < le16_to_cpu(st->reallocationTableLen); i++) {
			struct sparingEntry *entry = &st->mapEntry[i];
			u32 origLoc = le32_to_cpu(entry->origLocation);
			if (origLoc >= 0xFFFFFFF0)
				break;
			else if (origLoc == packet)
				return le32_to_cpu(entry->mappedLocation) +
					((block + offset) &
						(sdata->s_packet_len - 1));
			else if (origLoc > packet)
				break;
		}
	}

	return map->s_partition_root + block + offset;
}

int udf_relocate_blocks(struct super_block *sb, long old_block, long *new_block)
{
	struct udf_sparing_data *sdata;
	struct sparingTable *st = NULL;
	struct sparingEntry mapEntry;
	uint32_t packet;
	int i, j, k, l;
	struct udf_sb_info *sbi = UDF_SB(sb);
	u16 reallocationTableLen;
	struct buffer_head *bh;
	int ret = 0;

	mutex_lock(&sbi->s_alloc_mutex);
	for (i = 0; i < sbi->s_partitions; i++) {
		struct udf_part_map *map = &sbi->s_partmaps[i];
		if (old_block > map->s_partition_root &&
		    old_block < map->s_partition_root + map->s_partition_len) {
			sdata = &map->s_type_specific.s_sparing;
			packet = (old_block - map->s_partition_root) &
						~(sdata->s_packet_len - 1);

			for (j = 0; j < 4; j++)
				if (sdata->s_spar_map[j] != NULL) {
					st = (struct sparingTable *)
						sdata->s_spar_map[j]->b_data;
					break;
				}

			if (!st) {
				ret = 1;
				goto out;
			}

			reallocationTableLen =
					le16_to_cpu(st->reallocationTableLen);
			for (k = 0; k < reallocationTableLen; k++) {
				struct sparingEntry *entry = &st->mapEntry[k];
				u32 origLoc = le32_to_cpu(entry->origLocation);

				if (origLoc == 0xFFFFFFFF) {
					for (; j < 4; j++) {
						int len;
						bh = sdata->s_spar_map[j];
						if (!bh)
							continue;

						st = (struct sparingTable *)
								bh->b_data;
						entry->origLocation =
							cpu_to_le32(packet);
						len =
						  sizeof(struct sparingTable) +
						  reallocationTableLen *
						  sizeof(struct sparingEntry);
						udf_update_tag((char *)st, len);
						mark_buffer_dirty(bh);
					}
					*new_block = le32_to_cpu(
							entry->mappedLocation) +
						     ((old_block -
							map->s_partition_root) &
						     (sdata->s_packet_len - 1));
					ret = 0;
					goto out;
				} else if (origLoc == packet) {
					*new_block = le32_to_cpu(
							entry->mappedLocation) +
						     ((old_block -
							map->s_partition_root) &
						     (sdata->s_packet_len - 1));
					ret = 0;
					goto out;
				} else if (origLoc > packet)
					break;
			}

			for (l = k; l < reallocationTableLen; l++) {
				struct sparingEntry *entry = &st->mapEntry[l];
				u32 origLoc = le32_to_cpu(entry->origLocation);

				if (origLoc != 0xFFFFFFFF)
					continue;

				for (; j < 4; j++) {
					bh = sdata->s_spar_map[j];
					if (!bh)
						continue;

					st = (struct sparingTable *)bh->b_data;
					mapEntry = st->mapEntry[l];
					mapEntry.origLocation =
							cpu_to_le32(packet);
					memmove(&st->mapEntry[k + 1],
						&st->mapEntry[k],
						(l - k) *
						sizeof(struct sparingEntry));
					st->mapEntry[k] = mapEntry;
					udf_update_tag((char *)st,
						sizeof(struct sparingTable) +
						reallocationTableLen *
						sizeof(struct sparingEntry));
					mark_buffer_dirty(bh);
				}
				*new_block =
					le32_to_cpu(
					      st->mapEntry[k].mappedLocation) +
					((old_block - map->s_partition_root) &
					 (sdata->s_packet_len - 1));
				ret = 0;
				goto out;
			}

			ret = 1;
			goto out;
		} /* if old_block */
	}

	if (i == sbi->s_partitions) {
		/* outside of partitions */
		/* for now, fail =) */
		ret = 1;
	}

out:
	mutex_unlock(&sbi->s_alloc_mutex);
	return ret;
}

static uint32_t udf_try_read_meta(struct inode *inode, uint32_t block,
					uint16_t partition, uint32_t offset)
{
	struct super_block *sb = inode->i_sb;
	struct udf_part_map *map;
	struct kernel_lb_addr eloc;
	uint32_t elen;
	sector_t ext_offset;
	struct extent_position epos = {};
	uint32_t phyblock;

	if (inode_bmap(inode, block, &epos, &eloc, &elen, &ext_offset) !=
						(EXT_RECORDED_ALLOCATED >> 30))
		phyblock = 0xFFFFFFFF;
	else {
		map = &UDF_SB(sb)->s_partmaps[partition];
		/* map to sparable/physical partition desc */
		phyblock = udf_get_pblock(sb, eloc.logicalBlockNum,
			map->s_partition_num, ext_offset + offset);
	}

	brelse(epos.bh);
	return phyblock;
}

uint32_t udf_get_pblock_meta25(struct super_block *sb, uint32_t block,
				uint16_t partition, uint32_t offset)
{
	struct udf_sb_info *sbi = UDF_SB(sb);
	struct udf_part_map *map;
	struct udf_meta_data *mdata;
	uint32_t retblk;
	struct inode *inode;

	udf_debug("READING from METADATA\n");

	map = &sbi->s_partmaps[partition];
	mdata = &map->s_type_specific.s_metadata;
	inode = mdata->s_metadata_fe ? : mdata->s_mirror_fe;

	/* We shouldn't mount such media... */
	BUG_ON(!inode);
	retblk = udf_try_read_meta(inode, block, partition, offset);
	if (retblk == 0xFFFFFFFF && mdata->s_metadata_fe) {
		udf_warn(sb, "error reading from METADATA, trying to read from MIRROR\n");
		if (!mdata->s_mirror_loaded_flag) {
			mdata->s_mirror_fe = udf_find_metadata_inode_efe(sb,
				mdata->s_mirror_file_loc, map->s_partition_num);
			mdata->s_mirror_loaded_flag = 1;
		}

		inode = mdata->s_mirror_fe;
		if (!inode)
			return 0xFFFFFFFF;
		retblk = udf_try_read_meta(inode, block, partition, offset);
	}

	return retblk;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* partition.c
	3	*
	4	* PURPOSE
	5	* Partition handling routines for the OSTA-UDF(tm) filesystem.
	6	*
1da177e4 LT	7	* COPYRIGHT
	8	* This file is distributed under the terms of the GNU General Public
	9	* License (GPL). Copies of the GPL can be obtained from:
	10	* ftp://prep.ai.mit.edu/pub/gnu/GPL
	11	* Each contributing author retains all rights to their own work.
	12	*
	13	* (C) 1998-2001 Ben Fennema
	14	*
	15	* HISTORY
	16	*
28de7948	17	* 12/06/98 blf Created file.
1da177e4 LT	18	*
	19	*/
	20
	21	#include "udfdecl.h"
	22	#include "udf_sb.h"
	23	#include "udf_i.h"
	24
	25	#include <linux/fs.h>
	26	#include <linux/string.h>
1da177e4	27	#include <linux/buffer_head.h>
7db09be6	28	#include <linux/mutex.h>
1da177e4	29
22ba0317 AB	30	uint32_t udf_get_pblock(struct super_block *sb, uint32_t block,
22ba0317 AB	31	uint16_t partition, uint32_t offset)
1da177e4	32	{
6c79e987 MS	33	struct udf_sb_info *sbi = UDF_SB(sb);
	34	struct udf_part_map *map;
	35	if (partition >= sbi->s_partitions) {
a983f368 JP	36	udf_debug("block=%d, partition=%d, offset=%d: invalid partition\n",
a983f368 JP	37	block, partition, offset);
1da177e4 LT	38	return 0xFFFFFFFF;
1da177e4 LT	39	}
6c79e987 MS	40	map = &sbi->s_partmaps[partition];
	41	if (map->s_partition_func)
	42	return map->s_partition_func(sb, block, partition, offset);
1da177e4	43	else
6c79e987	44	return map->s_partition_root + block + offset;
1da177e4 LT	45	}
1da177e4 LT	46
28de7948	47	uint32_t udf_get_pblock_virt15(struct super_block *sb, uint32_t block,
cb00ea35	48	uint16_t partition, uint32_t offset)
1da177e4 LT	49	{
	50	struct buffer_head *bh = NULL;
	51	uint32_t newblock;
	52	uint32_t index;
	53	uint32_t loc;
6c79e987 MS	54	struct udf_sb_info *sbi = UDF_SB(sb);
6c79e987 MS	55	struct udf_part_map *map;
4b11111a	56	struct udf_virtual_data *vdata;
fa5e0815	57	struct udf_inode_info *iinfo = UDF_I(sbi->s_vat_inode);
1da177e4	58
6c79e987	59	map = &sbi->s_partmaps[partition];
4b11111a	60	vdata = &map->s_type_specific.s_virtual;
1da177e4	61
4b11111a	62	if (block > vdata->s_num_entries) {
a983f368 JP	63	udf_debug("Trying to access block beyond end of VAT (%d max %d)\n",
a983f368 JP	64	block, vdata->s_num_entries);
1da177e4 LT	65	return 0xFFFFFFFF;
	66	}
	67
fa5e0815	68	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
47c9358a SM	69	loc = le32_to_cpu(((__le32 *)(iinfo->i_ext.i_data +
47c9358a SM	70	vdata->s_start_offset))[block]);
fa5e0815 JK	71	goto translate;
	72	}
	73	index = (sb->s_blocksize - vdata->s_start_offset) / sizeof(uint32_t);
cb00ea35	74	if (block >= index) {
1da177e4 LT	75	block -= index;
	76	newblock = 1 + (block / (sb->s_blocksize / sizeof(uint32_t)));
	77	index = block % (sb->s_blocksize / sizeof(uint32_t));
cb00ea35	78	} else {
1da177e4	79	newblock = 0;
4b11111a	80	index = vdata->s_start_offset / sizeof(uint32_t) + block;
1da177e4 LT	81	}
1da177e4 LT	82
6c79e987	83	loc = udf_block_map(sbi->s_vat_inode, newblock);
1da177e4	84
4b11111a MS	85	bh = sb_bread(sb, loc);
4b11111a MS	86	if (!bh) {
1da177e4	87	udf_debug("get_pblock(UDF_VIRTUAL_MAP:%p,%d,%d) VAT: %d[%d]\n",
cb00ea35	88	sb, block, partition, loc, index);
1da177e4 LT	89	return 0xFFFFFFFF;
	90	}
	91
28de7948	92	loc = le32_to_cpu(((__le32 *)bh->b_data)[index]);
1da177e4	93
3bf25cb4	94	brelse(bh);
1da177e4	95
fa5e0815	96	translate:
48d6d8ff	97	if (iinfo->i_location.partitionReferenceNum == partition) {
1da177e4 LT	98	udf_debug("recursive call to udf_get_pblock!\n");
	99	return 0xFFFFFFFF;
	100	}
	101
cb00ea35	102	return udf_get_pblock(sb, loc,
48d6d8ff	103	iinfo->i_location.partitionReferenceNum,
28de7948	104	offset);
1da177e4 LT	105	}
1da177e4 LT	106
4b11111a	107	inline uint32_t udf_get_pblock_virt20(struct super_block *sb, uint32_t block,
cb00ea35	108	uint16_t partition, uint32_t offset)
1da177e4 LT	109	{
	110	return udf_get_pblock_virt15(sb, block, partition, offset);
	111	}
	112
6c79e987	113	uint32_t udf_get_pblock_spar15(struct super_block *sb, uint32_t block,
cb00ea35	114	uint16_t partition, uint32_t offset)
1da177e4 LT	115	{
	116	int i;
	117	struct sparingTable *st = NULL;
6c79e987 MS	118	struct udf_sb_info *sbi = UDF_SB(sb);
	119	struct udf_part_map *map;
	120	uint32_t packet;
4b11111a	121	struct udf_sparing_data *sdata;
6c79e987 MS	122
6c79e987 MS	123	map = &sbi->s_partmaps[partition];
4b11111a MS	124	sdata = &map->s_type_specific.s_sparing;
4b11111a MS	125	packet = (block + offset) & ~(sdata->s_packet_len - 1);
1da177e4	126
cb00ea35	127	for (i = 0; i < 4; i++) {
4b11111a MS	128	if (sdata->s_spar_map[i] != NULL) {
	129	st = (struct sparingTable *)
	130	sdata->s_spar_map[i]->b_data;
1da177e4 LT	131	break;
	132	}
	133	}
	134
cb00ea35 CG	135	if (st) {
cb00ea35 CG	136	for (i = 0; i < le16_to_cpu(st->reallocationTableLen); i++) {
4b11111a MS	137	struct sparingEntry *entry = &st->mapEntry[i];
	138	u32 origLoc = le32_to_cpu(entry->origLocation);
	139	if (origLoc >= 0xFFFFFFF0)
1da177e4	140	break;
4b11111a MS	141	else if (origLoc == packet)
	142	return le32_to_cpu(entry->mappedLocation) +
	143	((block + offset) &
	144	(sdata->s_packet_len - 1));
	145	else if (origLoc > packet)
1da177e4 LT	146	break;
	147	}
	148	}
28de7948	149
6c79e987	150	return map->s_partition_root + block + offset;
1da177e4 LT	151	}
	152
	153	int udf_relocate_blocks(struct super_block sb, long old_block, long new_block)
	154	{
	155	struct udf_sparing_data *sdata;
	156	struct sparingTable *st = NULL;
	157	struct sparingEntry mapEntry;
	158	uint32_t packet;
	159	int i, j, k, l;
6c79e987	160	struct udf_sb_info *sbi = UDF_SB(sb);
4b11111a MS	161	u16 reallocationTableLen;
4b11111a MS	162	struct buffer_head *bh;
7db09be6	163	int ret = 0;
1da177e4	164
7db09be6	165	mutex_lock(&sbi->s_alloc_mutex);
6c79e987 MS	166	for (i = 0; i < sbi->s_partitions; i++) {
	167	struct udf_part_map *map = &sbi->s_partmaps[i];
	168	if (old_block > map->s_partition_root &&
	169	old_block < map->s_partition_root + map->s_partition_len) {
	170	sdata = &map->s_type_specific.s_sparing;
4b11111a MS	171	packet = (old_block - map->s_partition_root) &
4b11111a MS	172	~(sdata->s_packet_len - 1);
cb00ea35	173
4b11111a MS	174	for (j = 0; j < 4; j++)
	175	if (sdata->s_spar_map[j] != NULL) {
	176	st = (struct sparingTable *)
	177	sdata->s_spar_map[j]->b_data;
1da177e4 LT	178	break;
1da177e4 LT	179	}
1da177e4	180
7db09be6 AIB	181	if (!st) {
	182	ret = 1;
	183	goto out;
	184	}
1da177e4	185
4b11111a MS	186	reallocationTableLen =
	187	le16_to_cpu(st->reallocationTableLen);
	188	for (k = 0; k < reallocationTableLen; k++) {
	189	struct sparingEntry *entry = &st->mapEntry[k];
	190	u32 origLoc = le32_to_cpu(entry->origLocation);
	191
	192	if (origLoc == 0xFFFFFFFF) {
cb00ea35	193	for (; j < 4; j++) {
4b11111a MS	194	int len;
	195	bh = sdata->s_spar_map[j];
	196	if (!bh)
	197	continue;
	198
	199	st = (struct sparingTable *)
	200	bh->b_data;
	201	entry->origLocation =
	202	cpu_to_le32(packet);
	203	len =
	204	sizeof(struct sparingTable) +
	205	reallocationTableLen *
	206	sizeof(struct sparingEntry);
	207	udf_update_tag((char *)st, len);
	208	mark_buffer_dirty(bh);
1da177e4	209	}
4b11111a MS	210	*new_block = le32_to_cpu(
	211	entry->mappedLocation) +
	212	((old_block -
	213	map->s_partition_root) &
	214	(sdata->s_packet_len - 1));
7db09be6 AIB	215	ret = 0;
7db09be6 AIB	216	goto out;
4b11111a MS	217	} else if (origLoc == packet) {
	218	*new_block = le32_to_cpu(
	219	entry->mappedLocation) +
	220	((old_block -
	221	map->s_partition_root) &
	222	(sdata->s_packet_len - 1));
7db09be6 AIB	223	ret = 0;
7db09be6 AIB	224	goto out;
4b11111a	225	} else if (origLoc > packet)
1da177e4 LT	226	break;
1da177e4 LT	227	}
28de7948	228
4b11111a MS	229	for (l = k; l < reallocationTableLen; l++) {
	230	struct sparingEntry *entry = &st->mapEntry[l];
	231	u32 origLoc = le32_to_cpu(entry->origLocation);
	232
	233	if (origLoc != 0xFFFFFFFF)
	234	continue;
	235
	236	for (; j < 4; j++) {
	237	bh = sdata->s_spar_map[j];
	238	if (!bh)
	239	continue;
	240
	241	st = (struct sparingTable *)bh->b_data;
	242	mapEntry = st->mapEntry[l];
	243	mapEntry.origLocation =
	244	cpu_to_le32(packet);
	245	memmove(&st->mapEntry[k + 1],
	246	&st->mapEntry[k],
	247	(l - k) *
	248	sizeof(struct sparingEntry));
	249	st->mapEntry[k] = mapEntry;
	250	udf_update_tag((char *)st,
	251	sizeof(struct sparingTable) +
	252	reallocationTableLen *
	253	sizeof(struct sparingEntry));
	254	mark_buffer_dirty(bh);
1da177e4	255	}
4b11111a MS	256	*new_block =
	257	le32_to_cpu(
	258	st->mapEntry[k].mappedLocation) +
	259	((old_block - map->s_partition_root) &
	260	(sdata->s_packet_len - 1));
7db09be6 AIB	261	ret = 0;
7db09be6 AIB	262	goto out;
1da177e4	263	}
28de7948	264
7db09be6 AIB	265	ret = 1;
7db09be6 AIB	266	goto out;
28de7948	267	} /* if old_block */
1da177e4	268	}
28de7948	269
6c79e987	270	if (i == sbi->s_partitions) {
1da177e4 LT	271	/* outside of partitions */
1da177e4 LT	272	/* for now, fail =) */
7db09be6	273	ret = 1;
1da177e4 LT	274	}
1da177e4 LT	275
7db09be6 AIB	276	out:
	277	mutex_unlock(&sbi->s_alloc_mutex);
	278	return ret;
1da177e4	279	}
bfb257a5 JK	280
	281	static uint32_t udf_try_read_meta(struct inode *inode, uint32_t block,
	282	uint16_t partition, uint32_t offset)
	283	{
	284	struct super_block *sb = inode->i_sb;
	285	struct udf_part_map *map;
5ca4e4be	286	struct kernel_lb_addr eloc;
bfb257a5 JK	287	uint32_t elen;
	288	sector_t ext_offset;
	289	struct extent_position epos = {};
	290	uint32_t phyblock;
	291
	292	if (inode_bmap(inode, block, &epos, &eloc, &elen, &ext_offset) !=
	293	(EXT_RECORDED_ALLOCATED >> 30))
	294	phyblock = 0xFFFFFFFF;
	295	else {
	296	map = &UDF_SB(sb)->s_partmaps[partition];
	297	/* map to sparable/physical partition desc */
	298	phyblock = udf_get_pblock(sb, eloc.logicalBlockNum,
	299	map->s_partition_num, ext_offset + offset);
	300	}
	301
	302	brelse(epos.bh);
	303	return phyblock;
	304	}
	305
	306	uint32_t udf_get_pblock_meta25(struct super_block *sb, uint32_t block,
	307	uint16_t partition, uint32_t offset)
	308	{
	309	struct udf_sb_info *sbi = UDF_SB(sb);
	310	struct udf_part_map *map;
	311	struct udf_meta_data *mdata;
	312	uint32_t retblk;
	313	struct inode *inode;
	314
	315	udf_debug("READING from METADATA\n");
	316
	317	map = &sbi->s_partmaps[partition];
	318	mdata = &map->s_type_specific.s_metadata;
	319	inode = mdata->s_metadata_fe ? : mdata->s_mirror_fe;
	320
	321	/* We shouldn't mount such media... */
	322	BUG_ON(!inode);
	323	retblk = udf_try_read_meta(inode, block, partition, offset);
3080a74e	324	if (retblk == 0xFFFFFFFF && mdata->s_metadata_fe) {
a40ecd7b	325	udf_warn(sb, "error reading from METADATA, trying to read from MIRROR\n");
3080a74e NJ	326	if (!mdata->s_mirror_loaded_flag) {
	327	mdata->s_mirror_fe = udf_find_metadata_inode_efe(sb,
	328	mdata->s_mirror_file_loc, map->s_partition_num);
	329	mdata->s_mirror_loaded_flag = 1;
	330	}
	331
bfb257a5 JK	332	inode = mdata->s_mirror_fe;
	333	if (!inode)
	334	return 0xFFFFFFFF;
	335	retblk = udf_try_read_meta(inode, block, partition, offset);
	336	}
	337
	338	return retblk;
	339	}