/*
   * 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
  ",
  			  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)
  ",
  			  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]
  ",
  			  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!
  ");
  		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
  ");
  
  	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
  ");
  		if (!(mdata->s_flags & MF_MIRROR_FE_LOADED)) {
  			mdata->s_mirror_fe = udf_find_metadata_inode_efe(sb,
  				mdata->s_mirror_file_loc, map->s_partition_num);
  			mdata->s_flags |= MF_MIRROR_FE_LOADED;
  		}
  
  		inode = mdata->s_mirror_fe;
  		if (!inode)
  			return 0xFFFFFFFF;
  		retblk = udf_try_read_meta(inode, block, partition, offset);
  	}
  
  	return retblk;
  }