/* * balloc.c * * PURPOSE * Block allocation 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) 1999-2001 Ben Fennema * (C) 1999 Stelias Computing Inc * * HISTORY * * 02/24/99 blf Created. * */ #include "udfdecl.h" #include <linux/bitops.h> #include "udf_i.h" #include "udf_sb.h" #define udf_clear_bit __test_and_clear_bit_le #define udf_set_bit __test_and_set_bit_le #define udf_test_bit test_bit_le #define udf_find_next_one_bit find_next_bit_le static int read_block_bitmap(struct super_block *sb, struct udf_bitmap *bitmap, unsigned int block, unsigned long bitmap_nr) { struct buffer_head *bh = NULL; int retval = 0; struct kernel_lb_addr loc; loc.logicalBlockNum = bitmap->s_extPosition; loc.partitionReferenceNum = UDF_SB(sb)->s_partition; bh = udf_tread(sb, udf_get_lb_pblock(sb, &loc, block)); if (!bh) retval = -EIO; bitmap->s_block_bitmap[bitmap_nr] = bh; return retval; } static int __load_block_bitmap(struct super_block *sb, struct udf_bitmap *bitmap, unsigned int block_group) { int retval = 0; int nr_groups = bitmap->s_nr_groups; if (block_group >= nr_groups) { udf_debug("block_group (%u) > nr_groups (%d)\n", block_group, nr_groups); } if (bitmap->s_block_bitmap[block_group]) return block_group; retval = read_block_bitmap(sb, bitmap, block_group, block_group); if (retval < 0) return retval; return block_group; } static inline int load_block_bitmap(struct super_block *sb, struct udf_bitmap *bitmap, unsigned int block_group) { int slot; slot = __load_block_bitmap(sb, bitmap, block_group); if (slot < 0) return slot; if (!bitmap->s_block_bitmap[slot]) return -EIO; return slot; } static void udf_add_free_space(struct super_block *sb, u16 partition, u32 cnt) { struct udf_sb_info *sbi = UDF_SB(sb); struct logicalVolIntegrityDesc *lvid; if (!sbi->s_lvid_bh) return; lvid = (struct logicalVolIntegrityDesc *)sbi->s_lvid_bh->b_data; le32_add_cpu(&lvid->freeSpaceTable[partition], cnt); udf_updated_lvid(sb); } static void udf_bitmap_free_blocks(struct super_block *sb, struct udf_bitmap *bitmap, struct kernel_lb_addr *bloc, uint32_t offset, uint32_t count) { struct udf_sb_info *sbi = UDF_SB(sb); struct buffer_head *bh = NULL; struct udf_part_map *partmap; unsigned long block; unsigned long block_group; unsigned long bit; unsigned long i; int bitmap_nr; unsigned long overflow; mutex_lock(&sbi->s_alloc_mutex); partmap = &sbi->s_partmaps[bloc->partitionReferenceNum]; if (bloc->logicalBlockNum + count < count || (bloc->logicalBlockNum + count) > partmap->s_partition_len) { udf_debug("%u < %d || %u + %u > %u\n", bloc->logicalBlockNum, 0, bloc->logicalBlockNum, count, partmap->s_partition_len); goto error_return; } block = bloc->logicalBlockNum + offset + (sizeof(struct spaceBitmapDesc) << 3); do { overflow = 0; block_group = block >> (sb->s_blocksize_bits + 3); bit = block % (sb->s_blocksize << 3); /* * Check to see if we are freeing blocks across a group boundary. */ if (bit + count > (sb->s_blocksize << 3)) { overflow = bit + count - (sb->s_blocksize << 3); count -= overflow; } bitmap_nr = load_block_bitmap(sb, bitmap, block_group); if (bitmap_nr < 0) goto error_return; bh = bitmap->s_block_bitmap[bitmap_nr]; for (i = 0; i < count; i++) { if (udf_set_bit(bit + i, bh->b_data)) { udf_debug("bit %lu already set\n", bit + i); udf_debug("byte=%2x\n", ((__u8 *)bh->b_data)[(bit + i) >> 3]); } } udf_add_free_space(sb, sbi->s_partition, count); mark_buffer_dirty(bh); if (overflow) { block += count; count = overflow; } } while (overflow); error_return: mutex_unlock(&sbi->s_alloc_mutex); } static int udf_bitmap_prealloc_blocks(struct super_block *sb, struct udf_bitmap *bitmap, uint16_t partition, uint32_t first_block, uint32_t block_count) { struct udf_sb_info *sbi = UDF_SB(sb); int alloc_count = 0; int bit, block, block_group; int bitmap_nr; struct buffer_head *bh; __u32 part_len; mutex_lock(&sbi->s_alloc_mutex); part_len = sbi->s_partmaps[partition].s_partition_len; if (first_block >= part_len) goto out; if (first_block + block_count > part_len) block_count = part_len - first_block; do { block = first_block + (sizeof(struct spaceBitmapDesc) << 3); block_group = block >> (sb->s_blocksize_bits + 3); bitmap_nr = load_block_bitmap(sb, bitmap, block_group); if (bitmap_nr < 0) goto out; bh = bitmap->s_block_bitmap[bitmap_nr]; bit = block % (sb->s_blocksize << 3); while (bit < (sb->s_blocksize << 3) && block_count > 0) { if (!udf_clear_bit(bit, bh->b_data)) goto out; block_count--; alloc_count++; bit++; block++; } mark_buffer_dirty(bh); } while (block_count > 0); out: udf_add_free_space(sb, partition, -alloc_count); mutex_unlock(&sbi->s_alloc_mutex); return alloc_count; } static udf_pblk_t udf_bitmap_new_block(struct super_block *sb, struct udf_bitmap *bitmap, uint16_t partition, uint32_t goal, int *err) { struct udf_sb_info *sbi = UDF_SB(sb); int newbit, bit = 0; udf_pblk_t block; int block_group, group_start; int end_goal, nr_groups, bitmap_nr, i; struct buffer_head *bh = NULL; char *ptr; udf_pblk_t newblock = 0; *err = -ENOSPC; mutex_lock(&sbi->s_alloc_mutex); repeat: if (goal >= sbi->s_partmaps[partition].s_partition_len) goal = 0; nr_groups = bitmap->s_nr_groups; block = goal + (sizeof(struct spaceBitmapDesc) << 3); block_group = block >> (sb->s_blocksize_bits + 3); group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc); bitmap_nr = load_block_bitmap(sb, bitmap, block_group); if (bitmap_nr < 0) goto error_return; bh = bitmap->s_block_bitmap[bitmap_nr]; ptr = memscan((char *)bh->b_data + group_start, 0xFF, sb->s_blocksize - group_start); if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) { bit = block % (sb->s_blocksize << 3); if (udf_test_bit(bit, bh->b_data)) goto got_block; end_goal = (bit + 63) & ~63; bit = udf_find_next_one_bit(bh->b_data, end_goal, bit); if (bit < end_goal) goto got_block; ptr = memscan((char *)bh->b_data + (bit >> 3), 0xFF, sb->s_blocksize - ((bit + 7) >> 3)); newbit = (ptr - ((char *)bh->b_data)) << 3; if (newbit < sb->s_blocksize << 3) { bit = newbit; goto search_back; } newbit = udf_find_next_one_bit(bh->b_data, sb->s_blocksize << 3, bit); if (newbit < sb->s_blocksize << 3) { bit = newbit; goto got_block; } } for (i = 0; i < (nr_groups * 2); i++) { block_group++; if (block_group >= nr_groups) block_group = 0; group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc); bitmap_nr = load_block_bitmap(sb, bitmap, block_group); if (bitmap_nr < 0) goto error_return; bh = bitmap->s_block_bitmap[bitmap_nr]; if (i < nr_groups) { ptr = memscan((char *)bh->b_data + group_start, 0xFF, sb->s_blocksize - group_start); if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) { bit = (ptr - ((char *)bh->b_data)) << 3; break; } } else { bit = udf_find_next_one_bit(bh->b_data, sb->s_blocksize << 3, group_start << 3); if (bit < sb->s_blocksize << 3) break; } } if (i >= (nr_groups * 2)) { mutex_unlock(&sbi->s_alloc_mutex); return newblock; } if (bit < sb->s_blocksize << 3) goto search_back; else bit = udf_find_next_one_bit(bh->b_data, sb->s_blocksize << 3, group_start << 3); if (bit >= sb->s_blocksize << 3) { mutex_unlock(&sbi->s_alloc_mutex); return 0; } search_back: i = 0; while (i < 7 && bit > (group_start << 3) && udf_test_bit(bit - 1, bh->b_data)) { ++i; --bit; } got_block: newblock = bit + (block_group << (sb->s_blocksize_bits + 3)) - (sizeof(struct spaceBitmapDesc) << 3); if (!udf_clear_bit(bit, bh->b_data)) { udf_debug("bit already cleared for block %d\n", bit); goto repeat; } mark_buffer_dirty(bh); udf_add_free_space(sb, partition, -1); mutex_unlock(&sbi->s_alloc_mutex); *err = 0; return newblock; error_return: *err = -EIO; mutex_unlock(&sbi->s_alloc_mutex); return 0; } static void udf_table_free_blocks(struct super_block *sb, struct inode *table, struct kernel_lb_addr *bloc, uint32_t offset, uint32_t count) { struct udf_sb_info *sbi = UDF_SB(sb); struct udf_part_map *partmap; uint32_t start, end; uint32_t elen; struct kernel_lb_addr eloc; struct extent_position oepos, epos; int8_t etype; struct udf_inode_info *iinfo; mutex_lock(&sbi->s_alloc_mutex); partmap = &sbi->s_partmaps[bloc->partitionReferenceNum]; if (bloc->logicalBlockNum + count < count || (bloc->logicalBlockNum + count) > partmap->s_partition_len) { udf_debug("%u < %d || %u + %u > %u\n", bloc->logicalBlockNum, 0, bloc->logicalBlockNum, count, partmap->s_partition_len); goto error_return; } iinfo = UDF_I(table); udf_add_free_space(sb, sbi->s_partition, count); start = bloc->logicalBlockNum + offset; end = bloc->logicalBlockNum + offset + count - 1; epos.offset = oepos.offset = sizeof(struct unallocSpaceEntry); elen = 0; epos.block = oepos.block = iinfo->i_location; epos.bh = oepos.bh = NULL; while (count && (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) { if (((eloc.logicalBlockNum + (elen >> sb->s_blocksize_bits)) == start)) { if ((0x3FFFFFFF - elen) < (count << sb->s_blocksize_bits)) { uint32_t tmp = ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits); count -= tmp; start += tmp; elen = (etype << 30) | (0x40000000 - sb->s_blocksize); } else { elen = (etype << 30) | (elen + (count << sb->s_blocksize_bits)); start += count; count = 0; } udf_write_aext(table, &oepos, &eloc, elen, 1); } else if (eloc.logicalBlockNum == (end + 1)) { if ((0x3FFFFFFF - elen) < (count << sb->s_blocksize_bits)) { uint32_t tmp = ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits); count -= tmp; end -= tmp; eloc.logicalBlockNum -= tmp; elen = (etype << 30) | (0x40000000 - sb->s_blocksize); } else { eloc.logicalBlockNum = start; elen = (etype << 30) | (elen + (count << sb->s_blocksize_bits)); end -= count; count = 0; } udf_write_aext(table, &oepos, &eloc, elen, 1); } if (epos.bh != oepos.bh) { oepos.block = epos.block; brelse(oepos.bh); get_bh(epos.bh); oepos.bh = epos.bh; oepos.offset = 0; } else { oepos.offset = epos.offset; } } if (count) { /* * NOTE: we CANNOT use udf_add_aext here, as it can try to * allocate a new block, and since we hold the super block * lock already very bad things would happen :) * * We copy the behavior of udf_add_aext, but instead of * trying to allocate a new block close to the existing one, * we just steal a block from the extent we are trying to add. * * It would be nice if the blocks were close together, but it * isn't required. */ int adsize; eloc.logicalBlockNum = start; elen = EXT_RECORDED_ALLOCATED | (count << sb->s_blocksize_bits); if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT) adsize = sizeof(struct short_ad); else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG) adsize = sizeof(struct long_ad); else { brelse(oepos.bh); brelse(epos.bh); goto error_return; } if (epos.offset + (2 * adsize) > sb->s_blocksize) { /* Steal a block from the extent being free'd */ udf_setup_indirect_aext(table, eloc.logicalBlockNum, &epos); eloc.logicalBlockNum++; elen -= sb->s_blocksize; } /* It's possible that stealing the block emptied the extent */ if (elen) __udf_add_aext(table, &epos, &eloc, elen, 1); } brelse(epos.bh); brelse(oepos.bh); error_return: mutex_unlock(&sbi->s_alloc_mutex); return; } static int udf_table_prealloc_blocks(struct super_block *sb, struct inode *table, uint16_t partition, uint32_t first_block, uint32_t block_count) { struct udf_sb_info *sbi = UDF_SB(sb); int alloc_count = 0; uint32_t elen, adsize; struct kernel_lb_addr eloc; struct extent_position epos; int8_t etype = -1; struct udf_inode_info *iinfo; if (first_block >= sbi->s_partmaps[partition].s_partition_len) return 0; iinfo = UDF_I(table); if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT) adsize = sizeof(struct short_ad); else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG) adsize = sizeof(struct long_ad); else return 0; mutex_lock(&sbi->s_alloc_mutex); epos.offset = sizeof(struct unallocSpaceEntry); epos.block = iinfo->i_location; epos.bh = NULL; eloc.logicalBlockNum = 0xFFFFFFFF; while (first_block != eloc.logicalBlockNum && (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) { udf_debug("eloc=%u, elen=%u, first_block=%u\n", eloc.logicalBlockNum, elen, first_block); ; /* empty loop body */ } if (first_block == eloc.logicalBlockNum) { epos.offset -= adsize; alloc_count = (elen >> sb->s_blocksize_bits); if (alloc_count > block_count) { alloc_count = block_count; eloc.logicalBlockNum += alloc_count; elen -= (alloc_count << sb->s_blocksize_bits); udf_write_aext(table, &epos, &eloc, (etype << 30) | elen, 1); } else udf_delete_aext(table, epos); } else { alloc_count = 0; } brelse(epos.bh); if (alloc_count) udf_add_free_space(sb, partition, -alloc_count); mutex_unlock(&sbi->s_alloc_mutex); return alloc_count; } static udf_pblk_t udf_table_new_block(struct super_block *sb, struct inode *table, uint16_t partition, uint32_t goal, int *err) { struct udf_sb_info *sbi = UDF_SB(sb); uint32_t spread = 0xFFFFFFFF, nspread = 0xFFFFFFFF; udf_pblk_t newblock = 0; uint32_t adsize; uint32_t elen, goal_elen = 0; struct kernel_lb_addr eloc, uninitialized_var(goal_eloc); struct extent_position epos, goal_epos; int8_t etype; struct udf_inode_info *iinfo = UDF_I(table); *err = -ENOSPC; if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT) adsize = sizeof(struct short_ad); else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG) adsize = sizeof(struct long_ad); else return newblock; mutex_lock(&sbi->s_alloc_mutex); if (goal >= sbi->s_partmaps[partition].s_partition_len) goal = 0; /* We search for the closest matching block to goal. If we find a exact hit, we stop. Otherwise we keep going till we run out of extents. We store the buffer_head, bloc, and extoffset of the current closest match and use that when we are done. */ epos.offset = sizeof(struct unallocSpaceEntry); epos.block = iinfo->i_location; epos.bh = goal_epos.bh = NULL; while (spread && (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) { if (goal >= eloc.logicalBlockNum) { if (goal < eloc.logicalBlockNum + (elen >> sb->s_blocksize_bits)) nspread = 0; else nspread = goal - eloc.logicalBlockNum - (elen >> sb->s_blocksize_bits); } else { nspread = eloc.logicalBlockNum - goal; } if (nspread < spread) { spread = nspread; if (goal_epos.bh != epos.bh) { brelse(goal_epos.bh); goal_epos.bh = epos.bh; get_bh(goal_epos.bh); } goal_epos.block = epos.block; goal_epos.offset = epos.offset - adsize; goal_eloc = eloc; goal_elen = (etype << 30) | elen; } } brelse(epos.bh); if (spread == 0xFFFFFFFF) { brelse(goal_epos.bh); mutex_unlock(&sbi->s_alloc_mutex); return 0; } /* Only allocate blocks from the beginning of the extent. That way, we only delete (empty) extents, never have to insert an extent because of splitting */ /* This works, but very poorly.... */ newblock = goal_eloc.logicalBlockNum; goal_eloc.logicalBlockNum++; goal_elen -= sb->s_blocksize; if (goal_elen) udf_write_aext(table, &goal_epos, &goal_eloc, goal_elen, 1); else udf_delete_aext(table, goal_epos); brelse(goal_epos.bh); udf_add_free_space(sb, partition, -1); mutex_unlock(&sbi->s_alloc_mutex); *err = 0; return newblock; } void udf_free_blocks(struct super_block *sb, struct inode *inode, struct kernel_lb_addr *bloc, uint32_t offset, uint32_t count) { uint16_t partition = bloc->partitionReferenceNum; struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition]; if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP) { udf_bitmap_free_blocks(sb, map->s_uspace.s_bitmap, bloc, offset, count); } else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE) { udf_table_free_blocks(sb, map->s_uspace.s_table, bloc, offset, count); } if (inode) { inode_sub_bytes(inode, ((sector_t)count) << sb->s_blocksize_bits); } } inline int udf_prealloc_blocks(struct super_block *sb, struct inode *inode, uint16_t partition, uint32_t first_block, uint32_t block_count) { struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition]; int allocated; if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP) allocated = udf_bitmap_prealloc_blocks(sb, map->s_uspace.s_bitmap, partition, first_block, block_count); else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE) allocated = udf_table_prealloc_blocks(sb, map->s_uspace.s_table, partition, first_block, block_count); else return 0; if (inode && allocated > 0) inode_add_bytes(inode, allocated << sb->s_blocksize_bits); return allocated; } inline udf_pblk_t udf_new_block(struct super_block *sb, struct inode *inode, uint16_t partition, uint32_t goal, int *err) { struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition]; udf_pblk_t block; if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP) block = udf_bitmap_new_block(sb, map->s_uspace.s_bitmap, partition, goal, err); else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE) block = udf_table_new_block(sb, map->s_uspace.s_table, partition, goal, err); else { *err = -EIO; return 0; } if (inode && block) inode_add_bytes(inode, sb->s_blocksize); return block; }