diff options
Diffstat (limited to 'fs/udf/balloc.c')
-rw-r--r-- | fs/udf/balloc.c | 735 |
1 files changed, 735 insertions, 0 deletions
diff --git a/fs/udf/balloc.c b/fs/udf/balloc.c new file mode 100644 index 000000000..fcda0fc97 --- /dev/null +++ b/fs/udf/balloc.c @@ -0,0 +1,735 @@ +/* + * 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, group_start; + int nr_groups, 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 { + nr_groups = udf_compute_nr_groups(sb, partition); + block = first_block + (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 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); + } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP) { + udf_bitmap_free_blocks(sb, map->s_fspace.s_bitmap, + bloc, offset, count); + } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE) { + udf_table_free_blocks(sb, map->s_fspace.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 if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP) + allocated = udf_bitmap_prealloc_blocks(sb, + map->s_fspace.s_bitmap, + partition, first_block, + block_count); + else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE) + allocated = udf_table_prealloc_blocks(sb, + map->s_fspace.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 if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP) + block = udf_bitmap_new_block(sb, + map->s_fspace.s_bitmap, + partition, goal, err); + else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE) + block = udf_table_new_block(sb, + map->s_fspace.s_table, + partition, goal, err); + else { + *err = -EIO; + return 0; + } + if (inode && block) + inode_add_bytes(inode, sb->s_blocksize); + return block; +} |