diff options
| -rw-r--r-- | fs/ext4/balloc.c | 131 | ||||
| -rw-r--r-- | fs/ext4/ext4.h | 13 |
2 files changed, 103 insertions, 41 deletions
diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c index 735d9fcc72e6..1c6d777b35a2 100644 --- a/fs/ext4/balloc.c +++ b/fs/ext4/balloc.c @@ -23,9 +23,6 @@ #include <trace/events/ext4.h> -static unsigned int num_base_meta_blocks(struct super_block *sb, - ext4_group_t block_group); - /* * balloc.c contains the blocks allocation and deallocation routines */ @@ -58,37 +55,87 @@ static int ext4_block_in_group(struct super_block *sb, ext4_fsblk_t block, return 0; } -static int ext4_group_used_meta_blocks(struct super_block *sb, - ext4_group_t block_group, - struct ext4_group_desc *gdp) +/* Return the number of clusters used for file system metadata; this + * represents the overhead needed by the file system. + */ +unsigned ext4_num_overhead_clusters(struct super_block *sb, + ext4_group_t block_group, + struct ext4_group_desc *gdp) { - ext4_fsblk_t tmp; + unsigned num_clusters; + int block_cluster = -1, inode_cluster = -1, itbl_cluster = -1, i, c; + ext4_fsblk_t start = ext4_group_first_block_no(sb, block_group); + ext4_fsblk_t itbl_blk; struct ext4_sb_info *sbi = EXT4_SB(sb); - /* block bitmap, inode bitmap, and inode table blocks */ - int used_blocks = sbi->s_itb_per_group + 2; - if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG)) { - if (!ext4_block_in_group(sb, ext4_block_bitmap(sb, gdp), - block_group)) - used_blocks--; - - if (!ext4_block_in_group(sb, ext4_inode_bitmap(sb, gdp), - block_group)) - used_blocks--; - - tmp = ext4_inode_table(sb, gdp); - for (; tmp < ext4_inode_table(sb, gdp) + - sbi->s_itb_per_group; tmp++) { - if (!ext4_block_in_group(sb, tmp, block_group)) - used_blocks -= 1; + /* This is the number of clusters used by the superblock, + * block group descriptors, and reserved block group + * descriptor blocks */ + num_clusters = ext4_num_base_meta_clusters(sb, block_group); + + /* + * For the allocation bitmaps and inode table, we first need + * to check to see if the block is in the block group. If it + * is, then check to see if the cluster is already accounted + * for in the clusters used for the base metadata cluster, or + * if we can increment the base metadata cluster to include + * that block. Otherwise, we will have to track the cluster + * used for the allocation bitmap or inode table explicitly. + * Normally all of these blocks are contiguous, so the special + * case handling shouldn't be necessary except for *very* + * unusual file system layouts. + */ + if (ext4_block_in_group(sb, ext4_block_bitmap(sb, gdp), block_group)) { + block_cluster = EXT4_B2C(sbi, (start - + ext4_block_bitmap(sb, gdp))); + if (block_cluster < num_clusters) + block_cluster = -1; + else if (block_cluster == num_clusters) { + num_clusters++; + block_cluster = -1; + } + } + + if (ext4_block_in_group(sb, ext4_inode_bitmap(sb, gdp), block_group)) { + inode_cluster = EXT4_B2C(sbi, + start - ext4_inode_bitmap(sb, gdp)); + if (inode_cluster < num_clusters) + inode_cluster = -1; + else if (inode_cluster == num_clusters) { + num_clusters++; + inode_cluster = -1; + } + } + + itbl_blk = ext4_inode_table(sb, gdp); + for (i = 0; i < sbi->s_itb_per_group; i++) { + if (ext4_block_in_group(sb, itbl_blk + i, block_group)) { + c = EXT4_B2C(sbi, start - itbl_blk + i); + if ((c < num_clusters) || (c == inode_cluster) || + (c == block_cluster) || (c == itbl_cluster)) + continue; + if (c == num_clusters) { + num_clusters++; + continue; + } + num_clusters++; + itbl_cluster = c; } } - return used_blocks; + + if (block_cluster != -1) + num_clusters++; + if (inode_cluster != -1) + num_clusters++; + + return num_clusters; } -static unsigned int num_blocks_in_group(struct super_block *sb, - ext4_group_t block_group) +static unsigned int num_clusters_in_group(struct super_block *sb, + ext4_group_t block_group) { + unsigned int blocks; + if (block_group == ext4_get_groups_count(sb) - 1) { /* * Even though mke2fs always initializes the first and @@ -96,10 +143,11 @@ static unsigned int num_blocks_in_group(struct super_block *sb, * we need to make sure we calculate the right free * blocks. */ - return ext4_blocks_count(EXT4_SB(sb)->s_es) - + blocks = ext4_blocks_count(EXT4_SB(sb)->s_es) - ext4_group_first_block_no(sb, block_group); } else - return EXT4_BLOCKS_PER_GROUP(sb); + blocks = EXT4_BLOCKS_PER_GROUP(sb); + return EXT4_NUM_B2C(EXT4_SB(sb), blocks); } /* Initializes an uninitialized block bitmap */ @@ -107,7 +155,7 @@ void ext4_init_block_bitmap(struct super_block *sb, struct buffer_head *bh, ext4_group_t block_group, struct ext4_group_desc *gdp) { - unsigned int bit, bit_max = num_base_meta_blocks(sb, block_group); + unsigned int bit, bit_max; struct ext4_sb_info *sbi = EXT4_SB(sb); ext4_fsblk_t start, tmp; int flex_bg = 0; @@ -126,6 +174,7 @@ void ext4_init_block_bitmap(struct super_block *sb, struct buffer_head *bh, } memset(bh->b_data, 0, sb->s_blocksize); + bit_max = ext4_num_base_meta_clusters(sb, block_group); for (bit = 0; bit < bit_max; bit++) ext4_set_bit(bit, bh->b_data); @@ -137,24 +186,25 @@ void ext4_init_block_bitmap(struct super_block *sb, struct buffer_head *bh, /* Set bits for block and inode bitmaps, and inode table */ tmp = ext4_block_bitmap(sb, gdp); if (!flex_bg || ext4_block_in_group(sb, tmp, block_group)) - ext4_set_bit(tmp - start, bh->b_data); + ext4_set_bit(EXT4_B2C(sbi, tmp - start), bh->b_data); tmp = ext4_inode_bitmap(sb, gdp); if (!flex_bg || ext4_block_in_group(sb, tmp, block_group)) - ext4_set_bit(tmp - start, bh->b_data); + ext4_set_bit(EXT4_B2C(sbi, tmp - start), bh->b_data); tmp = ext4_inode_table(sb, gdp); for (; tmp < ext4_inode_table(sb, gdp) + sbi->s_itb_per_group; tmp++) { if (!flex_bg || ext4_block_in_group(sb, tmp, block_group)) - ext4_set_bit(tmp - start, bh->b_data); + ext4_set_bit(EXT4_B2C(sbi, tmp - start), bh->b_data); } + /* * Also if the number of blocks within the group is less than * the blocksize * 8 ( which is the size of bitmap ), set rest * of the block bitmap to 1 */ - ext4_mark_bitmap_end(num_blocks_in_group(sb, block_group), + ext4_mark_bitmap_end(num_clusters_in_group(sb, block_group), sb->s_blocksize * 8, bh->b_data); } @@ -165,9 +215,8 @@ unsigned ext4_free_blocks_after_init(struct super_block *sb, ext4_group_t block_group, struct ext4_group_desc *gdp) { - return num_blocks_in_group(sb, block_group) - - num_base_meta_blocks(sb, block_group) - - ext4_group_used_meta_blocks(sb, block_group, gdp); + return num_clusters_in_group(sb, block_group) - + ext4_num_overhead_clusters(sb, block_group, gdp); } /* @@ -611,14 +660,14 @@ unsigned long ext4_bg_num_gdb(struct super_block *sb, ext4_group_t group) } /* - * This function returns the number of file system metadata blocks at + * This function returns the number of file system metadata clusters at * the beginning of a block group, including the reserved gdt blocks. */ -static unsigned int num_base_meta_blocks(struct super_block *sb, - ext4_group_t block_group) +unsigned ext4_num_base_meta_clusters(struct super_block *sb, + ext4_group_t block_group) { struct ext4_sb_info *sbi = EXT4_SB(sb); - int num; + unsigned num; /* Check for superblock and gdt backups in this group */ num = ext4_bg_has_super(sb, block_group); @@ -633,7 +682,7 @@ static unsigned int num_base_meta_blocks(struct super_block *sb, } else { /* For META_BG_BLOCK_GROUPS */ num += ext4_bg_num_gdb(sb, block_group); } - return num; + return EXT4_NUM_B2C(sbi, num); } /** * ext4_inode_to_goal_block - return a hint for block allocation diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index b0b7b67e439d..803cfa42e1e8 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -261,6 +261,14 @@ struct ext4_io_submit { #endif #define EXT4_BLOCK_ALIGN(size, blkbits) ALIGN((size), (1 << (blkbits))) +/* Translate a block number to a cluster number */ +#define EXT4_B2C(sbi, blk) ((blk) >> (sbi)->s_cluster_bits) +/* Translate a cluster number to a block number */ +#define EXT4_C2B(sbi, cluster) ((cluster) << (sbi)->s_cluster_bits) +/* Translate # of blks to # of clusters */ +#define EXT4_NUM_B2C(sbi, blks) (((blks) + (sbi)->s_cluster_ratio - 1) >> \ + (sbi)->s_cluster_bits) + /* * Structure of a blocks group descriptor */ @@ -1770,6 +1778,11 @@ extern void ext4_init_block_bitmap(struct super_block *sb, extern unsigned ext4_free_blocks_after_init(struct super_block *sb, ext4_group_t block_group, struct ext4_group_desc *gdp); +extern unsigned ext4_num_base_meta_clusters(struct super_block *sb, + ext4_group_t block_group); +extern unsigned ext4_num_overhead_clusters(struct super_block *sb, + ext4_group_t block_group, + struct ext4_group_desc *gdp); ext4_fsblk_t ext4_inode_to_goal_block(struct inode *); /* dir.c */ |
