diff options
Diffstat (limited to 'fs/ext4/mballoc.c')
| -rw-r--r-- | fs/ext4/mballoc.c | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 730c1a72a959..92aa05ddef66 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -4700,6 +4700,130 @@ error_return: } /** + * ext4_add_groupblocks() -- Add given blocks to an existing group + * @handle: handle to this transaction + * @sb: super block + * @block: start physcial block to add to the block group + * @count: number of blocks to free + * + * This marks the blocks as free in the bitmap. We ask the + * mballoc to reload the buddy after this by setting group + * EXT4_GROUP_INFO_NEED_INIT_BIT flag + */ +void ext4_add_groupblocks(handle_t *handle, struct super_block *sb, + ext4_fsblk_t block, unsigned long count) +{ + struct buffer_head *bitmap_bh = NULL; + struct buffer_head *gd_bh; + ext4_group_t block_group; + ext4_grpblk_t bit; + unsigned int i; + struct ext4_group_desc *desc; + struct ext4_sb_info *sbi = EXT4_SB(sb); + int err = 0, ret, blk_free_count; + ext4_grpblk_t blocks_freed; + struct ext4_group_info *grp; + + ext4_debug("Adding block(s) %llu-%llu\n", block, block + count - 1); + + ext4_get_group_no_and_offset(sb, block, &block_group, &bit); + grp = ext4_get_group_info(sb, block_group); + /* + * Check to see if we are freeing blocks across a group + * boundary. + */ + if (bit + count > EXT4_BLOCKS_PER_GROUP(sb)) { + goto error_return; + } + bitmap_bh = ext4_read_block_bitmap(sb, block_group); + if (!bitmap_bh) + goto error_return; + desc = ext4_get_group_desc(sb, block_group, &gd_bh); + if (!desc) + goto error_return; + + if (in_range(ext4_block_bitmap(sb, desc), block, count) || + in_range(ext4_inode_bitmap(sb, desc), block, count) || + in_range(block, ext4_inode_table(sb, desc), sbi->s_itb_per_group) || + in_range(block + count - 1, ext4_inode_table(sb, desc), + sbi->s_itb_per_group)) { + ext4_error(sb, "Adding blocks in system zones - " + "Block = %llu, count = %lu", + block, count); + goto error_return; + } + + /* + * We are about to add blocks to the bitmap, + * so we need undo access. + */ + BUFFER_TRACE(bitmap_bh, "getting undo access"); + err = ext4_journal_get_undo_access(handle, bitmap_bh); + if (err) + goto error_return; + + /* + * We are about to modify some metadata. Call the journal APIs + * to unshare ->b_data if a currently-committing transaction is + * using it + */ + BUFFER_TRACE(gd_bh, "get_write_access"); + err = ext4_journal_get_write_access(handle, gd_bh); + if (err) + goto error_return; + /* + * make sure we don't allow a parallel init on other groups in the + * same buddy cache + */ + down_write(&grp->alloc_sem); + for (i = 0, blocks_freed = 0; i < count; i++) { + BUFFER_TRACE(bitmap_bh, "clear bit"); + if (!ext4_clear_bit_atomic(ext4_group_lock_ptr(sb, block_group), + bit + i, bitmap_bh->b_data)) { + ext4_error(sb, "bit already cleared for block %llu", + (ext4_fsblk_t)(block + i)); + BUFFER_TRACE(bitmap_bh, "bit already cleared"); + } else { + blocks_freed++; + } + } + ext4_lock_group(sb, block_group); + blk_free_count = blocks_freed + ext4_free_blks_count(sb, desc); + ext4_free_blks_set(sb, desc, blk_free_count); + desc->bg_checksum = ext4_group_desc_csum(sbi, block_group, desc); + ext4_unlock_group(sb, block_group); + percpu_counter_add(&sbi->s_freeblocks_counter, blocks_freed); + + if (sbi->s_log_groups_per_flex) { + ext4_group_t flex_group = ext4_flex_group(sbi, block_group); + atomic_add(blocks_freed, + &sbi->s_flex_groups[flex_group].free_blocks); + } + /* + * request to reload the buddy with the + * new bitmap information + */ + set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &(grp->bb_state)); + grp->bb_free += blocks_freed; + up_write(&grp->alloc_sem); + + /* We dirtied the bitmap block */ + BUFFER_TRACE(bitmap_bh, "dirtied bitmap block"); + err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh); + + /* And the group descriptor block */ + BUFFER_TRACE(gd_bh, "dirtied group descriptor block"); + ret = ext4_handle_dirty_metadata(handle, NULL, gd_bh); + if (!err) + err = ret; + +error_return: + brelse(bitmap_bh); + ext4_std_error(sb, err); + return; +} + +/** * ext4_trim_extent -- function to TRIM one single free extent in the group * @sb: super block for the file system * @start: starting block of the free extent in the alloc. group |