diff options
Diffstat (limited to 'fs/ocfs2/refcounttree.c')
| -rw-r--r-- | fs/ocfs2/refcounttree.c | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/fs/ocfs2/refcounttree.c b/fs/ocfs2/refcounttree.c index f7d19f4..e72dbdd 100644 --- a/fs/ocfs2/refcounttree.c +++ b/fs/ocfs2/refcounttree.c @@ -2192,3 +2192,215 @@ static int ocfs2_mark_extent_refcounted(struct inode *inode, out: return ret; } + +/* + * Given some contiguous physical clusters, calculate what we need + * for modifying their refcount. + */ +static int ocfs2_calc_refcount_meta_credits(struct super_block *sb, + struct ocfs2_caching_info *ci, + struct buffer_head *ref_root_bh, + u64 start_cpos, + u32 clusters, + int *meta_add, + int *credits) +{ + int ret = 0, index, ref_blocks = 0, recs_add = 0; + u64 cpos = start_cpos; + struct ocfs2_refcount_block *rb; + struct ocfs2_refcount_rec rec; + struct buffer_head *ref_leaf_bh = NULL, *prev_bh = NULL; + u32 len; + + mlog(0, "start_cpos %llu, clusters %u\n", + (unsigned long long)start_cpos, clusters); + while (clusters) { + ret = ocfs2_get_refcount_rec(ci, ref_root_bh, + cpos, clusters, &rec, + &index, &ref_leaf_bh); + if (ret) { + mlog_errno(ret); + goto out; + } + + if (ref_leaf_bh != prev_bh) { + /* + * Now we encounter a new leaf block, so calculate + * whether we need to extend the old leaf. + */ + if (prev_bh) { + rb = (struct ocfs2_refcount_block *) + prev_bh->b_data; + + if (le64_to_cpu(rb->rf_records.rl_used) + + recs_add > + le16_to_cpu(rb->rf_records.rl_count)) + ref_blocks++; + } + + recs_add = 0; + *credits += 1; + brelse(prev_bh); + prev_bh = ref_leaf_bh; + get_bh(prev_bh); + } + + rb = (struct ocfs2_refcount_block *)ref_leaf_bh->b_data; + + mlog(0, "recs_add %d,cpos %llu, clusters %u, rec->r_cpos %llu," + "rec->r_clusters %u, rec->r_refcount %u, index %d\n", + recs_add, (unsigned long long)cpos, clusters, + (unsigned long long)le64_to_cpu(rec.r_cpos), + le32_to_cpu(rec.r_clusters), + le32_to_cpu(rec.r_refcount), index); + + len = min((u64)cpos + clusters, le64_to_cpu(rec.r_cpos) + + le32_to_cpu(rec.r_clusters)) - cpos; + /* + * If the refcount rec already exist, cool. We just need + * to check whether there is a split. Otherwise we just need + * to increase the refcount. + * If we will insert one, increases recs_add. + * + * We record all the records which will be inserted to the + * same refcount block, so that we can tell exactly whether + * we need a new refcount block or not. + */ + if (rec.r_refcount) { + /* Check whether we need a split at the beginning. */ + if (cpos == start_cpos && + cpos != le64_to_cpu(rec.r_cpos)) + recs_add++; + + /* Check whether we need a split in the end. */ + if (cpos + clusters < le64_to_cpu(rec.r_cpos) + + le32_to_cpu(rec.r_clusters)) + recs_add++; + } else + recs_add++; + + brelse(ref_leaf_bh); + ref_leaf_bh = NULL; + clusters -= len; + cpos += len; + } + + if (prev_bh) { + rb = (struct ocfs2_refcount_block *)prev_bh->b_data; + + if (le64_to_cpu(rb->rf_records.rl_used) + recs_add > + le16_to_cpu(rb->rf_records.rl_count)) + ref_blocks++; + + *credits += 1; + } + + if (!ref_blocks) + goto out; + + mlog(0, "we need ref_blocks %d\n", ref_blocks); + *meta_add += ref_blocks; + *credits += ref_blocks; + + /* + * So we may need ref_blocks to insert into the tree. + * That also means we need to change the b-tree and add that number + * of records since we never merge them. + * We need one more block for expansion since the new created leaf + * block is also full and needs split. + */ + rb = (struct ocfs2_refcount_block *)ref_root_bh->b_data; + if (le32_to_cpu(rb->rf_flags) & OCFS2_REFCOUNT_TREE_FL) { + struct ocfs2_extent_tree et; + + ocfs2_init_refcount_extent_tree(&et, ci, ref_root_bh); + *meta_add += ocfs2_extend_meta_needed(et.et_root_el); + *credits += ocfs2_calc_extend_credits(sb, + et.et_root_el, + ref_blocks); + } else { + *credits += OCFS2_EXPAND_REFCOUNT_TREE_CREDITS; + *meta_add += 1; + } + +out: + brelse(ref_leaf_bh); + brelse(prev_bh); + return ret; +} + +/* + * For refcount tree, we will decrease some contiguous clusters + * refcount count, so just go through it to see how many blocks + * we gonna touch and whether we need to create new blocks. + * + * Normally the refcount blocks store these refcount should be + * continguous also, so that we can get the number easily. + * As for meta_ac, we will at most add split 2 refcount record and + * 2 more refcount block, so just check it in a rough way. + * + * Caller must hold refcount tree lock. + */ +int ocfs2_prepare_refcount_change_for_del(struct inode *inode, + struct buffer_head *di_bh, + u64 phys_blkno, + u32 clusters, + int *credits, + struct ocfs2_alloc_context **meta_ac) +{ + int ret, ref_blocks = 0; + struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data; + struct ocfs2_inode_info *oi = OCFS2_I(inode); + struct buffer_head *ref_root_bh = NULL; + struct ocfs2_refcount_tree *tree; + u64 start_cpos = ocfs2_blocks_to_clusters(inode->i_sb, phys_blkno); + + if (!ocfs2_refcount_tree(OCFS2_SB(inode->i_sb))) { + ocfs2_error(inode->i_sb, "Inode %lu want to use refcount " + "tree, but the feature bit is not set in the " + "super block.", inode->i_ino); + ret = -EROFS; + goto out; + } + + BUG_ON(!(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL)); + + ret = ocfs2_get_refcount_tree(OCFS2_SB(inode->i_sb), + le64_to_cpu(di->i_refcount_loc), &tree); + if (ret) { + mlog_errno(ret); + goto out; + } + + ret = ocfs2_read_refcount_block(&tree->rf_ci, + le64_to_cpu(di->i_refcount_loc), + &ref_root_bh); + if (ret) { + mlog_errno(ret); + goto out; + } + + ret = ocfs2_calc_refcount_meta_credits(inode->i_sb, + &tree->rf_ci, + ref_root_bh, + start_cpos, clusters, + &ref_blocks, credits); + if (ret) { + mlog_errno(ret); + goto out; + } + + mlog(0, "reserve new metadata %d, credits = %d\n", + ref_blocks, *credits); + + if (ref_blocks) { + ret = ocfs2_reserve_new_metadata_blocks(OCFS2_SB(inode->i_sb), + ref_blocks, meta_ac); + if (ret) + mlog_errno(ret); + } + +out: + brelse(ref_root_bh); + return ret; +} |
