diff options
Diffstat (limited to 'check/mode-lowmem.c')
| -rw-r--r-- | check/mode-lowmem.c | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/check/mode-lowmem.c b/check/mode-lowmem.c index de96c12b..eb50c7e6 100644 --- a/check/mode-lowmem.c +++ b/check/mode-lowmem.c @@ -326,6 +326,171 @@ static int clear_block_groups_full(struct btrfs_fs_info *fs_info, u64 flags) return modify_block_groups_cache(fs_info, flags, 0); } +static int create_chunk_and_block_group(struct btrfs_fs_info *fs_info, + u64 flags, u64 *start, u64 *nbytes) +{ + struct btrfs_trans_handle *trans; + struct btrfs_root *root = fs_info->extent_root; + int ret; + + if ((flags & BTRFS_BLOCK_GROUP_TYPE_MASK) == 0) + return -EINVAL; + + trans = btrfs_start_transaction(root, 1); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + error("error starting transaction %s", strerror(-ret)); + return ret; + } + ret = btrfs_alloc_chunk(trans, fs_info, start, nbytes, flags); + if (ret) { + error("fail to allocate new chunk %s", strerror(-ret)); + goto out; + } + ret = btrfs_make_block_group(trans, fs_info, 0, flags, *start, + *nbytes); + if (ret) { + error("fail to make block group for chunk %llu %llu %s", + *start, *nbytes, strerror(-ret)); + goto out; + } +out: + btrfs_commit_transaction(trans, root); + return ret; +} + +static int force_cow_in_new_chunk(struct btrfs_fs_info *fs_info, + u64 *start_ret) +{ + struct btrfs_block_group_cache *bg; + u64 start; + u64 nbytes; + u64 alloc_profile; + u64 flags; + int ret; + + alloc_profile = (fs_info->avail_metadata_alloc_bits & + fs_info->metadata_alloc_profile); + flags = BTRFS_BLOCK_GROUP_METADATA | alloc_profile; + if (btrfs_fs_incompat(fs_info, MIXED_GROUPS)) + flags |= BTRFS_BLOCK_GROUP_DATA; + + ret = create_chunk_and_block_group(fs_info, flags, &start, &nbytes); + if (ret) + goto err; + printf("Created new chunk [%llu %llu]\n", start, nbytes); + + flags = BTRFS_BLOCK_GROUP_METADATA; + /* Mark all metadata block groups cached and full in free space*/ + ret = mark_block_groups_full(fs_info, flags); + if (ret) + goto clear_bgs_full; + + bg = btrfs_lookup_block_group(fs_info, start); + if (!bg) { + ret = -ENOENT; + error("fail to look up block group %llu %llu", start, nbytes); + goto clear_bgs_full; + } + + /* Clear block group cache just allocated */ + ret = modify_block_group_cache(fs_info, bg, 0); + if (ret) + goto clear_bgs_full; + if (start_ret) + *start_ret = start; + return 0; + +clear_bgs_full: + clear_block_groups_full(fs_info, flags); +err: + return ret; +} + +/* + * Returns 0 means not almost full. + * Returns >0 means almost full. + * Returns <0 means fatal error. + */ +static int is_chunk_almost_full(struct btrfs_fs_info *fs_info, u64 start) +{ + struct btrfs_path path; + struct btrfs_key key; + struct btrfs_root *root = fs_info->extent_root; + struct btrfs_block_group_item *bi; + struct btrfs_block_group_item bg_item; + struct extent_buffer *eb; + u64 used; + u64 total; + u64 min_free; + int ret; + int slot; + + key.objectid = start; + key.type = BTRFS_BLOCK_GROUP_ITEM_KEY; + key.offset = (u64)-1; + + btrfs_init_path(&path); + ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0); + if (!ret) + ret = -EIO; + if (ret < 0) + goto out; + ret = btrfs_previous_item(root, &path, start, + BTRFS_BLOCK_GROUP_ITEM_KEY); + if (ret) { + error("failed to find block group %llu", start); + ret = -ENOENT; + goto out; + } + + eb = path.nodes[0]; + slot = path.slots[0]; + btrfs_item_key_to_cpu(eb, &key, slot); + if (key.objectid != start) { + ret = -ENOENT; + goto out; + } + + total = key.offset; + bi = btrfs_item_ptr(eb, slot, struct btrfs_block_group_item); + read_extent_buffer(eb, &bg_item, (unsigned long)bi, sizeof(bg_item)); + used = btrfs_block_group_used(&bg_item); + + /* + * if the free space in the chunk is less than %10 of total, + * or not not enough for CoW once, we think the chunk is almost full. + */ + min_free = max_t(u64, (BTRFS_MAX_LEVEL + 1) * fs_info->nodesize, + div_factor(total, 1)); + + if ((total - used) > min_free) + ret = 0; + else + ret = 1; +out: + btrfs_release_path(&path); + return ret; +} + +/* + * Returns <0 for error. + * Returns 0 for success. + */ +static int try_to_force_cow_in_new_chunk(struct btrfs_fs_info *fs_info, + u64 old_start, u64 *new_start) +{ + int ret; + + if (old_start) { + ret = is_chunk_almost_full(fs_info, old_start); + if (ret <= 0) + return ret; + } + ret = force_cow_in_new_chunk(fs_info, new_start); + return ret; +} + /* * This function only handles BACKREF_MISSING, * If corresponding extent item exists, increase the ref, else insert an extent |