On 2017年12月20日 16:21, Su Yue wrote: > > > On 12/20/2017 01:41 PM, Qu Wenruo wrote: >> >> >> On 2017年12月20日 12:57, Su Yue wrote: >>> Introduce create_chunk_and_block_block_group() to allocate new chunk >>> and corresponding block group. >>> >>> The new function force_cow_in_new_chunk() first allocates new chunk >>> and records its start. >>> Then it modifies all metadata block groups cached and full. >>> Finally it marks the new block group uncached and unfree. >>> In the next CoW, extents states will be updated automatically by >>> cache_block_group(). >>> >>> Suggested-by: Qu Wenruo <[email protected]> >>> Signed-off-by: Su Yue <[email protected]> >>> --- >>> cmds-check.c | 80 >>> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ >>> 1 file changed, 80 insertions(+) >>> >>> diff --git a/cmds-check.c b/cmds-check.c >>> index d98d4bda7357..311c8a9f45e8 100644 >>> --- a/cmds-check.c >>> +++ b/cmds-check.c >>> @@ -10911,6 +10911,86 @@ out: >>> return ret; >>> } >>> +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, >>> + BTRFS_FIRST_CHUNK_TREE_OBJECTID, *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) >>> +{ >>> + 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); >> >> Why bother allocating a new chunk by yourself? >> >> Just mark all block groups full and that's all. >> >> Any later tree block allocation like btrfs_search_slot() with @cow = 1 >> will trigger chunk allocation automatically. >> > > Tried to let it happen but BUG_ON with -ENOSPC.
Then fix it.
It's not a normal behavior in this case.
Thanks,
Qu
> Do you mean do_chunk_alloc() in btrfs_reserve_extent() which is called
> while doing CoW?> In progs, allocation of new chunk during CoW depends
> @root->ref_cows.
> However, @root->ref_cows should be set only if @root is root of a fs
> trees.
>
> Thanks,
> Su
>
>> Thanks,
>> Qu
>>
>>> + if (!ret)
>>> + printf("Create new chunk %llu %llu\n", start, nbytes);
>>> + else
>>> + goto err;
>>> +
>>> + flags = BTRFS_BLOCK_GROUP_METADATA;
>>> + /* Mark all metadata block groups cached and full in free space*/
>>> + ret = modify_block_groups_cache(fs_info, flags, 1);
>>> + if (ret)
>>> + goto clear_bg_cache;
>>> +
>>> + 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_bg_cache;
>>> + }
>>> +
>>> + /* Clear block group cache just allocated */
>>> + ret = modify_block_group_cache(fs_info, bg, 0);
>>> + if (ret)
>>> + goto clear_bg_cache;
>>> +
>>> + return 0;
>>> +
>>> +clear_bg_cache:
>>> + modify_block_groups_cache(fs_info, flags, 0);
>>> +err:
>>> + return ret;
>>> +}
>>> +
>>> static int check_extent_refs(struct btrfs_root *root,
>>> struct cache_tree *extent_cache)
>>> {
>>>
>>
>
>
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