On 2018/11/27 下午3:15, Nikolay Borisov wrote:
>
>
> On 27.11.18 г. 4:33 ч., Qu Wenruo wrote:
>> Since btrfs-image is just restoring tree blocks without really check if
>> that tree block contents makes sense, for multi-device image, block
>> group items will keep that incorrect block group flags.
>>
>> For example, for a metadata RAID1 data RAID0 btrfs recovered to a single
>> disk, its chunk tree will look like:
>>
>> item 1 key (FIRST_CHUNK_TREE CHUNK_ITEM 22020096)
>> length 8388608 owner 2 stripe_len 65536 type SYSTEM
>> item 2 key (FIRST_CHUNK_TREE CHUNK_ITEM 30408704)
>> length 1073741824 owner 2 stripe_len 65536 type METADATA
>> item 3 key (FIRST_CHUNK_TREE CHUNK_ITEM 1104150528)
>> length 1073741824 owner 2 stripe_len 65536 type DATA
>>
>> All chunks have correct type (SINGLE).
>>
>> While its block group items will look like:
>>
>> item 1 key (22020096 BLOCK_GROUP_ITEM 8388608)
>> block group used 16384 chunk_objectid 256 flags SYSTEM|RAID1
>> item 3 key (30408704 BLOCK_GROUP_ITEM 1073741824)
>> block group used 114688 chunk_objectid 256 flags METADATA|RAID1
>> item 11 key (1104150528 BLOCK_GROUP_ITEM 1073741824)
>> block group used 1572864 chunk_objectid 256 flags DATA|RAID0
>>
>> All block group items still have the wrong profiles.
>>
>> And btrfs check (lowmem mode for better output) will report error for such
>> image:
>>
>> ERROR: chunk[22020096 30408704) related block group item flags mismatch,
>> wanted: 2, have: 18
>> ERROR: chunk[30408704 1104150528) related block group item flags mismatch,
>> wanted: 4, have: 20
>> ERROR: chunk[1104150528 2177892352) related block group item flags
>> mismatch, wanted: 1, have: 9
>>
>> This patch will do an extra repair for block group items to fix the
>> profile of them.
>>
>> Signed-off-by: Qu Wenruo <[email protected]>
>> ---
>> image/main.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++
>> 1 file changed, 47 insertions(+)
>>
>> diff --git a/image/main.c b/image/main.c
>> index 36b5c95ea146..9060f6b1b665 100644
>> --- a/image/main.c
>> +++ b/image/main.c
>> @@ -2164,6 +2164,52 @@ again:
>> return 0;
>> }
>>
>> +static void fixup_block_groups(struct btrfs_trans_handle *trans,
>> + struct btrfs_fs_info *fs_info)
>
> You are not even using the trans handle in this function, why pass it?
Bad habit again.
Will definitely do something with that.
Thanks,
Qu
>
>> +{
>> + struct btrfs_block_group_cache *bg;
>> + struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
>> + struct cache_extent *ce;
>> + struct map_lookup *map;
>> + u64 extra_flags;
>> +
>> + for (ce = search_cache_extent(&map_tree->cache_tree, 0); ce;
>> + ce = next_cache_extent(ce)) {
>> + map = container_of(ce, struct map_lookup, ce);
>> +
>> + bg = btrfs_lookup_block_group(fs_info, ce->start);
>> + if (!bg) {
>> + warning(
>> + "can't find block group %llu, result fs may not be mountable",
>> + ce->start);
>> + continue;
>> + }
>> + extra_flags = map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK;
>> +
>> + if (bg->flags == map->type)
>> + continue;
>> +
>> + /* Update the block group item and mark the bg dirty */
>> + bg->flags = map->type;
>> + btrfs_set_block_group_flags(&bg->item, bg->flags);
>> + set_extent_bits(&fs_info->block_group_cache, ce->start,
>> + ce->start + ce->size - 1, BLOCK_GROUP_DIRTY);
>> +
>> + /*
>> + * Chunk and bg flags can be different, changing bg flags
>> + * without update avail_data/meta_alloc_bits will lead to
>> + * ENOSPC.
>> + * So here we set avail_*_alloc_bits to match chunk types.
>> + */
>> + if (map->type & BTRFS_BLOCK_GROUP_DATA)
>> + fs_info->avail_data_alloc_bits = extra_flags;
>> + if (map->type & BTRFS_BLOCK_GROUP_METADATA)
>> + fs_info->avail_metadata_alloc_bits = extra_flags;
>> + if (map->type & BTRFS_BLOCK_GROUP_SYSTEM)
>> + fs_info->avail_system_alloc_bits = extra_flags;
>> + }
>> +}
>> +
>> static int fixup_chunks_and_devices(struct btrfs_fs_info *fs_info,
>> struct mdrestore_struct *mdres, off_t dev_size)
>> {
>> @@ -2180,6 +2226,7 @@ static int fixup_chunks_and_devices(struct
>> btrfs_fs_info *fs_info,
>> return PTR_ERR(trans);
>> }
>>
>> + fixup_block_groups(trans, fs_info);
>> ret = fixup_device_size(trans, fs_info, mdres, dev_size);
>> if (ret < 0)
>> goto error;
>>
