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btrfs-progs: image: Fix block group item flags when restoring multi-device image to single device

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Since btrfs-image is just restoring tree blocks without really checking
if that tree block contents makes sense, for multi-device image, block
group items will keep the 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 <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Qu Wenruo 2018-11-27 16:38:25 +08:00 committed by David Sterba
parent ca73162b48
commit 9a65b425bb
1 changed files with 46 additions and 0 deletions
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46
image/main.c
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@ -2164,6 +2164,51 @@ again:
return 0;
}
static void fixup_block_groups(struct btrfs_fs_info *fs_info)
{
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(
"cannot find block group %llu, filesystem 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 +2225,7 @@ static int fixup_chunks_and_devices(struct btrfs_fs_info *fs_info,
return PTR_ERR(trans);
}
fixup_block_groups(fs_info);
ret = fixup_device_size(trans, mdres, dev_size);
if (ret < 0)
goto error;