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btrfs-progs: mkfs: add the block group item in make_btrfs()

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Currently we build a bare-bones file system in make_btrfs(), and then we
load it up and fill in the rest of the file system after the fact.  One
thing we omit in make_btrfs() is the block group item for the temporary
system chunk we allocate, because we just add it after we've opened the
file system.

However I want to be able to generate the free space tree at
make_btrfs() time, because extent tree v2 will not have an extent tree
that has every block allocated in the system.  In order to do this I
need to make sure that the free space tree entries are added on block
group creation, which is annoying if we have to add this chunk after
I've created a free space tree.

So make future work simpler by simply adding our block group item at
make_btrfs() time, this way I can do the right things with the free
space tree in the generic make block group code without needing a
special case for our temporary system chunk.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Josef Bacik 2021-08-23 16:14:52 -04:00 committed by David Sterba
parent 3d870a491f
commit abc2b30443
2 changed files with 27 additions and 9 deletions
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25
mkfs/common.c
View file

@ -188,6 +188,7 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
u64 num_bytes;
u64 system_group_offset = BTRFS_BLOCK_RESERVED_1M_FOR_SUPER;
u64 system_group_size = BTRFS_MKFS_SYSTEM_GROUP_SIZE;
bool add_block_group = true;
if ((cfg->features & BTRFS_FEATURE_INCOMPAT_ZONED)) {
system_group_offset = cfg->zone_size * BTRFS_NR_SB_LOG_ZONES;
@ -276,6 +277,30 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
for (i = 0; i < blocks_nr; i++) {
blk = blocks[i];
/* Add the block group item for our temporary chunk. */
if (cfg->blocks[blk] > system_group_offset && add_block_group) {
struct btrfs_block_group_item *bg_item;
add_block_group = false;
itemoff -= sizeof(*bg_item);
btrfs_set_disk_key_objectid(&disk_key, system_group_offset);
btrfs_set_disk_key_offset(&disk_key, system_group_size);
btrfs_set_disk_key_type(&disk_key, BTRFS_BLOCK_GROUP_ITEM_KEY);
btrfs_set_item_key(buf, &disk_key, nritems);
btrfs_set_item_offset(buf, btrfs_item_nr(nritems), itemoff);
btrfs_set_item_size(buf, btrfs_item_nr(nritems), sizeof(*bg_item));
bg_item = btrfs_item_ptr(buf, nritems,
struct btrfs_block_group_item);
btrfs_set_block_group_used(buf, bg_item, total_used);
btrfs_set_block_group_flags(buf, bg_item,
BTRFS_BLOCK_GROUP_SYSTEM);
btrfs_set_block_group_chunk_objectid(buf, bg_item,
BTRFS_FIRST_CHUNK_TREE_OBJECTID);
nritems++;
}
item_size = sizeof(struct btrfs_extent_item);
if (!skinny_metadata)
item_size += sizeof(struct btrfs_tree_block_info);

11
mkfs/main.c
View file

@ -67,16 +67,13 @@ static int create_metadata_block_groups(struct btrfs_root *root, int mixed,
struct btrfs_trans_handle *trans;
struct btrfs_space_info *sinfo;
u64 flags = BTRFS_BLOCK_GROUP_METADATA;
u64 bytes_used;
u64 chunk_start = 0;
u64 chunk_size = 0;
u64 system_group_offset = BTRFS_BLOCK_RESERVED_1M_FOR_SUPER;
u64 system_group_size = BTRFS_MKFS_SYSTEM_GROUP_SIZE;
int ret;
if (btrfs_is_zoned(fs_info)) {
/* Two zones are reserved for superblock */
system_group_offset = fs_info->zone_size * BTRFS_NR_SB_LOG_ZONES;
system_group_size = fs_info->zone_size;
}
@ -90,16 +87,12 @@ static int create_metadata_block_groups(struct btrfs_root *root, int mixed,
trans = btrfs_start_transaction(root, 1);
BUG_ON(IS_ERR(trans));
bytes_used = btrfs_super_bytes_used(fs_info->super_copy);
root->fs_info->system_allocs = 1;
/*
* First temporary system chunk must match the chunk layout
* created in make_btrfs().
* We already created the block group item for our temporary system
* chunk in make_btrfs(), so account for the size here.
*/
ret = btrfs_make_block_group(trans, fs_info, bytes_used,
BTRFS_BLOCK_GROUP_SYSTEM,
system_group_offset, system_group_size);
allocation->system += system_group_size;
if (ret)
return ret;