On 21.11.18 г. 21:03 ч., Josef Bacik wrote:
> We've done this forever because of the voodoo around knowing how much
> space we have. However we have better ways of doing this now, and on
> normal file systems we'll easily have a global reserve of 512MiB, and
> since metadata chunks are usually 1GiB that means we'll allocate
> metadata chunks more readily. Instead use the actual used amount when
> determining if we need to allocate a chunk or not.
This explanation could use more concrete wording currently it's way too
"hand wavy"/vague.
>
> Signed-off-by: Josef Bacik <josef@xxxxxxxxxxxxxx>
> ---
> fs/btrfs/extent-tree.c | 9 ---------
> 1 file changed, 9 deletions(-)
>
> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
> index 7a30fbc05e5e..a91b3183dcae 100644
> --- a/fs/btrfs/extent-tree.c
> +++ b/fs/btrfs/extent-tree.c
> @@ -4388,21 +4388,12 @@ static inline u64 calc_global_rsv_need_space(struct btrfs_block_rsv *global)
> static int should_alloc_chunk(struct btrfs_fs_info *fs_info,
> struct btrfs_space_info *sinfo, int force)
> {
> - struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
> u64 bytes_used = btrfs_space_info_used(sinfo, false);
> u64 thresh;
>
> if (force == CHUNK_ALLOC_FORCE)
> return 1;
>
> - /*
> - * We need to take into account the global rsv because for all intents
> - * and purposes it's used space. Don't worry about locking the
> - * global_rsv, it doesn't change except when the transaction commits.
> - */
> - if (sinfo->flags & BTRFS_BLOCK_GROUP_METADATA)
> - bytes_used += calc_global_rsv_need_space(global_rsv);
> -
> /*
> * in limited mode, we want to have some free space up to
> * about 1% of the FS size.
>
