On Tue, Sep 11, 2018 at 01:57:45PM -0400, Josef Bacik wrote:
> If we use up our block group before allocating a new one we'll easily
> get a max_extent_size that's set really really low, which will result in
> a lot of fragmentation. We need to make sure we're resetting the
> max_extent_size when we add a new chunk or add new space.
>
> Signed-off-by: Josef Bacik
> ---
> fs/btrfs/extent-tree.c | 7 +++
> 1 file changed, 7 insertions(+)
>
> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
> index 13441a293c73..44d59bee6e5e 100644
> --- a/fs/btrfs/extent-tree.c
> +++ b/fs/btrfs/extent-tree.c
> @@ -4573,6 +4573,7 @@ static int do_chunk_alloc(struct btrfs_trans_handle
> *trans, u64 flags,
> goto out;
> } else {
> ret = 1;
> + space_info->max_extent_size = 0;
> }
>
> space_info->force_alloc = CHUNK_ALLOC_NO_FORCE;
> @@ -8084,11 +8085,17 @@ static int __btrfs_free_reserved_extent(struct
> btrfs_fs_info *fs_info,
> if (pin)
> pin_down_extent(fs_info, cache, start, len, 1);
> else {
> + struct btrfs_space_info *space_info = cache->space_info;
> +
> if (btrfs_test_opt(fs_info, DISCARD))
> ret = btrfs_discard_extent(fs_info, start, len, NULL,
> BTRFS_CLEAR_OP_DISCARD);
> btrfs_add_free_space(cache, start, len);
> btrfs_free_reserved_bytes(cache, len, delalloc);
> +
> + spin_lock(_info->lock);
> + space_info->max_extent_size = 0;
> + spin_unlock(_info->lock);
> trace_btrfs_reserved_extent_free(fs_info, start, len);
> }
Do we need to do the same for btrfs_free_tree_block()? If so, maybe it
can go in btrfs_free_reserved_bytes() instead?