Commit 50475cd5 authored by Naohiro Aota's avatar Naohiro Aota Committed by David Sterba
Browse files

btrfs: add extent allocator hook to decide to allocate chunk or not 



Introduce a new hook for an extent allocator policy. With the new
hook, a policy can decide to allocate a new block group or not. If
not, it will return -ENOSPC, so btrfs_reserve_extent() will cut the
allocation size in half and retry the allocation if min_alloc_size is
large enough.

The hook has a place holder and will be replaced with the real
implementation in the next patch.

CC: stable@vger.kernel.org # 5.16
Signed-off-by: default avatarNaohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 1ada69f6

fs/btrfs/extent-tree.c

+17 −0
Original line number Diff line number Diff line
@@ -3974,6 +3974,19 @@ static void found_extent(struct find_free_extent_ctl *ffe_ctl, 
	}

}



static bool can_allocate_chunk(struct btrfs_fs_info *fs_info,

			       struct find_free_extent_ctl *ffe_ctl)

{

	switch (ffe_ctl->policy) {

	case BTRFS_EXTENT_ALLOC_CLUSTERED:

		return true;

	case BTRFS_EXTENT_ALLOC_ZONED:

		return true;

	default:

		BUG();

	}

}



static int chunk_allocation_failed(struct find_free_extent_ctl *ffe_ctl)

{

	switch (ffe_ctl->policy) {
@@ -4061,6 +4074,10 @@ static int find_free_extent_update_loop(struct btrfs_fs_info *fs_info, 
			struct btrfs_trans_handle *trans;

			int exist = 0;



			/*Check if allocation policy allows to create a new chunk */

			if (!can_allocate_chunk(fs_info, ffe_ctl))

				return -ENOSPC;



			trans = current->journal_info;

			if (trans)

				exist = 1;