Commit e6c11f9a authored by David Sterba's avatar David Sterba
Browse files

btrfs: reuse existing variable in scrub_stripe, reduce stack usage 



The key variable occupies 17 bytes, the key_start is used once, we can
simply reuse existing 'key' for that purpose. As the key is not a simple
type, compiler doest not do it on itself.

Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 49a3c4d9

fs/btrfs/scrub.c

+9 −10
Original line number Diff line number Diff line
@@ -3070,7 +3070,6 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx, 
	int slot;

	u64 nstripes;

	struct extent_buffer *l;

	struct btrfs_key key;

	u64 physical;

	u64 logical;

	u64 logic_end;
@@ -3079,7 +3078,7 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx, 
	int mirror_num;

	struct reada_control *reada1;

	struct reada_control *reada2;

	struct btrfs_key key_start;

	struct btrfs_key key;

	struct btrfs_key key_end;

	u64 increment = map->stripe_len;

	u64 offset;
@@ -3158,21 +3157,21 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx, 
	scrub_blocked_if_needed(fs_info);



	/* FIXME it might be better to start readahead at commit root */

	key_start.objectid = logical;

	key_start.type = BTRFS_EXTENT_ITEM_KEY;

	key_start.offset = (u64)0;

	key.objectid = logical;

	key.type = BTRFS_EXTENT_ITEM_KEY;

	key.offset = (u64)0;

	key_end.objectid = logic_end;

	key_end.type = BTRFS_METADATA_ITEM_KEY;

	key_end.offset = (u64)-1;

	reada1 = btrfs_reada_add(root, &key_start, &key_end);

	reada1 = btrfs_reada_add(root, &key, &key_end);



	key_start.objectid = BTRFS_EXTENT_CSUM_OBJECTID;

	key_start.type = BTRFS_EXTENT_CSUM_KEY;

	key_start.offset = logical;

	key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;

	key.type = BTRFS_EXTENT_CSUM_KEY;

	key.offset = logical;

	key_end.objectid = BTRFS_EXTENT_CSUM_OBJECTID;

	key_end.type = BTRFS_EXTENT_CSUM_KEY;

	key_end.offset = logic_end;

	reada2 = btrfs_reada_add(csum_root, &key_start, &key_end);

	reada2 = btrfs_reada_add(csum_root, &key, &key_end);



	if (!IS_ERR(reada1))

		btrfs_reada_wait(reada1);

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