From e6c11f9a462e9ef4876d5e1539a6c06eded4c793 Mon Sep 17 00:00:00 2001 From: David Sterba Date: Thu, 24 Mar 2016 18:00:53 +0100 Subject: [PATCH] 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: David Sterba --- fs/btrfs/scrub.c | 19 +++++++++---------- 1 file changed, 9 insertions(+), 10 deletions(-) diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c index 4678f03e878e..2ff2876656ba 100644 --- a/fs/btrfs/scrub.c +++ b/fs/btrfs/scrub.c @@ -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); -- 2.11.0