From 96f9b0f2fa01c96e90abd4e981208a341a5da66e Mon Sep 17 00:00:00 2001 From: Nikolay Borisov Date: Fri, 3 Apr 2020 16:40:35 +0300 Subject: [PATCH] btrfs: simplify checks when adding excluded ranges Adresses held in 'logical' array are always guaranteed to fall within the boundaries of the block group. That is, 'start' can never be smaller than cache->start. This invariant follows from the way the address are calculated in btrfs_rmap_block: stripe_nr = physical - map->stripes[i].physical; stripe_nr = div64_u64(stripe_nr, map->stripe_len); bytenr = chunk_start + stripe_nr * io_stripe_size; I.e it's always some IO stripe within the given chunk. Exploit this invariant to simplify the body of the loop by removing the unnecessary 'if' since its 'else' part is the one always executed. Signed-off-by: Nikolay Borisov Signed-off-by: David Sterba --- fs/btrfs/block-group.c | 21 ++++----------------- 1 file changed, 4 insertions(+), 17 deletions(-) diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c index 956ae6283d33..e29e9629b246 100644 --- a/fs/btrfs/block-group.c +++ b/fs/btrfs/block-group.c @@ -1741,25 +1741,12 @@ static int exclude_super_stripes(struct btrfs_block_group *cache) return ret; while (nr--) { - u64 start, len; - - if (logical[nr] > cache->start + cache->length) - continue; - - if (logical[nr] + stripe_len <= cache->start) - continue; - - start = logical[nr]; - if (start < cache->start) { - start = cache->start; - len = (logical[nr] + stripe_len) - start; - } else { - len = min_t(u64, stripe_len, - cache->start + cache->length - start); - } + u64 len = min_t(u64, stripe_len, + cache->start + cache->length - logical[nr]); cache->bytes_super += len; - ret = btrfs_add_excluded_extent(fs_info, start, len); + ret = btrfs_add_excluded_extent(fs_info, logical[nr], + len); if (ret) { kfree(logical); return ret;