From 5ce5b3c0916ba3a2e34cf648b94044adc5ef9e76 Mon Sep 17 00:00:00 2001 From: Ilya Dryomov Date: Mon, 16 Jan 2012 22:04:47 +0200 Subject: Btrfs: usage filter Select chunks that are less than X percent full. Signed-off-by: Ilya Dryomov --- fs/btrfs/volumes.c | 36 ++++++++++++++++++++++++++++++++++++ fs/btrfs/volumes.h | 1 + 2 files changed, 37 insertions(+) (limited to 'fs/btrfs') diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 447bd422d86..b858242374d 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -2120,6 +2120,36 @@ static int chunk_profiles_filter(u64 chunk_profile, return 1; } +static u64 div_factor_fine(u64 num, int factor) +{ + if (factor <= 0) + return 0; + if (factor >= 100) + return num; + + num *= factor; + do_div(num, 100); + return num; +} + +static int chunk_usage_filter(struct btrfs_fs_info *fs_info, u64 chunk_offset, + struct btrfs_balance_args *bargs) +{ + struct btrfs_block_group_cache *cache; + u64 chunk_used, user_thresh; + int ret = 1; + + cache = btrfs_lookup_block_group(fs_info, chunk_offset); + chunk_used = btrfs_block_group_used(&cache->item); + + user_thresh = div_factor_fine(cache->key.offset, bargs->usage); + if (chunk_used < user_thresh) + ret = 0; + + btrfs_put_block_group(cache); + return ret; +} + static int should_balance_chunk(struct btrfs_root *root, struct extent_buffer *leaf, struct btrfs_chunk *chunk, u64 chunk_offset) @@ -2147,6 +2177,12 @@ static int should_balance_chunk(struct btrfs_root *root, return 0; } + /* usage filter */ + if ((bargs->flags & BTRFS_BALANCE_ARGS_USAGE) && + chunk_usage_filter(bctl->fs_info, chunk_offset, bargs)) { + return 0; + } + return 1; } diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index fb20d774044..eee77fcf812 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -200,6 +200,7 @@ struct map_lookup { * Balance filters */ #define BTRFS_BALANCE_ARGS_PROFILES (1ULL << 0) +#define BTRFS_BALANCE_ARGS_USAGE (1ULL << 1) struct btrfs_balance_args; struct btrfs_balance_control { -- cgit v1.2.3-70-g09d2