Btrfs: usage filter
Select chunks that are less than X percent full.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 447bd42..b858242 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2120,6 +2120,36 @@
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 @@
return 0;
}
+ /* usage filter */
+ if ((bargs->flags & BTRFS_BALANCE_ARGS_USAGE) &&
+ chunk_usage_filter(bctl->fs_info, chunk_offset, bargs)) {
+ return 0;
+ }
+
return 1;
}