Btrfs: increase the global block reserve estimates

When doing IO with large amounts of data fragmentation, the global block
reserve calulations are too low.  This increases them to avoid
ENOSPC crashes.

Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index dc083f55bcfd6d59b1dfdabe7d854d53093ee037..079e5a1c343c53652b38460185cac442d0dd9887 100644 (file)
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -4108,7 +4108,7 @@ static u64 calc_global_metadata_size(struct btrfs_fs_info *fs_info)
        num_bytes += div64_u64(data_used + meta_used, 50);
 
        if (num_bytes * 3 > meta_used)
-               num_bytes = div64_u64(meta_used, 3);
+               num_bytes = div64_u64(meta_used, 3) * 2;
 
        return ALIGN(num_bytes, fs_info->extent_root->leafsize << 10);
 }