From 14ed0ca6e8236f2d264c4a8faec9e3a2b3d04377 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Fri, 15 Oct 2010 15:23:48 -0400 Subject: [PATCH] Btrfs: don't allocate chunks as aggressively Because the ENOSPC code over reserves super aggressively we end up allocating chunks way more often than we should. For example with my fs_mark tests on a 2gb fs I can end up reserved 1gb just for metadata, when only 34mb of that is being used. So instead check to see if the amount of space actually used is less than 30% of the total space, and if so don't allocate a chunk, but only if we have at least 256mb of free space to make sure we don't put too much pressure on free space. Signed-off-by: Josef Bacik --- fs/btrfs/extent-tree.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 2846cebc942..aca3314ef8b 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -3000,8 +3000,7 @@ static void force_metadata_allocation(struct btrfs_fs_info *info) rcu_read_unlock(); } -static int should_alloc_chunk(struct btrfs_space_info *sinfo, - u64 alloc_bytes) +static int should_alloc_chunk(struct btrfs_space_info *sinfo, u64 alloc_bytes) { u64 num_bytes = sinfo->total_bytes - sinfo->bytes_readonly; @@ -3013,6 +3012,10 @@ static int should_alloc_chunk(struct btrfs_space_info *sinfo, alloc_bytes < div_factor(num_bytes, 8)) return 0; + if (num_bytes > 256 * 1024 * 1024 && + sinfo->bytes_used < div_factor(num_bytes, 3)) + return 0; + return 1; } -- 2.41.0