The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 21a94f7acf0f748599ea552af5d9ee7d7e41c72f Mon Sep 17 00:00:00 2001
From: Josef Bacik <josef@xxxxxxxxxxxxxx>
Date: Thu, 11 Oct 2018 15:54:03 -0400
Subject: [PATCH] btrfs: reset max_extent_size properly
If we use up our block group before allocating a new one we'll easily
get a max_extent_size that's set really really low, which will result in
a lot of fragmentation. We need to make sure we're resetting the
max_extent_size when we add a new chunk or add new space.
CC: stable@xxxxxxxxxxxxxxx # 4.4+
Reviewed-by: Filipe Manana <fdmanana@xxxxxxxx>
Signed-off-by: Josef Bacik <josef@xxxxxxxxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index b6d930356dd3..87d6666cd8e3 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -4565,6 +4565,7 @@ static int do_chunk_alloc(struct btrfs_trans_handle *trans, u64 flags,
goto out;
} else {
ret = 1;
+ space_info->max_extent_size = 0;
}
space_info->force_alloc = CHUNK_ALLOC_NO_FORCE;
@@ -6459,6 +6460,7 @@ static void btrfs_free_reserved_bytes(struct btrfs_block_group_cache *cache,
space_info->bytes_readonly += num_bytes;
cache->reserved -= num_bytes;
space_info->bytes_reserved -= num_bytes;
+ space_info->max_extent_size = 0;
if (delalloc)
cache->delalloc_bytes -= num_bytes;
