From d57e62b89796f751c9422801cbcd407a9f8dcdc4 Mon Sep 17 00:00:00 2001
From: Chris Mason <chris.mason@oracle.com>
Date: Tue, 31 Mar 2009 13:47:50 -0400
Subject: Btrfs: try to free metadata pages when we free btree blocks

COW means we cycle though blocks fairly quickly, and once we
free an extent on disk, it doesn't make much sense to keep the pages around.

This commit tries to immediately free the page when we free the extent,
which lowers our memory footprint significantly.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
---
 fs/btrfs/extent-tree.c | 4 ++++
 1 file changed, 4 insertions(+)

(limited to 'fs/btrfs')

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 0c482e0d7c4..f5e7cae63d8 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -2384,6 +2384,10 @@ static int __free_extent(struct btrfs_trans_handle *trans,
 		if (owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
 			ret = btrfs_del_csums(trans, root, bytenr, num_bytes);
 			BUG_ON(ret);
+		} else {
+			invalidate_mapping_pages(info->btree_inode->i_mapping,
+			     bytenr >> PAGE_CACHE_SHIFT,
+			     (bytenr + num_bytes - 1) >> PAGE_CACHE_SHIFT);
 		}
 
 		ret = update_block_group(trans, root, bytenr, num_bytes, 0,
-- 
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