From a520a7e0b548690ea8eb77bb45800459351a7cf5 Mon Sep 17 00:00:00 2001 From: Liu Bo Date: Fri, 5 Jan 2018 12:51:08 -0700 Subject: [PATCH] Btrfs: fix incorrect block_len in merge_extent_mapping %block_len could be checked on deciding if two em are mergeable. merge_extent_mapping() has only added the front pad if the front part of em gets truncated, but it's possible that the end part gets truncated. For both compressed extent and inline extent, em->block_len is not adjusted accordingly, and for regular extent, em->block_len always equals to em->len, hence this sets em->block_len with em->len. Signed-off-by: Liu Bo Reviewed-by: Josef Bacik Signed-off-by: David Sterba --- fs/btrfs/inode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 633b83b..f9fd8b1 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -6874,7 +6874,7 @@ static int merge_extent_mapping(struct extent_map_tree *em_tree, if (em->block_start < EXTENT_MAP_LAST_BYTE && !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) { em->block_start += start_diff; - em->block_len -= start_diff; + em->block_len = em->len; } return add_extent_mapping(em_tree, em, 0); } -- 2.7.4