Commit a520a7e0 authored by Liu Bo's avatar Liu Bo Committed by David Sterba

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: default avatarLiu Bo <bo.li.liu@oracle.com>
Reviewed-by: default avatarJosef Bacik <jbacik@fb.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 3cbf26da
...@@ -6874,7 +6874,7 @@ static int merge_extent_mapping(struct extent_map_tree *em_tree, ...@@ -6874,7 +6874,7 @@ static int merge_extent_mapping(struct extent_map_tree *em_tree,
if (em->block_start < EXTENT_MAP_LAST_BYTE && if (em->block_start < EXTENT_MAP_LAST_BYTE &&
!test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) { !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
em->block_start += start_diff; em->block_start += start_diff;
em->block_len -= start_diff; em->block_len = em->len;
} }
return add_extent_mapping(em_tree, em, 0); return add_extent_mapping(em_tree, em, 0);
} }
......
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