ext4: fix wrong m_len value after unwritten extent conversion
The ext4_ext_handle_uninitialized_extents() function was assuming the
return value of ext4_ext_map_blocks() is equal to map->m_len. This
incorrect assumption was harmless until we started use status tree as
a extent cache because we need to update status tree according to
'm_len' value.
Meanwhile this commit marks EXT4_MAP_MAPPED flag after unwritten extent
conversion. It shouldn't cause a bug because we update status tree
according to checking EXT4_MAP_UNWRITTEN flag. But it should be fixed.
After applied this commit, the following error message from self-testing
infrastructure disappears.
...
kernel: ES len assertation failed for inode: 230 retval 1 !=
map->m_len 3 in ext4_map_blocks (allocation)
...
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Dmitry Monakhov <dmonakhov@openvz.org>
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 25c86aa..110e85a 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3650,6 +3650,10 @@
path, map->m_len);
} else
err = ret;
+ map->m_flags |= EXT4_MAP_MAPPED;
+ if (allocated > map->m_len)
+ allocated = map->m_len;
+ map->m_len = allocated;
goto out2;
}
/* buffered IO case */