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>
This commit is contained in:
Zheng Liu 2013-03-10 21:08:52 -04:00 committed by Theodore Ts'o
parent 921f266bc6
commit cdee78433c

View file

@ -3650,6 +3650,10 @@ ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode,
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 */