ext4: let ext4_ext_map_blocks return EXT4_MAP_UNWRITTEN flag

This commit lets ext4_ext_map_blocks return EXT4_MAP_UNWRITTEN flag
because in later commit ext4_map_blocks needs to use this flag to
determine the extent status.

Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>

1 files changed, 3 insertions, 9 deletions

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index e0e1cb0863f4..084b8212cf95 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -559,16 +559,10 @@ int ext4_map_blocks(handle_t *handle, struct inode *inode,
                 return retval;
 
         /*
-         * When we call get_blocks without the create flag, the
-         * BH_Unwritten flag could have gotten set if the blocks
-         * requested were part of a uninitialized extent.  We need to
-         * clear this flag now that we are committed to convert all or
-         * part of the uninitialized extent to be an initialized
-         * extent.  This is because we need to avoid the combination
-         * of BH_Unwritten and BH_Mapped flags being simultaneously
-         * set on the buffer_head.
+         * Here we clear m_flags because after allocating an new extent,
+         * it will be set again.
          */
-        map->m_flags &= ~EXT4_MAP_UNWRITTEN;
+        map->m_flags &= ~EXT4_MAP_FLAGS;
 
         /*
          * New blocks allocate and/or writing to uninitialized extent