1 files changed, 25 insertions, 11 deletions

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 10539e364283..715264b4bae4 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -2807,6 +2807,8 @@ fix_extent_len:
  * into three uninitialized extent(at most). After IO complete, the part
  * being filled will be convert to initialized by the end_io callback function
  * via ext4_convert_unwritten_extents().
+ *
+ * Returns the size of uninitialized extent to be written on success.
  */
 static int ext4_split_unwritten_extents(handle_t *handle,
                                         struct inode *inode,
@@ -2824,7 +2826,6 @@ static int ext4_split_unwritten_extents(handle_t *handle,
         unsigned int allocated, ee_len, depth;
         ext4_fsblk_t newblock;
         int err = 0;
-        int ret = 0;
 
         ext_debug("ext4_split_unwritten_extents: inode %lu,"
                   "iblock %llu, max_blocks %u\n", inode->i_ino,
@@ -2842,12 +2843,12 @@ static int ext4_split_unwritten_extents(handle_t *handle,
         ext4_ext_store_pblock(&orig_ex, ext_pblock(ex));
 
         /*
-         * if the entire unintialized extent length less than
-         * the size of extent to write, there is no need to split
-         * uninitialized extent
+         * If the uninitialized extent begins at the same logical
+         * block where the write begins, and the write completely
+         * covers the extent, then we don't need to split it.
          */
-        if (allocated <= max_blocks)
-                return ret;
+        if ((iblock == ee_block) && (allocated <= max_blocks))
+                return allocated;
 
         err = ext4_ext_get_access(handle, inode, path + depth);
         if (err)
@@ -3048,12 +3049,18 @@ ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode,
                 ret = ext4_split_unwritten_extents(handle,
                                                 inode, path, iblock,
                                                 max_blocks, flags);
-                /* flag the io_end struct that we need convert when IO done */
+                /*
+                 * Flag the inode(non aio case) or end_io struct (aio case)
+                 * that this IO needs to convertion to written when IO is
+                 * completed
+                 */
                 if (io)
                         io->flag = DIO_AIO_UNWRITTEN;
+                else
+                        EXT4_I(inode)->i_state |= EXT4_STATE_DIO_UNWRITTEN;
                 goto out;
         }
-        /* DIO end_io complete, convert the filled extent to written */
+        /* async DIO end_io complete, convert the filled extent to written */
         if (flags == EXT4_GET_BLOCKS_DIO_CONVERT_EXT) {
                 ret = ext4_convert_unwritten_extents_dio(handle, inode,
                                                         path);
@@ -3295,10 +3302,16 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
                  * To avoid unecessary convertion for every aio dio rewrite
                  * to the mid of file, here we flag the IO that is really
                  * need the convertion.
-                 *
+                 * For non asycn direct IO case, flag the inode state
+                 * that we need to perform convertion when IO is done.
                  */
-                if (io && flags == EXT4_GET_BLOCKS_DIO_CREATE_EXT)
-                        io->flag = DIO_AIO_UNWRITTEN;
+                if (flags == EXT4_GET_BLOCKS_DIO_CREATE_EXT) {
+                        if (io)
+                                io->flag = DIO_AIO_UNWRITTEN;
+                        else
+                                EXT4_I(inode)->i_state |=
+                                        EXT4_STATE_DIO_UNWRITTEN;;
+                }
         }
         err = ext4_ext_insert_extent(handle, inode, path, &newex, flags);
         if (err) {
@@ -3519,6 +3532,7 @@ retry:
  *
  * This function is called from the direct IO end io call back
  * function, to convert the fallocated extents after IO is completed.
+ * Returns 0 on success.
  */
 int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset,
                                     loff_t len)