2 files changed, 8 insertions, 7 deletions

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index eb4ddfeeeedc..d6e4f0e09a8c 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3643,12 +3643,6 @@ void ext4_truncate(struct inode *inode)
                         return;
         }
 
-        /*
-         * finish any pending end_io work so we won't run the risk of
-         * converting any truncated blocks to initialized later
-         */
-        ext4_flush_unwritten_io(inode);
-
         if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
                 credits = ext4_writepage_trans_blocks(inode);
         else
diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c
index 755741c211a4..0f65561ab5a5 100644
--- a/fs/ext4/page-io.c
+++ b/fs/ext4/page-io.c
@@ -158,7 +158,14 @@ static void ext4_clear_io_unwritten_flag(ext4_io_end_t *io_end)
                 wake_up_all(ext4_ioend_wq(inode));
 }
 
-/* check a range of space and convert unwritten extents to written. */
+/*
+ * Check a range of space and convert unwritten extents to written. Note that
+ * we are protected from truncate touching same part of extent tree by the
+ * fact that truncate code waits for all DIO to finish (thus exclusion from
+ * direct IO is achieved) and also waits for PageWriteback bits. Thus we
+ * cannot get to ext4_ext_truncate() before all IOs overlapping that range are
+ * completed (happens from ext4_free_ioend()).
+ */
 static int ext4_end_io(ext4_io_end_t *io)
 {
         struct inode *inode = io->inode;