ext4: Don't treat a truncation of a zero-length file as replace-via-truncate

If a non-existent file is opened via O_WRONLY|O_CREAT|O_TRUNC, there's
no need to treat this as a true file truncation, so we shouldn't
activate the replace-via-truncate hueristic.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 2 insertions, 1 deletions

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 2c10d346f7a3..875db944b22f 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4127,7 +4127,8 @@ void ext4_truncate(struct inode *inode)
         if (!ext4_can_truncate(inode))
                 return;
 
-        if (inode->i_size == 0 && !test_opt(inode->i_sb, NO_AUTO_DA_ALLOC))
+        if (ei->i_disksize && inode->i_size == 0 &&
+            !test_opt(inode->i_sb, NO_AUTO_DA_ALLOC))
                 ei->i_state |= EXT4_STATE_DA_ALLOC_CLOSE;
 
         if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) {