ext3: Add replace-on-truncate hueristics for data=writeback mode
In data=writeback mode, start an asynchronous flush when closing a
file which had been previously truncated down to zero. This lowers
the probability of data loss in the case of applications that attempt
to replace a file using truncate.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c
index 5fa453b..0f5bca0 100644
--- a/fs/ext3/inode.c
+++ b/fs/ext3/inode.c
@@ -2346,6 +2346,9 @@
if (!ext3_can_truncate(inode))
return;
+ if (inode->i_size == 0 && ext3_should_writeback_data(inode))
+ ei->i_state |= EXT3_STATE_FLUSH_ON_CLOSE;
+
/*
* We have to lock the EOF page here, because lock_page() nests
* outside journal_start().