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/file.c b/fs/ext3/file.c
index 3be1e06..4a04cbb 100644
--- a/fs/ext3/file.c
+++ b/fs/ext3/file.c
@@ -33,6 +33,10 @@
*/
static int ext3_release_file (struct inode * inode, struct file * filp)
{
+ if (EXT3_I(inode)->i_state & EXT3_STATE_FLUSH_ON_CLOSE) {
+ filemap_flush(inode->i_mapping);
+ EXT3_I(inode)->i_state &= ~EXT3_STATE_FLUSH_ON_CLOSE;
+ }
/* if we are the last writer on the inode, drop the block reservation */
if ((filp->f_mode & FMODE_WRITE) &&
(atomic_read(&inode->i_writecount) == 1))