Re: [PATCH, RFC] xfs: add heuristic to flush on rename

[Christoph Hellwig <hch@xxxxxxxxxxxxx>]

> +     /*
> +      * If we are renaming a just-written file over an existing
> +      * file, be pedantic and flush it out if it looks like somebody
> +      * is doing a tmpfile dance, and didn't fsync.  Best effort;
> +      * ignore errors.
> +      */
> +     if (new_inode) {
> +             xfs_inode_t *ip = XFS_I(odentry->d_inode);
> +
> +             if (VN_DIRTY(VFS_I(ip)) && ip->i_delayed_blks > 0)
> +                     filemap_flush(new_inode->i_mapping);
> +     }

IFF we want a heuristic it should be a proper filemap_write_and_wait.  a
non-blocking start of I/O without waiting for it is snake oil.