On Wed, Mar 27, 2013 at 09:51:55AM -0400, Theodore Ts'o wrote:
> Ah, now I see. Thanks for sending the stack trace. On the failure
> path, we're calling the inline function ext4_truncate_filaed_write()
> and this is calling ext4_truncate().
>
> But I'm now wondering if we need to take the i_data_sem mutex in
> ext4_truncate_failed_write().
>
> Otherwise, couldn't we end up with problems where a failed write calls
> ext4_truncate() without i_data_sem(), and that races with something
> else --- say, a punch or truncate call to that same inode?
I don't think we need to take i_mutex lock honestly. In ext4_symlink
when we call __page_symlink() the new inode doesn't access yet. So no
one can do a punching hole or truncation to this inode. But I also
think we need to add WARN_ON in ext4_truncate because i_mutex lock is
used to serialize truncate/punch hole and buffered io.
Regards,
- Zheng
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
