On Fri, Apr 01, 2016 at 02:35:01PM +0800, Qu Wenruo wrote: > @@ -5815,6 +5817,23 @@ out_fail: > } > if (delalloc_lock) > mutex_unlock(&BTRFS_I(inode)->delalloc_mutex); > + /* > + * The number of metadata bytes is calculated by the difference > + * between outstanding_extents and reserved_extents. Sometimes though > + * reserve_metadata_bytes() fails to reserve the wanted metadata bytes, > + * indeed it has already done some work to reclaim metadata space, hence > + * both outstanding_extents and reserved_extents would have changed and > + * the bytes we try to reserve would also has changed(may be smaller). > + * So here we try to reserve again. This is much useful for online > + * dedupe, which will easily eat almost all meta space. > + * > + * XXX: Indeed here 3 is arbitrarily choosed, it's a good workaround for > + * online dedupe, later we should find a better method to avoid dedupe > + * enospc issue. > + */ > + if (unlikely(ret == -ENOSPC && loops++ < 3)) > + goto again; > + This does not seem right and needs to be addressed properly before I consider adding the patchset to for-next. I don't have idea how to fix it. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
