Ted, I notice in the struct io_manager that there are reserved fields at the end, presumably for adding new methods to this array. Unfortunately, the reserved field is type "int" instead of "long" and as a result there isn't necessarily enough space to hold a function pointer on a 64-bit system. Have you looked at this at all? Presumably as methods are added on 64-bit systems, the array grows slightly larger each time because the pointers are larger than the amount of space removed from the array. Possibly this is harmless, because the consumers of this struct have allocated enough space to handle all of the used fields. I'm not 100% sure of the usage of this struct, but I thought I'd mention it, because I noticed that the 64-bit methods were added there recently. I was going to submit a patch to add a "readahead" method, which we've been using in our "e2scan" tool to improve performance, and I thought it might also be useful for e2fsck speedups. If someone is interested in these I can send them to the list, but the patches won't apply to the current Git tree because of this change. Cheers, Andreas -- Andreas Dilger Sr. Staff Engineer, Lustre Group Sun Microsystems of Canada, Inc. -- 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
