>>>>> "Thomas" == Thomas King <kingttx@xxxxxxxxxxxxxxxxxxxxxxx> writes: Thomas> - T10 DIF (block protect?) aware file system I'm not really sure what the ext4 people are officially planning but I know from conversations with Ted and a few others that there's interest. Wiring up ext4 to the block integrity infrastructure is pretty easy. It's defining the tagging and making fsck use it that's the hard part. Some of that hinges on a userland interface that I haven't quite finished baking yet. However, a filesystem doesn't have to be explicitly DIF-aware to take advantage of it. Sector tagging is just icing on the cake. The current DIF infrastructure automagically protects all I/O that doesn't already have integrity metadata attached. Unfortunately, ext[23] aren't working well with protection turned on right now. The way DIF works is that you add a checksum to the I/O when it is submitted. If there's a mismatch, the HBA or the drive will reject the I/O. And unfortunately both ext2 and ext3 frequently modify pages that are in flight, causing a checksum mismatch. I have yet to try ext4. XFS and btrfs work fine with DIF except for the generic writable mmap hole that I think I'm about to fix. -- Martin K. Petersen Oracle Linux Engineering -- 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
