On 09/21/2016 07:14 AM, Paul Jones wrote:
-----Original Message----- From: linux-btrfs-owner@xxxxxxxxxxxxxxx [mailto:linux-btrfs- owner@xxxxxxxxxxxxxxx] On Behalf Of Zygo Blaxell Sent: Wednesday, 21 September 2016 2:56 PM To: linux-btrfs@xxxxxxxxxxxxxxx Subject: btrfs rare silent data corruption with kernel data leak Summary: There seem to be two btrfs bugs here: one loses data on writes, and the other leaks data from the kernel to replace it on reads. It all happens after checksums are verified, so the corruption is entirely silent--no EIO errors, kernel messages, or device event statistics. Compressed extents are corrupted with kernel data leak. Uncompressed extents may not be corrupted, or may be corrupted by deterministically replacing data bytes with zero, or may not be corrupted. No preconditions for corruption are known. Less than one file per hundred thousand seems to be affected. Only specific parts of any file can be affected. Kernels v4.0..v4.5.7 tested, all have the issue.
Zygo, could you please bounce me your original email? Somehow exchange ate it.
If you're seeing this databases that use fsync, it could be related to the fsync fix I put into the last RC. On my boxes it caused crashes, but memory corruptions aren't impossible.
Any chance you can do a controlled experiment to rule out compression? -chris -- 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
