Small update. I've done a strace of the qemu process, filtering for pwrite,pwritev while the guest experiences these I/O errors and posted it to the bug. Kevin Wolf looked at it and says https://bugzilla.redhat.com/show_bug.cgi?id=1204569#c20
> There is one single failing pwritev() call in it: > 3091 <... pwritev resumed> ) = -1 EEXIST (File exists) > Now EEXIST is not an error code that makes any sense for a pwritev() call, > but a > quick search on the internet suggests that btrfs does indeed use this error > code > if something goes wrong internally. You should probably mention this error > code > in your linux-btrfs thread, perhaps it gives the btrfs developers a hint. Chris Murphy -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html