On Wed, 2017-05-31 at 13:27 -0700, Andrew Morton wrote: > On Wed, 31 May 2017 08:45:23 -0400 Jeff Layton <jlayton@xxxxxxxxxx> wrote: > > > This is v5 of the patchset to improve how we're tracking and reporting > > errors that occur during pagecache writeback. > > I'm curious to know how you've been testing this? > Is that testing > strong enough for us to be confident that all nature of I/O errors > will be reported to userspace? > That's a tall order. This is a difficult thing to test as these sorts of errors are pretty rare by nature. I have an xfstest that I posted just after this set that demonstrates that it works correctly, at least on ext2/3/4 when run by the ext4 driver (ext2 legacy driver reports too many errors currently). I had btrfs and xfs working on that test too in an earlier incarnation of this set, so I think we can fix this in them as well without too much difficulty. I'm happy to run other tests if someone wants to suggest them. Now, all that said, I don't think this will make things any worse than they are today as far as reporting errors properly to userland goes. It's rather easy for an incidental synchronous writeback request from an internal caller to clear the AS_* flags today. This will at least ensure that we're reporting errors since a well-defined point in time when you call fsync. -- Jeff Layton <jlayton@xxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
