On Sat, 2020-09-12 at 00:55 +0100, Al Viro wrote: > On Fri, Sep 11, 2020 at 05:59:04PM -0400, Qian Cai wrote: > > Super easy to reproduce on today's mainline by just fuzzing for a few > > minutes > > on virtiofs (if it ever matters). Any thoughts? > > Usually happens when ->direct_IO() fucks up and reports the wrong amount > of data written/read. We had several bugs like that in the past - see > e.g. 85128b2be673 (fix nfs O_DIRECT advancing iov_iter too much). > > Had there been any recent O_DIRECT-related patches on the filesystems > involved? This is only reproducible using FUSE/virtiofs so far, so I will stare at fuse_direct_IO() until someone can beat me to it.
