On Sun, Apr 23, 2023 at 11:18:25PM -0700, Darrick J. Wong wrote: > > @@ -876,8 +877,11 @@ iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *i, > > if (iocb->ki_flags & IOCB_NOWAIT) > > iter.flags |= IOMAP_NOWAIT; > > > > + current->backing_dev_info = inode_to_bdi(iter.inode); > > Dumb question from me late on a Sunday night, but does the iomap_unshare > code need to set this too? Since it works by dirtying pagecache folios > without actually changing the contents? A very good question that I have no answer for. The current->backing_dev_info mechanism confuses the heck out of me and appears basically undocumented.