On Tue, Jan 21, 2020 at 09:21:18PM -0800, Jerome Glisse wrote: <snip> > > The block device code only need the mapping on io error and they are > different strategy depending on individual fs. fs using buffer_head > can easily be updated. For other they are different solution and they > can be updated one at a time with tailor solution. If I did't misunderstand, how about post-processing fs code without some buffer_head but page->private used as another way rather than a pointer? (Yes, some alternative ways exist such as hacking struct bio_vec...) I wonder the final plan on this from the community, learn new rule and adapt my code anyway.. But in my opinion, such reserve way (page->mapping likewise) is helpful in many respects, I'm not sure we could totally get around all cases without it elegantly... Thank you... Thanks, Gao Xiang
