On Tue, Jan 19, 2021 at 07:06:54PM +0800, Rokudo Yan wrote: > on Mon, Jan 18, 2021 at 5:27 PM Alessio Balsini <bals...@android.com> wrote: > > > > This is the 11th version of the series, rebased on top of v5.11-rc4. > > Please find the changelog at the bottom of this cover letter. > > > > Add support for file system passthrough read/write of files when enabled > > in userspace through the option FUSE_PASSTHROUGH. > [...] > > > Hi Allesio, > > Could you please add support for passthrough mmap too ? > If the fuse file opened with passthrough actived, and then map (shared) to > (another) process > address space using mmap interface. As access the file with mmap will pass > the vfs cache of fuse, > but access the file with read/write will bypass the vfs cache of fuse, this > may cause inconsistency. > eg. the reader read the fuse file with mmap() and the writer modify the file > with write(), the reader > may not see the modification immediately since the writer bypass the vfs > cache of fuse. > Actually we have already meet an issue caused by the inconsistency after > applying fuse passthrough > scheme to our product. > > Thanks, > yanwu.
Hi yanwu, Thank you for your interest in this change. FUSE passthrough for mmap is an extension that is already in my TODO list, together with passthrough for directories. For now I would prefer to keep this series minimal to make the review process leaner and simpler. I will start working on extending this series with new features and addressing more corner cases as soon as these changes get merged, what do you think? Thanks, Alessio
