Florian, Am 20.05.2017 um 20:39 schrieb Florian Fainelli: > Hello, > > On 05/20/2017 09:12 AM, Richard Weinberger wrote: >> Hi! >> >> These days I had an interesting discussion with Christoph about overlayfs and >> its burden. The main use-case of overlayfs in combination with UBIFS is >> having a >> squashfs as lower and UBIFS as upper directory. Such that all changes to the >> read-only squashfs go into UBIFS. Upon a factory reset all files within the >> UBIFS will be removed and the merged directory is clean again. Christoph >> argued >> that such a functionality could be achieved without overlayfs if the >> filesystem >> supported something like pre-seeded files or directories. This would lower >> memory pressure and complexity. > > As you may know, OpenWrt/LEDE have been using this scheme for many years > now (before it was named overlayfs, this was called mini fanout overlay > ~10 yrs ago) with squashfs + jffs2 before on P-NOR flashes. There are > still devices like those that benefit from squashfs(ro)+jffs2(rw), so > while bringing a similar functionality using UBIFS exclusively would be > interesting, it would still make Linux distribution want to support a > more generic scheme which is using overlayfs as well.
UBIFS will still support overlayfs and adding a pre-seed mechanism to UBIFS will not block generic solutions. Maybe we can add a generic interface to VFS at some point if other filesystems support that too. :-) Thanks, //richard _______________________________________________ Lede-dev mailing list Lede-dev@lists.infradead.org http://lists.infradead.org/mailman/listinfo/lede-dev
