On Thu, Feb 7, 2019 at 11:22 AM Brian Ledbetter <[email protected]> wrote:
> > > On Thursday, February 7, 2019 at 3:48:32 AM UTC-5, Nadav Har'El wrote: > >> To support the case where the /etc filesystem is read-only, we can do the >> following: In the read-only filesystem, put in /etc/resolv.conf a symbolic >> link to /tmp/resolv.conf, assuming we always mount a writable /tmp. Then, >> when dhcp.cc will write to "/etc/resolv.conf" (overwritten, e.g., open() >> with O_TRUNC), it will actually write to that file on /tmp and succeed. >> > > Ha - That's quite a bit easier than the path I was thinking of, trying to > write some sort of mmap'ed VFS hack to point /etc/resolv.conf to a blob of > kernel memory. This is definitely a better approach. > > Are we guaranteed that every OSv instance will have a writable /tmp > directory? Is that a part of the core manifest? > This is a question for Waldek, who's the expert (and author) of the readonly-filesystem stuff. But I seem to remember it is - that we always mount a writeable, in-memory, file system, because many applications assume they can write stuff there. If we don't do that yet, maybe we should? You can test this by building an image with "fs=rofs". For example, scripts/build fs=rofs image=rogue -- You received this message because you are subscribed to the Google Groups "OSv Development" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
