Hi Rob, On Thu, 2018-02-01 at 17:34 -0600, Rob Landley wrote: > > On 02/01/2018 04:41 PM, Taras Kondratiuk wrote: > > Quoting Mimi Zohar (2018-02-01 13:51:52) > >> On Thu, 2018-02-01 at 11:09 -0600, Rob Landley wrote: > >>> On 02/01/2018 09:55 AM, Mimi Zohar wrote: > >>>> On Thu, 2018-02-01 at 09:20 -0600, Rob Landley wrote: > >>>> > >>>>>> With your patch and specifying "root=tmpfs", dracut is complaining: > >>>>>> > >>>>>> dracut: FATAL: Don't know how to handle 'root=tmpfs' > >>>>>> dracut: refusing to continue > >>>>> > >>>>> [googles]... I do not understand why this package exists. > >>>>> > >>>>> If you're switching to another root filesystem, using a tool that > >>>>> wikipedia[citation needed] says has no purpose but to switch to another > >>>>> root filesystem, (so let's reproduce the kernel infrastructure in > >>>>> userspace while leaving it the kernel too)... why do you need initramfs > >>>>> to be tmpfs? You're using it for half a second, then discarding it, > >>>>> what's the point of it being tmpfs? > >>>> > >>>> Unlike the kernel image which is signed by the distros, the initramfs > >>>> doesn't come signed, because it is built on the target system. Even > >>>> if the initramfs did come signed, it is beneficial to measure and > >>>> appraise the individual files in the initramfs. > >>> > >>> You can still shoot yourself in the foot with tmpfs. People mount a /run > >>> and a /tmp and then as a normal user you can go > >>> https://twitter.com/landley/status/959103235305951233 and maybe the > >>> default should be a little more clever there... > >>> > >>> I'll throw it on the todo heap. :) > >>> > >>>>> Sigh. If people are ok with having rootfs just be tmpfs whenever tmpfs > >>>>> is configured in, even when you're then going to overmount it with > >>>>> something else like you're doing, let's just _remove_ the test. If it > >>>>> can be tmpfs, have it be tmpfs. > >>>> > >>>> Very much appreciated! > >>> > >>> Not yet tested, but something like the attached? (Sorry for the > >>> half-finished doc changes in there, I'm at work and have a 5 minute > >>> break. I can test properly this evening if you don't get to it...) > >> > >> Yes, rootfs is being mounted as tmpfs. > > > > I don't think you can unconditionally replace ramfs with initramfs by > > default. Their behavior is different in some cases (e.g. pivot_root vs > > switch_root) > > Both are switch_root, you can't pivot_root off of either one. (Yes, I > hit that bug and reported it, and they fixed it, back in the day... > http://lists.busybox.net/pipermail/busybox/2006-March/053529.html ) > > > and it can break many systems that expect ramfs by default. > > The use case I told Mimi about off-list (since they stopped cc:ing the > list in one of their replies but the conversation continued) was the guy > who was extracting an initramfs bigger than 50% of system memory, which > worked with initramfs but failed with initmpfs. A quick google didn't > find the original message but it resulted in this blog entry from the > affected party: > > http://www.lightofdawn.org/blog/?viewDetailed=00128 > > I.E. yeah, I know, I need to redo these patches tonight. I'd really like to be able to have rootfs be a tmpfs filesystem. Any time estimate on this patch? thanks! Mimi -- To unsubscribe from this list: send the line "unsubscribe initramfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
