| .. SPDX-License-Identifier: GPL-2.0 |
| |
| .. _netdev-FAQ: |
| |
| ========== |
| netdev FAQ |
| ========== |
| |
| Q: What is netdev? |
| ------------------ |
| A: It is a mailing list for all network-related Linux stuff. This |
| includes anything found under net/ (i.e. core code like IPv6) and |
| drivers/net (i.e. hardware specific drivers) in the Linux source tree. |
| |
| Note that some subsystems (e.g. wireless drivers) which have a high |
| volume of traffic have their own specific mailing lists. |
| |
| The netdev list is managed (like many other Linux mailing lists) through |
| VGER (http://vger.kernel.org/) and archives can be found below: |
| |
| - http://marc.info/?l=linux-netdev |
| - http://www.spinics.net/lists/netdev/ |
| |
| Aside from subsystems like that mentioned above, all network-related |
| Linux development (i.e. RFC, review, comments, etc.) takes place on |
| netdev. |
| |
| Q: How do the changes posted to netdev make their way into Linux? |
| ----------------------------------------------------------------- |
| A: There are always two trees (git repositories) in play. Both are |
| driven by David Miller, the main network maintainer. There is the |
| ``net`` tree, and the ``net-next`` tree. As you can probably guess from |
| the names, the ``net`` tree is for fixes to existing code already in the |
| mainline tree from Linus, and ``net-next`` is where the new code goes |
| for the future release. You can find the trees here: |
| |
| - https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git |
| - https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git |
| |
| Q: How often do changes from these trees make it to the mainline Linus tree? |
| ---------------------------------------------------------------------------- |
| A: To understand this, you need to know a bit of background information on |
| the cadence of Linux development. Each new release starts off with a |
| two week "merge window" where the main maintainers feed their new stuff |
| to Linus for merging into the mainline tree. After the two weeks, the |
| merge window is closed, and it is called/tagged ``-rc1``. No new |
| features get mainlined after this -- only fixes to the rc1 content are |
| expected. After roughly a week of collecting fixes to the rc1 content, |
| rc2 is released. This repeats on a roughly weekly basis until rc7 |
| (typically; sometimes rc6 if things are quiet, or rc8 if things are in a |
| state of churn), and a week after the last vX.Y-rcN was done, the |
| official vX.Y is released. |
| |
| Relating that to netdev: At the beginning of the 2-week merge window, |
| the ``net-next`` tree will be closed - no new changes/features. The |
| accumulated new content of the past ~10 weeks will be passed onto |
| mainline/Linus via a pull request for vX.Y -- at the same time, the |
| ``net`` tree will start accumulating fixes for this pulled content |
| relating to vX.Y |
| |
| An announcement indicating when ``net-next`` has been closed is usually |
| sent to netdev, but knowing the above, you can predict that in advance. |
| |
| IMPORTANT: Do not send new ``net-next`` content to netdev during the |
| period during which ``net-next`` tree is closed. |
| |
| Shortly after the two weeks have passed (and vX.Y-rc1 is released), the |
| tree for ``net-next`` reopens to collect content for the next (vX.Y+1) |
| release. |
| |
| If you aren't subscribed to netdev and/or are simply unsure if |
| ``net-next`` has re-opened yet, simply check the ``net-next`` git |
| repository link above for any new networking-related commits. You may |
| also check the following website for the current status: |
| |
| http://vger.kernel.org/~davem/net-next.html |
| |
| The ``net`` tree continues to collect fixes for the vX.Y content, and is |
| fed back to Linus at regular (~weekly) intervals. Meaning that the |
| focus for ``net`` is on stabilization and bug fixes. |
| |
| Finally, the vX.Y gets released, and the whole cycle starts over. |
| |
| Q: So where are we now in this cycle? |
| |
| Load the mainline (Linus) page here: |
| |
| https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git |
| |
| and note the top of the "tags" section. If it is rc1, it is early in |
| the dev cycle. If it was tagged rc7 a week ago, then a release is |
| probably imminent. |
| |
| Q: How do I indicate which tree (net vs. net-next) my patch should be in? |
| ------------------------------------------------------------------------- |
| A: Firstly, think whether you have a bug fix or new "next-like" content. |
| Then once decided, assuming that you use git, use the prefix flag, i.e. |
| :: |
| |
| git format-patch --subject-prefix='PATCH net-next' start..finish |
| |
| Use ``net`` instead of ``net-next`` (always lower case) in the above for |
| bug-fix ``net`` content. If you don't use git, then note the only magic |
| in the above is just the subject text of the outgoing e-mail, and you |
| can manually change it yourself with whatever MUA you are comfortable |
| with. |
| |
| Q: I sent a patch and I'm wondering what happened to it? |
| -------------------------------------------------------- |
| Q: How can I tell whether it got merged? |
| A: Start by looking at the main patchworks queue for netdev: |
| |
| https://patchwork.kernel.org/project/netdevbpf/list/ |
| |
| The "State" field will tell you exactly where things are at with your |
| patch. |
| |
| Q: The above only says "Under Review". How can I find out more? |
| ---------------------------------------------------------------- |
| A: Generally speaking, the patches get triaged quickly (in less than |
| 48h). So be patient. Asking the maintainer for status updates on your |
| patch is a good way to ensure your patch is ignored or pushed to the |
| bottom of the priority list. |
| |
| Q: I submitted multiple versions of the patch series |
| ---------------------------------------------------- |
| Q: should I directly update patchwork for the previous versions of these |
| patch series? |
| A: No, please don't interfere with the patch status on patchwork, leave |
| it to the maintainer to figure out what is the most recent and current |
| version that should be applied. If there is any doubt, the maintainer |
| will reply and ask what should be done. |
| |
| Q: I made changes to only a few patches in a patch series should I resend only those changed? |
| --------------------------------------------------------------------------------------------- |
| A: No, please resend the entire patch series and make sure you do number your |
| patches such that it is clear this is the latest and greatest set of patches |
| that can be applied. |
| |
| Q: I submitted multiple versions of a patch series and it looks like a version other than the last one has been accepted, what should I do? |
| ------------------------------------------------------------------------------------------------------------------------------------------- |
| A: There is no revert possible, once it is pushed out, it stays like that. |
| Please send incremental versions on top of what has been merged in order to fix |
| the patches the way they would look like if your latest patch series was to be |
| merged. |
| |
| Q: How can I tell what patches are queued up for backporting to the various stable releases? |
| -------------------------------------------------------------------------------------------- |
| A: Normally Greg Kroah-Hartman collects stable commits himself, but for |
| networking, Dave collects up patches he deems critical for the |
| networking subsystem, and then hands them off to Greg. |
| |
| There is a patchworks queue that you can see here: |
| |
| https://patchwork.kernel.org/bundle/netdev/stable/?state=* |
| |
| It contains the patches which Dave has selected, but not yet handed off |
| to Greg. If Greg already has the patch, then it will be here: |
| |
| https://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git |
| |
| A quick way to find whether the patch is in this stable-queue is to |
| simply clone the repo, and then git grep the mainline commit ID, e.g. |
| :: |
| |
| stable-queue$ git grep -l 284041ef21fdf2e |
| releases/3.0.84/ipv6-fix-possible-crashes-in-ip6_cork_release.patch |
| releases/3.4.51/ipv6-fix-possible-crashes-in-ip6_cork_release.patch |
| releases/3.9.8/ipv6-fix-possible-crashes-in-ip6_cork_release.patch |
| stable/stable-queue$ |
| |
| Q: I see a network patch and I think it should be backported to stable. |
| ----------------------------------------------------------------------- |
| Q: Should I request it via stable@vger.kernel.org like the references in |
| the kernel's Documentation/process/stable-kernel-rules.rst file say? |
| A: No, not for networking. Check the stable queues as per above first |
| to see if it is already queued. If not, then send a mail to netdev, |
| listing the upstream commit ID and why you think it should be a stable |
| candidate. |
| |
| Before you jump to go do the above, do note that the normal stable rules |
| in :ref:`Documentation/process/stable-kernel-rules.rst <stable_kernel_rules>` |
| still apply. So you need to explicitly indicate why it is a critical |
| fix and exactly what users are impacted. In addition, you need to |
| convince yourself that you *really* think it has been overlooked, |
| vs. having been considered and rejected. |
| |
| Generally speaking, the longer it has had a chance to "soak" in |
| mainline, the better the odds that it is an OK candidate for stable. So |
| scrambling to request a commit be added the day after it appears should |
| be avoided. |
| |
| Q: I have created a network patch and I think it should be backported to stable. |
| -------------------------------------------------------------------------------- |
| Q: Should I add a Cc: stable@vger.kernel.org like the references in the |
| kernel's Documentation/ directory say? |
| A: No. See above answer. In short, if you think it really belongs in |
| stable, then ensure you write a decent commit log that describes who |
| gets impacted by the bug fix and how it manifests itself, and when the |
| bug was introduced. If you do that properly, then the commit will get |
| handled appropriately and most likely get put in the patchworks stable |
| queue if it really warrants it. |
| |
| If you think there is some valid information relating to it being in |
| stable that does *not* belong in the commit log, then use the three dash |
| marker line as described in |
| :ref:`Documentation/process/submitting-patches.rst <the_canonical_patch_format>` |
| to temporarily embed that information into the patch that you send. |
| |
| Q: Are all networking bug fixes backported to all stable releases? |
| ------------------------------------------------------------------ |
| A: Due to capacity, Dave could only take care of the backports for the |
| last two stable releases. For earlier stable releases, each stable |
| branch maintainer is supposed to take care of them. If you find any |
| patch is missing from an earlier stable branch, please notify |
| stable@vger.kernel.org with either a commit ID or a formal patch |
| backported, and CC Dave and other relevant networking developers. |
| |
| Q: Is the comment style convention different for the networking content? |
| ------------------------------------------------------------------------ |
| A: Yes, in a largely trivial way. Instead of this:: |
| |
| /* |
| * foobar blah blah blah |
| * another line of text |
| */ |
| |
| it is requested that you make it look like this:: |
| |
| /* foobar blah blah blah |
| * another line of text |
| */ |
| |
| Q: I am working in existing code that has the former comment style and not the latter. |
| -------------------------------------------------------------------------------------- |
| Q: Should I submit new code in the former style or the latter? |
| A: Make it the latter style, so that eventually all code in the domain |
| of netdev is of this format. |
| |
| Q: I found a bug that might have possible security implications or similar. |
| --------------------------------------------------------------------------- |
| Q: Should I mail the main netdev maintainer off-list?** |
| A: No. The current netdev maintainer has consistently requested that |
| people use the mailing lists and not reach out directly. If you aren't |
| OK with that, then perhaps consider mailing security@kernel.org or |
| reading about http://oss-security.openwall.org/wiki/mailing-lists/distros |
| as possible alternative mechanisms. |
| |
| Q: What level of testing is expected before I submit my change? |
| --------------------------------------------------------------- |
| A: If your changes are against ``net-next``, the expectation is that you |
| have tested by layering your changes on top of ``net-next``. Ideally |
| you will have done run-time testing specific to your change, but at a |
| minimum, your changes should survive an ``allyesconfig`` and an |
| ``allmodconfig`` build without new warnings or failures. |
| |
| Q: How do I post corresponding changes to user space components? |
| ---------------------------------------------------------------- |
| A: User space code exercising kernel features should be posted |
| alongside kernel patches. This gives reviewers a chance to see |
| how any new interface is used and how well it works. |
| |
| When user space tools reside in the kernel repo itself all changes |
| should generally come as one series. If series becomes too large |
| or the user space project is not reviewed on netdev include a link |
| to a public repo where user space patches can be seen. |
| |
| In case user space tooling lives in a separate repository but is |
| reviewed on netdev (e.g. patches to `iproute2` tools) kernel and |
| user space patches should form separate series (threads) when posted |
| to the mailing list, e.g.:: |
| |
| [PATCH net-next 0/3] net: some feature cover letter |
| └─ [PATCH net-next 1/3] net: some feature prep |
| └─ [PATCH net-next 2/3] net: some feature do it |
| └─ [PATCH net-next 3/3] selftest: net: some feature |
| |
| [PATCH iproute2-next] ip: add support for some feature |
| |
| Posting as one thread is discouraged because it confuses patchwork |
| (as of patchwork 2.2.2). |
| |
| Q: Any other tips to help ensure my net/net-next patch gets OK'd? |
| ----------------------------------------------------------------- |
| A: Attention to detail. Re-read your own work as if you were the |
| reviewer. You can start with using ``checkpatch.pl``, perhaps even with |
| the ``--strict`` flag. But do not be mindlessly robotic in doing so. |
| If your change is a bug fix, make sure your commit log indicates the |
| end-user visible symptom, the underlying reason as to why it happens, |
| and then if necessary, explain why the fix proposed is the best way to |
| get things done. Don't mangle whitespace, and as is common, don't |
| mis-indent function arguments that span multiple lines. If it is your |
| first patch, mail it to yourself so you can test apply it to an |
| unpatched tree to confirm infrastructure didn't mangle it. |
| |
| Finally, go back and read |
| :ref:`Documentation/process/submitting-patches.rst <submittingpatches>` |
| to be sure you are not repeating some common mistake documented there. |
