| blob | d5c9320901c3273b99bcc1b4cda78c5472d9f6fd |
1 .. SPDX-License-Identifier: GPL-2.0
3 .. _netdev-FAQ:
5 ==========
6 netdev FAQ
7 ==========
9 Q: What is netdev?
10 ------------------
11 A: It is a mailing list for all network-related Linux stuff. This
12 includes anything found under net/ (i.e. core code like IPv6) and
13 drivers/net (i.e. hardware specific drivers) in the Linux source tree.
15 Note that some subsystems (e.g. wireless drivers) which have a high
16 volume of traffic have their own specific mailing lists.
18 The netdev list is managed (like many other Linux mailing lists) through
19 VGER (http://vger.kernel.org/) and archives can be found below:
21 - http://marc.info/?l=linux-netdev
22 - http://www.spinics.net/lists/netdev/
24 Aside from subsystems like that mentioned above, all network-related
25 Linux development (i.e. RFC, review, comments, etc.) takes place on
26 netdev.
28 Q: How do the changes posted to netdev make their way into Linux?
29 -----------------------------------------------------------------
30 A: There are always two trees (git repositories) in play. Both are
31 driven by David Miller, the main network maintainer. There is the
32 ``net`` tree, and the ``net-next`` tree. As you can probably guess from
33 the names, the ``net`` tree is for fixes to existing code already in the
34 mainline tree from Linus, and ``net-next`` is where the new code goes
35 for the future release. You can find the trees here:
37 - https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git
38 - https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git
40 Q: How often do changes from these trees make it to the mainline Linus tree?
41 ----------------------------------------------------------------------------
42 A: To understand this, you need to know a bit of background information on
43 the cadence of Linux development. Each new release starts off with a
44 two week "merge window" where the main maintainers feed their new stuff
45 to Linus for merging into the mainline tree. After the two weeks, the
46 merge window is closed, and it is called/tagged ``-rc1``. No new
47 features get mainlined after this -- only fixes to the rc1 content are
48 expected. After roughly a week of collecting fixes to the rc1 content,
49 rc2 is released. This repeats on a roughly weekly basis until rc7
50 (typically; sometimes rc6 if things are quiet, or rc8 if things are in a
51 state of churn), and a week after the last vX.Y-rcN was done, the
52 official vX.Y is released.
54 Relating that to netdev: At the beginning of the 2-week merge window,
55 the ``net-next`` tree will be closed - no new changes/features. The
56 accumulated new content of the past ~10 weeks will be passed onto
57 mainline/Linus via a pull request for vX.Y -- at the same time, the
58 ``net`` tree will start accumulating fixes for this pulled content
59 relating to vX.Y
61 An announcement indicating when ``net-next`` has been closed is usually
62 sent to netdev, but knowing the above, you can predict that in advance.
64 IMPORTANT: Do not send new ``net-next`` content to netdev during the
65 period during which ``net-next`` tree is closed.
67 Shortly after the two weeks have passed (and vX.Y-rc1 is released), the
68 tree for ``net-next`` reopens to collect content for the next (vX.Y+1)
69 release.
71 If you aren't subscribed to netdev and/or are simply unsure if
72 ``net-next`` has re-opened yet, simply check the ``net-next`` git
73 repository link above for any new networking-related commits. You may
74 also check the following website for the current status:
76 http://vger.kernel.org/~davem/net-next.html
78 The ``net`` tree continues to collect fixes for the vX.Y content, and is
79 fed back to Linus at regular (~weekly) intervals. Meaning that the
80 focus for ``net`` is on stabilization and bug fixes.
82 Finally, the vX.Y gets released, and the whole cycle starts over.
84 Q: So where are we now in this cycle?
86 Load the mainline (Linus) page here:
88 https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
90 and note the top of the "tags" section. If it is rc1, it is early in
91 the dev cycle. If it was tagged rc7 a week ago, then a release is
92 probably imminent.
94 Q: How do I indicate which tree (net vs. net-next) my patch should be in?
95 -------------------------------------------------------------------------
96 A: Firstly, think whether you have a bug fix or new "next-like" content.
97 Then once decided, assuming that you use git, use the prefix flag, i.e.
98 ::
100 git format-patch --subject-prefix='PATCH net-next' start..finish
102 Use ``net`` instead of ``net-next`` (always lower case) in the above for
103 bug-fix ``net`` content. If you don't use git, then note the only magic
104 in the above is just the subject text of the outgoing e-mail, and you
105 can manually change it yourself with whatever MUA you are comfortable
106 with.
108 Q: I sent a patch and I'm wondering what happened to it?
109 --------------------------------------------------------
110 Q: How can I tell whether it got merged?
111 A: Start by looking at the main patchworks queue for netdev:
113 http://patchwork.ozlabs.org/project/netdev/list/
115 The "State" field will tell you exactly where things are at with your
116 patch.
118 Q: The above only says "Under Review". How can I find out more?
119 ----------------------------------------------------------------
120 A: Generally speaking, the patches get triaged quickly (in less than
121 48h). So be patient. Asking the maintainer for status updates on your
122 patch is a good way to ensure your patch is ignored or pushed to the
123 bottom of the priority list.
125 Q: I submitted multiple versions of the patch series
126 ----------------------------------------------------
127 Q: should I directly update patchwork for the previous versions of these
128 patch series?
129 A: No, please don't interfere with the patch status on patchwork, leave
130 it to the maintainer to figure out what is the most recent and current
131 version that should be applied. If there is any doubt, the maintainer
132 will reply and ask what should be done.
134 Q: I made changes to only a few patches in a patch series should I resend only those changed?
135 ---------------------------------------------------------------------------------------------
136 A: No, please resend the entire patch series and make sure you do number your
137 patches such that it is clear this is the latest and greatest set of patches
138 that can be applied.
140 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?
141 -------------------------------------------------------------------------------------------------------------------------------------------
142 A: There is no revert possible, once it is pushed out, it stays like that.
143 Please send incremental versions on top of what has been merged in order to fix
144 the patches the way they would look like if your latest patch series was to be
145 merged.
147 Q: How can I tell what patches are queued up for backporting to the various stable releases?
148 --------------------------------------------------------------------------------------------
149 A: Normally Greg Kroah-Hartman collects stable commits himself, but for
150 networking, Dave collects up patches he deems critical for the
151 networking subsystem, and then hands them off to Greg.
153 There is a patchworks queue that you can see here:
155 http://patchwork.ozlabs.org/bundle/davem/stable/?state=*
157 It contains the patches which Dave has selected, but not yet handed off
158 to Greg. If Greg already has the patch, then it will be here:
160 https://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git
162 A quick way to find whether the patch is in this stable-queue is to
163 simply clone the repo, and then git grep the mainline commit ID, e.g.
164 ::
166 stable-queue$ git grep -l 284041ef21fdf2e
167 releases/3.0.84/ipv6-fix-possible-crashes-in-ip6_cork_release.patch
168 releases/3.4.51/ipv6-fix-possible-crashes-in-ip6_cork_release.patch
169 releases/3.9.8/ipv6-fix-possible-crashes-in-ip6_cork_release.patch
170 stable/stable-queue$
172 Q: I see a network patch and I think it should be backported to stable.
173 -----------------------------------------------------------------------
174 Q: Should I request it via stable@vger.kernel.org like the references in
175 the kernel's Documentation/process/stable-kernel-rules.rst file say?
176 A: No, not for networking. Check the stable queues as per above first
177 to see if it is already queued. If not, then send a mail to netdev,
178 listing the upstream commit ID and why you think it should be a stable
179 candidate.
181 Before you jump to go do the above, do note that the normal stable rules
182 in :ref:`Documentation/process/stable-kernel-rules.rst <stable_kernel_rules>`
183 still apply. So you need to explicitly indicate why it is a critical
184 fix and exactly what users are impacted. In addition, you need to
185 convince yourself that you *really* think it has been overlooked,
186 vs. having been considered and rejected.
188 Generally speaking, the longer it has had a chance to "soak" in
189 mainline, the better the odds that it is an OK candidate for stable. So
190 scrambling to request a commit be added the day after it appears should
191 be avoided.
193 Q: I have created a network patch and I think it should be backported to stable.
194 --------------------------------------------------------------------------------
195 Q: Should I add a Cc: stable@vger.kernel.org like the references in the
196 kernel's Documentation/ directory say?
197 A: No. See above answer. In short, if you think it really belongs in
198 stable, then ensure you write a decent commit log that describes who
199 gets impacted by the bug fix and how it manifests itself, and when the
200 bug was introduced. If you do that properly, then the commit will get
201 handled appropriately and most likely get put in the patchworks stable
202 queue if it really warrants it.
204 If you think there is some valid information relating to it being in
205 stable that does *not* belong in the commit log, then use the three dash
206 marker line as described in
207 :ref:`Documentation/process/submitting-patches.rst <the_canonical_patch_format>`
208 to temporarily embed that information into the patch that you send.
210 Q: Are all networking bug fixes backported to all stable releases?
211 ------------------------------------------------------------------
212 A: Due to capacity, Dave could only take care of the backports for the
213 last two stable releases. For earlier stable releases, each stable
214 branch maintainer is supposed to take care of them. If you find any
215 patch is missing from an earlier stable branch, please notify
216 stable@vger.kernel.org with either a commit ID or a formal patch
217 backported, and CC Dave and other relevant networking developers.
219 Q: Is the comment style convention different for the networking content?
220 ------------------------------------------------------------------------
221 A: Yes, in a largely trivial way. Instead of this::
223 /*
224 * foobar blah blah blah
225 * another line of text
226 */
228 it is requested that you make it look like this::
230 /* foobar blah blah blah
231 * another line of text
232 */
234 Q: I am working in existing code that has the former comment style and not the latter.
235 --------------------------------------------------------------------------------------
236 Q: Should I submit new code in the former style or the latter?
237 A: Make it the latter style, so that eventually all code in the domain
238 of netdev is of this format.
240 Q: I found a bug that might have possible security implications or similar.
241 ---------------------------------------------------------------------------
242 Q: Should I mail the main netdev maintainer off-list?**
243 A: No. The current netdev maintainer has consistently requested that
244 people use the mailing lists and not reach out directly. If you aren't
245 OK with that, then perhaps consider mailing security@kernel.org or
246 reading about http://oss-security.openwall.org/wiki/mailing-lists/distros
247 as possible alternative mechanisms.
249 Q: What level of testing is expected before I submit my change?
250 ---------------------------------------------------------------
251 A: If your changes are against ``net-next``, the expectation is that you
252 have tested by layering your changes on top of ``net-next``. Ideally
253 you will have done run-time testing specific to your change, but at a
254 minimum, your changes should survive an ``allyesconfig`` and an
255 ``allmodconfig`` build without new warnings or failures.
257 Q: Any other tips to help ensure my net/net-next patch gets OK'd?
258 -----------------------------------------------------------------
259 A: Attention to detail. Re-read your own work as if you were the
260 reviewer. You can start with using ``checkpatch.pl``, perhaps even with
261 the ``--strict`` flag. But do not be mindlessly robotic in doing so.
262 If your change is a bug fix, make sure your commit log indicates the
263 end-user visible symptom, the underlying reason as to why it happens,
264 and then if necessary, explain why the fix proposed is the best way to
265 get things done. Don't mangle whitespace, and as is common, don't
266 mis-indent function arguments that span multiple lines. If it is your
267 first patch, mail it to yourself so you can test apply it to an
268 unpatched tree to confirm infrastructure didn't mangle it.
270 Finally, go back and read
271 :ref:`Documentation/process/submitting-patches.rst <submittingpatches>`
272 to be sure you are not repeating some common mistake documented there.