Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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1
2Information you need to know about netdev
3-----------------------------------------
4
5Q: What is netdev?
6
7A: It is a mailing list for all network-related Linux stuff. This includes
8 anything found under net/ (i.e. core code like IPv6) and drivers/net
9 (i.e. hardware specific drivers) in the Linux source tree.
10
11 Note that some subsystems (e.g. wireless drivers) which have a high volume
12 of traffic have their own specific mailing lists.
13
14 The netdev list is managed (like many other Linux mailing lists) through
15 VGER ( http://vger.kernel.org/ ) and archives can be found below:
16
17 http://marc.info/?l=linux-netdev
18 http://www.spinics.net/lists/netdev/
19
20 Aside from subsystems like that mentioned above, all network-related Linux
21 development (i.e. RFC, review, comments, etc.) takes place on netdev.
22
23Q: How do the changes posted to netdev make their way into Linux?
24
25A: There are always two trees (git repositories) in play. Both are driven
26 by David Miller, the main network maintainer. There is the "net" tree,
27 and the "net-next" tree. As you can probably guess from the names, the
28 net tree is for fixes to existing code already in the mainline tree from
29 Linus, and net-next is where the new code goes for the future release.
30 You can find the trees here:
31
32 https://git.kernel.org/pub/scm/linux/kernel/git/davem/net.git
33 https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git
34
35Q: How often do changes from these trees make it to the mainline Linus tree?
36
37A: To understand this, you need to know a bit of background information
38 on the cadence of Linux development. Each new release starts off with
39 a two week "merge window" where the main maintainers feed their new
40 stuff to Linus for merging into the mainline tree. After the two weeks,
41 the merge window is closed, and it is called/tagged "-rc1". No new
42 features get mainlined after this -- only fixes to the rc1 content
43 are expected. After roughly a week of collecting fixes to the rc1
44 content, rc2 is released. This repeats on a roughly weekly basis
45 until rc7 (typically; sometimes rc6 if things are quiet, or rc8 if
46 things are in a state of churn), and a week after the last vX.Y-rcN
47 was done, the official "vX.Y" is released.
48
49 Relating that to netdev: At the beginning of the 2-week merge window,
50 the net-next tree will be closed - no new changes/features. The
51 accumulated new content of the past ~10 weeks will be passed onto
52 mainline/Linus via a pull request for vX.Y -- at the same time,
53 the "net" tree will start accumulating fixes for this pulled content
54 relating to vX.Y
55
56 An announcement indicating when net-next has been closed is usually
57 sent to netdev, but knowing the above, you can predict that in advance.
58
59 IMPORTANT: Do not send new net-next content to netdev during the
60 period during which net-next tree is closed.
61
62 Shortly after the two weeks have passed (and vX.Y-rc1 is released), the
63 tree for net-next reopens to collect content for the next (vX.Y+1) release.
64
65 If you aren't subscribed to netdev and/or are simply unsure if net-next
66 has re-opened yet, simply check the net-next git repository link above for
67 any new networking-related commits. You may also check the following
68 website for the current status:
69
70 http://vger.kernel.org/~davem/net-next.html
71
72 The "net" tree continues to collect fixes for the vX.Y content, and
73 is fed back to Linus at regular (~weekly) intervals. Meaning that the
74 focus for "net" is on stabilization and bugfixes.
75
76 Finally, the vX.Y gets released, and the whole cycle starts over.
77
78Q: So where are we now in this cycle?
79
80A: Load the mainline (Linus) page here:
81
82 https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
83
84 and note the top of the "tags" section. If it is rc1, it is early
85 in the dev cycle. If it was tagged rc7 a week ago, then a release
86 is probably imminent.
87
88Q: How do I indicate which tree (net vs. net-next) my patch should be in?
89
90A: Firstly, think whether you have a bug fix or new "next-like" content.
91 Then once decided, assuming that you use git, use the prefix flag, i.e.
92
93 git format-patch --subject-prefix='PATCH net-next' start..finish
94
95 Use "net" instead of "net-next" (always lower case) in the above for
96 bug-fix net content. If you don't use git, then note the only magic in
97 the above is just the subject text of the outgoing e-mail, and you can
98 manually change it yourself with whatever MUA you are comfortable with.
99
100Q: I sent a patch and I'm wondering what happened to it. How can I tell
101 whether it got merged?
102
103A: Start by looking at the main patchworks queue for netdev:
104
105 http://patchwork.ozlabs.org/project/netdev/list/
106
107 The "State" field will tell you exactly where things are at with
108 your patch.
109
110Q: The above only says "Under Review". How can I find out more?
111
112A: Generally speaking, the patches get triaged quickly (in less than 48h).
113 So be patient. Asking the maintainer for status updates on your
114 patch is a good way to ensure your patch is ignored or pushed to
115 the bottom of the priority list.
116
117Q: I submitted multiple versions of the patch series, should I directly update
118 patchwork for the previous versions of these patch series?
119
120A: No, please don't interfere with the patch status on patchwork, leave it to
121 the maintainer to figure out what is the most recent and current version that
122 should be applied. If there is any doubt, the maintainer will reply and ask
123 what should be done.
124
125Q: How can I tell what patches are queued up for backporting to the
126 various stable releases?
127
128A: Normally Greg Kroah-Hartman collects stable commits himself, but
129 for networking, Dave collects up patches he deems critical for the
130 networking subsystem, and then hands them off to Greg.
131
132 There is a patchworks queue that you can see here:
133 http://patchwork.ozlabs.org/bundle/davem/stable/?state=*
134
135 It contains the patches which Dave has selected, but not yet handed
136 off to Greg. If Greg already has the patch, then it will be here:
137 https://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git
138
139 A quick way to find whether the patch is in this stable-queue is
140 to simply clone the repo, and then git grep the mainline commit ID, e.g.
141
142 stable-queue$ git grep -l 284041ef21fdf2e
143 releases/3.0.84/ipv6-fix-possible-crashes-in-ip6_cork_release.patch
144 releases/3.4.51/ipv6-fix-possible-crashes-in-ip6_cork_release.patch
145 releases/3.9.8/ipv6-fix-possible-crashes-in-ip6_cork_release.patch
146 stable/stable-queue$
147
148Q: I see a network patch and I think it should be backported to stable.
149 Should I request it via "stable@vger.kernel.org" like the references in
150 the kernel's Documentation/process/stable-kernel-rules.rst file say?
151
152A: No, not for networking. Check the stable queues as per above 1st to see
153 if it is already queued. If not, then send a mail to netdev, listing
154 the upstream commit ID and why you think it should be a stable candidate.
155
156 Before you jump to go do the above, do note that the normal stable rules
157 in Documentation/process/stable-kernel-rules.rst still apply. So you need to
158 explicitly indicate why it is a critical fix and exactly what users are
159 impacted. In addition, you need to convince yourself that you _really_
160 think it has been overlooked, vs. having been considered and rejected.
161
162 Generally speaking, the longer it has had a chance to "soak" in mainline,
163 the better the odds that it is an OK candidate for stable. So scrambling
164 to request a commit be added the day after it appears should be avoided.
165
166Q: I have created a network patch and I think it should be backported to
167 stable. Should I add a "Cc: stable@vger.kernel.org" like the references
168 in the kernel's Documentation/ directory say?
169
170A: No. See above answer. In short, if you think it really belongs in
171 stable, then ensure you write a decent commit log that describes who
172 gets impacted by the bugfix and how it manifests itself, and when the
173 bug was introduced. If you do that properly, then the commit will
174 get handled appropriately and most likely get put in the patchworks
175 stable queue if it really warrants it.
176
177 If you think there is some valid information relating to it being in
178 stable that does _not_ belong in the commit log, then use the three
179 dash marker line as described in Documentation/process/submitting-patches.rst to
180 temporarily embed that information into the patch that you send.
181
182Q: Are all networking bug fixes backported to all stable releases?
183
184A: Due to capacity, Dave could only take care of the backports for the last
185 2 stable releases. For earlier stable releases, each stable branch maintainer
186 is supposed to take care of them. If you find any patch is missing from an
187 earlier stable branch, please notify stable@vger.kernel.org with either a
188 commit ID or a formal patch backported, and CC Dave and other relevant
189 networking developers.
190
191Q: Someone said that the comment style and coding convention is different
192 for the networking content. Is this true?
193
194A: Yes, in a largely trivial way. Instead of this:
195
196 /*
197 * foobar blah blah blah
198 * another line of text
199 */
200
201 it is requested that you make it look like this:
202
203 /* foobar blah blah blah
204 * another line of text
205 */
206
207Q: I am working in existing code that has the former comment style and not the
208 latter. Should I submit new code in the former style or the latter?
209
210A: Make it the latter style, so that eventually all code in the domain of
211 netdev is of this format.
212
213Q: I found a bug that might have possible security implications or similar.
214 Should I mail the main netdev maintainer off-list?
215
216A: No. The current netdev maintainer has consistently requested that people
217 use the mailing lists and not reach out directly. If you aren't OK with
218 that, then perhaps consider mailing "security@kernel.org" or reading about
219 http://oss-security.openwall.org/wiki/mailing-lists/distros
220 as possible alternative mechanisms.
221
222Q: What level of testing is expected before I submit my change?
223
224A: If your changes are against net-next, the expectation is that you
225 have tested by layering your changes on top of net-next. Ideally you
226 will have done run-time testing specific to your change, but at a
227 minimum, your changes should survive an "allyesconfig" and an
228 "allmodconfig" build without new warnings or failures.
229
230Q: Any other tips to help ensure my net/net-next patch gets OK'd?
231
232A: Attention to detail. Re-read your own work as if you were the
233 reviewer. You can start with using checkpatch.pl, perhaps even
234 with the "--strict" flag. But do not be mindlessly robotic in
235 doing so. If your change is a bug-fix, make sure your commit log
236 indicates the end-user visible symptom, the underlying reason as
237 to why it happens, and then if necessary, explain why the fix proposed
238 is the best way to get things done. Don't mangle whitespace, and as
239 is common, don't mis-indent function arguments that span multiple lines.
240 If it is your first patch, mail it to yourself so you can test apply
241 it to an unpatched tree to confirm infrastructure didn't mangle it.
242
243 Finally, go back and read Documentation/process/submitting-patches.rst to be
244 sure you are not repeating some common mistake documented there.