On 6/2/15, 7:30 AM, Scott Feldman wrote:
On Tue, Jun 2, 2015 at 4:43 AM, Jamal Hadi Salim <j...@mojatatu.com> wrote:
On 06/02/15 03:10, Scott Feldman wrote:
Actually, we're now consistent with bridge man page which says master
is the default.
Want we want, I believe, is to adjust what the man page says (and the
bridge vlan command itself), by making the default master and self.
The kernel and driver are fine, it's the default in the bridge command
that needs adjusting. Once we do this, we'll be back to transparent
with software-only bridge.
Question to ask when looking at something of this nature:
Will it work with no suprises if you used today's unmodified app?
The default behavior shouldnt change and unfortunately it does here.
The default behavior does change, yes, but there shouldn't be any
surprises even if using today's unmodified app. The reason why is no
in-kernel driver is using ndo_bridge_setlink for VLAN setup. The
three drivers that have ndo_bridge_setlink use if to set hwmode to
VEBA|VEB. For VLAN setup, they use the (default master) bridge's
ndo_bridge_setlink->ndo_vlan_rx_add_vid. If the default changes from
master to master|self, the bridge's
ndo_bridge_setlink->ndo_vlan_rx_add_vid is still called for those
driver's using ndo_vlan_rx_add_vid, and if they implement
ndo_bridge_setlink, they'll get called a second time but will noop
because there will be no IFLA_BRIDGE_MODE (hwmode) attr to process.
So it comes down to two choices:
1) break ABI, which is inconsequential for in-kernel drivers and
preserve (iproute2) command transparency, or
2) embrace existing behavior which is consistent with man pages but
breaks command transparency for any driver implementing
ndo_bridge_setlink for VLAN setup, which currently is just rocker. I
can see the DSA going down this path also based on another concurrent
thread.
We're at option 2) right now.
It is not just iproute2 - since this is breaking ABI expectations.
Looking at some app i wrote a while back based on analyzing kernel
expectations at the time, I see the following logic:
user can set master or self on command line.
...
....
if (user DID NOT set master_on || user set self on)
then set self to on
iow, current behavior:
01: master is only set if user explicitly asked.
11: master|self when user explicitly sets both
10: self is on by default when the user doesnt specify anything
00: and the last option is to have none set which is not
possible since we have defaults.
cheers,
jamal
So this is very similar to iproute2 - if nothing is set
it defaults to self.
Ha, you're giving the behavior for "bridge fdb" command, where self is
the default.
Oh...i did not realize this was the case either. Thats unfortunate.
For "bridge link" and "bridge vlan", the default is master. The user
must explicitly specify "self" to act on the device side of the port.
It's unfortunate the iproute2 defaults aren't consistent between
commands. Maybe someone knows the history here and can explain.
scott, this brings back the discussion you and i had over the revert of
my patches.. (commit id's at the end of this email)...
which used to seamlessly offload to switchdev from bridge driver if the
port was a switch port (similar to stp state offload).
'self' used to exist before switchdev infra came in. My suggestion was
to use it where required...but not build the switchdev api on the
presence of 'self'. switchdev layer should be consistent across...all
fib/fdb/neigh layers.
I was at some point going to try to propose restore of my patches (with
proper error handling etc), and looking at where this conversation is
going.....it appears that it is going to be difficult.
commit 8508025c598bdee33d9afa153e9c00c7771e7d63
Author: Scott Feldman <sfel...@gmail.com>
Date: Sun May 10 09:48:03 2015 -0700
bridge: revert br_dellink change back to original
This is revert of:
commit 68e331c785b8 ("bridge: offload bridge port attributes to
switch asic
if feature flag set")
Restore br_dellink back to original and don't call into SELF port
driver.
rtnetlink.c:bridge_dellink() already does a call into port driver
for SELF.
bridge vlan add/del cmd defaults to MASTER. From man page for
bridge vlan
add/del cmd:
self the vlan is configured on the specified physical device.
Required if the device is the bridge device.
master the vlan is configured on the software bridge (default).
Signed-off-by: Scott Feldman <sfel...@gmail.com>
Acked-by: Jiri Pirko <j...@resnulli.us>
Signed-off-by: David S. Miller <da...@davemloft.net>
commit 41c498b9359e360f08723b7605ec0c40926ec415
Author: Scott Feldman <sfel...@gmail.com>
Date: Sun May 10 09:47:59 2015 -0700
bridge: restore br_setlink back to original
This is revert of:
commit 68e331c785b8 ("bridge: offload bridge port attributes to
switch asic
if feature flag set")
Restore br_setlink back to original and don't call into SELF port
driver.
rtnetlink.c:bridge_setlink() already does a call into port driver
for SELF.
bridge set link cmd defaults to MASTER. From man page for bridge
link set
cmd:
self link setting is configured on specified physical device
master link setting is configured on the software bridge
(default)
The link setting has two values: the device-side value and the software
bridge-side value. These are independent and settable using the bridge
link set cmd by specifying some combination of [master] | [self].
Furthermore, the device-side and bridge-side settings have their own
initial value, viewable from bridge -d link show cmd.
Restoring br_setlink back to original makes rocker (the only
in-kernel user
of SELF link settings) work as first implement: two-sided values.
It's true that when both MASTER and SELF are specified from the
command,
two netlink notifications are generated, one for each side of the
settings.
The user-space app can distiquish between the two notifications by
observing the MASTER or SELF flag.
Signed-off-by: Scott Feldman <sfel...@gmail.com>
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