Linux kernel source tree
Go to file
Jiri Wiesner 0410d07190 bonding: fix active-backup failover for current ARP slave
When the ARP monitor is used for link detection, ARP replies are
validated for all slaves (arp_validate=3) and fail_over_mac is set to
active, two slaves of an active-backup bond may get stuck in a state
where both of them are active and pass packets that they receive to
the bond. This state makes IPv6 duplicate address detection fail. The
state is reached thus:
1. The current active slave goes down because the ARP target
   is not reachable.
2. The current ARP slave is chosen and made active.
3. A new slave is enslaved. This new slave becomes the current active
   slave and can reach the ARP target.
As a result, the current ARP slave stays active after the enslave
action has finished and the log is littered with "PROBE BAD" messages:
> bond0: PROBE: c_arp ens10 && cas ens11 BAD
The workaround is to remove the slave with "going back" status from
the bond and re-enslave it. This issue was encountered when DPDK PMD
interfaces were being enslaved to an active-backup bond.

I would be possible to fix the issue in bond_enslave() or
bond_change_active_slave() but the ARP monitor was fixed instead to
keep most of the actions changing the current ARP slave in the ARP
monitor code. The current ARP slave is set as inactive and backup
during the commit phase. A new state, BOND_LINK_FAIL, has been
introduced for slaves in the context of the ARP monitor. This allows
administrators to see how slaves are rotated for sending ARP requests
and attempts are made to find a new active slave.

Fixes: b2220cad58 ("bonding: refactor ARP active-backup monitor")
Signed-off-by: Jiri Wiesner <jwiesner@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-18 15:57:47 -07:00
arch parisc: fix PMD pages allocation by restoring pmd_alloc_one() 2020-08-16 10:53:13 -07:00
block block-5.9-2020-08-14 2020-08-15 20:36:42 -07:00
certs .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2020-08-14 13:09:15 -07:00
Documentation Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-08-17 17:09:50 -07:00
drivers bonding: fix active-backup failover for current ARP slave 2020-08-18 15:57:47 -07:00
fs io_uring-5.9-2020-08-15 2020-08-16 10:55:12 -07:00
include Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-08-17 17:09:50 -07:00
init OpenRISC updates for 5.9 2020-08-14 14:04:53 -07:00
ipc ipc/shm.c: remove the superfluous break 2020-08-12 10:58:02 -07:00
kernel Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-08-17 17:09:50 -07:00
lib iomap: constify ioreadX() iomem argument (as in generic implementation) 2020-08-14 19:56:57 -07:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm Merge branch 'akpm' (patches from Andrew) 2020-08-15 08:02:03 -07:00
net net: handle the return value of pskb_carve_frag_list() correctly 2020-08-18 15:56:56 -07:00
samples Kbuild updates for v5.9 2020-08-09 14:10:26 -07:00
scripts Kconfig updates for v5.9 2020-08-14 11:04:45 -07:00
security Merge branch 'akpm' (patches from Andrew) 2020-08-12 11:24:12 -07:00
sound sound fixes for 5.9-rc1 2020-08-14 15:58:57 -07:00
tools Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-08-17 17:09:50 -07:00
usr Merge branch 'work.fdpic' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-08-07 13:29:39 -07:00
virt Merge branch 'akpm' (patches from Andrew) 2020-08-12 11:24:12 -07:00
.clang-format block: add bio_for_each_bvec_all() 2020-05-25 11:25:24 +02:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: Add ZSTD-compressed files 2020-07-31 11:50:49 +02:00
.mailmap mailmap: Add WeiXiong Liao 2020-08-17 14:32:44 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS CREDITS: Replace HTTP links with HTTPS ones 2020-07-23 14:53:58 -06:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS perf tools changes for v5.9: 2nd batch 2020-08-15 11:17:15 -07:00
Makefile Linux 5.9-rc1 2020-08-16 13:04:57 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.