]> git.proxmox.com Git - mirror_ubuntu-eoan-kernel.git/commit
RDMA/be2net: Remove open and close entry points
authorDevesh Sharma <devesh.sharma@avagotech.com>
Thu, 24 Dec 2015 18:14:08 +0000 (13:14 -0500)
committerDoug Ledford <dledford@redhat.com>
Mon, 28 Dec 2015 16:45:55 +0000 (11:45 -0500)
commitf41647ef06536199d3366530da050b411546979d
tree36fbab2f896a5c5253f6a8c904b1d4e442921971
parent10a214dc996236e6547b84fb5ca007316b30c2e6
RDMA/be2net: Remove open and close entry points

Recently Dough Ledford reported a deadlock happening
between ocrdma-load sequence and NetworkManager service
issueing "open" on be2net interface.

The deadlock happens when any be2net hook (e.g. open/close) is called
in parallel to insmod ocrdma.ko.

A. be2net is sending administrative open/close event to ocrdma holding
   device_list_mutex. It does this from ndo_open/ndo_stop hooks of be2net.
   So sequence of locks is rtnl_lock---> device_list lock

B.  When new ocrdma roce device gets registered, infiniband stack now
    takes rtnl_lock in ib_register_device() in GID initialization routines.
    So sequence of locks in this path is device_list lock ---> rtnl_lock.

This improper locking sequence causes deadlock.

In order to resolve the above deadlock condition, ocrdma intorduced a
patch to stop listening to administrative open/close events generated from
be2net driver. It now depends on link-state-change async-event generated from
CNA. This change leaves behind dead code which used to generate administrative
open/close events. This patch cleans-up all that dead code from be2net.

Reported-by: Doug Ledford <dledford@redhat.com>
CC: Sathya Perla <sathya.perla@avagotech.com>
Signed-off-by: Padmanabh Ratnakar <padmanabh.ratnakar@avagotech.com>
Signed-off-by: Selvin Xavier <selvin.xavier@avagotech.com>
Signed-off-by: Devesh Sharma <devesh.sharma@avagotech.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
drivers/net/ethernet/emulex/benet/be.h
drivers/net/ethernet/emulex/benet/be_main.c
drivers/net/ethernet/emulex/benet/be_roce.c
drivers/net/ethernet/emulex/benet/be_roce.h