Re: [PATCH for-next v3] RDMA/rxe: Fix ib_device reference counting (again)

[Bob Pearson <rpearsonhpe@gmail.com>]

On 3/5/21 12:20 PM, Jason Gunthorpe wrote:
> On Thu, Mar 04, 2021 at 01:20:49PM -0600, Bob Pearson wrote:
>> From: Bob Pearson <rpearsonhpe@gmail.com>
>>
>> Three errors occurred in the fix referenced below.
>>
>> 1) rxe_rcv_mcast_pkt() dropped a reference to ib_device when
>> no error occurred causing an underflow on the reference counter.
>> This code is cleaned up to be clearer and easier to read.
>>
>> 2) Extending the reference taken by rxe_get_dev_from_net() in
>> rxe_udp_encap_recv() until each skb is freed was not matched by
>> a reference in the loopback path resulting in underflows.
>>
>> 3) In rxe_comp.c in rxe_completer() the function free_pkt() did
>> not clear skb which triggered a warning at done: and could possibly
>> at exit: . The WARN_ONCE() calls are not actually needed.
>> The call to free_pkt() is moved to the end to clearly show that
>> all skbs are freed.
>>
>> This patch fixes these errors.
>>
>> Fixes: 899aba891cab ("RDMA/rxe: Fix FIXME in rxe_udp_encap_recv()")
>> Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
>> Version 3:
>> V2 of this patch had spelling errors and style issues which are
>> fixed in this version.
>>
>> Version 2:
>> v1 of this patch incorrectly added a WARN_ON_ONCE in rxe_completer
>> where it could be triggered for normal traffic. This version
>> replaced that with a pr_warn located correctly.
>>
>> v1 of this patch placed a call to kfree_skb in an if statement
>> that could trigger style warnings. This version cleans that up.
>>
>>  drivers/infiniband/sw/rxe/rxe_comp.c | 55 +++++++++++---------------
>>  drivers/infiniband/sw/rxe/rxe_net.c  | 10 ++++-
>>  drivers/infiniband/sw/rxe/rxe_recv.c | 59 +++++++++++++++++-----------
>>  3 files changed, 67 insertions(+), 57 deletions(-)
> 
> I split this into three patches for-rc as is required by Linus.
> 
> It looks reasonable to me and the reorganizing make sense
> 
> Thanks,
> Jason
> 
Thanks. Sorry this took so long to resolve.

bob