> On Apr 23, 2021, at 5:06 PM, Trond Myklebust <trondmy@xxxxxxxxxxxxxxx> wrote:
>
> On Mon, 2021-04-19 at 14:02 -0400, Chuck Lever wrote:
>> Currently rpcrdma_reps_destroy() assumes that, at transport
>> tear-down, the content of the rb_free_reps list is the same as the
>> content of the rb_all_reps list. Although that is usually true,
>> using the rb_all_reps list should be more reliable because of
>> the way it's managed. And, rpcrdma_reps_unmap() uses rb_all_reps;
>> these two functions should both traverse the "all" list.
>>
>> Ensure that all rpcrdma_reps are always destroyed whether they are
>> on the rep free list or not.
>>
>> Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
>> ---
>> net/sunrpc/xprtrdma/verbs.c | 31 ++++++++++++++++++++++++-------
>> 1 file changed, 24 insertions(+), 7 deletions(-)
>>
>> diff --git a/net/sunrpc/xprtrdma/verbs.c
>> b/net/sunrpc/xprtrdma/verbs.c
>> index 1b599a623eea..482fdc9e25c2 100644
>> --- a/net/sunrpc/xprtrdma/verbs.c
>> +++ b/net/sunrpc/xprtrdma/verbs.c
>> @@ -1007,16 +1007,23 @@ struct rpcrdma_rep *rpcrdma_rep_create(struct
>> rpcrdma_xprt *r_xprt,
>> return NULL;
>> }
>>
>> -/* No locking needed here. This function is invoked only by the
>> - * Receive completion handler, or during transport shutdown.
>> - */
>> -static void rpcrdma_rep_destroy(struct rpcrdma_rep *rep)
>> +static void rpcrdma_rep_destroy_locked(struct rpcrdma_rep *rep)
>
> The name here is extremely confusing. As far as I can tell, this isn't
> called with any lock?
Fair enough.
I renamed it rpcrdma_rep_free() and it doesn't seem to have
any consequences for downstream commits in this series.
You could do a global edit, I can resend you this patch with
the change, or I can post a v4 of this series. Let me know
your preference.
>> {
>> - list_del(&rep->rr_all);
>> rpcrdma_regbuf_free(rep->rr_rdmabuf);
>> kfree(rep);
>> }
>>
>> +static void rpcrdma_rep_destroy(struct rpcrdma_rep *rep)
>> +{
>> + struct rpcrdma_buffer *buf = &rep->rr_rxprt->rx_buf;
>> +
>> + spin_lock(&buf->rb_lock);
>> + list_del(&rep->rr_all);
>> + spin_unlock(&buf->rb_lock);
>> +
>> + rpcrdma_rep_destroy_locked(rep);
>> +}
>> +
>> static struct rpcrdma_rep *rpcrdma_rep_get_locked(struct
>> rpcrdma_buffer *buf)
>> {
>> struct llist_node *node;
>> @@ -1049,8 +1056,18 @@ static void rpcrdma_reps_destroy(struct
>> rpcrdma_buffer *buf)
>> {
>> struct rpcrdma_rep *rep;
>>
>> - while ((rep = rpcrdma_rep_get_locked(buf)) != NULL)
>> - rpcrdma_rep_destroy(rep);
>> + spin_lock(&buf->rb_lock);
>> + while ((rep = list_first_entry_or_null(&buf->rb_all_reps,
>> + struct rpcrdma_rep,
>> + rr_all)) != NULL) {
>> + list_del(&rep->rr_all);
>> + spin_unlock(&buf->rb_lock);
>> +
>> + rpcrdma_rep_destroy_locked(rep);
>> +
>> + spin_lock(&buf->rb_lock);
>> + }
>> + spin_unlock(&buf->rb_lock);
>> }
>>
>> /**
>>
>>
>
> --
> Trond Myklebust
> Linux NFS client maintainer, Hammerspace
> trond.myklebust@xxxxxxxxxxxxxxx
--
Chuck Lever
