Subject: RE: [PATCH v1 iproute2-next 1/4] rdma: add helper rd_sendrecv_msg()

From: "Steve Wise" <[email-masked]>
Date: Wed, 27 Feb 2019 14:23:45 -0600

> -----Original Message-----
> From: Steve Wise <[email-masked]>
> Sent: Tuesday, February 26, 2019 11:14 AM
> To: Leon Romanovsky <[email-masked]>
> Cc: [email-masked]; [email-masked];
> [email-masked]; [email-masked]
> Subject: Re: [PATCH v1 iproute2-next 1/4] rdma: add helper
> rd_sendrecv_msg()
> 
> 
> On 2/23/2019 3:26 AM, Leon Romanovsky wrote:
> > On Thu, Feb 21, 2019 at 08:19:03AM -0800, Steve Wise wrote:
> >> This function sends the constructed netlink message and then
> >> receives the response, displaying any error text.
> >>
> >> Change 'rdma dev set' to use it.
> >>
> >> Signed-off-by: Steve Wise <[email-masked]>
> >> ---
> >>  rdma/dev.c   |  2 +-
> >>  rdma/rdma.h  |  1 +
> >>  rdma/utils.c | 21 +++++++++++++++++++++
> >>  3 files changed, 23 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/rdma/dev.c b/rdma/dev.c
> >> index 60ff4b31e320..d2949c378f08 100644
> >> --- a/rdma/dev.c
> >> +++ b/rdma/dev.c
> >> @@ -273,7 +273,7 @@ static int dev_set_name(struct rd *rd)
> >>  	mnl_attr_put_u32(rd->nlh, RDMA_NLDEV_ATTR_DEV_INDEX, rd-
> >dev_idx);
> >>  	mnl_attr_put_strz(rd->nlh, RDMA_NLDEV_ATTR_DEV_NAME,
> rd_argv(rd));
> >>
> >> -	return rd_send_msg(rd);
> >> +	return rd_sendrecv_msg(rd, seq);
> >>  }
> >>
> >>  static int dev_one_set(struct rd *rd)
> >> diff --git a/rdma/rdma.h b/rdma/rdma.h
> >> index 547bb5749a39..20be2f12c4f8 100644
> >> --- a/rdma/rdma.h
> >> +++ b/rdma/rdma.h
> >> @@ -115,6 +115,7 @@ bool rd_check_is_key_exist(struct rd *rd, const
> char *key);
> >>   */
> >>  int rd_send_msg(struct rd *rd);
> >>  int rd_recv_msg(struct rd *rd, mnl_cb_t callback, void *data, uint32_t
> seq);
> >> +int rd_sendrecv_msg(struct rd *rd, unsigned int seq);
> >>  void rd_prepare_msg(struct rd *rd, uint32_t cmd, uint32_t *seq,
uint16_t
> flags);
> >>  int rd_dev_init_cb(const struct nlmsghdr *nlh, void *data);
> >>  int rd_attr_cb(const struct nlattr *attr, void *data);
> >> diff --git a/rdma/utils.c b/rdma/utils.c
> >> index 069d44fece10..a6f2826c9605 100644
> >> --- a/rdma/utils.c
> >> +++ b/rdma/utils.c
> >> @@ -664,6 +664,27 @@ int rd_recv_msg(struct rd *rd, mnl_cb_t callback,
> void *data, unsigned int seq)
> >>  	return ret;
> >>  }
> >>
> >> +static int null_cb(const struct nlmsghdr *nlh, void *data)
> >> +{
> >> +	return MNL_CB_OK;
> >> +}
> >> +
> >> +int rd_sendrecv_msg(struct rd *rd, unsigned int seq)
> >> +{
> >> +	int ret;
> >> +
> >> +	ret = rd_send_msg(rd);
> >> +	if (ret) {
> >> +		perror(NULL);
> > This is more or less already done in rd_send_msg() and that function
> > prints something in case of execution error. So the missing piece
> > is to update rd_recv_msg(), so all places will "magically" print errors
> > and not only dev_set_name().
> 
> Yea ok.
> 

dev_set_name() doesn't call rd_recv_msg().  So you're suggesting I fix up
rd_recv_msg() to display errors and make dev_set_name() call rd_recv_msg()
with the null_cb function?  You sure that's the way to go?