[SRU,F:linux-bluefield,2/2] netfilter: flowtable: Make nf_flow_table_offload_add/del_cb inline

From: Alaa Hleihel <alaa@mellanox.com>

BugLink: https://bugs.launchpad.net/bugs/1927246

Currently, nf_flow_table_offload_add/del_cb are exported by nf_flow_table
module, therefore modules using them will have hard-dependency
on nf_flow_table and will require loading it all the time.

This can lead to an unnecessary overhead on systems that do not
use this API.

To relax the hard-dependency between the modules, we unexport these
functions and make them static inline.

Fixes: 978703f42549 ("netfilter: flowtable: Add API for registering to flow table events")
Signed-off-by: Alaa Hleihel <alaa@mellanox.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(backported from commit 505ee3a1cab96785fbc2c7cdb41ab677ec270c3c)

Conflicts:
	net/netfilter/nf_flow_table_core.c
---
 include/net/netfilter/nf_flow_table.h | 49 ++++++++++++++++++++++++++++++++---
 net/netfilter/nf_flow_table_core.c    | 44 -------------------------------
 2 files changed, 45 insertions(+), 48 deletions(-)

On 11/05/2021 13:50, Daniel Jurgens wrote:
> From: Alaa Hleihel <alaa@mellanox.com>
> 
> BugLink: https://bugs.launchpad.net/bugs/1927246
> 
> Currently, nf_flow_table_offload_add/del_cb are exported by nf_flow_table
> module, therefore modules using them will have hard-dependency
> on nf_flow_table and will require loading it all the time.
> 
> This can lead to an unnecessary overhead on systems that do not
> use this API.
> 
> To relax the hard-dependency between the modules, we unexport these
> functions and make them static inline.
> 
> Fixes: 978703f42549 ("netfilter: flowtable: Add API for registering to flow table events")
> Signed-off-by: Alaa Hleihel <alaa@mellanox.com>
> Reviewed-by: Roi Dayan <roid@mellanox.com>
> Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
> Signed-off-by: David S. Miller <davem@davemloft.net>
> (backported from commit 505ee3a1cab96785fbc2c7cdb41ab677ec270c3c)

Your SoB here.

> 
> Conflicts:
> 	net/netfilter/nf_flow_table_core.c

This is not needed.

> ---
>  include/net/netfilter/nf_flow_table.h | 49 ++++++++++++++++++++++++++++++++---
>  net/netfilter/nf_flow_table_core.c    | 44 -------------------------------
>  2 files changed, 45 insertions(+), 48 deletions(-)
> 
> diff --git a/include/net/netfilter/nf_flow_table.h b/include/net/netfilter/nf_flow_table.h
> index 3a46b3c..09c5a7f 100644
> --- a/include/net/netfilter/nf_flow_table.h
> +++ b/include/net/netfilter/nf_flow_table.h
> @@ -166,10 +166,51 @@ struct nf_flow_route {
>  struct flow_offload *flow_offload_alloc(struct nf_conn *ct);
>  void flow_offload_free(struct flow_offload *flow);
>  
> -int nf_flow_table_offload_add_cb(struct nf_flowtable *flow_table,
> -				 flow_setup_cb_t *cb, void *cb_priv);
> -void nf_flow_table_offload_del_cb(struct nf_flowtable *flow_table,
> -				  flow_setup_cb_t *cb, void *cb_priv);
> +static inline int
> +nf_flow_table_offload_add_cb(struct nf_flowtable *flow_table,
> +			     flow_setup_cb_t *cb, void *cb_priv)
> +{
> +	struct flow_block *block = &flow_table->flow_block;
> +	struct flow_block_cb *block_cb;
> +	int err = 0;
> +
> +	mutex_lock(&flow_table->flow_block_lock);
> +	block_cb = flow_block_cb_lookup(block, cb, cb_priv);
> +	if (block_cb) {
> +		err = -EEXIST;
> +		goto unlock;
> +	}
> +
> +	block_cb = flow_block_cb_alloc(cb, cb_priv, cb_priv, NULL);
> +	if (IS_ERR(block_cb)) {
> +		err = PTR_ERR(block_cb);
> +		goto unlock;
> +	}
> +
> +	list_add_tail(&block_cb->list, &block->cb_list);
> +
> +unlock:
> +	mutex_unlock(&flow_table->flow_block_lock);
> +	return err;
> +}
> +
> +static inline void
> +nf_flow_table_offload_del_cb(struct nf_flowtable *flow_table,
> +			     flow_setup_cb_t *cb, void *cb_priv)
> +{
> +	struct flow_block *block = &flow_table->flow_block;
> +	struct flow_block_cb *block_cb;
> +
> +	mutex_lock(&flow_table->flow_block_lock);
> +	block_cb = flow_block_cb_lookup(block, cb, cb_priv);
> +	if (block_cb) {
> +		list_del(&block_cb->list);
> +		flow_block_cb_free(block_cb);

This does not match the other block. When cherry-pick fails on such
changes (or if there is any FUZZ), you need to actually perform entire
change manually - move the code around.


Best regards,
Krzysztof